A new empirical model for quiescent annealing of binary co-continuous polymer blends

The high sensitivity of the morphology and final properties of co-continuous polymer blends to thermal annealing has motivated many researchers to study the evolution of their morphology during thermal annealing process. In this work, phase coarsening of a low interfacial tension polylactic acid/polycaprolactone blend and a medium interfacial tension polylactic acid/polyethylene blend during quiescent annealing was studied in detail. To this aim, characteristic length scale of the microstructure of the polymer blends was determined at different annealing times. It was found that the phase size in both blends increased linearly by time at the early stage of the annealing and then the phase coarsening rate gradually decreased at longer times. Finally, the phase size of the blends approached a finite size. The mechanisms involved in the observed phase coarsening behavior were discussed in detail. Linear and exponential phase coarsening models in the literature could not explain the observed phase coarsening behavior in the studied blends. A new empirical model was presented which showed a very good agreement with both the obtained results in this work and the previous experimental data in the literature. The obtained results indicate the significant potential of the new model in analyzing phase coarsening behavior of co-continuous polymer blends.

     

A study of protein clearances in patients with nephrotic syndrome

In 37 patients of nephrotic syndrome, serum protein levels, protein fractions and urinary levels of proteins and their fractions were determined. The findings of serum levels of proteins and their fractions were compared with an equal number of age and sex matched controls. Twenty three patients showed selective and 14 non-selective proteinuria. Most of the patients with selective proteinuria showed good response to steroids therapy while those with non-selective proteinuria did not respond.     

Mathematical modelling of ball and plate system with experimental and correlation function-basedmodel validation

The ball and plate system is an inherently nonlinear under actuated benchmark system used for validating the performance of various control schemes. A mathematical model depicting the dynamics close to that of the system is very much required for such a test bed. In this correspondence, the complete nonlinear model, a simplified nonlinear model, and a linearized model of the ball and plate system are developed. The system comprises a ball and plate mechanism and a rotary servo unit. The ball and plate mechanism is modelled using the Euler–Lagrange method, whereas the rotary servo subsystem is modelled from the first principles. The nonlinear model of the combined system is developed by including the dynamics of the servo motor with gear and rolling resistance between the ball and the plate. The simplified nonlinear model of the system is obtained with suitable assumptions. The model is linearized around the operating point using the Jacobian. The validity of the developed models is investigated through correlation function analysis. The open-loop response of the three models, viz., nonlinear, simplified nonlinear, and linearized models, is analyzed in the MATLAB/Simulink platform. Since the open-loop system is unstable, the experimental validation of the model is performed with a double-loop PSO (particle swarm optimization) PID control scheme.     

The efficiency of technical retrofitting of cogeneration stations using combined-cycle plants

We consider the problem of technical retrofitting of gas-and-oil fired steam-turbine cogeneration stations by converting them into combined-cycle plants as a component of the strategic development of Russia’s electric power industry. The initial statements, methodology, and results obtained from solving the problem are described.     

A global survey of effects of genotype and environment on selenium concentration in lentils (Lens culinaris L.): Implications for nutritional fortification strategies

Lentils (Lens culinaris L.) are an important protein and carbohydrate food, rich in essential dietary components and trace elements. Selenium (Se) is an essential micronutrient for human health. For adults, 55 μg of daily Se intake is recommended for better health and cancer prevention. Millions of people around the world have Se-deficient diets and biofortification may be an effective solution. The total Se concentration of lentils grown in six major lentil-producing countries were analysed to determine the potential for Se biofortification in these regions. The highest Se concentrations based on location means were found in lentils from Nepal (180 μg/kg) and southern Australia (148 μg/kg) while the lowest were those from Syria (22 μg/kg), Morocco (28 μg/kg), northwestern USA (26 μg/kg), and Turkey (47 μg/kg). Significant location effects within a country were observed for Nepal and Australia. All values were lower than previous published data for Saskatchewan grown lentils (425–672 μg/kg). Lentils originating from Australia, Nepal, or Canada could be considered good sources of Se, as consumption of 50 g would provide 13–61% of the recommended dietary allowance (RDA). Our findings indicate lentil may be appropriate as a target crop for Se biofortification and investigated as a food-based solution for populations with Se deficiencies.     

醋酸稀溶液的络合萃取

络合萃取法对于极性有机物稀溶液的分离具有高效性和高选择性。本文以醋酸稀溶液为分离对象,通过系统的相平衡实验筛选出30 wt％三辛胺(或7301)+20 wt％正辛醇+50 wt％煤油混合溶剂。同时,探讨了叔胺类萃取剂对醋酸萃取的过程机理,研究了混合溶剂萃取稀醋酸工艺的可行性。     

Improving the processing of steelmaking waste. Part 2. Development of the basic processing system

The expediency of reducing steelmaking slags to obtain metallic and oxide phases for use in metallurgy and construction is studied experimentally. Slag from the tailings at Zlatoust Metallurgical Plant is investigated. Experiments are conducted on the reduction of slag samples by carbon. The composition of the experimental samples is determined by X-ray spectral microanalysis. Experimental and theoretical data indicate that 20% (or even more) of the initial slag mass may be converted to metal by reduction. Practically complete reduction of the iron in the slag is possible. Significant proportions of the chromium, nickel, manganese, and other valuable components may pass to the metallic phase. Reduction of the liquid slag is expedient at 1500°C or more, so as to extract the metals more completely and form a consolidated metal phase. Preliminary solid-phase reduction of the slag at 1100–1200°C is found to be expedient. This process converts much of the iron present as oxides in the slag to a form susceptible to magnetic separation. Subsequent magnetic separation allows the fraction with an elevated content of valuable metals to be extracted from the oxide phase, which has a low metal content. The oxide fraction may be used in construction materials. In the design of systems based on these principles, utilization of the large quantities of carbon monoxide and metal vapor in the gas phase is recommended. One possibility is to use the carbon monoxide for preliminary solid-phase reduction of the slag. This research permits the development of an efficient system for processing slag tailings.     

Concept of building an aggregation kinetic model taking into consideration the dependence between aggregation activity and cluster ages

A concept and an approach based on this concept for constructing kinetic models of binary aggregation that take into account the impact of the age of clusters of any order on their aggregation activity have been proposed. The classical Smoluchowski and Becker–Döring models have been modified.     

Kinetics of the steady-state evaporation of single-component liquids into an inert gas

The effect of a driving force on steady-state evaporation in open and closed systems is studied.