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This paper is devoted to the analysis of effects of the dimple geometry on the hydrodynamic characteristics of a tilting pad thrust bearing. In a first step a discretization of Reynolds equation has been carried out by the finite difference method. It is followed by the development and validation of a hydrodynamic model used later for the examination of the influence of different surface dimples (radial, circumferential, rectangular…) on the hydrodynamic characteristics such as maximum pressure, friction torque and power loss. This study allowed highlighting that a suitable arrangement of the dimple contact surface area and also the depth of the dimple can contribute significantly to the improvement of the hydrodynamic characteristics of the tilting-pad thrust bearing.

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This paper is consecrated to the thermodynamic study and analysis of diffusion-absorption-refrigeration (DAR) plants. The mass and energy balances analysis at the evaporator has allowed to highlight a new and original parameter, which can be used to analyze DAR system performances. It is the ratio of inert gas to refrigerant vapor mass flow rates at the evaporator inlets. This coefficient, which expression has been for the first time deduced mathematically, informs about the quality of the cycle and its performance, which are deeply affected by the growth of the inert gas flow energy expended to drive the refrigerant through the evaporator. The study shows that the coefficient of performance is decreasing with the increase of the mass flow rates ratio. The latter can be also used to find the optimal operating mode for the DAR machine with a specified working fluid.