Stability limits and consolute critical conditions for liquid mixtures

This work addresses the determination of stability limits and consolute critical conditions for multicomponent liquid mixtures. Using the NRTL model, thermodynamic stability and criticality criteria are implemented for ternary liquid mixtures to predict stability limit loci and critical composition at its specified temperature and pressure. The method is general and applicable for the prediction of spinodal curves and critical points for liquid–liquid-phase transitions in multicomponent liquid mixture using liquid–liquid equilibrium data even over a limited range of composition. Stability limits’ loci for 18 aqueous and 3 nonaqueous ternary liquid mixtures were used in validating the method. For ternary systems that were studied over the whole composition range including the critical zone, where experimental compositions at the critical point were available, the predicted results agree with the experimental measurements within 0.7?mol%.     

Metal concentrations in a shallow groundwater aquifer underneath petrochemical complex

Duplicate groundwater samples were collected from 104 monitoring wells (piezometers) from shallow aquifers underneath an industrial city in the Eastern Province of Saudi Arabia. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V, Zn, Ca, Mg, K, Na, Cl, SO₄, alkalinity, salinity, total dissolved salts, and pH were determined in these samples. Analysis of variance showed significantly (p < 0.05) wide variations in the concentrations of the above parameters. The contour maps of metal concentrations indicated that these variations were related to important landmarks in the study area. The results of correlation analyses suggest that geographical as well as chemical factors may influence metal distribution in the groundwater samples. To investigate the geographical effects, the analytical data were normalized (element/Cl ratios were calculated) for chemical variability. As expected, contour mapping of the ratio data of element/Cl of Na, Ca, Mg, K, SO₄, alkalinity, salinity, total dissolved salts, and Sr vary in a relatively small range and did not show a particular geographical trend. The groundwater sample from the industrial-dust area contained higher ratios between concentrations of Cl and Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, and Zn. These observations clearly suggest an extraneous contamination source, probably industrial dust, in the area. Another geographical area where metal (As, Cd, Cu, Mo, Ni, Ti,and V)/Cl ratios were found to be large was in the vicinity of an oil-refinery. Groundwater samples collected from the vicinity of a fertilizer plant and green-belt area contained relatively higher ratios of Al, Cd, Cr, Co, and Ni. The results of this study suggest that leachate from the industrial dust, leakage from the oil refinery and fertilizer plant, and drainage of irrigation water are some of the important pollution sources in the industrial city.     

Interfacial performance and durability of textile reinforced concrete

The aim of this work is to understand the bonding characteristics between various yarn structures and cement matrix which was studied by yarn pull out test. In this work, the effect of accelerated ageing under alkaline environment for different types of fibers i.e. Basalt, Polypropylene, Polyester, and Jute is studied in order to comparatively evaluate their weight loss and reduction of tensile strength. SEM images are also used for studying the morphology of alkali degraded fibers. Material characterization can also be done by FTIR, XRD, ICP, Zeta potential, and UV spectrometer.     

Development and application of C60-fullerene bound silica for solid-phase extraction of biomolecules

Sample pretreatment is the most important procedure to remove the matrix for interfacing with mass spectrometry (MS). Additionally, for the samples with low concentration, the process of preconcentration is required before MS analysis. We have newly developed a solid-phase extraction stationary phase based on C60-fullerene covalently bound to silica for purification of biomolecules of different characteristics. Silica particles of different porosity are modified with aminopropyl linker and then covalently bound to C60-fullerenoacetic acid or C60-epoxyfullerenes. The developed materials have been successfully applied as an alternative to commercially available reversed-phase materials for solid-phase extraction. C60-fullerene silica is able to retain small and hydrophilic molecules like phosphopeptides, which can be easily lost by reversed-phase sorbents. The novel materials are applied for desalting and preconcentration of proteins and peptides, especially phosphopeptides. In addition, the C60-fullerene silica is applied for the solid-phase extraction of selected flavonoids with recoveries of approximately 99%. The recoveries are compared with the commercially available solid-phase extraction materials.     

测量β放射性活度的TDCR效率计算技术绝对测量方法

利用三管液闪探测系统实现ＴＤＣＲ计数效率计算技术,并完成２０４Ｔ１活度的绝对测量     

利用声波时差资料研究岩石扩散系数的方法

在深入研究影响岩石扩散系数因素的基础上,本语文从和实测数据中确定出岩石扩散系数与其孔隙率之间的相关关系。并通过孔隙率与声波时差之间的相关关系,建立了岩石扩散系数与声波时差之间的函数关系。根据上述关系利用声波时差资料研究了塔里木盆地塔中地区石炭系泥岩扩散系数,其结果表明,该方法不仅可以获取大量的同放散系数值,而且可以把岩石扩散系数的研究扩展一同上。对于准确评价泥岩阻扩散相天然气能力和估算天然气扩散都     

Effect of fish,starch and salt contents on the microstructure and expansion of fish crackers (‘keropok’)

Light microscopy studies on the fish cracker gel and expanded product (‘keropok’) emphasised the role of fish proteins in the starch expansion process. The addition of salt (20 g kg⁻¹) in the ‘keropok’ helped to distribute evenly the starch in the fish protein. Formation of thin fish muscle bundles assisted the expansion of ‘keropok’. At 700–900 g kg⁻¹ fish content, the fish muscle bundles formed a continuous network that caused a drop in the ‘keropok’ expansion. From the scanning electron microscopy study, ridges were found in samples (containing 600–900 g kg⁻¹ fish content) with 20 g kg⁻¹ salt at high magnification. © 1999 Society of Chemical Industry