Advanced Materials Research Vols. 881-883

Abstract: Raman spectra are sensitive to solute, solid or polymorphs concentrations, particle size distribution and temperature. Characteristic peak positions of tibolone and acetone were observed at 1559cm^-1 and 787cm^-1. In this paper, we used the LabRAM HR800 System to detect the Raman spectra of 11 undersaturated standard solutions (concentration range 0-150 mg/ml) at 40°C; built model that estimating concentration of tibolone in acetone solvent by relating peak intensity ratio of the components to the concentration of the solution, and the mean estimated error was only 1.723% in the testing data. The results indicate that this method of estimating concentration is feasible and simple.

Abstract: Electrodeposited environmental and energy-saving electrodeposited copper alloys materials without silver element will be one of the hotspots on the exploitation of the copper matrix electrical contact field. Theoretically expression of Cu, W, Co and Cu-W-Co alloys electrodeposition possibility is thermodynamically analyzed by the potential-pH plots of Cu-H₂O,Co-H₂O and W-H₂O at normal temperature. It is found that Cu, Co can be deposited together in Cu²⁺,Co²⁺ aqueous solution. Cu-W isn’t deposited from it’s Cu²⁺,WO₄^2- aqueous solution, only if Co-W induced deposition under the cobalt ions’ circumstances. So, It is possible that Cu-W-Co alloys are prepared from Cu²⁺,Co²⁺,WO₄^2- aqueous solution by the electrodeposition in the theory and experiment, which will be new method and theory for Cu-W-Co serial contact materials’ preparation.

Abstract: The crystallization kinetics of calcium oxalate (CaOx) was comparatively studied by detecting the change of free Ca²⁺ ions concentration with the reaction time in artificial urine and in saline system. The dynamics equations of CaOx crystallization was r=kc^α, and the average reaction order (α) was 3.3 regardless of the relative suprasaturation degree (RS) of CaOx in the range of RS=10.58~17.53. The average reaction rate constant (κ) was (0.97±0.1)×10⁹ in artificial urine and κ=(3.1±1.8)×10⁹ in saline system, due to the presence of inhibitors to CaOx crystallization in artificial urine.

Abstract: Differential Scanning Calorimeter (DSC) was used to investigate the thermal properties of 2,4-dichlorophenol+2,6-dichlorophenol and 2,4-dichlorophenol+2,3-dichlorophenol binary systems. The experimental results showed that The phase diagram of 2,4-dichlorophenol+2,6-dichlorophenol system was a simple eutectic type with the eutectic point at 294.99 K and 0.6200 mole fraction of 2,4dichlorophenol; The phase diagram of 2,4dichlorophenol+2,3dichlorophenol system was a simple eutectic type with the eutectic point at 291.86 K and 0.5834 mole fraction of 2,4dichlorophenol. Furthermore, the activity coefficients of components in mixtures of 2,4dichlorophenol+2,6dichlorophenol and2,4dichlorophenol+ 2,3dichlorophenol binary systems have been correlated by the Wilson model, respectively.

Abstract: The dynamics of bubble generating in carboxymethylcellulose (CMC) aqueous solution were studied using chaos method. The results show that for low position (P) and gas flowrate (Q_g), the characteristic frequency of axial and radial velocities are both consistent to bubble periodic shear frequency; but for high position, power spectrums are of broad coverage within low frequency range. The magnitudes of radial characteristic peaks increase with gas flowrate. Phase portraits of reconstructed phase space of velocity time series display certain features of chaotic attractor. For low P and Q_g, phase portrait takes on uniform elliptical shape due to liquid periodic motion caused by bubble periodic rising. Whereas for high P and Q_g, the liquid turbulence is reinforced by bubble increasing velocity and large-scale turbulent intensity around bubble increases, consequently, leading to significant compression of phase portrait.

Abstract: Transitions of bubbly to slug flow have been investigated for wide range of flow conditions via visualization technique. The effects of velocities of both phases were examined with variety of combinations and the experimentations were focused on the air-water flow with an industrial scale two-phase flow loop. The results show that the formations of slugs were easy with the increasing gas superficial velocity during a fixed liquid superficial velocity and were difficult when velocity of the liquid phase increases. These transitions were then evaluated using the ratio of velocities of both phases or called the slip ratio and from there a simple flow pattern map was constructed.

Abstract: TG analysis was used to investigate the thermal decomposition of switchgrass, which is a potential gasification feedstock. 10 mg switchgrass sample with the particles between 0.45 and 0.70 mm was linearly heated to 873 K at heating rates of 10, 20, 30 K/min, respectively, under high-purity nitrogen. The Kissinger method and three isoconversional methods including Friedman, Flynn-wall-Ozawa, Vyazovkin and Lenikeocink methods were used to estimate the apparent activation energy of switchgrass. With the three isoconversional methods, it can be concluded that the activation energy increases with increasing conversion. The four model free methods reveal activation energies in the range of 70-460 kJ/mol. These activation energy values provide the basic data for the thermo-chemical utilization of the switchgrass.

Abstract: Dodecyl trimethyl ammonium bromide/sodium dodecyl sulfate (DTAB/SLS) complex formulation of scale effect on the spontaneous formation of vesicles and the influence of different factors on the stability of vesicles were discussed, structure and morphology of vesicles were observed.

Abstract: Food preservative materials are indispensable for food commercialization. As serious side effects of chemical food preservative materials, new natural materials are central issues. Honeysuckle, a natural herb which is used as a clear away heat and toxic material in Chinese traditional medicine has activities of antibacterial, antiinflammatory, antiviral, antioxidant, anticancer and so on. It may be an potentially promising preservative material. Different varieties, different processing methods and different solvents were experimented by disk diffusion method, as a result, ethanol extract of Julu Honeysuckle was a best choice.

Abstract: The salt-tolerance lactic acid bacteria strain was isolationed and identified from soy sauce mash. The ability producing lactic acid was studied in different culture conditions. The salt-tolerance lactic acid bacteria strain was isolationed and screened by MRS medium with CaCO₃ and NaCl gradient plate from soy sauce mash. They were identified according to morphorlogy characters and 16S ribosomal RNA (rRNA) gene sequencing methods. The ability producing lactic acid was studied at different fermentation temperature, NaCl concentration and pH value. The results showed: the strain with superior salt-tolerant was identified as Lactobacillus delbrueckii subsp. bulgaricus. Its optimum fermentation temperature was 38°C. When NaCl concentration was 18%, its lactic acid yield could reach 22.68 g/L. It had a better absorbing ability of lactic acid in neutral or slight alkaline condition.