Matted coil

The constant a appears to be a function of the shape and solvation of the molecules. Theoretical calculations predict a to be 0.5 for a matted coil, 1.0 for a randomly linked chain, and 2.0 for a stiff chain. Experimental values vary from 0.53 for polystyrene in butanone to 1.5 for amylose in ethylenediamine. For polymers of molecular weight 100,000 to 1,000,000, the equation is further modified to give... 

Vibrating-conveyor dryers are suitable for free-flowing solids containing mainly surface moisture. Retention is limited by conveying speeds which range from 0.02 to 0.12 m/s. Bed depth rarely exceeds 7 cm, although units are fabricated to carry 30- to 46-cm-deep beds these also employ plate and pipe coils suspended in the bed to provide additional heat-transfer area. Vibrating dryers are not suit le for fibrous materials which mat or for sticky sohds which may ball or adhere to the deck. 

Dust filter of special ceramic-fiber mat with special pressure-wave absorbing coils... 

The main devices used for mosquito protection in households have been mosquito coils, electric mosquito mats, and liquid vaporizers, all of them methods that vaporize insecticides into the air using heating by means of fire or electricity to control the insects. In recent years, new anti-mosquito products have been commercialized such as fan vaporizers, paper strip type emanators, and resin net type emanators which vaporize insecticides without heating. In all of these products pyrethroid insecticides are used as active ingredients because they are superior in what is called knockdown effect, where noxious insects are rapidly paralyzed and cannot bite, and have a high level of safety for humans. 

Guideline specifications for household insecticide products — mosquito coils, vaporizing mats, liquid vaporizers and aerosols, were drafted at a WHO informal consultation, held in Geneva from 3 to 6 February 1998 (6). The draft guidelines have been distributed to ministries of health and national registration authorities for comments and suggestions. 

Biological larvicides have been introduced for malaria and dengue control in many countries. Locally manufactured biological larvicides are available. Personal protection measures have been promoted by control programmes, including the use of insect repellents, mosquito coils, mats and aerosols. Household pesticide use is increasing in India, Indonesia, Sri Lanka and Thailand. 

Personal protection measures to prevent mosquito bites are actively used by householders. In many developed and medium-income countries in the Region, the use of household insecticide products constituted a major component of the total public health use of pesticides. The mosquito coil is used widely, followed by mats, aerosols and liquid vaporizers. The use of mosquito coils has increased every year from 1995 to 1997 China is the major user. Data indicate that the biggest market for household insecticide products is China, where in 1998 more than 10000 million units of household insecticide products were used. 

For mosquito coils and vaporizing mats, the term mosquito repellent should be included on the label. 

An alternative, more specialized procedure for small-scale use involves the use of vaporizing devices in which a high concentration of an insecticide is dispersed on a solid carrier from which during heating (mosquito mats) or burning (smokes or mosquito coils), or sometimes at mom temperature (impregnated plastic strips), an insecticidal vapour is produced. When used in such products PBO acts more as a solvent or evaporation retardant which evens out the rate of volatilization than as a synergist. 

Figure 16.23. Schematic structures of PEO conformation in V2O5 xerogel and their expected electron density projections along the c axis, (a) coil conformation, (b) zigzag conformation forming bilayer. [Adapted, by permission, from Liu Y J, Schindler J L, DeGroot D C, Kannewurf C R, Hirpo W, Kanatzidis M G, Chem. of Mat., 8, No.2, 1996, 525-34.]...

In GC the gaseous mobile phase must be confined in a column, so that a pressure gradient can cause it to flow past the stationary phase and eventually elute the separated bands out the effluent end of the column. This is inherently a ID separation, along the column, from one end to the other. This dimensionality applies even should the column be coiled to fit in a GC oven rather than vertically straight, like Tswett s gravity flow liquid mobile phase column. However, unlike gases, liquids as mobile phases do not always require confinement to move in a desired direction or retain their volume. If they are in contact with porous beds of small particles or fiber mats, surface forces (capillary attraction) can often induce them to flow. Thus it is possible to carry out the LC process on a stationary phase arrayed as a thin surface layer, usually a planar, 2D surface. Examples include the matted cellulose fibers of a sheet of paper, or a thin layer of silica gel or alumina particles on a planar support (e.g., a pane of glass). 

At present, the main devices used for mosquito protection are mosquito coils, electric mosquito mats and liquid vaporizers, but all of these are methods that vaporize insecticides into the air using heating by means of fire or electricity to... 

Metofluthrin, Pyrethroid, Mosquito Control Agent, Mosquito Mats, Mosquito Coils, Paper Emanotros, Fan-Driven Devices, Resin Formulations... 

Uses Matting agent for paints/coatings, esp. coil coatings Features Untreated high efficiency rec. for systems with low level of gloss and sheen... 

Chem. Descrip. Amorphous hydrated silica, org. surf, treatment Uses Matting agent in add-ca zed systems, board and industrial coatings, coil arid can coatings (> 0.75 mil) high solids systems (> 0.75 mil), radiation-cured systems (> 0.75 mil), kyd urea systems, water-based coatings, 2-component polyurethane systems Features High porosity... 

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