Procedia Chemistry最新文献

{"title":"Photoelectron Spectroscopy (XPS) and Cyclic Voltammetry (CV) Investigation of UxTh1-xO2 Thin Films","authors":"Pelin Cakir ,&nbsp;Rachel Eloirdi ,&nbsp;Frank Huber ,&nbsp;Rudy J.M. Konings ,&nbsp;Thomas Gouder","doi":"10.1016/j.proche.2016.10.044","DOIUrl":"10.1016/j.proche.2016.10.044","url":null,"abstract":"<div><p>Thin film samples of UO₂ and U_0.55Th_0.45O₂ have been prepared by sputter co-deposition under argon atmosphere in presence of oxygen (reactive sputtering) onto gold foil. Films were characterized by X-Ray Photoelectron Spectroscopy (XPS). Cyclic Voltammetry (CV) studies have been made by using the thin films as electrodes in 0.01<!--> <!-->M NaCl pH neutral non-purged electrolyte. The effect of thorium in the UO₂ lattice is observed by comparing the U_0.55Th_0.45O₂ electrode to the UO₂ electrode. The results indicate that uranium develops enhanced resistance to the oxidation when thorium is added to the lattice. After the CV measurements, the films were again characterized by XPS. The surface is enriched in thorium by 11%. Uranium is in a higher oxidation state; however, uranium is less oxidized in U_0.55Th_0.45O₂ than in UO₂.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"21 ","pages":"Pages 314-318"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.044","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89972022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Curcuminoid Prevents Protein Oxidation but not Lipid Peroxidation in Exercise Induced Muscle Damage Mouse","authors":"Bambang Purwanto ,&nbsp;Harjanto ,&nbsp;I. Ketut Sudiana","doi":"10.1016/j.proche.2016.01.029","DOIUrl":"10.1016/j.proche.2016.01.029","url":null,"abstract":"<div><p>Oxidative stress is believed as underlined mechanism of exercise induced muscle damage. This study was aimed to investigate curcuminoid effect on protein oxidation and lipid peroxidation muscle of exercised induced model. Adult male healthy mice were used as experiment models, grouped in to curcuminoid treated, placebo (corn oil only treated) and untreated group. Protein carbonyl level was significantly lower in curcuminoid treated group compared with untreated group (p =0.003). In the contrary, the malondialdehyde level was not significantly different between those groups (p = 0.092).</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"18 ","pages":"Pages 190-193"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.01.029","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74328513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an AD5933-based Impedance Meter Prototype for Impedimetric Sensor Applications","authors":"Mohd Akmal Mhd Yusoff","doi":"10.1016/j.proche.2016.07.009","DOIUrl":"10.1016/j.proche.2016.07.009","url":null,"abstract":"<div><p>This paper summarizes the progress done on the development of an impedance meter prototype. The prototype is to be a substitute for commercial equipment in reading impedimetric sensor for future portable applications. The prototype allows the impedimetric sensor to be excited with a frequency from 0.1-20kHz. Autolab's “Dummy Cell 2” has been used as the Device under Test (DUT). The DUT's phase response to AD5933 Evaluation Board and Hioki IM3590 Chemical Impedance analyzer in the range of 0.1-20kHz has been recorded and analyzed. It was found that the R-squared values of the regression lines were above 0.9 which indicates that AD5933 measurement is comparable to commercial equipment and suitable for impedimetric sensor application.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"20 ","pages":"Pages 56-59"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.07.009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88074664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Role and Efficiency of Ammonium Sulphate Precipitation in Purification Process of Papain Crude Extract","authors":"Maria Goretti M. Purwanto","doi":"10.1016/j.proche.2016.01.020","DOIUrl":"10.1016/j.proche.2016.01.020","url":null,"abstract":"<div><p>It has been common to do fractionation (for example using ammonium sulphate as a precipitating agent) before doing a more sophisticated method for purification of a protein. The logic behind this is easy to understand, but in fact, the precipitation step often causes severe loss in yield and activity of the protein, making the whole purification effort too costly. In this work we evaluated the specific activity (thus, purification factor) and total activity (yield) during the purification process of papain from a crude extract using ion exchange chromatography (IEC), with and without prior fractionation using ammonium sulphate. Detail assays in each step were recorded and SDS-PAGE was also done to reveal the protein profile of the purification products.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"18 ","pages":"Pages 127-131"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.01.020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81937613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physical Properties of Highly Active Liquor Containing Molybdate Solids","authors":"Barbara Dunnett ,&nbsp;Tracy Ward ,&nbsp;Rachel Roberts ,&nbsp;Jonathan Cheesewright","doi":"10.1016/j.proche.2016.10.004","DOIUrl":"10.1016/j.proche.2016.10.004","url":null,"abstract":"<div><p>The reprocessing of irradiated nuclear fuel at Sellafield produces a nitric acid based Highly Active Liquor (HAL) waste. The liquor, containing fission products and process additives, is concentrated in an evaporator in order to reduce the volume and is then stored in Highly Active Storage Tanks (HASTs) prior to vitrification. Caesium phosphomolybdate (CPM) is precipitated during the evaporation process and can convert to zirconium molybdate (ZM) during storage.</p><p>During Post Operational Clean Out (POCO) of the HASTs, it is expected that their highly active content will be reduced by repeated cycles of washing using nitric acid and other reagents. Initial washings are likely to have a chemical composition comparable to concentrated HAL, becoming more dilute during the wash-out process. It is expected that the wash-out process will also recover significant quantities of molybdate solids (ZM, CPM or a mixture) from the HASTs.</p><p>In order to determine the processing challenges from such washings during POCO, the physical properties of varying concentrations of non-active HAL simulants containing molybdate solids have recently been measured by the UK's National Nuclear Laboratory. The following measurements are presented and discussed:</p><ul><li><span>•</span><span><p>Particle size distribution</p></span></li><li><span>•</span><span><p>Density</p></span></li><li><span>•</span><span><p>Settling behaviour of solids</p></span></li><li><span>•</span><span><p>Voidage of settled sediment beds</p></span></li><li><span>•</span><span><p>Viscosity</p></span></li><li><span>•</span><span><p>Yield stress</p></span></li><li><span>•</span><span><p>Influence of ZM morphology on physical properties</p></span></li></ul></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"21 ","pages":"Pages 24-31"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82022270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure and Catalytic Mechanism of 3-Ketosteroid Dehydrogenases","authors":"Bauke W. Dijkstra ,&nbsp;Niels van Oosterwijk ,&nbsp;Ali Rohman","doi":"10.1016/j.proche.2016.01.006","DOIUrl":"10.1016/j.proche.2016.01.006","url":null,"abstract":"<div><p>3-Ketosteroid dehydrogenases (KSTDs) are FAD-dependent enzymes that introduce a double bond in the A ring of 3-ketosteroid substrates to initiate degradation of the steroid nucleus. Δ¹-KSTD desaturates the C1-C2 bond of the steroid, while Δ⁴-KSTD targets the C4-C5 bond. Crystal structures with bound products showed that Δ¹- and Δ⁴-KSTD use different amino acid residues to catalyze an otherwise mechanistically very similar reaction (Δ¹-KSTD: Tyr318, Tyr119, and Tyr487; Δ⁴-KSTD: Ser468, Tyr319, and Tyr466). However, the substrates are rotated by ∼40° about an axis perpendicular to their plane to bring the target bond (C1-C2 or C4-C5) in the right position.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"18 ","pages":"Pages 3-11"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.01.006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82165580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Used Mixed Oxide Fuel Reprocessing at RT-1 Plant","authors":"Dmitrii Kolupaev ,&nbsp;Michail Logunov ,&nbsp;Alexader Mashkin ,&nbsp;Konstantin Bugrov ,&nbsp;Konstanin Korchenkin ,&nbsp;Andrei Shadrin ,&nbsp;Konstanin Dvoeglazov","doi":"10.1016/j.proche.2016.10.028","DOIUrl":"10.1016/j.proche.2016.10.028","url":null,"abstract":"<div><p>Reprocessing of the mixed uranium-plutonium spent nuclear fuel of the BN-600 reactor was performed at the RT-1 plant twice, in 2012 and 2014. In total, 8 fuel assemblies with a burn-up from 73 to 89 GW day/t and the cooling time from 17 to 21 years were reprocessed. The reprocessing included the stages of dissolution, clarification, extraction separation of U and Pu with purification from the fission products, refining of uranium and plutonium at the relevant refining cycles. Dissolution of the fuel composition of MOX UNF in nitric acid solutions in the presence of fluoride ion has occurred with the full transfer of actinides into solution. Due to the high content of Pu extraction separation of U and Pu was carried out on a nuclear-safe equipment designed for the reprocessing of highly enriched U spent nuclear fuel and Pu refining. Technological processes of extraction, separation and refining of actinides proceeded without deviations from the normal mode. The output flow of the extraction outlets in their compositions corresponded to the regulatory norms and remained at the level of the compositions of the streams resulting from the reprocessing of fuel types typical for the RT-1 plant. No increased losses of Pu into waste have been registered during the reprocessing of BN-600 MOX UNF an compare with VVER-440 uranium UNF reprocessing.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"21 ","pages":"Pages 198-202"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85267869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling of Nitric and Nitrous Acid Chemistry for Solvent Extraction Purposes","authors":"H. McKenzie ,&nbsp;J. MacDonald-Taylor ,&nbsp;F. McLachlan ,&nbsp;R. Orr ,&nbsp;D. Woodhead","doi":"10.1016/j.proche.2016.10.067","DOIUrl":"10.1016/j.proche.2016.10.067","url":null,"abstract":"<div><p>Nitric acid plays an integral role in the reprocessing of irradiated fuel. It is well known that nitric acid degrades; its often yellow hue signifies the presence of decomposition products. The decomposition of nitric acid is accelerated by temperature and radiolysis; therefore it is an important consideration in the reprocessing of nuclear fuels.</p><p>Thermal and radiolytic reactions of nitric acid result in the formation of redox active nitrogen species, of which nitrous acid is of particular concern, largely due to its redox reactions with plutonium and neptunium. Such reactions are important to understand as plutonium and neptunium can exist in a number of oxidation states; the oxidation state has a direct effect on the species extractability. The effect of nitrous acid is exacerbated as it catalyzes its own production and its reactions with actinides are typically autocatalytic; thus even micromolar quantities can have a large effect. A full understanding of solvent extraction requires us to understand actinide valence states which in turn require us to understand what nitrogen species are present and their concentrations.</p><p>As a first step in the overall objective of enhancing process models, the kinetic data for nitric acid decomposition reactions has been investigated in order to produce an initial dynamic model of decomposition under aqueous conditions. The identification of a set of kinetic reactions suitable for modelling has been the primary focus of this work. A model of nitric acid thermal decomposition will help develop a better understanding of nitric acid decomposition chemistry and enable better prediction of the oxidation states of species in solution. It is intended to later extend the model to include radiolytic reactions and then further to incorporate an organic phase in order to have a model which covers all decomposition routes for nitric acid within a nuclear fuel reprocessing scheme. The model will be used as a sub model for process models relating to nuclear fuel reprocessing to allow the nitric acid decomposition to be included and the effect of this on operations to be predicted. This is particularly relevant for models of maloperations where different fault scenarios can be investigated and the results of these predicted, as for example unusually high acidity could increase the yields of redox active species significantly altering actinide oxidation states.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"21 ","pages":"Pages 481-486"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.067","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81242651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Activity Coefficients of Uranyl Nitrate and Nitric Acid in Aqueous Mixtures","authors":"Alexander Ochkin,&nbsp;Dmitry Gladilov,&nbsp;Sergey Nekhaevskiy,&nbsp;Alexey Merkushkin","doi":"10.1016/j.proche.2016.10.013","DOIUrl":"10.1016/j.proche.2016.10.013","url":null,"abstract":"<div><p>The activity coefficients of nitric acid and uranyl nitrate in in aqueous mixtures are necessary to model the system H₂O-HNO₃-UO₂(NO₃)₂-TBP-diluent. Three methods have been compared in this work to determine activity coefficients based on experimental data, Pitzer's equation or Zdanovskiy's rule. Acid activities have been calculated from the data of two first methods. These results were compared with the data of third method. Errors were about 3.3.%. Activity coefficients of uranyl nitrate γ_U as a function of concentration of uranyl nitrate and nitric acid were determined in 76 mixed solutions. The equation to calculate γ_U was proposed.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"21 ","pages":"Pages 87-92"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73036959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural and Electrical Characterizations of CuNi Thin Film Resistors","authors":"Nurul Khalidah Yusop ,&nbsp;Nurulakmal Mohd Shariff ,&nbsp;See Chin Chow ,&nbsp;Ahmad Badri Ismail","doi":"10.1016/j.proche.2016.03.061","DOIUrl":"10.1016/j.proche.2016.03.061","url":null,"abstract":"<div><p>This work studied the development of Cu-Ni for thin film resistor; specifically reported in this paper is the surface morphology and resistance. Films were deposited on the substrate of commercialized flame retardant (generally known as FR4) printed circuit board by using thermal evaporator. The thickness of the film was set to 100<!--> <!-->nm and the dc current was maintained at 26 A. The sheet resistance and bulk resistivity of the thin films were measured via four-point probe test. The stability of thin film resistor was measured through temperature coefficient of resistance (TCR). According to the experimental results, it can be seen that the sheet resistance of the thin film resistor decreased with increasing copper composition.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":"19 ","pages":"Pages 619-625"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.03.061","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81523420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}