13This paper applied Particle Swarm Optimization (PSO) in three-dimensional (3D) slope 14 stability analysis to determine the shape and direction of failure as the critical slip surface. A 15 detailed description of adopted PSO was presented and a rotating ellipsoid shape was 16 introduced as the possible failure surface in the analysis. Based on the Limit Equilibrium 17 Method an equation of Factor of Safety (FoS) was developed with the ability to calculate the 18 Direction of Sliding (DoS) in its internal process. A computer code was developed in Matlab 19 to determine the 3D shape of failure surface and calculate its FoS and DoS. Then, two 20 example problems were used to verify the applicability of the presented code, the first by 21 conducting a comparison between the results of the code and PLAXIS-3D finite element 22 software and the second by re-analyzing an example from the literature to find the 3D failure 23 surface. In addition, a hypothetical 3D asymmetric slope was introduced and analyzed to 24 demonstrate the ability of presented method in determining the shape and DOS of failure in 25 3D slope stability problems. Finally, a small-scale physical model of a 3D slope under 26 vertical load was constructed and tested in the lab and the results were re-analyzed and 27 Page 1 of 66 Can. Geotech. J. Downloaded from www.nrcresearchpress.com by MICHIGAN STATE UNIVERSITY on 02/18/15 For personal use only. This Just-IN manuscript is the accepted manuscript prior to copy editing and page composition. It may differ from the final official version of record. 2 compared with the code results. All the results demonstrated the efficiency and effectiveness 28 of the presented code in determining the 3D shape of failure surface in soil slopes. 29 30

The strength of rock is significantly affected by weathering and moisture content. Due to climate conditions in the tropics, rock is weathered significantly and produces a thick weathering profile. Designing structures in rock with varying degrees of weathering creates problems due to varying material properties. This study was carried out to investigate the effects of moisture content on weathered Malaysian granite of various grades, focusing on strength which is an essential parameter in designing engineering rock structures. Weathering identification tests, Schmidt hammer tests, and impact index tests were performed at the site as part of the field study. In the laboratory, samples were analyzed for durability, point load index, moisture content, density, and X-ray diffraction (XRD), and underwent petrographic analysis to examine the mineralogy. The results revealed that the degree of feldspars weathering and the amount of clay minerals are good weathering grade identifiers. The amount of fresh feldspar decreased from 72 % in grade I specimens to 0 % in grade V specimens, with an increase of altered feldspar and clay minerals from 0 to 60 %. The presence of feldspar and mica minerals above 1 % tended to increase the susceptibility of rock to the influence of water. It was also found that the reduction in strength becomes greater with an increasing weathering grade. In addition, the discolouration of rock material from greyish to brownish red also can be a good indicator of strength reduction due to moisture content. Based on the results, the extent of strength reduction depends upon the weathering grade, petrographic constituents and duration of water immersion.

In the past few decades, design development of high performance machines and devices encouraged industries to utilize advanced materials such as polymers. Special mechanical features of polymer materials such as high strength to weight ratio and etc have increased scientists demands to investigate the nonlinear behaviour of polymers. One of the challenges in mechanic of polymers is to introducing a model that is competent to predict hyperelastic deformations based on long-strain behaviour of polymers. In this study, a comprehensive research is performed on introduced mechanical models for polymer materials. The major attempt was on introducing an appropriate model among the existing models, capable enough to predict mechanical behaviour of high density polyethylene under monotonic compressive load. The procedures of simulation and experimental tests are performed to examine the load capability of the model for high density polyethylene. Several compression tests are performed on High Density Polyethylene cubic specimens to extract the full stress-strain response of the high density polyethylene. Moreover, strain gauge is used in experimental tensile test to determine Poisson’s ratio. Simulation procedure is performed using ABAQUS 6.9EF for a comprehensive analysis and discussion on hyperelastic deformation. The simulation procedure is confirmed and verified perfectly by experimental data. The comparison between experimental result of compression test under monotonic load and finite element simulation of this test is remarkable to know about behaviour of HDPE to use in other structural and mechanical application.

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Selective response inversion to NO2 and acetic acid in ZnO and CdS nanocomposite gas sensor D Calestani, M Villani, R Mosca et al. Abstract. This study explores the feasibility of Bacillus subtilis and optimum reagents concentration used in Microbial-Induced Calcite Precipitation (MICP) treatment of tropical residual soil. Experiment was conducted to investigate the effect of cementation reagents concentration toward MICP treatment. The performance of MICP treatment was assessed by measurement of the soil shear strength and calcite content. Based on the experimental results, it is discovered that the cementation reagent concentration has significantly affected on the performance of MICP treatment. The results suggested that the most preferable MICP treatment reagents concentration is 0.25M with the presence of Bacillus subtilis; using these treatment parameters, both UCS value and calcite content of treated soil had increased about 38% and 65.6% respectively. However, the reduction in UCS value was manifested for those samples treated at higher reagents concentration (0.35M); this phenomenon is attributed to the salinity of reagents where high salinity is not favourable to the bacteria growth and microbial activity; subsequently, this resulted in a consequential decrease in shear strength of the treated soil.