Applied Mechanics and Materials Vols. 716-717

Abstract: Magnesium, as a kind of lightweight engineering material whose reserves is considerable abundant in the earth, is green environment-friendly materials for the 21st century. Magnesium alloys with its proportion of smaller than the advantages of high strength, good thermal conductivity and easy machining, is becoming a hot spot of attention and research. In this paper, the effects of magnesium alloys thermal conductivity and heat diffusivity were analyzed by consulting documents. Researches showed that all effects of the electron or phonon movement had affected thermal conductivity and thermal diffusivity of alloys. Furthermore, the thermal conductivity and thermal diffusivity of rare earth magnesium alloy were summarized by literature data, Researches showed that Add moderate amount of rare earth elements can improve the thermal conductivity and heat diffusivity of magnesium alloys.

Abstract: The electricity load imbalance between day and night of air conditioning greatly affect the power generation cost and safe operation of power grid. Because of the important role in balance the peak and night electricity load, the Cool storage technology more and more attention at home and abroad. A cool storage experimental apparatus with internal melt ice-on-coil was set up, and on which the heat-transfer characteristics have been determined. The experimental results show that:The inlet temperature of refrigerant,when entering the ice storage tank, has an larger influence on the process of cool storage than the flow amount of the cooling medium. It is found by analyzing the process of experiment about storage that the suitable outlet temperature of the cooling medium is 1°C while the flow amount of the cooling medium is 0.274 m³/h. The research results can provide help for the energy-saving design of air conditioning.

Abstract: In operating of a flow battery, a certain flow rate should be maintained in order to guarantee its performance. But the pump consumed power may cause significant losses for the overall battery system. In this paper, a fresh electrical model is proposed for the novel single flow zinc-nickel battery. The model consists of both battery stack part and pump power part, which consequently not only predicts accurately the battery electrical output, but also estimates the pump consumed power at different electrolyte flow rate. Based on the validated model, the influence of pump power on flow battery’s system efficiency can be evaluated at different operating modes. At last, possible means to further improve the system efficiency of battery is discussed.

Abstract: Giant Magnetostrictive material is a new type of rare earth functional material which is after the rare earth permanent magnets, rare earth luminescent material and rare earth high temperature superconducting material. At present, giant magnetostrictive material has become a domestic research hot spot, and made great achievements. In this paper, research and application status on giant magnetostrictive material has been summarized. It mainly includes two aspects: giant magnetostrictive sensors and self-sensing actuator.

Abstract: Graphene (Gn) were prepared by reduction of graphite oxide (GO), which was obtained from oxidation of graphite powder by a modified Hummers method. The composite of titanium dioxide/graphene (TiO₂/Gn) was synthesized using tetrabutyl titanate and GO as the precursors by a sol-gel method. The ozone photodecomposition efficiency of TiO₂/Gn was operated under ultraviolet-visible (UV-Vis, λ>365nm) light irradiation. Results showed that as-prepared TiO₂/Gn composite exhibited photodecomposition efficiency of 66.12% under UV-Vis light irradiation 1h with the initial concentration of 0.150ppm-0.200ppm, preliminary larger than that of pure TiO₂ (25.95%), self-photolysis of ozone without photocatalysts (1.33%). The effects of initial concentration of ozone and photodecomposition mechanism were discussed.

Abstract: Three principal components (cellulose, lignin, and hemicellulose) of coconut shell (CS), an abundant tropical biomass, were quantified using the Van Soest method. It was observed that CS had a high content of hemicellulose (30% of the raw CS material). The present study was undertaken to investigate the extractability of hemicellulose from CS obtained by ultrasound-assisted potassium hydroxide solution with the hydrogen peroxide method. The ultrasonic treatment and sequential extractions with alkali and alkaline peroxide under optimal conditions led to a release of more than 93% of the original hemicellulose. The effects of experimental variables, including pH value, reaction temperature and time, hydrogen peroxide content, and magnesium sulfate dosage on hemicellulose content were investigated. The obtained hemicelluloses were characterized by Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), and comprehensive thermal analysis (TGA), which showed that potassium hydroxide significantly affected the yield of relatively pure hemicellulose.

Abstract: In system of cetyltrimethylammonium bromide (CTAB), tetraethyl orthosilicate (TEOS) and sodium hydroxide, the mesoporous sieves MCM-48 with hetero atom could be synthesized by adding different aluminum and titanium sources. The results showed that M41S family of hexagonal (MCM-41), cubic (MCM-48) and lamellar phase (MCM-50) could be synthesized respectively through hydrothermal method by adjusting the alkalinity in synthesis gel exactly.

Abstract: The refractive index of double-distilled water and inorganic salt solutions of concentrations varying from 0.4 to 100 ppt (‰) have been measured at 20 Celsius degrees using Abbe refractometer, respectively. The inorganic salts such as NaCl, MgSO4, KCl and MgCl2,these forming the major constituents of seawater are used as solutes of the water solution. The effect of the concentration of these constituents on the refractive index of the solution is experimentally investigated. And meanwhile, the index of refraction studies are carried out for the laser wavelength of 405nm, 450nm, 532nm and 633nm under the case of varying concentration. The results show that the refractive index of the solution will be linearly increased with the increase of the concentration of these constituents. The index of refraction differs for the different solutes when their concentration is same at a certain wavelength.

Abstract: The basic study on heat stability of polyphenol oxidase (PPO) from purple sweet potato (PSP) was mainly carried out here. Research on thermal stability showed that PPO from PSP was very sensitive to the changes of temperatures. The optimum temperature of PPO was 16°C with the second optimum temperature of 30°C and PPO activity dropped rapidly when temperature was below 5°C or above 45°C. Half-lives of PPO were 450, 240, 66, 50, 21 and 13s respectively at tested temperatures from 65 to 90 °C at 5°C intervals.

Abstract: Using sweet potato starch, butanol, and dodecyl alcohol as raw materials, the alkyl indican surfactant was synthesized by two-step reactions with composite catalysts of p-toluene sulfonic acid and citric acid, the synthesis conditions were investigated through orthogonal method and the structure of the product was characterized by IR and mass spectroscopy. The weeding test was also studied by adding the appropriate proportion of alkyl indican surfactant. The results showed that the best technological conditions was: reaction took place under 120 C and last for 4 h, m_{sweet potato starch}:m_n-butanol: m_n-dodecanol=m_sp:m_nb:m_nd =1:2:5, the content of composite catalysts was 1.6 wt% p-toluene sulfonic acid and 10.0 wt% citric acid. The weeding test demonstrated that added 1% APG into the glyphosate could killed almost all weeds in five days and had an excellent weeding efficiency. Compared with spraying glyphosate with no APG, which could decrease the amount of glyphosate used and protect the environment.