bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Influence of Lubrication on Tooth-Roller Impacts in Chain Drives
Authors: Fawcett J. N. , Nicol S. W. 
Published: October 2007

In a roller chain drive an impulsive load occurs each time a roller is picked up by the driving sprocket from the chain span. These impulsive loads cause high frequency sprocket angular accelerations of large amplitude, and are the source of high frequency chain noise. Measurements of sprocket acceleration immediately after impact have been made to demonstrate the effects of different methods of lubrication on the magnitude of the impulse. Oil drip, oil jet and oil bath lubrication have been investigated for normal machine oil and very high viscosity oil. The results show considerable variations in acceleration amplitude.
The Development, Application and Experimental Evaluation of a Design Procedure for Centrifugal Compressors
Authors: Came P. M. 
Published: October 2007

A computer-based centrifugal compressor design procedure developed at the National Gas Turbine Establishment is described. The impeller design package includes a geometry modelling procedure, aerodynamic analysis, stress analysis, and the direct generation of data for manufacture by numerical control. The method of diffuser design incorporates analyses of the flow in the vaneless space and ‘semi-vaneless’ space adapted from a new performance prediction technique; published diffuser pressure recovery data are used in the selection of the diffuser channel geometry. The application of these methods to the design of a 6.5 pressure ratio centrifugal compressor stage is described. The experimental rig testing of this compressor has been used to evaluate the advantages offered by the new design procedure. By comparing the measured performance with that of an earlier compressor designed with less advanced techniques for the same aerodynamic duty, the advantages of the new design procedure are established.
Axisymmetric Flow in a Motored Reciprocating Engine
Authors: Gosman A. D. , Melling A. , Whitelaw J. H. , Watkins P. 
Published: October 2007

A study was made of axisymmetric, laminar and turbulent flow in a motored reciprocating engine with flow through a cylinder head port. Measurements were obtained by laser-Doppler anemometry and predictions for the laminar case were generated by finite-difference means. Agreement between calculated and measured results is good for the main features of the flow field, but significant small scale differences exist, due partly to uncertainties in the inlet velocity distribution. The measurements show, for example, that the mean velocity field is influenced more strongly by the engine geometry than by the speed. In general, the results confirm that the calculation method can be used to represent the flow characteristics of motored reciprocating engines without compression and suggest that extensions to include compression and combustion are within reach.
High Speed Train - Fleet Operation
Authors: Power S. R. D. 
Published: October 2007

In October 1976 British Rail introduced its first 200 km/h service on the London-Bristol and London-South Wales services. This followed several years of design work and extensive testing of a prototype train. The increase in passenger traffic on these routes, during the first two years of high speed operation, clearly indicates that there is a demand for such a service and that the train itself fully meets the need from the passenger viewpoint. Unlike some railway administrations, who have built separate lines dedicated to high speed services, it is British Rail policy to operate these units on the existing network, sharing it with passenger and freight trains running at conventional speeds. Because of this policy the designer is constrained by track impact force limitations specified by the Civil Engineer and he must also ensure that the train can be operated safely within the existing signalling arrangements. Bearing in mind the extent of technical innovation it is not surprising that a number of problems have arisen. However, as a result of prompt and effective action on the part of both the railway and the railway supply industries, modifications have soon been introduced to eliminate the problems. The paper starts with a brief description of the train and the facilities provided to ensure adequate maintenance resources both within regional depots and railway workshops. This is followed by a review of experience to date and the paper concludes with a forecast about future trends in high speed operation.
Die Casting of Major Engine Components
Authors: Nakashima W. , Ebisawa M. 
Published: October 2007

‘Aluminum and automobiles’ are closely linked to the progress and development of the automobile industry. Moreover, at this time when energy conservation is the prime requisite, manufacturers are compelled aggressively to pursue weight reduction and compactness in designs of future automobiles. As a result, lightweight alloys, in particular aluminum and magnesium, are in ever increasing use as materials for automobile components. A very good example of the extent of lightweight alloys used in automobiles was very evident at the 1976 international conference on aluminum and the motor car held in West Germany. On display were aluminum bumpers, truck cabs, door panels, bonnets, steering columns and numerous other parts, indicating the rapid trend toward weight savings by broadening the use of aluminum materials. However, even though great strides have been achieved in weight savings through design, a full market acceptance cannot be realized unless products of stable quality and low manufactured cost can be made available. Discussed herein is the approach being taken by Honda Motor Company to cope with this subject. The focal points to be discussed are the existing production line which produces the large engine cylinder block die casting, and future development of aluminum die casting.
Computer Analysis of Three-Dimensional Turbulent Flows around Ships' Hulls
Authors: Markatos N. C. , Malin M. R. , Tatchell D. G. 
Published: October 2007

This paper describes a general solution method for three-dimensional, steady, turbulent flows around long, smoothly-shaped bodies, of arbitrary and varying cross-sectional shape. The particular example considered here concerns the flow around the hull of a ship, but the method can equally well be applied to other, similarly shaped bodies such as an aircraft fuselage, or a submarine. Moreover, the basic non-orthogonal grid method described can also be applied to internal flows in irregular shaped passages, or to the prediction of flows around bodies in ducts. The mathematical model consists of the partial differential equations for continuity and three components of momentum, along with a two-equation model of turbulence, and proper modelling of the ship's hull. The solution method utilizes a non-orthogonal coordinate system in the plane normal to the axis of the body, which has one coordinate surface coinciding with the hull surface. This coordinate system is flexible and is easily modified to enable the calculation procedure to handle bulbous ships' hulls, which are of great importance in modern ship design. The differential equations involved are solved numerically after provision of the proper boundary and initial conditions. The solution procedure is a unique one, called ‘partially-parabolic’, as first used by Pratap and Spalding (1). Solutions are presented for flow around ships' hulls, which demonstrate the physical realism of the achieved results and the potential of the present method.
Unsteady Airflows in Rapid Transit Systems
Authors: Vardy A. E. 
Published: October 2007

The principal aerodynamic effects in a rapid transit system are predicted by use of a computer program. Account is taken of the influence of cross-passages, ventilation shafts, cross-overs and stations, etc. on the airflows generated by any number of trains travelling along any routes with any speed histories. Very few empirical coefficients are needed to obtain satisfactory correlations with experimental data. The program is used to investigate the relative influence of important system parameters, and skin friction is found to have a particularly strong effect. It is shown that the tunnel system can be considerably simplified in the numerical simulation without serious loss of accuracy, but that account must be taken of local cross-passages and ventilation shafts.
Corrosion Protection Methods on Rolls-Royce Motor Cars
Authors: Creer T. F. 
Published: October 2007

The need for a high level of corrosion resistance in motor cars continues to increase. In the view of Rolls-Royce Motors it can only be achieved by careful application of suitable systems and an appreciation of the processes by the designers. For components and assemblies in critical areas, tests have been developed to ensure the limitations of corrosion protection methods over long service periods are understood, particularly for parts operating in close proximity. Promising developments to achieve weight saving and environmental improvements without sacrificing corrosion resistance are under investigation.
Traction Motor Experience on Toronto Subway
Authors: Jowett W G 
Published: October 2007

The paper gives a brief history of the Toronto Subway and how a British company became involved in the supply of prototype traction motors to the Toronto Transit Commission (TTC) followed in 1971 by the supply of motors for the H2 stock. On the test bed these motors were shown to be up to specification with reasonable margins on rating and commutation, but after varying periods in service, problems arose which were dealt with and overcome effectively except for one problem connected with commutator face erosion, which became known as the TIR problem'2, the cause of which proved to be most elusive. The main content of the paper concerns the search for the cause and a solution to this problem. In 1973, TTC called for tenders for further subwaycars (the H4 stock). At this stage, causes and solutions to the TIR problem had been suggested and interim results were promising. However, after negotiating special guarantees, eventually an order was received for H4 stock motors which incorporated improvements and the suggested remedies to the ‘TIR problem’. These motors have now satisfactorily completed over 400 000 miles in service showing that the solutions applied were sound and effective and it is now estimated that the period between commutator skimming will be 500 000 miles or over.
The Testing and Approval of Aircraft Engine Mounted Accessories
Authors: Pearson D S 
Published: October 2007

Vibration measurements on gas turbine engines are normally made using accelerometers. The environment to which engine accessories would be subject has been evaluated by comparing ‘g’ peaks in the frequency spectrum, individually, with empirical yardsticks of severity. Endurance approval testing of accessories to withstand the environment so characterized is normally conducted by applying unidirectional single frequency excitation to simulate engine conditions at a particular shaft speed. These procedures have proved inadequate in predicting failure or verifying corrective measures where accessory problems due to wear phenomena are concerned. This paper analyses reasons for this inadequacy in terms of measurement practice, engine severity assessment, environmental simulation and approval procedures. By recognizing the effect of multi-frequency vibration in three planes it further aims to provide a unified approach to accessory design and development by which service accessory reliability might be improved. Although at first sight more expensive, the approach described will in many cases reduce to previous practice. In cases where greater test expenditure is necessary, loopholes will have been plugged by which many expensive service problems previously escaped.
Noise Control in the Design of Process Plants
Authors: Erskine J B 
Published: October 2007

The design of process plant must incorporate noise control since retro-fitting is impractical on both technical and economic grounds. Whilst the method of approach depends on particular circumstances, key factors common to all projects are: setting of realistic specifications; establishing working procedures which ensure full co-operation by all members of the design team; early identification of the most difficult problems so that the most economic solutions can be generated; utilization of good and bad experience from previous projects to minimize noise control costs, this forms the basic work load in most projects; evaluation of the completed plant so that the degrees of success can be determined and lessons can be learned for future projects. These, and some technical aspects, are covered in the paper and whilst they are based on experience with large process plants they are equally applicable to smaller plants. The need for ‘in house’ knowhow is essential to the whole exercise since the noise sources are a function of the process and much of the data is of an empirical and practical nature.
‘Things can only get Better’: expectations and the welfare state
Authors: Taylor-Gooby Peter 
Published: October 2007

English
An influential recent study argues that disenchantment with the achievements of the welfare state results from the comparison between modest welfare performance and the improvements in standards of provision in the non-state sector associated with rising living standards (Glennerster and Hills, 1998). This article analyses recent data from the British Social Attitudes survey to show that dissatisfaction in the flagship area of the National Health Service is associated with underprivilege rather than secure and rising standards of living. The implication is that the traditional defence of state welfare, as providing for those who experience needs which they find difficult to satisfy through the market, may still strike a chord with public opinion.
The Judiciary in the 1990s: guardian of the welfare state?
Authors: Woodhouse Diana 
Published: October 2007

English
During the 1990s there have been indications that a number of senior judges are concerned to protect and preserve the principles upon which the UK welfare state is based. In addition, they see a correlation between welfare provisions and fundamental human rights and, in some instances, view a withdrawal of these provisions as an infringement of human rights. This article examines judicial attitudes in cases which have raised benefit, health and education issues and suggests that the incorporation of the European Convention on Human Rights may have the effect of increasing the role of the judiciary as guardian of the welfare state.
Structure and dynamics of levitated liquid materials
Authors: Hennet Louis , Krishnan Shankar , Pozdnyakova Irina , Cristiglio Viviana , Cuello Gabriel J. , Fischer Henry E. , Bytchkov Aleksei , Albergamo Francesco , Zanghi Didier , Brun Jean-François , Brassamin Séverine , Saboungi Marie-Louise , Price David L. 
Published: October 2007

AbstractAerodynamic levitation is a simple way to suspend samples which can be heated with CO2lasers. The advantages of this technique are the simplicity and compactness of the device, making it possible to integrate the device easily into different kinds of experiments. In addition, all types of sample can be used, including metals and oxides. The integration of this technique at synchrotron and neutron sources provides powerful tools to study molten materials.
Osteoblasts Express NLRP3, a Nucleotide-Binding Domain and Leucine-Rich Repeat Region Containing Receptor Implicated in Bacterially Induced Cell Death
Authors: McCall Samuel H , Sahraei Mahnaz , Young Amy B , Worley Charles S , Duncan Joseph A , Ting Jenny Pan-Yun , Marriott Ian 
Published: October 2007

Abstract
Bacterially induced osteoblast apoptosis may be a major contributor to bone loss during osteomyelitis. We provide evidence for the functional expression in osteoblasts of NLRP3, a member of the NLR family of cytosolic receptors that has been implicated in the initiation of programmed cell death.
Introduction: Osteoblasts undergo apoptosis after exposure to intracellular bacterial pathogens commonly associated with osteomyelitis. Death of this bone-forming cell type, in conjunction with increased numbers and activity of osteoclasts, may underlie the destruction of bone tissue at sites of bacterial infection. To date, the mechanisms responsible for bacterially induced apoptotic osteoblast cell death have not been resolved.
Materials and Methods: We used flow cytometric techniques to determine whether intracellular invasion is needed for maximal apoptotic cell death in primary osteoblasts after challenge with Salmonella enterica. In addition, we used real-time PCR and immunoblot analyses to assess osteoblast expression of members of the nucleotide-binding domain leucine-rich repeat region-containing family of intracellular receptors (NLRs) that have been predicted to be involved in the induction of programmed cell death. Furthermore, we have used co-immunoprecipitation and siRNA techniques to confirm the functionality of such sensors in this cell type.
Results: In this study, we showed that invasion of osteoblasts by Salmonella is necessary for maximal induction of apoptosis. We showed that murine and human osteoblasts express NLRP3 (previously known as CIAS1, cryopyrin, PYPAF1, or NALP3) but not NLRC4 (IPAF) and showed that the level of expression of this cytosolic receptor is modulated after bacterial challenge. We showed that osteoblasts express ASC, an adaptor molecule for NLRP3, and that these molecules associate after Salmonella infection. In addition, we showed that a reduction in the expression of NLRP3 attenuates Salmonella-induced reductions in the activity of an anti-apoptotic transcription factor in osteoblasts. Furthermore, we showed that NLRP3 expression is needed for caspase-1 activation and maximal induction of apoptosis in osteoblasts after infection with Salmonella.
Conclusions: The functional expression of NLRP3 in osteoblasts provides a potential mechanism underlying apoptotic cell death of this cell type after challenge with intracellular bacterial pathogens and may be a significant contributory factor to bone loss at sites of infection.
Serum 25-Hydroxyvitamin D and Hip Fracture Risk in Older U.S. White Adults
Authors: Looker Anne C , Mussolino Michael E 
Published: October 2007

Abstract
We used serum 25(OH)D data from NHANES III and incident hip fracture cases identified using linked mortality and Medicare records, and found that serum 25(OH)D was significantly related to reduced hip fracture risk in non-Hispanic white adults ≥65 yr of age.
Introduction: The role of vitamin D status in reducing fracture risk is unclear. We examined the relationship between serum 25 hydroxyvitamin D [25(OH)D] and incident hip fracture risk in older non-Hispanic white adults.
Materials and Methods: The study sample consisted of 1917 white men and women ≥65 yr of age who were examined in the third National Health and Nutrition Examination Survey (NHANES III, 1988-1994), a nationally representative survey. Incident hip fractures were ascertained using linked mortality and Medicare records that were obtained for NHANES III participants. Serum 25(OH)D values were measured with a radioimmunoassay kit. Cox proportional hazards models were used to estimate the relative risk (RR) of hip fracture by serum 25(OH)D level.
Results: There were 156 incident hip fracture cases in the sample. Cases were older, had lower BMD and body mass index, more prevalent spine or wrist fractures and weight loss before baseline, and ate fewer kilocalories and less calcium than noncases. After adjusting for these differences, serum 25(OH)D values exceeding 60 nM were significantly related to hip fracture risk. For example, the multivariate-adjusted RR was 0.64 (95% CI, 0.46-0.89) among individuals with serum 25(OH)D values ≥62.5 nM compared with those with values below this level. When grouped into quartiles, the multivariate-adjusted RR for the second, third, and fourth versus the first quartile of serum 25(OH)D were 0.50 (95% CI, 0.25-1.00), 0.41 (95% CI, 0.24-0.70), and 0.50 (95% CI, 0.29-0.86), respectively.
Conclusions: Serum 25(OH)D was related to a significantly lower hip fracture risk in this cohort of older white adults, even after adjusting for several relevant confounding variables. The relationship did not seem to be linear across all values. Our results support other studies suggesting that serum 25(OH)D values exceeding 60 nM are associated with health benefits.
Assessing Population Risk for Postmenopausal Osteoporosis: A New Strategy Using Data From the Behavioral Risk Factor Surveillance System (BRFSS)
Authors: Schneyer Christine R , Lopez Helio , Concannon Mary , Hochberg Marc C 
Published: October 2007

Abstract
Osteoporosis public health measures are hindered by the inability to easily identify subclinical disease. We have now estimated state-specific osteoporosis prevalences using a simple formula (OST Index) to analyze age and weight of 62,882 older women; the prevalences determined are similar to those based on BMD. This new method has potential use for guiding implementation of osteoporosis prevention/treatment programs.
Introduction: Although osteoporosis-related fractures are a major U.S. public health issue, population-based prevention programs have not yet been developed. One contributing factor has been lack of a suitable screening test to detect asymptomatic high-risk individuals.
Materials and Methods: We estimated state-specific prevalences of postmenopausal osteoporosis using the Osteoporosis Self-Assessment Tool Index (OST Index; [self-reported weight in kg - age] × 0.2) to analyze data from 62,882 women ≥50 yr of age who participated in the 2002 Behavioral Risk Factor Surveillance System (BRFSS). The OST Index, designed to assess an individual's risk of disease, has previously been shown to have modest positive and high negative predictive value for osteoporosis defined by BMD criteria. Based on this index, women from each state were distributed among high-, moderate-, and low-risk OST categories. Calculated percentages for each category were weighted to U.S. Census Bureau population projections for 2002. By adjusting results to reflect previously validated percentages of women with osteoporosis in each risk category, we estimated the prevalence of postmenopausal osteoporosis in each state.
Results: Our calculated weighted prevalence estimates agreed closely with those of the National Osteoporosis Foundation derived from actual femoral neck BMD measurements obtained in the third National Health and Nutrition Examination Survey (1988-1994) and projected to U.S. census state population predictions for 2002. Comparison of unweighted BRFSS-OST results and NHANES BMD data revealed similar percentages of osteoporosis among all women ≥50 yr of age (BRFSS, 18.5%; NHANES, 18.0%; p = 0.47) and also among white women (BRFSS, 19.0%; NHANES, 20.0%; p = 0.28). However, the percentages of osteoporosis among blacks and Hispanics did not correspond, at least partly because of the lack of race-specific reference standards for BMD measurements and OST index ranges.
Conclusions: Analysis of readily available BRFSS data with the OST index formula is a simple, no-cost technique that provides state prevalence estimates of postmenopausal osteoporosis that could be used to guide allocation of resources to statewide osteoporosis prevention programs.