Electrodeposition of Silicon from Molten KCl-K2SiF6for Lithium-Ion Batteries

In this paper we report characteristics and electrochemical properties of silicon fibers used as lithium-ion battery anode. All samples were synthesized by potentiostatic electrodeposition from molten KCl K2SiF6. From molten KCl CsCl K2SiF6 deposition was carried out in galvanostatic mode. Despite the synthesis in inert atmosphere and absence of oxygen containing compounds in the melt resulting silicon after washing contains at least 15 at% oxygen. Silicon fibers synthesized at ?250 mV (vs Si) were the thinnest with diameter as small as 100 nm; average fiber length increased with increasing overvoltage. Addition of CsCl to the melt results in decrease of the average fibers diameter. Silicon fibers synthesized at ?250 mV (vs Si) in KCl K2SiF6 melt showed the best cycling performance with capacity of 1030 mAh g?1 at 0.2 A g?1 discharge current and capacity of 715 mAh g?1 after 10 cycles. Lithium diffusion coefficients calculated from galvanostatic intermittent titration technique (GITT) are common for silicon-based anode. The highest initial diffusion coefficient value of 6.68 10?11 cm2 s?1 was achieved for silicon synthesized from melt with addition of CsCl. Low capacity and rapid capacity fading for all samples can be caused by high silicon dioxide content, further treatment of synthesized silicon is necessary to achieve higher performance. © 2022 The Author(s).This work is performed in the frame of the State Assignment number 075-03-2022-011 dated 14.01.2022 (the theme number FEUZ-2020-0037)

Geotechnical properties of gullying in Tomsk Oblast

The article deals with causes, conditions and factors of gullying in Tomsk Oblast, the case of site Grodnenskaya. A nuclear-power station was planned to be constructed in Closed Administrative Territorial Unit Seversk, which led to geotechnical investigation of the area to study the geological processes developing there. The investigation included reconnaissance traverse of the area, geological and geomorphic descriptions, and sampling. The area and percentage of the territory affected by the geological processes were estimated. As a result, it was proved that the geological processes of the area are conditioned by surface water activity leading to gullying and river erosion, and by both ground water and surface water activity resulting in bog formation. It appears that gullying is caused not only by natural factors but also by technogenic ones

Problems of Surgical Treatment of Hammer Toes (Review of Literature)

Introduction. The urgency of the problem of surgical treatment of hammer-like deformity of the toes is due to the incidence of pathology, the presence of unsatisfactory results and postoperative complications.Objective. Analysis of scientific literature devoted to the problems of surgical treatment of hammer deformities of the toes.Materials. Analyzed domestic and foreign scientific publications on the classification and surgical treatment of hammer toes.Results. The article presents an analysis of the classifications of hammer-like deformity of the toes and instability of the metatarsophalangeal joints and an analysis of treatment methods aimed at eliminating various manifestations of deformity, with a description of the complications that have arisen. The systematization of methods for correcting hammer-like deformity of the toes was carried out.Conclusion. Analysis of the literature data allowed us to determine that the problems of treating hammer-like deformity of the toes are associated with the lack of a classification that would reflect the condition of the forefoot of each individual patient and allow choosing the optimal effective methods of treatment, as well as an algorithm for choosing tactics for surgical treatment of hammer-like deformity, which systematizes the methods treatment depending on the manifestations of deformity of the entire forefoot

Orientation, substructure, and optical properties of rutile films

The orientation, optical properties, and substructure of rutile films prepared by thermal and pulsed photon assisted oxidation of single crystal Ti films were investigated by transmission electron micros copy, optical spectroscopy, and high energy electron diffractionyesBelgorod State Universit

New method of surgical correction of lesser toes deformity

Background. Patients’ dissatisfaction with the results of surgical correction of lesser toes deformities, the shortcomings of methods aimed at eliminating the lateral deviation of the toe in the metatarsophalangeal joint necessitated the development of a new surgical method.The aim. To evaluate short-term results of the new surgical method for the treatment of patients with lesser toes deformity, accompanied with deviation of the toe.Materials and methods. A method of surgical treatment of deviated deformity of the small toes is proposed. The method includes precise marking of the metatarsal osteotomy line according to the previously calculated parameters of optimal shortening and displacement of the metatarsal bone, performing oblique diaphyseal osteotomy of the metatarsal bone, displacing its distal part along the osteotomy plane. According to the proposed method, nine patients were operated on who had a syndrome of nonrigid hammer-like deformity of the second toe with lateral deviation of the toe in the metatarsophalangeal joint. In all patients, the deformity of the second toe was associated with hallux valgus.Results. As a result of the application of the proposed method, it was possible to achieve deformity correction, eliminate the lateral deviation of the second toe in the metatarsophalangeal joint, restore congruence in the joint, achieve consolidation of bone fragments without loss of correction, and improve the appearance and function of the foot. Three months after the operation, a statistically significant improvement was determined, according to the AOFAS LMIS scale, having reached 94.5 ± 4.64 points, which made it possible to speak about the achievement of a good functional result of treatment. Patients noted the opportunity to wear standard footwear, to carry out their labor activity, to engage in physical culture, were satisfied with the result.Conclusion. The use of the proposed new surgical method for deflected deformity of the lesser toes makes it possible to correct the deformity, eliminate lateral deviation of the toe, relieve pain syndrome, achieve a good cosmetic and functional result, restoring the patients’ ability to wear standard shoes

Photovoltaic Response of Silicon Wafers Treated in the K2WO4-Na2WO4-WO3Melt

Texturing silicon wafers is one way to increase the performance of solar cells. This work is the first to report on the surface modification of Si wafers by processing in polytungstate melts. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction analysis (XRD), the Brunauer-Emmett-Teller (BET) method, and photoelectrochemical measurements were used to elucidate the effect of texturing conditions in the Na2WO4 - K2WO4 (1:1) melt containing 35 or 50 mol% WO3 at 973 K in air. As a result of cathodic treatment in the melt containing 50 mol% WO3 at the potential of -0.92 V (vs Pt) for 15 s, upright pyramids were formed on the Si surface. In addition, inverted pyramids appeared at the OTB/Si contact points. The photocurrent density of these samples was several times higher than that for the initial Si wafer or the Si wafer etched in 5 M NaOH solution at 353 K for 20 min. Mechanisms for the formation of upright and inverted pyramids were proposed. Unusual eight-faceted pyramids were formed on the Si surface during cathodic treatment in the melt containing 35 mol% WO3 at -1.19 V for 15 s, but the photocurrent density of such samples was low. © 2021 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.This work is performed in the frame of the State Assignment number 075-03-2020-582/1 dated 18.02.2020 (the theme number 0836-2020-0037). This work has been (partly) done using facilities of the Shared Access Center "Composition of Compounds" (IHTE, UB RAS)

Method for Surgical Treatment of Hammer Deformity of the Second Toe

The article presents a case of successful surgical treatment of a patient with hammer-like deformity of the second toe associated with deformity of the first toe. During the preoperative examination of the patient, the length of the required shortening of the second metatarsal bone relative to the length of the third metatarsal bone was calculated on the X-ray in frontal projection and the length of the required shortening of the first metatarsal bone was calculated using a known method. To eliminate the deformity of the first toe, the author’s method of surgical treatment was used. To correct the deformation of the second toe, the proposed method was used, which includes the following steps: marking the lines of osteotomies during the operation; performing osteotomies along the outlined lines; removal of a free bone fragment; precise implementation of  the required shortening of the second metatarsal bone; fixation of the osteotomized fragments of the second metatarsal bone with a cannulated screw. As a result of the performed surgical treatment, correction of the hallux valgus and hammer-like deformity of the second toe was achieved.The presented clinical case shows that in the surgical treatment of hammer deformity of the second toe, it is important to take into account the individual characteristics of the patient’s foot condition, namely, the ratio of the length of the second and adjacent third metatarsal bones. Preliminary calculation of the length of the required shortening of the second and first metatarsal bones on the roentgenogram, precise markings of the  osteotomy lines and the implementation of the necessary shortening contribute to achieving a balance in the ratio of the lengths of the metatarsal bones, restoring the optimal load distribution on the heads of the metatarsal bones, more accurate correction of the deformity of the second and first toes, and improving statodynamic function of the foot and reducing the risk of postoperative failures