Release of chemicals

There are two basic kinds of explosions involving the release of chemical energy ... 

The release of chemical energy during combustion of gases produces a luminous, radiating zone which is seen as the flame or flame front. ... 

Chemical Applications. Courtaulds has developed a series of acryHc-based fibers for controUed release of chemical reagents. The trade name of these fibers is Actipore. The reagents are entrapped within the fiber and slowly released at a rate dependent on the exact porosity of the fiber (102). 

In bulk chemical reactions, an oxidizer (electron acceptor) and fuel (electron donor) react to form products resulting in direct electron transfer and the release or absorption of energy as heat. By special arrangements of reactants in devices called batteries, it is possible to control the rate of reaction and to accomplish the direct release of chemical energy in the form of electricity on demand without intermediate processes. 

Accidental release An unintended or sudden release of chemicals) from manufacturing, processing, handling, or on-site storage facilities to the air, water, or land. 

Public awareness of the release of chemicals into the atmosphere has gone beyond the primary ambient pollutants (e.g., SO2 or O3) and governments require air toxics management plans. One component of this process is the characterization of the air quality via sampling. 

Adequate distance frequently serves to mitigate the consequences of an accidental release of chemicals, e.g. a flammable liquid spillage or toxic gas escape. 

Modeling the Release of Chemicals (predicting the path, the effect, and the area of impact of the chemical release using mathematical analysis)... 

Contains information on industrial location, storage, and release to air, water, and land of SARA Section 313 chemicals. Data is divided into the following categories facility identification, substance identification, environmental release of chemical, waste treatment, and off-site waste transfer. 

Each employer must address what actions employees are to take when there is an unwanted release of highly hazardous chemicals. Emergency preparedness is the employer s third line of defense that will be relied on along with the second line of defense, which is to control the release of chemicals. Control releases and emergency preparedness will take place when the first line of defense to operate and maintain the process and contain the chemicals fails to stop the release. In preparing for an emergency chemical release, employers will need to decide the following ... 

Fog Po.ssiblc cause of plant impact by surface vehicles or aircratc Release of chemicals Plant specific requires detailed stiuJy... 

Risk is often defined as the likelihood of a certain event times a measure of the severity of its consequences. Most risk assessment studies concentrate on estimating the likelihood of certain events. They often concern the release of chemicals, or accidents in engineering projects and the project outcome. In thi.s section, the subject of accidents is not covered. Risk assessment (RA), as a technique, has been adopted by various national governments, by EU, and by OECD.-... 

Figure 17.6.1. Vulnerable zones for atmospheric releases of chemicals X and Y from plant Z.

MTX caused a contraction of vascular smooth muscle and positive inotropic, positive chronotropic and arrhythmogenic effects on cardiac muscle. The effect of MTX was little affected by various receptor blockers, a Na channel blocker or a catecholamine depleting agent. Further, MTX had no effect on the enzymes which were related to Ca movements, such as Na , K -ATPase, cyclic AMP phosphodiesterase, and sarcoplasmic reticulum Ca -ATPase. These results would eliminate the possible involvement of an indirect action elicited by the release of chemical mediators and direct modifications of their receptors, Na channels, or various enzymes as a major mechanism of action of MTX. 

Activation of CXCR4 Induces Release of Chemical Transmitters (Gliotransmitters) from Glial Cells... 

The term allelopathy was coined by Molisch in 1937 Q). Presently, the term generally refers to the detrimental effects of higher plants of one species (the donor) on the germination, growth, or development of plants of another species (the recipient). Allelopathy can be separated from other mechanisms of plant interference because the detrimental effect is exerted through release of chemical inhibitors (allelochemicals) by the donor species. Microbes associated with the higher plants may also play a role in production or release of the inhibitors (2). 

EPCRA Some RCRA TSDFs must submit annual reports to EPA detailing releases of chemicals to air,... 

The primary interaction between RCRA and EPCRA is that some RCRA TSDFs treating hazardous waste are required to submit annual reports to U.S. EPA of their releases of chemicals to air, land, and water.2... 

This paper is a review of methods for estimating releases of chemicals into the environment in the course of extraction of raw materials, manufacturing, use, storage, transportation, and disposal, as well as by accidents or natural processes. It discusses source types, forms of substances released (solids, liquids, and gases), receiving media (air, water, soil), time pattern of release (continuous versus intermittent, cyclic versus random), and geographic patterns of release (point, line, area, and volume sources). 

We first describe human activities that can cause releases of chemicals these are usually of greatest concern to fate models, because they suggest where interventions can be made and environmental concentrations can be reduced. We then classify releases by their form, medium of entry, and spatial and temporal patterns. After briefly noting the most usual quantitative... 

Figure 1. Human activities leading to release of chemicals into the environment. Key A, air W, water GW, groundwater L, land.

The polymer and glass microspheres employed in the pressure-sensitive release of chemicals range in size from 1 pm to 1 mm in diameter. (For comparison, a human hair is typically 80-100 pm in diameter.A scanning electron micrograph illustrating the morphology of the particles appears in color Fig. 14.2.1. ... 

---