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One of the urgent tasks in the process of creating biomechanical devices, namely unloading orthoses, is to determine their effectiveness. The paper presents the results of a study of muscle fatigue of the hip synergists during isotonic contractions when performing squats both with and without the use of a knee joint unloading orthosis. In addition to determining indirect indicators that determine peripheral muscle fatigue, namely the number of squats performed and the speed of their implementation, another effective method for studying the progression of muscle fatigue, the method of surface electromyography, was used in the work. The data obtained in field experiments for both indirect indicators and surface electromyography recordings were processed by calculating the root mean square value, which made it possible to evaluate the effectiveness of the knee joint unloading orthosis using a regression statistical model. The coefficient of absolute slope of the linear regression, built on the basis of experimental data, was chosen as the criterion for evaluating the effectiveness. Surface electromyography data were recorded using the iiitech electromyographic reading module and processed using the Spike Recorder software package supplied with the module. Statistical processing of research results and calculations of linear regression coefficients were carried out using the MS Excel package. The analysis of the results obtained indicates the effectiveness of the use of the orthosis involved in the experiments, the use of which makes it possible to delay the decrease in the production strength of active muscle fibers and leads to a slower onset of peripheral muscle fatigue. [ABSTRACT FROM AUTHOR]

The article is devoted to the topical problem of development and creation of environmentally friendly materials and technologies for foundry production. In recent years, priorities have changed in the development of materials and technological processes towards their compatibility with the environment. The environmental aspects of production come to the fore, which are determined by harmful emissions into the atmosphere, which is strictly regulated by the Kyoto Protocol. In the foundry industry to obtain castings in disposable forms, various technologies have been developed and used, which can be separated based on the type of mold used and the method of its manufacture. The main content of the study is the analysis of traditional foundry technologies and the most promising technology of casting in low-temperature forms (NTF). The peculiarity of casting in NTF is a significant increase in the strength of molds, compared with casting in sand-clay molds, as well as the possibility of using water as the main binder. This method of mold making improves the structure, increases the accuracy and geometry of castings, saves molding materials, and, most importantly, improves the environment by eliminating harmful emissions into the atmosphere of foundries. However, the method of casting in NTF has a number of disadvantages associated with the formation on the surface of castings of shells, pores, as well as increased burns. To eliminate these shortcomings, it is proposed to apply non-stick coatings on the surface of NTF and rods. Considerable attention is paid to the development and research of non-stick coatings, which allow the use of environmentally friendly casting technology in NTF for the production of castings from various alloys of high quality. Coating compositions and methods for determining the optimal composition of non-stick coating, which could be recommended for the production of aluminum castings in low-temperature molds, are identified and described. The obtained results indicate a high potential for the use of this technology as a means of improving the environmental safety of foundry production. [ABSTRACT FROM AUTHOR]

The decision of the problem of three-dimensional modeling according to the developed drawings of experimental implants for the reinforcement of femoral bones with the possibility of variation of their parameters according to individual anthropometric features of each patient is proposed. Three-dimensional models of the implant were constructed using a 3D scan of the femur. The calculation of the strength of the implant under the influence of human weight, using the programs Autodesk 3DsMax 2015 and Inventor was carried out. Three-dimensional implant models enable medical professionals to adjust all the required dimensions of the item to the individual anthropometric features of each patient. The construction of the model gives a clear idea of how the implant will look, taking into account those or other parameters. Three-dimensional modeling can provide useful information on the behavior of the implant and the interacting structures of the body in the “unusual” situations caused by the load and deformation leading to a fracture. This information allows us to formulate an additional medical “technical” justification for the correct choice and accurate installation of the implant. [ABSTRACT FROM AUTHOR]

The growing quantity of people with bone pathology causes the urgency of finding the new reconstruction materials. However, their application may experience different side effects that result the rejection reactions. Materials based on hydroxyapatite are the most widely used in osteoplasty as this material is characterized by its non-toxicity, biocompatibility and corrosion resistance. Hydroxyapatite in its chemical composition is analogous to the mineral constituent of bone, contributing to its regeneration. Aim: The aim is to develop a comprehensive methodology to study the behavior of basalt scales and compositional system “hydroxyapatite - basalt scales” in environments that simulate fluids of living body. Materials and Methods: A comprehensive approach that includes specific preparing of samples and biological environments and complex chemical, photoelectric colorimetric and X-ray studies were applied to evaluate the biochemical stability of the studied material. Calibration curves were prepared during photoelectric colorimetry to determine the amount of substance. Two methods of sample preparation were used to determine the amount of total iron in the filtrate during the study of biochemical stability of the composition systems “hydroxyapatite - basalt scales” in physiological environments. Results: Based on the multi-chemical analysis it can be concluded about the physical and chemical stability in interaction of studied basalt scales powders and composite systems “hydroxyapatite - basalt scales” with the blood plasma and Ringer's solution and Ringer-Locke solution that imitate the fluid of a living body. [ABSTRACT FROM AUTHOR]