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Search Results: 1 - 10 of 400789 matches for " M. Corvo "
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Behaviour of painted aluminium in Ibero-American atmospheres
Morcillo, M.,Simancas, J.,Corvo, F.,Rosales, B.
Revista de Metalurgia , 2003,
Abstract: Aluminium generally presents good corrosion resistance to the atmosphere. However, unprotected aluminium and aluminium alloys weather outdoors to an ugly grey colour, which deepens to black in industrial atmospheres, and undergo superficial pitting in marine atmospheres, etc. Finishing technologies are applied for their protection and decoration in a wide range of applications. These technologies basically consist of two protection processes: anodizing and painting; the latter going from conventional solvent base paints to modem water-borne, high solids and powder coatings. This paper considers the weathering performance of three paint systems: alkyd, polyurethane and polyester, after more than three years of exposure in a wide spectra of Ibero-American atmospheric conditions. The information reported includes resistance to undercutting corrosion at the scribe, filiform corrosion, fungal attack and change in the physical-chemical properties of the paint surface (loss of gloss, colour changes, chalking, etc.). El aluminio, en general, presenta una buena resistencia a la corrosión en la atmósfera. Sin embargo, el aluminio sin ninguna protección y las aleaciones de aluminio expuestas a la intemperie envejecen mostrando un color gris, negro en el caso de atmósferas industriales, sufren la formación de picaduras en atmósferas marinas, etc. Para su protección, o a efectos decorativos, se le aplican diferentes procesos de acabado en un amplio rango de aplicaciones. Estos procesos de acabado, básicamente consisten en dos métodos de protección: anodizado y pintado; este último abarca desde pinturas convencionales de base disolvente hasta modernos sistemas base agua, de alto contenido en sólidos o pinturas en polvo. Este trabajo considera el comportamiento de tres sistemas de pinturas: alquídico, poliuretano y poliéster, tras más de tres a os de exposición en un amplio espectro de condiciones atmosféricas de Iberoamérica. La información presentada incluye la resistencia a la deslaminación en la incisión, corrosión filiforme, ataque por hongos y cambios en las propiedades físico-químicas de la superficie de la pintura (pérdida de brillo, color, entizado, etc.)
Changes in acceleration rate of chloride ions depending on climatic conditions. Influence of rain
Corvo, F.,Arroyave, C.,Autié, M.,Minotas, J.
Revista de Metalurgia , 2003,
Abstract: Mild steel, copper and aluminium samples were exposed outdoors in two atmospheric test stations located in Havana, Cuba and Medellín, Colombia. Two parallel group of samples were formed, one for each station. They were submitted to accelerated outdoor test by intermittent spraying of a salt solution (SCAB test) according to ISO 11474:98, receiving also the influence of the open atmosphere. The acceleration of corrosion rate of the three metals caused by the presence of chloride ions in both stations was determined. As expected, steel shows the higher corrosion rate and acceleration by chlorides, particularly at Cuban corrosion station. A remarkable difference in the acceleration rate of chloride ions for mild steel and copper between Cuban and Colombian acceleration rate of chloride ions of steel and copper. Steel corrosion products were analyzed by M ssbauer Spectroscopy. Water absorption was also studied. The presence of magnetite, goethite and other Iron compounds was determined. Probetas de acero de bajo carbono, cobre y aluminio se expusieron a la intemperie en dos estaciones de ensayo localizadas en la Habana, Cuba y Medellín, Colombia. Se formaron dos grupos paralelos de probetas, tomándose uno para cada estación. Ambos grupos fueron sometidos a ensayos acelerados a la intemperie mediante la aplicación de una niebla salina (SCAB TEST) de acuerdo a la Norma ISO 11474:98, recibiendo también la influencia de la atmósfera abierta. Se determinó la aceleración de la velocidad de corrosión de los tres metales causada por la presencia de iones cloruro en ambas estaciones. Como era de esperar, el acero muestra la mayor velocidad de corrosión y aceleración por los iones cloruro, particularmente en la estación de ensayos cubana. Se determinó una notable diferencia en la velocidad de aceleración provocada por los cloruros para el acero de bajo carbono y el cobre entre las estaciones cubana y colombiana. La influencia de la lluvia parece muy importante en determinar la velocidad de aceleración de los iones cloruro sobre el acero y el cobre. Los productos de corrosión fueron analizados por Espectroscopia M ssbauer. La adsorción del agua fue también estudiada. Se determinó la presencia de magnetita, goetita y otros compuestos de hierro en los productos de corrosión.
PATINA Network - Performance of coil coating in natural atmospheres of Ibero-America
Rosales, B. M.,Di Sarli, A. R.,Fragata, F.,Corvo, F.
Revista de Metalurgia , 2003,
Abstract: The research work performed on 12 coil coating materials in the frame of the PATINA Network (Anticorrosive Protection in the Atmosphere) sponsored by CYTED is discussed. It includs the task accomplished by Science and Technology institutions of Ibero-America on formulations supplied by different prcoduction Sector companies from the participating countries, between 1996 and 2000. Coil coating schemes were exposed outdoors, according to ISO 2810 standards, in 9 ambient conditions of the MICAT (Ibero-American Test Stations Network), CYTED. The protective characteristics on the steel base metal was determined as a function of time, following ISO 4628 and ASTM D 3274 standards. Electrochemical impedance spectroscopy (EIS) was applied on various materials after 1, 2, 3 years and 42 months exposure, to evaluate the weathering effect in different atmospheric conditions. Se discute el trabajo realizado sobre 12 diferentes recubrimientos para banda continua en el marco de la Red PATINA (Protección Anticorrosiva en la Atmósfera), patrocinada por el CYTED. Incluye las actividades llevadas a cabo por instituciones de Ciencia y Técnica de Iberoamérica, sobre distintas formulaciones provistas por empresas productoras de los países participantes, entre 1996 y 1999. Se expusieron a la intemperie, en distintas condiciones ambientales de la Red de Estaciones MICAT, CYTED, siguiendo la norma ISO 2810, recubrimientos de diferentes formulaciones. Se evaluaron las características protectoras sobre el acero de base en función de los parámetros medio-ambientales y los tiempos de exposición programados, según la normas ISO 4628, 4623 y ASTM D 3274. Se aplicaron dos esquemas de protección orgánicos sobre las muestras de acero, otros cuatro sobre muestras de acero previamente protegido con Zn y otros seis sobre acero galvanizado (2) y recubierto con galvalume (4), con y sin incisión en cada esquema hasta llegar el acero. Se discuten los resultados obtenidos al cabo de 1, 2, 3 a os y 42 meses en función de la agresividad de cada sitio de ensayo. Se aplicó espectroscopia de impedancia electroquímica (EIE) al cabo de diferentes períodos de exposición para evaluar la incidencia del deterioro de cada recubrimiento sobre la respuesta global de los esquemas, en varias de las condiciones de ensayo.
Collagenolytic Activities of the Major Secreted Cathepsin L Peptidases Involved in the Virulence of the Helminth Pathogen, Fasciola hepatica
Mark W. Robinson ,Ileana Corvo,Peter M. Jones,Anthony M. George,Matthew P. Padula,Joyce To,Martin Cancela,Gabriel Rinaldi,Jose F. Tort,Leda Roche,John P. Dalton
PLOS Neglected Tropical Diseases , 2011, DOI: 10.1371/journal.pntd.0001012
Abstract: Background The temporal expression and secretion of distinct members of a family of virulence-associated cathepsin L cysteine peptidases (FhCL) correlates with the entry and migration of the helminth pathogen Fasciola hepatica in the host. Thus, infective larvae traversing the gut wall secrete cathepsin L3 (FhCL3), liver migrating juvenile parasites secrete both FhCL1 and FhCL2 while the mature bile duct parasites, which are obligate blood feeders, secrete predominantly FhCL1 but also FhCL2. Methodology/Principal Findings Here we show that FhCL1, FhCL2 and FhCL3 exhibit differences in their kinetic parameters towards a range of peptide substrates. Uniquely, FhCL2 and FhCL3 readily cleave substrates with Pro in the P2 position and peptide substrates mimicking the repeating Gly-Pro-Xaa motifs that occur within the primary sequence of collagen. FhCL1, FhCL2 and FhCL3 hydrolysed native type I and II collagen at neutral pH but while FhCL1 cleaved only non-collagenous (NC, non-Gly-X-Y) domains FhCL2 and FhCL3 exhibited collagenase activity by cleaving at multiple sites within the α1 and α2 triple helix regions (Col domains). Molecular simulations created for FhCL1, FhCL2 and FhCL3 complexed to various seven-residue peptides supports the idea that Trp67 and Tyr67 in the S2 subsite of the active sites of FhCL3 and FhCL2, respectively, are critical to conferring the unique collagenase-like activity to these enzymes by accommodating either Gly or Pro residues at P2 in the substrate. The data also suggests that FhCL3 accommodates hydroxyproline (Hyp)-Gly at P3-P2 better than FhCL2 explaining the observed greater ability of FhCL3 to digest type I and II collagens compared to FhCL2 and why these enzymes cleave at different positions within the Col domains. Conclusions/Significance These studies further our understanding of how this helminth parasite regulates peptidase expression to ensure infection, migration and establishment in host tissues.
Many-core applications to online track reconstruction in HEP experiments
S. Amerio,D. Bastieri,M. Corvo,A. Gianelle,W. Ketchum,T. Liu,A. Lonardo,D. Lucchesi,S. Poprocki,R. Rivera,L. Tosoratto,P. Vicini,P. Wittich
Computer Science , 2013, DOI: 10.1088/1742-6596/513/1/012002
Abstract: Interest in parallel architectures applied to real time selections is growing in High Energy Physics (HEP) experiments. In this paper we describe performance measurements of Graphic Processing Units (GPUs) and Intel Many Integrated Core architecture (MIC) when applied to a typical HEP online task: the selection of events based on the trajectories of charged particles. We use as benchmark a scaled-up version of the algorithm used at CDF experiment at Tevatron for online track reconstruction - the SVT algorithm - as a realistic test-case for low-latency trigger systems using new computing architectures for LHC experiment. We examine the complexity/performance trade-off in porting existing serial algorithms to many-core devices. Measurements of both data processing and data transfer latency are shown, considering different I/O strategies to/from the parallel devices.
Applications of Many-Core Technologies to On-line Event Reconstruction in High Energy Physics Experiments
A. Gianelle,S. Amerio,D. Bastieri,M. Corvo,W. Ketchum,T. Liu,A. Lonardo,D. Lucchesi,S. Poprocki,R. Rivera,L. Tosoratto,P. Vicini,P. Wittich
Computer Science , 2013, DOI: 10.1109/NSSMIC.2013.6829552
Abstract: Interest in many-core architectures applied to real time selections is growing in High Energy Physics (HEP) experiments. In this paper we describe performance measurements of many-core devices when applied to a typical HEP online task: the selection of events based on the trajectories of charged particles. We use as benchmark a scaled-up version of the algorithm used at CDF experiment at Tevatron for online track reconstruction - the SVT algorithm - as a realistic test-case for low-latency trigger systems using new computing architectures for LHC experiment. We examine the complexity/performance trade-off in porting existing serial algorithms to many-core devices. We measure performance of different architectures (Intel Xeon Phi and AMD GPUs, in addition to NVidia GPUs) and different software environments (OpenCL, in addition to NVidia CUDA). Measurements of both data processing and data transfer latency are shown, considering different I/O strategies to/from the many-core devices.
Comparison between the corrosion forecast based on the potential measurement and the determination of the corrosion rate of the reinforcement bar by means of electrochemical techniques
Castaneda, A.,Corvo, F.,O'Reilly, V.
Materiales de Construccion , 2003,
Abstract: The ASTA4 876-91 standard establishes a corrosion forecast of concrete reinforced bar by measuring the electrochemical potential. This forecast is based on thermodynamic considerations without taking into account the kinetic of the corrosion process. A comparison was made between the results obtained based on this standard and others using electrochemical techniques (Tafel, Rp, EIS, Electrochemical Noise). These techniques allows to obtain the corrosion rate in samples having 0.4, 0.5 and 0.66 water/cement ratios submitted to salt spray outdoors and by immersion in 3% saline solution during a test time of 20 months. Differences were detected between the results obtained using the ASTM standard and the electrochemical techniques used. The main difference is that samples submitted to immersion shows a higher probability of corrosion than samples submitted to salt spray; however, the electrochemical techniques showed the contrary concerning the corrosion kinetic process .A comparison respecting corrosion rate was also made between the results obtained by the different electrochemical techniques. It is very well known that all electrochemical techniques supposed always general corrosion except electrochemical noise. Using the technique the pitting index can be calculated. It shows that localized corrosion is the most predominant La norma ASTM 876-91 establece un pronóstico de corrosión de la barra de refuerzo del hormigón armado mediante la determinación de potenciales electroquímicos. Este pronóstico se basa en consideraciones termodinámicas, sin tener en cuenta la cinética del proceso de corrosión. Se comparan los resultados obtenidos aplicando esta norma con técnicas electroquímicas (Tafel, Rp, EIS, Ruido Electroquímico) que permiten calcular la velocidad de corrosión en probetas con relaciones agua/cemento 0,4, 0,5 y 0,66 sometidas a niebla salina en condiciones naturales y en inmersión en solución salina al 3% durante un tiempo de ensayo de 20 meses. Los resultados muestran diferencias entre la aplicación de la norma AST M y las técnicas electroquímicas aplicadas. Esta diferencia consiste en que las muestras sometidas a inmersión dieron como resultado una mayor probabilidad de ocurrencia del fenómeno de corrosión comparadas con la niebla salina; sin embargo, las técnicas electroquímicas demostraron lo contrario en cuanto a la cinética del proceso. Se compararon los resultados obtenidos por las diferentes técnicas electroquímicas en cuanto a la determinación de la velocidad de corrosión. Es conocido que todas las técnicas trabajan suponiendo corrosión g
La actividad de la Caspasa-1 como gen sensibilizador a radio y quimioterapia es independiente de las vías de JNK y p38
Vassaux,G.; Manche?o-Corvo,P.; López-Barahona,M.; Quintanilla,M.; Francisco-álvarez,R.; Hernández-Losa,J.; Lopes,R.; Martín-Duque,P.;
Oncología (Barcelona) , 2005, DOI: 10.4321/S0378-48352005000800004
Abstract: the cytotoxic effect of anticancer drugs has been shown to involve induction of apoptosis. this observation raises the possibility that factors affecting caspase activation might be important determinants as anticancer drug sensitivity. ectopic expression of caspase-1 has been shown to trigger apoptosis. here, we examine the effect of caspase-1 over-expression on the response to chemotherapy and radiotherapy. caspase-1 expression mediated by an adenoviral vector was able to kill directly cells and to sensitize the remaining cells to cisplatin or g-radiation in vitro. in hela cells stably transfected with caspase-1, sensitisation to cisplatin was due to an amplification of the cisplatin-induced mitochondrial apoptotic pathway activation but this effect is independent of p53, jnk or p38 status.
Coadministration of the Three Antigenic Leishmania infantum Poly (A) Binding Proteins as a DNA Vaccine Induces Protection against Leishmania major Infection in BALB/c Mice
Manuel Soto?,Laura Corvo,Esther Garde?,Laura Ramírez?,Virginia Iniesta?,Pedro Bonay?,Carlos Gómez-Nieto?,Víctor M. González?,M. Elena Martín?,Carlos Alonso
PLOS Neglected Tropical Diseases , 2015, DOI: 10.1371/journal.pntd.0003751
Abstract: Background Highly conserved intracellular proteins from Leishmania have been described as antigens in natural and experimental infected mammals. The present study aimed to evaluate the antigenicity and prophylactic properties of the Leishmania infantum Poly (A) binding proteins (LiPABPs). Methodology/Principal Findings Three different members of the LiPABP family have been described. Recombinant tools based on these proteins were constructed: recombinant proteins and DNA vaccines. The three recombinant proteins were employed for coating ELISA plates. Sera from human and canine patients of visceral leishmaniasis and human patients of mucosal leishmaniasis recognized the three LiPABPs. In addition, the protective efficacy of a DNA vaccine based on the combination of the three Leishmania PABPs has been tested in a model of progressive murine leishmaniasis: BALB/c mice infected with Leishmania major. The induction of a Th1-like response against the LiPABP family by genetic vaccination was able to down-regulate the IL-10 predominant responses elicited by parasite LiPABPs after infection in this murine model. This modulation resulted in a partial protection against L. major infection. LiPABP vaccinated mice showed a reduction on the pathology that was accompanied by a decrease in parasite burdens, in antibody titers against Leishmania antigens and in the IL-4 and IL-10 parasite-specific mediated responses in comparison to control mice groups immunized with saline or with the non-recombinant plasmid. Conclusion/Significance The results presented here demonstrate for the first time the prophylactic properties of a new family of Leishmania antigenic intracellular proteins, the LiPABPs. The redirection of the immune response elicited against the LiPABP family (from IL-10 towards IFN-γ mediated responses) by genetic vaccination was able to induce a partial protection against the development of the disease in a highly susceptible murine model of leishmaniasis.
CMS Software Distribution on the LCG and OSG Grids
K. Rabbertz,M. Thomas,S. Ashby,M. Corvo,S. Argirò,N. Darmenov,R. Darwish,D. Evans,B. Holzman,N. Ratnikova,S. Muzaffar,A. Nowack,T. Wildish,B. Kim,J. Weng,V. Büge,for the CMS Collaboration
Computer Science , 2006,
Abstract: The efficient exploitation of worldwide distributed storage and computing resources available in the grids require a robust, transparent and fast deployment of experiment specific software. The approach followed by the CMS experiment at CERN in order to enable Monte-Carlo simulations, data analysis and software development in an international collaboration is presented. The current status and future improvement plans are described.
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