Advanced Materials Research Vol. 660

Abstract: The direct conversion of propane and butane fraction (existing as mixtures rather than separate products) to methanol as well as the reaction mechanism under visible light source (λ=420 nm) and the catalytic action of •NO2 have been evaluated. The purpose of this work is to explore novel pathways for the production of methanol by suggesting a simplified model and result-oriented scheme to avoid the drawbacks associated with methane activation (incredibly high activation energy of about 440 kJ/mol even under mild processing conditions) in the course of its transformation to methanol which is characterized by high yield and selectivity. It is important to consider propane and butane fraction (recovered from primary crude oil distillation and by cracking of heavy molecules) as a possible feedstock for methanol production exhibiting a sufficiently high degree of conversion per pass. Thereby, a relatively simple and economical method for methanol production from refined crude oil composed of propane and butane (a one step co-processing) have been tendered.

Abstract: We present the study of the electrical contact properties of monolayer MoS2/Si in terms of semiconductor heterojunctions theory. It shows that the carrier concentration increases in exponential form with temperature, then gradually arrived to its saturation. Additionally, the energy band structures of monolayer MoS2/n, p-Si heterojunctions have been developed before and after contacting. And the work functions of MoS2 and Si, barrier height of the junctions have been investigated. The barrier height linearly increases with the carrier density in Si. Finally, we simulated the voltage-current property of the monolayer MoS2 /n, p-Si heterojunctions in terms of thermal diffused theory of semiconductor.

Abstract: Half-heusler TiCoSb1-xSnx (0.00≤x≤0.05) alloys were prepared by mechanical alloying of elemental powders, and consolidated by vacuum hot pressing. Sn doped half-Heusler phases of TiCoSb was successfully produced in all doping ranges by vacuum hot pressing using as-milled powders without subsequent annealing. However, a little fraction of CoSb phase appeared after hot pressing. Thermoelectric properties as functions of temperature were evaluated for hot pressed specimens. Seebeck coefficients showed to change in conductivity by doping and the absolute value revealed relatively low. It is shown that electrical conductivity is relatively high and thermal conductivities are compatibly low. Sb doping up to x=0.02 in TiCoSb1-xSnx was shown to be effective on thermoelectric properties in this study.

Abstract: Currently companies seek performance improvement for equipment and components, and an important factor that influences performance is wear. The objective of this study was to demonstrate the applicability of a methodology that was developed using literature, field research, brainstorming, optical microscopy, statistical analysis.Wear tests for drilling crown samplesfor the production process were performed. - The crown’s chemical composition was analyzed to see if it was appropriate for the soil’s mineral lithology. Having done this, a statistical analysis was made. using Minitab 16 software, specifically applying DOE (2Kfactorial) technique. With the statistical result, a prototype was produced and subjected to a wear test for analysis of material loss compared to crowns having a better performance.Thus, the conclusion reached was that the planning process improves withthis experimental probing, which helps to identify and correct controllable factors.

Abstract: A torsional vibration mechanical model of the transmission system of a certain cetarpillar vehicle is established using mass distribution method. The torsional vibration model, containing multi-stage simple and compound planetary gear transmissions, fixed-axis transmission and power split/converge system, is established based on Lagrange Equation. Matlab is used for presenting and writing the according program of the modal analysis of free torsional vibration. The study is focused on the torsional vibration characteristic of the system on one specific working condition and the similarity in the inherent characteristics of the system on different working conditions.

Abstract: In this paper is compared residence times of tundish equipped with Turbostop and tundish equipped with experimental swirl chamber. Set of measurements in this paper was performed in the Laboratory simulated flow processes (LSSP). Water model is assembled at scale 1:3 to original. Measurements were evaluated by graphical measuring of water conductivity variation at tundish inlet and outlet by adding potassium chloride into tundish inlet and visually where KMnO4 was used as an indicator.

Abstract: This article has discussed the energy saving in iron-steel industry in our country, faced to typical special of the production logistics process in iron-steel enterprise, improved the physical distribution model of the production logistics process in iron-steel enterprise, designed it’s key-points that is possible arranging dispatching routing, then according to most in-out domestic specialist establishes the logistics model that has time window constraint and can be visited many times by customers. Needed to its. Through the simulation case, it indicated that the distribution cost of the model which can be visited many times is less than that of witch can’t be visited many times. Arrived at the less cost and most efficient, it is an important value that theoretical and practice.

Abstract: The plastic packaging accounts for great proportion in the packaging industry, resulting in great confrontation and challenge for global carbon reduction development because of the plastic packaging wastes (PPW) generation. Thus the fully reasonable utilization of the PPW presents a positive strategy. Based on the international practical policy and demand of PPW management, the article classified the recycling and separation technology, and the reuse and utilization disposal approaches of the PPW. Firstly, it defined the PPW’s source, classification and chemical composition, focusing on the recycling and separation technology principles and practices. Then it discussed several PPW disposal approaches emphasizing on the recycling, and summarized the principles and practices of mechanical recycling, chemical recycling, and energy recycling and biodegradable utilization on the PPW. Finally, it presented a suggestion on recycling and utilization of PPW.

Abstract: Concrete surfaces are becoming increasingly popular in road construction around the world. This is due to a number of advantages, such as high durability amounting up to 40 years, high load capacity, resistance to rutting at high temperatures, and light color which allows for reduction of costs of lighting. This paper presents a new method of constructing a disc for concrete surface floating. On the basis of numerical calculations a nomogram has been designed which can serve for selecting the optimal disc’s geometrical parameters of required geometric efficiency of a working tool’s influence based on the criterion of uniformity of processing (Sg). In the case of the analyzed geometry an increase of the required geometric efficiency the minimum value of the standard deviation and standard deviation ratio increase accordingly, which is the measure of processed surface uniformity, which is it leads to quality deterioration of machining.

Abstract: To obtain the pressure distribution model on the sole plate of semi-rigid light steel column footing, the deflection formulas of beams with free ends on elastic foundation subjected to arbitrarily concentrated load and arbitrarily trapezoidal load were developed by applying the Winkler model of elastic foundation beam and initiate-parameter expressions of deformation and internal force by presetting boundary condition and calculating with Maple software. The sole plate of semi-rigid square steel tube column footing was converted into elastic foundation beam which is supported by concrete foundation, the mechanical model of the sole plate subjected to eccentric load was obtained, and the theoretical solution of pressure distribution on the sole plate was presented. Then the theoretical solution was compared with the numerical solution via an example. The results show that the two solutions meet well with each other, and there is much great difference between the pressure distribution on sole plate of semi-rigid light steel column footing and the linear pressure distribution model in common use. As a result, the semi-rigid column footing stiffness would be overestimated by using linear pressure distribution model. The fruits presented in this paper are useful and convenient to the design of semi-rigid light steel column footing.