Non-volatile components of several novel species of edible fungi in China

A nonprotein neurotoxic amino acid, β-N-oxalyl-l-2,3-diaminopropionic acid (ODAP), found in Lathyrus sativus (grass pea or chickling vetch) seeds is known to be relatively heat stable. The present study aims at development of a kinetic model for degradation of ODAP in Lathyrus sativus subjected to a defined set of processing conditions. This study was carried out at pH 4.0 and 9.2. Isothermal condition experiments were carried out over a temperature range of 60–120 °C. For nonisothermal conditions, three different cooking methods viz., – open pan, pressure cooking and cooking in recently developed and patented fuel efficient ‘EcoCooker’ were used. The degradation of ODAP was adequately modeled by Arrhenius type of equation. A mathematical model based on the time temperature data of the nonisothermal heat process and isothermal kinetic rate parameters has been developed to predict the degradation of ODAP in any nonisothermal heating process of known time temperature profiles.     

Scanning electron microscopy study of twins in ZnSe single crystals grown by solid-phase recrystallization

ZnSe single crystals were grown from n-type microcrystalline boules by a solid phase recrystallization (SPR) method. During SPR, twinned regions appear with different electronic recombination properties. The recrystallizations were performed under different atmospheres, Ar or Se, and pressures to investigate the influence of growth conditions on these structural features. Recombination properties were studied by means of cathodoluminescence (CL) and remote-electron beam induced current (REBIC). Wavelength dispersive X-ray (WDX) mappings were also performed to analyze possible differences in stoichiometry related to the presence of extended defects.     

Non-destructive nuclear magnetic resonance image study of belly bursting in herring (Clupea harengus)

Herring (Clupea harengus) captured during the heavy feeding spring season were examined by magnetic resonance imaging (MRI) analysis. MRI was performed at room temperature on the frozen-thawed herring for approximately 50 h. The results showed that the stomachs were filled with prey and that they were very resistant to degradation. The ventral muscle, on the other hand, together with the upper part of the intestine (as confirmed during collection of samples on board fishing vessels), seemed to be the most sensible structures where the autolysis commenced and extended to the rest of the abdominal cavity.     

Interface state generation mechanism in n-MOSFET's

Uniform carrier injection into the channel of n-MOSFETs generates two types of interface states, depending on the oxide electric field: One is linearly proportional to the injected electron density (Type I), while the other shows a half-power dependence (Type II). Charge-pumping measurements in the temperature range of 77K and 263K show that the type I interface states are located in the mid-gap, while the type II interface states are uniformly distributed in wide energy range. Holes generated at the gate/SiO₂ interface or in the oxide are found to be responsible for the type I interface states, while hydrogen or hydrogen compounds diffusing from the interface cause the type II interface states.     

Microstructure changes in the catalyst layers of PEM fuel cells induced by load cycling: Part II. Simulation and understanding

The microstructure of catalyst layers (CLs) is a naturally random medium and changes in it greatly affect the performance of polymer electrolyte membrane fuel cells. In this paper, the mechanical analysis method, developed in Part I for understanding the mechanism of microstructure changes, is further extended to describe CLs as random three-phase microstructures. Microstructure reconstruction is accomplished using statistical information from experimental images of practical CLs. In the microscopically complex reconstructed microstructure, mechanical analysis is performed in order to understand the mechanism of changes caused by the cycling of start-up and shutdown during operation. Numerical simulation shows that, although different reconstructed microstructures have different changes, there have in common the competition between crack initiations in phases and delamination between different phases in the CLs. This competition plays an important role in microstructure change and results in performance degradation, indicated by the decrease in connection length among different solid components in the CLs after certain duty cycles.     

Cooking DNA: the effect of ‘domestic’ cooking methods on detection of GM potato

The ability to detect GM material in otherwise unprocessed foods cooked using domestic methods is important should ‘ready‐to‐eat’ foods require labelling. This study addresses the issue of DNA degradation in foods as a result of cooking. A number of ‘domestic’ cooking methods were shown to affect the length of DNA sequences able to be PCR amplified from potato samples and the degree of degradation was treatment‐specific. However, a. real‐time PCR assay was developed and. GM material was positively identified in all cooked GM potato samples. This confirms that GM material should be able to be detected in otherwise unprocessed food samples cooked using domestic methods, even if the cooking process has partially degraded the DNA. Results indicate, however, that there may be implications of the cooking process on the ability to accurately quantify GM content in some cooked samples.     

An estimate of the limit state of power transformers and autotransformers

The main indicators of the limit technical state of transformers and autotransformers, for which their further use is impermissible or inadvisable, are considered. The main elements of a power transformer which determine its limit state are the windings and the cores. Important indicators for estimating the technical state of the windings is the wear of the coil insulation, the degree of mechanical fastening of the windings and, in particular, the absence of dangerous deformations. Wear of the coil insulation is estimated from the degree of polymerization and the short-circuit resistance. The cores of the transformer become damaged fairly rapidly during operation. Normalized values of the above indicators are given as well as experience in using them in the Russian Federation and the Ukraine to estimate the limit state of transformers and autotransformers. The amount of inspection in order to reach conclusions on the technical state of a transformer and temporary measures until they are replaced are indicated. __________ Translated from élektricheskie Stantsii, No. 1, pp. 44–49, 2008.     

稠油低温氧化降粘剂的合成与性能评价

针对稠油低温氧化降粘技术,探讨了ⅤA族金属氧化物的有机化合物[(Bi2O3)(acac)2](LTO-CB)催化氧化稠油的性能。研究了LTO-CB对稠油的降粘率随反应时间、浓度及温度的变化规律。结果表明,LTO-CB对稠油的低温氧化降粘作用与LTO-CB浓度、氢质子供体以及反应时间有关。LTO-CB在低温条件下通过降解沥青质来有效降低稠油粘度,对不同粘度的稠油降粘率可达50%以上。     

In vitro degradation of 10 mono‐ and sesquiterpenes of plant origin by caprine rumen micro‐organisms

The extent of disappearance of 10 mono‐ and sesquiterpenes in presence of mixed rumen micro‐organisms has been measured in 24‐h batch cultures. The molecules that were tested are frequently found in the plants consumed by ruminants in highland pastures (limonene, β‐myrcene, β‐ocimene, α‐pinene, sabinene, γ‐terpinene and thymol) or are potential markers of the diet (camphene, β‐caryophyllene and α‐copaene). All terpenes were tested at 2 µL mL^?1, except α‐copaene and thymol, which were tested at 0.9 µL mL^?1 and 2 mg mL^?1, respectively. Camphene and thymol were not degraded to a significant extent. The disappearance of part of β‐caryophyllene, (?)‐limonene and γ‐terpinene could not be attributed to the direct action of rumen micro‐organisms but rather than to an effect of the extracellular medium. In contrast, a third group of one sesquiterpene (α‐copaene) and four monoterpenes (myrcene, β‐ocimene, α‐pinene and sabinene) was extensively degraded by rumen micro‐organisms, at rates of 1.6, 4.5, 3.5, 4.8 and 5.4 µmol mL^?1 inoculum day^?1, respectively. The preliminary exposure of rumen micro‐organisms to a specific blend of essential oils compounds, containing mainly thymol, guajacol and limonene, increased the extent of disappearance of γ‐terpinene only. Copyright © 2007 Society of Chemical Industry     

Compound-element modeling accounting for semi-rigid connections and member plasticity

A general model of a compound element is proposed in this article to consider the combined influence of semi-rigid connections and plasticity on the non-linear responses of steel frameworks. The stiffness degradation of semi-rigid connections is modeled by a moment–rotation relationship with four parameters, while the plasticity formation of a member end from initial yield to full yield is modeled by an elliptic moment–rotation relationship. The compound element resulting from the combined influence of member plasticity and semi-rigid connection behaviour is used to facilitate the derivation of member stiffness coefficients where the effects of geometrical non-linearity and member shear deformation are also included for the progressive-failure analysis. On the basis of member plasticity behaviour, the categories of semi-rigid connections are investigated. Three semi-rigid steel frameworks are analysed to illustrate the proposed analysis method, and the results are compared with those obtained from experiments and the application of other methods.