On the Polygonal Wear Evolution of Heavy-Haul Locomotive Wheels due to Wheel/Rail Flexibility and Its Mitigation Measures

Wheel polygonal wear can immensely worsen wheel/rail interactions and vibration performances of the train and track,and ultimately,lead to the shortening of service life of railway components.At present,wheel/rail medium-or high-frequency frictional interactions are perceived as an essential reason of the high-order polygonal wear of railway wheels,which are potentially resulted by the flexible deformations of the train/track system or other external excitations.In this work,the effect of wheel/rail flexibility on polygonal wear evolution of heavy-haul locomotive wheels is explored with aid of the long-term wheel polygonal wear evolution simulations,in which different flexible modeling of the heavy-haul wheel/rail coupled system is implemented.Further,the mitigation measures for the polygonal wear of heavy-haul locomotive wheels are discussed.The results point out that the evolution of polygonal wear of heavy-haul locomotive wheels can be veritably simulated with consideration of the flexible effect of both wheelset and rails.Execution of mixed-line operation of heavy-haul trains and application of multicut wheel re-profiling can effectively reduce the development of wheel polygonal wear.This research can provide a deep-going understanding of polygonal wear evolution mechanism of heavy-haul locomotive wheels and its mitigation measures.

Research on uninterruptable power supply technology for auxiliary winding of electric locomotive while passing the neutral section

Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters.Powered by DC-link voltage of traction converters,the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking.Meanwhile,powered by traction transformers,the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.Design/methodology/approach–Uninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied.Failure reasons why previous solutions cannot be realized are analyzed.An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper.The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive.This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.Findings–This scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid.Control objectives of uninterrupted power supply technology are proposed,which are no overvoltage,no overcurrent and uninterrupted power supply.Originality/value–The control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section.Furthermore,this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware.

Drag reducing nose fairings for existing freight train locomotives

At cruising speed,one of the most significant contributing factors to train fuel consumption is aerodynamic drag,and the leading locomotive experiences much more drag than any other car in the train.This work reports on the drag reduction that can be realized by the use of add-on nose fairings that are deployed on leading locomotives in a train set.Two types of fairing shapes were considered and all fairing walls are flat.It is anticipated that the fairing shapes would result from the deployment of easily stowed panels in an origami inspired manner.One of the fairing shapes has the appearance of a wedge and the other fairing is also wedge shaped,but with flow directing side wall features.For each general fairing shape,the important dimensions were parametrically varied in a systematic manner to identify the dimensions that yield maximum drag reduction.For the first shape,45 different scenarios were considered;for the second shape,15 were considered.A steady commercial computational fluid dynamic solver was employed to solve the flow field and locomotive drag for each of the scenarios.The best performing wedge-shaped fairing reduced the leading locomotive drag by nominally 14%and the best performing fairing shape with the side walls reduced the drag by 17%.

Splenectomy does not affect mouse behaviors

The spleen is critical for immunity.It is the largest immune organ and immune center in the peripheral system.While the relationship between behavior and immunity has been demonstrated in physiology and diseases,the role of the spleen in behavior is not clear.To investigate the effects of the spleen on behaviors,we performed a refined splenectomy procedure on C57BL/6J mice and performed an open field test,circadian rhythm test,elevated plus maze,sucrose preference test,and Barnes maze test.Splenectomy did not induce changes in general locomotion,circadian rhythms,learning and memory,or depression/anxiety-related behaviors.To further investigate the effects of spleen on stress susceptibility,we established mouse models of depression through chronic unpredictable mild stress.The behavioral performances of mice subjected to splenectomy showed no differences from control animals.These findings suggest that splenectomy does not cause changes in baseline behavioral performance in mice.

Chx10+V2a interneurons in spinal motor regulation and spinal cord injury

Chx10-expressing V2 a(Chx10+V2 a) spinal interneurons play a large role in the excitatory drive of motoneurons. Chemogenetic ablation studies have demonstrated the essential nature of Chx10+V2 a interneurons in the regulation of locomotor initiation, maintenance, alternation, speed, and rhythmicity. The role of Chx10+V2 a interneurons in locomotion and autonomic nervous system regulation is thought to be robust, but their precise role in spinal motor regulation and spinal cord injury have not been fully explored. The present paper reviews the origin, characteristics, and functional roles of Chx10+V2 a interneurons with an emphasis on their involvement in the pathogenesis of spinal cord injury. The diverse functional properties of these cells have only been substantiated by and are due in large part to their integration in a variety of diverse spinal circuits. Chx10+V2 a interneurons play an integral role in conferring locomotion, which integrates various corticospinal, mechanosensory, and interneuron pathways. Moreover, accumulating evidence suggests that Chx10+V2 a interneurons also play an important role in rhythmic patterning maintenance, leftright alternation of central pattern generation, and locomotor pattern generation in higher order mammals, likely conferring complex locomotion. Consequently, the latest research has focused on postinjury transplantation and noninvasive stimulation of Chx10+V2 a interneurons as a therapeutic strategy, particularly in spinal cord injury. Finally, we review the latest preclinical study advances in laboratory derivation and stimulation/transplantation of these cells as a strategy for the treatment of spinal cord injury. The evidence supports that the Chx10+V2 a interneurons act as a new therapeutic target for spinal cord injury. Future optimization strategies should focus on the viability, maturity, and functional integration of Chx10+V2 a interneurons transplanted in spinal cord injury foci.

Cyclo (MQCNS) has the potential to treat ischemic stroke

We previously found that monocyte locomotion inhibitory factor has a neuroprotective effect on ischemic brain injury during the acute phase of stro ke.Therefore,we modified the structure of an anti-inflammato ry monocyte locomotion inhibitory factor peptide to construct an active cyclic peptide—Cyclo(MQCNS)(LZ-3)—and investigated its effects on ischemic stroke.In this study,we established a rat model of ischemic stroke by occluding the middle cerebral artery and then administered LZ-3(2 or 4 mg/kg) via the tail vein for 7 consecutive days.Our res ults showed that LZ-3(2 or 4 mg/kg) substantially decreased infarct volu m e,reduced co rtical ne rve cell death,improved neurological function,reduced cortical and hippocampal injury,and decreased the levels of inflammatory factors in the blood and brain tissues.In a well-diffe rentiated,oxygen-glucose deprivation/reoxygenation-induced BV2 cell model of poststroke,LZ-3(100 μM) inhibited the JAK1-STAT6 signaling pathway.LZ-3 regulated microglia/macrophage polarization from the M1 to the M2 type and inhibited microglia/macrophage phagocytosis and migration via the JAK1/STAT6 signaling pathway.To conclude,LZ-3 regulates microglial activation by inhibiting the JAK1/STAT6 sign aling pathway and improves functional recovery post-stroke.

Home Automation-Based Health Assessment Along Gesture Recognition via Inertial Sensors

Hand gesture recognition (HGR) is used in a numerous applications,including medical health-care, industrial purpose and sports detection.We have developed a real-time hand gesture recognition system using inertialsensors for the smart home application. Developing such a model facilitatesthe medical health field (elders or disabled ones). Home automation has alsobeen proven to be a tremendous benefit for the elderly and disabled. Residentsare admitted to smart homes for comfort, luxury, improved quality of life,and protection against intrusion and burglars. This paper proposes a novelsystem that uses principal component analysis, linear discrimination analysisfeature extraction, and random forest as a classifier to improveHGRaccuracy.We have achieved an accuracy of 94% over the publicly benchmarked HGRdataset. The proposed system can be used to detect hand gestures in thehealthcare industry as well as in the industrial and educational sectors.

Locomotion Paradigms of Topological Space in Shakespeare’s Double Falsehood

In the 16th and 17th century,Britain was constantly strained by sporadic plagues,famines,fires and political conflicts.As a response in literature,Shakespeare has constructed an annular locomotion paradigm in Fletcher and his collaboration work Cardenio.Be more specific,the locomotion routes can be exemplified in Möbius strip,a rhizome system,a reciprocating juxtaposition between the foreground and the background,either of which finally runs to an annular schema.The annular in narration corresponds with The Globe theater and the round world.Shakespeare may express his expectation and prospect for the uprising bourgeoise and the newly found world by the resurrection theme in literature.

Simulation study on the influence of longitudinal dynamic force on extreme-long heavy-haul trains

Purpose–The objective of this study is to investigate the impact of longitudinal forces on extreme-long heavy-haul trains,providing new insights and methods for their design and operation,thereby enhancing safety,operational efficiency and track system design.Design/methodology/approach–A longitudinal dynamics simulation model of the super long heavy haul train was established and verified by the braking test data of 30,000 t heavy-haul combination train on the long and steep down grade of Daqing Line.The simulation model was used to analyze the influence of factors on the longitudinal force of super long heavy haul train.Findings–Under normal conditions,the formation length of extreme-long heavy-haul combined train has a small effect on the maximum longitudinal coupler force under full service braking and emergency braking on the straight line.The slope difference of the long and steep down grade has a great impact on the maximum longitudinal coupler force of the extreme-long heavy-haul trains.Under the condition that the longitudinal force does not exceed the safety limit of 2,250 kN under full service braking at the speed of 60 km/h the maximum allowable slope difference of long and steep down grade for 40,000 t super long heavy-haul combined trains is 13‰,and that of 100,000 t is only 5‰.Originality/value–The results will provide important theoretical basis and practical guidance for further improving the transportation efficiency and safety of extreme-long heavy-haul trains.

Typical faults and safety analysis of brake controller for AC locomotive

Purpose–The brake controller is a key component of the locomotive brake system.It is essential to study its safety.Design/methodology/approach–This paper summarizes and analyzes typical faults of the brake controller,and proposes four categories of faults:position sensor faults,microswitch faults,mechanical faults and communication faults.Suggestions and methods for improving the safety of the brake controller are also presented.Findings–In this paper,a self-judgment and self-learning dynamic calibration method is proposed,which integrates the linear error of the sensor and the manufacturing and assembly errors of the brake controller to solve the output drift.This paper also proposes a logic for diagnosing and handling microswitch faults.Suggestions are proposed for other faults of brake controller.Originality/value–The methods proposed in this paper can greatly improve the usability of the brake controller and reduce the failure rate.

Design of a Vibration Sensor Based Train Arrival Detection System to Prevent Elephant-Train Accidents in Sri Lanka

At present,Sri Lanka is home to about 5,000-6,000 wild elephants roaming over close to 70%of the country’s land.Despite this blessing,around 150 elephants die each year due to many reasons.The main reasons for the altercations between humans and elephants are the drastic increase in the human population,human encroachment upon elephant territory for agriculture and settlements and unplanned development and transportation efforts.Elephants are long lived herbivores,and their survival depends upon regular migration over large distances to search for food,water,and social and reproductive partners.According to the Sri Lanka railways the average number of elephants that get killed due to elephant-railway accidents is about 9 per year.As a solution for this problem,we have proposed a novel system to pass a signal to indicate the train arrival.The proposed system detects the vibration of the locomotives and after detecting the vibration,alarm system will generate a high frequency signal within the frequency range,where the elephants are sensitive.The proposed system is a low cost device and this can be placed anywhere at any time.Moreover,this project aims to protect elephants from being harmed which usually happen due to various human activities.

Assessment of locomotion behavioral defects induced by acute toxicity from heavy metal exposure in nematode Caenorhabditis elegans

Locomotion behaviors are susceptible to disruption by a broad spectrum of chemicals and environmental stresses. However, no systematic testing of locomotion behavior defects induced by metal exposure has been conducted in the model organism of nematode Caenorhabditis elegans. In this study, the acute toxicity from heavy metal exposure on the locomotion behaviors was analyzed in nematodes. Endpoints of head thrash, body bend, forward turn, backward turn, and Omega/U turn were chosen to evaluate the locomotio...

Design and Optimization of Wheel-legged Robot:Rolling-Wolf

Though the studies of wheel-legged robots have achieved great success, the existing ones still have defects in load distribution, structure stability and carrying capacity. For overcoming these shortcomings, a new kind of wheel-legged robot（Rolling-Wolf） is designed. It is actuated by means of ball screws and sliders, and each leg forms two stable triangle structures at any moment, which is simple but has high structure stability. The positional posture model and statics model are built and used to analyze the kinematic and mechanical properties of Rolling-Wolf. Based on these two models, important indexes for evaluating its motion performance are analyzed. According to the models and indexes, all of the structure parameters which influence the motion performance of Rolling-Wolf are optimized by the method of Archive-based Micro Genetic Algorithm（AMGA） by using Isight and Matlab software. Compared to the initial values, the maximum rotation angle of the thigh is improved by 4.17%, the maximum lifting height of the wheel is improved by 65.53%, and the maximum driving forces of the thigh and calf are decreased by 25.5% and 12.58%, respectively. The conspicuous optimization results indicate that Rolling-Wolf is much more excellent. The novel wheel-leg structure of Rolling-Wolf is efficient in promoting the load distribution, structure stability and carrying capacity of wheel-legged robot and the proposed optimization method provides a new approach for structure optimization.

Experimentation of Fish Swimming Based on Tracking Locomotion Locus

There are many kinds of swimming mode in the fish world, and we investigated two of them, used by cyprinids and bulltrout. In this paper we track the locomotion locus by marks in different flow velocity from 0.2 m·s^-1 to 0.8 m·s^-1. By fit the data above we could find out the locomotion mechanism of the two kinds of fish and generate a mathematical model of fish kine- matics. The cyprinid fish has a greater oscillation period and amplitude compared with the bulltrout, and the bulltrout changes velocity mainly by controlling frequency of oscillation.

Effect of mesenchymal stem cells transplantation combining with hyperbaric oxygen therapy on rehabilitation of rat spinal cord injury

Objective:To investigate the effect of BMSCs transplantation plus hyperbaric oxygen(HBO)on repair of rat SCI.Methods:Seventy five male rats were divided randomly into five groups:sham,vehicle.BMSCs transplantation group,combination group,15 rats in each group.Every week after the SCI onset,all animals were evaluated for behavior outcome by Basso-BeattleBresnahan(BBB) score and inclined plane test.Axon recovery was examined with focal spinal cord tissue by electron microscope at 6 weeks after the SCI onset.HE staining and BrdU staining were performed to examine the BMSCs and lesion post injury.Somatosensory evoked potential(SEP) testing was performed to detect the recovery of neural conduction.Results from the behavior tests from combination group were significant higher than rats which received only transplantation or HBO treatment.Results from histopathology showed favorable recovery from combination group than other treatment groups.The number of BrdU+ in combination group were measureable more than transplantation group(P<0.05).The greatest decrease in TNF-α,IL-1β,IL-6.IFN-α determined by Elisa assay in combination group were evident too.Conclusions:BMSCs transplantation can promote the functional recovery of rat hind limbs after SCI,and its combination with HBO has a synergistic effect.

DEVELOPMENT AND MOTION ANALYSIS OF MINIATURE WHEEL-TRACK-LEGGED MOBILE ROBOT

A miniature wheel-track-legged mobile robot to carry out military and civilian missions in both indoor and outdoor environments is presented. Firstly, the mechanical design is discussed, which consists of four wheeled and four independently controlled tracked arms, embedded control system and teleoperation. Then the locomotion modes of the mobile robot and motion analysis are analyzed. The mobile robot can move using wheeled, tracked and legged modes, and it has the characteristics of posture-recovering, high mobility, small size and light weight. Finally, the effectiveness of the deve-loped mobile robot is confirmed by experiments such as posture recovering when tipped over, climb-ing stairs and traversing the high step.

Capsule endoscopy:the road ahead

Since its introduction into clinical practice 15 years ago,capsule endoscopy(CE)has become the first-line investigation procedure in some small bowel pathologies,and more recently,dedicated esophageal and colon CE have expanded the fields of application to include the upper and lower gastrointestinal disorders.During this time,CE has become increasingly popular among gastroenterologists,with more than 2 million capsule examinations performed worldwide,and nearly 3000Pub Med-listed studies on its different aspects published.This huge interest in CE may be explained by its noninvasive nature,patient comfort,safety,and access to anatomical regions unattainable via conventional endoscopy.However,CE has several limitations which impede its wider clinical applications,including the lack of therapeutic capabilities,inability to obtain biopsies and control its locomotion.Several research groups are currently working to overcome these limitations,while novel devices able to control capsule movement,obtain high quality images,insufflate the gut lumen,perform chromoendoscopy,biopsy of suspect lesions,or even deliver targeted drugs directly to specific sites are under development.Overlooking current limitations,especially as some of them have already been successfully surmounted,and based on the tremendous progress in technology,it is expected that,by the end of next 15years,CE able to perform both diagnostic and therapeutic procedures will remain the major form of digestive endoscopy.This review summarizes the literature that prognosticates about the future developments of CE.

Kinematics of Terrestrial Locomotion in Mole Cricket Gryllotalpa orientalis

The fore leg of mole cricket （Orthoptera： Glyllotalpidae） has developed into claw for digging and excavating. As the result of having a well-suited body and appendages for living underground, mole cricket still needs to manoeuvre on land in some cases with some kinds of gait. In this paper, the three-dimensional kinematics information of mole cricket in terrestrial walking was recorded by using a high speed 3D video recording system. The mode and the gait of the terrestrial walking mole cricket were investigated by analyzing the kinematics parameters, and the kinematics coupling disciplines of each limb and body were discussed. The results show that the locomotion gait of mole cricket in terrestrial walking belongs to a distinctive alternating tripod gait. We also found that the fore legs of a mole cricket are not as effective as that of common hexapod insects, its middle legs and body joints act more effective in walking and turning which compensate the function of fore legs. The terrestrial lo-comotion of mole cricket is the result of biological coupling of three pairs of legs, the distinctive alternating tripod gait and the trunk locomotion.

Learning from Fish: Kinematics and Experimental Hydrodynamics for Roboticists

Over the past 20 years, experimental analyses of the biomechanics of locomotion in fishes have generated a number of key findings that are relevant to the construction of biomimetic fish robots. In this paper, we present 16 results from recent experimental research on the mechanics, kinematics, fluid dynamics, and control of fish locomotion that summarize recent work on fish biomechanics. The findings and principles that have emerged from biomechanical studies of fish locomotion provide important insights into the functional design of fishes and suggest specific design features relevant to construction of robotic fish-inspired vehicles that underlie the high locomotor performance exhibited by fishes.

From cortex to cord: motor circuit plasticity after spinal cord injury

Spinal cord injury is associated with chronic sensorimotor deficits due to the interruption of ascending and descending tracts between the brain and spinal cord. Functional recovery after anatomically complete spinal cord injury is limited due to the lack of long-distance axonal regeneration of severed fibers in the adult central nervous system. Most spinal cord injuries in humans, however, are anatomically incomplete. Although restorative treatment options for spinal cord injury remain currently limited, research from experimental models of spinal cord injury have revealed a tremendous capability for both spontaneous and treatment-induced plasticity of the corticospinal system that supports functional recovery. We review recent advances in the understanding of corticospinal circuit plasticity after spinal cord injury and concentrate mainly on the hindlimb motor cortex, its corticospinal projections, and the role of spinal mechanisms that support locomotor recovery. First, we discuss plasticity that occurs at the level of motor cortex and the reorganization of cortical movement representations. Next, we explore downstream plasticity in corticospinal projections. We then review the role of spinal mechanisms in locomotor recovery. We conclude with a perspective on harnessing neuroplasticity with therapeutic interventions to promote functional recovery.