bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of DNA methyltransferase 3A mRNA expression in Egyptian patients with idiopathic thrombocytopenic purpura
Authors: EL‐SHIEKH E. H. , BESSA S. S. , ABDOU S. M. , EL‐REFAEY W. A.
Published: February 2012

Introduction:  Idiopathic thrombocytopenic purpura (ITP) is an organ‐specific autoimmune hemorrhagic disease characterized by breakdown of self‐tolerance and triggering autoreactive lymphocytes’ response against platelets. The underlying etiology of ITP remains largely unknown. DNA methylation plays an essential role in maintaining T‐cell function, and impaired methylation can lead to inappropriate gene expression and contribute to T‐cell autoreactivity and autoimmunity. The aim of this study was to evaluate the role of DNA methyltransferase 3A gene expression in the pathogenesis of ITP.

Methods:  This study included 60 subjects: 20 healthy volunteers as a control group, 20 patients with acute ITP, and 20 patients with chronic ITP. DNA methyltransferase 3A (DNMT3A) mRNA expression in peripheral blood mononuclear cells was measured by real‐time quantitative polymerase chain reaction. Plasma S‐adenosylhomocysteine (SAH) levels were assayed with reversed‐phase high‐performance liquid chromatography.

Results:  DNMT3A mRNA expression was significantly decreased in patients with ITP as compared with that of the control group. Plasma SAH level was significantly elevated in patients with ITP than in healthy controls. However, no significant difference was found in DNMT3A mRNA expression or plasma SAH level between patients with acute and chronic ITP.

Conclusions:  Aberrant DNA methylation status reflected by decreased mRNA expression of DNMT3A and increased plasma SAH level may play an important role in the pathogenesis of ITP, although the precise underlying mechanisms still await further investigations, and extensive work in this field is clearly needed to provide novel therapeutic targets for ITP.
Social‐Psychological Theories and Adolescent Health Risk Behavior
Authors: Gibbons Frederick X. , Kingsbury John H. , Gerrard Meg
Published: February 2012

This paper reviews several psychosocial theories that have been applied to the study of adolescent health behavior. Some of these theories have existed for several decades and, though not originally intended for this purpose, have proven quite useful in predicting and explaining many different types of health‐relevant behaviors. During the last 10–15 years, however, there has been a significant increase in the application of social psychological theories to the examination of what is increasingly being seen as a social‐psychological phenomenon: health risk behavior among adolescents. This interest has been prompted, in part, by an appreciation of the value of dual‐processing principles in explaining these behaviors, and, in particular, a recognition that much adolescent health risk behavior: a) is not always planful or premeditated, and b) involves both heuristic and analytic processing. The paper includes discussion of how dual‐processing principles and social‐psychological theories can inform intervention efforts.
Selection, Optimization, and Compensation in the Domain of Emotion Regulation: Applications to Adolescence, Older Age, and Major Depressive Disorder
Authors: Opitz Philipp C. , Gross James J. , Urry Heather L.
Published: February 2012

Emotions often are well calibrated to the challenges and opportunities we face. When they are not, we may try to regulate our emotions. Interestingly, there seems to be considerable variation both in the strategies people use to regulate emotions and in the success of these emotion regulation efforts. The Selection, Optimization, and Compensation with Emotion Regulation framework suggests that variation in the resources required for particular emotion regulation strategies may be a crucial determinant of emotion regulation use and success within individuals across situations, between individuals, and between groups of individuals. In this review, we consider the ways in which two resources for emotion regulation (working memory and social support) might differ among three groups, namely adolescents, older adults, and adults with major depressive disorder. We link these between‐group differences in resources to differences in emotion regulation and make suggestions for future research.
Cultural Variations in Motivation for Cognitive Consistency: Influences of Self‐Systems on Cognitive Dissonance
Authors: Hoshino‐Browne Etsuko
Published: February 2012

Are people always motivated to strive for cognitive consistency? Does culture influence a person’s motivation to maintain cognitive consistency between attitudes and actions or between preferences and choices? When and how do people in different cultures experience cognitive dissonance, engage in justification of their behavior, and use self‐affirmation? When and how are people with different models of agency motivated to maintain a preference‐choice consistency? In this paper, culturally variable self‐schemata and models of agency, independent self and agency dominant in North American culture and interdependent self and agency prevalent in Asian culture, are considered as the source of cultural variations in cognitive consistency. These culturally divergent self‐systems create variance in situations in which North Americans and Asians are motivated to maintain cognitive consistency. In this paper, related cross‐cultural research is reviewed. Some future research agenda are also discussed.
Motivated Strategies for Judgment: How Preferences for Particular Judgment Processes can Affect Judgment Outcomes
Authors: Molden Daniel C.
Published: February 2012

Beyond motivations to achieve particular outcomes, people also have motivations to use particular strategies while pursuing these outcomes. This article integrates research on the latter strategic preferences and discusses the place of such research in the broader investigation of motivated thinking. A review of studies examining the strategic preferences stemming from both motivations for promotion versus prevention (Higgins, 1997) and motivations for locomotion versus assessment (Higgins, Kruglanski, & Pierro, 2003) illustrates that these preferences have unique effects on basic processes of judgment, including the evaluation of alternative hypotheses or counterfactuals, the prioritization of fast versus accurate information processing, and the recall and activation of knowledge from memory. Moreover, this review also demonstrates important interactions between strategic preferences and outcome preferences. Strategic preferences thus appear to make distinct and important contributions to understanding how motivation influences judgment and should feature prominently in general analyses of motivated thinking.
Working With Families Living With Autism: Potential Contributions of Marriage and Family Therapists
Authors: Neely Jason , Amatea Ellen S. , Echevarria‐Doan Silvia , Tannen Tina
Published: February 2012

This article introduces marriage and family therapists (MFT) to some of the common issues faced by families that have a child with autism spectrum disorder (ASD). First, autism is defined and common myths surrounding it are discussed. Next, relational challenges are presented that families report experiencing during early childhood through the elementary school years, adolescence and the transition into adulthood, and the later years of the family life cycle. Real‐life stories are included to illustrate the potential contributions that MFTs can make to families that have a child with ASD.
When Should We Use Nitrates in Congestive Heart Failure?
Authors: Vizzardi Enrico , Bonadei Ivano , Rovetta Riccardo , D'Aloia Antonio , Quinzani Filippo , Curnis Antonio , Dei Cas Livio
Published: February 2012

Organic nitrates remain among the oldest and most commonly employed drugs in cardiology. Although, in most cases, their use in acute and chronic heart failure is based on clinical practice, only a few clinical trials have been conducted to evaluate their use in acute and chronic heart failure, most of which compare them with other drugs to evaluate differing endpoints. The purpose of this review is to examine the various trials that have evaluated the use of nitrates in acute and chronic heart failure.
Rotala tulunadensis sp. nov. (Lythraceae) from Kerala, India
Authors: Prasad K. Subrahmanya , Biju P. , Raveendran K. , Bhat K. Gopalakrishna
Published: February 2012

A new aquatic species of the family Lythraceae (Rotala tulunadensis) collected from the lateritic plateau at Permude, Kerala, India is described and illustrated. It is closely allied to R. pterocalyx A. Raynal, but differs in having larger leaves, calyx tube not stretching laterally to include the capsule, calyx without interjected folds in fruit and larger petals.
The Lighter Side of Early Weimar Cinema's Dark Canon: Paul Leni'sDas Wachsfigurenkabinett(1924)
Authors: Westerdale Joel
Published: February 2012

Scholars frequently present Paul Leni'sDas Wachsfigurenkabinett(1924) as a proto‐horror exemplar of early Weimar cinema's dark canon, aligning it neatly with films likeDas Cabinet des Dr. Caligari(1920) andNosferatu(1922), and actively downplaying its substantial comedic element. In this article, I argue that the scholarly reception of Leni's film reveals the biases that color early Weimar cinema as a whole. The dominance of particular films—and only select aspects of Leni's film—arose from an historically and culturally specific confluence of technological and economic factors that together created an environment in which the darker films of early Weimar cinema could flourish, while lighter popular releases were lost to the historical imagination.Das Wachsfigurenkabinettoffers a clearer view into Weimar film culture not only because it offers the kind of dark, mysterious film considered characteristic of early Weimar cinema, but because it also embraces generic possibilities left unexplored by its darker brethren, exemplifying in itself the era's rich generic diversity that until recently has been suppressed.
Facts of Migration, Demands on Identity: Christian Petzold's Yella and Jerichow in Comparison1
Authors: Miller Matthew D.
Published: February 2012

This article explores Christian Petzold's cinematic contribution to processes of identity‐formation in a unified Germany by comparing the treatment of migration in his films Yella and Jerichow. In these two films, Petzold suggestively crosses the East‐West divide of the nation with ethnic, gender, and class difference to expose lingering fault‐lines in German society. By focusing on Petzold's correlation of East‐West German with German‐Turkish tensions under the rubric of an expanded conception of ethnicity, the political content of Petzold's works is described in terms of their negative finding: that it is as impossible to be an East‐West German as it is to be a German‐Turk in the new nation. In a redress of the limits placed on hybrid forms of identity, Petzold subtly confronts his spectators with their own complicity in the mechanisms of identitarian restriction. This constitutes the political impact of his films.
Comparison of epidermal growth factor receptor mutation analysis results between surgically resected primary lung cancer and metastatic lymph nodes obtained by endobronchial ultrasound‐guided transbronchial needle aspiration
Authors: Okada Hironobu , Anayama Takashi , Kume Motohiko , Hirohashi Kentaro , Miyazaki Ryouhei , Matsumoto Manabu , Orihashi Kazumasa
Published: February 2012

Background:  Lung cancers with mutations in the epidermal growth factor receptor (EGFR) gene respond well to treatment with EGFR inhibitors. Endobronchial ultrasound‐guided transbronchial needle aspiration (EBUS‐TBNA) is considered a useful modality to obtain samples from the mediastinal and hilar lymph nodes. However, the EGFR gene status of EBUS‐TBNA samples may not always match that of primary tumors.

Methods:  In 14 node‐positive patients diagnosed by EBUS‐TBNA, EGFR mutation analysis results were compared between EBUS‐TBNA samples and surgically removed primary tumors. EGFR mutation was screened with peptide nucleic acid‐locked nucleic acid polymerase chain reaction (PNA‐LNA PCR) clamp followed by direct sequence analysis. For one controversial case, gene mutation analyses were performed for the multiple micro‐fractions of a metastatic lymph node, which exhibited the heterogeneous immunohistochemical features.

Results:  EBUS‐TBNA diagnosed one case of exon 21 point mutations, one case of exon 19 deletion, and 12 cases of wild‐type EGFR. Results were consistent with those of surgically removed primary tumors in 13 of 14 cases. One case of wild‐type EGFR diagnosed by EBUS‐TBNA exhibited exon 21 point mutation in the surgically removed primary tumor. The metastatic lymph node targeted by EBUS‐TBNA mostly consisted of cancer cells with wild‐type EGFR; however, a minor component positive for thyroid transcription factor‐1 (TTF‐1) and surfactant‐associated protein A (PE‐10) exhibited EGFR mutation.

Conclusion:  The combination of EBUS‐TBNA and PNA‐LNA clamp is useful for EGFR mutation analysis. However, EGFR mutation status in EBUS‐TBNA samples may not be consistent with that of the primary tumor when the tumor contains few EGFR mutations.
Using Building Information Modeling for Green Interior Simulations and Analyses
Authors: Lee Young S.
Published: February 2012

There is a growing trend of green building design that relies on technologies and computer simulations based on building information modeling (BIM) during the design process. Green building project teams are increasingly adopting BIM due to its capabilities of analyzing and simulating various design scenarios to make informed decisions to achieve green objectives. However, there is currently a gap in the technological approach to achieving green design in interior design. In order for interior designers to make informed decisions for effective green interior designs, interior designers need to understand the critical functions of BIM–based simulations and analyses in achieving green interior environments. This exploratory paper intended to discuss how BIM can be used for green simulations during the design process and to provide a framework for incorporating BIM–based green simulations and analyses to interior design projects based on four categories found from literature review. Four types of methods included are visual analysis, prescriptive analysis, web–based external simulation, and external simulation and visualization. Four types of methods were examined with case studies performed in an interior design course over 3 years. The course utilized BIM and BIM–based external building performance simulation and analysis tools to achieve green interior environments. Lastly, the paper discusses interior design pedagogical issues with using BIM–based simulations and analyses including student learning experiences as well as the challenges and benefits of incorporating green simulations to interior design projects.
Asymmetric Price Distribution and Bid–Ask Quotes in the Stock Options Market*
Authors: Chan Kalok , Peter Chung Y.
Published: February 2012

We present a model of the bid and ask quotes in the equity option market when option payoffs are asymmetrically distributed due to the limited liability of the option. We then provide empirical evidence for the actively traded Chicago Board Options Exchange stock options, which is consistent with the implications of our model. First, the bid and ask quotes are asymmetric around the option value, with the value being closer to the bid quote than to the ask. Second, the degree of the asymmetry increases as the moneyness of the option decreases. Finally, the ask quote of an option changes more than its bid quote. An important implication of the paper is that the bid–ask midpoint is not an unbiased estimator of the option value, especially for out‐of‐the‐money options.
Corporate Governance and Diversification*
Authors: Gleason Kimberly C. , Kim Inho , Kim Yong H. , Kim Young Sang
Published: February 2012

Using 1640 observations of completed acquisitions from 1996 to 2003, we investigate the relation between corporate governance and returns to bidders and targets. We find that the cumulative abnormal returns for acquirers are significantly negative upon announcement of acquisitions for the full sample and for the related and diversifying subsamples. However, we find that diversifying acquisitions, when conducted by firms with a higher percentage of outsiders on the board, improve returns. Furthermore, we separately examine high‐technology and non‐high‐technology firms to test the relation between board characteristics and announcement returns in different information asymmetry environments. We also find that diversifying acquirers with independent boards perform better than those with insider‐dominated boards and the results are especially pronounced for high‐technology firms. Taken together, the results suggest that firms with better incentive alignment will be more likely to be perceived by the market as stronger performers in acquisitions. In sum, we find that corporate governance plays an important role in determining wealth creation for our sample of acquiring firms.
Empirical Comparison of Alternative Implied Volatility Measures of the Forecasting Performance of Future Volatility*
Authors: Rhee Dong Woo , Byun Suk Joon , Kim Sol
Published: February 2012

Implied volatility from the Black and Scholes (Journal of Political Economy 81, 1973, p. 637) model has been empirically analyzed for the forecasting performance of future volatility and is well known to be biased. Based on the belief that implied volatility from option prices can best estimate future volatility, this study identifies the best way to derive implied volatility to overcome the forecast bias associated with the Black–Scholes model. For this, the following three models are considered: Heston’s model, which best addresses the problems associated with the Black–Scholes model for pricing and hedging options; Britten‐Jones and Neuberger’s model‐free implied volatility (MFIV), which eliminates the model‐oriented bias; and VKOSPI, the Korean version of the Chicago Board Options Exchange Market Volatility Index. This study conducts a comparative analysis of implied volatilities from the Black–Scholes model, Heston’s model, the MFIV, and VKOSPI for their abilities to forecast future volatility. The results of the empirical analysis of the KOSPI 200 options market indicate that Heston’s model can eliminate most of the bias associated with the Black–Scholes model, whereas the MFIV and VKOSPI do not show any improvement in terms of forecasting performance.
Hydrodynamic Lubrication of Conformal Contacting Surfaces With Parabolic Grooves
Authors: Fu Yonghong , Ji Jinghu , Bi Qinsheng
Published: February 2012

The effect of surface texturing in the form of parabolic grooves on the hydrodynamic lubrication properties is investigated in this paper. Numerical simulation of the pressure distribution of lubricant between a textured slider and a smooth, moving slider has been performed. The evaluation criterion of hydrodynamic effect of dimensionless average pressure is calculated and presented with the variation of minimum film thickness, groove width, groove depth, spacing and orientation angle. Optimum values of geometrical parameters such as the dimensionless groove depth, spacing and orientation angle are obtained which correspond to maximum average pressure. It is also noted that the average pressure increases monotonically with increasing groove width. The results show that the hydrodynamic effect can be improved by employing optimized surface texturing design.
The Influence of Construction Features of a Thin-Layer Sensor on Pressure Distributions Recorded in an Elastohydrodynamic Contact
Authors: Wilczek Adam
Published: February 2012

This paper presents the experimental study of the construction features of a thin-layer sensor on the accuracy of pressure measurements in an EHD contact. Two common types of transducer shapes and isolating layers of the sensor, made of SiO are considered. The measurements were carried out on a two-disc machine, with the use of two mating lubricated steel cylindrical disks. On the outside surface of one of the discs, a pressure sensor was deposited with two transducers of different shapes, symmetric and asymmetric, located close to each other. The pressure transducer has an active part in the form of a layer contraction, and two wider parts of the layer serves as electrical leads (connections). In the symmetric transducer, the active part is located in the middle of the connections width and in the asymmetric transducer the active part is located along the edge of connections. In case of no current supply for the measurement bridge, the measurement signals from the sensor were observed. The occurrence of these signals indicated piezoelectric properties of the insulation layers of the sensor. The investigations showed that the shape of the transducer has a significant influence on the accuracy of pressure measurements. In the case of the asymmetric transducer, the measurement signal distortions caused by the piezoelectric effects and changes in the electric capacitance of the sensor were much larger than in the case of the symmetric transducer. Measurement signal courses coming from the asymmetric transducer were significantly influenced by the transition velocity of the sensor trough the contact, by the value of the current supplying the measurement bridge and by the rotation direction of the disc with the sensor.
Effect of Nitro-Carburizing Treatment on Wear Mechanism and Friction of Steel/WC-Co Sliding Couple
Authors: Fazlalipour F. , Shakib N. , Shokuhfar A. , Niki Nushari M.
Published: February 2012

In this work, tribological behavior and material degradation mechanisms of Nitro-carburized AISI H11 hot work tool steel were investigated during sliding against cemented tungsten carbide (WC/Co). The diffusion layer with an iron-nitrocarbide (Fe (N,C)) compound layer was developed on pre-hardened tool steel by a low temperature Ferritic Nitro-Carburizing (FNC) process in a gas medium. The X-ray diffraction analysis, microhardness testing, and optical microscopy were employed to indicate the properties of the compound and diffusion layers. Friction and wear tests were carried out by using the pin-on-disk technique under severe wear condition, and a wear map was provided for different load and sliding distance. Results of SEM secondary and backscatter imaging of wear scar together with EDS analysis of wear debris showed insignificant two-body abrasion wear system and oxide tribo-film on the nitro-carburized samples. In the case of the hardened sample, intensive plastic deformation on the surface, adhesion, and disk materials transfer developed three-body abrasive wear and a degradation mechanism. It was concluded that a lower material degradation rate and the friction coefficient of nitro-carburized steel in comparison with the hardened sample can be related to the formation of a protective oxide layer and a gradual increase in hardness from surface to substrate.
Experimental Research on Drag Torque for Single-plate Wet Clutch
Authors: Jibin Hu , Zengxiong Peng , Chao Wei
Published: February 2012

The relative motion between the friction and separate plates in a disengaged wet clutch causes viscous drag torque when the lubrication fluid flows through the clearance. Reduction of the drag torque is one of the important potentials for the improvement of transmission efficiency. The objective of this study is to set up an experimental rig to measure drag torque for a single-plate wet clutch. Visualization of the flow pattern in the clearance through transparent quartz was presented. Design factors and lubrication conditions were tested to evaluate the effects on drag torque. A comparison between the nongrooved plate and grooved plate was made. Plates made up of different materials were also tested to reveal the effects caused by the contact angle. Drag torque increases linearly at low rotating speeds and gradually decreases at high rotating speeds. It is confirmed that fluid completely covers the plate surface at a low rotating speed and air mixes with the fluid at a high rotating speed. A low feeding flow rate is useful to reduce drag torque. The reduction of the drag torque benefits from radial and deep grooves compared to a flat plate. A small contact angle near the stationary plate plays an important role in maintaining the oil film, however, it has little effect on the drag torque at the rotating side because the hydrodynamic force becomes dominant compared to the surface tension force. The test results help to build an accurate mathematical model based on two-phase flow lubrication.
Passenger Track Curve Design Criteria: Comfort Criteria, Equivalent Comfort Criteria, and Application
Authors: Hasan Nazmul
Published: February 2012

It is generally recognized by FRA, AREMA, Amtrak, OSHA, and many other applicable authorities that the maximum acceptable rate of radial acceleration for passengers comfort is 0.1g, where ‘g’ is 9.81 m/s/s [1]. Jerk is limited to 0.03g/s [1]. Roll is limited to 1 deg/sec. In this paper all values computed with the aforesaid standard values are referred to as the maximum desirable values as these may be exceeded if needed. Currently there is no procedure in the literature to compute the maximum desirable values. From these comfort criteria the formulae for superelevation run off, rate of change of curvature, radius, and spiral angle etc. are derived. Applications of these formulae and further potential applications thereof are presented. This study is intended for conventional non-tilting train. The equilibrium (Eq), actual (Ea), and unbalance superelevation (Eu) run-off are calculated to be 45 mm/sec, 26 mm/sec and 19 mm/sec respectively. From the run-off rates, the maximum desirable actual and unbalance superlevation comes out to be 87 mm and 63 mm respectively. The desirable ratio between unbalance and actual super-elevation comes to be 0.72. This helps in proportioning equilibrium superelevation to ensure comfort. Equations of spiral length are derived by proportioning 3.33 sec’s ride with the maximum desirable values of superelevation and these equations are found to be exactly the same as those derived another way in the paper no. JRC 2010-36050.
Rehabilitation Techniques to Improve Long-Term Performances of Highway-Railway At-Grade Crossings
Authors: Rose Jerry G.
Published: February 2012

The primary purpose of the highway-railway at-grade crossing is to provide a smooth surface for the safe passage of rubber-tired vehicles across the railroad. The crossing support and surface in the jointly used area represent a significantly expensive unit cost of the highway and railway line. The ideal highway crossing will maintain a smooth surface and stable trackbed for a long period of time. This will reduce costly, frequent disruptions to highway and railway traffic (to adjust the track or renew the surface due to rideability concerns), while concurrently providing improved operating performance and long life. Technology is available for rapidly renewing highway crossings within one day using a panel system with specifically designed layered support and premium materials. The procedure involves complete removal of the old crossing panel and trackbed materials — and replacing them with an asphalt underlayment layer, a pre-compacted ballast layer, a new track panel, and a new crossing surface. A cooperative effort between the local highway agency and the railway company will reduce costs, improve the quality of the finished product, and reduce outage of the highway and railroad. A major objective is to minimize disruption to both highway and railway traffic during the renewal process in addition to extending the life of the crossing. Suggested procedures, based on experiences for several installations, are presented. Typical schedules are for the railroad to be to be out-of-service for a maximum of four hours and for the highway to be closed only eight to twelve hours. Results are presented for crossings instrumented with pressure cells to document Pressure levels within the layered portion of the crossing structure. In addition, long-term Settlement measurements and assessments for several crossings are documented. The measurements indicate significantly reduced long-term settlements of crossings incorporating the rapid-renewal, layered system, while maintaining acceptable smoothness levels. These long-term performance evaluations indicate this practice ensures long-life, economical, smooth crossings for improved safety and operating performances for both highway agencies and railway companies.
Structural Design of Railway Trackbeds: Relative Effects of Various Factors
Authors: Rose J. G. , Trella M. C. , Agarwal N. K.
Published: February 2012

Layer-elastic, finite-element computer programs are available for performance-based structural design and analysis of railway trackbeds. This paper utilizes the KENTRACK design program. It is possible to consider the fatigue lives of the various layers relative to the imposed wheel loads, tonnages, environmental conditions and other factors. The service lives of the individual components of the trackbed are predicted by damage analysis for various combinations of traffic loadings, accumulated tonnages, subgrade support, and component layer properties and thicknesses. The results are presented graphically. The latest version, KENTRACK 3.0, is utilized. It is coded in C#.NET a popular computer language for achieving accuracy and efficiency. The graphical user interface in the KENTRACK 3.0 provides a technique to analyze trackbeds as structures. It is possible with KENTRACK 3.0 to select individual trackbed layers and associated thicknesses to satisfy roadbed and trackbed performance requirements. In addition, it is possible to performance-rank different track sectional designs based on the relative importance of the particular track section and track type. The types of roadbed and trackbed configurations are selected to meet each of the various performance ranks.
Quantitative Nondestructive Evaluation of Railroad Tank Cars
Authors: Garcia Gregory , Rummel Ward D. , Gonzalez Francisco , Strouse Lawrence H.
Published: February 2012

A rulemaking issued by the Department of Transportation (DOT) revises Hazardous Materials Regulations (HMR) to replace the hydrostatic pressure test with appropriate nondestructive evaluation (NDE) methods. The rule change is contained in Federal Register 49 Code of Federal Regulations (CFR) Part 180.509, “Requirements for inspection and test of specification tank cars,” paragraph (e) “Structural integrity inspection tests” [1]. The CFR authorizes liquid penetrant (PT), magnetic particle (MT), radiography (RT), ultrasonic (UT), and optically aided visual testing (VT) as allowable NDE methods for structural integrity inspections and tests. Other NDE methods may be allowed under special exemption issued by the Federal Railroad Administration (FRA) Office of Safety. Also included under the requirements of 49 CFR Part 179.7 is the need to qualify not only NDE personnel, but the procedures used to perform NDE reliably. In order to be effective, federal regulations require that the NDE methods have a proven sensitivity and reliability for finding the type and size of flaws likely to cause a tank car failure. In the early 1970s, an internationally accepted quantitative approach that assesses the probability of detection (POD) was developed for the National Aeronautics and Space Association (NASA) and was published in NASA CR-2369, February 1974 [2]. Transportation Technology Center, Inc. (TTCI), under contract with the FRA, and along with industry participation, uses the NASA approach to determine the POD for various NDE methods used in the inspection of railroad tank car circumferential butt welds (girth seam welds), fillet welds, and leak test samples. The emergence of a damage tolerance approach to determine inspection intervals for an engineered structure — in this case a railroad tank car — requires the quantification of the detectable flaw size for the NDE methods used during inspection. Damage tolerance techniques have initiated an evolution in NDE understanding, methods, and requirements. National Transportation Safety Board safety recommendations R-92-21 through R-92-24 address the suggested process of performing reliable inspection of railroad tank cars based on a damage tolerance approach [3]. NDE quantification using the POD approach is a key measure of NDE effectiveness and is integral to damage tolerance requirements. TTCI, working with the FRA, Railroad Tank Car Industry and D&W Enterprises (A NDE consulting company providing expertise in the area of NDE POD), has developed baseline POD curves for the allowed NDE methods. Initial evaluations were performed on the inspection of tank car circumferential butt welds. Subsequent efforts focused on butt welds, longitudinal fillet welds and leak test samples requiring inspection under the CFR. This paper reports quantitative results obtained during this research effort that address system safety and risk analysis during handling and transportation of railroad tank cars carrying hazardous materials.
High Speed Rail: Track Construction Considerations
Authors: Peterson Blaine O.
Published: February 2012

This paper discusses general High Speed Rail (HSR) track geometry, construction and maintenance practices and tolerances. The discussion will reference several key international projects and highlight different construction methods and the track geometry assessments used to establish and ensure serviceability of a typical HSR system. Historically, established tighter tolerances of “Express” HSR (i.e. operating speeds greater than 240 km/h or 150 mph) systems have favored the use of slab track systems over ballasted track systems. Slab track systems offer greater inherent stability while ballasted track systems generally require more frequent track geometry assessments and anomaly-correcting surfacing operations. The decisions related to which system to use for a given application involve numerous considerations discussed only briefly in this paper. In many cases, the optimal solution may include both track forms. Rolling stock considerations and their influence on track infrastructure design are considered beyond the scope of this paper. This paper will focus predominantly on two slab track systems widely used in international HSR projects: the Japanese J-slab track system; and the German Rheda slab track system. The French track system will be referenced as the typical ballasted track HSR design. The practices discussed in this paper generally apply to systems which are either primarily or exclusively passenger rail systems. In the U.S., these types of systems will necessarily exclude the systems the Federal Railway Administration (FRA) refers to as “Emerging” or “Regional” HSR systems which include passenger train traffic to share trackage on, what are otherwise considered, primarily freight lines.
Broken Rail Prediction and Detection Using Wavelets and Artificial Neural Networks
Authors: Hopkins Brad M. , Taheri Saied
Published: February 2012

Current track health monitoring requires time consuming use of railway monitoring vehicles. This paper presents a rail defect detection and classification algorithm that could potentially be used with bogie side frame vertical acceleration data from a data acquisition system located onboard a train car during daily operation. The algorithm uses wavelets to process the vertical acceleration data and detect irregularities in the signal. Wavelets have proven themselves to be useful in event detection and other applications where localization is needed in both the time and frequency domains. Traditional signal processing methods may use the Fourier transform which is limited to localization only in the frequency domain. Wavelets provide a solution for recognizing rail defects and determining their location. The wavelet-processed data is fed into an artificial neural network for defect classification. Neural networks can be a powerful tool in pattern recognition and classification because of their ability to be taught. The network in this algorithm has been trained to recognize impending breaks and breaks in a rail from the original vertical acceleration signal and the first four scales of the wavelet transformed signal. This paper presents an offline analysis of a set of collected data using the proposed defect detection and classification algorithm.
Designing Automatic Train Regulation With Energy Saving by Using Dual Heuristic Programming
Authors: Sheu Jih-Wen , Lin Wei-Song
Published: February 2012

Issues regarding environment sustainability and energy saving have been receiving concerns in worldwide railway society though railway system have been recognized as a transport mode of less environmental impact. Energy saving via train operation and regulation would be a cost-effective way and becomes a requirement while performing train operation and regulation. Automatic Train Regulation (ATR) plays an important role of maintaining the service quality of metro. However, designing ATR is a large scale optimization problem with high nonlinearity, heavy constraints, and stochastic characteristics. Considering issues regarding energy saving in the ATR design further complicates the problem. A metro traffic model which accounts for energy consumption is investigated in this paper. Thereby, Dual Heuristic dynamic Programming (DHP) technique is employed to design an optimal ATR with energy saving for metro line. Simulation tests of the ATR design were carried out with field data. Results show that better traffic regulation with less energy consumption is attainable through coasting and dwell time control.
Shared Corridors, Strange Bedfellows: Understanding the Interface Between Freight and Passenger Rail
Authors: Iacobacci Mario
Published: February 2012

This paper aims to clarify issues regarding shared rail corridors from a public policy perspective. It presents an overview of the relationships between the main stakeholders operating trains on North America’s rail networks: the railway companies that own the rail infrastructure and use it to provide freight services to shippers, and the passenger service operators—which are primarily public agencies that pay railway companies for track access and other services required to operate commuter and intercity passenger trains. The issues at stake are of concern to the policy and business community alike, because congestion on railway lines affects commuter rail, intercity passenger trains, and long-distance freight trains. In addition to the obvious economic costs of delays or less-reliable transit times in passenger and freight rail, respectively, adverse environmental and social impacts (e.g., higher accident rates on roadways) arise if either freight or passenger traffic shifts from rail to roadways. An earlier version of this paper was published by the Conference Board of Canada in September 2010.
A Data Structure Model Supporting Railway Distributed System Integration
Authors: Wang Hanning , Xu Weixiang , Jia Chaolong
Published: February 2012

Railway distributed system integration needs to realize information exchange, resources sharing and coordination process across fields, departments and application systems. And railway data integration is essential to implement this integration. In order to resolve the problem of heterogeneity of data models among data sources of different railway operation systems, this paper presents a novel integration data model of spatial structure, a XML-oriented 3-dimension common data model. The proposed model accommodates both the flexibility of level relationship and syntax expression in data integration. In this model, a spatial data pattern is used to describe and express the characteristic relationship of data items among all types of data. Based on the data model with rooted directed graph and the organization of level as well as the flexibility of the expression, the model can represent the mapping between different data models, including relationship model and object-oriented model. A consistent concept and algebraic description of the data set is given to function as the metadata in data integration, so that the algebraic manipulation of data integration is standardized to support the data integration of distributed system.
Improving Crashworthiness of Railroad Rolling Stocks With New Generation Shock Energy Absorbers
Authors: Parida Basant K. , Xin Xudong , Zaouk Abdullatif K. , Punwani S. K.
Published: February 2012

This paper describes the results of quasi-static and dynamic tests of a new shock energy absorber (SEA) capable of high energy absorption while limiting peak dynamic force magnitude in the event of an impact or collision. The SEA utilizes the unique reversible phase transition behavior of Ultra High Molecular Weight Poly-Ethylene (UHMWPE) material under pressure. A prototype drop hammer test confirmed the device’s high energy absorption as well as high damping capabilities at a relatively high deformation rate. The results of the test were used to calibrate a finite element (FE) model that enabled scalability of the SEA for practical applications. Preliminary design and FE simulations were made under a Federal Railroad Administration (FRA) sponsored program toward using a set of SEA as a part of a crash energy management (CEM) system to improve locomotive crashworthiness. The main objective of the program was to prevent locomotive override in the event of an inline collision with a hopper car consist at a closing speed of 30 mph. The FE model, without CEM, was validated to a previously performed full-scale locomotive crashworthiness test at Transportation Technology Center, Inc. (TTCI), Pueblo. The FE simulation results with added CEM system showed successful prevention of locomotive override up to 32.1 mph collision speed. Further scope of using suitably tailored SEA units as buffers to the ends of passenger coaches and tank cars with the objective of enhancing their crashworthiness is discussed.
Application of Nadal Limit for the Prediction of Wheel Climb Derailment
Authors: Marquis Brian , Greif Robert
Published: February 2012

Application of the Nadal Limit to the prediction of wheel climb derailment is presented along with the effect of pertinent geometric and material parameters. Conditions which contribute to this climb include wheelset angle of attack, contact angle, friction and saturation surface properties, and lateral and vertical wheel loads. The Nadal limit is accurate for high angle of attack conditions, as the wheelset rolls forward in quasi-static steady motion leading to a flange climbing scenario. A detailed study is made of the effect of flange contact forces Ftan and N, the tangential friction force due to creep and the normal force, respectively. Both of these forces vary as a function of lateral load L. It is shown that until a critical value of L/V is reached, climb does not occur with increasing L since Ftan is saturated and the flange contact point slides down the rail. However, for a certain critical value of L/V (i.e. the Nadal limit) Ftan is about to drop below its saturated value and flange climb (rolling without sliding) up the rail occurs. Additionally, an alternative explanation of climb is given based on a comparison of force resultants in track and contact coordinates. The effects of longitudinal creep force Flong and angle of attack are also investigated. Using a saturated creep resultant based on both (Ftan, Flong) produces a climb prediction L/V larger (less conservative) than the Nadal limit. Additionally, for smaller angle of attack the standard Nadal assumption of Ftan = μN may lead to an overly conservative prediction for the onset of wheel climb. Finally, a useful analogy for investigating conditions for sliding and/or rolling of a wheelset is given from a study of a disk in rigid body mechanics.
Design and Analysis of 220 MHz RF Communications for Interoperable Positive Train Control System
Authors: Himsoon T. Kee , Siriwongpairat W. Pam
Published: February 2012

The interoperable positive train control (PTC) system uses radio frequency (RF) in the 220 MHz band for wireless communications. Robust and reliable 220 MHz RF communication is critical to the success of the interoperable PTC system. To ensure proper operation of the interoperable PTC system, it is thus crucial to properly engineer and evaluate RF performance of communications from wayside devices and base stations to trains operating along PTC controlled track. This paper presents a design of wireless communications over the 220 MHz band for the interoperable PTC system. Performance of the designed 220 MHz PTC communications is analyzed and theoretical predictions are provided. The paper also presents a simulation system architecture for analyzing the performance of PTC communications over the 220 MHz band. The simulation system test bed integrates a message generator, RF channel simulator, and PTC software-defined radio prototypes configured as a base, locomotive, or wayside radio. Extensive simulations were conducted to determine RF performance of PTC radio communications in various scenarios including flat terrain and city environments. Simulation results are given and compared to the theoretical predictions.
Potential Scenarios of Concern for High Speed Rail Operations
Authors: Carolan Michael , Sullivan Laura
Published: February 2012

Currently, multiple operating authorities are proposing the introduction of high-speed rail service in the United States. While high-speed rail service shares a number of basic principles with conventional-speed rail service, the operational requirements on a high-speed rail system are typically more demanding than those for conventional-speed operations. The operating environment will require specialized maintenance and inspection procedures, enhanced protection or grade-separation of highway-rail crossings, effective separation of other rail traffic, and detection of potential hazards along the track to help ensure the safety of the system. With the required implementation of positive train control (PTC) by passenger-carrying rail operators, the frequency and/or severity of several types of railroad accidents can be decreased. While all of these measures will contribute to the overall system safety, incidents that pose a threat to passenger and crew safety may still occur that cannot be prevented through the design of the operating environment alone. It is important to consider these types of incidents when selecting the rail vehicles for use in a particular operation, and include appropriate crashworthiness and occupant protection measures. This paper presents a series of example scenarios of some of the potential hazards that may affect the safe operation of high-speed passenger trains in the United States. These situations are drawn from actual accidents that have occurred in the U.S. and abroad. The scenarios provide a starting point for discussing system safety features, which includes vehicle crashworthiness and occupant protection features. As an operating environment may be designed to limit the likelihood of certain types of incidents from occurring, three different hypothetical high-speed operating environments are discussed in this paper. While the number of potential scenarios varies with each operating environment, in all environments it is important to consider the need for a train’s crashworthiness features to mitigate the consequences of potential incidents.