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The relative motion of membranes

100%
Roberts M.
Open Physics
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2010
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vol. 8
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issue 6
915-919
EN
The relative classical motion of membranes is governed by the equation (w β cα c r βa)a = R δγβα r gb x δa p aγ, where w is the hessian. This is a generalization of the geodesic deviation equation and can be derived from the lagrangian p · ṙ. Quantum mechanically the picture is less clear. Some quantizations of the classical equations are attempted so that the question as to whether the Universe started with a quantum fluctuation can be addressed.
2
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STRUCTURAL AND SWELLING PROPERTIES OF HYDROGEL MEMBRANES BASED ON CHITOSAN CROSSLINKED WITH GLUTARALDEHYDE AND SODIUM TRIPOLYPHOSPHATE

80%
Gierszewska-Drużyńska M., Ostrowska-Czubenko J.
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EN
Chemically and physically crosslinked chitosan hydrogel membranes were obtained by treatment of chitosan (Ch) with glutaraldehyde (GA) and with GA and subsequently with sodium tripolyphosphate (TPP). The formation of covalent and ionic crosslinks between Ch, GA and ionic TPP was confirmed by FTIR spectroscopy. The studies of dynamic swelling behaviour of synthesized membranes in buffer solutions of different pH (1.0, 7.4, 9.0) indicated that the swelling process obeyed a second-order kinetics. Values of an apparent swelling rate constant for Ch/GA and Ch/GA/TPP membranes were of the same order for acidic and neutral swelling media but they increased for alkaline solutions.
3
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ADSORPTION OF CADMIUM IONS ON CHITOSAN MEMBRANES: KINETICS AND EQUILIBRIUM STUDIES

80%
Zielińska K., Chostenko A. G., Truszkowski S.
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vol. 15
73 - 78
EN
The presence of toxic heavy metals in industrial wastewater is a serious pollution problem. The ability of chitosan membranes as an adsorbent for cadmium ions in aqueous solution was studied. Experiments were carried out as function of contact time and concentration of cadmium ions. This study has shown that chitosan is capable of removing cadmium from aqueous solution. The removal efficiency depends on reaction time and concentration of cadmium. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Equilibrium data agreed very well with the Langmuir model. The maximum adsorption capacity of the Langmuir isotherm equation was 94 mg/g and the Langmuir adsorption equilibrium constant was 1.6 × 10-3 dm3/mg at 25 °C.
4
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EQUILIBRIUM SWELLING STUDY OF CROSSLINKED CHITOSAN MEMBRANES IN WATER, BUFFER AND SALT SOLUTIONS

80%
Gierszewska M., Ostrowska-Czubenko J.
Progress on Chemistry and Application of Chitin and its Derivatives
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2016
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vol. 21
55-62
EN
Physically crosslinked membranes were prepared by treating chitosan (Ch) with pentasodium tripolyphosphate (TPP) at different reaction conditions. The equilibrium swelling ratio, Seq, of Ch/TPP membranes in water, buffer and salt solutions at 37 C were determined. The experimental data indicated, that Seq depended on pH of buffer solution and type and concentration of salt solution. Swelling capacity in water depended on the content of TPP ions in the membrane and crosslinking density
5
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Anomalously large kinetic isotope effect

80%
Krinkin D.
Open Chemistry
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2007
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vol. 5
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issue 4
1019-1063
EN
Activated diffusion of water between macromolecules in swollen cellulose is accompanied by anomalously high kinetic isotope effects of oxygen. The separation factor of heavy-oxygen water (H218O /H216O) is thousands of permilles instead of tens of permilles according to modern Absolute Rate Theory. This anomalous separation under usual conditions is disguised by the opposing process of very fast equalization to equilibrium through water-filled cellulose pores. This process is quicker by approximately 3 orders of magnitude than diffusion through the cellulose body. As a consequence, this opposition-directed equalization virtually eliminates the results of isotope separation. To reveal this anomaly it is necessary to suppress equalization, which was the primary problem for both discovery of this anomaly and its investigation. The method of investigating the anomalous separation in cellulose was developed with suppression of this negative influence. Discussion of the theoretical nature of the anomalous kinetic isotope effect is presented. This theoretical study would probably permit the discovery and use for isotope separation of the anomalously high isotope effect for other chemical elements, in particular, for those heavier than oxygen. [...]
6
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Influence of the Selected Parameters on the Effectiveness of IGCC System Integrated With CCS Installation

70%
Skorek-Osikowska A., Bartela Ł., Kotowicz J.
Chemical and Process Engineering
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2014
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vol. 35
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issue 2
233-248
EN
The paper presents the basic input data and modelling results of IGCC system with membrane CO2 capture installation and without capture. The models were built using commercial software (Aspen and GateCycle) and with the use of authors’ own computational codes. The main parameters of the systems were calculated, such as gross and net power, auxiliary power of individual installations and efficiencies. The models were used for the economic and ecological analysis of the systems. The Break Even Point method of analysis was used. The calculations took into account the EU emissions trading scheme. Sensitivity analysis on the influence of selected quantities on break-even price of electricity was performed
7
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Influence of the Selected Parameters on the Effectiveness of IGCC System Integrated With CCS Installation

61%
Skorek-Osikowska A., Bartela Ł., Kotowicz J.
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issue 2
8
Content available remote

Fluorometric assay of oleate-activated phospholipase D isoenzyme in membranes of rat nervous tissue and human platelets

61%
Krzystanek M., Trzeciak H. I., Krzystanek E., Małecki A.
Acta Biochimica Polonica
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2010
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vol. 57
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issue 3
369-372
EN
Phospholipase D plays a key role in the biosynthesis of phosphatidic acid, a second messenger involved in essential cellular processes. Oleate-activated phospholipase D was the first mammalian phospholipase D isoform to be discovered but is the least known. The study was aimed to test a fluorometric method of assessment of oleate-activated phospholipase D activity in different biological materials. The brain cortex of male Wistar rats, cultured rat brain astrocytes, and human platelets were processed to yield plasmatic membranes for experiments. To assess phospholipase D activity the modified fluorometric method was used. Previously, the method was used only to determine H2O2. In this enzyme-coupled assay phospholipase D activity is monitored indirectly using 10-acetyl-3,7-dihydroxyphenoxazine. First, phospholipase D cleaves exogenous phosphatidylcholine to yield choline and phosphatidic acid. Second, choline is oxidized by choline oxidase to betaine and H2O2. Finally, in the presence of horseradish peroxidase, H2O2 reacts with 10-acetyl-3,7-dihydroxyphenoxazine to generate the highly fluorescent product, resorufin. The concentration of resorufin was measured using excitation and emission at 560 nm and 590 nm, respectively. The proposed optimal parameters of the tested assay are 25 µg of rat brain cortex protein, 50 µg of rat brain astrocyte protein, and 50 µg of human platelet protein in a reaction volume of 200 µL, and 2 min enzymatic reaction at 37°C. The fluorometric method may be applied to assay phospholipase D in different biological materials.
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