bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic Force and Ultrasonic Force Microscopic Surface Characterization of Laser Treated Head Sliders
Authors: Druffner Carl , Schumaker Edward J. , Shen Liming , Sathish Shamachary , Raikar Ganesh N. , Brar Amarjit S. 
Published: November 2021

Abstract
The surface of laser treated hard disc drive head sliders has been imaged using the Atomic Force Microscope and Ultrasonic Force Microscope. The contrast of the surface topography image from the Atomic Force Microscope is compared with the elasticity image generated by the Ultrasonic Force Microscope on the same sample region. Images of microcracking in the laser treated regions are presented. The possible reasons for the development of microcracking and the enhanced contrast of the Ultrasonic Force Microscope imaging of these microcracks are discussed.
On CFD-Based Performance Calculations of Centrifugal Compressor Stages: Part 1
Authors: Biba Yuri I. , Hill D. Lee 
Published: November 2021

Abstract
Turbocompressor manufacturers as well as customers have a constant need for improved aerodynamic component analysis for production and development environments. These predictive tools have historically been grounded with experimental data. Both hardware and tests costs, however, continue to spiral upward, and the difficulties of obtaining reliable data remain unchanged. This has forced the turbocompressor manufactures to use Computational Fluid Dynamics (CFD) as an alternative approach for conducting stage parametric studies. In order for such an approach to be successful, a clear understanding of the relationship between the traditional performance parameters and the numerical solution has to be achieved. Ultimately, an industry standard similar to the test codes should be established. The focus of this work is to contribute into laying the foundation for such an effort. Based on energy conservation equations the relationships between CFD-based loss calculations and efficiencies are developed and discussed. Example of CFD-based performance prediction and flow field analysis of low flow compressor stage is then presented and directions of future work are outlined. This paper is the first part in a series of two. Second part containing more computational results and comparison with test data will follow.
Modifications of a Two Stage Centrifugal Compressor for the Volute and Vaneless Diffuser Study
Authors: Rezaei Hooman , Engeda Abraham , Haley Paul 
Published: November 2021

Abstract
The objective of this work was to establish an advanced testing facility for studying the flow structure and loss mechanism in a single stage centrifugal compressor. A Trane’s CVHF 1280, two stage centrifugal compressor was modified to a single stage for laboratory environment. This modification included new fluid medium, driving motor, inlet and outlet designs. In this study, experiments were performed in order to evaluate the performance of the vaneless diffuser and volute. However, the modifications enable the flow structure investigation in all components of the compressor as well. In addition the testing facility would accommodate installation of the rest of the unit for investigation of the flow in the vaned diffuser and return channel of the two-stage compressor in the laboratory environment.
Experiments were performed in three speeds and eight mass flow rates per speed. Static and total pressures were measured at the inlet and outlet of the stage. Static pressure distributions were mapped on the vaneless diffuser and volute casings. These data evaluates the characteristics of these components after the modifications.
Performance Evaluation of Different Designs of Locomotive Intercoolers
Authors: Rajendran Veera P. , Furman Anthony H. , Record Barry A. 
Published: November 2021

Abstract
Heat exchangers of two different designs, used for the cooling of turbocharged air for locomotive diesel engines were experimentally studied to characterize the performance as well as to investigate the loss of effectiveness over time. Performance criteria including initial effectiveness, pressure drop and effectiveness degradation due to thermal shocks were characterized for a typical intercooler. Thermal and flow performance tests as well as severe shock tests were conducted in the laboratory at full-scale flow and geometric conditions to study the drop in effectiveness experienced in the field. The inlet Reynolds number for airside, based on the inlet flow conditions and pipe diameter is 2.13 × 105. The inlet Reynolds number for waterside, based on the inlet flow conditions and pipe diameter is 2 × 105. Mechanisms for the effectiveness drop due to thermal transients are discussed. Significant improvements in effectiveness degradation characteristics were achieved with a proposed new design while maintaining initial effectiveness. Overall, the new design was found to be significantly improved compared to the current design.
Simulations, Analysis and Thermoeconomical Synthesis of Heat Transfer Elements
Authors: Reznikov L. , Morosuk T. 
Published: November 2021

Abstract
Problems of analysis and design of intricate heat transfer elements are traditional for various industrial and experimental heat transfer units, including multichannel heat exchangers and multi-component fins. Authors suggest and introduce unified method of analysis and synthesis for these classes of heat transfer objects.
Authors’ method of simulations for such class of objects is based on step-by-step integration of local tangential and longitudinal heat flows with sequential computations of temperature fields in cycles of iterations and specific selection of boundary conditions. Variations of selected key factors provide arrays of design parameters for synthesis of new and optimized heat transfer objects.
Estimating the Initial Crack Size in a Particulate Composite Material: An Analytical and Experimental Approach
Authors: Liu C. T. 
Published: November 2021

Abstract
In this study, a technique to predict the equivalent initial crack size (EICS) in a particulate composite material, containing hard particles embedded in a rubber matrix, was developed using constant strain rate crack propagation test data. The accuracy of the developed technique was determined. In addition, the statistical distribution of the equivalent initial crack size follows the second asymptotic distribution of maximum value.
Biodynamics of Human Thorax With Body Armors Subject to Bullet Impact
Authors: Kwon Y. W. , Lobuono J. A. 
Published: November 2021

Abstract
The objective of this study is to develop a finite element model of the human thorax with a protective body armor system so that the model can adequately determine the thorax’s biodynamical response from a projectile impact. The finite element model of the human thorax consists of the thoracic skeleton, heart, lungs, major arteries, major veins, trachea, and bronchi. The finite element model of the human thorax is validated by comparing the model’s results to experimental data obtained from cadavers wearing a protective body armor system undergoing a projectile impact.
Material Considerations in Optimization of Machine Tool Structure
Authors: Kushnir Emmanuil F. , Patel Mahendra R. , Sheehan Terrence M. 
Published: November 2021

Abstract
The three most popular choices currently used for the main structural components of machine tools are steel weldments, metal (cast iron) castings and polymer composites. Among the three, polymer composite offers the highest vibration damping and the lowest thermal conductivity. All three approaches have been employed in the design of machine tools to meet the criteria for required rigidity, impact resistance and vibration damping. The final choice is also affected by additional factors including cost footprint (space) requirements and lead times.
For most production applications of machine tool structures, (gray cast iron) metal castings remain the primary choice because of cost, ease of sourcing, good damping with relatively high strength, good machinability and well-established and consistently achievable manufacturing and processing requirements. However, fabrications are normally the preferred choice for low volume production of large structures, due mainly to the high up-front molding costs and the difficulties in process control inherent in very large castings. On the other hand, with increasing, emphasis on high speed machining, hard turning, and better and consistent machining accuracies, structural rigidity, thermal stability and vibration damping are becoming major design considerations making polymer composites a leading choice.
For this reason, Hardinge Inc., a super precision machine tool builder has traditionally used its proprietary polymer composite (Harcrete®) in its lathe, grinder and machining center bases. Depending on the performance and cost requirements, the base can be all composite or a combination of conventional casting strategically reinforced with composite.
With the current market forces and ever increasing competition in the industry, for most machines, value engineering has become a prominent factor. A major consideration is to identify the materials and designs that would provide the best performance of the machine while minimizing the cost. Therefore, new sets of evaluation criteria are necessary to arrive at designs with optimum cumulative impact on various technical, commercial and strategic requirements. This paper proposes such new criteria and examines their suitability based on testing and analyses of structural components in today’s demanding real-world machine tool applications.
Tank Car Load Environment Under Impact Conditions
Authors: Prabhakaran Anand , Sharma Vinaya , Peńa Jose S. 
Published: November 2021

Abstract
High coupler vertical loads have been measured in revenue service tests conducted by the Association of American Railroads (AAR) as part of the ‘Freight Equipment Environmental Sampling Tests’ (FEEST) program. These high loads can induce cracks and/or accelerate crack propagation rates, causing premature tank car stub sill separation, leading to compromised safety of operation. This project was initiated to study the vertical load environment experienced by tank cars. A full scale test sequence with static and impact testing of a tank car was conducted, followed by test data analysis. A tank car loaded to 266,200 lb gross rail load (GRL) was instrumented and used as the test car. The static tests consisted of vertical load tests with forces being applied at the coupler head and squeeze tests with loads applied at the rear draft lugs. The impact tests consisted of 2 series of impacts at speeds ranging from 2 mph to 8.5 mph for three coupler mismatch levels. The results showed that significant vertical forces are generated during an impact event, even in the absence of any coupler height mismatch between impacting cars. On average, vertical force peaks of about 45,000 lb were observed at an impact speed of 7.5 mph even when the impacting cars were at the same level. It was also noted that under impact conditions, vertical forces induce 50% of the maximum stress seen at the tank head. Therefore, ignoring the effects of vertical force will lead to an under-estimation of stress levels and fatigue levels in tank cars. In addition, the vertical forces and stresses in critical areas of the stub sill-tank car interface are generally higher when the struck car is lower. Differences (in stress level) over 50% (compared to when the cars are level) were noted when the struck car was 2 in lower than the hammer car. In light of this, it seems prudent to minimize coupler height mismatch whenever and wherever feasible. This research effort was funded by the Office of Research and Development of the Federal Railroad Administration (FRA).
Vehicle/Track Interaction Tests of Three Freight Vehicles on Revenue Service Tracks
Authors: Li Dingqing , Kalay Semih F. , Shust William 
Published: November 2021

Abstract
Transportation Technology Center Inc. (TTCI), a subsidiary of the Association of American Railroads (AAR), conducted extensive vehicle/track interaction tests from 1998 to 2000 on revenue service tracks for three freight vehicles (covered hopper, tank car and coal gondola). During those tests, both track geometry and the corresponding vehicle response were collected simultaneously. All together, more then 1,400 miles of revenue tracks were tested on three North American railroads, covering a wide range of track and operation conditions. This paper presents the test results and findings in two main areas: how vehicle responses relate to measured track geometry conditions and how vehicle responses compare to the AAR Chapter XI (vehicle track worthiness) criteria. Vehicle response includes wheel/rail forces and L/V ratios via instrumented wheelsets, as well as car body accelerations. Track geometry conditions are characterized by curvature, superelevation, vertical surfaces, cross-level, lateral alignments, and gage.
Reduction of Dynamic Wheel/Rail Impact Forces at Grade Crossings Using Stiffness Transitions
Authors: Zarembski Allan M. , Palese Joseph W. , Katz Leonid 
Published: November 2021

Abstract
This paper presents the results of combined analytical and field study of the use of vertical stiffness transition zones to reduce dynamic wheel/rail impact forces at the interface between conventional track and high/rail grade crossings. These interfaces are traditionally sites of severe dynamic impact forces and corresponding rapid degradation of the geometry of the track. A recent FRA sponsored research study developed a new analytical technique to define the number of and magnitude of the stiffness transition zones needed to reduce the dynamic impact forces. This technique was used to design a series of transitions for a concrete grade crossing, which were installed on New Jersey Transit’s Atlantic City Line in the vicinity of ATCO New Jersey in 1998. Field tests performed on the grade crossing after installation showed a significant reduction in measured dynamic vertical accelerations across the grade crossing as compared to other crossings on the same line. Recent follow up evaluation of this grade crossing showed that it is performing significantly better than similar adjacent grade crossings on the same line and that there has been a marked reduction in degradation of the track/grade crossing and associated maintenance. This paper will present the results of the theoretical formulation, analytical study, and the field tests.
Wayside Truck Peformance Detector Development
Authors: Keegan L. S. , Blank R. W. , D’Aoust Denis , Earl Dana , Ford David 
Published: November 2021

Abstract
This paper describes the development of several wayside detectors for use in assessing the “dynamic” performance and general condition of freight car and locomotive trucks operating in revenue service. The objective is to improve safety of operations via automated wayside performance-based inspection systems and the development of performance-based criteria to improve and supplement existing maintenance policies and procedures.
On-Board Condition Monitoring System for Freight Trains
Authors: Donelson John , Zavis Wayne M. , Punwani S. K. (John) , Stewart Monique Ferguson , Edwards Mark C. 
Published: November 2021

Abstract
Science Applications International Corporation (SAIC) and Wilcoxon Research have developed a real-time on-board condition monitoring system for freight trains. The Office of Research and Development of the Federal Railroad Administration funded the development of the system. The system monitors bearings, wheels, trucks and brakes on freight trains in order to detect equipment defects and derailments. The objectives of the system are to improve railroad safety and operation efficiency through continuous monitoring of mechanical components on freight trains.
Effect of nutritionally modified infant formula on academic performance: linkage of seven dormant randomised controlled trials to national education data
Authors: Verfürden Maximiliane L , Gilbert Ruth , Lucas Alan , Jerrim John , Fewtrell Mary 
Published: November 2021

AbstractObjectiveTo compare differences in academic performance between adolescents who were randomised in infancy to modified or standard infant formula.DesignLinkage of seven dormant randomised controlled trials to national education data.SettingFive hospitals in England, 11 August 1993 to 29 October 2001, and schools in England, September 2002 to August 2016.Participants1763 adolescents (425 born preterm, 299 born at term and small for gestational age, 1039 born at term) who took part in one of seven randomised controlled trials of infant formula in infancy.InterventionsNutrient enriched versus standard term formula (two trials), long chain polyunsaturated fatty acid (LCPUFA) supplemented versus unsupplemented formula (two trials), high versus low iron follow-on formula (one trial), high versus low sn-2 palmitate formula (one trial), and nucleotide supplemented versus unsupplemented formula (one trial).Main outcome measuresThe primary outcome, determined by linkage of trial data to school data, was the mean difference in standard deviation scores for mandated examinations in mathematics at age 16 years. Secondary outcomes included differences in standard deviation scores in English (16 and 11 years) and mathematics (11 years). Analysis was by intention to treat with multiple imputation for participants missing the primary outcome.Results1607 (91.2%) participants were linked to school records. No benefit was found for performance in mathematics examinations at age 16 years for any modified formula: nutrient enriched in preterm infants after discharge from hospital, standard deviation score 0.02 (95% confidence interval −0.22 to 0.27), and nutrient enriched in small for gestational age term infants −0.11 (−0.33 to 0.12); LCPUFA supplemented in preterm infants −0.19 (−0.46 to 0.08) and in term infants −0.14 (−0.36 to 0.08); iron follow-on formula in term infants −0.12 (−0.31 to 0.07); and sn-2 palmitate supplemented formula in term infants −0.09 (−0.37 to 0.19). Participants from the nucleotide trial were too young to have sat their General Certificate of Secondary Education (GCSE) examinations at the time of linkage to school data. Secondary outcomes did not differ for nutrient enriched, high iron, sn-2 palmitate, or nucleotide supplemented formulas, but at 11 years, preterm and term participants randomised to LCPUFA supplemented formula scored lower in English and mathematics.ConclusionsEvidence from these randomised controlled trials indicated that the infant formula modifications did not promote long term cognitive benefit compared with standard infant formulas.
Exercise versus usual care after non-reconstructive breast cancer surgery (UK PROSPER): multicentre randomised controlled trial and economic evaluation
Authors: Bruce Julie , Mazuquin Bruno , Canaway Alastair , Hossain Anower , Williamson Esther , Mistry Pankaj , Lall Ranjit , Petrou Stavros , Lamb Sarah E , Rees Sophie , Padfield Emma , Vidya Raghavan , Thompson Alastair M 
Published: November 2021

Abstract

Objective
To evaluate whether a structured exercise programme improved functional and health related quality of life outcomes compared with usual care for women at high risk of upper limb disability after breast cancer surgery.

Design
Multicentre, pragmatic, superiority, randomised controlled trial with economic evaluation.

Setting
17 UK National Health Service cancer centres.

Participants
392 women undergoing breast cancer surgery, at risk of postoperative upper limb morbidity, randomised (1:1) to usual care with structured exercise (n=196) or usual care alone (n=196).

Interventions
Usual care (information leaflets) only or usual care plus a physiotherapy led exercise programme, incorporating stretching, strengthening, physical activity, and behavioural change techniques to support adherence to exercise, introduced at 7-10 days postoperatively, with two further appointments at one and three months.

Main outcome measures
Disability of Arm, Hand and Shoulder (DASH) questionnaire at 12 months, analysed by intention to treat. Secondary outcomes included DASH subscales, pain, complications, health related quality of life, and resource use, from a health and personal social services perspective.

Results
Between 26 January 2016 and 31 July 2017, 951 patients were screened and 392 (mean age 58.1 years) were randomly allocated, with 382 (97%) eligible for intention to treat analysis. 181 (95%) of 191 participants allocated to exercise attended at least one appointment. Upper limb function improved after exercise compared with usual care (mean DASH 16.3 (SD 17.6) for exercise (n=132); 23.7 (22.9) usual care (n=138); adjusted mean difference 7.81, 95% confidence interval 3.17 to 12.44; P=0.001). Secondary outcomes favoured exercise over usual care, with lower pain intensity at 12 months (adjusted mean difference on numerical rating scale −0.68, −1.23 to −0.12; P=0.02) and fewer arm disability symptoms at 12 months (adjusted mean difference on Functional Assessment of Cancer Therapy-Breast+4 (FACT-B+4) −2.02, −3.11 to −0.93; P=0.001). No increase in complications, lymphoedema, or adverse events was noted in participants allocated to exercise. Exercise accrued lower costs per patient (on average −£387 (€457; $533) (95% confidence interval −£2491 to £1718; 2015 pricing) and was cost effective compared with usual care.

Conclusions
The PROSPER exercise programme was clinically effective and cost effective and reduced upper limb disability one year after breast cancer treatment in patients at risk of treatment related postoperative complications.

Trial registration

ISRCTN Registry
ISRCTN35358984
.
Enteropathies with villous atrophy but negative coeliac serology in adults: current issues
Authors: Schiepatti Annalisa , Cincotta Marta , Biagi Federico , Sanders David S 
Published: November 2021

ObjectiveThe differential diagnosis and management of seronegative enteropathies is challenging due to the rarity of these conditions, the overlap of clinical and histopathological features and the current lack of an international consensus on their nomenclature.DesignThis is a narrative review providing pragmatic guide on the investigation and clinical management of seronegative enteropathies in adults based on the available literature and our clinical experience.ConclusionsSeronegative coeliac disease is the most frequent cause among the heterogeneous group of seronegative enteropathies and its diagnosis is confirmed by the clinical and histological response to a gluten-free diet after the exclusion of other causes of villous atrophy. Correct identification and targeted management of seronegative enteropathies is mandatory because of the variation in terms of clinical outcomes and prognosis.