41 research outputs found

    Nanofibrous carbon with herringbone structure as an effective catalyst of the H2S selective oxidation

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    Granular nanofibrous carbons (NFCs) with herringbone structure were synthesised by the decomposition of natural gas over Ni/Al2O3 catalysts, and their performance in the selective oxidation of hydrogen sulphide was studied. Samples obtained over pure Ni catalysts are the strongest mechanically and easiest to produce. However, they show low selectivity for sulphur and are unstable during operation. Boiling in nitric acid followed by annealing led to improvements in catalytic stability and a significant increase in the selectivity for sulphur in the direct oxidation of hydrogen sulphide. The addition of large amounts of water vapour to the reaction mixture dramatically improved the selectivity and stability of the NFCs. © 2010 Elsevier Ltd. All rights reserved

    ТЕОРЕТИЧЕСКОЕ И ЭКСПЕРИМЕНТАЛЬНОЕ ОБОСНОВАНИЕ ОБРАБОТКИ РАСПЛАВОВ НА ОСНОВЕ АЛЮМИНИЯ ИМПУЛЬСНЫМИ МАГНИТНЫМИ ПОЛЯМИ

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    Factors causing the solid-phase dispersion of the particles of alloying elements in the aluminum melt depending on their nature are considered. It is shown that the particles can be fragmented under the effect of uniform tensile stresses appearing due to heating the particles. The reasonability of using additional external effects (for example, magnetic-pulsed treatment of the foundry-alloy melt) in order to intensify the assimilation of silicon in liquid aluminum and provision of microcrystalline structure of the foundry alloy is substantiated theoretically and confirmed experimentally by the example of the Al–20wt%Si foundry alloy.Рассмотрены факторы, обуславливающие твердофазное диспергирование частиц легирующих элементов, в зависимости от их природы, в алюминиевом расплаве. Показано, что дробление частиц может происходить под воздействием всесторонних растягивающих напряжений, возникающих в результате прогрева частиц. Размеры вновь образующихся в результате дробления частиц определяются протяженностью микротрещин в исходных частицах. На примере лигатуры Al–20мас.%Si теоретически обоснована и экспериментально подтверждена целесообразность использования дополнительных внешних воздействий (например, магнитно-импульсной обработки лигатурного расплава) с целью интенсификации процессов усвоения кремния в жидком алюминии и обеспечения микрокристаллического строения лигатуры

    A difference analog of the korn inequality

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    Expanding the Applications of the Ilmenite Mineral to the Preparation of Nanostructures: TiO2 Nanorods and their Photocatalytic Properties in the Degradation of Oxalic Acid

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    The mineral ilmenite is one of the most abundant ores in the Earth's crust and it is the main source for the industrial production of bulk titanium oxide. At the same time, methods to convert ilmenite into nanostructures of TiO2 (which are required for new advanced applications, such as solar cells, batteries, and photocatalysts) have not been explored to any significant extent. Herein, we describe a simple and effective method for the preparation of rutile TiO2 nanorods from ball-milled ilmenite. These nanorods have small dimensions (width: 520 nm, length: 50100 nm, thickness: 25 nm) and possess large specific surface areas (up to 97 m2?g-1). Dissolution/hydrolysis/precipitation is proposed as a growth mechanism. The nanorods were found to have attractive photocatalytic properties in the degradation of oxalic acid. Their photocatalytic activity is close to that of the benchmark Degussa P25 material and better than that of a commercial high-surface-area rutile powder. © 2013, Wiley-Blackwel

    Evaluation of the effects of interval hypoxic-hyperoxic training in patients with metabolic syndrome

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    Abstract Introduction Metabolic syndrome (MS) as a “cluster” of interrelated disorders, including insulin resistance, visceral obesity, dyslipidemia, and hypertension, is an serious clinical problem that is a high risk factor for the development of type 2 diabetes, acceleration of the development and progression of cardiovascular diseases, and such increasingly common liver damage like non-alcoholic fatty liver disease. According to a number of authors, metabolic syndrome is a reversible condition, and with early diagnosis and treatment, a reduction in the severity of manifestations of this syndrome can be achieved. A significant role in the treatment of MS and obesity is played by non-drug methods – dosed physical activity, diet, various physiotherapeutic procedures, as well as interval hypoxic-hyperoxic training (IHHT). Objective Evaluation of the effect of interval hypoxic-hyperoxic training (IHHT) on the components of metabolic syndrome, and the possibility of their reversal recovery. Materials and methods The study included 65 patients (33 men) with metabolic syndrome, aged 29–66 years. The patients were divided into 2 groups: study and control (the groups were matched by sex, age, presence of MS components and number of comorbidities). Initially, anthropometric, laboratory and instrumental studies were carried out. The patients of the main group underwent a course of IHHT for 3 weeks, 5 days a week (15 workouts). Patients in the control group underwent a course of training simulating IHHT (placebo), which also consisted of 15 trainings. The duration of one procedure was 40 minutes. Next day after the end of the training course, the changes in all initial parameters were assessed. Results The statistical significance of changes after the IGGT course was assessed using the Wilcoxon test as p&amp;lt;0.05 and was detected in the main group according to the following parameters: reduction in arterial stiffness, measured using CAVI (Cardio-Ankle Vascular Index, on the Fukuda Denshi ap.), a decrease in the stage of liver fibrosis and stiffness of liver tissue (was realized by a non-invasive method, a liver elastometry, on the FibroScan ap. Echosense), a decrease in high-sensitivity C-reactive protein, heat shot protein-70, a decrease in total cholesterol, low density lipoproteins, triglycerides levels. According to nitric oxide, transforming growth factor beta-1, heart-type fatty acid binding protein, there was no significant dynamics after the IHHT course in both groups. There was also a tendency towards a decrease in the indices of the abdominal/hip circumference, weight, and in blood pressure, but this results was not statistically significant, due to the insufficient power of the study (a small number of patients). Conclusions IHHT is a safe, well-tolerated procedure and is recommended in the therapeutic and prophylactic plan for patients with metabolic syndrome, and is effective in correcting and minimizing the components of this syndrome. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): This work was financed by the Ministry of Science and Higher Education of the Russian Federation within the framework of state support for the creation and development of World-Class Research Centers “Digital biodesign and personalized healthcare” </jats:sec
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