138 research outputs found
Evaluation of efficiency of repulsion in speed-and-strength types of athletics
Efficiency of repulsion in speed-and-strength types of athletics is an integral measure of skill, since the performance of repulsive movements involves interaction of almost all organs and body systems. Dynamic repulsion lays the foundation for high sports results and the conditions of effective interaction of internal and external forces. With the special test exercises, one can determine the level of functioning of individual systems, on which the result of an exercise depends, which during training sessions provides focused opportunity to influence the stimulation of individual systems, increasing their level of activity. The article presents an electromyographic evaluation of the effectiveness of repulsion during the high jump at a run. The implementation of this method will make it possible to objectively evaluate the level of technical skills of athletes and purposefully influence the improvement of basic biomechanical characteristics of sports exercises
Experience with ferrosilicoaluminum alloy during deoxidation of steel
The article describes the process of deoxidation quiet and low-alloyed steel alloy ferrosilicoaluminum complex in comparison the existing, and with steel deoxidation technology with conventional alloys - ferrosilicon and secondary aluminum. A comparative analysis of quality steel, non-metallic inclusions metallographic studies and studies of the mechanical properties of the resulting steel was done. On a large array of experimental steel proved cost-effectiveness and feasibility of ferrosilicoaluminum during deoxidation quiet and low-alloyed steel
Management of technical skills of highly qualified female athletes specializing in athletic jumps
Significant improvement of efficiency in managing technical mastery of female athletes-jumpers depend on the operational response to the emerging new technologies, their approbation and implementation in practice. The article introduces new opportunities for the use of simulators in the process of technical training of highly qualified female jumpers. The authors demonstrate the principal possibility of the applied use of the "facilitating-the-leadership" simulator for improvement of motor actions of female athletes. Obtained results show evident prospects of further expanding of the use of technology and simulators in the system of present-day preparation of highly skilled female athletes
Shell-and-tube latent heat thermal energy storage design methodology with material selection, storage performance evaluation, and cost minimization
Shell-and-tube latent heat thermal energy storage units employ phase change materials to store and release heat at a nearly constant temperature, deliver high effectiveness of heat transfer, as well as high charging/discharging power. Even though many studies have investigated the material formulation, heat transfer through simulation, and experimental studies, there is limited research dedicated to the storage unit design methodology. This study proposes a comprehensive methodology that includes the material assessment with multi-attribute decision-making and multi-objective decision-making tools, epsilon-NTU method, and cost minimization using Genetic Algorithm. The methodology is validated by a series of experimental results, and implemented in the optimization of a storage unit for solar absorption chiller application. A unit cost of as low as USD 8396 per unit is reported with a power of 1.42 kW. The methodology proves to be an efficient, reliable, and systematic tool to fulfill the preliminary design of shell-and-tube LHTES before the computational fluid dynamics or detailed experimental studies are engaged.This research was funded by SJ-NTU Corporate Lab. This research was partially funded by the Ministerio de Ciencia Innovación y Universidades de España (RTI2018-093849-B-C31—MCIU/AEI/FEDER, UE), and the Ministerio de Ciencia, Innovación y Universidades—Agencia Estatal de Investigación (AEI) (RED2018- 102431-T). This work is partially supported by ICREA under the ICREA Academia programme
Frontiers, challenges, and solutions in modeling of swift heavy ion effects in materials
Since a few breakthroughs in the fundamental understanding of the effects of
swift heavy ions (SHI) decelerating in the electronic stopping regime in the
matter have been achieved in the last decade, it motivated us to review the
state-of-the-art approaches in the modeling of SHI effects. The SHI track
kinetics occurs via several well-separated stages: from attoseconds in
ion-impact ionization depositing energy in a target, to femtoseconds of
electron transport and hole cascades, to picoseconds of lattice excitation and
response, to nanoseconds of atomic relaxation, and even longer macroscopic
reaction. Each stage requires its own approaches for quantitative description.
We discuss that understanding the links between the stages makes it possible to
describe the entire track kinetics within a multiscale model without fitting
procedures. The review focuses on the underlying physical mechanisms of each
process, the dominant effects they produce, and the limitations of the existing
approaches as well as various numerical techniques implementing these models.
It provides an overview of ab-initio-based modeling of the evolution of the
electronic properties; Monte Carlo simulations of nonequilibrium electronic
transport; molecular dynamics modeling of atomic reaction on the surface and in
the bulk; kinetic Mote Carlo of atomic defect kinetics; finite-difference
methods of tracks interaction with chemical solvents describing etching
kinetics. We outline the modern methods that couple these approaches into
multiscale multidisciplinary models and point to their bottlenecks, strengths,
and weaknesses. The analysis is accompanied by examples of important results
improving the understanding of track formation in various materials.
Summarizing the most recent advances in the field of the track formation
process, the review delivers a comprehensive picture and detailed understanding
of the phenomena.Comment: to be submitte
Acenaphthenoannulation Induced by the Dual Lewis Acidity of Alumina
We have discovered a dual (i. e., soft and hard) Lewis acidity of alumina that enables rapid one-pot π-extension through the activation of terminal alkynes followed by C−F activation. The tandem reaction introduces an acenaphthene fragment – an essential moiety of geodesic polyarenes. This reaction provides quick access to elusive non-alternant polyarenes such as π-extended buckybowls and helicenes through three-point annulation of the 1-(2-ethynyl-6-fluorophenyl)naphthalene moiety. The versatility of the developed method was demonstrated by the synthesis of unprecedented structural fragments of elusive geodesic graphene nanoribbons
Engineering Education in the Context of Digitalization and Transition to a Green Economy (SYNERGY 2022 Conference Results Review)
The article summarizes the results of the plenary session of the international network conference “Engineering education in the context of digitalization and transition to a green economy – SYNERGY-2022” held at the Nizhnekamsk Chemical Technology Institute of Kazan National Research Technological University from October 13 to 14, 2022. The forum was devoted to the training of engineers in the conditions of digitalization and the transition to a green economy. It brought together representatives of universities and industrial enterprises of Russia and abroad. Among the participants were representatives of national research universities and supporting universities of PJSC Gazprom, state authorities and industrial enterprises of Tatarstan. It was possible to observe the work of the plenary session in real time via the Internet in all the main universities of Gazprom. The organizers of the event were the Ministry of Science and Higher Education of the Russian Federation, the International Society for Engineering Pedagogy (IGIP), the Association of Engineering Education of Russia (AEER), as well as the Ministry of Industry and Trade of the Republic of Tatarstan and the Kazan National Research Technological University. Gazprom PJSC was the general sponsor. In total, the conference gathered more than 200 participants (120 online and 80 in person) from 15 universities in Russia, Germany and Kazakhstan. Representatives of 12 industrial enterprises spoke, 42 reports were made
TA INSTRUMENTS EQUIPMENT FOR FATIGUE TESTING OF STENTS AND IMPLANTS FOR CARDIOVASCULAR SYSTEM
В данной статье рассмотрены устройство и применение испытательных машин ElectroForce компании TA Instruments (США), для проведения широкого диапазона статических и многоцикловых испытаний и изучения физико-механических свойств материалов и готовых изделий. Особое внимание уделено применению систем ElectroForce для усталостных испытаний трансплантатов органов сердечно-сосудистой системы.Construction and application of ElectroForce test systems (TA Instruments, USA) for wide range of static and cycling tests and physical mechanical properties study of materials and complete products are described in this review. The focus attention is given to application of ElectroForce systems for long cycling testing of cardiovascular implants
TECHNOLOGICAL PROPERTIES OF MILK OF COWS WITH DIFFERENT GENOTYPES OF KAPPA-CASEIN AND BETA-LACTOGLOBULIN
The presence of the desirable alleles and genotypes of casein and whey protein genes in the genome of cows affects the milk protein content, quality and technological properties of their milk. Two important properties of milk its producibility is judged on are cheeseability and heat resistance. The present studies aimed at estimating the technological properties of milk of black-motley × Holstein and Kholmogorskaya breeds cows of the Tatarstan type with different kappa-casein (CSN3) and beta-lactoglobulin (BLG) genotypes. The study was carried out using a sampling of the first-calf cows of 5 cattle-breeding farms of the Republic of Tatarstan. In animals, the CSN3 and BLG genotypes have been determined by a PCR-RFLP analysis. The cheeseability, heat resistance and thermostability of milk have been estimated using standard methods. The studies have established that the CSN3 and BLG genotypes of cows affected the condition of a casein clot and duration of milk clotting time. The best cheese-making properties of milk were inherent in the animals with the BB and AB genotypes of the CSN3 and BLG genes. They were superior to the coevals with the AA genotype in terms of the highest yield of the desired dense casein clot and the shortest duration of milk clotting time. The first-calf cows, which are the carriers of an A allele of the CSN3 gene, were superior to the animals with the BB genotype of the CSN3 gene on the thermostability of milk including that on the proportion of animals with this milk characteristic. The BLG genotype of the studied animals did not significantly affect the thermostability of milk. Moreover, the highest thermostability of milk was characteristic of black-motley × Holstein cows with the AA genotype
A comprehensive review on sub-zero temperature cold thermal energy storage materials, technologies, and applications:state of the art and recent developments
The energy industry needs to take action against climate change by improving efficiency and increasing the share of renewable sources in the energy mix. On top of that, refrigeration, air-conditioning, and heat pump equipment account for 25-30% of the global electricity consumption and will increase dramatically in the next decades. However, some waste cold energy sources have not been fully used. These challenges triggered an interest in developing the concept of cold thermal energy storage, which can be used to recover the waste cold energy, enhance the performance of refrigeration systems, and improve renewable energy integration. This paper comprehensively reviews the research activities about cold thermal energy storage technologies at sub-zero temperatures (from around 270 ◦C to below 0 ◦C). A wide range of existing and potential storage materials are tabulated with their properties. Numerical and experimental work conducted for different storage types is systematically summarized. Current and potential applications of cold thermal energy storage are analyzed with their suitable materials and compatible storage types. Selection criteria of materials and storage types are also presented. This review aims to provide a quick reference for researchers and industry experts in designing cold thermal energy systems. Moreover, by identifying the research gaps where further efforts are needed, the review also outlines the progress and potential development directions of cold thermal energy storage technologies.The authors would like to acknowledge the funding support from SJ-NTU Corporate Lab.
This work was partically funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018-093849-B-C31 - MCIU/AEI/FEDER, UE), and the Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) (RED2018-102431-T). The authors at the University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2017 SGR 1537). GREiA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. This work is partially supported by ICREA under the ICREA Academia program
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