Describe and evaluate psychological research Essay

There are many different factors into why some relationships fail and others succeed. In this particular essay, I will look into why some relationships do breakdown.  The first model into the dissolution of relationships was devised by Karney and Bradbury (1955). They said that there were three major factors that determined marital stability. The first of these were enduring vulnerabilities, which includes an unhappy childhood and high neuroticism. The second is stressful events such as illness or poverty. Lastly, adaptive processes also have an effect. This refers to constructive and destructive coping strategies to resolve issues. All three factors can be linked together; for example, enduring vulnerabilities can cause stressful events. This model is good because past research has shown that many factors have been associated with the breakdown of relationships, and most of these factors can be related to the three variables mentioned in this model. This shows that it can explain why some relationships do break down. Another strength is that it shows how these three variables can link together to reduce marital quality. However, it can be criticised as it places too much emphasis on marital quality and satisfaction leading to a break-up. Levinger argued that there are other factors that also affect whether a couple break up or not. An example of this is divorce – people may not want to go through the hassle. Duck (1988) proposed a four-phase model, which explains what happens during the termination of close or intimate relationships. The first stage is the intra-psychic phase, where one of the partners becomes very unhappy with the relationship. This then leads to the dyadic phase, where the other person becomes involved. If the problem is not resolved, then it leads to the social phase where family and friends become involved. If the problem is not resolved here then it goes to the final stage. This is the grave-dressing phase, where the ex-partners begin the organisation of their post-relationship lives. A strength of this model is that it addresses cognitive aspects, not just behavioural aspects of relationships. It has important implications for the repair of relationships. However, it can be criticised because, although it mentions the stages of a breakdown, it doesn’t provide reasons for why this happens. It also doesn’t take into account individual differences for example; it assumes that everyone goes through the same stages in a relationship break-up. This might not necessarily be true, for example not every relationship breakup may involve friends or family, or couples may go through the stages in a different order. Lastly, it is culturally biased, and so the results cannot be generalised to other countries. For example, Japan see break-ups as wrong and so probably wouldn’t go through those phases. Another theory into the dissolution of break ups is Lee’s (1984) Model of Relationship Break Up. He conducted extensive interviews of 112 break-ups of premarital romantic relationships. He argued that there were five stages to a relationship break-up. The first of these is dissatisfaction, which is when the couple realise there are problems within the relationship. Next is exposure where the dissatisfaction is brought into the open, and then is negotiation where discussions of the issues are raised. Resolution then happens when the partners try to find ways to solve the problems and if this doesn’t work, then termination happens, which is the final stage. However, there are weaknesses to this theory. For example, it assumes that everyone goes through those stages and so doesn’t take into account individual differences. In fact, couples may miss out certain stages such as resolution. In terms of both Duck and Lee’s models, a 6 or 7 stage model incorporating phases from both of the models would provide a better and more accurate account of the break up of a relationship. The Social Exchange theory, proposed by Thibaut and Kelley (1959) can also explain the dissolution of relationships. This theory is based on the cost and rewards, or the give and take in a relationship. Costs in a relationship could be seen as energy, time and money spent, whereas rewards could be affection, company and security. The Social Exchange Theory argues that the relationship will end if the costs are greater than the rewards. It states that we compare the relationship we are in to past relationships -if the costs and rewards are better or worse than before, it can help to determine whether we will stay in that relationship. This theory is strengthened by the Equity theory, which states that people are happiest in relationships if the give and take is about equal. However, there are some criticisms – firstly, it doesn’t take into account people’s feelings. Secondly, although it provides a reason for why relationships breakdown, it doesn’t explain how.

How the Digital World May Change Essay

The rapidly changing societies with constantly improving technology and occurrence of social digital technologies dramatically changed the way people communicate and interact with each other making them either â€Å"digital natives†, â€Å"digital residents†, â€Å"digital immigrants† or â€Å"digital visitors† based on their generation or familiarization with technology. More and more people today perceive the world as the complicated and mature network of computerized and online applications that help to communicate, search for, exchange and share information, make business with international partners, play games on distance, and many other purposes. Though, the question is whether digital natives and digital residents are the same in their perception of the world, behavior and life habits in the future? Behavior of Digital Residents Since personally I was born before 1994, I am related to the category of digital residents, who were born before the occurrence of social digital technologies. Such people like me learnt the computer and Internet-related skills either in schools or universities and have an opportunity to compare life and perception of the world before and after the digital world. Despite I am not a digital native, my behavior as a digital resident is already influenced by numerous technologies I am using daily like cell phone, computer, DVD player, iPod, etc. With occurrence of cell phones, for example, people became more flexible and mobile in their behavior, actions, plans and ability to communicate with their family members, friends and colleagues. Moreover, many people combine conversations by cell phone with other activities like cleaning the house, working on the computer, shopping or driving a car (Palfrey and Gasser, 2008). Recently more and more people, including me, prefer to make their personal or business calls while driving to the office, shop or gym. It might be a good way to use time efficiently, though at the same time might cause problems and distract a person from driving and being careful on the road. In one of his first video chapters Robert Schrag (2010) addressed exactly this issue when young people got used to talk by phone and type text messages while driving. Though, the main difference in such behavior between digital natives and digital residents is that the last ones are more careful, reasonable and less dependent on the technologies than digital natives are (Palfrey and Gasser, 2008). It might sound crazy, but computers, cell phones and other technology-related products became a mandatory and integral daily part of their lives. While as a digital resident I am less dependent, or better to say, obsessed with technology, the changing world of education and business requires being constantly aware and familiar with the latest technologies, either to learn the updated and useful information for my personal and professional development or to keep pace with younger people whose knowledge of languages, computers and technology-related applications make them more competitive at the labor market. Conclusion  As for the future behavior as a digital resident, it is rather hard to predict since more and more innovations enter our lives. For example, nowadays a debate exists concerning two main issues: human cloning and brain chips. Personally, I do not support either of these ideas since with their occurrence and legacy people will be controlled by those who created such innovations while the human being is independent self-thinker who is responsible for his/her own actions, has personal wishes and dreams and is unpredictable in his/her behavior. While digital world gives me more and more opportunity to learn the world and communicate with other people, at the same time it controls me more and more shaping my behavior in the way innovators and digital world creators want. I personally think that technology should be wisely and within certain limits without suppressing and eliminating the natural things and personal communication between people.

Russian Economy Before And After Vladimir Putin Essay

Russian Economy Before And After Vladimir Putin - Essay Example The country has implemented multifaceted foreign policy as is also recognized as the successor state of the former USSR. Till 2009, the country maintained diplomatic relations with around 190 countries as well as with around 140 embassies. Since the fall of the Soviet Union, Russia has emerged as one of the powerhouse in the scenario of global trade. The country adopted a democratic form of government and the regime of free market. The country got its inclusion in BRIC constitution along with India, Brazil and China. The BRIC group leads the developing world in terms of growth and economic transformation. To talk about the market access, most of the goods can be freely imported to the country. The country focused intensely on joining the World Trade Organization after the presidential election of 1999. The accession of the country to the WTO is now complete. Significant amount of progress was made in the last year which paved the way for the accession. The country will benefit from t he accession in the long run on several fronts, one of the most important being the discriminatory measures held by the 30 countries against the exports of steel of Russia. It is also anticipated that the accession to the WTO drives in more foreign investments. The country follows the system of harmonized Customs. The Russian history faced difficult times in the first 20 years of the last century. The civil war ruined the country, the people starved because of the economic embargo of the governments. The government was not able to gather pace on the imports as well as exports which was the need of the time. To deal with the situation, the Russian government decided to send a trade mission to UK. The Economy of Russia The economy of the country is ranked ninth in the world in terms of nominal value while the economy is ranked sixth in terms of purchasing power parity. The economy has transformed to a market based economy from a centrally planned one after the collapse of the Soviet U nion. The reforms of the 1990 privatized many sectors while the sectors like energy and defence being the exceptions. Macroeconomic stabilization as well as restructuring of the economy can be regarded as the indicators for transition from centrally planned to an economy that is based on the market. Macroeconomic stabilization entails implementation of monetary and fiscal policies. The aim of implementation is promotion of economic growth that will pave the path for stable prices and exchange rates. Restructuring of the economy require establishment of entities like commercial or institutional. These entities will allow the operation of the economy in an efficient fashion. One of the footsteps to achieve this goal is to open up the domestic market to foreign trade. The economy thus gets linked with the rest of the world. The bid of the country to join WTO faced a hurdle on the issues of low rate of domestic energy consumption and the closeness of the market for the foreign competito rs. The member countries of WTO expressed the view that the country should charge equal prices for oil and gas even domestically. The accession process was boosted as Russia worked out the disagreements on prices of energy as well as agricultural subsidies with European Union. In the year 2003, WTO estimated that the country is positioned 17th in the rank of largest exporters of the world. The minister of trade announced that the country has the potential to gain thousands of dollars once it has access to the regime and the world markets. As the pressure to resort to

Social Research Methods Case Study Example | Topics and Well Written Essays - 750 words

Social Research Methods - Case Study Example There are various reliability measures which include observer reliability, test reliability, parallel reliability, and consistent reliability. This involves the efforts to establish where their observations are consistent with the others, example a study involving the interview of two individuals then there is a need to compare the two observations and establish whether the results from both observations are consistent and therefore reliable. In test reliability we try to establish the correlation between studies undertaken in two time periods, it is evident from research that given the same sample and undertake the study after a short time period than the higher the correlation but if we took the same sample and the have a longer time period then the lower the correlation. This involves testing reliability using any set of questions that tend to yield same results, in a study questions can be split into two where the second part tends to establish the same results as the first part, this way the similarities will help establish whether the results are consistent and reliable. This involves establishing a single measure of consistency on a group of participants at the same time and try to establish whether the results are consistent, this helps in determining whether a study undertaken on the group will be consistent. All the above methods are used in establishing whether the results of a study are reliable or not, however, the methods have their strength and weakness but they are important in determining reliability. The validity can be defined as the best approximation of truth of inference, however, the validity of a study does not depend on the use of good study design or even use of good samples in the study. Validity measure is divided into four including conclusion validity, internal validity, construction validity and finally external validity. Conclusion validity involves comparing the results of the study and the conclusion, for example, if in a study we want to establish the relationship that exists between variable A and B and that A causes B then if we conclude that A causes B then the results are valid.

The burden of proof Essay Example | Topics and Well Written Essays - 500 words

The burden of proof - Essay Example The Union’s past practice argument cannot hold because the assessment test has already been given to previous applicants in the Technical Department.   The Union claimed that the company awarded the job to senior bidders in the past.   However, the Union did not take into consideration that seniority was not the only requirement, passing the assessment test was a minimum qualification for the position being bided for.3. Does it matter which type of assessment is used by the Company?  Yes, the type of assessment used by the Company matters because it will determine if a certain applicant is qualified to do the job or not.   The type of assessment should be able to measure the capabilities of the applicant which are necessary in accomplishing a certain job.4. If the Union alleged that the Work Keys Assessment was not valid, which party wouldhave to prove the validity?  The validity of the Work Keys Assessment should be proven by the company through the Subject Matter E xperts (SMEs) who designed it and approved its use.   The SMEs have been with the company for an average of more than 17 years.   As stated by the company, â€Å"Who better to determine the tasks and skills required for an entry-level position than those who have performed it?"   The SMEs are in a position to state that those who pass the test have the necessary skill levels for entry and effective performance in the extra hand position.5. You are the arbitrator. What is your decision? Why? If I were the arbitrator of the case, my decision is that Ms. Boone.

Information Security Essay Example | Topics and Well Written Essays - 1000 words

Information Security - Essay Example Thus, saving it is as significant as caring their currency and other physical resource as well as necessitates just as a great deal of protection and arrangement (Motorolla, 2010). As information has turned out to be the most valuable resource for any business and extremely important for business in such scenario where an organization needs to take a great care of such resources. So to serve this purpose there is need for establishing and maintaining better security policy inside the corporation that offers enhanced awareness as well as insight into the corporate processes and departments. This paper presents some of the prime aspects of security and its awareness. The aim of this paper is to analyze the ideas which have been presented by Bruce Schneier. According to (Schneier, 2008), the security is a sense, which is not based on the likelihood as well as mathematical computations however on our mental responses to both dangers and countermeasures. In this scenario, we might experie nce horribly frightened of terror campaign, or else we might believe similar to it is not something value anxious about. Thus, the understanding and actuality of security is surely connected to one another: however they are surely not the similar as each other. We would certainly be more affluent if we had two diverse terms for them. Moreover, Schneier (2008) has tried to discover the sense of security (Schneier, 2008). The techniques that will most successfully reduce the capability of hackers as well as intruders to damage and negotiate information security are requiring wide-ranging user teaching and learning. Additionally, endorsing strategies as well as measures only would not be sufficient. Moreover, still by means of lapse the strategies as well as procedures cannot be efficient (iWAR, 2010). In this regard, a business security management team cannot simply offer the type of general corporate consciousness essential to keep away the large multiplicity of events a business mig ht experience. That type of responsiveness necessitates the dynamic contribution of every staff member in the corporation. Additionally, incidents happened through workers faults produces extreme harm to the company each year than outside attacks. In this scenario, getting the support as well as contribution of an organization’s workers necessitates an energetic knowledge program; one that is up-held through the entire layers of management (Olzak, 2006). Producing an information security and privacy knowledge as well as teaching program are not easy jobs to do. They are frequently annoying jobs. Additionally, a lot of times, unluckily, it is regularly a difficult job. Though, offering their employees with the security and privacy information they require making sure they recognize and pursue the necessities, are a significant part of an organization's dealing accomplishment. If the employees of an organization are not familiar with or recognize how to uphold privacy of data a nd information, or how to protect it properly, they not simply danger having one of their most precious business resources (information) mismanagement, acquired by illegal persons, unsuitably utilized but as well threat being in disobedience of a large number of rules and policies that necessitate certain kinds of data and information security as well as privacy knowledge and teaching procedures. Moreover, they also risk spoiling another precious resource or asset, business status. Thus, information privacy and security teaching is significant for a lot of causes (Herold, 2010). Schneier (2008) outlined four main features of the information secu

A Claim for Religious Discrimination against Coach Al West Assignment - 2

A Claim for Religious Discrimination against Coach Al West - Assignment Example Title 11 of the Civil Rights Act recognizes sports arena, stadium, and other public places of exhibition or entertainment as public accommodation places (Loevy, 1997). For that reason, Ahman could bring a claim for religious discrimination against the NWSU coach under the Title 11 of the Civil Rights Acts. Â  Question 2 Answer: Mohammed Ahman could also bring a religious discrimination claim against NWSU coach under the First Amendment Free Exercise Clause. The First Amendment Free Exercise Clause recognizes the individual right to practice his/her religion, without any form of interference from the government or from anybody else (First Amendment: Chapter 9, n.d). Although by discriminating Ahman on religious grounds NWSU coach did not directly deny Ahman his right to practice his religion, the discrimination, however, indirectly interfered with Ahman’s right to religious freedom recognized by the First Amendment Free Exercise Clause. By asking the football team to recite the Lord’s player after each practice, the NWSU coach failed to recognize the Ahman’s religious freedom to exercise his religion of choice; this action, therefore, amounts to interference with Ahman’s right to freely exercise his religion. Secondly, the NWSU coach’s constant inquir y from Ahman on the relationship between Al-Qaeda and Islam shows that the NWSU coach had a negative attitude towards Islam as a religion. The negative attitude towards Islam could make Ahman uncomfortable in practicing his religion; this again amounts to interference with Ahman’s right to freely exercise his religion.

Prescription Pill Abuse Research Paper Example | Topics and Well Written Essays - 1250 words

Prescription Pill Abuse - Research Paper Example Many teenagers hold the view that prescription medication abuse is safer than illicit drug intake. However, the fact is that prescription drugs can have severe short term as well as long term impacts on health if they are used improperly. Hence, it could be stated that the use and abuse of prescription pills has adverse effect on teenagers’ physical, mental, and social life. Prescription pill abuse may include taking a relative’s or a friend’s prescribed medicines to treat pain, get high, or to experiment with. As per reports, Opioids like OxyContin and Vicodin, stimulants like Concerta and Adderall, and central nervous system depressants including Xanax and Valium are the most common abused prescription pills over the past few years. Over-the-counter drugs (drugs available without a prescription) abuse has also become a threatening issue nowadays. Among the teenagers aged between 12 and 17, it was reported that 7.7 percent of them abused prescription drugs during 2010 (â€Å"Prescription drug abuse†). According to a study conducted by the Partnership for a Drug-Free America, nearly one fifth of the teenagers have tried prescription painkillers ever in their life (cited in â€Å"Addictions: Generation Rx?..†). As The 2010 Monitoring the Future survey reports, prescription and over-the-counter pills were the most common drugs abused by 12th graders (NIDA). These surveys also point that prescription drug abuse may get intensified in future as no effective prevention mechanisms have been developed yet. In addition, surveys and other study reports indicate that prescription drug abusing youth is more likely to get addicted to substance abuse. Evidently, medication has side effects and therefore, a physician considers all potential benefits and risk factors of a drug before making prescriptions. In addition to the side effects factors, a physician takes into account a drug’s form and dose and its potential for addiction or withdrawal.

American Expansionism Essay Example | Topics and Well Written Essays - 750 words

American Expansionism - Essay Example In the period from 1890 to 1920, the US economy functioned in an optimal manner achieving impressive results. In 1900, the US had 38 percent of world’s wealth, which is 13 percent more than Britain. This economic might enabled leaders to pursue expansionism and importantly financed it as well. â€Å"Economic power set the foundations of American power, facilitating leaders to pursue ‘grand’ policies† (Efthymiou). The other related cause is that the US wanted to further develop its economy, which they wanted to achieve by capturing and tapping resources-rich territories. That is, after capturing and entering newer territories, the US looked for key resources or materials, which can be sold separately or can be used to manufacture finished goods. Those finished good were sold or exported to various countries thereby developing its economy. â€Å"†¦expansionism was driven by the idea that the American economy needs to grow continuously† (Johnston 1 89). The third cause which initiated expansionism was the strengthening of its naval wing. The US’s Navy Admiral of that period, Alfred Thayer Mahan only emphasized â€Å"the need for a powerful navy and the creation of â€Å"coaling stations† in strategic regions with significance in world trade† (Efthymiou). When this started actualizing, the US became confident in its expansion plans. The US expanded its role and influence through three ways namely imperialism or armed conflicts, international diplomacy, and through the construction of the Panama Canal. In 1898, the US declared a war on Spanish territories in the Caribbean and totally dismantled the waning Spanish Empire. So by evicting Spain, the US fortified its advantageous grip on the Caribbean, built a naval base in Cuba, and even annexed Puerto Rico (Efthymiou). It further extended its influence into the Pacific by capturing Philippines and Guam. The US also expanded its influence by actively

The opening balance Essay Example for Free

The opening balance Essay In this cash forecast I will analyse where the Steve’s business can improve on whether they are making a profit or not. Also I need to identify where they have regular inflow and outflows and irregular inflow and outflows. I will also comment on how the fresh business can maintain more regular numbers. January and February In January the sales is  £17,000 it increases by  £2,000 to  £19,000.the total income in January was  £32,000 it decreases by  £13,000 to  £19,000 because the loan was one off income. It an irregular cash inflow which only happened in January. These profit can be use to expand or give the staff bigger salaries for there hard work. A regular cash inflow is good for business you know how much money going in to business. This makes it easily to predict future sales. Fresh business had total of  £174,000 for there sales revenue. In January and February raw material has regular cash outflows going out of the business. For gas, electric and water bills fresh business has to pay the  £700 each month. This regular cash outflow is very good for the business. The business can identify how much money is going out business. This is the same with salaries which  £4,000, lease for premises was  £1,500 and advertising that was. However in January there was no lease payment this mean the total expenditure is 17,000 this increases in February to  £18,200. The monthly net cash flow in January is  £15,000 and in February is  £800. It has decrease by  £14,200. I think the business should decrease the salaries to  £3000 because the monthly cash flow tells you that they are making a loss. The closing balance is  £25,000 and in February is  £25,800. The closing balance has increases by  £800 this because their no loan taken out. March and April The opening balance for the start of March is  £25,800 and for April it was  Ã‚ £25,600. Is has decrease by  £200. This is because loan was cash inflow and the sales revenue has decreases by  £3000. The sale revenue is  £18,000 in March and in April it was  £15,000.this is because there were lower demands for product meaning less people brought them. Loan is irregular payment so no money from loan came into the business both months. In March and April raw material has regular cash outflows going out of the business  £10,000 each month. For gas, electric and water bills fresh business has to pay the  £700 each month. This regular cash outflow is very good for the business. The business can identify how much money is going out business. This is the same with salaries which  £4,000, lease for premises was  £1,500 and advertising was  £200. However in March there was lease payment this mean the total expenditure is  £18,200 this is the same with April  £18,200. The new cooking equipment, delivery van and fuel for van are an irregular cash outflow at nothing in both March and April and the bills are a regular cash outflow at  £700 for both months. The total expenditure for both months is  £18,200 because there are an equal amount of payments. By reducing salaries and increasing advertisement the business will earn more money, Steve will then not make a loss at the closing balance. The monthly net cash flow in both months is negative at - £200 and - £3,200. This will have a bad impact on the business. The closing balance is  £25,000 and  £22,400 for each of the months a decrease of  £3,200. This has had a bad impact the business on Steve’s business as he is making less money and will eventually lead to bankrupt if he carry on like this. May and June The opening balance for May is at  £22,400 and for June at  £14,500. Steve has made a decrease of  £7,900 this is because of the sales revenue as the demand kept on going up and down for the previous months. The sales revenue for May is at  £11,000 because of a high demand Steve’s however this decreases to  £8,000 in June because of a lower demand for Steve’s product even though  Steve has bought the same amount of raw materials. There is no loan and the total income for both months is at  £11,000 and  £8,000 a decrease of  £3,000. The expenditure stays the same however, the delivery van and the fuel for the van both being an irregular cash outflow starts to kick in at  £8,000 only in May and  £200 for both months. The total expenditure for May is at  £18,900 and this is because of the cost for the delivery van. Irregular expenditure is bad for the company because you don’t know when it going to happen or how much going to cost. It had effect the business badly because it had a monthly cash flow. However, Steve has made a dramatic improvement between this month and all the others as the total expenditure totals up to  £10,900 for June it was better than may total expenditure  £18,200 the reason why there is a decrease is the delivery van was an irregular outflow. The monthly net cash flow is at - £7,900 for May and - £2,900 for June this is a decrease of - £5,000 and this is decreasing hopefully meaning it will time we will see more positive monthly cash outflows. The closing balance for May is at  £14,500 and for June at  £11,600 a decrease of  £2,900. This is having a bad impact on the business because of the monthly net cash flow and total expenditure are both negative means Steve’s business is not making profit only loss. It could be costly in the long run. I think Steve should lower his salary to  £3000 since they are not having positive monthly net cash and total expenditure. July and August The opening balance for July starts off with  £11,600 however the opening balance for August is  £6,700 a decrease of  £4,900. This is because of the sales revenue for the previous month. The sales revenue for July is  £6,000 however; this increases to  £8,000 the next month an extra  £2,000 profit. Although they had the same amount of raw materials price they sold more. No loan has been taken out for any of the months. The reason why there increase in Steve sales revenue, is that the demands for Steve product have increase. The total expenditure for July and August is the same at  £10,900. This is having a good impact on the business as this will result in a regular cash flow which will then allow Steve to easily predict future cash flows and make plans to help advance his business. The monthly net cash flow for July is at a negative at - £4,900 however; this is getting better and the money should eventually go to a positive as in August the price lowers to - £2,900 and increase of  £2,000. This must be because of the sales in the months before and the sales revenue in these months. The closing balance is at  £6,700 for July a decrease from the previous months and this gets worse at it progresses to the next month and the closing balance goes to  £3,800. This reason for this decrease is the sales revenue prevised month. September and October The opening balance starts off with  £3,800. This is having a bad impact on the business as Steve will not be able to pay the bills or pay for stock and he will then eventually go bank-corrupt. In October there is a slight improvement as the opening balance is  £3,900. The sales revenue starts to recover as for September it is  £11,000 a huge improvement from the previous months. For October there is a higher increase  £18,000. This is having a good impact on the business. The raw materials increases from  £2,500 to  £12,500 from October to December to all of this change the prices of raw material increase significantly to  £12,500. The reason for why the prices of raw material have gone up is the demands for the product has gone up. Therefore Steve has to buy more raw materials for his customers. Regular cash outflow is good for the business because there always has to be money going out of your business. This makes it easier for the business to prepare them for the money going out of the business. The Monthly net cash flow starts off with a positive for September at  £100 this is a huge improvement from the previous months. The monthly net cash  flow goes to - £2,900 a huge drop in October from previous months. This is because of the raw material costs have increased. September’s closing balance stays at a positive  £3,900 and increase of  £100 from the previous months. On the other hand, for October although it stays at a positive the closing balance drops to  £1,000 and this is because of the raw materials costs. November and December The opening balance starts to drop from the previous month to now at  £1,000 in November. This is because of the raw material costs from the previous months. This drops even more in December to - £18,900. This is having a very bad impact on the business as they are not starting off with a positive amount. This will not allow them to operate. This is the only month that has had a negative opening balance and will affect the business. The sales revenue for November is at  £21,000 which is a strong amount and has had an improvement from the previous months. This sales revenue has a bigger improvement and goes to  £22,000 in December. This is having a good impact on the business. The raw materials cost stays at  £12,500 which will have a bad impact on the business if the total price of expenditure doesn’t go higher than the previous month. New cooking equipment is one of fresh business irregular expenditure. On November  £20,000 went out of business. This is really bad for the business. Irregular expenditure is bad for the company because you don’t know when it going to happen or how much going to cost. Although this decreases to  £20,900 in the next month this will still have a bad impact on the business and may cause them to go bank-corrupt. The monthly net cash flow for November is at - £19,900 and this is having a bad impact on the business. For the last month the monthly net cash flow goes to a positive  £1,100. However, this still won’t help the business. The closing balance for November is at - £18,900 a huge decrease from the  positive previous month and the closing balance for the last month is at - £17,800 a decrease from the previous month but will not help the business. Finally, the total opening balance for this year is at  £131,400. This figure has been affected by the negative amount at the last month. The total monthly net cash flow for the whole year is at - £27,800 this is because of the over expenditure and has affected the business earning them a smaller and even negative closing balance. The total closing balance for the year is at  £103,600 and this has been affected by the negatives. Key words Total expenditure: All of cost added up. The total amount of money that is spent on a product in a given time period Monthly net cash flow: Equals cash receipts minus cash payments. In simple English it tells you if you’re making a profit or loss. Total income: All of your income added up (income is money you get from your goods and service) Cash outflows: The total money going out from a company in a given period of time. Cash outflows include expenses such as salaries, supplies, and maintenance, and lease Cash inflows: The total money going in to a business or company for sales of goods and services. Cash outflows include income such as sales revenue, loan etc.

International Business Cultural Diversity Management Essay

International Business Cultural Diversity Management Essay You are required to assist the work of TATA Ltd. One of the worlds most dynamic and trusted business conglomerates,  Tata  has more than a century of experience in the UK and a growing presence in several business sectors. The company wants to improve its efficiency throughout its divisions and believes that using cultural diversity factors may be the key. 3). Cultural Differences are held responsible for many failures in mergers and acquisitions (MA). Critically discuss which business aspects are likely to be affected. Managing and working with multicultural teams requires an understanding of cultural diversity to create an effective team. Critically discuss the issues This essay will discuss about Tata, their MA, the impacts of cultural differences and the different aspects they have to consider to build an international team. Usually used under the name of MA (Mergers Acquisitions), this term refers to a consolidation of companies. Merger is a strategic alliance whose the aim is to create a new entity. An acquisition is the fact to acquire a new company by purchasing it. Tata wants to improve its efficiency throughout its divisions and believes that using cultural diversity factors may be the key. Tata is an Indian group founded in 1868 by the Indian entrepreneur Jamsetji Tata and currently run by the Irish businessman Cyrus Pallonji Mistry. Nowadays, Tata is a powerful international group operating in more than 80 countries by a diversification strategy (thanks to the MA). The groups activity is divided into numerous sectors, for instance: technology, cars, services, electricity, consumer products, beverages, steel, materials and chemicals. Indeed, this international group has acquired since about ten years numerous companies which have cost altogether several milliards of dollars. These are the main takeovers: Tetley Group (UK) in 2000: tea Regent Hotel (Indian) in 2002: hotels Hughes Telecom (Indian) in 2002: telecom Daewoo Commercial Vehicle Company (Korean) in 2004: cars NatSteel Asia (Singaporean) in 2005: steel Brunner Mond (UK) in 2005: chemicals Eight O Clock Coffee Company (USA) in 2006: coffee Jaguar and Land Rover (UK) in 2008: cars Source: Tata Group 2012 Tata wants to improve its performance thanks to MA but to reach that goal; it has to consider that cultural differences affect numerous business aspects in this kind of strategic alliance. For Adler and Gundersen (2008), cultural differences may have positives and negatives effects on a multicultural teams performance. Indeed, the cross-cultural differences are linked to performance. The cultural differences are one of the most important features to take into account to succeed in a M&A; maybe the most important. The culture is complex; it is a shared system of attitudes, beliefs and behaviour. Nowadays, the business is globalized and international; we can almost talk about a business culture run by the globalization (Hopper, 2007). Indeed, the world is not becoming smaller but people and their culture are moving closer. Tata has to understand that ignore the cultural differences would be a terrible mistake: the MA would not work or would not be as effective as expected. Tata should not make the same mistakes than the Merger between Chrysler (American) and Daimler-Benz (German) in 1998. It is a well-known example of how cultural differences can be held responsible for a failure in a MA. According to Vlasic and Stertz (2001), the main cause of this failure was the cultural differences. Indeed, Chrysler and Daimler had the same objectives but the cross-cultural gap between both was too deep and not enough considered to succeed (Schneider, 1997). Strategically, the merger was a good deal for both. However little by little, the cultural differences have led the merger to failure. This strategic alliance finished by an important economical (more than half a billion dollars) and social cost (redundancy). This example is the perfect proof than cultural differences badly assimilated can bring a MA to poor productivity and sometimes failure. Many mergers and acquisitions fail. Indeed, the average rate of failure is between 40-80%. According to Trompenaars and Asser (2010), it varies between 20% and 33%. Stahl and Voigt (2008) say that this rate of failure is relatively high and the impact of cultural differences remain most of the time, badly assimilated. Shareholders have tendency to underestimate the cultural factors in mergers and acquisitions. For Ferraro (2002), one of the biggest mistakes is to think that if a person is successful in his job, he will necessarily succeed in an environment culturally different. According to Harris and Moran (2000), culture acts on communication, strategies, relations, organizations and structures. Indeed, the cultural differences affect numerous business aspects such as organisation, financial performance, negotiation, communication, ways of getting work done, the human relationships, the time, the environment and the management. Insufficient awareness of cultural differences may provoke damages. (Trompenaars and Hampden-Turner 1997, p. 10). In fact, cultural differences badly mastered can lead to: misunderstandings, incorrect exchange of information, ruined negotiations, loss of sales, poor labour relations, a loss of talented employees, limited co-operation, hostility and rivalry. (To change: Sian Taylors lesson). Joynt and Morton (1999) state that the cultural differences have a strong impact on the organisation. In fact, a MA may provoke numerous changes in the organisation structure. When there are hierarchical and organisational changes, the shareholders may have some difficulties to agree with the opinion or the status of the new colleagues. It may cause tensions and frictions between them. The human resources services and the management team field have an essential role to play in this kind of strategic alliances. (Source bad example to extend and to change) Culture has also a strong impact on the productivity. The cultural aspects may affect numerous other business aspects which influence indirectly on the performance of the MA in particular making benefits (Stahl and Voigt, 2005). For them, To increase effectiveness across cultures, training must be the focus of the job, while education thought of with reference to the individual, and development reserved for organizational concerns.(To change?) Culture differences badly assimilated product poor results and performance. However, the relationships between the MA performance and the cultural differences are not as easy as it could seem. (To Change and extend) King et al (2004) state that despite decades of research, what impacts the financial performance of firms engaging in MA activity remains largely unexplained. (To change?) The negotiation is also an aspect affected by the cultural differences. For instance, bad master of the culture or the local customs can lead to misunderstandings and confusions (Schein, 1993). It involves the meetings, the contacts and all the components of the negotiation between two interlocutors culturally different. Each culture has its own way to negotiate even though certain are similar. For instance, the Indians employees of Tata are used to negotiate because it is something daily and at every moment of the day in India. They rarely say no by politeness and sometimes their answer may seem unclear, that is why, a foreign negotiator should be able to decode the non-verbal language to know what they really think (such as cross legs or arms). (relation with Tata? + bad example) Another aspect that can be a problem is communication. Javidan and House (2002) state that during a MA, cultural differences may have negatives impacts on communication. For instance, Tata took this aspect into account for the acquisition of Jaguar and Land Rover. The Indian group had to retain a good communication with the employees of Jaguar and Land Rover. According to Schein (1993), in a business, the dialogue is primordial. In fact, it enables to transmit the information in order to be accurate and effective. It affects numerous fields such as: the management of people, negotiation, meetings, contracts, socialising, presentations, and advertising. During a MA, the communication is a determining factor: of success or failure (Trompenaars and Asser 2010, p.10). According to Stahl and Voigt (2008), in MA, the culture strongly impact the ways of getting the work done such as the levels of formality, tolerance of risk and methods of decision making (Communicaid 2008). In fact, each culture has his own way to do the job. Tata has to consider this fact, in particular for MA with other cultures like European (Tetley group (UK)) or American (Eight O Clock Coffee Company). Cultural differences may be barriers to the performance when they negatively impact the relationships between people and especially between the employees (to extend) of a MA. In particular, the way of dealing with conflict (To change). Often, people have a fixed idea of a particular type of person or thing, it is called a stereotype. Culture is like an iceberg. At the top, the elements we can see physically such as the behaviour, the clothing and the food. Whereas underneath, there is all the things we cannot see at the first sight such as meanings, beliefs, attitudes and values. Many human beings are influenced by their cultural roots which are very often transmitted by the family. (Too change, Sian Taylors lesson). Cross-cultural difference can have negative impacts on the human relationships (Javidan and House, 2002). According to Kleppestà ¸ (1998), we may see sometimes, the creation of in-group and out-group. (too extend). A bad entente between employees has for main consequenc e the fall of productivity. Indeed, the difference of culture does not simplify the relationships, especially when shareholders have to make important and essential choice. The cultural differences divide more than they gather, which might be problematic when shareholders have to take a single and common strategic decision. In fact, the human behaviour is an essential feature to take into account. Tata has also to take into account the time. Indeed, it is influenced by the cultural origins and determinant in the success of a MA. It can have important influences on the planning and on the way of how people manage their time. For Harris and Moran (2000), the definitions of time vary according to the culture, some are exact and others are relative. According to Trompenaars and Hampden-Turner (1997), primitive societies just consider the matter of the before and the after whereas the educated societies judge the matter of time differently. For them, the time is an infinite succession of event. (To change) For instance, Tata purchased Jaguar and Land Rover which are British companies. Both cultures have a different on the notion of time. Tata is an Indian group and culturally their relation with the time is more relax and less in a rush than the European philosophy. For example, the Indian group would not hesitate to spend a long time to meet their employees whereas the British wou ld do it as quick as possible. All the more than Tata has always considered importantly the social aspect with its employees. Moreover, one of main cultural difference is the attitude of people with the environment. Some cultures have more importance for their own human-being life rather than other cultures attach more importance to the world in general than to the individuals.(To change) (Trompenaars and Hampden-Turner, 1997). Harris and Moran (2000) say that persons culturally different live and organize their environments in their own specific way. However, Tata has to know that a team composed of different cultures may have numerous potential benefits. Indeed, culture is also an opportunity and a source for the Indian group of competitive advantage. (Sian Taylor, Too change) Cultural differences may also have positives impacts on multicultural teams only if they respect certain conditions. In fact, diversity can lead to higher performance only when members of the group understand each other, and can combine and build on each other thoughts and ideas (Chell, 2001). (To change, Sian Taylors course). Cultural differences in the same organisation can also a great opportunity. (too extend)(source) Define culture is necessary to well understand what are the cultural diversities and which impacts they have on performance. For Hofstede (1980), culture is the interactive aggregate of common characteristics that influence a groups response to its environment. Cultural differences change the way people solve problems. In fact, Trompenaars and Hampden-Turner (1997) say that we can differentiate every culture individually by the way they solve problems. The cultures distinguish from each other by the specific solutions they use when there is an issue. For instance, two groups of students have an essay to hand in for a due date. The first group is French and the other one is American. Both groups are late but they react differently because they are culturally different: the American group will reach the deadline and scarify the quality whereas the French group will go over the deadline and try to improvise. According to Chell (2001), the synergy in a multicultural team can improve significantly the performance and increase benefits. A multicultural team in which members live well together will be more productive and effective. Indeed, the cultural differences can create potential competitive advantages such as a better productivity, innovation, learning or ambience. It may also increase the productivity. Indeed, in a same situation, employees culturally different can have different way of thinking and therefore bring several solutions and improve the performance (Adler and Gundersen, 2008, p.134). In fact, multicultural team means wider range of opinions, ideas and consequently encourage the innovation. According to Adler and Gundersen (2008), this creativity enables to find better solutions to problems, take better decisions. Moreover, Chell (2001) think intercultural team is strength for a team. In fact, different nationalities enable to master different languages and consequently a bigger flexibility geographically and linguistically. Moreover, being cultural different may also enable to learn new things such as another way of managements or another ways of getting the work done. A multicultural team were the members understand each other enable to have a better ambience in the firm. The role of the manager has a strong impact on the ambience which is an essential feature to reach the synergy (Adler and Gundersen, 2008). If Tata wants to succeed in a MA with cultural differences, they should consider how to organize and manage an intercultural team. Managing and working with multicultural teams requires an understanding of cultural diversity to create an effective team. A multicultural team needs some features essential to be successful for example: the motivation to communicate, a good relationship between each members and a reciprocal respect. (To change Sian Taylors courses) Additionally, Tata must be aware of the role of the manager: it has changed due to the new cultural diversity in a same team (Harris and Moran, 2000). Nowadays, he must be skilful, master several languages and know the cultural features of his employees and the shareholders. The role of the manager is also to avoid the cultures shock and cultures clashes between the employees. According to Ruben (1983), the multinational manager should have seven skills to gather the employees strengths and bring them to the performance: tolerant, respectful, have good interpersonal skills, not to be prejudiced against people, feel empathy, observant and persevering. For Trompenaars and Asser (2010), the managers have a tendency to focus on the results of deal rather than the way the people reach together these objectives. The human dimension and the cultural differences are unfortunately used to be underestimated in a merger or acquisition. They are in particular ignored by the managers who prefer f ocus on results and performance rather than the way the job is done. Moreover, the notion of feedback (between manager and employees) is essential to fix the differing and underline the good things. Indeed, their first objective of the manager is to reach the synergy: to gather all the shareholders and bring them to an only and same goal with this kind of tools. Furthermore, the cultural differences strongly affect the way of managing people. Indeed, MA often involve the mix of firms and consequently, the mix of employees who are sometimes culturally different. Especially because culture is not something we cannot figure out at the first sight; it is something inside us. Trompenaards and Hampden-Turner states, it is not on surface but deep in every person. (Too change p.3). According to Tylor (1924), culture is not something simple or limited to one dimension in one field, it is the entire contrary. Indeed, he states that the culture is composed by numerous components such as: habits, language, religion, belief and morals. To create an effective team, the team have to understand the culture of each member and learn cross cultural knowledge (Harris and Moran, 2000). The creation of a multicultural effective team takes time because the manager must make aware each members of his own culture (Chell, 2001). One of the essential points is to resp ect the others cultures and the fact to be different because the culture takes an important place in peoples lives. Understand another culture also means be respectful about these differences. In fact, Chell (2001) say that the members have to have in mind that there is no dominant culture and everybody is equal whatever his origin. Indeed, according to them; we have to master early our culture before learning to know all the features of another one. Schein (1993) said We have to learn to listen to ourselves before we can really understand others. It is called the polycentrism: attempt to overcome your own cultural assumptions and to develop openness towards other cultures (To change course Sian Taylor). At the contrary the worst behaviour to adapt is to be ethnocentric: to look the word only through my own culture. (To change) Moreover in multicultural team, some cultures are more likely to fit with one than another. In a globalized world, the cross-cultural relationship has change d the way of managing a team. To conclude, Tata must be conscious that intercultural issues not well mastered may lead to poor productivity and performance. The cultural differences can affect negatively the business aspects and the performance. However, an effective multicultural team can have a positive impact on the performance. Indeed, if the cross-cultural differences are considerate and if the members collaborate, the cultural differences may become a great opportunity for the Indian group. Moreover, the future of a MA depends on the ability of a multicultural team to gather their strengths in the same project even if they are culturally different. That is why the role of the manager is crucial. Indeed, bring a multicultural team to the synergy is the main aim and role of the management team. Tata has to focus on the fact that diversity can lead to higher performance only when members of the group understand each other and work together.

God Defines Gender Roles in American Society :: Exploratory Essays Research Papers

God Defines Gender Roles in American Society What are men's and women's roles in society? Are men and women equal in ability and opportunity? Should they be equal or do they have distinct roles they should play? In this day and age, people like to be "politically correct" by attempting to make both sexes equal. Most people feel that it is unfair to say that men can do certain activities better than women and women can do other activities better than men, but is it actually unfair, or has God actually made men and women differently and given them different roles in life and society? As was stated, most people like to consider males and females equal in ability and in what their roles should be in society, but I don't think that is actually the case. God has made men and women differently - HE has made them to fit certain roles HE has defined. The Bible talks a lot about God's roles for men and women. Genesis, the first book of the Bible, talks about Creation and how sin (disobedience to God) entered the world. When God created everything, it was perfect and good. Right after Adam and Eve (the first man and woman) disobeyed God, God kicked them out of the perfect place he had made for them called the Garden of Eden. Genesis 3:16-19 says: "To the woman He said, 'I will greatly multiply your pain in childbirth, in pain you shall bring forth children; yet your desire shall be for your husband, and he shall rule over you.' Then to Adam He said, '... Cursed is the ground because of you; in toil you shall eat of it all the days of your life. Both thorns and thistles it shall grow for you; and you shall eat the plants of the field; by the sweat of your face you shall eat bread...'" This is the first example of God's giving roles to men and women. He said that women would give birth to children (and, obviously, raise them), while men will take care of the land and work it for food. Many people today believe that since the Bible was written quite a long time ago that it doesn't apply to the world now and that the roles God has given men and women are changing, but that's not true. Just because something is old doesn't mean it's irrelevant to the world today.

Toys R Us and Subsidiaries Essay -- GCSE Business Marketing Coursework

Toys R Us and Subsidiaries Running Head: Toys "R" Us Financial Analysis Note: Consistent with the financial report, all amounts are expressed in millions except per share data. Ernst & Young, LLP, independent auditors for Toys "R" Us Inc. and Subsidiaries issued an unqualified opinion on the company’s financial statements as of February 1, 1997 and on the consolidated results of operations and cash flows for the three years ending February 1, 1997, February 3, 1996 and January 28, 1995. The report by the independent auditors and their issuance of an unqualified opinion serves to provide reasonable assurance to stockholders, management, regulatory agencies and the public, that the financial statements are materially correct. Materiality is interpreted to mean that there are no unrecorded adjustments which would impact the decisions or opinions of the readers of these financial statements. The inclusion of the auditors’ report in the year-end financial report lends credibility to the presentation and allows the users including investors and potential investors to rely on the information as presented. Common Stock & Treasury Stock The company does not have preferred stock and has not declared or paid dividends on its common stock. As of February 1, 1997, Toys "R" Us, Inc. and subsidiaries had authorized 650 shares of par value $.10 common stock, of which 300.4 shares were issued. 12.6 shares were held in treasury stock leaving 287.8 shares issued and outstanding. The book value of the common stock issued and outstanding was $14.56 which is down from February 3, 1996 at which time the book value was $18.8. The total paid-in capital for common stock was $ 518.8 as of February 1, 1997 and $572.8 as of February 3, 1996. The average price per share received by the company for all common stock issued since inception of the corporation as of February 1, 1997 was $ 1.73. Ratio Analysis "There’s a saying that the nice thing about standards is that there are so many of them to choose from." (Maciag, 1998) It is important to choose carefully the ratios to be analyzed to be sure that there is relevance between the data and the conclusions drawn from it. When choosing industry standards, it is important to select like industries with commonalties that support comparison of results. It would not be appropriate to compare the financial statement of t... ... beating the industry averages for inventory turns. In addition their receivables consistently exceed industry standard by a significant amount. References Enhanced Analytics. (May 16, 1999). S&P Personal Wealth. Available: http://www.personalwealth.com. Industry Info. (May 16, 1999). S&P Personal Wealth. Available: http://www.personalwealth.com. Maciag, Gregory, A. (April 13, 1998). A wake-up cal for industry standards. National Underwriter. P29. Meigs, Robert F.; Williams, Jan R.; Haka, Susan F.; Bettner, Mark S., (1999) Accounting. p 619. Mills, John R.; Yamamura, Jeanne H. (October 1998). The power of cash flow ratios. Journal of Accountancy. V186 n4 p53(7). Stocksheet: Media General Quick Source Data-One Wev Page—Toys R Us INC. (5/16/99) Available: http://www.stocksheet.com. Thomson Investors Network Company Report: Toys "R" Us Inc. (5/15/99). Available: http://www.thomson.com. Vital Stats. (May 16, 1999). S&P Personal Wealth. Available: http://www.personalwealth.com. Wallstreet Research Net Report: Toys R Us Inc. (May 7, 1999). Available: http://www.wsrn.com. Berry, Donna Gorski. (Mid-Oct 1998). Mouths of the millennium. Dairy Foods. 73.74.

Can At-Risk Children be Helped? Essay -- Crime, Juvenile

The 2010 Census showed that over 74 million children (or one-fourth of the total population) reside in the United States—with almost one-fourth being children under the age of 12 and one-fourth being youth ages 12-17 (Federal Interagency on Child and Family Statistics, 2011). Many of the decisions a young person makes can affect the rest of his or her life—and juvenile crime is just one of the bad decisions a young person can make. This essay covers the issue of juvenile crime, social work’s involvement, and my reflections on this issue. The Issue of Juvenile Crime According to the Federal Interagency Forum on Child and Family Statistics, in 2009 youth ages 12-17 committed more than 275,000 serious violent crimes (2011). Many factors are known to contribute to youth crime, including a lack of parental involvement their child’s life; maltreatment; failure to adhere to social norms; and untreated health/mental issues. The old â€Å"Boys will be boys† adage by a parent is not an acceptable excuse for juvenile misbehavior (Segal, Gerdes, and Steiner, 2010). Youth need positive role models in their lives. If a young person’s parents are not positive role models, the child may turn to a life of crime. Sometimes, however, maltreatment by a parent is a contributing factor to juvenile crime. Those suffering from maltreatment tend to internalize their feelings, causing them to exhibit symptoms of â€Å"anxiety, depression, or suicidal behavior† (Maschi, Morgen, Hatcher, Rosata, and Violette, 2009). Internalization of feelings can lead to the externalization of unacceptable behaviors. Maltreated youth can become aggressive and rebellious (Maschi, et al, 2009). Untreated health or mental issues can also contribute to juveniles’ involvement in cri... ...s.gov Gerdes, K.E. & Segal, E. (2011). Importance of empathy for social work practice: integrating new science. Social Work, 56(2), 141-148. Harris, A. (2009). The role of power in shaming interactions: how social control is performed in a juvenile court. Contemporary Justice Review, 12(4), 379-399. Doi: 10.10880/10282580903342854 Maschi, T., Morgen, K., Hatcher, S., Rosato, N., & Violette. (2009) Maltreated children’s thoughts and emotions as behavioral predictors: evidence for social work action. Social Work, 54(2), 135-143. Segal, E., Gerdes, K., & Steiner, S. (2010). An introduction to the profession of social work. Third Edition. Belmont, CA: Brooks/Cole, Cenage Learning. Schwalbe, C., Hatcher, S., & Maschi, T. (2009). The effects of treatment needs and prior social services on juvenile court decision making. Social Work Research, 33(1), 31-40.

The two heroes of industrialization

The Two Heroes of Industrialization During the late 1800s, many people began to start their own companies. Two of the most famous entrepreneurs, Andrew Carnegie and John D. Rockefeller, were the most renown of these people. Their success is seen through all the things that are named after them – the Carnegie Library, Carnegie Hall, Carnegie Mellon University, Rockefeller Foundation, Rockefeller Center, and many more. Though they may seem very much alike, these two businessmen share differences as well.Despite the fact that Andrew Carnegie and John D. Rockefeller gained their position in two diverse ways, they both had illustrious companies with discontented workers. These industrialists certainly got to where they were in two very different ways. Carnegie is famous for going from â€Å"rags to riches. † He defines the American Dream. Starting out as an immigrant, he worked for the Pennsylvania Railroad Company. He was then promoted, and was able to buy stock. From the i nvestment money, he started his own company – Carnegie Steel Company.From there, he went on to be a ealthy entrepreneur and philanthropist. Rockefeller, on the other hand, achieved his position In a more realistic way. Together with other people, he formed illegal trusts. Luckily, it proved to be a success. His wealth came from his famous company, Standard 011 Company. After the founding of his company, he sold oil for low prices In order to drive out his competitors, then once he had a monopoly, he would raise the price again. Rockefeller proves to be model for economic success. Since these Industrialists had large companies, they needed workers to run them.Carnegie and Rockefeller did not pay them much, or else It wouldnt be profitable. The workers had six to seven day work weeks, no holidays or vacations, and had to come to work on sick days. The Injuries were common, for many of the workers were Inexperienced. The laborers at this point were unsatisfied, and had to stand up for themselves. They formed labor unions In order to fight the companies. A few people died because of the attack between the workers and companies. Carnegie and Rockefeller both went through laborers' complaints, dissatisfaction, and aggression.These two businessmen reached their economic success In unlike ways, yet both had eminent companies and displeased workers. Without their efforts, the world wouldn't be where It Is right now. Thanks to them and their contributions, many companies, colleges, and organizations have been established. Rockefeller, on the other hand, achieved his position in a more realistic way. success. His wealth came from his famous company, Standard Oil Company. After the founding of his company, he sold oil for low prices in order to drive out hisSince these industrialists had large companies, they needed workers to run them. Carnegie and Rockefeller did not pay them much, or else it wouldn't be profitable. come to work on sick days. The injuries were co mmon, for many of the workers were inexperienced. The laborers at this point were unsatisfied, and had to stand up for themselves. They formed labor unions in order to fght the companies. A few people These two businessmen reached their economic success in unlike ways, yet both wouldn't be where it is right now. Thanks to them and their contributions, many

Hydraulic Design of Small Hydro Plants

Version 2 STANDARDS/MANUALS/ GUIDELINES FOR SMALL HYDRO DEVELOPMENT Civil Works – Hydraulic Design Of Small Hydro Plants Lead Organization: Sponsor: Alternate Hydro Energy Center Indian Institute of Technology Roorkee Ministry of New and Renewable Energy Govt. of India May 2011 AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  1 1. GUIDELINES FOR HYDRAULIC DESIGN OF SMALL HYDRO PLANTS This section provides standards and guidelines on the design of the water conductor system.This system includes; head works and intake, feeder canal, desilter (if required), power canal or alternative conveyance structures (culverts, pipelines, tunnels, etc), forebay tank, penstock and surge tank (if required) up to the entry of the turbine, tailrace canal below the turbine and related ancillary works. 1. 1 HYDRAULIC DESIGN OF HEAD WORKS In general head works are composed of three structural components, diversion dam, intake and b ed load sluice. The functions of the head works are: Diversion of the required project flow from the river into the water conductor system.Control of sediment. Flood handling. Typically a head pond reservoir is formed upstream of the head works. This reservoir may be used to provide daily pondage in support of peaking operation or to provide the control volume necessary for turbine operation in the water level control mode. This latter case would apply where the penstock draws its water directly from the head pond. Sufficient volume must be provided to support these functions. There are three types of head works that are widely used on mini and small hydro projects, as below: Lateral intake head works Trench intake head worksReservoir / canal intakes Each type will be discussed in turn. 1. 1. 1 Head Works with Lateral Intakes (Small Hydro) Head works with lateral intakes are typically applied on rivers transporting significant amounts of sediment as bed load and in suspension. The f unctional objectives are: To divert bed-load away from the intake and flush downstream of the dam (the bed load flushing system should be operable in both continuous and intermittent modes). To decant relatively clean surface water into the intake. To arrest floating debris at intake trashracks for removal by manual raking.To safely discharge the design flood without causing unacceptable upstream flooding. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  2 The following site features promote favourable hydraulic conditions and should be considered during site selection: The intake should be located on the outside of a river bend (towards the end of the bend) to benefit from the spiral current in the river that moves clean surface water towards the intake and bed load away from the intake towards the centre of the river.The intake should be located at the head of a steeper section of the river. This will promote remo val of material flushed through the dam which may otherwise accumulate downstream of the flushing channel and impair its function. Satisfactory foundation conditions. Ideal site conditions are rare, thus design will require compromises between hydraulic requirements and constraints of site geology, accessibility etc. The following guidelines assume head works are located on a straight reach of a river. For important projects or unusual sites hydraulic model studies are recommended.A step by step design approach is recommended and design parameters are suggested for guidance in design and layout studies. Typical layouts are shown in Figures 2. 2. 1 to 2. 2. 3. 1. 1. 2 Data Required for design. The following data are required for design: Site hydrology report as stipulated in Section 1. 3 of this Standard giving: – Qp (plant flow) – Q100 (design flood flow, small hydro) – Q10 (design flood flow, mini hydro) (data on suspended sediment loads) – Cw – H -Q Curves (W. L. rating curves at diversion dam) Topographic mapping of the site including river bathymetry covering all head works structure sites.Site geology report. 1. 1. 3 Site Selection: Selection of the head works site is a practical decision which involves weighing of several factors including hydraulic desiderata (Section 2. 2. 1/1. 0), head optimization, foundation conditions, accessibility and constructability factors. Given the importance of intake design to the overall performance of the plant it is recommended that an experienced hydraulic engineer be consulted during studies on head works layout. 1. 1. 4 Determination of Key Elevations: AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  3For the illustrative example: Qp = 10. 0 m3/s Determine V0 = 0. 5 Q0. 2 (= 0. 792, say 0. 80 m/s) (= 12. 5 m2) A0 = Q ? V0 A0 H= (= 1. 77 m, say 1. 80 m) 4 Assume L = 4H (= 7. 08 m, say 7. 0 m) ye = greater of 0. 5 yo o r 1. 5 m (= 1. 80m) yd = L. S (= 0. 28 m) NOL = Z0 + ye + yd + H NOL = 97. 5 + 1. 80 + 0. 28 + 1. 80 (=101. 38m, say 101. 50 m) Sill = NOL – H (= 99. 7m) Crest of weir or head pond NOL = 101. 5 m Height of weir = 4. 0 m These initial key elevations are preliminary and may have to be adjusted later as the design evolves. 1. 1. 5 Head Works LayoutThe entry to the intake should be aligned with the river bank to provide smooth approach conditions and minimize the occurrence of undesirable swirl. A guide wall acting as a transition between the river bank and the structure will usually be required. Intake hydraulics are enhanced if the intake face is slightly tilted into the flow. The orientation of the intake face depends on river bank topography, for straight river reaches the recommended values for tilt vary from 10o to 30o depending on the author. When this angle becomes too large the intake will attract excessive amounts of sediment and floating debris.It is recommended that t he sill level of the intake is kept sufficiently higher than the sill level of the under sluice. The under sluice should be located adjacent to the intake structure. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  4 For development of the head work plan, it is recommended that the following parameters be used for layout: Axis of intake should between 100 ° to 105 ° to axis of diversion structure The actual inclination may be finalized on the basis of model studies. Divide wall, if provided, should cover 80% to 100% of the intake.Assume flushing flow equal to twice project flow then estimate the width and height of the flushing gate from orifice formula,: Example should be in appendix. Qf = 0. 6 ? 0. 5W2 Where: Qf = flushing flow W = gate width H = gate height (= 0. 5W) Yo = normal flow depth as shown in 2. 2. 1. 1/2. 0 Sill should be straight and perpendicular to the flow direction. In the sample design (Fig. 2 . 2. 1. 1) the axis of the intake = 105 ° & Qf = 2. 0? 10. 0 = 20m3/s ? 20. 0 = 0. 6 ? 0. 5 W2 ? W = 2. 8 m (say 3. 0m) and H = 1. 5 m. 1. 1. 6 Flood Handling, MFL and Number of Gates.For small hydro a simple overflow diversion weir would be the preferred option if flood surcharge would not cause unacceptable upstream flooding. For purpose of illustration, the following design data are assumed (see Figure 2. 2. 2): Design flood, Q100 = 175 m3/s A review of reservoir topography indicated that over bank flooding would occur if the flood water level exceeded 103. 0 m. Select this water level as the MFL. This provides a flood surcharge (S) of 1. 20 m. Assume weir coefficients as below: Gate, Cw = 1. 70 – – – sill on slab at river bottom. Weir, Cw = 1. 0 – – – – – – -ogee profile. Assume gate W/H ratio = 1:2 H = 4. 0 m ? W = 4. 8 (say 5. 0 m) MFL. = NOL + 1. 50 (= 103. 0m) Qgate = Cw. W. (MFL – ZS)1.. 5 Qweir = Cw. L w. S1. 5 Capacity check for MFL = 103. 0 m No. of Length of Overflow QG Gates Section (m) (m3/s) 0 35. 0 0. 0 1 29. 0 109. 6 QW (m3/s) 82. 8 68. 6 QT (m3/s) 82. 8 178. 2 >175 AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  5 Therefore one gate is sufficient. Where: MFL = Maximum flood level (m) NOL = Normal operating level (m) S = flood surcharge above NOL (m)W = width of gate (m) H = height of gate (m) ZS = elevation of gate sill (m) = weir coefficient (m0. 5s-1) Cw QG, QW, QT = gate, weir and total flows The flow capacity of the sediment flushing gate may also be included in calculating flood handling capacity. 1. 1. 7 Diversion structure and Spillway Plains Rivers: Stability of structures founded on alluvial foundations typical of plains rivers, is governed by the magnitude of the exit gradient. The critical gradient is approximately 1. 0 and shall be reduced by the following safety factors: Types of foundationS hingles / cobbles Coarse sand Fine sand Safety factor 5 6 7 Allowable Exit Gradient 0. 20 0. 167 0. 143 Also diversion structures on plains rivers will normally require stilling basins to dissipate the energy from the fall across the diversion structure before the water can be returned safely to the river. Design of diversion weirs and barrages on permeable foundation should follow IS 6966 (Part 1). Sample calculations in Chapter 12 of â€Å"Fundamentals of Irrigation Engineering† (Bharat Singh, 1983) explain determination of uplift pressure distributions and exit gradients.Further details on structural aspects of design are given in Section 2. 3. 3 of this Standard. Mountain Rivers: Bedrock is usually found at relatively shallow depths in mountain rivers permitting head works structures to be founded on rock. Also the beds of mountain rivers are often boulder paved and are much more resistant to erosion than plains rivers. Therefore there may be no need for a stilling basin. The engineer may consider impact blocks on the downstream apron or simply provide an angled lip at the downstream end of the apron to â€Å"flip† the flow away from the downstream end of the apron.A cut-off wall to bed rock of suitable depth should AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  6 also be provided for added protection against undermining by scour. The head works structures would be designed as gravity structures with enough mass to resist flotation. For low structures height less than 2. 0 m anchors into sound bedrock may be used as the prime stabilization element in dam design. Stability and stress design shall be in accordance with requirements of Section 2. 3. 3 of this Standard. 1. 1. 8 Sediment Flushing Channel To be reviewedThe following approach is recommended for design of the flushing channel: Select flushing channel flow capacity (Qf) = 2? Qp Estimate maximum size of sediment ente ring the pocket from site data or from transport capacity of approaching flow and velocity. In case of diversion weir without gates assume sediment accumulation to be level with the weir crest. (Assume continuous flushing with 3? Qp entering the pocket, for this calculation). Establish entrance sill elevation and channel slope assuming an intermittent flushing mode (intake closed) with Qs = 2Qp, critical flow at the sill, supercritical flow downstream (FN ? 1. 0) and a reservoir operating level 0. 5m below NOL. Determine slope of channel to provide the required scouring velocity, using the following formula which incorporates a safety factor of 1. 5: i = 1. 50 io d 9/7 i0 = 0. 44 6 / 7 q Where: io = critical scouring velocity d = sediment size q = flow per unit width (m3/s per m) Verify that flow through pocket in continuous flushing mode (Qs = 3Qs) will be sub critical, if not lower entrance sill elevation further. Determine height of gate and gate opening based on depth of flow at gate location and corresponding gate width. Increase the above theoretical gate height by 0. 5 m to ensure unrestricted open channel flow through the gate for intermittent flushing mode and a flushing flow of 2 Qp. For initial design a width to height ratio of 2:1 for the flushing gate is suggested. 1. 1. 9 Intake/Head Regulator: In intake provides a transition between the river and the feeder canal. The main design objectives are to exclude bed-load and floating debris and to minimize head losses. The following parameters are recommended: Approach velocity at intake entrance (on gross area) 0. 20 Ve = 0. 5 Q p m / s For trashracks that are manually cleaned, V should not exceed 1. 0 m/s.AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  7 Convergence of side walls 2. 5:1 with rate of increase in velocity not exceeding 0. 5 m/s per linear m. †¢ Height of sill above floor of flushing channel (ye) = greater of 1. 5 m or 50% flow depth. †¢ The floor of the transition should be sloped down as required to join the invert of the feeder canal. Check that the flow velocity in the transition is adequate to prevent deposition in the transition area. If sediment loads are very high consider installing a vortex silt ejector at the downstream end of the transition. Provide coarse trashracks to guard entry to the head gate. The trashrack would be designed to step floating debris such as trees, branches, wood on other floating objects. A clear spacing of 150 mm between bars is recommended. Trashrack detailed design should be in accordance with IS 11388. †¢ The invert of the feeder canal shall be determined taking into consideration head losses through the trashrack and form losses through the structure. Friction losses can be omitted as they are negligible: V2 Calculate form losses as: H L = 0. 3 2 2g Where: V2 = velocity at downstream end of contraction.Calculate trashrack losses as: 4/3 V2 ?t? H L = K f ? ? . Sin? . 2g ?b? Where: Kf = head loss factor (= 2. 42 assuming rectangular bars) T = thickness of bars (mm) B = clear bar spacing (mm) ? = angle of inclination to horizontal (degrees) V = approach velocity (m/s) 1. 1. 10 References on Lateral Intakes and Diversion Weirs. IS Standards Cited: IS 6966 (Part 1) IS 11388 USBR (1987) Singh, Bharat Nigam, P. S. Hydraulic Design of Barrages and Weirs – Guidelines Recommendations for Design of Trashracks for Intakes Design of Small Dams Fundamentals of Irrigation Engineering Nem Chand & Bros. Roorkee (1983) Handbook of Hydroelectric Engineering (Second edition) †¦.. pages 357 to 365 Nem Chand & Bros. – Roorkee (1985) 1. 1. 11 Other References: Bucher and Krumdieck Guidelines for the Design of Intake Structures for Small Hydro Schemes; Hydro ’88/3rd International Conference on Small Hydro, Cancun – Mexico. Bouvard, M. Mobile Barrages and Intakes on Sediment Transporting AHEC/MNRE/SHP Standards/ C ivil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  8 Razvan, E. 1. 2. Rivers; IAHR Monograph, A. A. Balkema – Rotterdam (1992) River Intakes and Diversion DamsElsevier, Amsterdam (1988) SEMI PERMANENT HEADWORKS (MINI HYDRO) For mini hydro projects the need to minimize capital cost of the head works is of prime importance. This issue poses the greatest challenge where the head works have to be constructed on alluvial foundations. This challenge is addressed by adoption of less rigorous standards and the application of simplified designs adapted to the skills available in remote areas. A typical layout is shown in Figure 2. 2. 3. 1. 2. 1 Design Parameters Hydraulic design should be based on the following design criteria: Plant flow Qp) = QT + QD Where: QT = total turbine flow (m3/s) QD = desilter flushing flow (= 0. 20 QT) m3/s QFC = feeder canal flow (= 1. 20 QT) m3/s QF = gravel flushing flow (= 2. 0 QP) Spillway design flow (SDF) = Q10 Where: Q10 = flood peak flow with ten year return period. 1. 2. 2 Layout ? To be reviewed Intake approach velocity = 1. 0 m/s Regulator gate W/H = 2 Flushing channel depth (HD) = 2H + W/3 Flushing channel minimum width = 1. 0 m Assumed flushing gate W/H = 2, determine H from orifice equation, as below: Q f = 0. 53? 2 H 2 . 2 gY1 Y1 = HD for design condition Where: W width of gate (m) H = height of gate (m) Yi = upstream depth (m) = depth of flushing channel (m) HD Select the next largest manufactures standard gate size above the calculated dimensions. 1. 2. 3 Weir AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  9 Determine weir height to suit intake gate and flushing gate dimensions, as shown in Figure 2. 2. 3. For weirs founded on permeable foundations the necessary structure length to control failure by piping should be determined in accordance with Section 2. 2. 1/4. 1 of this Standard.A stepped arrangement is recommended for the downstream face of the weir to dissipate hydraulic energy. The height of the steps should not exceed 0. 5 m and the rise over run ratio should not less than 1/3, the stability of the weir cross-section design should be checked for flotation, over turning and sliding in accordance with Section 2. 3. 1. 1. 3 TRENCH INTAKES Trench intakes are intake structures located in the river bed that draw off flow through racks into a trench which conveys the flow into the project water conductor system. A characteristic of trench intakes is that they have minimum impact on river levels.Trench intakes are applied in situations where traditional headwork designs would be excessively expensive or result in objectionable rises in river levels. There are two quite different applications: on wide rivers and on mountainous streams, but the basic equations are the same for both types. The trench intake should be located in the main river channel and be of sufficient width to collect the design project flow including all flushing flows. If the length of the trench is less than the width of the river, cut off walls will be required into each bank to prevent the river from bypassing the structure.Trench weirs function best on weirs with slopes greater than 4%-5%, for flatter slopes diversion weirs should be considered. The spacing between racks is selected to prevent entry of bed load into the trench. The following terms are sometimes used in referring to trench intake designs. Trench weir, when the trench is installed in a raised embankment. †¢ Tyrolean or Caucasian intakes, when referring to trench intakes on †¢ mountainous streams. Features: AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  10 1. 3. 2 Design ParametersThe following design parameters are suggested for the dimensioning of trench weirs. †¢ Design Flows: The following design flows are recommended: Bedload flushing flo w (from collector box) = 0. 2 QT †¢ Desilter flushing flow = 0. 2 QT †¢ Turbine flow = 1. 0 QT †¢ Total design flow †¢ = 1. 4 QT Dimensional Layout AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  11 The following factors should be considered in determining the principal dimensions: length, breadth and depth of a trench weir: Minimum width (B)= 1. 25 m (to facilitate manual cleaning) Length should be compatible with river cross section. It is †¢ recommended that the trench be located across main river channel. Maximum width (B) ? 2. 50m. Trashrack bars longer than about 2. 50 m †¢ may require support as slenderness ratios become excessive. Invert of collector box should be kept a high as possible. †¢ †¢ Racks †¢ †¢ †¢ †¢ The clear spacing between bars should be selected to prevent entry of bed-load particles that are too large to be conveniently handled by the flushing system. Generally designs are based on excluding particles greater than medium gravel size from (2 cm to 4 cm).A clear opening of 3. 0 cm is recommended for design. A slope across the rack should be provided to avoid accumulation of bed load on the racks. Slopes normally used vary from 0 ° to 20 °. Rectangular bars are recommended. Bar structural dimension shall be designed in accordance with Section 2. 2. 1/5. 0 of this Standard. An appropriate contraction coefficient should be selected as explained in the following sub-section. Assume 30% blockage. Spacing between racks is designed to prevent the entry of bedload but must also be strong enough to support superimposed loads from bedload accumulation, men and equipment.This issue is discussed further in Subsection 2. 2. 3 / 2. 0. 1. 3. 3 Hydraulic Design of Trench Intake The first step in hydraulic design is to decide the width of the trench intake bearing in mind the flow capacity required and the bathymetry of the river bed. The next step in hydraulic design is to determine the minimum trench breadth (B) that will capture the required design flow. The design approach assumes complete capture of river flow, which implies, that river flow is equal to plant flow for the design condition. Hydraulic design is based on the following assumptions: Constant specific energy across racks. †¢ Effective head on screen is equal to base pressure (depth) †¢ Approach velocity is subcritical with a critical section at the entry to the structure as shown in figure 2. 2. 3/1. The set of equations proposed is based on the method given by Lauterjung et al (1989). †¢ First calculate y1: AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  12 2 y 1 = k. H0 3 – – – – – – – – – – – (1) Where: y1 = depth at upstream edge of rack Ho = the energy head of the approach ing flow k = an adjustment factor (m) m) (-) k is a function of inclination of the rack and can be determined from the following table: Values of k as a Function of Rack Slope (? ) Table: 2. 2. 1/1 ? = 0 ° 2 ° 4 ° 6 ° 8 ° 10 ° 12 ° k = 1. 000 0. 980 0. 961 0. 944 0. 927 0. 910 0. 894 ? = 14 ° 16 ° 18 ° 20 ° 22 ° 24 ° 26 ° k = 0. 879 0. 865 0. 851 0. 837 0. 852 0. 812 0. 800 Then calculate the breadth of the collector trench from the following equations (2) to (4) 1. 50 q – – – – – – – – – – – – – – (2) L= E1. E 2 C. cos? 3/2 . 2gy 1 Where: L = sloped length across collector trench (m) E1 = blockage factor E2 = Effective screen area = e/mC = contraction coefficient ? = slope of rack in degrees y1 = flow depth upstream from Equation 1. (m) q = unit flow entering intake (m3/s per m) e = clear distance between bars (cm or m) m = c/c spacing of bars (cm or m) Assu me E1 = 0. 3 (30%) blockage. â€Å"C† can be calculated from the following formula (as reported by Raudkivi) Rectangular bars: ?e? C = 0. 66 ? ? ?m? ?0. 16 ?m? .? ? ?h? 0. 13 Assume h = 0. 5 y1. This formula is valid for 3. 5> – – – – – – – – – – – – – (3) h e >0. 2 and 0. 15< < 0. 30 m m Finally, the required breadth (B) can be determined as below: B = L cos ? – – – – – – – – – – – – -(4) AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  13 1. 3. 4 Hydraulic Design of Collector Trench Normally a sufficient slope on the invert of the trench is provided to ensure efficient flushing of bed-load particles that would otherwise accumulate on the invert of the trench. A suitable scouring slope can be estimated from the following equation: Ss = 0. 66 d 9 / 7 6/7 qo Where: d = sediment size (m) qo = flow per unit width (Q/B) at outlet of trench (m3/s per m) Ss = design slope of trench invert.The minimum depth of the trench at the upstream and is normally between 1. 0m to 1. 5 m, based on water depth plus a freeboard of 0. 3 m. For final design the flow profile should be computed for the design slope and the trench bottom profile confirmed or adjusted, as required. A step-by-step procedure for calculating the flow profile that is applicable to this problem can be found in Example 124, page 342-345 of â€Å"Open-Channel Hydraulics† by Ven. T. Chow (1959). In most cases the profile will be sub critical with control from the downstream (exit) end.A suitable starting point would be to assume critical flow depth at the exit of the trench. 1. 3. 5 Collector Chamber The trench terminates in a collector box. The collection box has two outlets, an intake to the water conductor system and a flushing pipe. The flushing pipe must be design with the capacity to flush the bed-load sediment entering from the trench, while the project flow is withdrawn via the intake. The bottom of the collection box must be designed to provide adequate submergence for the flushing pipe and intake to suppress undesirable vortices.The flushing pipe should be lower than the intake and the flushing pipe sized to handle the discharge of bed load. If the flushing pipe invert is below the outlet of the trench, the Engineer should consider steepening the trench invert. If the trench outlet invert is below the flushing pipe invert, the latter should be lowered to the elevation of the trench outlet or below. The deck of the collector box should be located above the design flood level to provide safe access to operate gates. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  14 1. 3. Flushing Pipe The flushing pipe should be designed to provide a high enough velocity to en train bed-load captured by the weir. A velocity of at least 3. 0 m/s should be provided. If possible, the outlet end of the pipe should be located a minimum of 1. 0m above the river bed level to provide energy to keep the outlet area free from accumulation of bed load that could block the pipeline. 1. 3. 7 References on Trench weirs CBIP, (2001): Manual on Planning and Design of Small Hydroelectric Scheme Lauterjung et al (1989): Planning of Intake Structures Freidrich Vieweg and Sohn, Braunswchweig – GermanyIAHR (1993): Hydraulic Structures Design Manual: Sedimentation: Exclusion and Removal of Sediment from Diverted Water. By: Arved J. Raudkivi Publisher: Taylor & Francis, New York. Chow (1959): Open- Channel Hydraulics Publisher: McGraw-Hill Book Company, New York. 1. 4 RESERVOIR, CANAL AND PENSTOCK INTAKES The designs of reservoir, canal and penstock intakes are all based on the same principles. However, there are significant variations depending on whether an intake is a t the forebay reservoir of a run-of-river plant or at storage reservoir with large draw down or is for a power tunnel, etc.Examples of a variety of layouts can be fond in IS 9761 Hydropower Intakes – Criteria for Hydraulic Design or Guidelines for Design of Intakes for Hydropower Plants (ASCE, 1995). The features common to all designs are shown in the following sketch: AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  15 The objectives of good design are: To prevent entry of floating debris. †¢ To avoid formation of air entraining vortices. †¢ To minimize hydraulic losses. †¢ 1. 4. 1 Control of floating debrisTo prevent the entry of debris a trashrack is placed at the entry to the intake. For small hydro plants the trashrack overall size is determined based on an approach velocity of 0. 75 m/s to 1. 0m/s to facilitate manual raking. Trashracks may be designed in panels that can be lowered into p lace in grooves provided in the intake walls or permanently attacked to anchors in the intake face. The trashracks should to sloped at 14 ° from the vertical (4V:1H) to facilitate raking. The spacing between bars is determined as a function of the spacing between turbine runner blades.IS 11388 Recommendations for Design of Trashracks for Intakes should be consulted for information about spacing between trashracks bars, structural design and vibration problems. Also, see Section 2. 2. 1/5 of this Standard. 1. 4. 2 Control of Vortices First of all the direction of approach velocity should be axial with respect the intake if at all possible. If flow approaches at a significant angle (greater than 45o) AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  16 from axial these will be significant risk of vortex problems.In such a situation an experienced hydraulic engineer should be consulted and for important projects hydra ulic model studies may be required. For normal approach flow the submergence can be determined from the following formulae: S = 0. 725VD0. 5 S D V = submergence to the roof of the gate section (m) = diameter of penstock and height of gate (m) = velocity at gate for design flow. (m/s) Where: A recent paper by Raghavan and Ramachandran discusses the merits of various formulae for determining submergence (S). 1. 4. 3 Minimization of Head lossesHead losses are minimized by providing a streamlined transition between the entry section and gate section. Minimum losses will be produced when a streamlined bellmouth intake is used. For a bellmouth intake the transition section is formed with quadrants of ellipses as shown in the following sketch. The bellmouth type intake is preferred when ever the additional costs are economically justified. For smaller, mainly mini hydropower stations, simpler designs are often optimal as the cost of construction of curved concrete surfaces may not be offse t by the value of reduction in head losses.Details on the geometry of both types are given †¢ Bellmouth Intake Geometry Geometries for typical run-of-river intakes are shown below: A gate width to height of 0. 785 (D): 1. 00 (H) with H = D is recommended. This permits some reduction in the cost of gates without a significant sacrifice in hydraulic efficiency. There is a second transition between the gate and penstock, rectangular to circular. For a gate having H = D and W= 0. 785D the flow velocity at the gate will be equal to the velocity in the penstock so no further flow acceleration is produced in this section. A length for this transition of 1. x D should be satisfactory. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  17 The head loss co-efficient for this arrangement in Ki =0. 10 Details for layout of bell mouth transitions connecting to a sloping penstock are given in IS9761. †¢ Simplified layout (Mini-Hydro): For smaller/mini hydro projects intake design can be simplified by forming the transition in plane surfaces as shown below: The head loss for this design (Ki) = 0. 19V2/2g. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  18 . 4. 4. AIR VENT An air vent should be placed downstream of the head gate to facilitate air exchange between atmosphere and the penstock for the following conditions: †¢ Penstock filling when air will be expelled from the penstock as water enters. †¢ Penstock draining when air will enter the penstock to occupy the space previously filled by water. The air vent (pipe) must have an adequate cross section area to effectively handle these exchanges of air. The following design rules are recommended: Air vent area should the greater of the following values Where: (m3/s) AV = 0. 0 Ap or QT AV = 25. 0 (m2) AV = cross-section area of air vent pipe AP = cross-section area of penst ock (m2) QP = turbine rated flow ( ? QT of more than one turbine on the penstock) The air vent should exhaust to a safe location unoccupied by power company employees on the general public. 1. 4. 5 PENSTOCK FILLING A penstock should be filled slowly to avoid excessive and dangerous â€Å"blowback†. The recommended practice is to control filling rate via the head gate. The AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  19 ead gate should not be opened more than 50 mm until the penstock is completely full. (This is sometime referred to as â€Å"cracking† the gate. ) 1. 4. 6 REFERENCES ON PENSTOCK INTAKES: †¢ 1. 4. 7 Indian Standard Cited. IS 9761: Hydropower Intakes – Criteria for Hydraulic Design OTHER REFERENCES †¢ Guidelines for Design of Intakes for Hydroelectric Plants ASCE, New York (1995) †¢ Validating the Design of an Intake Structure : By Narasimham Raghavan and M. K. Ram achandran, HRW – September 2007. †¢ Layman’s Guidebook European Small Hydro Association Brussels, Belgium (June 1998)Available on the internet. †¢ Vortices at Intakes By J. L. Gordon Water Power & Dam Construction April 1970 1. 5. TRASHRACKS AND SAFETY RACKS 1. 5. 1 Trashracks: Trashracks at penstock intakes for small hydro plants should be sloped at 4 V: 1H to facilitate manual raking and the approach velocity to the trashracks limited to 1. 0 m/s or less. Use of rectangular bars is normal practice for SHP’s. Support beams should be alignment with the flow direction to minimize hydraulic losses. Detailed trashrack design should be done in accordance with IS 11388. 1. 5. 2Safety Racks: Safety racks are required at tunnel and inverted siphon entries to prevent animals or people who may have fallen into the canal from being pulled into these submerged water ways. A clear spacing of 200 mm between bars is recommended. Other aspects of design should be in accordance with IS 11388. 1. 5. 3 References on Trashracks IS11388 – â€Å"Recommendations for Design of Trashracks for Intakes†. ASCE (1995) –â€Å"Guidelines for Design of Intakes for Hydroelectric Plants†. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  20 DRAWINGS:AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  21 AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  22 2. HYDRAULIC DESIGN OF WATERWAYS The waterways or water conduction system is the system of canals, aqueducts, tunnels, inverted siphons and pipelines connecting the head works with the forebay tank. This Section provides guidelines and norms for the hydraulic design of these structures. 2. 1 2. 1. 1 CANALS Canals for small hydro plants are typically constructed in masonry or reinforced co ncrete.Several typical cross section designs are shown below: AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  23 Lined canals in earth, if required, should be designed in accordance with Indian Standard: IS 10430. A further division of canal types is based on function: – Feeder canal to connect the head regulator (intake) to the desilter – Power canal to connect the desilter to the Forebay tank. 2. 1. 2 Feeder Canals 2. 1. 2. 1 Feeder canal hydraulic design shall be based on the following criteria: = Turbine flow (QT) + Desilter flushing flow (QF).Design flow (Qd) AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  24 2. 1. 2. 2 Scouring velocity: A sufficiently high velocity must be provided to prevent deposition of sediment within the canal. This (scouring) velocity can be determined from the following formulae: d 9/7 S C = 0. 66 6 / 7 n = 0. 015 q 1 1 ? VS = . R 2 / 3 . S C/ 2 n Where: Sc = Scouring slope d = Target sediment size (m) q = Flow per unit width (Q/W) (m/s/m) R = hydraulic radius (m) Vs = scouring velocity (m/s) n = Manning’s roughness coefficient 2. 1. 2. 3 Optimization:The optimum cross section dimensions, slope and velocity should be determined by economic analysis so as to minimize the total life time costs of capital, O&M and head losses (as capitalized value). The economic parameters for this analysis should be chosen in consultation with the appropriate regional, state or central power authorities these parameters include: – Discount rate (i) – Escalation rate(e) – Plant load factor – Service life in years (n) – Annual O+M for canal (% of capital cost) – Value of energy losses (Rs/kWh). Also see Section 1. 7 of this Standard. The selected design would be based on the highest of Vs or Voptimum. . 1. 2. 4 Freeboard: A freeboard allowance above the steady state design water level is required to contain water safely within the canal in event of power outages or floods. A minimum of 0. 5 m is recommended. 2. 1. 3 Power Canals: Power canal design shall be based on the following criteria a) Design flow = total turbine flow (QT) b) Power canal design should be based on optimization of dimensions, slope and velocity, as explained in the previous section. For mini-hydro plants Q < 2. 0 m3/s optimal geometric design dimensions for Type 1 (masonry construction) can be estimated by assuming a longitudinal slope of 0. 04 and a Manning’s n value of 0. 018. Masonry construction would normally be preferred for canals with widths (W) less than 2. 0 m (flow area = AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  25 2. 0 m2). For larger canals with flow areas greater than 2. 0m2, a Type 3, box culvert design would be preferred – based on economic analysis. c) Fr eeboard: A freeboard allowance above the steady state design level is required to contain water safety within the canal in event of power outages. The waterway in most SHP’s terminates in a Forebay tank.This tank is normally equipped with an escape weir to discharge surplus water or an escape weir is provided near to the forebay tank. For mini-hydro plants a minimum freeboard of 0. 50 m is recommended. The adequacy of the above minimum freeboard should be verified for the following conditions: †¢ Maximum flow in the power canal co-incident with sudden outage of the plant. †¢ Design flow plus margins for leakage losses (+0. 02 to +0. 05 QT) and above rated operation (+ 0. 1QT). †¢ Characteristics of head regulator flow control. The freeboard allowance may be reduced to 0. 5 m after taking these factors into consideration. The maximum water level occurring in the forebay tank can be determined from the weir equation governing flow in the escape weir. 2. 1. 4 Reje ction Surge Designs which do not incorporate downstream escape weirs would be subject to the occurrence of a rejection surge in the canal on sudden turbine shutdown, giving above static water levels at the downstream end, reducing to the static level at the upstream (entry) end of the water way. Methods for evaluating water level changes due to a rejection surge are explained in Section 2. 2. 2 / 7. 0 of this Standard. . 2 AQUEDUCTS Aqueducts are typically required where feeder or power canals pass over a gully or side stream valley. If the length of the aqueduct is relatively short the same channel dimensions as for the canal can be retained and there would be no change in hydraulic design. For longer aqueducts design would be based on economic analysis subject to the proviso that flow remains sub critical with NF ? 0. 8 in the flume sections. The following sketch shows the principal dimension of aqueduct entry and exit transitions and flume section. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design OfSmall Hydro Plants /May 2011  Ã‚  26 The changes in invert elevation across the entry and exit structures can be calculated by Bernouli’s equation as below: †¢ Entry transition – consider cross – section (1) and (2); V2 V2 Z 1 + D + 1 = Z 2 + d + 2 + hL 2g 2g and 2 †¢ b? V ? hL = 0. 10 ? 1 ? ?. 2 ? B ? 2g Z2 can be determined from the above equations, since all geometrical parameters are known. Flume – Sections (2) to (3) The slope of the flume section is determined from Manning’s equation 2 †¢ ? Vn ? ( S ) = ? 2 / 3 ? . A Manning’s n = 0. 018 is suggested for concrete channels. ?R ?Some designers increase this slope by 10% to provide a margin of safety on flow capacity of the flume. Exit transition – consider cross section (3) and (4): V2 V2 Z 3 + d + 3 = Z 4 + D + 4 + hL 2g 2g AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  27 and 2 b? V ? hL = 0. 20 ? 1 ? ?. 3 ? B ? 2g Z4 can be determined from the above equations, since all geometrical parameters are known. The same basic geometry can be adapted for transition between trapezoidal canals sections and rectangular flume section, using mean flow width (B) = A/D. . 3. INVERTED SYPHONS 2. 3. 1 Inverted syphons are used where it is more economical to route the waterway underneath an obstacle. The inverted syphon is made up of the following components: †¢ Entry structure †¢ Syphon barrels †¢ Exit structure †¢ Entry Structure: Hydraulic design of the entry structure is similar to the design of reservoir, canal and penstock intakes. Follow the guidelines given in Section 2. 2. 2/2. of this Standard. †¢ Syphon barrels: The syphon barrel dimensions are normally determined by optimization ? V? ? does not tudies, with the proviso that the Froude Number ? N F = ? gd ? ? ? exceed 0. 8. Invert elevations are determine d by accounting for head losses from entry to exit of the structure using Bernouli’s equation. For reinforced concrete channels a Manning’s â€Å"n† value of 0. 018 is recommended. The head loss coefficients for mitre bends can be determined from USACE HDC 228. 2. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  28 AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  29 Exit structure: The exit structure is designed as a diverging transition to minimize head losses; the design is similar to the outlet transition from flume to canal as discussed in Subsection 2. 2. 2/2 of this Standard. The following sketches show the layout of a typical inverted siphon. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  30 2. 3. 2 Reference on Aqueducts and Inverted Syphons â€Å"Hyd raulic Structures† By C. D. Smith University of Saskatchewan Saskatoon (SK) Canada 2. 4. LOW PRESSURE PIPELINESLow pressure pipelines may be employed as an alternative to pressurized box culverts, aqueducts or inverted syphons. Concrete, plastic and steel pipes are suitable depending on site conditions and economics. Steel pipe is often an attractive alternative in place of concrete aqueducts in the form of pipe bridges, since relatively large diameter pipe possesses significant inherent structural strength. Steel pipe (with stiffening rings, as necessary), concrete and plastic pipe also have significant resistance against external pressure, if buried, and offer alternatives to inverted syphons of reinforced concrete construction.Generally pressurized flow is preferred. The pipe profile should be chosen so that pressure is positive through out. If there is a high point in the line that could trap air on filling an air bleeder valve should be provided. Otherwise, hydraulic desi gn for low pressure pipelines is similar to the requirements for inverted syphons. The choice of type of design; low pressure pipeline land pipeline material), inverted syphon or aqueduct, depends on economic and constructability considerations, in the context of a given SHP. Manning’s â€Å"n† Values for selected Pipe Materials Material Welded Steel Polyethylene (HDPE) Poly Vinyl Chloride (PVC)Asbestos Cement Cast iron Ductile iron Precast concrete pipe Manning’s â€Å"n† 0. 012 0. 009 0. 009 0. 011 0. 014 0. 015 0. 013(2) Note: (1) From Table 5. 4 Layman’s Guide Book – ESHA (2) From Ven T. Chow – Open Channel Hydraulics AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  31 2. 5. TUNNELS 2. 5. 1 Tunnels often provide an appropriate solution for water conveyance in mountainous areas. Tunnels for SHP are generally of two types. †¢ Unlined tunnels †¢ Concrete li ned tunnels On SHP tunnels are usually used as part of the water ways system and not subject to high pressures. . 5. 2 Unlined tunnels: Unlined water tunnels can be used in areas of favourable geology where the following criteria are satisfied: a) Rock mass is adequately water tight. Rock surfaces are sound and not vulnerable to erosion (or erodible zones b) are suitably protected. The static water pressure does not exceed the magnitude of the minor field c) rock stress. Controlled perimeter blasting is recommended in order to minimize over break and produce sound rock surfaces. Additionally, this construction approach tends to produce relatively uniform surfaces and minimizes the hydraulic roughness of the completed tunnel surfaces.Design velocities of 1. 5 to 2. 0 m/s on the mean AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  32 cross section area give optimal cross section design. It is normal practice to provi de a 100mm thick reinforced concrete pavement over leveled and compacted tunnel muck in the invent of the tunnel. IS 4880: Part 3 provides additional guidance on the hydraulic design of tunnels and on the selection of appropriate Manning’s â€Å"n† values. 2. 5. 3 Lined Tunnels Where geological are unfavourable it is often necessary to provide concrete linings for support of rock surfaces.IS4880: Parts 1-7 give comprehensive guidelines on the design of lined tunnels. 2. 5. 4 High Pressure Tunnels Design of high pressure tunnels is not covered in this standard. For high pressure design, if required, the designer should consult an experienced geotechnical engineer or engineering geologist. For the purpose of this standard, high pressure design is defined as tunnels subject to water pressures in excess of 10m relative to the crown of the tunnels. 2. 5. 5 Reference on Tunnels IS Standards: IS 4880 â€Å"Code of Practice for the Design of Tunnels Conveying Water†. Ot her References: Norwegian Hydropower Tunnelling† (Third volume of collected papers) Norwegian Tunneling Society Trondheim, Norway. www. tunnel. no Notably: Development of Unlined Pressure Shafts and Tunnels in Norway, by Einar Broch. 2. 6. CULVERTS AND CROSS-DRAINAGE WORKS Small hydro projects constructed in hilly areas usually include a lengthy power canal routed along a hillside contour. Lateral inflows from streams and gullies intercepted by SHP canals often transport large sediments loads which must be prevented from entering the canal. The first line of defense is the canal upstream ditch which intercepts local lateral runoff.The flow in these chains must be periodically discharged or the drain capacity will be exceeded. Flow from these drains is usually evacuated via culverts passing underneath the canal. These culverts would normally be located where gullies or streams cross the canal alignment. The capacity of canal ditches should be decided taking into consideration t he average distance between culverts. In the rare cases when distance between culverts is excessive, consideration should be given to diverting AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  33 itch flows across the canal in flumes or half round pipes to discharge over the downhill side of the canal at suitable locations. Culverts are usually required where the canal route crosses gullies or streams. Culverts at these points provide for flow separation between lateral inflows and canal inflows and often present the most economical solution for crossing small but steep valley locations. It is recommended that culverts design be based on the following hydrological criteria. †¢ For mini hydro projects, 1 in 10 year flood (Q10) †¢ For small hydro projects, 1 in 25 year flood (Q25)Where it is practical to extract the necessary basin parameters, the procedures given in Section 1. 4 should be applied. Otherwise design flows should be estimated from field measurements of cross section area and longitudinal slope at representative cross section of the gully or side stream. A survivable design approach is further recommended with canal walls strengthened to allow local over topping without damage to the canal integrity when floods exceed the design flood values. Detailed hydraulic design should be based on information from reliable texts or design guidelines – such as: â€Å"Design of Small Bridges and Culverts† Goverdhanlal †¢ †¢ 2. 7 2. 7. 1 â€Å"Engineering and Design – Drainage and Erosion Control†. Engineering Manual EM 1110-3-136 U. S. Army Corps of Engineers (1984) www. usace. army. mil/publications/eng-manuals Manufacturer’s guides, notably: – American Concrete Pipe Association www. concrete-pipe. org – Corrugated Steel Pipe Institute www. cspi. ca Power Canal Surges Power canals that are not provided with escape weirs near their downstream end will be subject to canal surges on rapid load rejections or load additions.The rejection surge will typically cause the downstream water level to rise above static level and may control the design of canal freeboard. For load additions there is a risk that the level will fall to critical at the downstream end and restrict the rate at which load can be taken on by the unit. The following formulae taken from IS 7916: 1992 can be used to estimate the magnitude of canal surges. AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  34 Maximum surge height in a power channel due to load rejection may be calculated from the empirical formulae given below:For abrupt closure hmax = K 2 + 2 Kh For gradual closure within the period required for the first wave to travel twice the length of the channel: K hmax = + V . h / g 2 Where: hmax = maximum surge wave height, K = V2/2g = velocity head, V = mean velocity of flow, and area of cross sec tion h = effective depth = top width †¢ Maximum water level resulting from a rejection surge at the downstream of a canal: Maximum W. L. = Yo + hmax †¢ Minimum water level resulting from by a start up surge at the downstream end of a canal: Minimum W. L. = YS – hmax Where: Yo YS = steady state downstream water level static downstream water level. The maximum water level profile can be approximated by a straight line joining the maximum downstream water level to the reservoir level. 2. 7. 2 Canal Surges on Complex Waterways: For waterway systems comprising several different water conductor types, the above equations are not applicable. In such cases a more detailed type of analysis will be required. The U. S. National Weather Service FLDWAV computer program can be used to solved for the transient flow conditions in such cases (Helwig, 2002). 2. 7. 3 References IS Standards cited:IS 7916: 1992 â€Å"Open Channel – Code of Practiceà ¢â‚¬ . Other References â€Å"Application of FLDWAV(Floodwave) Computer Model to Solve for Power Canal Rejection Wave for Simple and Complex Cases†. P. C. Helwig Canadian Society for Civil Engineering Proceedings, Annual Conference Montreal, Canada (2002). AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  35 3. HYDRAULIC DESIGN OF DESILTERS 3. 1 BACKGROUND Sediment transported in the flow, especially particles of hard materials such as quartz, can be harmful to turbine components.The severity of damage to equipment is a function of several variables, notably: sediment size, sediment hardness, particle shape, sediment concentration and plant head. The control of turbine wear problems due to silt erosion requires a comprehensive design approach in which sediment properties, turbine mechanical and hydraulic design, material selection and features to facilitate equipment maintenance are all considered (Naidu, 200 4). Accordingly the design parameters for desilter design should be made in consultation with the mechanical designers and turbine manufacturer.Where the risk of damage is judged to be high a settling basin (or desilter) should be constructed in the plant waterway to remove particles, greater than a selected target size. 3. 1. 1 Need The first design decision is to determine whether the sediment load in the river of interest is sufficiently high to merit construction of a desilter. There is little guidance available on this topic; however, the following limits are suggested by Naidu (2004): Table 2. 2. 3/1. 0 Concentration Suggested Maximum Allowable Sediment versus Plant Head. Parameter Head Maximum allowable sediment concentrationLow and Medium Head Turbines ? 150 m High Head Turbines > 150 m 200 ppm 150 ppm 3. 1. 2 Removal Size There are also considerable divergences of opinion on the selection of design size for sediment removal. Nozaki (1985) suggests a size range of between 0. 3 mm to 0. 6 mm for plant heads ranging from 100 m to 300 m. Indian practice is to design for a particles size of 0. 20 m regardless of head. Some authors suggest that removal of particles smaller than 0. 20 mm is not practical. The adoption of 0. 20 mm is the design (target) sediment size is recommended for Indian SHP designs.AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  36 3. 1. 3 Types of Desilters There are two basic types of desilters: Continuous flushing type Intermittent flushing type Guidelines for design of both types are given in this section. 3. 2. DESIGN CONSIDERATIONS 3. 2. 1 Data Requirements (Small Hydro Plants) It is recommended that a program of suspended sediment sampling be initiated near the intake site from an early stage during site investigations to ensure that sufficient data is available for design.The sampling program should extend through the entire rainy season and should comprise at least two readings daily. On glacier fed rivers where diurnal flow variations may exist, the schedule of sampling should be adjusted to take this phenomenon into account and the scheduled sampling times be adjusted to coincide with the hour of peak daily flow with another sample taken about twelve hours later. While it is often assumed that sediment load is directly related to flow, this is only true on the average, in a statistical sense.In fact it is quite likely, that the peak sediment event of a year may be associated with a unique upstream event such as a major landslide into the river. Such events often account for a disproportionately large proportion of the annual sediment flow. Therefore, it would also be desirable to design the sediment measurement program to provide more detailed information about such events, basically to increase the sampling frequency to one sample per 1 or 2 hours at these times. A five year long sediment collecting program would be ideal. Less than o ne monsoon season of data is considered unsatisfactory.Some authors suggest that the vertical variation of sediment concentration and variations horizontally across the river be measured. However, on fast flowing rivers inherent turbulence should ensure uniform mixing and sampling at one representative point should be sufficient. The data collected in a sediment sampling program should include: †¢ Mean daily concentration of suspended sediment (average of two readings twelve hours apart) †¢ Water temperature †¢ Flow (from a related flow gauging program) The following additional information can then be derived from collected samples.AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  37 †¢ †¢ †¢ A sediment rating curve (sediment concentration versus flow – where possible) Particle size gradation curve on combined sample Specific gravity of particles. It is also recommended that a pet rographic analysis be carried out to identify the component minerals of the sediment mix. It is likewise recommended that experiments be made on selected ranges of particles sizes to determine settling velocities. A further discussion on the subject of sediment sampling is given in Avery (1989)The characteristics of the sediment on a given river as obtained from a data collection program will assist in selection of appropriate design criteria. 3. 2. 2 Data Requirements (Mini Hydro Plants) On mini hydro projects where resources and time may not be available to undertake a comprehensive sampling program, selection of design parameters will depend to a great extent on engineering judgment, supplemented by observations on site and local information. The following regional formula by Garde and Kothyari (1985) can be used to support engineering decision making. 0. 19 ?P ? 0 Vs = 530. 0 P0. 6. Fe1. . S0. 25 Dd . 10 .? max ? ?P? Where Vs = mean sediment load in (tonnes/km2/year) s = average slope (m/m) Dd = drainage density, as total length of streams divided by catchment area (km/km2) P = mean annual precipitation (cm) Pmax = average precipitation for wettest month (cm) Fe = ground cover factor, as below: 1 Fe = [0. 80 AA + 0. 60 AG + 0. 30 AF + 0. 10 AW ] ? Ai = arable land area AA = grass land area (all in km2) AG AF = forested area AW = waste land area (bare rock) 3. 2. 3 Design Criteria The principle design criteria are: 1. The target size for removal (d): d = 0. 20 mm is recommended 2.Flushing flow: QF = 0. 2 QP is recommended 3. Total (design) flow: QT = QP + QF = 1. 2 QP. Where QP is plant flow capacity in (m3/s). AHEC/MNRE/SHP Standards/ Civil Works – Guidelines For Hydraulic Design Of Small Hydro Plants /May 2011  Ã‚  38 3. 2. 4 Siting The following factors control site selection 1. A site along the water way of appropriate size and relatively level with respect to cross section topography 2. A site high enough above river level to provide adequate head for flushing. For preliminary layout a reference river level corresponding to the mean annual flood and minimum flushing head of 1. 0 m is recommended. In principle a desilting tank can be located anywhere along the water conductor system, upstream of the penstock intake. Sometimes it is convenient to locate the desilting basin at the downstream end of the waterway system where the desilter can also provide the functions of a forebay tank. However, a location as close to the head works is normally preferred, site topography permitting. 3. 3 Hydraulic Design A desilter is made up of the following elements: †¢ Inlet section Settling tank †¢ Outlet section †¢ †¢ Flushing system 3. 3. 1