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A study has been made of the pyrolysis of different cottons in vacuum, and in dry air, mainly at 418°C and the products have been fractionated and analysed. From a purified cotton cellulose, the main products are a combustible tar and water, but when a flame-retardant is present less tar and more gas and carbonaceous residue (char) are produced. The tar is highly flammable, and is a major factor in the burning of cotton. There is a correlation between the amount of tar formed and the flammability of the cotton. Removal of the impurities from the cotton cellulose leads to the formation of more tar on pyrolysis. The tar is a mixture of organic compounds of which the major component is laevoglucosan. Acids, carbonyl compounds and unsaturated compounds have been found and determined quantitatively. It is concluded that for a treated cotton cellulose material to be flame-resistant the amount of tar formed on pyrolysis must be small.

We have reanalyzed the structure of the gamma T-15 peptide from the minor M gamma chain of human hemoglobin (Hb) F. Amino acid analysis confirmed that the Leu 141 residue was missing from position 9 of this peptide, and liquid secondary ion mass spectrometry indicated that it was replaced, not by methionine (residue mass 131) as previously believed, but by an amino acid of mass 129. By analogy with the recently reported oxidation of the corresponding leucine at position gamma 141 of the unstable Hb Atlanta, it appears that the M gamma chain also results from the oxidation of gamma 141 to hydroxyleucine (residue mass 129). The finding that the proportion of the M gamma chain increased when red cell lysates were prepared with carbon tetrachloride prompted us to reinvestigate the oxidation mechanism involved in the formation of beta 141 hydroxyleucine in Hb Atlanta. Oxidation of the beta 141 residue could be detected when carbon tetrachloride was used in the lysis protocol, while conversion of oxyhemoglobin to carbon monoxyhemoglobin prior to carbon tetrachloride treatment prevented oxidation. It therefore appears that the hydroxylation of Leu 141 is not an in vivo process in the circulating red cell. Perhaps leucine at position 141 of the beta, gamma, and delta chains (and at position 136 of the alpha chain), which forms a contact with heme and is located directly across the heme plate from the E helix, is oxidized to hydroxyleucine at a very low rate forming minute amounts of modified chains; this process is accelerated by treatment with agents such as carbon tetrachloride and prolonged exposure to air.

The recent report of the oxidation of beta 141 Leu in a New Zealand family with Hb Atlanta [ beta 75(E19)Leu--Pro] prompted us to reinvestigate the original Hb Atlanta case from Georgia. Tryptic peptide maps showed that the modified beta CoT-14 peptide was present together with beta AT-14 in isopropanol precipitates of Hb Atlanta. Amino acid analysis confirmed that beta CoT-14 lacked leucine and mass spectrometry indicated that it had an increased mass of 16 Daltons. These findings support the proposition that the beta 75 Leu--Pro substitution in the E helix is the direct cause of the beta 141 Leu oxidation.

Transient measurements of the source-drain current ISD of amorphous silicon (a-Si:H) thin film transistors are compared with the results of two dimensional simulations. In particular, we have investigated the effect of different amorphous silicon layer thicknesses on the transient response. It is found that the dynamic response of a transistor with 0.4 μm a-Si:H is significantly slower than that of a device with only 0.06 μm of a-Si:H.

We have developed a numerical simulation program (MANIFEST) which calculates the time-dependent behaviour of one and two dimensional amorphous silicon devices. Our model solves the complete set of transport equations for both electrons and holes and fully includes the appropriate time dependent occupation functions for the traps in the band gap of the amorphous silicon. These traps are assumed to obey Shockiey-Read-Hall kinetics. We have simulated the transient behaviour of pin and nin diodes, both in the dark and under illumination, as well as the characteristics of thin film transistors. Our initial results are in good agreement with experimental data.

In this paper we present results of two-dimensional numerical simulations of both amorphous silicon and NMOS and PMOS polycrystalline silicon thin-film transistors. Both types of devices are modeled using an effective medium approach whereby the defects and grain boundaries in the material are treated as a spatially uniform density of localized states in the band gap. The field-effect mobility is self-consistently calculated from the appropriate band mobility and using one set of parameters for each material we obtain very good agreement between simulations of both output and transfer characteristics and experimental data. The experimental activation energy of the source-drain current for the polycrystalline devices is also found to be in excellent agreement with the numerical simulations.

Aqueous emulsions of 21 insect growth regulators were tested for juvenile hormone activity against 1st-molt Aonidiella aurantii (Maskell) by spraying emulsions on the scale insects while these fed on lemon fruit. Residues of the 1st 6 available compounds were tested by spraying emulsions of these on lemon fruit and introducing crawlers onto the fruit 10 h later. These same compounds used to develop a method of testing by exposing white cap, 1st molt, 2nd molt, and adult stages of scales to their activity. Of these, mixed stereoisomers of methyl 10, ll-epoxy-7-ethyl-3,4-dimethyl-2,6-tridecadienoate and 6, 7-epoxy-3,7-dimethyl-l-[3,4-(methylenedioxy)phenoxy]-2-nonene were the most active (inhibited adult eclosion and prevented embryogenesis) at concentrations of 0.1 and 1.0%. The latter compound also inhibited adult eclosion of progeny from female treated with these concentrations 5 days after mating and suppressed the production of sex pheromone in virgin females treated in the 2nd molt with concentrations of 0.2 or 0.5%. Males were 16 times more susceptible to the activity of methoprene than females.

An investigation of thermomigration in interstitial solid solutions of carbon in β-Ti, V, α-Fe, Co, Ni, and Pd has been carried out using a radioactive tracer technique. A substantial solute redistribution occurred towards the hotter regions in α-iron and vanadium and towards the colder regions in palladium whilst for Co, Ni and β-Ti very little segregation was observed. The measured heats of transport were (in kcal per g-atom): α-Fe, −14.1±1.5; V, −4.9±1.0; Pd, +8.4±1.5; Co, +1.5±1.5; Ni, −1.6±1.4; β-Ti, −1.0±1.0. An examination of the results obtained together with all of the published data for interstitial solute thermomigration suggests that electronic effects could be of major importance in determining the redistributions observed.

Fourteen systemic insecticides were tested against female Panonychus citri (McGregor) by applying 0.4 g active ingredient to the soil around potted nonbearing seedling orange plants. When mites were confined at intervals to detached leaves placed in Tashiro leaf cages, disulfoton, phorate, aldicarb, and schradan consistently caused mortality greater than 80% for 68, 45, 28, and 28 weeks, respectively. However, disulfoton and phorate did not reach their maximum effectiveness until the 4th week posttreatment. The other insecticides ranged from nontoxic to highly toxic for 9-24 weeks. Seven of the insecticides caused phytotoxicity, and yellow spotting was severe when aldicarb and dimethoate were used. Propoxur caused burning of leaf edges and dry spotting.

Endrin, isodrin, dieldrin, heptachlor, and aldrin were the most promising of 27 wettable-power or emulsifiable insecticides screened in the laboratory as soil toxicants against the Mexican fruit fly ( Anastrepha ludens (Loew)). Granulated aldrin appeared to have higher initial toxicity than similar formulations of endrin, dieldrin, or heptachlor in laboratory tests, but the latter were more effective after 294 days. Endrin emulsifiable and wettable-powder formulations were still highly toxic 1,134 days after application to small field plots during the dry season but less effective when the applications were made during the rainy season. A dieldrin emulsifiable formulation at the rate of 12.1 pounds per acre was the best treatment 1,037 days after application in a second series of field tests. However, 5 pounds in either emulsifiable or granulated formulations was not an adequate dosage. Heptachlor gave good initial kill in all tests but its efficiency declined rapidly within 6 months. The toxicants appeared to be more effective on loamy sand than on sandy loam but the amount of spray per acre did not affect performance.

This paper presents the results of an experimental and theoretical investigation of carrier transport and interface state kinetics at grain boundaries in silicon. The grain-boundary interface has been modelled numerically using finite-element methods, and measurements of transient capacitance together with current-voltage characteristics have been recorded over a temperature range from 100K to 300K. Among our findings is that thermionic-field emission from grain-boundary interface states, which has been ignored in earlier treatments, can play a dominant role in transport phenomena for NV \geq 10^{16} cm-3V at T = 300K, or NV \geq 10^{15} cm--3V at 130K, where N is the bulk silicon doping concentration, and V is the voltage applied across the grain boundary.

By simulating the growth morphology of plasma-deposited amorphous silicon films on patterned substrates using a Monte-Carlo technique, we find the effective sticking coefficient for the dominating mass transporting species to be quite different depending on the film growth mechanism. The physical-vapor-deposition-like growth regime producing defective materials is associated with species like SiH2 and SiH which have a large effective sticking coefficient, while the chemical-vapor-deposition-like process producing “device quality” materials is linked to species like SiH3 which has a much smaller effective sticking coefficient. In a triode reactor the physical-vapor-deposition-like process is suppressed since species with small effective sticking coefficients are selected. However, the growth rate decreases rapidly as the substrates are moved away from the plasma. There seems to be an incompatibility between good material quality and fast growth rate in the plasma deposition of amorphous silicon in either diode or triode reactors.

An economical chemical method of separating virgin female California red scale, Aonidiella aurantii (Maskell), from male scale on green lemons was developed. The aqueous formulation used as a dip is dichlorvos 0.5% + xylene and Triton X-100®, each at 0.04%. By treating the scale while in the second molt, the males were killed but most of the females survived the treatment. Surviving females were as attractive to responsive males as females which had been separated from males by costly hand removal.

Three formulations of 10% aldicarb (as a coke powder, as a granular coke, and as granular corncob grits) were applied, at doses that were 1/4 and 1/2 the manufacturers’ recommended rate, to soil around potted sweet orange seedlings in the greenhouse and under 1-year-old navel oranges in the field, respectively, to suppress Panonychus citri (McGregor). The biossays with the greenhouse seedlings did not show statistically significant difference in mortality of mites for the 3 formulations, and all caused better than 82% mortality for 16 weeks. In the field where the populations of mites were small, the mean suppression by all 3 formulations was 95% for 52 weeks.

Cyclopentadiene, indene, and fluorene react with dichlorocarbene at 550°, giving fulvene derivatives in addition to ring-expanded products.

Reaction of imidazole with dichlorocarbene at 550° gives a mixture of 5-chloropyrimidine and chloropyrazine (10:1).