The “deer lactone”

Urine of the black-tailed deer is the source of the deer lactone, which is deposited on the tarsal gland tufts by rub-urination. The enantiomer composition of the lactone from the urine of the female is 89(R)-(–)/11(S)-(+). Responses by deer were strongest toward the synthetic racemic lactone in the social test and toward the natural lactone in the choice test. In both tests, the (–)- lactone released slightly stronger responses than its enantiomer.Odocoileus hemionus columbianus.     

Inter-versus intramolecular oligomerization of nitrile groups in polyacrylonitrile

Summary Experimental evidence is presented indicating that intermolecular oligomerization of CN groups (leading to crosslinked structures) takes place, and possibly has an even greater importance than the intramolecular reaction (leading to ladder polymer), at higher temperatures. The easy, quasi built-in crosslinking upon heat treatment is considered the most significant single feature with regard to making polyacrylonitrile and its copolymers unique among synthetic polymers as a carbon fiber precursor.     

Interactions between pheromone traps with different strength lures for the pine beauty moth,Panolis flammea (Lepidoptera: Noctuidae)

Catches of malePanolis flammea in traps baited with lures containing 25 g of sex attractant are enhanced when in the proximity of traps baited with 125-g lures. The degree of enhancement is increased as the intertrap distance is decreased, and when the low-dose trap is upwind of the high-dose one. The patterns of alteration in trap catch suggest that moths initially attracted by one lure may divert into other traps, which may be either upwind of the original trap (overshooting), or downwind (undershooting). Overshooting can result in up to fivefold increases in catch and may provide a useful method for estimating the attractant zone of particular lure/trap combinations.     

Rate of radical polymerization of N,N-dimethylaminoethyl methacrylate in cyclohexane

Summary Anions of propene, isobutylene and cycloheptatriene have been prepared using Lochmann's Base. Star polymers in the form of one arm star, two arm star and three arm star polymers of styrene have been synthesized from the allyl anion (2), 2-methylenepropylenyl dianion (4) and the cycloheptatrienyl trianion (6) respectively, with acid end groups by quenching the living polymers with carbon dioxide. The number average molecular weight has been determined by stoichiometry, HPSEC and end group analysis by titration.     

Change in degree of polyamidation of polycaproamide during orientation stretch

Conclusions The effect of stretch ratio, the ratio of stretch ratios in the cold and hot zones, and of the relative viscosity of polycaproamide on the degree of its breakdown during stretching have been examined.The degree of breakdown decreases if the viscosity stays within the range 3.25–3.35, and the stretch ratio in the cold zone is the maximum possible.Translated from Khimicheskie Volokna, No. 5, pp. 26–27, September–October, 1983.     

On the preparation and properties of CuZSM-5 catalysts for NO decomposition

Equilibrium exchange isotherms were determined for the exchange of Cu²⁺ with NaZSM-5 at varying Cu(Ac)₂ concentrations in solutions of constant volume and zeolite weight. At low Cu²⁺ levels the solid scavenged all the copper ions. When copper could be detected in the equilibrated solutions, overexchange was observed. The extent of overexchange was higher at pH 6 than at pH 4. These results were analyzed in relation to catalytic activity.On leave from the Central Institute for Chemistry, Hungarian Academy of Sciences, H1525 Budapest, Hungary.     

Oviposition deterrent from eggs ofCallosobruchus maculatus: Spacing mechanism or artifact?

Females ofCallosobruchus maculatus (F.) avoid ovipositing on host seeds already bearing conspecific eggs, and thus distribute eggs evenly among seeds. This behavior was presumed to be mediated by an ether-soluble oviposition marker that is deposited with the egg and can be extracted from egg-laden artificial hosts (glass beads). Ablation experiments revealed that the true factors promoting an even dispersion of eggs were perceived by the maxillary and labial palpi. In contrast, receptors on the antennae were largely responsible for avoidance of seeds treated with oviposition marker. Taken together, these results suggest that a careful distinction should be drawn between factors that promote spacing of eggs under natural conditions and general oviposition deterrents that may be isolated from both sexes.     

Chemical effects in the assessment of phosphate rock residues extracted from multicomponent fertilisers

Methods of obtaining reactive phosphate rock residues from multicomponent phosphate fertilisers which contain soluble phosphorus components have been examined. Extraction using cold neutral ammonium citrate has been found to be more suitable than water, as chemical reactions appear to occur in water extraction solutions to modify the residue, and more impurity species such as calcium sulphate and iron and aluminium phosphates remain in the residues to complicate the process of obtaining reliable solubility figures.Deactivation of the phosphate rock residues (as measured by decreased 2% formic acid solubilities) was found to be due to reactions occurring during the maturing process, and was dependent on the phosphate rock used, with North Carolina phosphate rock-based residues significantly affected, but Arad-based residues almost unaffected. However, for neutral ammonium citrate extractions, only North Carolina-based residues produced solubility figures lower than the original phosphate rock. Some selectivity of reaction in single superphosphate-reactive phosphate rock mixtures was indicated which further complicated assessment of the deactivation effect; however such an effect appeared to be much less significant than previously suggested.     

Methodological approach to identify chemical oviposition stimulants from maize for European corn borer

The noncontingent distribution ofO. nubilalis Hbn. eggs on various corn varieties has allowed their classification as either favorable or nonfavorable hybrids. This classification is based on a chemical communication system using volatile compounds active at a distance from the insect or active when in contact with the insect as soluble sugar components. Under this hypothesis, gas chromatography is the best way of investigating for the chemical differences between corn silk extracts from the two types of hybrids. A first experiment, using a desorption-trapping system on Tenax coupled to a gas chromatograph showed a quantitative difference between two compounds from the two hybrids. A second experiment showed the advantages and disadvantages of this method and allowed the development of two complementary techniques: (1) direct extraction of corn silk with trichlorofluo-romethane and direct injection into a capillary column with an apolar stationary phase using an on-column system; and (2) extraction under vacuum of volatile compounds from corn silk and their trapping on Tenax, followed by a second desorption. This allows a direct injection on the same capillary column. The first technique allows identification by mass spectrometry of many alkanes with high molecular weights. The second technique seems to confirm the presence of phenylacetaldehyde. Both techniques show quantitative differences in the composition of corn silk extracts from favorable and nonfavorable hybrids; however, the biologically active chemicals remain unknown.     

Role of plant volatiles in resistance of selected rice varieties to brown planthopper,Nilaparvata lugens (Stål) (Homoptera: Delphacidae)

Rice plant volatiles extracted as steam distillates significantly affected the behavior and biology of the brown planthopper,Nilaparvata lugens (Stål). In a multichoice test, more females settled and fed on tillers of a susceptible rice variety Taichung Native 1 (TN1), sprayed with its own extract or acetone than on TN1 tillers sprayed with the extract of the resistant variety ARC6650 or Ptb33. In another test,N. lugens females ingested significantly more of a 10% sucrose solution mixed with TN1 steam distillate extract than of plain sucrose solution or that mixed with extracts of resistant varieties. Topical application of the extracts of resistant varieties Mudgo, ASD7, Rathu Heenati, Babawee, Ptb33, and ARC6650 caused significantly higher mortality of females than did the TN1 extract. Likewise, significantly more first-instar nymphs died when they were caged on susceptible TN1 plants sprayed with the extracts of resistant varieties than on plants sprayed with TN1 extract. The extract of 60-day-old resistant plants was more toxic than the extract of 30-, 45-, or 100-day-old plants. However, toxicity of the extract from susceptible TN1 remained low at all plant growth stages.Principal Research Scientist (ICIPE), based at International Rice Research Institute (IRRI), P.O. Box 933, Manila, Philippines.     

Comparative study of diluent effects on the glass transition of polyvinylchloride and phenolphthalein

Summary Some binary polymer-diluent systems, previously studied by the Authors (SCANDOLA et al., 1982), showed an unusual T_g-concentration dependence. In order to investigate the relevance of the polymeric nature of the high-T_g component in determining this anomaly, two series of mixtures having the same diluent (di-n-Butylphthalate or Tricresylphosphate) and, as the high-T_g component, either a polymer (PVC) or a low-molecular weight substance (Phenolphthalein), have been examined. A discontinuity is found, as expected, in the polymeric systems PVC-di-n-Butylphthalate andPVC-Tricresylphosphate, as well as in Phenolphthalein-di-n-Butylphthalate mixtures where, however, the deviations from the calculated T_g-composition curve are much less marked. It is concluded that the presence of a polymer is not a necessary requirement for the occurrence of the above mentioned anomaly.     

Kinetics and Mechanism of Separation of Water from Polybenzothiazole Fibres

The kinetics and mechanism of separation of water from polybenzothiazole fibres was investigated by mass spectrometry. It is shown that weakly bound and strongly bound water of different origins is separated from fibres during thermal drawing.     

Ultradrawing of “springy” polypropylene films

Summary It is demonstrated that in the process of ultradrawing of semicrystalline polypropylene the morphology of the initial material plays major role. Extremely high draw ratios are obtained (_max50) when drawing hard elastic polypropylene films perpendicular to their initial molecular orientation. This behaviour is explained by the molecular processes of plastic deformation.     

Numerical Simulation of Thermochemical Conversion of a High–Ash Coal in a Low-Temperature Fluidized Bed under Pressure

The paper considers a mathematical model, an algorithm, and a program for calculating nonstationary processes of air gasification of a high-ash coal under pressure in a pilot-scale circulating fluidized bed gasifier reactor. The effect of operation parameters on the course of the process is analyzed. It is shown that hot spots (short-duration local heatings) can form at various points of the bed, at which maximum temperature can be close or even exceed the fluid slagging point. Possible mechanisms of formation of hot spots are analyzed.     

II-I phase transformation of melt-crystallized oriented lamellae of polybutene-1 by shear deformation

Summary Modification II-I transformation of polybutene-1 was investigated on oriented lamellae, which were melt-crystallized in the temperature gradient. WAXS photograph of as-grown specimen showed prefered orientation of [110] to the lamellar axis, and after transformation it showed twelve point pattern due to dual orientation of hexagonal lattice. By shear deformation parallel or perpendicular to lamellar axis, WAXS photograph showed the appearance of six point pattern due to single orientation of hexagonal lattice, and also the enhancement of transformation rate. These were explained by the growth of hexagonal nuclei formed by the slip in the tetragonal crystal.     

Improving water-consumptive processes under conditions of operating viscose fibre manufacture

Conclusions The most water-consumptive technological processes in the basic and auxiliary works in the manufacture of viscose fibre have been identified.Results of realizing the developments of the Khimvolokno NPO and of the Ryazanskii Khimvolokno PO, aimed at reducing water usage and discharge of contaminants into wastewater have been presented.Translated from Khimicheskie Volokna, No. 6, pp. 22–23, November–December, 1984.     

Some Problems in Drawing and Texturing of Vidlon Polycaproamide Fibres

The nature and causes of separation of white powder in drawing and accumulation of deposits on machine chamber walls in texturing of Vidlon polycaproamide fibres are investigated. It was found that the quality of the titanium dioxide suspension and the oiling agent significantly affect separation of powder and passage of the fibre in drawing. Thermooxidative and thermal and mechanical degradation processes in the polymer determine the structure of the fibres and their behavior in drawing and texturing. The amount of white powder separated is a function of the moisture content of the as-spun fibres and the climatic conditions in winding, conditioning, and drawing. The concentration of cross-links in the polymer and inorganic elements on the surface of the fibres and the amount of white powder and deposits on the walls of texturing machine chambers are closely correlated with their passability in drawing.     

Sequential extraction of nine trace elements from sludge-amended soils

Three separate samples taken from particular location of El-Gabal El-Asfar soils treated with composted sludge and irrigated with liquid sludge effluent were compared with untreated soil. These soils were sampled at 5 depths, i.e. 0–15, 15–30, 30–45, 45–60 and 60–75 cm to estimate the forms of nine trace metals in the solid phase. The soils had been amended with sewage sludge and irrigated with sludge liquids for different periods, i.e. 20, 40 and 60 years. The soil samples were fractionated by sequential extraction to estimate the quantities of these metals in exchangeable, sorbed organic, carbonate, and sulfide forms.Data reveal that most of these elements were concentrated (preferential fixation) in the surface layer (0–15 cm), possibly because of the slight decrease in soil apparent density resulting from sludge application. The trace metal contents in exchangeable and sorbed forms of most metals were very low. Sulfide, carbonate and organic forms were shown to be the dominant fractions for most trace metals under study and varied from one element to another. Nevertheless, at least 6 of these metals have a common behaviour.At the longterm addition of sludge application, the predominant metals were: Zn, Fe, Mn, Cr, Ni and Co in sulfide form; Cu in organic form, and Pb and Cd in the carbonate form.     

Molecular mechanics studies of model polysilanes

A molecular mechanics study of a homologous series of di-substituted polysilane model compounds investigates the effect ofn-alkyl side-chain substituent length on overall polymer conformation. Using the recently released MM3 program to probe backbone and side-chain energetics, the results suggest that an off-trans (160°) backbone structure is optimal in both longer-side chain (i.e., di-n-hexyl) and shorter-side chain (di-ethyl) polysilanes. Also a chair-like conformation for side-chain dihedral angles is preferred.This paper is from the Second International Topical Workshop, Advances in Silicon-Based Polymer Science.     

Use of white irons for lining press molds

Summary In production conditions during the pressing of chrome-magnesite brick KhM-1 it was shown that the wear resistance of white iron with HRC- 51 is 2.5 times higher than plates of 20Kh steel after cementation and hardening with HRC=60–62.Gray and mottled irons are poorly resistant to abrasion.White iron of e composition is recommended, for press plates (see table).Alloying iron with chromium, as in the case of composition e is easily ensured by using naturally alloyed iron mark LKhCh-6 in amounts of 25% of the batch.