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A method to design hybrid hydrostatic!hydrodynamic journal bearings, with the criterion of optimized self-compensation under misaligning loads, is presented. An analysis considering laminar and turbulent flow of a Newtonian incompressible lubricant between the bearing and a misaligned shaft, with restricted lubricant supply to each recess, is discussed. The mathematical model considers the modified steady-state Reynolds lubrication equation, an exact function for the local bearing radial clearance with a misaligned shaft, the continuity integral-differential equations at the recess limits, and boundary conditions at the cavitation zone and outer limits. The finite-difference method was used, and a modular computer program was developed. The procedure follows a univariate search to determine the optimum size and position of recesses and therefore obtain the design with the maximum reactive moment under misaligning loads. A validation of the model was obtained comparing the results with experimental and calculated data from the literature. Results for a 4 + 4 LBP hybrid bearing design are presented. [ABSTRACT FROM AUTHOR]

Little data exist on the safety of H2-blockers during pregnancy. A computerized database of medications dispensed from 1998 to 2007 to all women registered in the 'Clalit' health maintenance organization, in the Southern District of Israel, was linked with computerized databases containing maternal and infant hospitalization records from the district hospital. The following confounders were controlled for: parity, maternal age, ethnic group, maternal diabetes, smoking, and peripartum fever. Also, therapeutic pregnancy termination data were analyzed. A total of 117 960 infants were born during the study period, 84 823 of them (72%) to women registered at Clalit; 1148 of the latter were exposed to H2-blockers during the first trimester of pregnancy. Exposure to H2-blockers was not associated with an increased risk for congenital malformations (adjusted odds ratio [OR] = 1.03, 95% confidence interval [CI]: 0.80-1.32); also, no such association was found when therapeutic pregnancy terminations were included in the analysis (adjusted OR = 1.17, 95% CI: 0.93-1.46). Exposure to H2-blockers was not associated with perinatal mortality, premature delivery, low birth weight, or low Apgar scores. [ABSTRACT FROM AUTHOR]

A procedure is proposed to obtain the steady state displacement solution to linear vibration problems with non-harmonic, periodic, continuous or discontinuous excitation for any finite number of degrees of freedom. The solution obtained is exact, in closed form and in a single equation. The procedure makes no use of any transform. Since the displacement solution is exact, it may be differentiated to obtain the exact velocity and the exact acceleration. An example of a quarter-vehicle suspension model is solved in detail. [ABSTRACT FROM AUTHOR]

A scheme is proposed for linking together into a single equation the equations and inequalities that make up a piecewise representation of a non-harmonic, periodic, continuous or discontinuous function. A method using this scheme is proposed in order to obtain, in closed form, the displacement response of linear vibration problems with piecewise-continuous forcing functions. Since the solution is exact, so are the derivatives, i.e. the velocity and acceleration responses. An example is presented. [ABSTRACT FROM AUTHOR]