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Squeeze-film action in lubrication is present in many mechanical components, such as bearings, squeeze-film dampers, piston pins, and piston rings, as well as in natural and artificial joints. These mechanical components experience both rotation and squeeze action. In this paper, an experimental and theoretical model is developed that takes into account the combination of rotational speed as well as squeeze-film action in journal bearings. The vertical bearings, such as those in vertical pumps, are considered as well as the horizontal bearings. The governing equation and boundary conditions are derived for this purpose. Both the classical hydrodynamic lubrication theory and the mass conservation cavitation algorithm are considered. A comparison of the results of a series of experimental measurements and theoretical prediction show that they are in reasonable agreement. Examples are provided to illustrate how the results can be used in practice. [ABSTRACT FROM AUTHOR]

The steady state thermal behaviour of hydrodynamic bearings can be characterized by two unique dimensionless temperature rise parameters k1 and k2. Using these parameters, the results of extensive thermohydrodynamic simulations can be generalized for design purposes. The objective of this paper is to develop appropriate expressions for rapid estimation of the maximum temperature and the effective temperature as well as the bearing performance parameters. A series of examples is provided, illustrating the utility of these expressions for thrust and journal bearing designs. [ABSTRACT FROM AUTHOR]

Examines a finite slider bearings with the Bingham rheological model. Inclusion of full consideration for thermal effects; Presentation of the full thermohydrodynamic solutions; Authentication of the published one-dimensional isoviscous solutions.

Experiments were carried out to study the heat transfer and pressure drop characteristics of convex-louver fin-and-tube heat exchangers. In all, 12 samples of heat exchangers, including nine convex-louver, a wavy fin, a louver-fin, and a plate-fin configuration were tested and compared in the present investigation. The effects of row number and fin pitch on the thermal-hydraulic characteristics of the convex-louver were also investigated. Results are presented as plots of Fanning friction factor f and Colburn j factor against Reynolds number based on tube collar diameters in the range of 400 to 8,000. The data were also compared to the louver, wavy, and plain fin geometries. It was found that the number of rows has a small effect on the Colburn j factor only at Reynolds numbers less than 1,000. Also, it is shown that the row effect on the friction factors is negligible. [ABSTRACT FROM PUBLISHER]

Determination of the fracture fatigue entropy (FFE) in materials requires a proper assessment of the intrinsic dissipation terms in the entropy production equation. In this paper, physical terms that contribute to internal friction and their implications on measuring FFE in metals are discussed. We show that internal friction is one of the terms in the intrinsic dissipation equation that cannot be neglected even for low-cycle fatigue tests (LCF). Relevant to measuring internal friction, we also introduce a technique to identify the fatigue limit of metals by measuring their damping value at different stress levels. Fatigue tests are performed to examine the validity of the proposed technique for two types of steels (SS 304 and SS 1018). By comparing our results with the available data in the literature, we find that the discrepancy is less than 10%. The temperature dependence of internal friction for SS304 specimens is also investigated. The result demonstrates a linear relationship and the existence of a peak. • Intrinsic dissipation terms for calculation of fracture fatigue entropy (FFE) are identified. • Internal friction plays an important role in evaluation of the intrinsic dissipation in cyclic fatigue. • A technique to identify the fatigue limit of metals by measuring their damping value at different stress levels is introduced. • Experimental measurements for SS 304 and SS 1018 are presented to validate the proposed approach. [ABSTRACT FROM AUTHOR]

Abstract: The aim of this study was to determine whether the implementation of the quantitative Epstein-Barr virus polymerase chain reaction (qEBV-PCR) test in 2003 decreased the incidence of posttransplant lymphoproliferative disease (PTLD) and PTLD-related mortality. Of the 128 children who underwent liver transplantation between January 1994 and May 2007, 110 (85.9%) survived. Patients were divided into pre (1994 to 2002; n = 86) and post (2003 to 2007; n = 42) EBV-PCR groups. There were no between-group differences in mean age, percentage of patients <12 months old, or seronegative for EBV. The incidence rates of primary EBV infection in the pre- and post-EBV-PCR groups were 14.0% and 33.3%, respectively (P < .05). In contrast, the pre- and post-EBV-PCR groups showed similar incidences of symptomatic EBV infection (31.3% vs 35.7%; P = .625) and PTLD (10.5% vs 9.5%; P = .869), but different survival rates (80.2% vs 97.6%; P < .001). Five of nine PTLD patients in the pre-EBV-PCR group died of PTLD, but there was no PTLD-related mortality in the post-EBV-PCR group, indicating that PTLD-related mortality decreased after qEBV-PCR monitoring. These findings suggested that frequent EBV viral load monitoring and subsequent modulation of immunosuppression can reduce PTLD and PTLD-related mortality among pediatric liver transplant patients. [Copyright &y& Elsevier]

Poster: Clinical track: Upper GI (oesophagus, stomach, pancreas, liver) PO-1066: Clinical results of stereotactic body radiotherapy for elderly hepatocellular carcinoma patients J.Y. Jang, J. Jung, J. Park, J.H. Kim, S.M. Yoon. [Extracted from the article]

A computational model is developed to assess the effect of wear on the performance of an engine bearing. The model takes into account the variation of the film thickness under dynamic loading due to the wear of the bearing surface and shaft misalignment. The model adopts the mass-conservative cavitation algorithm to account for cavitation. To consider the surface roughness, the average flow model for the hydrodynamic pressure and the Kogut and Etsion model for the elastic-plastic contact pressure are implemented. A method for assessment of wear over long-term operation of an engine bearing to avoid failure is provided. To gain insight, results of a series of simulations with illustrative examples are presented. The simulations shows that the contact pressure is much smaller than the hydrodynamic pressure. The wear is directly related to the contact pressure, i.e. the surface roughness and the film thickness. The film thickness tends to remain nearly the same regardless of the surface roughness due to the much small contact pressure. Therefore, a small reduction of the surface roughness on the bearing surface decreases wear considerably. • A mass-conservative computational model for prediction of wear in engine bearings is developed. • The model accounts for misalignment and surface asperity elastic and plastic deformation. • In highly-loaded perfectly aligned engine bearing, the maximum wear depth increases linearly in the axial direction. • In misaligned engine bearing, the maximum wear depth increases steeply due to the highly localized contact pressure. [ABSTRACT FROM AUTHOR]