The placing of a body or a part thereof into a liquid.
A group of methane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.
A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)
The volume of BLOOD passing through the HEART per unit of time. It is usually expressed as liters (volume) per minute so as not to be confused with STROKE VOLUME (volume per beat).
Acidic water usually pH 2.5 to 4.5, which poisons the ecosystem and adversely affects plants, fishes, and mammals. It is caused by industrial pollutants, mainly sulfur oxides and nitrogen oxides, emitted into the atmosphere and returning to earth in the form of acidic rain water.
Any combustible hydrocarbon deposit formed from the remains of prehistoric organisms. Examples are petroleum, coal, and natural gas.
A highly toxic, colorless, nonflammable gas. It is used as a pharmaceutical aid and antioxidant. It is also an environmental air pollutant.
An element that is a member of the chalcogen family. It has an atomic symbol S, atomic number 16, and atomic weight [32.059; 32.076]. It is found in the amino acids cysteine and methionine.
A mixture of smoke and fog polluting the atmosphere. (Dorland, 27th ed)
Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.
The presence of contaminants or pollutant substances in the air (AIR POLLUTANTS) that interfere with human health or welfare, or produce other harmful environmental effects. The substances may include GASES; PARTICULATE MATTER; or volatile ORGANIC CHEMICALS.
The effect of GLOBAL WARMING and the resulting increase in world temperatures. The predicted health effects of such long-term climatic change include increased incidence of respiratory, water-borne, and vector-borne diseases.
Lists of words, usually in alphabetical order, giving information about form, pronunciation, etymology, grammar, and meaning.
A series of hydrocarbons containing both chlorine and fluorine. These have been used as refrigerants, blowing agents, cleaning fluids, solvents, and as fire extinguishing agents. They have been shown to cause stratospheric ozone depletion and have been banned for many uses.
A measure of the total greenhouse gas emissions produced by an individual, organization, event, or product. It is measured in units of equivalent kilograms of CARBON DIOXIDE generated in a given time frame.
The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)
The simplest saturated hydrocarbon. It is a colorless, flammable gas, slightly soluble in water. It is one of the chief constituents of natural gas and is formed in the decomposition of organic matter. (Grant & Hackh's Chemical Dictionary, 5th ed)
The study of natural phenomena by observation, measurement, and experimentation.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.
Devices, manned and unmanned, which are designed to be placed into an orbit about the Earth or into a trajectory to another celestial body. (NASA Thesaurus, 1988)
The environment outside the earth or its atmosphere. The environment may refer to a closed cabin (such as a space shuttle or space station) or to space itself, the moon, or other planets.
A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.
Disciplines concerned with the interrelationships of individuals in a social environment including social organizations and institutions. Includes Sociology and Anthropology.
Any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer). It may result from natural factors such as changes in the sun's intensity, natural processes within the climate system such as changes in ocean circulation, or human activities.
Celestial bodies orbiting around the sun or other stars.
The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A natural fuel formed by partial decomposition of vegetable matter under certain environmental conditions.
A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.
Compressed gases or vapors in a container which, upon release of pressure and expansion through a valve, carry another substance from the container. They are used for cosmetics, household cleaners, and so on. Examples are BUTANES; CARBON DIOXIDE; FLUOROCARBONS; NITROGEN; and PROPANE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Experimental devices used in inhalation studies in which a person or animal is either partially or completely immersed in a chemically controlled atmosphere.
A small aerosol canister used to release a calibrated amount of medication for inhalation.
The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.