Numerical modeling of multiphase fluid flow through the electrolytic cell

Electrolytic cells are used to obtain sodium hypochlorite (NaOCl), an important industrial product, from seawater. The chemical reaction of the process (NaCl + H2O → NaOCl + H2) produces hydrogen gas bubbles near the cathode\u27s surface inside a continuous liquid phase. In time, solid particles of calcium carbonate appear on the cell\u27s anode due to the cell operation. Thus, the fluid flow process in the cell, in general, is a three-phase process that includes turbulence. Although hydrogen bubbles and calcium carbonate particles are usually small in size, they aggregate in the system over time and lead to the blockage of the active area of the electrodes, which lowers the efficiency of the cell. It is important to understand where the regions with high concentration of hydrogen bubbles and solid particles inside the cell are located, and to design an optimally shaped electrolytic device. (Abstract shortened by UMI.)

Thermal transport eveluations related to waste package design -- model evaluations -- task 19

The purpose of the “Thermal Transport Evaluations Related to Waste Package Design” Task # 19 of Cooperative Agreement Number DE-FC28-98NV12081 was to develop a new CFDHT model for heat transfer and fluid flow in the potential rsepository at the Yucca Mountain, Nevada and to study the effects of forced convection during the pre-closure period and natural convection during the postclosure period. The analysis was performed for the drift dimensions shown in Figure 4-1 below. The intended use of the model is to estimate the velocity and temperature distribution as well as the highest temperature in the drift during the pre-closure and post-closure periods. The validation of the model is documented in section 6 of this report. The analysis was performed using both STAR-CD v. 3.150 and CFDHT v. 1.0, which are qualified software. The final result is the maximum temperature value in the drift during the pre-closure and post-closure period and the velocity and temperature distribution around the canisters

A self consistent chemically stratified atmosphere model for the roAp star 10 Aquilae

Context: Chemically peculiar A type (Ap) stars are a subgroup of the CP2 stars which exhibit anomalous overabundances of numerous elements, e.g. Fe, Cr, Sr and rare earth elements. The pulsating subgroup of the Ap stars, the roAp stars, present ideal laboratories to observe and model pulsational signatures as well as the interplay of the pulsations with strong magnetic fields and vertical abundance gradients. Aims: Based on high resolution spectroscopic observations and observed stellar energy distributions we construct a self consistent model atmosphere, that accounts for modulations of the temperature-pressure structure caused by vertical abundance gradients, for the roAp star 10 Aquilae (HD 176232). We demonstrate that such an analysis can be used to determine precisely the fundamental atmospheric parameters required for pulsation modelling. Methods: Average abundances were derived for 56 species. For Mg, Si, Ca, Cr, Fe, Co, Sr, Pr, and Nd vertical stratification profiles were empirically derived using the ddafit minimization routine together with the magnetic spectrum synthesis code synthmag. Model atmospheres were computed with the LLModels code which accounts for the individual abundances and stratification of chemical elements. Results: For the final model atmosphere Teff=7550 K and log g=3.8 were adopted. While Mg, Si, Co and Cr exhibit steep abundance gradients Ca, Fe and Sr showed much wider abundance gradients between log tau_5000=-1.5 and 0.5. Elements Mg and Co were found to be the least stratified, while Ca and Sr showed strong depth variations in abundance of up to ~ 6 dex.Comment: 9 pages, 15 figure

Experimental investigation and modeling through using the solution-diffusion concept of pervaporation dehydration of ethanol and isopropanol by ceramic membranes HybSi

© 2016Results of experimental investigation of pervaporation dehydration of ethanol and isopropanol by HybSi membranes at concentrations of organic component in the feed in the range from ~50 to ~99 wt%, feed temperatures 60, 70 and 80 °C and permeate pressures 5 and 20 mm Hg are presented. The experimental data demonstrate a nonmonotonic dependence of separation factor on water concentration in the feed with maximum value of separation factor reached at water concentration in the feed of several percent for both ethanol dehydration and isopropanol dehydration. Values of both total permeate flux and separation factor for the isopropanol dehydration case are higher than for the ethanol dehydration case. Results of the experimental investigation are compared with similar results of other researchers obtained for pervaporation dehydration of ethanol and isopropanol by membranes coated with a selective layer made of silica-based and zeolite-based materials. Based on the “solution-diffusion” concept, a mathematical model is developed for the pervaporation process, which includes three parameters, two of which are permeability coefficients for pure components and the third parameter defines “active pores fraction”. Use of the model can lead to essential reduction of the number of pervaporation experiments needed for designing a pervaporation pilot plant as well as assist in determining optimum operating conditions of the pervaporation process. Results of calculations carried out with use of the proposed model are compared versus results of experimental investigation of pervaporation dehydration of ethanol and isopropanol by HybSi membranes, pervaporation dehydration of glycerin by HybSi membranes (of other researchers) and pervaporation dehydration of ethanol by NaA zeolite-based membranes (of other researchers). Results of calculations agree reasonably well with all considered experimental data. Additionally, the model allows determining the optimum thickness of the selective layer of HybSi membranes

Formation of names of medicines on the basis of anatomical formations

The article describes drugs containing anatomical information. As a result of the analysis, term elements of Greek and Latin origin were identified in their composition. Most of these word-formation segments form the main therapeutic groups of drugs. Greek and Latin term elements are presented in a large number of drugs and are implemented in various combinations.В статье описываются лекарственные средства, содержащие информацию анатомического характера. В результате анализа в их составе были выявлены терминоэлементы греческого и латинского происхождения. Большинство указанных словообразовательных отрезков формируют основные терапевтические группы лекарственных средств. Греко-латинские терминоэлементы представлены в большом количестве лекарственных средств и реализуются в различных комбинациях

Radiodiagnosis of child's gastrointestinal tract functional changes resulted from labor injuries to vertebral column and spinal cord

Available from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Лікування білатеральних переломів стегнових кісток апаратами зовнішньої фіксації

The article describes experience of treatment of 20 patients having bilateral fractures of their lower extremities with rod and pin-rod external fixing devices. Within 3 years of follow-up, excellent results were achieved in 16 cases, good in 3, and satisfactory in 1. The use of a rod device for bilateral fractures of the femur in its upper and middle one-third part turned out to be the most optimum.Представлен опыт лечения 20 больных с билатеральными переломами нижних конечностей с использованием стержневых и спицестержневых аппаратов внешней фиксации. На сроках до 3 лет отличные результаты получены у 16, хорошие — у 3, удовлетворительные — у 1 больного. Наиболее оптимальным оказалось использование стержневого аппарата при билатеральных переломах бедренной кости в верхней и средней третях.Представлено досвід лікування 20 хворих з білатеральними переломами нижніх кінцівок із використанням стрижневих і спицестрижневих апаратів зовнішньої фіксації. У терміни до 3 років відмінні результати отримані у 16, хороші — у 3, задовільні — у 1 хворого. Найоптимальнішим виявилося використання стрижневого апарата в разі білатеральних переломів стегнової кістки у верхній і середній третинах

An improved numerical model for calculations of transport and size distributions of atmospheric aerosols and cloud droplets

Aerosols and cloud droplets in the atmosphere appear in different sizes. They can be transported by wind and experience various microphysical changes due to nucleation, collisional and condensational growth, evaporation and sedimentation. These microphysical processes affect optical properties of clouds and aerosols, and through it, they affect climate. Climate models usually lack a microphysical module, but instead use various parameterizations to represent clouds in the terrestrial atmosphere. Coupling between cloud microphysical models and climate models could improve the quality of numerical predictions of climate. In this study, CARMA (Community Aerosol and Radiation Model for Atmospheres), which is one of the best available microphysical models for calculation of size distributions of atmospheric aerosols and cloud droplets based on environmental conditions, has been redesigned and rewritten for coupling with numerical models of climate. In the revised model, data transfer between subroutines is handled via lists of arguments. The microphysical part of CARMA v. 2.2 was isolated from other processes, such as radiation and transport, and prepared for coupling with existing climate models. Changes were made to the vertical transport subroutines. The PPM (Piecewise Parabolic Method) method of solving the advection equation was replaced with the REA (Reconstruct-Evolve-Average) method, complemented with the minmod slope limiter. The sedimentation equation is now solved using the upwind method. Sedimentation fluxes, used by the upwind method, are calculated inside the microphysical part of CARMA. The ability of the revised CARMA model to reproduce the observed microstructure of a marine stratocumulus cloud over the North Sea was tested. The improved model closely reproduces most of the observed properties of the cloud and aerosols.M.S.Includes bibliographical references (p. 102-104)

Physical education classes with distance learning as a catalyst for adaptation potential increase of students during the COVID-19 pandemic

Physical education classes at all Russian universities are mandatory and held during the first, second and third years of studying for a bachelor’s degree. In connection with switching to distance learning during the COVID-19 pandemic, the investigated students of Kazan Federal University were engaged in both online physical education classes and self-study physical education classes with the obligatory keeping of a self-monitoring diary, which allowed tracking the dynamics of changes in psycho-emotional, functional states as well as physical fitness. As part of the educational process, teachers and students contacted through the Microsoft Teams platform, where classes and consultations were held; information and control materials were exchanged. A control group and an experimental group were formed with 90 students in each of the groups totalling 180 students. Each of the groups included 30 students of the main subgroup (healthy), 30 students of the preparatory subgroup (with minor deviations in health), and 30 students of the special medical subgroup with confirmed diseases of various nosology. In the control group, the students were engaged in physical education classes, fulfilling the general requirements: they filled out a self-monitoring diary, carried out the recommended tests to assess functional and physical fitness. Calculation of “working pulse rate” according to Karvonen’s formula gave students the opportunity to determine and select the amount and intensity of physical activity in the process of self-study. According to the self-monitoring diaries, the students showed positive dynamics in the psycho-emotional state. Students also noted the interdependence of their mood, well-being, desire to learn and be active on the quantity and quality of physical education classes. Exercises of sufficient intensity improved mood, relieved feelings of anxiety, and increased the positivity of perception of the surrounding environment. For ten weeks of distance learning, the students of the experimental group, whose physical activity was regulated individually, and the intensity of the load was selected with account of peculiarities of the work of their functional systems, showed a value of adaptation potential higher than that of students of the control group