Influência de Fatores Ambientais em Diferentes Escalas Espaciais Sobre a Distribuição de Simulídeos (diptera; Nematocera) em Córregos Tropicais

Os simulídeos são insetos com ampla distribuição geográfica que cujos imaturos necessitam de ambientes lóticos para sobreviverem. Suas larvas vivem presas a diversos substratos como folhas, galhos, rochas submersas onde se alimentam de detritos e fitoplâncton, os quais são filtrados através de seus leques cefálicos. São conhecidos vulgarmente como piuns ou borrachudos, sendo que no Brasil são conhecidas 88 espécies. Os insetos adultos possuem hábito hematófago, sendo que algumas espécies têm preferência por sangue humano. O objetivo desse trabalho foi analisar quais os fatores são responsáveis pela distribuição espacial das espécies de simulídeos em córregos tropicais do estado do Espírito Santo, verificar se riqueza e a distribuição de espécies nas regiões de planícies e nas regiões de planalto são diferenciadas, bem como prover uma lista atualizada das espécies registradas para o estado. Foram realizadas 93 incursões em rios do Espírito Santo e as coletas foram realizadas por meio da catação manual e utilização de rede D. Os exemplares foram acondicionados em frascos contendo álcool 92.6% e posteriormente identificados ao nível de espécie em laboratório. Vinte e nove espécies de simulídeos foram coletadas, sendo 12 novos registros para o Estado e um também para a região Sudeste: Simulium scutistriatum, S. dinellii, S. exiguum, S. minusculum, S. distinctum, S. oyapockense s.l., S. rappae, S. botulibranchium, S. ochraceum, S. clavibranchium, Lutzsimulium hirticosta, S. lobatoi, S. pertinax, S. jujuyense, S. rubrithorax, S. travassosi, S. subnigrum, S. spinibranchium, S. anamariae, S. hirtipupa, S. lutzianum, S. nigrimanun, S. incrustatum, S. inaequale, S. subpallidum, S. perflavum, S. brachycladum, S. guianense e S. limbatum. A análise de correspondência destendenciada (DCA) apontou a formação de dois agrupamentos estatísticamente significantes. A variável altitude explica inversamente a riqueza, a abundância e a composição, já a largura explica a composição do eixo 1. Para a análise por espécies foi verificado que algumas respondem à velocidade (S. hirtipupa e S. pertinax), outras ao substrato (S. dinelli, S. hirtipupa, S. guianense e S. subpallidum), enquanto outras à altitude (S. dinelli, S.guianense e S. subpallidum)

Cortante-fricción de los hormigones reciclados

The aim of this research was to determine the behavior of recycled concrete in response to the phenomenon of shear transfer. To perform it, a conventional control concrete and a concrete with 50% recycled coarse aggregate were designed. An additional goal was to shed light on how this behavior is modified with a pozzolanic addition, silica fume. Therefore, two types of concrete were designed, a conventional and a recycled concrete, both made with 8% of silica fume. In conclusion, a reduction of shear friction capacity was observed in recycled concretes, considerably higher in the case of the specimen without reinforcement. The addition of silica fume improved the behavior of recycled concretes. The results obtained were compared with the formulations of the different authors. In all cases, these were found to be conservative. However, the safety margins offered by recycled concretes are lower than those obtained with conventional concretes.En esta investigación se estudió el comportamiento de los hormigones reciclados frente al fenómeno de transmisión de cortante. Para ello se diseñó un hormigón convencional de control y un hormigón con el 50% del árido grueso reciclado. Adicionalmente, para determinar cómo este comportamiento se ve modificado con la incorporación de una adición puzolánica (humo de sílice), se procedió al diseño de un hormigón convencional y su correspondiente reciclado con un 8% de humo de sílice. Los resultados indicaron una disminución de la capacidad frente a este fenómeno en los hormigones reciclados, más acusada en ausencia de armadura pasante. La adición de humo de sílice mejora el comportamiento de este material. Los resultados experimentales obtenidos se compararon con formulaciones teóricas de diversos autores, concluyéndose que éstas son, en todos los casos, conservadoras, aunque reducen el margen de seguridad en los hormigones reciclados

Estudio de la calidad del árido reciclado y su relación con la resistencia a compresión del hormigón reciclado utilizando una base de datos

This work studies the physical and mechanical properties of recycled concrete aggregate (recycled aggregate from concrete waste) and their influence in structural recycled concrete compressive strength. For said purpose, a database has been developed with the experimental results of 152 works selected from over 250 international references. The processed database results indicate that the most sensitive properties of recycled aggregate quality are density and absorption. Moreover, the study analyses how the recycled aggregate (both percentage and quality) and the mixing procedure (pre-soaking or adding extra water) influence the recycled concrete strength of different categories (high or low water to cement ratios). When recycled aggregate absorption is low (under 5%), pre-soaking or adding extra water to avoid loss in workability will negatively affect concrete strength (due to the bleeding effect), whereas with high water absorption this does not occur and both of the aforementioned correcting methods can be accurately employed.El estudio analiza las propiedades físico-mecánicas de los áridos reciclados de hormigón (procedentes de residuos de hormigón) y su influencia en la resistencia a compresión del hormigón reciclado estructural. Para ello se ha desarrollado una base de datos con resultados de 152 trabajos seleccionados a partir de más de 250 referencias internacionales. Los resultados del tratamiento de la base indican que densidad y absorción son las propiedades más sensibles a la calidad del árido reciclado. Además, este estudio analiza cómo el árido reciclado (porcentaje y calidad) y el procedimiento de mezcla (presaturación o adición de agua extra) influyen en la resistencia del hormigón reciclado de diferentes categorías (alta o baja relación agua-cemento). Cuando la absorción es baja (inferior al 5%) presaturar o añadir agua para evitar pérdidas de trabajabilidad afectan negativamente a la resistencia (debido al bleeding), mientras que cuando es alta esto no sucede y ambos métodos son adecuados

Efecto del drenaje ácido sobre el fraccionamiento de tierras raras ligeras en sedimentos: un caso de estudio en el estuario de los ríos Tinto y Odiel

The effect of acid drainage on light rare earth elements (LREE) has been studied in the estuarine sediment of the Tinto and Odiel system, where the fluvial and marine water mixing cause an important pH and chlorinity gradient inside. Due to the high influence of pH over the LREE partitioning from dissolved toparticulate phases, an anomalous behaviour has been found on La content in these sediments. Large removal of LREE takes place at low chlorinity zones in unaffected estuaries, but in the studied system this natural process is moved out the outer zones of the estuary. So, the relative La depletion in the estuarine mixing zone is due to the low pH values (< 6) that prevents LREE removal in low chlorinity zones. Once the acid neutralization (pH ~ 7) occurs, some La enrichment can be observed in sediments of the marine estuary.Versión de edito

Variaciones estacionales de tierras raras en la materia en suspensión y el agua del estuario del río Odiel (SO de España)

Seasonally distribution of the lanthanides in the suspended matter and dissolved phasehas been studied during a hydrological year in the estuary of the Odiel River. In his system affected by acid mine drainage take place the coexistence of two water mixture processes; a process salt-induced mixture typical in an estuary and a process of acid water neutralization. In the mixing zone of the estuary there is a removal of the dissolved phase to the suspended matter out of the system. REEs concentrations are controlled by the volume of discharge of the river and degree of neutralization process. Thus, during first rains after a dry period, the gradient in concentration of these elements in the mixing zone ismore pronounced in this system.Versión de edito

Economic evaluation of endoscopic radiofrequency ablation for the treatment of dysplastic Barrett's esophagus in Spain

Background and study aims: To assess the cost-effectiveness of introducing endoscopic treatment based on radiofrequency ablation plus endoscopic mucosal resection in selected patients into the standard of care of Barrett's esophagus patients with high-grade dysplasia or low-grade dysplasia in Spain. Methods: The disease evolution was modeled via a semi-Markov model. The treatment strategies compared included endoscopic treatment based on radiofrequency ablation plus endoscopic mucosal resection and the Standard of Care (esophagectomy or palliative chemoradiotherapy according to disease status for high-grade dysplasia and endoscopic surveillance for low-grade dysplasia). Efficacy rates, transition probabilities and utility values were obtained from the literature. Clinical management patterns and resource use were modeled according to Spanish clinical expert opinion. Costs were expressed in euros ((sic)) from 2016 reflecting the Spanish National Health System perspective. Sensitivity analyses were performed to assess the robustness of the model. Results: With respect to the Spanish Standard of Care, endoscopic treatment based on radiofrequency ablation plus endoscopic mucosal resection was a dominant strategy for high-grade dysplasia patients. When a willingness-to-pay threshold of (sic)30,000 per quality-adjusted life-years gained was considered, this was cost-effective for low-grade dysplasia patients ((sic)12,865 per quality-adjusted life-years gained). The sensitivity analyses supported the base case analysis results and pointed towards the main drivers of uncertainty in the model. Conclusions: From a health care decision-maker, endoscopic treatment based on radiofrequency ablation plus endo-scopic mucosal resection is the intervention of choice for dysplasic Barrett's esophagus patients in Spain

Edta como extractante universal : I- cationes mayores (Ca, Mg y K)

p.133-137Se escogieron 15 muestras de suelos de diferentes lugares del país procediéndose a la extracción de cationes mayores con solución 0,1 M de EDTA pH 7,0. Paralelamente las mismas muestras se trataron con solución de acetato de amonio pH 7,0, determinándose en ambas soluciones calcio, magnesio y potasio por espectro fotometría de absorción atómica. Los resultados analíticos indican una estrecha correlación para calcio, magnesio y potasio obtenidos con los dos extractantes

Evaluación del comportamiento térmico de una edificación reemplazando el material de la envolvente por suelo-cemento

Los cerramientos de una edificación responden lentamente a cambios en la temperatura exterior produciendo variaciones graduales de la temperatura ambiente del interior afectando el nivel de confort de los ocupantes. Debido a ello, resulta necesario acondicionar la temperatura interior al rango de confort para lo cual se requiere del consumo de energía. En este estudio se evalúan las mejoras en la eficiencia energética de una edificación reemplazando el material de la envolvente por mampuestos de suelo cemento. Se realizan registros de temperatura y humedad en el ambiente y se efectúa un estudio energético. Las propiedades térmicas de los mampuestos son estudiadas en laboratorio generando los parámetros necesarios para modelar el flujo de calor a través de la envolvente. Los análisis se realizan a partir de balances térmicos del edificio, primero se evalúa el cerramiento original y luego el alternativo con mampuestos de suelo-cemento. Los resultados obtenidos permitieron cuantificar el ahorro energético que podría lograrse por la sustitución de la envolvente y demostrar, al mismo tiempo, que los mampuestos de suelo-cemento mejoran las condiciones de confort térmico de las edificaciones.Temperature of walls in building slowly change as a response of outside temperature changes. As a consequence of this temperature variation, the inner temperature of a building slowly changes affecting the comfort level of the occupants. Therefore, there is a need of modifying the inner temperature to reach values within the comfort range. This study evaluates the influence of changing conventional wall materials by soil-cement bricks on the energy efficiency in a building. Temperature and humidity measurements were performed inside and outside the building in order to perform a thermal balance. The thermal properties of the bricks were determined in laboratory. These results were used to model the heat flow through the external walls of the building. The thermal balance of the building was determined for walls made of conventional and soil-cement bricks. Obtained results allowed us to quantify the energy savings that could be achieved by replacing conventional by soilcement brick walls. Finally, the use of soil-cement bricks in external walls of buildings helps to improve the thermal comfort conditions.Tema 5: Arquitectura ambientalmente consciente.Facultad de Arquitectura y Urbanism

Mineralización del fósforo orgánico

p.157-163Con la finalidad de estudiar el índice de mineralización del fósforo se efectuaron incubaciones de suelos naturales y previamente esterilizados, solos y en contacto con resina Amberlite IRA 400 en su forma C 0 3 H - y Cl- llevada a pH 7,0. Las variaciones del fósforo inorgánico se estudiaron en períodos entre 1 y 56 días