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Search Results: 1 - 10 of 1981 matches for " Erika Espericueta "
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Effect of Aging in the Structure of Silica Xerogels with Incorporation of Extract’s Leaves  [PDF]
José R. Martínez, Erika Espericueta, Gerardo Ortega-Zarzosa
New Journal of Glass and Ceramics (NJGC) , 2011, DOI: 10.4236/njgc.2011.11002
Abstract: The spectral fluorescence characteristics of extracts leaves embedded in silica xerogel matrix promoted by aged time was studied. We obtain a higher PSII stability for extract of leaves embedded in xerogel matrix, with concentration of 8 g / 20 ml and water to TEOS molar ratio of 11, which remain bioactive over a very long period of time, whereas for a water to TEOS molar ratio of 5 a blue-shift fluorescence is observed indicating the PSII denaturizing and formation of fluorescing aggregates associated with the activation of carotenoids radicals.
Thermo-Stability of Natural Products Based on Chlorophyll Species Embedded in Silica Xerogel  [PDF]
José Martínez-Mendoza, Erika Espericueta-González, Diana Espericueta González, Gerardo Ortega-Zarzosa, Azdrubal Lobo Guerrero
American Journal of Analytical Chemistry (AJAC) , 2016, DOI: 10.4236/ajac.2016.74034
Abstract: This work studied the thermostability and the biostability of chlorophyll species obtained from an extract of spinach leaves embedded in a silica xerogel matrix. The analysis was done by monitoring the photosystem II (PSII) using fluorescence spectroscopy. Samples were prepared using the sol gel method with a molar ratio of ethanol/H2O/TEOS of 4:11.6:1. Then, silica xerogel matrix was loaded with an extract of spinach leaves, obtained in dark conditions. The measurement of the fluorescence spectra was done at selected temperatures to the corresponding non-physiological regimen. Results indicate that the PSII band position remains unchanged when heat treatment temperature increases up 200°C. For temperatures above 100?C, the fluorescence intensity diminishes linearly when the temperature increases. The photosystem II embedded in silica xerogel matrix is decomposed at temperatures above 200°C.
Structural Comportment of Extract of Bougainvillea xbuttiana Flower Incorporated in Silica Xerogel Matrix  [PDF]
José Martínez-Mendoza, Erika Espericueta-González, Diana Espericueta-González, Gerardo Ortega-Zarzosa, Azdrubal Lobo Guerrero
American Journal of Plant Sciences (AJPS) , 2016, DOI: 10.4236/ajps.2016.76078
Abstract: Measurement of the fluorescence comportment of Bougainvillea xbuttiana flowers embedded in silica xerogels matrix prepared with two different water to tetraethyl-orthosilicate [Si(OC2H5)4] ratio molar of 11 and 5, without heat-treatment, we report the grade of biostability of compound. The structural comportment for the PSI and PSII present in Bougainvillea flower is similar to the structural comportment for these photosystems present in leaves when they are incorporated on inorganic matrix such as silica xerogels. The contribution of the natural pigment of this kind of flower such as betalains which consist of betaxanthins and betacyanins, determines their colors contributed in the range of wavelength from about 550 nm to 660 nm.
Eliminación de bacterias patógenas en lodos residuales durante el secado solar
COTA-ESPERICUETA, Alma Delia;PONCE-CORRAL, Carlos;
Revista internacional de contaminación ambiental , 2008,
Abstract: this paper describes the performance of a solar dryer capable of bacterial pathogen removal from the physicochemical sludge of the main wastewater treatment plant for ciudad juárez, méxico. the solar setup was proposed as an alternative solution, technically feasible, for reducing the volume of the 135 tons of sludge produced per day in this plant. the experimental-greenhouse prototype has a 4.5 m2 collection area, a 1 m3-drying bed, and automatic systems for ventilation, extraction, and data acquisition. the automatic operation was controlled by temperature and humidity differences between internal and external conditions. global solar radiation, ph and water content of the sludge were monitored. the overall effectiveness of the solar dryer was determined by assessing thermal and microbiological performance. water content in sludge during the process was used as an indicator of thermal effectiveness. the microbiological elimination was quantified at different residence times considering two contamination indicators: faecal coliforms and salmonella spp. quantification of the pathogenic microorganisms was carried out by the multiple-tube fermentation technique presented in the mexican regulation nom-004-semarnat-2002. the thermal results related to the water content showed an exponential decay that achieved up to a 99 % reduction. regarding microbiological removal effectiveness, there was a strong dependence between the number of bacteria present and the water content in the sludge. as a consequence, with the removal of 92 % of water, it was verified that the elimination of faecal coliforms fell from 3.8x106 to 1.6 mpn per gram of dried sludge; and for salmonella spp. the reduction was from 1.5x1013 to 1.9x103 mpn per gram of dried sludge.
ELIMINACIóN DE BACTERIAS PATóGENAS EN LODOS RESIDUALES DURANTE EL SECADO SOLAR
Alma Delia COTA-ESPERICUETA,Carlos PONCE-CORRAL
Revista internacional de contaminación ambiental , 2008,
Abstract: La presente investigación describe el desempe o de un secador solar con respecto a la eliminación de bacterias patógenas contenidas en lodos fisicoquímicos provenientes de la principal Planta de Tratamiento de Aguas Residuales de Ciudad Juárez. El dispositivo solar fue propuesto como una alternativa técnica factible para la reducción de volumen de las 135 ton de lodos generadas por día en esta planta. El prototipo experimental tipo invernadero estuvo constituido por un área de captación de 4.5 m2 y un lecho de secado de 1 m3, además de los sistemas de ventilación, extracción y adquisición de datos. El funcionamiento automático del dispositivo estuvo regulado por las diferencias entre las condiciones internas y externas de las variables de temperatura y humedad. Además, se midieron la radiación solar, el pH y la humedad del lodo. La efectividad del secador fue determinada en términos térmicos y microbiológicos. La pérdida de agua en el lodo durante el tratamiento fue el indicativo de la efectividad térmica. La depuración microbiológica fue cuantificada a diferentes tiempos de residencia, mediante los indicadores de contaminación: coliformes fecales y Salmonella spp. La cuantificación de ambas bacterias se realizó a través de la técnica microbiológica de tubos de fermentación múltiple expuesta en la Norma Oficial Mexicana NOM-004-SEMARNAT-2002. Los resultados térmicos asociados al contenido de agua en el lodo mostraron un decaimiento exponencial hasta lograr el 99 % de reducción de la misma. En lo referente a la efectividad microbiológica, existió dependencia del contenido de las bacterias indicadoras con la cantidad de agua presente en lodo. Para la remoción del 92 % de agua, se verificó la eliminación de coliformes fecales desde 3.8x106 hasta 1.6 NMP por gramo de lodo seco y para Salmonella spp. dicha reducción fue desde 1.5x1013 hasta 1.9x103 NMP por gramo de lodo seco.
ELIMINACIóN DE BACTERIAS PATóGENAS EN LODOS RESIDUALES DURANTE EL SECADO SOLAR
Alma Delia COTA-ESPERICUETA,Carlos PONCE-CORRAL
Revista internacional de contaminación ambiental , 2008,
Abstract: La presente investigación describe el desempe o de un secador solar con respecto a la eliminación de bacterias patógenas contenidas en lodos fisicoquímicos provenientes de la principal Planta de Tratamiento de Aguas Residuales de Ciudad Juárez. El dispositivo solar fue propuesto como una alternativa técnica factible para la reducción de volumen de las 135 ton de lodos generadas por día en esta planta. El prototipo experimental tipo invernadero estuvo constituido por un área de captación de 4.5 m2 y un lecho de secado de 1 m3, además de los sistemas de ventilación, extracción y adquisición de datos. El funcionamiento automático del dispositivo estuvo regulado por las diferencias entre las condiciones internas y externas de las variables de temperatura y humedad. Además, se midieron la radiación solar, el pH y la humedad del lodo. La efectividad del secador fue determinada en términos térmicos y microbiológicos. La pérdida de agua en el lodo durante el tratamiento fue el indicativo de la efectividad térmica. La depuración microbiológica fue cuantificada a diferentes tiempos de residencia, mediante los indicadores de contaminación: coliformes fecales y Salmonella spp. La cuantificación de ambas bacterias se realizó a través de la técnica microbiológica de tubos de fermentación múltiple expuesta en la Norma Oficial Mexicana NOM-004-SEMARNAT-2002. Los resultados térmicos asociados al contenido de agua en el lodo mostraron un decaimiento exponencial hasta lograr el 99 % de reducción de la misma. En lo referente a la efectividad microbiológica, existió dependencia del contenido de las bacterias indicadoras con la cantidad de agua presente en lodo. Para la remoción del 92 % de agua, se verificó la eliminación de coliformes fecales desde 3.8x106 hasta 1.6 NMP por gramo de lodo seco y para Salmonella spp. dicha reducción fue desde 1.5x1013 hasta 1.9x103 NMP por gramo de lodo seco.
Alma Llanera: un adefesio convertido en himno popular
Perera,Erika;
Revista Venezolana de Economía y Ciencias Sociales , 2009,
Abstract: at the beginning of the twentieth century, juan vicente gómez adopted as policy the promoting of a national culture regarded as ?criollo? and identified with the values of the lowland plains which border the orinoco and apure rivers (los llanos). one of the intellectuals who most contributed to forging this ideology during the gómez period was pedro elias gutiérrez, soldier, compositor and director of the caracas martial band. his audience ranged from those who went the theater to the wider public attending the performances in the plaza bolivar every week from thursday to sunday. it was he who most popularized alma llanera, which had originally been a soap opera theme (?zarzuela?) and was converted into a national icon. during the course of the fourty years during which he conducted the martial band in the central square of caracas, this song became that most identified with venezuela abroad.
Use of Business Models within Model Driven Architecture
Erika Asnina
Scientific Journal of Riga Technical University. Computer Sciences , 2009, DOI: 10.2478/v10143-009-0010-1
Abstract: Model Driven Architecture is a framework dedicated for development of large and complex computer systems. It states and implements the principle of architectural separation of concerns. This means that a system can be modeled from three different but related to each other viewpoints. The viewpoint discussed in this paper is a Computation Independent one. MDA specification states that a model that shows a system from this viewpoint is a business model. Taking into account transformations foreseen by MDA, it should be useful for automation of software development processes. This paper discusses an essence of the Computation Independent Model (CIM) and the place of business models in the computation independent modeling. This paper considers four types of business models, namely, SBVR, BPMN, use cases and Topological Functioning Model (TFM). Business persons use SBVR to define business vocabularies and business rules of the existing and planned domains, BPMN to define business processes of both existing and planned domains, and use cases to define business requirements to the planned domain. The TFM is used to define functionality of both existing and planned domains. This paper discusses their capabilities to be used as complete CIMs with formally defined conformity between planned and existing domains.
Environmental Communication Instruments for Environmental Policy Integration
Erika Lagzdina
Scientific Journal of Riga Technical University. Environmental and Climate Technologies , 2010, DOI: 10.2478/v10145-010-0035-2
Abstract: Two public policy concepts - modernization of governance and environmental policy integration - serve as the basis for this work. The author links them up with environmental communication (EC) as an integration instrument approach, and tests application at the local level in Latvia. Totally 30 case studies were analysed and survey methods used to interview over 70 people. The article verifies driving forces affecting the internal and external integration of environmental policy, explicates EC instrumentality for integration by assessing policy instruments and stakeholders. The final conclusions affirm that, in order to integrate environmental management into municipal development, it is necessary to establish a complementary set of policy instruments, what might be enabled by wise use of all EC components in their interactivity. The complementarity of EC instruments and stakeholder group efforts forms synergy and enhances better environmental policy integration.
Contextualising Intersex: Ethical discourses on Intersex in Sweden and the US
Erika Alm
Graduate Journal of Social Science , 2010,
Abstract: As of the beginning of the 1990s the medical management of intersex has been up for debate, and the U.S. has been the epicentre of debate. Scholars like Iain Morland and Anne Fausto-Sterling have identified three key actors in the U.S. context: clinicians, patient oriented support groups and intersex advocacy organizations, and feminist scholars with a critical perspective on the medical discourse surrounding sex and gender identity (Fausto-Sterling 2000; Morland 2004). There has been fairly little discussion about intersex rights in Sweden until the last couple of years. The budding Swedish discussions are all framed by international discourses, especially the U.S. discussions among clinicians on the pros and cons of the traditional treatment model, and the discussions between intersex people, intersex advocates, clinicians and politicians on intersex rights. However, while the U.S. discourses on intersex have been greatly affected by the participation of feminist scholars such influences have been scarce in Sweden. This article explores differences and similarities between the Swedish and the U.S. context, arguing that the relative lack of feminist scholarly attention to intersex has had consequences for the Swedish discussion.
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