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Materials Sciences and Applications 2015年第8期6卷 760-772页

作者： gerardo zavala olivares Mónica Jazmín Hernández Gayosso Instituto Mexicano Del Petróleo. Eje Central Lázaro Cárdenas Norte Col. San Bartolo Atepehuacan C.P. México D.F. México

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.

关键词： Erosion Corrosion Galvanic Corrosion Microbiologically Induced Corrosion

Steel Pitting Corrosion Analysis, Using a High Vaccum Epoxy Penetration Technique

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Materials Sciences and Applications 2013年第1期4卷 11-13页

作者： gerardo zavala olivares Mónica J. Hernández Gayosso Rafael García Esquivel Instituto Mexicano del Petróleo College of San Bartolo Atepehuacan México City México 2Petroleos Mexicanos Gas y Petroquímica Básica Subdirección de Ductos College of Huasteca México City México

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.

关键词： Pitting Corrosion Analysis Epoxy Injection

Evaluation of Stress Corrosion Cracking Damage to an API 5L X52 Pipeline Transporting Ammonia: A Case Study

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Materials Sciences and Applications 2016年第10期7卷 610-622页

作者： José Luis Mora-Mendoza Mónica Jazmín Hernández-Gayosso Daniel Antonio Morales-Serrat Octaviano Roque-Oms Digna Alejandra Del Angel gerardo zavala-olivares Petróleos Mexicanos Marina Nacional 329 Col. Petróleos Mexicanos CDMX Ciudad de México México Instituto Mexicano del Petróleo Eje Central Lázaro Cárdenas Norte 152 Col. San Bartolo Atepehuacan CDMX Ciudad de México México

The high number of leak events that took place in recent years at a 25.4 cm (10”)Øpipeline 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.

关键词： Stress Corrosion Cracking Residual Stress Ammonia Transporting Pipeline

Corrosion Behavior of API 5L X52 Steel under High Concentrations of H₂S/CO₂ Gases

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Materials Sciences and Applications 2016年第10期7卷 623-643页

作者： Mónica Jazmín Hernández Gayosso gerardo zavala olivares Saúl Bautista Fragoso Gabriel Ernesto Blanco del Valle Daniel Mauricio Godínez Oidor Víctor Ángel Rodríguez Gómez Instituto Mexicano del Petróleo Eje Central Lázaro Cárdenas Norte 152 San Bartolo Atepehuacan Gustavo A. Madero Ciudad de México México Pemex Exploración Producción Carretera Carmen-Puerto Real Km 4.5 Colonia Renovación Edificio Kaxan Campeche México

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.

关键词： H2S Corrosion Cracking Corrosion Inhibition

Identification of Rhizobia Isolated from Nodules of Mexican Commercial Soybean Varieties

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American Journal of Plant Sciences 2024年第1期15卷 29-45页

作者： Cecilia Vázquez Rodríguez Lourdes Vital López Jesús gerardo García olivares Homar Rene Gill Langarica Laboratorio de Biotecnología Vegetal Centro de Biotecnología Genómica Instituto Politécnico Nacional Reynosa México Carrera de Mantenimiento Industrial Universidad Tecnológica de Tamaulipas Norte Universidad Tecnológica Reynosa México

Rhizobia, crucial for nitrogen fixation in leguminous plants, play a vital role in soybean cultivation. This study, conducted in Mexico, a major soybean importer, aimed to identify bacteria from nodules of five soybean varieties in high-production regions. Multilocus sequence analysis (MLSA) was employed for enhanced species resolution. The study identified six Bradyrhizobium species: Bradyrhizobium japonicum USDA 110, Bradyrhizobium japonicum USDA 6, Bradyrhizobium elkanii USDA 76, Bradyrhizobium neotropicale, Bradyrhizobium lablabi, and Bradyrhizobium icense. Bradyrhizobium japonicum USDA 110 predominated in the soils, displaying symbiotic preference for the Huasteca 400 variety. However, phylogenetic analysis didn't reveal a clear association between strains, soil, and soybean variety. This research sheds light on the diversity of rhizobia in Mexican soybean cultivation, contributing to the understanding of symbiotic relationships in soybean production systems.

关键词： Nodules Soybean Housekeeping Genes MLSA Rhizobia Bradyrhizobium Nitrogen Fixation Symbiosis Phylogenetic Analysis

Identification of Rhizobia Isolated from Nodules of Mexican Commercial Soybean Varieties

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Synchronization of Robot Manipulators Actuated By Induction Motors with Velocity Estimator

American Journal of Plant Sciences（美国植物学期刊） 2024年第1期

作者： Cecilia Vázquez Rodríguez Lourdes Vital López Jesús gerardo García olivares Homar Rene Gill Langarica

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Computer Modeling in Engineering & Sciences 2019年第11期121卷 609-630页

作者： Felipe J.Torres gerardo V.Guerrero Carlos D.García Ricardo zavala-Yoe Mario A.García Adolfo R.López University of Guanajuato Division of Engineering Campus Irapuato-SalamancaCarretera Salamanca-Valle de Santiago km 3.5+1.8GuanajuatoSalamanca36885México National Technological of Mexico/National Center of Research and Technological Development Av.Palmira S/N colonia PalmiraMorelosCuernavaca62490México School of Engineering and Sciences Monterrey TechnologicalPuente 222 Ejidos de HuipulcoCiudad de México14380México Superior Technological Institute of Irapuato Carretera Irapuato-Silao km 12.5GuanajuatoIrapuato36821México

A complete modeling(including the actuator dynamics)of a robot manipulator that uses three-phase induction motors is presented in this paper.A control scheme is designed to synchronize robot manipulators actuated by induction motors under a masterslave scheme in the case where the joint velocity of the slave robots is *** of the research on the synchronization of robot manipulators assumes the use of ideal actuators to drive the joints;for that reason,in this work,a three-phase induction motor is considered to be a direct-drive actuator for each *** entire model of the mated system is obtained by a combination of the dynamics of the induction motor and robot ***,the synchronization control algorithm for a master-slave scheme in both the joint space and workspace of robot manipulators driven by induction motors is *** observer based on the entire model is proposed to estimate the joint velocity of the slave robot *** the Lyapunov criterion,a stability analysis of the synchronization control with a velocity estimator is *** analytical results show the synchronization and estimation errors are globally,uniformly,and ultimately *** with multiple robots demonstrate the performance of the proposed control algorithm.

关键词： Synchronization robot manipulator induction motor Lyapunov stability observer based on the model

HP0953-hypothetical virulence factor overexpresion and localization during Helicobacter pylori infection of gastric epithelium

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World Journal of Gastroenterology 2022年第29期28卷 3886-3902页

作者： Nancy K Arteaga-Resendiz gerardo E Rodea Rosa María Ribas-Aparicio Alma L olivares-Cervantes Juan Arturo Castelán-Vega Joséde Jesús olivares-Trejo Sandra Mendoza-Elizalde Edgar O López-Villegas Christian Colín Pamela Aguilar-Rodea Alfonso Reyes-López Marcela Salazar García Norma Velázquez-Guadarrama Laboratorio de Investigación en Enfermedades Infecciosas Hospital Infantil de México Federico GómezMexico City 06720Mexico Posgrado en Biomedicina y Biotecnología Molecular Laboratorio de Producción y Control de BiológicosEscuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalMexico City 11340Mexico Laboratorio de Adquisición de Hierro Universidad Autónoma de la Ciudad MéxicoPosgrado Ciencias GenómicaMexico City 03100Mexico Laboratorio Central de Microscopía Escuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalMexico City 11340Mexico Centro de estudios económicos y sociales en salud Hospital Infantil de México Federico GómezMexico City 06720Mexico Laboratorio de Investigación en Biología del Desarrollo y Teratogénesis Experimental Hospital Infantil de México Federico GómezMexico City 06720Mexico

BACKGROUND The high prevalence and persistence of Helicobacter pylori(H. pylori) infection, as well as the diversity of pathologies related to it, suggest that the virulence factors used by this microorganism are varied. Moreover, as its proteome contains 340hypothetical proteins, it is important to investigate them to completely understand the mechanisms of its virulence and survival. We have previously reported that the hypothetical protein HP0953 is overexpressed during the first hours of adhesion to inert surfaces, under stress conditions, suggesting its role in the environmental survival of this bacterium and perhaps as a virulence *** To investigate the expression and localization of HP0953 during adhesion to an inert surface and against gastric(AGS) *** Expression analysis was performed for HP0953 during H. pylori adhesion. HP0953 expression at 0,3, 12, 24, and 48 h was evaluated and compared using the Kruskal-Wallis equality-of-populations rank test. Recombinant protein was produced and used to obtain polyclonal antibodies for immunolocalization. Immunogold technique was performed on bacterial sections during adherence to inert surfaces and AGS cells, which was analyzed by transmission electron microscopy. HP0953 protein sequence was analyzed to predict the presence of a signal peptide and transmembrane helices, both provided by the ExPASy platform, and using the GLYCOPP platform for glycosylation sites. Different programs, via, I-TASSER, RaptorX, and HHalign-Kbest, were used to perform three-dimensional *** HP0953 exhibited its maximum expression at 12 h of infection in gastric epithelium *** technique revealed HP0953 localization in the cytoplasm and accumulation in some peripheral areas of the bacterial body, with greater expression when it is close to AGS *** analysis revealed the presence of a signal peptide that interacts with the transmembrane region and then allows the release of the protein

关键词： Hypothetical protein HP0953 Adherence Helicobacter pylori Glycocalyx Virulence factor Persistence

Comparison between Classical and Intelligent Identification Systems for Classification of Gait Events

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Journal of Control Science and Engineering 2015年第1期3卷 21-34页

作者： Carlos Galvan-Duque Ricardo zavala-yoe gerardo Rodriguez-Reyes Felipe Mendoza-Cruz MichelinAlvarez-Camacho Ricardo Ramirez-Mendoza Orthotics and Prosthetics Laboratory lnstituto Nacional de Rehabilitacion Mexico City Mexico School of Engineering and Architecture Graduate Studies Tecnologico de Monterrey Mexico City Campus Mexico

Gait event detection is important for diagnosis and evaluation. This is a challenging endeavor due to subjectivity, high amount of data, among other problems. ANFIS （Artificial Neural Fuzzy Inference Systems）, ARX （Autoregressive Models with Exogenous Variables）, OE （Output Error models）, NARX （Nonlinear Autoregressive Models with Exogenous Variables） and models based on NN （neural networks） were developed in order to detect gait events without the problems mentioned. The objective was to compare developed models＇ performance and determinate the most suitable model for gait events detection. Knee joint angle, heel foot switch and toe foot switch during normal walking in a treadmill were collected from a healthy volunteer. Gait events were classified by three experts in human motion. Experts＇ mean classification was obtained and all models were trained and tested with the collected data and experts＇ mean classification. Fit percentage was obtained to evaluate models performance. Fit percentages were： ANFIS： 79.49%, ARX： 68.8%, OE： 71.39%, NARX： 88.59%, NNARX： 67.66%, NNRARX： 68.25% and NNARMAX： 54.71%. NARX had the best performance for gait events classification. For ARX and OE, previous filtering is needed. NN＇s models showed the best performance for high frequency components, ANFIS and NARX were able to integrate criteria from three experts for gait analysis. NARX and ANFIS are suitable for gait event identification. Test with additional subjects is needed.

关键词： Gait analysis biomechanics system identification.

Sperm Quality in Holstein Bulls Friesian and Brahmans of Frozen Semen Commercially

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Open Journal of Animal Sciences 2015年第3期5卷 229-231页

作者： Alejandro Córdova-Izquierdo Gustavo Ruiz-Lang Román Espinosa-Cervantes Adrían Emmanuel Iglesias-Reyes Maximino Méndez-Mendoza Rubén Huerta-Crispín Abel Edmundo Villa-Mancera Ma. De Lourdes Juárez-Mosqueda Pedro Sánchez-Aparicio Jaime olivares-Pérez Juan Eulogio Guerra-Liera gerardo Cansino-Arroyo Departamento de Producción Agrícola y Animal Universidad Autónoma Metropolitana Unidad Xochimilco México D.F. México Facultad de Veterinaria Benemérita Universidad Autónoma de Puebla Puebla México Departamento de Morfología FMVZ-UNAM México D.F. México Facultad de Veterinaria Universidad Autónoma del Estado de México Toluca México Unidad Académica de Medicina Veterinaria y Zootecnia Universidad Autónoma de Guerrero Guerrero México Facultad de Agronomía Universidad Autónoma de Sinaloa Culiacán México División Académica de Ciencias Agropecuarias Universidad Juárez Autónoma de Tabasco Villahermosa México

The aim of this study was to assess sperm quality (motility, viability and acrosomal integrity) sperm from commercially frozen semen straws two breeds of bulls Bos taurus (holstein Frisian) and Bos indicus (Brahman). 9 commercial straws 0.5 ml of Holstein bull semen and 9 Brahman bull were thawed, they were kept for two hours at room temperature and motility, viability and acrosomal integrity (NAR) was assessed. The results were 30% motility, viability 40% and 30% of NAR in the Holstein breed. Brahma race for motility 40%, 50% and 40% viability was obtained NAR. In conclusion, according to the results of the variables analyzed, the Brahman breed in sperm quality was better than the Holstein breed;however, the results of both races meet minimum standards of quality sperm for use in artificial insemination (AI) field level.

关键词： Semen Thawed Bulls Frozen Semen Sperm Quality