Obtaining of Maghemite Containing Red Mud for Effective As(V) Adsorption

This paper describes the studies of the use of red muds as adsorbents for cleaning solutions from As(V). The red mud is a waste that contains a large amount of iron oxides and hydroxides, which are excellent adsorbents of arsenic, especially those possessing magnetic properties and large specific surface area. The purpose of the experiment was to study the possibility of obtaining an effective adsorbent by direct extraction of alumina from bauxite using the caustic alkali fusion method and optimization of the process. The main iron-containing phase of the red muds obtained by fusing bauxite with caustic alkali was maghemite, which has a large specific surface area. Arsenic adsorption experiments were carried out using red muds obtained through bauxite alkali fusing at different temperatures and time of fusion, as well as the mass ratio of caustic alkali to bauxite. The red muds obtained by fusing bauxite with caustic alkali at 400∘ C and NaOH to bauxite mass ration 1.5 within 70 minutes have the highest effectiveness removing arsenic. Their As(V) uptake capacity was over than 37 mg/g. Keywords: red mud, maghemite, nanoparticles, As(V) adsorption, optimizatio

РАССТРОЙСТВА ТРЕВОЖНО-ДЕПРЕССИВНОГО СПЕКТРА У ПАЦИЕНТОВ С ХРОНИЧЕСКОЙ ТРОМБОЭМБОЛИЧЕСКОЙ ЛЕГОЧНОЙ ГИПЕРТЕНЗИЕЙ В ОТДАЛЕННЫЕ СРОКИ ПОСЛЕ ОПЕРАЦИИ

HighlightsThe article presents the analysis of anxiety and depressive disorders in patients who were followed as outpatients after surgery for chronic thromboembolic pulmonary hypertension in the long term, taking into account the study during the COVID–19 pandemic.The prevalence of clinically pronounced anxiety disorders in the group was 10.9%, depression - 18.6%, a combination of anxiety-depressive disorders was noted in 10.3% of cases.Multifactorial analysis revealed that the development of severe anxiety disorders in patients with chronic thromboembolic pulmonary hypertension in the long term is associated with a complicated postoperative course. Independent risk factors for clinically pronounced depressive disorders in these patients were older age, a history of cerebral circulation disorders, as well as pronounced post-COVID-19 functional disorders. Aim. To study the frequency and severity of anxiety-depressive disorders in patients with chronic thromboembolic pulmonary hypertension (CTEPH) in the long term after pulmonary thromboendarterectomy and to identify factors affecting their development.Methods. 156 patients with CTEPH were examined in the long term after surgery using the generalized anxiety disorder (GAD) questionnaire GAD-7 and the Beck`s Depression Inventory. In patients who suffered COVID-19, a “Post-COVID-19 Functional Status scale” (PCFS) was used to measure functional status over time after COVID-19. Logistic regression analysis was used to identify predictors of clinically pronounced GAD and depression in the long-term period after surgery.Results. In patients with CTEPH, clinically significant GAD and depression in the long term after surgery were observed in 10.9 and 18.6% of cases, respectively. A combination of anxiety and depressive disorders was noted in 10.3% of patients. The development of GAD was associated with cardiopulmonary insufficiency in the early postoperative period (ОR 3,1; CI 1,2–13,8; p = 0,009). Clinically pronounced depression was associated with older age (ОR 1,3; CI 1,04–2,0; p = 0,02), chronic cerebral circulatory insufficiency (ОR 7,6; CI 1,8–17,5; p = 0,02) and pronounced post-COVID-19 functional neurological disorders according to the PCFS scale (ОR 6,7; CI 1,9–14,5; p = 0,007). The combination of clinically expressed anxiety and depression was correlated with older age (ОR 1,1; CI 1,02–1,3; p = 0,04).Conclusion. The prevalence of clinically pronounced GAD in the group was 10.9%, depression was 18.6%, and a combination of anxiety and depressive disorders was noted in 10.3% of patients. The development of clinically significant GAD is associated with a complicated course of cardiac surgery. Independent risk factors for clinically significant depression were older age, a history of cerebral circulatory disorders and pronounced post-COVID-19 functional neurological disorders.Основные положенияСтатья посвящена изучению тревожных и депрессивных расстройств у пациентов диспансерной группы наблюдения с хронической тромбоэмболической легочной гипертензией в отдаленные сроки после хирургического вмешательства с учетом проведения исследования в период пандемии COVID-19.Распространенность клинически выраженных тревожных расстройств в изучаемой группе составила 10,9%, депрессии – 18,6%, сочетание тревожно-депрессивных расстройств зарегистрировано в 10,3% случаев.Многофакторный анализ показал, что развитие выраженных тревожных расстройств у пациентов с хронической тромбоэмболической легочной гипертензией в отдаленные сроки после хирургического вмешательства ассоциировано с осложненным течением операции. Независимыми факторами риска клинически выраженных депрессивных расстройств у данных пациентов явились старший возраст, нарушения мозгового кровообращения в анамнезе, а также выраженные постковидные функциональные нарушения. Цель. Изучить частоту и тяжесть тревожно-депрессивных расстройств у пациентов с хронической тромбоэмболической легочной гипертензией (ХТЛГ) в отдаленные сроки после тромбэндартерэктомии из легочной артерии и выявить факторы, влияющие на их развитие.Материалы и методы. Обследовано 156 пациентов с ХТЛГ в отдаленные сроки после операции с помощью опросника генерализованного тревожного расстройства (ГТР) GAD-7 и шкалы депрессии Бека. У больных, перенесших COVID-19, проведена оценка по шкале постковидного функционального статуса (PCFS). С помощью логистического регрессионного анализа выявлены предикторы клинически выраженных ГТР и депрессии в отдаленный период после операции.Результаты. У больных ХТЛГ клинически значимые ГТР и депрессия в отдаленный период после операции наблюдались в 10,9 и 18,6% случаев соответственно. Сочетание тревожно-депрессивных расстройств отмечено у 10,3% пациентов. Развитие клиники ГТР ассоциировано с сердечно-легочной недостаточностью в раннем послеоперационном периоде (ОШ 3,1; ДИ 1,2–13,8; p = 0,009). Клинически выраженная депрессия ассоциирована с более старшим возрастом (ОШ 1,3; ДИ 1,04–2,0; p = 0,02), хронической недостаточностью мозгового кровообращения (ОШ 7,6; ДИ 1,8–17,5; p = 0,02) и выраженными постковидными нарушениями функционального статуса по шкале PCFS (ОШ 6,7; ДИ 1,9–14,5; p = 0,007). Сочетание клинически выраженной тревоги и депрессии взаимосвязано с более старшим возрастом (ОШ 1,1; ДИ 1,02–1,3; p = 0,04).Заключение. Распространенность клинически выраженных ГТР в изучаемой группе составила 10,9%, депрессии – 18,6%, сочетание тревожно-депрессивных расстройств зарегистрировано у 10,3% пациентов. Развитие клинически значимых ГТР ассоциировано с осложненным течением кардиохирургического вмешательства. Независимыми факторами риска клинически значимой депрессии явились старший возраст, нарушения мозгового кровообращения в анамнезе и выраженные постковидные функциональные нарушения

Cluster strategies in the regional economy development: legal aspects

Objective to study the state of legal support of the cluster strategies implementation to identify the problems and possible directions for improving the legal support of cluster development in the regions. Methods systemic structuralfunctional induction and deduction analysis and synthesis formal legal. Results the paper formulates the definition of cluster as a form of cooperative interaction of organizations interacting in some economic sphere due to functional dependence complementing each other and reinforcing the competitive advantages of individual companies. The hypothesis is proposed that the organizational and management structure of clusters should be unified and obtain normative fixation so that the same type of bodies including executive bodies and the structure of the different clusters deliberative specialized organizations organizationcoordinator etc. had similar competence and position in the management hierarchy. Scientific novelty following the most general conception of a cluster as interacting institutions in a specific area one can see that the lack of clarity in the legal support of the clusters functioning does not allow to determine the status of authoritative and nonauthoritative subjects of economic activities their organizationallegal forms and the procedure of their interaction. Practical significance the identified problems of legal support of the cluster strategies implementation can help in the improvement of state regulation of cluster relations in the regions and their implementation

The Role of the Peoples of the Uralic Language Family in the Formation and Development of the Russian Civilization

The study examines the territorial organization of the Ural peoples and languages, reveals the features of the regional interaction and population dynamics, addresses the problems of the ancestral homeland and ethno genesis, the role of Finno-Ugrians in the history of Russia, highlights the acute issues of preserving languages and culture. The research focuses on some features in the development of the Uralic ethnic groups within the framework of the Russian civilization. It is alleged that the ethnic and political consolidation of most Finno-Ugric tribes was born in the bowels of the ancient Russian state and the first sprouts of the future unity of peoples were born, and their role in the powerful national-state construction that unfolded on the huge Eurasian territory of Russia in the period between 16th and 20th century is analyzed. The outcomes confirm that the Finno-Ugric peoples have always been an organic part of the Russian ethno-cultural mosaic. They actively participated in the strengthening of the state, mastered its vast natural wealth, and created the economic power of the country. Due to the fact that in Finno-Ugric, significant attention is paid to the problems of preserving languages and culture among Samoyed peoples, which cannot be called Finno-Ugric, we propose to use the term "Uralistics" more widely. This is a more accurate concept and can be used in the study of cultural processes among the peoples united in the Uralic language family

Increased As Adsorption on Maghemite-Containing Red Mud Prepared by the Alkali Fusion-Leaching Method

This study investigates the use of red muds as adsorbents for As (V) removal. Red mud is a waste that contains a large amount of iron oxides and hydroxides, which are excellent adsorbents of arsenic, especially those possessing magnetic properties and a large specific surface area. The purpose of the experiments was to study the possibility of obtaining an effective adsorbent by the direct extraction of alumina from bauxite using the caustic alkali fusion method and to compare the arsenic removal effectiveness and other properties of these red muds with industrial samples. Red muds were described using methods such as X-ray diffraction spectrometry (XRD), X-ray fluorescence spectrometry (XRF), SEM, vibrating sample magnetometry (VSM), and the Brunauer⁻Emmett⁻Teller (BET) method. The main iron-containing phase of the red muds obtained by fusing bauxite with caustic alkali is maghemite, which has a large specific surface area. The specific surface area of the obtained samples varied in the range of 6.1⁻54.9 m2/g. Arsenic adsorption experiments were carried out using five different types of red muds: industrial Bayer, industrial sintering, and red mud obtained through bauxite alkali fusion at 300, 500, and 700 °C. The red muds obtained by fusing bauxite with caustic alkali at 300 and 500 °C had the highest effectiveness removing arsenic; their As(V) uptake capacity was over 30 mg/g

Evaluation of the Microstructure and Mechanical Properties of a New Modified Cast and Laser-Melted AA7075 Alloy

The mechanical properties and microstructure of as-cast and homogenized AA7075 were investigated. This alloy was modified by adding transition elements 0.3%Sc + 0.5%Zr, 1%Ti + 0.2%B, and 1%Fe + 1%Ni for use in additive manufacturing applications. After adding Ti + B and Sc + Zr, the structure became uniform and finer with the formation of the Al3(Sc, Zr) and TiB2 phases. Coarse structures were obtained with the formation of an extremely unfavorable morphology, close to a needle-like structure when Fe + Ni was added. The mechanical properties of the modified alloys were increased compared to those of the standard alloy, where the best ultimate tensile strength (UTS) and yield strength (YS) were obtained in the AA7075-TiB alloy compared to the standard alloy in as-cast and homogenized conditions, and the highest hardness value was provided by Fe + Ni additives. The effect of the laser melting process on the microstructure and mechanical properties was investigated. Single laser melts were performed on these alloys using 330 V and a scanning speed of 8 mm/s. During the laser melting, the liquation of the alloying elements occurred due to non-equilibrium solidification. A change in the microstructures was observed within the melt zone and heat-affected zone (HAZ). The hardness of the laser-melted zone (LMZ) after adding the modification elements was increased in comparison with that of the standard alloy. Corrosion testing was performed using a solution of 100 mL distilled water, 3.1 g NaCl, and 1 mL HCl over 5, 10, and 30 min and 1 and 2 h. The corrosion resistance of the alloy modified with FeNi was low because of the non-uniform elemental distribution along the LMZ, but in the case of modification with ScZr and TiB, the corrosion resistance was better compared to that of the standard alloy