An optimization approach to study the phase changing behavior of multi-component mixtures

The appropriate design, construction, and operation of carbon capture and storage (CCS) and enhanced oil recovery (EOR) processes require a deep understanding of the resulting phases behavior in hydrocarbons-CO_2 multi-component mixtures under reservoir conditions. To model this behavior a nonlinear system consists of the equation of states and some mixing rules (for each component) needed to be solved simultaneously. The mixing usually requires to model the binary interaction between the components of the mixture. This work employs optimization techniques to enhance the predictions of such model by optimizing the binary interaction parameters. The results show that the optimized parameters, although obtained mathematically, are in physical ranges and can reproduce successfully the experimental observations, specially for the multi-component hydrocarbons systems containing Carbon dioxide at reservoir temperatures and pressuresComment: To be published in Cadernos do IME - S\'erie Matem\'atica da UER

Mediciones del consumo energético en un prototipo de vivienda construida con bloques de hormigón celular curado en autoclave

Se presentan las mediciones de consumo de energía, efectuadas en un prototipo de vivienda social emplazado en el INTI, que se ha instrumentado para registrar valores de temperatura y humedad relativa en el interior y las condiciones meteorológicas a que se encuentra expuesto. Tales mediciones contemplan consumos diarios tanto de energía eléctrica como de gas natural, como así también las correspondientes a cada artefacto existente en su interior. Asimismo se realiza una comparación con resultados obtenidos en los trabajos precedentes.Measurements of power consumption carried out in a social housing prototype located at INTI are presented. This prototype is instrumented to record internal temperature and relative humidity values and weather conditions under which it is exposed. Such measurements take into account electrical energy and natural gas daily consumptions as well as those belonging to each home device. Also, a comparison with results obtained in preceding works is realized. This presentation is the third stage of the work “INTI Social Interest Housing”.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Mediciones del consumo energético en un prototipo de vivienda construida con bloques de hormigón celular curado en autoclave

Se presentan las mediciones de consumo de energía, efectuadas en un prototipo de vivienda social emplazado en el INTI, que se ha instrumentado para registrar valores de temperatura y humedad relativa en el interior y las condiciones meteorológicas a que se encuentra expuesto. Tales mediciones contemplan consumos diarios tanto de energía eléctrica como de gas natural, como así también las correspondientes a cada artefacto existente en su interior. Asimismo se realiza una comparación con resultados obtenidos en los trabajos precedentes.Measurements of power consumption carried out in a social housing prototype located at INTI are presented. This prototype is instrumented to record internal temperature and relative humidity values and weather conditions under which it is exposed. Such measurements take into account electrical energy and natural gas daily consumptions as well as those belonging to each home device. Also, a comparison with results obtained in preceding works is realized. This presentation is the third stage of the work “INTI Social Interest Housing”.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Direct and indirect effects of a pH gradient bring insights into the mechanisms driving prokaryotic community structures

Background: pH is frequently reported as the main driver for prokaryotic community structure in soils. However, pH changes are also linked to "spillover effects" on other chemical parameters (e.g., availability of Al, Fe, Mn, Zn, and Cu) and plant growth, but these indirect effects on the microbial communities are rarely investigated. Usually, pH also co-varies with some confounding factors, such as land use, soil management (e.g., tillage and chemical inputs), plant cover, and/or edapho-climatic conditions. So, a more comprehensive analysis of the direct and indirect effects of pH brings a better understanding of the mechanisms driving prokaryotic (archaeal and bacterial) community structures. Results: We evaluated an agricultural soil pH gradient (from 4 to 6, the typical range for tropical farms), in a liming gradient with confounding factors minimized, investigating relationships between prokaryotic communities (16S rRNA) and physical-chemical parameters (indirect effects). Correlations, hierarchical modeling of species communities (HMSC), and random forest (RF) modeling indicated that both direct and indirect effects of the pH gradient affected the prokaryotic communities. Some OTUs were more affected by the pH changes (e.g., some Actinobacteria), while others were more affected by the indirect pH effects (e.g., some Proteobacteria). HMSC detected a phylogenetic signal related to the effects. Both HMSC and RF indicated that the main indirect effect was the pH changes on the availability of some elements (e.g., Al, Fe, and Cu), and secondarily, effects on plant growth and nutrient cycling also affected the OTUs. Additionally, we found that some of the OTUs that responded to pH also correlated with CO2, CH4, and N2O greenhouse gas fluxes. Conclusions: Our results indicate that there are two distinct pH-related mechanisms driving prokaryotic community structures, the direct effect and "spillover effects" of pH (indirect effects). Moreover, the indirect effects are highly relevant for some OTUs and consequently for the community structure; therefore, it is a mechanism that should be further investigated in microbial ecology.Peer reviewe

Direct and indirect effects of a pH gradient bring insights into the mechanisms driving prokaryotic community structures

Background: pH is frequently reported as the main driver for prokaryotic community structure in soils. However, pH changes are also linked to "spillover effects" on other chemical parameters (e.g., availability of Al, Fe, Mn, Zn, and Cu) and plant growth, but these indirect effects on the microbial communities are rarely investigated. Usually, pH also co-varies with some confounding factors, such as land use, soil management (e.g., tillage and chemical inputs), plant cover, and/or edapho-climatic conditions. So, a more comprehensive analysis of the direct and indirect effects of pH brings a better understanding of the mechanisms driving prokaryotic (archaeal and bacterial) community structures. Results: We evaluated an agricultural soil pH gradient (from 4 to 6, the typical range for tropical farms), in a liming gradient with confounding factors minimized, investigating relationships between prokaryotic communities (16S rRNA) and physical-chemical parameters (indirect effects). Correlations, hierarchical modeling of species communities (HMSC), and random forest (RF) modeling indicated that both direct and indirect effects of the pH gradient affected the prokaryotic communities. Some OTUs were more affected by the pH changes (e.g., some Actinobacteria), while others were more affected by the indirect pH effects (e.g., some Proteobacteria). HMSC detected a phylogenetic signal related to the effects. Both HMSC and RF indicated that the main indirect effect was the pH changes on the availability of some elements (e.g., Al, Fe, and Cu), and secondarily, effects on plant growth and nutrient cycling also affected the OTUs. Additionally, we found that some of the OTUs that responded to pH also correlated with CO2, CH4, and N2O greenhouse gas fluxes. Conclusions: Our results indicate that there are two distinct pH-related mechanisms driving prokaryotic community structures, the direct effect and "spillover effects" of pH (indirect effects). Moreover, the indirect effects are highly relevant for some OTUs and consequently for the community structure; therefore, it is a mechanism that should be further investigated in microbial ecology.Peer reviewe

Mediciones higrotérmicas efectuadas en una vivienda construida con bloques de hormigón celular curado en autoclave

Se presentan las mediciones efectuadas en un prototipo de vivienda social emplazada en el INTI, asimismo se realiza una evaluación higrotérmica y energética utilizando el programa de simulación ENERGY PLUS. Esta presentación corresponde a la segunda etapa del trabajo original “Vivienda de Interés Social INTI” en el cual se evalúan diferentes sistemas constructivos mediante ensayos y cálculos teóricos con el objeto de construir un prototipo que cumpla con los niveles de confort y características constructivas que establecen las Normas IRAM. El año 2003 se expuso dicha etapa en ASADES Formosa bajo el nombre “Evaluación integral del comportamiento higrotérmico y energético de variantes para la construcción de viviendas en tiempos cortos”. Los registros recogidos de la vivienda construida manifiestan un buen comportamiento térmico del sistema. La amplitud de las curvas de humedad y temperatura interna son notablemente menores que la externa a lo largo del año.This work presents measurements made in a social-interest house located in INTI. An energetic evaluation was also run with Energy Plus Software. This presentation belongs to a second part of the original work called “INTI´s social-interest house” where three types of constructions are evaluated by theoretical and experimental tests in order to build a model that checks the comfort levels that are specified in IRAM Standards. The first part of the project, “Integral evaluation of variants in higrothermal and energetic behavior for buildings in short periods” was exposed in 2003 in ASADES. The registries of the house built demonstrate an excellent thermal behavior of the system; the humidity curves and temperatures do not follow the outdoor measurements. Otherwise, they keep constant throughout the year with gradual oscillations.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Mediciones higrotérmicas efectuadas en una vivienda construida con bloques de hormigón celular curado en autoclave

Se presentan las mediciones efectuadas en un prototipo de vivienda social emplazada en el INTI, asimismo se realiza una evaluación higrotérmica y energética utilizando el programa de simulación ENERGY PLUS. Esta presentación corresponde a la segunda etapa del trabajo original “Vivienda de Interés Social INTI” en el cual se evalúan diferentes sistemas constructivos mediante ensayos y cálculos teóricos con el objeto de construir un prototipo que cumpla con los niveles de confort y características constructivas que establecen las Normas IRAM. El año 2003 se expuso dicha etapa en ASADES Formosa bajo el nombre “Evaluación integral del comportamiento higrotérmico y energético de variantes para la construcción de viviendas en tiempos cortos”. Los registros recogidos de la vivienda construida manifiestan un buen comportamiento térmico del sistema. La amplitud de las curvas de humedad y temperatura interna son notablemente menores que la externa a lo largo del año.This work presents measurements made in a social-interest house located in INTI. An energetic evaluation was also run with Energy Plus Software. This presentation belongs to a second part of the original work called “INTI´s social-interest house” where three types of constructions are evaluated by theoretical and experimental tests in order to build a model that checks the comfort levels that are specified in IRAM Standards. The first part of the project, “Integral evaluation of variants in higrothermal and energetic behavior for buildings in short periods” was exposed in 2003 in ASADES. The registries of the house built demonstrate an excellent thermal behavior of the system; the humidity curves and temperatures do not follow the outdoor measurements. Otherwise, they keep constant throughout the year with gradual oscillations.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Mediciones higrotérmicas efectuadas en una vivienda construida con bloques de hormigón celular curado en autoclave

Se presentan las mediciones efectuadas en un prototipo de vivienda social emplazada en el INTI, asimismo se realiza una evaluación higrotérmica y energética utilizando el programa de simulación ENERGY PLUS. Esta presentación corresponde a la segunda etapa del trabajo original “Vivienda de Interés Social INTI” en el cual se evalúan diferentes sistemas constructivos mediante ensayos y cálculos teóricos con el objeto de construir un prototipo que cumpla con los niveles de confort y características constructivas que establecen las Normas IRAM. El año 2003 se expuso dicha etapa en ASADES Formosa bajo el nombre “Evaluación integral del comportamiento higrotérmico y energético de variantes para la construcción de viviendas en tiempos cortos”. Los registros recogidos de la vivienda construida manifiestan un buen comportamiento térmico del sistema. La amplitud de las curvas de humedad y temperatura interna son notablemente menores que la externa a lo largo del año.This work presents measurements made in a social-interest house located in INTI. An energetic evaluation was also run with Energy Plus Software. This presentation belongs to a second part of the original work called “INTI´s social-interest house” where three types of constructions are evaluated by theoretical and experimental tests in order to build a model that checks the comfort levels that are specified in IRAM Standards. The first part of the project, “Integral evaluation of variants in higrothermal and energetic behavior for buildings in short periods” was exposed in 2003 in ASADES. The registries of the house built demonstrate an excellent thermal behavior of the system; the humidity curves and temperatures do not follow the outdoor measurements. Otherwise, they keep constant throughout the year with gradual oscillations.Asociación Argentina de Energías Renovables y Medio Ambiente (ASADES

Generalized Holographic Dark Energy Model

In this paper, the model of holographic Chaplygin gas has been extended to two general cases: first is the case of modified variable Chaplygin gas and secondly of the viscous generalized Chaplygin gas. The dynamics of the model are expressed by the use of scalar fields and the scalar potentials.Comment: 12 pages, to appear in Eur. Phys. J.