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Copyright of Industria Textila is the property of Institutul National de Cercetare-Dezvoltare pentru Textile si Pielarie and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The difficulty in landslide treatment is mainly caused by the swelling-shrinkage characteristics of swelling rock and soil. In the process of landslide, creep deformation and swelling deformation occur simultaneously in swelling rock and soil. In order to explore the mechanism of swelling rock and soil landslide, shear tests considering swelling and creep were conducted in four modes, i.e., quick shear test and long-term shear test with natural water content, quick shear test and long-term shear test after swelling under vertical load. Our testing results show that the transient shear strength and long-term shear strength degrade rapidly when rock swells after absorbing water, characterized by the reduction in cohesion, while the angle of friction is nearly unchanged. Mechanism of swelling rock and soil landslide may be illustrated as follows. Due to the climatic wetting and drying cycles, the rock and soil underlayers of the slope undergo repeated swelling and shrinkage, leading to the gradual development of cracks in the rock and soil, which in turn accelerates the water seepage. The repaid decline in strength when swelling rock and soil absorbs water eventually induces shear failure in the slope, leading to landslide. Based on our testing results and the successful experiences in landslide treatment in Guangxi over the past decade, we proposed a few key technologies for landslide treatment, such as conducting necessary stability analysis under saturated condition, and performing insitu large area shear test. We provided methods for stability analysis and thrust force calculation of landslide (slope) with different sliding surfaces and layers, and proposed improvement measures for prevention such as placing sand, taking into account the weather influenced depth, and casing immediately after hole digging. [ABSTRACT FROM AUTHOR]

Laser scanning is one of the methods that can be used for surface treatments of zirconia. Application of the laser to the surface of zirconia has diverse effects, depending on the type of laser. A carbon dioxide (CO2) laser has high irradiation power and can alter the surface properties. This study investigated the surface coating of zirconia as a core material that subsequently coated with a veneering ceramic (v-c) material. This study compared laser scanning and conventional sintering processes. Various properties including surface topography, interface evaluation, phase transformation, elemental compositions, failure mode patterns, and contact angle were examined through X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses. Results were confirmed that the bond strength between the v-c and the substrate recorded through laser scanning was higher than that determined through conventional sintering. [ABSTRACT FROM AUTHOR]

In this research the effect of bedding layer angle and bedding layer thickness on the shear failure mechanism of concrete has been investigated using PFC3D. For this purpose, firstly calibration of PFC3d was performed using Brazilian tensile strength. Secondly shear test was performed on the bedding layer. Thickness of layers were 5 mm, 10 mm and 20 mm. in each thickness layer, layer angles changes from 0° to 90° with increment of 25°. Totally 15 model were simulated and tested by loading rate of 0.016 mm/s. The results shows that when layer angle is less than 50°, tensile cracks initiates between the layers and propagate till coalesce with model boundary. Its trace is too high. With increasing the layer angle, less layer mobilize in failure process. Also the failure trace is very short. It's to be note that number of cracks decrease with increasing the layer thickness. The minimum shear test strength was occurred when layer angle is more than 50°. The maximum value occurred in 0°. Also, the shear test tensile strength was increased by increasing the layer thickness. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Lignocellulosic biomass contains abundant cellulose, hemicellulose and lignin. Ethanol production, which utilizes cellulosic and hemicellulosic fractions of the lignocellulosic biomass, is obtained from the transformation of fermentable sugar. In this case, other fiber portions of biomass like lignin can be considered as byproducts during the conversion process, and these byproducts generally are used to produce octane booster fuels, bio-based products, and chemical productions. For reduction of soil stabilization costs, utilization of lignin-based BCPs (biofuel co-products) as an alternative to stabilize pavement subgrade soil is an innovative idea, and satisfies the needs of sustainable development of construction. This study aims to investigate the utilization of biofuel co-products (BCPs) containing lignin in pavement geo-materials stabilization. Laboratory tests were conducted to evaluate the effect of BCP addition on shear strength performance for a wide range of soils encountered in Iowa. The unconsolidated undrained direct shear test (DST) was used to evaluate shear performance. The results of this study indicate that Biofuel Co-Products are beneficial in the soil stabilization of low quality materials for road construction use. [ABSTRACT FROM AUTHOR]

For the permanent Uni-wall system method, horizontal shear reinforcements are not placed in the joints between the circular casing pile and special casing pile. The joints of piles consequently have a plain concrete section. This study aims to evaluate the shear performance of the plain concrete cross-section found in the permanent Uni-wall system method. This paper analysed the existing design code for a plain concrete cross-section, examined the shear performance of joints through shear experiments, and then compared the results with those from a structural analysis. From the test results, it was found that the minimum shear strength of all specimens had 2·98 times greater bearing capacity than the nominal shear strength. [ABSTRACT FROM AUTHOR]

Tension and compression tests were conducted on a ceramic-fiber-reinforced Si02 aerogel (CFRSA). The material exhibits different tension and compression modulus, i.e., bi-modulus. The objective of present research is to establish guidelines for preparing shear tests of this CFRSA. Finite-element analysis (FEA) on various losipescu specimens is presented for four bi-modulus materials, including the CFRSA. It is found that the major concerns for specimen design of bi-modulus materials are: the uniformity of shear stress and the longitudinal normal stress concentration at notch tips. These concerns are all dependent on material properties. For material with Et numerically close to Ec, the normal stress concentration near notch tips is of less significance. Flowever, for material with high tension-compression asymmetry, including this CFRSA, the normal stress concentration near notch tips is significant. The round-notch specimen with small normal stress concentration seems to be favorable for these materials. [ABSTRACT FROM AUTHOR]

Copyright of Tecnologia em Metalurgia, Materiais e Mineração is the property of Associacao Brasileira de Metalurgia e Materiais and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Estimation of the shear strength of precast, prestressed concrete hollow-core units in the United States follows the shear provisions of ACI 318-08. These provisions are based on experimental research conducted mainly on members other than hollow-core units. These provisions have been extended to hollow-core units based on a limited number of hollow-core unit shear tests. Recent shear tests performed on thick hollow-core units (depths greater than 12 in. [300 mm]) by several U.S. manufacturers have shown that these units fail in the web-shear tension mode at forces smaller than those predicted by the Building Code Requirements for Structural Concrete (ACI 318-05) and Commentary (ACI 318 R-05). Some fail at shear forces equal to 60% of the ACI 318-05 predicted strength. As a consequence, ACI 318-08 now requires minimum shear reinforcement to be supplied in hollow-core units with depths greater than 12.5 in. (318 mm) if the factored shear force exceeds 50% of the design shear strength of the concrete or the web-shear capacity must be reduced by 50%. A research program was conducted to investigate the prediction of the web-shear capacities of thick hollow-core units and to quantify the reasons why these thicker units are failing at lower shear forces than those predicted using the ACI 318-05 provisions. The reduced shear capacity appears to correlate with increased end slip of the strand and with poorer consolidation of the concrete. [ABSTRACT FROM AUTHOR]

Abstract: Ultraviolet (UV)-photofunctionalization of titanium substantially enhances the strength and quality of osseointegration by promoting osteogenic cellular attachment and proliferation. However, the mechanism underlying the initial interaction between the cells and the surface of the material remains to be elucidated, especially where the influence of surface roughness is excluded as a factor. The effect of UV-photofunctionalization on the adhesive strength and cellular stiffness of a single osteoblast and its association with the extent of cell spread, cytoskeletal development and focal adhesion assembly on a very smooth titanium surface was evaluated. Rat bone marrow-derived osteoblasts were cultured on UV-treated or untreated mirror-polished titanium disks. The mean critical shear force required to initiate detachment of a single osteoblast (n =10) was >2000nN on a UV-treated surface at 3h incubation, which was 17 times greater than that on an untreated surface. The mean total energy required to complete the detachment of osteoblasts (n =10) was consistently >60pJ on a UV-treated titanium surface after 24h culture, which was up to 42 times greater than that on an untreated surface. Cellular shear modulus, which represents cellular stiffness, was consistently greater on a UV-treated surface than on an untreated surface after 24h incubation (n =10). This strengthening of cell adhesion and cellular mechanical properties on UV-treated titanium was accompanied by enhanced cell spread and actin fiber development and increased levels of vinculin expression. These results indicate that UV-photofunctionalization substantially strengthens osteoblast retention on titanium bulk material with no topographical features, and that this is associated with enhancement of intracellular structural development during the cell adhesion process. [ABSTRACT FROM AUTHOR]

This study tested the bond strength of a resin cement to a glass-infiltrated zirconia-alumina ceramic after three conditioning methods and using two test methods (shear-SBS versus microtensile-MTBS). Ceramic blocks for MTBS and ceramic disks for SBS were fabricated. Three surface conditioning (SC) methods were evaluated: (1) 110-μn Al2O3+silanization; (2) Chairside silica coating+silanization; (3) Laboratory silica coating+silanization. Following surface conditioning, the resin cement (Panavia F) was bonded to the conditioned ceramics. Although no statistically significant differences (p=0.1076) were seen between the test methods, results yielded with the different surface conditioning methods showed statistically significant differences (p<0.0001) (SC2=5C3>SC1). As for the interaction between the factors, two-way ANOVA showed that it was not statistically significant (p=0.1443). MTBS test resulted in predominantly mixed failure (85%), but SBS test resulted in exclusively adhesive failure. On the effects of different surface conditioning methods, chairside and laboratory tribochemical silica coating followed by silanization showed higher bond strength results compared to those of aluminum oxide abrasion and silanization, independent of the test method employed. [ABSTRACT FROM AUTHOR]

A numerical study of a modified specimen geometry for the inclined double notch shear (IDNS) test was performed. The test uses the standard double notch compression (DNC) specimen whose geometry was modified by replacing the straight grooves with tilted V notches. Arising stress fields were calculated by use of a BEM scheme. Four different geometry parameters were investigated: relative notch distance, specimen loading, and notch tilt and notch opening angles. Different evaluation criteria to determine optimal specimen and test geometries were studied with respect to effects on stress uniformity and stress concentrations/singularities. No single criterion was found to be obviously superior. Judicious specimen loading enabled cancellation of the significant mode I singularity, whereas a careful specimen design enabled the simultaneous cancellation of both modes I and mode II singularities in most specimens. Singular fields (for mathematically sharp notches) were predominant over distances comparable to the root radii used in practice, and thus not very relevant. Further, the shear stress level arising in the specimen center (and in its major part) was controlled by the specimen inclination, whereas stress concentrations in the notch root vicinity were governed mainly by notch tilt and notch opening angles. Appropriately tilted, but sharper notches seemed to result in the generally most uniform stress fields. For the issues studied, several accurate closed form expressions were presented. [ABSTRACT FROM AUTHOR]