WorldWideScience
 
 
1

Etudes Fractographiques De Fontes GS Traitees Par Trempe ...  

Science.gov (United States)

... que celle precedemment decrite, dont la formation peut etre causee par une trempabilite inadequate, un temps de maintien isotherme trop court ou ...

1987-01-01

2

A method for sorting irradiated substances through coloration  

International Nuclear Information System (INIS)

L'invention concerne un procede de triage de cristaux irradies. Ce procede non destructeur comporte l'irradiation des cristaux par un rayonnement ionisant pendant une duree et avec une intensite telles qu'il se forme des centres colores distinctifs dans les matieres contenant des ions aluminium. Les cristaux colores qui correspondent en teinte et en profondeur de couleur a des teneurs en aluminium en dehors de la teneur desiree peuvent etre separes. On peut isoler ainsi des matieres de quartz, de verre, de silicates exemptes d'aluminium dans un melange, ou bien on peut choisir des fractions de ces matieres, chacune contenant une teneur uniforme en aluminium.

3

LA GOUVERNANCE PAR L EVALUATION. LES QUASI MARCHES DANS LES SERVICES A DOMICILE  

British Library Electronic Table of Contents (United Kingdom)

RESUME: Cet article propose une tude du r le croissant que joue l valuation dans la gouvernance des services domicile en Europe. L introduction de quasi march s dans plusieurs pays europ ens va de pair avec un processus d autonomisation de la fonction d valuation qui devient un v ritable outil de r gulation de la concurrence. Une analyse compar e des situations en Belgique, France et Royaume Uni, tant de la demande que de l offre de services, met en vidence les tensions r currentes dans les objectifs de l valuation (qualit des services, ma trise des budgets sociaux, cr ation d emploi), la faible prise en compte de la qualit de l emploi ainsi que les limites des dispositifs standardis s d valuation au regard de la rh torique du libre choix de l usager (consommateur).

2010-01-01

4

Non-isothermal Smoluchowski-Poisson equations as a singular limit of the Navier-Stokes-Fourier-Poisson system  

British Library Electronic Table of Contents (United Kingdom)

ResumeLa convergence des solutions faibles du systeme de Navier-Stokes-Fourier-Poisson compressible avec un terme de frottement est etudiee dans la limite dun frottement infini, la loi de pression incluant, comme cas particulier, celle correspondant aux particules de Fermi-Dirac. La limite se trouve etre une solution faible dun systeme de Smoluchowski-Poisson non isotherme, la temperature ne dependant que de la variable temporelle et etant determinee par la conservation de lenergie totale.

2007-01-01

5

Dimensioning of the cooling system of the capacitors operating in a high frequency antenna, through a finite element method; Dimensionnement du systeme de refroidissement des condensateurs d'une antenne a haute frequence, par la methode des elements finis  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is the study of the heat transfer and of thermal behaviour of the HF (high frequency) components (in fact capacitors) of the ITER-proto-2005-FCI antenna. Preliminary results carried out with the Castem software show that it is possible to cool the hottest part of the antenna efficiently. A water flow (1 bar, 25 Celsius degrees) or an helium flow (10 bars, 50 Celsius degrees) permit to limit the maximal value of the temperature to 270 Celsius degrees. A second software Ansys has allowed the author to simulate capacitors with more complicated shapes. (A.C.)

2003-07-01

6

A sum rule approach to the violation of Dashen`s theorem; Une approache de la violation du theoreme de Dashen par les regles de somme  

Energy Technology Data Exchange (ETDEWEB)

A classic sum rule by Das et al. is extended to seven of the low-energy constant K{sub i}, introduced by Urech, which parameterizes electromagnetic corrections at chiral order O(e{sup 2}p{sup 2}). Using the spurion formalism, a simple convolution representation is shown to hold and the structure in terms of the chiral renormalization scale, QCD renormalization scale and the QED gauge parameter is displayed. The role of the resonances is studied as providing rational interpolants to relevant QCD n-point functions in the Euclidean domain. A variety of asymptotic constraints must be implemented which have phenomenological consequences. A current assumption concerning the dominance of the lowest-lying resonances is shown clearly to fail in some cases. (author)

1999-10-01

7

Water and oxygen transfer in a waste rock pile constructed by mixing layers; Transfert de l'eau et de l'oxygene dans une halde de steriles construite par entremelement par couches  

Energy Technology Data Exchange (ETDEWEB)

Acid mine drainage represents one of the most important environmental problem facing the mining industry. If the tailings contain sulphur, acid mine drainage will be generated as soon as the tailings are exposed to oxygen. In this paper, the authors discussed a technique for the storage of acid mine drainage generating tailings that delays and even eliminates the occurrence. It was suggested that tailings should be piled by incorporating, at regular intervals, compacted waste rock. Thermal convection and diffusion will prevent oxygen from reaching the tailings, and limit water circulation. The modelling of transfer processes (heat, water, oxygen) in a well known tailings dump, the Doyon Mine, was performed, and the results compared to the modelling where compacted waste rock had been incorporated at regular intervals. The results indicated that by remaining saturated, the layers acted as capillary barriers preventing oxygen from reaching the tailings, therefore reducing significantly ...

2000-07-01

8

Reduction of nitrogen oxides (NO{sub x}) production in a liquid fuel-oil diffusion flame by acoustic excitation; Reduction de la production des oxydes d`azote (NO{sub x}) dans une flamme de diffusion a fioul liquide par excitation acoustique  

Energy Technology Data Exchange (ETDEWEB)

The control of nitrogen oxides (NO{sub x}) emissions will become a major challenge in the forthcoming years, in the domain of automotive industry or industrial burners. Pulsed combustion offers an imaginative solution which does not affect the combustion efficiency. In this paper, the efficiency of this method is demonstrated using the burner of a 20 kW domestic boiler. The actuator is simply installed on the air intake. Two types of actuators have been tested successfully: a loudspeaker and a rotative valve. Both can produce 100 to 1000 Hz frequencies and can lead to a reduction of 20% of NO{sub x} emissions. The feasibility of the concept is also demonstrated on a 840 kW liquid fuel-oil burner. The mechanisms involved during an excitation are explained using the CH{sup *} radical imaging. Results show an important reorganization of the flow and of the flame structure. During each excitation cycle, an annular swirl occurs at the leading edge of the flame catching and develops during ...

1996-12-31

9

Environmental monitoring carried out by an association: the citizen watchdog of radioactivity in the environment; La surveillance de l'environnement exercee par une association: l'observatoire citoyen de la radioactivite dans l'environnement  

Energy Technology Data Exchange (ETDEWEB)

ACRO, a NGO equipped with a laboratory to measure radioactivity, runs the Citizen Watchdog of Radioactivity in the Environment. Involving many volunteers, it monitors regularly the French coast of the Channel and many rivers of the North half of France. It also makes investigations in other places. Such an action is aimed to supplement the official monitoring, not to replace it, in order to answer to the worries of the population. This monitoring shows that some radioelements, such as iodine 129, cobalt 60, tritium, etc. released in the environment by nuclear facilities can be detected on very large areas. Carbon 14 was detected up to almost 4 times the background in vegetables around the reprocessing plant of La Hague. ACRO also sits in many official committees to transmit the point of view of the populations exposed to the radioactive pollution. It is lobbying for a decrease of the release authorization, especially for the elements that are discharged in large quantity in the ...

2010-06-15

10

COURSE D'ORIENTATION  

CERN Multimedia

  Le Club d’Orientation du CERN vous propose de venir participer à la cinquième étape de la coupe d’automne Genevoise. Celle-ci sera organisée samedi 16 octobre par le club de Lausanne-Jorat (Canton de Vaud). Un fléchage depuis le Mont-sur-Lausanne en direction de Cugy vous conduira au Chalet à Gobet. 5 circuits seront proposés sur la carte Le Flon. Les inscriptions et les départs se feront sur place de 13h à 15h. Il est prévu une initiation à 13h30 pour les débutants. Les deux dernières étapes de la coupe d’automne sont prévues pour vendredi 22 octobre au soir et samedi 23 octobre après-midi. Le Club d’Orientation du CERN Informations sur le site http://cern.ch/club-orientation

2010-01-01

11

Natural ventilation of a room through a large external opening: calculation using a CFD code; Ventilation naturelle d`un local par une grande ouverture exterieure: calcul a l`aide d`un code de champ  

Energy Technology Data Exchange (ETDEWEB)

This paper is dedicated to the numerical study of natural ventilation in a room through a large external opening using the CFD code Fluent. Bidimensional numerical simulations are performed for wind speeds up to 5.55 m-s{sup -1} (20 km-h{sup -1}). We propose a two-step solution procedure with grid refinement. When combined with appropriate thermal boundary conditions, this technique appears very efficient at limiting local convergence problems. Through an analysis of the flow pattern in the cavity, we qualitatively explain those results and define a critical Archimedes number. Calculated air change rates are compared to values deduced from empirical correlations of the literature. Agreement is in general poor, which can be explained by the differences between the conditions of our simulations and those of the experiments that lead to those correlations. However, from our simulations, we derived very clear correlations between the air change coefficient and the Archimedes number. In the ...

1998-02-01

12

Torsion sur rate baladeuse chez l?enfant: ? propos d?un cas  

British Library Electronic Table of Contents (United Kingdom)

R?sum? La rate baladeuse est une anomalie rare chez l?enfant. Elle est souvent d?crite chez l?adulte, particuli?rement la femme enceinte. Elle est due ? un d?faut de fixit? anatomique de la rate avec les organes de voisinage. Ses manifestations cliniques sont variables, mais la complication la plus redoutable est la survenue d?une torsion du p?dicule spl?nique. Nous rapportons le cas d?une fille de 11 ans qui s?est pr?sent?e avec des douleurs abdominales aigu?s et des vomissements. Les examens radiologiques ont montr? une absence de la vascularisation spl?nique. ? l?exploration chirurgicale, on a d?couvert une torsion du p?dicule spl?nique avec une isch?mie tissulaire avanc?e. La rate ?tait d?pourvue d?attaches ligamentaires. La d?torsion n?a pas permis de sauvegarder la rate, et une spl?n...

2009-01-01

13

Update on the Role of Substantia Nigra Pars Reticulata in the Regulation of Seizures  

UK PubMed Central (United Kingdom)

The substantia nigra pars reticulata (SNR) represents an endogenous seizure suppressing system, which may be targeted to develop treatments for generalized or multifocal epilepsies. This review summarizes...Full Text Available

2006-05-01

14

Hydrogen control using igniters and pars during severe accidents  

International Nuclear Information System (INIS)

Full text of publication follows: The hydrogen mitigation system of 20 igniters and 6 PARs is installed to control the hydrogen in the containment during severe accidents and design basis accidents, respectively, in Shin-Wolsung 1 and 2 nuclear power plants. The igniters are primarily installed at the hydrogen source locations, and the PARs are installed in the open spaces. The PARs will maintain the hydrogen concentration within the containment atmosphere below the limit of 4 v/o in accordance with Regulatory Guide 1.7 during design basis accidents. The igniters will maintain the hydrogen concentration within the containment atmosphere below the limit of 10 v/o in accordance with 10CFR50.34(f) during severe accidents. In addition, the PARs can be used as a supplementary means to control the hydrogen concentration during severe accidents because of their inherent passive characteristics. This paper ...

2005-12-11

15

Simple calculation of daily photosynthesis by means of five photosynthesis-light equations  

Energy Technology Data Exchange (ETDEWEB)

The performance of five well-known photosynthesis-light equations is compared by presenting a wide range of solutions in the form of dimensionless nomographs for the case where photosynthetically available radiation (PAR) reduces exponentially down the water column and is distributed sinusoidally through the photoperiod. These provide a simple means of calculating daily photosynthesis at any depth (e.g. at a benthic layer), or through a water column, avoiding the need to perform complex integrations. An examination is made of the accuracy of common approximate methods for calculating daily photosynthesis, assuming constant PAR. For optically deep water a modification is proposed to Talling's planimetric solution, to enable daily photosynthesis to be calculated more accurately, yet simply, over the whole range of possible PAR values. The errors induced by approximating the daily PAR distribution ...

1992-12-01

16

FY06 PAR.indb - NASA  

Science.gov (United States)

Nov 15, 2006 ... Sick leave and other types of non-vested leave ... For FERS employees, NASA makes contributions of 10.7 percent to the defined benefit plan, ...

17

Dynamics of photosynthetic photon flux density (PPFD) and estimates in coastal northern California  

British Library Electronic Table of Contents (United Kingdom)

Plants require solar radiation for photosynthesis and their growth is directly related to the amount received, assuming that other environmental parameters are not limiting. Therefore, precise estimation of photosynthetically active radiation (PAR) is necessary to enhance overall accuracies of plant growth models. This study aimed to explore the PAR radiant flux in the San Francisco Bay Area of northern California. During the growing season (March through August) for 2?years 2007?2008, the on-site magnitudes of photosynthetic photon flux densities (PPFD) were investigated and then processed at both the hourly and daily time scales. Combined with global solar radiation (R S) and simulated extraterrestrial solar radiation, five PAR-related values were developed, i.e., flux density-based PAR ...

2011-01-01

18

P431 - Reaction hemolytique differee post-transfusionnelle chez une drepanocytaire  

British Library Electronic Table of Contents (United Kingdom)

Une enfant drepanocytaire homozygote SS de 14 ans (sans deficit en G6PD), non transfusee anterieurement, a une cholecystectomie pour lithiase decouverte a un bilan systematique. L'intervention est encadree de 2 transfusions de concentres erythrocytaires (CGR) phenotypes ABO Rh Kell, compatibilises. Quinze jours apres, elle presente une hemolyse aigue associant fievre, ictere, insuffisance renale tubulaire, hemoglobinurie et anemie profonde (Hb 3,6 g/dL). Les RAI deviennent positives avec, entre autres, un auto anticorps anti D suspecte, le test de Coombs direct est positif de type mixte. L'enfant n'est pas retransfusee, mais recoit 1 mg/kg/j de corticoides IV pendant 10 jours. L'hemoglobine retrouve sa valeur de base (9 g/dL) apres 15 jours. Un antigene RH1(D) partiel de type DAR est ulter...

2010-01-01

19

Ambassade Des Etats-Unis Kinshasa, Congo - Accueil  

Science.gov (United States)

sur la médiatisation des élections Il s'est ouverte le 16 septembre 2011 à Matadi dans le Bas-Congo une formation sur la médiatisation des questions électorales,...

2011-10-13

20

Seismic analysis of the Par Pond Dam: Study of slope failure and liquefaction. Technical evaluation report  

Energy Technology Data Exchange (ETDEWEB)

Stability concerns of the Par Pond Dam, an embankment structure in the Savannah River Site complex, resulted in a comprehensive evaluation of the state of its integrity. Specifically, excessive seepage through the embankment, slope failure due to an earthquake event as well as liquefaction potential of the embankment and the foundation are addressed and the potential of failure is evaluated. Lastly, remedial benefits of the addition of a berm structure are also assessed.

1994-07-01

 
 
 
 
21

Metallic aggregate synthesis by radiolysis of simple or complex salt aqueous solutions. Study by electron microscope of aggregate grafting on carbon membranes  

International Nuclear Information System (INIS)

French ... Title Synthese d'agregats metalliques par radiolyse de solutions aqueuses de sels simples ou complexes. Etude par M. E. du greffage des agregats sur membranes de carbone.

1987-05-20

22

Determination of ash in coal by X-ray backscattering and X-ray fluorescence analysis and apparatus by the PAR company  

International Nuclear Information System (INIS)

The basic principles of determination of the ash content of coal by the title methods are outlined. A brief technical characteristic of the ash meters and radionuclide X-ray fluorescence analyzers manufactured by the PAR company is presented. (Z.S.). 4 figs., 7 refs.

1993-01-01

23

Blockade of androgen receptors is sufficient to alter the sexual differentiation of the substantia nigra pars reticulata seizure-controlling network  

UK PubMed Central (United Kingdom)

The substantia nigra pars reticulata (SNR) controls seizures in a sex-specific manner. At postnatal day 15 (P15), SNR infusion of GABAA receptor agonist muscimol have proconvulsant...Full Text Available

2008-03-01

24

Extraction of copper-, nickel-, zinc- and cadmium complexes with 4-(2-pyridilazo)-resorcin and 2-aminopyridine  

International Nuclear Information System (INIS)

Extraction of copper-, nickel-, zinc- and cadmium complexes with 4-(2 pyridilazo)-resorcin (PAR) is studied in the presence of 2-aminopyridine (Am). Maximum optical densities of the extracts are attained at pH=7.5-8.0; 6.0-7.0; 6.5-7.0 and 7.0-8.0, respectively. The ratio of components in the complexes extractable by chloroform was defined by the method of isomolar series and equilibrium shift. It is established that nickel and copper are extracted to the organic phase as the NiAm(PAR)_2 and CuAmPAR complexes, and, in the case of zinc and cadmium, complexes of different composition are extracted, for example Zn(Am)_2PAR and ZnAm(PAR)_2. The light absorption spectra are studied and molar extinction coefficients of complex extracts are determined at lambdasub(max). It is shown that the general low of light absorption is observed within a sufficiently wide range of concentrations for ...

1984-01-01

25

Mixed-ligand complexes of scandium with 4-(2-pyridylazo)resorcinol and monocarboxylic acids  

International Nuclear Information System (INIS)

Scandium reacts with 4-(2-pyridylazo)resorcinol in the presence of monocarboxylic acids (X) to form mixed-ligand complexes with a Sc:PAR:x ratio of 1:2:2. The chemical nature of this interaction has been established, and the extraction of these mixed-ligand complexes has also been investigated; stability constants and molar extinction coefficients have been calculated. The values of the latter decrease in the order CH_3COOH > CH_2ClCOOH > CCl_3COOH. The formation and extraction of mixed-ligand complexes in Sc-PAR-HX systems make it possible to increase the sensitivity and selectivity of scandium determination in comparison with the use of the Sc-PAR mono-ligand complex.

1987-09-01

26

Management of nucleus loss into the vitreous: long term follow up in 63 patients  

UK PubMed Central (United Kingdom)

Background:The aim of present study is to determine the long-term results of patients who undergo pars plana vitrectomy after retained nucleus into the vitreous.Setting:Service...Full Text Available

2007-12-01

27

K Kiosk - NIH Extramural Training: Information about NIH Career...  

Science.gov (United States)

Established Investigators (K18) (PAR-09-090) NIH: Career Enhancement Award for Stem Cell Research (K18) (PA-09-110) NIDCD: NIDCD Research Career Enhancement Award for Established...

2011-10-01

28

Air shifting diffusion; Diffusion d'air par deplacement  

Energy Technology Data Exchange (ETDEWEB)

The technique of air diffusion by shifting presents several advantages in terms of thermal comfort, indoor air quality and energy conservation. This book presents the principle, dimensioning, and implementation of air shifting diffusion systems. (J.S.)

2001-07-01

29

Determination of ash content in coal by means of backscattered X-ray radiation and X-ray fluorescence analysis, and devices manufactured by the PAR company  

Energy Technology Data Exchange (ETDEWEB)

Discusses methods for determining ash content in coal using backscattering in X-ray fluorescence. The following aspects are evaluated: principle of ash content determination, energy sources, factors that influence measurement accuracy, reliability. Types of X-ray fluorescence analyzers developed in Czechoslovakia and manufactured in the Czech Republic are comparatively evaluated. Operation of the RPM 113.1 radionuclide X-ray fluorescence analyzer developed by the PAR company and used for measuring ash content in coal and coal calorific value is discussed. 7 refs.

1993-09-01

30

Steatohepatite non alcoolique chez une adolescente obese : une biopsie hepatique discutable  

British Library Electronic Table of Contents (United Kingdom)

The growing epidemic of juvenile obesity has prompted pediatricians to investigate obesity-related conditions in obese teenagers. We report a clinical case of severe hepatic fibrosis in an adolescent with severe and recent obesity. Because of elevated serum aminotransferase levels, abnormal hepatic ultrasonography and insulin resistance (impaired glucose tolerance), we suspected nonalcoholic steatohepatitis (NASH). Disease activity and fibrosis were confirmed on liver biopsy. Considering the risk of progression toward cirrhosis and its complications, and the pathological liver lesions, we started long-term medical monitoring and drug therapy to control weight loss. At present, although biopsy is the only validated way to establish the diagnosis of NASH, there is no consensus on its indicat...

2011-01-01

31

Fuel oils suppliers. A business always in movement; Distributeurs de fioul domestique. Une profession toujours en marche  

Energy Technology Data Exchange (ETDEWEB)

This economic analysis of the fuel oils market deals with the fiscality of the product and the place of the traditional suppliers facing the introduction of the supermarkets in the distribution sector. Facing the fiscality and the competition, the fuel oils suppliers stay confident. (A.L.B.)

2001-12-01

32

The management of wounds following primary lower limb arthroplasty: a prospective, randomised study comparing hydrofibre and central pad dressings  

British Library Electronic Table of Contents (United Kingdom)

Abuzakuk T, Coward P, Shenava Y, Kumar VS, Skinner JA. The management of wounds following primary lower limb arthroplasty: a prospective, randomised study comparing hydrofibre and central pad dressings. Pris en charge des plaies apres arthroplastie primaire du member inferieur: une etude randomisee prospective comparant hydrofibre et pansements central pad La prise en charge des plaies apres arthroplastie du member inferieur n'a pas fait l'objet de recherches approfondies, essentiellement car ces plaies cicatrisent habituellement sans complications. Cependant, lorsque des implants prothetiques sont utilizes, les serieux problemes de plaies peuvent devenir desastreux. Nous rapportons les resultants d'une etude prospective, randomisee, controlee comparant un hydrofibre et un pasnement centra...

2006-01-01

33

Natural attenuation in soils: an alternative to usual remedial methods: A case study of its application for diesel contamination; L`attenuation naturelle dans les sols: une alternative aux methodes usuelles de restauration: etude de cas applicable a une contamination en diesel  

Energy Technology Data Exchange (ETDEWEB)

Various pollution abatement measures available to combat oil spills were reviewed with emphasis on biodegradation. Microorganisms naturally found in soils and groundwater can efficiently degrade a variety of organic contaminants. For certain sites, local temperature allows the microorganisms to reduce the contaminant concentrations without human intervention. In April 1994, a diesel fuel leak was found at a telecommunication station located in a park. The leak had already contaminated the surrounding soil. The first step of the clean-up procedure was to excavate the contaminated soil, followed by an evaluation to determine the extent of the remaining contamination. It was concluded that by using natural attenuation the deforestation of the remaining affected area could be prevented. In this instance, the natural attenuation process is expected to take five years for completion. 4 refs., 1 tab., 1 fig.

1998-04-01

34

Surveillance and control. A new edition of the BETCGB guidebook for the control of dams in exploitation; Surveillance et controle. Une nouvelle edition du guide du BETCGB pour le controle des barrages en exploitation  

Energy Technology Data Exchange (ETDEWEB)

The French office for technical studies and control of big dams (BETCGB), has recently reedited the `guidebook for the control of dams in exploitation`. The aim of this document is to provide to the regional directions of industry, research and environment (DRIRE) a methodological help for their control actions of hydroelectric dams granted for exploitation. It comprises 6 chapters dealing with: the different type of dams, the inspection, the surveillance, the floods evacuation, the flood instructions, and the particular emergency plans. (J.S.)

1998-12-31

35

Interest of a two-dimensional matrix of detectors for the quality control of beams in static or dynamic mode; Interet d'une matrice bidimensionnelle de detecteurs pour le controle de qualite des faisceaux en mode statique ou dynamique  

Energy Technology Data Exchange (ETDEWEB)

A 2D matrix allows a fairly rapid verification of irradiation parameters transferred on computer processing equipment without expanding the dosimetry means to implement. Associated to 'Multicheck and Verisoft' software it will handle some of the regulatory recommendations of the A.F.S.S.A.P.S. for quality control of accelerators and ensure the traceability of testing carried out. (N.C.)

2007-11-15

36

Transforming growth factor-? signaling mediates hypoxia-induced pulmonary arterial remodeling and inhibition of alveolar development in newborn mouse lung  

UK PubMed Central (United Kingdom)

Hypoxia causes abnormal neonatal pulmonary artery remodeling (PAR) and inhibition of alveolar development (IAD). Transforming growth factor (TGF)-β is an important regulator of lung development...Full Text Available

2008-07-01

37

The tele-robotics system MT200-TAO replaces mechanical tele-manipulators in COGEMA/AREVA-La Hague hot cells  

International Nuclear Information System (INIS)

We present here for the first time the tele-robotics system for hot-cells MT200-TAO (TAO stands for Teleoperation Assistee par Ordinateur or Computer Assisted Tele-robotics), able to replace a conventional telescopic medium tele-manipulator (extension 4 m; capacity 20 kg). The system is currently under evaluation in COGEMA/AREVA- La Hague hot-cells. (authors)

2005-12-11

38

MMP-9 Gene Ablation and TIMP-4 Mitigate PAR-1-Mediated Cardiomyocyte Dysfunction: A Plausible Role of Dicer and miRNA  

UK PubMed Central (United Kingdom)

Although matrix metalloproteinase-9 (MMP-9) is involved in cardiomyocytes contractility dysfunction, tissue inhibitor of metalloproteinase-4 (TIMP-4) mitigates the effect of MMP-9, and proteinase-activated...Full Text Available

2010-07-01

40

Irradiation by carbon ions?: why? How?; Irradiation par ions carbone: pourquoi? Comment?  

Energy Technology Data Exchange (ETDEWEB)

The interest of irradiation by carbon ions is in the fact that the carbon ions leave all their energy to a determined depth. ( phenomenon known under the name of Bragg peak)This high diffusion in tissue gives an RBE particularly high. The indications of this therapy are chordomas, and chondrosarcomas of the skull base, some cyst adenoid carcinomas, pulmonary cancer, sarcomas, hepato carcinomas, melanomas. In the light of results in term of efficiency, the place of irradiation by carbon ions should widen. (N.C.)

2006-11-15

 
 
 
 
41

An approach to rehabilitation objectives. Example of hydrocarbon polluted sites; Approche des objectifs de rehabilitation. Exemple des sites pollues par des hydrocarbures  

Energy Technology Data Exchange (ETDEWEB)

The UFIP (French Petroleum Industry Association) studies concerning polluted sites and soils and their rehabilitation are presented: characterization of the admissible maximum fuel or gas oil content in the ground, the issue of time effects, and the risks it may induce for public health; study on the various pollutant impacts on the environment (underground waters, biotope...); approach to the development of a dynamical model describing these phenomena and their influence on man, in order to derive consistent and reasonable decontamination objectives

1996-12-31

42

Use of semi-detailed kinetic schemes for a study of the temperature dependence in the reforming of fuels without catalyst; L'utilisation de schemas cinetiques semi-detailles pour une etude de l'influence de la temperature dans le reformage de combustibles sans catalyseur  

Energy Technology Data Exchange (ETDEWEB)

In order to avoid the use of catalysts in the process of auto-thermal reforming, it is possible to adopt a running at high temperature. In this study are presented the results of simulations of an auto-thermal/recuperator hybrid reforming system; these results are obtained with the oxidation model of alkanes developed by Ranzi and Faravelli. An isothermal configuration at high temperature improves the hydrogen yield and avoids the formation of soots. The analysis of the powers to be furnished to assure such an experimental mode, and the global approach of the fuel cell system show that the management of the heat exchanges is a key parameter in this process. (O.M.)

2000-07-01

43

Surface passivation: a new way to reduce self-output in LiMn{sub 2}O{sub 4}/Li lithium ion rechargeable batteries; Passivation de surface: une nouvelle voie pour reduire l`autodecharge dans les batteries rechargeables a ions lithium LiMn{sub 2}O{sub 4}/Li  

Energy Technology Data Exchange (ETDEWEB)

The new generation of performing rechargeable lithium-ion batteries (``rocking-chair``-type) are penalized by important self-output phenomena linked with the use of highly oxidizing positive electrodes. In order to limit this problem in LiMn{sub 2}O{sub 4}/C batteries, two different passivation techniques were used in order to limit the surface contact between the positive electrode and the electrolyte. Thanks to these treatments, a significant reduction of the percentage of irreversible capacity losses is effectively observed. (J.S.) 3 refs.

1996-12-31

44

Subaqueous deposition of reactive mine tailings in an open trench; Deposition subaquatique de residus miniers reactifs dans une fosse a ciel ouvert  

Energy Technology Data Exchange (ETDEWEB)

This poster presentation gave an overview of the subaqueous deposition of reactive mine tailings in the open trench Don Rouyn, located near Rouyn-Noranda, Quebec. The author began by providing a brief background of subaqueous mine tailing storage, and discussed the interest of the Don Rouyn trench. The site was described according to geomorphological and geological aspects. The hydrology conditions existing at the site were mentioned, and the results of the hydrology analysis performed were indicated. Close monitoring of the situation was maintained, and the chemical and physical stability of the tailings were evaluated. The conditions that prevailed both before and after the flooding of the site were explained. Water quality is being monitored, and the results obtained at this site might be used at other locations. 40 figs.

2000-07-01

45

Impact of the regulation on information about new substances derived from the Canadian Environmental Protection Act (CEPA) on the application of biotechnological treatment of AMD : a case study; Impact du reglement sur les renseignements concernant les substances nouvelles de la LCPE sur l'application d'une biotechnologie de traitement du DMA : etude de cas  

Energy Technology Data Exchange (ETDEWEB)

This poster presentation covered a number of issues related to the new regulations concerning information on new substances derived from the Canadian Environmental Protection Act (CEPA). The authors described the background, and the objectives of the research project. A brief overview of the Acid Mine Drainage (AMD) process was provided, as well as the sulphate reduction process. The general methodology was explained, and the results of the bioactivation presented. The process followed for the bioaugmentation and the results obtained were presented. The regulations concerning information on new substances derived from the CEPA were described. The authors then presented their conclusions and perspectives. 26 figs.

2000-07-01

46

Evaporation in forced convection of an Ostwaldian permanent laminar film flowing over an isothermal inclined plane surface; Evaporation en convection forcee d'un film liquide mince ostwaldien ruisselant en regime laminaire permanent sur une surface plane isotherme et inclinee  

Energy Technology Data Exchange (ETDEWEB)

The authors study, in forced convection, the evaporation of an Ostwaldian film flowing over an isothermal inclined plane surface to determine the influence of the behaviour index of the liquid on the dynamic and thermal characteristics of liquid-air system. The liquid flow is considered partially two-dimensional whereas for the air it is two-dimensional. The coupled equations with the interfacial conditions are solved using a fully implicit finite differences method. From the study, it appears that the behaviour index influences considerably the transfers which are more important for pseudo-plastic liquids than for dilatant ones. (authors)

2003-12-01

47

Development of a petrographic technique for the quality control of concrete mixes used in mines. Final report; Mise au point d`une technique petrographique pour le controle de qualite des betons miniers. Rapport final  

Energy Technology Data Exchange (ETDEWEB)

Petrographical analysis is a microscopical analytical tool which allows definition of the exact nature of the components of different concrete mixes, as well as definition of internal structures and alteration processes. In order to improve the precision and the swiftness of the petrographical analysis, an automated image analysis system has been developed. In the next stage of this study, which consisted in the testing of new concrete mixes containing fluidised bed ashes, petrography has been used, not only to identify the nature of the mix components, but also assess the behaviour of these new concrete mixes when exposed to aggressive conditions.

1997-11-01

48

Constitution of a centralised data base for the internal quality control in radiotherapy; Constitution d'une base de donnees centralisee pour le controle de qualite interne en radiotherapie  

Energy Technology Data Exchange (ETDEWEB)

The objective of this project was to implement a centralised data base of internal quality control in radiotherapy according to the criteria of the decree of A.f.s.s.a.p.s. (French agency of sanitary safety of health products on 27 july 2007, about the internal quality control of external radiotherapy facilities. The software on one year meets the objectives: compliance by comparison with A.f.s.s.a.p.s. criteria but particularly optimization of the centralisation and analysis of the internal quality controls. (N.C.)

2009-10-15

49

Air conditioning in the industry. A solution to production constraints; Clim dans l`industrie. Une solution aux contraintes de production  

Energy Technology Data Exchange (ETDEWEB)

Industrial premises bear more and more important thermal constraints which can commonly reach 150 W/m{sup 2} and more. The reason is the general development of automation and automatic devices and the better thermal insulation of buildings. Production quality requires also more and more strict ambient conditions (temperature, humidity, air quality, air flow etc..). Thus, the air-conditioning market in the industrial sector is more linked to economic factors such as productivity and profit than to thermal comfort of workers. However, the air-conditioning potentialities in the industrial sector remains under-exploited in France. This paper analyzes the reasons of this situation in terms of investments and equipments. (J.S.)

1997-09-01

50

A new approach of the understanding of sulfur dioxide reduction in non-aqueous solvent; Une nouvelle approche de la comprehension de la reduction du dioxyde de soufre en solvant non aqueux  

Energy Technology Data Exchange (ETDEWEB)

The study of SO{sub 2} reduction in non-aqueous solvent can help to understand the functioning of Li/SO{sub 2} batteries and to find a simpler way for the synthesis of Li{sub 2}S{sub 2}O{sub 4} dithionite. This paper presents the results of electrochemical studies (cycle volt-amperometry in semi-infinite and thin film diffusion conditions, visible spectro-electrochemistry) and spectroscopic studies (UV, visible and RPE) performed on SO{sub 2} solutions. A mechanism of SO{sub 2} reduction is proposed and discussed. (J.S.) 18 refs.

1996-12-31

51

Calibration and analysis of soil carbon efflux estimates with closed chambers at Forsmark and Laxemar  

International Nuclear Information System (INIS)

The Forsmark and the Laxemar investigation areas are examined by the Swedish Nuclear Fuel and Waste Management Co. for a possible construction of a deep repository for nuclear waste. In the case of a future leakage of waste, the radioactive isotopes could end up in the ecosystems above the repository. The fate of the radionuclides and their possible radiological impacts are then highly determined by ecosystem carbon cycling. An important part of the carbon cycling is the soil carbon effluxes, and in the investigation areas soil carbon effluxes have been examined with the closed chamber technique. This paper is divided into two parts. Firstly, there were problems with the equipment measuring the soil carbon dioxide efflux, and the first part is a description of the problem, how it was corrected and its possible causes. The second part is a manual in how to analyse data and calculate annual estimates of soil carbon efflux. The field measurement by the EGM-4 is just an occasional estimate ...

2007-01-01

52

The east-European energy situation. Slowing of economic growth cuts down on energy demand. Zur Energie-Situation in Osteuropa. Wachstumseinbussen mindern Energiebedarf  

Energy Technology Data Exchange (ETDEWEB)

The economic development of eastern Europe was associated during the last 15 years with the following average annual increases in energy consumption: Approximately 1% in the sectors industry, building and transport, almost 7% in the farming sector, approximately 3% in households, and nearly 4% in the municipal sector. This trend will not continue. As the economic system shifts from centrally planned to free economy and as the previously secluded economy is forced to face world market conditions as well as changed pars of exchange and conditions of payment, it not only experiences a transitory, sharp dip of economic growth in general but, in particular, drastic structural changes. - While there is to be expected, on the whole a slump in national economic growth, in tradiational branches of industry (e.g., metallurgy, the chemicals and textile industry) as well as in farming, such sectors as the service industry and small trade are expanding. (orig./UA).

1991-10-01

53

Study of oxygen diffusion in YBaCuO by isothermal internal friction. Etude par frottement interieur isotherme de la diffusion de l'oxygene dans YBaCuO  

Energy Technology Data Exchange (ETDEWEB)

The elastic behaviour of YBaCuO specimens has been studied by very low-frequency isothermal internal-friction measurements. A relaxation peak is observed which is attributed to oxygen atom jumps, between A(1/2 0 0) and B(0 1/2 0) sites, in the CuO planes of the orthorhombic phase. A limit relaxation time {tau}{sub 0}, 2.6 {center dot} 10{sup -15}s, and an activation energy, 1.3eV, have been obtained from the shift of the maximum damping frequency observed when the measurement temperature is changed. The proposed values for the limit relaxation time and the activation energy are in good agreement with those previously proposed in the literature.

1992-02-07

54

Relationship between the electronic structure of passive films and the susceptibility to pitting corrosion of stainless steels; Relations entre la structure electronique des films de passivation formes sur les aciers inoxydables et la susceptibilite de ces derniers a la corrosion par piqures  

Energy Technology Data Exchange (ETDEWEB)

The passive films formed on 316L stainless steel in various NaCl solutions have been investigated by capacitance measurements (Mott-Schottky). Pitting parameters have been determined using the galvano-kinetic polarisation method. The obtained results reveal the existence of a shallow and a deep donor level localised in the band gap of the semiconducting oxide film. These energy levels are due to iron ions in the tetrahedral and octahedral positions. It also appears that the participation of the deep donor level effects the electric field. The study developed allows us to compare characteristic parameters of the electronic structure of the passive film to those related to pitting susceptibility. (authors) 25 refs.

1998-04-01

55

Reduction of the greenhouse effect by geological mineral in-situ sequestration of CO{sub 2} in basic rocks: bibliographic synthesis and possibilities in France. Final report; Reduction de l'effet de serre par sequestration geologique minerale in-situ de CO{sub 2} au sein de roches basiques: synthese bibliographique et revue des potentialites en France. Rapport final  

Energy Technology Data Exchange (ETDEWEB)

The report constitutes a first bibliographic study defining the environments the most adapted to the geological mineral in-situ sequestration of CO{sub 2}. For each environment the lithology and the rocks permeability and porosity are analyzed. Thus the possible rocks and deposits in France are presented. (A.L.B.)

2004-07-01

56

Photosynthesis responses to various soil moisture in leaves of Wisteria sinensis  

British Library Electronic Table of Contents (United Kingdom)

A study was conducted to determine the fitting soil moisture for the normal growth of two-year-old W. sinensis (Sims) Sweets by using gas exchange technique. Remarkable threshold values of net photosynthetic rate (Pn), transpiration rate (Tr) and water use efficiency (WUE) were observed in the W. sinensis leaves treated by various soil moisture and photosynthetic available radiation (PAR). The fitting soil moisture for maintaining a high level of Pn and WUE was in range of 15.3%?26.5% of volumetric water content (VWC), of which the optimal VWC was 23.3%. Under the condition of fitting soil moisture, the light saturation point of leaves occurred at above 800?mol?m?2?s?1, whereas under the condition of water deficiency (VWC, 11.9% and 8.2%) or oversaturation (VWC, 26.5%), the light saturatio...

2007-01-01

57

Neural network and noise injection for the modeling of ozone pollution; Reseau de neurones et injection de bruit pour la modelisation de la pollution par l'ozone  

Energy Technology Data Exchange (ETDEWEB)

This study has been carried out in the framework of a collaboration between the laboratory of processes automation (LAP, Caen (France)), and Air Com, a monitoring network for the prevention of atmospheric pollution in Basse-Normandie. It aims at obtaining a medium and long term forecast of the ozone level above the Caen city. The expected goal is to foresee the pollution peaks exceeding the warning thresholds, but the rareness of such events make them more difficult to predict. In order to solve this kind of problem, a neural modeling method combined with a noise injection technique has been implemented in order to obtain a sufficiently performing model over the whole domain of operation. (J.S.)

2001-07-01

58

Linac automated beam phase control system.  

Energy Technology Data Exchange (ETDEWEB)

Adjustment of the rf phase in a linear accelerator is crucial for maintaining optimal performance. If phasing is incorrect, the beam will in general have an energy error and increased energy spread. While an energy error can be readily detected and corrected using position readings from beam position monitors at dispersion locations, this is not helpful for correcting energy spread in a system with many possible phase errors. Uncorrected energy spread results in poor capture efficiency in downstream accelerators, such as the Advanced Photon Source's (APS's) particle accumulator ring (PAR) or booster synchrotron. To address this issue, APS has implemented beam-to-rf phase detectors in the linac, along with software for automatic correction of phase errors. We discuss the design, implementation, and performance of these detectors and how they improved APS top-up operations.

2006-01-01

59

Innovating methodologies brought into operation by Framatome for the Phenix control; Methodologies innovatrices mises en oeuvre par Framatome pour le controle de Phenix  

Energy Technology Data Exchange (ETDEWEB)

The renovation programme of the Phenix nuclear power plant (fast neutrons reactor situated at Marcoule) has for objective to ensure the reactor operation lengthening. In this frame, expertise and monitoring operation in situ of materials have been started. The presence of sodium and a temperature at the cold breakdown of the primary circuit between 150 and 180 degrees (Celsius) imply, for fast reactors, very special conditions. In this context, Framatome has realised three intervening in the area of nondestructive testing: the inspection of the cone-shaped support ring, the monitoring of the upper part of the primary vessel and the monitoring of the intermediary exchanger equipment. (N.C.)

2000-06-01

60

From Bargmann's superselection rule to quantum Newtonian spacetime  

CERN Document Server

Bargmann's superselection rule, which forbids the existence of superpositions of states with different mass and, therefore, implies the impossibility of describing unstable particles in non-relativistic quantum mechanics, arises as a consequence of demanding Galilean covariance of Schr\\"odinger's equation. However, the usual Galilean transformations inadequately describe the symmetries of non-relativistic quantum mechanics since they fail to take into account relativistic time contraction effects which can produce non-relativistic phases in the wavefunction. In this paper we describe the incompatibility between Bargmann's rule and Lorentz transformations in the low-velocities limit, we analyze its classical origin and we show that the Extended Galilei group characterizes better the symmetries of the theory. Furthermore, we claim that a proper description of non-relativistic quantum mechanics requires a modification of the notion of spacetime in the corresponding limit, which is ...

2011-01-01

 
 
 
 
61

Evapotranspiration estimation using the Landsat-5 Thematic Mapper image over the Gyungan watershed in Korea  

British Library Electronic Table of Contents (United Kingdom)

Even if there have been efforts to validate remote-sensing-based energy balance models, which provide evapotranspiration (ET) maps over a large spatial scale, few studies have been conducted to validate their performance in Korea. In this study, surface energy balance fluxes including ET were estimated and inter-compared with two different models using the Landsat-5 Thematic Mapper (TM) image over a watershed scale in Korea. While there were larger spatial discrepancies for net radiation, soil heat and sensible heat fluxes on a pixel-by-pixel basis between the two models, relatively smaller spatial discrepancies for the latent heat flux and daily ET were detected. The spatial discrepancies for the daily ET were larger in low topography and dense vegetation ranges. Despite the different par...

2011-01-01

62

Evaluation of the concept SPEOS applied to the exploitation of industrial waste heat stored in an underground seasonal storage; Prospection et evaluation du potentiel d`application du concept SPEOS a la valorisation des rejets thermiques industriels par stockage saisonnier souterrain  

Energy Technology Data Exchange (ETDEWEB)

SPEOS takes advantage of a geological situation which apparently does not occur much in Switzerland. The SPEOS pilot installation, which was erected in 1982, is designed for the supply of heat for about 500 persons. In the course of 10 cycles, the possibilities and limits of the seasonal heat storage were displayed. It was demonstrated that large quantities of heat with temperatures of up to 75 C can be stored in an aquifer. The behaviour of such a storage can be predicted with sufficient accuracy with mathematical models. (author) 12 refs.

1993-09-01

63

Eddy current probe development based on a magnetic sensor array; Developpement d'un imageur magnetique pour le controle non destructif par courants de Foucault  

Energy Technology Data Exchange (ETDEWEB)

This research deals with in the study of the use of innovating magnetic sensors in eddy current non destructive inspection. The author reports an analysis survey of magnetic sensor performances. This survey enables the selection of magnetic sensor technologies used in non destructive inspection. He presents the state-of-the-art of eddy current probes exploiting the qualities of innovating magnetic sensors, and describes the methods enabling the use of these magnetic sensors in non destructive testing. Two main applications of innovating magnetic sensors are identified: the detection of very small defects by means of magneto-resistive sensors, and the detection of deep defects by means of giant magneto-impedances. Based on the use of modelling, optimization, signal processing tools, probes are manufactured for these both applications.

2007-06-15

64

Differences in morphology, gas exchange and root hydraulic conductance before planting in Pinus canariensis seedlings growing under different fertilization and light regimes  

British Library Electronic Table of Contents (United Kingdom)

As the main forestry species in the Canary Islands (Spain), Pinus canariensis is frequently used in afforestation programs. Several nursery techniques are commonly employed to modify its morphology and physiology with the aim of improving post-planting survival and growth. In this work, we studied how fertilization and light regime treatments applied during the nursery period modify biomass allocation patterns and produce effects in gas exchange and root hydraulic conductance. Seedlings were grown for a 6-month period in the nursery under two light regimes (full sunlight and 40% PAR reduction), and three fertilization levels were applied in each light regime. Morphology, biomass allocation patterns, leaf gas exchange and hydraulic conductance of the whole root system were evaluated. Fertil...

2010-01-01

65

A new method for quantifiable and controlled dosage of particulate matter for in vitro studies: The electrostatic particulate dosage and exposure system (EPDExS)  

British Library Electronic Table of Contents (United Kingdom)

An exposure chamber is described for the quantifiable addition of fine and ultrafine aerosol particulate matter directly to cells and used to demonstrate the in vitro cytotoxicity of fine 1,4-naphthoquinone particles to murine lung epithelial cells. The electrostatic particulate dosage and exposure system (EPDExS) operates on the principle of electrostatic precipitation and is shown to deposit fine and ultrafine aerosol particles directly to cells with 100% efficiency for particle diameters in the range of 40-530nm. This range is not limited by the EPDExS, but rather by the aerosolization method used for this study. Numbers of particles deposited onto the cells are counted with a condensation particle counter, negating any need to calculate or estimate particle exposure. The process of par...

2008-01-01

66

The electron diffraction: a prime technique to characterize the behaviour of the Li{sub 1-x}C{sub y} / Li{sub x}NiO{sub 2} positive electrode; La diffraction electronique: une technique de choix pour caracteriser le comportement de l`electrode positive Li{sub 1-x}C{sub y} / Li{sub x}NiO{sub 2}  

Energy Technology Data Exchange (ETDEWEB)

LiNiO{sub 2} is one of the most promising material for positive electrodes of lithium-ion batteries. However, its behaviour during cycling and the existence of several phase transitions induced by the lithium ions de-intercalation process has not been explained so far. A transition electron microscopy study of various Li{sub x}NiO{sub 2} (0.25

1996-12-31

67

Study on the application of a geothermal heat pump; Etude sur l`application d`une pompe a chaleur geothermique  

Energy Technology Data Exchange (ETDEWEB)

The heating system of the `Centre integre de mecanique industrielle de la Chaudiere`, in Saint-Georges, Quebec, is based on a solar wall and a geothermal heat pump with a glycol/water mixture circulating in 44 wells that are 100 m deep. With installation costs below $25 per sq.m, more than 85 per cent of the heating needs of the 9500 sq.m centre were supplied by geothermal power. The geothermal heat pump is composed of a well field and two 211-kW cooling units, each equipped with four coiled compressors. In winter, heat is pumped from the earth and in summer, a heat exchanger with control valves allows to heat to be dumped back into the earth. The monitoring and simulation of the system proved its efficiency, considering the climatic conditions in Quebec. The annual consumption of geothermal heating is 0.146 GJ per sq.m, which is very low compared to the consumption of electric heating (0.286 GJ per sq.m) or oil heating (0.419 GJ per sq.m). 4 figs., 1 tab.

1996-12-01

68

Recycling of red mud waste for use as a catalyst for eliminating volatile organic compounds; Recyclage d'un dechet, une boue rouge, comme catalyseur pour l'elimination des composes organiques volatils  

Energy Technology Data Exchange (ETDEWEB)

Red mud is a waste product of the aluminium refining industry. It is composed of aluminium hydroxide and iron oxide. This study examined the feasibility of using red mud as a catalyst to eliminate volatile organic compounds in atmospheric pollutants. Volatile organic compounds can be eliminated by thermal oxidation between 600 and 1100 degrees C. However, the oxidation of volatile organic compounds can also be accomplished at lower temperatures (200 to 450 degrees C) if a catalyst is present. Currently, the low temperature destruction of volatile organic compounds is not widespread because of the difficulty in deactivating the catalyst. In this study, red mud was calcined in air at 500 degrees C. Under such conditions, the red mud converts to aluminium oxide and iron oxide. These 2 oxides are active and are carbon dioxide selective in the oxidation of volatile organic compounds. The study showed that red mud can be used as a catalyst for the oxidation of toluene. The amount of iron ...

2005-08-01

69

Proposal of a numerical modeling of reactive flows in combustion chambers of turbojet engines; Proposition d`une modelisation numerique des ecoulements reactifs dans les foyers de turboreacteurs  

Energy Technology Data Exchange (ETDEWEB)

Simplifying hypotheses are required when combustion and aerodynamic phenomena are considered simultaneously. In this paper, a turbulent combustion model is proposed, in which the combustion chemistry is reduced to a single reaction. In this way, only two variables are needed to describe the problem and combustion can be characterized by the consumption of one of the two reactive species. In a first step, the instantaneous consumption rate is obtained using the Lagrangian form of the mass fraction equation of the species under consideration, and by considering the equilibrium state only. This state is determined in order to preserve the consistency with results that should be obtained using a complete kinetics scheme. In a second step, the average rate is determined using the instantaneous consumption term and a probabilistic density function. This model was tested on various configurations and in particular on an experimental main chamber and on a reheating chamber. Results indicate ...

1996-12-31

70

Propagation of an alkaline wave with a short contact time through an argilite sample from the Meuse-Haute Marne underground laboratory; Propagation d'une onde alcaline a temps de contact court a travers un echantillon d'argilite de l'est  

Energy Technology Data Exchange (ETDEWEB)

In the framework of the feasibility study of radioactive waste disposal in deep geologic formations, a clay formation (named 'argilite de l'Est') has been selected in the Meuse-Haute Marne region (France) for the construction of an underground laboratory. The percolation of alkaline solutions through the argilite has been studied using column experiments with short residence times (30 min). These experiments simulate the leaching of a cement which could be used in the building materials of the laboratory. The alkaline solutions used are mono-cationic solutions of calcium, sodium and strontium. The behaviour of calcium is differentiated from the other cations. For all alkaline solutions (NaOH, Ca(OH){sub 2} or Sr(OH){sub 2}) chemical reactions consuming both hydroxide ions and their associated cations have been evidenced. These reactions are heterogenous reactions of surface adsorption by site ionization. The calcium has a different behaviour, more complex, ...

2001-07-01

71

Principe local-global pour les z\\'ero-cycles sur certaines fibrations au-dessus d'une courbe: II  

CERN Document Server

We consider an admissible fibration $\\pi:X\\to\\mathbb{P}^1$ over a curve over a number field, of which the generic fiber $X_\\eta$ is geometrically rationally connected. We suppose that there exists a generalized Hilbertian subset $\\textsf{Hil}$ of $\\mathbb{P}^1$, such that the Brauer-Manin obstruction is the only obstruction to the Hasse principle (resp. to the weak approximation) for $X_\\theta(\\theta\\in \\textsf{Hil}).$ We prove that the Brauer-Manin obstruction is the only obstruction to the Hasse principle (resp. to the strong approximation) for zero-cycles of degree 1 on $X$ in the following cases: $(B_1)$ the index of the generic fibre $X_\\eta$ is equal to 1; $(B_2)$ all fibers are geometrically integral. Then, we obtain some similar results for certain fibrations over $\\mathbb{P}^n$. As a consequence, we obtain the following result: let $X$ be a smooth projective geometrically rationally connected variety over a number field $k$, if the Brauer-Manin obstruction is the ...

2010-01-01

72

Preliminary study of the {sup 129}I distribution in environment of La Hague reprocessing plant with the help of a terrestrial moss: Homalotecium sericeum. Study report; Etude preliminaire de la repartition de {sup 129}I dans l'environnement de l'usine de retraitement de La Hague a l'aide d'une mousse terrestre: Homalotecium sericeum. Rapport d'etude  

Energy Technology Data Exchange (ETDEWEB)

The preliminary study of the {sup 129}I distribution has allowed to underline the limits of use of a Homalotecium sericeum type terrestrial moss as biological indicator. However, this preliminary study allowed all the same to give a spatial distribution of this radioelement around La Hague reprocessing plant (source term) that underlines the existence of four geographic areas in function of collected activities. The levels are generally under 99 Bq/kg dry. It is recommended to improve the knowledge that we can have of transfers and quantity of iodine 129 from the marine environment to the terrestrial environment, but also, the one that we can have of factors able to modify the spatial distribution of this radionuclide. (N.C.)

1999-07-01

73

Physico-chemical behaviour of a barrier composed of cement kiln dust and fly ash; Comportement physico-chimique d'une barriere a base de poussieres de four de cimenterie et de cendres volantes  

Energy Technology Data Exchange (ETDEWEB)

Controlling acid mine drainage is one of the most important challenges facing the mining industry. One of the solutions to this problem is the use of soil covers. In this poster presentation, the author described the development of a soil barrier composed of cement kiln dust and fly ash. In the study, four different cement kiln dust were associated to three different fly ash types, for a total of twelve different mix. The objective was to develop a stable environmental barrier. The origin of the cement kiln dust was described, followed by the characterization and preparation of the different mix, and the monitoring of the hydration process. The results were discussed, and indicated that a barrier composed of cement kiln dust and fly ash seemed to have great potential. The results also indicated that the fly ash improve the properties of the cement kiln dust, but that the improvement was dependent on the nature of the fly ash. 22 figs.

2000-07-01

74

Near-surface velocity modeling at Yucca Mountain using borehole and surface records from underground nuclear explosions  

International Nuclear Information System (INIS)

The Department of Energy is investigating Yucca Mountain, Nevada as a potential site for commercial radioactive waste disposal in a mined geologic repository. One critical aspect of site suitability is the tectonic stability of the repository site. The levels of risk from both actual fault displacements in the repository block and ground shaking from nearby earthquakes are being examined. In particular, it is necessary to determine the expected level of ground shaking at the repository depth for large seismic sources such as nearby large earthquakes or underground nuclear explosions (UNEs). Earthquakes are expected to cause the largest ground motions at the site, however, only underground nuclear explosion data have been obtained at the repository depth level (about 350m below the ground level) to date. In this study we investigate ground motion from Nevada Test Site underground nuclear explosions recorded at Yucca Mountain to establish a compressional velocity ...

2004-02-01

75

Multicentre, randomised, controlled study of the impact of continuous sub-cutaneous glucose monitoring (GlucoDay) on glycaemic control in type 1 and type 2 diabetes patients  

British Library Electronic Table of Contents (United Kingdom)

ResumeObjectif determiner dans une etude randomisee l'impact d'un enregistrement continu du glucose sous-cutane pendant 48 heures sur le controle glycemique trois mois plus tard chez des patients presentant un diabete de type 1 (DT1) ou de type 2 (DT2). Methodes Quarante-huit patients avec un mauvais equilibre glycemique (HbA1c : 8-10,5 %) ont beneficie d'un enregistrement continu du glucose sous-cutane pendant 48 heures avec le systeme GlucoDay (A. Menarini Diagnostics) et ont ete randomises en deux groupes : ajustement de traitement en fonction de l'autosurveillance glycemique capillaire (groupe ASG) ou du profil d'enregistrement continu du glucose sous-cutane (groupe CGM). Le dosage d'HbA1c et le port du GlucoDay ont ete renouveles trois mois plus tard. Resultats Trente-quatre patients ...

2009-01-01

76

In-situ IR reflexion spectroscopy characterization of the passivation layer developed on the surface of lithium electrodes in organic medium; Passivation de surface: une nouvelle voie pour reduire l`autodecharge dans les batteries rechargeables a ions lithium LiMn{sub 2}O{sub 4}/Li  

Energy Technology Data Exchange (ETDEWEB)

the development of lithium metal batteries is hindered by the bad reversibility of the Li{sup +}/Li pair, due to dendrites formation which limits the amount of active matter and can generate short-circuits. The chemical and electrochemical phenomena which take place at the electrode/organic electrolyte interface lead to the formation of a complex passivation film which is of prime importance for the functioning of this type of batteries. The in-situ infrared reflection spectroscopy is well adapted to the chemical study of the passivation layer. Two different techniques were used: the substraction normalized interfacial transform infrared spectroscopy (SNIFTIRS) and the electro-chemically modulated infrared reflectance spectroscopy. These methods have shown that the passivation layer that develops on the surface of the lithium electrode in contact with organic solutions (propylene carbonate, ethylene carbonate and dimethoxyethane) is mainly made of lithium alkyl carbonates (ROCO{sub ...

1996-12-31

77

Dosimetric evaluation and therapeutic response to iodine-131 labelled lipiodol in treatment of hepatocellular carcinomas; Evaluation dosimetrique et reponse therapeutique de la curietherapie metabolique des hepatocarcinomes par le lipiodol marque par l'iode 131  

Energy Technology Data Exchange (ETDEWEB)

Faced with increasing indications for the use of iodine-131 labelled lipiodol in the treatment of hepatocellular carcinoma (HCC), it appears essential to develop an individualized dosimetrY so we can predict the potential effectiveness of this treatment and adjust the activity to be injected. We developed a dosimetric protocol based on imagery and dedicated to calculation of the tumoral dose during the treatment of hepatocellular carcinoma by iodine-131 labelled lipiodol. This concept was developed on a SPECT- CT gantry, and integrates corrections for the phenomena of attenuation, diffusion and dead time. The dose is calculated according to the formalism proposed by the Medical Internal Radiation Dose Committee (MIRD). This protocol was applied to a series of 41 patients in the framework of a retrospective study. The results obtained in terms of biodistribution are compatible with previously published data. The total biological response rate is 42% (n= 41) for the first treatment and ...

2006-12-15

78

Use of neutron activation analysis for the control of air pollution of Algiers; Utilisation de l'analyse par activation neutronique pour le controle de la pollution de l'air d'Alger  

Energy Technology Data Exchange (ETDEWEB)

The urban zone needs clean air to assure public health. To achieve this goal several filter samples were collected in different sites in Algiers city. Toxic elements such as: Na, Mg, Cl, Sc, Cr, Ti, V, Fe, Co, Cu, Zn, Se, Br, Ag, Sb, Ce, La, Hf, Ta and Hg have been measured in the filters using neutron activation analysis technique. Irradiation of filter samples and standards were carried out in Es-Salem reactor. The experimental procedure and the results are discussed. We noted during this work that the upper limit values for suspended dusts and the high concentrations for some toxic elements found are due to the weather conditions and intense road traffic around collecting sites. (authors)

2010-07-15

79

The sanitary consequences of chronicle internal contaminations by radionuclides. Advice on the C.E.R.I. report 'study of sanitary effects of exposure to low doses of ionizing radiation to radiation protection purposes ' and I.R.S.N. recommendations; Les consequences sanitaires des contaminations internes chroniques par des radionucleides. Avis sur le rapport CERI 'Etudes des effets sanitaires de l'exposition aux faibles doses de radiations ionisantes a des fins de radioprotection' et recommandations de l'IRSN  

Energy Technology Data Exchange (ETDEWEB)

The report published in 2003 by the European committee on the risk of irradiation (C.E.R.I.) criticizes a part of the ICRP recommendations relative to the internal contaminations.Consequently, I.R.S.N. wishes to supply its own analysis. The present report points the questions linked to the internal contamination and to the difficulties inherent to the risk incurred after chronic exposure.Consequently it does not treat all the problems of the workers and populations radiation protection. (N.C.)

2005-07-01

80

Production of ultra high strength steels by turbulent water cooling equipment (TWICE); Production d'aciers haute resistance par un dispositif de refroidissement a turbulence controlee  

Energy Technology Data Exchange (ETDEWEB)

A new industrial process allowing to reach very high cooling rates in the cooling section after soaking of a continuous annealing line for steel sheets is presented. This process constitutes the successful conclusion of a long term research programme, jointly carried out at CRM and Arcelor Cockerill-Sambre for three years, including laboratory experiments, pilot scale trials and several industrial campaigns. It is running on from developments performed in the framework of the HOWAQ (Hot Water Quench) process. The process successively combines a moderate cooling step (600 deg C/s for 0.8 mm thick strips), in boiling water, and a faster cooling step (above 700 deg C/s), by impinging turbulent cold water in a box. Its main features are simplicity, resulting from advanced developments, soundness, flexibility and cooling homogeneity. As treated steel products are characterized by improved mechanical properties, outstanding surface quality (corrosion resistance) and exceptional flatness. The ...

2003-08-01

 
 
 
 
81

Nant-De-Chatillon: electric power generation by ORC (organic Rankine cycle) using waste heat from the Chatillon biogas plant; Nant-de-Chatillon: Production d'electricite par ORC a partir des rejets de chaleur du site de methanisation de Chatillon. Resume  

Energy Technology Data Exchange (ETDEWEB)

This report prepared for the Swiss Federal Office of Energy (SFOE) describes the practical realisation and testing of a heat recovery system based on a one-stage organic Rankine cycle with R134a as the working fluid. The waste heat has a temperature of 95 {sup o}C and originates from a gas engine that powers a small co-generation plant fuelled with biogas produced on-site. Two similar cycles have been built, ORC1 with one and ORC2 with two turbines. Only ORC1 has been tested so far. The maximum efficiency measured in these tests was 6.64% (theoretical Carnot-efficiency: 17 %) and the electric power output was 5.0 kW. The problems encountered during commissioning are described and recommendations for further improvements are given.

2005-07-01

82

Magnetic resonance imaging in multiple sclerosis. Imagerie nouvelle par resonance magnetique nucleaire au cours de la sclerose en plaques  

Energy Technology Data Exchange (ETDEWEB)

Magnetic resonance imaging (MRI) has rapidly attained a major position among the examinations used in the diagnostic approach of multiple sclerosis because it is highly sensitive in demonstrating lesions. However, these lesional images may have several meanings, and there is the problem of distinguishing between oedema, which is said to reflect recent lesions, and gliosis which is thought to betray old lesions. The intrinsic MRI parameters studied (i.e. relaxation times) are unable to make this distinction, whereas it is provided by paramagnetic contrast media such as gadolinium. There is no correlation between the changes observed at MRI and the severity of the disease. Another problem is the accuracy of lesion localization, since visualization is predominantly macroscopic. This raises several questions about the demonstration of correlations between clinical signs and site of the lesion(s). At the moment, several teams of neuroradiologists are trying to find the most reliable method ...

1991-09-15

83

Law project adopted by the Senate and authorizing the ratification of the additional protocol to the agreement between France, the European atomic energy community and the international atomic energy agency relative to the application of warranties in France; Projet de loi adopte par le Senat autorisant la ratification du protocole additionnel a l'accord entre la France, la Communaute europeenne de l'energie atomique et l'Agence internationale de l'energie atomique relatif a l'application de garanties en Franc  

Energy Technology Data Exchange (ETDEWEB)

This project of law concerns an additional protocol to the agreement of warranties signed on September 22, 1998 between France, the European atomic energy community and the IAEA. This agreement concerns the declaration of all information relative to the R and D activities linked with the fuel cycle and involving the cooperation with a foreign country non endowed with nuclear weapons. These information include the trade and processing of nuclear and non-nuclear materials and equipments devoted to nuclear reactors (pressure vessels, fuel loading/unloading systems, control rods, force and zirconium tubes, primary coolant pumps, deuterium and heavy water, nuclear-grade graphite), to fuel reprocessing plants, to isotope separation plants (gaseous diffusion, laser enrichment, plasma separation, electromagnetic enrichment), to heavy water and deuterium production plants, and to uranium conversion plants. (J.S.)

2002-10-01

84

L'exercice physique d'endurance est plus efficace que l'exercice aerobie pour le controle par la pression arterielle sur 24heures chez des diabetiques de type 2  

British Library Electronic Table of Contents (United Kingdom)

Aim: The study aimed to analyze blood pressure (BP) responses in individuals with type 2 diabetes (T2D) over a 24h period following resistance (RES) and aerobic (AER) exercise. Methods: Ten adults with T2D (age: 55.8+/-7.7 years; weight: 79.4+/-14.0kg; fasting glucose: 133.0+/-36.7mg.dL^-^1) underwent: (1) AER: 20min of cycling at 90% lactate threshold (90% LT); (2) RES: three laps of a circuit of six exercises with eight repetitions at 70% 1-RM and 40s of recovery; and (3) a control session of no exercise. Heart rate (HR), and systolic (SBP), diastolic (DBP), mean arterial (MAP) and pulse (PP) BP, as well as lactataemia (Lac), VO2, respiratory exchange ratio (RER) and rate of perceived exertion (RPE) were measured at rest, during exercise and control (CON) periods, and 60min after interve...

2011-01-01

85

Influence of vanadium doping on the electrochemical behaviour of MnO{sub 2} rutile; Influence du dopage par le vanadium sur le comportement electrochimique de MnO{sub 2} rutile  

Energy Technology Data Exchange (ETDEWEB)

Vanadium doped manganese bi-oxide has been obtained from a solution containing both cations. The X-ray diffraction of this material indicates a rutile-type phase but the enlargement of some lines supports the existence of several lattice defects. Also the particle size of the doped material is significantly smaller than the one of the non-doped material obtained in the same conditions. The presence of pentavalent vanadium inside the lattice leads to a small amount of trivalent manganese. Electron microscopy shows the existence of defects which have a tendency of becoming well-ordered and to stabilize a sur-structure. At ambient temperature, the electrochemical behaviour of doped manganese bi-oxide is greatly improved when compared to the non-doped phase. This behaviour is due to the presence of numerous lattice defects and to the smaller size of crystallites. In polymer batteries, the behaviour is similar the one of the non-doped material for which the kinetics performances are ...

1996-12-31

86

Follow up of the functioning of a lithium-polymer battery using confocal Raman micro-spectroscopy; Suivi du fonctionnement d`un accumulateur lithium-polymere par microspectrometrie Raman confocale  

Energy Technology Data Exchange (ETDEWEB)

The confocal Raman micro-spectroscopy has been used for the study of a Lithium/polymer electrolyte-LiTFSI/V{sub 2}O{sub 5} type battery in which the polymer electrolyte thickness is of about 80 {mu}m. The analysis is performed on the side of the battery thanks to a specially designed cell which preserves all the characteristics of the real system. The analysis is performed on 20 points aligned between the anode and the cathode and with a depth of several tenth of {mu}m. The analysis of data obtained during charging/output cycles allows to evaluate the gradients of salt concentration inside the electrolyte, the pollutions of LiOH, Li{sub 2}CO{sub 3}, Li{sub 2}O and Li{sub 3}N -type at the lithium interface, but also the structural modifications of the cathode material. The in-situ study of concentration gradients inside the electrolyte is of prime importance for the understanding of dendrites growth. (J.S.) 11 refs.

1996-12-31

87

Equation of state of laser-shocked compressed iron; Equation d'etat du fer comprime par choc laser  

Energy Technology Data Exchange (ETDEWEB)

This thesis enters the field of highly compressed materials equation of state studies. In particular, it focuses on the case of laser shock compressed iron. This work indeed aims at getting to the conditions of the earth's core, comprising a solid inner core and a liquid outer core. The understanding of phenomena governing the core's thermodynamics and the geodynamic process requires the knowledge of iron melting line locus around the solid-liquid interface at 3.3 Mbar. Several experiments were performed to that extent. First, an absolute measurement of iron Hugoniot was obtained. Following is a study of partially released states of iron into a window material: lithium fluoride (LiF). This configuration enables direct access to compressed iron optical properties such as reflectivity and self-emission. Interface velocity measurement is dominated by compressed LiF optical properties and is used as a pressure gauge. Using a dual wavelength reflectivity diagnostic, ...

2004-01-01

88

Development of pyrometallurgical partitioning of transuranium elements from high-level liquid waste. Improvement to pyrometallurgical partitioning process and process demonstration  

Energy Technology Data Exchange (ETDEWEB)

The partitioning of transuranium elements (TRUs) from high-level liquid waste (HLLW) through the use of pyrometallurgical technology has been underway since 1986, for the purpose of the improving the safety and public acceptance of the disposal of high-level vitrified waste. Prior to the pyrometallurgical partitioning process, the alkali metals can be separated at the denitration process for oxide conversion of HLLW, chlorination in a chloride salt bath can be used to effectively convert oxides to chlorides, and evaporated chlorides can be captured with high efficiency in another adopted chloride salt bath. The higher separation factors between actinides and rare earths are obtained in a LiCl-KCl/Bi system than in a LiCl-KCl/Cd system. Based on the results, we propose a practical process flow for partitioning TRUs from HLLW by pyrometallurgical technology. This process was demonstrated successfully using simulated purex waste. Each element of the TRUs was separated with an efficiency ...

1998-10-01

89

Contribution to the study of sputtering and damage of uranium dioxide by fast heavy ions; Contribution a l'etude de la pulverisation et de l'endommagement du dioxyde d'uranium par les ions lourds rapides  

Energy Technology Data Exchange (ETDEWEB)

Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited to describe our ...

2001-03-01

90

Challenges in fabrication of 180deg magnet chamber  

International Nuclear Information System (INIS)

180 deg magnet chamber is used in Folded Tandem Ion Accelerator for passage and 180 deg bending of ion beam. The chamber is placed between 180 deg terminal magnet (Electro-magnet), which is used for bending, and analysing the beams. Magnet with a particular magnetic field strength bends ions of only specified mass energy product through a precise path. There is also a space limitation in the direction of magnetic field. Both of them require the magnet chamber to be of a close tolerance. Accuracy of center distance between inlet and outlet port of the magnet chamber has to be at par with the concentricity of high energy and low energy beam line. To achieve this we started the fabrication of magnet chamber by following two methods: a) Circular rolling and bending of rectangular tube for 180 deg sector of magnet chamber b) Machining 180 deg sector in two half and welding. By first method we could not achieve the desired result although the method is very promising. ...

2006-11-01

91

Atomic spectroscopy study of nuclear properties of francium and cesium isotopes; Etude par spectroscopie atomique de proprietes nucleaires d'isotopes de francium et de cesium  

Energy Technology Data Exchange (ETDEWEB)

This work is based on the study of cesium ({sup 118,146}Cs) and francium ({sup 207-213}Fr,{sup 220-228}Fr) isotopes by hyperfine atomic spectroscopy and on the interpretation of these results from the nuclear physics point of view. The measured nuclear quantities are: the spin, the magnetic moment, the electric quadrupole moment and the mean square charge radius. The experimental method which is based on hyperfine optical pumping with a tunable laser, followed by magnetic analysis of the atoms is described in the first part. Results related to atomic physics are also presented. In the second part, these data are interpreted in the framework of nuclear models. The deformation of light cesium isomers are compared to values obtained from a theoretical self-consistent calculation. Heavy francium isotopes are situated in an area where the existence of static octupole deformations have been predicted. The odd-even staggering measured on the mean square radius is abnormal in this region. ...

1986-04-15

92

Are the French authorities beginning to prepare for nuclear accident?; Introduction a la prise en compte de l'accident nucleaire par les autorites francaises?  

Energy Technology Data Exchange (ETDEWEB)

This article, published in issue 80 of 'l'ACROnique du nucleaire', aims to retrace the early steps in the consideration of the possibility of a nuclear accident in France, with the inclusion of 'non-institutional' participants and applying the lessons learned in Belarus in the contaminated territories around the Chernobyl nuclear power plant. After a review of the origin of the involvement of the Association pour le Controle de la Radioactivite dans l'Ouest (ACRO) in addressing post-accident issues alongside the populations living in an environment polluted by radioactivity, it discusses, from the critical viewpoint of an NGO, the context and the working method adopted for this examination. This is followed by some key elements of the programme and unresolved questions about the available body of knowledge which motivates research and about the method adopted for the work. The conclusion, moderately optimistic, highlights some ...

2008-07-15

93

Angiogenic cytokines and growth factors in systemic sclerosis.  

Science.gov (United States)

Systemic sclerosis is an autoimmune connective tissue disorder characterized by a widespread microangiopathy, autoimmunity and fibrosis of the skin and of various internal organs. Microangiopathy is characterized by a reduced capillary density and an irregular chaotic architecture that lead to chronic tissue hypoxia. Despite the hypoxic conditions, there is no evidence for a sufficient compensative angiogenesis in SSc. Furthermore, vasculogenesis is also impaired. An imbalance between angiogenic and angiostatic factors might explain the pathogenetic mechanisms of SSc vasculopathy. As far as angiogenic factors are concerned, within the most important are vascular endothelial growth factor (VEGF) and its receptors, platelet derived growth factor (PDGF), transforming growth factor beta (TGF-?), fibroblast growth factor -2 (FGF-2), angiopoietin 1 (Ang-1), stromal cell-derived factor 1 (SDF-1/CXCL12), endothelin-1 (ET-1), monocyte chemoattractant protein -1 (MCP-1), urokinase type ...

2011-04-28

94

AFM and STM studies of passive films formed on stainless steels. Applications to stress corrosion cracking; Etudes par microscopie a champ proche des films passifs formes sur les aciers inoxydables. Applications a la corrosion sous contrainte  

Energy Technology Data Exchange (ETDEWEB)

Modelization of crack propagation and theoretical prediction of rupture are the two main objectives of researchers in stress corrosion cracking. Nevertheless, to reach this aim, the behavior of the passive film which appears spontaneously on the substrate in contact with an environment has to be known. This structural and mechanical characterization is all the more difficult because the number of parameters is important: crystallinity rate, defects concentration, thickness (about a few nanometers), electric field, chemical composition (a lot of oxides are present), peeling layers (atomic structure for example) and some hypothesis can be made about their multi-layer structure, their chemical composition or their epitaxial character... Passive films formed on 316L or 304L stainless steels in different aqueous solutions (in ambient air, in MgCl{sub 2} at 117 deg. C...) have been studied and some important remarks about their mechanical properties are made (brittle behavior, strong or weak ...

1995-12-01

95

A fixed cations and low Tg polymer: the poly(4-vinyl-pyridine) quaternized by poly(ethylene oxide) links. Conductivity study; Un electrolyte polymere a cations fixes et bas Tg: les poly(4-vinylpyridine) quaternisees par des chainons de poly(oxyde d`ethylene). Etude de la conductivite  

Energy Technology Data Exchange (ETDEWEB)

The spontaneous ionic polymerization of 4-vinyl-pyridine in presence of mono-tosylated or bromated short chains of poly(ethylene oxide)-(PEO) is used to prepare amorphous comb-like poly-cations with low Tg. The polymer electrolyte properties of these new structures have been studied without any addition of salts. The ionic conductivity of these fixed cation poly-electrolytes depends on the length of the grafted PEO and varies from 10{sup -7} to 10{sup -4} S/cm between 25 and 80 deg. C. It is only weakly dependent on the nature of the cation but it is controlled by the movements of the pyridinium cation which are facilitated by the plastifying effect of the POE chains which do not directly participate to the ionic transport. (J.S.) 17 refs.

1996-12-31

96

The carbonate feedback system: interaction between stratigraphic accommodation, ecological succession and the carbonate factory; Le systeme de feed-back des carbonates: une interaction entre accomodation stratigraphique, succession ecologique et l`usine des carbonates  

Energy Technology Data Exchange (ETDEWEB)

In this paper, the analysis of carbonate depositional systems, using high resolution sequence stratigraphy, studies the ratio between change in accommodation space and skeletal carbonate production. This approach establishes the concurrent change in nature of facies belts (expansion, retraction and type) and fossil communities, within the detailed time frame in accommodation. Carbonate production is generally considered to be a fairly simple function of environmental conditions such as climate and water depth. However, data from several case studies also show a covariance between change in stratigraphic architecture of carbonate systems (the seaward or landward stepping stacking patterns of stratigraphic units) and charge in facies. Case studies include Carboniferous algal mound development in the Paradox Basin (USA), Devonian stromatoporoid reef development in Alberta (Canada), and Cenomanian rudistid shoal development in Oman. The hypotheses are tested on cases taken from the ...

1996-12-31

97

Study of the distribution of gamma emitters radionuclides between a pollution abatement factory and its surrounding environment; Case of the water treatment plant of the Grand Caen district. Study report; Etude de la repartition de radionucleides artificiels emetteurs gamma entre une usine de depollution et son milieu environnant; Cas de la station d'epuration du District du Grand Caen. Rapport d'etude  

Energy Technology Data Exchange (ETDEWEB)

Except nuclear industry, diverse structures (hospitals, of research or manufacturers) can have appeal to the use of radioisotopes conditioned under unsealed shape. Such practices lead to tolerate releases in environment in the respect of a statutory device. So the collective network can contain radioisotopes the future of which is going to depend partially on the cleaning applied to waste water. This study through the analysis of a concrete case, has for objective to inform about the future of gamma radioelements present in waste water treated by a wastewater treatment plant. The contamination of the network is essentially due to Tc{sup 99} and I{sup 131}, radioelements present whatever the working day and the hour considered. The total estimated in-load for a day is important, of the order of 4000 MBq for Tc{sup 99} and 15 to 300 MBq for I{sup 131}. The assessment of cleaning of the station shows that this one plays a role towards this pollution through these stages of treatment. ...

2007-07-01

98

Study of the action of a phosphonate additive on steel scale deposit and corrosion in the hydrodynamic conditions of a channel flow cell; Etude de l'action d'un additif phosphone sur l'entartrage et sur la corrosion de l'acier dans les conditions hydrodynamiques d'une cellule a canal  

Energy Technology Data Exchange (ETDEWEB)

In cooling systems, an improved control of scale deposit and corrosion processes is a major challenge and an realistic evaluation tool for water treatments is of the utmost economic importance. In this study, a channel flow cell was used to allow in-situ electrochemical measurements in well defined electrolyte tube flowing conditions. An expression of the mass transfer towards the electrode was established where the diffusion-limited current is a function of Re{sup 1/3} in the laminar regime and was verified experimentally using the redox couples Fe[CN]{sub 6}{sup 4-}/ Fe[CN]{sub 6}{sup 3-} and O{sub 2}/OH{sup -}. This hydrodynamically controlled experimental device was developed to investigate scale deposit processes and to evaluate scale inhibitor efficiency using a electrochemical quartz crystal microbalance. Experiments were performed on three different waters, at various flow rates and temperatures. The efficiency of a well known phosphonate (HEDP) was tested at different ...

2000-10-17

99

States with several particles in e{sup +}e{sup -} and {gamma}{gamma} colliders: technique of calculation and launch of a new physics; Etats a plusieurs particules dans les collisionneurs e{sup +}e{sup -} et {gamma}{gamma}: techniques de calcul et effets d'une nouvelle physique  

Energy Technology Data Exchange (ETDEWEB)

The mass generation in the Standard Model of Particles Physics relies on a spontaneous symmetry breaking mechanism. Its implementation is recalled, along with its constraints, both theoretical (Naturalness, Stability, Triviality, Unitarity) and experimental (limits of direct and indirect searches, prospects). Calculation techniques for observables evaluation in Perturbative Field Theory are described, particularly Helicity Amplitude method, which is given in details: fermions and vector bosons, massless and massive. Monte-Carlo integration, and structure functions approximations (which allows non-perturbative calculations) are also detailed. With these tools, a process giving to Physics beyond the Standard Model is studied: it leads to an experimental prediction for the LEP collision ring, taking the classical background into account. Technical aspects of a future photon linear collider are reviewed. The production of heavy vector bosons, either the classical Z for the hypothetical ...

1996-10-22

100

On the study of petroleum system operation: contribution of a two-dimensional modeling; Contribution a l`etude du fonctionnement des systemes petroliers: apport d`une modelisation bi-dimensionnelle  

Energy Technology Data Exchange (ETDEWEB)

The aim of the thesis is to validate concepts used in hydrocarbon generation and migration models; the model considered is the Temispack model developed by IFP, and the validation is based on the investigation of the thermal and hydraulic evolution in various sedimentary basins. It is shown that, in general, the thermal history of sediments is influenced by external processes (sedimentation rates, lithology, climate changes, regional-scale groundwater circulations) which frequently overprint internal processes (variations of crustal/mantle heat flow). It is found that external processes can frequently explain past thermal events that were erroneously attributed to internal causes (tectonic-thermal events). The origin of over-pressures in young basins with high sedimentation rates is shown to be generally related to compaction disequilibrium. Shale permeability values calibrated against overpressure profiles are consistent with experimental constraints. Compaction models predict ...

1997-07-10

 
 
 
 
101

Improving radiotherapy quality and safety: a common objective of A.S.N. and the Ile de France Regional Hospital Agency. Thoughts on successful cooperation in Ile de France; Ameliorer la qualite et la securite de la radiotherapie: un objectif conjoint de l'A.S.N. et de l'Agence regionale de l'hospitalisation Ile de France. Reflexions sur une cooperation feconde en Ile de France  

Energy Technology Data Exchange (ETDEWEB)

Radiotherapy recent development in cancer treatment needs strong procedures and quality assessment to improve safety both for patients and professionals. In Ile de France territory, a coordinated action between ASN inspectors and medical doctors specialized in public health (MISP), working as civil servants in health administration, was initiated at the end of 2007. An inspection guideline was implemented in a workshop between ASN and Regional Hospital Agency (ARH). The MISP as health administrator has to verify if care organisation responds to treatment cancer regulatory framework: as a doctor he is authorized to access to patient records to know which treatment was chosen. He has to assure if the therapeutic guidelines are respected. His comprehensive approach is essentially patient-oriented. The MISP inspection coordinated with ASN inspectors is a very pertinent pluri-disciplinary approach, undeniably necessary in such a medical technic. The effectiveness of the radiotherapy ...

2009-02-15

102

A fundamental approach to better understand the lithium insertion mechanisms in electrode materials; Une approche fondamentale pour mieux comprendre les mecanismes d`insertion du lithium dans les materiaux d`electrodes  

Energy Technology Data Exchange (ETDEWEB)

The development of rechargeable lithium batteries with a high mass capacity, made with non-toxic and low cost materials is an important industrial challenge. Morphological and structural modifications occurring in the electrode materials during charge-output cycles should not lower the electrochemical characteristics and the cycling properties of the battery. Thus the structure of electrode materials must be sufficiently deformable and stable to support the constraints linked with lithium intercalation and de-intercalation (ions and electrons absorption/extraction). The aim of this work is to explain some characteristics (mass capacity, ions and electrons mobility, cycling) using the relation between some mechanisms of lithium insertion (sites occupation, lattice reduction mods) and the nature of atoms and chemical bonds (covalence, ionicity). This approach is developed on 2-D models of crystallized and vitreous sulfur compounds (CdI{sub 2} type) with a large inter-sheet distance, and ...

1996-12-31

103

Testing and modification of a simple flow turbine; Messtechnische Untersuchung und Modifikation einer einfachen Durchstroemturbine  

Energy Technology Data Exchange (ETDEWEB)

A study conducted at the IHS had the aim to obtain basic information on whether it is possible to build flow turbines following the free jet principle that are on a par with, or superior to, the conventional design, especially in terms of performance and the efficiency curve. Several inflow contours with a ventilated free jet and a conventional flow turbine were studied. The direct comparison of these variants revealed a slightly enhanced peak load efficiency and a very distinct superiority of the free jet contour during partial load. But the efficiency of all variants failed to attain the values claimed by commercial manufacturers. As compared to the initial contour, peak load efficiency was enhanced by 5 per cent. During partial load, the variants studied showed a distinct superiority of the free jet concept over the contour of conventional flow turbines. (orig.) [Deutsch] Am IHS wurde eine Untersuchung mit dem Ziel durchgefuehrt, grundlegende Aussagen zu ...

1997-12-31

104

Study of the lattice parameter evolution of PWR irradiated MOX fuel by X-Ray diffraction; Etude de l'evolution du parametre cristallin des combustibles MOX irradies en rep par la methode de diffraction des rayons X  

Energy Technology Data Exchange (ETDEWEB)

Fuel irradiation leads to a swelling resulting from the formation of gaseous (Kr, Xe) or solid fission products which are found either in solution or as solid inclusions in the matrix. This phenomena has to be evaluated to be taken into account in fuel cladding Interaction. Fuel swelling was studied as a function of burn up by measuring the corresponding cell constant evolution by X-Ray diffraction. This study was realized on Mixed Oxide Fuels (MOX) irradiated in a Pressurized Water Reactor (PWR) at different burn-up for 3 initial Pu contents. Lattice parameter evolutions were followed as a function of burn-up for the irradiated fuel with and without an annealing thermal treatment. These experimental evolutions are compared to the theoretical evolutions calculated from the hard sphere model, using the fission product concentrations determined by the APPOLO computer code. Contribution of varying parameters influencing the unit cell value is discussed. Thermal treatment effects were ...

1995-07-01

105

Study of Pd-Sn/Al{sub 2}O{sub 3} catalysts prepared by an oxide colloidal route; Etude de catalyseurs Pd-Sn/Al{sub 2}O{sub 3} prepares par voie colloidale oxyde  

Energy Technology Data Exchange (ETDEWEB)

The oxide colloidal route, developed in the laboratory for mono-metallic catalysts, consists in preparing a metallic oxide hydro-sol which leads to the supported catalyst after deposition onto a support and an activation stage. In this work, this method has been adapted to the preparation of alumina supported bimetallic Pd-Sn catalysts to determine its interest for the control of the properties of the bimetallic phase (size, composition and structure). In the preliminary study concerning tin oxide sols, SnO{sub 2} (size=2,3 nm) and Sn{sub 6}O{sub 4}(OH){sub 4} (size = 25 nm) nano-particles were synthesized by neutralization respectively for tin(IV) and tin(H). The control through the pH of the aggregation of the PdO and SnO{sub 2} particles revealed that increasing oxide solubility promotes integral re-dispersion of the oxide particles. To synthesize oxide bimetallic sols, three strategies were defined. Copolymerization (formation of a mixed oxide nano-sol by cross condensation of both ...

2001-09-01

106

Simulation of uranium oxides reduction kinetics by hydrogen. Reactivities of germination and growth; Modelisation de la cinetique de reduction d`oxydes d`uranium par l`hydrogene. Reactivites de germination et de croissance  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to simulate the reduction by hydrogen of the tri-uranium octo-oxide U{sub 3}O{sub 8} (obtained by uranium trioxide calcination) into uranium dioxide. The kinetics curves have been obtained by thermal gravimetric analysis, the hydrogen and steam pressures being defined. The geometrical modeling which has allowed to explain the trend of the kinetics curves and of the velocity curves is an anisotropic germination-growth modeling. The powder is supposed to be formed of spherical grains with the same radius. The germs of the new UO{sub 2} phase appear at the surface of the U{sub 3}O{sub 8} grains with a specific germination frequency. The growth reactivity is anisotropic and is very large in the tangential direction to the grains surface. Then, the uranium dioxide growths inside the grain and the limiting step is the grain surface. The variations of the growth reactivity and of the germination specific frequency in terms of the gases partial pressures and of the ...

1997-12-04

107

One-photon two-electron processes in helium close to the double ionization threshold; Diexcitation electronique de l'helium par un photon au voisinage du seuil de double ionisation  

Energy Technology Data Exchange (ETDEWEB)

This work presents a study of the {sup 1}P{sup 0} excited states of He that can be reached by absorption of a single photon carrying an energy close to the double ionization threshold (DIT) (79 eV). Above the DIT, these states are the double continuum states; below, they are the double excited states. These two types of states are tightly coupled to the single continuum states with or without excitation of the residual ion He{sup +}, owing to their degeneracy in energy. In a one-photon process, these states can only be formed owing to the electronic correlations in the system which must be well described to obtain quantitative good results. Our study is a part of the work which aims at a united description of all these doubly excited, ionized-excited, and double continuum states. We use the Hyperspherical R-Matrix with Semiclassical Outgoing Waves (HRM-SOW) method, initially dedicated to double photoionization studies. We extend it to extract information on the single continuum. This ...

2007-04-15

108

On load flow control in electric power systems  

Energy Technology Data Exchange (ETDEWEB)

This dissertation deals with the control of active power flow, or load flow in electric power systems. During the last few years, interest in the possibilities to control the active power flows in transmission systems has increased significantly. There is a number of reasons for this, coming both from the application side - that is, from power system operations - and from the technological side. where advances in power electronics and related technologies have made new system components available. Load flow control is by nature a multi-input multi-output problem, since any change of load flow in one line will be complemented by changes in other lines. Strong cross-coupling between controllable components is to be expected, and the possibility of adverse interactions between these components cannot be rejected straightaway. Interactions with dynamic phenomena in the power system are also a source of concern. Three controllable components are investigated in this thesis, namely the ...

2000-01-01

109

Modeling of the non isothermal and non isobaric transformations kinetics. Application to the kaolinite de-hydroxylation and to the tri-uranium octo-oxide reduction by hydrogen; Modelisation de la cinetique de transformations non isothermes et (ou) non isobares. Application a la deshydroxylation de la kaolinite et a la reduction de l'octooxyde de triuranium par l'hydrogene  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to be able to describe transformations, occurring when solids and gases are in non isothermal and non isobaric conditions, with kinetic models. A methodology has been used. Two essential processes have to be taken into account: the germination and the growth. The germs are supposed to be formed (at constant temperature and pressure) in the grains surface with a constant velocity by surface unit, (gamma), called germination surface frequency (number of germs.m{sup -2}.s{sup -1}. The growth velocity is characterized by a growth surface reactivity, (phi) (in mol.m{sup -2}.s{sup -1}). With an appropriate transformation model, it is possible to obtain the variations of (gamma) and (phi) in terms of the temperature and pressure which are then used in the calculation of the velocity in non isothermal and non isobaric conditions. In order to validate the developed method, two reactions have been studied. For the first one, the kaolinite de-hydroxylation, an anisotropic ...

2002-12-15

110

Hydroelectric power in Switzerland: large growth potential by increasing the installed power; L'hydraulique suisse: un grand potentiel de croissance par l'augmentation de la puissance  

Energy Technology Data Exchange (ETDEWEB)

Due to its important hydroelectric power generation facilities (about 525 plants with a total power of 13,314 MW producing about 35.3 TWh annually) Switzerland plays an important role in the interconnected European power system. Large artificial storage lakes in the Swiss Alps can generate peak power during hours of highest demand: 9700 MW are available from accumulated energy and the total power of pumped-storage facilities amounts to 1700 MW. The latter allow refilling the reservoirs at periods of low power demand and generating power at periods of peak demand. In the case of favorable conditions, the yearly average power production could be increased by 6% and the production during the winter period (October to March) by 20% by the year 2020. However, looking forward to the year 2050, the annual production is expected to decrease by 3% despite a possible extension of hydropower. This decrease is due to the enforcement of the minimum residual water flow rates required by a new ...

2007-07-01

111

Electrochemical reduction of graphited materials in LiClO{sub 4}-EC and LiClO{sub 4}-PC media: characterization of interface products by transmission electron microscopy; Reduction electrochimique de materiaux graphites en milieux LiCIO{sub 4}-EC et LiCIO{sub 4}-PC: caracterisation des produits d`interface par microscopie electronique a transmission  

Energy Technology Data Exchange (ETDEWEB)

The electrochemical intercalation of non-solvated lithium in different graphited materials has been performed in LiClO{sub 4}-ethylene carbonate (EC) medium. The irreversible capacity observed during the first output is mainly due to the formation of a passivation layer made of electrolyte reduction products. These products have been characterized for different electrode reduction potentials using transmission electron microscopy (image, diffraction) and electron energy loss spectroscopy (EELS). EC reduction on the electrode surface in presence of LiClO{sub 4} leads to the formation of Li{sub 2}CO{sub 3} for potentials close to 0.8 V vs Li{sup +}/Li. For lower potentials, the electrolyte reduction reaction goes on with the formation of different lithium alkyl-carbonates. In LiClO{sub 4}-propylene carbonate (PC) medium, the interface phenomena are different. The reduction of a graphite electrode is characterized by the exfoliation phenomenon which hinders lithium intercalation. On the ...

1996-12-31

112

Development of a 3-D model for eddy current testing: application for fastened structures in aeronautics; Developpement d'un modele pour le controle non destructif par courants de Foucault de structures rivetees en aeronautique  

Energy Technology Data Exchange (ETDEWEB)

One of the Eddy Current Testing issues in aeronautics is the inspection of fastened structures to detect flaws nearby rivets which can grow because of mechanical stress. EADS and the CEA LIST have started a collaborative work with the support of the Ile-de-France Region to develop a simulation tool of EC fastened structures testing, integrated to the CIVA platform, aimed at conceiving testing methods, optimizing and qualifying it. The volume integral method using the Green dyadics formalism has been chosen in order to get a fast resolution of Maxwell equations. A first milestone was to build a simulation model of multilayer structures testing, thanks to the use of the multilayer Green dyads. Because of the rivet volume, 60 times bigger than the one of a typical flaw, a large number of discretization cells are needed. Therefore an iterative method has been developed in order to numerically solve large calculation zones. Finally, the flaw response simulation mostly has to cope with a ...

2007-12-15

113

Determination of anisotropic velocity model by reflection tomography of compression and shear modes; Determination de modele de vitesse anisotrope par tomographie de reflexion des modes de compression et de cisaillement  

Energy Technology Data Exchange (ETDEWEB)

As the jump from 2D to 3D, seismic exploration lives a new revolution with the use of converted PS waves. Indeed PS converted waves are proving their potential as a tool for imaging through gas; lithology discrimination; structural confirmation; and more. Nevertheless, processing converted shear data and in particular determining accurate P and S velocity models for depth imaging of these data is still a challenging problem, especially when the subsurface is anisotropic. To solve this velocity model determination problem we propose to use reflection travel time tomography. In a first step, we derive a new approximation of the exact phase velocity equation of the SV wave in anisotropic (TI) media. This new approximation is valid for non-weak anisotropy and is mathematically simpler to handle than the exact equation. Then, starting from an isotropic reflection tomography tool developed at Lt-'P, we extend the isotropic bending ray tracing method to the anisotropic case and we ...

2001-12-01

114

Challenges in environmental radiological surveillance around nuclear facilities  

International Nuclear Information System (INIS)

To accomplish the environmental radiological surveillance need of India's ambitious nuclear power programme, Health Physics Division is infusing new technologies and improved analytical techniques for day to day measurements of various radionuclides in different environmental matrices. It is essential to have techniques for measuring the concentration of radionuclides just above the background level since the discharges from the nuclear facilities are very low i.e. in the range of 5-10% of the prescribed discharge limits by the regulatory bodies. In view of developing ultra-sensitive techniques, the aim of ongoing programmes of the division is to meet the challenges of measuring ultra trace level of radioactivity by adopting state of art new instrumentation and improved sample processing techniques. This will allow us to measure the lowest level of radioactivity (3H, 90Sr, 137Cs, 239+240Pu, etc.) in the environment and thereby estimating the lowest doses to the members of public. ...

2007-06-05

115

Airborne lidar experiments at the Savannah River Plant, June 1985  

Energy Technology Data Exchange (ETDEWEB)

Results are presented from a series of studies conducted at the Department of Energy (DOE) Savannah River Plant (SRP) with the NASA Airborne Oceanographic Lidar (AOL). These studies included a topographic survey of a {approximately}1000 acre lake basin (presently designated L Lake) which had been excavated for use as a cooling pond for L Reactor; a study of the movement of discharged cooling water in Pond C and the warm arm of Par Pond using Rhodamine WT dye as a tag; initial baseline studies of the vegetation cover of the Steel Creek corridor (through which the outflow of L Lake is carried to the Savannah River); and a demonstration of potential forestry applications of the AOL. These investigations were conducted over a 3-day period in June 1985. The AOL is an advanced airborne laser system capable of making temporal or time history measurements of laser backscatter (bathymetry mode) or spectral measurements of laser induced fluorescence from waterborne ...

1987-09-01

116

Responses of hybrid poplar clones and red maple seedlings to ambient O_3 under differing light within a mixed hardwood forest  

International Nuclear Information System (INIS)

The responses of ramets of hybrid poplar (Populus spp.) (HP) clones NE388 and NE359, and seedlings of red maple (Acer rubrum, L.) to ambient ozone (O_3) were studied during May-September of 2000 and 2001 under natural forest conditions and differing natural sunlight exposures (sun, partial shade and full shade). Ambient O_3 concentrations at the study site reached hourly peaks of 109 and 98 ppb in 2000 and 2001, respectively. Monthly 12-h average O_3 concentrations ranged from 32.3 to 52.9 ppb. Weekly 12-h average photosynthetically active radiation (PAR) within the sun, partial shade and full shade plots ranged from 200 to 750, 50 to 180, and 25 to 75 #mu#mol m"-"2 s"-"1, respectively. Ambient O_3 exposure induced visible foliar symptoms on HP NE388 and NE359 in both growing seasons, with more severe injury observed on NE388 than on NE359. Slight foliar symptoms were observed on red maple seedlings during the 2001growing season. Percentage of total leaf area ...

2004-07-01

117

Occupational exposure to natural radionuclides due to mining activities in Ibadan, Southwestern Nigeria; Exposition professionnelle aux radionucleides naturels emis par les activites minieres a Ibadan au sud-ouest du Nigeria  

Energy Technology Data Exchange (ETDEWEB)

The activity concentrations of potassium, uranium and thorium in minerals and soil samples from a mining site in Ibadan, Southwestern Nigeria were measured using gamma ray spectroscopy method. Effective dose per annum has been calculated from the activity concentrations of dominant gamma-emitting natural radionuclides, potassium, uranium and thorium. Samples collected include minerals (beryl, quartz and feldspar), soil samples from the mining pits, heaps and undisturbed land around the mining site. The activity concentrations of {sup 40}K, {sup 238}U and {sup 232}Th, respectively in Bq kg-1 in the mineral samples were as follows: 1985 +- 16, 4.8 +- 0.9 and 11.8 +- 5.8 for beryl sample, 115.1 +- 27.9, 5.0 +- 1.3 and 6.3 +- 5.0 for feldspar samples and 1421 +- 122, <4.8 and 20.1 +- 3.5 for quartz samples. For the soil samples, the mean activity concentrations of {sup 40}K, {sup 238}U and {sup 232}Th, respectively, were 314.2 +- 5.7, 27.7 +- 2.6 and 11.5 +- 5.9 Bq kg-1 for soil ...

2010-01-15

118

Evolution of surfaces properties for 100Cr6 steel by implantation and ionic mixing; Evolution des proprietes de surface de l`acier 100Cr6 par implantation et melange ioniques  

Energy Technology Data Exchange (ETDEWEB)

Physico-chemical characterizations performed on samples of 100Cr6 steel implanted both with boron and nitrogen revealed the formation of boron nitride along with the following new phases: Fe{sub 1-x}(B, N), Fe{sub 2-x}(B, N) and Fe{sub 3-x}(B, N). A thorough analysis of boron NITRIDE (5BN) indicates that a low ion current density (3 {mu}A.cm{sup -2}) in the case of the boron plus nitrogen sequence favours the formation of sp{sup 2} bonds (hexagonal-BN) while a higher ion current density (6{mu}A.cm{sup -2}) promotes sp{sup 3} bonds (cubic-BN) in the opposite sequence. Tribological tests carried out on these samples revealed that nitrogen and boron implantations do not lead to any significant improvement of friction and wear at variance with the results obtained by others authors. However, on a set samples accidentally contaminated with carbon during implantation, we noticed a considerable improvement of these tribological parameters. As this pollution is commonly encountered in surface ...

1996-07-09

119

MRI-based N-staging in esophageal cancer; N-Staging des Oesophaguskarzinoms mittels MRT unter Verwendung von artefaktreduzierenden LOTA-Sequenzen  

Energy Technology Data Exchange (ETDEWEB)

Purpose: For planning the therapeutic strategies and estimating the prognosis in esophageal cancer, N-staging is very important. To date, MRI still is of minor importance as imaging modality of the mediastinum despite promising developments in the past, like ECG-gating or 'averaging' sequences, e.g. LOTA (Long-term averaging), which facilitate mediastinal and thoracic MR-imaging. In a prospective approach, the value of MRI based N-staging was examined with respect to LOTA-sequences. Material and Methods: Within from weeks prior to esophagectomy, standardized MRI of the esophagus was performed in 15 patients (10 squamous-cell-carcinomas and 5 adenocarcinomas) using a 1.5 T whole body scanner. Imaging quality was classified based on depiction of aortic wall or tracheal wall layers. Criteria for malignant infiltration were a diameter of more than 15 mm or a round appearance of a lymph node together with GD-DTPA enhancement. All data were blinded and separately read by ...

2002-10-01