Carbaryl ratio

Table VIII. Synergistic Ratio for Carbaryl with Piperonyl Butoxide Applied Topically to Insects (46)...

Carbaryl and piperonyl butoxide were administered topically to all species in the ratio of 1 5... 

As it has been discussed previously, for the 2 suns CPC the collected UV radiation is about 75% of the available solar radiation, while a nonconcentrating CPC captures in principle all the available radiation. However, as the aperture area of the 2 suns CPC is twice the aperture of the one sun system, the net result is that it collects 1.5 more energy. In the same way, the 1.5 and 1.75 suns reactors are able to capture 1.4 and 1.25 times more energy than the 1 sun system, respectively. The effect of these differences in the energy accepted by each system can be clearly seen in the degradation of carbaryl (Figure 14), where degradation proceeds faster as the concentration ratio increases. 

Figure 14 Evolution of carbaryl concentration as a function of time in four CPC reactors with 1 (a), 1.5 (b), 1.75 (c), and 2 (d) suns concentration ratio, respectively.

An early investigation using a dose-additive design compared the expected to the actual LD50 of a series of binary combination.s of various pesticides in rats. (Keplingcr and Deichmann, 1967), In the study, the expcctedractual ratio for the carbaryl + malathion combination was 1,82, for the carbaryl -H parathion combination it was 1..68. and for... 

Development time, fecundity, sex ratio, mating compatibilities and competition, diapause, persistence of the carbaryl resistance, and the capability to control spider mite populations under carbaryl sprayed and unsprayed conditions were evaluated. The resistant strain did not differ significantly from the susceptible strains tested In the absence of carbaryl treatment. 

Lee, R.M. and Brindley, W.A. (1974). Synergist ratios, EPN detoxication, lipid and drug-induced changes in carbaryl toxicity in Megachile pacifica. Environ. Entomol. 3, 899-907. 

Dislodgeable Foliar Residues and Dermal Exposure. Dislodgeable foliar residues were determined on days 1,3,7,14,15,16, and 17 after carbaryl had been applied to the strawberry fields at the rate of 2 Ib/A. Results of these analyses are found in Figure 2 and Table VIII. The decline of foliar residues appears to follow first-order kinetics, and carbaryl has a half-life of approximately 4.1 days. The three last sampling dates are identical with the study dates. From these data and exposure rates of corresponding days (Table V), a ratio can be calculated by the following equation ... 

There are, however, several apparent discrepancies. The first is the ratio calculated from literature values dealing with carbaryl exposure to pesticide applicators and fruit thinners in an apple orchard (4) This ratio (about 0.6x10 cm h ) was considerably lower than the range seen in Table IX. The difference may be due to the fact that Maitlen et al. (4) measured total and not dislodgeable foliar residues, thus leading to lower values than those obtained by us and others. 

In contrast, in the cation membrane AFT system, the membrane only allows anodic Na and H to pass through to the cathodic half-cell. With an increase of cathodic NaCl concentration, the movement of Na firom anode to cadiode may become more difficult because of die concentration gradient between the two half-cells. More H" than Na may move into the cathodic half-cell. To regenerate H and keep the optimal pH for the Fenton reaction, some of the Fenton reagent may be consumed. This can result in a decrease of treatment efficiency in the cation membrane AFT system when the NaCl concentration ratio (cathode/anode) is high. The functional stebility of the membrane was also evaluated in this study, and it was found that treatment efficiency for degradation of carbaryl did not change after the membrane was used 100 times. 

Carbaryl is of great importance in pest control in India and in tropical countries. Its selective characterization is important to forensic authorities because in criminal cases this insecticide was used frequently as a poison. A selective detection was described with phenylhydrazine hydrochloride that was mixed with 10% sodium hydroxide solution in (1 1) ratio before spraying the TLC plates. This method is for the detection of carbaryl and its breakdown product 1-naphtol in biological and nonbiological materials (72a) (Table 4). 

Carbaryl — (i) Chemical Designations — Synonyms I-Naphthyl N-Methylcarbamate Sevin Chemical Formula C,2H N02 (ii) Observable Characteristics — Physical State (as normalfy shaped) Solid Color Off-white Odor Weak (ill) Physical and Chemical Properties — Physical State at 15 X and I atm. Solid Molecular Weight Not pertinent Boiling Point at I atm. Not pertinent Freezing Point 288, 142, 415 Critical Temperature Not pertinent Critical Pressure Not pertinent Specific Gravity 1.23 at 20°C (solid) Vapor (Gas) Demity Not pertinent Ratio of Specific Heats of Vapor (Gas) Not... 

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