Topics in geothermal powerGeothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 26 countries, while geothermal heating is in use in 70 countries. As of 2019, worldwide geothermal power capacity amounts to 15.4 gigawatts (GW), of which 23.9 percent or 3.68 GW are installed in the United States.
Fossil fuelsA fossil fuel is a hydrocarbon-containing material such as coal, oil, and natural gas, formed naturally in the Earth's crust from the remains of dead plants and animals that is extracted and burned as a fuel. Fossil fuels may be burned to provide heat for use directly (such as for cooking or heating), to power engines (such as internal combustion engines in motor vehicles), or to generate electricity. Some fossil fuels are refined into derivatives such as kerosene, gasoline and propane before burning.
Vehicle emissions controlVehicle emissions control is the study of reducing the emissions produced by motor vehicles, especially internal combustion engines. Emissions of many air pollutants have been shown to have variety of negative effects on public health and the natural environment. Emissions that are principal pollutants of concern include: Hydrocarbons (HC) – A class of burned or partially burned fuel, hydrocarbons are toxins. Hydrocarbons are a major contributor to smog, which can be a major problem in urban areas.
Air conditioningAir conditioning, often abbreviated as A/C (US), AC (US), or air con (UK), is the process of removing heat from an enclosed space to achieve a more comfortable interior environment (sometimes referred to as "comfort cooling") and in some cases also strictly controlling the humidity of internal air. Air conditioning can be achieved using a mechanical air conditioner or alternatively a variety of other methods, including passive cooling or ventilative cooling.
HydrocarbonsIn organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic; their odor is usually faint, and may be similar to that of gasoline or lighter fluid. They occur in a diverse range of molecular structures and phases: they can be gases (such as methane and propane), liquids (such as hexane and benzene), low melting solids (such as paraffin wax and naphthalene) or polymers (such as polyethylene and polystyrene).
CosmeticsCosmetics are constituted mixtures of chemical compounds derived from either natural sources, or synthetically created ones. Cosmetics have various purposes. Those designed for personal care and skin care can be used to cleanse or protect the body or skin. Cosmetics designed to enhance or alter one's appearance (makeup) can be used to conceal blemishes, enhance one's natural features (such as the eyebrows and eyelashes), add color to a person's face, or change the appearance of the face entirely to resemble a different person, creature or object.
Statistical mechanicsIn physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. It does not assume or postulate any natural laws, but explains the macroscopic behavior of nature from the behavior of such ensembles. Sometimes called statistical physics or statistical thermodynamics, its applications include many problems in the fields of physics, biology, chemistry, and neuroscience.
Iranian religionsIranian religions, also known as Persian religions, are, in the context of comparative religion, a grouping of religious movements that originated in the Iranian (Persian) plateau (or Greater Iran). The beliefs, activities, and cultural events of the ancient Iranians in ancient Iran are complex matters. The ancient Iranians made references to a combination of several Aryans and non-Aryan tribes. Aryans, or ancient Iranians, worshiped natural elements such as the sun, sunlight and thunder, but they eventually shifted their attention mostly to a single god, whilst acknowledging others.
Aircraft designThe aircraft design process is a loosely defined method used to balance many competing and demanding requirements to produce an aircraft that is strong, lightweight, economical and can carry an adequate payload while being sufficiently reliable to safely fly for the design life of the aircraft. Similar to, but more exacting than, the usual engineering design process, the technique is highly iterative, involving high-level configuration tradeoffs, a mixture of analysis and testing and the detailed examination of the adequacy of every part of the structure.
Topics in astrophysicsAstrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, Astrophysics "seeks to ascertain the nature of the heavenly bodies, rather than their positions or motions in space–what they are, rather than where they are." Among the subjects studied are the Sun (solar physics), other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background.
