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Dinámica espacio-temporal de oxígeno-temperatura en los lagos Zempoala y Tonatiahua

JUDITH GARCIA RODRIGUEZ Migdalia Díaz Vargas (2012)

Los estudios nictimerales son particularmente importantes en los trópicos para conocer las variaciones ecológicas en ciclos diurnos, y no sólo en estacionales, y lo son no sólo desde el punto de vista conceptual, sino para la aplicación de planes de manejo en diferentes ambientes. El objetivo fue analizar las variaciones del oxígeno disuelto, porcentaje de saturación y temperatura en la columna de agua durante ciclos nictimerales, en los lagos Zempoala y Tonatiahua ubicados en el Parque Nacional Lagunas de Zempoala. Los mayores valores oxígeno disuelto, se presentaron en Zempoala, y la temperatura fue análoga en ambos lagos de acuerdo a los valores promedio totales. La variación de los parámetros estuvo directamente influenciada por la estacionalidad, su morfometría y entorno. El lago Zempoala se consideró como meromictico con tendencias a monomíctico cálido y Tonatiahua como

monomíctico cálido / Héctor Quiroz Castelán, Oliva Mondragón Eslava, Isela Molina Astudillo, Judith García Rodríguez y Migdalia Díaz Vargas.

The nictimeral studies are particularly important in the tropics, to know the ecology variations in diurnal cycles and not only in seasonal cycles. And this is not only from the conceptual point of view, rather for the application of management plans in different environments. The objective was to analyze the variations of dissolved oxygen, percentage of saturation and temperature in the water column during nictimeral cycles, in the lakes of Zempoala and Tonatiahua located in the National Park Lagunas de Zempoala. The greater values of oxygen appeared in Zempoala, and the temperature was analogous in both lakes according to the total values average. Variation of the parameters was directly influenced by the seasonal changes, its morphometry and surroundings. Zempoala lake was considered itself as meromictic with tendencies to warm monomictic and Tonatiahua as warm monomictic.

Article

CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA INGENIERÍA Y TECNOLOGÍA DEL MEDIO AMBIENTE Temperatura Oxígeno disuelto Estacionalidad Ciclos nictimerales Variaciones ecológicas Variación estacional Lago Zempoala (Morelos) Lago Tonatiahua (Morelos) Temperature Dissolved oxygen Seasonal changes Nictimeral cycles Ecological variations Seasonal variation

Algunas propiedades químicas indicadoras de eventos de surgencias costeras y de la contracorriente subsuperficial en un área cercana a Punta Colonet, Baja California.

SOME CHEMICAL PROPERTIES INDICATING COASTAL UPWELLING EVENTS AND SUBSURFACE COUNTERCURRENT IN AN AREA NEAR PUNTA COLONET, BAJA CALIFORNIA

Guillermo Torres Moye (1986)

El análisis de los fosfatos y el oxígeno disuelto medidos en julio de 1980, en un área cercana a Punta Colonet, BC, sugiere la ocurrencia de eventos de surgencia costera. Los fosfatos preformados permitieron ubicar la contracorriente subsuperficial, la cual mostró tener una estructura compleja, y se presentó debajo de los 150m, hasta 600m de profundidad, y alcanzó distancias de hasta 100km fuera de la costa y con dirección principal de movimiento noroeste cerca del talud continental según la distribución de la utilización de oxígeno.

The analysis of phosphates and dissolved oxygen measured in July, 1980, in an area near Punta Colonet, BC, suggests the occurrence of coastal upwelling events. The preformed phosphates allowed to locate the subsurface countercurrent which proved to be of a complex structure, appearing from 150m to 600m deep, reaching distances up to 100km offshore, and with a main course of movement towards the northwest near the continental slope, according to the distribution of the apparent oxygen utilization.

Article

Fosfatos, Oxígeno disuelto, Punta Colonet, B.C., Eventos de surgencia costera, Phosphates, Dissolved oxygen, Coastal upwelling events CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA FÍSICA (VE R 5603 .04)

Influencia del drenaje de estanques de cultivo de camarón sobre las características físicas y químicas de las aguas marinas adyacentes

CARLOS HERNANDO LECHUGA DEVEZE Ibán Murillo Murillo FRANCISCO EDUARDO HERNANDEZ SANDOVAL Renato Arturo Mendoza Salgado (1997)

"De agosto 1993 a octubre 1996 se realizaron muestreos mensuales en tres estanques para cultivo de camarón y en el medio marino adyacente, con el objetivo de identificar el impacto ambiental de los estanques en el medio exterior. Se obtuvieron datos de temperatura, oxígeno disuelto, salinidad, sulfatos, nitritos, nitratos, ortofosfatos y fósforo orgánico. El muestreo se extendió durante tres fases del desarrollo y operación de los estanques: a) Fase inicia! (sin intercambio de agua y sin camarones en cultivo), identificada por altos valores de salinidad (80%0) y de sulfatos (6 g 1•1), y una gran variación de los nitritos dentro de los estanques; b) Fase intermedia (con un intercambio de agua del 30% y camarones alimentados con peletizados), caracterizada por un equilibrio entre el interior y el exterior de los estanques; y c) Fase final (con intercambio de agua del 30%, organismos alimentados con peletizados, fertilización de estanques y aereación mecánica), identificada por un aumento en la variación del oxígeno disuelto, nitratos y ortofosfatos dentro y fuera de los estanques, y por un aumento del fósforo orgánico en el interior de estos. En la segunda fase del cultivo se obtuvo un rendimiento de 450 kg ha•1 y en la fase final se elevó hasta 1500 kg ha•1• La materia orgánica introducida a los estanques durante la fase final (alimento peletizado, producción de microalgas y excretas del metabolismo del camarón) fue adecuadamente mineralizada, por lo que solamente se aportaron al exterior iones inorgánicos. Bajo estas condiciones de manejo se producen atractivos rendimientos y los estanques de cultivo no ocasionan un impacto ambiental negativo inmediato en las aguas adyacentes. "

"Monthly sampling was performed during August 1993 to October 1996, inside and outside three tidal ponds used far shrimp culture. Our aim was to identify if the culture conditions could influence the surrounding waters and induce some adverse impact. Temperature, dissolved oxygen, salinity, sulfate, nitrate, nitrite, inorganic and organic phospho­rous variables were measured. The sampling period comprised three stages of ponds development: a) lnitial stage (0% of water exchange, no shrimp culture) characterized by high salinity (80%0) and sulfate (6 g 1•1) values, and high nitrite variability; b) lntermediate stage (30% of water exchange, shrimps fed with pelleted food), where a balance between external and internal variables was reached. lt was obtained a yield of 450 kg ha-1. c) Final stage (introducing paddle­wheel aerators and fertilizing the ponds with superphosphate and urea), showing an increase in dissolved oxygen, nitrates and inorganic phosphorous variability, either inside and outside the ponds, and an increase in organic phos­phorous inside the ponds. During this final stage a yield of 1500 kg ha•1 was obtained. The organic matter input by the pelleted food, induced microalge growth and shrimp •metabolism during the final stage, was efficiently oxidized inside the ponds. In such a way only inorganic N and P were observed outside the ponds matching the internal variability. The management of these ponds at this final stage does not induce a negative environmental impact on surrounding wa􀀁 ters, and assures an attractive shrimp harvesting."

Article

Nitrógeno, fósforo, salinidad, sulfatos, temperatura, oxígeno disuelto, cultivo de camarón, estanques intermareales. Nitrogen, phosphorous, salinity, sulfate, temperature, dissolved oxygen, shrimp culture, tidal ponds BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA ANIMAL (ZOOLOGÍA) ZOOLOGÍA MARINA ZOOLOGÍA MARINA

Influence of the oxygen pressure on the physical properties of the pulsed-laser deposited Te doped SnO2 thin films

JOSE ALBERTO DUARTE MOLLER JOSE PASCUAL BARTOLO PEREZ (2010)

Tellurium doped tin oxide (Te:SnO2) thin films were prepared by pulsed-laser deposition (PLD) on glass substrates at different oxygen pressures, and the effects of oxygen pressure on the physical properties of as-grown and post-annealed Te:SnO2 films were investigated. The as-grown films deposited between 1.0 and 50 mTorr showed some evidence of diffraction peaks, with electrical resistivity of ∼8×101 Ωcm, but increasing the oxygen pressure up to 100 mTorr, three diffraction peaks (1 1 0), (1 0 1) and (2 1 1) were observed containing the SnO2 tetragonal structure, at 100 mTorr the electrical resistivity decreased abruptly at minimum value of 4×10−2 Ωcm, and increased reaching values of ∼4×10−1 Ωcm. The optical transmittance of the films increased with increasing oxygen pressure and high transmittance (∼87%) in VIS region by the films prepared at 100 mTorr and higher. The band gap of as-grown films was ∼3.5 eV corresponding at of the SnO2. After of post-annealed at 500° at atmospheric pressure for 30 min all films showed crystallization, and notable electrical resistivity changes were observed. The carrier density increased monotonically in the range of oxygen pressure between 1.0 and 100 mTorr, reaching values of∼2×1018 cm−3, then, it decreased abruptly in films grown at 125 mTorr. While the mobility of the freecarrier decreased in the range of oxygen pressure between 1.0 and 100 mTorr, reaching minimum value of ∼5.8cm2 V−1 s−1. The optical transmittance showed similar characteristic like the as-grown films. The figure of merit at 100 mTorr of as-grown films had value ∼1.2×10−5 Ω−1, and for post-annealed films at 100 mTorr the figure of merit was similar ∼1.7×10−6 Ω−1, indicating they were the better films.

Article

Oxygen CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA FÍSICA OTRAS ESPECIALIDADES FÍSICAS OTRAS

Synthesis of carbon nano-onions doped with nitrogen using spray pyrolisis

EDUARDO TOVAR MARTINEZ JOSE ADAN MORENO TORRES JORGE VALENTIN CABRERA SALAZAR MARISOL REYES REYES Luis Felipe Cházaro Ruiz ROMAN LOPEZ SANDOVAL (2018)

"In this work, we have synthesized carbon nano-onions (CNOs) doped with nitrogen and iron carbide core. These nanostructures were synthesized pyrolysing various alcohol-benzylamine reaction mixtures. These CNOs showed a certain degree of functionalization of their surfaces, depending of the solvent, as well as n-type doping due to the inclusion of N atoms in the graphene layers. Ratios of O atoms to C atoms as well as to N atoms of the pyrolyzed solution play an important role in the morphology of the CNOs and on the phase of the iron core. Differences in the morphology of the samples have an important effect on their electrical conductivity as well as in their electrochemical properties. Synthesized samples showing well-defined CNOs, the sintering between them is negligible, have a low conductivity and higher capacitance, while those samples showing the best conductivities and lower capacitances, the CNOs in samples are connected between them by turbostratic graphite ribbons, in similar way to the CNOs synthesized from carbon nanodiamond annealed in argon atmosphere."

Article

Electrochemical performance Raman-spectroscopy Oxygen Nanotubes Reduction Nanodiamond Nanoparticles Graphene Soot Microscopy BIOLOGÍA Y QUÍMICA QUÍMICA QUÍMICA

Modulación de la distribución vertical de oxígeno disuelto por remolinos de mesoescala en el Golfo de México

Modulation of the vertical distribution of dissolved oxygen by mesoscale eddies in the Gulf of Mexico

SIRIA RAQUEL MUÑOZ NAVARRO (2021)

La variabilidad estacional y espacial de las concentraciones de oxígeno disuelto dentro de remolinos de mesoescala, desde la región central y oeste del Golfo de México fue estudiada a partir de datos obtenidos con gliders. La modificación de la Zona de Mínimo Oxígeno del remolino de la Corriente del Lazo Poseidón fue monitoreada por un año, desde el desprendimiento de la Corriente del Lazo hasta su disipación en el oeste del golfo. El hundimiento de aguas elevadas en oxígeno disuelto evita la formación de regiones con bajas concentraciones en presencia de remolinos de la Corriente del Lazo. Además de la evolución de esta característica, durante de su monitoreo se observó la formación de un máximo somero (sub-superficial) de oxígeno disuelto debajo de la capa de mezcla de verano, su desaparición debido a la mezcla profunda en la temporada de los vientos Nortes y su formación de nuevo durante primavera-verano. Este máximo somero se observa en regiones oligotróficas y en los remolinos de mesoescala puede ser formado por dos maneras, con procesos termodinámicos y por productividad biológica. Para determinar el proceso presente se correlacionaron los porcentajes de saturación de oxígeno disuelto para determinar el estado del agua, y además las concentraciones de clorofila. Los resultados indican que los remolinos ciclónicos son más productivos que los remolinos anticiclónicos debido a un mayor porcentaje de saturación de oxígeno disuelto en la capa eufótica. En el Golfo de México, los procesos de layering, subducción y la presencia de los remolinos intratermoclinos de submesoescala pueden modificar un perfil típico de oxígeno disuelto dentro de remolinos anticiclónicos exportando aguas con concentraciones relativamente altas de oxígeno disuelto a profundidades de 100-400 m de profundidad. Estos procesos de variabilidad de pequeña escala son en gran medida desconocidos y estudios futuros tienen que orientarse en su caracterización espacial y temporal.

The seasonal and spatial variability of dissolved oxygen concentrations within mesoscale eddies from the central and western Gulf of Mexico was studied from glider data. The modification of the Oxygen Minimum Zone of the Poseidon Loop Current eddy was monitored for one year, from the detachment of the Loop Current to its dissipation in the western gulf. The sinking of high waters in dissolved oxygen prevents the formation of regions with low concentrations in the presence of eddies of the Loop Current. In addition to the evolution of this characteristic, during its monitoring, a shallow (sub-surface) maximum of dissolved oxygen was observed below the summer mixing layer, its disappearance due to deep mixing in the Northern winds season and its formation again during spring-summer. This shallow maximum is observed in oligotrophic regions and in mesoscale eddies can be formed in two ways, by thermodynamic processes and by biological productivity. To determine the present process, the dissolved oxygen saturation percentages were correlated to determine the state of the water, and also the chlorophyll concentrations. The results indicate that cyclonic eddies are more productive than anticyclonic eddies due to a higher percentage of dissolved oxygen saturation in the euphotic layer. In the Gulf of Mexico, the processes of layering, subduction, and the presence of submeso-scale intratermoclinal eddies can modify a typical dissolved oxygen profile within anticyclonic eddies by exporting waters with relatively high dissolved oxygen concentrations at depths of 100-400 m. These small-scale variability processes are largely unknown and future studies need to focus on their spatial and temporal characterization.

Master thesis

Golfo de México, Corriente del Lazo, remolinos de mesoescala, Remolinos de la Corriente del Lazo, oxígeno disuelto, Zona de Mínimo Oxígeno, Giro de Campeche, máximo sub-superficial, gliders Gulf of Mexico, Loop Current, mesoscale eddies, Loop Current Eddies, dissolved oxygen, Oxygen Minimum Zone, Campeche Gyre, sub-subsurface maximum, gliders CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA FÍSICA (VE R 5603 .04) OCEANOGRAFÍA FÍSICA (VE R 5603 .04)

Refinación microestructural de C-11000 para mejorar sus propiedades mecánicas

GERARDO RENDÓN GUTIÉRREZ (2018)

Este trabajo analizó el comportamiento de la microestructura de soleras de cobre con variación en componentes químicos que se presentan en la materia prima utilizada —que usualmente se denominan impurezas del metal—, en diferentes corridas de producción de lingotes de cobre aleación C-11000. Se determinaron los valores que ayudan a conformar mejor la estructura del cobre y se evaluaron resultados después de los procesos de extrusión en caliente y estirado en frío; se analizó el tamaño de grano generado en cada pieza y se determinaron los rangos de manejo de los componentes que ayudan a refinar el grano, permiten que sea homogéneo y que, al ser fabricado como solera de cobre, cumpla con las propiedades físicas y mecánicas que el producto requiere. Las propiedades mecánicas relevantes en las soleras de cobre para uso eléctrico se orientan a tener dobleces libres de rugosidad y fracturas potenciales, así como asegurar una superficie lisa y sin deformaciones. Se analizó el impacto de dos componentes químicos (fierro y oxígeno) que, bajo contenidos controlados, ayudan a conformar mejor la estructura granular de las soleras.

The behavior of bus-bar grain size is analyzed related to different chemical components, commonly called impurities, that were added in the melting process to produce copper billets of alloy C-11000, those components were used in controlled amounts in the mix and formed the metal structure, the reaction in the metal’s structure after the extrusion and drawing process, the microstructure improve substantially and the appearance in the bending process obtain a better and smooth surface of the product processed and meet with the properties required by norms for electrical use, free of rugosity and potential fractures. The use of controlled levels of iron and oxygen in the melting process were tested to evaluate the impact of bus bar’s grain size.

Estudio promovido y asesorado por el área de estudios de Posgrado del CIATEQ, A.C., en convenio con la empresa Industrias Unidas S. A. de C. V.

Article

Cobre Microestructura Refinación de grano Contenidos de oxígeno Nivel de fierro Procesos de doblez Extrusión y estirado en frío Copper Microstructure Grain refining Oxygen content Iron level Bending process Extrusion and cold drawing INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA METALÚRGICA COBRE COBRE

Estimation of hydrogen production in genetically modified E. coli fermentations using an artificial neural network

LUIS MANUEL ROSALES COLUNGA RAUL GONZALEZ GARCIA ANTONIO DE LEON RODRIGUEZ (2010)

"Biological hydrogen production is an active research area due to the importance of this gas as an energy carrier and the advantages of using biological systems to produce it. A cheap and practical on-line hydrogen determination is desired in those processes. In this study, an artificial neural network (ANN) was developed to estimate the hydrogen production in fermentative processes. A back propagation neural network (BPNN) of one hidden layer with 12 nodes was selected. The BPNN training was done using the conjugated gradient algorithm and on-line measurements of dissolved CO2, pH and oxidation-reduction potential during the fermentations of cheese whey by Escherichia coli ΔhycA ΔlacI (WDHL) strain with or without pH control. The correlation coefficient between the hydrogen production determined by gas chromatography and the hydrogen production estimated by the BPNN was 0.955. Results showed that the BPNN successfully estimated the hydrogen production using only on-line parameters in genetically modified E. coli fermentations either with or without pH control. This approach could be used for other hydrogen production systems."

Article

Back propagation neural network Dissolved CO2 Hydrogen Redox potential pH Cheese whey BIOLOGÍA Y QUÍMICA

Flow and temperature effect on thin films of yttria-stabilized zirconia by sputtering

DANIEL RICARDO ORTIZ PALACIOS ERIKA JUDITH HERRERA JIMENEZ JOSE ALBERTO DUARTE MOLLER HILDA ESPERANZA ESPARZA PONCE (2009)

The oxides ZrO2-Y2O3 and ZrO2 films have been applied in science and technology of thermal

barrier coatings, electrodes in smart windows, oxygen-permeable electrolytes for gas sensors

and fuel cells1-2, however; nowadays there is more interest because their high mechanical

properties and high-energy band gap changes on submicron scales.

Conference proceedings

Oxygen-permeable BIOLOGÍA Y QUÍMICA QUÍMICA OTRAS ESPECIALIDADES QUÍMICAS OTRAS

Heart metabolic disturbances in cardiovascular diseases.

KARLA GUADALUPE CARVAJAL AGUILERA RAFAEL MORENO SANCHEZ (2003)

Myocardial function depends on adenosine triphosphate (ATP) supplied by oxidation of several substrates. In the adult heart, this energy is obtained primarily from fatty acid oxidation through oxidative phosphorylation. However, the energy source may change depending on several factors such as substrate availability, energy demands, oxygen supply, and metabolic condition of the individual. Surprisingly, the role of energy metabolism in development of cardiac diseases has not been extensively studied. For instance, alterations in glucose oxidation and transport developed in diabetic heart may compromise myocardial performance under conditions in which ATP provided by glycolysis is relevant, such as in ischemia and reperfusion. In some cardiac diseases such as ischemic cardiomyopathy, heart failure, hypertrophy, and dilated cardiomyopathy, ATP generation is diminished by derangement of fatty acid delivery to mitochondria and by alteration of certain key enzymes of energy metabolism. Shortage of some co-factors such as L-carnitine and creatine also leads to energy depletion. Creatine kinase system and other mitochondrial enzymes are also affected. Initial attempts to modulate cardiac energy metabolism by use of drugs or supplements as a therapeutic approach to heart disease are described

Article

MEDICINA Y CIENCIAS DE LA SALUD Adenosina Trifosfato metabolismo Cardiotónicos Enfermedades Cardiovasculares - Metabolismo Miocardio - Metabolismo Miocardio - Patología Oxigeno - Metabolismo Adenosine triphosphate - Metabolism Cardiotonic agents Cardiovascular diseases - Metabolism Myocardium - Metabolism Myocardium - Pathology Oxygen - Metabolism Metabolismo energético Metabolismo del corazón Glicolisis Fosforilación oxidativa Creatina quinasa L- carnitina Energy metabolism Heart metabolism Glycolysis Oxidative phosphorylation Creatine kinase L-carnitine