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Liquid Ratio (liquid + ratio)
Selected AbstractsGeothermometry and geobarometry of overpressured environments in Qiongdongnan Basin, South China Sea,GEOFLUIDS (ELECTRONIC), Issue 3 2003Honghan Chen Abstract We demonstrate the use of PVT fluid inclusion modelling in the calculation of palaeofluid formation pressures, using samples from the YC21-1-1 and YC21-1-4 wells in the YC21-1 structural closure, Qiongdongnan Basin, South China Sea. Homogenisation temperatures and gas/liquid ratios were measured in aqueous fluid inclusions, and associated light hydrocarbon/CO2 -bearing inclusions, and their compositions were determined using a crushing technique. The vtflinc software was used to construct P,T phase diagrams that enabled derivation of the minimum trapping pressure for each order of fluid inclusion. Through the projection of average homogenisation temperatures (155, 185.5 and 204.5°C) for three orders of fluid inclusion on the thermal-burial history diagram of the Oligocene Yacheng and Lingshui formations, their trapping times were constrained at 4.3, 2.1 and 1.8 Ma, respectively. The formation pressure coefficient, the ratio of fluid pressure/hydrostatic pressure established by PVT modelling coupled with DST data, demonstrates that one and a half cycles of pressure increase,discharge developed in the Yacheng and Lingshui formations for about 4.3 Ma. In comparison, the residual formation pressure determined by 2D numerical modelling in the centre of LeDong depression shows two and a half pressure increase,discharge cycles for about 28 Ma. The two different methods suggest that a high fluid potential in the Oligocene reservoir of the YC21-1 structure developed at two critical stages for regional oil and natural gas migration and accumulation (5.8 and 2.0 Ma, respectively). Natural gas exploration in this area is therefore not advisable. [source] The effect of temperature on viscosity of root canal sealersINTERNATIONAL ENDODONTIC JOURNAL, Issue 11 2006S. Lacey Abstract Aim, To test the hypothesis that there was no significant (, = 0.05) change in viscosity of commercially available root canal sealers with increase in temperature using a high-performance Advanced Rheometric Expansion System (ARES) rheometer. Methodology, Materials tested were Apexit, Tubliseal EWT, Grossman's, AH Plus and Ketac-endo. Cone-and-plate geometry was used (25-mm diameter, 0.1 radian and gap 0.051 mm). Measurements were carried out for steady-state viscosity at 25 and 37 °C in the shear rate range of 0.001,50 s,1 at standardized relative humidity and within 30 min from the start of mixing. Five samples were taken for each sealer at each temperature. Results, At 25 °C all sealers demonstrated shear thinning. At 37 °C Grossman's (powder : liquid ratio 2 : 1 and 3 : 1) and Ketac-endo had a rapid rise in viscosity and early set whereas the other sealers were shear thinning. On increasing temperature from 25 °C to 37 °C, Apexit, Tubliseal and AH Plus had reduced viscosity whereas Grossman's 2 : 1, Grossman's 3 : 1 and Ketac-endo had increased viscosity, which varied with the shear rate. The change in viscosity with change in temperature was significant (P < 0.05) for all sealers except AH Plus. Conclusions, There was a variation in the effect of increasing temperature on each sealer depending on the shear rate. With the exception of AH Plus, a significant (P < 0.05) change in viscosity was found, and the null hypothesis was rejected. [source] The removal of colour, carotene and acidity from crude olive oil by using sepioliteINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2007Mehmet U, urlu Summary The capacity of sepiolite to adsorb colouring matters in olive oil was studied. The effects of adsorption time, temperature and solid:liquid ratio were selected as parameters. The effect of bleaching of olive oil was evaluated for determining the % free fatty acid (FFA), % bleachability and residual carotene by using both thermally activated sepiolite (AS) and acid-activated sepiolite (AAS). Results reveal that thermally acid-activated sepiolite was more efficient than thermally activated sepiolite. The adsorption equilibriums of carotene and FFA on AS and AAS were described by the Freundlich models. A higher adsorption coefficient (K) was observed for AAS (Kcarotene = 2.73 × 10,3mgg,1, KFFA = 0.98mgg,1) compared to AS (Kcarotene = 2.63 × 10,7mgg,1, KFFA = 0.21mgg,1). Moreover, the rate constants obtained for carotene and colour by using AAS (kcolor = 0.0241 min,1, kcarotene = 0.0217min,1) were higher than that of AS (kcolor = 0.01min,1, kcarotene = 0.0165min,1). [source] Glucoraphanin extraction from Cardaria draba: Part 1.JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2005Optimization of batch extraction Abstract Glucosinolates have historically been considered an anti-nutritional component of food and feed cereal crops. Large-scale protocols have been aimed at complete glucosinolate elimination from plants, rather than maximizing the recovery of any particular glucosinolate compound. Recently, glucoraphanin, an alkenyl glucosinolate, has been found to have nutritional value in terms of anti-carcinogenic behavior and hypertension relief. In this work, we report on the efficient capture of glucoraphanin from the noxious weed Cardaria draba. The effect of temperature, ethanol content in the aqueous solvent, initial solvent pH, solids loading, and contact time on both glucoraphanin and glucosinalbin recovery were examined. The optimal extraction conditions, evaluated using 0.11 dm3 stirred baffled vessels, were found to be 20% aqueous ethanol solvent at 70 °C and an initial pH value of 3, extracted at a solid to liquid ratio of 50 g dm,3 over 20 mins. The recovery achieved with the baffled vessels was up to three times greater than the glucoraphanin yield obtained using standard analytical procedures that involved the use of 8.0 × 10,3 dm3 of hot, 80% ethanol solutions in test tubes at the same solvent loading. This corresponds to 30 mg g,1 of glucoraphanin recovered from the dried C draba leaves, versus only 10 mg g,1 using the analytical method. Copyright © 2005 Society of Chemical Industry [source] Removal of fluoride using some lanthanum(III)-loaded adsorbents with different functional groups and polymer matricesJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2003Luo Fang Abstract Although fluoride is beneficial for human beings in small quantities, it causes dental fluorosis when consumed in larger quantities over a period of time. In recent years, considerable work has been conducted for the purpose of developing new and low cost absorbents for adsorptive removal of fluoride, especially chelating resins loaded with metal ions. In the present study, several types of adsorbents with different functional groups loaded with lanthanum(III) were prepared to be used for fluoride removal from water. The optimum conditions for loading lanthanum(III) on the adsorbents and the effects of pH and initial fluoride concentration as well as shaking time and solid,liquid ratio on the removal of fluoride have been investigated. Based on these fundamental data, the removal of fluoride from actual hot spring water was also tested as a practical application by comparing the efficiency of different adsorbents for the removal of fluoride from hot spring water. The following conclusions were obtained. (1) The different chemical composition and chemical structure of the polymer matrix play the most important role in fluoride adsorption, (2) strongly acidic adsorbents are more effective on fluoride removal at neutral pH than weakly acidic adsorbents, (3) the order of fluoride removal in the neutral pH range of 4.5,8.0 by the different La(III)-loaded adsorbents employed in the present work is as follows: 200CT resin > POJRgel > IR124resin > SOJR gel , CPAgel , WK11 resin. The column experiments showed that the 200CT resin loaded with lanthanum(III) at pH 6.0 can be successfully employed for the removal of fluoride ions from actual hot spring water. Copyright © 2003 Society of Chemical Industry [source] Factors affecting the ability of dental cements to alter the pH of lactic acid solutionsJOURNAL OF ORAL REHABILITATION, Issue 12 2000M. Patel Two related studies have been carried out to determine the effect of (a) powder:liquid ratio and (b) relative amounts of cement on the extent of buffering of a lactic acid storage solution using zinc polycarboxylate and glass,ionomer cements (both water-activated). The effect of varying the powder:liquid ratio was found to be slight and not statistically significant. On the other hand, increasing the numbers of specimens in a given volume of storage solution was found to have a significant influence on the final pH (at the 0·0005 level of significance). The fact that powder:liquid ratio did not affect the final pH led to the conclusion that attack occurs mainly at the matrix of these cements, confirming previous findings about the acid erosion process. The finding that increasing the relative amount of cement to acid storage solution strongly influenced pH suggested that, under clinical conditions, buffering would be important. When five specimens were used, the final pH corresponded to that of arrested caries, from which it was concluded that these cements have the ability to be cariostatic in vivo. [source] Determination of main taxoids in Taxus species by microwave-assisted extraction combined with LC-MS/MS analysisJOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2009Hao Luo Abstract A method based on microwave-assisted extraction (MAE) has been developed for the determination of paclitaxel and five related taxoids, namely 10-deacetylbaccatin III (10-DAB III), cephalomannine, 10-deacetylpaclitaxel (10-DAT), 7-xyl-10- deacetylpaclitaxel (7-xyl-10-DAT), and 7-epi-10-deacetylpaclitaxel (7-epi-10-DAT) in Taxus species in this study. The influential parameters of the MAE procedure were optimized, and the optimal conditions were as follows: extraction solvent 80% ethanol solution, solid/liquid ratio 1:10 (g/mL), temperature 50°C, and three extraction cycles, each cycle 10 min. The method validation for LC-MS/MS analysis was performed. The LOD and LOQ were 3.16,9.20 and 12.20,30.45 ng/mL, respectively. Repeatability and reproducibility for the six taxiods with RSD ranged from 2.78 to 3.85% and from 5.26 to 6.60%. The recoveries of the method for the six taxoids were 92.6,105.6%. The developed MAE-LC-MS/MS method was also successfully applied to determine the contents of six taxoids in different Taxus species. [source] Modelling of the hydrolysis of sorghum straw at atmospheric pressureJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2002Simón J Téllez-Luis Abstract Sorghum straw is a renewable, cheap and widespread resource. The acid hydrolysis of sorghum straw to obtain xylose solutions could be a good alternative for this abundant resource. The H2SO4 hydrolysis of sorghum straw at two different temperatures (80 and 100,°C) and three H2SO4 concentrations (2, 4 and 6%) using a solid/liquid ratio of 1:10 (w/w) was studied. Kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose, acetic acid and furfural were determined. The activation energy of the release reaction was 183.3,kJ,mol,1 for xylose and 185.8,kJ mol,1 for glucose. The optimal conditions found were 6% H2SO4 at 100,°C for 60,min, which allow one to obtain a solution with 18.27,g xylose l,1, 6.78,g glucose l,1, 0.7,g furfural l,1 and 1.35,g acetic acid l,1. It is concluded that this process has potential for utilisation of this renewable lignocellulosic resource. © 2002 Society of Chemical Industry [source] | |||||||||||||