Environmental Vulnerability: Theoretical Study of SARSCoV-2 Control During Team Water Sports / Vulnerabilidade ambiental: Estudo teórico do controle do SARSCoV-2 durante esportes aquáticos coletivos

This paper analyzes possible chains of transmission of SARS CoV-2 during water sports practice and discuss control measures of COVID-19 adopted through specific national and international health protocols, more specifically related to the insertion of interventions in the city to propitiate the development of aquatic activities. This is explorative research of technical literature review to present the current state of knowledge regarding the occurrence, persistence and possibility of virus transmission during the practice of collective water sports and related activities. National and International health protocols were analyzed in terms of their safety, functionality and premises. The protocols and studies examined emphasize concerns that the airways are the route of transmission with the highest rate of contamination through respiratory droplets and contact with contaminated surfaces. The research confirmed the hypothesis that the current preventive measures established in health protocols to mitigate the spread of COVID-19 in aquatic environments if observed, are sufficient to prevent the transmission of the disease in these locations. More specifically, to control the spread of the new coronavirus, it is necessary to avoid close contact with another individual without facial protection, crowds, and places with poor ventilation.

Features of braking of multi-axle vehicles depending on the layout of their axles

Problem. For an hour, in the scientific-methodical recommendations of the ship-experts, it is installed in the scientific-technical literature of the day-to-day parameters of galvanizing of vantage, bug-capable transport equipment, so that it is inaccurate to introduce autotransport equipment for the eastern part to inaccurate zasob_v unique road transport suit. Goal. The value of the function of galvanizing large transport bridges on the basis of the coordinates of the position to the center of the heavy transport, realizable values, which are realized between the tires and the supporting surface, as well as the support for the rear axle of the transport bridges. Methodology. The approaches adopted in the work to solve this goal are based on the theoretical foundations of braking multi-axle vehicles, the scientific provisions of elastic deformations of pneumatic tires of automobile wheels, geometric and weight parameters of a wheeled vehicle. Results. The equations that allow to calculate the value of the braking coefficient of multi-axle vehicles based on the coordinates of the position of the center of gravity, the realized couplings between the tires and the bearing surface, as well as the load distribution between the respective front and rear axles of the vehicle. Rivnyannya is assigned, which allow the positioning of the coordinates to the center of the car of a multi-axle wheeled transport vehicle for both front and rear axles. The calculation schemes of the position of the coordinates of the center of mass for two-axle, three-axle and four-axle with different axle layout are presented in graphical form, which give a general idea of the mass distribution between the front and rear axles of the vehicle. Originality. Presented in a graphical view of the layout of the positioning of the coordinates to the center of the car for a two-axle, three-axle and one axle with a small layout of the bridges, which give a far-reaching display of the space between the front and rear axles of the transport vehicle. Practical value. The results can be recommended by the experts-auto technicians in the development of technical capabilities for the drivers of vantage transport means, uniqueness of the road-transport usability.

Using of aluminium slags and products of their pro‑cessing in metallurgical production

The work contains the results of the analysis of technical literature and author’s research on the use of aluminium slags and products of their processing in metallurgical production. It has been shown that the bulk of reagents derived from secondary aluminum production wastes (APWs) are used with increased sodium and potassium chloride. This creates some inconvenience for out‑of‑furnace steel treatment due to the increased chloride content in the working area. It is proposed for steel processing to use APWs formed during flux‑free melting or dump aluminium slags. This allows to reduce the content of salt fluxes residues to 1.0–1.5 % and to improve working conditions at ladle furnaces when liquefying refining slags.

Recent Advancements in Metallurgical Processing of Marine Minerals

Polymetallic manganese nodules (PMN), cobalt-rich manganese crusts (CRC) and seafloor massive sulfides (SMS) have been identified as important resources of economically valuable metals and critical raw materials. The currently proposed mineral processing operations are based on metallurgical approaches applied for land resources. Thus far, significant endeavors have been carried out to describe the extraction of metals from PMN; however, to the best of the authors’ knowledge, it lacks a thorough review on recent developments in processing of CRC and SMS. This paper begins with an overview of each marine mineral. It is followed by a systematic review of common methods used for extraction of metals from marine mineral deposits. In this review, we update the information published so far in peer-reviewed and technical literature, and briefly provide the future perspectives for processing of marine mineral deposits.

METHODS OF ENSURING FUNCTIONAL QUALITY IN ARCHITECTURAL OBJECTS THROUGH TRADITIONAL AND INNOVATIVE TECHNOLOGIES

The issues related to the analysis of technological methods for the formation of architectural objects are considered. The purpose of the research is to identify the scale and prospects for the use of traditional and innovative technologies. Solving problems associated with the development of technological methods and processes is accompanied by the development of general theoretical knowledge of architectural science and building materials science as ways to improve the functional quality of architectural systems and their display in the formats of buildings and structures. The real need to develop a systematic approach and the development of a methodology for integrating the technological component (more precisely, non-traditional or innovative methods and techniques) into the algorithm for the formation of architectural objects predetermined and determined the goal and objectives of this study. The theoretical base of research includes both scientifi c and philosophical works devoted to the object and subject of research in a global aspect, and scientifi c and technical literature, in relation to a specifi c area of architectural activity.

Bearing Capacity of Volcanic Pyroclasts Using the Discontinuity Layout Optimization Method

The failure criterion of low-density volcanic rocks differs radically from that of conventional rocks by manifesting collapse under isotropic stress. In this way, the shapes of the failure model do not reveal a continuously increasing growth of deviating stress with the isotropic stress, but they reach a maximum value, after which they decrease until they vanish under the isotropic collapse pressure. As a consequence, engineering applications require the implementation of numerical codes and the resolution of associated numerical difficulties. This article presents the problem of the bearing capacity of a foundation on a low-density volcanic rock using the DLO (discontinuity layout optimization) numerical method. The analysis of results shows the ability of the DLO method to solve the numerical difficulties associated with the complex failure criteria, so that the convergence and stability of the solution can be achieved without generating high computational costs. Additionally, a discussion of the DLO results is also presented, demonstrating forms of failure on the ground following the real collapses in these volcanic materials. In addition, numerical validation was performed with the finite difference method, using FLAC, and with an analytical method using simplified configurations, obtaining good contrast results, with the DLO method performing better. In this way, an adequate and reliable resolution technique is provided to face the problem of bearing capacity in low-density volcanic rocks, overcoming limitations referred to in the technical literature regarding the difficulty of treating highly non-linear and non-monotonic numerical criteria, which allows the introduction of isotropic collapse failure.

Using Inertial Sensors to Determine Head Motion—A Review

Human activity recognition and classification are some of the most interesting research fields, especially due to the rising popularity of wearable devices, such as mobile phones and smartwatches, which are present in our daily lives. Determining head motion and activities through wearable devices has applications in different domains, such as medicine, entertainment, health monitoring, and sports training. In addition, understanding head motion is important for modern-day topics, such as metaverse systems, virtual reality, and touchless systems. The wearability and usability of head motion systems are more technologically advanced than those which use information from a sensor connected to other parts of the human body. The current paper presents an overview of the technical literature from the last decade on state-of-the-art head motion monitoring systems based on inertial sensors. This study provides an overview of the existing solutions used to monitor head motion using inertial sensors. The focus of this study was on determining the acquisition methods, prototype structures, preprocessing steps, computational methods, and techniques used to validate these systems. From a preliminary inspection of the technical literature, we observed that this was the first work which looks specifically at head motion systems based on inertial sensors and their techniques. The research was conducted using four internet databases—IEEE Xplore, Elsevier, MDPI, and Springer. According to this survey, most of the studies focused on analyzing general human activity, and less on a specific activity. In addition, this paper provides a thorough overview of the last decade of approaches and machine learning algorithms used to monitor head motion using inertial sensors. For each method, concept, and final solution, this study provides a comprehensive number of references which help prove the advantages and disadvantages of the inertial sensors used to read head motion. The results of this study help to contextualize emerging inertial sensor technology in relation to broader goals to help people suffering from partial or total paralysis of the body.

On the Outage Capacity of Transdermal Optical Wireless Links with Stochastic Spatial Jitter and Skin-Induced Attenuation

The tremendous development of both optical wireless communications (OWC) and implantable medical devices (IMDs) has recently enabled the establishment of transdermal optical wireless (TOW) links that utilize light waves to transfer information inside the living body to the outside world and conversely. Indeed, numerous emerging medical applications such as cortical recording and telemetry with cochlear implants require extremely high data rates along with low power consumption that only this new technology could accommodate. Thus, in this paper, a typical TOW link is investigated in terms of outage capacity which is a critical performance metric that has so far not been evaluated for such wireless systems in the open technical literature. More precisely, an outage capacity analysis is performed considering both skin-induced attenuation and stochastic spatial jitter, i.e., pointing error effects. Analytical expressions and results for the outage capacity are derived for a variety of skin channel conditions along with varying stochastic pointing errors which demonstrate the feasibility of this cross-field cooperation. Lastly, the corresponding simulation outcomes further validate our suggestions.

Distribution of kinetic energy losses between nozzles and turbine impeller on partial gas supply modes

В статье приведены результаты экспериментальных исследований связанных с распределением потерь кинетической энергии между сопловым аппаратом и рабочим колесом у осевых малорасходных турбинных ступеней. У всех ступеней конструктивные углы выхода сопел были менее 9°, что повлекло за собой необходимость выполнения рабочих колес с относительным шагом установки рабочих лопаток значительно большим, рекомендованного в технической литературе. Исследования проведены для ступеней со средним диаметром 250 мм. Диапазон изменения факторов составил: отношение давлений перед соплами к давлению за ступенью от 2.0 до 5.0; частоты вращения вала с рабочим колесом от 0 до 14000 . Эффективность использования кинетической энергии приведена в виде коэффициентов скорости соплового аппарата и рабочего колеса. Коэффициенты представляют собой отношение реальной скорости потока на выходе из соплового аппарата (рабочего колеса) к теоретически возможной скорости газа в выходном сечении рассматриваемого элемента ступени. Выявлено, что коэффициенты скорости сопловых аппаратов и рабочих колес изменяются не только при смене режимных параметров, таких как частота вращения ротора и отношения давлений на ступень, но и при изменении степени парциальности ступени. The article presents the results of experimental studies related to the distribution of kinetic energy losses between the nozzle apparatus and the impeller at axial low-flow turbine stages. At all stages, the design angles of the nozzle exit were less than 9 °, which entailed the necessity of making impellers with a relative pitch of the rotor blades that was much larger, as recommended in the technical literature. The studies were carried out for steps with an average diameter of 250 mm. The range of variation of the factors was the ratio of the pressures in front of the nozzles to the pressure behind the stage from 2.0 to 5.0; rotation speed of the shaft with the impeller from 0 to 14000 rpm. The efficiency of using the kinetic energy is given in the form of the coefficients of the speed of the nozzle apparatus and the impeller. The coefficients represent the ratio of the actual flow rate at the outlet of the nozzle apparatus (impeller) to the theoretically possible gas velocity in the outlet section of the stage element under consideration. It was found that the speed coefficients of the nozzle apparatus and impellers change not only when changing operating parameters, such as the rotor speed and the pressure ratio per stage, but also when changing the degree of stage partiality.

Semi-empiric noise modeling of a Cargo eVTOL UAV by means of system identification from flight noise measurement data

This publication shows the semi-empiric noise modeling of an electric-powered vertical takeoff and landing (eVTOL) unmanned aerial vehicle (UAV) by means of system identification from flight noise measurement data. This work aims to provide noise models with a compact analytical ansatz for horizontal and vertical flight which are suited for integration into a geographical information system. Therefore, flight noise measurement campaigns were conducted and evaluated. An existing noise model ansatz is adapted to the eVTOL UAV under consideration and noise models are computed from the measurement data using the output error method. The resulting models are checked for plausibility by comparing them to technical literature. The horizontal flight noise model is subjected to a correlation analysis and the influence of meteorological effects are examined. To achieve a higher level of accuracy in future noise modelings, an optimization of the microphone positions as well as the flight trajectory is carried out.