On the Theory of Bin Loads

1969 ◽  
Vol 91 (2) ◽  
pp. 339-344 ◽  
Author(s):  
A. W. Jenike ◽  
J. R. Johanson
Keyword(s):  
Flow Pattern ◽  
Loading Conditions ◽  
Bulk Solid ◽  
Initial Loading ◽  
Vertical Part ◽  
Concentrated Forces

It is proposed that three loading conditions should be considered in the analysis of loads acting on a bin: Initial loading which occurs when bulk solid is charged without any of it being withdrawn, flow loading which occurs after flow has been established, and switch loading which occurs during the switch from initial to flow loading. The last is transient but, while it acts, it exerts large concentrated forces. The importance of the flow pattern is outlined and an expression is given for the high local force which frequently acts at the transition from the vertical part to the converging part of a bin.

ADAPTATION TO SUCROSE LOADING IN THE RAT

1966 ◽  
Vol 44 (3) ◽  
pp. 389-400
Author(s):  
Vincent Fiorica ◽  
P. F. Iampietro ◽  
Russell Moses
Keyword(s):  
Body Weight ◽  
Antidiuretic Hormone ◽  
Water Conservation ◽  
Physiological Adaptation ◽  
Loading Conditions ◽  
Adaptive Responses ◽  
Arterial Infusion ◽  
Initial Loading ◽  
Sucrose Solutions ◽  
Sucrose Loading

Four groups of unanesthetized rats were infused with standardized volumes of 1.46 M (50% w/v) sucrose solutions through chronically indwelling arterial catheters. The excretion of water and solutes was measured during the following 6 hours. Five days later, after the animals had returned to their pre-loading weights, each group was infused again with the same load given initially. After the second loading, a pattern of excretion of water and solutes was observed which was different from that elicited by the first loading. The adaptations manifested after a second loading were characterized principally by (a) a smaller total volume excretion of urine (milliliters per 100 g body weight), (b) the excretion of a smaller fraction of the infused load, (c) an earlier inhibition of the initial diuresis, and (d) the production of a more concentrated urine. It is suggested that the initial loading conditions generate a physiological adaptation which promotes the water conservation mechanisms of the animal. This may involve a greater sensitivity of the adapted animal to antidiuretic hormone. It was further observed that the characteristics of the adaptations generated by intra-arterial infusion are qualitatively different from those produced by intraperitoneal infusion. This suggests that the ability of hypertonic solutions to evoke adaptive responses is dependent on the route through which such solutions are given.

scholarly journals Permeability of the Hydrated Shale under Cyclic Loading and Unloading Conditions

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Liu Xianshan ◽  
Li Man ◽  
Xu Ming ◽  
Kang Zhiyong
Keyword(s):  
Cyclic Loading ◽  
Confining Pressure ◽  
Loading Conditions ◽  
Permeability Evolution ◽  
Loading Process ◽  
Cyclic Loading And Unloading ◽  
Initial Loading ◽  
Cyclic Processes ◽  
Loading And Unloading ◽  
Shale Permeability

The hydrated shales under cyclic loading and unloading conditions are common for the shale reservoir development; corresponding mechanical properties and permeability evolution are very significant and should be deeply researched. Firstly, the experiments of the hydrated shales under the above conditions are discussed, showing that the peak strength is lower and corresponding permeability is higher for more days of hydrating treatment. Secondly, the damage theory is proposed to analyze the shale permeability evolution due to hydromechanical damage and get permeability variation under initial loading and unloading conditions, observing that the permeability in the loading process decreases with increasing confining pressure and increases in the unloading process with decreasing confining pressure; however, the former changes much greater than the latter considering the same confining pressure, indicating that the irreversible damage for the hydrated shales in this cyclic condition has resulted in obvious difference of the permeability. Furthermore, the curves between the permeability and confining pressure based on the experimental data are fitted as negative exponential functions under initial loading conditions and power functions under more cyclic loading conditions, showing that more loading process will change the permeability evolution model. However, the permeability while unloading changes smoothly and can be fitted as a power function with the confining pressure. And in addition, the loss ratio and recovery ratio of the permeability have been deeply researched under five cyclic loading and unloading conditions, thoroughly explaining the permeability decreasing variation with more cyclic processes. Finally, the sensitive coefficients of the permeability have been investigated to observe the largest coefficients under initial cyclic conditions and less and less with more cyclic processes, especially the coefficients while loading which are more sensitive to lower confining pressure and smaller while unloading, which is in accordance with the shale permeability loss and recovery variation, revealing the permeability evolution of the hydrated shale under complex extracted environment.

Fractional derivative modeling of time-varying viscosity materials considering initial loading ramp in real experiments

2021 ◽  
pp. 108128652199523
Author(s):  
Teng Su ◽  
Hongwei Zhou ◽  
Jiawei Zhao ◽  
Daniel Dias
Keyword(s):  
Fractional Derivative ◽  
Superposition Principle ◽  
Maxwell Model ◽  
Step Function ◽  
Parameter Determination ◽  
Time Varying ◽  
Loading Conditions ◽  
Experimental Time ◽  
Initial Loading ◽  
Varying Viscosity

The fractional derivative models with time-varying viscosity have been used in characterizing creep or relaxation properties of different viscoelastic material, and many combination models were presented using the Boltzmann superposition principle. However, those models defined as initial ones in this manuscript usually ignored the initial loading ramp, and the ideal-loading condition is commonly assumed as a step function in modeling. The real-loading conditions of tested samples are usually a ramp load followed by constant stress or strain. The difference in loading conditions between the theoretical modeling and experimental procedure strongly influences the models’ rheological property characterization and parameter determination. It is especially the case for the fractional derivative model due to its memory or history-dependent characters, even though the ramp time is short compared with the total experimental time. An application example of the Maxwell model with time-varying viscosity Scott–Blair model (TVSM) shows that the initial loading ramp has a strong influence. To solve this problem, the authors propose modified models of TVSM based on real-loading conditions. The relative errors between initial and modified models are presented. In addition, a history-dependent optimization algorithm for parameter determination is proposed. Three sets of polymer experimental data are employed to suggest that the fitting results of models disregarding initial ramp loads are unreliable. The modified model should be used for characterizing rheological behavior, as this leads to obtaining the best fitting results even for a short experimental time.

Flow Configure in Vertical 180 Degree Turning Duct

2001 ◽  
Author(s):  
Lu Yuanwei ◽  
Zhou Fangde ◽  
Wang Yueshe ◽  
Qian Huanqun ◽  
Hu Zhihua
Keyword(s):  
Flow Pattern ◽  
Liquid Flow ◽  
Two Phase Flow ◽  
Vertical Tube ◽  
Experimental Result ◽  
Phase Flow ◽  
Two Phase ◽  
Vertical Part ◽  
Flow Situation ◽  
Gas Liquid Flow

Abstract Bend is applied in many industries, which exert an influence on fluid and make the flow complicate. The second flow caused by the bend is strong enough that the flow behind it very long can be affected, so it is hard to make the flow in it steady. The long-term unsteady flow can make the pipe fatigue, so make the tube crack and leak. It is important to improve this situation. In this paper a throttle is built in the exit of the bend to control the non-homogeneous flow inside the bend, which can overcome the disadvantage of bend in industrial application. Through computed the flow field behind the bend by water, we can see that the throttle can improve the flow situation and make the flow steady behind it. Applying this method to the gas-liquid flow, the experimental result showed that the void fraction behind the bend is alike the fully developed flow. It means that the throttle can improve the two-phase flow situation in the invert U bend. At last the gas-liquid flow pattern in-bend was studied by experiment and built the flow pattern map in the vertical parts of the invert U bend. It was found that the flow pattern in the vertical part of invert U bend is different from the fully developed gas-liquid flow in vertical tube. The throttle built in the bend make the unsteady region of two-phase flow being reduced.

Morphology and development of flow-pattern defect with extended nonagitated Secco etching

1994 ◽  
Vol 52 ◽  
pp. 868-869
Author(s):  
Y. Pan
Keyword(s):  
Flow Pattern ◽  
Silicon Crystal ◽  
Gate Oxide ◽  
Crystal Growth Rate ◽  
Etch Depth ◽  
Force Microscopy ◽  
Etch Pit ◽  
Float Zone ◽  
Atomic Force ◽  
Multiple Step

The D defect, which causes the degradation of gate oxide integrities (GOI), can be revealed by Secco etching as flow pattern defect (FPD) in both float zone (FZ) and Czochralski (Cz) silicon crystal or as crystal originated particles (COP) by a multiple-step SC-1 cleaning process. By decreasing the crystal growth rate or high temperature annealing, the FPD density can be reduced, while the D defectsize increased. During the etching, the FPD surface density and etch pit size (FPD #1) increased withthe etch depth, while the wedge shaped contours do not change their positions and curvatures (FIG.l).In this paper, with atomic force microscopy (AFM), a simple model for FPD morphology by non-crystallographic preferential etching, such as Secco etching, was established.One sample wafer (FPD #2) was Secco etched with surface removed by 4 μm (FIG.2). The cross section view shows the FPD has a circular saucer pit and the wedge contours are actually the side surfaces of a terrace structure with very small slopes. Note that the scale in z direction is purposely enhanced in the AFM images. The pit dimensions are listed in TABLE 1.

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