Advanced Materials Research Vols. 807-809

Abstract: The effects of various input parameters on the warpage of strip were investigated and discussed. Three theoretical techniques, including virtual layers method (VLM), energy balance method (EBM), and finite element method (FEM), were adopted to evaluate the distributions of plastic strain, temperature, and stress of the strip, respectively. The longitudinal residual warpage can then be calculated accordingly. It was found that the cooling condition in cooling section plays a key role on the residual warpage of strip, which is possibly to be controlled within an accepted range by applying a suitable cooling scheme in this section.

Abstract: PM_2.5 has serious harm to human health and the environment, coal-fired power plant flue gas emission is one of the important sources of PM_2.5, however dust removal equipment for PM_2.5 and finer particulate collection efficiency is very low.Mixed dust removal technology have various problems such as cost increasing , complex operation, the material requirements and capture efficiency of fine particle is not obvious. Coagulation as an effective method of collecting sub-micron particles, has good prospects for development.Further study of the mechanism of coagulation and coagulation technology in practical application of industrial production became focus of future research.

Abstract: PANI nanofibers with a really nanoscaled diameter of 20 ~ 30 nm and a high conductivity of 10⁰ S/cm were successfully prepared by using FeCl₃ · 6H₂O as oxidant at the acidic dopant-free. Compared with other synthetic methods for nanostructures, this approach is most simple and cheap because of FeCl₃ · 6H₂O having two-function of oxidant and dopant at the same time, resulting in further simplifying reaction reagents. Characterizations of UV-visible, FTIR spectra, XRD as well as conductivity measured by four-probe method definitely proved the nanofibers oxidized by FeCl₃ as oxidant at dopant-free are identical to the emeraldine salt form of PANI, although without external acidic dopant, and Cl^- anion is incorporated the PANI main chain as counter-ion.

Abstract: Successful acid fracturing stimulation in carbonate reservoirs largely depends on the acid etched fracture conductivity. However, accurate prediction of this parameter is difficult due to the lack of knowledge for delicately charactering rough fracture surface. To push the limitation of the current situation, an advanced mathematical model is proposed based on the fractal theory and previous models. Matlab software is employed for generating rough surfaces with two variables, standard difference and fractal dimension. A partial differential equation is built to describe the fluid flow between two random fractal surfaces and finite element method is chosen to do simulation job. Comparative analysis of the flow ability between fractal surfaces and parallel plates is clarified at the final. The results show that fracture widths have the most influence on the conductivity, followed by fracture surface asperities. Moreover, fractal dimension and standard deviation, can also affect the fluid flow ability.

Abstract: Processes of extracting calcium from the calcium carbide residue by the liquid-state method with propionic acid were studied, and in order to find optimal craft, the orthogonal array was devised. Results of chemical analyses showed that the extracting calcium yield was 93.4%. The purity of product prepared by this process was 97%, in addition, the whiteness of product was 98.6 and the product could reach the standard of HG/T 2567-2006. The IR spectroscopy and TGA provided evidence to support the existence of the propionic acid unit coating the outside of the calcium carbonate particle. The SEM image proved that the morphology of calcium carbonate was spherical. The DLS confirmed that the diameter of the calcium carbonate particle was about 2.5 μm.

Abstract: Transesterification of dimethyl 2,6-napthalene dicarboxylate with ethylene glycol over metal salts catalyst was empolyed as probe reation. The effects of reaction temperature, reaction time, the molar ratio of ethylene glycol to dimethyl 2,6-napthalene dicarboxylate, N2 flowrate, kind of metal salt on the conversion of dimethyl 2,6-napthalene dicarboxylate have been investigated. The results showed that the sequence of influence was as follows: reaction temperature > reaction time > ethylene glycol/dimethyl 2,6-napthalene dicarboxylate molar ratio > amount of the catalyst. The optimum reaction conditions were 210 oC of reaction temperature, 240 min of reaction time, 2.8 molar ratio of ethylene glycol to dimethyl 2,6-napthalene dicarboxylate, 60 ml/min of N2, amount of zinc acetate being 0.08 % / mole of dimethyl 2,6-napthalene dicarboxylate.

Abstract: In this work, the effect of the salt hydrated phase change material (PCM) on microstructure and heat conduction of the autoclaved aerated concrete (AAC) was studied. The microstructure in the AAC and AAC with composed phase change material was imaged by scanning electron microscopy (SEM). The ability in heat conduction was compared among AAC (AAC1), AAC with composed phase change material (0.417 (AAC2) and 0.833 (AAC3) kg/m² in contents), and AAC which was composed by PCM (0.417 (AAC4) and 0.833 (AAC5) kg/m² in contents) and was coated by the cement in 2 sides. These ones were tested the thermal delay at 40, 50 and 60 °C using the heater that was the thermal source. It was found that the optimum content of PCM on top surface was found at 0.417 kg/m² because the minimum heat conduction and the lowest average temperatures of inside wall and inside room were shown in this sample at 40, 50 and 60 °C.

Abstract: This research studies about the possibility of Phase change materials for development with the double roof system which uses the Radiant barrier to reduce the heat into the house and to reduce load of the air conditioner. The experiment was divided into 4 patterns. The Radiant barrier and the Phase change materials are on top of the air passage (model 1). The Phase change materials and the Radiant barrier are on top of the air passage (model 2). The Radiant barrier is under the roof and the Phase change materials is under the air passage is (model 3). The Radiant barrier is under the air passage and the Phase change materials is under the roof (model 4). By building the test room sizes 90x90 cm² and the air passage sizes 10 cm. The heat source from the heat generator in temperature is 45, 50, 60. The results revealed that if the Radiant barrier is under the roof and the Phase change materials is under the air passage, temperature will tend to decrease by the heat transmission into the house decrease about 3-5 in the experiment. The above-mentioned decrease of the temperature, the calculation of the thermal energy per unit area in (model 3) can decrease the most quantity of heat flux more than the other patterns by average at 19.66, 22.5 and 29.14 W/m2 respectively. From the experiment was found that (model 3) has the appropriate position for development more than the other patterns.

Abstract: Kieserite (MgSO₄·H₂O) which has great application in recent years, was prepared according to the binary system MgSO₄H₂O at 80°C and the ternary system MgCl₂MgSO₄H₂O at 25°C, 50°C and 75°C phase diagrams in this research. We reveal that the pure MgSO₄·H₂O is acquired in the ternary system MgCl₂MgSO₄H₂O at 75°C with MgCl₂ (23.966%~37.93%) for the equilibrium time 5~7days. The higher hydrated magnesium sulfate can be obtained in the ternary system with MgCl₂ (0~34.52%) at 25°C, (0~35.684%) at 50°C, and (0~23.966%) at 75°C for 5~7days. These results are beneficial for the industrial production by converting MgSO₄·7H₂O and MgCl₂·6H₂O which are not fully exploited in salt pans into the useful MgSO₄·H₂O.

Abstract: PrFe₄P₁₂ shows an anomalously phase transition from a heavy fermion (HF) state to a non-magnetic ordered state. We prepared single crystal sample of Pr (Fe_1-xCo_x)₄P₁₂ by Sn-flux method to investigate the effects of electron doping. The distinct change of magnetic property was observed. The phase transition of PrFe₄P₁₂ rapidly disappears when doped rate x=0.03. This result indicates that the d-electron plays an important role in formation of Low-temperutre phase and HF state of PrFe₄P_12.