Inhibition of Direct Prostaglandin F\u3csub\u3e2α\u3c/sub\u3e Effects on Pre-attachment Embryos Improves Reproductive Efficiency in Cattle

Prostaglandin F2α (PGF2α) has been shown to have detrimental effects on embryonic development, quality and hatching ability of embryos and pregnancy rates in cows. However, information about PGF2α receptor (FPr) mRNA and protein in the preattachment bovine embryo is absent in the literature. The first experiment was design to identify the period of time during in vitro embryo development that is most susceptible to PGF2α and to determine FPr mRNA and protein in bovine embryos. Prostaglandin F2α decreased development of embryos to compact morula, but had no effect on development to blastocyst. In addition, FPr mRNA and protein was confirmed by real time PCR and Western Blot analysis, respectively, suggesting that PGF2α is having a direct negative effect on in vitro development of bovine embryos by activating its receptor. Discovery of FPr in bovine embryos allowed for development of new therapeutic strategies aimed at improving reproduction in bovines. Therefore, in a second experiment, the effects of a selective FPr antagonist, AL-8810, on in vitro development of bovine embryos was evaluated. The antagonist did not have toxic effects on development of embryos. Subsequently, efficacy of AL-8810 to prevent PGF2α effects on pre-compacted embryos was investigated. Results showed that addition of AL-8810 to the culture medium inhibited PGF2α effects on development to morula stage. In a third experiment, embryonic development and gene expression of Na+/K+ ATPase α1 and zonula occludens-1 (ZO-1), two important genes participating in blastocyst formation and hatching, was examined after culture of in vivo-derived frozen/thawed bovine embryos with AL-8810, PGF, AL-8810+PGF, or Control. Thereafter, pregnancy rates of embryos recovered with medium containing AL-8810 was evaluated. Results indicated that AL-8810 inhibited negative effects of PGF2α on development of embryos; however, no differences in gene expression were observed. Furthermore, recovery of embryos with medium containing AL-8810 improved pregnancy rates following transfer to recipient cows. In conclusion, inhibition of PGF2α binding to its receptors on in vitro- and in vivo-derived bovine embryos increases embryonic development and pregnancy rates after transfer to recipient animals; respectively. These findings will likely increase efficiency of in vitro production of embryos and embryo transfer programs in cattle

Visualizando narrativas en economía

Contrariamente al resto de las ciencias sociales, los impactos de las narrativas en la economía y las finanzas carecen de un estudio extendido en la academia. Entendiendo a las narrativas como explicaciones de una determinada sucesión de eventos, son la base para la formación de expectativas y acciones por parte de los individuos. Existen dificultades para distinguir entre las narrativas asociadas al comportamiento económico y aquellas que generan cambios en el mismo, pero éstas no pueden ser consideradas como limitaciones al desarrollo del estudio de las narrativas (Shiller R.J., 2017). El objetivo de este trabajo es un intento a contribuir a este tipo de investigaciones (Scenna, M.R. 2018; en evaluación). A partir de noticias publicadas en la prensa británica entre 2005 y 2008, realizar las diferentes tipos de análisis y visualizar los resultados a través del tiempo tanto a nivel global como por cada medio gráfico.Sociedad Argentina de Informática e Investigación Operativ

Visualizando narrativas en economía

Contrariamente al resto de las ciencias sociales, los impactos de las narrativas en la economía y las finanzas carecen de un estudio extendido en la academia. Entendiendo a las narrativas como explicaciones de una determinada sucesión de eventos, son la base para la formación de expectativas y acciones por parte de los individuos. Existen dificultades para distinguir entre las narrativas asociadas al comportamiento económico y aquellas que generan cambios en el mismo, pero éstas no pueden ser consideradas como limitaciones al desarrollo del estudio de las narrativas (Shiller R.J., 2017). El objetivo de este trabajo es un intento a contribuir a este tipo de investigaciones (Scenna, M.R. 2018; en evaluación). A partir de noticias publicadas en la prensa británica entre 2005 y 2008, realizar las diferentes tipos de análisis y visualizar los resultados a través del tiempo tanto a nivel global como por cada medio gráfico.Sociedad Argentina de Informática e Investigación Operativ

Visualizando narrativas en economía

Contrariamente al resto de las ciencias sociales, los impactos de las narrativas en la economía y las finanzas carecen de un estudio extendido en la academia. Entendiendo a las narrativas como explicaciones de una determinada sucesión de eventos, son la base para la formación de expectativas y acciones por parte de los individuos. Existen dificultades para distinguir entre las narrativas asociadas al comportamiento económico y aquellas que generan cambios en el mismo, pero éstas no pueden ser consideradas como limitaciones al desarrollo del estudio de las narrativas (Shiller R.J., 2017). El objetivo de este trabajo es un intento a contribuir a este tipo de investigaciones (Scenna, M.R. 2018; en evaluación). A partir de noticias publicadas en la prensa británica entre 2005 y 2008, realizar las diferentes tipos de análisis y visualizar los resultados a través del tiempo tanto a nivel global como por cada medio gráfico.Sociedad Argentina de Informática e Investigación Operativ

A Strategy for the Economic Optimization of Combined Cycle Gas Turbine Power Plants by Taking Advantage of Useful Thermodynamic Relationships

Optimal combined cycle gas turbine power plants characterized by minimum specific annual cost values are here determined for wide ranges of market conditions as given by the relative weights of capital investment and operative costs, by means of a nonlinear mathematical programming model. On the other hand, as the technical optimization allows identifying trends in the system behavior and unveiling optimization opportunities, selected functional relationships are obtained as the thermodynamic optimal values of the decision variables are systematically linked to the ratio between the total heat transfer area and the net power production (here named as specific transfer area). A strategy for simplifying the resolution of the rigorous economic optimization problem of power plants is proposed based on the economic optima distinctive characteristics which describe the behavior of the decision variables of the power plant on its optima. Such approach results in a novel mathematical formulation shaped as a system of nonlinear equations and additional constraints that is able to easily provide accurate estimations of the optimal values of the power plant design and operative variables.Fil: Godoy, Ezequiel. UTN. FRRo. CAIMI; ArgentinaFil: Benz, Sonia Judith. UTN. FRRo. CAIMI; ArgentinaFil: Scenna, Nicolás José. UTN. FRRo. CAIMI; Argentina - CONICET. INGAR; ArgentinaPeer Reviewe

Non-Catalytic Thermal Reforming of JP-8 in a Distributed Reactor

This investigation focuses on developing a fundamental understanding of the thermochemical behavior of the application of the advanced combustion technique of Colorless Distributed Combustion to the thermal partial oxidation of a hydrocarbon fuel. Distributed Reaction Regime is achieved through internal entrainment and dilution to enlarge the “reaction zone” to encompass the entire reactor. The expanded reaction zone results in a uniform thermal field and product distribution. This in turn increases the local availability of water and carbon dioxide, which promotes steam and dry reforming reactions to a lesser extent, enhancing syngas yields. It was observed that the more distributed conditions (greater entrainment) yielded higher reformate quality. In the high temperature reactor, this resulted in higher hydrogen yields. In lower temperature reactor, the more distributed conditions shifted the hydrocarbon carbon distribution to favor ethylene and methane over acetylene. Middle distillate fuels are very challenging to reform. The high sulfur, aromatic, and carbon content inherent in these fuels will often deactivate conventional reforming catalysts. To compensate for the lack of catalyst, non-catalytic reformers employ high reactor temperatures, but this promotes soot formation and reduces reforming efficiency. Reforming under Distributed Reaction Regime avoids the issues associated with catalysts, while avoiding the issues associated with operating at higher reactor temperatures. The middle distillate fuel, Jet Propellant 8 (JP-8) is of particular interest to the military for small fuel cell applications and was determined to be a good representative for middle distillate fuels. This novel approach to reforming is undocumented in literature for a non-catalytic approach. This investigation studies the thermochemical behavior of a middle distillate fuel under reforming conditions. Chemical time and length scales are controlled through variations in injection temperature, oxidizer concentration, and steam addition. Two reactors were developed to study two different temperature ranges (700-800°C and 900-1100°C). These reactors will allow systematic means to enhance favorable hydrogen and carbon monoxide yields. Through the course of investigation it was observed that conditions that promoted a more distributed reactor were found to yield higher quality reformate. On multiple instances, the improvement to reforming efficiencies was greater than could be accounted for by varying the reactants alone. Reforming efficiency was demonstrated as high as 80%, rivaling that of catalytic reforming (85%)[1]. The Distributed Reaction Regime suppressed soot formation from occurring within reactor. No soot formation within the reactor was observed while operating within the Distributed Reaction Regime

Families of optimal thermodynamic solutions for combined cycle gas turbine (CCGT) power plants

Optimal designs of a CCGT power plant characterized by maximum second law efficiency values are determined for a wide range of power demands and different values of the available heat transfer area. These thermodynamic optimal solutions are found within a feasible operation region by means of a nonlinear mathematical programming (NLP) model, where decision variables (i.e. transfer areas, power production, mass flow rates, temperatures and pressures) can vary freely. Technical relationships among them are used to systematize optimal values of design and operative variables of a CCGT power plant into optimal solution sets, named here as optimal solution families. From an operative and design point of view, the families of optimal solutions let knowing in advance optimal values of the CCGT variables when facing changes of power demand or adjusting the design to an available heat transfer area.Fil: Godoy, Ezequiel. UTN. FRRo. CAIMI; ArgentinaFil: Scenna, Nicolás José. UTN. FRRo. CAIMI; Argentina - CONICET. INGAR; ArgentinaFil: Benz, Sonia Judith. UTN. FRRo. CAIMI; ArgentinaPeer Reviewe

A risk-based design of ammonia refrigeration systems in food manufacturing plants

This paper presents a risk-based design procedure of ammonia based refrigeration processes taking into account the allocation of the manufacturing plant and the surrounding environment vulnerability at early stages of process design. In addition, the proposed design framework allows the integration of a process simulator with vulnerability assessment packages. As a case study, the design of the refrigeration system for a surimi manufacturing plant is presented.Fil: Biscotti, Paola Silvina. Universidad Tecnológica Nacional. Regional Rosario. Centro de Aplicaciones Informáticas y Modelado en Ingeniería; ArgentinaFil: Reinheimer, Maria Agustina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Tecnológica Nacional. Regional Rosario. Centro de Aplicaciones Informáticas y Modelado en Ingeniería; ArgentinaFil: Scenna, Nicolas Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentina. Universidad Tecnológica Nacional. Regional Rosario. Centro de Aplicaciones Informáticas y Modelado en Ingeniería; Argentin

A rigorous, mixed-integer, nonlineal programming model (MINLP) for synthesis and optimal operation of cogeneration seawater desalination plants

This paper presents a rigorous mixed-integer nonlinear programming (MINLP) model for optimal synthesis and design of dual-purpose seawater desalination plants. The proposed superstructure considers more alternative configurations than the model recently proposed by Mussati et al. [1] and all process equipment is modelled in a rigorous way. The MINLP model introduces binary variables in order to select equipment for the cogeneration plant. The detailed model for the MSF desalter developed by Mussati et al. [2] was considered. The MSF mathematical model involves the real-physical constraints for the evaporation process. Nonlinear equations are used to model all plant equipment rigorously in terms of chemico-physical properties (enthalpies, entropies, vapor pressure) and design equations (efficiencies, NEA, BPE, heat transfer coefficients, momentum balances, among others). The proposed model is not only useful for synthesis, but also for analyzing different design alternatives. The model has been implemented in a general algebraic modelling system [4]. Several study cases were successfully solved by applying the MINLP model. A case study is presented in order to illustrate the model's capabilities.Fil: Mussati, Sergio Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Aguirre, Pio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; ArgentinaFil: Scenna, Nicolas Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo y Diseño. Universidad Tecnológica Nacional. Facultad Regional Santa Fe. Instituto de Desarrollo y Diseño; Argentin