Isolation and identification of cotton synomones mediating searching behavior by parasitoidCampoletis sonorensis

In laboratory bioassays, the parasitoidCampoletis sonorensis was attracted to the following sesquiterpenes isolated from cotton essential oil: -humulene, -bisabolene, -caryophyllene oxide, spathulenol, -bisabolol, and a new, naturally occurring bisabolene-related alcohol, (2-p-tolyl-6-methylhept-5-en-2-ol) which we name gossonorol. This is the first report of spathulenol in cotton. -Caryophyllene, a major component of cotton, was not attractive to the parasitoids. The response of the parasitoids to these compounds and the possibility of augmenting parasitoid activity in the field by manipulating plant secondary metabolites is discussed.Synomone: A chemical produced or acquired by an organism that benefits both the emitting and receiving organisms (Nordlund and Lewis, 1976).     

Shock‐Wave Deformation and Fracture of Zirconium Dioxide Ceramics of Various Fractional Composition and Porosity

The paper reports results from measurements of freesurface velocity profiles of shockloaded zirconium dioxide ceramics with a porosity of 16–22% produced from compositions with a size of the coarse fraction of 0.5–2.0 mm. Shockwave loading of ZrO₂ samples 5–20 mm thick was performed by aluminum impactors 3–12 mm thick with a velocity of 10–100 m/sec. The measured freesurface velocity profiles were used to assess the dynamic compressive and tensile strengths of the ceramics and thedamping properties of the ceramics.     

Cooperative inclusion of sodium 1-pyrenesulfonate by γ-cyclodextrin

Summary The interaction of -cyclodextrin(-CD) with sodium 1-pyrenesulfonate(PS) was studied spectrophotometrically. -CD was found to cause much larger decrease in the absorption maxima of PS than -CD. The fluorescence spectra of PS in the presence of -CD showed excimer emission, while those of PS with -CD showed only monomer emission, indicating that -CD forms 12 (-CDPS) complexes in which two PS molecules are included in the -CD cavity in a face-to-face fashion. The binding isotherm showed a sigmoidal curve. The association constants were estimated by computer simulation of the binding curve. The 12 (CDPS) complex was found to be much more stable (K=10⁶ M^–1) than the 11 complex (K=1 M^–1). At high concentration of -CD another -CD cooperates in binding two PS molecules, resulting in the formation of a 22 complex.     

Performance and impedance studies of thin,porous molybdenum and tungsten electrodes for the alkali metal thermoelectric converter

Columnar, porous, magnetron-sputtered molybdenum and tungsten films show optinum performance as AMTEC electrodes at thicknesses less than 1.0 m when used with molybdenum or nickel current collector grids. Power densities of 0.40 W cm^–2 for 0.5 m molybdenum films at 1200 K and 0.35 W cm^–2 for 0.5 m tungsten films at 1180 K were obtained at electrode maturity after 40–90 h. Sheet resistances of magnetron sputter deposited films on sodium beta-alumina solid electrolyte (BASE) substrates were found to increase very steeply as thickness is decreased below about 0.3–0.4 m. The a.c. impedance data for these electrodes have been interpreted in terms of contributions from the bulk BASE and the porous electrode/BASE interface. Voltage profiles of operating electrodes show that the total electrode area, of electrodes with thickness <2.0 m, is not utilized efficiently unless a fairly fine (1×1mm) current collector grid is employed.     

Combustion of a Mixture of Aluminum and a Titanium‐Containing Raw Material in the Presence of Additives

A model of the gasphase component of combustion of an aluminum mixture with metal oxides is described. By the example of titanium reduction from its oxide, it is shown that atomic oxygen formed thereby facilitates gasphase oxidation of aluminum and decreases metal yield. The effect of graphite, activated carbon, and diesel fuel on combustionwave velocity and temperature is considered. Two waves (cold and hot ones) are observed in the system titanium oxide–ferric oxide–aluminum–carboncontaining additives. Hydrocarbon additives inhibit the aluminumoxidation reaction by oxygen contained in air in the first wave, and graphite and activated carbon play the same role in the second wave in the titaniumreduction reaction. Experimental confirmation is found for the fact that the action of additives increases the amount of aluminum consumed directly for titanium reduction in the second wave, which enhances exothermality of the process.     

Combustion Modes of a Strongly Diluted Ti + 2B System

Combustion modes of a Ti + 2B system with a high mass content of copper and iron (63–83%) are studied for various initial temperatures and compositions of the specimens and the particle sizes of the reagents. The parametric domains of existence of highvelocity and lowvelocity layerbylayer and spin combustion modes are found.     

Convective Combustion of “Gasless” Systems

A convective mechanism of combustion is proposed to explain the anomalously high burning rate of titanium–soot and titanium–soot–polystyrene gasless systems under conditions of onedimensional filtration of impurity gases. An analysis of experimental and theoretical works shows that the convective mechanism of combustion under conditions of impurity gas release may be ensured by the motion of the melted layer of one of the reagents under the action of the pressure difference of impurity gases. Physical and mathematical models of the process are formulated. It is found that a free volume, which is not occupied by the burden, is necessary for an accelerating regime of combustion. It is shows that the front velocity and the gas pressure increase exponentially at the initial stage of combustion and also if the free volume is greater than the specimen volume. Analytical expressions for the mean convective burning rate are derived. Consideration of the model formulated in the present paper offers an explanation of the differences in the burning laws of gasless systems, which are observed in experiments under conditions of counterflow, cocurrent, and twosided filtration of impurity gases.     

Evolution of weak shock waves in dense media

Relations describing the evolution of a weak shock wave (SW) in a dense medium with account of its attenuation and spreading are derived. The evolution is presented as a result of superposition of two processes: propagation of a stepped weak shock wave and pursuit of the shock by a rarefaction wave.Moscow. Translated from Fizika Goreniya i Vzryva, Vol. 31, No. 2, pp. 139–143, March–April, 1995.     

Attraction ofCacoecimorpha pronubana male moths to synthetic sex pheromone blends in the wind tunnel

Attraction ofCacoecimorpha pronubana male moths to blends of four sex pheromone components was studied in the wind tunnel.Z11–14Ac alone did not elicit upwind flight, admixture of 10%Z11–14OH or more led to successful attraction of males to the source. Attractivity of these binary blends was further enhanced by addition ofE11–14Ac orZ9–14Ac; the optimum was a blend ofZ11–14Ac,Z11–14OH,E11–14Ac, andZ9–14Ac at the proportion of 1003033. In ternary and quaternary blends, the effect ofZ11–14OH andE11–14Ac was strongest at 30% and 3%, respectively. By contrast,Z9–14Ac increased behavioral responses over a wide range.     

Triggering of Detonation upon Flame Interaction with an Expansion Wave

The transition of a deflagration wave into an abruptly expanding part of a plane channel, where a quasisteady supersonic underexpanded jet of an unburned gas is formed, is studied for a propane–oxygen mixture using schlieren pictures. Two explosioninitiation modes (weak and strong) are registered. In the first case, almost instantaneous onset of the detonation wave occurs when the flame front enters the expanding section; the initial velocity of this wave is approximately 1.5 times the Chapman–Jouguet detonation velocity (D_CJ) and then decreases to a value corresponding to selfsustaining detonation. In the second case, the front velocity gradually increases from 0.4D _CJ to 1.0D _CJ. It is established that the starting pulse triggering the transformation of turbulent combustion to explosion and detonation regimes is generated by interaction of the flame front with expansion waves, which are elements of the structure of the initial section of the jet.     

Heterogeneous asymmetric reactions. 23. Enantioselective hydrogenation of ethyl pyruvate over cinchonine- and α-isocinchonine-modified platinum catalysts

The enantioselective hydrogenation of ethyl pyruvate to (S)-ethyl lactate over cinchonine- and -isocinchonine-modified Pt/Al₂O₃ catalysts was studied as a function of modifier concentration and reaction temperature. The maximum enantioselectivities obtained under the applied mild conditions were 89% ee using cinchonine (0.014 mmoldm^–3, 1 bar H₂, 23°C, 6% AcOH in toluene), and 76% ee in the case of -isocinchonine (0.14 mmoldm^–3, 1 bar H₂, –10°C, 6% AcOH in toluene). Since -isocinchonine of rigid structure exists only in anti-open conformation these data provide additional experimental evidence to support the former suggestion concerning the dominating role of anti-open conformation in these cinchona-modified enantioselective hydrogenations.     

Prediction of Reverse Relaxation and Deformation—Recovery Processes in Synthetic Fibres

Use of force and geometric deformation variants of the nonlinear-hereditary viscoelasticity equation for prediction of complex processes by calculation is examined on the example of deformation-recovery and reverse relaxation processes in Lavsan synthetic fibres. A comparison of the calculated and measured values allows recommending the method of calculated prediction in which an elementary function — the normalized arctangent of the logarithm of the reduced time serves as the normalized relaxation or creep function.     

Fe3+--gluconate and Ca2+-Fe3+--gluconate complexes as mediators for indirect cathodic reduction of vat dyes – Cyclic voltammetry and batch electrolysis experiments

The indirect cathodic reduction of dispersed vat dyes CI Vat Yellow 1 and CI Vat Blue 5 was investigated by cyclic voltammetry and with batch electrolysis experiments. 0.01molL^–1 solutions of the complexes Fe³⁺--gluconate and Ca²⁺-Fe³⁺--gluconate were studied. The addition of dispersed dyestuff to the mediator solution lead to a catalytic current. While the cathodic peak currents of both complexes is comparable, Fe³⁺-DGL shows higher enhancement factors, which are defined as quotient of catalytic peak current and cathodic peak current of the mediator system (I_p)_c/(I_p)_d. In the presence of 0.5gL^–1 of dispersed vat dye enhancement factors of 1.8 were determined at scan rates of 0.005–0.010Vs^–1. Galvanostatic batch reduction experiments with use of a laboratory multi-cathode cell confirmed the favourable properties of the Fe³⁺-DGL in comparison to the binuclear Ca²⁺-Fe³⁺-DGL. With use of the Fe³⁺-DGL mediator complete dyestuff reduction could be achieved. The batch reduction process was followed experimentally by photometry and redox potential measurement in the catholyte.     

Investigating the phase composition and structure of laboratory specimens duplicating compositions of open-hearth furnace bottoms

Conclusions A simple method, proposed for modelling the material, grading and chemical compositions of the hearths of open-hearth furnaces, permitted us to make comparative evaluations of the phase composition and structure of hearths in relation to the grading of the powder, the amount of sinter, the grain size of the dolomite, etc.To obtain dense and high-temperature-resistant hearths, metallurgical powder should be used with a limited grain size (not more than 5–10 mm).A favorable effect on the development of the hearth is had by the fine fraction of magnesite (below 0.1 mm) which helps to increase recrystallization of periclase in the bond part of the hearth.The amount of sinter added to the magnesite powder should not exceed 35%, since more leads to a decomposition of the solid solutions of magnesioferrite in the periclase and weakening of recrystallization.Together with the recrystallization of periclase in the coarse grains (pieces) recrystallization should be accomplished in the periclase of the bond part of the hearth.Such a development in the process of recrystallization greatly helps densification of the hearths.Titanomagnetite concentrate should be added in limited amounts and well distributed in the magnesite powder.A high content of titanomagnetite concentrate or unsatisfactory distribution helps to develop easily fusible titanates in the bond part of the hearth.Dolomite added to the magnesite powder can be profitably added in as fine a state as possible, since this helps more intense recrystallization of periclase and a reduction in the easily fusible ferritic interlayers between the crystals of periclase.The investigation permits us to make the following important recommendations for the practice of fettling and ramming open-hearth furnaces:use of a rational fine grain composition of magnesite powder with a maximum grain size of not more than 5–10 mm, the amount of the below-0.5 mm fraction 40–50% including not less than 15% finer than 0.1 mm;limitation of the amount of added sinter and titanomagnetite concentrate and careful distribution of the latter;the introduction of dolomite in the form of particles as fine as possible.     

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.     

Structure and thermal stability of zinc–nickel electrodeposits

ZnNi alloys were electrodeposited from a chloride bath on steel substrates. The effect of nickel bath concentration on chemical composition, structure and microstructure of the deposits is demonstrated. From 0 to 13 nickel, the phases obtained do not correspond to that reported on the thermodynamic phase diagram. It is shown that the substitution of zinc by nickel is responsible for the formation of distorted _d and _d phases corresponding to the supersaturated hexagonal phase of zinc and to the unsaturated cubic phase of Zn–Ni alloy, respectively. Differential scanning calorimetry indicates that the thermal instability of the alloys containing up to 13 wt of nickel, results from the crystallization of the phase from the _d and _d phases at around 200 °C and 250 °C, respectively.     

Characterization of the conformers in poly(3,3-diethyl oxetane) by vibrational spectroscopy

Summary The monoclinic and orthorhombic conformers of Poly(3,3-Diethyl oxetane) can be obtained depending on crystallization temperature. However, if the crystallization of a given modification is unaccomplished, the other modification can be crystallized from the amorphous phase. The molecular vibrations in the region 700–800 cm^–1, which are associated with the breathing mode, are highly dependent on the conformation of the polymer chain. This band is used to study the influence of the temperatures and times of crystallization on the structural modifications of this polymer.     

Reductive transamination of methoxyacetone with benzylamine over Pd/SiO2 catalyst modified with anchored chiral compounds

Methoxyacetone was transaminated with benzylamine to methoxyisopropylamine over a Pd/SiO₂ catalyst modified with Lalaninol or Lphenylalaninol covalently anchored to the surface of the support via an organosilicon spacer group. In the first step of transamination a Schiff base was formed from the ketone and benzylamine, and then it was hydrogenated in the second step on the chirally modified Pd/SiO₂ catalysts to an asymmetric secondary amine (Nbenzylmethoxyisopropylamine). In the third step the hydrogenolysis of the asymmetric secondary amine resulting in methoxyisopropylamine and toluene was carried out over a 10 wt% Pd/C catalyst. The highest enantiomeric excess of (S)methoxyisopropylamine was observed in cyclohexane (ee = –20–21%) using anchored Lalaninol as a chiral modifier.     

Corrosion behaviour of Zn–Co compositionally modulated multilayers electrodeposited from single and dual baths

The corrosion behaviour of Zn–Co compositionally modulated multilayers (CMM) was studied using corrosion potential measurement and the neutral salt spray (NSS) method. It was established that the corrosion potentials of the CMM, deposited from a single bath, are significantly more positive than those deposited from a dual bath. The best corrosion resistance was found for multilayers consisting of four sublayers, each 3.0m thick, deposited both from a dual bath and from a single bath (with an oversublayer of Zn–Co1%).     

Phase-structure analysis of brass by anodic linear-sweep voltammetry

Anodic linear-sweep voltammetry (ALSV) was applied to electrodeposited alloy layers and to metallurgically obtained Cu–Zn alloys of different composition and structure. Metallurgically obtained samples covered the range of composition in which , (+), and (+) intermediate phases were detected by X-ray. The ALSV of samples containing less than 30 wt % Zn exhibited a single peak at –0.08 to –0.1 V/SCE before massive dissolution, starting at about –0.05 V/SCE. The presence of the -phase gave another peak at a significantly more negative potential (–0.25 to –0.35 V/SCE). The ALSV of electrodeposited alloys were significantly more complex than the former, depending on the deposition potentials, with peaks attributable to pure Zn, to the -phase, to the -phase as well as to the -phase, present in most cases and dissolving at potentials similar to that of pure Cu. ALSV was shown to be a reliable and practical method for a fast determination of both the composition and the phase structure of electrodeposited brass.