Author: workhouse123
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Solar angles
The earth makes one rotation about its axis every 24 h and completes a revolution about the sun in a period of approximately 365.25 days. This revolution is not circular but follows an ellipse with the sun at one of the foci, as shown in Figure 2.3. The eccentricity, e, of the earth’s orbit is very small, equal to…
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Reckoning of time
In solar energy calculations, apparent solar time (AST) must be used to express the time of day. AST is based on the apparent angular motion of the sun across the sky. The time when the sun crosses the meridian of the observer is the local solar noon. It usually does not coincide with the 12:00…
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Other renewable energy systems
This section briefly reviews other renewable energy systems. Most of these, except wind energy, are not covered in this book. More details on these systems can be found in other publications. Wind energy Wind is generated by atmospheric pressure differences, driven by solar power. Of the total of 175,000 TW of solar power reaching the earth,…
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A brief history of solar energy
Solar energy is the oldest energy source ever used. The sun was adored by many ancient civilizations as a powerful god. The first known practical application was in drying for preserving food (Kalogirou, 2004). Probably the oldest large-scale application known to us is the burning of the Roman fleet in the bay of Syracuse by…
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State of the climate
A good source of information on the state of climate in the year 2011 is the report published by the U.S. National Climatic Data Center (NCDC), which summarizes global and regional climate conditions and places them in the context of historical records (Blunden and Arndt, 2012). The parameters examined are global temperature and various gases…
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Energy-related environmental problems
Energy is considered a prime agent in the generation of wealth and a significant factor in economic development. The importance of energy in economic development is recognized universally and historical data verify that there is a strong relationship between the availability of energy and economic activity. Although in the early 1970s, after the oil crisis,…
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Energy demand and renewable energy
Many alternative energy sources can be used instead of fossil fuels. The decision as to what type of energy source should be utilized in each case must be made on the basis of economic, environmental, and safety considerations. Because of the desirable environmental and safety aspects it is widely believed that solar energy should be…
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General introduction to renewable energy technologies
The sun is the only star of our solar system located at its center. The earth and other planets orbit the sun. Energy from the sun in the form of solar radiation supports almost all life on earth via photosynthesis and drives the earth’s climate and weather. About 74% of the sun’s mass is hydrogen,…
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Irrational prescription:
Over use of antibiotics, indiscriminate use of injections, excessiveuse of drugs, use of anabolic steroids for growth and use of tonics and multivitamins formalnutrition are some of irrational practices.Prevention of irrational prescribing: To prevent irrational prescription the following measuresshould be taken-a) making correct diagnosis b) limiting the number of the drugs c) encouragingthe availability of…
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Rational use of drugs:
According WHO rational use of drugs requires that patientsreceive medications appropriate to their clinical needs, in doses that meet their ownrequirements for an adequate period of time, and lowest cost to them and theircommunity.Criteria for rational prescribing: Rationa prescribing should meet the certain criteria such asappropriate diagnosis, indication, drug, patient, dosage, duration, route of administration,information…