bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparison of Gray Matter Density in Restless Legs Syndrome Patients and Matched Controls Using Voxel‐Based Morphometry
Authors: Comley Robert A. , Cervenka Simon , Palhagen Sven E. , Panagiotidis Georgios , Matthews Julian C. , Lai Robert Y. , Halldin Christer , Farde Lars , Nichols Thomas E. , Whitcher Brandon J.
Published: November 2010

BACKGROUND

Restless legs syndrome (RLS) is a common neurological disorder the pathophysiology of which is incompletely understood. Four studies have examined structural differences between the brains of RLS patients and healthy controls, using voxel‐based morphometry (VBM). All 4 studies have provided different results.

METHODS

Optimized VBM was used to search for structural differences in gray matter density. Sixteen RLS patients naïve to dopaminergic drugs and 16 age‐ and sex‐matched controls received structural T1‐weighted MR scans. Structural data were analyzed using FSL‐VBM.

RESULTS

No difference in gray matter density was detected between the two groups (voxel‐wise significance: no significant voxels at P= .89 (whole brain Family Wise Error (FWE) corrected); no significant voxels at P < .05 (whole brain False Discovery Rate (FDR) corrected; smallest achievable FDR threshold .99).

CONCLUSION/DISCUSSION

The present study did not replicate (confirm) previous findings of structural brain changes in RLS, but instead supported the findings of a recent study showing a lack of gray matter alteration in an elderly RLS population. More specifically, the results do not support neuronal loss as an underlying disease mechanism in RLS. Potential limitations in the application of VBM are also discussed.
Effects of casein phosphopeptide amorphous calcium fluoride phosphate paste on white spot lesions and dental plaque after orthodontic treatment: a 3‐month follow‐up
Authors: Beerens M. W. , Van Der Veen M. H. , Van Beek H. , Ten Cate J. M.
Published: November 2010

Beerens MW, van der Veen MH, van Beek H, ten Cate JM. Effects of casein phosphopeptide amorphous calcium fluoride phosphate paste on white spot lesions and dental plaque after orthodontic treatment: a 3‐month follow‐up. Eur J Oral Sci 2010; 118: 610–617. © 2010 Eur J Oral Sci

The effects of casein phosphopeptide amorphous calcium fluoride phosphate (CPP‐ACFP) paste vs. control paste on the remineralization of white spot caries lesions and on plaque composition were tested in a double‐blind prospective randomized clinical trial. Fifty‐four orthodontic patients, with multiple white spot lesions observed upon the removal of fixed appliances, were followed up for 3 months. Subjects were included and randomly assigned to either CPP‐ACFP paste or control paste, for use supplementary to their normal oral hygiene. Caries regression was assessed on quantitative light‐induced fluorescence (QLF) images captured directly after debonding and 6 and 12 wk thereafter. The total counts and proportions of aciduric bacteria, Streptococcus mutans, and Lactobacillus spp. were measured in plaque samples obtained just before debonding, and 6 and 12 wk afterwards. A significant decrease in fluorescence loss was found with respect to baseline for both groups and no difference was found between groups. The size of the lesion area did not change significantly over time or between the groups. The percentages of aciduric bacteria and of S. mutans decreased from 47.4 to 38.1% and from 9.6 to 6.6%, respectively. No differences were found between groups. We observed no clinical advantage for use of the CPP‐ACFP paste supplementary to normal oral hygiene over the time span of 12 wk.
Computational Characterization of Reaction Intermediates in the Photocycle of the Sensory Domain of the AppA Blue Light Photoreceptor†
Authors: Khrenova Maria G. , Domratcheva Tatiana , Schlichting Ilme , Grigorenko Bella L. , Nemukhin Alexander V.
Published: November 2010

The AppA protein with the BLUF (blue light using flavin adenine dinucleotide) domain is a blue light photoreceptor that cycle between dark‐adapted and light‐induced functional states. We characterized possible reaction intermediates in the photocycle of AppA BLUF. Molecular dynamics (MD), quantum chemical and quantum mechanical–molecular mechanical (QM/MM) calculations were carried out to describe several stable structures of a molecular system modeling the protein. The coordinates of heavy atoms from the crystal structure (PDB code 2IYG) of the protein in the dark state served as starting point for 10 ns MD simulations. Representative MD frames were used in QM(B3LYP/cc‐pVDZ)/MM(AMBER) calculations to locate minimum energy configurations of the model system. Vertical electronic excitation energies were estimated for the molecular clusters comprising the quantum subsystems of the QM/MM optimized structures using the SOS‐CIS(D) quantum chemistry method. Computational results support the occurrence of photoreaction intermediates that are characterized by spectral absorption bands between those of the dark and light states. They agree with crystal structures of reaction intermediates (PDB code 2IYI) observed in the AppA BLUF domain. Transformations of the Gln63 side chain stimulated by photo‐excitation and performed with the assistance of the chromophore and the Met106 side chain are responsible for these intermediates.
Russia's oil and gas policy
Authors: Bahgat Gawdat
Published: November 2010

Russia is a major oil and natural gas producer and exporter. In the last two decades the nation's energy policy has gone through fundamental changes. This study examines Russia's oil and natural gas sectors and Moscow's energy policy with Europe and the Organization of the Petroleum Exporting Countries. An examination of the nation's energy strategy is provided. The analysis suggests that Russia is likely to maintain its status as a major energy player; however, there are serious limitations on its potential.
Energy-Based Model Reduction Methodology for Automated Modeling
Authors: Louca Loucas S. , Stein Jeffrey L. , Hulbert Gregory M.
Published: November 2010

In recent years, algorithms have been developed to help automate the production of dynamic system models. Part of this effort has been the development of algorithms that use modeling metrics for generating minimum complexity models with realization preserving structure and parameters. Existing algorithms, add or remove ideal compliant elements from a model, and consequently do not equally emphasize the contribution of the other fundamental physical phenomena, i.e., ideal inertial or resistive elements, to the overall system behavior. Furthermore, these algorithms have only been developed for linear or linearized models, leaving the automated production of models of nonlinear systems unresolved. Other model reduction techniques suffer from similar limitations due to linearity or the requirement that the reduced models be realization preserving. This paper presents a new modeling metric, activity, which is based on energy. This metric is used to order the importance of all energy elements in a system model. The ranking of the energy elements provides the relative importance of the model parameters and this information is used as a basis to reduce the size of the model and as a type of parameter sensitivity information for system design. The metric is implemented in an automated modeling algorithm called model order reduction algorithm (MORA) that can automatically generate a hierarchical series of reduced models that are realization preserving based on choosing the energy threshold below which energy elements are not included in the model. Finally, MORA is applied to a nonlinear quarter car model to illustrate that energy elements with low activity can be eliminated from the model resulting in a reduced order model, with physically meaningful parameters, which also accurately predicts the behavior of the full model. The activity metric appears to be a valuable metric for automating the reduction of nonlinear system models—providing in the process models that provide better insight and may be more numerically efficient.
Rolling Bearings in High Speed Passenger Traffic
Authors: Kilian Matthias R.
Published: November 2010

Passenger transport today runs significantly faster than some decades ago and often operates on separate tracks especially constructed for high speed trains. As rolling bearings are very important components in the bogies of trains they have to be suitably designed for high speed. The maximum train speeds reach up to 380 km/h (236 mph) for the latest high speed applications which are 80% higher than in the earlier days of high speed traffic. The paper presents a couple of application examples of modern high speed traffic together with some typical bearing arrangements and housings. It gives some insight into measures taken in the bearing industry to meet the requirements of contemporary high speed traffic and it mentions important standards and regulations applicable for, but not restricted to European applications. The main focus is on journal bearings. Information on traction motor bearings, transmission bearings and housings is included but described in less detail.
Update on Alternative Occupant Volume Testing
Authors: Carolan Michael , Muhlanger Michelle Priante
Published: November 2010

This paper describes the conduct of the first of a series of quasi-static compression tests of rail passenger equipment being done to examine occupant volume strength. Specifically, this program is investigating methods of evaluating occupant volume integrity when loads are placed along the collision load path of the occupant volume. Budd Pioneer car 244 has been chosen as the test article to examine alternative occupant volume loading strategies. Since this car has been involved in several impact tests as part of a previous research program, it is important to verify the structural integrity of the vehicle before conducting an alternative loading test. Although the vehicle has been modified with crash energy management crush zones at both ends, the occupant volume between the body bolsters is unmodified from the original structure. The 800,000-pound compressive strength test will be used to ensure the structural integrity of the car is intact. Before the conduct of this test, repairs were made to the crush zone. These repairs included replacement of trigger elements in the form of shear bolts and shear rivets. Additionally, energy absorbing elements were removed from the pushback coupler and primary energy absorbers because they would not contribute to the load path of this test. Steel blocks were added to the sliding sill element, enabling it to contact the fixed sill and enhancing the load-bearing capacity of the sliding-fixed sill connection. Preliminary results of this test include an overall description of the test procedures, discussion of permanent deformation observed during the test, and presentation of finite-element simulation results. Detailed analysis of test results, including strain gage data, is ongoing. The test results are being compared with the finite-element model results in support of the next tests planned for this series. The next two tests will evaluate the carbody when it is loaded along its collision load path to establish the elastic limit and crippling strength.
Vertical Split Rim Failure Analysis in Railroad Wheels
Authors: Sura Venkata S. , Mahadevan Sankaran
Published: November 2010

Vertical split rim cracking, rapid unstable propagation of a sub-surface crack parallel to the front rim face, is one of the dominant railroad wheel failure types observed in North America. Wheel impact load is believed to be a trigger for this unstable crack growth. This rapid crack growth rate depends on several factors, such as wheel geometry (wheel diameter and rim thickness), load magnitude, load location, residual stresses in the rim, worn tread profile, and material defects in the rim (size, shape, location, and orientation). This paper investigates the effect of these parameters on vertical split rim cracking, using finite element analysis and fracture mechanics. Vertical split rim cracking is modeled using a three-dimensional, multiresolution, elastic-plastic finite element analysis. Material defects are modeled as mathematically sharp cracks. Wheel impacts are simulated by applying a high axle load on the tread surface. The residual stress and wheel wear effects are also included in modeling vertical split rim cracking.
Durability Research for High-Performance Concrete Box Girder of High Speed Railway
Authors: Lei Jun-Qing , Zhong Xin-Hua , Wang Wu-Qin
Published: November 2010

Now the highspeed railway development is rapid in China. In view of the quality and the features of production technology of railway pre-concrete prefabricated box girder, the experiment researches five kinds of Pumping Concrete, which are composed of different significant slurry. Through researching the Mechanical, conductive, shrinkage and creep properties of specimen, it comes to a conclusion that the main compounding principle of low shrinkage, creep and high-performance concrete of railway box girder is adopting low water and right amount of mineral admixture.
Rehabilitation of Railroad Bridges Using GFRP Composites
Authors: Hota GangaRao V. S. , Vijay P. V. , Abhari Reza S.
Published: November 2010

The use of glass fiber reinforced polymer (GFRP) composite materials to rehabilitate timber Railroad Bridge is investigated in this research. Two different rehabilitation methods were developed and implemented to strengthen timber stringers using GFRP. These methods are referred to as GFRP spray lay-up and vacuum bagging of GFRP wraps around timber members. Tests were conducted on four full scale (8″×16″×12″) timber stringers in the WVU-CFC laboratory under four point bending loads. These creosote treated timber stringers were loaded up to 20% of their ultimate loads to verify their properties. The stringers were then repaired using the above two rehabilitation methods and retested to failure. Strengthening the stringers with GFRP composites increased the shear moduli of the two stringers by 41% and 267%. Rehabilitation and load testing were carried out on an open-deck-timber railroad bridge built during early 1900’s on the South Branch Valley Railroad (SBVR) owned by the WVDOT in Moorefield, WV. Specifically, field rehabilitation involved repairing piles using GFRP composite wraps and phenolic formaldehyde adhesives. Using a 80-ton locomotive, static and dynamic tests were performed to determine the dynamic response of the substructure. Rehabilitated SBVR Bridge showed a 43% and 46% strain reduction in the piles and pile cap, respectively.
Beyond Adaptive Braking
Authors: Thurston D. F.
Published: November 2010

Train control systems use a Safe Braking Distance (SBD) to determine the appropriate length to separate trains to avoid collisions. The same properties that allow trains to propel themselves with great efficiency also prevent them from stopping suddenly. Once the SBD is determined, it can be applied to the signal system design by creating “signal blocks” that are used to determine the location of signal equipment along the track. In its simplest form, each signal block provides sufficient distance to stop the train traveling at the maximum authorized speed. More advanced train control systems utilize other means of train detection such as global positioning satellites, or track mounted transponders. Regardless of the train control technology used, the methods of determining SBD remain the same. Positive Train Control (PTC) type systems are being developed for deployment throughout the United States and are required on all passenger lines, including High Speed Rail. However all of these methodologies are based on traditional worst case scenarios. With PTC required to be deployed before the 2015 time limit, freight carriers are working on new braking algorithms that involve specific inputs such as speed, train weight and alignment. This is called “Adaptive Braking” in that it calculates a different solution based on the data on hand [22]. Reports on this development detail purely reactive methodology. Reactive methods simply imply that conditions for the calculation are based on information that is in or before real time. It is proposed to utilize a proactive approach in determining SBD to monitor adhesion conditions in advance of the train to optimize SBD and capacity.
Development of High Performance Steels for Rail Applications
Authors: Ordonez R. , Garcia C. Isaac , Kalay Semih , DeArdo Anthony J.
Published: November 2010

Higher requirements of efficiency on railroad systems have set off (among other measures) higher axle load on rails. The increase in axle loads can contribute to a series of defects on perhaps the most unappreciated component of a railroad system. Higher axle loads can lead to excessive wear, fatigue and ultimately fracture of the steel rails. Therefore to answer the challenge demanded by the increase in axle loads the development of high performance steels for rail applications is of primary importance. A research program to study the microstructural aspects of near-eutectoid steels with improved mechanical properties and wear resistance was recently completed. The new high performance rail steels were developed through a combination of advanced alloy design-thermomechanical processing-and-controlled cooling. The mechanical properties exhibited by the new steels have exceeded the AREMA requirements for this type of rail steel application. The wear resistance of the newly developed steels was evaluated and the results obtained compared to commercial rails were superior under the testing conditions used in this study. The alloy design philosophy, thermomechanical processing and properties of the new steels will be presented and discussed in this paper.
Research on Longitudinal Force Computation Theory and Experiment of the Welded Turnout on the Bridge
Authors: Yang Rong-shan , Liu Xue-yi , Wang Ping
Published: November 2010

According to characteristics of force and displacement of welded turnout on bridge, the turnout-bridge-platform integration computation model was established; the model was solved by finite element method. Taking the Meichi No.1bridge on Zhejiang-Jiangxi railway line as the example, the force and the displacement characteristics of the welded turnout on bridge were analyzed. The temperature force and the displacement of welded turnout on bridge was measured, the site test proves that the calculated results are consistent with the measurements. The analysis and the test prove that the turnout -bridge-platform integration computation model to solve the longitudinal force and displacement of welded turnout on bridge was feasible; the forces and displacements of welded turnout on bridge and CWR on bridge were different, Some parameters Influencing the longitudinal force and displacement of the welded turnout on bridge should be calculated, such as the temperature of rail, the disposal of turnout, the location of turnout and bridge, and so on; in dense turnout area, such as throat zone, the interaction between turnouts was considerable, for the sake of calculating the force and displacement of turnout on the bridge well, the integration computation model including all the turnouts and bridges should be established.
Key Construction Technology of Track Slab in Turnout Zones on Passenger Dedicated Lines
Authors: Zeng Yong , Liu Xueyi , Yang Rongshan
Published: November 2010

Diverse types of ballastless track have been developed in turnout zones, of which the prefabricated slab track in turnout zones is characterized with simple and fast construction technology and thus can preferably achieve the structure requirements. Slab tracks can be put into use after the track components are installed completely. A high demand is raised to ensure the accuracy of construction because of the complicated structure and force bearing status. This paper mainly shows the structure features, construction technology process and construction methods. Meanwhile, the construction control standards and important matters needed attention are involved too. The prefabricated slab track system in turnout zones is mainly made of turnout components, prefabricated turnout slab, concrete base and so on, which has advantages of lower structural height, stable track geometry status and less maintenance. The transition from turnout zones to section of ballastless track lines can be achieved easily without extra components. Moreover, the turnout slabs are prefabricated indoor so that the structure strength and durability can be guaranteed. At the same time by using the prefabricated slabs, the installation accuracy is improved and the amount of concrete made in site is greatly reduced. The construction of slab track turnouts mainly include construction of frost retarding layer, leveling blanket and supporting layer, rough track laying, accurate adjustment of turnout slabs, and installation of turnouts. More attention should be paid to the construction accuracy and the ability of keeping track geometry in order to achieve the high transition regularity.
A Novel Algorithm for Predicting Track Irregularities of Unit Track Sections
Authors: Liu R. K. , Xu P. , Sun Q. X.
Published: November 2010

During train runs, the interaction between train wheels and the rail track underneath makes track geometry change, which in turn results in all kinds of track irregularities. After the 6th train speed raise of China in 2007, railway transportation has shown three main new features: speed-raised, heavy-loading and high-density. Under these features, changes in railway track irregularities of China have also presented some new characteristics: higher deterioration rates of track irregularities and more frequent occurrences of track exceptions. To ensure the train operational safety and increase the transportation service quality, the preventive inspection and maintenance of railway track facilities have been put forward once again by railway maintenance departments of China. A precondition for the preventive inspection and maintenance is about how to accurately evaluate and predict the future track condition according to the historical track inspection data. In this paper, based on the characteristics of track irregularity changes and in accordance with the calculus thinking, we have developed a short-range prediction model called SRPM. The model uses track waveform data generated by the track geometry car (TGC) to predict track irregularities of a unit track section with the length of 100m for each day in a future short period of time. An algorithm for using SRPM to predict track irregularities has also been designed. According to the designed algorithm, using ORACLE database and computer program languages, we have programmed a computer software named P-SRPM. We then used P-SRPM to deal with 25 sets of TGC-generated track waveform data from the up going track of the Beijing-Shanghai railway (Jing-Hu railway) administrated by Jinan Railway Bureau (JRB) and predicted track irregularities of unit sections in the railway track segment. Finally, errors in these predictions were analyzed in both temporal and spatial dimensions. From the error analysis results, we come to the conclusion that SRPM can fairly accurately make short-range predictions for track irregularities of each unit section in the JRB-administrated Jing-Hu railway track (up going).
A Study of Compressive Stress and Compression of Hard Foam Board for Longitudinally Coupled Slab Track on Bridges
Authors: Xiang Rui , Ren Juanjuan , Zeng Yong
Published: November 2010

Longitudinally Coupled Prefabricated Ballastless Track (LCPBT) system was firstly applied on Suining-Chongqing experimental railway line and Beijing-Tianjin intercity railway line. LCPBT track structure is longitudinally continuous, with fixing a 5-cm-thick hard foam board above every bridge structure joints, between bridge protection layer and the continuous concrete base to reduce detrimental fastening pulling force in case of great rotation angle or displacement. Hard foam board ensures a steady deformation transition, and we calculate its compressive stress, compression and cubical elasticity coefficient Q, for fulfilling force-bearing and deformation requirements. Taking a two-span, simple supported beam, each with 32-m-long bridge for instance, an integral finite element model of continuous welded rail -coupled track slab -coupled concrete base –bridge beam was established, in which a vertical compression amount under 9 different load cases. The maximum bottom tensile stress of concrete base, maximum compressive stress and compression amount of hard foam board are gained from computation results. Besides, Q-value and the control value of rotation angle at bridge structure joints are suggested in this paper. The key findings are: a) under simultaneous actions of train load and beam rotation angle, the maximum bottom tensile stress of concrete base does not exceed its threshold as 250 kPa, given a Q-value of 0.5 N/mm3; b) considering the uniformity of track stiffness and track regularity, a greater Q-value is preferable and we recommend the Q-value as 0.5 N/mm3; c) the beam rotation angle at bridge structure joints should be less than 1.4, including the load cause of uneven settlement of adjacent bridge piers, uneven settlement of adjacent bridge foundation; d) uneven settlement of adjacent bridge foundation on the same bridge pier must be strictly controlled to avoid affecting the service life of hard foam board.
Application of FRA’s Noise Guidelines to HSR
Authors: Hanson Carl E.
Published: November 2010

Federal Railroad Administration (FRA) sponsored a comprehensive analysis of high speed rail noise and vibration resulting in the guidance manual, “High-Speed Ground Transportation Noise and Vibration Impact Assessment,” dated October 2005. This manual was prepared to provide a standardized set of procedures for the evaluation of noise and vibration impacts in recognition of community concerns in the vicinity of proposed projects. This paper by the lead author of the FRA manual presents the application of the methods to HSR projects.
Influencing Factors of Dynamic Performance of Jointless Turnout on Bridge in High-Speed Railway
Authors: Chen R. , Wang P. , Chen X. P.
Published: November 2010

Taking the case of 18# turnout (350km/h) laid on 6×32m continuous girder, a dynamic model for coupling system of vehicle and jointless turnout on bridge was established to analyze the factors that affected dynamic performance of jointless turnout on bridge, and several aspects were taken into consideration, i.e. train’s running quality, rail stress of turnout, vibration of turnout and bridge, and deformation, etc. It is shown that influenced by vibration and deformation of bridge, the train, turnout and bridge form a coupling vibration system, whose dynamic responses are stronger than those caused by train/turnout interaction on subgrade. Wheel/rail contact of turnout zone (especially the frog) has great effect on dynamic responses of jointless turnout on bridge, thus the nose rail height of frog should be optimized to mitigate the wheel load transition and its longitudinal gradient. When a train is passing a jointless turnout on bridge, a reasonable vertical stiffness for bridge is the key to keep its safety and comfort; as for the 32m continuous girder, the ratio of deflection to span should be ≤1/9000 under the ZK load (Chinese standard).
Dynamic Assessment of Ballastless Track Stiffness and Settlement in High-Speed Railway
Authors: Wang P. , Chen R. , Chen X. P.
Published: November 2010

Although ballastless track has such advantages as less maintenance and high stability, its big rigidity results in a strong wheel/rail dynamic interaction. In order to study a reasonable stiffness and uneven settlement limit for ballastless track and to optimize the dynamic performance of ballastless track under condition of high-speed running, vehicle together with ballastless track was viewed as an entire coupling system in this study. By adopting numerical simulation, we studied how the stiffness of foundation under rail and uneven settlement of subgrade influence the wheel/rail dynamic interaction. The results show that the reasonable stiffness of foundation under rail is within a range of 20∼30kN/mm, accordingly with a rail deformation within 1.3 ∼ 1.7mm. Through its dynamic analysis under different wavelengths and amplitudes, the uneven settlement of subgrade should be ≤L/1000.
Case Studies Determining the Effects of Track Stiffness on Vehicle Dynamics
Authors: Lu Sheng , Duan Haoliang , Greisen Curt , Farritor Shane , Arnold Richard , Hogan Cory , Dick Matthew , Fateh Mahmood , Carr Gary
Published: November 2010

Vehicle/Track dynamic simulation programs are now used routinely in the rail industry in areas such as vehicle and track design, derailment investigation, and prediction of vehicle/track behavior under a variety of conditions. In these investigations the accuracy and validity of the simulation highly depends on information input into the program pertaining to both the vehicle and the track. Track geometry cars provide a variety of track measurements which are used to characterize the track (e.g. gage, cross level, profile, curvature, etc.) but these measurements do not include track stiffness information. For lack of better data these simulations generally assume constant track stiffness and this can lead to significant inaccuracy. The University of Nebraska (UNL), under sponsorship from the Federal Railroad Administration, has developed a method to estimate vertical track deflection and stiffness from a rail car traveling at revenue speed. The system has been tested on thousands of miles of track. It is believed that these vertical track stiffness estimates, along with the standard track geometry data can now be used to improve vehicle/track simulation results. In this paper, sites from recent testing of the University of Nebraska system were chosen to be studied with the vehicle dynamics software VAMPIRE®. These case studies demonstrate scenarios where the variation of track stiffness may significantly affect vehicle dynamics performance in different aspects. Results suggest that wheel unloading may be increased by up to 20% by the inclusion of vertical stiffness data in the simulations. Car body vibration and dynamic wheel loads also tend to be affected by the stiffness variation. The proposed approach has limitations because stiffness estimates are made without direct measurements of wheel loads which leads to possible errors in the estimate. Also, the inadequacy of the Winkler model used in the process of stiffness estimation may also cause some inaccuracies. These limitations are further explored in this paper.
Augmentation of Level Crossing Safety Using Real-Time Video and Numerical Warning System
Authors: Ku Bih-Yuan
Published: November 2010

Official statistics showed that more than half of level crossing accidents in Taiwan were caused by intrusion of road users violating the right-of-way of the railroad. Thus it is critical that addition measures be developed to prevent or mitigate the seriousness of intrusion incidences even though many warning facilities are already in place. In this paper we propose to use real-time crossing cite image to provide train drivers with more vital information than alarm signals. In addition, we also take advantage of the radio link capacity to display numerical information of train distance on the fly to deter potential intrusion attempts. The result of this project can be used as reference design for the augmentation of level crossing safety of rail systems facing similar intrusion problems.
Critical Logistics Support Enables Fast Track Construction for High Speed Rail
Authors: Blaze James R. , Gowan Jay , Byers Stephen
Published: November 2010

Paper and PowerPoint presentation format will describe process for much faster logistics and construction management of new high speed track construction and improvement of existing FRA track from FRA Class 4 to Class 5 and Class 6 standards on existing freight railway lines. This process involves an integration of the long materials supply chain together with rapid process state of the art construction machines. These machines have been used in both European and Chinese high speed construction projects. Huge gains in new track kilometers and miles per day have been made in the last decade on the machinery side of the equation. The authors will show several case studies. The critical key to these production rates has been in the integration of materials ordering and prepositioning. The economic advantage is that track time construction windows that delay other passing trains can be reduced at tremendous savings in service and operational costs to the operators already providing service in these new high speed corridors and construction zones. Examples and calculations are shown.
Strategic Capacity Planning Process for Intercity Passenger Rail
Authors: Lai Yung-Cheng Rex , Shih Mei-Cheng
Published: November 2010

The demand for railway transportation is expected to be significantly increased worldwide; hence railway agencies are looking for better tools to allocate their capital investments on capacity planning in the best possible way. We presented a capacity planning process to help planners enumerate possible expansion options and determine the optimal network investment plan to meet the future demand. This process was applied to the conventional railway system in Taiwan to demonstrate its potential use. Using this capacity planning process will help railway agencies maximize their return from capacity expansion projects and thus be better able to provide reliable service to their customers, and return on shareholder investment.
Study on Calibration and Noise-Reduction of Track Inspection Car in Detecting Data
Authors: Jia Chaolong , Xu Weixiang , Liu Xumin
Published: November 2010

The condition of line equipment that track inspection car (or track recording car. which test geometry data of track, consist track gauge, cross level, longitudinal level, track alignment, twist, etc) examines has the attribute of high authenticity; as a result, it is an important way to obtain the true state of the track. However, this method also meets the problem of mileage excursion and noisy data. This paper employs the theoretical of gray relevancy of gray systems to analyze the waveform data that track inspection car examines, and makes corrections to mileage excursion, and then gets rid of the noisy data using the method of wavelet transform, so that the real track detecting data about track state can be achieved. This paper also makes the comparison between the effects of three threshold values in reducing noises, and pointed out their respective advantages and disadvantages.
Forecasting of the Track State Using BP Neural Network Based on Kalman Filtering
Authors: Jia Chaolong , Xu Weixiang , Liu Xumin
Published: November 2010

The combination of Kalman filtering technology and artificial neural networks technology has provided a new method for forecasting the changes of track geometry state. This article has established a forecasting model for the track geometry state of BP neural network based on Kalman filtering. The author analyzed some track detecting data of Chengdu-Kunming railway line of Kunming Railway Bureau, and made the state forecast based on this model. Simulation result showed that the application of BP neural network algorithm based on Kalman filtering in forecasting rail state has very high accuracy. The experiment showed that the application of this technology could forecast changes of the track geometry state in advance, and could make in-time adjustment to the track maintenance service work. Thus it is an effective measure for maintaining track geometry state in the best condition.
Squat Treatment by Way of Minimum Action Based on Early Detection to Reduce Life Cycle Costs
Authors: Li Zili , Molodova Marija , Zhao Xin , Dollevoet Rolf
Published: November 2010

Squats are a type of rolling contact fatigue on the top of rails of straight tracks or shallow curves. In some countries they have become a major type of rail damage. Although it is widely recognized that preventive and early corrective actions are cheaper than late remedies such as rail replacement, timely treatment is hindered by the lack of automatic detection of early squats. So far, the treatment of squats has mainly been dependent on ultrasonic detection, which detects deep cracks and is applicable only to severe squats. The life cycle costs (LCC) of squat-infected track are therefore high. The operational safety and availability of the networks are also adversely affected. Based on a new method which detects initiating squats, this paper proposes a methodology for squat related LCC reduction. First a squat classification is introduced that facilitates early identification of squats. Then the growth phases of squats are discussed; typical growth rate of squats is analyzed, and thereupon based threshold values for minimum action by rail grinding are proposed. After a review of the currently available detection methods, the new detection method is presented, with results of field test demonstrating the capability of the method to detect light squats. Finally, a case study of the LCC of a monitored squat-infected track section shows that the proposed treatment can significantly reduce the LCC. In addition, operational safety and network availability can also be improved.
Modeling Structural Flexibility in Railroad Vehicle Systems
Authors: Rathod Cheta , Shabana Ahmed A.
Published: November 2010

This paper presents a nonlinear finite element formulation for modeling the structural flexibility in multibody railroad vehicle systems. The formulation presented in this paper allows for modeling the structural flexibilities of the pantograph/catenary system, car body, and the track structure as well as their coupling with the dynamics of other components of high speed rail systems. The main outcome of this study is the development of a procedure that allows building a complex track or car body models that include significant details using a finite element preprocessor computer program. For example, the proposed method allows for developing at a preprocessing stage a track model that includes significant details and accounts for the effects of ties, fasteners, ballast, etc. The detailed track or car body model is used as an input to the general purpose flexible multibody computer program for a nonlinear analysis that accounts for the dynamic coupling between the track and car body flexibility and the vehicle coordinates. In order to achieve this goal, two different types of interpolations are used in the kinematic equations developed in this study; the geometry interpolation and the deformation interpolation. In the proposed formulations, the rails can have arbitrary geometry which is described using the isoparametric geometric interpolation. The coordinates of the polynomials used in this interpolation represent constant position and gradients coordinates, which are used to describe accurately the rail geometry. On the other hand, the rail deflections as well as car body deformations are described using the deformation interpolation and the nonlinear finite element floating frame of reference formulation. In the formulation proposed in this paper, the rail tangent and normal vectors as well as other geometric parameters such as the curvature and torsion at the wheel/rail contact points are expressed in terms of the rail deformation coordinates. The nonlinear dynamic coupling between the rail geometry and the vehicle dynamics is also considered in the formulation proposed in this paper. In particular, the longitudinal, lateral and spin creepages are expressed in terms of the track displacements which are the result of the wheel/rail contact forces. This nonlinear coupled analysis allows for more accurate prediction of the railroad vehicle dynamics. This paper also proposes a new efficient finite segment method based on the concept of rigid finite element to model track structure. Numerical results are presented in order to demonstrate the use of the formulation proposed in this study.
Speed-Up Technologies of China’s Existing Railways
Authors: Li Jun , Zhang Caichun
Published: November 2010

The paper describes the speed-up strategies on CR (China Railway) existing lines and rescheduling work on train working diagrams in the previous six rounds of speed-up campaigns, and it presents the speed-up technologies such as track improvement, communication and signaling, traction power supply, locomotive and rolling stocks, traffic organization and safety management. It also introduces the significant economic and social benefits generated from the train speed-increase on the existing lines as well as technical preparation provided for large-scale construction of high speed lines from the aspects of strengthening safety foundation, expanding capacity of railway network, enhancing transport efficiency, adding transport service products and improving service quality.
Field Investigations on Rolling Stock Components Designed to Overcome Low Adhesion Related Problems
Authors: Arias-Cuevas Oscar , Li Zili
Published: November 2010

The tangential force that a braking or tractive wheel can exert on a rail is limited by the friction coefficient available at the surfaces in contact for a given normal load. In clean steel-on-steel contacts the friction coefficient is known to be higher than the adhesion requirements of the majority of the existent rolling stock. However, in the presence of contamination (e.g. leaves, water, grease, and rust) the friction level can decrease to values far below those required in normal traction and braking operations. In particular, fallen leaves have been identified by many railways to cause considerable low adhesion problems in autumn. Despite the available countermeasures the adhesion problems still seem to persist in the majority of the affected networks. This could to a large extent be due to the lack of fundamental understanding on the effectiveness of the countermeasures used under different operating conditions. In this paper, the effectiveness of two rolling stock components, namely locomotive sanders and permanent magnetic track brakes, in leaf contaminated contacts is investigated by means of full-scale tests in a stabling yard. An electrical locomotive has been used to asses the performance of the sanders, whereas the tests with permanent magnetic track brakes have been carried out with an electrical multiple unit.
First for Repairs, Then for Damages: Environmental Liability and Environmental Stewardship in Railroad Stock Prices
Authors: McLaughlin Patrick A.
Published: November 2010

Using event study techniques, I test capital market reactions to environmental damages caused by hazardous materials (hazmat) spills in train accidents. Controlling for property damages, human injuries and lives lost, and other relevant factors, I find that the average hazmat spill is correlated with a small but statistically significant decrease in the daily stock return of the railroad involved in the spill. Further, by exploiting an exogenous change in maximum legal environmental damages liability, I test whether this market reaction to hazmat spills reflects incorporation of damages to ecosystem services into firm liability or, alternatively, reflects the importance of environmental stewardship in the valuation of firm goodwill, or both. The results, while not conclusive, indicate that at least some, but not all, of the negative reaction to hazmat spills stems from investor valuation of environmental stewardship, as opposed to investor concern for liability for environmental damages.
Experimental Study on the Ballast Pick-Up Problem in High Speed Trains
Authors: Navarro-Medina Fermin , Sanz-Andres Angel , Perez-Grande Isabel
Published: November 2010

A new theoretical approach on the determination of the conditions for the initiation of the motion of the ballast stones due to the wind gust created under the high-speed trains has been recently developed (Sanz-Andres & Navarro-Medina, 2009). This determination is critical to predict the starting of ballast pick-up, because once the motion is initiated a saltation-like chain reaction could take place. Sometimes the flying stones reach an height which is larger than the lowest parts of the train, striking them (and the track surroundings) producing considerable damage that are to be avoided e.g. by limiting the maximum allowed operational train speed. The aim of this contribution is to present the experimental results that have been obtained to check the validity of the proposed model. The experimental facility is a wind tunnel, with a gust generator, with a maximum wind speed of some 20 m/s (65.6 ft/s) and 10 Hz gust frequency. The test section is 0.39 m × 0.54 m (15.4 in × 21.3 in), which is suitable to perform experiments with stone models. It is shown that in the range of parameters explored, the experimental results are in good agreement with the theoretical model predictions. In this contribution the theoretical model is summarized, the experimental facility is described, showing some of its typical performances, the experimental procedure is outlined, and the experimental results are compared with the theoretical predictions.
Prediction of the Thermal Stability of Wheel Under Frequent Braking for Urban Rail Vehicle
Authors: Yu Zhizhuang , Wang Yong , Zuo Jianyong , Han Bin , Gu Leilei
Published: November 2010

A train is braked to stop when it reaches every station in an urban rail transit network. The combination of electro-pneumatic braking is currently adopted for many trains in China. The electric braking is manipulated prior to pneumatic braking. In the case of electric braking failure, the pneumatic braking device will then be used to perform ultimate protection. A typical pneumatic braking device includes a wheel and brake shoe. The work status of the wheel will certainly affect the running of train in frequent braking. In this paper, the authors established a three-dimensional finite element model (FEM) of wheel to simulate the three-dimensional transient temperature fields of the wheel at different running velocities and braking deceleration conditions. In addition, we analyzed the thermal stability of the wheel. Finally, we calculated the safety-related running velocity and braking deceleration. The results of the calculation are aimed to provide useful guidance for the urban rail operation in Chinese major cities. We recommend that the urban train speed should be lower than 60km/h when only the pneumatic braking device is used for braking.
Wheel-Rail Dynamic Model and Stochastic Analysis of the Friction in the Contact Patch
Authors: Lee HyunWook , Sandu Corina , Holton Carvel
Published: November 2010

The coefficient of friction (CoF) is one of the most important parameters for characterizing the contact between the wheel and the rail. The assumption of a constant CoF is still used in most theoretical studies, although experimental work indicates that the CoF depends on material and dynamic parameters. In the real world, accurate estimation of the CoF is not simple due to various uncertainties. In this paper we present a new 3D nonlinear dry CoF model at the wheel-rail contact. In addition, a stochastic analysis using the polynomial chaos theory is performed with the CoF model. The maximum amplitude of rail roughness and the lateral displacement of the wheel are considered as uncertain parameters in this study. One of the novelties in this study is that our CoF model captures the maximum CoF value (an initial peak) when the wheel starts to move. The stochastic analysis results show that the CoF probability density function (PDF) of a combination of two uncertain parameters has wider PDF ranges than the PDF obtained for only one uncertain parameter. The current work demonstrates that the CoF is strongly affected by the stochastic variation of dynamic parameters. In reality, the CoF is critical to rail tractive performance and efficiency. Thus, the PDF distribution of the CoF must be accounted for in the design of the wheel-rail system.