Emission intensityLife-cycle greenhouse gas emissions of energy sources An emission intensity (also carbon intensity or C.I.) is the emission rate of a given pollutant relative to the intensity of a specific activity, or an industrial production process; for example grams of carbon dioxide released per megajoule of energy produced, or the ratio of greenhouse gas emissions produced to gross domestic product (GDP).
Vapour pressure of waterThe vapour pressure of water is the pressure exerted by molecules of water vapor in gaseous form (whether pure or in a mixture with other gases such as air). The saturation vapour pressure is the pressure at which water vapour is in thermodynamic equilibrium with its condensed state. At pressures higher than vapour pressure, water would condense, whilst at lower pressures it would evaporate or sublimate. The saturation vapour pressure of water increases with increasing temperature and can be determined with the Clausius–Clapeyron relation.
Landfill gasLandfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Trace amounts of other volatile organic compounds (VOCs) comprise the remainder (
Asphyxiant gasAn asphyxiant gas, also known as a simple asphyxiant, is a nontoxic or minimally toxic gas which reduces or displaces the normal oxygen concentration in breathing air. Breathing of oxygen-depleted air can lead to death by asphyxiation (suffocation). Because asphyxiant gases are relatively inert and odorless, their presence in high concentration may not be noticed, except in the case of carbon dioxide (hypercapnia). Toxic gases, by contrast, cause death by other mechanisms, such as competing with oxygen on the cellular level (e.
Atmospheric tideAtmospheric tides are global-scale periodic oscillations of the atmosphere. In many ways they are analogous to ocean tides. Atmospheric tides can be excited by: The regular day–night cycle in the Sun's heating of the atmosphere (insolation) The gravitational field pull of the Moon Non-linear interactions between tides and planetary waves. Large-scale latent heat release due to deep convection in the tropics.
Differential optical absorption spectroscopyIn atmospheric chemistry, differential optical absorption spectroscopy (DOAS) is used to measure concentrations of trace gases. When combined with basic optical spectrometers such as prisms or diffraction gratings and automated, ground-based observation platforms, it presents a cheap and powerful means for the measurement of trace gas species such as ozone and nitrogen dioxide. Typical setups allow for detection limits corresponding to optical depths of 0.
Fluorinated gasesFluorinated gases (F-gases) are chemical compounds containing fluorine that are gases near room temperature. The most common F-gases are hydrofluorocarbons (HFCs), which contain hydrogen, fluorine, and carbon. They are used in a multitude of applications including commercial refrigeration, industrial refrigeration, air-conditioning systems, heat pump equipment, and as blowing agents for foams, fire extinguishants, aerosol propellants, and solvents. HFC-134a (1,1,1,2-Tetrafluoroethane) has grown to become the most abundant HFC in earth's atmosphere as of year 2015.
Acid gasAcid gas is a particular typology of natural gas or any other gas mixture containing significant quantities of hydrogen sulfide (H2S), carbon dioxide (CO2), or similar acidic gases. A gas is determined to be acidic or not after it is mixed with water. The pH scale ranges from 0 to 14, anything above 7 is basic while anything below 7 is acidic. Water has a neutral pH of 7 so once a gas is mixed with water, if the resulting mixture has a pH of less than 7 that means it is an acidic gas.
Mobile source air pollutionMobile source air pollution includes any air pollution emitted by motor vehicles, airplanes, locomotives, and other engines and equipment that can be moved from one location to another. Many of these pollutants contribute to environmental degradation and have negative effects on human health. To prevent unnecessary damage to human health and the environment, environmental regulatory agencies such as the U.S. Environmental Protection Agency have established policies to minimize air pollution from mobile sources.
Indian astronomyIndian astronomy refers to astronomy practiced in Indian subcontinent. It has a long history stretching from pre-historic to modern times. Some of the earliest roots of Indian astronomy can be dated to the period of Indus Valley civilisation or earlier. Astronomy later developed as a discipline of Vedanga, or one of the "auxiliary disciplines" associated with the study of the Vedas dating 1500 BCE or older. The oldest known text is the Vedanga Jyotisha, dated to 1400–1200 BCE (with the extant form possibly from 700 to 600 BCE).
