Applied Mechanics and Materials Vols. 71-78

Abstract: This paper presents an experimental investigation of longitudinally welded aluminum I-section beams subjected to concentrated force. The specimens were fabricated using 6061-T6 heat-treated aluminum. The test program included 10 beam tests contained 2 test series according to different welding section, i.e. T-shape section and P-shape section. The test results were compared with the design strengths predicted by the European Code and the suggested formula in the paper for welded aluminum beams. The purpose of this paper is to present the tests results of two typically longitudinally welded I-section aluminum beams, and to validate the accuracy of the recommended design formula.

Abstract: The Ecological Community Evaluation System (EEWH-EC) of Taiwan was proposed in 2009 and is focused on evaluating the entire community. It is a member of the EEWH family of green building assessment system. The purpose of this study is to introduce the EEWH-EC. The evaluation system includes five assessment categories: ecology, energy conservation and waste reduction, health and comfort, service function, and crime prevention. Communities can apply this system to assess themselves, determine their special characteristics, and use the outcome to implement improvements. The government can utilize the evaluation result to make policies for better and sustainable environments for citizens.

Abstract: Cement-based composites were prepared from rice husk and styrene-acrylic emulsion (SAE) with semi-dry production process. The volume of SAE, the rice husk content and alkali treatment on the properties of the composites were studied. Particle-matrix bonding were observed with scanning electron microscope (SEM). The mechanical test of the rice-husk cement composites proved that SAE is an effective additive for reinforcing the composites, the mechanical properties improved significantly by alkali treatment and adding SAE. the properties can meet the requirement of the china building material standard(JC411—2007) when the content of SAE reached 3%.

Abstract: Recycling of waste concrete is beneficial and necessary from the viewpoint of environmental preservation and effective utilization of resources. The carbon fiber reinforced polymer tendon (CFRP tendon) has been widely used in concrete structures due to its high-strength, lightweight, good erosion-resistance, diamagnetism and anti-fatigue. The compressive behavior of recycled-concrete-segment/lump filled steel tubular columns with inner CFRP tendons are investigated in this paper. The formula of ultimate capacities of the columns under axial compression has been derived based on unified strength theory. Good agreement can be found from the comparison of the analytical results obtained in this paper and experimental data. Parametric studies are carried out to evaluate the effects of intermediate principal stress, mixture ratio of the recycled concrete and reinforcement ratio on the bearing capacities of the columns.

Abstract: Ultra-long highly ordered organic nanowires arrays were in situ self-assembled directly on the silicon substrate over a large area based on solution process. The location and the orientation of the nanowires arrays can be easily tuned and controlled by optimizing the motion of the substrate and the solvent evaporation rate during dip-coating process. By precisely adjusting the motion of the substrate, the length limits for nanowires in array caused by the sticking-slipping motion of the contact line in a concentrated solution have been successfully broken through. The longest nanowires array with a length of around 1000µm was obtained from concentrated solution.

Abstract: This paper presents a method for automatic CAD model reconstruction from 3D laser scanning data. 3D laser scanning is a surveying instrument integrated with various kinds of new high technologies, which operates by non-contact high speed laser measurement. The whole process includes data capturing, noise reduction, sub-sampling and surface reconstruction. Modeling accuracy is analyzed afterwards and finally comes to a conclusion that modeling from 3D laser scanning has a great value in virtual reproduction of the objects. Result shows the efficiency of the method addressed in the paper to mode objects.

Abstract: Tests and the finite element method (FEM) have been used to research the mechanical behavior of floor beams in the new cold-formed steel framing system. A group of 3 floor beams have been carried loading test to obtain ultimate bearing capacity, then finite element models, using plastic shell element and simultaneous considering material and geometric nonlinearity in ANSYS, have been established to analyze the mechanical behavior of floor beams. Finally, the ultimate uniform loads are given for the various specifications of floor beams, for practical engineering design.

Abstract: After the assessment targets on concrete performance of anti-sulfate erosion were optimum designed rationally to be assessment parameters, the course on performance deterioration of concrete was characterized using designed assessment parameters. The results show that, every performance deterioration degree of concrete can be compared on the same coordination axis by assessment parameters. The assessment parameters were applicable the same determination criterion, and the determination principle is simple and convenient. The comparing the deterioration course and sensitivity degree of concrete performance is much easy. It is better to judge concrete performance state that the GHPC performance of anti-sulfate erosion has been assessed with assessment parameter designed in the paper.

Abstract: A new method based on the sorption of the nano-barium strontium titanate immobilized on the silica gel G(GBST) to heavy metal ions, included Mn(Ⅱ), Cu²⁺, Ni²⁺,Co²⁺ and Ag⁺, in waste water. The effects of process parameters such as pH, contact time, regeneration conditions and the effects of common coexisting ions on the ions uptake were investigated. The results showed that the manganese, copper, nickel, cobalt and silver ions studied could be quantitatively retained at a pH value range of 7~9. The adsorption capacities of GBST for manganese, copper, nickel, cobalt and silver ions were found to be 8.2 mg/g, 18.3 mg/g, 4.2 mg/g, 2.2 mg/g and 3.1 mg/g, respectively. The heavy metal ions adsorbed on the sorbent could be eluated completely with diluted HNO₃ solutions. The GBST can be used as an effective adsorbent for the treatment of wastewaters contaminated with manganese, copper, nickel, cobalt and silver ions.

Abstract: A new method for the adsorption and preconcentration of bismuth in urine was described. The methodology combines determined using a hydride generation-atomic absorption spectrometry (HG-AAS) with pre-concentration and separation of the bismuth on the nano-barium-strontium titanate powder coated by dithizone (BST-dithizone). The experimental conditions for the pre-concentration and separation of the bismuth, including pH value of the medium, shaking time, eluent condition and co-existing ions have been investigated. The result showed that the bismuth in urine could be adsorbed on the BST-dithizone. The adsorption percentage was affected by the pH value of medium and shaking time. In the medium of pH 6.0, the adsorption capacity of BST-dithizone to bismuth (III) was 13.4 mg·g^-1 when the shaking time was 10 min. The bismuth adsorbed on the BST-dithizone could be completely eluated by 2 mol·L^-1 HNO₃. The enrichment factor was 100. The detection limit of bismuth (III) was 5.1 ng·L⁻¹.The method has been applied to the pre-concentration and separation of bismuth in the human urine and tap water with satisfied results.