Electrodialysis Concentration of Sulfuric Acid

Received: 31.12.2020. Revised: 30.03.2021. Accepted: 30.03.2021. Available online: 31.03.2021.This article belongs to the PCEE-2020 Special Issue.An urgent task is the development of new resource-saving technologies for deep processing of wastes from the hydrometallurgical industry for the purpose of their reuse. Membrane technologies make it possible to create closed technological cycles with the reuse of recovered components in production, which allows solving many environmental problems. At the Abinsk Electric Steel Works Ltd. (Russia), during the production of copper-coated steel wire, a large amount of waste containing sulfuric acid and heavy metal salts is generated. The chemical treatment of such effluents with slaked lime and alkali produces a large amount of sludge, which causes environmental problems and leads to the irreversible loss of sulfuric acid. The problem of separating acids and salts can be solved using diffusion dialysis through anion-exchange membranes, however, to return the acid to the production cycle, the purified acid must be additionally concentrated. In this work, we studied the process of electrodialysis concentration of sulfuric acid using heterogeneous ion-exchange membranes Ralex® CMHPP and Ralex® AMHPP (manufactured by MEGA a.s., Czech Republic) which have a polypropylene reinforcing mesh resistant to acids. The main parameters of the electrodialysis concentration process have been determined – the dependence of the concentration of the regenerated sulfuric acid on the concentration at the inlet to the electrodialysis cell and on the current density, as well as the energy consumption for the process. It is shown that with the help of electrodialysis concentration it is possible to obtain sulfuric acid with a concentration of up to 180 g/L, which makes it possible to return it to the production cycle.This study was funded by the Ministry of Education and Science of the Russian Federation (project No. FZEN-2020-0022)

Possible detection of a magnetic field in T Tauri

Medium-resolution $(R\simeq 15000)$ circular spectropolarimetry of T Tauri is presented. The star was observed twice: on November 11, 1996 and January 22, 2002. Weak circular polarization has been found in photospheric absorption lines, indicating a mean surface longitudinal magnetic field $B_{\|}$ of $160\pm 40$ G and $140\pm 50$ G at the epoch of the first and second observations respectively. While these values are near the detection limit of our apparatus, we belive that they are real. In any case one can conclude from our data that $B_{\|}$ of T Tau does not significantly exceed 200 G, which is much less than surface magnetic field strength of the star ($>2.3$ kG) found by Guenther et al. (1999) and Johns-Krull et al. (2000). We discuss possible reasons of this difference.Comment: 5 pages, 3 figure

Особливості архітектурної побудови систем формування тривимірних зображень

У сучасних умовах комп’ютерна графіка стрімко розвивається, оскільки забезпечує високий рівень інформативності, відтворює найвагоміші аспекти процесу або явища. Найбільшу реалістичність забезпечує тривимірна графіка, основана на роботі з просторовими моделями об’єктів, що обумовлює її широке використання в багатьох галузях, пов’язаних з комп’ютерним моделюванням та проектуванням

ОЦІНКА СТАНУ ЗДОРОВ’Я ТА РІВНЯ ФІЗИЧНОГО РОЗВИТКУ СТУДЕНТІВ ЛУЦЬКОГО БАЗОВОГО МЕДИЧНОГО КОЛЕДЖУ

The article  adduces the health condition and level of physical development of students of Lutsk basic medical college in the article based on the evaluation of the Ruffier test and the presence of chronic diseases.У статті наведено дані про стан здоров’я та рівень фізичного розвитку студентів Луцького базового медичного коледжу на основі оцінки проби Руф’є та наявності хронічних захворювань з метою надання ефективних рекомендацій щодо зміцнення здоров’я студентів

The age of Spitsbergen basement consolidation: U–Pb dating of detrital zircons from the Upper Precambrian and Lower Carboniferous clastic rocks of the northwestern part of Nordenskiöld Land

© 2017, Pleiades Publishing, Ltd. The age distribution of detrital zircons from Upper Riphean and Early Carboniferous sandstones of the northwest part of Nordenskiöld Land (Spitsbergen Island) was studied. The results obtained supplement the previously known data on the rocks of Precambrian and Paleozoic masses of West Spitsbergen. Integrated consideration of these data showed that the time interval from the Middle Riphean to the Early Carboniferous inclusive might be subdivided into at least five stages characterized by quite different provinces supplying detritus to sedimentary basins. (The relics of these latter are represented in the present structure of western Svalbard.) The most ancient distinguished event of alteration of the sources of sedimentary matter (at the boundary of the Middle and Late Riphean) corresponds to the consolidation time of the ancient basement of Svalbard

Methods for Specular Color Component Accelerate Calculation

The new approaching for Phong shading method speed increasing is presented in given paper. According to the first approach for those parts of image were highlights is presented is used the Blinn lightning model andfor the restpart the simple Lambert model is applied. Using this method the quality of scene stay the same when we use the complicated Blinn model and the scene creation speed is razed significantly. For Phong shading method is proposed the approach accordingly to which the normal for the current pixel in triangle can be calculated using the normals to the two privies pixels. Given approaches can significantly decrease the amount ofcalculation and thus increase the shading speed