63 research outputs found

    Aerodynamic characterization of a Griffith-type transonic, laminar-flow airfoil

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    An experimental investigation was conducted at the University of Illinois’ Transonic Wind Tunnel Facility on a Griffith-type transonic airfoil to evaluate the effectiveness of its laminar flow qualities and boundary-layer flow-control characteristics in the transonic regime. Airfoil surface and wake pressure data were acquired to characterize the aerodynamic performance across a range of α = -2˚ to 2˚ and M = 0.3 to 0.7. In addition, surface-oil flow visualization, PIV, and Schlieren imaging were performed to identify the suction influence on boundary-layer transition, momemtum deficit alleviation in the wake, and stability of transonic shocks. It was observed from the pressure distributions that the flow control application had a beneficial influence, allowing for a more aggressive pressure recovery downstream of the suction slot resulting in higher recovery pressure values at the trailing edge. At the design conditions of M = 0.7 and α = 0˚, a net profile drag reduction of 10.70% and an increase in the lift-to-drag ratio of 14.68% were observed when compared to no-suction conditions. Velocity flow field contours obtained from the PIV data showed an increase in the wake velocity magnitude for all Mach numbers at α = 0˚, displaying excellent agreement for the drag data at these conditions. Surface-oil flow visualization experiments revealed that the airfoil experienced extensive laminar flow runs regardless of suction application due to the low-Reynolds number test condition. The laminar flow was found to be shock limited followed by a laminar separation bubble in most cases. From the Schlieren experiments, a characteristic frequency of 22.38 Hz for the shock oscillatory process was identified at the design conditions which also was observed to stabilize under the influence of suction. In general, the improvements in aerodynamic efficiency and stability of the shock resulting from suction were observed to be greatest at higher angles of attack where the boundary layer was subjected to stronger-unforced pressure gradients

    Realización de grabados mediante técnicas digitales y carvado con láser: Técnica de Grabado en linóleo con utilización de Snapmaker

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    El primer planteamiento de esta propuesta de investigación surgió en 2017 el seno de la Galería Weber-Lutgen de Sevilla. Un espacio especializado en el arte contemporáneo más experimental del sur de España. Galería afincada en Sevilla con la que trabajo como artista plástico desde sus inicios y en en la que he realizado numerosas exposiciones en los formatos más diversos (pintura, escultura, vídeo, performance, instalación, etc). Su director es Edouard Weber (www.galeria- wl.eu) es Ingeniero Superior por la Universidad de Aachen, Alemania (Diplom Bauingenieur / Rheinisch Westfälische Tchnische Hochschule Aachen) y galerista desde 2007. La galería adquirió la nueva y asequible herramienta digital Snapmaker, con el fin de ponerla a la disposición de sus artistas. En seguida le planteé la posibilidad de comenzar una investigación para la posible realización de obra gráfica experimental y ediciones de grabado, mediante esta nueva herramienta, ya que permitiría innovadoras posibilidades técnicas. En general, la imagen que tenemo

    Microprocessor board for vitro ceramic control

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    This paper presents the industrial application of a microcontroller for a vitroceramic cooker. The vitroceramic surface is clustered into a matrix with of cells, each one containing one heating resistor and one infrared emitter- receiver pair which detects the presence or absence of a receptacle on its cell. With this information, a microcontroller fires only those resistors arranged under the base of a receptacle. This patented vitroceramic cooker presents many advantages over traditional ones; for instance, power consumption is optimized, as only the useful ceramic surface is heated. Furthermore, when the object is removed from the surface, the heating resistors are powered off, so there is no risk for the fires being left on, which is of great interest for blind people. Acoustic signals can also be generated indicating the existence of heated resistors

    Mortalidad en pacientes con ventilación mecánica ingresados en una Unidad de Cuidados Intensivos

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    Introducción: La ventilación mecánica es un proceder para la sustitución de la ventilación, que salva la vida de pacientes con insuficiencia respiratoria aguda, al mismo tiempo es una de las primeras causas de complicaciones y de mortalidad.Objetivo: Identificar las características clínico-epidemiológicas en pacientes fallecidos con ventilación mecánica, ingresados en la UCI del hospital Joaquín Albarrán Domínguez en el trienio 2013-2015. Material y Métodos: Se realizó un estudio descriptivo, transversal, con las historias clínicas de dichos pacientes, recopilando la información en una matriz de datos y posteriormente fue analizada con el software SPSS 21.0, a través de frecuencias absolutas y relativas y con la utilización de la prueba de chi2 para las correlaciones bi-variadas, tomando como valor de significación estadística p&lt; 0,05.Resultados: De los 166 pacientes, el 49,4% superaba los 70 años. La EPOC fue el motivo de ventilación más frecuente. Las mayores complicaciones de la ventilación fueron: fallo multiorgánico 25,3%, fallo al destete 21,6%, y distrés respiratorio 20,4%.Conclusiones: El fallo multiorgánico, las bronconeumonías bacterianas bilaterales y la neumonía asociada a la ventilación mecánica, fueron las principales complicaciones y causas de muerte más frecuentes en los pacientes ventilados.Palabras clave: mortalidad, ventilación mecánica, cuidados intensivos, complicaciones, paciente grave.</p

    Plasma levels of mitochondrial and nuclear DNA in patients with massive pulmonary embolism in the emergency department: A prospective cohort study

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    Introduction: Cell-free plasma mitochondrial DNA (mt-DNA) and nuclear DNA (n-DNA) are biomarkers with prognostic utility in conditions associated with a high rate of cell death. This exploratory study aimed to determine the plasma levels of both nucleic acids in patients with massive and submassive pulmonary embolism (PE) and to compare them with other biomarkers, such as heart-type fatty acid-binding protein (H-FABP) and troponin I (Tn-I) Methods: This was a prospective observational study of 37 consecutive patients with massive PE, 37 patients with submassive PE, and 37 healthy subjects. Quantifications of plasma mt-DNA and n-DNA with real-time quantitative polymerase chain reaction (PCR), and plasma H-FABP and Tn-I by commercial assays, were done on blood samples drawn within 4 hours after presentation at the emergency department. Results: Plasma mt-DNA and n-DNA concentrations were much higher in patients with massive PE (median, 2,970 GE/ml; interquartile range (IQR), 1,050 to 5,485; and 3,325 GE/ml, IQR: 1,080 to 5,790, respectively) than in patients with submassive PE (870 GE/ml and 1,245 GE/ml, respectively; P < 0.01) or controls (185 GE/ml and 520 GE/ml, respectively). Eighteen patients with massive PE died of a PE-related cause by day 15 of observation. Plasma mt- DNA and n-DNA values were 2.3-fold and 1.9-fold higher in the subgroup of nonsurviving patients than in survivors. H-FABP and Tn-I values were also higher in patients with massive PE who died (7.3 ng/ml and 0.023 ng/ml, respectively) than in those who survived (6.4 ng/ml, and 0.016 ng/ml, respectively). By receiver operating curve (ROC) analysis, the best cutoff values for predicting 15-day mortality were 3,380 GE/ml for mt-DNA, 6.8 ng/ml for H-FABP, 3,625 GE/ml for n-DNA, and 0.020 ng/ml for Tn-I, based on the calculated areas under the curve (AUCs) of 0.89 (95% confidence interval (CI), 0.78 to 0.99), 0.76 (95% CI, 0.69 to 093), 0.73 (95% CI, 0.58 to 0.91), and 0.59 (95% CI, 0.41 to 0.79), respectively. By stepwise logistic regression, a plasma mt-DNA concentration greater than 3,380 GE/ml (adjusted odds ratio (OR), 8.22; 95% CI, 1.72 to 39.18; P 6.8 ng/ml (OR, 5.36; 95% CI, 1.06 to 27.08; P < 0.01) were the only independent predictors of mortality. Conclusions: mt-DNA and H-FBAP might be promising markers for predicting 15-day mortality in massive PE, with mt-DNA having better prognostic accuracy.This work was supported partially by grants from Plan Nacional I+D+I (SAF 2008-05347 and SAF2011-23575) and from Fundación Mutua Madrileña de Investigación Biomédica (2008 and 2011) to Francisco Arnalich and Carmen Montie

    Eficacia de la ivermectina y del albendazol sulfóxido para el control de nematodos gastrointestinales en ovejas Pelibuey

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    A study was conducted to evaluate the efficacy of ivermectin and albendazole sulfoxide for the control of gastrointestinal nematodes. Thirty Pelibuey ewes were randomly assigned to three experimental groups: Ivermectin 4% (10.2 mg/kg), albendazole sulfoxide 17% (3.75 mg/kg) and an untreated control group. Faecal samples were collected before drug administration (day 0) and on days 7, 14, 21, 28, 35, and 42 post-treatment. The quantitative diagnosis of the eggs was carried out using the McMaster technique and cultures were carried out to recover larvae by the migration method with the Baermann apparatus. The anthelmintic efficacy of the treatments was determined by the Abbott's formula and the effect of anthelmintics on the number of eggs per gram of faeces (EPG) by an analysis of variance with a completely randomized design. The most abundant species were Haemonchus contortus and Strongyloides papillosus. A significant decrease in the amount of EPG was observed from day 7 of treatment with both anthelmintics, with albendazole sulfoxide and ivermectin showing efficacy above 95% from day 7 and 14 post-treatment, respectively, until day 21. At 24 h post-treatment, ivermectin showed lower efficacy than albendazole sulfoxide (69.5 vs 90.9% respectively), but efficacy was similar and above 90% for both drugs from day 7. The efficacy of lbendazole sulfoxide against Haemonchus contortus larvae was 88.2% at 24 h post-treatment compared to 69.5% for ivermectin, but only the latter showed an efficacy greater than 95% on days 14 and 21 post-administration. It is concluded that albendazole sulfoxide has a faster effect and a longer efficacy for the control of gastrointestinal nematode eggs, while ivermectin showed greater efficacy for the control of Haemonchus contortus larvae without evidence of resistance to both drugs.Se realizó un estudio para evaluar la eficacia de la ivermectina y del albendazol sulfóxido para el control de nematodos gastrointestinales. Treinta ovejas Pelibuey fueron asignadas aleatoriamente a tres grupos experimentales: ivermectina al 4% (10.2 mg/kg), albendazol sulfóxido al 17% (3.75 mg/kg) y un grupo control no tratado. Se recolectaron muestras fecales antes de la administración de los fármacos (día 0) y en los días 7, 14, 21, 28, 35 y 42 pos-tratamiento. Se realizó el diagnóstico cuantitativo de los huevos mediante la técnica de McMaster y se realizaron cultivos para recuperar larvas por el método de migración con el aparato de Baermann. La eficacia antihelmíntica de los tratamientos se determinó por medio de la fórmula de Abbott y el efecto de los antihelmínticos sobre la cantidad de huevos por gramos de heces (HPG) por medio de un análisis de varianza con un diseño completamente al azar. Las especies más abundantes fueron Haemonchus contortus y Strongyloides papillosus. Se observó una disminución significativa en la cantidad de HPGH a partir del día 7 del tratamiento con ambos fármacos, mostrando el albendazol sulfóxido y la ivermectina una eficacia por encima del 95% a partir del día 7 y 14 postratamiento, respectivamente, hasta el día 21. La eficacia del albendazol sulfóxido contra larvas de Haemonchus contortus fue de 88.2% a las 24 h pos-tratamiento en comparación con el 69.5% de la ivermectina, pero solo esta última mostró una eficacia superior al 95% los días 14 y 21 postadminstración. Se concluye que el albendazol sulfóxido tiene un efecto más rápido y una eficacia más prolongada para el control de huevos de nemátodos gastrointestinales, mientras que la ivermectina mostró una mayor eficacia para el control de larvas de Hamonchus contortus sin indicios de resistencia a ambos fármacos

    Efeito da compactação do solo pelo tráfego de máquinas na configuração dos poros do solo

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    Soil compaction has been recognized as a severe problem in mechanized agriculture and has an influence on many soil properties and processes. Yet, there are few studies on the long-term effects of soil compaction, and the development of soil compaction has been shown through a limited number of soil parameters. The objectives of this study were to evaluate the persistence of soil compaction effects (three traffic treatments: T0, without traffic; T3, three tractor passes; and T5, five tractor passes) on pore system configuration, through static and dynamic determinations; and to determine changes in soil pore orientation due to soil compaction through measurement of hydraulic conductivity of saturated soil in samples taken vertically and horizontally. Traffic led to persistent changes in all the dynamic indicators studied (saturated hydraulic conductivity, K0; effective macro- and mesoporosity, εma and εme), with significantly lower values of K0, εma, and εme in the T5 treatment. The static indicators of bulk density (BD), derived total porosity (TP), and total macroporosity (θma) did not vary significantly among the treatments. This means that machine traffic did not produce persistent changes on these variables after two years. However, the orientation of the soil pore system was modified by traffic. Even in T0, there were greater changes in K0 measured in the samples taken vertically than horizontally, which was more related to the presence of vertical biopores, and to isotropy of K0 in the treatments with machine traffic. Overall, the results showed that dynamic indicators are more sensitive to the effects of compaction and that, in the future, static indicators should not be used as compaction indicators without being complemented by dynamic indicators.Facultad de Ciencias Agrarias y Forestale

    Gypsum soil amendment: modification of its chemical, physical and biological properties

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    Los suelos sódicos ocupan una extensa proporción de la Depresión del Salado. El sodio aumenta el pH y provoca la dispersión de las arcillas generando modificaciones en la estructura de los suelos que perjudican el crecimiento de los cultivos al reducir su porosidad y su infiltración. La aplicación de yeso puede mejorar las características de los suelos sódicos. Se realizó un ensayo en el que se aplicaron tres dosis de yeso: A) 0 kg/ha (testigo); B) 100 kg/ha (en la línea de siembra) y C) 12000 kg/ha (en cobertura total). Se replicó el ensayo usando dos cultivos: Festuca (Festuca arundinacea Schreb.) y Agropiro (Thynopirum ponticum Barkworth & D.R.Dewey). En los distintos tratamientos se midieron propiedades químicas (pH, conductividad eléctrica, porcentaje de sodio intercambiable (PSI) y carbono orgánico), físicas (resistencia a la penetración, resistencia al corte, densidad aparente e infiltración) y biológicas (porcentaje de implantación y productividad primaria neta). El yeso redujo el pH, aumentó la conductividad eléctrica y redujo el PSI. Además, no modificó la resistencia al corte del suelo, pero sí aumentó su capacidad portante en una situación de elevada humedad y mejoró su conductividad hidráulica. Si bien todos estos cambios mejoraron el porcentaje de implantación de ambos cultivos no se modificó la producción de materia seca.Sodic soils occupy a large proportion of the Salado Depression. Sodium increases the pH and causes the dispersion of the clays, generating modifications in the structure of soils that harm the growth of crops by reducing their porosity and infiltration. The application of gypsum can improve the characteristics of sodic soils. A test was carried out in which three doses of gypsum were applied: A) 0 kg/ha (control); B) 100 kg/ha (in the seeding line) and C) 12000 kg/ha (in full coverage). The test was replicated using two crops: Fescue (Festuca arundinacea Schreb.) and Agropiro (Thynopirum ponticum Barkworth & D.R.Dewey). In the different treatments, chemical (pH, electrical conductivity, exchangeable sodium percentage (ESP) and organic carbon), physical (penetration resistance, shear resistance, bulk density and infiltration) and biological (percentage of implantation and net primary productivity) were measured. Gypsum lowered pH, increased electrical conductivity, and lowered ESP. In addition, it did not modify the shear resistance of the soil, but it did increase its load-bearing capacity in a situation of high humidity and improved its hydraulic conductivity. Although all these changes improved the implantation percentage of both crops, dry matter production was not modified.Facultad de Ciencias Agrarias y Forestale

    Gypsum soil amendment: Modification of its chemical, physical and biological properties

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    Los suelos sódicos ocupan una extensa proporción de la Depresión del Salado. El sodio aumenta el pH y provoca la dispersión de las arcillas generando modificaciones en la estructura de los suelos que perjudican el crecimiento de los cultivos al reducir su porosidad y su infiltración. La aplicación de yeso puede mejorar las características de los suelos sódicos. Se realizó un ensayo en el que se aplicaron tres dosis de yeso: A) 0 kg/ha (testigo); B) 100 kg/ha (en la línea de siembra) y C) 12000 kg/ha (en cobertura total). Se replicó el ensayo usando dos cultivos: Festuca (Festuca arundinacea Schreb.) y Agropiro (Thynopirum ponticum Barkworth & D.R.Dewey). En los distintos tratamientos se midieron propiedades químicas (pH, conductividad eléctrica, porcentaje de sodio intercambiable (PSI) y carbono orgánico), físicas (resistencia a la penetración, resistencia al corte, densidad aparente e infiltración) y biológicas (porcentaje de implantación y productividad primaria neta). El yeso redujo el pH, aumentó la conductividad eléctrica y redujo el PSI. Además, no modificó la resistencia al corte del suelo, pero sí aumentó su capacidad portante en una situación de elevada humedad y mejoró su conductividad hidráulica. Si bien todos estos cambios mejoraron el porcentaje de implantación de ambos cultivos no se modificó la producción de materia seca.Sodic soils occupy a large proportion of the Salado Depression. Sodium increases the pH and causes the dispersion of the clays, generating modifications in the structure of soils that harm the growth of crops by reducing their porosity and infiltration. The application of gypsum can improve the characteristics of sodic soils. A test was carried out in which three doses of gypsum were applied: A) 0 kg/ha (control); B) 100 kg/ha (in the seeding line) and C) 12000 kg/ha (in full coverage). The test was replicated using two crops: Fescue (Festuca arundinacea Schreb.) and Agropiro (Thynopirum ponticum Barkworth & D.R.Dewey). In the different treatments, chemical (pH, electrical conductivity, exchangeable sodium percentage (ESP) and organic carbon), physical (penetration resistance, shear resistance, bulk density and infiltration) and biological (percentage of implantation and net primary productivity) were measured. Gypsum lowered pH, increased electrical conductivity, and lowered ESP. In addition, it did not modify the shear resistance of the soil, but it did increase its load-bearing capacity in a situation of high humidity and improved its hydraulic conductivity. Although all these changes improved the implantation percentage of both crops, dry matter production was not modified.Fil: Melani, Esteban Miguel. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Guilino, Facundo Daniel. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Draghi, Laura Monica. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Jorajuria Collazo, Daniel. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Villarreal, Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lozano, Luis Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Soracco, Carlos Germán. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Palancar, Telmo Cecilio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Soil loosening persistence with paratill

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    En la Argentina predomina como sistema productivo la siembra directa donde la ausencia de remoción y el tránsito de máquinas cada vez más pesadas han incrementado los problemas de compactación. Para revertir este fenómeno se utilizan descompactadores. Existen datos dispares de cuán prolongada es la duración del efecto de descompactación. Se realizó un ensayo utilizando un descompactador angulado lateral (Paratill) en un suelo Hapludol Thapto Árgico. A los dos años se evaluó la resistencia a la penetración, la densidad aparente, la infiltración y la producción de materia seca comparando el tratamiento descompactado con el testigo (sin descompactar). No se encontraron diferencias en densidad aparente ni en infiltración entre ambos tratamientos. Hubo diferencias en la resistencia a la penetración donde el tratamiento testigo alcanzó valores mayores al descompactado en parte del perfil trabajado y aún debajo de la profundidad máxima alcanzada. La materia seca producida en el tratamiento descompactado duplicó a la del testigo evidenciando que el efecto de la descompactación se mantiene dos años después de realizada. Se concluye que el efecto de la descompactación se evidencia aún dos años después de efectuada en el parámetro resistencia a la penetración y que el cultivo percibe estos efectos.In Argentina, no-tillage is the main management system where the absence of soil disturbance and the traffic of heavy machine has increased the problems of soil compaction. In order to reverse this phenomenon, decompaction is used, with contradictory results on the duration of the effect of soil loosing. The study was performed using a lateral angled decompactor (Paratill) in a Thapto Argic Hapludol. After two years, penetration resistance, bulk density, infiltration and dry matter production was evaluated under two treatments: decompacted; and control (without decompaction). No differences were found in bulk density or infiltration between treatments. Along the studied soil profile, the control treatment showed higher values of penetration resistance in comparison with the decompacted only between 7 and 30 cm, even below the maximum depth reached. Dry matter was higher under decompaction treatment, showing that the effect of decompaction was maintained two years after its application. In conclusion, the effect of decompaction is still evident after two years, improving the penetration resistance parameter and crop biomass production.Facultad de Ciencias Agrarias y Forestale
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