Resist contamination

Despite the use of 2.5 million tons of pesticide worldwide, approximately 35% of potential crop production is lost to pests. An additional 20% is lost to pests that attack the food post-harvest. Thus, nearly one-half of all potential world food supply is lost to pests despite human efforts to prevent this loss. Pesticides, in addition to saving about 10% of world food supply, cause serious environmental and public health problems. These problems include human pesticide poisonings fish and bird kills destruction of beneficial natural enemies pesticide resistance contamination of food and water with pesticide residues and inadvertent destruction of some crops. 

PARTICULATE Organic Residual resist Contaminated cleaning reagents or adhesion promoters. Dirty spin coating equipment or drying ovens. Human debris such as dandruff, hair, etc. 

Resistive Thermal Detectors (RTDs) RTDs determine temperature by measuring the change in resistance of an element due to temperature. Platinum is generally utilized in RTDs because it remains mechanically and electrically stable, resists contaminations, and can be highly refined. The useful range of platinum RTDs is... 

Bioremediation using Biodrain is not possible for compounds resistant to biodegradation. Much longer degradation times are required for compounds such as polychlorinated biphenyls (PCBs) and polynuclear aromatics (PNAs) 3 to 7 years may be required for highly resistant contaminants. Bioremediation is also limited by below-freezing temperatures and free aqueous metals concentrations. Metals can be extracted or immobilized prior to biotreatment. Biodrain cannot be installed in rock or some landfill situations unless holes are drilled first. Current installation limits are approximately 40 ft. 

Although atmospheric corrosion of ferrous metals is related first to the amount of moisture in the air (relative humidity), atmospheric moisture alone has no influence on the corrosion of stainless steel. Of primary importance are the effects of such atmospheric contaminants as particulate chlorides and iron-based dust. Sulfur-based acids will promote corrosion while oxides of nitrogen improve the resistance. Contaminants such as hydrocarbons, ammonia, and oxides of carbon have no effect. 

Liquid Photoresist Liquid resists work well in a print-and-etch process. They have excellent adhesion and a tolerance for surface flaws and are relatively low in cost. The disadvantage of a liquid photoresist is the need to produce a perfect coating. Foreign material, skips, thin spots, and dewetting all cause serious image problems. The use of a wet coating can also cause problems due to resist contamination of the transport system. 

The monomers used may present one or more polymerization sites. In the case of one site only, the cured material will be composed of linear chains and remain soluble in common solvents. This may lead to lower mechanical stiffness and lower plasma etching resistance, with the advantage of easy removal from the mold (resist contamination on the mold can be cleaned more easily) or wafer (resist stripping). In the case of more than one polymerization site, the material will consist of a 3D crosslinked network. 

The most informative study to date was published by Brannan and DiUe in 1990 (17). The study involved the use of an unpreserved shampoo and a skin lotion product that were verified using a standard PET closure. The two products were packaged in identical bottles. Their data proved that closures and dispensers vary in their ability to resist contamination. The pump dispenser was the most contamination-resistant delivery system evaluated for lotions. The flip cap dispenser appeared to be the most protective for shampoos. Other studies showed that pump top closures are more protective in preventing... 

The long-term stability of an instrument is primarily related to the ability of a particular design to resist contamination. Manufacturers strive to minimize this effect by a variety of means such that instrument sensitivity will remain relatively constant over periods of days, weeks, or months under the most severe sample introduction loads. There are several means... 

The construction features of a particular reference design in a reference electrode present a tradeoff in the effort to quickly establish and minimize a constant junction potential, while resisting contamination and coating. The user must decide which is most important for a given application. A decrease in the area of the reference junction reduces the rate of contamination, but increases the fractional rate of coating and plugging. A thickening or solidification of the internal fill, the addition of double and triple junctions, and a decrease in the junction porosity slows down... 

Uses Special cleansing cone, with lipid emulsifiers and detergents for resist, contaminants such as oils, tats, resins, waxes, bitumen, etc. 

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