Procedia Chemistry最新文献

{"title":"Mechanical Properties and Stability Towards Heat and UV Irradiation of Natural Rubber/Nanotitanium Dioxide Composites","authors":"","doi":"10.1016/j.proche.2016.03.001","DOIUrl":"https://doi.org/10.1016/j.proche.2016.03.001","url":null,"abstract":"","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.03.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138211615","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":"Predicting the Tensile Modulus of Randomly Oriented Nonwoven Kenaf/Epoxy Composites","authors":"N.G. Andre ,&nbsp;Z.A. Mohd. Ishak","doi":"10.1016/j.proche.2016.03.033","DOIUrl":"10.1016/j.proche.2016.03.033","url":null,"abstract":"<div><p>As there has been an increasing trend in using nonwovensnatural fiber in composites, there is a need to find good micromechanical models to represent their behavior. In this study,randomly oriented nonwoven kenaf/epoxy composites at various fiber loading has been fabricated by using resin transfer moulding (RTM) method. Experimental results show that increasing the fiber loading has led to the increment of tensile modulus. The validity of rule of mixtures (ROM) and modified rule of mixtures (MROM) which includes model by Krenchel and Nairn has also been analyzed. ROM has failed to predict the tensile modulus of the composites. Meanwhile, MROM managed to produce an accurate tensile modulus prediction due the inclusion of fiber length factor by Nairn model and fiber orientation factor by Krenchel model.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.03.033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90768970","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":"Bioactivity of a Bio-composite Fabricated from CoCrMo/Bioactive Glass by Powder Metallurgy Method for Biomedical Application","authors":"Rohaya Abdullah ,&nbsp;Nur Maizatul Shima Adzali ,&nbsp;Zuraidawani Che Daud","doi":"10.1016/j.proche.2016.03.054","DOIUrl":"10.1016/j.proche.2016.03.054","url":null,"abstract":"<div><p>In present times, researchers are attracted towards studies on biocomposite as a potential biodegradable bone implant materials. Bioactivity of the composite in a simulated body fluid (SBF) was investigated. A porous Co-Cr-Mo based composite material with bio-glass 45S5 was produce by using powder metallurgy method (PM) technology. Prepared composite powders were cold pressed and sintered at 1000<!--> <!-->°C for 2<!--> <!-->h. X-ray diffraction (XRD), scanning electron microscopy were used for phase analysis and also for evaluation of particle distribution of composites. Bioactivity behaviour of the prepared nanocomposites was evaluated in simulated body fluid (SBF) for 1 up to 18 days. The results showed that the apatite layer were formed on the surface of sample with addition of bioactive glass. It was concluded that bioinert Co-Cr-Mo alloy could be successfully converted into bioactive composite by adding 6 wt% of BG particles.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.03.054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72902368","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":"Synthesis of Biodegradable Mg-Zn Alloy by Mechanical Alloying: Effect of Milling Time","authors":"Emee Marina Salleh,&nbsp;Sivakumar Ramakrishnan,&nbsp;Zuhailawati Hussain","doi":"10.1016/j.proche.2016.03.048","DOIUrl":"10.1016/j.proche.2016.03.048","url":null,"abstract":"<div><p>Magnesium (Mg) is one such promising light weight metal, which is currently utilized for bio-engineering applications. Mg possesses a number of attractive characteristics that make Mg-based materials potential candidates to serve as implants for load-bearing applications in the medical industry due to its good biocompatibility and biodegradability. However, Mg and its alloys are susceptible to suffer attack in chloride containing solutions, e.g. the human body fluid or blood plasma. Thus, alloying with other metal elements is the most effective tool to improve mechanical properties and corrosion resistance of Mg. In this current work, binary Mg-Zn alloy was produced using mechanical alloying (MA) followed by compaction and sintering. The aim of this work was to study the effect of milling time on binary magnesium-zinc (Mg-Zn) alloy synthesized by mechanical alloying. A powder mixture of Mg and Zn with the composition of Mg-10wt%Zn was milled in a planetary mill under argon atmosphere using a stainless steel container and balls. Milling process was carried out at 250<!--> <!-->rpm for various milling times i.e. 1, 2, 5, 10 and 15<!--> <!-->hours. 3% n-heptane solution was added prior to milling process to avoid excessive cold welding of the powder. Then, as-milled powder was compacted under 400<!--> <!-->MPa and sintered in a tube furnace at 350<!--> <!-->°C in argon flow. The refinement analysis of the x-ray diffraction patterns shows the presence of Mg-Zn solid solution and formation of MgZn₂ when Mg-Zn powder was mechanically milled for 2<!--> <!-->hours and further. A prolonged milling time has increased the density and microhardness of the sintered Mg-Zn alloy.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.03.048","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85536539","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":"Gamma Radiolysis of the Highly Selective Ligands CyMe4BTBP and CyMe4BTPhen: Qualitative and Quantitative Investigation of Radiolysis Products","authors":"Holger Schmidt ,&nbsp;Andreas Wilden ,&nbsp;Giuseppe Modolo ,&nbsp;Dirk Bosbach ,&nbsp;Beatrix Santiago-Schübel ,&nbsp;Michelle Hupert ,&nbsp;Jaroslav Švehla ,&nbsp;Bohumir Grüner ,&nbsp;Christian Ekberg","doi":"10.1016/j.proche.2016.10.005","DOIUrl":"10.1016/j.proche.2016.10.005","url":null,"abstract":"<div><p>The highly selective nitrogen donor ligands CyMe₄BTBP and CyMe₄BTPhen where γ–irradiated under identical experimental conditions in 1–octanol with and without contact to nitric acid solution. Subsequently, solvent extraction experiments were carried out to evaluate the stability of the extractants against γ–radiation monitoring Am(III) and Eu(III) distribution ratios. Generally, decreasing distribution ratios with increasing absorbed dose were detected for both molecules. Furthermore, qualitative mass spectrometric analyses were performed and ligand concentrations were determined by HPLC-DAD after irradiation to investigate the radiolysis mechanism. An exponential decrease with increasing absorbed dose was observed for both ligands with a faster rate for CyMe₄BTPhen. Main radiolysis products indicated the addition of one or more diluent molecules (1–octanol) to the ligand via prior production of α-hydroxyoctyl radicals from diluent radiolysis. The addition of nitric acid during the irradiation lead to a remarkable stabilization of the system, as the extraction of Am(III) and Eu(III) did not change significantly over the whole examined dose range. Quantification of the remaining ligand concentration on the other hand showed decreasing concentrations with increasing absorbed dose. The stabilization of D values is therefore explained by the formation of 1–octanol addition products which are also able to extract the studied metal ions.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85750935","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":"Synthesis of LiCoO2 Prepared by Sol–gel Method","authors":"N. A. A. Aziz, T. K. Abdullah, A. A. Mohamad","doi":"10.1016/J.PROCHE.2016.03.114","DOIUrl":"https://doi.org/10.1016/J.PROCHE.2016.03.114","url":null,"abstract":"","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88622162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MicroRaman Measurements for Nuclear Fuel Reprocessing Applications","authors":"Amanda Casella ,&nbsp;Amanda Lines ,&nbsp;Gilbert Nelson ,&nbsp;Job Bello ,&nbsp;Samuel Bryan","doi":"10.1016/j.proche.2016.10.065","DOIUrl":"10.1016/j.proche.2016.10.065","url":null,"abstract":"<div><p>Treatment and reuse of used nuclear fuel is a key component in closing the nuclear fuel cycle. Solvent extraction reprocessing methods that have been developed contain various steps tailored to the separation of specific radionuclides, which are highly dependent upon solution properties. The instrumentation used to monitor these processes must be robust, require little or no maintenance, and be able to withstand harsh environments such as high radiation fields and aggressive chemical matrices.</p><p>Our group has been investigating the use of optical spectroscopy for the on-line monitoring of actinides, lanthanides, and acid strength within fuel reprocessing streams. This paper will focus on the development and application of a new MicroRaman probe for on-line real-time monitoring of the U(VI)/nitrate ion/nitric acid in solutions relevant to used nuclear fuel reprocessing. Previous research has successfully demonstrated the applicability on the macroscopic scale, using sample probes requiring larger solution volumes. In an effort to minimize waste and reduce dose to personnel, we have modified this technique to allow measurement at the microfluidic scale using a Raman microprobe. Under the current sampling environment, Raman samples typically require upwards of 10<!--> <!-->mL and larger. Using the new sampling system, we can sample volumes at 10<!--> <!-->μL or less, which is a scale reduction of over 1,000 fold in sample size.</p><p>This paper will summarize our current work in this area including: comparisons between the macroscopic and microscopic probes for detection limits, optimized channel focusing, and application in a flow cell with varying levels of HNO₃, and UO₂(NO₃)₂.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.065","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88778089","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":"Chemically Modified Electrodes for Recessed Microelectrode Array","authors":"N.A. Mohd Said ,&nbsp;V.I. Ogurtsov ,&nbsp;K. Twomey ,&nbsp;L.C. Nagle ,&nbsp;G. Herzog","doi":"10.1016/j.proche.2016.07.002","DOIUrl":"10.1016/j.proche.2016.07.002","url":null,"abstract":"<div><p>Chemical modifications on recessed microelectrode array, achieved via electrodeposition techniques are reported here. Silicon-based gold microelectrode arrays of 10<!--> <!-->μm microband and microdisc array were selected and functionalised using sol-gel and nanoporous gold (NPG) respectively. For electrochemically assisted self-assembly (EASA) formati6154on of sol-gel, electrode surface was first pre-treated with a self-assembled partial monolayer of mercaptopropyltrimethoxysilane (MPTMS) before transferring it into the sol containing cetyltrimethyl ammonium bromide (CTAB)/tetraethoxysilane (TEOS):MPTMS (90:10) precursors. A cathodic potential is then applied. It was found that larger current densities were required in ensuring successful film deposition when moving from macro- to micro- dimensions. For NPG modification, a chemical etching process called dealloying was employed. NPG of three different thicknesses have been successfully deposited. All the modified and functionalized microelectrode arrays were characterized by both optical (SEM) and electrochemical analysis (cyclic voltammetry and impedance spectroscopy). An increase in surface area and roughness has been observed and such will benefit for future sensing application.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.07.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85199040","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":"Thermal and Morphological Properties of Poly (Lactic Acid)/Nanocellulose Nanocomposites","authors":"R. Khoo, H. Ismail, W. Chow","doi":"10.1016/J.PROCHE.2016.03.086","DOIUrl":"https://doi.org/10.1016/J.PROCHE.2016.03.086","url":null,"abstract":"","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86288208","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Xenon Recovery from Molybdenum-99 Production","authors":"Robert T. Jubin ,&nbsp;Patricia D. Paviet ,&nbsp;James C. Bresee","doi":"10.1016/j.proche.2016.10.011","DOIUrl":"10.1016/j.proche.2016.10.011","url":null,"abstract":"<div><p>The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) sponsors research and development on the recycle of used commercial nuclear fuel as an option for future nuclear fuel cycles that offers increased use of uranium and thorium resources and a possible reduction in the overall cost of nuclear waste management. The two alternatives, direct disposal of used fuel and fuel recycle, are broadly referred to as open and closed fuel cycles. One requirement of a closed fuel cycle is the safe management of radioactive off-gases, which includes ¹⁴C, radioiodine and the noble gases, including radioxenon. The longest lived relevant radioxenon isotope is ¹²⁷Xe; with a half-life of just 36.35 days it is feasible to trap and hold the radioxenon to allow for decay to safe environmental levels. However, the very weak chemical bonds of noble gases, in this case xenon, make them difficult to trap, which led to an extensive DOE-NE study of noble gas adsorption on various molecular sieves as an alternative to costly cryogenics processes. Preliminary results indicate that xenon adsorption at near room temperature on molecular sieves, both synthetic and natural, may have both cost and efficiency advantages over cryogenic processes.</p><p>Xenon radioisotopes with short half-lives have value in the detection of underground nuclear explosions. However radioxenon released by medical isotope production facilities produces high backgrounds that complicate its use for nuclear explosion detection. Specifically, recovery of ⁹⁹Mo for medical applications from short-cooled irradiated ²³⁵U targets results in the release of some radioxenon. In March 2015, by a unanimous vote of the five permanent members of the United Nations Security Council, commercial producers of ⁹⁹Mo were asked to decrease and, if possible, eliminate the emissions of radioactive xenon from their production processes. The use of materials currently being evaluated for Xe and Kr capture for use in UNF processing applications may provide a cost effective mechanism to achieve the United Nations Security Council goal.</p></div>","PeriodicalId":20431,"journal":{"name":"Procedia Chemistry","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.proche.2016.10.011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82845747","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}