Loading Gauge Research Articles

Curving Performance Analysis of a Freight Train Transporting 50-Meter-long Rail Using Multibody Dynamics Simulation

Long rails are normally used in highspeed railways to minimize the number of rail joints and the dynamic impact force that follows. However, transporting long rails using a freight train requires multiple wagons for each rail section, presenting potential safety and loading gauge issues, especially when going through curves. Thus, a safety assessment needs to be done prior to actual transport. Computational simulation can be used for preliminary assessment. Finite element analysis can be used to incorporate the flexibility of the rails into the analysis but requires significant manpower and computer power to perform. In this study, an alternative method to model rail flexibility using a multibody approach is presented. The rails are sectioned into multiple rigid bodies along their length and interconnected using rotational joints. The stiffness coefficient of the joints is defined as a function of the actual rail’s physical properties. This modelling technique results in a simplified multibody model that retains the original rail elastic properties. Simulations of the constructed rail model hauled using a freight train were done and the results were compared to on-track test measurements of the same configuration. The comparison generally showed good agreement, showing this modelling technique’s ability and accuracy to simulate the case.

Through Running and Integration of Federal Railroad Administration and Federal Transit Administration Regulated Passenger Trains: A Path Toward Mixing Intercity, Commuter, Metro, and Light Rail on the Same Tracks

U.S. rail transit (subways, metros, and light rail) and Federal Railroad Administration (FRA) regulated heavy rail (commuter, intercity and regional rail) operate completely separately in revenue service. This necessitates transfers between the modes at terminals. While not unique to the U.S.A., its version of this practice is extreme and prevents the development of robust seamless rail networks. Especially in the post-Covid environment, this leaves commuter rail in search of a mission and rail transit isolated from suburbs. This paper discusses the statutory regulatory scheme that divides the two modes in the U.S.A. It will analyze the justification for the segregation and its history. Such issues include potential collisions, weight, crashworthiness, electrification, signaling, loading gauge, platform height, and operating practices. This paper concludes that the regulatory barrier preventing an FRA-regulated train from going onto a non-FRA railroad are surmountable. Running through trains between the FRA-regulated system and the rail transit network would enhance regional networks. The “Karlsruhe model” in Germany and the through running of regional trains onto the Tokyo subway network are two prime examples. Recent technological advances—such as dual mode battery multiple units, robust signaling systems such as Communications Based Train Control and Positive Train Control, and advanced car body designs able to deal with different loading gauges—make through running more practical. With little or no new right-of-way, it is possible to create far more useful rail networks. Potential shared networks at the conceptual level are discussed for Los Angeles, Seattle, Washington, D.C., Dallas, and Sacramento.

Mattress Coil Spring Fatigue and Weight-Bearing Support: Comparison of Weight-Bearing and Non–Weight-Bearing Springs

ObjectiveThe purpose of this study was to compare the firmness of used mattress coil springs from the areas bearing greatest body weight versus areas subjected to little compression. MethodsWeight-bearing springs (WBS) extracted from the center of the mattresses (N = 32), and non–weight-bearing springs (NWBS) extracted from the head/foot were of the same mattresses. To determine spring weakness, a 1296-g ingot was placed on the coil, and the compression distance was measured (cm). In addition, a gauge was used to measure the amount of pressure required to compress the coil springs a distance of 2 cm. Comparison between WBS and NWBS data were statistically treated using independent t tests and a 1-way analysis of variance. ResultsThere were no significant group differences in weight or height in unloaded coils. However, there were significant (P < .05) differences in coil spring compression distance under load (WBS = 2.78 ± 0.34 cm; NWBS = 1.52 ± 0.39 cm) and force gauge compression (WBS = 1090.51 ± 88.42 g; NWBS = 1213.12 ± 71.38 g) between groups. ConclusionThis study found that WBSs were weaker when compressed than the NWBS from used mattresses, and such characteristics may not be visually apparent in a mattress when not in use. Thus, coil springs in bedding systems may eventually fail to provide the initial structural support after use. Such sagging may compromise sleep posture with accompanying poor sleep quality and quantity.

Modeling the effect of gauge length on the mechanical properties of Chitin Whiskers reinforced composites

Mechanical properties (tensile strength and modulus) of Chitin Whiskers fibre-reinforced poly(acrylic acid) with different fibre loading and different gauge lengths are compared with theories of reinforcement. The addition of random oriented Chitin Whiskers to poly(acrylic acid) matrix increased in tensile strength and elastic modulus of the composite. There was a steady increase in tensile stress and Elastic modulus within the volume fraction range investigated. The properties of the composite at different gauge lengths were studied. Within the same volume fraction, the tensile stress decreases as the gauge length increases. It is the reverse for the Elastic Modulus. Irrespective of filler loading and the theoretical modelling equations the tensile stress can be predicted at 40 mm gauge length. For the Elastic Modulus, the prediction of the property varies within the gauge lengths investigated. At higher filler loading, a smaller gauge length is required to predict the Elastic modulus. The comparative study between the tensile stresses obtained by experiment and selected theoretical models showed that the Parallel and Series models of the Rule of Mixture produced more accurate prediction, followed by Halpin-Tsai and modified Halpin-Tsai models. Guth's model was the least as the percentage deviation from the experimental data was very high when predicting the Elastic modulus. The density of the nanocomposite films were 1.08g/cm3, 1.023, and 1.024g/cm3 respectively, for 3%, 6%, and 9% weight filler and were in agreement with the theoretical data.

STRENGTH TESTS OF A CORRUGATED AIRCRAFT CFRP SPAR

The results of full-scale strength tests of an aircraft spar made of carbon fiber with a corrugated wall are presented. Strength tests of the spar structure were carried out in three stages, including static and cyclic loading. During each stage of loading, acoustic emission (AE) and strain gauge control of the spar was carried out. Real-time location of AE signals characterized the most dangerous areas in the process of destruction of the root zone of the spar and was carried out using the "time window" algorithm moving along the implementation of the AE signal. To determine the time of arrival of the AE signal, two threshold levels were selected, one of which corresponded to the prehistory noise level, and the second level corresponded to the minimum signal energy level exceeding the noise level. Using tensometry, the maximum stresses were found in different zones of the spar, where the AE signals were located.

Erneuerung Kuckuckslay Tunnel – Aktuelle Erfahrungen beim Einsatz der Tunnel‐im‐Tunnel‐Methode

AbstractThe 450‐metre long Kuckuckslay Tunnel is a double track railway tunnel dating from 1871. It is located in Germany on the line between Trier and Cologne along the river Kyll. Since its commissioning, the tunnel is a non‐electrified line and has undergone only a few refurbishing measures. In 2018, a joint venture was commissioned to refurbish the Kuckuckslay Tunnel. During a 2.5‐year construction period, the Kuckuckslay Tunnel will be expanded using conventional tunnelling and provided with a new concrete lining. The so‐called ‘Tunnel‐im‐Tunnel‐Methode' would be used for the expansion, during which rail traffic could be maintained. In this case, the loading gauge of the railway in the area of the tunnelling work would be protected by a mobile construction rig. The Kuckuckslay Tunnel construction project offered a particular challenge due to the severely limited space inside and outside the tunnel, as well as the environmental conditions within a protected area. This article describes how these challenges were implemented and gives an overview of the state of work, as well as technical solutions and experience from the work completed.

A Simple Foot Plantar Pressure Measurement Platform System Using Force-Sensing Resistors

Generally, there are two types of working style, i.e., some people work in sitting conditions, and the remaining work mostly in a standing position. For people working in a standing position, they can spend hours in a day doing their work standing. These people do not realize that it can cause medical issues, especially for the feet, namely biometric problems. In addition, several doctors in Indonesia are already aware of this issue and state that the biometric problems faced by those kinds of people can be predicted from the load distribution on the foot. However, the tool used by the doctors in Indonesia to measure biometric problems is not a digital tool. Therefore it is very difficult to measure and predict the biometric problems quantitatively. This study aims to develop a low-cost static load measuring device using force-sensing resistor (FSR) sensors. The measuring instrument is designed in the form of a pressure plate platform which consist of 30 FSR 402 sensors. The sensors are placed right underneath the display area of the foot, 15 sensors on the soles of the left and right feet. Ten students from the Department of Mechanical Engineering, Diponegoro University (five men and five women) were asked to stand on the platform. Each subject also measured foot length (FL) to estimate shoe size, foot area contact (FAC) for validation between genders, and foot type using the digital footprint tools. From the results of measurements obtained for the left foot in the medial mid foot area, i.e., in sensors 5 and 7, not exposed to the load, on almost all subjects except subject number 3 with a load of 0.196 kg on sensor 7. The highest average load occurs in the heel area i.e., sensor 1 measured 0.713 kg and the smallest average load occurs in the five sensors, with 0 kg. A static load gauge that is designed to be used to measure each leg area for subjects with a shoe size of 40–42 with low price to be held in hospital-orthopedic hospitals and biomechanical research centers.

Mechanical behavior of implant assisted removable partial denture for Kennedy class II.

This study evaluated the mechanical response of a removable partial denture (RPD) in Kennedy Class II according to being associated or not with implants. Four RPDs were manufactured for a Kennedy Class II: CRPD - Conventional RPD, RPD+1M, RPD+2M and RPD+12M, respectively, signifying implant assisted RPDs with the implant installed in the first molar, second molar, and in the first and second molars. The finite element method was used to determine the most damaged support tooth under compressive load (300N, 10s) and strain gauge analysis was used to evaluate the microstrain. All groups were submitted to a retentive force analysis (0.5 mm/mm, 100kgf). Microstrain and retentive force data were submitted to One-way ANOVA and the Tukey test, all with α=5%. High microstrain was observed in the second premolar adjacent to the edentulous space under compression load (p< 0.01). RPD+12M presented lower microstrain, however being similar to RPD+2M. RPD+1M presented a higher mean value of retentive force, but similar to RPD+12M. FEM showed RPD assisted by implants concentrates less stress in the periodontal ligament. The association of two implants was sufficient to decrease the stress generated in the implants. The most stressed region for the o-ring abutment was the threads, and the group with two implants showed the lowest stress concentration. In cases of Kennedy Class II, the association of RPD with implants in the molar region is a favorable option for patient rehabilitation, reducing the movement of the direct retainer adjacent to the edentulous space, increasing the removal force and decreasing the stress magnitude in the periodontal ligament. Key words:Removable partial denture, Finite element analysis, Prosthetic dentistry, Implant-assisted RPD, Distal extension RPD considerations.

Mechanical behavior of implant assisted removable partial denture for Kennedy class II

BackgroundThis study evaluated the mechanical response of a removable partial denture (RPD) in Kennedy Class II according to being associated or not with implants. Material and MethodsFour RPDs were manufactured for a Kennedy Class II: CRPD - Conventional RPD, RPD+1M, RPD+2M and RPD+12M, respectively, signifying implant assisted RPDs with the implant installed in the first molar, second molar, and in the first and second molars. The finite element method was used to determine the most damaged support tooth under compressive load (300N, 10s) and strain gauge analysis was used to evaluate the microstrain. All groups were submitted to a retentive force analysis (0.5 mm/mm, 100kgf). Microstrain and retentive force data were submitted to One-way ANOVA and the Tukey test, all with α=5%. ResultsHigh microstrain was observed in the second premolar adjacent to the edentulous space under compression load (p< 0.01). RPD+12M presented lower microstrain, however being similar to RPD+2M. RPD+1M presented a higher mean value of retentive force, but similar to RPD+12M. FEM showed RPD assisted by implants concentrates less stress in the periodontal ligament. The association of two implants was sufficient to decrease the stress generated in the implants. The most stressed region for the o-ring abutment was the threads, and the group with two implants showed the lowest stress concentration. ConclusionsIn cases of Kennedy Class II, the association of RPD with implants in the molar region is a favorable option for patient rehabilitation, reducing the movement of the direct retainer adjacent to the edentulous space, increasing the removal force and decreasing the stress magnitude in the periodontal ligament. Key words:Removable partial denture, Finite element analysis, Prosthetic dentistry, Implant-assisted RPD, Distal extension RPD considerations.

ASSESSMENT TO THE PILE BEARING CAPACITY OF INJECTION PILE BASED ON PILE DRIVING ANALYZER AND RE-INJECTION TEST RESULTS (CASE: EASTKAL PENAJAM PROJECT)

Injection piling method was used as the main pile driving method at the three warehouses in the Eastkal Penajam project, Kalimantan, Indonesia. The sub-soil compositions are dominated by clay and sandy soil with very soft to medium consistencies. By using injection pile equipment, it is possible to measure the pile bearing capacity from the loading gauge. Since the soil is dominated by clay, the friction capacity overtime will be improved. For that purpose, the piles were re-injected again after 3, 10, 11, and 25 days. To establish the forecasting expression of pile bearing capacity enhancement for other piles, non-linear regression analysis was performed. To verify the result, pile driving analyzer (PDA) test for selected piles was carried out. The results from PDA test were further analyzed by using both direct fields reading in the PDA data logger and the Case Pile Wave Analysis Program (CAPWAP). A linear regression analysis was carried out to complete the blank data due to the field measurement limitation. In addition to the obtained field data, theoretical analysis of pile bearing capacity with Luciano Decourt method is carried out. From the comparisons of all data, it can be concluded that re-injection pile method provides the highest safety factor followed by PDA test, CAPWAP analysis, and theoretical design calculation with Luciano Decourt method.

Automatic Generation of Diagrammatic Subway Maps for Any Date with Maple

The second author was one of the authors of a computer package written in Maple that could automatically generate railway maps of a network for any date. This package was presented at ACA’2008 and its design and implementation is described in a previous article. Each section of the network was colored accordingly to its characteristics. The position of the nodes (stations, junctions, $$\ldots $$) was obtained from a list of geographical coordinates. The work presented here deals with a similar although not identical case: now subway networks are treated as graphs with the help of a computer algebra system in order to obtain the diagrammatic map for any date. Most subway network maps follow more or less closely the ideas introduced by Harry Beck in his diagrammatic design of London subway map (the distances between stations and geographic orientation of the lines don’t have to be respected, as the clarity and the number of stations between two stations is the key information to be visualized). Therefore allocating nodes is far simpler, and we have decided to manually allocate the stations on a predefined grid and to automatize the drawing of the network. The situation is also simpler because all lines are double track and electrified. For instance in Madrid subway there are minor differences between lines, such as the kind of catenary (classic or rigid), the loading gauge (narrow/broad), $$\ldots $$ that will not be considered here. Each node and edge of the graph has dates associated: inauguration date/closure date–the latter if applies. The package takes advantage of the simplifications w.r.t. the previous article mentioned above and the features of Maple’sGraphTheory package. This way the approach, although general, can be implemented in relatively few lines of code. We know of no other similar works. The work is illustrated with the case of Madrid subway network, one of the biggest ones in the world.

Successful Balanced Gait after Reconstruction of the Weight-bearing Mid Plantar Region Using a Free Contralateral Medial Plantar Flap

Summary:Although soft tissue sarcoma, especially in the sole of the foot, is a rare disease, weight-bearing region reconstruction considering postoperative gait is needed. For functionally satisfactory sole reconstruction, it is important to cover the weight-bearing region with a nonbulky but durable skin paddle that can withstand a significant amount of shear pressure. We herein present a case in which a free contralateral medial plantar flap was used for reconstruction of the weight-bearing mid plantar region for a 41-year-old man who suffered from mid-foot sarcoma. Gait analysis was performed 6 months after the operation with the lower limb loading gauge sheet, and the result indicated that postoperative balanced gait was obtained. The free medial plantar flap transfer after sole sarcoma resection has several advantages. First, the characteristic of this flap with solid anchoring to deep tissue to resist shearing makes it possible to lower the chances of postoperative ulceration. Second, the medial plantar flap has optimal thickness and good color and texture match for sole reconstruction. Third, a sensate flap can be achieved if the medial plantar nerve is included. Although further clinical investigations such as long-term follow-up will be required to confirm its efficacy, this method would be one option for treating sole sarcoma.

Results of comprehensive studies conducted by the Central Research Institute (VNIIZhT) and construction work of the Ministry of Railways (RZD) to increase the loading gauge of freight and passenger rolling stock on the railways of Russian Federation

The article presents the content and results of a set of studies on the scientific and methodological support for the modernization of structures and devices built according to the old loading gauge standards or its expired durability, the entire 1520 (1524) mm gauge railway network under the loading gauge standard T for rolling stock, allowing to increase axle and running loads of cars and due to this — the mass of trains, as well as solve the global problem that arose in the middle of the last century to increase the efficiency of the most important branch of Russia — railway transport. Variants of increased loading gauges were developed (Тпр for any rolling stock, Тц for tanks, Та — for electric rolling stock, Тб — for passenger cars), which were included in the GOST 9238 – 83 “Loading gauges of railway rolling stock and structure clearance” and Ministry of railways instructions (no. TsP/4425 — for clearance of structures; no. TsV/4422 — for loading gauge of the rolling stock and no. TsD/4172 — for transportation of oversized and heavy (nonstandard) freights), as well as zonal and flatcars loading gauges. Scientific and methodological studies carried out by the institute during the half-century period (mid-XX — early XXI) identified structures and devices that limit the use of rolling stock of loading standard T, its elimination during 1982 – 2005, as well as transition of industrial enterprises to the production of new freight and passenger cars of increased loading standards Тпр and Та, developed by the Institute. This identification was made on the basis of the overall classification of all railway infrastructure and access railroads of the former USSR. New regulatory framework for railway rolling stock loading gauges and structure clearance (GOST 9238 – 2013) was developed based on a global survey of actual dimensions of all structures and infrastructure devices of the 1520 (1524) mm gauge railways (area 1520). Railway Research Institute of the Ministry of Railway Transport (currently, JSC “VNIIZhT”) made scientific and methodological support for the modernization of infrastructure objects, exhausted its life span for the 100-year period of operation. Scientific and methodological support carried out by the Institute allowed the creation and operation of rolling stock with an increased loading gauge standard Тпр: for freight traffic — with increased running loads by 2 ton/m or more compared to European railways; for passenger traffic — more comfortable and 39 % more spacious double-deck compartment cars. Increasing the loading gauge of the rolling stock provides increased efficiency of rail transport by increasing productivity, reducing the required fleet of cars for the transportation of equal volumes as well as operating costs. At the same time achieved annual total economic effect amounts to 2,205 billion rubles. Introduction of the flatcar loading gauge contributes to the organization of transportation of heavy trucks by rail and, therefore, improve the environmental situation.

Incentives to freight railway undertakings compensating for infrastructural gaps: Methodology and practical application to Italy

The paper illustrates an incentive scheme to freight railway undertakings, proportional to the infrastructural gaps they experience on the rail network with respect to optimal performances in terms of loading gauge, length and weight. The proposed incentive is equitable and provided on an origin-destination pair basis, as opposed to the watering-can principle underlying current incentives schemes. In practice, it can be simply dispensed as a discount of the access charge the railway undertakings should pay to the rail network infrastructure manager. It also differs by type of train, to account for their different infrastructural needs, and can be adjusted on a yearly basis to account for ongoing network improvements. The main methodological challenge lies in the quantification of the infrastructural gap, defined as the difference of the unit transport costs in the current and in the optimal scenario, as a consequence of the non-additivity of concerned costs. For this aim, a specific procedure is illustrated and applied to the railway intermodal transport in Italy, to show the feasibility of the approach and highlight the differences with respect to the current incentive schemes.

Modelling assessment of farmers workload

The article presents the principles of modeling the physical load assessment of farmers using Bayesian Network technology. Despite rapid development of mechanization and automation of work processes in agriculture, many farmers use their own physical strength, such as manual handling of loads. There are periods in which a farmer performs several or even a dozen of variety activities during the 24 hours. It often happens that all these activities do in a hurry, without rest, working after several hours a day, which further strengthens his physical load. The variety of activities often causes problems with the use indicators to assess the physical load gauges, so Bayesian Network technology was used to develop the evaluation model.

Контрейлерный габарит погрузки, проблемы и процесс внедрения

Analysis of freight traffic development abroad has revealed the trend of intensive growth of the freight transport centers to create optimal logistic links for the purpose of the interaction between different modes of transport and further development of piggyback transport. The article thoroughly describes two stages of the preparatory work for the organization of piggyback transport on the network of the Russian railways. The first stage outlined the need for piggyback loading gauge. Piggyback loading gauge - is the minimal transverse (perpendicular to track axis) outline in which, considering the mounting, the load (road vehicle) should be placed on a specialized platform as part of piggyback train. Such loading gauge was developed in 2012.Measures to prepare the routes for running regular piggyback trains were discussed in the second stage. Introduction of piggyback loading gauge and training routes linked to the development of normative-methodical documentation. The results of both analytical and experimental development become the basis of this document. In order to evaluate the main possibility of input piggyback trains on routes covering the entire network of railways of the Russian Federation, global analysis of the actual dimensions of infrastructure clearance was made to determine whether they meet minimum structural clearance to that required for the safe handling of piggyback trains. Studies confirm the fundamental possibility of the piggyback transport almost on the entire network of the Russian railways.

How to make modal shift from road to rail possible in the European transport market, as aspired to in the EU Transport White Paper 2011

The total demand for freight transport in Europe has increased significantly in recent decades, but most of it has been handled by road transport. To fulfil the modal shift targets set in the EU White Paper 2011, it will be necessary to double rail’s market share from today’s 18 %, by 2050. Translating this into reality means rail will have to handle 3 to 4 times the cargo volume it does today. With this in mind, the paper develops a vision of an efficient rail freight system in 2050. To achieve the above objective, the research applies literature survey and group discussion methodology and applying a system approach. Keeping on board the EU Transport White Paper 2011 modal shift targets, as well as future freight demand and customer requirements, the current research attempts to answer the following three critical questions: The authors find that the service quality can be improved by better planning, application of appropriate ICT-systems and adoption of an integrated supply chain approach. A more customer-orientated service can also be achieved by further deregulation of rail. There is also an urgent need for a faster implementation of Rail Freight Corridors (RFC). As well as liner trains, future rail freight services should be offering end-point trains, with semi/ fully automated loading/unloading equipment in hub-terminals, as well as terminals at sidings to improve the availability of intermodal operation. To offer a competitive price and reliable service, a reduction in operating costs will be vital by implementing a number of measures, including operation of heavier and longer trains, wider loading gauge, higher average speed, and better utilisation of wagon space and all assets. This will bring increased capacity, as well as better timetable planning, signalling systems and infrastructure improvements.

Efficient Dynamic Replication Algorithm Using Agent for Data Grid

In data grids scientific and business applications produce huge volume of data which needs to be transferred among the distributed and heterogeneous nodes of data grids. Data replication provides a solution for managing data files efficiently in large grids. The data replication helps in enhancing the data availability which reduces the overall access time of the file. In this paper an algorithm, namely, EDRA using agents for data grid, has been proposed and implemented. EDRA consists of dynamic replication of hierarchical structure taken into account for the selection of best replica. Decision for selecting the best replica is based on scheduling parameters. The scheduling parameters are bandwidth, load gauge, and computing capacity of the node. The scheduling in data grid helps in reducing the data access time. The distribution of the load on the nodes of data grid is done evenly by considering scheduling parameters. EDRA is implemented using data grid simulator, namely, OptorSim. European Data Grid CMS test bed topology is used in this experiment. The simulation results are obtained by comparing BHR, LRU, No Replication, and EDRA. The result shows the efficiency of EDRA algorithm in terms of mean job execution time, network usage, and storage usage of node.

Use of a Powered Coverlet for Moisture Removal, Skin Temperature Reduction, Odor, and Bacteria Control

The purpose of this study was to assess the ability of a powered coverlet (PCL) to control moisture, reduce skin temperature, and help control odor and microbial growth at the skin/support-surface interface. A human torso was simulated using a water temperature-regulated loading gauge. The PCL is a 3-tier coverlet composed of vapor-permeable, liquid-impermeable layers with a foam spacer inbetween and a fan blower to draw moisture and heat away from the patient's skin through the spacer. A fabric moisture reservoir simulated sweating skin. It was placed between the simulated human torso and pressure redistribution support surface. A change in moisture reservoir weight was used to calculate moisture vapor transfer rate; temperature and relative humidity at the support surface interface were recorded as a function of time. To test for odor control, a malodorous compound was applied daily to the coverlet with and without power for 30 days in a laboratory setting. In a separate test, both a PCL and a standard hospital sheet were inoculated with Staphylococcus aureus and incubated at 32°C to observe the PCL's ability to mitigate microbial growth. Results indicated a higher moisture vapor transfer rate with the PCL as compared to a standard hospital bed sheet (129.5 g/m/h vs 34.1 g/m/h, P < .005). The PCL also had a larger reduction in skin temperature (1.1ºC vs 0.7ºC, P = .13) when compared to control. Gas chromatography analysis showed that the PCL helped control odor better than a non-PCL (P < .05). At 24 hours, the PCL showed greater than 2 log difference of S aureus over the standard hospital sheet (P < .05). These studies indicate the potential ability of the PCL to remove moisture at the patient/support-surface interface, thus creating a microenvironment with improved moisture management and reduction in odor and microbial growth.

New solutions in designing mechanized hump yards

For the reduction of investments in the construction and operational costs, associated with the breaking-up and making-up of trains on the mechanized hump yards, the new approach to the design of the plan of yard necks of classification yards was proposed. Transfer of the park brake position to the straight segments within the curved beyond the last railroad switches allows to reduce the length of the calculated path of rolling of cuts and consequently to reduce the cost of the humping track and braking of cuts. Thus, the required brake power of retarders of the drain part of the hump yard and the park brake position is reduced. New design solutions on the placement of retarders of park brake position on tracks with minimal inter-track space were developed, namely the allocation of retarders of one bunch in the general cut-off trench with the arrangement of steps in each inter-track space on both sides of the trench; the displacement of the control equipment of retarder on the inter-track space axis for compliance with the loading gauge and structure gauge, and the corresponding displacement of the high-pressure air pipelines for the switching-on of retarders