254 research outputs found

    Diseño del sistema de distribución del afluente en unidades de tratamiento de aguas residuales domésticas

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    The efficient treatment of domestic wastewater is associated with good operational practices in wastewater treatment plants (WWTP) and the proper design of each treatment unit, which ensures the correct hydraulic performance of each WWTP. For this reason, the objective of this article was to study the design of the multiple influent distribution systems of a high-rate primary sedimentary, a UASB (Upflow Anaerobic Sludge Blanket) reactor, and an up-flow anaerobic filter (FAFA) in the WWTPs of the municipalities of San Carlos and San Roque, and in the township of Santiago, respectively, located in Antioquia-Colombia. For this purpose, the methodology proposed by Hudson in 1981 was used to evaluate the performance of the current design and, subsequently, a pre-dimensioning was carried out to distribute the flow uniformly, to have velocities within the ranges recommended by the literature, and to obtain the total head loss generated by the distribution manifold in each treatment unit evaluated. It was found that the existing design is not efficient and that the new pre-dimensioning ensures homogeneous flow distribution and provides velocities that contribute positively to the treatment process. The study concludes that the smaller the number of orifices and the larger the pipe diameter, the more uniform the flow distribution, and that the total head loss depends on both the velocity head and the head loss coefficient. The diameter of the orifice was the predominant parameter to control the inlet velocity of the treatment units.El tratamiento eficiente de las aguas residuales domésticas está asociado a las buenas prácticas operacionales en las plantas de tratamiento de agua residual (PTAR) y al diseño adecuado de cada unidad de tratamiento, con lo cual se asegura el correcto funcionamiento hidráulico de cada PTAR. Por tal motivo, el objetivo de este artículo fue estudiar el diseño de los múltiples sistemas de distribución del afluente de un sedimentador primario de alta tasa, un reactor UASB (Upflow Anaerobic Sludge Blanket) y un filtro anaerobio de flujo ascendente (FAFA) en las PTAR de los municipios de San Carlos y San Roque, y en el corregimiento de Santiago, respectivamente, ubicados en Antioquia-Colombia. Para ello, se utilizó la metodología propuesta por Hudson en 1981 para evaluar el funcionamiento del diseño actual y, posteriormente, se realizó un predimensionamiento que permitiera distribuir el caudal uniformemente, tener velocidades dentro de los rangos recomendados por la literatura y obtener la pérdida de carga total generada por el múltiple de distribución en cada unidad de tratamiento evaluada. Se evidenció que el diseño existente no es eficiente y que el nuevo predimensionamiento asegura la distribución homogénea del caudal y proporciona velocidades que contribuyen positivamente al proceso de tratamiento. El estudio concluye que a menor número de orificios y mayor diámetro de tubería se presenta una distribución uniforme del caudal, además que la pérdida de carga total depende, tanto de la cabeza de velocidad, como del coeficiente de pérdida de carga. El diámetro del orificio fue el parámetro predominante para controlar la velocidad de entrada a las unidades de tratamiento

    Study of Sound Perception Evaluation in Refrigeration Gases

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    In the past, sound design was focused on the minimization of the emitted sound, understanding that the lower the sound, the better. Nowadays, this concept is outdated; in addition to the sound pressure level, many more aspects of the sound are considered to fulfil the subjective satisfaction of clients. Thus, a new concept called sound quality has emerged to reach more facets of the sound. In refrigeration systems, the recommendations of European Union are aimed at reducing greenhouse emissions by means of the replacement of the hydrochlorofluorocarbons gases with other less pollutant gases. The refrigeration systems are designed to be used with a specific refrigeration gas, and the noise emitted by these systems is certificated using this refrigeration gas. However, the regularizations have changed, and new refrigerant gases should be used. Considering that these new refrigeration gases work at different pressures, it is possible that the noise could be different with these gases. Moreover, the study of sound quality is very important for the manufacture as the perception and therefore the annoyance could change with the use of new gases. (2) Methods: Two different gases, R-449A and R-134A, have been studied. An acoustic camera has been used to measure and identify the sound quality in the refrigeration systems. (3) Results: The results have shown R-134A has better sound quality than R-449A. (4) Conclusions: This study shows that R-449A and R-134A could be a substitute for R-404A in terms of noise level

    Inverse relation between FASN expression in human adipose tissue and the insulin resistance level

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    <p>Abstract</p> <p>Background</p> <p>Adipose tissue is a key regulator of energy balance playing an active role in lipid storage and may be a dynamic buffer to control fatty acid flux. Just like PPARγ, fatty acid synthesis enzymes such as FASN have been implicated in almost all aspects of human metabolic alterations such as obesity, insulin resistance or dyslipemia. The aim of this work is to investigate how FASN and PPARγ expression in human adipose tissue is related to carbohydrate metabolism dysfunction and obesity.</p> <p>Methods</p> <p>The study included eighty-seven patients which were classified according to their BMI and to their glycaemia levels in order to study FASN and PPARγ gene expression levels, anthropometric and biochemical variables.</p> <p>Results</p> <p>The main result of this work is the close relation between FASN expression level and the factors that lead to hyperglycemic state (increased values of glucose levels, HOMA-IR, HbA1c, BMI and triglycerides). The correlation of the enzyme with these parameters is inversely proportional. On the other hand, PPARγ is not related to carbohydrate metabolism.</p> <p>Conclusions</p> <p>We can demonstrate that FASN expression is a good candidate to study the pathophysiology of type II diabetes and obesity in humans.</p

    Growth of SiO2 Thin Films by Plasma-Assisted Reactive Magnetron Sputtering under the Impingement of Positive and Negative Ions

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    Presentación en la VII Reunión Bienal del Grupo Especializado de Física de Estado SólidoPeer reviewe

    Potential Role of Insulin Growth-Factor-Binding Protein 2 as Therapeutic Target for Obesity-Related Insulin Resistance

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    Evidence from observational and in vitro studies suggests that insulin growth-factor-binding protein type 2 (IGFBP2) is a promising protein in non-communicable diseases, such as obesity, insulin resistance, metabolic syndrome, or type 2 diabetes. Accordingly, great efforts have been carried out to explore the role of IGFBP2 in obesity state and insulin-related diseases, which it is typically found decreased. However, the physiological pathways have not been explored yet, and the relevance of IGFBP2 as an important pathway integrator of metabolic disorders is still unknown. Here, we review and discuss the molecular structure of IGFBP2 as the first element of regulating the expression of IGFBP2. We highlight an update of the association between low serum IGFBP2 and an increased risk of obesity, type 2 diabetes, metabolic syndrome, and low insulin sensitivity. We hypothesize mechanisms of IGFBP2 on the development of obesity and insulin resistance in an insulin-independent manner, which meant that could be evaluated as a therapeutic target. Finally, we cover the most interesting lifestyle modifications that regulate IGFBP2, since lifestyle factors (diet and/or physical activity) are associated with important variations in serum IGFBP2

    El miedo a madurar en mujeres con obesidad mórbida postgastrectomía: predictores clínicos.

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    Analizar la conducta alimentaria en pacientes que son sometidos a cirugía bariátrica. Material y Método: Se administró el Eating Disorder Inventory (EDI) a 85 mujeres con obesidad mórbida intervenidas de cirugía gástrica (gastroplastia vertical bandeada) para perder peso. Resultados: La edad de las pacientes antes de la cirugía y la edad de inicio de la obesidad se relaciona con el Miedo a Madurar del EDI, de forma que cuanto mayor es el paciente y más tarde aparece la obesidad, el miedo a crecer es más intenso. Discusión: Estos hallazgos irían en la dirección de dependencia, inmadurez y miedo a crecer descritos en la población con obesidad mórbida.

    Aspectos clínicos del trastorno por atracón o "binge eating disorder".

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    El trastorno por atracón es un nuevo trastorno alimentario que consiste en episodios repetidos de atracones de comida sin realizar mecanismos compensatorios para evitar ganar peso, como ocurre en la bulimia nerviosa. Analizamos las características clínicas (conducta alimentaria, psicopatología e imagen corporal), instrumentos de medida y tratamiento para el manejo del trastorno por atracó
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