The OECD QSAR Toolbox is a software application intended to be used by governments, the chemical industry and other stakeholders in filling gaps in (eco)toxicity data needed for assessing the hazards ...of chemicals. The development and release of the Toolbox is a cornerstone in the computerization of hazard assessment, providing an 'all inclusive' tool for the application of category approaches, such as read-across and trend analysis, in a single software application, free of charge. The Toolbox incorporates theoretical knowledge, experimental data and computational tools from various sources into a logical workflow. The main steps of this workflow are substance identification, identification of relevant structural characteristics and potential toxic mechanisms of interaction (i.e. profiling), identification of other chemicals that have the same structural characteristics and/or mechanism (i.e. building a category), data collection for the chemicals in the category and use of the existing experimental data to fill the data gap(s). The description of the Toolbox workflow and its main functionalities is the scope of the present article.
We report the fabrication of 1.5–1.6 μm light-emitting modules based on an AlGaInAs/InP heterostructure with strain-compensated quantum wells in new, smaller, thermally stabilized housings. Their ...performance is tested under extreme operating conditions. The reliability of such modules and stability under the influence of climatic factors is studied.
The variation of elastic and electromechanical properties of microtubes of diphenylalanine dipeptide as a function of the degree of filing of nanochannels by water molecules is reported in this ...paper. Quantum chemical calculations reveal different contributions of water layers in the microtubes to Young's modulus and the effective piezoelectric coefficient. The application of diphenylalanine microtubes in micro-electromechanical systems is also discussed.
We studied the features of PAHs extraction by QuEChERS in the sample preparation of soils and bottom sediments of various compositions followed their determination by gas ...chromatography–mass-spectrometry. The test samples were soils of sandy, loamy sand, loamy, and clayey types and bottom sediments of loamy sand type. The mineralogical composition and organic matter content of the samples were used to predict how PAHs were retained by the soils and sediments. The impact of ultrasonic treatment on analyte extraction with subsequent identification by chromatography was assessed. No ultrasonic treatment was required to extract and determine all PAHs (up to 100%) in sandy and loamy sand soils and low-molecular-weight PAHs in all test samples. The QuEChERS extraction and determination of high-molecular-weight PAHs in clay type soil samples and loamy sand bottom sediments required a 10-min ultrasonic treatment, while the recoveries of analytes were higher than 87 and 90%, respectively. The analysis of a loamy soil sample with a high organic matter content was the most challenging. To extract over 70% of high-molecular-weight PAHs from a sample of this type using the QuEChERS technique, the binary acetonitrile–acetone (1 : 1) extractant rather than conventional acetonitrile was used with the simultaneous 15-min ultrasonic treatment.
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We have studied the growth of zinc selenide layers on flat and shaped indium phosphide surfaces. The growth rate of zinc selenide has been shown to depend on substrate orientation. It has been ...shown that the present results can be useful in designing mesa stripe structures for quantum electronic instruments. We have fabricated mesa stripe laser diodes operating on the absorption band of methane and suitable for producing fiber-optic signal transmission systems.
Data on the main sources of nutrient load on Lake Onego watershed were collected along with the available data of field observations of nitrogen and phosphorus inflow into the lake. Mathematical ...modeling was used to assess the agricultural load onto the lake and its possible decrease due to the introduction of the best available techniques to agricultural production. It was shown that a decrease in agricultural load after the introduction of best available technologies is unlikely to have a significant effect on the ecological conditions of Lake Onego. Simulation calculations were carried out to evaluate an increase in the input of N and P into the lake from fish farms on the watershed under the condition that the rate of fish farming growth in the water bodies in the basin will remain the same up to the year of 2050. It is shown that, in this case, an increase in nutrient load onto the lake by 3.9% for P and by 1.9% for N relative to the current values can be expected. The most significant increase in nutrient export can be expected in Zaonezh’e: 11.2% for P and 10.6% for N. The possible changes in N and P input into the lake by the late XXI century due to changes in the runoff from the watershed is estimated under two RCP-scenarios—RCP 2.6 and RCP 8.5—the best and the worst in terms of their environmental effect. The actualization of scenario RCP 2.6 may lead to a decrease in the nutrient load all over the lake to 12.9% for N and 20.5% for P due to an increase in the flow. The actualization of the environmentally unfavorable scenario RCP 8.5 can be expected to cause an increase in runoff and an appropriate increase in the export of N from the entire watershed by 16.9% and P by 26.7%.
Boswellia serrata resin (BSR), exhibiting a variety of therapeutic properties, is applied in Asian traditional medicine. These properties can be used in poultry production as well. Application of the ...resin as a phytobiotic in broiler chicken rearing can increase the productivity and improve meat quality. However, the optimum and maximum levels of BSR in broiler diets need to be assessed. The study determined the effect of different levels of supplementation of BSR (directly derived, unprocessed) in diets for broiler chickens on the production traits, selected slaughter analysis parameters, nutrient digestibility and selected hematological, biochemical and immunological parameters. In total, 200 1-day-old broiler chickens were assigned randomly to four treatments with five replicate cages of 10 broiler chickens/cage (five females and five males). The experiment lasted 6 weeks, and the broiler chickens were fed diets containing 0% (control), 3% (BSR3), 4% (BSR4) or 5% (BSR5). In the broiler chickens receiving diets with addition of resin BSR3 and BSR4, there was an increase in (P<0.05) BW gain, ether extract, ADF, organic matter and energy digestibility of the diets. Moreover, the best carcass quality with a high proportion of muscles and low abdominal fat content (P<0.05) was noted in these groups. The content of uric acid (P<0.01) and the activity of aspartate aminotransferase (P<0.001) and alkaline phosphatase (P<0.05) in blood plasma decreased upon the BSR supplementation. Globulin content increased in blood plasma (P<0.05) along the increasing level of BSR. The blood immunoglobulin A concentration was only affected by the BSR treatments (P<0.05). It may be concluded that BSR can be regarded as a safe and effective dietary additive for broiler chicken.
A Precision High Voltage Pulse Divider Batrakov, A. M.; Vasilev, M. Yu; Kotov, E. S. ...
Instruments and experimental techniques (New York),
04/2020, Letnik:
63, Številka:
2
Journal Article
Recenzirano
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A the high-voltage divider for pulsed signals was developed for multichannel DAQ-system of the LIA-20 linear induction accelerator. The divider satisfies a range of requirements: a range of ...operating voltages up to 30 kV, a 30 MHz bandwidth, accuracy and stability characteristics that are better than 1%, and repeatability of its parameters during mass production. An analysis of various variants of high-voltage dividers is given: passive capacitive dividers and capacitive dividers with active components, as well as resistive, resistive-capacitive, and combined dividers. The configuration selection of the divider circuit with the necessary properties is substantiated based on the analysis.
This work is devoted to a study of the life cycle of silica gel adsorbents of the ASM brand used in natural-gas purification, as well as to establishing the factors affecting their catalytic activity ...under the conditions of methanol conversion to dimethyl ether. The elemental and phase composition, specific surface area, and pore volume of commercial adsorbents have been established by X-ray fluorescence, X-ray phase, synchronous thermal analysis, and low-temperature nitrogen adsorption, and relationships with their catalytic activity have been studied. The dependences of the yield of dimethyl ether on the time of operation of adsorbents at gas-treatment gas-transportation units (GTUs) have been studied. It is shown that the phase state of the original, spent, and regenerated adsorbents does not change during their operation. A decrease in the thermal catalytic activity of the adsorbent under the conditions of the conversion of methanol to dimethyl ether over time during the operation of GTUs was found, which is due to a decrease in their specific surface area and specific pore volume, as well as the accumulation of various organic components (turbine oil) and sulfur.
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