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Search Results: 1 - 10 of 672507 matches for " R. O. Borges Maga?a "
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Alta infestación por varroa (Varroasis) y su respuesta al utilizar el panal trampa - Hight infestation by Varroa (Varroasis) and their answer to use honeycomb trap
Y. J. Mendoza Falcón,R. O. Borges Magaa,Nelda M. Carbonell Castro
REDVET , 2012,
Abstract: RESUMENEl ácaro Varroa destructor parasita a todas las castas de abejas, constituyendo la principal plaga que afecta a la apicultura mundial, provocando altas mortalidades.ABSTRACTThe parasitic mite Varroa destructor parasites all castes of bees, constituting the major pest affecting apiculture worldwide, causing high mortality.
Necrosis en postlarvas de camarón - Necrosis′s in post larva of shrimp
R.O. Borges Magaa,Y. J. Mendoza Falcón,Nelda M Carbonell Castro
REDVET , 2012,
Abstract: ResumenLa necrosis, en larvas de cultivo, ha sido responsable de grandes pérdidas económicas para los camaronicultores de varias partes del mundo, al afectar principalmente a la especie de Litopenaeus vannamei.AbstractThe necrosis, in cultivation larvas, has been responsible for big economic losses for shrimp cultivators in several parts of the world, when affecting mainly to the cultivations of Litopenaeus vannamei.
Análisis de modos de falla, efectos y criticidad (AMFEC) para la planeación del mantenimiento empleando criterios de riesgo y confiabilidad
José R. Aguilar-Otero,Rocío Torres-Arcique,Diana Magaa-Jiménez
Tecnología, Ciencia, Educación , 2010,
Abstract: Tradicionalmente en la plantas químicas existen planes de mantenimiento para los equipos, basados en recomendaciones del fabricante, determinados en periodos fijos, basados en políticas internas de la planta o bien simplemente aplicando un mantenimiento correctivo, es decir, reparar hasta que falla. Sin embargo, el objetivo de toda gerencia del mantenimiento es siempre el de mantener sus equipos o activos en la máxima disponibilidad y confiabilidad, a fin de poder garantizar una continua producción, sin embargo, Garantiza esto que los esfuerzos del mantenimiento son enfocados adecuadamente? La planeación del mantenimiento viene cambiando en nuestros días a fin de incorporar criterios de riesgo y confiabilidad, de manera que además de asegurar un impacto de las acciones de mantenimiento en el rendimiento de los activos, se tenga un impacto en la seguridad al disminuir, evaluar y controlar el riesgo, administrando el riesgo. Motivo de esto, se ha empleado un análisis de riesgo, aplicando la metodología de análisis de modos de falla, efectos y criticidad (FMECA o AMFEC) con objeto de identificar los modos de falla que representan un mayor riesgo, para posteriormente seleccionar la mejor tarea de mantenimiento, ya sea preventiva, predictiva, correctiva o en su caso acciones adicionales o complementarias. Se define un modo de falla, como la forma en la que un activo pierde su habilidad para desempe ar su función, entrando en el estado de falla, falla funcional. El presente trabajo ilustra el proceso de análisis y aplicación de la metodología de FMECA o AMFEC en el proceso de gestión del mantenimiento, específicamente en la etapa de la planeación, etapa considerada como crítica. Ilustrando la aplicación de la metodología para una planta endulzadora de gas. El FMECA o AMFEC consiste en las siguientes etapas: Definición de la intención de dise o, análisis funcional, identificación de modos de falla, efectos de la falla, criticidad o jerarquización del riesgo y recomendaciones. Con la aplicación del FMECA AMFEC se identificaron los modos de falla que representan un mayor riesgo para la instalación, considerando los riesgos a la producción, instalación y al personal. Los modos de falla de mayor riesgo, son enviados a un proceso de selección de tareas de mantenimiento detallado, mientras que los modos de falla de medio y bajo riesgo, son tratados con un proceso genérico. Esto permite identificar las áreas donde el mantenimiento tendrá una mejor oportunidad para impactar la seguridad y confiabilidad de la instalación. Esto permite también, optimizar los recursos ya
Isotopic Variations of Oxygen (δ18O) in Benthic Foraminifera under Antiestuarine Conditions in the Colorado River Delta  [PDF]
Miguel A. Santa Rosa-del Río, Ismael Yarbuh, Rigoberto Guardado-France, Ronald M. Spelz, Raúl Herrera-Gutiérrez, Karla Mejia-Pi?a, Miguel Agustín Tellez-Duarte, Luis Antonio Cupul-Magaa
Open Journal of Geology (OJG) , 2018, DOI: 10.4236/ojg.2018.82007
Abstract: Benthic foraminifera are excellent environmental indicators; CaCO3 test records the isotopic concentration of their surroundings and can be used to analyze environmental changes that occur during a certain time period. Stable isotopes, particularly those of oxygen (δ18O), are useful for interpreting ancient environments, given that they are used as “proxy” environmental variables (temperature and salinity). In this study, we provide ranges of isotopic variation in benthic foraminifera communities from the Colorado River delta. Four sampling campaigns were conducted in one year (2009-2010) in the adjacent subtidal zone of Baja California. Four transects with a total of sixteen sample station were drawn perpendicular to the coastline. Here, we recorded the following in situ: sand-type, salinity, and temperature. In the laboratory, 300 individuals per sample were separated, and sub-samples were taken for isotopic analysis. Data was processed using the software’s R 2.12.2, PAST 1.81 and Arc Map 9.3. Forty species were identified in the dead assemblages (Thanatocoenosis), whereas thirteen species were found in the living assemblages (Biocoenosis). The most abundant species in both communities belong to the genera Ammonia and Cribroelphidium. In the living assemblages, isotopic variation 2.15% to 5.94% within a temperature interval of 11°C, indicated antiestuarine conditions. In the dead assemblages, isotopic composition 3.04 to 0.74 served as a sign of estuarine conditions prior to damming.
Dise o y construcción de un globo meteorológico cautivo instrumentado Design and construction of an instrumented meteorological tethersonde
Wilfrido Gutiérrez L.,Manuel García E.,Victor O. Magaa R.,Jorge A. Escalante G.
Ingeniería y Ciencia , 2007,
Abstract: Las observaciones de capa límite planetaria son clave para la realización del pronóstico numérico del tiempo. Los sistemas para perfilar la atmósfera tienen en general un alto precio, lo que los hace con frecuencia inaccesibles. Por ello, la necesidad de contar con instrumentos de medición a bajo costo que permitan obtener datos confiables ha llevado al dise o y construcción de un globo meteorológico cautivo instrumentado, comparable a los diversos sistemas existentes en el mercado internacional tales como radiosondeo, perfiladores de viento, SODARS y globos cautivos, entre otros. Al abatir el costo, se abre la posibilidad de realizar un mayor número de mediciones de calidad, útiles en estudios de procesos atmosféricos que determinan el tiempo meteorológico, pero sobre todo para mejorar la condición inicial de los modelos de pronóstico del tiempo. En este artículo se describe el dise o de un globo meteorológico cautivo de bajo costo con el cual se pueden mantener mediciones de capa límite de manera continua, útiles en estudios de procesos atmosféricos y en el pronóstico numérico del tiempo. La viabilidad del instrumento quedó demostrada en campa as de medición realizadas a bordo de un buque oceanográfico. Observations of the planetary boundary layer are essential for in numerical weather prediction. However, such observations are usually expensive, which makes them inaccessible for a majority of projects. Therefore, the need of less expensive instruments for boundary layer measurements has led to the design and construction of an instrumented meteorological captive balloon comparable with various existing systems such as radiosondes, wind pro lers, SODARS, or commercial tethersondes, among others. Lower cost instruments open the possibility of obtaining more quality data, useful for atmospheric processes studies and in numerical weather prediction activities. This paper describes the design of a low cost tethersonde useful in maintaining the continuous monitoring of boundary layer for processes studies and weather prediction. The viability of the instrument has been shown in meteorological eld campaigns on board of an oceanographic vessel.
Characterization of Lignin before and after Exposure to the Gastrointestinal Tract of Ruminants  [PDF]
E. O. S. Saliba, D. Pilo-Veloso, N. M. Rodriguez, E. A. Capanema, J. S. Saliba, A. L. C. C. Borges, L. C. Gon?alves, I. Borges, D. G. Jayme, R. R. Silva
American Journal of Analytical Chemistry (AJAC) , 2016, DOI: 10.4236/ajac.2016.711067
Abstract: The aim of this study was to investigate the structural composition of lignin (LIPE®) extracted from Eucalyptus grandis, before and after exposure to the gastrointestinal tract of ruminants. For this study lignin was isolated, purified and characterized using 1H and 13C Nuclear Magnetic Resonance Spectroscopy, nitrobenzene oxidation, functional groups analysis and gas chromatography with mass spectroscopy. To have a better understanding of lignin morphology and of its ultra structure, electron microscopy in wood cell wall was utilized. The lignin fecal samples showed similar 1H NMR spectrums and nitrobenzene oxidation products compared with LIPE®. The result of the microanalysis of LIPE® was similar to data shown in the literature. The ultra structure of lignin was similar to that of Bamboo (hard wood). The lignin isolated from feces of sheep was identical to the original LIPE®, which means that this product can be used as an external marker in protein digestibility in sheep.
Temporal and spatial behavior of temperature and precipitation during the canícula (midsummer drought) under El Ni?o conditions in central México
PERALTA-HERNáNDEZ, A. R;BARBA-MARTíNEZ, L. R;MAGAA-RUEDA, V. O;MATTHIAS, A. D;LUNA-RUíZ, J. J;
Atmósfera , 2008,
Abstract: relatively few studies have been performed about the onset, duration, and intensity of the canícula (midsummer drought) within central méxico in response to el ni?o/southern oscillation (enso) events. the objective of our research is to assess the impact of the el ni?o (en) phase of enso upon air temperature (t), precipitation (pp), and drought index (di = pp/t) during the canícula period. daily air temperature and precipitation data from weather stations throughout central méxico are averaged for eight consecutive 10 (or 11)-day periods during the summers of 1960 through 1998. the data are grouped into seven climate regions according to specific precipitation criteria. statistical comparisons between en and neutral (n) years for the seven regions are made with pooled average t, pp and di values from the summer. results indicate that the en phase significantly increases air temperatures within the wetter climate regions. the el ni?o phase also increases summer precipitation within five of the regions, though not significantly. the added summer rainfall during el ni?o phase does not reduce drought intensity with the exception of brief intervals within the wetter regions. roughly, during en and n years the canicula begins on july 11 and ends on august 31.
Distribución y abundancia de tanatocenosis de foraminíferos bentónicos submareales en el delta del río Colorado
Santa Rosa-del Río, Miguel ángel;ávila Serrano, Guillermo Eliezer;Téllez-Duarte, Miguel Agustín;Gonzalez-Yajimovich, Oscar;Cupul Magaa, Luis Antonio;
Boletín de la Sociedad Geológica Mexicana , 2011,
Abstract: benthonic foraminifera are important indicators of environmental conditions in coastal and marine areas since they are very sensitive to changes in their surroundings, resulting in presence and abundance of species of the thanatocoenosis communities. the objective of this work is to compare the spatial and temporal changes in the composition and structure of the benthonic-foraminifera thanatocoenosis communities of the upper gulf of california. samples were collected seasonally (summer, fall and winter of 2009, and spring of 2010) in the area between campo don abel and the southern end of isla montague. four transects of the subtidal area were run perpendicular to the baja california coastline, and a total of 56 sediment samples were taken. to differentiate the biocoenosis from thanatocoenosis, the samples were stained with rose bengal. silt and clay were eliminated by wet sieving and the 63 to 180 μm fractions retained for picking. from each sample, 300 individuals were separated, identified and their relative abundance computed to determine the dominant species. cluster analysis in q & r modes was performed on the data and the shannon-weaver diversity index calculated; dominance was obtained using simpson’s index, and a distribution map was constructed. the most abundant genera were: ammonia, cribroelphidium and rosalina; these represent preferably marine conditions, which show change in the upper gulf of california. also present were four genera of agglutinated foraminifera: ammoscalaria, reophax, anomaloides and nouria, but their distributions were centered at the southernmost stations of the study area, at the limits of the ancient estuary north of san felipe.
Influence of Organic and Mineral Soil Fertilization on Essential Oil of Spilanthes oleracea cv. Jambuarana
Luciana da S. Borges,Maria A.R. Vieira,Marcia O.M. Marques,Fabio Vianello
American Journal of Plant Physiology , 2012,
Abstract: In the present study, the composition of essential oil of leaves and inflorescences of jambu (Spilanthes oleracea . Jambuarana), under organic manuring and mineral fertilization, was studied. Jambu plants show important chemical properties and their production has been addressed for the extraction of the essential oils for cosmetics industries, due to their pharmacological properties. The experimental area of treatments contained urea as mineral fertilizer (120 g m2), applied twice and organic fertilizer (8 kg m2), applied at the planting. Jambu leaves and flowers were harvested twice: the first at 90 days after seedling transplantation and at the opening of the flower buds. Branches were cut at 7 cm from the soil, thus new branches can bud for the accomplishment of the second crop which happened 40 days after the re-budding. The essential oil was analyzed by gas chromatography coupled with mass-spectrometry. According to our results the most representative compounds were trans-caryophyllene, germacrene-D, 1-dodecene, spathulenol and spilanthol (a compound presenting anesthetic properties) occurring in inflorescences. Fertilization procedure does not affect the content and the quality of the essential oil in Jambu plants.
Prevalencia de nematodos gastroentéricos de becerros en sistemas de doble propósito del municipio de Escárcega, Campeche, México
Encalada-Mena, Lisandro A.;Corbala-Bermejo, J. Alfredo;Vargas-Magaa, J. José;García-Ramírez, M. Jesús;Uicab-Brito, Luís;Río-Rodríguez, José del;
Agrociencia , 2009,
Abstract: in tropical climates, nematodoses cause major economic losses and are of vital importance in dual purpose production systems because of the prevailing management conditions. this study determined the prevalence and intensity of infection by gastrointestinal nematodes (nge) in nursing calves and the rate of infecting nge larvae (l3) in pastures during three climatic seasons (dry, february to march; rainy, june to september; cold fronts ("nortes", october to january). the study was conducted from march 2006 to february 2007 on four dual purpose ranches with similar management, in escárcega, campeche, méxico. two age groups were formed with 509 bos indicus x bos taurus calves: i (birth to four months) and ii (four to seven months). monthly, coproparasitoscopic examinations (mcmaster) were conducted to determine number of eggs g-1 feces (hpg) and coprocultures by group. the ranch pastures were sampled (w method), and the sedimentation technique for l3 was performed. the analysis of variance showed the effect of age on prevalence; group i and ii averages were 62.31 % and 80.15 % (p<0.01). low (61.40 %) infection intensity was found to be different (p<0.01) from medium and high (23.90 % and 14.69 %) intensities. differences (p<0.01) in number of l3 were found among the seasons: dry, 21.25; rainy, 156.87; cold fronts (nortes), 117.81. the correlation between average precipitation and larva count in grass was 0.61. it is concluded that prevalence was not different among seasons of the year (p=0.105), but it was different between calf ages (p<0.01). during the rainy and cold front seasons, l3 counts on grass increased considerably, relative to the dry season. identified as predominant was the genus cooperia spp, followed by haemonchus spp and oesophagostomum sp. this information would help to plan de-worming calendars and pasture management in dual purpose systems.
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