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991.
Absorption/desorption of calcium ions on polypyrrole-loaded reticulated vitreous carbon 总被引:1,自引:0,他引:1
Mahmoud M. Saleh C. Weidlich K.-M. Mangold K. Jüttner 《Journal of Applied Electrochemistry》2006,36(2):179-186
Polypyrrole/polystyrene sulfonate-loaded reticulated vitreous carbon electrodes RVC/PPy/PSS were studied as electrochemical
cation exchangers for the absorption of Ca2+ ions from aqueous solutions. Two grades of RVC were used mainly with 20 and 45 PPI. The preparation and characterization
of the PPy/PSS layers on RVC are described. The structure and morphology of the porous electrodes were characterized using
cyclic voltammetry (CV) and scanning electron microscopy (SEM). The potential dependent absorption and desorption of Ca2+ on RVC/PPy/PSS electrodes was studied in 0.1 M CaCl2 solution using chronoamperometry and atomic adsorption spectroscopy (AAS). The extent of Ca2+ ions absorbed into RVC/PPy/PSS was found to increase with decreasing absorption potential, the specific surface area and
the extent of polymer loading. Recovery of the RVC/PPy/PSS electrode was performed by anodic polarization at potentials at
which Ca2+ ions are desorbed. The coulomb efficiency for the Ca2+ desorption process was found to be higher than that for the Ca2+ absorption process. From these results the feasibility of using RVC/PPy/PSS for water softening was determined under the
prevailing experimental conditions. 相似文献
992.
Mohammad Amer Arafah Hazza S. Al‐Harbi Saad Haj Bakry 《International Journal of Network Management》2007,17(4):295-305
Grid computing is emerging as the foundation upon which virtual organizations can be built. Such organizations are becoming of increasing importance for tackling various projects, both in academic and in business fields. This paper is concerned with presenting an integrated view of the grid to readers interested in understanding it, or perhaps in developing it further or making use of it in the future. The target view is based on the STOPE (strategy/technology/organization/people/environment) framework that has previously been used to integrate the issues of various information technology problems over its well‐defined domains. For strategy, the view considers the reasons associated with the need for the grid, including grid services and grid benefits. For technology, the technical components of the grid and their functions are taken into account. For organization, the organizations concerned with the development, technology production, service provisioning and use of the grid are considered. For people, those associated with the grid in the related organizations are taken into account. For the environment, rules, practices and support associated with the grid are discussed. Finally, the paper emphasizes questions that need to be answered in order to contribute to the future development of the grid. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
993.
Mohammad T. Khasawneh Shannon R. Bowling Sittichai Kaewkuekool Byung Rae Cho 《Quality Engineering》2005,17(2):227-241
As an extension to the singly truncated case, this article further examines a doubly truncated normal distribution. In this article, we consider both symmetric and asymmetric cases with two truncation points on the left and the right, and develop the tables of a truncated mean, a truncated variance, and a cumulative probability. 相似文献
994.
Keiichi?TomishigeEmail author Hiroaki?Yasuda Yuichi?Yoshida Mohammad?Nurunnabi Baitao?Li Kimio?Kunimori 《Catalysis Letters》2004,94(1-2):45-47
High surface area zirconium phosphate in an amorphous phase exhibits high activities for water-related reactions such as hydrolysis of ethyl acetate and esterification of acetic acid with ethanol. The zirconium phosphate is insoluble during the reaction, is recoverable by simple filtration, and can be reused at least five times without any treatment. 相似文献
995.
Mohammad Asif 《Powder Technology》2004,145(2):113-122
Contrary to the widely held notion that the total bed height of a binary solid fluidized bed will be the sum of heights of the two individual mono-component beds fluidized at the same velocity, significant negative deviations have been observed in our experimental investigation. The negative deviations, signifying a contraction of the total volume of the binary solid fluidized bed, could sometimes be as high as 25% of the actual volume. The volume contraction has been found to depend mainly upon the degree of solids mixing prevailing in the bed irrespective of whether it is fully fluidized or not. The composition of the binary solid fluidized was another important factor that influenced the contraction behaviour of the bed besides the size ratio of the two constituent solid species of the binary present in the bed. 相似文献
996.
Michael Wootton Mohammad Shams-Ud-Din 《Journal of the science of food and agriculture》1986,37(4):387-390
Wheat bran was sieved into coarse, medium and fine fractions prior to extraction with tap water. Bran, bran extract and bran residue were analysed for moisture, protein, fat, ash, pentosan and phytic acid. Farinograph measurements and baking tests showed maximum dough resistance and loaf volume of a white flour were both increased by the addition of the residue. Both these parameters were substantially decreased by bran extract and, to a lesser degree, by the bran itself. These findings were common amongst the size fractions although the residue from the coarse bran had the greatest effect on loaf volume and dough properties. 相似文献
997.
Mohammad I. El-Khaiary 《化学工程与技术》1997,20(5):338-341
A study was conducted on the stoichiometry of the reaction that takes place on the extraction of ferric ions by didodecyl naphthalene sulphonic acid (HDDNSA) from phosphoric acid solutions. The experimental results were numerically analyzed by nonlinear regression. It was found that ferric forms two compounds with HDDNSA, namely Fe(DDNSA)3, and FeHPO4-DDNSA. The values of the equilibrium constants of the reactions involved were also calculated. 相似文献
998.
Widespread use of non-volatile memories, especially flash memories, in diverse applications such as in mobile computing and system-on-chip is becoming a common place. As a result, testing them for faults and reliability is drawing considerable interest of designers and researchers. One of the most predominant failure modes for which these memories must be tested is called disturb faults. In this paper, we first analyze different defects that are responsible for disturb faults using a 2-dimension device simulator. We determine the impact of various defects on cell performance and develop a methodology based on channel erase technique to detect these defects. Our tests are efficient and can be converted to march tests prevalently used to test memories. We also propose a very low cost design-for-testability approach that can be used to apply the test technique developed in this paper. 相似文献
999.
Seyed Mohamad Mahdi DoustMohamadi Morteza Vahedpour Mohammad Hossein Rasoulifard Azam Heidari 《Water and Environment Journal》2023,37(1):154-165
In the present study, the photooxidative degradation of Acid Red 14 (AR 14) was investigated in the UV/persulfate process, and the results of the degradation rate of AR 14 were parametrically represented by ordinary differential equations to find mathematical model for the degradation rate of AR 14 in this process. Our experimental observations led to a model for AR 14 degradation in the UV/persulfate system that could be used to predict removal efficiency by changes of S2O82− (X1) and dye concentration (X2), pH (X3), temperature (X4) and also distance of UV lamp from solution (X5). It was found that persulfate and dye concentrations were the most important parameters for AR 14 degradation rate. Moreover, the results showed that the degradation rate was in good agreement with the first-order kinetics for all the parameter values studied. Moreover, the results of the mathematical model agree well with the experimental values (R2 = 0.96). Our findings in this study showed that degradation efficiency of UV/S2O82− process for AR 14 was obtained as 98%. Therefore, this model could be applicable before scaling up the AR 14 degradation using UV/persulfate process. 相似文献
1000.
Mohammad Ali Takassi Ghasem Zargar Mohammad Madani Amin Zadehnazari 《Petroleum Science and Technology》2017,35(4):385-391
Most of the synthetic surfactants investigated with the aim of enhanced chemically oil recovery in the literature have environmental drawbacks. In this work, application of an environmentally-friendly synthetic surfactant as an enhanced oil recovery agent is introduced by measuring interfacial tension of water–kerosene systems and wettability alteration of carbonate pellets. For this purpose, an amino acid-based surfactant was initially synthesized using a new synthetic approach which was subsequently confirmed by spectra of Fourier transform infrared and Proton nuclear magnetic resonance. Results showed a value of critical micelle concentration in the range of 9000–9100 ppm for this surfactant. Results also demonstrated a decrease of 38.53% in water–kerosene system interfacial tension and a 17.76% reduction in oil-wetness of the carbonate pellets. 相似文献