Displaying publications 21 - 40 of 46 in total

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  1. Fulltext Strengthening the Structural Behavior of Web Openings in RC Deep Beam Using CFRP
    Rahim NI, Mohammed BS, Al-Fakih A, Wahab MMA, Liew MS, Anwar A, et al.
    Materials (Basel), 2020 Jun 22;13(12).
    PMID: 32580327 DOI: 10.3390/ma13122804
    Deep beams are more susceptible to shear failure, and therefore reparation is a crucial for structural reinforcements. Shear failure is structural concrete failure in nature. It generally occurs without warning; however, it is acceptable for the beam to fail in bending but not in shear. The experimental study presented the structural behavior of the deep beams of reinforced concrete (RC) that reinforces the web openings with externally connected carbon fiber reinforced polymer (CFRP) composite in the shear zone. The structural behavior includes a failure mode, and cracking pattern, load deflection responses, stress concentration and the reinforcement factor were investigated. A total of nine reinforced concrete deep beams with openings strengthened with CFRP and one control beam without an opening have been cast and tested under static four-point bending load till failure. The experimental results showed that the increase the size of the opening causes an increase in the shear strength reduction by up to 30%. Therefore, the larger the openings, the lower the capability of load carriage, in addition to an increase in the number of CFRP layers that could enhance the load carrying capacity. Consequently, utilization of the CFRP layer wrapping technique strengthened the shear behavior of the reinforced concrete deep beams from about 10% to 40%. It was concluded that the most effective number of CFRP layers for the deep beam with opening sizes of 150 mm and 200 mm were two layers and three layers, respectively.
    Matched MeSH terms: Shear Strength
  2. Fulltext Influence of Secondary Reinforcement on Behaviour of Corbels with Various Types of High-Performance Fiber-Reinforced Cementitious Composites
    Md Zin N, Al-Fakih A, Nikbakht E, Teo W, Anwar Gad M
    Materials (Basel), 2019 Dec 11;12(24).
    PMID: 31835775 DOI: 10.3390/ma12244159
    An experimental study is conducted to determine the influence of secondary reinforcement on the behaviour of corbels fabricated with three different types of high-performance fiber-reinforced cementitious composites, including engineered cementitious concrete (ECC); high-performance steel fiber-reinforced composite (HPSFRC); and hybrid fiber-reinforced composite (HyFRC). Two shear span-to-depth ratios (a/d = 0.75 and 1.0) are explored. The mechanical properties of the composites in terms of tensile, compressive, and flexural strengths are investigated. Next, the structural behaviour of the high-performance cementitious composite corbels in terms of ultimate load capacity, ductility, and failure modes under the three-point bending test are investigated. The secondary reinforcement is proven to significantly affect stiffness and ultimately load capacity of all three high-performance composite corbels with an aspect ratio of 0.75. However, the secondary reinforcement was more impactful for the HPSFRC corbels, with 51% increase of ultimate strength. Moreover, in terms of damage, fewer cracks occurred in ECC corbels. HPSFRC corbels displayed the highest level of ductility and deformation capacity compared to the other specimens. The results were comparatively analyzed against the predicted results using truss and plastic truss models which provided relatively reliable shear strength.
    Matched MeSH terms: Shear Strength
  3. Fulltext Effect of Tilt Angle and Pin Depth on Dissimilar Friction Stir Lap Welded Joints of Aluminum and Steel Alloys
    Chitturi V, Pedapati SR, Awang M
    Materials (Basel), 2019 Nov 26;12(23).
    PMID: 31779107 DOI: 10.3390/ma12233901
    Automobile, aerospace, and shipbuilding industries are looking for lightweight materials for cost effective manufacturing which demands the welding of dissimilar alloy materials. In this study, the effect of tool rotational speed, welding speed, tilt angle, and pin depth on the weld joint were investigated. Aluminum 5052 and 304 stainless-steel alloys were joined by friction stir welding in a lap configuration. The design of the experiments was based on Taguchi's orthogonal array for conducting the experiments with four factors and three levels for each factor. The microstructural analysis showed tunnel defects, micro voids, and cracks which formed with 0° and 1.5° tilt angles. The defects were eliminated when the tilt angle increased to 2.5° and a mixed stir zone was formed with intermetallic compounds. The presence of the intermetallic compounds increased with the increase in tilt angle and pin depth which further resulted in obtaining a defect-free weld. Hooks were formed on either side of the weld zone creating a mechanical link for the joint. A Vickers hardness value of HV 635.46 was achieved in the mixed stir zone with 1000 rpm, 20 mm/min, and 4.2 mm pin depth with a tilt angle of 2.5°, which increased by three times compared to the hardness of SS 304 steel. The maximum shear strength achieved with 800 rpm, 40 mm/min, and a 4.3 mm pin depth with a tilt angle of 2.5° was 3.18 kN.
    Matched MeSH terms: Shear Strength
  4. Effects of naturally-produced lovastatin on carcass characteristics, muscle physico-chemical properties and lipid oxidation and cholesterol content in goats
    Garba S, Sazili AQ, Mahadzir MF, Candyrine SCL, Jahromi MF, Ebrahimi M, et al.
    Meat Sci, 2019 Aug;154:61-68.
    PMID: 31004941 DOI: 10.1016/j.meatsci.2019.04.008
    This study investigated the carcass characteristics, physico-chemical properties, storage stability and cholesterol content of meat from goats fed with different levels of naturally-produced lovastatin used to mitigate enteric methane production. Twenty intact Saanen male goats of 5-6 months old with initial live weight of 25.8 ± 4.0 kg were randomly allotted into four dietary treatments containing 0 (Control), 2 (Low), 4 (Medium) and 6 mg (High) per kg live weight (LW) of naturally-produced lovastatin for 12 consecutive weeks. No differences were found in all the parameters measured except for full LW, hot and cold carcass weight, shear force, color and cholesterol content among the treatment groups. Aging had significant effects on all the parameters measured in this study except a* (redness) of meat. Meat samples in the Medium and High treatments were of higher lightness and yellowness, more tender and lower cholesterol levels. We conclude that, in addition to mitigate enteric methane emissions, dietary supplementation of naturally-produced lovastatin at 4 mg/kg LW could be a feasible feeding strategy to produce tender meat containing lower cholesterol.
    Matched MeSH terms: Shear Strength/drug effects
  5. Interventions of two-stage thermal sous-vide cooking on the toughness of beef semitendinosus
    Ismail I, Hwang YH, Joo ST
    Meat Sci, 2019 Nov;157:107882.
    PMID: 31295690 DOI: 10.1016/j.meatsci.2019.107882
    This paper describes the influence of different factors on toughness of beef semitendinosus (ST) by means of low temperature-long time cooking with single-stage (60 °C, 65 °C, 70 °C, and 75 °C for 6 h and 12 h) and two-stage sous-vide procedure (45 + 60 °C, 45 + 65 °C, 45 + 70 °C, and 45 + 75 °C; 49 + 60 °C, 49 + 65 °C, 49 + 70 °C, and 49 + 75 °C for 3 h at the first temperature, and either 3 or 9 h at the second temperature). Reduced toughness of ST beef steak muscle could be attained in 6 h at 60 °C and 45 + 60 °C were due from the minimum shrinkage of sarcomere as well as lower perimysial thickness, cooking loss, and elastic modulus. Collagen solubility showed a positive correlation to the toughness values. The relationship between proteolytic activity and shear force can be seen after 12 h of cooking duration. For the other quality attributes, two stepped cooking temperature-time combination seems to be more effective in preserving the redness values and water content than a single-stage sous-vide method.
    Matched MeSH terms: Shear Strength*
  6. Design and validation of a bi-axial loading bioreactor for mechanical stimulation of engineered cartilage
    Yusoff N, Abu Osman NA, Pingguan-Murphy B
    Med Eng Phys, 2011 Jul;33(6):782-8.
    PMID: 21356602 DOI: 10.1016/j.medengphy.2011.01.013
    A mechanical-conditioning bioreactor has been developed to provide bi-axial loading to three-dimensional (3D) tissue constructs within a highly controlled environment. The computer-controlled bioreactor is capable of applying axial compressive and shear deformations, individually or simultaneously at various regimes of strain and frequency. The reliability and reproducibility of the system were verified through validation of the spatial and temporal accuracy of platen movement, which was maintained over the operating length of the system. In the presence of actual specimens, the system was verified to be able to deliver precise bi-axial load to the specimens, in which the deformation of every specimen was observed to be relatively homogeneous. The primary use of the bioreactor is in the culture of chondrocytes seeded within an agarose hydrogel while subjected to physiological compressive and shear deformation. The system has been designed specifically to permit the repeatable quantification and characterisation of the biosynthetic activity of cells in response to a wide range of short and long term multi-dimensional loading regimes.
    Matched MeSH terms: Shear Strength
  7. Fulltext Effect of sandblasting, silica coating, and erbium: Yttrium-Aluminum-Garnet laser treatment on the shear bond strength of self-adhesive resin cement to alumina ceramics
    Caglar I, Ates SM, Boztoprak Y, Aslan YU, Duymus ZY
    Niger J Clin Pract, 2018 Aug;21(8):1000-1007.
    PMID: 30074001 DOI: 10.4103/njcp.njcp_300_17
    Objective: The aim of this study was to investigate the different surface treatments on the bond strength of self-adhesive resin cement to high-strength ceramic.

    Materials and Methods: Ninety aluminum oxide ceramic (Turkom-Ceramic Sdn. Bhd., Kuala Lumpur, Malaysia) specimens were produced and divided into nine groups to receive the following surface treatments: control group, no treatment (Group C), sandblasting (Group B), silica coating (Group S), erbium: yttrium-aluminum-garnet (Er:YAG) laser irradiation at 150 mJ 10 Hz (Group L1), Er:YAG laser irradiation at 300 mJ 10 Hz (Group L2), sandblasting + L1 (Group BL1), sandblasting + L2 (Group BL2), silica coating + L1 (Group SL1), and silica coating + L2 (Group SL2). After surface treatments, surface roughness (SR) values were measured and surface topography was evaluated. Resin cement was applied on the specimen surface, and shear bond strength (SBS) tests were performed. Data were statistically analyzed using one-way ANOVA and Tukey's multiple comparisons at a significance level of P < 0.05.

    Results: Group S, SL1, and SL2 showed significantly increased SR values compared to the control group (P < 0.05); therefore, no significant differences were found among the SR values of Groups B, BL1, BL2, L1, and L2 and the control group (P > 0.05). Group S showed the highest SBS values, whereas the control group showed the lowest SBS values.

    Conclusion: Silica coating is the most effective method for resin bonding of high strength ceramic, but Er:YAG laser application decreased the effectiveness.

    Matched MeSH terms: Shear Strength
  8. Relationship between shear strength and soil water characteristic curve of an unsaturated granitic residual soil
    Huat, Bujang B.K, Faisal Ali, Hashim, S.
    Pertanika Journal of Science & Technology, 2007;15(2):113-120.
    MyJurnal
    The three shear strength parameters that are required to define a failure envelope of an unsaturated soil are c' (apparent cohesion),
    Matched MeSH terms: Shear Strength
  9. Fulltext The magnetohydrodynamic stagnation point flow of a nanofluid over a stretching/shrinking sheet with suction
    Mansur S, Ishak A, Pop I
    PLoS One, 2015;10(3):e0117733.
    PMID: 25760733 DOI: 10.1371/journal.pone.0117733
    The magnetohydrodynamic (MHD) stagnation point flow of a nanofluid over a permeable stretching/shrinking sheet is studied. Numerical results are obtained using boundary value problem solver bvp4c in MATLAB for several values of parameters. The numerical results show that dual solutions exist for the shrinking case, while for the stretching case, the solution is unique. A stability analysis is performed to determine the stability of the dual solutions. For the stable solution, the skin friction is higher in the presence of magnetic field and increases when the suction effect is increased. It is also found that increasing the Brownian motion parameter and the thermophoresis parameter reduces the heat transfer rate at the surface.
    Matched MeSH terms: Shear Strength
  10. Fulltext Rheological studies of PMMA-PVC based polymer blend electrolytes with LiTFSI as doping salt
    Liew CW, Durairaj R, Ramesh S
    PLoS One, 2014;9(7):e102815.
    PMID: 25051241 DOI: 10.1371/journal.pone.0102815
    In this research, two systems are studied. In the first system, the ratio of poly (methyl methacrylate) (PMMA) and poly (vinyl chloride) (PVC) is varied, whereas in the second system, the composition of PMMA-PVC polymer blends is varied with dopant salt, lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) with a fixed ratio of 70 wt% of PMMA to 30 wt% of PVC. Oscillation tests such as amplitude sweep and frequency sweep are discussed in order to study the viscoelastic properties of samples. Elastic properties are much higher than viscous properties within the range in the amplitude sweep and oscillatory shear sweep studies. The crossover of G' and G'' is absent. Linear viscoelastic (LVE) range was further determined in order to perform the frequency sweep. However, the absence of viscous behavior in the frequency sweep indicates the solid-like characteristic within the frequency regime. The viscosity of all samples is found to decrease as shear rate increases.
    Matched MeSH terms: Shear Strength
  11. Fulltext Comparative reliability studies and analysis of Au, Pd-coated Cu and Pd-doped Cu wire in microelectronics packaging
    Chong Leong G, Uda H
    PLoS One, 2013;8(11):e78705.
    PMID: 24244344 DOI: 10.1371/journal.pone.0078705
    This paper compares and discusses the wearout reliability and analysis of Gold (Au), Palladium (Pd) coated Cu and Pd-doped Cu wires used in fineline Ball Grid Array (BGA) package. Intermetallic compound (IMC) thickness measurement has been carried out to estimate the coefficient of diffusion (Do) under various aging conditions of different bonding wires. Wire pull and ball bond shear strengths have been analyzed and we found smaller variation in Pd-doped Cu wire compared to Au and Pd-doped Cu wire. Au bonds were identified to have faster IMC formation, compared to slower IMC growth of Cu. The obtained weibull slope, β of three bonding wires are greater than 1.0 and belong to wearout reliability data point. Pd-doped Cu wire exhibits larger time-to-failure and cycles-to-failure in both wearout reliability tests in Highly Accelerated Temperature and Humidity (HAST) and Temperature Cycling (TC) tests. This proves Pd-doped Cu wire has a greater potential and higher reliability margin compared to Au and Pd-coated Cu wires.
    Matched MeSH terms: Shear Strength
  12. Fulltext Refinement of Strut-and-Tie Model for Reinforced Concrete Deep Beams
    Panjehpour M, Chai HK, Voo YL
    PLoS One, 2015;10(6):e0130734.
    PMID: 26110268 DOI: 10.1371/journal.pone.0130734
    Deep beams are commonly used in tall buildings, offshore structures, and foundations. According to many codes and standards, strut-and-tie model (STM) is recommended as a rational approach for deep beam analyses. This research focuses on the STM recommended by ACI 318-11 and AASHTO LRFD and uses experimental results to modify the strut effectiveness factor in STM for reinforced concrete (RC) deep beams. This study aims to refine STM through the strut effectiveness factor and increase result accuracy. Six RC deep beams with different shear span to effective-depth ratios (a/d) of 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00 were experimentally tested under a four-point bending set-up. The ultimate shear strength of deep beams obtained from non-linear finite element modeling and STM recommended by ACI 318-11 as well as AASHTO LRFD (2012) were compared with the experimental results. An empirical equation was proposed to modify the principal tensile strain value in the bottle-shaped strut of deep beams. The equation of the strut effectiveness factor from AASHTTO LRFD was then modified through the aforementioned empirical equation. An investigation on the failure mode and crack propagation in RC deep beams subjected to load was also conducted.
    Matched MeSH terms: Shear Strength*
  13. Fulltext Experimental and numerical evaluations of composite concrete-to-concrete interfacial shear strength under horizontal and normal stresses
    Al-Fasih MY, Mohamad ME, Ibrahim IS, Ahmad Y, Ariffin MAM, Sarbini NN, et al.
    PLoS One, 2021;16(5):e0252050.
    PMID: 34015027 DOI: 10.1371/journal.pone.0252050
    Effects of different surface textures on the interface shear strength, interface slip, and failure modes of the concrete-to-concrete bond are examined through finite element numerical model and experimental methods in the presence of the horizontal load with 'push-off' technique under different normal stresses. Three different surface textures are considered; smooth, indented, and transversely roughened to finish the top surfaces of the concrete bases. In the three-dimensional modeling via the ABAQUS solver, the Cohesive Zone Model (CZM) is used to simulate the interface shear failure. It is observed that the interface shear strength increases with the applied normal stress. The transversely roughened surface achieves the highest interface shear strength compared with those finished with the indented and smooth approaches. The smooth and indented surfaces are controlled by the adhesive failure mode while the transversely roughened surface is dominated by the cohesive failure mode. Also, it is observed that the CZM approach can accurately model the interface shear failure with 3-29% differences between the modeled and the experimental test findings.
    Matched MeSH terms: Shear Strength
  14. Fulltext Forecasting shear stress parameters in rectangular channels using new soft computing methods
    Sheikh Khozani Z, Sheikhi S, Mohtar WHMW, Mosavi A
    PLoS One, 2020;15(4):e0229731.
    PMID: 32271780 DOI: 10.1371/journal.pone.0229731
    Shear stress comprises basic information for predicting the average depth velocity and discharge in channels. With knowledge of the percentage of shear force carried by walls (%SFw) it is possible to more accurately estimate shear stress values. The %SFw, non-dimension wall shear stress ([Formula: see text]) and non-dimension bed shear stress ([Formula: see text]) in smooth rectangular channels were predicted by a three methods, the Bayesian Regularized Neural Network (BRNN), the Radial Basis Function (RBF), and the Modified Structure-Radial Basis Function (MS-RBF). For this aim, eight data series of research experimental results in smooth rectangular channels were used. The results of the new method of MS-RBF were compared with those of a simple RBF and BRNN methods and the best model was selected for modeling each predicted parameters. The MS-RBF model with RMSE of 3.073, 0.0366 and 0.0354 for %SFw, [Formula: see text] and [Formula: see text] respectively, demonstrated better performance than those of the RBF and BRNN models. The results of MS-RBF model were compared with three other proposed equations by researchers for trapezoidal channels and rectangular ducts. The results showed that the MS-RBF model performance in estimating %SFw, [Formula: see text] and [Formula: see text] is superior than those of presented equations by researchers.
    Matched MeSH terms: Shear Strength*
  15. Soil-root shear strength properties of some slope plants
    Normaniza Osman, Mohamad Nordin Abdullah, Faisal Haji Ali
    Sains Malaysiana, 2011;40:1065-1073.
    Rapid development in hilly areas in Malaysia has become a trend that put a stress to the sloping area. It reduces the factor of safety by reducing the resistant force and therefore leads to slope failure. Vegetation plays a big role in reinforcement functions via anchoring the soils and forms a binding network within the soil layer that tied the soil masses together. In this research, three plant species namely Acacia mangium, Dillenia suffruticosa and Leucaena leucocephala were assessed in term of their soil-root shear strength properties. Our results showed that Acacia mangium had the highest shear strength values, 30.4 kPa and 50.2 kPa at loads 13.3 kPa and 24.3 kPa, respectively. Leucaena leucocephala showed the highest in cohesion factor, which was almost double the value in those of Dillenia suffruticosa and Acacia mangium. The root profile analysis indicated Dillenia suffruticosa exhibited the highest values in both root length density and root volume, whilst Leucaena leucocephala had the highest average of root diameter.
    Matched MeSH terms: Shear Strength
  16. New progress in the study of intergranular suction and shear strength of unsaturated soil
    Liansheng Tang, Haitao Sang, Liqun Jiang, Yinlei Sun
    Sains Malaysiana, 2016;45:141-156.
    The suction between soil particles is the basis and core problem in the study of unsaturated soil. However, is the suction between soil particles just the matrix suction (which has been widely used since the discipline of unsaturated soil mechanics was established). In fact, the concept of matrix suction is from soil science and reflects the water-absorbing capacity of the soil. Matrix suction characterizes the interaction between soil particles and pore water rather than the interactions between soil particles, which were not in conformity with the principle of effective stress of soils. The suction of unsaturated soil, in essence, is the intergranular suction composed of absorbed suction and structural suction. In this paper, first, the basic concepts of absorbed suction and structural suction were briefly introduced. Then, with soil mechanics, powder science, crystal chemistry, granular material mechanics and other related disciplines of knowledge for reference, the quantitative calculation formulas were theoretically deduced for the absorbed suction for equal-sized and unequal-sized unsaturated soil particles with arbitrary packing and the variable structural suction for equal-sized unsaturated soil particles with arbitrary packing and unequal-sized unsaturated soil particles with close tetrahedral packing. The factors that influence these equations were discussed. Then, the shear strength theory of unsaturated soil was established based on the theory of intergranular suction through the analysis of the effective stress principle of unsaturated soil. This study demonstrates that the shear strength of unsaturated soil consists of three parts: The effective cohesive force, the additional strength caused by external loads and the strength caused by intergranular suction. The contribution of the three parts to the shear strength of unsaturated soil depends on the following influence factors: Soil type, confining pressure, water content and density. Therefore, these factors must be comprehensively considered when determining the strength of an unsaturated soil.
    Matched MeSH terms: Shear Strength
  17. Engineering geological properties of oil-contaminated granitic and metasedimentary soils
    Zulfahmi Ali Rahman, Umar Hamzah, Noorulakma Ahmad
    Sains Malaysiana, 2011;40.
    Hydrocarbon is a light-non aqueous phase liquid or known as LNAPL. It poses environmental hazard if accidentally spilled out into the soil and water systems as a result of its insoluble nature in water. LNAPL component infiltrates into soil through pore spaces and afloat at the top of groundwater level. Some of this hydrocarbon would trap and clog within the voids, difficult to remove and costly to clean. The occurence of hydrocarbon in the soil definitely degraded the behaviour of soils in terms of engineering properties. This study aimed to investigate the engineering properties of oil-contaminated soil for two different residual soils originally developed from in-situ weathering of granitic and metasedimentary rocks. The physical characterisations of the soil were determined including particle size distribution, specific gravity test and x-ray diffraction (XRD). The engineering parameters for the contaminated and uncontaminated soils were Atterberg limits, compaction and soil shear strength (UU tests). The amounts of hydrocarbon added to soil were varied at 0%, 4%, 8%, 12% and 16% of dried weigth of soil samples. The results from the particle size distribution analysis showed that residual soil from granitic rock comprises of 38% sand, 33% silt and 4% clay while metasedimentary soil consists of 4% sand, 43% silt dan 29% clay. The mean values of specific gravity for the granitic and metasedimentary soils were 2.56 and 2.61, respectively. The types of minerals present in granitic soil sample were quartz, kaolinite and gibbsite while metasedimentary soil consists of quartz and kaolinite. The Atterberg limits value decreased as a result of increasing amount of added hydrocarbon into the soil. A similar behaviouir was observed with the values of maximum dry density and optimum water content with increasing hydrocarbon content. The overall unconsolidated undrained shear strength, Cu showed a decreasing trend with the increase in hydrocarbon content.
    Matched MeSH terms: Shear Strength
  18. Environmental geological features of the red clay surrounding rock deformation under the influence of rock-fracture water
    Jiading Wang, Tianfeng Gu, Jianbin Wang, Yuanjun Xu, Peng Chen, Muhammad Aqeel Ashraf
    Sains Malaysiana, 2017;46:2049-2059.
    The development degree of fissure water in underground rock is a great trouble to the construction of railway tunnel, which will cause a series of environmental geological problems. Take the surrounding rock-section of the typical red clay in Lvliang-Mt. railway tunnel below the underground water level as an example, several aspects about the red clay surrounding rock will be researched, including pore water pressure, volume moisture content, stress of surrounding rock, vault subsidence and horizontal convergence through the field monitoring. Taking into account the importance of railway tunnel engineering, the large shear test of red clay was carried out at the construction site specially and the reliable situ shear strength parameters of surrounding rock will be obtained. These investigations and field tests helped to do a series of work: Three dimensional finite element numerical model of railway tunnel will be established, the deformation law of the red clay surrounding rock will be investigated, respectively, for the water-stress coupling effect and without considering it, the variation of the pore water pressure during excavation, the influence degree about the displacement field and stress field of water-stress coupling on red clay-rock will be discussed and the mechanism of the surrounding rock deformation will be submitted. Finally, the paper puts forward the feasible drainage scheme of the surrounding rock and the tunnel cathode. The geological environment safety of tunnel construction is effectively protected.
    Matched MeSH terms: Shear Strength
  19. Shear strength of cemented sand gravel and rock materials
    Zhongwei Liu, Jinsheng Jia, Wei Feng, Fengling Ma, Cuiying Zheng
    Sains Malaysiana, 2017;46:2101-2108.
    Shear strength is currently a significant parameter in the design of cemented sand gravel and rock (CSGR) dams. Shear strength tests were carried out to compare material without layers noumenon and layer condition. The experimental results showed good linearity in the curves of shear strength and pure grinding tests with correlation coefficients of nearly 97%. The friction coefficient was similar to that of C10 roller-compacted concrete (RCC), but the cohesion value was weaker than that of RCC. The shear strength of the CSGR layers decreased by 40% when retarding mixtures were not added and the layer was paved immediately after 4 h of waiting interval.
    Matched MeSH terms: Shear Strength
  20. Fulltext Cigarette smoke extract profoundly suppresses TNFα-mediated proinflammatory gene expression through upregulation of ATF3 in human coronary artery endothelial cells
    Teasdale JE, Hazell GG, Peachey AM, Sala-Newby GB, Hindmarch CC, McKay TR, et al.
    Sci Rep, 2017 Jan 06;7:39945.
    PMID: 28059114 DOI: 10.1038/srep39945
    Endothelial dysfunction caused by the combined action of disturbed flow, inflammatory mediators and oxidants derived from cigarette smoke is known to promote coronary atherosclerosis and increase the likelihood of myocardial infarctions and strokes. Conversely, laminar flow protects against endothelial dysfunction, at least in the initial phases of atherogenesis. We studied the effects of TNFα and cigarette smoke extract on human coronary artery endothelial cells under oscillatory, normal laminar and elevated laminar shear stress for a period of 72 hours. We found, firstly, that laminar flow fails to overcome the inflammatory effects of TNFα under these conditions but that cigarette smoke induces an anti-oxidant response that appears to reduce endothelial inflammation. Elevated laminar flow, TNFα and cigarette smoke extract synergise to induce expression of the transcriptional regulator activating transcription factor 3 (ATF3), which we show by adenovirus driven overexpression, decreases inflammatory gene expression independently of activation of nuclear factor-κB. Our results illustrate the importance of studying endothelial dysfunction in vitro over prolonged periods. They also identify ATF3 as an important protective factor against endothelial dysfunction. Modulation of ATF3 expression may represent a novel approach to modulate proinflammatory gene expression and open new therapeutic avenues to treat proinflammatory diseases.
    Matched MeSH terms: Shear Strength
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