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Sample records for corrosion sous contrainte

  1. Stress corrosion of unalloyed steels in geological storage conditions; Corrosion sous contrainte des aciers non allies dans les conditions du stockage geologique

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    Didot, A.; Herms, E.; Bataillon, C.; Chene, J. [CEA Saclay, Dept. de Physico-Chimie (DEN/DANS/DPC/SCCME/LECA), 91 - Gif sur Yvette (France); Crusset, D. [Agence Nationale pour la Gestion des Dechets Radioactifs (ANDRA), 92 - Chatenay Malabry (France)

    2007-07-01

    The concept retained for high level and years living radioactive waste disposal is the underground storage. It is then necessary to know the behaviour in time (about 10000 years) of the different constituent elements of the containment. The storage site chosen is the Bures' ones, presenting a clay formation at 600 m of depth. Each compartment is separated of a sufficient distance in order to profit of the thermal dispersion effect in the rock for optimizing the cooling of the package. In this work, has been used an unalloyed steel sur-container. The aim is to understand the resistance of the material under corrosion and loading, and particularly the stress corrosion which is a particular case of cracking assisted by environment. The material studied is a weld of two unalloyed steels obtained by electron beam. Slow traction tests have been carried out in an autoclave in the following experimental conditions: interstitial water in equilibrium with a helium-CO{sub 2} mixture 5.4 per thousand under 50 bar and at a temperature of 90 C. The results show an influence of the hydrogen corrosion on the mechanical behaviour of the material and particularly a decrease of the size of the reduction in area, which is practically unexisting in the case of the melted zone. These results are explained into details. (O.M.)

  2. Allowing for surface preparation in stress corrosion cracking modelling; Prise en compte de l`etat de surface dans la modelisation de la fissuration par corrosion sous contrainte

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    Berge, P.; Buisine, D. [Electricite de France (EDF), 92 - Clamart (France); Gelpi, A. [FRAMATOME, 92 - Paris-La-Defence (France)

    1997-12-31

    When a 600 alloy component is significantly deformed during installation, by welding, rolling, bending, its stress corrosion cracking in Pressurized Water Nuclear Reactor`s primary coolant, is significantly changed by the initial surface treatment. Therefore, the crack initiated time may be reduced by several orders of magnitude for certain surfaces preparations. Allowing for cold working of the surface, for which modelling is proposed, depends less on the degree of cold work then on the depths of the hardened layers. Honing hardens the metal over depths of about one micron for vessel head penetrations, for example, and has little influence on subsequent behaviour after the part deforms. On the other hand, coarser turning treatment produces cold worked layers which can reach several tens of microns and can very significantly reduce the initiation time compared to fine honing. So evaluation after depths of hardening is vital on test pieces for interpreting laboratory results as well as on service components for estimating their service life. Suppression by mechanical or chemical treatment of these layers, after deformation, seems to be the most appropriate solution for reducing over-stressing connected with surface treatment carried out before deformation. (author). 14 refs.

  3. Optimisation par algorithme génétique sous contraintes

    OpenAIRE

    Barnier, Nicolas; Brisset, Pascal

    1999-01-01

    Dans le cadre de la programmation logique par contraintes sur les domaines finis CLP(FD), nous proposons une nouvelle méthode d'optimisation reposant sur un algorithme génétique. L'idée de base est de faire manipuler par l'algorithme génétique des sous-domaines des variables du CSP. La population de l'algorithme génétique est ainsi constituée de chaînes de sous-domaines dont l'adaptation est calculée par la résolution des " sous-CSP " corres\\-pondants qui sont plus simples que le problème ori...

  4. Quantitative characterization of initiation and propagation in stress corrosion cracking. An approach of a phenomenological model; Caracterisation quantitative de l`amorcage et de la propagation en corrosion sous contrainte. Approche d`une modelisation phenomenologique

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    Raquet, O.

    1994-11-25

    A purely phenomenological study of stress corrosion cracking was performed using the couple Z2CN 18.10 (304L) austenitic stainless steel/boiling MgCl{sub 2} aqueous solution. The exploitation of the morphological information (shape of the cracks and size distribution) available after constant elongation rate tests led to the proposal of an analytical expression of the crack initiation and growth rates. This representation allowed to quantitatively characterize the influence of the applied strain rate as well as the effect of corrosion inhibitors on the crack initiation and propagation phases. It can be used in the search for the stress corrosion cracking mechanisms as a `riddle` for the determination of the rate controlling steps. As a matter of fact, no mechanistic hypothesis has been used for its development. (author).

  5. Study of alloy 600`S stress corrosion cracking mechanisms in high temperature water; Etude des mecanismes de corrosion sous contrainte de l`alliage 600 dans l`eau a haute temperature

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    Rios, R.

    1994-06-01

    In order to better understand the mechanisms involved in Alloy 600`s stress corrosion cracking in PWR environment, laboratory tests were performed. The influence of parameters pertinent to the mechanisms was studies : hydrogen and oxygen overpressures, local chemical composition, microstructure. The results show that neither hydrogen nor dissolution/oxidation, despite their respective roles in the process, are sufficient to account for experimental facts. SEM observation of micro-cleavage facets on specimens` fracture surfaces leads to pay attention to a new mechanism of corrosion/plasticity interactions. (author). 113 refs., 73 figs., 15 tabs., 4 annexes.

  6. Embrittlement and anodic process in stress corrosion cracking: study of the influent micro-mechanical parameters; Fragilisation et processus anodiques en corrosion sous contrainte: etude des parametres micro-mecaniques influents

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    Tinnes, J.Ph

    2006-11-15

    We study the influence of local mechanical parameters on crack propagation in Stress Corrosion Cracking, at the scale of the microstructure. Two systems are compared: the CuAl{sub 9}Ni{sub 3}Fe{sub 2} copper-aluminium alloy in synthetic sea water under cathodic polarization, where the crack propagation mechanism is related to strain-assisted anodic dissolution, and the 316L austenitic stainless steel in MgCl{sub 2} solution, where embrittlement mechanisms related to hydrogen effects prevail. We use micro-notched tensile specimen that allow to study isolated short cracks. These experiments are modelled by means of finite elements calculations, and further characterized by Electron Back scattered Diffraction (EBSD) in the case of the 316L alloy. In terms of the local mechanical parameters that control propagation, fundamental differences are outlined between the two systems. They are discussed from the viewpoint of the available models of Stress Corrosion Cracking. (author)

  7. Influence of nitrogen on the stress corrosion cracking resistance of austenitic stainless steels in chloride environment; Influence de l'azote sur la resistance a la corrosion sous contrainte d'aciers inoxydables austenitiques en milieu chlorure

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    Teysseyre, S

    2001-11-01

    The aim of this study is to investigate the influence of nitrogen additions on the Stress Corrosion Cracking (SSC) resistance of austenitic stainless steel in chloride environment. The investigation was carried out in two part: first, an experimental investigation with model industrial steels was carried out and secondly, numerical simulations based on the Corrosion Enhanced Plasticity Model were developed. Both slow strain rate tensile tests and constant load test of the different steels in boiling MgCl{sub 2} (153 deg C) at free potential show that, for a given plastic strain rate, nitrogen addition increases the critical stress for crack initiation without influencing the crack propagation rate. We observed that the creep rate under constant load was affected by the nitrogen content. As a consequence, the SCC behaviour (cracks density and propagation rate) depends on the nitrogen content. We thus confirm that the nitrogen content influences the corrosion - deformation interaction mechanisms via its positive contribution to the flow stress. These experimental results are reproduced semi-quantitatively by means of numerical simulations at the scale of crack. - dislocation interactions. The presence of nitrogen is modelled by an increased lattice friction stress, which in turn affects the dynamics of crack tip shielding by dislocation pile-ups. We conclude that nitrogen addition in austenitic stainless steels increases the SC crack initiation stress in proportion of the increased flow stress, without penalty in terms of SC crack propagation rate. (author)

  8. Stress corrosion mechanisms of alloy-600 polycrystals and monocrystals in primary water: effect of hydrogen; Mecanismes de corrosion sous contrainte de l'alliage 600 polycristallin et monocristallin en milieu primaire: role de l'hydrogene

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    Foct, F

    1999-01-08

    The aim of this study is to identify the mechanisms involved in Alloy 600 primary water stress corrosion cracking. Therefore, this work is mainly focussed on the two following points. The first one is to understand the influence of hydrogen on SCC of industrial Alloy 600 and the second one is to study the crack initiation and propagation on polycrystals and single crystals. A cathodic potential applied during slow strain rate tests does not affect crack initiation but increases the slow crack growth rate by a factor 2 to 5. Cathodic polarisation, cold work and 25 cm{sup 3} STP/kg hydrogen content increase the slow CGR so that the K{sub ISCC} (and therefore fast CGR) is reached. The influence of hydrogenated primary water has been studied for the first time on Alloy 600 single crystals. Cracks cannot initiate on tensile specimens but they can propagate on pre-cracked specimens. Transgranular cracks present a precise crystallographic aspect which is similar to that of 316 alloy in MgCl{sub 2} solutions. Moreover, the following results improve the description of the cracking conditions. Firstly, the higher the hydrogen partial pressure, the lower the Alloy 600 passivation current transients. Since this result is not correlated with the effect of hydrogen on SCC, cracking is not caused by a direct effect of dissolved hydrogen on dissolution. Secondly, hydrogen embrittlement of Alloy 600 disappears at temperatures above 200 deg.C. Thirdly, grain boundary sliding (GBS) does not directly act on SCC but shows the mechanical weakness of grain boundaries. Regarding the proposed models for Alloy 600 SCC, it is possible to draw the following conclusions. Internal oxidation or absorbed hydrogen effects are the most probable mechanisms for initiation. Dissolution, internal oxidation and global hydrogen embrittlement models cannot explain crack propagation. On the other hand, the Corrosion Enhanced Plasticity Model gives a good description of the SCC propagation. (author)

  9. Stress corrosion cracking in the vessel closure head penetrations of French PWR`s; Fissuration par corrosion sous contrainte de penetrations de couvercle de cuve de reacteur nucleaire francais a eau pressurisee

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    Buisine, D.; Cattant, F.; Champredonde, J.; Pichon, C.; Benhamou, C.; Gelpi, A.; Vaindirlis, M.

    1994-01-01

    During a hydrotest in September 1991, part of the statutory decennial in-service inspection, a leak was detected on the vessel head of Bugey 3, which is one of the first 900 MW 3-loop PWR`s in France. This leak was due to a cracked penetration used for a control rod drive mechanism. The investigations performed identified Primary Stress Corrosion Cracking of Alloy 600 as being the origin of this degradation. So a lot of the same design PWR`s are a concern due to this generic problem. In this case, PWSCC was linked to: - hot temperature of the vessel head; - high residual stresses due to the welding process between peripherical penetrations and the vessel head; - sensitivity of forged Alloy 600 used for penetration manufacturing. This following paper will present the cracked analysis based, in particular, on the main results obtained in France on each of these items. These results come from the operating experience, the destructive examinations and the programs which are running on stress analysis and metallurgical characterizations. (authors). 9 figs., 2 tabs.

  10. Les objets sous contrainte. Gages, saisies, confiscations, vols,pillages, recel au Moyen Âge

    Directory of Open Access Journals (Sweden)

    Laurent Feller

    2010-10-01

    Full Text Available Du jeudi 20 au samedi 21 novembre 2009, à l’initiative d’Ana Rodriguez et de Laurent Feller, s’est tenu à Auxerre, dans la maison du Coche d’Eau, un séminaire d’études international portant sur Les objets sous contrainte. Gages, saisies, confiscation, vol, pillage, recel au Moyen Âge. Organisée conjointement par le Lamop, l’université de Paris 1 et le CCHS (CSIC de Madrid, partiellement financée par un projet Picasso de l’association Égide, l’opération a bénéficié du soutien de l’université ...

  11. Metallurgical and mechanical parameters controlling alloy 718 stress corrosion cracking resistance in PWR primary water; Facteurs metallurgiques et mecaniques controlant l'amorcage de defauts de corrosion sous contrainte dans l'alliage 718 en milieu primaire des reacteurs a eau sous pression

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    Deleume, J

    2007-11-15

    Improving the performance and reliability of the fuel assemblies of the pressurized water reactors requires having a perfect knowledge of the operating margins of both the components and the materials. The choice of alloy 718 as reference material for this study is justified by the industrial will to identify the first order parameters controlling the excellent resistance of this alloy to Stress Corrosion Cracking (SCC). For this purpose, a specific slow strain rate (SSR) crack initiation test using tensile specimen with a V-shaped hump in the middle of the gauge length was developed and modeled. The selectivity of such SSR tests in simulated PWR primary water at 350 C was clearly established by characterizing the SCC resistance of nine alloy 718 thin strip heats. Regardless of their origin and in spite of a similar thermo-mechanical history, they did not exhibit the same susceptibility to SCC crack initiation. All the characterized alloy 718 heats develop oxide scale of similar nature for various exposure times to PWR primary medium in the temperature range [320 C - 360 C]. {delta} phase precipitation has no impact on alloy 718 SCC initiation behavior when exposed to PWR primary water, contrary to interstitial contents and the triggering of plastic instabilities (PLC phenomenon). (author)

  12. Les oasis sahariennes à foggara: mutations sociales sous fortes contraintes écologiques

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    J.P. Cheylan

    1990-12-01

    Full Text Available Dynamiques sociales et spatiales semblent se correspondre, pour peu que l’on soit parvenu à mettre en évidence leurs articulations. Certaines mettent en jeu des contraintes complexes liant société et espace, leur lecture demande un décryptage. Lire l’espace oasien semble conduire à une lecture des implications des mutations sociales dans l’autre espace, celui de la ville.

  13. Sous-espaces de Mouvements Articulés ou Contraints et leurs Signatures

    OpenAIRE

    2014-01-01

    National audience; Les objets articulés ou à trajectoires contraintes représentent une grande part des objets de notre quotidien. La détection automatique de ces restrictions de mouvement entre objets et l'extraction des paramètres correspondant est donc importante, p. ex. pour augmenter une reconstruction 3D statique avec des paramètres dynamiques tels qu'axes de rotation, ou directions possibles de translation de certains objets. C'est pourquoi nous présentons ici une nouvelle théorie pour ...

  14. Thérèse et Louise, ou le plaisir sous la contrainte

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    Jean-Pierre Cavaillé

    2009-01-01

    Full Text Available Nous nous proposons de confronter ici Thérèse philosophe, dont l’attribution à Boyer d’Argens semble désormais à peu près certaine, à quelques unes de ses sources du siècle précédent, et en particulier, aux Dialogues de Louisa Sigea, sous leurs deux formes majeures, l’original latin attribué à Nicolas Chorier ou à son patron Salvaing de Boissieu, publié d’abord en 1659, et sa très belle transposition, plutôt que traduction au sens strict, de 1680, l’Académie des Dames, qui contient à la fois ...

  15. Stress corrosion of austenitic steels mono and polycrystals in Mg Cl{sub 2} medium: micro fractography and study of behaviour improvements; Corrosion sous contrainte de mono et polycristaux d`aciers inoxydables austenitiques en milieu MgCI{sub 2}: analyse microfractographique et recherche d`ameliorations du comportement

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    Chambreuil-Paret, A

    1997-09-19

    The austenitic steels in a hot chlorinated medium present a rupture which is macroscopically fragile, discontinuous and formed with crystallographic facets. The interpretation of these facies crystallographic character is a key for the understanding of the stress corrosion damages. The first aim of this work is then to study into details the micro fractography of 316 L steels mono and polycrystals. Two types of rupture are observed: a very fragile rupture which stresses on the possibility of the interatomic bonds weakening by the corrosive medium Mg Cl{sub 2} and a discontinuous rupture (at the micron scale) on the sliding planes which is in good agreement with the corrosion enhanced plasticity model. The second aim of this work is to search for controlling the stress corrosion by the mean of a pre-strain hardening. Two types of pre-strain hardening have been tested. A pre-strain hardening with a monotonic strain is negative. Indeed, the first cracks starts very early and the cracks propagation velocity is increased. This is explained by the corrosion enhanced plasticity model through the intensifying of the local corrosion-deformation interactions. On the other hand, a cyclic pre-strain hardening is particularly favourable. The first micro strains starts later and the strain on breaking point levels are increased. The delay of the starting of the first strains is explained by a surface distortion structure which is very homogeneous. At last, the dislocations structure created in fatigue at saturation is a planar structure of low energy which reduces the corrosion-deformation interactions, source of micro strains. (O.M.) 139 refs.

  16. Role of hydrogen in the intergranular cracking mechanism by stress corrosion in primary medium of nickel based alloys 600 and 690; Role de l'hydrogene dans le mecanisme de fissuration intergranulaire par corrosion sous contrainte en milieu primaire des alliages base nickel 600, 690

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    Odemer, G.; Coudurier, A.; Jambon, F.; Chene, J. [CEA Saclay, Dept. de Physico-Chimie (DEN/DANS/DPC/SCCME/LECA), 91 - Gif sur Yvette (France); Odemer, G.; Coudurier, A.; Chene, J. [Evry Univ., UMR 8587 CNRS / CEA, LAMBE, 91 (France)

    2007-07-01

    The aim of this work is to characterize the sensitivity to hydrogen embrittlement of alloys 600 and 690 in order to better understand the eventual role of hydrogen in the stress corrosion mechanism which affects these alloys when they are exposed in PWR primary medium. (O.M.)

  17. TEM characterisation of stress corrosion cracks in nickel based alloys: effect of chromium content and chemistry of environment; Caracterisation par MET de fissures de corrosion sous contrainte d'alliages a base de nickel: influence de la teneur en chrome et de la chimie du milieu

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    Delabrouille, F

    2004-11-15

    Stress corrosion cracking (SCC) is a damaging mode of alloys used in pressurized water reactors, particularly of nickel based alloys constituting the vapour generator tubes. Cracks appear on both primary and secondary sides of the tubes, and more frequently in locations where the environment is not well defined. SCC sensitivity of nickel based alloys depends of their chromium content, which lead to the replacement of alloy 600 (15 % Cr) by alloy 690 (30 % Cr) but this phenomenon is not yet very well understood. The goal of this thesis is two fold: i) observe the effect of chromium content on corrosion and ii) characterize the effect of environment on the damaging process of GV tubes. For this purpose, one industrial tube and several synthetic alloys - with controlled chromium content - have been studied. Various characterisation techniques were used to study the corrosion products on the surface and within the SCC cracks: SIMS; TEM - FEG: thin foil preparation, HAADF, EELS, EDX. The effect of chromium content and surface preparation on the generalised corrosion was evidenced for synthetic alloys. Moreover, we observed the penetration of oxygen along triple junctions of grain boundaries few micrometers under the free surface. SCC tests show the positive effect of chromium for contents varying from 5 to 30 % wt. Plastic deformation induces a modification of the structure, and thus of the protective character, of the internal chromium rich oxide layer. SCC cracks which developed in different chemical environments were characterised by TEM. The oxides which are formed within the cracks are different from what is observed on the free surface, which reveals a modification of medium and electrochemical conditions in the crack. Finally we were able to evidence some structural characteristics of the corrosion products (in the cracks and on the surface) which turn to be a signature of the chemical environment. (author)

  18. Improvement of stress corrosion cracking (SCC) resistance by cyclic pre-straining of 316L austenitic stainless steel in an aqueous boiling MgCl{sub 2} solution; Amelioration de la tenue a la corrosion sous contrainte (CSC) de l'acier inoxydable austenitique 316L en solution bouillante de MgCl{sub 2} par application d'une predeformation cyclique

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    Curiere, I. de; Bayle, B.; Magnin, Th. [Ecole Nationale Superieure des Mines, URA CNRS 1884, 42 - Saint-Etienne (France)

    2000-07-01

    Improving the materials resistance to stress corrosion cracking (SCC) has become a topic of wide interest for theoretical, engineering and financial reasons. The aim of this paper is to propose a process to delay the SCC damage. Recent studies of 316L austenitic stainless steel in boiling MgCl{sub 2} solutions show an improvement in SCC resistance by cyclic pre-straining in low cycle fatigue. This improvement consists of an increase in both strain to failure and crack initiation strain, during Slow Rate Tensile (SSRT) tests in aqueous solution. This paper analyses the effect of pre-fatigue in 316L on its mechanical and electrochemical responses to better understand the delay of SCC damage in boiling MgCl{sub 2}. The explanation for this beneficial effect is related to a modification of both surface electrochemical reactions kinetics and corrosion/plasticity interactions at the crack tip, due to the particular dislocation structure. (authors)

  19. A phenomenological study of initiation and propagation of stress corrosion cracks. Application to AISI 304L stainless steel in magnesium chloride; Etude phenomenologique de l`amorcage et de la propagation de fissures de corrosion sous contraintes. Application a l`acier inoxydable Z 2CN 18.10 dans le chlorure de magnesium

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    Peyrat, C.; Raquet, O.; Helie, M.; Santarini, G. [CEA Fontenay-aux-Roses, 92 (France). Service de la Corrosion, d`Electrochimie et Chimie des Fluides

    1999-04-01

    A purely phenomenological study of Stress Corrosion Cracking (SCC) was performed using the couple AISI 304L austenitic stainless steel/boiling magnesium chloride aqueous solution. The exploitation of the morphological information (shape of the cracks and size distribution) available after constant elongation rate tests led to the apparent initiation of the cracks and to their growth rate. A law for the real initiation is proposed too and the elongation rate effect in quantitatively characterized. (authors) 8 refs.

  20. Part of the hydrogen in the intergranular crack by stress corrosion in primary circuit for the 600 and 690 nickel base alloys; Role de l'hydrogene dans le mecanisme de fissuration intergranulaire par corrosion sous contrainte en milieu primaire des alliages base nickel 600 et 690

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    Odemer, G.; Coudurier, A.; Jambon, F.; Chene, J. [CEA Saclay, Dept. de Physico-Chimie (DPC/SCCME/LECA), 91 - Gif sur Yvette (France); Odemer, G.; Coudurier, A.; Chene, J. [Evry Univ., UMR 8587 CNRS / CEA, LAMBE, 91 (France)

    2007-07-01

    The aim of this study is, in a first part, to characterize the hydrogen embrittlement sensitivity of the 600 and 690 based alloys in order to better understand the hydrogen role in the stress corrosion mechanism which appears in theses alloys in the primary circuit of the PWR type reactors. The authors studies how the hydrogen embrittlement is resulting from an interaction between the hydrogen and the plastic deformation. (A.L.B.)

  1. Development and validation of an experimental procedure for studying the biaxial stress corrosion. Application to the systems: alloy-600/air and 316L/MgCl{sub 2}; Developpement et validation d'une procedure experimentale pour l'etude de la corrosion sous contrainte biaxiale. Application aux couples alliage 600 / air et 316L / MgCl{sub 2}

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    Farre, M.Th

    1998-07-15

    One of the main preoccupation for maintaining EdF's nuclear pressurised water reactors is intergranular stress corrosion cracking of steam generator tubing (alloy 600: NC 15Fe). The most affected areas (first row U-bend and roll transition zone) are in biaxial stress state. The crack propagation is often axial and sometimes circumferential. The actual life prediction criterion for these structures depends on the maximal principal stress. The purpose of this study is to determine whether it is safe to use such a criterion in a case of biaxial stress state. A procedure is proposed and experimentally validated for designing specimen in a controlled biaxial stress state when submitted to traction. Quadrants I an IV of the stress space are the only ones explored. The aim is to use these specimens in order to realize stress corrosion tests in primary water with alloy 600. The procedure involves studying the biaxial behavior of the material. This shows the effect of hardening on the shape of the yield stress surface. The hardening of alloy 600 is mainly kinematic. The yield stress surface becomes concave in the hardening stress direction and flat in the opposite direction. The geometry of the specimen stems from parameterized shape optimisation. An elasto-viscoplastic behavior law is identified for alloy 600. Use of the law for calculating the strain state of one specimen is experimentally validated. This entire procedure has been successfully validated with biaxial stress corrosion cracking tests, using 316L and MgCl{sub 2} boiling at 154 deg C. In this case it is difficult to determine a life time criterion. It is shown that the criterion of the maximal principal stress is invalid in case of a biaxial stress state. (author)

  2. Iodine induced stress corrosion of zirconium and zircaloy-4 mechanisms. Translation to pellet cladding interaction conditions in PWR type reactors; Mecanismes de corrosion sous contrainte par l`iode dans le zirconium et le zircaloy-4. Transposition aux conditions d`interaction pastille-gaine dans les reacteurs a eau pressurisee

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    Fregonese, M

    1997-10-08

    This thesis is linked to the study of the Pellet-Cladding Interaction (PCI) phenomenon in Pressurized Water Reactors, which can lead to cladding rupture by iodine Stress Corrosion Cracking (SCC) of Zircaloy-4. Results are obtained through slow tensile tests performed in iodine methanol and in iodine vapour, on reference material, neutron irradiated material, and iodine zirconium implanted material. They allow to propose an explanation of the rapidity of the ruptures observed during PCI loadings, and to make the link between laboratory SCC tests and power ramp tests. Indeed, neutron irradiation facilitates the initiation and the transgranular propagation steps of the SCC cracks, due to strain localization and hardening associated to the presence of irradiation defects. On the other hand, recoiled iodine does not seem to affect SCC susceptibility of the material. On a chemical point of view, thermally released iodine is then responsible for PCI/SCC ruptures. A detailed calculation of iodine amount created by fission and released in the gap during irradiation makes it possible to show that local iodine concentration facing the pellet-to-pellet and the radial pellet cracks regions is sufficient for SCC cracks to develop in the metal. Finally, a competition between re-passivation and cracking is underscored. This results are in good agreement with the occurrence of an iodine adsorption mechanism. Adsorption could be assisted by a corrosion-deformation interaction phenomenon, and/or by the formation of solid and gaseous zirconium iodides. (author) 132 refs.

  3. Influence of localized deformation on A-286 austenitic stainless steel stress corrosion cracking in PWR primary water; Influence de la localisation de la deformation sur la corrosion sous contrainte de l'acier inoxydable austenitique A-286 en milieu primaire des REP

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    Savoie, M

    2007-01-15

    Irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steels is known to be a critical issue for structural components of nuclear reactor cores. The deformation of irradiated austenitic stainless steels is extremely heterogeneous and localized in deformation bands that may play a significant role in IASCC. In this study, an original approach is proposed to determine the influence of localized deformation on austenitic stainless steels SCC in simulated PWR primary water. The approach consists in (i) performing low cycle fatigue tests on austenitic stainless steel A-286 strengthened by {gamma}' precipitates Ni{sub 3}(Ti,Al) in order to shear and dissolve the precipitates in intense slip bands, leading to a localization of the deformation within and in (ii) assessing the influence of these {gamma}'-free localized deformation bands on A-286 SCC by means of comparative CERT tests performed on specimens with similar yield strength, containing or not {gamma}'-free localized deformation bands. Results show that strain localization significantly promotes A-286 SCC in simulated PWR primary water at 320 and 360 C. Moreover, A-286 is a precipitation-hardening austenitic stainless steel used for applications in light water reactors. The second objective of this work is to gain insights into the influence of heat treatment and metallurgical structure on A-286 SCC susceptibility in PWR primary water. The results obtained demonstrate a strong correlation between yield strength and SCC susceptibility of A-286 in PWR primary water at 320 and 360 C. (author)

  4. Contribution of the low cycle fatigue on ultra high purity Ni-Cr-Fe alloys and on Ni monocrystals to the understanding of the hydrogen role in stress corrosion cracking for the alloys 600 and 690; Apport de la fatigue oligocyclique sur alliages Ni-Cr-Fe d'ultra haute purete et sur monocristaux de Ni a la comprehension sous contrainte des alliages 600 et 69O

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    Renaudot, N

    1999-06-01

    We discuss the role of hydrogen in cracking of Ni base alloys used for pressurised water reactor (PWR) primary tubes (alloy 600 and 690). Cracking can be explained by a Stress Corrosion Cracking (SCC) phenomenon. For this purpose, Low cycle fatigue (R = - 1) under cathodic charging at room temperature is conducted to study hydrogen effects on propagation of cracks mechanically initiated by the formation of Persistent Slip Bands (PSB). Low cycle fatigue on Ultra High Purity specimens (Ni, alloy 600 and 690) reveals the very important hydrogen effect on crack propagation rate, whatever the Cr content in the Ni base alloy. If Cr seems to have an effect over-hydrogen penetration in specimens (by a protective film formation), it have no beneficial effect when hydrogen have diffused ahead of a crack tip. Propagation rates (transgranular or intergranular) are highly increased, no matter of the absence of impurities like sulphur. Then, in PWR, the difference in the behaviour of alloy 600 and 690 could be due to a slower microcrack propagation rate for alloy 690. Protective films could play an important role in this difference, which is to study. Low cycle fatigue on Ni single crystals oriented for single slip shows, for the first time on bulk specimen, a macroscopic softening which can be explained. by hydrogen-dislocation interactions. Moreover, a simple quantitative model based on these interactions results in the same softening as the one observed experimentally. These results allow to validate experimentally one of the most important steps in the 'Corrosion Enhanced Plasticity (CEP) model', i.e. the softening ahead of a stress corrosion crack tip by hydrogen dislocation interactions. This is of importance because this model can explain cracking in numerous FCC materials-environment couple. (author)

  5. La contrainte client

    Directory of Open Access Journals (Sweden)

    Guillaume Tiffon

    2011-04-01

    Full Text Available Cet article montre que le contact client a beau être ambivalent, dans la mesure où il est à la fois source de contrainte et de reconnaissance, dans certains cas, comme celui des caissières, il constitue avant tout une contrainte, en ce que les clients contrôlent le travail qui s’opère « sous leurs yeux », tandis que, dans d’autres cas, comme celui des kinésithérapeutes, il contribue avant tout à donner du sens au travail et, par là, à susciter l’engagement des travailleurs. L’article souligne ainsi combien la contrainte client revêt des modalités différentes selon la configuration, spatiale et temporelle, dans laquelle se déroule la relation de service, et le différentiel de compétences entre les protagonistes engagés dans cette relation.The client constraint. A comparative analysis of cashiers and physiotherapistsThis article shows that despite the ambivalence of client contact, insofar as it is both a source of constraint and recognition, in some cases, as the ones of cashiers, it isprimarily a constraint: clients control the work that takes place “before their eyes”, whereas in other cases – as in the ones of physiotherapists – it contributes to give meaning to work and, thereby, to arouse the commitment of workers. The article highlights how the client constraint takes on different forms depending on thespatial and temporal configuration where the service relation runs, and the skills differential between the protagonists involved in this relation.El apremio de los clientes. Análisis comparativo entre las cajeras de supermercado y los kinesiterapeutasEn este artículo se demuestra que aunque el contacto con los clientes puede ser percibido como agradable, en realidad en la mayoría de los casos el cliente es percibido como un peso puesto que estos « controlan » visualmente el trabajo de las cajeras mientras que en otras profesiones como es el caso de los kinesiterapeutas la presencia del paciente

  6. Prévision de l'injection de cire pétrolière dans des câbles de précontrainte extérieure

    OpenAIRE

    Roussel, N; Farcas, F.; DAUVILLIERS, M; BOUHLASSI, A; PELET, C; Baumgartner, J; BOUST, J

    2007-01-01

    La protection contre la corrosion des câbles de précontrainte peut être réalisée par injection dans les gaines de précontrainte de produits souples comme les graisses, les cires pétrolières ou les résines époxydes. Cependant, avec l'augmentation de la longueur des câbles, des déformations excessives des gaines sous l'effet de pressions d'injection dépassant les pressions admissibles ont été constatées récemment. L'ambiguïté qui existe d'un point de vue réglementaire sur le choix de la géométr...

  7. Alliages magnétiques FePd et FePt en couches minces sous contrainte épitaxiale : mise en ordre en température et propriétés magnétiques

    Science.gov (United States)

    Arenal de La Concha, R.; Schuster, I.; Halley, D.; Marty, A.; Bayle-Guillemaud, P.

    2002-07-01

    In order to increase the storage capacities of the media of magnetic recording one seeks to decrease the size of the magnetic fields which carry information. The growth of thin layers of magnetic alloys in ordered phases makes it possible to plan structures with very strong perpendicular magnetic anisotropy, necessary to obtain stable fields in spite of their reduced size. We studied, thanks to an original device of in temperature X-rays diffraction, the ordering of FePd layers or FePt deposited by MBE in different states of initial order and constraint, then submitted to heat treatment. The ordering occured along the growth axis. The structure of the layers is very inhomogeneous: not ordered and ordered domains coexist, with or without defect in the stacking of the L10 phase, even domains of other phases. The small zones, which have been ordered during the growth, do not seem to take part in the development of the long range order during the treatment. The evolution of the ordered fraction is identical whatever the imposed state of epitaxial stress. Modifications of the experimental conditions make it possible from now to plan more systematic measurements with a temperature history more rigorous in order to confirm these observations. Afin d'augmenter les capacités de stockage des media d'enregistre ment magnétique, on cherche à diminuer la taille des domaines magnétiques qui portent l'information. L'élaboration de couches minces d'alliages magnétiques dans des phases ordonnées permet d'envisager des structures à très forte anisotropie magnétique perpendiculaire, nécessaire pour obtenir des domaines stables malgré leur taille réduite. Nous avons étudié, grâce à un dispositif original de diffraction X en température, la mise en ordre de couches FePd ou FePt déposées par MBE dans des états différents d'ordre initial et de contrainte. La mise en ordre se fait selon l'axe de croissance. La structure des couches est très inhomogène : coexistent

  8. Some problems on the aqueous corrosion of structural materials in nuclear engineering; Problemes de corrosion aqueuse de materiaux de structure dans les constructions nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H.; Grall, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The purpose of this report is to give a comprehensive view of some aqueous corrosion studies which have been carried out with various materials for utilization either in nuclear reactors or in irradiated fuel treatment plants. The various subjects are listed below. Austenitic Fe-Ni-Cr alloys: the behaviour of austenitic Fe-Ni-Cr alloys in nitric medium and in the presence of hexavalent chromium; the stress corrosion of austenitic alloys in alkaline media at high temperatures; the stress corrosion of austenitic Fe-Ni-Cr alloys in 650 C steam. Ferritic steels: corrosion of low alloy steels in water at 25 and 360 C; zirconium alloys; the behaviour of ultrapure zirconium in water and steam at high temperature. (authors) [French] On presente un ensemble d'etudes de corrosion en milieu aqueux effectuees sur des materiaux utilises, soit dans la construction des reacteurs soit pour la realisation des usines de traitement des combustibles irradies. Les differents sujets etudies sont les suivants. Les alliages austenitiques Fer-Nickel-Chrome: comportement d'alliages austenitiques fer-nickel-chrome en milieu nitrique en presence de chrome hexavalent; Corrosion sous contrainte d'alliages austenitiques dans les milieux alcalins a haute temperature; Corrosion sous contrainte dans la vapeur a 650 C d'alliages austenitiques fer-nickel-chrome. Les aciers ferritiques; Corrosion d'aciers faiblement allies dans l'eau a 25 et 360 C; le zirconium et ses alliages; Comportement du zirconium tres pur dans l'eau et la vapeur a haute temperature. (auteurs)

  9. Towards a quantification of stress corrosion mechanisms: numerical simulations of hydrogen-dislocations at the very crack tip; Vers une quantification des mecanismes de corrosion sous contrainte: simulations numeriques des interactions hydrogene-dislocations en pointe de fissure

    Energy Technology Data Exchange (ETDEWEB)

    Chateau, J.P

    1999-01-05

    We discuss the respective roles played by anodic dissolution and hydrogen in SCC mechanisms of f.c.c. materials, by studying the fracture of copper in nitrite for which we compare the results with that previously obtained in 316L steel in hot chloride. It is surprising to note that even the crystallographies at the scale of the micron are different, the macroscopic inclination of the fracture surfaces are the same. In the case of 316L steel, the formation of strong pile-ups in the presence of hydrogen leads to a zigzag fracture along alternated slip planes in the most general case. In the absence of hydrogen, as in copper, this mechanism effectively disappears. Furthermore, numerical simulations of crack shielding by dislocations emitted on one plane predict the macroscopic inclination. It shows that it is due to the mere dissolution which confines slip activity at the very crack tip in f.c.c. materials. In order to quantify the mechanism involved in 316L steel, we developed simulations which numerically solve the coupled diffusion and elasticity equations for hydrogen in the presence of a crack and shielding dislocations. They reproduce the mechanisms of hydrogen segregation on edge dislocations and of a localised softening effect by decreasing pair interactions. These mechanisms lead to i) a localisation of hydrogen embrittlement along the activated slip planes, ii) an increase of the dislocation density in pile-ups, and iii) a decrease of the cross slip probability. These three factors enhance micro-fracture at the head of a pile-up, which is responsible of thezigzag fracture. Introducing the free surface effects for hydrogen, we point out a new mechanism: the inhibition of dislocation sources at the crack tip, which is relevant with the brittle fracture surfaces observed in some cases in 316L steel. The quantification of these different mechanisms allows to give a relation between the local fracture possibility and the macroscopic parameters. A general law for softening is proposed, and we show that micro-fracture occurs for realistic values of three key parameters: hydrogen concentration, decrease of k{sub lc} and obstacle resistance. (author)

  10. Stress corrosion cracking of Ni-based alloys in PWR primary water. Component surface control; Corrosion sous contrainte des alliages a base nickel en milieu primaire des reacteurs a eaux pressurisee. Maitrise de la surface des composants

    Energy Technology Data Exchange (ETDEWEB)

    Foucault, M. [AREVA, Centre Technique Framatome ANP, Dept. Corrosion Chimie, 71 - Le Creusot (France)

    2004-06-01

    In the PWR plant primary circuit, FRAMATOME-ANP uses several nickel-base alloys or austenitic stainless steels for the manufacture of safety components. The experience feedback of the last twenty years allows us to point out the major role played by the surface state of the components in their life duration. In this paper, we present two examples of problems encountered and solved by a surface study and the definition and implementation of a process for the surface control of the repair components. Then, we propose some ideas about the present needs in terms of analysis methods to improve the surface knowledge and the control of the manufactured components. (author)

  11. Contraintes syntaxiques et modales des noms recteurs dans la complétive finie en français*

    Directory of Open Access Journals (Sweden)

    Kanté Issa

    2016-01-01

    Full Text Available Cette étude propose, d’une part, une analyse typologique des complétives du nom en français, et d’autre part, elle manifeste une série de mécanismes qui sous-tendent les contraintes syntaxiques et sémantiques en jeu dans cette construction. Outre l’analyse typologique, deux contraintes sémantico-syntaxiques retiennent particulièrement notre attention : les contraintes de sélection du nom recteur (la contrainte de rection et, dans une moindre mesure, celles portant sur la modification du nom recteur par un adjectif. Nous défendons l’hypothèse qu’outre la structure de l’énoncé et la position syntaxique du nom recteur, la contrainte de rection relève en grande partie des propriétés modales inhérentes au nom recteur. Quant à la contrainte de modification par un adjectif, nous montrons qu’elle dépend en particulier de la structure lexico-syntaxique de la complétive. Autrement dit, la fonction syntaxique qu’occupe le nom recteur dans la phrase et la relation syntagmatique dans laquelle il apparaît jouent un rôle crucial dans l’acceptabilité ou non d’un adjectif au sein du syntagme nominal recteur.

  12. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  13. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  14. Fault Permeability and Strength Evolution Related to Fracturing and Healing Episodic Processes (Years to Millennia: the Role of Pressure Solution Évolution de la perméabilité et de la résistance des failles associée à des processus épisodiques de fracturation et colmatage (années - millénaires : le rôle de la dissolution cristallisation sous contrainte

    Directory of Open Access Journals (Sweden)

    Gratier J.-P.

    2011-02-01

    geological context of a faulted area. Finally, as the mechanisms of permeability and strength evolution interact and occur on various scales of time and space, they must be integrated into numerical models, which are briefly discussed. Il est bien connu que les fluides circulent le long des failles, mais il est aussi démontré que les failles se comportent en barrières imperméables. Il faut donc considérer que les failles puissent être successivement des chemins ouverts et fermés. À l’échelle de temps des activités humaines (années à millénaires, l’étude du cycle sismique offre la possibilité de construire un modèle de telles évolutions. Selon ce modèle, la fracturation sismique (ou hydraulique ouvre les chemins des fluides de manière quasi-instantanée le long des failles avec des processus d’amollissement et de fluage post-fracturation. La fermeture de ces chemins de fluide par cicatrisation de la faille est beaucoup plus progressive, associée à un durcissement et une reconstitution de pression des fluides. De tels comportements transitoires ont des conséquences majeures dans les études : de l’évolution de la perméabilité le long des failles, avecapplication à l’exploitation de réservoirs pétroliers et auxstockages de fluides et de déchets; de l’évolution des flux de fluides le long des failles avec application au bilan des échanges et à l’évolution du climat à l’échelle de la terre; du temps de retour des séismes et de la probabilité de leur occurrence. Le but est de comprendre et d’évaluer la cinétique des processus et donc les temps caractéristiques spécifiques des cycles de fracturation et de colmatage. Des résultats d’expériences de laboratoire et d’étude de failles naturelles sont présentés qui montrent comment des processus de dissolution cristallisation sous contrainte peuvent expliquer à la fois les processus de fluage et de colmatage, et la façon dont ils sont associés dans la nature. Les

  15. Mesure et modélisation des contraintes naturelles dans un massif rocheux alpin. Effets de la topographie, de l'anisotropie et des contraintes tectoniques; application au projet de tunnel Maurienne-Ambin.

    OpenAIRE

    Mayeur, Bertrand

    1999-01-01

    Le projet de tunnel de base Maurienne-Arnbin, qui traversera les Alpes sur plus de 50 km de longueur et sous un 'recouvrement de terrain atteignant au maximum 2500 m, pose le problème de la prévision des états de contraintes naturelles dans les massifs rocheux ; le comportement du rocher pendant l'excavation aussi bien que la stabilité de l'ouvrage en dépendent. Pour étudier cette question complexe, nous avons eu recours à plusieurs approches complémentaires. Il s'agit tout d'abord d'une étud...

  16. Évolution des contraintes résiduelles dans la couche de diffusion d’un acier modèle Fe-Cr-C nitruré

    DEFF Research Database (Denmark)

    Jegou, Sébastien; Barrallier, Laurent; Somers, Marcel A. J.

    2011-01-01

    Limiter la fatigue et la corrosion des pièces est possible grâce à une nitruration. Des contraintes résiduelles en découlent. Le rôle de la diffusion du carbone sur le développement de ces contraintes a été étudié sur un acier modèle Fe-3%m.Cr-0.35%m.C.......Limiter la fatigue et la corrosion des pièces est possible grâce à une nitruration. Des contraintes résiduelles en découlent. Le rôle de la diffusion du carbone sur le développement de ces contraintes a été étudié sur un acier modèle Fe-3%m.Cr-0.35%m.C....

  17. Etude des effets du martelage repetitif sur les contraintes residuelles

    Science.gov (United States)

    Hacini, Lyes

    L'assemblage par soudage peut engendrer des contraintes residuelles. Ces contraintes provoquent des fissurations prematurees et un raccourcissement de la duree de vie des composants. Dans ce contexte, le martelage robotise est utilise pour relaxer ces contraintes residuelles. Trois volets sont presentes: le premier est l'evaluation des effets des impacts unitaires repetes sur le champ de contraintes developpe dans des plaques d'acier inoxydable austenitique 304L vierges ou contenant des contraintes residuelles initiales. Dans la deuxieme partie de ce projet, le martelage est applique grace au robot SCOMPI. Les contraintes residuelles induites et relaxees par martelage sont ensuite mesurees par la methode des contours, qui a ete adaptee a cet effet. Dans la troisieme partie, le martelage est modelise par la methode des elements finis. Un modele axisymetrique developpe grace au logiciel ANSYS permet de simuler des impacts repetes d'un marteau elastique sur une plaque ayant un comportement elastoplastique.

  18. Reboiser sous les tropiques

    Directory of Open Access Journals (Sweden)

    Pierlot, R.

    2007-01-01

    Full Text Available To Reafforest in the Tropics. Le sanctuaire de gorilles de Lossi constitue une expérience sur la synergie entre la recherche scientifique et la conservation de la nature. Trois parties prenantes sont impliquées dans un processus de gestion participative: l'Etat congolais, la communauté autochtone représentée par l'association des ayants droits des terres de Lossi et le programme européen sur les écosystèmes forestiers d'Afrique centrale. Une enquête de terrain a été effectuée sur le site de Lossi en 2003; elle avait comme objectif d'étudier les effets générés par la gestion participative et d'identifier les contraintes liées à l'exécution de cette approche participative en milieu réel. Les travaux de recherche sur la primatologie ont abouti à l'habituation des gorilles à la présence humaine, ce qui a conduit à la création d'un tourisme de vision de gorilles de plaine de l'Ouest. Un camp de touristes a été construit, ainsi que l'ouverture de la route d'accès au sanctuaire. Le tourisme a généré des emplois en faveur de la population locale qui est aussi prestataire de contrats sur les travaux de réfection des routes. Une partie des revenus a permis la construction d'un centre de santé intégré. Cependant, les travaux de recherche scientifique et le tourisme ont été ralentis pendant l'apparition de la fièvre hémorragique d'Ebola et pendant les trois épisodes de la guerre civile. La consolidation et le long terme de cette entreprise de cogestion du patrimoine naturel de Lossi consiste en l'établissement d'un plan d'aménagement et de gestion, qui concilie la conservation, le développement rural et la recherche scientifique tout en garantissant une répartition équitable des revenus entre les trois partenaires.

  19. Fatigue in the Presence of Corrosion (Fatigue sous corrosion)

    Science.gov (United States)

    1999-03-01

    7475"-- -’-’.--F AK=13 20 X - __A. • X - MPaVm 10-4 10-3 10-2 10-1 100 10’ f[ HzJ Fig. 7: Influence of frequency for 2024, 6013 and 7475 Flight...Rivetdia Fullriprobability of a randomly selected lap joint having a5.14. cm td Full rivets 4.9m_ .Scenario 1 lead crack was 8/13 and the probability of

  20. Comportement sous polarisation d'un acier dans des solutions simulant des bétons (sans chlorures ) : Etude 2003

    OpenAIRE

    Bouteiller, Véronique

    2004-01-01

    Un acier de précontrainte a été étudié sous polarisation dans des solutions simulant des bétons (sans chlorures). L'acier a été étudié sous quatre états de surface différents (acier tel quel, acier poli, acier rouillé artificiellement et acier rouillé naturellement dans trois solutions différentes simulant des bétons "sain", légèrement carbonaté et "carbonaté". Les courbes potentiodynamiques montrent que la formation d'oxydes et/ou le dégagement d'hydrogène dépendent de la surface de l'acier ...

  1. Contraintes de taille dans les mots composés : quand la phonologie entre en concurrence avec les contraintes morphologiques

    Directory of Open Access Journals (Sweden)

    Villoing Florence

    2012-07-01

    Full Text Available Cette communication porte sur les contraintes phonologiques qui pèsent sur la formation des mots construits dans le cadre théorique de la morphologie lexématique (Anderson 1992, Aronoff 1994, Fradin 2003. En étudiant les données du français, les travaux de Lignon (à paraître, Plénat (2009 & Roché (2003 ont montré que des contraintes de taille étaient à l’œuvre dans plusieurs constructions morphologiques. L’objectif de cet article est d’étudier cette hypothèse sur les mots composés Verbe-Nom du français (Villoing 2009. L’analyse quantitative des données du corpus montre clairement que les verbes des mots composés VN du français sont soumis à des contraintes de taille et doivent répondre au format d’un monosyllabe. La contrainte pèse moins lourdement sur les noms qui parviennent à s’imposer plus facilement que les verbes avec une taille supérieure. Cependant, la majorité des mots composés VN tend à ne pas dépasser trois syllabes (leur format optimal étant de deux ou trois syllabes, révélant ainsi l'influence des contraintes de taille sur le mot composé lui-même. La mise au jour de ces contraintes permet d'expliquer l’absence de certains verbes dans le corpus de composés VN, répondant pourtant bien aux propriétés sémantiques attendues : les verbes construits par affixation (absence de suffixés en -iser, -ifier; très rares cas de préfixés, les verbes du 2ème groupe, les verbes de taille supérieure à trois syllabes. En outre, cet article met au jour un cas de concurrence entre contrainte morphologique et contrainte phonologique au sein d'une construction morphologique, et montre comment la première l'emporte sur la dernière, bien que la contrainte phonologique contraigne fortement le choix du verbe et du nom de base. Il donne également à voir comment la contrainte phonologique parvient néanmoins à influencer le choix de bases sémantiquement peu conformes aux attentes de la règle.

  2. A PERFORMANCE COMO UMA CONTRAINTE NOS TRABALHOS DE SAMUEL BECKETT E GEORGES PEREC

    Directory of Open Access Journals (Sweden)

    Jacques Fux

    2011-04-01

    Full Text Available Este artigo tem como objetivo aproximar as contraintes presentes no livro A vida modo de usar, de Georges Perec, com a performance presente no projeto Quad I+II, de Samuel Beckett. Pensar a performance como uma contrainte é uma forma de unir a literatura sob contrainte com a performance.

  3. Stress-Induced Seismic Anisotropy Revisited Nouveau regard sur l'anisotropie sismique induite par les contraintes

    Directory of Open Access Journals (Sweden)

    Rasolofosaon P.

    2006-12-01

    S-wave polarized in the coordinate planes. The nearly exhaustive collection of experimental data on seismic anisotropy in rocks (considered as transverse isotropic by Thomsen (1986 show that elliptical anisotropy is more an exception than a rule. Since stress-induced anisotropy is essentially elliptical when restricted to transversely isotropic media, as a consequence this work clearly shows that stress can be practically excluded as a unique direct cause of elastic anisotropy in rocks. Ce résumé contient des formules (*** qui ne peuvent s'afficher à l'écran Un principe général esquissé par P. Curie (1894 concernant l'influence de la symétrie sur les phénomènes physiques dit, en langage actuel, que le groupe de symétrie des causes est un sous-groupe du groupe de symétrie des effets. Par exemple, en ce qui concerne l'anisotropie sismique induite par les contraintes, la symétrie la plus complexe présentée par un milieu initialement isotrope, sous contrainte triaxiale, est orthorhombique ou orthotrope, caractérisée par trois plans de symétrie orthogonaux deux à deux (Nur, 1971. À d'autres égards, Schwartz et al. (1994 ont montré que deux modèles de roches très différents, un modèle fissuré et un modèle granulaire faiblement consolidé, conduisent toujours à une anisotropie elliptique quand ils sont soumis à une contrainte uniaxiale. La question posée est la suivante : est-ce que ce résultat est vrai pour tous les modèles de roches ? et, plus généralement, est-ce que les roches initialement isotropes, quand elles sont soumises à une contrainte triaxiale, forment un sous-ensemble bien défini des milieux orthorhombiques ? Sous l'hypothèse d'hyperélasticité isotrope non linéaire du troisième ordre (c'est-à-dire absence d'hystérésis, et existence d'une fonction d'énergie élastique développée au troisième ordre dans les composantes de la déformation, il est démontré que l'anisotropie de l'onde qP induite par les contraintes est toujours

  4. Experimental investigation of the residual stresses of 304L tubular welded joints; Caracterisation des contraintes residuelles sur assemblages soudes tubulaires en acier 304L

    Energy Technology Data Exchange (ETDEWEB)

    Monin, L.; Panier, S.; Hariri, S.; Zakrzewski, D. [Ecole des Mines de Douai, 941, rue Charles Bourseul, BP 10838, 59508 DOUAI Cedex (France); Faidi, C. [EDF-SEPTEN, 12-14, avenue Dutrievoz, 69628 VILLEURBANNE (France)

    2007-07-01

    In the nuclear energy industry, the use of components made of austenitic stainless steel is widely spread, because of its specific thermal properties. The assembly of these pressure vessels and piping by welding processes often requires surface mechanical operations. These operations aim at hardening surfaces and lowering roughness. Nevertheless the main effect of these operations is the occurrence of residual stresses which can have positive or negative effects on the fatigue life. In this study, we focus on the evaluation and relaxation of residual stresses level on AISI 304L austenitic stainless steel tubular welded structures. Some of these rings are base metal rings (which stand as reference), the rest presents a longitudinal and symmetrical Y-weld joint, with or without grinding. Surface residual stresses, and their relaxation, were determined by using the X-ray diffraction method. (authors) [French] L'utilisation de composants en acier inoxydable austenitique, aux proprietes thermiques bien specifiques, est tres courante dans le domaine de la production d'energie nucleaire. Les procedes d'assemblage par soudage de ces equipements sous pression requierent des traitements de parachevement mecanique afin d'ameliorer l'etat de surface et modifier l'etat mecanique en introduisant des contraintes residuelles, qui peuvent avoir une influence sur la duree de vie de la structure. Cette etude porte sur la caracterisation et la relaxation des contraintes residuelles, determinees sur des eprouvettes annulaires specifiques en acier inoxydable austenitique de type 304L, a l'etat brut ou avec des soudures, arasees ou non. La methode de determination utilisee est la diffraction des rayons X. La relaxation de ces contraintes au cours d'essais de fatigue est egalement etudiee. (auteurs)

  5. SOUS LE PAVÉ: LA PLAGE!

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2017-01-01

    around something that could be labeled geologic resonance: The ability of a creative work or an area to bring humans on wavelengths with geology’s ‘deep time.’ When the avant-garde art movement the Situationists used the slogan ‘sous les pavés: la plage!’ the beach was associated with the free natural...... space in contrast to the paved street, which represented the suppressing power of society. But the slogan can also remind us of geology’s omnipresent character. Geology is right at our feet in and below the hard surfaces of the city, and we do not need to visit geological sights to experience geologic...

  6. The energy in all states: data, constraints, stakes; L'energie sous toutes ses formes: donnees, contraintes, enjeux

    Energy Technology Data Exchange (ETDEWEB)

    Balian, R. [Academie des Sciences, 92 - Gif sur Yvette (France); Combarnous, M. [Bordeaux-1 Univ., LEPT-ENSAM, 33 - Talence (France); Lucas, J.; Fauvarque, J.F. [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France); Madet, D. [Electricite de France (EDF), 75 - Paris (France); Bal, J.L. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France); Jourde, P. [CEA Cadarache, GENEC, 13 - Saint-Paul-lez-Durance (France); Tissot, B. [Commission Nationale d' Evaluation, 75 - Paris (France); Leconte, Ph. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares DDIN, 91 - Gif Sur Yvette (France); Doubre, H. [Paris-11 Univ., IN2P3/CNRS, 91 - Orsay (France); Alleau, Th. [Association Francaise de l' Hydrogene, AFH2, 75 - Paris (France); Durup, G. [Mining Research Institute (United States); Le Treut, H. [Ecole Nationale Superieure, 75 - Paris (France); Tubiana, M. [Institut Gustave Roussy, 94 - Villejuif (France)]|[Centre Antoine Beclere, Paris (France); Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France); Lebot, B. [Agence Internationale de l' Energie, 75 - Paris (France); Babusiaux, D. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Saab, A.E. [Electricite de France (EDF), 75 - Paris (France)

    2002-07-01

    This documents brings together papers presented at the physics summer school of august 2001 on the energy. The following topics are discussed: the constraints bound to the physics and the scales, the renewable energies, the future of the nuclear energy and the fossil energies, the energy storage problems, the environmental and sanitary aspects, the energy mastership and economy. (A.L.B.)

  7. Hydrogen cracking and stress corrosion of pipeline steels. Contribution of the cracking mechanisms study to the understanding of the in-service damage and to the definition of a ranking test; Fissuration assistee par l'hydrogene et corrosion sous contrainte des aciers de pipelines. Apports de l'etude des mecanismes de fissuration a la comprehension de l'endommagement de service et a la definition d'un test de classification

    Energy Technology Data Exchange (ETDEWEB)

    Le Friant, D.

    2000-12-19

    This work is based on the study of the cracking of a French oil transmission pipeline protected by a cathodic protection system. The objective is to identify field parameters, which contribute to the cracks propagation, and to assess changes in the operating conditions, which could lead to a mitigation of the phenomenon. We have focused on the study of the micro-mechanisms by means of slow strain rate tests. Then, cyclic loading tests were carried out to investigate cracks propagation mechanisms. Smooth and pre-notched specimens were tested at free and cathodic potential. Hydrogen is responsible for crack advance through changes in the local steels properties. Such effects take place when two phenomenons occur: favourable conditions for hydrogen entry and, a localisation of hydrogen and its effects. In particular, we have shown the essential role of a dynamic loading in promoting hydrogen entry into the steel (especially at the very crack tip). At cathodic potential, hydrogen-related effects are exacerbated by the presence of MnS inclusions which leads to the initiation of internal cracks (HIC) and to a SOHIC-like crack morphology. At free potential, the lesser amount of available hydrogen give localisation-related effects a greater importance. Cracking is then related to a hydrogen-induced SCC mechanism. Three parameters are involved in the field cracking: operating pressure variations, period of over-protection and a sensitive steels microstructure (MnS). Cathodic protection appears to be the most efficient field parameter to mitigate the phenomenon: it requires a better control of the polarisation level. Finally, a ranking test is outlined from the study of the cracking mechanisms. (author)

  8. Study of hydrogen migration produced during the corrosion of PWR reactors fuel cans in zircaloy 4 and zirconia; Etude du transport de l`hydrogene produit lors de la corrosion des gaines d`elements combustibles des reacteurs a eau sous pression dans la zircone et le zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Aufore, L

    1997-12-12

    The corrosion of Zircaloy-4-claddings by water from the primary circuit of nuclear power plant goes hand in hand with the release of hydrogen which penetrates the oxide and then the metal. This work focuses on the mechanisms of hydrogen transport in oxide and in metal. Hydrogen transport in oxide is studied on the basis of corrosion tests performed in the autoclave at 360 deg C. These tests are performed on Zircaloy-4 claddings under different chemical conditions (pure water, and pure water with lithium hydroxide). The distribution of hydrogen in oxide film is measured by SIMS. Hydrogen profiles in the oxide are dependent on the oxide microstructure and vary with oxidation time. These observations are confirmed by experiments in which some samples, previously oxidized in the autoclave, are immersed in heavy water. In the oxide layer, two zones are observed: one external porous zone and one internal dense zone. Deuterium diffusion coefficients in dense oxide are determined using SIMS profiles and Fischer diffusion model. Hydrogen transport in metal is also studied by means of gas-phase permeation experiments. These are set up at different temperature (400-500 deg. C) and under different hydrogen pressures and make it possible to determine the hydrogen diffusion coefficients in a Zircaloy-4 cladding under experimental conditions. All these results lead us to discuss of hydrogen transport evolution in cladding during oxidation. A model taking into account hydrogen transport in oxide and in metal, and the hydrides precipitations is proposed. (author) 110 refs.

  9. Aphasie : Contraintes vs Gouvernement, le cas des clusters

    Directory of Open Access Journals (Sweden)

    Prince Typhanie

    2012-07-01

    Full Text Available L'objet de ce travail est de comprendre les processus phonologiques qui structurent le langage : pathologique ou non. Notre approche apparie phonologie et aphasiologie. Nous proposons ici une analyse de ces processus phonologiques à travers l'étude des groupes consonantiques dans les structures syllabiques dont ils dépendent. Le cas des clusters apparaît essentiel dans cette problématique. Cet objet n'est que trop peu exploité dans les travaux aphasiologiques alors qu'il s'avère central dans les approches phonologiques par les problèmes représentationnels qu'il pose : relations ou absence de relations entre les consonnes, hétérosyllabicité ou ambisyllabicité. Notre étude prend en compte : - une dimension segmentale : à travers la notion de complexité, - une dimension syllabique : par les relations de gouvernement imposées sur les représentations phonologiques. Nous postulons que ce n'est qu'en considérant l'interrelation de ces dimensions que l'on peut produire une explication des désordres phonologiques observés en pathologie et montrer que des régularités émergent. Dans cet article, nous exposons les traitements proposées à l'aphasie à travers deux cadres phonologiques : la Théorie de l'Optimalité [OT] et la Théorie des Contraintes et des Stratégies de Réparation [TCSR]. Il s'agit d'observer les apports et limites rencontrés par ces modèles. Ensuite, à partir de la Phonologie du Gouvernement, cadre dans lequel nous nous situons, depuis [KLV : 1985] jusqu'à [Scheer : 2010], nous analysons les données et exposons une explication des phénomènes tant au niveau segmental que syllabique. L'étude est basée sur un échantillon de 15 aphasiques (Broca, Wernicke, Conduction de l'unité Neuro- Vasculaire du CHU de Nantes : tous souffrent d'une aphasie consécutive à une lésion cérébrale. Les données ont été récoltées au maximum 72h après le traumatisme à partir d'un protocole expérimental destiné

  10. Palatability of sous vide processed chicken breast.

    Science.gov (United States)

    Turner, B E; Larick, D K

    1996-08-01

    The influences of brine composition, internal temperature, heating rate, and storage periods up to 28 d on flavor, texture, and color of sous vide processed chicken breast were evaluated. Pectoralis major muscles containing water and sodium chloride, with or without sodium lactate, were browned and vacuum packaged. Sous vide processing was by fast or slow heating to an internal temperature of 77 or 94 C. Product was evaluated after 0, 14, and 28 d storage at 4 C. Quality was evaluated by gas chromatographic analyses of flavor volatiles, shear, color, and sensory panels. Incorporation of sodium lactate into brine did not influence oxidative stability (as measured by headspace gas chromatography) or sensory warmed-over flavor. Presence of sodium lactate did result in enhanced fresh roasted or meaty and saltiness sensory scores as well as a more yellow color. The more rapid heating rate decreased sulfur-containing compounds and did not influence other volatile concentrations. Products processed to 94 C were less juicy, less tender, and contained higher quantities of alcohols and hydrocarbons than those processed to 77 C. Storage resulted in a decline in fresh roasted or meaty flavor note and an increase in warmed-over flavor note and quantities of alcohols, aldehydes and ketones, hydrocarbons, and total headspace volatiles.

  11. Tambaqui (Colossoma macropomum sous vide: characterization and quality parameters

    Directory of Open Access Journals (Sweden)

    Fabiane de Cássia Pontes Ramos

    2016-02-01

    Full Text Available The objective of this study was to evaluate the microbiological, physical and physico-chemical quality parameters of sous vide preparation of pen-reared tambaqui (Colossoma macropomum. To prepare the tambaqui sous vide, 200 g of fillet, 50 g of basil sauce (1:4 fish fillet:sauce ratio and 10 mL of 5% sodium lactate were used. The product was then vacuum-packaged, pasteurized at 65 ºC for 12.5 min and refrigerated. The presence of Salmonella spp., sulfite-reducing Clostridium and Listeria monocytogenes was not detected in the samples analyzed. The coliform count at 45 ºC and coagulase-positive staphylococci were below the limit (103 permitted by the law in vigor. Water retention capacity and chloride content analyses revealed that the tambaqui fillet differed significantly (P<0.05 from the sous vide because of the addition of basil sauce. The total volatile basic nitrogen (TVB-N and thiobarbituric acid reactive substances (TBARS content of the fillet and sous vide were below the limits established by the law, indicating good quality. The lightness (L* and yellow color (b* of the fillet and the sous vide did not differ significantly (P>0.05, but the red color (a* decreased in the sous vide, which is related to the addition of basil sauce. The chroma (C* and hue angle (ho differed significantly (P<0.05, and the fillet samples were lighter in color, whereas the sous vide was characterized by yellow color. The n-6/n-3 ratios found for the fillet and the sous vide are within the recommended values, which is important for human metabolism. The fillet and sous vide also had high calcium, zinc, magnesium and potassium concentrations. It is concluded that tambaqui sous vide is a good source of nutrients, rich in fatty acids and minerals essential for human health.

  12. Nutritional quality of sous vide cooked carrots and brussels sprouts.

    Science.gov (United States)

    Chiavaro, Emma; Mazzeo, Teresa; Visconti, Attilio; Manzi, Chiara; Fogliano, Vincenzo; Pellegrini, Nicoletta

    2012-06-13

    Phytochemicals (carotenoids, phenolic compounds, and ascorbic acid) and antioxidant capacity (measured by TEAC, FRAP, and TRAP assays) were evaluated on carrots and Brussels sprouts sous vide processed and then stored refrigerated for 1, 5, and 10 days and compared with the corresponding raw and oven-steamed products. Data showed that sous vide cooked carrots had higher amounts of carotenoids, phenolic compounds, and ascorbic acid than steamed products, and only a slight decrease of phenolic compounds was recorded during sous vide storage. Contrasting results were obtained on sous vide processed Brussels sprouts: higher carotenoid amounts and TEAC and TRAP values and lower phenolic compounds, ascorbic acid, and FRAP values were exhibited by sous vide in comparison with steamed samples. Phytochemicals and TAC also decreased during Brussels sprout sous vide storage with the exception of carotenoids. The results of this study demonstrated that sous vide preparation can preserve and/or enhance the nutritional quality of carrots, which remain a good source of carotenoids also after long refrigerated storage, whereas the same treatment could be recommended as an alternative to oven-steaming in the preparation of Brussels sprouts for short-term maintenance to avoid a large ascorbic acid depletion.

  13. Contribution a l'etude du comportement en fatigue des aciers inoxydables 13%Cr-4%Ni: Contraintes residuelles de soudage et transformation sous contrainte de l'austenite de reversion

    Science.gov (United States)

    Thibault, Denis

    The objectives of the present study are to characterize some of the main parameters affecting fatigue behaviour of 13%Cr-4%Ni martensitic stainless steels used for hydraulic turbines manufacturing. Two aspects are studied: the residual stresses left after autogenous welding of these steels and the stress-assisted transformation of the reformed austenite contained in this alloy. The residual stresses induced by welding were characterized by four different methods: the hole-drilling method, X-ray diffraction, neutron diffraction and the contour method. The state of stress was characterized in two different joints geometries, both using 41ONiMo weld filler metal. The characterization was made before and after post-weld heat treatment. A stress distribution completely different of the stress distribution commonly found in structural steels was measured. Triaxial compression was found in the last bead with a maximum value of approximately 400 MPa. Tensile stress was measured around the heat-affected zone and just below the last weld layer. The low temperature martensitic transformation occuring during weld cooling (˜300°C) explains this unusual stress distribution. The results also showed that the post-weld heat treatment commonly used in the industry is efficient in lowering residual stresses. A maximum stress of about 150 MPa was found after heat treament. The austenite formed during this post-weld heat treatment is mechanically unstable. The results presented in this thesis show that after fatigue crack propagation testing, all the reformed austenite found near the fracture surface has transformed to martensite under cyclic stress loading. These measurements made by X-ray diffraction are confirmed by low-cycle fatigue tests showing that the reformed austenite found in this alloy transforms gradually to martensite during strain cycling. The transformation is completed after 100 cycles. The fatigue crack growth behaviour of the tested alloys does not seem to be influenced by this phenomenon occuring at all values of stress intensity factor. The practical implications of this work on fabrication and repair of hydraulic turbines made of 13%Cr-4%Ni are also discussed in this thesis. Keywords: martensitic stainless steel, fatigue, residual stress, welding

  14. Geothermal power generation. Bruchsal and Soultz-sous-Forets; Geothermische Stromerzeugung. Bruchsal und Soultz-sous-Forets

    Energy Technology Data Exchange (ETDEWEB)

    Mergner, Hanna; Eggeling, Lena; Koelbel, Thomas; Muench, Wolfram [EnBW Energie Baden-Wuerttemberg AG, Karlsruhe (Germany). Forschung und Innovation; Genter, Albert [G.E.I.E EMC, Soultz-sous-Forets (France)

    2012-11-01

    For more than 100 years geothermal heat and power production has been an important part of the share of energy in areas with outstanding geological conditions. Also under the typical conditions in Middle Europe the geothermal energy gains in importance. In the following, we focus on two geothermal power plants located in the Upper Rhine Valley: Soultz-sous-Forets and Bruchsal, commissioning in 2008 and 2009. By comparing both sites the big difference lies in the technology used for extracting hot thermal water: while the German plant in Bruchsal has access to a natural hot water source in a relatively low depth of 2,000 to 2,500 m, the French sister project performs by chemical and hydraulic stimulation a man-developed reservoir as energy source in a depth of 5,000 m. The plant in Soultz consists of four wells with a wellhead temperature of 165 C. In Bruchsal a typical geothermal doublet is used where the thermal brine has a wellhead temperature of about 124 C. Also the power plants show significant differences. On both locations binary-cycles are responsible for power generation, but in Soultz a regular Organic-Rankine-Cycle (ORC) is installed, in Bruchsal a Kalina-Cycle is in operation. What both projects have in common is their research character. Corrosion, the prevention of scalings and the optimization of all plant's components are in the focus of many research projects. Even so the electricity generation costs can already compete with other renewable energies by today, the reliable availability of geothermal power plants and the reduction of the power generation costs to 10 ct/kWh in the next decade is the current goal of the entire research effort. (orig.)

  15. Calculateur de jeux sous-redresseurs

    OpenAIRE

    Llatser Nieto, Gloria

    2013-01-01

    Le sujet de ce stage concerne le compresseur haute pression d’un moteur de forte puissance (MFP), le GE90-115B. Le rôle d’un CoHP est d’élever la pression du flux d’air primaire en transformant l’énergie cinétique dû à la rotation du rotor en énergie de pression. De cette façon, une pression suffisante à l’entrée de la chambre de combustion permet d’avoir un bon rendement pour le moteur. De part son architecture, les CoHP autorisent une recirculation sous les redresseurs de chaque étage. Cett...

  16. La base sous-marine de Bordeaux, sous le béton la culture

    Directory of Open Access Journals (Sweden)

    Mathieu Marsan

    2012-06-01

    Full Text Available Active à peine plus d’un an pendant l’Occupation, la base sous-marine de Bordeaux cristallise encore les souvenirs douloureux des heures sombres du Port de la Lune. Le bunker attire pourtant depuis les années 1960 des artistes, cinéastes, plasticiens et musiciens fascinés par l’esprit du lieu. Institutionnalisée au début des années 1990, la base sous-marine devient un espace dédié au nautisme avant d’être consacrée à l’art contemporain au début du XXIe siècle. Aujourd’hui au cœur du projet d’aménagement des bassins à flot du quartier de Bacalan, la base sous-marine questionne et intrigue ses visiteurs sur son passé, mais aussi – et surtout – sur son avenir.Build during the German occupation, the submarine base of Bordeaux active during hardly more than a year still crystallizes the painful memories of the dark hours of the « Port de la Lune ». Nevertheless, the bunker attracts artists, film-makers, visual artists and musicians fascinated by the spirit of the place since the 1960’s. Institutionalized at the beginning of 1990’s, the submarine base became a space dedicated to the yachting before contemporary art at the beginning of the XXIth century. Nowadays at the heart of the project of redevelopment of the wet docks in the urban area of Bacalan, the submarine base questions and intrigues its visitors on its past, but also – and especially – on its future.

  17. Fonctions de Valeurs Distribuées sous Contraintes de Communication pour la Coordination Décentralisée d'Agents Décisionnels

    OpenAIRE

    Matignon, Laëtitia; Jeanpierre, Laurent; Mouaddib, Abdel-Illah

    2012-01-01

    National audience; De récents travaux relatifs aux modèles décisionnels exploitent les interactions locales et la coordination pour résoudre les processus décisionnels de Markov partiellement observables. Dans cet article, nous proposons une approche basée sur ces techniques de résolution orientée-interaction et motivée par une application réelle d'agents décisionnels décentralisés pour l'exploration et la cartographie d'un environnement inconnu. Cette approche utilise des fonctions de valeur...

  18. Caractérisation physique, chimique et microbiologique de trois sols acides tropicaux du Rwanda sous jachères naturelles et contraintes à leur productivité

    Directory of Open Access Journals (Sweden)

    Culot M

    2009-01-01

    Full Text Available Physical, chemical and microbiological characterization of three tropical acidic soils of Rwanda under natural fallows and productivity constraints. Three acidic soils of highland (HL, middle land (ML and lowland (LL from Rwanda were sampled respectively in the experimental stations of Gakuta, Tonga and Cyabayaga for a physical, chemical and microbiological characterization in order to determine their productivity constraints. Soils are strongly acidic in the HL and ML (pH 4.1 and 4.7 and moderately acidic in LL (pH 5.5. The rate of total organic carbon (Corg is acceptable in Gakuta (4.5%, but decreases with altitude. The total nitrogen (Ntot, the phosphorus and the effective cation exchange capacity follow the same trend, their levels remaining nevertheless weak. Base saturation and Bray2-P content are weak in the HL and ML, but also they are negatively correlated with Corg content. The Al3+ ion occupies 32 and 18% of the exchange complex at Gakuta and Tonga, and is non-existent in Cyabayaga soils. Carbon microbial biomass (Cmic : Corg and nitrogen microbial biomass (Nmic : Ntot ratios indicate a weak mineralization/immobilization rate in the highly acidic soils, and are positively correlated with soil pH. Cmic : Nmic ratio values obtained indicate a soil microbial population dominated by fungi, which predicts a poor organic matter (OM quality. The small proportion of the assimilate carbon fraction at Gakuta (5% of Corg testifies also to the OM poor quality. Basal respiration rate is very low (0.30 - 0.37 μg CO2 .h-1.g-1. The addition of glucose for the substrate inducedrespiration has considerably stimulated the metabolic activity, which results in low values of respiratory activation quotient(QR = 0.4-0.5. Dehydrogenase and acidic phosphatase activities are very low but positively correlated with Corg. The soil acidity remains the principal constraint to land productivity in the HL and ML regions while low soil OM and N contents would constitute a limitation in LL zone if appropriate land management practices are not used.

  19. Estimation robuste de paramètres sous contraintes, par algorithmes de type primal-dual. Application en astromètrie.

    Science.gov (United States)

    Bougeard, M. L.

    In recent years, robustness is one problem that has been given much attention in statistical literature. While it is now clear that no single robust regression procedure is best, the L1 and the Huber-M estimators are currently attracting a considerable attention when the errors have a contaminated Gaussian distribution. Nevertheless, they cannot be expressed analytically. So, finding efficient algorithms to produce them in the case of large data sets is still a field of active research. In this paper, the author first discusses the early contribution of Laplace and others to the L1 problem. Then, he presents new algorithms based on the Spingarn Partial Inverse-proximal approach that takes into account both primal and dual aspects of the M-estimation problem. It is shown how the method can be easily extended to handle constrained problems. The result is a family of highly parallel algorithms attractive for large scale problems. Astrometrical applications are considered.

  20. Multi variable control of a switched ignition device: efficiency improvement under various constraints; Commande multivariable d`un moteur a allumage commande: Amelioration du rendement sous differentes contraintes

    Energy Technology Data Exchange (ETDEWEB)

    Chaumerliac, V.

    1995-03-09

    Spark-ignition engine control needs substantial improvement for various reasons: a non-linear and multivariable process, the strictness of anti-pollution constraints, the necessity of fuel economy, the variable running conditions, the aging, the reliability and the cost. The improvement of engine efficiency will be involved in this context and with the pollution constraints. This work develops a system approach and its philosophy is based on a suitable description of the main dynamics. A compartmentalized model of a spark-ignition engine and the dynamic of the vehicle is presented. The aim of this modeling is to have a good representativeness in transients and to describe the behavior of the outputs useful for control. The multivariable control is split in two independent systems. The first one controls the spark advance control to obtain the maximum torque. The second one controls the throttle and the electronic fuel injection device to have lower pollutant emissions. The spark advance closed loop control uses information measured with either a cylinder pressure sensor or a torque sensor. These studies have achieved to an adaptive tuning on engine bench. A new actuator, the electronic throttle control, can provide a higher degree of precision for the fuel/air ratio regulation system, particularly during fast accelerations and decelerations. An intake manifold pressure control is developed to coordinate the air and fuel flows. A delay strategy and a simple compensation of fuel supply dynamics allow to obtain good results on engine bench. Uncoupling the acceleration pedal and the throttle command is a promising way to improve engine efficiency and reduce exhaust emission during transient phases. (author) 59 refs.

  1. Effet des contraintes hydrique et saline sur la germination de quelques acacias africains

    OpenAIRE

    Ndour, P.; Danthu, P.

    1998-01-01

    Notre étude a porté sur la germination de neuf espèces ouest africaines du genre #Acacia$ originaires de zones bioclimatiques contrastées (#Acacia albida$, #A. dudgeoni$, #A. ehrenbergiana$, #A. nilotica adansonii$, #A. nilotica tomentosa$, #A. raddiana$, #A. senegal$, #A. seyal$ et #A. sieberiana$) soumises à une contrainte saline ou hydrique simulée par apport, dans l'eau d'imbibition des graines, de chlorure de sodium (de 0 à 40 g/l, correspondant à une pression osmotique de 0 à -2,4 MPa),...

  2. Corrosion protection

    Science.gov (United States)

    Brown, Donald W.; Wagh, Arun S.

    2003-05-27

    There has been invented a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of iron, steel or other metal to be treated. In the presence of ferrous ions from the iron, steel or other metal, the slurry reacts to form iron phosphates which form grains chemically bonded onto the surface of the steel.

  3. Corrosion Engineering.

    Science.gov (United States)

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  4. Corrosion sensor

    Science.gov (United States)

    Glass, Robert S.; Clarke, Jr., Willis L.; Ciarlo, Dino R.

    1994-01-01

    A corrosion sensor array incorporating individual elements for measuring various elements and ions, such as chloride, sulfide, copper, hydrogen (pH), etc. and elements for evaluating the instantaneous corrosion properties of structural materials. The exact combination and number of elements measured or monitored would depend upon the environmental conditions and materials used which are subject to corrosive effects. Such a corrosion monitoring system embedded in or mounted on a structure exposed to the environment would serve as an early warning system for the onset of severe corrosion problems for the structure, thus providing a safety factor as well as economic factors. The sensor array is accessed to an electronics/computational system, which provides a means for data collection and analysis.

  5. Étude de l'état de contrainte du sol et des organes de travail des ...

    African Journals Online (AJOL)

    SARAH

    30 déc. 2013 ... whose value is a function of depth work will contribute significantly to the design of optimal TMAO with wear .... plus grande, et l'image du champ de contrainte observée .... d'augmentation de la résistance à la traction lors du.

  6. Sous vide processed foods: are they safe for the elderly?

    Science.gov (United States)

    Briley, M E

    1992-01-01

    Demographic trends and market analyses indicate that Americans' interest in convenience foods that are nutritious, safe, and high quality will influence the food industry into the next century. The increase in individuals over 55 plus working women, and the changing family have caused the food industry to develop a new generation of foods. One of the processes, sous vide, is an advanced method where fresh foods are vacuum sealed in impermeable plastic, cooked at low temperature in circulating water, and chilled and held at refrigerator temperature for up to three weeks. Nutritionists and food scientists have concerns about the food safety of sous vide products and the possible increase in food borne illnesses. Continued research is needed for the food industry to deliver safe, nutritious foods, particularly to the elderly.

  7. L’algoculture et ses contraintes géographiques en Chine

    Directory of Open Access Journals (Sweden)

    Sophie Litzler

    2012-02-01

    Full Text Available La production aquacole mondiale a un taux de croissance annuel moyen de 6,2 % (2003-2008. La production des végétaux marins suit cette tendance avec 15,8 millions de tonnes d’algues cultivées. La Chine est le premier cultivateur mondial avec 10 millions de tonnes mais en 2008 elle a signalé une baisse de 13 % de sa production aquacole. Cet article souhaite montrer en quoi de nouvelles contraintes géographiques peuvent limiter le développement de l’algoculture malgré le grand potentiel de la filière. Nous présenterons un état des lieux mondial de cette activité puis une typologie de ces contraintes. Nous illustrerons cet axe de recherche par des études de cas sur la Chine.The global aquaculture production has an average annual growth rate of 6.2 per cent (2003-2008. The production of marine plants follows this trend with 15.8 million tons of seaweed farmed. China is the first world farming country with 10 million, tons but in 2008 it reported a 13 per cent drop in its production. Based on this observation, this article intends to show the geographical restrictions that may limit the development of seaweed farming. We shall present an overview of this activity on a global scale then we shall expose a typology of these restrictions. Finally we shall illustrate this research with several case studies.

  8. Corrosion in airframes

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    The introductory chapter provides a brief reference to the issue of corrosion and corrosion damage to aircraft structures. Depending on the nature and dimensions of this non uniformity, three different categories of corrosion are defined: uniform, selective and localized corrosion. The following chapters present the forms of corrosion that can occur in three defined categories of corrosion. Conditions that cause certain types of corrosion in various corrosive environments are discussed. Examp...

  9. CORROSION IN AIRFRAMES

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    The introductory chapter provides a brief reference to the issue of corrosion and corrosion damage to aircraft structures. Depending on the nature and dimensions of this non uniformity, three different categories of corrosion are defined: uniform, selective and localized corrosion. The following chapters present the forms of corrosion that can occur in three defined categories of corrosion. Conditions that cause certain types of corrosion in various corrosive environments are discussed. Examp...

  10. Sous Vide Teknolojisinin Geleneksel Yemeklerimize Uygulanması

    OpenAIRE

    Topal, Şeminur; Pala, Mehmet; Saygı, Birol

    2015-01-01

    Increasing consumer demands for ready-to eat meals has resulted in the improvement of “sous vide” or vacuum packaging technology followed by processing in-pack. “Çoban Kavurma” was the first meal processed, in the application experiments of this technology to Turkish traditional dishes. After processing and during the cold storage (4 oC); the sensorial, microbiological, physical and chemical qualities were determined periodically. The results showed that; a stable state on the product...

  11. L’adaptation pour le sous-titrage

    OpenAIRE

    2014-01-01

    Rapide tour d’horizon du monde du sous-titrage pour présenter les différentes facettes de la profession, les principaux enjeux et difficultés d’une traduction qui doit faire cohabiter le texte avec les dialogues originaux. Le but étant de faire prendre conscience au public cinéphile et aux différents acteurs du monde de l’image de l’importance de l’adaptation cinématographique. Vuelo de pájaro sobre el mundo del subtitulado con el objeto de presentar las diferentes facetas de la profesión,...

  12. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  13. Dans le ventre du Léviathan. La science du droit constitutionnel sous le national-socialisme

    Directory of Open Access Journals (Sweden)

    Michael Stolleis

    2006-04-01

    Full Text Available Dans cet article Michael Stolleis s’intéresse au devenir de la science du droit constitutionnel sous le régime national-socialiste. L’intérêt de la question dépasse la simple curiosité historique, car elle concerne une discipline de la science juridique centrale à tout État démocratique. Partant des attaques contre le positivisme juridique qui émergent au cours de la République de Weimar, l’article s’ouvre sur une typologie des groupes qui constituent l’Union des professeurs de droit public. Stolleis montre l’affaiblissement progressif des « positivistes » à la faveur des groupes à l’idéologie plus autoritaire et antidémocratique. Cette première typologie des forces en présence permet ensuite d’analyser plus finement les différentes attitudes face à la mise en place du régime national-socialiste – allant de l’émigration (extérieure ou intérieure à la collaboration, en passant par le retrait vers des domaines de la pensée juridique moins directement exposés politiquement. S’intéressant au destin de la discipline plutôt qu’aux devenirs individuels, Stolleis constate l’effacement progressif du droit constitutionnel face à un pouvoir n’acceptant aucune contrainte, aucune restriction. Au point que le silence des représentants de cette discipline semble total après 1938. Enfin, l’article se conclut sur un appel à l’étude historique de la période, d’autant plus nécessaire que l’immédiat après-guerre fut marqué par l’occultation des faits et la volonté de laisser le passé être le passé.

  14. Composes inter-halogenes sous pression: etude des transformations structurales dans le monobromure d'iode sous forme dense

    Science.gov (United States)

    Bouchard, Alexandre

    La famille des composes halogenes et inter-halogenes representent des solides moleculaires adoptant des phases denses communes avec des solides moleculaires diatomiques comme l'azote et l'hydrogene. Parmi les transformations structurales et electroniques induites sous haute pression et observees dans ces solides, on note, entre autres, la dissociation moleculaire et la metallisation. De plus, l'etude des phases denses de l'iode a permis recemment l'observation d'une structure cristalline possedant une modulation dite incommensurable, c'est-a-dire une modulation possedant une periodicite differente de celle de la structure cristalline, jetant ainsi une lumiere nouvelle sur le processus de dissociation moleculaire dans les solides halogenes. Dans ce memoire, on propose d'etudier les changements structuraux dans monobromure d'iode (IBr), un compose inter-halogene possedant des proprietes structurales semblables a celles de deux composes halogenes, soit l'iode (I 2) et le brome (Br2) sous leur forme solide. Des experiences de diffraction des rayons X de poudres en utilisant un rayonnement synchrotron ont ete realisees a temperature ambiante sur l'IBr en variant la pression jusqu'aux environs de 60 GPa. La nature chimique particuliere du compose IBr a necessite la mise au point de techniques de chargement d'echantillon destinees a preserver l'integrite chimique de la substance utilisee. On rapporte egalement l'observation d'une phase de l'IBr presentant une modulation incommensurable. Les phases observees dans l'IBr permettent d'etablir des paralleles avec les phases denses rapportees dans I2 et Br2 par le biais d'un modele phenomenologique decrivant la sequence structurale des solides halogenes sous forme condensee.

  15. Safety evaluation of sous vide-processed ready meals.

    Science.gov (United States)

    Nissen, H; Rosnes, J T; Brendehaug, J; Kleiberg, G H

    2002-01-01

    To assess survival, growth and toxin production of spore-forming bacteria in sous vide products exposed to a relatively high heat treatment. During a three-year period, 2,168 sous vide-processed, commercially available ready-made meals with a shelf life of 3-5 weeks were examined. The products were stored at 4 degrees C for the first 1/3 and at 7 degrees C for the remaining 2/3 of their shelf life period. Three-fourths of the samples had less than 10 bacteria per gram the day after production, and none had more than 1,000. Similar numbers were found at the end of the shelf life when stored as described above. At abuse temperature (20 degrees C), the number of bacteria increased to 10(6)-10(7) cfu g(-1) 7 d after production. A total of 350 isolates of Bacillus spp. were collected, but no Clostridium strains were detected. Only 11 of the 113 tested strains were able to grow at 7 degrees C in broth, and none of the psychrotrophic strains were able to produce substantial amounts of toxins causing food poisoning. The health risk of these products is small as long as the temperature during storage is low. For microbial testing of the end products, traditional plating will suffice.

  16. Calcul des contraintes thermiques induites lors d'une trempe superficielle par laser de puissance

    Science.gov (United States)

    Li, J.; Castex, L.

    1998-03-01

    A distribution model of the internal thermal stress for the material surface scanned by laser with arbitary power distribution is reduced in terms of thermal elastic theory of continuous medium and is based on the regard radiation surface as semi-infinity. Because of introducing to concept of imaginary sources, the result acquired by reduced can be used to simulate the thermal stress distribution of practical parts with parts with parallelepipedic boundary. En s'appuyant sur les résultats analytiques obtenus dans le cas élastique, nous établissons les formules permettant de calculer le champ des contraintes thermiques induit par une irradiation en balayage par un faisceau laser ayant une répartition spatiale d'énergie quelconque. La surface du matériau est considérée semi infinie et la température induite quasi stationnaire. Nous introduisons ensuite une notion de source virtuelle pour que les résultats théoriques puissent simuler un cas pratique.

  17. Corrosion Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Corrosion Testing Facility is part of the Army Corrosion Office (ACO). It is a fully functional atmospheric exposure site, called the Corrosion Instrumented Test...

  18. Int\\'egration de contraintes cin\\'ematiques pour le calcul de l'orientation optimis\\'ee de l'axe de l'outil en usinage 5 axes Optimisation of tool axis orientation in 5 axis machining taking into account kinematical constraints

    CERN Document Server

    Lavernhe, Sylvain; Lartigue, Claire; 10.1051/meca:2007064

    2010-01-01

    Apr\\`es avoir d\\'etaill\\'e les principales difficult\\'es li\\'ees \\`a l'usinage 5 axes UGV, nous pr\\'esentons un mod\\`ele de repr\\'esentation des trajectoires 5 axes sous forme surfacique permettant de prendre en compte des contraintes g\\'eom\\'etriques et cin\\'ematiques. Ce mod\\`ele est int\\'egr\\'e dans d'optimisation des trajets 5 axes afin de maximiser la productivit\\'e tout en garantissant la qualit\\'e g\\'eom\\'etrique attendue. Un cas d'application est d\\'etaill\\'e, illustrant la modification de l'orientation de l'axe de l'outil afin d'am\\'eliorer le comportement cin\\'ematique des axes lors du suivi des trajectoires. After presenting the main difficulties related to machining 5 axes machining within the context of HSM, we present a surface model of 5-axis trajectories allowing taking into account geometrical and kinematical constraints. This model is integrated in an optimization scheme in order to maximize the productivity while ensuring the expected geometrical quality. A case of application is detailed, ...

  19. Fabrice d’Almeida, La vie mondaine sous le nazisme

    OpenAIRE

    Rival, Sebastien

    2012-01-01

    La mondanité est un concept rarement mobilisé dans les études historiques, moins encore quand on s’intéresse à la période nazie. Fabrice d’Almeida se propose de combler cette lacune et justifie son entreprise de deux manières. D’une part, il regrette que les historiens aient longtemps passé sous silence cet aspect du nazisme, au prétexte de se préserver, après la Shoah, de toute complaisance à l’égard de ce régime. D’autre part, il inscrit son projet dans le renouveau de l’histoire culturelle...

  20. Caractérisation non destructive par courants de Foucault de l'état de contraintes dans les matériaux magnétiques

    OpenAIRE

    DAHIA, Abla; Berthelot, Eric; Le Bihan, Yann; DANIEL, Laurent

    2014-01-01

    L'objectif de ce travail est d'étudier une technique de caractérisation de l'état de contraintes dans les matériaux magnétiques par la méthode du contrôle non destructif par courants de Foucault. Cette technique exploite l'effet de la contrainte sur le comportement magnétique d'un matériau magnétique. Un modèle multi-échelle a été utilisé pour décrire le comportement magnétique d'un matériau magnétique soumis à une contrainte mécanique. Un modèle éléments finis 3D a été développé pour modélis...

  1. Proprietes optiques des heterostructures contraintes de type II Ga(x)In(1-x)P/InP

    Science.gov (United States)

    Chennouf, Abderrahim

    Cette these porte sur l'etude des proprietes optiques des heterostructures contraintes GasbxInsb1-xP/InP deposees sur des substrats d'InP avec une concentration de Ga inferieure a 20%. Ces heterostructures, fabriquees a l'Ecole Polytechnique de Montreal par la technique d'epitaxie en phase vapeur aux organo-metalliques (E.P.V.O.M), sont composees de barrieres de GasbxInsb1-xP contraintes en tension biaxiale (inferieure a 1%) et de puits d'InP non contraints. Nous avons etudie l'effet des contraintes sur les transitions observees dans les spectres d'absorption optique et de photoluminescence des structures volumiques contraintes GasbxInsb1-xP/InP deposees sur le meme substrat. Auparavant, nous nous sommes assures de la tres bonne qualite des echantillons en correlant les parametres structuraux obtenus par les mesures de rayons X et les spectres de photoluminescence. Ces resultats nous ont permis d'entamer l'etude des heterostructures en question. L'utilisation du modele de Bastard-Marzin, base sur l'approximation de la masse effective et dans lequel les effets des contraintes sont pris en compte, nous a permis de calculer les niveaux confines et de deduire l'alignement de bandes pour ce systeme qui est crucial pour la comprehension des proprietes optiques et electroniques. Les resultats trouves montrent que les electrons sont confines dans les puits d'InP et les trous legers dans les barrieres de GasbxInsb1xP formant ainsi une configuration de bande de type II, tandis que les trous lourds sont dans les puits. Cette delocalisation spatiale des porteurs confines entraine des proprietes particulierement interessantes que nous avons mis en evidence en combinant differentes techniques optiques telles que l'absorption optique, la photoluminescence en regime continu et en excitation. Nous avons montre que dans le cas des super-reseaux, la transition qui apparai t dans les spectres de photoluminescence a plus basse energie que celle de l'exciton libre est associee a la

  2. La physique des tas de sable Description phénoménologique de la propagation des contraintes dans les matériaux granulaires

    Science.gov (United States)

    Claudin, Ph.

    ène : les forces que l'on applique à un empilement sont majoritairement supportées et véhiculées par une fraction seulement des grains, qui forment alors de véritables chaînes de force ou voûtes. Il en découle par exemple que le profil de pression sous un tas de sable dépend de la manière dont celui-ci a été construit. Pour décrire quantitativement ces effets, nous avons proposé une relation phénoménologique de friction entre les voûtes. Les équations différentielles qui en résultent sont de type hyperbolique. Cela signifie en particulier qu'il existe des lignes privilégiées de propagation appelées caractéristiques, que nous avons fait coïncider avec ces voûtes. Ces modèles reproduisent bien les données expérimentales, et permettent entre autres d'expliquer la présence d'une dépression au centre du tas lorsque celui-ci est construit avec un entonnoir. Ils améliorent également les prédictions du modèle de Janssen pour le silo. Nous nous sommes aussi intéressés aux fluctuations de ces contraintes, et nous avons mis en évidence le caractère fragile i.e. réarrangeant d'un empilement granulaire. Ceci a particulièrement été étudié au sein d'un modèle scalaire très simple qui permet de visualiser les variations de la structure interne d'un système granulaire et les changements dans la distribution des forces qui en résulte.

  3. La contrainte des vingt-quatre heures. Le quotidien dans trois microbiographies contemporaines

    Directory of Open Access Journals (Sweden)

    Frances Fortier

    2007-06-01

    Full Text Available Dossier/Issue: 1 - Raconter le quotidien aujourd'hui - L'article met en regard trois biofictions contemporaines qui relatent une journée particulière de la vie d'un écrivain : André Gide. Vendredi 16 octobre 1908 de Patrick et Roman Wald Lasowski (1992, Proust. Samedi 27 novembre 1909 d'Alain Buisine (1991 et Valéry. Jeudi 10 juin 1927 de Richard Jorif (1991. Au-delà de la contrainte des vingt-quatre heures, ces mises en récit du quotidien de l'autre, factices il va sans dire, font jouer les diverses dimensions du terme - la temporalité, la récurrence et l'insignifiant - par le biais de procédés énonciatifs, figuratifs et narratifs qui viennent en spécifier le registre.This paper compares three biofictions that, in each case, relate one specific day in the life of an author : Patrick and Roman Wald Lasowski’s André Gide. Vendredi 16 octobre 1908 (1992, Alain Buisine’s Proust. Samedi 27 novembre 1909 (1991 and Richard Jorif’s Valéry. Jeudi 10 juin 1927 (1991. In addition to the formal constraint of restricting the text temporally to a twenty-four-hour period, these biofictions all focus on the imaginary reconstruction of the everyday life of the Other, and explore the constituents (temporality, repetition, and insignificance of the paradigm that defines the expression "everyday life", by the use of enunciative, figurative, and narrative forms and devices.

  4. Aircraft Corrosion

    Science.gov (United States)

    1981-08-01

    allowed to dry. The area is then checked for the golden brown color which is produced by the chemical conversion material. If the work area requires...Materials, pp. 258-3074 1968. 41. W. IH. Ailor, "Seven-year exposure at Point leyes , California," "Corrosion in Natural Environments, ASTM STP 558," American... Color Units 3 Turbidity Units 0.7 pH Units 7.6 Temperature OF 76 Sp. Conductivity MMhos 425 B.O.D. (5 days at 206C) 0.2 SjV i;~-- 1201 A .9 8 ~ 8 kl

  5. Pression lexicale et contraintes phonologiques dans la dérivation en -aie du français

    Directory of Open Access Journals (Sweden)

    Michel Roché

    2011-12-01

    Full Text Available La dérivation en -aie (chênaie, roseraie, châtaigneraie... suit normalement le schéma : N de plante + -aie --> N de collectif. Quelques dérivés présents dans les dictionnaires, cependant, s'écartent de cette configuration : cerisaie au lieu de ceriseraie, joncheraie à côté de jonchaie, etc. Ils sont beaucoup plus nombreux, proportionnellement, parmi ceux qu'on peut recueillir sur la Toile. On a mis en évidence deux séries de facteurs, tantôt convergents tantôt antagonistes, qui expliquent ces écarts : (i l'influence de la série dérivationnelle dans laquelle le dérivé est destiné à s'intégrer (un " effet de rime " tend à substituer à la finale phonologiquement " pauvre " -aie la finale plus " riche " -eraie, déjà surreprésentée à cause du grand nombre de noms d'arbres en -ier parmi les bases des dérivations antérieures ; (ii des contraintes de " bonne formation " - contraintes de taille, contraintes dissimilatives - qui conduisent à modifier le thème fourni par la base afin qu'il constitue un radical phonologiquement plus satisfaisant. Le corpus révèle également un grand nombre de dérivés construits sur des thèmes " savants " (bétulaie, lariçaie, suberaie..., bien que le suffixe appartienne lui-même au versant " populaire " de la dérivation ; ce qui conduit à remettre en cause le principe de correspondance univoque entre les cases de l'espace thématique d'un lexème et celles de son paradigme dérivationnel. Ces observations relativisent fortement la notion de " Règle de Construction des Lexèmes " au profit d'un système de contraintes d'ordre lexical ou morphophonologique.

  6. Changes in Meat Quality Characteristics of the Sous-vide Cooked Chicken Breast during Refrigerated Storage.

    Science.gov (United States)

    Hong, Go-Eun; Kim, Ji-Han; Ahn, Su-Jin; Lee, Chi-Ho

    2015-01-01

    This study was performed to investigate the changes in meat quality characteristics of the sous vide cooked chicken breast during refrigerated storage at 4℃ for 14 d between before and after sous-vide cooking. Cooking loss and shear force were significantly increased, whereas expressible drip was significantly decreased along with reduction in the water holding capacity in both of two groups. Redness of meat juice was significantly (psous-vide cooked at the 7 to 10 d. The thiobarbituric acid reactive substances (TBARS) was significantly increased and was higher in the refrigerator stored chicken breast samples after sous-vide cooking. The volatile basic nitrogen (VBN) value was significantly increased in both groups, but the VBN value of the stored raw meat sample before sous-vide cooking was increased at an early storage, while the VBN value of the stored sample after sous-vide cooking was increased gradually in this study. Total viable counts and coliform counts were significantly decreased during storage, and coliforms were not detected after 7 d of storage in both groups. Salmonella spp. was not detected during the whole studied period. The outcome of this research can provide preliminary data that could be used to apply for further study of chicken breast using sous-vide cooking method that could be attractive to consumers.

  7. L’énigme des contraintes grammaticales sur les sujets poyaudins

    Directory of Open Access Journals (Sweden)

    Massot Benjamin

    2016-01-01

    Full Text Available Notre contribution fait état de notre étude en cours des sujets du poyaudin, un patois d’oui. D’une part, en poyaudin, tous les syntagmes nominaux ne sont pas éligibles pour la position syntaxique de sujet : ils doivent pour cela être suffisamment définis/topicaux. Les autres syntagmes nominaux, s’ils doivent exprimer le sujet sémantique de la prédication, doivent être insérés dans des structures syntaxiques où ils peuvent apparaitre en position d’objet : comme élément introduit par y a dans une clivée, ou comme sujet réel d’un verbe à la tournure impersonnelle. D’autre part, les syntagmes nominaux sujets sont (très fréquemment redoublés d’un clitique nominatif. Nous proposons alors un ensemble d’hypothèses : (i Les contraintes qui pèsent sur les sujets dépendent crucialement du fait que les syntagmes candidats à la position syntaxique de sujet sont évalués sur une échelle de définitude/ accessibilité/topicalité. (ii Les clitiques nominatifs portent un trait d’accord de type défini/accessible/topical. Ce trait implique que le redoublement clitique du sujet n’est possible que lorsque le sujet est évalué sur l’échelle en question par une valeur compatible avec le trait du clitique nominatif. Ainsi, certains sujets, trop bas sur cette échelle, ne déclenchent pas l’accord par redoublement clitique. (iii Les syntagmes nominaux trop bas sur l’échelle pour être éligibles en position de sujet trouvent une place adéquate dans les clivées et les tournures impersonnelles parce qu’ils s’y trouvent dans des positions syntaxiques d’objets, qui n’ont pas de restriction dans ce sens.

  8. LA PROTECTION SOCIALE DANS L’UNION EUROPEENNE ENTRE CONSIDERATIONS SOCIALES ET CONTRAINTES ECONOMIQUES

    Directory of Open Access Journals (Sweden)

    Gheorghe PIRVU

    2009-12-01

    Full Text Available Le travail a comme point de départ le problème des systèmes de protection sociale des états membres qui sont mis a dure épreuve dans le dernier décennie, comme conséquence des tendances démographiques mais aussi du niveau augmenté du chômage. Pour cette raison, dans ce travail sont analysées les modalités de financement de la protection sociale dans les états membres de l’Union Européenne et sont relevés les risques induits par les dépenses vastes pour la protection sociale sous la forme du retardement du rythme de la croissance économique ayant des effets opposés sur les revenus et sur le niveau de la protection sociale. Par conséquence, le plus grand problème n’est pas la manière d’amasser la monnaie nécessaire pour la protection sociale de taxes ou contributions, mais la façon de soutenir un niveau adéquat de la croissance économique et d’augmenter le rythme de l’occupation. Dans la seconde partie du travail sont évaluées une série de modalités par lesquelles on peut assurer le remboursement du social dans les conditions des restrictions politiques et économiques, étant possible d’identifier deux aspects qui sont mis en discussion : la sélectivité croissante des prestations et la redéfinition de la structure des prélèvements.

  9. Al-Ḥudayyda sous occupation ottomane (1849-1918

    Directory of Open Access Journals (Sweden)

    Patrice Chevalier

    2011-12-01

    Full Text Available Petit port de pêche situé sur les côtes de la mer Rouge, al-Ḥudayyda change progressivement de statut et de dimensions avec l’arrivée de l’armée ottomane en 1839. Al-Ḥudayyda se voit alors choisi comme l’un des points stratégiques (militaire et politique du dispositif colonial ottoman.Grâce aux différentes infrastructures mises en place par l’administration ottomane, mais aussi grâce à l’ouverture du canal de Suez en 1869, le village attire peu à peu une population multi-ethnique et cosmopolite venue y commercer ou simplement y trouver refuge, dans un contexte politique régional passablement agité. D’une centaine de Yéménites à l’origine, il compte 42 000 âmes à la veille de la première guerre mondiale.La cohabitation sous administration ottomane va-t-elle générer ou non des échanges ou emprunts entre les différentes communautés ? Les Ottomans vont-ils réussir à transcender les multiples appartenances identitaires au profit d’une appartenance citoyenne à l’empire, comme le prévoit leur ambitieux programme de réformes ? La ville d’al- Ḥudayyda sera-t-elle dotée d’une identité spécifique suffisamment forte pour que les individus appartenant aux différentes communautés présentes s’identifient à la ville ? Voilà quelques-unes des questions auxquelles cet article tente de répondre.

  10. Introduction to the reliability study of IGBT switching cells under strong constraints; Introduction a l'etude de la fiabilite des cellules de commutation a IGBT sous fortes contraintes

    Energy Technology Data Exchange (ETDEWEB)

    Vallon, J.

    2003-12-15

    The reliability approach in power electronics is a complex problem including the coupling of current / voltage surges, physical and technological imperfections, from the die to the power circuit. First of all, we define a methodology based on the monitoring of a great number of components, during a long time campaign. Components are 600 V-50 A-20 kHz IGBT-diodes modules working in PWM inverter cells owing to an original opposition method. An exhaustive study of cell-switching failure modes allowed us to design a suitable and efficient protection. Afterwards, a complete reliability test bench was carried out with electrical and thermal monitoring. A preliminary screening protocol was also applied. The first results are presented in this thesis. (author)

  11. Study and simulation of a multi-lithology stratigraphic model under maximum erosion rate constraint; Etude et simulation d'un modele statigraphique multi-lithologique sous contrainte de taux d'erosion maximal

    Energy Technology Data Exchange (ETDEWEB)

    Gervais, V.

    2004-11-01

    The subject of this report is the study and simulation of a model describing the infill of sedimentary basins on large scales in time and space. It simulates the evolution through time of the sediment layer in terms of geometry and rock properties. A parabolic equation is coupled to an hyperbolic equation by an input boundary condition at the top of the basin. The model also considers a unilaterality constraint on the erosion rate. In the first part of the report, the mathematical model is described and particular solutions are defined. The second part deals with the definition of numerical schemes and the simulation of the model. In the first chap-ter, finite volume numerical schemes are defined and studied. The Newton algorithm adapted to the unilateral constraint used to solve the schemes is given, followed by numerical results in terms of performance and accuracy. In the second chapter, a preconditioning strategy to solve the linear system by an iterative solver at each Newton iteration is defined, and numerical results are given. In the last part, a simplified model is considered in which a variable is decoupled from the other unknowns and satisfies a parabolic equation. A weak formulation is defined for the remaining coupled equations, for which the existence of a unique solution is obtained. The proof uses the convergence of a numerical scheme. (author)

  12. Environment and mobility 2050: scenarios for a 75% reduction in CO{sub 2} emissions; Environnement et mobilite 2050: des scenarios sous contrainte du facteur 4 (-75% de CO{sub 2} en 2050)

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Ruiz, H.G.

    2009-10-15

    In France an objective of dividing greenhouse gas emissions by four, from the 1990 level, by 2050 has been set. Are these ambitions out of our reach? What will the price to pay for this objective be? We have built a long-term back-casting transport demand model (TILT, Transport Issues in the Long Term) . This model is centered on defined behavior types - in which the speed-GDP elasticity plays a key role - in order to determine demand estimations. This model lets us understand past tendencies - the coupling between growth and personal and freight mobility and adapt behavioral hypothesis - linked to the evolution of public policies - in order to show how a 75% reduction objective can be attained. The main results are an estimation of CO{sub 2} emissions for the transport sector taking into account technical progress and demand. These results are presented as three scenario families named: Pegasus, Chronos and Hestia. Each family corresponds to a growing degree of constraint on mobility. It is possible to divide greenhouse gas emissions in the transport sector by four. Technical progress is able to lead to more than half of these reductions. The interest of these scenarios is to show that there exist different paths - through organizational change - to getting the other half of the reductions. (author)

  13. Modelling of Corrosion Cracks

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed.......Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed....

  14. La progression de l’absentéisme : nouveaux comportements des salariés ou nouvelles contraintes organisationnelles ?

    OpenAIRE

    Bouville, Gregor

    2010-01-01

    A partir des données de la CNAM, nous constatons une progression de l’absentéisme en France, mesuré par le nombre d’indemnités journalières maladie, depuis la fin des années 1990. Faut-il y voir le signe d’un développement des comportements de retrait des salariés français ou bien l’interpréter comme étant la conséquence de l’émergence de nouvelles contraintes organisationnelles ? Pour répondre à cette question de recherche, nous réaliserons une analyse quantitative à partir des données de l’...

  15. Evaluation mécanique d'une dalle précontrainte par mesure de la courbure

    OpenAIRE

    COLLIN, B; TONNOIR, B

    2001-01-01

    L'évaluation mécanique d'un ouvrage d'art a été réalisée en utilisant conjointement, et pour la première fois sur une dalle isostatique en béton précontraint, deux prototypes de courburemètre du réseau des LPC. Cette évaluation s'est appuyée sur des mesures, faites en plusieurs sections, des variations de courbure causées par la circulation sur l'ouvrage d'un convoi de caractéristiques connues. D'un point de vue pratique, la facilité d'utilisation des courburemètres, simplement posés sur la c...

  16. Management of Reinforcement Corrosion

    DEFF Research Database (Denmark)

    Küter, André; Geiker, Mette Rica; Møller, Per

    Reinforcement corrosion is the most important cause for deterioration of reinforced concrete structures, both with regard to costs and consequences. Thermodynamically consistent descriptions of corrosion mechanisms are expected to allow the development of innovative concepts for the management...... of reinforcement corrosion....

  17. Corrosion inhibitors; Los inhibidores de corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Godinez, L. A.; Meas, Y.; Ortega-Borges, R.; Corona, A.

    2003-07-01

    In this paper, we briefly describe the characteristics, cost and electrochemical nature of the corrosion phenomena as well as some of the technologies that are currently employed to minimize its effect. The main subject of the paper however, deals with the description, classification and mechanism of protection of the so-called corrosion inhibitors. Examples of the use of these substances in different aggressive environments are also presented as means to show that these compounds, or their combination, can in fact be used as excellent and relatively cheap technologies to control the corrosion of some metals. In the last part of the paper, the most commonly used techniques to evaluate the efficiency and performance of corrosion inhibitors are presented as well as some criteria to make a careful and proper selection of a corrosion inhibitor technology in a given situation. (Author) 151 refs.

  18. Effect of Sous Vide Cooking Method on Nutritional Values of Vegetables

    Directory of Open Access Journals (Sweden)

    Serap Coşansu

    2016-11-01

    Full Text Available Sous vide is a cooking method in which food is heat processed after vacuum packaging in heat stable pouches. Meat, chicken, fish and vegetables can be cooked by this method; even meals containing these ingredients can be preserved by heat processing after precooking and vacuum packaging steps. Meanwhile sous vide cooking is a preservation method that the product is cooled rapidly after heat processing and can be stored for long periods. By this method, food can be cooked in vacuum packed without losing its flavour, taste and nutritional value. In this review, the effects of sous vide cooking on the major nutrients of vegetables such as antioxidant compounds and vitamins will be mentioned.

  19. Determination of shelf life of sous vide salmon (Salmo salard) based on sensory attributes.

    Science.gov (United States)

    Díaz, Pedro; Nieto, Gema; Bañón, Sancho; Garrido, María Dolores

    2009-10-01

    Sous vide technology permits precooked dishes of high sensory and nutritional quality to be obtained with a longer shelf life than is possible using other cooking-cooling methods. Salmon portions (200 g; 0.5, w:w; greased with olive oil) were par-roasted (300 degrees C/3 min), cooked using sous vide technology (80 degrees C/43 min), and maintained in anaerobic conditions at 2 degrees C for 0, 4, 8, 12, 15, 18, 22, and 25 d. At each control day, Enterobacteriaceae counts were made and the attributes of sensory spoilage were determined (3 visual, 2 odor, 2 flavor, and 3 texture attributes) by a panel of trained judges. A loss of smell, taste, color, and juiciness was detected during storage, along with the appearance of off-odors and off-flavors. The shelf life of the sous vide salmon based on sensory analysis was established at 18 d.

  20. Sous vide- ja matalalämpökypsennysmenetelmien tulevaisuus Suomessa

    OpenAIRE

    Lehtimäki, Saija; Nasr, Suzanna

    2013-01-01

    Tutkimuksen aihe valikoitui tutkijoiden mielenkiinnosta sous vide- ja matalalämpökypsennysmenetelmiä kohtaan. Opinnäytetyön aiheena ovat tulevaisuuden ruoanvalmistusmenetelmät. Tutkimuksen aihe rajattiin sous vide- ja matalalämpökypsennysmenetelmien käyttöön Suomessa. Tutkimuksen avulla pyritään selvittämään kyseisten menetelmien tulevaisuutta Suomessa lähinnä elintarviketeollisuuden näkökulmasta. Tarkoituksena on selvittää, miten menetelmiä hyödynnetään tällä hetkellä, ja miten menetelmie...

  1. Development of Pangasius steaks by improved sous-vide technology and its process optimization.

    Science.gov (United States)

    Kumari, Namita; Singh, Chongtham Baru; Kumar, Raushan; Martin Xavier, K A; Lekshmi, Manjusha; Venkateshwarlu, Gudipati; Balange, Amjad K

    2016-11-01

    The present study embarked on the objective of optimizing improved sous-vide processing condition for development of ready-to-cook Pangasius steaks with extended shelf-life using response surface methodology. For the development of improved sous-vide cooked product, Pangasius steaks were treated with additional hurdles in various combinations for optimization. Based on the study, suitable combination of chitosan and spices was selected which enhanced antimicrobial and oxidative stability of the product. The Box-Behnken experimental design with 15 trials per model was adopted for designing the experiment to know the effect of independent variables, namely chitosan concentration (X1), cooking time (X2) and cooking temperature (X3) on dependent variable i.e. TBARS value (Y1). From RSM generated model, the optimum condition for sous-vide processing of Pangasius steaks were 1.08% chitosan concentration, 70.93 °C of cooking temperature and 16.48 min for cooking time and predicted minimum value of multiple response optimal condition was Y = 0.855 mg MDA/Kg of fish. The high correlation coefficient (R(2) = 0.975) between the model and the experimental data showed that the model was able to efficiently predict processing condition for development of sous-vide processed Pangasius steaks. This research may help the processing industries and Pangasius fish farmer as it provides an alternative low cost technology for the proper utilization of Pangasius.

  2. Monitoring Microbially Influenced Corrosion

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    Abstract Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria (SRB). The applicability and reliability of a number of corrosion monitoring techniques for monitoring MIC has been evaluated in experiments...... and diffusional effects and unreliable corrosion rates, when biofilm and ferrous sulphide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 by electrochemical techniques. Weight loss coupons and ER are recommended as necessary basic monitoring techniques....... EIS might be used for detection of MIC as the appearance of very large capacitances can be attributed to the combined ferrous sulphide and biofilm formation. Capacitance correlates directly with sulphide concentration in sterile sulphide media. Keywords: Corrosion monitoring, carbon steel, MIC, SRB...

  3. Electrochemical corrosion studies

    Science.gov (United States)

    Knockemus, W. W.

    1986-01-01

    The objective was to gain familiarity with the Model 350 Corrosion Measurement Console, to determine if metal protection by grease coatings can be measured by the polarization-resistance method, and to compare corrosion rates of 4130 steel coated with various greases. Results show that grease protection of steel may be determined electrochemically. Studies were also conducted to determine the effectiveness of certain corrosion inhibitors on aluminum and steel.

  4. Erosion-corrosion; Erosionkorrosion

    Energy Technology Data Exchange (ETDEWEB)

    Aghili, B

    1999-05-01

    A literature study on erosion-corrosion of pipings in the nuclear industry was performed. Occurred incidents are reviewed, and the mechanism driving the erosion-corrosion is described. Factors that influence the effect in negative or positive direction are treated, as well as programs for control and inspection. Finally, examples of failures from databases on erosion-corrosion are given in an attachment 32 refs, 16 figs, tabs

  5. Le jeu des contraintes dans la sélection du thème présuffixal

    Directory of Open Access Journals (Sweden)

    Roché Michel

    2014-07-01

    Full Text Available Dans le cadre d’une morphologie lexématique, les notions de thème et d’« espace thématique » ont fait leurs preuves pour rendre compte de l’allomorphie radicale des lexèmes en ce qui concerne la flexion. Leurs premières applications à la dérivation ont été prometteuses, mais un examen plus systématique soulève de nombreuses difficultés. L’articulation entre flexion et dérivation, forte pour les verbes, est faible pour les adjectifs et nulle pour les noms. Dans ces deux catégories, des travaux récents ont fait apparaître un important polymorphisme (plusieurs formes pour un même thème. La distinction entre un thème présuffixal « populaire » et un thème présuffixal « savant » reste pertinente, mais la sélection de l’un ou de l’autre n’est nullement automatique : elle entre dans un jeu de contraintes, comme, à l’intérieur de chaque thème, le choix des formes qui peuvent s’y trouver en concurrence. Ces contraintes sont principalement d’ordre lexical et visent à la cohérence de la famille dérivationnelle à laquelle appartiennent le lexème et son dérivé ; à la cohérence de la série dérivationnelle dans laquelle le dérivé doit s’intégrer ; à la cohérence entre le thème sélectionné et le registre – populaire ou savant – auquel appartient le mode de formation. Elles visent également un maximum de sauvegarde, dans le dérivé, des dimensions phonique et graphique de la forme libre. Elles visent enfin une « bonne formation » phonologique du dérivé : syllabation, dissimilation, optimum prosodique.

  6. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  7. Monitoring Microbially Influenced Corrosion

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    and diffusional effects and unreliable corrosion rates, when biofilm and ferrous sulphide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 by electrochemical techniques. Weight loss coupons and ER are recommended as necessary basic monitoring techniques....... EIS might be used for detection of MIC as the appearance of very large capacitances can be attributed to the combined ferrous sulphide and biofilm formation. Capacitance correlates directly with sulphide concentration in sterile sulphide media. Keywords: Corrosion monitoring, carbon steel, MIC, SRB...

  8. Corrosion in the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Brondel, D. (Sedco Forex, Montrouge (France)); Edwards, R. (Schlumberger Well Services, Columbus, OH (United States)); Hayman, A. (Etudes et Productions Schlumberger, Clamart (France)); Hill, D. (Schlumberger Dowell, Tulsa, OK (United States)); Mehta, S. (Schlumberger Dowell, St. Austell (United Kingdom)); Semerad, T. (Mobil Oil Indonesia, Inc., Sumatra (Indonesia))

    1994-04-01

    Corrosion costs the oil industry billions of dollars a year, a fact that makes the role of the corrosion engineer an increasingly important one. Attention is paid to how corrosion affects every aspect of exploration and production, from offshore rigs to casing. Also the role of corrosion agents such as drilling and production fluids is reviewed. Methods of control and techniques to monitor corrosion are discussed, along with an explanation of the chemical causes of corrosion. 21 figs., 32 refs.

  9. Mobilités contraintes, parcours professionnels, vie privée: Quels enjeux pour les cadres bancaires?

    Directory of Open Access Journals (Sweden)

    Isabel Bertaux-Wiame

    2009-03-01

    Full Text Available Cet article porte sur les cadres du secteur bancaire, groupe socio-professionnel plutôt privilégié. Pourtant, une analyse des parcours de ces cadres, hommes et femmes, que restituent des entretiens approfondis, met en évidence des tensions entre vie professionnelle et vie conjugale: ils sont contraints d’accepter des mobilités géographiques pour eux-mêmes et leur famille contre l’assurance d’une carrière. Le modèle classique de la division sexuée du travail au sein des couples place le salarié dans une double obligation de réussite face à son employeur, face à sa famille qui consent à le ‘suivre’ dans son nomadisme professionnel. Les contradictions observées, facteurs de déstabilisation, peuvent devenir des facteurs de résistance lorsque ces cadres refusent le coût conjugal d’une mobilité géographique et que les conjointes s’opposent aux impératifs managériaux.

  10. Carbon Dioxide Corrosion:

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup

    2008-01-01

    CO2 corrosion is a general problem in the industry and it is expensive. The focus of this study is an oil gas production related problem. CO2 corrosion is observed in offshore natural gas transportation pipelines. A general overview of the problem is presented in chapter 1. The chemical system co...

  11. Corrosion evaluation technology

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Uh Chul; Han, Jeong Ho; Nho, Kye Ho; Lee, Eun Hee; Kim, Hong Pyo; Hwang, Seong Sik; Lee, Deok Hyun; Hur, Do Haeng; Kim, Kyung Mo

    1997-09-01

    A multifrequency ACPD system was assembled which can measure very small crack. Stress corrosion cracking test system with SSRT operating high temperature was installed. Stress corrosion cracking test of newly developed alloy 600 and existing alloy 600 was carried out in steam atmosphere of 400 deg C. No crack was observed in both materials within a test period of 2,000 hrs. Corrosion fatigue test system operating at high temperature was installed in which fatigue crack was measured by CDPD. Lead enhanced the SCC of the Alloy 600 in high temperature water, had a tendency to modify a cracking morphology from intergranular to transgranular. Pit initiation preferentially occurred at Ti-rich carbide. Resistance to pit initiation decreased with increasing temperature up to 300 deg C. Test loop for erosion corrosion was designed and fabricated. Thin layer activation technique was very effective in measuring erosion corrosion. Erosion corrosion of a part of secondary side pipe was evaluated by the Check Family Codes of EPRI. Calculated values of pipe thickness by Check Family Codes coincided with the pipe thickness measured by UT with an error of {+-} 20%. Literature review on turbine failure showed that failure usually occurred in low pressure turbine rotor disc and causes of failure are stress corrosion cracking and corrosion fatigue. (author). 12 refs., 20 tabs., 77 figs.

  12. Avionics Corrosion Control Study

    Science.gov (United States)

    1974-01-01

    found at seacoast (harsn) environnents is the most destructive. Differences in electrolte concentration and oxygen concentration promote corrosion...against corrosion by acting as moisture and gas barriers. CMCVIT B0.4ID *COATINGS Polyurethane’s, cprxies, silicones, and polystyrenes are the most

  13. Monitoring corrosion rates and localised corrosion in low conductivity water

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2006-01-01

    Monitoring of low corrosion rates and localised corrosion in a media with low conductivity is a challenge. In municipal district heating, quality control may be improved by implementing on-line corrosion monitoring if a suitable technique can be identified to measure both uniform and localised...... corrosion. Electrochemical techniques (LPR, EIS, crevice corrosion current) as well as direct measurement techniques (high-sensitive electrical resistance, weight loss) have been applied in operating plants. Changes in the corrosion processes are best monitored in non-aggressive, low conductivity media...... with sensitive electrical resistance technique and crevice corrosion current measurements....

  14. Croissance des fonctions sous-harmoniques et des fonctions entières dans $C^N$

    CERN Document Server

    Supper, R; Ramis, J P

    2005-01-01

    Ce mémoire d'habilitation présente une synthèse de mes travaux de ces dernières années et expose quelques projets de recherche. Il aborde différentes questions relatives à la croissance des fonctions sous-harmoniques (dans la boule unité ou dans l'espace tout entier) et des fonctions entières de type exponentiel, par exemple: caractérisation des fonctions sous-harmoniques avec une croissance de type Bloch, étude de la mesure de Riesz d'une fonction sous-harmonique, minoration des fonctions sous-harmoniques d'ordre au plus un, détermination des fonctions entières de plusieurs variables complexes dont la partie réelle s'annule en certains poin

  15. Kyste hydatique sous cutané isolé: à propos d’un cas et revue de la literature

    Science.gov (United States)

    Lemrhari, Bahija; Baha, Hasna; Azzouzi, Soufia; Chiheb, Soumyia

    2016-01-01

    La localisation sous cutanée, primitive et isolée, du kyste hydatique est exceptionnelle, même dans les pays où la maladie hydatique est endémique. Nous rapportons le cas d’une jeune patiente présentant un kyste hydatique sous cutané sans atteintes viscérales associées. PMID:27800067

  16. Mitigation of Corrosion on Magnesium Alloy by Predesigned Surface Corrosion

    OpenAIRE

    Xuming Zhang; Guosong Wu; Xiang Peng; Limin Li; Hongqing Feng; Biao Gao; Kaifu Huo; Chu, Paul K.

    2015-01-01

    Rapid corrosion of magnesium alloys is undesirable in structural and biomedical applications and a general way to control corrosion is to form a surface barrier layer isolating the bulk materials from the external environment. Herein, based on the insights gained from the anticorrosion behavior of corrosion products, a special way to mitigate aqueous corrosion is described. The concept is based on pre-corrosion by a hydrothermal treatment of Al-enriched Mg alloys in water. A uniform surface c...

  17. Corrosion Failures in Marine Environment

    Directory of Open Access Journals (Sweden)

    R. Krishnan

    1985-04-01

    Full Text Available This paper gives a brief description of typical marine environments and the most common form of corrosion of materials used in this environment. Some typical case histories of failures pertaining to pitting, bimetallic corrosion, dealloying, cavitation and stress corrosion cracking are illustrated as typical examples of corrosion failures.

  18. Corrosion Inhibitors for Reinforced Concrete

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Steel corrosion in reinforced concrete structures has been a major problem across the U.S. Steel-reinforced concrete structures are continually subject to attack by corrosion brought on by naturally occurring environmental conditions. FerroGard, a corrosion inhibitor, developed by Sika Corporation, penetrates hardened concrete to dramatically reduce corrosion by 65% and extend the structure's service life.

  19. Automated Methods Of Corrosion Measurements

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers; Andersen, Jens Enevold Thaulov; Reeve, John Ch

    1997-01-01

    The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell.......The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell....

  20. The Corrosion and Preservation of Iron Antiques.

    Science.gov (United States)

    Walker, Robert

    1982-01-01

    Discusses general corrosion reactions (iron to rust), including corrosion of iron, sulfur dioxide, chlorides, immersed corrosion, and underground corrosion. Also discusses corrosion inhibition, including corrosion inhibitors (anodic, cathodic, mixed, organic); safe/dangerous inhibitors; and corrosion/inhibition in concrete/marble, showcases/boxes,…

  1. Une localisation exceptionnelle de la tuberculose vertébrale Mal de Pott sous-occipital

    Science.gov (United States)

    Yahyaoui, Sana; Majdoub, Senda; Zaghouani, Houneida; Fradj, Hosni Ben; Bakir, Dejla; Bouajina, Elyes; Kraiem, Chakib

    2013-01-01

    Le mal de Pott est la forme la plus commune de la tuberculose osseuse touchant essentiellement le rachis dorso-lombaire. La localisation sous-occipitale reste exceptionnelle. Le diagnostic de cette entité est le plus souvent tardif ce qui expose à des complications graves. Les radiographies standard ne sont parlantes qu’à un stade tardif de la maladie, d'où l'intérêt de l'imagerie moderne notamment la tomodensitométrie (TDM) et l'imagerie par résonance magnétique (IRM) qui permettent un diagnostic précoce. Nous rapportons un nouveau cas de tuberculose sous-occipitale. Le diagnostic était posé sur l'imagerie en coupe et confirmé histologiquement à la biopsie transorale. Sont rappelés les aspects en imagerie de cette localisation particulière du mal de Pott. PMID:23819005

  2. Safety aspects of "sous vide" products and prevention of microbial risks.

    Science.gov (United States)

    Martens, T

    1995-03-01

    The diversity and quantities of vacuum packed and vacuum cooked prepared meals and menu components are rapidly growing on the European market. Because of the minimal heat processing, high water activity, absence of preservatives, and the use of many different often exotic ingredients, these products have a high risk potential. For this reason, Anglo-Saxon governments and industries are very sceptical about the safety of "sous vide" products. Industrial practice, as well as parallel tests and recent studies on inoculated packs have shown that, in many cases, it is more a potential than a real risk. Quality is the primary concern for "sous vide" products, and safety must be guaranteed by the application of the Hazard Analysis Critical Control Point (HACCP) concept, along with an adequate combination of different inhibitory factors (temperature of heating and cooling, pH, incorporation of starter cultures, bacteriocins and some particular enzymes).

  3. [The use of "sous vide" technology in the packaging of chilled and ready to serve food].

    Science.gov (United States)

    Zalewski, S

    1999-01-01

    As chilled precooked dishes show limited to 3-5 days shelf life several additional factors have to be applied to extend it up to 21 or even 42 days as is sometimes allowed for sous vide technology products. Those factors comprise high hygienic standards for raw materials and premises as well as technological steps and parameters that efficiently destroy microbial contamination, and do not allow for recontamination or bacterial growth. Such steps include precooking which also means pasteurisation in high vacuum or anaerobic atmosphere in sealed pouches, blast chilling, low temperature storage parameters as well as high temperature of reheating process and quick serving procedures. Paper specifies parameters for each technological steps and presents microbiological requirements for final products. Sous vide technology allows for good quality and high nutritional value in soups, meats in sauces and stewed vegetables. It is used for individual consumer in chilled "ready to eat" line dishes in supermarkets and supplies such dishes for catering units.

  4. Advantages of sous-vide cooked red cabbage: structural, nutritional and sensory aspects

    OpenAIRE

    Iborra Bernad, María del Consuelo; Tárrega, Amparo; García Segovia, Purificación; Martínez Monzó, Javier

    2014-01-01

    The comparison between equivalent cooking treatments should be applied in a systematic way. This study proposes a methodical way to provide cooked samples with similar firmness using two cooking treatments. In addition, the structural, nutritional and sensory properties of red cabbage cooked with sous-vide treatment in comparison with traditional cooking (boiling water) was evaluated. Changes in texture, color and anthocyanin content were measured in samples cooked with traditional cooking...

  5. Shelf Life Extension of Maple pea (Pisum sativum var. arvense L. Spread Using Sous Vide

    Directory of Open Access Journals (Sweden)

    Ķirse Asnate

    2016-12-01

    Full Text Available The aim of this study was to determine the effect of sous vide packaging on the shelf life of maple pea (Pisum sativum var. arvense L. spread. Pea spreads were made of ground re-hydrated cooked maple peas ‘Bruno’ (Pisum sativum var. arvense L., to which salt, citric acid, oil, and spices were added. Pea spread was stored in polyamide/polyethylene (PA/PE film pouches, packaged in vacuum and hermetically sealed. Pea spread pouches were heat treated in a water bath, then rapidly cooled in ice-water and stored at 4.0 ± 0.5 °C. Sous vide was applied in three different heat regimens +(65.0; 80.0 and 100.0 ± 0.5 °C with cooking times 5, 10, 15, 20, 25, and 30 min at a constant temperature. Total plate count was determined according to ISO 4833-1:2014 on Plate Count Agar and Enterobacteriaceae determination was performed in accordance with ISO 21528-2:2004 on Violet Red Bile Glucose Agar. Total plate count in pea spread without thermal treatment was 3.41 log10 CFU g−1, in all sous vide packaged pea spread samples microbial contamination was significantly lower (p < 0.05. Enterobacteriaceae were not detected in any samples. It is possible to extend the shelf life of sous vide maple pea spread up to 14 weeks when stored at 4.0 ± 0.5 °C.

  6. Nouveaux loisirs, nouveaux espaces: les fonds sous-marins du littoral languedocien

    Directory of Open Access Journals (Sweden)

    Frédéric Galinier

    2000-06-01

    Full Text Available L’exploration des fonds sous-marins fascine un nombre croissant de jeunes citadins. Le littoral de l’Hérault, même bas et peu rocheux, ne fait pas exception à la règle et l’activité subaquatique s’y développe. Les effets n’en sont pas négligeables pour les revenus de certaines communes littorales, ainsi que sur l’environnement.

  7. Corrosion control in mining technology

    Energy Technology Data Exchange (ETDEWEB)

    Telekesi, J.

    1985-01-01

    An overview of corrosion effects in mining technology and the importance of protection is presented. The most common corrosion processes and effects are summarized and the system and criteria of their avoidance are discussed in detail. Preventive measures are recommended to decrease possible corrosion effects including the selection of corrosion-resistive constructions, to use protective coatings and inhibition techniques and some other protection possibilities where applicable. The organization aspects and the economic impact of corrosion control in mining are discussed.

  8. Corrosion-resistant uranium

    Science.gov (United States)

    Hovis, V.M. Jr.; Pullen, W.C.; Kollie, T.G.; Bell, R.T.

    1981-10-21

    The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

  9. Application of nisin and pediocin against resistance and germination of Bacillus spores in sous vide products.

    Science.gov (United States)

    Cabo, M L; Torres, B; Herrera, J J R; Bernárdez, M; Pastoriza, L

    2009-03-01

    Sous vide and other mild preservation techniques are increasingly demanded by consumers. However, spores often will survive in minimally processed foods, causing both spoilage and safety problems. The main objective of the present work was to solve an industrial spoilage problem associated with two sous vide products: mushrooms and shellfish salad. Bacillus subtilis and Bacillus licheniformis predominated as the most heat-resistant organisms isolated from mushrooms and shellfish salad, respectively. The combined effects of nisin and pediocin against resistance and germination of both Bacillus species were described by empirical equations. Whereas nisin was more effective for decreasing thermal resistance of B. subtilis spores, pediocin was more effective against B. licheniformis. However, a significant positive interaction between both biopeptides for decreasing the proportion of vegetative cells resulting from thermoresistant spores was demonstrated in later experiments, thus indicating the increased efficacy of applying high concentrations of both bacteriocins. This efficacy was further demonstrated in additional challenge studies carried out at 15 degrees C in the two sous vide products: mushrooms and shellfish salad. Whereas no vegetative cells were detected after 90 days in the presence of bacteriocins, almost 100% of the population in nontreated samples of mushrooms and shellfish salad was in the vegetative state after 17 and 43 days of storage at 15 degrees C, respectively.

  10. Volatile compound profile of sous-vide cooked lamb loins at different temperature-time combinations.

    Science.gov (United States)

    Roldán, Mar; Ruiz, Jorge; Del Pulgar, José Sánchez; Pérez-Palacios, Trinidad; Antequera, Teresa

    2015-02-01

    Lamb loins were subjected to sous-vide cooking at different combinations of temperature (60 and 80°C) and time (6 and 24h) to assess the effect on the volatile compound profile. Major chemical families in cooked samples were aliphatic hydrocarbons and aldehydes. The volatile compound profile in sous-vide cooked lamb loin was affected by the cooking temperature and time. Volatile compounds arising from lipid oxidation presented a high abundance in samples cooked at low or moderate cooking conditions (60°C for 6 and 24h, 80°C for 6h), while a more intense time and temperature combination (80°C for 24h) resulted on a higher concentration of volatile compounds arising from Strecker degradations of amino acids, as 2-methylpropanal and 3-methylbutanal. Therefore, sous-vide cooking at moderately high temperatures for long times would result in the formation of a stronger meaty flavor and roast notes in lamb meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Identification de quelques contraintes à la production de manioc Manihot utilissima, de patate douce Ipomoea batatas et de pomme de terre Solanum tuberosum à l'Est du Zaïre

    Directory of Open Access Journals (Sweden)

    Ngoy Kadiebwe, N.

    1994-01-01

    Full Text Available Identification Of Some Constraints To The Production Of Tubers : Manihot utilissima, Ipomoea batatas and Solanum tuberosum In Eastern Zaire. An agricultural enquiry held to tubercular plants producers in radius of about 20 km to the Research Center has allowed to reveal some contraints related to the production of these speculations in order to pose certain investigations. The main contraints among them are utilization of too long cycle varieties with insufficient quality and quantity, ignorance of the selection production and conservation techniques without forgetting the difficultes of evacuating the production.

  12. Intégration de contraintes temps-réel au sein d'un processus de développement incrémental basé sur la preuve (Livrable 2)

    OpenAIRE

    Cansell, Dominique; Méry, Dominique; Rehm, Joris

    2008-01-01

    The report investigates the integration of time constraintes in the refinement-based development in Event B. Specific proof-based patterns are proposed for developing models including time-oriented aspects.; Ce livrable est un rapport sur l'intégration de contraintes temporelles dans les modèles Event-B. Nous entendons par contraintes temporelles, les propriétés que possède, ou que l'on veut imposer à, un système, par rapport à son déroulement dans le temps. On parle aussi de proprie...

  13. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  14. Physico-Chemical and Structural Characteristics of Vegetables Cooked Under Sous-Vide, Cook-Vide, and Conventional Boiling.

    Science.gov (United States)

    Iborra-Bernad, C; García-Segovia, P; Martínez-Monzó, J

    2015-08-01

    In this paper, physico-chemical and structural properties of cut and cooked purple-flesh potato, green bean pods, and carrots have been studied. Three different cooking methods have been applied: traditional cooking (boiling water at 100 °C), cook-vide (at 80 and 90 °C) and sous-vide (at 80 °C and 90 °C). Similar firmness was obtained in potato applying the same cooking time using traditional cooking (100 °C), and cook-vide and sous-vide at 90 °C, while in green beans and carrots the application of the sous-vide (90 °C) required longer cooking times than cook-vide (90 °C) and traditional cooking (100 °C). Losses in anthocyanins (for purple-flesh potatoes) and ascorbic acid (for green beans) were higher applying traditional cooking. β-Carotene extraction increased in carrots with traditional cooking and cook-vide (P vide. Traditional cooking was the most aggressive treatment in green beans because the secondary walls were reduced compared with sous-vide and cook-vide. Sous-vide preserved organelles in the carrot cells, which could explain the lower extraction of β-carotene compared with cook-vide and traditional cooking. Sous-vide cooking of purple-flesh potato is recommended to maintain its high anthocyanin content. Traditional boiling could be recommended for carrots because increase β-carotenes availability. For green beans, cook-vide, and sous-vide provided products with higher ascorbic acid content. © 2015 Institute of Food Technologists®

  15. Modelling reinforcement corrosion in concrete

    DEFF Research Database (Denmark)

    Michel, Alexander; Geiker, Mette Rica; Stang, Henrik

    2012-01-01

    A physio-chemical model for the simulation of reinforcement corrosion in concrete struc-tures was developed. The model allows for simulation of initiation and subsequent propaga-tion of reinforcement corrosion. Corrosion is assumed to be initiated once a defined critical chloride threshold...... is reached causing the formation of anodic and cathodic regions along the reinforcement. Critical chloride thresholds, randomly distributed along the reinforcement sur-face, link the initiation and propagation phase of reinforcement corrosion. To demonstrate the potential use of the developed model......, a numerical example is pre-sented, that illustrates the formation of corrosion cells as well as propagation of corrosion in a reinforced concrete structure....

  16. Corrosion and Corrosion Control in Light Water Reactors

    Science.gov (United States)

    Gordon, Barry M.

    2013-08-01

    Serious corrosion problems have plagued the light water reactor (LWR) industry for decades. The complex corrosion mechanisms involved and the development of practical engineering solutions for their mitigation will be discussed in this article. After a brief overview of the basic designs of the boiling water reactor (BWR) and pressurized water reactor (PWR), emphasis will be placed on the general corrosion of LWR containments, flow-accelerated corrosion of carbon steel components, intergranular stress corrosion cracking (IGSCC) in BWRs, primary water stress corrosion cracking (PWSCC) in PWRs, and irradiation-assisted stress corrosion cracking (IASCC) in both systems. Finally, the corrosion future of both plants will be discussed as plants extend their period of operation for an additional 20 to 40 years.

  17. Conventional food preparation, cook and chill and sous-vide as optional methods for institutional kitchens. Perinteinen ruoanvalmistus, cook and chill ja sous-vide toimintavaihtoehdot suurkeittioessae

    Energy Technology Data Exchange (ETDEWEB)

    Paeivaerinta, T., Reisbacka, A., Salminen, M.

    1993-01-01

    The purpose of the study was to clarify the situation concerning the energy consumption, economics and the appropriateness of the three options when applied in institutional households. The options included in the study were conventional (preparation-cooking-serving), cook and chill and sous-vide (vacuum cooking-chilling). A further aim was to compare industrially produced products to self-made products. Each option was studied in connection with several devices embodying latest technology. The overall price for a portion was found to be cheapest when using the conventional preparation method. The cook and chill method was only slightly more expensive. The result of this study also support the understanding that when appropriately planned, cook and chill and sous-vide food preparation options make possible the rationalisation of kitchen work. The appropriateness of different food preparation methods depends on the versatility of the functions and programmes built into cooking devices. A combination oven is appropriate and conserves energy when cooking or heating up large quantities. Significant waste of water (126-146 1/h) is possible because of the structural solutions and modes of use of such an oven. A microwave oven saves energy when used to heat up ready-made portions. The amount of energy consumed by an air-cooled chilling cabinet in the cooling of food makes it more economical to use than a water-cooled model. The amount of electricity consumed by a refrigerator or an equivalent cold storage is 5-14 times less than that consumed by chilling devices

  18. Comparison between boiling and vacuum cooking (sous-vide) in the bioaccessibility of minerals in bovine liver samples.

    Science.gov (United States)

    da Silva, Francisco L F; de Lima, João P S; Melo, Luciana S; da Silva, Yarina S M; Gouveia, Sandro T; Lopes, Gisele S; Matos, Wladiana O

    2017-10-01

    Only some of ingested nutrients are available for absorption by the organism. The foods generally are submitted to some heat processing that may interfere in the bioaccessibility of nutrients. There are no studies of the influence of cooking under vacuum (sous vide) on the bioaccessibility of minerals. This study evaluated the in vitro bioaccessibility of Ca, Cu, Fe, K, Mg and Zn in bovine liver samples after traditional cooking in water and using the sous vide procedure. All heat treatments of bovine liver promoted the increase of the bioaccessibility of Ca, Cu, Fe, K and Mg, except for Zn when the effect was the opposite. The sous vide method provided higher bioaccessibility of these minerals than cooking in boiling water, except for K when both methods presented equivalent values. Samples of raw liver and liver cooked using sous vide method presented the following percentage of bioaccessible fraction, respectively: 39.7% and 95.8% (Ca), 8.78% and 26.9% (Cu), 8.80% and 39.5% (Fe), 30.2% and 42.6% (K), 26.4% and 43.9% (Mg), 24.8% and 36.3% (Zn). Thus, under the aspect of improvement availability of studied minerals by organism, the sous-vide technique was the most suitable to cook bovine liver. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Corrosion testing using isotopes

    Science.gov (United States)

    Hohorst, Frederick A.

    1995-12-05

    A method for determining the corrosion behavior of a material with respect to a medium in contact with the material by: implanting a substantially chemically inert gas in a matrix so that corrosion experienced by the material causes the inert gas to enter the medium; placing the medium in contact with the material; and measuring the amount of inert gas which enters the medium. A test sample of a material whose resistance to corrosion by a medium is to be tested, composed of: a body of the material, which body has a surface to be contacted by the medium; and a substantially chemically inert gas implanted into the body to a depth below the surface. A test sample of a material whose resistance to corrosion by a medium is to be tested, composed of: a substrate of material which is easily corroded by the medium, the substrate having a surface; a substantially chemically inert gas implanted into the substrate; and a sheet of the material whose resistance to corrosion is to be tested, the sheet being disposed against the surface of the substrate and having a defined thickness.

  20. Severe Environmental Corrosion Erosion Facility

    Data.gov (United States)

    Federal Laboratory Consortium — NETL’s Severe Environment Corrosion Erosion Facility in Albany, OR, allows researchers to safely examine the performance of materials in highly corrosive or erosive...

  1. Corrosion-resistant metallic coatings

    OpenAIRE

    F. Presuel-Moreno; M.A. Jakab; N. Tailleart; Goldman, M.; J. R. Scully

    2008-01-01

    We describe recent computational and experimental studies on the corrosion properties of metallic coatings that can be tailored (tuned) to deliver up to three corrosion-inhibiting functions to an underlying substrate. Attributes are tuned by a selection of alloy compositions and nanostructures, ideally in alloy systems that offer flexibility of choice to optimize the corrosion-resisting properties. An amorphous Al-based coating is tuned for corrosion protection by on-demand release of ionic i...

  2. Corrosion-resistant metal surfaces

    Science.gov (United States)

    Sugama, Toshifumi [Wading River, NY

    2009-03-24

    The present invention relates to metal surfaces having thereon an ultrathin (e.g., less than ten nanometer thickness) corrosion-resistant film, thereby rendering the metal surfaces corrosion-resistant. The corrosion-resistant film includes an at least partially crosslinked amido-functionalized silanol component in combination with rare-earth metal oxide nanoparticles. The invention also relates to methods for producing such corrosion-resistant films.

  3. Cook-chill, cook-freeze, cook-hold, sous vide: risks for hospital patients?

    Science.gov (United States)

    Wilkinson, P J; Dart, S P; Hadlington, C J

    1991-06-01

    Changes in eating habits and developments in food technology are occurring at the same time as an upward trend in foodborne infection in Britain. Vulnerable people such as the elderly and hospital patients are increasingly likely to consume food produced by new systems such as 'cook-chill' and 'cuisson sous vide'. The microbiological hazards of these systems are assessed as negligible, provided that production is controlled by appropriate methods such as the hazard analysis critical control point (HACCP) approach. The occurrence and control of bacterial contamination in a hospital cook-chill system is reviewed in this context.

  4. Leuconostoc rapi sp. nov., isolated from sous-vide cooked rutabaga

    DEFF Research Database (Denmark)

    Lyhs, Ulrike; Snauwaert, I.; Pihlajaviita, S.;

    2015-01-01

    .1 and 98.8% 16S rRNA gene sequence similarity towards the type strain, respectively). Phylogenetic analysis of the 16S rRNA gene, multilocus sequence analysis of the pheS, rpoA and atpA genes, and biochemical and genotypic characteristics allowed to differentiate strain LMG 27676T from all established......A Gram-positive, ovoid lactic acid bacterium, strain LMG 27676T, was isolated from a spoiled sous-vide cooked rutabaga. 16S rRNA gene sequence analysis indicated that the novel strain belongs to the genus Leuconostoc, with Leuconostoc kimchi and Leuconostoc miyukkimchii as nearest neighbours (99...

  5. Long-time water level observations at the HDR-testsite Soultz-sous-Forets

    Energy Technology Data Exchange (ETDEWEB)

    Dornstaedter, J.; Heinemann-Glutsch, B.; Zaske, J. [GTC-Kappelmeyer GmbH, Karlsruhe (Germany)

    1997-12-01

    Pressure or water level measurements have been performed by GTC in different wells at the geothermal testsite Soultz-sous-Forets for six years now. The water lever variations are mainly influenced by earth tides, barometric pressure variations, hydraulic testing and stimulation. The small scale variations are influenced by tidal and barometric forcing functions, the large scale variations by hydraulic testing and stimulation. By analyzing such measurements it is possible to get important information about the hydrualic connections between the boreholes, as well as aquifer parameters. (orig./AKF)

  6. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  7. Solving A Corrosion Problem

    Science.gov (United States)

    1979-01-01

    The corrosion problem, it turned out, stemmed from the process called electrolysis. When two different metals are in contact, an electrical potential is set up between them; when the metals are surrounded by an electrolyte, or a conducting medium, the resulting reaction causes corrosion, often very rapid corrosion. In this case the different metals were the copper grounding system and the ferry's aluminum hull; the dockside salt water in which the hull was resting served as the electrolyte. After identifying the source of the trouble, the Ames engineer provided a solution: a new wire-and-rod grounding system made of aluminum like the ferry's hull so there would no longer be dissimilar metals in contact. Ames research on the matter disclosed that the problem was not unique to the Golden Gate ferries. It is being experienced by many pleasure boat operators who are probably as puzzled about it as was the Golden Gate Transit Authority.

  8. Thin film corrosion. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Raut, M.K.

    1980-06-01

    Corrosion of chromium/gold (Cr/Au) thin films during photolithography, prebond etching, and cleaning was evaluated. Vapors of chromium etchant, tantalum nitride etchant, and especially gold etchant were found to corrosively attack chromium/gold films. A palladium metal barrier between the gold and chromium layers was found to reduce the corrosion from gold etchant.

  9. Corrosion resistant PEM fuel cell

    Science.gov (United States)

    Fronk, Matthew Howard; Borup, Rodney Lynn; Hulett, Jay S.; Brady, Brian K.; Cunningham, Kevin M.

    2002-01-01

    A PEM fuel cell having electrical contact elements comprising a corrosion-susceptible substrate metal coated with an electrically conductive, corrosion-resistant polymer containing a plurality of electrically conductive, corrosion-resistant filler particles. The substrate may have an oxidizable metal first layer (e.g., stainless steel) underlying the polymer coating.

  10. Influence of sous vide processing, steaming and boiling on vitamin retention and sensory quality in broccoli florets.

    Science.gov (United States)

    Petersen, M A

    1993-10-01

    In this study the effect of sous vide processing, steaming and traditional boiling of broccoli florets on retention of ascorbic acid, vitamin B6 and folacin was investigated. Freshly prepared samples were also sensorily evaluated. In all heat treatments ascorbic acid was found to have the highest retention, and was therefore judged not to be suitable as an indicator for vitamin retention in general. When the three types of heat treatment were compared, boiling showed lowest retention of all the vitamins examined (45-64% in 5 min), whereas sous-vide processing gave the highest retentions (97-100% in 5 min). Retentions during steaming were a little lower (83-100% in 5 min). Sensory evaluation showed that sous-vide cooked and steamed broccoli florets generally had higher acceptability than boiled.

  11. Changes provoked by boiling, steaming and sous-vide cooking in the lipid and volatile profile of European sea bass.

    Science.gov (United States)

    Nieva-Echevarría, Bárbara; Manzanos, María J; Goicoechea, Encarnación; Guillén, María D

    2017-09-01

    This study aims to shed light on the changes provoked by boiling, steaming and sous-vide cooking on the lipids and volatile profile of farmed and wild European sea bass meat. None of the cooking techniques provoked changes due to hydrolytic or oxidation processes detectable by (1)H NMR on sea bass lipids. The lipid profile of main and minor lipidic components was maintained after cooking. However, study by SPME-GC/MS evidenced that steaming and sous-vide cooking modified the volatile profile of sea bass meat, especially in farmed specimens. The compounds generated came from the occurrence, to a very small extent, of lipid and protein degradation. By contrast, boiling scarcely modified the initial characteristics of raw sea bass. Thus, from a sensory point of view and considering the odour-active compounds generated, steaming and sous-vide cooking provoked more noticeable changes than boiling, especially in farmed sea bass meat. Copyright © 2017. Published by Elsevier Ltd.

  12. Physico-Chemical and Structural Characteristics of Vegetables Cooked Under Sous-Vide, Cook-Vide, and Conventional Boiling

    OpenAIRE

    Iborra Bernad, María del Consuelo; García Segovia, Purificación; Martínez Monzó, Javier

    2015-01-01

    [EN] In this paper, physico-chemical and structural properties of cut and cooked purple-flesh potato, green bean pods, and carrots have been studied. Three different cooking methods have been applied: traditional cooking (boiling water at 100 °C), cook-vide (at 80 and 90 °C) and sous-vide (at 80 °C and 90 °C). Similar firmness was obtained in potato applying the same cooking time using traditional cooking (100 °C), and cook-vide and sous-vide at 90 °C, while in green beans and carrots the app...

  13. Vacuum brazing of metals (1961); Brassure sous vide des metaux (1961)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-07-01

    We have studied brazing in vacuum aiming its application for the making of containers and apparatus meant for high vacuum (p < 10{sup -8} torr). We first define the wettability of a brazing alloy on a metal and we remind the influence of the various parameters which act on this wettability (nature of the solid, of the liquid, geometrical and physicochemical state of the surface, metallurgical reactions occurring at the interface, temperature, time). We give then the results of the tests carried out in order to determine the conditions of wettability in vacuum of some brazing alloys on metals which can be used for the above mentioned apparatus (stainless steel, aluminium, bronze, titanium, zirconium, kovar, nickel, copper). (author) [French] Nous avons etudie la brasure sous vide en vue de son application a la construction d'enceintes et apparelilage destines a l'obtention des vides eleves (p < 10{sup -8} torr). Nous definissons d'abord la mouillabilite d'une brasure sur un metal et nous rappelons l'influence des differents parametres qui agissent sur cette mouillabilite (nature du solide, du liquide, etat geometrique et physico-chimique de la surface, reactions metallurgiques a l'interface, temperature, temps). Nous donnons ensuite les resultats des essais effectues dans le but de determiner les conditions de mouillabilite sous vide de certaines brassures sur des metaux utilisables dans les constructions mentionnees ci-dessus (acier inoxydable, bronze d'aluminium, titane, zirconium, kovar, nickel, cuivre). (auteur)

  14. Corrosion protection by anaerobiosis.

    Science.gov (United States)

    Volkland, H P; Harms, H; Wanner; Zehnder, A J

    2001-01-01

    Biofilm-forming bacteria can protect mild (unalloyed) steel from corrosion. Mild steel coupons incubated with Rhodoccocus sp. strain C125 and Pseudomonas putida mt2 in an aerobic phosphate-buffered medium containing benzoate as carbon and energy source, underwent a surface reaction leading to the formation of a corrosion-inhibiting vivianite layer [Fe3(PO4)2]. Electrochemical potential (E) measurements allowed us to follow the buildup of the vivianite cover. The presence of sufficient metabolically active bacteria at the steel surface resulted in an E decrease to -510 mV, the potential of free iron, and a continuous release of ferrous iron. Part of the dissolved iron precipitated as vivianite in a compact layer of two to three microns in thickness. This layer prevented corrosion of mild steel for over two weeks, even in a highly corrosive medium. A concentration of 20 mM phosphate in the medium was found to be a prerequisite for the formation of the vivianite layer.

  15. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  16. Corrosion potential analysis system

    Science.gov (United States)

    Kiefer, Karl F.

    1998-03-01

    Many cities in the northeastern U.S. transport electrical power from place to place via underground cables, which utilize voltages from 68 kv to 348 kv. These cables are placed in seamless steel pipe to protect the conductors. These buried pipe-type-cables (PTCs) are carefully designed and constantly pressurized with transformer oil to prevent any possible contamination. A protective coating placed on the outside diameter of the pipe during manufacture protects the steel pipe from the soil environment. Notwithstanding the protection mechanisms available, the pipes remain vulnerable to electrochemical corrosion processes. If undetected, corrosion can cause the pipes to leak transformer oil into the environment. These leaks can assume serious proportions due to the constant pressure on the inside of the pipe. A need exists for a detection system that can dynamically monitor the corrosive potential on the length of the pipe and dynamically adjust cathodic protection to counter local and global changes in the cathodic environment surrounding the pipes. The northeastern United States contains approximately 1000 miles of this pipe. This milage is critical to the transportation and distribution of power. So critical, that each of the pipe runs has a redundant double running parallel to it. Invocon, Inc. proposed and tested a technically unique and cost effective solution to detect critical corrosion potential and to communicate that information to a central data collection and analysis location. Invocon's solution utilizes the steel of the casing pipe as a communication medium. Each data gathering station on the pipe can act as a relay for information gathered elsewhere on the pipe. These stations must have 'smart' network configuration algorithms that constantly test various communication paths and determine the best and most power efficient route through which information should flow. Each network station also performs data acquisition and analysis tasks that ultimately

  17. Détection et isolation de défauts par analyse des contraintes géométriques de guidage-pilotage

    OpenAIRE

    Marzat, Julien; Piet-Lahanier, Hélène; Walter, Eric

    2010-01-01

    International audience; Cette communication présente une méthode de détection de défauts pour les systèmes aéronautiques. Pour réaliser leur mission, ces systèmes sont commandés à l'aide d'algorithmes de guidage-pilotage. Le diagnostic est ici considéré du point de vue de la réussite de la mission : si un défaut survient, la commande ne pourra plus être appliquée correctement. L'approche proposée vérifie donc l'adéquation du système aux contraintes géométriques imposées par la loi de guidage-...

  18. Scanning reference electrode techniques in localized corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Isaacs, H.S.; Vyas, B.

    1979-04-01

    The principles, advantages, and implementations of scanning reference electrode techniques are reviewed. Data related to pitting, intergranular corrosion, welds and stress corrosion cracking are presented. The technique locates the position of localized corrosion and can be used to monitor the development of corrosion and changes in the corrosion rate under a wide range of conditions.

  19. Corrosion Evaluation and Corrosion Control of Steam Generators

    Energy Technology Data Exchange (ETDEWEB)

    Maeng, W. Y.; Kim, U. C.; Sung, K. W.; Na, J. W.; Lee, Y. H.; Lee, D. H.; Kim, K. M

    2008-06-15

    Corrosion damage significantly influences the integrity and efficiency of steam generator. Corrosion problems of steam generator are unsolved issues until now even though much effort is made around world. Especially the stress corrosion cracking of heat exchange materials is the first issue to be solved. The corrosion protection method of steam generator is important and urgent for the guarantee of nuclear plant's integrity. The objectives of this study are 1) to evaluate the corrosion properties of steam generator materials, 2) to optimize the water chemistry of steam generator and 3) to develop the corrosion protection method of primary and secondary sides of steam generator. The results will be reflected to the water chemistry guideline for improving the integrity and efficiency of steam generator in domestic power plants.

  20. Quality evaluation of cook-chilled chicory stems (Cichorium intybus L., Catalogna group) by conventional and sous vide cooking methods.

    Science.gov (United States)

    Renna, Massimiliano; Gonnella, Maria; Giannino, Donato; Santamaria, Pietro

    2014-03-15

    Chicory stems, appreciated both raw and cooked, represent a nutritious and refined food. In this study the effects on the quality of stems cooked by conventional (boiling, steaming and microwaving) and innovative (sous vide) methods were analysed. Several physical, chemical and sensory traits were compared using two local varieties (Galatina and Molfettese) of southern Italy (Puglia region). Independently of the variety, the sous vide method did not significantly affect (redness, yellowness and hue angle) or had the least impact on (lightness and total colour difference) quality parameters among the four methods as compared with the raw product. Following sensory analysis, the sous vide product always showed the highest score among the cooking methods. Moreover, this innovative method did not affect total phenol (TP) content and antioxidant activity (AA) compared with uncooked stems of both varieties. Microwaving increased TP content and AA (though associated with higher weight loss), while different responses depending on the chicory variety were observed after boiling and steaming. The results indicate the sous vide technique as optimal to preserve several traits, including organoleptic ones, for the quality of cook-chilled chicory stems. They also provide product-specific information usually required for cooking process strategies in the industrial sector of ready-to-eat vegetables. © 2013 Society of Chemical Industry.

  1. Quality and safety of fish curry processed by sous vide cook chilled and hot filled technology process during refrigerated storage.

    Science.gov (United States)

    Shakila, R Jeya; Raj, B Edwin; Felix, N

    2012-06-01

    Fish curry, a traditional Indian dish was prepared from farmed fish Cobia (Rachycentron canadum), packaged by two different cook-chill processes namely, sous vide cook chilled and hot filled technology and held at 2 °C. Biochemical composition revealed that fish curry contained 5% protein and 6% fat. Omega-3 fatty acids, eicosapentaenoic acid (EPA) retained 55.44% while docosahexaenoic acid (DHA) retained 29% during cook-chilling process. The major fatty acids in fish curry were C18:2, C12:0, C16:0 and C18:1. Shelf-life of sous vide cook chilled and hot filled technology processed fish curry were 8 and 12 weeks, respectively. Total bacterial counts were detected after 4 weeks and 12 weeks in sous vide cook chilled and hot filled technology processes, respectively. Total staphylococci were detected in sous vide cook chilled and hot filled technology processed cobia fish curry after 4 and 12 weeks, respectively. Total bacilli, anaerobic sulfite reducing clostridia, Salmonella, and lactic acid bacteria were absent. Hot filled technology process was more efficient and could be applied for chilled fish curry preservation for 12 weeks without any safety problems.

  2. Effect of sous vide processing on physicochemical, ultrastructural, microbial and sensory changes in vacuum packaged chicken sausages.

    Science.gov (United States)

    Naveena, B M; Khansole, Panjab S; Shashi Kumar, M; Krishnaiah, N; Kulkarni, Vinayak V; Deepak, S J

    2017-01-01

    The processing of sous vide chicken sausages was optimized under vacuum packaging condition and cooking at 100 ℃ for 30 min (SV30), 60 min (SV60) and 120 min (SV120) and compared with aerobically cooked control at 100 ℃ for 30 min. Sous vide processing of chicken sausages (SV30) produced higher (p Sous vide processing of chicken sausages enriched with rosemary diterpene phenols retained the freshness and quality up to 120 days during storage at 4 ± 1 ℃ relative to control sausages that were spoiled on 20th day. Lipid oxidation and microbial growth remained below the spoilage levels for all the SV-processed sausages throughout the storage and addition of rosemary diterpene mixture at 0.02% v/w reduced the microbial growth and improved (p sous vide processing minimizes lipid oxidation and microbial growth of chicken sausages with improved product quality and shelf-life at 4 ± 1 ℃. © The Author(s) 2016.

  3. Guide pour la rédaction de cahiers des charges pour la sous-traitance en mécano-soudage

    CERN Document Server

    Cheminat, Olivier

    2016-01-01

    Ce rapport est principalement dédié aux rédacteurs de cahiers des charges lors de sous-traitance en soudage. Le choix de faire sous-traiter une fabrication et le choix du sous-traitant revêtent une triple dimension technique, économique et stratégique. Un sous-traitant n'est pas un simple fournisseur ; il est un véritable partenaire technique pour le donneur d'ordre qui lui confie la réalisation d'un produit qu'il a lui-même conçu. La sous-traitance nécessite alors, outre un audit préalable du partenaire, un suivi en continu, à distance, et une communication entre le donneur d'ordre et le sous-traitant. Le cahier des charges est un des éléments de cette communication. C'est un outil essentiel, notamment lorsque le marché est soumis à des normes, imposées par contrat entre le donneur d'ordre et le sous-traitant. Ce présent document est un guide pour la rédaction du document de consultation, afin d'être le plus précis et exhaustif possible, mais il ne saurait être utilisé pour établi...

  4. Corrosion-resistant metallic coatings

    Directory of Open Access Journals (Sweden)

    F. Presuel-Moreno

    2008-10-01

    Full Text Available We describe recent computational and experimental studies on the corrosion properties of metallic coatings that can be tailored (tuned to deliver up to three corrosion-inhibiting functions to an underlying substrate. Attributes are tuned by a selection of alloy compositions and nanostructures, ideally in alloy systems that offer flexibility of choice to optimize the corrosion-resisting properties. An amorphous Al-based coating is tuned for corrosion protection by on-demand release of ionic inhibitors to protect defects in the coating, by formation of an optimized barrier to local corrosion in Cl− containing environments, as well as by sacrificial cathodic prevention. Further progress in this field could lead to the design of the next generation of adaptive or tunable coatings that inhibit corrosion of underlying substrates.

  5. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch

    1997-01-01

    Measurements of corrosion rates and other parameters connected with corrosion processes are important, first as indicators of the corrosion resistance of metallic materials and second because such measurements are based on general and fundamental physical, chemical, and electrochemical relations....... Hence improvements and innovations in methods applied in corrosion research are likeliy to benefit basic disciplines as well. A method for corrosion measurements can only provide reliable data if the beckground of the method is fully understood. Failure of a method to give correct data indicates a need...... to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...

  6. Corrosion inhibitors from expired drugs.

    Science.gov (United States)

    Vaszilcsin, Nicolae; Ordodi, Valentin; Borza, Alexandra

    2012-07-15

    This paper presents a method of expired or unused drugs valorization as corrosion inhibitors for metals in various media. Cyclic voltammograms were drawn on platinum in order to assess the stability of pharmaceutically active substances from drugs at the metal-corrosive environment interface. Tafel slope method was used to determine corrosion rates of steel in the absence and presence of inhibitors. Expired Carbamazepine and Paracetamol tablets were used to obtain corrosion inhibitors. For the former, the corrosion inhibition of carbon steel in 0.1 mol L(-1) sulfuric acid solution was about 90%, whereas for the latter, the corrosion inhibition efficiency of the same material in the 0.25 mol L(-1) acetic acid-0.25 mol L(-1) sodium acetate buffer solution was about 85%.

  7. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch

    1997-01-01

    Measurements of corrosion rates and other parameters connected with corrosion processes are important, first as indicators of the corrosion resistance of metallic materials and second because such measurements are based on general and fundamental physical, chemical, and electrochemical relations....... Hence improvements and innovations in methods applied in corrosion research are likeliy to benefit basic disciplines as well. A method for corrosion measurements can only provide reliable data if the beckground of the method is fully understood. Failure of a method to give correct data indicates a need...... to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...

  8. Nuclear corrosion science and engineering

    CERN Document Server

    2012-01-01

    Understanding corrosion mechanisms, the systems and materials they affect, and the methods necessary for accurately measuring their incidence is of critical importance to the nuclear industry for the safe, economic and competitive running of its plants. This book reviews the fundamentals of nuclear corrosion. Corrosion of nuclear materials, i.e. the interaction between these materials and their environments, is a major issue for plant safety as well as for operation and economic competitiveness. Understanding these corrosion mechanisms, the systems and materials they affect, and the methods to accurately measure their incidence is of critical importance to the nuclear industry. Combining assessment techniques and analytical models into this understanding allows operators to predict the service life of corrosion-affected nuclear plant materials, and to apply the most appropriate maintenance and mitigation options to ensure safe long term operation. This book critically reviews the fundamental corrosion mechani...

  9. Microbiologically Influenced Corrosion

    Science.gov (United States)

    2009-01-01

    in each dimen- sion than bacteria and archaea. Fungi are eukaryotic organisms. Yeasts , molds, and mushrooms are examples of fungi. The majority of...occurs widely in natural waters and can be carried out by a variety of organisms including bacteria, yeast , and fungi (42). Ghiorse (43) prepared a...and its alloys is due to an aluminum oxide passive film. Anodizing produces thicker insulating films and better corrosion resistance. The natural

  10. Corrosion resistant coating

    Science.gov (United States)

    Wrobleski, Debra A.; Benicewicz, Brian C.; Thompson, Karen G.; Bryan, Coleman J.

    1997-01-01

    A method of protecting a metal substrate from corrosion including coating a metal substrate of, e.g., steel, iron or aluminum, with a conductive polymer layer of, e.g., polyaniline, coating upon said metal substrate, and coating the conductive polymer-coated metal substrate with a layer of a topcoat upon the conductive polymer coating layer, is provided, together with the resultant coated article from said method.

  11. CORROSION PROTECTION OF ALUMINUM

    Science.gov (United States)

    Dalrymple, R.S.; Nelson, W.B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred. (D.C.W.)

  12. Corrosion of bio implants

    Indian Academy of Sciences (India)

    U Kamachi Mudali; T M Sridhar; Baldev Raj

    2003-06-01

    Chemical stability, mechanical behaviour and biocompatibility in body fluids and tissues are the basic requirements for successful application of implant materials in bone fractures and replacements. Corrosion is one of the major processes affecting the life and service of orthopaedic devices made of metals and alloys used as implants in the body. Among the metals and alloys known, stainless steels (SS), Co–Cr alloys and titanium and its alloys are the most widely used for the making of biodevices for extended life in human body. Incidences of failure of stainless steel implant devices reveal the occurrence of significant localised corroding viz., pitting and crevice corrosion. Titanium forms a stable TiO2 film which can release titanium particles under wear into the body environment. To reduce corrosion and achieve better biocompatibility, bulk alloying of stainless steels with titanium and nitrogen, surface alloying by ion implantation of stainless steels and titanium and its alloys, and surface modification of stainless steel with bioceramic coatings are considered potential methods for improving the performance of orthopaedic devices. This review discusses these issues in depth and examines emerging directions.

  13. Corrosion in supercritical fluids

    Energy Technology Data Exchange (ETDEWEB)

    Propp, W.A.; Carleson, T.E.; Wai, Chen M.; Taylor, P.R.; Daehling, K.W.; Huang, Shaoping; Abdel-Latif, M.

    1996-05-01

    Integrated studies were carried out in the areas of corrosion, thermodynamic modeling, and electrochemistry under pressure and temperature conditions appropriate for potential applications of supercritical fluid (SCF) extractive metallurgy. Carbon dioxide and water were the primary fluids studied. Modifiers were used in some tests; these consisted of 1 wt% water and 10 wt% methanol for carbon dioxide and of sulfuric acid, sodium sulfate, ammonium sulfate, and ammonium nitrate at concentrations ranging from 0.00517 to 0.010 M for the aqueous fluids. The materials studied were Types 304 and 316 (UNS S30400 and S31600) stainless steel, iron, and AISI-SAE 1080 (UNS G10800) carbon steel. The thermodynamic modeling consisted of development of a personal computer-based program for generating Pourbaix diagrams at supercritical conditions in aqueous systems. As part of the model, a general method for extrapolating entropies and related thermodynamic properties from ambient to SCF conditions was developed. The experimental work was used as a tool to evaluate the predictions of the model for these systems. The model predicted a general loss of passivation in iron-based alloys at SCF conditions that was consistent with experimentally measured corrosion rates and open circuit potentials. For carbon-dioxide-based SCFs, measured corrosion rates were low, indicating that carbon steel would be suitable for use with unmodified carbon dioxide, while Type 304 stainless steel would be suitable for use with water or methanol as modifiers.

  14. Corrosion detection by induction

    Science.gov (United States)

    Roddenberry, Joshua L.

    Bridges in Florida are exposed to high amounts of humidity due to the state's geography. This excess moisture results in a high incidence of corrosion on the bridge's steel support cables. Also, the inclusion of ineffective waterproofing has resulted in additional corrosion. As this corrosion increases, the steel cables, responsible for maintaining bridge integrity, deteriorate and eventually break. If enough of these cables break, the bridge will experience a catastrophic failure resulting in collapse. Repairing and replacing these cables is very expensive and only increases with further damage. As each of the cables is steel, they have strong conductive properties. By inducing a current along each group of cables and measuring its dissipation over distance, a picture of structural integrity can be determined. The purpose of this thesis is to prove the effectiveness of using electromagnetic techniques to determine cable integrity. By comparing known conductive values (determined in a lab setting) to actual bridge values, the tester will be able to determine the location and severity of any damage, if present.

  15. Corrosion Monitors for Embedded Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Alex L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pfeifer, Kent B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Casias, Adrian L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorensen, Neil R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Missert, Nancy A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    We have developed and characterized novel in-situ corrosion sensors to monitor and quantify the corrosive potential and history of localized environments. Embedded corrosion sensors can provide information to aid health assessments of internal electrical components including connectors, microelectronics, wires, and other susceptible parts. When combined with other data (e.g. temperature and humidity), theory, and computational simulation, the reliability of monitored systems can be predicted with higher fidelity.

  16. Automated Methods of Corrosion Measurements

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    1997-01-01

    electrochemical measurements as well as elemental analysis look very promising for elucidating corrosion reaction mechanisms. The study of initial surface reactions at the atomic or submicron level is becoming an important field of research in the understanding of corrosion processes. At present, mainly two...... scanning microscope techniques are employed investigating corrosion processes, and usually in situ: in situ scanning tunneling microscopy (in situ STM) and in situ scanning force microscopy (in situ AFM). It is these techniques to which attention is directed here....

  17. Registration of vehicles at the Gex sous-préfecture: now by appointment only

    CERN Multimedia

    2016-01-01

    The Gex sous-préfecture has informed CERN that it has taken the following steps in order to reduce waiting times at its counters for the issue of carte grise vehicle registration certificates. As of 1 February 2016, you must book an appointment via the website http://www.rdv.ain.gouv.fr/ for all services relating to the registration of vehicles, in particular the:   change of the holder of a registration certificate, issue of a certificat de situation administrative (administrative status certificate required for the sale of a vehicle), change of marital status (or company name in the case of legal entities), change of address, change in the technical specification of the vehicle, corrections to registration certificates, equests for duplicates (loss or theft of registration certificates), registration of a diplomatic vehicle (CERN), registration of a new vehicle, registration of vehicles purchased tax-free in the Pays de Gex free zone (formerly TTW series), and import of vehicles (from ...

  18. Accès au tunnel sous la Manche (Terminal Transmanche)

    OpenAIRE

    2013-01-01

    Parallèlement aux travaux de construction du tunnel sous la Manche, l’emprise du chantier situé du côté français (Fig. n°1 : Localisation des zones fouillées) a fait l’objet (1986-1988) de prospections de surface, de sondages puis de fouilles de sauvetage sur les secteurs les plus sensibles. De par son ampleur (plus de 900 ha) et le caractère systématisé du traitement archéologique,cette opération reste une référence de première importance au plan régional, mais aussi national. Elle préfigu...

  19. Thermal inactivation of Listeria monocytogenes during rapid and slow heating in sous vide cooked beef.

    Science.gov (United States)

    Hansen, T B; Knøchel, S

    1996-06-01

    Heating at slowly rising temperatures is suspected to enhance thermotolerance in Listeria monocytogenes and, since anaerobic environments have been shown to facilitate resuscitation of heat-injured cells of this micro-organism, concern may arise about the possibility of L. monocytogenes surviving in minimally preserved products. The effect of rapid ( > 10 degrees C min-1) and slow (0.3 and 0.6 degrees C min-1) heating on survival of L. monocytogenes in sous vide cooked beef was therefore examined at mild processing temperatures of 56 degrees, 60 degrees and 64 degrees C. No statistically significant difference (P = 0.70) was observed between the tested heating regimes. Since the average pH of beef was low (5.6), and little or no effect was observed, a pH-dependency of heat shock-induced thermotolerance in L. monocytogenes is suggested to account for this result.

  20. Leuconostoc rapi sp. nov., isolated from sous-vide-cooked rutabaga.

    Science.gov (United States)

    Lyhs, Ulrike; Snauwaert, Isabel; Pihlajaviita, Seija; De Vuyst, Luc; Vandamme, Peter

    2015-08-01

    A Gram-stain-positive, ovoid, lactic acid bacterium, strain LMG 27676T, was isolated from a spoiled sous-vide-cooked rutabaga. 16S rRNA gene sequence analysis indicated that the novel strain belongs to the genus Leuconostoc, with Leuconostoc kimchii and Leuconostoc miyukkimchii as the nearest neighbours (99.1 and 98.8% 16S rRNA gene sequence similarity towards the type strain, respectively). Phylogenetic analysis of the 16S rRNA gene, multilocus sequence analysis of the pheS, rpoA and atpA genes, and biochemical and genotypic characteristics allowed differentiation of strain LMG 27676T from all established species of the genus Leuconostoc. Strain LMG 27676T ( = R-50029T = MHB 277T = DSM 27776T) therefore represents the type strain of a novel species, for which the name Leuconostoc rapi sp. nov. is proposed.

  1. Panel report on corrosion in energy systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    Corrosion problems in high-temperature (non aqueous) energy systems, corrosion in aqueous energy systems and institutional problems inhibiting the development of corrosion science and engineering are discussed. (FS)

  2. Panel report on corrosion in energy systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    Corrosion problems in high-temperature (non aqueous) energy systems, corrosion in aqueous energy systems and institutional problems inhibiting the development of corrosion science and engineering are discussed. (FS)

  3. Corrosion of copper by chlorine trifluoride; Corrosion du cuivre par le trifluorure de chlore

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-07-01

    chlore a ete effectuee, et controlee par chromatographie gazeuse, microsublimation et spectrographie infra-rouge. Les essais ont porte sur des cuivres de differentes puretes, principalement sur le cuivre a 99,999, sous forme de monocristaux. Ils ont comporte des cinetiques et la caracterisation des produits de corrosion dans differentes conditions de temperature et de pression. Les cinetiques ont montre des reactions du meme ordre de grandeur que celles obtenues avec le fluor-element. A pression atmospherique, il se forme du fluorure cuivrique et du chlorure cuivreux. La presence de ce compose permet d'ecarter definitivement l'assimilation du ClF{sub 3} a un simple agent fluorant. Aux basses pressions, un compose inconnu a ete caracterise. Il existe une tres forte presomption pour qu'il s'agisse du fluorure cuivreux instable, qui n'a pas pu etre encore isole. Un phenomene de germination a ete mis en evidence, montrant les analogies des phases initiales de fluoration avec celles de l'oxydation. Des effets importants resultant de la dissociation des fluorures de cuivre et de la solubilite du chlore dans ce metal ont ete mis en evidence. En dernier lieu, des essais ont montre l'influence considerable de la purete de la phase gazeuse et de la nature des parois sur les vitesses de corrosion qui peuvent dans certains cas etre multipliees par plusieurs puissances de dix. (auteur)

  4. EVHA, un logiciel d'évaluation de l'habitat du poisson sous Windows

    Directory of Open Access Journals (Sweden)

    GINOT V.

    1995-04-01

    Full Text Available EVHA est un logiciel destiné à l'évaluation de la capacité physique d'accueil des rivières vis-à-vis de certaines espèces de poissons cibles. Son approche est essentiellement graphique. Après avoir dépouillé les données topographiques et calé le modèle hydraulique, l'utilisateur étudie sa station selon les quatre représentations proposées, courbes fonction du débit, vues en plan, profils en long ou profils en travers. Les variables, Surface Pondérée Utile (SPU, SPU normée à 100 mètres, et valeur d'habitat, mais aussi surfaces mouillées, hauteurs d'eau, vitesses et nombres de Froude, volumes, peuvent être calculés soit en restant au niveau du point d'observation, soit en moyennant les valeurs par transect, par faciès, ou pour l'ensemble de la station. Les données générées peuvent être visualisées sous forme textuelle et exportées au format des principaux tableurs pour un traitement plus complet. Développé sous Windows, EVHA gère le «copier-coller», la sauvegarde des graphes au format vectoriel, l'impression et la gestion de la couleur et du noir et blanc. Sa bibliothèque de courbes de préférences peut s'enrichir des courbes produites par l'utilisateur.

  5. Lipid oxidation stability of omega-3- and conjugated linoleic acid-enriched sous vide chicken meat.

    Science.gov (United States)

    Narciso-Gaytán, C; Shin, D; Sams, A R; Keeton, J T; Miller, R K; Smith, S B; Sánchez-Plata, M X

    2011-02-01

    Lipid oxidation is known to occur rather rapidly in cooked chicken meat containing relatively high amounts of polyunsaturated fatty acids. To assess the lipid oxidation stability of sous vide chicken meat enriched with n-3 and conjugated linoleic acid (CLA) fatty acids, 624 Cobb × Ross broilers were raised during a 6-wk feeding period. The birds were fed diets containing CLA (50% cis-9, trans-11 and 50% trans-10, cis-12 isomers), flaxseed oil (FSO), or menhaden fish oil (MFO), each supplemented with 42 or 200 mg/kg of vitamin E (dl-α-tocopheryl acetate). Breast or thigh meat was vacuum-packed, cooked (74°C), cooled in ice water, and stored at 4.4°C for 0, 5, 10, 15, and 30 d. The lipid oxidation development of the meat was estimated by quantification of malonaldehyde (MDA) values, using the 2-thiobarbituric acid reactive substances analysis. Fatty acid, nonheme iron, moisture, and fat analyses were performed as well. Results showed that dietary CLA induced deposition of cis-9, trans-11 and trans-10, cis-12 CLA isomers, increased the proportion of saturated fatty acids, and decreased the proportions of monounsaturated and polyunsaturated fatty acids. Flaxseed oil induced higher deposition of C18:1, C18:2, C18:3, and C20:4 fatty acids, whereas MFO induced higher deposition of n-3 fatty acids, eicosapentaenoic acid (C20:5), and docosahexaenoic acid (C22:6; P 0.05) lipid oxidation development. In conclusion, dietary CLA, FSO, and MFO influenced the fatty acid composition of chicken muscle and the lipid oxidation stability of meat over the storage time. Supranutritional supplementation of vitamin E enhanced the lipid oxidation stability of sous vide chicken meat.

  6. Mechanisms of metal dusting corrosion

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo

    In this thesis the early stages of metal dusting corrosion is addressed; the development of carbon expanded austenite, C, and the decomposition hereof into carbides. Later stages of metal dusting corrosion are explored by a systematic study of stainless steel foils exposed to metal dusting...... influence of oxygen and carbon on the metal dusting corrosion is explored. The results indicate that exposure to metal dusting conditions have a detrimental effect on the resistance against oxidation and, conversely, that exposure to oxidation has a detrimental effect on the resistance towards metal dusting....... Consequently, a combination of carburizing and oxidizing conditions has a strong mutual catalyzing effect on the metal dusting corrosion....

  7. Evaluation of steel corrosion by numerical analysis

    OpenAIRE

    Kawahigashi, Tatsuo

    2017-01-01

    Recently, various non-destructive and numerical methods have been used and many cases of steel corrosion are examined. For example, methods of evaluating corrosion through various numerical methods and evaluating macrocell corrosion and micro-cell corrosion using measurements have been proposed. However, there are few reports on estimating of corrosion loss with distinguishing the macro-cell and micro-cell corrosion and with resembling an actuality phenomenon. In this study, for distinguishin...

  8. Archaeological analogs and corrosion; Analogues archeologiques et corrosion

    Energy Technology Data Exchange (ETDEWEB)

    David, D

    2008-07-01

    In the framework of the high level and long life radioactive wastes disposal deep underground, the ANDRA built a research program on the material corrosion. In particular they aim to design containers for a very long time storage. Laboratory experiments are in progress and can be completed by the analysis of metallic archaeological objects and their corrosion after hundred years. (A.L.B.)

  9. Mitigation of Corrosion on Magnesium Alloy by Predesigned Surface Corrosion

    Science.gov (United States)

    Zhang, Xuming; Wu, Guosong; Peng, Xiang; Li, Limin; Feng, Hongqing; Gao, Biao; Huo, Kaifu; Chu, Paul K.

    2015-11-01

    Rapid corrosion of magnesium alloys is undesirable in structural and biomedical applications and a general way to control corrosion is to form a surface barrier layer isolating the bulk materials from the external environment. Herein, based on the insights gained from the anticorrosion behavior of corrosion products, a special way to mitigate aqueous corrosion is described. The concept is based on pre-corrosion by a hydrothermal treatment of Al-enriched Mg alloys in water. A uniform surface composed of an inner compact layer and top Mg-Al layered double hydroxide (LDH) microsheet is produced on a large area using a one-step process and excellent corrosion resistance is achieved in saline solutions. Moreover, inspired by the super-hydrophobic phenomenon in nature such as the lotus leaves effect, the orientation of the top microsheet layer is tailored by adjusting the hydrothermal temperature, time, and pH to produce a water-repellent surface after modification with fluorinated silane. As a result of the trapped air pockets in the microstructure, the super-hydrophobic surface with the Cassie state shows better corrosion resistance in the immersion tests. The results reveal an economical and environmentally friendly means to control and use the pre-corrosion products on magnesium alloys.

  10. Stabilité sous condition CFL non linéaire

    Directory of Open Access Journals (Sweden)

    Deriaz Erwan

    2012-04-01

    Full Text Available We present a basic althought little known numerical stability condition: for convection equations, the von Neumann stability constraint ∥un + 1∥L2 ≤ (1 + C   Δt ∥un∥L2 drives to the stability condition Δt ≤ CΔxα with hbox{$alpha=frac{p(2q-1}{q(2p-1}$} α = p ( 2 q − 1 q ( 2 p − 1 where p is an integer linked to the stability domain of the time scheme and q ≥ p an integer linked to the upwind property of the space discretization (in the centered case we have q =  +∞ and hbox{$alpha=frac{2p}{2p-1}$} α = 2 p 2 p − 1 . Nous présentons une étude de stabilité aux conclusions originales : pour les équations de convection, la contrainte ∥un + 1∥L2 ≤ (1 + C   Δt∥un∥L2 fait apparaître la condition de stabilité Δt ≤ CΔxα avec hbox{$alpha=frac{p(2q-1}{q(2p-1}$} α = p ( 2 q − 1 q ( 2 p − 1 où p est un entier lié au domaine de stabilité du schéma en temps et q ≥ p un autre entier lié au caractère upwind de la discrétisation en espace (dans le cas centré, q =  +∞. Des exemples numériques montrent la pertinence de cette étude.

  11. Identification des fonctions et des contraintes principales liées à la réalisation des systèmes de sûreté du LHC

    CERN Document Server

    Cennini, E

    2000-01-01

    Dans la perspective de la spécification des systèmes de sûreté du LHC (systèmes de contrôle d'accès et de verrouillage des faisceaux), les études actuelles consistent à identifier les contraintes et les performances pour la définition des différentes fonctions requises. Du concept d'accès aux ouvrages souterrains du LHC et de l'expérience acquise dans la réalisation et l'exploitation de systèmes de sûreté découlent les spécifications des fonctions à implanter au niveau des couches Equipement, Contrôle et Supervision. Les fonctions des systèmes de sûreté sont soumises à un nombre élevé de contraintes et doivent satisfaire des critères de performances précis. Le présent document a pour objectif d'identifier les fonctions et les contraintes principales, de les classer selon leur nature, d'exprimer certains critères de performance et enfin de décrire leur impact sur les fonctions requises au niveau des couches énoncées ci-dessus. De cette analyse découleront des propositions con...

  12. General Corrosion and Localized Corrosion of Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon

    2004-10-01

    The waste package design for the License Application is a double-wall waste package underneath a protective drip shield (BSC 2004 [DIRS 168489]; BSC 2004 [DIRS 169480]). The purpose and scope of this model report is to document models for general and localized corrosion of the waste package outer barrier (WPOB) to be used in evaluating waste package performance. The WPOB is constructed of Alloy 22 (UNS N06022), a highly corrosion-resistant nickel-based alloy. The inner vessel of the waste package is constructed of Stainless Steel Type 316 (UNS S31600). Before it fails, the Alloy 22 WPOB protects the Stainless Steel Type 316 inner vessel from exposure to the external environment and any significant degradation. The Stainless Steel Type 316 inner vessel provides structural stability to the thinner Alloy 22 WPOB. Although the waste package inner vessel would also provide some performance for waste containment and potentially decrease the rate of radionuclide transport after WPOB breach before it fails, the potential performance of the inner vessel is far less than that of the more corrosion-resistant Alloy 22 WPOB. For this reason, the corrosion performance of the waste package inner vessel is conservatively ignored in this report and the total system performance assessment for the license application (TSPA-LA). Treatment of seismic and igneous events and their consequences on waste package outer barrier performance are not specifically discussed in this report, although the general and localized corrosion models developed in this report are suitable for use in these scenarios. The localized corrosion processes considered in this report are pitting corrosion and crevice corrosion. Stress corrosion cracking is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]).

  13. Caractérisation de l'état de surface et des contraintes résiduelles engendrées par meulage

    Science.gov (United States)

    Gognau, D.; Blehaut, H.; Dürr, J.; Hariri, S.; Khouchaf, L.; Flahaut, P.

    2002-07-01

    grinding operations are generally used to prepare surfaces or improve surface state before or after welding. These operations, when carried out manually with portable machines, induce superficial work hardening, modification of the structure of material and residual stresses. An experimental study about the influence of grinding has been carried out on two metallic materials, a low carbon steel (A42-CP) and an austenitic stainless steel (316L), in order to characterise the grinding effects. Manual grinding being difficult to control (no repeatable effects), a test rig using a portable machine has been made. This test rig enables to control the grinding parameters in order to obtain repeatable grinding operations. Characterisation of the ground surfaces was made by 2D profilometry and measurements of residual stresses have been carried out with a Set-X Elphyse apparatus. The profiles of residual stresses obtained show, on the one hand, that on each material, identical grindings generate identical states of stresses and on the other hand, that materials have not the same behaviour, From a metallurgical point of view, we also observe that the grinding effects are different for both materials. The grinding of the A42 steel highlights a crushing of the grain near the surface while the 316L stainless steel grinding reveals sliding bands. Des opérations de meulage sont régulièrement effectuées sur des matériaux métalliques pour préparer les surfaces ou pour améliorer l'état de ces surfaces après soudage. Ces opérations réalisées manuellement engendrent un écrouissage superficiel, une modification de la structure du matériau et par conséquent des contraintes résiduelles. Une étude expérimentale a été menée sur un acier à bas carbone (A42-CP) et un acier inoxydable austénitique (316L) afin de caractériser les effets du meulage. Le meulage manuel étant difficile à maîtriser (effets non reproductibles), un banc d'essai utilisant une machine

  14. DPC materials and corrosion environments.

    Energy Technology Data Exchange (ETDEWEB)

    Ilgen, Anastasia Gennadyevna; Bryan, Charles R.; Teich-McGoldrick, Stephanie; Hardin, Ernest

    2014-10-01

    After an exposition of the materials used in DPCs and the factors controlling material corrosion in disposal environments, a survey is given of the corrosion rates, mechanisms, and products for commonly used stainless steels. Research needs are then identified for predicting stability of DPC materials in disposal environments. Stainless steel corrosion rates may be low enough to sustain DPC basket structural integrity for performance periods of as long as 10,000 years, especially in reducing conditions. Uncertainties include basket component design, disposal environment conditions, and the in-package chemical environment including any localized effects from radiolysis. Prospective disposal overpack materials exist for most disposal environments, including both corrosion allowance and corrosion resistant materials. Whereas the behavior of corrosion allowance materials is understood for a wide range of corrosion environments, demonstrating corrosion resistance could be more technically challenging and require environment-specific testing. A preliminary screening of the existing inventory of DPCs and other types of canisters is described, according to the type of closure, whether they can be readily transported, and what types of materials are used in basket construction.

  15. Agricultural Polymers as Corrosion Inhibitors

    Science.gov (United States)

    Agricultural polymers were composed of extra-cellular polysaccharides secreted by Leuconostoc mesenteroides have been shown to inhibit corrosion on corrosion-sensitive metals. The substantially pure exopolysaccharide has a general structure consisting of alpha(1-6)-linked D-glucose backbone and appr...

  16. INHIBITION OF CORROSION

    Science.gov (United States)

    Atherton, J.E. Jr.; Gurinsky, D.H.

    1958-06-24

    A method is described for preventing corrosion of metallic container materials by a high-temperature liquid bismuth flowing therein. The method comprises fabricating the containment means from a steel which contains between 2 and 12% chromium, between 0.5 and 1.5% of either molybdenum and silicon, and a minimum of nickel and manganese, and maintaining zirconium dissolved in the liquid bismuth at a concentration between 50 parts per million and its saturation value at the lowest temperature in the system.

  17. Fatigue and Corrosion in Metals

    CERN Document Server

    Milella, Pietro Paolo

    2013-01-01

    This textbook, suitable for students, researchers and engineers, gathers the experience of more than 20 years of teaching fracture mechanics, fatigue and corrosion to professional engineers and running experimental tests and verifications to solve practical problems in engineering applications. As such, it is a comprehensive blend of fundamental knowledge and technical tools to address the issues of fatigue and corrosion. The book initiates with a systematic description of fatigue from a phenomenological point of view, since the early signs of submicroscopic damage in few surface grains and continues describing, step by step, how these precursors develop to become mechanically small cracks and, eventually, macrocracks whose growth is governed by fracture mechanics. But fracture mechanics is also introduced to analyze stress corrosion and corrosion assisted fatigue in a rather advanced fashion. The author dedicates a particular attention to corrosion starting with an electrochemical treatment that mechanical e...

  18. Mesures de contraintes in-situ. Méthode de relaxation des carottes Measuring in-Situ Stresses. Relaxation Method with Core Samples

    Directory of Open Access Journals (Sweden)

    Perreau P.

    2006-11-01

    Full Text Available Dans cet article, on se propose de présenter les premiers résultats de l'étude de la méthode d'évaluation des contraintes par mesure de déformations différées d'une carotte après son extraction. Le travail correspondant a été réalisé dans le cadre du projet ARTEP Fracturation hydraulique . Les principes de cette méthode et les quelques éléments d'interprétation récemment publiés dans la littérature sont exposés dans un premier temps. Les résultats de deux campagnes de mesures sur deux puits de la SNEA-P (Soudron, novembre 1985 et Lanot, juillet 1986 sont ensuite présentés. Ces essais ont mis en évidence que les déformations différées d'une carotte dues au relachement des contraintes sont effectivement mesurables. Cependant, une interprétation quantitative de ces mesures nécessite une amélioration des conditions expérimentales (stabilisation thermique, stabilisation de l'état de saturation. This article describes the first results of research on a method of evaluating stresses by measuring the differred deformations of a core sample after it has been extracted. The corresponding research was done within the framework of an ARTEP project on Hydraulic Fracturing . The principles of this method and several interpretation aspects published recently in the literature are described in the first part. Then the results of two measurement campaigns using two SNEA-P wells (Soudron in November 1985 and Lanot in July 1986 are described. These tests revealed that the differed deformations of a core sample due to the relaxing of stresses can effectively be measured. However, a quantitative interpretation of these measurements requires an improvement to be made in the experimental conditions (thermal stabilization, stabilization of the state of saturation.

  19. EXPRESSION IN VIVO DU GÈNE GFP SOUS LA FORME D’UNE PROTÉINE DE FUSION

    Directory of Open Access Journals (Sweden)

    Lucian Negura

    2006-08-01

    Full Text Available La protéine GFP (Green Fluorescent Protein se caractérise par sa capacité à émettre sous l’action des rayons UV une lumière verte de basse énergie, ce qui la rend particulièrement utile en biotechnologies. Nous avons procédé à la production de la GFP in vivo par Eschericha coli sous forme d’une protéine chimère de fusion avec le peptide de la –Galactosidase. Pour ce, nous avons cloné un fragment d’ADN comportant la phase codante de la GFP à partir d’un vecteur dans lequel il ne peut être exprimé vers un autre vecteur permettant lui cette expression.

  20. Kinetic modeling to study the quality of tambaqui (Colossoma macropomum) sous vide during storage at different temperatures.

    Science.gov (United States)

    Ramos, Fabiane C P; Ribeiro, Suezilde C A; Peixoto Joele, Maria R S; Sousa, Consuelo L; Lourenço, Lúcia F H

    2017-07-01

    This study aimed to assess the changes in quality of tambaqui sous vide during refrigerated storage using degradation kinetics. Tambaqui sous vide was prepared and stored at three temperatures (1, 4, 10 °C). The microorganism counts and the physicochemical analyses were analyzed every three days. The results obtained were fitted to the Labuza models and by Arrhenius equation. The results of the microbiological and physicochemical analyses obtained better fits to the zero-order model. The Arrhenius equation better fit to the velocity constants of the zero-order model, which showed that the changes in the values of attributes are related to temperature. Higher Ea values were found for the microorganism counts than for the physicochemical parameters, which proves the greater dependency of microorganisms on variations in temperature. The assessment of changes in quality based on temperature allows the storage conditions to be optimized.

  1. Effects of combined electron-beam irradiation and sous-vide treatments on microbiological and other qualities of chicken breast meat

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuzzaman, K.; Lucht, L.; Chuaqui-Offermanns, N

    1994-07-01

    The microbiological safety, refrigeration shelf-life, and nutritional quality of chicken breast meat were investigated following combined electron-beam irradiation and cooking under vacuum (sous-vide). Chicken breast meat inoculated with 10{sup 6} CFU/g of Listeria monocytogenes was irradiated with an electron beam at doses up to 3.1 kGy under vacuum in barrier bags, cooked in a boiling water bath for 3 min 45 s (previously determined to achieve an internal temperature of 71.1{sup o}C), and stored at 8{sup o}C for up to 5 weeks. Listeria was undetectable in samples treated with combined sous-vide and irradiation at 3.1 kGy, but the organism survived the sous-vide treatment without irradiation and multiplied during storage. A similar study, conducted with uninoculated chicken breast meat, revealed that the product which received both irradiation (3 kGy) and sous-vide treatment had a shelf-life of at least 8 weeks at 8{sup o}C, whereas the unirradiated samples treated sous-vide spoiled in 16 days. Listeria was undetectable in combination treated samples, but some of the unirradiated sous-vide samples tested after long storage showed high levels of Listeria. Some loss of thiamine occurred with the combined treatments. (author)

  2. IN DRIFT CORROSION PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    D.M. Jolley

    1999-12-02

    As directed by a written development plan (CRWMS M&O 1999a), a conceptual model for steel and corrosion products in the engineered barrier system (EBS) is to be developed. The purpose of this conceptual model is to assist Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift, thus allowing PAO to provide a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near-Field Environment (NFE) Revision 2 (NRC 1999). This document provides the conceptual framework for the in-drift corrosion products sub-model to be used in subsequent PAO analyses including the EBS physical and chemical model abstraction effort. This model has been developed to serve as a basis for the in-drift geochemical analyses performed by PAO. However, the concepts discussed within this report may also apply to some near and far-field geochemical processes and may have conceptual application within the unsaturated zone (UZ) and saturated zone (SZ) transport modeling efforts.

  3. O poema como exílio: Sousândrade-Guesa em “O inferno de Wall Street”

    Directory of Open Access Journals (Sweden)

    Ana Carolina Cernicchiaro

    2007-01-01

    Full Text Available This essay intends to read in O Guesa, of Joaquim de Sousândrade, a sort of exile-poem. A desert where the poet is an eternal errant, a stranger in his own language, where the representation is not possible anymore and what remains is multi-idiomatic fragmentation, roars, babbles, cacophonies, cries, screams and inversions. A between-place of discords, rupture and deflection, of combat language inside the language.

  4. Observations sur le sous-genre des Pouillots (Ficedula), et notamment sur le Pouillot Lusciniole, Sylvia (fic.) Polyglotta, de Vieillot

    NARCIS (Netherlands)

    Schlegel, H.

    1848-01-01

    Les oiseaux dont nous nous proposons de traiter, forment un petit sous-genre démembré de celui des becs-fins ou Sylvia de Latham. C’est, à proprement parler, à BECHSTEIN que l’on en doit l’établissement, quoique cet auteur l’ait pris dans un sens plus ou moins différent de celui que nous y attachons

  5. Corrosion Prevention and Control Applications Guide

    Science.gov (United States)

    1987-03-31

    Money, Manpower Called Keys to Progress, Aviation Week & Space Technology, October 6, 1980. 12. Reboul , M. C., Galvanic Corrosion of Aluminum, National...PA, April 1980. 25. Reboul , M.C., Galvanic Corrosion of Aluminum, National Association of Corrosion Engineers, Corrosion, V. 35#9, September 1979. 146

  6. Investigation on Atmospheric Corrosiveness in Hainan Province

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    According to the results of four-year exposure tests for carbon steel samples in Hainan province, the influences of meteorological factors and Cl- on atmospheric corrosion were investigated. The feature of atmospheric corrosion in this area was summarized. A corrosive map for the area was drawn. The corrosion products on carbon steel at some typical places were analyzed by XRD and XPS.

  7. Recognition and Analysis of Corrosion Failure Mechanisms

    Directory of Open Access Journals (Sweden)

    Steven Suess

    2006-02-01

    Full Text Available Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, material evaluation, data review and conclusion procurement. In analyzing corrosion failures, one must recognize the wide range of common corrosion mechanisms. The features of any corrosion failure give strong clues as to the most likely cause of the corrosion. This article details a proven approach to properly determining the root cause of a failure, and includes pictographic illustrations of the most common corrosion mechanisms, including general corrosion, pitting, galvanic corrosion, dealloying, crevice corrosion, microbiologically-influenced corrosion (MIC, corrosion fatigue, stress corrosion cracking (SCC, intergranular corrosion, fretting, erosion corrosion and hydrogen damage.

  8. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

    2011-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

  9. Patrimonialiser les bases de sous-marins et le Mur de l’Atlantique

    Directory of Open Access Journals (Sweden)

    Claude Prelorenzo

    2011-06-01

    Full Text Available Le Mur de l’Atlantique court de la frontière espagnole jusqu’au nord de la Norvège. Au sein de ce dispositif sont installées cinq bases de sous-marins : Dunkerque, Saint-Nazaire, Lorient, La Rochelle et Bordeaux. Après une période de purgatoire, liée aux souvenirs trop frais des bombardements qu’ils ont attirés sur les villes, les édifices du mur sont entrés dans la sphère de la culture et du tourisme. Nous posons alors la question suivante : de quoi ces édifices portent-ils témoignage, et nous envisageons plusieurs aspects : leur évident modernisme qui les situe à un moment de l’histoire de l’architecture, leur hétérogénéité qui fait de ces bâtiments des sortes d’ovni, sans aucun rapport ni d’échelle ni de forme avec l’architecture civile, une technique d’enfouissement et de camouflage génératrice d’un nouveau paysage. Mais ces édifices peuvent-ils être exonérés de leur but guerrier ? Quel est le message de leur recyclage dans le culturel, le festif ou le commercial ? Deux bases de sous-marins sont plus particulièrement présentées, celle de Saint-Nazaire et celle de Lorient.The Atlantic Wall stretches from the Spanish border to northern Norway. Within this system there are five bases for submarines: Dunkirk, Saint-Nazaire, Lorient, La Rochelle and Bordeaux. After a period of purgatory, with the painful memories of the wartime air raids which destroyed the cities around the bases, the buildings which the Atlantic Wall comprises have now entered the spheres of culture and tourism. What do these buildings bear witness to? Their frank modernism puts them at a precise moment in the history of architecture. Their heterogeneity makes them like UFOs, without any relation of scale or form to civil architecture. Their specific techniques of dissimulation and camouflage created new landscapes. But can these buildings be freed from the memories of their original military purpose? What message is

  10. Integral modeling and financial impact of the geothermal situation and power plant at Soultz-sous-Forêts

    Science.gov (United States)

    Heidinger, Philipp

    2010-07-01

    The science about deep Enhanced Geothermal Systems (EGS) is still an emerging process and for further spreading economics is the key of the technology. To understand the financial situation, a program for economic evaluation was developed. This software (Euronaut) is completely modularized and considers all cash flows. Projects like an EGS are wrapped into tree-like structures. Based on the results which were gained at Soultz-sous-Forêts, two configurations were designed. The first EGS configuration consists of a simplified two well (doublet) system where the dependencies of all components (mainly the reservoir, wells, pumps and the heat-to-power conversion unit) are physically and economically linked together. The realization of these dependencies and their complex interactions enable a sensitivity analysis of the borehole depth and reservoir depth, respectively. As a result, depth dependent effective costs and revenues of an EGS plant with the geohydrological characteristics of Soultz-sous-Forêts are determined. As a future development, the second configuration will adapt the actual situation at Soultz-sous-Forêts with the individual features of all four wells (GPK1 - GPK4). Then, this model can be used for all kinds of sensitivity analyses to clarify the impact of certain components or to optimize the operation scheme; e.g. the flow rates.

  11. Some peculiarities of corrosion of wheel steel

    Directory of Open Access Journals (Sweden)

    Alexander SHRAMKO

    2009-01-01

    Full Text Available Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosion nucleation and their influence on corrosion depends on type of inclusion. Mechanism of corrosion of wheel steel corrosion was discussed.

  12. Diffusion Coatings as Corrosion Inhibitors

    Science.gov (United States)

    Ivanov, Radoslav; Ignatova-Ivanova, Tsveteslava

    2016-03-01

    Corrosion is the cause of irretrievable loss of huge amounts of metals and alloys. The harmful effects of corrosion can be reduced significantly by applying appropriate methods of corrosion protection. One method to protect metals against corrosion is the formation of diffusion coatings on them. High corrosion resistance is typical for the boride diffusion layers. Aluminothermy is one of the main methods for diffusion saturation of the surface of metal products with various elements, including boron, and under certain conditions with aluminum, too. Samples of steel 45 were put to aluminothermic diffusion saturation with boron in a pressurized steel container at a temperature of 1100K, for 6 hours in powdered aluminothermic mixtures. The content of B2O3 in the starting mixtures decreased from the optimum - 20% to 0%, and the content of Al and the activator - (NH4)2.4BF3 is constant, respectively 7% and 0.5%. Al2O3 was used as filler. The borided samples were tested for corrosion resistance in 10% HCl for 72 hours. The results show that their corrosion resistance depends on the composition of the starting saturating mixture (mainly on the content of B2O3), and respectively on the composition, structure, thickness and degree of adhesion of the layer to the metal base.

  13. Corrosion behavior of duplex coatings

    Directory of Open Access Journals (Sweden)

    K. Raghu Ram Mohan Reddy

    2016-07-01

    Full Text Available The titanium alloys are used in defense, aerospace, automobile, chemical plants and biomedical applications due to their very high strength and lightweight properties. However, corrosion is a life-limiting factor when Ti alloys are exposed to different chemical environments at high temperatures. In the present paper, duplex NiCrAlY/WC–Co coating is coated onto Ti6Al4V substrate to investigate the corrosion behavior of both coated samples and the substrate. The duplex coating was performed with NiCrAlY as the intermediate coat of 200 μm thickness deposited by HVOF process and WC–Co ceramic top coat with varying thicknesses of 250 μm, 350 μm and 450 μm deposited by DS process. Potentiodynamic polarization tests were employed to investigate the corrosion performance of duplex coated samples and substrate in Ringer’s solution at 37 °C and pH value was set to 5.7. Finally the results reveal that 350 μm thick coated samples showed highest corrosion resistance compared to 250 μm thick samples as well as bare substrate. However, the 450 μm thick coated sample showed poor corrosion resistance compared to the substrate. The scale formed on the samples upon corrosion was characterized by using SEM analysis to understand the degree of corrosion behavior.

  14. Diffusion Coatings as Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    Ivanov Radoslav

    2016-03-01

    Full Text Available Corrosion is the cause of irretrievable loss of huge amounts of metals and alloys. The harmful effects of corrosion can be reduced significantly by applying appropriate methods of corrosion protection. One method to protect metals against corrosion is the formation of diffusion coatings on them. High corrosion resistance is typical for the boride diffusion layers. Aluminothermy is one of the main methods for diffusion saturation of the surface of metal products with various elements, including boron, and under certain conditions with aluminum, too. Samples of steel 45 were put to aluminothermic diffusion saturation with boron in a pressurized steel container at a temperature of 1100K, for 6 hours in powdered aluminothermic mixtures. The content of В2О3 in the starting mixtures decreased from the optimum - 20% to 0%, and the content of Al and the activator - (NH42.4BF3 is constant, respectively 7% and 0.5%. Al2O3 was used as filler. The borided samples were tested for corrosion resistance in 10% HCl for 72 hours. The results show that their corrosion resistance depends on the composition of the starting saturating mixture (mainly on the content of В2О3, and respectively on the composition, structure, thickness and degree of adhesion of the layer to the metal base.

  15. Corrosion protection and control using nanomaterials

    CERN Document Server

    Cook, R

    2012-01-01

    This book covers the use of nanomaterials to prevent corrosion. The first section deals with the fundamentals of corrosion prevention using nanomaterials. Part two includes a series of case studies and applications of nanomaterials for corrosion control.$bCorrosion is an expensive and potentially dangerous problem in many industries. The potential application of different nanostructured materials in corrosion protection, prevention and control is a subject of increasing interest. Corrosion protection and control using nanomaterials explores the potential use of nanotechnology in corrosion control. The book is divided into two parts. Part one looks at the fundamentals of corrosion behaviour and the manufacture of nanocrystalline materials. Chapters discuss the impact of nanotechnology in reducing corrosion cost, and investigate the influence of various factors including thermodynamics, kinetics and grain size on the corrosion behaviour of nanocrystalline materials. There are also chapters on electrodeposition ...

  16. Contraintes climatiques dans les Préalpes françaises : évolution récente et conséquences potentielles futures

    Directory of Open Access Journals (Sweden)

    Sandra Rome

    2010-12-01

    Full Text Available Le climat des Alpes françaises reste encore mal décrit, et sa variabilité interannuelle est difficile à étudier du fait des spécificités topoclimatiques locales et du manque de séries climatiques longues. Les conséquences régionales du changement de certaines contraintes climatiques sur plusieurs secteurs d’activité sont pourtant redoutées. Cet article propose donc un diagnostic des variations climatiques contemporaines (1959-2009 à l’échelle des Préalpes du Nord (Vercors et Chartreuse en utilisant des chroniques stationnelles pluviothermiques. Les changements observés sont ensuite mis en relation avec des impacts connus ou potentiels sur les activités socio-économiques régionales.The climate of the French Alps remains poorly described, and its interannual variability is difficult to study because of the wide variety of local topoclimatic characteristics and the lack of available long-term time-series. Regional consequences by certain climatic threat on various economic activities are nevertheless expected. This article thus proposes a diagnosis of the contemporary climatic variations (1959-2009 on the scale of French northern Prealps (Vercors and Chartreuse by using the time series of 4 reference stations. Observed changes are then related to known or potential impacts on the regional socioeconomic activities.

  17. Developpement d'une plateforme de calcul d'equilibres chimiques complexes et adaptation aux problemes electrochimiques et d'equilibres contraints

    Science.gov (United States)

    Neron, Alex

    Avec l'arrivée de l'environnement comme enjeu mondial, le secteur de l'efficacité énergétique prend une place de plus en plus importante pour les entreprises autant au niveau économique que pour l'image de la compagnie. Par le fait même, le domaine des technologies de l'énergie est un créneau de recherche dont les projets en cours se multiplient. D'ailleurs, un des problèmes qui peut survenir fréquemment dans certaines entreprises est d'aller mesurer la composition des matériaux dans des conditions difficiles d'accès. C'est le cas par exemple de l'électrolyse de l'aluminium qui se réalise à des températures très élevées. Pour pallier à ce problème, il faut créer et valider des modèles mathématiques qui vont calculer la composition et les propriétés à l'équilibre du système chimique. Ainsi, l'objectif global du projet de recherche est de développer un outil de calcul d'équilibres chimiques complexes (plusieurs réactions et plusieurs phases) et l'adapter aux problèmes électrochimiques et d'équilibres contraints. Plus spécifiquement, la plateforme de calcul doit tenir compte de la variation de température due à un gain ou une perte en énergie du système. Elle doit aussi considérer la limitation de l'équilibre due à un taux de réaction et enfin, résoudre les problèmes d'équilibres électrochimiques. Pour y parvenir, les propriétés thermodynamiques telles que l'énergie libre de Gibbs, la fugacité et l'activité sont tout d'abord étudiées pour mieux comprendre les interactions moléculaires qui régissent les équilibres chimiques. Ensuite, un bilan énergétique est inséré à la plateforme de calcul, ce qui permet de calculer la température à laquelle le système est le plus stable en fonction d'une température initiale et d'une quantité d'énergie échangée. Puis, une contrainte cinétique est ajoutée au système afin de calculer les équilibres pseudo-stationnaires en évolution dans le temps. De plus, la

  18. Corrosion Protection of Electrically Conductive Surfaces

    OpenAIRE

    Jian Song; Liangliang Wang; Andre Zibart; Christian Koch

    2012-01-01

    The basic function of the electrically conductive surface of electrical contacts is electrical conduction. The electrical conductivity of contact materials can be largely reduced by corrosion and in order to avoid corrosion, protective coatings must be used. Another phenomenon that leads to increasing contact resistance is fretting corrosion. Fretting corrosion is the degradation mechanism of surface material, which causes increasing contact resistance. Fretting corrosion occurs when there is...

  19. Critical Study of Corrosion Damaged Concrete Structures

    OpenAIRE

    Sallehuddin Shah Ayop; John Cairns

    2013-01-01

    Corrosion of steel reinforcement in concrete is one of the major problems with respect to the durability of reinforced concrete structures. The degradation of the structure strength due to reinforcement corrosion decreases its design life. This paper presents the literature study on the influence of the corrosion on concrete structure starting from the mechanism of the corrosion until the deterioration stage and the structural effects of corrosion on concrete structures.

  20. Shutdown corrosion in geothermal energy systems

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, Peter F.

    1982-10-08

    Experience has shown that corrosion occurring during geothermal energy utilization system downtime--shutdown corrosion--can pose a serious threat to successful operations. Shutdown corrosion in geothermal plants appears more severe than would be expected in their nongeothermal analogs, and its mitigation may pose a severe challenge to corrosion engineering personnel. This paper presents four case histories of geothermal shutdown corrosion problems. General methods of mitigation are explored.

  1. Cracking and corrosion recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Suik, H. [Tallinn Technical University, Horizon Pulp and Paper, Tallinn (Estonia)

    1998-12-31

    The corrosion of heat surfaces and the cracking the drums are the main problems of the recovery boiler. These phenomena have been appeared during long-term operation of boiler `Mitsubishi - 315` erected at 1964. Depth of the crack is depending on the number of shutdowns and on operation time. Corrosion intensity of different heat surfaces is varying depend on the metal temperature and the conditions at place of positioning of tube. The lowest intensity of corrosion is on the bank tubes and the greatest is on the tubes of the second stage superheater and on the tubes at the openings of air ports. (orig.) 5 refs.

  2. Corrosion-resistant coating development

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.; Kupp, D.M.; Martin, R.L. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    SiC-based heat exchangers have been identified as the prime candidate material for use as heat exchangers in advanced combined cycle power plants. Unfortunately, hot corrosion of the SiC-based materials created by alkali metal salts present in the combustion gases dictates the need for corrosion-resistant coatings. The well-documented corrosion resistance of CS-50 combined with its low (and tailorable) coefficient of thermal expansion and low modulus makes CS-50 an ideal candidate for this application. Coatings produced by gelcasting and traditional particulate processing have been evaluated.

  3. Corrosion-resistant sulfur concretes

    Science.gov (United States)

    McBee, W. C.; Sullivan, T. A.; Jong, B. W.

    1983-04-01

    Sulfur concretes have been developed by the Bureau of Mines as construction materials with physical and mechanical properties that suit them for use in acid and salt corrosive environments where conventional concretes fail. Mixture design methods were established for preparing sulfur concretes using different types of aggregates and recently developed mixed-modified sulfur cements. Bench-scale testing of the sulfur concretes has shown their potential value. Corrosion resistance, strength, and durability of sulfur concrete are superior to those of conventional materials. Field in situ evaluation tests of the sulfur concretes as replacement for conventional concrete materials are in progress in corrosive areas of 24 commercial chemical, fertilizer, and metallurgical plants.

  4. Review on Stress Corrosion and Corrosion Fatigue Failure of Centrifugal Compressor Impeller

    Institute of Scientific and Technical Information of China (English)

    SUN Jiao; CHEN Songying; QU Yanpeng; LI Jianfeng

    2015-01-01

    Corrosion failure, especially stress corrosion cracking and corrosion fatigue, is the main cause of centrifugal compressor impeller failure. And it is concealed and destructive. This paper summarizes the main theories of stress corrosion cracking and corrosion fatigue and its latest developments, and it also points out that existing stress corrosion cracking theories can be reduced to the anodic dissolution (AD), the hydrogen-induced cracking (HIC), and the combined AD and HIC mechanisms. The corrosion behavior and the mechanism of corrosion fatigue in the crack propagation stage are similar to stress corrosion cracking. The effects of stress ratio, loading frequency, and corrosive medium on the corrosion fatigue crack propagation rate are analyzed and summarized. The corrosion behavior and the mechanism of stress corrosion cracking and corrosion fatigue in corrosive environments, which contain sulfide, chlorides, and carbonate, are analyzed. The working environments of the centrifugal compressor impeller show the behavior and the mechanism of stress corrosion cracking and corrosion fatigue in different corrosive environments. The current research methods for centrifugal compressor impeller corrosion failure are analyzed. Physical analysis, numerical simulation, and the fluid-structure interaction method play an increasingly important role in the research on impeller deformation and stress distribution caused by the joint action of aerodynamic load and centrifugal load.

  5. Improvement of microbiological safety of sous-vide meals by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, J. E-mail: huto@omega.kee.hu; Polyak-Feher, K.; Andrassy, E.; Meszaros, L

    2002-03-01

    Experimental batches of smoked-cured pork in stewed beans sauce were inoculated with spores of psychrotrophic Bacillus cereus, more heat and radiation resistant than spores of non-proteolytic C. botulinum. After vacuum packaging, the meals were treated with combinations of pasteurizing heat treatments and gamma irradiation of 5 kGy. Prior and after treatments, and periodically during storage at 10 deg. C, total aerobic and total anerobic viable cell counts, and selectively, the viable cell counts of B. cereus and sulphite-reducing clostridia have been determined. The effects of the treatment order as well as addition of nisin to enhance the preservative efficiency of the physical treatments were also studied. Heat-sensitization of bacterial spores surviving irradiation occurred. The quality-friendly sous-vide cooking in combination with this medium dose gamma irradiation and/or nisin addition increased considerably the microbiological safety and the keeping quality of the meals studied. However, approx. 40% loss of thiamin content occurred as an effect of combination treatments, and adverse sensorial effects may also limit the feasible radiation doses or the usable concentrations of nisin.

  6. Sous l’empire de la folie : Moby-Dick, Shakespeare & compagnie

    Directory of Open Access Journals (Sweden)

    Michel Imbert

    2010-10-01

    Full Text Available This article aims at translating Moby-Dick back into Shakespeare’s ornate lingo, and back again into a Swiftian or Sternian brand of “jabberwocky,” in order to expose the sheer nonsense that underlies lame attempts at standing for the Body Politic called Leviathan, understanding it, or making sense of the whale as a whole.Melville emprunte à Shakespeare le motif de la volonté de puissance, du rêve d’empire sous l’emprise de la folie du pouvoir. Le drame d’Achab est de s’ériger en maître absolu face au Leviathan et de s’ignorer possédé par la folle du logis, l’hysterica passio qui habite Lear et qui lui souffle, dans tous les sens du terme, son rêve dément de domination. L’histoire cherche à se répéter sur le modèle des tragédies de Shakespeare mais finit par dégénérer en farce. Le délire de Pip achève de la faire sombrer dans le non-sens.

  7. Installation for analytic chemistry under irradiation; Installation de chimie analytique sous rayonnement

    Energy Technology Data Exchange (ETDEWEB)

    Fradin, J.; Azoeuf, P.; Guillon, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    An installation has been set up for carrying out manipulations and chemical analyses on radioactive products. It is completely remote-controlled and is of linear shape, 15 metres long; it is made up of three zones: - an active zone containing the apparatus, - a rear zone giving access to the active zone, - a forward zone independent of the two others and completely protected from which the remote-control of the apparatus is effected. The whole assembly has been designed so that each apparatus corresponding to an analytical technique is set up in a sealed enclosure. The sealed enclosures are interconnected by a conveyor. After three years operation, a critical review is now made of the installation. (authors) [French] L'installation a ete realisee pour effectuer des manipulations et des analyses chimiques sur des produits radioactifs. Elle est totalement telecommandee et se presente sous une forme lineaire de 15 metres de longueur et comporte trois zones: - une zone active d'appareillage, - une zone arriere d'intervention, - une zone avant independante des deux premieres et totalement protegee, ou s'operent les telecommandes de l'appareillage. L'ensemble a ete concu de facon a ce que chaque appareillage correspondant a une technique d'analyse soit implante dans une enceinte etanche. Les enceintes etanches sont reliees entre elles par un convoyeur. Apres trois annees de fonctionnement nous faisons le bilan et les critiques de l'installation. (auteurs)

  8. Improvement of microbiological safety of sous-vide meals by gamma radiation

    Science.gov (United States)

    Farkas, J.; Polyák-Fehér, K.; Andrássy, É.; Mészáros, L.

    2002-03-01

    Experimental batches of smoked-cured pork in stewed beans sauce were inoculated with spores of psychrotrophic Bacillus cereus, more heat and radiation resistant than spores of non-proteolytic C. botulinum. After vacuum packaging, the meals were treated with combinations of pasteurizing heat treatments and gamma irradiation of 5 kGy. Prior and after treatments, and periodically during storage at 10°C, total aerobic and total anerobic viable cell counts, and selectively, the viable cell counts of B. cereus and sulphite-reducing clostridia have been determined. The effects of the treatment order as well as addition of nisin to enhance the preservative efficiency of the physical treatments were also studied. Heat-sensitization of bacterial spores surviving irradiation occurred. The quality-friendly sous-vide cooking in combination with this medium dose gamma irradiation and/or nisin addition increased considerably the microbiological safety and the keeping quality of the meals studied. However, approx. 40% loss of thiamin content occurred as an effect of combination treatments, and adverse sensorial effects may also limit the feasible radiation doses or the usable concentrations of nisin.

  9. Thermal inactivation of Listeria monocytogenes and Salmonella spp. in sous-vide processed marinated chicken breast.

    Science.gov (United States)

    Karyotis, Dimitrios; Skandamis, Panagiotis N; Juneja, Vijay K

    2017-10-01

    The heat resistance of a cocktail of five Salmonella strains and five L. monocytogenes strains was determined in teriyaki-marinated chicken breasts. Inoculated meat, packaged in bags, were completely immersed in a circulating water bath and cooked to a final temperature of 55, 57.5 or 60°C in 1h, and then held for predetermined times. The surviving Salmonella and L. monocytogenes cells were enumerated by surface plating on XLD agar and Palcam agar, respectively. D-values, determined by linear regression, of Salmonella in chicken breast ranged from 47.65min at 55°C to 7.48min at 60°C; the values for L. monocytogenes ranged from 54.81min at 55°C to 10.39min at 60°C. Marination rendered the pathogen more sensitive to the lethal effect of heat. The results of this study will assist the food industry in ensuring microbiological safety of sous-vide processed marinated chicken breasts. Published by Elsevier Ltd.

  10. Etude de conception d’une traversée sous vide 30 kV

    CERN Document Server

    Prost, A

    2011-01-01

    Dans le cadre de la construction du nouveau distributeur à ferrites BIDIS situé dans la ligne de transfert du Linac4 vers l’injecteur Booster du complexe PS, il est nécessaire de réaliser un nouveau développement de traversée haute tension pour assurer l’alimentation de ces septa sous vide. De manière à éviter toute pollution des enceintes de l’accélérateur en cas de fuite de vide, il a été choisi de développer une traversée n’utilisant ni liquide, ni gaz isolant. Cette technologie nous incite à faire une étude de design plus poussée, dans le choix des formes géométriques des pièces constituant ces traversées, ainsi que des distances à respecter entre les différentes parties soumises à la haute tension, afin d’éviter tous claquages ou apparition de courant limitant la tenue à la haute tension.

  11. Shelf Life of Chicken Meat Balls Submitted to Sous Vide Treatment

    Directory of Open Access Journals (Sweden)

    ÖP Can

    2015-06-01

    Full Text Available The objective of this study was to investigate the appropriate temperature for processing storage of chicken meatballs made of minced chicken meat with the sous vide method. The chicken meatballs were prepared and separated into four experimental groups according to the application of heat treatment (10 and 20 minutes and storage time (+2 and +10°C. Sensory, microbiological (total aerobic mesophilic bacteria, total psychrotrophs, lactic acidbacteria, Enterobacteriaceae, Clostridiumperfringens, Listeria spp., chemical (pH, thiobarbituric acid, color (L*, a*, b* values, and texture profile analyses were performed on meatball samples. Cl. perfringens and Listeria spp. were not detected in meatball samples during the storage period. Samples cooked at 10 minute and stored at +2°C the highest count of total aerobic mesophilic bacteria (p<0.05. For lipid oxidation, interaction was observed between cooking time and storage temperature, with higher TBARs values for samples stored at 10 °C, while cooking time and storage temperature showed no influence on the color and textural analysis parameters. For the treatments evaluated, cooking time x storage temperature seem affect more microbiological and chemical parameters than color and textural parameters of chicken meatballs.

  12. Spoilage of sous vide cooked salmon (Salmo salar) stored under refrigeration.

    Science.gov (United States)

    Díaz, P; Garrido, M D; Bañón, S

    2011-02-01

    The spoilage of Sous Vide 'SV' cooked salmon stored under refrigeration was studied. Samples were packaged under vacuum in polyamide-polypropylene pouches, cooked at an oven temperature/time of 80 (°)C/45 min, quickly chilled at 3 (°)C and stored at 2 (°)C for 0, 5 or 10 weeks for catering use. Microbial (aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae), physical-chemical (pH, water activity, TBARS, acidity, L*a*b* color, texture profile analysis and shear force) and sensory (appearance, odor, flavor, texture and overall quality) parameters were determined. SV processing prevented the growth of aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae. There were no relevant changes in pH, water activity, TBARS, CIELab color associated with cooked salmon spoilage. Instrumental texture data were contradictory. Slight decrease in lactic acid levels was found. In contrast, the SV cooked salmon suffered considerable sensory deterioration during its refrigerated storage, consisting of severe losses of cooked salmon odor and flavor, slight rancidity, discoloration associated with white precipitation, and moderates softness, and loss of chewiness and juiciness. No acidification, putrefaction or relevant rancidity was detected. The sensory spoilage preceded microbiological and physical-chemical spoilage, suggesting that microbiological quality alone may overestimate the shelf life of SV cooked salmon.

  13. Effect of salt addition on sous vide cooked whole beef muscles from Argentina.

    Science.gov (United States)

    Vaudagna, S R; Pazos, A A; Guidi, S M; Sanchez, G; Carp, D J; Gonzalez, C B

    2008-07-01

    Sodium chloride (NaCl, 0-1.4%) and sodium tripolyphosphate (STPP, 0-0.5%) were added to Semitendinosus muscles and submitted to sous vide cooking at different temperatures (55-75°C). The effects of these three factors on pH, cooking loss, instrumental colour parameters, protein solubilization and distribution, and micro- and ultra-structure were evaluated. Quadratic surface responses equations were obtained from data (pH, cooking loss and colour parameters) as a function of the salts concentrations and cooking temperature. Both salts - alone or in combination - successfully reduced cooking loss. The best results were obtained for the combinations 0.25%STPP+1.20%NaCl and 0.25%STPP+0.70%NaCl, and temperatures between 60 and 65°C. Under these conditions, cooking loss was reduced close to 0%. pH was only dependent on STPP concentration, with a threshold concentration value of 0.25%. Temperature increment and NaCl addition produced a redness reduction. STPP incorporation recovered partially this parameter in comparison to non-added samples. Microscopy and SDS-PAGE results support the effect of the selected combinations of factors, suggesting that both salts together induced protein solubilization and gelation upon heating.

  14. Development of a convenience and safety chilled sous vide fish dish: Diversification of aquacultural products.

    Science.gov (United States)

    Espinosa, M C; López, G; Díaz, P; Linares, M B; Garrido, M D

    2016-04-01

    The dynamic expansion of the ready-to-eat seabream sector in its adaptation to new lifestyles has led to the search for new presentation formats in seabream (Sparus aurata). Green sauce (olive oil, wine vinegar, garlic, fresh parsley, black pepper, basil and salt) and 60 ℃ of cooking temperature were chosen by the panellists for the sous vide cooking process. Seabream fillet and sauce were packaged in polypropylene trays, cooked, chilled and stored at 2 ℃. Microbiological (total viable counts,Enterobacteriaceae,lactic acid bacteria, anaerobic psychrotrophic, moulds and yeasts, Salmonella and Listeria monocytogenes), chemical (pH and TBARs) and sensory parameters were determined at 0, 7, 17, 34, 48 and 62 days. In the conditions used, the microbiological counts remained stable, and Salmonella and Listeria monocytogenes were absent. The acidic sauce had a positive effect on the pH of the product, and low TBARs were obtained throughout storage. The processing conditions used in the present study allowed a chilled ready-to-eat seabream product of consistently high quality up to 62 days of storage to be obtained, representing an expansion of the products offered by the aquacultural industry. © The Author(s) 2015.

  15. Erosion--Corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, B.

    1978-01-01

    The deterioration of materials by corrosion or erosion by itself presents a formidable problem and for this reason investigators have studied these two phenomena independently. In fact, there are very few systematic studies on E-C and the majority of references mention it only in passing. In most real systems, however, the two destructive processes take place simultaneously, hence the purpose of this review is to present the various interactions between the chemical and mechanical agents leading to accelerated degradation of the material. The papers cited in the review are those that lead to a better understanding of the process involved in the accelerated rate of material loss under E-C conditions.

  16. Greener Approach towards Corrosion Inhibition

    Directory of Open Access Journals (Sweden)

    Neha Patni

    2013-01-01

    Full Text Available Corrosion control of metals is technically, economically, environmentally, and aesthetically important. The best option is to use inhibitors for protecting metals and alloys against corrosion. As organic corrosion inhibitors are toxic in nature, so green inhibitors which are biodegradable, without any heavy metals and other toxic compounds, are promoted. Also plant products are inexpensive, renewable, and readily available. Tannins, organic amino acids, alkaloids, and organic dyes of plant origin have good corrosion-inhibiting abilities. Plant extracts contain many organic compounds, having polar atoms such as O, P, S, and N. These are adsorbed on the metal surface by these polar atoms, and protective films are formed, and various adsorption isotherms are obeyed. Various types of green inhibitors and their effect on different metals are mentioned in the paper.

  17. Corrosion Problems in Absorption Chillers

    Science.gov (United States)

    Stetson, Bruce

    1978-01-01

    Absorption chillers use a lithium bromide solution as the medium of absorption and water as the refrigerant. Discussed are corrosion and related problems, tests and remedies, and cleaning procedures. (Author/MLF)

  18. Accelerated corrosion test and corrosion failure distribution model of aircraft structural aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    LIU Wen-lin; MU Zhi-tao; JIN Ping

    2006-01-01

    Based on corrosion damage data of 10 years for a type of aircraft aluminum alloy, the statistical analysis was conducted by Gumbel, Normal and two parameters Weibull distribution function. The results show that aluminum alloy structural member has the corrosion history of pitting corrosion-intergranular corrosion-exfoliation corrosion, and the maximum corrosion depth is in conformity to normal distribution. The accelerated corrosion test was carried out with the complied equivalent airport accelerated environment spectrum. The corrosion damage failure modes of aluminum alloy structural member indicate that the period of validity of the former protective coating is about 2.5 to 3 years, and that of the novel protective coating is about 4.0 to 4.5 years. The corrosion kinetics law of aluminum spar flange was established by fitting corrosion damage test data. The law indicates two apparent corrosion stages of high strength aluminum alloy section material: pitting corrosion and intergranular corrosion/exfoliation corrosion.The test results agree with the statistical fit result of corrosion data collected from corrosion member in service. The fractional error is 5.8% at the same calendar year. The accelerated corrosion test validates the corrosion kinetics law of aircraft aluminum alloy in service.

  19. Electrochemical Studies of Atmospheric Corrosion.

    Science.gov (United States)

    1979-01-01

    Todynamlc polarization curves using a mod ifiedatmospheric corrosion mon i tor (ACM). Norma l Tafel behavior was observed , the limiting current for oxygen...following a suggestion of Peter Serada, who is heading a task group on time-of-wetness measurements In ASTM GO1 .04, in which the author is participating...about 5 papers except for 1968 where a symposium on atmospheric corrosion was held which resulted in the publ ication of an ASTM Special Technical

  20. Corrosion Control Anniston Army Depot

    Science.gov (United States)

    2010-02-09

    parts. • Anodize, Chrome, and Black Oxide (et.al.) • Substrate Prep and CARC paint. Stowage • Climate controlled storage (limited). • Weather...resistant (rain, uv) stowage . • Right Material – Right Time In Process Actions Bldgs 129 and 114 • Installation of new cleaning technologies for small... Rack Dehydration Prep Area CARC Application Flash-Off Oven De-mask and Anti- Corrosion App. Planned Future Actions Survey • Perform a corrosion survey

  1. Materials selection and corrosion problems

    Energy Technology Data Exchange (ETDEWEB)

    Cornet, I.; Greif, R.; Treseder, R.S.

    1974-06-28

    Data tabulated for chemical composition of geothermal waters are presented for four areas of interest in Nevada: Beowawe steam well and Beowawe Hot Spring, Buffalo Valley Hot Springs, Kyle Hot Springs, and Leach Hot Springs. Material recommendations were prepared for the Nevada geothermal well. A detailed field corrosion test program planned for the Nevada test well is included. A progress report is presented for a laboratory research program on velocity effects in corrosion. (MHR)

  2. Maintainability Improvement Through Corrosion Prediction

    Science.gov (United States)

    1997-12-01

    potential, current, pH, and chloride ion concentration were made along a simulated corrosion fatigue crack for HY80 (UNS K31820) steel in seawater...frequency range of 0.05-50 Hz, a 7075-T6 aluminium alloy and 304 and 316L stainless steels were fatigue tested in 3.0% NaCl solution. The increments...DESCRIPTORS: Conference Paper; Aluminum base alloys- Mechanical properties; Austenitic stainless steels - Mechanical properties; Corrosion fatigue

  3. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  4. Investigations on Atmospheric Corrosion of Low carbon Steel in ...

    African Journals Online (AJOL)

    Nafiisah

    2008-07-17

    Jul 17, 2008 ... index which is directly related to the weight loss due to corrosion. The corrosion index ... easily observed by visual inspection, and the robust Gaussian filter was used. .... Method of removal of corrosion products from corrosion.

  5. Migrating corrosion inhibitor protection of concrete

    Energy Technology Data Exchange (ETDEWEB)

    Bjegovic, D.; Miksic, B.

    1999-11-01

    Migrating corrosion inhibitors (MCI) were developed to protect steel rebar from corrosion in concrete. They were designed to be incorporated as an admixture during concrete batching or used for surface impregnation of existing concrete structures. Two investigations are summarized. One studied the effectiveness of MCIs as a corrosion inhibitor for steel rebar when used as an admixture in fresh concrete mix. The other is a long-term study of MCI concrete impregnation that chronicles corrosion rates of rebar in concrete specimens. Based on data from each study, it was concluded that migrating corrosion inhibitors are compatible with concrete and effectively delay the onset of corrosion.

  6. Solutions of corrosion Problems in advanced Technologies

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Karlsson, Asger

    1999-01-01

    Austenitic and ferritic steels were exposed in the superheater area of a straw-fired CHP plant. The specimens were exposed for 1400 hours at 450-600°C. The rate of corrosion was assessed based on unattacked metal remaining. The corrosion products and course of corrosion for the various steel types...... were investigated using light optical and scanning electron microscopy. The ferritic steels suffered from corrosion mainly via material loss. The austenitic steels suffered from predominantly selective corrosion resulting in chromium depletion from the alloy. A clear trend was observed that selective...... corrosion increased with increasing chromium content of the alloy....

  7. Sigand : une application SIG sous androïd (tablette de la gestion des chantiers

    Directory of Open Access Journals (Sweden)

    CHAKIB SAFAR BATI

    2016-12-01

    Full Text Available L’introduction de données terrain pour les études environnementales ou de gestion de l’espace, régionales ou locales est une nécessité incontournable pour la validation des traitements et des interprétations mais aussi pour fournir des compléments d’informations aux divers travaux. Mais ce retour terrain est également de plus en plus demandé pour les gestionnaires de chantiers et de projets qui ont une exigence de contrôle ou de suivi et donc d’une information temps réel sur l’avancement des travaux, autrement pour introduire de nouvelles informations sur la base de données géoréférencées. Les avancées technologiques en matière de manipulation de l’information géographique (GPS, tablette graphique, téléphone portable, réalité augmentée permettent d’espérer la mise à dispositiondes professionnels, voire d’un plus large public, des outils adéquats pour de tels travaux. Actuellement, les outils d’élaboration, de gestion et d’exploitation des bases de données géographiques (solutions SIG ne sont pas encore complètement opérationnels en version « tablette » ; des applications telles que Qgis ou ArcGis sous Androïd attendent encore des développements. Nous présentons ici la première version d’une application SIG sous Androïd (disponible sur tablette pour la gestion en temps réel des chantiers qui permet de charger des couches vectorielles et de les mettre à jour sur le terrain en fonction de l’observation directe ; les couches (préalablement géoréférencées sont projetées sur des fonds cartographiques fournis par un serveur cartographique Google Maps (Route, Satellite, terrain; dans le cas d’absence de connexion internet, le fond cartographique est ramené d’un cache. Nous utilisons SpatialiteAndroïd pour le stockage et la manipulation des données géographiques. Le contrôleur de cartes Google Maps est employé pour afficher en mode cartographique les données stockées dans

  8. Corrosion behavior of corrosion resistant alloys in stimulation acids

    Energy Technology Data Exchange (ETDEWEB)

    Cheldi, Tiziana [ENI E and P Division, 20097 San Donato Milanese Milano (Italy); Piccolo, Eugenio Lo; Scoppio, Lucrezia [Centro Sviluppo Materiali, via Castel Romano 100, 00128 Rome (Italy)

    2004-07-01

    In the oil and gas industry, selection of CRAs for downhole tubulars is generally based on resistance to corrosive species in the production environment containing CO{sub 2}, H{sub 2}S, chloride and in some case elemental sulphur. However, there are non-production environments to which these materials must also be resistant for either short term or prolonged duration; these environments include stimulation acids, brine and completion fluids. This paper reports the main results of a laboratory study performed to evaluate the corrosion and stress corrosion behaviour to the acidizing treatments of the most used CRAs for production tubing and casing. Laboratory tests were performed to simulate both 'active' and 'spent' acids operative phases, selecting various environmental conditions. The selected steel pipes were a low alloyed steel, martensitic, super-martensitic, duplex 22 Cr, superduplex 25 Cr and super-austenitic stainless steels (25 Cr 35 Ni). Results obtained in the 'active' acid environments over the temperature range of 100-140 deg. C, showed that the blend acids with HCl at high concentration and HCl + HF represented too much severe conditions, where preventing high general corrosion and heavy localised corrosion by inhibition package becomes very difficult, especially for duplex steel pipe, where, in some case, the specimens were completely dissolved into the solution. On the contrary, all steels pipes were successfully protected by inhibitor when organic acid solution (HCOOH + CH{sub 3}COOH) were used. Furthermore, different effectiveness on corrosion protection was showed by the tested inhibitors packages: e.g. in the 90% HCl at 12% + 10 CH{sub 3}COOH acid blend. In 'spent' acid environments, all steel pipes showed to be less susceptible to the localised and general corrosion attack. Moreover, no Sulphide Stress Corrosion Cracking (SSC) was observed. Only one super-austenitic stainless steel U-bend specimen showed

  9. European HDR research programme at Soultz-sous-Forets (France) 1987-1996

    Energy Technology Data Exchange (ETDEWEB)

    Baria, R.; Baumgaertner, J.; Gerard, A. [SOCOMINE, Projet Geothermique, Soultz-sous-Forets (France); Jung, R. [BGR, Hannover (Germany); Garnish, J. [DGXII, European Commission, Brussels (Belgium)

    1999-10-01

    The site at Soultz-sous-Forets (France) has been selected as the future European HDR research site (Garnish, J., Baria, R., Baumgaertner, J., Gerard, A., 1994. GRC Trans. 18, 431-438; Baria, R., 1990. Proceedings of Camborne School of Mines. International HDR Conference, June 1989, p. 613. Robertson Scientific Publications, London). Since 1987, extensive testing of the underground has been carried out using a single well (GPK1), initially to a depth of 2000 m and then to a depth of around 3590 m. From 1995 onwards the testing of the underground has utilized two deep wells. The hydraulic tests carried out in 1993-1994 demonstrated the potential of the site as a future European Scientific Prototype. In particular, the tests showed that in the Rhine graben the fracture network in the basement is well-developed, with a degree of permeability. While some minor fluid movement occurs naturally, hydraulic simulation has been shown to increase substantially the overall transmissivity. The Soultz site has been used for testing a modified or alternative facet of the concept of HDR developed in recent years. The geological setting also offers other advantages in terms of relatively low stimulation pressures, a characteristic that may simplify the task of developing a promising circulation system. A second deep well (GPK2) was drilled late in 1994, with the aim of developing circulation between the two deep wells. In 1995, GPK2 was stimulated for the first time and a short circulation test was attempted between the two deep wells. During 1996, GPK2 was stimulated again using higher flow rates to improve the injectivity further. It is planned to install the necessary infrastructure to carry out, during 1997, a 4-month circulation test at around 25 kg/s, using a downhole pump to produce from GPK2 and reinjecting the produced fluid into GPK1.

  10. Induced seismicity in EGS reservoir : analysis of persistent multiplets at Soultz-sous-Forêts, France

    Science.gov (United States)

    Cauchie, Léna; Lengliné, Olivier; Schmittbuhl, Jean

    2017-04-01

    Abundant seismicity is generally observed during the exploitation of geothermal reservoirs, especially during phases of hydraulic stimulations. At the Enhanced Geothermal System of Soultz-Sous-Forêts in France, the induced seismicity has been thoroughly studied over the years of exploitation and the mechanism at its origin has been related to both fluid pressure increase during stimulation and aseismic creeping movements. The fluid-induced seismic events often exhibit a high degree of similarity and the mechanism at the origin of these repeated events is thought to be associated with slow slip process where asperities on the rupture zone act several times. In order to improve our knowledge on the mechanisms associated with such events and on the damaged zones involved during the hydraulic stimulations, we investigate the behaviour of the multiplets and their persistent nature, if it prevails, over several water injection intervals. For this purpose, we analysed large datasets recorded from a downhole seismic network for several water injection periods (1993, 2000, …). For each stimulation interval, thousands of events are recorded at depth. We detected the events using the continuous kurtosis-based migration method and classified them into families of comparable waveforms using an approach based on cross-correlation analysis. We obtain precise relative locations of the multiplets using differential arrival times obtained through cross-correlation of similar waveforms. Finally, the properties of the similar fluid-induced seismic events are derived (magnitude, spectral content) and examined over the several hydraulic tests. Hopefully these steps will lead to a better understanding of the repetitive nature of these events and the investigation of their persistence will outline the heterogeneities of the structures (temperatures anomalies, regional stress perturbations, fluid flow channelling) regularly involved during the different stimulations.

  11. Fracture mapping in the Soultz-sous-Forêts geothermal field using microearthquake locations

    Science.gov (United States)

    Michelet, Sophie; ToksöZ, M. Nafi

    2007-07-01

    In 2003, a massive hydraulic fracturing experiment was carried out at the European Geothermal Hot Dry Rock site at Soultz-sous-Forêts, France. The 2 week injection of water generated a high level of microseismic activity, triggering about 90,000 microearthquakes during and after the fluid injection. Of these, 21,000 events, detected at all stations, were located individually with a grid search algorithm to characterize the extent of the seismic zones and ultimately of the fracture network. The accuracy of these initial locations was around 70 m, not sufficient to map detailed fracture patterns. A precise relocation effort was undertaken to reduce the location uncertainties using three different techniques: joint hypocenter determination (JHD), collapsing and multiplet analysis. The collapsing method was added to the JHD results to further consolidate the hypocenters. On the other hand, a multiplet analysis was performed on the initial data set for identifying microearthquakes with similar waveforms and hence relocating relatively the correlated events. The delays in traveltime were computed by wavelet analysis and the events were relocated using a grid search algorithm. We found 7463 events whose seismograms correlated with a correlation coefficient of 0.8 or higher, most of which were doublets. Multiplets are horizontal tube-like structures with lengths from a hundred to several hundred meters striking along the direction of the maximum compressive horizontal stress. We interpret these structures as the preferential paths where fluid flow is largely confined. This hypothesis is reinforced by the good correlation in depth between the events and the fluid outflows observed in the well. Therefore we believe that these relocated events highlight the zones where the permeability of the reservoir is increased.

  12. Nutritional advantages of sous-vide cooking compared to boiling on cereals and legumes: Determination of ashes and metals content in ready-to-eat products.

    Science.gov (United States)

    Rondanelli, Mariangela; Daglia, Maria; Meneghini, Silvia; Di Lorenzo, Arianna; Peroni, Gabriella; Faliva, Milena Anna; Perna, Simone

    2017-05-01

    In order to guarantee the highest quality of ready-to-eat cereals and legumes, two different cooking methods have been applied: traditional cooking and sous-vide. Ashes and metals content (magnesium, potassium, iron, zinc, and copper) has been determined and compared in 50 samples of red lentils, peas, Borlotti beans, pearl barley, and cereals soup. All the samples cooked with sous-vide showed a significant increase in the content of minerals with the exception of potassium in cereal soup, iron in Borlotti beans, and magnesium in pearl barley. Ash content increased in legumes and in cereal soup cooked with sous-vide method. The higher different ashes concentration between total samples cooked with traditional cooking and with sous-vide was registered in zinc (+862 mg), iron (+314 mg), potassium (+109 mg), and copper (+95 mg). Sous-vide is preferred as it provides products with a higher concentration of metals compared to the ones cooked with traditional cooking.

  13. General Corrosion and Localized Corrosion of the Drip Shield

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua

    2004-09-16

    The repository design includes a drip shield (BSC 2004 [DIRS 168489]) that provides protection for the waste package both as a barrier to seepage water contact and a physical barrier to potential rockfall. The purpose of the process-level models developed in this report is to model dry oxidation, general corrosion, and localized corrosion of the drip shield plate material, which is made of Ti Grade 7. This document is prepared according to ''Technical Work Plan For: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The models developed in this report are used by the waste package degradation analyses for TSPA-LA and serve as a basis to determine the performance of the drip shield. The drip shield may suffer from other forms of failure such as the hydrogen induced cracking (HIC) or stress corrosion cracking (SCC), or both. Stress corrosion cracking of the drip shield material is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]). Hydrogen induced cracking of the drip shield material is discussed in ''Hydrogen Induced Cracking of Drip Shield'' (BSC 2004 [DIRS 169847]).

  14. Corrosion of steel structures in sea-bed sediment

    Indian Academy of Sciences (India)

    Xiutong Wang; Jizhou Duan; Yan Li; Jie Zhang; Shide Ma; Baorong Hou

    2005-04-01

    Seabed sediment (SBS) is a special soil that is covered by seawater. With the developments in marine oil exploitation and engineering, more and more steel structures have been buried in SBS. SBS corrosion has now become a serious problem in marine environment and an important issue in corrosion science. In this paper, approach in the field of SBS corrosion is reviewed. Electrochemical and microbial corrosion factors, corrosion mechanism, measurement of metal corrosion rate, corrosion evaluation and prediction of corrosion are also discussed here.

  15. Alternative Submarine Watch Systems: Recommendation for a New CF Submarine Watch Schedule (Systemes Differents d’Horaire de Garde a Bord des Sous-Marins: Nouvel Horaire Recommande Pour les Sous-Marins des FC)

    Science.gov (United States)

    2010-01-01

    certains horaires peuvent nuire au sommeil et hypothéquer le rendement au travail. L’évaluation des horaires de garde à bord des sous-marins des FC...réalisée en 2007 a révélé des problèmes chroniques de sommeil et des niveaux dangereusement faibles d’efficacité cognitive chez les membres de l’équipage...du sommeil , le groupe de chercheurs a évalué trois horaires de garde différents, soit l’horaire à 1 tour sur trois de huit heures exigeant trois

  16. Les mutations du raffinage européen : contraintes et stratégies The European Refining Industry: Constraints and Strategies

    Directory of Open Access Journals (Sweden)

    Valais M.

    2006-11-01

    Full Text Available Plus que toute autre région dans le monde, l'Europe occidentale a profondément ressenti dans son industrie du raffinage, le contrecoup des crises énergétiques et pétrolières des douze dernières années. A l'issue d'une première phase de rationalisation et de restructuration unique dans son histoire, elle se trouve à nouveau confrontée à des problèmes d'adaptation de son outil aux exigences quantitatives et qualitatives de sa demande de produits finis. Desservant un marché de plus en plus sensible aux concurrences intérieures et extérieures, le raffinage de l'Europe occidentale devra nécessairement effectuer des choix stratégiques, rationaliser et investir afin de faire face aux contraintes du marché des produits, gagner en flexibilité et accroître sa compétitivité. More than in any other region in the world, Western Europe's refining industry has been deeply hurt by the aftershocks of the energy and oil crises in the last twelve years. After an initial phase of unprecedented restructuring, this industry is once again having to face problems of adapting its equipment to the quantitative and qualitative requirements of the demand for refined products. Because it serves a market that is more and more sensitive to internal and external competition, Western European refining must necessarily make strategic choices, it must invest to maintain its competitiveness, i. e. its very survival.

  17. La photosynthèse du mil (Pennisetum glaucum (L. R.Br. en présence de contrainte hydrique et saline

    Directory of Open Access Journals (Sweden)

    Leila Radhouane

    2011-11-01

    Full Text Available La surexploitation et le gaspillage de nos ressources en eau, en particulier dans le domaine agricole, privent d’eau d’autres zones entraînant ainsi la baisse de la production agricole. L’amélioration de l’efficience de l’irrigation – soit l’augmentation de la production pour chaque mètre cube d’eau investi – est un objectif crucial pour l’avenir et doit donc devenir l’une des premières priorités. Que ce soit l’irrigation déficitaire ou l’usage d’eaux saumâtres, l’utilisation de ces eaux peut s’accompagner de transformations morphologiques, physiologiques et biochimiques dont l’intensité dépend de la plante. L’influence de contraintes hydriques et salines a été étudiée sur la photosynthèse de 3 écotypes locaux de mil soumis à 3 doses de sel et à 3 niveaux d’irrigation. Les résultats ont montré que l’efficience photosynthétique du mil est meilleure en présence d’un léger manque d’eau ou en présence d’une salinité modérée et que seule une sécheresse sévère ou un excès d’eau sont contraignants pour la photosynthèse de cette plante. Egalement, la photosynthèse a présenté une variabilité selon les écotypes utilisés.

  18. Report on accelerated corrosion studies.

    Energy Technology Data Exchange (ETDEWEB)

    Mowry, Curtis Dale; Glass, Sarah Jill; Sorensen, Neil Robert

    2011-03-01

    Sandia National Laboratories (SNL) conducted accelerated atmospheric corrosion testing for the U.S. Consumer Product Safety Commission (CPSC) to help further the understanding of the development of corrosion products on conductor materials in household electrical components exposed to environmental conditions representative of homes constructed with problem drywall. The conditions of the accelerated testing were chosen to produce corrosion product growth that would be consistent with long-term exposure to environments containing humidity and parts per billion (ppb) levels of hydrogen sulfide (H{sub 2}S) that are thought to have been the source of corrosion in electrical components from affected homes. This report documents the test set-up, monitoring of electrical performance of powered electrical components during the exposure, and the materials characterization conducted on wires, screws, and contact plates from selected electrical components. No degradation in electrical performance (measured via voltage drop) was measured during the course of the 8-week exposure, which was approximately equivalent to 40 years of exposure in a light industrial environment. Analyses show that corrosion products consisting of various phases of copper sulfide, copper sulfate, and copper oxide are found on exposed surfaces of the conductor materials including wires, screws, and contact plates. The morphology and the thickness of the corrosion products showed a range of character. In some of the copper wires that were observed, corrosion product had flaked or spalled off the surface, exposing fresh metal to the reaction with the contaminant gasses; however, there was no significant change in the wire cross-sectional area.

  19. Detective probe prevents corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-07-01

    A black liquor recovery boiler is the main investment in a pulp mill, accounting for: about a third of the total cost of FIM 3-4 billion. Environmental aspects required that all the harmful chemicals involved in the process have to be kept within a pulp mill, rather than be released outside, and closed water circulation systems have to be introduced. These have led to the enrichment of some process and non-process chemicals causing corrosion problems and process disturbances in the boiler. The recovery boiler receives the liquor after the digestion stage, i.e. when woodchips are cooked to make cellulose, and burns it. During digestion, the wood produces out lignin, mixed with the liquor (consisting of sodium sulphide and hydroxide). The black liquor is burnt at the bottom of the boiler after the organic parts have been fired off. The rest goes into the recovery system and the chemicals are recycled producing energy, saving repurchasing chemicals and protecting the environment from toxic emissions.

  20. Corrosion in Electronic Devices and Sensors to Prevent Corrosion

    Directory of Open Access Journals (Sweden)

    Siddharth Dev

    2014-02-01

    Full Text Available Many types of metal and alloys are used in various electronic devices and components like computers, microchips, printed circuit board (PCB, integrated circuits, transistors, and diodes etc. Such components have variety of applications in the field of medical, aerospace, automotive sectors, telecommunication and defense. These components are exposed to different types of environments. The increased used of electronics has also increased the demand for reliability. The size of electronic equipment is also very significant parameter and it has been decreasing presently at a faster rate. The smaller size of equipment has undetectable failures. Though the corrosion taking place in electronic components is generally of micro level which can not be detected easily but the services of device are seized. The paper deals with the various types of corrosion in electronic components as a case study and an approach towards development of some sensor for corrosion monitoring.

  1. Quantitative measures of corrosion and prevention: application to corrosion in agriculture

    NARCIS (Netherlands)

    Schouten, J.C.; Gellings, P.J.

    1987-01-01

    The corrosion protection factor (c.p.f.) and the corrosion condition (c.c.) are simple instruments for the study and evaluation of the contribution and efficiency of several methods of corrosion prevention and control. The application of c.p.f. and c.c. to corrosion and prevention in agriculture in

  2. Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

    Science.gov (United States)

    Huang, B. S.; Yin, W. F.; Sang, D. H.; Jiang, Z. Y.

    2012-10-01

    The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 °C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr5S8 phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

  3. Quantitative measures of corrosion and prevention: application to corrosion in agriculture

    NARCIS (Netherlands)

    Schouten, J.C.; Gellings, P.J.

    1987-01-01

    The corrosion protection factor (c.p.f.) and the corrosion condition (c.c.) are simple instruments for the study and evaluation of the contribution and efficiency of several methods of corrosion prevention and control. The application of c.p.f. and c.c. to corrosion and prevention in agriculture in

  4. Protection biologique contre ravageurs aériens sur tomate sous abris : compte-rendu d'essai 2005

    OpenAIRE

    Mazollier, Catherine; Lambion, Jérôme; Ranc, Nicolas

    2006-01-01

    En agriculture biologique, les moyens de protection contre les ravageurs aériens sont coûteux et leur efficacité est parfois insuffisante. La pratique des brumisations sous abris réduit les températures et augmente l’hygrométrie, et peut améliorer la protection contre l’acarien Tetranychus urticae, comme l'ont montré les essais du GRAB conduits de 2002 à 2004 sur melon, aubergine et concombre. Cet essai a pour objectif d’étudier l’intérêt de la brumisation et de la lutte biologique contre l'e...

  5. Tumeur sous scapulaire: élastofibrome dorsal bilatéral à propos d'un cas

    Science.gov (United States)

    Dlimi, Meriem; Boukind, Samira; Elatiqi, Oumkeltoum; Elamrani, Driss; Benchamkha, Yassine; Ettalbi, Saloua

    2015-01-01

    L’élastofibrome dorsal est une tumeur bénigne rare des parties molles siégeant typiquement sous la pointe de la scapula. Nous rapportons notre observation; pour préciser les caractéristiques cliniques et paracliniques de ce type de tumeur ainsi que les modalités de prise en charge; cette entité gagnerait à être connue par tout praticien; pour permettre une attitude thérapeutique bien codifiée. PMID:26405479

  6. Corrosion effects on friction factors

    Energy Technology Data Exchange (ETDEWEB)

    Magleby, H.L.; Shaffer, S.J.

    1996-03-01

    This paper presents the results of NRC-sponsored material specimen tests that were performed to determine if corrosion increases the friction factors of sliding surfaces of motor-operated gate valves, which could require higher forces to close and open safety-related valves when subjected to their design basis differential pressures. Friction tests were performed with uncorroded specimens and specimens subjected to accelerated corrosion. Preliminary tests at ambient conditions showed that corrosion increased the friction factors, indicating the need for additional tests duplicating valve operating parameters at hot conditions. The additional tests showed friction factors of corroded specimens were 0.1 to 0.2 higher than for uncorroded specimens, and that the friction factors of the corroded specimens were not very dependent on contact stress or corrosion film thickness. The measured values of friction factors for the three corrosion films tested (simulating three operating times) were in the range of 0.3 to 0.4. The friction factor for even the shortest simulated operating time was essentially the same as the others, indicating that the friction factors appear to reach a plateau and that the plateau is reached quickly.

  7. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  8. Microencapsulation of Corrosion Indicators for Smart Coatings

    Science.gov (United States)

    Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott T.; Calle, Luz M.; Hanna,Joshua S.; Rawlins, James W.

    2011-01-01

    A multifunctional smart coating for the autonomous detection, indication, and control of corrosion is been developed based on microencapsulation technology. This paper summarizes the development, optimization, and testing of microcapsules specifically designed for early detection and indication of corrosion when incorporated into a smart coating. Results from experiments designed to test the ability of the microcapsules to detect and indicate corrosion, when blended into several paint systems, show that these experimental coatings generate a color change, indicative of spot specific corrosion events, that can be observed with the naked eye within hours rather than the hundreds of hours or months typical of the standard accelerated corrosion test protocols.. Key words: smart coating, corrosion detection, microencapsulation, microcapsule, pH-sensitive microcapsule, corrosion indicator, corrosion sensing paint

  9. Method For Testing Properties Of Corrosive Lubricants

    Science.gov (United States)

    Ohi, James; De La Cruz, Jose L.; Lacey, Paul I.

    2006-01-03

    A method of testing corrosive lubricating media using a wear testing apparatus without a mechanical seal. The wear testing apparatus and methods are effective for testing volatile corrosive lubricating media under pressure and at high temperatures.

  10. Smart Coatings for Launch Site Corrosion Protection

    Science.gov (United States)

    Calle, Luz M.

    2014-01-01

    Smart, environmentally friendly paint system for early corrosion detection, mitigation, and healing that will enable supportability in KSC launch facilities and ground systems through their operational life cycles. KSC's Corrosion Technology Laboratory is developing a smart, self-healing coating that can detect and repair corrosion at an early stage. This coating is being developed using microcapsules specifically designed to deliver the contents of their core when corrosion starts.

  11. Multicomponent Oxide Systems for Corrosion Protection.

    Science.gov (United States)

    1980-11-15

    and Si(OEt) 4 are somewhat lpss corrosive to aluminum than is SiCI 4 alone, although some pitting occurs for slow hydrolysis after coating by solutions...humidity (x) 86 A𔃻 determinants of corrosion resistance. The magnesium-silicon- aluminum alloy AA 6061 is generally considered to have good corrosion ... 6061 ), the corrosion resistance exceeded that of the chromate coatings. The feasibilityof the basic approach taken here has been validated. It

  12. Surface modification for corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.

    1993-06-01

    The raw gas environments that arise from coal gasification have chemical compositions that are low in pO{sub 2} and moderate-to-high in pS{sub 2}. Metallic materials for service in such an environment undergo predominantly sulfidation attack at temperatures of 400 to 700{degree}C. Modification of alloy compositions in bulk can alter the scaling processes and lead to improvements in corrosion resistance, but the benefits can only be attained at temperatures much higher than the service temperatures of the components. Modification of surfaces of structural components by several of the coating techniques examined in this study showed substantial benefit in corrosion resistance when tested in simulated coal gasification environments. The paper presents several examples of surface modification and their corrosion performance.

  13. Electrochemical corrosion of metallic biomaterials.

    Science.gov (United States)

    Pourbaix, M

    1984-05-01

    Methods of electrochemical thermodynamics (electrode potential-pH equilibrium diagrams) and electrochemical kinetics (polarization curves) may help to understand and predict the corrosion behaviour of metals and alloys in the presence of body fluids. A short review of the literature is given concerning some applications of such methods, both in vitro and in vivo, relating to surgical implants (stainless steels, chromium-cobalt-molybdenum alloys, titanium and titanium alloys) and to dental alloys (silver-tin-copper amalgams, silver-base and gold-base casting alloys, nickel-base casting alloys). Attention is drawn to the necessity of more basic research on crevice- and fretting-corrosion of surgical implant materials and dental alloys, and to the toxicity of corrosion products. A perfect understanding of the exact significance of electrode-potentials is essential for the success of such a task.

  14. Strain Measurement Technology for Corrosion Fatigue Specimen

    Institute of Scientific and Technical Information of China (English)

    ZHONG; Wei-hua; NING; Guang-sheng; ZHANG; Chang-yi; TONG; Zhen-feng; YANG; Wen

    2015-01-01

    Main pipeline is the key component of nuclear power plants(NPPs).Under the first loop water and low-cyclic load condition,the main pipeline may be induced to corrosion fatigue failure.Thus,it’s necessary to test and get the corrosion fatigue property of main pipeline material.During the corrosion fatigue test,the strain

  15. 7 CFR 2902.44 - Corrosion preventatives.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Corrosion preventatives. 2902.44 Section 2902.44... Items § 2902.44 Corrosion preventatives. (a) Definition. Products designed to prevent the deterioration (corrosion) of metals. (b) Minimum biobased content. The preferred procurement product must have a...

  16. 49 CFR 193.2625 - Corrosion protection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Corrosion protection. 193.2625 Section 193.2625...: FEDERAL SAFETY STANDARDS Maintenance § 193.2625 Corrosion protection. (a) Each operator shall determine which metallic components could, unless corrosion is controlled, have their integrity or...

  17. Corrosion-Induced Concrete Cracking Model Considering Corrosion-Filled Paste

    OpenAIRE

    Dong, Jianfeng; Zhao, Yuxi; Wu, Yingyao; Jin, Weiliang

    2016-01-01

    A TCP–TCL model is established to describe the relationship between the thickness of the corrosion-filled paste (CP) and that of the corrosion layer (CL). This model can describe the phenomenon that the corrosion filling in the concrete pores and accumulating at the steel/concrete interface occur synchronously. Based on the TCP–TCL model, a corrosion-induced concrete cracking model, which can quantitatively consider corrosion-filled paste at concrete/steel interface, is proposed. Combined wit...

  18. Corrosion-Inhibitor Efficiency Control: Comparison by Means of Different Portable Corrosion Rate Meters

    OpenAIRE

    Martinez Sierra, Isabel; Andrade Perdrix, Maria del Carmen; Rebolledo Ramos, Nuria; Luo, L; De Schutter, G

    2010-01-01

    Corrosion-inhibiting substances have been applied to suppress corrosion mainly on bare steel, but when corrosion is progressing, suppression can be achieved if anodic and cathodic reactions are avoided, which is not an easy objective, particularly if the bare metal is surrounded by concrete. In the present article, several corrosion inhibitors are studied to identify their inhibition efficiency in concrete. The percentage of reduction of the corrosion rate without and with inhibitor is named ...

  19. Electrochemical Measurement of Atmospheric Corrosion

    Science.gov (United States)

    DeArmond, Anna H.; Davis, Dennis D.; Beeson, Harold D.

    1999-01-01

    Corrosion of Shuttle thruster components in atmospheres containing high concentrations of nitrogen tetroxide (NTO) and water is an important issue in ground operations of bipropellant systems in humid locations. Measurements of the corrosivities of NTO-containing atmospheres and the responses of different materials to these atmospheres have been accomplished using an electrochemical sensor. The sensor is composed of alternating aluminum/titanium strips separated by thin insulating layers. Under high humidity conditions a thin film of water covers the surface of the sensor. Added NTO vapor reacts with the water film to form a conductive medium and establishes a galvanic cell. The current from this cell can be integrated with respect to time and related to the corrosion activity. The surface layer formed from humid air/NTO reacts in the same way as an aqueous solution of nitric acid. Nitric acid is generally considered an important agent in NTO corrosion situations. The aluminum/titanium sensor is unresponsive to dry air, responds slightly to humid air (> 75% RH), and responds strongly to the combination of humid air and NTO. The sensor response is a power function (n = 2) of the NTO concentration. The sensor does not respond to NTO in dry air. The response of other materials in this type of sensor is related to position of the material in a galvanic series in aqueous nitric acid. The concept and operation of this electrochemical corrosion measurement is being applied to other corrosive atmospheric contaminants such as hydrogen chloride, hydrogen fluoride, sulfur dioxide, and acidic aerosols.

  20. Corrosion performance of structural alloys.

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.

    1999-07-15

    Component reliability and long-term trouble-free performance of structural materials are essential in power-generating and gasification processes that utilize coal as a feedstock. During combustion and conversion of coal, the environments encompass a wide range of oxygen partial pressures, from excess-air conditions in conventional boilers to air-deficient conditions in 10W-NO{sub x} and gasification systems. Apart from the environmental aspects of the effluent from coal combustion and conversion, one concern from the systems standpoint is the aggressiveness of the gaseous/deposit environment toward structural components such as waterwall tubes, steam superheaters, syngas coolers, and hot-gas filters. The corrosion tests in the program described in this paper address the individual and combined effects of oxygen, sulfur, and chlorine on the corrosion response of several ASME-coded and noncoded structural alloys that were exposed to air-deficient and excess-air environments typical of coal-combustion and gasification processes. Data in this paper address the effects of preoxidation on the subsequent corrosion performance of structural materials such as 9Cr-1Mo ferritic steel, Type 347 austenitic stainless steel, Alloys 800, 825, 625, 214, Hastelloy X, and iron aluminide when exposed at 650 C to various mixed-gas environments with and without HCI. Results are presented for scaling kinetics, microstructural characteristics of corrosion products, detailed evaluations of near-surface regions of the exposed specimens, gains in our mechanistic understanding of the roles of S and Cl in the corrosion process, and the effect of preoxidation on subsequent corrosion.

  1. Cyclone reburning retrofit: Corrosion evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Sarv, H.; Paul, L.D. (Babcock and Wilcox Co., New Orleans, LA (USA))

    1991-01-01

    Reburning is an emerging NO{sub x} reducing technology which offers cyclone boiler owners a promising alternative to the more expensive flue gas cleanup techniques. Pilot-scale test results have shown that the corrosive H{sub 2}S gas can evolve during reburn. This can pose a potential problem and concern in retrofits burning high-sulfur Illinois coals. This research program is intended to assess tube corrosion under simulated reburning conditions (temperature, stoichiometry, and H{sub 2}S concentration). Performance of existing carbon steel as well as other alloys will be tested and compared. 1 fig.

  2. Cyclone reburning retrofit: Corrosion evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Farzan, H.; Paul, L.D. (Babcock and Wilcox Co., New Orleans, LA (USA))

    1990-01-01

    Reburning is an emerging NO{sub x} reducing technology which offers cyclone boiler owners a promising alternative to the more expensive flue gas cleanup techniques. Pilot-scale test results have shown that the corrosive H{sub 2}S gas can evolve during reburn. This can pose a potential problem and concern in retrofits burning high-sulfur Illinois coals. This research program is intended to assess tube corrosion under simulated reburning conditions (temperature, stoichiometry, and H{sub 2}S concentration). Performance of existing carbon steel as well as other alloys will be tested and compared. 1 fig.

  3. Corrosion Reliability of Electronic Systems

    DEFF Research Database (Denmark)

    Ambat, Rajan; Jensen, Stine G.; Møller, Per

    2008-01-01

    Inherently two factors namely multi-material usage and potential bias makes electronic devices susceptible to corrosion if exposed to humid conditions. The problem is compounded today due to miniaturization and contamination effects. The reduction in size of the components and close spacing...... on a Printed Circuit Board (PCB) for high density packing has greatly increased the risk of corrosion under humid conditions. An important issue is the failures due to electrolytic metal migration. This paper describes an investigation of the electrolytic migration of Sn-Pb solder lines on PCBs in humid...

  4. Microbial Influenced Corrosion (MIC) Study

    Science.gov (United States)

    2012-05-23

    low lying areas breaks down protective coating system and causes structural corrosion , • Water and organic/inorganic nutrients BUSINESS SENSITIVE...Chemical disinfection (T.O 1-1-8 and T.O 1-1-691) • Biocidal rinses and coatings • Biocidal Corrosion Preventative Compounds or CPCs BUSINESS...Type: H    Proprietary  Coating  w/ Silver  Inhibitor   Non‐Chrome Treatment + Mg‐Rich  Primer  Coupon Type: I    Prekote® (Pantheon Chemical) N/A

  5. High temperature corrosion in gasifiers

    Directory of Open Access Journals (Sweden)

    Bakker Wate

    2004-01-01

    Full Text Available Several commercial scale coal gasification combined cycle power plants have been built and successfully operated during the last 5-10 years. Supporting research on materials of construction has been carried out for the last 20 years by EPRI and others. Emphasis was on metallic alloys for heat exchangers and other components in contact with hot corrosive gases at high temperatures. In this paper major high temperature corrosion mechanisms, materials performance in presently operating gasifiers and future research needs will be discussed.

  6. Corrosive effects of hvdc transmission

    Energy Technology Data Exchange (ETDEWEB)

    Cornwell, F.E.; Backstrom, T.E.

    1966-02-01

    Field tests using ac transmission lines for introduction of direct current into the earth at widely separated points are described. One test circuit was between a Tracy pumping plant and a Shasta power plant in California, and two others were in the Hoover power plant area. Evaluation of the effects of such ground currents on corrosion of buried metalwork was a primary aim of the tests. Potential gradients, pipe-to-soil potentials, and soil resistivities are discussed in detail. Estimates are made of the distances from ehv dc terminal installations within which corrosion prevention procedures may become necessary.

  7. Coatings for improved corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.

    1992-05-01

    Several coating approaches are being developed to resist attack in coal-fired environments and thereby minimize corrosion of underlying substrate alloys and extend the time for onset of breakaway corrosion. In general, coating systems can be classified as either diffusion or overlay type, which are distinguished principally by the method of deposition and the structure of the resultant coating-substrate bond. The coating techniques examined are pack cementation, electrospark deposition, physical and chemical vapor deposition, plasma spray, and ion implantation. In addition, ceramic coatings are used in some applications.

  8. Faulting mechanisms and stress regime at the European HDR site of Soultz-sous-Forets, France

    Energy Technology Data Exchange (ETDEWEB)

    Cuenot, Nicolas; Charlety, Jean; Haessler, Henri [Institut de Physique du Globe de Strasbourg, Ecole et Observatoire des Sciences de la Terre (IPGS-EOST), 5 rue Rene Descartes, 67084 Strasbourg Cedex (France); Dorbath, Louis [Institut de Physique du Globe de Strasbourg, Ecole et Observatoire des Sciences de la Terre (IPGS-EOST), 5 rue Rene Descartes, 67084 Strasbourg Cedex (France); Institut de Recherche pour le Developpement, Laboratoire des Mecanismes et Transferts en Geologie (IRD, LMTG), 14 Avenue Edouard Belin, 31400 Toulouse (France)

    2006-10-15

    The state of stress and its implications for shear on fault planes during fluid injection are crucial issues for the HDR (Hot Dry Rock) or EGS (Enhanced or Engineered Geothermal System) concept. This is especially true for hydraulic stimulation experiments, aimed at enhancing the connectivity of a borehole to the natural fracture network, since they tend to induce the shearing of fractures, which is controlled by the local stress regime. During the 2000 and 2003 stimulation tests at Soultz-sous-Forets, France, about 10,000 microearthquakes were located with a surface seismological network. Hundreds of double-couple (DC) focal mechanisms were automatically determined from first-motion polarities using the FPFIT program [Reasenberg, P.A., Oppenheimer, D., 1985. FPFIT, FPPLOT and FPPAGE: Fortran computer programs for calculating and displaying earthquake fault-plane solutions. US Geological Survey Open-File Report 85-739, 25 pp.]. The majority of these mechanisms indicate normal-faulting movement with a more or less pronounced strike-slip component. Some quasi-pure strike-slip events also occurred, especially in the deeper part of the stimulated rock volume, at more than 5 km depth. Although we found a double-couple solution for all events, we tried to observe and quantify the proportion of the non-double-couple (NDC) component in the seismic moment tensor for several microseisms from the 2003 data. The study shows that the NDC is higher for the events in the vicinity of the injection well than for the events far from the well. We used the method of Rivera and Cisternas [Rivera, L., Cisternas, A., 1990. Stress tensor and fault-plane solutions for a population of earthquakes. Bull. Seismol. Soc. Am. 80, 600-614.] to perform the inversion of the deviatoric part of the stress tensor from P-wave polarities. This method was applied to different datasets from the 2000 test, taken from the shallower and deeper parts of the stimulated region. The results show a stable

  9. Influence of Sous Vide and water immersion processing on polyacetylene content and instrumental color of parsnip (Pastinaca sativa) disks.

    Science.gov (United States)

    Rawson, Ashish; Koidis, Anastasios; Rai, Dilip K; Tuohy, Maria; Brunton, Nigel

    2010-07-14

    The effect of blanching (95 +/- 3 degrees C) followed by sous vide (SV) processing (90 degrees C for 10 min) on levels of two polyacetylenes in parsnip disks immediately after processing and during chill storage was studied and compared with the effect of water immersion (WI) processing (70 degrees C for 2 min.). Blanching had the greatest influence on the retention of polyacetylenes in sous vide processed parsnip disks resulting in significant decreases of 24.5 and 24% of falcarinol (1) and falcarindiol (2) respectively (p 0.05). 1 levels in WI processed samples were significantly higher than in SV samples (p

  10. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, L. M.; Hintze, P. E.; Li, W.; Buhrow, J. W.; Jolley, S. T.

    2011-01-01

    This slide presentation reviews the effects of corrosion on various structures at the Kennedy Space Center, and the work to discover a corrosion control coating that will be autonomous and will indicate corrosion at an early point in the process. Kennedy Space Center has many environmental conditions that are corrosive: ocean salt spray, heat, humidity, sunlight and acidic exhaust from the Solid Rocket Boosters (SRBs). Presented is a chart which shows the corrosion rates of carbon steel at various locations. KSC has the highest corrosion rates with 42.0 mils/yr, leading the next highest Galeta Point Beach, in the Panama Canal Zone with 27 mils/yr corrosion. A chart shows the changes in corrosion rate with the distance from the ocean. The three types of corrosion protective coatings are described: barrier (passive), Barrier plus active corrosion inhibiting components, and smart. A smart coating will detect and respond actively to changes in its environment in a functional and predictable manner and is capable of adapting its properties dynamically. The smart coating uses microcapsules, particles or liquid drops coated in polymers, that can detect and control the corrosion caused by the environment. The mechanism for a pH sensitive microcapsule and the hydrophobic core microcapsule are demonstrated and the chemistry is reviewed. When corrosion begins, the microcapsule will release the contents of the core (indicator, inhibitor, and self healing agent) in close proximity to the corrosion. The response to a pH increase is demonstrated by a series of pictures that show the breakdown of the microcapsule and the contents release. An example of bolt corrosion is used, as an example of corrosion in places that are difficult to ascertain. A comparison of various coating systems is shown.

  11. Assessing Level and Effectiveness of Corrosion Education in the UAE

    Directory of Open Access Journals (Sweden)

    Hwee Ling Lim

    2012-01-01

    Full Text Available The consequences of corrosion can be minimized by an engineering workforce well trained in corrosion fundamentals and management. Since the United Arab Emirates incurs the second highest cost of corrosion after Saudi Arabia, this paper examined the quality of corrosion education in the UAE. Surveys with academia and industry respondents showed that dedicated corrosion courses and engineering courses that integrated corrosion into the curricula were available in UAE universities, but graduates had insufficient knowledge of corrosion engineering and superficial understanding of corrosion in real-life design contexts. The effectiveness of corrosion education is determined by both competence in corrosion knowledge/skills and availability of resources (faculty and research. Though most departments would not hire new corrosion-specialist faculty, department research efforts and industry partnerships in corrosion research were present. The paper concluded with recommendations for improving knowledge and skills of future engineers in corrosion and enhancing corrosion instruction to better meet industry needs.

  12. General Corrosion and Localized Corrosion of Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; McCright, R.D.

    2000-01-28

    Alloy 22 is an extremely Corrosion Resistant Material, with a very stable passive film. Based upon exposures in the LTCTF, the GC rates of Alloy 22 are typically below the level of detection, with four outliers having reported rates up to 0.75 #mu#m per year. In any event, over the 10,000 year life of the repository, GC of the Alloy 22 (assumed to be 2 cm thick) should not be life limiting. Because measured corrosion potentials are far below threshold potentials, localized breakdown of the passive film is unlikely under plausible conditions, even in SSW at 120 deg C. The pH in ambient-temperature crevices formed from Alloy 22 have been determined experimentally, with only modest lowering of the crevice pH observed under plausible conditions. Extreme lowering of the crevice pH was only observed under situations where the applied potential at the crevice mouth was sufficient to result in catastrophic breakdown of the passive film above the threshold potential in non-buffered conditions not characteristic of the Yucca Mountain environment. In cases where naturally ocurring buffers are present in the crevice solution, little or no lowering of the pH was observed, even with significant applied potential. With exposures of twelve months, no evidence of crevice corrosion has been observed in SDW, SCW and SAW at temperatures up to 90 deg C. An abstracted model has been presented, with parameters determined experimentally, that should enable performance assessment to account for the general and localized corrosion of this material. A feature of this model is the use of the materials specification to limit the range of corrosion and threshold potentials, thereby making sure that substandard materials prone to localized attack are avoided. Model validation will be covered in part by a companion SMR on abstraction of this model.

  13. Atmospheric corrosion sensor based on strain measurement

    Science.gov (United States)

    Kasai, Naoya; Hiroki, Masatoshi; Yamada, Toshirou; Kihira, Hiroshi; Matsuoka, Kazumi; Kuriyama, Yukihisa; Okazaki, Shinji

    2017-01-01

    In this paper, an in situ atmospheric corrosion sensor based on strain measurement is discussed. The theoretical background for measuring the reduction in thickness of low carbon steel is also presented. Based on the theoretical considerations, a test piece and apparatus for an atmospheric corrosion sensor were designed. Furthermore, in a dry–wet cyclic accelerated exposure experiment, the measured strain indicated thinning of the test piece, although the corrosion product generated on the surface of the test piece affected the results. The atmospheric corrosion sensor would be effective for evaluating atmospheric corrosion of many types of infrastructure.

  14. Nodular Corrosion Characteristics of Zirconium Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Gil; Jeong, Y. H.; Park, S. Y.; Lee, D. J

    2003-01-15

    This study was reported the effect of the nodular corrosion on the nuclear reactor environmental along with metallurgical influence, also suggested experimental scheme related to evaluate nodular corrosion characteristics of Zr-1 Nb alloy. Remedial strategies against the nodular corrosion should firstly develop plan to assess the effect of the water quality condition (Oxygen, Hydrogen) as well as the boiling on the nodular corrosion, secondarily establish plan to control heat treatment process to keep a good resistance on nodular corrosion in Zr-1Nb alloy as former western reactor did.

  15. Analyses of containment structures with corrosion damage

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, J.L.

    1996-12-31

    Corrosion damage to a nuclear power plant containment structure can degrade the pressure capacity of the vessel. For the low-carbon, low- strength steels used in containments, the effect of corrosion on material properties is discussed. Strain-to-failure tests, in uniaxial tension, have been performed on corroded material samples. Results were used to select strain-based failure criteria for corroded steel. Using the ABAQUS finite element analysis code, the capacity of a typical PWR Ice Condenser containment with corrosion damage has been studied. Multiple analyses were performed with the locations of the corrosion the containment, and the amount of corrosion varied in each analysis.

  16. Capacités exécutives pour la planification de séquences d'actions motrices réalisées sous contraintes spatiales et temporelles : une tâche de tapping visuo-spatial

    OpenAIRE

    Dione, Mariama

    2013-01-01

    In a constant changing environment, executive abilities allow us to organize sensory information of multiple sources and to adapt to diverse stuations while at the same time inhibiting inappropriate behaviors. research on the executive functions (EFS) have historical roots on neuropsychology, with the description of frontal patients that were showing disruptions in organizing their daily behaviors independently of any impairment in memory, language or general intelligence. A wide range of neu...

  17. From asymmetric window to spectral constrained factor analysis: A review of the methods of Compton scatter correction in radioisotope imaging. De la fenetre asymetrique a l'analyse factorielle sous contrainte spectrale: une revue des methodes de correction de la diffusion Compton en imagerie isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Mas, J.; Hannequin, P.; Ben Younes, R.; Pousse, A.; Bidet, R. (Centre Hospitalier Universitaire Jean Minjoz, 25 - Besancon (FR))

    1990-01-01

    The quality of nuclear images is degraded by the poor spatial resolution of the gamma-camera, the attenuation, the statistical noise and the Compton scattered photons included within the pulseheight window centred on the radionuclide peak. A +- 10% window is needed if all the photopeak photons have to be detected, because of the low gamma-camera energy resolution, thus including a lot of scattered photons in this acquisition window. This last problem has received little attention in the literature, whereas attenuation and spatial resolution have been more extensively studied. Nevertheless, the use of refined techniques to achieve more accurate reconstruction of the true radioactivity distribution implies to address the problem of Compton scatter. We review in this paper all the methods of Compton scatter correction suggested during the eighties, presenting the main results, advantages and limits of each. 49 refs.

  18. Power electronics and tomorrow's vehicles; optimisation of a 42 V - 14 V converter constrained by jamming, output, electromagnetic and thermal compatibility; L'electronique de puissance et le vehicule de demain; optimisation d'un convertisseur 42 V-14 V sous des contraintes d'encombrement, de rendement, de compatibilite electromagnetique et thermiques

    Energy Technology Data Exchange (ETDEWEB)

    Larouci, Ch.; Didier, J.P.; Selvez, M.; Prado, S.; Couturier, R.; Ohayone, E.; Retailleaux, X. [ESTACA, Lab. Commande et systemes, 92 - Levallois Perret (France)

    2005-01-01

    The article proposes an optimisation process of the jamming of a 42 V-14 V converter constrained by output, electromagnetic compatibility (EMC) and thermal compatibility. This converter is dedicated to the 42 V on-board to manage exchanges of power between two batteries with different voltages. In this context, we are going to develop analytical modules to take into account the chief aspects linked to the converter's design. The aim is to determine the best compromise between the volume of the structure, its output, respect for EMC standards and thermal constraints. (authors)

  19. Use of HMPAO-{sup 99m}Tc in radio-labelling endothelial cells: application to the study of the behaviour of endothelialized vascular prostheses under shearing constraint; Utilisation de HMPAO-{sup 99m}Tc pour le radio-marquage de cellules endotheliales: application pour etudier le comportement de protheses vasculaires endothelialisees sous contraintes de cisaillement

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Ph.; Bareille, R.; Brouillaud, B.; Barthe, N.; Rouais, F.; Bordenave, L. [Laboratoire de Biophisique, CHU-Bordeaux, 33076 Bordeaux (France)

    1997-12-31

    Insemination of the low-caliber vascular prostheses at the level of their endo-luminal surfaces by a monolayer of endothelial cells (EC) prior to their implantation diminishes their thrombogen character and increases their long-term expectation of permeability in humans. The aptitude of EC of remaining adherent to their support when exposed to the constraints of circulatory flux must be studied in vitro and all the authors quantify these adherence by the measurement of the loss of gamma activity of the vascular prosthesis after radiolabelling of EC by {sup 111}In oxinate. In this work EC of human origin, adherent to the culture surfaces were radiolabelled by HMPAO-{sup 99m}Tc and optimal conditions of the labelling were determined: the effect of increasing concentrations of HMPAO and increasing activities of HMPAO-{sup 99m}Tc on the viability and metabolic activity of EC; the influence of the temperature and of the time of touching on the labelling yield. Subsequently, this conditions were applied to EC having cultivated a innovative vascular prosthesis. Surface micro-auto-radiographies were realized. The best compromise was obtained with 10 MBq/10{sup 6} EC (40 {mu}g of HMPAO/10{sup 6} EC) corresponding to a labelling yield of 13.7 {+-} 0.7 after 3 hours of contact at 37 deg. C. The micro-auto-radiographies allow visualization of the intracellular radioactivity distribution. The study of adherence of EC to the vascular prosthesis, under shearing constraints, by means of a radiotracer provides numerous advantages vs current utilisation of {sup 111}In oxinate

  20. Stress, microstructure and evolution under ion irradiation in thin films grown by ion beam sputtering: modelling and application to interfacial effects in metallic multilayers; Contraintes, microstructure et sollicitation sous irradiation aux ions de films minces elabores par pulverisation ionique: modelisation et application a l'etude des effets interfaciaux dans des multicouches metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Debelle, A

    2006-09-15

    We have investigated the formation of the interfacial chemical mixing in Mo/Ni multilayers, and particularly the influence of ballistic effects during the growth. For this purpose, hetero-epitaxial b.c.c./f.c.c. Mo(110)/Ni(111) multilayers were grown by two deposition methods: thermal evaporation and direct ion beam sputtering. As a preliminary, an accurate description of the stress state in pure sputtered Mo thin films was required. Microstructural and stress state analyses were essentially carried out by X-ray diffraction, and ion irradiation was used as a powerful tool to control the stress level. We showed that thermal evaporated thin films exhibit a weak tensile growth stress ({approx} 0.6 GPa) that can be accounted for by the grain boundary relaxation model, whereas sputtered thin films develop large compressive growth stress (- 2 to - 4 GPa). This latter results from the bombardment of the growing film by the energetic particles involved during the sputtering process (atomic peening phenomenon), which induces the formation of defects in the layers, generating volume distortions. We thus developed a stress model that includes a hydrostatic stress component to account for these volume strains. This model allowed us to determine the 'unstressed and free of defects lattice parameter' a{sub 0}, solely linked to chemical effects. For epitaxial Mo layers, it was possible to separate coherency stress from growth stress due to their distinct kinetic evolution during ion irradiation. Therefore, the stress analysis enabled us to determine the a{sub 0} values in Mo sub-layers of Mo/Ni superlattices. A tendency to the formation of an interfacial alloy is observed independently of the growth conditions, which suggests that thermodynamic forces favour the exchange mechanism. However, the extent of the intermixing effect is clearly enhanced by ballistic effects. (author)

  1. Experimental study of chemical-mechanical coupling during percolation of reactive fluid through rocks under stress, in the context of the CO{sub 2} geological sequestration; Etude experimentale du couplage chimie-mecanique lors de la percolation d'un fluide reactif dans des roches sous contrainte, dans le contexte de la sequestration geologique du CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, Y

    2006-10-15

    CO{sub 2} injection into geological repositories will induce chemical and mechanical instabilities. The study of these instabilities is based on experimental deformation of natural rock samples under stress, in the presence of fluids containing, or not, dissolved CO{sub 2}. Triaxial cells used for the experiments permitted an independent control and measurement of stress, temperature, fluid pressure and composition. Vertical strains were measured during several months, with a resolution of 1.10{sup -12} s{sup -1} on the strain rate. Simultaneously, fluids were analysed in order to quantify fluid-rock interactions. For limestone samples, percolation of CO{sub 2}-rich fluids increases strain rate by a factor 1.7 up to 5; on the other hand, sandstone deformation remained almost the same. Increase in strain rate with limestone samples was explained by injected water acidification by the CO{sub 2} which increases rock solubility and reaction kinetics. On the opposite, small effect of CO{sub 2} on quartz explains the absence of deformation. X-ray observations confirmed the importance of rock composition and structure on the porosity evolution. Numerical simulations of rock elastic properties showed increasing shear stress into the sample. Measured deformation showed an evolution of reservoir rocks mechanical properties. It was interpreted as the consequence of pressure solution mechanisms both at grains contacts and on grain free surfaces. (author)

  2. Corrosion of Metal-Matrix Composites with Aluminium Alloy Substrate

    Directory of Open Access Journals (Sweden)

    B. Bobic

    2010-03-01

    Full Text Available The corrosion behaviour of MMCs with aluminium alloy matrix was presented. The corrosion characteristics of boron-, graphite-, silicon carbide-, alumina- and mica- reinforced aluminium MMCs were reviewed. The reinforcing phase influence on MMCs corrosion rate as well as on various corrosion forms (galvanic, pitting, stress corrosion cracking, corrosion fatique, tribocorrosion was discussed. Some corrosion protection methods of aluminium based MMCs were described

  3. The dual role of microbes in corrosion.

    Science.gov (United States)

    Kip, Nardy; van Veen, Johannes A

    2015-03-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion.

  4. The dual role of microbes in corrosion

    Science.gov (United States)

    Kip, Nardy; van Veen, Johannes A

    2015-01-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion. PMID:25259571

  5. Corrosion resistant metallic bipolar plate

    Science.gov (United States)

    Brady, Michael P.; Schneibel, Joachim H.; Pint, Bruce A.; Maziasz, Philip J.

    2007-05-01

    A corrosion resistant, electrically conductive component such as a bipolar plate for a PEM fuel cell includes 20 55% Cr, balance base metal such as Ni, Fe, or Co, the component having thereon a substantially external, continuous layer of chromium nitride.

  6. CORROSION INHIBITOR FOR CARBON STEELS

    African Journals Online (AJOL)

    corrosion inhibitor for carbon steel in 3% ac]neon.s' NaCl solution (pH 6) ... compared to stainless steels (Buchweishaija & Hagen 1997). Organic compounds are ... resistant dust for break and clutch linings, wood binders and mould (Gedam.

  7. Encapsulated Multifunction Corrosion Inhibitive Primer.

    Science.gov (United States)

    1983-11-01

    Tec #19 (alkaline detergent), scrubbed vigorously with cheese cloth, then perform R.I.A. drop test for cleanliness (ASTM 7.1.6.22) (Turco Air Tec...Systems, DOE/NASA TM-78180 (1978). 39. Gouda , V.K. and Shater, M.A., Corrosion Sci. 15 199 (1975). 40. Controlled release, Pesticide Symposium 41

  8. Corrosion inhibition for distillation apparatus

    Science.gov (United States)

    Baumert, Kenneth L.; Sagues, Alberto A.; Davis, Burtron H.; Schweighardt, Frank K.

    1985-01-01

    Tower material corrosion in an atmospheric or sub-atmospheric distillation tower in a coal liquefaction process is reduced or eliminated by subjecting chloride-containing tray contents to an appropriate ion-exchange resin to remove chloride from such tray contents materials.

  9. CORROSION RESISTANT JACKETED METAL BODY

    Science.gov (United States)

    Brugmann, E.W.

    1958-08-26

    Reactor faul elements of the elongated cylindrical type which are jacketed in a corrosion resistant material are described. Each feel element is comprised of a plurality of jacketed cylinders of fissionable material in end to end abutting relationship, the jackets being welded together at their adjoining ends to retain the individual segments together and seat the interior of the jackets.

  10. Evolutionary Computation Techniques for Predicting Atmospheric Corrosion

    Directory of Open Access Journals (Sweden)

    Amine Marref

    2013-01-01

    Full Text Available Corrosion occurs in many engineering structures such as bridges, pipelines, and refineries and leads to the destruction of materials in a gradual manner and thus shortening their lifespan. It is therefore crucial to assess the structural integrity of engineering structures which are approaching or exceeding their designed lifespan in order to ensure their correct functioning, for example, carrying ability and safety. An understanding of corrosion and an ability to predict corrosion rate of a material in a particular environment plays a vital role in evaluating the residual life of the material. In this paper we investigate the use of genetic programming and genetic algorithms in the derivation of corrosion-rate expressions for steel and zinc. Genetic programming is used to automatically evolve corrosion-rate expressions while a genetic algorithm is used to evolve the parameters of an already engineered corrosion-rate expression. We show that both evolutionary techniques yield corrosion-rate expressions that have good accuracy.

  11. Corrosion Rate Monitoring in District Heating Systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Andersen, A.

    2005-01-01

    Quality control in district heating systems to keep uniform corrosion rates low and localized corrosion minimal is based on water quality control. Side-stream units equipped with carbon steel probes for online monitoring were mounted in district heating plants to investigate which techniques would...... be applicable, and if on-line monitoring could improve the quality control. Water quality monitoring was applied as well as corrosion rate monitoring with linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), electrical resistance (ER) technique, mass loss and a crevice corrosion...... cell for localized corrosion risk estimation. Important variations in corrosion rate due to changes in make-up water quality were detected with the continuous monitoring provided by ER and crevice cell, while LPR gave unreliable corrosion rates. The acquisition time of two-three days for EIS...

  12. Corrosion Rate Monitoring in District Heating Systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Andersen, A.

    2005-01-01

    Quality control in district heating systems to keep uniform corrosion rates low and localized corrosion minimal is based on water quality control. Side-stream units equipped with carbon steel probes for online monitoring were mounted in district heating plants to investigate which techniques would...... be applicable, and if on-line monitoring could improve the quality control. Water quality monitoring was applied as well as corrosion rate monitoring with linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), electrical resistance (ER) technique, mass loss and a crevice corrosion...... cell for localized corrosion risk estimation. Important variations in corrosion rate due to changes in make-up water quality were detected with the continuous monitoring provided by ER and crevice cell, while LPR gave unreliable corrosion rates. The acquisition time of two-three days for EIS...

  13. Effect of corrosion on flexural bond strength

    Directory of Open Access Journals (Sweden)

    Akshatha Shetty

    2014-09-01

    Full Text Available Corrosion is one of the main causes affecting durability of structures. Corrosion effects on structures cannot be ignored and replaced. To understand the performance of structures there is a need to study the rate at which different corrosion levels occur. Hence the present investigation has been taken up to study the behaviour of NBS (National Bureau of Standard beam specimens made up of Ordinary Portland Cement (OPC and Portland Pozzolona Cement (PPC concrete matrix were subjected to accelerated corrosion for different corrosion levels of 2.5 % to 10 % at 2.5 % interval. Results are compared with those for control beam specimen. It is observed that bond stress value decreases with the increase in corrosion levels. Also corrosion leads to the decline of load carrying capacity.

  14. High Temperature Corrosion on Biodust Firing

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi

    The high content of alkali metals and chlorine in biomass gives rise to fouling/slagging and corrosion of heat exchange components, such as superheaters, in biomass fired power plants. Increasing the lifetime of these components, and in addition, preventing unwarranted plant shutdowns due...... to their failure, requires understanding of the complex corrosion mechanisms, as well as development of materials that are resistant to corrosion under biomass firing conditions, thereby motivating the current work. To understand the mechanisms of corrosion attack, comprehensive analysis of corrosion products...... was necessary. In the present work, two complementary methodologies based on analysis of cross sections and plan views were applied to achieve comprehensive characterization of corrosion products. The suitability of these methods for both laboratory scale and full scale corrosion investigations was demonstrated...

  15. NASA's Corrosion Technology Laboratory at the Kennedy Space Center: Anticipating, Managing, and Preventing Corrosion

    Science.gov (United States)

    Calle, Luz Marina

    2015-01-01

    The marine environment at NASAs Kennedy Space Center (KSC) has been documented by ASM International (formerly American Society for Metals) as the most corrosive in North America. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pads were rendered even more severe by the highly corrosive hydrochloric acid (HCl) generated by the solid rocket boosters (SRBs). Numerous failures at the launch pads are caused by corrosion. The structural integrity of ground infrastructure and flight hardware is critical to the success, safety, cost, and sustainability of space missions. NASA has over fifty years of experience dealing with unexpected failures caused by corrosion and has developed expertise in corrosion control in the launch and other environments. The Corrosion Technology Laboratory at KSC evolved, from what started as an atmospheric exposure test site near NASAs launch pads, into a capability that provides technical innovations and engineering services in all areas of corrosion for NASA, external partners, and customers.This paper provides a chronological overview of NASAs role in anticipating, managing, and preventing corrosion in highly corrosive environments. One important challenge in managing and preventing corrosion involves the detrimental impact on humans and the environment of what have been very effective corrosion control strategies. This challenge has motivated the development of new corrosion control technologies that are more effective and environmentally friendly. Strategies for improved corrosion protection and durability can have a huge impact on the economic sustainability of human spaceflight operations.

  16. Titanium corrosion in alkaline hydrogen peroxide environments

    Science.gov (United States)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  17. Change in physical and chemical characteristics related to the binomial time-temperature used in sous pasteurization see Tambaqui (Colossoma macropomum

    Directory of Open Access Journals (Sweden)

    H.C.A. Kato

    2016-02-01

    Full Text Available The goal of this study was to evaluate sous vide fish and assess the influence of time and temperature on the pasteurization process through quality parameters. The raw material (tambaqui fillets and the sous vide underwent physical, physicochemical, and microbiological analyses. A sauce was prepared containing soy sauce, water, horseradish and garlic flakes. The product's pasteurization parameters of time and temperature were defined according to a 22 central composite rotatable design (CCRD, and the dependent variables were water holding capacity (WHC and instrumental texture aiming at obtaining high WHC values for the product to maintain the desired juiciness. The microbiological analysis required by legislation have indicated that the fish fillets and sous vide were within de standard. The values of total coliforms found in the samples (fillets and sous vide analyzed were below the critical level of 10² CFU/g. The counts of sulphite-reducing clostridia and psychrotrophic and mesophilic bacteria on plates in the samples were <1x10 CFU/g. In conclusion, temperature was the most important factor in the pasteurization process, significantly contributing to the quality of the final product. The mathematical models proposed were considered predictive for each response.

  18. The Effect of Low Dose Irradiation and Grapefruit Extract on C. perfringens Growth from Spores in sous vide Processed Pork-Based Mexican Entrée

    Science.gov (United States)

    Sous vide, a common cooking method for meat and poultry products is widely used for providing ready-to-eat meals. Traditionally, these products have limited shelf life, ranging from 2 to 3 weeks. However, similar products may be stored for longer periods in the U.S. and other countries, requiring ad...

  19. Corrosion inhibition of a hygroscopic inorganic dust-depressor

    Institute of Scientific and Technical Information of China (English)

    Longzhe Jin; Lu Wang; Dongke Chen

    2006-01-01

    Metallic corrosion is a serious problem in the application of a hygroscopic inorganic dust-depressor. The basic characteristics of a hygroscopic inorganic dust-depressor and its corrosivity, corrosion mechanism, as well as the principle of corrosion inhibition were analyzed. The static mass-loss test was carried out to investigate the corrosion behavior and the effect of the dustdepressor. The static corrosion rates of steel specimens were measured in six different corrosion inhibitor solutions of the dustdepressor, and the suitable corrosion inhibitors for the dust-depressor to reduce the corrosivity were found out.

  20. Microencapsulation Technology for Corrosion Mitigation by Smart Coatings

    Science.gov (United States)

    Buhrow, Jerry; Li, Wenyan; Jolley, Scott; Calle, Luz M.

    2011-01-01

    A multifunctional, smart coating for the autonomous control of corrosion is being developed based on micro-encapsulation technology. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection effectiveness. This paper summarizes the development, optimization, and testing of microcapsules specifically designed to be incorporated into a smart coating that will deliver corrosion inhibitors to mitigate corrosion autonomously. Key words: smart coating, corrosion inhibition, microencapsulation, microcapsule, pH sensitive microcapsule, corrosion inhibitor, corrosion protection pain

  1. Electrochemical characterisation speeds up prediction of corrosion behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Schuring, E.W.; Hooijmans, J.W. [ECN Environment and Energy Engineering, Petten (Netherlands)

    2013-04-15

    The contents of this presentation show the following elements: Introduction; Corrosion in real life; Why Electrochemical characterisation of corrosion; Applications (corrosion resistance coatings, corrosion behaviour (brazed) joints); Available electrochemical corrosion techniques; Standards; Conclusions. In the Conclusions the corrosion screening method is summarized: ECN method fast; within 1h -1 week results depending on test method; Fast pre-selection of promising materials/combinations (cost savings); Determining of corrosion initiation; Determination of corrosion mechanisms and propagation; Life time predictions possible; Strong combination with metallographic post-investigation; Ranking materials / constructions for corrosion performance.

  2. INTERNAL CORROSION MONITORING IN OFFSHORE PLATFORMS

    Directory of Open Access Journals (Sweden)

    Fernando Benedicto Mainier

    2008-08-01

    Full Text Available Corrosion is one of the main causes of failures in equipment and pipes in off-shore oil production. These failures harm the process, slow the production operational chronogram, and generate high costs of maintenance, beyond generation risks to health and environment. Due to the fact that most of the equipment, tubing and pipes of production platforms are made of steel, in general, carbon steel, the industry of petroleum exploration will always coexist with the corrosive process. The use of a Corrosion Monitoring Plan to diagnostic, to control and to manage the evolution of corrosives process in off-shore oil platforms is the strategy proposed in this work to prevent problems as described above. The Internal Corrosion Monitoring Plan (ICMP, is based on lab analysis of the corrosively of fluids and residues showed periodically in off-shore operational platform; in the corrosion rate determined by the periodic use of test bodies installed inside off-shore oil platforms tubing systems, as mass loss coupons and electric resistance probes; and finally, in periodic operational data collect obtained during the off-shore oil platform systems operation. The ICMP will direct and manage the actions to be taken in case of aggravation of a corrosive process, quickly identifying to the corrosive mechanisms and its localization in the various systems of the platforms. The optimized use of the corrosion inhibitor and other chemical products are one of the main advantages of the ICMP.

  3. Corrosion Protection of Electrically Conductive Surfaces

    Directory of Open Access Journals (Sweden)

    Jian Song

    2012-11-01

    Full Text Available The basic function of the electrically conductive surface of electrical contacts is electrical conduction. The electrical conductivity of contact materials can be largely reduced by corrosion and in order to avoid corrosion, protective coatings must be used. Another phenomenon that leads to increasing contact resistance is fretting corrosion. Fretting corrosion is the degradation mechanism of surface material, which causes increasing contact resistance. Fretting corrosion occurs when there is a relative movement between electrical contacts with surfaces of ignoble metal. Avoiding fretting corrosion is therefore extremely challenging in electronic devices with pluggable electrical connections. Gold is one of the most commonly used noble plating materials for high performance electrical contacts because of its high corrosion resistance and its good and stable electrical behavior. The authors have investigated different ways to minimize the consumption of gold for electrical contacts and to improve the performance of gold plating. Other plating materials often used for corrosion protection of electrically conductive surfaces are tin, nickel, silver and palladium. This paper will deal with properties and new research results of different plating materials in addition to other means used for corrosion protection of electrically conductive surfaces and the testing of corrosion resistance of electrically conductive surfaces.

  4. 49 CFR 192.477 - Internal corrosion control: Monitoring.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control: Monitoring. 192.477... Control § 192.477 Internal corrosion control: Monitoring. If corrosive gas is being transported, coupons... internal corrosion. Each coupon or other means of monitoring internal corrosion must be checked two...

  5. 49 CFR 192.491 - Corrosion control records.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Corrosion control records. 192.491 Section 192.491... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.491 Corrosion... detail to demonstrate the adequacy of corrosion control measures or that a corrosive condition does...

  6. Corrosion Behaviour of Titanium Anodized Film in Different Corrosive Environments

    Directory of Open Access Journals (Sweden)

    Mr. Sunil D. Kahar

    2014-07-01

    Full Text Available Anodizing is an electrochemical process in which thickness of the natural oxide layer is increased and converted it into a decorative, durable, corrosion-resistant film. Titanium is used as a biocompatible material in human implants due to its excellent corrosion and wears resistance. Stable, continuous, highly adherent, and protective oxide films can be developed on titanium using various acid or alkaline baths. Anodizing of titanium generates a spectrum of different color without use of dyes. This spectrum of color dependent on the thickness of the oxide, voltage ranges, interference of light reflecting off the oxide surface and reflecting off the underlying metal surface. The anodized film of Titanium is mainly consists of TiO2 or mixtures of TiO2 & Ti2O3 etc. In the present work, Pure Titanium plate has been anodized using bath of Chromic Acid at different voltage range. The anodized film is characterized by visual observation, SEM & EDAX analysis & A.C Impedance Spectroscopy, while the corrosion studies were performed using Potentiodynamic studies were performed in 3.5% NaCl & 0.1N H2SO4. The Results show that the anodized film of Titanium show different spectrum of colors from Brown-Violet-Tea or Peacock. SEM & EDAX analyses show that the anodized film of Titanium is mainly made up of TiO2 and Ti2O3. Potentiodynamic study implies that the film developed on Titanium using the bath of Chromic Acid exhibits good corrosion resistance. The A.C. Impedance study shows that the film is more compact, adherent and more uniform in chromic acid bath.

  7. A non-destructive test method to monitor corrosion products and corrosion-induced cracking in reinforced cement based materials

    DEFF Research Database (Denmark)

    Michel, Alexander; Pease, Bradley Justin; Peterova, Adela;

    2011-01-01

    ) was conducted to describe the impact of water-to-cement ratio and corrosion current density (i.e., corrosion rate) on the reinforcement corrosion process. Focus was placed, in particular on the determination of the corrosion accommodating region (CAR) and time to corrosion-induced cracking. Experimental results...

  8. Les images en géographie sous l’angledes humanités numériques

    Directory of Open Access Journals (Sweden)

    Gaëlle Hallair

    2009-04-01

    Full Text Available L’article présente une méthodologie pour conserver, stocker, inventorier, archiver, numériser, indexer, valoriser et diffuser des archives géographiques sous l’angle des Digital humanities. L’article applique cette méthodologie aux images en géographie avant de présenter un projet de plate-forme documentaire concernant les plaques de verres du fonds Emmanuel de Martonne hébergées actuellement par l’UMR CNRS 8586 PRODIG.This article points out the methodology of Digital humanities to preserve, to stock, to make an inventory, to digitize, to index, to enhance the value und to spread geographical archives. It applies this methodology to geographical visual documents and presents a database project about photographic plates of the Emmanuel de Martonne’s collection localised in the research center PRODIG (UMR CNRS 8586.

  9. Influence of Citric Acid on the Pink Color and Characteristics of Sous Vide Processed Chicken Breasts During Chill Storage.

    Science.gov (United States)

    Kim, Ji-Han; Hong, Go-Eun; Lim, Ki-Won; Park, Woojoon; Lee, Chi-Ho

    2015-01-01

    Chicken breast dipped with citric acid (CA) was treated by sous vide processing and stored in a refrigerated state for 0, 3, 6, 9, and 14 d. A non-dipped control group (CON) and three groups dipped in different concentrations of citric acid concentration were analyzed (0.5%, 0.5CIT; 2.0%, 2CIT and 5.0%, 5CIT; w/v). Cooking yield and moisture content increased due to the citric acid. While the redness of the juice and meat in all groups showed significant increase during storage, the redness of the citric acid groups was reduced compared to the control group (psous vide chicken breast at 2% and 5% citric acid concentrations.

  10. Effect of different temperature-time combinations on lipid and protein oxidation of sous-vide cooked lamb loins.

    Science.gov (United States)

    Roldan, Mar; Antequera, Teresa; Armenteros, Monica; Ruiz, Jorge

    2014-04-15

    Forty-five lamb loins were subjected to sous-vide cooking at different combinations of temperature (60, 70 and 80 °C) and time (6, 12 and 24 h) to assess the effect on the oxidative stability of lipids and proteins. Heating induced both lipid and protein oxidation in lamb loins. Higher cooking temperature-time combinations increased conjugated dienes and decreased thiobarbituric reactive substances (TBARS) values and hexanal. Total protein carbonyls increased throughout time at all cooking temperatures considered, while α-aminoadipic (AAS) and γ-glutamic semialdehydes (GGS) increased when cooking at 60 °C but not at 80 °C. Links between the decrease in secondary compounds from lipid oxidation due to cooking at higher temperatures and for longer times with the increased levels of 3-methylbutanal and greater differences between total protein carbonyls and AAS plus GGS were hypothesised. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Contribution à l'utilisation de sous-produits industriels : application au cas du phosphogypse de Sfax ( Tunisie)

    OpenAIRE

    Rouis, Badreddine

    1991-01-01

    Le travail exposé dans ce mémoire est une approche pour la réutilisation d'un sous produit industriel: Le PHOSPHOGYPSE. Nous avons commencé par un rappel du cadre géo-politique de cette étude en précisant l'origine du matériau, son mode de stockage et son incidence sur l'environnement de la ville de SFAX (Tunisie). En deuxième partie, nous avons étudié la possibilité de l'utilisation du phosphogypse en remblai en effectuant une série d'essais géotechniques dont le paramètre principal est la t...

  12. Clostridium perfringens growth from spore inocula in sous-vide processed pork-based Mexican entrée.

    Science.gov (United States)

    Miguel-Garcia, Denise Y; Juneja, Vijay K; Valenzuela-Melendrez, Martin; Díaz-Cinco, Martha E; Thippareddi, H; Aida Peña-Ramos, E

    2009-01-01

    The combined effect of Citricidal wih irradiation on Clostridium perfringens growth from spores in a sous-vide processed marinated pork meat Mexican entrée was investigated. Citricidal was added at 200 or 800 ppm after mixing pork meat with tomatillo sauce and inoculated with 3 log(10) CFU/g of C. perfringens spores. Samples were irradiated at either 0 or 2 kGy, heated to an internal temperature of 71 degrees C, and stored at 4 degrees C for 28 d, 15 degrees C for 45 d, and 25 degrees C for 26 h. To simulate the conditions that may occur during transportation, distribution, storage, or handling in supermarkets or by consumers, the effect of static temperature abuse on C. perfringens growth was assessed by transferring samples stored at 4 to 25 degrees C for 13 and 15 h. Total C. perfringens populations were determined by plating diluted samples on tryptose-sulfite-cycloserine agar. Growth was not observed up to 45 d of storage at 15 degrees C in samples supplemented with 800 ppm of Citricidal. At 25 degrees C, no significant differences (P > 0.05) on the lag phase duration due to antimicrobial treatments was observed. The temperature abuse of refrigerated products for up to 15 h did not lead to C. perfringens growth to high infective dose levels of 1 million cells required to cause food poisoning. The results suggest that 800 ppm Citricidal can have significant bacteriostatic activity against C. perfringens and may provide a degree of protection against this pathogen in sous-vide processed marinated pork meat Mexican entrée, under mild temperature abuse (

  13. Survival characteristics and the applicability of predictive mathematical modelling to Listeria monocytogenes growth in sous vide products.

    Science.gov (United States)

    Nyati, H

    2000-06-01

    Survival and growth of Listeria monocytogenes isolates during sous vide processing and storage, and the applicability of predictive modelling in determining the potential for growth of L. monocytogenes in broth models and in sous vide products was investigated. L. monocytogenes grew in anaerobic tryptose phosphate broth and in chicken and beef samples by 2 log cycles in 8 days at 3 degrees C and 4-5 log cycles in 6 days at 8 degrees C. However, heating to an internal temperature of 70 degrees C resulted in a 4-5 log reduction and 70 degrees C/2 min resulted in a reduction greater than 7 log cycles. Lowering the product pH to 5.0 was effective in inhibiting L. monocytogenes growth, whereas a sodium chloride concentration of 2% had a negligible effect on growth rates. The square root model (Ratkowsky et al., 1983) predicted L. monocytogenes growth rates at 0-25 degrees C with a coefficient of determination (R2 value) of 98.36-99.63% and a bias factor of 1.08 to 1.21 in beef, chicken and broth substrates of unmodified pH. In addition, the Response Surface Polynomial Model (Version 3.1, Buchanan et al., 1989) predicted generation times at 5-25 degrees C with a 0-17.4% difference between observed and expected generation times in tryptose phosphate broth at pH 7.3. There were however, large differences (25.5 vs. 5.3 h) between observed generation times at pH 5.6 (8 degrees C) and those predicted by the Pathogen Modelling Program in tryptose phosphate broth. A divergence from predicted values was also noted at lower temperatures (0-3.5 degrees C) in the square root model.

  14. Corrosion-Activated Micro-Containers for Environmentally Friendly Corrosion Protective Coatings

    Science.gov (United States)

    Li, Wenyan; Buhrow, J. W.; Zhang, X.; Johnsey, M. N.; Pearman, B. P.; Jolley, S. T.; Calle, L. M.

    2016-01-01

    This work concerns the development of environmentally friendly encapsulation technology, specifically designed to incorporate corrosion indicators, inhibitors, and self-healing agents into a coating, in such a way that the delivery of the indicators and inhibitors is triggered by the corrosion process, and the delivery of self-healing agents is triggered by mechanical damage to the coating. Encapsulation of the active corrosion control ingredients allows the incorporation of desired autonomous corrosion control functions such as: early corrosion detection, hidden corrosion detection, corrosion inhibition, and self-healing of mechanical damage into a coating. The technology offers the versatility needed to include one or several corrosion control functions into the same coating.The development of the encapsulation technology has progressed from the initial proof-of-concept work, in which a corrosion indicator was encapsulated into an oil-core (hydrophobic) microcapsule and shown to be delivered autonomously, under simulated corrosion conditions, to a sophisticated portfolio of micro carriers (organic, inorganic, and hybrid) that can be used to deliver a wide range of active corrosion ingredients at a rate that can be adjusted to offer immediate as well as long-term corrosion control. The micro carriers have been incorporated into different coating formulas to test and optimize the autonomous corrosion detection, inhibition, and self-healing functions of the coatings. This paper provides an overview of progress made to date and highlights recent technical developments, such as improved corrosion detection sensitivity, inhibitor test results in various types of coatings, and highly effective self-healing coatings based on green chemistry. The NASA Kennedy Space Centers Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion

  15. Electrochemical corrosion testing of metal waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, D. P.; Peterson, J. J.; Katyal, H. K.; Keiser, D. D.; Hilton, B. A.

    1999-12-14

    Electrochemical corrosion tests have been conducted on simulated stainless steel-zirconium (SS-Zr) metal waste form (MWF) samples. The uniform aqueous corrosion behavior of the samples in various test solutions was measured by the polarization resistance technique. The data show that the MWF corrosion rates are very low in groundwaters representative of the proposed Yucca Mountain repository. Galvanic corrosion measurements were also conducted on MWF samples that were coupled to an alloy that has been proposed for the inner lining of the high-level nuclear waste container. The experiments show that the steady-state galvanic corrosion currents are small. Galvanic corrosion will, hence, not be an important mechanism of radionuclide release from the MWF alloys.

  16. CORROSION MONITORING OF PLUTONIUM OXIDE AND SNF

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, D.G.; Haas, C.M.; Smith, C.M.; Ohl, P.C.

    2003-02-27

    While developing a method to measure pressure in totally sealed stainless steel containers holding spent nuclear fuel at the U.S. DOE Hanford Site, Vista Engineering Technologies, LLC (Vista Engineering) personnel adapted the central concept to corrosion monitoring techniques for the same containers. The ability to monitor corrosion within vessels containing spent nuclear fuel, plutonium and other hazardous materials is imperative for safe storage. Vista Engineering personnel have devised a way to monitor corrosion in a totally sealed stainless steel container using a Magnetically Coupled Corrosion Gauge (MCCG) Patent Pending. The MCCG can be used to detect corrosion as well as measure corrosion rate and does not require any penetration of the containment vessel, which minimizes pressure boundary surface area and sensitive weld materials in the vessels.

  17. Microbiologically Influenced Corrosion: an Update

    Science.gov (United States)

    2014-01-01

    the material that failed was carbon steel and the electrolyte were saline waters, but the microorgan- isms, the environments and the corrosion...different salinities . Martin et al.42 demonstrated that Ecorr ennoblement was site specific, varying 100 mV versus SCE between locations, with higher...microbial consortium of the fungus Aspergillus niger and bacteria influenced the corrosion–inhibiting effectiveness of Crz6 leached from chromate (CrO{24

  18. Aluminum corrosion product release kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Matt, E-mail: Matthew.Edwards@cnl.ca; Semmler, Jaleh; Guzonas, Dave; Chen, Hui Qun; Toor, Arshad; Hoendermis, Seanna

    2015-07-15

    Highlights: • Release of Al corrosion product was measured in simulated post-LOCA sump solutions. • Increased boron was found to enhance Al release kinetics at similar pH. • Models of Al release as functions of time, temperature, and pH were developed. - Abstract: The kinetics of aluminum corrosion product release was examined in solutions representative of post-LOCA sump water for both pressurized water and pressurized heavy-water reactors. Coupons of AA 6061 T6 were exposed to solutions in the pH 7–11 range at 40, 60, 90 and 130 °C. Solution samples were analyzed by inductively coupled plasma atomic emission spectroscopy, and coupon samples were analyzed by secondary ion mass spectrometry. The results show a distinct “boron effect” on the release kinetics, expected to be caused by an increase in the solubility of the aluminum corrosion products. New models were developed to describe both sets of data as functions of temperature, time, and pH (where applicable)

  19. Corrosion behavior in heat pipe

    Directory of Open Access Journals (Sweden)

    Anurak Rodbumrung

    2016-01-01

    Full Text Available The aim of this study was to perform life testing and determine the effect of working fluid on the corrosion of a heat pipe with a sintered wick. The heat pipe was made from a copper tube. The inner heat pipe was filled with 99.97% pure copper powder as a dendritic for the sintering process. The heat pipe had an outer diameter of 6 mm with a length of 200 mm, and distilled water and ethanol were the working fluids. The operating temperature at the evaporator was 125°C. The analysis consisted of using a scanning electron microscope, energy dispersive X-ray spectrometry and atomic absorption spectroscopy. The results of the scanning electron microscope and energy dispersive X-ray spectrometry analysis showed that the corrosion of the heat pipe was uniform. The result of the atomic absorption spectroscopy indicated that the concentration of the copper in the ethanol as the working fluid was greater than in the distilled water as the working fluid, and the highest concentration of copper particles in the ethanol was 22.7499 ppm or 0.0409 mg after testing for 3000 h. The concentration of copper was higher when the length of the life test increased due to corrosion of the heat pipe.

  20. Corrosion Preventive Compounds Lifetime Testing

    Science.gov (United States)

    Hale, Stephanie M.; Kammerer, Catherine C.; Copp, Tracy L.

    2007-01-01

    Lifetime Testing of Corrosion Preventive Compounds (CPCs) was performed to quantify performance in the various environments to which the Space Shuttle Orbiter is exposed during a flight cycle. Three CPCs are approved for use on the Orbiter: RD Calcium Grease, Dinitrol AV-30, and Braycote 601 EF. These CPCs have been rigorously tested to prove that they mitigate corrosion in typical environments, but little information is available on how they perform in the unique combination of the coastal environment at the launch pad, the vacuum of low-earth orbit, and the extreme heat of reentry. Currently, there is no lifetime or reapplication schedule established for these compounds that is based on this combination of environmental conditions. Aluminum 2024 coupons were coated with the three CPCs and exposed to conditions that simulate the environments to which the Orbiter is exposed. Uncoated Aluminum 2024 coupons were exposed to the environmental conditions as a control. Visual inspection and Electro- Impedance Spectroscopy (EIS) were performed on the samples in order to determine the effectiveness of the CPCs. The samples were processed through five mission life cycles or until the visual inspection revealed the initiation of corrosion and EIS indicated severe degradation of the coating.

  1. Corrosion performance of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.

    1993-03-01

    Iron aluminides are being developed for use as structural materials and/or cladding alloys in fossil energy systems. Extensive development has been in progress on Fe{sub 3}Al-based alloys to improve the engineering ductility of these alloys. This paper describes results from the ongoing program to evaluate the corrosion performance of these alloys. The experimental program at Argonne National Laboratory involvesthermogravimetric analyses of alloys exposed to environments that simulate coal gasification and fluidized-bed combustion. Experiments were conducted at 650--1000{degrees}C in simulated oxygen/sulfur gas mixtures. In addition, oxidation/sulfidation behavior of several alumina-forming Fe-Al and Fe-Cr-Ni-Al alloys was determined for comparison with the corrosion rates obtained on iron aluminides. Other aspects of the program are corrosion evaluation of the aluminides in the presence of HC1-containing gases and in the presence of slag from a slogging gasifier. Results are used to establish threshold Al levels in the alloys for development of protective alumina scales. Thermal cycling tests are used to examine the spalling resistance of the scales.

  2. Corrosion performance of iron aluminides

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.

    1993-03-01

    Iron aluminides are being developed for use as structural materials and/or cladding alloys in fossil energy systems. Extensive development has been in progress on Fe[sub 3]Al-based alloys to improve the engineering ductility of these alloys. This paper describes results from the ongoing program to evaluate the corrosion performance of these alloys. The experimental program at Argonne National Laboratory involvesthermogravimetric analyses of alloys exposed to environments that simulate coal gasification and fluidized-bed combustion. Experiments were conducted at 650--1000[degrees]C in simulated oxygen/sulfur gas mixtures. In addition, oxidation/sulfidation behavior of several alumina-forming Fe-Al and Fe-Cr-Ni-Al alloys was determined for comparison with the corrosion rates obtained on iron aluminides. Other aspects of the program are corrosion evaluation of the aluminides in the presence of HC1-containing gases and in the presence of slag from a slogging gasifier. Results are used to establish threshold Al levels in the alloys for development of protective alumina scales. Thermal cycling tests are used to examine the spalling resistance of the scales.

  3. CONTRAINTES INSTITUTIONNELLES ET LABELLISATION DES ...

    African Journals Online (AJOL)

    cicole. Nous nous interrogeons sur la trajectoire d'évolution de ces produits depuis .... Notre grille de lecture se base sur ce que nous appelons les .... géographique, encépagement, pratiques culturales et méthodes de vinification et qualité ...

  4. Optimising corrosion monitoring in district heating systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Thorarinsdottir, R.I.; Andersen, A.

    2002-01-01

    A three-year project - financially supported by the Nordic Industrial Fund - on monitoring of corrosion in district heating systems has been initiated with participation of researchers and industrial partners in Denmark, Finland, Iceland, Norway and Sweden. The primary objective of the project...... is to improve the quality control in district heating systems by corrosion monitoring. In Danish systems electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR), high-sensitive electrical resistance (ER) technology, crevice corrosion probes, as well as weight loss coupons...

  5. Recognition and Analysis of Corrosion Failure Mechanisms

    OpenAIRE

    Steven Suess

    2006-01-01

    Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, materi...

  6. Corrosive acid injury of the stomach.

    Science.gov (United States)

    Wijeratne, T; Ratnatunga, C; Dharrmapala, A; Samarasinghe, T

    2015-03-01

    Ingestion of corrosives with accidental or suicidal intent is a common problem in Sri Lanka. Management options and outcomes of corrosive injuries on stomach are not well documented in our setting. The clinical presentation, complications and management outcomes of nine patients with corrosive injury to stomach are presented. Gastric outlet obstruction seen in majority, was managed with bypass procedure (n=5) or resection (n=4). The outcomes of management were successful with both methods.

  7. The oxidation and corrosion of ODS alloys

    Science.gov (United States)

    Lowell, Carl E.; Barrett, Charles A.

    1990-01-01

    The oxidation and hot corrosion of high temperature oxide dispersion strengthened (ODS) alloys are reviewed. The environmental resistance of such alloys are classified by oxide growth rate, oxide volatility, oxide spalling, and hot corrosion limitations. Also discussed are environmentally resistant coatings for ODS materials. It is concluded that ODS NiCrAl and FeCrAl alloys are highly oxidation and corrosion resistant and can probably be used uncoated.

  8. Oxidation And Hot Corrosion Of ODS Alloy

    Science.gov (United States)

    Lowell, Carl E.; Barrett, Charles A.

    1993-01-01

    Report reviews oxidation and hot corrosion of oxide-dispersion-strengthened (ODS) alloys, intended for use at high temperatures. Classifies environmental resistances of such alloys by rates of growth of oxides, volatilities of oxides, spalling of oxides, and limitations imposed by hot corrosion. Also discusses environmentally resistant coatings for ODS materials. Concludes ODS NICrAl and FeCrAl alloys highly resistant to oxidation and corrosion and can be used uncoated.

  9. Corrosion of oil-fired domestic boilers

    Energy Technology Data Exchange (ETDEWEB)

    Koebel, M.; Elsener, M.

    1989-05-01

    Depending on the surface temperature of the flue gas side the corrosion of oil fired domestic boilers proceeds either mainly by acid corrosion or by oxygen corrosion: (1) At surface temperatures of 60/sup 0/C and higher the corrosion mechanism of acid corrosion prevails and the corrosion rates amount to 0.1-0.3 mm/year (values referred to continuous burner operation). The corrosion products consist of soluble iron(II)- and iron(III)sulfates. Higher corrosion rates can be attributed to an appreciable catalytic formation of sulfur trioxide on the corrosion products formed on the convective heating surfaces. (2) At surface temperatures of 40/sup 0/C the mechanism of oxygen corrosion already dominates and the corrosion rates are about ten times higher (1.5-3 mm/year, referred to continuous burner operation). The high portion of iron oxide hydrates, especially goethit (/alpha/-FeOOH), makes the corrosion products difficult to remove. (3) Distinctly reduced service lives are also expected for the so called reduced temperature boilers ('Niedertemperaturkessel') and low temperature boilers ('Tieftemperaturkessel'): According to the manufacturers these boilers may be operated at boiler water temperatures well below 60/sup 0/C, as they are equipped with constructive measures to enhance the surface temperature on the flue gas side. However, these measures are only fully effective under stationary conditions. Some of the results were obtained from weight loss measurements on test specimen made from St 35.8 and gray cast iron, that were exposed to the flue gases of an fired experimental boiler. Other important results come from field measurements of the sulfuric acid content of about 30 boilers that are in practical use. (orig.).

  10. Natural analogues of nuclear waste glass corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  11. Recognition and Analysis of Corrosion Failure Mechanisms

    OpenAIRE

    Steven Suess

    2006-01-01

    Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, materi...

  12. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove

    1997-01-01

    In this paper the corrosion properties of laser welded AISI 316L stainless steel are examined. A number of different welds has been performed to test the influence of the weld parameters of the resulting corrosion properties. It has been chosen to use the potential independent critical pitting...... temperature (CPT) test as corrosion test. The following welding parameters are varied: Welding speed, lsser power, focus point position and laser operation mode (CW or pulsed)....

  13. Corrosion problems and solutions in oil refining and petrochemical industry

    CERN Document Server

    Groysman, Alec

    2017-01-01

    This book addresses corrosion problems and their solutions at facilities in the oil refining and petrochemical industry, including cooling water and boiler feed water units. Further, it describes and analyzes corrosion control actions, corrosion monitoring, and corrosion management. Corrosion problems are a perennial issue in the oil refining and petrochemical industry, as they lead to a deterioration of the functional properties of metallic equipment and harm the environment – both of which need to be protected for the sake of current and future generations. Accordingly, this book examines and analyzes typical and atypical corrosion failure cases and their prevention at refineries and petrochemical facilities, including problems with: pipelines, tanks, furnaces, distillation columns, absorbers, heat exchangers, and pumps. In addition, it describes naphthenic acid corrosion, stress corrosion cracking, hydrogen damages, sulfidic corrosion, microbiologically induced corrosion, erosion-corrosion, and corrosion...

  14. Accelerated corrosion testing results for specimens containing uncoated reinforcing steel and corrosion inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Kondratova, I. L.; Montes, P.; Bremner, T. W. [New Brunswick Univ., Dept, of Civil Engineering, Fredericton, NB (Canada)

    2000-07-01

    Concrete mixtures (water-cement ratios of 0.25, 0.40. or 0.60) containing uncoated reinforcing bars with a simulated crack, formed transverse to the axis of the bar, and with three commercial corrosion inhibitors added for corrosion protection (organic corrosion inhibitor,calcium nitrate-based corrosion inhibitor, and migratory corrosion inhibitor), were tested for corrosion damage. The objective was to evaluate the effectiveness of the different corrosion inhibitors in uncracked and cracked concrete slabs in a simulated marine environment. The specimens were placed in an accelerated exposure cabinet with four cycles of wetting and drying per day in simulated seawater, and corrosion rates measured using the linear polarization technique. Water-soluble chloride content in the rebars was analyzed at the end of the exposure period. The three corrosion inhibitors were found to show a wide variation in performance. There was a direct correlation between their effectiveness and addition rate. All three appeared to be more effective in reducing corrosion rate in a higher water-to-cement ratio concrete. Consistent performance was provided only by calcium nitrate at an addition rate of 25 litre/cu m of concrete, with water-to-cement ratios of 0.60 and 0.40. Pitting corrosion was observed in all pre-cracked high performance concrete specimens; the depth of the pit tended to be deeper when a corrosion inhibitor was used. 6 refs., 6 tabs., 6 figs.

  15. Caractérisation des contraintes biotiques et abiotiques sur la phénologie printanière du chêne. Expliquer les patrons de diversité et prédire les changements futurs

    OpenAIRE

    Dantec, Cécile

    2014-01-01

    La phénologie du débourrement est un caractère majeur d’adaptation des arbres à leur environnement en milieu tempéré. Notre objectif a été de caractériser les contraintes biotiques (oïdium) et abiotiques (températures hivernales et printanières / gels tardifs) s’exerçant sur le débourrement afin d’expliquer les patrons de variation phénologique intra et inter populationnelle observés chez le chêne (Quercus petraea) le long d’un gradient altitudinal. Nous avons utilisé une approche combinant o...

  16. L'eau sur le site d'Alésia : la contrainte hydrogéologique lors du siège de 52 av. J.-C.

    OpenAIRE

    Vidal, Jonhattan; Petit, Christophe

    2010-01-01

    Le Mont-Auxois, lieu du siège d’Alésia, a fait l’objet d’une étude de terrain destinée à définir les contraintes naturelles du milieu d’un point de vue hydrogéologique. Nous abordons, à partir des connaissances archéologiques et historiques, l’influence de cet environnement lors d’une situation exceptionnelle comme celle de 52 av. J.-C. Une quantification de l’eau disponible en période estivale, associée aux connaissances sur les positions des belligérants lors du siège, nous informe plus pré...

  17. Orientation de la contrainte tectonique pans l'Europe de l'Ouest à partir des ovalisations de trous de forages Orientation of Tectonic Stress in Western Europe from Borehole Breakouts

    Directory of Open Access Journals (Sweden)

    Janot P.

    2006-11-01

    Full Text Available La recherche de l'orientation de la contrainte majeure horizontale actuelle à partir de l'ovalisation des trous de forages (Synthèse exposée dans le numéro mai-juin 1988 de la Revue de l'institut Français du Pétrole, permet de déceler la direction des systèmes de fractures ouvertes en condition de fond. L'ovalisation des trous de forages, détectée par la Pendagemétrie 4 patins en relation avec l'écaillage d'un secteur des parois du sondage, conduit, après tri de l'information, à la connaissance de la direction de la contrainte majeure horizontale actuelle, localement, au voisinage du puits. L'établissement d'une carte de ces orientations pour l'Europe de l'Ouest, de l'Italie à la Norvège, montre une grande cohérence dans les directions obtenues par cette méthode. Cette cohérence s'explique par l'orientation générale des forces nées de la collision actuelle des plaques Afrique (à laquelle appartient l'Italie et Europe (Aquitaine, Bassin Parisien, mer du Nord. Cependant, cette carte met en évidence un certain nombre d'anomalies (Fossé Rhénan, ouest du bassin de Paris, Grabens de mer du Nord par rapport à l'orientation générale de la contrainte actuelle. Ces anomalies (déviation plus ou moins importante de la contrainte s'expliquent, du fait de leur localisation, par l'influence d'accidents tectoniques profonds liés aux anciennes directions de phases orogéniques : calédonienne hercynienne et laramienne. La recherche de ces anomalies pourrait être un moyen de détection de la proximité de ces grands traits structuraux majeurs du socle. Research on the orientation of current major horizontal stress from borehole breakouts (cf. synthesis report in the May-June 1988 issue of the Revue de l'Institut Français du Pétrole reveals the direction of open fracture systems under downhole conditions. Borehole breakout, detected by 4-pad dipmetering in relation to the scaling of one sector of borehole walls leads, after the

  18. New corrosion issues in gas sweetening plants

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, R.G. (CLI International and Asperger Technologies, Houston, TX (United States))

    Gas treating plants are experiencing corrosion problems which impact on efficiency and safety. While general corrosion is not particularly hazardous in the gas processing industry, local corrosion is very dangerous since it has several different mechanisms, all of which have dangerously high rates, and it occurs at locations which are hard to find and hard to predict. A newly discovered, velocity-dependent type of corrosion is reported. It is related to yet-undefined species which cause excessively high corrosion in areas of turbulence. This accelerated corrosion is not due to erosion or cavitation, but to a diffusion-limited reaction accelerated by turbulence. A full-flow test loop was built to evaluate the corrosiveness of gas plant solutions at their normal temperature and flow rates. Test runs were conducted with Co[sub 2]-loaded amine solutions for periods of 12 days. Carbon steel specimens mounted in the test loop were examined and corrosion rates calculated. Chromium alloys were shown to be attacked by corrodents in the low-velocity part of the loop and very aggressively attacked in the high-velocity part. The tests demonstrate the need for rigorous monitoring of corrosion in areas of higher velocity such as piping elbows and other points of turbulence. 5 refs., 2 figs., 3 tabs.

  19. Fouling corrosion in aluminum heat exchangers

    Directory of Open Access Journals (Sweden)

    Su Jingxin

    2015-06-01

    Full Text Available Fouling deposits on aluminum heat exchanger reduce the heat transfer efficiency and cause corrosion to the apparatus. This study focuses on the corrosive behavior of aluminum coupons covered with a layer of artificial fouling in a humid atmosphere by their weight loss, Tafel plots, electrochemical impedance spectroscopy (EIS, and scanning electron microscope (SEM observations. The results reveal that chloride is one of the major elements found in the fouling which damages the passive film and initiates corrosion. The galvanic corrosion between the metal and the adjacent carbon particles accelerates the corrosive process. Furthermore, the black carbon favors the moisture uptake, and gives the dissolved oxygen greater chance to migrate through the fouling layer and form a continuous diffusive path. The corrosion rate decreasing over time is conformed to electrochemistry measurements and can be verified by Faraday’s law. The EIS results indicate that the mechanism of corrosion can be interpreted by the pitting corrosion evolution mechanism, and that pitting was observed on the coupons by SEM after corrosive exposure.

  20. Classification of corrosion risk zones using GIS

    Science.gov (United States)

    Georgiou, Nikolas; Anastasiou, Constantina; Tantele, Elia A.; Votsis, Renos A.; Danezis, Chris

    2016-08-01

    Corrosion of steel reinforcement is the major deterioration factor of the RC infrastructures. Several factors are contributing towards increasing the corrosion risk like the exposure and environmental conditions which are a function of the geographical location of the infrastructure. Information for these conditions and their affected areas can be proved valuable at design stage and/or during maintenance planning. This study aims to relate corrosion risk of RC infrastructures with their geographical location. The corrosion risk is quantified through data from NDT methods and subsequently correlated with its location. Therefore high risk areas with structures prone to corrosion deterioration are identified. The latter is implemented via GIS tools in order to create maps that describe how corrosion risk is related to the location of each structure. Two GIS methods are suggested, the grid system and the use of classified areas. Corrosion data has been collected from labs about various constructions in Cyprus and used in conjunction with GIS tools to provide useful information on corrosion identification. The outcome is a digitized map of the Limassol area which indicates the risks levels associated with corrosion of the steel reinforcement.

  1. NOVEL CORROSION SENSOR FOR VISION 21 SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Heng Ban

    2004-12-01

    Advanced sensor technology is identified as a key component for advanced power systems for future energy plants that would have virtually no environmental impact. This project intends to develop a novel high temperature corrosion sensor and subsequent measurement system for advanced power systems. Fireside corrosion is the metal loss caused by chemical reactions on surfaces exposed to the combustion environment. Such corrosion is the leading mechanism for boiler tube failures and has emerged to be a significant concern for current and future energy plants due to the introduction of technologies targeting emissions reduction, efficiency improvement, or fuel/oxidant flexibility. Corrosion damage can lead to catastrophic equipment failure, explosions, and forced outages. Proper management of corrosion requires real-time indication of corrosion rate. However, short-term, on-line corrosion monitoring systems for fireside corrosion remain a technical challenge to date due to the extremely harsh combustion environment. The overall objective of this proposed project is to develop a technology for on-line corrosion monitoring based on a new concept. This report describes the initial results from the first-year effort of the three-year study that include laboratory development and experiment, and pilot combustor testing.

  2. Recent Corrosion Research Trends in Weld Joints

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hwan Tae; Kil, Sang Cheol [Korea Institute of Science and Technology Information, Seoul (Korea, Republic of); Hwang, Woon Suk [Inha University, Incheon (Korea, Republic of)

    2007-04-15

    The increasing interest in the corrosion properties of weld joints in the corrosive environment is placing stringent demands on the manufacturing techniques and performance requirements, and the manufacture employs the high quality and efficiency welding process to produce welds. Welding plays an important role in the fabrication of chemical plants, nuclear power plant, ship construction, and this has led to an increasing attention to the corrosion resistant weld joints. This paper covers recent technical trends of welding technologies for corrosion resistance properties including the COMPENDEX DB analysis of welding materials, welding process, and welding fabrications

  3. Corrosion Fatigue in District Heating Water Tanks

    DEFF Research Database (Denmark)

    Maahn, Ernst Emanuel

    1996-01-01

    Three candidate materials for construction of buffer tanks for district heating water have been tested for corrosion fatigue properties in a district heating water environment. The investigation included Slow Strain Rate Testing of plain tensile specimens, crack initiation testing by corrosion...... fatigue of plain tensile specimens and crack growth rate determination for Compact Tensile Specimens under corrosion fatigue conditions. The three materials are equal with respect to stress corrosion sensibility and crack initiation. Crack growth rate is increased with a factor of 4-6 relative to an inert...

  4. The effect of organic matter associated with the corrosion products on the corrosion of mild steel in the Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Wagh, A.B.

    the corrosion of mild steel and the temperature and dissolved oxygen of seawater. In contrast to this, the corrosion and mild steel was inversely related to the organic carbon and water extractable carbohydrates associated with the corrosion products of mild...

  5. NASA's Corrosion Technology Laboratory at the Kennedy Space Center: Anticipating, Managing, and Preventing Corrosion

    Science.gov (United States)

    Calle, Luz Marina

    2014-01-01

    Corrosion is the degradation of a material that results from its interaction with the environment. The marine environment at NASAs Kennedy Space Center (KSC) has been documented by ASM International (formerly American Society for Metals) as the most corrosive in the United States. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pads were rendered even more severe by the 70 tons of highly corrosive hydrochloric acid that were generated by the solid rocket boosters. Numerous failures at the launch pads are caused by corrosion.The structural integrity of ground infrastructure and flight hardware is critical to the success, safety, cost, and sustainability of space missions. As a result of fifty years of experience with launch and ground operations in a natural marine environment that is highly corrosive, NASAs Corrosion Technology Laboratory at KSC is a major source of corrosion control expertise in the launch and other environments. Throughout its history, the Laboratory has evolved from what started as an atmospheric exposure facility near NASAs launch pads into a world-wide recognized capability that provides technical innovations and engineering services in all areas of corrosion for NASA and external customers.This presentation will provide a historical overview of the role of NASAs Corrosion Technology in anticipating, managing, and preventing corrosion. One important challenge in managing and preventing corrosion involves the detrimental impact on humans and the environment of what have been very effective corrosion control strategies. This challenge has motivated the development of new corrosion control technologies that are more effective and environmentally friendly. Strategies for improved corrosion protection and durability can have a huge impact on the economic sustainability of human spaceflight operations.

  6. Environmental Friendly Coatings and Corrosion Prevention For Flight Hardware Project

    Science.gov (United States)

    Calle, Luz

    2014-01-01

    Identify, test and develop qualification criteria for environmentally friendly corrosion protective coatings and corrosion preventative compounds (CPC's) for flight hardware an ground support equipment.

  7. Civil Engineering Corrosion Control. Volume 1. Corrosion Control - General

    Science.gov (United States)

    1975-01-01

    source, consisting of " artificial " anodes energized by rectified A.C. or galvanic voltage, is used. Where current leaves a metal surface, corrosion occurs...additional data. 2 Losses of weight sustained by 5.1- by 10.2- cm. (2- by 4- inc.) specimens made of open- hearth iron (0.007 percent copper) are used as a...Al(OH)3 ) that forms, tending to prevent further cor- rosion. This film can be artificially induced by anodizing, passing electric current through

  8. High Temperature Corrosion under Laboratory Conditions Simulating Biomass-Firing: A Comprehensive Characterization of Corrosion Products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2014-01-01

    characterization of the corrosion products. The corrosion products consisted of three layers: i) the outermost layer consisting of a mixed layer of K2SO4 and FexOy on a partly molten layer of the initial deposit, ii) the middle layer consists of spinel (FeCr2O4) and Fe2O3, and iii) the innermost layer is a sponge......-like Ni3S2 containing layer. At the corrosion front, Cl-rich protrusions were observed. Results indicate that selective corrosion of Fe and Cr by Cl, active oxidation and sulphidation attack of Ni are possible corrosion mechanisms....

  9. Colorimetric visualization of tin corrosion: A method for early stage corrosion detection on printed circuit boards

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2017-01-01

    A majority of printed circuit board surfaces are covered with tin, therefore tin corrosion under humid conditions and movement of tin ions under the influence of an electric field plays an important role in the corrosion failure development. Tracking tin corrosion products spread on the printed...... a colorimetric tin ion indicator applied as a gel. The examples provided in this paper include visualization of corrosion caused by weak organic acids found in solder fluxes, corrosion profiling on the PCBAs after climatic device level testing, and failure analysis of field returns....

  10. Screening of soil corrosivity by field testing: Results and design of an electrochemical soil corrosion probe

    DEFF Research Database (Denmark)

    Nielsen, Lars vendelbo; Bruun, Niels Kåre

    1996-01-01

    The corrosivity of different types of soil have been assessed by exposing carbon-steel plates at 50 different locations in Denmark for an extended period of time. The investigations included weight loss measurements and analysis of the chemical compositions of the corrosion products formed...... on the plates during exposure. An electrochemical soil corrosion probe has been designed and manufactured allowing for simultaneous measurements of several qauntities to predict corrosion. The probe consists of individual sections capable of measuring redox-potential, corrosion potential, soil resistivity...

  11. High Temperature Corrosion under Laboratory Conditions Simulating Biomass-Firing: A Comprehensive Characterization of Corrosion Products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2014-01-01

    characterization of the corrosion products. The corrosion products consisted of three layers: i) the outermost layer consisting of a mixed layer of K2SO4 and FexOy on a partly molten layer of the initial deposit, ii) the middle layer consists of spinel (FeCr2O4) and Fe2O3, and iii) the innermost layer is a sponge......-like Ni3S2 containing layer. At the corrosion front, Cl-rich protrusions were observed. Results indicate that selective corrosion of Fe and Cr by Cl, active oxidation and sulphidation attack of Ni are possible corrosion mechanisms....

  12. Novel Corrosion Sensor for Vision 21 Systems

    Energy Technology Data Exchange (ETDEWEB)

    Heng Ban; Bharat Soni

    2007-03-31

    Advanced sensor technology is identified as a key component for advanced power systems for future energy plants that would have virtually no environmental impact. This project intends to develop a novel high temperature corrosion sensor and subsequent measurement system for advanced power systems. Fireside corrosion is the leading mechanism for boiler tube failures and has emerged to be a significant concern for current and future energy plants due to the introduction of technologies targeting emissions reduction, efficiency improvement, or fuel/oxidant flexibility. Corrosion damage can lead to catastrophic equipment failure, explosions, and forced outages. Proper management of corrosion requires real-time indication of corrosion rate. However, short-term, on-line corrosion monitoring systems for fireside corrosion remain a technical challenge to date due to the extremely harsh combustion environment. The overall goal of this project is to develop a technology for on-line fireside corrosion monitoring. This objective is achieved by the laboratory development of sensors and instrumentation, testing them in a laboratory muffle furnace, and eventually testing the system in a coal-fired furnace. This project successfully developed two types of sensors and measurement systems, and successful tested them in a muffle furnace in the laboratory. The capacitance sensor had a high fabrication cost and might be more appropriate in other applications. The low-cost resistance sensor was tested in a power plant burning eastern bituminous coals. The results show that the fireside corrosion measurement system can be used to determine the corrosion rate at waterwall and superheater locations. Electron microscope analysis of the corroded sensor surface provided detailed picture of the corrosion process.

  13. Corrosion of RoHS-Compliant Surface Finishes in Corrosive Mixed Flowing Gas Environments

    Science.gov (United States)

    Hannigan, K.; Reid, M.; Collins, M. N.; Dalton, E.; Xu, C.; Wright, B.; Demirkan, K.; Opila, R. L.; Reents, W. D.; Franey, J. P.; Fleming, D. A.; Punch, J.

    2012-03-01

    Recently, the corrosion resistance of printed wiring board (PWB) finishes has generated considerable interest due to field failures observed in various parts of the world. This study investigates the corrosion issues associated with the different lead-free PWB surface finishes. Corrosion products on various PWB surface finishes generated in mixed flowing gas (MFG) environments were studied, and analysis techniques such as scanning electron microscopy, energy-dispersive x-ray, x-ray diffraction, focused ion beam, and scanning Auger microscopy were used to quantify the corrosion layer thickness and determine the composition of corrosion products. The corrosion on organic solderability preservative samples shows similar corrosion products to bare copper and is mainly due to direct attack of copper traces by corrosive gases. The corrosion on electroless nickel immersion gold occurs primarily through the porosity in the film and is accelerated by the galvanic potential between gold and copper; similar results were observed on immersion silver. Immersion tin shows excellent corrosion resistance due to its inherent corrosion resistance in the MFG environment as well as the opposite galvanic potential between tin and copper compared with gold or silver and copper.

  14. Effect of Flow Velocity on Corrosion Rate and Corrosion Protection Current of Marine Material

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seong Jong [Kunsan National University, Kunsan (Korea, Republic of); Han, Min Su; Jang, Seok Ki; Kim, Seong Jong [Mokpo National Maritime University, Mokpo (Korea, Republic of)

    2015-10-15

    In spite of highly advanced paint coating techniques, corrosion damage of marine metal and alloys increase more and more due to inherent micro-cracks and porosities in coatings formed during the coating process. Furthermore, flowing seawater conditions promote the breakdown of the protective oxide of the materials introducing more oxygen into marine environments, leading to the acceleration of corrosion. Various corrosion protection methods are available to prevent steel from marine corrosion. Cathodic protection is one of the useful corrosion protection methods by which the potential of the corroded metal is intentionally lowered to an immune state having the advantage of providing additional protection barriers to steel exposed to aqueous corrosion or soil corrosion, in addition to the coating. In the present investigation, the effect of flow velocity was examined for the determination of the optimum corrosion protection current density in cathodic protection as well as the corrosion rate of the steel. It is demonstrated from the result that the material corrosion under dynamic flowing conditions seems more prone to corrosion than under static conditions.

  15. Corrosion Products and Formation Mechanism During Initial Stage of Atmospheric Corrosion of Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    XIAO Kui; DONG Chao-fang; LI Xiao-gang; WANG Fu-ming

    2008-01-01

    The formation and development of corrosion products on carbon steel surface during the initial stage of atmospheric corrosion in a laboratory simulated environment have been studied by scanning electron microscopy (SEM)and Raman spectroscopy.The results showed that two different shapes of corrosion products,that is,ring and chain,were formed in the initial stage of corrosion.MnS clusters were found in the nuclei of corrosion products at the active local corrosion sites.The ring-shaped products were composed of lepidocrocite (γ-FeOOH) and maghemite(γ-Fe2 O3) transformed from lepidocrocite.The chain-type products were goethite (α-FeOOH).A formation mechanism of the corrosion products is proposed.

  16. Corrosion Mechanism of Corrosion-Resistant Steel Developed for Bottom Plate of Cargo Oil Tanks

    Institute of Scientific and Technical Information of China (English)

    Feilong SUN; Xiaogang LI; Fan ZHANG; Xuequn CHENG; Cheng ZHOU; Nianchun WU; Yuqun YIN

    2013-01-01

    A new type of corrosion-resistant steel consisting of ferrite and bainite phases was developed for cargo oil tanks of crude oil tankers.The corrosion rate of this new steel was 0.22 mm/a,which was equivalent to ca.1/5 of the criterion (≤ 1 mm/a) for corrosion-resistant steels.The composition and element distribution of the corrosion products were investigated by micro-Raman spectrometry and energy dispersive spectrometer.The results demonstrated that the corrosion product was composed of α-FeOOH,Fe3O4 and a continuous Cu enrichment layer.This kind of corrosion product was protective to the steel matrix and accounted for the enhancement of the corrosion resistance of the new developed steel.

  17. Field corrosion characterization of soil corrosion of X70 pipeline steel in a red clay soil

    Institute of Scientific and Technical Information of China (English)

    Shengrong Wang; Cuiwei Dun; Xiaogang Li; Zhiyong Liunn; Min Zhu; Dawei Zhang

    2015-01-01

    The corrosion behavior of X70 pipeline steel buried in red soil environment has been studied. The surface morphology and elemental distribution were determined by scanning electron microscopy (SEM),energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion kinetics was evaluated by weight loss measurement. The results show that in red soil, the corrosion rate of X70 steel decreases with time, and follows the exponential decay law. General corrosion with non-uniform and localized pitting occurred on the steel surface.α-FeOOH was the dominate products during corrosion in whole buried periods, and the corrosion products exhibited well protective properties. The potentiodynamic polarization tests revealed that icorr decreased with time, indicating the improvement of corrosion resistance. The results of Electrochemical impendence spectroscopy (EIS) are consistent with potentiodynamic polarization tests.

  18. Field corrosion characterization of soil corrosion of X70 pipeline steel in a red clay soil

    Directory of Open Access Journals (Sweden)

    Shengrong Wang

    2015-06-01

    Full Text Available The corrosion behavior of X70 pipeline steel buried in red soil environment has been studied. The surface morphology and elemental distribution were determined by scanning electron microscopy (SEM,energy dispersive X-ray spectroscopy (EDS, and X-ray diffraction (XRD. The corrosion kinetics was evaluated by weight loss measurement. The results show that in red soil, the corrosion rate of X70 steel decreases with time, and follows the exponential decay law. General corrosion with non-uniform and localized pitting occurred on the steel surface. α-FeOOH was the dominate products during corrosion in whole buried periods, and the corrosion products exhibited well protective properties. The potentiodynamic polarization tests revealed that icorr decreased with time, indicating the improvement of corrosion resistance. The results of Electrochemical impendence spectroscopy (EIS are consistent with potentiodynamic polarization tests.

  19. Effects of alternating magnetic field on the corrosion rate and corrosion products of copper

    Institute of Scientific and Technical Information of China (English)

    GUO Bin; ZHANG Peng; JIN Yongping; CHENG Shukang

    2008-01-01

    The effects of alternating magnetic field on the corrosion morphologies, corrosion rate, and corrosion products of copper in 3.5% NaCl solution, sea water, and magnetized sea water were investigated using electrochemical test, scanning electron microscopy/energy dispersive analysis system of X-ray (SEM/EDAX), and X-ray diffraction (XRD). The results show that the corrosion rate of copper in magnetized sea water is minimal. Moreover, the surface of the specimen in magnetized sea water is uniform and compact as compared with those in 3.5% NaCl solution and sea water. The corrosion products of copper in magnetized sea water are mainly Cu2O and CuCl2. However, the corrosion products in sea water are CuCl, Cu2Cl(OH)3, and FeCl3·6H2O. The electrochemical corrosion mechanisms of copper in the three media were also discussed.

  20. Corrosivity of paper mill effluent and corrosion performance of stainless steel.

    Science.gov (United States)

    Ram, Chhotu; Sharma, Chhaya; Singh, A K

    2015-01-01

    Present study relates to the corrosivity of paper mill effluent and corrosion performance of stainless steel (SS) as a construction material for the effluent treatment plant (ETP). Accordingly, immersion test and electrochemical polarization tests were performed on SS 304 L, 316 L and duplex 2205 in paper mill effluent and synthetic effluent. This paper presents electrochemical polarization measurements, performed for the first time to the best of the authors' information, to see the influence of chlorophenols on the corrosivity of effluents. The corrosivity of the effluent was observed to increase with the decrease in pH and increase in Cl- content while the addition of SO4- tends to inhibit corrosion. Mill effluent was found to be more corrosive as compared to synthetic effluent and has been attributed to the presence of various chlorophenols. Corrosion performance of SS was observed to govern by the presence of Cr, Mo and N contents.

  1. Review of studies on corrosion of magnesium alloys

    Institute of Scientific and Technical Information of China (English)

    ZENG Rong-chang; ZHANG jin; HUANG Wei-jiu; W. DIETZEL; K. U. KAINER; C. BLAWERT; KE Wei

    2006-01-01

    This review provided some recent progress of the research on corrosion mechanisms of magnesium and its alloys and a basis for follow-on research. Galvanic corrosion,pitting corrosion,intergranular corrosion (IGC),filiform corrosion,crevice corrosion,stress corrosion cracking (SCC),and corrosion fatigue (CF) were discussed. The influence of metallurgical factors such as alloying elements,microstructure and secondary phases,processing factors such as heat treatment and weld,and environmental factors including temperature,relative humidity,solution pH values and concentration on corrosion were discussed. In particular,a mechanism of pitting corrosion caused by AlMn particles was proposed. The corrosion properties of AZ91D weld material were investigated.

  2. Inhibitor treatment program for chlorine dioxide corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Edmondson, J.G.; Holder, E.P.

    1991-11-12

    This patent describes a method of inhibiting corrosion by chlorine dioxide in oil field waterflood systems by adding a sufficient amount of a corrosion inhibiting composition. It comprises a phosphonate, a copolymer consisting of repeating units of acrylic acid/allyl hydroxy propyl sulfonate ether, and a permangante.

  3. Computer-Aided Corrosion Program Management

    Science.gov (United States)

    MacDowell, Louis

    2010-01-01

    This viewgraph presentation reviews Computer-Aided Corrosion Program Management at John F. Kennedy Space Center. The contents include: 1) Corrosion at the Kennedy Space Center (KSC); 2) Requirements and Objectives; 3) Program Description, Background and History; 4) Approach and Implementation; 5) Challenges; 6) Lessons Learned; 7) Successes and Benefits; and 8) Summary and Conclusions.

  4. Aircraft Integral Fuel Tank Corrosion Study

    Science.gov (United States)

    2007-11-02

    biology of Amorphoteca resinae . Materials und Organismen, 6, (3), p. 161, (1971). 8. D. Cabral. Corrosion by microorganisms of jet aircraft integral fuel...the mycelium of the fungus Hormoconis resinae in the MIC of Al alloys. Proc. XI Int. Corrosion Congress, Houston, USA, 5B, p. 3773, (1993). 14. M

  5. Corrosion problems with aqueous coolants, final report

    Energy Technology Data Exchange (ETDEWEB)

    Diegle, R B; Beavers, J A; Clifford, J E

    1980-04-11

    The results of a one year program to characterize corrosion of solar collector alloys in aqueous heat-transfer media are summarized. The program involved a literature review and a laboratory investigation of corrosion in uninhibited solutions. It consisted of three separate tasks, as follows: review of the state-of-the-art of solar collector corrosion processes; study of corrosion in multimetallic systems; and determination of interaction between different waters and chemical antifreeze additives. Task 1 involved a comprehensive review of published literature concerning corrosion under solar collector operating conditions. The reivew also incorporated data from related technologies, specifically, from research performed on automotive cooling systems, cooling towers, and heat exchangers. Task 2 consisted of determining the corrosion behavior of candidate alloys of construction for solar collectors in different types of aqueous coolants containing various concentrations of corrosive ionic species. Task 3 involved measuring the degradation rates of glycol-based heat-transfer media, and also evaluating the effects of degradation on the corrosion behavior of metallic collector materials.

  6. Corrosion effects on soda lime glass

    NARCIS (Netherlands)

    Veer, F.A.; Rodichev, Y.M.

    2010-01-01

    Although soda lime glass is the most common used transparent material in architecture, little is known about the corrosion effects on long term strength and the interaction between corrosion and defects. Extensive testing on soda lime bars under different environmental conditions and different degre

  7. Biobased polymers for corrosion protection of metals

    Science.gov (United States)

    Anticorrosive biobased polymers were developed in our lab. We isolated an exopolysaccharide produced by a microbe that, when coated on metal substrates, exhibited unique corrosion inhibition. Corrosion is a worldwide problem and impacts the economy, jeopardizes human health and safety, and impedes t...

  8. Erosion–corrosion and corrosion properties of DLC coated low temperature Erosion–corrosion and corrosion properties of DLC coated low temperature

    DEFF Research Database (Denmark)

    Jellesen, Morten Stendahl; Christiansen, Thomas; Hilbert, Lisbeth Rischel

    2009-01-01

    of AISI 316 as substrate for DLC coatings are investigated. Corrosion and erosion–corrosion measurements were carried out on low temperature nitrided stainless steel AISI 316 and on low temperature nitrided stainless steel AISI 316 with a top layer of DLC. The combination of DLC and low temperature...

  9. Factors affecting the corrosivity of pulping liquors

    Science.gov (United States)

    Hazlewood, Patrick Evan

    Increased equipment failures and the resultant increase in unplanned downtime as the result of process optimization programs continue to plague pulp mills. The failures are a result of a lack of understanding of corrosion in the different pulping liquors, specifically the parameters responsible for its adjustment such as the role and identification of inorganic and organic species. The current work investigates the role of inorganic species, namely sodium hydroxide and sodium sulfide, on liquor corrosivity at a range of process conditions beyond those currently experienced in literature. The role of sulfur species, in the activation of corrosion and the ability of hydroxide to passivate carbon steel A516-Gr70, is evaluated with gravimetric and electrochemical methods. The impact of wood chip weathering on process corrosion was also evaluated. Results were used to identify black liquor components, depending on the wood species, which play a significant role in the activation and inhibition of corrosion for carbon steel A516-Gr70 process equipment. Further, the effect of black liquor oxidation on liquor corrosivity was evaluated. Corrosion and stress corrosion cracking performance of selected materials provided information on classes of materials that may be reliably used in aggressive pulping environments.

  10. The dual role of microbes in corrosion

    NARCIS (Netherlands)

    Kip, D.J.; Van Veen, J.A.

    2015-01-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced pr

  11. Dissolution properties of cerium dibutylphosphate corrosion inhibitors

    NARCIS (Netherlands)

    Soestbergen, M. van; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

    2013-01-01

    The corrosion inhibitor cerium dibutylphosphate, Ce(dbp)3, prevents corrosion by cerium and dbp deposition at the alkaline cathode and acidic anode respectively. The pH dependent Ce(dbp)3 solubility seems to play an essential role in the inhibition degree. We found that Ce(dbp) 3 scarcely dissolves

  12. EXTRACT OF COMBRETUM MICRANTHUM AS CORROSION ...

    African Journals Online (AJOL)

    user

    2016-10-04

    Oct 4, 2016 ... Aluminum and aluminum alloys lend themselves to many engineering ... Table 1: Elemental composition of the alloy Al-Si-Mg. Element. Si. Mg. Cu. Zn. Al. Composition (wt. ..... microstructure of the control Al- Si- Mg alloy with the lowest C.R in the ... silicate as a corrosion inhibitor for iron and zinc,. Corrosion ...

  13. Vibrational Spectroscopy in Studies of Atmospheric Corrosion

    Directory of Open Access Journals (Sweden)

    Saman Hosseinpour

    2017-04-01

    Full Text Available Vibrational spectroscopy has been successfully used for decades in studies of the atmospheric corrosion processes, mainly to identify the nature of corrosion products but also to quantify their amounts. In this review article, a summary of the main achievements is presented with focus on how the techniques infrared spectroscopy, Raman spectroscopy, and vibrational sum frequency spectroscopy can be used in the field. Several different studies have been discussed where these instruments have been used to assess both the nature of corrosion products as well as the properties of corrosion inhibitors. Some of these techniques offer the valuable possibility to perform in-situ measurements in real time on ongoing corrosion processes, which allows the kinetics of formation of corrosion products to be studied, and also minimizes the risk of changing the surface properties which may occur during ex-situ experiments. Since corrosion processes often occur heterogeneously over a surface, it is of great importance to obtain a deeper knowledge about atmospheric corrosion phenomena on the nano scale, and this review also discusses novel vibrational microscopy techniques allowing spectra to be acquired with a spatial resolution of 20 nm.

  14. Geothermal drill pipe corrosion test plan

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, B.C.; Copass, K.S.

    1980-12-01

    Plans are presented for conducting a field test of drill pipe corrosion, comparing air and nitrogen as drilling fluids. This test will provide data for evaluating the potential of reducing geothermal well drilling costs by extending drill pipe life and reducing corrosion control costs. The 10-day test will take place during fall 1980 at the Baca Location in Sandoval County, New Mexico.

  15. Solutions of corrosion Problems in advanced Technologies

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Karlsson, Asger

    1999-01-01

    were investigated using light optical and scanning electron microscopy. The ferritic steels suffered from corrosion mainly via material loss. The austenitic steels suffered from predominantly selective corrosion resulting in chromium depletion from the alloy. A clear trend was observed that selective...

  16. Corrosion effects on soda lime glass

    NARCIS (Netherlands)

    Veer, F.A.; Rodichev, Y.M.

    2010-01-01

    Although soda lime glass is the most common used transparent material in architecture, little is known about the corrosion effects on long term strength and the interaction between corrosion and defects. Extensive testing on soda lime bars under different environmental conditions and different

  17. Remote computer monitors corrosion protection system

    Energy Technology Data Exchange (ETDEWEB)

    Kendrick, A.

    Effective corrosion protection with electrochemical methods requires some method of routine monitoring that provides reliable data that is free of human error. A test installation of a remote computer control monitoring system for electrochemical corrosion protection is described. The unit can handle up to six channel inputs. Each channel comprises 3 analog signals and 1 digital. The operation of the system is discussed.

  18. Vibrational Spectroscopy in Studies of Atmospheric Corrosion

    Science.gov (United States)

    Hosseinpour, Saman; Johnson, Magnus

    2017-01-01

    Vibrational spectroscopy has been successfully used for decades in studies of the atmospheric corrosion processes, mainly to identify the nature of corrosion products but also to quantify their amounts. In this review article, a summary of the main achievements is presented with focus on how the techniques infrared spectroscopy, Raman spectroscopy, and vibrational sum frequency spectroscopy can be used in the field. Several different studies have been discussed where these instruments have been used to assess both the nature of corrosion products as well as the properties of corrosion inhibitors. Some of these techniques offer the valuable possibility to perform in-situ measurements in real time on ongoing corrosion processes, which allows the kinetics of formation of corrosion products to be studied, and also minimizes the risk of changing the surface properties which may occur during ex-situ experiments. Since corrosion processes often occur heterogeneously over a surface, it is of great importance to obtain a deeper knowledge about atmospheric corrosion phenomena on the nano scale, and this review also discusses novel vibrational microscopy techniques allowing spectra to be acquired with a spatial resolution of 20 nm. PMID:28772781

  19. The dual role of microbes in corrosion

    NARCIS (Netherlands)

    Kip, D.J.; Van Veen, J.A.

    2015-01-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced

  20. Corrosion Behaviour of New Zr Alloys

    DEFF Research Database (Denmark)

    Tolksdorf, E.

    1974-01-01

    Corrosion studies have indicated that the most promising replacements for Zicaloy-2 are ZrCrFe, ZrVFe and probably ZrNbTa, provided they are in their optimized condition. These alloys are conventionally manufactured alloys. An internally oxidized ZrMgO alloy is even superior, from the corrosion...

  1. Electrochemical corrosion measurements on noble electrodeposits

    DEFF Research Database (Denmark)

    Christoffersen, Lasse; Maahn, Ernst Emanuel

    1998-01-01

    Novel electrodeposits are compared with hard chrome and electroless Ni-P with respect to production, corrosion resistance and hardness.......Novel electrodeposits are compared with hard chrome and electroless Ni-P with respect to production, corrosion resistance and hardness....

  2. The Corrosion and Corrosion Fatigue Behavior of Nickel Based Alloy Weld Overlay and Coextruded Claddings

    Science.gov (United States)

    Stockdale, Andrew

    The use of low NOx boilers in coal fired power plants has resulted in sulfidizing corrosive conditions within the boilers and a reduction in the service lifetime of the waterwall tubes. As a solution to this problem, Ni-based weld overlays are used to provide the necessary corrosion resistance however; they are susceptible to corrosion fatigue. There are several metallurgical factors which give rise to corrosion fatigue that are associated with the localized melting and solidification of the weld overlay process. Coextruded coatings offer the potential for improved corrosion fatigue resistance since coextrusion is a solid state coating process. The corrosion and corrosion fatigue behavior of alloy 622 weld overlays and coextruded claddings was investigated using a Gleeble thermo-mechanical simulator retrofitted with a retort. The experiments were conducted at a constant temperature of 600°C using a simulated combustion gas of N2-10%CO-5%CO2-0.12%H 2S. An alternating stress profile was used with a minimum tensile stress of 0 MPa and a maximum tensile stress of 300 MPa (ten minute fatigue cycles). The results have demonstrated that the Gleeble can be used to successfully simulate the known corrosion fatigue cracking mechanism of Ni-based weld overlays in service. Multilayer corrosion scales developed on each of the claddings that consisted of inner and outer corrosion layers. The scales formed by the outward diffusion of cations and the inward diffusion of sulfur and oxygen anions. The corrosion fatigue behavior was influenced by the surface finish and the crack interactions. The initiation of a large number of corrosion fatigue cracks was not necessarily detrimental to the corrosion fatigue resistance. Finally, the as-received coextruded cladding exhibited the best corrosion fatigue resistance.

  3. General Corrosion and Localized Corrosion of the Drip Shield

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua; K. Mon

    2003-06-24

    The recommended waste package (WP) design is described in BSC (2001a). The design includes a double-wall WP underneath a protective drip shield (DS) (BSC 2003a). The purpose of the process-level models developed in this report is to model dry oxidation (DOX), general corrosion (GC) and localized corrosion (LC) of the DS plate material, which is made of Ti Grade 7. The DS design also includes structural supports fabricated from Ti Grade 24. Degradation of Ti Grade 24 is not considered in this report. The DS provides protection for the waste package outer barrier (WPOB) both as a barrier to seepage water contact and a physical barrier to potential rockfall. This Model Report (MR) serves as a feed to the Integrated Waste Package Degradation Model (IWPD) analyses, and was developed in accordance with the Technical Work Plan (TWP) (BSC 2002a). The models contained in this report serve as a basis to determine whether or not the performance requirements for the DS can be met.

  4. Steam generator corrosion 2007; Dampferzeugerkorrosion 2007

    Energy Technology Data Exchange (ETDEWEB)

    Born, M. (ed.)

    2007-07-01

    Between 8th and 9th November, 2007, SAXONIA Standortentwicklungs- und -verwertungsgesellschaft GmbH (Freiberg, Federal Republic of Germany) performed the 3rd Freiberger discussion conference ''Fireside boiler corrosion''. The topics of the lectures are: (a) Steam generator corrosion - an infinite history (Franz W. Alvert); (b) CFD computations for thermal waste treatment plants - a contribution for the damage recognition and remedy (Klaus Goerner, Thomas Klasen); (c) Experiences with the use of corrosion probes (Siegfried R. Horn, Ferdinand Haider, Barbara Waldmann, Ragnar Warnecke); (d) Use of additives for the limitation of the high temperature chlorine corrosion as an option apart from other measures to the corrosion protection (Wolfgang Spiegel); (e) Current research results and aims of research with respect to chlorine corrosion (Ragnar Warnecke); (f) Systematics of the corrosion phenomena - notes for the enterprise and corrosion protection (Thomas Herzog, Wolfgang Spiegel, Werner Schmidl); (g) Corrosion protection by cladding in steam generators of waste incinerators (Joerg Metschke); (h) Corrosion protection and wear protection by means of thermal spraying in steam generators (Dietmar Bendix); (i) Review of thick film nickelized components as an effective protection against high-temperature corrosion (Johann-Wilhelm Ansey); (j) Fireproof materials for waste incinerators - characteristics and profile of requirement (Johannes Imle); (k) Service life-relevant aspects of fireproof linings in the thermal recycling of waste (Till Osthoevener and Wolfgang Kollenberg); (l) Alternatives to the fireproof material in the heating space (Heino Sinn); (m) Cladding: Inconal 625 contra 686 - Fundamentals / applications in boiler construction and plant construction (Wolfgang Hoffmeister); (n) Thin films as efficient corrosion barriers - thermal spray coating in waste incinerators and biomass firing (Ruediger W. Schuelein, Steffen Hoehne, Friedrich

  5. Launch Pad Coatings for Smart Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Bucherl, Cori N.; Li, Wenyan; Buhrow, Jerry W.; Curran, Jerome P.; Whitten, Mary C.

    2010-01-01

    Corrosion is the degradation of a material as a result of its interaction with the environment. The environment at the KSC launch pads has been documented by ASM International (formerly American Society for Metals) as the most corrosive in the US. The 70 tons of highly corrosive hydrochloric acid that are generated by the solid rocket boosters during a launch exacerbate the corrosiveness of the environment at the pads. Numerous failures at the pads are caused by the pitting of stainless steels, rebar corrosion, and the degradation of concrete. Corrosion control of launch pad structures relies on the use of coatings selected from the qualified products list (QPL) of the NASA Standard 5008A for Protective Coating of Carbon Steel, Stainless Steel, and Aluminum on Launch Structures, Facilities, and Ground Support Equipment. This standard was developed to establish uniform engineering practices and methods and to ensure the inclusion of essential criteria in the coating of ground support equipment (GSE) and facilities used by or for NASA. This standard is applicable to GSE and facilities that support space vehicle or payload programs or projects and to critical facilities at all NASA locations worldwide. Environmental regulation changes have dramatically reduced the production, handling, use, and availability of conventional protective coatings for application to KSC launch structures and ground support equipment. Current attrition rate of qualified KSC coatings will drastically limit the number of commercial off the shelf (COTS) products available for the Constellation Program (CxP) ground operations (GO). CxP GO identified corrosion detection and control technologies as a critical, initial capability technology need for ground processing of Ares I and Ares V to meet Constellation Architecture Requirements Document (CARD) CxP 70000 operability requirements for reduced ground processing complexity, streamlined integrated testing, and operations phase affordability

  6. The effects of sous-vide cooking parameters on texture and cell wall modifications in two apple cultivars: A response surface methodology approach.

    Science.gov (United States)

    Ortiz, Abel; Le Meurlay, Dominique; Lara, Isabel; Symoneaux, Ronan; Madieta, Emmanuel; Mehinagic, Emira

    2017-03-01

    This work aimed at evaluating the effects of sous-vide cooking parameters, such as time and temperature and their interactions, on textural attributes of 'Mondial Gala' and 'Granny Smith' apple cultivars. For this, different response surface methodology-based models were developed. This methodology proved a suitable means for the assessment of changes in textural parameters and cell wall modifications during the processing of apples. 'Mondial Gala' fruit displayed better aptitude for the preservation of textural properties after high-temperature processing conditions and were therefore apparently more suited to sous-vide cooking than 'Granny Smith' apples. Pectin methylesterase activity levels in 'Mondial Gala' apples were enhanced at mild temperatures and pectins in this cultivar displayed a lower degree of methylation. Therefore, the establishment of calcium-mediated linkages between cell wall polymers might have been favoured in 'Mondial Gala' apples, thus reinforcing tissues and improving the preservation of textural attributes, in comparison to 'Granny Smith' samples.

  7. Stifling of Crevice Corrosion in Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Mon, K G; Gordon, G M; Rebak, R B

    2005-06-08

    Artificially creviced Alloy 22 (N06022) specimens may be susceptible to crevice corrosion in presence of hot chloride containing solutions. The presence of oxyanions in the electrolyte, especially nitrate, may inhibit the nucleation and growth of crevice corrosion. Constant potential tests were performed using tightly creviced specimens of Alloy 22. It was found that crevice corrosion may initiate when a constant potential above the crevice repassivation potential is applied. It was found that as the crevice corrosion nucleated, the current initially increased but later decreased. The net measured current can be converted into penetration following a power law fit of the experimental data. The average power law coefficient ''n'' was found to be 0.439, suggesting that even under constant applied potential crevice corrosion penetration is diffusion controlled.

  8. STIFLING OF CREVICE CORROSION IN ALLOY 22

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon; G.M. Gordon; R.B. Rebak

    2005-07-01

    Artificially creviced Alloy 22 (N06022) specimens may be susceptible to crevice corrosion in presence of hot chloride containing solutions. The presence of oxyanions in the electrolyte, especially nitrate, may inhibit the nucleation and growth of crevice corrosion. Constant potential tests were performed using tightly creviced specimens of Alloy 22. It was found that crevice corrosion may initiate when a constant potential above the crevice repassivation potential is applied. It was found that as the crevice corrosion nucleated, the current initially increased but later decreased. The net measured current can be converted into penetration following a power law fit of the experimental data. The average power law coefficient ''n'' was found to be 0.439, suggesting that even under constant applied potential, crevice corrosion penetration is diffusion controlled.

  9. Microencapsulation Technologies for Corrosion Protective Coating Applications

    Science.gov (United States)

    Li, Wenyan; Buhrow, Jerry; Jolley, Scott; Calle, Luz; Pearman, Benjamin; Zhang, Xuejun

    2015-01-01

    Microencapsulation technologies for functional smart Coatings for autonomous corrosion control have been a research area of strong emphasis during the last decade. This work concerns the development of pH sensitive micro-containers (microparticles and microcapsules) for autonomous corrosion control. This paper presents an overview of the state-of-the-art in the field of microencapsulation for corrosion control applications, as well as the technical details of the pH sensitive microcontainer approach, such as selection criteria for corrosion indicators and corrosion inhibitors; the development and optimization of encapsulation methods; function evaluation before and after incorporation of the microcontainers into coatings; and further optimization to improve coating compatibility and performance.

  10. Corrosion of carbon-alloyed iron aluminides

    Indian Academy of Sciences (India)

    M Sen; R Balasubramaniam; A V Ramesh Kumar

    2000-10-01

    The corrosion behaviour of two carbon-alloyed intermetallics of composition Fe–28.1Al–2.1C and Fe–27.5Al–3.7C has been studied and compared with that of binary intermetallics. Potentiodynamic polarization studies indicated that the intermetallics exhibited active–passive behaviour in an acidic solution of pH = 1, whereas they exhibited stable passivity in a buffer solution of pH 8.4. Corrosion rates were also obtained by immersion testing. The variation of corrosion rate as a function of time was similar for both the intermetallics. The variation in corrosion rate as a function of time has been explained based on the observed potentiodynamic polarization behaviour. Scanning electron microscopy of corroded surfaces indicated that the carbon-alloyed intermetallics were susceptible to galvanic corrosion, due to the presence of carbides.

  11. Laser-controllable coatings for corrosion protection.

    Science.gov (United States)

    Skorb, Ekaterina V; Skirtach, Andre G; Sviridov, Dmitry V; Shchukin, Dmitry G; Möhwald, Helmuth

    2009-07-28

    We introduce a novel and versatile approach to the corrosion protection by use of "smart" laser-controllable coating. The main advantage of the proposed technique is that one could terminate the corrosion process by very intensive healing after an appearance of corrosion centers using local laser irradiation. It is also shown that by applying a polyelectrolyte shell with noble metal particles over the mesoporous titania and silica via layer-by-layer assembly it is possible to fabricate micro- and nanoscaled reservoirs, which, being incorporated into the zirconia-organosilica matrix, are responsible for the ability of laser-driven release of the loaded materials (e.g., corrosion inhibitor). Furthermore, the resultant films are highly adhesive and could be easily deposited onto different metallic substrates. Laser-mediated remote release of incorporated corrosion inhibitor (benzotriazole) from engineered mesoporous containers with silver nanoparticles in the container shell is observed in real time on single and multicontainer levels.

  12. Modeling of Corrosion-induced Concrete Damage

    DEFF Research Database (Denmark)

    Thybo, Anna Emilie A.; Michel, Alexander; Stang, Henrik

    2013-01-01

    In the present paper a finite element model is introduced to simulate corrosion-induced damage in concrete. The model takes into account the penetration of corrosion products into the concrete as well as non-uniform formation of corrosion products around the reinforcement. To ac-count for the non......-uniform formation of corrosion products at the concrete/reinforcement interface, a deterministic approach is used. The model gives good estimates of both deformations in the con-crete/reinforcement interface and crack width when compared to experimental data. Further, it is shown that non-uniform deposition...... of corrosion products affects both the time-to cover cracking and the crack width at the concrete surface....

  13. Fuel corrosion processes under waste disposal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shoesmith, D.W. [Univ. of Western Ontario, Dept. of Chemistry, London, Ontario (Canada)

    1999-09-01

    Under the oxidizing conditions likely to be encountered in the Yucca Mountain Repository, fuel dissolution is a corrosion process involving the coupling of the anodic dissolution of the fuel with the cathodic reduction of oxidants available within the repository. The oxidants potentially available to drive fuel corrosion are environmental oxygen, supplied by the transport through the permeable rock of the mountain and molecular and radical species produced by the radiolysis of available aerated water. The mechanism of these coupled anodic and cathodic reactions is reviewed in detail. While gaps in understanding remain, many kinetic features of these reactions have been studied in considerable detail, and a reasonably justified mechanism for fuel corrosion is available. The corrosion rate is determined primarily by environmental factors rather than the properties of the fuel. Thus, with the exception of increase in rate due to an increase in surface area, pre-oxidation of the fuel has little effect on the corrosion rate.

  14. Passive Corrosion Behavior of Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, R B; Payer, J H

    2006-01-10

    Alloy 22 (N06022) was designed to stand the most aggressive industrial applications, including both reducing and oxidizing acids. Even in the most aggressive environments, if the temperature is lower than 150 F (66 C) Alloy 22 would remain in the passive state having particularly low corrosion rates. In multi-ionic solutions that may simulate the behavior of concentrated ground water, even at near boiling temperatures, the corrosion rate of Alloy 22 is only a few nanometers per year because the alloy is in the complete passive state. The corrosion rate of passive Alloy 22 decreases as the time increases. Immersion corrosion testing also show that the newer generation of Ni-Cr-Mo alloys may offer a better corrosion resistance than Alloy 22 only in some highly aggressive conditions such as in hot acids.

  15. Complete corrosion inhibition through graphene defect passivation.

    Science.gov (United States)

    Hsieh, Ya-Ping; Hofmann, Mario; Chang, Kai-Wen; Jhu, Jian Gang; Li, Yuan-Yao; Chen, Kuang Yao; Yang, Chang Chung; Chang, Wen-Sheng; Chen, Li-Chyong

    2014-01-28

    Graphene is expected to enable superior corrosion protection due to its impermeability and chemical inertness. Previous reports, however, demonstrate limited corrosion inhibition and even corrosion enhancement of graphene on metal surfaces. To enable the reliable and complete passivation, the origin of the low inhibition efficiency of graphene was investigated. Combining electrochemical and morphological characterization techniques, nanometer-sized structural defects in chemical vapor deposition grown graphene were found to be the cause for the limited passivation effect. Extremely fast mass transport on the order of meters per second both across and parallel to graphene layers results in an inhibition efficiency of only ∼50% for Cu covered with up to three graphene layers. Through selective passivation of the defects by atomic layer deposition (ALD) an enhanced corrosion protection of more than 99% was achieved, which compares favorably with commercial corrosion protection methods.

  16. Inhibition of aluminum corrosion using Opuntia extract

    Energy Technology Data Exchange (ETDEWEB)

    El-Etre, A.Y

    2003-11-01

    The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions.

  17. Passive Corrosion Behavior of Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    R.B. Rebak; J.H. Payer

    2006-01-20

    Alloy 22 (NO6022) was designed to stand the most aggressive industrial applications, including both reducing and oxidizing acids. Even in the most aggressive environments, if the temperature is lower than 150 F (66 C) Alloy 22 would remain in the passive state having particularly low corrosion rates. In multi-ionic solutions that may simulate the behavior of concentrated ground water, even at near boiling temperatures, the corrosion rate of Alloy 22 is only a few nano-meters per year because the alloy is in the complete passive state. The corrosion rate of passive Alloy 22 decreases as the time increases. Immersion corrosion testing also show that the newer generation of Ni-Cr-Mo alloys may offer a better corrosion resistance than Alloy 22 only in some highly aggressive conditions such as in hot acids.

  18. Numerical Study of Corrosion Crack Opening

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Frandsen, Henrik Lund; Svensson, Staffan

    2008-01-01

    for the corrosion crack opening. Experiments and theoretical analysis by a numerical method, FEM, support that the relation between the reduction of the reinforcement bar diameter due to corrosion and the corresponding increase in crack width for a given time interval, measured on the surface of a concrete specimen...... is proportional. More recently, the constant of proportionality, the so-called crack-corrosion index, has been studied further with respect to its dependence on the diameter of the reinforcement and the concrete cover. In the present paper the above-mentioned work is presented and extended with more realistic 3D......-models of the cracked concrete beam. The crack-corrosion index is evaluated for a variation of different parameters, i.e. bar diameter, concrete cover, crack length and type of corrosion product. This paper is an extended version of a paper by Thoft-Christensen et al. (2005) presented at the IFIP WG 7.5 Conference...

  19. Corrosion protection with eco-friendly inhibitors

    Science.gov (United States)

    Shahid, Muhammad

    2011-12-01

    Corrosion occurs as a result of the interaction of a metal with its environment. The extent of corrosion depends on the type of metal, the existing conditions in the environment and the type of aggressive ions present in the medium. For example, CO3-2 and NO-3 produce an insoluble deposit on the surface of iron, resulting in the isolation of metal and consequent decrease of corrosion. On the other hand, halide ions are adsorbed selectively on the metal surface and prevent formation of the oxide phase on the metal surface, resulting in continuous corrosion. Iron, aluminum and their alloys are widely used, both domestically and industrially. Linear alkylbenzene and linear alkylbenzene sulfonate are commonly used as detergents. They have also been found together in waste water. It is claimed that these chemicals act as inhibitors for stainless steel and aluminum. Release of toxic gases as a result of corrosion in pipelines may lead in certain cases to air pollution and possible health hazards. Therefore, there are two ways to look at the relationship between corrosion and pollution: (i) corrosion of metals and alloys due to environmental pollution and (ii) environmental pollution as a result of corrosion protection. This paper encompasses the two scenarios and possible remedies for various cases, using 'green' inhibitors obtained either from plant extracts or from pharmaceutical compounds. In the present study, the effect of piperacillin sodium as a corrosion inhibitor for mild steel was investigated using a weight-loss method as well as a three-electrode dc electrochemical technique. It was found that the corrosion rate decreased as the concentration of the inhibitor increased up to 9×10-4 M 93% efficiency was exhibited at this concentration.

  20. Factors influencing resuscitation and growth of heat injured Listeria monocytogenes 13-249 in sous vide cooked beef.

    Science.gov (United States)

    Hansen, T B; Knøchel, S

    2001-01-22

    The growth of Listeria monocytogenes 13-249 in vacuum-packed, minced beef was investigated as a function of degree of heat injury (including no injury i.e. uncooked beef), growth phase (logarithmic and late stationary phase), pH (5.6 and 6.2), and storage temperature (3, 10 and 20 degrees C) during a storage period of 30 days. Late logarithmic and late stationary phase cultures of L. monocytogenes 13-249 showed similar growth in refrigerated, vacuum-packed, raw minced beef with a high pH (6.2). In normal pH (5.6) beef there was no growth at 3 degrees C while growth at 10 and 20 degrees C was only observed for logarithmic phase cultures. Heat injured late stationary phase cultures with 95-99.9% injured cells in the surviving population (as measured by differential plating on enriched vs. selective media after sous vide cooking) did not grow or repair sublethal injuries in sous vide cooked beef at 3 degrees C while repair and growth took place at 10 as well as at 20 degrees C. In logarithmic phase cultures heat injury occurred very rapidly and > or = 99.9% heat injury was observed in all trials in spite of much lower pasteurization values and fewer log10 reductions compared with late stationary phase cultures. Regardless of growth phase, all cultures where a high degree of heat injury (> or = 99.9%) was observed, did not subsequently grow in the beef product at 3 or 10 degrees C within 30 days. Growth of heat injured cultures preexposed to heat shock (46 degrees C, 30 min) or slowly rising temperatures (0.3 degrees C min(-1)) before heat injury was also investigated. Heat shocked or heat adapted cultures generally responded in the same manner as non-stressed cultures (no growth at 3 degrees C) except that a longer lag phase was observed in beef processed at slowly rising temperatures and in normal pH beef at 10 degrees C. Although processing at slowly rising temperatures may slightly increase the survival of L. monocytogenes 13-249 in cooked beef, there seem to be no

  1. Microbial, physical-chemical and sensory spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method.

    Science.gov (United States)

    Díaz, Pedro; Nieto, Gema; Garrido, María Dolores; Bañón, Sancho

    2008-10-01

    The aim was to study spoilage during the refrigerated storage of cooked pork loin processed by the sous vide method. Samples were packaged under vacuum into polyamide-polypropylene pouches, cooked at an oven temperature/time of 70°C/12h, chilled at 3°C and stored at 2°C for 0, 5 or 10 weeks. Microbial (psychrotrophs, lactic acid bacteria, Enterobacteriaceae, moulds and yeasts), physical-chemical (pH, water activity, TBARS, acidity, L(∗)a(∗)b(∗) colour, texture profile analysis and shear force) and sensory (appearance, odour, flavour, texture and acceptance) parameters were determined. The results showed that sensory spoilage preceded microbiological spoilage of sous vide pork loin. Counts bellow 1logcfu/g of psychrotrophs, anaerobic psychrotrophs, Enterobacteriaceae and lactic acid bacteria were detected in any control week, while moderate counts (2-3logcfu/g) of moulds and yeasts were found. Minor changes in water activity, lipid oxidation, CIELab colour, hardness, cohesiveness or gumminess were associated with spoilage of pork loin, only decreases of lactic acid, springiness and shear force were observed. The pork loin was unacceptable after 10 weeks. This loss of acceptance was mainly due to the deterioration of meaty flavour and odour, although the loss of appearance, juiciness and firmness also contributed. Moderate warmed-over and rancidity were detected. The sensory analysis was the most effective method for determining the shelf life of the sous vide pork-based dishes.

  2. Microbial corrosion of aluminum alloy.

    Science.gov (United States)

    Yang, S S; Chen, C Y; Wei, C B; Lin, Y T

    1996-11-01

    Several microbes were isolated from the contaminated fuel-oil in Taiwan and the microbial corrosion of aluminum alloy A356-T6 was tested by MIL-STD-810E test method. Penicillium sp. AM-F5 and Cladosporium resinac ATCC 22712 had significant adsorption and pitting on the surface of aluminum alloy, Pseudomonas acruginosa AM-B5 had weak adsorption and some precipitation in the bottom, and Candida sp. AM-Y1 had the less adsorption and few cavities formation on the surface. pH of the aqueous phase decreased 0.3 to 0.7 unit for 4 months of incubation. The corrosion of aluminum alloy was very significant in the cultures of Penicillium sp. AM-F2, Penicillium sp. AM-F5 and C. resinac ATCC 22712. The major metabolites in the aqueous phase with the inoculation of C. resinac were citric acid and oxalic acid, while succinic acid and fumaric acid were the minors.

  3. Migrating corrosion inhibitor blend for reinforced concrete: Part 1 -- Prevention of corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, B.; Buechler, M.; Stalder, F.; Boehni, H.

    1999-12-01

    The efficiency of a migrating corrosion inhibitor in preventing corrosion of mild steel was investigated in saturated calcium hydroxide (Ca[OH]{sub 2}) solutions and in mortar. The protective effect of the inhibitor against pitting corrosion caused by chloride attack and against uniform corrosion as a result of carbonation was determined. Results showed that high concentrations ({approx}10%) allowed the inhibition of pitting corrosion tritiation in solution containing 1 M/L sodium chloride (NaCl). However, inhibiting properties can be lost by evaporation of the volatile constituent of the inhibitor or by the precipitation of the nonvolatile fraction of the inhibitor in presence of calcium ions. Addition of the inhibitor blend to mortar yielded a retardation of the corrosion initiation in the case of chloride-induced corrosion, but o significant reduction in corrosion rate. No effect was found in carbonated samples, and no influence on the corrosion rate was detected. Additionally, the estimation of the extent of the retarding effect on corrosion initiation on real structures was difficult, as the inhibitor was found to evaporate from the mortar. This evaporation resulted in a loss of inhibiting properties. Hence, the long-term efficiency of the inhibitor could not be guaranteed.

  4. Atmospheric Corrosivity at Australian and Overseas Airbases and Airports

    Science.gov (United States)

    2014-07-01

    protective coating systems and corrosion inhibitor treatments deteriorate and become less effective. The CLIMAT environmental corrosion test has...UNCLASSIFIED UNCLASSIFIED Atmospheric Corrosivity at Australian and Overseas Airbases and Airports J C Bitcon Maritime...Division Defence Science and Technology Organisation DSTO-TN-1320 ABSTRACT Atmospheric corrosivity at 25 airbases and airports in Australia

  5. 49 CFR 193.2631 - Internal corrosion control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control. 193.2631 Section 193... GAS FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2631 Internal corrosion control. Each component that is subject to internal corrosive attack must be protected from internal corrosion by—...

  6. 49 CFR 192.475 - Internal corrosion control: General.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control: General. 192.475... Control § 192.475 Internal corrosion control: General. (a) Corrosive gas may not be transported by... taken to minimize internal corrosion. (b) Whenever any pipe is removed from a pipeline for any...

  7. 46 CFR 154.412 - Cargo tank corrosion allowance.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo tank corrosion allowance. 154.412 Section 154.412... Containment Systems § 154.412 Cargo tank corrosion allowance. A cargo tank must be designed with a corrosion...) carries a cargo that corrodes the tank material. Note: Corrosion allowance for independent tank type C...

  8. 49 CFR 193.2627 - Atmospheric corrosion control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Atmospheric corrosion control. 193.2627 Section... LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2627 Atmospheric corrosion... atmospheric corrosion by— (a) Material that has been designed and selected to resist the corrosive...

  9. Corrosion damage evolution and residual strength of corroded aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Youhong Zhang; Guozhi Lv; Hui Wang; Bomei Si; Yueliang Cheng

    2008-01-01

    The LY12CZ aluminum alloy specimens were eurroded under the conditions of different test temperatures and exposure durations. After corrosion exposure, fatigue tests were performed. Scanning electron microscopy and optical microscope analyses on corrosion damage were carried out. The definition of surface corrosion damage ratio was provided to describe the extent of surface corrosion damage. On the basis of the measured data sets of the corrosion damage ratio, the probabilistic model of corrosion damage evolution was built. The corrosion damage decreased the fatigue life by a factor of about 1.25 to 2.38 and the prediction method of residual strength of the corroded structure was presented.

  10. A Calculation Model for Corrosion Cracking in RC Structures

    Institute of Scientific and Technical Information of China (English)

    Xu Gang; Wei Jun; Zhang Keqiang; Zhou Xiwu

    2007-01-01

    A novel calculation model is proposed aiming at the problem of concrete cover cracking induced by reinforcement corrosion. In this article, the relationship between the corrosion depth of the bar and the thickness of the rust layer is established. By deducing the radial displacement expression of concrete, the formula for corrosion depth and corrosion pressure before cracking is proposed. The crack depth of cover in accordance with the maximum corrosion pressure is deduced; furthermore, the corrosion depth and corrosion pressure at the cracking time are obtained. Finally, the theoretical model is validated by several experiments, and the calculated values agree well with the experiment results.

  11. Corrosion inhibitors for intermediate cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Falk, I.; Suhr, L.

    1985-04-01

    The selected inhibitors were tested for heat and radiation stability and corrosion protection on the bench scale. Based on the results from these tests two of the products were selected, Bycoguard 81 and Bycoguard MP4S for continuing corrosion tests in an autoclave loop at 90 degrees C and 120 degrees C. Oxygen saturated deionized water with an addition of 1 ppm chloride was recirculated in the loop. Samples of copper and carbon steel were exposed to the water in the autoclave for periods up to 10 weeks. The purpose of this project was to find a substitute for hydrazine and chromates. Besides good corrosion protection qualities the toxic and environmental effect of the inhibitors should be minimal. The investigation has shown that the copper inhibitor BTA (benzotriazole) loses its corrosion protection qualities at a water temperature of 120 degrees C. The protection effects at 90 degrees C were satisfactory for both of the materials. The corrosion rates measured were 0.01 mm/y or less for the copper and carbon steel samples. The environment in the autoclave during the testing was more corrosive than is to be found in intermediate cooling systems. Due to the low corrosion rates measured the two inhibitors are to be recommended as alternatives to hydrazine and chromates.

  12. Mesoporous silica nanoparticles for active corrosion protection.

    Science.gov (United States)

    Borisova, Dimitriya; Möhwald, Helmuth; Shchukin, Dmitry G

    2011-03-22

    This work presents the synthesis of monodisperse, mesoporous silica nanoparticles and their application as nanocontainers loaded with corrosion inhibitor (1H-benzotriazole (BTA)) and embedded in hybrid SiOx/ZrOx sol-gel coating for the corrosion protection of aluminum alloy. The developed porous system of mechanically stable silica nanoparticles exhibits high surface area (∼1000 m2·g(-1)), narrow pore size distribution (d∼3 nm), and large pore volume (∼1 mL·g(-1)). As a result, a sufficiently high uptake and storage of the corrosion inhibitor in the mesoporous nanocontainers was achieved. The successful embedding and homogeneous distribution of the BTA-loaded monodisperse silica nanocontainers in the passive anticorrosive SiOx/ZrOx film improve the wet corrosion resistance of the aluminum alloy AA2024 in 0.1 M sodium chloride solution. The enhanced corrosion protection of this newly developed active system in comparison to the passive sol-gel coating was observed during a simulated corrosion process by the scanning vibrating electrode technique (SVET). These results, as well as the controlled pH-dependent release of BTA from the mesoporous silica nanocontainers without additional polyelectrolyte shell, suggest an inhibitor release triggered by the corrosion process leading to a self-healing effect.

  13. Marine atmospheric corrosion of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Morcillo, M.; Alcantara, J.; Diaz, I.; Chico, B.; Simancas, J.; Fuente, D. de la

    2015-07-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  14. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    Directory of Open Access Journals (Sweden)

    Marko Chigondo

    2016-01-01

    Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

  15. Studies and support for the EGS reservoirs at Soultz-sous-Forets. April 2004 - May 2009. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Portier, S.; Vuataz, F.-D. [Centre de Recherche en Geothermie (CREGE), Neuchatel (Switzerland)

    2009-08-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at the activities carried out during the period from April 2004 up to May 2009 at Soultz-sous-Forets, France, in connection with the enhanced geothermal systems (EGS) at that location. The report describes the work performed by the Swiss EGS Research and Development group involved in the Soultz project. The principal target set was to install and operate a power plant, enabling the deep reservoir/heat exchanger to be operated, evaluated and improved under realistic conditions. The Swiss contributors have been participating in several work packages: Short and long term tests and medium-term tests of the three-well reservoir/heat exchanger system, development and up-scaling, technical and economic design of larger, industrial, EGS units and the development of stimulation methodology for EGS. The exchange of findings obtained during this project phase is discussed, as is the state-of-the-art of EGS stimulation methods, the interpretation of logging data. Also, seismic /-hydraulic factors, the evaluation of the production/injection performance of the boreholes and reservoir development strategies are discussed as are the modelling of geochemical impact of forced fluid circulation in the deep geothermal reservoir and the results of chemical stimulation tests performed on site.

  16. Efficacy of Combined Sous Vide-Microwave Cooking for Foodborne Pathogen Inactivation in Ready-to-Eat Chicory Stems.

    Science.gov (United States)

    Renna, Massimiliano; Gonnella, Maria; de Candia, Silvia; Serio, Francesco; Baruzzi, Federico

    2017-07-01

    There is a variety of different food processing methods, which can be used to prepare ready-to-eat foods. However, the need to preserve the freshness and nutritional qualities leads to the application of mild technologies which may be insufficient to inactivate microbial pathogens. In this work, fresh chicory stems were packed under a vacuum in films, which were transparent to microwaves. These were then exposed to microwaves for different periods of time. The application of sous vide microwave cooking (SV-MW, 900 W, 2450 MHz), controlled naturally occurring mesophilic aerobic bacteria, yeasts and molds for up to 30 d when vacuum-packed vegetables were stored at 4 °C. In addition, the process lethality of the SV-MW 90 s cooking was experimentally validated. This treatment led to 6.07 ± 0.7 and 4.92 ± 0.65 log cfu/g reduction of Escherichia coli and Listeria monocytogenes inoculated over the chicory stems (100 g), respectively. With an initial load of 9 log cfu/g for both pathogens, less than 10 cfu/g of surviving cells were found after 90 s cooking. This shows that short-time microwave cooking can be used to effectively pasteurize vacuum-packed chicory stems, achieving >5 log cfu/g reduction of E. coli and L. monocytogenes. © 2017 Institute of Food Technologists®.

  17. Principles and Application of Sous-vide%真空恒温烹饪技术原理及应用

    Institute of Scientific and Technical Information of China (English)

    陈龙; 乔兴

    2012-01-01

    真空恒温烹饪技术是从烹饪原料的分子层面入手,通过使用相对低气压、蛋白质变性温度点控制等理化及生化手段,运用现代烹饪仪器和设备制作出新式菜肴的烹饪方法。掌握真空恒温烹饪的技术原理,对应用于意境菜肴创作以及传统菜肴技术改良具有现实意义。%Sous-vide is a method of cooking which can be used to create new dishes with the help of modem cooking apparatuses and equipments as it applies such techniques as relatively low pressure and protein denaturation control to preserve intact molecules in cooking materials. This technique is of practical significance in creating artistic cuisine and improving traditional dishes as well.

  18. Novel Corrosion Sensor for Vision 21 Systems

    Energy Technology Data Exchange (ETDEWEB)

    Heng Ban

    2005-12-01

    Advanced sensor technology is identified as a key component for advanced power systems for future energy plants that would have virtually no environmental impact. This project intends to develop a novel high temperature corrosion sensor and subsequent measurement system for advanced power systems. Fireside corrosion is the metal loss caused by chemical reactions on surfaces exposed to the combustion environment. Such corrosion is the leading mechanism for boiler tube failures and has emerged to be a significant concern for current and future energy plants due to the introduction of technologies targeting emissions reduction, efficiency improvement, or fuel/oxidant flexibility. Corrosion damage can lead to catastrophic equipment failure, explosions, and forced outages. Proper management of corrosion requires real-time indication of corrosion rate. However, short-term, on-line corrosion monitoring systems for fireside corrosion remain a technical challenge to date due to the extremely harsh combustion environment. The overall objective of this project is to develop a technology for on-line corrosion monitoring based on a new concept. This objective is to be achieved by a laboratory development of the sensor and instrumentation, testing of the measurement system in a laboratory muffle furnace, and eventually testing the system in a coal-fired furnace. The initial plan for testing at the coal-fired pilot-scale furnace was replaced by testing in a power plant, because the operation condition at the power plant is continuous and more stable. The first two-year effort was completed with the successful development sensor and measurement system, and successful testing in a muffle furnace. Because of the potential high cost in sensor fabrication, a different type of sensor was used and tested in a power plant burning eastern bituminous coals. This report summarize the experiences and results of the first two years of the three-year project, which include laboratory

  19. Slurry Chemical Corrosion and Galvanic Corrosion during Copper Chemical Mechanical Polishing

    Science.gov (United States)

    Kondo, Seiichi; Sakuma, Noriyuki; Homma, Yoshio; Ohashi, Naofumi

    2000-11-01

    Copper (Cu) corrosion during chemical mechanical polishing (CMP) was controlled in order to improve the Cu damascene interconnect process. Slurry chemical corrosion was found to be enhanced when the slurry was diluted by deionized (DI) water during rinsing just after CMP@. Since the corrosion inhibitor, benzotriazole (BTA), reduces the Cu removal rate, adding it to the rinse solution prevents chemical corrosion more effectively than adding it to the slurry. On the other hand, galvanic corrosion occurs at the interface between Cu and the barrier metal, and it can be prevented by selecting appropriate barrier metals. Because the difference between the electrochemical potentials of Cu and the barrier metal is small in the slurry, refractory metals such as Ta, TaN, and TiN were found to be appropriate barrier metals. On the other hand, W, WN, and Ti have large potential differences, so galvanic corrosion was clearly observed when Cu/W damascene interconnects were fabricated.

  20. A STUDY OF CORROSION AND STRESS CORROSION CRACKING OF CARBON STEEL NUCLEAR WASTE STORAGE TANKS

    Energy Technology Data Exchange (ETDEWEB)

    BOOMER, K.D.

    2007-08-21

    The Hanford reservation Tank Farms in Washington State has 177 underground storage tanks that contain approximately 50 million gallons of liquid legacy radioactive waste from cold war plutonium production. These tanks will continue to store waste until it is treated and disposed. These nuclear wastes were converted to highly alkaline pH wastes to protect the carbon steel storage tanks from corrosion. However, the carbon steel is still susceptible to localized corrosion and stress corrosion cracking. The waste chemistry varies from tank to tank, and contains various combinations of hydroxide, nitrate, nitrite, chloride, carbonate, aluminate and other species. The effect of each of these species and any synergistic effects on localized corrosion and stress corrosion cracking of carbon steel have been investigated with electrochemical polarization, slow strain rate, and crack growth rate testing. The effect of solution chemistry, pH, temperature and applied potential are all considered and their role in the corrosion behavior will be discussed.

  1. Waste of cleaning emulsion sewage as inhibitors of steel corrosion

    Science.gov (United States)

    Fazullin, D. D.; Mavrin, G. V.; Shaikhiev, I. G.

    2016-06-01

    The article describes the corrosion test of steel of the brand 20 in the stratal water. To increase corrosion resistance as a corrosion inhibitor the concentrate waste emulsion of the mark "Incam- 1" was provided. The article presents studies of the corrosion rate with different dosages of corrosion inhibitor in the stratal water. Based on these research results are revealed that the degree of protection of steel is 27% at a dosage of 3.8 g / dm3.

  2. Assessment of Commercial Corrosion Inhibiting Admixtures for Reinforced Concrete

    OpenAIRE

    Brown, Michael Carey

    1999-01-01

    Corrosion of reinforcing steel in concrete exposed to chloride-laden environments is a well-known and documented phenomenon. The need for cost effective systems for protection against corrosion has become increasingly clear since the first observations of severe corrosion damage to interstate bridges in the 1960's. As one potential solution to the mounting problem of corrosion deterioration of structures, corrosion-inhibiting admixtures have been researched and introduced into service. ...

  3. A Localised Corrosion Cell for Industrial Applications

    DEFF Research Database (Denmark)

    Andersen, A.; Hilbert, Lisbeth Rischel; Jansen, P.

    2003-01-01

    The LOCORR-CELL™ developed by FORCE TECHNOLOGY is an electrochemical cell for industrial applications estimating localised corrosion. The cell is constructed in a carbon steel casing for direct mounting into the system. It is based on an oxygen concentration element reflecting the interaction...... between the environment formed under a deposit or in a crevice. The essential feature of the method is that it reflects the influence of oxygen content, conductivity and temperature as well as the influence of corrosion inhibitors, MIC and other effects that have an effect on localised corrosion under...

  4. Numerical Modeling of Weld Joint Corrosion

    Science.gov (United States)

    Lu, Yongxin; Jing, Hongyang; Han, Yongdian; Xu, Lianyong

    2016-03-01

    A numerical model is presented in this work that predicts the corrosion rate of weld joint. The model is able to track moving boundary of the corroding constituent of weld joint. The corrosion rates obtained from the model are compared with those estimated from mixed potential theory and two experimental techniques, namely immersion test and constant potential polarization test. The corrosion rate predicted using the model is within 10% of the estimate from the mixed potential theory, within 20% of that got from the immersion experiment and within 10% of that got from the constant potential polarization experiment for weld joint.

  5. Numerical modelling of corrosion - Theoretical backgrounds -

    Energy Technology Data Exchange (ETDEWEB)

    Warkus, J.; Raupach, M. [ibac, RWTH Aachen (Germany); Gulikers, J. [Ministry of Transport, Rijkswaterstaat, Bouwdienst, Utrecht (Netherlands)

    2006-08-15

    During recent years research projects with different approaches have been carried out to develop models which are suitable to assess the metal removal rate in case of reinforcement corrosion. Some of them are based on empirical methods and correlate the corrosion rate to parameters like concrete resistivity, temperature and relative humidity. Another type of model is based on a quantification of the ongoing electrochemical processes. In this paper the theoretical backgrounds and mathematical descriptions of reinforcement corrosion with regard to a numerical modelling are presented and discussed. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  6. Corrosion resistant storage container for radioactive material

    Science.gov (United States)

    Schweitzer, Donald G.; Davis, Mary S.

    1990-01-01

    A corrosion resistant long-term storage container for isolating radioactive waste material in a repository. The container is formed of a plurality of sealed corrosion resistant canisters of different relative sizes, with the smaller canisters housed within the larger canisters, and with spacer means disposed between judxtaposed pairs of canisters to maintain a predetermined spacing between each of the canisters. The combination of the plural surfaces of the canisters and the associated spacer means is effective to make the container capable of resisting corrosion, and thereby of preventing waste material from leaking from the innermost canister into the ambient atmosphere.

  7. A Localised Corrosion Cell for Industrial Applications

    DEFF Research Database (Denmark)

    Andersen, A.; Hilbert, Lisbeth Rischel; Jansen, P.

    2003-01-01

    The LOCORR-CELL™ developed by FORCE TECHNOLOGY is an electrochemical cell for industrial applications estimating localised corrosion. The cell is constructed in a carbon steel casing for direct mounting into the system. It is based on an oxygen concentration element reflecting the interaction...... between the environment formed under a deposit or in a crevice. The essential feature of the method is that it reflects the influence of oxygen content, conductivity and temperature as well as the influence of corrosion inhibitors, MIC and other effects that have an effect on localised corrosion under...

  8. Prévision de l'épaisseur du film passif d'un acier inoxydable 316L soumis au fretting corrosion grâce au Point Defect Model, PDM Predicting the steady state thickness of passive films with the Point Defect Model in fretting corrosion experiments

    Directory of Open Access Journals (Sweden)

    Geringer Jean

    2013-11-01

    Full Text Available Les implants orthopédiques de hanche ont une durée de vie d'environ 15 ans. Par exemple, la tige fémorale d'un tel implant peut être réalisée en acier inoxydable 316L ou 316LN. Le fretting corrosion, frottement sous petits déplacements, peut se produire pendant la marche humaine en raison des chargements répétés entre le métal de la prothèse et l'os. Plusieurs investigations expérimentales du fretting corrosion ont été entreprises. Cette couche passive de quelques nanomètres, à température ambiante, est le point clef sur lequel repose le développement de notre civilisation, selon certains auteurs. Ce travail vise à prédire les épaisseurs de cette couche passive de l'acier inoxydable soumis au fretting corrosion, avec une attention spécifique sur le rôle des protéines. Le modèle utilisé est basé sur le Point Defect Model, PDM (à une échelle microscopique et une amélioration de ce modèle en prenant en compte le processus de frottement sous petits débattements. L'algorithme génétique a été utilisé pour optimiser la convergence du problème. Les résultats les plus importants sont, comme démontré avec les essais expérimentaux, que l'albumine, la protéine étudiée, empêche les dégradations de l'acier inoxydable aux plus faibles concentrations d'ions chlorure ; ensuite, aux plus fortes concentrations de chlorures, un temps d'incubation est nécessaire pour détruire le film passif. Some implants have approximately a lifetime of 15 years. The femoral stem, for example, should be made of 316L/316LN stainless steel. Fretting corrosion, friction under small displacements, should occur during human gait, due to repeated loadings and un-loadings, between stainless steel and bone for instance. Some experimental investigations of fretting corrosion have been practiced. As well known, metallic alloys and especially stainless steels are covered with a passive film that prevents from the corrosion and degradation

  9. The corrosion and corrosion mechanical properties evaluation for the LBB concept in VVERs

    Energy Technology Data Exchange (ETDEWEB)

    Ruscak, M.; Chvatal, P.; Karnik, D.

    1997-04-01

    One of the conditions required for Leak Before Break application is the verification that the influence of corrosion environment on the material of the component can be neglected. Both the general corrosion and/or the initiation and, growth of corrosion-mechanical cracks must not cause the degradation. The primary piping in the VVER nuclear power plant is made from austenitic steels (VVER 440) and low alloy steels protected with the austenitic cladding (VVER 1000). Inspection of the base metal and heterogeneous weldments from the VVER 440 showed that the crack growth rates are below 10 m/s if a low oxygen level is kept in the primary environment. No intergranular cracking was observed in low and high oxygen water after any type of testing, with constant or periodic loading. In the framework of the LBB assessment of the VVER 1000, the corrosion and corrosion mechanical properties were also evaluated. The corrosion and corrosion mechanical testing was oriented predominantly to three types of tests: stress corrosion cracking tests corrosion fatigue tests evaluation of the resistance against corrosion damage. In this paper, the methods used for these tests are described and the materials are compared from the point of view of response on static and periodic mechanical stress on the low alloyed steel 10GN2WA and weld metal exposed in the primary circuit environment. The slow strain rate tests and static loading of both C-rings and CT specimens were performed in order to assess the stress corrosion cracking characteristics. Cyclic loading of CT specimens was done to evaluate the kinetics of the crack growth under periodical loading. Results are shown to illustrate the approaches used. The data obtained were evaluated also from the point of view of comparison of the influence of different structure on the stress corrosion cracking appearance. The results obtained for the base metal and weld metal of the piping are presented here.

  10. Corrosion Effects on the Strength Properties of Steel Fibre Reinforced Concrete Containing Slag and Corrosion Inhibitor

    OpenAIRE

    Sivakumar Anandan; Sounthararajan Vallarasu Manoharan; Thirumurugan Sengottian

    2014-01-01

    Corrosion in steel can be detrimental in any steel rebar reinforced concrete as well as in the case of steel fibre reinforced concrete. The process of corrosion occurring in steel fibre incorporated concrete subjected to corrosive environment was systematically evaluated in this study. Concrete specimens were prepared with steel fibre inclusions at 1.5% Vf (volume fraction) of concrete and were added in slag based concrete (containing manufactured sand) and replaced with cement at 20%, 40%, ...

  11. Development of Copper Corrosion Products and Relation between Surface Appearance and Corrosion Rate

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Tran Thi Ngoc; Binh, Nguyen Thi Thanh [Vietnam National University, Ho Chi Minh (Viet Nam); Tru, Nguyen Nhi [Vietnam Institute for Tropical Technology and Environmental Protection, Ho Chi Minh (Viet Nam); Yoshino, Tsujino [Osaka Prefecture, Osaka (Japan); Yasuki, Maeda [Osaka Prefecture University, Osaka (Japan)

    2008-04-15

    Copper was exposed unsheltered and sheltered in four humid tropical sites, representing urban, urban-industrial, urban-marine and rural environments. The corrosion rates and the sequence of corrosion product formation are presented and discussed in relation with climatic and atmospheric pollution parameters. Chemical compositions of corrosion products were found to depend on environments and duration of exposure. In all environments, cuprite was the predominating corrosion product that formed first and continuously increased during the exposure. Among the sulphur-containing corrosion products, posnjakite and brochantite were more frequently found and the first formed earlier. Nantokite was the most common chlorine-containing products for most cases, except the high-chloride environment, where atacamite was detected instead. The corrosion rate of copper was well indicated by the colour of patina. The red-purple colour corresponded to the high corrosion rate and the greenish grey colour corresponded to the low corrosion rate. Corrosion rate of sheltered copper in urban-marine environment increased with the exposure time.

  12. Electrochemical corrosion behavior of steel wires in a coalmine with a corrosive medium

    Institute of Scientific and Technical Information of China (English)

    Wang Songquan; Zhang Dekun; Wang Dagang; Zhang Zefeng

    2011-01-01

    A 6 × 19 point-contact hoisting cable was used as our research object to examine the progress of corrosion of steel wires in a laboratory, simulating the actual working conditions in a coalmine. An electrochemical method was used to investigate the corrosion behavior of steel wires with different surface treatments of a corrosive acid solution. The results show that anode activation of steel wire mainly occurs during pre-corrosion, where the anode activation process of bare steel wires is the fastest as is their corresponding corrosion speed, while the anode activation process of oil coated steel wires and their corresponding corrosion speed are the lowest. During the intermediate and late immersion periods,a passive film is generated on the surface of steel wires, which are gradually damaged with the passage of time. Local pitting corrosion occurs easily on the surface of steel wires with a high-polarization potential.Suitable equivalent circuits were chosen to fit the electrochemical impedance spectroscopy (EIS) of steel wires over various corrosive times and different surface treatments, which indicate good fitting results.The double electrical layer charge-transfer resistance increases in the sequence: bare steel wire,untreated steel wire and oil coated steel wire and their corrosion resistance decreases in turn, which is consistent with their polarization curves. The oil layer provides a certain protective effect on untreated steel wires, but its effect is not entirely clear.

  13. CORROSION INHIBITION BY CASHEW NUT SHELL

    African Journals Online (AJOL)

    is the primary step in the action of organic corrosion inhibitors (Trabanelli. 1989). ... polarized. Electrochemical Impedance Spectroscopy (EIS) measurements .... solutions and UV/VIS to determine the adsorption of the CNSL inhibitor on.

  14. Fighting against corrosion; Kampf dem Substanzverlust

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2012-03-09

    Corrosion protection is not a new problem for the offshore industry, but requirements are particularly high in the wind power industry. There are hardly any international standards that could provide orientation.

  15. Fatigue - corrosion of endoprosthesis titanium alloys.

    Science.gov (United States)

    Cornet, A; Muster, D; Jaeger, J H

    1979-01-01

    Commercial total hip prostheses often show certain metallurgical faults (porosities, coarse grains, growth dendrites, carbide networks). In order to investigate more accurately the role played by these different parameters in prostheses failure we performed a large number of systematic corrosion, fatigue and fatigue - corrosion tests on these materials and on commercial total hip prostheses. Ultimate strengthes seem to be reached for cast cobalt alloys, whereas titanium alloys, such as Ta 6 V, present very high fatigue limit under corrosion. Thus, rotative bending fatigue - corrosion tests in biological environment provide values about 50 DaN/mm2. This value, is nevertheless appreciably higher than those obtained with stellites and stainless steel. Titanium alloys, because of their mechanical performances, their weak Young's modulus (11000 DaN/mm2) and their relative lightness (4.5. g/cm3), which are associated with a good biocompatibility, seem very promising for permanent implants realisation.

  16. High resolution in situ ultrasonic corrosion monitor

    Science.gov (United States)

    Grossman, R.J.

    1984-01-10

    An ultrasonic corrosion monitor is provided which produces an in situ measurement of the amount of corrosion of a monitoring zone or zones of an elongate probe placed in the corrosive environment. A monitoring zone is preferably formed between the end of the probe and the junction of the zone with a lead-in portion of the probe. Ultrasonic pulses are applied to the probe and a determination made of the time interval between pulses reflected from the end of the probe and the junction referred to, both when the probe is uncorroded and while it is corroding. Corresponding electrical signals are produced and a value for the normalized transit time delay derived from these time interval measurements is used to calculate the amount of corrosion.

  17. Polarized Neutron Reflectometry of Nickel Corrosion Inhibitors.

    Science.gov (United States)

    Wood, Mary H; Welbourn, Rebecca J L; Zarbakhsh, Ali; Gutfreund, Philipp; Clarke, Stuart M

    2015-06-30

    Polarized neutron reflectometry has been used to investigate the detailed adsorption behavior and corrosion inhibition mechanism of two surfactants on a nickel surface under acidic conditions. Both the corrosion of the nickel surface and the structure of the adsorbed surfactant layer could be monitored in situ by the use of different solvent contrasts. Layer thicknesses and roughnesses were evaluated over a range of pH values, showing distinctly the superior corrosion inhibition of one negatively charged surfactant (sodium dodecyl sulfate) compared to a positively charged example (dodecyl trimethylammonium bromide) due to its stronger binding interaction with the surface. It was found that adequate corrosion inhibition occurs at significantly less than full surface coverage.

  18. Localized Corrosion of Chromium Coated Steel

    NARCIS (Netherlands)

    Zhang, X.; Beentjes, P.; Mol, A.; Terryn, H.

    2006-01-01

    In this paper, we report on the studies of the local corrosion behaviour of chromium-coated ultra low carbon steel in NaCl solution using polarization, electrochemical impedance spectroscopy (EIS) and SVET.

  19. Amplified OTDR systems for multipoint corrosion monitoring.

    Science.gov (United States)

    Nascimento, Jehan F; Silva, Marcionilo J; Coêlho, Isnaldo J S; Cipriano, Eliel; Martins-Filho, Joaquim F

    2012-01-01

    We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR) technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

  20. Amplified OTDR Systems for Multipoint Corrosion Monitoring

    Directory of Open Access Journals (Sweden)

    Joaquim F. Martins-Filho

    2012-03-01

    Full Text Available We present two configurations of an amplified fiber-optic-based corrosion sensor using the optical time domain reflectometry (OTDR technique as the interrogation method. The sensor system is multipoint, self-referenced, has no moving parts and can measure the corrosion rate several kilometers away from the OTDR equipment. The first OTDR monitoring system employs a remotely pumped in-line EDFA and it is used to evaluate the increase in system reach compared to a non-amplified configuration. The other amplified monitoring system uses an EDFA in booster configuration and we perform corrosion measurements and evaluations of system sensitivity to amplifier gain variations. Our experimental results obtained under controlled laboratory conditions show the advantages of the amplified system in terms of longer system reach with better spatial resolution, and also that the corrosion measurements obtained from our system are not sensitive to 3 dB gain variations.

  1. Electrochemical Corrosion of Carbon—Containing Refractories

    Institute of Scientific and Technical Information of China (English)

    CHENZhao-you

    1994-01-01

    The electrochemical examination on the cor-rosion of carbon or carbon containing refractiories at molten slag-liquid interface has been carried out.The electromotive force(E.M.F)of cells with different molten slags:C|molten slag | Fe at elevated temperatures has been measured by means of potentiometer and it is in the range from 250 to 450mV .It is found that the carbon electrode in these cells is anode and whn a counter E.M.F.is applied externally to the cel,the corrosion of carbon electrode will be sup-pressed entirely.Test results show that the local corrosion of carbon containing refractories at slag-metal interface is mainly caused by the mechanism of electrochemical corrosion.

  2. Controlling Corrosion in Defence Equipment - Technical Meeting,

    Science.gov (United States)

    1985-10-01

    corrosion of Ni/Al bronze in neutral solution, (2) the inhibited corrosion of mild steel in sulphuric acid, (3) comparison and ranking of a number of... electropolish : alkaline clean: pumice scrub: anodic etch: chromium plate. It must be remembered that mild steel is not being used, but a low alloy steel ...Wolsley shows no such damage. After all they are both made - from similar steels and both have been exposed to the two essential ingredients required

  3. Preventing Corrosion by Controlling Cathodic Reaction Kinetics

    Science.gov (United States)

    2016-03-25

    Preventing corrosion by controlling cathodic reaction kinetics Progress Report for Period: 1 SEP 2015-31 MAR 2016 John Keith Department of...25 March 2016 Preventing corrosion by controlling cathodic reaction kinetics Annual Summary Report: FY16 PI: John Keith, 412-624-7016,jakeith...dominate the metal’s cathodic behavior. Within an alkaline environment, we expect the following reduction reactions to be catalyzed on the oxide

  4. Corrosion of surface defects in fine wires.

    Science.gov (United States)

    Rentler, R M; Greene, N D

    1975-11-01

    Defects were observed on the surfaces of various fine diameter wires commonly used in biomedical applications. These surface irregularities were viewed at high magnifications using a scanning electron microscope which has a much greater depth of field than normal light microscopy. Defects include scratches, pits, and crevices, which are the result of commercial wire drawing practices. Corrosion test results show that imperfections can serve as sites for localized corrosion attack which could lead to premature failures.

  5. METAL CORROSION IN WATERBORNE PRESERVATIVE- TREATED WOOD

    Directory of Open Access Journals (Sweden)

    Krisdianto Sugiyanto

    2010-12-01

    Full Text Available The rigidity and firmness of wooden construction and furniture those are joined by metal screws depend on corrosion rate of these metals. This paper examines the weight-loss percentage of metal screws used in wood samples that have been treated with water-borne preser vative (i.e.3% borax boric acid and 3% diffusol CB and concurrently investigates the effect of brake fluid on preventing metal corrosion. Wood samples tested included three acacia and one eucalypts wood species which were grouped into sapwood and heartwood containing samples. Wood samples fastened with metal screws were freely suspended in glass jars that contained 25 ml of sulphuric acid (H2SO4 to keep the humidity rate above 90%. After 12 months, the metal screws lost their weight due to the corrosion brought about by the related factors either in separate individual or in combination, which comprised brake and fluid-dipping , wood species, wood portion (sapwood and heartwood, kinds of preser vatives used. Corrosion rates of metal screws fastened in eucalypts wood sample as indicated by the screw-weight loss (i.e. 5.8% was more severe than that fastened in acacia wood. Furthermore, corrosion rate of metal screws as fixed firmly in sapwood sample proceeded faster than that in heartwood. This might be caused by the higher moisture content in sapwood. On the other hand, corrosion rate of the screws as fastened in waterborne-preser vative-treated wood samples was greater than that in non-preser ved wood due to electrokinetic characteristics and ionic potential exhibited by the preser vative thereby intensif ying the screw-corrosion process. Meanwhile, less severe corrosion was obser ved and recorded on the screws pre-dipped in brake fluid compared to those on the non-dipped screws

  6. Aqueous Corrosion Rates for Waste Package Materials

    Energy Technology Data Exchange (ETDEWEB)

    S. Arthur

    2004-10-08

    The purpose of this analysis, as directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), is to compile applicable corrosion data from the literature (journal articles, engineering documents, materials handbooks, or standards, and national laboratory reports), evaluate the quality of these data, and use these to perform statistical analyses and distributions for aqueous corrosion rates of waste package materials. The purpose of this report is not to describe the performance of engineered barriers for the TSPA-LA. Instead, the analysis provides simple statistics on aqueous corrosion rates of steels and alloys. These rates are limited by various aqueous parameters such as temperature (up to 100 C), water type (i.e., fresh versus saline), and pH. Corrosion data of materials at pH extremes (below 4 and above 9) are not included in this analysis, as materials commonly display different corrosion behaviors under these conditions. The exception is highly corrosion-resistant materials (Inconel Alloys) for which rate data from corrosion tests at a pH of approximately 3 were included. The waste package materials investigated are those from the long and short 5-DHLW waste packages, 2-MCO/2-DHLW waste package, and the 21-PWR commercial waste package. This analysis also contains rate data for some of the materials present inside the fuel canisters for the following fuel types: U-Mo (Fermi U-10%Mo), MOX (FFTF), Thorium Carbide and Th/U Carbide (Fort Saint Vrain [FSVR]), Th/U Oxide (Shippingport LWBR), U-metal (N Reactor), Intact U-Oxide (Shippingport PWR, Commercial), aluminum-based, and U-Zr-H (TRIGA). Analysis of corrosion rates for Alloy 22, spent nuclear fuel, defense high level waste (DHLW) glass, and Titanium Grade 7 can be found in other analysis or model reports.

  7. Materials corrosion and protection at high temperatures; Corrosion et protection des materiaux a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Balbaud, F.; Desgranges, Clara; Martinelli, Laure; Rouillard, Fabien [CEA-Saclay, DEN, DPC, SCCME, Laboratoire d' Etude de la Corrosion Non Aqueuse, 91191 Gif-sur-Yvette Cedex (France); Duhamel, Cecile [Mines ParisTech, Centre des materiaux UMR-CNRS 7633, BP 87, 91003 Evry Cedex (France); Marchetti, Loic; Perrin, Stephane [CEA, Laboratoire d' Etude de la Corrosion Aqueuse (France); Molins, Regine [Mines ParisTech, Direction de la Recherche, 60 Bvd Saint Michel, 75272 Paris Cedex 06 (France); Chevalier, S.; Heintz, O. [Laboratoire interdisciplinaire Carnot de Bourgogne, UMR 5209 CNRS, Univ. de Bourgogne, Dijon (France); David, N.; Fiorani, J.M.; Vilasi, M. [Institut Jean Lamour, UMR 7198, Univ. Henri Poincare Nancy-1 - CNRS, 54506 Vandoeuvre-les-Nancy (France); Wouters, Y.; Galerie, A. [SIMAP UMR CNRS 5266, Grenoble-INP/UJF, 1130 rue de la Piscine BP 75, 38402 Saint-Martin-d' Heres Cedex (France); Mangelinck, D. [IM2NP, UMR6242, CNRS, Univ. Paul Cezanne, Case 142, Faculte de Saint Jerome, 13397 Marseille Cedex 20 (France); Viguier, B.; Monceau, D. [Univ. de Toulouse, Institut Carnot CIRIMAT, INP-ENSIACET, 4 allee Emile Monso, BP 44362, 31030 Toulouse Cedex 4 (France); Soustelle, M. [Ecole nationale superieure des mines, Saint Etienne (France); Pijolat, M. [Centre Spin, Ecole des mines de Saint Etienne (France); Favergeon, J.; Brancherie, D.; Moulin, G.; Dawi, K. [Laboratoire Roberval, UTC (France); Wolski, K.; Barnier, V. [Centre SMS, EMSE, UMR 5146, LCG, Univ. de Lyon, 158 Cours Fauriel, 42023 Saint Etienne (France); Rebillat, F. [LCTS, Univ. de Bordeaux (France); Lavigne, O. [Onera, Dep. Materiaux et Structures Metalliques, BP 72, 29 av. de la Division Leclerc, 92322 Chatillon (France); Brossard, J.M. [Dep. energetique et procedes, Veolia Environnement Recherche et Innovation, Limay (France); Ropital, F. [IFP Energies Nouvelles, BP 3, 69360 Solaize (France); Mougin, J. [CEA-Liten, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    2011-07-01

    This book was made from the lectures given in 2010 at the thematic school on 'materials corrosion and protection at high temperatures'. It gathers the contributions from scientists and engineers coming from various communities and presents a state-of-the-art of the scientific and technological developments concerning the behaviour of materials at high temperature, in aggressive environments and in various domains (aerospace, nuclear, energy valorization, and chemical industries). It supplies pedagogical tools to grasp high temperature corrosion thanks to the understanding of oxidation mechanisms. It proposes some protection solutions for materials and structures. Content: 1 - corrosion costs; macro-economical and metallurgical approach; 2 - basic concepts of thermo-chemistry; 3 - introduction to the Calphad (calculation of phase diagrams) method; 4 - use of the thermodynamic tool: application to pack-cementation; 5 - elements of crystallography and of real solids description; 6 - diffusion in solids; 7 - notions of mechanics inside crystals; 8 - high temperature corrosion: phenomena, models, simulations; 9 - pseudo-stationary regime in heterogeneous kinetics; 10 - nucleation, growth and kinetic models; 11 - test experiments in heterogeneous kinetics; 12 - mechanical aspects of metal/oxide systems; 13 - coupling phenomena in high temperature oxidation; 14 - other corrosion types; 15 - methods of oxidized surfaces analysis at micro- and nano-scales; 16 - use of SIMS in the study of high temperature corrosion of metals and alloys; 17 - oxidation of ceramics and of ceramic matrix composite materials; 18 - protective coatings against corrosion and oxidation; 19 - high temperature corrosion in the 4. generation of nuclear reactor systems; 20 - heat exchangers corrosion in municipal waste energy valorization facilities; 21 - high temperature corrosion in oil refining and petrochemistry; 22 - high temperature corrosion in new energies industry. (J.S.)

  8. Controlling internal corrosion of oil and gas pipelines : the corrosion inhibitor selection software (CISS) program

    Energy Technology Data Exchange (ETDEWEB)

    Doiron, A.; Papavinasam, S. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

    2009-07-01

    The internal pitting corrosion of oil and gas pipelines can be effectively controlled through the addition of inhibitors. However, simulation of field operating conditions is necessary because the performance of corrosion inhibitors is influenced by several interacting parameters. This paper reviewed the Corrosion Inhibitor Selection Software (CISS) program. The materials transported in production pipelines are often multiphase, containing oil, aqueous (brine), and gas phases. The corrosion rate and inhibitor performance are influenced by composition, temperature, flow and pressure. Steel composition and structure also influence both the rate and type of corrosion. Improvements in corrosion test methodologies are aimed at simulating field corrosion conditions in the laboratory in a compressed time-scale. The parameters that influence the types of corrosion must be simulated in order for laboratory methodology to be relevant. The variables controlled should be quantifiable. There should also be a correlation between the influence of variables controlled in the laboratory and of the same variables in the field. The CISS program evaluates inhibitors in the following 4 steps: (1) pipeline operating conditions, (2) selection of laboratory methodology, (3) determination of operating conditions for the laboratory methodologies, and (4) selection of corrosion inhibitors. The 7 objectives of the CISS program are to optimize the strategies of inhibitor selection for pipeline applications; determine the hydrodynamic parameters of the pipe from field operating conditions; select appropriate laboratory methodologies for evaluating inhibitors; determine flow conditions for high-shear laboratory methodologies; develop a qualitative relationship between corrosion rates of non-shear laboratory methodologies and of pipelines; evaluate corrosion inhibitors based on results from different laboratory methodologies; and design cost-effective inhibitors for future applications. 47 refs

  9. Silica nanocontainers for active corrosion protection

    Science.gov (United States)

    Maia, Frederico; Tedim, João; Lisenkov, Aleksey D.; Salak, Andrei N.; Zheludkevich, Mikhail L.; Ferreira, Mário G. S.

    2012-02-01

    Novel self-healing protective coatings with nanocontainers of corrosion inhibitors open new opportunities for long-term anticorrosion protection of different metallic materials. In this paper a new type of functional nanoreservoir based on silica nanocapsules (SiNC) synthesized and loaded with corrosion inhibitor 2-mercaptobenzothiazole (MBT) in a one-stage process is reported for the first time. Unlike conventional mesoporous silica nanoparticles, SiNC possess an empty core and shell with gradual mesoporosity, arising from the particular conditions of the synthetic route adopted, which confers significant loading capacity and allows prolonged and stimuli-triggered release of the inhibiting species. The kinetics of inhibitor release was studied at different pH values and concentrations of NaCl. The results show a clear dependence of the release profiles on corrosion relevant triggers such as pH and Cl- concentration. When SiNC loaded with MBT are dispersed in NaCl solution, there is a significant decrease of the corrosion activity on aluminium alloy 2024. More importantly, when SiNC-MBT is added to a conventional water-based coating formulation, the modified coating hampers corrosion activity at the metal interface, better than in the case of direct addition of corrosion inhibitor. Furthermore, self-healing is observed before and after artificially inflicting defects in the modified coatings. As a result, the developed nanocontainers show high potential to be used in new generation of active protective coatings.

  10. Theoretical Analysis of Reinforcement Tunnel Lining Corrosion

    Directory of Open Access Journals (Sweden)

    ZhiQiang Zhangand

    2013-05-01

    Full Text Available The main cause of ageing damage in reinforced concrete structures is reinforcement corrosion. Damage can be detected visually as coincident cracks along the reinforcement bar, which are significant of both reduction of the re-bar, cross-section and loss of bond strength for reinforced concrete. The reinforced concrete is one of the most widely used engineering materials as final lining of tunnels. The corrosion is common durability problems that have significant effect on the tunnel performance. This study intends to analysis reinforcement concrete corrosion at the tunnel lining by applying temperature expansion theory on steel through numerical simulation process, with expansive force effect. The thickness of concrete cover and the diameter of steel bar have an impact on the stress for reinforcement concrete during propagation of corrosion process. The corrosion cracks appear at the corner of a tunnel lining then in invert and vault because the maximum stress will be in the corner then in invert and vault. The internal force in the concrete lining changes differently when the corrosion rate change.

  11. Recent Developments on Autonomous Corrosion Protection Through Encapsulation

    Science.gov (United States)

    Li, W.; Buhrow, J. W.; Calle, L. M.; Gillis, M.; Blanton, M.; Hanna, J.; Rawlins, J.

    2015-01-01

    This paper concerns recent progress in the development of a multifunctional smart coating, based on microencapsulation, for the autonomous detection and control of corrosion. Microencapsulation has been validated and optimized to incorporate desired corrosion control functionalities, such as early corrosion detection and inhibition, through corrosion-initiated release of corrosion indicators and inhibitors, as well as self-healing agent release triggered by mechanical damage. While proof-of-concept results have been previously reported, more recent research and development efforts have concentrated on improving coating compatibility and synthesis procedure scalability, with a targeted goal of obtaining easily dispersible pigment-grade type microencapsulated materials. The recent progress has resulted in the development of pH-sensitive microparticles as a corrosion-triggered delivery system for corrosion indicators and inhibitors. The synthesis and early corrosion indication results obtained with coating formulations that incorporate these microparticles are reported. The early corrosion indicating results were obtained with color changing and with fluorescent indicators.

  12. Controlled-Release Microcapsules for Smart Coatings for Corrosion Applications

    Science.gov (United States)

    2008-01-01

    Corrosion is a serious problem that has enormous costs and serious safety implications. Localized corrosion, such as pitting, is very dangerous and can cause catastrophic failures. The NASA Corrosion Technology Laboratory at Kennedy Space Center is developing a smart coating based on pH-sensitive microcapsules for corrosion applications. These versatile microcapsules are designed to be incorporated into a smart coating and deliver their core content when corrosion starts. Corrosion indication was the first function incorporated into the microcapsules. Current efforts are focused on incorporating the corrosion inhibition function through the encapsulation of corrosion inhibitors into water core and oil core microcapsules. Scanning electron microscopy (SEM) images of encapsulated corrosion inhibitors are shown.

  13. Corrosion behaviour of non-ferrous metals in sea water

    Energy Technology Data Exchange (ETDEWEB)

    Birn, Jerzy; Skalski, Igor [Ship Design and Research Centre, Al. Rzeczypospolitej 8, 80-369 Gdansk (Poland)

    2004-07-01

    The most typical kinds of corrosion of brasses are selective corrosion (dezincification) and stress corrosion. Prevention against these kinds of corrosion lies in application of arsenic alloy addition and appropriate heat treatment removing internal stresses as well as in maintaining the arsenic and phosphorus contents on a proper level. The most typical corrosion of cupronickels is the local corrosion. Selective corrosion occurs less often and corrosion cracking caused by stress corrosion in sea water does not usually occur. Crevice corrosion is found especially in places of an heterogeneous oxidation of the surface under inorganic deposits or under bio-film. Common corrosive phenomena for brasses and cupronickels are the effects caused by sea water flow and most often the impingement attack. Alloy additions improve resistance to the action of intensive sea water flow but situation in this field requires further improvement, especially if the cheaper kinds of alloys are concerned. Contaminants of sea water such as ammonia and hydrogen sulphide are also the cause of common corrosion processes for all copper alloys. Corrosion of copper alloys may be caused also by sulphate reducing bacteria (SRB). Galvanic corrosion caused by a contact with titanium alloys e.g. in plate heat exchangers may cause corrosion of both kinds copper alloys. Bronzes belong to copper alloys of the highest corrosion resistance. Failures that sometimes occur are caused most often by the cavitation erosion, by an incorrect chemical composition of alloys or at last by their inadequate structure. The main problems of aluminium alloys service in sea water are following phenomena: local corrosion (pitting and crevice corrosion), galvanic corrosion, exfoliation and corrosion in the presence of OH- ions. The cause of local corrosion are caused by presence of passive film on the alloy's surface and presence of chlorides in sea water which are able to damage the passive film. Galvanic corrosion is

  14. Corrosion studies in brines of the Salton Sea Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Carter, J.P.; McCawley, F.X.; Cramer, S.D.; Needham, P.B. Jr.

    1979-01-01

    Toward the goal of maximizing minerals and metals recovery from domestic resources, the Bureau of Mines, U.S. Department of the Interior, has conducted in situ corrosion studies at the Salton Sea Known Geothermal Resources Area (KGRA) in the Imperial Valley, Calif., to evaluate and characterize materials of construction for geothermal resources recovery plants. General-, pitting, and crevice-corrosion characteristics of 13 commercially available alloys were investigated for periods of 15 and 30 days in seven process environments expected to be found in typical geothermal resources plants. Stainless steel alloy 29-4, Inconel 625, and the Hastelloys G, S, and C-276 were the most resistant to general corrosion, did not pit, and exhibited little susceptibility to crevice corrosion. Stainless steel alloys 430, E-Brite 26-1, and 6X had low general corrosion rates, but pitted and were susceptible to crevice corrosion. Stainless steel alloy 316 L had a low corrosion rate, but corroded intergranularly, pitted, and was susceptible to crevice corrosion and to stress-corrosion cracking. Titanium--1.5 nickel and TiCode-12 had low corrosion rates, did not pit, and were not susceptible to crevice corrosion. Carbon and 4130 steels had high corrosion rates, pitted, and had high susceptibilities to crevice corrosion. The major scale-forming mineral on the corrosion samples in most of the process environments studied was galena mixed with lesser amounts of other minerals.

  15. La mixité scolaire, la coéducation sous la Seconde République en Espagne

    Directory of Open Access Journals (Sweden)

    Elvire Diaz

    2007-11-01

    Full Text Available Le débat sur la mixité scolaire, appelée coéducation, indissociable de l'enseignement féminin et des droits des femmes, fut largement ouvert en Espagne sous la Seconde République (1931-1936. Nous traiterons de l’état des mentalités quant à l’éducation des filles au travers de trois exemples d’opinion : Mirguet, Sarabia, Mihura. Ces exemples illustrent des tendances opposées à la coéducation, pour des raisons religieuse, morale ou réactionnaire, du fait même que l'éducation des filles reste un monde à part. Malgré toutes les propositions pour établir un programme scolaire et éducatif pour les jeunes filles, il ressort que paradoxalement les auteurs, d'idéologie ou de nationalité différentes ou dont les objectifs diffèrent, se recoupent de manière significative : l'éducation est une adéquation de la femme à son milieu et à son rôle et statut traditionnels.The debate on co-education, inevitably linked with the education of girls and women’s rights, was wide-ranging during the Spanish Second Republic (1931-1936. Attitudes towards girls’ education will be examined by looking at three examples of opinion: Mirguet, Sarabia and Mihura. These examples illustrate opposing points of view on co-education, based on religious, moral or reactionary grounds, since girls’ education remained a world apart. In spite of proposals to establish a school curriculum for young girls, paradoxically, the authors, with differeing ideologies, nationalities and aims, are significantly similar: education for girls should develop a harmonious link between girls’ background, and their traditional role and status.

  16. L’économie américaine sous l’Administration Bush The US Economy under the Bush Administration

    Directory of Open Access Journals (Sweden)

    Frédéric Lambert

    2010-03-01

    Full Text Available Cet article dresse un bilan de la performance économique américaine au cours des huit années de la présidence Bush. Sous l’Administration Bush, et après une année de récession consécutive à l’éclatement de la « bulle internet », l’économie américaine a connu six années d’expansion. Cette expansion a été plus forte que dans les autres économies du G7, grâce notamment à une croissance plus élevée de la productivité et à une politique monétaire accommodante. Elle s’est néanmoins accompagnée d’un certain nombre de déséquilibres qui pesaient sur la situation dans les derniers mois de la présidence Bush.This article surveys the performance of the US economy over the eight years of the Bush Presidency. Under the Bush Administration and after a year of recession following the bursting of the internet bubble, the American economy enjoyed six years of expansion. This expansion was stronger than in the other G7 economies, thanks in particular to higher productivity growth and a very supportive monetary policy. However, it was the source of several imbalances which weighed on the situation as the Bush Presidency was drawing to a close.

  17. Effets Seebeck et Nernst dans les cuprates: Etude de la reconstruction de la surface de Fermi sous champ magnetique intense

    Science.gov (United States)

    Laliberte, Francis

    2010-06-01

    Ce memoire presente des mesures de transport thermoelectrique, les effets Seebeck et Nernst, dans une serie d'echantillons de supraconducteurs a haute temperature critique. Des resultats obtenus recemment au Laboratoire National des Champs Magnetiques Intenses a Grenoble sur La1.7Eu0.2Sr0.1 CuO4, La1.675Eu0.2Sr0.125CuO 4, La1.64Eu0.2Sr0.16CuO4, La1.74Eu0.1Sr0.16CuO4 et La 1.4Nd0.4Sr0.2CuO4 sont analyses. Une attention particuliere est accordee aux equations de la theorie semi-classique du transport et leur validite est verifiee. La procedure experimentale et les materiaux utilises pour concevoir les montages de mesures sont expliques en detail. Enfin, un chapitre est dedie a l'explication et l'interpretation des resultats de transport thermoelectrique sur YBa2Cu3O6+delta publies au cours de l'hiver 2010 dans les revues Nature et Physical Review Letters. Les donnees d'effet Seebeck dans les echantillons de La 1.8-x,Eu0.2SrxCuO 4, ou un changement de signe est observe, permettent de conclure a la presence d'une poche d'electrons dans la surface de Fermi qui domine le transport a basse temperature dans la region sous-dopee du diagramme de phase. Cette conclusion est similaire a celle obtenue par des mesures d'effet Hall dans YBa 2Cu3O6+delta et elle cadre bien dans un scenario de reconstruction de la surface de Fermi. Les donnees d'effet Nernst recueillies indiquent que la contribution des fluctuations supraconductrices est limitee a un modeste intervalle de temperature au-dessus de la temperature critique.

  18. Developpement d'un modele analytique pour l'analyse en elasticite lineaire de champs de deformation et contrainte au sein d'un polycristal. comparaison avec la methode des elements finis =

    Science.gov (United States)

    Bretin, Remy

    L'endommagement par fatigue des materiaux est un probleme courant dans de nombreux domaines, dont celui de l'aeronautique. Afin de prevenir la rupture par fatigue des materiaux il est necessaire de determiner leur duree de vie en fatigue. Malheureusement, dues aux nombreuses heterogeneites presentes, la duree de vie en fatigue peut fortement varier entre deux pieces identiques faites dans le meme materiau ayant subi les memes traitements. Il est donc necessaire de considerer ces heterogeneites dans nos modeles afin d'avoir une meilleure estimation de la duree de vie des materiaux. Comme premiere etape vers une meilleure consideration des heterogeneites dans nos modeles, une etude en elasticite lineaire de l'influence des orientations cristallographiques sur les champs de deformations et de contraintes dans un polycristal a ete realisee a l'aide de la methode des elements finis. Des correlations ont pu etre etablies a partir des resultats obtenus, et un modele analytique en elasticite lineaire prenant en compte les distributions d'orientations cristallographiques et les effets de voisinage a pu etre developpe. Ce modele repose sur les bases des modeles d'homogeneisation classique, comme le schema auto-coherent, et reprend aussi les principes de voisinage des automates cellulaires. En prenant pour reference les resultats des analyses elements finis, le modele analytique ici developpe a montre avoir une precision deux fois plus grande que le modele auto-coherent, quel que soit le materiau etudie.

  19. La pollution des sols des champs d’épandage d’eaux usées, contrainte et/ou ressource pour le développement durable en plaine de Bessancourt-Herblay-Pierrelaye

    Directory of Open Access Journals (Sweden)

    Vincent Mandinaud

    2005-11-01

    Full Text Available Historiquement affectés à l’assainissement des eaux usées brutes et à l’amendement des sols, les champs d’épandage de la ville de Paris, puis du SIAAP, sont au début de l’année 1997 en passe d’être publiquement reconnus pollués par des Eléments Traces Métalliques (ETM . Différentes opérations participent de ce double processus de reconsidération des risques associés à l’épandage et de requalification des entités territoriales concernées. La présentation dynamique des prises et des contraintes développées, en plaine de Bessancourt-Herblay-Pierrelaye singulièrement, permet de montrer comment la pollution des sols peut (réactiver localement une réflexion collective sur un développement territorial durable.

  20. Corrosion Behavior of S450EW Low-alloy Weathering Steel in Cyclically Alternate Corrosion Environments

    Institute of Scientific and Technical Information of China (English)

    Jun-shan WANG; Pei-yang SHI; Cheng-jun LIU; Mao-fa JIANG

    2015-01-01

    Weathering steel is widely used in various ifelds due to its excellent mechanical properties and high corrosion resistance. The effect of chromium content on the S450EW weathering steel in cyclic immersion test was studied. The results indicated that the corrosion resistance of S450EW weathering steel is closely related to chromium content. The addition of chromium signiif-cantly inhibited the weathering steel corrosion. The corrosion rate of experimental steel after 96 h immersion was 1.101 g·m−2·h−1. The rust of S450EW weathering steel was mainly constituted of FeOOH and Fe3O4 phase, and the elevation of chromium content promoted the formation of α-FeOOH. The ifne precipitates of the two phases contributed to the formation of dense dust layer of test steel. Furthermore, the increase of chromium is beneifcial for the cure of original defects and cracks of the rust layer via the enrich-ment of chromium. The corrosion potential and the resistance of corrosion process were thus increased, protecting the experimental steel from further corrosion. A S450EW steel with corrosion resistance more than 1.5 times of Q450NQR1 steel was prepared.

  1. The Corrosion Inhibition Characteristics of Sodium Nitrite Using an On-line Corrosion Rate Measurement System

    Energy Technology Data Exchange (ETDEWEB)

    Park, Mal-Yong; Kang, Dae-Jin [Korea Polytechnic University, Shiheung (Korea, Republic of); Moon, Jeon-Soo [Future Technology Research Laboratory, KEPCO Research Institute, Daejeon (Korea, Republic of)

    2015-04-15

    An on-line corrosion rate measurement system was developed using a personal computer, a data acquisition board and program, and a 2-electrode corrosion probe. Reliability of the developed system was confirmed with through comparison test. With this system, the effect of sodium nitrite (NaNO{sub 2}) as a corrosion inhibitor were studied on iron and aluminum brass that were immersed in sodium chloride (NaCl) solution. Corrosion rate was measured based on the linear polarization resistance method. The corrosion rates of aluminum brass and iron in 1% NaCl solutions were measured to be 0.290 mm per year (mmpy) and 0.2134 mmpy, respectively. With the addition of 200 ppm of NO{sub 2}{sup -}, the corrosion rates decreased to 0.0470 mmpy and 0.0254 mmpy. The addition of NO{sub 2}{sup -} caused a decrease in corrosion rates of both aluminum brass and iron, yet the NO{sub 2}{sup -} acted as a more effective corrosion inhibitor for iron. than aluminum brass.

  2. A study of microbial population dynamics associated with corrosion rates influenced by corrosion control materials

    NARCIS (Netherlands)

    Chang, Yu Jie; Hung, Chun Hsiung; Lee, Jyh Wei; Chang, Yi Tang; Lin, Fen Yu; Chuang, Chun Jie

    2015-01-01

    This research aims to analyze the variations of microbial community structure under anaerobic corrosive conditions, using molecular fingerprinting method. The effect of adding various materials to the environment on the corrosion mechanism has been discussed. In the initial experiment, sulfate-re

  3. NASA's Beachside Corrosion Test Site and Current Environmentally Friendly Corrosion Control Initiatives

    Science.gov (United States)

    Russell, Richard W.; Calle, Luz Marina; Johnston, Frederick; Montgomery, Eliza L.; Curran, Jerome P.; Kolody, Mark R.

    2013-01-01

    NASA began corrosion studies at the Kennedy Space Center (KSC) in 1966 during the Gemini/Apollo Programs with the evaluation of long-term corrosion protective coatings for carbon steel. KSC's Beachside Corrosion Test Site (BCTS), which has been documented by the American Society of Materials (ASM) as one of the most corrosive, naturally occurring, environments in the world, was established at that time. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pad were rendered even more severe by the acid ic exhaust from the solid rocket boosters. In the years that followed, numerous studies have identified materials, coatings, and maintenance procedures for launch hardware and equipment exposed to the highly corrosive environment at the launch pad. This paper presents a historical overview of over 45 years of corrosion and coating evaluation studies and a description of the BCTS's current capabilities. Additionally, current research and testing programs involving chromium free coatings, environmentally friendly corrosion preventative compounds, and alternates to nitric acid passivation will be discussed.

  4. A study of microbial population dynamics associated with corrosion rates influenced by corrosion control materials

    NARCIS (Netherlands)

    Chang, Yu Jie; Hung, Chun Hsiung; Lee, Jyh Wei; Chang, Yi Tang; Lin, Fen Yu; Chuang, Chun Jie

    2015-01-01

    This research aims to analyze the variations of microbial community structure under anaerobic corrosive conditions, using molecular fingerprinting method. The effect of adding various materials to the environment on the corrosion mechanism has been discussed. In the initial experiment,

  5. Analysis of corrosion failure of petrochemical pipe elbow

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-yan; L(U) Tao

    2005-01-01

    Corrosive failure is frequently found in petrochemical pipelines which may lead to the leakage of the pipes and even the shutdown of the system. However, the corrosion mechanism is still not well understood due to the complex service environment, e.g. the corrosive fluids and the long term operation at higher temperature. The corrosion behaviour of a petrochemical pipe elbow was evaluated via visual examination and microanalysis with optical microscope and scanning electron microscope(SEM) together with energy dispersive analysis X-ray (EDAX). The corresponding corrosion mechanisms, the combination of grain boundary attach and the crevice attach together with the flow-accelerated corrosion, were proposed consequently.

  6. High temperature corrosion during biomass firing: improved understanding by depth resolved characterisation of corrosion products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2015-01-01

    The high temperature corrosion of an austenitic stainless steel (TP 347H FG), widely utilised as a superheater tube material in Danish power stations, was investigated to verify the corrosion mechanisms related to biomass firing. KCl coated samples were exposed isothermally to 560 degrees C...... changes within the near surface region (covering both the deposit and the steel surface). Such cross-section analysis was further complemented by plan view investigations (additionally involving X-ray diffraction) combined with removal of the corrosion products. Improved insights into the nature...... of the corrosion products as a function of distance from the deposit surface were revealed through this comprehensive characterisation. Corrosion attack during simulated straw-firing conditions was observed to occur through both active oxidation and sulphidation mechanisms....

  7. Electromagnetic circulation pump for corrosive gases; Pompe de circulation electromagnetique pour gaz corrosifs

    Energy Technology Data Exchange (ETDEWEB)

    Noe, P.; Delafosse, D.; Deletre, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    In order to transport very corrosive products (fluorinated compounds) we have been led to develop a totally metallic circulation pump capable of operating at above room temperatures and with a molecular vacuum. We have aimed at maximum simplicity both in its conception and in its operation. The tests showed that the compression ratios produced, although not high are interesting (1.5 at a pressure of 100 torr) (see curve I). The flow-rate range is very wide: about one hundred ccs/atm/min. to 3000 ccs/atm/min. (see curves IV, V, VI). The desorption of this pump presents no difficulty if both the aspiration and the reject sides are pumped together. A hole of 2 mm diameter drilled in the piston makes it possible to desorb the space between the two segments. The price of this pump is not high: 1300 F, with the electrical cabinet. (authors) [French] En vue de vehiculer des produits tres corrosifs (composes fluores) nous avons ete amene a realiser une pompe de circulation entierement metallique, capable de fonctionner en temperature et sous vide moleculaire. Nous avons recherche la simplicite tant dans sa realisation que dans son fonctionnement. Les essais ont montre que les taux de compression fournis, sans etre eleves, sont interessants (1,5 a la pression de 100 torr) (voir courbe I). La gamme des debits est tres large: d'une centaine de cm{sup 3}/atm/mn a 3000 cm{sup 3}/atm/mn (voir courbes IV, V, VI). La desorption de cette pompe ne presente pas de difficulte en pompant a la fois cote aspiration et cote refoulement. Un percage de 2 mm de diametre dans le piston permet la desorption de l'espace entre les 2 segments. Le cout de cette pompe est peu eleve: 1300 F, coffret electrique compris. (auteurs)

  8. Physico-chemical, textural and structural characteristics of sous-vide cooked pork cheeks as affected by vacuum, cooking temperature, and cooking time.

    Science.gov (United States)

    Sánchez Del Pulgar, José; Gázquez, Antonio; Ruiz-Carrascal, Jorge

    2012-03-01

    This paper describes the influence of different factors on sous-vide cooked pork. Pork cheeks were cooked at different combinations of temperature (60°C or 80°C), time (5 or 12h) and vacuum (vacuum or air packaged). Weight losses were lower and moisture content higher in samples cooked for a shorter time (P=0.054) and at a lower temperature (PVacuum packaging showed no influence on any of the studied variables. For the treatments evaluated, cooking temperature×time combination seems to be more important than vacuum packaging in the textural and colour parameters of pork cheeks.

  9. Qu'est-ce que le care ? Souci des autres, sensibilité, responsabilité, sous la direction de Pascale Molinier, Sandra Laugier et Patricia Paperman

    OpenAIRE

    Raymond, Gilles

    2010-01-01

    Le livre intitulé « Qu'est-ce que le care ? Souci des autres, sensibilité, responsabilité » rassemble huit contributions d'auteurs différents sous la direction de Pascale Molinier, Sandra Laugier et Patricia Paperman sur l'éthique du care. Il est difficile d'en faire une synthèse. Ce sont comme des voix différentes qui exposent certains points essentiels de cette éthique. Toutes ces voix, dont les auteurs sont des femmes, contestent un ordre moral et social pour en revendiquer un autre. Cette...

  10. Acquisition de données en vidéo sous-marine sur les ulves offshore de la baie de Douarnenez

    OpenAIRE

    Lunven, Michel; Le Gall, Erwan; Gaffet, Jean-dominique

    2006-01-01

    En baie de Douarnenez, des estimations du stock d'ulves offshore ont été effectuées en 2004 et 2005 à l'aide de techniques de vidéo sous-marine. Au total, 4 campagnes ont été menées au cours de cette période, permettant une estimation de la biomasse d'ulves posées sur le fond, au-delà de l'estran par des fonds de 2 à 20 mètres.

  11. Développement mobile sous Android (Conception et réalisation d’un jeu en réseau « jeu d’allumettes »)

    OpenAIRE

    2014-01-01

    Nous avons donc réalisé une application Android contenant les fonctionnalités désirés. Ce projet nous a permis de découvrir le SDK Android, avec ses particularités. Cette expérience fut très enrichissante Car la programmation sous Android permet d'utiliser nos connaissances en JAVA dans un nouveau contexte qui est aujourd'hui présent sur de nombreuses plateformes portables (tablettes, Smartphone...etc.). Ainsi notre application est potentiellement portable sur plusieurs type d'appareils fo...

  12. Effect of the cooking method (grilling, roasting, frying and sous-vide) on the oxidation of thiols, tryptophan, alkaline amino acids and protein cross-linking in jerky chicken.

    Science.gov (United States)

    Silva, Fábio A P; Ferreira, Valquíria C S; Madruga, Marta S; Estévez, Mario

    2016-08-01

    Broiler breast (pectoralis major) meat was submitted to salting with NaCl + NaNO3 followed by a drying process to produce jerky-type chicken. The final product (raw broiler charqui) was desalted and then cooked using grilled, roasted, fried and sous-vide techniques. Sous-vide cooked samples showed lowest results of moisture loss compared to roasted and fried ones. Fatty acid profile suffered minor changes after cooking of broiler charqui. Regarding to protein oxidation, tryptophan fluorescence, protein carbonylation and disulphide bonds formation of chicken charqui were affected by cooking temperature while free thiol groups, Schiff base formation and hardness were mostly impacted by the length of cooking. Instrumental color of broiler charqui was affected by the type of cooking, being closely related with Maillard products formation. In conclusion, sous-vide technique seems to be the most advantageous cooking method to obtain high-quality ready-to-eat chicken charqui.

  13. CORROSION ISSUES ASSOCIATED WITH AUSTENITIC STAINLESS STEEL COMPONENTS USED IN NUCLEAR MATERIALS EXTRACTION AND SEPARATION PROCESSES

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.; Louthan, M.; Sindelar, R.

    2012-12-17

    This paper illustrated the magnitude of the systems, structures and components used at the Savannah River Site for nuclear materials extraction and separation processes. Corrosion issues, including stress corrosion cracking, pitting, crevice corrosion and other corrosion induced degradation processes are discussed and corrosion mitigation strategies such as a chloride exclusion program and corrosion release testing are also discussed.

  14. Surface films and corrosion of copper

    Energy Technology Data Exchange (ETDEWEB)

    Hilden, J.; Laitinen, T.; Maekelae, K.; Saario, T.; Bojinov, M. [VTT Manufacturing Technology, Espoo (Finland)

    1999-03-01

    In Sweden and Finland the spent nuclear fuel is planned to be encapsulated in cast iron canisters that have an outer shield made of copper. The copper shield is responsible for the corrosion protection of the canister construction. General corrosion of the copper is not expected to be the limiting factor in the waste repository environment when estimating the life-time of the canister construction. However, different forms of localised corrosion, i.e. pitting, stress corrosion cracking, or environmentally assisted creep fracture may cause premature failure of the copper shield. Of the probable constituents in the groundwater, nitrites, chlorides, sulphides and carbonates have been suggested to promote localised corrosion of copper. The main assumption made in planning this research program is that the surface films forming on copper in the repository environment largely determine the susceptibility of copper to the different forms of localised corrosion. The availability of reactants, which also may become corrosion rate limiting, is investigated in several other research programs. This research program consists of a set of successive projects targeted at characterising the properties of surface films on copper in repository environment containing different detrimental anions. A further aim was to assess the significance of the anion-induced changes in the stability of the oxide films with regard to localised corrosion of copper. This report summarises the results from a series of investigations on properties of surface films forming on copper in water of pH = 8.9 at temperature of 80 deg C and pressure of 2 MPa. The main results gained so far in this research program are as follows: The surface films forming on copper in the thermodynamic stability region of monovalent copper at 80 deg C consist of a bulk part (about 1 mm thick) which is a good ionic and electronic conductor, and an outer, interfacial layer (0.001 - 0.005 mm thick) which shows p-type semiconductor

  15. Corrosion Evaluation of RERTR Uranium Molybdenum Fuel

    Energy Technology Data Exchange (ETDEWEB)

    A K Wertsching

    2012-09-01

    As part of the National Nuclear Security Agency (NNSA) mandate to replace the use of highly enriched uranium (HEU) fuel for low enriched uranium (LEU) fuel, research into the development of LEU fuel for research reactors has been active since the late 1970’s. Originally referred to as the Reduced Enrichment for Research and Test Reactor (RERTR) program the new effort named Global Threat Reduction Initiative (GTRI) is nearing the goal of replacing the standard aluminum clad dispersion highly enriched uranium aluminide fuel with a new LEU fuel. The five domestic high performance research reactors undergoing this conversion are High Flux Isotope reactor (HFIR), Advanced Test Reactor (ATR), National Institute of Standards and Technology (NIST) Reactor, Missouri University Research Reactor (MURR) and the Massachusetts Institute of Technology Reactor II (MITR-II). The design of these reactors requires a higher neutron flux than other international research reactors, which to this point has posed unique challenges in the design and development of the new mandated LEU fuel. The new design utilizes a monolithic fuel configuration in order to obtain sufficient 235U within the LEU stoichoimetry to maintain the fission reaction within the domestic test reactors. The change from uranium aluminide dispersion fuel type to uranium molybdenum (UMo) monolithic configuration requires examination of possible corrosion issues associated with the new fuel meat. A focused analysis of the UMo fuel under potential corrosion conditions, within the ATR and under aqueous storage indicates a slow and predictable corrosion rate. Additional corrosion testing is recommended for the highest burn-up fuels to confirm observed corrosion rate trends. This corrosion analysis will focus only on the UMo fuel and will address corrosion of ancillary components such as cladding only in terms of how it affects the fuel. The calculations and corrosion scenarios are weighted with a conservative bias to

  16. Remote measurement of corrosion using ultrasonic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, K.M.; Porter, A.M.

    1995-02-01

    Supercritical water oxidation (SCWO) technology has the potential of meeting the US Department of Energy`s treatment requirements for mixed radioactive waste. A major technical constraint of the SCWO process is corrosion. Safe operation of a pilot plant requires monitoring of the corrosion rate of the materials of construction. A method is needed for measurement of the corrosion rate taking place during operation. One approach is to directly measure the change in wall thickness or growth of oxide layer at critical points in the SCWO process. In FY-93, a brief survey of the industry was performed to evaluate nondestructive evaluation (NDE) methods for remote corrosion monitoring in supercritical vessels. As a result of this survey, it was determined that ultrasonic testing (UT) methods would be the most cost-effective and suitable method of achieving this. Therefore, the objective for FY-94 was to prove the feasibility of using UT to monitor corrosion of supercritical vessels remotely during operation without removal of the insulation.

  17. Analyses of containment structures with corrosion damage

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, J.L. [Sandia National Labs., Albuquerque, NM (United States)

    1997-01-01

    Corrosion damage that has been found in a number of nuclear power plant containment structures can degrade the pressure capacity of the vessel. This has prompted concerns regarding the capacity of corroded containments to withstand accident loadings. To address these concerns, finite element analyses have been performed for a typical PWR Ice Condenser containment structure. Using ABAQUS, the pressure capacity was calculated for a typical vessel with no corrosion damage. Multiple analyses were then performed with the location of the corrosion and the amount of corrosion varied in each analysis. Using a strain-based failure criterion, a {open_quotes}lower bound{close_quotes}, {open_quotes}best estimate{close_quotes}, and {open_quotes}upper bound{close_quotes} failure level was predicted for each case. These limits were established by: determining the amount of variability that exists in material properties of typical containments, estimating the amount of uncertainty associated with the level of modeling detail and modeling assumptions, and estimating the effect of corrosion on the material properties.

  18. Monitoring corrosion in reinforced concrete structures

    Science.gov (United States)

    Kung, Peter; Comanici, Maria I.

    2014-06-01

    Many defects can cause deterioration and cracks in concrete; these are results of poor concrete mix, poor workmanship, inadequate design, shrinkage, chemical and environmental attack, physical or mechanical damage, and corrosion of reinforcing steel (RS). We want to develop a suite of sensors and systems that can detect that corrosion is taking place in RS and inform owners how serious the problem is. By understanding the stages of the corrosion process, we can develop special a sensor that detects each transition. First, moisture ingress can be monitored by a fiber optics humidity sensor, then ingress of Chloride, which acts as a catalyst and accelerates the corrosion process by converting iron into ferrous compounds. We need a fiber optics sensor which can quantify Chloride ingress over time. Converting ferric to ferrous causes large volume expansion and cracks. Such pressure build-up can be detected by a fiber optic pressure sensor. Finally, cracks emit acoustic waves, which can be detected by a high frequency sensor made with phase-shifted gratings. This paper will discuss the progress in our development of these special sensors and also our plan for a field test by the end of 2014. We recommend that we deploy these sensors by visually inspecting the affected area and by identifying locations of corrosion; then, work with the designers to identify spots that would compromise the integrity of the structure; finally, drill a small hole in the concrete and insert these sensors. Interrogation can be done at fixed intervals with a portable unit.

  19. Corrosion and arc erosion in MHD channels

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, R.J. (Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering); Pollina, R.J. (Montana State Univ., Bozeman, MT (United States). Dept. of Mechanical Engineering EG and G Energy Measurements, Inc., Las Vegas, NV (United States))

    1992-08-01

    The problems connected with gas side corrosion for the design of the lA4 (POC) channel hardware are explored and results of gas side wear rate tests in the Textron Mark VII facility are presented. It is shown that the proposed designs meet a 2000 hour lifetime criterion based upon these materials tests. Improvement in cathode lifetime is demonstrated with lower voltage intercathode gaps. The corrosion of these materials is discussed and it is shown how lifetimes are dependent upon gap voltage and average metal temperature. The importance of uniformity of slagging to the durability of the anode wall is demonstrated. The wear mechanism of the anodes in the MHD channel is analyzed. In addition to gas-side corrosion, the results of specific water corrosion tests of sidewall materials are discussed. All of the tests reported here were carried out to confirm the gas-side performance and the manufacturability of anode and sidewall designs and to address questions posed about the durability of tungsten-copper on the waterside. the results of water corrosion tests of the tungsten copper alloy sidewall material are presented to show that with proper control of waterside pH and, if necessary, dissolved oxygen, one can obtain reliable performance with no degradation of heat transfer with this material. The final choice of materials was determined primarily by the outcome of these tests and also by the question of the manufacturability of the prospective designs.

  20. Handbook of corrosion data, 2nd edition

    Energy Technology Data Exchange (ETDEWEB)

    Craig, B.; Anderson, D. [eds.

    1995-12-31

    As in the prior edition, in one convenient volume this book makes it easy to find what effect environment has on the corrosion of metals and alloys. Coverage on all the environments in the first edition has been updated and expanded and some 80 or more environments have been added, including food products (chocolate, milk, cider, beer, etc.), fruit juices (grape, pineapple, lemon, etc.), soil, blood, gasoline, fertilizers, etc. Presentation of the tabular information for all environments has been standardized throughout the book. The environments are listed alphabetically. Each listing includes a general description of the conditions, a comment on the corrosion characteristics of various alloys in such a situation, a bibliography of recent articles specific to the environment, tables consolidating and comparing corrosion rates at various temperatures and concentrations for various alloys, and graphical information. also included are summaries on the general corrosion characteristics of major metals and alloys. This separate section of the book considers each material group, such as aluminum, stainless steel, zinc and so forth. Additional tables are presented here to give the corrosion characteristics of various alloys in hundreds of environments.