Titanium impregnated borosilicate zeolites for epoxidation catalysis

Czech Academy of Sciences Publication Activity Database

Přech, Jan; Vitvarová, Dana; Lupínková, Lenka; Kubů, Martin; Čejka, Jiří

2015-01-01

Roč. 212, AUG 2015 (2015), s. 28-34 ISSN 1387-1811 R&D Projects: GA ČR GAP106/11/0819 Institutional support: RVO:61388955 Keywords : borosilicate * titanium impregnation * epoxidation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.349, year: 2015

Sulphate Incorporation in Borosilicate Glasses and Melts: a Kinetic Approach

Energy Technology Data Exchange (ETDEWEB)

Lenoir, M. [CEA, DEN, Laboratoire d' etude et de Developpement de Matrices de Conditionnement, Centre de Marcoule, 30207 Bagnols-sur-Ceze (France); Physique des Mineraux et Magmas, UMR 7047, CNRS- Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris 05 (France); Grandjean, A. [Institut de Chimie Separative de Marcoule, UMR 5257, Laboratoire des Nanomateriaux Autoreparants, Marcoule, 30207 Bagnols-sur-Ceze (France); Dussossoy, J.L. [CEA, DEN, Laboratoire d' etude et de Developpement de Matrices de Conditionnement, Centre de Marcoule, 30207 Bagnols-sur-Ceze (France); Neuville, D.R. [Physique des Mineraux et Magmas, UMR 7047, CNRS- Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris 05 (France)

2008-07-01

The kinetics of sulphate departure in a sodium borosilicate melt were studied using in situ Raman spectroscopy. This technique allows the quantification of the amount of sulphate dissolved in a borosilicate glass as a function of heating time by comparison with measurements obtained by microprobe wavelength dispersive spectrometry. To quantify the sulphate content obtained with Raman spectroscopy, the integrated intensity of the sulphate band at 990 cm{sup -1} was scaled to the sum of the integrated bands between 800 and 1200 cm{sup -1}, bands that are assigned to Qn silica units on the basis of previous literature. Calibration curves were then determined for two different samples. An evaluation of the kinetics of departure of sulphate could thus be made as a function of the viscosity of the borosilicate glass, showing that the kinetics were controlled by the diffusion of sulphate and its volatilization from the melt. This experimental method allows in situ measurements of sulphate content at high temperature which cannot be obtained by any other simple technique. (authors)

Low Velocity Sphere Impact of a Borosilicate Glass

Energy Technology Data Exchange (ETDEWEB)

Morrissey, Timothy G [ORNL; Ferber, Mattison K [ORNL; Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL

2012-05-01

This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Borofloat borosilicate glass, and is a follow-up to a similar study completed by the authors on Starphire soda-lime silicate glass last year. The response of the borosilicate glass to impact testing at different angles was also studied. The Borofloat glass was supplied by the US Army Research Laboratory and its tin-side was impacted or indented. The intent was to better understand low velocity impact response in the Borofloat. Seven sphere materials were used whose densities bracket that of rock: borosilicate glass, soda-lime silicate glass, silicon nitride, aluminum oxide, zirconium oxide, carbon steel, and a chrome steel. A gas gun or a ball-drop test setup was used to produce controlled velocity delivery of the spheres against the glass tile targets. Minimum impact velocities to initiate fracture in the Borofloat were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the seven sphere-Borofloat-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) BS glass responded similarly to soda-lime silicate glass when spherically indented but quite differently under sphere impact conditions; (2) Frictional effects contributed to fracture initiation in BS glass when it spherically indented. This effect was also observed with soda-lime silicate glass; (3) The force necessary to initiate fracture in BS glass under spherical impact decreases with increasing elastic modulus of the sphere material. This trend is opposite to what was observed with soda-lime silicate glass. Friction cannot explain this trend and the authors do not have a legitimate explanation for it yet; (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than under quasi-static conditions. That

Radiation response of cubic mesoporous silicate and borosilicate thin films

Science.gov (United States)

Manzini, Ayelén; Alurralde, Martín; Luca, Vittorio

2018-01-01

The radiation response has been studied of cubic mesoporous silicate and borosilicate thin films having different boron contents prepared using the block copolymer template Brij 58 and the dip coating technique. The degree of pore ordering of the films was analysed using low-angle X-ray diffraction and film thickness measured by X-ray reflectivity. For films calcined at 350 °C, the incorporation of boron resulted in a reproducible oscillatory variation in the d-spacing and intensity of the primary reflection as a function of boron content. A clear peak was observed in the d-spacing at 5-10 mol% boron incorporation. For borosilicate films of a given composition an overall suppression of d-spacing was observed as a function of aging time relative to films that did not contain boron. This was ascribed to a slow condensation process. The films were irradiated in pile with neutrons and with iodine ions at energies of 180 keV and 70 MeV. Neutron irradiation of the silicate thin films for periods up to 30 days and aged for 400 days resulted in little reduction in either d-spacing or intensity of the primary low-angle X-ray reflection indicating that the films retained their mesopore ordering. In contrast borosilicate films for which the B (n, α) reaction was expected to result in enhanced displacement damage showed much larger variations in X-ray parameters. For these films short irradiation times resulted in a reduction of the d-spacing and intensity of the primary reflections considerably beyond that observed through aging. It is concluded that prolonged neutron irradiation and internal α irradiation have only a small, although measurable, impact on mesoporous borosilicate thin films increasing the degree of condensation and increasing unit cell contraction. When these borosilicate films were irradiated with iodine ions, more profound changes occurred. The pore ordering of the films was significantly degraded when low energy ions were used. In some cases the degree

Effects of system size and cooling rate on the structure and properties of sodium borosilicate glasses from molecular dynamics simulations.

Science.gov (United States)

Deng, Lu; Du, Jincheng

2018-01-14

Borosilicate glasses form an important glass forming system in both glass science and technologies. The structure and property changes of borosilicate glasses as a function of thermal history in terms of cooling rate during glass formation and simulation system sizes used in classical molecular dynamics (MD) simulation were investigated with recently developed composition dependent partial charge potentials. Short and medium range structural features such as boron coordination, Si and B Q n distributions, and ring size distributions were analyzed to elucidate the effects of cooling rate and simulation system size on these structure features and selected glass properties such as glass transition temperature, vibration density of states, and mechanical properties. Neutron structure factors, neutron broadened pair distribution functions, and vibrational density of states were calculated and compared with results from experiments as well as ab initio calculations to validate the structure models. The results clearly indicate that both cooling rate and system size play an important role on the structures of these glasses, mainly by affecting the 3 B and 4 B distributions and consequently properties of the glasses. It was also found that different structure features and properties converge at different sizes or cooling rates; thus convergence tests are needed in simulations of the borosilicate glasses depending on the targeted properties. The results also shed light on the complex thermal history dependence on structure and properties in borosilicate glasses and the protocols in MD simulations of these and other glass materials.

Effects of system size and cooling rate on the structure and properties of sodium borosilicate glasses from molecular dynamics simulations

Science.gov (United States)

Deng, Lu; Du, Jincheng

2018-01-01

Borosilicate glasses form an important glass forming system in both glass science and technologies. The structure and property changes of borosilicate glasses as a function of thermal history in terms of cooling rate during glass formation and simulation system sizes used in classical molecular dynamics (MD) simulation were investigated with recently developed composition dependent partial charge potentials. Short and medium range structural features such as boron coordination, Si and B Qn distributions, and ring size distributions were analyzed to elucidate the effects of cooling rate and simulation system size on these structure features and selected glass properties such as glass transition temperature, vibration density of states, and mechanical properties. Neutron structure factors, neutron broadened pair distribution functions, and vibrational density of states were calculated and compared with results from experiments as well as ab initio calculations to validate the structure models. The results clearly indicate that both cooling rate and system size play an important role on the structures of these glasses, mainly by affecting the 3B and 4B distributions and consequently properties of the glasses. It was also found that different structure features and properties converge at different sizes or cooling rates; thus convergence tests are needed in simulations of the borosilicate glasses depending on the targeted properties. The results also shed light on the complex thermal history dependence on structure and properties in borosilicate glasses and the protocols in MD simulations of these and other glass materials.

Utilization of borosilicate glass for transuranic waste immobilization

International Nuclear Information System (INIS)

Ledford, J.A.; Williams, P.M.

1979-01-01

Incinerated transuranic waste and other low-level residues have been successfully vitrified by mixing with boric acid and sodium carbonate and heating to 1050 0 C in a bench-scale continuous melter. The resulting borosilicate glass demonstrates excellent mechanical durability and chemical stability

Rutherford backscattering investigation of the corrosion of borosilicate glass

International Nuclear Information System (INIS)

Sales, B.C.; Boatner, L.A.; Naramoto, H.; White, C.W.

1981-10-01

The RBS spectra from Frit 21 borosilicate glasses doped with 5 wt % UO 2 , SrO, or Cs 2 O show that: during the initial stages of leaching (0 to 3 h) there is a substantial (300 to 500%) enhancement in the concentration of U, Sr, Ca, and Ti in the outer surface layer and that this enhancement is accompanied by a large depletion of Na, Si, and Cs; and upon further leaching under static conditions (24 h) the leached surface layer composition is indistinguishable from the unleached surface. Other borosilicate glasses such as PNL 76-68 may eventually show the same behavior if the final equilibrium pH value is greater than 9. The technique of Rutherford backscattering depth profile analysis can be a powerful tool for investigating the initial stages of glass corrosion

3.6. The kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to kinetics of sulfuric acid decomposition of calcined concentrate of borosilicate ore. The experimental data of kinetics of extraction of boron oxide from danburite at sulfuric acid decomposition were obtained at 20-90 deg C temperature range and process duration 15-90 minutes. The flowsheet of obtaining of boric acid from borosilicate ores of Ak-Arkhar Deposit by sulfuric acid method was proposed.

IR study of Pb–Sr titanate borosilicate glasses

Indian Academy of Sciences (India)

Administrator

IR study of Pb–Sr titanate borosilicate glasses. C R GAUTAM*, DEVENDRA KUMAR. † and OM PARKASH. †. Department of Physics, University of Lucknow, Lucknow 226 007, India. †. Department of Ceramic Engineering, Institute of Technology, Banaras Hindu University, Varanasi 221 005, India. MS received 3 January ...

Design and test of the borosilicate glass burnable poison rod for Qinshan nuclear power plant core

International Nuclear Information System (INIS)

Huang Jinhua; Sun Hanhong

1988-08-01

Material for the burnable poison of Qinshan Nuclear Power Plant core is GG-17 borosilicate glass. The chemical composition and physico-chemical properties of GG-17 is very close to Pyrex-7740 glass used by Westinghouse. It is expected from the results of the experiments that the borosilicate glass burnable poison rod can be successfully used in Qinshan Nuclear Power Plant due to good physical, mechanical, corrosion-resistant and irradiaton properties for both GG-17 glass and cold-worked stainless steel cladding. Change of material for burnable poison from boron-bearing stainless steel to borosilicate glass will bring about much more economic benefit to Qinshan Naclear Power Plant

Borosilicate glass as a matrix for the immobilization of Savannah River Plant waste

International Nuclear Information System (INIS)

Plodinec, M.J.; Wicks, G.G.; Bibler, N.E.

1982-01-01

The reference waste form for immobilization of Savannah River Plant (SRP) waste is borosilicate glass. In the reference process, waste is mixed with glass-forming chemicals and melted in a Joule-heated ceramic melter at 1150 0 C. Waste glass made with actual or simulated waste on a small scale and glass made with simulated waste on a large scale confirm that the current reference process and glass-former composition are able to accommodate all SRP waste compositions and can produce a glass with: high waste loading; low leach rates; good thermal stability; high resistance to radiation effects; and good impact resistance. Borosilicate glass has been studied as a matrix for the immobilization of SRP waste since 1974. This paper reviews the results of extensive characterization and performance testing of the glass product. These results show that borosilicate glass is a very suitable matrix for the immobilization of SRP waste. 18 references, 3 figures, 10 tables

Assessment of Savannah River borosilicate glass in the repository environment

International Nuclear Information System (INIS)

Plodinec, M.J.; Wicks, G.G.; Bibler, N.E.

1982-04-01

Since 1973, borosilicate glass has been studied as a matrix for the immobilization of high-level radioactive waste generated at the Savannah River Plant (SRP). In 1977, efforts began to develop and test the large-scale equipment necessary to convert the alkaline waste slurries at SRP into a durable borosilicate glass. A process has now been developed for the proposed Defense Waste Processing Facility (DWPF) which will annually produce approximately 500 canisters of SRP waste glass which will be stored on an interim basis on the Savannah River site. Current national policy calls for the permanent disposal of high-level waste in deep geologic repositories. In the repository environment, SRP waste glass will eventually be exposed to such stresses as lithostatic or hydrostatic pressures, radiation fields, and self-heating due to radioactive decay. In addition, producing and handling each canister of glass will also expose the glass to thermal and mechanical stresses. An important objective of the extensive glass characterization and testing programs of the Savannah River Laboratory (SRL) has been to determine how these stresses affect the performance of SRP waste glass. The results of these programs indicate that: these stresses will not significantly affect the performance of borosilicate glass containing SRP waste; and SRP waste glass will effectively immobilize hazardous radionuclides in the repository environment

Chemical durability of lead borosilicate glass matrix under simulated geological conditions

International Nuclear Information System (INIS)

Yalmali, Vrunda S.; Deshingkar, D.S.; Wattal, P.K.

2002-03-01

The lead borosilicate glass has been developed for vitrification of High Level Waste (HLW) stored at Trombay. This waste is contains especially high contents of sodium, uranium sulphate and iron. The glasses containing HLW are to be ultimately disposed into deep geological repositories. Long term leach rates under simulated geological conditions need to be evaluated for glass matrix. Studies were taken up to estimate the lead borosilicate glass WTR-62 matrix for chemical durability in presence of synthetic ground water. The leachant selected was based on composition of ground water sample near proposed repository site. In the first phase of these tests, the experiments were conducted for short duration of one and half month. The leaching experiments were conducted in presence of a) distilled water b) synthetic ground water c) synthetic ground water containing granite, bentonite and ferric oxide and d) synthetic ground water containing humic acid at 100 0 C. The leachate samples were analysed by pHmetry , ion chromatography and UV -VIS spectrophotometry. The normalised leach rates for lead borosilicate WTR- 62 glass matrix based on silica, boron and sulphate analyses of leachates were of the order of 10 -3 to 10 -5 gms/cm 2 /day for 45 days test period in presence of synthetic ground water as well as in presence of other materials likely to be present along with synthetic ground water. These rates are comparable to those of sodium borsilicate glass matrices reported in literature. It is known that the leach rates of glass matrix decrease with longer test durations due to formation of leached layer on its surface. The observed leach rates of lead borosilicate WTR- 62 glass matrix for 45 day tests under simulated geological conditions were found to be sufficiently encouraging to take up long term tests for evaluating its performances under repository conditions. (author)

Alteration of borosilicate glass under water saturated condition

International Nuclear Information System (INIS)

Tsukimura, K.; Matsuhisa, Y.; Kanai, Y.; Hirai, H.

1991-01-01

In the long term of the high-level nuclear waste disposal, the dissolving rates of radionuclides from the waste will be controlled by crystalline phases secondarily formed in the borosilicate glass by reaction with ground water. We have determined the crystalline phases formed from borosilicate glass in a hydrothermal experiment. Borosilicate glass powder (50 mg, Si 40 B 20 Al 4 Li 12 Na 14 K 3 Ca 2 Fe 5 O 140 ) and 200 ml of water were reacted at 300degC and 300 bars for 2 weeks with a cold-seal type hydrothermal high pressure apparatus. After the reaction the liquid phase was analyzed with atomic absorption spectroscopy and the solid phases with x-ray powder diffraction and analytical electron microscopy. The liquid phase contains 58 % of Na, 14 % of Li and 11 % of K but less than 1 % of Ca and Fe. The solid phases were found to be zeolite and smectite. The zeolite is isostructural with analcime Na 2 Al 2 (SiO 3 ) 4 · 2H 2 O or wairakite CaAl 2 (SiO 3 ) 4 · 2H 2 O and contains Ca and Si as major constituents but does not contain Al. Although no direct analytical evidence is available, logical induction of the experimental results indicates that the chemical composition of the zeolite is CaB 2 (SiO 3 ) 4 . The remaining x-ray powder diffraction peaks are same as those of smectite Na 06.7 (Al 3.33 Mg 0.67 )Si 8 O 20 (OH) 4 . However, since our starting material was free of Mg, and Na was not detected by AEM, the smectite may contain Fe instead of Mg, and Li instead of Na. (author)

Phase separation of cesium from lead borosilicate glass by heat treatment under a reducing atmosphere

Energy Technology Data Exchange (ETDEWEB)

Xu, Zhanglian; Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp; Nishimura, Fumihiro; Yonezawa, Susumu

2016-11-05

Highlights: • Cesium was phase separated from lead borosilicate glass under a reductive atmosphere. • The phase separation occurred on the glass surface that was in contact with the gas. • The leachability of cesium was enhanced by the phase separation. • The degree of such enhancement varied depending on the heat treatment conditions. - Abstract: A phase-separation technique for removing sodium from glass using a heat-treatment method under a reducing atmosphere was previously developed for sodium recovery from waste glass. In this study, this technique was applied to cesium-containing lead borosilicate glass to concentrate the cesium in phase-separated sodium-rich materials for efficient cesium extraction. The theoretical phase-separation temperature of the sodium-rich phase was simulated by thermodynamic equilibrium calculations and was predicted to occur below 700 °C for lead borosilicate glass. Experimentally, a simulated lead borosilicate glass was melted at 1000 °C and subsequently annealed below 700 °C under a CO-containing reducing atmosphere. The phase separation of cesium was found to occur with sodium enrichment on the glass surface that was in contact with the gas phase, promoting cesium extraction from the treated glass using water. The cesium extraction efficiency was affected by the surface area of the treated glass that was in contact with water, and under the examined conditions, the cesium extraction efficiency was up to 66%. Phase separation using reductive heat treatment, combined with a water leaching technique, is suggested to be effective for extracting cesium incorporated in borosilicate glass waste.

High-level waste borosilicate glass a compendium of corrosion characteristics. Volume 1

International Nuclear Information System (INIS)

Cunnane, J.C.

1994-03-01

Current plans call for the United States Department of Energy (DOE) to start up facilities for vitrification of high-level radioactive waste (HLW) stored in tanks at the Savannah River Site, Aiken, South Carolina, in 1995; West Valley Demonstration Project, West Valley, New York, in 1996; and at the Hanford Site, Richland, Washington, after the year 2000. The product from these facilities will be canistered HLW borosilicate glass, which will be stored, transported, and eventually disposed of in a geologic repository. The behavior of this glass waste product, under the range of likely service conditions, is the subject of considerable scientific and public interest. Over the past few decades, a large body of scientific information on borosilicate waste glass has been generated worldwide. The intent of this document is to consolidate information pertaining to our current understanding of waste glass corrosion behavior and radionuclide release. The objective, scope, and organization of the document are discussed in Section 1.1, and an overview of borosilicate glass corrosion is provided in Section 1.2. The history of glass as a waste form and the international experience with waste glass are summarized in Sections 1.3 and 1.4, respectively

Optical and structural investigation on sodium borosilicate glasses doped with Cr2O3

Science.gov (United States)

Ebrahimi, E.; Rezvani, M.

2018-02-01

In this work, Sodium borosilicate glasses with chemical composition of 60% SiO2-20% B2O3-20%Na2O doped with different contents of Cr2O3 were prepared by melting-quenching method. Physical, structural and optical properties of glasses were investigated by studying density and molar volume, Fourier Transform Infrared (FT-IR) Spectra and UV-visible absorption spectroscopy. The results showed an increase in density of glasses with the increase of Cr2O3 that can be due to addition of oxide with high molar mass. The optical absorption spectra of un-doped glass reveals UV absorption due to trace iron impurities with no visible band however Cr2O3 doped glasses shows absorption in visible range that are characteristic. Increasing of Cr3 + ions in the glassy microstructure of samples provides a semiconducting character to Sodium borosilicate glass by reducing the direct and indirect optical band gaps of glass samples from 3.79 to 2.59 (ev) and 3.36 to 2.09 (ev), respectively. These changes could be attributed to the role of Cr3 + ions as the network former which asserts improvement of semiconducting behavior in presence of Cr2O3.

A Raman spectroscopy study on the effects of intermolecular hydrogen bonding on water molecules absorbed by borosilicate glass surface

Science.gov (United States)

Li, Fabing; Li, Zhanlong; Wang, Ying; Wang, Shenghan; Wang, Xiaojun; Sun, Chenglin; Men, Zhiwei

2018-05-01

The structural forms of water/deuterated water molecules located on the surface of borosilicate capillaries have been first investigated in this study on the basis of the Raman spectral data obtained at different temperatures and under atmospheric pressure for molecules in bulk and also for molecules absorbed by borosilicate glass surface. The strongest two fundamental bands locating at 3063 cm-1 (2438 cm-1) in the recorded Raman spectra are assigned here to the Osbnd H (Osbnd D) bond stretching vibrations and they are compared with the corresponding bands observed at 3124 cm-1 (2325 cm-1) in the Raman spectrum of ice Ih. Our spectroscopic observations have indicated that the structure of water and deuterated water molecules on borosilicate surface is similar to that of ice Ih (hexagonal phase of ice). These observations have also indicated that water molecules locate on the borosilicate surface so as to construct a bilayer structure and that strong and weak intermolecular hydrogen bonds are formed between water/deuterated molecules and silanol groups on borosilicate surface. In accordance with these findings, water and deuterated water molecules at the interface of capillary have a higher melting temperature.

Aqueous corrosion of borosilicate glasses. Nature and properties of alteration layers

International Nuclear Information System (INIS)

Trotignon, Laurent

1990-01-01

This research thesis addresses physical and chemical processes which occur during aqueous corrosion of silicates, and the study of the properties of their interfaces with solutions, and thus issues related to the fate of high activity nuclear wastes which are embedded in a vitreous matrix as the potential release of radionuclides towards the environment then depends on the glass parcel behaviour submitted to chemical attacks which could alter it, notably by aqueous corrosion. The objective is then to model the dissolution of nuclear glass over long periods of time, and to predict the behaviour of radionuclides. The author compared the corrosion and alteration layers of gradually more complex borosilicate glasses, from a ternary sodium borosilicate glass to a simulated nuclear glass (the French reference glass R7T7). Complexity is increased by adding oxides. After some theoretical recalls on the structure and corrosion of borosilicate glasses, the author presents the studied materials, the corrosion experiments, and analytical techniques used to study alteration layers. The mechanism of formation of altered layers is studied based on corrosion experiments performed at 90 C on the whole set of glasses. Alteration layers formed on corroded glasses are studied and compared by using various techniques: electronic microscopy, high energy ion beams, spectroscopy, infrared, photo-electron spectroscopy. Implications for underground storage of nuclear glasses are discussed

Quantitative estimation of electro-osmosis force on charged particles inside a borosilicate resistive-pulse sensor.

Science.gov (United States)

Ghobadi, Mostafa; Yuqian Zhang; Rana, Ankit; Esfahani, Ehsan T; Esfandiari, Leyla

2016-08-01

Nano and micron-scale pore sensors have been widely used for biomolecular sensing application due to its sensitive, label-free and potentially cost-effective criteria. Electrophoretic and electroosmosis are major forces which play significant roles on the sensor's performance. In this work, we have developed a mathematical model based on experimental and simulation results of negatively charged particles passing through a 2μm diameter solid-state borosilicate pore under a constant applied electric field. The mathematical model has estimated the ratio of electroosmosis force to electrophoretic force on particles to be 77.5%.

Preparation and characterization of an improved borosilicate glass for the solidification of high level radioactive fission product solutions (HLW). Pt. 2

International Nuclear Information System (INIS)

Kahl, L.; Ruiz-Lopez, M.C.; Saidl, J.; Dippel, T.

1982-04-01

In the 'Institut fuer Nuklare Entsorgungstechnik' the borosilicate glass VG 98/12 has been developed for the solidification of the high level radioactive waste (HLW). This borosilicate glass can be used in a direct heated ceramic melter and forms together with the HLW the borosilicate glass product GP 98/12. This borosilicate glass product has been examined in detail both in liquid and solid state. The elements contained in the HLW can be incorporated without problems. Only in a few exceptions the concentration must be kept below certain limits to exclude the formation of a second phase ('yellow phase') by separation. No spontaneous crystallization and no crystallization over a long time could be observed as long as the temperature of the borosilicate glass product is kept below its transformation area. Simulating accidental conditions in the final storage, samples had been leached at temperatures up to 200 0 C and pressures up to 130 bar with saturated rock salt brine and saturated quinary salt brine. The leaching process seems to be stopped by the formed 'leached layer' on the surface of the borosilicate glass product after a limited leaching time. Detailed investigations have been started to explain this phenomenon. (orig.) [de

Investigation on neptunium in a borosilicate glass

International Nuclear Information System (INIS)

Poirot, I.

1988-03-01

The oxidization state and coordination of neptunium, introduced as dopant in borosilicate glasses were studied through optical, Mossbauer spectroscopies and magnetic measurements. The neptunium oxide, introduced previously as NpO 2 is reduced during the melting process of the glass. This leads to an equilibrium in which the ratio of Np 4+ to Np 3+ valences depends on experimental conditions. Spectroscopic analysises conduct to postulate the presence of different sites for each of the oxydation states of neptunium [fr

Mechanical behavior of cellular borosilicate glass with pressurized Ar-filled closed pores

International Nuclear Information System (INIS)

Wang Bo; Matsumaru, Koji; Yang Jianfeng; Fu Zhengyi; Ishizaki, Kozo

2012-01-01

High strength borosilicate foams were fabricated by melting glass powder under high-pressure argon gas and subsequent heat treatment of the glass bulk at atmospheric pressure. In the first step, borosilicate glass powder was melted at 1100 °C for 1 h by capsule-free hot isostatic pressing (HIPing) under a high gas pressure of 10–70 MPa. Pressurized Ar-filled spherical pores were introduced into the glass, and argon atoms were dissolved in the glass network structure. The expansion of argon-filled pores and the release of the dissolved Ar gas resulted in the formation of pressurized Ar-filled closed pores by isothermal heat treatment at 800 °C for 10 min. A high porosity of up to 80% with a bimodal distribution of micro-size cells was obtained for the resultant cellular borosilicate glass. By increasing the total gas pressure from 10 to 70 MPa, the compressive strength and the Young’s modulus were increased considerably from 15 to 52 MPa and from 4.1 to 12.6 GPa, respectively, which can be substantially attributed to the high collapse stress from the high enclosed gas pressure. The cellular glass with a high porosity showed a large failure strain under uniaxial compression.

The borosilicate glass for 'PAMELA'

International Nuclear Information System (INIS)

Schiewer, E.

1986-01-01

The low enriched waste concentrate (LEWC) stored at Mol, Belgium, will be solidified in the vitrification plant 'PAMELA'. An alkali-borosilicate glass was developed by the Hahn-Meitner-Institut, Berlin, which dissolves (11 +- 3)wt% waste oxides while providing sufficient flexibility for changes in the process parameters. The development of the glass labelled SM513LW11 is described. Important properties of the glass melt (viscosity, resistivity, formation of yellow phase) and of the glass (corrosion in aqueous solutions, crystallization) are reported. The corrosion data of this glass are similar to those of other HLW-glasses. Less than five wt% of crystalline material are produced upon cooling of large glass blocks. Crystallization does not affect the chemical durability. (Auth.)

Investigation of U3O8 immobilization in the GP-91 borosilicate glass by induction melter with a cold crucible (CCIM)

International Nuclear Information System (INIS)

Matyunin, Y.I.; Demin, A.V.; Smelova, T.V.; Yudintsev, S.V.; Lapina, M.I.

1997-01-01

One of the most promising and intensively developed methods for the solidification of high-level wastes is their vitrification with the use of a cold crucible induction melter (CCIM), which offers a number of advantages over ceramic melter. This work is concerned with comparison studies on the behavior of uranium in vitreous borosilicate materials synthesized by the traditional technique (melting in muffle furnaces) and CCIM method. The incorporation of uranium oxide U 3 O 8 into the GP-91 borosilicate glass with the use of CCIM technology is investigated. The limiting solubility of uranium in the GP-91 borosilicate glass is evaluated. The phase composition of precipitated dispersed particles based on uranium is determined. Some physicochemical properties of synthesized materials are explored. Investigations into the behavior of uranium in borosilicate glass prepared in the CCIM show a feasibility to synthesize the X-ray amorphous homogeneous borosilicate glasses incorporating as much as 25 - 28 wt% uranium, which is 4 - 5 times larger than that in glasses obtained by the traditional method. (author)

Preliminary assessment of modified borosilicate glasses for chromium and ruthenium immobilization

Energy Technology Data Exchange (ETDEWEB)

Farid, Osama M. [Reactors Department, Nuclear Research Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt); Centre of Nuclear Engineering (CNE), Department of Materials, Imperial College London, London, SW7 2BP (United Kingdom); Abdel Rahman, R.O., E-mail: alaarehab@yahoo.com [Hot Laboratory Center, Atomic Energy Authority of Egypt, P.O. 13759, Inshas, Cairo (Egypt)

2017-01-15

The feasibility of using modified alkali borosilicate glasses for ruthenium and chromium immobilization is preliminary assessed by investigating the immobilization system structure under normal conditions. Within this context, reference alkali borosilicate, and simulated Magnox-modified glasses were prepared and studied. The results indicate that ruthenium is immobilized in the vitreous structure as encapsulated RuO{sub 2} crystallites that act as seeds for heterogeneous nucleation of other crystalline phases. The presence of Zn, as modifier, has contributed to chromium immobilization in zincochromite spinel structure, whereas Ca is accommodated in the vitreous structure. Immobilization performance was evaluated by conducting conservative static leach test and studying the leached glass. Leached glass morphology was altered, where near surface reference glass is leached over 400 nm and simulated Magnox-modified sample is altered over 300 nm. Normalized release rates are within normal range for borosilicate material. For simulated Magnox-modified sample, Ca and alkali structural element, i.e. Na and Li, are leached via ion-exchange reaction. The ion-exchanged fraction equals 1.06 × 10{sup −8} mol/m{sup 2} s and chromium has slightly lower normalized release rate value than ruthenium. - Highlights: • The presence of modifiers and waste oxides led to localized de-vitrification. • Ruthenium is encapsulated within the vitreous glass network as RuO{sub 2} crystals. • Chromium is immobilized within the zincochromite spinel structure. • Pitting and cracks induced by leaching did not affect the immobilization performance.

A kinetic approach of sulphur behaviour in borosilicate glasses and melts: implications for sulphate incorporation in nuclear waste glasses

Energy Technology Data Exchange (ETDEWEB)

Lenoir, Marion [Service de Confinement des Dechets et Vitrification - Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols sur Ceze (France); Physique des Mineraux et des Magmas, UMR 7047 - CNRS, Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris Cedex 05 (France); Grandjean, Agnes [Service de Confinement des Dechets et Vitrification - Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols sur Ceze (France); Neuville, Daniel R. [Physique des Mineraux et des Magmas, UMR 7047 - CNRS, Institut de Physique du Globe de Paris, 7 place Jussieu, 75252 Paris Cedex 05 (France)

2008-07-01

The kinetics of sulphate decomposition in a borosilicate melt were studied using in situ Raman spectroscopy. This technique permits the quantification of the amount of sulphate dissolved in a borosilicate glass as a function of heating time by comparison with measurements obtained by microprobe WDS (Wavelength Dispersive Spectrometry). In order to quantify the content of sulphate obtained by Raman spectroscopy, the integrated intensity of the sulphate band at 985 cm{sup -1} was scaled to the sum of the integrated bands between 800 and 1200 cm{sup -1}, bands that are assigned to Q{sup n} silica units on the basis of previous literature. Viscosities of some borosilicate glasses are also presented here in order to study the kinetics of sulphate decomposition as a function of the viscosity of the melt. This underlines the importance of variations in viscosity depending on the composition of the melt and thus shows that viscosity is an important parameter governing the kinetics of decomposition of sulphate in borosilicate glasses. (authors)

Comparison of SRP high-level waste disposal costs for borosilicate glass and crystalline ceramic waste forms

International Nuclear Information System (INIS)

McDonell, W.R.

1982-04-01

An evaluation of costs for the immobilization and repository disposal of SRP high-level wastes indicates that the borosilicate glass waste form is less costly than the crystalline ceramic waste form. The wastes were assumed immobilized as glass with 28% waste loading in 10,300 reference 24-in.-diameter canisters or as crystalline ceramic with 65% waste loading in either 3400 24-in.-diameter canisters or 5900 18-in.-diameter canisters. After an interim period of onsite storage, the canisters would be transported to the federal repository for burial. Total costs in undiscounted 1981 dollars of the waste disposal operations, excluding salt processing for which costs are not yet well defined, were about $2500 million for the borosilicate glass form in reference 24-in.-diameter canisters, compared to about $2900 million for the crystalline ceramic form in 24-in.-diameter canisters and about $3100 million for the crystalline ceramic form in 18-in.-diameter canisters. No large differences in salt processing costs for the borosilicate glass and crystalline ceramic forms are expected. Discounting to present values, because of a projected 2-year delay in startup of the DWPF for the crystalline ceramic form, preserved the overall cost advantage of the borosilicate glass form. The waste immobilization operations for the glass form were much less costly than for the crystalline ceramic form. The waste disposal operations, in contrast, were less costly for the crystalline ceramic form, due to fewer canisters requiring disposal; however, this advantage was not sufficient to offset the higher development and processing costs of the crystalline ceramic form. Changes in proposed Nuclear Regulatory Commission regulations to permit lower cost repository packages for defense high-level wastes would decrease the waste disposal costs of the more numerous borosilicate glass forms relative to the crystalline ceramic forms

Conversion of radwaste-loaded zeolites into a borosilicate glass to improve their properties for final disposal (preliminary results)

International Nuclear Information System (INIS)

Kazemian, H.; Ghannadi Maraghe, M.; Mallah, M.H.; Firooz Zare, M.; Kooshkestani, R.; Naghavi, S.Sh.

2002-01-01

Research was undertaken to fix radioisotopes from simulated nuclear waste streams into durable and stable borosilicate glass matrices based on the conversion of different type of zeolites. It was found that the selectivity of Iranian clinoptilolite and the relevant synthetic zeolite toward cesium and strontium were quite good whereas the leach resistance of the loaded zeolite was relatively poor. To improve the leach resistance of the used zeolites, conversion of the spent exchangers into borosilicate glass was investigated. Results obtained in the non active bench scale tests phase were promising. It is concluded that spent zeolites loaded with radioactive materials can be converted into a durable, high leach resistant borosilicate glass, a proper matrix for final disposal of nuclear waste. (author)

Er3+-Al2O3 nanoparticles doping of borosilicate glass

International Nuclear Information System (INIS)

Massera, Jonathan; Petit, Laeticia; Hupa, Leena; Hupa, Mikko; Koponen, Joona; Glorieux, Benoit

2015-01-01

Novel borosilicate glasses were developed by adding in the glass batch Er 3+ -Al 2 O 3 nanoparticles synthetized by using a soft chemical method. A similar nanoparticle doping with modified chemical vapour deposition (MCVD) process was developed to increase the efficiency of the amplifying silica fibre in comparison to using MCVD and solution doping. It was shown that with the melt quench technique, a Er 3+ -Al 2 O 3 nanoparticle doping neither leads to an increase in the Er 3+ luminescence properties nor allows one to control the rare-earth chemical environment in a borosilicate glass. The site of Er 3+ in the Er 3+ -Al 2 O 3 nanoparticle containing glass seems to be similar as in glasses with the same composition prepared using standard raw materials. We suspect the Er 3+ ions to diffuse from the nanoparticles into the glass matrix. There was no clear evidence of the presence of Al 2 O 3 nanoparticles in the glasses after melting. (author)

Evaluation of long-term leaching of borosilicate glass in pure water

International Nuclear Information System (INIS)

Lanza, F.; Parnisari, E.

1979-01-01

In order to confirm the validity of the model of the dissolving sphere, a series of tests of leaching of borosilicate glasses has been performed. The leaching rate is followed by measurements of weight loss and analysis of the surface composition. An accumulation at the surface of the less soluble cations is observed

X-ray irradiation induced reduction and nanoclustering of lead in borosilicate glass

NARCIS (Netherlands)

Stanley, H.B.; Banerjee, D.; Breemen, van L.C.A.; Ciston, J.; Liebscher, C.H.; Martis, V.; Merino, D.H.; Longo, A.; Pattison, P.; Peters, G.W.M.; Portale, G.; Sen, Sabyasachi; Bras, W.

2014-01-01

We have studied the formation of nanoparticles in lead sulfide (PbS)-doped borosilicate glass subjected to a two-step nucleation and growth heat treatment using in situ small-angle X-ray scattering (SAXS). The microstructure produced was subsequently characterized using X-ray powder diffraction

Chemical durability of borosilicate glasses containing simulated high-level nuclear wastes, 1

International Nuclear Information System (INIS)

Hara, Shigeo; Terai, Ryohei; Yamanaka, Hiroshi

1983-01-01

The Soxhlet-type leaching test apparatus has been developed to evaluate the chemical durability of some borosilicate glasses containing simulated High-Level nuclear Wastes, HLW. After the leaching over the temperature range of 50 0 -95 0 C, the weight loss of specimens with time was determined on both the samples of blocks and grains, and various components dissolved into water were analyzed by atomic absorption and colorimetry technique. It was found that Soxhlet-type test method was more useful than JIS test method, because the specimens in Soxhlet type apparatus were forced always to react with pure water and the mechanism of leaching could be evaluate accurately. The chemical durability of commercial glasses decreases generally with increasing of alkali contents in glasses. In the case of these borosilicate glasses containing HLW, however, the leachability was apparently independent on the alkali contents because of the complexity of these glass compositions. The variation of leaching rate with temperature suggests that dissolution mechanism changes with temperature. (author)

X-ray absorption and Raman spectroscopy studies of molybdenum environments in borosilicate waste glasses

Science.gov (United States)

McKeown, David A.; Gan, Hao; Pegg, Ian L.

2017-05-01

Mo-containing high-level nuclear waste borosilicate glasses were investigated as part of an effort to improve Mo loading while avoiding yellow phase crystallization. Previous work showed that additions of vanadium decrease yellow phase formation and increases Mo solubility. X-ray absorption spectroscopy (XAS) and Raman spectroscopy were used to characterize Mo environments in HLW borosilicate glasses and to investigate possible structural relationships between Mo and V. Mo XAS spectra for the glasses indicate isolated tetrahedral Mo6+O4 with Mo-O distances near 1.75 Å. V XANES indicate tetrahedral V5+O4 as the dominant species. Raman spectra show composition dependent trends, where Mo-O symmetrical stretch mode frequencies (ν1) are sensitive to the mix of alkali and alkaline earth cations, decreasing by up to 10 cm-1 for glasses that change from Li+ to Na+ as the dominant network-modifying species. This indicates that MoO4 tetrahedra are isolated from the borosilicate network and are surrounded, at least partly, by Na+ and Li+. Secondary ν1 frequency effects, with changes up to 7 cm-1, were also observed with increasing V2O5 and MoO3 content. These secondary trends may indicate MoO4-MoO4 and MoO4-VO4 clustering, suggesting that V additions may stabilize Mo in the matrix with respect to yellow phase formation.

Development of aluminosilicate and borosilicate glasses as matrices for CANDU high-level waste

International Nuclear Information System (INIS)

Strathdee, G.G.; McIntyre, N.S.; Taylor, P.

1979-01-01

This paper covers the results of analyses of two radioactive nepheline syenite glass blocks recovered from in-ground leaching experiments at the Chalk River Nuclear Laboratories. Current research on borosilicate glasses for immobilization of high-level waste is also described

Influence of Mo on the structure of borosilicate glass for the immobilization of high level waste

International Nuclear Information System (INIS)

Petrov, I.; Dimitriev, Y.; Kashchieva, E.

2015-01-01

It has been shown that the classic multi-borosilicate glass with concentration of MoO 3 has a low melting in the range of 1300 to 1400 ° C, but for achieving of complete homogenization and vitrification it is required temperature above 1400 ° C. Under this temperature in all tested samples areas of crystallization were observed, due to incomplete vitrification processes. It is understood that in all multicomponent borosilicate glass featuring MoO 3 , occur micro vitrification processes, and at a concentration of MoO 3 above 20% - macro segregation; It has been shown that the introduction of Nd in compound borosilicate glass featuring MoO 3 is observed crystallization of the phase Na 0.5 Nd 0.5 Mo, and it has been also found that the phase Na 0.5 Nd 0.5 Mo 4 can be synthesized either by solid phase reaction or supercooled melt. The results of surveys show that It is possible to prevent the occurrence of liquid phase separation in the studied multicomponent glass. From a structural point of view, the cause of liquid phase separation is the result of structural incompatibility of molybdenum units with structural units borosilicate network since not been established links Mo-O-B-O and Mo-Si. From a thermodynamic point of view in the lamination multi windows may be due to overlapping areas of delamination in component binary and triple systems. From the kinetic point of view of course the liquid phase by settling, and crystallization may be due to imbalances conditions the cooling process, in the course of which flow various processes of imbalances metastable settling, followed by crystallization of molybdate phases

Advances in understanding the structure of borosilicate glasses: A Raman spectroscopy study

Energy Technology Data Exchange (ETDEWEB)

Manara, D.; Grandjean, A. [CEA Marcoule, Serv Confinement Deches and Vitrificat, DTCD, DEN - 30 (France); Neuville, D.R. [Institut Physique Globe, Physique des Mineraux et Magmas, CNRS, F-75252 Paris 05 (France)

2009-05-15

This study is focused on the behavior of ternary SiO{sub 2}-Na{sub 2}O-B{sub 2}O{sub 3} borosilicate glasses at temperatures between 298 and 1800 K. Unpolarized Raman spectra were measured up to high temperature. SiO{sub 2}-Na{sub 2}O-B{sub 2}O{sub 3} glass samples were prepared with different values of the ratio R [Na{sub 2}O]/[B{sub 2}O{sub 3}], while the ratio K = [SiO{sub 2}]/[B{sub 2}O{sub 3}] was kept constant and equal 2.12. Spectra were measured at room temperature in samples with 0.43 {<=} R {<=} 1.68, and the effect of the modifier content was clearly observed in these glasses, only in partial agreement with previous literature results. In particular, the formation in the glass of sodium-danburite units Na{sub 2}O-B{sub 2}O{sub 3}-2SiO{sub 2} was postulated. This feature led to a new assessment of R{sup *}, the critical value of R above which every new alkali atom added to the system breaks a Fo-O-Fo (Fo=glass former) bridge causing depolymerization of the glass. A revised formula is proposed to obtain the value of R{sup *} as a function of K. Raman spectra measured at high temperature yielded important information about the temperature-dependent evolution of the borosilicate system. In particular, borate and borosilicate units including tetra-coordinated boron seem to be unstable at high temperature, where the formation of metaborate chains or rings is fostered. Above 1500 degrees C, evaporation of borate compounds is clearly observed, stemming from the small sample size. (authors)

Barium borosilicate glass - a potential matrix for immobilization of sulfate bearing high-level radioactive liquid waste

International Nuclear Information System (INIS)

Kaushik, C.P.; Mishra, R.K.; Sengupta, P.; Kumar, Amar; Das, D.; Kale, G.B.; Raj, Kanwar

2006-01-01

Borosilicate glass formulations adopted worldwide for immobilization of high-level radioactive liquid waste (HLW) is not suitable for sulphate bearing HLW, because of its low solubility in such glass. A suitable glass matrix based on barium borosilicate has been developed for immobilization of sulphate bearing HLW. Various compositions based on different glass formulations were made to examine compatibility with waste oxide with around 10 wt% sulfate content. The vitrified waste product obtained from barium borosilicate glass matrix was extensively evaluated for its characteristic properties like homogeneity, chemical durability, glass transition temperature, thermal conductivity, impact strength, etc. using appropriate techniques. Process parameters like melt viscosity and pour temperature were also determined. It is found that SB-44 glass composition (SiO 2 : 30.5 wt%, B 2 O 3 : 20.0 wt%, Na 2 O: 9.5 wt% and BaO: 19.0 wt%) can be safely loaded with 21 wt% waste oxide without any phase separation. The other product qualities of SB-44 waste glass are also found to be on a par with internationally adopted waste glass matrices. This formulation has been successfully implemented in plant scale

Chapter 1. The characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan. The chemical composition of danburite ore of Ak-Arkhar Deposit was defined. The chemical composition of danburite ore concentrate of Ak-Arkhar Deposit was defined as well.

Modelling the evaporation of boron species. Part 1: Alkali-free borosilicate glass melts

NARCIS (Netherlands)

Limpt, J.A.C. van; Beerkens, R.G.C.; Cook, S.; O'Connor, R.; Simon, J.

2011-01-01

A laboratory test facility has been used to measure the boron evaporation rates from borosilicate glass melts. The impact of furnace atmosphere composition and glass melt composition on the temperature dependent boron evaporation rates has been investigated experimentally. In Part 1 of this paper

Gas gain stability of MSGCs on borosilicate glass

International Nuclear Information System (INIS)

Berg, F.D. van den; Daum, C.; Eijk, B. van; Hartjes, F.G.; Udo, F.; Zhukov, V.

1996-01-01

The gas gain stability in Micro Strip Gas Counters fabricated on borosilicate glass has been investigated for operation at high radiation fluxes up to 10 5 Hz/mm 2 in a X-ray set-up. We discuss effects of short and long term irradiation on the gain for different voltage settings and strip metalisations. The application of a high drift field and a back plane on positive potential provides good high rate operation up to 10 4 Hz/mm 2 . Ageing is observed to be strongly dependent on the stirp metalisation; gold and nickel perform better than aluminium and copper. (orig.)

Development of borosilicate glass compositions for the immobilisation of the UK's separated plutonium stocks

International Nuclear Information System (INIS)

Harrison, M. T.; Scales, C. R.

2008-01-01

The UK inventory of separated civil plutonium is expected to exceed 100 tonnes by 2010. Whilst the majority of this could be used in the manufacture of MOx (Mixed Oxide) fuel in future power generation scenarios, options for the disposal of surplus plutonium are currently being investigated by Nexia Solutions Ltd on behalf of the UK's Nuclear Decommissioning Authority (NDA). One of the options being considered is immobilisation in a durable glass matrix followed by long term storage and subsequent final repository disposal. A preliminary experimental survey assessed a selection of potential glass systems on the basis of Pu-surrogate (cerium) loading, durability, and ease of processing. Following this, a number of borosilicate compositions have been taken forward into a more detailed investigation in order to fully qualify their potential for Pu-immobilisation. The selected compositions are lanthanide borosilicate (LaBS), alkali tin silicate (ATS) and high-lanthanide alkali borosilicate (modified-MW). For this second series of experiments, hafnium was selected as the Pu surrogate, and a study of the potential waste loading as a function of temperature for the three selected compositions is described in this paper. Furthermore, several variations of the LaBS composition were fabricated in order to investigate the effect of total lanthanide content on melting temperature. The benchmark of 10 wt% HfO 2 incorporation is achievable for all three glasses with temperatures of 1200, 1300 and 1400 deg. C required for ATS, modified-MW and LaBS respectively. (authors)

Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

Science.gov (United States)

Wananuruksawong, R.; Jinawath, S.; Padipatvuthikul, P.; Wasanapiarnpong, T.

2011-10-01

Silicon nitride (Si3N4) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si3N4 ceramic as a dental core material. The white Si3N4 was prepared by pressureless sintering at relative low sintering temperature of 1650 °C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si3N4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si3N4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (tube furnace between 1000-1200°C. The veneered specimens fired at 1100°C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98×10-6 °C-1, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

Characterization of borosilicate glasses containing simulated high-level radioactive wastes from PNC

International Nuclear Information System (INIS)

Terai, R.; Eguchi, K.; Yamanaka, H.

1979-01-01

The characterization of borosilicate glasses containing simulated HLW from PNC has been carried out. Phase separation of molybdates, volatilization, viscosity, electrical resistivity, thermal conductivity, elastic modulus, chemical durability, and devitrification of these glasses have been measured, and the suitability of the glasses for the vitrified solidification processes is discussed from the viewpoint of safety

X-ray tomography of feed-to-glass transition of simulated borosilicate waste glasses

Czech Academy of Sciences Publication Activity Database

Harris, W.H.; Guillen, D.P.; Kloužek, Jaroslav; Pokorný, P.; Yano, T.; Lee, S.; Schweiger, M. J.; Hrma, P.

2017-01-01

Roč. 100, č. 9 (2017), s. 3883-3894 ISSN 0002-7820 Institutional support: RVO:67985891 Keywords : borosilicate glass * computed tomography * glass melting * morphology * nuclear waste * X-ray Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass OBOR OECD: Ceramics Impact factor: 2.841, year: 2016

Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds.

Science.gov (United States)

Wang, Hui; Zhao, Shichang; Xiao, Wei; Xue, Jingzhe; Shen, Youqu; Zhou, Jie; Huang, Wenhai; Rahaman, Mohamed N; Zhang, Changqing; Wang, Deping

2016-01-01

Copper doped borosilicate glasses (BG-Cu) were studied by means of FT-IR, Raman, UV-vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B-O bond of BO4 groups at 980 cm(-1), while they decrease that of BO2O(-) groups at 1440-1470 cm(-1) as shown by Raman spectra. A negative shift was observed from (11)B and (29)Si NMR spectra. The (11)B NMR spectra exhibited a clear transformation from BO3 into BO4 groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG-Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of heat treatment duration on phase separation of sodium borosilicate glass, containing copper

International Nuclear Information System (INIS)

Shejnina, T.G.; Gutner, S.Kh.; Anan'in, N.I.

1989-01-01

The effect of heat treatment duration on phase separation of sodium borosilicate (SBS) glass, containing copper is studied. It is stated that phase separation close to equilibrium one is attained under 12 hours of heat treatment of SBS glass containing copper

X-ray absorption and Raman spectroscopy studies of molybdenum environments in borosilicate waste glasses

Energy Technology Data Exchange (ETDEWEB)

McKeown, David A., E-mail: davidm@vsl.cua.edu; Gan, Hao; Pegg, Ian L.

2017-05-15

Mo-containing high-level nuclear waste borosilicate glasses were investigated as part of an effort to improve Mo loading while avoiding yellow phase crystallization. Previous work showed that additions of vanadium decrease yellow phase formation and increases Mo solubility. X-ray absorption spectroscopy (XAS) and Raman spectroscopy were used to characterize Mo environments in HLW borosilicate glasses and to investigate possible structural relationships between Mo and V. Mo XAS spectra for the glasses indicate isolated tetrahedral Mo{sup 6+}O{sub 4} with Mo-O distances near 1.75 Å. V XANES indicate tetrahedral V{sup 5+}O{sub 4} as the dominant species. Raman spectra show composition dependent trends, where Mo-O symmetrical stretch mode frequencies (ν{sub 1}) are sensitive to the mix of alkali and alkaline earth cations, decreasing by up to 10 cm{sup −1} for glasses that change from Li{sup +} to Na{sup +} as the dominant network-modifying species. This indicates that MoO{sub 4} tetrahedra are isolated from the borosilicate network and are surrounded, at least partly, by Na{sup +} and Li{sup +}. Secondary ν{sub 1} frequency effects, with changes up to 7 cm{sup −1}, were also observed with increasing V{sub 2}O{sub 5} and MoO{sub 3} content. These secondary trends may indicate MoO{sub 4}-MoO{sub 4} and MoO{sub 4}-VO{sub 4} clustering, suggesting that V additions may stabilize Mo in the matrix with respect to yellow phase formation. - Highlights: •Raman and XAS data indicate isolated MoO{sub 4} tetrahedra from the borosilicate network. •Mo-O stretch frequency is sensitive to network-modifying Li and Na concentrations. •Mo-O stretch frequency shifts were also seen with increasing V{sub 2}O{sub 5} and MoO{sub 3} content. •The Raman trends may indicate MoO{sub 4}-MoO{sub 4} and MoO{sub 4}-VO{sub 4} clustering in the glass. •V may stabilize Mo in the glass matrix avoiding yellow phase formation.

The structure of leached sodium borosilicate glass

International Nuclear Information System (INIS)

Bunker, B.C.; Tallant, D.R.; Headley, T.J.; Turner, G.L.; Kirkpatrick, R.J.

1988-01-01

Raman spectroscopy, solid state 29 Si, 11 B, 17 O, and 23 Na nuclear magnetic resonance spectroscopy, and transmission electron microscopy have been used to investigate how the structures of sodium borosilicate glasses change during leaching in water at pH 1, 9, and 12. Results show that the random network structure present prior to leaching is transformed into a network of small condensed ring structures and/or colloidal silica particles. The restructuring of leached glass can be rationalised on the basis of simple hydrolysis (depolymerisation) and condensation (repolymerisation) reactions involving Si-O-Si and Si-O-B bonds. The structural changes that occur during leaching influence the properties of the leached layer, including leaching kinetics, crazing and spalling, and slow crack growth. (author)

Quantification of the boron speciation in alkali borosilicate glasses by electron energy loss spectroscopy

DEFF Research Database (Denmark)

Cheng, D.S.; Yang, G.; Zhao, Y.Q.

2015-01-01

developed a method based on electron energy loss spectroscopy (EELS) data acquisition and analyses, which enables determination of the boron speciation in a series of ternary alkali borosilicate glasses with constant molar ratios. A script for the fast acquisition of EELS has been designed, from which...

Performance of borosilicate glass, Synroc and spent fuel as nuclear waste forms

International Nuclear Information System (INIS)

Lutze, W.; Grambow, B.; Ewing, R.C.

1990-01-01

Presently, there are three prominent waste forms under consideration for the disposal of high-level waste: Borosilicate glass and Synroc for high-level radioactive waste from fuel reprocessing and spent fuel as the waste form for non-reprocessed fuel. Using the present experimental data base, one may compare the performance of these three waste forms under repository relevant conditions. In low water flow regimes and at temperatures less than 100 degree C, the fractional release rates of all three waste forms are low, on the order of 10-7/d or less and may decrease with time. Under these conditions the three waste forms behave similarly. At elevated temperatures or in high flow regimes, the durability of borosilicate glass will be much less than that of Synroc, and thus, for certain disposal schemes (e.g., deep burial) Synroc is preferable. All predictions of the long-term behavior are based on the extrapolation of short term experimental data, we point out that appropriate and useful natural analogues are available for each of these waste forms and should be used in the performance assessment of each waste form's long-term behavior. 14 refs

Magnetic Glass Ceramics by Sintering of Borosilicate Glass and Inorganic Waste

OpenAIRE

Ponsot, In?s M. M. M.; Pontikes, Yiannis; Baldi, Giovanni; Chinnam, Rama K.; Detsch, Rainer; Boccaccini, Aldo R.; Bernardo, Enrico

2014-01-01

Ceramics and glass ceramics based on industrial waste have been widely recognized as competitive products for building applications; however, there is a great potential for such materials with novel functionalities. In this paper, we discuss the development of magnetic sintered glass ceramics based on two iron-rich slags, coming from non-ferrous metallurgy and recycled borosilicate glass. The substantial viscous flow of the glass led to dense products for rapid treatments at relatively low te...

Differential response of DU145 and PC3 prostate cancer cells to ionizing radiation: role of reactive oxygen species, GSH and Nrf2 in radiosensitivity.

Science.gov (United States)

Jayakumar, Sundarraj; Kunwar, Amit; Sandur, Santosh K; Pandey, Badri N; Chaubey, Ramesh C

2014-01-01

Radioresistance is the major impediment in radiotherapy of many cancers including prostate cancer, necessitating the need to understand the factors contributing to radioresistance in tumor cells. In the present study, the role of cellular redox and redox sensitive transcription factor, Nrf2 in the radiosensitivity of prostate cancer cell lines PC3 and DU145, has been investigated. Differential radiosensitivity of PC3 and DU145 cells was assessed using clonogenic assay, flow cytometry, and comet assay. Their redox status was measured using DCFDA and DHR probes. Expression of Nrf2 and its dependent genes was measured by EMSA and real time PCR. Knockdown studies were done using shRNA transfection. PC3 and DU145 cells differed significantly in their radiosensitivity as observed by clonogenic survival, apoptosis and neutral comet assays. Both basal and inducible levels of ROS were higher in PC3 cells than that of DU145 cells. DU145 cells showed higher level of basal GSH content and GSH/GSSG ratio than that of PC3 cells. Further, significant increase in both basal and induced levels of Nrf2 and its dependent genes was observed in DU145 cells. Knock-down experiments and pharmacological intervention studies revealed the involvement of Nrf2 in differential radio-resistance of these cells. Cellular redox status and Nrf2 levels play a causal role in radio-resistance of prostate cancer cells. The pivotal role Nrf2 has been shown in the radioresistance of tumor cells and this study will further help in exploiting this factor in radiosensitization of other tumor cell types. © 2013.

Photon emission induced by brittle fracture of borosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Shiota, Tadashi, E-mail: tshiota@ceram.titech.ac.jp [Department of Metallurgy and Ceramic Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Sato, Yoshitaka [Department of Metallurgy and Ceramic Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Kishi, Tetsuo [Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Yasuda, Kouichi [Department of Metallurgy and Ceramic Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2016-05-15

Photon emission (PE) at wavelength ranges of 430–490 nm (B-PE), 500–600 nm (G-PE) and 610–680 nm (R-PE) caused by brittle fracture was simultaneously measured in the nanosecond-to-microsecond and millisecond time domains for two types of borosilicate glasses: Pyrex-type Tempax glass and BK7 glass. The results were compared to those for silica and soda lime glasses. The time dependence of the PE of Tempax glass was similar to that of silica glass, while the PE intensity was lower. Because Tempax glass contains both silica-rich and borate-rich amorphous phases, the PE must be mainly produced by the fracture of the silica-rich phase. Moreover, the proportion of B-PE of Tempax glass was higher than that of silica glass. This suggests that the measured B-PE might also include very weak PE caused by the fracture of the borate-rich phase. The PE time dependence of BK7 glass was similar to that of soda lime glass, which was different from the case for Tempax glass. The PE intensity of BK7 glass was slightly higher than that of soda lime glass, but much lower than that of Tempax glass. The result indicates that non-bridging oxygen in the glasses affects crack propagation behavior and reduces the PE. - Highlights: • Photon emission (PE) upon brittle fracture of borosilicate glasses was measured. • Pyrex-type Tempax and BK7 glasses showed different PE characteristics. • The rupture of Si–O bonds produces much stronger PE than that of B–O bonds. • Non-bridging oxygen in glass affects crack propagation behavior and reduces the PE.

Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

International Nuclear Information System (INIS)

Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T; Padipatvuthikul, P

2011-01-01

Silicon nitride (Si 3 N 4 ) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si 3 N 4 ceramic as a dental core material. The white Si 3 N 4 was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si 3 N 4 ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si 3 N 4 specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder ( 2 O 3 - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si 3 N 4 specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10 -6 deg. C -1 , rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

57Fe Moessbauer effect in borosilicate glasses

International Nuclear Information System (INIS)

Music, S.

1989-01-01

The present study was carried out to elucidate the valence state of iron and its co-ordination in borosilicate glasses, which are being investigated as possible solidification matrices for the immobilization of a simulated nuclear waste. 57 Fe Mossbauer spectroscopy was used as the experimental technique. The chemical compositions of glass samples and the experimental conditions for the preparation of these samples are given. Iron in the form of haematite (α-Fe 2 O 3 ) was used as doping material. Details of the experimental procedure have previously been described. Isomer shifts are calculated relative to α-iron. The results indicate a strong dependence of the valency of the iron and its coordination on the chemical composition of the glass and the Fe 2 O 3 content. The method of preparing the glasses also influences the state of the iron in oxide glasses. (Author)

Determination of occluded helium and oxygen in irradiated borosilicate glass samples

International Nuclear Information System (INIS)

Ramanjaneyulu, P.S.; Kulkarni, A.S.; Shrivastava, K.C.; Yadav, C.S.; Saxena, M.K.; Tomar, B.S.; Ramakumar, K.L.; Shah, J.G.

2015-01-01

Occluded gases in irradiated borosilicate glass were determined at 573, 873 and 1273 K for understanding the radiation damage in glass matrix. Hot vacuum extraction coupled with a quadrupole mass spectrometer technique was employed for the measurements. Relative sensitivity factors of various gases in QMS system were also determined and used for gas composition calculations. At 573 K only helium was found to get released whereas at 873 and 1273 K both helium and oxygen were released with major fraction of oxygen. (author)

Stress corrosion in a borosilicate glass nuclear wasteform

International Nuclear Information System (INIS)

Ringwood, A.E.; Willis, P.

1984-01-01

The authors discuss a typical borosilicate glass wasteform which, when exposed to water vapour and water for limited periods, exhibits evidence of stress corrosion cracking arising from the interaction of polar OH groups with stressed glass surfaces. Glass wasteforms may experience similar stress corrosion cracking when buried in a geological repository and exposed to groundwaters over an extended period. This would increase the effective surface areas available for leaching by groundwater and could decrease the lifetime of the wasteform. Conventional leach-testing methods are insensitive to the longer-term effects of stress corrosion cracking. It is suggested that specific fracture-mechanics tests designed to evaluate susceptibility to stress corrosion cracking should be used when evaluating the wasteforms for high-level nuclear wastes. (author)

Commercial Ion Exchange Resin Vitrification in Borosilicate Glass

International Nuclear Information System (INIS)

Cicero-Herman, C.A.; Workman, P.; Poole, K.; Erich, D.; Harden, J.

1998-05-01

Bench-scale studies were performed to determine the feasibility of vitrification treatment of six resins representative of those used in the commercial nuclear industry. Each resin was successfully immobilized using the same proprietary borosilicate glass formulation. Waste loadings varied from 38 to 70 g of resin/100 g of glass produced depending on the particular resin, with volume reductions of 28 percent to 68 percent. The bench-scale results were used to perform a melter demonstration with one of the resins at the Clemson Environmental Technologies Laboratory (CETL). The resin used was a weakly acidic meth acrylic cation exchange resin. The vitrification process utilized represented a approximately 64 percent volume reduction. Glass characterization, radionuclide retention, offgas analyses, and system compatibility results will be discussed in this paper

Studies on the accelerated chemical durability test and its impact on structural changes in borosilicate glass matrix

International Nuclear Information System (INIS)

Thorat, Vidya S.; Kadam, P.S.; Mishra, R.K.; Kumar, Amar; Kaushik, C.P.; Sudarsan, V.; Tyagi, A.K.

2015-01-01

Sodium borosilicate glass used for the immobilisation of high level nuclear waste with tentative compositions (SiO 2 ) 0.477 (B 2 O 3 ) 0.239 (Na 2 O) 0.170 (TiO 2 ) 0.02 )3 (CaO) 0.068 (Al 2 O 3 ) 0.023 was evaluated for its long term stability in the repository conditions where it may be exposed to high temperature and pressure. 29 Si MAS NMR studies have confirmed that, upon leaching, sodium borosilicate glass undergoes congruent crystallization leading to the formation of an aluminosilicate phase, Na 6 Al 6 Si 10 O 32 . Further the residual glass structure in the composite sample is identical with that of the un-leached glass. Boron structural units are unaffected in the glass compositions upon leaching

Influence of Cu doping in borosilicate bioactive glass and the properties of its derived scaffolds

Energy Technology Data Exchange (ETDEWEB)

Wang, Hui [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Zhao, Shichang [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Xiao, Wei [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Xue, Jingzhe [Department of Chemistry, Tongji University, Shanghai 200092 (China); Shen, Youqu [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhou, Jie; Huang, Wenhai [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China); Rahaman, Mohamed N. [Department of Materials Science and Engineering, and Center for Biomedical Science and Engineering, Missouri University of Science and Technology, Rolla, MO 65409-0340 (United States); Zhang, Changqing, E-mail: shzhangchangqing@163.com [Department of Orthopedic Surgery, Shanghai Sixth People' s Hospital, Shanghai Jiao Tong University, Shanghai 200233 (China); Wang, Deping, E-mail: wdpshk@tongji.edu.cn [School of Materials Science and Engineering, Tongji University, Shanghai 2001804 (China)

2016-01-01

Copper doped borosilicate glasses (BG–Cu) were studied by means of FT-IR, Raman, UV–vis and NMR spectroscopies to investigate the changes that appeared in the structure of borosilicate glass matrix by doping copper ions. Micro-fil and immunohistochemistry analysis were applied to study the angiogenesis of its derived scaffolds in vivo. Results indicated that the Cu ions significantly increased the B–O bond of BO{sub 4} groups at 980 cm{sup −1}, while they decrease that of BO{sub 2}O{sup −} groups at 1440–1470 cm{sup −1} as shown by Raman spectra. A negative shift was observed from {sup 11}B and {sup 29}Si NMR spectra. The {sup 11}B NMR spectra exhibited a clear transformation from BO{sub 3} into BO{sub 4} groups, caused by the agglutination effect of the Cu ions and the charge balance of the agglomerate in the glass network, leading to a more stable glass network and lower ions release rate in the degradation process. Furthermore, the BG–Cu scaffolds significantly enhanced blood vessel formation in rat calvarial defects at 8 weeks post-implantation. Generally, it suggested that the introduction of Cu into borosilicate glass endowed glass and its derived scaffolds with good properties, and the cooperation of Cu with bioactive glass may pave a new way for tissue engineering. - Highlights: • Agglutination effect of Cu{sup 2+} and charge balance of agglomerate lead to more stable glass. • Lower degradability and lower ions release were found in BG-Cu scaffolds. • Excellent angiogenesis and sustain Cu{sup 2+} release were endowed by doping Cu.

There Is Still Room for Improvement: Presentation of a Neutral Borosilicate Glass with Improved Chemical Stability for Parenteral Packaging.

Science.gov (United States)

Boltres, Bettine; Tratzky, Stephan; Kass, Christof; Eichholz, Rainer; Naß, Peter

2016-01-01

For pharmaceutical parenteral packaging the glass compositions have always been either Type I borosilicate or Type III soda-lime glass. As both the compositions and certain chemical and physical properties are mandated by international standards, there has not been room for any changes. However, by applying only minor adjustments, a borosilicate glass was developed that showed improved chemical stability. The chemical composition is still in the range of currently used borosilicate glasses, which makes it a Type I glass according to all current pharmacopeia. A study was performed on glass vials comparing the new glass with the standard FIOLAX(®) and two other publicly available glasses. In an extraction study with water at 121 °C the new glass showed the highest chemical stability with the lowest amount of extractables. In an accelerated ageing study, which was done with water, phosphate, and carbonate buffer at 40 °C for 12 months, the new glass also proved to have the lowest amount of leachables. In this article the new glass and the results from the studies are presented, showing the reader how much of an effect can be attained with only minor adjustments if the scientific fundamentals are clear. The pharmaceutical market has been quite constant and risk-oriented due to the high impact on the safety of the patient. As any change necessitates a complicated change process, this has, in consequence, lead the industry to resist changing the parenteral primary packaging material for decades. The main glasses have either been Type I borosilicate or Type III soda-lime glass. On the other hand, a combination of improved inspection systems and the development of more sensitive biologically based drugs has elevated the standards for parental packaging materials. For example, the measurement of extractables and leachables from the packaging material steadily came into focus. In this article, a new glass is presented that still belongs to the group of Type I borosilicate

Electron irradiation effect on bubble formation and growth in a sodium borosilicate glass

International Nuclear Information System (INIS)

Chen, X.; Birtcher, R. C.; Donnelly, S. E.

2000-01-01

In this study, the authors studied simultaneous and intermittent electron irradiation effects on bubble growth in a simple sodium borosilicate glass during Xe ion implantation at 200 C. Simultaneous electron irradiation increases the average bubble size in the glass. This enhanced diffusion is also shown by the migration of Xe from bubbles into the matrix when the sample is irradiated by an electron beam after the Xe implantation

Understanding the structural drivers governing glass-water interactions in borosilicate based model bioactive glasses.

Science.gov (United States)

Stone-Weiss, Nicholas; Pierce, Eric M; Youngman, Randall E; Gulbiten, Ozgur; Smith, Nicholas J; Du, Jincheng; Goel, Ashutosh

2018-01-01

The past decade has witnessed a significant upsurge in the development of borate and borosilicate based resorbable bioactive glasses owing to their faster degradation rate in comparison to their silicate counterparts. However, due to our lack of understanding about the fundamental science governing the aqueous corrosion of these glasses, most of the borate/borosilicate based bioactive glasses reported in the literature have been designed by "trial-and-error" approach. With an ever-increasing demand for their application in treating a broad spectrum of non-skeletal health problems, it is becoming increasingly difficult to design advanced glass formulations using the same conventional approach. Therefore, a paradigm shift from the "trial-and-error" approach to "materials-by-design" approach is required to develop new-generations of bioactive glasses with controlled release of functional ions tailored for specific patients and disease states, whereby material functions and properties can be predicted from first principles. Realizing this goal, however, requires a thorough understanding of the complex sequence of reactions that control the dissolution kinetics of bioactive glasses and the structural drivers that govern them. While there is a considerable amount of literature published on chemical dissolution behavior and apatite-forming ability of potentially bioactive glasses, the majority of this literature has been produced on silicate glass chemistries using different experimental and measurement protocols. It follows that inter-comparison of different datasets reveals inconsistencies between experimental groups. There are also some major experimental challenges or choices that need to be carefully navigated to unearth the mechanisms governing the chemical degradation behavior and kinetics of boron-containing bioactive glasses, and to accurately determine the composition-structure-property relationships. In order to address these challenges, a simplified

The origin of cholesterol in chyle demonstrated by nuclear indicator methods; Origines du cholesterol du chyle mises en evidence par la methode des indicateurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Vyas, M

1962-07-01

In order to obtain information about the mechanism of the intestinal absorption of cholesterol, rats having a lymphatic abdominal fistula are used. The animals receive either 4-{sup 14}C- cholesterol subcutaneously or orally, or the 1-{sup 14}C acetate. The study of the specific radio-activities of the cholesterol in chyle, in serum, in the lining, and in the intestinal contents makes it possible to define the roles played by the transfer cholesterol from the serum, by the cholesterol synthesised intestinally, and by the absorption cholesterol, in the formations of the lymph and of the chylomicrons. A new theory is proposed for the mechanism of cholesterol absorption. (author) [French] Pour obtenir des renseignements concernant le mecanisme de l'absorption intestinale du cholesterol, on utilise des rats porteurs d'une fistule lymphatique abdominale. Les animaux recoivent soit du cholesterol 4-{sup 14}C par voie sous-cutanee ou par voie orale, soit de l'acetate 1-{sup 14}C. L'etude des radioactivites specifiques du cholesterol du chyle, du serum, de la paroi et du contenu intestinal permet de preciser les roles joues par le cholesterol de transfert d'origine serique, par le cholesterol de synthese intestinale et par le cholesterol d'absorption, dans la formation de la lymphe et des chylomicrons. Une theorie nouvelle concernant le mecanisme de l'absorption du cholesterol est proposee. (auteur)

High-level waste glass compendium; what it tells us concerning the durability of borosilicate waste glass

International Nuclear Information System (INIS)

Cunnane, J.C.; Allison, J.

1993-01-01

Facilities for vitrification of high-level nuclear waste in the United States are scheduled for startup in the next few years. It is, therefore, appropriate to examine the current scientific basis for understanding the corrosion of high-level waste borosilicate glass for the range of service conditions to which the glass products from these facilities may be exposed. To this end, a document has been prepared which compiles worldwide information on borosilicate waste glass corrosion. Based on the content of this document, the acceptability of canistered waste glass for geological disposal is addressed. Waste glass corrosion in a geologic repository may be due to groundwater and/or water vapor contact. The important processes that determine the glass corrosion kinetics under these conditions are discussed based on experimental evidence from laboratory testing. Testing data together with understanding of the long-term corrosion kinetics are used to estimate radionuclide release rates. These rates are discussed in terms of regulatory performance standards

Viscosity of melts in the sodium borosilicate system

International Nuclear Information System (INIS)

Tait, J.C.; Mandolesi, D.L.; Rummens, H.E.C.

1984-01-01

The viscosities of a series of glasses in the sodium borosilicate system (5-35Na 2 O, 5-35B 2 O 3 , 45-80SiO 2 mol%) have been determined between 950 and 1500 deg C, using a rotating bob viscometer. A simplex lattice experimental design was used to define a series of compositions suitable for numerical analysis of the data. The viscosity data were fitted using the Fulcher equation for each composition. Nonlinear regression analysis of the viscosities at constant temperatures gave expressions for the variation in viscosity as a function of composition. The results are displayed as isoviscosity contours on the Na 2 O-B 2 O 3 -SiO 2 composition diagram. The viscosity behaviour as a function of composition is discussed in terms of structural bonding in the melt. (author)

The Dissolution Behavior of Borosilicate Glasses in Far-From Equilibrium Conditions

Energy Technology Data Exchange (ETDEWEB)

Neeway, James J.; Rieke, Peter C.; Parruzot, Benjamin PG; Ryan, Joseph V.; Asmussen, Robert M.

2018-02-10

In far-from-equilibrium conditions, the dissolution of borosilicate glasses used to immobilize nuclear waste is known to be a function of both temperature and pH. The aim of this paper is to study effects of these variables on three model waste glasses (SON68, ISG, AFCI). To do this, experiments were conducted at temperatures of 23, 40, 70, and 90 °C and pH(RT) values of 9, 10, 11, and 12 with the single-pass flow-through (SPFT) test method. The results from these tests were then used to parameterize a kinetic rate model based on transition state theory. Both the absolute dissolution rates and the rate model parameters are compared with previous results. Discrepancies in the absolute dissolution rates as compared to those obtained using other test methods are discussed. Rate model parameters for the three glasses studied here are nearly equivalent within error and in relative agreement with previous studies. The results were analyzed with a linear multivariate regression (LMR) and a nonlinear multivariate regression performed with the use of the Glass Corrosion Modeling Tool (GCMT), which is capable of providing a robust uncertainty analysis. This robust analysis highlights the high degree of correlation of various parameters in the kinetic rate model. As more data are obtained on borosilicate glasses with varying compositions, the effect of glass composition on the rate parameter values could possibly be obtained. This would allow for the possibility of predicting the forward dissolution rate of glass based solely on composition

Fabrication of Silicon Nitride Dental Core Ceramics with Borosilicate Veneering material

Energy Technology Data Exchange (ETDEWEB)

Wananuruksawong, R; Jinawath, S; Wasanapiarnpong, T [Research Unit of Advanced Ceramic, Department of Materials Science, Faculty of Science, Chulalongkorn University, Bangkok (Thailand); Padipatvuthikul, P, E-mail: raayaa_chula@hotmail.com [Faculty of Dentistry, Srinakharinwirot University, Bangkok (Thailand)

2011-10-29

Silicon nitride (Si{sub 3}N{sub 4}) ceramic is a great candidate for clinical applications due to its high fracture toughness, strength, hardness and bio-inertness. This study has focused on the Si{sub 3}N{sub 4} ceramic as a dental core material. The white Si{sub 3}N{sub 4} was prepared by pressureless sintering at relative low sintering temperature of 1650 deg. C in nitrogen atmosphere. The coefficient of thermal expansion (CTE) of Si{sub 3}N{sub 4} ceramic is lower than that of Zirconia and Alumina ceramic which are popular in this field. The borosilicate glass veneering was employed due to its compatibility in thermal expansion. The sintered Si{sub 3}N{sub 4} specimens represented the synthetic dental core were paintbrush coated by a veneer paste composed of borosilicate glass powder (<150 micrometer, Pyrex) with 5 wt% of zirconia powder (3 wt% Y{sub 2}O{sub 3} - partial stabilized zirconia) and 30 wt% of polyvinyl alcohol (5 wt% solution). After coating the veneer on the Si{sub 3}N{sub 4} specimens, the firing was performed in electric tube furnace between 1000-1200 deg. C. The veneered specimens fired at 1100 deg. C for 15 mins show good bonding, smooth and glossy without defect and crazing. The veneer has thermal expansion coefficient as 3.98x10{sup -6} deg. C{sup -1}, rather white and semi opaque, due to zirconia addition, the Vickers hardness as 4.0 GPa which is closely to the human teeth.

Intrinsic dosimetry. Properties and mechanisms of thermoluminescence in commercial borosilicate glass

Energy Technology Data Exchange (ETDEWEB)

Clark, Richard A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2012-10-01

Intrinsic dosimetry is the method of measuring total absorbed dose received by the walls of a container holding radioactive material. By considering the total absorbed dose received by a container in tandem with the physical characteristics of the radioactive material housed within that container, this method has the potential to provide enhanced pathway information regarding the history of the container and its radioactive contents. The latest in a series of experiments designed to validate and demonstrate this newly developed tool are reported. Thermoluminescence (TL) dosimetry was used to measure dose effects on raw stock borosilicate container glass up to 70 days after gamma ray, x-ray, beta particle or ultraviolet irradiations at doses from 0.15 to 20 Gy. The TL glow curve when irradiated with 60Co was separated into five peaks: two relatively unstable peaks centered near 120 and 165°C, and three relatively stable peaks centered near 225, 285, and 360°C. Depending on the borosilicate glass source, the minimum measurable dose using this technique is 0.15-0.5 Gy, which is roughly equivalent to a 24 hr irradiation at 1 cm from a 50-165 ng source of 60Co. Differences in TL glow curve shape and intensity were observed for the glasses from different geographical origins. These differences can be explained by changes in the intensities of the five peaks. Electron paramagnetic resonance (EPR) and multivariate statistical methods were used to relate the TL intensity and peaks to electron/hole traps and compositional variations.

Activation and transfer of sulfate in biological systems (1960); Activation biologique du sulfate et son transfert (1960)

Energy Technology Data Exchange (ETDEWEB)

Chapeville, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

It examines in this review the successive stages of active sulfate formation and its role in biological synthesis of sulfuric esters. The possible role of active sulfate as intermediary in sulfate reduction is also discussed. (author) [French] On examine dans cette etude les stades successifs de la mise en evidence du sulfate actif, son role dans la formation des esters sulfuriques de natures diverses, ainsi que sa participation eventuelle comme intermediaire au cours de la reduction du sulfate. On decrit aussi un procede de preparation du systeme biologique, generateur du sulfate actif et une methode de synthese chimique. (auteur)

Effects of alpha radiation on hardness and toughness of the borosilicate glass applied to radioactive wastes immobilization

International Nuclear Information System (INIS)

Prado, Miguel Oscar; Bernasconi, Norma B. Messi de; Bevilacqua, Arturo Miguel; Arribere, Maria Angelica; Heredia, Arturo D.; Sanfilippo, Miguel

1999-01-01

Borosilicate german glass SG7 samples, obtained by frit sintering, were irradiated with different fluences of thermal neutrons in the nucleus of a nuclear reactor. The nuclear reaction 10 B(n,α) 7 Li, where the 10 B isotope is one of the natural glass components, was used to generate alpha particles throughout the glass volume. The maximum alpha disintegration per unit volume achieved was equivalent to that accumulated in a borosilicate glass with nuclear wastes after 3.8 million years. Through Vickers indentations values for microhardness, stress for 50% fracture probability (Weibull statistics) and estimation of the toughness were obtained as a function of alpha radiation dose. Two counterbalanced effects were found: that due to the disorder created by the alpha particles in the glass and that due to the annealing during irradiation (temperature below 240 deg C). Considering the alpha radiation effect, glasses tend decrease Vickers hardness, and to increase thr 50% fracture probability stress with the dose increase. (author)

Dielectric behaviour of (Ba,Sr)TiO3 perovskite borosilicate glass ceramics

International Nuclear Information System (INIS)

Yadav, Avadhesh Kumar; Gautam, C.R.

2013-01-01

Various perovskite (Ba,Sr)TiO 3 borosilicate glasses were prepared by rapid melt-quench technique in the glass system ((Ba 1-x Sr x ).TiO 3 )-(2SiO 2 .B 2 O 3 )-(K 2 O)-(La 2 O 3 ). On the basis of differential thermal analysis results, glasses were converted into glass ceramic samples by regulated heat treatment schedules. The dielectric behaviour of crystallized barium strontium titanate borosilicate glass ceramic samples shows diffuse phase transition. The study depicts the dielectric behaviour of glass ceramic sample BST5K1L0.2S814. The double relaxation was observed in glass ceramic samples corresponding 80/20% Ba/Sr due to change in crystal structure from orthorhombic to tetragonal and tetragonal to cubic with variation of temperature. The highest value of dielectric constant was found to be 48289 for the glass ceramic sample BST5K1L0.2S814. The high value of dielectric constant attributed to space charge polarization between the glassy phase and perovskite phase. Due to very high value of dielectric constant, such glass ceramics are used for high energy storage devices. La 2 O 3 acts as nucleating agent for crystallization of glass to glass ceramics and enhances the dielectric constant and retarded dielectric loss. Such glass ceramics can be used in high energy storage devices such as barrier layer capacitors, multilayer capacitors etc. (author)

Actes des 5èmes Journées Scientifiques du GDR3544 Sciences du Bois. Journées Annuelles du GDR 3544 Sciences du Bois

OpenAIRE

CHAPLAIN, Myriam; CARE, Sabine; GRIL, Joseph

2016-01-01

Le Groupement de Recherche en Sciences du bois (GDR3544 Sciences du Bois) a été créé en 2012 par le CNRS et renouvelé en 2016 pour 5 ans. La mission de ce groupement est : (1) de structurer la recherche sur le bois en France pour lui donner une visibilité nationale, (2) de contribuer au développement de la formation en sciences du bois et (3) de servir de relai aux réseaux internationaux de sciences du bois. Les 5èmes journées annuelles du GDR Bois ont été organisées à Bordeaux, au domaine du...

High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 3

International Nuclear Information System (INIS)

Cunnane, J.C.

1994-03-01

The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II

Influence of iron ions on the structural properties of Zn-borosilicate glasses

International Nuclear Information System (INIS)

Music, S.; Gotic, M.; Popovic, S.

1989-01-01

The objectives of this study were to determine the influence of iron ions on the appearance of crystalline phases in Zn-borosilicate glasses, and to obtain information about valence state and coordination of iron ions. The systems Na 2 O-ZnO-B 2 O 3 -SiO 2 and ZnO-B 2 O 3 -SiO 2 were doped with α-Fe 2 O 3 . X-ray diffraction, IR spectroscopy and 57 Fe Moessbauer spectroscopy were used as experimental techniques. (author) 32 refs.; 5 figs.; 5 tabs

High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 3

Energy Technology Data Exchange (ETDEWEB)

Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)] [and others

1994-03-01

The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II.

Electron irradiation induced nanocrystal formation in Cu-borosilicate glass

Energy Technology Data Exchange (ETDEWEB)

Sabri, Mohammed Mohammed; Möbus, Günter, E-mail: g.moebus@sheffield.ac.uk [University of Sheffield, Department of Materials Science and Engineering (United Kingdom)

2016-03-15

Nanoscale writing of Cu nanoparticles in glasses is introduced using focused electron irradiation by transmission electron microscopy. Two types of copper borosilicate glasses, one with high and another with low Cu loading, have been tested at energies of 200–300 keV, and formation of Cu nanoparticles in a variety of shapes and sizes using different irradiation conditions is achieved. Electron energy loss spectroscopy analysis, combined with high-resolution transmission electron microscopy imaging, confirmed the irradiation-induced precipitated nanoparticles as metallic, while furnace annealing of the glass triggered dendrite-shaped particles of copper oxide. Unusual patterns of nanoparticle rings and chains under focused electron beam irradiation are also presented. Conclusively, electron beam patterning of Cu-loaded glasses is a promising alternative route to well-established femtosecond laser photoreduction of Cu ions in glass.

Effets de la microdose sur la production du niébé, du mil et du ...

African Journals Online (AJOL)

Effets de la microdose sur la production du niébé, du mil et du sorgho en fonction la toposéquence. Fatimata Saba, Sibiri Jean Baptiste Taonda, Idriss Serme, Alimata A. Bandaogo, Augustin P. Sourwema, Adama Kabre ...

Method of manufacturing borosilicate glass solidification products

International Nuclear Information System (INIS)

Tanaka, Tsuneya.

1986-01-01

Purpose: To obtain glass solidification products efficiently in a dry process from medium and high level radioactive liquid wastes discharged from PWR type reactors. Method: Boric acid-containing radioactive liquid wastes generated from primary coolants of PWR type reactors are evaporated to condensate as the pre-treatment. The concentrated liquid wastes are supplied to a drum type rotary kiln. While on the other hand, usual glass frits are introduced into the kiln. The liquid wastes are dried in the rotary kiln, as well as B 2 O 3 and the glass frits in the liquid wastes are combined into glass particles. In this case, since the kiln is rotated, no glass particles are deposited on the wall of the kiln. Then, the glass particles are introduced for melting into a high frequency melting furnace made of metal. The melting temperature is set to 1100 - 1150 deg C. The molten borosilicate glass is recovered from the bottom of the melting furance, contained in a canister and cooled for several hours, and then a cover is welded to the canister. (Ikeda, J.)

Surface chemistry and durability of borosilicate glass

International Nuclear Information System (INIS)

Carroll, S.A.; Bourcier, W.L.; Phillips, B.L.

1994-01-01

Important glass-water interactions are poorly understood for borosilicate glass radioactive waste forms. Preliminary results show that glass durability is dependent on reactions occurring at the glass-solution interface. CSG glass (18.2 wt. % Na 2 O, 5.97 wt. % CaO, 11.68 wt. % Al 2 O 3 , 8.43 wt. % B 2 O 3 , and 55.73 wt. % SiO 2 ) dissolution and net surface H + and OH - adsorption are minimal at near neutral pH. In the acid and alkaline pH regions, CSG glass dissolution rates are proportional to [H + ] adsorbed 2 and [OH - ] adsorbed 0.8 , respectively. In contrast, silica gel dissolution and net H + and OH - adsorption are minimal and independent of pH in acid to neutral solutions. In the alkaline pH region, silica gel dissolution is proportional to [OH - ] adsorbed 0.9 adsorbed . Although Na adsorption is significant for CSG glass and silica gel in the alkaline pH regions, it is not clear if it enhances dissolution, or is an artifact of depolymerization of the framework bonds

L'administration du travail et la production du droit du travail (1906-1960). : Note de synthèse du rapport de recherche

OpenAIRE

Le Crom , Jean-Pierre

2007-01-01

Synthèse d'un rapport de recherche dont l'objectif est d'appréhender le rôle de l'administration centrale du travail dans la production du droit du travail. Deux dimensions sont explorées : le profil des rédacteurs et l'organisation des structures.

RHENIUM SOLUBILITY IN BOROSILICATE NUCLEAR WASTE GLASS IMPLICATIONS FOR THE PROCESSING AND IMMOBILIZATION OF TECHNETIUM-99 (AND SUPPORTING INFORMATION WITH GRAPHICAL ABSTRACT)

Energy Technology Data Exchange (ETDEWEB)

AA KRUGER; A GOEL; CP RODRIGUEZ; JS MCCLOY; MJ SCHWEIGER; WW LUKENS; JR, BJ RILEY; D KIM; M LIEZERS; P HRMA

2012-08-13

The immobilization of 99Tc in a suitable host matrix has proved a challenging task for researchers in the nuclear waste community around the world. At the Hanford site in Washington State in the U.S., the total amount of 99Tc in low-activity waste (LAW) is {approx} 1,300 kg and the current strategy is to immobilize the 99Tc in borosilicate glass with vitrification. In this context, the present article reports on the solubility and retention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW sodium borosilicate glass. Due to the radioactive nature of technetium, rhenium was chosen as a simulant because of previously established similarities in ionic radii and other chemical aspects. The glasses containing target Re concentrations varying from 0 to10,000 ppm by mass were synthesized in vacuum-sealed quartz ampoules to minimize the loss of Re by volatilization during melting at 1000 DC. The rhenium was found to be present predominantly as Re7 + in all the glasses as observed by X-ray absorption near-edge structure (XANES). The solubility of Re in borosilicate glasses was determined to be {approx}3,000 ppm (by mass) using inductively coupled plasma-optical emission spectroscopy (ICP-OES). At higher rhenium concentrations, some additional material was retained in the glasses in the form of alkali perrhenate crystalline inclusions detected by X-ray diffraction (XRD) and laser ablation-ICP mass spectrometry (LA-ICP-MS). Assuming justifiably substantial similarities between Re7 + and Tc 7+ behavior in this glass system, these results implied that the processing and immobilization of 99Tc from radioactive wastes should not be limited by the solubility of 99Tc in borosilicate LAW glasses.

Effet du Pediococcus acidilactici sur le bilan lipidique sanguin du ...

African Journals Online (AJOL)

Les résultats relatifs aux performances zootechniques ont montré que l'addition du probiotique a amélioré significativement le gain de poids pendant la phase de croissance se traduisant par un indice de consommation meilleur. Les dosages du cholestérol total, des triglycérides, du HDL et du LDL ont été déterminés à la ...

New insight into nanoparticle precipitation by electron beams in borosilicate glasses

Science.gov (United States)

Sabri, M. M.; Möbus, G.

2017-06-01

Nanoprecipitation in different oxide glasses by means of electron irradiation in transmission electron microscopy (TEM) has been compared in this study. Upon irradiation, groups or patterns of nanoparticles with various morphologies and sizes were formed in borosilicate glasses, loaded with zinc, copper, and silver. The study successfully includes loading ranges for the target metal from doping level (1%) over medium level (20%) to majority phase (60%). It is found that particle patterning resolution is affected by parallel processes of amorphous phase separation, glass ablation, and delocalised precipitation. In addition, via an in-situ study, it is confirmed that by heating alone without irradiation, no precipitate nanoparticles form.

New insight into nanoparticle precipitation by electron beams in borosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Sabri, M.M.; Moebus, G. [University of Sheffield, Department of Materials Science and Engineering (United Kingdom)

2017-06-15

Nanoprecipitation in different oxide glasses by means of electron irradiation in transmission electron microscopy (TEM) has been compared in this study. Upon irradiation, groups or patterns of nanoparticles with various morphologies and sizes were formed in borosilicate glasses, loaded with zinc, copper, and silver. The study successfully includes loading ranges for the target metal from doping level (1%) over medium level (20%) to majority phase (60%). It is found that particle patterning resolution is affected by parallel processes of amorphous phase separation, glass ablation, and delocalised precipitation. In addition, via an in-situ study, it is confirmed that by heating alone without irradiation, no precipitate nanoparticles form. (orig.)

Diffusion of cesium in sodium-borosilicate glasses for nuclear waste immobilisation. Diffusie van cesium in natrium borosilicaat glazen voor het immobiliseren van radioaktief afval

Energy Technology Data Exchange (ETDEWEB)

Janssen, F.J.J.G.; Sengers, E.G.F. (Keuring van Electrotechnische Materialen NV, Arnhem (Netherlands)); Waal, H. de (TPD-TNO-Glass technology, Eindhoven (Netherlands))

1989-09-26

Diffusion of cesium in borosilicate glass for high-level radioactive waste is discussed. For this purpose model glasses with non-radioactive elements are being made, in accordance with the specifications of the reprocessing plants, from which concentration couples are composed. A concentration couple consists of two cylinders of borosilicate glass which contain different amounts of cesium. After heat treatment the couples are studied by means of the scanning electron microscopy and X-ray microanalysis. The model study will provide a basis for predictions of the containment achieved over a longer period of time. (author). 11 refs.; 2 figs.; 2 tabs.

Gamma ray shielding study of barium-bismuth-borosilicate glasses as transparent shielding materials using MCNP-4C code, XCOM program, and available experimental data

Energy Technology Data Exchange (ETDEWEB)

Bagheri, Reza; Yousefinia, Hassan [Nuclear Fuel Cycle Research School (NFCRS), Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran, Tehran (Iran, Islamic Republic of); Moghaddam, Alireza Khorrami [Radiology Department, Paramedical Faculty, Mazandaran University of Medical Sciences, Sari (Iran, Islamic Republic of)

2017-02-15

In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and 10th value layer values of barium-bismuth-borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium-bismuth-borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

Alimentation du nouveau-ne et du nourrisson dans la region ...

African Journals Online (AJOL)

Alimentation du nouveau-ne et du nourrisson dans la region centrale du togo : pratiques familiales et communautaires avant la mise en oeuvre de la strategie « prise en charge integree des maladies de l'enfant »

Portage vaginal du streptocoque du groupe B chez la femme ...

African Journals Online (AJOL)

Introduction: le streptocoque du groupe B est le principal agent impliqué dans les infections materno-fœtales, les septicémies et les méningites du nouveau-né à terme. L'objectif est de déterminer le taux de portage maternel du streptocoque du groupe B (SGB) à terme. Méthodes: un prélèvement vaginal a été réalisé de ...

Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte-Carlo

Energy Technology Data Exchange (ETDEWEB)

Ledieu, A

2004-10-01

This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte Carlo

Energy Technology Data Exchange (ETDEWEB)

Ledieu, A

2004-10-15

This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

Rhenium solubility in borosilicate nuclear waste glass: implications for the processing and immobilization of technetium-99.

Science.gov (United States)

McCloy, John S; Riley, Brian J; Goel, Ashutosh; Liezers, Martin; Schweiger, Michael J; Rodriguez, Carmen P; Hrma, Pavel; Kim, Dong-Sang; Lukens, Wayne W; Kruger, Albert A

2012-11-20

The immobilization of technetium-99 ((99)Tc) in a suitable host matrix has proven to be a challenging task for researchers in the nuclear waste community around the world. In this context, the present work reports on the solubility and retention of rhenium, a nonradioactive surrogate for (99)Tc, in a sodium borosilicate glass. Glasses containing target Re concentrations from 0 to 10,000 ppm [by mass, added as KReO(4) (Re(7+))] were synthesized in vacuum-sealed quartz ampules to minimize the loss of Re from volatilization during melting at 1000 °C. The rhenium was found as Re(7+) in all of the glasses as observed by X-ray absorption near-edge structure. The solubility of Re in borosilicate glasses was determined to be ~3000 ppm (by mass) using inductively coupled plasma optical emission spectroscopy. At higher rhenium concentrations, additional rhenium was retained in the glasses as crystalline inclusions of alkali perrhenates detected with X-ray diffraction. Since (99)Tc concentrations in a glass waste form are predicted to be wastes, assuming Tc as Tc(7+) and similarities between Re(7+) and Tc(7+) behavior in this glass system.

Le ministre du Commerce international du Canada rencontre des ...

International Development Research Centre (IDRC) Digital Library (Canada)

17 juil. 2017 ... La promotion de l'entrepreneuriat, la façon dont le commerce peut profiter aux femmes et à leur famille, et la création d'emplois pour les plus vulnérables étaient au coeur de la discussion en table ronde du ministre du Commerce international du Canada, l'honorable François-Philippe Champagne, et des ...

Gamma Ray Shielding Study of Barium–Bismuth–Borosilicate Glasses as Transparent Shielding Materials using MCNP-4C Code, XCOM Program, and Available Experimental Data

Directory of Open Access Journals (Sweden)

Reza Bagheri

2017-02-01

Full Text Available In this work, linear and mass attenuation coefficients, effective atomic number and electron density, mean free paths, and half value layer and 10th value layer values of barium–bismuth–borosilicate glasses were obtained for 662 keV, 1,173 keV, and 1,332 keV gamma ray energies using MCNP-4C code and XCOM program. Then obtained data were compared with available experimental data. The MCNP-4C code and XCOM program results were in good agreement with the experimental data. Barium–bismuth–borosilicate glasses have good gamma ray shielding properties from the shielding point of view.

Energy transfer and cross-relaxation in Tb3+-doped borosilicate glasses

International Nuclear Information System (INIS)

Kim, Jung Hwan; Sol, Jung Sik

1990-01-01

Energy transfer in Tb 3+ -doped borosilicate glasses has been studied by the analysis of fluorescence intensities and lifetimes of 5 D 3 and 5 D 4 states as a function of Tb 3+ concentration. It is shown that as the Tb 3+ concentration is increased the cross-relaxation produces high population of the 5 D 4 state at the expense of 5 D 3 . It is also found that this interaction is predominantly dipole-dipole transition with critical distance of 13 A. The critical distance for energy transfer 5 D 4 5 D 3 which is responsible for the quenching of 5 D 4 emission at high concentration of Tb 3+ ions is 4.5 A. (Author)

Effect of ThO2 concentration on thermo-physical properties of barium borosilicate glass

International Nuclear Information System (INIS)

Mishra, R.K.; Munshi, A.K.; Kaushik, C.P.; Raj, Kanwar; Shobha, M.; Srikhande, V.K.; Kothiyal, G.P.; Tyagi, A.K.

2006-01-01

An advanced heavy water reactor is being developed at Bhabha Atomic Research Centre (BARC) India with an aim of utilizing thorium for power generation. The high level radioactive liquid waste (HLW) generated from reprocessing of Th-based spent fuel is expected to contain Th as one of the main constituents other than fission products, corrosion products, actinides and added chemicals. Barium borosilicate (BBS) glass is being used for vitrification of the HLW generated at the reprocessing plant at BARC, Trombay, Mumbai

Comparaison du filtre adaptatif RIF et du filtre a base de reseau de ...

African Journals Online (AJOL)

Comparaison du filtre adaptatif RIF et du filtre a base de reseau de neurones pour le filtrage du courant de reference pour la commande du filtre actif parallele. C Benachaiba, A Bassou, B Mazari ...

Etat Du Magnesium Dans Quelques Sols Sales Du Sud Et Du ...

African Journals Online (AJOL)

étude a été réalisée sur 86 échantillons de sols provenant du Centre et du Sud de l´Irak. L\\'expérimentation a consisté, d´une part, à calculer les différents sels dominants dans les sols salés par la méthode de combinaison hypothétique et, ...

Electrical conductivity and viscosity of borosilicate glasses and melts

DEFF Research Database (Denmark)

Ehrt, Doris; Keding, Ralf

2009-01-01

, 0 to 62·5 mol% B2O3, and 25 to 85 mol% SiO2. The glass samples were characterised by different methods. Refractive indices, density and thermal expansion were measured. Phase separation effects were investigated by electron microscopy. The electrical conductivity of glasses and melts were determined......Simple sodium borosilicate and silicate glasses were melted on a very large scale (35 l Pt crucible) to prepare model glasses of optical quality in order to investigate various properties depending on their structure. The composition of the glass samples varied in a wide range: 3 to 33·3 mol% Na2O...... by impedance measurements in a wide temperature range (250 to 1450°C). The activation energies were calculated by Arrhenius plots in various temperature regions: below the glass transition temperature, Tg, above the melting point, Tl, and between Tg and Tl. Viscosity measurements were carried out...

Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte Carlo

Energy Technology Data Exchange (ETDEWEB)

Ledieu, A

2004-10-15

This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations; Alteration par l'eau des verres borosilicates: experiences, modelisation et simulations Monte-Carlo

Energy Technology Data Exchange (ETDEWEB)

Ledieu, A

2004-10-01

This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

Determination of boron in borosilicate glasses by neutron capture prompt gamma-ray activation analysis

Energy Technology Data Exchange (ETDEWEB)

Riley, Jr, J E; Lindstrom, R M

1987-01-01

Major levels of boron in borosilicate glasses were determined nondestructively by neutron activation analysis. The effects of neutron self-shielding by boron (1 to 8% by weight) are examined. Results of the analysis of a series of glasses with increasing boron composition are 1.150 +- .005% and 7.766 +- .035% for the low and high members of the series. Once analyzed, the glasses are useful as secondary standards for alpha track counting, and also ion and electron microprobe analyses of glasses. 12 refs.; 3 tables.

Corrosion of inconel in high-temperature borosilicate glass melts containing simulant nuclear waste

Science.gov (United States)

Mao, Xianhe; Yuan, Xiaoning; Brigden, Clive T.; Tao, Jun; Hyatt, Neil C.; Miekina, Michal

2017-10-01

The corrosion behaviors of Inconel 601 in the borosilicate glass (MW glass) containing 25 wt.% of simulant Magnox waste, and in ZnO, Mn2O3 and Fe2O3 modified Mg/Ca borosilicate glasses (MZMF and CZMF glasses) containing 15 wt.% of simulant POCO waste, were evaluated by dimensional changes, the formation of internal defects and changes in alloy composition near corrosion surfaces. In all three kinds of glass melts, Cr at the inconel surface forms a protective Cr2O3 scale between the metal surface and the glass, and alumina precipitates penetrate from the metal surface or formed in-situ. The corrosion depths of inconel 601 in MW waste glass melt are greater than those in the other two glass melts. In MW glass, the Cr2O3 layer between inconel and glass is fragmented because of the reaction between MgO and Cr2O3, which forms the crystal phase MgCr2O4. In MZMF and CZMF waste glasses the layers are continuous and a thin (Zn, Fe, Ni, B)-containing layer forms on the surface of the chromium oxide layer and prevents Cr2O3 from reacting with MgO or other constituents. MgCr2O4 was observed in the XRD analysis of the bulk MW waste glass after the corrosion test, and ZrSiO4 in the MZMF waste glass, and ZrSiO4 and CaMoO4 in the CZMF waste glass.

The reader’s role in the fiction of Menán du Plessis

Directory of Open Access Journals (Sweden)

M. J. Daymond

1992-05-01

Full Text Available The reception theory’ of Wolfgang Iser is used to explore the effects of the differences in the narration of Du Plessis’ novels. The chief differences are the degree of consciousness with which the reader engages in meaning-making and the level at which the reader encounters the major enigma on which the larger interpretation of each novel rests. Also considered are some implications of the analogy, to which my interpretation leads, between narrative form and Du Plessis’ judgement of her world.

Réflexion sur l’origine du processus de segmentation du marche du travail

Directory of Open Access Journals (Sweden)

Attia Nicole

2006-01-01

Full Text Available (francuski Ce travail propose une réflexion sur l'origine du processus de segmentation du marché du travail par rapport à l'entreprise. Se situe-t-elle au sein même de l'entreprise ou en amont, c'est à dire entre les entreprises? Cela revient à se demander si on peut avoir une approche microéconomique ou macroéconomique de la segmentation et, à s'interroger sur le rôle réel tenu par les firmes dans le processus. Déterminant pour la théorie, ce rôle est à repenser selon la réponse apportée à notre question.

Original Paper Performances comparées du HDL-cholestérol et du ...

African Journals Online (AJOL)

CT/HDL-C) et du HDL-Cholestérol est le meilleur prédicteur du SMet chez les adultes béninois. .... (Canada) et du. Ministère de la Santé du Bénin. Le consentement éclairé écrit a été obtenu de chaque participant avant leur recrutement dans.

Structure, thermal stability and resistance under external irradiation of rare earths and molybdenum-rich alumino-borosilicate glasses

International Nuclear Information System (INIS)

Chouard, N.

2011-01-01

In France, the highly radioactive nuclear liquid wastes arising from spent nuclear fuel reprocessing (fission products + minor actinides (FPA)) are currently immobilized in an alumino-borosilicate glass called 'R7T7'. In the future, the opportunity of using new alumino-borosilicate glass compositions (HTC glasses) is considered in order to increase the waste loading in glasses and thus significantly decrease the number of glass canisters. However, the increase of the concentration of FPA could lead to the crystallization of rare-earth-rich phases (Ca 2 RE 8 (SiO 4 ) 6 O 2 ) or molybdenum-rich phases (CaMoO 4 , Na 2 MoO 4 ) during melt cooling, which can modify the confinement properties of the glass (chemical durability, self-irradiation resistance..), particularly if they can incorporate radionuclides α or β in their structure. This thesis can be divided into two parts: The first part deals with studying the relationship that can occur between the composition, the structure and the crystallization tendency of simplified seven oxides glasses, belonging to the SiO 2 -B 2 O 3 -Al 2 O 3 -Na 2 O-CaO-MoO 3 -Nd 2 O 3 system and derived from the composition of the HTC glass at 22,5 wt. % in FPA. The impact of the presence of platinoid elements (RuO 2 in our case) on the crystallization of the different phases is also studied. The second part deals with the effect of actinides α decays and more particularly of nuclear interactions essentially coming from recoil nuclei (simulated here by heavy ions external irradiations) on the behaviour under irradiation of an alumino-borosilicate glass containing apatite Ca 2 Nd 8 (SiO 4 ) 6 O 2 crystals, that can incorporate actinides in their structure. Two samples containing apatite crystals with different size are studied, in order to understand the impact of microstructure on the irradiation resistance of this kind of material. (author) [fr

Régionalisation du recrutement du personnel de santé au Burkina ...

International Development Research Centre (IDRC) Digital Library (Canada)

Régionalisation du recrutement du personnel de santé au Burkina Faso ... le ministère a adopté une politique de recrutement régionalisé de certaines catégories du ... de comprendre le contexte dans lequel une telle stratégie a été formulée, ...

Photoelastic examination of borosilicate glass discs used in the insulating legs for the NSF tandem

International Nuclear Information System (INIS)

Acton, W.J.; Cundy, D.

1981-04-01

The results are presented of a photoelastic stress analysis carried out to establish the effect of re-annealing borosilicate glass discs used in the insulating legs of the 30 MV tandem van de Graaff accelerator of the NSF. The results show that re-annealing of the glass discs has no measurable effect on reducing the high stress at inclusions and re-emphasise the need to exercise great care in selecting suitable discs for use in the insulating legs. (U.K.)

35 Typologie des eaux de surface du bassin du Sebou par multi ...

African Journals Online (AJOL)

PR BOKO

2Service de protection de la qualité de l'eau, Agence du Bassin Hydraulique du ... pour montrer l'évolution de la qualité biologique des eaux de surface du ..... Biological Indicators of Freshwater Pollution and Environmental Management,.

Caractérisation des sables et morphologie du fond du lac du ...

African Journals Online (AJOL)

Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d\\'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

Caractérisation des sables et morphologie du fond du lac du ...

African Journals Online (AJOL)

Administrateur

Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

Engagez-vous, devenez délégué(e) du personnel du CERN

CERN Multimedia

Staff Association

2017-01-01

Dans notre ECHO N° 275, nous avons annoncé les élections à venir au Conseil du personnel du CERN. Dans le présent ECHO, nous vous informons du lancement du processus des élections qui débute par le dépôt des candidatures. Tous les titulaires, boursiers et associés, qui sont aussi membres de l’Association du personnel, peuvent s’engager et déposer leur candidature entre le 11 septembre à 08 h 00 et le 13 octobre 2017 à 17 h 00. N’hésitez plus, remplissez le formulaire de candidature, présentez-vous aux élections au Conseil du personnel afin de pouvoir représenter et défendre vos collègues du personnel du CERN. ÊTRE DÉLÉGUÉ(E), C’EST QUOI ? Poser la question à plusieurs d...

W.E.B. Du Bois and Caste Education: Racial Capitalist Schooling from Reconstruction to Jim Crow

Science.gov (United States)

Pierce, Clayton

2017-01-01

This essay provides the first account and examination of caste education in the work of W.E.B. Du Bois. In so doing, I argue that caste education plays a central role in realizing the political and social goals of racial capitalist society for Du Bois. Using Du Bois's caste analytic, I take up and articulate three biopolitical governing strategies…

Water leaching of borosilicate glasses: experiments, modeling and Monte Carlo simulations

International Nuclear Information System (INIS)

Ledieu, A.

2004-10-01

This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

Aqueous corrosion of borosilicate glasses: experiments, modeling and Monte-Carlo simulations

International Nuclear Information System (INIS)

Ledieu, A.

2004-10-01

This work is concerned with the corrosion of borosilicate glasses with variable oxide contents. The originality of this study is the complementary use of experiments and numerical simulations. This study is expected to contribute to a better understanding of the corrosion of nuclear waste confinement glasses. First, the corrosion of glasses containing only silicon, boron and sodium oxides has been studied. The kinetics of leaching show that the rate of leaching and the final degree of corrosion sharply depend on the boron content through a percolation mechanism. For some glass contents and some conditions of leaching, the layer which appears at the glass surface stops the release of soluble species (boron and sodium). This altered layer (also called the gel layer) has been characterized with nuclear magnetic resonance (NMR) and small angle X-ray scattering (SAXS) techniques. Second, additional elements have been included in the glass composition. It appears that calcium, zirconium or aluminum oxides strongly modify the final degree of corrosion so that the percolation properties of the boron sub-network is no more a sufficient explanation to account for the behavior of these glasses. Meanwhile, we have developed a theoretical model, based on the dissolution and the reprecipitation of the silicon. Kinetic Monte Carlo simulations have been used in order to test several concepts such as the boron percolation, the local reactivity of weakly soluble elements and the restructuring of the gel layer. This model has been fully validated by comparison with the results on the three oxide glasses. Then, it has been used as a comprehensive tool to investigate the paradoxical behavior of the aluminum and zirconium glasses: although these elements slow down the corrosion kinetics, they lead to a deeper final degree of corrosion. The main contribution of this work is that the final degree of corrosion of borosilicate glasses results from the competition of two opposite mechanisms

The dissolution behavior of borosilicate glasses in far-from equilibrium conditions

Science.gov (United States)

Neeway, James J.; Rieke, Peter C.; Parruzot, Benjamin P.; Ryan, Joseph V.; Asmussen, R. Matthew

2018-04-01

An area of agreement in the waste glass corrosion community is that, at far-from-equilibrium conditions, the dissolution of borosilicate glasses used to immobilize nuclear waste is known to be a function of both temperature and pH. The aim of this work is to study the effects of temperature and pH on the dissolution rate of three model nuclear waste glasses (SON68, ISG, AFCI). The dissolution rate data are then used to parameterize a kinetic rate model based on Transition State Theory that has been developed to model glass corrosion behavior in dilute conditions. To do this, experiments were conducted at temperatures of 23, 40, 70, and 90 °C and pH (22 °C) values of 9, 10, 11, and 12 with the single-pass flow-through (SPFT) test method. Both the absolute dissolution rates and the rate model parameters are compared with previous results. Rate model parameters for the three glasses studied here are nearly equivalent within error and in relative agreement with previous studies though quantifiable differences exist. The glass dissolution rates were analyzed with a linear multivariate regression (LMR) and a nonlinear multivariate regression performed with the use of the Glass Corrosion Modeling Tool (GCMT), with which a robust uncertainty analysis is performed. This robust analysis highlights the high degree of correlation of various parameters in the kinetic rate model. As more data are obtained on borosilicate glasses with varying compositions, a mathematical description of the effect of glass composition on the rate parameter values should be possible. This would allow for the possibility of calculating the forward dissolution rate of glass based solely on composition. In addition, the method of determination of parameter uncertainty and correlation provides a framework for other rate models that describe the dissolution rates of other amorphous and crystalline materials in a wide range of chemical conditions. The higher level of uncertainty analysis would provide

Ecologie du phytoplancton du lac Kivu

Directory of Open Access Journals (Sweden)

Sarmento, H.

2008-01-01

Full Text Available Speciation within the African Coffee Pathogen. Cet article analyse s'il est avantageux d'utiliser le compost au lieu de l'engrais minéral pour produire la laitue dans la zone urbaine et péri-urbaine de Yaoundé. Les résultats de terrain montrent l'obtention de rendements et profits plus élevés lorsqu'on utilise le compost. Les résultats de la fonction de production Cobb-Douglas prouvent que l'utilisation du compost est statistiquement significative pour expliquer la variation de rendement de la laitue et que le compost est l'intrant le plus productif. D'autres résultats montrent que le compost fournit la matière organique utile au sol et que les besoins d'irrigation en eau de la culture sont réduits grâce à l'utilisation du compost. Par conséquent, malgré le fait que l'application du compost demande une main-d'oeuvre beaucoup plus élevée, son utilisation est généralement bénéfique pour les agriculteurs vivant aux alentours de Yaoundé. Les programmes de vulgarisation de cet intrant pour encourager son adoption devraient donc figurer parmi les points prioritaires dans la politique agricole du gouvernement camerounais.

Wetspun poly-L-(lactic acid)-borosilicate bioactive glass scaffolds for guided bone regeneration

Energy Technology Data Exchange (ETDEWEB)

Fernandes, João S., E-mail: joao.fernandes@dep.uminho.pt [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga/Guimarães (Portugal); Reis, Rui L. [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga/Guimarães (Portugal); Pires, Ricardo A., E-mail: rpires@dep.uminho.pt [3B' s Research Group - Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, AvePark-Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Barco GMR (Portugal); ICVS/3B' s - PT Government Associate Laboratory, Braga/Guimarães (Portugal)

2017-02-01

We developed a porous poly-L-lactic acid (PLLA) scaffold compounded with borosilicate bioactive glasses (BBGs) endowing it with bioactive properties. Porous PLLA-BBG fibre mesh scaffolds were successfully prepared by the combination of wet spinning and fibre bonding techniques. Micro-computed tomography (μCT) confirmed that the PLLA-BBG scaffolds containing ≈ 25% of BBGs (w/w) exhibited randomly interconnected porous (58 to 62% of interconnectivity and 53 to 67% of porosity) with mean pore diameters higher that 100 μm. Bioactivity and degradation studies were performed by immersing the scaffolds in simulated body fluid (SBF) and ultrapure water, respectively. The PLLA-BBG scaffolds presented a faster degradation rate with a constant release of inorganic species, which are capable to produce calcium phosphate structures at the surface of the material after 7 days of immersion in SBF (Ca/P ratio of ~ 1.7). Cellular in vitro studies with human osteosarcoma cell line (Saos-2) and human adipose-derived stem cells (hASCs) showed that PLLA-BBGs are not cytotoxic to cells, while demonstrating their capacity to promote cell adhesion and proliferation. Overall, we showed that the proposed scaffolds present a tailored kinetics on the release of inorganic species and controlled biological response under conditions that mimic the bone physiological environment. - Highlights: • We prepared borosilicate glasses and their PLLA composites in the form of fibres. • These glasses imparted bioactivity and controlled degradability to the fibres. • The prepared fibres did not elicit cytotoxicity. • hASCs attached and proliferated in the surface and inner sections of the scaffolds. • The composites present appropriate properties to be used in bone tissue engineering.

Wetspun poly-L-(lactic acid)-borosilicate bioactive glass scaffolds for guided bone regeneration

International Nuclear Information System (INIS)

Fernandes, João S.; Reis, Rui L.; Pires, Ricardo A.

2017-01-01

We developed a porous poly-L-lactic acid (PLLA) scaffold compounded with borosilicate bioactive glasses (BBGs) endowing it with bioactive properties. Porous PLLA-BBG fibre mesh scaffolds were successfully prepared by the combination of wet spinning and fibre bonding techniques. Micro-computed tomography (μCT) confirmed that the PLLA-BBG scaffolds containing ≈ 25% of BBGs (w/w) exhibited randomly interconnected porous (58 to 62% of interconnectivity and 53 to 67% of porosity) with mean pore diameters higher that 100 μm. Bioactivity and degradation studies were performed by immersing the scaffolds in simulated body fluid (SBF) and ultrapure water, respectively. The PLLA-BBG scaffolds presented a faster degradation rate with a constant release of inorganic species, which are capable to produce calcium phosphate structures at the surface of the material after 7 days of immersion in SBF (Ca/P ratio of ~ 1.7). Cellular in vitro studies with human osteosarcoma cell line (Saos-2) and human adipose-derived stem cells (hASCs) showed that PLLA-BBGs are not cytotoxic to cells, while demonstrating their capacity to promote cell adhesion and proliferation. Overall, we showed that the proposed scaffolds present a tailored kinetics on the release of inorganic species and controlled biological response under conditions that mimic the bone physiological environment. - Highlights: • We prepared borosilicate glasses and their PLLA composites in the form of fibres. • These glasses imparted bioactivity and controlled degradability to the fibres. • The prepared fibres did not elicit cytotoxicity. • hASCs attached and proliferated in the surface and inner sections of the scaffolds. • The composites present appropriate properties to be used in bone tissue engineering.

4.2. The kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to kinetics of nitric acid decomposition of calcined borosilicate raw material of Ak-Arkhar Deposit. The dependence of nitric acid decomposition of calcined boric raw material for extraction of boron oxide on temperature (20-100 deg C) and process duration (15-60 minutes) was defined. It was defined that at temperature increasing the extraction rate of boron oxide increases from 20.8 to 78.6%.

Entrapment of 137Cs vapour generated during vitrification and casting of cesium borosilicate glass by inorganic materials

International Nuclear Information System (INIS)

Ram, Ramu; Gandhi, Shyamala; Dash, A.; Varma, R.N.

2003-01-01

Efficiency of different inorganic materials like zirconium antimonate (ZrA), ammonium molybdophosphate (AMP), synthetic zeolites, activated charcoal, glass wool etc, towards the entrapment of 137 Cs vapour escaping during vitrification and casting of cesium borosilicate glass required for the preparation of 137 Cs sources for medical and industrial applications have been determined. The recovery of entrapped cesium using dilute acids for subsequent recycling has also been explored. (author)

Fiche technique du spermogramme et du spermocytogramme ...

African Journals Online (AJOL)

En Afrique la stérilité du couple constitue un drame social. Selon l'OMS, environ 8 à 12 % des couples africains sont touchés par une infertilité. La responsabilité masculine dans la stérilité est comprise entre 30 à 40%. Les causes de l'infertilité masculine peuvent être l'impuissance et/ ou l'altération du sperme. L'étude de ...

Structural and crystallisation study of a rare earth alumino borosilicate glass designed for nuclear waste confinement; Etude de la structure et du comportement en cristallisation d'un verre nucleaire d'aluminoborosilicate de terre rare

Energy Technology Data Exchange (ETDEWEB)

Quintas, A

2007-09-15

This work is devoted to the study of a rare earth alumino borosilicate glass, which molar composition is 61,81 SiO{sub 2} - 3,05 Al{sub 2}O{sub 3} - 8,94 B{sub 2}O{sub 3} - 14,41 Na{sub 2}O - 6,33 CaO - 1,90 ZrO{sub 2} - 3,56 Nd{sub 2}O{sub 3}, and envisaged for the immobilization of nuclear wastes originating from the reprocessing of high discharge burn up spent fuel. From a structural viewpoint, we investigated the role of the modifier cations on the arrangement of the glass network through different modifications of the glass composition: variation of the Na/Ca ratio and modification of the nature of the alkali and alkaline earth cations. The NMR and Raman spectroscopic techniques were useful to determine the distribution of modifier cations among the glass network and also to cast light on the competition phenomena occurring between alkali and alkaline earth cations for charge compensation of [AlO{sub 4}]{sup -} and [BO{sub 4}]{sup -} species. The neodymium local environment could be probed by optical absorption and EXAFS spectroscopies which enabled to better understand the insertion mode of Nd{sup 3+} ions among the silicate domains of the glass network. Concerning the crystallization behavior we were interested in how the glass composition may influence the crystallization processes and especially the formation of the apatite phase of composition Ca{sub 2}Nd{sub 8}(SiO{sub 4}){sub 6}O{sub 2}. In particular, this work underlined the important role of both alkaline earth and rare earth cations on the crystallization of the apatite phase. (author)

Alpha self irradiation effects in nuclear borosilicate glass

International Nuclear Information System (INIS)

Peuget, S.; Roudil, D.; Deschanels, X.; Jegou, C.; Broudic, V.; Bart, J.M.

2004-01-01

The properties of actinide glasses are studied in the context of high-level waste management programs. Reprocessing high burnup fuels in particular will increase the minor actinide content in the glass package, resulting in higher cumulative alpha decay doses in the glass, and raising the question of the glass matrix behavior and especially its containment properties. The effect of alpha self-irradiation on the glass behavior is evaluated by doping the glass with a short-lived actinide ( 244 Cm) to reach in several years the alpha dose received by the future glass packages over several thousand years. 'R7T7' borosilicate glasses were doped with 3 different curium contents (0.04, 0.4 and 1.2 wt% 244 CmO 2 ). The density and mechanical properties of the curium-doped glasses were characterized up to 2. 10 18 α/g, revealing only a slight evolution of the macroscopic behavior of R7T7 glass in this range. The leaching behavior of curium-doped glass was also studied by Soxhlet tests. The results do not show any significant evolution of the initial alteration rate with the alpha dose. (authors)

Session du Conseil du CERN : le ministre britannique, Robert Jackson, souligne l'intérêt de on pays pour l'avenir du CERN : décisions du Conseil pour la mise en oeuvre des recommandations du Comité d'évaluation du CERN: départ anticipé pour 200 membres au moins du personnel - mise à jour de la méthode de calcule pour les contributions des Etats Membres au budget

CERN Multimedia

CERN Press Office. Geneva

1988-01-01

Session du Conseil du CERN : le ministre britannique, Robert Jackson, souligne l'intérêt de on pays pour l'avenir du CERN : décisions du Conseil pour la mise en oeuvre des recommandations du Comité d'évaluation du CERN: départ anticipé pour 200 membres au moins du personnel - mise à jour de la méthode de calcule pour les contributions des Etats Membres au budget

The role of Rad 51 protein in radioresistance of spheroid model of Du 145 prostate carcinoma cell line

International Nuclear Information System (INIS)

Taghizadeh, M.; Khoei, S.; Nikoofar, A. R.; Ghamsari, L.; Goliaei, B.

2009-01-01

Rad 51 is a protein with critical role in double strand break repair. Down-regulation of this protein has a significant effect in radiosensitivity of some cell lines like prostate carcinoma. Compared to monolayer cell culture model, the spheroids are more resistant to radiation. The aim of the current study was to determine the Rad 51 protein level in Du 145 spheroids, and monolayer cells before and after exposure to gamma irradiation. Materials and Methods: In the present study, western blot was used to determine the level of Rad 51 protein in Du 145 cell line grown as monolayer and spheroid. Results: Western blot analysis showed that in the spheroid cells, Rad 51 had an elevated level before and after radiation in comparison with monolayer cells. Higher doses of radiation induced elevated expression of Rad 51 protein in both culture models.The level of at protein after exposure to gamma rays had been time-dependent. Conclusion: Rad 51 might act as a mediator of radiation resistance in tumor cells. Repression of Rad 51 activity could be a prominent strategy to overcome radiation resistance of tumors.

Thorium reactions in borosilicate-glass/water systems

International Nuclear Information System (INIS)

Rai, D.; Hess, N.J.; Felmy, A.R.; Moore, D.A.; Yui, M.

2005-01-01

Studies were conducted on the dissolution of Th-doped borosilicate glass, a complex assemblage of 24 different elements in various proportions, in a wide range of pH values (0.5 to 12) and carbonate (as high as 6.2 m) and bicarbonate (as high as 1.0 m) concentrations, and as a function of time to determine whether the observed thorium concentrations exhibit an equilibrium phenomenon and to ascertain whether existing thermodynamic data can be used to interpret these results. Measurable Th concentrations were observed in either the very acidic (pH 0.5 to 4) solutions or alkaline solutions containing relatively high carbonate/bicarbonate concentrations. Steady state Th concentrations were reached over time from both the oversaturation and undersaturation directions, indicating that Th concentrations are controlled by an equilibrium solubility phenomenon. The XRD, EXAFS, and thermodynamic analyses of solubility data failed to definitively identify the nature of the solubility-controlling solid in this complex system; however, the data suggests that the solubility-controlling solid most likely involves the Th-silicate phase and that the observed Th concentrations are up to many orders of magnitude lower than in equilibrium with ThO 2 (am). The solubility study also showed that existing thermodynamic data for carbonato complexes of Th can be used to reliably predict Th concentrations in relatively dilute to concentrated carbonate/bicarbonate solutions. (orig.)

La population du Moyen-Orient et de l'Afrique du Nord contribue ...

International Development Research Centre (IDRC) Digital Library (Canada)

29 avr. 2016 ... Le degré d'apport au contenu varie grandement d'une population à l'autre. Si les habitants du Moyen-Orient et de l'Afrique du Nord (région MENA) utilisent Wikipédia, ils y contribuent cependant moins que les populations d'autres régions du monde. Le contenu au sujet de la région MENA est, le plus ...

Néotoponymie contestée à Potchefstroom / Tlokwe (Province du Nord-Ouest, Afrique du Sud

Directory of Open Access Journals (Sweden)

Myriam Houssay-Holzschuch

2010-09-01

Full Text Available Illustration 1 - Extrait du site de la municipalité de Potchefstroom / TlokweSource : http://www.potch.co.za/newsarchive/streetnames.htmlIllustration 2- Potchefstroom (Afrique du SudAuteur : Béatrice Obry-Guyot, début décembre 2007.Illustration 3 - Extrait du plan Google Map de PotchefstroomSource : Google Map.La question toponymique en Afrique du Sud sur la longue durée porte sur deux thèmes essentiels porteurs de controverses : le plurilinguisme et le marquage symbolique et mémoriel du te...

Ksenia Pimenova, Les sources de savoirs. Le renouveau du bouddhisme et du chamanisme chez les Touvas de la Sibérie du Sud

OpenAIRE

Pimenova, Ksenia

2013-01-01

Cette thèse présente une étude comparative du « renouveau » post-soviétique du chamanisme et du bouddhisme tibétain (école Guélougpa) chez les Touvas, un des peuples autochtones de la Sibérie du Sud (Russie). Ce phénomène a lieu après des décennies de politique antireligieuse (dès la fin des années 1920 jusqu’aux années 1980) ayant abouti à la destruction de la communauté bouddhique et à la marginalisation du chamanisme. Nous analysons le chamanisme et le bouddhisme post-soviétiques comme deu...

Investigation of local environment around rare earths (La and Eu) by fluorescence line narrowing during borosilicate glass alteration

Energy Technology Data Exchange (ETDEWEB)

Molières, Estelle [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Panczer, Gérard; Guyot, Yannick [Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne cedex (France); Jollivet, Patrick [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Majérus, Odile; Aschehoug, Patrick; Barboux, Philippe [Laboratoire de Chimie de la Matière Condensée de Paris, UMR-CNRS 7574, École Nationale Supérieure de Chimie de Paris (ENSCP Chimie-ParisTech), 11 rue Pierre et Marie Curie, 75231 Paris (France); Gin, Stéphane [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France); Angeli, Frédéric, E-mail: frederic.angeli@cea.fr [CEA – DEN-DTCD-LCV-SECM Laboratoire d' études du Comportement à Long Terme, 30207 Bagnols-sur-Cèze (France)

2014-01-15

The local environment of europium in soda-lime borosilicate glasses with a range of La{sub 2}O{sub 3} content was probed by continuous luminescence and Fluorescence Line Narrowing (FLN) to investigate the local environment of rare earth elements in pristine and leached glass. After aqueous leaching at 90 °C at pH 7 and 9.5, rare earths were fully retained and homogeneously distributed in the amorphous alteration layer (commonly called gel). Two separate silicate environments were observed in pristine and leached glasses regardless of the lanthanum content and the leaching conditions. A borate environment surrounding europium was not observed in pristine and leached glasses. During glass alteration, OH groups were located around the europium environment, which became more organized (higher symmetry) in the first coordination shell. -- Highlights: • No borate environment surrounding europium was detected in pristine borosilicate glasses. • Up to 12 mol% of REE2O3 in glass, local environment of europium does not significantly change. • Europium environment becomes more ordered and symmetric in gels than in pristine glasses. • Two distinct silicate sites were observed, as well in pristine glass as in gels (leached glasses). • In altered glasses, OH groups were located around europium.

Investigation of local environment around rare earths (La and Eu) by fluorescence line narrowing during borosilicate glass alteration

International Nuclear Information System (INIS)

Molières, Estelle; Panczer, Gérard; Guyot, Yannick; Jollivet, Patrick; Majérus, Odile; Aschehoug, Patrick; Barboux, Philippe; Gin, Stéphane; Angeli, Frédéric

2014-01-01

The local environment of europium in soda-lime borosilicate glasses with a range of La 2 O 3 content was probed by continuous luminescence and Fluorescence Line Narrowing (FLN) to investigate the local environment of rare earth elements in pristine and leached glass. After aqueous leaching at 90 °C at pH 7 and 9.5, rare earths were fully retained and homogeneously distributed in the amorphous alteration layer (commonly called gel). Two separate silicate environments were observed in pristine and leached glasses regardless of the lanthanum content and the leaching conditions. A borate environment surrounding europium was not observed in pristine and leached glasses. During glass alteration, OH groups were located around the europium environment, which became more organized (higher symmetry) in the first coordination shell. -- Highlights: • No borate environment surrounding europium was detected in pristine borosilicate glasses. • Up to 12 mol% of REE2O3 in glass, local environment of europium does not significantly change. • Europium environment becomes more ordered and symmetric in gels than in pristine glasses. • Two distinct silicate sites were observed, as well in pristine glass as in gels (leached glasses). • In altered glasses, OH groups were located around europium

Bulletin du CRDI #124

International Development Research Centre (IDRC) Digital Library (Canada)

Les femmes jouent un rôle important dans les exploitations minières artisanales et à petite échelle en Afrique subsaharienne. De concert ... Couverture du livre: Une vie saine pour les femmes et les enfants vulnérables · Couverture du livre: Entre el activismo y la intervención · Couverture du livre: Revitalizing Health for All.

Bulletin du CRDI #125

International Development Research Centre (IDRC) Digital Library (Canada)

L'IOSRS remporte le prix de la diplomatie scientifique · GrowInclusive : la plateforme tant attendue est en construction · Toutes les nouvelles. Activités à venir. Semaine du développement international 2018. Le CRDI célébrera la Semaine du développement international du 4 au 10 février 2018. Suivez-nous sur Twitter et ...

A review of phase separation in borosilicate glasses, with reference to nuclear fuel waste immobilization

International Nuclear Information System (INIS)

Taylor, P.

1990-08-01

This report reviews information on miscibility limits in borosilicate glass-forming systems. It includes both a literature survey and an account of experimental work performed within the Canadian Nuclear Fuel Waste Management Program. Emphasis is placed on the measurement and depiction of miscibility limits in multicomponent (mainly quaternary) systems, and the effects of individual components on the occurrence of phase separation. The behaviour of the multicomponent system is related to that of simpler (binary and ternary) glass systems. The possible occurrence of phase separation, as well as its avoidance, during processing of nuclear waste glasses is discussed

Profils des porteurs du VIH/SIDA au début du traitement ...

African Journals Online (AJOL)

But : Décrire les profils des porteurs de VIH/sida au début du traitement antirétroviral. Matériels et méthode: Les dossiers des porteurs du VIH/sida de la région maritime ont été analysés de mai 2008 à avril 2009 par le comité thérapeutique. Résultats: Parmi les 641 dossiers analysés, 67,40% venaient du district de Yoto.

Magnetic Glass Ceramics by Sintering of Borosilicate Glass and Inorganic Waste

Directory of Open Access Journals (Sweden)

Inès M. M. M. Ponsot

2014-07-01

Full Text Available Ceramics and glass ceramics based on industrial waste have been widely recognized as competitive products for building applications; however, there is a great potential for such materials with novel functionalities. In this paper, we discuss the development of magnetic sintered glass ceramics based on two iron-rich slags, coming from non-ferrous metallurgy and recycled borosilicate glass. The substantial viscous flow of the glass led to dense products for rapid treatments at relatively low temperatures (900–1000 °C, whereas glass/slag interactions resulted in the formation of magnetite crystals, providing ferrimagnetism. Such behavior could be exploited for applying the obtained glass ceramics as induction heating plates, according to preliminary tests (showing the rapid heating of selected samples, even above 200 °C. The chemical durability and safety of the obtained glass ceramics were assessed by both leaching tests and cytotoxicity tests.

Les effets du changement climatique dans le bassin du Congo : la ...

International Development Research Centre (IDRC) Digital Library (Canada)

22 avr. 2016 ... Dans le bassin du fleuve Congo, plus de 80 % des habitants vivent exclusivement de l'agriculture, de la pêche, de l'élevage et de la cueillette, qui sont des activités largement tributaires du climat.

(Sorghum bicolor (L.) Moench) du Nord du Burkina Faso

African Journals Online (AJOL)

SARAH

29 déc. 2014 ... sorghos à grains sucrés ont un cycle court et arrivent donc à maturité avant les autres sorghos et le mil d'où leur exploitation comme aliment de soudure par les paysans. L'organisation de la diversité morphologique des accessions de sorghos à grains sucrés du Nord du. Burkina autour principalement des ...

Etude de la transition ferroelectrique-ferroelastique du KD2PO4 forme du front de phase en fonction du gradient thermique

OpenAIRE

Kvítek, Zdeněk

2010-01-01

Etude de la transition ferroelectrique-ferroelastique du KD2PO4 forme du front de phase en fonction du gradient thermique The thesis explores complex process of first order transition of KD2PO4 crystal from tetragonal phase to ferroelectric - ferroelastic orthorhombic phase and back at temperature 209 K. The experimental set up of nitrogeneous cryostat allowes temperature and temperature gradient variations during simultaneous three axes optical sample observations, dielectric measurements. T...

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politique de bas prix exercée par la Russie et le Qatar vient confirmer ce constat ; s'ajoute à cela l'entrée éventuelle du gaz non conven- tionnel, dont son prix actuel de 3/4 $US, offre aux USA l'opportunité d'être exportateur de ..... les compagnies à produire en matière du gaz naturel, tels le prix du gaz naturel, le prix des ...

Preparation and characterization of an improved borosilicate glass matrix for the incorporation of high level radioactive waste (HAW). Pt. 1

International Nuclear Information System (INIS)

Guber, W.; Hussain, M.; Kahl, L.; Ondracek, G.; Saidl, J.; Dippel, T.

1979-08-01

On the basis of laboratory and technical experience with the preparation and the characterization of borosilicate glasses as solidification matrix for high level radioactive waste solution (HAW), a borosilicate glass composition with optimum properties has been developed. Keeping in view the technical and final storage requirements, a number of glass compositions with varying proportions of influential components as Al, Mg, Na were prepared and thoroughly investigated for certain parameters as specific gravity, thermal conductivity, impact resistance, thermal expansion, viscosity, characteristic temperature points, specific heat, evaporation losses from the melt, electrical conductivity, leach resistance, tendency toward recrystallization and second phase formation. All the compositions (some with different amounts of Gd 2 O 3 , an expected neutron poision) contained 15 wt. % simulated HAW oxides. Samples for investigation were fabricated very close to the actual process conditions of vitrification. Two glass products GP12 and GP26 (3.7% Gd 2 O 3 ) have been selected out of 25 glasses as the optimised products for further thorough investigations. Leach resistance, viscosity at 1420 K, tendency towards recrystallization and second phase formation were the most important deciding factors. (orig.) [de

Titulaires de la bourse du CRDI aux chercheurs candidats au ...

International Development Research Centre (IDRC) Digital Library (Canada)

Université d'Ottawa, doctorat en développement international. ... The role of traditional actors in taxation in Sierra Leone: Unorthodox public-private ... Abonnez-vous à notre bulletin pour recevoir les nouvelles du CRDI chaque mois. Abonnez- ...

L'action du CRDI — le développement du secteur privé

International Development Research Centre (IDRC) Digital Library (Canada)

Cathy Egan

Le CRDI est du nombre. Il reconnaît depuis longtemps la valeur de l'industrie, des échanges et du commerce comme moteurs de la croissance économique. Grâce au soutien concret qu'il a accordé au développement du secteur privé, le CRDI a appris que deux types d'aide peuvent porter fruit : améliorer le con- texte dans ...

Operating Range for High Temperature Borosilicate Waste Glasses: (Simulated Hanford Enveloped)

International Nuclear Information System (INIS)

Mohammad, J.; Ramsey, W. G.; Toghiani, R. K.

2003-01-01

The following results are a part of an independent thesis study conducted at Diagnostic Instrumentation and Analysis Laboratory-Mississippi State University. A series of small-scale borosilicate glass melts from high-level waste simulant were produced with waste loadings ranging from 20% to 55% (by mass). Crushed glass was allowed to react in an aqueous environment under static conditions for 7 days. The data obtained from the chemical analysis of the leachate solutions were used to test the durability of the resulting glasses. Studies were performed to determine the qualitative effects of increasing the B2O3 content on the overall waste glass leaching behavior. Structural changes in a glass arising due to B2O3 were detected indirectly by its chemical durability, which is a strong function of composition and structure. Modeling was performed to predict glass durability quantitatively in an aqueous environment as a direct function of oxide composition

Identification des matériaux et étude du bâti : l’exemple du Clos du Cotentin

Directory of Open Access Journals (Sweden)

Julien Deshayes

2012-04-01

Full Text Available Partant de l’architecture vernaculaire de la Presqu’île du Cotentin, cette étude s’attache à montrer comment l'identification des matériaux de construction, replacée dans une problématique historique, peut fournir un outil d'analyse privilégié du bâti, notamment en matière de chronologie. L'identification des principaux centres carriers et de leur aire d'exportation permet de mieux appréhender l'évolution des modénatures et de raisonner sur des typologies cohérentes. L'acquisition de tels critères d'analyse, peu généralisables hors de régions très délimitées, est nécessairement liée à une expérience prolongée du terrain. L’exemple du Clos du Cotentin offre, en matière d'identification des matériaux et d'étude du bâti, un manifeste en faveur d'une approche topographique approfondie, susceptible de replacer l'architecture rurale dans le cadre d'une évolution historique.Based on the vernacular architecture of the Cotentin peninsula, this article sets out to show how the identification of construction materials, placed in a historical context, can offer a particularly useful tool for analysing buildings, notably for their chronology. The identification of the principle stone quarries and their zones of commercial influence gives information on the evolution of architectural proportions and permits the development of coherent typologies. The acquisition of such analytical criteria is difficult to generalise beyond strictly limited regions and are necessarily linked with in-depth familiarity with the territory concerned. The example that the Clos du Cotentin offers for the identification of building materials and the study of buildings may be seen as a manifesto in favour of a detailed topographical approach, capable of placing rural architecture in the framework of its historical evolution.

Separation process of zirconium and hafnium; Procede de separation du zirconium et du hafnium

Energy Technology Data Exchange (ETDEWEB)

Hure, J; Saint-James, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

About the separation different processes of zirconium-hafnium, the extraction by solvent in cross-current is the most easily the process usable on an industrial scale. It uses tributyl phosphate as solvent, diluted with white spirit to facilitate the decanting. Some exploratory tests showed that nitric environment seemed the most favorable for extraction; but a lot of other factors intervene in the separation process. We studied the influence of the acidity successively, the NO{sub 3}{sup -} ions concentration, the role of the cation coming with NO{sub 3}{sup -}, as well as the influence of the concentration of zirconium in the solution on the separation coefficient {beta} = {alpha}{sub Zr} / {alpha}{sub Hf}. (M.B.) [French] Des differents procedes de separation zirconium-hafnium, l'extraction par solvant en contre-courant est le procede le plus facilement utilisable a l'echelle industrielle. On utilise comme solvant le phosphate de tributyle, dilue avec du white spirit pour faciliter les decantations. Des essais preliminaires ont montre que le milieu nitrique semblait le plus favorable a l'extraction; mais beaucoup d'autres facteurs interviennent dans le processus de separation. Nous avons etudie successivement l'influence de l'acidite, celle de la concentration en ions NO{sub 3}{sup -}, le role du cation accompagnant NO{sub 3}{sup -}, ainsi que l'influence de la concentration en zirconium de la solution sur le coefficient de separation {beta} = {alpha}{sub Zr} / {alpha}{sub Hf}. (MB)

Structural and crystallisation study of a rare earth alumino borosilicate glass designed for nuclear waste confinement

International Nuclear Information System (INIS)

Quintas, A.

2007-09-01

This work is devoted to the study of a rare earth alumino borosilicate glass, which molar composition is 61,81 SiO 2 - 3,05 Al 2 O 3 - 8,94 B 2 O 3 - 14,41 Na 2 O - 6,33 CaO - 1,90 ZrO 2 - 3,56 Nd 2 O 3 , and envisaged for the immobilization of nuclear wastes originating from the reprocessing of high discharge burn up spent fuel. From a structural viewpoint, we investigated the role of the modifier cations on the arrangement of the glass network through different modifications of the glass composition: variation of the Na/Ca ratio and modification of the nature of the alkali and alkaline earth cations. The NMR and Raman spectroscopic techniques were useful to determine the distribution of modifier cations among the glass network and also to cast light on the competition phenomena occurring between alkali and alkaline earth cations for charge compensation of [AlO 4 ] - and [BO 4 ] - species. The neodymium local environment could be probed by optical absorption and EXAFS spectroscopies which enabled to better understand the insertion mode of Nd 3+ ions among the silicate domains of the glass network. Concerning the crystallization behavior we were interested in how the glass composition may influence the crystallization processes and especially the formation of the apatite phase of composition Ca 2 Nd 8 (SiO 4 ) 6 O 2 . In particular, this work underlined the important role of both alkaline earth and rare earth cations on the crystallization of the apatite phase. (author)

Basaltic glasses from Iceland and the deep sea: Natural analogues to borosilicate nuclear waste-form glass

International Nuclear Information System (INIS)

Jercinovic, M.J.; Ewing, R.C.

1987-12-01

The report provides a detailed analysis of the alteration process and products for natural basaltic glasses. Information of specific applicability to the JSS project include: * The identification of typical alteration products which should be expected during the long-term corrosion process of low-silica glasses. The leached layers contain a relatively high proportion of crystalline phases, mostly in the form of smectite-type clays. Channels through the layer provide immediate access of solutions to the fresh glass/alteration layer interface. Thus, glasses are not 'protected' from further corrosion by the surface layer. * Corrosion proceeds with two rates - an initial rate in silica-undersaturated environments and a long-term rate in silica-saturated environments. This demonstrates that there is no unexpected change in corrosion rate over long periods of time. The long-term corrosion rate is consistent with that of borosilicate glasses. * Precipitation of silica-containing phases can result in increased alteration of the glass as manifested by greater alteration layer thicknesses. This emphasizes the importance of being able to predict which phases form during the reaction sequence. * For natural basaltic glasses the flow rate of water and surface area of exposed glass are critical parameters in minimizing glass alteration over long periods of time. The long-term stability of basalt glasses is enhanced when silica concentrations in solution are increased. In summary, there is considerable agreement between corrosion phenomena observed for borosilicate glasses in the laboratory and those observed for natural basalt glasses of great age. (With 121 refs.) (authors)

Dynamique des populations du foreur des tiges du cacaoyer ...

African Journals Online (AJOL)

Objectif : Le foreur de tiges du cacaoyer, Eulophonotus myrmeleon Felder cause aujourd'hui d'énormes dégâts dans les cacaoyères ivoiriennes. La présente étude vise à déterminer les périodes de fortes attaques de ce déprédateur dans la région du Haut-Sassandra, la deuxième plus grande région de production de ...

Preliminary assessment of the controlled release of radionuclides from waste packages containing borosilicate waste glass

International Nuclear Information System (INIS)

Strachan, D.M.; McGrail, B.P.; Apted, M.J.; Engle, D.W.; Eslinger, P.W.

1990-06-01

The purpose of this report is to provide a preliminary assessment of the release-rate for an engineered barriers subsystem (EBS) containing waste packages of defense high-level waste borosilicate glass at geochemical and hydrological conditions similar to the those at Yucca Mountain. The relationship between the proposed Waste Acceptance Preliminary Specifications (WAPS) test of glass- dissolution rate and compliance with the NRC's release-rate criterion is also evaluated. Calculations are reported for three hierarchical levels: EBS analysis, waste-package analysis, and waste-glass analysis. The following conclusions identify those factors that most acutely affect the magnitude of, or uncertainty in, release-rate performance

Integrated Optic Surface Plasmon Resonance Measurements in a Borosilicate Glass Substrate

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Antonino Parisi

2008-11-01

Full Text Available The surface plasmon resonance (SPR technique is a well-known optical method that can be used to measure the refractive index of organic nano-layers adsorbed on a thin metal film. Although there are many configurations for measuring biomolecular interactions, SPR-based techniques play a central role in many current biosensing experiments, since they are the most suited for sensitive and quantitative kinetic measurements. Here we give some results from the analysis and numerical elaboration of SPR data from integrated optics experiments in a particular borosilicate glass, chosen for its composition offering the rather low refractive index of 1.4701 at 633 nm wavelength. These data regard the flow over the sensing region (metal window of different solutions with refractive indexes in the range of interest (1.3÷1.5 for the detection of contaminants in aqueous solutions. After a discussion of the principles of SPR, of the metal window design optimization by means of optical interaction numerical modeling, and of waveguide fabrication techniques, we give a description of system setup and experimental results. Optimum gold film window thickness and width in this guided-wave configuration has been for the first time derived and implemented on an integrated optic prototype device. Its characterization is given by means of the real time waveguide output intensity measurements, which correspond to the interaction between the sensing gold thin film window and the flowing analyte. The SPR curve was subsequently inferred. Finally, a modified version of the device is reported, with channel waveguides arranged in a Y-junction optical circuit, so that laser source stability requirements are lowered by a factor of 85 dB, making possible the use of low cost sources in practical applications.

Physique du deuil. Note sur la dernière vie de Roland Barthes

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Maïté Snauwaert

2013-03-01

Full Text Available Les remarques sur la tenue de la maison et du corps dans le quotidien domestique, conçue comme une éthique de la fidélité à la mère récemment disparue, apparaissent dans l’écrit privé du Journal de deuil de Roland Barthes comme un écho des observations faites dans le cours sur La préparation du roman. Participant d’une physique du vivre et de l’habiter qui met l’accent sur l’entretien quotidien du lieu, le silence et la difficulté de tout voyage, les « notations » du journal rendent compte de la condensation dans le corps de l’épreuve du deuil, et de la prise de conscience d’un dernier âge de la vie.In the personal writings of Journal de deuil, Roland Barthes’ remarks regarding the maintenance of the home and body are conceived of as an ethic of faithfulness to his recently deceased mother. They are considered in this article as an echo to the observations he makes during his lectures in the course La préparation du roman. Both emphasize the physicality of everyday life and the role played by one’s relationship to the home. By stressing the necessity of silence and the difficulties of leaving “the apartment”, the brief “notations” in the diary translate the physical concentration of the mourning experience, as well as the emergent understanding of a final stage of life.

Le Developmental Entrepreneurship Program du Massachusetts ...

International Development Research Centre (IDRC) Digital Library (Canada)

Faire en sorte que les étudiants venant des pays en développement pour étudier au MIT retournent ensuite dans leurs pays respectifs afin d'y concrétiser leurs idées est un souci majeur du MIT, des bailleurs de fonds et du milieu du développement. Ce projet palliera à ce souci en soutenant la formation des fellows du ...

"Cirque du Freak."

Science.gov (United States)

Rivett, Miriam

2002-01-01

Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and…

Suivi après le traitement du cancer du sein

Science.gov (United States)

Sisler, Jeffrey; Chaput, Geneviève; Sussman, Jonathan; Ozokwelu, Emmanuel

2016-01-01

Résumé Objectif Offrir aux médecins de famille un résumé des recommandations fondées sur les données probantes pour guider les soins aux survivantes traitées pour le cancer du sein. Qualité des données Une recherche documentaire a été effectuée dans MEDLINE entre 2000 et 2016 à l’aide des mots-clés anglais suivants : breast cancer, survivorship, follow-up care, aftercare, guidelines et survivorship care plans, en se concentrant sur la revue des lignes directrices publiées récemment par les organismes nationaux de cancérologie. Les données étaient de niveaux I à III. Message principal Les soins aux survivantes comportent 4 facettes : surveillance et dépistage, prise en charge des effets à long terme, promotion de la santé et coordination des soins. La surveillance des récidives ne se traduit que par une mammographie annuelle, et le dépistage d’autres cancers doit suivre les lignes directrices basées sur la population. La prise en charge des effets à long terme du cancer et de son traitement aborde des problèmes courants tels la douleur, la fatigue, le lymphœdème, la détresse et les effets indésirables des médicaments, de même que les préoccupations à long terme comme la santé du cœur et des os. La promotion de la santé met en relief les bienfaits de l’activité chez les survivantes du cancer, avec l’accent mis sur l’activité physique. Les soins aux survivantes sont de meilleure qualité lorsque divers services et professionnels de la santé participent aux soins, et le médecin de famille joue un rôle important dans la coordination des soins. Conclusion Les médecins de famille sont de plus en plus souvent les principaux fournisseurs de soins de suivi après le traitement du cancer du sein. Le cancer du sein doit être considéré comme une affection médicale chronique, même chez les femmes en rémission, et les patientes profitent de la même approche que celle utilisée pour les autres affections chroniques en

ETUDE DU COMPORTEMENT MECANIQUE DU BETON CELLULAIRE AUTOCLAVE PRODUIT EN ALGERIE

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R BELOUETTAR

2002-12-01

Full Text Available Ce travail présente une étude expérimentale du comportement mécanique du béton cellulaire autoclavé. L’étude est portée essentiellement sur une série d’essais mécaniques en compression quasistatique à différentes vitesses de déformation variables entre 10-4 s-1 et 10 s-1 et à deux états différents (état sec et état saturé d’eau. En général, l’augmentation de la vitesse de déformation donne une augmentation de la contrainte critique du béton cellulaire autoclavé. Le béton cellulaire autoclavé présente une sensibilité à la vitesse de déformation positive. La valeur du module d’élasticité est proche de la valeur standard (1.5 GPa pour un béton cellulaire autoclavé de masse volumique égale à 500-550 kg/m3.

Synthesis of phenobarbital {sup 14}C - 5 (1964); Synthese du phenobarbital {sup 14}C - 5 (1964)

Energy Technology Data Exchange (ETDEWEB)

Benakis, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Phenobarbital (Luminal), well known as a hypnotic agent, plays also an important role in the medical treatment of epilepsy. With the object of studying the metabolism of this medicament in the living system, the synthesis of phenobarbital marked in position 2 of the pyrimidinic ring has been effected. It has been necessary, in order to carry out to research into the metabolism of this product, to have a phenobarbital marked in position 5 of the pyrimidinic ring. This synthesis, making it possible to introduce C-14 into position 5 of the pyrimidinic ring, consists of seven stages starting from C-14 carboxyl benzoic acid having a specific activity of 25 mc/mM. The melting point of the final product is 172 - 173 deg. C and its specific activity is 11.15 mc/mM. The overall radioactive yield of the pure product, with respect to the original benzoic acid (10 mM) is of the order of 3 per cent. The purity of the product has been controlled by paper chromatography; it is of the order of 99 per cent. (author) [French] Le phenobarbital (Luminal) bien connu comme agent hypnotique, joue egalement un role important dans la medication anti-epileptique. Pour l'etude du metabolisme de ce medicament dans l'organisme vivant, nous avons synthetise le phenobarbital marque en position 2 du cycle pyrimidinique. Afin de poursuivre la recherche du metabolisme de ce produit, il a ete necessaire de disposer du phenobarbital marque en position 5 du cycle. pyrimidinique. Cette synthese, permettant l'introduction du {sup 14}C en position 5 du cycle pyrimidinique, comporte sept etapes, au depart de l'acide benzoique carboxyle {sup 14}C, d'une activite specifique de 25 mc/mM. Point de fusion du produit final: 172 - 173 deg. C Activite specifique: 11,15 mC/mM. Rendement total radioactif du produit pur, par rapport a l'acide benzoique de depart sur 10 mM, de l'ordre de 3 pour cent. La purete du produit a ete controlee par chromatographie sur papier; elle est de l'ordre de 99 pour cent. (auteur)

Effect of MoO3 addition on phase separation in borosilicate glasses

International Nuclear Information System (INIS)

Wakabayashi, Hajimu; Yamanaka, Hiroshi; Terai, Ryohei; Fukumoto, Shinji.

1987-01-01

The effect of MoO 3 addition on the phase separation of sodium borosilicate glasses has been studied by electron microscopic observation and electrical conductivity measurement. With increasing MoO 3 addition, the immiscibility temperatures rose, the growth rate of phase separation increased, and the immiscibility region in the Na 2 O-B 2 O 3 -SiO 2 system extended. When MoO 3 more than 5 mol% was added to the glasses, two stages of phase separation appeared ; one is metastable immiscibility, which takes place below the liquidus temperature, and the other is stable immiscibility, occurring above the liquidus temperature. The present experiment confirmed that the conductivity measurement of molten glasses is usefull to detect phase separation in the glasses, giving some suggestions for preventing the separation of molybdates in nuclear waste glasses and also for controlling the micro-pore sizes of porous glasses. (author)

Dynamique des populations du foreur des tiges du cacaoyer ...

African Journals Online (AJOL)

SARAH

30 nov. 2014 ... déprédateur dans la région du Haut-Sassandra, la deuxième plus grande région de production de cacao en. Côte d'ivoire. Méthodologie et résultats : L'étude a été réalisée de 2009 à 2013 dans les plantations villageoises de la région du Haut-Sassandra en Côte d'Ivoire. Les variations des taux d'attaques ...

La longue marche du mouvement sportif camerounais : l'émergence du Comité Olympique Camerounais (1946–1964

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Charitas Pascal

2016-01-01

Dans ces conditions et selon le statut particulier de ce territoire du « pré-carré » africain de la France, il s'agit de comprendre les étapes de l'institutionnalisation du sport camerounais au sein des atermoiements de la colonisation française puis les processus à l'œuvre dans l'émergence puis la création du Comité Olympique Camerounais (COC, symbole de l'émancipation du sport camerounais et marqueur de son intégration sur la scène sportive internationale, plus particulièrement olympique. Autrement dit, de 1946 et la mise sous tutelle par l'ONU du Cameroun français pour sa partie orientale à 1964 et la première participation du CNO du Cameroun aux Jeux olympiques de Tokyo, l'objectif est de saisir ici le passage d'un sport colonial à un sport postcolonial mettant en exergue le rôle de l'influence française et le rôle des cadres camerounais du secteur sportif.

Coordination Environments of Highly Charged Cations (Ti, Cr, and Light REE's) in Borosilicate Glass/Melts to 1120C

Energy Technology Data Exchange (ETDEWEB)

Farges, Francois; /Museum Natl. Hist. Natur. /Stanford U., Geo. Environ. Sci.; Brown, Gordon E., Jr.; /Stanford U., Geo. Environ Sci. /SLAC, SSRL

2007-01-02

The local environments around Ti, Cr, and several light rare-earth elements (La, Ce, and Nd) were investigated by in-situ XANES spectroscopy in a number of complex borosilicate glasses and melts (to 1120 C) that are used for nuclear waste storage. Examination of the high-resolution XANES spectra at the Ti K-edge shows that the average coordination of Ti changes from {approx}5 to {approx}4.5. Cr is dominantly trivalent in the melts studied. However, its average coordination is probably lower in the melt (tetrahedral ?) as revealed by the more intense Cr-K pre-edge feature. Ce also changes its average valence from dominantly +4 to +3.5 upon glass melting. These changes are reversible at T{sub g}, the glass transition temperature ({approx}500-550 C for these glasses). In contrast, the local environments of Nd, Pr, and La are unaffected by melting. Therefore, structural reorganization of these borosilicate glass/melts above T{sub g} is variable, not only in terms of valence (as for Ce) but also speciation (Ti and Cr). Both the ability of B to adopt various coordination geometries (triangular and tetrahedral) and the chemical complexity of the glass/melts explain these changes.

Sådan kan du bruge optioner og futures

DEFF Research Database (Denmark)

Kohl, Niklas

2017-01-01

Masterclass. Har du brug for at forsikre værdierne i din portefølje i en periode, hvor du forventer stor uro på finansmarkederne, kan du gøre det med optioner eller futures. Her kan du læse om de forskellige typer – og om de muligheder de giver dig.......Masterclass. Har du brug for at forsikre værdierne i din portefølje i en periode, hvor du forventer stor uro på finansmarkederne, kan du gøre det med optioner eller futures. Her kan du læse om de forskellige typer – og om de muligheder de giver dig....

Paysans du Brésil

Directory of Open Access Journals (Sweden)

Dominique Temple

2007-01-01

Full Text Available Eric Sabourin, « Paysans du Brésil : Entre échange marchand et réciprocité » Paris, Editions Quae, 241p, 30 euros, (préface de Maxime Haubert, 2007Dans la présentation du livre, Maxime Haubert dit :«Cet ouvrage propose une analyse socio-anthropologique et agronomique des sociétés rurales et paysannes du Brésil et des transformations qu'elles ont connues ces dernières décennies, en particulier face aux interventions de l'Etat et à l'expansion du marché capitaliste (.... «Le livre pose d'abor...

Raman and X-ray absorption spectroscopic studies of hydrothermally altered alkali-borosilicate nuclear waste glass

Energy Technology Data Exchange (ETDEWEB)

McKeown, David A., E-mail: davidm@vsl.cua.ed [Vitreous State Laboratory, Catholic University of America, 620 Michigan Ave., N.E., Washington, DC 20064 (United States); Buechele, Andrew C.; Viragh, Carol; Pegg, Ian L. [Vitreous State Laboratory, Catholic University of America, 620 Michigan Ave., N.E., Washington, DC 20064 (United States)

2010-04-01

Raman spectroscopy and X-ray absorption spectroscopy (XAS) are used to characterize structural changes that took place in hydrothermally altered (Na,K)-alumina-borosilicate glasses with different Na/K ratios, formulated as part of a durability study to investigate the behavior of glasses for nuclear waste storage. The hydrothermal experiments, or vapor hydration tests (VHT), were performed on each glass for 3 and 20 days at 200 deg. C to accelerate and approximate long-term alteration processes that may occur in a nuclear waste repository. Results found for both glasses and their VHT altered counterparts show little, if any, structural influence from the different starting Na/K ratios. X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and Raman spectroscopy indicate that the altered samples are mostly amorphous with small amounts of analcime-like and leucite-like crystals within 200 mum of the sample surface and contain up to 9.7 wt.% water or OH. The Raman data are nearly identical for the amorphous portions of all altered VHT samples investigated, and indicate that two glass structural changes took place during alteration: one, partial depolymerization of the alumina-borosilicate network, and two, introduction of water or OH. Al and Si XAS data indicate tetrahedral AlO{sub 4} and SiO{sub 4} environments in the original glasses as well as in the altered samples. Small energy shifts of the Si K-edge also show that the altered VHT samples have less polymerized networks than the original glass. Na XAS data indicate expanded Na environments in the VHT samples with longer Na-O distances and more nearest-neighbor oxygen atoms, compared with the original glasses, which may be due to hydrous species introduced into the expanding Na-sites.

Comparison of radiation and quenching rate effects on the structure of a sodium borosilicate glass

International Nuclear Information System (INIS)

Peuget, Sylvain; Maugeri, Emilio-Andrea; Mendoza, Clement; Fares, Toby; Bouty, Olivier; Jegou, Christophe; Charpentier, Thibault; Moskura, Melanie

2013-01-01

The effects of quenching rate and irradiation on the structure of a sodium borosilicate glass were compared using 29 Si, 11 B, and 23 Na nuclear magnetic resonance and Raman spectroscopy. Quenching rate ranging from 0.1 to 3 * 10 4 K min -1 was studied. Various irradiation conditions were performed, i.e. gold-ion irradiation in a multi-energy mode (from 1 to 6.75 MeV), and Kr and Xe ion irradiations with energy of 74 and 92 MeV, respectively. In pile irradiation with thermal neutron flux was performed as well, to study the effect of alpha radiation from the nuclear reaction 10 B(n,α) 7 Li. Both irradiation and high quenching rate induce similar local order modification of the glass structure, mainly a decrease of the mean boron coordination and an increase of Q 3 units. Nevertheless, the variations observed under irradiation are more pronounced than the ones induced by the quenching rate. Moreover, some important modifications of the glass medium range order, i.e. the emergence of the D2 band associated to three members silica rings and a modification of the Si-O-Si angle distribution were only noticed after irradiation. These results suggest that the irradiated structure is certainly not exactly the one obtained by a rapidly quenched equilibrated melt, but rather a more disordered structure that was weakly relaxed during the very rapid quenching phase following the energy deposition step. Raman spectroscopy showed a similar irradiated structure whereas the glass evolutions were controlled by the electronic energy loss in the ion track formation regime for Kr-ion irradiation or by the nuclear energy loss for Au and OSIRIS irradiation. The similar irradiated structure despite different irradiation routes, suggests that the final structural state of this sodium borosilicate glass is mainly controlled by the glass reconstruction after the energy deposition step. (authors)

Communication du Service juridique et du Département HR à l'attention des membres du personnel domiciliés en France

CERN Multimedia

HR Department

2007-01-01

Déclaration de revenus 2006 Les membres du personnel trouveront ci-après les informations nécessaires sur la manière de remplir la déclaration de revenus 2006, qui doit être retournée au plus tard le 31 mai 2007. Qui doit remplir la déclaration? Comment l'obtenir? Tous les membres du personnel1) domiciliés en France2), qu'ils soient ou non de nationalité française, doivent remplir la déclaration de revenus 2006 sur la base des présentes instructions et la renvoyer signée, au plus tard le 31 mai 2007, au centre des impôts de leur domicile. Les membres du personnel devraient recevoir la déclaration de revenus 2006 fin avril - début mai. Ceux qui ne la recevraient pas directement devront la retirer au centre des impôts, à la trésorerie ou à la mairie de leur domicile ou bien encore la télécharger sur le site internet du Ministère des Finances (www.finances.gouv.fr). Comment remplir la déclaration Les membres du personnel doivent remplir la DECLARATION PAPIER uniquement. Dé...

Infrared and x-ray photoelectron spectroscopic studies on sodium borosilicate glass interacted with thermally oxidized aluminides formed on alloy 690

International Nuclear Information System (INIS)

Yusufali, C.; Dutta, R.S.; Dey, G.K.; Kshirsagar, R.J.; Jagannath; Mishra, R.K.

2012-01-01

Thermally oxidized aluminides formed on Ni-Cr-Fe based superalloy 690 substrates were subjected to interaction with sodium borosilicate melt (used as matrices for immobilization of high-level radioactive liquid waste) at 1248 K for 192 hours. After the interaction, Fourier-transform infrared (FT-IR) spectroscopy analysis of glass samples indicated the incorporation of Al in the glass network. X-ray photoelectron spectroscopy (XPS) of glass specimens revealed modified glass structure. (author)

Determination of iron redox ratio in borosilicate glasses and melts from Raman spectra

Energy Technology Data Exchange (ETDEWEB)

Cochain, B. [SCDV-Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols-sur-ceze (France); Physique des Mineraux et des Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris Cedex05 (France); Neuville, D.R.; Richet, P. [Physique des Mineraux et des Magmas, CNRS-IPGP, 4 place Jussieu, 75252 Paris Cedex05 (France); Henderson, G.S. [Dept of Geology, University of Toronto, 22 Russell Street, Toronto (Canada); Pinet, O. [SCDV-Laboratoire d' Etudes de Base sur les Verres, CEA Valrho, Centre de Marcoule, 30207 Bagnols-sur-ceze (France)

2008-07-01

A method is presented to determine the redox ratio of iron in borosilicate glasses and melts relevant to nuclear waste storage from an analysis of Raman spectra recorded at room or high temperature. The basis of this method is the strong variation of the spectral feature observed between 800 and 1200 cm{sup -1}, in which it is possible to assign a band to vibrational modes involving ferric iron in tetrahedral coordination whose intensity increases with iron content and iron oxidation. After baseline correction and normalization, fits to the Raman spectra made with Gaussian bands enable us to determine the proportion of ferric iron provided the redox ratio is known independently for at least two redox states for a given glass composition. This method is particularly useful for in situ determinations of the kinetics and mechanisms of redox reactions. (authors)

Determination of iron redox ratio in borosilicate glasses and melts from Raman spectra

International Nuclear Information System (INIS)

Cochain, B.; Neuville, D.R.; Richet, P.; Henderson, G.S.; Pinet, O.

2008-01-01

A method is presented to determine the redox ratio of iron in borosilicate glasses and melts relevant to nuclear waste storage from an analysis of Raman spectra recorded at room or high temperature. The basis of this method is the strong variation of the spectral feature observed between 800 and 1200 cm -1 , in which it is possible to assign a band to vibrational modes involving ferric iron in tetrahedral coordination whose intensity increases with iron content and iron oxidation. After baseline correction and normalization, fits to the Raman spectra made with Gaussian bands enable us to determine the proportion of ferric iron provided the redox ratio is known independently for at least two redox states for a given glass composition. This method is particularly useful for in situ determinations of the kinetics and mechanisms of redox reactions. (authors)

26 Calcul multi-caractéristique du coût du non-qualité via la fonction ...

African Journals Online (AJOL)

PR BOKO

Le coût du non - qualité (CNQ) est un indicateur permettant l'estimation de la marge ..... multicritères de Taguchi en fonction de l'évolution du poids et capacité du ... A Scheduling Example; International Journal of Information and Management.

Cartes infographiques du Symposium Afrique de l'Ouest et du Centre

International Development Research Centre (IDRC) Digital Library (Canada)

fdieudonne

VILLES SÛRES ET INCLUSIVES | AFRIQUE DE L'OUEST ET DU CENTRE. Spécificités de violence, d'exclusion, et de lutte contre la criminalité. République démocratique du Congo: Taux de natalité par femme, en moyenne 10 enfants, très élevé. Exclusion sociale exacerbée : des jeunes enfants accusés de sorcellerie.

Composition-Structure-Property Relations of Compressed Borosilicate Glasses

Science.gov (United States)

Svenson, Mouritz N.; Bechgaard, Tobias K.; Fuglsang, Søren D.; Pedersen, Rune H.; Tjell, Anders Ø.; Østergaard, Martin B.; Youngman, Randall E.; Mauro, John C.; Rzoska, Sylwester J.; Bockowski, Michal; Smedskjaer, Morten M.

2014-08-01

Hot isostatic compression is an interesting method for modifying the structure and properties of bulk inorganic glasses. However, the structural and topological origins of the pressure-induced changes in macroscopic properties are not yet well understood. In this study, we report on the pressure and composition dependences of density and micromechanical properties (hardness, crack resistance, and brittleness) of five soda-lime borosilicate glasses with constant modifier content, covering the extremes from Na-Ca borate to Na-Ca silicate end members. Compression experiments are performed at pressures ≤1.0 GPa at the glass transition temperature in order to allow processing of large samples with relevance for industrial applications. In line with previous reports, we find an increasing fraction of tetrahedral boron, density, and hardness but a decreasing crack resistance and brittleness upon isostatic compression. Interestingly, a strong linear correlation between plastic (irreversible) compressibility and initial trigonal boron content is demonstrated, as the trigonal boron units are the ones most disposed for structural and topological rearrangements upon network compaction. A linear correlation is also found between plastic compressibility and the relative change in hardness with pressure, which could indicate that the overall network densification is responsible for the increase in hardness. Finally, we find that the micromechanical properties exhibit significantly different composition dependences before and after pressurization. The findings have important implications for tailoring microscopic and macroscopic structures of glassy materials and thus their properties through the hot isostatic compression method.

Antagonist effects of calcium on borosilicate glass alteration

Energy Technology Data Exchange (ETDEWEB)

Mercado-Depierre, S. [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France); Angeli, F., E-mail: frederic.angeli@cea.fr [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France); Frizon, F. [CEA Marcoule, DTCD SECM LP2C, 30207 Bagnols sur Cèze (France); Gin, S. [CEA Marcoule, DTCD SPDE LCLT, 30207 Bagnols sur Cèze (France)

2013-10-15

Graphical abstract: Display Omitted -- Highlights: •Kinetic study of glass alteration is investigated in calcium-enriched solutions. •New insights into silicon–calcium interactions in glass/cement systems are proposed. •Glass alteration is controlled by pH, Ca concentration and reaction progress. •Evidence of antagonist effects according to the importance of these parameters. -- Abstract: Numerous studies have been conducted on glass and cement durability in contact with water, but very little work to date has focused directly on interactions between the two materials. These interactions are mostly controlled by silicon–calcium reactivity. However, the physical and chemical processes involved remain insufficiently understood to predict the evolution of coupled glass–cement systems used in several industrial applications. Results are reported from borosilicate glass alteration in calcium-rich solutions. Our data show that four distinct behaviors can be expected according to the relative importance of three key parameters: the pH, the reaction progress (short- or long-term alteration) and the calcium concentration. Glass alteration is thus controlled by specific mechanisms depending on the solution chemistry: calcium complexation at the glass surface, precipitation of calcium silicate hydrates (C–S–H) or calcium incorporation in the altered layer. These findings highlight the impact of silicon–calcium interactions on glass durability and open the way for a better understanding of glass–cement mixing in civil engineering applications as well as in nuclear waste storage.

Antagonist effects of calcium on borosilicate glass alteration

International Nuclear Information System (INIS)

Mercado-Depierre, S.; Angeli, F.; Frizon, F.; Gin, S.

2013-01-01

Graphical abstract: Display Omitted -- Highlights: •Kinetic study of glass alteration is investigated in calcium-enriched solutions. •New insights into silicon–calcium interactions in glass/cement systems are proposed. •Glass alteration is controlled by pH, Ca concentration and reaction progress. •Evidence of antagonist effects according to the importance of these parameters. -- Abstract: Numerous studies have been conducted on glass and cement durability in contact with water, but very little work to date has focused directly on interactions between the two materials. These interactions are mostly controlled by silicon–calcium reactivity. However, the physical and chemical processes involved remain insufficiently understood to predict the evolution of coupled glass–cement systems used in several industrial applications. Results are reported from borosilicate glass alteration in calcium-rich solutions. Our data show that four distinct behaviors can be expected according to the relative importance of three key parameters: the pH, the reaction progress (short- or long-term alteration) and the calcium concentration. Glass alteration is thus controlled by specific mechanisms depending on the solution chemistry: calcium complexation at the glass surface, precipitation of calcium silicate hydrates (C–S–H) or calcium incorporation in the altered layer. These findings highlight the impact of silicon–calcium interactions on glass durability and open the way for a better understanding of glass–cement mixing in civil engineering applications as well as in nuclear waste storage

Tc and Re Behavior in Borosilicate Waste Glass Vapor Hydration Tests

International Nuclear Information System (INIS)

McKeown, David A.; Buechele, Andrew C.; Pegg, Ian L.; Lukens, Wayne W.; Shuh, David K.

2007-01-01

Technetium (Tc), found in some nuclear wastes, is of particular concern with regard to long-term storage, because of its long-lived radioactivity and high mobility in the environment. Tc and rhenium (Re), commonly used as a non-radioactive surrogate for Tc, were studied to assess their behavior in borosilicate glass under hydrothermal conditions in the Vapor Hydration Test (VHT). X-ray absorption spectroscopy (XAS) and scanning electron microscopy (SEM) measurements were made on the original Tc- and Re-containing glasses and their corresponding VHT samples, and show different behavior for Tc and Re under VHT conditions. XAS indicates that, despite starting with different Tc(IV) and Tc(VII) distributions in each glass, the VHT samples have 100% Tc(IV)O 6 environments. SEM shows complete alteration of the original glass, Tc enrichment near the sample surface, and Tc depletion in the center. Perrhenate (Re(VII)O 4 - ) is dominant in both Re-containing samples before and after the VHT, where Re is depleted near the VHT sample surface and more concentrated toward the center. (authors)

Protéger les collectivités côtières du nord du Maroc | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

3 févr. 2011 ... Élévation du niveau de la mer, ondes de tempête, inondations littorales : les ... Un plan d'action en matière de gestion intégrée du littoral et une nouvelle ... du territoire sans recourir à un guide de la dynamique du milieu côtier. ... local, et encore moins de contrôle sur les terres dont elles sont tributaires.

Heat accumulation during high repetition rate ultrafast laser interaction: Waveguide writing in borosilicate glass

International Nuclear Information System (INIS)

Zhang, Haibin; Eaton, Shane M; Li, Jianzhao; Herman, Peter R

2007-01-01

During high repetition rate (>200 kHz) ultrafast laser waveguide writing, visible heat modified zones surrounding the formed waveguide occur as a result of heat accumulation. The radii of the heat-modified zones increase with the laser net fluence, and were found to correlate with the formation of low-loss and cylindrically symmetric optical waveguides. A numerical thermal model based on the finite difference method is applied here to account for cumulative heating and diffusion effects. The model successfully shows that heat propagation and accumulation accurately predict the radius of the 'heat modified' zones observed in borosilicate glass waveguides formed across a wide range of laser exposure conditions. Such modelling promises better control of thermal effects for optimizing the fabrication and performance of three-dimensional optical devices in transparent materials

Effets du travail du sol sur le comportement chimique et biologique ...

African Journals Online (AJOL)

SARAH

31 juil. 2017 ... RESUME. Objectif : L'objectif de cette étude est de comparer les effets de six techniques culturales de mise en place du blé tendre sur certaines propriétés chimiques et biologiques du sol et les conséquences sur le rendement grain et ses composantes dans la région «non chernozem» en 7ème années ...

Coordonnateur du bureau d'assistance | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

Résumé des fonctions. En tant que membre de l'équipe du Bureau d'assistance au sein de la Section du service à la clientèle (SSC), le coordonnateur du Bureau d'assistance offre au personnel du Centre et aux autres utilisateurs reconnus des installations TI du Centre un soutien de première ligne en matière d'utilisation ...

Lettre ouverte au Président du Conseil du CERN

CERN Document Server

Association du personnel

2010-01-01

Genève, le 1er février 2010 Monsieur le Président, Les membres de la Caisse de pensions, actifs et pensionnés, sont à la fois très inquiets et indignés par la manière avec laquelle le Conseil traite la question, devenue alarmante, de l’équilibre de la Caisse. Dès 2004 en effet, l’étude actuarielle avait alerté le Conseil au sujet du déficit technique du régime et de l’insuffisance du financement de son plan de prestations. Le Conseil s’est alors contenté de mettre en place un mécanisme de sous indexation des pensions – arbitraire et discriminatoire dans la mesure où il ne fait appel qu’à la solidarité des pensionnés – et de décider une augmentation minime des contributions à la Caisse, une mesurette ...

Linear thermal expansion coefficient (at temperatures from 130 to 800 K) of borosilicate glasses applicable for coupling with silicon in microelectronics

OpenAIRE

Sinev, Leonid S.; Petrov, Ivan D.

2017-01-01

Processing results of measurements of linear thermal expansion coefficients and linear thermal expansion of two brands of borosilicate glasses --- LK5 and Borofloat 33 --- are presented. The linear thermal expansion of glass samples have been determined in the temperature range 130 to 800 K (minus 143 to 526 $\\deg$C) using thermomechanical analyzer TMA7100. Relative imprecision of indirectly measured linear thermal expansion coefficients and linear thermal expansion of both glass brands is le...

Ved du, hvad der er i dine varer, når du handler?

DEFF Research Database (Denmark)

Phillip, Anja; Smith, Viktor

2016-01-01

I supermarkedet på vej hjem køber du ind til madpakken. Ved kølemontren med pålæg ser du en pakke Gårdlykke Hønsesalat. ... Måske vælger du den uden at tænke nærmere over hvorfor, eller fordi emballagen og navnet får hønsesalaten til at fremstå lokal, hjemmelavet eller økologisk. ... Alt dette ba...... bakkes op af resultaterne fra årelang forskning på CBS, hvor universitetets forskergruppe Fair-Speak har undersøgt emballagernes måde at påvirke forbrugerne til at købe produktet....

Étude de la qualité des eaux usées des deux retenues du bassin du ...

African Journals Online (AJOL)

SARAH

31 mai 2017 ... Gourou au carrefour de l'Indénié à Abidjan en 2012. 11138. Journal of Applied .... retenues sont nées du projet de gestion intégrée du bassin du Gourou (CI-FAD, ..... Contrôle de la qualité microbiologique des eaux usées ...

fibrosarcome du larynx

African Journals Online (AJOL)

pie du lit tumoral est employée comme complément thé- rapeutique [9] alors que la chimiothérapie est générale- ment indiquée dans les formes métastatiques. Le pronos- tic dépend essentiellement du degré de différentiation his- tologique. En fait, le fibrosarcome bien différencié est caractérisé par la fréquence de récidive ...

Au fil du temps (1976 ou la loi du seuil

Directory of Open Access Journals (Sweden)

Isabelle Singer

2010-04-01

Full Text Available Ayant choisi de vivre dans un camion, les héros d’Au fil du temps (film de Wim Wenders de 1976 font du seuil une expérience particulière. Celle de la rupture avec toute idée de foyer et celle du refus d’appartenance à la terre natale, cette terre allemande traversée par une frontière le long de laquelle ils vont voyager, et qui les renvoie à chaque instant aux traumatismes de l’Histoire. Sur le pare-brise du camion, l’extérieur (campagnes indifférenciées, villes à l’abandon… et l’intérieur se superposent. Au fil du temps questionne le paysage : il s’agit d’en décoller un à un les mythes qui le recouvrent. L’image alors n’est plus surface mais volume à traverser, à lacérer et découvrir ce qui est tissé dans le paysage. La démarche de Wenders est alors proche de celle d’un de ses contemporains : Anselm Kiefer. Le paysage allemand provoque le rejet parce qu’il y a là toujours plus que le visible : des strates et des strates de culpabilité que le mythe - et c’est sa fonction - a recouvert. Et qu’il s’agira ici, de soulever. Le choix du nomadisme, c’est celui d’un état de l’humanité antérieur à l’idée de patrie. Et c’est aussi celui de la solitude, comme prix à payer à ce refus d’appartenance et à cette mise à jour des mythes. L’appartenance à la terre allemande et à son Histoire est profondément problématique parce que les pères sont fondamentalement coupables. On se reconnaîtra alors des pères de substitution : des pères de cinéma (Nicholas Ray ou Fritz Lang. Et l’on substituera l’Histoire du cinéma à l’Histoire. Bruno est réparateur ambulant de projecteurs et Au fil du temps dressera, au gré de ses pérégrinations, un état des lieux du cinéma allemand des années soixante-dix : déliquescent, colonisé par les images hollywoodiennes. Il faut que cela change : état du cinéma ; état des protagonistes solitaires en quête d’une identit

Hausse du niveau des océans et perte de terres dans le delta du Nil ...

International Development Research Centre (IDRC) Digital Library (Canada)

9 juin 2016 ... Au moyen de systèmes d'information géographique (SIG), des chercheurs subventionnés par le CRDI ont déterminé les zones littorales du delta du Nil qui pourraient être touchées par la hausse du niveau des océans. Il pourrait en résulter d'importantes pertes de terres d'ici 2100. Selon les plus récentes ...

Les mots du jazz

OpenAIRE

Roueff, Olivier

2007-01-01

L’ouvrage d’André Schaeffner constitue la première analyse savante du jazz (1926). Il a marqué une étape importante dans le processus de réinvention du jazz en France en contribuant notamment, par sa réception et les polémiques qu’il a suscitées, à transformer l’identification du jazz d’une musique « américaine » à une musique « noire-américaine » (c’est-à-dire aux « racines » africaines). Les analyses proposées dans cet ouvrage, alors qu’elles désignaient des musiques que la critique de jazz...

23 octobre 2012 - Le Président du Conseil général de la Haute-Savoie C. Monteil signe le livre d'or en présence du Directeur général R. Heuer, la chef des Relations Internationales F. Pauss, le chef du département Physique P. Bloch et le chef du département Technologie F. Bordry; visite du hall de test des aimants supraconducteurs du LHC avec F. Bordry.

CERN Multimedia

Maximilien Brice

2012-01-01

23 octobre 2012 - Le Président du Conseil général de la Haute-Savoie C. Monteil signe le livre d'or en présence du Directeur général R. Heuer, la chef des Relations Internationales F. Pauss, le chef du département Physique P. Bloch et le chef du département Technologie F. Bordry; visite du hall de test des aimants supraconducteurs du LHC avec F. Bordry.

Upconversion studies of Er3+/Yb3+ doped SrO.TiO2 borosilicate glass ceramic system

International Nuclear Information System (INIS)

Maheshwari, Aditya; Om Prakash; Kumar, Devendra; Rai, S.B.

2011-01-01

Upconversion behaviour has been studied in various matrices and fine powders of SrTiO 3 by previous workers. In present work, Er 3+ /Yb 3+ were doped in appropriate ratio in SrO.TiO 2 borosilicate glass ceramic system to study the upconversion phenomenon. Dielectric properties of this class of glass ceramic system have been extensively investigated by Thakur et al. It has been observed that both upconversion efficiency and dielectric constant increases with transformation of glass into glass ceramic. Therefore, present investigation is based upon the study of optical as well as the electrical properties of same glass ceramic system. In order to prepare different crystalline matrices, two different Er 3+ /Yb 3+ :SrO.TiO 2 borosilicate glasses with same amount of Er 2 O 3 and Yb 2 O 3 were prepared by melt quench method. Glasses were transparent with light-wine colour. Glass ceramics were prepared from the glasses by heat treatment based on DTA (Differential thermal analysis) results. Glass ceramics were fully opaque with brownish-cream colour. Powder X-ray diffraction (XRD) patterns confirmed that two different crystalline matrices, Sr 3 Ti 2 O 7 , Ti 10 O 19 and SrTiO 3 , TiO 2 were present in two glass ceramic samples respectively. Luminescence properties of glass and glass ceramic samples with 976nm laser irradiation showed that the intensities of the green and red emission increased multiple times in glass ceramic than that of the glass. Possible mechanisms responsible for upconversion eg. Energy Transfer (ET) and Excited State Absorption (ESA), were studied through laser pumping power log dependence

Les outils du CERN

CERN Multimedia

1999-01-01

C'est le plus grand centre mondial de recherche en physique des particules. Les outils du Laboratoire, accélérateurs et détecteurs de particules, figurent parmi les instruments scientifiques les plus complexes au monde. Des prix Nobels ont d'ailleurs été attribués aux physiciens du CERN pour leurs développements.

Évaluation du nouveau programme d'études du College of Health ...

International Development Research Centre (IDRC) Digital Library (Canada)

Ces changements étaient jugés nécessaires pour préparer les professionnels de la santé aux nouvelles exigences de la prestation de services de santé décentralisés, pour juguler les nouvelles pandémies comme celles du VIH/sida et du virus Ébola, ainsi que pour répondre aux besoins des malades dans les zones ...

Thermal decomposition of biphenyl (1963); Decomposition thermique du biphenyle (1963)

Energy Technology Data Exchange (ETDEWEB)

Clerc, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-06-15

The rates of formation of the decomposition products of biphenyl; hydrogen, methane, ethane, ethylene, as well as triphenyl have been measured in the vapour and liquid phases at 460 deg. C. The study of the decomposition products of biphenyl at different temperatures between 400 and 460 deg. C has provided values of the activation energies of the reactions yielding the main products of pyrolysis in the vapour phase. Product and Activation energy: Hydrogen 73 {+-} 2 kCal/Mole; Benzene 76 {+-} 2 kCal/Mole; Meta-triphenyl 53 {+-} 2 kCal/Mole; Biphenyl decomposition 64 {+-} 2 kCal/Mole; The rate of disappearance of biphenyl is only very approximately first order. These results show the major role played at the start of the decomposition by organic impurities which are not detectable by conventional physico-chemical analysis methods and the presence of which accelerates noticeably the decomposition rate. It was possible to eliminate these impurities by zone-melting carried out until the initial gradient of the formation curves for the products became constant. The composition of the high-molecular weight products (over 250) was deduced from the mean molecular weight and the dosage of the aromatic C - H bonds by infrared spectrophotometry. As a result the existence in tars of hydrogenated tetra, penta and hexaphenyl has been demonstrated. (author) [French] Les vitesses de formation des produits de decomposition du biphenyle: hydrogene, methane, ethane, ethylene, ainsi que des triphenyles, ont ete mesurees en phase vapeur et en phase liquide a 460 deg. C. L'etude des produits de decomposition du biphenyle a differentes temperatures comprises entre 400 et 460 deg. C, a fourni les valeurs des energies d'activation des reactions conduisant aux principaux produits de la pyrolyse en phase vapeur. Produit et Energie d'activation: Hydrogene 73 {+-} 2 kcal/Mole; Benzene 76 {+-} 2 kcal/Mole; Metatriphenyle, 53 {+-} 2 kcal/Mole; Decomposition du biphenyle 64 {+-} 2 kcal/Mole; La

L’écriture du temps dans Robinson Crusoe

OpenAIRE

Bulckaen, Denise

2018-01-01

“Le récit est une séquence deux fois temporelle... il y a le temps de la chose-racontée et le temps du récit (temps du signifié et temps du signifiant)”. Cette citation se trouve au début du chapitre que Genette consacre à “Ordre” dans Figures III. Elle s'applique à de nombreux romans, mais elle est particulièrement intéressante quand on considère le roman de forme autobiographique. Le décalage entre “le temps du signifié” et “le temps du signifiant” est plus ou moins grand selon les romans. ...

Établissements recevant du public

CERN Document Server

2014-01-01

Synthèse pour les installations électriques, des règles de sécurité contre les risques d’incendie et de panique dans les établissements recevant du public (ERP), selon l’arrêté du 25 juin 1980 modifié. L'ouvrage traite à la fois des dispositions communes aux établissements du 1er groupe (1ère à 4ème catégorie), du 2ème groupe (5ème catégorie) et des règles particulières applicables aux différents types d'établissements (structures d'accueil pour personnes âgées ou handicapées, hôtels, magasins de vente, restaurants et débit de boisson, établissements de soins, administration, châpiteaux, etc...) Sont ainsi notamment traités, dans le cadre des dispositions communes aux établissements du 1er groupe, pour les installations électriques normales : les installations des appareils, tableaux et canalisations, les locaux électriques et installation de machines, l'éclairage normal des locaux accessibles au public, le chauffage et la ventilation, l'installation d'eau chaude sanita...

Standardization of a PIGE methodology for simultaneous quantification of low Z elements in barium borosilicate glass samples

International Nuclear Information System (INIS)

Chhillar, S.; Acharya, R.; Dasari, K.B.; Pujari, P.K.; Mishra, R.K.; Kaushik, C.P.

2013-01-01

In order to standardize particle induced gamma-ray emission (PIGE) methodology for simultaneous quantification of light elements, analytical sensitivities of Li, F, B, Na, Al and Si were evaluated using 4 MeV proton beam ( ∼ 10 nA current) using 3 MV Pelletron at IOP, Bhubaneswar. The PIGE method was validated by determining all six elements in a synthetic sample in graphite matrix and applied to two barium borosilicate glass (BaBSG) samples. The prompt γ-rays emitted from inelastic scattering or nuclear reactions of corresponding isotopes were measured using a 60% HPGe coupled to MCA and the current normalized count rates were used for concentration calculation. (author)

du Chott Marouane

African Journals Online (AJOL)

plancton de 90 µm de vide de maille. Ils ont été conservés dans du formol à 5%. L'identification de l'espèce est basée sur des critères morphologiques [20]: la forme des furcas, les lobes frontaux des antennes des mâles, de l'organe copulateur (pénis) et du sac ovigère. Le comptage des soies furcales a été réalisé. L'étude ...

OGM : vers une définition commune du contenu du problème ?

Directory of Open Access Journals (Sweden)

Icart Jean-Claude

2001-07-01

Full Text Available Les divergences croissantes depuis des années entre experts, responsables économiques, et acteurs sociaux et « citoyens » au sujet des OGM, ont pu être analysées à juste titre, comme exprimant la difficulté de dégager une « définition commune du contenu du problème »1.

L’Association du personnel (AP) en réunion du Directorat élargi (ED) !

CERN Multimedia

Staff Association

2017-01-01

Le 3 avril dernier, la Vice-Présidente et le Président de l’Association du personnel ont présenté en réunion du Directorat élargi (Directeurs et Chefs de départements et d’unités) le plan des activités de l’Association du personnel pour 2017 et ont fait part des préoccupations de l’AP. Cinq sujets ont été abordés en commençant par la mise en œuvre des décisions prises dans le cadre de l’examen quinquennal de 2015. Examen quinquennal – suivi (voir Echo n° 257) 2016 – Principales mises en œuvre De nombreux changements ont déjà été mis en place en 2016 : Révision des Statut et Règlement du personnel en janvier 2016, pour les aspects de diversité, et en septembre 2016, pour la ...

Role of IGF-1/IGF-1R in regulation of invasion in DU145 prostate cancer cells

Directory of Open Access Journals (Sweden)

Setya Hemani

2008-07-01

Full Text Available Abstract Background Prostate cancer progression to androgen independence is the primary cause of mortality by this tumor type. The IGF-1/IGF-1R axis is well known to contribute to prostate cancer initiation, but its contribution to invasiveness and the downstream signalling mechanisms that are involved are unclear at present. Results We examined the invasive response of androgen independent DU145 prostate carcinoma cells to IGF-1 stimulation using Matrigel assays. We then examined the signaling mechanisms and protease activities that are associated with this response. IGF-1 significantly increased the invasive capacity of DU145 cells in vitro, and this increase was inhibited by blocking IGF-1R. We further demonstrated that specific inhibitors of the MAPK and PI3-K pathways decrease IGF-1-mediated invasion. To determine potential molecular mechanisms for this change in invasive capacity, we examined changes in expression and activity of matrix metalloproteinases. We observed that IGF-1 increases the enzymatic activity of MMP-2 and MMP-9 in DU145 cells. These changes in activity are due to differences in expression in the case of MMP-9 but not in the case of MMP-2. This observation is corroborated by the fact that correlated changes of expression in a regulator of MMP-2, TIMP-2, were also seen. Conclusion This work identifies a specific effect of IGF-1 on the invasive capacity of DU145 prostate cancer cells, and furthermore delineates mechanisms that contribute to this effect.

La moralité implicite du marché

Directory of Open Access Journals (Sweden)

Pierre-Yves Néron

2010-05-01

Full Text Available In this article, I put forward an approach to business ethics that focuses on the notion of “implicit morality of the market”. I therefore try to identify the main components of this implicit morality of the market and expose the advantages of taking such a stance to think about the obligations of firms. In order to do so, I try to shed some light, drawing on recent works by Joseph Heath, on the potential normative role of the concept of market failures as articulated in economic theory. I finish by examining three problems that this approach is facing.RÉSUMÉDans cet article, je mets en avant une approche de l’éthique du commerce centrée sur la notion de « moralité implicite du marché ». J’essaie d’identifier les grands traits de cette moralité impli- cite du marché en plus d’exposer les avantages d’adopter une telle approche pour penser les obli- gations des firmes. Pour ce faire, je tente, en m’inspirant de travaux récents de Joseph Heath, de mettre en lumière le rôle proprement normatif que peut jouer le concept de défaillances des mar- chés tel que développé dans la théorie économique. Je termine en examinant trois problèmes auxquels fait face l’approche proposée ici.

Les Cahiers du CREAD

African Journals Online (AJOL)

Admin

6 juil. 2007 ... La problématique du développement du secteur de l'artisanat en. Algérie a été très peu abordée par les chercheurs, qu'ils soient universitaires ou .... La loi a institué une taxe d'apprentissage dont le taux a été fixé à. 1% de la ...

Consolidation du leadership en recherche en écosanté en Asie du ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 juin 2016 ... Financée par le CRDI, l'Initiative de renforcement du leadership en recherche en écosanté en Asie du Sud‑Est appuie l'exécution, dans la région, de travaux de recherche qui visent à permettre de mieux comprendre les effets de la transformation de l'agriculture sur les écosystèmes et sur la santé humaine ...

Le Silurien du Synclinorium de Moncorvo (NE du Portugal): Biostratigraphie et Importance Paléogéographique

Czech Academy of Sciences Publication Activity Database

Sarmiento, G. N.; Picarra, J. M.; Rebelo, J. A.; Robardet, M.; Gutiérrez-Marco, J. C.; Štorch, Petr; Rábano, I.

1999-01-01

Roč. 32, č. 5 (1999), s. 749-767 ISSN 0016-6995 R&D Projects: GA AV ČR Projects 351 et 421 du Programme International de Corrélation Géologique et au Projet Iberian Variscides du programme Europrobe, Projet 061-B0 du Programme de Coopération Scientifique et Technique Franco-Portugais Subject RIV: DB - Geology ; Mineralogy Impact factor: 0.736, year: 1999

Le Flaubert de Charles Du Bos

Directory of Open Access Journals (Sweden)

Jacques Neefs

2009-01-01

Full Text Available Charles Du Bos a porté une attention constante à l’œuvre de Flaubert (à l’exclusion de Bouvard et Pécuchet qui semble ne pas exister pour lui, à Madame Bovary et à L’Éducation sentimentale en particulier. La mise en relation de son étude : « Sur le milieu intérieur chez Flaubert », écrite en 1921, avec des textes du Journal de 1923 et de 1937, les rapprochements avec Gogol, Thomas Hardy, Tolstoï, Baudelaire, Henry James qui traversent les écrits de Du Bos, permettent de suivre ce que celui-ci décrit comme « l’expérience spirituelle » d’une matérialité comprise dans la conquête de la triple exigence du Beau, du Vivant et du Vrai. Du Bos décèle la force de l’œuvre de Flaubert dans la « disproportion » du style, et dans la puissance d’absorption qui fait la densité de cette prose, et qui désigne un extraordinaire travail de conversion. L’obscure expérience spirituelle ainsi poursuivie est celle d’un absolu de l’art, expérience paradoxale d’un « mystique qui ne croit à rien » (comme se désignait Flaubert lui-même, que le critique lie à une interrogation sur sa propre conversion.Charles Du Bos devoted an unflagging attention to Flaubert’s work (except for Bouvard et Pécuchet, which, apparently, according to him did not exist, to Madame Bovary and in particular L’Éducation sentimentale. The connection between his essay “Sur le milieu intérieur chez Flaubert”, written in 1921, and extracts from his Journal, from 1923 to 1937, the comparisons with Gogol, Thomas Hardy, Tolstoy, Baudelaire, and Henry James that run through the writings of Du Bos, allow us to follow what he terms “the spiritual experience” of a materiality encompassed in the conquest of the triple demand of the Beautiful, the Living, the Truth. Du Bos detects the power of Flaubert’s work in the “disproportion” of his style, and the power of absorption that forms the density of his prose, showing an

Structure and chemical durability of barium borosilicate glass–ceramics containing zirconolite and titanite crystalline phases

International Nuclear Information System (INIS)

Li, Huidong; Wu, Lang; Xu, Dong; Wang, Xin; Teng, Yuancheng; Li, Yuxiang

2015-01-01

In order to increase the solubility of actinides in the glass matrix, the effects of CaO, TiO 2 , and ZrSiO 4 addition (abbreviated as CTZ, in the mole ratio of 2:2:1) on crystalline phases, microstructure, and chemical durability of barium borosilicate glass–ceramics were investigated. The results show that the samples possess both zirconolite-2M and titanite phase when the CTZ content is greater than or equal to 45 wt.%. For the glass–ceramics with 45 wt.% CTZ (CTZ-45), only zirconolite-2M phase is observed after annealing at 680–740 °C for 2 h. The CTZ-45 possess zirconolite-2M and titanite phases after annealing at 700 °C first, and then annealing at 900–1050 °C for 2 h. Furthermore, the zirconolite-2M and titanite grains show a strip and brick shape, respectively. The CTZ-45 annealing at 950 °C shows the lower normalized leaching rates of B, Na and Nd when compared to that of CTZ-0 and CTZ-55. - Highlights: • CaO, TiO 2 , ZrSiO 4 (CTZ) as nucleating agents were added to barium borosilicate glass. • The samples with 45–55 wt% CTZ possess CaZrTi 2 O 7 -2M and CaTiSiO 5 crystalline phases. • CTZ-45 (45wt% CTZ) possesses only CaZrTi 2 O 7 -2M phase after annealing at 680–740 °C. • CTZ-45 possesses CaZrTi 2 O 7 -2M and CaTiSiO 5 phases after annealing at 900–1050 °C. • CTZ-45 annealing at 950 °C shows the lower leaching rates of B, Na and Nd than CTZ-0 and CTZ-55.

Droit du dommage corporel systèmes d'indemnisation

CERN Document Server

Lambert-Faivre, Yvonne

2015-01-01

Le Droit du dommage corporel est aujourd'hui une spécialité reconnue, à la convergence du droit civil et du droit pénal, du droit de la consommation et du droit de l'environnement, du droit de la sécurité sociale et du droit des transports, etc. La sécurité et l'intégrité de la personne humaine sont des droits fondamentaux où l'exigence éthique et l'équité confortent la règle juridique pour tenter d'indemniser les victimes de dommages corporels avec efficacité et transparence. Dans tous ces domaines, cette 8e édition rend compte de l'actualité du droit du dommage corporel : jurisprudence détaillée sur la nomenclature des préjudices réparables, à l'heure où sa consécration par décret reste en suspens, évaluation médicale et monétaire des préjudices, actualité jurisprudentielle du recours des tiers payeurs (article 25 de la loi du 21 décembre 2006 et ses difficultés d'application), sécurité sociale, responsabilité médicale et indemnisations des victimes d'accidents médica...

W. E. B. Du Bois: Reform, Will, and the Veil

Science.gov (United States)

England, Lynn; Warner, W. Keith

2013-01-01

While W. E. B. Du Bois is widely recognized for his contributions to the sociology of race, his contributions to the foundations of sociology are largely ignored. His sociology is based on African American reformism, a version of pragmatism, and a contingent historicism. The basic view of sociology is one that emphasizes the role of chance and…

De Paris à Lyon. Les mutations éditoriales du «Lancelot du Lac»

Directory of Open Access Journals (Sweden)

Gaëlle Burg

2015-07-01

Full Text Available Lancelot du Lac est le premier roman arthurien imprimé à la Renais­sance. Dans sa première édition parue en 1488, qui réunit deux imprimeurs (Jean Le Bourgeois à Rouen et Jean Du Pré à Paris, un découpage et un prologue inédits sont ajoutés par le remanieur. Le texte sera réédité six fois par divers imprimeurs-libraires parisiens jusqu’en 1533. L’édition de luxe d’Antoine Vérard (1494, destinée au roi Charles VIII, présente d’importantes modifications effectuées dans un but commercial. Après une longue période d’accalmie qui signe le début du déclin de la vogue des romans de chevalerie médiévaux, Benoît Rigaud publie à Lyon, sous une forme considérablement abrégée, la dernière édition connue du Lancelot au XVIe siècle (1591. Si elle ne présente que peu d’intérêt littéraire, elle apporte cependant des informations concernant les pratiques éditoriales et les goûts du  lecteur de la fin du XVIe siècle. De Paris à Lyon, entre renaissance et déclin, le parcours éditorial d’un incontournable roman arthurien.Lancelot du Lac is the editio princeps of an Arthurian romance in Renaissance France. The first edition in 1488, which brings together two printers (Jean Le Bourgeois from Rouen and Jean Du Pré from Paris, offers original arrangement and prologue added by the compositor. The text will be published six times by various printers and booksellers in Paris until 1533. The luxurious edition from Antoine Vérard (1494 dedicated to King Charles VIII provides interesting transformations in commercial purposes. After a long time without edition, showing the beginning of chivalry literature’s decline, Benoît Rigaud publish in Lyon, in a greatly abbreviated form, the last known edition of Lancelot in the XVIth century (1591. If it presents no literary interest, it provides nevertheless informations about editorial practices and reader’s tastes from the end of Renaissance France. From Paris to

Study of Structural Properties of Mesoporous Carbon From Fructose with Zinc Borosilicate Activator

Directory of Open Access Journals (Sweden)

Tutik Setianingsih

2014-04-01

Full Text Available Structural properties, including pore structure, functional group of carbon surface, and crystal structure of carbon built by zinc borosilicate (ZBS and ZnCl2 (Z have been investigated in this work. Physically, ZBS and ZnCl2 may act as template of carbon, whereas the Zn(II cation act as chemical activator of carbonization. All precursors of ZBS (silicagel, boric acid, and ZnCl2 may act as catalysts of caramelization. The caramelization was conducted hydrothermally at 85oC and thermally 130oC. The carbonization was conducted at 450oC. The resulted carbons were washed by using HF 48% solution, 1M HCl solution, and aquadest respectively. The solid products were characterized by using nitrogen gas adsorption, infrared spectrophotometry, X-ray diffraction, and Transmition Electron Microscopy. Result of research showed that ZBS built larger mesopore volume, larger pore domination of pore size, more hydrophobic carbon, and more amorf than ZnCl2.

Les premiers tours du monde à forfait. L’exemple de la Société des Voyages d’Etudes Autour du Monde (1878)

OpenAIRE

Gauthier, Lionel

2012-01-01

Dans la seconde moitié du XIXe siècle, avec le développement du bateau à vapeur et du chemin de fer, et l’ouverture de nouveaux axes de transport comme le Canal de Suez, le voyage autour du monde devient envisageable pour les touristes. Ainsi, dès 1872 des tours du monde à forfait sont organisés, ce qui témoigne de l’entrée du voyage autour du monde dans l’industrie touristique naissante. Cet article étudie ces premiers voyages d’un nouveau genre à travers l’exemple de la Société des Voyages ...

Leach behavior of high-level borosilicate glasses under deep geological environment

International Nuclear Information System (INIS)

Kim, Seung Soo; Chun, Kwan Sik; Park, Hyun Soo

1998-02-01

This report presents an overview of the activities in high-level radioactive waste glass which is considered as the most practicable form of waste, and also is intended to be used in the disposal of national high-level radioactive waste in future. Leach theory of waste glass and the leach effects of ground water, metal barrier, buffer materials and rocks on the waste glass were reviewed. The leach of waste glass was affected by various factors such as composition, pH and Eh of ground water, temperature, pressure, radiation and humic acid. The crystallization, crack, weathering and the formation of altered phases of waste glass which is expected to occur in real disposal site were reviewed. The results of leaching in laboratory and in-situ were compared. The behaviors of radioactive elements leached from waste glass and the use of basalt glass for the long-term natural analogue of waste glass were also written in this report. The appraisal of durability of borosilicate waste glass as a waste media was performed from the known results of leach test and international in-situ tests were introduced. (author). 134 refs., 15 tabs., 24 figs

Volatilization from borosilicate glass melts of simulated Savannah River Plant waste

International Nuclear Information System (INIS)

Wilds, G.W.

1979-01-01

Laboratory scale studies determined the rates at which the semivolatile components sodium, boron, lithium, cesium, and ruthenium volatilized from borosilicate glass melts that contained simulated Savannah River Plant waste sludge. Sodium and boric oxides volatilize as the thermally stable compound sodium metaborate, and accounted for approx. 90% of the semivolatiles that evolved. The amounts of semivolatiles that evolved increased linearly with the logarithm of the sodium content of the glass-forming mixture. Cesium volatility was slightly suppressed when titanium dioxide was added to the melt, but was unaffected when cesium was added to the melt as a cesium-loaded zeolite rather than as a cesium carbonate solution. Volatility of ruthenium was not suppressed when the glass melt was blanketed with a nonoxidizing atmosphere. Trace quantities of mercury were removed from vapor streams by adsorption onto a silver-exchanged zeolite. A bed containing silver in the ionic state removed more than 99.9% of the mercury and had a high chemisorption capacity. Beds of lead-, copper-, and copper sulfide-exchanged zeolite-X and also an unexchanged zeolite-X were tested. None of these latter beds had high removal efficiency and high chemisorption capacity

Volatilization from borosilicate glass melts of simulated Savannah River Plant waste

International Nuclear Information System (INIS)

Wilds, G.W.

1978-01-01

Laboratory scale studies determined the rates at which the semivolatile components sodium, boron, lithium, cesium, and ruthenium volatilized from borosilicate glass melts that contained simulated Savannah River Plant waste sludge. Sodium and boric oxides volatilize as the thermally stable compound sodium metaborate, and accounted for approx. 90% of the semivolatiles that evolved. The amounts of semivolatiles that evolved increased linearly with the logarithm of the sodium content of the glass-forming mixture. Cesium volatility was slightly suppressed when titanium dioxide was added to the melt, but was unaffected when cesium was added to the melt as a cesium-loaded zeolite rather than as a cesium carbonate solution. Volatility of ruthenium was not suppressed when the glass melt was blanketed with a nonoxidizing atmosphere. Trace quantities of mercury were removed from vapor streams by adsorption onto a silver-exchanged zeolite. A bed containing silver in the ionic state removed more than 99.9% of the mercury and had a high chemisorption capacity. Beds of lead-, copper-, and copper sulfide-exchanged zeolite-X and also an unexchanged zeolite-X were tested. None of these latter beds had high removal efficiency and high chemisorption capacity

Characteristics of borosilicate waste glass form for high-level radioactive waste

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Soo; Chun, Kwan Sik; Choi, Jong Won; Kang, Chul Hyung

2001-03-01

Basic data, required for the design and the performance assessment of a repository of HLW, suchas the chemical composition and the characteristics of the borosilicate waste glass have been identified according to the burn-ups of spent PWR fuels. The diemnsion of waste canister is 430mm in diameter and 1135mm in length, and the canister should hold less than 2kwatts of heat from their decay of radionuclides contained in the HLW. Based on the reprocessing of 5 years-cooled spent fuel, one canister could hold about 11.5wt.% and 10.8wt.% of oxidized HLW corresponding to their burn-ups of 45,000MWD/MTU and 55,000MWD/MTU, respectively. These waste forms have been recommanded as the reference waste forms of HLW. The characteristics of these wastes as a function of decay time been evaluated. However, after a specific waste form and a specific site for the disposal would be selected, the characteristics of the waste should be reevaluated under the consideration of solidification period, loaded waste, storage condition and duration, site circumstances for the repository system and its performance assessment.

Les dispositifs du Net art

OpenAIRE

Fourmentraux, Jean-Paul

2010-01-01

La pratique du Net art radicalise la question du potentiel communicationnel d’un média —Internet— qui constitue tout à la fois le support technique, l’outil créatif et le dispositif social de l’œuvre. Les technologies de l’information et de la communication (TIC) placent en effet l’œuvre d’art au cœur d’une négociation socialement distribuée entre l’artiste et le public. L’article est focalisé sur cette construction collective du Net art et sur ses mises en scènes. Il montre le travail artist...

Bassins versants du Loup, de la Cagne et du Malvan

OpenAIRE

Lepère, Cédric; Lautier, Laurence; Pellegrino, Emmanuel

2013-01-01

Identifiant de l'opération archéologique : 8453 Date de l'opération : 2007 (PC) ; 2007 (PI) Inventeur(s) : Lepère Cédric (AUT) ; Lautier Laurence (AUT) ; Pellegrino Emmanuel (AUT) Une campagne de prospection inventaire a été effectuée pendant trois mois, dans les bassins-versants de la Cagne, du Loup et du Malvan qui regroupent les communes de Cagnes-sur-Mer, Villeneuve-Loubet, La Colle-sur-Loup, Saint-Paul-de-Vence, Vence, Saint-Jeannet, Bezaudun, Tourrettes-sur-Loup, Roquefort-les-Pins, Le ...

Visite du Conseil des gouverneurs du CRDI en Afrique de l'Est ...

International Development Research Centre (IDRC) Digital Library (Canada)

17 oct. 2017 ... La délégation dans la communauté La délégation à l'école féminine. La délégation avec les membres du Women's Group. Durant la visite, Jean Lebel et Molapo Qhobela, directeur général de la Fondation nationale de la recherche de l'Afrique du Sud, ont annoncé les projets retenus au Kenya et en ...

Influence of processing conditions on the glass-crystal transition into borosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Deschanels, X.; Cachia, J.N.; Lopez, C.; Peuget, S. [CEA Marcoule, BP 17171, 30207 Bagnols sur Ceze (France)

2008-07-01

The precipitation of a crystalline phase in glass is observed when one element exceeds its loading limit (i.e.: solubility limit). In this work we have studied the solubility of different actinides and surrogates (lanthanides and hafnium) in borosilicate glass used for the immobilization of the high-level nuclear waste (HLW glasses). The results obtained show an increase of the solubility limits of these elements with the processing temperature and the redox potential of the melt. The elements at the oxidation state (III) exhibit a higher solubility than the element at oxidation state (IV). In this framework, cerium is an interesting element because its oxidation state tunes from (IV) to (III) as a function of the processing conditions. It is shown that the solubility of cerium can be multiplied by a factor of 20 at 1100 C. degrees. In order to have a better understanding of the mechanisms that underline the evolution of the solubility, XAFS and NMR investigation has been undertaken. Trivalent elements present the characteristics of network-modified cations while tetravalent elements look like network-former cations.

High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 2

International Nuclear Information System (INIS)

Cunnane, J.C.

1994-03-01

The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion.This document is organized into three volumes. Volumes I and II represent a tiered set of information intended for somewhat different audiences. Volume I is intended to provide an overview of waste glass corrosion, and Volume 11 is intended to provide additional experimental details on experimental factors that influence waste glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II. Volume I is intended for managers, decision makers, and modelers, the combined set of Volumes I, II, and III is intended for scientists and engineers working in the field of high-level waste

High-level waste borosilicate glass: A compendium of corrosion characteristics. Volume 2

Energy Technology Data Exchange (ETDEWEB)

Cunnane, J.C. [comp.; Bates, J.K.; Bradley, C.R. [Argonne National Lab., IL (United States)] [and others

1994-03-01

The objective of this document is to summarize scientific information pertinent to evaluating the extent to which high-level waste borosilicate glass corrosion and the associated radionuclide release processes are understood for the range of environmental conditions to which waste glass may be exposed in service. Alteration processes occurring within the bulk of the glass (e.g., devitrification and radiation-induced changes) are discussed insofar as they affect glass corrosion.This document is organized into three volumes. Volumes I and II represent a tiered set of information intended for somewhat different audiences. Volume I is intended to provide an overview of waste glass corrosion, and Volume 11 is intended to provide additional experimental details on experimental factors that influence waste glass corrosion. Volume III contains a bibliography of glass corrosion studies, including studies that are not cited in Volumes I and II. Volume I is intended for managers, decision makers, and modelers, the combined set of Volumes I, II, and III is intended for scientists and engineers working in the field of high-level waste.

La L.O.L.F. et les projets annuels de performance (P.A.P.) : Elaboration des figures du citoyen, de l'usager, du contribuable et du service public

OpenAIRE

Eyraud, Corine

2006-01-01

Nous nous intéresserons ici à la fois aux questions de la mesure des effets de l'action publique - ici l'action publique éducative universitaire -, aux dispositifs qui « construisent » les figures de l'usager (en tant que client ?), du citoyen, du contribuable et du service public, et aux nouvelles formes de démocratie que ces dispositifs génèrent (ou pas).

Deep-UV Raman spectroscopic analysis of structure and dissolution rates of silica-rich sodium borosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Pierce, Eric M [ORNL; WindischJr., Charles F. [Pacific Northwest National Laboratory (PNNL); Burton, Sarah D. [Pacific Northwest National Laboratory (PNNL); Bovaird, Chase C. [Pacific Northwest National Laboratory (PNNL)

2010-01-01

As part of ongoing studies to evaluate relationships between structure and rates of dissolution of silicate glasses in aqueous media, sodium borosilicate glasses of composition Na2O xB2O3 (3 x)SiO2, with x 1 (Na2O/B2O3 ratio 1), were analyzed using deep-UV Raman spectroscopy. Results were quantified in terms of the fraction of SiO4 tetrahedra with one non-bridging oxygen (Q3) and then correlated with Na2O and B2O3 content. The Q3 fractionwas found to increase with increasing Na2O content, in agreement with studies on related glasses, and, as long as the value of x was not too high, this contributed to higher rates of dissolution in single pass flow-through testing. In contrast, dissolution rates were less strongly determined by the Q3 fraction when the value of x was near unity, and appeared to grow larger upon further reduction of the Q3 fraction. Results were interpreted to indicate the increasingly important role of network hydrolysis in the glass dissolution mechanism as the BO4 tetrahedron replaces the Q3 unit as the charge-compensating structure for Na+ ions. Finally, the use of deep-UV Raman spectroscopy was found to be advantageous in studying finely powdered glasses in cases where visible Raman spectroscopy suffered from weak Raman scattering and fluorescence interference.

25 years of the Conseil du Léman

CERN Multimedia

2012-01-01

On 30 June, the Conseil du Léman will celebrate its 25th anniversary. The Conseil, which comprises representatives of the French departments of Ain and Haute-Savoie and the Swiss cantons of Geneva, Vaud and Valais, was set up to promote cross-border cooperation in the Lake Geneva region.   To celebrate its quarter centenary, the Conseil will be holding a day of discussions and activities, including a round-table discussion in CERN’s Globe of Science and Innovation. You are cordially invited to participate in the round-table discussion, which will be led by prominent representatives of each of the Conseil’s five constituent authorities: Round-Table Discussion The Challenges of Cross-border Cooperation: A look back at the role of the Conseil du Léman over the past 25 years. Saturday, 30 June 9.30 am - 12.30 pm Globe of Science and Innovation During the afternoon, activities for the general public will be organised in the park of the Château de ...

COMMUNICATION DU CREDIT AGRICOLE - French version only

CERN Multimedia

2003-01-01

La Direction du Crédit Agricole informe son aimable clientèle du CERN des jours et heures d'ouverture de l'agence du site de Prévessin à compter du mardi 14 janvier 2003 : 1. Horaires pour les opérations bancaires courantes 7 jours sur 7 et 24h/24 avec l'espace libre service bancaire. 2. Horaires conseil du mardi au vendredi - Mardi, de 9h. à 12h. et de 14h.15 à 16h.30. - Mercredi, jeudi et vendredi, de 9h. à 12h. et de 13h.30 à 16h.30. Deux collaboratrices au lieu d'une seront désormais présentes toute la journée du mardi au vendredi pour vous accueillir, vous informer et vous conseiller en crédits et placements (réception conseil sur rendez-vous). Autre nouveauté : les mêmes conseillers seront aussi à votre disposition le samedi, sur notre agence de Gex, de 8h.15 à 13h.05, notamment pour les études de financements habitat. La Direction et toute l'équipe de l'agence du Crédit Agricole vous souhaitent une excellent année 2003.

Paul Celan in Translation: "Du sei wie du"

Directory of Open Access Journals (Sweden)

John Felstiner

1983-09-01

Full Text Available Translating the lyric poetry of Paul Celan, especially his later poems, carries not only the endemic challenge and difficulty of any verse translation, but the added incentive of doing justice to a writer whose whole recourse after the Holocaust—whose sanctuary, if he was to have any at all—he sought in language itself, specifically in the Muttersprache , the mother tongue that was as well the tongue of those who murdered his mother and father. This essay exposes a process of translating "Du sei wie du" (1970, which perhaps more than any other poem by Celan, at once solicits and defies translation, moving as it does from modern to medieval German, and closing with Hebrew words from Isaiah— a messianic imperative that shows Celan verging as ever on his Jewish identity.

Gestion intégrée du mildiou du mil en station au centre régional de ...

African Journals Online (AJOL)

user

Le mil (Pennicetum glaucum) L.R.Br constitue 75% de la production céréalière du Niger. Cependant, son rendement est très faible dû à plusieurs types de contraintes. La maladie du mildiou du mil causé par un champignon Sclerospora graminicola (Sacc) Schroët, occupe une place importante. L'objectif de cette étude.

Festival du rire de Genève

CERN Document Server

Staff Association

2015-01-01

Connaissez-vous le Festival du rire de Genève ? La deuxième édition aura lieu du 25 au 28 mars 2015 au Casino-Théâtre à Carouge. Côté programmation, Marc Donnet-Monay ouvre les festivités avant trois autres soirées de folie et d’humour que nous vous laissons le soin de découvrir dans le programme : http://www.rire-geneve.ch/#programme. Réduction de 30% sur l’achat de places pour les membres du personnel du CERN. Pour cela, il suffit de se rendre sur la billetterie en ligne de notre site : www.rire-geneve.ch et d’utiliser le code promotionnel. Contacter le secrétariat de l’Association du personnel (Staff.Association@cern.ch) pour connaitre ce code promotionnel.

Reinforcement of poly-l-lactic acid electrospun membranes with strontium borosilicate bioactive glasses for bone tissue engineering.

Science.gov (United States)

Fernandes, João S; Gentile, Piergiorgio; Martins, Margarida; Neves, Nuno M; Miller, Cheryl; Crawford, Aileen; Pires, Ricardo A; Hatton, Paul; Reis, Rui L

2016-10-15

Herein, for the first time, we combined poly-l-lactic acid (PLLA) with a strontium borosilicate bioactive glass (BBG-Sr) using electrospinning to fabricate a composite bioactive PLLA membrane loaded with 10% (w/w) of BBG-Sr glass particles (PLLA-BBG-Sr). The composites were characterised by scanning electron microscopy (SEM) and microcomputer tomography (μ-CT), and the results showed that we successfully fabricated smooth and uniform fibres (1-3μm in width) with a homogeneous distribution of BBG-Sr microparticles (bone marrow-derived mesenchymal stem cells (BM-MSCs) demonstrated that PLLA-BBG-Sr membranes promoted the osteogenic differentiation of the cells as demonstrated by increased alkaline phosphatase activity and up-regulated osteogenic gene expression (Alpl, Sp7 and Bglap) in relation to PLLA alone. These results strongly suggest that the composite PLLA membranes reinforced with the BBG-Sr glass particles have potential as an effective biomaterial capable of promoting bone regeneration. PLLA membranes were reinforced with 10% (w/w) of strontium-bioactive borosilicate glass microparticles, and their capacity to induce the osteogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) was evaluated. These membranes presented an increased: degradability, water uptake, Young modulus and tensile strength. We also demonstrated that these membranes are non-cytotoxic and promote the attachment of BM-MSCs. The addition of the glass microparticles into the PLLA membranes promoted the increase of ALP activity (under osteogenic conditions), as well as the BM-MSCs osteogenic differentiation as shown by the upregulation of Alpl, Sp7 and Bglap gene expression. Overall, we demonstrated that the reinforcement of PLLA with glass microparticles results in a biomaterial with the appropriate properties for the regeneration of bone tissue. Copyright © 2016 Acta Materialia Inc. All rights reserved.

Preparation and nonlinear optical properties of indium nanocrystals in sodium borosilicate glass by the sol–gel route

International Nuclear Information System (INIS)

Zhong, Jiasong; Xiang, Weidong; Zhao, Haijun; Chen, Zhaoping; Liang, Xiaojuan; Zhao, Wenguang; Chen, Guoxin

2012-01-01

Graphical abstract: The sodium borosilicate glass doped with indium nanocrystals have been successfully prepared by sol–gel methods. And the indium nanocrystals in tetragonal crystal system have formed uniformly in the glass, and the average diameter of indium nanocrystals is about 30 nm. The third-order optical nonlinear refractive index γ, absorption coefficient β, and susceptibility χ (3) of the glass are determined to be −4.77 × 10 −16 m 2 /W, 2.67 × 10 −9 m/W, and 2.81 × 10 −10 esu, respectively. Highlights: ► Indium nanocrystals embedded in glass matrix have been prepared by sol–gel route. ► The crystal structure and composition are investigated by XRD and XPS. ► Size and distribution of indium nanocrystals is determined by TEM. ► The third-order optical nonlinearity is investigated by using Z-scan technique. -- Abstract: The sodium borosilicate glass doped with indium nanocrystals have been successfully prepared by sol–gel route. The thermal stability behavior of the stiff gel is investigated by thermogravimetric (TG) and differential thermal (DTA) analysis. The crystal structure of the glass is characterized by X-ray powder diffraction (XRD). Particle composition is determined by X-ray photoelectron spectroscopy (XPS). Size and distribution of the nanocrystals are characterized by transmission electron microscopy (TEM) as well as high-resolution transmission electron microscopy (HRTEM). Results show that the indium nanocrystals in tetragonal crystal structure have formed in glass, and the average diameter is about 30 nm. Further, the glass is measured by Z-scan technique to investigate the nonlinear optical (NLO) properties. The third-order NLO coefficient χ (3) of the glass is determined to be 2.81 × 10 −10 esu. The glass with large third-order NLO coefficient is promising materials for applications in optical devices.

Alpha radiation and in-pile annealing effects on the fracture properties of a sintered alumino borosilicate glass

International Nuclear Information System (INIS)

Bevilacqua, Arturo M.; Prado, Miguel O.; Messi de Bernasconi, Norma B.; Heredia, Arturo D.; Sanfilippo, Miguel

1999-01-01

The alpha radiation and the in-pile during irradiation effects on the hardness, the crack nucleation and the fracture toughness of the German alumino borosilicate glass SG7 were investigated by using the Vickers indentation. Cold pressed and sintered samples were irradiated with thermal neutrons, in the Argentine nuclear reactors RA-3 and RA-6, to produce alpha particles in the whole volume of the glass by means of the (n, alpha)-reaction with B-10. The Vickers hardness, the crack nucleation, as 50 percent fracture probability load, plotted as the Weibull's fracture probability distribution function and the fracture toughness, as critical stress intensity factor K Ic , were correlated to the four cumulative disintegration values. It was ascertained that: a) the Vickers hardness decreases from 5.6 GPa for the non-irradiated sample up to 4.7 GPa for the sample irradiated 70 h at the lower neutron flux (4.0 x 10 - sup 18 - alpha disintegration per cm - sup 3 -), b) the 50 % fracture probability load increases from 1.4 N for the non-irradiated sample up to 4.7 g for the sample irradiated 22 h at the higher flux (6.8 x 10 - sup 18 - alpha disintegration per cm - sup 3 -), and c) the stress intensity factor increases from 0.80 MPa.m - sup 1/2 - for the non irradiated sample up to 0.86 MPa.m - sup 1/2 - for the sample mentioned in b). The in-pile annealing was analyzed by comparing the crack nucleation after irradiation with data obtained by heavy ion irradiation followed by thermal annealing. Results for the SG7 glass were compared to those for soda-lime and borosilicate glasses. (author)

Use of potassium-42 in the study of kidney functioning; Emploi du patassium-12 pour l'etude du fonctionnement renal

Energy Technology Data Exchange (ETDEWEB)

Morel, F; Guinnebault, M [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

Following an intravenous injection of potassium-42 as indicator, an analysis of the specific activity vs. time curve in arterial plasma, in venous plasma efferent from the kidney, in urine and in various regions of the kidney of rabbits reveals that: 1) The turnover rate of potassium in the cortex cells (proximal and distal convoluted tubes) is very large, being limited only by renal blood flow. 2) The turnover rate of potassium in deep regions (Henle loops and collector tubules) is much smaller. 3) Potassium in the urine comes from cells of the convoluted tubes and not from cells of Henle loops, collector ducts, or glomerular filtrate. 4) Any potassium filtered at the level of the glomerules would be entirely reabsorbed at the level of the proximal tube, while total potassium in the urine results from a process of excretion by cells of the distal tube. These results are comparable with the assumption that the movement of potassium between interstitial medium and convoluted tube cells results from entirely passive processes. (author) [French] Apres injection intraveineuse au lapin de radiopotassium comme indicateur, l'analyse des courbes de la radioactivite specifique du potassium, mesuree en fonction du temps dans le plasma arteriel, dans le plasma veineux efferent du rein, dans l'urine et dans diverses regions du rein, lui-meme, permet de montrer: 1)que la vitesse de renouvellement du potassium contenu dans les cellules du cortex (tubes contournes proximaux et distaux), apparait tres grande et semble limitee par le debit sanguin renal. 2) que le vitesse de renouvellement du potassium contenu dans les regions profondes (anses de Henle et tubes collecteurs) est beaucoup plus faible. 3) que le potassium de l'urine a pour precurseur le potassium des cellules des tubes contournes et non celui des cellules des anses de Henle ou des canaux collecteurs, ni celui du filtrat glomerulaire. 4) que le potassium filtre au niveau des glomerules serait entierement reabsorbe au

Investigating the effect of V{sub 2}O{sub 5} addition on sodium barium borosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Halder, Rumu, E-mail: rumuhalder24feb@gmail.com; Sengupta, Pranesh; Dey, G. K. [Materials Science Division, Bhabha Atomic Research Centre, Mumbai-700 085 (India); Sudarsan, V. [Chemistry Division, Bhabha Atomic Research Centre, Mumbai-700 085 (India); Kaushik, C. P. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai-700 085 (India)

2016-05-23

V{sub 2}O{sub 5} doped sodium barium borosilicate glasses were characterized by photoluminescence spectroscopy and electron probe microanalyzer (EPMA). The glass remains homogeneous for lower concentration of V{sub 2}O{sub 5} but a phase separation is observed when V{sub 2}O{sub 5} doping is increased beyond 5 mol%. Detailed microanalysis reveals that the phase separated glass consists of a phase containing V, Ba and Si and a separate Si rich phase within the glass matrix. The luminescence study demonstrated that at low concentration the vanadium mainly interacts with the structural units of B/Si while at higher concentrations, V-O-V/ V-O{sup −} Na{sup +}/Ba{sup 2+} linkages are formed.

Color-converted remote phosphor prototype of a multiwavelength excitable borosilicate glass for white light-emitting diodes

International Nuclear Information System (INIS)

Tian Hua; Qiu Kun; Song Jun; Wang Da-Jian; Liu Ji-Wen

2012-01-01

We report a unique red light-emitting Eu-doped borosilicate glass to convert color for warm white light-emitting diodes. This glass can be excited from 394 nm-peaked near ultraviolet light, 466 nm-peaked blue light, to 534 nm-peaked green light to emit the desired red light with an excellent transmission in the wavelength range of 400–700 nm which makes this glass suitable for color conversion without a great cost of luminous power loss. In particular, when assembling this glass for commercial white light-emitting diodes, the tested results show that the color rendering index is improved to 84 with a loss of luminous power by 12 percent at average, making this variety of glass promising for inorganic “remote-phosphor” color conversion

Bulletin du CRDI #127

International Development Research Centre (IDRC) Digital Library (Canada)

La mise à l'échelle de la recherche et de l'innovation en vue de créer un impact social constitue une priorité pour la communauté du développement. Toutefois ... Nous avons renouvelé notre soutien à la recherche auprès du gouvernement de l'Inde ... Des femmes étudient à l'École supérieure d'infotronique d'Haïti.

Performances comparées du HDL-cholestérol et du ratio cholestérol ...

African Journals Online (AJOL)

Pour le dépistage du SMet, l'AUC du CT/HDL-C est de 0,69 (IC 95% 0,61-0,77) chez les ... high blood pressure (BP), high fasting glucose, low HDL-C and high triglycerides. Areas under the "Receiver operator characteristic" curves (AUC)

La reconstruction du sourcil par greffon composite du cuir chevelu: une astuce pour faciliter la technique

Science.gov (United States)

El Omari, Mounia; El Mazouz, Samir; Gharib, Noureddine; EL Abbassi, Abdallah

2015-01-01

Les sourcils jouent un rôle important dans l’équilibre esthétique du visage. Leur reconstruction ou ophriopoïése, après séquelle de brûlure fait partie intégrante du programme de réhabilitation de la face brûlée. Plusieurs techniques ont été décrites. Nous insistons ici sur l'intérêt d'une technique simple, à la portée de tous les chirurgiens, et dont la méthode et les résultats peuvent être améliorés par un dessin bien planifié des zones donneuse et receveuse: la greffe composite prélevée au niveau du cuir chevelu dessinée à l'aide d'un calque du sourcil controlatéral. PMID:26401195

La disparition du temps en gravitation quantique

OpenAIRE

Saint-Ours, Alexis de

2012-01-01

Le but de ce travail est d’examiner l’incidence philosophique de la gravitation quantique sur le concept de temps. Je cherche à montrer qu’elle conduit à une disparition du temps comme dimension et ouvre la voie à une compréhension du temps comme variation et même à l’idée de variation pure. En l’absence de temps mécanique, il est cependant possible de définir un temps d’origine thermodynamique. Je montre en quoi cette dissociation du temps mécanique et du temps thermodynamique, fait écho à l...

Monnaie du commun et revenu social garanti

OpenAIRE

Baronian, Laurent; Vercellone, Carlo

2015-01-01

Le but de cet article est de poser les bases d’une approche de la monnaie du commun à partir d’une interrogation évincée par la théorie économique des biens communs. Notre analyse de la relation entre monnaie et théorie du commun s’articulera en trois parties. Dans la première, il s’agit d’établir une conception dynamique du commun au singulier dans laquelle la question de la monnaie et des mutations de la division du travail occupe une place centrale. Cette démarche fondée sur la triade trav...

Une mesure différente du bien-être : l'indice du bonheur national ...

International Development Research Centre (IDRC) Digital Library (Canada)

À la lumière de ces données, le Centre for Bhutan Studies publiera, en 2011, un indice du BNB quantitatif. Cette subvention permettra à l'OPHI d'assister le Centre dans la synthèse et l'analyse des résultats de l'enquête de 2010. L'objectif : assurer la validité et la reconnaissance internationale de l'indice du BNB de sorte ...

La femme du ménage The "perfect wife". The bride's role in wedding organization: setting the stage for unequal task sharing in marriage

Directory of Open Access Journals (Sweden)

Florence Maillochon

2009-09-01

Full Text Available Ce texte étudie la division sexuelle du travail dans l’organisation de la cérémonie de mariage. Les temporalités des hommes et des femmes divergent progressivement au cours des différentes étapes de la préparation du mariage (de l’élaboration du projet jusqu’au jour J en passant par l’organisation de la fête. Les femmes consacrent toujours plus de temps au collectif que les hommes. La cérémonie de mariage ne constitue donc pas seulement une étape de formation du couple mais aussi un point d’ancrage et d’incorporation du « partage inégal » du travail domestique au sein du couple. Au cours d’une série d’épreuves symboliques et techniques qu’elles traversent pour se métamorphoser en mariée et en épouse, les femmes apprennent progressivement à devenir la femme du ménage.This article studies the sexual division of labour when organizing the wedding ceremony. Men’s and women’s temporalities gradually diverge through the various steps of wedding preparation (from elaboration of the project up to the "big day" itself. Women spend more time than men on collective tasks.  The wedding ceremony is not only a key moment in founding the couple, but also a step towards instituting and embedding the “unequal sharing” of domestic work within the couple. The different symbolic and technical tests women go through to metamorphose into a spouse and bride make them learn how to become the "perfect wife".

Evolution du pH et de la température au cours de la transformation artisanale du cymbium (voluté). Essai sur les perspectives de valorisation du produit transformé

OpenAIRE

Diouf, A.

2008-01-01

L’étude porte sur l’évolution du pH et de la température au cours de la transformation artisanale du Cymbium, ainsi que sur les perspectives de valorisation du produit transformé. Les expérimentations menées au site de transformation artisanale de Joal ont permis de constater que : Après 12 heures de séjour en bac (1ère nuit), le Cymbium est encore en phase de rigor mortis. Le pH moyen affiché à l’issue de cette première nuit est de 7,6 ; donc proche de celui du mollusque ...

Nouvelles du Centre Aéré de l’Association du Personnel du CERN

CERN Multimedia

Jardin d'enfants

2015-01-01

Cet été 2015, durant quatre semaines d’été, le Centre Aéré a accueilli plus de 40 enfants âgés de 4 à 6 ans. Devant le succès rencontré, et à la demande des parents, il a été décidé d’en doubler la capacité maximale. A l'été 2016, du 4 au 29 juillet, la structure pourra accueillir les enfants de 4 ans révolus et de moins de 7 ans (nés après le 31/07/2009 mais avant  01/07/2012). Les inscriptions se feront à la semaine durant le mois d'Avril 2016. Les programmes sont en cours d'élaboration cependant nous pouvons déjà vous communiquer le thème conducteur du centre qui sera : à la découverte d'un continent différent chaque ...

Accroissement de la compétitivité du Kenya dans l'économie du ...

International Development Research Centre (IDRC) Digital Library (Canada)

La promulgation par le Kenya du Science, Technology and Innovation Bill, 2012 confirme l'intérêt et la volonté du gouvernement de mettre en oeuvre désormais un programme de développement fondé sur la science. La loi offre aussi au CRDI l'occasion d'appuyer le programme de recherche et de politiques de la nouvelle ...

Contributions of vitreous natural analogs to the investigation of long-term nuclear glass behavior; Apports des analogues naturels vitreux a la validation des codes de prediction du comportement a long terme des verres nucleaires

Energy Technology Data Exchange (ETDEWEB)

Techer, I

1999-07-01

This study assesses the extend of the analogy between the alteration behavior in water and in a moist clay environment of aluminosilicate volcanic glass and alumino-borosilicate nuclear containment glass. Basaltic glass alteration in water initially occurs by hydrolysis processes with an activation energy on the order of 73 kJ.mol{sup -1}. As the reaction progresses, the alteration rate drops by over four orders of magnitude from the initial rate r{sub 0}, The alteration kinetics are not governed by the alteration solution chemistry alone, the glass alteration film appears to have a major role as a diffusion barrier limiting the transfer of reaction species and products. All these aspects highlight the behavioral analogy between basaltic glass and nuclear borosilicate glass in aqueous media. Conversely, the alteration reaction of obsidian-type volcanic glass involves other mechanisms than those governing the dissolution of borosilicate glass. Basaltic glass alteration is also examined in the presence of a clay environmental material, in a study of the natural basaltic glass and argillaceous pelites system of the Salagou basin in southern France, in an approach combining mineralogical, chemical and isotopic data to assess the interactions between a basaltic glass and the argillaceous pelites. Laboratory leach test results with basaltic glass and measured data for the Salagou glass in its natural environment are modeled using a code implementing a kinetic law coupling diffusive transfer of dissolved silica with a reaction affinity law. (author)

L'aventure du grand collisionneur LHC du big bang au boson de Higgs

CERN Document Server

Denegri, Daniel; Hoecker, Andreas; Roos, Lydia; Rubbia, Carlo

2014-01-01

Qu'est-ce que la physique des particules élémentaires, le LHC, et le boson de Higgs ? Ce livre présente de manière simple le monde des quarks, des leptons et de leurs interactions, gouvernées par des symétries fondamentales de la nature, ainsi que le lien entre ce monde de l'infiniment petit et celui de l'infiniment grand. Cette conjonction entre la physique des particules élémentaires et l'évolution de la matière dans les premiers instants de l Univers qui ont suivi le Big-Bang est un des plus beaux acquis de la science de ces cinquante dernières années. Après une description du cadre théorique, le modèle standard, et de son élaboration durant la deuxième moitié du XXe siècle, l'accent est mis sur ses grands succès expérimentaux, mais aussi sur ses faiblesses ou insuffisances telles que nous les percevons aujourd'hui. La passionnante histoire du grand collisionneur de hadrons du CERN, le LHC, le plus grand projet purement scientifique jamais réalisé, est présentée à la fois sous ses...

Une brève histoire du temps du Big Bang aux trous noirs

CERN Document Server

Hawking, Stephen

2017-01-01

Stephen Hawking est universellement reconnu comme l'un des plus grands cosmologistes de notre époque et l'un des plus brillants physiciens depuis Einstein. Successeur de Newton, il occupe à l'université de Cambridge la chaire de Mathématiques, et s'est rendu célèbre pour ses travaux sur les origines de l'Univers. Une brève histoire du temps est le premier livre qu'il ait décidé d'écrire pour le non-spécialiste. Il y expose, dans un langage simple et accessible, les plus récents développements de l'astrophysique concernant la nature du temps et du monde. Retraçant les grandes théories du cosmos, de Galilée et Newton à Einstein et Poincaré, racontant les ultimes découvertes de l'espace, expliquant la nature des trous noirs, il propose ensuite de relever le plus grand défi de la science moderne : la recherche d'une théorie unitaire combinant et unifiant la relativité générale et la mécanique quantique. On sait que Stephen Hawking lutte depuis plus de trente ans contre une maladie neurolo...

Determination of the free enthalpies of formation of borosilicate glasses

International Nuclear Information System (INIS)

Linard, Y.

2000-01-01

This work contributes to the study of the thermochemical properties of nuclear waste glasses. Results are used to discuss mechanisms and parameters integrated in alteration models of conditioning materials. Glass is a disordered material defined thermodynamically as a non-equilibrium state. Taking into account one order parameter to characterise its configurational state, the metastable equilibrium for the glass was considered and the main thermochemical properties were determined. Calorimetric techniques were used to measure heat capacities and formation enthalpies of borosilicate glasses (from 3 to 8 constitutive oxides). Formation Entropies were measured too, using the entropy theory of relaxation processes proposed by Adam and Gibbs (1965). The configurational entropy contribution were determined from viscosity measurements. This set of data has allowed the calculation of Gibb's free energies of dissolution of glasses in pure water. By comparison with leaching experiments, it has been demonstrated that the decreasing of the dissolution rate at high reaction progress cannot be associated to the approach of an equilibrium between the sound glass and the aqueous solution. The composition changes of the reaction area at the glass surface need to be considered too. To achieve a complete description of the thermodynamic stability, the equilibrium between hydrated de-alkalinized glass and/or the gel layer with the aqueous solution should also be evaluated. (author)

Behaviour of ruthenium dioxide particles in borosilicate glasses and melts

Energy Technology Data Exchange (ETDEWEB)

Pflieger, Rachel [DEN/DTCD-SCDV/CEA Valrho, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze (France); Institut de Chimie Separative de Marcoule, UMR5257, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze Cedex (France)], E-mail: rachel_pflieger@yahoo.fr; Lefebvre, Leila [DEN/DTCD-SCDV/CEA Valrho, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze (France); Malki, Mohammed [CNRS/CEMHTI-1D Av. de la Recherche Scientifique, 45701 Orleans cedex 2 (France); Polytech Orleans, Universite d' Orleans, 8 rue Leonard de Vinci, 45072 Orleans cedex 2 (France); Allix, Mathieu [CNRS/CEMHTI-1D Av. de la Recherche Scientifique, 45701 Orleans cedex 2 (France); Grandjean, Agnes [DEN/DTCD-SCDV/CEA Valrho, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze (France); Institut de Chimie Separative de Marcoule, UMR5257, Centre de Marcoule, BP17171, 30207 Bagnols-sur-Ceze Cedex (France)

2009-06-01

Ruthenium-glass systems are formed during the vitrification of nuclear waste. They are also widely used in micro-electronics because of their unique electrical properties. However, the interaction of this element with the glass matrix remains poorly understood. This work focuses on a RuO{sub 2} particles-nuclear alumino-borosilicate glass system in which the electrical conductivity is known to vary considerably with the RuO{sub 2} content and to become electronic above about 0.5-0.7 vol.% RuO{sub 2} [R. Pflieger, M. Malki, Y. Guari, J. Larionova, A. Grandjean, J. Am. Ceram. Soc., accepted for publication]. Some RuO{sub 2} segregation was observed in SEM/TEM investigations but no continuous chain of RuO{sub 2} particles could be seen. Electron relays between the particles are then necessary for a low-rate percolation, such as the nanoclusters suggested by Adachi et al. [K. Adachi, S. Iida, K. Hayashi, J. Mater. Res. 9 (7) (1994) 1866; K. Adachi, H. Kuno, J. Am. Ceram. Soc. 83 (10) (2000) 2441], which could consist in dissolved ruthenium. Indeed, several observations made here clearly indicate the presence of dissolved ruthenium in the glass matrix, like the modification of the glass density in presence of RuO{sub 2} particles or the diffusion-limited growth of RuO{sub 2} particles in the melt.

Use of potassium-42 in the study of kidney functioning; Emploi du patassium-12 pour l'etude du fonctionnement renal

Energy Technology Data Exchange (ETDEWEB)

Morel, F.; Guinnebault, M. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

Following an intravenous injection of potassium-42 as indicator, an analysis of the specific activity vs. time curve in arterial plasma, in venous plasma efferent from the kidney, in urine and in various regions of the kidney of rabbits reveals that: 1) The turnover rate of potassium in the cortex cells (proximal and distal convoluted tubes) is very large, being limited only by renal blood flow. 2) The turnover rate of potassium in deep regions (Henle loops and collector tubules) is much smaller. 3) Potassium in the urine comes from cells of the convoluted tubes and not from cells of Henle loops, collector ducts, or glomerular filtrate. 4) Any potassium filtered at the level of the glomerules would be entirely reabsorbed at the level of the proximal tube, while total potassium in the urine results from a process of excretion by cells of the distal tube. These results are comparable with the assumption that the movement of potassium between interstitial medium and convoluted tube cells results from entirely passive processes. (author) [French] Apres injection intraveineuse au lapin de radiopotassium comme indicateur, l'analyse des courbes de la radioactivite specifique du potassium, mesuree en fonction du temps dans le plasma arteriel, dans le plasma veineux efferent du rein, dans l'urine et dans diverses regions du rein, lui-meme, permet de montrer: 1)que la vitesse de renouvellement du potassium contenu dans les cellules du cortex (tubes contournes proximaux et distaux), apparait tres grande et semble limitee par le debit sanguin renal. 2) que le vitesse de renouvellement du potassium contenu dans les regions profondes (anses de Henle et tubes collecteurs) est beaucoup plus faible. 3) que le potassium de l'urine a pour precurseur le potassium des cellules des tubes contournes et non celui des cellules des anses de Henle ou des canaux collecteurs, ni celui du filtrat glomerulaire. 4) que le potassium filtre au niveau des glomerules serait entierement

W. E. B. Du Bois: A Dynamic Communicator and Cultural Iconoclast.

Science.gov (United States)

Reppert, James E.

This paper presents a biographical sketch of the prolific African-American writer and sociologist W.E.B. Du Bois, designed as an instructional unit in an introduction to mass communication course which can help make students aware of the roles played by ethnic minorities in shaping American and world media. The paper provides numerous details of…

Violence et dire, pour une rhétorique du soin

Directory of Open Access Journals (Sweden)

André Quaderi

Full Text Available Par une approche plurielle (psychopathologie du travail, sciences du langage et psychanalyse et au travers d’une clinique de type groupe de parole en institution gériatrique, il est abordé les phénomènes de violences. Les effets du dire, au niveau du clinicien, induisent des changements de comportements des soignants dont les causes sont abordées. Ainsi, la taylorisation de l’organisation inhibe la relation du soignant à l’autre et fige le travail dans une exécution de tâche. Ces effets délétères sont à rapporter au Thanatos tout comme les effets du dire (interprété comme une rhétorique du soin sont à comprendre du côté de l’Eros.

Mise à jour sur le nouveau vaccin 9-valent pour la prévention du virus du papillome humain

Science.gov (United States)

Yang, David Yi; Bracken, Keyna

2016-01-01

Résumé Objectif Informer les médecins de famille quant à l’efficacité, à l’innocuité, aux effets sur la santé publique et à la rentabilité du vaccin 9-valent contre le virus du papillome humain (VPH). Qualité des données Des articles pertinents publiés dans PubMed jusqu’en mai 2015 ont été examinés et analysés. La plupart des données citées sont de niveau I (essais randomisés et contrôlés et méta-analyses) ou de niveau II (études transversales, cas-témoins et épidémiologiques). Des rapports et recommandations du gouvernement sont aussi cités en référence. Message principal Le vaccin 9-valent contre le VPH, qui offre une protection contre les types 6, 11, 16, 18, 31, 33, 45, 52 et 58 du VPH, est sûr et efficace et réduira encore plus l’incidence des infections à VPH, de même que les cas de cancer lié au VPH. Il peut également protéger indirectement les personnes non immunisées par l’entremise du phénomène d’immunité collective. Un programme d’immunisation efficace peut prévenir la plupart des cancers du col de l’utérus. Les analyses montrent que la rentabilité du vaccin 9-valent chez les femmes est comparable à celle du vaccin quadrivalent original contre le VPH (qui protège contre les types 6, 11, 16 et 18 du VPH) en usage à l’heure actuelle. Toutefois, il faut investiguer plus en profondeur l’utilité d’immuniser les garçons avec le vaccin 9-valent contre le VPH. Conclusion en plus d’être sûr, le vaccin 9-valent protège mieux contre le VPH que le vaccin quadrivalent. Une analyse coûtefficacité en favorise l’emploi, du moins chez les adolescentes. Ainsi, les médecins devraient recommander le vaccin 9-valent à leurs patients plutôt que le vaccin quadrivalent contre le VPH.

Culture du bambou : diversification des moyens de subsistance des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Culture du bambou : diversification des moyens de subsistance des petits producteurs de tabac du sud de la province de Nyanza, au Kenya - phase II. Au cours de la première phase du projet (projet no 103765), les chercheurs ont effectué une analyse de marché pour le bambou et les produits du bambou, comparé les ...

Archives: les cahiers du cread

African Journals Online (AJOL)

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Connaissances des médecins généralistes de Mohammedia (Maroc) concernant le dépistage du cancer du sein

Science.gov (United States)

Zine, Karima; Nani, Samira; Lahmadi, Imad Ait; Maaroufi, Abderrahmane

2016-01-01

Introduction Le cancer du sein représente un problème de santé publique majeur au Maroc. C'est le premier cancer chez la femme. L'objectif de ce travail était d'évaluer les connaissances des médecins généralistes (MG) en matière de dépistage du cancer du sein dans la préfecture de Mohammedia Maroc. Méthodes Nous avons mené une étude transversale, descriptive, exhaustive incluant les 97 MG exerçant dans les établissements de soins de santé de base du secteur public et privé de la province de Mohammedia. Résultats Le taux de participation était de 87%. L'âge moyen des MG était de 49,6 ± 8,1. Quatre-vingt pour cent (n=55) des MG ont donné une incidence incorrecte, 77,6% (n=85) ont reconnu l'existence d'un plan national de prévention et de contrôle du cancer (PNPCC) au Maroc, et 67,1 des MG ont rapporté l'existence d'un registre du cancer au Maroc. Le secteur d'activité était associé significativement avec les connaissances des MG sur le PNPCC et sur l'existence d'un guide de détection précoce du cancer du sein avec respectivement (p=0,003 et p=0,001). Une association significative entre l'ancienneté et l'existence d'un guide de détection précoce du cancer du sein et d'un registre du cancer du sein a été retrouvée avec (respectivement p=0,005 et p=0.002). Conclusion À la lumière de ces résultats il faudra renforcer les connaissances et les pratiques des MG par la promotion de la formation initiale et continue sur le dépistage. PMID:27800098

Depleted uranium (DU) mobility in the natural environment

International Nuclear Information System (INIS)

Ragnarsdottir, K.V.

2002-01-01

In 1999 the Balkan's conflict lead NATO war planes to leave 10x10 3 kg of depleted uranium (DU) in the environment of Kosovo and neighbouring states (UNEP, 2001). DU behaves in the same manner in the environment as natural uranium and it can be traced with isotopic analysis due to the fact that DU has the isotopic composition of 0.2% 235 U and 99.8% 2 38 U as opposed to natural uranium which has 0.7% 2 35 U and 99.3% 2 38 U. DU is a waste product of the nuclear industry which enrich nuclear fuel by 2 35 U. Large stock piles of DU therefore exist in countries that produce nuclear energy and/or nuclear weapons. The DU is given to the weapons industry for free (or cheap) and has been a popular choice for armour penetrating arsenal due to the high density of uranium (19 g cm -3 ) and therefore its high penetrating power. Indeed the arsenal used in Kosovo consisted of DU penetrators that were shot from A-10 aeroplanes. They weigh roughly 300 g and have the shape of a fat 9 cm long pencil. (author)

Sorrow Songs and Mbira Music: Du Bois, Mapfumo, and the Power of Music

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Shelia Bassoppo-Moyo

2012-10-01

Full Text Available This article examines how music functions as social commentary on a group’s lived experience and as a tool to inform identity. Music is a data source that articulates historical and cultural contexts and can thus be utilized as social commentary to socially construct the identity of people of African ancestry and descent. The "sorrow songs" are the music genre created by slaves in the American South and were considered by W. E. B. Du Bois as the most important historical narrative for African Americans. In comparison, the more contemporary "mbira music" or Chimeranga (rebellion songs of Thomas Mapfumo, led the liberation struggle against colonialism in Zimbabwe. His music played a journalistic role in communicating with the masses. Several theoretical perspectives were employed in this study which included Du Bois’ inductive, empirical framework for the study of "the Negro problems"; Georg Simmel’s perspective on the role of music in society; Berger and Luckmann’s social construction of reality; and O'Shaughnessy and Stadler's social construction of the media. This paper uses content analysis to analyze the musical lyrics of both genres. These musical forms shed light on Du Bois' understanding of the veil and double consciousness within the African American experience and Zimbabwe's struggle for liberation respectively. Points of intersection between the two genres provide insight into how music creates knowledge and constructs social reality.

L'avenir du Moyen-Orient et de l'Afrique du Nord passe par la ...

International Development Research Centre (IDRC) Digital Library (Canada)

10 janv. 2013 ... Centre de recherches pour le développement international Gouvernement du Canada ... du Nord passe par la croissance partagée et l'économie de marché ... vivant en région éloignée aient un accès égal aux possibilités économiques. ... visant à trouver de nouveaux modes d'action pouvant contribuer au ...

Some aspects of sulphite metabolism in plants; Quelques aspects du metabolisme du sulfite chez les vegetaux

Energy Technology Data Exchange (ETDEWEB)

Perez-Milan, Hernan

1958-05-15

As sulphite appears to be an intermediate substance in the degradation of sulphur-containing amino acids, and has an important metabolic role, notably for plants, this research thesis aims at comparing transformations which may occur for a same chemical compound (the sulphite) in various organisms belonging to different species or kingdoms. More particularly, the author studied the formation of sulphite in vegetal tissues, and the oxidisation of sulphite into sulfate within these tissues. In vitro experiments have been performed with oat, while in vivo experiments have been performed on tobacco plants [French] Le sulfite apparait comme une substance intermediaire de la degradation des acides amines soufres. Son role dans la biosynthese de certains d'entre eux, problematique chez les mammiferes, est certain chez les oiseaux, qui, a cet egard, se comportent comme des autotrophes partiels, puisqu'ils reduisent le sulfate en sulfite. On s'apercoit ainsi qu'un degre d'evolution moindre confere au sulfite une importance metabolique plus grande. On peut s'attendre a trouver chez les vegetaux un role encore accru pour le sulfite. Le present travail entre dans ce cadre d'etudes comparees des transformations que peut subir un meme type de compose chimique: le sulfite, dans divers organismes appartenant a des especes ou a des regnes differents. Les donnees acquises exposees ici auront trait aux deux points suivants: I - La formation du sulfite dans les tissus vegetaux, II - L'oxydation dans ces tissus, du sulfite en sulfate. L'avoine nous a servi comme materiel de depart pour les experiences faites in vitro. Cette plante presente en effet l'avantage de se bien cultiver en toutes saisons, de se broyer facilement, et d'etre depourvue au maximum de mucilages, de resines, substances genantes pour l'analyse ulterieure. Les essais faits in vivo, ont mis en oeuvre des plants de tabac, qui permettent une nutrition par le petiole ou par la tige particulierement aisee.

Harmful effects of DU in the offspring of the military personnel employed in DU contaminated regions

International Nuclear Information System (INIS)

Atlagic, N.; Lisov, Lj.; Barjaktarovic, V.; Djurovic, B.; Spasic, Jokic V.

2008-01-01

Full text: In 1999, during the NATO attacks on Kosovo, from AT-10 aircraft has been shot over 50000 30-mm projectiles which contained approximately 15 tones of DU. Besides DU, projectiles contained products of DU radioactive decay as well as americium, neptunium, plutonium and technetium. Due to DU contamination military personnel employed near hit targets could be contaminated and irradiated. Besides the harmful effects in exposed military personnel, harmful effects were noticed in their offsprings, too. DU can cause genetic and teratogenic harmful effects in the embryos/fetus. It is concentrated in semen of contaminated males and also can contaminate the embryo/fetus through placenta. DU, as a toxic and radioactive element, can cause variety of harmful effects, but the most important are the effects on DNA which are the cause of many diseases. The aim of this paper is to examine is there any change in the incidence in heritable effects, congenital malformations, malignant diseases, endocrine and immune disorders. For that reason we compared the incidence of these diseases in the offspring's of military personnel born from 1995-1999 (1204) with the children born from 2000-2004 (1131) / and 2005-2008. Our results showed higher incidence of congenital malformations and chromosomal abnormalities (12.55 % vs 4.57 %), with highest incidence of foot deformity-52.04 % and hip deformity. These abnormalities were followed with immunological disorders and dysfunction of the urine bladder. Endocrine diseases were increased too(2.16 % :1.63 %). In this period higher incidence of malignant diseases was not noticed, but in the second period (from 5-9 year) after 1999, higher incidence of malignant hematological diseases was noticed, as well as Down Sy. During the conflicts future parents as well as embryo/fetus are exposed to many harmfulness and it is very hard to separate the influence of each. Considering the fact that the effects of DU, could be delayed and synergistic with

Accroissement du recours aux politiques fiscales dans la lutte ...

International Development Research Centre (IDRC) Digital Library (Canada)

Incidence de la hausse des taxes sur le tabac et du prix des produits du tabac en Ukraine, en Russie et au Bélarus. La recherche destinée aux responsables des politiques de l'Ukraine, de la Russie et du Bélarus mettra en évidence la façon dont les mesures de taxation des produits du tabac peuvent contribuer.

Distribution spatiale du singe à ventre rouge, Cercopithecus ...

African Journals Online (AJOL)

danger et endémique du Dahomey Gap est très peu documenté au Togo. Pour connaître sa ..... chaque secteur prospecté ainsi que celui du complexe en entier. ..... 2008-009 portant loi-cadre sur l'environnement au Togo. JO du 06 juin. 2008.

Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest

Energy Technology Data Exchange (ETDEWEB)

Kilymis, D. A.; Delaye, J.-M., E-mail: jean-marc.delaye@cea.fr [CEA Marcoule, DEN/DTCD, Service d’Etude et Comportement des Matériaux de Conditionnement, BP17171 30207 Bagnols-sur-Cèze Cedex (France)

2014-07-07

In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO{sub 2} content of the glass, which promotes densification due to the open structure of SiO{sub 4} tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, as has been previously observed.

Deformation mechanisms during nanoindentation of sodium borosilicate glasses of nuclear interest.

Science.gov (United States)

Kilymis, D A; Delaye, J-M

2014-07-07

In this paper we analyze results of Molecular Dynamics simulations of Vickers nanoindentation, performed for sodium borosilicate glasses of interest in the nuclear industry. Three glasses have been studied in their pristine form, as well as a disordered one that is analogous to the real irradiated glass. We focused in the behavior of the glass during the nanoindentation in order to reveal the mechanisms of deformation and how they are affected by microstructural characteristics. Results have shown a strong dependence on the SiO2 content of the glass, which promotes densification due to the open structure of SiO4 tetrahedra and also due to the strength of Si-O bonds. Densification for the glasses is primarily expressed by the relative decrease of the Si-O-Si and Si-O-B angles, indicating rotation of the structural units and decrease of free volume. The increase of alkali content on the other hand results to higher plasticity of the matrix and increased shear flow. The most important effect on the deformation mechanism of the disordered glasses is that of the highly depolymerized network that will also induce shear flow and, in combination with the increased free volume, will result in the decreased hardness of these glasses, as has been previously observed.

Influence of Some Nuclear Waste on The Durability and Mechanical Properties of Borosilicate glass

International Nuclear Information System (INIS)

El-Alaily, N.A.

2003-01-01

Various glass systems have been shown to be suitable for producing waste glass forms that are thermally and mechanically stable and exhibit good chemical durability. In this study borosilicate glass containing sodium oxide and aluminum oxide was prepared as a host for high level nuclear waste. The glass durability when the samples were immersed either in distilled water or ground water at 70 degree was studied. The density, porosity and mechanical properties were also investigated. The effects of exposing the samples immersed in groundwater to gamma rays in the glass durability and all other mentioned properties were also studied. The results showed that immersing the glass in ground water causing a decrease in the glass durability. The exposure of the glass immersed in ground water to the gamma rays increases the durability of the glass. The mechanical properties of the prepared glass were good. Although these properties decrease for the corroded glass but they were still good

Le plurilinguisme du perroquet

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Manuel Mühlbacher

2012-05-01

Full Text Available La figure du perroquet occupe une position ambiguë face à la question de la traduction. Il est capable d’imiter des paroles en toutes les langues, mais il n’est capable d’en comprendre aucune — il ne peut que répéter des sons, c’est-à-dire des signifiants. Le traducteur semble faire le contraire quand il passe d’une langue à une autre en tâchant de transmettre une signification semblable par d’autres signes. L’article vise à discuter le rôle du traducteur et sa relation, éventuellement équivoque, au perroquet, en analysant la traduction allemande de Trois Contes par André Stoll et Cora van Kleffens. Un décalage au niveau sémantique peut éclairer l’interprétation du texte, par exemple en explicitant des allusions sous-jacentes, tandis que le transfert de la syntaxe française en allemand pose souvent des problèmes considérables. Comment le traducteur peut-il reproduire des structures syntaxiques qui n’existent pas en allemand, mais qui ne cessent de revenir dans le texte français ? Que faire si le texte se met à jouer au perroquet et finit par se singer lui-même ? André Stoll et Cora van Kleffens ont su trouver des stratégies pour affronter ces difficultés.The figure of the parrot holds an ambiguous position towards the question of translation. It is able to imitate all languages, but it will never understand any of them – its only skill is to mimic sounds, i.e. mere signifiers. On the contrary, the translator seems to be the antithesis of the parrot when he moves from one language to another. He endeavours to convey a similar meaning, but by different signs. The article aims at discussing the role of the translator and his or her eventually equivocal relation to the parrot by means of analysing the German translation of Trois Contes by André Stoll and Cora van Kleffens. Whereas a semantic divergence can result in a different tendency on the level of interpretation, as in the case of an underlying

College of DuPage District 502 Educational Needs Assessment (Total Sample Summary).

Science.gov (United States)

Rice, Gary

In spring 1987, the Gallup Organization conducted a telephone survey for the College of DuPage (COD) in Illinois to determine community perceptions of the college's role in the community; community awareness of COD and its competitors; perceptions of current college services; importance of factors in selecting an educational program; interest in…

Cirque du Monde en tant qu’intervention en santé

Science.gov (United States)

Fournier, Cynthia; Drouin, Mélodie-Anne; Marcoux, Jérémie; Garel, Patricia; Bochud, Emmanuel; Théberge, Julie; Aubertin, Patrice; Favreau, Gil; Fleet, Richard

2014-01-01

Résumé Objectif Présenter le programme Cirque du Monde du Cirque du Soleil et son potentiel en tant qu’intervention en soins de santé de première ligne pour les médecins de famille. Sources des données Une revue de la littérature menée dans les bases de données PubMed, Cochrane Library, PsycINFO, La Presse, Eureka, Google Scholar et Érudit à l’aide des mots-clés circus, social circus, Cirque du Monde et Cirque du Soleil. Une initiative à Montréal nommée Espace Transition qui s’inspire directement de Cirque du Monde. Communication personnelle avec le conseiller principal en formation en cirque social du Cirque du Soleil. Sélection d’études Les 50 premiers articles ou sites Internet répertoriés pour chaque mot-clé dans chacune des bases de données ciblées ont été révisés sur la base des titres et des résumés, s’il s’agissait d’un article, ou sur la base du titre et du contenu de la page, s’il s’agissait d’une page Internet. Ensuite, les articles et les sites Internet qui étudiaient un aspect du cirque social ou qui présentaient une intervention impliquant le cirque étaient retenus pour une révision. Aucune contrainte d’année de publication n’a été appliquée étant donné qu’on cherchait une littérature générale sur le cirque social. Synthèse Aucun article n’a été trouvé sur le cirque social en tant qu’intervention en santé. Nous avons trouvé une étude sur l’utilisation du cirque en tant qu’intervention en milieu scolaire. Cette étude a démontré une augmentation de l’estime personnelle des enfants grâce à l’intervention. Nous avons trouvé une étude sur l’utilisation du cirque en tant qu’intervention sur une réserve amérindienne. Cette étude présente des résultats qualitatifs non spécifiques au programme du cirque social. Les autres articles répertoriés n’étaient que des descriptions du cirque social. Un site web concernant l’utilisation du cirque social pour

A kinetic model for borosilicate glass dissolution based on the dissolution affinity of a surface alteration layer

International Nuclear Information System (INIS)

Bourcier, W.L.; Peiffer, D.W.; Knauss, K.G.; McKeegan, K.D.; Smith, D.K.

1989-11-01

A kinetic model for the dissolution of borosilicate glass is used to predict the dissolution rate of a nuclear waste glass. In the model, the glass dissolution rate is controlled by the rate of dissolution of an alkali-depleted amorphous surface (gel) layer. Our model predicts that all components concentrated in the surface layer, affect glass dissolution rates. The good agreement between predicted and observed elemental dissolution rates suggests that the dissolution rate of the gel layer limits the overall rate of glass dissolution. The model predicts that the long-term rate of glass dissolution will depend mainly on ion concentrations in solution, and therefore on the secondary phases which precipitate and control ion concentrations. 10 refs., 5 figs., 1 tab

Une force venant du futur chercherait à saboter l'expérience du LHC...

CERN Multimedia

Scappaticci, Bruno

2009-01-01

"A quelques jours de la reprise de l'expérience du LHC, on ne parle plus de la menace d'un trou noir, mais deux physicines souteinnent aujourd'hui une tout autres hypothèse: la nature, depuis le futur, va continuer de contrarier les travaux du Cern, afin d'éviter à l'Homme de mettre le doigt là où il ne faut pas..." (1.5 pages)

Effects of solution chemistry and atmosphere on leaching of alkali borosilicate glass

International Nuclear Information System (INIS)

Hermansson, H.P.; Christensen, H.; Clark, D.E.; Werme, L.

1983-01-01

The leaching behavior of two alkali-borosilicate glasses containing 9 wt % simulated fission products and 1.6 wt % uranium oxide has been studied. Samples were exposed to one of eight types of leachants including doubly distilled water, simulated ground silicate water, a brine solution, and solutions containing various concentrations of iron, aluminum or sodium maintained at either 25 0 C, 40 0 C or 90 0 C for up to 182 days. The most aggressive leachants were the solutions containing sodium (excluding brine) and simulated ground silicate water. These solutions increased the extent of leaching by a factor of 2 to 3 over that for distilled water for one of the glasses. A partially protective surface film rich in magnesium, potassium, and chlorine was formed on the glasses exposed to the brine solution. In order to evaluate the effects of atmosphere on leaching, samples were also immersed in doubly distilled water over which the relative concentrations of oxygen, nitrogen and carbon dioxide were varied. Increasing the carbon dioxide concentration from 0 to 50% resulted in a factor of 3 increase in the leaching rate

Direct conversion of plutonium-containing materials to borosilicate glass for storage or disposal

International Nuclear Information System (INIS)

Forsberg, C.W.; Beahm, E.C.

1995-01-01

A new process, the Glass Material Oxidation and Dissolution System (GMODS), has been invented for the direct conversion of plutonium metal, scrap, and residue into borosilicate glass. The glass should be acceptable for either the long-term storage or disposition of plutonium. Conversion of plutonium from complex chemical mixtures and variable geometries into homogeneous glass (1) simplifies safeguards and security; (2) creates a stable chemical form that meets health, safety, and environmental concerns; (3) provides an easy storage form; (4) may lower storage costs; and (5) allows for future disposition options. In the GMODS process, mixtures of metals, ceramics, organics, and amorphous solids containing plutonium are fed directly into a glass melter where they are directly converted to glass. Conventional glass melters can accept materials only in oxide form; thus, it is its ability to accept materials in multiple chemical forms that makes GMODS a unique glass making process. Initial proof-of-principle experiments have converted cerium (plutonium surrogate), uranium, stainless steel, aluminum, and other materials to glass. Significant technical uncertainties remain because of the early nature of process development

Physical and optical properties of lithium borosilicate glasses doped with Dy3+ ions

Science.gov (United States)

Ramteke, D. D.; Gedam, R. S.; Swart, H. C.

2018-04-01

The borosilicate glasses with Dy3+ ions were prepared by the melt quench technique with varying concentration of Dy2O3. The glasses were characterized by the density calculation, absorbance and photoluminescence (PL) spectroscopy measurements. Density and molar volume of the glasses increases with increase in Dy3+ ions in the glass matrix. This behavior is correlated with the higher molecular weight and larger ionic radius of Dy3+ ion compared to the other constituents of glass matrix. Emission of Dy3+ doped glasses showed three bands at 482, 573 and at 665 nm which correspond to 6H15/2 (blue), 6H13/2 (yellow) and 6H11/2 (red) transitions. The emission spectra of glasses with different concentration of Dy3+ ions shows that, glasses with 0.5 mol% of Dy2O3 shows highest emission and decreases with further doping. CIE 1931 chromaticity diagram showed that the emission of these glasses was in the white region. Photographs of these glasses under 349 nm Light emitting diode excitation also confirmed the white light emission from these glasses.

Luminescence properties of Dy3+ doped lithium zinc borosilicate glasses for photonic applications

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N. Jaidass

2018-03-01

Full Text Available Different concentrations of Dy3+ ions doped lithium zinc borosilicate glasses of chemical composition (30-x B2O3 - 25 SiO2 -10 Al2O3 -30 LiF - 5 ZnO - x Dy2O3 (x = 0, 0.1, 0.5, 1.0 and 2.0 mol% were prepared by the melt quenching technique. The prepared glasses were investigated through X-ray diffraction, optical absorption, photoluminescence and decay measurements. Intensities of absorption bands expressed in terms of oscillator strengths (f were used to determine the Judd-Ofelt (J-O intensity parameters Ωλ (λ = 2, 4 and 6. The evaluated J-O parameters were used to determine the radiative parameters such as transition probabilities (AR, total transition probability rate (AT, radiative lifetime (τR and branching ratios (βR for the excited 4F9/2 level of Dy3+ ions. The chromaticity coordinates determined from the emission spectra were found to be located in the white light region of CIE chromaticity diagram. Keywords: Condensed matter physics, Engineering, Materials science

Matere z motnjami v duševnem razvoju

OpenAIRE

Kolarič, Sandra

2015-01-01

S pregledom tuje literature in že opravljenih raziskav v tujini smo v teoretičnem delu magistrske naloge zajeli značilnosti mater z motnjami v duševnem razvoju, dejavnike, ki vplivajo na uspešnost opravljanja materinske vloge, ter pravice oseb z motnjami v duševnem razvoju do starševstva, v povezavi z zakonodajo na slovenskem. Navedli smo vzroke za omejevanje reprodukcije pri ženskah z motnjami v duševnem razvoju in problematiko odvzema skrbništva materam z motnjami v duševnem razvoju nad otr...

LE RÈGNE DU SÉMIOTIQUE : Fondement de la poéticité du langage romanesque chez Ken Bugul

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Christian Ahihou

2011-11-01

Full Text Available Le règne du sémiotique dans le langage a pour effet le passage au premier plan des formes du langage que sont notamment la musicalité et les jeux de mots. C’est vrai pour Ken Bugul qui a affirmé que : « La langue maternelle, c’est des sentiments, des odeurs, des sonorités, des attouchements. C’est la langue de ma mère et non la langue de la mère de tout le monde ». Certes, le signe ne perd pas sa signification, mais il subit la domination du caractère poétique du langage qui le porte.

The structure of phosphate and borosilicate glasses and their structural evolution at high temperatures as studied with solid state NMR spectroscopy: Phase separation, crystallisation and dynamic species exchange

International Nuclear Information System (INIS)

Wegner, S.; Van Wullen, L.; Tricot, G.; Tricot, G.

2010-01-01

In this contribution we present an in-depth study of the network structure of different phosphate based and borosilicate glasses and its evolution at high temperatures. Employing a range of advanced solid state NMR methodologies, complemented by the results of XPS, the structural motifs on short and intermediate length scales are identified. For the phosphate based glasses, at temperatures above the glass transition temperature Tg, structural relaxation processes and the devitrification of the glasses were monitored in situ employing MAS NMR spectroscopy and X-ray diffraction. Dynamic species exchange involving rapid P-O-P and P-O-Al bond breaking and reforming was observed employing in situ 27 Al and 31 P MAS NMR spectroscopy and could be linked to viscous flow. For the borosilicate glasses, an atomic scale investigation of the phase separation processes was possible in a combined effort of ex situ NMR studies on glass samples with different thermal histories and in situ NMR studies using high temperature MAS NMR spectroscopy including 11 B MAS, 29 Si MAS and in situ 29 Si{ 11 B} REAPDOR NMR spectroscopy. (authors)

Mineralogical textural and compositional data on the alteration of basaltic glass from Kilauea, Hawaii to 300 degrees C: Insights to the corrosion of a borosilicate glass waste-form

International Nuclear Information System (INIS)

Smith, D.K.

1990-01-01

Mineralogical, textural and compositional data accompanying greenschist facies metamorphism (to 300 degrees C) of basalts of the East Rift Zone (ERZ), Kilauea, Hawaii may be evaluated relative to published and experimental results for the surface corrosion of borosilicate glass. The ERZ alteration sequence is dominated by intermittent palagonite, interlayered smectite-chlorite, chlorite, and actinolite-epidote-anhydrite. Alteration is best developed in fractures and vesicles where surface reaction layers root on the glass matrix forming rinds in excess of 100 microns thick. Fractures control fluid circulation and the alteration sequence. Proximal to the glass surface, palagonite, Fe-Ti oxides and clays replace fresh glass as the surface reaction layer migrates inwards; away from the surface, amphibole, anhydrite, quartz and calcite crystallize from hydrothermal fluids in contact with the glass. The texture and composition of basaltic glass surfaces are similar to those of a SRL-165 glass leached statically for sixty days at 150 degrees C. While the ERZ reservoir is a complex open system, conservative comparisons between the alteration of ERZ and synthetic borosilicate glass are warranted. 31 refs., 2 figs

Présentation du volume

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Ana Zwitter Vitez

2012-12-01

Full Text Available Dans de nombreuses disciplines scientifiques, le discours parlé représente depuis quelques décennies un objet de recherche proéminent. Ce fait s’explique probablement par deux caractéristiques principales du discours parlé: la structure complexe de sa matérialité et les fonctions variées de différentes pratiques langagières. C’est pourquoi le présent numéro réunit les articles basés sur les approches actuelles du discours parlé et sur les pratiques langagières spécifiques. Le volume est introduit par deux articles interdisciplinaires: Peter Garrard et Ahmed Samrah présentent le domaine de la pathologie du langage en donnant une revue fouillée sur les approches actuelles de l’analyse linguistique lors de la détection de la maladie d’Alzheimer, tandis que Harry Hollien donne un aperçu structuré sur le domaine de la phonétique judiciaire destiné à dévoiler l’identité des locuteurs et de détecter la déception dans le discours parlé. Les analyses explorant l’acquisition du langage commencent par l’article de Katharina Zipser qui examine la progression de structures grammaticales en les mettant en comparaison avec la compétence des apprenants et continuent par l’étude de Meta Lah proposant une évaluation des documents audiovisuels proposés aux apprenants de langue étrangère. Vesna Požgaj Hadži, Damir Horga et Tatjana Balažic Bulc remettent en question la corrélation entre la compétence linguistique et la fluence linguistique auprès de locuteurs non-maternels et l'analyse de Gemma Santiago Alonso aborde l'acquisition de l'article défini dans le langage enfantin. Les articles suivants se réunissent autour du domaine de l'interprétation: Jana Zidar Forte présente une approche actuelle dans l'entrainement d'interprètes, Lea Burjan analyse les phénomènes issus de la pratique de l'interprétation juridique et Simona  Šumrada traite de la reformulation dans le discours de la traduction et de

Impact du BAO électronique sur l’intention d’achat du consommateur:Le rôle modérateur de l’âge et du genre

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Manel Hamouda

2014-03-01

Full Text Available Les variables sociodémographiques tels que l’âge et le genre sont considérées comme des variables très importantes en comportement du consommateur que ce soit dans un contexte réel ou dans un environnement virtuel. A cet égard, cette recherche se propose d’étudier le rôle de l’âge et du genre dans la relation entre l’intention d’achat du consommateur et le Bouche à oreille électronique (BAO électronique. Les données utilisées dans cette recherche ont été collectées à travers une étude empirique menée sur un échantillon de 204 internautes. Les résultats indiquent que le genre et l’âge constituent deux variables susceptibles de modérer l’intention d’achat du consommateur suite à une exposition à un BAO électronique. Les implications inhérentes pour les chercheurs ainsi que pour les praticiens ont été par ailleurs suggérées.

Les Offices du cinéma éducateur et l’émergence du parlant : l’exemple de l’Office de Nancy

OpenAIRE

Laborderie, Pascal

2014-01-01

Quelle fut la politique des Offices du cinéma scolaire et éducateur durant la période de généralisation du cinéma parlant ? Une première présentation du dispositif de l’Union française des offices du cinéma éducateur laïque permet de décrire les usages du cinéma par les instituteurs, soit dans leurs enseigne­ments (le cinéma scolaire), soit dans l’éducation des adolescents et des adultes (le cinéma éducateur). Puis une étude de l’Office régional d’enseignement cinématographique de Nancy, à pa...

Participation des médecins généralistes de la province de Benimellal (Maroc) dans le dépistage du cancer du col

Science.gov (United States)

Nani, Samira; Benallal, Mohamed; Hassoune, Samira; Kissi, Dounia; Maaroufi, Abderrahmane

2013-01-01

Introduction Au Maroc, chaque année il y aurait environ 2000 nouveaux cas de cancer du col et les 2/3 des cas sont pris en charge à un stade très avancé. Nous avons mené une étude transversale, exhaustive incluant les 71 médecins généralistes exerçant dans les établissements de soins de santé de base du secteur public et privé de la province de Benimellal. Le but était d’évaluer leurs connaissances et leur participation au dépistage du cancer du col. Méthodes Nous avons mené une étude transversale, exhaustive incluant les 71 médecins généralistes exerçant dans les établissements de soins de santé de base du secteur public et privé de la province de Benimellal. Le but était d’évaluer leurs connaissances et leur participation au dépistage du cancer du col. Résultats Le niveau de connaissance était relativement modeste, 22 médecins généraliste avaient répondu à la question sur l'incidence du cancer du col au Maroc, Parmi eux (81,8%) avaient donné une réponse incorrecte. L'Herpes Papilloma virus comme facteur de risque du cancer du col a été identifié par seulement 21% des médecins généralistes. La participation au dépistage était également défaillante, 92,8% n'avaient jamais pratiqué le FCV chez leurs patientes à cause principalement du manque de formation (95,5%). Conclusion Les résultats montrent la nécessité d'améliorer les connaissances théoriques et pratique des médecins généralistes concernant le dépistage du cancer du col. PMID:23785557

Séroprévalence et facteurs associés à l’acceptation du Conseil et Dépistage Volontaire du VIH chez l’enfant à Lubumbashi, République Démocratique du Congo

Science.gov (United States)

Ngwej, Dieudonné Tshikwej; Mukuku, Olivier; Malonga, Françoise Kaj; Luboya, Oscar Numbi; Kakoma, Jean-Baptiste Sakatolo; Wembonyama, Stanis Okitotsho

2017-01-01

Résumé Introduction Malgré le dépistage du VIH proposé lors de la naissance ou au cours des consultations préscolaires, la proportion des enfants qui croissent ou décèdent sous statut sérologique au VIH inconnu est importante en République Démocratique du Congo (RDC). L’objectif de cette étude était de déterminer la séroprévalence au cours d’un dépistage volontaire et d’identifier les facteurs associés à l’acceptation du conseil et dépistage du VIH (CDV) en dehors de la maladie ou de toute exposition au VIH dans une population pédiatrique à Lubumbashi, RDC. Méthodes Il s’agissait d’une étude prospective transversale à visée analytique menée du 1er août 2006 au 31 septembre 2007. Elle avait été réalisée dans 4 centres communautaires de CDV répartis dans 4 zones de santé de la ville de Lubumbashi en RDC (Lubumbashi, Ruashi, Kampemba et de Kenya). L’étude avait consisté à faire le dépistage volontaire du VIH chez les enfants de moins de 15 ans. Les caractéristiques sociodémographiques et les paramètres relatifs au conseil et dépistage volontaire ont été étudiés. Les analyses statistiques descriptives usuelles et une régression logistique ont été réalisées. Résultats Sur 463 enfants dépistés du VIH, 41 (8,9%; IC 95%: 6,5%-11,9%) ont été testés positifs. L’acceptation du conseil et dépistage volontaire du VIH en dehors de la maladie ou de l’exposition au VIH était significativement plus élevée lorsque l’enfant était âgé de plus de 2 ans (Odds ratio ajusté (ORa) = 3,6 [IC 95%: 1,1-12,2]), lorsque le statut sérologique du VIH des parents était négatif ou inconnu (ORa = 27,4 [IC 95%: 9,4-80,0]), lorsque l’un ou l’autre ou les deux parents biologiques étaient en vie (ORa = 24,9 [IC 95%: 2,4-250,8]) et lorsque la connaissance du lieu de dépistage était fait par des moyens autres que le professionnel de santé (ORa = 2,9 [IC 95%: 1,0-7,9]). Conclusion Notre étude montre une forte

Archéologie d’un parasite du cheval

OpenAIRE

Dufour, Benjamin; Bailly, Matthieu Le

2017-01-01

Oxyuris equi, l’oxyure du cheval, est un vers parasite spécifique des équidés régulièrement mis en évidence lors des études paléoparasitologiques. Nous proposons ici une synthèse originale entre les mentions de ce parasite connues dans la bibliographie et les textes anciens, avec des données inédites issues de nos recherches en paléoparasitologie. Cette compilation des données montre que la plus ancienne observation de l’oxyure du cheval date du milieu du Ier millénaire avant notre ère en Asi...

CHOEUR DU CERN

CERN Multimedia

CHOEUR DU CERN

2010-01-01

Les répétitions du chœur du CERN reprendront le mercredi 15 septembre à 20.00 heures à l’amphithéâtre principal – bâtiment 500. Au programme la préparation de notre concert de Noël avec la Missa Brevis, KV115, de Léopold Mozart et de la musique de Noël d’Europe. Les personnes qui aiment chanter, notamment des sopranes et des ténors, sont les bienvenues. Pour tout contact s’adresser à : Baudouin Bleus - (tél.CERN 767 82 44) -(baudouin.bleus@cern.ch) ou Martin Gatehouse ( martin.gatehouse@wanadoo.fr) ou Jean-Paul Diss (jean-pauldiss@wanadoo.fr).  

DU weaponry: a view on facts and deceptions

International Nuclear Information System (INIS)

Joksimovich, V.

2002-01-01

The paper summarizes the results of literature research conducted by the author on the use of depleted uranium (DU) weaponry. The research was initiated during the NATO bombing of Yugoslavia in 1999 with an objective of searching for facts in the presence of massive deceptions staged by the huge propaganda machinery of DU weaponry use proponents. The U.S. made use of DU penetrators in the Persian Gulf war as well as in the Balkan wars both in Bosnia and Kosovo. Brief science and history backgrounds are provided including overviews of DU uses and abuses in these three wars. The U.S./NATO public pronouncements have been centered around the theme that there has been no proven link between DU and cancers. In the author's view, these types of carefully word engineered statements are motivated by possible compensation and cleanup claims rather than supported by hard data and sound science. Since underlying causes of so called Gulf and Balkan syndromes have not been found despite a decade elapsed since conclusion of the Persian Gulf War, the DU must continue to be a front-line suspect. From the standpoint of public health and safety, it is prudent and responsible to call for a moratorium. DU use in the Kosovo war, which was not sanctioned by the UN Security Council, was reckless in the extreme. (author)

Cost-Effective Remediation of Depleted Uranium (DU) at Environmental Restoration Sites

International Nuclear Information System (INIS)

MILLER, MARK; GALLOWAY, ROBERT B.; VANDERPOEL, GLENN; JOHNSON, ED; COPLAND, JOHN; SALAZAR, MICHAEL

1999-01-01

Numerous sites in the United States and around the world are contaminated with depleted uranium (DU) in various forms. A prevalent form is fragmented DU originating from various scientific tests involving high explosives and DU during weapon-development programs, at firing practice ranges, or in war theaters where DU was used in armor-piercing projectiles. The contamination at these sites is typically very heterogeneous, with discrete, visually identifiable DU fragments mixed with native soil. The bulk-averaged DU activity is quite low, whereas DU fragments, which are distinct from the soil matrix, have much higher specific activity. DU is best known as a dark metal that is nearly twice as dense as lead, but DU in the environment readily weathers (oxidizes) to a distinctive bright yellow color that is quite visible. While the specific activity (amount of radioactivity per mass of soil) of DU is relatively low and presents only a minor radiological hazard, the fact that DU is radioactive and visually identifiable makes it desirable to remove the DU ''contamination'' from the environment. The typical approach to conducting this DU remediation is to use radiation-detection instruments to identify the contaminant and then to separate it from the adjacent soil, packaging it for disposal as radioactive waste. This process can be performed manually or by specialized, automated equipment. Alternatively, a more cost-effective approach might be simple mechanical or gravimetric separation of the DU fragments from the host soil matrix. At SNL/NM, both the automated and simple mechanical approaches have recently been employed. This paper discusses the pros/cons of the two approaches

Autour d'un mystère de l'histoire du livre. Les trois versions du premier volume du Voyage pittoresque de Choiseul-Gouffier

Directory of Open Access Journals (Sweden)

Ioannis Koubourlis

2009-01-01

Full Text Available Dans cet article, il est question d'un grand mystère de l'histoire du livre, celui de l'existence de trois versions différentes du premier volume du Voyage pittoresque de la Grèce (1782 de Choiseul-Gouffier, c'est-à-dire d'un ouvrage majeur pour la floraison des idées philhellènes dans l'Europe des XVIIIe-XIXe siècles. On sait, grâce à la correspondance de l'auteur, qu'il avait pris la décision de réviser son texte dès 1783, en raison de sa candidature pour le poste d'Ambassadeur de France à Constantinople. Par contre, on n'en sait pas davantage sur le lieu et le temps exacts où il a travaillé les deux nouvelles versions, portant également la date 1782, ni d'ailleurs sur les circonstances de leur édition. Sur la base d'une étude comparative des trois versions du texte, qui met l'accent sur l'argumentation avancée chaque fois par l'auteur, nous formulons ici une série d'hypothèses pour l'interprétation de ce mystère, que nous allons examiner dans leurs détails à partir d'une étude de bibliologie qui suivra le présent article.

La maîtrise du temps comme enjeu de lutte

OpenAIRE

Bureau, Marie-Christine; Corsani, Antonella

2012-01-01

Le conflit social autour de la réforme du régime d'assurance chômage des intermittents du spectacle a été marqué par son intensité et par sa durée. La thèse défendue ici est que la maîtrise du temps constitue l’un des enjeux majeurs de ce conflit. L'affrontement sur le terrain économique de la régulation de l'emploi et de l'industrie culturelle s'est doublé de l'affrontement sur le temps. La question du temps ne se limite pas à la régulation du temps de travail, elle concerne la maîtrise du t...

Avallon (Yonne, note sur l’effondrement du petit surplomb du rempart, au chevet de la collégiale Saint-Lazare

Directory of Open Access Journals (Sweden)

Virginie Jolly

2006-09-01

Full Text Available Suite à l’effondrement d’un élément de l’enceinte urbaine durant l’hiver 2004, une intervention a été souhaitée conjointement par le Service Régional de l’Archéologie de Dijon (DRAC Bourgogne et la Municipalité d’Avallon (Yonne. La zone concernée, située à l’est de la ville médiévale, sur le rempart, est en contact direct avec l’esplanade du chevet de la collégiale Saint-Lazare. La configuration escarpée et dangereuse du terrain —instabilité du sol en partie haute et effritement du mur— a l...

Sud du Sahara | Page 10 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Nakacho was one of just a handful of women at this artisanal mining site who had managed to break away from the roles generally ascribed to her gender to become a ... Trouver un juste équilibre entre s'occuper des enfants et générer des revenus est un problème auquel sont confrontées les mères autour du monde.

Portage vaginal du streptocoque du groupe B chez la femme enceinte au niveau de la région de Marrakech

Science.gov (United States)

Bassir, Ahlam; Dhibou, Hanane; Farah, Majdi; Mohamed, Lharmis; Amal, Addebous; Nabila, Souraa; Abderahim, Aboulfalah; Asmouki, Hamid; Soummani, Abderraouf

2016-01-01

Introduction Le streptocoque du groupe B est le principal agent impliqué dans les infections materno-fœtales, les septicémies et les méningites du nouveau-né à terme. L'objectif est de déterminer le taux de portage maternel du streptocoque du groupe B (SGB) à terme. Méthodes Un prélèvement vaginal a été réalisé de manière prospective chez 275 parturientes lors de l'entrée en salle d'accouchement sur une période de 06 mois. Résultats Le taux de portage était de 20,2%. Le portage était variable en fonction de l’âge gestationnel, il constitue 57.5% entre 37 et 38 semaines d'aménorrhée. Aucun des facteurs de risque n'a était statistiquement prédictif du portage maternel du SGB. Conclusion Le dépistage doit être réalisé à partir de 37 semaines d'aménorrhée, et comme le portage est intermittent, un prélèvement négatif ne garantirait pas que le portage soit négatif à l'accouchement. PMID:27222693

Dynamic fracture and fragmentation patterns of borosilicate laminate glasses

Directory of Open Access Journals (Sweden)

Gómez del Río, T.

2009-10-01

Full Text Available The dynamic behaviour of laminate borosilicate glasses (BSG with polyvinylbutiral (PVB interfaces (0,38 mm located at different distances from the impact point have been studied and compared with monolithic glass. The mechanical behaviour under impact loads have been studied using a compression split Hopkinson pressure bar (SHPB. In these experiments, the stress-strain curves of the materials at high loading rates and the capability of transmitting and reflecting the impact energy have been determined. The influence of the position of the interface on the fragmentation statistics of the SHPB recovered fragments has also been considered and analysed according to the published theoretical models.

En este trabajo se ha estudiado los comportamientos dinámicos de un vidrio monolítico de borosilicato y varios laminados de cristal de borosilicato (BSG con intercaras de polyvinylbutiral (PVB (0,38 mm situados a diferentes distancias respecto del punto de impacto. Los resultados de las diferentes configuraciones de laminados se han comparado con el vidrio monolítico. El comportamiento mecánico bajo cargas de impacto se han estudiado realizando ensayos de compresión con una barra Hopkinson (SHPB. A partir de estos experimentos se obtienen las curvas tensión-deformación de los materiales a altas velocidades de carga y su capacidad de transmitir y reflejar la energía del impacto. La influencia de la posición de la interfaz en las estadísticas de la fragmentación de los fragmentos recuperados también se ha considerado y analizado de acuerdo a los modelos teóricos publicados.

Main: 1DU5 [RPSD[Archive

Lifescience Database Archive (English)

Full Text Available 1DU5 トウモロコシ Corn Zea mays L. Zeamatin Precursor. Name=Zlp; Zea Mays Molecule: Zeamatin; Chai...eta Sandwich SWS:ZEAM_MAIZE,P33679|EMBL; U06831; AAA92882.1; -.|PIR; T02075; T02075.|PDB; 1DU5; X-ray; A/B=22-227.|Mai

Aux origines du monde

CERN Multimedia

2004-01-01

"C'est l'histoire d'une aventure humaine, scientifique, international qui a vu le jour il y a cinquante ans, aux confins de la Suisse et du département de l'Ain. Le plus grand laboratoire de physique des particules du monde, le Cern, a été fondé en 1954. Les festivités organisées à l occasion de cet anniversaire connaîtront leur point d'orgue le 16 octobre prochain, avec portes-ouvertes, accueil de personallités et inauguration d'un monumnet spécifique, le Globe de l'innovation" (2 pages)

Le désordre du monde

African Journals Online (AJOL)

sulaiman.adebowale

Le début du XXIe siècle se caractérise par l'accumulation et la consécution ..... Unis a présidé à la naissance aux forceps de cet outil d'équilibre du monde en ... De toute évidence, l'ONU reste l'instrument qui a marqué le siècle dernier,.

Evolution tectono-sédimentaire du bassin de Talara (nord-ouest du Pérou

Directory of Open Access Journals (Sweden)

1987-01-01

Full Text Available Le bassin pétrolier de Talara, dans le nord-ouest du Pérou, est rempli par des séries terrigènes fluvio-deltaïques du Campanien à l'Eocène Supérieur. Cinq cycles de sédimentation (A, B, C, D, E sont définis par des séquences grano-décroissantes d'approfondissement du bassin, à l'exception du cycle B qui résulte de la progradation du système fluviatile. L'activité tectonique distensive qui domine l'évolution du bassin et contrôle la nature et la répartition des sédiments est interrompue, pendant l'Eocène Moyen, lorsque des chevauchements vers le sud-est se mettent en place dans la série tertiaire décollée du socle. Au front des chevauchements actifs, se forment des olistolithes ainsi que des brèches syntectoniques. L'analyse de la déformation en avant des failles inverses montre que les chevauchements se faisaient vers le sud-est et qu'ils affectaient des sédiments peu lithifïés. La cuenca sedimentaria y petrolera de Talara, en el noroeste del Perú, está rellena por secuencias fluvio-deltaicas del Campaniano al Eoceno Superior. Cinco ciclos de sedimentación (A,B,C,D,E están definidos por secuencias grano-decrecientes de hundimiento, excepto el ciclo B que representa una secuencia grano-creciente de progradación fluvial. La tectónica en distensión domina la evolución de la cuenca y también controla el tipo y la distribución de los sedimentos. Sin embargo, durante el Eoceno Medio, suceden cabalgamientos hacia el sureste, dentro de la cubierta sedimentaria terciaria despegada sobre el basamento paleozoico. Olistolitos y brechas tectónicas se forman en la parte frontal de los cabalgamientos donde el análisis de la deformación muestra que éstos se desarrollaron hacia el sureste y que afectaron sedimentos aún no litificados. Talara oil-basin in NW Peru is filled by fluvio-deltaic series of Campanian to Upper Eocene age. Five sedimentation Cycles (A,B,C,D,E are defined by fining-upward sequences resulting from

Effets du barrage sur l'volution du trait de côte | Blivi | Journal de la ...

African Journals Online (AJOL)

Effets du barrage sur l'volution du trait de côte. A. Blivi. Abstract. (J. de la Recherche Scientifique de l'Université de Lomé, 2000, 4(1): 29-42). Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/jrsul.v4i1.16996 · AJOL African Journals Online.

Deep-UV Raman spectroscopic analysis of structure and dissolution rates of silica-rich sodium borosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Windisch, Charles F.; Pierce, Eric M.; Burton, Sarah D.; Bovaird, Chase C.

2011-03-24

As part of ongoing studies to evaluate the relationships between structural variations in silicate glasses and rates of glass dissolution in aqueous media, molecular structures present in sodium borosilicate glasses of composition Na2O.xB2O3.(3-x)SiO2, with x 1 (Na2O/B2O3 ratio 1), were analyzed using deep-UV Raman spectroscopy. The results were quantified in terms of the fraction of SiO4 tetrahedra with one non-bridging oxygen (Q3) and then correlated with Na2O and B2O3 content. Increasing Na2O was found to raise the fraction of Q3 units in the glasses systematically, in agreement with studies on related glasses, and, as long as the value of x was not too high, contribute to higher rates of dissolution in single pass flow-through testing. The finding was obtained across more than one series of silica-rich glasses prepared for independent dissolution studies. In contrast, dissolution rates were less strongly determined by the Q3 fraction when the value of x was near unity and appeared to grow larger upon further reduction of the Q3 fraction. The results were interpreted to indicate the increasingly important role of network hydrolysis in the glass dissolution mechanism as the BO4 tetrahedron replaces the Q3 unit as the charge-compensating structure for Na+ ions. Finally, the use of deep-UV Raman spectroscopy was found to be advantageous in studying finely powdered glasses in cases where visible Raman spectroscopy suffered from weak Raman scattering and fluorescence interference.

Le parcours migratoire de jeunes ruraux du bled du kif

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Khalid Mouna

2015-06-01

Full Text Available Cet article analyse le parcours migratoire des jeunes ruraux originaires des zones de production du cannabis, jeunes qui cherchent à briser les chaînes de soumission et d’humiliation vécues au quotidien. Pour les jeunes concernés par notre étude, la migration constitue un moyen de s’intégrer dans des réseaux transnationaux et ainsi d’entamer une carrière de beznass (commerçant du cannabis. Ce parcours « initiatique » permet à ces jeunes de revenir au bled avec de nouvelles idées, des moyens accrus, et de jouer un rôle actif dans l’économie locale – qui reste pour eux focalisée sur la production de cannabis, cette dernière restant néanmoins officiellement interdite.

Roman contre roman dans l’organisation du manuscrit du Vatican, Regina Latina 1725

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Francis Gingras

2012-08-01

Full Text Available Alors que les développements structuralistes et post-structuralistes ont favorisé la “textualisation” de la littérature médiévale, l’auteur suggère que la recontextualisation de la réception du roman médiéval passe par un retour aux manuscrits. Appliquée au manuscrit du Vatican, Regina Latina 1725, cette hypothèse de recherche révèle une technique de contrepoint que permet la juxtaposition de différents romans et dont, en dernier recours, le lecteur est toujours un peu juge.

Development of Composite Materials Under Ecological Aspects as Recycling Concept For Borosilicate Glass Containing Iron Slags

International Nuclear Information System (INIS)

Khalil, T.K.; Bossert, J.; Aly, H.F.; Bossert, J.

1999-01-01

Composite concept in materials science can be conveniently applied in the waste treatment technology to construct specific t ailor made c omposite materials, in which at least one of the phases is built by the waste material. In this work the applicability of this concept for the fixation and recycling of slags wastes is done, whereby different mixtures of blast furnace slags are mixed with two different borosilicate glasses, which serve as matrix material. Thermal behaviour of the produced compacts were studied. Both melting and powder technology are applied for the fabrication of dense products. The microstructure of sintered samples is investigated by electron microscopy. The mechanical properties such as hardness and fracture toughness are determined by a Vickers technique. An improvement of the fracture toughness of more than 50% over the value for the original glass VG 98 is achieved by slag addition

Etude de l'origine du citronellol dans les vins

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Isabelle Dugelay

1992-09-01

Full Text Available La formation du citronellol à partir du géraniol et du nérol au cours de la fermentation de moûts synthétiques et naturels de raisin par différentes souches de levures a été étudiée. Le géraniol et le nérol sont transformés en citronellol par la levure, ceci de façon plus marquée avec le géraniol. La quantité de citronellol formé dépend de la souche de levure utilisée. D'autres monoterpènes, comme les acétates de géranyle et de néryle et l'α-terpinéol, sont aussi formés au cours de la fermentation. La préparation enzymatique utilisée n'a pas montré d'activités réductases vis-à-vis du géraniol et du nérol pour former du citronellol.

L’empathie comme outil herméneutique du soi: Note sur Paul Ricœur et Heinz Kohut

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Michel Dupuis

2011-01-01

Full Text Available Le bref texte que Paul Ricœur consacre en 1986 à la psychanalyse développée par Heinz Kohut révèle une réinterprétation phénoménologique à la fois du contenu et des fonctions de l'empathie, au total considérée comme un véritable outil à l'œuvre dans l'herméneutique du soi. La vision kohutienne de la constitution du soi et du processus thérapeutique analytique produit une espèce de “dé-sentimentalisation” de l'empathie, en soulignant le rôle crucial du transfert intersubjectif, fort à distance de la théorie (freudienne solipsiste de l'ego.The short text published in 1986 by Paul Ricoeur about Heinz Kohut's psychoanalysis of the self reveals a phenomenological reinterpretation of the content and the functions of empathy, finally considered as an effective tool of the hermeneutics of the self. Kohut's model of constitution of the self and of the therapeutic analytical process produces a kind of “de-sentimentalization” of empathy, pointing to the crucial role of intersubjective transfer, far from a (Freudian solipsistic theory of the ego.

Cirque du Monde as a health intervention

Science.gov (United States)

Fournier, Cynthia; Drouin, Mélodie-Anne; Marcoux, Jérémie; Garel, Patricia; Bochud, Emmanuel; Théberge, Julie; Aubertin, Patrice; Favreau, Gil; Fleet, Richard

2014-01-01

Abstract Objective To present Cirque du Soleil’s social circus program, Cirque du Monde, to explore its potential as a primary health care tool for family physicians. Data sources A review of the literature in PubMed, the Cochrane Library, PsycINFO, LaPresse, Eureka, Google Scholar, and Érudit using the key words circus, social circus, Cirque du Monde, and Cirque du Soleil; a Montreal-based initiative, Espace Transition, modeled on Cirque du Monde; and personal communication with Cirque du Soleil’s Social Circus Training Advisor. Study selection The first 50 articles or websites identified for each key word in each of the databases were examined on the basis of their titles and abstracts in the case of articles, and on the basis of their titles and page content in the case of websites. Articles and websites that explored an aspect of social circuses or that described an intervention that involved circuses were then retained for analysis. Because all literature on social circuses was searched, no criterion for year of publication was used. Synthesis No articles on the social circus as a health intervention were found. One study on the use of the circus as an intervention in schools was identified. It demonstrated an increase in self-esteem in the children who took part. One study on the use of the circus in a First Nations community was found; it contained nonspecific, qualitative findings. The other articles identified were merely descriptions of social circuses. One website was identified on the use of the social circus to help youth who had been treated in a hospital setting for major psychiatric disorders to re-enter the community. The team in the pediatric psychiatry department at Centre Hospitalier Universitaire Sainte-Justine, the children’s hospital in Montreal, Que, was contacted; they were leading this project, called Espace Transition. The unpublished preliminary findings of its pilot project demonstrate substantial improvements in overall patient

Sur la plurifonctionnalité du discours direct

Directory of Open Access Journals (Sweden)

Cigada Sara

2012-07-01

Full Text Available La comparaison entre les résultats de nombreux travaux sur le dialogue dans le texte littéraire, sur l’attestation linguistique de la subjectivité, sur la fonction argumentative des émotions dans le discours et sur les effets de polyphonie, suggère que la structure sémiotique et linguistique du discours direct (DD se trouve au croisement stratégique de plusieurs axes de la construction discursive. Nous étudions donc l’insertion du DD dans le discours (cf. Rosier 2008: Le discours rapporté en français; Kerbrat 2005: Le Discours en interaction et Id. 2008: Le Dialogue comme objet d’analyse linguistique; Maingueneau 2010: Manuel de linguistique pour le texte littéraire en tant que phénomène de rupture sémiotique (Genette 1972: Figures III et Id. 1983: Nouveau discours du récit, dans ses fonctions discursives plurielles, tantôt émotives (Tannen 1989: Talking Voices; Plantin-Traverso-Vosghanian 2008: Parcours des émotions en interaction, tantôt argumentatives (Doury 2001: La Fonction argumentative des échanges rapportés; Stati 1990: Le transphrastique. Du point de vue méthodologique, nous nous proposons de revisiter empiriquement, par l'étude de corpus, les traits linguistiques structuraux qui caractérisent l’insertion du DD dans un récit à l'écrit, en les comparant systématiquement aux traits de l’insertion du DD dans un récit à l'oral. Une analyse parallèle est possible en ce qui concerne les fonctions discursives, que le DD typiquement déroule dans les récits. Les fonctions du DD décrites à partir de l'étude des corpus sont plurielles: on reconnaît des fonctions fortement argumentatives d'autres plus typiquement narratives, tandis que d'autres encore amalgament les deux fonctions. Le « contrat de littéralité », qui selon Genette ne porterait jamais que sur la teneur du discours, doit donc être fortement nuancé selon les contextes, tandis que l'effet de sens le plus directement lié à la

Tuberculose du col utérin simulant un cancer du col utérin : à propos ...

African Journals Online (AJOL)

Tuberculose du col utérin simulant un cancer du col utérin : à propos d'un cas, au Centre Hospitalier Universitaire Souro Sanou de Bobo-Dioulasso, Burkina Faso. A. Dembélé, V. Konségré, E. Birba, D.A. Somé, H. Zamané, A.S. Ouédraogo, S. Kiemtoré, S. Ouattara, A. Lamien-Sanou, M. Bambara, B. Bonané/Thiéba ...

Effects of /sup 60/Co gamma radiation damage and heat treatment on the electro-mechanical properties of some related lithium alumino-borosilicate glasses

Energy Technology Data Exchange (ETDEWEB)

Abou Sekkina, M.M.; Gohar, I.A.; Megahed, A.A. (Al-Azhar Univ., Tanta (Egypt). Faculty of Science; Cairo Univ., El Mansura (Egypt). Faculty of Science)

1985-01-01

Various samples of pure lithium alumino-borosilicate glasses have been prepared and annealed. Data have been taken on the temperature dependence of DC electrical conductivity and the activation energy for conduction was evaluated in each case. Vickers hardness data have also been obtained as a function of tempering temperature and time for all glass compositions. Co-ordinated explanations of the DC conductivity and Vickers hardness induced by ionizing radiation are put forward and the activation energy for the process of carrier liberation are evaluated for the first time.

Intensification du recours à l'irrigation intermittente en riziculture afin ...

International Development Research Centre (IDRC) Digital Library (Canada)

Un nouveau projet de recherche vise à contribuer à la lutte contre le paludisme dans un bassin versant du nord du Pérou. Sur la côte du nord du Pérou, qui est fort aride, le paludisme est répandu en raison de l'irrigation abondante que nécessitent les rizières. La riziculture pratiquée dans cette région représente 60 % de la ...

Politique de gestion de l'habitat du poisson du Ministère des pêches et des océans

National Research Council Canada - National Science Library

1986-01-01

Le present document enonce la politique, les objectifs et les strategies du Ministere des Peches et des Oceans pour la gestion de l'habitat du poisson dont dependent les peches canadiennes en eaux douces et marines...

La géopolitique au risque du tourisme. 

Directory of Open Access Journals (Sweden)

Maie Gérardot

2008-06-01

Full Text Available La géopolitique du tourisme est dans l’air du temps. En témoigne la sortie, fin 2007, d’un numéro de la revue Hérodote consacré à cette question (recensé sur EspacesTemps.net — numéro auquel Jean-Michel Hoerner a d’ailleurs participé avec deux articles 1 , dont on retrouve le contenu dans son ouvrage Géopolitique du tourisme . Jean-Michel Hoerner, professeur de géopolitique et de tourisme, poursuit dans Géopolitique du tourisme , un travail de « reconnaissance ...

Magic turtle dans le canton du Jura: concept marketing

OpenAIRE

Hauser, Magali; Perruchoud-Massy, Marie-Françoise

2012-01-01

Depuis juin 2009, Saint-Ursanne/Clos du Doubs est une région pilote du Projet Enjoy Switzerland/ASM ayant pour but d’intervenir sur le développement et la sensibilisation du tourisme dans la région. En parallèle, la Maison du Tourisme, entreprise proposant principalement des offres touristiques dans la région, a ouvert ses portes l’année dernière. Ces deux entités ont travaillé ensemble afin de développer une nouvelle offre touristique intitulée « Magic turtle ». Le Magic turtle, pensé par de...

L’Harmonie du monde

Directory of Open Access Journals (Sweden)

Martine Clouzot

2003-11-01

Full Text Available La Bourgogne est particulièrement bien présente et représentée dans l’exposition sur la musique et ses représentations au Moyen Âge organisée par Isabelle Marchesin (université de Poitiers, Christine Laloue (conservatrice du Patrimoine au Musée et Martine Clouzot (université de Bourgogne, au Musée de la Musique à Paris du 26 mars au 27 juin 2004. En Côte-d’Or, à Dijon, la Bibliothèque municipale a donné son accord officiel pour le prêt de la Bible d’Etienne Harding, les Moralia in Job et u...

Fixation of Radioactive Waste in Glass. Part II. The Experimental Evaluation of Phosphate and Borosilicate Glasses; Fixation des Dechets Radioactifs dans le Verre, Deuxieme Partie: Evaluation Experimentale des Verres au Phosphate et au Borosilicate; 0424 0418 041a 0421 0410 0426 0418 042f 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 042b 0425 041e 0422 0425 041e 0414 041e 0412 0412 0421 0422 0415 041a 041b 0415 . 0427 0410 0421 0422 042c Ii. 042d 041a 0421 041f 0415 0420 0418 041c 0415 041d 0422 0410 041b 042c 041d 0410 042f 041e 0426 0415 041d 041a 0410 041a 0410 0427 0415 0421 0422 0412 0424 041e 0421 0424 0410 0422 041d 042b 0425 0418 0411 041e 0420 041e 0421 0418 041b 0418 041a 0410 0422 041d 042b 0425 0421 0422 0415 041a 041e 041b ; Fijacion de Desechos Radiactivos en Vidrio, Parte II: Evaluacion Experimental de los Vidrios al Fosfato y al Borosilicato

Energy Technology Data Exchange (ETDEWEB)

Elliot, M. N.; Grover, J. R.; Hardwick, W. H. [Atomic Energy Research Establishment, Harwell (United Kingdom)

1963-02-15

A glass suitable for long-term storage of fission-product wastes must be chosen firstly with regard to the method of storage, and secondly with regard to reliability of manufacture in a highly radioactive plant. The factors that are relevant to storage include leach resistance, thermal and radiation stability and die percentage of waste that can be incorporated, while the physical and chemical nature of glass-forming additives together with the melting point and viscosity of the glass relate to the manufacturing process. The relative importance of these factors is discussed. Experimental studies of the borosilicate glasses that have been chosen for pilot-plant work are described, including the effect of radiation doses of up to 10{sup 12}rad on their physical and chemical properties. Glasses of other kinds have also been examined and their potential value as storage media is compared with the borosilicate glasses. (author) [French] Un verre convenant au.stockage de longue duree des dechets de produits de fission doitetre choisi: premierement, en fonction de la methode de stockage et deuxiemement, eu egard a la securite des operations de traitement dans une usine de haute activite. En ce qui concerne le stockage, les facteurs importants sont la resistance a la corrosion, la stabilite thermique, la stabilite vis a-vis des rayonnements et le pourcentage de dechets pouvant etre incorpores. Au point de vue de la securite des manutentions, il faut tenir compte de la nature physique et chimique des elements intervenant dans la composition du verre, du point de fusion et de la viscosite du verre. Les auteurs examinent l'importance relative de ces facteurs. Ils decrivent les etudes experimentales faites sur les verres au borosilicate choisis pour l'usine pilote, de meme que l'influence des rayonnements sur leurs proprietes chimiques et physiques pour des doses allant jusqu'a 10{sup 12} rad. Ils ont etudie d'autres especes de verre et examine la possibilite de les employer

Phase evolution and dielectric properties of MgTi2O5 ceramic sintered with lithium borosilicate glass

International Nuclear Information System (INIS)

Shin, Hyunho; Shin, Hee-Kyun; Jung, Hyun Suk; Cho, Seo-Yong; Hong, Kug Sun

2005-01-01

Phase evolution, densification, and dielectric properties of MgTi 2 O 5 dielectric ceramic, sintered with lithium borosilicate (LBS) glass, were studied. Reaction between LBS glass and MgTi 2 O 5 was significant in forming secondary phases such as TiO 2 and (Mg,Ti) 2 (BO 3 )O. The glass addition was not necessarily deleterious to the dielectric properties due to the formation of TiO 2 : permittivity increased and temperature coefficient of resonance frequency could be tuned to zero with the addition of LBS glass, although the inevitable glass-induced decrease of quality factor was not retarded by the formation of TiO 2 . The sintered specimen with 10 wt% LBS fired at 950 deg. C for 2 h showed permittivity of 19.3, quality factor of 6800 GHz, and τ f of -16 ppm/ deg. C

Répercussions de la chute du mur de Berlin sur des conflits nationalistes : Pays Basque et Irlande du Nord

Directory of Open Access Journals (Sweden)

Pascal Pragnère

2012-11-01

Full Text Available La chute du mur de Berlin et l’effondrement des régimes communistes eurent pour effet de discréditer et affaiblir de nombreux mouvements révolutionnaires, et de provoquer l’émergence ou la résurgence de mouvements nationalistes.En 1989-90, deux conflits violents faisaient rage au cœur de l’Europe occidentale démocratique, en Irlande du Nord et au Pays Basque.Dans ces deux territoires, des nationalistes, dont certains étaient des radicaux animés par des revendications nationalistes et révolutionnaires s’opposèrent à des états démocratiques par l’utilisation de la violence. Un processus de paix se développa à partir de 1998 en Irlande du Nord ; celui du Pays Basque est toujours dans l’impasse.Il semble au premier abord que ces conflits continuèrent sans bouleversement majeur dans la période qui suivit la chute du mur.Cet article examine les revendications des nationalistes en Irlande du Nord et au Pays Basque pour tenter de dévoiler dans quelle mesure ils furent affectés par ce choc historique.Une perspective comparative permet de comprendre que ces mouvements furent influencés différemment en fonction des contextes locaux. Certains acteurs politiques restèrent volontairement imperméables, alors que d’autres furent davantage affectés par le débat idéologique.

Analyse économique de la production artisanale du chakpalo au ...

African Journals Online (AJOL)

SARAH

31 mars 2015 ... maltage de la céréale (sorgho, maïs et/ou le mélange du sorgho et du maïs), le brasage du malt .... trempage, la germination et le séchage. Les grains de sorgho sont vannés, triés et lavés à grande .... cours du chauffage afin d'éviter la calcination et l'incrustation des particules au fond de la marmite ; des.

Color centers of a borosilicate glass induced by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray

Science.gov (United States)

Du, Jishi; Wu, Jiehua; Zhao, Lili; Song, Lixin

2013-05-01

Optical absorption spectra, electron paramagnetic resonance (EPR) spectra, Raman spectra of a borosilicate glass after irradiation by 10 MeV proton, 1.85 MeV electron and 60Co-γ ray were studied. The process of irradiation inducing color centers in the glass was discussed. The band gap of the glass before and after 60Co-γ ray irradiation was studied using Mott and Davis's theory, and it was found that calculated change of the band gap introduced a paradox, because Mott and Davis's theory on the band gap cannot be adopted in the study on the irradiated glass.

Utilization of Cs137 to generate a radiation barrier for weapons grade plutonium immobilized in borosilicate glass canisters. Revision 1

International Nuclear Information System (INIS)

Jardine, L.J.; Armantrout, G.A.; Collins, L.F.

1995-01-01

One of the ways recommended by a recent National Academy of Sciences study to dispose of excess weapons-grade plutonium is to encapsulate the plutonium in a glass in combination with high-level radioactive wastes (HLW) to generate an intense radiation dose rate field. The objective is to render the plutonium as difficult to access as the plutonium contained in existing US commercial spent light-water reactor (LWR) fuel until it can be disposed of in a permanent geological repository. A radiation dose rate from a sealed canister of 1,000 rem/h (10 Sv/h) at 1 meter for at least 30 years after fabrication was assumed in this paper to be a radiation dose comparable to spent LWR fuel. This can be achieved by encapsulating the plutonium in a borosilicate glass with an adequate amount of a single fission product in the HLWS, namely radioactive Cs 137 . One hundred thousand curies of Cs 137 will generate a dose rate of 1,000 rem/h (10 Sv/h) at 1 meter for at least 30 years when imbedded into canisters of the size proposed for the Savannah River Site's vitrified high-level wastes. The United States has a current inventory of 54 MCi of CS 137 that has been separated from defense HLWs and is in sealed capsules. This single curie inventory is sufficient to spike 50 metric tons of excess weapons-grade plutonium if plutonium can be loaded at 5.5 wt% in glass, or 540 canisters. Additional CS 137 inventories exist in the United States' HLWs from past reprocessing operations, should additional curies be required. Using only one fission product, CS 137 , rather than the multiple chemical elements and compounds in HLWs to generate a high radiation dose rate from a glass canister greatly simplifies the processing engineering retirement for encapsulating plutonium in a borosilicate glass

Strategie de repeuplement du mollusque gasteropode Concholepas concholepas (B) au sud du Chili

OpenAIRE

Varelasantibanez, C

1992-01-01

Une stratégie de repeuplement du "loco" Concholepas concholepas (B) est développée dans le sud du Chili à partir de résultats obtenus au laboratoire sur la reproduction et la croissance de ce mollusque. Les reproducteurs sont conservés au laboratoire pendant toute l'année et l'émission de capsules ovigères peut être provoquée au cours de toute cette période. Les capsules sont ensuite transférées dans le milieu naturel où a lieu l'éclosion. Par ailleurs, des juvéniles recrutés dans le milie...

Influence du temps de conservation du sang sur l'hémogramme réalisé avec le Vet-ABC chez le chien et le chat

OpenAIRE

Caillard, Agnès

2002-01-01

L'utilisation du Vet abc, automate d'hématologie de type «coulter » a permis d'étudier les modifications engendrées par la conservation du sang pendant 24 heures à température ambiante, sur les paramètres et constituants de l'hémogramme du chien et du chat. L'évaluation de l'effet de la conservation du sang sur l'IDR et sur les courbes de distribution cellulaire, constitue l'originalité de ce travail. Les évolutions les plus notables ont été les suivantes : - un VGM qui augmente en moyenne de...

Effect of composition and temperature on viscosity and electrical conductivity of borosilicate glasses for Hanford nuclear waste immobilization

International Nuclear Information System (INIS)

Hrma, P.; Piepel, G.F.; Smith, D.E.; Redgate, P.E.; Schweiger, M.J.

1993-04-01

Viscosity and electrical conductivity of 79 simulated borosilicate glasses in the expected range of compositions to be produced in the Hanford Waste Vitrification Plant were measured within the temperature span from 950 to 1250 degree C. The nine major oxide components were SiO 2 , B 2 O 3 , Li 2 O, Na 2 O, CaO, MgO, Fe 2 O 3 , Al 2 O 3 , and ZrO 2 . The test compositions were generated statistically. The data were fitted by Fulcher and Arrhenius equations with temperature coefficients being multilinear functions of the mass fractions of the oxide components. Mixture models were also developed for the natural logarithm of viscosity and that of electrical conductivity at 1150 degree C. Least squares regression was used to obtain component coefficients for all the models

La microflore des sols du vignoble de Touraine

Directory of Open Access Journals (Sweden)

Claude Cuinier

1975-12-01

Full Text Available L'étude microbiologique des sols du vignoble porte sur trois années. Les déterminations quantitatives des bactéries, champignons, actinomycètes et des groupes fonctionnels des cycles de l'azote, du carbone et du soufre sont effectuées au cours de trois périodes du cycle végétatif de la vigne. Des variations saisonnières et annuelles sont observées. La microflore des sols viticoles est comparée à celle d'autres sols. Elle est au moins aussi riche et se distingue par son caractère plus aérobie. De grands écarts dans la composition microbiologique sont apparus entre des sols viticoles différant par leurs caractéristiques physiques et chimiques.

GRANDE VENTE DE NOEL - MAGASIN DU MONDE MEYRIN - French version only

CERN Multimedia

Groupe Magasin du Monde Meyrin

2002-01-01

Mercredi 4 décembre de 10h. à 14h.30 Bâtiment principal, devant le restaurant no1 Vous y trouverez des produits alimentaires tels que miel, café, chocolat, sucre, quinoa, épices, etc, bref un riche assortiment des produits du commerce équitable porteurs du label Max Havelaar garantissant un meilleur revenu aux producteurs du Tiers Monde. Egalement à votre disposition des produits de l'artisanat des quatre coins du monde et des idées de cadeaux pour Noël. Groupe Magasin du Monde Meyrin

La violence dans les services sociaux: situation dans les services d'aide contrainte du canton du Jura

OpenAIRE

Durand, Loriane; Favre, Eliane

2017-01-01

Mon Travail de Bachelor a pour but premier de prendre connaissance de la situation de la violence dans les services d’aide contrainte du canton du Jura. La violence est-elle une réalité ? De quels types de violence s’agit-il ? Pourquoi cette violence, quelles en sont les raisons ? Cette violence augmente-t-elle le stress dans la profession d’assistant social ?

Local structure near actinides and nucleating elements in borosilicate glass for nuclear industry: Results of X-ray absorption spectroscopy

International Nuclear Information System (INIS)

Petit-Maire, D.

1988-01-01

Possibilities and limits of X-ray absorption spectroscopy for cation site description in silicate glasses and possible applications for complex glasses, like glass for fission product containment, are examined. In borosilicate glasses two types of sites are evidenced for actinides at the valence 4: Coordinance 6 sites with a narrow radial distribution for the distance An-0; higher coordination (7, 8 or more) with a wider and asymmetrical radial distribution. Proportion of low coordinance sites increases when cation size decreases (Th > Np). U and Np VI and V are characterized as actinyles with a chain 0-An-0 practically linear, coordinance in a plane perpendicular to this complex is probably 5. X-ray absorption spectroscopy allows an accurate description of actinide sites in fission product glasses [fr

Effets de la microdose sur la production du niébé, du mil et du ...

African Journals Online (AJOL)

respectivement pour le sorgho, le mil et le niébé comparativement au témoin. La microdose a été .... Les prix utilisés sont celui du marché local au moment des semis pour les engrais soit 17500 FCFA pour NPK et ..... Projet « Transfert de la.

Incidence du cancer au Canada : tendances et projections (1983-2032

Directory of Open Access Journals (Sweden)

Lin Xie

2015-01-01

Full Text Available Dans cette monographie, nous présentons, pour 1983 à 2032, un historique et des projections du nombre de nouveaux cas et des taux d'incidence du cancer pour le Canada, à l'exception des cancers de la peau autres que le mélanome (c.-à -d. les carcinomes basocellulaire et spinocellulaire. Ces renseignements visent à faciliter la planification stratégique et l'affectation de ressources et d'infrastructures pour assurer la prestation future de soins de santé et de mesures de lutte contre le cancer. Évolution projetée des taux d'incidence de cancer : De 2003-2007 à 2028-2032, les taux d'incidence normalisés selon l'âge (TINA pour l'ensemble des cancers devraient diminuer de 5 % pour les Canadiens, passant de 464,8 à 443,2 pour 100 000 habitants, et augmenter de 4 % pour les Canadiennes, passant de 358,3 à 371,0 pour 100 000 habitants. La diminution globale des taux de cancer chez les hommes sera le résultat de la baisse des taux de cancer du poumon chez les hommes de 65 ans et plus et des taux de cancer de la prostate chez les hommes de 75 ans et plus. L'augmentation globale des taux de cancer chez les femmes correspond à la hausse prévue des taux de cancer du poumon chez les femmes de 65 ans et plus. Elle représente également la hausse prévue des cas de cancer de l'utérus, de la thyroïde, du sein (chez les femmes de moins de 45 ans, du rein et du pancréas ainsi que des cas de leucémie et de mélanome. Parmi les changements les plus importants dans les TINA projetés sur un horizon de 25 ans, mentionnons une augmentation du nombre de cas de cancer de la thyroïde (55 % chez les hommes et 65 % chez les femmes et de cancer du foie chez les hommes (43 %, et une diminution du nombre de cas de cancer du larynx (47 % chez les hommes et 59 % chez les femmes, de cancer du poumon chez les hommes (34 % et de cancer de l'estomac (30 % chez les hommes et 24 % chez les femmes. Le taux d'incidence du cancer du poumon chez les femmes

98 Etude Comparative du Systeme Phonematique et Tonal des ...

African Journals Online (AJOL)

98. Etude Comparative du Systeme Phonematique et Tonal des. Deux Parlers: Le Yoruba du Nigeria et L'itsa Parle en. Republique du Benin. Ajani Akinwumi Lateef et Ayuba G. Ajibabi http://dx.doi./org/10.4314/ujah.v18i3.5. Résume. En ce début de l'époque ou la mondialisation et la coexistence des peuples dans le ...

Carcinome du tube collecteur de Bellini: une nouvelle observation ...

African Journals Online (AJOL)

Le carcinome du tube collecteur de Bellini est un type très rare des carcinomes à cellules rénales (CCR), sa fréquence est inférieure à 1%. Il dérive de la partie distale du néphron, plus précisément du tube collecteur. Ses aspects morphologiques sont extrêmement variables, rendant son diagnostic difficile. Nous rapportons ...

Le vide univers du tout et du rien

CERN Document Server

Diner, Simon

1997-01-01

Pourquoi l'Univers plutôt que le vide ? Le temps et l'espace existent-ils en l'absence de l'Univers ? Que reste-t-il quand tout est enlevé ? Pourquoi quelque chose plutôt que rien ? Depuis des siècles, ces interrogations mobilisent philosophes et physiciens. Mais aujourd'hui, le vide n'est pas le rien. Il serait même l'acteur central de l'histoire de la matière et de l'Univers, le partenaire privilégié de la physique. Vide et matière ne sont plus deux manifestations séparées de la nature, mais deux aspects d'une même réalité. Le vide est l'état de base dont la matière émerge, sans couper son cordon ombilical Le vide comme Univers du rien cède la place au vide comme Univers du tout. Que le vide puisse être conçu par les physiciens comme réservoir potentiel d'univers, voici qui ne devrait laisser personne indifférent. Ce livre ouvre un débat et nous convie à une réflexion surprenante.

Ėtude sur l’alimentation du poulet de chaire à base du maïs Zenata et Ain kebira

OpenAIRE

KENZI, MOHAMMED ZAKARYA; WAHAJ, MOHAMMED

2016-01-01

Résume L’aliment représente 70% du cout de production dans l’élevage de poulet de chair, il est donc important d’accorder une attention particulière à ce paramètre. Ce dernier est le premier poste intervenant dans le prix de revient du poulet de chair. La supplémentation de l’aliment du poulet en 2 5% de maïs durant le démarrage et croissance permet aussi de réduire le cout d’élevage et d’améliorer le poids a l’abattage. Study chair of chicken feed made of corn Summ...

les cahiers du cread: About this journal

African Journals Online (AJOL)

les cahiers du cread: About this journal. Journal Home > les cahiers du cread: About this journal. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. People. » Contact. Policies.

L’Association du personnel, le TREF, le Comité des Finances et le Conseil du CERN

CERN Multimedia

Staff Association

2016-01-01

L’Association du personnel, forte de son approche participative et consensuelle, recherche toujours le meilleur accord possible pour l’Organisation et son personnel. Pour ce faire, discussions et concertation avec la Direction, travail d’explication et de persuasion au TREF et ailleurs auprès des délégués des États membres sont nos principaux atouts. TREF (Tripartite Employment Conditions Forum), un Forum d’échanges, de discussions « L’objectif du Forum est d’améliorer le processus de prise de décision  en donnant aux personnes concernées la possibilité et le temps de comprendre pleinement la position de tous les participants. » (CERN/RTG/8) Le Forum tripartite sur les conditions d’emploi (TREF), créé par le Conseil du CERN en juin 1994, est composé de r...

Electrical characterization of strontium titanate borosilicate glass ceramics system with bismuth oxide addition using impedance spectroscopy

International Nuclear Information System (INIS)

Thakur, O.P.; Kumar, Devendra; Parkash, Om; Pandey, Lakshman

2003-01-01

The ac electrical data, measured in the frequency range 0.1 kHz-1 MHz, were used to study the electrical response of strontium titanate borosilicate glass ceramic system with bismuth oxide addition. Complex plane plots from these electrical data for various glass ceramic samples reveal contributions from simultaneously operating polarization mechanisms to overall dielectric behavior. The complex modulus (M * ) representation of electrical data for various glass ceramic samples were found to be more informative. Equivalent circuit models, which represent the electrical behavior of glass ceramic samples, were determined using complex non-linear least square (CNLS) fitting. An attempt has been made to understand the dielectric behavior of various glass ceramics in terms of contributions arising from different polarization processes occurring at glassy matrix, crystalline phases, glass to crystal interface region and blocking electrodes. Glass ceramics containing SrTiO 3 and TiO 2 (rutile) phases show thermally stable dielectric behavior

Spécificités du sous-titrage pour enfants malentendants

OpenAIRE

Comitre-Narvaez, Isabel

2016-01-01

Ce travail aborde la spécificité multisémiotique du texte audiovisuel qui est à l’origine de nombreux défis que le traducteur audiovisuel doit relever. Il explore les rapports intersémiotiques qui s’établissent entre le code verbal et le code visuel et se concentre sur les particularités du sous-titrage pour sourds et malentendants dans la “compensation” du déficit auditif, essentiellement son rapport spécifique à l’image. À cet égard, Gottlieb signale que le succès du sous-titrage dépend du ...

Incorporation du coprah et des cuticules de cacao et d'arachide ...

African Journals Online (AJOL)

Incorporation du coprah et des cuticules de cacao et d'arachide dans l'aliment du ( tilapia du nil( ( Oreohromis niloticus , linné, 1758) eleve en etang : Effet sur la croissance et la composition biochimique.

Histoire et sociétés du Vietnam classique

OpenAIRE

Papin, Philippe

2012-01-01

Programme de l’année 2008-2009 : I. Histoire rurale de la propriété foncière au Vietnam du XVIe au XVIIIe siècle. — II. Étude des sources de l’histoire villageoise du bassin du fleuve Rouge à l’époque moderne.

Directeur, Gestion du risque et audit interne | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

Résumé des fonctions En qualité de dirigeant principal de l'audit (DPA), ... président du Centre et au président du Comité des finances et de l'audit une assurance et des ... Il fournit des services de gestion du risque organisationnel et d'autres ...

La mesure du danger

CERN Document Server

Manceron, Vanessa; Revet, Sandrine

2014-01-01

La mesure du danger permet d’explorer des dangers de nature aussi diverse que la délinquance, la pollution, l’écueil maritime, la maladie ou l’attaque sorcellaire, l’extinction d’espèces animales ou végétales, voire de la Planète tout entière. Au croisement de la sociologie, de l’anthropologie et de l’histoire, les différents articles analysent les pratiques concrètes de mesure pour tenter de comprendre ce qui se produit au cours de l’opération d’évaluation du danger sans préjuger de la nature de celui-ci. L’anthropologie a contribué à la réflexion sur l’infortune en s’intéressant aux temporalités de l’après : maladies, catastrophes, pandémies, etc. et en cherchant à rendre compte de l’expérience des victimes, de leur vie ordinaire bouleversée, de la recomposition du quotidien. Elle s’intéresse aussi aux autres types de mesures, les savoirs incorporés, qui reposent sur l’odorat, la vue ou le toucher et ceux qui ressortent d’une épistémologie « non ...

Proudhon, science ou métaphysique du travail

OpenAIRE

Lecerf , Eric

2008-01-01

La philosophie de Proudhon, même si elle trouve son concept essentiel dans la justice, est intégralement une philosophie du travail, non pas que le travail en constitue l'objet unique, mais car c'est en lui que les tensions du réel sont concrètement identifiables. C'est dans sa critique que l'agir humain se donne comme émancipation et/ou aliénation, autrement dit que la dialectique acquiert toute sa justification. La philosophie du travail de Proudhon donnera lieu à deux lectures opposées : c...

Une étude du pluralisme architectural: l'indicateur des métamorphoses du quartier Mariscal Sucre à Quito

Directory of Open Access Journals (Sweden)

Marie S. BOCK

1993-06-01

Full Text Available L’étude de la carte du pluralisme architectural du quartier Mariscal Sucre à Quito, élaborée à partir d’une matrice de Bertin, permet de mettre en valeur une dichotomie chronologique et fonctionnelle et de dégager des profils architecturaux soulignant les différentes étapes de constitution et d’évolution de ce secteur.

Entrepreneur innovateur du troisième millénaire

OpenAIRE

Nathalie Mudard-Franssen

2000-01-01

A notre époque, charnière d'un nouveau siècle, il me semble pertinent de s'interroger sur la légitimité du rôle de l'entrepreneur innovateur du troisième millénaire. C'est pourquoi, à partir des débats au sein du D.E.S.S. « Entrepreneuriat et Redéploiement Industriel » de l'Université du Littoral Côte d'Opale de Dunkerque de l'année universitaire 1999-2000, j'ai recueilli 7 contributions et réalisé ce document de travail afin de présenter l'entrepreneur innovateur sous plusieurs angles. Ce do...

Progrès de la connaissance du Congo, du Rwanda et du Burundi de 1993 à 2008

Directory of Open Access Journals (Sweden)

Henri Nicolaï

2013-03-01

Full Text Available Cette chronique, la vingt et unième d’une série qui a commencé avec l’année 1949, couvre la période 1993-2008 et a pour objectif de faire le point sur les progrès réalisés sur la connaissance du Congo (République démocratique du Congo, du Rwanda et du Burundi, dans le domaine de la géographie mais aussi dans les domaines des sciences naturelles et des sciences humaines qui peuvent fournir des données utiles ou indispensables aux géographes. Chaque référence bibliographique, livre ou article, est accompagnée d’un bref commentaire qui en retient les éléments principaux et surtout les faits ou les idées qui intéressent particulièrement les géographes. L’article comporte onze chapitres dont les plus importants concernent le milieu naturel, la géographie de la santé, la démographie, l’histoire (y compris l’histoire récente, la vie sociale et économique des campagnes traditionnelles et modernes, le secteur informel, les aspects de la vie urbaine. Les événements dramatiques qui se sont produits dans ces territoires africains au cours des quinze dernières années ont rendu la recherche sur le terrain particulièrement difficile tant pour les chercheurs nationaux que pour les chercheurs étrangers, ce qui se traduit notamment par une part de plus en plus importante des recherches menées en milieu urbain.This paper, the 21st issue of an edition of books and paper reviews on the knowledge of three countries of former Belgian Africa (DR Congo, Rwanda, and Burundi, covers the period 1993-2008. A short text for each reference points out the facts or ideas that are useful for geographers. The paper is composed of eleven sections. The most important are coping with the natural environment, health geography, population geography, history (including recent events, social and economic life in traditional and modern rural areas, informal economy, and urban geography. During the last sixteen years, conditions for field

Case Report - Le syndrome de Cri du Chat : A propos d'une ...

African Journals Online (AJOL)

Le syndrome du Cri du Chat (Cri du Chat syndrome, CdCS) est une anomalie chromosomique résultant d'une délétion de taille variable de l'extrémité du bras court du chromosome 5 (5p), incluant une région critique située en p15.2. Il représente une des délétions chromosomiques les plus fréquentes, son incidence dans ...

Sud du Sahara | Page 9 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Un nouveau projet de recherche sur la prévention du VIH a conduit à la réalisation d'un essai national novateur de prévention du VIH au Botswana. Read more about Des résultats de recherche mènent à la réalisation d'essais de prévention du VIH dans l'ensemble du Botswana. Langue French. New research into HIV ...

Couzeix – Les Terres du Puy Dieu

OpenAIRE

Maniquet, Christophe

2013-01-01

Identifiant de l'opération archéologique : 122281 Date de l'opération : 2005 (EX) Dans le cadre du projet de construction d'un lotissement constitué de trois pavillons au lieu-dit « Les Terres du Puy Dieu », un diagnostic archéologique a été prescrit par le service régional de l'Archéologie. En effet, plusieurs sites archéologiques avaient été inventoriés à proximité immédiate de la zone d'intervention. On notera, en particulier, la découverte en 1982, près du Puy Dieu, au cours de travaux de...

The biokinetics of uranium migrating from embedded DU fragments

International Nuclear Information System (INIS)

Leggett, R.W.; Pellmar, T.C.

2003-01-01

Military uses of depleted uranium (DU) munitions have resulted in casualties with embedded DU fragments. Assessment of radiological or chemical health risks from these fragments requires a model relating urinary U to the rate of migration of U from the fragments, and its accumulation in systemic tissues. A detailed biokinetic model for U has been published by the International Commission on Radiological Protection (ICRP), but its applicability to U migrating from embedded DU fragments is uncertain. Recently, ) conducted a study at the Armed Forces Radiobiology Research Institute (AFRRI) on the redistribution and toxicology of U in rats with implanted DU pellets, simulating embedded fragments. This paper compares the biokinetic data from that study with the behavior of commonly studied forms of U in rats (e.g., intravenously injected U nitrate). The comparisons indicate that the biokinetics of U migrating from embedded DU is similar to that of commonly studied forms of U with regard to long-term accumulation in kidneys, bone, and liver. The results provide limited support for the application of the ICRP's model to persons with embedded DU fragments. Additional information is needed with regard to the short-term behavior of migrating U and its accumulation in lymph nodes, brain, testicles, and other infrequently studied U repositories

1er mars 2017 - Signature du livre d'or, visite du tunnel du LHC au Point 5 et de la caverne expériementale de CMS par le Secrétaire d’Etat français aux Affaires européennes auprès du ministre des Affaires étrangères et du Développement international H. Désir.

CERN Multimedia

Bennett, Sophia Elizabeth

2017-01-01

Entourent le Secrétaire d'Etat pendant la signature du livre d'or: Le Préfet de l’Ain A. Cochet; le Directeur des accélérateurs et de la technologie F. Bordry; Ambassadeur, Représentant permanent de la France auprès de l’Office des Nations Unies à Genève et des Organisations internationales en Suisse E. Laurin; la Directrice générale du CERN F. Gianotti et la Directrice des relations internationales C. Warakaulle. Sont également présents: H. Bertrand, Maire de Saint-Genis-Pouilly; C. Bouvier, Maire de Cessy; G. Rousseau, Secrétaire Général de la sous-préfecture de Gex; Y. Mecibah, Directrice de Cabinet du Maire de Saint-Genis-Pouilly; F. Croquette, Ambassadeur pour les droits de l’homme, chargé de la dimension internationale de la Shoah, des spoliations et du devoir de mémoire; S. Bonbayl, Conseillère technique, Cabinet du Secrétaire d’Etat chargé des Affaires Européennes au MAEDI; F. Cormon-Veyssière, Sous-Directrice des droits de l’Homme et des Affaires humanitaires au MAEDI...

Commis, artisans, ouvriers. Les métamorphoses du salariat dans l’Égypte du XIXe siècle

Directory of Open Access Journals (Sweden)

Pascale Ghazaleh

2012-01-01

Full Text Available Cet article se propose d’analyser l’évolution du travail salarié en Égypte pendant la première moitié du XIXe siècle à la lumière des modifications apportées au système des charges vénales, qui permet aux sujets du sultan d’accéder au statut de ses serviteurs en achetant le droit de toucher une rémunération. Les réformes juridiques, militaires, économiques et administratives qu’institue Muhammad ‘Alî (r. 1805-1848 en Égypte vont ériger les instances de l’État naissant en source de rémunération et point de référence primaire des détenteurs de charges. Pendant la période 1840-1860, les recrutements de fonctionnaires et de travailleurs connaîtront un repli ; et, lorsque la question du travail salarié est abordée à part entière dans le discours public des années 1880, c’est sous son versant politique, comme métaphore de la tutelle coloniale.

Chemical durability of alkali-borosilicate glasses studied by analytical SEM, IBA, isotopic-tracing and SIMS

Science.gov (United States)

Trocellier, P.; Djanarthany, S.; Chêne, J.; Haddi, A.; Brass, A. M.; Poissonnet, S.; Farges, F.

2005-10-01

Simple and complex alkali-borosilicate glasses were submitted to aqueous corrosion at room temperature, 60 and 90 °C in solutions with pH ranging between 0 and 12. Analytical scanning electron microscopy (SEM), ion beam analysis (IBA) techniques, isotopic tracing and secondary ion mass-depth profiling (SIMS) have been used to investigate the variations of the surface composition of glass. In acidic medium, the glass surface is generally covered by a thick hydrated silica layer, mobile elements like Li, Na and B and transition elements (Fe, Zr, Mo, etc.) are strongly depleted. Near pH 7, relative enrichments of aluminium, iron and rare earths are shown together with strong Li, Na and B depletions. In basic medium, the glass surface exhibits relative enrichments of the major part of transition metals (from Cr to U) whereas mobile elements seem to be kept close to their nominal concentration level at the glass surface and Si is severely impoverished. Hydrogen incorporated at the glass surface after leaching is much more immobile in neutral and basic media than in acid medium.

Chemical durability of alkali-borosilicate glasses studied by analytical SEM, IBA, isotopic-tracing and SIMS

International Nuclear Information System (INIS)

Trocellier, P.; Djanarthany, S.; Chene, J.; Haddi, A.; Brass, A.M.; Poissonnet, S.; Farges, F.

2005-01-01

Simple and complex alkali-borosilicate glasses were submitted to aqueous corrosion at room temperature, 60 and 90 deg. C in solutions with pH ranging between 0 and 12. Analytical scanning electron microscopy (SEM), ion beam analysis (IBA) techniques, isotopic tracing and secondary ion mass-depth profiling (SIMS) have been used to investigate the variations of the surface composition of glass. In acidic medium, the glass surface is generally covered by a thick hydrated silica layer, mobile elements like Li, Na and B and transition elements (Fe, Zr, Mo, etc.) are strongly depleted. Near pH 7, relative enrichments of aluminium, iron and rare earths are shown together with strong Li, Na and B depletions. In basic medium, the glass surface exhibits relative enrichments of the major part of transition metals (from Cr to U) whereas mobile elements seem to be kept close to their nominal concentration level at the glass surface and Si is severely impoverished. Hydrogen incorporated at the glass surface after leaching is much more immobile in neutral and basic media than in acid medium

Impact socio professionnel de la libération chirurgicale du syndrome du canal carpien

Science.gov (United States)

Kraiem, Aouatef Mahfoudh; Hnia, Hajer; Bouzgarrou, Lamia; Henchi, Mohamed Adnène; Khalfallah, Taoufik

2016-01-01

L’objectif de notre travail était d’étudier les conséquences socioprofessionnelles d’une libération chirurgicale du SCC. Il s’agit d’une étude transversale portant sur les sujets opérés pour un SCC d’origine professionnelle ; recensés dans le Service de Médecine de Travail et de Pathologies Professionnelles au CHU Tahar Sfar de Mahdia en Tunisie sur une période de 8 ans allant du 1 Janvier 2006 au mois Décembre 2013. Le recueil des données s’est basé sur une fiche d’enquête, portant sur la description des caractéristiques socioprofessionnelles, médicales, et sur le devenir professionnel des participants. Pour étudier les contraintes psychosociales au travail, nous avons adopté le questionnaire de Karasek. La durée d’arrêt de travail après libération chirurgicale du SCC était significativement liée à l’existence d’autres troubles musculo-squelettiques autre que le SCC, la déclaration du SCC en maladie professionnelle et à l’ancienneté professionnelle des salariés. Quant au devenir professionnel des salariés opérés, 50,7% ont gardé le même poste, 15,3% ont bénéficié d’un aménagement de poste et 33,8% ont bénéficié d’un changement de poste dans la même entreprise. Le devenir professionnel de ces salariés était corrélé à leurs qualifications professionnelles et au type de l’atteinte sensitive et/ou motrice du nerf médian à l’EMG. Un certain nombre de facteurs non lésionnels déterminaient la durée de l’arrêt de travail, alors que le devenir professionnel des opérés pour SCC dépendait essentiellement de leurs qualifications professionnelles et des données de l’électromyogramme. Il est certain que des travaux beaucoup plus larges permettraient d’affiner encore ces résultats. PMID:27800089

Nouvelle initiative des chaires de recherche Canada-Afrique du Sud ...

International Development Research Centre (IDRC) Digital Library (Canada)

8 déc. 2016 ... Elles s'appuient sur le South African Research Chairs Initiative (SARChl), ainsi que sur le programme de chaires de recherche industrielle, dont le financement provient en partie du Conseil de recherches en sciences naturelles et en génie du Canada (CRSNG) et du Programme des chaires de recherche ...

1 Commande multivariable du moteur asynchrone triphasé à cage ...

African Journals Online (AJOL)

AKA BOKO

Correspondance, courriel : rabenarivo.michel@yahoo.fr. Résumé. La commande du moteur asynchrone triphasé à ... synthèse du système à l'aide du logiciel MATLAB. Mots-clés : commande, système multivariable, variation de ... of the system by MATLAB software. Keywords : control, MIMO system, frequency variation, ...

Card sorting, test d’oculométrie et test d’utilisabilité sur le site web du Service d’information scientifique du CERN

CERN Document Server

Marchand, Alizée; Schneider, René

Ce travail de Bachelor a pour objectif l’évaluation du site web du Service d’information scientifique du CERN. Cette évaluation est basée sur les méthodes utilisées en User Centered Design (UCD). Pour effectuer cette évaluation, nous avons sélectionné trois tests : un card sorting, un test d’oculométrie et un test d’utilisabilité. Selon la norme ISO 9241-11 :1998, l’utilisabilité se définit par « le degré selon lequel un produit peut être utilisé, par des utilisateurs identifiés, pour atteindre les buts définis avec efficacité, efficience et satisfaction, dans un contexte d’utilisation spécifié ». Les tests que nous avons réalisés nous ont permis d’identifier les problèmes d’utilisabilité du site du Service, en nous appuyant sur les caractéristiques d’utilisabilité définies dans cette norme. Pour ce faire, nous avons élaboré les tests en nous basant sur les pratiques utilisées par les spécialistes en UCD. Nous avons ensuite proposé à des employés du CERN, ...

Projet pilote sur la stimulation du commerce des services au Moyen ...

International Development Research Centre (IDRC) Digital Library (Canada)

Projet pilote sur la stimulation du commerce des services au Moyen-Orient et en Afrique du Nord. Si certaines régions en développement ont réussi à s'intégrer aux chaînes de production mondiales, la région du Moyen-Orient et de l'Afrique du Nord ne participe encore à l'économie mondiale que par des activités simples et ...

Processing and optical characterization of lead calcium titanate borosilicate glass doped with germanium

Science.gov (United States)

Gautam, C. R.; Das, Sangeeta; Gautam, S. S.; Madheshiya, Abhishek; Singh, Anod Kumar

2018-04-01

In this study, various compositions of lead calcium titanate borosilicate glass doped with a fixed amount of germanium were synthesized using the rapid melt quench technique. The amorphous nature of the synthesized glass was confirmed by X-ray diffraction and scanning electron microscopy analyses. The structural and optical properties were deduced using Raman, Fourier transform infrared (FTIR), and ultraviolet-visible (UV-Vis) spectroscopy. FTIR spectroscopy confirmed the presence of borate groups in triangular and tetrahedral coordination. Infrared and Raman analyses detected the vibrational bonds of Gesbnd Osbnd Ge, Bsbnd Osbnd Ge, Sisbnd Osbnd Ge, Sisbnd Osbnd Si, and Pbsbnd Osbnd Ge. The energy band gaps were evaluated for the prepared glass samples based on Tauc plots of the UV-Vis spectra. The calculated values of the optical band gap decreased from 2.91 to 2.85 eV as the PbO content increased from x = 0.0 to x = 0.7. Furthermore, the Urbach energy was studied based on the UV-Vis results to confirm the disordered structure of the glass. The calculated densities of the glass samples (1.5835 g/cm3 to 3.9184 g/cm3) increased as the concentration of PbO increased, whereas they decreased with the molar volume.

Immobilization of simulated high-level radioactive waste in borosilicate glass: Pilot scale demonstrations

International Nuclear Information System (INIS)

Ritter, J.A.; Hutson, N.D.; Zamecnik, J.R.; Carter, J.T.

1991-01-01

The Integrated DWPF Melter System (IDMS), operated by the Savannah River Laboratory, is a pilot scale facility used in support of the start-up and operation of the Department of Energy's Defense Waste Processing Facility. The IDMS has successfully demonstrated, on an engineering scale (one-fifth), that simulated high level radioactive waste (HLW) sludge can be chemically treated with formic acid to adjust both its chemical and physical properties, and then blended with simulated precipitate hydrolysis aqueous (PHA) product and borosilicate glass frit to produce a melter feed which can be processed into a durable glass product. The simulated sludge, PHA and frit were blended, based on a product composition program, to optimize the loading of the waste glass as well as to minimize those components which can cause melter processing and/or glass durability problems. During all the IDMS demonstrations completed thus far, the melter feed and the resulting glass that has been produced met all the required specifications, which is very encouraging to future DWPF operations. The IDMS operations also demonstrated that the volatile components of the melter feed (e.g., mercury, nitrogen and carbon, and, to a lesser extent, chlorine, fluorine and sulfur) did not adversely affect the melter performance or the glass product

Effect of various lead species on the leaching behavior of borosilicate waste glass

International Nuclear Information System (INIS)

Lehman, R.L.; Kuchinski, F.A.

1984-01-01

A borosilicate nuclear waste glass was static leached in pure water, silicate water, and brine solution. Three different forms of lead were included in specified corrosion cells to assess the extent to which various lead species alter the leaching behavior of the glass. Weight loss data indicated that Pb/sub m/ amd PbO greatly reduce the weight loss of glass when leached in pure water, and similar effects were noted in silicate and brine. Si concentrations, which were substantial in the glass-alone leachate, were reduced to below detection limits in all pure water cells containing a lead form. Lead concentration levels in the leachate were controlled by lead form solubility and appeared to be a significant factor in influencing apparent leaching behavior. Surface analysis revealed surface crystals, which probably formed when soluble lead in the leachate reacted with dissolved or activated silica at the glass surface. The net effect was to reduce the lease of some glass constituents to the leachate, although it was not clear whether the actual corrosion of the glass surface was reduced. Significantly different corrosion inhibiting effects were noted among lead metal and two forms of lead oxide. 9 refs., 7 figs., 3 tabs

Conversation sur les préoccupations scientifiques et les perspectives de recherche au sein du Laboratoire d'Anthropologie Visuelle et Sonore du Monde Contemporain

Directory of Open Access Journals (Sweden)

Jean Arlaud

2000-06-01

Full Text Available La présent conversation a été pensée comme l'opportunité de présenter le "Laboratoire d'Anthropologie Visuelle et Sonore du Monde Contemporain", de l'Université Paris 7 - Denis Diderot. Il a été crée en 1992 par monsieur le professeur Dr. Jean Arlaud, anthropologue et cinéaste, directeur auteur et réalisateur de plus de vingt filmes sur des sociétés de tous les continents, dans le même esprit que Jean Rouch, son directeur de doctorat. Ce laboratoire, qui regroupe actuellement 35 chercheurs statutaires et associés, développe des programmes de recherche en Asie Centrale (population Kalash, culture populaire et identité, Asie du Sud-Est ( danses masquées, musique, silat, Îles du Pacifique (Vanuatu, Etats Unis (population Cajun, Afrique (population nilotiques Nyangatom, populations Dogon et Bambara et Europe (anthropologie urbaine, anthropologie rurale, identité, migrations/changements. Ce dialogue, fruit de l'initiative du doctorant brésilien Luiz Eduardo Robinson Achutti, chercheur associé au laboratoire, présent la démarche scientifique et méthodologique du laboratoire. A travers les paroles du Dr. Jean Arlaud, du Dr.Pascal Dibie, de la Dra.Christine Louveau de la Guigneraye et Achutti, sont abordés les sujets et les préoccupations actuels de ces chercheurs, questions sur l'anthropologie de proximité, l'approche poétique, la pratique du travail avec les images et les sons, la ville comme lieu de recherche et les connections entre anthropologie et multimédia.

Un Genevois coopte a la tete du Front islamique du salut

CERN Multimedia

Merckling, N

2002-01-01

"Le Front islamique du salut (FIS), a nomme a la tete de ce parti fondamentaliste un resident genevois, Mourad Dhani, chois parmi trois candidats. Ce physicien algerien est arrive a Geneve il y a 14 ans pour travailler au CERN (1 page).

Polymorphisme de l'apolipoprotéine E dans la population du nord du Maroc: fréquence et influence sur les paramètres lipidiques

Science.gov (United States)

Benyahya, Fatiha; Barakat, Amina; Ghailani, Naima; Bennani, Mohcine

2013-01-01

Introduction L'objectif de ce travail est de déterminer les fréquences alléliques et génotypiques des sites polymorphes situés dans le gène de l'apolipoprotéine E (apo E) ainsi que leur impact sur les paramètres cliniques et lipidiques dans un échantillon de la population du nord du Maroc cliniquement diagnostiqué ADH. Méthodes Le génotype de l'apo E a été analysé par séquençage direct chez 46 patients cliniquement diagnostiqués ADH selon les critères standards. Résultats Les fréquences des allèles epsilon 3, epsilon 2 et epsilon 4 ont été respectivement 78.3%, 2.2% et 19.6%. La fréquence de l'allèle epsilon 4 est très élevée chez la population du nord du Maroc en comparaison avec les populations des autres régions marocaines. Elle est similaire à celle rapportée dans les pays de l'Europe du nord. Les taux du cholestérol total, du cholestérol LDL ainsi que la présence des xanthomes et les maladies cardiovasculaires ne différent pas entre les génotypes de l'apoE. En revanche, les résultats ont montré une influence de l'allèle epsilon4 sur le taux des triglycérides chez les sujets obèses. Conclusion Le génotype de l'apoE ne peut expliquer le phénotype clinique et biochimique présenté par des patients du Nord du Maroc cliniquement diagnostiqués ADH. PMID:24396563

CALCUL DU SPECTRE DE REFLEXION DU MULTICOUCHE Ni/C DANS LE DOMAINE DES RAYONS X

Directory of Open Access Journals (Sweden)

A MEDDOUR

2000-12-01

Full Text Available Le pouvoir réflecteur d’un dioptre quelconque dans le domaine des rayons X est trop faible, mais il est toujours possible de choisir des systèmes pouvant présenter un pic de réflexion d’intensité importante autour d’une incidence caractéristique du matériau. Ce dernier est un multicouche, composé de deux couches déposées en sandwich.                 Nous avons élaboré un programme qui permet de calculer la réflexion d’un tel matériau en suivant la méthode d’Abelès dans laquelle une couche mince est représentée par une matrice carrée contenant toutes les informations nécessaires pour le calcul de la réflexion. Ce programme tient compte aussi des rugosités aux interfaces du multicouche, vue leur importante influence sur l’intensité du pic apparaissant sur le spectre de réflexion.                 L’application du programme au multicouche Ni/C a montré  l’existence d’un pic centré autour de 31.32°. Son intensité est sensible au nombre de périodes dans le multicouche, aux épaisseurs des couches minces de Ni et de C et à la taille des rugosités des interfaces Ni/C et C/Ni.

Spectrographic determination of chlorine and fluorine; Dosage du chlore et du fluor par spectrographie d'emission en atmosphere inerte

Energy Technology Data Exchange (ETDEWEB)

Contamin, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-04-01

Experimental conditions have been investigated in order to obtain the highest sensitivity in spectrographic determination of chlorine and fluorine using the Fassel method of excitation in an inert atmosphere. The influence of the nature of the atmosphere, of the discharge conditions and of the matrix material has been investigated. The following results have been established: 1. chlorine determination is definitely possible: a working curve has been drawn between 10 {mu}g and 100 {mu}g, the detection limit being around 5 {mu}g; 2. fluorine determination is not satisfactory: the detection limit is still of the order of 80 {mu}g. The best operating conditions have been defined for both elements. (author) [French] Nous avons recherche quelles etaient les conditions permettant d'obtenir la meilleure sensibilite dans le dosage spectrographique du chlore et du fluor par la methode d'excitation en atmosphere inerte (methode de Fassel). Nous avons etudie l'influence de l'atmosphere gazeuse, des conditions de la decharge et du materiau de pastillage. Les points suivants ont ete etablis: 1. le dosage du chlore est possible: une courbe de dosage a ete tracee entre 10 {mu}g et 100 {mu}g et la limite de detection est de l'ordre de 5 {mu}g; 2. le dosage du fluor n'est pas satisfaisant: la limite de detection obtenue etant encore de l'ordre de 80 {mu}g. Les conditions operatoires ont ete precisees pour ces deux elements. (auteur)

Role of LPG as an energy substitute in Algeria; Role des G.P.L. comme energie de substitution en Algerie

Energy Technology Data Exchange (ETDEWEB)

Boukadoum, Abdelhamid; Houghlaouene, Samir

2010-09-15

Algeria is a leader country in LPG industry. The availability of resources and the upstream production development efforts have oriented the large energy choices in terms of domestic market need satisfaction. LPG (propane and butane) plays a massive role in the change towards clean energy (case of LPG versus gas) and towards more practical energy (i.e. the case of bulk propane versus the packed butane, or versus natural gas). [French] L'Algerie est un pays leader dans l'industrie des GPL. La disponibilite des ressources et les efforts de developpement de la production en amont ont oriente les grands choix energetiques en matiere de satisfaction des besoins du marche domestique. En effet, les GPL (propane et butane) jouent un role majeur dans la substitution vers les sources d'energie propres (cas du GPL/C par rapport aux essences) et vers des energies plus commodes (par exemple le cas du propane vrac par rapport au butane conditionne, voire par rapport au gaz naturel).

Le marché sociolinguistique contemporain du Maroc

NARCIS (Netherlands)

de Ruiter, A.C.J.; Ziamari, Karima

2014-01-01

Au Maroc, les langues sont l’objet des polémiques les plus passionnées. Ce livre s’inscrit ainsi dans la continuité du débat concernant les politiques linguistiques adoptées et met à jour les évolutions récentes du marché sociolinguistique après l’adoption de la nouvelle constitution, approuvée par

Complications du traitement traditionnel des fractures : aspects ...

African Journals Online (AJOL)

Tous les patients reçus avec des complications du traitement traditionnel des fractures ont été inclus dans ce travail. Le diagnostic des lésions était clinique et radiologique. Nous avions reçu 51 patients porteurs de complications suite à des traitements de médecine traditionnelle, soit 13,7% du total des patients hospitalisés ...

Le kyste hydatique du cordon spermatique: une localisation exceptionnelle

Science.gov (United States)

Hamdane, Mohamed Moncef; Bougrine, Fethi; Msakni, Issam; Dhaoui-Ghozzi, Amen; Bouziani, Ammar

2011-01-01

L’ hydatidose est une anthropo-zoonose due au développement chez l'homme de la forme larvaire du taenia Echinococcus granulosis. La plupart des kystes hydatiques se localisent dans le foie et les poumons. Le kyste hydatique du cordon spermatique est extrêmement rare avec seulement 4 cas rapportés dans la littérature. Les auteurs rapportent dans cet article un nouveau cas d'hydatidose du cordon spermatique. Il s'agissait d'un homme de 40 ans qui consultait pour des douleurs scrotales évoluant depuis huit mois. L'examen clinique a mis en évidence une tuméfaction mobile, inguino-scrotale, droite. L’échographie testiculaire a objectivé une hernie inguinale droite associée à deux kystes épididymaires bilatéraux. Le patient a été opéré pour cure de son hernie avec découverte en per-opératoire d'un kyste du cordon spermatique qui a été réséqué. L'examen anatomopathologique a conclu à une hydatidose du cordon spermatique. PMID:22384304

Impacts du bruit sur la santé, présentation du projet DEBATS (Discussion sur les Effets du Bruit des Aéronefs Touchant la Santé).

OpenAIRE

EVRARD, Anne-Sophie; KHATI, Inès; LAUMON, Bernard; CHAMPELOVIER, Patricia; LAMBERT, Jacques

2012-01-01

L’exposition au bruit des avions pourrait avoir des conséquences importantes pour la santé. Toutefois, celles-ci sont actuellement insuffisamment évaluées, tout du moins en France. La DGS en collaboration avec l’Acnusa a donc sollicité l’Ifsttar pour mettre en place un programme de recherche épidémiologique appelé DEBATS. L'objectif est de mieux connaître et mieux quantifier les effets du bruit des avions sur la santé en adoptant une approche globale caractérisant les relati...

Semaine du Cerveau 2018 : le CSGA mobilisé : Actualité du CSGA relative à l'experimentarium spécial cerveau, publiée le 5 mars 2018 par Ludovic Piquemal dans la newsletter du Centre INRA de Bourgogne-Franche-Comté sur inra.fr

OpenAIRE

2018-01-01

Pour la 20éme édition de la Semaine du Cerveau, les chercheurs du Centre des Science du Goût et de l'Alimentation se mobilisent auprès du public dijonnais à travers une conférence à Clénay sur les maladies neurodégénératives (samedi 17 mars) et en accueillant un Expérimentarium spécial cerveau (dimanche 18 mars).

Bourse du CRDI aux chercheurs candidats au doctorat 2018 | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Carrières · Communiquez avec nous · Plan du site. Abonnez-vous à notre bulletin pour recevoir les nouvelles du CRDI chaque mois. Abonnez-vous · Droits d'auteur · Éthique de la recherche · Politique de libre accès · Politique de confidentialité · Transparence · Utilisation du site Web. Suivez-nous; Facebook · Twitter ...

CONCEPTUALISATION ONTOLOGIQUE DE LA REPRÉSENTATION DU COMBAT CONCEPTUALISATION ONTOLOGIQUE DE LA REPRÉSENTATION DU COMBAT

Directory of Open Access Journals (Sweden)

Sylvain Rheault

2012-10-01

Full Text Available En adoptant une perspective existentielle, on peut tenter d'expliquer la représentation du combat au moyen de concepts comme les positions de SOI et de L'AUTRE ainsi que les statuts de l'ÊTRE et de la CHOSE, qui, une fois combinés, définissent des domaines ontologiques. Le combat devient alors, conceptuellement, l'action de forcer une conscience à passer d'un domaine à un autre. On observe qu'en modifiant l'intensité des positions (polarisation, des statuts (hiérarchisation et des actions (dosage, on peut expliquer les variations possibles des représentations du combat. Il restera à valider la pertinence de ces concepts en multipliant les analyses.En adoptant une perspective existentielle, on peut tenter d'expliquer la représentation du combat au moyen de concepts comme les positions de SOI et de L'AUTRE ainsi que les statuts de l'ÊTRE et de la CHOSE, qui, une fois combinés, définissent des domaines ontologiques. Le combat devient alors, conceptuellement, l'action de forcer une conscience à passer d'un domaine à un autre. On observe qu'en modifiant l'intensité des positions (polarisation, des statuts (hiérarchisation et des actions (dosage, on peut expliquer les variations possibles des représentations du combat. Il restera à valider la pertinence de ces concepts en multipliant les analyses.

Acceptabilité du test VIH proposé aux nourrissons dans les services pédiatriques, en Côte d'Ivoire, Significations pour la couverture du diagnostic pédiatrique

Science.gov (United States)

Oga, Maxime; Brou, Hermann; Dago-Akribi, Hortense; Coffie, Patrick; Amani-Bossé, Clarisse; Ékouévi, Didier; Yapo, Vincent; Menan, Hervé; Ndondoki, Camille; Timité-Konan, M.; Leroy, Valériane

2014-01-01

Résumé Problème: Le dépistage VIH chez les enfants a rarement été au centre des préoccupations des chercheurs. Quand le dépistage pédiatrique a retenu l'attention, cela a été pour éclairer seulement sur les performances diagnostiques en ignorant même que le test pédiatrique comme bien d'autres peut s'accepter ou se refuser. Cet article met au cœur de son analyse les raisons qui peuvent expliquer qu'on accepte ou qu'on refuse de faire dépister son enfant. Objectif: Etudier chez les parents, les mères, les facteurs explicatifs de l'acceptabilité du test VIH des nourrissons de moins de six mois. Méthodes: Entretien semi-directif à passages répétés avec les parents de nourrissons de moins de six mois dans les formations sanitaires pour la pesée/vaccination et les consultations pédiatriques avec proposition systématique d'un test VIH pour leur nourrisson. Résultats: Nous retenons que la réalisation effective du test pédiatrique du VIH chez le nourrisson repose sur trois éléments. Primo, le personnel de santé par son discours (qui dénote de ses connaissances et perceptions même sur l'infection) orienté vers les mères influence leur acceptation ou non du test. Secundo, la mère qui par ses connaissances et perceptions même sur le VIH, dont le statut particulier, l'impression de bien-être chez elle et son enfant influence toute réalisation du test pédiatrique VIH. Tertio, l'environnement conjugal de la mère, particulièrement caractérisé par les rapports au sein du couple, sur la facilité de parler du test VIH et sa réalisation chez les deux parents ou chez la mère seulement sont autant de facteurs qui influencent la réalisation effective du dépistage du VIH chez l'enfant. Le principe préventif du VIH, et le désir de faire tester l'enfant ne suffisent pas à eux seuls pour aboutir à sa réalisation effective, selon certaines mères confrontées au refus du conjoint. A l'opposé, les autres mères refusant la r

Effect of lactose on intestinal absorption of calcium; Effet du lactose sur l'absorption intestinale du calcium

Energy Technology Data Exchange (ETDEWEB)

Labat, Marie-Louise

1972-06-15

Calcium absorption was immediately increased when lactose was administered in large amounts in the intestine of standard rats fed on a vitamin D diet. The same effect could be reproduced with lactulose, a glucid un-hydrolyzed by lactase and unabsorbed. The occurrence of a saturation process for high doses of calcium agrees with a biochemical process through a carrier; this process was not inhibited by actinomycin D, which does not agree with a 'de novo' synthesis of a calcium binding protein; yet activation of the preexisting protein cannot be excluded. The intestinal effect of lactose resulted in an inhibition of bone catabolism in the adult normocalcemic rat indicating a possible interference of thyrocalcitonin. Finally in the young rat, hypocalcemic by lack of vitamin D, on account of the lactose effect, calcium can be considered as a 'third messenger' in the chain of intracellular events between the interaction of the parathyroid hormone with the bone receptor and the expression of its activity. (author) [French] Le lactose introduit en quantite importante dans l'intestin augmente immediatement l'absorption du calcium chez le rat normal recevant par ailleurs de la vitamine D. Cet effet peut etre reproduit par le lactulose, glucide non hydrolyse par la lactase et non absorbe. L'apparition d'un phenomene de saturation pour les doses elevees de calcium s'accorde avec un mecanisme biochimique mettant en jeu un transporteur. Ce mecanisme n'est pas inhibe par l'actinomycine D, ce qui ne s'accorde pas avec une synthese 'de novo' de proteine transporteuse liant le calcium; on ne peut toutefois exclure une activation de cette proteine preexistante. L'effet intestinal du lactose a pour consequence l'inhibition du catabolisme osseux chez le rat adulte normocalcemique; ceci pose le probleme d'une intervention eventuelle de la thyrocalcitonine. Enfin, l'effet lactose nous permet d'attribuer au calcium le role de 'troisieme messager' dans la chaine d

The fate of chylomicron cholesterol in the rat. 1. research into the storing of chylomicrons (1961); Destinee du cholesterol des chylomicrons chez le rat. 1. recherches sur le stockage des chylomicrons (1961)

Energy Technology Data Exchange (ETDEWEB)

Chevallier, F; Maurice, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

Rats conditioned to take their dally meal between midnight and 2 a.m. are given at midnight, by stomach tubing, 0,5 mg 4-{sup 14}C-cholesterol, and are sacrificed in the following hours. During the most active phase of intestinal absorption, specific radioactivities of free and esterified liver cholesterol and of serum cholesterol are practically equal. Consequently, captation of absorbed cholesterol by the liver is not detectable. The results obtained exclude, on the other hand, the possibility that the lungs might play a similar role. The problem of the fate of chylomicron cholesterol is discussed. In order to avoid any ambiguity in this discussion, we have determined the concentration and specific radioactivity of free and esterified cholesterol in chylomicrons and lymph obtained by continuous drainage of chyle. 5 p. 100 of the radioactive cholesterol of chyle are found in lymph: in chylomicrons, the radioactivity of free cholesterol is higher than that of esterified cholesterol. (authors) [French] Des rats, conditionnes a ingerer leur repas quotidien entre minuit et 2 heures, recoivent a minuit, par tubage gastrique 0,5 mg de cholesterol 4-C{sup 14} et sont sacrifies dans les heures qui suivent. Pendant la phase la plus active de l'absorption intestinale les valeurs des radioactivites specifiques du cholesterol libre et esterifie du foie, et du cholesterol du serum sont pratiquement egales. En consequence, la captation par le foie du cholesterol d'absorption n'est pas decelable. Les resultats obtenus permettent, par contre, d'exclure la possibilite pour les poumons de jouer un role analogue. Le probleme de la destinee du cholesterol des chylomicrons est discute. Pour ecarter toute ambiguite dans cette discussion, on a determine la concentration et la radioactivite specifique du cholesterol libre et esterifie dans les chylomicrons et la lymphe obtenus par le drainage continu du chyle. 5 p. 100 du cholesterol radioactif du chyle se trouve dans la lymphe; dans les

Image du savoir, image du pouvoir dans le Lapidaire

Directory of Open Access Journals (Sweden)

Marta LACOMBA

2007-01-01

Full Text Available À travers le prologue et les enluminures de présentation, le Lapidaire d’Alphonse X oriente l’interprétation de l’œuvre. Ces paratextes mettent en avant le rôle capital du savoir, représenté par la métaphore du trésor caché, qui a ici une valeur topique. Ils mettent également en exergue le rôle que s’attribue le roi dans la transmission de ce savoir, et placent cette nouvelle attribution royale au cœur de son projet politique.A través del prólogo y las miniaturas de presentación, el Lapidario de Alfonso X orienta la interpretación de la obra. Estos paratextos subrayan el papel capital del saber, representado por la metáfora del tesoro escondido, que tiene aquí un valor tópico. Ponen asimismo de manifiesto el papel que se atribuye el monarca en la transmisión de ese saber y colocan esta nueva atribución real en el centro de su proyecto político.

vARIATIONS MENSUELLES DURANT TROIS ANNÉES DU ...

African Journals Online (AJOL)

, Université .... ont reçu une alimentation à base de pâturage de. Panicum maximum avec ... Variations mensuelles durant trois années du nombre de spermatozoïdes par éjaculat et des paramètres de spermocytogramme du sperme de bélier ...

De l’occidentalisation du soufisme à la réislamisation du New Age ? Sufi Order International et la globalisation du religieux

Directory of Open Access Journals (Sweden)

Alix Philippon

2014-09-01

Full Text Available Sufi Order International (SOI a été fondé au début du xxe siècle en Occident et pour un public occidental par Hazrat Inayat Khan, un musicien et disciple de l’ordre soufi indien de la Chishtiyya. Ce groupe offre l’exemple d’un soufisme occidental ayant trouvé sa place dans la nébuleuse New Age en embrassant des formes syncrétiques de spiritualité et en mettant l’accent sur l’universalisme du message soufi, par-delà l’islam per se. En retour, ce soufisme occidental a commencé à féconder les terres musulmanes en répondant aux demandes d’une bourgeoisie libérale et occidentalisée réfractaires aux offres religieuses généralement disponibles sur place et qui a trouvé dans ce discours soufi universaliste une voie d’accès acceptable à l’islam, passé au tamis de la modernité religieuse. Au travers de terrains en Suisse et au Pakistan au sein de SOI, cet article vise à analyser les dynamiques du mode de croyance contemporain articulées avec celles de la mondialisation religieuse.

Risque de réémergence du paludisme au Maroc Étude de la capacité vectorielle d’Anopheles labranchiae dans une zone rizicole au nord du pays

Directory of Open Access Journals (Sweden)

Faraj C.

2008-12-01

Full Text Available Dans le but d’estimer le risque de réintroduction du paludisme au Maroc, nous avons analysé le potentiel paludogène d’une zone rizicole au nord du pays. Nos résultats ont montré que la capacité vectorielle d’An. labranchiae, vecteur du paludisme au Maroc, était particulièrement élevée pendant la période estivale qui correspond à la période de culture du riz. Le risque d’une reprise de la transmission du paludisme autochtone est élevé du fait de l’éventuelle présence de porteurs de parasite dans le dernier foyer de paludisme limitrophe de la zone d’étude. Le risque d’une introduction du paludisme tropical est faible, vu la faible vulnérabilité de la région et la compétence de ses vecteurs, considérée comme faible. Toutefois, ce risque doit faire l’objet d’une grande attention.

Temps du care et organisation sociale du travail en famille Time for Care and the social organization of work in a family context

Directory of Open Access Journals (Sweden)

Aurélie Damamme

2009-10-01

Full Text Available L’organisation du care en famille interroge les manières de restituer les activités que ce travail recouvre, les multiples agents qu’il implique, et les temporalités diverses qu’il engage. Si le sexe et la  disponibilité temporelle quasi-permanente permettent de rapprocher le care du travail domestique, c’est le travail de coordination sur le long cours qui vient spécifier le care, tout à la fois travail et éthique. L’effort de mise en cohérence des protagonistes, professionnels et non professionnels, membres de la famille et quasi-parents, défie les frontières entre privé et public. Processus d’intégration de différentes temporalités, le care est décrit comme agencement et enchaînement de phases. C’est par le souci d’assurer la continuité des soins que s’identifie alors la figure du principal responsable, engagée dans une temporalité qui la met souvent en porte-à-faux avec celle des organisations du travail contemporain. Pourtant, c’est bien par la reconnaissance de l’importance politique de ce temps de care que peuvent être bousculées les hiérarchies variées auxquelles il peut donner lieu, selon les lignes de genre, de classe et de race.The organization of Care in families challenges the ways the work accomplished by a wide range of agents and their various temporalities are accounted for. If gender and a quasi-permanent temporal availability allow one to combine Care and household work, it is the task of coordination in the long term that specifies Care, both as labour and ethics. Creating coherence between protagonists - professionals and non professionals, family members and quasi-relatives - challenges the separation between private and public spheres. As a process integrating different temporalities, Care is described as both an organization in itself and a sequence of phases. Maintaining continuity and coherence is identified as the main role and concern of the principal caregiver

Piquet Caroline, Histoire du canal de Suez, Paris, Perrin, 2009, 372 p.

Directory of Open Access Journals (Sweden)

Claudine Piaton

2011-01-01

Full Text Available Les études sur l'histoire du canal de Suez connaissent un regain d'intérêt chez les historiens français. Nathalie Montel avait ouvert la voie en 1998 en publiant un ouvrage passionnant sur le percement du canal, Le chantier du canal de Suez, 1859-1869. Une histoire des pratiques techniques. L'étude s'arrêtait à l'ouverture du canal en 1869, laissant le champ libre à de futurs travaux. La publication en 2008 de l'ouvrage de Caroline Piquet, La Compagnie du canal de Suez, une concession françai...

Les vicissitudes du fret ferroviaire

OpenAIRE

DABLANC, L

2010-01-01

Dans beaucoup de pays européens, et plus encore en Amérique du Nord et en Asie, le transport de marchandises par le train a augmenté depuis dix ans. Cette activité réduit la part des marchandises acheminées par la route et contribue ainsi au développement durable : un camion émet 8 à 30 fois plus de dioxyde de carbone que le train, pour une distance et une quantité transportée équivalentes. Pourtant, la France a raté ce renouveau. Filiale du groupe public SNCF, la Société Fret SNCF, qui assur...

L’écologie du coupable.

Directory of Open Access Journals (Sweden)

André Ourednik

2006-04-01

Full Text Available « Denn dass der Mensch erlöst werde von der Rache  : das ist mir die Brücke zur höchsten Hoffnung und ein Regenbogen nach langen Unwettern. » 1 Nous l’aurions presque oublié, en fouillant parmi les fondations du rapport moral au monde de nos sociétés, nous trouverons encore bien en place deux piliers érigés au cours du processus de la chrétienté : celui de l’ empathie et celui de la culpabilité . Le premier semble offrir le seul appui plausible à notre vivre ...

Brain stem hypoplasia associated with Cri-du-Chat syndrome

Energy Technology Data Exchange (ETDEWEB)

Hong, Jin Ho; Lee, Ha Young; Lim, Myung Kwan; Kim, Mi Young; Kang, Young Hye; Lee, Kyung Hee; Cho, Soon Gu [Dept. of Radiology, Inha University Hospital, Inha University School of Medicine, Incheon (Korea, Republic of)

2013-12-15

Cri-du-Chat syndrome, also called the 5p-syndrome, is a rare genetic abnormality, and only few cases have been reported on its brain MRI findings. We describe the magnetic resonance imaging findings of a 1-year-old girl with Cri-du-Chat syndrome who showed brain stem hypoplasia, particularly in the pons, with normal cerebellum and diffuse hypoplasia of the cerebral hemispheres. We suggest that Cri-du-Chat syndrome chould be suspected in children with brain stem hypoplasia, particularly for those with high-pitched cries.

Analyse du bruit dans un préamplificateur de harge en technologie ...

African Journals Online (AJOL)

Aussi la valeur de l'ENC total est essentiellement dominée par l'expression du bruit thermique du transistor d'entrée et cette derniere peut etre optimisée au détriment de la consommation en jouant sur ID. La valeur du courant de drain et le dimensionnement du transistor d'entrée sont décisifs pour le bruit. Mots-clés : bruit ...

Le discours rappporté comme effet de montage du discours citant et du segment citationnel. Contribution à l’étude du discours journalistique

Directory of Open Access Journals (Sweden)

Biardzka Elżbieta

2012-07-01

Full Text Available Dans notre étude, nous nous proposons un vaste retour aux données empiriques qui nous permettra de repérer et de décrire un dispositif sémantico-énonciatif et grammatical qui est à l'origine de la prolifération de pratiques du discours rapporté (désormais DR, codifiées et non codifiées, particulièrement répandues dans la presse écrite. Nous avons calculé nos résultats de recherche sur l'analyse d'un corpus journalistique d'à peu près 1500 exemples. Nous considérons le DR comme une séquence textuelle binaire, embrassant deux segments: le discours citant (DC qui verbalise les données situationnelles de l'énonciation primaire, et le segment citationnel (Cit qui représente les paroles. Compris de la sorte, le DR peut se figurer sous l'équation suivante: DR= DC + Cit. Nous envisageons le DC et la Cit comme des sortes de briques, mettons comme des Lego, qui entrent dans plusieurs combinaisons possibles pour donner naissance aux séquences du DR. Pour étudier le mécanisme qui les engendre, nous inventorions et décrivons les propriétés formelles et sémantico-énonciatives des segments DC et Cit. L'inventaire des formes grammaticales que peut revêtir le DC embrasse 6 cas de figures: la phrase introductive, la phrase complète, l'interrogation, l'incise, les syntagmes en "selon A", ensuite d'autres syntagmes, comme les syntagmes nominaux, adjectivaux, représentant des cas de différentes "incomplétudes" formelles et de réductions. La Citation, terme générique dans notre étude, recouvre trois types d'occurrences: les Citations reproductions, les Citations reformulations et les Citations mixtes. Les relations syntaxiques entres les deux segments du DR dépendent de la forme du DC et se définissent par deux cas de figure. Soit le journaliste rapporte les paroles de différentes personnes sans les assimiler à la syntaxe de son propre énoncé (combinatoire libre, soit il les intègre dans son discours conformément aux

Cholestéatome du méat acoustique externe

Science.gov (United States)

Azeddine, Lachkar; Aabach, Ahmed; Chouai, Mohamed; Elayoubi, Fahd; Ghailan, Mohamed Rachid

2016-01-01

Le cholestéatome du méat acoustique externe se définit comme une accumulation de kératine en regard d’une érosion osseuse de nature ostéitique. C’est une entité otologique rare ou peut diagnostiquée. Le but de notre travail est d’illustrer sur la base d’un cas un cholestéatome du méat acoustique externe. Il s’agit d’un patient âgé de 65 ans diabétique et hypertendu sous traitement, présentant depuis 3 mois une otalgie droite intense, insomniante, avec hypoacousie, otorrhée purulente minime et paralysie faciale droite grade V. Le diagnostic évoqué était dans un premier temps celui d’otite externe maligne. Il a été mis sous traitement antibiotique sans amélioration. L’examen otologique a trouvé une lésion ulcéro-bourgeonnante de la paroi postérieure du méat acoustique externe droit, une biopsie systématique de la lésion a été pratiquée et a conclu à un cholestéatome. Le patient a bénéficié d’une tympanoplastie en technique ouverte. Le cholestéatome du méat acoustique externe est rare, la symptomatologie clinique n’est pas spécifique, le scanner des rocher est d’un grand apport pour le diagnostic positif montrant un cratère osseux du méat acoustique externe. Le traitement dépend de l’extension des lésions allant des simples soins locaux à une tympanoplastie en technique ouverte. Le cholestéatome du méat acoustique externe peut revêtir plusieurs aspects, et prêter confusion avec d’autres pathologies du méat acoustique externe. PMID:28154624

Construction of the core of the 'heavy water-gas' reactor EL 4; Structures du coeur du reacteur 'eau- lourde-gaz EL 4'

Energy Technology Data Exchange (ETDEWEB)

Bernard, J L; Foulquier, H; Thome, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

problem of thermal insulation around a zirconium alloy liner tube. The neutron absorption equivalent is about 1, 1 mm of Al, and the mean loss around 2 p. 100 of the thermal power of the reactor. The methods proposed have proved practicable as a result of important research and developments on automatic remote control for all the operations which make up the sequences of mounting, demounting and repairing of the construction components. In particular the possibilities opened up by the new techniques of welding tubes from the inside have been extended to other problems connected with the assembling of a reactor. (authors) [French] Le coeur de ce reacteur est constitue par une cuve contenant l'eau lourde, cuve traversee d'une serie de tubes de force dans lesquels circule le gaz caloporteur sous pression de 60 at. Les specifications de depart qui ont joue un role important dans la conception de ces structures concernent des aspects de securite de fonctionnement (chargement du combustible par les deux faces du reacteur, remplacement des structures sur les deux faces du reacteur), des necessites neutroniques (absorption des structures minimum, pas du reseau, diametre des tubes de force) et des considerations thermiques (temperature de sortie 500 C). Ces specifications ont entraine une disposition horizontale des tubes de force et des problemes d'encombrement tres delicats qui ont elimine (pour les dimensions d'EL 4) toute possibilite de recourir a des compensateurs de dilatation sur les tubes de force. II s'ensuit un dessin de cuve semi-rigide dans lequel les tubes de force contribuent pour une part importante a la resistance mecanique de l'ensemble en jouant le role de tirant, d'ou des contraintes elevees sur les jonctions et tubes de force (et le choix des alliages de zirconium). Les structures comprennent le tube de force, les jonctions, l'isolement thermique et le tube de guidage. On expose brievement les moyens d'essais mis en oeuvre et les performances de ces diverses

Spectrographic determination of chlorine and fluorine; Dosage du chlore et du fluor par spectrographie d'emission en atmosphere inerte

Energy Technology Data Exchange (ETDEWEB)

Contamin, G. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-04-01

Experimental conditions have been investigated in order to obtain the highest sensitivity in spectrographic determination of chlorine and fluorine using the Fassel method of excitation in an inert atmosphere. The influence of the nature of the atmosphere, of the discharge conditions and of the matrix material has been investigated. The following results have been established: 1. chlorine determination is definitely possible: a working curve has been drawn between 10 {mu}g and 100 {mu}g, the detection limit being around 5 {mu}g; 2. fluorine determination is not satisfactory: the detection limit is still of the order of 80 {mu}g. The best operating conditions have been defined for both elements. (author) [French] Nous avons recherche quelles etaient les conditions permettant d'obtenir la meilleure sensibilite dans le dosage spectrographique du chlore et du fluor par la methode d'excitation en atmosphere inerte (methode de Fassel). Nous avons etudie l'influence de l'atmosphere gazeuse, des conditions de la decharge et du materiau de pastillage. Les points suivants ont ete etablis: 1. le dosage du chlore est possible: une courbe de dosage a ete tracee entre 10 {mu}g et 100 {mu}g et la limite de detection est de l'ordre de 5 {mu}g; 2. le dosage du fluor n'est pas satisfaisant: la limite de detection obtenue etant encore de l'ordre de 80 {mu}g. Les conditions operatoires ont ete precisees pour ces deux elements. (auteur)

La Rochelle – Rue du Docteur Schweitzer, hôpital

OpenAIRE

Nibodeau, Jean-Paul

2013-01-01

Identifiant de l'opération archéologique : 204575 Date de l'opération : 2008 (EX) Cette opération de diagnostic était engendrée par un projet de construction de parkings souterrains et de logements dans la partie sud de l'enceinte de l'hôpital de La Rochelle, sur une surface de 10 060 m2 . La prescription est motivée par la localisation des terrains entre l'enceinte urbaine du début du XVIIe  s. (porte Maubec et vestiges du bastion de Maubec découvert en 2004) et celle de la fin du XVIIe  ...

Le baptistère du Puy-en-Velay (Haute-Loire

Directory of Open Access Journals (Sweden)

Christian Sapin

2008-09-01

Full Text Available Traditionnellement désigné comme baptistère depuis le XIIIe siècle, cet édifice conservé au nord-est de la cathédrale du Puy est daté par la plupart des études antérieures du Xe siècle. En 2006, à partir du plan et des premiers travaux au sol, nous avions suggéré que les vestiges d’un massif quadrangulaire au niveau du sol, contre le mur nord, appartiennent à un rythme originel de piliers et grandes arcades murales, dont pouvaient subsister – selon les premières mesures d’espacement – des élé...

Identification d'une loi thermo-élasto-viscoplastique en vue de la modélisation du laminage à chaud du cuivre

Science.gov (United States)

Moureaux, P.; Moto Mpong, S.; Remy, M.; Bouffioux, C.; Lecomte-Beckers, J.; Habraken, A. M.

2002-12-01

la mise au point d'un modèle de simulation de la dernière passe du laminage à chaud du cuivre ne présente à priori pas de problème du point de vue numérique pour un code d'éléments finis non linéaire. La collecte d'informations précises tant sur le procédé industriel que sur le comportement du matériau est par contre une opération non triviale. Cet article présente les diverses méthodes expérimentales mises en œuvre pour caractériser le matériau : essais de compression à chaud, mesures d'analyse thermique différentielle, essais de dilatométrie et de diffusivité. Les méthodes permettant d'identifier les paramètres de la loi élasto-visco-plastique de type Norton-Hoff à partir des essais sont présentées et une analyse bibliographique investigue le problème de la détermination du module de Young à haute température. Tant les hypothèses supplémentaires relatives au procédé et nécessaires au modèle que les résultats finaux sont résumés.

World Gas Prospects: Which Role for the Middle East? Perspectives mondiales du gaz naturel : quel rôle pourrait jouer le Moyen-Orient ?

Directory of Open Access Journals (Sweden)

Chabrelie M. F.

2006-12-01

Full Text Available Since the early 1970s, the policies of energy diversification that have been implemented in the industrialized countries and in many developing countries have enabled natural gas to regularly increase its role in the world energy balance. Thus, during the past twenty years, natural gas recorded the highest growth rate among fossil fuels, and its share in the energy market has gradually risen from 18. 9% in 1975 to 23% in 1997. Today, thanks to favorable economic and environmental factors, natural gas has become the fuel of choice on many markets. Indeed, gas is blessed with a certain number of favorable assets (abundant reserves, flexibility, high-performance uses which give it a major role in all energy demand forecast scenarios. The most spectacular development will indisputably take place in the power generation sector. Endowed with a considerable gas potential, the Middle East will represent an essential source of supply for many industrialized countries and several gas export projects, either by LNG tanker or by pipelines are currently being contemplated. During the past decade, the contribution of natural gas to the energy mix also grew substantially in most Middle Eastern countries. The increase in gas demand should continue at a sustained rate, mainly driven by the power generation sector, petrochemicals and energy consumption by the hydrocarbons industry. These promising prospects for gas demand in most of the markets in the region might lead to the development of an intra-regional network. However, although opportunities exist, the region will have to meet many challenges in order to contribute more largely to the world gas balance in the years to come. de diversification énergétique mises en Suvre dans les pays industrialisés et dans de nombreux pays en voie de développement depuis le début des années 1970 ont permis au gaz naturel d'accroître régulièrement sa présence dans le bilan énergétique mondial. Ainsi, au cours des

An enhanced resolution of the structural environment of zirconium in borosilicate glasses

International Nuclear Information System (INIS)

Jollivet, P.; Angeli, F.; Bergeron, B.; Gin, S.; Calas, G.; Galoisy, L.; Ruffoni, M.P.; Trcera, N.

2013-01-01

The short- and medium-range local environment of zirconium was determined by Zr L 2,3 -edge and K-edge XANES and by Zr K-edge EXAFS in borosilicate glasses with 1 to 8 mol% ZrO 2 . Regardless of the ZrO 2 content of the glass, Zr is six-coordinated in octahedra with Zr-O distances of 2.09 Angstroms. In the glasses containing 8 mol% ZrO 2 , the octahedra are more distorted than at lower ZrO 2 content. Enhanced resolution in the real space is achieved by recording Zr K-edge EXAFS spectra over a broad energy range, enabling to get access k-values up to 20 Angstroems -1 with a high signal to noise ratio. This allows discriminate between the various second neighbor contributions. A correct fit is based on four Si and two B. This local structure around Zr derived from that of zircono-silicates such as elpidite, in which two Si are replaced by two B. The Zr-Si distances increase from 3.63 ± 0.02 to 3.67 ± 0.01 Angstroms, as Zr-B distances remain constant within uncertainties, as ZrO 2 content increases. Two Na are situated at 3.64 ± 0.03 Angstroms from Zr, ensuring charge compensation of the ZrO 6 sites. Increasing the CaO content from 4 to 8 mol% does not lead to any structural change around Zr. (authors)

Conceptual waste package interim product specifications and data requirements for disposal of borosilicate glass defense high-level waste forms in salt geologic repositories

International Nuclear Information System (INIS)

1983-06-01

The conceptual waste package interim product specifications and data requirements presented are applicable specifically to the normal borosilicate glass product of the Defense Waste Processing Facility (DWPF). They provide preliminary numerical values for the defense high-level waste form parameters and properties identified in the waste form performance specification for geologic isolation in salt repositories. Subject areas treated include containment and isolation, operational period safety, criticality control, waste form/production canister identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available

SOX2 plays a critical role in EGFR-mediated self-renewal of human prostate cancer stem-like cells.

Science.gov (United States)

Rybak, Adrian P; Tang, Damu

2013-12-01

SOX2 is an essential transcription factor for stem cells and plays a role in tumorigenesis, however its role in prostate cancer stem cells (PCSCs) remains unclear. We report here a significant upregulation of SOX2 at both mRNA and protein levels in DU145 PCSCs propagated as suspension spheres in vitro. The expression of SOX2 in DU145 PCSCs is positively regulated by epidermal growth factor receptor (EGFR) signaling. Activation of EGFR signaling, following the addition of epidermal growth factor (EGF) or ectopic expression of a constitutively-active EGFR mutant (EGFRvIII), increased SOX2 expression and the self-renewal of DU145 PCSCs. Conversely, a small molecule EGFR inhibitor (AG1478) blocked EGFR activation, reduced SOX2 expression and inhibited PCSC self-renewal activity, implicating SOX2 in mediating EGFR-dependent self-renewal of PCSCs. In line with this notion, ectopic SOX2 expression enhanced EGF-induced self-renewal of DU145 PCSCs, while SOX2 knockdown reduced PCSC self-renewal with EGF treatment no longer capable of enhancing their propagation. Furthermore, SOX2 knockdown reduced the capacity of DU145 PCSCs to grow under anchorage-independent conditions. Finally, DU145 PCSCs generated xenograft tumors more aggressively with elevated levels of SOX2 expression compared to xenograft tumors derived from non-PCSCs. Collectively, we provide evidence that SOX2 plays a critical role in EGFR-mediated self-renewal of DU145 PCSCs. © 2013.

Asie du sud | Page 38 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Asie du sud. Asie du sud. Read more about Advancing LDCs Interests in the WTO: Strengthening Participation, Securing Priorities (TTI). Langue English. Read more about Resserrement des réseaux pour la lutte contre les maladies infectieuses émergentes en Asie du Sud-Est et en Chine - 2e phase de l'APEIR. Langue ...

Gestion des risques naturels et prise en compte du développement durable : un lien équivoque. Le cas du sud grenoblois

Directory of Open Access Journals (Sweden)

Lauren Andres

2009-01-01

Full Text Available Cet article questionne la nature du lien envisageable entre risque naturel et développement durable à travers l’étude du territoire du sud grenoblois, soumis notamment à deux aléas naturels majeurs : le mouvement de terrain de grande ampleur dit des « Ruines de Séchilienne » et les probables crues de la Romanche et du Drac. Trois étapes structurent cette réflexion questionnant la transition supposée entre une gestion des risques naturels et une gestion durable des territoires soumis aux risques naturels : une association toute relative, un lien logique mais limité sur le terrain, une relation surtout indirecte. Les interactions identifiées, en termes législatifs mais aussi idéels et opérationnels, entre risque et durabilité se révèlent ainsi complexes et ne sont pas forcément explicites ; elles dépendent en particulier de multiples échelles territoriales (nationales à locales, confrontant alors pour l’essentiel des stratégies d’acteurs – porteurs des décisions ou du savoir technique – distinctes.

Webzzle : paradoxal confort du confinement.

Directory of Open Access Journals (Sweden)

Marc Dumont

2007-06-01

Full Text Available La plupart des agences de « news » technologiques viennent de se faire l’écho du développement de Webzzle , un nouveau moteur de recherche dit « collaboratif ». Ce cas est tout à fait intéressant parce qu’il permet de pointer rapidement quelques grands enjeux du Web 2 que risquent souvent de dissimuler la jungle sémantique et l’enthousiasme qui l’entourent. Pour quelles raisons ? Rappelons d’abord les deux principales perspectives ouvertes par cette nouvelle ...

An alternative for cost-effective remediation of depleted uranium (DU) at certain environmental restoration sites

International Nuclear Information System (INIS)

Miller, M.; Galloway, B.; VanDerpoel, G.; Johnson, E.; Copland, J.; Salazar, M.

2000-01-01

Numerous sites in the United States and around the world are contaminated with depleted uranium (DU) in various forms. A prevalent form is fragmented DU originating from various scientific tests involving high explosives and DU during weapon development programs, at firing practice ranges, or war theaters where DU was used in armor-piercing projectiles. The contamination at these sites is typically very heterogeneous, with discreet, visually identifiable DU fragments mixed with native soil. That is, the bulk-averaged DU activity is quite low, while specific DU fragments, which are distinct from the soil matrix, have much higher specific activity. DU is best known as a dark, black metal that is nearly twice as dense as lead, but DU in the environment readily weathers to a distinctive bright yellow color that is readily visible. While the specific activity of DU is relatively low and presents only a minor radiological hazard, the fact that it is radioactive and visually identifiable makes it desirable to remove the DU contamination from the environment

An alternative for cost-effective remediation of depleted uranium (DU) at certain environmental restoration sites

Energy Technology Data Exchange (ETDEWEB)

Miller, M.; Galloway, B.; VanDerpoel, G.; Johnson, E.; Copland, J.; Salazar, M.

2000-02-01

Numerous sites in the United States and around the world are contaminated with depleted uranium (DU) in various forms. A prevalent form is fragmented DU originating from various scientific tests involving high explosives and DU during weapon development programs, at firing practice ranges, or war theaters where DU was used in armor-piercing projectiles. The contamination at these sites is typically very heterogeneous, with discreet, visually identifiable DU fragments mixed with native soil. That is, the bulk-averaged DU activity is quite low, while specific DU fragments, which are distinct from the soil matrix, have much higher specific activity. DU is best known as a dark, black metal that is nearly twice as dense as lead, but DU in the environment readily weathers to a distinctive bright yellow color that is readily visible. While the specific activity of DU is relatively low and presents only a minor radiological hazard, the fact that it is radioactive and visually identifiable makes it desirable to remove the DU contamination from the environment.

Vers une (r)évolution du renseignement belge : la nécessaire émergence d'une communauté du renseignement

OpenAIRE

Leroy, Patrick

2017-01-01

Le renseignement belge entre dans une période de (r)évolution amenée par la crise des attentats qui secouent le sol européen. La tentations est grande pour les décideurs politiques de palier les "failles" du renseignement par des mesures radicales qui pourraient atteindre l'ADN, le coeur de métier du renseignement.

Le budget du CNRS de 1969 à 2000.

OpenAIRE

Marnot, Bruno

2011-01-01

Après avoir abordé l’évolution du budget du CNRS au cours « des années fastes » allant de la Libération à 1968 dans le précédent numéro de cette revue, Bruno Marnot poursuit ici son étude des budgets du Centre sur les trois décennies suivantes. Au cours de cette période, marquée par une conjoncture économique beaucoup moins brillante, les insuffisances budgétaires entraînent une importante diminution des moyens mis à la disposition des laboratoires et mènent à la crise de trésorerie qui sévit...

Analyses de la dégradation du lac Kinkony pour la conservation du ...

African Journals Online (AJOL)

Le lac Kinkony fait partie des habitats clefs pour la biodiversité du Complexe des ... provide favoured habitat for numerous endemic and endangered avian, fish ... on fauna is essential for developing regional conservation and natural resource ...

Lignes directrices du CRDI pour la préparation du rapport technique

International Development Research Centre (IDRC) Digital Library (Canada)

fdieudonne

l'accord de subvention et doivent faire partie de tout rapport hébergé dans la ... questions de nature délicate ou confidentielle doivent être traitées par un échange .... les innovations relevant des sciences, de la recherche ou du savoir;.

Du Mal-être au votre extrême

OpenAIRE

Gethin,, Amory; Jenmana,, Thanasak

2017-01-01

Note d'analyse de l'Observatoire du Bien-être du CEPREMAP; The rise of populism and the failure of traditional parties during the 2017 French presidential election calls to question the relevance of traditional determinants of voting. Given the difficult economic context associated with François Hollande’s term, to what extent has the increasing pessimism in France contributed towards anti-establishment voting?Available surveys reveal two remarkable phenomena. The extremes, particularly the e...

Étude comparée du Liber Judiciorum et du Fuero Juzgo

Directory of Open Access Journals (Sweden)

Estelle MAINTIER-VERMOREL

2009-04-01

Full Text Available Étant donné sa situation géographique, entre l’Europe et le monde arable, la Castille a joué un rôle particulièrement important, au Moyen Âge, dans le cadre des activités de traduction - notamment avec la célèbre École de Tolède ou les ateliers d’Alphonse X. Cette étude est centrée sur l’une de ces traductions, réalisée sous le règne de Ferdinand III, qui a représenté un point de départ dans le passage des textes officiels du latin au romance. Il s’agit du Fuero Juzgo, un ensemble de lois octroyé, pour la première fois, par Ferdinand III en 1241 à la ville de Cordoue et présenté comme la simple traduction du Liber Judiciorum, élaboré cinq siècles plus tôt dans les Conciles wisigothiques. Nous n’aborderons pas ici cette traduction d’un point de vue linguistique, mais historique et politique. Par le biais d’une comparaison détaillée des prologues des deux textes - qui constituent de véritables traités politiques portant sur le rôle du roi et ses relations avec l’Eglise - nous tenterons de démontrer comment le texte a pu être adapté, au travers de changements minimes mais nombreux et systématiques. Nous essaierons également de montrer pourquoi, dans un contexte de réunion entre Castille et León et également de grande extension du territoire, due à la Reconquête, cette réélaboration subtile du contenu peut être imputée à une manipulation à des fins politiques. Une manipulation, qui plus est, dotée d’une orientation très claire, c’est-à-dire en faveur du roi et au détriment de l’Église - un phénomène qui pourrait constituer les prémices de ce que l’on a coutume d’appeler la genèse de l’État moderne.Dada su situación geográfica, entre Europa y el mundo árabe, Castilla tuvo un papel particularmente importante en el marco de las actividades de traducción durante la Edad Media - especialmente con la famosa Escuela de Toledo o los talleres de Alfonso

Connaissances, attitudes, pratiques et appréciations du personnel ...

African Journals Online (AJOL)

Connaissances, attitudes, pratiques et appréciations du personnel médical du CHU-Tokoin sur le rôle de la pharmacie hospitalière dans sa mission d'appui au fonctionnement des unités de soins et de diagnostic.

Du Pont de Nemours

NARCIS (Netherlands)

Ros JPM; LAE

1994-01-01

Dit rapport over Du Pont de Nemours (produktie van o.a. chemische stoffen) is gepubliceerd binnen het Samenwerkingsproject Procesbeschrijvingen Industrie Nederland (SPIN). In het kader van dit project is informatie verzameld over industriele bedrijven of industriele processen ter ondersteuning

Une littérature du foyer : les livres de travaux manuels amateur

Directory of Open Access Journals (Sweden)

Claire Le Thomas

2008-04-01

Full Text Available Au cours du XIX e siècle naît une littérature entièrement voué au domicile : les manuels de travaux amateur. A travers ces livres se diffusent des usages dédiés à l’embellissement du logis ou à son entretien, c’est-à-dire de nouvelles occupations du temps libre qui accompagnent la transformation des représentations et des usages de l’espace domestique. Le mode d’exposition du discours sur la maison dans ces ouvrages amateur reflète ainsi l’intensité de l’engagement affectif et intellectuel concentré autour du foyer et dévoile la manière dont fut pensée et posée la problématique de l’habitat au cours de la seconde moitié du XIX e siècle.

Properties, use and health effects of depleted uranium (DU): a general overview

International Nuclear Information System (INIS)

Bleise, A.; Danesi, P.R.; Burkart, W.

2003-01-01

Depleted uranium (DU), a waste product of uranium enrichment, has several civilian and military applications. It was used as armor-piercing ammunition in international military conflicts and was claimed to contribute to health problems, known as the Gulf War Syndrome and recently as the Balkan Syndrome. This led to renewed efforts to assess the environmental consequences and the health impact of the use of DU. The radiological and chemical properties of DU can be compared to those of natural uranium, which is ubiquitously present in soil at a typical concentration of 3 mg/kg. Natural uranium has the same chemotoxicity, but its radiotoxicity is 60% higher. Due to the low specific radioactivity and the dominance of alpha-radiation no acute risk is attributed to external exposure to DU. The major risk is DU dust, generated when DU ammunition hits hard targets. Depending on aerosol speciation, inhalation may lead to a protracted exposure of the lung and other organs. After deposition on the ground, resuspension can take place if the DU containing particle size is sufficiently small. However, transfer to drinking water or locally produced food has little potential to lead to significant exposures to DU. Since poor solubility of uranium compounds and lack of information on speciation precludes the use of radioecological models for exposure assessment, biomonitoring has to be used for assessing exposed persons. Urine, feces, hair and nails record recent exposures to DU. With the exception of crews of military vehicles having been hit by DU penetrators, no body burdens above the range of values for natural uranium have been found. Therefore, observable health effects are not expected and residual cancer risk estimates have to be based on theoretical considerations. They appear to be very minor for all post-conflict situations, i.e. a fraction of those expected from natural radiation

Properties, use and health effects of depleted uranium (DU): a general overview

Energy Technology Data Exchange (ETDEWEB)

Bleise, A.; Danesi, P.R.; Burkart, W. E-mail: w.burkart@iaea.org

2003-07-01

Depleted uranium (DU), a waste product of uranium enrichment, has several civilian and military applications. It was used as armor-piercing ammunition in international military conflicts and was claimed to contribute to health problems, known as the Gulf War Syndrome and recently as the Balkan Syndrome. This led to renewed efforts to assess the environmental consequences and the health impact of the use of DU. The radiological and chemical properties of DU can be compared to those of natural uranium, which is ubiquitously present in soil at a typical concentration of 3 mg/kg. Natural uranium has the same chemotoxicity, but its radiotoxicity is 60% higher. Due to the low specific radioactivity and the dominance of alpha-radiation no acute risk is attributed to external exposure to DU. The major risk is DU dust, generated when DU ammunition hits hard targets. Depending on aerosol speciation, inhalation may lead to a protracted exposure of the lung and other organs. After deposition on the ground, resuspension can take place if the DU containing particle size is sufficiently small. However, transfer to drinking water or locally produced food has little potential to lead to significant exposures to DU. Since poor solubility of uranium compounds and lack of information on speciation precludes the use of radioecological models for exposure assessment, biomonitoring has to be used for assessing exposed persons. Urine, feces, hair and nails record recent exposures to DU. With the exception of crews of military vehicles having been hit by DU penetrators, no body burdens above the range of values for natural uranium have been found. Therefore, observable health effects are not expected and residual cancer risk estimates have to be based on theoretical considerations. They appear to be very minor for all post-conflict situations, i.e. a fraction of those expected from natural radiation.

Properties, use and health effects of depleted uranium (DU): a general overview.

Science.gov (United States)

Bleise, A; Danesi, P R; Burkart, W

2003-01-01

Depleted uranium (DU), a waste product of uranium enrichment, has several civilian and military applications. It was used as armor-piercing ammunition in international military conflicts and was claimed to contribute to health problems, known as the Gulf War Syndrome and recently as the Balkan Syndrome. This led to renewed efforts to assess the environmental consequences and the health impact of the use of DU. The radiological and chemical properties of DU can be compared to those of natural uranium, which is ubiquitously present in soil at a typical concentration of 3 mg/kg. Natural uranium has the same chemotoxicity, but its radiotoxicity is 60% higher. Due to the low specific radioactivity and the dominance of alpha-radiation no acute risk is attributed to external exposure to DU. The major risk is DU dust, generated when DU ammunition hits hard targets. Depending on aerosol speciation, inhalation may lead to a protracted exposure of the lung and other organs. After deposition on the ground, resuspension can take place if the DU containing particle size is sufficiently small. However, transfer to drinking water or locally produced food has little potential to lead to significant exposures to DU. Since poor solubility of uranium compounds and lack of information on speciation precludes the use of radioecological models for exposure assessment, biomonitoring has to be used for assessing exposed persons. Urine, feces, hair and nails record recent exposures to DU. With the exception of crews of military vehicles having been hit by DU penetrators, no body burdens above the range of values for natural uranium have been found. Therefore, observable health effects are not expected and residual cancer risk estimates have to be based on theoretical considerations. They appear to be very minor for all post-conflict situations, i.e. a fraction of those expected from natural radiation.

Structural role of molybdenum in nuclear glasses: an EXAFS study

International Nuclear Information System (INIS)

Calas, G.; Le Grand, M.; Galoisy, L.; Ghaleb, D.

2003-01-01

The Mo environment has been investigated in inactive nuclear glasses using extended X-ray absorption spectroscopy (XAS). Mo is present in a tetrahedron coordinated to oxygen in the form of molybdate groups [MoO 4 ] 2- (d(Mo-O)=1.78 A). This surrounding is not affected by the presence of noble metal phases in the nuclear glass. Relying on the XAS results, on the bond-valence model and on molecular dynamics simulations of a simplified borosilicate model glass, we show that these groups are not directly linked to the borosilicate network but rather located within alkali and alkaline-earth rich domains in the glass. This specific location in the glass network is a way to understand the low solubility of Mo in glasses melted under oxidizing conditions. It also explains the possible phase separation of a yellow phase enriched in alkali molybdates in molten nuclear glasses or the nucleation of calcium molybdates during thermal aging of these glasses. Boron coordination changes in the molten and the glassy states may explain the difference in the composition of the crystalline molybdates, as they exert a direct influence on the activity of alkalis in borosilicate glasses and melts

Promotion de la recherche sur l'entrepreneuriat en Asie du Sud-Est ...

International Development Research Centre (IDRC) Digital Library (Canada)

en Malaisie) assurera la coordination du projet, auquel participeront également la Chambre de commerce et de l'industrie du Vietnam, ... En Asie du Sud, la plupart des travailleurs ont un emploi mal rémunéré n'offrant aucune protection sociale.

Radioimmunodetection of human pancreatic tumor xenografts using DU-PAN II monoclonal antibody

International Nuclear Information System (INIS)

Nakamura, Kayoko; Kubo, Atsushi; Hashimoto, Shozo; Furuuchi, Takayuki; Abe, Osahiko; Takami, Hiroshi.

1988-01-01

The potential of DU-PAN II, monoclonal antibody (IgM), which was raised against the human tumor cell line, was evaluated for radioimmunodetection of human pancreatic tumors (PAN-5-JCK and EXP-58) grown in nude mice. 125 I-labeled DU-PAN II was accumulated into PAN-5-JCK producing DU-PAN II antigen with a tumor-to-blood ratio of 2.72 ± 3.00, but it did not localize in EXP-58 because of insufficient DU-PAN II. There was no significant uptake of 125 I-nonimmunized IgM in PAN-5-JCK. These facts indicated the specific tumor uptake of DU-PAN II. Excellent images of the tumor PAN-5-JCK were obtained 3 days after the injection of 125 I-DU-PAN II. Gel chromatography was also investigated with respect to the plasma taken from mice injected with antibody, or incubated with antibody in vitro. The results indicate that circulating antigen affected the tumor uptake of DU-PAN II: The more the tumor grew, the higher the amount of antigen excreted into the blood, leading to the degradation of DU-PAN II before it reached the tumor sites. Consequently, the immunoscintigram of the small tumor was remarkably clear. The catabolism and the radiolysis of the labeled IgM injected are critical points in applying immunoscintigraphy. (author)

Petites entreprises en Afrique: Clés du Changement

International Development Research Centre (IDRC) Digital Library (Canada)

Petites et moyennes entreprises — Politique gouvernementale — Afrique — ...... d'adhérer aux stratégies et aux politiques visant à assurer le développement ...... Qui plus est, les banques ont du mal à recruter du personnel de direction et de ...

Évaluation de l'importance du parcours Gadoudhé, dans l ...

African Journals Online (AJOL)

alimentation du bétail de la commune rurale de Fabidji au Niger. Méthodologie et résultats: Une enquête a été menée auprès des éleveurs de la commune rurale de Fabidji (Niger), sur l'utilité du parcours dans l'alimentation du bétail. Les résultats ...

Un programme de bourse novateur réunit des chercheurs du ...

International Development Research Centre (IDRC) Digital Library (Canada)

24 juin 2016 ... Eric Smith. Des chercheurs du Canada et d'Amérique latine travaillent conjointement à l'avancement du savoir dans un large éventail de disciplines et, ce faisant, font jaillir des idées et établissent des réseaux internationaux. En Colombie, par exemple, des chercheurs de l'Université Simon Fraser et du ...

Perception de la chimioprévention du paludisme saisonnier au Niger

African Journals Online (AJOL)

La chimioprévention du paludisme saisonnier (CSP) est une nouvelle stratégie recommandée par l'Organisation Mondiale de la Santé (OMS) depuis mars 2012 aux pays où la transmission du paludisme est saisonnière. Le programme national de lutte contre le paludisme (PNLP) du Niger a initié une étude pilote en 2013 ...

LA MEDITERRANEE DANS LES RELATIONS INTERNATIONALES DU XXE SIECLE

OpenAIRE

Lejeune , Dominique

2010-01-01

DEUG; Le monde est jugé dangereux et on voit resurgir les " ennemis héréditaires " ou des adversaires potentiels qui s'y substituent. De plus, l'expansion économique européenne provoque l'impatience d'ascension sociale, et la guerre va pouvoir libérer des énergies en 1914. Les ouvrages de guerre-fiction sont beaucoup plus nombreux après 1905 qu'auparavant ; la guerre est toujours présentée comme devant être courte, à cause de l'importance du nombre des mobilisés et du modernisme du matériel. ...

Quelques aspects de l'évolution géomorphologique quaternaire du haut bassin du Magdalena (Colombie

Directory of Open Access Journals (Sweden)

1974-01-01

Full Text Available Le bassin supérieur du Rio Magdalena présente les caractéristiques suivantes: 1 L'allure générale du bassin montre une influence très nette de la tectonique. Il s'est développé grâce à la présence d'un ensemble de blocs affaissés relativement les uns par rapport aux autres et entourés de blocs soulevés qui forment les limites du bassin. Dans certains cas des édifices volcaniques se superposent à ces blocs (Nevado del Huila, parâmes de Las Papas, par exemple. 2 Dans certaines parties du bassin (Nevado del Huila, environs du rio Mazamoras, et de Pitalito, le volcanisme s'est développé durant tout le Quaternaire. De la sorte, en général on observe un paroxysme volcanique durant la période d'accumulation de QIII dont la position géomorphologique est très semblable à celle du Mindel européen (Nebraska d'Amérique du Nord. Les matériaux volcaniques ont ainsi contribué à la mise en place de l'accumulation QIII mais cette accumulation n'est pas un produit du volcanisme car on l'observe bien développée dans des vallées ou il n'y eut aucune activité volcanique à cette époque. Ainsi, la mise en place du remplissage QIII provient d'une oscillation climatique. La granulométrie très grossière du matériel QIII provient de la combinaison du volcanisme et de cette oscillation climatique. 3 Dans le bassin, les événements morphogénétiques les plus saillants sont les suivants: - une incision extrêmement profonde des talwegs des avant l'accumulation de QIII cette incision a atteint au moins le niveau des rivières actuelles - la fossilisation des cañons incisés durant cette phase par l'accumulation très épaisse du matériel QIII. - postérieurement, a fonctionné une tendance très générale à l'incision uniquement interrompue par les phases d'accumulation QI et QII. Actuellement, cette incision n'est toujours pas arrivée au niveau atteint avant l'accumulation de QIII. Durant cette période d'incision des rivi

Genève au confluent du droit interne et du droit international : Mélanges offerts par la Faculté de droit de l'Université de Genève à la Société suisse des juristes à l'occasion du congrès 2012

OpenAIRE

Bellanger, François; de Werra, Jacques

2012-01-01

La Faculté de droit de l’Université de Genève est heureuse de perpétuer la tradition et d’offrir à la Société Suisse des Juristes le présent recueil de contributions à l’occasion de la tenue du Congrès 2012 à Genève. En écho à la thématique du Congrès qui est « Le droit suisse face aux défis du droit international », cet ouvrage présente quelques illustrations originales de l’interaction entre le droit interne et le droit international comme de l’apport du droit comparé et du droit internatio...

Etablissement du pollutogramme et de l'hydrogramme de la rivière ...

African Journals Online (AJOL)

Ecole d'Aquaculture de la Vallée, Université Nationale d'Agriculture, République du Bénin. ... obtenus ont montré qu'à partir du point de déversement des eaux provenant de la station d'épuration, .... qualité physico-chimique et biologique du.

Hydriding and dehydriding characteristics of small-scale DU and ZrCo beds

Energy Technology Data Exchange (ETDEWEB)

Chung, Dongyou; Lee, Jungmin; Koo, Daeseo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Chung, Hongsuk, E-mail: hschung1@kaeri.kr [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kim, Ki Hwan [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of); Kang, Hyun-Goo; Chang, Min Ho [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Camp, Patrick [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Jung, Ki Jung; Cho, Seungyon; Yun, Sei-Hun; Kim, Chang Shuk [National Fusion Research Institute, 113 Gwahakro, Yuseong, Daejeon 305-333 (Korea, Republic of); Yoshida, Hiroshi [Fusion Science Consultant, 3288-10 Sakado-cho, Mito-shi 310-0841, Ibakaki-ken (Japan); Paek, Seungwoo; Lee, Hansoo [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong, Daejeon 305-353 (Korea, Republic of)

2013-10-15

Highlights: • We have designed and fabricated a twosome small-scale getter bed for a comparison of ZrCo with DU on the hydriding/dehydriding properties. • We provide preliminary experimental results of our ZrCo and DU beds. -- Abstract: With the development of fusion technology, it will be necessary to store large amounts of tritium during the nuclear fusion fuel cycle. Stable metal tritides are viewed as potential candidates for the high-density storage of tritium. Metal tritide formers offer a safe and convenient method for tritium storage. For the storage, supply, and recovery of hydrogen isotopes, zirconium cobalt (ZrCo) and depleted uranium (DU) have been extensively proposed. Thus, we have designed and fabricated two identical small-scale getter beds for a comparison of ZrCo with DU on the hydriding/dehydriding properties. After the powderization of the metals, the hydriding/dehydriding performance at different stoichiometries of ZrCo and DU was measured. We provide preliminary experimental results of our ZrCo and DU beds.

EQUILIBRE GLYCEMIQUE ET COMPLICATIONS MACROANGIOPATHIQUES DU DIABETE

Directory of Open Access Journals (Sweden)

Lyse BORDIER

2017-05-01

Full Text Available La question de l’efficacité d’un équilibre glycémique optimal dans la prévention des complications macroangiopathiques du diabète a fait l’objet d’une récente polémique. Si les faits sont clairs pour la microangiopathie notamment au cours du diabète de type 1, ils paraissent moins certains pour les complications cardiovasculaires du diabète de type 2. Cette constatation vient de l’intrication des autres facteurs de risque cardiovasculaires qui sont très fréquents chez ces patients. Cependant, les études de suivi sur une longue durée s’inscrivent en faveur de l’intérêt d’un bon équilibre glycémique sur les complications macroangiopathiques. Les résultats négatifs sur la mortalité de l’étude ACCORD et les inquiétudes concernant la rosiglitazone ont conduit à la mise en place d’études sur la sécurité d’utilisation des nouvelles molécules. Tous ces travaux ont abouti à la démonstration de l’absence de risque des iDPP-4 et de l’effet très positif de certaines molécules de la classe des analogues du GLP-1 et des iSGLT2.Il reste à espérer que la récente mise au point de l’Académie de Médecine soulignant que les complications du diabète de type 2 exigent une prévention multifactorielle qui passe obligatoirement par un contrôle optimisé de l'équilibre glycémique mette fin à une polémique inutile et dangereuse pour nos malades.

Tour du canton de Genève 2017

CERN Multimedia

CERN Running club

2017-01-01

Pour rappel, le tour du canton est un évènement incontournable pour les coureurs de la région genevoise. Une épreuve qui a lieu le mercredi soir et qui se déroule sur 4 étapes.  Le Running Club du CERN a encore brillé cette année en obtenant de très bons résultats en individuel et surtout par équipe. L’équipe femme monte sur la première marche du podium (voir photo jointe) Les deux premières équipes hommes se classent 2e et 4e sur 51 équipes classées. Voir classement complet ici : http://www.sport-info.com/i_resultats.php?id=113

les cahiers du cread

African Journals Online (AJOL)

Our Journal “les cahiers du cread” is a quarterly economic review publishing original findings of empirical research and theoretical debates on fields pertaining to our mission coverage (Macro Economics, Industrial Economics and Firms, Human Development & Social Economics, Agriculture & Environment). Other websites ...

Groupement des anciens du CERN et de l'ESO

CERN Document Server

GAC-EPA

2011-01-01

Le GAC organise chaque mois des permanences avec entretiens individuels. La prochaine permanence se tiendra le Mardi 13 avril de 13h30 à 16h00 Salle de conférence de l’Association du personnel Les permanences suivantes auront lieu les mardis 4 mai, 1er juin, 7 septembre, 5 octobre, 2 novembre et 7 décembre. Les permanences du Groupement des Anciens sont ouvertes aux bénéficiaires de la Caisse de pensions (y compris les conjoints survivants !) et à tous ceux qui approchent de la retraite. Nous invitons vivement ces derniers à s’associer à notre groupement en se procurant, auprès de l’Association du personnel, les documents nécessaires. * * * * * Le Comité du GAC-EPA vous informe de la tenue de son Assemblée générale ordinaire 2011 Vendredi 25 mars 2011 à 14h00 dans l’Amphith&e...

Groupement des anciens du CERN et de l'ESO

CERN Document Server

GAC-EPA

2011-01-01

Le GAC organise chaque mois des permanences avec entretiens individuels. La prochaine permanence se tiendra le Mardi 8 mars de 13h30 à 16h00 Salle de conférence de l’Association du personnel Les permanences suivantes auront lieu les mardis 13 avril, 4 mai, 1er juin, 7 septembre, 5 octobre, 2 novembre et 7 décembre. Les permanences du Groupement des Anciens sont ouvertes aux bénéficiaires de la Caisse de pensions (y compris les conjoints survivants !) et à tous ceux qui approchent de la retraite. Nous invitons vivement ces derniers à s’associer à notre groupement en se procurant, auprès de l’Association du personnel, les documents nécessaires. * * * * * Le Comité du GAC-EPA vous informe de la tenue de son Assemblée générale ordinaire 2011 Vendredi 25 mars 2011 à 14h00 dans l’Amphithé&...

Le traumatisme du colon: l'expérience du CHU Hassan II de Fès

Science.gov (United States)

Benjelloun, El Bachir; Hafid, Hasnai; Karim, Ibnmajdoub; Ousadden, Abdelmalek; Mazaz, Khalid; Taleb, Kahlid Ait

2012-01-01

Introduction Les traumatismes du colon sont associés à un risque majeur de complications septiques et de mortalité. Le but de notre étude est d’évaluer les circonstances, la prise en charge, le suivi et les facteurs pronostic de morbidité postopératoire des malades victimes d'un traumatisme colique. Méthodes Il s'agit d'une étude rétrospective sur une série de 49 patients opérés pour des plaies coliques aux services de chirurgie viscérale du CHU HASSAN II de Fès sur une période de 8 ans de juillet 2003 à juillet 2011. Résultats L’âge moyen de nos patients était de 25ans (16-70) avec une nette prédominance masculine (93.8%). Les plaies coliques secondaires à un traumatisme par arme blanche représentent 85% des cas (42 patients), suivi par les plaies iatrogènes au cours d'une coloscopie chez 6 patients (13%), puis les contusions abdominales chez 1 patient (2%). Les parties du cadre colique les plus touchées étaient le colon transverse chez 19 patients (38%) et le colon descendant chez 12 patients (24, 5%). Le colon sigmoïde était le segment le plus touché au cours d'une coloscopie4/6. Quarante-deux patients (85%) ont eu une suture primaire des plaies coliques, six patients (13%) une diversion fécale et un patient (2%) une résection-anastomose. Deux patients (4%) sont décédés suite à un choc septique. La morbidité globale était de 38,7% dominé essentiellement par l'infection de la paroi chez 14 patients et une péritonite post opératoire chez 3 patients. L'analyse univarié a montré une différence significatif en terme d'infection de la paroi entre le groupe colostomie versus suture simple (50% vs 20,9% p<0,05). L'atteinte du colon gauche et la réalisation d'une colostomie sont associés à un risque plus élevés de complications postopératoires. Conclusion La suture primaire peut être effectuée avec un faible taux de complications postopératoire chez la majorité des patients suite à un traumatisme du colon. PMID

Marche du foncier urbain et promotion du logement au Benin ...

African Journals Online (AJOL)

Le marché du foncier urbain au Bénin est un secteur qui met en jeu l'intervention de plusieurs acteurs publics et privés mais également de l'informel. La notion de « foncier urbain » utilisée dans cet article englobe les acceptions et les utilisations faites en architecture, en urbanisme, en aménagement et en gestion urbaine.

Malformations du tube neural en chirurgie pediatrique du chu de ...

African Journals Online (AJOL)

encéphalocèle et 6 cas de sipina bifida. La cure chirurgicale a été le principal mode de prise en charge des patients. Seuls 91,38% des cas ont été opérés. Pour toutes les malformations du tube neural, nous avons enregistré 7 décès dont 2 décès ...

Entre l'authenticité et l’illusion : Macao, ville du patrimoine mondial et du jeu

OpenAIRE

Drouin, Martin

2012-01-01

Bordant la mer de Chine de chaque côté du delta de la rivière des Perles, Hong Kong et Macao ont fait rêver plus d’un voyageur. En dépit des similitudes évoquées, les deux destinations ne projettent pas du tout la même image. Leur contenu semble presque même s’opposer. Plus particulièrement, tel est le thème de la présente chronique, la place occupée par le patrimoine culturel dans l’expérience touristique diffère considérablement, malgré les transformations notables observées au cours des de...

Allocution prononcée par M. François de Rose, Président du Conseil de l'organisation européenne pour la recherche nucléaire à l'occasion de l'inauguration du synchrotron à protons du CERN le 5 février 1960

CERN Multimedia

CERN Press Office. Geneva

1960-01-01

Allocution prononcée par M. François de Rose, Président du Conseil de l'organisation européenne pour la recherche nucléaire à l'occasion de l'inauguration du synchrotron à protons du CERN le 5 février 1960

Sodium purification in Rapsodie; La purification du sodium a Rapsodie

Energy Technology Data Exchange (ETDEWEB)

Giraud, B [Commissariat a l' Energie Atomique, Dir. des Piles Atomiques, Cadarache (France). Centre d' Etudes Nucleaires

1968-07-01

This report is one of a series of publications presenting the main results of tests carried out during the start-up of the first french fast neutron reactor: Rapsodie. The article presents the sodium purification techniques used in the reactor cooling circuits both from the constructional point of view and with respect to results obtained during the first years working. (author) [French] Ce rapport fait partie d'une serie de publications presentant l'essentiel des resultats des essais effectues a l'occasion du demarrage du premier reacteur francais a neutrons rapides: RAPSODIE. Cet article expose les techniques de la purification du sodium utilise dans les circuits de refroidissement du reacteur tant au point de vue de leur realisation technologique, que des resultats obtenus pendant la premiere annee de fonctionnement. (auteur)

Résultats du traitement chirurgical des traumatismes du rachis à l ...

African Journals Online (AJOL)

incomplète était prédictive de bon pronostic P< 0,001. Les traumatismes du rachis cervical sont des urgences neurologiques qui mettent en jeu le pronostic vital et fonctionnel des patients. Mots clés : Traumatisme, rachis, traitement. The purpose of this series was to describe the results of surgical treatment of spinal injury.

Les dimensions émotionnelles du terrorisme

Directory of Open Access Journals (Sweden)

Benjamin Ducol

2013-10-01

Full Text Available Par une volonté louable de rompre avec des approches psychologisantes du phénomène terroriste dominantes au cours des années 1960-70, les recherches contemporaines en matière de terrorisme(s et de violence(s politique(s ont très largement mis l’emphase sur la figure du « terroriste » comme acteur rationnel et stratégique. Face aux limites des approches rationalistes de l’engagement radical qui envisagent de manière réductionniste les individus au travers d’un calcul rationnel univoque en terme de coûts et d’incitatifs à l’action, il nous apparaît important de réintégrer dans les réflexions théoriques sur les phénomènes terroristes, les émotions afin d’en interroger le rôle dans la production d’une trajectoire violente. Le présent article entend proposer à cet égard un bilan critique des travaux universitaires actuels autour de l’engagement terroriste et une réflexion théorique mettant en lumière les contours d’un futur agenda de recherche accordant une place plus importante aux ressorts émotionnels de la violence politique clandestine. Contemporary research on terrorism(s and political violence(s have largely put the emphasis on the figure of the "terrorist" as rational and strategic player, in a break with psychoanalytical approaches to terrorism that were dominant from the 1960-1970’s. Given the limitations of rationalist approaches to radical commitment, and considering how reductionist is the understanding of individual participation to terrorism related activities through a rational calculation framework in terms of costs and incentives to action, it is important to reintegrate in the theoretical reflections on terrorist phenomena how emotions can play a role in leading potential terrorists down a violent path. This paper presents a critical assessment of current academic work surrounding the issue of violent radicalization and involvement in terrorism, and engages in a theoretical debate

Recherche chronologique sur la culture mochica du Pérou : datation de la tombe du Prêtre de Sipán par thermoluminescence (TL) et par radiocarbone

OpenAIRE

Roque, Céline; Vartanian, Emmanuel; Guibert, Pierre; Schvoerer, Max; Lévine, Daniel; Alva, Walter; Jungner, Hogne

2007-01-01

La culture mochica du Pérou et le site de Sipán : problématique chronologiqueDe l’importance des recherches chronologiques sur la culture mochica du PérouLa culture Moche, ou mochica, est sans doute l’une des plus brillantes de l’époque pré-Inca. Elle s’épanouit sur la côte nord du Pérou, parallèlement aux civilisations Paracas Nécropolis et Nasca, qui se développent sur la côte sud du pays. Elle marque l’apogée d’un art particulièrement raffiné qui se manifeste notamment à travers l’orfèvrer...

Annealing of (DU-10Mo)-Zr Co-Rolled Foils

International Nuclear Information System (INIS)

Pacheco, Robin Montoya; Alexander, David John; Mccabe, Rodney James; Clarke, Kester Diederik; Scott, Jeffrey E.; Montalvo, Joel Dwayne; Papin, Pallas; Ansell, George S.

2017-01-01

Producing uranium-10wt% molybdenum (DU-10Mo) foils to clad with Al first requires initial bonding of the DU-10Mo foil to zirconium (Zr) by hot rolling, followed by cold rolling to final thickness. Rolling often produces wavy (DU-10Mo)-Zr foils that should be flattened before further processing, as any distortions could affect the final alignment and bonding of the Al cladding to the Zr co-rolled surface layer; this bonding is achieved by a hot isostatic pressing (HIP) process. Distortions in the (DU-10Mo)-Zr foil may cause the fuel foil to press against the Al cladding and thus create thinner or thicker areas in the Al cladding layer during the HIP cycle. Post machining is difficult and risky at this stage in the process since there is a chance of hitting the DU-10Mo. Therefore, it is very important to establish a process to flatten and remove any waviness. This study was conducted to determine if a simple annealing treatment could flatten wavy foils. Using the same starting material (i.e. DU-10Mo coupons of the same thickness), five different levels of hot rolling and cold rolling, combined with five different annealing treatments, were performed to determine the effect of these processing variables on flatness, bonding of layers, annealing response, microstructure, and hardness. The same final thickness was reached in all cases. Micrographs, textures, and hardness measurements were obtained for the various processing combinations. Based on these results, it was concluded that annealing at 650°C or higher is an effective treatment to appreciably reduce foil waviness.

Annealing of (DU-10Mo)-Zr Co-Rolled Foils

Energy Technology Data Exchange (ETDEWEB)

Pacheco, Robin Montoya [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alexander, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mccabe, Rodney James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clarke, Kester Diederik [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scott, Jeffrey E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel Dwayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Papin, Pallas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ansell, George S. [Colorado School of Mines, Golden, CO (United States)

2017-01-20

Producing uranium-10wt% molybdenum (DU-10Mo) foils to clad with Al first requires initial bonding of the DU-10Mo foil to zirconium (Zr) by hot rolling, followed by cold rolling to final thickness. Rolling often produces wavy (DU-10Mo)-Zr foils that should be flattened before further processing, as any distortions could affect the final alignment and bonding of the Al cladding to the Zr co-rolled surface layer; this bonding is achieved by a hot isostatic pressing (HIP) process. Distortions in the (DU-10Mo)-Zr foil may cause the fuel foil to press against the Al cladding and thus create thinner or thicker areas in the Al cladding layer during the HIP cycle. Post machining is difficult and risky at this stage in the process since there is a chance of hitting the DU-10Mo. Therefore, it is very important to establish a process to flatten and remove any waviness. This study was conducted to determine if a simple annealing treatment could flatten wavy foils. Using the same starting material (i.e. DU-10Mo coupons of the same thickness), five different levels of hot rolling and cold rolling, combined with five different annealing treatments, were performed to determine the effect of these processing variables on flatness, bonding of layers, annealing response, microstructure, and hardness. The same final thickness was reached in all cases. Micrographs, textures, and hardness measurements were obtained for the various processing combinations. Based on these results, it was concluded that annealing at 650°C or higher is an effective treatment to appreciably reduce foil waviness.

Solidification of Savannah River Plant high-level waste

International Nuclear Information System (INIS)

Maher, R.; Shafranek, L.F.; Stevens, W.R. III.

1983-01-01

The Department of Energy, in accord with recommendations from the Du Pont Company, has started construction of a Defense Waste Processing Facility (DWPF) at the Savannah River Plant. The facility should be completed by the end of 1988, and full-scale operation should begin in 1990. This facility will immobilize in borosilicate glass the large quantity of high-level radioactive waste now stored at the plant plus the waste to be generated from continued chemical reprocessing operations. The existing wastes at the Savannah River Plant will be completely converted by about 2010. 21 figures

Savannah River Laboratory's operating experience with glass melters

International Nuclear Information System (INIS)

Brown, F.H.; Randall, C.T.; Cosper, M.B.; Moseley, J.P.

1982-01-01

The Department of Energy, with recommendations from the Du Pont Company, is proposing that a Defense Waste Processing Facility be constructed at the Savannah River Plant to immobilize radioactive The immobilization process is designed around the solidification of waste sludge in borosilicate glass. The Savannah River Laboratory, who is responsible for the solidification process development program, has completed an experimental program with one large-scale glass melter and just started up another melter. Experimental data indicate that process requirements can easily be met with the current design. 7 figures

Le developpement olympique du kayak Africain : Anglophonie vs ...

African Journals Online (AJOL)

Si le kayak de slalom s'est développé récemment en Afrique (premier Championnat continental organisé en 2009), il a été médiatisé à la faveur de sa reconnaissance olympique. Mais quels sont les enjeux culturels du développement olympique du kayak en Afrique francophone ? Comment cette activité a-t-elle pu ...

Françoise Battagliola, Histoire du travail des femmes

Directory of Open Access Journals (Sweden)

Barbara Rist

2009-06-01

Full Text Available Initialement paru en 2000, l’ouvrage de Françoise Battagliola vient de bénéficier d’une nouvelle édition : en une centaine de pages denses et bien documentées, l’auteure y brosse un parcours passionnant de l’histoire du travail des femmes en France depuis les débuts de l’industrialisation jus-qu’à la fin du XXe siècle.Le propos s’organise, en gros, selon un axe chronologique, lequel sert de fil conducteur à une problématique voulant éclairer l’histoire, non « des femmes ou du féminin mais des...

Hepatiques du Surinam

NARCIS (Netherlands)

Jovet-Ast, S.

1957-01-01

Il n’existe pas, actuellement, de catalogue des Hépatiques du Surinam. Les Hépatiques de ce pays restent très peu connues. Cependant, certaines ont attiré l’attention des Bryologues et ont été citées dans quelques ouvrages anciens ou récents. Je ne ferai pas ici une révision complète de ces

Measurement of the thermal utilisation factor of the reactor G1; Mesure du facteur d'utilisation thermique du reacteur G1

Energy Technology Data Exchange (ETDEWEB)

Roullier, F; Schmitt, A P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

The thermal utilisation factor of the lattice of the reactor G1 has been measured by applying the autoradiographic technique to thin detectors irradiated in the cell. The experimental apparatus is described, and the results compared with those obtained by calculation based on various formulae. The results of the study of the thermal flux distribution in a cell containing a thorium rod of the same diameter as the uranium rods in the lattice are also given. The precision of the measurements is discussed. Value found: f diameter 26 = 0.8949 {+-} 0,005. (author) [French] Le facteur d'utilisation thermique du reseau du reacteur G1 a ete mesure en appliquant la technique de l'autoradiographie a des detecteurs minces irradies dans la cellule. Les dispositifs experimentaux sont decrits et les resultats sont compares a ceux obtenus par le calcul a partir de diverses formules. Les resultats de l'etude de la distribution du flux thermique dans une cellule contenant une barre de thorium de meme diametre que les barres d'uranium du reseau sont egalement indiques. La precision des mesures est discutee. Valeur trouvee: f diametre 26 = 0,8949 {+-} 0,005. (author)

An alternative for cost-effective remediation of depleted uranium (DU) at certain environmental restoration sites.

Science.gov (United States)

Miller, M; Galloway, B; VanDerpoel, G; Johnson, E; Copland, J; Salazar, M

2000-02-01

Numerous sites in the United States and around the world are contaminated with depleted uranium (DU) in various forms. A prevalent form is fragmented DU originating from various scientific tests involving high explosives and DU during weapon development programs, at firing practice ranges, or war theaters where DU was used in armor-piercing projectiles. The contamination at these sites is typically very heterogeneous, with discreet, visually identifiable DU fragments mixed with native soil. That is, the bulk-averaged DU activity is quite low, while specific DU fragments, which are distinct from the soil matrix, have much higher specific activity. DU is best known as a dark, black metal that is nearly twice as dense as lead, but DU in the environment readily weathers (oxidizes) to a distinctive bright yellow color that is readily visible. While the specific activity (amount of radioactivity per mass of soil) of DU is relatively low and presents only a minor radiological hazard, the fact that it is radioactive and visually identifiable makes it desirable to remove the DU "contamination" from the environment. The typical approach to conducting this DU remediation is to use radiation detection instruments to identify the contaminant and separate it from the adjacent soil, packaging it for disposal as radioactive waste. This process can be performed manually or by specialized, automated equipment. Alternatively, in certain situations a more cost-effective approach might be simple mechanical or gravimetric separation of the DU fragments from the host soil matrix. At SNL/NM, both the automated and simple mechanical approaches have recently been employed. This paper discusses the pros/cons of the two approaches.

Entering of Stefan Dušan into the Empire

Directory of Open Access Journals (Sweden)

Pirivatrić Srđan

2007-01-01

Full Text Available At the moment when, in October 1341, a new Civil War broke out in the Byzantium after the death of Andronicus III, the traditional views of the imperial power and the Empire underwent considerable changes. The powers of the co-rulers had been on the rise since 1272, and during the Civil War of 1321-1328 the Byzantine Empire was in effect divided, that is, two Basileis were ruling 'imperially' (autokratorikōs over their respective territories within the formally unified Empire, under the scope of relations of Superior basileus - co-basileus. Therefore, the Empire (autokratoria, imperium could multiply in the sense of rulers’ authorities, and be divided in the sense of territoriality. The imperial power and the Empire became subject to family relations and family law. In view of the family connections between the Byzantine Emperors (basileis autokratores and the monarchs of the neighboring countries and nations, the right to succession was being used as an argument in some disputes between the rulers. The Byzantine law, that is the Byzantine political views, allowed for the possibility of the so-called 'joint rule' (e oikeia arch by a Byzantine basileus autokrator and some other, foreign member of the dynasty ruling over certain region of the Byzantine Empire - a foreign ruler would be allowed to rule on condition that the Byzantine basileus be recognized as the supreme master. This scenario is known from one recorded dispute between the Byzantine basileus Andronicus III and the Bulgarian tsar Michael Assen III dating from 1328, when the Bulgarian Emperor did not accept the Byzantine rule, however. All these circumstances are of special importance since they directly precede the King Stefan Dušan’s involvement in the Civil War, that is, his later entering into the Empire. The first phase of Dušan’s involvement in the Civil War is typically conquering and opportunistic in nature, with the aim of immediate territorial enlargement. The

Des solutions fiscales pour une réduction optimale du tabagisme en ...

International Development Research Centre (IDRC) Digital Library (Canada)

Centre de recherches pour le développement international Gouvernement du Canada ... taxation du tabac, l¿insuffisance de données probantes locales constitue ... de taxes sur les recettes fiscales de leur gouvernement et sur la santé publique, et de ... Dans ce bulletin du BRAS: Faites connaissance avec Kathryn Touré, ...

Processus d'innovation et recomposition des territoires agricoles : le cas du semis sous couvert végétal au nord du Cameroun

OpenAIRE

Dugué, Patrick; Olina Bassala, Jean-Paul

2015-01-01

Au nord du Cameroun, l'adoption des systèmes de culture sous couvert végétal (SCV) butte sur le partage des résidus de culture fourragers en saison sèche entre le bétail et la couverture du sol. Elle nécessite donc d'accroître l'offre fourragère et de prendre en compte les différents types d'élevage (villageois, semi-sédentaire, transhumant, etc.). Dans les conditions actuelles de pratique des SCV par les producteurs (faible couverture du sol, peu d'années successives en SCV) les effets atten...

Autonomie du groupe restreint et performance

Directory of Open Access Journals (Sweden)

Elke Nissen

2005-09-01

Full Text Available Un groupe est autonome lorsqu'il prend lui-même en charge sa gestion (Abric, 1996 et lorsque celle-ci fonctionne bien. L'autonomie du groupe restreint est une caractéristique revendiquée dans le cadre actuel de l'expansion de dispositifs collaboratifs à distance entre apprenants. La question qui se pose alors est de savoir si un groupe restreint autonome est plus performant qu'un groupe moins autonome. L'autonomie d'un groupe d'apprentissage en ligne est-elle en relation avec la qualité de la réalisation de la tâche ? Est-elle en relation avec les progrès réalisés par les membres du groupe ? Dans le cadre de notre étude expérimentale, menée dans deux dispositifs pédagogiques différents (l'environnement d'apprentissage Babbelnet et une formation sur la plate-forme Acolad, des étudiants ont réalisé en groupes restreints, avec l'accompagnement d'un tuteur, une tâche de type actionnel – en l'occurrence une rédaction en langue étrangère (allemand ou anglais. Pour ce faire, ils disposaient d'aides méthodologiques et linguistiques dans l'environnement pédagogique en ligne. Ils ont interagi par le biais d'Internet au moyen de différents outils de communication. Une analyse de l'interaction qui a eu lieu dans chaque groupe, l'évaluation des rédactions réalisées conjointement, deux tests réalisés respectivement avant et après la phase de travail en groupe ainsi qu'un formulaire auto-administré nous permettent de mettre en lien l'autonomie des groupes, d'une part, et leur performance, voire leur apprentissage, d'autre part. Au vu de cette étude, il apparaît que l'autonomie du groupe n'a pas d'influence directe sur l'apprentissage des groupes restreints. En revanche, un rapport est visible entre l'appréciation du fonctionnement du groupe par ses membres et l'évolution de la performance des groupes.

Gestion du parc agroforestier du terroir de Vipalogo (Burkina Faso ...

African Journals Online (AJOL)

Au Burkina Faso, l'arbre rural fait partie des systèmes de production. Le choix des espèces, leur densité, les modes de gestion ainsi que les besoins à satisfaire, obéissent à des critères propres aux producteurs. C'est pour comprendre ces logiques paysannes de la gestion du parc agroforestier que la présente étude a été ...

DuPont Chemical Vapor Technical Report

International Nuclear Information System (INIS)

MOORE, T.L.

2003-01-01

DuPont Safety Resources was tasked with reviewing the current chemical vapor control practices and providing preventive recommendations on best commercial techniques to control worker exposures. The increased focus of the tank closure project to meet the 2024 Tri-Party Agreement (TPA) milestones has surfaced concerns among some CH2MHill employees and other interested parties. CH2MHill is committed to providing a safe working environment for employees and desires to safely manage the tank farm operations using appropriate control measures. To address worker concerns, CH2MHill has chartered a ''Chemical Vapors Project'' to integrate the activities of multiple CH2MHill project teams, and solicit the expertise of external resources, including an independent Industrial Hygiene expert panel, a communications consultant, and DuPont Safety Resources. Over a three-month time period, DuPont worked with CH2MHill ESH and Q, Industrial Hygiene, Engineering, and the independent expert panel to perform the assessment. The process included overview presentations, formal interviews, informal discussions, documentation review, and literature review. DuPont Safety Resources concluded that it is highly unlikely that workers in the tank farms are exposed to chemicals above established standards. Additionally, the conventional and radiological chemistry is understood, the inherent chemical hazards are known, and the risk associated with chemical vapor exposure is properly managed. The assessment highlighted management's commitment to addressing chemical vapor hazards and controlling the associated risks. Additionally, we found the Industrial Hygiene staff to be technically competent and well motivated. The tank characterization data resides in a comprehensive database containing the tank chemical compositions and relevant airborne concentrations

Autour du paradigme d’écotourisme

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Anne-Laure Transler

2008-02-01

Full Text Available L’écotourisme ouvre un cadre conceptuel original qui permet d’envisager des démarches renouvelées de développement à partir des revenus issus de consommations touristiques mieux réfléchies et organisées, susceptibles de soutenir des initiatives de développement local s’inscrivant dans un projet global de développement durable. Variante douce du tourisme, loin du tourisme de masse, le champ de l’écotourisme s’étend aux confins du tourisme de nature, du tourisme culturel et des pratiques scientifiques et sportives de plein air. Une définition de l’écotourisme peut être proposée à partir des six points suivants : 1/ nature et culture, 2/ le bien-être des sociétés hôtes, 3/ des touristes responsables, 4/ la participation des sociétés hôtes, 5/ la durabilité, 6/ l’art de la rencontre.Ecotourism provides an original conceptual framework that enables approaches to development that are better able to provide a more equitable distribution of income, as well as better organized and thought through initiatives which are more likely to promote a holistic sustainable local development. With somewhat less negative impact than normal tourism, considerably less that mass tourism, ecotourism can encompass nature tourism, cultural tourism, scientific exploration, and even outdoor sports... A definition of ecotourism should take into account the following six points: 1/ nature and culture, 2/ the welfare of the host community, tourists acting responsibly, 3/ participation by the local community, 5 / sustainability , 6/ promotion of cultural exchanges

La question de la géométrie du lexique

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Polguère Alain

2016-01-01

Full Text Available Cet article s’intéresse à la structure globale du lexique, en tant que module fonctionnel de la langue, et à ses possibles représentations formelles. Nous posons tout d’abord le problème de la représentation de la connaissance lexicale, en expliquant l’importance d’adopter une métaphore géométrique du lexique qui soit adaptée à l’étude lexicologique et à ses diverses applications. Cela nous amène préciser la nature même du lexique qui doit faire l’objet d’une telle géométrisation en revenant sur la notion souvent galvaudée de lexique mental et en distinguant deux types de lexiques mentaux – le lexique logique et le lexique physiologique –, dont seul le premier est notre objet d’étude. Après avoir examiné les principales métaphores courantes du lexique logique, nous présentons un modèle formel plausible, sur lequel s’appuie notamment le projet du Réseau Lexical du Français : il s’agit des Systèmes Lexicaux, dont la charpente structurale est constituée par les fonctions lexicales Sens-Texte.

Business plan pour une application Smartphone : du concept au lancement

OpenAIRE

Vriamont, Gilles

2015-01-01

Création d'une application mobile pour Smartphone. Description théorique concernant la rédaction d'un business plan dans une première partie suivi d'une description théorique des caractéristiques des applications mobiles. Dans une seconde partie, analyse de l'industrie des Smartphones et des applications mobiles suivi de la partie pratique et du développement du produit, partant de la description du produit jusqu'à l'analyse des coûts. Master [120] en Ingénieur de gestion, Université catho...

Les physiciens du CERN se font batisseurs de cavernes

CERN Multimedia

Augereau, J F

2002-01-01

Pour percer les secrets bien gardes de la nature, en particulier les origines de la masse, les chercheurs vont installer dans une de ces grottes un enorme detecteur de particules. Atlas, c'est son nom, sera place sur le trace du plus grand accelerateur du monde pour recueillir des indices (1 page).

À « l’ombre du Père » ? L’autorité maternelle dans la première moitié du XVIIIe siècle

OpenAIRE

DOYON, Julie

2007-01-01

Du renforcement de la « monarchie paternelle » à l’existence d’un « empire des mères », la confrontation des sources du droit civil et des archives criminelles du Châtelet, au premier XVIIIe siècle, donne une vision complexe des rapports noués entre l’expérience de la maternité et l’exercice de l’autorité. Statutairement, les mères légitimes sont associées, sur un mode mineur ou de plein droit dans le cas du veuvage et de l’institution tutélaire, à l’exercice de l’autorité paternelle. Mais en...

Choeur du CERN : Concert

CERN Multimedia

CERN Choir

2017-01-01

Une œuvre à découvrir! La grande Missa pro defunctis de François-Joseph Gossec (1734-1829) est le chef-d’œuvre tôt venu (à vingt-cinq ans) d’un compositeur qui vivra encore 70 ans après sa création. Elle a connu la gloire, puis s’est fait un peu oublier. Pas du tout le monde cependant : des musicologues ont montré ce que le Requiem de Mozart lui devait ; et il suffit de l’avoir entendue pour comprendre pourquoi Berlioz (qui avait vingt-six ans à la mort de Gossec) en a été impressionné : les nombreux cuivres et bois répartis dans des endroits plus ou moins cachés de la salle de concert pour exprimer les frayeurs du Jugement dernier annoncent son Requiem – et celui de Verdi. Mais « plus encore que par...

l'algerie, du transfert de technologie a l'economie du savoir

African Journals Online (AJOL)

Abdelkader DJEFLAT

sphère académique et l'entreprise, ni négocié correctement par la sphère de la ... La stratégie d'import-substitution poursuivie et les politiques mises en ...... formation adéquate a été à l'origine du bas niveau de recrutement des diplômés et de ...

Réseautage d'entreprises au Moyen-Orient et en Afrique du Nord ...

International Development Research Centre (IDRC) Digital Library (Canada)

Les réseaux sociaux sont d'importantes sources de conseils pour les entrepreneurs du Moyen-Orient et de l'Afrique du Nord (région MOAN) et ils contribuent à leur réussite. Un nouveau projet de recherche a pour but de favoriser la collaboration entre des chercheurs du Global Entrepreneurship Monitor (GEM) et la ...

L’art du vitrail en France au temps de la reconstruction et de la croissance. Note sur les fonds Hébert-Stevens - Bony conservés aux Archives nationales du monde du travail (Fonds n° 2002 001

Directory of Open Access Journals (Sweden)

Christian Hottin

2009-11-01

Full Text Available Cet article a pour objet de présenter brièvement le fonds de l’atelier Hébert-Stevens - Bony, entré aux Archives nationales (Archives nationales du monde du travail, Roubaix en 2002

L'Afrique, nouvel Eldorado du commerce | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

5 déc. 2013 ... Il est directeur du Perimeter Institute for Theoretical Physics, où il est également titulaire de la chaire Mike and Ophelia Lazaridis Niels Bohr. Thierry Zomahoun, M.B.A., M.Ph., est directeur général de l'AIMS Next Einstein Initiative (AIMS-NEI) et directeur du secrétariat mondial d'AIMS. Cet article a été publié ...

Un établissement du début du premier âge du Fer en Eure-et-Loir : Sours, Les Ouches A settlement from the first Iron Age in Eure-et-Loir: Sours, Les Ouches

Directory of Open Access Journals (Sweden)

Frédéric Dupont

2012-01-01

Full Text Available La fouille du site des Ouches à Sours (28 a permis la mise au jour d’une importante occupation du Néolithique ancien et la découverte, dans la partie nord de l’emprise, de plusieurs structures datables du début de l’âge du Fer (Hallstatt C. Elles correspondent à des structures domestiques (un bâtiment et des fosses et à une entité “ cultuelle ”: un double enclos en “ U ”.L’habitation et ses annexes sont représentées par un bâtiment de plan quadrangulaire sur poteaux et une grande fosse riche en mobilier (céramiques, ossements et silex taillés. Cette structure peut être associée au fonctionnement d’un four de type “ polynésien ” et avoir servi de fosse de rejet.Le double enclos, ouvert vers le nord, est localisé au nord-est du site.Même si trois céramiques entières ont été trouvées dans son fossé externe, l’essentiel du mobilier céramique (177 individus sur 192 est issu de la grande fosse. Il s’agit principalement de coupes, de jattes parfois incisées, de petits gobelets à panse globulaire typiques du Hallstatt C ou de vases servant au stockage. Ils sont dotés de manière régulière de cordons digités.Ce petit établissement du début de l’âge du Fer a livré un bon échantillon des céramiques en usage en Eure-et-Loir à cette époque ainsi que des vestiges archéozoologiques et lithiques en quantité intéressante. Ces découvertes donnent de nouvelles informations sur les affinités culturelles à la transition entre l’âge du Bronze et l’âge du Fer, période peu documentée dans le Nord de la région Centre.The excavation of the site of Ouches at Sours (28 has enabled the updating of an important settlement from the early Neolithic and the discovery, in the northern part of the site, of several structures datable to the beginning of the Iron Age (Hallstatt C. They correspond to domestic structures (a building and some ditches and a “worship” entity: a double

pluviosite en region soudano-sahelienne au nord du cameroun

African Journals Online (AJOL)

AISA

Dans le but de montrer qu'en zone soudano-sahélienne du Nord du ... principaux facteurs responsables de la variation des rendements en culture pluviale, une étude basée sur ... Mots clés : Risque climatique, pluviométrie, variation, rendement agricole, Nord Cameroun. ... d'analyse plus global et fonctionnel, à savoir,.

Etude Du Comportement Dynamique D'un Systeme De Pompage ...

African Journals Online (AJOL)

SIMULINK le comportement dynamique d'un système de pompage composé d'un générateur photovoltaïque, d'un onduleur, d'un moteur à induction et d'une pompe centrifuge. Le modèle global du système est bouclé : la sortie tension du GPV est ...

Élévation du niveau de la mer dans la zone côtière du delta du Nil

International Development Research Centre (IDRC) Digital Library (Canada)

l'eau, l'Institut d'études supérieures de l'Université d'Alexandrie et le Center for Development Services, une équipe de ... Selon un indice élaboré par l'équipe, les villes de Gamasa, ... La qualité du logement, des infrastructures et des services.

Lambeaux autofermants pour le traitement des brulures electriques du scalp par haut voltage

Science.gov (United States)

Hafidi, J.; El Mazouz, S.; El Mejatti, H.; Fejjal, N.; Gharib, N.E.; Abbassi, A.; Belmahi, A.M.

2011-01-01

Summary Les brûlures électriques par haut voltage sont responsables de gros dégâts tissulaires en immédiat et dans les jours suivant l’accident du fait de la chaleur importante dégagée par effet joule et de la thrombose microvasculaire évolutive. Les pertes de substances du scalp secondaires à ces brûlures nécessitent une couverture par lambeaux vu la destruction du périoste et du calvarium en regard. De juin 1997 à juin 2008, 15 patients ont été traités pour des pertes de substance du scalp secondaires à des brûlures électriques par haut voltage de diamètre allant de 8 à 11 cm et siégeant dans la région tonsurale. Ces patients ont été opérés dans la première semaine suivant l’accident. Les pertes de substance du scalp de taille moyenne secondaires à ces brûlures peuvent être couvertes per primam de façon fiable par des lambeaux locaux axialisés et multiples. Nous relatons l’expérience du Service de Chirurgie Plastique du Centre Hospitalier Universitaire Ibn-Sina, Rabat, Maroc, dans la gestion et la prise en charge de ces brûlures. PMID:22262963

L’infarctus du myocarde du jeune adulte -Analyse rétrospective des cas colligés au CHU de Dakar

Directory of Open Access Journals (Sweden)

Nobila Valentin Yameogo

2010-09-01

Full Text Available Les données relatives à l’infarctus du myocarde chez le jeune adulte sont rares en Afrique noir. Nous rapportons une série rétrospective de 14 cas d’infarctus du myocarde chez l’adulte jeune noir africain. Pour analyser les caractéristiques épidémiologiques, cliniques, électriques, échographiques, biologiques, thérapeutiques et évolutives de l’infarctus aigu du myocarde chez le jeune adulte nous avons étudié de manière rétrospective les dossiers médicaux d’une série consécutive des patients admis entre Janvier 2003 et Décembre 2008 pour prise en charge d’infarctus aigu du myocarde. Quatre-vingt quatre (84 cas d’infarctus du myocarde ont été pris en charge durant la période d’étude ,14 patients (16,6% avaient un âge inférieur ou égal à 40 ans. L’âge moyen était de 34 +ou-5ans (extrêmes 27ans et 40 ans. Les facteurs de risque cardio-vasculaire étaient dominés par le sexe masculin (n=11, la dyslipidémie (n=7 et le tabagisme par cigarette (n=6. La contraception orale était absente chez le 1/3 des patients. Le délai moyen d’admission était tardif (15 plus ou moins 4 heures. L’IDM était antérieur dans la moitié des cas. L’acide acétylsalicylique, les inhibiteurs de l’enzyme de conversion Les bétabloquants et les statines étaient les médicaments les plus prescrits. La thrombolyse et l’angioplastie étaient respectivement réalisées chez 3 patients et 0 patient. 4 cas d’insuffisance cardiaque, 2 cas de bloc atrio-ventriculaire complet et 1 cas de décès étaient les principales complications. L’infarctus du myocarde concerne également le sujet jeune noir africain. Les facteurs de risque sont essentiellement représentés par le sexe, la dyslipidémie, le tabagisme et la contraception orale.

Baisse de la transmission de la douve du foie dans le nord-est de la ...

International Development Research Centre (IDRC) Digital Library (Canada)

mortelle de cancer du foie liée à l'O. viverrini. Dans cer- taines régions, près de 85 % de la population est porteuse du parasite. Les villages du nord-est de la Thaïlande, où l'on raffole du poisson cru, ont des taux d'infection parmi les plus élevés du pays. Les personnes infectées peuvent porter le parasite adulte pendant ...

Survie au cancer du sein à Rabat (Maroc) 2005-2008

Science.gov (United States)

Mechita, Nada Bennani; Tazi, Mohammed Adnane; Er-Raki, Abdelouahed; Mrabet, Mustapha; Saadi, Asma; Benjaafar, Noureddine; Razine, Rachid

2016-01-01

Introduction Le cancer du sein représente un problème de santé publique au Maroc. L’objectif de ce travail était d’estimer le taux de survie au cancer du sein chez les patientes habitant la ville de Rabat. Méthodes Etude pronostique réalisée chez les patientes diagnostiquées pour cancer du sein de 2005 à 2008, habitant la ville de Rabat et enregistrées au registre des cancers de Rabat. La date d’inclusion dans l’étude correspondait à la date de confirmation histologique du cancer. L’estimation de la survie a été réalisée par la méthode de Kaplan Meier, et la comparaison entre les différentes classes d’une variable a été réalisée par le test de log rank. L’étude des facteurs associés à la survie a été effectuée par le modèle de Cox. Résultats Durant la période d’étude 628 cas de cancer du sein ont été collectés. Le pourcentage de décès était de 19,9%. La survie globale à un an était de 97,1%, elle était de 89,2% à 3 ans et de 80,6 % à 5 ans. En analyse multivariée la survie au cancer du sein était statistiquement moins bonne chez les patientes âgées de plus de 70 ans (p<0,001), ayantune grande taille de tumeur (p<0,001), un stade avancé d’adénopathies (p=0,007), présentant des métastases (p<0,001) et non traitées par hormonothérapie (p=0,002). Conclusion Une grande taille de la tumeur et la présence de métastases sont des facteurs de mauvais pronostic du cancer du sein d’où la nécessité de renforcer les programmes de dépistage. PMID:28292106

Pratiques foncières à l'ombre du droit : l'application du droit foncier urbain à Ziguinchor, Sénégal

NARCIS (Netherlands)

Hesseling, G.S.C.M.

1992-01-01

Dans cette étude l'auteur analyse les problèmes liés à l'application du droit foncier dans la ville de Ziguinchor, capitale de la région méridionale du Sénégal. Le titre de cet ouvrage évoque les pratiques foncières de tous les acteurs: l'État (composé de différents groupes, tendances, fractions) et

Protéger les mangroves du Cambodge | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

CRDI), un groupe de chercheurs du palier national et de la province du Koh Kong utilise une nouvelle approche pour gérer les ressources de la mangrove. Cette approche, qui fait appel à l'esprit d'initiative des membres de la ...

Rôle des coopératives dans le fonctionnement du bassin de collecte laitier du Tadla, Maroc

OpenAIRE

Le Gal , P.-Y.; Oudin , E.; Kuper , M.; Moulin , C.-H.; Sraïri , T.

2007-01-01

International audience; Le bassin de collecte laitier situé sur le périmètre du Tadla se structure autour d'une usine de transformation industrielle approvisionnée par une myriade de petits éleveurs. Cette atomisation de l'offre a rendu nécessaire la mise en place de coopératives de collecte chargées d'agréger l'offre et d'assurer la chaîne du froid au plus près des producteurs. De fait, ces coopératives jouent un rôle central d'intermédiaire dans la chaîne d'approvisionnement allant de l'eau...