Modelado de la combustión en motores Diésel: revisión del estado del arte

ResumenEl estudio del proceso de combustión en motores Diésel ha sido, durante años, un tema de gran interés debido principalmente a la creciente necesidad de mejorar el rendimiento de los motores, reducir el consumo de combustible y reducir la emisión de contaminantes. Los estudios experimentales presentan la desventaja de requerir grandes recursos económicos y tiempo en su realización, razón por la cual se utilizan modelos computacionales que permiten estudiar el proceso de combustión de una forma más económica y práctica. En este artículo se presenta una revisión de varios de los modelos de combustión en motores Diésel más  relevantes, desarrollados a nivel nacional e  internacional, con el fn de dar al lector una visión de la evolución y el estado actual de este tipo de modelos.Palabras clave: modelado de la combustión, motores diesel, modelos termodinámicos, modelos multidimensionales.  Modelling of combustion in Diesel engines: a review of the state of the artAbstractThe study of the combustion process in Diesel engines has been for years a subject of great interest mainly due to the increasing need to improve engine performance, reduce fuel consumption and reduce the pollutant emissions. Experimental studies have the disadvantage of require enormous efforts, money and time, that is the reason why computer models are used to study the combustion process in a more economical and practical way. This article presents a review of the most relevant Diesel engine combustion models developed nationally and internationally, to give the reader an insight of the evolution and current status of such modelsKeywords: combustion modeling, diesel engines, thermodynamics models, multidimensional models

Analytical and experimental performance study of diesel engines powered with hydrotreated Bio-Oil

Due to the serious problems encountered because of the extensive use of first-generation biofuels, second generation biofuels are presented as one of the best possible alternatives conventional fuels from oil. This paper presents a theoretical study of the performance of diesel engines fueled with hydrotreated bio-oil from lignocellulosic biomass, which is a second generation biofuel. For this, a thermodynamic zero-dimensional combustion model simulation was carried out, which predicts the performance parameters of the engine. This model was validated against experimental data of two diesel engines fueled with diesel-biodiesel  and  diesel/hydrotreated  bio-oil  blends, and  a  good  correlation between simulated and experimental data was observed, with average relative errors in pressure peak values of 0.5 and 1%, respectively. The results show that hydrotreated bio-oil in small proportions could become a partial substitute for conventional diesel fuel.Debido a los graves problemas presentados a causa del amplio uso de biocombustibles de primera generación, los biocombustibles de segunda generación se presentan como una posible mejor alternativa para la sustitución de los combustibles convencionales provenientes del petróleo. En el presente artículo se presenta un estudio del desempeño de motores diésel alimentados con bio-oil hidrotratado proveniente de biomasa lignocelulósica, el cual es un biocombustible de segunda generación; para esto se desarrolló un modelo termodinámico cero-dimensional de la combustión que predice los parámetros de desempeño del motor. Este modelo fue validado contra datos experimentales de presión en cámara de dos motores diésel alimentados con mezclas diésel/biodiésel y diésel/bio-oil hidrotratado, observándose una buena correlación entre los datos simulados y experimentales, con errores relativos promedio en los valores pico de presión de 0,5 y 1 % respectivamente. Los resultados muestran que el bio-oil hidrotratado, al utilizarse en pequeñas proporciones, puede convertirse en un sustituto parcial del combustible diésel convencional. &nbsp

Cariotipos fetales en embarazos de alto riesgo genético provenientes de hospitales de la seguridad social y de la consulta privada, de 1993 a 1998

Artículo científico -- Universidad de Costa Rica, Instituto de Investigaciones en Salud. 2000El objetivo de este estudio fue identificar cromosomopatía fetal en voluntarias con embarazos de alto riesgo genético, a fin de brindar adecuada atención obstétrica y pediátrica y asesoramiento genético. Las células fetales se obtuvieron mediante amniocentesis (N=506) y cordocentesis (N=46) desde 1993 pasta 1998 inclusive. Ambas punciones fueron transabdominales. guiadas por ultrasonografía y se realizaron en los hospitales Calderón Guardia (63% de las amniocentesis y 45 cordocentesis), México (21% de las amniocentesis y una cordocentesis), en la consulta privada (12%) y otros hospitales. La indicación del 62% de las amniocentesis y de casi codas las cordocentesis fue el examen ultrasonográfico anormal y el 23% de Ias punciones fue por edad materna avanzada. El 66% de las veces el estudio se realiza en la segunda mitad del embarazo. De las 552 muestras de líquido amniótico y sangre fetal, en 109 no fue posible obtener resultados. Los 443 cariotipos fetales obtenidos fueron anormales en 39 casos (9%): 21 cariotipos trisdmicos, ocho casos con síndrome de Turner (45.X). tres mosaicos cromoseirnicos y siete cariotipos anormales por otras causas. El resultado final se obtuvo en 15 días (mediana). En el seguimiento de los casos se encontr6 concordancia entre el cariotipo y el fenotipo del recién nacido, al igual que entre el diagnostico ultrasonográfico fetal y Ia condición del neonato. El diagnostico prenatal de cromosomopatía permitió el asesoramiento genético y el manejo obstétrico y pediátrico de los casos de mama adecuada. En los embarazos con cariotipo normal, esta información alivió Ia preocupación de muchos de los padres.Universidad de Costa Rica. Instituto de Investigaciones en SaludUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Analytical and experimental performance study of diesel engines powered with hydrotreated Bio-Oil

Due to the serious problems encountered because of the extensive use of first-generation biofuels, second generation biofuels are presented as one of the best possible alternatives conventional fuels from oil. This paper presents a theoretical study of the performance of diesel engines fueled with hydrotreated bio-oil from lignocellulosic biomass, which is a second generation biofuel. For this, a thermodynamic zero-dimensional combustion model simulation was carried out, which predicts the performance parameters of the engine. This model was validated against experimental data of two diesel engines fueled with diesel-biodiesel  and  diesel/hydrotreated  bio-oil  blends, and  a  good  correlation between simulated and experimental data was observed, with average relative errors in pressure peak values of 0.5 and 1%, respectively. The results show that hydrotreated bio-oil in small proportions could become a partial substitute for conventional diesel fuel.Debido a los graves problemas presentados a causa del amplio uso de biocombustibles de primera generación, los biocombustibles de segunda generación se presentan como una posible mejor alternativa para la sustitución de los combustibles convencionales provenientes del petróleo. En el presente artículo se presenta un estudio del desempeño de motores diésel alimentados con bio-oil hidrotratado proveniente de biomasa lignocelulósica, el cual es un biocombustible de segunda generación; para esto se desarrolló un modelo termodinámico cero-dimensional de la combustión que predice los parámetros de desempeño del motor. Este modelo fue validado contra datos experimentales de presión en cámara de dos motores diésel alimentados con mezclas diésel/biodiésel y diésel/bio-oil hidrotratado, observándose una buena correlación entre los datos simulados y experimentales, con errores relativos promedio en los valores pico de presión de 0,5 y 1 % respectivamente. Los resultados muestran que el bio-oil hidrotratado, al utilizarse en pequeñas proporciones, puede convertirse en un sustituto parcial del combustible diésel convencional. &nbsp

Hematological parameters in Oreochromis niloticus cultivated in tropical conditions in experimental farm Santo Domingo of University of Amazonia, Florencia, Caquetá, Colombia.

The hematological parameters were evaluated in the Oreochromis niloticus species, weighing between 120 and 375 g, where chemical standards of water were included (T °, pH and OD), morphometry and haematological diagnosis, carried out at the Santo Domingo Experimental Farm from the University of the Amazonia, Florencia - Caquetá-Colombia. A directed and completely random sampling of 32 individuals was used, the blood was extracted by cardiac puncture and placed in Eppendorf tubes with EDTA. Blood smears were stained with Ema staining color for its laboratory analysis. The InfoStat was applied as a statistical method for the analysis of the variables to be measured. A total of leukocytes of 1.11 celx105 / mm3 was found, predominating neutrophils with 49.3% followed by lymphocytes with 38.8%, monocytes with 5.9%, eosinophils with 4.3%, basophils with 1.7 % and thrombocytes with 63.8% as an independent series. For the red series, an average of erythrocytes of 1.5 celx106 / mm3, hemoglobin of 7.9 g / dL; hematocrit of 23.3%, plasma proteins 3.3 g / dL, mean corpuscular volume 165 (u3), mean corpuscular hemoglobin 55 (uug) and mean corpuscular hemoglobin concentration of 33.3%. In conclusion, it was determined that some individuals presented Leukopenia with Lymphopenia and thrombocytosis. In addition, two individuals presented Normochromic Microcytic Anemia (AMN) and 19 individuals presented Normochromic Normocitic Anemia (ANN). The analysis of Total Plasma Proteins (PPT) determined that the high mortality rate was not due to nutritional deficiency. There was a positive similarity between the VCM and HCM, and negatively with the total number of erythrocytes.The hematological parameters were evaluated in the Oreochromis niloticus species, weighing between 120 and 375 g, where chemical standards of water were included (T °, pH and OD), morphometry and haematological diagnosis, carried out at the Santo Domingo Experimental Farm from the University of the Amazonia, Florencia - Caquetá-Colombia. A directed and completely random sampling of 32 individuals was used, the blood was extracted by cardiac puncture and placed in Eppendorf tubes with EDTA. Blood smears were stained with Ema staining color for its laboratory analysis. The InfoStat was applied as a statistical method for the analysis of the variables to be measured. A total of leukocytes of 1.11 celx105 / mm3 was found, predominating neutrophils with 49.3% followed by lymphocytes with 38.8%, monocytes with 5.9%, eosinophils with 4.3%, basophils with 1.7 % and thrombocytes with 63.8% as an independent series. For the red series, an average of erythrocytes of 1.5 celx106 / mm3, hemoglobin of 7.9 g / dL; hematocrit of 23.3%, plasma proteins 3.3 g / dL, mean corpuscular volume 165 (u3), mean corpuscular hemoglobin 55 (uug) and mean corpuscular hemoglobin concentration of 33.3%. In conclusion, it was determined that some individuals presented Leukopenia with Lymphopenia and thrombocytosis. In addition, two individuals presented Normochromic Microcytic Anemia (AMN) and 19 individuals presented Normochromic Normocitic Anemia (ANN). The analysis of Total Plasma Proteins (PPT) determined that the high mortality rate was not due to nutritional deficiency. There was a positive similarity between the VCM and HCM, and negatively with the total number of erythrocyte

Hematological parameters in Oreochromis niloticus cultivated in tropical conditions in experimental farm Santo Domingo of University of Amazonia, Florencia, Caquetá, Colombia.

The hematological parameters were evaluated in the Oreochromis niloticus species, weighing between 120 and 375 g, where chemical standards of water were included (T °, pH and OD), morphometry and haematological diagnosis, carried out at the Santo Domingo Experimental Farm from the University of the Amazonia, Florencia - Caquetá-Colombia. A directed and completely random sampling of 32 individuals was used, the blood was extracted by cardiac puncture and placed in Eppendorf tubes with EDTA. Blood smears were stained with Ema staining color for its laboratory analysis. The InfoStat was applied as a statistical method for the analysis of the variables to be measured. A total of leukocytes of 1.11 celx105 / mm3 was found, predominating neutrophils with 49.3% followed by lymphocytes with 38.8%, monocytes with 5.9%, eosinophils with 4.3%, basophils with 1.7 % and thrombocytes with 63.8% as an independent series. For the red series, an average of erythrocytes of 1.5 celx106 / mm3, hemoglobin of 7.9 g / dL; hematocrit of 23.3%, plasma proteins 3.3 g / dL, mean corpuscular volume 165 (u3), mean corpuscular hemoglobin 55 (uug) and mean corpuscular hemoglobin concentration of 33.3%. In conclusion, it was determined that some individuals presented Leukopenia with Lymphopenia and thrombocytosis. In addition, two individuals presented Normochromic Microcytic Anemia (AMN) and 19 individuals presented Normochromic Normocitic Anemia (ANN). The analysis of Total Plasma Proteins (PPT) determined that the high mortality rate was not due to nutritional deficiency. There was a positive similarity between the VCM and HCM, and negatively with the total number of erythrocytes.The hematological parameters were evaluated in the Oreochromis niloticus species, weighing between 120 and 375 g, where chemical standards of water were included (T °, pH and OD), morphometry and haematological diagnosis, carried out at the Santo Domingo Experimental Farm from the University of the Amazonia, Florencia - Caquetá-Colombia. A directed and completely random sampling of 32 individuals was used, the blood was extracted by cardiac puncture and placed in Eppendorf tubes with EDTA. Blood smears were stained with Ema staining color for its laboratory analysis. The InfoStat was applied as a statistical method for the analysis of the variables to be measured. A total of leukocytes of 1.11 celx105 / mm3 was found, predominating neutrophils with 49.3% followed by lymphocytes with 38.8%, monocytes with 5.9%, eosinophils with 4.3%, basophils with 1.7 % and thrombocytes with 63.8% as an independent series. For the red series, an average of erythrocytes of 1.5 celx106 / mm3, hemoglobin of 7.9 g / dL; hematocrit of 23.3%, plasma proteins 3.3 g / dL, mean corpuscular volume 165 (u3), mean corpuscular hemoglobin 55 (uug) and mean corpuscular hemoglobin concentration of 33.3%. In conclusion, it was determined that some individuals presented Leukopenia with Lymphopenia and thrombocytosis. In addition, two individuals presented Normochromic Microcytic Anemia (AMN) and 19 individuals presented Normochromic Normocitic Anemia (ANN). The analysis of Total Plasma Proteins (PPT) determined that the high mortality rate was not due to nutritional deficiency. There was a positive similarity between the VCM and HCM, and negatively with the total number of erythrocyte

Recognition and activation of the plant AkT1 potassium channel by the kinase CIPK23

Plant growth largely depends on the maintenance of adequate intracellular levels of potassium (K1). The families of 10 Calcineurin B-Like (CBL) calcium sensors and 26 CBL-Interacting Protein Kinases (CIPKs) of Arabidopsis (Arabidopsis thaliana) decode the calcium signals elicited by environmental inputs to regulate different ion channels and transporters involved in the control of K1 fluxes by phosphorylation-dependent and -independent events. However, the detailed molecular mechanisms governing target specificity require investigation. Here, we show that the physical interaction between CIPK23 and the noncanonical ankyrin domain in the cytosolic side of the inward-rectifier K1 channel AKT1 regulates kinase docking and channel activation. Point mutations on this domain specifically alter binding to CIPK23, enhancing or impairing the ability of CIPK23 to regulate channel activity. Our data demonstrate the relevance of this protein–protein interaction that contributes to the formation of a complex between CIPK23/CBL1 and AKT1 in the membrane for the proper regulation of K1 transport

CoQ deficiency causes disruption of mitochondrial sulfide oxidation, a new pathomechanism associated with this syndrome

Coenzyme Q (CoQ) is a key component of the mitochondrial respiratory chain, but it also has several other functions in the cellular metabolism. One of them is to function as an electron carrier in the reaction catalyzed by sulfide:quinone oxidoreductase (SQR), which catalyzes the first reaction in the hydrogen sulfide oxidation pathway. Therefore, SQR may be affected by CoQ deficiency. Using human skin fibroblasts and two mouse models with primary CoQ deficiency, we demonstrate that severe CoQ deficiency causes a reduction in SQR levels and activity, which leads to an alteration of mitochondrial sulfide metabolism. In cerebrum of Coq9R239X mice, the deficit in SQR induces an increase in thiosulfate sulfurtransferase and sulfite oxidase, as well as modifications in the levels of thiols. As a result, biosynthetic pathways of glutamate, serotonin, and catecholamines were altered in the cerebrum, and the blood pressure was reduced. Therefore, this study reveals the reduction in SQR activity as one of the pathomechanisms associated with CoQ deficiency syndrome.This work was supported by grants from Ministerio de Economía y Competitividad, Spain, and the ERDF (SAF2013-47761-R, SAF2014-55523-R, RD12/0042/0011 and SAF201565786-R), from the Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (P10-CTS-6133), from the NIH (P01HD080642) and from the foundation “todos somos raros, todos somos únicos”. MLS is a predoctoral fellow from the Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía. LCL is supported by the “Ramón y Cajal” National Programme, Ministerio de Economía y Competitividad, Spain (RYC-2011-07643)

Determinación de la tasa de regeneración en heridas cutáneas aplicando células madre mesenquimales derivadas de tejido adiposo en un andamio de origen biológico

Proyecto de Investigación (Código: 1510097) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Biología, 2019En los últimos años se ha evidenciado que el uso de células madre mesenquimales de tejido adiposo (ADSC) contribuye a la regeneración de la piel ante diferente tipo de heridas, estimulando a las células que proliferen y a que el tejido lesionado recupere su estructura normal. Debido a las complicaciones que resultan de heridas en la piel causadas por quemaduras o bien úlceras resulta necesaria la implementación de terapias alternativas que mejoren la regeneración. Por ello se buscó comprobar el potencial regenerador de las ADSC. Para esto se emplearon 5 grupos de roedores a los que se les realizó una herida cutánea y se les aplicó los siguientes tratamientos: solución salina como control negativo, ADSC en suspensión, un andamio de agarosa, un andamio de agarosa con ADSC, y finalmente un producto comercial como control positivo. Se calculó la tasa de cierre de la herida y se realizaron análisis histológicos. Aunque no hubo diferencias significativas en el tiempo de cierre de la herida entre los diferentes tratamientos, a nivel histológico si se evidenció que aquellos grupos tratados con ADSC presentaron un mejor proceso regenerativo que el resto de los tratamientos, principalmente observado en una menor inflamación, ausencia de paraqueratosis y mayor retracción de la herida, indicando así el potencial regenerativo de estas células en lesiones de piel