The biodegradability of two primary alcohol ethoxylate nonionic surfactants under practical conditions,and the toxicity of the biodegradation products to rainbow trout

A field trial has been performed to measure the biodegradability of two typical alcohol ethoxylate nonionic surfactants, “Dobanol” 45-7 and “Dobanol” 45-11, by dosing them to biological filters in a mixture with domestic sewage. Influent levels were 10 and 25 mg l^?1 of each surfactant and 96–98% degradation was achieved within a temperature range of 5–10°C. The surfactants had no adverse effects on the filters in terms of the usual sanitary parameters (BOD, COD, TOC and ammoniacal nitrogen). Tests on the effluents indicated no residual acute lethal toxicity to rainbow trout Salmo gairdneri).     

Tetrameric rhenium complexes with a glycine-thiourea derivative

[ReNCl₂(PPhMe₂)₃] reacts with the glycine ethylester derivative Et₂NC(S)NC(Ph)NHCH₂COOEt, HL(GlyEt), in methanol under hydrolysis of the ester and formation of the tetrameric, nitrido-bridged rhenium(V) compound [{ReN{fac-L(Gly)}(PMe₂Ph)}{ReN{mer-L(Gly)}(H₂O)}]₂. Both facial and meridional coordination has been found for the tridentate {L(Gly)}^2? ligand in the building blocks of the tetramer. Syn and anti isomers with respect to the PPhMe₂ ligands have been isolated and characterized by X-ray diffraction.     

Evidence for terror management theory II: The effects of mortality salience on reactions to those who threaten or bolster the cultural worldview.

Three experiments were conducted to test the hypothesis, derived from terror management theory, that reminding people of their mortality increases attraction to those who consensually validate their beliefs and decreases attraction to those who threaten their beliefs. In Study 1, subjects with a Christian religious background were asked to form impressions of Christian and Jewish target persons. Before doing so, mortality was made salient to half of the subjects. In support of predictions, mortality salience led to more positive evaluations of the in-group member (the Christian) and more negative evaluations of the out-group member (the Jew). In Study 2, mortality salience led to especially negative evaluations of an attitudinally dissimilar other, but only among subjects high in authoritarianism. In Study 3, mortality salience led to especially positive reactions to someone who directly praised subjects' cultural worldviews and especially negative reactions to someone who criticized them. The implications of these findings for understanding in-group favoritism, prejudice, and intolerance of deviance are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative estimation of the action of α-amylase from Bacillus subtilis on native corn starch by HPLC and HPTLC

 The optimal conditions of corn starch liquefaction and dextrinization using α-amylase from Bacillus subtilis to obtain maltodextrins with a dextrose equivalent of 12.9–23.5 were determined. The pattern of action of B. subtilis α-amylase on native corn starch was monitored using high-performance liquid chromatography (HPLC) and high-performance thin layer chromatography (HPTLC). It was possible to separate malto-oligosaccharides of up to 9 glucose units by HPLC and those of up to 12 glucose units by HPTLC, respectively. The results suggest that α-amylase from B. subtilis is an endo-specific enzyme which mainly produces two oligosaccharides, DP3 and DP6. It was shown that both methods can be successfully applied for the characterization of maltodextrins. Received: 22 August 1997     

Optical eigenmodes of a cylindrical microcavity

Abstract

The optical mode structure of a cylindrical microcavity has been investigated using a transfer matrix approach. We derive exact algebraic equations from which the frequencies of the optical eigenmodes of the two polarizations can be obtained, as well as approximate explicit algebraic expressions for those frequencies.     

Spontaneous emission control in semiconductor microcavities withmetallic or Bragg mirrors

We present a systematic study of the modification of the spontaneous emission of a point dipole in a planar semiconductor microcavity, bounded by different types of mirrors. Numerical evaluations of the spontaneous emission rate indicate that semiconductor cavities bounded by Bragg mirrors display only a weak modification of spontaneous emission, while significant enhancement and inhibition of spontaneous emission should be observed in cavities bounded by metallic mirrors     

A Strategy for Analysis and Modelling of Impedance Spectroscopy Data of Electroceramics: Doped Lanthanum Gallate

Modelling of impedance spectroscopy (IS) data of electroceramics depends critically on the correct choice of equivalent electrical circuit so that the extracted parameters have physical significance. The strategy proposed to choose the correct circuit involves analysis of IS data in several of the four complex formalisms: impedance, electric modulus, admittance and permittivity together with consideration of the frequency and temperature dependence of data and the magnitude and temperature dependence of extracted resistance and capacitance values. This is demonstrated using IS data from oxide-ion conducting La_0.80Sr_0.20Ga_0.83Mg_0.17O_2.82 ceramics over the range 182 to 280°C. Low temperature data are fitted first, to allow a full characterisation of the bulk response; some of the bulk parameters may then be fixed to enable fitting of the higher temperature data which increasingly feature lower frequency phenomena such as grain boundary impedances. The most appropriate circuit in this case is found to consist of a parallel combination of a resistor, capacitor and constant phase element (CPE) for the bulk response in series with a resistor and capacitor in parallel for a constriction resistance. The origin of the constriction resistance may be associated with the presence of plate-like LaSrGaO₄ secondary phase within the grains and/or with the presence of pores at the grain boundaries. The importance of choosing (a) the correct equivalent circuit and (b) approximately correct input values for the various circuit parameters to be fitted and refined are demonstrated.     

Avalanche multiplication properties of GaAs calculated from spatially transient ionisation coefficients

In this paper the high field phenomenon of avalanche multiplication in a GaAs p-i-n infrared detector is studied using a Monte-Carlo simulation. The Lucky-Drift model of impact ionization is used to give the characteristic lengths for transport through the device. The transport is then modelled by generating motion consistent with the probability functions derived from the mean free paths. This produces a spatially transient ionization coefficient for each carrier and allows the realistic statistical simulation of avalanche multiplication. Properties such as mean gain, multiplication noise and the transient response to a photonic pulse have been calculated and explained for a length of i-GaAs, with an emphasis on short active region phenomena. The effect on the ionization coefficients of a periodic field change has been investigated. It has been found that the effective carrier deadspace is approx. 1.35 times the absolute deadspace. The transient current calculations indicate the narrow bandwidth of this type of device. The presence of a periodic field change, caused by periodic δ-doping, was found to increase both electron and hole ionization coefficients by different proportions.