Soft, low-friction particles in silos show peculiar features during their discharge. The outflow velocity and the clogging probability both depend upon the momentary silo fill height, in sharp contrast to...

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We study the outflow dynamics and clogging phenomena of mixtures of soft, elastic low-friction spherical grains and hard frictional spheres of similar size in a quasi-two-dimensional (2D) silo with narrow...

Summary Horizontal and multibranch wells are likely to become the major means of modern exploitation strategies; inflow performances for these wells are needed. Because this paper considers the finite conductivity of a horizontal well, it establishes the inflow performance relationships (IPRs) for different branch configurations of horizontal wells. We find that the IPR of a horizontal well presents nonlinear characteristics and is similar to Vogel's equation, which has been used extensively and successfully for analyzing the IPR of a vertical well in a solution-gas-drive reservoir. Instead of the effect of a two-phase (oil and gas) flow in a reservoir described by Vogel's equation, the nonlinear characteristics of horizontal wells are mainly the result of pressure drops caused by friction, acceleration, and gravity along the horizontal wellbore. The nonlinearity coefficient presents the pressure drop along the major branch, and it is a function of major-wellbore length, major-wellbore diameter, oil viscosity, and relative roughness. Then, the horizontal-well IPR is used to study the performance of the pinnate-branch horizontal well and the radial-branch (horizontal lateral) well. The branch number, branch length, major-wellbore length, major-wellbore diameter, oil viscosity, and relative roughness are combined into grouped parameters to present the effect on the deliverability incremental ratio JH and the nonlinearity coefficient ratio Rv of the pinnate-branch horizontal well to the conventional horizontal well, which show regression relationships with the grouped parameters for pinnate-branch horizontal wells. In addition, another binomial relationship between the deliverability incremental ratio JV and the grouped parameter combined by branch number, branch length, and equivalent oil drainage diameter is obtained for radial-branch (horizontal lateral) wells. The new IPR also covers conventional horizontal wells and vertical wells (with no branch) because the deliverability incremental ratios JH and JV in both cases are unity. The IPR is very valuable for calculating the productivity of horizontal wells, pinnate-branch horizontal wells, and radial-branch wells.

Irregular meals (mainly the skipping of breakfast) and inadequate sleep has become prevalent in young people. However, there has been inadequate attention on the adverse effects of this nocturnal life. We observed the 24-hr patterns of sex hormones and other relative hormones in ten medical students, with the randomized cross-over design, on either a diurnal life or a nocturnal life. The subjects on a diurnal life ate three meals (07:00, 13:00 and 19:00) and slept from 22:30 to 06:30. Nocturnal life was designed by skipping their breakfast but consuming a lot (> 50% of their daily food intake) in the evening and at night, sleeping from 01:30 to 08:30 the next morning. After three weeks in the experimental life, the 24-hr plasma concentrations of testosterone, free testosterone, dihydrotestosterone (DHT), androstenedione, prolactin, estrone, luteinizing hormone, cortisol and sex hormone binding globulin (SHBG) were measured every three hours. Plasma free testosterone and prolactin decreased, but cortisol increased when subjects followed the nocturnal life. In the diurnal lifestyle group, circadian rhythms were observed in the androgens (testosterone, free testosterone, DHT, androstenedione), prolactin, cortisol and SHBG in the cosinor analysis; however, circadian rhythms were almost extinguished in the nocturnal lifestyle group. Since sex hormones play important roles in the normal physiological condition, the effects of these changes in hormone concentration and its circadian rhythm should be considered and studied intensively.