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Search Results: 1 - 10 of 239624 matches for " Alberto D. Hernández-Suzan "
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“Anti-Michael” and Michael Additions in the Reactions of 2-Arylmethyliden-1,3-Indandiones with 2-Aminothiophenol  [PDF]
Jessica J. Sánchez García, Alberto D. Hernández-Suzan, Elena Martínez-Klimova, Marcos Flores-Alamo, Teresa Ramírez Apan, Elena I. Klimova
International Journal of Organic Chemistry (IJOC) , 2017, DOI: 10.4236/ijoc.2017.71006
Abstract: A novel 2-indano[2,3b]-2-ferrocenyl- and 2-indano[2,3b]-2-(p-methoxy-phenyl)[1,5]benzo-2,5-dihydrothiazepine 5a,b (addition Michael/cyclization) (~30.32%), indano[2,3b]-2-ferrocenyl- and 2-(p-methoxyphenyl)[1,4] benzothiazine 4a,b (addition “anti-Michael”/cyclization) (~45.43%), respectively, were obtained by the condensation of 2-ferrocenyl-and 2-(p-methoxy-phenyl)methyliden-1,3-indandiones 1a,b with o-aminothiophenol 2 in the presence of AcOH and HCl. A new “anti-Michael” addition reaction of 1,4-bis-heteronucleophile 2 into 2-arylmethyliden-1,3-indandiones was reported. As a result of this reaction the product 1a,b was obtained. The structures of the resultant compounds were elucidated by IR, 1H and 13C NMR spectroscopy, mass spectrometry, elemental and X-ray diffraction analysis. The in vitro antitumor activity of the obtained products was researched using the following human cancer cell lines: glioblastoma (CNS U-251), prostatic adenocarcinoma (PC-3), chronic myelogenous leukemia (K562), colorectal adenocarcinoma (HCT-15), mammary adenocarcinoma (MCF-7), and small cell lung cancer (SKLU) and the sulforhodamine B (SRB) method. Among these new compounds some thiazine and thiazepine derivatives showed compelling in vitro antitumor effects on cell lines K-562, HCT-15, SKLU-1 and MCF-7.
Growth Kinetics of Vegetative and Reproductive Organs of Guava (Psidium guajava L.) in Iguala Guerrero, Mexico  [PDF]
Agustín Damián Nava, Víctor A. González Hernández, Manuel Nava Jaimes, Elías Hernández Castro, Dolores Vargas álvarez, Gemima Díaz Villase?or, Francisco Palemón Alberto, Blas Cruz Lagunas
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.514157
Abstract: In the Mexican tropics the guava trees can grow and produce in any season, so they can be har-vested out of the period of high competition marketing (Summer). It?studied the growth kinetics of leaves and fruits of guava trees at the dry tropical conditions of the State of Guerrero, in guava trees of four years old and was evaluated a non-destructive method for measuring leaf area from November to May. 100 sheets of 10 randomly selected trees were cut. It was found that leaf length X the width X 0.72581647 (conversion factor) gave an estimated leaf area which?was significantly correlated with that obtained by the integrator of leaf area. Both in length and width the leaf growth kinetics were sigmoid with three growth stages: In Stage I (15 days) leaves grew 21.2% and 21.5%; in Stage II (26 days) grew 73.6% and 68%; and in Stage III (30 days). They Increased 5.2% and 10.5% in the primary and secondary sprouts. The fruit growth in its equatorial and polar diameters corresponded to a double sigmoid kinetics. In Stage I (61 days) it reached 1.9 and 2.3 cm; in Stage II (62 - 102 days) it reached 3.09 and 3.62 cm; and in Stage III (103 to 126 days) it reached 4.63 and 5.13 cm, as well the physiological maturity of fruit.
Mejoramiento de Procesos clave a través del análisis del Valor A?adido en Empresas de Base Tecnológica de Producciones por Proyecto del Sector Hidráulico en Cuba
Hernández Oro,Reina Maylín; Medina León,Alberto A.; Hernández Pérez,Gilberto D.;
Visi?3n de futuro , 2012,
Abstract: in this paper, we present the main results of research designed to improve key business processes, using a procedure designed for this purpose, and which includes among its main stages, the analysis of value added by activity, adapting to technology based companies’ productions by one of the water sector project in cuba. the procedure consistently combines different techniques such as multi-criteria decision analysis for selection of the key processes and analysis of value added by activity to identify key processes to improve and identify opportunities for improvement. the main results are able to identify, classify and relate the processes taking place in the organization, and represent them in a process map, and then determine the key processes for improvement, based on the analysis of value added at each process of each of the activities in it. derived from the results obtained are proposed and implemented a set of organizational improvements had a positive economic impact for the company under study, allowing a positive conclusion on the feasibility of implementation, flexibility and robustness of the procedure developed in technology-based companies single project productions of the water sector in cuba to support their business management.
IMPROVEMENT OF KEY PROCESSES THROUGH THE ANALYSIS OF VALUE ADDED IN TECHNOLOGY- BASED COMPANIES A SINGLE PROJECT PRODUCTIONS OF THE WATER SECTOR IN CUBA
Reina Maylín, Hernández Oro,Alberto A., Medina León,Gilberto D., Hernández Pérez
Visi?3n de futuro , 2012,
Abstract: In this paper, we present the main results of research designed to improve key business processes, using a procedure designed for this purpose, and which includes among its main stages, the analysis of value added by activity, adapting to technology based companies’ productions by one of the water sector project in Cuba. The procedure consistently combines different techniques such as multi-criteria decision analysis for selection of the key processes and analysis of value added by activity to identify key processes to improve and identify opportunities for improvement. The main results are able to identify, classify and relate the processes taking place in the organization, and represent them in a process map, and then determine the key processes for improvement, based on the analysis of value added at each process of each of the activities in it. Derived from the results obtained are proposed and implemented a set of organizational improvements had a positive economic impact for the company under study, allowing a positive conclusion on the feasibility of implementation, flexibility and robustness of the procedure developed in technology-based companies single project productions of the water sector in Cuba to support their business management.
MEJORAMIENTO DE PROCESOS CLAVE A TRAVéS DEL ANáLISIS DEL VALOR A ADIDO EN EMPRESAS DE BASE TECNOLóGICA DE PRODUCCIONES POR PROYECTO DEL SECTOR HIDRáULICO EN CUBA
Reina Maylín, Hernández Oro,Alberto A., Medina León,Gilberto D., Hernández Pérez
Visi?3n de futuro , 2012,
Abstract: En este artículo se muestran los principales resultados de una investigación orientada al mejoramiento de procesos empresariales clave, aplicando un procedimiento dise ado a tal efecto y donde se incluye entre sus etapas principales, el análisis del valor a adido por actividad, adaptándolo a empresas de base tecnológica de producciones por proyecto único (o singular) del sector hidráulico cubano. En el procedimiento se combinan de forma coherente diferentes técnicas, tales como el Análisis Decisional Multicriterio para la selección de los procesos clave y el Análisis del Valor A adido por actividad para determinar los procesos clave a mejorar e identificar las oportunidades de mejora. Como principales resultados se logró identificar, clasificar y relacionar los procesos que se desarrollan en la organización y representarlos en un mapa de procesos, para luego determinar los procesos clave para la mejora, sobre la base del análisis del valor a adido a cada proceso de cada una de las actividades que lo integran. Derivado de los resultados obtenidos, se propuso e implementó un grupo de mejoras organizativas que tuvieron un impacto económico positivo para la empresa objeto de estudio, lo que permitió concluir favorablemente sobre la factibilidad de aplicación, flexibilidad y robustez del procedimiento desarrollado en las empresas de base tecnológica de producciones por proyecto único del sector hidráulico en Cuba para apoyar su gestión empresarial.
The risk of upper gastrointestinal complications associated with nonsteroidal anti-inflammatory drugs, glucocorticoids, acetaminophen, and combinations of these agents
Luis Alberto García Rodríguez, Sonia Hernández-Díaz
Arthritis Research & Therapy , 2000, DOI: 10.1186/ar146
Abstract: Most anti-inflammatory drugs have been associated with gastrointestinal side effects. Gastrointestinal mucosa damage can range from endoscopic lesions with no clinical manifestations to serious upper gastrointestinal complications (UGIC) that, in some instances, may be fatal. Because of their relatively low incidence, severe gastrointestinal events can only be effectively evaluated in large, post-marketing, observational studies. This document presents epidemiological evidence of the magnitude of the risk of upper gastrointestinal tract bleeding or perforation among users of anti-inflammatory drugs: oral steroids, aspirin, nonaspirin nonsteroidal anti-inflammatory drugs (NA-NSAIDs), and acetaminophen (paracetamol in Europe). Two methods will be used to examine the interaction resulting from multiple use of anti-inflammatory drugs on the risk of UGIC: firstly, we shall review epidemiological findings published by other authors [1,2,3,4,5,6,7,8,9,10]; and, secondly, we shall summarize results published by our group [11,12,13]. These cited papers provide a more detailed description of the methodology.Our data was based on a nested case–control study carried out in the UK General Practice Research Database (GPRD) for the period 1993–1998. The study population consisted of 958,397 persons aged 40–79 years who had been enrolled for at least 2 years, and who were free of cancer, esophageal varices, Mallory–Weiss disease, liver disease, coagulopathies and alcohol-related disorders at the start date. All members of the source population were followed-up until they met a case definition criterion or an exclusion criterion, or until they died. We identified patients with codes for UGIC and manually reviewed the demographic data and clinical information in the computerized patient profiles. We excluded subjects with any of the risk factors already mentioned in the 2 months after the date of case detection, and excluded subjects in whom the sources of the bleeding and perforatio
Simulación del vaciado continuo de perfiles de aceros al carbono de baja aleación
Díaz-Hernández,Yusdel; Fiol-Zulueta,Alberto; Arzola-Ruiz,José;
Ingenier?-a Mec??nica , 2013,
Abstract: in this paper an algorithm to simulate the process of continuous casting based on a physical -mathematical model using finite element methods was presented. the most outstanding characteristic of the model was the inclusion of complex processes of heat interchange, metal phase changes, distribution of temperatures in the mould, chemical composition of the metal, flow of water in the primary and secondary cooling system and the casting speed. moreover, the algorithm permitted to predict the behaviour of the process variables in the continuous casting of steel according to its profile and type.
Modelación y simulación de disipadores de calor para procesadores de computadora en COMSOL Multiphysics Modeling and simulation of heat sinks for computer processors in COMSOL Multiphysics
Sulin Garro Acón,Luis Alberto Díaz Espinoza,Jian Liang,Fabio Martínez Hernández
Tecnología en Marcha , 2012,
Abstract: En este estudio se analizó la transferencia de calor en tres disipadores de calor utilizados para enfriar los procesadores de computadoras de escritorio. El objetivo de estos disipadores es evitar el sobrecalentamiento de la unidad de procesamiento y la consecuente reducción de la vida útil del computador. Los disipadores de calor se modelaron usando COMSOL Multiphysics con las dimensiones reales de los dispositivos y la generación de calor se modeló con una fuente puntual. Luego se modificaron los dise os de los disipadores para lograr una temperatura más baja en la zona más caliente del procesador. El resultado fue una reducción en la temperatura en el rango de 5-78 grados Kelvin, al redise arse el disipador de calor con variaciones feasibles como la reducción del grosor de las placas de intercambio de calor y el aumento de su número. Esto demuestra la posibilidad de desarrollar dise os optimizados para disipadores de calor que no requieran más materiales sino una mejor ingeniería. El trabajo se inició como parte del curso CM-4101 Modelización y Simulación. In this study, the heat transfer of three desktop- computer heat sinks was analyzed. The objective of using these heat sinks is to avoid overheating of the computer’s processing unit and in turn reduce the corresponding loss in the unit’s service time. The heat sinks were modeled using COMSOL Multiphysics with the actual dimensions of the devices, and heat generation was modeled with a point source. In the next step, the heat sink designs were modified to achieve a lower temperature in the higher temperature location on the heat sink. The results were temperature reductions in the range of 5-78 degrees Kelvin, by making feasible variations in design such as reducing the thickness of the heat exchanger fins and increasing their number. This paper demonstrates that there is room to develop improved designs that do not require more materials but rather a better engineering design. Initial work was done in the course CM-4101 Modeling and Simulation.
Análisis e implementación de algoritmos evolutivos para la optimización de simulaciones en ingeniería civil. (draft)
José Alberto García Gutiérrez,Alejandro Mateo Hernández Díaz
Computer Science , 2014,
Abstract: This paper studies the applicability of evolutionary algorithms, particularly, the evolution strategies family in order to estimate a degradation parameter in the shear design of reinforced concrete members. This problem represents a great computational task and is highly relevant in the framework of the structural engineering that for the first time is solved using genetic algorithms. You are viewing a draft, the authors appreciate corrections, comments and suggestions to this work.
UNA REVISIóN HISTóRICA: DESDE EL DIBUJO EN INGENIERíA HACIA LA INGENIERíA DEL DISE?O
ROJAS-SOLA,JOSé IGNACIO; FERNáNDEZ-SORA,ALBERTO; SERRANO-TIERZ,ANA; HERNáNDEZ-DíAZ,DAVID;
DYNA , 2011,
Abstract: this article presents a historical research on the evolution over time of progress experienced by the geometry, and particularly the technical drawing as engineering drawing, making the review by steps including the ancient world, the middle age, the renaissance, the modern age, the twentieth century and the current drawing in engineering, to finish exposing some future trends. also, it is presented the most important historical landmarks such as the emergence of the first examples of standard views and perspective, and the apparition of systems of representation of the descriptive geometry, particularly the dihedral system, which were the development of engineering graphics until now to be pillars in engineering design.
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