Электрохимическое обезмеживание медно-сульфатного электролита

Copper and nickel ions are accumulated in the solution during electrolytic refining of copper. These ions need to be extracted from the solution from time to time. In industry copper extraction is carried out in two stages. It results in copper ions concentration reducing to 1 g/l. Numerical simulation was used to define dependence of the process of copper extraction from particular parameters: mixing of electrolyte, volume of electrolyte, area of cathodic surface. The process of copper extraction was investigated in still electrolyte and during mixing of the solution. Smooth and compact precipitate crystallized on the cathode in all experiments. Rate of copper extraction during mixing of electrolyte is higher than in still electrolyte. The industrial method of abuseive sulphate electrolyte results in the formation on the cathode dendritic sediment copper ions which are restored in extreme conditions. The decrease in the concentration of copper at I = const causes the formation of dendritic sludge that is easily crumbles to the bottom of the cell, enriching copper sludge. Guarantee smooth sediment when basmajian with obtaining compact copper, excluding besides the recovery of arsenic emitting poisonous arsina cars is the organization of intensive mixing or electrolyte circulation, ensuring the recovery of copper ions in limitless conditions smooth and sediment.При электролитическом рафинировании меди в растворе электролита накапливаются ионы никеля и меди, которые необходимо периодически извлекать. В промышленности извлечение меди проводят в две стадии, снижая концентрацию меди до 1 г/л. Численным моделированием установлена зависимость скорости обезмеживания от отдельных параметров: перемешивания электролита, его объема, площади катодной поверхности,. Экспериментально исследован процесс обезмеживания в спокойном электролите и при перемешивании раствора. Во всех опытах на катоде кристаллизовался гладкий, компактный осадок меди. Скорость обезмеживания при организации принудительного перемешивания выше, чем в спокойном электролите

Point vortices and classical orthogonal polynomials

Stationary equilibria of point vortices with arbitrary choice of circulations in a background flow are studied. Differential equations satisfied by generating polynomials of vortex configurations are derived. It is shown that these equations can be reduced to a single one. It is found that polynomials that are Wronskians of classical orthogonal polynomials solve the latter equation. As a consequence vortex equilibria at a certain choice of background flows can be described with the help of Wronskians of classical orthogonal polynomials.Comment: 20 pages, 12 figure

Combination of active stage of diabetic Charcot neuroosteoarthropathy and diabetic lower limb macroangiopathy

Combination of active stage of diabetic Charcot neuroosteoarthropathy and diabetic lower limb macroangiopathy is the rare condition. In the present paper we describe two cases of development of acute Charcot foot in the non-critically ischemic foot. The first case is the patient with previously diagnosed intermitted claudication and the second case is patient who developed the Charcot foot 5 months later after successful endovascular treatment of arterial occlusions of his left lower limb. In both cases the absence of redness in the early stage, the mild-to-moderate pain and mild temperature gradient between affected and non-affected feet were noticed. The clinical course of the Charcot disease in the first patient was favourable. He used walker for 9 months and his foot shape was preserved and deformity was considered as mild. The second patient had more active and profound destructions due to delay of the treatment. He was casted, however his deformity progressed and the treatment continues up to date. In both patients the MRI revealed more affected bones compared with X-ray. These cases emphasize the importance of keeping in mind the Charcot disease even in patients with diabetic peripheral vascular disease

HLA-B27-associated uveitis: From pathogenesis to therapy

Uveitis is the inflammation of the uvea, which generally occurs in young people and may be accompanied by serious complications leading to disability. The review analyzes the data of Russian and foreign investigations on the pathogenesis of HLA-B27-associated uveitis occurring in different diseases from a group of seronegative spondyloarthritides (SpA) and also discusses current therapeutic approaches in this disease.Since the late 20th century, there has been rapid progress in studying the pathogenesis of HLA-B27-associated uveitis and in identifying the genetic factors predisposing to this pathology. Investigations of HLA-B27 antigen and its alleles are being continued. Tumor necrosis factor-α (TNF-α), the higher levels of which in blood, synovial fluid, and ocular fluid in rheumatic diseases has been proven in many works of both foreign and Russian scientists, is most studied among the inflammatory mediators. Due to the key role of this cytokine in the development of inflammation, drugs inhibiting TNF-α activity have been designed and successfully used in the past decade, which results in partial and occasionally stable remission

Short-term outcomes of treatment of active stage of Charcot foot in outpatient setting

Background: Treatment options in patients with an acute Charcot foot is not well standardized and still challenging.Aims: To evaluate the results of the non-operative treatment of patients with active stage of diabetic charcot arthropathy in outpatient foot clinic and to identify factors influenced on treatment results.Materials and methods: Medical files of 141 patients with unilateral ulcer-free active charcot arthropathy were reviewed. 78 patients agreed for treatment (total contact cast or walker), 63 patients refused of treatment (follow-up only). The time of resolution of the acute stage, severity of final deformities and foot-related complications were evaluated. Refusers were asked about the cause of their decision.Results: Mean delay of the diagnosis was 3,2±2,8 months. Main causes of the refuse were: mistrust to doctor - 38%, problems with employment - 33%, home/family problems - 18%, medical reasons - 11%. Median healing times (months) in the treatment group vs controls: 9 (6 - 19) 15 (13 - 25) (p=0,001) and progression of the initial deformity: 14% and 35%, respectively (p=0,01). Foot-related complications: 17,5% in the treatment group and in 55,6% of controls (including 6 amputations) (p=0,001). Frequency of breaking the cast/walker - 32%/16,6%. Foot lesions due to cast/walker: 13,6%/41,7% (p<0,01). Median healing times (months) with walkers - 13 (11 - 19), with casts - 9 (6 - 15) months (р=0,02). The use of crutches shortened healing time.Conclusions: The significant delay of diagnosis was revealed. The refuse rate in our cohort was high and main causes of the refuse were social and psychological. Neglect of treatment leads to high frequency and severity of foot-related complications. We noticed high rate of breaking of walkers and casts and device-related foot lesions. Total contact casts were more effective and safe compared with walkers

HLA-B27-ASSOCIATED UVEITIS: EPIDEMIOLOGY, CLINICAL PICTURE, AND COMPLICATIONS

Anterior uveitis is the most common form of intraocular inflammation. Among them, HLA-B27-associated uveitis occupies one of the leading places, which may be an independent disease or one of the manifestations of spondy- loarthritis (SA). The paper considers the general issues of the nomenclature and classification of uveitis, by using the classification criteria of the International Uveitis Study Group and the Standardization of Uveitis Nomenclature Workshop. The epidemiological aspects of uveitis are described. Emphasis is laid on a difference in the detection rate of uveitis in different countries, in men and women, as well as in different forms of SA. The clinical features of SA- associated uveitis and its complications are discussed

On elliptic solutions of the quintic complex one-dimensional Ginzburg-Landau equation

The Conte-Musette method has been modified for the search of only elliptic solutions to systems of differential equations. A key idea of this a priory restriction is to simplify calculations by means of the use of a few Laurent series solutions instead of one and the use of the residue theorem. The application of our approach to the quintic complex one-dimensional Ginzburg-Landau equation (CGLE5) allows to find elliptic solutions in the wave form. We also find restrictions on coefficients, which are necessary conditions for the existence of elliptic solutions for the CGLE5. Using the investigation of the CGLE5 as an example, we demonstrate that to find elliptic solutions the analysis of a system of differential equations is more preferable than the analysis of the equivalent single differential equation.Comment: LaTeX, 21 page

Vortices ans Polynomials: Nonuniqueness of the Adler-Moser polynomials for the Tkachenko equation

Stationary and translating relative equilibria of point vortices in the plane are studied. It is shown that stationary equilibria of a system containing point vortices with arbitrary choice of circulations can be described with the help of the Tkachenko equation. It is obtained that the Adler - Moser polynomial are not unique polynomial solutions of the Tkachenko equation. A generalization of the Tkachenko equation to the case of translating relative equilibria is derived. It is shown that the generalization of the Tkachenko equation possesses polynomial solutions with degrees that are not triangular numbers.Comment: 15 pages, 2 figure

High-efficiency freezing-induced loading of inorganic nanoparticles and proteins into micron- and submicron-sized porous particles

We demonstrate a novel approach to the controlled loading of inorganic nanoparticles and proteins into submicron- and micron-sized porous particles. The approach is based on freezing/thawing cycles, which lead to high loading densities. The process was tested for the inclusion of Au, magnetite nanoparticles, and bovine serum albumin in biocompatible vaterite carriers of micron and submicron sizes. The amounts of loaded nanoparticles or substances were adjusted by the number of freezing/thawing cycles. Our method afforded at least a three times higher loading of magnetite nanoparticles and a four times higher loading of protein for micron vaterite particles, in comparison with conventional methods such as adsorption and coprecipitation. The capsules loaded with magnetite nanoparticles by the freezing-induced loading method moved faster in a magnetic field gradient than did the capsules loaded by adsorption or coprecipitation. Our approach allows the preparation of multicomponent nanocomposite materials with designed properties such as remote control (e.g. via the application of an electromagnetic or acoustic field) and cargo unloading. Such materials could be used as multimodal contrast agents, drug delivery systems, and sensors