TY - JOUR. T1 - Effect of thermocycling on shear bond strength of glass ionomer cements. AU - Ballal, Nidambur Vasudev. AU - Paulson, Liz. AU - Ginjupalli, Kishore. AU - Ozcan, Mutlu. PY - 2019/1/1. Y1 - 2019/1/1. N2 - To evaluate the effect of thermocycling on shear bond strength of Fuji IX glass ionomer cement and a novel glass ionomer cement (Ketac Universal) to dentin. A total of 40 extracted human molars were divided into 4 groups (n = 10). The occlusal surfaces were ground flat to expose dentin using diamond discs. Dentin surfaces were treated according to manufacturers instructions, and restorative materials were applied onto a plastic mold of 3mm height and 4mm diameter. The shear bond strength of Ketac Universal and conventional Fuji IX glass ionomer cements was evaluated after 24 h using Instron Universal Testing Machine at a crosshead speed of 0.5 mm/min before and after the specimens were subjected to thrmocycling. There was no statistical difference in the shear bond strength of ...

The aim of this study was to investigate the effect of preheating on microshear bond strength (MSBS) of silorane and methacrylate-based composite resins to human dentin. The teeth were randomly divided into three main groups: (1) composite resins were heated upto 68 degrees C; (2) cooled to 4 degrees C; and (3) control [room temperature (RT)]. Each group was then randomly subdivided into four subgroups according to adhesive system used [Solobond M (Voco), All Bond SE (Bisco), Clearfil SE Bond (CSE) (Kuraray), Silorane adhesive system (SAS) (3M ESPE)]. Resin composite cylinders were formed (0.9mm diameterx0.7mm length) and MSBS of each specimen was tested. The preheated groups exhibited the highest MSBS ( ...

Purpose: To determine the degree of conversion (DC), physicochemical properties, and microshear bond strength (mu SBS) of experimental self-adhesive resin cements (SARCs) to dentin and yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. Materials and Methods: Dual-curing cements were formulated with UDMA, HEMA, bis-GMA, and TEG-DMA as the organic matrix. 2MP (bis 2-(methacryloyloxy)-ethyl-phosphate) and GDMAP (1,3-glycerol dimethacrylate phosphate) were added to impart self-adhesive characteristics. A control group was formulated without self-etch methacrylates. Silanized particles were incorporated. Photoactivation was carried out using an LED light-curing unit (1200 mW/cm(2)) for 20 s. Infrared spectroscopy assessed the DC immediately and after 24 h. pH was analyzed in real time and recorded after 48 h. Water sorption (W-sp), water solubility (W-sl), and film thickness measurements followed ISO 4049. mu SBS of the cements to dentin and Y-TZP was evaluated immediately and after 3 ...

TY - JOUR. T1 - Influence of NaOCl deproteinization on shear bond strength in function of dentin depth. AU - Toledano, Manuel. AU - Perdigão, Jorge. AU - Osorio, Estrella. AU - Osorio, Raquel. PY - 2002/8/1. Y1 - 2002/8/1. N2 - Purpose: To determine the influence of NaOCl application on shear bond strengths (SBS) to superficial and deep dentin, using Prime & Bond 2.1. Materials and Methods: Superficial and deep dentin was exposed in 40 extracted third molars by sectioning the occlusal surface immediately under the enamel-dentin junction or close to the pulp chamber. After polishing the dentin disks (600-grit SiC), they were assigned to two groups: (1) 36% orthophosphoric acid for 15 seconds, or (2): 36% orthophosphoric acid for 15 seconds followed by 5% sodium hypochlorite (NaOCl) for 2 minutes. The dentin adhesive was applied as per manufacturers instructions, followed by TPH resin-based composite. The specimens were stored in water for 24 hours at 37°C and thermocycled x500 and SBS were ...

TY - JOUR. T1 - Shear bond strength of the Tenure Solution dentin bonding system.. AU - Barkmeier, Wayne W.. AU - Cooley, R. L.. PY - 1989/10. Y1 - 1989/10. N2 - A liquid solution of an oxalate bonding system containing NTG-GMA and PMDM has become commercially available. The bond strength of this oxalate adhesive (Tenure Solution) to dentin was determined by bonding composite resin cylinders to extracted teeth. The bond strengths obtained in this study are compared to the bond strengths obtained in earlier studies with the first and second generation oxalate adhesives whose components were supplied as powders and required mixing. The oxalate solutions developed significantly higher bond strengths than the original powder type systems.. AB - A liquid solution of an oxalate bonding system containing NTG-GMA and PMDM has become commercially available. The bond strength of this oxalate adhesive (Tenure Solution) to dentin was determined by bonding composite resin cylinders to extracted teeth. The ...

Laboratory triaxial tests were carried out to investigate the reinforcement mechanism, to study the characteristics of flax fiber-reinforced clay, and to discuss the effect on stress-strain relationship and shear strength parameters of flax fiber-reinforced clay in different flax fiber content and different confining pressure. Respectively, the ratio of fiber content to clay by weight is 0.2%, 0.4%, 0.6%, 0.8%, and 1.0%, and the confining pressure is 100 kPa, 200 kPa, and 300 kPa in triaxial test. The test results show that, the shear strength of flax fiber-reinforced clay is greater than that of pure clay. Compared with the pure clay, the shear strength of flax fiber-reinforced clay increased as the cohesion and friction increased; while the increase of the friction is relatively small, the increase of cohesion is large. The shear strength firstly increased and then reduced with the increase of flax fiber content. When the fiber content was 0.8&

Effects of Wheat Flour Dough’s Viscoelastic Level by Adding Glucose Oxidase on its Dynamic Shear Properties whatever the Strain Modes

The acute and chronic adaptation to changes in blood flow occur as a result of endothelium-dependent responses that regulate vascular tone and the organization of the blood vessel wall. Among the most rapid responses of vascular endothelial cells to changes in fluid shear stress are K+ channel activation,2 generation of inositol trisphosphate,3 an increase in [Ca2+]i,23 24 and changes in pHi.4 5 The present study shows that an abrupt decrease in fluid shear stress produces cytosolic alkalinization of vascular endothelial cells by affecting membrane ion transporters that contribute to pHi regulation. After a period of exposure to continuous fluid shear stress at 2.7 dyne/cm2, the abrupt reduction of fluid shear stress from 2.7 to 0.3 dyne/cm2 produced a bicarbonate-dependent increase in pHi of 0.27 pH unit, which was not affected by prior inhibition of the Na+-H+ exchanger alone. Recovery from an NH4Cl prepulse-induced acid load occurred more rapidly when fluid shear stress was abruptly reduced ...

The friction coefficient of thin polymer sheets under high loads can be accounted for by a simple extension of the adhesion theory of friction in which the pressure dependence of the shear strength...

A. N. James and A. L. Little write: Hossain and Ali have presented an interesting set of results obtained for an Obhor sabkha clay near Jedda, suggesting a tentative correlation between undrained shear strength (measured by a field vane test) and the M-value (number of blows for 0.3 m penetration) obtained using a Mackintosh probe. :Figures 2-4 of the paper show clearly that one of the difficulties in dealing with sabkha is the considerable scatter of results and the variation in the nature of the basic material comprising the sabkha.. In a previous paper, Hossain & Ali (1988) divided the upper 5 metres of the Obhor Sabkha into two main zones:. Zone I: a landward zone, predominantly clayey beneath a thin (c. 0.5 m) layer of loose sand;. Zone II: a seaward zone, predominantly sandy with a thin (c. 0.5 m) cemented sandy crust.. A small subzone, IIA, is described as clay over sandy sabkha. For the upper soft clay (at Zone I) they give liquid limits between 20% and 50 0.000000or the top crust ...

Objective: This study examined the shear bond strength of bonding agents to normal or fluoridated enamel following use of weak or strong acids to prepare enamel surfaces and after contamination with a measured amount of saliva at various stages of the bonding procedure. Method and materials: One hundred extracted human third molar teeth were randomly separated into 2 basic groups (normal or fluoridated teeth), then divided into 5 subgroups. Group A specimens were not contaminated. After etching, enamel surfaces were dry and clean. Group B was left with wet surfaces after etching. Group C specimens were contaminated with artificial saliva and then dried. Group D specimens were contaminated with artificial saliva, rinsed, and then dried. In group E, all enamel surfaces were left contaminated with saliva after the etching procedures (with maleic acid or phosphoric acids). Adhesive resins were applied to all enamel surfaces according to the manufacturer s instructions. The specimens were then ...

The structure and physiology of the endothelial cells that line the mammalian vasculature are greatly influenced by the shear stresses that are continuously imposed on them by blood flow. The most obvious structural responses of endothelium to shear stress are changes in cell shape and orientation; in areas of low or inconsistent shear stress in vivo, or when cells are maintained in static culture, endothelial cells assume a cuboidal, cobblestone morphology, whereas they elongate and align in the direction of flow when shear stress is moderate or high.1 2 These morphological changes are adaptive in that they reduce the spatial fluctuations in shear stress and the maximum shears to which the cells are exposed.3 Shape change of cells within monolayers probably necessitate changes in the interaction of individual cells with their neighbors at cell-cell junctions; however, changes in endothelial cell-cell contacts during responses to altered shear stress have not been examined. Endothelial cells ...

The purpose of this study was to compare different solutions for the storage of teeth and their influence on the enamel surface. The bond strength of bonded brackets on the enamel surface was determined by shear testing with an Instron measuring machine (feed rate 0.5 mm/min). Previously, these teeth had been stored in different solutions and their bond strengths were compared to the values of freshly extracted teeth. The statistical depiction was performed by means of descriptive and explorative data analysis. The analysis was carried out with the SPSS program. For group comparison purposes, the single-factor variance analysis (ANOVA) and the Post Hoc Test (Tukey HSD) were used. The level of significance was set at P < .05. The study showed that bond strength using formaldehyde fixation came closest to bond strength from freshly extracted teeth, so a formaldehyde solution should be used for storage. Only bond strength with teeth stored in thymol was significantly different (P = .02) from that ...

TY - JOUR. T1 - Chapter 7 Monitoring Oxidative Stress in Vascular Endothelial Cells in Response to Fluid Shear Stress. T2 - From Biochemical Analyses to Micro- and Nanotechnologies. AU - Rouhanizadeh, Mahsa. AU - Takabe, Wakako. AU - Ai, Lisong. AU - Yu, Hongyu. AU - Hsiai, Tzung. PY - 2008. Y1 - 2008. N2 - Hemodynamics, specifically, fluid shear stress, modulates the focal nature of atherosclerosis. Shear stress induces vascular oxidative stress via the activation of membrane-bound NADPH oxidases present in vascular smooth muscle cells, fibroblasts, and phagocytic mononuclear cells. Shear stress acting on the endothelial cells at arterial bifurcations or branching points regulates both NADPH oxidase and nitric oxide (NO) synthase activities. The former is considered a major source of oxygen-centered radicals (i.e., superoxide anion [O2· -]) that give rise to oxidative stress; the latter is a source of nitrogen-centered radicals (i.e., nitric oxide [NO]) that give rise to nitrative/nitrosative ...

Hernon Manufacturing Inc. is launching a two-component methacrylate adhesive under the brand name Fusionbond370. It is able to bond thermoplastics, metal, wood and composites and will be used for marine, automotive and construction applications. Apart from being able to bond dissimilar substrates, the adhesive is fatigue and impact-resistant and is able to tolerate exposure to salt spray while maintaining the integrity of bonds at temperatures ranging from -100 F to 250 F. Shear strength varies from 620 psi to 3,000 psi depending on substrate.. Palm Labs Adhesives is expanding its range of fluorescent Cyanoacrylate adhesives with Turbo Fuse 130 FY, an adhesive with a curing time of 24 hours at room temperature. When exposed to ultraviolet light, the adhesive glows yellow, allowing for easy inspection of bonds. It is able to bond plastics, metals, elastomers and wood with a shear strength of 3,000 psi at temperatures of -65F to 180F.. ...

In most organisms biological processes are partitioned, or phased to specific times over the day through interactions between external cycles of temperature (thermocycles) and light (photocycles), and the endogenous circadian clock. This orchestration of biological activities is achieved in part through an underlying transcriptional network. To understand how thermocycles, photocycles and the circadian clock interact to control time of day specific transcript abundance in Arabidopsis thaliana, we conducted four diurnal and three circadian two-day time courses using Affymetrix GeneChips (ATH1). All time courses were carried out with seven-day-old seedlings grown on agar plates under thermocycles (HC, hot/cold) and/or photocycles (LD, light/dark), or continuous conditions (LL, continuous light; DD, continuous dark, HH, continuous hot). Whole seedlings (50-100), including roots, stems and leaves were collected every four hours and frozen in liquid nitrogen. The four time courses interrogating the

Objectives: To investigate the efficacy of a new orthodontic bonding system that incorporates the primer solution in the adhesive. Materials and Methods: 90 anterior bovine teeth were divided in three groups: in Group I, brackets were bonded with Transbond XT system, in Group II with GC Ortho Connect which incorporates the primer in the adhesive, and in Group III, a single layer of primer was applied on the teeth before bonding the brackets with GC Ortho Connect. After a 24-hour latency period, Shear Bond Strength (SBS) and Adhesive Remnant Index (ARI) were measured. In cases with remnants left mainly on the bracket base, energy dispersive X-ray (EDX) spectrometry was performed in order to determine the presence of calcium particles. Selected cases were examined with Scanning Electron Microscopy (SEM) analysis and in nanometer scale with a confocal visible light microscope (μsurf revolver, NanoFocus AG, Germany). Results: The mean SBS values were 7.25 ± 0.58 MPa for Group I, 6.57 ± 0.50 MPa for Group

This paper presents novel approaches to address the complex issues associated with preservation, transportation, and tensile testing of the vegetation root samples needed for the enhancement of soil and prevent erosion. Readily availability of no equipment for in-situ assessment of the roots contribution to soil strength forces the researchers to transport the root samples to the lab for testing and estimating the contribution to the soil shear strength. Moreover, the standard procedures and apparatuses available in the public domain are regrettably suitable for testing of relatively stiffer materials. Therefore, conducting the tensile test of roots using off-the-shelf equipment often causes premature failure of the soft tissues and produces an erratic result, which ultimately leads to unrealistic soil shear strength. The experimental work replaced the traditional jaw type grips by innovative 3D-printed mold or metal ring with silicone, epoxy, and hot-glue to ensure a minimal degree of damage to the

Also constructions in soil can fail due to shear, e.g. the weight of an earth-filled dam or dike may cause the subsoil to collapse, like a small landslide. A simple definition of shear stress is, The components of stress at a point that act parallel to the plane in which they lie. Shear stress vectors have a important relevance on surfaces due to movement of fluids on it. When a fluid moves uppon a surface, there is generation of shear stress. Particularly, the laminar flux on the surface have a 0 m/s velocity, and the shear stress appears. The biological importance of shear stress relies on blood flux. The endothelial cells recognise them and tranduces signals to vascular muscular cells and others in order to modify the vessels structure. It is necessary, because high shear stress vessels regions must have larger vessels walls. ...

Engineering grain boundaries (GBs) are effective in tuning the thermoelectric (TE) properties of TE materials, but the role of GB on mechanical properties, which is important for their commercial applications, remains unexplored. In this paper, we apply ab initio method to examine the ideal shear strength and failure mechanism of GBs in TE oxide BiCuSeO. We find that the ideal shear strength of the GB is much lower than that of the ideal single crystal. The atomic rearrangements accommodating the lattice and neighbor structure mismatch between different grains leads to the much weaker GB stiffness compared with grains. Failure of the GBs arises from either the distortion of the Cu-Se layers or the relative slip between Bi-O and Cu-Se layers. This work is crucial to illustrate the deformation of GBs, laying the basis for the development and design of mechanically robust polycrystalline TE materials. ...

TY - JOUR. T1 - Effects of disturbed flow on endothelial cells. AU - Chiu, J. J.. AU - Wang, D. L.. AU - Usami, S.. AU - Chien, S.. AU - Skalak, R.. PY - 1998/2. Y1 - 1998/2. N2 - Atherosclerotic lesions tend to localize at curvatures and branches of the arterial system, where the local flow is often disturbed and irregular (e.g., flow separation, recirculation, complex flow patterns, and nonuniform shear stress distributions). The effects of such flow conditions on cultured human umbilical vein endothelial cells (HUVECs) were studied in vitro by using a vertical-step flow channel (VSF). Detailed shear stress distributions and flow structures have been computed by using the finite volume method in a general curvilinear coordinate system. HUVECs in the reattachment areas with low shear stresses were generally rounded in shape. In contrast, the cells under higher shear stresses were significantly elongated and aligned with the flow direction, even for those in the area with reversed flow. When ...

The mechanical properties and microstructure of articular cartilage from the canine tibial plateau were studied 12 weeks after total medial meniscectomy. The organization of the birefringent collagen network was measured with quantitative polarized light microscopy to determine the thickness and the degree of organization of the superficial and deep zones. The zonal concentration of sulfated glycosaminoglycan was quantified with digital densitometry of safranin-O staining. Equilibrium compressive and shear properties, as well as dynamic shear properties, were measured at sites adjacent to those of microstructural analysis. The results evinced significant loss of cartilage function following meniscectomy, with decreases of 20-50% in the compressive and shear moduli. There was no evidence of alterations in the degree of collagen fibrillar organization, although a complete loss of the surface zone was seen in 60% of the samples that underwent meniscectomy. Meniscectomy resulted in a decreased ...

Particles are frequently exposed to shear stresses during manufacturing, which leads to breakage. This is particularly relevant to weak active pharmaceutical ingredients and is prevalent in pharmaceutical and food industries. The attrition of Paracetamol and Aspirin caused by shear deformation at very low stresses is investigated here. The extent of breakage of these particles is related to the prevailing shear stresses and strains. In contrast to the expected trend, smaller particles exhibited increased breakage rates. At the onset of shearing at low stresses Aspirin particles experienced slightly more breakage than the Paracetamol, however prolonged shearing resulted in greater breakage of Paracetamol. Breakage occurred initially through chipping with some fragmentation, particularly more noticeable for Aspirin, with an increase in abrasion after extensive shear strain for Paracetamol. Empirical breakage relationships are proposed and when combined with process stresses and strain analyses the ...

This study investigated the influence of beam depth with varying longitudinal reinforcement without shear reinforcement. Size effect, which is described here in as the decrease in shear strength with the increase in the depth of members, is not evaluated sufficiently enough. To this end, fifteen palm kernel shell (PKS) reinforced concrete beams varying from 150 to 300 mm were tested to investigate their size effects on ultimate shear capacity and failure modes. Test variables were longitudinal reinforcement ratio (ρw varying from 1 to 2%) and effective depth of beams (varying from 120 to 265 mm) with average compressive strength (fcu) = 30.3 MPa and shear span to effective depth (av/d) = 2.5. For the range of variables tested, the test results were compared with the strengths predicted by the ACI 318-08 and BS 8110 with and without reduction factors. All tested beams failed in shear failure modes and were influenced by the beam depth and amount of longitudinal reinforcement. The PKS beams were

Resulcin Aqua Prime & Monobond N and AC-Bond were not significantly different than established 5th generation products. AC-Bond + Desensitizer and Prompt L-Pop have significantly different SBS from established 4th and 5th generation products. Future studies are required to investigate marginal i …

TY - JOUR. T1 - Local wall shear stress variations predicted by computational fluid dynamics for hygienic design. AU - Jensen, Bo Boye Busk. AU - Friis, Alan. AU - Benezech, Thierry. AU - Legentilhomme, Patrick. AU - Lelievre, Caroline. PY - 2005. Y1 - 2005. M3 - Journal article. VL - 83. SP - 53. EP - 60. JO - Food and Bioproducts Processing. JF - Food and Bioproducts Processing. SN - 0960-3085. IS - C1. ER - ...

The objective of this study was to determine the efficiency of an argon laser in polymerizing a light-cured orthodontic adhesive. Metal brackets were bonded to 185 premolars, divided into 5 different protocol groups of 37 each as follows: light 40-se

Previous studies have demonstrated that endothelial cells exposed to laminar shear stress are protected from apoptotic stimuli such as tumor necrosis factor (TNF)-alpha. The authors investigated the role of phosphatidylserine (PS) in this phenomenon. Western blot analysis of cleaved caspase 3 was used as an indicator of apoptosis and revealed that in the absence of serine, endothelial cells exposed to laminar shear stress were unable to protect against TNF-alpha-induced apoptosis, in contrast to sheared cells grown in regular medium. It was also found that shear-induced activation of the Akt pathway was significantly decreased in cells grown without serine. In addition, quantitation of PS using a novel isotopic labeling technique involving the use of formalin revealed that stearoyl-oleic PS (18:0/18:1) did not increase during shear treatment. These findings suggest that basal levels of PS are required to activate survival pathways in endothelial cells and thereby contribute to the overall ...

Hot-melt, pressure-sensitive adhesive compositions of amorphous polyalphaolefin and crystalline polypropylene have improved bond strength over the amorphous polyalphaolefin alone. The adhesive compositions improve dynamic shear strength, dynamic peel strength, as well as static peel strength. The adhesive compositions are particularly suitable for use in absorbent articles.

is converted to polymethacrylimide Rohacell 31 IG F Properties Metric English Comments Physical Properties Density 0 032 g cc 0 00116 lb in ASTM D 1622 63 Water Absorption 19 5 19 5 Equilibrium at 98 RH Moisture Absorption at Equilibrium 1 5 1 5 15 RH Moisture Absorption at Equilibrium 2 9 2 9 30 RH Moisture Absorption at Equilibrium 4 7 4 7 50 RH Moisture Absorption at Equilibrium 6 6 65 RH Water Absorption at Saturation 13 13 Volume 50 days immersion at 20fC Moisture Expansion Max 1 Max 1 50 days immersion at 20fC Mechanical Properties Tensile Strength Ultimate 0 979 MPa 142 psi ASTM D 638 68 Elongation break 3 5 3 5 ASTM D 638 68 Modulus of Elasticity 0 0353 GPa 5 12 ksi ASTM D 638 68 Flexural Yield Strength 0 786 MPa 114 psi ASTM D 790 66 Compressive Yield Strength 0 393 mpA 57 PSI ASTM D 790 66 Shear Modulus 0 0128 1 85 ksi ASTM C 273 61 Shear Modulus 0 0137 1 99ksi ASTM D 2236 69 Shear Strength 0 393 MPa 57 psi ASTM C 273 61 Electrical Properties Dielectric Constant 1 05 1 05 5 0 GHz ...

atherosclerosis is a leading cause of morbidity and mortality in developed countries and is shown to be an inflammatory disease (22, 28). Although multiple systemic factors such as hypercholesterolemia, diabetes, hypertension, and smoking are well-known risk factors, atherosclerosis occurs preferentially at particular areas of disturbed flow characterized by low and oscillatory wall shear stress (WSS) in branched or curved arteries (19, 34). In contrast, straight arterial regions are exposed to high and stable shear stress and are well protected from atherosclerosis (34). Despite the close association between the two, evidence directly linking disturbed flow conditions to atherosclerosis has been lacking, and the mechanisms responsible for pro- and antiatherogenic effects of shear stress are still incompletely understood.. Shear stress is the tangential force imparted by viscous fluid flowing over endothelial cells (5, 16). Endothelial cells sense changes in shear stress and trigger ...

The machine used is called a squaring shear, power shear, or guillotine. The machine may be foot powered, less commonly hand powered, or mechanically or hydraulically powered. It works by first clamping the material with a ram. A moving blade then comes down across a fixed blade to shear the material. For larger shears the moving blade may be set on an angle or rocked in order to shear the material progressively from one side to the other; this angle is referred to as the shear angle. Setting the blade on an angle decreases the amount of force required, but increases the stroke. A 5 degree shear angle decreases the force by about 20%. The amount of energy used is still the same. The moving blade may also be inclined 0.5 to 2.5°, called the rake angle, to keep the material from becoming wedged between the blades. However, raking the blade compromises the squareness of the edge.[4] The machine consists of a shear table, work-holding device, upper and lower blades, and a gauging device. The ...

We report high-resolution measurements of the forces between two atomically smooth solid surfaces across a film of 1-ethyl-3-methylimidazolium ethylsulfate ionic liquid, for film thickness down to a single ion diameter. For films thinner than ∼2 nm oscillatory structural forces are observed as the surface se

Arterioles that had been exposed to 17β-E2 overnight exhibited a significantly augmented dilation in response to increases in flow compared with control responses, as shown by the significant leftward shift in the slope of the flow-diameter curves (Figure 1⇑, top). These responses were not altered by incubation with 17α-E2 (Figure 4⇑, top), indicating a specific action of 17β-E2 on the vascular function. The physiological relevance of the enhanced flow-induced dilation is indicated further by the calculation of wall shear stress (Figure 1⇑, bottom). It shows a significant leftward shift of the shear stress-diameter curve after incubation with 17β-E2, revealing that the value of shear stress required to dilate arterioles maximally is significantly less than in control. These findings support the idea that in hypertension, impairment of the regulation of shear stress in arterioles, because of a lesser release of endothelial NO, may contribute to the elevated peripheral resistance.9 17 ...

The major finding of this study is the identification of a shear stress-induced p60src signaling pathway that regulates the transcriptional activation of TRE and SRE via MAPKs, including both JNK and ERK pathways. The src-family PTKs possess several structural features that include (1) an approximately 60-amino acid src homology 3 (SH3) domain that is involved in the interaction with signaling molecules that have proline-rich regions, (2) an approximately 100-amino acid src homology 2 (SH2) domain that can recognize the phosphorylated tyrosine of many RTKs, and (3) a kinase catalytic domain (see References 42 and 4342 43 for review). The activation of p60src by shear stress suggests that SH2- and SH3-containing molecules may be involved in the shear stress-induced signal transduction pathways and that RTKs may be upstream to such pathways. We have recently found that the Shc·Grb2·Sos ternary complex is involved in the endothelial gene expression in response to shear stress.44 Shc and Grb2 are ...

Evaluation Of The Effect Of Different Surface Treatments, Aging And Enzymatic Degradation On Zirconia-Resin Micro-Shear Bond Strength

Exact solutions for static bending of symmetric laminated orthotropic plates with different Lévy-type boundary conditions are developed. The shear deformation plate theories of Mindlin-Reissner and Reddy as well as the three-dimensional elasticity theory are employed. Using the minimum total potential energy principle, governing equilibrium equations of laminated orthotropic plates and pertaining boundary conditions are derived. Closed-form Lévy-type solutions are obtained for the governing equations of both theories using separation of variables method and different types of classical boundary conditions, namely simply-supported, clamped and free edge, are exactly satisfied. Thereafter, 3-D elasto-static equations for orthotropic materials are solved for bending analysis of laminated plates using two different approaches. First, the method of separation of variables is utilised and an exact closed-from solution is achieved for simply-supported laminated orthotropic plates. Next, a combined Fourier

Our 3M™ UV Light Detectable Ultra High Temperature Adhesive Transfer Tape 9085UV offers higher peel strength than most other acrylic formulations and exceptional shear strength even at elevated temperatures. The high performance and low outgassing adhesive system provides heat resistance in high temperature environment, including 540 °F (280 °C) in the short term.

Used to determine the physical and mechanical properties of raw materials and components, Lloyd Instruments manufactures and supplies universal testing machines (UTM) and tensile testers worldwide. The wide range of material testing machines can test for tensile strength, compression, flexure, friction, tear, peel, adhesion, shear, ductility, insertion, shear strength and many other parameters. Lloyd Instruments texture analyzers have an international reputation for their high performance and cost effectiveness. Specially engineered food texture probes provide the platform to perform rapid, general food testing and detailed texture analysis on a diverse range of foods.. DavenportTM Polymer Testing Products. Melt Flow Index (MFI): The Davenport Melt Flow Indexer is used to determine the melt flow properties of a polymer by extruding it in a molten state, through a calibrated die using a reference weight. It is used extensively in production and quality control to ensure batch-to-batch consistency ...

A laminated composite was produced using a thermoplastic prepreg by inserting an interleaved film with the same type of matrix as the prepreg during the lay-up process to improve the low interlaminar properties, which is a known weakness of laminated composites. Carbon fiber fabric (CFF) and polypropylene (PP) were used to manufacture the thermoplastic prepregs. Eight prepregs were used to produce the laminated composites. Interleaved films with different thicknesses were inserted into each prepreg. The physical properties of the composite, such as thickness, density, fiber volume fraction (Vf), and void content (Vc), were examined. The tensile strength, flexural strength, interlaminar shear strength (ILSS), impact property, and scanning electron microscopy (SEM) were used to characterize the mechanical properties. Compared to the composite without any inserted interleaved film, as the thickness of the inserted interleaved resin film was increased, Vc decreased by 51.45%. At the same time, however, the

An improved method is described for the fusing, joining or seaming of cellulosic materials. The method utilizes a solution of selected organometallic compounds or metal oxides to rapidly crosslink opposing, overlapping cellulosic surfaces to provide secure seams. Enhanced seam strength is achieved by a subsequent moisture treatment. The tubular cellulosic casings are well-suited for the manufacture of sausages and sausage-like products. The seams according to this invention have exceptionally high shear strength and wet strength.

Existing laboratory geo-mechanical data show that gas hydrates content can significantly increase the peak shear strength of hydrate bearing sediments while developing its strain softening. On the...

Price, G. J., Pastor, M. L., Towo, A. N., Ansell, M. P. and Packham, D. E., 2007. Shear strength at Sisal fibre-polyester resin interfaces: use of inverse gas chromatography to study pretreatment effects. Composite Interfaces ...

Dejong JT, Randolph MF, Degroot DJ, Yafrate N. 2011. Closure to Evaluation of remolded shear strength and sensitivity of full‐flow penetrometers. Journal of Geotechnical and Geoenvironmental Engineering. 137(4):440-441. ...

Yang B., Clouston PL, Arwade SR. 2014. Torsional shear strength and size effect in laminated veneer lumber. ASTM Advances in Civil Engineering Materials. 3(1):193-203. ...

In some HVAC applications, UL listings are critical for code compliance. This means the HVAC tape used has the proper adhesion and exceptional shear strength

Aim: To determine the viscoelastic properties of the porcine lens. Methods: Linear viscoelastic shear properties of the stroma of four porcine lenses were measured within 5 hours post-mortem, using sinusoidal oscillatory shear deformation. The elastic shear modulus, viscous shear modulus, dynamic viscosity, damping ratio, and phase shift of the lenses were quantified by a controlled-strain, linear simple-shear rheometer at frequencies of 10-50 Hz.. Results: The mean viscoelastic properties and their standard deviations across the frequencies examined were: the elastic shear modulus, G′ = 6.2±4.0 Pa, the viscous shear modulus, G″ = 19.2±2.5 Pa, the dynamic viscosity, η′ = 0.16±0.1 Pa•sec, the damping ratio ζ = 4.06±1.25, and the phase shift, δ = 76°± 5.6°.. Conclusions: The measured viscoelastic shear properties of the porcine lens reflect a low dynamic viscosity with a high damping ratio. The porcine lens is viscoelastic and is more viscous than elastic. The magnitude of the ...

TY - JOUR. T1 - Effects of dentin surface treatments on the shear bond strength of vitrabond. AU - Prati, C.. AU - Montanari, G.. AU - Biagini, G.. AU - Fava, F.. AU - Pashley, David Henry. PY - 1992/1/1. Y1 - 1992/1/1. N2 - The influences of nine dentin surface treatments were evaluated on the shear bond strength of a new light-cured glass-ionomer cement (GIC) and on the SEM morphology of the treated dentin surfaces. The following treatments were performed: saline solution (control), NaOCl, acidic glycine, EDTA, malic acid, malic acid plus glycine, polyacrylic acid, tannic acid, and neutral + acidic oxalate solutions. Buccal dentin surfaces were polished with #320-grit abrasive paper, treated with one of the chemicals, washed, and air-dried. Cylindrical GIC samples were then applied to the dentin surface, stored in 100% humidity, and tested after 24 h. SEM observations demonstrated no effect of saline or NaOCl treatment on the smear layer but its complete removal with exposure of collagen ...

The hydrofluoric acid (HF) is able to promote selective dissolution of the glassy phase in silica-based ceramic. However, the etching leaves insoluble silica-fluoride salts in the surface that affects negatively the bond, affirming the need of a post-etching cleaning. Evaluate the shear bond strength (SBS) of composite resin to CAD/CAM lithium-disilicate ceramics after different post-etching cleaning and silane treatments. Twenty-four 2 mm-thick slices of IPS e.max CAD (Ivoclar Vivadent, AG, Schann, Liechtenstein) were crystallized, embedded in acrylic resin, polished and cleaned in an ultrasonic bath. Each specimen was etched with 5% HF for 20 s, rinsed for 60 s, and treatment was completed using surface cleaning and silanization. The cleaning methods were: AW-air/water spray; UB-ultrasonic bath; PA-37% phosphoric acid; and ST-steam cleaning. The cleaned surface received: E-no silane treatment; E/S-silane application for 20 s, air drying for 20 s and hot drying (60 °C) for 20 s; E/S+-silane

In order to design civil structures that are supported by soils, the shear strength parameters of soils are required. Due to the large particle size of coarse-grained soils, large direct shear tests should be performed. In this study, large direct shear tests on three types of coarse grained soils (4.5 mm, 7.9 mm, and 15.9 mm) were performed to evaluate the effects of particle size on the shear behavior of coarse grained soils with/without geogrid reinforcements. Based on the direct shear test results, it was found that, in the case of no-reinforcement, the larger the maximum particle size became, the larger the friction angle was. Compared with the no-reinforcement case, the cases reinforced with either soft geogrid or stiff geogrid have smaller friction angles. The cohesion of the soil reinforced with stiff geogrid was larger than that of the soil reinforced with soft geogrid. The difference in the shear strength occurs because the case with a stiff geogrid has more soil to geogrid contact area,

Fluid shear stress is an important factor to consider when studying the behavior of endothelial cells in vascular system. The main focus of this study is to relate the spatial and temporal variations in shear stress with the extent of oxidative stress, specifically in arterial branching points in comparison with straight regions in the vessels. For this purpose, a micro shear stress sensor has been designed and fabricated with the backside wire binding feature. The sensors were flush mounted in a 3-D scaled up model of carotid arterial bifurcation to measure the spatial variations in shear stress. These measurements were validated by computational fluid dynamics simulations. Arteries with complex geometries develop a low profile and bidirectional type of shear stress, namely oscillatory however unidirectional and high profile of shear stress, namely pulsatile shear stress develops at straight regions of the vessels. We compared the extent of oxidative stress for the endothelial cells which were ...

SUMMARY: Image-based computational fluid dynamics holds a prominent position in the evaluation of intracranial aneurysms, especially as a promising tool to stratify rupture risk. Current computational fluid dynamics findings correlating both high and low wall shear stress with intracranial aneurysm growth and rupture puzzle researchers and clinicians alike. These conflicting findings may stem from inconsistent parameter definitions, small datasets, and intrinsic complexities in intracranial aneurysm growth and rupture. In Part 1 of this 2-part review, we proposed a unifying hypothesis: both high and low wall shear stress drive intracranial aneurysm growth and rupture through mural cell-mediated and inflammatory cell-mediated destructive remodeling pathways, respectively. In the present report, Part 2, we delineate different wall shear stress parameter definitions and survey recent computational fluid dynamics studies, in light of this mechanistic heterogeneity. In the future, we expect that ...

The moisture absorption behavior of flax fiber-reinforced epoxy composites is deliberated to be a serious issue. This property restricts their usage as outdoor engineering structures. Therefore, this study provides an investigation of moisture in flax fibers on the performance of the flax/epoxy composite materials based on their shear responses. The ±45° aligned flax fibers exposed to different relative humidities (RH) and the vacuum infusion process was used to manufacture the composite specimens. The optimum shear strength (40.25 ± 0.75 MPa) was found for the composites manufactured with 35% RH-conditioned flax fibers, but the shear modulus was reduced consistently with increasing RH values. Although shear strength was increased because of fiber swelling with increased moisture absorption rate until 35% RH environments with good microstructures, nonetheless, strength and modulus both started to decrease after this range. A very poor microstructure has been affirmed by the SEM images of the ...

The use of bender element to measure shear wave velocity is popular due to its simplicity. However, there are still some uncertainties in the interpretation of the bender element test. In this paper, the use of bender elements in the determination of shear wave velocities of dry, unsaturated, and saturated soil specimens is examined with respect to the characteristics of the bender elements, waveform, magnitude, and frequency of the applied voltage to the transmitter bender element and method of travel time determination. The interpretation of the bender element test can be improved if two performance criteria are adopted: (1) a signal-to-noise ratio of at least 4 dB for the receiver signal, and (2) a wave path length to wavelength ratio of at least 3.33. Procedures to estimate the strain level associated with the shear wave velocity measurement using bender element are also described. ...

Title:Flow Shear Induced Changes in Membrane Fluidity: Dependence on Cell- Substrate Adhesion Strength. VOLUME: 9 ISSUE: 1. Author(s): Tamal Das, Tapas K. Maiti and Suman Chakraborty. Affiliation:Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.. Keywords:Cell adhesion, Fluidization, Fluorescence recovery after photobleaching, Lipid raft, Membrane fluidity, Traction force microscopy. Abstract:Besides the internal genetic content and the chemical exchanges with external tissue environment, the physical interactions of cancer cells with its microenvironment also provide the guidelines for successful oncogenesis. During its metastatic journey from primary tumor to distant locations of body, a cancer cell is exposed to stresses of diverse origin and kind, of which fluid shear stresses of interstitial and haematogenic nature have been least studied in relation to their impact in cancer progression. Here, we have designed a biomicrofluidic system ...

0049]FIGS. 3 and 4 show a first prototype of the corrugated board shear stiffness test apparatus or tester. The tester includes a generally upright frame supported on a base 1, with a first clamp 2 fixed at an upper end of the frame at 4 and a second clamp 3 which is free to rotate at a second end of the base 5. There is a small roller bearing 9 underneath the inertial plate that acts as a point for the mechanical oscillation initiator to contact to start the pendulum rotating. The first and second clamps are axially aligned. An inertial plate 7 is attached to the second clamp. An optical electronic pickup 8 such as a Schmidt trigger optical through scan is also carried by the frame and a narrow finger is fixed to the inertial mass to detect when the torsion pendulum passes through the zero angle region. Alternatively, an optical or electrical device may be fitted to obtain full data on the angular position of the inertial plate ...

0015] The low shear insert layer between any two layers of foam can be any material which has a lower internal coefficient of friction than foam. This is also referred to herein as low shear and low shear resistance. Shear force as defined and used herein is an amount of force applied parallel to opposing planar surface of a layer of material of a mattress, such as a topper layer, sufficient to displace one surface of the layer or portion thereof relative to the other surface. Shear resistance as used herein refers to the tendency of a material layer of a mattress topper to resist lateral displacement of one or both major planar sides of the layer. Where the shear force of one of the layers of the mattress top of the present disclosure, such as a fiber layer, is less than the shear force of another layer of the mattress topper such as a foam layer, or less than the shear force between contacting layers of the mattress topper, it is referred to herein as low shear or reduced shear or ...

versus shear stress τ over individual 30-min intervals at the three field sites.. fig. S3. Typical 30-min vertical profile of saltation flux.. fig. S4. Thirty-minute values of saltation layer height zq versus shear velocity u* at the three field sites.. fig. S5. Thirty-minute values of saltation mass flux Q versus wind shear stress τ at the three field sites.. fig. S6. SD of saltation flux values within individual stress bins i, SDQi, versus bin-averaged saltation fluxes, Qi.. data file S1. Excel spreadsheet (.xlsx) containing unbinned 30-min values for shear velocity u*, shear stress τ, wind direction θ, stability parameter z/L, saltation layer height zq, total saltation flux Q, saltation detection frequency fQ, and associated uncertainties for all of these values (except θ, z/L, and fQ) for each field site.. data file S2. Excel spreadsheet (.xlsx) containing binned 30-min values for shear velocity u*, shear stress τ, excess shear stress τex, saltation layer height zq, total saltation ...

PURPOSE: To investigate the effects of 1-year water storage and surface treatments on shear bond strength (SBS) of two composite cements bonded to resin matrix CAD-CAM ceramics (RMCs) and on the mechanical properties of RMCs. MATERIALS AND METHODS: Three types of RMCs were tested: 1. polymer-infiltrated hybrid ceramic (PIHC, Enamic, VITA Zahnfabrik); 2. resin nanoceramic (RNC, Lava Ultimate, 3M Oral Care); and 3. flexible hybrid ceramic (FHC, Cerasmart, GC). One indirect laboratory composite (ILC, Epricord, Kuraray Noritake) was used as control. For each material, 60 plates (14 x 7 x 1 mm) were prepared for the SBS test and submitted to three different surface treatments: following manufacturers instructions, non-thermal atmospheric plasma application (30 s), and plasma + bonding agent. Two composite cements were tested: RelyX Ultimate (3M Oral Care) and Panavia V5 (Kurarary Noritake). Two resin cylinders (1.5 mm diameter x 1.5 mm height) were bonded to each plate (n = 10), with one tested ...

Journal of Nanomaterials is a peer-reviewed, Open Access journal that aims to bring science and applications together on nanoscale and nanostructured materials with emphasis on synthesis, processing, characterization, and applications of materials containing true nanosize dimensions or nanostructures that enable novel/enhanced properties or functions. It is directed at both academic researchers and practicing engineers. Journal of Nanomaterials will highlight the continued growth and new challenges in nanomaterials science, engineering, and nanotechnology, both for application development and for basic research. All papers should emphasize original results relating to experimental, theoretical, computational, and/or applications of nanomaterials ranging from hard (inorganic) materials, through soft (polymeric and biological) materials, to hybrid materials or nanocomposites.

A046 Z-99 Resistivity Imaging for Mapping of Quick Clays for Landslide Risk Assessment Introduction 1 T. DAHLIN 1 V. LEROUX 1 R. LARSSON 2 and K. RANKKA 2 1 Engineering Geology Lund University Box 118 S-221 00 Lund Sweden Quick clay in Sweden is defined as clay with a sensitivity of 50 or more and fully remoulded shear strength of less than 0.4 kPa (Karlsson and Hansbo 1989). The sensitivity is the relation between the undisturbed and the fully remoulded undrained shear strength. The only reliable method for the detection of quick clay used so far in Sweden has been

PAMAM can be used as modified additives for urea-formaldehyde resin adhesive, due to its special structure, a large number of end groups, as well as the nature of the end groups can greatly improve its urea-formaldehyde resin adhesive agent properties. PAMAM-NH2,-OH,-NH3Cl can well improve the performance of urea-formaldehyde adhesive, in particular the quaternary amine-modified PAMAM has more superior performance, compared with conventional curing agent of ammonium chloride, its shear strength increased by 64%.(1) PAMAM contains a large number of surface groups, easily array in the gas-liquid interface, urea-formaldehyde resin surface tension can be reduced , contact angle decreased, increasing the wettability of the wood material surface to provide adhesion.(2) PAMAM contains a large number of active groups to improve reactivity of the system. And form a chemical bridge between the adhesive and the base material to improve adhesion.(3) reducing the viscosity of the system to make it more ...

Tilles AW, Eckstein EC. The near-wall excess of platelet-sized particles in blood flow: its dependence on hematocrit and wall shear rate. Microvasc Res. 1987 Mar; 33(2):211-23 ...

Coronary artery stenosis is commonly treated by stent placement via percutaneous intervention, at times requiring multiple stents that may overlap. Stent overlap is associated with increased risk of adverse clinical outcome. While changes in local blood flow are suspected to play a role therein, hemodynamics in arteries with overlapping stents remain poorly understood. In this study we analyzed six cases of partially overlapping stents, placed ex vivo in porcine left coronary arteries and compared them to five cases with two non-overlapping stents. The stented vessel geometries were obtained by micro-computed tomography of corrosion casts. Flow and shear stress distribution were calculated using computational fluid dynamics. We observed a significant increase in the relative area exposed to low wall shear stress ( ...

TY - JOUR. T1 - Shear stress activation of SREBP1 in endothelial cells is mediated by integrins. AU - Liu, Yi. AU - Chen, Benjamin P C. AU - Lu, Min. AU - Zhu, Yi. AU - Stemerman, Michael B.. AU - Chien, Shu. AU - Shyy, John Y J. PY - 2002/1/29. Y1 - 2002/1/29. N2 - We investigated the effect of shear stress on the sterol regulatory element-binding protein 1 (SREBP1) in vascular endothelial cells (ECs) and the mechanotransduction mechanism involved. Application of a shear stress (12 dyn/cm2) caused the proteolytic cleavage of SREBP1 and the ensuing translocation of its transcription factor domain into the nucleus. As a result, shear stress increased the mRNAs encoding the low density lipoprotein receptor (LDLR), as well as the binding of 125I-LDL. Using a step flow channel, we showed that SREBP1 activation in ECs under laminar flow is transient, but disturbed flow causes sustained activation. In studying the shear stress-elicited molecular signaling that activates SREBP1, we found that blocking ...

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We have shown that inhibition of NO production by l-arginine analogues significantly attenuated the development of PSD. To the best of our knowledge, this is the first report of pharmacological antagonism of PSD. Furthermore, the enhanced vascular reactivity of vessel rings to acetylcholine in the poststenotic region is consistent with an important role for endothelium-produced NO as a mediator of PSD. In the present study, large-scale turbulence throughout the flow field is not expected, because the upstream, time-averaged Reynolds numbers were ,100, based on the mean velocity. Turbulence would be expected to occur in this geometry at a Reynolds number of 300 to 400.42 In light of several reports12 13 14 16 17 of steady unidirectional laminar shear stress inducing NO production and elevating eNOS gene expression levels in cultured endothelial cells, elevated wall shear stress or rapid changes in direction and magnitude of wall shear stress are the likely initiators of PSD. This linkage was ...

OBJECTIVE: To apply a new non-invasive method for quantification of in vivo wall shear stress (WSS) by magnetic resonance (MR) FAcE velocity mapping and measure WSS in the human abdominal aorta. DESIGN: Prospective, open study. MATERIAL: Six voluntee

Shear wave velocity measurements.A Siemens ACUSON S2000 US system (Siemens, Germany) equipped with a 3.5-5.5 MHz linear array transducer (4C1) was used for th

Journal of Clinical and Diagnostic Research aims to publish findings of doctors at grass root level and post graduate students, so that all unique medical experiences are recorded in literature.

To determine whether the increased sLex and E-selectin-Ig reactivity corresponds to functional E-selectin binding activity, we tested the ability of FUT6 modified mRNA-transfected hiPS-HSPCs to tether and roll under fluid shear conditions on TNF-α-activated HUVEC monolayers using a parallel plate flow chamber. FUT6 modified mRNA-transfected hiPS-HSPCs showed increasingly higher numbers of rolling cells with increasing shear stress, in contrast to control cells, which maintained uniformly low levels of rolling cells (Figure 2D and Supplemental Video 1). Furthermore, rolling velocities were significantly lower in FUT6 modified mRNA-transfected hiPS-HSPCs, indicative of increased E-selectin ligand binding (Figure 2E). Blocking E-selectin or withholding TNF-α activation decreased the numbers of rolling FUT6 modified mRNA-transfected cells, confirming that their altered rolling properties are mediated exclusively by increased E-selectin ligand activity (Figure 2D and Supplemental Video 2). These ...

To determine whether the increased sLex and E-selectin-Ig reactivity corresponds to functional E-selectin binding activity, we tested the ability of FUT6 modified mRNA-transfected hiPS-HSPCs to tether and roll under fluid shear conditions on TNF-α-activated HUVEC monolayers using a parallel plate flow chamber. FUT6 modified mRNA-transfected hiPS-HSPCs showed increasingly higher numbers of rolling cells with increasing shear stress, in contrast to control cells, which maintained uniformly low levels of rolling cells (Figure 2D and Supplemental Video 1). Furthermore, rolling velocities were significantly lower in FUT6 modified mRNA-transfected hiPS-HSPCs, indicative of increased E-selectin ligand binding (Figure 2E). Blocking E-selectin or withholding TNF-α activation decreased the numbers of rolling FUT6 modified mRNA-transfected cells, confirming that their altered rolling properties are mediated exclusively by increased E-selectin ligand activity (Figure 2D and Supplemental Video 2). These ...

To determine whether the increased sLex and E-selectin-Ig reactivity corresponds to functional E-selectin binding activity, we tested the ability of FUT6 modified mRNA-transfected hiPS-HSPCs to tether and roll under fluid shear conditions on TNF-α-activated HUVEC monolayers using a parallel plate flow chamber. FUT6 modified mRNA-transfected hiPS-HSPCs showed increasingly higher numbers of rolling cells with increasing shear stress, in contrast to control cells, which maintained uniformly low levels of rolling cells (Figure 2D and Supplemental Video 1). Furthermore, rolling velocities were significantly lower in FUT6 modified mRNA-transfected hiPS-HSPCs, indicative of increased E-selectin ligand binding (Figure 2E). Blocking E-selectin or withholding TNF-α activation decreased the numbers of rolling FUT6 modified mRNA-transfected cells, confirming that their altered rolling properties are mediated exclusively by increased E-selectin ligand activity (Figure 2D and Supplemental Video 2). These ...

To determine whether the increased sLex and E-selectin-Ig reactivity corresponds to functional E-selectin binding activity, we tested the ability of FUT6 modified mRNA-transfected hiPS-HSPCs to tether and roll under fluid shear conditions on TNF-α-activated HUVEC monolayers using a parallel plate flow chamber. FUT6 modified mRNA-transfected hiPS-HSPCs showed increasingly higher numbers of rolling cells with increasing shear stress, in contrast to control cells, which maintained uniformly low levels of rolling cells (Figure 2D and Supplemental Video 1). Furthermore, rolling velocities were significantly lower in FUT6 modified mRNA-transfected hiPS-HSPCs, indicative of increased E-selectin ligand binding (Figure 2E). Blocking E-selectin or withholding TNF-α activation decreased the numbers of rolling FUT6 modified mRNA-transfected cells, confirming that their altered rolling properties are mediated exclusively by increased E-selectin ligand activity (Figure 2D and Supplemental Video 2). These ...

Modified urinary fluid shear stress (FSS) induced by variations of urinary fluid flow and composition is observed in early phases of most kidney diseases. Recently, we reported that renal tubular FSS promotes endothelial cell activation and subsequent adhesion of human monocytes, thereby suggesting that changes in urinary FSS can induce the development of inflammation (Miravète M, Klein J, Besse-Patin A, Gonzalez J, Pecher C, Bascands JL, Mercier-Bonin M, Schanstra JP, Buffin-Meyer B, BBRC 407: 813-817, 2011). Here, we evaluated the influence of tubular FSS on monocytes as they play an important role in the progression of inflammation in nephropathies. Human renal tubular cells (HK-2) were exposed to FSS 0.01 Pa for 30 min or 5 h. Treatment of human THP-1 monocytes with the resulting conditioned medium (FSS-CM) modified the expression of macrophage differentiation markers, suggesting differentiation toward the inflammatory M1-type macrophage. The effect was confirmed in freshly isolated human monocytes

An important implication of our findings is that the minimum angle for avalanche release does not depend on shear strength, as is often thought, but results from crackface friction which comes into play only as the fracture through the weak layer is already propagating ...

Most concrete used for construction is a combination of concrete and reinforcement that is called reinforced concrete. Reinforcement for concrete is provided by embedding deformed steel bars or welded wire fabric within freshly made concrete at the time of casting. The purpose of reinforcement is to provide additional strength for concrete where it is needed. The steel provides all the tensile strength where concrete is in tension, as in beams and slabs; it supplements the compressive strength of concrete in columns and walls; and it provides extra shear strength over and above that of concrete in beams.

At some point in lifestyle, you have to have wanted to obtain a garden with your desire residence. Maybe more often than not, individuals have a fantasy of developing bonsai or plants. No matter what is your purpose to possess your backyard at home, you will require certain tools or products including well-defined scissors, garden shears, secateurs, and many more to assist you maintain your backyard garden. This gear can help you in getting your task pruning shears done right more regularly.. Exactly what is the utilization of garden shears?. Horticulture shears are the devices applied to reduce the undesirable or dry divisions and stems, dark brown leaves, or flowers up to about some according to the necessity of your home vegetation. Although you must not take advantage of the exact same horticulture shears with all the very department as every branchs dimensions differs from grow to herb therefore, you need to acquire various sizes of garden shears in order to avoid the risk of destroying ...

Homologous temperature expresses the temperature of a material as a fraction of its melting point temperature using the Kelvin scale: T H = T ( K ) T m p ( K ) {\displaystyle T_{H}={\frac {T({\text{K}})}{T_{mp}({\text{K}})}}} For example, the homologous temperature of lead at room temperature (25 °C) is approximately 0.50 (TH = T/Tmp = 298 K/601 K = 0.50). Solder (Tmp: 183 °C = 456 K) at 0.85Tmp or 115 °C (= 388 K), would thus be expected to have comparable properties to copper (Tmp: 1085 °C = 1358 K) at 0.85Tmp or 881 °C (= 1154 K). In electronics applications, where circuits typically operate over a −55 °C to +125 °C range, eutectic tin-lead (Sn63) solder is working at 0.48Tmp to 0.87Tmp. The upper temperature is high relative to the melting point; from this we can deduce that solder will have limited mechanical strength (as a bulk material) and significant creep under stress. This is borne out by its comparatively low values for tensile strength, shear strength and modulus of ...

Abstract: In a natural clay, the occurrence of a high sensitivity, i.e. a high quotient between the shear strength of the undisturbed and remolded softs respectively, under undrained conditions, is connected to thixotropic effects and to quickness.. The general composition of the soils in which quick clay occurs is described, and mention is made of the occurrence of non-argillaceous rock fragments in a matrix of clay particles. Illite is the main clay mineral. Quickness occurs both in salt-leached, marine deposited clays and in clays deposited in fresh water. The pore water of these clays is low in electrolytes and undecomposed organic material. It is found that quick clays often occur near peat and similar humic deposits. Also briefly discussed is the internal stress distribution in natural clays under various consolidation conditions, the structure of quick clays and their conditions of formation. The consistency of clays is considered, as is the stability and coagulation conditions of ...

Preface xv. 1. Failure Analysis 1. I. Introduction 1. II. Examples of Case Studies Involving Structural Failures 6. III. Summary 25. References 25. Problems 26. 2. Elements of Elastic Deformation 27. I. Introduction 27. II. Stress 27. III. Strain 32. IV. Elastic Constitutive Relationships 35. V. State of Stress Ahead of a Notch 44. VI. Summary 46. References 46. Appendix 2-1: Mohr Circle Equations for a Plane Problem 46. Appendix 2-2: Three-Dimensional Stress Analysis 49. Appendix 2-3: Stress Formulas Under Simple Loading Conditions 54. Problems 57. 3. Elements of Plastic Deformation 59. I. Introduction 59. II. Theoretical Shear Strength 59. III. Dislocations 61. IV. Yield Criteria for Multiaxial Stress 68. V. State of Stress in the Plastic Zone Ahead of a Notch in Plane-Strain Deformation 70. VI. Summary 74. For Further Reading 75. Appendix 3-1: The von Mises Yield Criterion 75. Problems 76. 4. Elements of Fracture Mechanics 80. I. Introduction 80. II. Griffiths Analysis of the Critical Stress ...

Vascular development and homeostasis are underpinned by two fundamental features: the generation of new vessels to meet the metabolic demands of under-perfused regions and the elimination of vessels that do not sustain flow. In this paper we develop the first multiscale model of vascular tissue growth that combines blood flow, angiogenesis, vascular remodelling and the subcellular and tissue scale dynamics of multiple cell populations. Simulations show that vessel pruning, due to low wall shear stress, is highly sensitive to the pressure drop across a vascular network, the degree of pruning increasing as the pressure drop increases. In the model, low tissue oxygen levels alter the internal dynamics of normal cells, causing them to release vascular endothelial growth factor (VEGF), which stimulates angiogenic sprouting. Consequently, the level of blood oxygenation regulates the extent of angiogenesis, with higher oxygenation leading to fewer vessels. Simulations show that network remodelling (and de novo

This module concerns itself with the physical properties of soils and sediments; in particular within the context of shallow engineering and environmental applications. The module will start with the basic physical (or index) properties of a soil and explain how soils may be classified. This is followed by an explanation of effective stress, a key concept in soil mechanics. It will be apparent then, how important water is in determining soil behaviour and for that reason, ideas relating to permeability, hydraulic gradients, potential and flow nets will be presented. The flow of water within soils also plays a key role in controlling soil settlement or consolidation, and so this topic is also a part of the syllabus. Finally, concepts relating to shear strength are introduced.. Because measured soil parameters are often highly influenced by the test protocol and procedure, it is very important that an appreciation of test methods is gained. Therefore, a key element in this module is the laboratory ...

Fits Hitachi, Senco, Pam and Milwaukee.. No. 10 gauge, coarse thread screw used for fastening one layer of drywall to another. . .and a whole lot more. Also used for interior wood projects where shear strength is important. ...

Ukropec, Jon A., Fluid shear stress-induced reorganization of adherens junctions in human endothelial cells (1999). Theses. 24 ...

Many anisotropic phenomenological yield functions have been proposed in the literature in which their predictive capabilities strongly depend on the experimental calibration data as well as the calibration procedure to identify the anisotropy parameters. In this paper, emphasis is placed upon the experimental and numerical calibration procedure of anisotropic yield functions in the region of shear loading (zero hydrostatic stress with equal and opposite in-plane principal strains and stresses). Conventional anisotropic calibration procedures are shown to introduce non-physical artefacts into constitutive models which manifest as a non-zero hydrostatic stress or through-thickness strains generated under in-plane shear stress that violate the definition of the shear loading condition. To overcome this issue, a new physically necessary constraint is applied on the plastic potential to enforce equal and opposite principal strains in the shear state and correct the shear region of anisotropic yield ...

Synonyms for elasticity of shear in Free Thesaurus. Antonyms for elasticity of shear. 2 words related to elasticity of shear: elasticity, snap. What are synonyms for elasticity of shear?

method are considered to study the dynamics and deformation of microscopic deformable cells with elastic and viscoelastic membranes suspended in linear shear flow. The objective in this thesis is to understand the complex fluid/structure interaction problem for membrane-bound soft matter in dilute suspensions. The numerical model includes all essential properties of the cell membrane, namely, the resistance against shear deformation, area dilatation, and bending, as well as the viscosity difference between the cell interior and suspending fluids. In addition, the Kelvin-Voigt viscoelastic model is incorporated to account for the effect of membrane viscosity. Our numerical technique is able to simulate complex dynamics of vesicles, capsules, and red blood cells in the tank-treading, breathing, trembling, and tumbling modes. A detailed comparison of the numerical results for vesicles is made with various theoretical models and experiments. It is found that the applicability of the theoretical ...

This paper presents a study of employing tool rotation-induced vibrations in incremental sheet forming (V-ISF) to produce sheet metal parts with laminated ultrafine-grained structures. Non-axisymmetric tools were developed to generate tool vibration and surface shear deformation of sheet material during forming. Using the V-ISF process, magnesium sheets of AZ31 were formed to the hyperbolic cones and laminated ultrafine grains with higher micro hardness were obtained by tool generated low frequency vibrations with large amplitudes. To further investigate surface shear deformation induced during processing, the hole-deformation analysis of samples cut from the formed hyperbolic cones was performed. This study found that large surface shear deformation of the sheet and the tool vibration during incremental forming are the two key factors for the formation of laminated ultrafine grains. The developed V-ISF process has a great potential to produce sheet metal parts with refined grains and greater ...

Fluid-Structure Interactions in Low-Reynolds-Number Flows (RSC Soft Matter Series, Book 4) by Camille Duprat and Howard A Stone English | 2015 | ISBN: 1849738130 | 483 pages | PDF | 160 MB

Atherosclerosis is initiated by endothelial injury that is related to abnormal values of hemodynamic parameters such as wall shear stress (WSS), oscillator

Bacterial biofilms, while made up of microbial-scale objects, also function as meso- and macroscale materials. In particular, macro-scale material properties determine how biofilms respond to large-scale mechanical stresses, e.g. fluid shear. Viscoelastic and other constitutive properties influence biomass structure (through growth and fluid shear stresses) by erosion and sloughing detachment. In this paper, using the immersed boundary method, biofilm is modelled by a system of viscoelastic, breakable springs embedded in a fluid flow, evolving according to the basic physical laws of conservation of mass and momentum. We demonstrate in the context of computer simulation biofilm deformation and detachment under fluid shear stress ...

This study aims to improve our understanding of strain localization in sands from the meso-scale perspective. First, this research contributes to characterizing and quantifying experimentally the micro- and meso-scale kinematic mechanisms associated with force chains and vortex structures in shear bands in real granular materials. The knowledge gained from this research is relevant for other dense granular flow problems (e.g. silo flow), where force chains control the transition from jammed to flowing states. Also, the results serve to reveal microstructural explanations for different global material responses between softening and critical state. ❧ The Digital Image Correlation (DIC) technique is used to obtain the two-dimensional, incremental surface displacements from digital images of deforming plane strain sand specimens. The aim herein is to use DIC results as a means to 1) evaluate meso-scale kinematic behavior inside shear bands through the course of large deformation, 2) infer the ...