Coffee Benefits Essay

Several studies comparing moderate coffee drinkers (about 2 cups a day) with light coffee drinkers (less than one cup a day) found that those who drank more coffee were significantly less likely to develop Alzheimer’s disease later in life. [2][3] [edit] Reduced risk of gallstone disease Drinking caffeinated coffee has been correlated with a lower incidence of gallstones and gallbladder disease in both men[4] and women[5] in two studies performed by the Harvard School of Public Health. A lessened risk was not seen in those who drank decaffeinated coffee. [edit] Reduced risk of Parkinson’s disease A study comparing heavy coffee drinkers (3. 5 cups a day) with non-drinkers found that the coffee drinkers were significantly less likely to contract Parkinson’s Disease later in life. [6]. Likewise, a second study found an inverse relationship between the amount of coffee regularly drunk and the likelihood of developing Parkinson’s Disease. [7] [edit] Cognitive performance Many people drink coffee for its ability to increase short term recall and increase IQ[8]. Likewise, in tests of simple reaction time, choice reaction time, incidental verbal memory, and visuospatial reasoning, participants who regularly drank coffee were found to perform better on all tests, with a positive relationship between test scores and the amount of coffee regularly drunk. Elderly participants were found to have the largest effect associated with regular coffee drinking. [9] Another study found that women over the age of 80 performed significantly better on cognitive tests if they had regularly drunk coffee over their lifetimes. [10] [edit] Analgesic enhancement Coffee contains caffeine, which increases the effectiveness of pain killers, especially migraine and headache medications. [11] For this reason, many over-the-counter headache drugs include caffeine in their formula. [edit] Antidiabetic Coffee intake may reduce one’s risk of diabetes mellitus type 2 by up to half. While this was originally noticed in patients who consumed high amounts (7 cups a day), the relationship was later shown to be linear. [12] [edit] Liver disease Coffee can also reduce the incidence of cirrhosis of the liver[13] and has been linked to a reduced risk of hepatocellular carcinoma, a primary liver cancer that usually arises in patients with preexisting cirrhosis. [14] The exact mechanism and the amount of coffee needed to achieve a beneficial effect are as yet unclear. [15] [edit] Cancer Coffee consumption is also correlated to a reduced risk of oral, esophageal, and pharyngeal cancer. [16][17] In ovarian cancer, no benefit was found. [18] In the Nurses Health Study, a modest reduction in breast cancer was observed in postmenopausal women only, which was not confirmed in decaffeinated coffee. [19] [edit] Cardioprotective Coffee reduces the incidence of heart disease, though whether this is simply because it rids the blood of excess lipids or because of its stimulant effect is unknown. [citation needed] [edit] Laxative/diuretic Coffee is also a powerful stimulant for peristalsis and is sometimes considered to prevent constipation; it is also a diuretic. However, coffee can also cause loose bowel movements. Practitioners in alternative medicine often recommend coffee enemas for â€Å"cleansing of the colon† due to its stimulus of peristalsis, although mainstream medicine has not proved any benefits of the practice. [edit] Antioxidant Coffee contains the anticancer compound methylpyridinium. This compound is not present in significant amounts in other food materials. Methylpyridinium is not present in raw coffee beans but is formed during the roasting process from trigonelline, which is common in raw coffee beans. It is present in both caffeinated and decaffeinated coffee, and even in instant coffee. [20] http://ezinearticles. com/? Coffee-and-Its-Antioxidants-Healthier-Than-You-May-Realize&id=1235899 Did you know that coffee is chock full of antioxidants, an anticancer agent? If you’ve always thought coffee is bad for you, think again. Aside from keeping you alert and awake, coffee can also keep you young and fighting cancer. So, continue reading for answers to some frequently asked questions about coffee and its antioxidants. What are antioxidants? Antioxidants are any vitamin or nutrient that can help prevent cancer or damage to the heart and other tissues caused by free radicals. By neutralizing free radicals, they prevent cell degradation. Antioxidant rich foods include blueberries, raspberries, dates, chocolate and, of course, coffee. What type of antioxidants are in coffee? The antioxidants found in coffee are called polyphenols. More specifically, the compound is methylpridinium. The antioxidant isn’t present in raw, green coffee beans, but is actually created during the roasting process. How much coffee is enough? Research has shown that people who drink one to two coffees a day have half the risk of developing liver cancer when compared to people who didn’t drink coffee. Meanwhile, drinking 4 to 6 cups of coffee can reduce your risk for type-2 diabetes by as much as 50 percent. However, despite the reduced risk for these diseases and other cancers, like oral, esophageal, and pharyngeal cancer, doctors don’t recommend you start drinking 10 cups a day. Coffee is still a stimulant and a diuretic and if drunk in excess can cause heart problems, anxiety and possible dangerously elevated blood pressure. Can I get these antioxidants from other sources? The specific antioxidant compound of methylpridinium is only found in substantial amounts in coffee. While other food sources like cranberries, dates and other antioxidant-rich foods contain different types of antioxidants, coffee is the primary source for this particular compound. (For other sources of antioxidants try bananas, dry beans, blueberries, pomegranates, lychees and the other foods listed above.) A recent study also found that the vast majority of North Americans get most of their antioxidants from beverages and, in particular, coffee. The average adult takes in about 1300 milligrams per day through coffee and the next source is tea at a mere 294 milligrams per day. Again, while coffee is one of our highest sources of antioxidants – a great cancer-fighting and prevention agent – coffee drinkers should always practice moderation. A cup or two a day may keep a number of common diseases away, but too much coffee can also cause problems. So balance is always a necessity.

Hydraulic Machines

30 CHAPTER 5 TURBINES 5. 1 Introduction Hydraulic turbines are the machines which use the energy of water and convert it to mechanical energy. The mechanical energy developed by a turbine is used in running an electric generator which is directly coupled to the shaft of the turbine. The electric generator thus develops electric power, which is known as hydro-electric power. 5. 2 Elements of Hydraulic Power Plants Fig. 5. 1 General Layout of a Hydraulic Power Plant 31 Fig. 5. 1 shows a general layout of hydraulic power plant, in which an artificial storage reservoir formed by constructing a dam has been shown. 5. 3General Classification of Turbines Turbines are hydraulic machines that convert energy into rotating mechanical energy which in turn generators to produce electrical energy. Originally developed from the water wheels, hydraulic turbines are the prime mortars of importance in modern water power development. According to their hydraulic action, turbines are broadly divided int o two classes. (1) Impulse Turbine: Impulse turbines are more efficient for high heads. At the inlet to the turbine runner, pressure head can be completely converted into kinetic head in the form of a jet of water issuing from one or more nozzles.The free jet will be at atmospheric pressure before as well as after striking the vanes. The turbines are regulated by nozzles which may be a simple straight flow type or a deflector type. The impulse turbines are commonly represented by Pelton Wheels. Turgo turbine is also an impulse turbine but with different buckets, when compared with pelton. Turgo and cross flow turbines are relatively new developments in this class. The main advantages of these turbines are: †¢ They can be easily adopted to power variation with almost constant efficiency. †¢The penstock overpressure and the runner overspeed control are easier. †¢ The turbine enables an easier maintenance. †¢ Due to the jet the manufacturer of these turbines impose a better solid particle control, conducting, consequently, to a lower abrasion effect. (2) Reaction Turbine: A turbine can be made to rotate under the action of water flowing under pressure through the runner. In such turbines the penstocks, the inlet passage to the runner, passage between the runner vanes, all form a continuous passage for the flow under a pressure which continuously decreases from inlet to outlet.The turbine runner directly converts both kinetic energy as well as the pressure energy into mechanical energy. Reaction turbines are represented in modern practice by two principal types: the Francis turbine where the flow is directed radial to the runner axis and the Propeller type 32 where the flow is axial to the runner axis. Propeller turbines may be fixed blade or adjustable blade types. Kaplan turbine has adjustable blades. The main advantages of these turbines are: †¢ It needs lesser installation space. †¢ It provides a greater net head and a better prot ection against downstream high flood levels. It can have greater runner speed. †¢ It can attain greater efficiencies for high power values. In order to distinguish different turbines, the hydraulically salient features like pressure, head, flow direction and magnitude, speed and power etc. The general classification of hydraulic turbines is illustrated in Fig. 5. 2. Hydraulic Turbines Impulse Turbines Pelton Turgo Reaction Turbines Cross-Flow Fixed -Blade Propeller Kaplan Francis Tubular Deriaz Bulb Fig. 5. 2 General Classification of Turbines 5. 4 Number of Units It is normally cost effective to have a minimum number of units at a given small ydropower installation. Multiple units may, however, be necessary from the operational point of view so that even one unit breaks down or is in the routine maintenance, the power generation can be achieved to a certain extent. The efficiency curves of turbines show that the 33 efficiency of power generation from hydraulic turbines conside rably decreases at low flow ratios or power ratios. In multiple units, it is possible to maintain the higher efficiency even in low flows and the low loads by running a certain number of the units at a time depending upon the available discharge and the load demand.Multiple units thus, make the most effective use of water where the flow as well as the load variations are significant. 5. 5 Limits of Use of Turbine Types The selection of best turbines for any particular small hydropower site depends on the site characteristics, the dominant beings the head and the available flow. There are some limits on the range of these parameters in the selection of turbines. Each turbine type is best suited to a certain range of pressure head and the flow rate. For instance, Pelton wheels operate with low flows discharged under great pressures where as Propeller turbines are effective in high flows under low heads.Francis turbines fall in the medium category covering a wide range of different hea ds and discharges. The common practice of SHP systems is to develop standard unit sizes of equipment that will operate over a range of heads and flows. Either charts or nomographs are used to select appropriate units for site specific application. One such chart showing the head-flow range of normal SHP schemes applicable to each type of turbine is given in Fig5. 3. The graph also indicates the approximate power generation for each combination of the head and the discharge applicable to SHP schemes. Fig. . 3 Head-Flow Ranges for Different Turbines 34 5. 6 Pelton Wheel Pelton wheel is well suited for operating under high heads. A pelton turbine has one or more nozzles discharging jets of water which strike a series of buckets mounted on the periphery of a circular disc. The runner consists of a circular disc with a number of buckets evenly spaced round its periphery. The buckets have a shape of a double semi-ellipsoidal cups. The pelton bucket is designed to deflect the jet back thro ugh 165 ° which is the maximum angle possible without the return jet interfering with the next bucket.Fig. 5. 4 Pelton bucket General arrangement of a pelton wheel is shown in the Fig. 5. 5. For SHP schemes, Pelton wheels are easier to fabricate and are relatively cheaper. The turbines are in general, not subjected to the cavitation effect. The turbines have access to working parts so that the maintenance or repairs can be effected in a shorter time. Fig. 5. 5 General Arrangement of a Pelton Wheel 35 Traditionally, micro hydro pelton wheels were always single jet because of the complexity and the cost of flow control governing of more than one jet.Advantages of multi-jet: -Higher rotational speed -Smaller runner -Less chance of blockage Disadvantages of multi-jet: -Possibility of jet interference on incorrectly designed systems -Complexity of manifolds 5. 7 Francis Turbine Francis turbine is a mixed flow type, in which water enters the runner radially at its outer periphery and le aves axially at its center. Fig. 5. 6 illustrates the Francis turbine. The runner blades are profiled in a complex manner and the casing is scrolled to distribute water around the entire perimeter of the runner.The water from the penstock enters a scroll case which completely surrounds the runner. The purpose of the scroll case is to provide an even distribution of water around the circumference of the turbine runner, maintaining an approximately constant velocity for the water so distributed. The function of guide vane is to regulate the quantity of water supplied to the runner and to direct water on to the runner at an angle appropriate design. A draft tube is a pipe or passage of gradually increasing cross sectional area which connects the runner exit to the tail race. Fig. 5. 6 Francis Turbine 36 . 8 Kaplan Turbine It is an axial flow turbine which is suitable for relatively low heads. From Fig. 5. 7, it will be seen that the main components of Kaplan turbine such as scroll casi ng, guide vanes, and the draft tube are similar to those of a Francis turbine. Fig. 5. 7 5. 9 Kaplan Turbine Specific Speed The specific speed of any turbine is the speed in r. p. m of a turbine geometrically similar to the actual turbine but of such a size that under corresponding conditions it will develop 1 metric horsepower when working under unit head. Ns = NP H5/ 4 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(5. 1) where Ns = specific speedP = power in HP 5. 10 Characteristic Curves The turbines are generally designed to work at particular values of H,Q,P,N and ? o which are known as the designed conditions. It is essential to determine exact behaviour of the turbines under the varying conditions by carrying out tests either on the actual turbines or on their small scale models. The results of these tests are usually graphically represented and the resulting curves are known as characteristic curves. 37 -constant head characteristic curves -constant speed characteristic curves -constan t efficiency characteristic curvesIn order to obtain constant head characteristics curves the tests are performed on the turbine by maintaining a constant head and a constant gate opening and the speed is varied by changing the load on the turbine. A series of values of N are thus obtained and corresponding to each value of N, discharge Q and the output power P are measured. A series of such tests are performed by varying the gate opening, the head being maintained constant at the previous value. From the data of the tests the values of Qu, Pu, nu and ? o are computed for each gate opening. Then with Nu as abscissa the values ofQu, Pu and ? o for each gate opening are plotted. The curves thus obtained for pelton wheel and the reaction turbines for four different gate openings are shown in Fig. 5. 8. Fig. 5. 8 Constant head characteristics for Pelton wheel and reaction turbines 38 5. 11 Cavitation in turbines When the pressure in any part of the turbine reaches the vapour pressure of the flowing water, it boils and small bubbles of vapour form in large numbers. These bubbles are carried along by the flow, and on reaching the high pressure zones these bubbles suddenly collapse as the vapour condenses to liquid again.The alternate formation and collapse of vapour bubbles may cause severe damage to the surface which ultimately fails to fatigue and the surface becomes badly scored and pitted. This phenomenon is known as cavitation. In order to determine whether cavitation will occur in any portion of the turbine, D. Thomas has developed a dimensionless parameter called Thomas'cavitation factor ? which is expressed as ?= Ha ? Hv ? Hs H †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(5. 2) where Ha = atmospheric pressure head Hv = vapour pressure head Hs = suction pressure head For Francis turbines: Critical cavitation factor ? c = 0. 625 (Ns/444)2 †¦Ã¢â‚¬ ¦.. (5. 3) For Propeller turbines: ? c = 0. 28 + [ Example 5. 1 1 Ns 3 ( )] 7. 5 444 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. (5. 4) Est imate the maximum height of straight conical draft tube of a 18000 h. p. Francis turbine running at 150 r. p. m under a net head of 27 m. The turbine is installed at a station where the effective atmospheric pressure is 10. 6 m of water. The draft tube must sink at least 0. 77 m below the tail race. Ns = NP H5/ 4 = 327 39 ?c = 0. 625 (Ns/444)2 = 0. 339 Cavitation factor ? = Ha -Hv -Hs H Ha -Hv = 10. 6 m, H =27 m 0. 339 = 10. 6 -Hs 27 Hs = 1. 45 m Max length of the draft tube = 1. 45 + 0. 7 = 2. 22 m 5. 12 Governing of Turbines All the modern turbines are directly coupled to the electric generators. The generators are always required to run at constant speed irrespective of the variations in the load. This constant speed N of the generator is given by the expression N= 60 f p †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. (5. 5) where f = frequency (usually 50) p = numbers of pairs of poles 5. 13 Water Hammer A gate or valve at the end of the penstock pipe controls the discharge to the turbine. As s oon as this governor regulated gate opening is altered, the pipe flow has to be adjusted to the new magnitude of flow.In doing so, there are rapid pressure oscillations in the pipe, often accompanied by a hammering like sound. Hence this phenomenon is called as water hammer. 5. 14 Jet Speed The velocity of flow of the jet depends upon the total net head H at the base of the nozzle and is given by the nozzle equation: v = C v ? 2gH where the discharge coefficient velocity of the nozzle is taken as 0. 95. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(5. 6) 40 5. 15 Bucket speed V= ? DN 60 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(5. 7) The bucket speed should be half of the jet speed. In practice, losses in the turbine cause the maximum efficiency to occur at slightly less than a half, typically 0. 46. V =0. 6 v 5. 16 Design of Pelton Wheel Runner diameter: Runner diameter can be found out from the rpm equation. D= 38 ? H N †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. (5. 8) where N = runner speed(rpm) H = net head Nozzle diameter: The nozzle diameter is given by the nozzle equation: d = 0. 54 ? Q 0. 5 1 ? 0. 25 H n jet †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. (5. 9) Jet ratio: Jet ratio D/d is a size parameter for the turbine. It has a value in a range of 10 to 24. For the high efficiency Pelton wheel design, the ratio of the runner diameter to the nozzle should be more than 9. Number of buckets: The number of buckets required for the efficient operation of the Pelton turbine is calculated as:N buc = 0. 5 ? D + 15 d †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. (5. 10) In practice, the selection and the detail design of the turbine units are carried out by the manufactures based on the model performances. 41 Example 5. 2 Powerhouse is equipped with a vertical shaft pelton turbine. The generator is provided with 6 pairs of poles. Design discharge is 1. 4 m3/s and net head is 425 m. The turbine will provide 6500 hp. Take coefficient of nozzle as 0. 95. Determine (a) the specific speed (b) velocity of jet (c) jet diameter (d) pitch circle diameter of the wheel (e) number of buckets (a) N= 60 f p = 60 x 50/6 = 500 rpmNs = = NP H5/ 4 500 6500 4255 / 4 = 20. 9 Use single jet pelton turbine (b) velocity of jet v = C v ? 2gH = 0. 95 ? 2Ãâ€"9. 81Ãâ€"425 = 86. 75 m/s (c) jet diameter d = 0. 54 ? = 0. 54 ? Q 0. 5 1 ? 0. 25 H n jet 1. 4 0. 5 425 0. 25 ? = 0. 14 m =14 cm 1 1 42 (d) pitch circle diameter D= 38 ? H N = 1. 57 m (e) Number of buckets N buc = 0. 5 ? N buc = 0. 5 ? D + 15 d 1. 57 + 15 0. 14 = 20. 6 = 21 5. 17 Work done of Pelton Wheel In turbines, the water flows on to the runner, which itself is rotating with a certain speed. The water flows over the runner and leaves the runner at its outlet point.We can speak of absolute velocity of water before it flows in the runner, the relative velocity of water w. r. t the runner and again the absolute velocity of water after it has left the runner. In order to ascertain the relationship between these velocities, the velocity vector diagram prove to be very useful. Fig. 5. 9 shows the velocity triangles at the tips of the bucket of a pelton wheel. At the outlet tip velocity triangles are different depending upon the magnitude of u corresponding to which it is slow, medium or fast runner. Inlet velocity diagram VVri Vai =Vwi 43 Outlet velocity diagram V Vwo ? ? Vfo Vro Vao Fig. 5. 9 Velocity triangles V = bucket velocity Vai = absolute velocity of jet at inlet tip Vai = Cv 2 gH1 Vao = absolute velocity of jet at outlet tip Vri = relative velocity of jet at inlet = Vai-V Vro = relative velocity of jet at outlet = k. Vri Vwi = velocity of whirl at inlet =Vai Vwo = velocity of whirl at outlet = V-VroCos ? Vfo = velocity of flow at outlet Mass/sec m =? Q =? a Vai=? ?/4 d2 Vai †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(5. 11) Workdone on the bucket/sec (power developed by turbine) P = m (Vwi -Vwo) V †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(5. 12)Maximum hydraulic efficiency ? h max = 1 (1 + kCos? ) 2 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(5. 13) The hydraulic efficiency is maximum when the bucket speed is equal to half of the velocity of jet. 44 Example 5. 3 The head available at entrance to the nozzle supplying a pelton wheel is 300 m and the coefficient of velocity for the nozzle is 0. 98. The wheel diameter is 1. 8 m and the nozzle diameter is 125 mm. The buckets deflect the jet through 165 °. Assuming the relative velocity of the jet is reduced by 16%, calculate the theoretical speed in rev per min for the maximum hydraulic efficiency.What is the hydraulic efficiency when running at this speed, and what is the power developed? Deflection angle =165 ° = (180- ? ) ? = 15 ° k = 0. 84 hf hn H'=Vai2/2g H For max hydraulic efficiency V/Vai =0. 5 Vai = Cvv2gH1 = 75 m/s V =Vai/2 = 37. 5 m/s V =? DN/60 N =60V/? D = 398 rpm ?hmax = 1/2 (1+ k Cos ? ) = 90. 55 % mass/sec = m = ? Q = ? ?/4 d2 Vai = 920 kg/sec H1 45 Inlet diagram: V Vri From velocity diagram Vwi = Vai =75 m/s Vri = Vai- V =37. 5 m/s Vwi = Vai Outlet diagram: Vwo = V -Vro Cos ? V = V – k Vri Cos ? Vwo Vro Power = m V ( Vwi -Vwo) = 234600 Watts Vao =7 m/s 46 CHAPTER 6CENTRIFUGAL PUMP 6. 1 Introduction Centrifugal pumps are classified as rotodynamic type of pumps in which dynamic pressure is developed which enables the lifting of liquids from a lower to a higher level. The basic principle on which a centrifugal works is that when a certain mass of liquid is made to rotate by an external force, it is thrown away from the central axis of rotation and a centrifugal head is impressed which enable it to rise to a higher level. Now, if more liquid is constantly made available at the centre of rotation, a continuous supply of liquid at a higher level may be ensured.Since in these pumps the lifting of the liquid is due to centrifugal action, these pumps are called ‘centrifugal pumps'. 6. 2 Advantages of centrifugal pumps over reciprocating pumps The main advantage of a centrifugal pump is that its discharging capacity is very much greater than a reciprocating pump which can handle relatively small quantity of liquid only. A centrifugal pump can be operated at very high speeds without any danger of separation and cavitation . The maintenance cost of a centrifugal pump is low and only periodical check up is sufficient .But for a reciprocating pump the maintenance cost is high because the parts such as valves etc. , may need frequent replacement. 6. 3 Component Parts of a Centrifugal Pump The main component parts of a centrifugal pump are: -impeller -casing -suction pipe -delivery pipe 47 Fig. 6. 1 Component part of a centrifugal pump 6. 4 Workdone by the Impeller The expression of the workdone by the impeller of a centrifugal pump on the liquid flowing through it may be derived in the same way as for a turbine. The liquid enters the impeller at its centre and leaves at its periphery. Fig. 6. shows a portion of the impeller of a centrifugal pump with one vane and the velocity triangles at the inlet and outlet tips of the vane. V is absolute velocity of liquid, u is tangential velocity of th e impeller, Vr is relative velocity of liquid, Vf is velocity of flow of liquid, and Vw is velocity of whirl of the liquid at the entrance to the impeller. Similarly V1,u1,Vr1,Vf1 and Vw1 represent their counterparts at the exit point of the impeller. 48 Fig. 6. 2 Velocity triangles for an impeller vane ? = the impeller vane angle at the entrance ? = the impeller vane angle at the outlet = the angle between the directions of the absolute velocity of entering liquid and the peripheral velocity of the impeller at the entrance ? = the angle between the absolute velocity of leaving liquid and the peripheral velocity of the impeller at the exit point Work done per second by the impeller on the liquid may be written as Work done = W ( Vw1 u1 – Vw u) ————-(6. 1) g where W kg of liquid per second passes through the impeller. Since the liquid enters the impeller radially ? = 90 and hence Vw = 0. Thus equation (6. 1) becomes Work done = W (Vw1u1) —â⠂¬â€Ã¢â‚¬â€Ã¢â‚¬â€-(6. ) g 6. 5 Head of a Pump The head of a centrifugal pump may be expressed in the following two ways: (a) Static head (b) Manometric head (or total head or gross head) 49 Fig. 6. 3 Head on a centrifugal pump (a) Static Head Static head is the vertical distance between the liquid surfaces in the pump and the tank to which the liquid is delivered by the pump. Static head (or lift) Hs = hs + hd where hs = static suction lift hd = static delivery lift †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. (6. 3) 50 (b) Manometric Head Manometric head is the total head that must be produced by the pump to satisfy external requirements.If there are no energy losses in the impeller and the casing of the pump, then the manometric head Hm will be equal to the energy given to the liquid by the V ? 1u1 g impeller, i. e Hm = . But if losses occur in the pump then V ? 1u1 ? losses of head in the pump g †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. (6. 4) Applying Bernoulli’s equation between the points, O at the liqui d surface in the pump and 1 in the suction pipe just at the inlet to the pump (i. e. , at the centre line of the pump), the following expression is obtained if the liquid surface in the sump is taken as datum. 0= p s Vs2 + + hs + h f s ? 2g ps Vs2 ? [ + hs + h fs ] 2g ? †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. (6. 5) where ps is the pressure at point l ; Vs is the velocity of flow in the suction pipe ; hs is the suction lift and hfs is the head loss in the suction pipe which includes the head loss due to friction and the other minor losses. It may however be pointed out that if the pump is situated below the level of the liquid surface in the sump, hs will be negative. Equation (6. 5) indicates that at the inlet to the pump there is always a suction or vacuum pressure developed which will be recorded by the vacuum gauge provided at this point as shown in Fig. . 3. The head expressed by equation (6. 5) is called the suction head of the pump. Also, applying Bernoulli’s equation between points 1 and 2, which is just at the outlet of the impeller and is assumed to be at the same level as point 1, then since the impeller imparts a head equal to (Vw1u1/g) to the liquid the following expression is obtained: p s V s2 V? 1u1 p 2 V12 + + = + + hLi ? 2g g ? 2g †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. (6. 6) where p2 is the pressure and V1 is the absolute velocity of the liquid leaving the impeller and hLi is the loss of head in the impeller. 51 6. Specific Speed of Centrifugal Pumps In order to compare the performance of different pumps, it is necessary to have some term which will be common to all centrifugal pumps. The term used for this purpose is the specific speed. The specific speed of a centrifugal pump is the speed at which the specific pump must run to deliver unit quantity against unit head, the efficiency being the same as the actual pump. Ns = NQ H 3/ 4 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦(6. 7) where Ns= specific speed N = rotational speed(rpm) H = total head 6. 7 Performance of Pumps- Charact eristic CurvesA pump is usually designed for one speed, flow rate and head in actual practice, the operation may be at some other condition of head on flow rate, and for the changed conditions, the behaviour of the pump may be quite different. Therefore, in order to predict the behaviour and performance of a pump under varying conditions, tests are performed and the results of the tests are plotted. The curves thus obtained are known as the characteristic curves of the pump. The following three types of characteristic curves are usually prepared for the centrifugal pumps : a) Main and operating characteristics. (b) Constant efficiency or Muschel curves . (c) Constant head and constant discharge curves. Main and Operating Characteristics In order to obtain the main characteristic curves of a pump it is operated at different speeds. For each speed the rate of flow Q is varied by means of a delivery valve and for the different values of Q the corresponding values of manometric head Hm, shaft H. P. , P , and overall efficiency ? are measured or calculated. The same operation is repeated for different speeds of the pump. Then Q v/s Hm ; Q v/s P and Q v/s ? urves for different speeds are plotted, so that three sets of curves, as shown in Fig. 6. 4 are obtained, which represent the 52 main characteristics of a pump. The main characteristics are useful in indicating the performance of a pump at different speeds. During operation a pump is normally required to run at a constant speed, which is its designed speed, (same as the speed of the driving motor). As such that particular set of main characteristics which corresponds to the designed speed is mostly used in the operations of a pump and is, therefore, known as the operating characteristics.A typical set of such characteristics of a pump is shown in Fig. 6. 5 Fig. 6. 4 Main characteristics of a centrifugal pump Fig. 6. 5 Operating characteristic curves of a centrifugal pump 53 6. 8 Parallel or Series Operation of Pu mps Pumps in series Centrifugal pumps generate a relatively low head delivering a fairly high rate of discharge. Normally a pump with a single impeller can be used to deliver the required discharge against a maximum head of about 100 m. But if the liquid is required to be delivered against a still larger head then it can be done by using two or more pumps in series. Fig. 6. 6 Three stage centrifugal pumpIf the required head is more than that can be provided by one pump, the pumps are connected in series. The same discharge passes through both pumps but the head developed by one pump add the other. The total head developed is obtained by adding together the value of the head of each pump corresponding to the relevant discharge. Pumps in Parallel The multi-stage pumps or the pumps in series as described earlier are employed for delivering a relatively small quantity of liquid against very high heads. However, when a large quantity of liquid is required to be pumped against a relativel y small head, then it may 4 not be possible for a single pump to deliver the required discharge. In such cases two or more pumps are used which are so arranged that each of these pumps working separately lift the liquid from a common sump and deliver it to a common collecting pipe through which it is carried to the required height Fig. 6. 7. Since in this case each of the pumps deliver the liquid against the same head, the arrangement is known as pumps in parallel. If Q1, Q2, Q3†¦.. , Qn are the discharging capacities of n pumps arranged in parallel then the total discharge delivered by these pumps will beQt = (Q1+Q2+Q3+†¦Ã¢â‚¬ ¦+Qn) †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. (6. 8) If the discharging capacity of all the n pumps is same, equal to Q , then the total discharge delivered by these pumps will be Qt = nQ Fig. 6. 7 Two centrifugal pumps arranged in parallel 55 A centrifugal pump, having four stages in parallel, delivers 11m3/min of Example 6. 1 liquid against a head of 24. 7m , the diameter of the impeller being 225mm and the speed 1700 rpm. A pump is to be made up with a number of identical stages in series, of similar constriction to those in the first pump, to run at 1250 rpm, and to deliver 14. 5 m3/min, against a head of 248m.Find the number of stages required for the second pump. 1st Pump 2nd Pump Q = 11m3/min Q = 14. 5m3/min H = 24. 7 m H = 248 m N = 1700 rpm N =1250 rpm D = 225 mm Specific speed N s = NQ H 3/ 4 Q for one pump = 11/4 = 2. 75 m3/min Ns = 1700 2. 75 24. 7 3 / 4 = 254 For 2nd pump, with identical stages in series i. e multi-stage pump, if each stage is similar to those of each stage is similar to those of the first pump. The specific speed of each stage Ns = 254 Ns = 254 = NQ H 3/ 4 1250 14. 5 H 3/ 4 H = 49. 64 m Total head required = 248 m No of stages required = 248/49. 64 = 5 stages 56 CHAPTER 7DIMENSIONAL ANALYSIS, HYDRAULIC SIMILITUDE AND MODEL INVESTIGATION 7. 1 Dimensional Analysis Dimensional analysis is a mathematical method of obtaining the equations, changing units, determining a convenient arrangement of variable of a physical relation. In an equation expressing a physical relationship between quantities, absolute numerical and dimensional equality must exit. In general, all such physical relationships can be reduced to the fundamental quantities of mass M, length L and time T. It is a based on the assumption that the phenomenon can be expressed by a dimensionally homogeneous equation, with certain variable.The dimensional analysis is widely used in research work for developing design criteria and also for conducting model tests. 7. 2 Dimensions and Units All physical quantities are measured by comparison. This comparison is always made with respect to some arbitrarily fixed value for each independent quantity, called dimension(e. g. , length, mass, time, etc. ). Since there is no direct relationship between these dimensions, they are called fundamental dimensions. Some other quantities such as area , volume, velocity, force etc. can not be expressed in terms of fundamental dimensions and thus may be alled derived dimensions. There are two systems for fundamental dimensions namely FLT (i. e force, length, time) and MLT (i. e. , mass, length, time). One common system employed in dimensional analysis is the M,L,T system. Table is a listing of some of the quantities used in fluid flow, together with their symbols and dimensions. 57 Quantity Symbol Dimensional Form Length l L Time t T Mass m M Velocity v L T-1 Acceleration a L T-2 Force F M L T-2 Pressure P M L-1 T-2 Discharge Q L3 T-1 Power P M L2 T-3 W,E M L2 T-2 Density ? M L-3 Dynamic viscosity  µ M L-1 T-1 Kinematic viscosity ? L2 T-1 Surface tension M T-2 Work,energy 7. 3 Methods of Dimensional Analysis The methods of dimensional analysis are: -Buckingham's ? theorem -Ralyeigh's method Buckingham's ? Theorem If there are ‘n' variables in a dimensionally homogeneous equation, and if these variables contain ‘m' fu ndamental dimensions such as (M,L,T) , they may be grouped into (nm) non-dimensional independent ? terms. Mathematically, if a variable x1 depends upon independent variables x2, x3,x4, †¦. ,xn, the functional equation may be written as x1 = f (x2, x3, x4, †¦. , xn) The equation may be written in its general form as 58 f1 ( x1, x2, x3,†¦Ã¢â‚¬ ¦. xn) = C In this equation there are ‘n' variables. If there are ‘m' fundimental dimensions, the according to ? theorem f2 ( ? 1,? 2,? 3,†¦.. , ? n-m ) = C1 e. g Q = f (d,H, µ,? ,g) f1 (Q, d, H,  µ, ? , g) = C n = 6; m = 3; (n-m) = 3 f2 ( ? 1, ? 2, ? 3) = C1 Procedure 1. First of all, write the functional relationship with the given data. 2. Then write the equation in its general form. 3. Choose ‘m' repeating variables and write separate expressions for each term. Every ? term will contain the repeating variables and one of the remaining variables. The repeating variables are written in exponential form . 4.With the help of the principle of dimensional homogeneity, find out the values of the exponents by obtaining simultaneous equations. 5. Substitute the value of these exponents in the ? term. 6. After the ? terms are obtained, write the functional relation in the required form. e. g Q = f ( d, H,  µ, ? , g) f1 (Q, d, H,  µ, ? , g) =C n = 6 , m = 3 , (n-m) = 3 f2 (? 1,? 2,? 3)=C1 Choose ? , g, d as repeating variable, ?1 = ? a1 gb1 dc1 Q ? 2 = ? a2 gb2 d c2 H ? 3 = ? a3 gb3 dc3  µ 59 Selection of Repeating Variable 1. The variables should be such that none of them is dimensionless. 2. No two variables should have the same dimensions. . Independent variables should be as far as possible, be selected as repeating variable. ? > fluid property ? > flow characteristics l > geometric characteristics Example 7. 1 A V-notch weir is a vertical plate with a notch angle ? cut into the top of it and placed across an open channel. The liquid in the channel is backed up and forced to flow through the notch. The discharge Q is some function of the elevation H of upstream liquid surface above the bottom of the notch. In addition it depends upon gravity and upon the velocity of approach Vo to the weir. Determine the form of discharge equation: ?V ? Q = gH 5/2 f ? ,? ? ? gH ? ? ? Q = f (H, g , Vo , ? ) f1 ( Q, H ,g ,Vo, ? ) = C Choose g and H as repeating variables n = 5; n-m =3 ; m=2 ?1 = Ha1 gb1 Q = (L)a1 (LT-2)b1 L3 T-1 ?2 =Ha2 gb2 Vo = (L)a2 (LT-2)b2 LT-1 ?3 = ? (M)o (L)o (T)o = (L)a1 (LT-2)b1 L3 T-1 a1+b1+3 =0 ? a1 = -5/2 -2b1-1 =0 ? b1 = -1/2 ?1 = H-5/2 g-1/2 Q = Q vg H 5/2 (M)o (L)o (T)o = (L)a2 (LT-2)b2 L T-1 a2 = -1/2 60 b2 = -1/2 ?2 =H-1/2 g-1/2 Vo= Vo vgH Q f2 ( gH 5/ 2 Q gH 5/ 2 , Vo ,? gH ) = C1 Vo ,? gH ) Vo ,? gH ) =f( Q = gH 5/2 f ( Example 7. 2 Q = VD 2 f [ Prove that the discharge over a spillway is given by the relation gD H ,] V D where V= velocity of flowD = depth of throat H = Head of water g = Acceleration due to gravity Q= f (V,D,H,G) f1 (Q,V,D,H ,G) = C Choose V and D as repeating variables n = 5, m =2, n-m =3 ?1= Va1 Db1 Q = (LT-1)a1 (L)b1 (L3T-1) ?2 = Va2 Db2 H = (LT-1)a2 (L)b2 (L) ?3 = Va3 Db3 g = (LT-1)a3 (L)b3 (LT-2) M0L0T 0 = (LT-1)a1 (L)b1 (L3T-1) 0 = -a1-1 ; a1 = -1 0 = a1+b1+3 ; b1= -2 ?1 = V -1 D -2 Q 61 ?1 = Q VD2 M0L0T 0 =(LT-1)a2 (L)b2 (L) 0 = -a2 a2+b2+1 =0 ; b2 = -1 ?2 = V0 D-1 H = H/D M0L0T 0 = (LT-1)a3 (L)b3 (LT-2) 0 = -a3-2 ; a3 = -2 0 = a3+b3+1 ; b3 =1 ?3 = V-2 D g gD V = f2 ( gD H , )=0 VD 2 D V Q VD 2 Q , = f( gD H ,) V D Q = VD 2 f ( 7. 4 D H ,) V D HYDRAULIC MODELS Hydraulic models, in general, may be either true models or distorted models. True models have all the significant characteristics of the prototype reproduced to scale (geometrically similar) and satisfy design restrictions (kinematic and dynamic similitude). Model-prototype comparisons have clearly shown that the correspondence of behaviour is often well beyond expected limitations, as has been attested by the successful operation of many s tructures designed from model tests. 7. 5 Hydraulic Similitude To know the complete working and behaviour of the prototype, from its model, there hould be a complete similarity between the prototype and its scale model. This similarity is 62 known as hydraulic similitude. From the subject point of view, the following three types of hydraulic similitude are important. (1) Geometric similitude (2) Kinematic similitude (3) Dynamic similitude GEOMETRIC SIMILITUDE The model and the prototype are identical in shape, but differ only in size. (The ratios of all the corresponding linear dimensions are equal) . Let L = Length of the prototype B = Breadth of the prototype D = Depth of the prototype l,b,d = corresponding values of the model L Linear ratio Lr =Area ratio Ar = ( Volume ratio Vr = ( l = BD = bd L B D )2 = ( )2 = ( )2 l b d L B D ) 3 = ( ) 3 = ( )3 l b d KINEMATIC SIMILITUDE The model and the prototype have identical motions. ( The ratios of the velocities at corresponding points a re equal) Let V1 = velocity of liquid in prototype at point 1 V 2 = velocity of liquid in prototype at point 2 v1,v2 = corresponding values of the model Velocity ratio Vr = V1 V2 = = †¦.. v1 v 2 DYNAMIC SIMILITUDE The model and prototype have identical forces. (The ratios of the corresponding forces acting at corresponding points are equal). F Force ratio Fr = 1 = f1 F2 †¦.. f2 63 7. 6 CLASSIFICATION OF MODELS (1) Undistorted model (2) Distorted model Undistorted model A model which is geometrically similar to the prototype is known as undistorted model. Distorted model Model does not have complete geometric similarity with the prototype, is known as distorted model. 7. 7 Comparison of an Undistorted Model and the Prototype If the model is to be overall similar to the prototype, then all the three similarities (i. e, geometric, kinematic, dynamic ) should exist. But this is not possible in actual practice, as it is difficult to exist two types of similarities simultaneousl y.In general, and undistorted model of a prototype is made keeping in view the geometric similarity only and the remaining similarities are then compared for the scale ratio. 7. 8 Velocity of Water in Prototype for the Given Velocity of an Undistorted Model Consider an undistorted model geometrically similar to a proposed prototype like a weir, dam, spillway etc. Let h = head of water over the model v = velocity of water at a point in the model H,V = corresponding values for the prototype 1/s = scale ratio of the model to the prototype Velocity of water in the model v = Cv v2ghVelocity of water on the corresponding point in the prototype V = Cv v2gH C v 2 gh v = = V C v 2 gH h 1 = H s V = v vs Example 7. 3 The velocity at a point on a spillway model of a dam is 1. 3m/sec for a prototype of model ratio 1:10. What is the velocity at the corresponding point in the prototype? 64 Velocity in the model v = 1. 3 m/s Model ratio, 1/s = 1/10 s = 10 Velocity in the prototype V = v vs V =1. 3 x v10 = 4. 11 m/sec 65 References: 1. Hydraulics and Fluid Mechanics P. N. Modi and S. M. Seth 2. Hydraulics, Fluid Mechanics and Hydraulic Machines R. S. Khurmi 3. Fluid Mechanics Victor L. Streeter

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Do Unions Have Any Kind of Future In Australia - Essay Example This will be the time to forge a global partnership between developing global partnership between developed and developing countries to ensure that employment growth policies are put in place to put an end to the scourge of our times - increasing unemployment, poverty and inequality' - said ICFTU President Sharan Burrow. The major corporations of the world are hopping around the world seeking the lowest cost worker. The ITES has meant that the developed world will lose more employment opportunities to developing countries where wages are cheap and working conditions can be stringent. The west and the rest of the developed world already troubled with rising unemployment will see a worse future. The 'global workforce' if at all one arises will require more such meetings and negotiations to make things happen - for a better tomorrow. The Unions around the world have emphasised on the need for collective bargaining. They are primarily composed of skilled and semi-skilled workers. But membership figures vary widely with the industry in question. The problem has particularly plagued Australia in sectors such as health because a large number of health workers from the commonwealth countries are present in these sectors. But what do unions do Changes in the structure and nature of work The Unions seek changes in the structure of work so that the work is less monotonous and comfortable to the worker. Further the unions make sure that the working conditions are also ideal. Unions form and people flock to join them for many reasons. They feel that their grievances will be redressed by the collective bargaining power of the unions. Some members also enrol for ideological issues such as the socialist cause and the anti-capitalism campaign. The Webbs defines that unions arose when the great bulk of workers had ceased to be independent producers, themselves controlling the processes, and owning the materials and the product of their labour, and had passed into the condition of life-long wage-earners, possessing neither the instruments of production nor the commodity in its finished state (Webbs, 1920: 25). In the 1920's Perlman stated thatTrade unionism, which is essentially pragmatic, struggles constantly, not only against the employers for an enlarged opportunity measured in income, security, and liberty in the shop and industry, but struggles also, whether consciously or unconsciously, actively or merely passively, against the intellectual who would frame its programs and shape its policies (1928: 5). Allan Flander says of Unions that 'The first and over-riding responsibility of all trade unions is to the welfare of their own members. That is their primary commitment; not to a firm, not to an industry, not to the nation. A union collects its members' contributions and demands their loyalty specifically for the purpose of protecting their interests as they see them, not their alleged 'true' or 'best' interests as

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Music in Films Essay Talents are strewn around everywhere in the form of music, acting, editing, singing, etc. Stories and themes are left undiscovered in the slums of India. Who would pick them up and give an artistic touch? Hats off to Danny Boyle, an English director who did it. He took the challenge of making it to the silver screen and ended up with Oscars, the highest authority on movies that acknowledged Slum Dog Millionaire with 8 out of 10 nominations. An 18-year old boy Jamal who was raised in Mumbai slum wins 10 million dollars in a quiz competition which is popularly known as â€Å"Who will be the millionaire. † in Indian television show. As he keeps winning, the doubt â€Å"How an uneducated tea supplier working in a call center could answer all questions correctly? † raises. Was he cheating? An obvious question that arises in the minds of everyone which the movie alone could answer. Just one more question the next day will make him a millionaire. That night, Jamal was taken to police station and was beaten brutally on charges of cheating in the quiz competition. The answer to the question â€Å"How Jamal would know the answers to all the questions? † is the central theme of this movie with which the entire story is built. Usually rich ones with good schoolings have better access to quiz competitions with the probability of winning. But Jamal had no formal education. The vicious streets of Mumbai, the horrific nights, the villainous characters around taking every opportunity to exploit poor children like him are all the lessons Jamal went through in the open and unsafe streets of Mumbai. The insecurity for the poor in the slums and the social weaknesses of the Indian society is brought about by the movie in a thrilling fashion. Thugs turning children blind and making them beggars for their selfish motives is one such example. For every question asked in the competition, Jamal derived answer from his life time experience. In other words, there were events in his life which had some connection to the answers. He uses his intelligence and memory to recollect the events and tries his luck. Of course a bit of luck is also necessary in everything one does. Another way of looking at Jamal is that talents are everywhere in forms suppressed, in royal institutions as well as in the slums. Bringing them up to the surface is what heroism is. While young, Jamal made an awkward choice of jumping into the pool of shit to come out of the toilet and finally making it with Amitabachan (a leading actor in India) for an autograph shows his drive and enthusiasm. Jamal meeting her girl friend Lathika back in Mumbai after a long gap is an ecstatic moment. Girls like Lathika after being grown up are eyed seriously by lewd males. Even Jamal had to ruffle with his brother to get Lathika out of him. Both Jamal and Lathika are safe in the end and their love materializes. Jamal talking to Lathika over phone as a lifeline friend is symbolic of Jamal winning his invaluable prize Lathika before winning his 10 million dollar. The movie is a combination of everything – scores of music, songs, cinematography, editing, etc. A. R. Rehman struck his chord with his rich and varied notes scoring over horror, melody, love and misery. The distinction shown among all these items with originality and inventiveness are something special which won him the Oscar for Original Scores. The choice and combination of music themes applied make the movie prolific. For example â€Å"Ring ring ringa, Ring ring ringa†¦. † is used when prostitutes are shown. â€Å"Jai ho, jai ho† is used when Jamal and Lathika meet or when there is a heroic deed performed. The â€Å"jai ho jai ho aaja aaja jind shamiyane ke tale aaja jariwale nile aasman ke tale jai ho jai ho ratti ratti. † song transcends the barriers of language and reaches out to audience worldwide to enthrall and has yielded him yet another Oscar for song. It is the music that takes the song everywhere. Every time when there is a change of scene, the music is simply astounding. The change of mood is rightly set by the music. The background music of quiz program is not new to the people of India, as the real program on television show was similar to this one. However, the typical music recorded in multiple tracks give thrill and excitement when questions are being rolled out. The song â€Å"I fly like paper, get high like planes If you catch me at the border I got visas in my name If you come around here, I make em all day I get one down in a second if you wait   Ã¢â‚¬  while the train is moving has all the gravity of cheerfulness compassioned with the advent of nature. Music is the language whenever flashbacks have to be short and quick. If the arrival of Taj Mahal has some humorous events in it, the music compensates it with reverence. The background music when the prostitutes are shown in the slums of Mumbai, the humming love music when Jamal meets Lathika after a gap, and the song at the end of the movie which brings winning moments for everyone – for the hero, for the director, for the musician, etc is worth mentioning. Whenever the scenes have the power to move the audience, the music leaves an impression in the minds for an everlasting memory. Titanic Titanic is a movie of all times for its unparalleled mixture of fact and fiction filmed on a massive scale. The grandeur of the ship, the differences shown between the rich and poor in the backdrop of Edwardian influence, the love between Rose and Jack tied together in the heart rendering scores of James Horner, the magnanimous touch of James Cameron as writer, director and editor eventually became the first movie of its kind in Hollywood. The movie is screened for just three hours but it comprises a mammoth research by reaching out to the depth of the Atlantic where the original Titanic sank in 1912, and by building a main production set at Rosarito Beach in Baja California, Mexico. As one of the crew members rightly says in the movie, â€Å"The ship is known for grandeur. † it has everything in it: the restaurants, swimming pool, elevators, grand staircase connecting seven decks, a huge glass dome, and all the luxury items. The gigantic ship has massive propellers to pull it all along. The cost of first class tickets are so high even close to $4000 for some which is equal to the amount of $50000 today. Cameron begins the movie in a striking manner as he uses the latest submergence technology and the grandeur with which it explores the wreck of Titanic. The entire operation under water around Titanic in the rumbles of James Horner is a rare phenomenon to watch. â€Å"She is the largest moving object ever made by the hand of man† as said by a character in the movie, it also felt by the music effect. Brock Lowett, an explorer in the movie is curious to possess the necklace with blue diamond worn by Rose in 1912. He ends up discovering a nude painting of Rose. The 100-year old Rose, watching this incident on television calls Brock Lowett and tells the fact that she is the one in the picture. What rose recollects from her memory is the main story of Titanic. Everyone around Rose including her fiancee Caledon is of typical business people who restrict women. Unable to bear with the economy based love and affection running deep in the hearts of her fiance, Rose decides to commit suicide and runs to edge of Titanic and climbs on the railing. Jack comes at the right time to her rescue and the compassionate words of Jack brought her back to life. Jack boarded the third class in the last minute because of the Jackpot he won. He is only a survivor and is no match to the rich and elegant families of the first class passengers who were made to invite him for a dinner party for rescuing Rose. But Jack is well mannered, clear headed, charming and he feels for others. He has passion for drawing and some of his paintings attract Rose. The movie scripts are written aptly to bring Jack and Rose together after an initial disapproval by Rose when Jack asked her â€Å"Do you really like the guy? † Later it turns out to be good and they had a good understanding. Their togetherness in the ship after they started loving each other is the sweetest moment of the movie. It includes Jack’s mystical touch in painting her nakedness wearing only the Heart of the Ocean, their running around the deck and cargo hold of Titanic in joy, their standing at the edge of the ship on the railing with their hands straitened in excitement singing: â€Å"Every night in my dreams I see you. I feel you That is how I know you go. † †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. † This song has become the magical spell of the movie Titanic all over the world and this still picture of their stance became the trademark of the movie Titanic. The music fastens with the solo violin bringing momentum. After a while, the fatal iceberg strikes the edge of Titanic and in the next couple of hours or so everything goes under water. The serious episode of the movie begins with the gradual inflow of water into the ship sinking it gradually and bringing panic. The entire mechanism of how a gigantic ship would submerge under water is a massive research effort discovered and shot for screening by James Cameron. Rose and Jack face predicaments in the ship when they are in search of each other as the ship is sinking gradually. The thrill, excitement and horror are maintained well. Silence followed by music and vice versa creates impression in these scenes. Jack and Rose reached the edge of Titanic from where they jump off the drowning ship and were in the waters of Atlantic waiting for a survival boat. No boats are in the vicinity. Jack prepared to be in the water leaving Rose on a piece of oak panel that is available. The chilly water frozen in minus degree centigrade would not keep Jack alive for long. Rose cries in emotion â€Å"Jack come back†, â€Å"Jack come back†. â€Å"There is a boat Jack. † The music of the song â€Å"Every night in my dreams, I see you. I feel you, That is how I know you go† in low humming voice hardly leaves anyone without tears in eyes. This is one of the greatest emotional scenes on the screens. As she promised Jack she lives until she becomes old enough. It is not just the James Cameron has given The 20th Century Fox has not just produced a movie that has just won 11 Academy awards but has gifted the world a movie of great proportion that would stand all ages. School of Rock School of Rock reveals the power of music through a group of children aged around 10 from a prep school. The spirited hard rock singer and guitarist Dewy Finn masked as a substitute teacher in a class room could not go fizzled out when the music director Craig Wedren has his full support. The hero Dewey Finn visualizes no way out but to be with the rock that paid him nothing. â€Å"Do you want me to give up my band? † he goes weird while talking to his friend Ned Schneebly when he pressurizes him to pay the share of his room rent. Voted out from the band due to his hyper active stage antics, Dewy has no source of income to pay off anything. He is a lone talent unexplored on the stage, dreaming of a great rock career. All that he needs is â€Å"One little thing, it’s music†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬  and he has challenged his band members who voted him out, â€Å"I’ll set up my own band. We are going to start a revolution. † So the fire is burning within him contributes to the central theme of the movie. He turns a phone call of Mr. Schneebly in his favor and decides to go as a substitute teacher in the name of Schneebly to make some money for his immediate needs. As desired, he gets into the school and there begins a new lease of life when he spots children attending music classes amidst his boring class room sessions comprising mainly of recess. He senses a vibrant rock band in his students that could back him up back on to the stage. His mind worked brilliantly. He worked in that direction shifting musical instruments back and forth to the class room and away. He picked up students and assigned each student an instrument and engaged them in practice. The music of comedy is well underway with Dewy managing his students answering all their questions to comfort them that they are doing a school project. That’s how he tells students instead of telling the truth that he wants to win in the Battle of the Bands. Either ways it is a competition – a competition to disclose talents to the public. His conversations with Ms Mullins, the Principal of the preparatory school and other teachers are full of comedy. The words of Dewy, â€Å"It’s experimental teaching. We were learning in singing songs. † confuses the Principal as there is no such thing. Gradually, Ms. Mullins has a special liking for Dewy as he drags her for tea with his artistic eloquence in praise of her profession and her way of handling things. She is much more impressed by his reverence tinged with fun for her profession and especially when he tells her that she is cool and capable. The movie takes a dramatic turn when Schneebly and his fiance come to know of the fraud when Dewy opens up how the check in the name of Schneebly reached him from the preparatory school. The secrets are let out and the police enters the class room when Dewy is in a parents day meet. He is out of school now. Parents are in despair complaining to the Principal about their children’s studies suffered. Ms. Mullins has a tough time answering all the parents and so shuts the door in anger. The power of music is still alive with the students. They secretly take the school bus and reach Dewy’s place to pull him up for the Battle of the Bands. Dewy never dreamt students would be so taken by the rock. They rushed to the theater. Their turn is about to come. Surprise mounts up as the parents and the principal too rushed to the theater to rescue their children. The school of Rock is finally on the stage in colorful dresses. Zack is amazing with his guitar. Freddy is rollicking with his drums. Lawrence is working mystery with his keyboard. Tonika enchants the audience with her voice. â€Å"Baby we was making straight As, But we was stuck in a dumb daze, Dont take much to memorize your life, I feel like Ive been hypnotized. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. † Dewy goes wild on his power stance, moving, dancing, rolling all over and jumping into the crowd to bring a swashbuckling finish to the song. Their performance is surprising, unbelievable, absolutely stunning. Every parent delights at his or her child for doing great on the stage. The music in the last few minutes of the movie brings a complete change of moods. The parents who rushed in panic are now cool after discovering great talents in their children. The principal runs out of words when people praised her. The power of rock took everyone by surprise. Finally the music wins. School of Rock fails to win the $20,000 prize but the audience shouts, â€Å"School of Rock† â€Å"School of Rock† repeatedly asking for once more. Once again The School of Rock is on the stage with a song once again. Dewy gets a chance to train students in music after school hours. The filmmaker Richard Linklater has directed the movie in accordance with, â€Å"Guitar in hands and rock in our hearts. † References Retrieved March 21, 2009,http://www. mygodwithin. com/2009/02/slum-dog-millionaire-receives-8-oscar. html Retrieved March 21, 2009, http://www. futuremovies. co. uk/review. asp? ID=139 Retrieved March 21, 2009, http://www. hollywoodlot. com/titanic/james-cameron. html

African Slave Trade and West African Underdevelopment

African Slave Trade and West African Underdevelopment This paper looks at whether the Atlantic slave trade contributed to the underdevelopment of West Africa. The paper argues that the issue of African underdevelopment is extremely complex, including many factors, aside from the Atlantic slave trade, that have contributed, and continue to contribute, to the underdevelopment of Africa. The paper begins with a review of the slave trade, in terms of the numbers of people involved in this, and the immediate effects of this trade on local economies. The effects of this trade on importing economies is then reviewed, and it is shown that many importing countries benefited massively from this trade, through increased labour supply and through monetary gains which were then applied to developing industry in the importing countries. The repercussions of this industrial development are then discussed, in terms of its effects on Africa. The paper then moves on to look at the effect of the slave trade on Africa, in terms of the demographic imbalances this caused, and the effects this had on the development of African countries, in terms of social, political and economic development. The paper then moves on to look at the roles, and effects, of the colonial powers on African countries, in terms of exploitation of Africa’s natural resources and the immediate and long-lasting effects this has had on Africa, and the continuing exploitation of Africa, through development loans, for example, which cripple the economies of many African countries, through the massive interest payments required, which leaves little money for investment to develop local industry, or social projects. The paper thus sees African underdevelopment as a holistic problem, involving far more than the slave trade, and having far-reaching implications for future generations of Africans. In addition to looking at the effects of the slave trade on African underdevelopment, the term ‘underdevelopment’ will be discussed in an African context. As will be seen, Rodney (1972) argues, in his book How Europe Underdeveloped Africa, that there is no such thing as ‘underdevelopment’, that underdevelopment is not an absence of development, rather that it can only be understood in the context of comparisons, of ‘more developed’ with ‘less developed’ nations, for example, and that it is best understood in the context of exploitation, as, for Rodney, most currently underdeveloped countries are also the countries that are exploited by others, through capitalist, imperialist or colonialist means (Rodney, 1972; p. 110-112). The paper will conclude that capitalist exploitation of Africa began with the slave trade and continues to the present day and is, as we have see, the major factor that was, and continues to be, responsible for th e comparative underdevelopment of African nations. As we have argued, the slave trade per se did not contribute to the comparative underdevelopment of Africa, rather a complex mixture of exploitation, lack of opportunity, and capitalist interests contributed to the underdevelopment of Africa. It is estimated by Curtin (1969) that 9,566,100 slaves were exported from Africa to the Americas and other parts of the Atlantic basin, from it’s beginning in 1451 to when this trade ended in 1870. Many subsequent researchers have, however, provided evidence which shows that this figure is an under-estimation; for example, Stein (1978) has presented a figure some twenty per cent higher than Curtin’s (1969) estimation and Lovejoy (1982) used new calculations, and new shipping data, to put the figure at some 11,698,000. Whatever the exact figure, however, it is clear that demographically, this trade had a massive impact on West Africa, with Thornton (1980) showing that there are marked differences in economic, demographic, political and social development between slave-depleted areas, slave-importing areas and slave-trading areas. The debate that subsequently surrounded Curtin’s estimation of the number of people involved in the Atlantic slave trade has therefore i nvolved much more than a disagreement about numbers: it rests more, now, on whether the slave trade was actually a contributing factor in the current underdevelopment of West Africa. This paper expands the ideas presented by Curtin (1969), and Thornton (1980), looking at the social, economic and political effects of the slave trade on Africa. Rodney (1972; p9-10) argues very strongly that development is characterised by growth in economic production, equity in the distribution of social product and autonomy in control over social processes, and that, as such, underdevelopment is not a state that can be overcome as ‘backward’ societies move through the same stages of growth as ‘advances’ societies, as, instead, Rodney sees capitalist development and underdevelopment as two sides of the same coin (Legassick, 1976). Rodney argues strongly, throughout his book, for African capability, but argues that deeply rooted, externally imposed structural constraints prevented, and prevents, the further development of African society[1]; for example, he argues that what he terms the ‘determinative power’ of the colonial state was one factor that contributed to the underdevelopment of West Africa, not necessarily, therefore, that it was the slave trade per se that contributed wholly to the underdeve lopment of West Africa; this argument is somewhat supported by Brett (1973), who argues strongly throughout his book that the colonial state presence prevented industrialisation in the East African countries he studied, arguing that resource allocation led to peasant agricultural systems becoming the dominant form of agriculture in these countries, for example. It is interesting, then, that both these authors see colonial rule (i.e., political structure) as being the dominant force shaping underdevelopment in Africa, with Brett (1973) arguing that this was the sole factor important in shaping underdevelopment, and Rodney (1972) arguing that colonial rule was but one factor shaping underdevelopment in Africa, in concert with, for example, the demographic skews caused by the slave trade. As such, as Brett (1973) and Rodney (1972) argue, the presence of a colonial power in Africa prevented the development of political structures which would have been conducive to a coherent and holistic development of an industrialised society in Africa; without a political structure which supported assessments of the international economy, from an African perspective, and without political power with an African interest, Africa was left high and dry, unable to develop on African terms, and left at the mercy of the colonial political power, who made decisions based on their own interests, not decisions that were best, in the short or long term, for Africa. The presence of the colonial power thus, itself, led to the underdevelopment of Africa, politically, which had, and continues to have (as we shall see) massive repercussions for African society, in terms of its economic and social development. This academic argument over the numbers of slaves involved in the slave trade shadows the massive scale of the problem: slaves were preferred to be between the ages of fifteen and thirty five, and more men were taken than women, at a ratio of 2:1, skewing the demographics of the towns and villages from where the slaves were taken (Rodney, 1972). As we have seen, 9,566,100 slaves were exported from Africa to the Americas and other parts of the Atlantic basin, from it’s beginning in 1451 to when this trade ended in 1870. Many subsequent researchers have, however, provided evidence which shows that this figure is an under-estimation; for example, Stein (1978) has presented a figure some twenty per cent higher than Curtin’s (1969) estimation and Lovejoy (1982) used new calculations, and new shipping data, to put the figure at some 11,698,000. Whatever the number of slaves that were exported, however, the slave trade essentially extracted all of the healthy men, of reproductive age from African countries involved in the slave trade: this, essentially, led to a lack of a suitable workforce with which to forge ahead with agricultural, social or technological developments, leading to a lack of internal development within Africa, which, couple with the import of cheap goods in to Africa from industrialising nations (i.e., the colonial powers) led to the death of the African manufacturing industry. This, coupled with the lack of a coherent African political power with a presence, and an influence in the region, led directly to the underdevelopment of African countries. In essence, due to the slave trade and the presence of the colonial power, Africa (African leaders) never had a chance to assess itself and to make decisions as to how to go forward and develop political, economic or social structures that would have led to econo mic success. This alone has contributed to the lag in development of Africa, if, indeed it is a lag, if Africa can ever come out of the underdeveloped state it is in, which is a moot point, and which many argue can never happen. This, in conjunction with the massive exploitation of Africa’s natural resources, such as oil, diamonds, bauxite, copper, by external companies (owned by individuals based within the colonial powers) seeking to make a profit from these resources has, many argue, doomed Africa to perpetual underdevelopment. This, in conjunction with ‘aid’ loans given by the World Bank, for example, which have left the economies of African countries in massive debt, with the interest, alone, crippling the economies of these countries, has, again, left Africa in a situation from which it is difficult to see a recovery, let alone a move towards any form of meaningful economic development. The raping of Africa: it’s people, it’s resources, it’s opportun ities, is therefore something that has been present throughout it’s history and which continues to the present day. Thus, not only did the Atlantic slave trade contribute to the underdevelopment of Africa, through the many routes that have already been discussed, but the colonial presence in Africa which led to the raping of Africa’s natural resources, and the domination of these natural resources by external, foreign, companies, has led directly to underdevelopment. These resources were not available for exploitation by Africans, and so Africans were not able to profit from these resources, and were not able to invest these profits in growing industry or technological developments. As such, many scholars argue, Africa was, by the very fact of the raping of its natural resources, doomed to underdevelopment. This coupled with crippling levels of debt that have been incurred through ‘developmental aid’ loans with unfairly high levels of interest, from previous colonial powers, has led to the continued underdevelopment of many African countries. Current campaigns to ‘drop th e debt’ in many African countries may, it has to be said, have come far too late to have much effect, especially when one considers the other, more deadly, scourge which is altering African demographics today: HIV, which, it is estimated, culls more of the African population in many African countries than was ever taken by the slave trade. This new demographic threat is even more deadly considering that drugs are available to treat the disease caused by this virus, but that the current colonial powers, and the companies that are protected by laws of these colonial powers, do not allow these drugs to be sold at a reasonable cost to Africa, essentially blocking off a route to treatment, and condemning a whole generation of Africans to death, and through this, condemning Africa to decades, if not centuries, of continued underdevelopment. In light of this historic pattern of the raping of Africa, perhaps the question should not be how did the slave trade contribute to Africa’s underdevelopment, but, rather, how did the imported slaves contribute to the rapid development of the host countries. For example, African slaves were used in gold and silver mining in the Americas, and certainly speeded up Europe’s technological development, with, for example, English ports involved in the slave trade, such as Liverpool, growing economically with the importing of slaves, and then this economic growth fuelling development in this region which, ultimately, led to the Industrial Revolution. Other specific examples from an English context include individuals who became wealthy through dealing in the slave trade who then used this money to set up successful firms; the Barclays, for example, used money earned from the slave trade to set up Barclays Bank, and Lloyds coffee house expanded in to Lloyds banking and insuranc e following involvement in the slave trade. James Watt, of steam engine fame, also accepted money from slave traders to fund the development of his steam engine; without the slave trade, therefore, many technological developments in Europe, particularly England, would not have happened, and Europe, the world, would not be so well-developed. Imagine a world without the Industrial Revolution: it would, ironically, perhaps look something like Africa looks today. This simplistic analysis of the effects of the importing of slaves is just that: simplistic, but it shows, in rough terms, how the slave trade contributed to economic development and societal progress in the importing countries. This, then, fuelled the rise, the development, of these societies, at the expense of the exporting countries, fuelling longer and stricter periods of colonial rule in the exporting countries, and causing yet more underdevelopment in these countries. This process, in concert with massive demographic depletions, which left, realistically, no workforce in some regions of West Africa, contributed to the underdevelopment of these societies, economically, socially and politically, as, we have seen, is argued by Brett (1973) and Rodney (1972)[2]. In addition, as many current scholars argue, it was, perhaps is, the inability of African societies to come to terms with the consequences of the slave trade that has also held the development of Africa back in realistic terms. For example, many of the African slaves were actually sold to Europeans by Africans themselves, either African leaders or traders, who often conducted raids to collect (i.e., kidnap) suitable subjects for sale in to slavery. Some of these African slave traders became very rich on the profits of their trade, but, unlike in Europe, as we have seen, these traders did not invest their profits in African society or in technological developments; they simply used the money for personal gain and personal interests. The interests of African slave traders in the slave trade, and their reliance on this trade, was shown to be extremely strong following the discussions to abolish this trade; much of the opposition to abolition was from African slave traders themselves, wh o were worried that they would lose out on a massive source of income. Indeed, many did lose income from the Atlantic slave trade and then turned to internal slave trading as a means of generating income. Thus, the slave trade, whilst lessening in volume, did not cease entirely in many African countries, and continued to contribute to a disruption of local societies and to a lack of holistic development of social, political and economic forces within many African societies, in which the slave traders (often rulers, as we have seen) began to act, to take the role of, the colonial power, forging similar patterns of underdevelopment to those described by Brett (1973) for colonial powers in Africa. In addition, much of the profit from the slave trade made by African slave traders was not invested in infrastructure or social projects, or in planning for development through technological improvements; most of the profits, as we have seen, were invested in arms for warfare or in consumer goods. This flood of consumer goods, produced outside of Africa, in Europe for example, had the effect of destroying the few local industries there were, with the long-term effect of destroying many of the manufacturing industries in Africa and, as such, denying Africans the basic conditions for economic growth. The slave trade did not encourage African societies to enter in to the international economy in a positive way, rather it encouraged Western economic development, through, as we have seen, providing a source of labour and income, and by providing markets for some of the new products that were being produced by the Industrial Revolution. This paper will conclude, therefore, that the Atlantic slave trade did not per se cause underdevelopment in Africa, rather that the slave trade is but one piece of a complicated jigsaw of effects that, as a whole, forced Africa in to underdevelopment. The slave trade did take massive numbers of young males out of Africa, thus causing severe depletions in the African workforce, and meaning that the African population growth was curtailed for many years, through lack of breeding, for example[3]. In addition, the import of a workforce in to Europe caused inflations in the local economies at the importing ports, which had cascade effects on the local areas; the slave trade also meant that many individuals became rich, and were able to fund technological developments, which helped to fuel, in part, the Industrial Revolution, for example. This meant that the colonial powers could govern more effectively and for a more prolonged period; meaning that political and social systems of control w ere not developed internally within the African slave-importing countries, this itself fuelling years of political and social underdevelopment. Thus, many factors, not just the slave trade per se contributed to the underdevelopment of West Africa. A statement such as â€Å"the Atlantic slave trade contributed to the underdevelopment of West Africa† is far too simplistic to describe the whole cascade of effects that were, have been, and continue to be important in the underdevelopment of West Africa. James Baldwin’s statement, â€Å"The past is what makes the present coherent, and the past will remain horribly incoherent for as long as we refuse to assess it honestly† is particularly apt for the current discussion of this issue. Scholars of different persuasions (whites vs. blacks, Marxists vs. non-Marxists etc) all have their own interpretations of this period of African history, but it is the responsibility of all mankind to assess this situation responsibly, to acknowledge the continued underdevelopment of Africa as a global, moral, responsibility of all humankind, and not to distort the past and use it to cause continued repression and underdevelopment of this continent. Recent plans, and recent events, for example, leading to the privatisation of water in many African countries is, for example, nothing more than a repeat of colonialism in Africa, a repeat of the raping of Africa, with foreign firms entering in to African economies and destroying them: water privatisation has been shown, for example, to devastate local economies, through ground-up failures in local businesses who can no longer afford to use water. That this has been allowed to happen is a travesty, an insult to Africa, and to all underdeveloped nations; it is a continuation of the exploitation of Africa, its people and its resources, that began at the time of the inception of the slave trade and which continues until the present day. It should ideally be that governments learn from their mistakes through analysis of historical records, not that these mistakes are hidden and repeated in future. As Brett (1973) and Rodney (1972) argue strongly, however, money talks more than moral resp onsibilities, and capitalism will always have two sides: one side that wins and another that loses, facing underdevelopment and poverty as a consequence of losing this battle. As we have seen, this paper has looked at whether the Atlantic slave trade contributed to the underdevelopment of West Africa. The paper has argued that the issue of African underdevelopment is extremely complex, including many factors, aside from the Atlantic slave trade, that have contributed, and continue to contribute, to the underdevelopment of Africa. The paper began with a review of the slave trade, in terms of the numbers of people involved in this, and the immediate effects of this trade on local economies. The effects of this trade on importing economies was then reviewed, and it was shown that many importing countries benefited massively from this trade, through increased labour supply and through monetary gains which were then applied to developing industry in the importing countries[4]. The repercussions of this industrial development were then discussed, in terms of its effects on Africa, showing that local industry was destroyed as a result of cheap imports of textiles, for example, following the manufacturing of this in England following the Industrial Revolution. The paper then moved on to look at the effect of the slave trade on Africa, in terms of the demographic imbalances this caused, and the effects this had on the development of African countries, in terms of social, political and economic development. It was shown that African economic development was held back directly, due to the lack of a workforce and the decline in population growth in Africa over the period the slave trade was active. The paper then moved on to look at the roles, and effects, of the colonial powers on African countries, in terms of exploitation of Africa’s natural resources and the immediate and long-lasting effects this has had on Africa, and the continuing exploitation of Africa, through development loans, for example, which cripple the economies of many African countries, through the massive interest payments required, which leaves little money for investment to develop local industry, or social projects. The paper thus concludes that African underdevelopment as a holistic problem, involving far more than the slave trade, and having far-reaching implications for future generations of Africans. The future is bleak for Africa, and it should be the responsibility of all mankind to act to improve the chances, the opportunities for, all African children, so that the cycle of underdevelopment is not repeated in future. Whether this will happen, however, is dependent on governments, who are run on capitalist principles, and as history has shown us, capitalist, whilst having its shining glories also has a very dark side, which is, essentially, underdevelopment. As we have seen, in light of this historic pattern of the raping of Africa, perhaps the question should not be how did the slave trade contribute to Africa’s underdevelopment, but, rather, how did the imported slaves contribute to the rapid development of the host countries. African slaves were used in gold and silver mining in the Americas, harvesting gold and silver, which was then used to develop these countries. Slavery also certainly speeded up Europe’s technological development, with, for example, English ports involved in the slave trade, such as Liverpool, growing economically with the importing of slaves, and then this economic growth fuelling development in this region, which, ultimately, led to the Industrial Revolution. The Industrial Revolution led the world in to industrialisation, or rather, those sections of the world which had political, economic and social systems in place to realise the implications of the Industrial Revolution and to jump on board of it before they got left behind and exploited. As we have seen, other specific examples from an English context include individuals who became wealthy through dealing in the slave trade who then used this money to set up successful firms; the Barclays, for example, used money earned from the slave trade to set up Barclays Bank, and Lloyds coffee house expanded in to Lloyds banking and insurance following involvement in the slave trade. James Watt, of steam engine fame, also accepted money from slave traders to fund the development of his steam engine; without the slave trade, therefore, many technological developments in Europe, particularly England, would not have happened, and Europe, the world, would not be so well-developed. Thus, there is a direct line linking the slave trade with industrial development in the industrial world. Imagine a world without the Industrial Revolution: it would, ironically, perhaps look something like Africa looks today. That Africa was not part of this development, despite the fact that Africans he lped fuel this development is a cruelly ironic historical fact. This simplistic analysis of the effects of the importing of slaves is just that: simplistic, but it shows, in rough terms, how the slave trade contributed to economic development and societal progress in the importing countries. This, then, fuelled the rise, the development, of these societies, at the expense of the exporting countries, fuelling longer and stricter periods of colonial rule in the exporting countries, and causing yet more underdevelopment in these countries. This process, in concert with massive demographic depletions, which left, realistically, no workforce in some regions of West Africa, contributed to the underdevelopment of these societies, economically, socially and politically, as, we have seen, is argued by Brett (1973) and Rodney (1972). As we have seen, this paper thus concludes that African underdevelopment is a holistic problem, involving far more than the slave trade, and having far-reaching implications for future generations of Africans[5]. The future is bleak for Africa, and it should be the responsibility of all mankind to act to improve the chances, the opportunities for, all African children, so that the cycle of underdevelopment is not repeated in future. Whether this will happen, however, is dependent on governments, who are run on capitalist principles, and as history has shown us, capitalist, whilst having its shining glories also has a very dark side, which is, essentially, underdevelopment. As we have seen, Rodney argues that there is no such thing as ‘underdevelopment’, that underdevelopment is not an absence of development, rather that it can only be understood in the context of comparisons, of ‘more developed’ with ‘less developed’ nations, for example, and that it is best understood in the context of exploitation, as, for Rodney, most currently underdeveloped countries are also the countries that are exploited by others, through capitalist, imperialist or colonialist means (Rodney, 1972; p. 110-112). Capitalist exploitation of Africa began with the slave trade and continues to the present day and is, as we have see, the major factor that was, and continues to be, responsible for the comparative underdevelopment of African nations. As we have argued, the slave trade per se did not contribute to the comparative underdevelopment of Africa, rather a complex mixture of exploitation, lack of opportunity, and capitalist interests contributed to the underdevelopment of Africa. That this can be allowed to continue in to the present day is a blight on the whole of mankind, on everyone who allows this to happen, and on everyone who stands by whilst it happens. In this day and age, when children of eight years old have mobile phones and laptop computers in the ‘developed’ world, it is a travesty that many Africans are having to pay for their water, that many Africans die of AIDS because drug companies refuse to sell drugs to Africa at a reasonable cost, that the legacy of colonialism is still alive in Africa, causing continued suffering, death and exploitation. Africa, romantic, beautiful Africa, of sunsets and safaris, is more than that: it is a rich country, with strong cultures, the birthplace of mankind, and, as such, it deserves more than continued exploitation. Why should an African child’s life be worth less than an English child’s life? In this day and age this modern form of slavery, i.e., lack of opportunity, is as harmful as previous forms of slavery, if not more harmful, and is little more than a repeat of previous forms of slavery, in terms of condemning Africans to a life of misery whilst, all around, everyone else enjoys the benefits of development. Bibliography Brett, E.A., 1973. Colonialism and underdevelopment in East Africa: the politics of economic change. London: Heinemann Educational Books. Curtin, P.D., 1969. The Atlantic slave trade: a census. Madison: Wisconsin. Henige, D., 1986. Measuring the immeasurable: the Atlantic slave trade, West African population and the Pyrrhonian Critic. The Journal of African History 27(2), pp.295-313. Legassick, M., 1976. Review article: perspectives on African development. Journal of African History 17(3), pp.435-440. Lovejoy, P.E., 1982. The volume of the Atlantic slave trade. The Journal of African History 23(4), pp.473-501. Rodney, W., 1972. How Europe Underdeveloped Africa. London: Bogle-L’Ouverture Publications. Stein, R., 1978. Measuring the French slave trade 1713-1792/3. Journal of African history 19(4), pp.515-521. Thornton, J., 1980. The slave trade in eighteenth century Angola: effects on demographic structures. Canadian Journal of African Studies 14(3), pp.417-427. 1 Footnotes [1] In the same vein, Rodney argues that there is no such thing as ‘underdevelopment’, that underdevelopment is not an absence of development, rather that it can only be understood in the context of comparisons, of ‘more developed’ with ‘less developed’ nations, for example, and that it is best understood in the context of exploitation, as, for Rodney, most currently underdeveloped countries are also the countries that are exploited by others, through capitalist, imperialist or colonialist means (Rodney, 1972; p. 110-112). [2] As has been argued, the slave trade essentially extracted all of the healthy men, of reproductive age from African countries involved in the slave trade: this, essentially, led to a lack of a suitable workforce with which to forge ahead with agricultural, social or technological developments, leading to a lack of internal development within Africa, which, couple with the import of cheap goods in to Africa from industrialising nations (i.e., the colonial powers) led to the death of the African manufacturing industry. This, coupled with the lack of a coherent African political power with a presence, and an influence in the region, led directly to the underdevelopment of African countries. In essence, due to the slave trade and the presence of the colonial power, Africa (African leaders) never had a chance to assess itself and to make decisions as to how to go forward and develop political, economic or social structures that would have led to economic success. [3] Rodney, for example, in his book How Europe Underdeveloped Africa shows that whilst the population of Europe quadrupled over the period when the slave trade was functioning, the population of Africa grew by only twenty per cent. [4] For example, we have seen specific examples from an English context, including individuals who became wealthy through dealing in the slave trade who then used this money to set up successful firms; the Barclays, for example, used money earned from the slave trade to set up Barclays Bank, and Lloyds coffee house expanded in to Lloyds banking and insurance following involvement in the slave trade. We have also seen how James Watt, of steam en