WorldWideScience

Sample records for oxidation states present

  1. Present State Examination

    DEFF Research Database (Denmark)

    Pedersen, Kamilla; Bertelsen, Aksel

    Present State Examination (PSE) 5. udgave er en revideret version af speciallæge i psykiatri Aksel Bertelsens oprindelige materiale. Aksel Bertelsen er ophavsmand til PSE og til den danske udgave af ICD-10. Revisionen omfatter et forbedret layout, en modernisering af sproget, tilføjelse af...

  2. Present state of reprocessing

    International Nuclear Information System (INIS)

    Huppert, K.L.

    1977-01-01

    The operation of several reprocessing plants - industrial size and pilot plants - has made it possible to build up substantial experience in the processing of irradiated fuels. More than 28,000 tons of fuels from gas-graphite reactors were processed on an industrial basis in Britain and France. For the treatment of both metallic fuels and high burn-up UO 2 -fuels, a solvent extraction process is applied which is based on the Purex process with a TBP kerosene mixture as extractant. A shear-leach technique is used for the break-down of the bundle elements and dissolution of the uranium oxide in nitric acid. Mechanically agitated extractors and pulsed columns have proved to be reliable equipment. The products are uranyl nitrate and plutonium nitrate. Process chemicals are recycled to minimize the volume of radioactive waste and precautions are taken to prevent uncontrolled escape of radioactivity. The technical status will be described as well as experience from pilot operation. (orig.) [de

  3. United States panel presentations

    International Nuclear Information System (INIS)

    Beyea, J.

    1990-01-01

    Before I begin I have to make a disclaimer. That is that I am going to be talking about public perception because I think that is very important. But I do not want to give the impression that I think the public is wrong. I happen to agree with the public's perception of nuclear power, and I want to make that clear. I do not like the current generation of nuclear plants as I have made clear in many statements that I have made. On the other hand, in the long term, I feel that we have only two choices on the supply side, and that is nuclear power and solar electricity. And although I think solar electricity has the best chance, I am realistic enough to know that technologies do not always work the way I want. And so I think it is necessary to have at least some kind of nuclear option available. On the other hand, I do not think just any kind of nuclear technology will do. I want to talk to you about the conditions that I think you have to take into account when you try to design reactors that are publicly acceptable. I look at this as an insurance policy. Again, I do not want to be misquoted: I think nuclear power should be considered as an insurance policy, not as our first line of defense. Having made those disclaimers, what we need to do is set out a problem statement. The problem statement I set out is, 'How could one design and demonstrate a nuclear reactor that would regain public confidence in the United States, if one chose to do that?' By regaining confidence, I mean regaining sufficient confidence to site reactors at a number of locations. It is a pretty heavy task because the public cannot judge the technical issues. They have to judge the players by their characters and their histories, just as the way we calibrate anyone that knows things that we do not. I have three theses that I think are crucial. The first is that people do not believe in the claims of advocates, of any point of view, not just nuclear power, once the advocates have been proved wrong on

  4. The Present State of Behaviorism

    Science.gov (United States)

    Mowrer, O. Hobart

    1976-01-01

    Assesses the present status of behaviorism by dividing this study into an evaluation of Behaviorism 1, based explicitly on Pavlov's conception of conditioned-response learning, and Behaviorism 11, single-handedly launched and almost completely dominanted by Professor B. F. Skinner. (Author/RK)

  5. Controlled thermonuclear fusion. Present state and prospective

    International Nuclear Information System (INIS)

    Consoli, T.

    1976-01-01

    The interest of thermonuclear fusion for energy production is underlined. The present state of the research in this field is presented, emphasis being given to Tokamak configurations. The problems concerning confinement and additional heating in these devices are presented [fr

  6. Manipulating affective state using extended picture presentations.

    Science.gov (United States)

    Sutton, S K; Davidson, R J; Donzella, B; Irwin, W; Dottl, D A

    1997-03-01

    Separate, extended series of positive, negative, and neutral pictures were presented to 24 (12 men, 12 women) undergraduates. Each series was presented on a different day, with full counterbalancing of presentation orders. Affective state was measured using (a) orbicularis oculi activity in response to acoustic startle probes during picture presentation, (b) corrugator supercilii activity between and during picture presentation, and (c) changes in self-reports of positive and negative affect. Participants exhibited larger eyeblink reflex magnitudes when viewing negative than when viewing positive pictures. Corrugator activity was also greater during the negative than during the positive picture set, during both picture presentation and the period between pictures. Self-reports of negative affect increased in response to the negative picture set, and self-reports of positive affect were greatest following the positive picture set. These findings suggest that extended picture presentation is an effective method of manipulating affective state and further highlight the utility of startle probe and facial electromyographic measures in providing on-line readouts of affective state.

  7. Present state of development of uranium enrichment

    International Nuclear Information System (INIS)

    1979-01-01

    The pilot plant for uranium enrichment started the operation on September 12, 1979. The pilot plant has been constructed by the Power Reactor and Nuclear Fuel Development Corp. in Ningyo Pass, Okayama Prefecture. 7000 centrifugal separators will be installed by mid 1981, and yearly production of 70 t SWU is expected. The Uranium Enrichment Committee of Japan Atomic Industrial Forum has made the proposal on the method of forwarding the development of uranium enrichment in Japan to Atomic Energy Commission and related government offices in December, 1978. This survey summarized the trends of uranium enrichment in Japan and foreign countries and the problems about nuclear non-proliferation, and provides with the reference materials. The demand and supply of uranium enrichment in the world, the present states and plans in USA, Europe, USSR and others, the demand and supply of uranium enrichment and the measures for securing it in Japan, the present state and future plan of uranium enrichment project in Japan, the international regulation of uranium enrichment, the recent policy of USA and INFCE, and the trend of the regulation of utilizing enriched uranium are described. Moreover, the concept of separation works in uranium enrichment and the various technologies of separation are explained. (Kako, I.)

  8. Oxidation-state maxima in plutonium chemistry

    International Nuclear Information System (INIS)

    Silver, G.L.

    2013-01-01

    Maxima in the fractions of the trivalent and hexavalent oxidation states of plutonium are inherent in the algebra of its disproportionation reactions. The maxima do not support overall disproportionation equations as satisfactory representations of aqueous plutonium. (author)

  9. Russian State Leveling Network (present and future)

    Science.gov (United States)

    Mazurova, Elena; Kopeikin, Sergei; Karpik, Aleksander

    2017-04-01

    In August 2016 the sixth session of the United Nations Committee of Experts of Global Geospatial Information Management (UN-GGIM) endorsed the roadmap for the development of a Global Geodetic Reference Frame (GGRF) and urged countries to join efforts for its creation. In response to the UN appeal in this article describes the current state of the high-precision Leveling Network in Russia and prospects of its development. In this paper, we consider projects related to the construction of new high-precision leveling lines by the classical methods, as well as issues of creating high-precision leveling network, associated with the development and implementation of a fundamentally new method of determining heights in geodesy - chronometric leveling based on the application of quantum metrology of time and the fundamental laws of general relativity. Keywords: leveling network, chronometric leveling, quantum metrology of time, the general theory of relativity.

  10. Neutron scattering: history, present state and perspectives

    International Nuclear Information System (INIS)

    Belushkin, A.V.

    1999-01-01

    The paper reminds some milestones in development of condensed matter research with neutrons. Present status of the investigations in this field is briefly outlined. An analysis is given on the situation and future prospects in different neutron sources development in Russia and in the world. The next generation neutron sources projects in Japan, USA and Europe are reviewed

  11. Present state of radiography and connected techniques

    International Nuclear Information System (INIS)

    Boutaine, J.L.

    1991-01-01

    In this paper are developed the different sources employed in non destructive testing using ionizing radiations and the different usable systems of detection. Are also presented few examples showing the compared interests of radiographic or radiometric control methods. 21 refs [fr

  12. Present state and development of positron tomographs

    International Nuclear Information System (INIS)

    Allemand, R.; Gariod, R.; Laval, M.; Tournier, F.

    1979-01-01

    This document presents the main characteristics of positron tomographs and analyses the relative importance of the parameters to be taken into consideration in the design of a tomograph: on the one hand, the physical parameters linked to the measurement of the annihilation photons by time coincidence and, on the other, the geometrical and technological parameters of prime importance in minimizing the many spurious effects. The last part endeavours to show this sort of instrumentation has evolved. Using the results obtained in our laboratory by mathematical simulation, the expected advantages are presented on the picture quality of the time of flight measurement of annihilation photons. Where the physical aspects of this method are concerned, the advantage of using cesium fluoride as scintillator is demonstrated [fr

  13. Phytotherapy: Present State of the Issue

    Directory of Open Access Journals (Sweden)

    L. R. Selimzianova

    2016-01-01

    Full Text Available Phytotherapy is one of the oldest treatment methods. Studies and conclusions of the World Health Organization (WHO Expert evidence of the trend towards greater demand for alternative treatments, including herbal medicine. The article presents such actual data on the issue under review as herbal preparations use at the present stage, frequency of and reasons for the use of medicinal plants in the world pediatric practice. There is a review of the WHO documents on quality assessment, harvesting, preparation and use of vegetable raw materials in the article. It also highlights the key provisions of the WHO strategy for ethnoscience in 2014–2023. There also is data on the properties of one of the plant-based drugs components and results of clinical trials of its effectiveness in children.

  14. Present state of backend in Taiwan

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

    As Taiwan is poor in its energy source as well as Japan is, nuclear power generation is one of important energy sources. Management and disposal (backend) of radioactive wastes accompanied with application to nuclear generation is a large problem for Taiwan which had 36,000 square kilometer of national area (about twice area of Shikoku in Japan) than that for Japan. In Taiwan, as the radioactive waste management policy (RWMP) was established in 1977 to arrange a basic indication of the backend policy, final disposal sites for both low and high level radioactive wastes (spent fuel) are not specified yet. For management of low level radioactive waste, the Taiwan Electric Power Corp. (TPC) reported the most promising area for the final disposal site to Taiwan Committee of Atomic Energy on February, 1998. And, for the high level radioactive waste, TPC intends to specify the final disposal site in 2016, to be under selection of site on aiming at beginning of its operation on 2032. And, on the backend policy in Taiwan its reprocessing option has not been abandoned yet, to remain feasibility of option in disposal of the low level radioactive waste on abroad. Here was introduced on present condition of the backend in Taiwan. (G.K.)

  15. Thermodynamic Ground States of Complex Oxide Heterointerfaces

    DEFF Research Database (Denmark)

    Gunkel, F.; Hoffmann-Eifert, S.; Heinen, R. A.

    2017-01-01

    The formation mechanism of 2-dimensional electron gases (2DEGs) at heterointerfaces between nominally insulating oxides is addressed with a thermodynamical approach. We provide a comprehensive analysis of the thermodynamic ground states of various 2DEG systems directly probed in high temperature...

  16. Higher Americium Oxidation State Research Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Goff, George S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shehee, Thomas C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hobbs, David T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-12-18

    The partitioning of hexavalent Am from dissolved nuclear fuel requires the ability to efficiently oxidize Am(III) to Am(VI) and to maintain that oxidation state for a length of time sufficient to perform the separation. Several oxidants have been, or are being developed. Chemical oxidants include Ag-catalyzed ozone, Ag-catalyzed peroxydisulfate, Cu(III) periodate, and sodium bismuthate. Hexavalent americium has also now successfully been prepared by electrolysis, using functionalized electrodes. So-called auto-reduction rates of Am(VI) are sufficiently slow to allow for separations. However, for separations based on solvent extraction or ion exchange using organic resins, the high valence state must be maintained under the reducing conditions of the organic phase contact, and a holding oxidant is probably necessary. Until now, only Cu(III) periodate and sodium bismuthate oxidation have been successfully combined with solvent extraction separations. Bismuthate oxidation provided the higher DAm, since it acts as its own holding oxidant, and a successful hot test using centrifugal contactors was performed. For the other oxidants, Ag-catalyzed peroxydisulfate will not oxidize americium in nitric acid concentrations above 0.3 M, and it is not being further investigated. Peroxydisulfate in the absence of Ag catalysis is being used to prepare Am(V) in ion exchange work, discussed below. Preliminary work with Ag-catalyzed ozone has been unsuccessful for extractions of Am(VI) from 6.5 M HNO3, and only one attempt at extraction, also from 6.5 M HNO3, using the electrolytic oxidation has been attempted. However, this high acid concentration was based on the highest Am extraction efficiency using the bismuthate oxidant; which is only sparingly soluble, and thus the oxidation yield is based on bismuthate solubility. Lower acid concentrations may be sufficient with alternative oxidants and work with Ag-ozone, Cu(III) and electrolysis is on-going. Two non

  17. Photochemical oxidants: state of the science.

    Science.gov (United States)

    Kley, D; Kleinmann, M; Sanderman, H; Krupa, S

    1999-01-01

    Atmospheric photochemical processes resulting in the production of tropospheric ozone (O(3)) and other oxidants are described. The spatial and temporal variabilities in the occurrence of surface level oxidants and their relationships to air pollution meteorology are discussed. Models of photooxidant formation are reviewed in the context of control strategies and comparisons are provided of the air concentrations of O(3) at select geographic locations around the world. This overall oxidant (O(3)) climatology is coupled to human health and ecological effects. The discussion of the effects includes both acute and chronic responses, mechanisms of action, human epidemiological and plant population studies and briefly, efforts to establish cause-effect relationships through numerical modeling. A short synopsis is provided of the interactive effects of O(3) with other abiotic and biotic factors. The overall emphasis of the paper is on identifying the current uncertainties and gaps in our understanding of the state of the science and some suggestions as to how they may be addressed.

  18. Plutonium disproportionation. Hydrolysis and local oxidation-state maxima

    International Nuclear Information System (INIS)

    Silver, G.L.

    2014-01-01

    Local maxima in the fractions of the trivalent and hexavalent oxidation states are inherent in the algebra of Pu disproportionation reactions. A new method predicts the pH and the oxidation-state fractions at maximum. Tabulated results illustrate the effects of the Pu oxidation number and Pu(IV) hydrolysis on the maxima. This method suggests a new laboratory approach for discovering Pu oxidation-state maxima. (author)

  19. Thermogravimetric study of reduction of oxides present in oxidized nickel-base alloy powders

    Science.gov (United States)

    Herbell, T. P.

    1976-01-01

    Carbon, hydrogen, and hydrogen plus carbon reduction of three oxidized nickel-base alloy powders (a solid solution strengthened alloy both with and without the gamma prime formers aluminum and titanium and the solid solution strengthened alloy NiCrAlY) were evaluated by thermogravimetry. Hydrogen and hydrogen plus carbon were completely effective in reducing an alloy containing chromium, columbium, tantalum, molybdenum, and tungsten. However, with aluminum and titanium present the reduction was limited to a weight loss of about 81 percent. Carbon alone was not effective in reducing any of the alloys, and none of the reducing conditions were effective for use with NiCrAlY.

  20. Pentavalent Uranium Chemistry - Synthetic Pursuit Of A Rare Oxidation State

    Energy Technology Data Exchange (ETDEWEB)

    Graves, Christopher R [Los Alamos National Laboratory; Kiplinger, Jaqueline L [Los Alamos National Laboratory

    2009-01-01

    This feature article presents a comprehensive overview of pentavalent uranium systems in non-aqueous solution with a focus on the various synthetic avenues employed to access this unusual and very important oxidation state. Selected characterization data and theoretical aspects are also included. The purpose is to provide a perspective on this rapidly evolving field and identify new possibilities for future developments in pentavalent uranium chemistry.

  1. Risk factors, pre-presentation management and clinical state of ...

    African Journals Online (AJOL)

    2017-08-23

    Aug 23, 2017 ... based on provision of clean water sources, basic hygiene. CC –BY ... clinical state at presentation, management, and outcome were documented. Data was entered ... WHBPF = Washes hands before preparing food. WHBF =.

  2. Film Music: The Material, Literature and Present State of Research.

    Science.gov (United States)

    Marks, Martin

    1982-01-01

    A comprehensive look at the neglected art of film music. Examines the nature of the medium, the literature (how others have wrestled with film music's recalcitrant materials), and the present state of research into film music. Includes a bibliography. (PD)

  3. The State Regulation of Innovation Activity at the Present Stage

    Directory of Open Access Journals (Sweden)

    Qoqiauri Lamara G.

    2017-06-01

    Full Text Available The article discusses the necessity of state regulation in the field of development of innovations and technologies at the present stage. The main directions of the state innovation policies in developed countries of the world are studied and analyzed. Special attention is paid to the objectives of the national strategy for development of science and innovations and to searching the ways for fulfilling this strategy. Apart from these specific problems, the work considers the issue of the state regulation and support of further introduction of innovations and increase of the so called “entrepreneurial” role of the state.

  4. Oxidative Stress and Heart Failure in Altered Thyroid States

    Directory of Open Access Journals (Sweden)

    Pallavi Mishra

    2012-01-01

    Full Text Available Increased or reduced action of thyroid hormone on certain molecular pathways in the heart and vasculature causes relevant cardiovascular derangements. It is well established that hyperthyroidism induces a hyperdynamic cardiovascular state, which is associated with a faster heart rate, enhanced left ventricular systolic and diastolic function whereas hypothyroidism is characterized by the opposite changes. Hyperthyroidism and hypothyroidism represent opposite clinical conditions, albeit not mirror images. Recent experimental and clinical studies have suggested the involvement of ROS tissue damage under altered thyroid status. Altered-thyroid state-linked changes in heart modify their susceptibility to oxidants and the extent of the oxidative damage they suffer following oxidative challenge. Chronic increase in the cellular levels of ROS can lead to a catastrophic cycle of DNA damage, mitochondrial dysfunction, further ROS generation and cellular injury. Thus, these cellular events might play an important role in the development and progression of myocardial remodeling and heart failure in altered thyroid states (hypo- and hyper-thyroidism. The present review aims at elucidating the various signaling pathways mediated via ROS and their modulation under altered thyroid state and the possibility of antioxidant therapy.

  5. The brown coal. Present state and development perspectives

    International Nuclear Information System (INIS)

    Wagenknecht, J.

    1994-01-01

    A present state of Polish power plants fueled by brown coal is presented. Their economic results are compared with the achievements of power stations fueled by black coal. The basic data concerning brown coal reserves, production and consumption are given. The problems of environmental protection are discussed. The different applications of brown coal are mentioned. Its importance for energy balance is stressed. 6 tabs

  6. Present state of beech bark disease in Germany

    Science.gov (United States)

    Klaus J. Lang

    1983-01-01

    Beech bark disease can be found at present time in young and old stands (20-150 years old) of Fagus sylvatica. The present state of the disease may be described as "normal" and apart from some cases, it is no threat to the existence of the stands.

  7. Changing climate states and stability: from Pliocene to present

    Energy Technology Data Exchange (ETDEWEB)

    Livina, V.N.; Lenton, T.M. [University of East Anglia, School of Environmental Sciences, Norwich (United Kingdom); Kwasniok, F. [University of Exeter, College of Engineering, Mathematics and Physical Sciences, Exeter (United Kingdom); Lohmann, G. [Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany); Kantelhardt, J.W. [Martin-Luther-Universitaet Halle-Wittenberg, Institute of Physics, Theory group, Halle (Germany)

    2011-12-15

    We present a recently developed method of potential analysis of time series data, which comprises (1) derivation of the number of distinct global states of a system from time series data, and (2) derivation of the potential coefficients describing the location and stability of these states, using the unscented Kalman filter (UKF). We test the method on artificial data and then apply it to climate records spanning progressively shorter time periods from 5.3 Myr ago to the recent observational record. We detect various changes in the number and stability of states in the climate system. The onset of Northern Hemisphere glaciation roughly 3 Myr BP is detected as the appearance of a second climate state. During the last ice age in Greenland, there is a bifurcation representing the loss of stability of the warm interstadial state, followed by the total loss of this state around 25 kyr BP. The Holocene is generally characterized by a single stable climate state, especially at large scales. However, in the historical record, at the regional scale, the European monthly temperature anomaly temporarily exhibits a second, highly degenerate (unstable) state during the latter half of the eighteenth century. At the global scale, temperature is currently undergoing a forced movement of a single stable state rather than a bifurcation. The method can be applied to a wide range of geophysical systems with time series of sufficient length and temporal resolution, to look for bifurcations and their precursors. (orig.)

  8. Influence of oxidation state on the pH dependence of hydrous iridium oxide films

    International Nuclear Information System (INIS)

    Steegstra, Patrick; Ahlberg, Elisabet

    2012-01-01

    Many electrochemical reactions taking place in aqueous solution consume or produce protons. The pH in the diffusion layer can therefore be significantly altered during the reaction and there is a need for in situ pH measurements tracing this near surface pH. In the present paper the rotating ring disc technique was used to measure near surface pH changes during oxygen reduction, utilising hydrous iridium oxide as the pH sensing probe. Before such experiments a good understanding of the pH sensing properties of these films is required and the impact of the oxidation state of the film on the pH sensing properties was investigated as well as the influence of solution redox species. The pH sensitivity (depicted by dE/dpH) was found to depend on the average oxidation state of the film in a manner resembling the cyclic voltammetry response. In all cases the pH response is “supernernstian” with more than one proton per electron. The origin of this behaviour is discussed in the context of acid-base properties of the film and the existence of both hydrous and anhydrous oxide phases. The pH response depends also on the redox properties of the solution but can be optimised for various purposes by conditioning the film at different potentials. This was clearly illustrated by adding hydrogen peroxide, an intermediate in the oxygen reduction reaction, to the solution. It was shown that hydrous iridium oxide can be used as a reliable in situ pH sensor provided that care is taken to optimise the oxidation state of the film.

  9. Predicting spent fuel oxidation states in a tuff repository

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1987-01-01

    Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the tuffaceous rocks at Yucca Mountain as a waste repository for spent fuel disposal. The oxidation state of the LWR spent fuel in the moist air environment of a tuff repository could be a significant factor in determining its leaching and dissolution characteristics. Predictions as to which oxidation states would be present are important in analyzing such a repository and thus the present study was undertaken. A set of TGA (thermogravimetric analysis) tests were conducted on well-controlled samples of irradiated PWR fuel with time and temperature as the only variables. The tests were conducted between 140 and 225 0 C for a duration up to 2200 hours. The weight gain curves were analyzed in terms of diffusion through a layer of U 3 O 7 , diffusion into the grains to form a solid solution, a simplified empirical representation of a combination of grain boundary diffusion and bulk grain oxidation. Reaction rate constants were determined in each case, but analysis of these data could not establish a definitive mechanism. 21 refs., 10 figs., 3 tabs

  10. The present state of social science research in Asia

    NARCIS (Netherlands)

    Lieten, G.K.

    2014-01-01

    The first pan-Asia conference ‘Status and Role of Social Science Research in Asia, Emerging Challenges and Policy Issues’ (New Delhi, 13-15 March 2014), with representatives from 24 countries in Asia and some non-Asian countries, was intended to assess the present state of social science research in

  11. Study on the solid state chemistry of ternary uranium oxides

    International Nuclear Information System (INIS)

    Yamashita, Toshiyuki

    1988-03-01

    With the increase of burnup of uranium oxide fuels, various kinds of fission products are formed, and the oxygen atoms combined with the consumed heavy atoms are freed. The solid state chemical and/or thermodynamic properties of these elements at high temperatures are complex, and have not been well clarified. In the present report, an approach was taken that the chemical interactions between UO 2 and these fission products can be regarded as causing overlapped effects of composing ternary uranium oxides, and formation reactions and phase behavior were studied for several ternary uranium oxides with typical fission product elements such as alkaline earth metals and rare earth elements. Precise determination methods for the composition of ternary uranium oxides were developed. The estimated accuracies for x and y values in M y U 1-y O 2+x were ± 0.006 and ± 0.004, respectively. The thermodynamic properties and the lattice parameters of the phases in the Ca-U-O and Pr-U-O systems were discussed in relation to the composition determined by the methods. Crystal structure analyses of cadmium monouranates were made with X-ray diffraction method. (author) 197 refs

  12. Studies of the Tc oxidation states in humic acid solutions

    International Nuclear Information System (INIS)

    Wang Bo; Liu Dejun; Yao Jun

    2010-01-01

    The oxidation state is an important aspect of the speciation of Tc in groundwater that contained organic substances due to it control the precipitation, complexation, sorption and colloid formation behavior of the Tc under HWL geological disposal conditions. In present work, the oxidation states of Tc were investigated using the LaCl 3 coagulation method and solution extraction method in aqueous solutions in which the humic acid concentration range is from 0 to 20 mg L -1 and the Tc (Ⅶ) concentration range is about 10 -8 mol l -1 . The radiocounting of 99 Tc was determined using liquid scintillation spectrometry. The humic acid will influence the radiocounting ratio of 99 Tc apparently, however, the quenching effect can be restrained once keep the volume of the cocktail to about twenty times of the sample volume. The LaCl 3 coagulation methods were carried out for the investigation of Tc oxidation states in humic acid aqueous systems at about pH 8. The tetraphenylarsonium chloride (IPA)-chloroform extraction method was used also simultaneously to investigation the concentrations of Tc (Ⅳ) and Tc (Ⅶ) for the availability of the LaCl 3 precipitation method, and the experimental results demonstrate that tetravalent technetium and pertechnetate concentrations are well agreement with the LaCl 3 precipitation method. These two experimental results demonstrated that Tc (Ⅶ) is very stable in the Tc (Ⅶ)-humic acid system during a 350 days experimental period, and the Tc (Ⅳ) concentrations are very lower, that is indicate that there didn't oxidizing reactions between the Fluka humic acid and Tc (Ⅶ) in aqueous solutions under anaerobic conditions. That is means the presence of humic acids even in anaerobic groundwater is disadvantage for the retardance of radionuclides. (authors)

  13. Studies of Tc oxidation states in humic acid solutions

    International Nuclear Information System (INIS)

    Wang Bo; Liu Dejun; Yao Jun

    2011-01-01

    The oxidation state of Tc is an important aspect of the speciation in groundwater which contained organic substances due to it control the precipitation, complexation, sorption and colloid formation behavior of the Tc under HWL geological disposal conditions. In present work, the oxidation states of Tc were investigated using the LaCl 3 coagulation method and solution extraction method in aqueous solutions in which the humic acid concentration range is from 0 to 20 mg/L and the Tc (VII) concentration is about 10 -8 mol/L. The radiocounting of 99 Tc was determined using liquid scintillation spectrometry. The humic acid will influence the radiocounting ratio of 99 Tc apparently, however, the quenching effect can be restrained once keep the volume of the cocktail to about twenty times of the sample volume. The LaCl 3 coagulation method was carried out for the investigation of Tc oxidation states in humic acid aqueous systems at about pH 8. The tetraphenylarsonium chloride (TPA)-chloroform extraction method was used also simultaneously to investigation the concentrations of Tc (IV) and Tc (VII) for the availability of the LaCl 3 precipitation method, and the experimental results demonstrate that tetravalent technetium and pertechnetate concentration are well agreement with the LaCl 3 precipitation method. These two experimental results demonstrated that Tc (VII) is very stable in the Tc (VII)-humic acid system during a 350 days experimental period, and the Tc (IV) concentrations are very lower, that is indicate that there didn't oxidizing reactions between the Fluka humic acid and Tc (VII) in aqueous solutions under anaerobic conditions. That means the presence of humic acids even in anaerobic groundwater is disadvantage for the retardance of radionuclides. (authors)

  14. Carbon monoxide oxidation over three different states of copper: Development of a model metal oxide catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Jernigan, Glenn Geoffrey [California Univ., Berkeley, CA (United States). Dept. of Chemistry

    1994-10-01

    Carbon monoxide oxidation was performed over the three different oxidation states of copper -- metallic (Cu), copper (I) oxide (Cu2O), and copper (II) oxide (CuO) as a test case for developing a model metal oxide catalyst amenable to study by the methods of modern surface science and catalysis. Copper was deposited and oxidized on oxidized supports of aluminum, silicon, molybdenum, tantalum, stainless steel, and iron as well as on graphite. The catalytic activity was found to decrease with increasing oxidation state (Cu > Cu2O > CuO) and the activation energy increased with increasing oxidation state (Cu, 9 kcal/mol < Cu2O, 14 kcal/mol < CuO, 17 kcal/mol). Reaction mechanisms were determined for the different oxidation states. Lastly, NO reduction by CO was studied. A Cu and CuO catalyst were exposed to an equal mixture of CO and NO at 300--350 C to observe the production of N2 and CO2. At the end of each reaction, the catalyst was found to be Cu2O. There is a need to study the kinetics of this reaction over the different oxidation states of copper.

  15. Floods of 2005 in the State of Veracruz Book Presentation

    Science.gov (United States)

    Tejeda, A.; Ochoa, C.

    2007-05-01

    During October of 2005, when hurricane Stan caused destruction to the center and south of the state of Veracruz, a book was elaborated. The book's called Floods of 2005 in the state of Veracruz and contains twenty chapters. The first three chapters conform a panoramic of the book and two historical and archaeological contributions. One second part takes care of the natural phenomena of floods: meteorological, hydrological aspects, and biodiversity. Economic and social aspects are the largest contents of the volume, which concludes with reflections towards the future: the possible consequences of global climatic change, the chemical component that's not considered in the evaluation and prevention of risks by hidrometeorogical phenomena, and the duty of political prevention of disasters. The frame reference for the book is through a discussion of all kind of contributions. Which means that this book presentation is for the geophysicists community of Mexico. Keywords: Floods, state of Veracruz, risks and disasters.

  16. The present state of laser isotope separation of uranium

    International Nuclear Information System (INIS)

    Tashiro, Hideo; Nemoto, Koshichi.

    1994-01-01

    As the methods of uranium enrichment, gas diffusion method and centrifugal separation method in which power consumption is less and the cost is low have been carried out. On the other hand, as the future technology, the research and development of laser isotope separation technology have been carried out. There are the atomic laser separation process in which the laser beam of visible light is irradiated to atomic state uranium and the molecular laser separation process in which far infrared laser beam is irradiated to uranium hexafluoride molecules. The atomic process is divided into three steps, that is, the processes of uranium evaporation, the reaction of uranium with laser beam and the recovery of enriched uranium. The principle of the laser separation is explained. The state of development of laser equipment and separation equipment is reported. The principle and the present state of development of the molecular separation process which consists of the cooling of UF 6 gas, the generation of high power 16 μm laser pulses and the collection of the reaction product are explained. The present state of both processes in foreign countries is reported. (K.I.)

  17. Karst mapping in the United States: Past, present and future

    Science.gov (United States)

    Weary, David J.; Doctor, Daniel H.

    2015-01-01

    The earliest known comprehensive karst map of the entire USA was published by Stringfield and LeGrand (1969), based on compilations of William E. Davies of the U.S. Geological Survey (USGS). Various versions of essentially the same map have been published since. The USGS recently published new digital maps and databases depicting the extent of known karst, potential karst, and pseudokarst areas of the United States of America including Puerto Rico and the U.S. Virgin Islands (Weary and Doctor, 2014). These maps are based primarily on the extent of potentially karstic soluble rock types, and rocks with physical properties conducive to the formation of pseudokarst features. These data were compiled and refined from multiple sources at various spatial resolutions, mostly as digital data supplied by state geological surveys. The database includes polygons delineating areas with potential for karst and that are tagged with attributes intended to facilitate classification of karst regions. Approximately 18% of the surface of the fifty United States is underlain by significantly soluble bedrock. In the eastern United States the extent of outcrop of soluble rocks provides a good first-approximation of the distribution of karst and potential karst areas. In the arid western states, the extent of soluble rock outcrop tends to overestimate the extent of regions that might be considered as karst under current climatic conditions, but the new dataset encompasses those regions nonetheless. This database will be revised as needed, and the present map will be updated as new information is incorporated.

  18. Present state and future of new energy technology development

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, N

    1976-08-01

    The Sunshine Project was begun in 1973 by the Japanese Ministry of Industry to investigate all alternative energy sources other than nuclear. The project is subdivided into four separate areas, those being solar energy, geothermal energy, liquefaction and gasification of coal, and hydrogen fuel. This article describes the present state of these technologies and their probable future development. Although hydrogen fuel and coal liquefaction/gasification are still in the basic research stage solar and geothermal technologies are already well developed.

  19. Development and Present Situation Analysis of Power Transformer State Maintenance

    Science.gov (United States)

    Lv, Sen; Li, Biao; Li, Huan

    2018-02-01

    The pivotal status of power transformer in the power system is one of the most important equipment. The safety and reliability of its operation is directly related to the safety and stability of power system. Based on the analysis of the present situation of power transformer state maintenance in home and abroad. The paper points out the deficiency of the current method and provides a theoretical basis for further research, which has a certain guiding significance.

  20. Democracy, justice and state of exception: past present

    Directory of Open Access Journals (Sweden)

    Tásso Araújo Brito

    2017-06-01

    Full Text Available Violence against portions of society, disbelief in democratic institutions and agents of the state who inflict torture against those who are in their custody are elements that corrode the Brazilian democracy. Between the past of the military-civilian dictatorship and the current moment we realize how practices that have been considered exceptions have become rules that affect the life of many Brazilian citizens. The present paper investigates these political experiences to ask which democracy have we been living in.

  1. Evolution, present state and future of the radiochromic dyeing films

    International Nuclear Information System (INIS)

    Villarreal B, J.E.

    2000-01-01

    The evolution of radiochromic films, their present state and their developing future are the object of this work. For this purpose a review of the evolution was realized and also of the present state of using the radiochromic dyeing films as tools to determine the absorbed doses distribution produces by beta emissor sources, beta-gamma, electrons and X-rays. In particular it is presented the development of radiochromic films type GafChromic that by their quality in terms of reproducibility, sensibility and high spatial resolution they have been converted in those films of greatest use so dominating market. Since one of the application fields more important of this type of films is clinical dosimetry, the more eminent applications in this area are presented, which the high resolution dosimetry that use GafChromic has been converted in a basic tool. On the other hand the scopes of this type of dosimetry and the possible development lines of dosimetry with radiochromic dyeing films are discussed. (Author)

  2. Present state and perspectives of RIA in obstetrics and gynecology

    International Nuclear Information System (INIS)

    Talas, M.; Fingerova, H.

    1979-01-01

    A survey is presented of RIA methods introduced by the authors in their laboratory in the course of the last eight years. The results obtained by these methods in various physiological and pathological states are evaluated. The authors point to the possibilities of effective use of RIA for diagnostic purposes in obstetrics and gynecology taking into account also economic and organizational aspects. The most important trends of the use of RIA are accentuated not only in gynecological endocrinology and obstetrics but also in some other related fields, especially in the diagnosis and treatment of malignant diseases. (author)

  3. Present state and perspectives of RIA in obstetrics and gynecology

    Energy Technology Data Exchange (ETDEWEB)

    Talas, M; Fingerova, H [Palackeho Univ., Olomouc (Czechoslovakia). Lekarska Fakulta

    1979-01-01

    A survey is presented of RIA methods introduced by the authors in their laboratory in the course of the last eight years. The results obtained by these methods in various physiological and pathological states are evaluated. The authors point to the possibilities of effective use of RIA for diagnostic purposes in obstetrics and gynecology taking into account also economic and organizational aspects. The most important trends of the use of RIA are accentuated not only in gynecological endocrinology and obstetrics but also in some other related fields, especially in the diagnosis and treatment of malignant diseases.

  4. Japanese superconducting maglev: Present state and future perspective

    Science.gov (United States)

    Takeda, Hiroshi

    1990-06-01

    Maglev (magnetic levitation vehicle) being developed as a new transportation means running at a speed of 500 km/h has various advantages in safety, mass transportation and less environment polution as well as high-speed. The development of this system is rapidly advancing into the practical stage, that is, the commercial stage of the maglev train as a mass transportation system for intercity high-speed service. This paper describes the present state of research and development as well as future prospects of maglev.

  5. Persistence of oxidation state III of gold in thione coordination

    Science.gov (United States)

    Jääskeläinen, Sirpa; Koskinen, Laura; Kultamaa, Matti; Haukka, Matti; Hirva, Pipsa

    2017-05-01

    Ligands N,N'-tetramethylthiourea and 2-mercapto-1-methyl-imidazole form stable Au(III) complexes [AuCl3(N,N'-tetramethylthiourea)] (1) and [AuCl3(2-mercapto-1-methyl-imidazole)] (2) instead of reducing the Au(III) metal center into Au(I), which would be typical for the attachment of sulfur donors. Compounds 1 and 2 were characterized by spectroscopic methods and by X-ray crystallography. The spectroscopic details were explained by simulation of the UV-Vis spectra via the TD-DFT method. Additionally, computational DFT studies were performed in order to find the reason for the unusual oxidation state in the crystalline materials. The preference for Au(III) can be explained via various weak intra- and intermolecular interactions present in the solid state structures. The nature of the interactions was further investigated by topological charge density analysis via the QTAIM method.

  6. Present state of nuclear power business in China

    International Nuclear Information System (INIS)

    Morokuzu, Muneo

    2011-01-01

    This article presented present state of nuclear power business in China based on latest information obtained at visit at nuclear power related facilities in December 2010. China Atomic Energy Authority (CAEA) promoted nuclear power, while National Nuclear Safety Administration (NNSA) was an independent regulatory body of nuclear power. Construction of nuclear power was promoted by three national nuclear engineering development corporations: China National Nuclear Corporation (CNNC), China Guangdon Nuclear Power Corporation (CGNPC) and State Nuclear Power Technology Corporation (SNPTC). In China, 13 nuclear power reactors were in operation and 27 under construction. Shortage of nuclear engineers became evident with rapid growth of nuclear power, which forced delay of nuclear power construction schedule. Future strategies of reactor type varied domestic, French and US ones respectively dependent on CNNC, CGNPC and SNPTC, CNNC seemed to change from third generation reactor (CNP 1000) to second one (CP 1000) due to regulatory licensing difficulty of NNSA. As for advanced reactor development, large scale PWR project, HTR project and FBR development project were proceeding. As HTR project was selected as high-priority project, an experimental reactor (HTR-10) was critical in 2000 and construction of demonstration reactor started in 2009. (T. Tanaka)

  7. Afterglow luminescence in sol-gel/Pechini grown oxide materials: persistence or phosphorescence process? (Conference Presentation)

    Science.gov (United States)

    Sontakke, Atul; Ferrier, Alban; Viana, Bruno

    2017-03-01

    Persistent luminescence and phosphorescence, both yields afterglow luminescence, but are completely different mechanisms. Persistent luminescence involves a slow thermal release of trapped electrons stored in defect states, whereas the phosphorescence is caused due to triplet to singlet transition [1,2]. Many persistent luminescence phosphors are based on oxide inorganic hosts, and exhibit long afterglow luminescence after ceasing the excitation. We observed intense and long afterglow luminescence in sol-gel/pechini grown inorganic oxides, and as a first interpretation thought to be due to persistence mechanism. However, some of these materials do not exhibit defect trap centers, and a detailed investigation suggested it is due to phosphorescence, but not the persistence. Phosphorescence is not common in inorganic solids, and that too at room temperature, and therefore usually misinterpreted as persistence luminescence [3]. Here we present a detailed methodology to distinguish phosphorescence from persistence luminescence in inorganic solids, and the process to harvest highly efficient long phosphorescence afterglow at room temperature. 1. Jian Xu, Setsuhisa Tanabe, Atul D. Sontakke, Jumpei Ueda, Appl. Phys. Lett. 107, 081903 (2015) 2. Sebastian Reineke, Marc A. Baldo, Scientific Reports, 4, 3797 (2014) 3. Pengchong Xue, Panpan Wang, Peng Chen, Boqi Yao, Peng Gong, Jiabao Sun, Zhenqi Zhang, Ran Lu, Chem. Sci. (2016) DOI: 10.1039/C5SC03739E

  8. Nutritional psychiatry: the present state of the evidence.

    Science.gov (United States)

    Marx, Wolfgang; Moseley, Genevieve; Berk, Michael; Jacka, Felice

    2017-11-01

    Mental illness, including depression, anxiety and bipolar disorder, accounts for a significant proportion of global disability and poses a substantial social, economic and heath burden. Treatment is presently dominated by pharmacotherapy, such as antidepressants, and psychotherapy, such as cognitive behavioural therapy; however, such treatments avert less than half of the disease burden, suggesting that additional strategies are needed to prevent and treat mental disorders. There are now consistent mechanistic, observational and interventional data to suggest diet quality may be a modifiable risk factor for mental illness. This review provides an overview of the nutritional psychiatry field. It includes a discussion of the neurobiological mechanisms likely modulated by diet, the use of dietary and nutraceutical interventions in mental disorders, and recommendations for further research. Potential biological pathways related to mental disorders include inflammation, oxidative stress, the gut microbiome, epigenetic modifications and neuroplasticity. Consistent epidemiological evidence, particularly for depression, suggests an association between measures of diet quality and mental health, across multiple populations and age groups; these do not appear to be explained by other demographic, lifestyle factors or reverse causality. Our recently published intervention trial provides preliminary clinical evidence that dietary interventions in clinically diagnosed populations are feasible and can provide significant clinical benefit. Furthermore, nutraceuticals including n-3 fatty acids, folate, S-adenosylmethionine, N-acetyl cysteine and probiotics, among others, are promising avenues for future research. Continued research is now required to investigate the efficacy of intervention studies in large cohorts and within clinically relevant populations, particularly in patients with schizophrenia, bipolar and anxiety disorders.

  9. Intestinal Oxidative State Can Alter Nutrient and Drug Bioavailability

    Directory of Open Access Journals (Sweden)

    Faria Ana

    2009-01-01

    Full Text Available Organic cations (OCs are substances of endogenous (e.g., dopamine, choline or exogenous (e.g., drugs like cimetidine origin that are positively charged at physiological ph. since many of these compounds can not pass the cell membrane freely, their transport in or out of cells must be mediated by specific transport systems. Transport by organic cation transporters (OCTs can be regulated rapidly by altering their trafficking and/or affinities in response to stimuli. However, for example, a specific disease could lead to modifications in the expression of OCTs. Chronic exposure to oxidative stress has been suggested to alter regulation and functional activity of proteins through several pathways. According to results from a previous work, oxidation-reduction pathways were thought to be involved in intestinal organic cation uptake modulation. The present work was performed in order to evaluate the influence of oxidative stressors, especially glutathione, on the intestinal organic cation absorption. For this purpose, the effect of compounds with different redox potential (glutathione, an endogenous antioxidant, and procyanidins, diet antioxidants was assessed on MPP+ (1-methyl-4-phenylpyridinium iodide uptake in an enterocyte cell line (Caco-2. Caco-2 cells were subcultured with two different media conditions (physiological: 5 mM glucose, referred as control cells; and high-glucose: 25 mM glucose, referred as HG cells. In HG cells, the uptake was significantly lower than in control cells. Redox changing interventions affected Mpp+ uptake, both in control and in high-glucose Caco-2 cells. Cellular glutathione levels could have an important impact on membrane transporter activity. The results indicate that modifications in the cellular oxidative state modulate MPP+ uptake by Caco-2 cells. Such modifications may reflect in changes of nutrient and drug bioavailability.

  10. PRESENTATION OF STATE SUPPORT (GRANTS IN ACCOUNTING POLICY OF POLAND

    Directory of Open Access Journals (Sweden)

    K. Zuk

    2014-01-01

    Full Text Available Since admission of Poland to the European Union Polish enterprises can make use of the state support in various forms including support in investments, investigations and developments, consulting, higher qualification, financing of exhibition participation, salary additional payments for invalid workers, repayment of loan portions. The purpose of the given publication is to make an analysis of accounting method for state support which is granted for an organization within the frameworks of the accounting policy depending on the obtained grants.Enterprises must select themselves a grant accounting form as in account books so while presenting financial reporting and these accounting and reporting forms must be reflected in the enterprise policy of accounting. The enterprise accounting policy indicates principles for creation of reserves and conditional obligations related with grants. Enterprises can use some simplifications and they can exclude creation of reserves and withhold conditional obligations concerning the grants if these measures are considered as insignificant.In accordance with the enterprise accounting policy account books must contain recordings on grant provision when a grant is transferred to the bank account or when an enterprise receives a written notice confirming final decision about payments from a financing institution. The accounting policy must determine principles of bank operation break-up on grant accounts and security system of data and files including accounting documents, accounts and other documents related to the obtained grant and the required archivation term

  11. Present states and views on vault storage systems

    International Nuclear Information System (INIS)

    Yoshimura, Eiji

    2003-01-01

    Storage capacity of spent nuclear fuel storage pools in nuclear power station is reaching to a condition near its limit, and under a condition inevitable on delay of the Pu-thermal utilization plan importance on interim storage of the spent nuclear fuels is further rising. In U.S.A., Germany, and so on, a condition incapable of presenting nuclear energy business itself without its intermediate storage is approaching, so in Japan it will also be a key to smoothly promote the nuclear energy business how the interim storage is used and operated. Under such condition, in Japan storage facilities using a system called by 'metal cask' are established at areas of nuclear power stations to begin their operations. As on the system expensive metal containers are used for storage in themselves, it has a demerit of its high cost. On the other hand, on foreign countries, a storing system called by concrete cask, horizontal silo, or vault is occupying its main stream. Here was introduced present states and future views on vault storage system. (G. K)

  12. Decommissioning in the United States - Past, present and future - 16318

    International Nuclear Information System (INIS)

    Devgun, Jas S.

    2009-01-01

    gearing up for the design and licensing of new reactors. Lessons from the past are useful in the development of such designs so that along with the other factors, the designs are optimized for eventual decommissioning as well. This paper provides an overview of the past reactor decommissioning, lessons learned from the past experience, and status of the current decommissioning activities and issues. It also presents some long term projections for the future of decommissioning in the United States. (authors)

  13. Non-equilibrium oxidation states of zirconium during early stages of metal oxidation

    International Nuclear Information System (INIS)

    Ma, Wen; Yildiz, Bilge; Herbert, F. William; Senanayake, Sanjaya D.

    2015-01-01

    The chemical state of Zr during the initial, self-limiting stage of oxidation on single crystal zirconium (0001), with oxide thickness on the order of 1 nm, was probed by synchrotron x-ray photoelectron spectroscopy. Quantitative analysis of the Zr 3d spectrum by the spectrum reconstruction method demonstrated the formation of Zr 1+ , Zr 2+ , and Zr 3+ as non-equilibrium oxidation states, in addition to Zr 4+ in the stoichiometric ZrO 2 . This finding resolves the long-debated question of whether it is possible to form any valence states between Zr 0 and Zr 4+ at the metal-oxide interface. The presence of local strong electric fields and the minimization of interfacial energy are assessed and demonstrated as mechanisms that can drive the formation of these non-equilibrium valence states of Zr

  14. A microbial-mineralization-inspired approach for synthesis of manganese oxide nanostructures with controlled oxidation states and morphologies

    Energy Technology Data Exchange (ETDEWEB)

    Oba, Manabu; Oaki, Yuya; Imai, Hiroaki [Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan)

    2010-12-21

    Manganese oxide nanostructures are synthesized by a route inspired by microbial mineralization in nature. The combination of organic molecules, which include antioxidizing and chelating agents, facilitates the parallel control of oxidation states and morphologies in an aqueous solution at room temperature. Divalent manganese hydroxide (Mn(OH){sub 2}) is selectively obtained as a stable dried powder by using a combination of ascorbic acid as an antioxidizing agent and other organic molecules with the ability to chelate to manganese ions. The topotactic oxidation of the resultant Mn(OH){sub 2} leads to the selective formation of trivalent manganese oxyhydroxide ({beta}-MnOOH) and trivalent/tetravalent sodium manganese oxide (birnessite, Na{sub 0.55}Mn{sub 2}O{sub 4}.1.5H{sub 2}O). For microbial mineralization in nature, similar synthetic routes via intermediates have been proposed in earlier works. Therefore, these synthetic routes, which include in the present study the parallel control over oxidation states and morphologies of manganese oxides, can be regarded as new biomimetic routes for synthesis of transition metal oxide nanostructures. As a potential application, it is demonstrated that the resultant {beta}-MnOOH nanostructures perform as a cathode material for lithium ion batteries. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Present state of Japan Nuclear Ship Development Agency

    International Nuclear Information System (INIS)

    Takada, Yoshio

    1981-01-01

    The Japan Nuclear Ship Development Agency held the annual report meeting on April 8, 1981. The main contents were the plan of research and development of nuclear ships hereafter, the present state of the repair works for the nuclear ship ''Mutsu'', the progress of the selection of the new home port and others. In the last year, the function of research was given to the Agency by the revision of the related law. The full-scale repair works for Mutsu were started in August, 1980, and various equipments and shields in the containment vessel and the upper shields of the containment vessel have been removed. Subsequently, new shields are being installed. According to the report by the committee of nuclear ship research and development, the development of Mutsu, which is valuable as the experimental ship, is continued. Moreover, it is proposed to do the research and development of an improved marine nuclear plant for the purposes of securing the economic efficiency, the proving of the reliability of nuclear merchant ships, and the establishment of safety. As the home port for Mutsu, the new port will be constructed on the open sea side in Aomori Prefecture, and as a candidate, Sekine beach in Mutsu City was named. Till the completion of the new home port, Mutsu will be berthed in Ominato home port. The conditions for entering and berthing in Ominato port will be decided later. (Kako, I.)

  16. Generalized molybdenum oxide surface chemical state XPS determination via informed amorphous sample model

    Energy Technology Data Exchange (ETDEWEB)

    Baltrusaitis, Jonas, E-mail: job314@lehigh.edu [Department of Chemical Engineering, Lehigh University, B336 Iacocca Hall, 111 Research Drive, Bethlehem, PA 18015 (United States); PhotoCatalytic Synthesis group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Meander 229, P.O. Box 217, 7500 AE Enschede (Netherlands); Mendoza-Sanchez, Beatriz [CRANN, Chemistry School, Trinity College Dublin, Dublin (Ireland); Fernandez, Vincent [Institut des Matériaux Jean Rouxel, 2 rue de la Houssinière, BP 32229, F-44322 Nantes Cedex 3 (France); Veenstra, Rick [PhotoCatalytic Synthesis group, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Meander 229, P.O. Box 217, 7500 AE Enschede (Netherlands); Dukstiene, Nijole [Department of Physical and Inorganic Chemistry, Kaunas University of Technology, Radvilenu pl. 19, LT-50254 Kaunas (Lithuania); Roberts, Adam [Kratos Analytical Ltd, Trafford Wharf Road, Wharfside, Manchester, M17 1GP (United Kingdom); Fairley, Neal [Casa Software Ltd, Bay House, 5 Grosvenor Terrace, Teignmouth, Devon TQ14 8NE (United Kingdom)

    2015-01-30

    Highlights: • We analyzed and modeled spectral envelopes of complex molybdenum oxides. • Molybdenum oxide films of varying valence and crystallinity were synthesized. • MoO{sub 3} and MoO{sub 2} line shapes from experimental data were created. • Informed amorphous sample model (IASM) developed. • Amorphous molybdenum oxide XPS envelopes were interpreted. - Abstract: Accurate elemental oxidation state determination for the outer surface of a complex material is of crucial importance in many science and engineering disciplines, including chemistry, fundamental and applied surface science, catalysis, semiconductors and many others. X-ray photoelectron spectroscopy (XPS) is the primary tool used for this purpose. The spectral data obtained, however, is often very complex and can be subject to incorrect interpretation. Unlike traditional XPS spectra fitting procedures using purely synthetic spectral components, here we develop and present an XPS data processing method based on vector analysis that allows creating XPS spectral components by incorporating key information, obtained experimentally. XPS spectral data, obtained from series of molybdenum oxide samples with varying oxidation states and degree of crystallinity, were processed using this method and the corresponding oxidation states present, as well as their relative distribution was elucidated. It was shown that monitoring the evolution of the chemistry and crystal structure of a molybdenum oxide sample due to an invasive X-ray probe could be used to infer solutions to complex spectral envelopes.

  17. Oxidatively generated DNA/RNA damage in psychological stress states

    DEFF Research Database (Denmark)

    Jørgensen, Anders

    2013-01-01

    age-related somatic disorders. The overall aim of the PhD project was to investigate the relation between psychopathology, psychological stress, stress hormone secretion and oxidatively generated DNA and RNA damage, as measured by the urinary excretion of markers of whole-body DNA/RNA oxidation (8...... between the 24 h urinary cortisol excretion and the excretion of 8-oxodG/8-oxoGuo, determined in the same samples. Collectively, the studies could not confirm an association between psychological stress and oxidative stress on nucleic acids. Systemic oxidatively generated DNA/RNA damage was increased......Both non-pathological psychological stress states and mental disorders are associated with molecular, cellular and epidemiological signs of accelerated aging. Oxidative stress on nucleic acids is a critical component of cellular and organismal aging, and a suggested pathogenic mechanism in several...

  18. Charge state of oxide layer of SIMOX-structures

    CERN Document Server

    Askinazi, A Y; Dmitriev, V A; Miloglyadova, L V

    2001-01-01

    The charge state of the oxide layer of the SIMOX-structures, obtained in the course of forming the oxide layers, bricked up in the silicon volume, through the oxygen ions implantation into the Si, is studied. The charge state of the given structures is studied through the method of the layer-by-layer profiling, which makes it possible to obtain the dependence of the plane zones potential on the oxide layer thickness. It is established, that during the process of the SIMOX-structures formation in the oxide layer near the boundary with the Si there appear defects, responsible for the charge. The radiation from the near-the-ultraviolet (NUV) area without the applied electric field neutralizes the given charge. The simultaneous impact of the NUV-radiation and electric field leads to the formation of significantly positive charge

  19. Effect of microorganisms on the plutonium oxidation states

    International Nuclear Information System (INIS)

    Lukšienė, Benedikta; Druteikienė, Rūta; Pečiulytė, Dalia; Baltrūnas, Dalis; Remeikis, Vidmantas; Paškevičius, Algimantas

    2012-01-01

    Particular microbes from substrates at the low-level radioactive waste repository in the Ignalina NPP territory were exposed to 239 Pu (IV) at low pH under aerobic conditions. Pu(III) and Pu(IV) were separated and quantitatively evaluated using the modified anion exchange method and alpha spectrometry. Tested bacteria Bacillus mycoides and Serratia marcescens were more effective in Pu reduction than Rhodococcus fascians. Fungi Paecillomyces lilacinus and Absidia spinosa var. spinosa as well as bacterium Rhodococcus fascians did not alter the plutonium oxidation state. - Highlights: ► Particular microbes from low-level radioactive waste repository were exposed to Pu (IV). ► Some tested bacteria induced slight Pu (IV) reduction at low pH under aerobic conditions. ► Tested fungi did not show peculiarities to alter Pu oxidation state. ► The modified radiochemical method was applied to differentiate Pu oxidation states.

  20. Effect of microorganisms on the plutonium oxidation states

    Energy Technology Data Exchange (ETDEWEB)

    Luksiene, Benedikta, E-mail: bena@ar.fi.lt [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Druteikiene, Ruta [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Peciulyte, Dalia [Nature Research Centre, Akademijos street 2, LT-08412 Vilnius (Lithuania); Baltrunas, Dalis; Remeikis, Vidmantas [Center for Physical Sciences and Technology, Savanoriu ave 231, LT-02300 Vilnius (Lithuania); Paskevicius, Algimantas [Nature Research Centre, Akademijos street 2, LT-08412 Vilnius (Lithuania)

    2012-03-15

    Particular microbes from substrates at the low-level radioactive waste repository in the Ignalina NPP territory were exposed to {sup 239}Pu (IV) at low pH under aerobic conditions. Pu(III) and Pu(IV) were separated and quantitatively evaluated using the modified anion exchange method and alpha spectrometry. Tested bacteria Bacillus mycoides and Serratia marcescens were more effective in Pu reduction than Rhodococcus fascians. Fungi Paecillomyces lilacinus and Absidia spinosa var. spinosa as well as bacterium Rhodococcus fascians did not alter the plutonium oxidation state. - Highlights: Black-Right-Pointing-Pointer Particular microbes from low-level radioactive waste repository were exposed to Pu (IV). Black-Right-Pointing-Pointer Some tested bacteria induced slight Pu (IV) reduction at low pH under aerobic conditions. Black-Right-Pointing-Pointer Tested fungi did not show peculiarities to alter Pu oxidation state. Black-Right-Pointing-Pointer The modified radiochemical method was applied to differentiate Pu oxidation states.

  1. Present state of electric power business in United States and Europe

    International Nuclear Information System (INIS)

    Onishi, Kenichi

    2011-01-01

    This article reported present state of nuclear power and electric power business in United States and Europe after Fukushima Daiichi Accident. As for the trend of demand and supply of electric power and policy, the accident forced Germany possibly to proceed with phase-out of nuclear power, but France and United States to sustain nuclear power with no great change of energy policy at this moment. As for the trend of electric power market, there was not state in United States with liberalized retail market of electric power after rolling blackouts occurred in California State in the early 2000s. In Germany proceeding with renewable energy introduction, renewable electricity fed into the grid was paid for by the network operators at fixed tariffs and the costs passed on to electricity consumers were increasing. Renewable Portfolio Standards (RPS) in United States forced the state to introduction of renewable energy to some ratio, and Feed-in Tariff (FIT) introduced in EU in 1990s lead to introduction of a large amount of renewable electricity targeted in 2020. Huge amount of wind power introduction brought about several problems to solve such that excess electric power above domestic demand had bad effects on grids in neighboring region. Enforcement of power transmission lines was also needed with increase of maximum electric power as well as introduction of a large amount of renewable electricity. (T. Tanaka)

  2. The Present State of Children's Literature in Indigenous African

    African Journals Online (AJOL)

    USER

    This work tries to explore the state of children's indigenous literature at both nursery .... short of that is interpreted as illiteracy and a credit pass in the foreign language is an ... Igbos have summarized their scorn of what Igbo stands for by coining the word ... The notable exception was Mazi Mbonu Ojike of blessed memory.

  3. On Present State of Teaching Russian Language in Russia

    Science.gov (United States)

    Tekucheva, Irina V.; Gromova, Liliya Y.

    2016-01-01

    The article discusses the current state of teaching Russian language, discovers the nature of philological education, outlines the main problems of the implementation of the standard in school practice, analyzes the problems of formation of universal educational actions within the context of the implementation of cognitive-communicative approach,…

  4. The Present and Future State of Blended Learning in Workplace Learning Settings in the United States

    Science.gov (United States)

    Bonk, Curtis J.; Kim, Kyong-Jee; Oh, Eun Jung; Teng, Ya-Ting; Son, Su Jin

    2007-01-01

    This paper reports survey findings related to the present and future state of blended learning in workplace learning settings across the U.S. Surveyed in this study are 118 practitioners in corporate training or elearning in various workplace settings. The findings reveal interesting perceptions by respondents regarding the benefits of and…

  5. Organic radiation chemistry--the present state and problems

    International Nuclear Information System (INIS)

    Sareava, V.V.; Kalyazin, E.P.

    1985-01-01

    The authors pose the principal problems to be solved in organic radiation chemistry: 1) to derive from the structural formula of a given organic compound the composition of the products from its radiolysis under standard conditions; 2) to use a number of physicochemical properties of a given compound at the molecular and material levels to predict the variation in composition and fraction of products from the radiolysis of the compounds with a change in irradiation conditions, i.e., the parameters of the acting radiation and the state of the substance, to indicate the direction of the principal radiation chemical processes in complex mixtures of natural or technical origin. Having stated the problems, the authors attempt to show the level of understanding of the radiolysis of organic compounds, using aliphatic hydrocarbons as principal discussion subjects

  6. Shifts in oxidation states of cerium oxide nanoparticles detected inside intact hydrated cells and organelles

    Energy Technology Data Exchange (ETDEWEB)

    Szymanski, Craig J.; Munusamy, Prabhakaran; Mihai, Cosmin; Xie, Yumei; Hu, Dehong; Gilles, Marry K.; Tyliszczak, T.; Thevuthasan, Suntharampillai; Baer, Donald R.; Orr, Galya

    2015-09-01

    Cerium oxide nanoparticles (CNPs) have been shown to induce diverse biological effects, ranging from toxic to beneficial. The beneficial effects have been attributed to the potential antioxidant activity of CNPs via certain redox reactions, depending on their oxidation state or Ce3+/Ce4+ ratio. However, this ratio is strongly dependent on the environment and age of the nanoparticles and it is unclear whether and how the complex intracellular environment impacts this ratio and the possible redox reactions of CNPs. To identify any changes in the oxidation state of CNPs in the intracellular environment and better understand their intracellular reactions, we directly quantified the oxidation states of CNPs outside and inside intact hydrated cells and organelles using correlated scanning transmission x-ray and super resolution fluorescence microscopies. By analyzing hundreds of small CNP aggregates, we detected a shift to a higher Ce3+/Ce4+ ratio in CNPs inside versus outside the cells, indicating a net reduction of CNPs in the intracellular environment. We further found a similar ratio in the cytoplasm and in the lysosomes, indicating that the net reduction occurs earlier in the internalization pathway. Together with oxidative stress and toxicity measurements, our observations identify a net reduction of CNPs in the intracellular environment, which is consistent with their involvement in potentially beneficial oxidation reactions, but also point to interactions that can negatively impact the health of cells.

  7. Presentation

    Directory of Open Access Journals (Sweden)

    Eduardo Vicente

    2013-06-01

    effectivities more than a number of fixed essential characteristics. Luiz Artur Ferrareto (UFRGS, undertaking a theoretical proposal for categorizing radio content in four different levels of planning (segment, form, programming and content itself tries to “compare and contrast the practices of Brazilian commercial broadcasting companies to those used on the radio in the United States, a reference market for our national entrepreneurs”. Madalena Oliveira (University of Minho focuses on the current stage of communication researches in Portugal reflecting on the challenges for studying a culture based on listening in times of looking. Marko Ala-Fossi, (University of Tampere beginning with the statement that “radio evolution greatly depends not only on the cultural context of a country but also on the whole social, political, economic development of societies” gives us a projection on radio development around the world for the next decades. Closing the dossier, Rafael Duarte Oliveira Venancio (UFU assuming radio as language by definition and not as a device understands it as a section and an operating model in such language as it intersects the world. Another six articles, not enrolled in the dossier, round the edition off. Fernando de Tacca debates the category of “photocine” recurring to three recent Spanish productions. Gustavo Souza investigates the possibility of identifying a point of view in documentary movies while establishing a debate that joins the materialities of image and sound with the subjectivity resulting from interpretation. Vinicius Bandeira develops on the special duplicity present in the movies between what is and what is not subsumed by the camera. Neide Jallageas proposes the study of visual communication design from the first modelings, attempting especially to the radical propositions from the early XXth century avant-garde movement. Gilson Schwartz debates on the impact from the distribution of videogames as hegemonic cultural practice in

  8. Present and Future of the United States-Bolivia Relations

    Science.gov (United States)

    2009-12-11

    Bolivariana para las Americas (Spanish for Bolivarian Alternative for the Americas) ALC Acuerdo de Libre Comercio (Spanish for Free Trade Agreement) ATPA...Challenge Account) DEA Drug Enforcement Agency FELCN Fuerza Especial de Lucha Contra el Narcotráfico (Spanish for Special Force to Combat Drug...Organizacion de Estados Americanos (Spanish for Organization of American States) PNUD United Nations Program for Development) TCP Tratado de Comercio de

  9. A Rare Manifestation of Tuberculosis Presenting in the United States

    Directory of Open Access Journals (Sweden)

    Osman Bhatty

    2016-01-01

    Full Text Available A 64-year-old Bangladeshi female presented to her primary care physician with a tender right breast lump that had been present for 4-5 days along with subjective fevers and malaise. Initial biopsy revealed granulomas, but Ziehl-Neelsen and Gram stain were negative for TB so antibiotics were prescribed for abscess until culture came positive for tuberculosis. She was started on triple therapy for extrapulmonary tuberculosis, an exceedingly rare presentation that requires high clinical suspicion in the Western world.

  10. Relationships among oxidation-reduction and acid-base properties of the actinides in high oxidation states

    International Nuclear Information System (INIS)

    Morss, L.R.

    1992-01-01

    The first chemical identification of plutonium, its subsequent isolation on the macroscopic scale, and more recent chemical separation schemes were achieved by taking advantage of the differences among the oxidation states of uranium, neptunium, and plutonium. Many acid-base properties modify the relative stabilities of oxidation states of the actinides. In the solid state, strongly basic compounds such as Cs 2 O yield complex oxides with oxidation states of Np(VII), Pu(VI), and Am(VI) whereas more acidic compounds such as CsF yield complex fluorides with lower oxidation states. In aqueous solution, high basicity and strongly covalent complexes favor high oxidation states. In nonaqueous solvent systems, high acidity generally favors low oxidation states. This paper elucidates and attempts to interpret the effects of these acid-base properties in a systematic fashion

  11. Present state of production of CAMAC system apparatus in Poland

    International Nuclear Information System (INIS)

    Dec, A.

    1978-01-01

    The production of CAMAC apparatus such as power supplies, digital and analog blocks, Moessbauer and neutron spectrometers are described. The didactic laboratory for polytechnics and universities is presented too. (A.S.)

  12. Present state of the theory of a MHD-dynamo

    Energy Technology Data Exchange (ETDEWEB)

    Soward, A M; Roberts, P H

    1976-01-01

    A review is given of the state of the theory of a MHD-dynamo, that is, the theory of self-excited magnetic fields in homogeneous moving liquids. A description is given of two basic approaches-the turbulent dynamos of Steinbeck, Krause and Redler and the high-conductivity dynamo of Braginski, and a look is also taken at the relation between these dynamos. Finally a look is taken at the results of recent studies of the total problem of a MHD-dynamo, that is, at the results of recent attempts to solve the electro- and hydrodynamic equations and to obtain self-excited fields. 6 figs., 122 ref. (SJR)

  13. Present state in coal preparation. Stanje u pripremi uglja

    Energy Technology Data Exchange (ETDEWEB)

    Jevremovic, C. (Rudarsko-Geoloski Fakultet, Tuzla (Yugoslavia))

    1990-01-01

    Describes the low technological state of Yugoslav coal enterprises,in particular of those that exploit low grade lignite and brown coal with high ash and sulfur content. Unadjusted coal prices (almost the same price level for low and high energy coal) and absence of stringent laws on environmental pollution are regarded as main reasons for the low technological level of coal preparation and beneficiation plants. Modern preparation equipment for coal classification, coal washing, coal drying and briquetting is pointed out. Advanced coal carbonization and gasification should have a wider application in Yugoslavia for reducing environmental pollution and producing clean fuel.

  14. Presentations

    International Nuclear Information System (INIS)

    2007-01-01

    The presented materials consist of presentations of international workshop which held in Warsaw from 4 to 5 October 2007. Main subject of the meeting was progress in manufacturing as well as research program development for neutron detector which is planned to be placed at GANIL laboratory and will be used in nuclear spectroscopy research

  15. Hypochlorous acid-mediated oxidation of lipid components and antioxidants present in low-density lipoproteins

    DEFF Research Database (Denmark)

    Pattison, David I; Hawkins, Clare Louise; Davies, Michael Jonathan

    2003-01-01

    Oxidation of low-density lipoproteins (LDL) is believed to contribute to the increased uptake of LDL by macrophages, which is an early event in atherosclerosis. Hypochlorous acid (HOCl) has been implicated as one of the major oxidants involved in these processes. In a previous study, the rates...... of reaction of HOCl with the reactive sites in proteins were investigated (Pattison, D. I., and Davies, M. J. (2001) Chem. Res. Toxicol. 14, 1453-1464). The work presented here expands on those studies to determine absolute second-order rate constants for the reactions of HOCl with various lipid components...... nitrogen- and carbon-centered radicals. Subsequent reactions of these species may induce oxidation of the LDL lipid component. In contrast, phosphoryl-choline reacted much more slowly (k Reaction of HOCl with 3-pentenoic acid was used as a model of lipid double bonds...

  16. The present state and future directions of PDF methods

    Science.gov (United States)

    Pope, S. B.

    1992-01-01

    The objectives of the workshop are presented in viewgraph format, as is this entire article. The objectives are to discuss the present status and the future direction of various levels of engineering turbulence modeling related to Computational Fluid Dynamics (CFD) computations for propulsion; to assure that combustion is an essential part of propulsion; and to discuss Probability Density Function (PDF) methods for turbulent combustion. Essential to the integration of turbulent combustion models is the development of turbulent model, chemical kinetics, and numerical method. Some turbulent combustion models typically used in industry are the k-epsilon turbulent model, the equilibrium/mixing limited combustion, and the finite volume codes.

  17. Trends in Process Analytical Technology: Present State in Bioprocessing.

    Science.gov (United States)

    Jenzsch, Marco; Bell, Christian; Buziol, Stefan; Kepert, Felix; Wegele, Harald; Hakemeyer, Christian

    2017-08-04

    Process analytical technology (PAT), the regulatory initiative for incorporating quality in pharmaceutical manufacturing, is an area of intense research and interest. If PAT is effectively applied to bioprocesses, this can increase process understanding and control, and mitigate the risk from substandard drug products to both manufacturer and patient. To optimize the benefits of PAT, the entire PAT framework must be considered and each elements of PAT must be carefully selected, including sensor and analytical technology, data analysis techniques, control strategies and algorithms, and process optimization routines. This chapter discusses the current state of PAT in the biopharmaceutical industry, including several case studies demonstrating the degree of maturity of various PAT tools. Graphical Abstract Hierarchy of QbD components.

  18. State of the art in crystal oscillators - Present and future

    Science.gov (United States)

    Rosati, V. J.; Filler, R. L.; Schodowski, S. S.; Vig, J. R.

    It is pointed out that most military communication, navigation, surveillance and IFF systems which are currently under development require stable oscillators for frequency control and/or timing. Examples of such systems are the Single Channel Ground and Airborne Radio System (SINCGARS), MILSTAR, the Global Positioning System (GPS), the Combat Identification System (CIS), and several radar systems. In 1981, a survey and evaluation program was initiated with the aim to determine the state-of-the-art of both TCXOs (temperature compensated crystal oscillators) and OCXOs (oven controlled crystal oscillators). This program is continuing. The results obtained to date are considered because they can provide useful guidance to system users on the availability of stable oscillators.

  19. Micropropagation of bulbous crops: technology and present state

    NARCIS (Netherlands)

    Klerk, de G.J.M.

    2012-01-01

    Conventional propagation of bulbous crops must be supplemented with micropropagation to satisfy the requirements of present-day horticulture with respect to fast production of disease-free, superior starting material. Adequate micropropagation protocols for bulbous crops are therefore a sine qua

  20. On the Present State of Information Society Studies.

    Science.gov (United States)

    Duff, Alistair S.

    2001-01-01

    Assesses the present condition of the emerging specialism of information society studies. Topics include the information economy; information technology; the information explosion; the Japanese version of information society; information society as social democracy; sociology and information science; scholarly journals; and the need for…

  1. PRESENT STATE AND THE PERSPECTIVES OF SMS MARKETING IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Mihai COSTEA

    2014-06-01

    Full Text Available The SMS (Short Message Service,which emerged at the beginning of the 90s as a result of the telephone services’ need for diversification, it is now used in the communication campaigns involving customized messaging, but also in general messaging campaigns sent both to the existing clients and to the potential ones. Thus, the SMS became widely used, turning into one of the most popular instruments of Mobile marketing and, soon becoming a separate concept named the SMS Marketing. Although there is the preconception that the mobile marketing and, namely, the SMS marketing is intended to be used primarily by the big corporations, which have the power and also the availability to invest substantial amounts of money in this sort of programs, the present paper intends precisely to debunk these preconceptions and, hence, to present the advantage of such marketing campaigns for the segment consisting of small and middle companies in Romania.

  2. Present state of the I-131-MIBG therapy

    International Nuclear Information System (INIS)

    Fischer, M.

    1986-01-01

    Treatment of malignant pheochromocytoma and neuroblastoma stage III and IV is unsatisfactory. Locally invasive tumors may be cured by radical extirpation. The role of irradiation and/or chemotherapy in malignant pheochromocytoma is disappointing, in neuroblastoma in many cases debatable. From 1981 to the present we studied more than 250 patients by MIBG scintigraphy. 5 patients with malignant pheochromocytoma, one female patient with an intra-adrenal, probably benign pheochromocytoma and 3 children with neuroblastoma stage IV were treated with I-131-MIBG

  3. Current State of the Voluntary Renewable Energy Market (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, J.

    2013-09-01

    This presentation highlights the status of the voluntary green power market in 2012. The voluntary green power market totaled more than 48 million MWh in 2012, with about 1.9 million customers participating. The supply continues to be dominated by wind, though solar is increasing its share of utility green pricing programs. Prices for voluntary renewable energy certificates (RECs) increased to above $1/MWh.

  4. Present state and perspectives of variable renewable energies in Spain

    Science.gov (United States)

    Gómez-Calvet, Roberto; Martínez-Duart, José Manuel; Serrano Calle, Silvia

    2018-03-01

    In accordance with the Paris Climate Agreement (2015) and the more recent European Union Winter Package of November 2016, the European nations have committed to drastically cut CO2 emissions during the next decades, especially in the power sector. To this end, Spain as well as many other European countries are initiating plans for a large deployment of variable renewable energy sources (VRES), especially motivated by the huge lowering in prices of solar and wind installations. In the first part of this work, a detailed analysis of the current Spanish electricity mix is carried out, especially of the present generation by VRES. To this end, we present hourly and daily fan charts, for the different days of the week as well as months or seasons of the year. These studies show that the current power system is quite varied and presents a large installed capacity in relation to peak demand. Other aspects, that will surely assist the transition to lower emission targets are the following: the recent adjudication of 9000MW of VRES, which will be operational within the next 2-3 years; a large overcapacity of Combined Cycle Gas Turbines (CCGT) plants, which could be used during the transition as backup plants; and the relatively large hydro-pump potential for the storage of possible VRES surpluses. Finally, the possibility of decommissioning several nuclear plants in a few years is also discussed.

  5. Continuum damage mechanics: Present state and future trends

    International Nuclear Information System (INIS)

    Chaboche, J.L.

    1987-01-01

    Continuum Damage Mechanics (CDM) has developed since the initial works of Kachanov and Rabotnov. The paper gives a review of its main features, of the present possibilities and of further developments. Several aspects are considered successively: damage definitions and measures, damage growth equations and anisotropy effects, and use of CDM for local approaches of fracture. Various materials, loading conditions and damaging processes are incorporated in the same general framework. Particular attention is given to the possible connections between different definitions of damage, especially between the CDM definition and the information obtained from material science. (orig.)

  6. Myofibrillar myopathies: State of the art, present and future challenges.

    Science.gov (United States)

    Béhin, A; Salort-Campana, E; Wahbi, K; Richard, P; Carlier, R-Y; Carlier, P; Laforêt, P; Stojkovic, T; Maisonobe, T; Verschueren, A; Franques, J; Attarian, S; Maues de Paula, A; Figarella-Branger, D; Bécane, H-M; Nelson, I; Duboc, D; Bonne, G; Vicart, P; Udd, B; Romero, N; Pouget, J; Eymard, B

    2015-10-01

    Myofibrillar myopathies (MFM) have been described in the mid-1990s as a group of diseases sharing common histological features, including an abnormal accumulation of intrasarcoplasmic proteins, the presence of vacuoles and a disorganization of the intermyofibrillar network beginning at the Z-disk. The boundaries of this concept are still uncertain, and whereas six genes (DES, CRYAB, LDB3/ZASP, MYOT, FLNC and BAG3) are now classically considered as responsible for MFM, other entities such as FHL1 myopathy or Hereditary Myopathy with Early Respiratory Failure linked to mutations of titin can now as well be included in this group. The diagnosis of MFM is not always easy; as histological lesions can be focal, and muscle biopsy may be disappointing; this has led to a growing importance of muscle imaging, and the selectivity of muscle involvement has now been described in several disorders. Due to the rarity of these myopathies, if some clinical patterns (such as distal myopathy associated with cardiomyopathy due to desmin mutations) are now well known, surprises remain possible and should lead to systematic testing of the known genes in case of a typical histological presentation. In this paper, we aim at reviewing the data acquired on the six main genes listed above as well as presenting the experience from two French reference centres, Paris and Marseilles. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  7. A review of smart homes- present state and future challenges.

    Science.gov (United States)

    Chan, Marie; Estève, Daniel; Escriba, Christophe; Campo, Eric

    2008-07-01

    In the era of information technology, the elderly and disabled can be monitored with numerous intelligent devices. Sensors can be implanted into their home for continuous mobility assistance and non-obtrusive disease prevention. Modern sensor-embedded houses, or smart houses, cannot only assist people with reduced physical functions but help resolve the social isolation they face. They are capable of providing assistance without limiting or disturbing the resident's daily routine, giving him or her greater comfort, pleasure, and well-being. This article presents an international selection of leading smart home projects, as well as the associated technologies of wearable/implantable monitoring systems and assistive robotics. The latter are often designed as components of the larger smart home environment. The paper will conclude by discussing future challenges of the domain.

  8. Present state of the liner of the reactor

    International Nuclear Information System (INIS)

    Aguilar H, F.; Raya A, R.; Mazon R, R.

    2001-07-01

    When being presented to work the operation personnel of the reactor, on Monday January 10, 1983, they noticed that the reactor pool was overflowing of water and the floor of the room was partially flooded. The personnel proceeded to revise the feedwater systems to the pool, the Emergency Cooling System of the core and that of Water of Reinstatement, was found that the passing valve of this last it was lightly open. It was discovered that the water that was flooded in the floor of the room it came from the relief valves of the ports TW-1 and RW-2 and of three glides that were in the Thermal Column area. It was proceeded to lower the one level of water of the pool to their normal position and it was clean the water flooded in the salts. (Author)

  9. Present state of the controversy about the grain boundary relaxation

    International Nuclear Information System (INIS)

    Povolo, F.; Molinas, B.J.

    1990-04-01

    An analysis of the internal friction produced by grain boundary relaxation in metals, alloys and ceramics is presented. The different interpretations given in the literature to relaxation phenomena occurring at temperatures above about half the melting point which include the influence of grain boundaries and their interaction with solutes and precipitates are discussed in detail. A complete set of the experimental data disposable in this field since 1972 until today is reviewed. Finally, some recent experiments are discussed and new ones are suggested. They might solve the actual controversy about the real origin of the relaxation phenomena observed. If this is the case, a considerable amount of information already published can be taken into account with a good degree of confidence. This information contributes to the description of the structure and behaviour of grain boundaries, both being important topics for materials science. (author). 119 refs, 21 figs, 1 tab

  10. MR tomography in myocardial ischaemia: present state of the art

    International Nuclear Information System (INIS)

    Szolar, D.H.; Saeed, M.; Higgins, C.B.

    1996-01-01

    Recent developments in MR imaging have opened up new avenues in the investigation of ischaemic heart disease. Conventional unenhanced spin-echo sequences have been used to detect and quantify myocardial infarction. Along with the technical advances aimed at reducing motion artifacts and imaging time, the advent of contrast media for MR imaging has further strengthened its diagnostic capacities. The applications of MR contrast media are increasing, and they are becoming more specific, to enable differentiation of occlusive and reperfused myocardial infarctions and to discriminate between reversible and irreversible myocardial injury. Previous studies have also indicated that dual administration of both relaxivity-based and susceptibility-based contrast media can be used to determine whether viable myocardium is present in the reperfused ischaemic area. Magnetic susceptibility MR contrast media have the potential to demonstrate a region of the ischaemically injured myocardium in which myocardial necrosis is present. A cornestone in the MR assessment of ischaemic heart disease has been achieved with the advent of fast MR imaging techniques. Ultrafast gradient-recalled-echo sequences or echoplanar imaging allow to monitor the first passage of the contrast medium through the heart. With the aid of MR contrast media, these techniques may be useful in estimating regional myocardial perfusion and blood volume. Experimental and clinical perfusion studies indicate that perfusion-sensitive MR imaging, particularly in concert with coronary vasodilators, can detect compromised myocardium. Combining myocardial perfusion imaging with the anatomic and functional information provided by other MR imaging techniques such as cine and velocity-encoded sequences could make MR imaging a comprehensive noninvasive diagnostic tool for the assessment of ischaemic heart disease. (orig.) [de

  11. Skin banking in the United States - past, present and future

    International Nuclear Information System (INIS)

    Greenleaf, G.

    1999-01-01

    Utilizing skin from a suicide victim to treat bums of a young boy struck by lightening, Girdner introduced skin transplantation to the United States in 1881. In the 1930's Padgett introduced the first instrument designed specifically to procure split thickness skin grafts. Padgett's dermatome allowed for reproducible recovery of large areas of fairly uniform skin grafts. This opened the way for the coverage of large wound areas. Fundamental advances in cryopreservation methodologies by the US Navy Tissue Bank in the 1950's paved the way for the preservation and storage of tissues for transplant. In the 60's and 70's the development of dedicated bum units to treat the complexity of bum injuries resulted in an increase demand for allograft skin. To supply local needs, numerous hospital based skin banks began operating throughout the US. By the early 1980's, there were approximately 50 skin banks operating in the U.S. Interestingly, as interest in transplantation of other musculoskeletal tissues increased, many tissue banks chose to focus their attention on the recovery of bone and ligaments and curtailed or eliminated skin recovery programs. Additionally, as the cost of operating tissue banks began to increase, many banks elected to consolidate their services, procure multiple tissues from each donor, and to supply these tissues to centers outside their immediate community The 1990's has revealed the emergence of M ega-Tissue Banks, as smaller, independent banks, faced with ever increasing regulations and pressure for cost containment, merged together or contracted with others for processing or distribution services. Currently, an estimated 120 musculoskeletal tissue banks operate in the U.S. Of these, less than 10 could be considered dedicated skin banks. While the number of skin banks has dwindled, the need to treat large integumental injuries remains. In the US, many biotechnology companies have recognized this need and have focused on the development of allograft

  12. Present state and perspective of research on thorium cycle

    International Nuclear Information System (INIS)

    Kimura, Itsuro

    1994-01-01

    For the prosperity of Japan and the welfare of mankind in the world, enormous quantity of energy is required in 21st century, and the general circumstances of energy and nuclear power are described. In addition to the present nuclear power using mostly 235 U and the plutonium produced from 238 U, it is the thorium cycle that 233 U produced from the third nuclear fuel, thorium, is used for electric power generation as an energy source. In this report, the 'General research on thorium cycle as a promising energy source in and after 21st century' is outlined, which has been advanced by accepting the subsidy of scientific research expense of the Ministry of Education. The features of the thorium cycle and the nuclear data and the nuclear characteristics in comparison with uranium-plutonium reactors are described. The trend of the research and development in the world and in Japan is reported. Two general researches were carried out for five years from fiscal year 1988 to 1992 on the thorium cycle. The results of the research on the nuclear data, the design of thorium reactors, the criticality experiment and analysis, thorium hybrid, thorium fuel, molten salt, fuel reprocessing and radiation safety are reported. (K.I.)

  13. Present state of the telecommunications market in Poland

    Science.gov (United States)

    Zielinski, Andrzej

    2003-10-01

    This statement shortly describes the changes in the telecommunication market that have taken place in the last 12 years, during the socio-economical transformation in Poland. It concerns economical, legal and technical problems related to the development of the telecommunications in Poland based on the principles of the market economy. Especially it is related to the commercialization of this sector, what has been a result of the changes of the principal law ruling the national economy including changes ot the telecommunication law. Changes of the law enabled the creation of the commercial company Polish Telecom and opened the way to the privatization of this company. Due to the changed law the way to the step-by-step liberalization and de-monopolization process has been also opened in Poland. It has caused fully digital modernization of telecommunication network, introduction new services such as cellular communications and Internet services, as well as rapid development of the market, what has expressed in multiplication of number of subscribers of stationary telephony, creation of the big cellular market and new increasing Internet market. The statemnet also refers to present difficulties in development of this market and as well as to the prospects for the future developments.

  14. Present state and problems of uranium fuel fabrication businesses

    International Nuclear Information System (INIS)

    Yuki, Akio

    1981-01-01

    The businesses of uranium fuel fabrication converting uranium hexafluoride to uranium dioxide powder and forming fuel assemblies are the field of most advanced industrialization among nuclear fuel cycle industries in Japan. At present, five plants of four companies engage in this business, and their yearly sales exceeded 20 billion yen. All companies are planning the augmentation of installation capacity to meet the growth of nuclear power generation. The companies of uranium fuel fabrication make the nuclear fuel of the specifications specified by reactor manufacturers as the subcontractors. In addition to initially loaded fuel, the fuel for replacement is required, therefore the demand of uranium fuel is relatively stable. As for the safety of enriched uranium flowing through the farbicating processes, the prevention of inhaling uranium powder by workers and the precaution against criticality are necessary. Also the safeguard measures are imposed so as not to convert enriched uranium to other purposes than peacefull ones. The strict quality control and many times of inspections are carried out to insure the soundness of nuclear fuel. The growth of the business of uranium fuel fabrication and the regulation of the businesses by laws are described. As the problems for the future, the reduction of fabrication cost, the promotion of research and development and others are pointed out. (Kako, I.)

  15. Presentations

    International Nuclear Information System (INIS)

    2007-01-01

    The PARIS meeting held in Cracow, Poland from 14 to 15 May 2007. The main subjects discussed during this meeting were the status of international project dedicated to gamma spectroscopy research. The scientific research program includes investigations of giant dipole resonance, probe of hot nuclei induced in heavy reactions, Jacobi shape transitions, isospin mixing and nuclear multifragmentation. The mentioned programme needs Rand D development such as new scintillations materials as lanthanum chlorides and bromides as well as new photo detection sensors as avalanche photodiodes - such subjects are also subjects of discussion. Additionally results of computerized simulations of scintillation detectors properties by means of GEANT- 4 code are presented

  16. Coronagraphy at Pic du Midi: Present state and future projects

    Science.gov (United States)

    Koechlin, L.

    2012-12-01

    The Pic du Midi coronagraph (CLIMSO) is a group of four instruments in parallel, taking images of the whole solar photosphere and low corona. It provides series of 2048*2048 pixels images taken nominally at 1 minute time intervals, all year long, weather permitting. A team of ≃q 60 persons, by groups of 2 or 3 each week, operate the instruments. Their work is programmed in collaboration with Institut de Recherches en astrophysique et planétologie (IRAP) of Observatoire Midi Pyrénées (OMP), and with Programme National Soleil Terre (PNST). The four instruments of CLIMSO (L1, C1, L2 and C2) collect images of the Sun as following: 1) L1 : photosphere in H-α (656.28 nm) ; 2) L2 : photosphere in Ca-II (393.37 nm) ; 3) C1 : prominences in H-α ; 4) C2 : prominences in He-I (1083.0 nm). The data taken are stored in fits format images and mpeg films. They are available publicly on data bases such as BASS 2000 Meudon ({http://bass2000.obspm.fr/home.php?lang=en} and BASS2000 Tarbes ({http://bass2000.bagn.obs-mip.fr/base/sun/index.php}). Several solar studies are carried in relation with these data. In addition to the raw fits images, new images will soon be sent to the data bases: they will be calibrated in solar surface emittance, expressed in W/m^2/nm/steradian. Series of mpeg films for each day are presented in superposed color layers, so as to visualize the multispectral information better. New instrumental developments are planned for the next years and already financed. They will use spectropolarimetry to measure the magnetic field and radial velocities in the photosphere and corona. The data will cover the entire solar disc and have a sample rate of one map per minute.

  17. DetOx: a program for determining anomalous scattering factors of mixed-oxidation-state species.

    Science.gov (United States)

    Sutton, Karim J; Barnett, Sarah A; Christensen, Kirsten E; Nowell, Harriott; Thompson, Amber L; Allan, David R; Cooper, Richard I

    2013-01-01

    Overlapping absorption edges will occur when an element is present in multiple oxidation states within a material. DetOx is a program for partitioning overlapping X-ray absorption spectra into contributions from individual atomic species and computing the dependence of the anomalous scattering factors on X-ray energy. It is demonstrated how these results can be used in combination with X-ray diffraction data to determine the oxidation state of ions at specific sites in a mixed-valance material, GaCl(2).

  18. Evolution of the Oxidation State of the Earth's Mantle

    Science.gov (United States)

    Danielson, L. R.; Righter, K.; Keller, L.; Christoffersen, E.; Rahman, Z.

    2015-01-01

    The oxidation state of the Earth's mantle during formation remains an unresolved question, whether it was constant throughout planetary accretion, transitioned from reduced to oxidized, or from oxidized to reduced. We investigate the stability of Fe3(+) at depth, in order to constrain processes (water, late accretion, dissociation of FeO) which may reduce or oxidize the Earth's mantle. In our previous experiments on shergottite compositions, variable fO2, T, and P less than 4 GPa, Fe3(+)/sigma Fe decreased slightly with increasing P, similar to terrestrial basalt. For oxidizing experiments less than 7GPa, Fe3(+)/sigma Fe decreased as well, but it's unclear from previous modelling whether the deeper mantle could retain significant Fe3(+). Our current experiments expand our pressure range deeper into the Earth's mantle and focus on compositions and conditions relevant to the early Earth. Preliminary multi-anvil experiments with Knippa basalt as the starting composition were conducted at 5-7 GPa and 1800 C, using a molybdenum capsule to set the fO2 near IW, by buffering with Mo-MoO3. TEM and EELS analyses revealed the run products quenched to polycrystalline phases, with the major phase pyroxene containing approximately equal to Fe3(+)/2(+). Experiments are underway to produce glassy samples that can be measured by EELS and XANES, and are conducted at higher pressures.

  19. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-10-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. Efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness and as a monitor of system corrosion effects. The discussion is based mostly on the results of observations from Ontario Hydro plants, and their comparisons with pressurized-water reactors. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of layup and various startup conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on CPT on the primary side of SGs are also discussed. (author)

  20. Corrosion-product transport, oxidation state and remedial measures

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brett, M.E.; Tapping, R.L.

    1998-01-01

    The issues associated with monitoring and controlling corrosion-product transport (CPT) in the balance-of-plant (BOP) and steam generators (SG) of CANDU stations are briefly reviewed. The efforts are focused on minimizing corrosion of carbon steel, which is used extensively in the CANDU primary and secondary systems. Emphasis is placed on the corrosion-product oxidation state as a monitor of water chemistry effectiveness, and as a monitor of system corrosion effects. The discussion is based mostly on the results and observations from Ontario Hydro plants, and their comparisons with PWRs. The effects of low oxygen and elevated hydrazine chemistry are reviewed, as well as the effects of lay-up and various start-up conditions. Progress in monitoring electrochemical potential (ECP) at Ontario Hydro plants and its relationship to the oxidation state of corrosion products is reviewed. Observations on corrosion-product transport on the primary side of steam generators are also discussed. (author)

  1. Study of uranium oxidation states in geological material.

    Science.gov (United States)

    Pidchenko, I; Salminen-Paatero, S; Rothe, J; Suksi, J

    2013-10-01

    A wet chemical method to determine uranium (U) oxidation states in geological material has been developed and tested. The problem faced in oxidation state determinations with wet chemical methods is that U redox state may change when extracted from the sample material, thereby leading to erroneous results. In order to quantify and monitor U redox behavior during the acidic extraction in the procedure, an analysis of added isotopic redox tracers, (236)U(VI) and (232)U(IV), and of variations in natural uranium isotope ratio ((234)U/(238)U) of indigenous U(IV) and U(VI) fractions was performed. Two sample materials with varying redox activity, U bearing rock and U-rich clayey lignite sediment, were used for the tests. The Fe(II)/Fe(III) redox-pair of the mineral phases was postulated as a potentially disturbing redox agent. The impact of Fe(III) on U was studied by reducing Fe(III) with ascorbic acid, which was added to the extraction solution. We observed that ascorbic acid protected most of the U from oxidation. The measured (234)U/(238)U ratio in U(IV) and U(VI) fractions in the sediment samples provided a unique tool to quantify U oxidation caused by Fe(III). Annealing (sample heating) to temperatures above 500 °C was supposed to heal ionizing radiation induced defects in the material that can disturb U redox state during extraction. Good agreement between two independent methods was obtained for DL-1a material: an average 38% of U(IV) determined by redox tracer corrected wet chemistry and 45% for XANES. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Optoelectronic properties of valence-state-controlled amorphous niobium oxide

    Science.gov (United States)

    Onozato, Takaki; Katase, Takayoshi; Yamamoto, Akira; Katayama, Shota; Matsushima, Koichi; Itagaki, Naho; Yoshida, Hisao; Ohta, Hiromichi

    2016-06-01

    In order to understand the optoelectronic properties of amorphous niobium oxide (a-NbO x ), we have investigated the valence states, local structures, electrical resistivity, and optical absorption of a-NbO x thin films with various oxygen contents. It was found that the valence states of Nb ion in a-NbO x films can be controlled from 5+  to 4+  by reducing oxygen pressure during film deposition at room temperature, together with changing the oxide-ion arrangement around Nb ion from Nb2O5-like to NbO2-like local structure. As a result, a four orders of magnitude reduction in the electrical resistivity of a-NbO x films was observed with decreasing oxygen content, due to the carrier generation caused by the appearance and increase of an oxygen-vacancy-related subgap state working as an electron donor. The tunable optoelectronic properties of a-NbO x films by valence-state-control with oxygen-vacancy formation will be useful for potential flexible optoelectronic device applications.

  3. Opto-electronic properties of bismuth oxide films presenting different crystallographic phases

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Celia L. [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, UNAM, Unidad de Posgrado, Edificio C, Piso 1, Zona Cultural de CU, México, D.F. 04510 (Mexico); Depablos-Rivera, Osmary, E-mail: osmarydep@yahoo.com [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Posgrado en Ciencia e Ingeniería de Materiales, UNAM, Unidad de Posgrado, Edificio C, Piso 1, Zona Cultural de CU, México, D.F. 04510 (Mexico); Silva-Bermudez, Phaedra [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Instituto Nacional de Rehabilitación, Calz. México Xochimilco No. 289 Col. Arenal de Guadalupe, C.P.14389, Ciudad de México, D.F. (Mexico); Muhl, Stephen [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico); Zeinert, Andreas; Lejeune, Michael; Charvet, Stephane; Barroy, Pierre [Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, 33 rue Saint Leu, 80039 Amiens Cedex 1 (France); Camps, Enrique [Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca S/N, kilómetro 36.5. La Marquesa, Municipio de Ocoyoacac, CP 52750, Estado de México (Mexico); Rodil, Sandra E. [Instituto de Investigaciones en Materiales, UNAM, Circuito Exterior s/n CU, México D.F. 04510 (Mexico)

    2015-03-02

    The optical, electrical and structural properties of bismuth oxide thin films deposited by radio frequency reactive magnetron sputtering were studied. The Bi{sub 2}O{sub 3} thin films were grown on Si and glass substrates under different power and substrate temperatures in an oxygen-enriched plasma leading to films with different crystalline phase as evidenced by X-ray diffraction and Raman spectroscopy. The optical properties of the films were measured using ellipsometric spectroscopy and optical transmission spectra. In order to parameterize the optical dispersion functions (n, k) of the films, the Tauc–Lorentz dispersion model was used. The optical bandgap was then assessed by different methods and the results are compared to the thermal variations of the electrical resistivity of the films. It was found that the refractive index, extinction coefficient and optical gap strongly depend on the deposition conditions and the crystalline phase; the fluorite defect cubic δ-Bi{sub 2}O{sub 3} phase showed the lowest optical gap and lower resistivity. - Highlights: • Different bismuth oxide phases were obtained by sputtering. • The power and substrate temperature were the two key parameters. • Room temperature delta-Bi{sub 2}O{sub 3} thin films were obtained. • The optical bandgap was around 1.5 and 2.2 eV, depending on the phase. • The bismuth oxide films presented activation energies around 1 eV.

  4. Opto-electronic properties of bismuth oxide films presenting different crystallographic phases

    International Nuclear Information System (INIS)

    Gomez, Celia L.; Depablos-Rivera, Osmary; Silva-Bermudez, Phaedra; Muhl, Stephen; Zeinert, Andreas; Lejeune, Michael; Charvet, Stephane; Barroy, Pierre; Camps, Enrique; Rodil, Sandra E.

    2015-01-01

    The optical, electrical and structural properties of bismuth oxide thin films deposited by radio frequency reactive magnetron sputtering were studied. The Bi 2 O 3 thin films were grown on Si and glass substrates under different power and substrate temperatures in an oxygen-enriched plasma leading to films with different crystalline phase as evidenced by X-ray diffraction and Raman spectroscopy. The optical properties of the films were measured using ellipsometric spectroscopy and optical transmission spectra. In order to parameterize the optical dispersion functions (n, k) of the films, the Tauc–Lorentz dispersion model was used. The optical bandgap was then assessed by different methods and the results are compared to the thermal variations of the electrical resistivity of the films. It was found that the refractive index, extinction coefficient and optical gap strongly depend on the deposition conditions and the crystalline phase; the fluorite defect cubic δ-Bi 2 O 3 phase showed the lowest optical gap and lower resistivity. - Highlights: • Different bismuth oxide phases were obtained by sputtering. • The power and substrate temperature were the two key parameters. • Room temperature delta-Bi 2 O 3 thin films were obtained. • The optical bandgap was around 1.5 and 2.2 eV, depending on the phase. • The bismuth oxide films presented activation energies around 1 eV

  5. Oxidation of extracellular cysteine/cystine redox state in bleomycin-induced lung fibrosis.

    Science.gov (United States)

    Iyer, Smita S; Ramirez, Allan M; Ritzenthaler, Jeffrey D; Torres-Gonzalez, Edilson; Roser-Page, Susanne; Mora, Ana L; Brigham, Kenneth L; Jones, Dean P; Roman, Jesse; Rojas, Mauricio

    2009-01-01

    Several lines of evidence indicate that depletion of glutathione (GSH), a critical thiol antioxidant, is associated with the pathogenesis of idiopathic pulmonary fibrosis (IPF). However, GSH synthesis depends on the amino acid cysteine (Cys), and relatively little is known about the regulation of Cys in fibrosis. Cys and its disulfide, cystine (CySS), constitute the most abundant low-molecular weight thiol/disulfide redox couple in the plasma, and the Cys/CySS redox state (E(h) Cys/CySS) is oxidized in association with age and smoking, known risk factors for IPF. Furthermore, oxidized E(h) Cys/CySS in the culture media of lung fibroblasts stimulates proliferation and expression of transitional matrix components. The present study was undertaken to determine whether bleomycin-induced lung fibrosis is associated with a decrease in Cys and/or an oxidation of the Cys/CySS redox state and to determine whether these changes were associated with changes in E(h) GSH/glutathione disulfide (GSSG). We observed distinct effects on plasma GSH and Cys redox systems during the progression of bleomycin-induced lung injury. Plasma E(h) GSH/GSSG was selectively oxidized during the proinflammatory phase, whereas oxidation of E(h) Cys/CySS occurred at the fibrotic phase. In the epithelial lining fluid, oxidation of E(h) Cys/CySS was due to decreased food intake. Thus the data show that decreased precursor availability and enhanced oxidation of Cys each contribute to the oxidation of extracellular Cys/CySS redox state in bleomycin-induced lung fibrosis.

  6. The oxidation state of sulfur in apatite: A new oxybarometer?

    Science.gov (United States)

    Fiege, A.; Konecke, B.; Kim, Y.; Simon, A. C.; Becker, U.; Parat, F.

    2016-12-01

    Oxygen fugacity (fO2) of magmatic and hydrothermal systems influences, for instance, crystallization and degassing processes as well as metal solubilities in melts and fluids. Apatite is a ubiquitous mineral in magmatic and hydrothermal environments that can record and preserve volatile zonation. It can contain several thousand μg/g of the redox sensitive element sulfur (S), making S-in-apatite a potential fO2 sensor. Despite the polyvalent properties of S (e.g., S2-, S4+, S6+), the oxidation state and incorporation mechanisms of S in the apatite structure are poorly understood. In this study, the oxidation state of S-in-apatite as a function of fO2 is investigated using X-ray absorption near-edge structures (XANES) spectroscopy at the S K-edge. Apatites crystallized from lamproitic melts at 1000°C, 300 MPa and over a broad range of fO2 and sulfur fugacities (fS2) were measured. Peaks corresponding to S6+ ( 2482 eV), S4+ ( 2478 eV) and S2- ( 2470 eV) were identified in apatite. The integrated S6+/STotal (STotal = S6+ + S4+ + S2-) peak area ratios show a distinct positive correlation with fO2, increasing from 0.17 at FMQ+0 to 0.96 at FMQ+3. Ab-initio calculations were performed to further understand the energetics and geometry of incorporation of S6+, S4+ and S2- into the apatite (F-, Cl-, OH-) end-members. The results confirm that apatite can contain three different oxidations states of S (S6+, S4+, S2-) as a function of fO2. This makes apatite probably the first geologically relevant mineral to incorporate reduced (S2-), intermediate (S4+), and oxidized (S6+) S in variable proportions. We emphasize that the strong dependence of the S oxidation state in apatite as a function of fO2 is also coupled with changing S content of apatite and co-existing melt (i.e., with changing fS2), resulting in a complex correlation between [1] apatite-melt (or fluid) partitioning, [2] redox conditions and [3] the melt and/or fluid composition, making the application of previously

  7. Conformational Toggling of Yeast Iso-1-Cytochrome c in the Oxidized and Reduced States

    Science.gov (United States)

    Yang, Zhongzheng; Zhu, Jing; Ying, Tianlei; Jiang, Xianwang; Zhang, Xu; Wu, Houming; Liu, Maili; Tan, Xiangshi; Cao, Chunyang; Huang, Zhong-Xian

    2011-01-01

    To convert cyt c into a peroxidase-like metalloenzyme, the P71H mutant was designed to introduce a distal histidine. Unexpectedly, its peroxidase activity was found even lower than that of the native, and that the axial ligation of heme iron was changed to His71/His18 in the oxidized state, while to Met80/His18 in the reduced state, characterized by UV-visible, circular dichroism, and resonance Raman spectroscopy. To further probe the functional importance of Pro71 in oxidation state dependent conformational changes occurred in cyt c, the solution structures of P71H mutant in both oxidation states were determined. The structures indicate that the half molecule of cyt c (aa 50–102) presents a kind of “zigzag riveting ruler” structure, residues at certain positions of this region such as Pro71, Lys73 can move a big distance by altering the tertiary structure while maintaining the secondary structures. This finding provides a molecular insight into conformational toggling in different oxidation states of cyt c that is principle significance to its biological functions in electron transfer and apoptosis. Structural analysis also reveals that Pro71 functions as a key hydrophobic patch in the folding of the polypeptide of the region (aa 50–102), to prevent heme pocket from the solvent. PMID:22087268

  8. Chelation and stabilization of berkelium in oxidation state +IV

    Science.gov (United States)

    Deblonde, Gauthier J.-P.; Sturzbecher-Hoehne, Manuel; Rupert, Peter B.; An, Dahlia D.; Illy, Marie-Claire; Ralston, Corie Y.; Brabec, Jiri; de Jong, Wibe A.; Strong, Roland K.; Abergel, Rebecca J.

    2017-09-01

    Berkelium (Bk) has been predicted to be the only transplutonium element able to exhibit both +III and +IV oxidation states in solution, but evidence of a stable oxidized Bk chelate has so far remained elusive. Here we describe the stabilization of the heaviest 4+ ion of the periodic table, under mild aqueous conditions, using a siderophore derivative. The resulting Bk(IV) complex exhibits luminescence via sensitization through an intramolecular antenna effect. This neutral Bk(IV) coordination compound is not sequestered by the protein siderocalin—a mammalian metal transporter—in contrast to the negatively charged species obtained with neighbouring trivalent actinides americium, curium and californium (Cf). The corresponding Cf(III)-ligand-protein ternary adduct was characterized by X-ray diffraction analysis. Combined with theoretical predictions, these data add significant insight to the field of transplutonium chemistry, and may lead to innovative Bk separation and purification processes.

  9. From Commodity to Donation: Breast Milk Banking in the United States, 1910 to the Present

    OpenAIRE

    Gerstein Pineau, Marisa

    2011-01-01

    This article presents a brief history of breast milk banking in the United States from 1910 to the present. The article discusses the the shift in both the ideology and commodification of breast milk banking in the United States.

  10. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-10-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), CIO 2 + RuF 6 - , a new compound well identified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  11. Synthesis and characterization of ruthenium fluorides and oxide fluorides with high oxidation states

    International Nuclear Information System (INIS)

    Meublat, L.

    1989-01-01

    The synthesis of ruthenium fluorides and oxide fluorides with high oxidation states was attempted from dioxide RuO 2 and tetroxide RuO 4 . Three fluorinating agents were used: fluorine, chlorine trifluoride and krypton difluoride. The reactions were achieved in anhydrous hydrogen fluoride at room temperature. Thus, the reaction of RuO 4 with CIF 3 enabled us to prepare chloryl hexafluororuthenate (V), ClO 2 + RuF 6 - , a new compound well idendified by vibrational spectroscopy (infra-red and Raman), the structure of which was determined. The reaction of KrF 2 with RuO 4 gave the oxide tetrafluoride RuOF 4 , the previously published syntheses and properties of which were not in agreement with each other. This compound was definitely characterized here by chemical analysis, infra-red spectroscopy and X-ray powder diffraction. The product of thermal decomposition (70 0 C) of RuOF 4 is presumably RuF 4 since only oxygen is liberated during this decomposition. At last, the reaction of KrF 2 with RuO 2 probably leads to the formation of the new oxide fluoride RuO 2 F 4 . Indeed, no oxygen is given off during this reaction, the chemical analysis of the red-orange coloured solid residue is almost in agreement with the one proposed and its infra-red absorption spectrum indicates the presence of ruthenium-oxygen and ruthenium-terminal and bridging fluorine bonds [fr

  12. Method of isolation of traces of americium by using the +6 oxidation state properties

    International Nuclear Information System (INIS)

    Kwinta, Jean; Michel, Jean-Jacques

    1969-05-01

    The authors present a method to separate traces of americium from a solution containing fission products and actinides. This method comprises the following steps: firstly, the oxidation of americium at the +6 state by ammonium persulfate and carrying over of actinides and III and IV lanthanides by lanthanum fluoride; secondly, the reduction by hydrazine of the oxidized americium and carrying over of the reduced americium by lutetium fluoride; and thirdly, the americium-lutetium separation by selective extractions either with di 2 ethyl hexyl phosphoric acid, or by fractionated elution on an anionic resin column by a mixture of nitric acid and methanol [fr

  13. A magnetic route to measure the average oxidation state of mixed-valent manganese in manganese oxide octahedral molecular sieves (OMS).

    Science.gov (United States)

    Shen, Xiong-Fei; Ding, Yun-Shuang; Liu, Jia; Han, Zhao-Hui; Budnick, Joseph I; Hines, William A; Suib, Steven L

    2005-05-04

    A magnetic route has been applied for measurement of the average oxidation state (AOS) of mixed-valent manganese in manganese oxide octahedral molecular sieves (OMS). The method gives AOS measurement results in good agreement with titration methods. A maximum analysis deviation error of +/-7% is obtained from 10 sample measurements. The magnetic method is able to (1) confirm the presence of mixed-valent manganese and (2) evaluate AOS and the spin states of d electrons of both single oxidation state and mixed-valent state Mn in manganese oxides. In addition, the magnetic method may be extended to (1) determine AOS of Mn in manganese oxide OMS with dopant "diamagnetic" ions, such as reducible V5+ (3d0) ions, which is inappropriate for the titration method due to interference of redox reactions between these dopant ions and titration reagents, such as KMnO4, (2) evaluate the dopant "paramagnetic" ions that are present as clusters or in the OMS framework, and (3) determine AOS of other mixed-valent/single oxidation state ion systems, such as Mo3+(3d3)-Mo4+(3d2) systems and Fe3+ in FeCl3.

  14. Proteomic indicators of oxidation and hydration state in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Jeffrey M. Dick

    2016-07-01

    Full Text Available New integrative approaches are needed to harness the potential of rapidly growing datasets of protein expression and microbial community composition in colorectal cancer. Chemical and thermodynamic models offer theoretical tools to describe populations of biomacromolecules and their relative potential for formation in different microenvironmental conditions. The average oxidation state of carbon (ZC can be calculated as an elemental ratio from the chemical formulas of proteins, and water demand per residue ( ${\\overline{n}}_{{\\mathrm{H}}_{2}\\mathrm{O}}$ n ¯ H 2 O is computed by writing the overall formation reactions of proteins from basis species. Using results reported in proteomic studies of clinical samples, many datasets exhibit higher mean ZC or ${\\overline{n}}_{{\\mathrm{H}}_{2}\\mathrm{O}}$ n ¯ H 2 O of proteins in carcinoma or adenoma compared to normal tissue. In contrast, average protein compositions in bacterial genomes often have lower ZC for bacteria enriched in fecal samples from cancer patients compared to healthy donors. In thermodynamic calculations, the potential for formation of the cancer-related proteins is energetically favored by changes in the chemical activity of H2O and fugacity of O2 that reflect the compositional differences. The compositional analysis suggests that a systematic change in chemical composition is an essential feature of cancer proteomes, and the thermodynamic descriptions show that the observed proteomic transformations in host tissue could be promoted by relatively high microenvironmental oxidation and hydration states.

  15. Composition and oxidation state of sulfur in atmospheric particulate matter

    Directory of Open Access Journals (Sweden)

    A. F. Longo

    2016-10-01

    Full Text Available The chemical and physical speciation of atmospheric sulfur was investigated in ambient aerosol samples using a combination of sulfur near-edge x-ray fluorescence spectroscopy (S-NEXFS and X-ray fluorescence (XRF microscopy. These techniques were used to determine the composition and oxidation state of sulfur in common primary emission sources and ambient particulate matter collected from the greater Atlanta area. Ambient particulate matter samples contained two oxidation states: S0 and S+VI. Ninety-five percent of the individual aerosol particles (> 1 µm analyzed contain S0. Linear combination fitting revealed that S+VI in ambient aerosol was dominated by ammonium sulfate as well as metal sulfates. The finding of metal sulfates provides further evidence for acidic reactions that solubilize metals, such as iron, during atmospheric transport. Emission sources, including biomass burning, coal fly ash, gasoline, diesel, volcanic ash, and aerosolized Atlanta soil, and the commercially available bacterium Bacillus subtilis, contained only S+VI. A commercially available Azotobacter vinelandii sample contained approximately equal proportions of S0 and S+VI. S0 in individual aerosol particles most likely originates from primary emission sources, such as aerosolized bacteria or incomplete combustion.

  16. 49 CFR 24.208 - Aliens not lawfully present in the United States.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Aliens not lawfully present in the United States... Requirements § 24.208 Aliens not lawfully present in the United States. (a) Each person seeking relocation... of an individual, that he or she is either a citizen or national of the United States, or an alien...

  17. Oxidation states of Fe and Ti in blue sapphire

    International Nuclear Information System (INIS)

    Wongrawang, P; Wongkokua, W; Monarumit, N; Thammajak, N; Wathanakul, P

    2016-01-01

    X-ray absorption near-edge spectroscopy (XANES) can be used to study the oxidation state of a dilute system such as transition metal defects in solid-state samples. In blue sapphire, Fe and Ti are defects that cause the blue color. Inter-valence charge transfer (IVCT) between Fe 2+ and Ti 4+ has been proposed to describe the optical color’s origin. However, the existence of divalent iron cations has not been thoroughly investigated. Fluorescent XANES is therefore employed to study K-edge absorptions of Fe and Ti cations in various blue sapphire samples including natural, synthetic, diffused and heat-treated sapphires. All the samples showed an Fe absorption edge at 7124 eV, corresponding to the Fe 3+ state; and Ti at 4984 eV, corresponding to Ti 4+ . From these results, we propose Fe 3+ -Ti 4+ mixed acceptor states located at 1.75 eV and 2.14 eV above the valence band of corundum, that correspond to 710 nm and 580 nm bands of UV–vis absorption spectra, to describe the cause of the color of blue sapphire. (paper)

  18. Influence of microorganisms on the oxidation state distribution of multivalent actinides under anoxic conditions

    International Nuclear Information System (INIS)

    Reed, Donald Timothy; Borkowski, Marian; Lucchini, Jean-Francois; Ams, David; Richmann, M.K.; Khaing, H.; Swanson, J.S.

    2010-01-01

    The fate and potential mobility of multivalent actinides in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium, uranium and neptunium are the near-surface multivalent contaminants of concern and are also key contaminants for the deep geologic disposal of nuclear waste. Their mobility is highly dependent on their redox distribution at their contamination source as well as along their potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity. Under anoxic conditions, indirect and direct bioreduction mechanisms exist that promote the prevalence of lower-valent species for multivalent actinides. Oxidation-state-specific biosorption is also an important consideration for long-term migration and can influence oxidation state distribution. Results of ongoing studies to explore and establish the oxidation-state specific interactions of soil bacteria (metal reducers and sulfate reducers) as well as halo-tolerant bacteria and Archaea for uranium, neptunium and plutonium will be presented. Enzymatic reduction is a key process in the bioreduction of plutonium and uranium, but co-enzymatic processes predominate in neptunium systems. Strong sorptive interactions can occur for most actinide oxidation states but are likely a factor in the stabilization of lower-valent species when more than one oxidation state can persist under anaerobic microbiologically-active conditions. These results for microbiologically active systems are interpreted in the context of their overall importance in defining the potential migration of multivalent actinides in the subsurface.

  19. A reagentless non-enzymatic hydrogen peroxide sensor presented using electrochemically reduced graphene oxide modified glassy carbon electrode

    International Nuclear Information System (INIS)

    Mutyala, Sankararao; Mathiyarasu, Jayaraman

    2016-01-01

    Herein, we report a simple, facile and reproducible non-enzymatic hydrogen peroxide (H 2 O 2 ) sensor using electrochemically reduced graphene oxide (ERGO) modified glassy carbon electrode (GCE). The modified electrode was characterized by Fourier transform infrared (FT-IR), UV–Visible, scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. Cyclic voltammetric (CV) analysis revealed that ERGO/GCE exhibited virtuous charge transfer properties for a standard redox systems and showed excellent performance towards electroreduction of H 2 O 2 . Amperometric study using ERGO/GCE showed high sensitivity (0.3 μA/μM) and faster response upon the addition of H 2 O 2 at an applied potential of − 0.25 V vs. Ag/AgCl. The detection limit is assessed to be 0.7 μM (S/N = 3) and the time to reach a stable study state current is < 3 s for a linear range of H 2 O 2 concentration (1–16 μM). In addition, the modified electrode exhibited good reproducibility and long-term stability. - Graphical abstract: We presented a reagentless non-enzymatic hydrogen peroxide sensor using electrochemically reduced graphene oxide material. - Highlights: • A facile green procedure proposed for high quality graphene synthesis using electrochemical reduction of graphene oxide • A simple, facile and reagentless non-enzymatic hydrogen peroxide sensor developed using ERGO/GCE. • ERGO/GCE exhibited high sensitivity, selectivity and finite limit of detection for H 2 O 2 sensing at low overpotential. • ERGO/GCE exhibited long term stability and good reproducibility.

  20. A reagentless non-enzymatic hydrogen peroxide sensor presented using electrochemically reduced graphene oxide modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mutyala, Sankararao; Mathiyarasu, Jayaraman, E-mail: al_mathi@yahoo.com

    2016-12-01

    Herein, we report a simple, facile and reproducible non-enzymatic hydrogen peroxide (H{sub 2}O{sub 2}) sensor using electrochemically reduced graphene oxide (ERGO) modified glassy carbon electrode (GCE). The modified electrode was characterized by Fourier transform infrared (FT-IR), UV–Visible, scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. Cyclic voltammetric (CV) analysis revealed that ERGO/GCE exhibited virtuous charge transfer properties for a standard redox systems and showed excellent performance towards electroreduction of H{sub 2}O{sub 2}. Amperometric study using ERGO/GCE showed high sensitivity (0.3 μA/μM) and faster response upon the addition of H{sub 2}O{sub 2} at an applied potential of − 0.25 V vs. Ag/AgCl. The detection limit is assessed to be 0.7 μM (S/N = 3) and the time to reach a stable study state current is < 3 s for a linear range of H{sub 2}O{sub 2} concentration (1–16 μM). In addition, the modified electrode exhibited good reproducibility and long-term stability. - Graphical abstract: We presented a reagentless non-enzymatic hydrogen peroxide sensor using electrochemically reduced graphene oxide material. - Highlights: • A facile green procedure proposed for high quality graphene synthesis using electrochemical reduction of graphene oxide • A simple, facile and reagentless non-enzymatic hydrogen peroxide sensor developed using ERGO/GCE. • ERGO/GCE exhibited high sensitivity, selectivity and finite limit of detection for H{sub 2}O{sub 2} sensing at low overpotential. • ERGO/GCE exhibited long term stability and good reproducibility.

  1. Determination of the oxidation states of metals and metalloids: An analytical review

    Science.gov (United States)

    Vodyanitskii, Yu. N.

    2013-12-01

    The hazard of many heavy metals/metalloids in the soil depends on their oxidation state. The problem of determining the oxidation state has been solved due to the use of synchrotron radiation methods with the analysis of the X-ray absorption near-edge structure (XANES). The determination of the oxidation state is of special importance for some hazardous heavy elements (arsenic, antimony, selenium, chromium, uranium, and vanadium). The mobility and hazard of each of these elements depend on its oxidation state. The mobilities are higher at lower oxidation states of As, Cr, V, and Se and at higher oxidation states of Sb and U. The determination of the oxidation state of arsenic has allowed revealing its fixation features in the rhizosphere of hydrophytes. The known oxidation states of chromium and uranium are used for the retention of these elements on geochemical barriers. Different oxidation states have been established for vanadium displacing iron in goethite. The determination of the oxidation state of manganese in the rhizosphere and the photosynthetic apparatus of plants is of special importance for agricultural chemists.

  2. The Effect of Superparamagnetic Iron Oxide Nanoparticle Surface Charge on Antigen Cross-Presentation

    Science.gov (United States)

    Mou, Yongbin; Xing, Yun; Ren, Hongyan; Cui, Zhihua; Zhang, Yu; Yu, Guangjie; Urba, Walter J.; Hu, Qingang; Hu, Hongming

    2017-01-01

    Magnetic nanoparticles (NPs) of superparamagnetic iron oxide (SPIO) have been explored for different kinds of applications in biomedicine, mechanics, and information. Here, we explored the synthetic SPIO NPs as an adjuvant on antigen cross-presentation ability by enhancing the intracellular delivery of antigens into antigen presenting cells (APCs). Particles with different chemical modifications and surface charges were used to study the mechanism of action of antigen delivery. Specifically, two types of magnetic NPs, γFe2O3/APTS (3-aminopropyltrimethoxysilane) NPs and γFe2O3/DMSA (meso-2, 3-Dimercaptosuccinic acid) NPs, with the same crystal structure, magnetic properties, and size distribution were prepared. Then, the promotion of T-cell activation via dendritic cells (DCs) was compared among different charged antigen coated NPs. Moreover, the activation of the autophagy, cytosolic delivery of the antigens, and antigen degradation mediated by the proteasome and lysosome were measured. Our results indicated that positive charged γFe2O3/APTS NPs, but not negative charged γFe2O3/DMSA NPs, enhanced the cross-presentation ability of DCs. Increased cross-presentation ability induced by γFe2O3/APTS NPs was associated with increased cytosolic antigen delivery. On the contrary, γFe2O3/DMSA NPs was associated with rapid autophagy. Overall, our results suggest that antigen delivered in cytoplasm induced by positive charged particles is beneficial for antigen cross-presentation and T-cell activation. NPs modified with different chemistries exhibit diverse biological properties and differ greatly in their adjuvant potentials. Thus, it should be carefully considered many different effects of NPs to design effective and safe adjuvants.

  3. Influence of vanadium oxidation states on the performance of V-Mg-Al mixed-oxide catalysts for the oxidative dehydrogenation of propane

    International Nuclear Information System (INIS)

    Schacht, L.; Navarrete, J.; Schacht, P.; Ramirez, M. A.

    2010-01-01

    V-Mg-Al mixed-oxide catalysts for oxidative dehydrogenation of propane were prepared by thermal decomposition of Mg-Al-layered double hydroxides with vanadium interlayer doping. The obtained catalysts were tested for the oxidative dehydrogenation of propane, obtaining good results in catalytic activity (conversion 16.55 % and selectivity 99.97 %) Results indicated that catalytic performance of these materials depends on how vanadium is integrated in the layered structure, which is determined by the Mg/Al ratio. Vanadium interlayer doping modifies the oxidation state of vanadium and consequently catalytic properties. Surface properties were studied by X-ray photoelectron spectroscopic and diffuse reflectance, UV-visible spectroscopy, and temperature programmed reduction. The analyses provided information about the oxidation state, before and after the reaction. From these results, it is suggested that selectivity to propylene and catalytic activity depend mainly of vanadium oxidation state. (Author)

  4. Influence of vanadium oxidation states on the performance of V-Mg-Al mixed-oxide catalysts for the oxidative dehydrogenation of propane

    Energy Technology Data Exchange (ETDEWEB)

    Schacht, L. [IPN, Escuela Superior de Fisica y Matematicas, Departamento de Ciencia de Materiales, Av. IPN s/n, Edificio 9, Col. Lindavista, 07738 Mexico D. F. (Mexico); Navarrete, J.; Schacht, P.; Ramirez, M. A., E-mail: pschacha@imp.m [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas No. 152, 07730 Mexico D. F. (Mexico)

    2010-07-01

    V-Mg-Al mixed-oxide catalysts for oxidative dehydrogenation of propane were prepared by thermal decomposition of Mg-Al-layered double hydroxides with vanadium interlayer doping. The obtained catalysts were tested for the oxidative dehydrogenation of propane, obtaining good results in catalytic activity (conversion 16.55 % and selectivity 99.97 %) Results indicated that catalytic performance of these materials depends on how vanadium is integrated in the layered structure, which is determined by the Mg/Al ratio. Vanadium interlayer doping modifies the oxidation state of vanadium and consequently catalytic properties. Surface properties were studied by X-ray photoelectron spectroscopic and diffuse reflectance, UV-visible spectroscopy, and temperature programmed reduction. The analyses provided information about the oxidation state, before and after the reaction. From these results, it is suggested that selectivity to propylene and catalytic activity depend mainly of vanadium oxidation state. (Author)

  5. Manganese oxidation state mediates toxicity in PC12 cells

    International Nuclear Information System (INIS)

    Reaney, S.H.; Smith, D.R.

    2005-01-01

    The role of the manganese (Mn) oxidation state on cellular Mn uptake and toxicity is not well understood. Therefore, undifferentiated PC12 cells were exposed to 0-200 μM Mn(II)-chloride or Mn(III)-pyrophosphate for 24 h, after which cellular manganese levels were measured along with measures of cell viability, function, and cytotoxicity (trypan blue exclusion, medium lactate dehydrogenase (LDH), 8-isoprostanes, cellular ATP, dopamine, serotonin, H-ferritin, transferrin receptor (TfR), Mn-superoxide dismutase (MnSOD), and copper-zinc superoxide dismutase (CuZnSOD) protein levels). Exposures to Mn(III) >10 μM produced 2- to 5-fold higher cellular manganese levels than equimolar exposures to Mn(II). Cell viability and ATP levels both decreased at the highest Mn(II) and Mn(III) exposures (150-200 μM), while Mn(III) exposures produced increases in LDH activity at lower exposures (≥50 μM) than did Mn(II) (200 μM only). Mn(II) reduced cellular dopamine levels more than Mn(III), especially at the highest exposures (50% reduced at 200 μM Mn(II)). In contrast, Mn(III) produced a >70% reduction in cellular serotonin at all exposures compared to Mn(II). Different cellular responses to Mn(II) exposures compared to Mn(III) were also observed for H-ferritin, TfR, and MnSOD protein levels. Notably, these differential effects of Mn(II) versus Mn(III) exposures on cellular toxicity could not simply be accounted for by the different cellular levels of manganese. These results suggest that the oxidation state of manganese exposures plays an important role in mediating manganese cytotoxicity

  6. Measurement of soil carbon oxidation state and oxidative ratio by 13C nuclear magnetic resonance

    Science.gov (United States)

    Hockaday, W.C.; Masiello, C.A.; Randerson, J.T.; Smernik, R.J.; Baldock, J.A.; Chadwick, O.A.; Harden, J.W.

    2009-01-01

    The oxidative ratio (OR) of the net ecosystem carbon balance is the ratio of net O2 and CO2 fluxes resulting from photosynthesis, respiration, decomposition, and other lateral and vertical carbon flows. The OR of the terrestrial biosphere must be well characterized to accurately estimate the terrestrial CO2 sink using atmospheric measurements of changing O2 and CO2 levels. To estimate the OR of the terrestrial biosphere, measurements are needed of changes in the OR of aboveground and belowground carbon pools associated with decadal timescale disturbances (e.g., land use change and fire). The OR of aboveground pools can be measured using conventional approaches including elemental analysis. However, measuring the OR of soil carbon pools is technically challenging, and few soil OR data are available. In this paper we test three solid-state nuclear magnetic resonance (NMR) techniques for measuring soil OR, all based on measurements of the closely related parameter, organic carbon oxidation state (Cox). Two of the three techniques make use of a molecular mixing model which converts NMR spectra into concentrations of a standard suite of biological molecules of known C ox. The third technique assigns Cox values to each peak in the NMR spectrum. We assess error associated with each technique using pure chemical compounds and plant biomass standards whose Cox and OR values can be directly measured by elemental analyses. The most accurate technique, direct polarization solid-state 13C NMR with the molecular mixing model, agrees with elemental analyses to ??0.036 Cox units (??0.009 OR units). Using this technique, we show a large natural variability in soil Cox and OR values. Soil Cox values have a mean of -0.26 and a range from -0.45 to 0.30, corresponding to OR values of 1.08 ?? 0.06 and a range from 0.96 to 1.22. We also estimate the OR of the carbon flux from a boreal forest fire. Analysis of soils from nearby intact soil profiles imply that soil carbon losses associated

  7. The problem of oxidation state stabilisation and some regularities of a Periodic system of the elements

    International Nuclear Information System (INIS)

    Kiselev, Yurii M; Tretyakov, Yuri D

    1999-01-01

    The general principles of the concept of oxidation state stabilisation are formulated. Problems associated with the preparation and provision of the highest valent forms of transition elements are considered. The empirical data concerning the synthesis of new compounds of rare-earth elements and d elements in unusually high oxidation states are analysed. The possibility of occurrence of the oxidation states + 9 and + 10 for some elements (for example, for iridium and platinum in tetraoxo ions) are discussed. Approaches to the realisation of these states are outlined and it is demonstrated that solid phases or matrices containing alkali metal cations are the most promising systems for the stabilisation of these high oxidation states. Selected thermodynamic features typical of metal halides and oxides and the regularities of the changes in the extreme oxidation states of d elements are considered. The bibliography includes 266 references.

  8. The Gut Microbial Metabolite Trimethylamine-N-Oxide Is Present in Human Cerebrospinal Fluid

    Directory of Open Access Journals (Sweden)

    Daniele Del Rio

    2017-09-01

    Full Text Available Trimethylamine-N-oxide (TMAO is a small organic molecule, derived from the intestinal and hepatic metabolism of dietary choline and carnitine. Although the involvement of TMAO in the framework of many chronic diseases has been recently described, no evidence on its putative role in the central nervous system has been provided. The aim of this study was to evaluate whether TMAO is present at detectable levels in human cerebrospinal fluid (CSF. CSF was collected for diagnostic purposes from 58 subjects by lumbar puncture and TMAO was quantified by using liquid chromatography coupled with multiple-reaction monitoring mass spectrometry. The molecule was detected in all samples, at concentrations ranging between 0.11 and 6.43 µmol/L. Further analysis on CSF revealed that a total of 22 subjects were affected by Alzheimer’s disease (AD, 16 were affected by non-AD related dementia, and 20 were affected by other neurological disorders. However, the stratification of TMAO levels according to the neurological diagnoses revealed no differences among the three groups. In conclusion, we provide the first evidence that TMAO can be assessed in human CSF, but the actual impact of this dietary metabolite in the patho-physiolgy of the central nervous system requires further study.

  9. Effect of particle size on iron nanoparticle oxidation state

    International Nuclear Information System (INIS)

    Lombardo, Jeffrey J.; Lysaght, Andrew C.; Goberman, Daniel G.; Chiu, Wilson K.S.

    2012-01-01

    Selecting catalyst particles is a very important part of carbon nanotube growth, although the properties of these nanoscale particles are unclear. In this article iron nanoparticles are analyzed through the use of atomic force microscopy and x-ray photoelectron spectroscopy in order to understand how the size affects the chemical composition of nanoparticles and thus their physical structure. Initially, atomic force microscopy was used to confirm the presence of iron particles, and to determine the average size of the particles. Next an analytical model was developed to estimate particle size as a function of deposition time using inputs from atomic force microscopy measurement. X-ray photoelectron spectroscopy analysis was then performed with a focus on the spectra relating to the 2p Fe electrons to study the chemical state of the particles as a function of time. It was shown that as the size of nanoparticles decreased, the oxidation state of the particles changed due to a high proportion of atoms on the surface.

  10. Understanding the Structure of High-K Gate Oxides - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Andre [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

    Hafnium Oxide (HfO2) amorphous thin films are being used as gate oxides in transistors because of their high dielectric constant (κ) over Silicon Dioxide. The present study looks to find the atomic structure of HfO2 thin films which hasn’t been done with the technique of this study. In this study, two HfO2 samples were studied. One sample was made with thermal atomic layer deposition (ALD) on top of a Chromium and Gold layer on a silicon wafer. The second sample was made with plasma ALD on top of a Chromium and Gold layer on a Silicon wafer. Both films were deposited at a thickness of 50nm. To obtain atomic structure information, Grazing Incidence X-ray diffraction (GIXRD) was carried out on the HfO2 samples. Because of this, absorption, footprint, polarization, and dead time corrections were applied to the scattering intensity data collected. The scattering curves displayed a difference in structure between the ALD processes. The plasma ALD sample showed the broad peak characteristic of an amorphous structure whereas the thermal ALD sample showed an amorphous structure with characteristics of crystalline materials. This appears to suggest that the thermal process results in a mostly amorphous material with crystallites within. Further, the scattering intensity data was used to calculate a pair distribution function (PDF) to show more atomic structure. The PDF showed atom distances in the plasma ALD sample had structure up to 10 Å, while the thermal ALD sample showed the same structure below 10 Å. This structure that shows up below 10 Å matches the bond distances of HfO2 published in literature. The PDF for the thermal ALD sample also showed peaks up to 20 Å, suggesting repeating atomic spacing outside the HfO2 molecule in the sample. This appears to suggest that there is some crystalline structure within the thermal ALD sample.

  11. Quantum confinement-induced tunable exciton states in graphene oxide.

    Science.gov (United States)

    Lee, Dongwook; Seo, Jiwon; Zhu, Xi; Lee, Jiyoul; Shin, Hyeon-Jin; Cole, Jacqueline M; Shin, Taeho; Lee, Jaichan; Lee, Hangil; Su, Haibin

    2013-01-01

    Graphene oxide has recently been considered to be a potential replacement for cadmium-based quantum dots due to its expected high fluorescence. Although previously reported, the origin of the luminescence in graphene oxide is still controversial. Here, we report the presence of core/valence excitons in graphene-based materials, a basic ingredient for optical devices, induced by quantum confinement. Electron confinement in the unreacted graphitic regions of graphene oxide was probed by high resolution X-ray absorption near edge structure spectroscopy and first-principles calculations. Using experiments and simulations, we were able to tune the core/valence exciton energy by manipulating the size of graphitic regions through the degree of oxidation. The binding energy of an exciton in highly oxidized graphene oxide is similar to that in organic electroluminescent materials. These results open the possibility of graphene oxide-based optoelectronic device technology.

  12. Oxidized Nitrogen Balance over 15 Months at Rural and Urban New York State Locations

    Science.gov (United States)

    Schwab, J. J.; Ninneman, M.; Marto, J.; Edgerton, E. S.; Blanchard, C. L.; Shaw, S. L.

    2017-12-01

    Continuous measurements of oxidized nitrogen species (NO, NO2, and HNO3), families of species (NOy, alkyl nitrates [or ANs], and peroxyacetyl nitrates [or PANs]), and particle nitrate (pNO3) were carried out for a fifteen-month period from August 2016 through October 2017 at two locations in New York State. The two sites were a rural research station at Pinnacle State Park in Addison, NY and an urban research station at Queens College in New York City. Four different chemiluminescence analyzers with various converters and denuders were employed to make these measurements. Instrumentation used for the study will be described, as well as some of the challenges created by combining data from these independent analyzers to address the oxidized nitrogen budget at the two sites. The Pinnacle State Park site often experiences quite clean air with low ppb levels of total NOy and a greater fraction of oxidized nitrogen products (NOz species). This contrasts with the urban Queens College location, which experiences stronger NOx sources. Seasonal differences in the NOx/NOy and NOz/NOy ratios, and the makeup of the NOz species, are also significant and will be explored in the presentation.

  13. Obesity induced alterations in redox homeostasis and oxidative stress are present from an early age.

    Science.gov (United States)

    Lechuga-Sancho, Alfonso M; Gallego-Andujar, David; Ruiz-Ocaña, Pablo; Visiedo, Francisco M; Saez-Benito, Ana; Schwarz, Mónica; Segundo, Carmen; Mateos, Rosa M

    2018-01-01

    Oxidative stress and inflammation have been postulated as underlying mechanisms for the development of obesity-related insulin resistance. This association however, remains elusive especially in childhood. We sought to investigate this relation by measuring oxidative stress and antioxidant response biomarkers, before and during an oral glucose tolerance test (OGTT), in different biological samples from obese children. 24 children were recruited for the study, (18 obese and 6 controls). After OGTT, the obese group was subdivided in two, according to whether or not carbohydrate metabolic impairment (Ob.IR+, Ob.IR-; respectively) was found. Different biomarkers were analyzed after fasting (T = 0) and during an OGTT (T = 60 and 120 min). Lipoperoxides were measured in plasma, erythrocytes, and urine; while advanced glycation end products were determined in plasma, and redox status (GSH/GSSG ratio) in erythrocytes. We found marked differences in the characterization of the oxidative status in urine and erythrocytes, and in the dynamics of the antioxidant response during OGTT. Specifically, Ob.IR+ children show increased oxidative stress, deficient antioxidant response and a significant imbalance in redox status, in comparison to controls and Ob.IR- children. Obese children with insulin resistance show increased levels of oxidative stress biomarkers, and a stunted antioxidant response to an OGTT leading to increased oxidative stress after a single glucose load, as detected in erythrocytes, but not in plasma. We propose erythrocytes as sensors of early and acute changes in oxidative stress associated with insulin resistance in childhood obesity. This is a pilot study, performed with a limited sample size, so data should be interpreted with caution until reproduced.

  14. Raman spectroscopic study of the oxidation state of Eu in molten LiCl-KCl

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung; Yun, Jong-Il [KAIST, Daejeon(Korea, Republic of)

    2016-10-15

    Spectroscopy can provide high reliability for the quantitative analysis of such system. The molar absorptivity of Eu(II) at 325 nm is reported as about 1645 M{sup -1}cm{sup -1}, which is too high to apply to higher concentration. A high-temperature Raman spectroscopy has been set and employed for analyzing the molecular structure and coordination complex and investigating the oxidation state of europium in molten LiCl-KCl. Europium can be present in divalent state while many other lanthanides exist in trivalent state. The thermodynamic properties of europium ions have been studied using electrochemical methods, spectroscopic methods, and EPR technique. Although there has been discrepancy of the reduced amount of europium in previous works, the majority of Eu(III) is thought to be reduced to Eu(II) in molten LiCl-KCl spontaneously at relatively low concentration (< 7.5 × 10{sup -4} M). Raman spectroscopy was employed to investigate the oxidation state of EuClx in LiCl-KCl at 500 .deg. C. The Raman scattering results suggest the majority of trivalent europium is reduced to divalent state with the composition change by vaporization. The Raman bands show highly asymmetric structure, quite different from regular octahedral structure.

  15. Oxidative Stress Is Differentially Present in Multiple Sclerosis Courses, Early Evident, and Unrelated to Treatment

    Directory of Open Access Journals (Sweden)

    Maira Gironi

    2014-01-01

    Full Text Available Background. Oxidative stress is well documented in multiple sclerosis (MS lesions, but its correspondence at peripheral level is still controversial. Objective. To evaluate peripheral oxidative stress markers in MS patients. Methods. We studied total blood levels of Coenzyme Q10 (CoQ10, oxidized and reduced forms of glutathione, malondialdehyde, reactive oxygen species (ROS, anti-oxidized-low-density lipoproteins (anti-oxLDL antibodies, and antioxidant power (PAO in 87 patients with different MS clinical phenotypes and in 77 controls. Results. CoQ10 was lower whereas anti-oxLDL antibodies titer was higher in MS patients than in controls. The benign variant of MS displayed both higher CoQ10 and higher anti-oxLDL than other MS clinical variants. Female patients had lower CoQ10 and PAO and higher ROS than male patients. Differences were greater in younger patients with shorter disease duration. Surprisingly, there was no difference for these markers between treated and untreated patients. Conclusion. We found lower antioxidant agents and higher anti-oxLDL antibodies in MS, and the highest antibody titers occurred in the benign form. We suggest that natural anti-oxLDL antibodies can be protective against MS, saving blood brain barrier integrity. Our findings also suggest that milder MS is associated with a distinct oxidative stress pattern, which may provide a useful biomarker of disease prognosis.

  16. Towards the improvement of the oxidation resistance of Nb-silicides in situ composites: A solid state diffusion approach

    International Nuclear Information System (INIS)

    Mathieu, S.; Knittel, S.; François, M.; Portebois, L.; Mathieu, S.; Vilasi, M.

    2014-01-01

    Highlights: •Local equilibrium is attained during oxidation at phase boundaries (steady state conditions). •A solid state diffusion model explains the oxidation mechanism of Nb-silicides composites. •The Nb ss fraction is not the only parameters governing the oxidation rate of Nb-silicides. •Aluminium increases the thermodynamic activity of Si in the Nb-silicides composites. •The results indicate the need to develop a Nb–Ti–Hf–Al–Cr–Si thermodynamic database. -- Abstract: The present study focuses on the oxidation mechanism of Nb-silicide composites and on the effect of the composition on the oxidation rate at 1100 °C. A theoretical approach is proposed based on experimental results and used to optimise the oxidation resistance. The growth model based on multiphase diffusion was experimentally tested and confirmed by manufacturing seven composites with different compositions. It was also found that the effect of the composition has to be evaluated at 1100 °C within a short time duration (50 h), where the oxide scale and the internal oxidation zone both grow according to parabolic kinetics

  17. United States panel presentations[Nuclear power technology in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Beyea, J [National Audubon Society, New York, NY (United States)

    1990-07-01

    Before I begin I have to make a disclaimer. That is that I am going to be talking about public perception because I think that is very important. But I do not want to give the impression that I think the public is wrong. I happen to agree with the public's perception of nuclear power, and I want to make that clear. I do not like the current generation of nuclear plants as I have made clear in many statements that I have made. On the other hand, in the long term, I feel that we have only two choices on the supply side, and that is nuclear power and solar electricity. And although I think solar electricity has the best chance, I am realistic enough to know that technologies do not always work the way I want. And so I think it is necessary to have at least some kind of nuclear option available. On the other hand, I do not think just any kind of nuclear technology will do. I want to talk to you about the conditions that I think you have to take into account when you try to design reactors that are publicly acceptable. I look at this as an insurance policy. Again, I do not want to be misquoted: I think nuclear power should be considered as an insurance policy, not as our first line of defense. Having made those disclaimers, what we need to do is set out a problem statement. The problem statement I set out is, 'How could one design and demonstrate a nuclear reactor that would regain public confidence in the United States, if one chose to do that?' By regaining confidence, I mean regaining sufficient confidence to site reactors at a number of locations. It is a pretty heavy task because the public cannot judge the technical issues. They have to judge the players by their characters and their histories, just as the way we calibrate anyone that knows things that we do not. I have three theses that I think are crucial. The first is that people do not believe in the claims of advocates, of any point of view, not just nuclear power, once the advocates have been proved wrong on

  18. Solid state solubility of copper oxides in hydroxyapatite

    Science.gov (United States)

    Zykin, Mikhail A.; Vasiliev, Alexander V.; Trusov, Lev A.; Dinnebier, Robert E.; Jansen, Martin; Kazin, Pavel E.

    2018-06-01

    Samples containing copper oxide doped hydroxyapatite with the composition Ca10(PO4)6(CuxOH1-x-δ)2, x = 0.054 - 0.582, in the mixture with CuO/Cu2O were prepared by a solid-state high-temperature treatment at varying annealing temperatures and at different partial water vapor and oxygen pressures. The crystal structures of the apatite compounds were refined using powder X-ray diffraction patterns and the content of copper ions x in the apatite was determined. Copper ions enter exclusively into the apatite trigonal channels formally substituting protons of OH-groups and the hexagonal cell parameters grow approximately linearly with x, the channel volume mostly expanding while the remaining volume of the crystal lattice changing only slightly. The equilibrium copper content in the apatite increases drastically, by almost a factor of 10 with the annealing temperature rising from 800° to 1200°C. The reduction of the water partial pressure leads to a further increase of x, while the dependence of x on the oxygen partial pressure exhibits a maximum. The observed relations are consistent with the proposed chemical reactions implying the copper introduction is followed by the release of a considerable quantity of gaseous products - water and oxygen. The analysis of interatomic distances suggests that the maximum content of copper ions in the channel cannot exceed 2/3.

  19. Stabilization of actinides and lanthanides in unusually high oxidation states

    International Nuclear Information System (INIS)

    Eller, P.G.; Penneman, R.A.

    1986-01-01

    Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO 3 or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF 5 /HF solution or Pu(VII) in Li 5 PuO 6 ). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs

  20. Oxidative stress induced on Cyprinus carpio by contaminants present in the water and sediment of Madin Reservoir.

    Science.gov (United States)

    Galar-Martinez, Marcela; Gomez-Olivan, Leobardo Manuel; Amaya-Chavez, Araceli; Razo-Estrada, Celene; Garcia-Medina, Sandra

    2010-01-01

    Madin Reservoir (MR), located in the State of Mexico, is fed mainly by the Rio Tlalnepantla. MR supplies potable water to the municipalities of Naucalpan and Atizapan, and various recreational activities take place in its vicinity, such as sailing and the fishing of diverse species including the common carp Cyprinus carpio. The purpose of this study was to determine the toxic effects of contaminants present in MR water and sediment on C. carpio. Five sampling stations were selected (those considered to have the most problems due to discharges). Water and sediment samples were taken and toxicity studies were performed, including acute toxicity (lethality) and subacute toxicity assays. The biomarkers used in the subacute assays were lipid peroxidation (LPX) and activity of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in the liver and brain of test organisms. These biomarkers were also evaluated in local carp, i.e. carp with chronic exposure in situ to reservoir contaminants. Results show that contaminants in the water and sediment of the different sampling stations induce oxidative stress, this toxicity being more evident in samples from stations near the entry point of the Rio Tlalnepantla tributary and in local carp. This may be due to high contaminant levels as well as the fact that the physicochemical characteristics of the matrices might favor their bioavailability. Thus, both the water and sediment of this reservoir are contaminated with xenobiotics hazardous to C. carpio, a species consumed by the local human population.

  1. The Behavior of the Ru-bda Water Oxidation Catalysts at Low Oxidation States.

    Science.gov (United States)

    Matheu, Roc; Ghaderian, Abolfazl; Francas, Laia; Chernev, Petko; Ertem, Mehmed; Benet-Buchholz, Jordi; Batista, Victor; Haumann, Michael; Gimbert-Suriñach, Carolina; Sala, Xavier; Llobet, Antoni

    2018-06-13

    The Ru complex [RuII(bda-κ-N2O2)(N-NH2)2], 1, (bda2- = (2,2'-bipyridine)-6,6'-dicarboxylate; N-NH2 = 4-(pyridin-4-yl)aniline) is used as a synthetic intermediate to prepare Ru-bda complexes that contain the NO+, acetonitrile (MeCN) or H2O ligands at oxidation states II and III. Complex 1 reacts with excess NO+ to form a Ru complex where the aryl amine ligands N-NH2 in 1 are transformed into diazonium salts (N-N2+ = 4-(pyridin-4-yl)benzenediazonium)) together with the formation of a new Ru-NO group at the equatorial zone, to generate [RuII(bda-κ-N2O)(NO)(N-N2)2]3+, 23+. Similarly, complex 1 can also react with a coordinating solvent, such as MeCN, at room temperature leading to complex [RuII(bda-κ-N2O)(MeCN)(N-NH2)2], 3. Finally in acidic aqueous solutions solvent water coordinates the Ru center forming {[RuII(bda-κ-(NO)3)(H2O)(N-NH3)2](H2O)n}2+, 42+, that is strongly hydrogen bonded with additional water molecules at the second coordination sphere. We have additionally characterized the one electron oxidized complex {[RuIII(bda-κ-(NO)3.5)(H2O)(N-NH3)2](H2O)n}3+, 53+. The coordination mode of the complexes has been studied both in the solid state and in solution through single-crystal XRD, X-ray absorption spectroscopy, variable-temperature NMR and DFT calculations. While the κ-N2O is the main coordination mode for 23+ and 3, an equilibrium that involves isomers with κ-N2O and κ-NO2 coordination modes and neighboring hydrogen bonded water molecules is observed for 42+ and 53+. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Quantitative chemical state XPS analysis of first row transition metals, oxides and hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, M C; Payne, B P; McIntryre, N S [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Hart, B R; Lau, L Wm [Surface Science Western, Room G1, Western Science Centre, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Grosvenor, A P [Department of Chemistry, Gunning/Lemieux Chemistry Centre, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada); Smart, R StC [ACeSSS, Applied Centre for Structural and Synchrotron Studies, University of South Australia, Mawson Lakes, SA 5095 (Australia)], E-mail: biesingr@uwo.ca

    2008-03-15

    Practical quantitative chemical state X-ray photoelectron spectroscopy (XPS) analysis of first row transition metals, oxides and hydroxides is challenging due to the complexity of their M 2p spectra. Complex multiplet splitting, shake-up and plasmon loss structure can play a role in the interpretation of the chemical states present. This paper will show practical curve fitting procedures for the quantitative measurement of different chemical states for metal oxides and hydroxides from a survey of transition metals. It will also discuss some of the limitations and pitfalls present as well as give practical examples of their successful use. These curve-fitting procedures are based on 1) standard spectra from quality reference samples, 2) a survey of appropriate literature databases and/or a compilation of literature references, 3) fitting of multiplet split spectra based on spectra of numerous reference materials and theoretical modelling, 4) spectral subtractions routines, again using reference spectra, and 5) specific literature references where fitting procedures are available.

  3. Quantitative chemical state XPS analysis of first row transition metals, oxides and hydroxides

    International Nuclear Information System (INIS)

    Biesinger, M C; Payne, B P; McIntryre, N S; Hart, B R; Lau, L Wm; Grosvenor, A P; Smart, R StC

    2008-01-01

    Practical quantitative chemical state X-ray photoelectron spectroscopy (XPS) analysis of first row transition metals, oxides and hydroxides is challenging due to the complexity of their M 2p spectra. Complex multiplet splitting, shake-up and plasmon loss structure can play a role in the interpretation of the chemical states present. This paper will show practical curve fitting procedures for the quantitative measurement of different chemical states for metal oxides and hydroxides from a survey of transition metals. It will also discuss some of the limitations and pitfalls present as well as give practical examples of their successful use. These curve-fitting procedures are based on 1) standard spectra from quality reference samples, 2) a survey of appropriate literature databases and/or a compilation of literature references, 3) fitting of multiplet split spectra based on spectra of numerous reference materials and theoretical modelling, 4) spectral subtractions routines, again using reference spectra, and 5) specific literature references where fitting procedures are available

  4. Room air versus carbon dioxide pneumoperitoneum: effects on oxidative state, apoptosis and histology of splanchnic organs.

    Science.gov (United States)

    Ypsilantis, Petros; Lambropoulou, Maria; Tentes, Ioannis; Chryssidou, Maria; Georgantas, Themistoklis; Simopoulos, Constantinos

    2016-04-01

    Although CO2 is the insufflation gas of choice in laparoscopic procedures, room air is usually used in natural orifice transluminal endoscopic surgery. The aim of the present study was to compare the safety of room air versus CO2 pneumoperitoneum in terms of their effect on the oxidative state, apoptosis and tissue injury of splanchnic organs. Eighteen Wistar rats were assigned to three groups (n = 6 per group) and were subjected to 8 mm Hg room air (group Pne-Air) or CO2 pneumoperitoneum (group Pne-CO2) or sham operation for 60 min. Forty-five minutes postdeflation, tissue samples were excised from the liver, stomach, ileum and kidneys for reduced glutathione-to-glutathione disulfide (GSH/GSSG) ratio, caspase-8 and caspase-3 and hypoxia-inducible factor-1α (HIF-1α) immunohistochemical assessment and histopathologic examination. GSH/GSSG ratio substantially declined in both pneumoperitoneum groups. No change was noted in HIF-1α expression. Mild upregulation of caspase-8 and caspase-3 was noted in both pneumoperitoneum groups being less pronounced in group Pne-Air. Histopathologic score was increased in all organs studied, but the stomach, in both pneumoperitoneum groups. Pneumoperitoneum established by either room air or CO2 induced substantial oxidative stress, mild apoptosis and mild tissue injury in splanchnic organs. While air pneumoperitoneum conferred a less pronounced apoptotic effect, the oxidative state and histopathologic profile of splanchnic organs did not differ between insufflation gases.

  5. Examination of cortisol and state anxiety at an academic setting with and without oral presentation.

    Science.gov (United States)

    Merz, Christian Josef; Wolf, Oliver Tobias

    2015-01-01

    Holding oral presentations in a university course is perceived as stressful and can increase stress hormone concentrations and state anxiety. In such a naturalistic setting, further attention should be paid to the relationship between psychological and hormonal measures of acute stress, as well as women's intake of hormonal contraceptives as a potential moderating variable. In the present study, 76 healthy students gave saliva samples before and after their oral presentations in a university course as well as on a second, control day in the same course without giving an oral presentation. Anticipatory state anxiety was rated on both days. Cortisol concentrations as well as state anxiety were substantially higher on the presentation relative to the control day. During the oral presentation, an increase in cortisol concentrations was observed, whereas a decrease occurred on the control day. Nearly the same picture emerged for both variables when looking at men, women taking hormonal contraceptives and free-cycling women separately. A positive correlation was found between the change in anticipatory state anxiety in the presentation compared to the control day and cortisol concentrations before and after the oral presentation. Concluding, oral presentations constitute a potent stressor and do not seem to be substantially different between men, free-cycling women and women taking hormonal contraceptives. Future studies may want to explore changes associated with specific menstrual cycle phases and with specific hormonal contraceptives.

  6. Regional cerebral blood flow changes related to affective speech presentation in persistent vegetative state

    NARCIS (Netherlands)

    deJong, BM; Willemsen, ATM; Paans, AMJ

    A story told by his mother was presented on tape to a trauma patient in persistent vegetative state (PVS). During auditory presentation, measurements of regional cerebral blood flow (rCBF) were performed by means of positron emission tomography (PET). Changes in rCBF related to this stimulus

  7. Oxidation under electron bombardment. A tool for studying the initial states of silicon oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Carriere, B.; Deville, J.P.; El Maachi, A.

    1987-06-01

    The exciting beam of an Auger electron spectrometer has been used to monitor the oxidation of silicon single crystals at room temperature and very low pressures of oxygen (approx. 10/sup -7/ Torr). This process allows us to build ultra-thin layers of silica on silicon (down to 30 A) but it is mostly used to investigate the mechanisms of the initial stages of oxidation. Auger spectra recorded continuously during the oxidation process provide information on (1) the nature of the silicon-oxygen chemical bonds which are interpreted through fine structure in the Auger peak, and (2) the kinetics of oxide formation which are deduced from curves of Auger signal versus time. An account is given of the contribution of these Auger studies to the description of the intermediate oxide layer during the reaction between silicon and oxygen and the influence of surface structural disorder, induced mainly by argon-ion bombardment, is discussed in terms of reactivity and oxide coverage.

  8. Interface Controlled Oxidation States in Layered Cobalt Oxide Nanoislands on Gold

    DEFF Research Database (Denmark)

    Walton, Alexander; Fester, Jakob; Bajdich, Michal

    2015-01-01

    Layered cobalt oxides have been shown to be highly active catalysts for the oxygen evolution reaction (OER; half of the catalytic “water splitting” reaction), particularly when promoted with gold. However, the surface chemistry of cobalt oxides and in particular the nature of the synergistic effect...

  9. Nanofilamentary resistive switching in binary oxide system; a review on the present status and outlook

    International Nuclear Information System (INIS)

    Kim, Kyung Min; Hwang, Cheol Seong; Jeong, Doo Seok

    2011-01-01

    This review article summarized the recent understanding of resistance switching (RS) behavior in several binary oxide thin film systems. Among the various RS materials and mechanisms, TiO 2 and NiO thin films in unipolar thermo-chemical switching mode are primarily dealt with. To facilitate the discussions, the RS was divided into three parts; electroforming, set and reset steps. After short discussions on the electrochemistry of 'electrolytic' oxide materials, the general and peculiar aspects of these RS systems and mechanism are elaborated. Although the RS behaviors and characteristics of these materials are primarily dependent on the repeated formation and rupture of the conducting filaments (CFs) at the nanoscale at a localized position, this mechanism appears to offer a basis for the understanding of other RS mechanisms which were originally considered to be irrelevant to the localized events. The electroforming and set switching phenomena were understood as the process of CF formation and rejuvenation, respectively, which are mainly driven by the thermally assisted electromigration and percolation (or even local phase transition) of defects, while the reset process was understood as the process of CF rupture where the thermal energy plays a more crucial role. This review also contains several remarks on the outlook of these resistance change devices as a semiconductor memory. (topical review)

  10. Effects of low-level exposure to xenobiotics present in paints on oxidative stress in workers.

    Science.gov (United States)

    Moro, Angela M; Charão, Mariele; Brucker, Natália; Bulcão, Rachel; Freitas, Fernando; Guerreiro, Gilian; Baierle, Marília; Nascimento, Sabrina; Waechter, Fernanda; Hirakata, Vânia; Linden, Rafael; Thiesen, Flávia V; Garcia, Solange Cristina

    2010-09-15

    Paints are composed of an extensive variety of hazardous substances, such as organic solvents and heavy metals. Biomonitoring is an essential tool for assessing the risk to occupational health. Thus, this study analyzed the levels of biomarkers of exposure for toluene, xylene, styrene, ethylbenzene, and lead, as well as the oxidative stress biomarker alterations in painters of an industry. Lipid peroxidation biomarker (MDA), delta-aminolevulinate dehydratase (ALA-D), nonprotein thyol groups, superoxide dismutase and catalase (CAT) were analyzed in exposed and nonexposed subjects. We estimated which of the paint constituents have the greatest influence on the changes in the biomarkers of oxidative stress in this case of co-exposure. The results demonstrated that despite the fact that all the biomarkers of exposure were below the biological exposure limits, the MDA levels and antioxidant enzyme activities were increased, while nonprotein thyol groups and ALA-D levels were decreased in painters when compared with nonexposed subjects. After statistic test, toluene could be suggested as the principal factor responsible for increased lipid peroxidation and inhibition of ALA-D enzyme; however, further studies on the inhibition of ALA-D enzyme by toluene are necessary. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Origin of interface states and oxide charges generated by ionizing radiation

    International Nuclear Information System (INIS)

    Sah, C.T.

    1976-01-01

    The randomly located trivalent silicon atoms are shown to account for the thermally generated interface states at the SiO 2 -Si interface. The interface state density is greatly reduced in water containing ambients at low temperatures (450 0 C) by forming trivalent silicon hydroxide bonds. Interface states are regenerated when the /triple bond/Si-OH bonds are broken by ionizing radiation and the OH ions are drifted away. In the bulk of the oxide film, the trivalent silicon and the interstitial oxygen donor centers are shown to be responsible for the heat and radiation generated positive space charge build-up (oxide charge) in thermally grown silicon oxide

  12. Towards label-free evaluation of oxidative stress in human skin exposed to sun filters (Conference Presentation)

    Science.gov (United States)

    Osseiran, Sam; Wang, Hequn; Suita, Yusuke; Roider, Elisabeth; Fisher, David E.; Evans, Conor L.

    2016-02-01

    Skin cancer, including basal cell carcinoma, squamous cell carcinoma, and melanoma, is the most common form of cancer in North America. Paradoxically, skin cancer incidence is steadily on the rise even despite the growing use of sunscreens over the past decades. One potential explanation for this discrepancy involves the sun filters in sunscreen, which are responsible for blocking harmful ultraviolet radiation. It is proposed that these agents may produce reactive oxygen species (ROS) at the site of application, thereby generating oxidative stress in skin that gives rise to genetic mutations, which may explain the rising incidence of skin cancer. To test this hypothesis, ex vivo human skin was treated with five common chemical sun filters (avobenzone, octocrylene, homosalate, octisalate, and oxybenzone) as well as two physical sun filters (zinc oxide compounds), both with and without UV irradiation. To non-invasively evaluate oxidative stress, two-photon excitation fluorescence (2PEF) and fluorescence lifetime imaging microscopy (FLIM) of the skin samples were used to monitor levels of NADH and FAD, two key cofactors in cellular redox metabolism. The relative redox state of the skin was assessed based on the fluorescence intensities and lifetimes of these endogenous cofactors. While the sun filters were indeed shown to have a protective effect from UV radiation, it was observed that they also generate oxidative stress in skin, even in the absence of UV light. These results suggest that sun filter induced ROS production requires more careful study, especially in how these reactive species impact the rise of skin cancer.

  13. Present status of reactor physics in the United States and Japan-II. 6. Present Status of GNF New Nodal Simulator

    International Nuclear Information System (INIS)

    Iwamoto, T.; Tamitani, M.; Moore, B.

    2001-01-01

    This paper presents core simulator consolidation work done at Global Nuclear Fuel (GNF). The unified simulator needs to supersede the capabilities of past simulator packages from the original GNF partners: GE (Ref. 1), Hitachi (Ref. 2), and Toshiba (Ref. 3). At the same time, an effort is being made to produce a simulation package that will be a state-of-the-art analysis tool when released, in terms of the physics solution methodology and functionality. The core simulator will be capable and qualified for (a) high-energy cycles in the U.S. markets, (b) mixed-oxide (MOX) introduction in Japan, and (c) high-power density plants in Europe, etc. The unification of the lattice physics code is also in progress based on a transport model with collision probability methods. The AETNA core simulator is built upon the PANAC11 software base. The goal is to essentially replace the 1.5-energy group model with a higher-order multigroup nonlinear nodal solution capable of the required modeling fidelity, while keeping highly automated library generation as well as functionality. All required interfaces to PANAC11 will be preserved, which minimizes the impact on users and process automation. Preliminary results show statistical accuracy improvement over the 1.5- group model. The status of the GNF new nodal simulator is presented. It is built on a highly automated software base by combining the best technologies of GE, Hitachi, and Toshiba and will provide a BWR core analysis tool with high functionality and fidelity. (authors)

  14. Determination of Model Kinetics for Forced Unsteady State Operation of Catalytic CH4 Oxidation

    Directory of Open Access Journals (Sweden)

    Effendy Mohammad

    2016-01-01

    Full Text Available The catalytic oxidation of methane for abating the emission vented from coal mine or natural gas transportation has been known as most reliable method. A reverse flow reactor operation has been widely used to oxidize this methane emission due to its capability for autothermal operation and heat production. The design of the reverse flow reactor requires a proper kinetic rate expression, which should be developed based on the operating condition. The kinetic rate obtained in the steady state condition cannot be applied for designing the reactor operated under unsteady state condition. Therefore, new approach to develop the dynamic kinetic rate expression becomes indispensable, particularly for periodic operation such as reverse flow reactor. This paper presents a novel method to develop the kinetic rate expression applied for unsteady state operation. The model reaction of the catalytic methane oxidation over Pt/-Al2O3 catalyst was used with kinetic parameter determined from laboratory experiments. The reactor used was a fixed bed, once-through operation, with a composition modulation in the feed gas. The switching time was set at 3 min by varying the feed concentration, feed flow rate, and reaction temperature. The concentrations of methane in the feed and product were measured and analysed using gas chromatography. The steady state condition for obtaining the kinetic rate expression was taken as a base case and as a way to judge its appropriateness to be applied for dynamic system. A Langmuir-Hinshelwood reaction rate model was developed. The time period during one cycle was divided into some segments, depending on the ratio of CH4/O2. The experimental result shows that there were kinetic regimes occur during one cycle: kinetic regime controlled by intrinsic surface reaction and kinetic regime controlled by external diffusion. The kinetic rate obtained in the steady state operation was not appropriate when applied for unsteady state operation

  15. Distribution, morphological variability, ecology and the present state of Nitella from Lake Ohrid and its surroundings

    Directory of Open Access Journals (Sweden)

    Trajanovska Sonja

    2012-01-01

    Full Text Available Our research into 52 profiles of the littoral zone of the Macedonian part of Lake Ohrid and numerous samples taken from its surroundings has resulted in a detailed picture of the composition of the Charophyta vegetation in the lake. The results of the research also include data regarding the species composition and present state of Nitella. The dominant species of Nitella is Nitella opaca, which is characterized by a specific distribution, morphological variability and ecology. The present state of Nitella is not steady, especially in the watershed of the lake, since in this area there are some permanent changes in the hydrology of the terrain. Therefore, there is a need to establish long-term and complex monitoring which will result in the prompt detection of risk factors and influences, thereby enabling a rapid reaction to a possible newly emerged negative state.

  16. Evaluating chemical extraction techniques for the determination of uranium oxidation state in reduced aquifer sediments

    Science.gov (United States)

    Stoliker, Deborah L.; Campbell, Kate M.; Fox, Patricia M.; Singer, David M.; Kaviani, Nazila; Carey, Minna; Peck, Nicole E.; Barger, John R.; Kent, Douglas B.; Davis, James A.

    2013-01-01

    Extraction techniques utilizing high pH and (bi)carbonate concentrations were evaluated for their efficacy in determining the oxidation state of uranium (U) in reduced sediments collected from Rifle, CO. Differences in dissolved concentrations between oxic and anoxic extractions have been proposed as a means to quantify the U(VI) and U(IV) content of sediments. An additional step was added to anoxic extractions using a strong anion exchange resin to separate dissolved U(IV) and U(VI). X-ray spectroscopy showed that U(IV) in the sediments was present as polymerized precipitates similar to uraninite and/or less ordered U(IV), referred to as non-uraninite U(IV) species associated with biomass (NUSAB). Extractions of sediment containing both uraninite and NUSAB displayed higher dissolved uranium concentrations under oxic than anoxic conditions while extractions of sediment dominated by NUSAB resulted in identical dissolved U concentrations. Dissolved U(IV) was rapidly oxidized under anoxic conditions in all experiments. Uraninite reacted minimally under anoxic conditions but thermodynamic calculations show that its propensity to oxidize is sensitive to solution chemistry and sediment mineralogy. A universal method for quantification of U(IV) and U(VI) in sediments has not yet been developed but the chemical extractions, when combined with solid-phase characterization, have a narrow range of applicability for sediments without U(VI).

  17. Towards a Predictive Thermodynamic Model of Oxidation States of Uranium Incorporated in Fe (hydr) oxides

    Energy Technology Data Exchange (ETDEWEB)

    Bagus, Paul S. [Univ. of North Texas, Denton, TX (United States)

    2013-01-01

    -Level Excited States: Consequences For X-Ray Absorption Spectroscopy”, J. Elec. Spectros. and Related Phenom., 200, 174 (2015) describes our first application of these methods. As well as applications to problems and materials of direct interest for our PNNL colleagues, we have pursued applications of fundamental theoretical significance for the analysis and interpretation of XPS and XAS spectra. These studies are important for the development of the fields of core-level spectroscopies as well as to advance our capabilities for applications of interest to our PNNL colleagues. An excellent example is our study of the surface core-level shifts, SCLS, for the surface and bulk atoms of an oxide that provides a new approach to understanding how the surface electronic of oxides differs from that in the bulk of the material. This work has the potential to lead to a new key to understanding the reactivity of oxide surfaces. Our theoretical studies use cluster models with finite numbers of atoms to describe the properties of condensed phases and crystals. This approach has allowed us to focus on the local atomistic, chemical interactions. For these clusters, we obtain orbitals and spinors through the solution of the Hartree-Fock, HF, and the fully relativistic Dirac HF equations. These orbitals are used to form configuration mixing wavefunctions which treat the many-body effects responsible for the open shell angular momentum coupling and for the satellites of the core-level spectra. Our efforts have been in two complementary directions. As well as the applications described above, we have placed major emphasis on the enhancement and extension of our theoretical and computational capabilities so that we can treat complex systems with a greater range of many-body effects. Noteworthy accomplishments in terms of method development and enhancement have included: (1) An improvement in our treatment of the large matrices that must be handled when many-body effects are treated. (2

  18. The emancipatory character of action research, its history and the present state of the art

    NARCIS (Netherlands)

    Boog, B.

    2003-01-01

    Right from the start. action research was intended to be emancipatory research, and it still is. This article will underpin this by outlining its history and the present state of the art. Though a variety of action research approaches have developed along divergent theoretical pathways, it will be

  19. Vitamin B12 deficiency presenting as an acute confusional state: A ...

    African Journals Online (AJOL)

    Results: We report a case of a 44 year old female patient referred to the haematology unit with vitamin B12 deficiency presenting as an acute confusional state or delirium. Total resolution of the psychiatric symptoms occurred following parenteral vitamin B12 replacement therapy. Conclusion: This case report highlights one ...

  20. Present status of practical aspects of individual dosimetry. Pt. 1. EC Member States

    International Nuclear Information System (INIS)

    Goeksu, H.Y.; Regulla, D.; Drexler, G.

    1995-01-01

    The study reviews the present status of radiation protection practices of occupationally exposed persons in the Member States of the European Communities by taking account of the new legislative changes. A special emphasis is given to identify and describe the difference in procedures and methods of personnel monitoring, dose assessment, record keeping and collective dose assessment in each country. (orig./HP)

  1. Ion bombardment effects on surface states in selected oxide systems: rutile and alkaline earth titanates

    International Nuclear Information System (INIS)

    Gruen, D.M.

    1978-01-01

    In this paper, the nature of the surface states of n-type TiO 2 and SrTiO 3 is discussed and the role of ion bombardment in modifying the properties of these states is elucidated. Insofar as possible, the interrelationships between oxide nonstoichiometry, surface states, ion bombardment effects and photoelectrolysis are explored

  2. Oxidation Kinetics of Copper: An Experiment in Solid State Chemistry.

    Science.gov (United States)

    Ebisuzaki, Y.; Sanborn, W. B.

    1985-01-01

    Oxidation kinetics in metals and the role defects play in diffusion-controlled reactions are discussed as background for a junior/senior-level experiment in the physical or inorganic chemistry laboratory. Procedures used and typical data obtained are provided for the experiment. (JN)

  3. Studies of surface states in zinc oxide nanopowders

    Science.gov (United States)

    Peters, Raul Mugabe

    The surface of ZnO semiconductor nanosystems is a key performance-defining factor in numerous applications. In this work we present experimental results for the surface defect-related properties of ZnO nanoscale systems. Surface photovoltage spectroscopy was used to determine the defect level energies within the band gap, the conduction vs. valence band nature of the defect-related transitions, and to probe key dynamic parameters of the surface on a number of commercially available ZnO nanopowders. In our experimental setup, surface photovoltage characterization is conducted in high vacuum in tandem with in situ oxygen remote plasma treatments. Surface photovoltage investigations of the as-received and plasma-processed samples revealed a number of common spectral features related to surface states. Furthermore, we observed significant plasma-induced changes in the surface defect properties. Ex situ positron annihilation and photoluminescence measurements were performed on the studied samples and correlated with surface photovoltage results. The average positron lifetimes were found to be substantially longer than in a bulk single crystalline sample, which is consistent with the model of grains with defect-rich surface and subsurface layers. Compression of the powders into pellets yielded reduction of the average positron lifetimes. Surface photovoltage, positron annihilation, and photoluminescence spectra consistently showed sample-to-sample differences due to the variation in the overall quality of the nanopowders, which partially obscures observation of the scaling effects. However, the results demonstrated that our approach is efficient in detecting specific surface states in nanoscale ZnO specimens and in elucidating their nature.

  4. Plutonium uptake by Scenedesmus obliquus as a function of isotope and oxidation state

    International Nuclear Information System (INIS)

    Tkacik, M.F.; Giesy, J.P.; Wilhite, E.L.; Corey, J.C.

    1979-01-01

    Uptake of 238 Pu 4+ , 238 Pu 6+ , 239 Pu 4+ and 239 Pu 6+ by the green alga Scenedesmus obliquus (Turp) Kutz was studied to determine whether isotope or oxidation state differences affect Pu uptake from aqueous medium by algal cells. At equivalent 238 Pu and 239 PU concentrations, even when initial oxidation states differed, accumulations of these isotopes by S.obliquus were not significantly (p>0.05) different. Plutonium accumulation by S.obliquus was log-linear. (author)

  5. Model analyses of atmospheric mercury: present air quality and effects of transpacific transport on the United States

    Science.gov (United States)

    Lei, H.; Liang, X.-Z.; Wuebbles, D. J.; Tao, Z.

    2013-11-01

    Atmospheric mercury is a toxic air and water pollutant that is of significant concern because of its effects on human health and ecosystems. A mechanistic representation of the atmospheric mercury cycle is developed for the state-of-the-art global climate-chemistry model, CAM-Chem (Community Atmospheric Model with Chemistry). The model simulates the emission, transport, transformation and deposition of atmospheric mercury (Hg) in three forms: elemental mercury (Hg(0)), reactive mercury (Hg(II)), and particulate mercury (PHg). Emissions of mercury include those from human, land, ocean, biomass burning and volcano related sources. Land emissions are calculated based on surface solar radiation flux and skin temperature. A simplified air-sea mercury exchange scheme is used to calculate emissions from the oceans. The chemistry mechanism includes the oxidation of Hg(0) in gaseous phase by ozone with temperature dependence, OH, H2O2 and chlorine. Aqueous chemistry includes both oxidation and reduction of Hg(0). Transport and deposition of mercury species are calculated through adapting the original formulations in CAM-Chem. The CAM-Chem model with mercury is driven by present meteorology to simulate the present mercury air quality during the 1999-2001 period. The resulting surface concentrations of total gaseous mercury (TGM) are then compared with the observations from worldwide sites. Simulated wet depositions of mercury over the continental United States are compared to the observations from 26 Mercury Deposition Network stations to test the wet deposition simulations. The evaluations of gaseous concentrations and wet deposition confirm a strong capability for the CAM-Chem mercury mechanism to simulate the atmospheric mercury cycle. The general reproduction of global TGM concentrations and the overestimation on South Africa indicate that model simulations of TGM are seriously affected by emissions. The comparison to wet deposition indicates that wet deposition patterns

  6. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; John Noetzel; Larry Chick

    2003-12-08

    The objective of Phase I under this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from January 1, 2003 to June 30, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; and Task 9 Stack Testing with Coal-Based Reformate.

  7. Environmental geology in the United States: Present practice and future training needs

    Science.gov (United States)

    Lundgren, Lawrence

    Environmental geology as practiced in the United States confronts issues in three large areas: Threats to human society from geologic phenomena (geologic hazards); impacts of human activities on natural systems (environmental impact), and natural-resource management. This paper illustrates present U.S. practice in environmental geology by sampling the work of 7 of the 50 state geological surveys and of the United States Geological Survey as well. Study of the work of these agencies provides a basis for identifying avenues for the training of those who will deal with environmental issues in the future. This training must deal not only with the subdisciplines of geology but with education to cope with the ethical, interdisciplinary, and public-communication aspects of the work of the environmental geologist.

  8. Theoretical studies of positron states and annihilation characteristics at the oxidized Cu(100) surface

    Energy Technology Data Exchange (ETDEWEB)

    Fazleev, N. G. [Department of Physics, Box 19059, University of Texas at Arlington, Arlington Texas 76019 (United States) and Institute of Physics, Kazan Federal University, Kremlevskaya18, Kazan 420008 (Russian Federation); Weiss, A. H. [Department of Physics, Box 19059, University of Texas at Arlington, Arlington Texas 76019 (United States)

    2013-04-19

    In this work we present the results of theoretical studies of positron surface and bulk states and annihilation probabilities of surface-trapped positrons with relevant core electrons at the oxidized Cu(100) surface under conditions of high oxygen coverage. An ab-initio study of the electronic properties of the Cu(100) missing row reconstructed surface at various on surface and sub-surface oxygen coverages has been performed on the basis of the density functional theory (DFT) using the Dmol3 code and the generalized gradient approximation (GGA). Surface structures in calculations have been constructed by adding oxygen atoms to various surface hollow and sub-surface octahedral sites of the 0.5 monolayer (ML) missing row reconstructed phase of the Cu(100) surface with oxygen coverages ranging from 0.5 to 1.5 ML. The charge redistribution at the surface and variations in atomic structure and chemical composition of the topmost layers associated with oxidation and surface reconstruction have been found to affect the spatial extent and localization of the positron surface state wave function and annihilation probabilities of surface trapped positrons with relevant core electrons. Theoretical results are compared with experimental data obtained from studies of oxidation of the Cu(100) surface using positron annihilation induced Auger electron spectroscopy (PAES). It has been shown that positron annihilation probabilities with Cu 3s and 3p core electrons decrease when total (on-surface and sub-surface) oxygen coverage of the Cu(100) surface increases up to 1 ML. The calculations show that for high oxygen coverage when total oxygen coverage is 1. 5 ML the positron is not bound to the surface.

  9. Language Presentation of Characters’ Sleeping State A.P. Chekhov’s "Drama on Hunting"

    Directory of Open Access Journals (Sweden)

    Li Kho

    2017-10-01

    Full Text Available The state of sleep is the natural physiological state of a person that is necessary to continue life, therefore this state can be described in a work of art when characterizing the characters, especially when the dream is broken, and also in the event of dreams. Dreams in the artistic text allow the reader to penetrate into the depths of the psychic sphere of the character. In the story by A.P. Chekhov «Drama on Hunting» dreams that contain certain events and represent certain substances are associated with those phenomena that occurred in the life of the main character Zinoviev. At the same time, they describe the unreal substances and events, which, as it becomes clear later, have a prophetic character. The state of sleep, its violation, the idea of what can dream, why this dreaming occur, the characterization of sleep given by another character has to do with the inner psychological state of different characters. Thus, the reader is presented with the sphere of the unconscious, it is possible to determine the significance of this sphere in the life of the characters of the story.

  10. Oxidative stress markers in hypertensive states of pregnancy: preterm and term disease.

    Directory of Open Access Journals (Sweden)

    Lesia Olha Kurlak

    2014-08-01

    Full Text Available Discussion continues as to whether de novo hypertension in pregnancy with significant proteinuria (pre-eclampsia; PE and non-proteinuric new hypertension (gestational hypertension; GH are parts of the same disease spectrum or represent different conditions. Non-pregnant hypertension, pregnancy and PE are all associated with oxidative stress. We have established a 6 weeks post-partum clinic for women who experienced a hypertensive pregnancy. We hypothesized that PE and GH could be distinguished by markers of oxidative stress; thiobarbituric acid reactive substances (TBARS and antioxidants (ferric ion reducing ability of plasma; FRAP. Since the severity of PE and GH is greater pre-term, we also compared pre-term and term disease. Fifty-eight women had term PE, 23 pre-term PE, 60 had term GH and 6 pre-term GH, 11 pre-existing (essential hypertension (EH without PE. Limited data were available from normotensive pregnancies (n=7 and non-pregnant controls (n=14. There were no differences in postpartum TBARS or FRAP between hypertensive states; TBARS (P=0.001 and FRAP (P=0.009 were lower in plasma of non-pregnant controls compared to recently-pregnant women. Interestingly FRAP was higher in preterm than term GH (P=0.013. In PE and GH, TBARS correlated with low density lipoprotein (LDL-cholesterol (P=0.036; this association strengthened with inclusion of EH ((P=0.011. The 10 year Framingham index for cardiovascular risk was positively associated with TBARS (P=0.003.Oxidative stress profiles do not differ between hypertensive states but appear to distinguish between recently-pregnant and non-pregnant states. This suggests that pregnancy may alter vascular integrity with changes remaining 6 weeks postpartum. LDL-cholesterol is a known determinant of oxidative stress in cardiovascular disease and we have shown this association to be present in hypertensive pregnancy further emphasizing that such a pregnancy may be revealing a pre-existing cardiovascular

  11. Large natural draught cooling towers of reinforced concrete - present state and future developments

    International Nuclear Information System (INIS)

    Kraetzig, W.B.

    1975-01-01

    The paper attempts to give a survey of the present state of safety theory as well as of construction and erection of reinforced-concrete natural draught cooling towers. Today these constructions have reached heights of over 150 m and may be built still higher. From the point of view of safety and relibility this is undoubtedly possible. From an economical point of view, new constructional elements will probably have to be introduced into the design. (orig./AK) [de

  12. Development of the electric power system in Macedonia - past, present, future state

    International Nuclear Information System (INIS)

    1996-01-01

    The first part presents an overview of the chronological development of the Electric Power System (EPS) of Macedonia. The second part is dedicated to its present situation and to the actual operation conditions and problems in this regard. The third part describes the development engagements. These engagements are directed on one hand, towards finding solutions for the energy conditions in the next 5-10 years and, on the other hand, towards the preparation of the electrical plants and objects for the next 25-40 years, which are determined by various development parameters for the general and industrial progress of the state. (author)

  13. Moessbauer effect study of oxidation and coordination states of iron in some sodium borate glasse:;

    International Nuclear Information System (INIS)

    Eissa, N.A.; Sanad, A.M.; Youssef, S.M.; El-Henawii, S.A.; Gomaa, S.Sh.; Mostafa, A.G.

    1980-01-01

    A structural study of some sodium borate glasses containing iron was carried out applying ME spectroscopy. Both oxidation and coordination states of iron were investigated under the effect of gradual replacing of sodium carbonate by sodium nitrate in the glass batches. The glasses were melted in porcelain crucibles using an electrically heated furnace at 1000+-10 deg C, then were quenched on a steel plate at room temperature (R.T.). The ME source was 20 mCi radioactive Co-57 in chromium. The obtained ME spectra indicated that at lower sodium nitrate content both Fe 2+ and Fe 3+ are present in these glasses. At moderate concentrations some Fe 3+ ions were separated in a crystalline phase and the rest of the iron ions appeared as ferric ions in glassy state. At high sodium nitrate content only Fe 3+ ions in glassy state were detected. The values of the ME parameters for all iron ions indicated that all of them are in the octahedral coordination state. The density measurements confirm the separation of a crystalline phase at moderate sodium nitrate content. (author)

  14. SOLID STATE ENERGY CONVERSION ALLIANCE DELPHI SOLID OXIDE FUEL CELL

    Energy Technology Data Exchange (ETDEWEB)

    Steven Shaffer; Sean Kelly; Subhasish Mukerjee; David Schumann; Gail Geiger; Kevin Keegan; Larry Chick

    2004-05-07

    The objective of this project is to develop a 5 kW Solid Oxide Fuel Cell power system for a range of fuels and applications. During Phase I, the following will be accomplished: Develop and demonstrate technology transfer efforts on a 5 kW stationary distributed power generation system that incorporates steam reforming of natural gas with the option of piped-in water (Demonstration System A). Initiate development of a 5 kW system for later mass-market automotive auxiliary power unit application, which will incorporate Catalytic Partial Oxidation (CPO) reforming of gasoline, with anode exhaust gas injected into an ultra-lean burn internal combustion engine. This technical progress report covers work performed by Delphi from July 1, 2003 to December 31, 2003, under Department of Energy Cooperative Agreement DE-FC-02NT41246. This report highlights technical results of the work performed under the following tasks: Task 1 System Design and Integration; Task 2 Solid Oxide Fuel Cell Stack Developments; Task 3 Reformer Developments; Task 4 Development of Balance of Plant (BOP) Components; Task 5 Manufacturing Development (Privately Funded); Task 6 System Fabrication; Task 7 System Testing; Task 8 Program Management; Task 9 Stack Testing with Coal-Based Reformate; and Task 10 Technology Transfer from SECA CORE Technology Program. In this reporting period, unless otherwise noted Task 6--System Fabrication and Task 7--System Testing will be reported within Task 1 System Design and Integration. Task 8--Program Management, Task 9--Stack Testing with Coal Based Reformate, and Task 10--Technology Transfer from SECA CORE Technology Program will be reported on in the Executive Summary section of this report.

  15. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  16. Gender, Party, and Presentation of Family in the Social Media Profiles of 10 State Legislatures

    Directory of Open Access Journals (Sweden)

    James M. Cook

    2016-04-01

    Full Text Available Recent research has identified neither consistent gendered stereotypes about legislators among constituents, nor a link between legislators’ gender and their electoral success, nor consistent gender coalitions in legislative voting and co-sponsorship. However, it would be premature to declare that gender is irrelevant to legislative politics. This article considers state legislators’ choice to discuss or omit family in their social media profiles and interprets the choice as a gendered presentation of self. The social media platform Twitter is notable for its status as an especially public stage and for the narrow choice that limited profile space imposes. Different strains in gender theory lead to competing predictions: that women will avoid references to family to avoid making gender salient, that women will highlight references to family to avoid backlash for non-normativity, or that differing gender expectations in different political parties lead to different gender effects. Apart from gender, family references may be more or less available to legislators as a function of their own family status and life stage. Analysis of Twitter profiles of state legislators in 10 US states (N = 911 reveals that party and gender effects interact; controlling for family and life stage circumstances, non-Republican women are moderately more likely to mention family than non-Republican men, but Republican women are much less likely to mention family than Republican men. Gender matters in the social media presentation of legislators’ selves, but in a manner strongly conditioned by party expectations.

  17. The neutrino in all its states - Seminar dedicated to Jacques Bouchez - Slides of the presentations

    International Nuclear Information System (INIS)

    Spiro, M.; Pessard, H.; Rubbia, A.; Petcov, S.; Cousins, B.; Fechner, M.; Mezetto, M.

    2011-01-01

    The present scientific seminar, organized in the memory of Jacques Bouchez is centered on neutrino physics and presents the state of the art on experiments, on future projects and on the theory of neutrinos (oscillations and MSW effect). This document is made up of the slides of 7 presentations: 1) The achievements of J.Bouchez; 2) Reactor neutrino experiments from Bugey to double-Chooz (via RENO and Daya-Bay); 3) Neutrinos and accelerators: on the way toward the third flavor (NOMA, OPERA and T2K experiments); 4) Neutrino oscillations and MSW effect; 5) Some statistical questions in neutrino physics; 6) Long baseline oscillations: towards Japan future neutrino oscillation experiments; and 7) Next generation of neutrino oscillation experiments. (A.C.)

  18. Approaches to Determining the Oxidation State of Nitrogen and Carbon Atoms in Organic Compounds for High School Students

    Science.gov (United States)

    Jurowski, Kamil; Krzeczkowska, Malgorzata Krystyna; Jurowska, Anna

    2015-01-01

    The concept of oxidation state (or oxidation number) and related issues have always been difficult for students. In addition, there are misunderstandings and obscurities, which can cause improper balancing of the chemical equations (mostly in organic reactions). In particular, these problems are related to determination of the oxidation state of…

  19. Phase Behavior and Equations of State of the Actinide Oxides

    Science.gov (United States)

    Chidester, B.; Pardo, O. S.; Panero, W. R.; Fischer, R. A.; Thompson, E. C.; Heinz, D. L.; Prescher, C.; Prakapenka, V. B.; Campbell, A.

    2017-12-01

    The distribution of the long-lived heat-producing actinide elements U and Th in the deep Earth has important implications for the dynamics of the mantle and possibly the energy budget of Earth's core. The low shear velocities of the Large Low-Shear Velocity Provinces (LLSVPs) on the core-mantle boundary suggests that these regions are at least partially molten and may contain concentrated amounts of the radioactive elements, as well as other large cations such as the rare Earth elements. As such, by exploring the phase behavior of actinide-bearing minerals at extreme conditions, some insight into the mineralogy, formation, and geochemical and geodynamical effects of these regions can be gained. We have performed in situ high-pressure, high-temperature synchrotron X-ray diffraction experiments and calculations on two actinide oxide materials, UO2 and ThO2, to determine their phase behavior at the extreme conditions of the lower mantle. Experiments on ThO2 reached 60 GPa and 2500 K, and experiments on UO2 reached 95 GPa and 2500 K. We find that ThO2 exists in the fluorite-type structure to 20 GPa at high temperatures, at which point it transforms to the high-pressure cotunnite-type structure and remains thus up to 60 GPa. At room temperature, an anomalous expansion of the fluorite structure is observed prior to the transition, and may signal anion sub-lattice disorder. Similarly, UO2 exists in the fluorite-type structure at ambient conditions and up to 28 GPa at high temperatures. Above these pressures, we have observed a previously unidentified phase of UO2 with a tetragonal structure as the lower-temperature phase and the cotunnite-type phase at higher temperatures. Above 78 GPa, UO2 undergoes another transition or possible dissociation into two separate oxide phases. These phase diagrams suggest that the actinides could exist as oxides in solid solution with other analogous phases (e.g. ZrO2) in the cotunnite-type structure throughout much of Earth's lower mantle.

  20. On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states

    Energy Technology Data Exchange (ETDEWEB)

    Kiselev, Yurii M [Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow (Russian Federation)

    2009-01-31

    The state-of-the-art in matrix stabilisation of d- and f-transition metal ions in unstable oxidation states is analysed. Main aspects of this problem concerning the genealogy of appropriate matrix systems are classified. Relevant examples are given and the data that contradict the scheme proposed are discussed. The thermodynamics of the matrix stabilisation effect is considered using the concept of isomorphic miscibility. The influence of defects and non-equilibrium on the matrix stabilisation effect is discussed. The problem of identification of the oxidation states in matrix systems is examined and various types of matrix systems are considered.

  1. On matrix stabilisation of d- and f-transition metal ions in unstable oxidation states

    International Nuclear Information System (INIS)

    Kiselev, Yurii M

    2009-01-01

    The state-of-the-art in matrix stabilisation of d- and f-transition metal ions in unstable oxidation states is analysed. Main aspects of this problem concerning the genealogy of appropriate matrix systems are classified. Relevant examples are given and the data that contradict the scheme proposed are discussed. The thermodynamics of the matrix stabilisation effect is considered using the concept of isomorphic miscibility. The influence of defects and non-equilibrium on the matrix stabilisation effect is discussed. The problem of identification of the oxidation states in matrix systems is examined and various types of matrix systems are considered.

  2. Oxidation-state distribution of plutonium in surface and subsurface waters at Thule, northwest Greenland

    DEFF Research Database (Denmark)

    McMahon, C.A.; Vintró, L.L.; Mitchell, P.I.

    2000-01-01

    (V, VI) (mean, 68 +/- 6%; n = 6), with little if any distinction apparent between surface and bottom waters. Further, the oxidation state distribution at stations close to the accident site is similar to that measured at Upernavik, remote from this site. It is also similar to the distribution observed...... in shelf waters at midlatitudes, suggesting that the underlying processes controlling plutonium speciation are insensitive to temperature over the range 0-25 degrees C. Measurements using tangential-flow ultrafiltration indicate that virtually all of the plutonium (including the fraction in a reduced...... chemical form) is present as fully dissolved species. Most of this plutonium would seem to be of weapons fallout origin, as the mean Pu-238/Pu-239,Pu-240 activity ratio in the water column (dissolved phase) at Thule (0.06 +/- 0.02; n = 10) is similar to the global fallout ratio at this latitude...

  3. Adsorption properties versus oxidation states of rutile TiO2(110)

    DEFF Research Database (Denmark)

    Martinez, Umberto; Hammer, Bjørk

    2011-01-01

    Using density functional theory we have studied the adsorption properties of different atoms and molecules deposited on a stoichiometric, reduced, and oxidized rutile TiO2(110) surface. Depending on the oxidation state of the surface, electrons can flow from or to the substrate and, therefore...... of the charge flow depends on the oxidation state of the rutile surface and on the adsorption site. Generally, the charging effect leads to more stable complexes. However, the increase in the binding energy of the adsorbates is highly dependent on the electronic states of the surface prior to the adsorption...... event. In this work we have analyzed in details these mechanisms and we have also established a direct correlation between the enhanced binding energy of the adsorbates and the induced gap states...

  4. Microanalysis of iron oxidation state in iron oxides using X Ray Absorption Near Edge Structure (XANES)

    Science.gov (United States)

    Sutton, S. R.; Delaney, J.; Bajt, S.; Rivers, M. L.; Smith, J. V.

    1993-01-01

    An exploratory application of x ray absorption near edge structure (XANES) analysis using the synchrotron x ray microprobe was undertaken to obtain Fe XANES spectra on individual sub-millimeter grains in conventional polished sections. The experiments concentrated on determinations of Fe valence in a suite of iron oxide minerals for which independent estimates of the iron speciation could be made by electron microprobe analysis and x ray diffraction.

  5. Exploratory Characterization of Phenolic Compounds with Demonstrated Anti-Diabetic Activity in Guava Leaves at Different Oxidation States

    Directory of Open Access Journals (Sweden)

    Elixabet Díaz-de-Cerio

    2016-05-01

    Full Text Available Psidium guajava L. is widely used like food and in folk medicine all around the world. Many studies have demonstrated that guava leaves have anti-hyperglycemic and anti-hyperlipidemic activities, among others, and that these activities belong mainly to phenolic compounds, although it is known that phenolic composition in guava tree varies throughout seasonal changes. Andalusia is one of the regions in Europe where guava is grown, thus, the aim of this work was to study the phenolic compounds present in Andalusian guava leaves at different oxidation states (low, medium, and high. The phenolic compounds in guava leaves were determined by HPLC-DAD-ESI-QTOF-MS. The results obtained by chromatographic analysis reported that guava leaves with low degree of oxidation had a higher content of flavonols, gallic, and ellagic derivatives compared to the other two guava leaf samples. Contrary, high oxidation state guava leaves reported the highest content of cyanidin-glucoside that was 2.6 and 15 times higher than guava leaves with medium and low oxidation state, respectively. The QTOF platform permitted the determination of several phenolic compounds with anti-diabetic properties and provided new information about guava leaf phenolic composition that could be useful for nutraceutical production.

  6. Exploratory Characterization of Phenolic Compounds with Demonstrated Anti-Diabetic Activity in Guava Leaves at Different Oxidation States.

    Science.gov (United States)

    Díaz-de-Cerio, Elixabet; Verardo, Vito; Gómez-Caravaca, Ana María; Fernández-Gutiérrez, Alberto; Segura-Carretero, Antonio

    2016-05-11

    Psidium guajava L. is widely used like food and in folk medicine all around the world. Many studies have demonstrated that guava leaves have anti-hyperglycemic and anti-hyperlipidemic activities, among others, and that these activities belong mainly to phenolic compounds, although it is known that phenolic composition in guava tree varies throughout seasonal changes. Andalusia is one of the regions in Europe where guava is grown, thus, the aim of this work was to study the phenolic compounds present in Andalusian guava leaves at different oxidation states (low, medium, and high). The phenolic compounds in guava leaves were determined by HPLC-DAD-ESI-QTOF-MS. The results obtained by chromatographic analysis reported that guava leaves with low degree of oxidation had a higher content of flavonols, gallic, and ellagic derivatives compared to the other two guava leaf samples. Contrary, high oxidation state guava leaves reported the highest content of cyanidin-glucoside that was 2.6 and 15 times higher than guava leaves with medium and low oxidation state, respectively. The QTOF platform permitted the determination of several phenolic compounds with anti-diabetic properties and provided new information about guava leaf phenolic composition that could be useful for nutraceutical production.

  7. Exploratory Characterization of Phenolic Compounds with Demonstrated Anti-Diabetic Activity in Guava Leaves at Different Oxidation States

    Science.gov (United States)

    Díaz-de-Cerio, Elixabet; Verardo, Vito; Gómez-Caravaca, Ana María; Fernández-Gutiérrez, Alberto; Segura-Carretero, Antonio

    2016-01-01

    Psidium guajava L. is widely used like food and in folk medicine all around the world. Many studies have demonstrated that guava leaves have anti-hyperglycemic and anti-hyperlipidemic activities, among others, and that these activities belong mainly to phenolic compounds, although it is known that phenolic composition in guava tree varies throughout seasonal changes. Andalusia is one of the regions in Europe where guava is grown, thus, the aim of this work was to study the phenolic compounds present in Andalusian guava leaves at different oxidation states (low, medium, and high). The phenolic compounds in guava leaves were determined by HPLC-DAD-ESI-QTOF-MS. The results obtained by chromatographic analysis reported that guava leaves with low degree of oxidation had a higher content of flavonols, gallic, and ellagic derivatives compared to the other two guava leaf samples. Contrary, high oxidation state guava leaves reported the highest content of cyanidin-glucoside that was 2.6 and 15 times higher than guava leaves with medium and low oxidation state, respectively. The QTOF platform permitted the determination of several phenolic compounds with anti-diabetic properties and provided new information about guava leaf phenolic composition that could be useful for nutraceutical production. PMID:27187352

  8. Boiler recirculation pumps for nuclear power stations - present state of development. Directions for planning, operational experience

    International Nuclear Information System (INIS)

    Mattias, H.B.

    1976-01-01

    Boiler recirculation pumps are important components of modern power stations. The development of large recirculation pumps up to a driving power of 1,500 kW was faced with some problems in meeting the plant requirements. In this paper, the present state of development is dealt with. The development problems in the fields of hydrodynamics, cavitation, corrosion and erosion are dealt with as well as the problems of the design of the casing with regard to thermodynamics and strength. Finally, operational experience with the boiler recirculation pump for 600 MW power stations will be reported on. (orig./AK) [de

  9. EC-directive optical radiation - present state of consultation; EG-Richtlinie optische Strahlung - aktueller Beratungsstand

    Energy Technology Data Exchange (ETDEWEB)

    Pipke, R. [Bundesanstalt fuer Arbeitschutz und Arbeitsmedizin, Dortmund (Germany)

    2004-07-01

    The draft of a directive on the protection of workers from risks related to radiation in the range from 100 nm to 1 mm (Laser, UV-radiation) is discussed on EC-level. The European concept of regulations on occupational safety and health is outlined and put into reference with other directives on the protection against physical agents (vibrations, noise, electromagnetic fields). Building up on this the present state of consultation of a directive on optical radiation is represented, including major points of consideration. (orig.)

  10. The present state of research on the vitrification of concentrated solutions of fission products (1962)

    International Nuclear Information System (INIS)

    Bonniaud, R.; Sombret, C.

    1961-01-01

    The present report gives the actual point of studies on vitrification of concentrated solutions of fission products. An active cell, giving glasses in crucibles, permitted to study various glass compositions. The leaching rate from the glass raises 1 to 2 10 -7 g of glass/cm 2 /day. Activity loss by volatility during vitrification remains weak and often below 0.1 per cent of total activity. Off gas cleaning is made easier by presence of filter which is compound of granules including iron oxide. After saturation the content of this filter can be melt. Moreover different processes are in experimentation for a more important production. Daily 72 liters of solution containing tracer activity are treated in a continuous calcination and vitrification plant. The loss in 106 Ru is still important and a modification of installation has been necessary. A pot vitrification plant is in study. In order to reduce cost of processing the possibility to pour glass after melting is actuality in study. A production set of very active glass is also in project. (authors) [fr

  11. Determination of oxidation state of iron in normal and pathologically altered human aortic valves

    Energy Technology Data Exchange (ETDEWEB)

    Czapla-Masztafiak, J. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Kraków (Poland); Lis, G.J.; Gajda, M.; Jasek, E. [Department of Histology, Jagiellonian University Medical College, Kopernika 7, 31-034 Kraków (Poland); Czubek, U. [Department of Coronary Disease, Jagiellonian University Medical College, John Paul II Hospital, Prądnicka 80, 31-202 Kraków (Poland); Bolechała, F. [Department of Forensic Medicine, Jagiellonian University Medical College, Grzegórzecka 16, 31-531 Kraków (Poland); Borca, C. [Swiss Light Source, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Kwiatek, W.M. [Institute of Nuclear Physics PAN, Radzikowskiego 152, 31-342 Kraków (Poland)

    2015-12-01

    In order to investigate changes in chemical state of iron in normal and pathologically altered human aortic valves X-ray absorption spectroscopy was applied. Since Fe is suspected to play detrimental role in aortic valve stenosis pathogenesis the oxidation state of this element has been determined. The experimental material consisted of 10 μm sections of valves excised during routine surgery and from autopsies. The experiment was performed at the MicroXAS beamline of the SLS synchrotron facility in Villigen (Switzerland). The Fe K-edge XANES spectra obtained from tissue samples were carefully analyzed and compared with the spectra of reference compounds containing iron in various chemical structures. The analysis of absorption edge position and shape of the spectra revealed that both chemical forms of iron are presented in valve tissue but Fe{sup 3+} is the predominant form. Small shift of the absorption edge toward higher energy in the spectra from stenotic valve samples indicates higher content of the Fe{sup 3+} form in pathological tissue. Such a phenomenon suggests the role of Fenton reaction and reactive oxygen species in the etiology of aortic valve stenosis. The comparison of pre-edge regions of XANES spectra for control and stenotic valve tissue confirmed no differences in local symmetry or spin state of iron in analyzed samples.

  12. The oxidation states of elements in pure and Ca-doped BiCuSeO thermoelectric oxides

    International Nuclear Information System (INIS)

    Hsiao, Chun-Lung; Qi, Xiaoding

    2016-01-01

    Bi 1−x Ca x CuSeO (x = 0–0.3) was synthesized at 650 °C in an air-tight system flowing with pure argon. The Ca doping resulted in an increase in the thermoelectric figure of merit (ZT) as the consequence of increased carrier concentration. X-ray photoelectron spectroscopy (XPS) was carried out to check the oxidation states in Bi 1−x Ca x CuSeO. The results indicated that in addition to the expected Bi 3+ and Cu 1+ , there existed Bi 2+ and Cu 2+ in the undoped BiCuSeO, whereas in the Ca-doped BiCuSeO, Bi 4+ , Cu 3+ and Cu 2+ were observed. The Ca dopant was confirmed to be in the 2+ oxidation state. Two broad peaks centered at 54.22 and 58.59 eV were recorded in the vicinity around the binding energy of Se 3d. The former is often observed in the Se-containing intermetallics while the latter is often found in the Se-containing oxides, indicating that along with the expected Se–Cu bonding, a bonding between Se and O may also exist. Based on the XPS results, the charge compensation mechanisms were proposed for Bi 1−x Ca x CuSeO, which may shed some light on the origins of charge carriers. BiCuSeO based oxides have recently be discovered to have a large ZT comparable to the best alloys currently in use, because of the large Seebeck coefficient and small thermal conductivity. However, their electrical conductivity is lower compared to the best thermoelectrics. This work may provide some hints for the further improvement of ZT in BiCuSeO based oxides. - Graphical abstract: The oxidation states, charge compensation mechanisms, and origins of charge carriers in Bi 1−x Ca x CuSeO thermoelectrics. Display Omitted

  13. The Oxidation State of Fe in Glasses from the Galapagos Archipelago: Variable Oxygen Fugacity as a Function of Mantle Source

    Science.gov (United States)

    Peterson, M. E.; Kelley, K. A.; Cottrell, E.; Saal, A. E.; Kurz, M. D.

    2015-12-01

    The oxidation state of the mantle plays an intrinsic role in the magmatic evolution of the Earth. Here we present new μ-XANES measurements of Fe3+/ΣFe ratios (a proxy for ƒO2) in a suite of submarine glasses from the Galapagos Archipelago. Using previously presented major, trace, and volatile elements and isotopic data for 4 groups of glass that come from distinct mantle sources (depleted upper mantle, 2 recycled, and a primitive mantle source) we show that Fe3+/ΣFe ratios vary both with the influence of shallow level processes and with variations in mantle source. Fe3+/ΣFe ratios increase with differentiation (i.e. decreasing MgO), but show a large variation at a given MgO. Progressive degassing of sulfur accompanies decreasing Fe3+/ΣFe ratios, while assimilation of hydrothermally altered crust (as indicated by increasing Sr/Sr*) is shown to increase Fe3+/ΣFe ratios. After taking these processes into account, there is still variability in the Fe3+/ΣFe ratios of the isotopically distinct sample suites studied, yielding a magmatic ƒO2 that ranges from ΔQFM = +0.16 to +0.74 (error ITE = enriched Sr and Pb isotopes) shows evidence of mixing between oxidized and reduced sources (ITE oxidized end-member = 0.177). This suggests that mantle sources in the Galapagos that are thought to contain recycled components (i.e., WD and ITE groups) have distinct oxidation states. The high 3He/4He Fernandina samples (HHe group) are shown to be the most oxidized (ave. 0.175 ± 0.006). With C/3He ratios an order of magnitude greater than MORB this suggests that the primitive mantle is a more carbonated and oxidized source than the depleted upper mantle.

  14. Ab initio molecular dynamics simulation of aqueous solution of nitric oxide in different formal oxidation states

    Science.gov (United States)

    Venâncio, Mateus F.; Rocha, Willian R.

    2015-10-01

    Ab initio molecular dynamics simulations were used to investigate the early chemical events involved in the dynamics of nitric oxide (NOrad), nitrosonium cation (NO+) and nitroxide anion (NO-) in aqueous solution. The NO+ ion is very reactive in aqueous solution having a lifetime of ∼4 × 10-13 s, which is shorter than the value of 3 × 10-10 s predicted experimentally. The NO+ reacts generating the nitrous acid as an intermediate and the NO2- ion as the final product. The dynamics of NOrad revealed the reversibly formation of a transient anion radical species HONOrad -.

  15. Molecular beam epitaxy growth of niobium oxides by solid/liquid state oxygen source and lithium assisted metal-halide chemistry

    Science.gov (United States)

    Tellekamp, M. Brooks; Greenlee, Jordan D.; Shank, Joshua C.; Doolittle, W. Alan

    2015-09-01

    In order to consistently grow high quality niobium oxides and lithium niobium oxides, a novel solid/liquid state oxygen source, LiClO4, has been implemented in a molecular beam epitaxy (MBE) system. LiClO4 is shown to decompose into both molecular and atomic oxygen upon heating. This allows oxidation rates similar to that of molecular oxygen but at a reduced overall beam flux, quantified by in situ Auger analysis. LiClO4 operation is decomposition limited to less than 400 °C, and other material limitations are identified. The design of a custom near-ambient NbCl5 effusion cell is presented, which improves both short and long term stability. Films of Nb oxidation state +2, +3, and +5 are grown using these new tools, including the multi-functional sub-oxide LiNbO2.

  16. Present state and future of CFD based on three-dimensional RANS analysis

    International Nuclear Information System (INIS)

    Kim, Kwang Yong

    2004-01-01

    Computational Fluid Dynamics (CFD) based on Navier-Stokes equations has been developed rapidly for several decades with the developments of high speed computers and numerical algorithms, and presently is regarded as an essential analysis tool in the engineering applications containing fluid flow and convective heat transfer. It is known that for turbulent flow the Navier-Stokes equations can be calculated precisely by Direct Numerical Simulation (DNS). However, DNS needs huge computing time even for simple low-Reynolds number flows, and thus is not practical. Large Eddy Simulation (LES) can be an alternative. But, LES also needs considerable computing time for the analysis of engineering flows, and have some problem in the methods. Therefore, the analysis methods using Reynolds-averaged Navier-stokes equations (RANS) and turbulence closure models are still regarded as the major techniques for the analysis of turbulent flows in spite of the inaccuracy of the prediction. In this presentation, the present state and the prospect of CFD based on three-dimensional RANS analysis are introduced for physical models and numerical algorithms with the engineering examples. Especially, for the analysis of two-phase flows in nuclear reactor, the recently developed techniques are also introduced. And, the presentation includes the methods of design optimization using RANS analysis and numerical optimization techniques with variety of the applications

  17. 99Tc and Re incorporated into metal oxide polyoxometalates: oxidation state stability elucidated by electrochemistry and theory.

    Science.gov (United States)

    McGregor, Donna; Burton-Pye, Benjamin P; Mbomekalle, Israel M; Aparicio, Pablo A; Romo, Susanna; López, Xavier; Poblet, Josep M; Francesconi, Lynn C

    2012-08-20

    The radioactive element technetium-99 ((99)Tc, half-life = 2.1 × 10(5) years, β(-) of 253 keV), is a major byproduct of (235)U fission in the nuclear fuel cycle. (99)Tc is also found in radioactive waste tanks and in the environment at National Lab sites and fuel reprocessing centers. Separation and storage of the long-lived (99)Tc in an appropriate and stable waste-form is an important issue that needs to be addressed. Considering metal oxide solid-state materials as potential storage matrixes for Tc, we are examining the redox speciation of Tc on the molecular level using polyoxometalates (POMs) as models. In this study we investigate the electrochemistry of Tc complexes of the monovacant Wells-Dawson isomers, α(1)-P(2)W(17)O(61)(10-) (α1) and α(2)-P(2)W(17)O(61)(10-) (α2) to identify features of metal oxide materials that can stabilize the immobile Tc(IV) oxidation state accessed from the synthesized Tc(V)O species and to interrogate other possible oxidation states available to Tc within these materials. The experimental results are consistent with density functional theory (DFT) calculations. Electrochemistry of K(7-n)H(n)[Tc(V)O(α(1)-P(2)W(17)O(61))] (Tc(V)O-α1), K(7-n)H(n)[Tc(V)O(α(2)-P(2)W(17)O(61))] (Tc(V)O-α2) and their rhenium analogues as a function of pH show that the Tc-containing derivatives are always more readily reduced than their Re analogues. Both Tc and Re are reduced more readily in the lacunary α1 site as compared to the α2 site. The DFT calculations elucidate that the highest oxidation state attainable for Re is VII while, under the same electrochemistry conditions, the highest oxidation state for Tc is VI. The M(V)→ M(IV) reduction processes for Tc(V)O-α1 are not pH dependent or only slightly pH dependent suggesting that protonation does not accompany reduction of this species unlike the M(V)O-α2 (M = (99)Tc, Re) and Re(V)O-α1 where M(V/IV) reduction process must occur hand in hand with protonation of the terminal M═O to

  18. Carbon oxidation state as a metric for describing the chemistry of atmospheric organic aerosol

    Energy Technology Data Exchange (ETDEWEB)

    Massachusetts Institute of Technology; Kroll, Jesse H.; Donahue, Neil M.; Jimenez, Jose L.; Kessler, Sean H.; Canagaratna, Manjula R.; Wilson, Kevin R.; Altieri, Katye E.; Mazzoleni, Lynn R.; Wozniak, Andrew S.; Bluhm, Hendrik; Mysak, Erin R.; Smith, Jared D.; Kolb, Charles E.; Worsnop, Douglas R.

    2010-11-05

    A detailed understanding of the sources, transformations, and fates of organic species in the environment is crucial because of the central roles that organics play in human health, biogeochemical cycles, and Earth's climate. However, such an understanding is hindered by the immense chemical complexity of environmental mixtures of organics; for example, atmospheric organic aerosol consists of at least thousands of individual compounds, all of which likely evolve chemically over their atmospheric lifetimes. Here we demonstrate the utility of describing organic aerosol (and other complex organic mixtures) in terms of average carbon oxidation state (OSC), a quantity that always increases with oxidation, and is readily measured using state-of-the-art analytical techniques. Field and laboratory measurements of OSC , using several such techniques, constrain the chemical properties of the organics and demonstrate that the formation and evolution of organic aerosol involves simultaneous changes to both carbon oxidation state and carbon number (nC).

  19. Oxidation state analyses of uranium with emphasis on chemical speciation in geological media

    International Nuclear Information System (INIS)

    Ervanne, H.

    2004-01-01

    This thesis focuses on chemical methods suitable for the determination of uranium redox species in geological materials. Nd-coprecipitation method was studied for the determination of uranium oxidation states in ground waters. This method is ideally suited for the separation of uranium oxidation states in the field, which means that problems associated with the instability of U(IV) during transport are avoided. An alternative method, such as ion exchange, is recommended for the analysis of high saline and calcium- and iron-rich ground waters. U(IV)/Utot was 2.8-7.2% in ground waters in oxidizing conditions and 60-93% in anoxic conditions. From thermodynamic model calculations applied to results from anoxic ground waters it was concluded that uranium can act as redox buffer in granitic ground waters. An ion exchange method was developed for the analysis of uranium oxidation states in different solid materials of geological origin. These included uranium minerals, uraniumbearing minerals, fracture coatings and bulk rock. U(IV)/Utot was 50-70% in uraninites, 5.8-8.7% in secondary uranium minerals, 15-49% in different fracture coatings and 64- 77% in samples from deep bedrock. In the uranium-bearing minerals, U(IV)/Utot was 33-43% (allanites), 5.9% (fergusonite) and 93% (monazite). Although the ion exchange method gave reliable results, there is a risk for the conversion of uranium oxidation states during analysis of heterogeneous samples due to the redox reactions that take place in the presence of some iron compounds. This risk was investigated in a study of several common iron-bearing minerals. The risk for conversion of uranium oxidation states can be screened by sample selection and minimized with use of a redox buffer compound such as polyacrylic acid (PAA). In studies of several carboxylic acids, PAA was found to be the most suitable for extending the application of the method. The stability of uranium oxidation states during analysis and the selectivity

  20. Effects of Vanadium Ions in Different Oxidation States on Myosin ATPase Extracted from the Solitary Ascidian, Halocynthia roretzi (Drasche) : Biochemistry

    OpenAIRE

    HITOSHI, MICHIBATA; YUTAKA, ZENKO; KENJI, YAMADA; MASATO, HASEGAWA; TATSURO, TERADA; TAKAHARU, NUMAKUANI; Biological Institute, Faculty of Science, Toyama University; Biological Institute, Faculty of Science, Toyama University; Biological Institute, Faculty of Science, Toyama University; Biological Institute, Faculty of Science, Toyama University; Department of Chemistry, Toyama College of Technology; Marine Biological Station, Tohoku University

    1989-01-01

    Some ascidians are known to accumulate vanadium ion within their tissues by 10^6-fold as that in sea water and store the metal ion in its reduced tetravalent and/or trivalent states. It is also well known that phosphoenzymes are inhibited by pentavalent vanadium ion over a range of 10nM to 1mM. In the present experiment we have therefore examined the effects of vanadium ions in different oxidation states on the activity of myosin ATPase extracted from the mantle of the ascidian, Halocynthia r...

  1. Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

    International Nuclear Information System (INIS)

    Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

    1990-08-01

    This report presents estimates of monthly sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program's Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment

  2. Oxidation mechanisms occurring in wines

    OpenAIRE

    Oliveira, Carla Maria; Ferreira, António César Silva; Freitas, Victor De; Silva, Artur M. S.

    2011-01-01

    The present review aims to show the state of the art on the oxidation mechanisms occurring in wines, as well as the methods to monitor, classify and diagnose wine oxidation. Wine oxidation can be divided in enzymatic oxidation and non-enzymatic oxidation. Enzymatic oxidation almost entirely occurs in grape must and is largely correlated with the content of hydroxycinnamates, such as caffeoyltartaric acid and paracoumaroyltartaric acid, and flavan-3-ols. Non-enzymatic oxidation, al...

  3. The present status of the synchrotron radiation laboratory of the institute for solid state physics

    International Nuclear Information System (INIS)

    Ishii, Takehiko; Miyahara, Yoshikazu; Suga, Shigemasa; Kakizaki, Akito

    1988-01-01

    The SOR-ring was initially designed so as to do steady operation at 300 MeV, but at present, it is used by injecting electrons at 308 MeV, and thereafter, accelerating to 380 MeV. The beam transport system carrying electrons from an electron synchrotron as the injector to the SOR-ring and the arrangement of the SOR-ring proper are shown. The action of the electron synchrotron and the SOR-ring is outlined. There are eight deflecting electromagnets and four sets of quadrupole electromagnets in the SOR-ring. The length of the straight parts is 1.3 m, and a high frequency accelerating cavity is placed in one of the straight parts, while exhaust pumps are installed in other parts. The arrangement of the electromagnets and the action of various equipments are explained. There are five beam lines in the SOR-ring. The way of using these beam lines is described. The research using the SOR-ring is classified into the research on the state of electrons in solids, the research on the state of electrons by optical reaction, absorption and light emission, the effect of vacuum ultraviolet irradiation to living things, and the research on beam dynamics in the ring. The mode of operation is explained. (Kako, I.)

  4. The past, present, and future of manatees in the southeastern United States: realities, misunderstandings and enigmas

    Science.gov (United States)

    O'Shea, T.J.

    1988-01-01

    A review of the historical and recent (1970s-1980s) literature on the distribution, abundance, and mortality of West Indian manatees (Trichechus manatus) in the southern United States is presented. Recent unpublished data on mortality, Florida boat registrations, size of certain manatee wintering populations, and records outside of Florida are also given. Manatees never regularly occurred outside of Florida, except during the summer in Georgia. Current distribution is also limited largely to Florida and coastal Georgia in summer, with extralimital records in other southeastern states. In winter the range contracts and is centered around warm water sources in Florida. The historical record on past abundance is inconclusive, but does not provide any compelling evidence to claim that manatees ever nearly became extinct. There are no satisfactory means to estimate manatee population size. However, within Florida, manatees have become more widespread and possibly more abundant during the past 30 years due to protection, greater availability of warm water in winter, and in some areas, increased exotic vegetation. Deliberate killing for food was long a historical pressure on manatee populations in Florida, but is not almost non-existent. Nevertheless, recent increasing trends in accidental mortality caused by boats, coupled with an understanding of manatee population dynamics, suggests that the future for manatees is not secure. Ample justification exists for continued manatee conservation efforts.

  5. Groundwater governance in Asia: present state and barriers to implementation of good governance

    Science.gov (United States)

    Tanaka, T.

    2014-09-01

    The present state of groundwater governance in Asia was reviewed. The main problem regarding groundwater resources in each Asian country is overexploitation, causing water level decline, land subsidence and salt water intrusion. For those groundwater hazards, many countries have established regulations such as laws and regulations as countermeasures. However, those laws and regulations are not the basic laws on groundwater resources, but only for countermeasures to prevent groundwater hazards. Common problems and barriers for implementing groundwater governance in Asian countries are that there is more than one institute with different and sometimes overlapping responsibilities in groundwater management. To overcome those conflicts among institutions and establishment of good governance, it is necessary to establish an agency in the government as one coordinate function reinforcing the direct coordination and facilitation of groundwater policy-making and management. As one such framework, the conceptual law called the Water Cycle Basic Law, which is under planning in Japan, is examined in this paper.

  6. Oxidation State of Iron in the Izu-Bonin Arc Initial Magma and Its Influence Factors

    Science.gov (United States)

    Li, H.; Arculus, R. J.; Brandl, P. A.; Hamada, M.; Savov, I. P.; Zhu, S.; Hickey-Vargas, R.; Tepley, F. J., III; Meffre, S.; Yogodzinski, G. M.; McCarthy, A.; Barth, A. P.; Kanayama, K.; Kusano, Y.; Sun, W.

    2014-12-01

    The redox state of mantle-derived magmas is a controversial issue, especially whether island arc basalts are more oxidized than those from mid-ocean ridges. Usually, arc magmas have higher Fe3+/Fe2+ and calculated oxygen fugacity (fO2) than mid-ocean ridge basalts (MORB). It is the high fO2 of arc magma that apparently delays onset of sulfide fractionation and sequestration of precious/base metals thereby facilitating the formation of many giant gold-copper deposits typically associated with subduction zones. But due to a paucity of Fe3+/Fe2+ data for primary mantle-derived arc magmas, the cause for high fO2 of these magma types is still controversial; causes may include inter alia subduction-released oxidized material addition to the mantle wedge source of arc magma, partial melting of subducted slab, and redox changes occurring during ascent of the magma. Fortunately, IODP expedition 351 drilling at IODP Site U1438 in the Amami-Sankaku Basin of the northwestern Philipine Sea, adjacent to the proto-Izu-Bonin Arc at the Kyushu-Palau Ridge (KPR), recovered not only volcaniclastics derived from the inception of Izu-Bonin Mariana (IBM) arc in the Eocene, but also similar materials for the Arc's subsequent evolution through to the Late Oligocene and abandonment of the KPR as a remnant arc. Samples of the pre-Arc oceanic crustal basement were also recovered enabling us to determine the fO2of the mantle preceding arc inception. As the oxidation state of iron in basaltic glass directly relates to the fO2 , the Fe3+/∑Fe ratio [Fe3+/(Fe3++ Fe2+)] of basaltic glass are quantified by synchrotron-facilitated micro X-ray Absorption Near Edge Structure (XANES) spectroscopy to reflect its fO2. Fe K-edge µ-XANES spectra were recorded in fluorescence mode at Beamline 15U1, Shanghai Synchrotron Radiation Facility (SSRF). Synthetic silicate glass with known Fe3+/∑Fe ratio was used in data handling. The experimental results as well as preliminary data from IODP Expedition 351

  7. The Impact of Environmental Factors in Influencing Epigenetics Related to Oxidative States in the Cardiovascular System

    Directory of Open Access Journals (Sweden)

    Francesco Angelini

    2017-01-01

    Full Text Available Oxidative states exert a significant influence on a wide range of biological and molecular processes and functions. When their balance is shifted towards enhanced amounts of free radicals, pathological phenomena can occur, as the generation of reactive oxygen species (ROS in tissue microenvironment or in the systemic circulation can be detrimental. Epidemic chronic diseases of western societies, such as cardiovascular disease, obesity, and diabetes correlate with the imbalance of redox homeostasis. Current advances in our understanding of epigenetics have revealed a parallel scenario showing the influence of oxidative stress as a major regulator of epigenetic gene regulation via modification of DNA methylation, histones, and microRNAs. This has provided both the biological link and a potential molecular explanation between oxidative stress and cardiovascular/metabolic phenomena. Accordingly, in this review, we will provide current insights on the physiological and pathological impact of changes in oxidative states on cardiovascular disorders, by specifically focusing on the influence of epigenetic regulation. A special emphasis will highlight the effect on epigenetic regulation of human’s current life habits, external and environmental factors, including food intake, tobacco, air pollution, and antioxidant-based approaches. Additionally, the strategy to quantify oxidative states in humans in order to determine which biological marker could best match a subject’s profile will be discussed.

  8. Influence of human papillomavirus on the clinical presentation of oropharyngeal carcinoma in the United States.

    Science.gov (United States)

    Stenmark, Matthew H; Shumway, Dean; Guo, Cui; Vainshtein, Jeffrey; Mierzwa, Michelle; Jagsi, Reshma; Griggs, Jennifer J; Banerjee, Mousumi

    2017-10-01

    Much of what is known about the significance of human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma is derived from single-institution retrospective studies, post hoc analyses of tissue specimens from clinical trials, and tissue bank studies with a small sample size. The objective of this study is to investigate the impact of HPV on the frequency and clinical presentation of oropharyngeal carcinoma in a large, national sample with information from patients who underwent HPV testing. Retrospective, cross-sectional study. We identified a comprehensive national sample of 8,359 patients with oropharyngeal carcinoma and known HPV status diagnosed between 2010 and 2011 within the National Cancer Database. Multivariable logistic regression was used to assess correlates of patient and tumor characteristics on HPV status. Among patients with oropharyngeal carcinoma, the frequency of HPV-related squamous cell carcinoma in the United States was 65.4%. HPV-related oropharyngeal carcinoma was associated with younger age, male sex, and white race (P presentation (P clinical profile, supporting efforts to re-evaluate the staging and treatment paradigm for HPV-associated oropharyngeal cancer. 4. Laryngoscope, 127:2270-2278, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  9. Present state and problems of the measures for securing stable supply of uranium resources

    International Nuclear Information System (INIS)

    Yoneda, Fumishige

    1982-01-01

    The long-term stable supply of uranium resources must be secured in order to accelerate the development and utilization of nuclear power in Japan. All uranium required in Japan is imported from foreign countries, and depends on small number of suppliers. On the use of uranium, various restrictions have been imposed by bilateral agreements from the viewpoint of nuclear non-proliferation policy. At present, the demand-supply relation in uranium market is not stringent, but in the latter half of 1980s, it is feared that it will be stringent. The prospect of the demand and supply of uranium resources, the state of securing uranium resources, the present policy on uranium resources, the necessity of establishing the new policy, and the active promotion of uranium resource measures are described. The measures to be taken are the promotion of exploration and development of mines, the participation in the management of such foreign projects, the promotion of diversifying the supply sources, the establishment of the structure to accept uranium resources, the promotion of the storage of uranium, and the rearrangement of general coordination and promotion functions for uranium resource procurement. (Kako, I.)

  10. Present state of inspection robot technology in nuclear power facilities. Case of fast breeder reactors

    International Nuclear Information System (INIS)

    Ara, Kuniaki

    1995-01-01

    In the maintenance works in nuclear power facilities such as checkup, inspection and repair, for the main purpose of radiation protection, remote operation technology was introduced since relatively early stage, and at present, the robots that carry out the inspection works for confirming the soundness of main equipment have been developed and put to practical use. At the time of introducing these technologies, in addition to the research and development of robots proper, the coordination with the design of plant machinery and equipment facilities as the premise of introducing robots is an important requirement. In this report, the present state of the development of remote inspection technology for fast breeder reactors is introduced, and the matters to which attention is paid in the plant design for introducing robots are explained. First, fast breeder reactors are described. The needs of robotizing and adopting remote operation in nuclear power facilities are explained, using the examples of the inspection system for a reactor vessel and the inspection system for steam generator heat transfer tubes. (K.I.)

  11. Oxidation states of Fe in LaNi1-xFexO3

    International Nuclear Information System (INIS)

    Goeta, A.E.; Falcon, H.; Carbonio, R.

    1994-01-01

    The distribution of oxidation states in perovskites of the type LaA 1-x B x O 3 (A and B transition metal ions) can be ''tailored'' by x variation. In particular, in LaNiO 3 it has been shown that Fe substitution for Ni foces some Ni 3+ into Ni 2+ , while some Fe 3+ changes into the unusual Fe 4+ state. In addition, the existence of mixed oxidation states of Fe and/or Ni in LaNi 1-x Fe x O 3 has been related to its catalytic activity in hydrogen peroxide decomposition. The Fe 4+ population, obtained using Moessbauer spectroscopy, was found to be constant for all the analyzed annealing temperatures for x = 0.25 concentration, where the isomer shift difference for both states is the highest and the catalytic activity is maximum. (orig.)

  12. Facile solid-state synthesis of oxidation-resistant metal nanoparticles at ambient conditions

    Science.gov (United States)

    Lee, Kyu Hyung; Jung, Hyuk Joon; Lee, Ju Hee; Kim, Kyungtae; Lee, Byeongno; Nam, Dohyun; Kim, Chung Man; Jung, Myung-Hwa; Hur, Nam Hwi

    2018-05-01

    A simple and scalable method for the synthesis of metal nanoparticles in the solid-state was developed, which can produce nanoparticles in the absence of solvents. Nanoparticles of coinage metals were synthesized by grinding solid hydrazine and the metal precursors in their acetates and oxides at 25 °C. The silver and gold acetates converted completely within 6 min into Ag and Au nanoparticles, respectively, while complete conversion of the copper acetate to the Cu sub-micrometer particles took about 2 h. Metal oxide precursors were also converted into metal nanoparticles by grinding alone. The resulting particles exhibit distinctive crystalline lattice fringes, indicating the formation of highly crystalline phases. The Cu sub-micrometer particles are better resistant to oxidation and exhibit higher conductivity compared to conventional Cu nanoparticles. This solid-state method was also applied for the synthesis of platinum group metals and intermetallic Cu3Au, which can be further extended to synthesize other metal nanoparticles.

  13. The present status and development of the state's system of safeguards in Japan

    International Nuclear Information System (INIS)

    Kurihara, H.; Haginoya, T.; Natsume, H.; Hirata, M.

    1977-01-01

    This paper summarizes developmental activities aiming at improving, the status of the Japan's System of safeguards. The integral tests are described which are now being implemented by the Japanese Government to check the effectiveness of the State's System, which must be maintained by the Government under the Safeguards Agreement between Japan and the IAEA under the Treaty on Non-Proliferation of Nuclear Weapons, ratified by Japan in June 1976. A joint experiment has been now implemented by the Nuclear Safety Bureau and the NMCC for knowing and improving the precision and accuracy of analytical measurements used at the bulk-facilities. JAERI, is conducting various R and D work on its own, and through cooperation with NMCC, NSB etc. The authors describe the results of non-destructive γ-spectrometry for the development of isotopic correlation techniques, as well as for the identification, and also refer briefly to measurement methods using the Fast Critical Assembly in JAERI. Measurement methods used in the Pu-fabrication facility of the PNC, and the problem of spent fuels application of safeguards for the reprocessing plant are discussed. The accounting reports coming from Japanese facilities are processed by the computer at the NMCC, and converted into (a) the State's material balance, and (b) the formats to be sent to IAEA. The authors discuss the experience of such data-processing as well as the developmental works for analysing MUF. As a part of the integral test, the experiences concerning planning and performance of inspection are discussed. The present status and future plans of the system of national analytical laboratories are described

  14. How different oxidation states of crystalline myoglobin are influenced by X-rays.

    Science.gov (United States)

    Hersleth, Hans-Petter; Andersson, K Kristoffer

    2011-06-01

    X-ray induced radiation damage of protein crystals is well known to occur even at cryogenic temperatures. Redox active sites like metal sites seem especially vulnerable for these radiation-induced reductions. It is essential to know correctly the oxidation state of metal sites in protein crystal structures to be able to interpret the structure-function relation. Through previous structural studies, we have tried to characterise and understand the reactions between myoglobin and peroxides. These reaction intermediates are relevant because myoglobin is proposed to take part as scavenger of reactive oxygen species during oxidative stress, and because these intermediates are similar among the haem peroxidases and oxygenases. We have in our previous studies shown that these different myoglobin states are influenced by the X-rays used. In this study, we have in detail investigated the impact that X-rays have on these different oxidation states of myoglobin. An underlying goal has been to find a way to be able to determine mostly unreduced states. We have by using single-crystal light absorption spectroscopy found that the different oxidation states of myoglobin are to a different extent influenced by the X-rays (e.g. ferric Fe(III) myoglobin is faster reduced than ferryl Fe(IV)═O myoglobin). We observe that the higher oxidation states are not reduced to normal ferrous Fe(II) or ferric Fe(III) states, but end up in some intermediate and possibly artificial states. For ferric myoglobin, it seems that annealing of the radiation-induced/reduced state can reversibly more or less give the starting point (ferric myoglobin). Both scavengers and different dose-rates might influence to which extent the different states are affected by the X-rays. Our study shows that it is essential to do a time/dose monitoring of the influence X-rays have on each specific redox-state with spectroscopic techniques like single-crystal light absorption spectroscopy. This will determine to which

  15. Templated electrodeposition of Ag7NO11 nanowires with very high oxidation states of silver

    NARCIS (Netherlands)

    Rodijk, E.J.B.; Maijenburg, A.W.; Maas, M.G.; Blank, David H.A.; ten Elshof, Johan E.

    2011-01-01

    The templated electrodeposition of 200 nm diameter nanowires of the argentic oxynitrate Ag(Ag3O4)2NO3 phase is reported. Their high surface-to-volume ratio and the high average oxidation state of Ag make these wires promising candidates for nanoscale redox processes in which both a high volumetric

  16. Investigation of the oxidation states of Pu isotopes in a hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Lee, M.H. [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, P. O. Box 105, Yuseong, Daejeon 305-353 (Korea, Republic of)], E-mail: mhlee@kaeri.re.kr; Kim, J.Y.; Kim, W.H.; Jung, E.C.; Jee, K.Y. [Nuclear Chemistry Research Division, Korea Atomic Energy Research Institute, P. O. Box 105, Yuseong, Daejeon 305-353 (Korea, Republic of)

    2008-12-15

    The characteristics of the oxidation states of Pu in a hydrochloric acid solution were investigated and the results were applied to a separating of Pu isotopes from IAEA reference soils. The oxidation states of Pu(III) and Pu(IV) were prepared by adding hydroxylamine hydrochloride and sodium nitrite to a Pu stock solution, respectively. Also, the oxidation state of Pu(VI) was adjusted with concentrated HNO{sub 3} and HClO{sub 4}. The stability of the various oxidation states of plutonium in a HCl solution with elapsed time after preparation were found to be in the following order: Pu(III){approx}Pu(VI)>Pu(IV)>Pu(V). The chemical recoveries of Pu(IV) in a 9 M HCl solution with an anion exchange resin were similar to those of Pu(VI). This method for the determination of Pu isotopes with an anion exchange resin in a 9 M HCl medium was applied to IAEA reference soils where the activity concentrations of {sup 239,240}Pu and {sup 238}Pu in IAEA-375 and IAEA-326 were consistent with the reference values reported by the IAEA.

  17. Teaching the Properties of Chromium's Oxidation States with a Case Study Method

    Science.gov (United States)

    Ozdilek, Zehra

    2015-01-01

    The purpose of this study was to investigate how a mixed-method case study affects pre-service science teachers' awareness of hexavalent chromium pollution and content knowledge about the properties of chromium's different oxidation states. The study was conducted in Turkey with 55 sophomores during the fall semester of 2013-2014. The students…

  18. The Effect of Precursor Ligands and Oxidation State in the Synthesis of Bimetallic Nano-Alloys

    KAUST Repository

    LaGrow, Alec P.; Knudsen, Kristian; AlYami, Noktan; Anjum, Dalaver H.; Bakr, Osman

    2015-01-01

    of variables on the characteristics of bimetallic nanomaterials are not completely understood. In this study, we used a continuous-flow synthetic strategy to explore the effects of the ligands and the oxidation state of a metal precursor in a shape

  19. Regulation of Ca2+ release from mitochondria by the oxidation-reduction state of pyridine nucleotides

    Science.gov (United States)

    Lehninger, Albert L.; Vercesi, Anibal; Bababunmi, Enitan A.

    1978-01-01

    Mitochondria from normal rat liver and heart, and also Ehrlich tumor cells, respiring on succinate as energy source in the presence of rotenone (to prevent net electron flow to oxygen from the endogenous pyridine nucleotides), rapidly take up Ca2+ and retain it so long as the pyridine nucleotides are kept in the reduced state. When acetoacetate is added to bring the pyridine nucleotides into a more oxidized state, Ca2+ is released to the medium. A subsequent addition of a reductant of the pyridine nucleotides such as β-hydroxybutyrate, glutamate, or isocitrate causes reuptake of the released Ca2+. Successive cycles of Ca2+ release and uptake can be induced by shifting the redox state of the pyridine nucleotides to more oxidized and more reduced states, respectively. Similar observations were made when succinate oxidation was replaced as energy source by ascorbate oxidation or by the hydrolysis of ATP. These and other observations form the basis of a hypothesis for feedback regulation of Ca2+-dependent substrate- or energy-mobilizing enzymatic reactions by the uptake or release of mitochondrial Ca2+, mediated by the cytosolic phosphate potential and the ATP-dependent reduction of mitochondrial pyridine nucleotides by reversal of electron transport. Images PMID:25436

  20. Measurements of the oxidation state and concentration of plutonium in interstitial waters of the Irish Sea

    International Nuclear Information System (INIS)

    Nelson, D.M.; Lovett, M.B.

    1980-01-01

    The question of plutonium movement in interstitial waters resulting from diffusion along concentration gradients or from advective flow is addressed. The results of measurements of both the concentration and the oxidation state of plutonium in interstitial water collected from sediments near the Windscale discharge, in the solid phases of these sediments and in seawater and suspended solids collected at the coring locations are discussed

  1. High-Pressure Reactivity of Kr and F2—Stabilization of Krypton in the +4 Oxidation State

    Directory of Open Access Journals (Sweden)

    Dominik Kurzydłowski

    2017-10-01

    Full Text Available Since the synthesis of the first krypton compound, several other Kr-bearing connections have been obtained. However, in all of them krypton adopts the +2 oxidation state, in contrast to xenon which forms numerous compounds with an oxidation state as high as +8. Motivated by the possibility of thermodynamic stabilization of exotic compounds with the use of high pressure (exceeding 1 GPa = 10 kbar, we present here theoretical investigations into the chemistry of krypton and fluorine at such large compression. In particular we focus on krypton tetrafluoride, KrF4, a molecular crystal in which krypton forms short covalent bonds with neighboring fluorine atoms thus adopting the +4 oxidation state. We find that this hitherto unknown compound can be stabilized at pressures below 50 GPa. Our results indicate also that, at larger compressions, a multitude of other KrmFn fluorides should be stable, among them KrF which exhibits covalent Kr–Kr bonds. Our results set the stage for future high-pressure synthesis of novel krypton compounds.

  2. Sorption behaviour of well-defined oxidation states

    International Nuclear Information System (INIS)

    Allard, B.; Olofsson, U.; Torstenfelt, B.; Kipatsi, H.

    1983-05-01

    The sorption of the actinides Am(III), Th(IV), Np(V), Pa(V), U(VI) and Pu has been studied as a function of pH (2-12) for two nuclide concentrations (10 -7 -10 -9 M) (only one for Pa and U) in the systems Al 2 0 3 - 0.01 M NaCl0 4 and Si0 2 - 0.01 M NaCl0 4 . Distribution coefficients have been determined by a batch technique after various contact times (6h - 6w) at constant temperature (25degreeC) in systems equilibrated with air. The observed sorption behaviour indicates a predominantly physical adsorption mechanism, where pH of the aqueous phase is the principal chemical parameter of influence. The sorption is highly related to the degree of hydrolysis, with a maximum in the pH-region where neutral species dominate and with a reduction of the sorption under conditions when anionic species (hydroxides or carbonates) would exist in solution. This is particularly the case for U(VI) at pH above 7-8 when anionic carbonate complexes would be formed. Plutonium is predominantly tetravalent under the present conditions, as indicated by the sorption behaviour. (authors)

  3. Heterogeneous Oxidation of Atmospheric Organic Aerosol: Kinetics of Changes to the Amount and Oxidation State of Particle-Phase Organic Carbon.

    Science.gov (United States)

    Kroll, Jesse H; Lim, Christopher Y; Kessler, Sean H; Wilson, Kevin R

    2015-11-05

    Atmospheric oxidation reactions are known to affect the chemical composition of organic aerosol (OA) particles over timescales of several days, but the details of such oxidative aging reactions are poorly understood. In this study we examine the rates and products of a key class of aging reaction, the heterogeneous oxidation of particle-phase organic species by the gas-phase hydroxyl radical (OH). We compile and reanalyze a number of previous studies from our laboratories involving the oxidation of single-component organic particles. All kinetic and product data are described on a common basis, enabling a straightforward comparison among different chemical systems and experimental conditions. Oxidation chemistry is described in terms of changes to key ensemble properties of the OA, rather than to its detailed molecular composition, focusing on two quantities in particular, the amount and the oxidation state of the particle-phase carbon. Heterogeneous oxidation increases the oxidation state of particulate carbon, with the rate of increase determined by the detailed chemical mechanism. At the same time, the amount of particle-phase carbon decreases with oxidation, due to fragmentation (C-C scission) reactions that form small, volatile products that escape to the gas phase. In contrast to the oxidation state increase, the rate of carbon loss is nearly uniform among most systems studied. Extrapolation of these results to atmospheric conditions indicates that heterogeneous oxidation can have a substantial effect on the amount and composition of atmospheric OA over timescales of several days, a prediction that is broadly in line with available measurements of OA evolution over such long timescales. In particular, 3-13% of particle-phase carbon is lost to the gas phase after one week of heterogeneous oxidation. Our results indicate that oxidative aging represents an important sink for particulate organic carbon, and more generally that fragmentation reactions play a major

  4. Evaluating Fire Risk in the Northeastern United States in the Past, Present, and Future

    Science.gov (United States)

    Miller, D.; Bradley, R. S.

    2017-12-01

    One poorly understood consequence of climate change is its effects on extreme events such as wildfires. Robust associations between wildfire frequency and climatic variability have been shown to exist, indicating that future climate change may continue to have a significant effect on wildfire activity. The Northeastern United States (NEUS) has seen some of the most infamous and largest historic fires in North America, such as the Miramichi Fire of 1825 and the fires of 1947. Although return intervals for large fires in the NEUS are long (hundreds of years), wildfires have played a critical role in ecosystem development and forest structure in the region. Understanding and predicting fire occurrence and vulnerability in the NEUS, especially in a changing climate, is economically and culturally important yet remains difficult due to human impacts (i.e. fire suppression activities and human disturbance). Thus, an alternative method for investigating fire risk in the NEUS is needed. Here, we present a compilation of meteorological data collected from Automated Surface Observing Systems (ASOS) from the NEUS throughout the 20th century through present day. We use these data to compute fifteen common "fire danger indices" employed in the USA and Canada to investigate changes in the region's fire risk over time, as well as the skill of each of these indices at predicting wildfire activity relative to the historical record of fires in the NEUS. We use dynamically-downscaled regional climate model output for the 21st century to project future wildfire activity based on the fire danger indices capable of capturing historical fire activity in the NEUS. These projections will aid in predicting how fire risk in the NEUS will evolve with anticipated climate change.

  5. Dispersion measurement on chirped mirrors at arbitrary incidence angle and polarization state (Conference Presentation)

    Science.gov (United States)

    Kovacs, Mate; Somoskoi, Tamas; Seres, Imre; Borzsonyi, Adam; Sipos, Aron; Osvay, Károly

    2017-05-01

    The optical elements of femtosecond high peak power lasers have to fulfill more and more strict requirements in order to support pulses with high intensity and broad spectrum. In most cases chirped pulse amplification scheme is used to generate high peak power ultrashort laser pulses, where a very precise control of spectral intensity and spectral phase is required in reaching transform-limited temporal shape at the output. In the case of few cycle regime, the conventional bulk glass, prism-, grating- and their combination based compressors are not sufficient anymore, due to undesirable nonlinear effects in their material and proneness to optical damages. The chirped mirrors are also commonly used to complete the compression after a beam transport system just before the target. Moreover, the manufacturing technology requires quality checks right after production and over the lifetime of the mirror as well, since undesired deposition on the surface can lead alteration from the designed value over a large part of the aperture. For the high harmonic generation, polarization gating technology is used to generate single attosecond pulses [1]. In this case the pulse to be compressed has various polarization state falling to the chirped mirrors. For this reason, it is crucial to measure the dispersion of the mirrors for the different polarization states. In this presentation we demonstrate a simple technique to measure the dispersion of arbitrary mirror at angles of incidence from 0 to 55 degree, even for a 12" optics. A large aperture 4" mirror has been scanned over with micrometer accuracy and the dispersion property through the surface has been investigated with a stable interference fringes in that robust geometry. We used Spectrally Resolved Interferometry, which is based on a Michaelson interferometer and a combined visible and infrared spectrometer. Tungsten halogen lamp with 10 mW coupled optical power was used as a white-light source so with the selected

  6. Present state of research and development of atomic energy in five Asian countries

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    The survey group for Asian atomic energy cooperation was dispatched by the Japanese government, and toured Philippines, Indonesia, Malaysia, Thailand and Bangladesh from September 7 to 19, 1980. The present state of atomic energy development and the energy situation in respective countries were surveyed through the exchange of opinion and the inspection of related facilities. The Regional Cooperative Agreement for Research, Development and Training Related to Nuclear Science and Technology was concluded in June, 1972, and 12 countries have participated in it. It was impressive that respective countries have the peculiar energy policies corresponding to their objective conditions. They regard atomic energy as the important substitute energy for petroleum, but the fear about the safety of atomic energy and the movement against nuclear power generation have been growing considerably. The research and development on atomic energy are carried out very actively in respective countries, and the construction of large-scale research centers was commenced in Indonesia, Malaysia and Bangladesh. Research reactors have been operated in Philippines, Indonesia and Thailand since about 20 years ago, and the utilization of radioisotopes and radiation has been studied. The cooperation of Japan with these countries is far behind that of other advanced countries.

  7. High Temperature Versus Geomechanical Parameters of Selected Rocks – The Present State of Research

    Directory of Open Access Journals (Sweden)

    Anna Sygała

    2013-01-01

    Full Text Available This paper presents the current state of knowledge concerning the examination of the impact of increased temperatures on changes of geomechanical properties of rocks. Based on historical data, the shape of stress–strain characteristics that illustrate the process of the destruction of rock samples as a result of load impact under uniaxial compression in a testing machine, were discussed. The results from the studies on changes in the basic strength and elasticity parameters of rocks, such as the compressive strength and Young’s modulus were compared. On their basis, it was found that temperature has a significant effect on the change of geomechanical properties of rocks. The nature of these changes also depends on other factors (apart from temperature. They are, among others: the mineral composition of rock, the porosity and density. The research analysis showed that changes in the rock by heating it at various temperatures and then uniaxially loading it in a testing machine, are different for different rock types. Most of the important processes that cause changes in the values of the strength parameters of the examined rocks occured in the temperature range of 400 to 600 °C.

  8. Present state and future trends of pine forests of malam jabba, swat district, Pakistan

    International Nuclear Information System (INIS)

    Siddiqui, M. F.; Arsalan, M.; Hussain, M. I.; Iqbal, J.; Wahab, M.

    2015-01-01

    Present state and future trend of pine forests of Malam Jabba, Swat district, Pakistan explored. We focused on vegetation composition, structure, diversity and forests dynamics. Thirteen stands were sampled by Point Centered Quarter method. Among all stands four monospecific forests of Pinus wallichiana attained highest density ha-1 except in one stand where Picea smithiana attained 401 trees ha-1. Unlike density, the basal area m2 ha-1 of these stands varies stand to stand. Based on floristic composition and importance value index, five different communities viz Pinus wallichiana-Picea smithiana; Picea smithiana-Pinus wallichiana; Abies pindrow-Pinus wallichiana; Pinus wallichiana-Abies pindrow; Abies pindrow-Picea smithiana and 4 monospecific forests of Pinus wallichiana were recognized. Size class structure of forests showed marked influence of anthropogenic disturbance because not a single stand showed ideal regeneration pattern (inverse J shape distribution). Future of these forests is worst due to absence trees in small size classes. Gaps are also evident in most of the forest stands. Stand diversity, richness, equitability and Simpson dominance values formulated on single stand basis. Diversity of Abides pindrow and Pinus wallichiana stand was highest because these stand occupied dominant species, while lowest diversity observed in some Pinus wallichiana and Picea smithiana stand as these stands have mark difference between the dominance of two species. In the monospecific forests, the diversity level was zero, suggesting the monopolization of resources by one species or elimination of other tree species in these stands. (author)

  9. The oxidation state of Fe in glasses from the Kerguelen Large Igneous Province: Evidence for the changing oxidation state of the Indian Ocean Basin

    Science.gov (United States)

    Peterson, M. E.; Stolper, E.; Brounce, M. N.; Eiler, J. M.; Wallace, P. J.

    2017-12-01

    Oxygen fugacity (ƒO2) is a thermodynamic property of silicate magmas that can be influenced by volcanic processes such as melting, crystal fractionation, and degassing. Lavas erupted as part of large igneous provinces (LIPs) may reflect the impingement of mantle plumes on the lithosphere, and thus could provide constraints on the ƒO2 of plumes responsible for generation of LIPs. The Kerguelen plateau was emplaced during the break up of Gondwana and the initial opening of the Indian Ocean. Elevated 207Pb/204Pb and 208Pb/204Pb ratios at low 206Pb/204Pb suggests that continental lithosphere from Gondwana is present in the asthenosphere of this region. The Sr-Nd-Pb-He isotopic compositions of the Kerguelen lavas are variable and have been used to infer that the mantle sources of these lavas reflect contributions from the depleted upper mantle, a common plume component, and the EM1 mantle component (perhaps recycled lower continental crust; e.g. Frey et al., 2002). The ƒO2 of the lavas of the Kerguelen LIP may thus reflect mixing of the upper mantle (i.e., near QFM), the plume component, and continental crust. We present new μ-XANES measurements of Fe3+/ΣFe ratios in a suite of 21 submarine glasses from Kerguelen. Over a narrow range in MgO (6.5-7.5 wt%), these glasses have Fe3+/ΣFe ratios of 0.16-0.18, corresponding to an ƒO2 of QFM+0.23 to +0.38 (at 1 atm, 1200°C). The H2O/Ce and Cl/K ratios of these glasses suggest that they did not assimilate significant amounts of altered oceanic crust. Also, S-FeOT variations indicate that the magmas are near sulfide saturation. These lavas were erupted in 1000 m of water, precluding significant loss of S to a vapor phase. At a given MgO content, samples from Kerguelen have similar to higher Fe3+/ΣFe ratios than the average values found in samples from along the Indian mid-ocean ridge, which could indicate a more oxidized mantle source. In addition, increases in Fe3+/ΣFe ratios of the Kerguelen samples, over a narrow

  10. Estimates of Present and Future Flood Risk in the Conterminous United States

    Science.gov (United States)

    Wing, O.; Bates, P. D.; Smith, A.; Sampson, C. C.; Johnson, K.; Fargione, J.; Morefield, P.

    2017-12-01

    Past attempts to estimate flood risk across the USA either have incomplete coverage, coarse resolution or use overly simplified models of the flooding process. In this paper, we use a new 30m resolution model of the entire conterminous US (CONUS) with realistic flood physics to produce estimates of flood hazard which match to within 90% accuracy the skill of local models built with detailed data. Socio-economic data of commensurate resolution are combined with these flood depths to estimate current and future flood risk. Future population and land-use projections from the US Environmental Protection Agency (USEPA) are employed to indicate how flood risk might change through the 21st Century, while present-day estimates utilize the Federal Emergency Management Agency (FEMA) National Structure Inventory and a USEPA map of population distribution. Our data show that the total CONUS population currently exposed to serious flooding is 2.6 to 3.1 times higher than previous estimates; with nearly 41 million Americans living within the so-called 1 in 100-year (1% annual probability) floodplain, compared to only 13 million according to FEMA flood maps. Moreover, socio-economic change alone leads to significant future increases in flood exposure and risk, even before climate change impacts are accounted for. The share of the population living on the 1 in 100-year floodplain is projected to increase from 13.3% in the present-day to 15.6 - 15.8% in 2050 and 16.4 - 16.8% in 2100. The area of developed land within this floodplain, currently at 150,000 km2, is likely to increase by 37 - 72% in 2100 based on the scenarios selected. 5.5 trillion worth of assets currently lie on the 1% floodplain; we project that by 2100 this number will exceed 10 trillion. With this detailed spatial information on present-day flood risk, federal and state agencies can take appropriate action to mitigate losses. Use of USEPA population and land-use projections mean that particular attention can be

  11. Recreational Nitrous Oxide Abuse-Induced Vitamin B12 Deficiency in a Patient Presenting with Hyperpigmentation of the Skin

    Directory of Open Access Journals (Sweden)

    Tsung-Ta Chiang

    2013-06-01

    Full Text Available Vitamin B12 deficiency causes skin hyperpigmentation, subacute combined degeneration of the spinal cord, and megaloblastic anemia. Although vitamin B12 deficiency rarely occurs in well-nourished, healthy, young people, nitrous oxide (N2O intoxication is an important cause of vitamin B12 deficiency in this cohort. N2O, a colorless gas used as an anesthetic since the late 19th century because of its euphoric and analgesic qualities, is now used as a recreational drug and is available via the Internet and at clubs. Here, we describe the case of a 29-year-old woman presenting with skin hyperpigmentation as her only initial symptom after N2O abuse for approximately 2 years. N2O intoxication-induced vitamin B12 deficiency was diagnosed based on the skin pigmentation that had manifested over the dorsa of her fingers, toes, and trunk, coupled with myeloneuropathy of the posterior and lateral columns, a low serum vitamin B12 level, an elevated serum homocysteine level, and the N2O exposure revealed while establishing the patient's history. Symptoms improved significantly with vitamin B12 treatment. We recommend that dermatologists consider N2O intoxication-induced vitamin B12 deficiency as a potential cause of skin hyperpigmentation and myeloneuropathy of the posterior and lateral columns in young, otherwise healthy patients. Failure to recognize this presentation may result in inappropriate treatment, thus affecting patients' clinical outcomes.

  12. Application of advanced oxidation process by electron beam irradiation in the organic compounds degradation present in industrial effluents

    International Nuclear Information System (INIS)

    Duarte, Celina Lopes

    1999-01-01

    The inefficacy of conventional methods to destroy toxic organic compounds present in industrial effluent has taken the search for new technologies of treatment. he water irradiation is the most efficient process to generate radicals that mineralise these compounds. A study to evaluate the Advanced Oxidation Process by electron beam irradiation to treat industrial effluent with high toxic organic compounds concentration was carried out. Experiments were conducted using a Radiation Dynamics Electron Beam Accelerator with 1,5 MeV energy and 37 power. The effluent samples from a big industrial complex were irradiated using the IPEN's Liquid Effluent Irradiation Pilot Plant and the effluent samples from five steps of a Governmental Wastewater Treatment Plant from SABESP - ETE Suzano (industrial Receiver Unit, Coarse Bar Screens, Medium Bar Screens, Primary Sedimentation and Final Effluent), were irradiated in a batch system. The electron beam irradiation showed be efficient on destroying the organic compounds delivered in these effluents mainly chloroform, dichloroethane, methyl isobutyl ketone, benzene, toluene, xylene, phenol and in the decoloring of dyes present in some samples. To remove 90% of the most organic compounds was necessary a 20 kGy dose for industry's ETE, 20 kGy for IRU, CBS and MBS and 10 kGy to 20 kGy for PS and FE. (author)

  13. Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen

    International Nuclear Information System (INIS)

    Sallis, S.; Williams, D. S.; Butler, K. T.; Walsh, A.; Quackenbush, N. F.; Junda, M.; Podraza, N. J.; Fischer, D. A.; Woicik, J. C.; White, B. E.; Piper, L. F. J.

    2014-01-01

    The origin of the deep subgap states in amorphous indium gallium zinc oxide (a-IGZO), whether intrinsic to the amorphous structure or not, has serious implications for the development of p-type transparent amorphous oxide semiconductors. We report that the deep subgap feature in a-IGZO originates from local variations in the oxygen coordination and not from oxygen vacancies. This is shown by the positive correlation between oxygen composition and subgap intensity as observed with X-ray photoelectron spectroscopy. We also demonstrate that the subgap feature is not intrinsic to the amorphous phase because the deep subgap feature can be removed by low-temperature annealing in a reducing environment. Atomistic calculations of a-IGZO reveal that the subgap state originates from certain oxygen environments associated with the disorder. Specifically, the subgap states originate from oxygen environments with a lower coordination number and/or a larger metal-oxygen separation.

  14. Origin of deep subgap states in amorphous indium gallium zinc oxide: Chemically disordered coordination of oxygen

    Energy Technology Data Exchange (ETDEWEB)

    Sallis, S.; Williams, D. S. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States); Butler, K. T.; Walsh, A. [Center for Sustainable Technologies and Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY (United Kingdom); Quackenbush, N. F. [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Junda, M.; Podraza, N. J. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Fischer, D. A.; Woicik, J. C. [Materials Science and Engineering Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); White, B. E.; Piper, L. F. J., E-mail: lpiper@binghamton.edu [Department of Physics, Applied Physics, and Astronomy, Binghamton University, Binghamton, New York 13902 (United States); Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

    2014-06-09

    The origin of the deep subgap states in amorphous indium gallium zinc oxide (a-IGZO), whether intrinsic to the amorphous structure or not, has serious implications for the development of p-type transparent amorphous oxide semiconductors. We report that the deep subgap feature in a-IGZO originates from local variations in the oxygen coordination and not from oxygen vacancies. This is shown by the positive correlation between oxygen composition and subgap intensity as observed with X-ray photoelectron spectroscopy. We also demonstrate that the subgap feature is not intrinsic to the amorphous phase because the deep subgap feature can be removed by low-temperature annealing in a reducing environment. Atomistic calculations of a-IGZO reveal that the subgap state originates from certain oxygen environments associated with the disorder. Specifically, the subgap states originate from oxygen environments with a lower coordination number and/or a larger metal-oxygen separation.

  15. Structural oxidation state studies of the manganese cluster in the oxygen evolving complex of photosystem II

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Wenchuan [Univ. of California, Berkeley, CA (United States)

    1994-11-01

    X-ray absorption spectroscopy (XAS) was performed on Photosystem II (PSII)-enriched membranes prepared from spinach to explore: (1) the correlation between structure and magnetic spin state of the Mn cluster in the oxygen evolving complex (OEC) in the S2 state; and (2) the oxidation state changes of the Mn cluster in the flash-induced S-states. The structure of the Mn cluster in the S2 state with the g~4 electron paramagnetic resonance (EPR) signal (S2-g4 state) was compared with that in the S2 state with multiline signal (S2-MLS state) and the S1 state. The S2-g4 state has a higher XAS inflection point energy than that of the S1 state, indicating the oxidation of Mn in the advance from the S1 to the S2-g4 state. Differences in the edge shape and in the extended X-ray absorption fine structure (EXAFS) show that the structure of the Mn cluster in the S2-g4 state is different from that in the S2-MLS or the S1 state. In the S2-g4 state, the second shell of backscatterers from the Mn absorber contains two Mn-Mn distances of 2.73 Å and 2.85 Å. Very little distance disorder exists in the second shell of the S1 or S2-MLS states. The third shell of the S2-g4 state at about 3.3 Å also contains increased heterogeneity relative to that of the S2-MLS or the S1 state. Various S-states were prepared at room-temperature by saturating, single-turnover flashes. The flash-dependent oscillation in the amplitude of the MLS was used to characterize the S-state composition and to construct "pure" S-state Mn K-edge spectra. The edge position shifts to higher energy by 1.8 eV upon the S1 → S2 transition.

  16. Control of anode supported SOFCs (solid oxide fuel cells): Part I. mathematical modeling and state estimation within one cell

    International Nuclear Information System (INIS)

    Amedi, Hamid Reza; Bazooyar, Bahamin; Pishvaie, Mahmoud Reza

    2015-01-01

    In this paper, a 3-dimensional mathematical model for one cell of an anode-supported SOFC (solid oxide fuel cells) is presented. The model is derived from the partial differential equations representing the conservation laws of ionic and electronic charges, mass, energy, and momentum. The model is implemented to fully characterize the steady state operation of the cell with countercurrent flow pattern of fuel and air. The model is also used for the comparison of countercurrent with concurrent flow patterns in terms of thermal stress (temperature distribution) and quality of operation (current density). Results reveal that the steady-state cell performance curve and output of simulations qualitatively match experimental data of the literature. Results also demonstrate that countercurrent flow pattern leads to an even distribution of temperature, more uniform current density along the cell and thus is more enduring and superior to the concurrent flow pattern. Afterward, the thorough 3-dimensional model is used for state estimation instead of a real cell. To estimate states, the model is simplified and changed to a 1-dimensional model along flow streams. This simplified model includes uncertainty (because of simplifying assumptions of the model), noise, and disturbance (because of measurements). The behaviors of extended and ensemble Kalman filter as an observer are evaluated in terms of estimating the states and filtering the noises. Results demonstrate that, like extended Kalman filter, ensemble Kalman filter properly estimates the states with 20 sets. - Highlights: • A 3-dimensional model for one cell of SOFC (solid oxide fuel cells) is presented. • Higher voltages and thermal stress in countercurrent than concurrent flow pattern. • State estimation of the cell is examined by ensemble and extended Kalman filters. • Ensemble with 20 sets is as good as extended Kalman filter.

  17. Non steady-state model for dry oxidation of nuclear wastes metallic containers in long term interim storage conditions

    International Nuclear Information System (INIS)

    Bertrand, Nathalie; Desgranges, Clara; Poquillon, Dominique; Monceau, Daniel

    2006-01-01

    For high-level nuclear waste containers in long-term interim storage, dry oxidation will be the first and the main degradation mode. The reason is that, for this kind of waste, the temperature on the surface of the containers will be high enough to avoid any condensation phenomena for several years. Even if the scale growth kinetics is expected to be very slow since the temperature will be moderate at the beginning of the storage (around 300 deg. C) and will keep on decreasing, the metal thickness lost by dry oxidation over such a long period must be evaluated with a good reliability. To achieve this goal, modelling of the oxide scale growth is necessary and this is the aim of the dry oxidation studies, performed in the frame of the COCON programme. All existing oxidation models are based on the two main oxidation theories developed by Wagner between the 1930's and 1970's on the one hand, and by Cabrera and Mott in the 1960 and next by Fromhold on the other hand. These used to be associated with high temperature behaviour for Wagner's theory and with low temperature for the second one. Indeed it is certainly more relevant to consider their range of application in terms of the oxide scale thickness rather than in terms of temperature. The question is posed about which theory should an appropriate model rely on. It can be expected that the oxide scale could have a thickness ranging from a few tens of nanometers up to several tens of micrometers depending on temperature and class of alloys chosen. At the present time, low-alloyed steels or carbon steels are considered candidate materials for high-level nuclear waste containers in long term interim storage. For this type of alloys, the scale formed during the dry oxidation stage will be 'rapidly' thick enough to neglect the Mott field. Hence, in a first step, some basic models based on a parabolic rate assumption, that is to say Wagner's model, have been derived from experimental data on iron and on low-alloy steel

  18. Correlation of the oxidation state of cerium in sol-gel glasses as a function of thermal treatment via optical spectroscopy and XANES studies.

    Science.gov (United States)

    Assefa, Zerihun; Haire, R G; Caulder, D L; Shuh, D K

    2004-07-01

    Sol-gel glass matrices containing lanthanides have numerous technological applications and their formation involves several chemical facets. In the case of cerium, its ability to exist in two different oxidation states or in mixed valence state provides additional complexities for the sol-gel process. The oxidation state of cerium present during different facets of preparation of sol-gel glasses, and also as a function of the starting oxidation state of cerium added, were studied both by optical spectroscopy and X-ray absorption near-edge structures (XANES). The findings acquired by each approach were compared. The primary focus was on the redox chemistries associated with sample preparation, gelation, and thermal treatment. When Ce3+ is introduced into the starting sols, the trivalent state normally prevails in the wet and room temperature-dried gels. Heating in air at >100 degrees C can generate a light yellow coloration with partial oxidation to the tetravalent state. Above 200 degrees C and up to approximately 1000 degrees C, cerium is oxidized to its tetravalent state. In contrast, when tetravalent cerium is introduced into the sol, both the wet and room temperature-dried gels lose the yellow-brown color of the initial ceric ammonium nitrate solution. When the sol-gel is heated to 110 degrees C it turns yellowish as the cerium tends to be re-oxidized. The yellow color is believed to represent the effect of oxidation and oligomerization of the cerium-silanol units in the matrix. The luminescence properties are also affected by these changes, the details of which are reported herein.

  19. Extracellular redox state: refining the definition of oxidative stress in aging.

    Science.gov (United States)

    Jones, Dean P

    2006-01-01

    Oxidative stress in aging can result from an imbalance of prooxidants and antioxidants with excessive, destructive free radical chemistry. Thiol systems are important in the control of these processes, both by protecting against damage and serving in redox signaling mechanisms to sense danger and repair the damage. Studies by a number of research groups in collaboration with the Emory Clinical Biomarkers Laboratory show that the redox state of the central tissue antioxidant, glutathione (GSH), can be measured in human plasma and provides a quantitative systemic indicator of oxidative stress. Plasma GSH/GSSG redox in humans becomes oxidized with age, in response to chemotherapy, as a consequence of cigarette smoking, and in association with common age-related diseases (e.g., type 2 diabetes, cardiovascular disease). However, the GSH/GSSG redox is not equilibrated with the larger plasma cysteine/cystine (Cys/CySS) pool, and the Cys/CySS redox varies with age in a pattern that is distinct from that of GSH/GSSG redox. Furthermore, in vitro studies show that variation in Cys/CySS redox over the range found in vivo affects signaling pathways, which control cell proliferation and oxidant-induced apoptosis. The results point to the conclusion that free radical scavenging antioxidants are of increased importance when thiol/disulfide redox states are oxidized. Because thiol/disulfide redox states, per se, function in redox signaling and control as well as antioxidant protection, GSH/GSSG and Cys/CySS redox states may provide central parameters to link environmental influences and progression of changes associated with aging.

  20. DETERMINATION OF THE PRESENT VEGETATION STATE OF A WETLAND WITH UAV RGB IMAGERY

    Directory of Open Access Journals (Sweden)

    M. A. Boon

    2017-11-01

    Full Text Available The compositional and structural characteristics of wetland vegetation play a vital role in the services that a wetland supplies. Apart from being important habitats, wetland vegetation also provide services such as flood attenuation and nutrient retention. South Africa is known to be a water scarce country. The protection and continuous monitoring of wetland ecosystems is therefore important. Factors such as site transformation and disturbance may completely change the vegetation of a wetland and the use of Unmanned Aerial Vehicle (UAV imagery can play a valuable role in high-resolution monitoring and mapping. This study assessed if the use of UAV RGB imagery can enhance the determination of the present vegetation state of a wetland. The WET-Health level two (detailed on-site evaluation methodology was followed for the vegetation assessment, where wetland health is a measure of the deviation of a wetland’s structure and function from its natural reference condition. The mapping of the disturbances classes was then undertaken using ultra-high resolution orthophotos, point clouds and digital surface models (DSM. The WET-Health vegetation module completed with the aid of the UAV products still indicates that the vegetation of the wetland is largely modified (“D” PES Category and that the vegetation of the wetland will further deteriorate (change score. These results are the same as determined in the baseline study. However a higher impact (activities taking place within the wetland score were determined. The assessment of various WET-Health vegetation indicators were significantly enhanced using the UAV imagery and derived products. The UAV products provided an accurate vantage point over the wetland and surroundings, and assisted to easily refine the assessment of the disturbance classes and disturbance units.

  1. Pediatric martial arts injuries presenting to Emergency Departments, United States 1990-2003.

    Science.gov (United States)

    Yard, Ellen E; Knox, Christy L; Smith, Gary A; Comstock, R Dawn

    2007-08-01

    Although an estimated 6.5 million United States (US) children aged 6-17 practiced a martial art in 2004, there have been no nationally representative studies comparing pediatric injuries among the three most popular disciplines, karate, taekwondo, and judo. Describe pediatric martial arts injuries presenting to a representative sample of US Emergency Departments (EDs) from 1990 to 2003. We reviewed all martial arts injuries captured by the US Consumer Product Safety Commission's (CPSC), National Electronic Injury Surveillance System (NEISS). An estimated 128,400 children injuries from 1990 to 2003. Injured tended to be male (73.0%) and had a mean age of 12.1 years. Most injuries were attributed to karate (79.5%). The most common mechanism of injury was being kicked (25.6%), followed by falling (20.6%) and kicking (18.0%). The majority of injuries occurred to the lower leg/foot/ankle (30.1%) and hand/wrist (24.5%). The most common injury diagnoses were sprains/strains (29.3%), contusions/abrasions (27.8%), and fractures (24.6%). Participants in judo sustained significantly higher proportions of shoulder/upper arm injuries than karate (IPR=4.31, 95% CI: 2.84-6.55) or taekwondo (IPR=9.75, 95% CI: 3.53-26.91) participants. There were also higher proportions of neck injuries sustained by judo participants compared to karate (IPR=4.73, 95% CI: 1.91-11.70) or taekwondo (IPR=4.17, 95% CI: 1.02-17.06) participants. Pediatric martial arts injuries differ by discipline. Understanding these injury patterns can assist with the development of discipline-specific preventive interventions.

  2. Estado actual de la cirugia general laparoscópica Present state of videolaparascopic surgery

    Directory of Open Access Journals (Sweden)

    Carlos Hernándo Morales Uribe

    1994-04-01

    Full Text Available

    Los procedimientos laparoscópicos han empezado a reemplazar algunas operaciones
    convencionales porque evitan la cirugía mayor y se logra una recuperación precoz del paciente. En el futuro muchas cirugías tradicionales se realizarán laparoscópicamente. En este artículo se presenta el estado actual de la cirugía laparoscópica en los siguientes casos: cirugía biliar, úlcera péptica, corrección del reflujo gastroesofágico
    y de algunos trastornos motores esofágicos, abdomen agudo, herniorrafia inguinal
    y cirugía colorrectal. Se consignan las ventajas y desventajas en general y para cada
    caso en particular.
    Laparascopic pracedures have begun to replace the conventional ones in arder to
    avoid major surgery and to allow an earlier recovery of the patlent. In thls article the
    present state of laparoscopic surgery is revlewed, concernlng the followlng entities:
    blliary surgery, peptlc ulcer, correction of gastroesophageal reflux and of esophageal
    motility problems, acute abdomen, ingulnal herniorrhaphy and colorectal surgery. Advantages and dlsadvantages are consldered both in general and for each speclflc case. 

  3. Shaping the American Educational State--1900 to the Present. Urgent Issues in American Society Series.

    Science.gov (United States)

    Karier, Clarence J., Ed.

    In this historical study the author provides a critical interpretation of selected movements that have shaped the educational state in America during the 20th century. Two questions provide the thematic structure of the book. The first question concerns the role, function, and responsibility of the professional in the educational state; the second…

  4. Signatures of Quantized Energy States in Solution-Processed Ultrathin Layers of Metal-Oxide Semiconductors and Their Devices

    KAUST Repository

    Labram, John G.

    2015-02-13

    Physical phenomena such as energy quantization have to-date been overlooked in solution-processed inorganic semiconducting layers, owing to heterogeneity in layer thickness uniformity unlike some of their vacuum-deposited counterparts. Recent reports of the growth of uniform, ultrathin (<5 nm) metal-oxide semiconductors from solution, however, have potentially opened the door to such phenomena manifesting themselves. Here, a theoretical framework is developed for energy quantization in inorganic semiconductor layers with appreciable surface roughness, as compared to the mean layer thickness, and present experimental evidence of the existence of quantized energy states in spin-cast layers of zinc oxide (ZnO). As-grown ZnO layers are found to be remarkably continuous and uniform with controllable thicknesses in the range 2-24 nm and exhibit a characteristic widening of the energy bandgap with reducing thickness in agreement with theoretical predictions. Using sequentially spin-cast layers of ZnO as the bulk semiconductor and quantum well materials, and gallium oxide or organic self-assembled monolayers as the barrier materials, two terminal electronic devices are demonstrated, the current-voltage characteristics of which resemble closely those of double-barrier resonant-tunneling diodes. As-fabricated all-oxide/hybrid devices exhibit a characteristic negative-differential conductance region with peak-to-valley ratios in the range 2-7.

  5. Example of uranium(IV) insertion within a macrocyclic crown ether with coexistence of the metal in two oxidation states

    Energy Technology Data Exchange (ETDEWEB)

    Bombieri, G; De Paoli, G [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi; Immirzi, A

    1978-01-01

    Reaction of UCl/sub 4/ with 18-crown-6 in tetrahydrofuran yields (UCl/sub 4/)/sub 3/ (18-crown-6)/sub 2/ which on recrystallization in nitromethane, gives a partially oxidized and hydrolyzed product whose structure has been investigated by X-ray diffraction. The compound crystallizes in the orthorhombic system. The cell contains eight UCl/sub 3//sup +/ cations each inserted within a crown molecule and four (UO/sub 2/Cl/sub 3/(OH)(H/sub 2/O))/sup 2 -/anions having a pentagonal bipyramidal structure. Four solvated nitromethane molecules are also present. The compound represents one of the very few examples in which uranium exists in two oxidation states, and the first example in which its insertion within a crown macrocycle has been proved by an X-ray diffraction study.

  6. Chromium Oxidation State in Planetary Basalts: Oxygen Fugacity Indicator and Critical Variable for Cr-Spinel Stability

    Science.gov (United States)

    Bell, A. S.; Burger, P. V.; Le, Loan; Papike, J. J.; Jone, J.; Shearer, C. K.

    2014-01-01

    Cr is a ubiquitous and relatively abundant minor element in basaltic, planetary magmas. At the reduced oxidation states (present in melts as both divalent and trivalent forms. The ratio of trivalent to divalent Cr present in the melt has many consequences for the stability and Cr concentration of magmatic phases such as spinel, clinopyroxene, and olivine. However, understanding the Cr valence in quenched melts has historically been plagued with analytical issues, and only recently has reliable methodology for quantifying Cr valence in quenched melts been developed. Despite this substantial difficulty, the pioneering works of Hanson and Jones and Berry and O'Neill provided important insights into the oxidation state of Cr in in silicate melts. Here we present a series of 1-bar gas mixing experiments performed with a Fe-rich basaltic melt in which have determined the Cr redox ratio of the melt at over a range of fO2 values by measuring this quantity in olivine with X-ray Absorption Near Edge Spectroscopy (XANES). The measured Cr redox ratio of the olivine phenocrysts can be readily converted to the ratio present in the conjugate melt via the ratio of crystal-liquid partition coefficients for Cr3+ and Cr2+. We have applied these results to modeling Cr spinel stability and Cr redox ratios in a primitive, iron-rich martian basalt.

  7. 3 and 4 oxidation state element solubilities in borosilicate glasses. Implement to actinides in nuclear glasses

    International Nuclear Information System (INIS)

    Cachia, J.N.

    2005-12-01

    In order to ensure optimal radionuclides containment, the knowledge of the actinide loading limits in nuclear waste glasses and also the comprehension of the solubilization mechanisms of these elements are essential. A first part of this manuscript deals with the study of the differences in solubility of the tri and tetravalent elements (actinides and surrogates) particularly in function of the melting temperature. The results obtained indicate that trivalent elements (La, Gd, Nd, Am, Cm) exhibit a higher solubility than tetravalent elements (Hf, Th, Pu). Consequently, it was planned to reduce plutonium at the oxidation state (III), the later being essentially tetravalent in borosilicate glasses. An innovating reduction process of multi-valent elements (cerium, plutonium) using silicon nitride has been developed in a second part of this work. Reduced plutonium-bearing glasses synthesized by Si 3 N 4 addition made it possible to double the plutonium solubility from 2 to 4 wt% at 1200 deg C. A structural approach to investigate the differences between tri and tetravalent elements was finally undertaken. These investigations were carried out by X-rays Absorption Spectroscopy (EXAFS) and NMR. Trivalent rare earth and actinide elements seem to behave as network modifiers while tetravalent elements rather present true intermediaries' behaviour. (author)

  8. General regularity of the oxidation potential variations and high oxidation states in the second half of the actinide series

    International Nuclear Information System (INIS)

    Spitsyn, V.I.; Vokhmin, V.G.; Ionova, G.V.; Pershina, V.G.

    1984-01-01

    Oxidation potentials (OP) PHI(4/3), PHI(5/3), PHI(6/3), PHI(5/4) and PHI(6/5) are calculated for the members of the actinide series. A semiemperic relation combining OP with explicit terms for ground level energies of actinide ions in Russell-Saunders approximation as well as known values of formal OP relative to the normal hydrogen electrode potential are used as an extrapolation function. It is shown that an increase of PHI(4/3) OP which occurs after Bsub(k) explains a low stability of the oxidation state 4 in solutions for actinides of the second half of the series. PHI(5/3) and PHI(5/4) OP in the section starting with Cm have the minimum at Cf. PHI(6/3) OP for Cm, Bk, Cf and Es are practically the same but for Cm, Bk and Es they are smaller than PHI(5/3) OP. A principle possibility of Bk(6), Cf(6) and Es(6) preparation is shown

  9. In situ oxidation state profiling of nickel hexacyanoferrate derivatized electrodes using line-imaging Raman spectroscopy and multivariate calibration

    International Nuclear Information System (INIS)

    Haight, S.M.; Schwartz, D.T.

    1999-01-01

    Metal hexacyanoferrate compounds show promise as electrochemically switchable ion exchange materials for use in the cleanup of radioactive wastes such as those found in storage basins and underground tanks at the Department of Energy's Hanford Nuclear Reservation. Reported is the use of line-imaging Raman spectroscopy for the in situ determination of oxidation state profiles in nickel hexacyanoferrate derivatized electrodes under potential control in an electrochemical cell. Line-imaging Raman spectroscopy is used to collect 256 contiguous Raman spectra every ∼5 microm from thin films (ca. 80 nm) formed by electrochemical derivatization of nickel electrodes. The cyanide stretching region of the Raman spectrum of the film is shown to be sensitive to iron oxidation state and is modeled by both univariate and multivariate correlations. Although both correlations fit the calibration set well, the multivariate (principle component regression or PCR) model's predictions of oxidation state are less sensitive to noise in the spectrum, yielding a much smoother oxidation state profile than the univariate model. Oxidation state profiles with spatial resolution of approximately 5 microm are shown for a nickel hexacyanoferrate derivatized electrode in reduced, intermediate, and oxidized states. In situ oxidation state profiles indicate that the 647.1 nm laser illumination photo-oxidizes the derivatized electrodes. This observation is confirmed using photoelectrochemical methods

  10. Enhanced catalytic hydrogenation activity of Ni/reduced graphene oxide nanocomposite prepared by a solid-state method

    Science.gov (United States)

    Li, Yizhao; Cao, Yali; Jia, Dianzeng

    2018-01-01

    A simple solid-state method has been applied to synthesize Ni/reduced graphene oxide (Ni/rGO) nanocomposite under ambient condition. Ni nanoparticles with size of 10-30 nm supported on reduced graphene oxide (rGO) nanosheets are obtained through one-pot solid-state co-reduction among nickel chloride, graphene oxide, and sodium borohydride. The Ni/rGO nanohybrid shows enhanced catalytic activity toward the reduction of p-nitrophenol (PNP) into p-aminophenol compared with Ni nanoparticles. The results of kinetic research display that the pseudo-first-order rate constant for hydrogenation reaction of PNP with Ni/rGO nanocomposite is 7.66 × 10-3 s-1, which is higher than that of Ni nanoparticles (4.48 × 10-3 s-1). It also presents superior turnover frequency (TOF, 5.36 h-1) and lower activation energy ( E a, 29.65 kJ mol-1) in the hydrogenation of PNP with Ni/rGO nanocomposite. Furthermore, composite catalyst can be magnetically separated and reused for five cycles. The large surface area and high electron transfer property of rGO support are beneficial for good catalytic performance of Ni/rGO nanocomposite. Our study demonstrates a simple approach to fabricate metal-rGO heterogeneous nanostructures with advanced functions.

  11. Coupled interactions between volatile activity and Fe oxidation state during arc crustal processes

    Science.gov (United States)

    Humphreys, Madeleine C.S.; Brooker, R; Fraser, D.C.; Burgisser, A; Mangan, Margaret T.; McCammon, C

    2015-01-01

    Arc magmas erupted at the Earth’s surface are commonly more oxidized than those produced at mid-ocean ridges. Possible explanations for this high oxidation state are that the transfer of fluids during the subduction process results in direct oxidation of the sub-arc mantle wedge, or that oxidation is caused by the effect of later crustal processes, including protracted fractionation and degassing of volatile-rich magmas. This study sets out to investigate the effect of disequilibrium crustal processes that may involve coupled changes in H2O content and Fe oxidation state, by examining the degassing and hydration of sulphur-free rhyolites. We show that experimentally hydrated melts record strong increases in Fe3+/∑Fe with increasing H2O concentration as a result of changes in water activity. This is relevant for the passage of H2O-undersaturated melts from the deep crust towards shallow crustal storage regions, and raises the possibility that vertical variations in fO2 might develop within arc crust. Conversely, degassing experiments produce an increase in Fe3+/∑Fe with decreasing H2O concentration. In this case the oxidation is explained by loss of H2 as well as H2O into bubbles during decompression, consistent with thermodynamic modelling, and is relevant for magmas undergoing shallow degassing en route to the surface. We discuss these results in the context of the possible controls on fO2 during the generation, storage and ascent of magmas in arc settings, in particular considering the timescales of equilibration relative to observation as this affects the quality of the petrological record of magmatic fO2.

  12. Speciation of the oxidation states of plutonium in aqueous solutions by UV/Vis spectroscopy, CE-ICP-MS and CE-RIMS

    International Nuclear Information System (INIS)

    Buerger, S.; Banik, N.L.; Buda, R.A.; Kratz, J.V.; Kuczewski, B.; Trautmann, N.

    2007-01-01

    For the speciation of the plutonium oxidation states in aqueous solutions, the online coupling of capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Depending on the radius/electrical charge ratio, the oxidation states III, IV, V, and VI of plutonium are separated by CE, based on the different migration times through the capillary and are detected by ICP-MS. The detection limit is 20 ppb, i.e. 10 9 -10 10 atoms (10 -12 -10 -13 g) for one oxidation state with an uncertainty of the reproducibility of the migration times of ≤ 1% and ≤ 5% for the peak area. The redox kinetics of the different plutonium oxidation states in the presence of humic substances (humic and fulvic acid) have been studied. A relatively rapid reduction of Pu(VI) (10 to 1000 h) in contact with Gorleben fulvic or Aldrich humic acid could be observed, depending on the pH of the solution. Furthermore, at pH=1, a reduction to Pu(III) and Pu(IV) in a mixture of all four oxidation states in contact with Gorleben fulvic acid after one month has been observed. In order to improve the sensitivity of the CE method, the offline coupling of CE to resonance ionization mass spectrometry (RIMS) has been explored. First applications of this new speciation method are presented. (orig.)

  13. Radiation oxidation of polypropylene: A solid-state 13C NMR study using selective isotopic labeling

    International Nuclear Information System (INIS)

    Mowery, Daniel M.; Assink, Roger A.; Derzon, Dora K.; Klamo, Sara B.; Bernstein, Robert; Clough, Roger L.

    2007-01-01

    Polypropylene samples, in which the three different carbon atoms along the chain were selectively labeled with carbon-13, were subjected to radiation under inert and air atmospheres, and to post-irradiation exposure in air at various temperatures. By using solid-state 13 C NMR measurements at room temperature, we have been able to identify and quantify the oxidation products. The isotopic labeling provides insight into chemical reaction mechanisms, since oxidation products can be traced back to their positions of origin on the macromolecule. The major products include peroxides and alcohols, both formed at tertiary carbon sites along the chain. Other products include methyl ketones, acids, esters, peresters, and hemiketals formed from reaction at the tertiary carbon, together with in-chain ketones and esters from reaction at the secondary chain carbon. No evidence is found of products arising from reactions at the methyl side chain. Significant temperature-dependent differences are apparent; for example much higher yields of chain-end methyl ketones, which are the indicator product of chain scission, are generated for both elevated temperature irradiation and for post-irradiation treatment at elevated temperatures. Time-dependent plots of yields of the various oxidation products have been obtained under a wide range of conditions, including the post-irradiation oxidation of a sample at room temperature in air that has been monitored for 2 years. Radiation-oxidation products of polypropylene are contrasted to products measured for 13 C-labeled polyethylene in an earlier investigation: the peroxides formed in irradiated polypropylene are remarkably longer lived, the non-peroxidic products are significantly different, and the overall ratios of oxidation products in polypropylene change relatively little as a function of the extent of oxidation

  14. System Tb-Fe-O: thermodynamic properties of ternary oxides using solid-state electrochemical cells

    International Nuclear Information System (INIS)

    Rakshit, S.K.; Parida, S.C.; Dash, S.; Singh, Ziley; Prasad, R.; Venugopal, V.

    2003-01-01

    The standard molar Gibbs free energies of formation of TbFeO 3 (s) and Tb 3 Fe 5 O 12 (s) have been determined using solid-state electrochemical cell employing different solid electrolytes. The reversible emfs of the following solid-state electrochemical cells have been measured in the temperature range 1050≤T/K≤1250. Cell (I):(-)Pt/{TbFeO 3 (s)+Tb 2 O 3 (s)+Fe(s)}//YDT/CSZ//{Fe(s)+Fe 0.95 O(s)}/Pt(+))) (Cell (II):(-)Pt/{Fe(s)+Fe 0.95 O(s)}//CSZ//{TbFeO 3 (s)+Tb 3 Fe 5 O 12 (s)+Fe 3 O 4 (s)}/Pt(+) The oxygen chemical potentials corresponding to the three-phase equilibria involving the ternary oxides have been computed from the emf data. The standard molar Gibbs free energies of formation of solid TbFeO 3 and Tb 3 Fe 5 O 12 calculated by the least-squares regression analysis of the data obtained in the present study are given by {Δ f G compfn m (TbFeO 3 ,s)/(kJ·mol -1 )±3.2}=-1357.5+0.2531·(T/K); (1050≤T/K≤1548);))and({Δ f G compfn m (Tb 3 Fe 5 O 12 ,s)/(kJ·mol -1 )±3.5}=-4901.7+ 0.9997·(T/K); (1050≤T/K≤1250).)) The uncertainty estimates for Δ f G compfn m include the standard deviation in the emf and uncertainty in the data taken from the literature. Based on the thermodynamic information, oxygen potential diagram and chemical potential diagrams were computed for the system Tb-Fe-O at T=1250 K

  15. Microbial utilization of low molecular weight organic substrates in soil depends on their carbon oxidation state

    Science.gov (United States)

    Gunina, Anna; Smith, Andrew; Jones, Davey; Kuzyakov, Yakov

    2017-04-01

    Removal of low molecular weight organic substances (LMWOS), originating from plants and microorganisms, from soil solution is regulated by microbial uptake. In addition to the concentration of LMWOS in soil solution, the chemical properties of each substance (e.g. C oxidation state, number of C atoms, number of -COOH groups) can affect their uptake and subsequent partitioning of C within the soil microbial community. The aim of this study was to trace the initial fate of three dominant classes of LMWOS in soil (sugars, carboxylic and amino acids), including their removal from solution and utilization by microorganisms, and to reveal the effect of substance chemical properties on these processes. Soil solution, spiked at natural abundance levels with 14C-labelled glucose, fructose, malate, succinate, formate, alanine or glycine, was added to the soil and 14C was traced in the dissolved organic carbon (DOC), CO2, cytosol and soil organic carbon (SOC) over 24 hours. The half-life time of all LMWOS in the DOC (T1 /2-solution) varied between 0.6-5.0 min showing extremely fast initial uptake of LMWOS. The T1 /2-solution of substances was dependent on C oxidation state, indicating that less oxidized organic substances (with C oxidation state "0") were retained longer in soil solution than oxidized substances. The LMWOS-C T1 /2-fast, characterizing the half-life time of 14C in the fast mineralization pool, ranged between 30 and 80 min, with the T1 /2-fast of carboxylic acids (malic acid) being the fastest and the T1 /2-fast of amino acids (glycine) being the slowest. An absence of correlation between T1 /2-fast and either C oxidation state, number of C atoms, or number of -COOH groups suggests that intercellular metabolic pathways are more important for LMWOS transformation in soil than their basic chemical properties. The CO2 release during LMWOS mineralization accounted for 20-90% of 14C applied. Mineralization of LMWOS was the least for sugars and the greatest for

  16. Influence of steam generator surface state on corrosion and oxide formation

    International Nuclear Information System (INIS)

    Mazenc, Arnaud; Leclercq, Stephanie; Seyeux, Antoine; Galtayries, Anouk; Marcus, Philippe

    2012-09-01

    The corrosion and release of nickel-based alloy Steam Generator tubes are partly due to their surface state. Among the most important parameters influencing the corrosion, the effect of grain size and the effect of grain crystallographic orientation have been chosen to be studied. The aim of this study is to determine how these parameters have an impact on the corrosion of Steam Generator tubes. Thermal treatments (700 deg. C and 1050 deg. C) have been performed on several samples in Alloy 690 to obtain homogeneous grain sizes, varying from 25 μm to 110 μm. Two samples have been oxidised for four days in a recirculating autoclave, reproducing primary conditions. The changes of oxide composition and thickness were examined by ToF-SIMS on samples exposed to primary water conditions. The intensity profiles versus thicknesses of characteristic oxide anions, such as CrO - , NiO - or FeO - enable us to evaluate the effect of grain size and crystallographic orientation on the formation of an enriched inner chromium layer. As regards to the grain size, there was no effect on the growth, but smaller grains led to a chromium-rich oxide layer. The effect of crystallographic orientation was observed on the oxidation kinetics and the composition of oxide scales. (authors)

  17. Characterization of Interface State in Silicon Carbide Metal Oxide Semiconductor Capacitors

    Science.gov (United States)

    Kao, Wei-Chieh

    Silicon carbide (SiC) has always been considered as an excellent material for high temperature and high power devices. Since SiC is the only compound semiconductor whose native oxide is silicon dioxide (SiO2), it puts SiC in a unique position. Although SiC metal oxide semiconductor (MOS) technology has made significant progress in recent years, there are still a number of issues to be overcome before more commercial SiC devices can enter the market. The prevailing issues surrounding SiC MOSFET devices are the low channel mobility, the low quality of the oxide layer and the high interface state density at the SiC/SiO2 interface. Consequently, there is a need for research to be performed in order to have a better understanding of the factors causing the poor SiC/SiO2 interface properties. In this work, we investigated the generation lifetime in SiC materials by using the pulsed metal oxide semiconductor (MOS) capacitor method and measured the interface state density distribution at the SiC/SiO2 interface by using the conductance measurement and the high-low frequency capacitance technique. These measurement techniques have been performed on n-type and p-type SiC MOS capacitors. In the course of our investigation, we observed fast interface states at semiconductor-dielectric interfaces in SiC MOS capacitors that underwent three different interface passivation processes, such states were detected in the nitrided samples but not observed in PSG-passivated samples. This result indicate that the lack of fast states at PSG-passivated interface is one of the main reasons for higher channel mobility in PSG MOSFETs. In addition, the effect of mobile ions in the oxide on the response time of interface states has been investigated. In the last chapter we propose additional methods of investigation that can help elucidate the origin of the particular interface states, enabling a more complete understanding of the SiC/SiO2 material system.

  18. Electrode-Impregnable and Cross-Linkable Poly(ethylene oxide)-Poly(propylene oxide)-Poly(ethylene oxide) Triblock Polymer Electrolytes with High Ionic Conductivity and a Large Voltage Window for Flexible Solid-State Supercapacitors.

    Science.gov (United States)

    Han, Jae Hee; Lee, Jang Yong; Suh, Dong Hack; Hong, Young Taik; Kim, Tae-Ho

    2017-10-04

    We present cross-linkable precursor-type gel polymer electrolytes (GPEs) that have large ionic liquid uptake capability, can easily penetrate electrodes, have high ion conductivity, and are mechanically strong as high-performance, flexible all-solid-state supercapacitors (SC). Our polymer precursors feature a hydrophilic-hydrophobic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock main-chain structure and trifunctional silane end groups that can be multi-cross-linked with each other through a sol-gel process. The cross-linked solid-state electrolyte film with moderate IL content (200 wt %) shows a well-balanced combination of excellent ionic conductivity (5.0 × 10 -3 S cm -1 ) and good mechanical stability (maximum strain = 194%). Moreover, our polymer electrolytes have various advantages including high thermal stability (decomposition temperature > 330 °C) and the capability to impregnate electrodes to form an excellent electrode-electrolyte interface due to the very low viscosity of the precursors. By assembling our GPE-impregnated electrodes and solid-state GPE film, we demonstrate an all-solid-state SC that can operate at 3 V and provides an improved specific capacitance (112.3 F g -1 at 0.1 A g -1 ), better rate capability (64% capacity retention until 20 A g -1 ), and excellent cycle stability (95% capacitance decay over 10 000 charge/discharge cycles) compared with those of a reference SC using a conventional PEO electrolyte. Finally, flexible SCs with a high energy density (22.6 W h kg -1 at 1 A g -1 ) and an excellent flexibility (>93% capacitance retention after 5000 bending cycles) can successfully be obtained.

  19. Solid state chemistry of rare earth oxides. Final report, September 1, 1950--July 31, 1977

    International Nuclear Information System (INIS)

    Eyring, L.

    1977-07-01

    Work under Contract E(11-1)-1109 and its antecedents has been primarily for the purpose of obtaining detailed thermodynamic, kinetic and structural information on the complex rare earth oxides of praseodymium and terbium. These systems exhibit homologous series of ordered phases, order-disorder transformations, wide-range nonstoichiometric phases, chemical hysteresis in two-phase regions and many other solid state reaction phenomena. Fluorite-related materials of importance to ERDA occur as nuclear fuels, radiation power sources, insulators and solid electrolytes. The rare earth oxides serve directly as model systems for such similar materials and, in a more general sense, they serve as models of solids in general since they exhibit nearly the full range of solid state properties

  20. Solid State Electrochemical Sensors for Nitrogen Oxide (NOx) Detection in Lean Exhaust Gases

    OpenAIRE

    Rheaume, Jonathan Michael

    2010-01-01

    Solid state electrochemical sensors that measure nitrogen oxides (NOx) in lean exhaust have been investigated in order to help meet future on-board diagnostic (OBD) regulations for diesel vehicles. This impedancemetric detection technology consists of a planar, single cell sensor design with various sensing electrode materials and yttria-stabilized zirconia (YSZ) as the electrolyte. No reference to ambient air is required. An impedance analysis method yields a signal that is proportional to t...

  1. Quantitative evaluation of the effect of H2O degassing on the oxidation state of magmas

    Science.gov (United States)

    Lange, R. A.; Waters, L.

    2014-12-01

    The extent to which degassing of the H2O component affects the oxidation state of hydrous magmas is widely debated. Several researchers have examined how degassing of mixed H-C-O-S-Cl fluids may change the Fe3+/FeT ratio of various magmas, whereas our focus is on the H2O component. There are two ways that degassing of H2O by itself may cause oxidation: (1) the reaction: H2O (melt) + 2FeO (melt) = H2 (fluid) + Fe2O3 (melt), and/or (2) if dissolved water preferentially enhances the activity of ferrous vs. ferric iron in magmatic liquids. In this study, a comparison is made between the pre-eruptive oxidation states of 14 crystal-poor, jet-black obsidian samples (obtained from two Fe-Ti oxides) and their post-eruptive values (analyzed with the Wilson 1960 titration method tested against USGS standards). The obsidians are from Medicine Lake (CA), Long Valley (CA), and the western Mexican arc; all have low FeOT (1.1-2.1 wt%), rendering their Fe2+/Fe3+ ratios highly sensitive to the possible effects of substantial H2O degassing. The Fe-Ti oxide thermometer/oxybarometer of Ghiorso and Evans, (2008) gave temperatures for the 14 samples that range for 720 to 940°C and ΔNNO values of -0.9 to +1.4. With temperature known, the plagioclase-liquid hygrometer was applied and show that ≤ 6.5 wt% H2O was dissolved in the melts prior to eruption. In addition, pre-eruptive Cl and S concentrations were constrained on the basis of apatite analyses (Webster et al., 2009) and sulfur concentrations needed for saturation with pyrrhotite (Clemente et al., 2004), respectively. Maximum pre-eruptive chlorine and sulfur contents are 6000 and 200 ppm, respectively. After eruption, the rhyolites lost nearly all of their volatiles. Our results indicate no detectable change between pre- and post-eruptive Fe2+ concentrations, with an average deviation of ± 0.1 wt % FeO. Although degassing of large concentrations of S and/or Cl may affect the oxidation state of magmas, at the pre-eruptive levels

  2. Present state and progress of industrial electron processing systems in Japan

    International Nuclear Information System (INIS)

    Sakamoto, I.; Mizusawa, K.

    1983-01-01

    A summary is given of the state of utilisation of electron processing systems in Japan, mainly for (1) cross-linking of wire and cable insulator, (2) heat shrinkable tube and sheet, (3) foamed polyethylene, and (4) curing of paint coats. Details are given of some of the electron processing systems. (U.K.)

  3. The Present State of the Business Law Education of Accounting Students: The Business Law Professor's Perspective

    Science.gov (United States)

    Kocakulah, Mehmet C.; Austill, A. David; Long, Brett

    2009-01-01

    The article aims to provide Certified Public Accountant (CPA) candidates, accounting faculty, the American Institute of Certified Public Accountants (AICPA), and the state boards of accountancy with an insight into the business law professor's perspective concerning the legal education of accountants. This article first describes various factors,…

  4. Is long distance free space quantum communication with the OAM state of light feasible [Presentation

    CSIR Research Space (South Africa)

    Hamadou Ibrahim, A

    2013-06-01

    Full Text Available -space quantum communication with the OAM state of light feasible? A. HAMADOU IBRAHIM1,2, F.S. ROUX1, M. McLAREN1,3 , A. FORBES1,2,3 & T. KONRAD2 1. CSIR National Laser Centre, PO Box 395, Pretoria 0001 2. School of Physics, University of Kwazulu...

  5. Arsenic (+3 oxidation state) methyltransferase and the inorganic arsenic methylation phenotype

    International Nuclear Information System (INIS)

    Li Jiaxin; Waters, Stephen B.; Drobna, Zuzana; Devesa, Vicenta; Styblo, Miroslav; Thomas, David J.

    2005-01-01

    Inorganic arsenic is enzymatically methylated; hence, its ingestion results in exposure to the parent compound and various methylated arsenicals. Both experimental and epidemiological evidences suggest that some of the adverse health effects associated with chronic exposure to inorganic arsenic may be mediated by these methylated metabolites. If i As methylation is an activation process, then the phenotype for inorganic arsenic methylation may determine risk associated with exposure to this metalloid. We examined inorganic arsenic methylation phenotypes and arsenic (+3 oxidation state) methyltransferase genotypes in four species: three that methylate inorganic arsenic (human (Homo sapiens), rat (Rattus norwegicus), and mouse (Mus musculus)) and one that does not methylate inorganic arsenic (chimpanzee, Pan troglodytes). The predicted protein products from arsenic (+3 oxidation state) methyltransferase are similar in size for rat (369 amino acid residues), mouse (376 residues), and human (375 residues). By comparison, a 275-nucleotide deletion beginning at nucleotide 612 in the chimpanzee gene sequence causes a frameshift that leads to a nonsense mutation for a premature stop codon after amino acid 205. The null phenotype for inorganic arsenic methylation in the chimpanzee is likely due to the deletion in the gene for arsenic (+3 oxidation state) methyltransferase that yields an inactive truncated protein. This lineage-specific loss of function caused by the deletion event must have occurred in the Pan lineage after Homo-Pan divergence about 5 million years ago

  6. Oxidation-state distribution of plutonium in surface and subsurface waters at Thule, northwest Greenland

    International Nuclear Information System (INIS)

    McMahon, C.A.; Leon Vintro, L.; Mitchell, P.I.; Dahlgaard, H.

    2000-01-01

    The speciation of plutonium in Arctic waters sampled on the northwest Greenland shelf in August 1997 is discussed in this paper. Specifically, we report the results of analyses carried out on seawater sampled (a) close to the Thule air base where, in 1968, a US military aircraft carrying four nuclear weapons crashed on sea ice, releasing kilogram quantities of plutonium to the snow pack and underlying seabed sediments, and (b) at a reference station (Upernavik) located ∼400 km to the south. The data show that most of the plutonium in the dissolved phase at Thule is in the form of Pu(V, VI) (mean: 68±6%; n=6), with little if any distinction apparent between surface and bottom waters. Further, the oxidation state distribution at stations close to the accident site is similar to that measured at Upernavik, remote from this site. It is also similar to the distribution observed in shelf waters at mid-latitudes, suggesting that the underlying processes controlling plutonium speciation are insensitive to temperature over the range 0-25 deg. C. Measurements using tangential-flow ultrafiltration indicate that virtually all of the plutonium (including the fraction in a reduced chemical form) is present as fully dissolved species. Most of this plutonium would seem to be of weapons fallout origin, as the mean 238 Pu/ 239,240 Pu activity ratio in the water column (dissolved phase) at Thule (0.06±0.02; n=10) is similar to the global fallout ratio at this latitude (∼0.04). Thus, there is little evidence of weapons-grade plutonium in the water column at Thule at the present time

  7. Single Crystal Growth of Pure Co3+ Oxidation State Material LaSrCoO4

    Directory of Open Access Journals (Sweden)

    Hanjie Guo

    2016-08-01

    Full Text Available We report on the single crystal growth of the single-layer perovskite cobaltate LaSrCoO4 that was grown by the optical floating zone method using high oxygen pressures. Phase purity and single crystallinity were confirmed by X-ray diffraction techniques. The pure Co3+ oxidation state was confirmed by X-ray absorbtion spectroscopy measurements. A transition to a spin glass state is observed at ∼7 K in magnetic susceptibility and specific heat measurements.

  8. Regulating incentives: the past and present role of the state in health care systems.

    Science.gov (United States)

    Saltman, Richard B

    2002-06-01

    The desire of national policymakers to encourage entrepreneurial behavior in the health sector has generated not only a new structure of market-oriented incentives, but also a new regulatory role for the State. To ensure that entrepreneurial behavior will be directed toward achieving planned market objectives, the State must shift modalities from staid bureaucratic models of command-and-control to more sensitive and sophisticated systems of oversight and supervision. Available evidence suggests that this structural transformation is currently occurring in several Northern European countries. Successful implementation of that shift will require a new, intensive, and expensive strategy for human resources development, raising questions about the financial feasibility of this incentives-plus-regulation model for less-well-off CEE/CIS and developing countries.

  9. Molecular water oxidation mechanisms followed by transition metals: state of the art.

    Science.gov (United States)

    Sala, Xavier; Maji, Somnath; Bofill, Roger; García-Antón, Jordi; Escriche, Lluís; Llobet, Antoni

    2014-02-18

    One clean alternative to fossil fuels would be to split water using sunlight. However, to achieve this goal, researchers still need to fully understand and control several key chemical reactions. One of them is the catalytic oxidation of water to molecular oxygen, which also occurs at the oxygen evolving center of photosystem II in green plants and algae. Despite its importance for biology and renewable energy, the mechanism of this reaction is not fully understood. Transition metal water oxidation catalysts in homogeneous media offer a superb platform for researchers to investigate and extract the crucial information to describe the different steps involved in this complex reaction accurately. The mechanistic information extracted at a molecular level allows researchers to understand both the factors that govern this reaction and the ones that derail the system to cause decomposition. As a result, rugged and efficient water oxidation catalysts with potential technological applications can be developed. In this Account, we discuss the current mechanistic understanding of the water oxidation reaction catalyzed by transition metals in the homogeneous phase, based on work developed in our laboratories and complemented by research from other groups. Rather than reviewing all of the catalysts described to date, we focus systematically on the several key elements and their rationale from molecules studied in homogeneous media. We organize these catalysts based on how the crucial oxygen-oxygen bond step takes place, whether via a water nucleophilic attack or via the interaction of two M-O units, rather than based on the nuclearity of the water oxidation catalysts. Furthermore we have used DFT methodology to characterize key intermediates and transition states. The combination of both theory and experiments has allowed us to get a complete view of the water oxidation cycle for the different catalysts studied. Finally, we also describe the various deactivation pathways for

  10. 1944 Water Treaty Between Mexico and the United States: Present Situation and Future Potential

    Directory of Open Access Journals (Sweden)

    Anabel Sánchez

    2006-01-01

    Full Text Available Historically and culturally, water has always been considered to be a critical issue in Mexico- USA agenda. Along the 3 140-km border between Mexico and the United States, there is intense competition over the adequate availability of water. Water uses in urban border areas have continued to increase exponentially due to steadily increasing levels of population growth. Rapid industrialisation and urbanisation have resulted in more intensive patterns of water consumption and use. Agricultural water demands continue to be high. Mexico and the United States have established institutions and agreements to manage and protect rivers in the border region. The Treaty between Mexico and the United States for the Utilisation of Waters of the Colorado and Tijuana Rivers and of the Rio Grande was signed in 1944. With the turn of the century, the growing urban centers along the Rio Grande (Rio Bravo, where the river becomes the international boundary, started increasingly to depend on groundwater. This situation was not specifically addressed in the 1944 Treaty, especially as groundwater use at that time was not so significant.

  11. Methane oxidation with low O2/CH4 ratios in the present of water: Combustion or reforming

    International Nuclear Information System (INIS)

    Geng, Haojie; Yang, Zhongqing; Zhang, Li; Ran, Jingyu; Yan, Yunfei

    2017-01-01

    Highlights: • Copper catalyst displays an inhibitory effect of water while cobalt catalyst does not. • Both catalysts show their catalytic ability for oxidation and reforming reaction. • Oxidation precedes reforming in methane reaction over both catalysts. • Water participates in reforming reaction and shows increasing effect in high temperature. - Abstract: This paper investigates the reaction of methane over copper and cobalt catalysts under oxygen-deficient conditions with added water. A fixed-bed reactor, TPD analysis, in situ DRIFTS study, and temperature detection were used to test the activity of the methane reaction, water adsorption on the metal surface, OH group behavior, and the endothermic and exothermic processes of the reaction. The results show that the inhibitory effect of water mainly occurs at a low temperature and methane conversion decreases when water is introduced into the feed. Water easily adsorbs on metal clusters and forms OH groups at low temperatures. Copper tends to adsorb more water than cobalt and shows a stronger inhibitory effect. The DRIFTS spectra of the Cu catalyst show strong OH peaks during the reaction, of which the magnitudes increase with the water pressure. When the reaction temperature rises (750 °C), water begins to serve as an oxidant and participates in the reforming reaction. Both catalysts show a transition process between the oxidation and reforming reactions as the temperature increases. Co displays a better catalytic performance in the reforming reaction. Oxidation precedes reforming; water does not participate in the reaction if the oxygen is not fully consumed.

  12. Sulfur diffusion in dacitic melt at various oxidation states: Implications for volcanic degassing

    Science.gov (United States)

    Lierenfeld, Matthias Bernhard; Zajacz, Zoltán; Bachmann, Olivier; Ulmer, Peter

    2018-04-01

    The diffusivity of S in a hydrous dacitic melt (4.5-6.0 wt.% H2O) has been investigated in the temperature (T) and pressure (P) range of 950 °C to 1100 °C and 200 to 250 MPa, respectively. Three series of experiments were conducted at relatively low oxygen fugacity (fO2) conditions [0.8 log units below fayalite-magnetite-quartz equilibrium (FMQ -0.8); referred to as "low fO2"] and high fO2 conditions (FMQ +2.5; referred to as "high fO2") to determine if the diffusivity of S is affected by its oxidation state and speciation. Sulfur concentration profiles were measured by electron microprobe and the diffusion coefficient (D) was calculated by fitting these profiles. Sulfur diffusion is approximately one order of magnitude faster when S is dominantly present as sulfide species (low fO2) in comparison to the sulfate dominated experiments (high fO2). The following Arrhenian equations were obtained for high and low fO2 conditions at 200 MPa: high fO2: D = 10-5.92±0.86 * exp ({-137.3±21.5 kJ/mol}/{RT}) low fO2: D = 10-5.18±1.39 * exp ({-125.7±34.4 kJ/mol}/{RT}) where D is the average diffusion coefficient in m2 s-1, R is the gas constant in 8.3144 J mol-1 K-1 and T is the temperature in K. Our results demonstrate for the first time in natural melts that S diffusion is strongly sensitive to fO2. Our S diffusivities under low fO2 conditions are only slightly slower of those found for H2O, suggesting that S can be rather efficiently purged from reduced dacitic melts during volcanic eruptions. However, for more oxidized systems (e.g. subduction zones), S diffusion will be much slower and will hinder equilibrium syn-eruptive degassing during rapid decompression. Therefore, we conclude that the "excess" measured during many explosive volcanic eruptions in arcs is dominantly derived from S-rich bubble accumulation in the eruptible portion of the magma reservoir.

  13. Application of powerful oxidizers in the synthesis of new high-oxidation state actinide and related species

    International Nuclear Information System (INIS)

    Yeh, S.M.

    1984-11-01

    The fluorinating and oxide scavenging ability of XeF 6 have been studied by bringing XeF 6 into interaction with oxide-fluoride compounds of the third-transition-series elements (W, Re and Os) and uranium, in their highest oxidation states. A + MOF 5 - and A + M 2 O 2 F 9 - (A = K or Cs, M = W or U) were converted to A + MF 7 - by XeF 6 , but the rhenium and osmium compounds, K + ReO 2 F 4 - and XeF 5 + OsO 3 F 3 - , resisted interaction with XeF 6 . Strong interactions between XeF 2 or KrF 2 and the solvent have been observed for their solutions in anhydrous HF. Both XeF 2 and KrF 2 are seen to be effective in breaking up the polymeric (HF)/sub n/ chains. Only weak interactions occur between cations and anions of KrF + AuF 6 - and Kr 2 F 3 + AuF 6 - in HF. The AuF 6 - anions are slightly distorted from O/sub h/ symmetry. Kr 2 F 3 + cations in HF have the same dissymmetric V-shape which occurs in crystalline salts. A low-temperature orthorhombic form, β-ReF 6 + SbF 6 - , a high-temperature rhombohedral form, α-ReF 6 + SbF 6 - , and a ReF 6 + AuF 6 - have been prepared. These compounds possess only kinetic stability at ambient temperature and at approx. 20 0 C are best represented as ReF 6 + ReF 7 MF 6 - MF 5 . Thermochemical energy evaluations indicate that the ionization potential of ReF 6 is 261 kcal mole -1 and that the fluoride-ion affinity of ReF 6 + is -214 kcal mole -1 . This is more exothermal than the corresponding process for IF 6 + (-208 kcal mole -1 ). In contrast, ReOF 5 is shown to be a better fluoro-base than IOF 5 and also is a better base than ReF 7 . ReOF 4 + MF 6 - (M = Sb, Au and As) salts are of higher thermal stability than their ReF 6 + MF 6 - analogues

  14. Synchrotron Micro-XANES Measurements of Vanadium Oxidation State in Glasses as a Function of Oxygen Fugacity: Experimental Calibration of Data Relevant to Partition Coefficient Determination

    Science.gov (United States)

    Delaney, J. S.; Sutton, S. R.; Newville, M.; Jones, J. H.; Hanson, B.; Dyar, M. D.; Schreiber, H.

    2000-01-01

    Oxidation state microanalyses for V in glass have been made by calibrating XANES spectral features with optical spectroscopic measurements. The oxidation state change with fugacity of O2 will strongly influence partitioning results.

  15. Chemical state analysis of oxidation products on steel surface by conversion electron Moessbauer spectrometry

    International Nuclear Information System (INIS)

    Ujihira, Yusuke; Nomura, Kiyoshi

    1978-01-01

    The polished NT-70H steel (Fe: 95.97%, C: 0.56%, diameter: 5 cm, thickness: 0.5 cm) was immersed in deionized water or in solutions containing (0.25 -- 0.5) M of chloride, sulfate and nitrate ions. The chemical states of oxidation products of iron on the surface were identified through the analysis of conversion electron Moessbauer spectra (CEMS). CEMS of the steel surface, which had been dipped in deionized water, revealed that γ-FeOOH was formed on the surface. The thickness of γ-FeOOH layer increased with the increase of the duration of dipping. Dissolved oxygen in the solution played an essential role in the oxidation of iron to γ-FeOOH. Oxidation product of iron dipped in the 0.5 M sodium chloride solution was identified as γ-FeOOH. Amorphous paramagnetic iron (III) compound tended to form in the presence of hydrogen peroxide or ammonium ions in the solutions. The increase of alkalinity of the solution up to pH 12 suppressed the oxidation rate and assisted the formation of green rust, which was confirmed by the appearance of the quadrupole splitting peaks of the green rust. In the 0.25 M sodium sulfate solution, oxidation of the steel surface proceeded slowly and the quadrupole splitting peaks of Fe(OH) 2 were seen in the CEMS. The peak intensity of Fe(OH) 2 gradually decreased and that of γ-FeOOH increased by the extension of immersion of steel in the solution. Magnetite (Fe 3 O 4 ) layer was developed beneath the γ-FeOOH layer, when steel was dipped in 0.5 M sodium nitrate solution. However, the peaks of Fe 3 O 4 were not seen on CEMS of steel surface immersed in 0.5 M ammonium nitrate solution. Thus, applying the feasibility of CEMS for the characterization of oxidated compounds of iron on the steel surface formed by the immersion in solutions, the oxidation mechanism of the steel surface was discussed based upon the results of chemical state analyses. (author)

  16. Vitamin B12 deficiency presenting as an acute confusional state: a ...

    African Journals Online (AJOL)

    EB

    2013-09-03

    Sep 3, 2013 ... occurred following parenteral vitamin B12 replacement therapy. Conclusion: This case report highlights one of the neuro-psychiatric presentations of vitamin B12 deficiency .... and Occupational Health Abstract No:.

  17. the present state of swahili literature as an artistic and social

    African Journals Online (AJOL)

    Frederick Iraki

    In addressing the urgent problems of present-day world (not on- ... Swahili fiction, 6 of which were written by Tanzanians; by the year 2007, the ... there are additional mechanisms of stimulation – for example, the annual Jomo Kenyatta Prize,.

  18. Phthalate Esters and Reproductive Toxicity** Presentation requested by State of Mass Use Reductions Committee-TURI

    Science.gov (United States)

    Phthalate esters and reproductive toxicity the presentation described the uses of phthalates, the toxicity to mammals with a focus on reproductive toxicity and the potency of these chemicals to disrupt mammalian reproductive development in utero

  19. A United States marine presenting with hemoptysis after push-ups.

    Science.gov (United States)

    Thurber, John S; Unger, Jason A; DeVries, William C

    2014-04-01

    We present an unusual case of right lower lobe intralobar pulmonary sequestration in a previously healthy and physical active 27-year-old U.S. Marine, who presented with new onset hemoptysis after doing push-ups. Diagnosis was obtained by chest X-ray and contrast computed tomography scan. Preoperatively the patient underwent fluoroscopy-guided embolization of the aberrant systemic artery supplying the sequestration. The segmental resection of the sequestration was then successfully performed through a muscle-sparing thoracotomy. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

  20. The present state and future prospects of the radioactive waste and spent fuel management in Lithuania

    International Nuclear Information System (INIS)

    Gylys, J.

    2001-01-01

    The Ignalina nuclear power plant (NPP) is the main source of the spent fuel and the radioactive waste (RW) in Lithuania. Now Lithuania is fully responsible for the management and disposal of its RW and spent fuel. The present scheme of spent fuel, solid, and liquid waste treatment is incomplete. The Department of Thermal and Nuclear Energy at Kaunas University of Technology proposed the new idea - cellular foam apparatus for the concentration of the liquid waste at Ignalina NPP. Some data and main results of the investigation of such apparatus are presented here. (author)

  1. The influence of iridium chemical oxidation state on the performance and durability of oxygen evolution catalysts in PEM electrolysis

    Science.gov (United States)

    Siracusano, S.; Baglio, V.; Grigoriev, S. A.; Merlo, L.; Fateev, V. N.; Aricò, A. S.

    2017-10-01

    Nanosized Ir-black (3 nm) and Ir-oxide (5 nm) oxygen evolution electrocatalysts showing high performance in polymer electrolyte membrane (PEM) water electrolysis based on Aquivion® short-side chain ionomer membrane are investigated to understand the role of the Ir oxidation state on the electrocatalytic activity and stability. Despite the smaller mean crystallite size, the Ir-black electrocatalyst shows significantly lower initial performance than the Ir-oxide. During operation at high current density, the Ir-black shows a decrease of cell potential with time whereas the Ir-oxide catalyst shows increasing cell potential resulting in a degradation rate of about 10 μV/h, approaching 1000 h. The unusual behaviour of the Ir-black results from the oxidation of metallic Ir to IrOx. The Ir-oxide catalyst shows instead a hydrated structure on the surface and a negative shift of about 0.5 eV for the Ir 4f binding energy after 1000 h electrolysis operation. This corresponds to the formation of a sub-stoichiometric Ir-oxide on the surface. These results indicate that a hydrated IrO2 with high oxidation state on the surface is favourable in decreasing the oxygen evolution overpotential. Modifications of the Ir chemical oxidation state during operation can affect significantly the catalytic activity and durability of the electrolysis system.

  2. International Workshop on Exotic Hadronic Atoms, Deeply Bound Kaonic Nuclear States and Antihydrogen : Present Results, Future Challenges

    CERN Document Server

    Widmann, E; Curceanu, C; Trento 2006; Trento06

    2006-01-01

    These are the miniproceedings of the workshop "Exotic hadronic atoms, deeply bound kaonic nuclear states and antihydrogen: present results, future challenges," which was held at the European Centre for Theoretical Nuclear Physics and Related Studies (ECT*), Trento (Italy), June 19-24, 2006. The document includes a short presentation of the topics, the list of participants, and a short contribution from each speaker.

  3. Study of the oxidation state of arsenic and uranium in individual particles from uranium mine tailings, Hungary

    International Nuclear Information System (INIS)

    Alsecz, A.; Osan, J.; Palfalvi, J.; Torok, Sz.; Sajo, I.; Mathe, Z.; Simon, R.; Falkenberg, G.

    2007-01-01

    Uranium ore mining and milling have been terminated in the Mecsek Mountains (southwest Hungary) in 1997. Mine tailings ponds are located between two important water bases, which are resources of the drinking water of the city of Pecs and the neighbouring villages. The average U concentration of the tailings material is 71.73 μg/g, but it is inhomogeneous. Some microscopic particles contain orders of magnitude more U than the rest of the tailings material. Other potentially toxic elements are As and Pb of which chemical state is important to estimate mobility, because in mobile form they can risk the water basis and the public health. Individual U-rich particles were selected with solid state nuclear track detector (SSNTD) and after localisation the particles were investigated by synchrotron radiation based microanalytical techniques. The distribution of elements over the particles was studied by micro beam X-ray fluorescence (μ-XRF) and the oxidation state of uranium and arsenic was determined by micro X-ray absorption near edge structure (μ-XANES) spectroscopy. Some of the measured U-rich particles were chosen for studying the heterogeneity with μ-XRF tomography. Arsenic was present mainly in As(V) and uranium in U(VI) form in the original uranium ore particles, but in the mine tailings samples uranium was present mainly in the less mobile U(IV) form. Correlation was found between the oxidation state of As and U in the same analyzed particles. These results suggest that dissolution of uranium is not expected in short term period. (authors)

  4. The changing face of lower tropospheric sulfur oxides in the United States

    Directory of Open Access Journals (Sweden)

    G. M. Hidy

    2016-12-01

    Full Text Available Abstract Sulfur oxides, sulfur dioxide and airborne sulfate, SOx, are short-lived species in the troposphere whose concentrations in air and precipitation have changed dramatically in association with fossil fuel combustion. The historic rise in concentration is coincident with the era of the so-called “Anthropocene.” Unlike concentrations of long-lived species such as carbon dioxide, atmospheric SOx in the United States (US peaked between 1970 and 2005 then declined. The rise and fall of SOx is traced by comparing national data on emission changes, ambient concentrations, and precipitation sulfate from prior to World War II to the present. Surface SOx concentrations and precipitation sulfate have decreased with emissions in most parts of the US after the late 1970s. Continued reduction toward a natural “background” condition has depended on aggressive management of anthropogenic emission sources. Annual average ambient concentrations of SO2 and SO4 have become more uniform across the US at levels of 1–3 ppbv and 0.3–3 µg/m3, respectively. Precipitation SO4 has a nominal concentration generally less than 0.5 mg/L. The effective lifetime of SOx in the troposphere is a few days. This duration limits the spatial extent of emission source influence of SOx to regional scales, wherein spatial gradients in species concentrations lead to variations in human exposure and impacts on vulnerable terrestrial and aquatic ecosystems. The effects of domestic emission reductions on SOx levels are moderated by intra- and intercontinental transport of SOx from Canada, Mexico, Asia and elsewhere. The trends in tropospheric SOx concentrations illustrate the results of more than a century of rising public awareness and action to progressively reduce a US environmental risk, accomplished with advances in energy production technology that have maintained economic well-being.

  5. Global analysis of genetic variation in human arsenic (+ 3 oxidation state) methyltransferase (AS3MT)

    International Nuclear Information System (INIS)

    Fujihara, Junko; Soejima, Mikiko; Yasuda, Toshihiro; Koda, Yoshiro; Agusa, Tetsuro; Kunito, Takashi; Tongu, Miki; Yamada, Takaya; Takeshita, Haruo

    2010-01-01

    Human arsenic (+ 3 oxidation state) methyltransferase (AS3MT) is known to catalyze the methylation of arsenite. The objective of this study was to investigate the diversity of the AS3MT gene at the global level. The distribution of 18 single nucleotide polymorphisms (SNPs) in AS3MT was performed in 827 individuals from 10 populations (Japanese, Korean, Chinese, Mongolian, Tibetans, Sri Lankan Tamils, Sri Lankan Sinhalese, Nepal Tamangs, Ovambo, and Ghanaian). In the African populations, the A allele in A6144T was not observed; the allele frequencies of C35587 were much lower than those in other populations; the allele frequencies of A37616 and C37950 were relatively higher than those in other populations. Among Asian populations, Mongolians showed a different genotype distribution pattern. A lower C3963 and T6144 frequencies were observed, and, in the C37616A and T37950C polymorphism, the Mongolian population showed higher A37616 and C37950 allele frequencies than other Asian populations, similarly to the African populations. A total of 66 haplotypes were observed in the Ovambo, 48, in the Ghanaian, 99, in the Japanese, 103, in the Korean, 103, in the South Chinese, 20, in the Sri Lankan Tamil, 12, in the Sri Lankan Sinhalese, 21, in the Nepal Tamang, 50, in the Tibetan, and 45, in the Mongolian populations. The D' values between the SNP pairs were extremely high in the Sri Lankan Sinhalese population. Relatively higher D' values were observed in Mongolian and Sri Lankan Tamil populations. Network analysis showed two clusters that may have different origins, African and Asians (Chinese and/or Japanese). The present study is the first to demonstrate the existence of genetic heterogeneity in a world wide distribution of 18 SNPs in AS3MT.

  6. Diversity of Chemical Bonding and Oxidation States in MS4 Molecules of Group 8 Elements.

    Science.gov (United States)

    Huang, Wei; Jiang, Ning; Schwarz, W H Eugen; Yang, Ping; Li, Jun

    2017-08-04

    The geometric and electronic ground-state structures of 30 isomers of six MS 4 molecules (M=Group 8 metals Fe, Ru, Os, Hs, Sm, and Pu) have been studied by using quantum-chemical density functional theory and correlated wavefunction approaches. The MS 4 species were compared to analogous MO 4 species recently investigated (W. Huang, W.-H. Xu, W. H. E. Schwarz, J. Li, Inorg. Chem. 2016, 55, 4616). A metal oxidation state (MOS) with a high value of eight appeared in the low-spin singlet T d geometric species (Os,Hs)S 4 and (Ru,Os,Hs)O 4 , whereas a low MOS of two appeared in the high-spin septet D 2d species Fe(S 2 ) 2 and (slightly excited) metastable Fe(O 2 ) 2 . The ground states of all other molecules had intermediate MOS values, with S 2- , S 2 2- , S 2 1- (and O 2- , O 1- , O 2 2- , O 2 1- ) ligands bonded by ionic, covalent, and correlative contributions. The known tendencies toward lower MOS on going from oxides to sulfides, from Hs to Os to Ru, and from Pu to Sm, and the specific behavior of Fe, were found to arise from the different atomic orbital energies and radii of the (n-1)p core and (n-1)d and (n-2)f valence shells of the metal atoms in row n of the periodic table. The comparative results of the electronic and geometric structures of the MO 4 and MS 4 species provides insight into the periodicity of oxidation states and bonding. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Geochemical landscapes of the conterminous United States; new map presentations for 22 elements

    Science.gov (United States)

    Gustavsson, N.; Bolviken, B.; Smith, D.B.; Severson, R.C.

    2001-01-01

    Geochemical maps of the conterminous United States have been prepared for seven major elements (Al, Ca, Fe, K, Mg, Na, and Ti) and 15 trace elements (As, Ba, Cr, Cu, Hg, Li, Mn, Ni, Pb, Se, Sr, V, Y, Zn, and Zr). The maps are based on an ultra low-density geochemical survey consisting of 1,323 samples of soils and other surficial materials collected from approximately 1960-1975. The data were published by Boerngen and Shacklette (1981) and black-and-white point-symbol geochemical maps were published by Shacklette and Boerngen (1984). The data have been reprocessed using weighted-median and Bootstrap procedures for interpolation and smoothing.

  8. The State of Cell Blocks and Ancillary Testing: Past, Present, and Future.

    Science.gov (United States)

    Saqi, Anjali

    2016-12-01

    Cell blocks are an integral part of cytology, but their utility is recognized probably more now than ever before, largely owing to the significant role they play in ancillary testing, particularly molecular diagnostics. Modifications to improve the cell block method initially introduced more than a century ago have been made over the years. Though their value is acknowledged and they are widely used across laboratories, cell block preparations are not standardized and results of ancillary testing performed on them are inconsistent. This article reviews the state of cell blocks-summarizes the more common, currently available and used methods and their corresponding advantages and shortcomings, outlines the role of alternative techniques (eg, smears), and proposes methods to optimize results.

  9. Riflessioni sull'attuale stato della scienza economica. (Reflections on the present state of economics

    Directory of Open Access Journals (Sweden)

    J. STEINDL

    2013-12-01

    Full Text Available Il documento è un contributo ad una serie di ricordi e riflessioni sulle esperienze professionali di illustri  economisti con Banca Nazionale del Lavoro Quarterly Review iniziatinel 1979. In esso Josef Steindl ricorda le importanti avventi in materia di economia e il proprio lavoro e la vita per riflettere sullo stato dell'economia di oggi .The paper is a contribution to a series of recollections and reflections on the professional experiences of distinguished economists which the Banca Nazionale del Lavoro Quarterly Review started in 1979. In it Josef Steindl recalls the major advents in the field of economics and his own work and life to reflect on the state of today’s economics.JEL: B31, A11

  10. Visible light photoreactivity from hybridization states between carbon nitride bandgap states and valence states in Nb and Ti oxides

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hosik, E-mail: hosiklee@gmail.com [School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology (UNIST), Unist-gil 100 Eonyang-eup, Ulsan 689-798 (Korea, Republic of); Ohno, Takahisa, E-mail: OHNO.Takahisa@nims.go.jp [Global Research Center for Environment and Energy based on Nanomaterials Science (GREEN), National Institute for Material Science, 1-2-1 Sengen, Tsukuba (Japan); Computational Materials Science Unit (CMSU), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0047 (Japan)

    2013-03-29

    Highlights: ► Origin of bandgap reduction for visible photoreactivity is suggested. ► Carbon nitride adsorption in interlayer space can induce the bandgap reduction. ► The electronic structures are studied by density functional theory calculations. - Abstract: For better efficiency as photocatalysts, N-doping for visible light reactivity has been intensively studied in Lamellar niobic and titanic solid acids (HNb{sub 3}O{sub 8}, H{sub 2}Ti{sub 4}O{sub 9}), and its microscopic structures have been debated in this decade. We calculate the layered solid acids’ structures and bandgaps. Bandgap reduction by carbon nitride adsorption in interlayer space is observed computationally. It originates from localized nitrogen states which form delocalized top-valence states by hybridizing with the host oxygen states and can contribute to photo-current.

  11. Present state and prospect of systematics for the properties of even-even nuclei

    International Nuclear Information System (INIS)

    Zhao Yumin; Gu Jinnan

    1993-01-01

    The study of systematics for the properties of even-even nuclei, which is a new research field in nuclei structure, is reviewed. The primary results, including systematic analysis of energy spectra and electromagnetic transition, and the empirical law extracted from experimental data, are presented. It is expected that there will be new developments in the next few years in this fields

  12. Mathematics in Junior and Senior High Schools of Japan: Present State and Prospects.

    Science.gov (United States)

    Miwa, Tatsuro

    1986-01-01

    The present status of mathematics education in Japanese schools is described, focusing on students and on ways to improve high school mathematics education. Data from the Second International Mathematics Study and a Japanese survey test are included, as well as information on student attitudes, improvement, and teaching methods. (MNS)

  13. Distance Learning and Skill Acquisition in Engineering Sciences: Present State and Prospects

    Science.gov (United States)

    Potkonjak, Veljko; Jovanovic, Kosta; Holland, Owen; Uhomoibhi, James

    2013-01-01

    Purpose: The purpose of this paper is to present an improved concept of software-based laboratory exercises, namely a Virtual Laboratory for Engineering Sciences (VLES). Design/methodology/approach: The implementation of distance learning and e-learning in engineering sciences (such as Mechanical and Electrical Engineering) is still far behind…

  14. Introducing a Simple Equation to Express Oxidation States as an Alternative to Using Rules Associated with Words Alone

    Science.gov (United States)

    Minkiewicz, Piotr; Darewicz, Malgorzata; Iwaniak, Anna

    2018-01-01

    A simple equation to calculate the oxidation states (oxidation numbers) of individual atoms in molecules and ions may be introduced instead of rules associated with words alone. The equation includes two of three categories of bonds, classified as proposed by Goodstein: number of bonds with more electronegative atoms and number of bonds with less…

  15. Homogeneity of Continuum Model of an Unsteady State Fixed Bed Reactor for Lean CH4 Oxidation

    Directory of Open Access Journals (Sweden)

    Subagjo

    2014-07-01

    Full Text Available In this study, the homogeneity of the continuum model of a fixed bed reactor operated in steady state and unsteady state systems for lean CH4 oxidation is investigated. The steady-state fixed bed reactor system was operated under once-through direction, while the unsteady-state fixed bed reactor system was operated under flow reversal. The governing equations consisting of mass and energy balances were solved using the FlexPDE software package, version 6. The model selection is indispensable for an effective calculation since the simulation of a reverse flow reactor is time-consuming. The homogeneous and heterogeneous models for steady state operation gave similar conversions and temperature profiles, with a deviation of 0.12 to 0.14%. For reverse flow operation, the deviations of the continuum models of thepseudo-homogeneous and heterogeneous models were in the range of 25-65%. It is suggested that pseudo-homogeneous models can be applied to steady state systems, whereas heterogeneous models have to be applied to unsteady state systems.

  16. SOLID STATE ENERGY CONVERSION ALLIANCE (SECA) SOLID OXIDE FUEL CELL PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh; Jim Powers

    2003-10-01

    This report summarizes the work performed for April 2003--September 2003 reporting period under Cooperative Agreement DE-FC26-01NT41245 for the U.S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid State Energy Conversion Alliance (SECA) Solid oxide Fuel Cell Program''. During this reporting period, the conceptual system design activity was completed. The system design, including strategies for startup, normal operation and shutdown, was defined. Sealant and stack materials for the solid oxide fuel cell (SOFC) stack were identified which are capable of meeting the thermal cycling and degradation requirements. A cell module was tested which achieved a stable performance of 0.238 W/cm{sup 2} at 95% fuel utilization. The external fuel processor design was completed and fabrication begun. Several other advances were made on various aspects of the SOFC system, which are detailed in this report.

  17. SOLID STATE ENERGY CONVERSION ALLIANCE (SECA) SOLID OXIDE FUEL CELL PROGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2003-06-01

    This report summarizes the progress made during the September 2001-March 2002 reporting period under Cooperative Agreement DE-FC26-01NT41245 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program''. The program focuses on the development of a low-cost, high-performance 3-to-10-kW solid oxide fuel cell (SOFC) system suitable for a broad spectrum of power-generation applications. The overall objective of the program is to demonstrate a modular SOFC system that can be configured to create highly efficient, cost-competitive, and environmentally benign power plants tailored to specific markets. When fully developed, the system will meet the efficiency, performance, life, and cost goals for future commercial power plants.

  18. Analysis of influence of the inclusion of residue of kaolin on the properties and on the variation of major oxides present in clay city Bento Fernandes (RN)

    International Nuclear Information System (INIS)

    Silva, Hugo Fernandes Medeiros de; Lima, Cassiano dos Santos; Silva, Gilson Garcia da; Machado, Tercio Graciano; Albuquerque, Rosanne Azevedo de; Gomes, Uilame Umbelino

    2011-01-01

    Research Foundation for Support of Education and Technological Development of Rio Grande do Norte - FUNCERN found that 38% of deposits visited in RN products sold in other states, 20% did not sell tiles RN, 8% preferred the tiles outside. All to supply a market segment demanding and are looking for differentiated products, which require manufacturers of certified quality products contributing to the quality process in the construction industry. It is known that the ceramic bodies are manufactured from the composition of two or more materials with different characteristics in their composition. Thus, one of the key steps is the dosage of raw materials and additives. This device allows to target the many wastes from industry. This paper aims to study the physical and mechanical properties of ceramic body resulting from the inclusion of residual kaolin clay on the city of Bento Fernandes (RN), analyzing the influence of variation of major oxides present in the raw material on the behavior of the final product. (author)

  19. Surface State Capture Cross-Section at the Interface between Silicon and Hafnium Oxide

    Directory of Open Access Journals (Sweden)

    Fu-Chien Chiu

    2013-01-01

    Full Text Available The interfacial properties between silicon and hafnium oxide (HfO2 are explored by the gated-diode method and the subthreshold measurement. The density of interface-trapped charges, the current induced by surface defect centers, the surface recombination velocity, and the surface state capture cross-section are obtained in this work. Among the interfacial properties, the surface state capture cross-section is approximately constant even if the postdeposition annealing condition is changed. This effective capture cross-section of surface states is about 2.4 × 10−15 cm2, which may be an inherent nature in the HfO2/Si interface.

  20. Control of lipid oxidation during exercise: role of energy state and mitochondrial factors

    DEFF Research Database (Denmark)

    Sahlin, K; Harris, R C

    2008-01-01

    Despite considerable progress during recent years our understanding of how lipid oxidation (LOx) is controlled during exercise remains incomplete. This review focuses on the role of mitochondria and energy state in the control of LOx. LOx increases in parallel with increased energy demand up...... to an exercise intensity of about 50-60% of VO(2max) after which the contribution of lipid decreases. The switch from lipid to carbohydrate (CHO) is of energetic advantage due to the increased ATP/O(2) yield. In the low-intensity domain (energy state will stimulate both LOx...... during high-intensity exercise. Another potential mechanism, suggested in this review, is that Acyl-CoA synthetase (ACS), an initial step in LCFA catabolism, functions as a regulator of LOx. ACS activity is suggested to be under control of CoASH and energy state. Furthermore, evidence exists...

  1. Optically induced bistable states in metal/tunnel-oxide/semiconductor /MTOS/ junctions

    Science.gov (United States)

    Lai, S. K.; Dressendorfer, P. V.; Ma, T. P.; Barker, R. C.

    1981-01-01

    A new switching phenomenon in metal-oxide semiconductor tunnel junction has been discovered. With a sufficiently large negative bias applied to the electrode, incident visible light of intensity greater than about 1 microW/sq cm causes the reverse-biased junction to switch from a low-current to a high-current state. It is believed that hot-electron-induced impact ionization provides the positive feedback necessary for switching, and causes the junction to remain in its high-current state after the optical excitation is removed. The junction may be switched back to the low-current state electrically. The basic junction characteristics have been measured, and a simple model for the switching phenomenon has been developed.

  2. Birth in the United States: an overview of trends past and present.

    Science.gov (United States)

    McCool, William F; Simeone, Sara A

    2002-12-01

    The picture of birth in the United States today is complex and, as the data above indicates, difficult to describe in simplistic terms. Though many women today have come to believe that there are choices surrounding pregnancy and birth, the beliefs and practices of providers, insurers, and hospital administrators play a major role in either influencing those choices or dictating how they will be manifested. On one hand, technological advances have given women greater options with regard to the outcomes of pregnancy and birth. On the other hand, these very same technological advances place limits on the choices available to the individual. For example, increased efficiency in the placement and use of epidural anesthesia has made this a pain-control option for most of the childbearing women in the United States. The use of an epidural, however, puts limits on the choice of an institution at which to give birth and on the movements/activities of the woman during labor. Twentieth-century developments led to the almost complete demise of midwifery practice in the United States, thus taking birth away from the control of the individual woman and her close, matriarchal support system, and placing it in the hands of the patriarchal world of medicine and the institutions (i.e., hospitals) at which this approach to health care is practiced. Most births went from being normal, home-based events to becoming illness-oriented, hospital-based procedures. Just as some steps were being taken in the latter part of the twentieth century to return some of the control of birth back to pregnant women (e.g., childbirth education classes, the modern home-birth movement, increases in the number of midwifery-tended births), technological advances contributed to continued control by physicians and the hospitals of their practice (e.g., fetal monitoring, epidural anesthesia). Advances in technology have made birth possible for many individuals who otherwise would not have had the opportunity

  3. The Place of Entrepreneurship in Higher Education – Present State and Perspectives

    Directory of Open Access Journals (Sweden)

    Iga Kott

    2015-05-01

    Full Text Available Entrepreneurship is one of the main driving forces of the national economies. In Poland, more and more jobs are created in private enterprises, set up and running by entrepreneurs. Entrepreneurs are characterized as people, which seize the opportunity to act, have higher self-esteem and a greater sense of control over their lives, and they, usually become successful people. This causes a widespread conviction, that the promotion of entrepreneurship, may result in maximizing the success of both, individual and in the scale of the national economy as well. Therefore, it becomes important to develop standards in the field of entrepreneurship education, the greater numbers of people would have been able to achieve a professional success. This article presents the essence of the entrepreneurship and the role of education, in entrepreneurship’s excitation or strengthening. Also a practical example of the implementation of these provisions by one of the Polish Universities - Czestochowa University of Technology, is presented.

  4. Magic Garden of Bogosav Živković: The present state and proposed protection measures

    Directory of Open Access Journals (Sweden)

    Živković Nada

    2017-01-01

    Full Text Available The Magic Garden of Bogosav Živković in the Leskovac village is a 23.32 acres large complex, spontaneously formed in the 1970s. The spatial concept of the artist was to adjust the artistic creativity and presentation to daily household life. In addition to the valuable works of art exhibited in both the open space and interior, the residential and other buildings do not display particular architectural significance; yet, each of these buildings bears impressive marks of the artist in the form of paintings, reliefs, brass eaves or even household items that, when placed in an unusual setting, become exhibits. The aim of the paper is to present the condition of the site, to draw attention to the value of this space and to propose measures for its protection.

  5. Evolution of the Oxidation State of the Earth's Mantle: Challenges of High Pressure Quenching

    Science.gov (United States)

    Danielson, L. R.; Righter, K.; Keller, L.; Christoffersen, R.; Rahman, Z.

    2015-01-01

    The oxidation state of the Earth's mantle during formation remains an unresolved question, whether it was constant throughout planetary accretion, transitioned from reduced to oxidized, or from oxidized to reduced. We investigate the stability of Fe3+ at depth, in order to constrain processes (water, late accretion, dissociation of FeO) which may reduce or oxidize the Earth's mantle. Experiments of more mafic compositions and at higher pressures commonly form a polyphase quench intergrowth composed primarily of pyroxenes, with interstitial glass which hosts nearly all of the more volatile minor elements. In our previous experiments on shergottite compositions, variable fO2, T, and P is less than 4 GPa, Fe3+/TotFe decreased slightly with increasing P, similar to terrestrial basalt. For oxidizing experiments less than 7GPa, Fe3+/TotFe decreased as well, but it's unclear from previous modelling whether the deeper mantle could retain significant Fe3+. Our current experiments expand our pressure range deeper into the Earth's mantle and focus on compositions and conditions relevant to the early Earth. Experiments with Knippa basalt as the starting composition were conducted at 1-8 GPa and 1800 C, using a molybdenum capsule to set the fO2 near IW, by buffering with Mo-MoO3. TEM and EELS analyses revealed the run products from 7-8 GPa quenched to polycrystalline phases, with the major phase pyroxene containing approximately equal Fe3+/2+. A number of different approaches have been employed to produce glassy samples that can be measured by EELS and XANES. A more intermediate andesite was used in one experiment, and decompression during quenching was attempted after, but both resulted in a finer grained polyphase texture. Experiments are currently underway to test different capsule materials may affect quench texture. A preliminary experiment using liquid nitrogen to greatly enhance the rate of cooling of the assembly has also been attempted and this technique will be

  6. March to Armageddon: The United States and the nuclear arms race, 1939 to the present

    Energy Technology Data Exchange (ETDEWEB)

    Powaski, R.

    1987-01-01

    This history of the events, forces, and factors that have brought the world to the brink of nuclear holocaust probes two basic questions: what factors perpetuate the nuclear arms race and why is it so difficult to end. Starting with the opening days of World War II, this study traces the escalating arms race up to the present and notes that, while nuclear arsenals continue to grow, nuclear arms treaties are on the verge of collapse.

  7. Taeniasis and cysticercosis in Asia and the Pacific: present state of knowledge and perspectives.

    Science.gov (United States)

    Ito, Akira; Nakao, Minoru; Wandra, Toni; Suroso, Thomas; Okamoto, Munehiro; Yamasaki, Hiroshi; Sako, Yasuhito; Nakaya, Kazuhiro

    2005-01-01

    Several topics on taeniasis and cysticercosis in Asia and the Pacific are overviewed. In Asia and the Pacific, three human taeniid species have been recognized: Taenia solium, Taenia saginata and Taenia asiatica. The first topic is on evolution of T. solium. Mitochondrial DNA polymorphisms of T. solium worldwide are discussed with emphasis of two specific genotypes: American-African and Asian. The second topic is recent major advances in sero- and molecular-diagnosis of T. solium cysticercosis in humans, pigs and dogs. The third is the present situation of T. solium taeniasis/cysticercosis in Papua (Irian Jaya), Indonesia. The forth is the present situation of T. solium cysticercosis and T. saginata taeniasis in Bali, Indonesia. The fifth is the present situation of T. asiatica taeniasis in Asia and the Pacific and in North Sumatra, Indonesia. The sixth is on the debate of the exact definition of T. asiatica. Because T. asiatica can not be differentiated from T. saginata morphologically, it is time to re-evaluate T. saginata in Asia and the Pacific. New and broad-based surveys across this region are necessary from epidemiological and public health perspectives, based on evidence.

  8. LIBERALISATION OF THE ELECTRICITY SECTOR IN THE EUROPEAN UNION: PRESENT STATE AND SOME OPEN QUESTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, A.

    2007-07-01

    The liberalisation of the electricity sector started approximately 10 to 15 years ago, depending on the country. Nonetheless, there is still no general agreement on the liberalisation model this sector should follow, mainly because of the discussion of whether the liberalisation is an end in itself, or a means for -basically- lower energy prices. The complexity of the sector and the resilience of the incumbents' market power have currently placed the liberalisation process at a crossroad. In the EU, entrenched national interests are another obstacle to deal with. In this article, we first give an overview of the different liberalisation processes in the electricity sector and then summarize the pending challenges from an EU perspective. Next, we argue that the EU should focus on conditions aiming at implementing an effective liberalisation process, rather than on a formal liberalisation approach. We show how asymmetries between non-sector regulations in the European states and among companies create an uneven playing field, contrary to the European vision of an internal competitive energy market. We end the article studying the compatibility of the current European regulatory framework with the upcoming challenges in the energy sector. (auth)

  9. EU — Russia energy cooperation: major development trends and the present state

    Directory of Open Access Journals (Sweden)

    Romanova Tatyana

    2013-09-01

    Full Text Available The article analyzes the development of EU — Russia energy relations through the lens of the evolution of three parameters: the political agenda (the Energy Dialogue, the institutional structure, and the legal modalities. The identification of these three aspects for assessing the evolution of EU — Russia energy relations is the novelty in the author’s approach. This study aims to identify the previous stages and assess the current state of EU — Russia energy dialogue, since they set out conditions for energy cooperation in the Baltic Sea region. This research is based on a political and legal analysis of various documents and employs various international relations theories (including integration theories. The article demonstrates that the EU nd Russia have made a transition to the integration agenda manifested in the Energy Dialogue (its current goal is the creation of a common European energy market. The author describes the process of gradual consolidation of transgovernmental and transnational institutions, which leads to depoliticization of cooperation and mutual socialization of the partners. Finally, legal discussions on the development of common rules have become more constructive. In sum, the current situation in EU — Russia energy relations is favourable and positively affects cooperation in the Baltic Sea region.

  10. Magnetic resonance imaging of the cardiovascular system: present state of the art and future potential

    International Nuclear Information System (INIS)

    Jacobson, H.G.

    1988-01-01

    State-of-the-art magnetic resonance imaging (MRI) generates high-resolution images of the cardiovascular system. Conventional MRI techniques provide images in six to ten minutes per tomographic slice. New strategies have substantially improved the speed of imaging. The technology is relatively expensive, and its cost-effectiveness remains to be defined in relation to other effective, less expensive, and noninvasive technologies, such as echocardiography and nuclear medicine. The ultimate role of MRI will depend on several factors, including the development of specific applications such as (1) noninvasive angiography, especially of the coronary arteries;(2) noninvasive, high-resolution assessment of regional myocardial blood flow distribution (e.g., using paramagnetic contrast agents); (3) characterization of myocardial diseases using proton-relaxation property changes; and (4) evaluation of in vivo myocardial biochemistry. The three-dimensional imaging capability and the ability to image cardiovascular structures without contrast material give MRI a potential advantage over existing noninvasive diagnostic imaging techniques. This report analyzes current applications of MRI to the cardiovascular system and speculates on their future

  11. Pediatric Firework-Related Injuries Presenting to United States Emergency Departments, 1990-2014.

    Science.gov (United States)

    Billock, Rachael M; Chounthirath, Thiphalak; Smith, Gary A

    2017-06-01

    This study characterizes the epidemiology of nonfatal pediatric firework-related injuries in the United States among children and adolescents by analyzing data from the National Electronic Injury Surveillance System from 1990 through 2014. During this 25-year period, an estimated 136 991 (95% CI = 113 574-160 408) children firework-related injuries. The annual injury rate decreased significantly by 30.4% during this period. Most of those injured were male (75.7%), mean patient age was 10.6 years, and 7.6% required hospital admission. The hands (30.0%) were the most commonly injured body region, followed by head and neck (22.2%), and eyes (21.5%). Sixty percent of injuries were burns. Injuries were most commonly associated with firecrackers (26.2%), aerial devices (16.3%), and sparklers (14.3%). Consumer fireworks pose a serious injury risk to pediatric users and bystanders, and families should be encouraged to attend public firework displays rather than use consumer fireworks.

  12. New medical schools in the United States: forces of change past and present.

    Science.gov (United States)

    Smith, Lawrence

    2009-01-01

    The new millennium has ushered in a growth phase in the number of American medical schools. Historically the United States has built schools during bursts of activity with relative quiescence in between these periods. We had a twenty-two year period with no growth in medical school size or number. During that time there were significant changes in patient characteristics, student culture, financial reimbursement, quality, and manpower needs that have put stress on medical schools, hospitals, clinical practice and healthcare systems. In addition, there have been remarkable new opportunities in the way we teach, including changes in teaching methodology, educational technology, and a better understanding of how students actually learn. All of these advances have taken place during a period of enormous pressure to change residency programs, reorganize medical and clinical science, and question the very need for traditional departmental structures. It is likely that the new medical schools will emerge looking different from the older schools and they are likely to catalyze a period of curricular change.

  13. Estimate of the Geothermal Energy Resource in the Major Sedimentary Basins in the United States (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Esposito, A.; Porro, C.; Augustine, C.; Roberts, B.

    2012-09-01

    Because most sedimentary basins have been explored for oil and gas, well logs, temperatures at depth, and reservoir properties such as depth to basement and formation thickness are well known. The availability of this data reduces exploration risk and allows development of geologic exploration models for each basin. This study estimates the magnitude of recoverable geothermal energy from 15 major known U.S. sedimentary basins and ranks these basins relative to their potential. The total available thermal resource for each basin was estimated using the volumetric heat-in-place method originally proposed by (Muffler, 1979). A qualitative recovery factor was determined for each basin based on data on flow volume, hydrothermal recharge, and vertical and horizontal permeability. Total sedimentary thickness maps, stratigraphic columns, cross sections, and temperature gradient information was gathered for each basin from published articles, USGS reports, and state geological survey reports. When published data were insufficient, thermal gradients and reservoir properties were derived from oil and gas well logs obtained on oil and gas commission databases. Basin stratigraphy, structural history, and groundwater circulation patterns were studied in order to develop a model that estimates resource size, temperature distribution, and a probable quantitative recovery factor.

  14. Present State and Future Developments in Mechatronics and it's Influence on Fluid Power Systems

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg; Zhou, Jianjun; Conrad, Finn

    1998-01-01

    with electronics, software and mechanics. This synergetic integration is often called Mechatronics.The topic which is rather widespread will be treated in three sections: I) General overview of mechatronics and fluid power. In this section the general trends of mechatronics in fluid power is considered by relating...... trends in the neighbouring fields of software and electronic hardware to fluid power developments. II) Mechatronic case stories from IKS In this section the results of a conceptual design study : "Design of a frequency converter based hydraulic power supply" is presented together with a more detailed...

  15. Shallow moonquakes - Depth, distribution and implications as to the present state of the lunar interior

    Science.gov (United States)

    Nakamura, Y.; Latham, G. V.; Dorman, H. J.; Ibrahim, A.-B. K.; Koyama, J.; Horvath, P.

    1979-01-01

    The observed seismic amplitudes of HFT (high-frequency teleseismic) events do not vary with distance as expected for surface sources, but are consistent with sources in the upper mantle of the moon. Thus, the upper mantle of the moon is the only zone where tectonic stresses deriving from differential thermal contraction and expansion of the lunar interior are presently high enough to cause moonquakes. The distribution of shallow moonquake epicenters suggests a possible correlation with impact basins, implying a lasting tectonic influence of impact basins long after their formation. The finite depths now assigned to these shallow moonquakes necessitate further revision to the seismic structural model of the lunar interior.

  16. Short-Term fo F2 Forecast: Present Day State of Art

    Science.gov (United States)

    Mikhailov, A. V.; Depuev, V. H.; Depueva, A. H.

    An analysis of the F2-layer short-term forecast problem has been done. Both objective and methodological problems prevent us from a deliberate F2-layer forecast issuing at present. An empirical approach based on statistical methods may be recommended for practical use. A forecast method based on a new aeronomic index (a proxy) AI has been proposed and tested over selected 64 severe storm events. The method provides an acceptable prediction accuracy both for strongly disturbed and quiet conditions. The problems with the prediction of the F2-layer quiet-time disturbances as well as some other unsolved problems are discussed

  17. Pleuropulmonary blastoma--case report of a patient presenting in a moribund state.

    Science.gov (United States)

    Chauke, Risenga Frank; Muthuphei, M Nelson

    2003-11-01

    A 4-year-old girl presented with an intrathoracic tumour that was pleural in origin, invading the right lower lobe. The patient underwent urgent right thoracotomy and surgical excision of the tumour and right lower lobectomy as the tumour was invading that lobe. The histological report initially reported it as a rhabdomyosarcoma, embryonal type, but after consultation it was changed to type III pleuropulmonary blastoma. The patient was treated with chemotherapy but succumbed to the disease 12 months after the diagnosis. Relevant literature on pleuropulmonary blastoma is reviewed.

  18. Present day state of knowledge of α/β allotropic transformation of uranium

    International Nuclear Information System (INIS)

    Englander, M.

    1960-01-01

    The technological conditions of the problem of α/β allotropic transformation of uranium are presented first. Then, the author explains the qualitative reasons why in non-allied uranium: 1) the new phase germination follows a consistent process; 2) the new phase growth, at the expense of the mother phase, proceeds either by martensitic-type shear or by thermal diffusion if the temperature and impurities amount are high enough. Reprint of a paper published in La Mettalurgia Italiana, vol. LI, no. 11, p. 497-504, 1959 [fr

  19. Present state of the liner of the reactor; Estado actual del liner del reactor

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar H, F; Raya A, R; Mazon R, R [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-07-15

    When being presented to work the operation personnel of the reactor, on Monday January 10, 1983, they noticed that the reactor pool was overflowing of water and the floor of the room was partially flooded. The personnel proceeded to revise the feedwater systems to the pool, the Emergency Cooling System of the core and that of Water of Reinstatement, was found that the passing valve of this last it was lightly open. It was discovered that the water that was flooded in the floor of the room it came from the relief valves of the ports TW-1 and RW-2 and of three glides that were in the Thermal Column area. It was proceeded to lower the one level of water of the pool to their normal position and it was clean the water flooded in the salts. (Author)

  20. One coal miner's perspective on the present United States coal industry

    Energy Technology Data Exchange (ETDEWEB)

    Murray, R.E. [Murray Energy Corp., Pepper Pike, OH (United States)

    2002-07-01

    The President and CEO of the Murray Energy Corporation presented his observations on and concerns about the coal and energy industries in the USA, as a coal miner and an energy trader. He outlines the coal mining operations of the Murray Energy Corporation. He offers critical comments about, for example, some unscrupulous energy trading activities, the future of Powder River Basin coal (which he believes may be curtailed by the introduction of clean coal technologies), the lack of expertise in coal mining, the need to revise the law concerning coal company bankruptcies, the need for the government to provide a means to secure bonds, the need to liberalize black lung disease benefits, and the factors deterring improvement of the performance of the eastern coal industry. He criticises current policy and puts forward some recommendations.

  1. A Souvenir From France: Acrodermatitis Chronica Atrophicans Presenting in the United States.

    Science.gov (United States)

    Correa-Selm, Lilia M; Bronsnick, Tara; Rao, Babar K; Kirkorian, A Yasmine; Marcus, Alan; Cha, Jisun

    2016-01-01

    A 70-year-old man was referred by his rheumatologist to our dermatology clinic for evaluation of dermatitis on his right arm that appeared 3 months earlier. The skin lesion was asymptomatic and the patient denied current systemic symptoms, including fever, chills, and joint pain; however, 10 months prior to this presentation he experienced arthritis in the left knee. At that time, Borrelia serology revealed positive IgG (6.07; <0.8 negative, 0.8 to 0.99 borderline, ≥1 positive) and negative IgM titers. The patient had not received treatment for Lyme disease in the past. He was referred to rheumatology for evaluation of possible Lyme disease but did not follow up until 10 months later. The arthritis has since resolved. He travels frequently to France and recalls multiple tick bites during these trips.

  2. Old water structures. River Kullaa as an example: their history, present state and plans for development

    International Nuclear Information System (INIS)

    Koeykkae, S.; Siirala, M.

    1996-01-01

    The aim was to make an inventory of the structures and buildings relating to the history of the use of hydropower along the River Kullaa, which runs into the River Kokemaeki, and to determine how they could be conserved and used in future. Their history and the 1990-91 status will serve as starting points for a master scheme, local plans and plans for individual rapids. The publication first gives a general account of the history of the use of hydropower and the development of hydropower plants. Information has been collected on the establishment and development of structures along the River Kullaa. The 1990-91 status has been established on the basis of inventories and measurements made in the field. The master scheme first examines the River Kullaa and its structures as a whole. Along the river there are three areas, whose development is discussed in the local plans. Finally, plans for the individual rapids are presented for three sites. (author)

  3. Present state of the safety concept of natural-draught cooling towers

    International Nuclear Information System (INIS)

    Kraetzig, W.B.

    1977-01-01

    Safety and reliability of a building depend on the mechanical model chosen, on the shape deviations of the structure, as well as on the distribution functions and fractile values of the main influences and strength properties of the materials. For the shell, the supports, and the foundation of a natural-draught cooling tower, the wind plays a special, safety-reducing role due to the fact that its upper limit remains unknown. This role is still enhanced by the dead weight of the concrete which partially exceeds the tensile load. This requires a dimensioning concept with partial safety coefficients which is established in the present paper. So far, it has been successfully used in the construction of more than 50 cooling towers. (orig.) [de

  4. Sports-related genitourinary injuries presenting to United States emergency departments.

    Science.gov (United States)

    Bagga, Herman S; Fisher, Patrick B; Tasian, Gregory E; Blaschko, Sarah D; McCulloch, Charles E; McAninch, Jack W; Breyer, Benjamin N

    2015-01-01

    To describe epidemiologic features of sports-related genitourinary (GU) injuries and determine patient cohorts and particular sporting activities associated with increased GU injury risk. The National Electronic Injury Surveillance System, a data set validated to provide a probability sample of injury-related US emergency department (ED) presentations, was analyzed to characterize GU injuries between 2002 and 2010. A total of 13,851 observations were analyzed to derive national estimates. Between 2002 and 2010, an estimated 137,525 individuals (95% confidence interval, 104,490-170,620) presented to US EDs with GU injuries sustained during sporting activities. Nearly three-quarters of injuries occurred in the pediatric population. The most common product involved was a bicycle, representing approximately one-third of injuries in both adult and pediatric populations. Injuries related to team sports such as football, baseball or softball, basketball, and soccer were also common, particularly among boys where they represented a combined third of all injuries. Eighty-nine percent of all patients were evaluated and treated in the ED without inpatient admission. The large majority of injuries involved the external genitalia (60%), and significant injuries of paired GU organs (kidneys and testicles) requiring inpatient admission were rare (8.5%). Sports-related GU injuries are most commonly sustained during the use of a bicycle. However, there are other associated activities with identifiable high-risk cohorts, products, and situations. Consumers, practitioners, and injury-prevention experts can use our epidemiologic data to prioritize and develop strategies aimed at the prevention and limitation of such injuries, particularly when counseling at-risk cohorts, such as those with solitary kidneys or testicles. Copyright © 2015. Published by Elsevier Inc.

  5. The state of permanganate with relation to in situ chemical oxidation

    International Nuclear Information System (INIS)

    Veronda, Brenda; Dingens, Matthew

    2007-01-01

    In Situ Chemical Oxidation (ISCO) with permanganate had its beginnings over 10 years ago. Since that time, many sites have been successfully treated for organic compounds including chlorinated ethenes (perchloroethylene, trichloroethylene, etc.) phenols, explosives such as RDX, and many other organics. The successful application of ISCO with permanganate requires the integration of many site-specific factors into the remedial design. ISCO with permanganate is an effective technology, not only for its oxidative properties and persistence, but also for its application flexibility to remediate soil and groundwater. The merits of any type of treatment technology can be assessed in terms of effectiveness, ease of use, reaction rate, and cost. The use of permanganate for in situ chemical oxidation results in the complete mineralization of TCE and PCE and can result in treatment levels below detection limits. Permanganate is a single component oxidizer, which is easily handled, mixed and distributed to the subsurface. Permanganate is also inexpensive to design and implement as compared to other technologies. This presentation will provide a general overview of the application and safety aspects of ISCO with permanganate. This paper will discuss the advantages and limitations of this technology, typical cost ranges, site evaluation and application technologies. (authors)

  6. Solid-state electrochromic cell with anodic iridium oxide film electrodes

    International Nuclear Information System (INIS)

    Dautremont-Smith, W.C.; Beni, G.; Schiavone, L.M.; Shay, J.L.

    1979-01-01

    A new solid-state electrochromic cell has been fabricated using an anodic iridium oxide film (AIROF) display electrode. The cell has the symmetric sandwich structure AIROFvertical-barNafionvertical-barAIROF, with the Nafion solid electrolyte opacified by an in situ precipitation technique. A symmetric square-wave voltage of 1.5 V amplitude produces clearly perceivable color changes from pale to dark blue-gray in approx. =1 sec when viewed in diffuse reflection. Good open-circuit optical memory is exhibited:

  7. The presentation and pregnancy outcome among teenage parturients in state specialist hospital, Asubiaro, Osogbo, Southwestern, Nigeria

    Directory of Open Access Journals (Sweden)

    Olalekan Olugbenga Awolola

    2018-01-01

    Full Text Available Background: Teenage pregnancies are pregnancies between the age group of 13 and 19 years. Such pregnancies are categorized as high-risk pregnancies worldwide. This makes monitoring during the antenatal, intrapartum, and puerperal periods highly important. Objectives: The aim of this study is to determine the incidence, the mode of presentation, and the materno-fetal outcome in teenage parturients and compare with a control group. Materials and Methods: this prospective case–control study, recruited 63 teenage parturients who presented in labor ward in active phase labour between February 2013 and January 2015. These teenage parturients were matched with a control group in terms of parity and cervical dilatation of not less than or more than 1 cm (+1 cm, but are of age, 22–30 years. Thus, a total number of 126 parturients were studied. The mothers and their babies were followed up until the first 7th day postpartum. Results: In this study, 39 (61.90% and 24 (38.10% were married and unmarried, respectively, among the teenage parturients, whereas 60 (95.24% and 3 (4.7% were married and unmarried among the control group. Majority of the teenage parturients, 57 (90.47% had only primary and secondary education, while 59 (93.47% among the controls had secondary and tertiary levels of education. There were statistically significant differences in the incidences of genital lacerations (9 [14.28%] and 2 [3.18%]: P < 0.05, and the incidences of anemia in pregnancy (9 [14.28%] vs. 2 [3.18%]: P < 0.05 in the teenage and the older parturients. The other outcome measures in the two groups were similar. Conclusion: This study showed that teenage pregnancies with good antenatal, intrapartum, and neonatal care, gives almost the same materno-fetal outcomes as the control group. The determining factors for poor maternal and fetal outcomes are poor socioeconomic status and lack or poor quality of antenatal, intrapartum, and puerperal care.

  8. Present state of development of demonstration FBR and prospect of practical use

    International Nuclear Information System (INIS)

    Inagaki, Tatsutoshi

    1996-01-01

    As for the FBR development in Japan, the Atomic Energy Commission revised the long term plan on the research, development and utilization of atomic energy in June, 1994, and under the basic policy that through the considerable period of using LWRs together, FBRs will be adopted as the main nuclear power plants in future, it was decided to establish FBR technology system so that the practical use of FBRs becomes feasible by about 2030 through two demonstration FBRs following the experimental FBR 'Joyo' and the prototype FBR 'Monju'. The Monju started power generation and transmission in August, 1995, but secondary sodium leak accident occurred in December, 1995, and at present it is stopped. The demonstration FBR No. 1 is a top entry type loop reactor, and the power output is about 660 MWe. The start of construction is scheduled at the beginning of 2000s. The research on the whole plant design is carried out as the research on the optimization of demonstration FBR plant for three years from fiscal year 1994. The design of the demonstration FBR No. 1, the research and development for it, the prospect of the practical use and the research and development for the practical use are reported. (K.I.)

  9. Report on the trainings for terrorism. Document on present state of affairs

    International Nuclear Information System (INIS)

    Noda, Kimio; Saito, Toru; Hukumoto, Masahiro

    2001-12-01

    A series of attacks on America by terrorism on September 11, 2001 gave us a terrible shock. Two types of training against the act of terrorism had been held in Tokai Works of the Japan Nuclear Cycle Development Institute (JNC) to grasp the present situation of JNC Tokai Works and improve the countermeasure against the terrorism. The first training was for the incendiarism and the second one was for the injury. Consequently the revealed points to be improved were the followings. (1) Keeping a sense of crisis. The countermeasure against terrorism should be instructed and trained to realize the sense of crisis, that is, uncertainty of the time and the kind of terrorism. (2) Organization of the structure against the terrorism. The structure for the contingency should to organized to strengthen the guard structure by forming the pursuit team, the guard team and so on constituted by JNC's staff members. (3) Preparation of equipments against the terrorism. The coloring ball, club, two-pronged weapon, shield, knifeproof vest and so on should be provided the guards of to strengthen the countermeasure before the police's arrival. (4) Preparation and announcement of manuals. The manuals against terrorism for the ordinary stuff members should be prepared and used in the training to make the ordinary stuff's countermeasure more effective. (author)

  10. The present state and future of the development of dimension stone mining in Slovak conditions

    Directory of Open Access Journals (Sweden)

    Viliam Žiaran

    2005-03-01

    Full Text Available In comparing to both ores and energetical minerals there are occurences of extremly rich non-methallics minerals on the Slovak territory. These minerals represent very large-scale sortiment with a considerable amount of verified reserves. Reserves of magnesite, salt rock, dolomite, limestone, talc, bentonite, clays and another construction minerals present many possibilities of their industrial utilization. A specific case is the mining of dimension stones such as stable ingeneous,sedimentary and metamorphic rocks that are mined in the open-pit blocks. Applicable to the production of both ingeneous stone and gross stone [3].The open-pit mining and dimension stone processing by the both above mentioned stone productions forms are focused mainly to the external and internal building industry. Despite of the fact that the natural reserves of dimension stone are limited at the Slovak territory, being distributed at large numbers of open-pits mines, from the point of view of the next development of the dimension stone industry its technical and economic vitalitycan be expected. The paper deals with both the technological and ecological mining problems of dimension stone and shows the possibilities how to improve both the works productivity and quality of products including the ecological impacts by the dimension stone mining.

  11. The state of head injury biomechanics: past, present, and future part 2: physical experimentation.

    Science.gov (United States)

    Goldsmith, Werner; Monson, Kenneth L

    2005-01-01

    This presentation is the continuation of the article published in Critical Reviews of Biomedical Engineering, 29(5-6), 2001. That issue contained topics dealing with components and geometry of the human head, classification of head injuries, some early experimental studies, and tolerance considerations. It then dealt with head motion and load characterization, investigations during the period from 1939 to 1966, injury causation and early modeling efforts, the 1966 Head Injury Conference and its sequels, mechanical properties of solid tissues, fluid characterization, and early investigation of the mechanical properties of cranial materials. It continued with a description of the systematic investigations of solid cranial components and structural properties since 1966, fetal cranial properties, analytical head modeling, and numerical solutions of head injury. The paper concluded with experimental dynamic loading of human living and cadaver heads, dynamic loading of surrogate heads, and head injury mechanics. This portion of the paper describes physical head injury experimentation involving animals, primarily primates, human cadavers, volunteers, and inanimate physical models. In order to address the entire domain of head injury biomechanics in the two-part survey, it was intended that this information be supplemented by discussions of head injury tolerance and criteria, automotive and sports safety considerations, and the design of protective equipment, but Professor Goldsmith passed away before these sections could be completed. It is nevertheless anticipated that this attenuated installment will provide, in conjunction with the first part of the survey, a valuable resource for students and practitioners of head injury biomechanics.

  12. Anodic oxidation

    CERN Document Server

    Ross, Sidney D; Rudd, Eric J; Blomquist, Alfred T; Wasserman, Harry H

    2013-01-01

    Anodic Oxidation covers the application of the concept, principles, and methods of electrochemistry to organic reactions. This book is composed of two parts encompassing 12 chapters that consider the mechanism of anodic oxidation. Part I surveys the theory and methods of electrochemistry as applied to organic reactions. These parts also present the mathematical equations to describe the kinetics of electrode reactions using both polarographic and steady-state conditions. Part II examines the anodic oxidation of organic substrates by the functional group initially attacked. This part particular

  13. N-Oxide-N-oxide interactions and Cl...Cl halogen bonds in pentachloropyridine N-oxide: the many-body approach to interactions in the crystal state.

    Science.gov (United States)

    Wzgarda-Raj, Kinga; Rybarczyk-Pirek, Agnieszka J; Wojtulewski, Sławomir; Palusiak, Marcin

    2018-02-01

    Pentachloropyridine N-oxide, C 5 Cl 5 NO, crystallizes in the monoclinic space group P2 1 /c. In the crystal structure, molecules are linked by C-Cl...Cl halogen bonds into infinite ribbons extending along the crystallographic [100] direction. These molecular aggregates are further stabilized by very short intermolecular N-oxide-N-oxide interactions into herringbone motifs. Computations based on quantum chemistry methods allowed for a more detailed description of the N-oxide-N-oxide interactions and Cl...Cl halogen bonds. For this purpose, Hirshfeld surface analysis and the many-body approach to interaction energy were applied.

  14. Micro-XANES measurements on experimental spinels and the oxidation state of vanadium in coexisting spinel and silicate melt

    International Nuclear Information System (INIS)

    Righter, K.; Sutton, S.R.; Newville, M.; Le, L.; Schwandt, C.S.

    2006-01-01

    We show that experimental spinels coexisting with silicate melt always have lower valence vanadium, and that spinels typically have 3+, whereas the coexisting melt has 4+ or 5+. Implications of these results for planetary basalts will be discussed. Spinel can be a significant host phase for V which has multiple oxidation states V 2+ , V 3+ , V 4+ or V 5+ at oxygen fugacities relevant to natural systems. The magnitude of D(V) spinel/melt is known to be a function of composition, temperature and fO 2 , but the uncertainty of the oxidation state under the range of natural conditions has made elusive a thorough understanding of D(V) spinel/melt. For example, V 3+ is likely to be stable in spinels, based on exchange with Al in experiments in the CaO-MgO-Al 2 O 3 -SiO 2 system. On the other hand, it has been argued that V 4+ will be stable across the range of natural oxygen fugacities in nature. In order to build on our previous work in more oxidized systems, we have carried out experiments at relatively reducing conditions from the FMQ buffer to 2 log fO 2 units below the IW buffer. These spinel-melt pairs, where V is present in the spinel at natural levels (∼300 ppm V), were analyzed using an electron microprobe at NASA-JSC and mi-cro-XANES at the Advanced Photon Source at Argonne National Laboratory. The new results will be used together with previous results to understand the valence of V in spinel-melt systems across 12 orders of magnitude of oxygen fugacity, and with application to natural systems.

  15. Youth versus adult "weightlifting" injuries presenting to United States emergency rooms: accidental versus nonaccidental injury mechanisms.

    Science.gov (United States)

    Myer, Gregory D; Quatman, Carmen E; Khoury, Jane; Wall, Eric J; Hewett, Timothy E

    2009-10-01

    Resistance training has previously been purported to be unsafe and ineffective in children. The purpose of this investigation was to evaluate resistance training-related injuries presenting to U.S. emergency rooms by age, type, and mechanism of injury. We hypothesized that older athletes would sustain greater percentages of joint sprains and muscle strains, whereas younger athletes would sustain a greater percentage of accidental injuries that would result in an increased percentage of fractures in youths. The U.S. Consumer Product Safety Commission (CPSC) National Electronic Injury Surveillance System was queried from 2002 to 2005 using the CPSC code for "Weightlifting." Subjects between the ages of 8 and 30 were grouped by age categories 8 to 13 (elementary/middle school age), 14 to 18 (high school), 19 to 22 (college), and 23 to 30 (adult). Injuries were classified as "accidental" if caused by dropped weight or improper equipment use. Multiple logistic regression was used to compare accidental injuries between age groups. The sample consisted of 4,111 patients. Accidental injuries decreased (p 14 to 18 > 19 to 22 years = 23 to 30 years. Conversely, sprain/strain injuries increased in each successive age group (p injuries (n = 2,565) showed that the oldest categories (19-22 and 23-30 yr) demonstrated a greater percentage of sprains and strains relative to younger age categories (p injuries sustained in the 8 to 13 group were to the hand and foot and were most often related to "dropping" and "pinching" in the injury descriptions, and there was an increased percentage of fractures in the 8 to 13 group relative to all other groups (p injuries are the result of accidents that are potentially preventable with increased supervision and stricter safety guidelines.

  16. Engineering geological mapping in Wallonia (Belgium) : present state and recent computerized approach

    Science.gov (United States)

    Delvoie, S.; Radu, J.-P.; Ruthy, I.; Charlier, R.

    2012-04-01

    An engineering geological map can be defined as a geological map with a generalized representation of all the components of a geological environment which are strongly required for spatial planning, design, construction and maintenance of civil engineering buildings. In Wallonia (Belgium) 24 engineering geological maps have been developed between the 70s and the 90s at 1/5,000 or 1/10,000 scale covering some areas of the most industrialized and urbanized cities (Liège, Charleroi and Mons). They were based on soil and subsoil data point (boring, drilling, penetration test, geophysical test, outcrop…). Some displayed data present the depth (with isoheights) or the thickness (with isopachs) of the different subsoil layers up to about 50 m depth. Information about geomechanical properties of each subsoil layer, useful for engineers and urban planners, is also synthesized. However, these maps were built up only on paper and progressively needed to be updated with new soil and subsoil data. The Public Service of Wallonia and the University of Liège have recently initiated a study to evaluate the feasibility to develop engineering geological mapping with a computerized approach. Numerous and various data (about soil and subsoil) are stored into a georelational database (the geotechnical database - using Access, Microsoft®). All the data are geographically referenced. The database is linked to a GIS project (using ArcGIS, ESRI®). Both the database and GIS project consist of a powerful tool for spatial data management and analysis. This approach involves a methodology using interpolation methods to update the previous maps and to extent the coverage to new areas. The location (x, y, z) of each subsoil layer is then computed from data point. The geomechanical data of these layers are synthesized in an explanatory booklet joined to maps.

  17. [LEGAL REGULATION OF TRANSPLANTOLOGY AT THE PRESENT STAGE: UKRAINIAN ISSUE AND EXPERIENCE OF FOREIGN STATES].

    Science.gov (United States)

    Sovgyria, O

    2018-03-01

    The objective of the research is to analyze the legal regulation in the transplantology field at the present stage in Ukraine. To address identified challenges, the author investigates the foreign countries experience and suggests ways of improving certain mechanism for legal regulation in the field of organ transplantation and anatomical materials. The empiric material of the study included a wide range of legal instruments regulating this sphere of legal relationships, information regarding the problems of their application, statistics, expert analysis of Ukrainian and foreign researchers. Methodological mechanism of current research includes such methods: systematic, logical and formal, structural-functional, comparative. The research found that the most world's successful model for the organization of transplantation is in Spain. Additionally, the criteria for the reception of such a model are singled out as well as certain aspects of their application in Ukraine are analyzed. Particularly, the most important criteria are: universal and general territorial proliferation of national health systems; relevant economic resources (special attention is paid to the fact that transplantation is not a medicine of luxury, and an adequate compensation to hospitals for transplantation operations should serve as a main economic aspect); an adequate and necessary number of doctors and nurses; the availability of advanced technical options for medical mechanical ventilation (air conditioning of dead bodies). The research led to the following overall findings. Due to the rapid development of medical and biological sciences, there is an urgent need on further investigation of legal, moral and ethical, general medical aspects of transplantation with subsequent proposals for improving legislation in the field of human organs transplantation and other anatomical materials. At the same time, development of appropriate legislation by complex groups of cross-disciplinary specialists

  18. The Institute for Nuclear Research and Nuclear Energy - present state and future prospects

    International Nuclear Information System (INIS)

    Stamenov, J.

    2004-01-01

    The Institute for Nuclear Research and Nuclear Energy is the biggest one within Bulgarian Academy of Sciences and it is a leading complex center for research and application of the nuclear physics in Bulgaria. The year 2003 was the first for the functioning of the new organization structure of INRNE consisting of 26 laboratories and 4 scientific experimental bases joined according their thematic in 7 scientific directions governed by the correspondent Expert Councils and Specialised Seminars. The scientific staff of the Institute has been worked on about 104 problems during the 2003 mainly on our traditional scientific areas, in particular, in the field of: theory of the elementary particles, field theory, atomic nuclei and quantum phenomena; experimental physics of the elementary particles, nuclear reactions, structure of atomic nuclei, cosmic rays and gamma-astrophysics at ultra high energies; neutron interactions and cross sections, physics of the fission; reactor physics, nuclear energy and nuclear safety and security ect. Now the results are already present and, as can been seen, almost half of the developments are connected with the problems of scientific support of the national nuclear energy production, radioactive waste, monitoring and management of the environment. With few exceptions, all these tasks are financially supported by national, foreign and international organizations. The fundamental end applied research results for 2003 have been accepted for publication or published in more than 300 articles in journals and proceeding of many international conferences. Large amount of these results has been obtained in close collaboration with international and foreign research centers, universities and institutions. Essential progress was obtained by the modernization of the scientific experimental bases of INRNE. The technical design project for the reconstruction of the old research reactor IRT 2000 in the new IRT 200 was successfully finished. The

  19. Nanoscale probing of bandgap states on oxide particles using electron energy-loss spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qianlang [School for the Engineering of Matter, Transport and Energy, Arizona State University, 85287 AZ (United States); March, Katia [Laboratoire de Physique des Solides, Bâtiment 510, Université Paris-Sud, 91405 Orsay Cedex (France); Crozier, Peter A., E-mail: CROZIER@asu.edu [School for the Engineering of Matter, Transport and Energy, Arizona State University, 85287 AZ (United States)

    2017-07-15

    Surface and near-surface electronic states were probed with nanometer spatial resolution in MgO and TiO{sub 2} anatase nanoparticles using ultra-high energy resolution electron energy-loss spectroscopy (EELS) coupled to a scanning transmission electron microscope (STEM). This combination allows the surface electronic structure determined with spectroscopy to be correlated with nanoparticle size, morphology, facet etc. By acquiring the spectra in aloof beam mode, radiation damage to the surface can be significantly reduced while maintaining the nanometer spatial resolution. MgO and TiO{sub 2} showed very different bandgap features associated with the surface/sub-surface layer of the nanoparticles. Spectral simulations based on dielectric theory and density of states models showed that a plateau feature found in the pre-bandgap region in the spectra from (100) surfaces of 60 nm MgO nanocubes is consistent with a thin hydroxide surface layer. The spectroscopy shows that this hydroxide species gives rise to a broad filled surface state at 1.1 eV above the MgO valence band. At the surfaces of TiO{sub 2} nanoparticles, pronounced peaks were observed in the bandgap region, which could not be well fitted to defect states. In this case, the high refractive index and large particle size may make Cherenkov or guided light modes the likely causes of the peaks. - Highlights: • Bandgap states detected with aloof beam monochromated EELS on oxide nanoparticle surfaces. • Dielectric theory applied to simulate the spectra and interpret surface structure. • Density of states models also be employed to understand the surface electronic structure. • In MgO, one states associate with water species was found close to the valence band edge. • In anatase, two mid-gap states associated with point defects were found.

  20. Adsorption of CO, CO2, H2, and H2O on titania surfaces with different oxidation states

    International Nuclear Information System (INIS)

    Raupp, G.B.; Dumesic, J.A.

    1985-01-01

    The adsorptive properties of titania surfaces with different oxidation states were proved by temperature-programmed desorption (TPD) of CO, H 2 , CO 2 , and H 2 O. Auger electron spectroscopy and X-ray photoelectron spectroscopy revealed that vacuum annealing an oxidized titanium foil at temperatures from 300 to 800 K was an effective means of systematically varying the average surface oxidation state from Ti 4+ to Ti 2+ . Carbon monoxide weakly adsorbed (desorption energy of 44-49 kJ x mol -1 ) in a carbonyl fashion on coordinatively unsaturated cation sites. Titania surfaces were inert with respect to H 2 adsorption and dissociation. Carbon dioxide adsorbed in a linear molecular fashion. Water adsorbed both molecularly and dissociatively. Results are discussed in terms of the role of titania oxidation state in CO hydrogenation over titania-supported metal catalysts. 74 references, 7 figures

  1. Youth Versus Adult “Weightlifting” Injuries Presenting to United States Emergency Rooms: Accidental Versus Nonaccidental Injury Mechanisms

    OpenAIRE

    Myer, Gregory D.; Quatman, Carmen E.; Khoury, Jane; Wall, Eric J.; Hewett, Timothy E.

    2009-01-01

    Myer, GD, Quatman, CE, Khoury, J, Wall, EJ, and Hewett, TE. Youth versus adult “weightlifting” injuries presenting to united states emergency rooms: accidental versus nonaccidental injury mechanisms. J Strength Cond Res 23(7): 2054–2060, 2009—Resistance training has previously been purported to be unsafe and ineffective in children. The purpose of this investigation was to evaluate resistance training-related injuries presenting to U.S. emergency rooms by age, type, and mechanism of injury. W...

  2. The effect of interfaces on solid-state reactions between oxides

    International Nuclear Information System (INIS)

    Johnson, M.T.; Carter, C.B.

    1998-01-01

    A thin-film geometry has been used to study fundamental solid-state reaction processes occurring at interfaces in two spinel-forming oxide systems. In the first system, NiO/Al 2 O 3 , epitactic NiO films were deposited on various orientations of single-crystal α-Al 2 O 3 . In this case, the reaction kinetics were studied and correlated with the interfacial structure (or substrate orientation). In the second, In 2 O 3 /MgO, solid-state reactions were studied under the influence of an electric field. The electric field provides a driving force for mass transport that affects both the reaction process and the morphological stability of an interface

  3. Chemical states of fission products in irradiated uranium-plutonium mixed oxide fuel

    International Nuclear Information System (INIS)

    Kurosaki, Ken; Uno, Masayoshi; Yamanaka, Shinsuke

    1999-01-01

    The chemical states of fission products (FPs) in irradiated uranium-plutonium mixed oxide (MOX) fuel for the light water reactor (LWR) were estimated by thermodynamic equilibrium calculations on system of fuel and FPs by using ChemSage program. A stoichiometric MOX containing 6.1 wt. percent PuO 2 was taken as a loading fuel. The variation of chemical states of FPs was calculated as a function of oxygen potential. Some pieces of information obtained by the calculation were compared with the results of the post-irradiation examination (PIE) of UO 2 fuel. It was confirmed that the multicomponent and multiphase thermodynamic equilibrium calculation between fuel and FPs system was an effective tool for understanding the behavior of FPs in fuel. (author)

  4. Origin of major donor states in In–Ga–Zn oxide

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Motoki; Oota, Masashi; Ishihara, Noritaka; Nonaka, Yusuke; Hirohashi, Takuya; Takahashi, Masahiro; Yamazaki, Shunpei [Semiconductor Energy Laboratory Co., Ltd., 398 Hase, Atsugi, Kanagawa 243-0036 (Japan); Obonai, Toshimitsu; Hosaka, Yasuharu; Koezuka, Junichi [Advanced Film Device Inc., 161-2 Masuzuka, Tsuga-machi, Tochigi, Tochigi 328-0114 (Japan)

    2014-12-07

    To clarify the origin of the major donor states in indium gallium zinc oxide (IGZO), we report measurement results and an analysis of several physical properties of IGZO thin films. Specifically, the concentration of H atoms and O vacancies (V{sub O}), carrier concentration, and conductivity are investigated by hard X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, thermal desorption spectroscopy, and Hall effect measurements. The results of these experiments suggest that the origin of major donor states is H occupancy of V{sub O} sites. Furthermore, we use first-principles calculations to investigate the influence of the coexistence of V{sub O} and H in crystalline InGaO{sub 3}(ZnO){sub m} (m = 1). The results indicate that when H is trapped in V{sub O}, a stable complex is created that serves as a shallow-level donor.

  5. Solid-State Electrochromic Device Consisting of Amorphous WO3 and Various Thin Oxide Layers

    Science.gov (United States)

    Shizukuishi, Makoto; Shimizu, Isamu; Inoue, Eiichi

    1980-11-01

    A mixed oxide containing Cr2O3 was introduced into an amorphous WO3 solid-state electrochromic device (ECD) in order to improve its colour memory effect. The electrochromic characteristics were greatly affected by the chemical constituents of a dielectric layer on the a-WO3 layer. Particularly, long memory effect and low power dissipation were attained in a solid-state ECD consisting of a-WO3 and Cr2O3\\cdotV2O5(50 wt.%). Some electrochromic characteristics of the a-WO3/Cr2O3\\cdotV2O5 ECD and the role of V2O5 were investigated.

  6. Long-living positron and positronium states in zeolites and microcrystalline oxides

    International Nuclear Information System (INIS)

    Kajcsos, Zs.; Liszkay, L.; Varga, L.; Lohonyai, L.; Lazar, K.

    1995-01-01

    Positron annihilation (PA) investigation were performed on zeolites (X, Y and ZSM-5) and on microcrystalline MgO, Al 2 O 3 and SiO 2 , providing long lifetime components attributed to o-Ps atoms. In addition to the positron lifetime (LT) measurements, the energy distribution (ED) of the annihilation gamma radiation spectrum was recorded in the 30 keV - 1.5 MeV range for different samples and was compared to reference distributions for Si and GaAs samples, where no long-living Ps states are formed. Apart from the strong correlation with the water content in the samples, the positron data collected testify much more pronounced positronium hosting features for powders of the mentioned oxides than for zeolites. Positron LT spectroscopy combined with recording of the ED of the annihilation radiation provides reliable information on the forming of long living 3γ states. (author) 15 refs.; 4 figs

  7. The state of itinerant charge carriers and thermoelectric effects in correlated oxide metals

    International Nuclear Information System (INIS)

    Kuzemsky, A.L.; Abdus Salam International Centre for Theoretical Physics, Trieste

    2000-10-01

    We analyzed the physics of transport processes and, in particular, the thermoelectric power in the mercurocuprates and other cuprates to get a better insight into the state of the carriers in these compounds. The actual problems related to the complicated mechanisms of carriers scattering above Tc are discussed. The experimental studies of thermoelectric power showed that the state of carriers in cuprates can be influenced by many complicated scattering processes, however the underlying mechanism for the linear decreasing of the TEP with increasing the temperature for most hole-doped HTSC cuprates is still not yet known. The actual problems related to the complicated mechanisms of carriers scattering above Tc are discussed for a few models of charge transport. A comparison between the analytical and experimental results is also made. It is concluded that the crucial factor for the understanding of the transport properties of correlated oxide metals is the nature of itinerant charge carriers, i.e. renormalized quasiparticles. (author)

  8. Probing the transition state region in catalytic CO oxidation on Ru

    Energy Technology Data Exchange (ETDEWEB)

    Ostrom, H. [Stockholm Univ. (Sweden); Oberg, H. [Stockholm Univ. (Sweden); Xin, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); LaRue, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Beye, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Helmholtz Zentrum Berlin fur Materialien und Energie GmbH, Berlin (Germany); Dell' Angela, M. [Univ. of Hamburg and Center for Free Electron Laser Science, Hamburg (Germany); Gladh, J. [Stockholm Univ. (Sweden); Ng, M. L. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Sellberg, J. A. [Stockholm Univ. (Sweden); SLAC National Accelerator Lab., Menlo Park, CA (United States); Kaya, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Mercurio, G. [Univ. of Hamburg and Center for Free Electron Laser Science, Hamburg (Germany); Nordlund, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hantschmann, M. [Helmholtz Zentrum Berlin fur Materialien und Energie GmbH, Berlin (Germany); Hieke, F. [Univ. of Hamburg and Center for Free Electron Laser Science, Hamburg (Germany); Kuhn, D. [Helmholtz Zentrum Berlin fur Materialien und Energie GmbH, Berlin (Germany); Schlotter, W. F. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Dakovski, G. L. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Turner, J. J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Minitti, M. P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Mitra, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Moeller, S. P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fohlisch, A. [Helmholtz Zentrum Berlin fur Materialien und Energie GmbH, Berlin (Germany); Univ. Potsdam, Potsdam (Germany); Wolf, M. [Fritz-Haber Institute of the Max-Planck-Society, Berlin (Germany); Wurth, W. [Univ. of Hamburg and Center for Free Electron Laser Science, Hamburg (Germany); DESY Photon Science, Hamburg (Germany); Persson, M. [The Univ. of Liverpool, Liverpool (United Kingdom); Norskov, J. K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Abild-Pedersen, F. [Stanford Univ., Stanford, CA (United States); Ogasawara, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Pettersson, L. G. M. [Stockholm Univ. (Sweden); Nilsson, A. [Stockholm Univ. (Sweden); SLAC National Accelerator Lab., Menlo Park, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-02-12

    Femtosecond x-ray laser pulses are used to probe the CO oxidation reaction on ruthenium (Ru) initiated by an optical laser pulse. On a time scale of a few hundred femtoseconds, the optical laser pulse excites motions of CO and O on the surface, allowing the reactants to collide, and, with a transient close to a picosecond (ps), new electronic states appear in the O K-edge x-ray absorption spectrum. Density functional theory calculations indicate that these result from changes in the adsorption site and bond formation between CO and O with a distribution of OC–O bond lengths close to the transition state (TS). After 1 ps, 10% of the CO populate the TS region, which is consistent with predictions based on a quantum oscillator model.

  9. Steady-state oxidation of cholesterol catalyzed by cholesterol oxidase in lipid bilayer membranes on platinum electrodes

    International Nuclear Information System (INIS)

    Bokoch, Michael P.; Devadoss, Anando; Palencsar, Mariela S.; Burgess, James D.

    2004-01-01

    Cholesterol oxidase is immobilized in electrode-supported lipid bilayer membranes. Platinum electrodes are initially modified with a self-assembled monolayer of thiolipid. A vesicle fusion method is used to deposit an outer leaflet of phospholipids onto the thiolipid monolayer forming a thiolipid/lipid bilayer membrane on the electrode surface. Cholesterol oxidase spontaneously inserts into the electrode-supported lipid bilayer membrane from solution and is consequently immobilized to the electrode surface. Cholesterol partitions into the membrane from buffer solutions containing cyclodextrin. Cholesterol oxidase catalyzes the oxidation of cholesterol by molecular oxygen, forming hydrogen peroxide as a product. Amperometric detection of hydrogen peroxide for continuous solution flow experiments are presented, where flow was alternated between cholesterol solution and buffer containing no cholesterol. Steady-state anodic currents were observed during exposures of cholesterol solutions ranging in concentration from 10 to 1000 μM. These data are consistent with the Michaelis-Menten kinetic model for oxidation of cholesterol as catalyzed by cholesterol oxidase immobilized in the lipid bilayer membrane. The cholesterol detection limit is below 1 μM for cholesterol solution prepared in buffered cyclodextrin. The response of the electrodes to low density lipoprotein solutions is increased upon addition of cyclodextrin. Evidence for adsorption of low density lipoprotein to the electrode surface is presented

  10. Perspectives on the Present State and Future of Higher Education Faculty Development in Kazakhstan: Implications for National Human Resource Development

    Science.gov (United States)

    Seitova, Dinara

    2016-01-01

    The article aims at examining the present state of higher education faculty development in Kazakhstan in the context of multidimensional nationwide development reforms and exploring implications for the National Human Resource Development of the country. For the purpose of this research, theoretical human resource development (HRD) and…

  11. School-Based Mental Health Programs in the United States: Present Status and a Blueprint for the Future.

    Science.gov (United States)

    Pfeiffer, Steven I.; Reddy, Linda A.

    1998-01-01

    Provides overview of sociocultural and political factors in the United States that have influenced recent interest in school-based health and mental health programs. Describes four well-known programs and presents a new framework, the Tripartite Model of School-Based Mental Health Interventions, to stimulate thinking on future programs. Addresses…

  12. Present status of solid state photoelectrochemical solar cells and dye sensitized solar cells using PEO-based polymer electrolytes

    International Nuclear Information System (INIS)

    Singh, Pramod Kumar; Bhattacharya, Bhaskar; Nagarale, R K; Pandey, S P; Rhee, H W

    2011-01-01

    Due to energy crises in the future, much effort is being directed towards alternate sources. Solar energy is accepted as a novel substitute for conventional sources of energy. Out of the long list of various types of solar cells available on the market, solid state photoelectrochemical solar cells (SSPECs) and dye sensitized solar cells (DSSCs) are proposed as an alternative to costly crystalline solar cell. This review provides a common platform for SSPECs and DSSCs using polymer electrolyte, particularly on polyethylene oxide (PEO)-based polymer electrolytes. Due to numerous advantageous properties of PEO, it is frequently used as an electrolyte in both SSPECs as well as DSSCs. In DSSCs, so far high efficiency (more than 11%) has been obtained only by using volatile liquid electrolyte, which suffers many disadvantages, such as corrosion, leakage and evaporation. The PEO-based solid polymer proves its importance and could be used to solve the problems stated above. The recent developments in SSPECs and DSSCs using modified PEO electrolytes by adding nano size inorganic fillers, blending with low molecular weight polymers and ionic liquid (IL) are discussed in detail. The role of ionic liquid in modifying the electrical, structural and photoelectrochemical properties of PEO polymer electrolytes is also described. (review)

  13. Present status of solid state photoelectrochemical solar cells and dye sensitized solar cells using PEO-based polymer electrolytes

    Science.gov (United States)

    Singh, Pramod Kumar; Nagarale, R. K.; Pandey, S. P.; Rhee, H. W.; Bhattacharya, Bhaskar

    2011-06-01

    Due to energy crises in the future, much effort is being directed towards alternate sources. Solar energy is accepted as a novel substitute for conventional sources of energy. Out of the long list of various types of solar cells available on the market, solid state photoelectrochemical solar cells (SSPECs) and dye sensitized solar cells (DSSCs) are proposed as an alternative to costly crystalline solar cell. This review provides a common platform for SSPECs and DSSCs using polymer electrolyte, particularly on polyethylene oxide (PEO)-based polymer electrolytes. Due to numerous advantageous properties of PEO, it is frequently used as an electrolyte in both SSPECs as well as DSSCs. In DSSCs, so far high efficiency (more than 11%) has been obtained only by using volatile liquid electrolyte, which suffers many disadvantages, such as corrosion, leakage and evaporation. The PEO-based solid polymer proves its importance and could be used to solve the problems stated above. The recent developments in SSPECs and DSSCs using modified PEO electrolytes by adding nano size inorganic fillers, blending with low molecular weight polymers and ionic liquid (IL) are discussed in detail. The role of ionic liquid in modifying the electrical, structural and photoelectrochemical properties of PEO polymer electrolytes is also described.

  14. Obesity-Associated Oxidative Stress: Strategies Finalized to Improve Redox State

    Directory of Open Access Journals (Sweden)

    Valeria Gasperi

    2013-05-01

    Full Text Available Obesity represents a major risk factor for a plethora of severe diseases, including diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and cancer. It is often accompanied by an increased risk of mortality and, in the case of non-fatal health problems, the quality of life is impaired because of associated conditions, including sleep apnea, respiratory problems, osteoarthritis, and infertility. Recent evidence suggests that oxidative stress may be the mechanistic link between obesity and related complications. In obese patients, antioxidant defenses are lower than normal weight counterparts and their levels inversely correlate with central adiposity; obesity is also characterized by enhanced levels of reactive oxygen or nitrogen species. Inadequacy of antioxidant defenses probably relies on different factors: obese individuals may have a lower intake of antioxidant- and phytochemical-rich foods, such as fruits, vegetables, and legumes; otherwise, consumption of antioxidant nutrients is normal, but obese individuals may have an increased utilization of these molecules, likewise to that reported in diabetic patients and smokers. Also inadequate physical activity may account for a decreased antioxidant state. In this review, we describe current concepts in the meaning of obesity as a state of chronic oxidative stress and the potential interventions to improve redox balance.

  15. Obesity-Associated Oxidative Stress: Strategies Finalized to Improve Redox State

    Science.gov (United States)

    Savini, Isabella; Catani, Maria Valeria; Evangelista, Daniela; Gasperi, Valeria; Avigliano, Luciana

    2013-01-01

    Obesity represents a major risk factor for a plethora of severe diseases, including diabetes, cardiovascular disease, non-alcoholic fatty liver disease, and cancer. It is often accompanied by an increased risk of mortality and, in the case of non-fatal health problems, the quality of life is impaired because of associated conditions, including sleep apnea, respiratory problems, osteoarthritis, and infertility. Recent evidence suggests that oxidative stress may be the mechanistic link between obesity and related complications. In obese patients, antioxidant defenses are lower than normal weight counterparts and their levels inversely correlate with central adiposity; obesity is also characterized by enhanced levels of reactive oxygen or nitrogen species. Inadequacy of antioxidant defenses probably relies on different factors: obese individuals may have a lower intake of antioxidant- and phytochemical-rich foods, such as fruits, vegetables, and legumes; otherwise, consumption of antioxidant nutrients is normal, but obese individuals may have an increased utilization of these molecules, likewise to that reported in diabetic patients and smokers. Also inadequate physical activity may account for a decreased antioxidant state. In this review, we describe current concepts in the meaning of obesity as a state of chronic oxidative stress and the potential interventions to improve redox balance. PMID:23698776

  16. Oxidation state of sulfur, iron and tin at the surface of float glasses

    International Nuclear Information System (INIS)

    Lagarde, P; Flank, A-M; Jupille, J; Montigaud, H

    2009-01-01

    Sulfur is an important element of glasses, not because of its amount, always very low (less than 0.4 % in weight of SO 3 ), but because of its role since it actively participates to the refinement process and, combined to other elements, it can be responsible for the coloration of the glass. Iron is also of a major importance in most of the glasses. In the case of the float glass, the two faces, because of the fabrication process, are different in terms of composition (presence of Sn for one face) and also in terms of oxidation state of these minority elements (Fe, Sn, S). There should be a subtle interplay between the concentrations and the oxidation states of these different minority elements, and anyway these variations occur over a thickness of the order of few micrometers below the surface. Using the high intensity and the focusing properties (3 x 3 μm 2 ) of the x-ray beam from the Lucia beamline, we have therefore studied the speciation of iron and sulfur near the face of a float glass in relation with the behavior of tin. This has been obtained by combining elemental x-ray fluorescence cartography and x-ray micro-absorption at the different K-edges.

  17. Oxidation state of sulfur, iron and tin at the surface of float glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lagarde, P; Flank, A-M [Synchrotron SOLEIL, l' Orme des Merisiers, BP 48 91192 Gif/Yvette cedex (France); Jupille, J [IMPMC, Universite P. and M. Curie, Campus de Boucicaut, 140 rue de Lourmel 75015 Paris (France); Montigaud, H [Saint-Gobain Recherche 39, quai Lucien Lefranc, BP 135 93303 Aubervilliers Cedex (France)

    2009-11-15

    Sulfur is an important element of glasses, not because of its amount, always very low (less than 0.4 % in weight of SO{sub 3}), but because of its role since it actively participates to the refinement process and, combined to other elements, it can be responsible for the coloration of the glass. Iron is also of a major importance in most of the glasses. In the case of the float glass, the two faces, because of the fabrication process, are different in terms of composition (presence of Sn for one face) and also in terms of oxidation state of these minority elements (Fe, Sn, S). There should be a subtle interplay between the concentrations and the oxidation states of these different minority elements, and anyway these variations occur over a thickness of the order of few micrometers below the surface. Using the high intensity and the focusing properties (3 x 3 {mu}m{sup 2}) of the x-ray beam from the Lucia beamline, we have therefore studied the speciation of iron and sulfur near the face of a float glass in relation with the behavior of tin. This has been obtained by combining elemental x-ray fluorescence cartography and x-ray micro-absorption at the different K-edges.

  18. Effect of surface state on the oxidation behavior of welded 308L in simulated nominal primary water of PWR

    Science.gov (United States)

    Ming, Hongliang; Zhang, Zhiming; Wang, Jiazhen; Zhu, Ruolin; Ding, Jie; Wang, Jianqiu; Han, En-Hou; Ke, Wei

    2015-05-01

    The oxidation behavior of 308L weld metal (WM) with different surface state in the simulated nominal primary water of pressurized water reactor (PWR) was studied by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) analyzer and X-ray photoelectron spectroscopy (XPS). After 480 h immersion, a duplex oxide film composed of a Fe-rich outer layer (Fe3O4, Fe2O3 and a small amount of NiFe2O4, Ni(OH)2, Cr(OH)3 and (Ni, Fe)Cr2O4) and a Cr-rich inner layer (FeCr2O4 and NiCr2O4) can be formed on the 308L WM samples with different surface state. The surface state has no influence on the phase composition of the oxide films but obviously affects the thickness of the oxide films and the morphology of the oxides (number & size). With increasing the density of dislocations and subgrain boundaries in the cold-worked superficial layer, the thickness of the oxide film, the number and size of the oxides decrease.

  19. In-situ preparation of poly(ethylene oxide)/Li3PS4 hybrid polymer electrolyte with good nanofiller distribution for rechargeable solid-state lithium batteries

    Science.gov (United States)

    Chen, Shaojie; Wang, Junye; Zhang, Zhihua; Wu, Linbin; Yao, Lili; Wei, Zhenyao; Deng, Yonghong; Xie, Dongjiu; Yao, Xiayin; Xu, Xiaoxiong

    2018-05-01

    Nano-sized fillers in a polymer matrix with good distribution can play a positive role in improving polymer electrolytes in the aspects of ionic conductivity, mechanical property and electrochemical performance of Li-ion cells. Herein, polyethylene oxide (PEO)/Li3PS4 hybrid polymer electrolyte is prepared via a new in-situ approach. The ionic conductivities of the novel hybrid electrolytes with variable proportions are measured, and the optimal electrolyte of PEO-2%vol Li3PS4 presents a considerable ionic conductivity of 8.01 × 10-4 S cm-1 at 60 °C and an electrochemical window up to 5.1 V. The tests of DSC and EDXS reveal that the Li3PS4 nanoparticles with better distribution, as active fillers scattering in the PEO, exhibit a positive effect on the transference of lithium ion and electrochemical interfacial stabilities. Finally, the assembled solid-state LiFePO4/Li battery presents a decent cycling performance (80.9% retention rate after 325 cycles at 60 °C) and excellent rate capacities with 153, 143, 139 and 127 mAh g-1 at the discharging rate of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C. It is fully proved that it is an advanced strategy to preparing the new organic/inorganic hybrid electrolytes for lithium-ion batteries applications.

  20. United States panel presentations

    International Nuclear Information System (INIS)

    Wolfe, B.

    1990-01-01

    According to studies by the Department of Energy, toward the latter part of this decade, we will have to add five or six baseload plants, and in the period from 2000 to 205, we are going to need some sixty additional baseload plants. So in the next fifteen years we will need some sixty-five or seventy baseload plants. One can argue over the accuracy of those numbers, but tens of new baseload plants are going to be needed, and that means we are going to have to start the design of these plants in the next few years to get them online by the end of the century. I think there is going to be a change in attitude towards new plants. My view is that when the American public is faced with the decision of what kind of new energy source they need versus 'do I let the lights dim?', that nuclear power will be one of their choices. We will see as a result the revival of nuclear power - the water reactors in the near term, and I will leave for later discussion the question of whether we will use breeders and gas-cooled reactors for the longer term

  1. United States panel presentations

    International Nuclear Information System (INIS)

    Young, H.

    1990-01-01

    The Department of Energy is supporting a number of programs directed at improving nuclear power's ability to compete by the mid 1990s in providing some of what will be urgently needed new baseload capacity, and at meeting both utility requirements and public goals. More specifically, we are co-funding demonstration by 1993 of the process for life extension of current nuclear plants. We are supporting the development of new ALWR designs which rely more on methods such as natural circulation, gravity, reduced power density, or the characteristics of materials, rather than engineered systems to provide safety. These designs will meet the criteria set forth in EPRI's Utility Requirements Documents. We have established a cost-sharing program to demonstrate the success of the nuclear plant standardization and licensing process by obtaining NRC certification by 1992 or 1993 of two evolutionary 1300MWe ALWR designs. We are also cost-sharing a program to certify by 1995 passively safe 600MWe ALWRs employing more natural safety features and modular construction. These programs will involve a rule-making hearing process. We are supporting the development and possible certification early in the next century of modular high temperature gas reactor and advanced liquid metal reactor plant designs. We are planning to demonstrate the early site approval licensing process through a cost-sharing arrangement with the private sector by 1995. In developing the National Energy Strategy, we are examining the issue of a fully satisfactory regulatory process, including the possibility of legislation codifying 10 CFR Part 52, limiting the possible delays associated with a potential second hearing and dealing with emergency planning issues before start of construction. We recently announced a restructured plan to develop a permanent waste repository by 2010. By 1995 we expect to have made significant progress in evaluating the suitability of Yucca Mountain. We expect to have selected a monitored retrievable storage site and submitted a license application to the NRC, pointing toward first operation of an MRS facility in 1998. Also on the waste front, we are beginning to study recycling of actinides in spent nuclear fuel to possibly benefit future long-term nuclear waste management. We will encourage and support an effective dialogue with the public on the benefits and risks of nuclear power relative to other alternatives

  2. United States panel presentations

    International Nuclear Information System (INIS)

    Kadak, A.C.

    1990-01-01

    I think, as a priority before we can move forward with new plants, from a public perception standpoint, we are going to have to do something credible about wastes. I am very optimistic now that the National Research Council has said that the existing waste disposal criteria and standards are not credible, that they are unattainable because technically we cannot prove that a technical scheme will continue to work far into the future. It is time for us to get back and figure out what we can demonstrate to be true in order to show people that the repository siting process we are about to go through is, in fact, credible. I think no new reactor design is going to be purchased unless the safety regulatory system is changed. I am not talking about design standardization here. I am talking about a basic review of all the rules and regulations in order to determine whether they are doing anything productive. The current set of rules and regulations is immense. Many of them are no longer relevant or current. That has to be changed rather dramatically. I think we are only treating the symptoms of our problems if we think that standardization, or one-step licensing, will solve them. The rules also apply after the plant starts up as well, and that is where those of us who operate nuclear power plants are now suffering. Clearly, one of the things that is obvious for the future of nuclear power is that we must maintain good operations. I think if you were to take a realistic look, in the next five or ten years, you would probably see more of an evolutionary design than a revolutionary design being used in actual practice. My sense is that if we continue to operate our plants well, public support will be there. Clearly we do not need any more Three Mile Islands to occur in this country

  3. Determination of the specific surface energy of oxides and glasses in the solid-state

    International Nuclear Information System (INIS)

    Andryushechkin, S.; Karpman, M.

    2000-01-01

    The production and application of coatings on glasses are used widely in technology. The coatings on glass are used for the regulation of optical, decorative, conducting and other technological and physical properties of glass. In particular, it is important to mention the application of glass fibres for the development of composite materials. However, the specific surface energy of glass and, consequently, its adhesion characteristics are relatively low. The values of these characteristics can be changed by the application of different metallic and nonmetallic coatings is characterised by high surface energy. To produce metallic coatings with the required adhesion strength of glass, it is necessary to have information on the specific surface energy of inorganic glass of different chemical composition. The determination of the relationships between the properties and composition of glass is one of the fundamental problems. At present, a large amount of investigations have been carried out into the investigations of the properties of glass in relation to its composition. However, the problem of establishment of relationships between the properties and composition of glass are especially difficult when examining multicomponent systems (technical glass). It is therefore, in to analyse in each case the properties of not the entire system has a whole but the variation of the properties with temperature of the individual components included in the system, the subsequent application of the additivity principle. The large majority of the glasses represent combinations of oxides of the elements of groups I-III and oxides of the transition metals, forming the mixtures, solid solutions of chemical compounds in the glass production process. Thus, analysis of the characteristics of oxides of the alkali, alkali-earth and transition metals makes it possible to obtain initial data for the evaluation of the surface energy, density, molecular mass of glass containing these oxides

  4. Cellulose nanofibril/reduced graphene oxide/carbon nanotube hybrid aerogels for highly flexible and all-solid-state supercapacitors

    Science.gov (United States)

    Qifeng Zheng; Zhiyong Cai; Zhenqiang Ma; Shaoqin Gong

    2015-01-01

    A novel type of highly flexible and all-solid-state supercapacitor that uses cellulose nanofibril (CNF)/reduced graphene oxide (RGO)/carbon nanotube (CNT) hybrid aerogels as electrodes and H2SO4 poly (vinyl alcohol) PVA gel as the electrolyte was developed and is reported here. These flexible solid-state supercapacitors...

  5. Synthesis and Electrochemistry of Li3MnO4: Mn in the +5 OxidationState

    Energy Technology Data Exchange (ETDEWEB)

    Saint, Juliette.A.; Doeff, Marca M.; Reed, John

    2007-06-19

    Computational and experimental work directed at exploringthe electrochemical properties of tetrahedrally coordinated Mn in the +5oxidation state is presented. Specific capacities of nearly 700 mAh/g arepredicted for the redox processes of LixMnO4 complexes based on twotwo-phase reactions. One is topotactic extractionof Li from Li3MnO4 toform LiMnO4 and the second is topotactic insertion of Li into Li3MnO4 toform Li5MnO4. In experiments, it is found that the redox behavior ofLi3MnO4 is complicated by disproportionation of Mn5+ in solution to formMn4+ and Mn7+ and byother irreversible processes; although an initialcapacity of about 275 mAh/g in lithiumcells was achieved. Strategiesbased on structural considerations to improve the electrochemicalproperties of MnO4n- complexes are given.

  6. Final Report for research grant "Development of Methods for High Specific Activity Labeling of Biomolecules Using Astatine-211 in Different Oxidation States"

    Energy Technology Data Exchange (ETDEWEB)

    Wilbur, D. Scott [Univ. of Washington, Seattle, WA (United States)

    2011-12-14

    The overall objective of this research effort was to develop methods for labeling biomolecules with higher oxidation state species of At-211. This was to be done in an effort to develop reagents that had higher in vivo stability than the present carbon-bonded At-211-labeled compounds. We were unsuccessful in that effort, as none of the approaches studied provided reagents that were stable to in vivo deastatination. However, we gained a lot of information about At-211 in higher oxidation states. The studies proved to be very difficult as small changes in pH and other conditions appeared to change the nature of the species that obtained (by HPLC retention time analyses), with many of the species being unidentifiable. The fact that there are no stable isotopes of astatine, and the chemistry of the nearest halogen iodine is quite different, made it very difficult to interpret results of some experiments. With that said, we believe that a lot of valuable information was obtained from the studies. The research effort evaluated: (1) methods for chemical oxidation of At-211, (2) approaches to chelation of oxidized At-211, and (3) approaches to oxidation of astatophenyl compounds. A major hurdle that had to be surmounted to conduct the research was the development of HPLC conditions to separate and identify the various oxidized species formed. Attempts to develop conditions for separation of iodine and astatine species by normal and reversed-phase TLC and ITLC were not successful. However, we were successful in developing conditions (from a large number of attempts) to separate oxidized forms of iodine ([I-125]iodide, [I-125]iodate and [I-125]periodate) and astatine ([At-211]astatide, [At-211]astatate, [At-211]perastatate, and several unidentified At-211 species). Information on the basic oxidation and characterization of At-211 species is provided under Objective 1. Conditions were developed to obtain new At-211 labeling method where At-211 is chelated with the DOTA and

  7. Quantum State-Resolved Collision Dynamics of Nitric Oxide at Ionic Liquid and Molten Metal Surfaces

    Science.gov (United States)

    Zutz, Amelia Marie

    Detailed molecular scale interactions at the gas-liquid interface are explored with quantum state-to-state resolved scattering of a jet-cooled beam of NO(2pi1/2; N = 0) from ionic liquid and molten metal surfaces. The scattered distributions are probed via laser-induced fluorescence methods, which yield rotational and spin-orbit state populations that elucidate the dynamics of energy transfer at the gas-liquid interface. These collision dynamics are explored as a function of incident collision energy, surface temperature, scattering angle, and liquid identity, all of which are found to substantially affect the degree of rotational, electronic and vibrational excitation of NO via collisions at the liquid surface. Rotational distributions observed reveal two distinct scattering pathways, (i) molecules that trap, thermalize and eventually desorb from the surface (trapping-desorption, TD), and (ii) those that undergo prompt recoil (impulsive scattering, IS) prior to complete equilibration with the liquid surface. Thermally desorbing NO molecules are found to have rotational temperatures close to, but slightly cooler than the surface temperature, indicative of rotational dependent sticking probabilities on liquid surfaces. Nitric oxide is a radical with multiple low-lying electronic states that serves as an ideal candidate for exploring nonadiabatic state-changing collision dynamics at the gas-liquid interface, which induce significant excitation from ground (2pi1/2) to excited (2pi 3/2) spin-orbit states. Molecular beam scattering of supersonically cooled NO from hot molten metals (Ga and Au, Ts = 300 - 1400 K) is also explored, which provide preliminary evidence for vibrational excitation of NO mediated by thermally populated electron-hole pairs in the hot, conducting liquid metals. The results highlight the presence of electronically nonadiabatic effects and build toward a more complete characterization of energy transfer dynamics at gas-liquid interfaces.

  8. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries.

    Science.gov (United States)

    Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

    2016-12-23

    Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn 4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g -1 based on solid-state redox reaction of oxide ions.

  9. Origin of stabilization and destabilization in solid-state redox reaction of oxide ions for lithium-ion batteries

    Science.gov (United States)

    Yabuuchi, Naoaki; Nakayama, Masanobu; Takeuchi, Mitsue; Komaba, Shinichi; Hashimoto, Yu; Mukai, Takahiro; Shiiba, Hiromasa; Sato, Kei; Kobayashi, Yuki; Nakao, Aiko; Yonemura, Masao; Yamanaka, Keisuke; Mitsuhara, Kei; Ohta, Toshiaki

    2016-01-01

    Further increase in energy density of lithium batteries is needed for zero emission vehicles. However, energy density is restricted by unavoidable theoretical limits for positive electrodes used in commercial applications. One possibility towards energy densities exceeding these limits is to utilize anion (oxide ion) redox, instead of classical transition metal redox. Nevertheless, origin of activation of the oxide ion and its stabilization mechanism are not fully understood. Here we demonstrate that the suppression of formation of superoxide-like species on lithium extraction results in reversible redox for oxide ions, which is stabilized by the presence of relatively less covalent character of Mn4+ with oxide ions without the sacrifice of electronic conductivity. On the basis of these findings, we report an electrode material, whose metallic constituents consist only of 3d transition metal elements. The material delivers a reversible capacity of 300 mAh g−1 based on solid-state redox reaction of oxide ions. PMID:28008955

  10. Role of the oxidation state of cerium on the ceria surfaces for silicate adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jihoon [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Moon, Jinok [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Clean/CMP Technology Team, Memory, Samsung Electronics, Hwaseong (Korea, Republic of); Kim, Joo Hyun; Lee, Kangchun [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Hwang, Junha [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Materials R& D Center, K.C.Tech, Anseong (Korea, Republic of); Yoon, Heesung [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of); Yi, Dong Kee, E-mail: vitalis@mju.ac.kr [Department of Chemistry, Myongji University, Yongin (Korea, Republic of); Paik, Ungyu, E-mail: upaik@hanyang.ac.kr [WCD Department of Energy Engineering, Hanyang University, Seoul (Korea, Republic of)

    2016-12-15

    Highlights: • We investigated the role of Ce oxidation state (Ce{sup 3+}/Ce{sup 4+}) on the CeO{sub 2} surfaces for the silicate adsorption. • As the Ce{sup 3+} concentration increased from 19.3 to 27.6%, the surface density of −OH group increased from 0.34 to 0.72 OH/nm{sup 2}. • The Freundlich constant for the relative adsorption capacity (K{sub F}) and adsorption intensity (1/n) indicated that CeO{sub 2} NPs with high Ce{sup 3+} concentration show higher adsorption affinity with silicate ions. - Abstract: In this study, we have investigated the role of the Ce oxidation state (Ce{sup 3+}/Ce{sup 4+}) on the CeO{sub 2} surfaces for silicate adsorption. In aqueous medium, the Ce{sup 3+} sites lead to the formation of −OH groups at the CeO{sub 2} surface through H{sub 2}O dissociation. Silicate ions can adsorb onto the CeO{sub 2} surface through interaction with the −OH groups (−Ce−OH− + −Si−O{sup −} ↔ −Ce−O−Si− + OH{sup −}). As the Ce{sup 3+} concentration increased from 19.3 to 27.6%, the surface density of −OH group increased from 0.34 to 0.72 OH/nm{sup 2}. To evaluate the adsorption behaviors of silicate ions onto CeO{sub 2} NPs, we carried out an adsorption isothermal analysis, and the adsorption isotherm data followed the Freundlich model. The Freundlich constant for the relative adsorption capacity (K{sub F}) and adsorption intensity (1/n) indicated that CeO{sub 2} NPs with high Ce{sup 3+} concentration show higher adsorption affinity with silicate ions. As a result, we have demonstrated that the Ce oxidation state (Ce{sup 3+}/Ce{sup 4+}) on the CeO{sub 2} surface can have a significant influence on the silicate adsorption.

  11. Electronic state of ruthenium deposited onto oxide supports: An XPS study taking into account the final state effects

    International Nuclear Information System (INIS)

    Larichev, Yurii V.; Moroz, Boris L.; Bukhtiyarov, Valerii I.

    2011-01-01

    The electronic state of ruthenium in the supported Ru/EO x (EO x = MgO, Al 2 O 3 or SiO 2 ) catalysts prepared by with the use of Ru(OH)Cl 3 or Ru(acac) 3 (acac = acetylacetonate) and reduced with H 2 at 723 K is characterized by X-ray photoelectron spectroscopy (XPS) in the Ru 3d, Cl 2p and O 1s regions. The influence of the final state effects (the differential charging and variation of the relaxation energy) on the binding energy (BE) of Ru 3d 5/2 core level measured for supported Ru nanoparticles is estimated by comparison of the Fermi levels and the modified Auger parameters determined for the Ru/EO x samples with the corresponding characteristics of the bulk Ru metal. It is found that the negative shift of the Ru 3d 5/2 peak which is observed in the spectrum of ruthenium deposited onto MgO (BE = 279.5-279.7 eV) with respect to that of Ru black (BE = 280.2 eV) or ruthenium supported on γ-Al 2 O 3 and SiO 2 (BE = 280.4 eV) is caused not by the transfer of electron density from basic sites of MgO, as considered earlier, but by the differential charging of the supported Ru particles compared with the support surface. Correction for the differential charging value reveals that the initial state energies of ruthenium in the Ru/EO x systems are almost identical (BE = 280.5 ± 0.1 eV) irrespectively of acid-base properties of the support, the mean size of supported Ru crystallites (within the range of 2-10 nm) and the surface Cl content. The results obtained suggest that the difference in ammonia synthesis activity between the Ru catalysts supported on MgO and on the acidic supports is accounted for by not different electronic state of ruthenium on the surface of these oxides but by some other reasons.

  12. Influence of oxidation state on the absorption of plutonium from the gastrointestinal tract

    International Nuclear Information System (INIS)

    Sullivan, M.F.; Ryan, J.L.; Gorham, L.S.; McFadden, K.M.

    1979-01-01

    Rats and guinea pigs treated intragastrically with either IV- or VI-valent 238 Pu showed no appreciable difference in absorption. Nitric acid solutions of 239 Pu (pH 2) were also administered to fasted and fed rats. When an oxidant (K 2 Cr 2 O 7 ) was present in the solution gavaged to fasted rats, absorption increased 34-fold. However, when 239 Pu VI was administered to fed rats in the absence of dichromate, there was no appreciable difference between the absorption of 239 Pu VI and 239 Pu IV

  13. Electroencephalogram, cognitive state, psychological disorders, clinical symptom, and oxidative stress in horticulture farmers exposed to organophosphate pesticides.

    Science.gov (United States)

    Bayrami, Mansour; Hashemi, Touraj; Malekirad, Ali Akbar; Ashayeri, Hassan; Faraji, Fardin; Abdollahi, Mohammad

    2012-02-01

    The aim of this paper was to study the toxicity of organophosphate (OP) pesticides in exposed farmers for electroencephalography, cognitive state, psychological disorders, clinical symptom, oxidative stress, acetylcholinesterase, and DNA damage. A comparative cross-sectional analysis was carried out in 40 horticulture farmers who were exposed to OPs in comparison to a control group containing 40 healthy subjects with the same age and sex and education level. Lipid peroxidation (LPO), superoxide dismutase (SOD), catalase, glutathione peroxidase, DNA damage, total antioxidant capacity (TAC), total thiol molecules, and acetylcholinesterase (AChE) activity were measured in the blood of subjects. Clinical examination and complete blood test were undertaken in order to record any abnormal sign or symptoms. Cognitive function, psychological symptoms, and psychological distress were examined and recorded. Comparing with controls, the farmers showed higher blood levels of SOD and LPO while their TAC decreased. Farmers showed clinical symptoms such as eczema, breathing muscle weakness, nausea, and saliva secretion. Regarding cognitive function, the orientation, registration, attention and calculation, recall, and language were not significantly different in farmers and controls. Among examinations for psychological distress, only labeled somatization was significantly higher in farmers. The present findings indicate that oxidative stress and inhibition of AChE can be seen in chronically OP-exposed people but incidence of neuropsychological disorders seems a complex multivariate phenomenon that might be seen in long-term high-dose exposure situations. Use of supplementary antioxidants would be useful in the treatment of farmers.

  14. Solid-state ionics: Studies of lithium-conducting sulfide glasses and a superconducting oxide compound

    International Nuclear Information System (INIS)

    Ahn, Byung Tae.

    1989-01-01

    The first part of this work studies lithium-conducting sulfide glasses for battery applications, while the second part studies the thermodynamic properties of a superconducting oxide compound by using an oxide electrolyte. Lithium conducting glasses based on the SiS 2 -Li 2 S system are possible solid electrolytes for high-energy-density lithium batteries. The foremost requirement for solid electrolytes is that they should have high ionic conductivities. Unfortunately, most crystalline lithium conductors have low ionic conductivities at room temperature. However, glass ionic conductors show higher ionic conductivities than do crystalline forms of the same material. In addition to higher ionic conductivities, glasses appear to have several advantages over crystalline materials. These advantages include isotropic conductivity, absence of grain boundary effects, ease of glass forming, and the potential for a wide range of stability to oxidizing and reducing conditions. Using pyrolitic graphite-coated quartz ampoules, new ternary compounds and glasses in the SiS 2 -Li 2 S system were prepared. Several techniques were used to characterize the materials: powder x-ray diffraction, differential thermal analysis, differential scanning calorimetry, and AC impedance spectroscopy. The measured lithium conductivity of the sulfide glasses was one of the highest among the known solid lithium conductors. Measuring the equilibrium open circuit voltages assisted in determining the electrochemical stabilities of the ternary compounds and glasses with respect to pure Li. A solid-state ionic technique called oxygen coulometric titration was used to measure the thermodynamic stability, the oxygen stoichiometry, and the effects of the oxygen stoichiometry, and the effects of the oxygen stoichiometry and the cooling rate on superconductivity of the YBa 2 Cu 3 O 7-x compound were investigated

  15. Effect of charge state and stoichiometry on the structure and reactivity of nickel oxide clusters with CO

    Science.gov (United States)

    Johnson, Grant E.; Reilly, Nelly M.; Castleman, A. W., Jr.

    2009-02-01

    The collision induced fragmentation and reactivity of cationic and anionic nickel oxide clusters with carbon monoxide were studied experimentally using guided-ion-beam mass spectrometry. Anionic clusters with a stoichiometry containing one more oxygen atom than nickel atom (NiO2-, Ni2O3-, Ni3O4- and Ni4O5-) were found to exhibit dominant products resulting from the transfer of a single oxygen atom to CO, suggesting the formation of CO2. Of these four species, Ni2O3- and Ni4O5- were observed to be the most reactive having oxygen transfer products accounting for approximately 5% and 10% of the total ion intensity at a maximum pressure of 15 mTorr of CO. Our findings, therefore, indicate that anionic nickel oxide clusters containing an even number of nickel atoms and an odd number of oxygen atoms are more reactive than those with an odd number of nickel atoms and an even number of oxygen atoms. The majority of cationic nickel oxides, in contrast to anionic species, reacted preferentially through the adsorption of CO onto the cluster accompanied by the loss of either molecular O2 or nickel oxide units. The adsorption of CO onto positively charged nickel oxides, therefore, is exothermic enough to break apart the gas-phase clusters. Collision induced dissociation experiments, employing inert xenon gas, were also conducted to gain insight into the structural properties of nickel oxide clusters. The fragmentation products were found to vary considerably with size and stoichiometry as well as ionic charge state. In general, cationic clusters favored the collisional loss of molecular O2 while anionic clusters fragmented through the loss of both atomic oxygen and nickel oxide units. Our results provide insight into the effect of ionic charge state on the structure of nickel oxide clusters. Furthermore, we establish how the size and stoichiometry of nickel oxide clusters influences their ability to oxidize CO, an important reaction for environmental pollution abatement.

  16. Present status of the microscopic study of low-lying collective states in spherical and transitional nuclei

    International Nuclear Information System (INIS)

    Marumori, Toshio; Takada, Kenjiro; Sakata, Fumihiko.

    1981-12-01

    The history and the present status of the microscopic study of the low-lying collective excited states in spherical and transitional nuclei are discussed by putting emphasis on explaining the rather modern microscopic investigations of the concept of collective subspace. Importance of the dynamical interplay between the pairing and the quadrupole correlations is emphasized as a crucial element to mediate coupling between the collective and non-collective subspace. (author)

  17. Remote Sensing the Thermosphere's State Using Emissions From Carbon Dioxide and Nitric Oxide

    Science.gov (United States)

    Weimer, D. R.; Mlynczak, M. G.; Doornbos, E.

    2017-12-01

    Measurements of emissions from nitric oxide and carbon dioxide in the thermosphere have strong correlations with properties that are very useful to the determination of thermospheric densities. We have compared emissions measured with the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite with neutral density measurements from the Challenging Mini-satellite Payload (CHAMP), the Gravity Recovery and Climate Experiment (GRACE), the Ocean Circulation Explorer (GOCE), and the three Swarm satellites, spanning a time period of over 15 years. It has been found that nitric oxide emissions match changes in the exospheric temperatures that have been derived from the densities through use of the Naval Reasearch Laboratory Mass Spectrometer, Incoherent Scatter Radar Extended Model (NRLMSISE-00) thermosphere model. Similarly, our results indicate that the carbon dioxide emissions have annual and semiannual oscillations that correlate with changes in the amount of oxygen in the thermosphere, also determined by use of the NRLMSISE-00 model. These annual and semi-annual variations are found to have irregular amplitudes and phases, which make them very difficult to accurately predict. Prediction of exospheric temperatures through the use of geomagnetic indices also tends to be inexact. Therefore, it would be possible and very useful to use measurements of the thermosphere's infrared emissions for real-time tracking of the thermosphere's state, so that more accurate calculations of the density may be obtained.

  18. Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh

    2006-07-31

    This report summarizes the work performed for Phase I (October 2001 - August 2006) under Cooperative Agreement DE-FC26-01NT41245 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled 'Solid State Energy Conversion Alliance (SECA) Solid Oxide Fuel Cell Program'. The program focuses on the development of a low-cost, high-performance 3-to-10-kW solid oxide fuel cell (SOFC) system suitable for a broad spectrum of power-generation applications. During Phase I of the program significant progress has been made in the area of SOFC technology. A high-efficiency low-cost system was designed and supporting technology developed such as fuel processing, controls, thermal management, and power electronics. Phase I culminated in the successful demonstration of a prototype system that achieved a peak efficiency of 41%, a high-volume cost of $724/kW, a peak power of 5.4 kW, and a degradation rate of 1.8% per 500 hours. . An improved prototype system was designed, assembled, and delivered to DOE/NETL at the end of the program. This prototype achieved an extraordinary peak efficiency of 49.6%.

  19. The effect of cerium valence states at cerium oxide nanoparticle surfaces on cell proliferation

    KAUST Repository

    Naganuma, Tamaki

    2014-05-01

    Understanding and controlling cell proliferation on biomaterial surfaces is critical for scaffold/artificial-niche design in tissue engineering. The mechanism by which underlying integrin ligates with functionalized biomaterials to induce cell proliferation is still not completely understood. In this study, poly-l-lactide (PL) scaffold surfaces were functionalized using layers of cerium oxide nanoparticles (CNPs), which have recently attracted attention for use in therapeutic application due to their catalytic ability of Ce4+ and Ce3+ sites. To isolate the influence of Ce valance states of CNPs on cell proliferation, human mesenchymal stem cells (hMSCs) and osteoblast-like cells (MG63) were cultured on the PL/CNP surfaces with dominant Ce4+ and Ce3+ regions. Despite cell type (hMSCs and MG63 cells), different surface features of Ce4+ and Ce3+ regions clearly promoted and inhibited cell spreading, migration and adhesion behavior, resulting in rapid and slow cell proliferation, respectively. Cell proliferation results of various modified CNPs with different surface charge and hydrophobicity/hydrophilicity, indicate that Ce valence states closely correlated with the specific cell morphologies and cell-material interactions that trigger cell proliferation. This finding suggests that the cell-material interactions, which influence cell proliferation, may be controlled by introduction of metal elements with different valence states onto the biomaterial surface. © 2014 Elsevier Ltd.

  20. Investigating the capability of ToF-SIMS to determine the oxidation state of Ce

    Science.gov (United States)

    Seed Ahmed, H. A. A.; Swart, H. C.; Kroon, R. E.

    2018-04-01

    The capability of time of flight secondary ion mass spectrometry (ToF-SIMS) to determine the oxidation state of Ce ions doped in a phosphor was investigated. Two samples of SiO2:Ce (4 mol%) with known Ce3+/Ce4+ relative concentrations were subjected to ToF-SIMS measurements. The spectra were very similar and no significant differences in the relative peak intensities were observed that would readily allow one to distinguish Ce3+ from Ce4+. Although ToF-SIMS was therefore not useful to distinguish the charge state of Ce ions doped in this phosphor material, the idea in principle was also tested on two other samples, namely CeF3 and CeF4 These contain Ce as part of the host (i.e. much higher concentration) and are fluorides, which is significant because ToF-SIMS has previously been reported to be able to distinguish Eu2+ from Eu3+ in Eu doped Sr5(PO4)3F phosphor. The spectrum of CeF4 contained a small peak related to Ce4+ which was not observed in the CeF3 spectrum, yet the peak related to the Ce3+ ions was found to be much more intense in the spectrum of CeF4 than CeF3, showing that the ToF-SIMS signals cannot be directly interpreted as retaining the charge state of the ions in the original material. Nevertheless, the significant differences in the Ce-related peaks in the ToF-SIMS spectra from CeF3 and CeF4 show that the charge state of Ce may be distinguished. This study shows that while in principle ToF-SIMS may be used to distinguish the charge state of Ce ions, this depends on the sample and it would not be easy to interpret the spectra without a standard or reference.

  1. Identification of the iron oxidation state and coordination geometry in iron oxide- and zeolite-based catalysts using pre-edge XAS analysis.

    Science.gov (United States)

    Boubnov, Alexey; Lichtenberg, Henning; Mangold, Stefan; Grunwaldt, Jan Dierk

    2015-03-01

    Analysis of the oxidation state and coordination geometry using pre-edge analysis is attractive for heterogeneous catalysis and materials science, especially for in situ and time-resolved studies or highly diluted systems. In the present study, focus is laid on iron-based catalysts. First a systematic investigation of the pre-edge region of the Fe K-edge using staurolite, FePO4, FeO and α-Fe2O3 as reference compounds for tetrahedral Fe(2+), tetrahedral Fe(3+), octahedral Fe(2+) and octahedral Fe(3+), respectively, is reported. In particular, high-resolution and conventional X-ray absorption spectra are compared, considering that in heterogeneous catalysis and material science a compromise between high-quality spectroscopic data acquisition and simultaneous analysis of functional properties is required. Results, which were obtained from reference spectra acquired with different resolution and quality, demonstrate that this analysis is also applicable to conventionally recorded pre-edge data. For this purpose, subtraction of the edge onset is preferentially carried out using an arctangent and a first-degree polynomial, independent of the resolution and quality of the data. For both standard and high-resolution data, multiplet analysis of pre-edge features has limitations due to weak transitions that cannot be identified. On the other hand, an arbitrary empirical peak fitting assists the analysis in that non-local transitions can be isolated. The analysis of the oxidation state and coordination geometry of the Fe sites using a variogram-based method is shown to be effective for standard-resolution data and leads to the same results as for high-resolution spectra. This method, validated by analysing spectra of reference compounds and their well defined mixtures, is finally applied to track structural changes in a 1% Fe/Al2O3 and a 0.5% Fe/BEA zeolite catalyst during reduction in 5% H2/He. The results, hardly accessible by other techniques, show that Fe(3+) is

  2. Coherent diffractive imaging of solid state reactions in zinc oxide crystals

    Science.gov (United States)

    Leake, Steven J.; Harder, Ross; Robinson, Ian K.

    2011-11-01

    We investigated the doping of zinc oxide (ZnO) microcrystals with iron and nickel via in situ coherent x-ray diffractive imaging (CXDI) in vacuum. Evaporated thin metal films were deposited onto the ZnO microcrystals. A single crystal was selected and tracked through annealing cycles. A solid state reaction was observed in both iron and nickel experiments using CXDI. A combination of the shrink wrap and guided hybrid-input-output phasing methods were applied to retrieve the electron density. The resolution was 33 nm (half order) determined via the phase retrieval transfer function. The resulting images are nevertheless sensitive to sub-angstrom displacements. The exterior of the microcrystal was found to degrade dramatically. The annealing of ZnO microcrystals coated with metal thin films proved an unsuitable doping method. In addition the observed defect structure of one crystal was attributed to the presence of an array of defects and was found to change upon annealing.

  3. State-of-the-art technologies of gallium oxide power devices

    Science.gov (United States)

    Higashiwaki, Masataka; Kuramata, Akito; Murakami, Hisashi; Kumagai, Yoshinao

    2017-08-01

    Gallium oxide (Ga2 O3 ) has gained increased attention for power devices due to its superior material properties and the availability of economical device-quality native substrates. This review illustrates recent advances in Ga2 O3 device technologies, beginning with an overview of the social circumstances that motivate the development of new-generation switching devices. Following an introduction to the material properties of Ga2 O3 from the viewpoint of power electronics, growth technologies of Ga2 O3 bulk single crystals and epitaxial thin films are discussed. The fabrication and performance of state-of-the-art Ga2 O3 transistors and diodes are then described. We conclude by identifying the directions and challenges of Ga2 O3 power device development in the near future.

  4. Coordination and Oxidation States of Iron Incorporated in Mesoporous MCM41

    International Nuclear Information System (INIS)

    Lazar, K.; Pal-Borbely, G.; Szegedi, A.; Beyer, H. K.

    2002-01-01

    Mesoporous Fe-MCM41 samples (Si/Fe=25) were synthesized and characterized under evacuation and reducing/oxidizing treatments by in situ FTIR and Moessbauer spectroscopies. Both Fe(II) and Fe(III) located in low coordination states in top layers of pore walls exhibit Lewis acidity and may participate in Fe(III) ↔ Fe(II) processes at low temperatures (570 K). Furthermore, Fe(III) ↔ Fe(II) cycles can be achieved and repeated with participation of the full amount of iron at higher temperatures (670 K). The accompanying formation of oxygen vacancies and restoration of the structure in the reverse process does not result in extended damages; the MCM41 structure retains its stability under the conditions applied.

  5. Iron oxides as pedoenvironmental indicators: state of the art, answers and questions (Philippe Duchaufour Medal Lecture)

    Science.gov (United States)

    Torrent, J.

    2012-04-01

    environmental information from magnetic data is hampered by a still incomplete understanding of (i) the pathways through which pedogenic ferrimagnets are formed, and the chemical and biological factors that affect them; and (ii) the genetic relationships between ferrimagnets and other iron oxides. Competing hypotheses on these issues will be presented and their usefulness for pedoenvironmental interpretations discussed.

  6. Priorities in the State Policy of Unshadowing the National Economy of Ukraine at the Present Stage of Development

    Directory of Open Access Journals (Sweden)

    Avhustyn Ruslan R.

    2016-11-01

    Full Text Available The aim of the article is to justify the priorities of the state policy of unshadowing the national economy in the system of basic characteristics of the state economic security at the present stage of development. There made a conclusion about the perspectiveness of aligning the policy of economy unshadowing with forming a viable system of economic security of Ukraine, which allows to achieve a synergistic effect oriented both towards counteraction to the shadowing of economic relations and comprehensive enhancement of key parameters of the state economic security, including through the economy unshadowing. Consequently, the strategic priorities are defined in the following areas: (1 self-sufficiency of economic development and provision of the policy of economy unshadowing (forming the environment of perception of the shadow economy, resource support and an information and analytical system of economy unshadowing; introducing effective foreign technologies; increasing the efficiency in the regulatory sphere; (2 stability of the economic system and high capacity of the policy of economy unshadowing (legalization of the national economy in the branch-sectoral as well as spatial and structural aspects by structural elements of the state security, in the financial system and the internal market; (3 ability of the economy to develop and realize the potential of the policy of economy unshadowing (building the infrastructure; introducing «fuses» of control, human and intellectual, investment and innovation support of the economy unshadowing

  7. Ultrathin reduced graphene oxide films as transparent top-contacts for light switchable solid-state molecular junctions

    DEFF Research Database (Denmark)

    Li, Tao; Jevric, Martyn; Hauptmann, Jonas Rahlf

    2013-01-01

    A new type of solid-state molecular junction is introduced, which employs reduced graphene oxide as a transparent top contact that permits a self-assembled molecular monolayer to be photoswitched in situ, while simultaneously enabling charge-transport measurements across the molecules. The electr......A new type of solid-state molecular junction is introduced, which employs reduced graphene oxide as a transparent top contact that permits a self-assembled molecular monolayer to be photoswitched in situ, while simultaneously enabling charge-transport measurements across the molecules...

  8. Head injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and football.

    Science.gov (United States)

    Delaney, J Scott

    2004-03-01

    To examine the number and rates of head injuries occurring in the community as a whole for the team sports of ice hockey, soccer, and football by analyzing data from patients presenting to US emergency departments (EDs) from 1990 to 1999. Retrospective analysis. Data compiled for the US Consumer Product Safety Commission using the National Electronic Injury Surveillance System were used to generate estimates for the total number of head injuries, concussions, internal head injuries, and skull fractures occurring on a national level from the years 1990 to 1999. These data were combined with yearly participation figures to generate rates of injuries presenting to the ED for each sport. There were an estimated 17,008 head injuries from ice hockey, 86,697 from soccer, and 204,802 from football that presented to US EDs from 1990 to 1999. The total number of concussions presenting to EDs in the United States over the same period was estimated to be 4820 from ice hockey, 21,715 from soccer, and 68,861 from football. While the rates of head injuries, concussions, and combined concussions/internal head injuries/skull fractures presenting to EDs per 10,000 players were not always statistically similar for all 3 sports in each year data were available, they were usually comparable. While the total numbers of head injuries, concussions, and combined concussions/skull fractures/internal head injuries presenting to EDs in the United States are different for ice hockey, soccer, and football for the years studied, the yearly rates for these injuries are comparable among all 3 sports.

  9. Reactivity of biogenic manganese oxide for metal sequestration and photochemistry: Computational solid state physics study

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, K.D.; Sposito, G.

    2010-02-01

    Many microbes, including both bacteria and fungi, produce manganese (Mn) oxides by oxidizing soluble Mn(II) to form insoluble Mn(IV) oxide minerals, a kinetically much faster process than abiotic oxidation. These biogenic Mn oxides drive the Mn cycle, coupling it with diverse biogeochemical cycles and determining the bioavailability of environmental contaminants, mainly through strong adsorption and redox reactions. This mini review introduces recent findings based on quantum mechanical density functional theory that reveal the detailed mechanisms of toxic metal adsorption at Mn oxide surfaces and the remarkable role of Mn vacancies in the photochemistry of these minerals.

  10. What is the evidence that poster presentations are effective in promoting knowledge transfer? A state of the art review.

    Science.gov (United States)

    Ilic, Dragan; Rowe, Nicholas

    2013-03-01

    Poster presentations are a common form of presenting health information at conferences and in the community. Anecdotal evidence within the discipline indicates that health information framed in a poster presentation may be an effective method of knowledge transfer. A state of the art review of the literature was performed to determine the effectiveness of poster presentations on knowledge transfer. Electronic searches of various electronic databases were performed for studies published until 2012. Studies were eligible for inclusion if they provided empirical data on the effectiveness of poster presentations on changes in participant knowledge, attitude or behaviour. A total of 51 studies were identified through the database searches, of which 15 met the inclusion criteria. No study evaluated the effectiveness of posters in comparison with other educational interventions. Most studies utilised a before/after methodology, with the common conclusion that posters elicit greatest effectiveness in knowledge transfer when integrated with other educational modalities. The poster presentation is a commonly used format for communicating information within the academic and public health fields. Evidence from well-designed studies comparing posters to other educational modalities is required to establish an evidence base on the effectiveness of utilising posters in achieving knowledge transfer. © 2013 The authors. Health Information and Libraries Journal © 2013 Health Libraries Group.

  11. Solid state oxidation of phenols to quinones with sodium perborate on wet montmorillonite K10

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Mohammed M.; Eftekhari-Sis, Bagher; Khalili, Behzad; Karimi-Jaberi, Zahed [Sharif University of Technology, Tehran (Iran, Islamic Republic of). Dept. of Chemistry]. E-mail: mhashemi@sharif.edu

    2005-09-15

    Phenols were oxidized to quinones using sodium perborate (SPB) on wet montmorillonite as oxidant. The reaction was carried out at ambient temperature on the solid phase under solvent free conditions. (author)

  12. Solid state oxidation of phenols to quinones with sodium perborate on wet montmorillonite K10

    International Nuclear Information System (INIS)

    Hashemi, Mohammed M.; Eftekhari-Sis, Bagher; Khalili, Behzad; Karimi-Jaberi, Zahed

    2005-01-01

    Phenols were oxidized to quinones using sodium perborate (SPB) on wet montmorillonite as oxidant. The reaction was carried out at ambient temperature on the solid phase under solvent free conditions. (author)

  13. Four Generations of Maintenance Resource Management Programs in the United States: An Analysis of the Past, Present, and Future

    Science.gov (United States)

    Taylor, James C.; Patankar, Manoj S.

    2001-01-01

    This paper analyzes four generations of Maintenance Resource Management (MRM) programs implemented by aviation maintenance organizations in the United States. Data collected from over ten years of survey research and field observations are used for this analysis; they are presented in a case-study format. The first three generations of MRM programs were episodic efforts to increase safety through teamwork, focus group discussions, and awareness courses, respectively. Now, the fourth generation programs, characterized by a commitment to long-term communication and behavioral changes in maintenance, are set to build on those earlier generations, toward a culture of mutual trust between mechanics, their managers, and regulators.

  14. Transfer of knowledge to the next generation for safety assurance-present state and subjects of organizational approach

    International Nuclear Information System (INIS)

    Ueno, Akira

    2005-01-01

    Recently, many organizational accidents have occurred in the electric power, railroad, airline, chemical, food and medical industries due to a lack of knowledge and technology indispensable for effective management. This raises the question of how important transfer of technology and knowledge management is in organizations. This paper clarified present state and related subjects of this problem in terms of human and organizational factors and introduced some advanced cases for the solution so as to find a way to practice the situation-dependent combined approach of existing organizational training and latest knowledge science. (T. Tanaka)

  15. Present state and problems of radiological protection monitoring for high energy electron accelerator facilities in SPring-8

    International Nuclear Information System (INIS)

    Miyamoto, Yukihiro; Harada, Yasunori; Ueda, Hisao

    1998-09-01

    The present state and problems of the radiological protection monitoring for the high-energy electron accelerator are summarized. In the radiological protection monitoring for SPring-8, a third generation synchrotron radiation facility, there are many problems specific to the high-energy electron accelerator. This report describes the monitoring technique of pulsed radiation, high-energy radiation and low-energy radiation, and their problems. The management of induced radioactivity and the effects of electro-magnetic noise to monitoring instruments are also discussed. (author)

  16. Oxidation of an aluminium-magnesium alloy in liquid state. Methodology of determination of mechanisms from not necessarily repeatable experiments

    International Nuclear Information System (INIS)

    Surla, Karine

    1998-01-01

    This research thesis reports the study of the oxidation of an aluminium-5 pc magnesium alloy in its liquid state in an oxygen environment, using thermogravimetric analysis and that of magnesium in its solid state. In a first part, the author reports a thermodynamic and bibliographical study on magnesium transformation in its solid state (Mg/O 2 and Mg/H 2 O systems, transformation with dry and humid synthetic air, oxidation inhibitors) and on Al-Mg alloy transformation in presence of oxygen (thermodynamic properties of aluminium-rich Al-Mg alloys, Al-Mg/O 2 /N 2 and Al-Mg/O 2 /N 2 /H 2 O systems). The next parts address the selection of reaction systems for the different cases (oxidation of solid magnesium in oxygen, oxidation of the Al-Mg alloy in oxygen), the modelling of the formation of magnesia from solid magnesium and from the Al-Mg alloy, and the modelling of the liquid Al-Mg A5182 alloy oxidation in oxygen [fr

  17. Cellulose nanofibril/reduced graphene oxide/carbon nanotube hybrid aerogels for highly flexible and all-solid-state supercapacitors.

    Science.gov (United States)

    Zheng, Qifeng; Cai, Zhiyong; Ma, Zhenqiang; Gong, Shaoqin

    2015-02-11

    A novel type of highly flexible and all-solid-state supercapacitor that uses cellulose nanofibril (CNF)/reduced graphene oxide (RGO)/carbon nanotube (CNT) hybrid aerogels as electrodes and H2SO4/poly(vinyl alcohol) (PVA) gel as the electrolyte was developed and is reported here. These flexible solid-state supercapacitors were fabricated without any binders, current collectors, or electroactive additives. Because of the porous structure of the CNF/RGO/CNT aerogel electrodes and the excellent electrolyte absorption properties of the CNFs present in the aerogel electrodes, the resulting flexible supercapacitors exhibited a high specific capacitance (i.e., 252 F g(-1) at a discharge current density of 0.5 A g(-1)) and a remarkable cycle stability (i.e., more than 99.5% of the capacitance was retained after 1000 charge-discharge cycles at a current density of 1 A g(-1)). Furthermore, the supercapacitors also showed extremely high areal capacitance, areal power density, and energy density (i.e., 216 mF cm(-2), 9.5 mW cm(-2), and 28.4 μWh cm(-2), respectively). In light of its excellent electrical performance, low cost, ease of large-scale manufacturing, and environmental friendliness, the CNF/RGO/CNT aerogel electrodes may have a promising application in the development of flexible energy-storage devices.

  18. Hydrophobic matrix-free graphene-oxide composites with isotropic and nematic states

    Science.gov (United States)

    Wåhlander, Martin; Nilsson, Fritjof; Carlmark, Anna; Gedde, Ulf W.; Edmondson, Steve; Malmström, Eva

    2016-08-01

    We demonstrate a novel route to synthesise hydrophobic matrix-free composites of polymer-grafted graphene oxide (GO) showing isotropic or nematic alignment and shape-memory effects. For the first time, a cationic macroinitiator (MI) has been immobilised on anionic GO and subsequently grafted with hydrophobic polymer grafts. Dense grafts of PBA, PBMA and PMMA with a wide range of average graft lengths (MW: 1-440 kDa) were polymerised by surface-initiated controlled radical precipitation polymerisation from the statistical MI. The surface modification is designed similarly to bimodal graft systems, where the cationic MI generates nanoparticle repulsion, similar to dense short grafts, while the long grafts offer miscibility in non-polar environments and cohesion. The state-of-the-art dispersions of grafted GO were in the isotropic state. Transparent and translucent matrix-free GO-composites could be melt-processed directly using only grafted GO. After processing, birefringence due to nematic alignment of grafted GO was observed as a single giant Maltese cross, 3.4 cm across. Permeability models for composites containing aligned 2D-fillers were developed, which were compared with the experimental oxygen permeability data and found to be consistent with isotropic or nematic states. The storage modulus of the matrix-free GO-composites increased with GO content (50% increase at 0.67 wt%), while the significant increases in the thermal stability (up to 130 °C) and the glass transition temperature (up to 17 °C) were dependent on graft length. The tuneable matrix-free GO-composites with rapid thermo-responsive shape-memory effects are promising candidates for a vast range of applications, especially selective membranes and sensors.We demonstrate a novel route to synthesise hydrophobic matrix-free composites of polymer-grafted graphene oxide (GO) showing isotropic or nematic alignment and shape-memory effects. For the first time, a cationic macroinitiator (MI) has been

  19. The Effect of Precursor Ligands and Oxidation State in the Synthesis of Bimetallic Nano-Alloys

    KAUST Repository

    LaGrow, Alec P.

    2015-05-12

    The characteristics of bimetallic nanomaterials are dictated by their size, shape and elemental distribution. Solution synthesis is widely utilized to form nanomaterials, such as nanoparticles, with controlled size and shape. However, the effects of variables on the characteristics of bimetallic nanomaterials are not completely understood. In this study, we used a continuous-flow synthetic strategy to explore the effects of the ligands and the oxidation state of a metal precursor in a shape-controlled synthesis on the final shape of the nanomaterials and the elemental distribution within the alloy. We demonstrate that this strategy can tune the size of monodisperse PtM (M=Ni or Cu) alloy nanocrystals ranging from 3 to 16 nm with an octahedral shape using acetylacetonate or halide precursors of Pt(II), Pt(IV) and Ni or Cu (II). The nanoparticles formed from halide precursors showed an enrichment of platinum on their surfaces, and the bromides could oxidatively etch the nanoparticles during synthesis with the O2/Br- pair. The two nanocrystal precursors can be uti-lized independently and can control the size with a trend of Pt(acac)2

  20. Present state of studies on FFAG accelerator for radiotherapy of cancer in National Institute of Radiological Sciences

    International Nuclear Information System (INIS)

    Misu, Toshiyuki

    2003-01-01

    From 2001, developmental contract studies with Ministry of Education, Culture, Sports, Science and Technology for a compact accelerator for heavy ion radiotherapy of cancer started in National Institute of Radiological Sciences (NIRS) with use of fixed field alternating gradient (FFAG) accelerator, which had been developed in High Energy Accelerator Research Organization (KEK). This paper describes the present state of those studies. Described are FFAG accelerator design for repeated acceleration for 200 Hz or more toward the carbon ion at 400 MeV/u with the range of 25 cm in water, FFAG optical systems for these purposes by linear analyses, and the present situation of the design. Technological problems yielded and future study plan are also commented. (N.I.)

  1. Electrochemical and spectroscopic studies of some less stable oxidation states of selected lanthanide and actinide elements

    International Nuclear Information System (INIS)

    Hobart, D.E.

    1981-06-01

    Simultaneous observation of electrochemical and spectroscopic properties (spectroelectrochemistry) at optically transparent electrodes (OTE's) was used to study some less stable oxidation states of selected lanthanide and actinide elements. Cyclic voltammetry at microelectrodes was used in conjunction with spectroelectrochemistry for the study of redox couples. Additional analytical techniques were used. The formal reduction potential (E 0 ') values of the M(III)/M(II) redox couples in 1 M KCl at pH 6 were -0.34 +- 0.01 V for Eu, -1.18 +- 0.01 V for Yb, and -1.50 +- 0.01 V for Sm. Spectropotentiostatic determination of E 0 ' for the Eu(III)/Eu(II) redox couple yielded a value of -0.391 +- 0.005 V. Spectropotentiostatic measurement of the Ce(IV)/Ce(III) redox couple in concentrated carbonate solution gave E 0 ' equal to 0.051 +- 0.005 V, which is about 1.7 V less positive than the E 0 ' value in noncomplexing solution. This same difference in potential was observed for the E 0 ' values of the Pr(IV)/Pr(III) and Tb(IV)/Tb(III) redox couples in carbonate solution, and thus Pr(IV) and Tb(IV) were stabilized in this medium. The U(VI)/U(V)/U(IV) and U(IV)/U(III) redox couples were studied in 1 M KCl at OTE's. Spectropotentiostatic measurement of the Np(VI)/Np(V) redox couple in 1 M HClO 4 gave an E 0 ' value of 1.140 +- 0.005 V. An E 0 ' value of 0.46 +- 0.01 V for the Np(VII)/Np(VI) couple was found by voltammetry. Oxidation of Am(III) was studied in concentrated carbonate solution, and a reversible cyclic voltammogram for the Am(IV)/Am(III) couple yielded E 0 ' = 0.92 +- 0.01 V in this medium; this value was used to estimate the standard reduction potential (E 0 ) of the couple as 2.62 +- 0.01 V. Attempts to oxidize Cm(III) in concentrated carbonate solution were not successful which suggests that the predicted E 0 value for the Cm(IV)/Cm(III) redox couple may be in error

  2. Application of high-pressure techniques: stabilization and oxidation-state control of novel superconductive and related multi-layered copper oxides

    International Nuclear Information System (INIS)

    Yamauchi, H.; Karppinen, M.

    2000-01-01

    Copper oxide superconductors possess multi-layered structures with a layer sequence of -CuO 2 -(Q-CuO 2 ) n-1 -AO-(MO 1±δ ) m -AO- or -CuO 2 -B-(O 2 -B) s-1 -CuO 2 -AO-(MO 1±δ ) m -AO- along the elongated c axis. Based on this layer sequence, the known copper oxide structures are categorized as members of the homologous series, M m A r Q n-1 Cu n O m+r+2 +n ±δ (M-mr(n-1)n ; category A) or M m A 2k B s Cu 1+k O m +4k +2s±δ (M-m(2k)s (1+k ); category B). Stabilization of such structures especially in the case of high values of the n /s parameter, i.e. the higher members of the homologous series, has been demonstrated to be apparently promoted under high pressures and/or strongly oxidizing conditions. Consequently, techniques for applying both high oxygen gas pressures (10-2000 atm) and ultra-high solid-medium pressures (2-8 GPa) have been advantageously utilized in synthesizing various superconductive copper oxide phases. Especially the ultra-high solid-medium pressure synthesis carried out in the so-called cubic-anvil/belt-type apparatus has proven to be extremely successful in synthesizing novel superconductive phases. In order to achieve high partial pressures of oxygen in the solid-medium environment, 'external' oxygen-generating oxides such as KClO 4 , KClO 3 and Ag 2 O 2 are commonly added to the precursor mixtures. It is emphasized that in some cases it is possible to utilize 'internal' oxidizing agents alone, i.e. highly oxidized precursors such as BaCuO 2+δ and Ba 2 Cu 3 O 5+δ containing metal constituents common with the desired copper oxide phase only. In the present paper, the potential and applications of high-pressure techniques in synthesizing multi-layered copper oxides and related structures are reviewed and discussed with emphasis on the important 'historical' discoveries of novel phases and the present status of controlled production of high-quality samples of such phases. (author)

  3. The effect on phase separation of the oxidation state of molybdenum in a Na2O-B2O3-SiO2 glass

    International Nuclear Information System (INIS)

    Kawamoto, Y.; Clemens, K.; Tomozawa, M.; Warden, J.T.

    1981-01-01

    The effect of oxidation state on phase separation was studied for 13Na 2 O, 49B 2 O 3 , 38SiO 2 (mol%) glasses containing 1 mol% Mo oxide. The glasses were melted under various conditions to vary the oxidation states of Mo ions. The oxidation states of Mo ions were determined by chemical analysis and ESR. The crystallisation tendency, the immiscibility temperature, and the phase separation morphology of the glasses were examined by DTA, x-ray diffraction, opalescence method, and replica electron microscopy. Glasses containing Mo 4+ ions have a great tendency to precipitate MoO 2 crystals. The immiscibility temperature of glass goes through a minimum when the oxidation states of Mo ions are changed. It was suggested that there is an optimum oxidation state to prevent crystallisation and to suppress the phase separation tendency of this system. (author)

  4. Operando XAS Study of the Surface Oxidation State on a Monolayer IrOx on RuOx and Ru Oxide Based Nanoparticles for Oxygen Evolution in Acidic Media

    DEFF Research Database (Denmark)

    Pedersen, Anders Filsøe; Escribano, Maria Escudero; Sebok, Bela

    2018-01-01

    that the average Ir oxidation state change is strongly affected by the coverage of atomic O. The observed shifts in oxidation state suggest that the surface has a high coverage of O at potentials just below the potential where oxygen evolution is exergonic in free energy. This observation is consistent...

  5. Effect of high doses of L-ascorbic acid on the antioxidative/oxidative state in the rats

    DEFF Research Database (Denmark)

    Niemiec, T.; Sawosz, E.; Chwalibog, André

    2005-01-01

    The objective of this study was to determine the effects of mega-doses of vitamin C (0.3, 0.6 and 0.9% of diet) as a dietary supplement for rats on selected indices of the antioxidative/oxidative state in 40 growing Wistar rats (4x10). It was found that L-ascorbic acid and Total Antioxidative State...... (TAS) in plasma did not increase with increasing vitamin C supply. The results indicate that high doses of L-ascorbic acid (0.3 and 0.9 but not 0.6%) increased the concentration of this antioxidant in plasma. Supplementation of vitamin C above 0.3% to the diets had pro-oxidative effects on lipid...... structures, while application of 0.9% promoted oxidative degradation of rat livers....

  6. Structural and spectroscopic characterisations of the surface oxide scales and inclusions present on edge-burst hot-rolled steel coils

    International Nuclear Information System (INIS)

    Chowdhury, Anirban; Iyyappan, Ramasamy; Majumdar, Dipanwita; Singha, Achintya

    2014-01-01

    Detailed structural and spectroscopic characterisations have been carried out on the inclusions and the surface oxides present on edge-burst hot-rolled steel coils. Surface scales were characterised through X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. Evidence of different types of regular and non-stoichiometric Fe-oxides was found on the cracked surface of the steel wire. Along with the surface scales inclusions with calcium aluminate and spinel was characterized using Raman spectroscopy. The usefulness of Raman spectroscopy has been explored in detail for the characterisation of these inclusions; especially when XRD information ceases to be a limiting tool. The samples collected from the clogged nozzle area were found to be of grossite (CaO·2Al 2 O 3 ) phase and this was also observed in the inclusions in the finished coils. It was found that this particular calcium aluminate phase has a detrimental effect on casting and final finished steel products. - Highlights: • First investigation and surface study report on edge-bursting issue of steel coils. • Detailed characterisations of the inclusions and surface oxide scales in steel. • Influence of a particular type of calcium aluminate phase on process chemistry

  7. Short review of high-pressure crystal growth and magnetic and electrical properties of solid-state osmium oxides

    Energy Technology Data Exchange (ETDEWEB)

    Yamaura, Kazunari, E-mail: YAMAURA.Kazunari@nims.go.jp [Superconducting Properties Unit, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Graduate School of Chemical Sciences and Engineering, Hokkaido University, North 10 West 8, Kita-ku, Sapporo, Hokkaido 060-0810 (Japan)

    2016-04-15

    High-pressure crystal growth and synthesis of selected solid-state osmium oxides, many of which are perovskite-related types, are briefly reviewed, and their magnetic and electrical properties are introduced. Crystals of the osmium oxides, including NaOsO{sub 3}, LiOsO{sub 3}, and Na{sub 2}OsO{sub 4}, were successfully grown under high-pressure and high-temperature conditions at 6 GPa in the presence of an appropriate amount of flux in a belt-type apparatus. The unexpected discovery of a magnetic metal–insulator transition in NaOsO{sub 3}, a ferroelectric-like transition in LiOsO{sub 3}, and high-temperature ferrimagnetism driven by a local structural distortion in Ca{sub 2}FeOsO{sub 6} may represent unique features of the osmium oxides. The high-pressure and high-temperature synthesis and crystal growth has played a central role in the development of solid-state osmium oxides and the elucidation of their magnetic and electronic properties toward possible use in multifunctional devices. - Graphical Abstract: Flux-grown crystals of NaOsO{sub 3} under high-pressure and high-temperature conditions in a belt-type apparatus. The crystal shows a magnetically driven metal–insulator transition at a temperature of 410 K. - Highlights: • Short review of high-pressure crystal growth of solid-state osmium oxides. • Wide variety of magnetic properties of solid-state osmium oxides. • Perovskite and related dense structures stabilized at 3–17 GPa.

  8. Pu oxidation state distributions in suspensions of the Mont Terri Opalinus Clay isolate Sporomusa sp. MT-2.99

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Henry [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group; Bok, Frank [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    The time-dependent {sup 242}Pu oxidation state distribution in the presence of Sporomusa sp. cells as a function of pH with or without Na-pyruvate was analyzed. In all cases, the presence of bacterial cells enhanced removal of Pu from solution and accelerated Pu interaction reactions, e.g. biosorption and bioreduction.

  9. Pu oxidation state distributions in suspensions of the Mont Terri Opalinus Clay isolate Sporomusa sp. MT-2.99

    International Nuclear Information System (INIS)

    Moll, Henry; Cherkouk, Andrea; Bok, Frank

    2017-01-01

    The time-dependent "2"4"2Pu oxidation state distribution in the presence of Sporomusa sp. cells as a function of pH with or without Na-pyruvate was analyzed. In all cases, the presence of bacterial cells enhanced removal of Pu from solution and accelerated Pu interaction reactions, e.g. biosorption and bioreduction.

  10. Stress Survival Islet 2, Predominantly Present in Listeria monocytogenes Strains of Sequence Type 121, Is Involved in the Alkaline and Oxidative Stress Responses.

    Science.gov (United States)

    Harter, Eva; Wagner, Eva Maria; Zaiser, Andreas; Halecker, Sabrina; Wagner, Martin; Rychli, Kathrin

    2017-08-15

    The foodborne pathogen Listeria monocytogenes is able to survive a variety of stress conditions leading to the colonization of different niches like the food processing environment. This study focuses on the hypervariable genetic hot spot lmo0443 to lmo0449 haboring three inserts: the stress survival islet 1 (SSI-1), the single-gene insert LMOf2365_0481 , and two homologous genes of the nonpathogenic species Listeria innocua : lin0464 , coding for a putative transcriptional regulator, and lin0465 , encoding an intracellular PfpI protease. Our prevalence study revealed a different distribution of the inserts between human and food-associated isolates. The lin0464-lin0465 insert was predominantly found in food-associated strains of sequence type 121 (ST121). Functional characterization of this insert showed that the putative PfpI protease Lin0465 is involved in alkaline and oxidative stress responses but not in acidic, gastric, heat, cold, osmotic, and antibiotic stresses. In parallel, deletion of lin0464 decreased survival under alkaline and oxidative stresses. The expression of both genes increased significantly under oxidative stress conditions independently of the alternative sigma factor σ B Furthermore, we showed that the expression of the protease gene lin0465 is regulated by the transcription factor lin0464 under stress conditions, suggesting that lin0464 and lin0465 form a functional unit. In conclusion, we identified a novel stress survival islet 2 (SSI-2), predominantly present in L. monocytogenes ST121 strains, beneficial for survival under alkaline and oxidative stresses, potentially supporting adaptation and persistence of L. monocytogenes in food processing environments. IMPORTANCE Listeria monocytogenes strains of ST121 are known to persist for months and even years in food processing environments, thereby increasing the risk of food contamination and listeriosis. However, the molecular mechanism underlying this remarkable niche-specific adaptation

  11. Arsenic K-edge X-ray absorption near-edge spectroscopy to determine oxidation states of arsenic of a coastal aquifer–aquitard system

    International Nuclear Information System (INIS)

    Wang, Ya; Jiao, Jiu Jimmy; Zhu, Sanyuan; Li, Yiliang

    2013-01-01

    Determination of oxidation states of solid-phase arsenic in bulk sediments is a valuable step in the evaluation of its bioavailability and environmental fate in deposits, but is difficult when the sediments have low arsenic contents and heterogeneous distribution of arsenic species. As K-edge X-ray absorption near-edge spectroscopy (XANES) was used to determine quantitatively the oxidation states of arsenic in sediments collected from different depths of boreholes in the Pearl River Delta, China, where the highest aquatic arsenic concentration is 161.4 μg/L, but the highest solid arsenic content only 39.6 mg/kg. The results demonstrated that XANES is efficient in determining arsenic oxidation states of the sediments with low arsenic contents and multiple arsenic species. The study on the high-resolution vertical variations of arsenic oxidation states also indicated that these states are influenced strongly by groundwater activities. With the help of geochemical data, solid arsenic speciation, toxicity and availability were further discussed. -- Highlights: •XANES is efficient in determining arsenic oxidation states of the bulk sediments. •Distribution of arsenic oxidation states is consistent with geochemical conditions. •Arsenic oxidation states are influenced strongly by groundwater activities. -- As K-edge X-ray absorption near-edge spectroscopy is efficient in determining arsenic oxidation states of the bulk sediments with low arsenic contents and heterogeneous distribution of arsenic species

  12. Enzyme phylogenies as markers for the oxidation state of the environment: the case of respiratory arsenate reductase and related enzymes.

    Science.gov (United States)

    Duval, Simon; Ducluzeau, Anne-Lise; Nitschke, Wolfgang; Schoepp-Cothenet, Barbara

    2008-07-16

    Phylogenies of certain bioenergetic enzymes have proved to be useful tools for deducing evolutionary ancestry of bioenergetic pathways and their relationship to geochemical parameters of the environment. Our previous phylogenetic analysis of arsenite oxidase, the molybdopterin enzyme responsible for the biological oxidation of arsenite to arsenate, indicated its probable emergence prior to the Archaea/Bacteria split more than 3 billion years ago, in line with the geochemical fact that arsenite was present in biological habitats on the early Earth. Respiratory arsenate reductase (Arr), another molybdopterin enzyme involved in microbial arsenic metabolism, serves as terminal oxidase, and is thus situated at the opposite end of bioenergetic electron transfer chains as compared to arsenite oxidase. The evolutionary history of the Arr-enzyme has not been studied in detail so far. We performed a genomic search of genes related to arrA coding for the molybdopterin subunit. The multiple alignment of the retrieved sequences served to reconstruct a neighbor-joining phylogeny of Arr and closely related enzymes. Our analysis confirmed the previously proposed proximity of Arr to the cluster of polysulfide/thiosulfate reductases but also unravels a hitherto unrecognized clade even more closely related to Arr. The obtained phylogeny strongly suggests that Arr originated after the Bacteria/Archaea divergence in the domain Bacteria, and was subsequently laterally distributed within this domain. It further more indicates that, as a result of accumulation of arsenate in the environment, an enzyme related to polysulfide reductase and not to arsenite oxidase has evolved into Arr. These findings are paleogeochemically rationalized by the fact that the accumulation of arsenate over arsenite required the increase in oxidation state of the environment brought about by oxygenic photosynthesis.

  13. Visualizing chemical states and defects induced magnetism of graphene oxide by spatially-resolved-X-ray microscopy and spectroscopy.

    Science.gov (United States)

    Wang, Y F; Singh, Shashi B; Limaye, Mukta V; Shao, Y C; Hsieh, S H; Chen, L Y; Hsueh, H C; Wang, H T; Chiou, J W; Yeh, Y C; Chen, C W; Chen, C H; Ray, Sekhar C; Wang, J; Pong, W F; Takagi, Y; Ohigashi, T; Yokoyama, T; Kosugi, N

    2015-10-20

    This investigation studies the various magnetic behaviors of graphene oxide (GO) and reduced graphene oxides (rGOs) and elucidates the relationship between the chemical states that involve defects therein and their magnetic behaviors in GO sheets. Magnetic hysteresis loop reveals that the GO is ferromagnetic whereas photo-thermal moderately reduced graphene oxide (M-rGO) and heavily reduced graphene oxide (H-rGO) gradually become paramagnetic behavior at room temperature. Scanning transmission X-ray microscopy and corresponding X-ray absorption near-edge structure spectroscopy were utilized to investigate thoroughly the variation of the C 2p(π*) states that are bound with oxygen-containing and hydroxyl groups, as well as the C 2p(σ*)-derived states in flat and wrinkle regions to clarify the relationship between the spatially-resolved chemical states and the magnetism of GO, M-rGO and H-rGO. The results of X-ray magnetic circular dichroism further support the finding that C 2p(σ*)-derived states are the main origin of the magnetism of GO. Based on experimental results and first-principles calculations, the variation in magnetic behavior from GO to M-rGO and to H-rGO is interpreted, and the origin of ferromagnetism is identified as the C 2p(σ*)-derived states that involve defects/vacancies rather than the C 2p(π*) states that are bound with oxygen-containing and hydroxyl groups on GO sheets.

  14. Oxidative Stress State Is Associated with Left Ventricular Mechanics Changes, Measured by Speckle Tracking in Essential Hypertensive Patients

    Directory of Open Access Journals (Sweden)

    Luis Antonio Moreno-Ruíz

    2015-01-01

    Full Text Available The oxidative stress state is characterized by an increase in oxygen reactive species that overwhelms the antioxidant defense; we do not know if these pathological changes are correlated with alterations in left ventricular mechanics. The aim was correlating the oxidative stress state with the left ventricular global longitudinal strain (GLS and the left ventricular end diastolic pressure (LVEDP. Twenty-five patients with essential hypertension and 25 controls paired by age and gender were studied. All of the participants were subjected to echocardiography and biochemical determination of oxidative stress markers. The hypertensive patients, compared with control subjects, had significantly (p<0.05 higher levels of oxidized proteins (5.03±1.05 versus 4.06±0.63 nmol/mg, lower levels of extracellular superoxide dismutase (EC-SOD activity (0.045±0.02 versus 0.082±0.02 U/mg, higher LVEDP (16.2±4.5 versus 11.3±1.6 mm Hg, and lower GLS (−12% versus −16%. Both groups had preserved ejection fraction and the results showed a positive correlation of oxidized proteins with GLS (r=0.386, p=0.006 and LVEDP (r=0.389, p=0.005; we also found a negative correlation of EC-SOD activity with GLS (r=-0.404, p=0.004 and LVEDP (r=-0.347, p=0.014.

  15. Studi On Oxidation State Of U In Ba2NdUO6

    International Nuclear Information System (INIS)

    Firman Windarto, Hendri

    1996-01-01

    Ba 2 NdUO 6 is not of the important compounds that is formed from a solidification process for high level liquid waste using super high temperature method Ba 2 NdUO 6 has ordered perovskite structure. The objective of this study is to investigate oxidation state of U in Ba 2 NdUO 6 . The properties of Ba 2 NdUO 6 were observed by using Faraday-type torsion magnetometer and X-ray Photoelectron Spectrometer (XPS). The magnetic susceptibility measured in the temperature range of 4K to room temperature showed that the Ba 2 NdUO 6 is paramagnetism that obeys the Curie-Weiss law. The effective moment of Ba 2 NdUO 6 is 3.04 μB. The results of xPs spectrum showed that the peaks of U4f for Ba 2 NdUO 6 appeared exactly between binding energy of UO 2 and UO 3 . It can be concluded that Ba 2 NdUO 6 has binding energy peaks corresponding to pentavalent uranium

  16. Petrology of chromite in ureilites: Deconvolution of primary oxidation states and secondary reduction processes

    Science.gov (United States)

    Goodrich, Cyrena Anne; Harlow, George E.; Van Orman, James A.; Sutton, Stephen R.; Jercinovic, Michael J.; Mikouchi, Takashi

    2014-06-01

    Ureilites are ultramafic achondrites thought to be residues of partial melting on a carbon-rich asteroid. They show a trend of FeO-variation (olivine Fo from ∼74 to 95) that suggests variation in oxidation state. Whether this variation was established during high-temperature igneous processing on the ureilite parent body (UPB), or preserved from nebular precursors, is a subject of debate. The behavior of chromium in ureilites offers a way to assess redox conditions during their formation and address this issue, independent of Fo. We conducted a petrographic and mineral compositional study of occurrences of chromite (Cr-rich spinel) in ureilites, aimed at determining the origin of the chromite in each occurrence and using primary occurrences to constrain models of ureilite petrogenesis. Chromite was studied in LEW 88774 (Fo 74.2), NWA 766 (Fo 76.7), NWA 3109 (Fo 76.3), HaH 064 (Fo 77.5), LAP 03587 (Fo 74.9), CMS 04048 (Fo 76.4), LAP 02382 (Fo 78.6) and EET 96328 (Fo 85.2). Chromite occurs in LEW 88774 (∼5 vol.%), NWA 766 (event involved initial elevation of T (to 1300-1400 °C), followed by rapid decompression and drop in T (to exclusively in low-Fo samples supports the interpretation that the ureilite FeO-variation was established during igneous processing on the UPB.

  17. Waste management state-of-the-art review for mixed-oxide fuel fabrication facilities

    International Nuclear Information System (INIS)

    Woodsum, H.C.; Goodman, J.

    1977-11-01

    This report provides a state-of-the-art review of the waste management for mixed-oxide (MOX) fuel fabrication facilities. The intent of this report is to focus on those processes and regulatory issues which have a direct bearing on existing and anticipated future management of transuranic (TRU) wastes from a commercial MOX fuel fabrication faciity. Recent government agency actions are reviewed with regard to their impact on existing and projected waste management regulations; and it is concluded that acceleration in the development of regulations, standards, and criteria is one of the most important factors in the implementation of improved MOX plant waste management techniques. ERDA development programs pertaining to the management of TRU wastes have been reviewed and many promising methods for volume reduction of both solid and liquid wastes are discussed. For solid wastes, these methods include compaction, shredding and baling, combustion, acid digestion, and decontamination by electropolishing or by electrolytic treatment. For liquid wastes, treatment options include evaporation, drying, calcination, flocculation, ion exchange, filtration, reverse osmosis, combustion (of combustible organics), and bioprocessing. Based on this review, it is recommended that ERDA continue with its combustible solid waste volume reduction program and complete these development activities by 1979. Following this, a critical evaluation of solid waste volume reduction techniques should be made to select the most promising systems for a commercial MOX fuel facility

  18. Oxidation state of uranium in metamict and annealed zircon: near-infrared spectroscopic quantitative analysis

    CERN Document Server

    Zhang Ming; Ewing, R C

    2003-01-01

    Radiation and thermally induced changes in the oxidation state of uranium in metamict zircon have been systematically analysed, for the first time, using polarized near-infrared spectroscopy. The results showed that in damaged zircon U ions in crystalline domains exhibited relatively sharp, anisotropic signals from tetravalent and pentavalent U ions in crystalline domains (U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + and U sub c sub r sub y sub s sub t sub a sub l sup 5 sup +). The linewidths and peak positions of the 4834 cm sup - sup 1 band (U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + , E || c) and the 6668 cm sup - sup 1 band (U sub c sub r sub y sub s sub t sub a sub l sup 5 sup + , E perp. c) are a non-linear function of the self-radiation dose. They reach nearly constant values at doses greater than approx 3.5 x 10 sup 1 sup 8 alpha-events g sup - sup 1. Quantitative analysis of U sub c sub r sub y sub s sub t sub a sub l sup 4 sup + and U sub c sub r sub y sub s sub t sub a sub l...

  19. Atomic scale imaging of competing polar states in a Ruddlesden–Popper layered oxide

    Science.gov (United States)

    Stone, Greg; Ophus, Colin; Birol, Turan; Ciston, Jim; Lee, Che-Hui; Wang, Ke; Fennie, Craig J.; Schlom, Darrell G.; Alem, Nasim; Gopalan, Venkatraman

    2016-01-01

    Layered complex oxides offer an unusually rich materials platform for emergent phenomena through many built-in design knobs such as varied topologies, chemical ordering schemes and geometric tuning of the structure. A multitude of polar phases are predicted to compete in Ruddlesden–Popper (RP), An+1BnO3n+1, thin films by tuning layer dimension (n) and strain; however, direct atomic-scale evidence for such competing states is currently absent. Using aberration-corrected scanning transmission electron microscopy with sub-Ångstrom resolution in Srn+1TinO3n+1 thin films, we demonstrate the coexistence of antiferroelectric, ferroelectric and new ordered and low-symmetry phases. We also directly image the atomic rumpling of the rock salt layer, a critical feature in RP structures that is responsible for the competing phases; exceptional quantitative agreement between electron microscopy and density functional theory is demonstrated. The study shows that layered topologies can enable multifunctionality through highly competitive phases exhibiting diverse phenomena in a single structure. PMID:27578622

  20. Atomic scale imaging of competing polar states in a Ruddlesden-Popper layered oxide.

    Science.gov (United States)

    Stone, Greg; Ophus, Colin; Birol, Turan; Ciston, Jim; Lee, Che-Hui; Wang, Ke; Fennie, Craig J; Schlom, Darrell G; Alem, Nasim; Gopalan, Venkatraman

    2016-08-31

    Layered complex oxides offer an unusually rich materials platform for emergent phenomena through many built-in design knobs such as varied topologies, chemical ordering schemes and geometric tuning of the structure. A multitude of polar phases are predicted to compete in Ruddlesden-Popper (RP), An+1BnO3n+1, thin films by tuning layer dimension (n) and strain; however, direct atomic-scale evidence for such competing states is currently absent. Using aberration-corrected scanning transmission electron microscopy with sub-Ångstrom resolution in Srn+1TinO3n+1 thin films, we demonstrate the coexistence of antiferroelectric, ferroelectric and new ordered and low-symmetry phases. We also directly image the atomic rumpling of the rock salt layer, a critical feature in RP structures that is responsible for the competing phases; exceptional quantitative agreement between electron microscopy and density functional theory is demonstrated. The study shows that layered topologies can enable multifunctionality through highly competitive phases exhibiting diverse phenomena in a single structure.

  1. Carbonate-linked poly(ethylene oxide) polymer electrolytes towards high performance solid state lithium batteries

    International Nuclear Information System (INIS)

    He, Weisheng; Cui, Zili; Liu, Xiaochen; Cui, Yanyan; Chai, Jingchao; Zhou, Xinhong; Liu, Zhihong; Cui, Guanglei

    2017-01-01

    The classic poly(ethylene oxide) (PEO) based solid polymer electrolyte suffers from poor ionic conductivity of ambient temperature, low lithium ion transference number and relatively narrow electrochemical window (<4.0 V vs. Li + /Li). Herein, the carbonate-linked PEO solid polymer such as poly(diethylene glycol carbonate) (PDEC) and poly(triethylene glycol carbonate) (PTEC) were explored to find out the feasibility of resolving above issues. It was proven that the optimized ionic conductivity of PTEC based electrolyte reached up to 1.12 × 10 −5 S cm −1 at 25 °C with a decent lithium ion transference number of 0.39 and a wide electrochemical window about 4.5 V vs. Li + /Li. In addition, the PTEC based Li/LiFePO 4 cell could be reversibly charged and discharged at 0.05 C-rates at ambient temperature. Moreover, the higher voltage Li/LiFe 0.2 Mn 0.8 PO 4 cell (cutoff voltage 4.35 V) possessed considerable rate capability and excellent cycling performance even at ambient temperature. Therefore, these carbonate-linked PEO electrolytes were demonstrated to be fascinating candidates for the next generation solid state lithium batteries simultaneously with high energy and high safety.

  2. U.S. Natural Gas System Methane Emissions: State of Knowledge from LCAs, Inventories, and Atmospheric Measurements (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Heath, G.

    2014-04-01

    Natural gas (NG) is a potential "bridge fuel" during transition to a decarbonized energy system: It emits less carbon dioxide during combustion than other fossil fuels and can be used in many industries. However, because of the high global warming potential of methane (CH4, the major component of NG), climate benefits from NG use depend on system leakage rates. Some recent estimates of leakage have challenged the benefits of switching from coal to NG, a large near-term greenhouse gas (GHG) reduction opportunity. During this presentation, Garvin will review evidence from multiple perspectives - life cycle assessments (LCAs), inventories and measurements - about NG leakage in the US. Particular attention will be paid to a recent article in Science magazine which reviewed over 20 years of published measurements to better understand what we know about total methane emissions and those from the oil and gas sectors. Scientific and policy implications of the state of knowledge will be discussed.

  3. Thermoluminescent properties of Spinel-type oxides present in the Ternary system In2O3-TiO2-Mg O in air at 1350 degrees C

    International Nuclear Information System (INIS)

    Brown, F.; Hernandez P, T. C.; Alvarez M, V. E.; Cruz V, C.; Munoz, I. C.; Bernal, R.

    2015-10-01

    Full text: In the ternary system In 2 O 3 -TiO 2 -Mg O exists a solid solution Mg 2-x In 2x Ti 1-x O 4 (0≤ x ≤1) with spinel-type structure between MgIn 2 O 4 and Mg 2 TiO 4 (F. Brown et. al., 2000). In order to analyze their thermoluminescent (Tl) response, we obtained the spinel-type oxides with x= 0 (s1), 0.25 (s2), 0.5 (s3), 0.75 (s4), and 1 (s5) by a solid state reaction at 1350 degrees C in air. The X-ray patterns showed a spinel type structure for these compounds. The powders were exposed to beta particles from 90 Sr. The glow curve showed by s1 and s3 were hundreds of times more intense than s2, s4 and s5. At 50 Gy, s1 exhibits a main Tl maximum located at 200 degrees C, with two shoulders at 119 and 250 degrees C. The s3 oxide reveals a simple and wide glow curve at ≅195 degrees C with a Tl maximum located at 203 degrees C at 21.33 Gy. The peaks of the s1 and s3 oxide show a shift to lower temperatures and this increases its intensity as the irradiation dose increases. The lineal behavior observed for s1 and s3 were between 1.33-150 Gy and 10.66-341 Gy correspondingly, without evidence of saturation signal. After cycle 4, the s1 oxide has small variations in the relative sensitivity, with percentages below 1%. On the other hand, s3 reveals a relative sensitivity variation of 2.7%. Besides this, the standard deviation after ten consecutive irradiation-Tl readout cycles for s1 was 3.07 % and for s3 was 1%. The minimum detectable dose obtained were 0.5 Gy for s1 and 5.65 Gy for s3. These results suggest a possible application of Mg 1.5 InTi 0.5 O 4 in dosimetry. (Author)

  4. Study of oxidation states of the transition metals in a series of Prussian blue analogs using x-ray absorption near edge structure (XANES) spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Adak, S. [Department of Physics, New Mexico State University, Las Cruces, NM, 88003 (United States); Hartl, M., E-mail: monika.hartl@esss.se [European Spallation Source ESS AB, 22100, Lund (Sweden); Manuel Lujan Jr. Neutron Scattering Center (LANSCE-LC), Los Alamos National Laboratory, Los Alamos, NM, 87545 (United States); Daemen, L. [Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN, 37830 (United States); Manuel Lujan Jr. Neutron Scattering Center (LANSCE-LC), Los Alamos National Laboratory, Los Alamos, NM, 87545 (United States); Fohtung, E.; Nakotte, H. [Department of Physics, New Mexico State University, Las Cruces, NM, 88003 (United States)

    2017-01-15

    Highlights: • Systematic XANES measurements on Prussian blue analogs shows oxidation state of transition metals. • Cobal-iron bimetallic hexacyanometallates show unexpected oxidation states. • Iron(II) ions in hexacyanometallates(III) show varying spin state depending on their bond to the “N” end or “C” end of the cyanide ligand. • Thermal expansion coefficients have been linked to the XANES results. - Abstract: There have been renewed interests in metal-organic framework classes of materials such as Prussian blue analogues (PBAs) due to their potential usage in energy storage applications. In particular, due to their high surface areas, controllable structures and excellent electrochemical properties, PBAs such as hexacyanometalates M{sup II}{sub 3}[A{sup III}(CN){sub 6}]{sub 2*}nH{sub 2}O (M = Mn, Fe, Co, Ni, Cu, Zn; A = Co, Fe, Cr; n = no. of water molecules present), M{sup II}{sub 2}[Fe{sup II}(CN){sub 6}]{sub 2*}nH{sub 2}O (M = Mn, Co, Ni, Cu, Zn) and mixed hexacyanometalates(III) (Fe{sub 1-x}Co{sub x}){sub 3}[B{sup III}(CN){sub 6}]{sub 2}·nH{sub 2}O (x = 0.25, 0.5, 0.75; B = Co, Fe) could have possible usage as a new class of cathode and even anode materials for rechargeable batteries. Detailed knowledge of the oxidation states of the transition metals in PBAs is required to improve efficiency and durability of such devices. Furthermore, a link between the thermal expansion observed in these materials and the oxidation state of the transition metal is of interest to synthesize materials with a desired thermal expansion behavior, Here we demonstrate the use of Synchrotron based X-ray absorption near-edge structure (XANES) spectra to identify transition metal oxidation states. Our analysis reveals the presence of divalent, trivalent and/or mixed valence transition metals in the materials as well as high-spin and low-spin complexes.

  5. Study concerning the compatibility of the mixture of nylon-6 and poly(propylene oxide) through solid state NMR

    International Nuclear Information System (INIS)

    Tavares, Maria I.B.; Costa, D.A.; Menezes, Sonia M.C.

    1993-01-01

    NMR has been frequently used for the determination of polymers compatibility. The utilization of the simple pulse technique together with the contact time variation technique has been enabling the evaluation of the compatibility of polymeric systems. This work presents the study of the behaviour of the mixture composed by nylon-6 with poly(propylene oxide) using these techniques. Results are presented

  6. The protonation state around TyrD/TyrD• in photosystem II is reflected in its biphasic oxidation kinetics.

    Science.gov (United States)

    Sjöholm, Johannes; Ho, Felix; Ahmadova, Nigar; Brinkert, Katharina; Hammarström, Leif; Mamedov, Fikret; Styring, Stenbjörn

    2017-02-01

    The tyrosine residue D2-Tyr160 (Tyr D ) in photosystem II (PSII) can be oxidized through charge equilibrium with the oxygen evolving complex in PSII. The kinetics of the electron transfer from Tyr D has been followed using time-resolved EPR spectroscopy after triggering the oxidation of pre-reduced Tyr D by a short laser flash. After its oxidation Tyr D is observed as a neutral radical (Tyr D • ) indicating that the oxidation is coupled to a deprotonation event. The redox state of Tyr D was reported to be determined by the two water positions identified in the crystal structure of PSII [Saito et al. (2013) Proc. Natl. Acad. Sci. USA 110, 7690]. To assess the mechanism of the proton coupled electron transfer of Tyr D the oxidation kinetics has been followed in the presence of deuterated buffers, thereby resolving the kinetic isotope effect (KIE) of Tyr D oxidation at different H/D concentrations. Two kinetic phases of Tyr D oxidation - the fast phase (msec-sec time range) and the slow phase (tens of seconds time range) were resolved as was previously reported [Vass and Styring (1991) Biochemistry 30, 830]. In the presence of deuterated buffers the kinetics was significantly slower compared to normal buffers. Furthermore, although the kinetics were faster at both high pH and pD values the observed KIE was found to be similar (~2.4) over the whole pL range investigated. We assign the fast and slow oxidation phases to two populations of PSII centers with different water positions, proximal and distal respectively, and discuss possible deprotonation events in the vicinity of Tyr D . Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Rapid Synthesis of Lead Oxide Nanorods by One-step Solid-state Chemical Reaction at Room Temperature

    Institute of Scientific and Technical Information of China (English)

    CAO, Ya-Li(曹亚丽); JIA, Dian-Zeng(贾殿赠); LIU, Lang(刘浪); LUO, Jian-Min(骆建敏)

    2004-01-01

    A simple and facile method was reported to synthesize lead oxide nanorods. Nanorods of lead oxide were obtained directly from grinding solid metal salt and sodium hydroxide in agate mortar with the assistance of a suitable nonionic surfactant in only one step, which is different from the result of hydroxide in solution. The product has been characterized by XRD, TEM and SEM. The formation mechanism of rod-like morphology is discussed and the surfactant plays an important soft-template role in modifying the interface of solid-state reaction and according process of rod-formation.

  8. Investigation of electrochemical behaviour and structure of oxide films on Ni60Nb40 alloy in amorphous and crystalline states

    International Nuclear Information System (INIS)

    Tomashov, N.D.; Skvortsova, I.B.; Gorodetskij, A.E.; Bogomolov, D.B.

    1987-01-01

    Electrochemical properties of Ni 60 Nb 40 alloy in amorphous and crystalline states as well as structure of oxide films forming during anode polarization in electrolytes on the surface of this alloy in both its states are investigated. It is stated that increased passive ability of Ni 60 Nb 40 alloys in amorphous state and high efficiency of chlorine evolution (2 n NaCl+HCl up to pH=0) anode process in comparison with crystalline state are defined by increased homogeneity and uniformity of passive films forming on amorphous alloy and their increased electron conductivity, that is in direct dependence on different structure of passive films forming on alloys in amorphous and crystalline states

  9. Assigning Oxidation States to Organic Compounds via Predictions from X-Ray Photoelectron Spectroscopy: A Discussion of Approaches and Recommended Improvements

    Science.gov (United States)

    Gupta, Vipul; Ganegoda, Hasitha; Engelhard, Mark H.; Terry, Jeff; Linford, Matthew R.

    2014-01-01

    The traditional assignment of oxidation states to organic molecules is problematic. Accordingly, in 1999, Calzaferri proposed a simple and elegant solution that is based on the similar electronegativities of carbon and hydrogen: hydrogen would be assigned an oxidation state of zero when bonded to carbon. Here, we show that X-ray photoelectron…

  10. Application of ferrous-chromate and idometric titration for the determination of copper oxidation states in the superconductor YBa2Cu3Oy

    International Nuclear Information System (INIS)

    Oku, Masaoki; Kimura, Jin; Hosoya, Minoru; Takada, Kunio; Hirokawa, Kichinosuke

    1988-01-01

    Oxidation-reduction titration methods, Fe 2+ -Cr 2 O 7 2- and I - -S 2 O 3 2- , were applied to the determination of the oxidation state of copper in the superconductor YBa 2 Cu 3 O y and related compounds. The former method presented problems in the sample dissolution and titration steps. The dissolution of the sample in low concentrations of Fe 2+ -phosphoric acid and Fe 2+ -perchloric acid takes place in two steps, the oxidation of Fe 2+ to Fe 3+ and the liberation of oxygen gas, when the liberation results in low analytical values for Cu 3+ . In addition the coexistence of cuprous ion and acids induces the oxidation of ferrous ion by dissolved oxygen and air. The problems were resolved by dissolution in 0.1 mol/l Fe 2+ -phosphoric acid and titration in an argon atmosphere. The latter method gave good results by controlling the amounts of potassium chloride, the concentration of acetic acid, and by elimination of the dissolved oxygen in acetic acid solution. The results of the two titration methods coincided with each other. (orig.)

  11. The state-of-the art of produced water treatment by oxidative advanced processes; Atual estagio de desenvolvimento dos processos oxidativos avancados para o tratamento da agua produzida

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, Marcela de A.H.; Marques, Jose Jailton; Rocha, Inaura C.C. da [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Dept. de Engenharia Quimica

    2008-07-01

    The oily wastewater generated in petroleum exploration contains a sort of contaminants that may cause significant environmental impact. For this reason, the number of researchers that are looking for cleaner techniques to treat this kind of wastewater is growing. The advanced oxidation processes (AOPs) are clean and non-selective processes largely used to the treatment of wastewater containing critical substances like textile dyes, pesticides, PCBs, PAHs etc. The treatment systems using AOPs can be homogeneous or heterogeneous and they may use irradiation or not. This work presents a compilation of the results found by many researchers involving AOPs potentially applicable to the treatment of produced water, as follow: H{sub 2}O{sub 2}/UV, H{sub 2}O{sub 2} / Fe{sup 2+} / UV, O{sub 3}/UV, O{sub 3}/ H{sub 2}O{sub 2} etc., showing the state-of-art of oxidation advanced processes. (author)

  12. Oxidation of organic compounds in wastewater from the humid processing of coffee berries; Materiais a base de oxido de ferro para oxidacao de compostos presentes no efluente da despolpa do cafe

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Maraisa; Guerreiro, Mario Cesar; Oliveira, Luiz Carlos Alves; Rocha, Cristian Luciana da [Universidade Federal de Lavras, MG (Brazil). Dept. de Quimica]. E-mail: guerrero@ufla.br

    2008-07-01

    Materials based on pure iron oxide and impregnated with niobia (Nb{sub 2}O{sub 5}) were prepared. Their catalytic activities were tested on the oxidation of compounds present in the wastewater from the processing of coffee berries. Particularly caffeine and catechol were tested. The oxidation reactions were carried out with the following systems: UV/H{sub 2}O{sub 2}; photo-Fenton and heterogeneous Fenton. All materials were characterized with X-ray diffraction, Moessbauer and infrared spectroscopy. Iron was mainly in the forms of goethite and maghemite. The oxidation kinetics were monitored by UV-vis and the oxidation products were monitored by mass spectrometry. The photo-Fenton reaction presented highest oxidation efficiency, removing 98% of all caffeine and catechol contents. (author)

  13. A state-of-the-art review on nitrous oxide control from waste treatment and industrial sources.

    Science.gov (United States)

    Frutos, Osvaldo D; Quijano, Guillermo; Aizpuru, Aitor; Muñoz, Raúl

    2018-03-20

    This review aims at holistically analyzing the environmental problems associated with nitrous oxide (N 2 O) emissions by evaluating the most important sources of N 2 O and its environmental impacts. Emissions from wastewater treatment processes and the industrial production of nitric and adipic acid represent nowadays the most important anthropogenic point sources of N 2 O. Therefore, state-of-the-art strategies to mitigate the generation and release to the atmosphere of this greenhouse and O 3 -depleting gas in the waste treatment and industrial sectors are also reviewed. An updated review of the end-of-the-pipe technologies for N 2 O abatement, both in the waste treatment and industrial sectors, is herein presented and critically discussed for the first time. Despite the consistent efforts recently conducted in the development of cost-efficient and eco-friendly N 2 O abatement technologies, physical/chemical technologies still constitute the most popular treatments for the control of industrial N 2 O emissions at commercial scale. The recent advances achieved on biological N 2 O abatement based on heterotrophic denitrification have opened new opportunities for the development of eco-friendly alternatives for the treatment of N 2 O emissions. Finally, the main limitations and challenges faced by these novel N 2 O abatement biotechnologies are identified in order to pave the way for market implementation. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Triplet-State Dissolved Organic Matter Quantum Yields and Lifetimes from Direct Observation of Aromatic Amine Oxidation.

    Science.gov (United States)

    Schmitt, Markus; Erickson, Paul R; McNeill, Kristopher

    2017-11-21

    Excited triplet state chromophoric dissolved organic matter ( 3 CDOM*) is a short-lived mixture of excited-state species that plays important roles in aquatic photochemical processes. Unlike the study of the triplet states of well-defined molecules, which are amenable to transient absorbance spectroscopy, the study of 3 CDOM* is hampered by it being a complex mixture and its low average intersystem crossing quantum yield (Φ ISC ). This study is an alternative approach to investigating 3 CDOM* using transient absorption laser spectroscopy. The radical cation of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD), formed through oxidation by 3 CDOM*, was directly observable by transient absorption spectroscopy and was used to probe basic photophysical properties of 3 CDOM*. Quenching and control experiments verified that TMPD •+ was formed from 3 CDOM* under anoxic conditions. Model triplet sensitizers with a wide range of excited triplet state reduction potentials and CDOM oxidized TMPD at near diffusion-controlled rates. This gives support to the idea that a large cross-section of 3 CDOM* moieties are able to oxidize TMPD and that the complex mixture of 3 CDOM* can be simplified to a single signal. Using the TMPD •+ transient, the natural triplet lifetime and Φ ISC for different DOM isolates and natural waters were quantified; values ranged from 12 to 26 μs and 4.1-7.8%, respectively.

  15. Facile and efficient room temperature solid state reaction enabled synthesis of antimony nanoparticles embedded within reduced graphene oxide for enhanced sodium-ion storage

    Science.gov (United States)

    Zhang, Xiukui; Wu, Ping; Jiang, Li; Zhang, Xiaofang; Shi, Hongxia; Zhu, Xiaoshu; Wei, Shaohua; Zhou, Yiming

    2018-06-01

    Herein, a very simple and cost-effective solid state reaction method is employed to obtain, for the first time, the antimony nanoparticles embedded within reduced graphene oxide matrices (designated as Sb/rGO). By directly grinding antimony chloride and sodium hydroxide together at room temperature in the presence of graphene oxide (GO), Sb4O5Cl2 precursor was quickly obtained, which is evenly incorporated in the graphene oxide matrices. After subsequent chemical reduction by NaBH4, the Sb/rGO composite was successfully synthesized. The as-prepared Sb/rGO composite consists of uniform Sb nanoparticles of sub-20 nm, all of which have been wrapped in and protected by the rGO matrices. The Sb nanoparticles serve as a sufficient sodium ion reservoir while the rGO matrices provide highly efficient pathways for transport of sodium ions and electrons. Moreover, the volume expansion of Sb during sodiation can be buffered in the rGO matrices. As a result, the Sb/rGO composite exhibits excellent electrochemical performance in sodium-ion batteries (SIBs), including an enhanced cycling stability with a highly reversible charge capacity of 455 mA h g-1 after 45 cycles at 100 mA g-1, and a coulombic efficiency exceeding 98% during cycling. The findings in the present work pave the way to not only synthesize the designated promising electrode materials for high performance SIBs, but also thoroughly understand the solid-state reaction.

  16. [Utilization of a transferred arc-plasma rotating furnace to melt and found oxide mixtures at around 2000 degrees C (presentation of the film VULCANO)].

    Science.gov (United States)

    Cognet, G; Laffont, G; Jegou, C; Pierre, J; Journeau, C; Sudreau, F; Roubaud, A

    1999-03-01

    Unless security measures are taken, a hypothetical accident resulting from the loss of the cooling circuit in a pressurized water nuclear reactor could cause the heart of the reactor to melt forming a bath, called the corium, mainly composed of uranium, zirconium and iron oxides as well as the structural steel. This type of situation would be similar to the Three Mile Island accident in 1979. In order to limit the consequences of such an accident, the Atomic Energy Commission has implemented a large study program [1] to improve our understanding of corium behavior and determine solutions to stabilize it and avoid its propagation outside the unit. The VULCANO installation was designed in order to perform the trials using real materials which are indispensable to study all the phenomena involved. A film on the VULCANO trials was presented at the Henri Moissan commemorative session organized by the French National Academy of Pharmacy. The rotating furnace used to melt and found the mixture simulating the corium is a direct descendant of the pioneer work by Henri Moissan. An electrical arc is directed at the center of the load to melt which is maintained against the walls by centrifugal force. After six high-temperature trials performed with compositions without uranium oxide, the first trial with real corium showed that the magma spread rather well, a result which is quite favorable for cooling.

  17. Metabolomic profiles of arsenic (+3 oxidation state) methyltransferase knockout mice: Effect of sex and arsenic exposure

    Science.gov (United States)

    Huang, Madelyn C.; Douillet, Christelle; Su, Mingming; Zhou, Kejun; Wu, Tao; Chen, Wenlian; Galanko, Joseph A.; Drobná, Zuzana; Saunders, R. Jesse; Martin, Elizabeth; Fry, Rebecca C.; Jia, Wei; Stýblo, Miroslav

    2016-01-01

    Arsenic (+3 oxidation state) methyltransferase (As3mt) is the key enzyme in the pathway for methylation of inorganic arsenic (iAs). Altered As3mt expression and AS3MT polymorphism have been linked to changes in iAs metabolism and in susceptibility to iAs toxicity in laboratory models and in humans. As3mt-knockout mice have been used to study the association between iAs metabolism and adverse effects of iAs exposure. However, little is known about systemic changes in metabolism of these mice and how these changes lead to their increased susceptibility to iAs toxicity. Here, we compared plasma and urinary metabolomes of male and female wild-type (WT) and As3mt-KO (KO) C57BL6 mice and examined metabolomic shifts associated with iAs exposure in drinking water. Surprisingly, exposure to 1 ppm As elicited only small changes in the metabolite profiles of either WT or KO mice. In contrast, comparisons of KO mice with WT mice revealed significant differences in plasma and urinary metabolites associated with lipid (phosphatidylcholines, cytidine, acyl-carnitine), amino acid (hippuric acid, acetylglycine, urea), and carbohydrate (L-sorbose, galactonic acid, gluconic acid) metabolism. Notably, most of these differences were sex-specific. Sex-specific differences were also found between WT and KO mice in plasma triglyceride and lipoprotein cholesterol levels. Some of the differentially changed metabolites (phosphatidylcholines, carnosine, and sarcosine) are substrates or products of reactions catalyzed by other methyltransferases. These results suggest that As3mt KO alters major metabolic pathways in a sex-specific manner, independent of iAs treatment, and that As3mt may be involved in other cellular processes beyond iAs methylation. PMID:26883664

  18. A Singular Perturbation Problem for Steady State Conversion of Methane Oxidation in Reverse Flow Reactor

    Directory of Open Access Journals (Sweden)

    Aang Nuryaman

    2012-11-01

    Full Text Available The governing equations describing the methane oxidation process in reverse flow reactor are given by a set of convective-diffusion equations with a nonlinear reaction term, where temperature and methane conversion are dependent variables. In this study, the process is assumed to be one-dimensional pseudo homogeneous model and takes place with a certain reaction rate in which the whole process of reactor is still workable. Thus, the reaction rate can proceed at a fixed temperature. Under this condition, we restrict ourselves to solve the equations for the conversion only. From the available data, it turns out that the ratio of the diffusion term to the reaction term is small. Hence, this ratio is considered as small parameter in our model and this leads to a singular perturbation problem. In the vicinity of small parameter in front of higher order term, the numerical difficulties will be found. Here, we present an analytical solution by means of matched asymptotic expansions. Result shows that, up to and including the first order of approximation, the solution is in agreement with the exact and numerical solutions of the boundary value problem.

  19. Determination of Pu Oxidation states in the HCl Media Using with UV-Visible Absorption Spectroscopic Techniques

    International Nuclear Information System (INIS)

    Lee, Myung Ho; Suh, Mu Yeol; Park, Kyoung Kyun; Park, Yeong Jae; Kim, Won Ho

    2006-01-01

    The spectroscopic characteristics of Pu (III, IV, V, VI) in the HCl media were investigated by measuring Pu oxidation states using a UV-Vis-NIR spectrophotometer (400-1200 nm) after adjusting Pu oxidation states with oxidation/reduction reagents. Pu in stock solution was reduced to Pu(III) with NH 2 OH · HCl, and oxidized to Pu(IV) and Pu(VI) with NaNO 2 and HCIO 4 , respectively. Also, Pu(V) was adjusted in the Pu(VI) solution with NH 2 OH · HCl. The major absorption peaks of Pu (IV) and Pu(III) were measured in the 470 nm and 600 nm, respectively. The major absorption peaks of Pu (VI) and Pu(V) were measured in the 830 nm and 1135 nm, respectively. There was not found to be significant changes of UV-V is absorption spectra for Pu(III), Pu(IV) and Pu(VI) with aging time, except that an unstable Pu(V) immediately reduced to Pu(III).

  20. V6O13 films by control of the oxidation state from aqueous precursor to crystalline phase.

    Science.gov (United States)

    Peys, Nick; Ling, Yun; Dewulf, Daan; Gielis, Sven; De Dobbelaere, Christopher; Cuypers, Daniel; Adriaensens, Peter; Van Doorslaer, Sabine; De Gendt, Stefan; Hardy, An; Van Bael, Marlies K

    2013-01-28

    An aqueous deposition process for V(6)O(13) films is developed whereby the vanadium oxidation state is continuously controlled throughout the entire process. In the precursor stage, a controlled wet chemical reduction of the vanadium(V) source with oxalic acid is achieved and monitored by (51)Vanadium Nuclear Magnetic Resonance ((51)V-NMR) and Ultraviolet-Visible (UV-Vis) spectroscopy. The resulting vanadium(IV) species in the aqueous solution are identified as mononuclear citrato-oxovanadate(IV) complexes by Electron Paramagnetic Resonance (EPR) and Fourier Transform Infra-Red (FTIR) spectroscopy. This precursor is successfully employed for the deposition of uniform, thin films. The optimal deposition and annealing conditions for the formation of crystalline V(6)O(13), including the control of the vanadium oxidation state, are determined through an elaborate study of processing temperature and O(2) partial pressure. To ensure a sub 100 nm adjustable film thickness, a non-oxidative intermediate thermal treatment is carried out at the end of each deposition cycle, allowing maximal precursor decomposition while still avoiding V(IV) oxidation. The resulting surface hydrophilicity, indispensable for the homogeneous deposition of the next layer, is explained by an increased surface roughness and the increased availability of surface vanadyl groups. Crystalline V(6)O(13) with a preferential (002) orientation is obtained after a post deposition annealing in a 0.1% O(2) ambient for thin films with a thickness of 20 nm.

  1. A Semi-Analytical Extraction Method for Interface and Bulk Density of States in Metal Oxide Thin-Film Transistors.

    Science.gov (United States)

    Chen, Weifeng; Wu, Weijing; Zhou, Lei; Xu, Miao; Wang, Lei; Ning, Honglong; Peng, Junbiao

    2018-03-11

    A semi-analytical extraction method of interface and bulk density of states (DOS) is proposed by using the low-frequency capacitance-voltage characteristics and current-voltage characteristics of indium zinc oxide thin-film transistors (IZO TFTs). In this work, an exponential potential distribution along the depth direction of the active layer is assumed and confirmed by numerical solution of Poisson's equation followed by device simulation. The interface DOS is obtained as a superposition of constant deep states and exponential tail states. Moreover, it is shown that the bulk DOS may be represented by the superposition of exponential deep states and exponential tail states. The extracted values of bulk DOS and interface DOS are further verified by comparing the measured transfer and output characteristics of IZO TFTs with the simulation results by a 2D device simulator ATLAS (Silvaco). As a result, the proposed extraction method may be useful for diagnosing and characterising metal oxide TFTs since it is fast to extract interface and bulk density of states (DOS) simultaneously.

  2. A Semi-Analytical Extraction Method for Interface and Bulk Density of States in Metal Oxide Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Weifeng Chen

    2018-03-01

    Full Text Available A semi-analytical extraction method of interface and bulk density of states (DOS is proposed by using the low-frequency capacitance–voltage characteristics and current–voltage characteristics of indium zinc oxide thin-film transistors (IZO TFTs. In this work, an exponential potential distribution along the depth direction of the active layer is assumed and confirmed by numerical solution of Poisson’s equation followed by device simulation. The interface DOS is obtained as a superposition of constant deep states and exponential tail states. Moreover, it is shown that the bulk DOS may be represented by the superposition of exponential deep states and exponential tail states. The extracted values of bulk DOS and interface DOS are further verified by comparing the measured transfer and output characteristics of IZO TFTs with the simulation results by a 2D device simulator ATLAS (Silvaco. As a result, the proposed extraction method may be useful for diagnosing and characterising metal oxide TFTs since it is fast to extract interface and bulk density of states (DOS simultaneously.

  3. Present State of Knowledge of the Upper Atmosphere 1996: An Assessment Report to Congress and the Environmental Protection Agency

    Science.gov (United States)

    Kurylo, M. J.; Kaye, J. A.; Decola, P. L.; Friedl, R. R.; Peterson, D. B.

    1997-01-01

    This document is issued in response to the Clean Air Act Amendment of 1990, Public Law 101-549, which mandates that the National Aeronautics and Space Administration (NASA) and other key agencies submit triennial report to congress and the Environmental Protection Agency. NASA is charged with the responsibility to report on the state of our knowledge of the Earth's upper atmosphere, particularly the Stratosphere. Part 1 of this report summarizes the objectives, status, and accomplishments of the research tasks supported under NASA's Upper Atmosphere Research Program and Atmospheric Chemistry Modeling and Analysis Program for the period of 1994-1996. Part 2 (this document) presents summaries of several scientific assessments, reviews, and summaries. These include the executive summaries of two scientific assessments: (Section B) 'Scientific Assessment of Ozone Depletion: 1994'; (Section C) 'l995 Scientific Assessment of the Atmospheric Effects of Stratospheric Aircraft); end of mission/series statements for three stratospherically-focused measurement campaigns: (Section D) 'ATLAS End-of-Series Statement'; (Section E) 'ASHOE/MAESA End-of-Mission Statement'; (Section F) 'TOTE/VOTE End-of-Mission Statement'; a summary of NASA's latest biennial review of fundamental photochemical processes important to atmospheric chemistry 'Chemical Kinetics and Photochemical Data for Use in Stratospheric Modeling'; and (Section H) the section 'Atmospheric Ozone Research" from the Mission to Planet Earth Science Research Plan, which describes NASA's current and future research activities related to both tropospheric and stratospheric chemistry.

  4. Molecular water oxidation catalysis

    CERN Document Server

    Llobet, Antoni

    2014-01-01

    Photocatalytic water splitting is a promising strategy for capturing energy from the sun by coupling light harvesting and the oxidation of water, in order to create clean hydrogen fuel. Thus a deep knowledge of the water oxidation catalysis field is essential to be able to come up with useful energy conversion devices based on sunlight and water splitting. Molecular Water Oxidation Catalysis: A Key Topic for New Sustainable Energy Conversion Schemes presents a comprehensive and state-of-the-art overview of water oxidation catalysis in homogeneous phase, describing in detail the most importan

  5. The oxidation of mild steel in high pressure CO2. Paper presented to the Nuclear Engineering Society on Tuesday, 15 November 1977

    International Nuclear Information System (INIS)

    Gleave, C.

    1977-01-01

    The mechanisms of oxidation of mild steels in high pressure carbon dioxide is elucidated. Rimming steel was oxidized sequentially in C 160 2, at 4.1 MPa and 500 0 C. C 180 2 was used as a tracer gas. The distribution of the 18 0 in the oxide scales could be determined by nuclear micro-analytical techniques in order to determine the oxide growth in both protective and breakaway oxide scales. The examination of the data from weight gains and both nuclear and metallurgical techniques is described and discussed. Several conclusions are drawn to explain the mechanism of the corrosion. (U.K.)

  6. Dissolving method for nuclear fuel oxide

    International Nuclear Information System (INIS)

    Tomiyasu, Hiroshi; Kataoka, Makoto; Asano, Yuichiro; Hasegawa, Shin-ichi; Takashima, Yoichi; Ikeda, Yasuhisa.

    1996-01-01

    In a method of dissolving oxides of nuclear fuels in an aqueous acid solution, the oxides of the nuclear fuels are dissolved in a state where an oxidizing agent other than the acid is present together in the aqueous acid solution. If chlorate ions (ClO 3 - ) are present together in the aqueous acid solution, the chlorate ions act as a strong oxidizing agent and dissolve nuclear fuels such as UO 2 by oxidation. In addition, a Ce compound which generates Ce(IV) by oxidation is added to the aqueous acid solution, and an ozone (O 3 ) gas is blown thereto to dissolve the oxides of nuclear fuels. Further, the oxides of nuclear fuels are oxidized in a state where ClO 2 is present together in the aqueous acid solution to dissolve the oxides of nuclear fuels. Since oxides of the nuclear fuels are dissolved in a state where the oxidizing agent is present together as described above, the oxides of nuclear fuels can be dissolved even at a room temperature, thereby enabling to use a material such as polytetrafluoroethylene and to dissolve the oxides of nuclear fuels at a reduced cost for dissolution. (T.M.)

  7. Solid-phase extraction of plutonium in various oxidation states from simulated groundwater using N-benzoylphenylhydroxylamine

    International Nuclear Information System (INIS)

    Perevalov, S.A.; Malofeeva, G.I.; Kuzovkina, E.V.; Spivakov, B.Ya.

    2013-01-01

    Solid-phase extraction of plutonium in different individual and mixed oxidation states from simulated groundwater (pH 8.5) was studied. The extraction of plutonium species was carried out in a dynamic mode using DIAPAK C16 cartridges modified by N-benzoylphenylhydroxylamine (BPHA). It was shown that the extent of recovery depends on the oxidation state of plutonium. The extraction of Pu(IV) was at the level of 98-99% regardless of the volume and flow-rate of the sample solution. Pu(V) was extracted by 90-95% and 75-80% from 10- and 100-mL aliquots of the samples, respectively, whereas the extraction of Pu(VI) did not exceed 45-50%. An equimolar mixture of Pu(IV), Pu(V), and Pu(VI) was extracted by 74%. The distribution coefficients (K d ) and kinetic exchange capacities (S) of plutonium in various oxidation states were measured. It was found that during the sorption process, Pu(V) was reduced to Pu(IV) by 80-90% after an hour-long contact with the solid phase. Pu(VI) is reduced to Pu(V) by 34% and to Pu(IV) by 55%. In the case of mixed-valent solution of plutonium, only Pu(V) and Pu(IV) were found in the effluents. (author)

  8. Homoleptic Ce(III) and Ce(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State

    Energy Technology Data Exchange (ETDEWEB)

    Bogart, Justin A.; Lewis, Andrew J.; Medling, Scott A.; Piro, Nicholas A.; Carroll, Patrick J.; Booth, Corwin H.; Schelter, Eric J.

    2014-06-25

    Electrochemical experiments performed on the complex Ce-IV[2-((BuNO)-Bu-t)py](4), where [2-((BuNO)-Bu-t)py](-) = N-tert-butyl-N-2-pyridylnitroxide, indicate a 2.51 V stabilization of the 4+ oxidation state of Ce compared to [(Bu4N)-Bu-n](2)[Ce(NO3)(6)] in acetonitrile and a 2.95 V stabilization compared to the standard potential for the ion under aqueous conditions. Density functional theory calculations suggest that this preference for the higher oxidation state is a result of the tetrakis(nitroxide) ligand framework at the Ce cation, which allows for effective electron donation into, and partial covalent overlap with, vacant 4f orbitals with delta symmetry. The results speak to the behavior of CeO2 and related solid solutions in oxygen uptake and transport applications, in particular an inherent local character of bonding that stabilizes the 4+ oxidation state. The results indicate a cerium(IV) complex that has been stabilized to an unprecedented degree through tuning of its ligand-field environment.

  9. Plutonium uptake by the green alga Scenedesmus obliquus (Turp) Kutz, as a function of isotope and oxidation state

    Energy Technology Data Exchange (ETDEWEB)

    Tkacik, M.F.

    1977-01-01

    This study was designed to determine the effect of plutonium chemical valence state on the availability of small concentrations of /sup 238/Pu and /sup 239/Pu to algae. The uptake experiments involved the green alga Scenedesmus obliquus, grown in batch cultures. Plutonium concentrations accumulated by this alga were linearly related to plutonium concentrations. There was no significant difference (rho = 0.05) in algal plutonium accumulations, on a mass basis, of either /sup 238/Pu or /sup 239/Pu in either Pu/sup +4/ or Pu/sup +6/ oxidation state at the concentrations studied.

  10. Plutonium uptake by the green alga Scenedesmus obliquus (Turp) Kutz, as a function of isotope and oxidation state

    International Nuclear Information System (INIS)

    Tkacik, M.F.

    1977-01-01

    This study was designed to determine the effect of plutonium chemical valence state on the availability of small concentrations of 238 Pu and 239 Pu to algae. The uptake experiments involved the green alga Scenedesmus obliquus, grown in batch cultures. Plutonium concentrations accumulated by this alga were linearly related to plutonium concentrations. There was no significant difference (rho = 0.05) in algal plutonium accumulations, on a mass basis, of either 238 Pu or 239 Pu in either Pu +4 or Pu +6 oxidation state at the concentrations studied

  11. Lessons learned and present day challenges of addressing 20th century radiation legacies of Russia and the United States

    International Nuclear Information System (INIS)

    Rengel, M.T.; Kristofzski, J.G.; Schubert, A.L.

    2002-01-01

    Decommissioning of nuclear submarines, disposal of highly enriched uranium and defense plutonium as well as processing of high-level wastes are among the most challenging issues of addressing radiation legacy of the 20th century. USA and Russia are the two primary countries that have to deal with the challenge and where most of the fissile materials to be processed are concentrated, nuclear fuel and high-level radioactive waste are stored, and multiple industrial sites and nuclear weapons production facilities are located. In the US, CH2M HILL is managing two of the most important nuclear projects being conducted by the US Department of Energy at the Rocky Flats Environmental Technology Site and at the DOE Hanford Site (177 underground tanks at this site contain 60 percent of the United States' high-level radioactive wastes). Within the framework of the Russian Federal special program 'Radioactive Waste and Spent Nuclear Materials Management, Utilization and Disposal for 1996-2005' works were carried out on the Karachai lake covering with soil, highly active radwaste vitrification and fractionation at the 'Mayak' combine. Currently there is a discussion of launching joint Russian-American initiatives including comparative studies of environmental and public health impacts from high-level waste vitrification and plutonium stabilization processes in Russia and high-level waste removal from tanks in the USA and of continuing comprehensive research with the RADSITE project (USA, European Union, Japan, China and India) using coordinated approaches in 2000-2003. This paper presents comparative studies, technical approaches, and regulatory strategies to address the challenges of managing and closing highly enriched uranium, plutonium, and high level waste sites. (author)

  12. Youth Versus Adult “Weightlifting” Injuries Presenting to United States Emergency Rooms: Accidental Versus Nonaccidental Injury Mechanisms

    Science.gov (United States)

    Myer, Gregory D.; Quatman, Carmen E.; Khoury, Jane; Wall, Eric J.; Hewett, Timothy E.

    2014-01-01

    Myer, GD, Quatman, CE, Khoury, J, Wall, EJ, and Hewett, TE. Youth versus adult “weightlifting” injuries presenting to united states emergency rooms: accidental versus nonaccidental injury mechanisms. J Strength Cond Res 23(7): 2054–2060, 2009—Resistance training has previously been purported to be unsafe and ineffective in children. The purpose of this investigation was to evaluate resistance training-related injuries presenting to U.S. emergency rooms by age, type, and mechanism of injury. We hypothesized that older athletes would sustain greater percentages of joint sprains and muscle strains, whereas younger athletes would sustain a greater percentage of accidental injuries that would result in an increased percentage of fractures in youths. The U.S. Consumer Product Safety Commission (CPSC) National Electronic Injury Surveillance System was queried from 2002 to 2005 using the CPSC code for “Weightlifting.” Subjects between the ages of 8 and 30 were grouped by age categories 8 to 13 (elementary/middle school age), 14 to 18 (high school), 19 to 22 (college), and 23 to 30 (adult). Injuries were classified as “accidental” if caused by dropped weight or improper equipment use. Multiple logistic regression was used to compare accidental injuries between age groups. The sample consisted of 4, 111 patients. Accidental injuries decreased (p 14 to 18 > 19 to 22 years = 23 to 30 years. Conversely, sprain/strain injuries increased in each successive age group (p injuries (n = 2, 565) showed that the oldest categories (19–22 and 23–30 yr) demonstrated a greater percentage of sprains and strains relative to younger age categories (p injuries sustained in the 8 to 13 group were to the hand and foot and were most often related to “dropping” and “pinching” in the injury descriptions, and there was an increased percentage of fractures in the 8 to 13 group relative to all other groups (p injuries are the result of accidents that are potentially

  13. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Cr, Mn, Fe, Co and Ni

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, Mark C., E-mail: biesingr@uwo.ca [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia); Payne, Brad P. [Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Grosvenor, Andrew P. [Department of Chemistry, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C9 (Canada); Lau, Leo W.M. [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Gerson, Andrea R.; Smart, Roger St.C. [ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2011-01-15

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of their 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. Our previous paper [M.C. Biesinger et al., Appl. Surf. Sci. 257 (2010) 887-898.] in which we examined Sc, Ti, V, Cu and Zn species, has shown that all the values of the spectral fitting parameters for each specific species, i.e. binding energy (eV), full wide at half maximum (FWHM) value (eV) for each pass energy, spin-orbit splitting values and asymmetric peak shape fitting parameters, are not all normally provided in the literature and data bases, and are necessary for reproducible, quantitative chemical state analysis. A more consistent, practical and effective approach to curve fitting was developed based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of literature references and (3) specific literature references where fitting procedures are available. This paper extends this approach to the chemical states of Cr, Mn, Fe, Co and Ni metals, and various oxides and hydroxides where intense, complex multiplet splitting in many of the chemical states of these elements poses unique difficulties for chemical state analysis. The curve fitting procedures proposed use the same criteria as proposed previously but with the additional complexity of fitting of multiplet split spectra which has been done based on spectra of numerous reference materials and theoretical XPS modeling of these transition metal species. Binding energies, FWHM values, asymmetric peak shape fitting parameters, multiplet peak separation and peak area percentages are presented. The procedures developed can be utilized to remove uncertainties in the analysis of surface states in nano

  14. Shock compression of strongly correlated oxides: A liquid-regime equation of state for cerium(IV) oxide

    Science.gov (United States)

    Weck, Philippe F.; Cochrane, Kyle R.; Root, Seth; Lane, J. Matthew D.; Shulenburger, Luke; Carpenter, John H.; Sjostrom, Travis; Mattsson, Thomas R.; Vogler, Tracy J.

    2018-03-01

    The shock Hugoniot for full-density and porous CeO2 was investigated in the liquid regime using ab initio molecular dynamics (AIMD) simulations with Erpenbeck's approach based on the Rankine-Hugoniot jump conditions. The phase space was sampled by carrying out NVT simulations for isotherms between 6000 and 100 000 K and densities ranging from ρ =2.5 to 20 g /cm3 . The impact of on-site Coulomb interaction corrections +U on the equation of state (EOS) obtained from AIMD simulations was assessed by direct comparison with results from standard density functional theory simulations. Classical molecular dynamics (CMD) simulations were also performed to model atomic-scale shock compression of larger porous CeO2 models. Results from AIMD and CMD compression simulations compare favorably with Z-machine shock data to 525 GPa and gas-gun data to 109 GPa for porous CeO2 samples. Using results from AIMD simulations, an accurate liquid-regime Mie-Grüneisen EOS was built for CeO2. In addition, a revised multiphase SESAME-type EOS was constrained using AIMD results and experimental data generated in this work. This study demonstrates the necessity of acquiring data in the porous regime to increase the reliability of existing analytical EOS models.

  15. Heavy metals and manganese oxides in the genesee watershed, New York state: effects of geology and land use

    Science.gov (United States)

    Whitney, P.R.

    1981-01-01

    Manganese oxide coatings on gravels from 255 sites on tributary streams in the Genesee River Watershed were analyzed for Mn, Fe, Zn, Cd, Co, Ni, Pb, and Cu. The results were compared with data on bedrock geology, surficial geology and land use, using factor analysis and stepwise multiple regression. All metals except Pb show strong positive correlation with Mn. This association results from the well-known tendency of Mn oxide precipitates to adsorb and incorporate dissolved trace metals. Pb may be present in a separate phase on the gravel surfaces; alternatively Pb abundance may be so strongly influenced by environmental factors that the effect of varying abundance of the carrier phase becomes relatively unimportant. When the effects of varying Mn abundance are allowed for, Pb and to a lesser extent Zn and Cu abundances are seen to be related to commercial, industrial and residential land use. In addition to this pollution effect, all the trace metals, Cd and Ni most strongly, tend to be more abundant in oxide coatings from streams in the forested uplands in the southern part of the area. This probably reflects increased geochemical mobility of the metals in the more acid soils and groundwater of the southern region. A strong Zn anomaly is present in streams draining areas underlain by the Lockport Formation. Oxide coatings in these streams contain up to 5% Zn, originating from disseminated sphalerite in the Lockport and secondary Zn concentrations in the overlying muck soils. The same group of metals, plus calcium and loss on ignition, were determined in the silt and clay (minus 230 mesh) fraction of stream sediments from 129 of the same sites, using a hot nitric acid leach. The amounts of manganese in the sediments are low (average 1020 ppm) and manganese oxides are, at most, of relatively minor significance in the trace-metal geochemistry of these sediments. The bulk of the trace metals in sediment appears to be associated with iron oxides, clays and organic

  16. Generic origin of subgap states in transparent amorphous semiconductor oxides illustrated for the cases of In-Zn-O and In-Sn-O

    Energy Technology Data Exchange (ETDEWEB)

    Koerner, Wolfgang; Urban, Daniel F.; Elsaesser, Christian [Fraunhofer Institute for Mechanics of Materials IWM, Woehlerstr. 11, 79108, Freiburg (Germany)

    2015-07-15

    We present a microscopic interpretation for the appearance and behaviour of subgap states in stoichiometric and oxygen-deficient, amorphous In-Zn-O (a-IZO) and In-Sn-O (a-ITO) derived from a density functional theory analysis using a self-interaction-correction scheme. Our findings concerning the defect structures and the resulting deep levels are qualitatively similar to earlier results on a-IGZO and a-ZTO and in agreement with recent experimental results. Based on our extensive set of DFT results for In-, Sn-, Zn- based oxides we develop a general concept of the subgap states which is applicable to these systems. Electronic defect levels in the lower half of the band gap are created by undercoordinated oxygen atoms while local oxygen deficiencies cause defect levels in the upper part of the band gap. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Generic origin of subgap states in transparent amorphous semiconductor oxides illustrated for the cases of In-Zn-O and In-Sn-O

    International Nuclear Information System (INIS)

    Koerner, Wolfgang; Urban, Daniel F.; Elsaesser, Christian

    2015-01-01

    We present a microscopic interpretation for the appearance and behaviour of subgap states in stoichiometric and oxygen-deficient, amorphous In-Zn-O (a-IZO) and In-Sn-O (a-ITO) derived from a density functional theory analysis using a self-interaction-correction scheme. Our findings concerning the defect structures and the resulting deep levels are qualitatively similar to earlier results on a-IGZO and a-ZTO and in agreement with recent experimental results. Based on our extensive set of DFT results for In-, Sn-, Zn- based oxides we develop a general concept of the subgap states which is applicable to these systems. Electronic defect levels in the lower half of the band gap are created by undercoordinated oxygen atoms while local oxygen deficiencies cause defect levels in the upper part of the band gap. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Electrocatalytic oxidation of methanol by the [Ru3O(OAc6(py2(CH3OH]3+cluster: improving the metal-ligand electron transfer by accessing the higher oxidation states of a multicentered system

    Directory of Open Access Journals (Sweden)

    Henrique E. Toma

    2010-01-01

    Full Text Available The [Ru3O(Ac6(py2(CH3OH]+ cluster provides an effective electrocatalytic species for the oxidation of methanol under mild conditions. This complex exhibits characteristic electrochemical waves at -1.02, 0.15 and 1.18 V, associated with the Ru3III,II,II/Ru3III,III,II/Ru 3III,III,III /Ru3IV,III,III successive redox couples, respectively. Above 1.7 V, formation of two RuIV centers enhances the 2-electron oxidation of the methanol ligand yielding formaldehyde, in agreement with the theoretical evolution of the HOMO levels as a function of the oxidation states. This work illustrates an important strategy to improve the efficiency of the oxidation catalysis, by using a multicentered redox catalyst and accessing its multiple higher oxidation states.

  19. Reversal magnetization dependence with the Cr and Fe oxidation states in YFe1−xCrxO3 (0≤x≤1) perovskites

    International Nuclear Information System (INIS)

    Fabian, F.A.; Pedra, P.P.; Moura, K.O.; Duque, J.G.S.; Meneses, C.T.

    2016-01-01

    In this work, we have carried out a detailed study of the magnetic and structural properties of YFe 1−x Cr x O 3 (0≤x≤1) samples with orthorhombic structure obtained by co-precipitation method. Analysis of X-ray diffraction data using Rietveld refinement show that all samples present an orthorhombic crystal system with space group Pnma. Besides, we have observed a reduction of unit cell volume with increasing of the Cr concentration. SEM images show the formation of grains of micrometer order. X-ray Absorption near edge spectroscopy (XANES) measurements show a shift of absorption edge which can be indicate there is (i) different oxidation states to Fe and Cr ions and/or (ii) a changing in the point symmetry of Fe and Cr ions to the compounds. The magnetization measurements indicate a continuous decreasing of the magnetic transition temperature as function of chromium doping. The reversal magnetization effect was observed to concentrations around x=0.5. Besides, the deviation of the Curie–Weiss law and a weak ferromagnetic behavior observed at room temperature in the M vs H curves can be attributed to the strong magnetic interactions between the transition metals with different oxidation states. - Highlights: • YFe 1−x Cr x O 3 (0≤x≤1) samples were synthesized by co-precipitation method. • XRD dates showed a reduction of unit cell volume with addition of Cr. • XANES dates showed difference in the oxidation states to Cr and Fe. • MZFC-MFC indicate a decreasing of the T N as function of chromium doping. • MFC curve for x=0.5 concentration was observed the reverse magnetization effect.

  20. State of dog's metabolism in the remote period after the oxide tritium influence

    International Nuclear Information System (INIS)

    Kalistratova, V.S.; Tishchenko, G.S.; Bortnik, L.A.; Nisimov, P.G.; Romanova, I.B.

    2000-01-01

    Influence of tritium oxide on the metabolism by some indices of lipid metabolism (common lipids, β-lipoproteins, cholesterin), protein metabolism (cholinesterase) and carbohydrate metabolism (blood sugar) was studied. It was established that the introduction into organism of tritium oxide in the quantities, which could form lethal and sublethal doses of internal radiation, provoked the main changes of values of mentioned indices of metabolism. The character of metabolism changes in the remote period allows to judge about the development of sclerosis processes which can be the result of radiation-stipulated acceleration of organism aging [ru

  1. Oxidative stress

    Directory of Open Access Journals (Sweden)

    Osredkar Joško

    2012-05-01

    Full Text Available The human organism is exposed to the influence of various forms of stress, either physical, psychological or chemical, which all have in common that they may adversely affect our body. A certain amount of stress is always present and somehow directs, promotes or inhibits the functioning of the human body. Unfortunately, we are now too many and too often exposed to excessive stress, which certainly has adverse consequences. This is especially true for a particular type of stress, called oxidative stress. All aerobic organisms are exposed to this type of stress because they produce energy by using oxygen. For this type of stress you could say that it is rather imperceptibly involved in our lives, as it becomes apparent only at the outbreak of certain diseases. Today we are well aware of the adverse impact of radicals, whose surplus is the main cause of oxidative stress. However, the key problem remains the detection of oxidative stress, which would allow us to undertake timely action and prevent outbreak of many diseases of our time. There are many factors that promote oxidative stress, among them are certainly a fast lifestyle and environmental pollution. The increase in oxidative stress can also trigger intense physical activity that is directly associated with an increased oxygen consumption and the resulting formation of free radicals. Considering generally positive attitude to physical activity, this fact may seem at first glance contradictory, but the finding has been confimed by several studies in active athletes. Training of a top athlete daily demands great physical effort, which is also reflected in the oxidative state of the organism. However, it should be noted that the top athletes in comparison with normal individuals have a different defense system, which can counteract the negative effects of oxidative stress. Quite the opposite is true for irregular or excessive physical activity to which the body is not adapted.

  2. Numerical Research of Nitrogen Oxides Formation for Justification of Modernization of P-49 Nazarovsky State District Power Plant Boiler on the Low-temperature Swirl Technology of Burning

    Science.gov (United States)

    Trinchenko, A. A.; Paramonov, A. P.; Skouditskiy, V. E.; Anoshin, R. G.

    2017-11-01

    Compliance with increasingly stringent normative requirements to the level of pollutants emissions when using organic fuel in the energy sector as a main source of heat, demands constant improvement of the boiler and furnace equipment and the power equipment in general. The requirements of the current legislation in the field of environmental protection prescribe compliance with established emission standards for both new construction and the improvement of energy equipment. The paper presents the results of numerical research of low-temperature swirl burning in P-49 Nazarovsky state district power plant boiler. On the basis of modern approaches of the diffusion and kinetic theory of burning and the analysis physical and chemical processes of a fuel chemically connected energy transition in thermal, generation and transformation of gas pollutants, the technological method of nitrogen oxides decomposition on the surface of carbon particles with the formation of environmentally friendly carbonic acid and molecular nitrogen is considered during the work of low-temperature swirl furnace. With the use of the developed model, methodology and computer program, variant calculations of the combustion process were carried out and a quantitative estimate of the emission level of the nitrogen oxides of the boiler being modernized. The simulation results the and the experimental data obtained during the commissioning and balance tests of the P-49 boiler with a new furnace are confirmed that the organization of swirl combustion has allowed to increase the efficiency of work, to reduce slagging, to significantly reduce nitrogen oxide emissions, to improve ignition and burnout of fuel.

  3. The state-of-the-art and prospects of the oxidation titration method for the determination of uranium in geological samples

    International Nuclear Information System (INIS)

    Sun Jiayan

    1986-01-01

    The state-of-the-art of the oxidation titration method for the determination of uranium in geological samples is reviewed in some respects such as the prereduction of U(VI), oxidation of U(IV) and the detection of the end-point. Comments are also made on the prospects of further improvements of this method

  4. Remote mixed oxide fabrication facility development. Volume 2. State-of-the-art review of remote maintenance system technology

    International Nuclear Information System (INIS)

    Horgos, R.M.; Masch, M.L.

    1979-06-01

    This report provides a state-of-the-art review of remote systems technology, which includes manipulators, process connectors, vision systems and specialized process systems. A proposed mixed oxide fuel fabrication facility was reviewed and evaluated for identification of major remote maintenance and repair tasks. The technological areas were evaluated on the basis of their suitability or applicability for remote maintenance and repair of a proposed fully remote operating mixed oxide fuel fabrication facility. A technological base exists from which the design criteria for a reliable, remote operating facility can be established. Commercially available systems and components, along with those remote technologies now in development, will require modifications to adapt them to specific plant designs and requirements

  5. Electrochemistry and time dependent DFT study of a (vinylenedithio)-TTF derivative in different oxidation states

    NARCIS (Netherlands)

    Halpin, Yvonne; Schulz, Martin; Brooks, Andrew C.; Browne, Wesley R.; Wallis, John D.; Gonzalez, Leticia; Day, Peter; Vos, Johannes G.

    2013-01-01

    The electrochemical and spectroelectrochemical properties of a bis-pyrid-4-yl functionalised vinylenedithio-TFF derivative, 1, in solution are reported. The compound was immobilised on a Pt electrode and the resulting layers formed were investigated using electrochemical techniques. Two oxidation

  6. Influence of Structure and Charge State on the Mechanism of CO Oxidation on Gold Clusters

    Science.gov (United States)

    Johnson, Grant; Burgel, Christian; Reilly, Nelly; Mitric, Roland; Kimble, Michele; Tyo, Eric; Castleman, A. W.; Bonacic-Koutecky, Vlasta

    2008-05-01

    Gas-phase reactivity experiments and high level theoretical calculations have been employed to study the interaction of both positively and negatively charged gold oxide clusters with carbon monoxide (CO). We demonstrate that for negatively charged clusters CO is oxidized to CO2 by an Eley-Ridel-like (ER-) mechanism involving the attack of CO on oxygen rather than gold. In contrast, for positively charged clusters, the oxidation reaction may also occur by a Langmuir-Hinshelwood-like (LH-) mechanism involving the initial binding of CO to a gold atom followed by subsequent migration to an oxygen site. The LH mechanism is made possible through the large energy gain associated with the adsorption of two CO molecules onto cationic gold clusters. Structure-reactivity relationships are also established which demonstrate that terminally bound oxygen atoms are the most active sites for CO oxidation. Bridge bonded oxygen atoms and molecularly bound O2 units are shown to be inert. We also establish an inverse relationship between the binding energy of CO to gold clusters and the energy of the clusters lowest unoccupied molecular orbital (LUMO).

  7. Theory of novel normal and superconducting states in doped oxide high-Tc superconductors

    International Nuclear Information System (INIS)

    Dzhumanov, S.

    2001-10-01

    the observed second- and first-order SC phase transitions in HTSC. We examine the relationship between the pairing pseudogap Δ F and the SC gap Δ B and their doping dependences. We argue that two distinct FBL scenarios of novel superconductivity are realized in so-called fermion superconductors (overdoped HTSC) and boson ones (underdoped and optimally doped HTSC). The formation of the stripe phases in underdoped HTSC is discussed within the large (bi)polaron model and the novel FBL model. It is shown that the novel normal and SC state properties of doped HTSC have not only 2d but also essentially 3d character. The generic and relevant electronic phase diagrams of doped HTSC are presented. The novel theory consistently and successfully explains existing experimental data. (author)

  8. A study of relaxation mechanisms in the A{sup 2}{Sigma}{sup +} state of nitric oxide by time resolved double resonant polarization spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stampanoni-Panariello, A; Bombach, R; Hemmerling, B; Hubschmid, W [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Double resonant polarization labeling spectroscopy is applied to detect nitric oxide in flames and to characterize rotational energy transfer and orientation changing collisions in its first excited electronic state. (author) 4 figs., 3 refs.

  9. Neck injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and American football

    OpenAIRE

    Delaney, J; Al-Kashmiri, A

    2005-01-01

    Objective: To examine the number and rate of neck injuries in the community as a whole for ice hockey, soccer, and American football by analysing data from patients presenting to emergency departments in the United States from 1990 to 1999.

  10. A detailed study on the transition from the blocked to the superparamagnetic state of reduction-precipitated iron oxide nanoparticles

    International Nuclear Information System (INIS)

    Witte, K.; Bodnar, W.; Mix, T.; Schell, N.; Fulda, G.; Woodcock, T.G.; Burkel, E.

    2016-01-01

    Magnetic iron oxide nanoparticles were prepared by salt-assisted solid-state chemical precipitation method with alternating fractions of the ferric iron content. The physical properties of the precipitated nanoparticles mainly consisting of magnetite were investigated by means of transmission electron microscopy, high energy X-ray diffraction, vibrating sample magnetometry and Mössbauer spectroscopy. With particle sizes ranging from 16.3 nm to 2.1 nm, a gradual transition from the blocked state to the superparamagnetic state was observed. The transition was described as a dependence of the ferric iron content used during the precipitation. Composition, mean particle size, coercivity, saturation polarisation, as well as hyperfine interaction parameters and their evolution were studied systematically over the whole series of iron oxide nanoparticles. - Highlights: • Study of superparamagnetic transition of magnetite varying ferric iron content. • Coercivity is mainly influenced by the particle size. • Saturation polarisation influenced by the goethite content and the particle size. • Number of vacancies tend to increase with increasing ferric iron content. • Fe 3 O 4 B-sites are stronger effected by the reduction of particle size than A-sites.

  11. All-solid-state flexible microsupercapacitors based on reduced graphene oxide/multi-walled carbon nanotube composite electrodes

    Science.gov (United States)

    Mao, Xiling; Xu, Jianhua; He, Xin; Yang, Wenyao; Yang, Yajie; Xu, Lu; Zhao, Yuetao; Zhou, Yujiu

    2018-03-01

    All-solid-state flexible microsupercapacitors have been intensely investigated in order to meet the rapidly growing demands for portable microelectronic devices. Herein, we demonstrate a facile, readily scalable and cost-effective laser induction process for preparing reduced graphene oxide/multi-walled carbon nanotube composite, which can be used as the interdigital electrodes in microsupercapacitors. The obtained composite exhibits high volumetric capacitance about 49.35 F cm-3, which is nearly 5 times higher than that of the pristine reduced graphene oxide film in aqueous 1.0 M H2SO4 solution (measured at a current density of 5 A cm-3 in a three-electrode testing). Additionally, an all-solid-state flexible microsupercapacitor employing these composite electrodes with PVA/H3PO4 gel electrolyte delivers high volumetric energy density of 6.47 mWh cm-3 at 10 mW cm-3 under the current density of 20 mA cm-3 as well as achieve excellent cycling stability retaining 88.6% of its initial value and outstanding coulombic efficiency after 10,000 cycles. Furthermore, the microsupercapacitors array connected in series/parallel can be easily adjusted to achieve the demands in practical applications. Therefore, this work brings a promising new candidate of prepare technologies for all-solid-state flexible microsupercapacitors as miniaturized power sources used in the portable and wearable electronics.

  12. Effect of charged deep states in hydrogenated amorphous silicon on the behavior of iron oxides nanoparticles deposited on its surface

    International Nuclear Information System (INIS)

    Gmucova, Katarina; Weis, Martin; Nadazdy, Vojtech; Capek, Ignac; Satka, Alexander; Chitu, Livia; Cirak, Julius; Majkova, Eva

    2008-01-01

    Langmuir-Blodgett technique has been used for the deposition of ordered two-dimensional arrays of iron oxides (Fe 3 O 4 /Fe 2 O 3 ) nanoparticles onto the photovoltaic hydrogenated amorphous silicon (a-Si:H) thin film. Electric field at the a-Si:H/iron oxides nanoparticles interface was directly in the electrochemical cell modified by light soaking and bias voltage (negative or positive) pretreatment resulting in the change of the dominant type of charged deep states in the a-Si:H layer. Induced reversible changes in the nanoparticle redox behavior have been observed. We suggest two possible explanations of the data obtained, both of them are needed to describe measured electrochemical signals. The first one consists in the electrocatalytical effect caused by the defect states (negatively or positively charged) in the a-Si:H layer. The second one consists in the possibility to manipulate the nanoparticle cores in the prepared structure immersed in aqueous solution via the laser irradiation under specific bias voltage. In this case, the nanoparticle cores are assumed to be covered with surface clusters of heterovalent complexes created onto the surface regions with prevailing ferrous or ferric valency. Immersed in the high viscosity surrounding composed of the wet organic nanoparticle envelope these cores are able to perform a field-assisted pivotal motion. The local electric field induced by the deep states in the a-Si:H layer stabilizes their 'orientation ordering' in an energetically favourable position

  13. Hemoglobin redux: combining neutron and X-ray diffraction with mass spectrometry to analyse the quaternary state of oxidized hemoglobins

    Energy Technology Data Exchange (ETDEWEB)

    Mueser, Timothy C., E-mail: timothy.mueser@utoledo.edu; Griffith, Wendell P. [Department of Chemistry, University of Toledo, Toledo, OH 43606 (United States); Kovalevsky, Andrey Y. [Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Guo, Jingshu; Seaver, Sean [Department of Chemistry, University of Toledo, Toledo, OH 43606 (United States); Langan, Paul [Department of Chemistry, University of Toledo, Toledo, OH 43606 (United States); Bioscience Division, MS M888, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hanson, B. Leif [Department of Chemistry, University of Toledo, Toledo, OH 43606 (United States)

    2010-11-01

    X-ray and neutron diffraction studies of cyanomethemoglobin are being used to evaluate the structural waters within the dimer–dimer interface involved in quaternary-state transitions. Improvements in neutron diffraction instrumentation are affording the opportunity to re-examine the structures of vertebrate hemoglobins and to interrogate proton and solvent position changes between the different quaternary states of the protein. For hemoglobins of unknown primary sequence, structural studies of cyanomethemoglobin (CNmetHb) are being used to help to resolve sequence ambiguity in the mass spectra. These studies have also provided additional structural evidence for the involvement of oxidized hemoglobin in the process of erythrocyte senescence. X-ray crystal studies of Tibetan snow leopard CNmetHb have shown that this protein crystallizes in the B state, a structure with a more open dyad, which possibly has relevance to RBC band 3 protein binding and erythrocyte senescence. R-state equine CNmetHb crystal studies elaborate the solvent differences in the switch and hinge region compared with a human deoxyhemoglobin T-state neutron structure. Lastly, comparison of histidine protonation between the T and R state should enumerate the Bohr-effect protons.

  14. Wide-area mapping of resting state hemodynamic correlations at microvascular resolution with multi-contrast optical imaging (Conference Presentation)

    Science.gov (United States)

    Senarathna, Janaka; Hadjiabadi, Darian; Gil, Stacy; Thakor, Nitish V.; Pathak, Arvind P.

    2017-02-01

    Different brain regions exhibit complex information processing even at rest. Therefore, assessing temporal correlations between regions permits task-free visualization of their `resting state connectivity'. Although functional MRI (fMRI) is widely used for mapping resting state connectivity in the human brain, it is not well suited for `microvascular scale' imaging in rodents because of its limited spatial resolution. Moreover, co-registered cerebral blood flow (CBF) and total hemoglobin (HbT) data are often unavailable in conventional fMRI experiments. Therefore, we built a customized system that combines laser speckle contrast imaging (LSCI), intrinsic optical signal (IOS) imaging and fluorescence imaging (FI) to generate multi-contrast functional connectivity maps at a spatial resolution of 10 μm. This system comprised of three illumination sources: a 632 nm HeNe laser (for LSCI), a 570 nm ± 5 nm filtered white light source (for IOS), and a 473 nm blue laser (for FI), as well as a sensitive CCD camera operating at 10 frames per second for image acquisition. The acquired data enabled visualization of changes in resting state neurophysiology at microvascular spatial scales. Moreover, concurrent mapping of CBF and HbT-based temporal correlations enabled in vivo mapping of how resting brain regions were linked in terms of their hemodynamics. Additionally, we complemented this approach by exploiting the transit times of a fluorescent tracer (Dextran-FITC) to distinguish arterial from venous perfusion. Overall, we demonstrated the feasibility of wide area mapping of resting state connectivity at microvascular resolution and created a new toolbox for interrogating neurovascular function.

  15. Reversal magnetization dependence with the Cr and Fe oxidation states in YFe1-xCrxO3 (0≤x≤1) perovskites

    Science.gov (United States)

    Fabian, F. A.; Pedra, P. P.; Moura, K. O.; Duque, J. G. S.; Meneses, C. T.

    2016-06-01

    In this work, we have carried out a detailed study of the magnetic and structural properties of YFe1-xCrxO3 (0≤x≤1) samples with orthorhombic structure obtained by co-precipitation method. Analysis of X-ray diffraction data using Rietveld refinement show that all samples present an orthorhombic crystal system with space group Pnma. Besides, we have observed a reduction of unit cell volume with increasing of the Cr concentration. SEM images show the formation of grains of micrometer order. X-ray Absorption near edge spectroscopy (XANES) measurements show a shift of absorption edge which can be indicate there is (i) different oxidation states to Fe and Cr ions and/or (ii) a changing in the point symmetry of Fe and Cr ions to the compounds. The magnetization measurements indicate a continuous decreasing of the magnetic transition temperature as function of chromium doping. The reversal magnetization effect was observed to concentrations around x=0.5. Besides, the deviation of the Curie-Weiss law and a weak ferromagnetic behavior observed at room temperature in the M vs H curves can be attributed to the strong magnetic interactions between the transition metals with different oxidation states.

  16. Nitric oxide in plants: an assessment of the current state of knowledge

    DEFF Research Database (Denmark)

    Mur, Luis A J; Mandon, Julien; Persijn, Stefan

    2013-01-01

    Background and aims After a series of seminal works during the last decade of the 20th century nitric oxide (NO) is now firmly placed in the pantheon of plant signals. NO acts in plant-microbe interactions, responses to abiotic stress, stomatal regulation and a range of developmental processes...... of NO production from DEANO (diethylamine nitric oxide), S-nitrosoglutathione (GSNO) and sodium nitroprusside (SNP) following infiltration of tobacco leaves which could aid workers in their experiments. Further, based on current data it is difficult to define a bespoke plant NO signalling pathway, but rather....... By considering the recent advances in plant NO biology, this review will highlight certain key aspects that require further attention. Scope and conclusions The following questions will be considered. Whilst cytosolic nitrate reductase is an important source of NO, the contributions of other mechanisms...

  17. The discrimination of the oxidation states of neptunium in sodium hydroxide solutions by means of chromatography on alumina

    International Nuclear Information System (INIS)

    Shiokawa, Yoshinobu; Yamana, Hajimu; Sato, Akiko; Suzuki, Shin

    1982-01-01

    A method of discriminating the oxidation states of Np in a NaOH solution by means of chromatography on alumina is proposed. In a NaOH solution of 0.5 - 1.7 M (1 M = 1 mol dm - 3 ), the separation of Np (VI) from Np (VII) can be made effectively by means of chromatography on alumina. Only a little Np (VI) is adsorbed on alumina the Np (VII) adsorbed to some extent, and the Np (V), strongly, under the same conditions. By applying this chromatographic method, the method of preparing Np (VI) and Np (VII) of a tracer quantity in 1 M NaOH is established. (author)

  18. Proof-of-principle test of coherent-state continuous variable quantum key distribution through turbulent atmosphere (Conference Presentation)

    Science.gov (United States)

    Derkach, Ivan D.; Peuntinger, Christian; Ruppert, László; Heim, Bettina; Gunthner, Kevin; Usenko, Vladyslav C.; Elser, Dominique; Marquardt, Christoph; Filip, Radim; Leuchs, Gerd

    2016-10-01

    Continuous-variable quantum key distribution is a practical application of quantum information theory that is aimed at generation of secret cryptographic key between two remote trusted parties and that uses multi-photon quantum states as carriers of key bits. Remote parties share the secret key via a quantum channel, that presumably is under control of of an eavesdropper, and which properties must be taken into account in the security analysis. Well-studied fiber-optical quantum channels commonly possess stable transmittance and low noise levels, while free-space channels represent a simpler, less demanding and more flexible alternative, but suffer from atmospheric effects such as turbulence that in particular causes a non-uniform transmittance distribution referred to as fading. Nonetheless free-space channels, providing an unobstructed line-of-sight, are more apt for short, mid-range and potentially long-range (using satellites) communication and will play an important role in the future development and implementation of QKD networks. It was previously theoretically shown that coherent-state CV QKD should be in principle possible to implement over a free-space fading channel, but strong transmittance fluctuations result in the significant modulation-dependent channel excess noise. In this regime the post-selection of highly transmitting sub-channels may be needed, which can even restore the security of the protocol in the strongly turbulent channels. We now report the first proof-of-principle experimental test of coherent state CV QKD protocol using different levels Gaussian modulation over a mid-range (1.6-kilometer long) free-space atmospheric quantum channel. The transmittance of the link was characterized using intensity measurements for the reference but channel estimation using the modulated coherent states was also studied. We consider security against Gaussian collective attacks, that were shown to be optimal against CV QKD protocols . We assumed a

  19. Catalytic oxidation using nitrous oxide

    Directory of Open Access Journals (Sweden)

    Juan Carlos Beltran-Prieto

    2017-01-01

    Full Text Available Nitrous oxide is a very inert gas used generally as oxidant as it offers some advantage compared with other oxidants such as O2 but a considerably higher temperature (> 526 °C is often required. For particular cases such as the oxidation of sugar alcohols, especially for the oxidation of primary alcohols to aldehydes, N2O has the advantage over O2 of a higher reaction selectivity. In the present paper we present the modelling of oxidation reaction of sugar alcohols using an oxidizing agent in low concentrations, which is important to suppress subsequent oxidation reactions due to the very low residual concentrations of the oxidizing agent. For orientation experiments we chose nitrous oxide generated by thermal decomposition of ammonium nitrate. Kinetic modeling of the reaction was performed after determination of the differential equations that describe the system under study.

  20. Solid-state Water-mediated Transport Reduction of Nanostructured Iron Oxides

    International Nuclear Information System (INIS)

    Smirnov, Vladimir M.; Povarov, Vladimir G.; Voronkov, Gennadii P.; Semenov, Valentin G.; Murin, Igor' V.; Gittsovich, Viktor N.; Sinel'nikov, Boris M.

    2001-01-01

    The Fe 2+ /Fe 3+ ratio in two-dimensional iron oxide nanosructures (nanolayers with a thickness of 0.3-1.5 nm on silica surface) may be precisely controlled using the transport reduction (TR) technique. The species ≡-O-Fe(OH) 2 and (≡Si-O-) 2 -FeOH forming the surface monolayer are not reduced at 400-600 deg. C because of their covalent bonding to the silica surface, as demonstrated by Moessbauer spectroscopy. Iron oxide microparticles (microstructures) obtained by the impregnation technique, being chemically unbound to silica, are subjected to reduction at T ≥ 500 deg. C with formation of metallic iron in the form of α-Fe. Transport reduction of supported nanostructures (consisting of 1 or 4 monolayers) at T ≥ 600 deg. C produces bulk iron(II) silicate and metallic iron phases. The structural-chemical transformations occurring in transport reduction of supported iron oxide nanolayers are proved to be governed by specific phase processes in the nanostructures themselves

  1. Constitutively elevated salicylic acid levels alter photosynthesis and oxidative state but not growth in transgenic populus.

    Science.gov (United States)

    Xue, Liang-Jiao; Guo, Wenbing; Yuan, Yinan; Anino, Edward O; Nyamdari, Batbayar; Wilson, Mark C; Frost, Christopher J; Chen, Han-Yi; Babst, Benjamin A; Harding, Scott A; Tsai, Chung-Jui

    2013-07-01

    Salicylic acid (SA) has long been implicated in plant responses to oxidative stress. SA overproduction in Arabidopsis thaliana leads to dwarfism, making in planta assessment of SA effects difficult in this model system. We report that transgenic Populus tremula × alba expressing a bacterial SA synthase hyperaccumulated SA and SA conjugates without negative growth consequences. In the absence of stress, endogenously elevated SA elicited widespread metabolic and transcriptional changes that resembled those of wild-type plants exposed to oxidative stress-promoting heat treatments. Potential signaling and oxidative stress markers azelaic and gluconic acids as well as antioxidant chlorogenic acids were strongly coregulated with SA, while soluble sugars and other phenylpropanoids were inversely correlated. Photosynthetic responses to heat were attenuated in SA-overproducing plants. Network analysis identified potential drivers of SA-mediated transcriptome rewiring, including receptor-like kinases and WRKY transcription factors. Orthologs of Arabidopsis SA signaling components NON-EXPRESSOR OF PATHOGENESIS-RELATED GENES1 and thioredoxins were not represented. However, all members of the expanded Populus nucleoredoxin-1 family exhibited increased expression and increased network connectivity in SA-overproducing Populus, suggesting a previously undescribed role in SA-mediated redox regulation. The SA response in Populus involved a reprogramming of carbon uptake and partitioning during stress that is compatible with constitutive chemical defense and sustained growth, contrasting with the SA response in Arabidopsis, which is transient and compromises growth if sustained.

  2. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn

    International Nuclear Information System (INIS)

    Biesinger, Mark C.; Lau, Leo W.M.; Gerson, Andrea R.; Smart, Roger St.C.

    2010-01-01

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of the 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. A review of current literature shows that all values necessary for reproducible, quantitative chemical state analysis are usually not provided. This paper reports a more consistent, practical and effective approach to curve-fitting the various chemical states in a variety of Sc, Ti, V, Cu and Zn metals, oxides and hydroxides. The curve-fitting procedures proposed are based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of the literature references, and (3) specific literature references where fitting procedures are available. Binding energies, full-width at half maximum (FWHM) values, spin-orbit splitting values, asymmetric peak-shape fitting parameters, and, for Cu and Zn, Auger parameters values are presented. The quantification procedure for Cu species details the use of the shake-up satellites for Cu(II)-containing compounds and the exact binding energies of the Cu(0) and Cu(I) peaks. The use of the modified Auger parameter for Cu and Zn species allows for corroborating evidence when there is uncertainty in the binding energy assignment. These procedures can remove uncertainties in analysis of surface states in nano-particles, corrosion, catalysis and surface-engineered materials.

  3. Resolving surface chemical states in XPS analysis of first row transition metals, oxides and hydroxides: Sc, Ti, V, Cu and Zn

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, Mark C., E-mail: biesingr@uwo.ca [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia); Lau, Leo W.M. [Surface Science Western, University of Western Ontario, University of Western Ontario Research Park, Room LL31, 999 Collip Circle, London, Ontario, N6G 0J3 (Canada); Department of Chemistry, University of Western Ontario, London, Ontario, N6A 5B7 (Canada); Gerson, Andrea R.; Smart, Roger St.C. [ACeSSS (Applied Centre for Structural and Synchrotron Studies), University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2010-11-15

    Chemical state X-ray photoelectron spectroscopic analysis of first row transition metals and their oxides and hydroxides is challenging due to the complexity of the 2p spectra resulting from peak asymmetries, complex multiplet splitting, shake-up and plasmon loss structure, and uncertain, overlapping binding energies. A review of current literature shows that all values necessary for reproducible, quantitative chemical state analysis are usually not provided. This paper reports a more consistent, practical and effective approach to curve-fitting the various chemical states in a variety of Sc, Ti, V, Cu and Zn metals, oxides and hydroxides. The curve-fitting procedures proposed are based on a combination of (1) standard spectra from quality reference samples, (2) a survey of appropriate literature databases and/or a compilation of the literature references, and (3) specific literature references where fitting procedures are available. Binding energies, full-width at half maximum (FWHM) values, spin-orbit splitting values, asymmetric peak-shape fitting parameters, and, for Cu and Zn, Auger parameters values are presented. The quantification procedure for Cu species details the use of the shake-up satellites for Cu(II)-containing compounds and the exact binding energies of the Cu(0) and Cu(I) peaks. The use of the modified Auger parameter for Cu and Zn species allows for corroborating evidence when there is uncertainty in the binding energy assignment. These procedures can remove uncertainties in analysis of surface states in nano-particles, corrosion, catalysis and surface-engineered materials.

  4. Annual report on the environmental radiation monitoring around Tokai Reprocessing Plant. FY 2001. Document on present state of affairs

    International Nuclear Information System (INIS)

    Shinohara, Kunihiko; Takeishi, Minoru; Miyagawa, Naoto

    2002-06-01

    Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed since 1975, based on ''Safety Regulations for the Tokai Reprocessing Plant, Chapter IV - Environmental Monitoring''. This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant during April 2001 to March 2002. Appendices present comprehensive information, such as monitoring program, monitoring results, meteorological data and annual discharges from the plant. (author)

  5. Vacuum-Assisted Low-Temperature Synthesis of Reduced Graphene Oxide Thin-Film Electrodes for High-Performance Transparent and Flexible All-Solid-State Supercapacitors.

    Science.gov (United States)

    Aytug, Tolga; Rager, Matthew S; Higgins, Wesley; Brown, Forrest G; Veith, Gabriel M; Rouleau, Christopher M; Wang, Hui; Hood, Zachary D; Mahurin, Shannon M; Mayes, Richard T; Joshi, Pooran C; Kuruganti, Teja

    2018-04-04

    Simple and easily integrated design of flexible and transparent electrode materials affixed to polymer-based substrates hold great promise to have a revolutionary impact on the functionality and performance of energy storage devices for many future consumer electronics. Among these applications are touch sensors, roll-up displays, photovoltaic cells, health monitors, wireless sensors, and wearable communication devices. Here, we report an environmentally friendly, simple, and versatile approach to produce optically transparent and mechanically flexible all-solid-state supercapacitor devices. These supercapacitors were constructed on tin-doped indium oxide coated polyethylene terephthalate substrates by intercalation of a polymer-based gel electrolyte between two reduced graphene oxide (rGO) thin-film electrodes. The rGO electrodes were fabricated simply by drop-casting of graphene oxide (GO) films, followed by a novel low-temperature (≤250 °C) vacuum-assisted annealing approach for the in situ reduction of GO to rGO. A trade-off between the optical transparency and electrochemical performance is determined by the concentration of the GO in the initial dispersion, whereby the highest capacitance (∼650 μF cm -2 ) occurs at a relatively lower optical transmittance (24%). Notably, the all-solid-state supercapacitors demonstrated excellent mechanical flexibility with a capacity retention rate above 90% under various bending angles and cycles. These attributes underscore the potential of the present approach to provide a path toward the realization of thin-film-based supercapacitors as flexible and transparent energy storage devices for a variety of practical applications.

  6. The clinical manifestations of HIV infections in adults presenting to Khartoum state and the incidence of pulmonary tuberculosis among them

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Amir Abd Elraouf [Faculty of Medicine, University of Khartoum, Khartoum (Sudan)

    1998-10-01

    This is a prospective study of 60 patients with HIV infection admitted to medical wards at Khartoum Teaching Hospital, Omdurman Teaching Hospital, Tropical Diseases' Hospital in Omdurman, Chest Teaching Hospital in Khartoum State during the period June 1997 to June 1998, to study the clinical manifestations of HIV, the possible mode of transmission and the incidence of tuberculosis among them. The population of the study were those with HIV infection of both sexes above 15 years of age. Data was collected using a questionnaire detailing the medical history, through medical examination and laboratory investigations.

  7. The clinical manifestations of HIV infections in adults presenting to Khartoum state and the incidence of pulmonary tuberculosis among them

    International Nuclear Information System (INIS)

    Ahmed, Amir Abd Elraouf

    1998-10-01

    This is a prospective study of 60 patients with HIV infection admitted to medical wards at Khartoum Teaching Hospital, Omdurman Teaching Hospital, Tropical Diseases' Hospital in Omdurman, Chest Teaching Hospital in Khartoum State during the period June 1997 to June 1998, to study the clinical manifestations of HIV, the possible mode of transmission and the incidence of tuberculosis among them. The population of the study were those with HIV infection of both sexes above 15 years of age. Data was collected using a questionnaire detailing the medical history, through medical examination and laboratory investigations

  8. Analyzer for measurement of nitrogen oxide concentration by ozone content reduction in gas using solid state chemiluminescent sensor

    Science.gov (United States)

    Chelibanov, V. P.; Ishanin, G. G.; Isaev, L. N.

    2014-05-01

    Role of nitrogen oxide in ambient air is described and analyzed. New method of nitrogen oxide concentration measurement in gas phase is suggested based on ozone concentration measurement with titration by nitrogen oxide. Research of chemiluminescent sensor composition is carried out on experimental stand. The sensor produced on the base of solid state non-activated chemiluminescent composition is applied as ozone sensor. Composition is put on the surface of polymer matrix with developed surface. Sensor compositions includes gallic acid with addition of rodamine-6G. Model of interaction process between sensor composition and ozone has been developed, main products appeared during reaction are identified. The product determining the speed of luminescense appearance is found. This product belongs to quinone class. Then new structure of chemiluminescent composition was suggested, with absence of activation period and with high stability of operation. Experimental model of gas analyzer was constructed and operation algorithm was developed. It was demonstrated that developed NO measuring instrument would be applied for monitoring purposes of ambient air. This work was partially financially supported by Government of Russian Federation, Grant 074-U01

  9. An Analysis of Future Publications, Career Choices, and Practice Characteristics of Research Presenters at an American College of Surgeons State Conference: A 15-Year Review.

    Science.gov (United States)

    Ahmad, Humera F; Jarman, Benjamin T; Kallies, Kara J; Shapiro, Stephen B

    The Accreditation Council for Graduate Medical Education requires scholarly activity within general surgery residency programs. The association between in-training research presentations and postgraduation publications is unknown. We hypothesized that surgical trainee presentations at an American College of Surgeons (ACS) state chapter meeting resulted in peer-reviewed publications and future scholarly activity. The ACS Wisconsin state chapter meeting agendas from 2000 to 2014 were reviewed to identify all trainees who delivered podium presentations. A literature search was completed for subsequent publications. Program coordinators were queried and an electronic search was performed to determine practice location and type for each residency graduate. Wisconsin state chapter ACS meeting. General surgery residents, fellows, and medical students in Wisconsin. There were 288 podium presentations by trainees (76% residents, 20% medical students, and 4% fellows). Presentations were clinical (79.5%) and basic science (20.5%). There were 204 unique presenters; 25% presented at subsequent meetings. Of these unique presenters, 46% published their research and 31% published additional research after residency. Among presenters who completed residency or fellowship (N = 119), 34% practiced in a university setting, and 61% practiced in a community setting; 31% practiced in Wisconsin. When comparing clinical vs basic science presenters, there was no difference in fellowship completion (37% vs 44%; p = 0.190) or practice type (38% vs 46% in a university setting; p = 0.397). Repeat presenters were more likely to pursue a fellowship vs those presenting once (76% vs 37%; p = 0.001). Research presentations by surgical trainees at an ACS state chapter meeting frequently led to peer-reviewed publications. Presenters were likely to pursue research opportunities after residency. Repeat presenters were more likely to pursue a fellowship. ACS Wisconsin chapter meetings provide an

  10. A review of the present state and future policy alternatives for home visit nursing services in Korea.

    Science.gov (United States)

    Lim, Ji Young; Noh, Wonjung; Kim, Eunjoo; Choi, Kyung Won

    2014-01-01

    The aim of this study was to describe the current state of home visit nursing services in the Korean context and to suggest future policy directions. First, the three home visit nursing services that have developed in Korea are compared using the analytic framework provided by Gilbert and Terrell in 2012. The framework is based on four dimensions of social welfare: users, services, source of funds, and service delivery process. Second, we perform a strength, weakness, opportunity, and threat analysis to suggest comprehensive and constructive home visit nursing service policies for the future. Specifically, we advocate the creation of an organization that steers the central government to operate an integrated management organization to distribute services and reduce redundancy for preventing the waste of both medical and state financial resources. This study also recommends the development of educational programs to improve the quality of services and service evaluation criteria for the objective assessment of those services. These policy guidelines may prove useful both for Korea and for other countries that intend to prepare or revise their home visit nursing service systems. © 2014 Wiley Periodicals, Inc.

  11. The Oxides of Nitrogen in Air Pollution.

    Science.gov (United States)

    California State Air Resources Board, Sacramento.

    Research on the health effects of oxides of nitrogen and on the role of oxides of nitrogen in producing photochemical smog effects is presented in this report. Prepared by the California State Department of Public Health at the request of the State Legislature, it gives a comprehensive review of available information, as well as the need for air…

  12. Oxidation states by X-ray fluorescence and electron probe microanalysis techniques

    International Nuclear Information System (INIS)

    Vazquez, Cristina; Riveros, J.A.

    1987-01-01

    Many years ago, several studies showed the effect of a chemical state in X-ray spectra. The effect, however, has rarely been utilized in quantitative chemical analysis. The purpose of this work is to show observed shifts due to different chemical states in iron compounds. (Author) [es

  13. Presentation of a novel model of chitosan- polyethylene oxide-nanohydroxyapatite nanofibers together with bone marrow stromal cells to repair and improve minor bone defects

    Directory of Open Access Journals (Sweden)

    Asgar Emamgholi

    2015-09-01

    Full Text Available Objective(s:Various methods for repairing bone defects are presented. Cell therapy is one of these methods. Bone marrow stromal cells (BMSCs seem to be suitable for this purpose. On the other hand, lots of biomaterials are used to improve and repair the defect in the body, so in this study we tried to produce a similar structure to the bone by the chitosan and hydroxyapatite. Materials and Methods: In this study, the solution of chitosan-nanohydroxyapatite-polyethylene oxide (PEO Nanofibers was produced by electrospinning method, and then the BMSCs were cultured on this solution. A piece of chitosan-nanohydroxyapatite Nanofibers with BMSCs was placed in a hole with the diameter of 1 mm at the distal epiphysis of the rat femur. Then the biomechanical and radiographic studies were performed. Results: Biomechanical testing results showed that bone strength was significantly higher in the Nanofiber/BMSCs group in comparison with control group. Also the bone strength in nanofiber/BMSCs group was significant, but in nanofiber group was nearly significant. Radiographic studies also showed that the average amount of callus formation (radio opacity in nanofiber and control group was not significantly different. The callus formation in nanofiber/BMSCs group was increased compared to the control group, and it was not significant in the nanofiber group. Conclusion: Since chitosan-nanohydroxyapatite nanofibers with BMSCs increases the rate of bone repair, the obtained cell-nanoscaffold shell can be used in tissue engineering and cell therapy, especially for bone defects.

  14. Diagnostic and therapeutic hardships with mixed affective state presenting as catatonia in a patient with intellectual disability

    Directory of Open Access Journals (Sweden)

    Karthick Subramanian

    2017-01-01

    Full Text Available Mixed affective episodes can be misdiagnosed, especially in patients with intellectual disability (ID. We describe the case of an 18-year-old girl with mild ID, who presented with features of catatonia during the first mixed episode. These symptoms responded well to electroconvulsive therapy, following which clear affective symptoms emerged. Her affective episode did not respond adequately to olanzapine but improved significantly after the addition of sodium valproate. The difficulties of diagnosing affective episodes in persons with intellectual disabilities are discussed. This case suggests that mixed affective episodes should be considered in the differential diagnosis when poorly elaborated affective and psychotic symptoms are present in a patient with ID.

  15. State-of-the-art Sn2+-based ternary oxides as photocatalysts for water splitting: electronic structures and optoelectronic properties

    KAUST Repository

    Noureldine, Dalal

    2016-09-19

    Developing visible light responsive metal oxide photocatalysts is a challenge that must be conquered to achieve high efficiency for water splitting or hydrogen evolution reactions. Valence band engineering is possible by forming ternary oxides using the combination of a metal cation with an s2d10 electronic configuration and a transition metal oxide with a d0 configuration. Many (Sn2+, Bi3+, Pb2+)-based ternary metal oxide photocatalysts have been reported for hydrogen and/or oxygen evolution under visible irradiation. Sn2+-based materials have attracted particular attention because tin is inexpensive, abundant and more environmentally friendly than lead or bismuth. In this review, we provide a fruitful library for Sn2+-based photocatalysts that have been reported to evolve hydrogen using sacrificial reagents, including SnNb2O6, Sn2Nb2O7, SnTaxNb2−xO6, SnTa2O6, Sn2Ta2O7, SnWO4 (α and β phases), SnSb2O6·nH2O, and Sn2TiO4. The synthesis method used in the literature and the resultant morphology and crystal structure of each compound are discussed. The density functional theory (DFT) calculations of the electronic structure and density of states are provided, and the consequent optoelectronic properties such as band gap, nature of the bandgap, dielectric constant, and effective masses are summarized. This review will help highlight the main challenges for Sn2+-based materials.

  16. State-of-the-art Sn2+-based ternary oxides as photocatalysts for water splitting: electronic structures and optoelectronic properties

    KAUST Repository

    Noureldine, Dalal; Takanabe, Kazuhiro

    2016-01-01

    Developing visible light responsive metal oxide photocatalysts is a challenge that must be conquered to achieve high efficiency for water splitting or hydrogen evolution reactions. Valence band engineering is possible by forming ternary oxides using the combination of a metal cation with an s2d10 electronic configuration and a transition metal oxide with a d0 configuration. Many (Sn2+, Bi3+, Pb2+)-based ternary metal oxide photocatalysts have been reported for hydrogen and/or oxygen evolution under visible irradiation. Sn2+-based materials have attracted particular attention because tin is inexpensive, abundant and more environmentally friendly than lead or bismuth. In this review, we provide a fruitful library for Sn2+-based photocatalysts that have been reported to evolve hydrogen using sacrificial reagents, including SnNb2O6, Sn2Nb2O7, SnTaxNb2−xO6, SnTa2O6, Sn2Ta2O7, SnWO4 (α and β phases), SnSb2O6·nH2O, and Sn2TiO4. The synthesis method used in the literature and the resultant morphology and crystal structure of each compound are discussed. The density functional theory (DFT) calculations of the electronic structure and density of states are provided, and the consequent optoelectronic properties such as band gap, nature of the bandgap, dielectric constant, and effective masses are summarized. This review will help highlight the main challenges for Sn2+-based materials.

  17. Correlation of Mn charge state with the electrical resistivity of Mn doped indium tin oxide thin films

    KAUST Repository

    Kumar, S. R. Sarath; Hedhili, Mohamed N.; Alshareef, Husam N.; Kasiviswanathan, S.

    2010-01-01

    Correlation of charge state of Mn with the increase in resistivity with Mn concentration is demonstrated in Mn-doped indium tin oxide films. Bonding analysis shows that Mn 2p3/2 core level can be deconvoluted into three components corresponding to Mn2+ and Mn4+ with binding energies 640.8 eV and 642.7 eV, respectively, and a Mn2+ satellite at ∼5.4 eV away from the Mn2+ peak. The presence of the satellite peak unambiguously proves that Mn exists in the +2 charge state. The ratio of concentration of Mn2+ to Mn4+ of ∼4:1 suggests that charge compensation occurs in the n-type films causing the resistivity increase.

  18. Correlation of Mn charge state with the electrical resistivity of Mn doped indium tin oxide thin films

    KAUST Repository

    Kumar, S. R. Sarath

    2010-09-15

    Correlation of charge state of Mn with the increase in resistivity with Mn concentration is demonstrated in Mn-doped indium tin oxide films. Bonding analysis shows that Mn 2p3/2 core level can be deconvoluted into three components corresponding to Mn2+ and Mn4+ with binding energies 640.8 eV and 642.7 eV, respectively, and a Mn2+ satellite at ∼5.4 eV away from the Mn2+ peak. The presence of the satellite peak unambiguously proves that Mn exists in the +2 charge state. The ratio of concentration of Mn2+ to Mn4+ of ∼4:1 suggests that charge compensation occurs in the n-type films causing the resistivity increase.

  19. Chemical state analysis of oxide thin films using a high resolution double crystal X-ray fluorescence spectrometer

    International Nuclear Information System (INIS)

    Masuda, Hirohisa; Morinaga, Kenji; Ohta, Yoshio.

    1995-01-01

    The chemical state analysis of r.f.-sputtered amorphous oxide thin films was determined by a high resolution X-ray fluorescence spectrometer with double crystals. The polymerization degree of silicate anions in the silicate film was as same as a target (α-Quartz). The oxygen coordination number of Al 3+ ions in the aluminate film was different from a target (α-Al 2 O 3 ), and it was a mixture of 4 and 6 in a spinel-like structure. In CaO-SiO 2 and CaO-Al 2 O 3 films, when the film thickness is thin at the beginning of sputtering, the composition of films are in the shortage of CaO. But when the film thickness become thicker, the composition of films become as same as the target. From the results above, the chemical state of films and their variations with film thickness can be clarified by using the apparatus. (author)

  20. Microbiological criteria for evaluating the sterility of objects of medical use and drugs: past and present state

    International Nuclear Information System (INIS)

    Gorakova, V.

    1976-01-01

    The past and present status of microbiological criteria for radiosterilization is surveyed, outlining microbiological procedures proposed or used for selecting sterilizing doses, controlling sterilization, and checking sterility. Differences of opinion on questions of international standardization are noted and a possible method of dealing with checklists is proposed. (author)