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Search Results: 1 - 10 of 49133 matches for " Daniel Santamaria del Angel "
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Effect of Nicotine on Dopamine and Glutathione Levels in Presence of Oligoelements in Brain Regions of Young Rats——Effect of Nicotine on Brain Regions of Rat  [PDF]
David Calderón Guzmán, Ernestina Hernández García, Francisca Trujillo Jiménez, Gerardo Barragán Mejía, Hugo Juárez Olguín, José A. Saldivar González, Daniel Santamaria del Angel, Norma Osnaya Brizuela
Neuroscience & Medicine (NM) , 2012, DOI: 10.4236/nm.2012.33032
Abstract: Aim: The purpose of this study was to understand the mechanism of nicotine mediated addiction and the role of oligoelements in reducing its effect. Methods: Male Wistar rats (weight 80 g) were treated with single and repeated doses of nicotine and/or oligoelements as follows: group 1 (control) NaCl 0.9%; group 2, nicotine (1 mg/kg); group 3, oligoelements (50 μl/rat); and group 4, nicotine (1 mg/kg) + oligoelements (50 μl/rat). All drugs were intraperitoneally administered for 4 days. Blood for the measurement of glucose was obtained from all the animals. Samples of the brain regions (cortex, hemispheres and cerebellum + medulla oblongata) of each rat were obtained and used to measure the concentrations of dopamine, GSH levels, and lipid peroxidation (TBARS) using fluorescence and spectrophotometric methods. Results: Glucose level increased in rats treated with nicotine and oligoelements (p < 0.05), while GSH level decreased in cerebellum/medulla oblongata and hemispheres (p < 0.05) of the same animals. TBARS levels increased in cerebellum/medulla oblongata and hemispheres of animals treated with nicotine and oligoelements, but decreased in the same regions (p < 0.05) in rats treated only with oligoelements. The levels of dopamine decreased in cortex and hemispheres, but increased in cerebellum/medulla and oblongata regions of rats treated with both compounds (p < 0.05). Conclusions: Nicotine and oligoelements are associated with increase in the level of glucose, an effect that was more pronounced in the group treated with both drugs. Reduction of oxidative stress and dopamine metabolism may be involved in this effect.
Assessment of the Abundance of Yellowfin Tuna in the Gulf of Mexico
Daniel J. Fonseca,Daniel Zavala,Eduardo Del Angel Rincon
Journal of Animal and Veterinary Advances , 2012,
Abstract: This paper presents the application of a statistical model for predicting yellowfin tuna fish abundance in the Gulf of Mexico. Data for twelve different independent variables was collected through sensors installed in various space satellites, capable of photographing, and computing factors such as ocean temperatures, sea levels, and concentrations of photosynthetic pigments, among others. In addition, specialized measuring devices were installed on a fishing ship to collect further information on yellowfin tuna feeding behavior, and barometric pressure readings during twenty fishing trips (randomly distributed) across the Mexican waters of the Gulf of Mexico. The results from the study show that barometric pressure is a more significant factor for predicting the distribution of yellowfin tuna than water temperature, a fact not fully addressed by documented research efforts in the field. Moreover, it was concluded that a multiple-degree polynomial model, probably a third-degree model, best represents the relationship between the identified independent variables and the dependent one (i.e., the expected number of yellowfin tuna caught per fishing trip).
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.
Modelación y simulación del tanque de contacto y los enfriadores de licor en el proceso de lixiviación carbonato-amoniacal con minerales lateríticos cubanos
Daniel Guzmán-Del río,Claudio García,Roger Misa-Llorca,Angel O. Columbié-Navarro
Minería y Geología , 2000,
Abstract: El presente trabajo muestra los resultados obtenidos por los autores en la investigación y análisis del modelo matemático del tanque de contacto y los enfriadores de licor en el proceso de lixiviación carbonato-amoniacal con minerales lateríticos cubanos, para su regulación automática. Se realiza un análisis de las principales variables que intervienen en el proceso ( en el tanque para el proceso de mezclado y en los enfriadores para el licor). Se propone un modelo matemático dinámico para el tanque de contacto y los enfriadores de licor con balances de masa y energía, expresando todas las dependencias dinámicas en ecuaciones diferenciales no lineales a parámetros concentrados. Se incluye además la simulación con datos reales de la planta.
Fractal Cracks Propagation in Aluminum  [PDF]
Francisco Casanova del Angel, Jaime Retama Velasco
Modeling and Numerical Simulation of Material Science (MNSMS) , 2013, DOI: 10.4236/mnsms.2013.33A004
Abstract: The theory of the fractal structure characterizing propagation of a crack through identification of its generator is presented. It’s generating fractal, the peculiarities of its construction and the way to measure its segments are defined, and a theorem on the inverse scale property of such and other of the axial symmetry property of the fractal generator are presented and demonstrated. The theory is applied on 6061-T6 aluminum samples, using SENB probes. Direction of crack propagation and its fractal dimension are calculated numerically. Results obtained from modeling the direction of crack propagation through mechanics of elastic linear fracture and the one proposed here, called geometrical fractal fracture, are compared, thus developing the mirror case.

Hierarchical Cores Applied to an Analysis of Use of Technologies Level among Higher Education Students in Mexico  [PDF]
Francisco Casanova-del-Angel
Open Journal of Statistics (OJS) , 2014, DOI: 10.4236/ojs.2014.410079
Abstract: Using the theory shown, Cores Optimal Criterion, three factors from which hierarchical aggregation of variables under study was built, as well as hierarchical cores showing the level of use of pocket computing technologies by students. The principal factors influencing the level of use of pocket computing technologies among higher education students are analyzed from a theoretical aggregation development based on hierarchical cores. The theoretical part includes the development of an algorithm used to obtain an interesting class or partition from a hierarchy. The experimental work carried out included design, preparation and application of a questionnaire to higher education students in Mexico. A pilot test was carried out to check timing and repetition of questions. Data was recorded, validated, and mathematically and statistically analyzed.
Corrosive Behavior and Physic-Chemical Characterization of Filtration Tanks  [PDF]
Francisco Casanova-del-Angel
Open Journal of Physical Chemistry (OJPC) , 2017, DOI: 10.4236/ojpc.2017.74008
Abstract: Most drinkable water supplied to the public in Mexico City comes from deep wells which extract water from the subsoil. Before being distributed, it is treated in steel filtration tanks. This water must be subject to evaluation through physic-chemical and bacteriological analyses in order to determine its quality. However, doubts always remain over the influence of the components of this water on the corrosive behavior of the filtration tanks. In light of this, this article studies the physic-chemical characterization values of water and presents the results. This has also enabled the analysis of the corrosion speed of filtration tanks components, boilers and water-cooled systems, where incrustations in pipes, obstructions and loss of heat transfer efficiency occur, rendering drinkable water bad tasting and, after some time, causing pitting corrosion although this type of corrosion only causes serious problems in the long term.
Transpose Return Relation Method for Designing Low Noise Oscillators
Jose Luis Jimenez-Martin;Vicente Gonzalez-Posadas;Angel Parra-Cerrada;álvaro Blanco-del-Campo;Daniel Segovia-Vargas
PIER , 2012, DOI: 10.2528/PIER12022305
Abstract: In this paper, a new linear method for optimizing compact low noise oscillators for RF/MW applications will be presented. The first part of this paper makes an overview of Leeson's model. It is pointed out, and it is demonstrates that the phase noise is always the same inside the oscillator loop. It is presented a general phase noise optimization method for reference plane oscillators. The new method uses Transpose Return Relations (RRT ) as true loop gain functions for obtaining the optimum values of the elements of the oscillator, whatever scheme it has. With this method, oscillator topologies that have been designed and optimized using negative resistance, negative conductance or reflection coefficient methods, until now, can be studied like a loop gain method. Subsequently, the main disadvantage of Leeson's model is overcome, and now it is not only valid for loop gain methods, but it is valid for any oscillator topology. The last section of this paper lists the steps to be performed to use this method for proper phase noise optimization during the linear design process and before the final non-linear optimization. The power of the proposed RRT method is shown with its use for optimizing a common oscillator, which is later simulated using Harmonic Balance (HB) and manufactured. Then, the comparison of the linear, HB and measurements of the phase noise are compared.
Proceso de lixiviación carbonato-amociacal: control multivariable a través del arreglo inverso de Nyquist para el mezclado de mineral y licor
Daniel Guzmán-del Río,Miguel A. Rodríguez-Borroto,Angel O. Columbié-Navarro,Roger Misa-Llorca
Minería y Geología , 2001,
Abstract: El trabajo muestra el resultado obtenido por los autores en el estudio y simulación del sistema del Tanque de Contacto de mineral reducido con licor carbonato-amoniacal existente en la Industria del Níquel. Partiendo de un estudio de su comportamiento en lazo abierto, se seleccionan los tipos de controladores para ser implementados. Se elige primeramente una técnica de control clásica basada en el Controlador PID Multilazo y se compara con una técnica de control de avanzada, representada por el Controlador Multivariable con Desacoplamiento a partir del Arreglo Inverso de Nyquist. Los resultados finales son mostrados en gráficos y curvas de respuestas, simulados con MATLAB, lo que permite determinar el mejor desempe o.
Modelo matemático del proceso de calcinación del carbonato básico de níquel (cbn) en el horno tubular rotatorio
Angel O. Columbié-Navarro,Juan Rodríguez-Gamboa,Daniel Guzmán-Del río,José Luis Sevila-Rodríguez
Minería y Geología , 2000,
Abstract: El presente trabajo recoge los resultados de los autores en lo relacionado con la modelación matemática del proceso de calcinación del carbonato básico de níquel en el horno tubular rotatorio. Se exponen las ecuaciones que conforman el modelo y la fundamentación científica sobre la cual fueron obtenidas. La modelación se basa principalmente en el planteamiento de las ecuaciones del balance material y energético en forma dinámica, que lleva a la obtención de un sistema de ecuaciones diferenciales en derivadas parciales, las cuales se complementan con otras ecuaciones algebraicas que establecen la relación entre los diferentes coeficientes y parámetros físicos.
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