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Kaffet började ursprungligen konsumeras för koffeinets effekter, vidare utvecklades kaffet och blev en social dryck. Kaffe spreds runt hela världen och koffeinet användes som tillsatts i energidryck och andra livsmedel. Syftet är att undersöka utvecklingen av koffeinets konsumtionsmönster och sociala roll i kaffe och energidryck. Arbetet är en litteraturstudie baserad på fyra vetenskapliga artiklar som samlats in genom två olika databaser. Urvalet av artiklar skedde med hjälp av förbestämda kriterier. Resultatet visar att koffein i dryck ger njutningsfyllda effekter men även bieffekter finns. Koffeinet har utvecklats som tillsatts i bland annat energidryck samt läsk och konsumtion av energidryck kopplas till problembeteenden. Detta livsmedel konsumeras ibland med alkohol och det finns konsekvenser med denna konsumtion. Kaffet har utvecklats till en social dryck och det går koppla denna dryck samt te till olika livsstilar. I diskussionen påvisas det att kaffe och te har en stors ocial roll i samhället. Energidryck och läskedryck visar sig inte ha någon förankring som en social dryck. Vidare talas det om konsumtionen av kaffe, energidryck, te och läskedryck. Konsumtionen av koffeinhaltiga drycker ökar men huruvida kaffet kommer ha en central roll  bland de sociala dryckerna i framtiden är osäkert. / B-uppsatser

The purpose of the work was to investigate the thermal stratification in solar storage containers. Three domestic thermally stratified hot water storage containers were designed with the main object of improving and stabilizing thermal stratification of the stored water as a means of improving the overall efficiency of solar water heating systems. Testing of the three storage containers was carried out under similar conditions and the results showedthat TYPEI storage container behaves as a three-segment stratified system, TYPEII storage container behaves as a two-segment stratified system with a thermocline occupying approximately half of the height of the storage container, and TYPEIII storage container behaves as a two-segment stratified system with a thermocline occupying two thirds of the height of the storage container. It was found that TYPEI storage container, with a LID equal to 3/1, gave the best results in terms of heat collected, and also had the maximum stratification which is the main goal of this study. The effect of each of three flow rates (0.01 kg/Sm2 , 0.015 kg/sm2 , 0.02 kg/sm2 ) on stratification was studied and it was found that the flow rate of 0.01 kg/Sm2 of collector area gave the better result. A low-cost simulator for studying the performance of solar energy storage containers was designed. The design was based on a relatively inexpensive micro-computer linking into a mains power regulator with an 8-bit digital control system. Meteorological data was used to compute radiation income on any inclined plane and the output to the power regulator is controlled by the computed instantaneJus rate of energy gain from the collector system undergoing simulation. A comparison has been made between some of the experimental and theoretical results for mE I storage container. The theoretical prediction was based on two mathematical IOOdels of Duffie and 2 44 Beckman , and Close • A computer system model has been developed to assist in the design of a solar water heating system.