bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Two-Component Mixed Friction Model for a Lubricated Line
Contact
Authors: Polycarpou A. A. , Soom A. 
Published: February 2008

Abstract
A two-component, two-dimensional friction model for a lubricated line contact, operating in boundary and mixed lubrication regimes, is developed. The friction is explicitly decomposed into the solid and the fluid shear components. The solid component is due to the asperity interactions and the fluid shear arises from the lubricant present at the interface. The friction model includes the sliding velocity, the instantaneous separation of the sliding bodies, normal to the sliding direction, the normal load and fluid properties. The model is based on unsteady friction experiments carried out under constant normal loads and time-varying sliding velocities. The model is applied to quasi-steady sliding, unsteady continuous and intermittent sliding, including sticking and momentary reversals of motion. In each case it becomes possible to track the instantaneous fluid shear and solid friction components.
Hardness of Thin-Film Media: Scratch Experiments and Finite Element
Simulations
Authors: Kral E. R. , Komvopoulos K. , Bogy D. B. 
Published: February 2008

Abstract
Experiments and finite element simulations are presented pertaining to the effective hardness and the mechanics of indentation and sliding contact on elastic-plastic layered media. Hardness measurements obtained from scratch experiments are presented for thin-film rigid disks with 30 nm carbon overcoats. Reproducible results are obtained for residual scratch depths greater than approximately 8 nm. A simple force balance model is used to calculate the effective hardness of the layered medium. Hardness values for the surface layer are calculated by fitting a relationship between the hardness, scratch geometry, and layer thickness to the experimental data. The experimental results are compared with three-dimensional finite element simulations of a rigid spherical indenter sliding over a half-space with a stiffer and harder surface layer. The finite element results are used to verify the hardness model applied to the experimental data and to provide insight into the observed experimental behavior in the context of the associated elastic-plastic deformation characteristics of the layered medium.
An Analysis of Powder Lubricated Slider Bearings
Authors: McKeague K. T. , Khonsari M. M. 
Published: February 2008

AbstractA theory for predicting the behavior of powder lubricated slider bearings based on the collisional characteristics of the grain particles and their interactions at the boundaries is presented. General boundary conditions that account for the effects of powder slippage are applied to the slider bearing configuration. Theoretical predictions are presented with comparison to published experimental measurements. An extensive parametric study is also conducted to illustrate the behavior of the flow and the response of the bearing's load-carrying capacity and friction factor to changes in various powder material and boundary parameters.
Thermohydrodynamic Design Charts for Tilting-Pad Journal
Bearings
Authors: Fillon M. , Khonsari M. 
Published: February 2008

Abstract
Design charts are presented which allow one to predict the maximum temperature and a realistic effective temperature of five-shoe tilting-pad bearings. The charts utilize two dimensionless parameters which characterize the temperature rise in the film based on the ISOADI boundary conditions. A number of examples are presented to illustrate the utility of the design chart where the results are compared to both experimental measurements and full THD simulations.
The Radial and Axial Stiffnesses of Tapered Roller Bearings Under
Combined Load
Authors: Zantopulos H. 
Published: February 2008

Abstract
Equations and their derivations for finding the radial and axial stiffnesses of a single-row tapered roller bearing, assuming a rigid shaft and housing, are given for any case of combined radial and axial loads. This method is extended to include the two-row bearing under certain conditions. Also presented are tables to facilitate these calculations.
Elastohydrodynamic Lubrication by Powder Slurries
Authors: Hua D. Y. , Khonsari M. M. 
Published: February 2008

Abstract
Thermoelastohydrodynamic analysis of a powder slurry containing a mixture of MoS2 particles and a carrier fluid is presented for a line-contact configuration. The constitutive equation of the slurry is a non-Newtonian formulation based on experimental data. The model includes provisions for elastic/plastic deformation of particles in the slurry. Through this deformation, particles are shown to contribute to the load-carrying capacity. The viscosity of the carrier fluid is shown to increase considerably as a result of adding a large amount of particles, thus appreciably affecting the EHL behavior of powder slurries. Performance results are presented for the pressure profile, film thickness, temperature distribution, and traction coefficient for a number of sliding/rolling ratios. The existence of particles in slurry is shown to give rise to a higher temperature field and tends to increase the traction coefficient compared to typical shear thinning fluids.
Stability of Ring-Stiffened Tubular Members Under External
Pressure
Authors: Karamanos S. A. , Tassoulas J. L. 
Published: February 2008

Abstract
This paper presents results of a rigorous nonlinear finite element technique for the stability analysis of ring-stiffened steel tubes under external pressure. Large deformation, plasticity, as well as residual stresses and imperfections, are taken into account. Both internal and external stiffeners are simulated. A study of various parameters which affect pressure capacity is summarized, along with a comparison with available experimental data.
A Stochastic Analysis for Multiple Supported MDOF Secondary
Systems
Authors: Saudy A. , Aziz T. , Ghobarah A. 
Published: February 2008

Abstract
A new stochastic analysis is developed to estimate the response of multiple supported mdof secondary systems to dynamic loading. In the proposed stochastic analysis, the effect of the dynamic interaction between the secondary and primary systems is included. An outline for the theoretical formulation of the proposed stochastic analysis is presented. The assumptions adopted in the formulation are discussed. The dynamic interaction is shown to comprise two effects: the effect of the interaction forces arising at the attachment points, and the effect of the changes in the primary system properties resulting from the attachment of the secondary system. In addition, numerical examples are provided to demonstrate the validity of the proposed analysis.
Deformation Plasticity Failure Assessment Diagram (DPFAD) for Materials With Non-Ramberg-Osgood Stress-Strain Curves
Authors: Bloom J. M. 
Published: February 2008

AbstractThis paper presents a brief history of the evolution of the Central Electricity Generating Board’s (CEGB) R-6 failure assessment diagram (FAD) procedure used in assessing defects in structural components. The reader is taken from the original CEGB R-6 FAD strip yield model to the deformation plastic failure assessment diagram (DPFAD), which is dependent on Ramberg-Osgood (R-O) materials to general stress-strain curves. An extension of the DPFAD approach is given which allows the use of material stress-strain data which do not follow the R-O equation such as stainless steel or carbon manganese steel. The validity of the new approach coined piecewise failure assessment diagram (PWFAD) is demonstrated through comparisons with the J-integral responses (expressed in terms of failure assessment diagram curves) for several cracked configurations of non-R-O materials. The examples were taken from both finite element and experimental results. The comparisons with these test cases demonstrate the accuracy of PWFAD. The use of PWFAD requires the availability of deformation plasticity J-integral solutions for several values of the strain-hardening exponent as well as uniaxial tensile stress-strain data at the temperature of interest. Lacking this information, the original R-O DPFAD approach using known engineering yield and ultimate strengths would give the best available approximation. However, it is strongly recommended that actual uniaxial tensile stress-strain data be used when available.
Axisymmetric Elastic-Plastic FE Analysis of Pressurized
Elbows
Authors: Boussaa Dj. , Dang Van K. , Labbé P. , Tang H. T. 
Published: February 2008

Abstract
A variational formulation for the pure in-plane bending problem of pressurized elbows with arbitrary cross section, written in the 3-D infinitesimal displacement continuum mechanics framework, and particularly appropriate when a refined elastic-plastic local response is needed (e.g., in the presence of ratcheting), is presented. The similarity between this problem and an axisymmetric analysis is underlined and turned to account to solve the former using existing FE routines devoted to the latter. Some applications are given to illustrate the potentialities of the model.
Preliminary Design of Tubular Composite Structures Using Netting
Theory and Composite Degradation Factors
Authors: Tew B. W. 
Published: February 2008

Abstract
Tubular products and process vessels built using fiber-reinforced composite materials provide significant advantages in applications that require corrosion resistance, high strength, and light weight. A design approach based on netting theory is presented which enables engineers to develop preliminary structural designs for these structures using composite materials. The integration of creep, cyclic loading, and environmental degradation factors into initial design calculations is also discussed and illustrated.
Multiaxial Stress Concentration in an Externally Pressurized Cylinder
With an External Circumferential Groove
Authors: Tipton S. M. , Hickey K. A. , Rawson M. S. , Sorem J. R. 
Published: February 2008

Abstract
A thick-walled cylindrical specimen containing an external circumferential groove was subjected to external pressure. To investigate the maximum pressure sustainable by the reduced wall thickness, strain gage measurements were taken during external pressurization tests. For comparison to experimental results, an elastic-plastic notch stress-strain analysis was conducted based on Neuber’s rule. The analysis utilized multiaxial elastic finite element results along with elastic-plastic tensile test data for the cylinder material. Based on experimental observations, it was necessary to supplement the approach with an additional relation between elastic and elastic-plastic multiaxial strains for the axisymmetric geometry under investigation. Assuming an invariant hoop to radial strain ratio rather than an invariant hoop to axial strain ratio provided better agreement with experimental results. It is demonstrated that the boundary conditions used to model the specimen had a substantial effect on the finite element results, even though the boundary was somewhat removed from the region of concentrated stress. Biaxial strain measurements are presented versus pressure over the elastic and into the plastic regime, and deformation plasticity theory was used to compute stress and radial strain components corresponding to measured strains. It is demonstrated that in order to apply a multiaxial Neuber’s rule to accurately estimate the elastic-plastic stress-strain response (using elastic stress concentration information and elastic-plastic material data), it is necessary to utilize an experimental observation that the ratio of the hoop to radial strain remains invariant from the elastic to the elastic-plastic regime. This differs from published assumptions about invariant hoop-to-axial strain ratios based on analysis of circumferentially grooved solid shafts. The predictions are accurate for moderate plastic strains, but correlation breaks down for bulk plastic deformation.
Biomarkers of cardiovascular disease risk in 40–65-year-old men performing recommended levels of physical activity, compared with sedentary men
Authors: Perkins G M , Owen A , Kearney E M , Swaine I L 
Published: February 2008

Objective:Both the UK Department of Health and the US Centers for Disease Control and Prevention have recommended at least 30 minutes of moderate-intensity physical activity on most days for health. Specific mention is made of beneficial effects upon blood lipids. The purpose of this study was to compare biomarkers of cardiovascular disease risk in men who perform physical activity in accordance with these recommendations with those who do not.Methods:128 healthy men, aged 40–65 years, were recruited. 61 were classified as active (performing at least the minimum recommended physical activity of ⩾4 metabolic equivalents (METs), for 6 months immediately before the study) and 67 as sedentary. Fasting blood was drawn for total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides, and apolipoproteins (Apo) A-1 and B. Low-density lipoprotein cholesterol (LDL-C) was estimated using the Friedewald equation.Results:The median (interquartile range) physical activity level was 7.0 (5.0–10.7) versus 1.0 (0–1.8) hour/week at ⩾4 METs (active versus sedentary; p<0.001). Apo A-1 was higher in the active men (p = 0.032). No significant differences were found for TC, HDL-C, LDL-C, TC:HDL-C, triglycerides, Apo B, or the Apo B:A-1 ratio.Conclusions:These findings suggest that physical activity performed according to the recommendations used in this study favourably influenced Apo A-1. The finding that cholesterol and triglycerides were not different in men achieving the recommended physical activity levels compared with sedentary men contradicts some of the claims made within the published recommendations. However, intervention studies are needed to clarify these preliminary findings.
The use of medication and nutritional supplements during FIFA World Cups 2002 and 2006
Authors: Tscholl P , Junge A , Dvorak J 
Published: February 2008

Objective:To examine medication use in male top-level football players prior to and during international tournaments.Design:Prospective survey.Material:2944 team physicians’ reports on players’ medication intake.Methods:Each team physician was asked to document all medication and nutritional supplements taken in the 72 h prior to each match.Results:A total of 10 384 substances were reported (1.8 substances/player/match); 4450 (42.9%) of these were medicinal and 5934 (57.1%) nutritional supplements. The medications prescribed most frequently were non-steroidal anti-inflammatory agents (n = 2092; 20.1%); more than half of the players took these at least once during a tournament and more than 10% prior to every match (156 out of 1472). β-2-Agonists were reported for 1.4% (n = 20) and inhaled corticosteroids for 1.6% (n = 23) of participating players. Injected corticosteroids were reported for 73 players.Conclusions:The high intake of medication in international football – especially of non-steroidal anti-inflammatory drugs – is alarming and should be addressed. The results raise questions as to whether the medication was taken solely for therapeutic reasons. In view of the potential side effects, more restrictive recommendations for sport need to be developed.
Molecular testing for somatic cancer mutations: a survey of current and future testing in UK laboratories
Authors: Wordsworth S , Papanicolas I , Buchanan J , Frayling I , Taylor J , Tomlinson I 
Published: February 2008

Background:Genetics clinical practice has paid limited attention to non-inherited aspects of cancer, namely mutations occurring during carcinogenesis. These somatic mutations are likely to be the primary determinants of cancer behaviour and treatment response, with a recent example being Her2/Neu gene status and response to Herceptin in breast cancer.Aim:To assess the feasibility of widespread testing of tumours by surveying UK histopathology and genetics laboratories.Methods:The questionnaire asked: which of the common cancers or other malignancies are routinely assessed; which molecular and cytogenetic methods are used; who orders and funds testing; what is the future demand for somatic testing; and what are the barriers to widespread testing?Results:Of 50 laboratories surveyed, 33 responded, 22 of which are currently using molecular tests. The survey shows that the most common tests are immunohistochemistry, fluorescence in-situ hybridisation and DNA testing of somatic mutations. Most laboratories predict testing will increase over the next 10 years, particularly for DNA testing using microarrays. Respondents perceived the main barriers to expanding molecular testing were a lack of laboratory funding and scientific evidence and testing not considered an NHS priority.Conclusion:These results provide important information for healthcare commissioners faced with managing demand for molecular testing of cancers.
A 32-country comparison of tobacco smoke derived particle levels in indoor public places
Authors: Hyland A , Travers M J , Dresler C , Higbee C , Cummings K M 
Published: February 2008

Objective:To compare tobacco smoke-derived particulate levels in transportation and hospitality venues with and without smoking in 32 countries using a standardised measurement protocol.Methods:The TSI SidePak AM510 Personal Aerosol Monitor was used to measure the concentration of particulate matter less than 2.5 microns in diameter (PM2.5) in 1822 bars, restaurants, retail outlets, airports and other workplaces in 32 geographically dispersed countries between 2003 and 2007.Results:Geometric mean PM2.5levels were highest in Syria (372 μg/m3), Romania (366 μg/m3) and Lebanon (346 μg/m3), while they were lowest in the three countries that have nationwide laws prohibiting smoking in indoor public places (Ireland at 22 μg/m3, Uruguay at 18 μg/m3 and New Zealand at 8 μg/m3). On average, the PM2.5levels in places where smoking was observed was 8.9 times greater (95 CI 8.0 to 10) than levels in places where smoking was not observed.Conclusions:Levels of indoor fine particle air pollution in places where smoking is observed are typically greater than levels that the World Health Organization and US Environmental Protection Agency have concluded are harmful to human health.
A difference that makes a difference: young adult smokers’ accounts of cigarette brands and package design
Authors: Scheffels J 
Published: February 2008

Objective:To explore young adult smokers’ construction of meaning and identity in accounts of cigarette brands and cigarette package design, and the processes by which positive associations with a brand may be reinforced and sustained.Methods:Qualitative in-depth interviews with 21 smokers aged 18–23 in Norway, where advertising for tobacco has been banned since 1975.Results:Cigarette brand and cigarette package design appear as an integrated part of young smokers’ constructions of smoker identities, enabling the communication of personal characteristics, social identity and positions in hierarchies of status.Conclusion:Through branding and package design tobacco companies appear to be able to promote their products in a country where advertising is banned, by means of similar principles that make advertising effective: by creating preferences, differentiation and identification.
An examination of trends in amount and type of cigarette advertising and sales promotions in California stores, 2002–2005
Authors: Feighery E C , Schleicher N C , Cruz T Boley , Unger J B 
Published: February 2008

Background:Cigarette companies spend more of their marketing dollars in stores than in any other venue. In 2005, they spent 88% of a total of $13.1 billion to advertise and promote product sales in stores.Aim:The purposes of this study were to identify how the amount and types of cigarette advertising and sales promotions have changed in stores in California between 2002 and 2005, and to assess neighbourhood influences on cigarette marketing in stores.Methods:Four observational assessments of cigarette advertising were conducted in approximately 600 California stores that sold cigarettes from 2002 to 2005. Trained observers collected data on the amount and type of cigarette advertising, including signs, product shelving and displays and functional items, and presence of sales promotions on these items. Longitudinal analyses were performed to estimate trends over time and identify correlates of change in the amount and type of tobacco advertising.Results:The mean number of cigarette advertisements per store increased over time from 22.7 to 24.9. The percentage of stores with at least one advert for a sales promotion increased from 68% to 80%. The amount of advertising and proportion of stores with sales promotions increased more rapidly in stores situated in neighbourhoods with a higher proportion of African–Americans.Conclusion:The results indicate increasing use of stores to market and promote cigarette sales. Further, these increases are disproportionately accelerating in neighbourhoods with more African–Americans. Legislative strategies should be pursued to control the marketing of tobacco products and promotional strategies used to reduce prices in stores.
Risk Factors and Neurological Consequences of Syncopes Induced by Internal Carotid Artery Angioplasty
Authors: Martinez-Fernandez Eva , Boza Garcia Fernando , Gonzalez-Marcos Jose R. , Gil-Peralta Alberto , Gonzalez Garcia Alejandro , Mayol Deya Antonio 
Published: February 2008

Background and Purpose—Syncope and carotid sinus reactions (CSR) occur frequently in patients undergoing carotid angioplasty (CA). We investigated risk factors and the neurological consequences of carotid sinus syncope induced by CA.Methods—We examined 359 consecutive patients. Patients underwent assessment of cerebrovascular reserve before CA and continuous electroencephalographical monitoring during the procedure. We examined the impact of vascular risk factors, cerebral hemodynamics, characteristics of plaque, and procedural modality on the incidence of CSR and syncope. The effect of syncopes on periprocedural complication rates was also investigated.Results—CSR and syncope occurred in 62.7% and 18.0% of the procedures, respectively. The occurrence of CSR during angioplasty was significantly associated with the appearance of syncope. The incidence of syncope was significantly higher in longer plaques located in the carotid bifurcation, in the presence of contralateral carotid stenosis, or when protection devices were used. Although TIA during CA was more common in syncopal patients, stroke or death rates were similar in the 2 groups.Conclusions—Syncope occurs more frequently in patients with long plaques proximal to the carotid bifurcation, but it does not increase the periprocedural complications rate.