Applied Mechanics and Materials Vol. 618

Abstract: Ultrasonic polymerizations at various wave frequencies of 5-20 kHz were used to synthesize polyaniline (PANI) nanofibers. PANI was synthesized using hydrochloric acid (HCl) as a dopant and ammonium persulfate (APS) as an oxidant. The characteristics of PANI based on molecular structure of functional group and morphology were characterized by fourier transform infrared (FTIR) and transmission electron microscopy (TEM). TEM images of PANI nanofiber show a long nanofibers structure with average diameter of ~25 nm. The FTIR spectra were in acceptable range and confirmed the successful formation of PANI. In this study, the polymerization at frequency wave of 20 kHz shows the best overall properties of produced PANI nanofiber.

Abstract: This paper presents artificial neural network (ANN) predictions for a nanofiltration membrane used to treat wastewater of welding electrode manufacturing in a cross flow set up. The main parameters were time, feed flow rate, and transmembrane pressure (TMP). The experimental data were correlated and analyzed using ANN. ANN’s prediction of the permeate flux, turbidity, total dissolved solids (TDS), hardness for various TMPs, and flow rates are discussed. The effects of the training algorithm, neural network architectures, and transfer function on the ANN performance, as reflected by the percentage average absolute deviation, are discussed. A network with one input layer, 50-100 hidden layers, and one output layer is found to be adequate for mapping input–output relationships and providing a good interpolative tool. A good agreement has been obtained between the ANN predictions and the experimental data with a deviation below 2% for all cases considered.

Abstract: The paper deals with the necessity to develop and apply quantitative methods to the process of sorting and systematization of physics’ content, when future engineers are training physics. Consistency of the information theory’s methods and processes of the human’s information perception is emphasized. The sense structure of a physical term and graph of such structure, which are based on the information model of intra-subject connections, are given. It is shown that, using the sense structure graph of a physical term, the information characteristics of such term may be calculated. Nanoelectronics developes very fast, and students need to study many different disciplines. On the base of these characteristics we can fixed the information limitations to escape students overloading.

Abstract: Zinc oxide (ZnO) is recognized as one of the most attractive metal oxides because of its direct wide band gap (3.37 eV) and large exciton binding energy (60 meV), which make it promising for various applications in solar cells, gas sensors, photocatalysis and so on. Here, we report a facile synthesis to grow well-aligned ZnO nanorod arrays on SnO₂: F (FTO) glass substrates without the ZnO seed layer using a Galvanic-cell-based method at low temperature (<100°C). CdS quantum dot thin films were then deposited on the nanorod arrays in turn by an effective successive ionic layer adsorption and reaction (SILAR) process to form a ZnO/CdS core-shell structure electrode. Structural, morphological and optical properties of the ZnO/CdS nanorod heterojunctions were investigated. The results indicate that CdS quantum dot thin films were uniformly deposited on the ZnO nanorods and the thickness of the CdS shell can be controlled by varying the number of the adsorption and reaction cycles. The number of quantum dots layers affects on photovoltaic performance of the ZnO/CdS core-shell nanorod arrays has been investigated as photoanodes in quantum dots sensitized solar cells.

Abstract: based on Density Functional Theory, we investigated the electronic structures and the optical properties of Sb doped SnO₂ with density of 12.5%.including band structure ,the density of state (dos),dielectric function and optical absorption spectrum. The results show that Fermi level access valence band gradually with the doped density. And this can attributed to the increased folded state. Which have enhanced the electrical and metal property of material ;The peaks of absorption Spectrum and dielectric spectrum correspond, Optical absorption edge decrease and the absorption peaks show blue shift.

Abstract: In this paper, TiO₂/modified expandable graphite composite material was prepared through sol-gel method with the carrier of modified expandable graphite.The influence of this composite material prepared in different calcination environment and with different times of load on the effect of methyl orange solution’s photocatalytic degradation was studied. Results show that the photocatalytic effect is better by using the composite material with the same times of load in aerobic calcination than that in anaerobic calcination. In the same calcination environment, the photocatalytic effect with 5 times of load is better than that with 1, 2, 3 and 4 times of load. Whether in the aerobic calcination or in the anaerobic calcination, the photocatalytic effect is better if the composite material is loaded 5 times.

Abstract: Results of preparing expandable graphite through Microwave Expansion method with the material of expandable graphite made through the Chemical Oxidation process show that in the temperature range of 700°C~900°C, the volume of expandable graphite will bigger with the rise of temperature, reaching the maximum 203 ml/g at the temperature of 900°C. The expandable graphite of 900°C can be modified in 0.5M hydrochloric acid; at the temperature of 40°C and 6h later, decolourization ratio of methyl orange will reach 95%. If the graphite is modified in concentrated nitric acid with the temperature of 50°C for 6 hours, the decolourization rate will be 96%. In terms of cost, it is more economical to modify expandable graphite in hydrochloric acid.

Abstract: The poplar is largest plantation tree species of in China. However, poplar veneer is easily broken when subjected to drying for plywood. This work presents an orthogonal test to reveal the key technological parameters of poplar veneer with high moisture content (MC) on the bonding properties. The results showed that, veneer MC has a significant effect on internal bond (IB) and MC of obtained plywood, but has a light effect on the content of released formaldehyde. Resin content has a significant effect on IB, MC and content of released formaldehyde. Hot-press time has a significant effect on content of released formaldehyde; but has a light effect on MC and IB. The obtained optimal technological parameters of poplar veneer with high moisture content is, veneer MC of 26%, resin content of 11%, and hot-press time of 200s.

Abstract: The porous structure of Semeytau natural zeolite field, catalysts on its basis, and their catalytic activity in the course of aromatization of n-octane has been investigated. Higher activity of Ni, the Zn sample containing catalyst is defined by formation by more developed specific surface and porous structure.

Abstract: nanomicron fiber of Tb (phen)L₃/poly (methyl methacrylate) (PMMA) was successfully prepared by electrospinning using ethyl acetate (EA) and N,N-dimethyl-formamide (DMF) as the solvent. The influence of collector distance, feed rate, applied voltage and the proportion of EA/DMF on the morphology of the as-prepared fibers were discussed. Based on the researched results, the nanomicron fibers with glazed surface and uniform distribution were prepared. The fluorescent spectra indicate that the nanomicron fibers have good fluorescent properties.