No significant differences were found in bulk density parameter in the entire soil profile. Statistically significant differences. Los animales fueron asignados a 5 grupos y tratados durante 6 semanas. Grupo 1: Aqueous propolis extract is a natural product rich in. Aspergilosis pulmonar secundaria a neutropenia inducida por metimazol: Los cultivos fueron positivos a Aspergillus fumigatus y Aspergillus flavus.
Her regular treatment included methimazole. On admission, laboratory results showed suppressed TSH, elevated free thyroxine, and neutropenia. She was admitted and started on antibiotics and granulocyte-macrophage colony stimulating factor gm-csf. After ten days, the patient developed leukocytosis, fever, and hemoptysis. Chest CT scan showed a lung cavity with multiple nodules in the upper right lobe. Cultures from a lung biopsy were positive for Aspergillus Fumigatus and Aspergillus Flavus.
Amphotericin B was started but then switched to voriconazole, with both treatments failing to result in clinical improvement. The patient died of multi-organ failure. Bank filtration BF consists in obtaining drinking water from wells in alluvial aquifers or other unconsolidated deposits hydraulically connected with a surface water source.
The possibility of applying this technique was evaluated in a pilot scale on the banks of the Lagoa do Peri lagoon, Brazil. Observation and grain size analysis showed that the bottom of the lagoon and the adjacent aquifer have sandy texture. In addition, tests of constant head permeameter, standpipe falling. Osteonecrosis de los maxilares inducida por bifosfonatos: Ante una osteonecrosis establecida, la actitud debe ser conservadora. Bisphosphonate-induced osteonecrosis of the jaws might reach epidemic proportions due to the widespread use of this therapy.
Materials and methods. A protocol for prevention and treatment of this pathology is shown. Three clinical cases are reported. It is quite difficult to reach restitutio ad integrum, but stopping the progress of the disease is possible. Surgical treatment and cessation of bisphosphonate therapy are of no use. Only antibiotics and oral chlorhexidine have shown some benefits. An accurate preventive attitude is mandatory prior to undergoing bisphosphonate therapy. If osteonecrosis of the jaws is present, management should be conservative. The tube and component failures in steam generators due to corrosion cause huge economical losses.
In this article the internal corrosion processes hydrogen attack and high temperature corrosion are described, as well as the ultrasound techniques used for its detection. The purpose is to prevent possible failures that would diminish the power plant availability. En este articulo se describen los procesos de corrosion interna ataque por hidrogeno y corrosion en alta temperatura, asi como tecnicas de ultrasonido empleadas para su deteccion.
Se destaca la importancia de obtener valores de velocidad de corrosion , que es un parametro fundamental para la determinacion de la vida residual de tuberias. El proposito es poder prevenir posibles fallas que disminuyan la disponibilidad de centrales termoelectricas. Corrosion detection and monitoring in steam generators by means of ultrasound; Deteccion y monitoreo de corrosion por medio de ultrasonido en generadores de vapor.
Chacon Nava, Jose G. Interferon-induced autoimmune thyroiditis in a patient with hepatitis C virus infection. En algunos casos se presenta como hipertiroidismo por enfermedad de Graves. A 43 year old man presented with asymptomatic elevation of alanine aminotransferase ALT and no relevant past history.
The patient denied being a chronic alcohol drinker. Work-up revealed an active hepatitis C, and liver biopsy showed active inflammation. Treatment was started with interferon-alfa and ribavirin. During the 48 weeks of treatment, the patient developed positive thyroid antibodies with varying level of thyrotropin TSH and thyroid hormones. Autoimmune thyroiditis is a common complication of using interferon in patients with hepatitis C. Thyroid function and thyroid antibodies should be evaluated before and during treatment with interferon. Arenas-Martinez, L. The corrosion behavior of gas metal arc welding GMAW regions has been studied using potentiodynamic polarization and polarization resistance LPR techniques.
Base metal exhibited the highest corrosion rate CR and the most cathodic corrosion potential. El metal base exhibio la velocidad de corrosion VC mas alta y el potencial de corrosion mas catodico. To describe a nurse experience in providing care for a patient with cancer of the breast and bone metastasis who presented mandibular ostheonecrosis induced by the use of bisphosphonates.
Nursing interventions included the re-enforcement of the guidelines for oral hygiene, highlighting the appropriate teeth-brushing technique, gargling with antiseptic solution without alcohol, as approach to pain management. There is a need for multidisciplinary and nursing consultations for early detection and control of potential complications. 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. Protection against corrosion to high temperature by means of rich silicon coatings; Proteccion contra corrosion a alta temperatura por medio de recubrimientos ricos en silicio. In this research work the study of the process of corrosion by molten salts of sodium sulphate-vanadium pentoxide and its prevention by means of metallic coatings rich in silicon was contemplated. The research encompassed the development of the coating system, the chemical and thermochemical analysis of the system sodium sulphate - vanadium pentoxide, the evaluation of the resistance to the corrosion of the coating system by gravimetric and electrochemistry techniques, and the study of the stability of the coating system - substrate.
La investigacion abarca el desarrollo del sistema de recubrimientos, el analisis quimico y termoquimico del sistema sulfato de sodio - pentoxido de vanadio, la evaluacion de la resistencia a la corrosion del sistema de recubrimientos por tecnicas gravimetricas y electroquimicas, y el estudio de la estabilidad del sistema recubrimiento - sustrato. Los animales se distribuyeron en 4 grupos: Benign prostatic hyperplasia, a common disease in men aged over 50 is characterized by uncontrolled growth of prostatic gland and the presence of low urinary tract symptoms. The oxidative stress has been recently associated with the disease cause.
The D, a lipid extract from Roystonea regia, reduces the. Is there an association between non-steroidal anti-inflammatory drugs and contrast nephropathy? Estudio experimental. Ratas albinas machos adultos y sangre de grado. Los pacientes coronarios tienen un menor nivel preoperatorio de EPC que los valvulares. Full Text Available Heart disease and malignant tumors are the two leading causes of death in Cuba, with mortality rates of ,5 and ,6 per , respectively, in In Cienfuegos, malignant tumors were the leading cause of death with a rate of ,2 followed by heart disease with ,6 per inhabitants.
The improvements in the detection and treatment of cancer have led to a new cohort of patients achieving such a long survival that cardiac complications may appear. Unfortunately, the wide knowledge on biochemical pathways involved in cancer targeted therapy has not been accompanied by a parallel understanding of cardiac consequences of their modulation. The mentioned temperature represents the limit between the two phases, before and after of the precipitation. The activation energy for static recrytallization of the austenite before and after precipitation has also been determined. The present study is completed with the determination of the precipitate size distribution diagrams by means of TEM analysis.
Resistance exercise-induced microinjuries do not depend on 1or 3 minutes rest time interval between series. Las microlesiones inducidas por el entrenamiento con cargas no dependen de los intervalos de descanso entre series de 1 o 3 minutos. Full Text Available AbstractIn order to examine the effects of different rest intervals between sets on the muscle fiber integrity, 14 male subjects volunteered to participate in randomized crossover design methodology. All subjects completed 2 experimental training sessions. Both sessions consisted of 3 sets of 10 repetitions with 10 repetition maximum resistance bench press, cable pulldowns, military press, biceps curl, triceps curl, leg press, leg extension, and lying leg curls.
The 2 experimental sessions differed only in the length of the rest period between sets and exercises: Todos los sujetos realizaron 2 sesiones de entrenamiento con cargas. Meteorites as space probes for cosmic rays; Les meteorites en tant que sondes spatiales pour les rayons cosmiques; Meteority v kachestve prob mezhplanetnogo prostranstva dlya izucheniya kosmicheskikh luchej; Los meteoritos como sondas espaciales para evaluar la actividad inducida por los rayos cosmicos.
Ils comparent ces activites relatives aux taux de production de ces isotopes que l'on obtient en bombardant un echantillon de la meteorite avec des protons ayant une energie de 3 GeV. Les auteurs concluent que, dans les limites d'erreur, le flux de rayons cosmiques est le meme dans la ceinture asteroide que dans le voisinage de l'orbite terrestre. El experimento se basa en el hecho de que los meteoritos siguen orbitas muy excetricas y, por ello, pueden ser utilizados como sondas espaciales en la region situada entre la orbita terrestre y el cinturon de asteroides. La actividad de periodo corto se produce mientras el meteorito se encuentra en las proximidades de la orbita terrestre, en tanto que la actividad de periodo largo es inducida en toda la orbita descrita por el meteorito.
Los autores efectuaron las mediciones en el condrito Hamlet que cayo en Indiana el 13 de octubre de 1.
Evaluaron las actividades astribuibles al argon periodo: Compararon los valores relativos de estas actividades con los indices de produccion de esos isotopos que se alcanzan bombardeando una muestra del meteorito con protones de 3 GeV. Se llega a la conclusion de que la intensidad de la radiacion cosmica es igual, dentro de los limites de error, en el cinturon de asteroides que en las proximidades de la orbita terrestre. Chronically, glucocorticoids induce adverse cardiometabolic alterations including insulin resistance, diabetes, dyslipidemia, liver steatosis and arterial hypertension.
To evaluate the effect of regular practice of aerobic. Se encontraron alteraciones en la estructura de los podocitos. Copolymerization of Ethylene Induced by Cobalt Gamma Radiation; Copolymerisation de l'ethylene induite par des rayons gamma du cobalt; Sopolimerizatsiya ehtilena pod dejstviem gamma-izlucheniya ot istochnika ks'yali; Copolimerizacion del etileno inducida por las radiaciones gamma del cobalto On a procede aux experiences, en milieu statique, dans des systemes a deux phases, a l'exception du systeme ethylene-oxyde de carbone.
La separation des copolymeres a ete obtenue par des methodes d'extraction par solvant et de precipitation fractionnee. L'identification a ete faite au moyen de la spectroscopic aux infrarouges. La composition a ete determinee par analyse elementaire. Les auteurs donnent une evaluation partielle de certains produits de la reaction, y compris les points de fusion cristalline, les densites, les caracteristiques de solubilite et les poids moleculaires.
¿Se puede encontrar temprano el cáncer de tiroides?
La copolymerisation de l'ethylene a ete etablie avec chacun des monomeres suivants: Les auteurs ont trouve que les donnees experimentales obtenues dans l'etude du systeme ethylene-oxyde de carbone suivaient une forme lineaire de l'equation de composition du copolymere.
Los experimentos se llevaron a cabo estaticamente en sistemas bifasicos, salvo en el caso del etileno-oxido de carbono. La separacion de los copolimeros se llevo a cabo por extraccion mediante disolventes y por precipitacion. Os handebolistas foram submetidos a duas baterias de testes: Methodology for the accelerated simulation of the deterioration that by atmospheric corrosion appears in electronic equipment; Metodologia para la simulacion acelerada del deterioro que por corrosion atmosferica se presenta en equipo electronico.
Ortiz Prado, A. The corrosion resistance of systems and electronic parts which are designed to work in atmospheric conditions have been tested for decades; some of these methods were the Cyclic Humidity Test, Field Tests and Salt Spray Fog Testing, the latter was one of the most popular methods. However, the salt spray test and most of the other existing methods do not show strong relationships with the real conditions of service. For this reason, it is necessary to develop appropriated methods and equipment for the accelerated simulation of real atmospheric corrosion phenomena.
This article seeks to demonstrate the need to develop a test and the necessary equipment to reproduce the damage in electronic systems and equipment by atmospheric corrosion. Sin embargo, este y otros que se han elaborado para tal efecto no tienen ninguna relacion con las condiciones reales de servicio, por lo que es necesario un metodo de evaluacion que permita simular de forma acelerada los fenomenos de deterioro por efectos ambientales. Este articulo pretende demostrar la necesidad de desarrollar una prueba, que en forma acelerada, reproduzca el dano que sufre el material por efecto de la atmosfera; el cual se orienta a la evaluacion de equipo electrico y electronico.
C es frecuentemente utilizada como indicador del nivel de stress impuesto por el ejercicio. Las alteraciones de las concentraciones de estas hormonas son las responsables por modular diversas respuestas inducidas por el entrenamiento, como son la hipertrofia y el aumento de la fuerza.
Basic aspects of the carbon dioxide corrosion in oil and gas production; Aspectos basicos de la corrosion por dioxido de carbono en la produccion de petroleo y gas. Corrosion has an important impact inside the oil and gas companies, no only in economics but also in safety, environmental and social aspects. After several decades of investigation of these corrosion processes, there are still several mechanisms not fully understood. Author 19 refs. Las probetas bajo estudio se evaluaron cada 20 dias por medio de espectroscopia de impedancia electroquimica y al final de la prueba se realizaron chequeos visuales y microscopia optica para ver la morfologia de la interface metal-recubrimiento y microespectroscopia Raman para identificar la presencia de posibles productos de corrosion.
Los resultados de impedancia fueron simulados por medio de circuitos electricos equivalentes. Este sistema tuvo durante el tiempo de pruebas un comportamiento excelente con altas resistencias de pelicula y de transferencia de carga y bajas capacitancias de pelicula y de doble capa. Applied methods for mitigation of damage by stress corrosion in BWR type reactors; Metodos aplicados para la mitigacion del dano por corrosion bajo esfuerzo en reactores BWR. Hernandez C, R. The Boiling Water nuclear Reactors BWR have presented stress corrosion problems, mainly in components and pipes of the primary system, provoking negative impacts in the performance of energy generator plants, as well as the increasing in the radiation exposure to personnel involucred.
This problem has caused development of research programs, which are guided to find solution alternatives for the phenomena control. Among results of greater relevance the control for the reactor water chemistry stands out particularly in the impurities concentration and oxidation of radiolysis products; as well as the supervision in the materials selection and the stresses levels reduction. The present work presents the methods which can be applied to diminish the problems of stress corrosion in BWR reactors. Las defensas inducidas en trigos comerciales.
Cracks propagation by stress corrosion cracking in conditions of Boiling Water Reactor BWR ; Propagacion de grietas por corrosion bajo esfuerzo en condiciones de reactor de agua hirviente BWR. This work presents the results of the assays carried out in the Laboratory of Hot Cells of the National Institute of Nuclear Research ININ to a type test tube Compact Tension CT , built in steel austenitic stainless type L, simulating those conditions those that it operates a Boiling Water Reactor BWR , at temperature C and pressure of 8 MPa, to determine the speed to which the cracks spread in this material that is of the one that different components of a reactor are made, among those that it highlights the reactor core vessel.
The application of the Hydrogen Chemistry of the Water is presented HWC that is one alternative to diminish the corrosion effect low stress in the component, this is gets controlling the quantity of oxygen and of hydrogen as well as the conductivity of the water. The rehearsal is made following the principles of the Mechanics of Elastic Lineal Fracture LEFM that considers a crack of defined size with little plastic deformation in the tip of this; the measurement of crack advance is continued with the technique of potential drop of direct current of alternating signal, this is contained inside the standard Astm E Method of Test Standard for the Measurement of Speed of Growth of Crack by fatigue that is the one that indicates us as carrying out this test.
The specifications that should complete the test tubes that are rehearsed as for their dimensions, it forms, finish and determination of mechanical properties tenacity to the fracture mainly they are contained inside the norm Astm E, the one which it is also based on the principles of the fracture mechanics. Respuesta del sistema antioxidante en varones sanos, frente a hiperglicemia aguda inducida.
Sangre y suero de sujetos aparentemente sanos. Theorical and experimental study of the induced forces by the mixed, divergent, convergent and straight labyrinth of seal systems on the steam turbines, gas turbines and compressor rotors; Estudio teorico-experimental de las fuerzas inducidas por los sistemas de sellos de laberinto rectos, convergentes, divergentes y mixtos sobre los rotores de turbinas de vapor, turbinas de gas y compresores.
Por otra parte se recomienda llevar a cabo mas experimentacion con equipo instalado en plantas termoelectricas y en especial en turbinas de vapor con capacidades iguales o superiores a los MW, donde las altas presiones y los sellos localizados en la parte superior de los alabes, vuelven mas susceptibles a las maquinas para autoinducir vibraciones subsincronas. Se la considera una de las causas de factores lesionantes musculares de esqueleto.
El esguince del tobillo es un ejemplo: Se calculan los tiempos de decaimiento del anillo de corriente utilizando distintas aproximaciones de acuerdo con las fases de la tormenta. In a typical event June , solar wind energy rate and total energy dissipation rate in the magnetosphere e and Ut respectively and increased induced currents in a gas pipe located in the auroral zone are studied. For the period geomagnetic indices AE and Dst, and the Bz component of the interplanetary geomagnetic field are analyzed as indicators of the development of the troubled period.
Ring current decay times are calculated using different approaches in accordance with the phases of the storm.
During this period there were significant geomagnetic variations due to geomagnetic substorms and induced currents on the pipeline located in the Otawa River Valley, this fact could produce corrosion increases in its structure. Pitting corrosion behaviour study of aluminium matrix composites A3xx. The influence of the SiCp proportion on the pitting corrosion of A3xx.
The kinetic study was carried out by gravimetric measurements. The corrosion increases with the reinforcement proportion, chloride concentration and copper content. Author 10 refs. Corrosion and corrosion control. Corrosion has always been associated with structures, plants, installations and equipment exposed to aggressive environments.
It effects economy, safety and product reliability.
Monitoring of component corrosion has thus become an essential requirement for the plant health and safety. Protection methods such as appropriate coatings, cathodic protection and use of inhibitors have become essential design parameters. High temperature corrosion , especially hot corrosion , is still a difficult concept to accommodate in corrosion allowance; there is a lack of harmonized system of performance testing of materials at high temperatures.
In order to discuss and deliberate on these aspects, National Association for Corrosion Engineers International organised a National Conference on Corrosion and its Control in Bombay during November , This volume contains papers presented at the symposium. Paper relevant to INIS is indexed separately.
Job lot coupons
Dictionary corrosion and corrosion control. This dictionary has entries in both languages. Keywords and extensive accompanying information simplify the choice of word for the user. The following topics are covered: Theoretical principles of corrosion ; Corrosion of the metals and alloys most frequently used in engineering.
Types of corrosion - chemical-, electro-chemical, biological corrosion ; forms of corrosion superficial, pitting, selective, intercrystalline and stress corrosion ; vibrational corrosion cracking ; erosion and cavitation. Methods of corrosion control material selection, temporary corrosion protection media, paint and plastics coatings, electro-chemical coatings, corrosion prevention by treatment of the corrosive media ; Corrosion testing methods.
Full Text Available Objetivos: Hojas de Piper aduncum, y Rattus norvegicus, cepa Holtzman. Las hojas fueron recolectadas en el distrito de Huariaca, departamento de Pasco. Guerrero C, C. The chromosomal aberrations produced by the ionizing radiation are commonly used when it is necessary to establish the exposure dose of an individual, it is a study that is used like complement of the traditional physical systems and its application is only in cases in that there is doubt about what indicates the conventional dosimetry.
The biological dosimetry is based on the frequency of aberrations in the chromosomes of the lymphocytes of the individual in study and the dose is calculated taking like reference to the dose-response curves previously generated In vitro. A case of apparent over-exposure to alpha particles to which is practiced analysis of chromosomal aberrations to settle down if in fact there was exposure and as much as possible, to determine the presumed dose is presented. Polymerization of sodium methacrylate induced by irradiation; Polimerizacion del metacrilato de sodio inducida por la irradiacion.
Galvan S, A. This work has two objectives, first: Las 20 ratas controles fueron tratadas con aceite. Retinoic acid is an active metabolite of Vitamin A that is teratogenic when present in excess during mammalian embriogenesis. We have investigated the effects of early exposure of rat embryos to retinoic acid on craniofacial structures. Treatment of 45 pregnant Sprague-Dawley rats with mg. Twenty controls were treated only with oil. The fetuses were recovered the day before term, and both morphologic and morphometric analyses of the craniofacial structures were performed.
None of the control fetuses had malformations. Morphometric analyses revealed an increased distance between nasal pores p Respuesta inmune mucosal inducida por proteoliposoma y cocleato derivados de N. Full Text Available Mucosal vaccination offers attractive advantages to conventional systemic vaccination. Most pathogens enter or establish infection at mucosal surfaces. This represents an enormous challenge for vaccine development. Nevertheless, the availability of safe and effective adjuvants that function mucosally is the major limitation. They contain multiple PAMPs as immunopotentiators and have delivery system ability as well as Th1 polarization activity.
High levels of specific IgG antibodies were detected in sera of mice vaccinated with either route. However, specific IgA antibodies were produced in saliva and vaginal wash only following mucosal delivering. In conclusion, the results support the use of AFCo1 as potent Th1 adjuvant for mucosal vaccines, particularly for nasal route.
Muerte celular inducida por condiciones ambientales adversas en Calibrachoa parviflora Petunia. Full Text Available Se ha descrito que condiciones ambientales extremas tales como altas temperaturas, luz ultravioleta y el efecto invernadero, alteran la tasa de crecimiento de las plantas. Para tales efectos, grupos de petunias fueron sometidas a tres condiciones diferentes: Cell death induced by adverse environmental conditions in Calibrachoa parviflora petunia Abstract It has been previously reported that extreme environmental conditions such as high temperatures, ultraviolet light and the greenhouse effect, alter the rate of growth in plants.
In this study we investigated the acute effect of two extreme environmental conditions: For this purpose, a group of petunias was subjected to three different conditions: In continuous observations for up to 72 hours, samples from petals, leaves and stems of each plant were analyzed and after nuclei extraction; these were treated with propidium iodide, a DNA intercalator compound, and analyzed by flow cytometry and fluorescence microscopy.
These results suggest that plants growing in acid soils lose their ability to compensate the stress signal generated as a result of acute exposure to toxic concentrations of sulfuric acid. En pacientes con tratamiento opioide se constata una elevada frecuencia de trastornos gastrointestinales posiblemente relacionados con la DIO, lo que subraya la necesidad de nuevas estrategias para su tratamiento.
Efecto del extracto del fruto de Physalis peruviana "tomatillo" en Mus musculus var. Se utilizaron Mus musculus var. Castorena Gonzalez, J. The corrosion in the reinforcement steel is a problem that diminishes the useful life of reinforced concrete structures, reside committing its structural security. In the available models to estimate the mechanical effect of the corrosion , it is assumed that the corroded steel, through the oxides that grow to its surroundings, exercises a pressure on the surrounding concrete supposing a problem of plane stress or plane strain.
In this work, the problem is modeled with three-dimensional finite element starting from an experiment on a subjected cylinder to accelerated corrosion , with strain gage to measure the pressure indirectly in the interface steel-concrete. From the results obtained it can be concluded that the effect of the length of corroded steel, anodic length, has a significant effect on the magnitude of the pressure in the interface steel-concrete, fact that can be used to improve the existing models. En los modelos disponibles para estimar el efecto mecanico de la corrosion , se supone que el acero corroido, a traves de los oxidos que crecen a su alrededor, ejercen una presion sobre el concreto circundante suponiendo un problema de esfuerzos o deformaciones planas, En el presente trabajo, se modela el problema con elemento finito tridimensional a partir de un experimento sobre un cilindro de concreto reforzado sometido a corrosion acelerada, instrumentado para medir indirectamente la presion en la interfase acero-concreto.
De los resultados obtenidos se concluye que el efecto de la longitud de acero corroido, longitud anodica, tiene un efecto significativo sobre la magnitud de la presion en la interfase acero-concreto, hecho que puede ser utilizado para mejorar los modelos existentes. Full Text Available The phenomenon by which a sinusoidal a.
Thus, a series of electrochemical tests was carried out, when a signal of the previously mentioned characteristics is present in the metal-electrolite interphase, both with cathodic protection and without it. The results allowed to postulate an empirical relationship that determines the corrosive process kinetics exerted by the action of an alternating signal.
The phenomenon by which the AC signal generates a corrosion state over a probe was determined from the physical point of view. Cross-Sections for Low-Energy Neutron-Induced Fission; Sections Efficaces de Fission pour des Neutrons de Faible Energie; d f b d f , b d d e e d e d c d K e d d ; Secciones Eficaces en la Fision Inducida por Neutrones de Baja Energia. Dans le cas d'un noyau cible susceptible de fission thermique, lorsque l'energie des neutrons augmente, la section efficace presente d'abord des variations inversement proportionnelles a la vitesse, puis une region ou des pics de resonance aigus apparaissent, et en dernier lieu une region de continu caracterisee par des variations relativement regulieres.
Tous ces phenomenes peuvent recevoir une explication theorique, mais il semble tres difficile d'expliquer quantitativement certaines caracteristiques des donnees. Lors de mesures recentes de sections efficaces destinees a repondre aux besoins de la technologie des reacteurs, les chercheurs se sont surtout efforces d'ameliorer la resolution en energie ainsi que la precision des donnees relatives aux combustibles; ils ont ete ainsi amenes a etudier plus en detail la region de resonance qui a un grand interet pour les calculs de l'effet Doppler dans les reacteurs.
Des mesures plus precises a des niveaux d'energie assez eleves ont fait apparaitre dans certains cas l'existence de sections efficaces de fission assez importantes en dessous du seuil d'energie de fission. Ces mesures ont ensuite appele l'attention des chercheurs sur l'interpretation des sections efficaces en fonction de modeles nucleaires qui reposent sur des donnees quantitatives sures.
Le memoire expose les principales caracteristiques des sections efficaces de fission par neutrons et en donne une interpretation. Il met l'accent sur les ameliorations qui ont recemment ete apportees a la qualite des mesures et aux essais d'interpretation quantitative de certains aspects des donnees recueillies.
Asimismo, la manera en que estas secciones eficaces varian segun la energia. Study of corrosion in metallic coating in steel-carbon by thermal spray; Estudo de corrosao em revestimentos metalicos em aco-carbono obtidos por aspersao termica. Cruz, Maria C. The effect caused for constituent elements of the watery environment of production of the oil on metallic coverings was studied that simulate the artificial rise of the oil connecting rods of pump mechanic.
Oil well had been raised the resistance characteristics the polarization of the metal when submitted to the watery way surrounding it. They had been evaluated the resistance the covering polarization applied on the steel, with the objective to analyze its resistance the corrosion and to verify the possibility of its use as barrier against the problems originated for the degradation in connecting rods of pump. Radio-tracer techniques in the study of corrosion by molten fluorides; Etude, a l'aide d'indicateurs radioactifs, de la corrosion provoquee par les fluorures fondus; Primenenie metodov radioaktivnykh indikatorov nrn izuchenii korrozii, prichinyaemoj rasplavlennymi ftoristymi soedineniyami; Estudio con indicadores radiactivos de la corrosion ocasionada por fluoruros fundidos.
Ademas, calcularon los coeficientes midiendo los perfiles do concentracion del indicador por pulidos electroliticos sucesivos de las muestras. Los coeficientes globales y los obtenidos por pulido electrolitico concuerdan satisfactoriamente para el Inconel a temperaturas elevadas, y para el lnor-8 a todas las temperaturas.
Los coeficientes medios de difusion encontrados concuerdan siempre con los que se calculan por extrapolacion de los valores publicados, que fueron obtenidos con aleaciones de Cr-Ni similares, a temperaturas mas elevadas. Corrosion cracking. This book presents the papers given at a conference on alloy corrosion cracking.
Topics considered at the conference included the effect of niobium addition on intergranular stress corrosion cracking, corrosion -fatigue cracking in fossil-fueled-boilers, fracture toughness, fracture modes, hydrogen-induced thresholds, electrochemical and hydrogen permeation studies, the effect of seawater on fatigue crack propagation of wells for offshore structures, the corrosion fatigue of carbon steels in seawater, and stress corrosion cracking and the mechanical strength of alloy Corrosion engineering.
This book emphasizes the engineering approach to handling corrosion. It presents corrosion data by corrosives or environments rather than by materials. It discusses the corrosion engineering of noble metals, ''exotic'' metals, non-metallics, coatings, mechanical properties, and corrosion testing, as well as modern concepts.
New sections have been added on fracture mechanics, laser alloying, nuclear waste isolation, solar energy, geothermal energy, and the Statue of Liberty. Special isocorrosion charts, developed by the author, are introduced as a quick way to look at candidates for a particular corrosive. Full Text Available Trolox is a hydrophilic analogue of vitamin E and a free radical scavenger. Ethanol diminishes the amplitude of spontaneous contractions and acetylcholine ACh-induced contractions in rabbit duodenum. The aim of this work was to study the effect of Trolox on the alterations induced by ethanol on contractility and lipid peroxidation in the duodenum.
Trolox increased the reduction induced by ethanol on the amplitude of spontaneous contractions in longitudinal muscle but not in circular muscle. We conclude that Trolox might prevent oxidative stress induced by ethanol in the duodenum. Full Text Available Ratas hembras y machos, de tres meses de edad, fueron separados en dos grupos: Stray current induced corrosion in lightning rod cables of kV power lines towers: Full Text Available With the growth of several areas in modem society, the necessity to generate and carry electrical energy to big cities has greatly increased.
Cables supported by power towers with galvanized steel foundation usually carry energy. As the foundations are underground they may cause high rates of corrosion. It is believed that corrosion results from stray currents that flow through the ground to close the loop between neighboring towers. Stray currents originate in the lightning rod cables of the power line towers, induced by the strong electromagnetic and electric fields of the energized power lines.
The intensity and direction of those currents were measured, indicating substantial values of both their AC and DC components. The potential of the tower ground system, measured in the perpendicular direction of the main axis of the power line, was plotted as a function of the distance to the tower base. The results clearly indicated the tendency to corrosive attack in the anodic towers as reflected by the slope of the plot, whereas no signs of corrosion could be found in the reverse slope, confirming the visual inspection of the foundation.
The profile of the potential plots could be changed providing the electric insulation of the lightning rod cable. Corrosion Engineering. GMI is a small cooperative engineering school of approximately 2, students who alternate between six-week periods of academic study and six weeks of related work experience in…. Los r Corrosion in airframes. 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: 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. Corrosion inhibition. An acid corrosion -inhibiting composition consists essentially of a sugar, and an alkali metal salt selected from the group consisting of iodides and bromides. The weight ratio of the sugar to the alkali metal salt is between 2: The weight ratio of molasses to iodide is greater than about 2: Estudio de la influencia de la refrigeracion con aire de forma natural e inducida en el comportamiento de instalaciones fotovoltaicas.
The presented research provides a deep knowledge of how they work as well as information and results for an improvement in future designs of building integrated photovoltaic systems. Este estudio se centra en analizar la influencia negativa de la temperatura en la produccion electrica de paneles fotovoltaicos al estar emplazados sobre cubierta de acero, como sucede en naves industriales y sobre un invernadero. Se estudian diferentes configuraciones que permitan refrigerar los paneles, reduciendo su temperatura y mejorar su rendimiento.
Para abordar este problema, se han construido dos instalaciones experimentales, fieles a plantas solares en funcionamiento. Una instalacion engloba dos paneles fotovoltaicos sobre estructura fija al suelo. Uno de los paneles esta integrado sobre una superficie paralela y metalica. Entre ambas superficies existe un espacio que posibilita circular aire, permitiendo refrigerar el panel por conveccion natural, o conveccion forzada impulsando el aire con un ventilador.
El otro panel, libre por su cara posterior y se ha considerado de referencia. Se ha estudiado el comportamiento del panel integrado sobre cubierta para diferentes secciones de aire y velocidades inducidas , comparandolo con el panel de referencia. Se ha desarrollado un modelo experimental que nos permite determinar la temperatura del panel en funcion de las variables que influyen en su refrigeracion.
Adicionalmente, se han analizado los datos de una planta solar en funcionamiento, con paneles de igual caracteristicas, obteniendo correlaciones entre la temperatura del panel y las variables electricas y comparandolos con las obtenidas en la instalacion experimental. La segunda instalacion experimental reproduce parte de una instalacion solar sobre un invernadero, formada por cuatro paneles fotovoltaicos colocados sobre el plastico del invernadero, existiendo un canal divergente entre ambas superficies.
Se estudia la. Risk evaluation on internal corrosion of a gas pipeline cut section based on metal mechanic tests and physiochemical analysis of the solids deposited in the pipes; Determinacion del riesgo por corrosion interna de un tramo cortado de una linea de transporte de gas natural a partir de ensayos metalmecanicos y del analisis fisicoquimico de los solidos depositados en la tuberia.
After inspecting a one of the most important pipelines in Colombia, using intelligent tool, the pipe sections were selected that presented losses of thickness which probably they would be risking integrity of the same one and after, these sections were cut and replaced. To one of the cut sections a study with the objective was made him establish the present forms of corrosion and to determine the phenomena that influenced the presence of the damages. For this study were moderate thicknesses of the wall of the tube and was determined the criticality comparing it with its nominal thickness, according to Standard ASME B - 31G.
Taking advantage of the presence solids in the surface, one became both, physical and chemical analysis, DRX and elementary analysis, with the objective to determine its origin and to correlate it with the types of corrosion that were in the line. Then, from all this information the analysis becomes of risks by internal corrosion in pipeline, the plan of mitigation and the plans of monitoring and inspection of the line to avoid the presence of anyone of these forms of corrosion in the future immediate.
Corrosion inhibitors. Four equations were proposed to calculate corrosion inhibition efficiency. The proposed equations were applied to predict the corrosion inhibition efficiency of some related structures to select molecules of possible activity from a presumable library of compounds. Underground pipeline corrosion. 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: The papers in this conference represent the latest technological advances in corrosion control and prevention. The following subject areas are covered: The corrosion behavior of AZ31B magnesium alloy modified by friction stir processing FSP was studied in simulated marine environment, in order to determine the effect of process variables rotation speed and travel speed. The corrosion analysis was carried upon by means of electrochemical impedance spectroscopy and potentiodynamic polarization curves Tafel, metallographic analysis of the welded zones was done by optical microscopy and the chemical analysis of the corrosion products were done by using scanning electron microscope SEM, equipped with EDS analyzer.
Investigation of the corrosion resistance of TiNbZr alloy by electrochemical techniques and surface analysis; Investigacao da resistencia a corrosao da liga TiNbZr por meio de tecnicas eletroquimicas e de analise de superficie. In this work, the in vitro corrosion resistance of the TiNbZr alloy, manufactured at a national laboratory, and used for orthopedic applications, has been investigated in solutions that simulate the body fluids.
The electrolytes used were 0. The aim of peroxide addition was to simulate the conditions found when inflammatory reactions occur due to surgical procedures. The corrosion resistance of alloys commercially in use as biomaterials, Ti-6Al-7Nb and Ti-6Al-4V, as well as of the pure titanium Ti-cp , was also studied for comparison with the TiNbZr alloy. The corrosion resistance characterization was carried out by electrochemical and surface analysis techniques. The electrochemical tests used were: The impedance experimental diagrams were interpreted using equivalent electric circuits that simulate an oxide film with a duplex structure composed of an internal and compact, barrier type layer, and an external porous layer.
The results showed that the corrosion resistance is due mainly to the barrier type layer. The titanium alloys and the Ti-cp showed high corrosion resistance in all electrolytes used. The results showed that the presence of hydrogen peroxide in MEM promotes the growth of the porous layer and incorporation of mineral ions, besides favouring hydroxyapatite formation. The cytotoxicity of the TiNbZr alloy was also evaluated and it was shown to be non-toxic. Aircraft Corrosion.
Corrosion Testing Facility. It is a fully functional atmospheric exposure site, called the Corrosion Instrumented Test La hoja de coca ha sido usada tradicionalmente con fines medicinales y contiene altos niveles de hierro. Corrosion technology. This book has been produced for dissemination of information on corrosion technology, corrosion hazards and its control. Chapter one of this book presents an overall view of the subject and chapter deals with electrochemical basics, types of corrosion , pourbaix diagrams and form of corrosion.
The author hopes it will provide incentive to all those interested in the corrosion technology. The approximately papers from this conference are divided into the following sections: Papers have been processed separately for inclusion on the data base. Characterization and corrosion behavior of phytic acid coatings, obtained by chemical conversion on magnesium substrates in physiological solution; Caracterizacion y comportamiento frente a la corrosion de recubrimientos de acido fitico, obtenidos por conversion quimica, sobre substratos de magnesio en solucion fisiologica.
Hernandez-Alvarado, L. In order to improve the corrosion resistance of biodegradable magnesium and AZ31 magnesium alloy implants, a phytic acid coating has been applied on both substrates and their protective effect against corrosion has been assessed. The spectra showed that the conversion coating was amorphous, and it was composed of Mg, O, and P on magnesium surface, along with Al, Zn and C on AZ31 alloy. The main coating components were chelate compounds formed by phytic acid and metallic ions. The corrosion resistance of bare and coated samples was evaluated by potentiodynamic polarization technique in Hank's solution at 37 degree centigrade.
The results indicate that phytic acid conversion coatings provided a very effective protection to the magnesium substrates studied. Evaluation of the susceptibility to corrosion by pites of supermartensitic stainless steel with different superficial finishing; Avaliacao da susceptibilidade a corrosao por pites do aco inoxidavel supermartensitico com diferentes acabamentos superficiais.
It was also observed that the material showed less susceptibility to pitting corrosion when its surface was less rough. Accelerated Corrosion Testing. Treaty Organization, Brussels, , p. Sprowls, T. Summerson, G. Ugianski, S. Epstein, and H. Craig , Jr. Hishida and H. Nakada, Corrosion 33 11 Deegan and B.
Wilde, Corrosion 34 6 , 19 Orman, Corrosion Sci. Topics covered by this conference include: Over papers from this conference have been processed separately for inclusion on the data base. Evaluation and mitigation of the degradation by corrosion in the components of the service water system of a nuclear power plant; Evaluacion y mitigacion de la degradacion por corrosion en los componentes del sistema de agua de servicio de una planta nuclear.
Salaices A, E. Reforma Col. Palmira, Cuernavaca, Morelos Mexico ]. One of the main problems that face the nuclear power stations is the degradation by corrosion in the service water systems. The corrosion causes lost substantial in energy generation and a high cost in maintenance and repairs. In this work, the results of a study of the degradation by the MIC mechanisms microorganisms influenced corrosion , incrustations in heat exchangers and erosion for solid particles in the components of a typical service water system of a nuclear plant are presented.
Diverse mitigation options are analyzed for these mechanisms. The results are presented in susceptibility indexes and degradation rates component-by-component. A significant decrement could be observed in the susceptibility to MIC when changing the operation conditions of stagnated flow to continuous flow. With respect to the erosion by solid particles, it was found a significant reduction of the damage it when adding filters to the system. Finally, in the case of the heat exchangers, it is shown that one of the more viable options to diminish incrustations and existent calcium deposits it is the reduction of the pH of the service water.
Polymer coatings have been widely considered as a solution in the protection of metallic substrates against both wear and corrosion. Thermal spray technology allows the deposition of polymers onto several substrate materials for various thicknesses at several environmental conditions. Thermal sprayed polymers have high potential for material cost reduction as well as to improve coating performance in drastic environments.
In this work, poly-ether-ether-ketone PEEK and Polyamide 12 were flame sprayed on carbon steel substrates. High quality coatings were obtained. Several tests were carried out to evaluate the coatings mainly related to wear and corrosion performance. According to the obtained results, it can be stated that the studied coatings can be successfully used in applications involving wear and corrosion , with a slight edge.
Rehabilitation of the gas pipeline that had a rupture in service caused by SCC Stress Corrosion C raking ; Rehabilitacion al servicio de un gasoducto que ha sufrido una ruptura en servicio por SCC. After initial evaluation of the causes of the rupture it was concluded that it had been caused by Stress Corrosion Cracking SCC. Subsequent investigation in the area of the rupture revealed that colonies of cracks, typical of SCC were found in pipes located near the rupture.
In order to put back in service the pipeline in a safety condition, SCC mitigation activities were performed. A decision was made to conduct a hydro test along approximately 30 kilometers of pipe. The stages of the works, the problems faced and the solutions found are dealt with, as well as the conclusions reached upon completion of the works which allowed a better understanding of SCC phenomenon. The methodology for the identification of those areas susceptible to SCC is also described. For the finite element analysis the software ANSYS was used, which has the element SOLID65, with which is possible to model plain concrete, since has the capacity to show crushing in compression and to cracking in tension.
The obtained model is in function of the free cover, diameter of the. Catastrophes caused by corrosion. For many years, huge attention has been paid to the problem of corrosion damage and destruction of metallic materials. Significant funds are determined annually for the prevention and control of corrosion Modelling of Corrosion Cracks. 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 Nevertheless, the stability of this layer was considerably affected by increasing the concentration of chloride ions causing that localized corrosion has taken place in some areas of the surface of API 5L X42, which were detected by electrochemical noise technique. Estudio experimental completo. Se emplearon 30 ratas Holtzman macho de 12 semanas de edad, aleatorizadas y divididas en seis gru- pos: Erosion- corrosion. 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. Microbiological corrosion of metals. Problems is considered of development of the microbiological corrosion of the NPP equipment. The main attention is paid to the selective character of microbiological corrosion in zones of welded joints of austenitic steels.
It is noted that the presence of technological defects promotes growth of corrosional damages.
- ¿Se puede encontrar temprano el cáncer de tiroides?.
- Free Job lot coupons?
- joe hubers coupons?
- Pats coupon code.
- cvs coupon passport picture;
- yepme hot deals!
Methods for microbiological corrosion protection are discussed. Management of Reinforcement Corrosion. 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 Ratas albinas cepa Holtzmann machos. Corrosion of metallic materials. Dry corrosion , aqueous corrosion and corrosion by liquid metal, methods of protection. This book is based on a course on materials given in an engineering school.
The author first gives an overview of metallurgy issues: The second part addresses the properties and characterization of surfaces and interfaces: The third chapter addresses the electrochemical aspects of corrosion: The fourth part addresses the different forms of aqueous corrosion: The sixth chapter addresses the struggle and the protection against aqueous corrosion: The last chapter proposes an overview of corrosion types in industrial practices: Fighting corrosion in India.
A survey covers the cost of corrosion in India; methods of preventing corrosion in industrial plants; some case histories, including the prevention of corrosion in pipes through which fuels are pumped to storage and the stress- corrosion cracking of evaporators in fertilizer plants; estimates of the increase in demand in for anticorrosion products and processes developed by the Central Electrochemical Research Institute CECRI at Karaikudi, India; industries that may face corrosion problems requiring assistance from CECRI, including the light and heavy engineering structural, and transport industries and the chemical industry; and some areas identified for major efforts, including the establishment of a Corrosion Advisory Board with regional centers and the expansion of the Tropical Corrosion Testing Station at Mandapam Camp, Tamil Nadu.
Full Text Available Objetivo. This chapter examines the important strategies provided by the newer ideas of corrosion science and engineering that surface modification techniques must utilize to help prevent corrosion , especially the most damaging kind of aqueous corrosion , localized corrosion. Provides a brief introduction to the principles underlying the phenomenon of corrosion in order to use them to discuss surface modification strategies to combat corrosion.
Discusses the electrochemistry of corrosion ; the thermodynamics of corrosion ; the kinetics of corrosion ; thermodynamic strategies; and kinetic strategies formation of more protective passive films; resistance to breakdown; ductility; repassivation. Many hot corrosion problems in industrial and utility boilers are caused by molten salts. The corrosion processes which occur in salts are of an electrochemical nature, and so they can be studied using electrochemical test methods.
In this research, electrochemical techniques in molten salt systems have been used for the measurements of molten corrosion processes. To establish better the electrochemical corrosion rate measurements for molten salt systems, information from electrochemical potentiodynamic polarization curves, such as polarization resistance and Tafeol slopes were used in this study to generate corrosion rate data. The salt was contained in a quartz crucible inside a stainless retort.
The atmosphere used was air. A thermocouple sheathed with quartz glass was introduced into the molten salt for temperature monitoring and control. Two materials were tested in the molten mixture: The corrosion rates values obtained using electrochemical methods were around 0. The corrosion rate increase with time. Author 7 refs. The aim of this work was to analyze the dominance patterns of the circulation of the human heart, the number of branches from the right coronary artery to the left ventricle, the number of branches from the left coronary artery to the right ventricle and the frequency and location of intercoronary anastomoses.
Casts were made of 25 hearts by the injection of colored acrylic resin and subsequent corrosion using hydrochloric acid at the experimental surgery laboratory of Furb. Specimens with lesions or scars were discarded. Determinar el efecto hipoglicemiante y antioxidante de la harina de maca Lepidium meyenii Walp del ecotipo amarillo, en ratas con diabete Durante el desarrollo prenatal los organismos son vulnerables a factores que pueden afectar su homeostasis.
Jan Mar This paper shows that under absence of arbitrage opportunities the exchange rate reacts to restore equilibrium in international bond markets. The key factors determining its value are the difference between realized and implicit interest rate differentials, the underlying risk premium in bond markets and changes in market expectations on the long r Optimal currency carry trade strategies. Sep Jun Full-text available. We find that, with Optimal combination of currency strategies. Nov