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Search Results: 1 - 10 of 563433 matches for " Mónica Jazmín Hernández Gayosso "
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Corrosion of Steel Pipelines Transporting Hydrocarbon Condensed Products, Obtained from a High Pressure Separator System: A Failure Analysis Study  [PDF]
Gerardo Zavala Olivares, Mónica Jazmín Hernández Gayosso
Materials Sciences and Applications (MSA) , 2015, DOI: 10.4236/msa.2015.68078
Abstract: In this paper, the corrosion of steel pipelines transporting hydrocarbon condensed products was studied. Different activities of sampling and analysis were carried out to diagnose the failure causes and to establish a control system for the corrosion problem. The combination of three types of corrosion, including erosion corrosion, galvanic corrosion and microbiologically induced corrosion, was synthetically considered. A serial of experiments were designed to research those types of corrosion. This type of failure was observed in characteristics sites of the pipeline, mainly in direction changes and welding joints. Additionally, localized corrosion was observed in the inner steel wall and distributed along the pipeline, although a tendency was not detected.
Corrosion Behavior of API 5L X52 Steel under High Concentrations of H2S/CO2 Gases  [PDF]
Mónica Jazmín Hernández Gayosso, Gerardo Zavala Olivares, Saúl Bautista Fragoso, Gabriel Ernesto Blanco del Valle, Daniel Mauricio Godínez Oidor, Víctor ángel Rodríguez Gómez
Materials Sciences and Applications (MSA) , 2016, DOI: 10.4236/msa.2016.710051
Abstract: In the present work, the susceptibility of API 5L X52 steel to corrosion processes was evaluated in the presence of high contents of hydrogen sulfide and carbon dioxide. Gravimetric tests and surface analyses were carried out to establish both the corrosion rate and damage type exhibited by the metal. The obtained results indicate that the hydrogen sulfide is the most active gas in the corrosion processes that took place, quite above carbon dioxide. The main observed corrosion products were iron sulfides and the typical damage associated with hydrogen sulfide presence was Sulfide Stress Cracking (SSC). The surface damage evidences the presence of cracks with considerable magnitude and metal loss as consequences of the corrosion processes. Likewise, the presence of oxygen in the system modifies the displayed corrosion type, where corrosion products such as iron oxides and reduction in the number and extent of cracks are observed. On the other hand, the addition of a film-forming corrosion inhibitor based on modified imidazolines eliminates completely the development of cracks, although under certain test conditions, it can favor localized pitting corrosion.
Evaluation of Stress Corrosion Cracking Damage to an API 5L X52 Pipeline Transporting Ammonia: A Case Study  [PDF]
José Luis Mora-Mendoza, Mónica Jazmín Hernández-Gayosso, Daniel Antonio Morales-Serrat, Octaviano Roque-Oms, Digna Alejandra Del Angel, Gerardo Zavala-Olivares
Materials Sciences and Applications (MSA) , 2016, DOI: 10.4236/msa.2016.710050
Abstract: The high number of leak events that took place in recent years at a 25.4 cm (10”)Ø pipeline transporting anhydrous liquid ammonia, located in the Southeast of Mexico, was the main reason to carry out a number of field studies and laboratory tests that helped establish not only the failure causes but also mitigation and control solutions. The performed activities included direct evaluation at failure sites, total repair programs, metallographic studies and pipeline flexibility analyses. The obtained results were useful to conclude that the failures obeyed a cracking mechanism by Stress Corrosion Cracking (SCC) which was caused by the combined effect of different factors: high stress resistance, high hardness of the base metal with a microstructure prone to brittleness and residual strains originated during the pipeline construction. From the operative, logistic and financial standpoints, it is not feasible to release the stress of approximately 22 km of pipeline. Therefore, the only viable solution is to install a new pipeline with suitable fabrication, construction and installation specifications aimed at preventing the SCC phenomenon.
Steel Pitting Corrosion Analysis, Using a High Vaccum Epoxy Penetration Technique  [PDF]
Gerardo Zavala Olivares, Mónica J. Hernández Gayosso, Rafael García Esquivel
Materials Sciences and Applications (MSA) , 2013, DOI: 10.4236/msa.2013.41002

An epoxy penetration technique was used to reproduce and analyze the pitting corrosion process occurred at a steel coupon surface. The samples were exposed to the resin under high vacuum conditions, in order to fulfill the pits caused by the corrosion process. With this technique, a 3D image of the corrosion damages was obtained. Once the image of the damaged surface was obtained, a Scanning Electron Microscope (SEM) was used to analyze the morphology of the pits exhibited by the steel sample. The results were satisfactory, as different parameters such as the diameter, shape and depth of the pits originated, along with the corrosion preferential path, could be established. According to the results, the use of the epoxy penetration technique may be considered as alternating pitting corrosion analysis technique.

Micosis observadas en cinco comunidades mexicanas con alto grado de marginación
Méndez-Tovar, Luis J.;Anides-Fonseca, Adriana;Vázquez-Hernández, Aarón;Galindo-González, Martha;Díaz-Madrid, Mónica;Berdón-Castro, Antonio;Manzano-Gayosso, Patricia;Millán-Chiu, Blanca;Hernández-Hernández, Francisca;López-Martínez, Rubén;
Gaceta médica de México , 2006,
Abstract: background. in many small rural communities in mexico, medical care is deficient, empirical or absent. objetive. in order to improve health coverage in rural areas, the mexican institute of social security organizes medical and surgical meetings of various specialties including dermatology and mycology (msdm). these include visits to rural hospitals by dermatologists and a mycologist to care for underprivileged communities. in addition to taking samples, they establish the clinical diagnosis and indicate medical and/or surgical treatment, with follow-up visits when needed. material and methods. in 2004 and 2005, five msdm in chiapas (two), puebla (one), michoacán (one) and oaxaca (one) were organized mycoses were within the first four skin pathologies detected. results. direct examination with potassium hydroxide led to the diagnosis of mycosis andotherskin diseases such as scabies, pediculosis or hair disorders. the sample cultures showed, in addition to common fungi as dermatophytes (trichophyton rubrum, 19 cases), other uncommon fungal agents such as trichosporon spp, chrysosporium spp, cryptococcus, geotrichum spp and aspergillus spp. most of the candidiasis cases were caused by candida parapsilosis (nine cases) followed by c. albicans (three cases).
Atresia tricuspídea asociada a tronco común. Reporte de un caso
Ramírez Ramírez, Lizeth;Lázaro Castillo, José Luis;Gayosso Domínguez, Araceli;Manrique Valle, Mónica;Carpio Hernández, Juan Carlos;Munayer Calderón, Jaime;Aguilar Arteaga, Lucía;Arellano Ostoa, David;
Archivos de cardiología de México , 2008,
Abstract: the tricuspid atresia associated with persistent truncus arteriosus is a rare anomaly. a case is presented of one male patient of three months age in which was detected a cardiac murmur. the diagnosis was made by echocardiography and confirmed by cardiac catheterization. the first step of the palliation was done with disconnection of the trunk of the pulmonary artery combined with a systemic- to- pulmonary shunt of 4 mm. the patient died 24 hours later for persistent metabolic acidosis.
Inmunoglobulinas en pacientes con actinomicetoma por Nocardia brasiliensis
Méndez-Tovar,L. J.; Mondragón-González,R.; Manzano-Gayosso,P.; López-Martínez,R.; Hernández-Hernández,F.; Bonifaz,A.; Anides Fonseca,A.; Araiza,J.; Vega-López,F.;
Revista argentina de microbiolog?-a , 2004,
Abstract: considering that some authors have reported an increasing of some immunoglobulins in actinomycetoma patients, in this study we propose to determine differential production of igg1, igg2, igg3, igg4 and iggm in 25 patients with actinomycetoma and 25 healthy individuals from a mycetoma endemic area. immunoglobulins were determined by elisa technique. to sensibilize the plates, six nocardia brasiliensis antigens were used: a crude antigen denominated nb and five derivatives (nb2, nb4, nb6, nb8 and nb10) obtained by their isoelectric point. results showed that all igg subclasses were higher in the patients’ sera than in control sera, with a maximal difference to igg3 and igg4. to the latter subclass, six antigens were highly reactives. igm levels were similar in both groups. as it occurs in other infections, in the actinomycetoma pathogenesis probably participate the increase or deficiency of a determined immunoglobulin class, as well as the relationship between different subclasses.
Phaseolus Genetic Resources Grown in Campeche, Mexico  [PDF]
Fermín Orona-Castro, Rogelio Lépiz-Ildelfonso, Juan Medina-Mendez, Mónica Guadalupe Lozano-Contreras, Mirna Hernández Pérez
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.612142
Abstract: The protein intake of the population in the Yucatan Peninsula is based upon the different forms of beans naturally developed. The different ecotypes of creole beans that are grown traditionally have been displaced by improved varieties, thereby turning into a risk of losing a valuable source of germ-plasma. The present study is aimed to identify, collect and preserve several bean species genetic resources grown in Campeche, Mexico, in addition to the development of an identification card with the main phenotypic characteristics and yield components. A total of 33 different samples were collected from nine different municipalities statewide; out of those, 15 were Phaseolus vulgaris and 18 Phaseolus lunatus. The collected samples diversity is reflected in the range of growth habits from the bush to the indeterminate climbing species, being these the most representative with about 29 samples, many of those because of the way the planting is carried out, which is traditionally performed in association with the cultivation of corn. Early samples were identified in this diversity with their cycle ranging from 60 to 120 days after emergence. Samples of Phaseolus lunatus with 1.35 to 2.86 t/ha yield potential were also obtained.
Algoritmos para la determinación de soluciones en problemas de programación por metas fraccionales.
Caballero Fernández, Rafael,Hernández Huelin, Mónica,Gómez Nú?ez, Trinidad
Rect@ , 2009,
Abstract: RESUMEN En este trabajo se resuelve el problema de Programación por Metas cuando las metas adoptan una forma fraccional lineal. La principal dificultad de este problema viene dada porque en el modelo de programación matemática que se ha de resolver para buscar soluciones que satisfagan los niveles de aspiración, surgen restricciones no lineales. Cuando existen soluciones que satisfacen todos los niveles de aspiración, el problema resulta fácil de resolver a través de la resolución de un problema lineal asociado. En este trabajo proponemos algoritmos para resolver este problema cuando no tenemos asegurada la existencia de dichas soluciones. Este estudio será llevado a cabo teniendo en cuenta todos los distintos enfoques de resolución de un problema de Programación por Metas, estableciendo algoritmos de búsqueda de las soluciones bajo todos estos enfoques, así como un análisis de sensibilidad de los niveles de aspiración.ABSTRACT This work deals with the resolution of the goal programming problem with linear fractional criteria. The main difficulty of these problems is the non-linear constraints of the mathematical programming models that have to be solved. When there exist solutions satisfying all target values, the problem is easy to solve by solving a linear problem. So, in this paper we deal with those instances where there is no guarantee such solutions exist, and therefore we look for those points in the opportunity set closest to the target values. This study has been done taking into account all the different approaches available for solving a goal programming problem, creating solution-search algorithms based on these approaches, and performing a sensitivity analysis of the target values.
Presence of Risk Factors and Co-Factors for Acquiring HPV Infection or Cervical Cancer in Women Living in a Rural Area and an Urban  [PDF]
Terán-Figueroa Yolanda, Canúas-Landero Víctor Gabriel, Ramírez-Flores élfego, Hernández-Madrigal Mónica, Gallegos-García Verónica, Gutiérrez-Enríquez Sandra Olimpia
Health (Health) , 2014, DOI: 10.4236/health.2014.68088
Abstract: Objective: Identify the presence of some risk factors and co-factors for acquiring HPV (human papilloma virus) or cervical cancer in women from a rural area and an urban area. Material and Methods: Cross-sectional study conducted in 2008 in the State of San Luis Potosí, México. Sampling of non-probabilistic convenience was applied. 99 women participated (73 from urban area and 26 rural). Two surveys were used to identify risk factors and socio-demographic data. All women underwent HPV testing; the samples were self-collected and processed by the Hybrid Capture II method?. To analyze the data, descriptive and inferential statistics were applied. Results: The predominant age range was 37 to 42 years. 38.5% is in a rural community and an urban 37.3%. 72.6% began their sexual life at 19 years or more in urban areas and 57.6% before 18 in rural areas. In relation to the number of sexual partners reported having had only one, 73.1% and 67.1% in rural and urban area respectively. Risk factors that were associated with HPV infection were the beginning of sexual activity at age 18 and under (p = 0.041) and the number of sexual partners (p = 0.001). Conclusions: There are more risk factors in women in urban areas but in rural areas it had the highest percentage of positive cases for infection by high-risk HPV.
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