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Problem. In the event of circumstances that may cause a traffic accident (accident), drivers apply emergency braking, which usually leads to the blocking of car wheels and the formation on the road surface of track information from pneumatic tires. If automated brake force control systems are installed in the brake actuator of the vehicle, the tracking information from the pneumatic tires may be absent or weak, and the braking efficiency of the wheeled vehicle will depend on the angular deformation of the tire relative to the road surface, which in turn is limited. coupling properties in the contact spot "tire-road surface". Goal. The aim of the work is to improve the method of determining the angle of twist of the pneumatic tire of a single car wheel in the mode of its braking by taking into account the effects of the coefficient of friction-sliding on roads with high traction. Methodology the peculiarities of twisting the pneumatic tire of a car wheel with a single busbar in the mode of vehicle braking on roads with low and high coefficient of friction - sliding are considered. The analysis of the model of dynamic change of the tire twist angle depending on the sliding of the tire tread elements in the spot of contact with the road surface is performed, and the results of simulation modeling are obtained, which are confirmed by experimental experiments. Originality. An empirical dependence is proposed, which takes into account the nature of the decrease in the value of the angle of twist of the tire on roads with high traction properties. Practical value. The obtained results of simulation modeling according to the proposed dependence determine that the highest indicators of torsional rigidity of the pneumatic tire are reached at a tire pressure of 0.8 MPa and a vertical load on it of about 2.6 104 N.

Objective: To determine the preoperative radiographic method for measuring the Cobb angle that is closest to the postoperative result in patients with scoliotic deformity. Methods: Retrospective cohort study of radiographic spinal evaluation (preoperative posteroanterior (PA), bending, traction, traction under anesthesia and immediate postoperative posteroanterior (PO)) of 26 patients treated surgically for scoliotic deformities during the period from January 2017 to September 2019. The final mean Cobb angle and its decrease in relation to the PA value were evaluated in the three curves in patients with idiopathic (IS) and non-idiopathic scoliosis. Results: All the mean curve values were statistically significant, except for bending in non-idiopathic scoliosis (non-IS). The mean traction under anesthesia values were closer to the PO values. Regarding the delta (decrease) of the maneuvers in relation to the PA, no statistical significance was observed in the non-IS group. The traction under anesthesia maneuver had a greater delta in all curves. Conclusions: The traction under anesthesia maneuver in patients with idiopathic scoliosis is the method with the greatest flexibility and which best predicts the postoperative result. Level of evidence III; Diagnostic study.

The shift in the way how health care is delivered from exclusive (disciplinary) to a more collective and inclusive (interprofessional) has recently been gaining traction in health care. The need for this shift is even magnified when the health care system face unprecedented challenges that single expertise is no more enough. The promise of transformative power of collaboration in health care suggests that collective intelligence achieves tasks more effectively than a single expertise could achieve.

Bone-patellar tendon-bone autograft for anterior cruciate ligament (ACL) reconstruction has the most data to support its use. However, there may still be room for improvement, and younger age, insufficient rehabilitation, altered neuromuscular patterns, and precocious return to play can increase risk of graft failure. High strength suture augmentation of soft-tissue repair or reconstruction has gained traction in a variety of applications for the knee, including medial collateral and posteromedial corner, lateral collateral ligament, posterior cruciate ligament, and ACL. For ACL reconstruction, the technique consists of using either suture or suture tape fixed at the femoral and tibial ACL footprints to allow for independent tensioning to back up the separately tensioned ACL reconstruction. The static augment serves as a load-sharing device, allowing the graft to see more strain during earlier levels of graft strain, until graft elongation occurs to a critical level whereby the augment will experience more strain than the graft. Hence, the “seat belt” analogy. This is distinct from static augmentation, where the high strength suture is fixed to the graft. Static augmentation (without tensioning separately from the graft) results in a load-sharing device and increased stiffness, but potential stress shielding compared with the “seat belt.” If suture tape augmentation improves patient outcome, it is a worthwhile to “click it.”

The use of longitudinal finite mixture models (FMMs) to identify latent classes of individuals following similar paths of temporal development is gaining traction in applied research. However, FMM's users may be unaware of how data features as well as the inappropriate specification of the model's covariance structure impacts class enumeration. To elucidate this, we investigated model fit-criteria curve behaviour across an array of data conditions and covariance structures. Fit statistic patterns were variable among the fit criteria and across a range of data conditions. This variability was greatly attributable to the level of class separation and the presence/absence of random effects. Our findings support some widely held notions (e.g. BIC outperforms other criteria) while debunking others (adding random effects is not always the solution). Based on the obtained results, we present guidelines on how the behaviour of fit criteria curves can be used as a diagnostic aid during class enumeration.

This letter proposes a novel compensation method to eliminate the impact of parasitic inductances on the measurement accuracy of on-state voltage of power semiconductor devices in operating converters. It is an online and noninvasive method by measuring the output current of inverter and on-state voltage of power device only. The impact of parasitic inductances and its compensation are verified experimentally through a traction inverter system.

During the first year of the new coronavirus (COVID-19) pandemic, more than 60 million people were infected. Of these, almost 20% had the consequences after it, the so-called “Post-COVID syndrome”, which manifests itself in various long-term painful symptoms. The causative agent of the disease, the coronavirus SARS-CoV-2, primarily affects the lung tissues and disrupts gas exchange that leads to acute respiratory distress syndrome, systemic hypoxia, when, first of all, the blood saturation system is destroyed. Severe complications of this infection require the active development of methods to eliminate and prevent the consequences of infection with coronavirus. Therefore, the search for effective rehabilitation method, especially of the respiratory system specifically after suffering from pneumonia caused by COVID-19, is extremely urgent. As a result of numerous studies, the possibility of using the method of normobaric interval hypoxic training was justified. At the same time, the respiratory surface and the number of alveoli in the lungs increase, the mass of the respiratory muscles increases and the neurons of the respiratory center hypertrophy occurs as a result of which the efficiency of the ventilation function increases. Inflammation in the lungs can last for several weeks and then fibrosis occurs in place of the damaged areas. This shows the absolute need for effective methods of rehabilitation, first of all, of the bronchopulmonary system after suffering from pneumonia caused by COVID-19. Interval hypoxic training, as an effective non-specific method of increasing the body’s defenses is indispensable in rehabilitation after viral pneumonia. It is shown that the combined use of interval hypoxic training and the method “Detensor” for the gentle long-term traction of spinal column can reduce or eliminate ventilation and perfusion disorders in chronic obstructive pulmonary disease. This justifies the possibility of using these methods for correction of bronchopulmonary disorders as a non-invasive and non-pharmacological support in the complex of rehabilitation measures for Post-COVID syndrome.

Background and study aims The pocket-creation method (PCM) facilitates dissection of the central part of a tumor. We previously developed the PCM with clip traction (PCM-CT) to facilitate opening the mucosal pocket, which otherwise could become cumbersome. In the present study, we aimed to examine the feasibility of PCM-CT for colorectal endoscopic submucosal dissection (ESD). Patients and methods PCM-CT was performed on 30 patients with early colorectal tumors from October 2019 to April 2020. PCM-CT allows efficient opening of the mucosal pocket by using the PCM to dissect the center of the lesion and then apply traction with a single clip after making a circumferential mucosal incision. Results The median specimen major axis length, ESD time, ESD speed, and en bloc resection rate were 48 mm, 84 minutes, 20 mm2/min, and 100 % (30/30), respectively. The success rates for the traction clip and median single-clip-traction time were 100 % (30/30) and 1.5 minutes, respectively. Conclusions Colorectal ESD using PCM-CT is a simple and promising method.

Purpose. The main purpose of the work is the development of identification models and a new method of modeling electromagnetic processes in electric traction systems with simultaneous consideration of all its subsystems, as well as several feeder zones of the electrified section. Methodology. To achieve this purpose, the methods of mathematical modelling, the basics of the theory of random processes and the methodology of their probabilistic-statistical processing, the methods for solving integral equations and analysis of electric traction circuits in electric traction systems are used. Findings. The requirements to be met by an adequate, stochastic identification model of electric traction devices are established. The solution of Fredholm’s integral correlation equation of the first kind is performed. The analytical expression of the identification dynamic model of the electric locomotive DE–1 is obtained and its adequacy is checked. The methodology of combined modeling of electromagnetic processes in devices and subsystems of electric traction systems is developed and presented tabularly. Originality. For the first time it is proposed to use the pulse transition function as identification models of traction substation and traction network with electric rolling stock in predictive modeling of electromagnetic and electric power processes in electric traction systems. A new method has been developed, a method of complex modeling of electromagnetic and electric power processes in the system of electric traction with simultaneous consideration of all its subsystems, as well as several inter-substation zones of the electrified section. For the first time, a method of partitioning the correlation functions for solving an integral correlation equation has been proposed, which allows defining a pulse transition function as an identification model of any subsystem of an electric traction system. Practical value. The developed identification models and the method of combined modeling make it possible to predict electromagnetic processes simultaneously in all feeder zones of the electrified section of the electric traction system. The obtained identification model of the electric locomotive DE–1 can be adapted with its subsequent use in modeling processes in the traction circuits of electric locomotives of other types. The method of factorization of correlation functions used in solving the Volterra integral correlation equation of the first kind (convolution type) can be adapted to the solution of other integral equations, which describe the processes in electric traction systems.

In order to improve fuzzy fatigue reliability and make weight reduction of A-type frame in an electric mining dump truck considering multi-source uncertainties from design, manufacturing and use stage, a multi-objectives optimization method based on the interval theory was proposed in this paper. The thickness of four steel plates in welded A-type frame was regarded as certain design variables, while the elastic modulus and density of material was considered as uncertain variables as well as the load at front traction joint. The relationship between optimization objectives and variables was constructed by the response surface method, and was transformed by the interval method. Then, the optimization problem was solved by the non-dominated sorting genetic algorithm, which was found that the fuzzy fatigue reliability reached up to 98.45 % at the expense of some weight.

Due to the high surface-to-bulk ratio, the classical continuum theory cannot accurately describe the mechanical behavior of the nanoscale structures. In this research, based on Gurtin–Murdoch surface stress theory and Kirchhoff plate model, a novel size-dependent formulation is presented for buckling and post-buckling behavior of thin symmetric porous nano-plates embedded into an elastic substrate medium. Using Hamilton’s principle, governing differential equation as well as corresponding boundary conditions is derived for rectangular porous nano-plates. For critical buckling traction and static equilibrium path, analytical solutions are developed including three case studies: simply supported porous nano-plate under biaxial tractions and uniform transverse load, simply-clamped supported porous nano-plate subjected to axial traction and uniform transverse load, and simply supported porous nano-plate under pure shear traction. In the numerical examples, effects of residual stress, surface elasticity, material porosity, and subgrade modulus are investigated for the critical buckling traction and the static equilibrium paths curves. Findings indicate that the residual stress has a significant influence on the buckling traction value and the form of the equilibrium path curve compared to the surface elasticity. Meanwhile, the buckling traction value of the nano-plate rises by reducing the material porosity and increasing the subgrade modulus.

The article considers existing regulated installations of transverse capacitive compensation for increasing the capacity of sections of the traction network of 25 and 2×25 kV of Russian railways. Characteristics of a static reactive power generator based on bipolar IGBT transistors (manufactured by LLC NPP “RU-Engineering”, Naberezhnye Chelny), a switchable filtercompensating unit (manufactured by the Gorkovskaya Railway and the Nizhny Novgorod branch of SamGUPS), a three-stage switchable filter-compensating unit. To increase the capacity, all installations are switched on at the traction network sectioning posts. Long-term operation of the static reactive power generator and switchable filter-compensating unit have proven their operational efficiency. At the same time, the following upgrades are proposed: in a static reactive power generator it is proposed to reduce the installed power, replacing it with unregulated compensation, and in a switchable filter-compensating installation, it is proposed to switch in 400–500 V steps to normalize the traction mode of the electric rolling stock.It is shown that in terms of technical characteristics, a switchable filter-compensating installation with a thyristor switch is not inferior to a static generator of reactive power in terms of increasing the capacity, and in some respects it surpasses it. On the whole, in terms of payback period, a switchable filter-compensating installation surpasses a static generator of reactive power due to the high cost of the latter. The following options for using the considered installations are proposed. With the required power of transverse capacitive compensation units up to 5–6 MVAr, to increase the capacity, switchable filter-compensating units should be installed. Taking into account real loads, such a solution will be implemented at most sectioning posts. For installations with a capacity of more than 5–6 MVAr, the option of using a static reactive power generator of reduced power should be considered: at high loads, its efficiency will increase.

Traction Is Part Of The Evidence Based Manual Physical Therapy Management Due To Its Mechanical Nature. The Efficacy Of Lumbar Traction (Lt) Has Been Established, Lt As The Most Used Method Of Spinal Decompression Therapy (Sdt) Reduces The Intradiscal Pressure And Vertically Increases The Intervertebral Space And Restore Disc Height Allowing Nutrients And Oxygen Supply To The Disc. While Lt Had Recently Been Used As A Conservative Treatment For Chronic Lumbar Disc Herniation (Cldh), Combined Lumbar Traction With Cervical Traction (Cltct) As One Intervention Which Has Been Suggested By (Al-Qudah, M.K) Was Used As A Part Of Rehabilitative Program In Patients With Cldh. Therefore, The Effectiveness Of Cltct Separately At Any Other Interventions Remains Absolutely Unclear And Uncertain. Objective: The Aim Of The Presented Work Is To Identify The Effectiveness Of Cltct [(Positional Sustained Lumbar Traction (Pslt) Combined With Mechanical Sustained Cervical Traction (Msct) As One Intervention] On Patients With Moderate (L4-L5) (L5-S1) Cldh, And To Compare Cltct With Traditional Mechanical Lumbar Traction (Mlt). Methods: In This Study, Twelve Outdoor Male Patients Diagnosed With Magnetic Resonance Imaging (Mri), Had Accepted To Participate The Study. They Were Chosen From Al-Karak Governmental Hospital, From 20th Of December To 1st February 2021. Subjects Were Divided Randomly In To Two Groups, Experimental Group (N=6) Performed Cupping Massage (Cm), Cltct And Core Stabilization Exercise (Cse), While The Control Group (N=6) Performed Cm, Mlt And Cse. All Subjects Were Advised To Perform The Cse Three Times Daily As A Home Program In Addition To One Set During Each Session Under The Therapist Supervision. All Subjects Had Exposed (18) Sessions For (6) Weeks. The Results Were Analyzed Using The Spss System. Results: Indicates That There Was Statistically Significant Difference Between The Pre And Post Measurements In Both Groups In Favor Of The Post Measurements In Term Of Pain And Disability. Also Results Indicate That There Was Statistically Significant Difference Between The Groups In Favor Of Experimental Group. Conclusions: The Present Study Demonstrates That The Use Of Cltct Has A Positive Effect On Patients With Cldh More Than Mlt.

In this paper, a system for controlling the energy flow of vehicle with multiple energy storages which are used for increasing performance and driving range is presented. For achieving maximal performance and efficiency of energy flow control, traction profile of the route is necessarily known. For observation of a traction profile, Global Navigation Satellite System is used. For energy flow control, three algorithms are presented. The first proposed algorithm uses the whole traction profile of a predetermined route by the driver so the control algorithm can decide the energy of the second energy storage efficient. The second algorithm eliminates the biggest disadvantage of predetermining route, so the algorithm uses traction profile from the memory of stored routes where the vehicle was already driven. If the route was not defined or found in memory energy of secondary energy storage, (supercapacitor) using will be based on the current of primary energy storage (batteries). For verification of proposal algorithms for control of DC/DC converter which is used for energy flow control, inverter and motor were simulated with programmable load and programmable power supply.

Goal. The goal of the research is to develop an algorithm for selecting the main dimensions of a traction permanent magnet-assisted synchronous reluctance motor. Methodology. A method for determining the main dimensions of the motor, which combines the analytical selection of stator parameters and numerical field calculations for the selection of rotor parameters. The need to check the mechanical strength of a rotor with permanent NdFeB magnets in flux barriers is shown. Results. The article proposes an algorithm for selecting the main dimensions of a traction permanent magnet-assisted synchronous reluctance motor, which combines analytical expressions for selecting stator parameters and numerical field calculations for selecting rotor parameters. It is determined that analytical methods for calculating the magnetic circuit need to be developed in order to reduce the time to select the main dimensions of the motor. Originality. For the first time the sizes of active parts of the permanent magnet-assisted synchronous reluctance motor with power of 180 kW for the drive of wheels of the trolleybus are defined. Practical significance. As a result of research the sizes of active parts, stator winding data and a design of a rotor of the electric motor are defined. The obtained results can be applied when creating an electric motor for a trolleybus., У статті розглянуті питання проектування тягового синхронно-реактивного електродвигуна з постійними магнітами потужністю 180 кВт для приводу коліс тролейбуса. Запропоновано спосіб визначення головних розмірів електродвигуна, який поєднує аналітичний вибір параметрів статора та чисельно-польові розрахунки для вибору параметрів ротора. Показана необхідність перевірки механічної міцності ротора, в якому розташовано постійні магніти NdFeB у потокових бар’єрах. У результаті дослідження визначено розміри активних частин, обмоткові дані статора та конструктив ротора електродвигуна.

Approximately 2.5 billion won can be saved every year by replacing existing induction motors, which are traction motors for urban railway vehicles, with permanent magnet motors. This paper presents a study on the structural design of a completely enclosed motor to commercialize an interior permanent-magnet synchronous motor (IPMSM) for the traction of urban railway vehicles. The proposed solution provides protection from an inflow of dust and magnetic powder into the rotor that can deteriorate the motor performance and cause burnout. In addition, unless it is a water-cooled or oil-cooled structure, cooling of an electric motor used in medium and large-sized equipment is not easily accomplished. However, completely enclosed motors are vulnerable to overheating; therefore, research into housing design is required to provide cooling. Additionally, the permissible current density through the stator winding must be considered in the design to prevent the occurrence of thermal demagnetization of permanent magnets. Furthermore, IPMSMs require a separate driver for operation and speed controls for a wide range of operating conditions such as rail traction. Thus, a study has been conducted on IPMSMs and other related driver and control technologies, and their suitability has been validated through performance tests.

Femur fracture is a fracture in the largest bone in the body. The femur requires significant force to fracture. One of the treatments for femoral fracture is reduction and immobilization using traction. Immobilization in traction-attached patients before preoperatively requires isometric exercises to maintain muscle strength. Isometric exercise is a muscle contraction exercise, the patient contracts the muscles without moving the muscles to maintain muscle and prevent atrophy. The purpose of this paper is to identify the effectiveness of isometric exercises to increase isometric muscle strength in patients with lower limb fracture. The methodology used is a case study. The application of isometric exercises can increase muscle strength in patients with skin traction attached. Nurses need to pay attention to factors that can affect the patient's ability to perform isometric exercises so that the results obtained can be more optimal and the patient experiences an increase in the ability of his limbs. Keywords : Isometric Exercises; Muscle Strength, lower limb fracture

Agritourism has gained traction with a variety of stakeholders within the Pacific to supplement farm revenue, create linkages to tourism and ultimately contribute to sustainable economic development. This paper, with a focus on smallholders, examines the key constraints of agriculture, current agritourism products, policy development initiatives, and proposes an open framework for agritourism in Fiji. Among the key considerations are a careful examination of tourist preferences, the promotion of agritourism on working farms without displacing the key activity of food production, and redefining agritourism as a value for money experience rather than a niche market in the Pacific region.

Head-end trains are more efficient than Distributed Power trains in terms of train marshalling. This paper studied an unprecedent real-world engineering problem to hill-start a long heavy haul train at a 1.2% up-hill gradient by using a 14400 kW 24-axle AC electric locomotive (maximum traction force 2280 kN). Longitudinal Train Dynamics simulation were conducted to assess five potential driving strategies in terms of train speed and in-train forces. The simulation results show that the locomotive can hill-start the heavy haul train with 80% traction throttle. However, maximum locomotive coupler forces (1840 kN) exceeded coupler knuckle yield strength (1780 kN) of the original coupler system design. Sensitivity analyses were conducted to assess the implications of train starting resistance for train speeds and in-train forces. The study recommends increasing coupler knuckle yield strength to 2450 kN. The increased knuckle yield strength is still lower than that of the chassis, which is able to meet system design requirement; it also enables the locomotive to hill-start by using traction throttles of 80, 90, and 100% with safety factors of 1.3, 1.2 and 1.1 respectively.

Introduction. The power analysis of a chain transmission with a toothed chain and involute sprockets considers the centrifugal forces and the friction coefficients between the plate and the sprocket tooth. The work objectives are to determine all meshing forces, and to calculate the coupling coefficient of the gear chain with the involute sprocket in the drive gears. Materials and Methods. When evaluating the traction capacity of a chain transmission, such parameters as the power analysis and the coupling coefficient of the gear chain with the sprocket are important (it shows what fold the pressure on a given tooth is greater than the pressure perceived by the tooth in front). In the presented paper, the following diagrams are visualized: the arrangement of the plates in gearing with the involute sprocket teeth and the meshing forces. The factors that affect the involute profile of the sprocket tooth are considered. This includes the weight of the chain plate package and the force: centrifugal, friction, normal pressure and tension. At the same time, changes in the coupling coefficient for the subsequent teeth involved in traction are taken into account. The balance of the links i and i + 1 of the gear chain is studied in the coordinate system XOY with the center on the axis of rotation of the involute sprocket. The method enables to determine all the desired forces through the geometric calculation of the values of the angular transmission parameters. Using the equations obtained, the following parameters are specified: the coupling coefficient B i , the tension of the driving branch S 1 and the slack branch S 2 . Results. A patented transmission stand with a gear chain and involute sprockets is presented. The tests carried out on it validated the study results of a chain transmission with a toothed gear and involute sprockets with the specified parameters. The correctness of the power analysis of the transmission with account for the centrifugal forces and the friction coefficients of the plates and the sprocket teeth was proved. Discussion and Conclusions. It is noted that the centrifugal forces and the friction coefficients during engagement affect significantly the traction capacity of a transmission with a toothed chain and involute sprockets. The data obtained can be used to accurately estimate the traction capacity of such gears.

In addition to obtaining necessary dynamic characteristics and broadly using modern solid-state traction converters, intensified electric rolling stock (ERS) traffic flow and increased travel speeds have a significant influence on the catenary system and cause voltage dips and surges. This article considers the possibility of stabilizing the voltage of a catenary system section by means of an automatic voltage stabilizer that uses the energy accumulated in an electricity storage device. This stabilizer is designed as a reversible solid-state converter used to charge and discharge the energy storage device. The proposed formulas are used to make up a mathematical model the main strength of which is the usage of real data collected from urban ERS traffic flows. The test results show that a voltage stabilizer using the energy of the storage device can reduce the influence of ERS on the catenary system voltage.

The widespread use of green public transport is a priority strategy to reduce a congestion and pollution from road traffic in many cities. The trolleybus is a type of urban public electric transport, which is considered as a promising tool for increasing the efficiency of public transport and achieving the goals of sustainable development and quality of life in the city. The operation control of service brake system and secondary brake system (braking torque of traction electric motor) is realized with the help of one pedal in the trolleybus. Thus, there are modes of joint operation for these systems during the braking process. The author has focused his main attention on the development of an algorithm for blending control of the traction electric motor and the anti-lock braking system to enhance the overall braking efficiency of a vehicle. For this purpose, a mathematical model of the trolleybus braking dynamics has been developed. Bench and road tests have been carried out on various road surfaces to determine parameters of vehicle braking efficiency and to validate the developed mathematical model. The corresponding experimental data were used to analyse the efficiency of the proposed strategy for combining the blending control of traction electric motor and anti-lock braking system of the trolleybus. As a result, the efficiency of the proposed control algorithm has been confirmed, which provides the required braking efficiency and high braking stability of the vehicle.

Granular media, like sand, restricts vehicle traction and degrades the ability of mobile robots to pull loads. Solutions that are effective on hard or clean surfaces fail on sand. This work presents a mobile robot system that utilizes an active tail to greatly increase its ability to pull loads. The robot combines dynamic tail impacts, plowing, and leveraging of cable tension to achieve this improved performance. The key contributions of this letter are 1) illustrating how dynamic impacts can provide substantial anchoring force on two terrain types, 2) incorporating anchoring behavior into tail actuator design, 3) combining tail and wheel behaviors to create granular barriers, 4) leveraging geometry to utilize winch tension for enhanced performance, and 5) experimentally demonstrating the ability to transport loads 6x the robot mass on a deep sandy surface. The prototype 7.6 kg robot was able to pull a 45.5 kg load on a deep sand surface. This is a substantial improvement over the baseline robot which was only able to pull a 13.6 kg load.

Highlight • The largest and first study to compare EIN with CST for displaced tibial shaft fracture in a Chinese population. • The CST procedure had faster surgical time, cast duration, and longer hospitalization. Patients in EIN group began exercising and endured weight-bearing earlier. • The CST provided better results of coronal correction than EIN. Moreover, CST patients had less malalignment (> 5°) in complications. • The characteristics of the patient and fracture, the individual's situation and expectation should be considered when choosing the best approach., Background The objective of this study was to compare the outcomes and complications of patients who underwent either the calcaneal skeletal traction (CST) or the elastic intramedullary nails (EIN) procedure. Methods We retrospectively reviewed data of patients who underwent EIN or CST surgery for tibia shaft fracture at our center from 2013 to 2018. The patient demographics, fracture characteristics, radiographic information, length of hospital stay, and medical expenses were recorded. All patients were clinically followed-up until they started to walk or for at least 6 months. The treatment outcomes and postoperative complications of the two procedures were compared. Results Overall, 186 patients who underwent EIN and CST were included in the study. The EIN patients had more low-energy mechanism of injury. In radiographic evaluation, significant differences were observed in distributions of fracture classification and location. Moreover, associated fibula fractures were higher in the EIN group than in the CST group. The CST procedure had faster surgical time, cast duration and lower expenses, and longer hospitalization time. Although they required more clinical visits, patients in the EIN group began exercising and endured weight-bearing earlier than those in the CST group. The average time for bone healing was 68.5 days in the EIN group, and 69.6 days in the CST group. However, the CST provided slight better results of coronal correction than EIN. Moreover, CST patients had less malalignment (> 5°) in complications. None had delay union, nonunion, and shortening over 10 mm at final assessment. Conclusions Both EIN and CST patients showed similar treatment outcomes. Hence, not only the characteristics of the patient and fracture, but also the individual's situation and expectation should be considered when choosing the best approach.

Based on analysis of the problem of the power supply networks of railways innovative transformation, the direction of research is substantiated related to organization of the optimal strategy of computerized intellectualization of the power supply processes to the railways traction substations. The logical structure of a distributed computer environment developed in the form of graph, which adequately reflects the topology of the organization of the power supply system. A differential mathematical model of the computer architecture of the power supply control is proposed. An intelligent method for finding the optimal strategy for the intellectualization of the power supply processes was proposed to guarantee the specified indicators of the optimal functioning of individual nodes and segments of the power supply management computer network.

The integration of nine-phase permanent magnet synchronous machines (nine-phase PMSMs), employed in on-board integrated battery charger for electric vehicles (EVs), into three-phase grid generates an inevitable torque fluctuation in charging and vehicles to grid (V2G) modes. This undesirable torque, which is the source of motor vibration and noise, is due to the interaction among the zero-sequence current, triplen harmonics (third and ninth) of induced back electromotive force, and rotor position. In this article, a new solution for nine-winding integrated battery chargers of EVs is considered. A segmented three-phase PMSM with nine windings is used to replace the nine-phase PMSMs. With this configuration, the system has the advantage of torque-free in charging/V2G mode, low core loss, and simple control (based on the three-phase control) in both traction and charging/V2G modes, with the privilege of employing the reduced number of sensor and with no additional new elements. Through proper three-phase control strategy, the system operates under unity power factor with total harmonic distortion below 5%. Control strategies for charging, V2G, and motoring are given; moreover, the simulation and experimental results are provided to validate the theoretical analysis.

Separated overfire air (SOFA) is typically employed in coal-fired boilers with air staged technology to sustain lower NOX emission, and SOFA nozzle angles are crucial adjustment parameters. In this work, the combined effects of SOFA yaw and tilt angles on combustion characteristics were numerically investigated for a 1,000 MW dual circle tangentially coal-fired boiler. Numerical results show that the forward increase of the SOFA yaw angle from 0° brings about the enlarged SOFA tangential circle and the gradual appearance of bimodal high-temperature zones at furnace exit. With further tuning SOFA tilt angles vertically, the bimodal high-temperature zones would separate to the two halves of the furnace, inducing a more severe deviation of gas temperature. Besides, the gas residual rotating momentum is strengthened as SOFA yaw angles forward increase, resulting in the enhancement of traction effect in the upper furnace as well as the rise of flame. However, the gas velocity deviation is somewhat eliminated as SOFA rotates reversely. No matter that the SOFA yaw angle increases forward or reversely, the coal burnout would deteriorate with the overly enlarged SOFA tangential circles. Tuning SOFA yaw and tilt angles, respectively, at 5° and 0° can simultaneously guarantee lower CO and NOX emissions.

Terramechanics plays an important role in determining the design and control of autonomous robots and other vehicles that move on granular surfaces. Traction capabilities, slippage, and sinkage of a robot are governed by the interaction of a robot’s appendage with the operating terrain. It is important to understand how the terrain flows under this appendage during such an interaction. In this work, dynamics of soil performance and locomotion performance of a lugged wheel travelling on soft soil are numerically investigated. Studies are conducted with a two-dimensional model by using the discrete element method to analyze the interactions between a lugged wheel and the soil. The soil performance is studied by examining the force distribution and evolution of force networks during the course of the wheel travel. For two different control modes, namely, slip-based wheel control and angular velocity-based wheel control, the performance parameters such as, sinkage, traction, traction efficiency, and power consumption of the wheel are compared for various wheel configurations. The findings of this work are expected to be useful for optimal design and control of the lugged wheel travelling on deformable surfaces.

Liquid biopsy is rapidly gaining traction for potentially revolutionizing cancer diagnosis and treatment through blood-based utilization of shed biomolecules. This approach can provide a global picture of the cancer in real time, at multiple time points, and with minimal invasiveness. In this review, we familiarize cancer biobanks with the principles used for liquid biopsy work and highlight unique aspects of applying liquid biopsy approaches to pediatric cancers to enable high-quality and efficient translational research.

Single-phase matrix converters (MCs) are undergoing rapid developments due to their bipolar voltage gain (as required in dynamic voltage restorers) and step-changed frequency operation (used in high step-up ac–dc rectifiers, and to provide medium frequency isolation in traction and wind turbine converters, etc.). However, existing buck–boost MCs require high-voltage/current rating devices, and suffer from large component voltage/current stresses and ripples, significantly degrading their efficiency. This article proposes a highly efficient single-phase buck–boost MC; consisting of eight IGBTs (implemented using two full-bridge IGBT modules), second-order input and output filters, and a small value film capacitor. Efficient discrete inverting and noninverting buck and boost operations are proposed (same as that of sixteen-switch cascaded buck–boost MC) with significantly lower component voltage/current stresses and ripples. In addition, flexible inverting and noninverting buck–boost operations are proposed with independent control of buck and boost duty ratios. All of the proposed operations are free of commutation issues, compatible with reactive loads, and provide smooth input and output currents. Furthermore, all the switches have same voltage stresses, and all four switches in a full-bridge module experience the same current stresses. A comprehensive description of circuit operation is presented based on a number of proposed switch modulation strategies with a nonunity power factor load, followed by design guidelines, and comparative evaluations with existing topologies. Finally, experimental verification results are presented, using a 400-VA laboratory prototype converter.

With the rapid development of high-speed and heavy-load electrified railway, the peak impact and the regenerative braking energy content of traction load become increasingly significant, which has become an important problem affecting the construction and operation benefits of electrified railway. On the basis of comprehensively solving the power quality problems of electrified railway, a multi-application strategy based on the railway static power conditioner (RPC) with the energy storage system (ESS) is proposed in this paper to improve the economic benefits of the traction system. Through the implementation of the peak clipping and the recuperation and utilization of regenerative braking energy of traction load with the guidance of such strategy, the comprehensive economic benefits of the traction system can be improved. By analyzing the mathematical relationship between the comprehensive economic benefits and the parameters such as peak clipping rate and regenerative braking energy utilization rate of the system, an optimization model with the goal of maximizing the comprehensive economic benefits is established. Therefore, the optimal configuration capacity of the ESS is obtained. Finally, the experiments are carried out in MATLAB. The results show that, with the multi-application strategy, the peak load clipping and the recuperation and utilization of regenerative braking energy can be simultaneously realized. It is also demonstrated that the comprehensive economic benefits and environmental benefits can be improved while improving energy efficiency.

In Russia, more than 24 thousand km of railways are electrified with alternating current. To carry out transportation in freight and passenger traffic, electric locomotives and electric trains equipped with rectifier–inverter converters are used. Technically speaking, the set of electrical equipment is a multizone bridge rectifier operating with an active–inductive load. One of the main disadvantages of such a scheme is low power factor. When determining the final value of the power factor, three factors must be taken into account: the magnitude of the rectified current ripples, nonsinusoidality, and the duration of switching. In this paper, the main expressions for determining the duration of switching during the operation of a rectifier–inverter converter for an ac traction rolling stock are obtained and the electrical parameters of the traction transformer windings are calculated.

En la actualidad, los materiales compuestos de matriz polimérica son utilizados en múltiples aplicaciones, una de las áreas más importantes de aplicación es en el sector aeronáutico, debido a la relativamente baja densidad que tienen los materiales combinados. Estos compuestos tienen buenas propiedades mecánicas, comparables con materiales metálicos, pero que aportan beneficios adicionales. El objetivo de este trabajo es hacer los ensayos experimentales y el análisis numérico de la estructura del material compuesto alternativo para emplearlos en la reparación de las superficies de vuelo de aeronaves del CIDFAE. Se manejó un proceso ampliamente extendido de envasado al vacío (vacuum bagging) para obtener un compuesto más homogéneo, Lo que redujo los defectos en el procesamiento, y controló mejor la fracción de las fibras y el espesor global del compuesto. Se elaboraron probetas de resina epóxica reforzada con capas de tejido plano de tres fibras distintas de: carbono, vidrio y aramida, en diferentes orientaciones, que fueron ensayadas a tracción, flexión e impacto para determinar sus propiedades mecánicas. Se ha demostrado que los resultados conseguidos mediante la metodología analítica y el método de elementos finitos son aproximados a los resultados que se obtienen con ensayos destructivos. Los resultados experimentales muestran que los valores de resistencia a la tracción son mayores en los materiales de resina epóxica reforzados con 4 capas de fibra de carbono en orientación 0°-90°.

Currently the circuit technology of the DC traction power supply system cannot provide the necessary requirements for introduction of high-speed traffic. Numbers of measures and tools have been developed to improve the traction lines that no longer meet current requirements. One of the most promising means for strengthening the traction DC lines is transition to the distributed power supply of the rolling stock. In this article, a comparative analysis was carried out of energy indicators of the classic centralized power system and distributed power systems with use of one aggregate traction substation and with use of the solar generators. That comparative analysis of these systems was performed on a simulation model with the same parameters of the traction line and rolling stock.

In this paper we solve the problem of synthesizing a power regulator in a traction electric drive system using artificial neural networks. To control the vehicle and obtain the desired quality of transients, neural network observers have been developed that allow the measurement of indirect parameters to determine the immutable coordinates of the system. For this purpose, this paper uses dynamic neural networks. When developing the neural network observer, experimental data obtained by the authors on an operating vehicle in real operating conditions are used. To test the effectiveness of using the created artificial neural network, an object is simulated with a random nature of the supply voltage change. A comparative analysis of transients in a system with a power neuroregulator and classical regulators in a subordinate control system shows a fairly high convergence of the results

For organization of power supply of devices for monitoring and accounting of electric energy for railway traction networks of direct current, the topology of the power source based on a serial chain of voltage converters can be used. The paper considers the development of a methodology for the electrical calculation of such sources. For this purpose, lists of initial data and calculation results are formed. A substitution scheme of ideal elements is proposed. The operation of the substitution scheme is analyzed using the «equivalent source» method. It also provides formulas and recommendations for selecting and determining the required parameters. The adequacy of the proposed method is confirmed by a full-scale experiment

In this paper, the effect of traction speed on the four-lumen plastic micro-catheter (FLPMC) was numerically studied. Moreover, the numerical simulations of FLPMC based on two kinds of extrusions, i.e., traditional extrusion and gas-assisted extrusion were performed and compared. Numerical results show that with the increase of traction speed, the sizes of FLPMC for both extrusions all decrease. The sizes of FLPMC based on gas-assisted extrusion are sightly larger than those of the traditional extrusion. To ascertain the reasons, the flow velocities, pressure, shear stress and first normal stress difference distributions of melt based on both extrusions under two different traction speeds were obtained and compared. Results show that with the increase of traction speed under the fixed volume inlet flow rate, the radial flow velocities of melt at the outlet of die decrease but the axial flow velocities increase, which results in the decrease of the die swell at the outlet of die and the size shrinkage of exit face for the FLPMC based on both extrusions. However, for the gas-assisted extrusion, the axial velocities are larger, and the pressure, shear stress and first normal stress difference are far less than those of traditional extrusion, which results in the larger unit volume flow rate, then the sizes of cross-section face are larger than those of the traditional extrusion.

When reliability requirements at the stage of developing complex technical systems are setting, the total number of individual and complex reliability indicators set in accordance with regulatory documents is within 5-7 units. This is done provided that they are recoverable, and also for them the requirements for durability and preservation are determined. All this determines the complexity of the procedure for their verification, confirmation and evaluation. Aim: Formation of a common (integral) indicator of reliability, which can characterize the basic reliability properties multitude of traction electrical equipment, as a complex technical system, subject to the compliance of individual indicators with the requirements specified in the terms of reference. Methods: It is proposed to use of T. Saati's hierarchy analysis method, which is widely used in solving various multicriteria problems. Conclusion: Using an integral indicator to determine the level of reliability allows getting a formalized result, expressed through the vectors of global priorities corresponding value, which makes it possible to get a quantitative assessment of the superiority for one of alternative traction electrical equipment.

Introduction.A continuous action unit for the formation of an underlying layer is designed to increase productivity in the construction of roads and other facilities, for which it is necessary to remove the top layer of soil. In the bucket of the continuous action unit to form an underlying layer of roads provides the use of working bodies, cutting the ground with blades of knives. The cut-off soil enters the buckets. The forces attached to the bucket are considered. Theoretically reasonable total energy costs for ground cutting of one cubic meter by buckets of continuous action unit to form an underlying layer of roads requires 109 kilojoules. Based on the calculations carried out, it is possible to determine the torque, the power required for the lower drive, the transmission ratio from the hydraulic motor to the stars, to develop the design of many elements of the continuous action unit to form the underlying layer of the road.The method of research. To determine the torque, the power required for the lower drive, the transmission ratio from the hydraulic motor to the asterisks, to the projection of the bucket on the horizontal plane attached all forces are applied directed along the bucket. As a result of their addition, the total maximum traction force of moving all the boilers during their filling with soil was revealed. On the basis of this, the method of calculating the parameters of the required is given. There is a danger of the ground being poured out of the bucket when it is rotated on the leading stars of the lower drive. To check the parameters received, the bucket is rotated by 90 degrees on the leading stars of the lower drive. The forces acting on the ground, located in the bucket, at the moment of the beginning of the turn of the bucket were revealed. A system of equations has been created, on the basis of which the condition of inadmissibility of the dumping of soil from the bucket at its turn on the leading stars has been established.Results.As a result of the addition of forces directed in the course of the bucket, the total maximum traction force of moving all the boilers during their filling with the ground, traction force on the right chain and left chain is defined. Traction chains are chosen by destructive load. The torque of the lower drive, the angular speed of the drive stars, the power required for the lower drive, the transmission ratio from the hydraulic motor to the asterisk are calculated. Based on the transferable power, a gerotor motor is chosen for the lower drive of the unit. On the basis of the calculations the design of chains, support rink, chain suspension have been developed.Conclusion.Based on the calculations made, the maximum traction force of all the buckets during the period when they are filled with soil is 11,870 newtons, the torque of the lower drive is 2,362 newtonometers, the speed of the chains is 1,686 meters per second, the angular velocity of the drive stars is 8,47 radians per second, power required for lower drive is 20 kilowatts. Based on the transferable power, it is advisable to use MT-160 gerotor motor and a single-stage planetary gearbox with a transmission ratio from the hydraulic motor to the stars 7,674. The calculations made it possible to develop the design of many elements of the continuous action unit to form an underlying layer of roads.

Traction power fluctuations have economic and environmental effects on high-speed railway system (HSRS). The combination of energy storage system (ESS) and HSRS shows a promising potential for utilization of regenerative braking energy and peak shaving and valley filling. This paper studies a hybrid energy storage system (HESS) for traction substation (TS) which integrates super-capacitor (SC) and vanadium redox battery (VRB). According to the characteristics of the traction load under actual operating conditions, an energy management strategy with fixed-period control (FPC) is proposed, which fully leverages the periodicity and regularity of HSRS operation. To achieve the optimal size, economic feasibility is selected as the optimization objective, which is fully assessed in terms of Net Present Value (NPV). The optimization constraints are formulated in which the Discrete Fourier Transform (DFT) is performed for power allocation between SC and VRB. Besides, an improved mutation-based particle swarm optimization (IMBPSO) is proposed to efficiently solve the optimization and enhance convergence performance. Finally, combined with the measured traction load data, the effectiveness of the FPC energy management strategy is verified and the optimal scale of the HESS is provided.

In this study, an optimal-traction sheave is designed to prevent slip for a two-degrees-of-freedom facade-cleaning robot called Dual Ascender Robot (DAR). The DAR uses the length of the rope to estimate its position. Therefore, if a slip occurs, it becomes difficult to measure the length of the rope, thereby making it difficult to estimate position. Problems with position estimation may also cause difficulties in achieving control. The redesigned traction sheave was thoroughly evaluated by experiments. A well-known Taguchi method was used as the experimental procedure, and the optimal design parameters of the sheave were determined as hoop direction groove shape of 0.8, axial direction groove pitch of 6°, and axial direction groove depth of 2 mm. Verification experiments comparing the traction sheave with the optimal condition to that used in DAR showed improved performance. Therefore, it is expected that applying the optimal traction sheave to a DAR in further studies would help achieve better position estimation by preventing slips.

Specifications of up-todate traction class 2 agricultural tractors are analyzed, their distinctive features are identified and the engineering level is assessed.

Wheel/rail dynamic interactions of heavy-haul locomotives are highly nonlinear and complicated due to large traction/braking loads, frequent anti-slip control and complex wheel/rail interface envir...

Accepted: 2021-02-20, 資料番号: PA2110040000

The article considers variants of different forces that can occur during operation in linear electric motors with synchronous traction in high-speed ground transport. The main forces that exert external forces on the crew in the lateral direction are determined. In order to ensure safe operation of the crews, the article proposes to compensate the guiding forces of non-contact interaction of superconducting electromagnets on the crew by lateral forces, which in turn can act as excitation of synchronous motors with current-conducting track elements. Constructive combined systems of synchronous traction and direction with suspension system implemented abroad are analyzed. Detailed schemes of winding connection of combined systems of synchronous traction and direction are offered. Mathematical apparatus for calculation of guiding forces in case of application of combined systems of synchronous traction and direction are offered in the article. Calculation-theoretical analysis of different constructive combined systems of synchronous traction and direction has been carried out, as a result of which the vertical type of combined systems of synchronous traction and direction with wave winding in the path has been chosen more preferably. This choice is optimal for energy performance and material consumption for the track winding. A scheme of the combined synchronous traction and direction system with a suspension system in linear traction motors is proposed, with a description of the main elements of the design. Traction and levitation forces are determined by the interaction, and the drawbacks of electrodynamic suspension systems in the form of weakly damped oscillations under various perturbations are also noted. To solve this problem, it is proposed to include a damping coil, which is rigidly connected to the levitating coil in the scheme of synchronous traction and direction to provide damping of the oscillatory process.

Sectarianisation, a conceptual approach proposed by Nader Hashemi and Danny Postel, has gained a great deal of traction in the study of sectarianism in the contemporary Middle East. Yet despite its popularity, little attention has been paid to the ways in which sectarianisation can operate beyond the Middle East, a peculiar point when considering that only 20% of the world’s 1.57 billion Muslims live in the region. This brief intervention explores the ways in which the sectarianisation thesis can operate beyond the Middle East, looking at some of the ontological, epistemological, and methodological questions that are bound up in such an approach. Ultimately, I argue that while sectarianism has become a prominent feature in academic discussions about the Middle East – driven recently by a focus on sectarianisation – there is merit in exploring the application of Hashemi and Postel’s thesis in regions beyond the Middle East.

We demonstrate the ability of a stabilized finite element method, inspired by the weighted Nitsche approach, to alleviate spurious traction oscillations at interlaminar interfaces during composite ...

Using high-resolution imaging, such as optical coherence tomography (OCT), the different layers of the retina as well as the vitreoretinal interface and its alterations can be very clearly differentiated. This includes the morphological characteristics of tractive maculopathies, such as epiretinal gliosis and vitreomacular traction syndrome. Additionally, structural alterations of the various layers of the neurosensory retina as a result of traction due to these pathologies can be demarcated. The latter have been investigated in clinical trials and evaluated as OCT biomarkers with respect to their prognostic and predictive value. In this review we would like to present and discuss various OCT biomarkers in the context of epimacular membranes and vitreomacular traction syndrome.