Exchange Separation Research Articles

Incorporating Operability Measures Into the Process Synthesis Stage of Design

Publisher Summary This chapter discusses the issue exchanger networks or separation sequences. It is the issue of incorporating operability measures into the synthesis stage of complete chemical process plant design. Process synthesis is today largely based on steady-state analysis. Synthesis procedures that take into account dynamics, for example, in the form of controllability considerations have been developed but only for the more well-defined tasks such as the synthesis of heat exchanger networks or separation sequences. The steady-state versions of the dynamic equipment models are used to calculate the most economically profitable operating point for the process. During this optimisation, the flow-sheet structure and equipment parameters are held constant. The flexibility analysis classifies the slow disturbances as either economically significant or insignificant by considering the unregulated effect of such disturbances on the nominal economic optimum operating profit of the process.

Separation of some lanthanides on potassium zinc hexacyanoferrate ion exchanger

Adsorption behaviour of Sm3+, Gd3+, Tb3+ and Tm3+ on potassium zinc hexacyanoferrate (PZF) was investigated. The effect of K+ and Zn2+ concentrations on the distribution coefficient was studied. The mechanism of ion exchange and possible separation of the lanthanides used are discussed.

Determination of noble metals in ores containing copper, iron and nickel by graphite furnace AAS after tellurium coprecipitaiton/ion exchange separation.

Determination of noble metals in ores containing copper, iron and nickel by graphite furnace AAS after tellurium coprecipitaiton/ion exchange separation.

Separation of exchange and adsorption processes in 45Ca-Bentonite/ 54Mn 2+ System : J. Kónya and A. Hargitai Tóth, Isotope Laboratory of Kossuth Lajos University, Debrecen, Hungary, and Chemistry Department of Bessenyei György Teacher's Training College, Nyiregyháza, Hungary

Separation of exchange and adsorption processes in 45Ca-Bentonite/ 54Mn 2+ System : J. Kónya and A. Hargitai Tóth, Isotope Laboratory of Kossuth Lajos University, Debrecen, Hungary, and Chemistry Department of Bessenyei György Teacher's Training College, Nyiregyháza, Hungary

Separation of Na-Ca exchange and transient inward currents in heart cells.

Enzymatically dispersed single cells from rabbit ventricle were voltage clamped using the suction pipette method to investigate whether in isolated cardiac cells a recently described slow inward current (IEX) due to the electrogenic Na+-dependent Ca2+ extrusion also underlies a transient inward current (ITI), which can trigger certain cardiac arrhythmias. The cells were held at -40 mV to inactivate the fast sodium current. After depolarizing pulses (to 0 or +10 mV for 50 to 200 ms), slow inward "tail" currents were consistently recorded. Previous results indicate that this tail current IEX is generated by the Na+-Ca2+ exchanger. After loading the cells with Ca2+ by blocking the Na+-K+ pump [either with strophanthidin (10(-5) M) treatment or by reducing external K+ to 1 mM or less], ITIS appeared. These were usually spontaneous but occasionally were time locked to the clamp pulses. It was possible to separate IEX and ITI by a variety of methods. These include the following. 1) Different stimulation protocols; repolarizing to more negative potentials augmented IEX and decreased or eliminated ITI. Increasing the rate of stimulation diminished IEX and increased ITI. 2) Pharmacological methods; adding BaCl2 (0.5-2.0 mM) or caffeine (5-10 mM) decreased IEX but abolished ITI. The findings suggest that different mechanisms regulate these two currents.

Determination of barium in sea water by cation- exchange separation and electrothermal atomic absorption spectrometry

A method is described for the routine determination of barium in sea water by graphite-furnace atomic absorption spectrometry. Barium is separated from the main sea- water cations by collection on a cation-exchange resin. The barrium is extracted into nitric acid from a portion of the resin for injection into the pyrolytically-coated graphite furnace. The method is satifactory for the low μg l −1 levels of barium present in ocean water, with recoveries ⪖99% and a relative standard deviation of <5%.

ChemInform Abstract: Exchange ot Two‐Spin Order in NMR: Separation of Exchange and Cross‐Relaxation Processes

Chemischer InformationsdienstVolume 17, Issue 10 Physical Organic Chemistry ChemInform Abstract: Exchange ot Two-Spin Order in NMR: Separation of Exchange and Cross-Relaxation Processes G. WAGNER, G. WAGNERSearch for more papers by this authorG. BODENHAUSEN, G. BODENHAUSENSearch for more papers by this authorN. + MUELLER, N. + MUELLERSearch for more papers by this authorM. RANCE, M. RANCESearch for more papers by this authorO. W. SOERENSEN, O. W. SOERENSENSearch for more papers by this authorR. R. ERNST, R. R. ERNSTSearch for more papers by this authorK. + WUETHRICH, K. + WUETHRICHSearch for more papers by this author G. WAGNER, G. WAGNERSearch for more papers by this authorG. BODENHAUSEN, G. BODENHAUSENSearch for more papers by this authorN. + MUELLER, N. + MUELLERSearch for more papers by this authorM. RANCE, M. RANCESearch for more papers by this authorO. W. SOERENSEN, O. W. SOERENSENSearch for more papers by this authorR. R. ERNST, R. R. ERNSTSearch for more papers by this authorK. + WUETHRICH, K. + WUETHRICHSearch for more papers by this author First published: March 11, 1986 https://doi.org/10.1002/chin.198610060Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume17, Issue10March 11, 1986 RelatedInformation

Exchange of two-spin order in nuclear magnetic resonance: separation of exchange and cross-relaxation processes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTExchange of two-spin order in nuclear magnetic resonance: separation of exchange and cross-relaxation processesGerhard Wagner, Geoffrey Bodenhausen, Norbert Mueller, Mark Rance, Ole W. Soerensen, Richard R. Ernst, and Kurt WuethrichCite this: J. Am. Chem. Soc. 1985, 107, 23, 6440–6446Publication Date (Print):November 1, 1985Publication History Published online1 May 2002Published inissue 1 November 1985https://doi.org/10.1021/ja00309a002RIGHTS & PERMISSIONSArticle Views469Altmetric-Citations70LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (861 KB) Get e-Alerts Get e-Alerts

Studies of a Diffusion Flame Matrix Burner in a Combustion Chamber with Heat Exchanger

Experimental studies were carried out to make clear the combustion characteristics of a diffusion flame matrix burner in a combustion chamber with heat exchanger. The shape and the stability limits of the matrix burner flame were examined, and the concentrations of stable species and NOX in the exhaust gases were measured for methane flame, the burner surface/heat exchanger separation being the parameter. The minimum separation to maintain a stable flame with low emissions of pollutents was investigated. It has been found that this burner can be operated with good combustion and emission characteristics at a separation of only 10 mm, similarly to the matrix burner operated in the open atmosphere.

Cation Exchange Chromatographic Elution and Separation of Rubidium

Abstract The systematic cation exchange chromatographic separation of rubidium on Dowex 50W-X8 was carried out with mineral acids and their salts as eluants. A selectivity scale for various eluants in terms of the elution constant was devised. Rubidium was separated from a large number of elements in binary mixtures by the process of gradient or selective elutions or selective sorption. The noteworthy feature of the method is the sequential separation of rubidium from alkali as well as alkaline earth elements.

Liquid Anion Exchange Studies and Separation of Mercury

Abstract A new method is developed for the extractive separation of mercury from associated elements. Mercury is quantitatively extracted from 0.5 M acetic acid solution by aliquat 336 S, which acts as a liquid anion exchanger. The metal ion from the organic phase is stripped with sodium hydroxide solution and determined in the aqueous phase complexometrically. The extracted species is [2(R4N+), Hg(OAc)4 −2]. A working procedure for the selective separation of mercury from zinc, cadmium, nickel, cobalt, copper, bismuth and manganese is described.

Purification of Glyoxysomal Acetyl-CoA Acyltransferase

Acetyl-CoA acyltransferase was extracted from cotyledons of germinating cucumber seeds and purified to apparent heomogeneity. The purification based primarily on cation exchange chromatography and separation on an affinity gel. The enzyme is a dimer consisting of two subunits of molecular weight 45 000. Acetyl-CoA acyltransferase was localized in glyoxysomes, the matrix was found to be the site of thiolase function within the organelle.

Cyclic Separation Processes

Abstract This review covers cyclic separation methods used for adsorption, ion exchange, and chromatographic separation processes where the cyclic parameter is a thermodynamic variable which changes the equilibrium distribution coefficients of the solutes. The cyclic methods reviewed include heatless or pressure-swing adsorption, parametric pumping, and cycling zone adsorption. These cyclic techniques have been studied as a possible preparative chromatographic separation method or for continuous production from adsorption or ion exchange columns.

Systematic radiochemical analysis of fission products

A scheme for the sequential separation of fission products has been developed on the basis of ion-exchange techniques. It consists of a main cation-exchange process for group separation and subsidiary processes of cation or anion exchange for further separations or purifications of the individual fission products. By the present method, Zn, Rb, Sr, Y, (Zr), Mo, Pd, Cd, Te, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu and Tb can be separated simultaneously from an irradiated uranium sample. Of these, alkali, alkaline earth and rare earth metal ions are separated quantitatively. A polarographic method was applied to determine the recoveries of Zn, Mo, Pd, Cd and Te, which were not separated quantitatively.

Anion Exchange Behaviour and Separation of Thorium, Protactinium and Uranium in Nitric Acid and Acetic Acid Mixtures

Anion Exchange Behaviour and Separation of Thorium, Protactinium and Uranium in Nitric Acid and Acetic Acid Mixtures