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The work considers the hydrodynamics in contemporary packed film devices with tubular and plane channels and laminar and turbulent gas- and liquid-flow patterns in a downflow cocurrent regime. Weak hydrodynamic interaction between the phases and no velocity circulation in the gas phase are assumed. The solution is found by the approximate Schlichting method. The distribution of velocities in the phases, the thickness of the downflowing film, and the sizes of the inlet hydrodynamic areas in the liquid and gas are determined. [ABSTRACT FROM AUTHOR]

The friction and wear characteristics of the developed nanostructured glass-composite self-lubricating coatings, the structural components of which have a qualitative influence on the graphitization process and ensure the formation of an α-graphite surface layer which minimizes contact parameters, were investigated. The positive role of the glass phase in the form of aluminoborosilicate, which changes the tribological properties of coatings, was established. The increase in adhesive strength achieved due to the formation of glassy sodium silicate surface layer during spraying was established. It is stated that the intercalation of the graphite layer by the particles of the subsurface zone does not influence sufficiently the tribotechnical characteristics of the coatings. The developed nanostructured glass coatings demonstrate high antifriction characteristics throughout the entire load-speed range of tests. [ABSTRACT FROM AUTHOR]

The Integrated Energy System (IES) of Ukraine functions as part of the European Union (EU) electric power system ENTSO-E. Each country whose IES operates in the ENTSO-E structure must ensure the presence of a full-fledged frequency and power automatic control system (AFPCS, AFPC system) in the national IES. The only exception is the IES of Ukraine, because its inclusion in the ENTSO-E happened during martial law and in the absence herewith of a fullfledged AFPC system. It violates the cornerstone requirements of the ENTSO-E structure formation. In the post-war period, the IES of Ukraine will be obliged to complete its own, full-fledged AFPCS as soon as possible. Three structures of the AFPC system development of the Ukrainian IES were studied: according to the traditional principle (on the basis of generators-regulators); on the basis of heat consumers-regulators with the involvement of heat pump installations and on the basis of heat consumers-regulators using electric heat generators that provide energy for the centralized heat supply system. Calculations and analysis of technical and economic indicators showed that the traditional structure of AFPCS extremely loses to both structures built on consumers-regulators. Significantly better of these two systems is the AFPCS, built on consumers-regulators in the form of electric heat generators. It provides an annual net profit of more than 1.8 billion USD, with a payback period of about 0.5 years, reduces by 2.7 billion m3 of natural gas consumption, reduces by 13.9 billion USD needs capital investment, has short construction deadlines. References 20, tables 5. [ABSTRACT FROM AUTHOR]

A model of steam reforming of pure ethane in a membrane catalytic reactor is proposed. The working elements of the reactor are cylindrical chambers, between which a hydrogen-selective palladium foil is placed. The upper chamber is vacuumized, and the lower one contains a nickel catalyst. In the case of uniform feed of the feedstock (С2Н6 and Н2О) along the perimeter of the lower chamber, the problem is reduced to finding the average flows of С2Н6, СН4, Н2О, СО, СО2, and Н2 by solving a system of nonlinear ordinary differential equations. The studies are carried out in the temperature range of 700–1000 K at acceptable steam/ethane input flow ratios of more than four. The optimal conditions for the process, at which the hydrogen yield is 100%, are found. It is proved that under these conditions and a fixed temperature, the maximum hydrogen flow through the membrane is observed at the minimum permissible ratio of the steam and ethane input flows, equal to four. Comparison of the calculations with the experimental data confirm the assumption of the existence of two sections in the lower chamber (short initial and main sections). [ABSTRACT FROM AUTHOR]

Small-aperture transducers based on the magnetostrictive effect for the emission and reception of signals in the ultrasonic range in solid materials have been developed. The article discusses their design features and specifications. Attention is paid to the features of the choice of materials, shapes, and geometrical dimensions of the excitation coil, damper, and magnet. Structural and electrical circuits of the developed transducers are given. Some design and technological solutions have been proposed that can increase the radiation power by 10 times, and resolution by 2-3 times, compared with existing analogs. The area of the radiating part of the sensor is from 0.07 to 0.2 mm2 . Such transducers can be used in various diagnostic systems to detect defects in power equipment, aircraft products, industrial equipment, etc. [ABSTRACT FROM AUTHOR]

The results of a study of the friction and wear characteristics of the developed nanostructured glass-composite self-lubricating detonation coatings with the composition SiC–Ni–Cu–Al–Si–C additionally containing a SiO2–Al2O3–B2O3 aluminoborosilicate glass phase and structurally free MgC2, which forms α‑graphite during thermal decomposition are presented. It is indicated that their synergistic effect promotes the creation of an antifriction surface layer that minimizes contact parameters. An increase in the adhesion strength of the coatings is achieved by preliminarily applying a sublayer of glass-like sodium silicate Na2O(SiO2)2 onto the working surface. It is noted that the intercalation of the graphite layer by the particles of the subsurface zone does not affect the tribotechnical characteristics of the coatings. The developed coatings show high performance properties; here, the way of wear stabilization is the presence of a thin-film antifriction layer based on α-graphite, which shields unacceptable processes of molecular adhesion interaction. [ABSTRACT FROM AUTHOR]

A model is proposed for steam reforming of methane in a catalytic reactor, the working section of which includes two cylindrical chambers separated by a palladium foil membrane of the Pd, Pd–23% Ag, Pd–6% Ru, Pd–10% Ru, Pd–6% In–0.5% Ru, and Pd–6% In compositions. The upper chamber is evacuated and the atmospheric pressure is maintained in the lower chamber. Upon uniform feed of raw materials to the lower chamber, the problems are reduced to determination of the CH4, H2O, CO2, CO, and H2 flows from the solution of a system of first-order nonlinear ordinary differential equations. The 100% conversion of methane is achieved only when the ratio of water steam and methane input flows is more than two. Calculations are performed in the temperature range 700 1000 K at the ratio of steam/methane input flows belonging to this range [2, 10]. The optimum values of input flows of raw materials, at which the yield of hydrogen and the conversion of methane reach 100%, are determined. At optimum flows and specified temperature, the maximum hydrogen flow through the membrane is observed at the minimum permissible ratios of steam and methane input flows. [ABSTRACT FROM AUTHOR]

A model of steam propane reforming in a catalytic reactor was developed. The main reactor elements were two cylindrical chambers separated by a thin partition (highly hydrogen-selective palladium foil or impermeable steel plate). The upper chamber was evacuated, and the lower chamber was filled with a nickel catalyst and was maintained under constant pressure. The feed (C3H8 and H2O) was uniformly introduced through the perimeter of the lower chamber; in this case, the problem reduced to the determination of the average fluxes of C3H8, CH4, H2O, CO, CO2, and H2 via the solution of six first-order, nonlinear, ordinary differential equations. The study was carried out in a temperature range of 673 K < T < 823 K at a steam : propane inlet flux ratio of 5 and a feed flow rate of 1800–3600 1/h. A comparison between the calculated and experimental data confirmed the assumption that there are two steam reforming ranges (a short initial range and the main range). It was proven that the optimal conditions of steam propane reforming are a feed flow rate of ∼2000 1/h and a temperature of ∼800 K. [ABSTRACT FROM AUTHOR]

The article describes the approach to the formation of a simulation model of information signals, which are typical for objects with different types of defects. The dispersive analysis of the signal spectrum components in the bases of the discrete Hartley transform and the discrete cosine transform is carried out. The analysis of the form of the reconstructed information signal is carried out depending on the number of coefficients of the spectral alignment in Hartley bases and cosine functions. The basis of orthogonal functions of a discrete argument is obtained, which can be used for the spectral transformation of information signals of a flaw detector. A method of simulation of information signals has been developed and experimentally investigated, which allows taking into account the deterministic and random components of the characteristics of real information signals. References 24, figures 13, tables 3. [ABSTRACT FROM AUTHOR]

Isothermal absorption of components from dilute gaseous mixtures by falling film of liquids in irrigated plane-parallel channels for co-current laminar flows of liquid and gas were modeled taking into account the processes occurring at the gas entrance. A solution was obtained in the form of analytical expression and reduced to the solution of particular limited problems for the cases when the resistance is concentrated within the gas or the liquid. For visual representation of fluxes the plane of hydrodynamic parameters was suggested. The calculations can be carried out inside of a limited area of the plane. Outside of the area, some simplifications can be adopted: (a) mass transfer resistance is concentrated in a gas or in a liquid and (b) the concentration changes in transversal directions can be neglected or there is a boundary diffusion layer in the gas or the liquid. It was shown that in calculating of the process of gas cooling by the transversal temperature gradients in the liquid can be neglected. The restrictions on temperature difference at the entrance were found, according to them the corresponding thermophysical coefficients can be assumed to be constants and the heat exchange can be calculated using the relationships derived for isothermal absorption. The method can be applied to a wide class of problems which can be reduced to solving of convection diffusion equations with more difficult interphase boundary conditions. Compared to existing numerical and analytical methods, our approach advantage is in its simplicity, visual representation, and shorter computation time. [ABSTRACT FROM AUTHOR]

A model of steam methane reforming in a catalytic reactor has been developed the working part of which is two cylindrical chambers separated by a membranous wall. The upper chamber is evacuated while the lower one is maintained at atmospheric pressure. With a uniform supply of raw materials along the outer perimeter of the lower chamber, the problem is reduced to finding the average flows of CH4, H2O, CO2, CO, and H2 from the solution of a system of five nonlinear ordinary differential equations of the first order. The calculations were carried out for a Pd–6% Ru membrane in the temperature range of 673 K < T < 973 K at a steam/methane inlet flow ratio of 3 and a feed rate of 1800–9600 L/h. As a result of comparing the calculations with experimental data, a theoretical substantiation of the main regularities of the process observed in practice was obtained. [ABSTRACT FROM AUTHOR]

The propane conversion in a membrane reactor with NIAP–03-01 commercial Ni catalyst at temperatures of 673, 723, 773, and 823 K, feed space velocities of 1800 and 3600 h–1, and steam/propane ratios of 5 and 7 was studied. The Н2 removal through the membrane leads to an increase in the conversion of the feed to Н2 and СО2 formed by the water-gas shift reaction. The conversion in this reaction increases when the rate of the Н2 recovery through the membrane is increased by the permeate evacuation. In the temperature interval 773–823 K, the feed conversion is 100%, and about 90% of high-purity Н2 is recovered from the reaction mixture. An increase in the feed/catalyst contact time leads to a decrease in the feed conversion to the target products and to an increase in the rate of carbon deposit formation. The regularities of the steam conversion of propane in a membrane reactor are similar to those found previously for n-butane with the same catalyst and under the same conditions. [ABSTRACT FROM AUTHOR]

The results of studying the characteristics of friction and wear of the developed detonation nano-component coatings of Fe–Ti–SiC that also contain MgC2, are presented. Due to the interrelation of thermal and mechanical fluctuations, magnesium carbide thermally decomposes and forms structurally free α‑graphite. This graphite creates a surface antifriction layer, which minimizes the contact parameters. In the study of the wear resistance of detonation coatings of nanocomponent powders, samples with coatings of the tungsten-containing VK15 hard alloy were tested for comparison using similar programs, as well as coatings sprayed with nichrome alloyed powder. Modern physical and chemical methods studied the qualitative and quantitative composition of the surface layers. The developed nano-component coatings of Fe–Ti–SiC–MgC2 showed high antifriction characteristics in the entire load-velocity range, simulating the operation of the friction unit in real conditions. It is shown that the means of controlling wear and ensuring high performance is the presence of both a thin film layer of graphite and the formation of fine secondary structures. This provides the modification of the friction surface and protects against unacceptable plastic deformation processes. [ABSTRACT FROM AUTHOR]

Hydrodynamics and mass transfer in regular film apparatuses containing flat irrigated channels with a laminar flow of gas and liquid as the principal element are studied. The problem is solved by the approximate method, which makes it possible to drastically decrease the amount of the required calculations. It is proven that it is sufficient to determine the dimensionless flux as the function of dimensionless length in a restricted domain of parameters. Approximations are permissible outside the bounds of this domain: in some cases the changes of concentrations in phases along the crosswise direction can be neglected and, in other instances, the concentration changes can be neglected in the whole active mass-transfer region; i.e., diffusion layers exist in one or another phase before the estimation of concentration equilibrium in the system. Finally, the mass transfer resistance is concentrated in liquid or gas; there are parameter spaces where the change of concentration in one of the phases in a crosswise direction can be neglected, while another one contains diffusion boundary layers. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The recovery of hydrogen from binary gas mixtures with active (deactivating the surface of the membrane) and passive impurities has been studied. Experiments have been carried out on a multifunctional membrane module, the operating area of which consists of gas chambers separated by a thin foil palladium membrane. A dimensionless coefficient of the deactivation of the surface of the membrane has been introduced. An analytical formula has been obtained for the hydrogen flux from binary mixtures at its preset pressures on the opposite sides of the membrane that takes into account adsorption-desorption, breaking to protons on the surface, the diffusion of the latter in the metal lattice, and the recombination of Н+. In the case when the condition are fulfilled, the Н2 flux can be calculated by the modifiable Sieverts equation. This equation and an assumption about the complete mixing of the mixtures in the chambers of the membrane module have made it possible to develop a theoretical model for the recovery of hydrogen from binary mixtures in the membrane module. An analytical dependence for the Н2 flux as a function of the fluxes of the mixtures at the inlet of the chambers, ratio of the pressures on the opposite sides of the membrane, initial composition of the hydrogen mixture, and the coefficient of deactivation has been found. Utilizing this dependence, a procedure for finding this coefficient using additional experiments has been proposed. As an example, the coefficients of deactivation for the products of steam reforming of methane (CO, СО2, СН4, and water vapor) have been calculated for a palladium membrane with a composition Pd-6%Ru. The theoretical model has been subjected to the experimental verification on Н2-5%CO and Н2-20%CO binary mixtures. [ABSTRACT FROM AUTHOR]

The hydrogen permeability of membranes made of silver-free palladium alloys with compositions of Pd-In(6%)-Ru(0.5%), Pd-In(6%), Pd-Ru(6%), and Pd-Ru(10%) has been studied on an experimental unit, a multifunctional membrane module, the key element of which is a palladium foil positioned between the chambers for the supply (retentate) and removal (permeate) of a gas mixture. The applicability of the Sieverts equation to these systems has been experimentally proved, and the activation energies and preexponential factors for the corresponding equation have been found. It has been shown that the hydrogen permeability of the studied membranes increases by several times compared to conventional palladium membranes. A theoretical model for the transport of hydrogen through the membrane module in the absence of a pressure differential in the upper and lower chambers and arbitrary compositions of the gas mixtures under separation has been proposed. The experiments carried out within a wide range of variations in the rates of the gas in the chambers have shown the applicability of the proposed model. [ABSTRACT FROM AUTHOR]

The results of tests of a Zr-Al-B boundary friction detonation coating in a wide range of changes under friction conditions have been presented. A comparative analysis of the obtained characteristics of friction and wear in order to evaluate the tribotechnical properties of amorphous-crystalline coatings has been carried out. These results have been compared with parallel tests of coatings based on tungsten carbide, samples of hardened steel and bronze, and the bearing of the sliding layer. The formation of solid solutions has been established and the introduction of oxygen in zirconium that corresponds to the formation on the friction surfaces of the secondary structures of the first type, a characteristic feature of which is their surface localization, ultra-dispersed structure, and ability to minimize disruption and shield unacceptable adhesion phenomena. The use of the Auger electron microscope confirmed that oxygen completely replaces the sulfur in the surface structures. [ABSTRACT FROM AUTHOR]

The influence of the thickness of a Pd-Ru alloy membrane on the H flux from binary mixtures containing about 5 and 20% CO, CO, CH, and steam has been studied. It has been shown that with a decrease in the membrane thickness from 30 to 10 μm, the negative influence of these impurities on the H flux increases. In experiments with pure H, it has been established that a decrease in the membrane thickness does not affect the nature of the rate-limiting step in the H flow mechanism. The values for the effective activation energy of the H permeability of the 30- and 10-μm membranes are 13.6 and 23.4 kJ/mol, respectively. A mathematical model describing the flow of hydrogen from binary mixtures through membranes of various thicknesses with varying temperature and pressure is proposed. [ABSTRACT FROM AUTHOR]

Aims To optimize the DNA isolation for the routine detection and quantification of bacillary spores in soil and swabs. The procedure is primarily intended for diagnostics of Bacillus anthracis spores, but due to its high pathogenicity, B. thuringiensis served as its surrogate organism. Methods and Results Various commercial kits for soils and swabs in combination with quantitative PCR were tested with different results. The PowerSoil DNA kit and the Ultra Clean Microbial DNA kit gave the best results for the extraction from soil and swabs, respectively. Extra beating led to considerably higher yields of DNA. The effectiveness of isolation reached 23% for DNA isolation from soil and 13% from swabs. The limit of detection was assessed to be 8·85 × 103 from 250 mg of soil and 2·79 × 103 from a swab inoculated with 100 μl of spore suspension. Conclusions The optimized protocol is suitable for direct isolation and quantification of bacillary spores without any previous culturing. Significance and Impact of the Study In contrast to previous studies, the isolation and quantification of spores was performed directly from the sample, without previous culture of spores on plates. Therefore, the method is suitable for such conditions where previous culturing is not possible, such as in military installations under field conditions. [ABSTRACT FROM AUTHOR]

Detonation amorphous-crystalline coatings Zr-Si-B that additionally contain solid lubricant additive as an anti-friction component in the form of the dispersed molybdenum disulfide have been developed. The high wear resistance of coatings that contain molybdenum disulfide has been noted. In a study of the surface layer, photomicrographs of friction surfaces on which activation processes take place have been used in electron diffraction analysis. The wear resistance of the coatings has been established, which enabled the creation of separating juvenile thin film surface of an object that represented the product of oxygen-free structures based on chemical elements of intermetallic phases included in the coating composition. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of sodium humate (HNa), applied to feed or drinking water as a partial substitution for pharmacological doses of ZnO, on clinical, biochemical and haematological indicators of health status, oxidative stress and the serum fatty acid (FA) profile in weaned piglets. Weaned piglets (32) were allocated into four groups: Control = basal diet containing 110 mg ZnO/kg; ZnO 2.5 = pharmacological dose of ZnO (2.5 g ZnO/kg); ZnO 1.7 + HNa (f) = 1.7 g ZnO and 20.0 g HNa/kg; ZnO 1.7 + HNa (w) = 1.7 g ZnO/kg and drinking water with 0.2% HNa. All ZnO treatments resulted in good performance and clinical health of piglets in contrast to Control, which contained three diarrhoeic piglets. Increased triacylglycerols in the ZnO 2.5 and ZnO 1.7 + HNa (w) groups in comparison with Control suggested increased energy metabolism after treatments. Neither total cholesterol, nor HDL and LDL were affected by treatments. Piglets treated with ZnO and HNa had (ZnO 1.7 + HNa (w)) or tended to have (ZnO 1.7 + HNa (f)) lower urea in serum. Significantly (in ZnO 2.5 and ZnO 1.7 + HNa (f)) or non-significantly (ZnO 1.7 + HNa (w)) higher haematocrit and haemoglobin levels were detected in the blood of treated piglets. Long-term ZnO 2.5 treatment significantly increased serum 8-iso-PGF2α the most reliable biomarker of oxidative stress. Partial substitution of ZnO by HNa positively affected the oxidative status of piglets as evidenced by significant (ZnO 1.7 + HNa (w)) or non-significant (ZnO 1.7 + HNa (f)) declines in serum 8-iso-PGF2α . ZnO 2.5 treatment significantly decreased saturated (SFA), monounsaturated (MUFA) and n-3 polyunsaturated FA (PUFA) and increased PUFA n-6 and n-6/n-3 ratios in serum compared to Control. The synthesis of some physiologically significant long-chain PUFA (LC-PUFA), namely n-6 dihomo-γ-linolenic acid and n-3 eicosapentaenoic, docosapen-taenoic was negatively affected by ZnO 2.5 treatment. Both ZnO 1.7 + HNa (f )/(w) treatments significantly increased the proportion of SFA and PUFA n-3 and decreased PUFA n-6 and n-6/n-3 ratios in comparison with ZnO 2.5 and the effect was more considerable in ZnO 1.7 + HNa (w). Most individual PUFA n-3 and n-6 as well as the n-6/n-3 ratio in both treatments were similar to Control. The results indicate that the partial substitution of ZnO by HNa can benefit performance and health of weaned piglets to a similar extent as a high pharmacological dose of ZnO, whereas it can decrease the oxidative stress induced by prolonged over-supplementation of ZnO. Additionally, such a treatment can eliminate the unfavourable effect of high ZnO doses on the n-6/n-3 ratio and the proportion of some physiologically significant LC-PUFA in serum. Generally, it can be concluded that the effects of feed and water HNa supplementation are similar, but are more pronounced when HNa is applied to drinking water. [ABSTRACT FROM AUTHOR]

Copyright of Eastern-European Journal of Enterprise Technologies is the property of PC TECHNOLOGY CENTER and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Geomagnetic records from 20 Japanese observatories have been used to yield time series of response function (RF) components for 20 years at periods of between 2.5 and 60 min. Six observatories showed anomalous variations lasting 3-5 years in the short period part of the above range of periods prior to the March 11, 2011 Tohoku earthquake. The variations could have been intermediate-term precursors. We made a detailed analysis of how noise affects the results using coherence criteria, visual control, and the remote-reference technique. We clarified the conditions that make response functions dependent on geomagnetic activity. For 19 observatories we constructed the tensor of the anomalous magnetic field with Kakioka as the base site. An anomaly in electrical conductivity striking WNW-ESE has been identified beneath the Boso Peninsula near Tokyo in the conditions of strong noise. We sought to corroborate the reality of the anomaly by visual control and processing of nighttime records with minimum noise. We advanced idea that precursors can be monitored using the DC noise field in the presence of a shallow conductivity anomaly. We provided a tectonic interpretation of the obtained RF anomalies. The Boso conductivity anomaly is interpreted as being due to a graben-shaped structure of the sediments and possibly to a deeper plate-tectonics structure, that is, the Sagami Trough. We examine similarities and differences between the Boso anomaly and the Avacha anomaly in Kamchatka, and provided recommendations for further study of the Boso anomaly and for using the Avacha anomaly to monitor EM precursors in Kamchatka. [ABSTRACT FROM AUTHOR]

The H flow rate through the 30-μm thick foil from Pd-Ru(6%) and Pd-Ru(10%) alloys at 673 and 773 K was found to be controlled by the diffusion of H atoms in the foil bulk. The interrelation between hydrogen permeability through the Pd-In(6%)-Ru(0.5%), Pd-Ru(10%), Pd-Ru(6%), and Pd-Ag(23%) membranes and the permeability pre-exponential factors in the Sieverts equation in the 573-773 K temperature interval indicated that the hydrogen permeability depended on the structural characteristics of palladium alloys. The influence of the CO, CH, and water vapor impurities on the H flow rate through the studied membranes depended on the driving force nature (the sweep gas or transmembrane pressure) used for the development of the partial hydrogen pressure difference across the membrane. The negative influence of CH and CO was observed only when using a transmembrane pressure and at the impurity content of 20% or more. This effect increased with increasing temperature in the 573-773 K range, with the influence of CO being more pronounced due to its reaction with hydrogen leading to the formation of CO. The influence of water vapor was studied at its 11-23% content in hydrogen and at 573 and 773 K of temperature. The negative influence of water vapor was found to subside as its content in the hydrogen mixture decreased and the temperature increased. It was shown that water vapor can be used as a sweep gas and at T = 773 K its influence on the H flow rate through the membrane was almost the same as that of N. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The hydrodynamics and two-phase mass exchange in packed film devices were studied for the cocurrent laminar flow of a gas and a liquid. The mass-transfer problem was solved by the approximate Galerkin method. Two known absorption factors were selected as crucial parameters. The analytical solution was found within a limited absorption plane. Outside this region, the solutions were simplified, and the dimensionless flows became one-parameter length functions. In particular, the conditions under which the resistance to mass transfer was concentrated in a given phase and corresponding flows became independent of the absorption factors were found. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) serve as low-costing alternatives to silicon solar cells because of their low material and fabrication costs. Usually, they utilize Pt as the counter electrode (CE) to catalyze the iodine redox couple and to complete the electric circuit. Given that Pt is a rare and expensive metal, various carbon materials have been intensively investigated because of their low costs, high surface areas, excellent electrochemical stabilities, reasonable electrochemical activities, and high corrosion resistances. In this feature article, we provide an overview of recent studies on the electrochemical properties and photovoltaic performances of carbon-based CEs (e.g., activated carbon, nanosized carbon, carbon black, graphene, graphite, carbon nanotubes, and composite carbon). We focus on scientific challenges associated with each material and highlight recent advances achieved in overcoming these obstacles. Finally, we discuss possible future directions for this field of research aimed at obtaining highly efficient DSSCs. [ABSTRACT FROM AUTHOR]

Paratuberculosis, caused by Mycobacterium avium subsp. paratuberculosis ( Map), is a chronic incurable infection of intestinal tract of animals. Molecular characterization of Map isolates classifies them into two major groups, ' Cattle' or Type II and ' Sheep' or Type I/ III with a different phenotype, epidemiology, virulence and pathogenesis. The aim of this study was to examine 192 Map ELISA-positive sheep and goats from Cyprus using faecal culture and genotype Map isolates using IS 1311 PCR and restriction endonuclease analysis ( IS 1311 PCR- REA) with Hinf I restriction enzyme. Map was isolated from only four (4.6%) faecal samples out of 88 sheep and 15 (14.4%) faecal samples out of 104 goats. Genotyping of the isolates using IS 1311 PCR- REA revealed that sheep and goat populations on the island are infected primarily by ' Sheep' strains. Only three Map isolates from goats originated from one farm were characterized as ' Cattle' strains. [ABSTRACT FROM AUTHOR]

Experimental data are presented and a mathematical model is suggested for hydrogen transport through a palladium membrane module. The basic working element of the module is a piece of palladium foil secured between two pieces of fine-mesh metallic gauze to prevent the rupture of the foil because of the difference between the outer pressures applied. It is demonstrated that, under the experimental conditions considered, the effect of the supporting metallic gauzes can be neglected. An expression is reported for the hydrogen flux through the foil as a function of the foil thickness and applied pressures. In the particular case of fairly high pressures, the hydrogen flux obeys the well-known Sieverts law, being limited by proton diffusion in the palladium lattice. At low pressures, the hydrogen flux is limited by adsorption-desorption processes on the foil surface. The preexponential factor in the Sieverts law for pure palladium membranes has been refined on the basis of experimental data for the membrane module. [ABSTRACT FROM AUTHOR]

Antibiotic resistant bacteria can be easily isolated from the faeces of cattle, pigs or poultry. However, whether the production of different farm animals is associated with a higher or lower prevalence of antibiotic resistance is not clear. In this study we therefore used real time PCR for the quantification of antibiotic gene prevalence in the DNA purified from the faeces of farm animals. First we showed that experimental streptomycin therapy of 12-week-old chickens and 46-week-old hens significantly increased the relative prevalence of strA and sul2 genes though this did not necessarily indicate an absolute increase of strA-encoding bacteria. Next we quantified antibiotic gene prevalence in the DNA purified from the faeces of cattle, pigs and laying hens. The lowest prevalence of strA, aadA, sul1, sul2, tet(A), tet(B), tet(G) and cat genes was recorded in the intestinal contents of laying hens. In cattle and pig faecal samples, an intermediate prevalence of antibiotic resistance genes was observed with strA and sul2 dominating by two logs over the remaining six tested genes. The differences in strA and sul2 prevalence between cattle and pig microbiota were not significant whilst the prevalence of strA and sul2 in laying hen microbiota was significantly lower than in the other two species. Cattle and pig production systems may therefore represent a more important reservoir of antibiotic resistant bacteria than laying hens. [ABSTRACT FROM AUTHOR]

The License Plate (LP) localization plays an important role in License Plate recognition system in some countries which have enormous variety of LPs such as Malaysia. In Malaysia, the LPs have extraordinary diversities in fonts, shapes and even using handwritten fonts in LPs and so on. Moreover, since this paper works on LP at the back of the cars, the presence of LP font on the body of car can also adds a major complication for LP recognition systems. In this paper, a new License Plate Localization algorithm is proposed for Malaysia LPs by Otsu method. The empirically results present a new threshold of Blob Analysis to extract LP location. Additionally, the new thresholds are introduced for Morphological Opening Operator and objects labeling. At the end, the LP localization is concluded by new boundaries limitations which demonstrate exactly LP location in image. These new thresholds cause LP localization system gain 90% accuracy while it is higher than any other existence methods that are showed real result for Malaysian LPs localization. These results were obtained from entirely experimental works on LPs different shape and fonts of LPs in natural environment conditions such as raining, light reflection and so on. [ABSTRACT FROM AUTHOR]

A survey of the occurrence of mycobacteria was conducted from 717 freshwater fish (25 species) in two water reservoirs, five ponds and two farms in the Czech Republic. A total of 2182 tissue samples from these fish were examined using the conventional culture method. Thirteen mycobacterial isolates were obtained from 12 (1.7%) fish belonging to nine species. Isolates were identified using sequence analysis of the 16S rRNA gene as: Mycobacterium algericum, M. fortuitum, M. gordonae, M. insubricum, M. kumamotonense, M. nonchromogenicum, two isolates of M. peregrinum, M. terrae and M. triplex. Mycobacteria were isolated more frequently from fish skin and gills than from internal organs or muscles. [ABSTRACT FROM AUTHOR]

The occurrence of staphylococci and enterococci expressing increased resistance to erythromycin (ERY) and, in particular, to macrolide-lincosamide-streptogramin B (MLSB) antibiotics was investigated in dairy cattle, pigs and turkeys. Three hundred rectal (cloacal) swabs of each animal species were examined. A total of 120 and 71 staphylococci and enterococci, respectively, with increased resistance to ERY were identified. These were most frequent in turkeys (42.3% of positive animals), followed by pigs and dairy cattle (6.7% and 6.0% of positive animals, respectively). Similarly, MLSB-resistant isolates colonized predominantly turkeys (29.7% of animals), while their occurrence in pigs and dairy cattle was only sporadic (0.8% of animals). At least one of the erm genes encoding for MLSB resistance was found in 56.7% and 69.0% of staphylococci and enterococci, respectively. The erm(C) gene prevailed in staphylococci while the erm(B) gene was predominant in enterococci. Macrolide efflux genes msr(A) and msr(C) were also frequent in staphylococci and enterococci, respectively. Macrolide inactivation gene mph(C) occurred mainly in staphylococci. In staphylococci, methicillin resistance was rarely detected (7.5% of isolates), but resistance to telithromycin (ketolides) was frequent in both staphylococci and enterococci (89.2% and 47.9% of isolates, respectively). This study showed that turkeys represent an important source of ERY (MLSB)-resistant cocci. In addition, resistance to ketolides was also frequent. [ABSTRACT FROM AUTHOR]

The vacuum desorption of gases from inorganic solvents with low and high boiling points is reported. A thin-film evaporator consisting of regular tubular packing elements is considered. A laminar downward cocurrent flow of liquid and vapor is analyzed. General theoretical propositions are illustrated by the example of the desorption of simple gases from lower alcohols (methanol, ethanol) and liquid naphthalene, as well as by the example of removing the products of ester decomposition from esters at high temperatures. [ABSTRACT FROM AUTHOR]

The optimal conditions for the vacuum desorption of components from liquid solutions are found-the maximum pressure and minimum acceptable density of irrigation. The evaporative equipment is modern regular film tubular nozzles. The laminar pressure of liquid and vapor in the downstream parallel flow mode is assumed. The vacuum desorption from water solutions of some inorganic gases that have both low and high solubility is considered as an application to the theory. [ABSTRACT FROM AUTHOR]

Geographically related Staphylococcus epidermidis isolates from human patients (n=30), dairy farms (farmers and individual raw milk from cattle, n=36) and a dairy plant (n=55) were examined for epidemiological relatedness by pulsed-field gel electrophoresis and, using in vitro methods, for the ability to produce biofilm and antimicrobial resistance. Methicillin-resistant isolates (MRSE) were also identified and characterized. Isolates from farmers and dairy cattle were found to be genetically related, while isolates from human patients were highly diverse. Some dairy plant isolates (18.2%) were closely related to those from dairy farms. Biofilm production and resistance to antimicrobial agents were most typical for isolates from human patients, of which 76.7% were MRSE. Methicillin resistance was also widespread in farm-related isolates (61.1%). This study indicates the possible transmission of S. epidermidis between cattle and farmers. Dairy products were not proven to be an important source of either human infections or methicillin-resistant strains. [ABSTRACT FROM AUTHOR]

A theoretical study of hydrocarbon dehydrogenation in state-of-the-art packed tubular membrane reactors and in impermeable tubes is performed. Conditions of the efficient operation of apparatuses are found under which a high degree of hydrocarbon conversion and yields of products are attained. The possibility of experimentally determining a number of constants for the such processes is shown. Results of theoretical calculations are compared to experimental data for isobutane dehydrogenation. [ABSTRACT FROM AUTHOR]

The review is devoted to synthesis and study of interfacial properties of electrostatic complexes between oppositely charged chitin derivatives and surfactants, so-called surfactant-polyelectrolyte complexes (SPECs). The ordered nanostructure of insoluble SPEC found by small-angle X-ray scattering (SAXS) looks as a physical gel network formed by micelle-like aggregates interconnected by macro-molecular chains. Viscoelastic properties of such gels were studied by means of the Hertz method and interfacial dilational rheology. A new method based on the effect of diffusion-enhanced gelation at the interface of aqueous solutions of oppositely charged polyelectrolytes and surfactants was developed. This method makes it possible to produce microcapsules containing enzymes, i.e. microreactors for enzymatic catalysis. [ABSTRACT FROM AUTHOR]

A review of the amphiphilic derivatives of chitin, obtained by covalent grafting of hydrophilic and hydrophobic radicals, is given. It is shown that water-soluble alkylated derivatives of chitin and chitosan, as well as surfactant-polyelectrolyte complexes between oppositely charged surfactants, exhibit interfacial activity, forming structured (gel-like) adsorption layers (AL). Gel formation inside AL of chitin derivatives is characterized by means of interfacial dilational rheometry. [ABSTRACT FROM AUTHOR]

Mass transfer with solvent evaporation in the vapor-liquid two-phase film evaporators used for the removal of undesirable impurities from liquid solutions at low pressure is studied. The average concentrations of solution components in the falling liquid film are determined. The most efficient operating conditions for impurity removal, in which the resistance to mass transfer is concentrated in the liquid phase, are found. [ABSTRACT FROM AUTHOR]

Low molecular weight chitosans (5 kDa) hydrophobically modified with 3, 10, and 18 mol % of tetradecenoyl (TDC) groups have been synthesized. Their good solubility at neutral pH, their surface activity and micelle-forming properties as well as their ability to interact with negatively charged phospholipid vesicles mimicking the internal layer of cell plasma membranes, allow us to consider them as potential non-viral transfection vectors for gene therapy. [ABSTRACT FROM AUTHOR]

Copyright of Aviation (1648-7788) is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Aviation (1648-7788) is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Aviation (1648-7788) is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Aviation (1648-7788) is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Aviation (1648-7788) is the property of Vilnius Gediminas Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The kinetics of absorption of inorganic gases by aqueous solutions of some salts, primary amines, and ammonia in a number of practically important cases is reduced to the kinetics observed during absorption of these gases by solutions of acids and bases. Problems of unsteady-state absorption and release of inorganic gases from the aforementioned aqueous solutions are considered using the example of two stagnant media (a liquid and a gas). [ABSTRACT FROM AUTHOR]

An X-ray diffractometer with a mobile emitter-detector system is able to perform various X-ray examinations of a stationary sample. The design for this instrument is described, along with its operating principles and control programs. Owing to its high-precision angular movement sensors and its two detectors (one of these, a linear position-sensitive detector, has a working length of 100 mm and a resolution of <0.2 mm), the diffractometer can be used in both traditional and nontraditional experiments on X-ray reflection, scattering, and absorption. Results from using this instrument in reflectometry and X-ray tomography are presented as an example. [ABSTRACT FROM AUTHOR]