bluuebunny/crossref_metadata_2025 huggingface dataset:
Update on Treatment Recommendations From the Fourth International Workshop on Waldenström's Macroglobulinemia
Authors: Dimopoulos Meletios Athanasios , Gertz Morie A. , Kastritis Efstathios , Garcia-Sanz Ramon , Kimby Eva K. , LeBlond Veronique , Fermand Jean-Paul , Merlini Giampaolo , Morel Pierre , Morra Enrica , Ocio Enrique M. , Owen Roger , Ghobrial Irene M. , Seymour John , Kyle Robert A. , Treon Steven P.
Published: December 2008

Waldenström macroglobulinemia (WM) is a distinct B-cell lymphoproliferative disorder characterized by lymphoplasmacytic bone marrow infiltration along with an immunoglobulin M (IgM) monoclonal gammopathy. Patients with disease-related cytopenias, bulky adenopathy or organomegaly, symptomatic hyperviscosity, severe neuropathy, amyloidosis, cryoglobulinemia, cold agglutinin disease, or evidence of disease transformation should be considered for immediate therapy. Initiation of therapy should not be based on serum IgM levels alone, and asymptomatic patients should be observed. Individual patient considerations should be considered when deciding on a first-line agent including the presence of cytopenias, need for rapid disease control, age, and candidacy for autologous transplantation. Therapeutic outcomes should be evaluated using updated criteria. As part of the Fourth International Workshop on Waldenström's Macroglobulinemia, a consensus panel updated its recommendations on both first-line and salvage therapy in view of recently published and ongoing clinical trials. The panel considered encouraging results from recent studies of first-line combinations such as rituximab with nucleoside analogs with or without alkylating agents or with cyclophosphamide-based therapies (eg, cyclophosphamide, doxorubicin, vincristine, and prednisone or cyclophosphamide and dexamethasone) or the combination of rituximab with thalidomide. Such therapeutic approaches are likely to yield responses at least as good as, if not better than, monotherapy with any of the alkylating agents, nucleoside analogs, or rituximab. In the salvage setting, reuse of a first-line regimen or use of a different regimen should be considered along with bortezomib, alemtuzumab, autologous transplantation, and, in selected circumstances, allogeneic transplantation. Finally, the panel reaffirmed its encouragement of the active enrollment of patients with WM onto innovative clinical trials whenever possible.
Triple Receptor–Negative Breast Cancer: The Effect of Race on Response to Primary Systemic Treatment and Survival Outcomes
Authors: Dawood Shaheenah , Broglio Kristine , Kau Shu-Wan , Green Marjorie C. , Giordano Sharon H. , Meric-Bernstam Funda , Buchholz Thomas A. , Albarracin Constance , Yang Wei T. , Hennessy Bryan T.J. , Hortobagyi Gabriel N. , Gonzalez-Angulo Ana Maria
Published: December 2008

Purpose

The goal of this study was to describe the effect of race on pathologic complete response (pCR) rates and survival outcomes in women with triple receptor–negative (TN) breast cancers.

Patients and Methods

Four hundred seventy-one patients with TN breast cancer diagnosed between 1996 and 2005 and treated with primary systemic chemotherapy were included. pCR was defined as no residual invasive cancer in the breast and axillary lymph nodes. Overall survival (OS) and recurrence-free survival (RFS) were estimated using the Kaplan-Meier product-limit method and compared between groups using the log-rank test. Cox proportional hazards models were fitted for each survival outcome to determine the relationship of patient and tumor variables with outcome.

Results

Median follow-up time was 24.5 months. One hundred patients (21.2%) were black, and 371 patients (78.8%) were white/other race. Seventeen percent of black patients (n = 17) and 25.1% of white/other patients (n = 93) achieved a pCR (P = .091). Three-year RFS rates were 68% (95% CI, 56% to 76%) and 62% (95% CI, 57% to 67%) for black and white/other patients, respectively, with no significant difference observed between the two groups (P = .302). Three-year OS was similar for the two racial groups. After controlling for patient and tumor characteristics, race was not significantly associated with RFS (hazard ratio [HR] = 1.08; 95% CI, 0.69 to 1.68; P = .747) or OS (HR = 1.08; 95% CI, 0.69 to 1.68; P = .735) when white/other patients were compared with black patients.

Conclusion

Race does not significantly affect pCR rates or survival outcomes in women with TN breast cancer treated in a single institution under the same treatment conditions.
Primary Retroperitoneal Sarcomas: A Multivariate Analysis of Surgical Factors Associated With Local Control
Authors: Bonvalot Sylvie , Rivoire Michel , Castaing Marine , Stoeckle Eberhard , Le Cesne Axel , Blay Jean Yves , Laplanche Agnès
Published: December 2008

Purpose

To define the optimal initial management and the best extent of surgery that would optimize margins on primary retroperitoneal sarcomas (RPS).

Patients and Methods

A total of 382 patients with primary RPS were analyzed. Sixty-five patients had a simple resection of the tumor, 120 patients had a complete compartmental resection (systematic resection of noninvolved contiguous organs), 130 patients had a contiguously involved organ resection, 21 patients had a systematic re-excision, 38 patients had an incomplete gross resection, and eight patients had a biopsy alone. Radiotherapy and chemotherapy were administered to 121 and 145 patients, respectively.

Results

One, 3-, and 5-year overall survival (OS) rates were 86% (95% CI, 0.82 to 0.89), 66% (95% CI, 0.61 to 0.71), and 57% (95% CI, 0.51 to 0.62), respectively. Median overall survival was 6 years. In the multivariate analysis, high grade, tumor rupture, gross residual disease, and positive margins were associated with decreased OS. Low grade, no tumor rupture, negative histologic margins, a high number of patients undergoing operation per center, and compartmental resection compared with standard procedures were associated with decreased abdominal recurrences. Compartmental resection is a significant variable, predicting a 3.29-fold lower rate of abdominal recurrence compared with simple complete resection.

Conclusion

Complete compartmental surgery without tumor rupture should be performed when possible to achieve clear margins. This surgery should be performed in a high-volume center. The role of adjuvant treatments should be evaluated in a randomized trial in association with this optimal surgery.
A review of the paper ‘A numerical solution to the elastohydrodynamic problem’ by D. Dowson and G. R. Higginson
Authors: Hooke C
Published: December 2008

Although some approximate solutions to the elastohydrodynamic lubrication (EHL) problem existed, no numerical calculation of the pressures and clearances under non-conformal contacts had been made. The problems were formidable: any iterative procedure tended rapidly to become unstable; without computers the calculations were lengthy and laborious. However, after 18 months of effort, four solutions were obtained and these laid the foundation for the development of the subject of EHL as a distinct field of study. While computer-based solutions are now available for virtually every type of problem, many of the original insights of these first solutions still apply.
Research on the reconstruction of the vibro-acoustic field generated by the complicated sources using the modified wave superposition algorithm
Authors: Zhang H B , Jiang W K , Huang Z Y , Wan Q
Published: December 2008

The nearfield acoustic holography (NAH) method based on the wave superposition algorithm (WSA) assumes that the sound field is induced by a series of simple sources inside the vibrational object boundary. The sound field can be reconstructed after the strength of virtual sources is determined in an inverse procedure. The theory, numerical simulation, and application of WSA-based NAH is often concerned with the simple sources. In practice, the vibrational objects are more complicated and sometimes should even be treated as multiple separated objects. The reconstruction of a sound field by using conventional WSA-based NAH directly is not satisfactory. In the presented modified WSA-based NAH, complicated vibrational objects are separated into several parts and looked at as independent components. Whole sound fields are generated by all these components. The comparisons between conventional and modified WSA-based NAH are carried out through numerical simulations. It shows that the more accurate result is obtained by applying the modified WSA-based NAH to the complicated objects. An experiment of a compressor with complicated structures is conducted to illustrate the validity of modified WSA-based NAH.
Fault diagnosis and prognosis for fuel supply systems in gas turbine engines
Authors: Kim K
Published: December 2008

This paper introduces a feature-extraction method to characterize gas turbine engine dynamics. The extracted features are used to develop a fault diagnosis and prognosis method for the fuel supply system in gas turbine engines. The engine start-up profiles of the core speed (N2) and the exhaust gas temperature collected with high-speed sampling rate are obtained and processed into a more compact data set by identifying critical-to-characterization instances. The fuzzy-clustering method is applied to the smaller number of parameters, and the fault is detected by differentiating the clusters matching the failures. In this work, the actual flight data collected in the field was used to develop and validate the system, and the results are shown for the test on nine engines that experienced fuel supply system failure. The developed fault diagnosis system detected the failure successfully in all nine cases. For the earliest detection cases, the alarms start to trigger 26 days before the system completely fails and 7 days in advance for the last detection.
Study of arc stability in underwater shielded metal arc welding at shallow depths
Authors: Mazzaferro J A E , Machado I G
Published: December 2008

The main objective of this work was to study the effects of changes in hydrostatic pressure and electrode coating composition on the shielding metal arc behaviour during underwater wet welding. Thus, wet welding operations were performed by an automatic device using a hyperbaric chamber to simulate depths of 5.0, 12.5, and 20.0 m. A covered electrode already developed in W & RTL was used as reference and compared with others with different amounts of CaCO3, TiO2, and aluminium added to their coatings. Hence, effects of welding condition and electrode coating on weld metal were evaluated through visual inspection of the weld beads, measurement of porosity level, and the results related to welding current and voltage signals. The welding arc signals were analysed through indexes calculated from instantaneous values of current and voltage, and fast Fourier transforms frequency spectrum. The mixtures containing CaCO3 additions exhibit fewer defects, while those containing aluminium additions have presented a great amount of pores and other discontinuities in the weld metal. As expected, all consumables showed a higher deposition rate, as welds were performed at greater depths (pressures), confirming the effect of arc constriction and the consequent increase in current density. Moreover, a region of transition in the metal transfer mode was identified around a depth of 12.5 m, probably from short-circuit to globular. Also, a clear tendency of increase in arc stability for those welds performed at greater depths could be noticed, as well as better weld metal quality. On the other hand, those consumables with CaCO3 added to the coating exhibited the best arc stability for welds performed at shallow depths.
Fourier method to function synthesis of an RCCC mechanism
Authors: Sun J W , Chu J K
Published: December 2008

The input—output function of an RCCC mechanism is investigated systematically by using the Fourier series method in this article. The relationship between the harmonic component of the input—output function and the dimensions of the RCCC mechanism is established. Based on this relationship, the basic dimensional type of the RCCC mechanism is determined. The problem of function synthesis of the RCCC mechanism is solved by setting up the numerical atlas database, which comprises 50 million basic dimensional types, and given the concrete steps of the function generator. Finally, an example is given to show the feasibility and the validity of this approach.
A computational study of real gas flows through a critical nozzle
Authors: Kim J-H , Kim H-D , Setoguchi T , Matsuo S
Published: December 2008

A critical nozzle is used to measure the mass flowrate of gas. It is well known that the coefficient of discharge of the flow in a critical nozzle is a single function of the Reynolds number, in which the discharge coefficient approaches unity as the Reynolds number increases. However, it has recently been reported that at very high Reynolds numbers, which correspond to high-pressure supply conditions, the discharge coefficient exceeds unity. This impractical value in the discharge coefficient is vaguely inferred to be due to real gas effects. The purpose of the present study is to investigate high-pressure hydrogen gas flow through a critical nozzle. A computational analysis has been carried out to simulate a critical nozzle flow with real gas effects. Redlich—Kwong's equation of state is incorporated into the axisymmetric, compressible Navier—Stokes equations to account for the inter-molecular forces and molecular volume of hydrogen. The computational results show that the critical pressure ratio and the discharge coefficient for ideal gas assumptions are significantly different from those of the real gas, as the Reynolds number exceeds a certain value. It is also known that the real gas effects appear largely in terms of the compressibility factor and the specific heat ratio, and these become more remarkable as the pressure of hydrogen increases.
Analytical method for locating the secondary instant centres of indeterminate planar linkages
Authors: Kung C-M , Wang L-C T
Published: December 2008

This article presents a new analytical method for locating secondary instant centres (SICs) of indeterminate planar linkages. In this method the SICs are first discriminated into three classes according to their level of geometric dependencies. The concepts of instant-centre digraph, instant-centre walk, and instant-centre circuit are then introduced to establish the recursive relationships between the classified instant centres. It is shown that the location of the instant centres within an instant-centre circuit can be evaluated recursively by first solving a second-order polynomial equation. In addition, by combining the recurrence conditions of several related instant-centre walks, the locations of SICs that are not within an instant-centre circuit can be solved analytically from a fourth-order polynomial equation. The proposed method does not rely on any velocity information or graphical techniques; therefore, it can be applied systematically to all types of indeterminate linkages. It can also be implemented on digital computers for automated analysis. Three numerical examples are presented to demonstrate the usage of this method.
A smoothing spline-based regularization of the initial inverse problem in a two-dimensional heat equation
Authors: Masood K , Mustafa M T
Published: December 2008

A smoothing spline-based method and a hyperbolic heat conduction model is applied to regularize the recovery of the initial profile from a parabolic heat conduction model in two-dimensions. An ill-posed inverse problem involving recovery of the initial temperature distribution from measurements of the final temperature distribution is investigated. A hyperbolic heat conduction model is considered instead of a parabolic model and smoothing splines are applied to regularize the recovered initial profile. The comparison of the proposed procedure and parabolic model is presented graphically by examples.
Optimization of spot-weld joints
Authors: Ertas A H , Sonmez F O
Published: December 2008

Integrity of the resistance spot welds determines the overall structural rigidity and integrity of the mechanical system. The main mode of failure for spot-weld joints is fatigue fracture due to fluctuating loads. Resistance spot welds are of great importance to manufacturing industry, considering that it is a commonly used technique for joining thin-sheet components of metals. For example, car and bus bodies may contain thousands of spot welds. Besides economic aspects, spot-welded structures drive the development of optimization in the field of spot welds.

Accordingly, the objective of this study is to develop a procedure to maximize the fatigue life or the load-carrying capacity of spot-weld joints by minimizing the maximum stress. In the optimization procedure, the material and size of the sheet plates are predetermined. On the other hand, the number and locations of the spot welds are chosen as design variables. In order to calculate the objective function, which is the maximum equivalent stress, ANSYS (version 9.0) finite-element analysis software is used. The procedure is applied to a representative problem to demonstrate the effectiveness of the proposed method.
Performance comparison of electrorheological valves with two different geometric configurations: Cylinder and plate
Authors: Han Y-M , Sung K-G , Sohn J W , Choi S-B
Published: December 2008

This article presents a control performance comparison of electrorheological (ER) fluid-based valves between cylindrical and plate configurations. After identifying Bingham characteristics of chemical starch-based ER fluid, an analytical model of each valve is established. In order to reasonably compare valve performance, design constraint is imposed by the choosing the same electrode gap and length, and each ER valve is manufactured. Valve performances such as pressure drop and response time are then evaluated and compared through analytical model and experiment. In addition, a time-varying pressure tracking controllability of each ER valve is experimentally realized.
Design and performance evaluation of a bellows-type mixture ratio stabilizer for a liquid bipropellant rocket engine
Authors: Jung Taekyu , Kwon Sejin
Published: December 2008

A stabilizer that maintains a steady propellant mixture ratio in a liquid bipropellant rocket engine was introduced. First, a design criterion for the ideal performance of a general stabilizer was derived. A new stabilizer with bellows (bellows-type stabilizer) was proposed in the present study and relevant design parameters were identified by a mathematical model as well as a theoretical analysis. Governing equations were established to predict the static behaviour of the stabilizer. A bellows-type stabilizer was fabricated and its performance was measured. The performance predicted by the mathematical model showed satisfactory agreement with measurements and this validates the adequacy of the mathematical model proposed in the present study.
Damage localization in hydraulic turbine blades using kernel-independent component analysis and support vector machines
Authors: Wang X H , Mao H L , Zhu C M , Huang Z F
Published: December 2008

A hydraulic turbine runner has a complex structure, and traditional source location methods do not have the higher accuracy to meet engineering requirements. The source location of crack acoustic emission (AE) signals in hydraulic turbine blades has been researched by combining it with kernel-independent component analysis (KICA) as feature extraction, with support vector machines (SVMs) as position recognition. This method is compared with those applied SVMs with feature extraction using kernel principal components analysis without feature extraction. The results show that the recognition rate in the crack region is 100 per cent by using both original AE parameters and feature parameters. Support vector regression by feature extraction using KICA can perform better than the other methods. As a result, it is a better method for source location of complex big size structures to combine KICA with SVM. It decreases the dimensionality of input signals and also improves the accuracy of location.
Correcting mass measurement of diesel particulate filters at non-ambient temperatures
Authors: Williams A M , Garner C P
Published: December 2008

Diesel particulate filters (DPFs) are becoming a widespread method for reducing the particulate matter (PM) emissions from both on-highway and off-highway automotive diesel engines. Mass measurements of DPFs are commonly used to determine rapidly both the amount of PM trapped by the filter and the amount regenerated (removed) by regeneration systems. To avoid issues with adsorption of atmospheric water the filters are often weighed at elevated temperatures. It is shown in this work that at elevated temperatures the filters weigh less than at lower temperatures as a direct result of the buoyant hot air within the filter substrate. This study shows that consideration of the buoyancy forces allows for correction of the mass measurement for the errors relating to the non-ambient temperature of the filter, allowing mass measurements at elevated temperatures while avoiding adsorption of atmospheric water on to the filter substrate and, therefore, improving the accuracy of mass-measurement-based studies of filtration and regeneration performance of DPFs. It is demonstrated that a filter with approximately 85 per cent overall porosity weighed at 150°C in ambient temperatures will have an error of about 0.3g/l (typically about 10 per cent of the trapped PM mass) in the mass measurement when not correcting for the temperature. By way of an example, this is shown to have potentially an important effect on the calculated trapped PM.
Modelling of a battery pack for electric vehicles using a stochastic fuzzy neural network
Authors: Wang J P , Xu L , Guo J G , Ding L
Published: December 2008

A dynamic simulation model for a battery pack is an important prerequisite for the simulation of electric vehicles. As the battery pack is a highly non-linear system, and their dynamic behaviour depends on different parameters, it is difficult to establish the relationship between the load voltage and the current under different temperatures and states of charge. Furthermore, the input and output data usually contain noise; therefore, the traditional neural-network-based model is affected while training the parameters. To solve the problem, a stochastic fuzzy neural network (SFNN) which has a filtering effect on the noisy input is used to model the battery non-linear dynamics in this paper. In the parameter-learning algorithm for the SFNN, a novel cost function which contains the error variables is studied. Then, the modelling test is performed on an 80A h nickel—metal hydride (Ni—MH) battery pack and the SFNN-based model for the Ni—MH battery pack is set up. The Federal Urban Driving Schedule cycle is performed to test the model. Compared with the traditional neural-network-based model, the SFNN model can simulate the battery dynamic better and has a filtering effect on the noisy input which is more suitable for practical applications.
Basic linear theory of handling and stability of automobiles
Authors: Lukowski S , Momot M , Kraemer D , Kunz D
Published: December 2008

The directional response and stability characteristics of the motor vehicle are examined by considering the automobile to be a mechanical system which is described by linear differential equations with constant coefficients. The directional response behaviour and stability characteristics of the motor vehicle are important performance modes of vehicle operation often equated with handling. The objective of this analysis is to show how steady state turning behaviour depends upon various vehicle design factors and motion variables. A family of characteristic handling diagrams are obtained for linear and non-linear ranges of tyre operation. The handling diagrams show the dependence of the vehicle's directional behaviour upon the tyre lateral force characteristics, the front and rear load distributions, and the vehicle's forward speed. Information obtained from this study of vehicle response to steering control gives insight into the turning behaviour of a real vehicle and is useful for safety objectives.
Straight-line braking dynamic analysis of a partly filled baffled and unbaffled tank truck
Authors: Yan G , Rakheja S
Published: December 2008

The straight-line braking performance characteristics of a partly filled tank truck with and without transverse baffles are investigated in the presence of transient fluid slosh within the tank. The dynamic interactions of the floating cargo with the vehicle are evaluated by integrating a dynamic fluid slosh model of the partly filled tank with and without transverse baffles with the seven-degrees-of-freedom pitch plane model of a tridem truck. The dynamic fluid slosh within the tank containing equally spaced four curved single-orifice baffles with flow equalizer is modelled using three-dimensional Navier—Stokes equations coupled with the volume-of-fluid equation and analysed using the FLUENT software. The coupled tank—vehicle model is subsequently analysed to determine the straight-line braking properties for different fill volumes, magnitudes of braking treadle pressure, and road surface adhesion coefficients, while the cargo load is considered to be constant. The results show interactions of the sloshing cargo with the vehicle. A degradation of the braking performance of the partly filled tank truck is evident in the presence of transient fluid slosh, particularly in the absence of baffles. The braking performance, however, is highly dependent upon the fill volume, presence of baffles, and severity of braking input. For a clean-bore tank truck, the stopping distance increases monotonically with decreasing fill volume, while the addition of transverse baffles in general results in considerably shorter stopping distance. The baffled tank truck, however, reveals a relatively shorter stopping distance under an intermediate fill condition (approximately 52.1 per cent), compared with the lower and higher fill volumes. Although the analyses are limited to conventional single-orifice baffles, the proposed coupled vehicle—tank model could serve as an important tool for exploring alternative baffle designs and layouts.
Effect of the compression ratio on the performance and combustion of a natural-gas direct-injection engine
Authors: Zheng J-J , Wang J-H , Wang B , Huang Z-H
Published: December 2008

An experimental study on the combustion and emissions of a natural-gas direct-injection spark ignition engine under different compression ratios was carried out. The results show that the compression ratio has a large influence on the engine performance, combustion, and emissions. The penetration distance of the natural-gas jet is decreased and relatively strong mixture stratification is formed as the compression ratio is increased, giving a fast burning rate and a high thermal efficiency, especially at low and medium engine loads. However, the brake thermal efficiency is increased with a compression ratio up to a limit of 12 at high engine loads. The maximum cylinder gas pressure is increased with increase in the compression ratio. The flame development duration is decreased with increase in the compression ratio and this behaviour becomes more obvious with increase in the compression ratio at low loads or for lean mixture combustion. This indicates that the compression ratio has a significant influence on the combustion duration at lean combustion. The exhaust hydrocarbon (HC) and carbon monoxide emissions decreased with increase in the compression ratio, while the exhaust nitrogen oxide emission is increased with increase in the compression ratio. The exhaust HC emission tends to increase at high compression ratios. Experiments showed that a compression ratio of 12 is a reasonable value for a compressed-natural-gas direct-injection engine to obtain a better thermal efficiency without a large penalty of emissions.
Assessment of vertical track geometry quality based on simulations of dynamic track—vehicle interaction
Authors: Li M X D , Berggren E G , Berg M
Published: December 2008

A study assessing vertical track geometry quality based on simulations of dynamic track—vehicle interaction is presented in this article. The dynamic model is composed of track, vehicle, and wheel—rail contact with moving irregularities and is solved in the frequency domain by fast Fourier transform or in the time domain by constructing a filter function based on system identification. Frequency-dependent stiffness and loss factor of railpads are used in this study. Numerical simulations are carried out for a 120 km long track to demonstrate the potential benefits of enhancing track quality assessment by calculating wheel—rail forces.
Predicting crack growth and risks of rail breaks due to wheel flat impacts in heavy haul operations
Authors: Sandström J , Ekberg A
Published: December 2008

The risk for rail breaks is investigated from mechanical and statistical points of view with particular focus on the influence of impact loads from flatted wheels. For a presumed rail head crack geometry and rail temperature, the stochastic relation between the crack position along the rail and the wheel flat impact position results in a risk of fracture. In addition to the analysis of the risk for final fracture, rail crack growth is also studied. In particular, the contribution of wheel flat impacts on crack growth rates is quantified.

The study takes the form of a dynamic load analysis that evaluates rail bending moments due to wheel flat impact. Then, a fracture mechanics analysis is employed to establish stress intensity factors for rail head cracks under bending and temperature loading. These analyses are then combined to give risks of rail breaks and to quantify crack growth rates for varying operational conditions.
Performance-based track geometry and the track geometry interaction map
Authors: Liu Y , Magel E
Published: December 2008

The track geometry interaction map (TGIM) is proposed as an effective way to evaluate the impact of multiple track geometry parameters on rail safety. Multi-body dynamics software has been used to simulate vehicle performance over tracks containing a large number of randomly generated lateral and vertical track geometry combinations. A TGIM-based safety threshold is generated that appears to offer both economic and safety advantages over the current Federal Railroad Administration track safety standards.
An overview of rolling stock and track monitoring systems and guidelines to provide safety of heavy and long train operation in the Russian Railways
Authors: Cherkashin U M , Zakharov S M , Semechkin A E
Published: December 2008

An analysis of statistics on derailment of freight trains in the Russian Railways is carried out. Some results of simulation of vehicle—track interaction and experimental studies on moving of empty cars along track sections with diverse combination of horizontal and vertical irregularities are presented. An overview of guidelines to provide safety of heavy and long train operation is also presented. Technical means of rolling stock and track condition monitoring that is used and developing in the Russian Railways is described. Existing and developing wayside and on-board automated monitoring systems enabling continuous control over moving rolling stock and track are discussed. To provide safety of heavy haul operation, a general concept of a complex system of safety management based on monitoring of rolling stock and track is suggested.
A parametric study of the effects of freight vehicles on rolling contact fatigue of rail
Authors: Tunna J , Urban C
Published: December 2008

The steering forces between the rail and wheels of freight vehicles can cause rolling contact fatigue (RCF) of the rail under normal curving conditions. A parametric study has been performed to quantify the effects of various freight vehicle parameters on the generation of RCF. The parameters that vary include primary clearances and stiffnesses, bogie and axle spacing, side bearing clearances, track geometry, unsprung mass, axle load, and wheelset conicity. Three different freight suspensions have been considered: an enhanced three-piece bogie, a rigid-frame bogie with primary suspension, and a two-axle vehicle with leaf springs. Simulations were performed for track curvature ranging from 400 to 10 000 m. The results show that some parameters have a significant effect on RCF, whereas others have no, or only a slight effect. The conclusions are intended to help analysts to focus their future studies on these important freight vehicle parameters.
Numerical study of the mechanical deterioration of insulated rail joints
Authors: Sandström J , Ekberg A
Published: December 2008

Numerical simulations are performed to study plastic deformation and fatigue impact of an insulated joint. The simulations feature a sophisticated constitutive model capable of capturing ratcheting under multi-axial loading conditions. Calculation results are presented in the form of effective strain magnitudes, plastic zone sizes, and multi-axial low cycle fatigue parameters. The simulation results indicate that the main damage mechanism at insulated joints is ratcheting and not low cycle fatigue.

A parametric study quantifies effects of increased vertical and longitudinal load magnitudes, as well as the effect of an increased insulating gap. In particular, longitudinal loading is indicated as being severely deteriorating for the rail in the vicinity of the joint. Finally, the effect of rail edge bevelling is assessed and found to be small for the case studied.
Effect of oil and water mixtures on adhesion in the wheel/rail contact
Authors: Lewis R , Gallardo-Hernandez E A , Hilton T , Armitage T
Published: December 2008

This article details the findings of a series of twin disc machine adhesion tests that investigated the effects of oil and water mixtures on adhesion at the wheel/rail interface. Oil was found to have a dominant effect on adhesion in the presence of water. Surfaces coated with oil at 4.7×10−3 g/cm2 and sprayed with water had levels of adhesion similar to those coated by a replenishing supply of oil. The tests showed that drying a wet contact can initially give a reduction in adhesion, that increased roughness results in increased adhesion in the presence of oil, and that increased contact pressure improves adhesion in the presence of oil.
Shock tunnel studies on cowl/ramp shock interactions in a generic scramjet inlet
Authors: Mahapatra D , Jagadeesh G
Published: December 2008

An experimental study is presented to show the effect of contraction ratio (CR) on shock interaction phenomena for a two-dimensional, planar scramjet inlet model. Experiments are conducted in a hypersonic shock tunnel, at Mach 8, at three CRs: 8.4, 5.0, and 4.3. CR here is defined as the ratio of the projected inlet area to the throat area. Investigations include Schlieren flow visualization around the cowl region and heat transfer rate measurement inside the inlet chamber. Various ramp/cowl shock interaction processes ahead of the inlet have been visualized using a high-speed camera. Edney type II interference pattern is observed for a CR of 4.3 with all its typical features resulting because of the forebody shock/cowl shock interaction. Peaks in the heat transfer rate measured inside the chamber show possible locations of shock impingement because of the shock interaction inside the inlet.
Breathing blunt-nose concept for drag reduction in supersonic flow
Authors: Vashishtha A , Rathakrishnan E
Published: December 2008

This paper presents the results and the physics behind the process which results in the reduction of pressure drag of blunt-nosed body by passive control in form of breathing nose at a supersonic Mach number. The drag of a blunt-nosed body with and without breathing nose at Mach 1.96 is compared. The breathing nose is found to reduce the drag on the body by manipulating the high pressure at the nose and the low pressure at the base simultaneously. The shock at the nose of the body becomes weaker when the hole at the nose is open. Direct measurement of drag and the pressure at the nose and at the surface downstream of the nose has been carried out. Flow field around the body with and without breathing nose has been visualized with shadowgraph. A maximum drag reduction of 21 per cent was obtained at NPR 2. This is because of the combined effect of the decrease of high pressure at the nose and increase of low pressure at the base, due to the breathing through the nose hole.
Numerical analysis of pseudo-shock flow diffusion phenomenon in variable cross-section ducts
Authors: Wang C-P , Tian X-A , Cheng K-M , Wu Y-Z
Published: December 2008

The pseudo-shock wave (PSW) region of flow diffusion, which appears when a supersonic flow in a duct decelerates to a subsonic flow, is a complicated process involving a multi-faceted interaction between the duct's peripheral boundary layer and the central shock-wave field. It is made up of an upstream shock train region, comprised of lambda and oblique shock waves, and a downstream mixing region, both of which significantly influence the effective performance of the desired flow diffusion process. In this article, the PSW in two variable-cross-sectional ducts, edge- and corner-varied in transforming from a rectangular to a circular duct moving downstream, was researched through computational fluid dynamics (CFD) numerical simulation. The PSW flowfields in circular and rectangular ducts were also computed to be counterparts. The identical inflow parameters ( Ma = 2.0, T0 = 298 K and P0 = 100 kPa) in combination with different pressure ratios ( Pb/ Pi = 2.8—3.8) were considered. The characteristics of the PSW phenomenon, such as the leading edge of the PSW, length of the shock train, mass-weighted average parameters at the exit, and so on, were analysed. For these cases, with the same pressure ratio Pb/ Pi = 3.8, the shock train length in the corner-varied duct is the shortest, and its capability of supporting backpressure is the weakest of the four ducts. For these cases, with the same leading edge of the PSW at X = 0.167 L, a shorter and wider corner flow separation region appears in the variable-cross-sectional edge-varied duct in comparison with the rectangular duct. With regard to the length of shock train, level of internal drag, and capability to support backpressure, the edge-varied duct is the superior design choice. An advantage of the edge-varied duct is the improved internal drag: an additive thrust is produced to partly offset the drag due to the duct's axial divergence-angle setting. Based on an analysis of the PSW flow pattern in these ducts, it has been established that the wall-pressure distributions of the shock train can be well predicted by the modified Waltrup formula after the introduction of an equivalent diameter and an exponent α for Reθ.
Data-driven fault detection and estimation in thermal pulse combustors
Authors: Chakraborty S , Gupta S , Ray A , Mukhopadhyay A
Published: December 2008

This paper presents the development of a dynamic data-driven statistical method for: (a) early detection of incipient faults and (b) parameter estimation for prognosis of forthcoming failures and operational disruptions (e.g. flame extinction) in thermal pulse combustors. From these perspectives, reduction in the tailpipe friction coefficient is estimated from time-series data of pressure oscillations. The algorithms for parameter estimation are built upon the principles of Symbolic Dynamics, Information Theory and Statistical Pattern Recognition. The proposed algorithms have been tested on an experimentally validated simulation model of a generic thermal pulse combustor.
Viscoelastic finite element analysis of the cervical intervertebral discs in conjunction with a multi-body dynamic model of the human head and neck
Authors: Esat V , Acar M
Published: December 2008

This article presents the effects of the frontal and rear-end impact loadings on the cervical spine components by using a multi-body dynamic model of the head and neck, and a viscoelastic finite element (FE) model of the six cervical intervertebral discs. A three-dimensional multi-body model of the human head and neck is used to simulate 15 g frontal and 8.5 g rear-end impacts. The load history at each intervertebral joint from the predictions of the multi-body model is used as dynamic loading boundary conditions for the FE model of the intervertebral discs. The results from the multi-body model simulations, such as the intervertebral disc loadings in the form of compressive, tensile, and shear forces and moments, and from the FE analysis such as the von Mises stresses in the intervertebral discs are analysed. This study shows that the proposed approach that uses dynamic loading conditions from the multi-body model as input to the FE model has the potential to investigate the kinetics and the kinematics of the cervical spine and its components together with the biomechanical response of the intervertebral discs under the complex dynamic loading history.
Jar-opening challenges. Part 1: An apparatus for assessing hand and finger torques and forces in a jar-opening activity
Authors: Su F-C , Chiu H-Y , Chang J-H , Lin C-F , Hong R-F , Kuo L-C
Published: December 2008

A simulated jar apparatus was developed to record hand kinetics and torque contribution of a digit during jar-opening activities. The design of the apparatus, namely a jar body and a lid, is similar to a commercial jam jar that is regularly seen in daily living. One six-axis force—torque transducer and a torque cell were mounted inside the jar lid to detect the external force exerted from the digit and fixed on to the jar body to record the overall torque generated by the hand and wrist respectively. The applications of the apparatus were used to test the twisting torque of the hand and to measure the applied forces of the digit, which are both important factors in opening a jar. The contribution of each digit relative to the total twisting torque of the hand could be obtained via the apparatus. The intraclass correlation coefficient of the repeated measurements of the obtained forces and moments for different counterweights was approximately 0.96—1.00, which indicates that the reliability of the measured components of the apparatus is high. The high coefficient of determination ( r2 > 0.99) indicates high accuracy of prediction of the measured values with respect to the expected loads. The validation outcomes support the design rationale and actual body part of the simulated jar. In addition, understanding the contribution of a single digit in opening a jar was also achieved via the apparatus and model.
Analysis of body responses to an accelerating platform by the largest-Lyapunov-exponent method
Authors: Acharya U R , Goh S C , Iijima K , Sekine M , Tamura T
Published: December 2008

Various disciplines have benefited from the advent of high-performance computing in achieving practical solutions to their problems, and the area of health care is no exception to this. Non-linear signal-processing tools have been developed to understand the hidden complexity of the time series, and these will help clinicians in diagnosis and treatment. Postural study helps the elderly and people with a balancing problem due to various pathological conditions. In elderly subjects, falls are common and may result in injury. Correct postural balance is basic to well-being and it influences our daily life significantly. These postural signals are non-stationary; they may appear to be random in the time scale and it is difficult to observe the subtle changes for the human observer. Hence, more hidden information can be obtained from the signal using non-linear parameters. In this paper, ten young normal subjects are subjected to the balancing platform whose acceleration is gradually increased from 1 m/s2 to 5 m/s2 to study the postural response. The ankle front—back acceleration and ankle pitch angular velocity sensor data were studied using the largest Lyapunov exponent (LLE). The results show that for higher acceleration of the platform the ankle movement follows a particular rhythm, resulting in a lower Lyapunov exponent. During lower acceleration of the balancing platform, this value is higher because of the random movement of the ankle. In this work, the pattern of the body response was studied using LLE values for different accelerations using ankle data as the base signal for the normal subjects.
Pitch-based carbon-fibre-reinforced poly (ether—ether—ketone) OPTIMA® assessed as a bearing material in a mobile bearing unicondylar knee joint
Authors: Scholes S C , Unsworth A
Published: December 2008

The introduction of unicondylar knee prostheses has allowed the preservation of the non-diseased compartment of the knee while replacing the diseased or damaged compartment. In an attempt to reduce the likelihood of aseptic loosening, new material combinations have been investigated within the laboratory. Tribological tests (friction, lubrication, and wear) were performed on metal-on-carbon-fibre-reinforced (CFR) poly (ether—ether—ketone) (PEEK) (pitch-based) mobile unicondylar knee prostheses up to 5×106 cycles. Both a loaded soak control and an unloaded soak control (both medial and lateral components) were used to compensate for weight change due to lubricant absorption. For this material combination the loaded soak control gave slightly lower wear for both the medial and the lateral components than did the unloaded soak control. The medial components gave higher steady state wear than the lateral components (1.70 mm3 per 106 cycles compared with 1.02 mm3 per 106 cycles with the loaded soak control). The results show that the CFR PEEK unicondylar knee joints performed well in these wear tests. They gave lower volumetric wear rates than conventional metal-on-ultra-high-molecular-weight polyethylene prostheses have given in the past when tested under similar conditions. The friction tests showed that, at physiological viscosities, these joints operated in the boundary—mixed-lubrication regime. The low wear produced by these joints seems to be a function of the material combination and not of the lubrication regime.
Flexible linkage structural vibration control on a 3-PRR planar parallel manipulator: Experimental results
Authors: Zhang X , Mills J K , Cleghorn W L
Published: December 2008

Piezoelectric actuators and sensors have been used for vibration control of flexible manipulators and mechanisms since the 1990s. However, very few attempts have been made toward experimental investigations compared with numerical simulations, especially for mechanisms and manipulators with multiple flexible links. This paper presents an experimental study on active vibration control of a moving 3-PRR parallel manipulator with three flexible intermediate links with bonded lead zirconate titanate (PZT) actuators and sensors. First, experimental modal tests are conducted with an impulse force hammer and an accelerometer to identify structural vibration mode shapes and natural frequencies of the flexible manipulator. These modal test results are used to provide guidance for the determination of the location of PZT transducers and the design of an active vibration controller. Then, a strain rate feedback (SRF) controller is designed in modal space. A state-space model is formulated with the control input voltage applied to PZT actuators, and output generated voltage from PZT sensors. The design of an optimal active vibration controller is addressed based on SRF. Furthermore, to suppress the noise introduced through the differentiation of the strain signal, a second-order auxiliary compensator is introduced to the SRF controller. The design of the SRF controller and the noise attenuation compensator is addressed utilizing vibration theories. Finally, active vibration control experiments are implemented to demonstrate that the proposed active vibration control strategy is effective. Power spectral density plots of vibrations illustrate that the structural vibration of flexible links is suppressed effectively when the proposed SRF vibration control strategy is employed.