17 research outputs found

    Inducible expression of Pisum sativum xyloglucan fucosyltransferase in the pea root cap meristem, and effects of antisense mRNA expression on root cap cell wall structural integrity

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    Mitosis and cell wall synthesis in the legume root cap meristem can be induced and synchronized by the nondestructive removal of border cells from the cap periphery. Newly synthesized cells can be examined microscopically as they differentiate progressively during cap development, and ultimately detach as a new population of border cells. This system was used to demonstrate that Pisum sativum L. fucosyl transferase (PsFut1) mRNA expression is strongly expressed in root meristematic tissues, and is induced >2-fold during a 5-h period when mitosis in the root cap meristem is increased. Expression of PsFut1 antisense mRNA in pea hairy roots under the control of the CaMV35S promoter, which exhibits meristem localized expression in pea root caps, resulted in a 50–60% reduction in meristem localized endogenous PsFut1 mRNA expression measured using whole mount in situ hybridization. Changes in gross levels of cell wall fucosylated xyloglucan were not detected, but altered surface localization patterns were detected using whole mount immunolocalization with CCRC-M1, an antibody that recognizes fucosylated xyloglucan. Emerging hairy roots expressing antisense PsFut1 mRNA appeared normal macroscopically but scanning electron microscopy of tissues with altered CCRC-M1 localization patterns revealed wrinkled, collapsed cell surfaces. As individual border cells separated from the cap periphery, cell death occurred in correlation with extrusion of cellular contents through breaks in the wall

    The effects of moisture content, particle size and binding agent content on oil palm shell pellet quality parameters

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    Waste-to-energy represents a challenge for the oil palm industry worldwide. Bio-pellet production is an alternative way of adding value to oil palm biomass. This would mean that a product having major energy density becomes more mechanically stable and achieves better performance during combustion. This paper deals with oil palm shell pelleting; using binding agents having up to 25% mass keeping average particle size less than 1mm and moisture content up to 18.7% (d.b.) were evaluated. An experimental factorial design used binding agent mass percentage, milled shell particle size and moisture content as factors. Pellet density response surfaces and durability index were obtained. Pellet performance during thermal-chemical transformation was also evaluated by using thermogravimetry equipment. The results led to technical evaluation of scale-up at industrial production level.El uso de residuos en la producción de energía es un reto para la industria de la palma de aceite en todo el mundo. La producción de biopellets es una alternativa para agregar valor a la biomasa residual de la palma de aceite. Mediante el proceso de densificación de la biomasa se obtiene un producto con mayor densidad energética, mayor estabilidad mecánica y mejor desempeño durante el proceso de combustión. En este artículo se presenta un estudio sobre el proceso de peletizado del cuesco de palma de aceite. En los experimentos se emplea una biomasa residual a la cual se le adiciona agente aglutinante hasta el 25% en masa, manteniendo el tamaño promedio de partícula por debajo de 1 mm y el contenido de humedad hasta el 18,7% (b.s.). Se lleva a cabo un diseño factorial experimental que emplea como factores experimentales el contenido de agente aglutinante, tamaño de partícula del cuesco molido y el contenido de humedad. Como resultado se muestran las superficies de respuesta para la densidad y el índice de durabilidad de los pellets. También, se estudia el desempeño de los pellets durante la transformación termoquímica por medio de un ensayo de termogravimetría. Los resultados obtenidos en este estudio permiten la evaluación técnica del proceso de fabricación de pellets del cuesco de palma de aceite a escala de producción industrial

    Multidisciplinary design optimisation techniques

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    Design optimisation of a multidisciplinary prolect in engineering involves the decomposition of a system into disciplines and the subsequent association of their contributions. This work was aimed at presenting the most common decomposition and association techniques currently used in multidisciplinary design optimisation (MDO). Amongst the decomposition techniques this work includes hierarchical and non-hierarchical approaches as well as the most popular numerical procedures. The association techniques include: one-level methods (e.g. all-at-once optimisation and simultaneous analysis and design), multilevel methods (e.g. concurrent subspace optimisation and collaborative optimisation) and robust design. This work also incorporates an illustrative numerical example

    Técnicas de diseño óptimo multidisciplinario

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    El proceso de optimización de un proyecto multidisciplinario en ingeniería involucra la descomposición de un sistema en distintas disciplinas y la posterior asociación de sus contribuciones. El objetivo de este trabajo es presentar los esquemas de desagregación y asociación más utilizados actualmente en procesos de diseño óptimo multidisciplinario — Multidisciplinary Design Optimization (MDO). Entre los esquemas de desagregación se presentan la descomposición jerárquica y no jerárquica, así como los métodos computacionales más comunes. Los esquemas de asociación incluyen: formulación de un solo nivel (e.g., optimización integrada y análisis y diseño simultáneos), formulación de múltiples niveles (e.g., optimización en espacios concurrentes y optimización colaborativa) y diseño robusto. El trabajo presenta también un ejemplo de aplicación resuelto numéricamente.Design optimisation of a multidisciplinary prolect in engineering involves the decomposition of a system into disciplines and the subsequent association of their contributions. This work was aimed at presenting the most common decomposition and association techniques currently used in multidisciplinary design optimisation (MDO). Amongst the decomposition techniques this work includes hierarchical and non-hierarchical approaches as well as the most popular numerical procedures. The association techniques include: one-level methods (e.g. all-at-once optimisation and simultaneous analysis and design), multilevel methods (e.g. concurrent subspace optimisation and collaborative optimisation) and robust design. This work also incorporates an illustrative numerical example
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