Study of porosity and permeability of air filter material in respiratory proptection filters.

The objective is the study of filtering tissue permeability and the characterization by means of permeability tests, of the process of coal particles retention in breath protection filters.The permeability of nine probes have been measured against partic

“EVOLUCION CLINICA Y RADIOGRAFICA DE LAS FRACTURAS DIAFISARIAS DE TIBIA FRAGMENTADAS MANEJADAS CON CIRUGIA MINIMA INVASIVA”

Las fracturas diafisarias de tibia no pueden ser tratadas mediante un conjunto de reglas. Debido a su localización la tibia está expuesta a lesiones frecuentes, dado que un tercio de su superficie es subcutánea a lo largo de la mayor parte de su longitud, las fracturas abiertas son muy frecuentes en la tibia que en cualquier otro hueso largo, además la irrigación de la tibia es más precaria que la de los otros huesos que están rodeados de una musculatura importante. Las fracturas de alta energía pueden asociarse con síndromes compartimé̩ntales o con lesiones vasculares o nerviosas, la presencia de articulaciones en bisagra en la rodilla y en el tobillo no permiten ninguna tolerancia para la deformidad rotatoria tras la fractura y por lo tanto se debe prestar atención durante la reducción para corregir este tipo de deformidad. Dentro de las complicaciones más frecuentes que podemos encontrar en este tipo de fracturas, son el retardo de la consolidación, la pseudoartrosis y la infecció

Artificial Immune System for Solving Global Optimization Problems

In this paper, we present a novel model of an artificial immune system (AIS), based on the process that suffers the T-Cell. The proposed model is used for global optimization problems. The model operates on four populations: Virgins, Effectors (CD4 and CD8) and Memory. Each of them has a different role, representation and procedures. We validate our proposed approach with a set of test functions taken from the specialized literature, we also compare our results with the results obtained by different bio-inspired approaches and we statistically analyze the results gotten by our approach.Fil: Aragon, Victoria Soledad. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Informática. Laboratorio Investigación y Desarrollo En Inteligencia Computacional; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico San Luis; ArgentinaFil: Esquivel, Susana C.. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Informática. Laboratorio Investigación y Desarrollo en Inteligencia Computacional; ArgentinaFil: Coello Coello, Carlos A.. CINVESTAV-IPN; Méxic

Diferentes niveles y épocas de aplicación de nitrógeno en arroz ( bluebonnet 50 )

Aprovechamiento integral de los suelos de Aracataca en la producción de arroz) bajando los costos, mejorar las calidades, tratar de ayudar a solucionar un problema socio económico promoviendo empleo ya que se presentó una crisis económica, al destruir las plantaciones de banano ( Musa sapientum L.) En el ensayo estudiado se usó la variedad Bluebonnet 50 ( Oriza sativa L.), recomendado por el Instituto Colombiano Agropecuario ICA. según estudio realizado en Palmira ( Valle), ya que posee característica especiales, mencionadas anteriormente; como fuente de Nitrógeno se usó la Urea de 46%, teniendo el ensayo una duración de 150 días, haciendo las labores culturales que el cultivo requiere, el diseño experimental usado fue parcelas divididas con cuatro repeticiones, tres parcelas y ocho subparcelas, la fertilización se llevó a cabo al voleo, en ocho diferentes niveles y tres épocas de aplicación. Según los resultados obtenidos hubo respuesta significativa en relación con el testigo, los resultados pueden verse en las tablas comprendidas entre los números 1 al 8. Las variaciones de temperaturas nocturnas y diurnas tienen incidencia en la producción de arroz, y las temperaturas bajas después del espigamiento disminuyen el peso del grano, el arroz no debe someterse a foto periodo largo, porque afecta la inflorescencia. Al hacer el análisis de la varianza de acuerdo a los rendimientos obtenidos, se encontró que, aplicando 150 kilos a los 30 días, se obtuvo 22 23 la mayor producción, pero se observé que en los niveles más altos de nitrógeno hubo un efecto negativo

Definition of critical hydrodynamic conditions for sediment motion initiation using optical technique

Sediment motion initiation experiments were performed in a glass rectangular channel, with a loose bed in the central part. The main goal is to obtain the critical hydrodynamic characteristics that causes sediment bed motion initiation, for different cohesionless sediment grain sizes. The optical technique of Particle Tracking Velocimetry (PTV) was used in order to determine the critical velocity profiles for sediment initiation of motion. Between the parameters that define this critical velocity profile is the one known as bed rugosity which represents the height of asperities in the bed. For conditions near bed motion initiation experimental velocity profiles were obtained and they allowed us also to define fluctuating velocities u´, v´ and a value of bed rugosity ks related to a representative grain size of the bed. It was shown that obtained critical velocity profiles are in good agreement with other works in the scientific literature provided an appropriate definition of bed rugosity is made.Universidad Autónoma del Estado de Méxic

Identificación de áreas críticas de erosión en el Curso Alto del Río Lerma

El Curso Alto del Río Lerma (carl) tiene una extensión de 2 117.9 km2, presenta en su parte alta, el Volcán Nevado de Toluca, elevaciones de 4 560 msnm y en su parte baja la presa José Antonio Alzate una elevación de 2 569 msnm. La abrupta topografía, las altas precipitaciones y la intervención humana (tala de bosques y prácticas agrícolas inadecuadas), presentes en la cuenca, generan anualmente una importante pérdida de suelo. En este trabajo se identifican las áreas del carl que producen mayor pérdida de suelo. Se hizo un esfuerzo para identificar los municipios más afectados con el fin de instarles a tomar medidas preventivas. Estos municipios corresponden a Santiago Tianguistenco, Lerma y Ocoyoacac que juntos representan 60% de las zonas con grado de erosión extrema. En índices de erosión alta a los anteriores se le suman Otzolotepec, Temoaya, Xalatlaco, Toluca en las faldas del Nevado y Zinacantepec

Robotic navigation algorithm with machine vision

In the field of robotics, it is essential to know the work area in which the agent is going to develop, for that reason, different methods of mapping and spatial location have been developed for different applications. In this article, a machine vision algorithm is proposed, which is responsible for identifying objects of interest within a work area and determining the polar coordinates to which they are related to the observer, applicable either with a fixed camera or in a mobile agent such as the one presented in this document. The developed algorithm was evaluated in two situations, determining the position of six objects in total around the mobile agent. These results were compared with the real position of each of the objects, reaching a high level of accuracy with an average error of 1.3271% in the distance and 2.8998% in the angle

Experimental developments for measuring the initiation of mine fires

A scale model of a dead end gallery has been developed. After heated air flow was introduced, the increase in temperature and gases evolution were monitored. The ventilation was increased and the temperature was elevated to produce an ignition process. Obtained data have shown significant measures of the self ignition mechanism, bringing a valuable tool to predict and early detect the process

Full scale test for explosion water barriers in small cross-section galleries

Underground coal mines explosions generally arise from the inflammation of a methane/air mixture. This explosion can also generate a subsequent coal dust explosion. Traditionally such explosions have being fought eliminating one or several of the factors needed by the explosion to take place. Although several preventive measures are taken to prevent explosions, other measures should be considered to reduce the effects or even to extinguish the flame front. Unlike other protection methods that remove one or two of the explosion triangle elements, namely; the ignition source, the oxidizing agent and the fuel, explosion barriers removes all of them: reduces the quantity of coal in suspension, cools the flame front and the steam generated by vaporization removes the oxygen present in the flame. Passive water barriers are autonomous protection systems against explosions that reduce to a satisfactory safety level the effects of methane and/or flammable dust explosions. The barriers are activated by the pressure wave provoked in the explosion destroying the barrier troughs and producing a uniform dispersion of the extinguishing agent throughout the gallery section in quantity enough to extinguish the explosion flame. Full scale tests have been carried out in Polish Barbara experimental mine at GIG Central Mining Institute in order to determine the requirements and the optimal installation conditions of these devices for small sections galleries which are very frequent in the Spanish coal mines. Full scale tests results have been analyzed to understand the explosion timing and development, in order to assess on the use of water barriers in the typical small crosssection Spanish galleries. Several arrangements of water barriers have been designed and tested to verify the effectiveness of the explosion suppression in each case. The results obtained demonstrate the efficiency of the water barriers in stopping the flame front even with smaller amounts of water than those established by the European standard. According to the tests realized, water barriers activation times are between 0.52 s and 0.78 s and the flame propagation speed are between 75 m/s and 80 m/s. The maximum pressures (Pmax) obtained in the full scale tests have varied between 0.2 bar and 1.8 bar. Passive barriers protect effectively against the spread of the flame but cannot be used as a safeguard of the gallery between the ignition source and the first row of water troughs or bags, or even after them, as the pressure could remain high after them even if the flame front has been extinguished