The Experts below are selected from a list of 231525 Experts worldwide ranked by ideXlab platform
C Namasivayam - One of the best experts on this subject based on the ideXlab platform.
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kinetic studies of adsorption of thiocyanate onto zncl2 activated carbon from coir pith an agricultural solid waste
Chemosphere, 2005Co-Authors: C Namasivayam, D SangeethaAbstract:Abstract The adsorption of thiocyanate onto ZnCl2 activated carbon developed from coir pith was investigated to assess the possible use of this adsorbent. The influence of various parameters such as agitation time, thiocyanate concentration, adsorbent dose, pH and temperature has been studied. Adsorption followed second-order Rate Kinetics. Two theoretical adsorption isotherms, namely, Langmuir and Freundlich were used to describe the experimental results. The Langmuir adsorption capacity (Q0) was found to be 16.2 mg g−1 of the adsorbent. The per cent adsorption was maximum in the pH range 3.0–7.0. pH effect and desorption studies showed that ion exchange and chemisorption mechanism are involved in the adsorption process. Thermodynamic parameters such as ΔG0, ΔH0 and ΔS0 for the adsorption were evaluated. The negative values of ΔH0 confirm the exothermic nature of adsorption. Effects of foreign ions on the adsorption of thiocyanate have been investigated. Removal of thiocyanate from ground water was also tested.
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removal of direct red 12b and methylene blue from water by adsorption onto fe iii cr iii hydroxide an industrial solid waste
Journal of Environmental Management, 2005Co-Authors: C Namasivayam, S SumithraAbstract:Abstract Removal of direct red 12B and methylene blue by adsorption onto Fe (III)/Cr (III) hydroxide was studied using various parameters such as agitation time, dye concentration, adsorbent dose and pH. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. Adsorption followed second-order Rate Kinetics. The Langmuir adsorption capacity ( Q o ) was found to be 5.0 and 22.8 mg dye per g of the adsorbent for direct red 12B and methylene blue, respectively. Acidic pH was favorable for the adsorption of direct red 12B and basic pH for methylene blue. Desorption studies showed that chemisorption seems to be the major mode of adsorption.
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removal of congo red from water by adsorption onto activated carbon prepared from coir pith an agricultural solid waste
Dyes and Pigments, 2002Co-Authors: C Namasivayam, D KavithaAbstract:The adsorption of Congo Red by coir pith carbon was carried out by varying the parameters such as agitation time, dye concentration, adsorbent dose, pH and temperature. Equilibrium adsorption data followed both Langmuir and Freundlich isotherms. Adsorption followed second-order Rate Kinetics. The adsorption capacity was found to be 6.7 mg dye per g of the adsorbent. Acidic pH was favourable for the adsorption of Congo Red. Desorption studies suggest that chemisorption might be the major mode of adsorption.
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uptake of dyes by a promising locally available agricultural solid waste coir pith
Waste Management, 2001Co-Authors: C Namasivayam, R Radhika, S SubaAbstract:The adsorption of rhodamine-B and acid violet by coir pith carbon was carried out by varying the parameters such as agitation time, dye concentration, adsorbent dose and pH. The adsorption followed both Langmuir and Freundlich isotherms. The adsorption capacity was found to be 2.56 mg and 8.06 mg dye per g of the adsorbent for rhodamine-B and acid violet, respectively. Adsorption of dyes followed first order Rate Kinetics. Acidic pH was favorable for the adsorption of acid violet and alkaline pH was favorable to rhodamine-B. Desorption studies showed that alkaline pH was favorable for the desorption of acid violet and acidic pH was favorable for the desorption of rhodamine-B.
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removal of dyes from aqueous solutions by cellulosic waste orange peel
Bioresource Technology, 1996Co-Authors: C Namasivayam, N Muniasamy, K Gayatri, M Rani, K RanganathanAbstract:The adsorption of dyes such as congo red, procion orange and rhodamine-B by waste orange peel was examined at different concentrations of dyes, adsorbent dosage, agitation time and pH. The adsorption obeyed both the Langmuir and Freundlich isotherms and the process of uptake followed first-order Rate Kinetics. Acidic pH was favourable for adsorption for all three dyes. Desorption studies showed that alkaline pH was efficient for desorption of all the dyes.
Giulio Magni - One of the best experts on this subject based on the ideXlab platform.
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initial Rate Kinetics of human nmn adenylyltransferases substRate and metal ion specificity inhibition by products and multisubstRate analogues and isozyme contributions to nad biosynthesis
Biochemistry, 2007Co-Authors: Leonardo Sorci, Flavio Cimadamore, Stefania Scotti, Riccardo Petrelli, Loredana Cappellacci, Palmarisa Franchetti, Giuseppe Orsomando, Giulio MagniAbstract:Initial-Rate and product inhibition studies revealed distinctive ordered ternary complex kinetic mechanisms, substRate specificities, and metal ion preferences for the three isozymes of human nicotinamide mononucleotide adenylyl-transferase (NMNAT, EC 2.7.7.1). ATP binds before NMN with nuclear isozyme NMNAT1 and Golgi apparatus NMNAT2, but the opposite order is observed with the mitochondrial isozyme NMNAT3. Only the latter utilizes ITP efficiently in place of ATP, and while NMNH conversion to NADH by NMNAT1 and NMNAT3 occurs at similar Rates, conversion by NMNAT2 is much slower. These isozymes can also be discriminated by their action on tiazofurin monophosphate (TrMP), a metabolite of the antineoplastic prodrug tiazofurin. Our finding that TrMP is only a substRate with NMNAT1 and NMNAT3 reveals for the first time an organelle selectivity in the metabolism of this important drug. In search of additional ways to discriminate these isozymes, we synthesized and tested the P1-(nicotinamide/nicotinate-ribosi...
Maria S. Zakynthinaki - One of the best experts on this subject based on the ideXlab platform.
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Modelling heart Rate Kinetics.
PLOS ONE, 2015Co-Authors: Maria S. ZakynthinakiAbstract:The objective of the present study was to formulate a simple and at the same time effective mathematical model of heart Rate Kinetics in response to movement (exercise). Based on an existing model, a system of two coupled differential equations which give the Rate of change of heart Rate and the Rate of change of exercise intensity is used. The modifications introduced to the existing model are justified and discussed in detail, while models of blood lactate accumulation in respect to time and exercise intensity are also presented. The main modification is that the proposed model has now only one parameter which reflects the overall cardiovascular condition of the individual. The time elapsed after the beginning of the exercise, the intensity of the exercise, as well as blood lactate are also taken into account. Application of the model provides information regarding the individual’s cardiovascular condition and is able to detect possible changes in it, across the data recording periods. To demonstRate examples of successful numerical fit of the model, constant intensity experimental heart Rate data sets of two individuals have been selected and numerical optimization was implemented. In addition, numerical simulations provided predictions for various exercise intensities and various cardiovascular condition levels. The proposed model can serve as a powerful tool for a complete means of heart Rate analysis, not only in exercise physiology (for efficiently designing training sessions for healthy subjects) but also in the areas of cardiovascular health and rehabilitation (including application in population groups for which direct heart Rate recordings at intense exercises are not possible or not allowed, such as elderly or pregnant women).
Leonardo Sorci - One of the best experts on this subject based on the ideXlab platform.
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initial Rate Kinetics of human nmn adenylyltransferases substRate and metal ion specificity inhibition by products and multisubstRate analogues and isozyme contributions to nad biosynthesis
Biochemistry, 2007Co-Authors: Leonardo Sorci, Flavio Cimadamore, Stefania Scotti, Riccardo Petrelli, Loredana Cappellacci, Palmarisa Franchetti, Giuseppe Orsomando, Giulio MagniAbstract:Initial-Rate and product inhibition studies revealed distinctive ordered ternary complex kinetic mechanisms, substRate specificities, and metal ion preferences for the three isozymes of human nicotinamide mononucleotide adenylyl-transferase (NMNAT, EC 2.7.7.1). ATP binds before NMN with nuclear isozyme NMNAT1 and Golgi apparatus NMNAT2, but the opposite order is observed with the mitochondrial isozyme NMNAT3. Only the latter utilizes ITP efficiently in place of ATP, and while NMNH conversion to NADH by NMNAT1 and NMNAT3 occurs at similar Rates, conversion by NMNAT2 is much slower. These isozymes can also be discriminated by their action on tiazofurin monophosphate (TrMP), a metabolite of the antineoplastic prodrug tiazofurin. Our finding that TrMP is only a substRate with NMNAT1 and NMNAT3 reveals for the first time an organelle selectivity in the metabolism of this important drug. In search of additional ways to discriminate these isozymes, we synthesized and tested the P1-(nicotinamide/nicotinate-ribosi...
Yingzhi Sun - One of the best experts on this subject based on the ideXlab platform.
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removal of cationic dyes from aqueous solution by adsorption on peanut hull
Journal of Hazardous Materials, 2005Co-Authors: Renmin Gong, Chao Yang, Yingzhi Sun, Jian ChenAbstract:The potential feasibility of peanut hul particle for removal of three cationic dyes (methylene blue, brilliant cresyl blue and neutral red) from aqueous solution was investigated. The effects of various experimental parameters were examined and optimal experimental conditions were decided. Above the value of initial pH 4, three dyes studied could be removed effectively. The isothermal data fitted the Langmuir model or Freundlich model. The adsorption processes followed the pseudo-first-order Rate Kinetics. The results in this study indicated that peanut hull was an attractive candidate for removing cationic dyes from dye wastewater.
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utilization of powdered peanut hull as biosorbent for removal of anionic dyes from aqueous solution
Dyes and Pigments, 2005Co-Authors: Renmin Gong, Yi Ding, Chao Yang, Huijun Liu, Yingzhi SunAbstract:An untried, low cost, locally available biosorbent was investigated for its anionic dye removal capacity from aqueous solution. Powder prepared from peanut hull was used for biosorption of three anionic dyes, amaranth (Am), sunset yellow (SY) and fast green FCF (FG). The effects of various experimental parameters (e.g. initial pH and dye concentration, sorbent dosage, particle size, ion strength, contact time) were examined and optimal experimental conditions were decided. At initial pH 2.0, three dyes studied could be removed effectively. The isothermal data for biosorption followed the Langmuir and Freundlich models. The biosorption processes conformed to the pseudo-first-order Rate Kinetics. The results in this study indicated that powdered peanut hull was an attractive candidate for removing anionic dyes from dye wastewater.
