scholarly journals CEMENT LAYER THICKNESS AND SHEAR STRESS RESISTANCE IN CYLINDRICAL DOWEL SPACES: PULL-OUT TEST

2017 ◽  
Vol 10 (4) ◽  
pp. 439
Author(s):  
M Andreasi Bassi
Keyword(s):  
Shear Stress ◽  
Layer Thickness ◽  
Stress Resistance ◽  
Cement Layer ◽  
Pull Out

scholarly journals The Influence of Cement Layer Thickness on the Stress State of Metal Inlay Restorations—Photoelastic Analysis

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 599
Author(s):  
Grzegorz Sokolowski ◽  
Michal Krasowski ◽  
Agata Szczesio-Wlodarczyk ◽  
Bartlomiej Konieczny ◽  
Jerzy Sokolowski ◽  
...  
Keyword(s):  
Stress State ◽  
Layer Thickness ◽  
Resin Composite ◽  
Water Immersion ◽  
Cylindrical Sample ◽  
Resin Cement ◽  
Adhesive Resin ◽  
Cement Layer ◽  
Contraction Stress ◽  
Photoelastic Analysis

The successful restoration of teeth requires a good connection between the inlay and natural tissue. A strong bond may improve retention and reinforce tooth structure. The purpose of this study was to evaluate the influence of cement layer thickness on contraction stress generated during photopolymerization, and to determine the changes in stress state of the cement occurring during aging in water (over 84 days). Two cements were used: resin composite cement (NX3) and self-adhesive resin cement (Maxcem Elite Chroma). A cylindrical sample made of CuZn alloy was used to imitate the inlay. The stress state was measured by photoelastic analysis. The contraction stress of the inlay restoration was calculated for cement layer thicknesses of 25 µm, 100 µm, 200 µm, and 400 µm. For both tested materials, the lowest contraction stress was observed for the thinnest layer (25 µm), and this increased with thickness. Following water immersion, a significant reduction in contraction stress was observed due to hygroscopic expansion. Applying a thin layer (approximately 25 µm) of composite and self-adhesive resin cements resulted in high levels of expansion stresses (over −6 MPa) after water aging.

Surface coating ? No improvement of shear stress resistance of anchorage dependent mammalian cells

1993 ◽  
Vol 7 (7) ◽  
pp. 411-416 ◽  
Author(s):  
Andreas Ludwig ◽  
Ralf Weidemann ◽  
J�rg Tomeczkowski ◽  
Gerlinde Kretzmer
Keyword(s):  
Shear Stress ◽  
Stress Resistance ◽  
Surface Coating ◽  
Mammalian Cells

scholarly journals The ulcerative colitis associated gene FUT8 regulates the quantity and quality of secreted mucins

2021 ◽  
Author(s):  
Gerard Cantero ◽  
Carla Burballa ◽  
Yuki Ohkawa ◽  
Tomohiko Fukuda ◽  
Yoichiro Harada ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Shear Stress ◽  
Stress Resistance ◽  
Viscoelastic Properties ◽  
Distal Part ◽  
Proximal Colon ◽  
Mucus Layer ◽  
Intracellular Accumulation ◽  
Normal Individuals

Fucosylation of mucins, the main macrocomponents of the mucus layer that protects the digestive tract from pathogens, increases their viscoelasticity and shear stress resistance. These properties are altered in patients with ulcerative colitis (UC), which is marked by a chronic inflammation of the distal part of the colon. Here we show that the levels of Fucosyltransferase 8 (FUT8) and specific mucins are increased in the distal inflamed colon of UC patients compared to normal individuals. Overexpressing FUT8, as observed in UC, in mucin-producing HT29-18N2 colonic cell line increases trafficking of MUC1 to plasma membrane and secretion of MUC2/MUC5AC. FUT8 depletion (FUT8 KD), instead, causes intracellular accumulation of MUC1 and alters the ratio of secreted MUC2 to MUC5AC. Mucins secreted by FUT8 overexpressing cells are more resistant to shear stress compared to mucins secreted by FUT8 KD cells. These data fit well with the Fut8-/- mice phenotype, which are protected against UC. Fut8-/- mice exhibit a thinner proximal colon mucus layer with an altered ratio of neutral to acidic mucins compared to Fut8+/+ mice. Together, these data reveal that FUT8 optimizes the viscoelastic properties of the extracellular mucous by controlling the quantities of mucins secreted.

The Effect of PMMA Thickness on Thermal Bone Necrosis around Acetabular Sockets

1994 ◽  
Vol 208 (1) ◽  
pp. 45-51 ◽  
Author(s):  
I C Revie ◽  
M E Wallace ◽  
J F Orr
Keyword(s):  
Layer Thickness ◽  
Hip Replacement ◽  
Curing Temperature ◽  
In Vitro Experiments ◽  
Bone Necrosis ◽  
Maximum Thickness ◽  
Cement Layer ◽  
Temperature Time

One aim of custom acetabular hip replacement sockets is to achieve fixation through a uniform cement layer of selected thickness. In vitro experiments demonstrate that curing temperatures are determined by cement thickness and position relative to the socket rim. A maximum thickness of 7 mm is indicated by interpretation of curing temperature-time relationships in terms of predicted bone necrosis. It is concluded that the results contribute to the establishment of an optimum cement layer thickness, but other factors require investigation to complement this work to gain further understanding of the problem.

scholarly journals Melting Behavior of Heterogeneous Polymer Bulk Solids Related to Flood Fed Single Screw Extruders

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2893
Author(s):  
Christian Kneidinger ◽  
Erik Schroecker ◽  
Gernot Zitzenbacher ◽  
Jürgen Miethlinger
Keyword(s):  
Shear Stress ◽  
Polyamide 6 ◽  
Melting Behavior ◽  
Melting Rate ◽  
Polymer Mixtures ◽  
Mixing Ratios ◽  
Single Screw ◽  
Pull Out ◽  
Single Screw Extruders ◽  
Screw Extruders

Melting models for flood fed single screw extruders, like the Tadmor model, describe the melting of pure thermoplastic polymers. However, the melting behavior of heterogenous polymer systems is of great interest for recycling issues, for example. In this work, the melting of polymer mixtures and that of pure bulk polymers by the drag induced melt removal principle is examined both theoretically and experimentally. The applied model experiments represent the melting of the solid bed at the barrel in single screw extruders. As polymer pellet mixtures, polypropylene-homopolymer mixed with polypropylene-block-copolymer, high density polyethylene, polyamide 6, and polymethylmethacrylate were studied using different mixing ratios. The melting rate and the shear stress in the melt film were evaluated dependent on the mixing ratio. The results show that when processing unfavorable material combinations, both shear stress and melting rate can be far below that of pure materials, which was also confirmed by screw extrusion and screw pull-out experiments. Furthermore, approaches predicting the achievable melting rate and the achievable shear stress of polymer mixtures based on the corresponding values of the pure materials are presented.

Some further considerations of the theory of fibre debonding and pull-out from an elastic matrix. Part 1: Constant interfacial frictional shear stress

Composites ◽  
1993 ◽  
Vol 24 (1) ◽  
pp. 5-11 ◽  
Author(s):  
S.Y. Fu ◽  
B.L. Zhou ◽  
X. Chen ◽  
C.F. Xu ◽  
G.H. He ◽  
...  
Keyword(s):  
Shear Stress ◽  
Elastic Matrix ◽  
Pull Out ◽  
Frictional Shear Stress

Immediate shear stress resistance of endothelial cell monolayers seeded in vitro on fibrin glue-coated ePTFE prostheses

1993 ◽  
Vol 7 (3) ◽  
pp. 324-328 ◽  
Author(s):  
W. Müller-Glauser ◽  
P. Zilla ◽  
M. Lachat ◽  
B. Bisang ◽  
F. Rieser ◽  
...  
Keyword(s):  
Shear Stress ◽  
Endothelial Cell ◽  
Fibrin Glue ◽  
Stress Resistance ◽  
Cell Monolayers

Influence of Single Layer-Thickness on Residual Thermal Stresses in Sm2Zr2O7/YSZ Thermal Barrier Coatings

2013 ◽  
Vol 537 ◽  
pp. 97-100
Author(s):  
Ren Xi Hu ◽  
Xiao Ge Chen ◽  
Gang Li
Keyword(s):  
Shear Stress ◽  
Residual Stresses ◽  
Layer Thickness ◽  
Radial Stress ◽  
Thermal Stresses ◽  
Axial Stress ◽  
Single Layer ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Barrier Coating

In this paper, influence of single-layer thickness on residual stresses in Sm2Zr2O7/YSZ thermal barrier coating was analyzed by finite element method. Results show that the radial stress remains stable in x range 0-12mm, and it decreases abruptly at edge of the sample. The distribution of axial stress resembles that of radial stress, the shear stress increase abruptly at edge of sample. In three typical residual stresses, radial stress has the highest value, axial stress and shear stress can be ignored. The best thickness combination of Sm2Zr2O7/YSZ TBCs should be 0.1mm-NiCoCrAlY layer, 0.05-0.1mm -TGO, 0.1mm-YSZ and 0.9mm-Sm2Zr2O7

The Influence of Anchor Inclination on Pull-out Resistance of Clays

1973 ◽  
Vol 10 (4) ◽  
pp. 664-669 ◽  
Author(s):  
T. H. Hanna
Keyword(s):  
Shear Stress ◽  
Theoretical Model ◽  
Stress State ◽  
In Situ Stress ◽  
Stiff Clays ◽  
Pile Shaft ◽  
Pull Out

A theoretical model is described that was used to examine the influence of anchor inclination on pull-out capacity. Use was made of previous general findings for pile shaft adhesion prediction in stiff clays. It is shown that the adhesion available at the anchor shaft – clay interface depends on: (1) the in situ stress state in the ground; (2) anchor inclination; and (3) the initial shear stress existing in the ground in the direction of the anchor shaft. The possible importance of the reported trends is considered.

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