Advanced Materials Research Vols. 335-336

Abstract: The magnesium slag is discarded from production of magnesium metal from dolomite. However the magnesium slag is slaked in some factories by means of sprinkling water to prevent from dust pollution. The possibility of slaked magnesium slag (SMS) to play a role of raw material and blend for portland cement was investigated by experiments of raw mix preparation, clinker calcining and property determination of cement pastes and mortars. The results revealed that SMS was still reactive. The raw mix with SMS was of excellent burnability that would contribute to energy saving. As a raw material, SMS can be used for calcining clinker of good quality; and as a blend it is suitable for production of ordinary portland cements. Because the magnesium slag is slaked, SMS has no problem on soundness. Higher strength of cement can be obtained in form of binary blends consisting of SMS and ground granulated blast-furnace slag or fly ash.

Abstract: A novel Na₂O-K₂O-CaO-MgO-SrO-B₂O₃-P₂O₅ borophosphate glass is prepared by melting method. The thermal properties have been examined by differential thermal analysis (DTA) and viscosity measurement. The bioactivity of the glass is measured via soaking the glass in the SBF solution at 37 °C for different time. The reaction of the glass in the SBF solution is characterized by XRD, FTIR and SEM. The results indicate that the carbonate hydroxyapatite deposit on the glass in less than 7 days. Cell attachment, spreading and proliferation on the glass is determined by MTT [3-(4, 5-Dimethylthiazol-2-yl)-2, 5-Diphenyltetrazolium Bromide] assay method using Human osteosarcoma MG-63 cells. The borophosphate glass fiber is also drawn and the tensile strength is measured. The results suggest the borophosphate glass has a good potential to be a scaffold material for bone tissue engineering.

Abstract: Coal-water slurry （CWS）dispersant is a key to prepare fine coal-water slurry. A novel amphoteric polycarboxylic (AmPC) dispersant for CWS was copolymerized in aqueous solution by comonomers methacrylate polyglycol monoester (PA), propylene sulfur sodium (SAS) and cationic comonomer methacryloyloxy ethyl trimethylammonium chloride(DMC).Methacrylate polyglycol monoester was prepared by direct esterifying with methacrylate acid (AA) and polyethylene glycol (PEG) in our laboratory. And then, The molecule structure of amphoteric polycarboxylic dispersant was characterized by FTIR. Besides, the dispersant was applied in Shenfu coal slurry. Through examining properties of the coal slurry, the effects of amount of cationic monomer DMC, the concentration of initiator and reaction temperature on dispersant performance were discussed. The result shows that the viscosity reducing of amphoteric polycarboxylic dispersant is better than the dispersant in stock which hasn’t cationic monomer when the dosage of DMC is 5.0wt%. It has been proved that the amphoteric polycarboxylic dispersion agent is suitable for Shenfu coal slurry. When the dosage of AmPC dispersant is up to 0.5wt%, the highest concentration of coal-slurry can reach 65.4wt%.

Abstract: Modifications of the interfacial electrical characteristics of kaolin were investigated through reversing particles surface charges induced by organic cationic polyelectrolyte and natural anionic organic substance. Zeta potential and rheology tests indicated that polymeric OH-Al reversed the edge charges and reached a saturation adsorption on kaolin surface at dosage of 45μmol/g, corresponding to a lower viscosity of kaolin suspension, as a result of the combined action of OH-Al modified positive particle surface and negative charges from sodium hexametaphosphate dispersant. A significant reduction in viscosity of kaolin modified by gallic acid was also observed in either dilute or concentrated suspension. The strong interaction of OH-Al ions with clay greatly increased the gallic acid adsorption, and resulted in the lowest viscosity for modified kaolin, indicating the bound of gallic acid to the reactive surface sites induced by OH-Al. It can be concluded in this experiments that the highly charged organic coating play a role in the dispersion of kaolin particles.

Abstract: The microwave magnetic dynamic properties of the [NiFe(40nm)/IrMn(15nm)]₆/[NiFe(30nm)/IrMn(15nm)]7/[NiFe(20nm)/IrMn(15nm)]₁₀ multi-stacks structure films, prepared by high vacuum DC magnetron sputtering deposition, have been investigated at the frequency range from 10 MHz to 6 GHz. By changing the thickness of the ferromagnetic (FM) NiFe layer in bottom [NiFe(t nm)/IrMn(15nm)]₆ stack part, a tunable lower frequency range used magnetic multilayer can be realized. The influence of the NiFe layer thickness in bottom stack to static and dynamic magnetic properties were obtained and analyzed. Combining with the top [NiFe(30nm)/IrMn(15nm)]₇/[NiFe(20nm)/IrMn(15nm)]₁₀ two stacks used in the higher frequency, a kind of multi-stacks structure magnetic thin films were fabricated for the wideband microwave noise filter.

Abstract: In semiconductor factories and electronics factories, a large multi-chiller system is needed to satisfy strict cooling load requirements. In order to save energy, it is worthwhile to design the chilled water system operation. In this paper, a design methodology is developed for multi-chiller system in which chiller units consist of different cooling capacities chiller that run in parallel. The optimal design problem can be expressed as a mixed integer nonlinear programming (MINLP) which minimizes the system energy consumption within a future time period. In order to solve this complex problem, the two-stage strategy is employed to divide the problem into a scheduling stage and an operating stage. Instead of a lag scheme obtained with general method, this forecasting scheme consists of a series of optimal scheme at each sub-time period and can offer operating reference for operator. The effectiveness of the proposed method is illustrated by an industrial case

Abstract: It is well known that there are some similarities among various naturally occurring amino acids. The standard amino acids have been grouped by their general properties and the chemical structures of their side chains. In this paper we divided the molecular weight of amino acid into two parts: backbone molecular weight M_b and side chain molecular weight M_s. We naturally grouped the amino acids into two sets according to the rate of M_s / M_b. We developed a method to construct a syntheses table to reflect the relevant physicochemical properties based on the PAM250 matrix and successfully established an elegant table of the twenty amino acids. Our work proved that PAM250 matrix could be used not only in finding reasonable alignments but also in grouping similar amino acid.

Abstract: UMo/Al dispersion fuel is one of the prospective materials as a high uranium density fuel for high performance research reactors due to its excellent stability during irradiation. In this paper, An overview is provided of current development activities of UMo/Al dispersion fuel at abroad and home, including: the development reasons, this fuel fabrication technology, and the irradiation test. A comprehensive summary is given on the irradiation test, the existing problems and the solution recently obtained by the different countries. Early irradiation experiments with uranium alloys showed promise of acceptable irradiation behavior if these alloys could be maintained in their cubic γ-U crystal structure. The further development of this fuel was delayed due to an unacceptable volume expansion caused by UMo/Al interaction layer (IL) formation and a subsequent gross pore formation at the interface between UMo particles and matrix Al when severe irradiation conditions are reached. In order to alleviate or eliminate the swelling of UMo/Al dispersion fuel,several potential remedies are available to correct the swelling problems. These range from relatively minor changes to the fuel and matrix chemistry, to replacement of the aluminum matrix with another material, or to eliminate the matrix altogether. All of these variations are currently being investigated in the world.

Abstract: A technology of self-emulsification coacervation to prepare starch sodium octenyl succinate (SSOS) microcapsules consisting of evening primrose oil (EPO) as a core material has been illustrated in this report. The optimal microencapsulation conditions has been investigated and the morphology of the microcapsules has been observed by Optical microscope. The results show that the optimized microencapsulation condition is core-wall ratio 2 g/g , DS 0.050, coacervating agent 0.8 mL/mL emulsion, with the cross-linker 0.04 g/g SSOS, stirring speed 700 rpm for emulsification, and 350 rpm for coacervation. Meanwhile，the protective effect experiments via aeration method indicate that the increment of peroxide value (POV) of entrapped EPO is only 5.68％ compared to unencapsulated EPO after aeration for 48 h, which shows good protection performance of SSOS microcapsules to entrapped substances.

Abstract: The effects of Amide type nucleating agents SX , talc and nucleating agents SX combination with talc on crystallization behavior of poly (L-lactic acid）(PLLA) were analyzed by means of Differential scanning calorimetry (DSC)．The results of non-isothermal crystallization showed that SX is an efficient nucleating agent. The crystallization peak temperature and degree of crystallization of PLLA sample with 0.6 wt% SX are both higher than that of PLLA sample with 4 wt% Talc，which proved that the nucleating ability of SX is stronger．Nucleating agent SX and talc combination has obvious coordination effects, the sample of PLLA/0.2 wt % SX + 4 wt % talc has the minimal crystallization undercooling temperature, the highest crystallization peak temperature and crystallinity. Isothermal crystallization kinetics of PLA showed that when the four nucleating agents added in are all with the Avrami exponent n between 2.1-2.5, crystallization tended to be heterogeneous nucleation. When the nucleating agents added in are 0.6 wt%, the crystallization time is greatly decreased to 0.75min. Meanwhile, the PLLA crystallinity could be significantly increased by adding SX nucleating agents; besides, with the decrease of the isothermal crystallization temperature, the half crystallization time of the PLLA/0.6 wt% SX sample was decreased.