En este estudio, se exploró la fotosensibilización del semiconductor TiO2, mediante un colorante comercial, con el objeto de aumentar sus propiedades catalíticas. Se evaluaron los siguientes parámetros: la concentración de colorante, el tiempo de sensibilización del semiconductor, la cantidad de moles de colorante adsorbidas sobre el semiconductor y el corrimiento de la absorción de la radiación del catalizador modificado hacia la región del espectro visible. Finalmente, se realizaron pruebas de la actividad fotocatalítica del catalizador modificado en la degradación del contaminante modelo (fenol). Se obtuvo una eficiencia de remoción de 33,85% de la concentración inicial de fenol, comparada contra 18,98% usando TiO2 sin modificar. La fotosensibilización del TiO2 con colorantes comerciales aparece como una alternativa técnica y económicamente viable, para incrementar las propiedades fotocatalíticas del TiO2. | In this study, the photosensitization of TiO2 semiconductor with a commercial dye in order to increase its catalytic properties was explored. The following parameters were evaluated: the dye concentration used on the sensitization, the semiconductor sensitization time, the amount (unit: mol) of the dye, adsorbed on the semiconductor and the radiation absorption shift on the modified catalyst towards the visible spectrum region. Finally, the photocatalytic activity of the modified catalyst through the degradation of a pollutant model (phenol) was tested. A removal efficiency of 33.85 per cent of the initial concentration of phenol, compared to 18.98 per cent using unmodified TiO2 was obtained. Photosensitization of TiO2 with commercial dyes appears to be a technically and economically feasible alternative, which can be adopted as an option to increase the photocatalytic properties of TiO2.

El estado de Oaxaca, México, tiene zonas productoras de 'chile de agua' (Capsicum annuum L.) que se diferencian por sus características fisiográficas y agroecológicas. Con el objetivo de generar conocimiento que contribuya a la conservación y mejoramiento genético del potencial productivo de esta especie, en ocho zonas se colectó germoplasma y caracterizó in situ durante 2006 y 2007 bajo un esquema de muestreo completamente aleatorio, con dos localidades por zona y diez plantas por localidad, para lo cual se empleó la guía del Instituto Internacional de Recursos Fitogenéticos. Durante 2008, para disminuir el efecto ambiental, se llevó a cabo una caracterización morfológica ex situ en condiciones de invernadero; para ello las ocho colectas (360 plantas) fueron cultivadas bajo un sistema intensivo en hidroponía, en un diseño experimental completamente al azar; la información se obtuvo de ocho muestreos efectuados cada quince días, en los cuales se identificaron descriptores de raíz, tallo, flor, fruto y semilla, que permitieron diferenciar (selección de variables) las colectas e identificarlas en tres grupos (análisis de agrupamiento de mínima varianza de Ward) y describir las características responsables de la agrupación (análisis de componentes principales). El germoplasma de la zona de Ocotlán, Oaxaca, resultó promisorio para un proceso de mejoramiento genético por presentar los frutos con los caracteres más deseables para el mercado. | Oaxaca state of Mexico has a number of zones with 'water chilli' pepper, (Capsicum annuum L.) which differ in their physiographic and agro-ecological characteristics. With the objective of to generate knowledge that contributes to the conservation and genetic improvement of the productive potential of this species of chilli, in eight zones, germplasm was collected and characterized in situ during 2006 and 2007 under a completely random sampling using two locations and ten plants per location, which used the guide to the International Plant Genetic Resources Institute. To decrease the environmental effect of the collection sites, was carried out ex situ morphological characterization, during 2008, under greenhouse conditions, therefore the eight collections (360 plants) were grown under an intensive system in hydroponics, in a design completely randomized. The information was extracted from eight samples taken every fifteen days. From analysis of variance and covariance were identified descriptors root, stem, flower, fruit and seed, to distinguish collections. In the cluster analysis of cluster (Ward minimum variance) and describe the characteristics of the grouping responsible (principal components analysis) were identified three groups and Ocotlán germplasm as promising for a process of genetic improvement by to present the fruits with the characteristics most desirable for the market.

11 diapositivas.-- Publicado como capitulo del libro: Avances de la Geomorfología en España, 2008-2010: 131-134 (2010); ISBN: 978-84-693-4; Ed: Sociedad Española de Geomorfología. | Peer reviewed

Initial soil conditions, operational aspects, and tool shape affect the efficiency of soil decompaction. The objective of this study was to evaluate the performance of a winged scarifier as a function of soil compaction and edaphic water content. The experiment was carried out in a typical Hapludoll. Treatments considered two soil compaction levels: high (HC) and low compaction (LC); and three soil water contents: wet (WS), humid (HS), and dry (DS) with 9, 14, and 19% gravimetric water content, respectively. A split-plot randomized block design was applied. Tractive effort, disturbed area, tillage depth, specific resistance, and power were evaluated. Results showed that tractive effort was 17% greater in HC than LC, and in both cases HS was greater than WS and DS. The specific resistance in HC was equal to 8, 9, and 11 N cm-2 in WS, HS, and DS, respectively, and 7, 8, and 7 N cm-2 in BC in similar soil water contents, respectively. Tillage depth was low and irregular only in HC-DS. Specific resistance was not an adequate indicator of overall work efficiency because it does not consider the final soil physical profile. Overall work efficiency in HC was greater under HS conditions, while in LC it was greater under HS and DS conditions. | Facultad de Ciencias Agrarias y Forestales

El suelo radiante es un equipamiento presente en invernaderos comerciales y utilizado convencionalmente como método de calefacción. En este trabajo, en cambio, se ha realizado una evaluación experimental de la refrigeración de un invernadero mediante el uso del suelo radiante acoplado a una bomba de calor aire-agua. Se ensayaron dos escenarios durante los veranos de 2005 y 2006: ventilación natural + malla de sombreo (escenario control), y ventilación natural + malla de sombreo + suelo radiante acoplado a una bomba de calor (escenario de refrigeración activa). Se calcularon las diferencias entre la temperatura del aire interior y exterior (salto térmico), y se concluyó que a 0,5 m sobre el suelo, el sistema suelo radiante-bomba de calor redujo esta diferencia 1,1 grados C en 2005 y 0,8 grados C en 2006. Ambos escenarios se compararon con el comportamiento de otros sistemas de refrigeración: se concluyó que el escenario de refrigeración activa obtenía un salto térmico (medido a 0,5 m) más favorable incluso que la nebulización. Se diseñó un modelo basado en las curvas de rendimiento de la bomba de calor para predecir la capacidad refrigerante desarrollada por el sistema suelo radiante-bomba de calor. El consumo energético de la bomba de calor fue 104,8 Wh/m cuadrado/d (de 13:00 a 18:00 h) bajo las condiciones de ensayo. Este sistema parece ser apropiado sólo para refrigerar invernaderos bajo ciertas condiciones, para cultivos de alto valor añadido, cultivos de bajo porte, o cuando el coste de inversión no es un factor limitante ya que éste es aproximadamente 38 Euros/m cuadrado. | This paper describes the experimental cooling of a greenhouse in Madrid (Spain) using a radiant heated floor (RHF) coupled to an air-water heat pump (HP). Two cooling scenarios were studied over the summers of 2005 and 2006: natural ventilation + a shading screen (control system), and natural ventilation + a shading screen + an RHF (concrete) coupled to an air-water heat pump (i.e., in cooling mode; nominal power, 34.1 W/squre m). Using the difference between the outside and inside air temperatures, it was concluded that at 0.5 m above the floor the RHF system reduced the temperature by 1.1 deg C in 2005 and 0.8 deg C in 2006. Both cooling scenarios were compared with other cooling technologies: the use of the natural ventilation + shading + RHF gave a smaller air temperature difference than fogging at a height equal to or lower than 0.5 m. A model based on the heat pump performance curves was constructed to predict its power consumption and good predictions of the variation over the day were obtained. The power consumption of the heat pump was 104.8 Wh/square m/d (from 13:00 to 18:00 h) under our test conditions in Madrid. The RHF-HP system may only be appropriate for cooling greenhouses under certain circumstances, e.g., when growing high value crops or when cost is not a limiting factor, as its initial investment cost is about Euros 38/m.

Para avaliar o efeito da cloração orgânica na uniformidade de distribuição de água e na vazão de um tubogotejador com vazão de 2,2 L h-1, foram testados quatro níveis de concentrações de dicloroisocianurato de sódio (N1 = 0, N2 = 15, N3 = 30 e N4 =45 mg L-1 de cloro livre). As avaliações foram realizadas no início do experimento e a cada 100 horas de funcionamento do sistema, totalizando 8 avaliações. No cálculo da uniformidade de aplicação de água foram utilizados os coeficientes de uniformidade deChristiansen (CUC), de distribuição (CUD) e de emissão (Us). Também se realizou o estudo da vazão e do coeficiente de variação da vazão (CVq). Verificou-se que no nível N1 ocorreram reduções de 23; 30,2 e 8,35%, para o CUC, CUD e Us, respectivamente, sendo que a vazão apresentou uma redução de 6,13%, refletindo em um aumento do CVq. Otratamento com dicloro foi eficiente para precaver contra entupimento para todas as concentrações utilizadas e o sistema foi classificado com excelente uniformidade em praticamente todas as avaliações.<br><br>To evaluate the effect of the organic chlorination in the uniformity of water distribution and in the outflow of a tubedripper with 2,2 L h-1, had been tested four levels of concentrations of dicloroisocianurato of sodium (N1 = 0, N2 = 15, N3 = 30 e N4 = 45 mg L-1 of free chlorine). The evaluations had been carried through in the beginning of the experiment and to each 100 hours of functioning of the system, totalizing 8 evaluations. In the calculation ofthe uniformity of water application had been used the coefficients of uniformity of Christiansen (CUC), of distribution (CUD) and emission (Us). Also the study of the discharge and the coefficient of variation of the discharge (CVq). It was verified that in thelevel N1, reductions of 23; 30.2 and 8.35%, for the CUC, CUD and US, respectively. The discharge presented a 6.13% reduction, reflecting in an increase of the CVq. The treatment with dicloro was efficient to prevent against clogging for all the used concentrations and thesystem was classified with excellent uniformity in practically all the evaluations.

O objetivo deste trabalho foi avaliar e monitorar a qualidade da água para fins de irrigação no distrito de Irrigação Platôs de Guadalupe, no período chuvoso e seco, no município de Guadalupe, Estado do Piauí. No Perímetro foram georreferenciados vinte e um pontos onde foram realizadas análises in-situ utilizando-se uma sonda portátil multiparâmetros (YSI série - 6), e posteriormente coletadas nos mesmos pontos amostras de água para analise em laboratório.