Examinando por Materia "Biomass"

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    PublicaciónAcceso abierto
    Biomass production of Scenedesmus sp. and removal of nitrogen and phosphorus in domestic wastewater
    (Universidad del Valle, 2017-01-30) Acevedo, Stephanie; Peñuela, Gustavo A.; Pino, Nancy J.
    (Eng) Domestic wastewater (DW) has been used as a substrate for both microalgae biomass production and nutrient removal. Biological treatment with photosynthetic microalgae provides aeration, reducing operating costs and the risk of volatilization of contaminants. It also provides oxygen to the bacteria for degradation of organic compounds. In this study, a microalga was isolated and identified as Scenedesmus sp. An experimental trial was performed using synthetic wastewater with different concentrations of N (40, 90 and 150 mg/L) and P (4, 15 and 50 mg/L). Each assay was inoculated with 1x106 cells/ml under 16h of continuous light at 50-µmol m-2 s-1 at and 120 rpm for 7 days. Samples were taken at 0, 3, 5 and 7 days to determine the growth of microalgae and the concentration of nitrates, ammonium and phosphorus. The same treatment was carried out using real DW. Synthetic water of low and medium concentration had higher removal percentages. These were between 50 and 60 for nitrogen and 40 and 70 for phosphorus, with a maximum growth of 1x107 cells /ml. For real DW, the removal was 65% for phosphorus and 80% for nitrogen. These results suggest Scenedesmus sp could be used to treat DW, enhancing nutrient removal and obtaining biomass for other purposes.
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    PublicaciónAcceso abierto
    Hypothenemus hampei (Coleoptera: Curculionidae) as in vitro inducer of laminarinase and chitinase of Beauveria bassiana (Hypocreales: Clavicipitaceae).
    (Universidad del Valle, 2017-06-30) Acuña Payano, Rosalyn; Quiroz Farfán, Diego; Laynes Zela, Pedro; Nolasco Cárdenas, Oscar; Gutiérrez Román, Ana; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle
    In Peru, Hypothenemus hampei or the coffee berry borer, (CBB) is the most important pest, causing specific damage to coffee crops, because it causes fruit to fall during feeding. On the other hand, Beauveria bassiana is an entomopathogenic fungus widely used in biological control. This study determine the induction of chitinase and laminarinase of B. bassiana in presence of H. hampei powder and how it relates to pathogenicity in order to promote the development of biological control agents and replace the use of pesticides. Three different liquid media cultures were prepared to induce the enzymatic production and growth of B. bassiana; and biomass, total proteins, conidia, enzymatic activities and enzymatic specific activities were evaluated. Data were analyzed using SPSS 19.0. Significant differences (P < 0.05) for biomass (F = 5.30; df = 35; P < 0.05), conidia (F = 190.87; df = 35; P < 0.05), total proteins (F = 91.04; df = 35; p < 0.05), laminarinase activity (F = 27.61; df = 35; P < 0.05), specific laminarinase activity (F = 25.31; df = 35; P < 0.05), chitinase activity (F = 32.66; df = 35; P < 0.05) and specific chitinase activity (F = 26.91; df = 35; P < 0.05) were determined between each treatment evaluated. Levels of chitinase and laminarinase determined that induction of these enzymes is possible in liquid media cultures supplemented with powdered H. hampei extract. Results require further evaluation for application in vivo but are fundamental and constitute a contribution to knowledge about the pathogenic mechanism of B. bassiana.
  • Miniatura
    PublicaciónAcceso abierto
    Principales Rutas en la Producción de Hidrógeno.
    (Universidad del Valle, 2021-05-18) Brijaldo, Maria H.; Castillo, Cristian; Pérez, Gerónimo
    Las características físicas y químicas del hidrógeno lo han convertido en un vector energético prometedor con grandes aplicaciones en celdas de combustibles, así como materia prima para la participación en diversos procesos químicos a nivel de industrial. Una de las fuentes renovables de energía utilizada para la obtención de hidrógeno es la biomasa. Se han empleado varias moléculas modelo de biomasa para la generación de hidrógeno, las cuales incluyen principalmente alcoholes, carbohidratos, ácidos carboxílicos, alcanos entre otras. Estas moléculas son transformadas mediante rutas termoquímicas, bioquímicas, fotoquímicas, electroquímicas, catalíticas, etc., con el objetivo de alcanzar el mayor rendimiento a hidrógeno. En cada una de ellas, numerosas condiciones de reacción son utilizadas, sustratos y catalizadores son empleados. En esta revisión se abordarán algunos de los tópicos anteriormente mencionados y se vislumbraran algunas prospectivas y futuras investigaciones que pueden llevarse a acabo en el campo de la generación de hidrógeno.
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    PublicaciónAcceso abierto
    Los sensores remotos en los proyectos de mitigación de gases de efecto invernadero.
    (2015-04-10) Zapata Arbeláez, Beatriz Irene; Anaya Acevedo, Jesús Adolfo
    Se realizó una revisión del estado del arte de las técnicas de teledetección para la implementación de programas de mitigación de Gases de Efecto Invernadero (GEI), MDL y REDD. Para tal fin se recopiló la información documentada haciendo una clasificación de la misma en tres grandes clases de sensores: ópticos, radar y LiDAR. Posteriormente, se evaluó la conveniencia del uso de cada uno de estos en los diferentes elementos que contiene el monitoreo de REDD en áreas tropicales, resaltando la gran importancia que tienen las observaciones de campo y el conocimiento de las áreas evaluadas para la escogencia de la escala y para los supuestos que se realicen en la tipificación de la dinámica del bosque. Por último, se presentan las características principales de los tipos de sensores, así como sus limitaciones y cómo estas limitaciones se pueden disminuir al combinar diferentes técnicas metodológicas. ABSTRACT. A state of the art of remote sensing techniques was made in the context of Greenhouse Gases (GHG) emissions, CDM and REDD. For this purpose the documented information was collected and classified into three major classes of sensors: optical, radar and LiDAR. In addition, we evaluated the appropriateness of each sensor in the monitoring of the REDD tropical forests. Here, we highlighted the added value of field observation, the great value of local knowledge in areas to be evaluated, the selection of the appropriate detail level (scale), and the importance of characterizing forest dynamics. Finally this article presents the main characteristics of sensor types, sensor limitations and how these can be reduced by combining different techniques.