Relevant bibliographies by topics / Rail contact

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Rail contact'

Author: Grafiati
Published: 4 June 2021
Last updated: 19 February 2023

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Journal articles on the topic "Rail contact"

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Chen, Zhi Wei, Linan Li, Shi Gang Sun, and Jun Long Zhou. "Wheel-Rail Multi-Point Contact Method for Railway Turnouts." Applied Mechanics and Materials 97-98 (September 2011): 378–81. http://dx.doi.org/10.4028/www.scientific.net/amm.97-98.378.

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A calculation method of wheel-rail multi-point contact based on the elastic contact model is introduced. Moreover, the simulation calculation of vehicles passing through branch lines of No.18 turnouts is carried out. The result showed that the acute change of wheel-rail normal force caused by the transfers of wheel-rail contact point between two rails can be avoid by wheel-rail multi-point contact method, and the transfers of wheel-rail normal force between two rails is smoother. The validity of wheel-rail multi-point contact method is verified.
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Kumar, S., and S. P. Singh. "Rail Head Geometry, Rail Rolling and Wheel-Rail Contact Tilting Analysis for Heavy Axle Loads." Journal of Engineering for Industry 111, no. 4 (November 1, 1989): 375–81. http://dx.doi.org/10.1115/1.3188775.

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This paper presents analytical considerations which are important to design a rail head for reducing rail damage due to heavy axle loads. There are two important parameters of design of rail crown: (1) the wheel tread rail crown contact stress and (2) the contact tilt angle called the β angle. Contact should not be allowed to move out of the rail crown. Analysis of lateral oscillations of new and worn wheel sets shows that they do not impose an engineering constraint on the choice of rail crown radius. Rail rolling on curves due to lateral creepage forces is however of great importance in rail loading and stresses. The point of contact location is significantly affected by such roll. For the two commonly used rails, 132 RE and 136 RE, this roll results in the contact moving to the part of the rail head with radius of 1 1/4 in. Such movement of the contact also develops rapidly when hollowed worn wheels roll on flattened worn rails. It is pointed out that this condition results in forces higher than the wheel load and stresses more than twice the value developed when the contact is within the rail crown and that this is most likely responsible for many of the rail failure problems including cracking, shelling, and fractures. A design analysis of rail crown including Hertzian contact and rail twist considerations shows that none of the three current rails analyzed satisfy the criteria developed for good rail head design. A suitable ellipitical crown should prove better. Finally a systems approach to rail wheel interaction with a number of design recommendations is given.
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Ma, Xiaochuan, Ping Wang, Jingmang Xu, and Rong Chen. "Effect of the vertical relative motion of stock/switch rails on wheel–rail contact mechanics in switch panel of railway turnout." Advances in Mechanical Engineering 10, no. 7 (July 2018): 168781401879065. http://dx.doi.org/10.1177/1687814018790659.

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In order to enable the vehicle to change among the tracks, the stock and switch rails are separated and provided with different rail resilience levels on the baseplate in the railway turnout switch panel. Therefore, there will be vertical relative motion between stock/switch rails under wheel loads, and the relative motion will change the combined profile of stock/switch rails and consequently affect the wheel–rail contact mechanics. A method is developed in this article to investigate the effect of the relative motion of stock/switch rails on the wheel–rail contact mechanics along the railway turnout switch panel. First, the possible rigid wheel–rail contact points, called primary and secondary stock/switch rail contact points, are calculated based on the trace line method; second, the actual contact points are determined by the presented equations; finally, the distribution of wheel–rail contact forces on the stock/switch rails is obtained based on the continuity of interface displacements and forces. A numerical example is presented in order to investigate the effect of the relative motion of stock/switch rails on the wheel–rail contact points, stresses, and forces, and the results are presented and discussed.
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Seo, Jung Won, Hyun Kyu Jun, Seok Jin Kwon, and Dong Hyeong Lee. "Rolling Contact Fatigue and Wear Behavior of Rail Steel under Dry Rolling-Sliding Contact Condition." Advanced Materials Research 891-892 (March 2014): 1545–50. http://dx.doi.org/10.4028/www.scientific.net/amr.891-892.1545.

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Rolling contact fatigue and wear of rails are inevitable problems for railway system due to wheel and rail contact. Increased rail wear and increased fatigue damage such as shelling, head check, etc. require more frequent rail exchanges and more maintenance cost. The fatigue crack growth and wear forming on the contact surface are affected by a variety of parameters, such as vertical and traction load, friction coefficient on the surface. Also, wear and crack growth are not independent, but interact on each other. Surface cracks are removed by wear, which can be beneficial for rail, however too much wear shortens the life of rail. Therfore, it is important to understand contact fatigue and wear mechanism in rail steels according to a variety of parameters. In this study, we have investigated fatigue and wear characteriscs of rail steel using twin disc testing. Also the comparative wear behavior of KS60 and UIC 60 rail steel under dry rolling-sliding contact was performed.
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Li, Yang, JinJie Chen, JianXi Wang, Hu Zhao, and Long Chen. "Study on the residual stress distribution of railway rails." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 23 (May 28, 2020): 4682–94. http://dx.doi.org/10.1177/0954406220927069.

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Rolling contact fatigue damage of rails is significantly influenced by residual stresses. A three-dimensional elastic-plastic finite element model of wheel–rail contact was established in the present study, and the influence of initial stresses resulting from rail manufacturing process on the residual stress distribution of rails was analyzed. The repeated rolling passes were simulated and the stable residual stress distribution of rails was obtained. The influence of factors, such as wheel load, friction coefficient, and longitudinal creep rate, on the residual stress distribution of rails was investigated. It is found that within the limited special scale affected by the wheel–rail contact, the difference between the longitudinal residual stress with initial stresses applied and that without initial stresses applied becomes quite small once enough rolling passes have occurred (i.e., 10 rolling passes). When the initial stresses are applied, the longitudinal residual compressive stress on wheel–rail contact center of the rail is approximately 500 MPa. The residual compressive stress decreases with the increasing depth and changes from compression to tension at the depth of 6 mm beneath wheel–rail contact center of the rail. The wheel load mainly affects the residual stress distribution along the depth direction beneath rail surface. The friction coefficient mainly affects the residual stress distribution on the rail surface. The longitudinal creep rate has a great influence on the longitudinal residual stresses at the surface and along the depth of the rail.
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Zhou, Jian Hua, Yu Ji, An Chao Ren, and You Deng Zhang. "Analysis of the Generation Cause of Scale Shelling Defects on Running Surface of 60kg/m U71Mn Rail." Advanced Materials Research 291-294 (July 2011): 1062–68. http://dx.doi.org/10.4028/www.scientific.net/amr.291-294.1062.

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There were different degree scale shelling defects on running surface of 60kg/m U71Mn rail after used on the curve for a period of time, the characteristics and the generating reasons of the defects were analyzed, and the improvement measures were presented. There test results indicated that the scale shelling defects found on rail running surface were a sort of typical rolling contact fatigue damage, which caused mainly by the excessive contact stress, as a result of the wheel long-term contact with rail on the gauge corner of the rail on curve. It is effective to prevent and reduce rolling contact fatigue damage by following measures, such as improving the wheel/rail shape matching, and guaranteeing the wheel/rail interface locating on the rail tread center position, and strengthening the railway maintenance, and reasonable preventive grinding and corrective grinding for rails, and strict executing the system that rail grading use, the heat-treated rails should be used on small curve radius and heavy-load railway.
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Fajdiga, Gorazd, Matjaž Šraml, and Janez Kramar. "Modelling of Rolling Contact Fatigue of Rails." Key Engineering Materials 324-325 (November 2006): 987–90. http://dx.doi.org/10.4028/www.scientific.net/kem.324-325.987.

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Rail dark spot defect, also termed as squat failure or shelling, is a rolling contact fatigue failure which occurs frequently on the high speed traffic railway rails. The main goal of this study is to develop a computational model for simulation of the squat phenomena on rails in rail-wheel contact. The proposed computational model consists of two parts: (i) Contact Fatigue Crack Initiation (CFCI) and (ii) Contact Fatigue Crack Propagation (CFCP). The results of proposed unified model enable a computational prediction of a probable number of loading cycles that a wheel-rail system can sustain before development of the initial crack in the rail, as well as the number of loading cycles required for a crack to propagate from initial to critical length, when the final fatigue failure (squat) can be expected to occur.
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Wei, Kai, Rui Ying Chen, and Yu De Xu. "Rail Profile Wear on Curve and its Effect on Wheel-Rail Contact Geometry." Advanced Materials Research 779-780 (September 2013): 655–59. http://dx.doi.org/10.4028/www.scientific.net/amr.779-780.655.

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The paper has carried out continued tests on a curve of a heavy haul railway in China for its rail profiles. Based on the data, the paper has counted the development of the rail profile wear, and then analyses the influence of wheel-rail contact geometry on the rail profile wear. The results show that the wear of high rails develops around the rail corners, while the one of low rails around the rail top. The development of the rail wear speeds up after the transport mass passes 210MGT. The wheel-rail contact geometry deteriorates when the transport mass grows up to 60MGT and lower than 210MGT.
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Seo, Jung Won, Seok Jin Kwon, Hyun Kyu Jun, and Dong Hyung Lee. "Microstructure Features and Contact Fatigue Crack Growth on Rail." Materials Science Forum 654-656 (June 2010): 2491–94. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.2491.

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Rolling Contact Fatigue (RCF) damage on the surface of rails such a head check, squats is a growing problem. Since rail fractures can cause derailment with loss of life and property, the understanding of rail fracture mechanism is important for reducing damages on the rail surface. In this study, we have investigated RCF damage, fatigue growth and fracture surface morphology on the surface of broken rail using failure analysis and finite element (FE) analysis. The investigation indicates that the crack grows at about 20° to the depth of 8mm from the surface and branches into two cracks. One crack propagates downward at about 47°, the other propagates upward. Since the crack growth rate of the downward crack was faster than that of upward crack, rail eventually was broken. Since the downward branches lead to fracture of the rail, they are more dangerous to the integrity of rails. It has been observed that White Etching Layer (WEL) occurs within the surface of broken rail. It was found that the fatigue crack initiation and propagation was accelerated by WEL.
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Chen, Rui Ying, Kai Wei, and Yu De Xu. "Simulation Analysis on Wheel and Groove Rail Contact Position." Advanced Materials Research 779-780 (September 2013): 607–10. http://dx.doi.org/10.4028/www.scientific.net/amr.779-780.607.

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A vehicle-rail dynamic model is established and the calculated results are verified with trace method. And under the conditions of a same curve section, simulations are made on the contact position of groove rail and standard rail. Variation of contact points and contact area are analyzed. Furthermore, comparisons are made on the two rails with different lateral displacements.
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Dissertations / Theses on the topic "Rail contact"

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McNeal, Cedric J. "Barrel wear reduction in rail guns : the effects of known and controlled rail spacing on low voltage electrical contact and the hard chrome plating of copper-tungsten rail and pure copper rails /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Jun%5FMcNeal.pdf.

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Thesis (M.S. in Applied Physics)--Naval Postgraduate School, June 2003.
Thesis advisor(s): William B. Maier II, Richard Harkins. Includes bibliographical references (p. 45-46). Also available online.
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Smith, Lindsey. "Rolling contact fatigue in wheel-rail contact." Thesis, University of Newcastle Upon Tyne, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.438385.

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Zhu, Yi. "Adhesion in the wheel-rail contact." Doctoral thesis, KTH, Tribologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-133342.

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To attract more customers and compete with other modes of transportation, railway transport needs to ensure safety, punctuality, high comfort, and low cost; wheel–rail adhesion, i.e., the transmitted tangential force in the longitudinal direction during driving and braking, plays an important role in all these aspects. Adhesion needs to be kept at a certain level for railway operation and maintenance. However, wheel−rail contact is an open system contact. Different contaminants can present between the wheel and rail surfaces, forming a third-body layer that affects the adhesion. Prediction of wheel–rail adhesion is important for railway operations and research into vehicle dynamics; however, this prediction is difficult because of the presence of contaminants. This thesis deals with wheel–rail adhesion from a tribological perspective. The five appended papers discuss wheel–rail adhesion in terms of dry conditions, lubricated conditions, leaf contamination, iron oxides, and environmental conditions. The research methodologies used are numerical modelling, scaled laboratory experiments, and field tests. The research objective is to understand the mechanisms of the adhesion loss phenomenon.  A numerical model was developed to predict wheel–rail adhesion based on real measured 3D surfaces. Computer simulation indicates that surface topography has a larger impact on lubricated than on dry contacts. Plastic deformation in asperities is found to be very important in the model. Ball-on-disc tests indicate that water can give an extremely low adhesion coefficient on smooth surfaces, possibly due to surface oxidation. Investigation of lubricated contacts at low speed indicates that oil reduces the adhesion coefficient by carrying a normal load, while adhesion loss due to water depends on the surface topography, water temperature, and surface oxidation. A field investigation indicates that leaves reduce the friction coefficient because of the chemical reaction between leaves and bulk materials. The thickness of the surface oxide layer was found to be an essential factor determining adhesion reduction. Pin-on-disc experiments found a transition in the friction coefficient with regard to the relative humidity, due to a trade-off between the water molecule film and the hematite on the surface.

QC 20131031

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Saulot, Aurélien Berthier Yves Descartes Sylvie. "Analyse tribologique du contact roue-rail." Villeurbanne : Doc'INSA, 2006. http://docinsa.insa-lyon.fr/these/pont.php?id=saulot.

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Galas, Radovan. "Friction Modification within Wheel-Rail Contact." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-367508.

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Předložená disertační práce se zabývá experimentálním studiem modifikátorů tření a maziv pro temeno kolejnice, které jsou aplikovány do kontaktu kola a kolejnice za účelem optimalizace adheze a redukce hluku. Hlavním cílem práce bylo objasnit vliv aplikovaného množství a složení těchto látek na adhezi v kontaktu. Hlavní pozornost byla věnována zejména potencionálním hrozbám souvisejících s kriticky nízkou adhezí, která může nastat po aplikaci těchto látek. Experimentální studium probíhalo v laboratorních i reálných podmínkách, konkrétně v tramvajovém provozu. V případě laboratorních experimentů byl využit komerční tribometr a dvoudiskové zařízení umožňující simulovat průjezd vozidla traťovým obloukem. Kromě samotné adheze bylo při experimentech sledováno také opotřebení a míra hluku. Výsledky ukázaly, že maziva pro temeno kolejnice jsou schopna poskytovat požadované třecí vlastnosti, nicméně jejich chování je silně závislé na aplikovaném množství. V případě předávkování kontaktu dochází ke kriticky nízkým hodnotám adheze, které vedou k výraznému prodloužení brzdné dráhy. V případě modifikátorů tření bylo ukázáno, že chování těchto látek je výrazně ovlivněno odpařováním základního média. Výsledky také ukázaly, že nadměrné množství částic pro modifikaci tření může způsobit kriticky nízké hodnoty adheze. U obou výše zmíněných typů produktů byl prokázán pozitivní vliv na míru opotřebení a míru poškození povrchu, zatímco významná redukce hluku byla dosažena pouze v případech, kdy došlo ke značnému poklesu adheze. V závěru této práce jsou uvedena doporučení pro další výzkumné aktivity v této oblasti.
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Pang, Tao, and tony_pang@hotmail com. "Studies on Wheel/Rail Contact – Impact Forces at Insulated Rail Joints." Central Queensland University. Centre for Railway Engineering, 2008. http://library-resources.cqu.edu.au./thesis/adt-QCQU/public/adt-QCQU20080410.154708.

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To investigate the wheel/rail contact impact forces at insulated rail joints (IRJs), a three-dimensional finite element model and strain gauged experiments are employed and reported in this thesis. The 3D wheel/rail contact-impact FE model adopts a two-stage analysis strategy in which the wheel-IRJ railhead contact is first established in the static analysis and the results transferred to dynamic analysis for impact simulations. The explicit FE method was employed in the dynamic analysis. The Lagrange Multiplier method and the Penalty method for contact constraint enforcement were adopted for the static and dynamic analyses respectively. The wheel/rail contact-impact in the vicinity of the end post is exhibited via numerical examples from the FE modelling. The wheel/rail contact impact mechanism is investigated. The strain gauged experiments which consist of a lab test and a field test are reported. The signature of the strain time series from the field test demonstrates a plausible record of the dynamic responses due to the wheel/rail contact impact. By using the experimental data, both the static and the dynamic FE models are validated. It is found that the stiffness discontinuity of the IRJ structure causes a running surface geometry discontinuity during the wheel passages which then causes the impact in the vicinity of the end post. Through a series of sensitivity studies of several IRJ design parameters, it is shown that the IRJ performance can be effectively improved with optimised design parameters.
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Martin, Michael. "The Effect of Geometrical Contact Input to Wheel-Rail Contact Model." Thesis, KTH, Spårfordon, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-239735.

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Wheel-rail contact is an important aspect of railway, the forces transferred between the wheel and rail are the one that guide, brake, or accelerate the train, and that is why the understanding of the contact between wheel and rail is an interesting research topic. In this master thesis wheel-rail contact model named ANALYN is used to see the effect of the different geometrical input, like undeformed distance, relative longitudinal curvature, and relative lateral curvature calculation affect the contact patch estimation formed at the wheel-rail contact.  In the process, a geometrical contact search code is made to find the contact point between wheel and rail for certain lateral displacement, yaw angle, and roll angle of the wheelset. The codes used to calculate the three geometrical inputs are also prepared, with two methods are prepared for each input. The results that generated from combination of the geometrical contact search and geometrical input preparation are used as the input to ANALYN. The results showed that different geometrical input calculations do affect the shape of the contact patch, with the calculation of lateral curvature being the most important since it affects the shape of the contact patch greater than other geometrical inputs. It is also shown that taking yaw angle into account in the contact search will affect the shape of the contact patch.
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Wickramasinghe, Munidasa Widhana Pathiranage Isuru Udara. "Investigation of surface ratchetting due to rail/wheel contact." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/67800/1/Munidasa%20Widhana%20Pathiranage%20Isuru%20Udara_Wickramasinghe_Thesis.pdf.

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This project advances the knowledge of rail wear and crack formation due to rail/wheel contact in Australian heavy-haul railway lines. This comprehensive study utilised numerous techniques including: simulation using a twin-disk test-rig, scanning electron microscope particle analysis and finite element modeling for material failure prediction. Through this work, new material failure models have been developed which may be used to predict the lifetime and reliability of materials undergoing severe contact conditions.
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Duan, FangFang. "Numerical tribology of the wheel-rail contact : Application to corrugation defect." Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0019/document.

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Depuis plus d'un siècle, l’usure ondulatoire représente un des problèmes de maintenance les plus important pour les réseaux ferroviaires. Celle-ci est à l’origine d’émissions sonores incommodantes pour le voisinage et de vibrations structurelles pouvant réduire la durée de vie des infrastructures et matériels ferroviaires. Ce phénomène périodique présent à la surface des rails est intimement lié à la dynamique du contact roue-rail qui résulte des paramètres régissant le frottement, la dynamique du train et de la voie… Afin de mieux appréhender les conditions menant à l’apparition de l’usure ondulation, un modèle numérique a été proposé pour compenser l’impossibilité d’instrumenter localement et de façon fiable un contact roue-rail dynamiquement. Tout d'abord, un outil approprié a été choisi pour modéliser la dynamique du contact roue-rail afin de reproduire numérique de l’usure ondulatoire des voies rectilignes. Le code d'éléments finis dynamique implicite Abaqus a été choisi pour instrumenter numériquement localement le contact roue-rail. Ainsi, tant l'origine que l'évolution de l’usure ondulatoire dans des phases transitoires (accélération / décélération) sont étudiées. Une étude de sensibilité a été menée pour mettre en évidence la sensibilité de l’usure ondulatoire apparaissant dans des conditions transitoires au passage d’une ou plusieurs roues ainsi que d’un défaut géométrique présent à la surface du rail. Des conditions dynamiques locales d’adhérence-glissement (stick-slip), liées à la dynamique de la roue et du rail couplés par le contact, est identifié comme origine de l’usure ondulatoire des voies rectilignes dans des conditions transitoires. Deuxièmement, les résultats obtenues avec le modèles précédent ont mis en évidence une décroissance de l’amplitude de l’usure ondulatoire reproduire numérique en fonction du nombre de roue passant sur le rail. Ce résultat semble être en contradiction avec les observations de rails réels. Ce problème est lié à la difficulté de gérer la dynamique de contact, et tout particulièrement dans le cas où il y a des impacts locaux, dans les modèles éléments finis classiques tels que ceux implémentés dans Abaqus. Pour palier ce problème, une méthode de masser redistribuée a été implémentée dans Abaqus et utilisée sur le cas précédent. Les résultats montrent un accroissement plus réaliste de l’usure ondulatoire en fonction du nombre de roues
For more than a century, rail corrugation has been exposed as one of the most serious problems experienced in railway networks. It also comes with a series of problems for maintenance, such as rolling noises and structural vibrations that can reduce lifetime of both train and track. This periodical phenomenon on rail surface is closely linked to wheel-rail contact dynamic, which depends on friction, train dynamics… To better understand corrugation birth conditions, a numerical model is suggested to complement the experimental limitations and to instrument a wheel-rail contact both locally and dynamically. At first, an appropriate tool was chosen to create the dynamic wheel-rail contact model to reproduce straight-track corrugation, also called “short-pitch” corrugation. The implicit dynamic finite element code Abaqus was chosen to investigate the dynamic local contact conditions. Both the origin and the evolution of straight-track corrugation under transient conditions (acceleration / deceleration) are studied. The parametrical sensibility of corrugation is thus investigated both with single/multiple wheel passing(s) and with geometric defect. A stick-slip phenomenon, linked to both wheel and rail dynamics coupled through the contact, is identified as the root of straight-track corrugation under transient conditions. Secondly, results obtained with the previous model have highlighted a quick decrease of corrugation amplitude with the increase of wheel passings over the rail. This last result seems to be in contradiction with reality. This problem comes from the difficulty to reliably manage contact dynamics, and particularly with local impacts, with the use of classical finite element models such as the one implemented in Abaqus. To compensate for this lack, a mass redistribution method is implemented in Abaqus and used with the previous case. The results show a more realistic corrugation growth according to the number of wheel passings
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Jon, Sundh. "On wear transitions in the wheel-rail contact." Doctoral thesis, KTH, Maskinkonstruktion (Avd.), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11563.

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Wear transitions in the wheel–rail contact are of increasing interest since the general trend in railway traffic is toward increased velocities and axle loads. Curving increases the risk of flanging, causing the contact to change from an almost pure rolling wheel tread–rail head contact to more of a sliding wheel flange–rail gauge contact on the high rail in curves. Under wheel flange–rail gauge contact conditions, wear transitions to severe or catastrophic wear will occur if the contact is improperly lubricated. Such a transition is the most undesirable transition in the wheel–rail contact, as it represents a very expensive operating condition for railway companies. The contact conditions responsible for this transition are very severe as regards sliding velocity and contact pressure, and thus place high demands on both the lubricant and the wheel and rail materials. The focus of this thesis is on the transitions between different wear regimes in a wheel–rail contact. Wear is discussed both in traditional tribological terms and in terms of the categories used in the railway business, namely mild, severe and catastrophic wear. Most of the work was experimental and was performed at the Royal Institute of Technology (KTH), Department of Machine Design. The effects of contact pressure, sliding velocity, and type of lubricant have been investigated, producing results that resemble those of other studies presented in the literature. The absence of research relating to the wheel flange–rail gauge contact is addressed, and it is concluded that a lubricant film must be present on rails in curves to prevent severe or catastrophic wear. The formulation of this lubricant can further increase its wear- and seizure-preventing properties. To obtain a deeper understanding of wear transitions, methods such as airborne particle measurement and electron microscopy have been used. Paper A presents the test methodology used to detect seizure and discusses the wear-reducing influence of free carbon in highly loaded contacts. Paper B presents the testing of seizure-initiating conditions for a range of environmentally adapted lubricants applied to wheel and rail materials; a transient pin-on-disc test methodology was used for the testing. Paper C presents the use of pin-on-disc methodology to study the wear-reducing effects of a wide range of lubricants. The best performing lubricant was a mineral oil containing EP and AW additives. Paper D relates wear rates and transitions to airborne particles generated by an experimentally simulated wheel–rail contact. The airborne particles generated varied in size distribution and amount with wear rate and mechanism. Paper E relates additional analysis techniques, such as FIB sectioning, ESCA analysis, airborne particle measurements, and SEM imaging of airborne wear particles, to the contact temperature.
QC 20100721
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Books on the topic "Rail contact"

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(Firm), Knovel, ed. Wheel-rail interface handbook. Boca Raton, FL: CRC Press, 2009.

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Bosso, Nicola. Mechatronic Modeling of Real-Time Wheel-Rail Contact. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013.

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Bosso, Nicola, Maksym Spiryagin, Antonio Gugliotta, and Aurelio Somà. Mechatronic Modeling of Real-Time Wheel-Rail Contact. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-36246-0.

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L, Grassie S., ed. Mechanics and fatigue in wheel/rail contact: Proceedings of the Third International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, Cambridge, U.K. July 22-26, 1990. Amsterdam: Elsevier, 1991.

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Association, International Heavy Haul. Guidelines to best practices for heavy haul railway operations: Wheel and rail interface issues. Virginia Beach, Va: International Heavy Haul Association, 2001.

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International Conference on Contact Mechanics and Wear of Rail/Wheel Systems (3rd 1990 Cambridge, UK). Papers presented at the ThirdInternational Conference on Contact Mechanics and Wear of Rail/Wheel Systems, Cambridge, UK, July 22-26, 1990. Edited by Dowson Duncan. Lausanne: Elsevier Sequoia, 1991.

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International Conference on Contact Mechanics and Wear of Rail/Wheel Systems (4th 1994 Vancouver, Canada). Papers presented at the 4th International Conference on Contact Mechanics and Wear of Rail-Wheel Systems, Vancouver, Canada, July 24-28, 1994. Edited by Kalousek J. Amsterdam: Elsevier, 1996.

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8

Wright, Harold. Light rail in the valley. Seattle, Wash: Classic Day Publishing, 2011.

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Zink, Daniel L. Effects of rail contract rates on North Dakota and Minnesota country grain elevators. [Fargo, N.D.]: Upper Great Plains Transportation Institute, 1987.

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Cellar, Horst. Untersuchung des Dämpfungsverhaltens der Schlupfstelle zwischen Rad und Schiene. Mülheim/Ruhr: Kirnberg-Verlag, 1989.

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Book chapters on the topic "Rail contact"

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Knothe, Klaus, and Sebastian Stichel. "Modeling of Wheel/Rail Contact." In Rail Vehicle Dynamics, 33–79. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-45376-7_3.

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Bosso, Nicola, Maksym Spiryagin, Antonio Gugliotta, and Aurelio Somà. "Contact Model." In Mechatronic Modeling of Real-Time Wheel-Rail Contact, 55–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-36246-0_5.

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Dhanasekar, Manicka, and Kan Ding. "Rolling Contact Fatigue in Rail – Insulated Rail Joints (IRJ)." In Encyclopedia of Tribology, 2910–15. Boston, MA: Springer US, 2013. http://dx.doi.org/10.1007/978-0-387-92897-5_292.

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Bosso, Nicola, Maksym Spiryagin, Antonio Gugliotta, and Aurelio Somà. "Review of Wheel-Rail Contact Models." In Mechatronic Modeling of Real-Time Wheel-Rail Contact, 5–19. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-36246-0_2.

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Głowacz, Michał, Marek Kaniewski, and Artur Rojek. "Overhead contact line systems for high-speed rails." In High-Speed Rail in Poland, 279–300. Leiden, The Netherlands ; Boca Raton : CRC Press/Balkema, [2018]: CRC Press, 2018. http://dx.doi.org/10.1201/9781351003308-11.

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Sehitoglu, Huseyin, and Y. Roger Jiang. "Residual Stress Analysis in Rolling Contact." In Rail Quality and Maintenance for Modern Railway Operation, 349–58. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8151-6_28.

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Dubourg, M. C., and J. J. Kalker. "Crack Behaviour under Rolling Contact Fatigue." In Rail Quality and Maintenance for Modern Railway Operation, 373–84. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8151-6_30.

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Piotrowski, J. "On an Approach to Prediction of Contact Loading of Rail for Two-Point Contact Between Wheel and Rail." In Rail Quality and Maintenance for Modern Railway Operation, 215–24. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8151-6_17.

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Marques, Filip, Hugo Magalhães, Joao Pombo, Jorge Ambrósio, and Paulo Flores. "Contact Detection Approach Between Wheel and Rail Surfaces." In New Trends in Mechanism and Machine Science, 405–12. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-55061-5_46.

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Kalker, J. J. "Computational Contact Mechanics of the Wheel-Rail System." In Rail Quality and Maintenance for Modern Railway Operation, 151–64. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-015-8151-6_13.

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Conference papers on the topic "Rail contact"

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Guan, Qinghua, Binbin Liu, and Stefano Bruni. "Effects of Non-Hertzian Contact Models on Derailment Simulation." In 2020 Joint Rail Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/jrc2020-8074.

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Abstract The derailment of trains is a complex phenomenon that requires an elaborate contact model in simulation to better understand its mechanism. The CONTACT program is a well-known reference for wheel-rail contact modeling due to its high accuracy. However, its low computational efficiency restricts its applications especially in the context of a multi-body simulation. Therefore, a high computational efficient, simplified and approximate non-Hertzian contact is preferred in derailment simulation. The aim of this research is to verify the efficiency of a recently developed non-Hertzian wheel-rail contact model in derailment simulation, which is a combination of the Kik-Piotrowski model and the KBTNH that is a fast creep force solver for non-Hertzian contacts. To assess the performance of the non-Hertzian model in derailment simulation, the derailment coefficient for steady-state and quasi-steady conditions, the wheel/rail contact forces during flange contact, and the dynamics behaviors of the wheelset prior to the derailment are compared with the state of the art contact methods representing different levels of modeling complexity, accuracy and efficiency, namely the classical approach (Hertz theory+FASTSIM algorithm) and the ‘exact’ solver CONTACT.
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Chen, Yung-Chuan, Jao-Hwa Kuang, Li-Wen Chen, Jiang-Che Shin, and Sing-You Lee. "Wheel-Rail Thermal Contact on Rail Corrugation During Wheel Braking." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-79859.

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This paper uses the finite element method to investigate the effect of rail corrugation on the wheel-rail thermal contact pressure and temperature distributions during wheel braking. Contact elements are used to simulate the contact between a wheel and a rail. Various friction coefficients, wavelengths and amplitudes of corrugated rails as well as braking times are considered in this study. The results indicate that, in the wheel-rail contact area, the rail corrugation affects the contact pressure and temperature distributions significantly. A modified equation with time-dependent heat partition factor is proposed to predict the rail surface temperature distribution for rails with smooth surfaces. Simulation results show that the proposed equation works very well. The results also indicate that the corrugated rail can lead to a wavy temperature distribution on the rail surface. Also, a smaller corrugated rail amplitude results in a higher maximum temperature near the trough region and a lower one near the crest region.
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Tunna, John. "Rolling Contact Fatigue in Passenger and Freight Railroads." In 2010 Joint Rail Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/jrc2010-36039.

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Rolling Contact Fatigue (RCF) can occur on wheels and rails in passenger and freight railroads. It can be a significant cost driver, and, if left untreated, it may lead to derailments. Tangential wheel-rail forces, creepage and contract stress are shown to be the causes of RCF. Improved vehicle curving performance and optimized wheel and rail profiles are shown to have benefits. Methods of managing RCF are preventive rail grinding and wheel turning. Improved wheel and rail materials can also have benefits. The paper includes examples of rail and wheel RCF in both passenger and freight railroads. References are given to other papers for further reading on this subject.
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Mason, Michael A., Charles P. Cartin, Parham Shahidi, John E. Speich, and James Hargraves. "Contact Stress Modeling in Railway Bearings for Imperfect Contact Geometries." In 2015 Joint Rail Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/jrc2015-5808.

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The connection between bearing raceway condition and fatigue in tapered roller bearings utilized in the railroad environment is of interest. Roller bearings for railroad applications are typically precision ground to exact dimensions with crowned contact geometries for optimal loading of components. This normally results in completely elastic Hertzian contact stresses under standard railcar loads with original equipment manufacturer raceway contact geometries. However, with extremely uneven bogie load distributions, impact damage, corrosion and spall repair, imperfect stress distributions can occur on bearing raceways utilized in the railroad environment. Railroad bearing applications in North America have the added complexity that the life of the product is not defined in the same way as in other industries. For example, the definition of spalling remains consistent across all industries and is outlined in the Association of American Railroads (AAR) Manual of Standards and Recommended Practices. However, an inconsistency compared to other industries is that the fatigue life of the product in the rail industry is not always considered complete at the first evidence of fatigue spalling. Although some other industries allow for the remanufacture and restoration of bearing assemblies, the aggressive raceway fatigue regrinding practices allowed by the AAR are not commonly permissible in other industries. These remanufacturing practices adversely influence subsurface stress magnitudes below the raceway surface, as they reduce the effective length of the raceway and can create stress risers. Engineering tools like the novel modeling method presented in this paper can be used by bearing designers to evaluate the impact of surface discontinuities, at the center or edge of the raceway, on the overall stress state of bearing raceways. For the various types of raceway conditions detailed above, a new tool was developed using finite element methods to simulate the stress state of the bearing under complex raceway contact geometries or adverse load conditions. The finite element contact stress tool was successfully validated using proven Hertzian contact theory. Peak maximum shear and von Mises subsurface stress predictions between the finite element model and conventional contact theory agreed within .001 inches, with regards to peak stress depth below the surface, and 10,000 psi, with regards to peak stress magnitude. This newly developed methodology will be used in future studies to analyze other load conditions and raceway contact geometries that cannot be analyzed with basic Hertzian contact theory, in order to illustrate practical application of the tool. Specifically, overload conditions are analyzed in the work presented. Furthermore, a proposed methodology for future work related to the examination of the stress state created by current AAR bearing reconditioning acceptance standards related to raceway impact damage and spall repair will be introduced.
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Sugiyama, Hiroyuki, and Yoshihiro Suda. "Hybrid Contact Search Algorithm for Wheel/Rail Contact Problems." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68588.

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In this investigation, the on-line and off-line hybrid contact algorithm for modeling wheel/rail contact problems is developed based on the elastic contact formulation. In the tabular contact search used in existing specialized railroad vehicle dynamics codes, contact points are predicted using an assumption of rigid contacts. For this reason, the contact points can be different from those predicted by the on-line based contact search used in general elastic contact formulations. The difference in the contact point becomes significant when flange contacts that have large contact angles are considered. In the hybrid algorithm developed in this investigation, the off-line tabular search is used for treating tread contacts, while the on-line iterative search is used for treating flange contacts. By so doing, a computationally efficient procedure is achieved while keeping accurate predictions of contact points on the wheel flange. Furthermore, the use of the proposed hybrid algorithm can eliminate the use of time-consuming on-line search procedures for the second points of contact as well. Since the location of second points of contact is pre-computed in the contact geometry analysis, the occurrence of two-point contact can be predicted using the look-up table in a straightforward manner. For the two-point contact scenarios encountered in curve negotiations, the online search is used for flange contacts, while the off-line search is used for tread contacts simultaneously. The on-line one-point contact search is also important for flange climb scenarios. It is demonstrated by several numerical examples that the proposed hybrid contact search algorithm can be effectively used for modeling wheel/rail contacts in the analysis of general multibody railroad vehicle systems.
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Spiryagin, Maksym, Sanjar Ahmad, Esteban Bernal, Kevin Oldknow, Ingemar Persson, Qing Wu, Colin Cole, and Tim Mcsweeney. "Implementation of the Contact Roughness at the Wheel-Rail Contact Model for Locomotive Traction Studies." In 2022 Joint Rail Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/jrc2022-84116.

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Abstract This paper introduces a solution to deliver the relation between the contour and real contact areas considering characteristics of surface geometry based on the adaptation of a tribological method [1] for calculation of the real area of contact and the real pressure between two rough surfaces. The implementation in the wheel-rail coupling architecture is kept the same as per the previously developed wheel-rail multibody couplings [2,3] based on the modified Fastsim [4] and Extended Contact [5] algorithms, which allows switching between the previous and new developed coupling for a comparative analysis. The results obtained, and limitations, are stated in this paper.
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Kudinov, D., and G. Shaydurov. "Non-contact nondestructive rail testing." In 2009 International Siberian Conference on Control and Communications (SIBCON 2009). IEEE, 2009. http://dx.doi.org/10.1109/sibcon.2009.5044873.

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Mariani, Stefano, Thompson V. Nguyen, Francesco Lanza di Scalea, and Mahmood Fateh. "High Speed Non-Contact Ultrasonic Guided Wave Inspections of Rails." In 2014 Joint Rail Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/jrc2014-3745.

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This paper describes a new system for high-speed and non-contact rail defect detection being developed at the University of California at San Diego (UCSD). A prototype using an ultrasonic air-coupled guided wave signal generation and air-coupled signal detection has been tested at the UCSD Rail Defect Farm. This solution presents an improvement over the previously considered laser/air-coupled hybrid system because it replaces the costly and hard-to-maintain laser with a much cheaper, faster, and easier-to-maintain air-coupled transmitter. In addition to a real-time statistical analysis algorithm, the prototype uses a specialized filtering approach to mitigate the inherently poor signal-to-noise ratio of the air-coupled ultrasonic measurements in rail steel. The laboratory results indicate that the prototype is able to detect internal rail defects with a high reliability. Various aspects of the prototype have been designed with the aid of numerical analyses. In particular, simulations of ultrasonic guided wave propagation in rails have been performed using a Local Interaction Simulation Approach (LISA) algorithm. Many of the system operating parameters were selected based on Receiver Operating Characteristic (ROC) curves, which provide a quantitative manner to evaluate different detection performances based on the trade-off between detection rate and false positive rate. Extensions of the system capability are planned to add rail surface characterization to the internal rail defect detection to optimize rail grinding operations.
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Sugiyama, Hiroyuki, and Yoshihiro Suda. "Wheel/Rail Two-Point Contact Geometry With Back-of-Flange Contact." In ASME 2007 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/detc2007-35151.

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In this investigation, a numerical procedure that can be used for the three-dimensional analysis of wheel and rail contact geometry is developed using the constraint contact formulation. The locations of contact points are determined for given lateral and yaw displacements of a wheelset when one-point contact is considered for each wheel, while these two displacements are no longer independent when the two-point contact occurs. A systematic procedure for predicting the flange as well as the back-of-flange contact points is developed and used for the two-point contact analysis of wheel and rail. Numerical results that involve tread, flange, and back-of-flange contacts are presented in order to demonstrate the use of the contact algorithm developed in this investigation. In particular, the back-of-flange contact is discussed for assessing contact configurations of wheel and grooved rail in Light Rail Vehicle (LRV) applications.
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Ku, Bih-Yuan, Jen-Sen Liu, and Ming-Jan Ko. "Quantitative Measurement of Pantograph Loss of Contact Dynamics." In 2013 Joint Rail Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/jrc2013-2439.

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In this paper we present our work on the development of a quantitative measurement advice to capture the dynamics of pantograph arcing during loss of contact. Despite the difficulties involved, it is very important for the railroad operators to accurately measure the pantograph loss-of-contact dynamics in order to assess the current collection quality of the pantograph with the overhead contact system during the commissioning phase and long-term operation. We use photovoltaic cells to construct a simple but effective sensor that can produce a voltage signal proportional to arc strength and duration, which can then be used as a precise quantitative measure of the loss of contact dynamics of the pantograph.
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Reports on the topic "Rail contact"

1

Schorung, Matthieu. A Geographical Contribution on Interurban Passenger Rail Transportation in the United States. Mineta Transportation Institute, February 2022. http://dx.doi.org/10.31979/mti.2022.2212.

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Why does the rail infrastructure of the United States lag behind those of many other developed countries? Where is U.S. high-speed rail? This research approaches this in a dilemma by exploring Amtrak’s traditional rail services and high-speed rail projects in the nation to understand the workings of public rail transportation policies, what they contain, and how they are developed and pursued by the different stakeholders. This research utilizes case studies and a multiscale approach to analyze the territorialization of intercity rail transportation policies. The analysis demonstrates the emergence of a bottom-up approach to projects, notably apparent in the California HSR project and in the modernization of the Cascades corridor. Furthermore, this research concluded that, first, the development of uniform arguments and recommendations to encourage new rail policies emphasizes structuring effects and economic role of high-speed rail, congestion reduction, modal shift. Second, a tangible though uneven pro-rail position exists among public actors at all levels. Stakeholders prioritize improving and modernizing existing corridors for the launch of higher-speed services, and then on hybrid networks that combine different types of infrastructures. Although there are no publicly backed projects for new lines exclusively dedicated to high-speed rail, most of the high-speed corridors are in fact “higher-speed” corridors, some of which are intended to become high-speed at some time in the future.
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Peterson, Eric, Wenbin Wei, and Lydon George. A Model for Integrating Rail Services with other Transportation Modalities: Identifying the Best Practices and the Gaps for California’s Next State Rail Plan. Mineta Transportation Institute, July 2021. http://dx.doi.org/10.31979/mti.2021.1949.

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The California State Rail Plan (CSRP) is among the best rail plan documents published by any jurisdiction in the United States to date. As such, the CSRP is used in this paper as the basis of comparison to other state rail service plans. These plans will have been submitted to the Federal Railroad Administration (FRA) on record as of June 2020—as required under Section 303 of the Passenger Rail Investment and Improvement Act (PRIIA) of 2008. The purpose of this paper is to identify the best practices and gaps that may inform California and other states in their future rail service plan development. This paper is grounded in the realization that, while the general outline of FRA requirements is uniform for all states, the actual content and inclusion of these requirements in the myriad state plans varies greatly. For example, California was granted an exception to help update FRA Rail Plan Guidance for its 2018 Rail Plan, other states have complained that FRA guidance and requirements on rail service planning have put state rail agencies in the position of constantly writing plans with little or no time to implement them. Throughout this research, the authors identify all the elements of FRA guidelines as reflected in the CSRP and rail plans of other states. This report also identifies the best features and planning strategies that may inform and improve the state rail planning process going forward, steps that will positively contribute to the public benefit of enhanced rail systems.
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Buathong, Thananon, Anna Dimitrova, Paolo Miguel M. Vicerra, and Montakarn Chimmamee. Years of Good Life: An illustration of a new well-being indicator using data for Thailand. Verlag der Österreichischen Akademie der Wissenschaften, August 2021. http://dx.doi.org/10.1553/populationyearbook2021.dat.1.

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While Thailand has achieved high levels of economic growth in recent decades, poverty at the local level has been increasing. Indicators of human development at the national level often mask the differences in well-being across communities. When responding to the need for sustainable development research, the heterogeneity of a population should be emphasised to ensure that no one is left behind. The Years of Good Life (YoGL) is a well-being indicator that demonstrates the similarities and differences between subpopulations in a given sociocultural context over time. The data used in this analysis were collected from Chiang Rai and Kalasin, which are provinces located in regions of Thailand with high poverty rates. Our main results indicate that the remaining years of good life (free from physical and cognitive limitations, out of poverty and satisfied with life) at age 20 among the sample population were 26 years for women and 28 years for men. The results varied depending on the indicators applied in each dimension of YoGL. Our analysis of the YoGL constituents indicated that cognitive functioning was the dimension that decreased the years of good life the most in the main specification. This study demonstrates the applicability of the YoGL methodology in investigating the wellbeing of subpopulations.
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Raymond, Kara, Laura Palacios, Cheryl McIntyre, and Evan Gwilliam. Status of climate and water resources at Chiricahua National Monument, Coronado National Memorial, and Fort Bowie National Historic Site: Water year 2019. National Park Service, May 2022. http://dx.doi.org/10.36967/nrr-2293370.

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Climate and hydrology are major drivers of ecosystems. They dramatically shape ecosystem structure and function, particularly in arid and semi-arid ecosystems. Understanding changes in climate, groundwater, and water quality and quantity is central to assessing the condition of park biota and key cultural resources. The Sonoran Desert Network collects data on climate, groundwater, and surface water at 11 National Park Service units in southern Arizona and New Mexico. This report provides an integrated look at climate, groundwater, and springs conditions at Chiricahua National Monument (NM), Coronado National Memorial (NMem), and Fort Bowie National Historic Site (NHS) during water year (WY) 2019 (October 2018–September 2019). Overall annual precipitation at Chiricahua NM and Coronado NMem in WY2019 was approximately the same as the normals for 1981–2010. (The weather station at Fort Bowie NHS had missing values on 275 days, so data were not presented for that park.) Fall and winter rains were greater than normal. The monsoon season was generally weaker than normal, but storm events related to Hurricane Lorena led to increased late-season rain in September. Mean monthly maximum temperatures were generally cooler than normal at Chiricahua, whereas mean monthly minimum temperatures were warmer than normal. Temperatures at Coronado were more variable relative to normal. The reconnaissance drought index (RDI) indicated that Chiricahua NM was slightly wetter than normal. (The WY2019 RDI could not be calculated for Coronado NMem due to missing data.) The five-year moving mean of annual precipitation showed both park units were experiencing a minor multi-year precipitation deficit relative to the 39-year average. Mean groundwater levels in WY2019 increased at Fort Bowie NHS, and at two of three wells monitored at Chiricahua NM, compared to WY2018. Levels in the third well at Chiricahua slightly decreased. By contrast, water levels declined in five of six wells at Coronado NMem over the same period, with the sixth well showing a slight increase over WY2018. Over the monitoring record (2007–present), groundwater levels at Chiricahua have been fairly stable, with seasonal variability likely caused by transpiration losses and recharge from runoff events in Bonita Creek. At Fort Bowie’s WSW-2, mean groundwater level was also relatively stable from 2004 to 2019, excluding temporary drops due to routine pumping. At Coronado, four of the six wells demonstrated increases (+0.30 to 11.65 ft) in water level compared to the earliest available measurements. Only WSW-2 and Baumkirchner #3 have shown net declines (-17.31 and -3.80 feet, respectively) at that park. Springs were monitored at nine sites in WY2019 (four sites at Chiricahua NM; three at Coronado NMem, and two at Fort Bowie NHS). Most springs had relatively few indications of anthropogenic or natural disturbance. Anthropogenic disturbance included modifications to flow, such as dams, berms, or spring boxes. Examples of natural disturbance included game trails, scat, or evidence of flooding. Crews observed 0–6 facultative/obligate wetland plant taxa and 0–3 invasive non-native species at each spring. Across the springs, crews observed six non-native plant species: common mullein (Verbascum thapsus), spiny sowthistle (Sonchus asper), common sowthistle (Sonchus oleraceus), Lehmann lovegrass (Eragrostis lehmanniana), rabbitsfoot grass (Polypogon monspeliensis), and red brome (Bromus rubens). Baseline data on water quality and water chemistry were collected at all nine sites. It is likely that that all nine springs had surface water for at least some part of WY2019, though temperature sensors failed at two sites. The seven sites with continuous sensor data had water present for most of the year. Discharge was measured at eight sites and ranged from < 1 L/minute to 16.5 L/minute.
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Fahima, Tzion, and Jorge Dubcovsky. Map-based cloning of the novel stripe rust resistance gene YrG303 and its use to engineer 1B chromosome with multiple beneficial traits. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598147.bard.

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Research problem: Bread wheat (Triticumaestivum) provides approximately 20% of the calories and proteins consumed by humankind. As the world population continues to increase, it is necessary to improve wheat yields, increase grain quality, and minimize the losses produced by biotic and abiotic stresses. Stripe rust, caused by Pucciniastriiformisf. sp. tritici(Pst), is one of the most destructive diseases of wheat. The new pathogen races are more virulent and aggressive than previous ones and have produced large economic losses. A rich source for stripe-rust resistance genes (Yr) was found in wild emmer wheat populations from Israel. Original Project goals: Our long term goal is to identify, map, clone, characterize and deploy in breeding, novel wild emmer Yr genes, and combine them with multiple beneficial traits. The current study was aiming to map and clone YrG303 and Yr15, located on chromosome 1BS and combine them with drought resistance and grain quality genes. Positional cloning of YrG303/Yr15: Fine mapping of these genes revealed that YrG303 is actually allelic to Yr15. Fine genetic mapping using large segregating populations resulted in reduction of the genetic interval spanning Yr15 to less than 0.1 cM. Physical mapping of the YrG303/Yr15 locus was based on the complete chromosome 1BS physical map of wheat constructed by our group. Screening of 1BS BAC library with Yr15 markers revealed a long BAC scaffold covering the target region. The screening of T. dicoccoidesaccession-specific BAC library with Yr15 markers resulted in direct landing on the target site. Sequencing of T. dicoccoidesBAC clones that cover the YrG303/Yr15 locus revealed a single candidate gene (CG) with conserved domains that may indicate a role in disease resistance response. Validation of the CG was carried out using EMS mutagenesis (loss-of- function approach). Sequencing of the CG in susceptible yr15/yrG303 plants revealed three independent mutants that harbour non-functional yr15/yrG303 alleles within the CG conserved domains, and therefore validated its function as a Pstresistance gene. Evaluation of marker-assisted-selection (MAS) for Yr15. Introgressions of Yr15 into cultivated wheat are widely used now. Recently, we have shown that DNA markers linked to Yr15 can be used as efficient tools for introgression of Yr15 into cultivated wheat via MAS. The developed markers were consistent and polymorphic in all 34 tested introgressions and are the most recommended markers for the introgression of Yr15. These markers will facilitate simultaneous selection for multiple Yr genes and help to avoid escapees during the selection process. Engineering of improved chromosome 1BS that harbors multiple beneficial traits. We have implemented the knowledge and genetic resources accumulated in this project for the engineering of 1B "super-chromosome" that harbors multiple beneficial traits. We completed the generation of a chromosome including the rye 1RS distal segment associated with improved drought tolerance with the Yr gene, Yr15, and the strong gluten allele 7Bx-over-expressor (7Bxᴼᴱ). We have completed the introgression of this improved chromosome into our recently released variety Patwin-515HP and our rain fed variety Kern, as well as to our top breeding lines UC1767 and UC1745. Elucidating the mechanism of resistance exhibited by Yr36 (WKS1). The WHEAT KINASE START1 (WKS1) resistance gene (Yr36) confers partial resistance to Pst. We have shown that wheat plants transformed with WKS1 transcript are resistant to Pst. WKS1 is targeted to the chloroplast where it phosphorylates the thylakoid-associatedascorbateperoxidase (tAPX) and reduces its ability to detoxify peroxides. Based on these results, we propose that the phosphorylation of tAPX by WKS1 reduces the ability of the cells to detoxify ROS and contributes to cell death. Distribution and diversity of WKS in wild emmer populations. We have shown that WKS1 is present only in the southern distribution range of wild emmer in the Fertile Crescent. Sequence analysis revealed a high level of WKS1 conservation among wild emmer populations, in contrast to the high level of diversity observed in NB-LRR genes. This phenomenon shed some light on the evolution of genes that confer partial resistance to Pst. Three new WKS1 haplotypes displayed a resistance response, suggesting that they can be useful to improve wheat resistance to Pst. In summary, we have improved our understanding of cereals’ resistance mechanisms to rusts and we have used that knowledge to develop improved wheat varieties.
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Realizing India’s Potential for Transit-Oriented Development and Land Value Capture: A Qualitative and Quantitative Approach. Asian Development Bank, July 2022. http://dx.doi.org/10.22617/spr220271-2.

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This study assesses how the implementation of transit-oriented development (TOD) can help address urban development issues in India. In the context of metro rail systems, TOD has much potential to promote inclusive and sustainable urban mobility. It can also enhance the livability and resilience of cities through better integration of land use policies and the development of the transport network. TOD presents an opportunity to utilize land value capture mechanisms to augment cities’ finances. The study seeks to understand key achievements and challenges of TOD implementation in selected major cities in India. It also explores why synchronized interaction between TOD measures and land use regulations is essential to maximize the socioeconomic benefits of metro rail investments.
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