A review. Blowing agents referred to as foaming agents, produce gas and used to generate cells (gas pockets) in polymeric materials and classified as phys. and chem. blowing agents. This article discussed about blowing agents, types of blowing agents and their phys. properties.
2005-03-01·Journal of Exposure Analysis and Environmental Epidemiology
Dislodgeable foliar residues are lognormally distributed for agricultural re-entry studies
作者: Korpalski, Stefan ; Bruce, Eric ; Holden, Larry ; Klonne, Dennis
The Agricultural Reentry Task Force (ARTF) conducted a study to determine if dislodgeable foliar residues (DFR) are either normally or lognormally distributed. This is important because the data are used with worker exposure data, which generally appear to be lognormally distributed, to calculate transfer coefficients that will be used to assess farm worker re-entry exposure. Two chemicals were used for this study. Carbaryl, a moderately water-soluble chemical, was applied to cabbage at a rate of 2.0 lbs active ingredient/acre (lb ai/A), while methomyl, a highly water soluble chemical, was applied to cabbage at a rate of 0.9 lb ai/A. The residues were dislodged following an ARTF standardized procedure of collecting leaf punches and shaking in a solution of 0.01% Aerosol OT 75. A total of 28 samples were analyzed for each chemical. The mean+/-SD residue of the carbaryl samples was higher than that for methomyl (511+/-196 and 170+/-71 mug per sample, respectively). However, several types of statistical analyses of the data indicated that, for both chemicals, the residues are lognormally distributed.
2003·Proceedings - Beltwide Cotton Conferences
Novaluron - a registration and performance update
作者: Weiland, R. Tim ; Whitehead, James
Novaluron is an insect growth regulator in the benzoylphenyl urea class of chem. It was recently registered in the U.S.A. as Pedestal for control of a variety of insect pests on container-grown ornamentals as a Reduced Risk pesticide. U.S.E.P.A. is currently reviewing novaluron after acceptance as an Organophosphate Replacement product for cotton and pome fruit (Diamond). The potato grouping also was recently included. Sales of Diamond on these crops are expected for the 2004 season. Field-tests during 2001 with cotton confirmed earlier results demonstrating activity on whitefly (Bemisia spp.), Lepidoptera (Heliocoverpa virescens, H. flea, and Bucculartrix thurberiella) and Lygus spp. Research continues across the cottonbelt to further define rates and insect spectrum.