Plane-Strain Shear Dislocation on a Leaky Plane in a Poroelastic Solid

2016 ◽  
Vol 84 (2) ◽  
Author(s):  
Yongjia Song ◽  
John W. Rudnicki
Keyword(s):  
Shear Stress ◽  
Pore Pressure ◽  
Plane Strain ◽  
Mass Flux ◽  
Fluid Mass ◽  
Rate Of Increase ◽  
Constant Resistance ◽  
The Difference ◽  
Sudden Introduction

Solutions for the stress and pore pressure p are derived due to sudden introduction of a plane strain shear dislocation on a leaky plane in a linear poroelastic, fluid-infiltrated solid. For a leaky plane, y=0, the fluid mass flux is proportional to the difference in pore pressure across the plane requiring that Δp=R∂p/∂y, where R is a constant resistance. For R=0 and R→∞, the expressions for the stress and pore pressure reduce to previous solutions for the limiting cases of a permeable or impermeable plane, respectively. Solutions for the pore pressure and shear stress on and near y=0 depend significantly on the ratio of x and R. For the leaky plane, the shear stress at y=0 initially increases from the undrained value, as it does from the impermeable plane, but the peak becomes less prominent as the distance x from the dislocation increases. The slope (∂σxy/∂t) at t=0 for the leaky plane is always equal to that of the impermeable plane for any large but finite x. In contrast, the slope ∂σxy/∂t for the permeable fault is negative at t=0. The pore pressure on y=0 initially increases as it does for the impermeable plane and then decays to zero, but as for the shear stress, the increase becomes less with increasing distance x from the dislocation. The rate of increase at t=0 is equal to that for the impermeable fault.

Plane Strain Dislocations in Linear Elastic Diffusive Solids

1987 ◽  
Vol 54 (3) ◽  
pp. 545-552 ◽  
Author(s):  
J. W. Rudnicki
Keyword(s):  
Pore Pressure ◽  
Plane Strain ◽  
Fluid Pressure ◽  
Linear Elastic ◽  
Time Value ◽  
Long Time ◽  
Fourier And Laplace Transforms ◽  
The Difference ◽  
Short Time ◽  
Sudden Introduction

Solutions are obtained for the stress and pore pressure due to sudden introduction of plane strain dislocations in a linear elastic, fluid-infiltrated, Biot, solid. Previous solutions have required that the pore fluid pressure and its gradient be continuous. Consequently, the antisymmetry (symmetry) of the pore pressure p about y = 0 requires that this plane be permeable (p = 0) for a shear dislocation and impermeable (∂p/∂y = 0) for an opening dislocation. Here Fourier and Laplace transforms are used to obtain the stress and pore pressure due to sudden introduction of a shear dislocation on an impermeable plane and an opening dislocation on a permeable plane. The pore pressure is discontinuous on y = 0 for the shear dislocation and its gradient is discontinuous on y = 0 for the opening dislocation. The time-dependence of the traction induced on y = 0 is identical for shear and opening dislocations on an impermeable plane, but differs significantly from that for dislocations on a permeable plane. More specifically, the traction on an impermeable plane does not decay monotonically from its short-time (undrained) value as it does on a permeable plane; instead, it first increases to a peak in excess of the short-time value by about 20 percent of the difference between the short and long time values. Differences also occur in the distribution of stresses and pore pressure depending on whether the dislocations are emplaced on permeable or impermeable planes.

scholarly journals Finite Pure Plane Strain Bending of Inhomogeneous Anisotropic Sheets

Symmetry ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Sergei Alexandrov ◽  
Elena Lyamina ◽  
Yeong-Maw Hwang
Keyword(s):  
Plane Strain ◽  
Yield Criterion ◽  
Large Strains ◽  
Rigid Plastic ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Starting Point ◽  
The Difference ◽  
Inside Radius ◽  
Elastic Unloading

The present paper concerns the general solution for finite plane strain pure bending of incompressible, orthotropic sheets. In contrast to available solutions, the new solution is valid for inhomogeneous distributions of plastic properties. The solution is semi-analytic. A numerical treatment is only necessary for solving transcendent equations and evaluating ordinary integrals. The solution’s starting point is a transformation between Eulerian and Lagrangian coordinates that is valid for a wide class of constitutive equations. The symmetric distribution relative to the center line of the sheet is separately treated where it is advantageous. It is shown that this type of symmetry simplifies the solution. Hill’s quadratic yield criterion is adopted. Both elastic/plastic and rigid/plastic solutions are derived. Elastic unloading is also considered, and it is shown that reverse plastic yielding occurs at a relatively large inside radius. An illustrative example uses real experimental data. The distribution of plastic properties is symmetric in this example. It is shown that the difference between the elastic/plastic and rigid/plastic solutions is negligible, except at the very beginning of the process. However, the rigid/plastic solution is much simpler and, therefore, can be recommended for practical use at large strains, including calculating the residual stresses.

Magnetocrystalline Anisotropy and Twinning Stress of 10M and 2M Martensites in Ni-Mn-Ga System

2006 ◽  
Vol 512 ◽  
pp. 195-200 ◽  
Author(s):  
Nariaki Okamoto ◽  
Takashi Fukuda ◽  
Tomoyuki Kakeshita ◽  
Tetsuya Takeuchi
Keyword(s):  
Magnetic Field ◽  
Shear Stress ◽  
Magnetocrystalline Anisotropy ◽  
Anisotropy Constant ◽  
The Other ◽  
Magnetic Shear ◽  
Maximum Value ◽  
Twinning Plane ◽  
Twinning Shear ◽  
The Difference

Ni2MnGa alloy with 10M martensite exhibits rearrangement of martensite variants (RMV) by magnetic field, but Ni2.14Mn0.92Ga0.94 with 2M martensite does not. In order to explain the difference, we measured uniaxial magnetocrystalline anisotropy constant Ku and the stress required for twinning plane movement τreq in these alloys. Concerning the former alloy, the maximum value of magnetic shear stress acting across twinning plane τmag, which is evaluated as |Ku| divided by twinning shear, becomes larger than τr eq. On the other hand, concerning the latter alloy, the maximum of τmag is only one-tenth of τreq at any temperature examined. Obviously, the relation, τmag> τr eq, is satisfied when RMV occurs by magnetic field and vice versa. In this martensite, the large twinning shear of 2M martensite is responsible for small τmag and large τreq.

Grazing behaviour and pattern of intake of dairy cows grazing kikuyu (Pennisetum clandestinum) grass pastures in relation to sward height and length of grazing session

2009 ◽  
Vol 49 (3) ◽  
pp. 233 ◽  
Author(s):  
R. C. Dobos ◽  
W. J. Fulkerson ◽  
K. Sinclair ◽  
G. N. Hinch
Keyword(s):  
Dairy Cows ◽  
Grazing Management ◽  
Feeding Strategies ◽  
Intake Rate ◽  
Pennisetum Clandestinum ◽  
Sward Height ◽  
Rate Of Increase ◽  
Grazing Period ◽  
The Difference ◽  
Strip Grazing

To investigate how grazing time, herbage dry matter intake (DMI) and intake rate (IR) are influenced by intensive grazing management, dairy cows strip-grazing subtropical grass pastures (Pennisetum clandestinum) at two compressed sward heights (10 and 13 cm) and at five grazing durations (1, 2, 4, 8 and 15 h) and replicated over 3 days were studied. The study was conducted in summer and the cows were observed every 20 min from 1600 to 0700 hours to calculate the time spent (min/h) grazing, ruminating and resting. Total time spent grazing was 45 min longer for cows grazing the 13-cm sward than for those grazing the 10-cm sward over the 15-h grazing period. The rate of increase in grazing time was 0.64 h/h grazing duration up to 4 h after introduction to fresh pasture. IR of cows grazing the 13-cm sward was significantly higher than those grazing the 10-cm sward (0.17 v. 0.12 kg DM/min spent grazing). The difference in IRs between sward height treatments resulted from the higher DMI in the 13-cm sward within the first 4 h of grazing compared with the 10-cm sward, although following the first 4-h grazing period IR was similar for both sward heights. Grazing time increased with sward height up to a maximum of 4 h after introduction to fresh pasture and had also maximised herbage DMI by this time. These results have important practical implications for dairy cow grazing management systems because they show that dairy managers could remove cows after 4 h with little compromise in production and will help in developing optimum supplementary feeding strategies when pasture availability limits DMI.

scholarly journals THU0236 EFFICACY AND SAFETY OF NON-MITOGENIC ANTICD3 ANTIBODY ADMINISTRATION IN THE TREATMENT OF LUPUS-PRONE MICE

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 345.1-345
Author(s):  
M. Morita ◽  
S. Masuyama ◽  
M. Mizui ◽  
Y. Isaka
Keyword(s):  
T Cells ◽  
Antibody Titer ◽  
Cell Function ◽  
Cell Subpopulation ◽  
Target Cells ◽  
Therapeutic Effects ◽  
Autoantibody Production ◽  
Rate Of Increase ◽  
Dsdna Antibody ◽  
The Difference

Background:Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease characterized by the production of autoantibody and systemic tissue damages including glomerulonephritis. Immune responses mediated by autoreactive T-cells, as well as by autoantibody, is involved in the development and progression of end-organ damages1. Biologic agents which manipulate T-cell function such as CTLA4-Ig and anti-CD40L have been revisited and tried to treat human SLE, however, both of them failed to demonstrate efficacy.A mouse specific anti-CD3ε mAb, clone 145-2C11 (2C11) is known to be immunosuppressive by down-modulation of TCR and depletion of T-cells2. Administration of Fc-deleted 145-2C11 F(ab’)2to lupus-prone mice was reported to reduce lymphadenopathy and prolong survival, but had no significant effect on anti-DNA antibody titer3. The mechanisms by which 2C11 ameliorates lupus are still unclear.In this study, we used non-mitogenic Fc-modified silent 145-2c11 (2C11S), which disables interaction between target cells and Fc receptor-bearing cells, abolishes antibody directed cytotoxicity, and has longer half-life than F(ab’)2. 2C11S is expected to exert its effect in safe and stable as compared with functional parent-2C11 (2C11P) antibody.Objectives:The purpose of our study is to clarify the difference between 2C11S and 2C11P and to examine their therapeutic effects against murine lupus-prone (NZB/W F1) mice.Methods:20 μg of 2C11P (absolute antibody), 2C11S (absolute antibody), or isotype control immunoglobulin G1 κ (IC)(BioLegend) were administered intraperitoneally to C57BL6 mice. The difference of their action on T-cells were evaluated in a time series from peripheral blood. Plasma cytokine levels were measured within 24 hours after antibody administration.In NZB/W F1 mice from weeks 10 or 20, 2C11P, 2C11S, and IC were administered (100 μg / week, 4 times, intraperitoneally). Plasma anti-dsDNA antibody titer, spleen and kidney blood cell subpopulation, and histology of renal tissue were evaluated before and/or after treatment.Results:Duration of reduced TCR expression in 2C11S group was approximately twice as long as that in 2C11P group, and the levels of plasma TNF-α was not increased in 2C11S group while significant increase was observed in 2C11P group (IC; mean 48.3 ± SD 16.7 pg/ml, 2C11S; 57.9 ± 6.12, 2C11P; 168 ± 50.6, IC VS 2C11S; p>0.99, IC VS 2C11P; p=0.03, ANOVA).In NZB/W F1 mice, the number of follicular helper T (Tfh) cells in spleen significantly decreased in 2C11S group (IC; median 9.0*104[interquartile range 8.5*104], 2C11S; 1.8*104[1.0*104], 2C11P; 1.0*105[9.4*104], IC VS 2C11S; p=0.03, IC VS 2C11P; p>0.99, Kruskal-Wallis). The number of germinal center B (GCB) cells in spleen also decreased in 2C11S group (IC; 1.2*105[1.7*105], 2C11S; 9.0*103[2.3*104], 2C11P; 8.0*104[2.3*105], IC VS 2C11S; p=0.03, IC VS 2C11P; p>0.99). The number of infiltrating CD4+T-cells in kidney significantly reduced in 2C11S group (IC; 3.4*103[1.0*104], 2C11S; 6.4*102[8.8*102], 2C11P; 1.2*103[4.4*103], IC VS 2C11S; p=0.048, IC VS 2C11P; p=0.23). In addition, the rate of increase in anti-dsDNA IgG titers significantly decreased in 2C11S group (IC; 2.3 [1.3], 2C11S; 0.9 [1.0], 2C11P; 1.3 [1.4], IC VS 2C11S; p=0.03, IC VS 2C11P; p=0.24). Finally, glomerular hypercellularity was markedly alleviated only in 2C11S group (IC; 4.4*10 [8.4], 2C11S; 3.8*10 [1.1], 2C11P; 3.9*10 [8.2], IC VS 2C11S; p=0.02, IC VS 2C11P; p=0.57).Conclusion:2C11S did not induce cytokine release with maintaining longer effect on TCR down-modulation. 2C11S reduced autoantibody production by suppressing GCB differentiation, possibly through down-regulation of Tfh cell number. Consequently, 2C11S ameliorated lupus nephritis. On the other hand, 2C11P did not show therapeutic effect.References:[1]George C Tsokos. et al. Nat. Rev. Rheum (2016) 12: 716-730.[2]Kuhn C. et al. Immunotherapy (2016) 8: 889-906.[3]Henrickson M. et al. Arthritis Rheum (1994) 37: 587-589.Disclosure of Interests: :None declared

Effects of Hole Pitch to Diameter Ratio P/D of Impingement and Film Hole on Laminated Cooling Effectiveness

2017 ◽  
Author(s):  
Weilun Zhou ◽  
Qinghua Deng ◽  
Wei He ◽  
Zhenping Feng
Keyword(s):  
Mass Flux ◽  
Pressure Loss ◽  
Pressure Ratio ◽  
Diameter Ratio ◽  
Hole Diameter ◽  
Heat Transfer Analysis ◽  
Internal Cooling ◽  
Cooling Effectiveness ◽  
System Pressure ◽  
The Difference

The laminated cooling, also known as impingement-effusion cooling, is believed to be a promising gas turbine blade cooling technique. In this paper, conjugate heat transfer analysis was employed to investigate the overall cooling effectiveness and total pressure loss of the laminated cooling configuration. The pitch to film hole diameter ratio P/Df of 3, 4, 5, 6, combined with pitch to impingement hole diameter ratio P/Di of 4, 6, 8, 10, are studied at the coolant mass flux G of 0.5, 1.0, 1.5, 2.0 kg/(sm2bar) respectively. The results show that overall cooling effectiveness of laminated cooling configuration increases with the decreasing of P/Df and the increasing of the coolant mass flux in general. However P/Df smaller than 3 may leads to a serious blocking in first few film holes at low coolant mass flux. The large P/Di that makes the Mach number of impingement flow greater than 0.16 may cause unacceptable pressure loss. The increment of overall cooling effectiveness depends on the difference between the deterioration of external cooling and the enhancement of internal cooling. Pressure loss increases exponentially with P/Di and G, and it increases more slowly with P/Df that compared to P/Di and G. The mixing loss takes up the most pressure loss at low coolant mass flux. With the increasing of the whole pressure loss, the proportion of throttling loss and laminated loss becomes larger and finally takes up the most of the whole pressure loss. When the sum of throttling loss and laminated loss is greater than mixing loss, the increment of system pressure ratio is unreasonable that compared to the increment of overall cooling effectiveness.

Flow Properties of Utah Shale Oils

1981 ◽  
Vol 21 (06) ◽  
pp. 679-686 ◽  
Author(s):  
W.H. Seitzer
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Pour Point ◽  
Water Solution ◽  
Shale Oil ◽  
Concentric Cylinder ◽  
Long Distance ◽  
Time Calibration ◽  
The Difference ◽  
Cylinder Viscometer

Abstract In a concentric cylinder viscometer. Utah shale oils have different characteristics, both at equilibrium flow and during start-up from rest, depending on whether the wax has crystallized as needles or spherulites. Compared with waxy crude oils, which are thixotropic, shale oil had the added rheological property of being antithixotropic. Introduction The most likely liquid synthetic fuel to be produced initially in the U.S. will be raw shale oil from western oil shale. This abundant resource is located principally in the western Rocky Mountain states of Colorado. Utah. and Wyoming (Fig. 1). Ultimate commercial production probably will be transported to marketing, distribution, and refining centers by pipeline. It has been reported that Utah shale oils produced by the Union "B" and Paraho DH retorting processes gave similar physical and chemical properties. Some properties of the two Utah shale oils are given in Table 1. The only major difference is that the Union shale oil has a pour point of - 1 degree C compared with a pour point of 25 degrees C for the Paraho oil. Wax Crystallization The difference in the pour points of the oils from the Utah shale retorted by Union Oil Co of California and Paraho is caused mainly by the difference in how the wax in the respective oils crystallizes. In the high- pour-point (25 degrees C) Paraho DK oil, the wax, under a microscope, appears as fine (1 to 10 m) needles, as expected for normal paraffins. However, the wax in the low-pour-point (−1 degrees C) Union oil forms small spherulites.Wax spherulites have not been reported before: however, this type of crystal is seen commonly in polymer. Spherulites show up as round areas containing a maltese cross when observed between crossed polars under a microscope.Photomicrographs of these crystals are shown in Figs. 2 and 3. The former, showing spherulites, is of the Union oil. In contrast, they are very different from the customary needles as typified by the Paraho oil in the latter micrograph. Presumably, these highly ordered spheres are made up of wax needles grown out radially from the center as described by Hartshorne and Stuart. The polarized light is scattered only by those needles not parallel nor perpendicular to the plane of polarization. Viscometer Measurements To understand the effect of these spherulites on the flow characteristics of raw shale oil at flow conditions expected in a long-distance pipeline, typical stress-rate measurements were made in a rotating cylinder viscometer, the Haake Rotovisco RV3 with MK500 measuring head and MVI coaxial cylinder sensor having an 82-mm cup and radii ratio of 0.95. This equipment has provisions for varying shear rate continuously at selected values down to 23.4 sec(−1)/min and can produce and record shear stress as a function of either shear rate or time. Calibration of the sensor was verified with a sucrose/water solution at several temperatures.Changes in temperature always were made from lower to higher to keep the sensor full of oil. Also, the shear-stress/ shear-rate curves were obtained by starting at high shear, down to zero, and then back up. SPEJ P. 679^

scholarly journals Shear stress activation of platelet glycoprotein IIb/IIIa plus von Willebrand factor causes aggregation: filter blockage and the long bleeding time in von Willebrand's disease

Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1354-1361 ◽  
Author(s):  
JR O'Brien ◽  
GP Salmon
Keyword(s):  
Shear Stress ◽  
Bleeding Time ◽  
Platelet Rich Plasma ◽  
Divalent Cations ◽  
Mean Transit Time ◽  
Platelet Glycoprotein ◽  
High Shear ◽  
The Difference ◽  
Von Willebrand’S Factor ◽  
Induced Aggregation

The article explores the finding that high shear alone applied to normal, native blood results in platelet aggregation. A filter with tortuous capillary-sized channels permits a study of the effect of shearing forces at different pressures. Native, heparinized, citrated and EDTA blood and platelet-rich plasma (PRP) were forced through the filter. Normal and von Willebrand's blood were studied, as were the effects of antibodies to platelet glycoproteins (GPr) and to von Willebrand's factor (vWf) and of “membrane-active” drugs. Normally, the filter blocked at 40 mmHg but not at 5 mmHg. Transmission electronmicroscopy of the filter at 40 mmHg showed blockage by platelet aggregates. Initially, the mean transit time through the filter was 8 milliseconds. Platelet retention in the filter occurred in two phases. From 0 to 3 seconds, only high-shear, vWf, and GPrIIb/IIIa were required. From 10 to 20 seconds, retention presumably involved these three attributes, but divalent cations were also essential. Only this phase was inhibited by some membrane-active drugs. ADP- and thrombin- induced aggregation requires GPrIIb/IIIaand fibrinogen. Shear-induced blocking of the filter by blood with a normal concentration of fibrinogen requires GPrIIb/IIIa and vWf. This indicates a different type of exposure of GPrIIb/IIIa. The long bleeding time in vW disease highlights the absolute requirement for vWf and emphasizes the difference in exposure of GPrIIb/IIIa induced by shear stress. Evidently, a process similar to that occurring in the filter is required in normal capillary hemostasis.

scholarly journals Features of body weight growth in meat breeds heifers

2016 ◽  
Vol 18 (2) ◽  
Author(s):  
R. S. Oseredchuk ◽  
N. P. Babik ◽  
V. V. Fedorovych ◽  
E. I. Fedorovych ◽  
V. R. Dutka
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Weight Changes ◽  
Body Weight Changes ◽  
Relative Growth ◽  
Weight Growth ◽  
Rate Of Increase ◽  
The Difference ◽  
Tension Increase ◽  
Better Than

The data on the dynamics of body weight changes, absolute and average daily gains, frequency rate of increase in body weight, relative growth rate and intensity of body weight growth of Limousine and Volyn Meat breeds heifers. Both studied breeds characterized by different body weight at different age periods. Newborn Limousine breed heifers are weighed 2,7 kg more (P < 0.05) than Volyn Meat breed heifers; at 3 months age the difference was 8.5 kg (P < 0.05) at 6 months – 14.6 kg, at 9 month – 20.8 kg (P < 0.05), at 12 months – 25,6 kg (P < 0.05), at 15–months – 31.9 (P<0,05), and at 18 months – 23.5 kg. Total and average daily gains in animals of both breeds were the highest for a period of 3 to 6 months of age. In the period from birth to 15 months of age preference for average daily gains were in Limousine, however, the difference was statistically significant only for the period of 0 – 3 months and amounted to 63,9 g (P < 0,05). From 15 to 18 months of age Limousine slightly conceded to Volyn Meat breeds on this parameter. In animals of both breeds magnification of body weight increased with age, but over the entire period (from birth to 18 months) this parameter in Volyn Meat heifers was 0.6 times better than Limousine heifers. The coefficients of relative intensity and tension increase of body weight in animals of both breeds were highest in the period from birth to 3 months of age. With age, these indicators declined. Mainly, the advantage was in Volyn meat breed heifers, but the difference was not statistically significant.

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