核科学与技术国际期刊(英文)最新文献

{"title":"X-Ray and Mössbauer Study of Magnetic Black Sand from Mayotte Island","authors":"S. Braccini, K. Krämer, S. Chapenoire","doi":"10.4236/WJNST.2016.64020","DOIUrl":"https://doi.org/10.4236/WJNST.2016.64020","url":null,"abstract":"Natural magnetic black sands are known from several sites often located in areas of volcanic origin. Their elemental and mineral composition provides information on the geology of their territory and depends on several factors occurred during their formation. A sample of black sand was collected on the seashore of the island of Mayotte in the Indian Ocean and its magnetic part was investigated by means of energy dispersive X-ray spectroscopy (EDS), powder X-ray diffraction (XRD), and MOssbauer spectroscopy at room temperature. The mineral composition is dominantly magnetite, in good agreement with samples collected in other sites of volcanic origin. Contrary to pure magnetite, a relevant fraction of Ti was detected by EDS. The 16% Ti and 1% Mn content increase the magnetite lattice parameter to 8.4312 (25) A. The broadening of XRD lines pointed towards a significant degree of disorder. This was confirmed by MOssbauer spectroscopy and is attributed to the presence of Ti replacing Fe in the magnetite lattice. The presence of Ti modifies the local magnetic field on the Fe sites, leading to a broader and more complex MOssbauer transmission spectrum with respect to the one of pure magnetite. To study the effect of temperature, samples were heated for 12 hours to 600°C and 800°C in argon and to 1000°C in air. Annealing in argon did not improve the crystallinity while annealing in air caused a complete decomposition of magnetite into hematite and pseudobrookite.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70888515","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":"Studies on Production Planning of Dispersion Type U3Si2-Al Fuel in Plate-Type Fuel Elements for Nuclear Research Reactors","authors":"M. Negro, M. Durazzo, M. A. Mesquita, E. U. Carvalho, D. A. Andrade","doi":"10.4236/WJNST.2016.64023","DOIUrl":"https://doi.org/10.4236/WJNST.2016.64023","url":null,"abstract":"Several fuel plants that supply nuclear research reactors need to increase their production capacity in order to meet the growing demand for this kind of nuclear fuel. After the enlargement of the production capacity of such plants, there will be the need of managing the new production level. That level is usually the industrial one, which poses challenges to the managerial staff. Such challenges come from the fact that several of those plants operate today on a laboratorial basis and do not carry inventory. The change to the industrial production pace asks for new actions regarding planning and control. The production process based on the hydrolysis of UF6 is not a frequent production route for nuclear fuel. Production planning and control of the industrial level of fuel production on that production route is a new field of studies. The approach of the paper consists in the creation of a mathematical linear model for minimization of costs. We also carried out a sensitivity analysis of the model. The results help in minimizing costs in different production schemes and show the need of inventory. The mathematical model is dynamic, so that it issues better results if performed monthly. The management team will therefore have a clearer view of the costs and of the new, necessary production and inventory levels.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70889318","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":"Improvement of Beam Energy Measurement System for BES-III","authors":"Jianyong Zhang, Xiao Cai, Xiaohu Mochizuki, Muchnoi Nickolai, A. Mikhail, E. Abakumova, H. Fred","doi":"10.4236/WJNST.2016.64025","DOIUrl":"https://doi.org/10.4236/WJNST.2016.64025","url":null,"abstract":"The beam energy measurement system is significant and profit for both BES-III detector and BEPC-II accelerator. The detection of the high energy scattering photons is realized by virtue of the Compton backscattering principle. Many advanced techniques and precise instruments are employed to acquire the highly accurate measurement of positron/electron beam energy. During five years’ running period, in order to satisfy the requirement of data taking and enhance the capacity of measurement itself, the upgradation of system is continued, which involves the components reformation of laser and optics subsystem, replacement of view-port of the laser to vacuum insertion subsystem, the usage of electric cooling system for high purity germanium detector, and the refinement of data acquisition and processing subsystem. The upgrading of system guarantees the smooth and effective measuring of beam energy at BEPC-II and accommodates the accurate offline energy values for further physics analysis at BES-III.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70889053","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":"Safety of Future NPPs Must Not Be in Conflict with Economics","authors":"V. Petrochenko, G. Toshinsky, O. Komlev","doi":"10.4236/WJNST.2016.64026","DOIUrl":"https://doi.org/10.4236/WJNST.2016.64026","url":null,"abstract":"The conflict between safety and economics requirements is peculiar to the present nuclear power (NP). The main point of the conflict is that for traditional type reactors the increase of requirements to safety of nuclear power plants (NPP) worsens their economical characteristics. This is caused by large potential energy accumulated in reactor coolant. In the presented paper the opportunity and expediency of changeover to reactors with heavy liquid-metal coolants (HLMC) in future NP is grounded. First of all, this refers to lead-bismuth coolant (LBC) mastered in the process of operating nuclear submarines (NS) reactors. The reactor facilities (RFs) of that type cannot cause destruction of defense barriers and make possible deterministic elimination of severe accidents with catastrophic radioactivity release. So it will make possible to eliminate the highlighted conflict and reasons for existence of population’s radiophobia. Lead-bismuth fast reactor SVBR-100 with electric power of 100 MWe is the reactor facility of that type. The effect of accumulated in coolant potential energy on safety and economics is considered. Main specific features of SVBR-100 technology providing a high level of inherent self-protection and passive safety are presented.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70889069","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":"Risk Communication and External Emergency Plan in Angra dos Reis, Brazil","authors":"R.D.S. Cunha, D. A. Andrade","doi":"10.4236/WJNST.2016.64027","DOIUrl":"https://doi.org/10.4236/WJNST.2016.64027","url":null,"abstract":"The presence of a potentially hazardous facility in a community demands several safety procedures. Bringing risk communication among those actions may help the population that lives near the facility feel more confident and have the required knowledge on how to behave in an emergency situation. A research performed in Angra dos Reis, RJ, Brazil, where a nuclear power plant is located, shows that there is a lack of information and awareness about the emergency plan.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70889190","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":"Fluorine Assessment of Igneous Rocks by Neutron Activation Analysis","authors":"A. M. Abdelbagi","doi":"10.4236/WJNST.2016.63015","DOIUrl":"https://doi.org/10.4236/WJNST.2016.63015","url":null,"abstract":"The main goal of the current study was to determine the fluorine in the \u0000rock samples coal (SARM-18, SARM-19, and SARM-20), opal glass NBS91 and \u0000phosphate rock NBS694 using neutron activation analysis. Neutrons energy of 14 \u0000MeV used for irradiation was produced by bombardment of a water-cooled titanium \u0000tri-tide target with a beam of deuterons accelerated to a potential of 350 KV to develop a neutron flux (108 n⋅cm-2⋅s-1) \u0000on the sample at the neutron generator \u0000in the ECN (Netherlands Energy Research Foundation) Petten. This new \u0000approach contributes to the existing knowledge \u0000of fluorine measurement by the coincidence channels investigation of the \u0000positron energy with respect to decay time for each radionuclide \u0000element. The present study was designed to determine the fluorine by fast \u0000neutron through the reaction of F19 (n, 2n) F18. \u0000Interference was treated by irradiating the standard of these elements and \u0000reasonable selection of the decay time between the end of irradiation and \u0000beginning of counting time. The results of this method indicate that the \u0000concentration of fluorine is agreed fairly with literatures.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70888678","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":"The Representation of the Chemical Elements’ Isotopes by the Neutron Excess Content","authors":"F. Menegus","doi":"10.4236/WJNST.2016.63016","DOIUrl":"https://doi.org/10.4236/WJNST.2016.63016","url":null,"abstract":"A more compact representation of the Segre chart of nuclides can be obtained replacing the isotopic neutron with the corresponding neutron excess number; a first sight inspection of all the natural isotopes is produced. The resulting representation shows a built-inorder in the organization of the nuclear components into the nuclei of the natural isotopes, sustained by the relevant role of the magic numbers. The interpretation, on the identical foot, of the nuclear instability of Tc, Pm and of the elements following Bi is suggested. The present representation reminds the spheron model of the nuclear structure suggested by L. Pauling. The alpha decay paths of radioactive isotopes are shown, side by side to the low energy nuclear transmutations (LENR). Representations of the artificial isotopes of the chemical elements and of the stellar nucleosynthesis processes are also proposed.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70888745","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":"Is There an Incremental Prognostic Value of Evaluating Left Ventricular Dyssynchrony by Gated SPECT in Patients with Systolic Heart Failure and Altered Myocardial Sympathetic Innervation as Evaluated by Cardiac I-123 mIBG Imaging?","authors":"A. Mohammed, G. Jacobsen, K. Ananthasubramaniam","doi":"10.4236/WJNST.2016.63018","DOIUrl":"https://doi.org/10.4236/WJNST.2016.63018","url":null,"abstract":"Background: Altered myocardial sympathetic innervation activity (AMSI) is known to be present in systolic heart failure patients (SHF) and recently SPECT imaging using I-123 mIBG heart to mediastinum (H/M) ratio <1.6 has been shown to predict MACE in the ADMIRE-HF trial. Left ventricular mechanical dyssynchrony (LVMD) is known to be present in a substantial number of SHF patients and has been studied mainly to guide CRT therapy. Recently gated SPECT has shown promise to provide an accurate assessment of LVMD. It remains unclear how the combination of AMSI and LVMD collectively affect clinical outcomes and other cardiovascular parameters. Objectives: The objectives are to examine the clinical characteristics and incremental prognostic value for MACE of LVMD determined by SPECT in SHF patients with or without abnormal cardiac MIBG uptake (H/M ratio < 1.6). Methods: Out of 30 SHF patients who participated from our institution in the ADMIRE-HF trial studying MIBG based AMSI, we included 22 patients with abnormal MIBG H/M ratio of <1.6. We performed gated SPECT LVMD analysis on these patients using the Emory Cardiac Toolbox. The 2 SPECT variables for LVMD assessed were histogram bandwidth and phase standard deviation both of which assess the extent of dispersion of LV activation during contraction as a marker of LVMD. Patients were followed up for a mean period of 6 years. The primary end point was mortality from any cause and secondary end point was heart failure admission or myocardial infarction or ICD shock. Results: 2 Groups were defined: Group A: n = 17 with H/M MIBG ratio < 1.6 and +LVMD and Group B, n = 5 H/M MIBG ratio < 1.6 and −LVMD. Baseline characteristics, cardiac risk factors and medications were comparable between both groups. LVEF was lower and RBBB was less common in Group A. There was no statistical difference in achievement of primary or secondary end points in the two groups including death heart failure readmissions, ICD shocks or MI. Conclusions: In our pilot study, we did not find definitive value of adding SPECT based LVMD to abnormal cardiac MIBG imaging in SHF patients with regards to predicting outcomes. Although our sample size is too small to make any definitive conclusions, it is possible that LVMD works independently through different pathways in the progression of SHF and hence may not necessarily add incremental value to AMSI determination using MIBG.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70888846","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":"Measurement of Natural Radioactivity and Radon Exhalation Rate in Coal Ash Samples from a Thermal Power Plant","authors":"A. Boukhair, Laila Belahbib, Khadija Azkour, H. Nebdi, M. Benjelloun, A. Nourreddine","doi":"10.4236/WJNST.2016.63017","DOIUrl":"https://doi.org/10.4236/WJNST.2016.63017","url":null,"abstract":"Coal is the main energy source for electricity generation in the world. In Morocco, 37% of electricity generation comes from combustion coal in thermal power plants. This combustion process generates large amounts of fly and bottom ashes. In recent years, these ashes became a great topic of interest because of their different uses and especially in construction materials. In this work, we assess radiation risks due to natural radioactivity in samples of fly and bottom ashes collected from JLEC (Jorf Lasfar Energy Company) thermal power plant, and different analyses are performed through two nuclear techniques such as gamma spectrometry and alpha dosimetry based on the use of LR115 films detectors. Our analysis shows that 226 Ra activities and 232 Th in both ash samples are well above the permissible activity. The values of the external risk index (Hex) and internal one (Hin) for these ashes are below unity, with the exception of 1.28 in fly ash for Hin. The obtained values for the equivalent radium Raeq and annual effective doses Ė in fly and bottom ashes are 324 Bq/kg and 210 Bq/kg, and 0.18 mSv/y and 0.11 mSv/y, respectively. The surface radon exhalation rates for the samples of fly and bottom ashes are 276 mBq • m −2 • h −1 and 381 mBq • m −2 • h −1 , respectively. Based on these results, we have shown that fly ash and bottom one from thermal power plant JLEC didn't have, in any case, a health risk to the public so it can be effectively used in various construction activities.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70888917","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":"Analytical and Computational Analysis of Flow Splitting in Multiple, Parallel Channels Systems","authors":"A. Lazarte, J. Ferreri","doi":"10.4236/WJNST.2016.63019","DOIUrl":"https://doi.org/10.4236/WJNST.2016.63019","url":null,"abstract":"Previous analytical results on flow splitting are generalized to consider \u0000multiple boiling channels systems. The analysis is consistent with the \u0000approximations usually adopted in the use of systems codes (like RELAP5 and TRACE5, among others) commonly applied to perform \u0000safety analyses of nuclear power \u0000plants. The problem is related to multiple, identical, parallel boiling \u0000channels, connected through common plena. A theoretical model limited in \u0000scope explains this flow splitting without \u0000reversal. The unified analysis performed and the confirmatory computational \u0000results found are summarized in this \u0000paper. New maps showing the zones where this behavior is predicted are also shown considering again twin \u0000pipes. Multiple pipe systems have been found not easily amenable for \u0000analytical analysis when dealing with more than four parallel pipes. However, \u0000the particular splitting found (flow along N pipes dividing in one standalone \u0000pipe flow plus N -1 identical pipe flows) has been verified up to fourteen pipes, involving \u0000calculations in systems with even and odd number of pipes using the RELAP5 systems \u0000thermal-hydraulics code.","PeriodicalId":61566,"journal":{"name":"核科学与技术国际期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70888461","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}