Dissertations / Theses on the topic 'Sugar concentration'

Among the platform chemicals that can be produced from lignocellulosic biomass, furfural (FUR) constitutes a promising intermediate that can be processed into a variety of advanced end products. In this thesis, the catalytic dehydration of C5-sugars was first developed and optimized using aqueous xylose solutions before the prehydrolysate of birch wood was used as a real substrate. Initially, the use of various metal oxides, such as sulphated zirconium dioxide (SZ) on cordierite and aluminum oxide on cordierite, as catalysts for the conversion of xylose to FUR was investigated and optimized, as they were considered relatively stable under hydrothermal conditions and also exhibit a relatively high proton activity. The maximum FUR yields from xylose were 41 mol% when using SZ on cordierite after 2 min at 210 °C, 43 mol% when using alumina on cordierite for 30 min at 210 °C and 48 mol% using autocatalysis for 60 min at 210 °C. After five reusability cycles with SZ on cordierite, this catalyst can be regenerated with similar performance and FUR yield in the 6th cycle. In addition to heterogeneously catalyzed xylose dehydration into FUR in a monophasic, aqueous system, FUR formation in a biphasic system under auto-catalyzed conditions was also investigated. With water-immiscible organic solvents such as isophorone, cyclopentyl methyl ether (CPME), 2-methyltetrahydrofuran and 2-sec-butylphenol (SBP) FUR was immediately extracted from the aqueous phase to avoid degradation as far as possible. The maximum FUR yields reached from xylose were 48 mol% when using isophorone, 78 mol% when using CPME and 59% when employing SBP. The use of birch prehydrolysate as a source of C5-sugars led to a yield of 68% furfural and 0.01 mmol of 5-hydroxymethylfurfural at 190 °C when using CPME. When using SBP as organic solvent, a furfural yield of 54% was reached at 190 °C under optimized conditions. In the second phase of the dissertation, Starbon®, a carbonaceous sulfonated acid catalyst, was used in a two-phase system to produce furfural from xylose. A maximum furfural yield and selectivity of 70 mol% was achieved at complete xylose conversion under optimum experimental conditions. This work suggests that functionalized Starbon® can be used as solid acid catalyst for the conversion of C5-sugars into FUR that has significant hydrothermal stability and can be reused for several cycles. Finally, a techno-economic analysis was completed for a furfural plant with a production capacity of 5 kt/a with a minimum selling price to be 1.33 EUR/kg. This value is comparable to similar studies in the field.
La biomasa lignocelulósica representa un sustituto renovable de los materiales fósiles para la producción de combustibles y otros productos químicos. Las hemicelulosas en la biomasa lignocelulósica representan una materia prima atractiva para la producción de plataformas versátiles para un amplio rango de aplicaciones. Debido a su alto contenido en xilosa y su bajo contenido en lignina y otros carbohidratos que son productos de la degradación, el prehidrolizado de la madera es la fuente más prometedora de pentosas. En el proceso Kraft, el prehidrolizado genera durante la producción de pulpa para disolver. En la actualidad, los volúmenes de pulpa para tratar aumentan en promedio más de 5% cada año, y el prehidrolizado se considera una fuente sostenible de pentosas. Entre los productos químicos que pueden ser producidos a partir de estos materiales de origen biológico, el furfural (FUR) constituye un producto de interés que puede ser transformado en una gran variedad de productos finales avanzados. En esta tesis doctoral, la deshidratación catalítica de pentosas se desarrolló y optimizó utilizando disoluciones acuosas de xilosa antes que el prehidrolizado de madera de abedul fuera utilizado corno sustrato real. Inicialmente, se utilizaron varios óxidos metálicos, corno dióxido de zirconio sulfatado (SZ) sobre cordierita y óxido de aluminio sobre cordierita, como catalizadores para la conversión de xilosa a FUR, los cuales fueron relativamente estables bajo condiciones hidroterrnales. Las producciones de FUR a partir de xilosa fueron 41 mol% cuando se utilizó SZ sobre cordierita después de 2 rnin a 21 O ºC y 43 mol% cuando se utilizó alurnina sobre cordierita por 30 rnin a 21 O ºC, mientras que el sistema autocatalizado produjo 48 mol% después de 60 rnin a 21 O ºC. El catalizador SZ sobre cordierita puede ser regenerado con rendimiento y producción de FUR similares. Adicionalmente a la deshidratación catalítica heterogénea de xilosa a FUR en un sistema monofásico acuoso, la formación de FUR en un sistema bifásico bajo condiciones autocatalizadas también fue investigado. Con la adición de disolventes inmiscibles en agua como isoforona, ciclopentll metil eter (CPME), 2-metiltetrahidrofurano (2-MTHF) y 2-sec-butilfenol (SBP), el FUR extrae desde la fase acuosa y así se evita su degradación. La producción máxima de FUR alcanzada de xilosa fue 48 mol% cuando se utilizó isoforona, 78 mol% cuando se utilizó CPME y 59% con SBP. El uso de prehidrolizado de abedul como fuente de pentosas condujo a una producción de 68% de FUR y 0.01 mmol de 5- hidroximetilfurfural a 190 ºC cuando se empleó CPME. Cuando se utilizó SBP como disolvente orgánico, se alcanzó una producción de furfural del 54% a 190 ºC. En la segunda parte de esta tésis doctoral, se utilizó Starbon®, un catalizador ácido sulfonado de naturaleza carbonosa, en un sistema bifásico para producir furfural a partir de xilosa. Se alcanzó una producción máxima de furfural y una selectividad de 70 mol% con una conversión completa de xilosa. Se concluye, por tanto, que el Starbon® funcionalizado puede ser utilizado corno catalizador ácido sólido para la conversión de pentosas a furfural puesto que, además, tiene una estabilidad hidrotermal elevada y puede ser reutilizado por varios ciclos.

Wheat straw is available in western Canada and it is a potential feedstock for bio-ethanol production as it can be effectively fractionated into simple sugars using acid catalyzed, steam pretreatment followed by enzymatic hydrolysis. Steam pretreatment is usually a compromise whereby conditions that facilitate effective enzymatic hydrolysis at low enzyme loadings usually sacrifice the recovery of the hemicellulose component. Previous work that tried to optimize the pretreatment to maximize hemicellulose recovery was usually done at the expense of using unacceptably high enzyme loadings to hydrolyze the cellulosic fraction. The goal in this thesis was to determine the highest possible amount of sugar that could be solubilized after both pretreatment and enzymatic hydrolysis while using low enzyme loadings and high solids concentration. It was anticipated that the optimum conditions for maximizing the total soluble sugar yield would still result in the degradation of a portion of the hemicellulose. The biomass handling conditions were first investigated to identify the best possible conditions to maximize sugar recovery. An optimized moisture content combined with the explosive decompression resulted in the highest xylose recovery. It was also found that H₂SO₄ could be used at a loading of 1.5% w/w to produce a substrate with similar chemical composition, sugar recovery and ease of enzymatic hydrolysis to what was obtained when using 3% SO₂ as the catalyst. The pretreatment conditions were then varied to determine the effect of pretreatment severity on the recovery of total soluble sugars. The highest soluble sugar yield of 75% was obtained after pretreatment at 190°C, 8 min and 1.5% H₂SO₄. This is among the highest sugar yields that have been reported and comparable to those reported when using a three-fold higher enzyme loading. However, at these conditions only 52% of the original xylan was recovered. A less severely treated substrate with 70% xylan recovery achieved a total soluble sugar yield of 72% when the “cellulase mixture” was supplemented with xylanases. Thus, pretreatments at lower severities followed by enzymatic hydrolysis using a “cellulase mixture” with xylanase supplementation may be an effective approach to improve the total soluble sugar yield when processing wheat straw.

Tomato is an important commodity in fresh vegetable market. Recently, there is great interest for North American hydroponic growers to improve the fruit quality by introducing better cultivation methods. Manipulation of electrical conductivity (EC) of nutrient solution is a well-known technique to increase sugar concentrations of tomato; however, the potential risk of lower yield is the drawback of introducing this technique. Therefore to find a range of EC that can enhance the fruit quality while maintaining overall yield was the goal of this research. For this purpose, plant physiological responses such as transpirational and photosynthetic characteristics and fruit quality attributes including sugars and lycopene were investigated for selected cultivars under different EC. Regardless of cultivar, tomato plants showed a greater net photosynthetic rate at the reproductive growth stage compared to the vegetative growth stage. An increase of EC of influx nutrient solution up to 4.8 dS m-1 did not reduce the leaf photosynthesis, which supported a hypothesis that there is an optimum EC range for enhancing fruit quality without significant yield loss. A following experiment showed that the tomato fruit quality could be significantly enhanced when plants were grown under around 4.5 dS m-1 EC, in terms of total soluble solids (TSS) and lycopene concentration with no significant yield loss. Last experiment was conducted to quantitatively understand the accumulation of lycopene and sugars in fruits as affected by EC and its application timing relative to the fruit ripeness stages. High EC treatment of 4.5 dS m-1, regardless of its application timing, enhanced TSS and sugar concentration in the juice and lycopene concentrations of the fruit. However, the delayed high EC treatment (application of high EC after 4 weeks of anthesis) showed less enhancement for TSS and sugar concentration. Lycopene concentration of the fruit in the delayed EC treatment reached the same level as that in the standard high EC treatment (application since anthesis), which suggests that enhanced lycopene development under high EC is more related to an abiotic stress response during the fruit maturation, rather than fruit mass balance altered by the limited water flux to the fruit.

Individual peripheral gustatory neurons in insects encode stimulus category (e.g. sweet, bitter) and concentration as a tonic rate of spiking that adapts with prolonged stimulation. While individual chemosensory neurons have been shown to interact through mutual inhibition, this interaction does not affect stimulus coding by the activated neuron. Here, I report the first evidence of a coherent, temporal pattern of spiking produced by the interaction of the gustatory receptor neurons (GRNs) within sensilla present on the mouthparts of bumblebees (Bombus terrestris) that encodes information about sugar concentration. Stimulation of gustatory sensilla with sucrose concentrations >10 mM elicited bursts of spikes riding on an oscillation in voltage of ~20 Hz. The concentration response function of spiking and bursting was sugar-identity specific, and only concentrations that produced bursting in the GRNs elicited the bee’s feeding reflex. Bursting bee GRNs exhibited a low rate of adaptation (0.002 s adaptation after 1 s of stimulation) compared to rates measured from other insect species’ GRNs. These data are the first to show that primary chemosensory neurons encode stimulus features such as concentration as a coherent temporal pattern of spiking produced as an interaction between two neurons. I propose that 1) the silent period between bursts is driven by the spike after-hyperpolarization of one neuron, which inhibits spiking of its neighboring neuron through an inhibitory lateral interaction, and 2) bursting is a novel mechanism evolved to allow persistent high frequency spiking during fluid consumption. Finally, I show that neural activity can be monitored from the bee’s central nervous system, which allows future experiments to question the function of this coherent and structured GRN activity in driving post-synaptic responses.

El procesado de alimentos conlleva, en mayoría de los casos, la generación de subproductos o residuos que pueden ser reutilizados o revalorizados mediante la utilización de técnicas de separación por membrana. Estas técnicas ofrecen la posibilidad de tratar las soluciones en condiciones de operación muy suaves, y no comportan en mayoría de las ocasiones, una alteración de los componentes a recuperar. Actualmente, las técnicas de separación por membrana, debido a su alta calidad y relativamente bajos costes, se encuentran completamente integradas en la mayoría de procesos productivos que requieren de una etapa de separación. Sin embargo, la investigación en el área de las técnicas de separación por membrana sigue abriendo nuevos campos de aplicación, que surgen con la mejora de las condiciones tecnológicas de los equipos y la posibilidad de obtener nuevas membranas adaptables a necesidades específicas.

En concreto, en este proyecto se utilizaron técnicas de separación por membranas para concentrar soluciones de azúcar procedentes de deshidratación osmótica (en adelante OD). El principal objetivo fue estudiar el potencial de varias técnicas de separación, haciendo hincapié en los flujos obtenidos durante la reconcentración y en la calidad de la solución reconcentrada.

La deshidratación osmótica es un tratamiento que permite una eliminación parcial del agua en un alimento y/o la incorporación de solutos de una manera controlada, respetando la calidad inicial del producto. El proceso consiste en introducir los alimentos en una solución hipertónica, controlando las condiciones de operación para favorecer, en mayor o menor grado la incorporación de solutos y la deshidratación del alimento. La aplicación de OD puede resultar en la mejora de las propiedades nutricionales y funcionales de los alimentos y en la reducción de la energía requerida para la deshidratación. El principal problema de la aplicación industrial de la OD radica en la gestión de la solución procedente del proceso. La reutilización de esta solución plantea una doble ventaja: primero desde el punto de vista ambiental, ya que se elimina un efluente del proceso que a menudo no puede ser vertido directamente, y segundo el ahorro económico que representa la recuperación de las materias primas que muchas veces contienen solutos de importante valor económico.

Los métodos de separación por membrana utilizados para recuperar las soluciones de OD fueron los siguientes: nanofiltración, osmosis directa y destilación osmótica por membranas. La nanofiltración (NF) presenta altos niveles de retención y un menor gasto de energía que la osmosis inversa, y en la industria azucarera se aplica como uno de los pasos en la clarificación y concentración de jarabes. En los procesos de contactores de membranas: osmosis directa (DO) y destilación osmótica por membranas (OMD), a diferencia de los procesos basados en el tamizaje, el flujo depende solamente de la diferencia de potencial osmótico. Las únicas presiones hidráulicas requeridas son las necesarias para bombear la solución de azúcar y la solución osmótica hasta la superficie de la membrana. Estas características hacen que estos procesos presenten como muy prometedores para la reconcentración de soluciones de azúcar de concentraciones elevadas.

Los experimentos de filtración se llevaron a cabo utilizando plantas piloto diseñadas y construidas expresamente para el presente proyecto. Durante todos los procesos de separación por membranas, se empleó como solución modelo una solución de sacarosa a diferentes concentraciones (5-60 ºBrix), debido a que las soluciones aplicadas en la deshidratación osmótica de frutas son habitualmente soluciones de azucares (sacarosa, glucosa o jarabes).

Durante los experimentos de NF se evaluó el funcionamiento de las membranas planas: Desal5 DK (GE- Osmonics), MPF-34 (Koch Membrane), NFT-50 (DSS) y tubulares: MPT-34 (Koch Membrane) y AFC 80 (PCIMembranes). Además de la solución de azúcar de diferentes concentraciones (5-20 ºBrix), se concentraron zumos de pera y manzana.


La reconcentración mediante osmosis directa se realizó utilizando dos modos de operación: off-site e on-site. En el modo off-site, la reconcentración por ósmosis directa se llevó a cabo en una planta de filtración provista de un módulo plano o tubular, dependiendo de la membrana. En el módulo se llevó a cabo la concentración. En el modo on-site, la deshidratación se realizaba conjuntamente con la reconcentración de la solución osmótica. La solución de reconcentración de la osmosis directa en off-site (offsiteDO) fue NaCl, mientras la solución de reconcentración de la osmosis directa on-site (on-site DO) fue una solución de sacarosa más concentrada que la solución osmótica (60 para una solución osmótica de 40 y 68 para una solución de 50 ºBrix). Para garantizar el flujo de agua entre las dos soluciones y altas retenciones de azúcar durante la off-site DO, se utilizaron membranas de NF planas (Desal5-DK y MPF-34) y tubulares (MPT-34 y AFC80). La reconcentración por osmosis directa on-site se levó a cabo empleando una membrana de microfiltración (Durapore, Millipore), ya que la solución de reconcentración (SS) es la misma que la solución osmótica y la alta viscosidad de la SS restringe mucho el flujo de agua si se utiliza una membrana más densa.

En la deshidratación por membranas (OMD) se utilizaron membranas hidrófobas (11806, Sartorius) que presentan una retención teórica del 100 %. Se comparó el rendimiento de dos soluciones de reconcentración: NaCl y CaCl2.

Con el fin de obtener información referente a la influencia de las propiedades de las membranas sobre el desarrollo del proceso de concentración de las soluciones procedentes de la deshidratación osmótica, se realizó un estudio detallado de las propiedades de las membranas aplicadas mediante AFM, SEM, FTIR, ángulo de contacto y medidas de potencial zeta. Con la finalidad de generar soluciones osmóticas para someterlas a reconcentración, y también para disponer de productos procedentes de deshidratación osmótica con soluciones frescas que pudieran compararse con aquellas procedentes de OD con solución reconcentrada, se deshidrataron diferentes lotes de manzana (Granny Smith) con soluciones de sacarosa de 40, 50 y 60 ºBrix. Estas pruebas permitieron determinar también el tímelo de operación para una máxima pérdida de agua con relativamente poca impregnación de las manzanas. Después de cada experimento se analizaron los siguientes parámetros: concentración de azúcar, pH, absorbancia a 420 nm de las soluciones y humedad de las manzanas.

La nanofiltración, aplicada en la primera fase del presente estudio, resultó ser viable solamente para la reconcentración de soluciones de concentraciones hasta 24 ºBrix. El aumento de la temperatura de 25 hasta 35 ºC para las dos membranas tubulares ocasionó un incremento del flujo de permeado, y el mismo efecto tuvo el aumento de presión transmembranaria de 8 a 12 bar.

Se comprobó que el factor más importante para la eficacia del proceso es disponer de una membrana que combine altos flujos y retenciones durante el proceso. La deposición de las partículas de sacarosa y/o los zumos se caracterizó mediante SEM y la topología de la capa filtrante de la membrana se identificó usando AFM. La topología de la capa filtrante de las membranas era diferente para cada una de ellas, a pesar de que todas estaban preparadas con el mismo material (poliamida). En las imágenes de los cortes transversales de las membranas realizados con SEM, se observaron los cambios en la estructura de las membranas producidos por la aplicación de presión durante los experimentos y las altas temperaturas empleadas durante su acondicionamiento. Gracias a las imágenes de SEM se pudo verificar también la eficacia del proceso de acondicionamiento de membranas.

A diferencia de NF, tanto la ósmosis directa como la destilación osmótica por membrana permiten la reconcentración de soluciones concentradas de sacarosa (hasta60 ºBrix). La eficacia de estas dos últimas técnicas se evaluó en unción de los flujos de agua obtenidos.

El sistema de ósmosis directa on-site propuesto para la reconcentración de las soluciones de OD permitió reutilizar las soluciones osmóticas como mínimo cuatro veces. Para la solución osmótica de 40 ºBrix la humedad de las manzanas fue similar utilizando solución fresca o reconcentrada. En cambio, una solución osmótica de 50 ºBrix, la pérdida de agua de las manzanas fue mayor cuando la deshidratación osmótica se llevó a cabo con reconcentración on-site de la solución osmótica. Los análisis de concentración de azúcar de las soluciones osmóticas y de la solución de reconcentración indican que la membrana elegida para los experimentos facilita el transporte óptimo de solutos y agua entre las dos soluciones. Además, el sistema de reconcentración por membrana propuesto es muy sencillo y de bajo coste porque no requiere presurización.

La osmosis directa en off-site proporcionó flujos mucho mayores que los obtenidos con el sistema on-site (1.3 kg/m2h para la solución osmótica de 50 ºBrix respecto a 0.0023 kg/m2h durante on-site DO para la misma solución). Sin embargo, el transporte de solutos de la solución de reconcentración hacía la solución osmótica puede ser considerado un obstáculo para su aplicación a escala industrial.

Los flujos de agua más elevados fueron obtenidos utilizando la OMD (2.01 kg/m2h para la solución osmótica de 50 ºBrix y con CaCl2 con la solución de reconcentración). Otra gran ventaja de este proceso es la retención de solutos que proporciona, hecho confirmado por los análisis realizados.

El estudio sobre el transporte durante los procesos de contactores de membranas indicó que la viscosidad es la propiedad limitante para la solución osmótica y la actividad de agua/alta presión osmótica como la propiedad más importante a la hora de elegir una solución de reconcentración. Para todos los procesos de separación aplicados, el aumento de la concentración de azúcar de la solución osmótica comporta una disminución notable del flujo de agua.

El desarrollo de un posible proceso de deshidratación osmótica con una etapa de reconcentración de la solución osmótica mediante procesos con contactores de membrana ha permitido calcular el área requerida para realizar la reconcentración: 3.6,9.7, 1608 m2 para OMD, off-site DO e on-site DO, respectivamente.

Las conclusiones del trabajo confirman la posibilidad de utilizar procesos por membrana para realizar la reconcentración de soluciones osmóticas. No obstante se ha constatado que técnicas más tradicionales basadas en diferencias de presión (NF) no son

The small size of nectarivorous birds is associated with high mass-specific metabolic rates and energetic lifestyles. Their energy balance is likely to be strongly influenced by environmental factors. Firstly, nectar varies in sugar concentration between different food plants and birds must adjust their consumption to maintain a constant energy intake. Secondly, unfavourable weather conditions, such as storms and heavy rains, may prevent birds from feeding, and they must increase their energy intake to compensate for the loss in foraging time. Low ambient temperature, as a third energetic challenge, results in higher energy demands for thermoregulation, which leads to increased food intake. However, these compensatory feeding responses may be constrained by physiological limitations to nectar ingestion, digestion and osmoregulatory processes. My research focused on the behavioural and physiological responses of captive sunbirds (Nectariniidae) and honeyeaters (Meliphagidae) to energetic challenges, namely variations in nectar quality and availability and in ambient temperature. For sunbirds, I also investigated on a novel short-term scale how feeding patterns are adjusted in order to compensate for alterations in energy intake or requirements. Feeding events were recorded using a photodetection system, and body mass was monitored continuously by connecting the perches to electronic balances, interfaced to a computer. Whitebellied sunbirds (Cinnyris talatala) were fed various nectar sugar concentrations. Their feeding durations were found to provide an estimate of meal size on all food concentrations. When exposed to a decrease in sugar concentration, birds generally demonstrated an increased feeding frequency and food intake within 10 min. The number and duration of meals increased in the first few minutes after return of a more concentrated diet. When whitebellied sunbirds and brown honeyeaters (Lichmera indistincta) were exposed to a 2 h fasting period during the day, they increased their nectar intake and energy accumulation after the fast. Sunbirds achieved this by increasing meal size but not meal frequency. However, both species weighed less in the evening following the fast than the previous evening, indicating that the compensation for lost foraging time was incomplete. During acute cold exposure, whitebellied sunbirds, amethyst sunbirds (Chalcomitra amethystina) and brown honeyeaters increased their nectar intake, but lost body mass irrespective of nectar sugar concentration. Honeyeaters ingested more food at subsequent cold exposure, suggesting physiological adaptation to high feeding rates. A chemical reactor model of digestive capacity, which assumes sucrose hydrolysis to be the limiting step in nectar digestion, accurately predicted maximal food intake in honeyeaters, but mostly underestimated it in sunbirds. Sugar assimilation efficiency was higher than 99% in whitebellied sunbirds and brown honeyeaters. Lastly, licking frequencies and tongue loads of whitebellied and amethyst sunbirds were investigated. In both species, tongue lick duration increased, and licking frequency and consumption per lick decreased, with increasing nectar concentration. Birds did not adjust their licking behaviour after a fasting period. In conclusion, the response to varied energy challenges is shaped by both compensatory feeding and physiological constraints. Although unrelated, sunbirds and honeyeaters showed convergence in their responses, probably due to their similar nectarfeeding lifestyle.
Thesis (PhD)--University of Pretoria, 2009.
Zoology and Entomology
unrestricted

Kuba har i dagsläget ett högt beroende av importerad olja, för att tillgodose sin växande efterfrågan på elektricitet. Importen sker främst från Venezuela. Detta beroende gör Kuba känsligt för ändringar i oljepriser samt det politiska klimatet. Den nuvarande krisen i Venezuela har haft en betydande inverkan på Kubas elproduktion. Genom att utöka landets förnybara energikällor kan Kuba minska sitt beroende av andra länder och diversifiera sin energiförsörjning. Detta kommer även att leda till en positiv miljöpåverkan då landets CO 2-utsläpp minskar. Kubas geografiska läge har ideala förhållanden för förnyelsebar energigenerering, så som solkraft. Solkraft utvecklas konstant och innehåller en hög potential. Concentrating Solar Power (CSP) är en teknologi där speglar och/eller linser används för att koncentrera solljus till en liten yta som konverterar solljuset till värme. Denna värme kan sedan användas i termodynamiska cykler. Det finns två huvudsakliga problem med implementering av CSP på Kuba. För det första är CSP beroende av momentana väderförhållanden, vilket leder till en oregelbunden elproduktion. För det andra har CSP höga investeringskostnader. För att adressera dessa problem, är det möjligt att implementera CSP i ett redan existerande kraftverk med regelbunden energikälla, d.v.s. skapa ett hybridkraftverk. På så vis uppnås regelbunden elproduktion med signifikant lägre investeringskostnad. Ett sådant existerande kraftverk kan hittas hos många av Kubas sockerbruk. Den här studien undersöker möjligheten att implementera solkraft i sockerbruket Carlos Baliño, beläget i Villa Clara, Kuba. Fabriken är självförsörjande av elektricitet på årlig basis. De använder en Rankine-cykel för att generera el och processvärme som används i sockerframställningen. Bränslet som används är bagasse, en restprodukt efter att sockerjuicen pressats ut ur sockerrören. Fyra CSP-teknologier och tre implementeringslayouts undersöktes, vilket resulterade i att parabolic trough-teknologin och förvärmning av vatten ansågs vara de bästa alternativen för Kuba och Carlos Baliño. Vidare undersöktes två olika scenarier för CSP. Scenario 1 innefattar implementering av CSP i sockerbruket under rådande skick och Scenario 2 består av implementering av CSP efter en investering gjorts i en Condensing Extraction turbin (CEST). Resultatet visar att Carlos Baliño bör investera i CEST innan de implementerar CSP, det vill säga Scenario 2. Detta beror på att i scenario 1 är det inte möjligt att generera elektricitet utanför sockersäsongen, vilket leder till att en stor del av solpotentialen inte kan utnyttjas. Den maximala investeringskostnaden för scenario 1 är 3,7 MUSD, vilket inte är en realistisk kostnad. Den maximala investeringskostnaden för scenario 2 beror av tillgänglig bagasseimport och är 5,9 – 7,2 MUSD. Att investera i CSP rekommenderas ej om bagasseimporten är obegränsad. Givet att bagasseimporten är begränsad skulle CSP-implementeringen leda till en utökad elproduktion av 5,4 – 7,2 GWh/år, en årlig minskning av oljeanvändandet med 16 100 – 21 800 tunnor och minskade CO2-utsläpp med 12 00-16 00 ton årligen. Carlos Baliños ekonomiska resultat skulle öka med 0,5 MUSD/år och den kubanska statens med 0,7 – 0,9 MUSD/år. Framtida studier rekommenderas undersöka möjligheten till generering av el året runt vid Carlos Baliño utan en CEST, solkraftsefterfrågan på nationell nivå och potentiella utvecklingar av solkraft hos Carlos Baliño.
Cuba is currently highly dependent on imported oil, mainly from Venezuela, to meet their growing electricity demand. This dependence makes Cuba sensitive to changes in oil price as well as the political climate. The current crisis in Venezuela has a large impact on Cuba’s electricity generation. By expanding its renewable energy sources Cuba could decrease their dependence on other countries and diversify their energy supply. Moreover, it would have a positive climate impact by reducing the country’s CO2-emissions. Geographically, Cuba has ideal conditions for renewable energy utilization, such as solar power. Solar energy is constantly progressing and is considered a great source of energy. Concentrating Solar Power (CSP) is a technology which applies mirrors and/or lenses to concentrate the sunlight onto a small area which converts the sunlight into heat, possible to use in a thermodynamic cycle. There are mainly two problems with the implementation of CSP in Cuba. Firstly, CSP is a non-dispatchable power generating system since it is dependent on the instantaneous weather conditions. Secondly, it has high investment costs. One way of solving these problems is by implementation CSP in an already existing power plants with a dispatchable source of energy, making it a hybrid power plant. Accordingly, the hybrid power plant would be dispatchable and the investment costs would be significantly lower. Existing power plants can be found in Cuban sugar mills. This study investigates the possibility to implement solar power in the sugar mill Carlos Baliño, located in Villa Clara, Cuba. The factory is currently self-sufficient electricity wise on a yearly basis, using a co-generation Rankine cycle to generate electricity and process heat used in the sugar production. The fuel used is bagasse, a rest product obtained after the sugar juice has been pressed out of the sugar canes. Four CSP-technologies and three implementation layouts were examined, resulting in the parabolic trough-technology and feedwater heating being considered the optimal solution. Furthermore, two different scenarios for CSP was investigated; implementation of CSP in the mill at the current state (scenario 1) or after investing in a Condensing-Extraction Turbine (CEST) (scenario 2). The results show that Carlos Baliño should invest in a CEST before considering implementation of CSP. Off-season operation is not available for scenario 1, leading to a vast amount of solar potential being unexploited. The maximal investment allowed for scenario 1 is 3.7 MUSD, which is not a realistic number. The maximal investment allowed for in scenario 2 is 5.9 – 7.2 MUSD, depending on bagasse import availability. If bagasse import is unlimited, it is not recommended to invest in solar power. Implementation of CSP in scenario 2 regarding bagasse import limits would yearly lead to an additional electricity generation at Carlos Baliño of 5.4 – 7.3 GWh, decrease the oil usage with 16,100 – 21,800 barrels and the CO2-emissons with 1,200 – 1,600 tonnes. Carlos Baliño’s annual yield would increase with 0.5 – 0.6 MUSD/year and the Cuban states annual yield would increase with 0.7 – 0.9 MUSD/year. Future work is recommended to explore alternatives to all year-around electricity generation in Carlos Baliño without investing in a CEST, investigate solar power demand on a national level, and examine possible developments of the suggested solar field, for instance solar-only operation.

Birds are a major pest in vineyards both in New Zealand and overseas. There is a need for new behavioural research on birds' foraging habits and feeding preferences in vineyards, as much of the literature to date is anecdotal. Research on cues to birds' feeding will provide a basis on which new deterrent and control strategies can be devised. Spatial-and temporal bird damage in a small vineyard block was mapped to find if damage was correlated with grape maturity and environmental factors. Vineyard and field observations of bird behaviour using video technology combined with preference experiments aimed to establish the relative roles of grape sugar concentration and colour in avian selection. Proximity of vineyards to bird roosts affects damage levels, regardless of differing maturity between locations. The rate of damage tends to increase exponentially once grape maturity has passed a threshold of 13 °Brix. Bunches positioned closest to the ground receive more damage if blackbirds or song thrushes are the predominant pests. Both sugar concentration and grape colour were found to affect birds' feeding preference, but the importance of the two factors varied between years. Black and green grape varieties were differentially preferred by blackbirds (Turdus merula) and song thrushes (Turdus philomelos) while silvereyes (Zosterops lateralis) appeared to have no strong colour preference. It was apparent that there were other, not assessed, grape factors that also affect selection. In small unprotected vineyards that are adjacent to bird roosts the entire grape crop can be taken by bird pests. Besides removing the roosts, which can be beneficial shelterbelts in regions exposed to high winds, growers currently may have no alternative other than to use exclusion netting to keep crops intact. The differential preferences between bird species for variety characteristics suggest that any new deterrents and other strategies to deflect birds from grape crops may need to be species-specific.

The effect of fruit removal from cantaloupe was studied under field conditions in a soil naturally infested with Monosporascus cannonballus. Fruit removal resulted in greater sugar accumulation in the cantaloupe roots compared to the roots from plants on which the fruits were allowed to develop normally. Individual, total, and combined root carbohydrate levels were greater in plants without fruit than in plants with fruit. Five major sugars (stachyose, raffinose, sucrose, glucose, and fructose) were found in the cantaloupe roots. Stachyose concentrations were higher than all the other sugars in the cantaloupe roots. Disease severity on the cantaloupe roots with fruit removed was less severe than on roots of plants with fruit, and dry weights were higher in the fruit removal treatment than those of the fruit non-removal treatment. Fruit removal results in increased root growth and carbohydrate accumulation in the cantaloupe roots. Root sugar concentrations affected infection efficiency and disease progress of Monosporascus root rot and vine decline. Therefore, the retarded development of Monosporascus root rot and vine decline is associated with a greater carbohydrate accumulation in the cantaloupe root.

Le changement climatique en cours entraîne une augmentation de la fréquence et de l'intensité des événements météorologiques extrêmes, affectant la composition des raisins. Les températures élevées pendant la maturation augmentent la teneur en sucre du moût et réduisent les teneurs en acides organiques et en anthocyanes, modifiant qualité et typicité du vin. Les pratiques telles que les manipulations du rapport feuilles/fruits combinées à des applications d'hormones végétales peuvent potentiellement être utilisées pour adapter et maintenir la durabilité de la production viticole. Dans ce but, il est nécessaire de mieux comprendre les liens physiologiques entre accumulation de sucres et synthèse d'anthocyanes au cours de la maturation des baies.Des boutures fructifères de vigne (cv. Cabernet sauvignon) ont été cultivées en serre et différents rapports feuilles/fruits (2 à 12 feuilles par grappe) ont été appliqués et combinés à la pulvérisation d'acide abscissique (ABA) sur les baies au stade de pré-véraison. Pour étudier les mécanismes sous-jacents à l'effet de la manipulation du rapport feuille-fruit et de l'application d'ABA sur la composition des baies, l’expression de gènes liés au métabolisme des sucres, des anthocyanes et de l'ABA a été étudiée sur ce matériel. Afin de réaliser une analyse fine de l'interaction potentielle sucres/signalisation par l’ABA sur la biosynthèse des anthocyanes, des expériences de culture de baies in vitro ont également été menées. Les baies ont été cultivées 2-3 semaines sur un milieu solide supplémenté avec différents niveaux de sucre (0%, 2%, 8%), combinés avec de l'ABA (200 µM), un inhibiteur de biosynthèse d’ABA, ou des inhibiteurs d'hexokinase.Les résultats confirment que la réduction du rapport feuille/fruit a un effet significatif sur la composition des baies: réduction de la teneur en sucres et en anthocyanes, augmentation des concentrations en acides organiques totaux, modification de la composition en acides aminés libres. L'application d'ABA augmente les teneurs en sucres et en anthocyanes, et restaure donc partiellement le couplage entre accumulation de sucre et d'anthocyanes, sous de faibles ratios feuille-fruit, sans affecter les ratios acides aminés/sucres/acides organiques. Plusieurs gènes de la voie de biosynthèse des anthocyanes (CHS2, CHS3, CHI, F3H, DFR, LODX, UFGT, MybA1, MybA2) sont réprimés en situation de faible rapport feuille/fruit ; alors qu’une partie d’entre eux sont au contraire induits (CHI, F3H, F3'5'H, LODX, UFGT, MybA1, MybA2) après un traitement ABA. L'ABA a en revanche peu d'effet sur les gènes liés à l'accumulation des sucres ; de même que le rapport feuille/fruit sur les gènes de biosynthèse de l'ABA. Les expériences de culture in vitro de baies ont montré que l'ABA et les concentrations élevées de glucose induisent de manière synergique la biosynthèse des anthocyanes pendant la maturation. L'ABA et le glucose ont diminué la concentration en phénylalanine dans les baies en cours de maturation, très probablement en raison de leur rôle dans l’accroissement de la synthèse des anthocyanes, et une analyse ANOVA croisée à deux facteurs indique une interaction significative entre les niveaux de sucre et d'ABA et l'accumulation d'anthocyanes.En conclusion, nos travaux ont montré que l'ABA et la signalisation par les sucres interagissent pour réguler l'expression des gènes de biosynthèse des anthocyanes et augmenter l'accumulation d'anthocyanes pendant la maturation des baies. L'application d'ABA a conduit à l’augmentation du rapport anthocyanes/sucres à la récolte, en conditions de faible rapport feuilles/fruits. La combinaison de la manipulation du rapport feuille/fruit avec des applications d'ABA permet donc de réduire la concentration en sucres à la récolte, tout en maintenant les concentrations en anthocyanes, offrant ainsi un moyen potentiel d'atténuer partiellement les effets négatifs des températures élevées liées aux modifications climatiques en cours
Ongoing climate change causes extreme weather events to increase both in frequency and intensity, significantly affecting vine physiology and grape berry composition at harvest. Elevated temperatures during the growing season increase must sugar content, while reducing organic acids and anthocyanins levels, modifying wine quality and typicality. Viticultural practices such as leaf-to-fruit ratio manipulations combined with applications of plant hormones can potentially be used to adapt to climate change and maintain the sustainability of wine production. To optimize adaptation strategies, we need to gain better insights into the links between sugars and anthocyanins accumulation during berry development and ripening.Fruiting-cuttings made up of one vertical shoot with one grape cluster of cv. Cabernet Sauvignon were grown between 2013 and 2018 in a naturally lighted and semi-controlled greenhouse. Various leaf-to-fruit ratios (2 to12 leaves per cluster) were applied, and combined with spraying abscisic acid (ABA, 400 mg.L-1) on berries at the pre-veraison stage. To explore the biological mechanisms underlying the effect of leaf-to-fruit ratio manipulation and application of exogenous ABA on berry composition, transcript abundance of genes related to sugar, anthocyanins and ABA metabolism were studied in this material. To further analyze the potential interplay between sugar and ABA signaling on anthocyanins biosynthesis, in vitro berry culture experiments were also conducted. Berries were cultured 2-3 weeks on solid medium supplemented with different sugar levels (0%, 2%, 8%) combined with ABA (200 µM), ABA biosynthesis inhibitor (NDGA), or hexokinase inhibitors (NAG, GDH).The results confirmed that reducing the leaf-to-fruit ratio had a significant effect on berry composition: reduction of sugar and anthocyanin content, slight increase in total organic acids and modification of the free amino acids composition. Exogenous ABA application increased sugars and anthocyanins concentrations, and partially restored the coupling between sugar and anthocyanins accumulation under low leaf-to-fruit ratios, without affecting the amino acids/sugar/organic acids ratios. Transcript abundance analysis revealed that several anthocyanin biosynthetic genes (CHS2, CHS3, CHI, F3H, DFR, LODX, UFGT, MybA1 and MybA2) were decreased under low leaf-to-fruit ratio, whereas some genes (CHI, F3H, F3’5’H, LODX, UFGT, MybA1 and MybA2) were up-regulated after exogenous ABA treatment. Exogenous ABA had little effect on the transcript abundance of sugar accumulation related genes, and leaf-to-fruit ratio also had little effect on ABA biosynthetic genes. Berry in vitro culture experiments showed that ABA and elevated concentrations of glucose synergistically induced anthocyanins biosynthesis during ripening. Both ABA and glucose decreased Phenylalanine concentration in ripening berries, most probably due to their role in promoting anthocyanins synthesis, and two-way crossed ANOVA analysis indicate a significant interaction between sugar and ABA levels and anthocyanin accumulation in berries.In conclusion, our results showed that ABA and sugar signaling synergistically interact to regulate the expression of anthocyanin biosynthetic genes and increase anthocyanins accumulation during berry ripening. Thus, exogenous ABA application was able to increase the ratio of anthocyanins to sugar under low leaf-to-fruit ratio at harvest, and combining leaf-to-fruit ratio manipulation with exogenous ABA applications may offer a fine-tuned way to reduce sugar concentration, while maintaining anthocyanin concentrations in grape berry, potentially offering a way to partially alleviate climate change related high temperature effects

Approximately 75 percent (300 000 km) of the total Swedish road network and 20 percent(20 000 km) of the national road network consists of gravel roads. One of the most significantproblems associated with gravel roads is traffic-generated dust emission, which contributes tothe deterioration of the road surface and acts as a major source of particulate matter releasedinto the atmosphere, thereby involving public economics, road safety, human health, andenvironmental quality. In order to bind the fine granular material, which is prone to rise into theair, dust suppressants are applied on roads on a yearly basis. Methods for evaluating the efficiency of dust suppressants will facilitate in the selection of themost appropriate product and its optimal application rate. For example, methods forsupervision of residual dust suppressant concentration are valuable tools for estimatinglongevity and optimal application rates, and, consequently, effectiveness of different products. Application of the proper dust suppressant to a gravel road ensures road safety and ridingcomfort as well as creating a cleaner and healthier environment for residents in buildingsadjacent to the road. It also reduces the need and cost for vehicle repair, road maintenanceactivities, and aggregate supplementation. Both field-based and laboratory research were performed to evaluate the efficiency of varioussuppressants and the influence such factors as product concentration, leaching, and fine materialcontent have on the efficiency of different products. Within the field-based research, a newlydeveloped mobile methodology was used to measure dust emission on numerous test sectionstreated with various dust suppressants. In general, all dust suppressants tested, except apolysaccharide (sugar) and products, which form a brittle surface crust, i.e. lignosulphonate andbitumen emulsion, showed acceptable dust reduction. Test sections treated with a magnesium- or calcium chloride solution were the most effectivelydust suppressed. The application of solutions instead of a solid salts achieves a more uniformproduct distribution and, therefore, probably a more efficient performance. By applying acalcium- or magnesium chloride solution instead of traditionally used solids, the cost for annualdust control, as well as the environmental impact from the release of these chemicals in theenvironment, can be reduced by 50 percent. A significant problem when using dust suppressants is their tendency to leach during rainfalldue to their soluble properties. Residual chloride could be detected in the gravel wearing courseover a longer period of time than lignosulphonate and, therefore, showed more effective longtermperformance. Optimal percentages of fine material for minimal lignosulphonate andchloride leaching were found to be 15 percent by weight and 10-16 percent by weight,respectively. Ions of calcium chloride seemed to initiate flocculation of clay particles, therebypreventing them from leaching. Still, the fine material in gravel wearing courses has to be replenished regularly as indicated by studies of the longevity of fine material. Loss up to80 percent was found after two years. Toxicity tests show that dust suppressant application for dust control purposes, at traditionallyused application rates, does not constitute a threat to sensitive aquatic life. Tests on subsoilwater samples indicated elevated chloride levels, which possibly could cause corrosion to pipes,but not high enough to flavour drinking water.
QC20100616

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Néctar; entomofauna; Merremia aegyptia
O objetivo deste trabalho foi o de investigar se os diferentes horários de coleta de néctar em áreas apícolas influenciam no volume, concentração de açúcar e açúcar total produzido por suas flores, no momento da antese, bem como verificar possíveis alterações nas características do néctar ao longo do tempo e discutir as conseqüências no potencial apícola das áreas de jitirana-branca (Merremia aegyptia). E ainda, a relação entre esta produção de atrativos florais e o comportamento dos polinizadores potenciais, dentre estes a Apis mellifera L. (abelha africanizada), e os requerimentos de polinização da jitirana branca. A pesquisa foi realizada em uma área de preservação de Caatinga, no Campus da FATEC Sertão Central, Quixeramobim-Ceará. Foi constatado que: A jitirana branca é uma cornucópia; sua densidade floral por m² foi em média 33,7 flores; apresentou ampla gama de visitantes florais (hymenopteros, coleópteros, hemípteros, dípteros, e pássaros); seu volume de néctar variou de acordo com o horário de coleta e não há reposição de néctar na flor após as 11:00 horas (A.M.); e a polinização mais eficiente corresponde a autopolinização.

Développer la connaissance des réponses du développement des fruits aux pratiques agricoles et aux conditions environnementales est important, depuis les sélectionneurs jusqu’aux producteurs. Cela soutiendrait la conception de pratiques agricoles permettant d’augmenter le rendement et la qualité des fruits et d’adapter la production fruitière au changement climatique, afin de satisfaire la croissance de la demande alimentaire. Le but de cette thèse était d'utiliser et d'améliorer un modèle mécaniste de croissance du fruit pour explorer la variabilité génétique de la tomate, concevoir des idéotypes de tomate plus résistants à la sécheresse, mettre en évidence des modes de circulation de l’eau et des sucres dans le système pédicel-fruit au cours de la journée, et étudier les effets des variations des concentrations en solutés dans la pulpe des fruits sur la croissance, qui détermine la qualité des fruits à la récolte. Les modèles développés ont permis de décrire de manière adéquate les processus biophysiques et métaboliques déterminant la croissance des fruits et la composition des solutés. Les résultats de simulation du modèle obtenus suggèrent que la conductivité pédiculaire et l'absorption active des sucres pourraient être des mécanismes clés pour déterminer la variabilité génétique des fruits et devraient être maximisés dans la recherche d'idéotypes. De plus, les résultats obtenus suggèrent que la régulation des flux d'eau peut générer une régulation de l'absorption diurne de sucre par le fruit et pourrait prévenir la perte d'eau au travers de la recirculation entre le xylème et le phloème et entre le phloème et l’apoplasme. Enfin, les résultats obtenus à partir d'un modèle intégré incluant la description de la croissance des fruits et du métabolisme des solutés de fruits ont mis en évidence que la variation des concentrations en acides et en minéraux due aux processus d'accumulation et de dilution pourrait avoir un impact non négligeable sur la croissance des fruits. Les études présentées dans cette thèse ont mis en évidence que l'estimation des paramètres physiologiques de la croissance des fruits et les techniques de conception et de calibration des modèles devraient être améliorées pour les rendre plus adaptés à la conception de meilleurs pratiques agricoles
Developing knowledge on fruit development responses to agricultural practices and environmental conditions is important from breeders to growers. Indeed, this would support the design of agricultural practices that could increase fruit yield and quality and adapt fruit production to climate change, for satisfying the increasing food demand. The aim of this thesis was to use and improve a mechanistic model of fruit growth for exploring the genetic variability of tomato growth in fresh and dry mass, designing drought-resistant tomato ideotypes, underlining patterns of diurnal water and sugars flows in the pedicel-fruit system, and studying the effects on fruit growth of the variations of fruit pulp solutes concentrations that determine fruit quality at harvest. The models developed allowed to describe in an adequate way biophysical and metabolic processes determining fruit growth and solutes composition. The obtained model simulation results suggested that pedicel conductivity and sugars active uptake could be key mechanisms in determining the fruit genetic variability and should be maximized in the research of ideotypes. In addition, the obtained results suggested that water flows regulation may generate a diurnally regulated fruit sugar uptake and could prevent water loss through water recirculation between xylem and phloem and between phloem and apoplast. Finally, the results obtained from an integrating model approach including the description of fruit growth and fruit solutes metabolism highlighted that acids and minerals concentrations variation due to both accumulation and dilution processes could have a non-negligible impact on fruit growth. The works presented in this thesis have highlighted that the estimation of the fruit growth physiological parameters and the techniques of models conception and calibration should be improved to make them increasingly suitable for the design of better-suited agricultural practices

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CNPQ
Neste trabalho foram desenvolvidos métodos analíticos, baseados no conceito de multicomutação, para análise de espécies químicas em alimentos. Para isto, foram sintetizados dois materiais: um composto de coordenação usado como fase sólida na determinação de açúcares redutores e uma rede de sílica utilizada como resina de pré-concentração de percloratos. O composto de coordenação cobre (II) - 4,4 '- bipiridina foi usado no desenvolvimento do método para a determinação de açúcares redutores em água de coco e sucos empregando sistema em fluxo multicomutado com detecção espectrofotométrica. A metodologia de análise baseou-se na reação de oxi-redução em meio alcalino entre o reagente sólido e os açúcares redutores. A reação entre a fase sólida (de coloração azul) com (glicose + frutose) resulta em produto de cor amarelada, monitorada em 420 nm. A fase sólida foi fixada em 50 mg e temperatura de 90ºC. Com volume de zona de amostragem de 160 L, que corresponde a 20 ciclos, obtendo resposta linear entre 1,0 e 20,0 g L-1 de AR com RSD de 4,47% (n = 7 ), limite de detecção de 0,2250 g L-1, limite de quantificação de 0,7496 g L-1, freqüência analítica de 75 determinções por hora e geração de efluentes de 320 μL por determinação. Os teores de açúcar redutor encontrados em sucos e água de coco variaram de 38,35 a 98,50 g L-1 e 61,80 a 68,70 g L-1 respectivamente. A rede de sílica, 2,5,8,11,14-pentaoxa-1-silaciclotetradecano, foi empregada num sistema multicomutado como coluna de pré-concentração de perclorato. O sistema foi acoplado a um detector potenciométrico para determinar percloratos em vegetais. Usou-se um eletrodo tubular com membrana constituída por 1% (m/m) de BNIP 4,4 Dapm LC1 solubilizado em 68% (m/m) de 2-nitrodifeniléter, como solvente mediador e 31% (m/m) de poli (cloreto de vinila). Obteve-se limite de detecção de 2,8x10-7 mol L-1, resposta linear no intervalo de 1,0x10-9 a 1,0x10-1 mol L-1, coeficiente de correlação linear de 0,9998 e a coluna apresentou uma capacidade de retenção de 2,86x10-3 mol de perclorato. O sistema foi aplicado às amostras de diferentes vegetais e foram encontradas concentrações de percloratos de 1,30 a 5,08 µg L-1 o teste recuperação variou de 96,5 a 110,8 %.
Two new multicommutation-based analytical methods were developed aiming to the quantification of chemical species in food. The first method is intended to the determination of reducing sugars in coconut water and fruit juices, while the second one is a potentiometric determination of perchlorates in horticultural products. The method eveloped for the determination of reducing sugars uses a multicommuted flow system with spectrophotometric detection employing a (copper (II) - 4,4’ – bipyridyl) coordination compound as the solid-phase reagent. The reaction of the solid blue phase with glucose/fructose resulted in a yellowish solution, which was monitored at 420 nm; 50 mg of the solid phase was used and the temperature was set at 90ºC. The volume of the sample zone was, 160 L, corresponding to 20 cycles, with a linear response of 1.0 e 20.0 g L-1 to the RA and RSD of 4.47% (n = 7), detection limit of 0.2250 g L-1, the limit of quantification was 0.7496 g L-1, analytical frequency of 75 determination per hour and effluent generation of 320 L per determination. The potentiometric method used to determine perchlorates used a tubular electrode formed by a polymeric membrane which showed the best features consisted of 1% (w/w) BNIP Dapm LC1 solubilized in 68% (w/w) of 2-nitrodiphenyl ether as a mediator solvent and 31% (w/w) poly(vinyl chloride) as the polymeric matrix. A limit of detection of 2.8x10-7 mol L-1 was obtained with a linear response in the range of 1.0x10-9 at 1.0x10-1 mol L-1, linear correlation coefficient of 0.9998 and the column retention capacity 2.86x10-3 mol perchlorate. Was applied to samples of different vegetables found perchlorates 1.30 to 5.08 µg L-1 and recovery between 96.5 and 110.8%.

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As microalgas produzem quantidades elevadas de compostos, principalmente lipídeos e açúcares. Quando essas são submetidas a variações de nutrientes podem elevar consideravelmente a concentração desses compostos, os quais são empregados para a produção de alimentos, biocombustíveis, cosméticos e componentes farmacêuticos. Esta pesquisa objetivou realizar o cultivo da microalga Chlorella sp., em fotobiorreator aberto de campo com diferentes concentrações de nutrientes, em seis tratamentos distintos (TC, T1, T2, T3, T4 e T5), secar as biomassas dos diferentes tratamentos e caracterizá-las quanto aos parâmetros físicos, químicos e físicos-químicos, como também construir suas isotermas de adsorção de umidade a 25ºC. A estirpe utilizada neste trabalho foi isolada da barragem da Conceição, localizada na Fazenda Tamanduá, Santa Teresinha, PB, e o meio utilizado foi meio MC. (Medium Chlorella ellipsodea). As características da microalga durante 16 dias de cultivo foram avaliadas com relação ao crescimento celular (peso úmido e peso seco), teor de lipídeos e açúcares totais. De acordo com os resultados verificou-se que a maior produção de biomassa daChlorella sp. em termos de peso seco, foi alcançada nos tratamentos TC, T1, T2 e T5 no 10º dia de cultivo e que com a redução nos tratamentos das concentrações de nitrogênio, fósforo, potássio e ferro houve aumento da síntese de lipídeos; para os tratamentos T3 e T4 o maior peso seco foi atingido no 12º e 16º dias de cultivo, respectivamente. A redução nas concentrações dos elementos nitrogênio, fósforo, potássio e ferro não favoreceru o aumento da produção dos minerais, proteínas, clorofila e feofitina. Os modelos de GAB, Peleg e Oswin podem ser usados para estimar as isotermas de adsorção de umidade, a 25ºC, da Chlorella sp. secas de todos os tratamentos,e foram classificadas como tipo II (TC, T1 e T5) e tipo III (T2, T3 e T4). Diante dos resultados constatou-se que a produção da biomassa da Chlorella sp. apresenta grande potencial de aplicação industrial para a produção de lipídeos e carboidratos com menores concentrações de NPK e ferro, que são os elementos de maior custo na produção de biomassa para aplicações nas áreas de alimentos e energia.
Microalgae produce high amounts of the compounds, mainly lipids and sugars. When these are subjected to nutrient variations can greatly increase the concentration of these compounds, which are used for food production, biofuel, cosmetic and pharmaceutical components. This research aimed to carry out the cultivation of icroalgae Chlorella sp.,Open photobioreactor field with different concentrations of nutrients in six different treatments (TC, T1, T2, T3, T4 and T5), dry biomasses of different treatments and character- them as to the physical, chemical and physical-chemical parameters, but also build their moisture adsorption isotherms at 25 ° C. The strain used in this study was isolated from the Conception dam, located in Tamanduá Farm, Santa Teresinha, PB, and the medium was medium MC. (Medium Chlorella ellipsodea). The microalgae features for 16 days of culture were evaluated with respect to cell growth (wet weight, dry weight), lipid content and total sugars. According to the results it was found that the higher biomass Chlorella sp. in terms of dry weight was achieved in the TC treatment, T1, T2 and T5 on the 10th day of culture and treatments with the reduction in the concentrations of nitrogen, phosphorus, potassium and iron was increased lipid synthesis; for treatments T3 and T4 the highest dry weight was achieved in the 12th and 16th day of cultivation, respectively. The reduction in the concentrations of the elements nitrogen, phosphorus, potassium and iron did not favor increased production of minerals, proteins, chlorophyll and pheophytin. The models of GAB, Oswin Peleg and can be used to estimate the moisture adsorption isotherms at 25 ° C, the Chlorella sp. dry all treatments and were classified as Type II(CT, T1 and T5) and type III (T2, T3 and T4). From the results it was found that the production of biomass Chlorella sp. It has great potential forindustrial application for the production of lipids and carbohydrates with lower NPK and ironconcentrations, which are the largest cost component in the production of biomass for applications in the areas of food and energy.

碩士
中山醫學院
營養科學研究所
86
Glucose/glycine and galactose /glycine model systems used to study the effects of sugar, temperature and concentration of sugar on Maillard browning and production of pyruvaldehyde. 　　Results showed that the effects of sugar concentration on browning rate correlated linearly to sugar concentration; in addition, browning rate of galactose/ glycine system was higher than that of glucose/glycine system. However, production of pyruvaldehyde in galactose/glycine system was much less than that in glucose/glycine system at 60°Ｃ.The yield of pyruvaldehyde in glucose/glycine system (181□g/100ml)was3.6 folds that of galactose/glycine system (50□g/100ml)at 48 hr,We also founded that higher tmeperature promoted the change of pH, which in turn effect more significantly on Maillard reaction.

Chu Lut-Hey.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2004.
Includes bibliographical references (leaves 137-140).
Abstracts in English and Chinese.
Abstract --- p.II
Acknowledgement --- p.V
List of Tables --- p.IX
List of Figures --- p.X
List of Abbreviations --- p.XIII
Chapter 1 --- Introduction
Chapter 1.1 --- Objectives.l --- p.1
Chapter 1.2 --- What is diabetes mellitus?. --- p.1
Chapter 1.3 --- "Review of ""Technique for blood glucose measurement""" --- p.3
Chapter 1.3.1 --- Conventional blood glucose meter --- p.4
Chapter 1.3.2 --- Semi-invasive blood glucose meter --- p.5
Chapter 1.3.3 --- Surfacelasmon resonance (SPR) method --- p.6
Chapter 1.3.4 --- Non-invasive blood glucose meters --- p.7
Chapter 1.4 --- Research directions --- p.8
Chapter 1.5 --- Data analysis methods --- p.9
Chapter 1.6 --- Organization of the thesis --- p.10
Chapter 2 --- Spectral Data Analysis Methods
Chapter 2.1 --- What is spectral data? --- p.12
Chapter 2.2 --- Nature of spectral data --- p.12
Chapter 2.3 --- How to interpret the spectral data? --- p.15
Chapter 2.3.1 --- Linear regression --- p.15
Chapter 2.3.2 --- Multiple linear regression (MLR) --- p.17
Chapter 2.3.2.1 --- Data reduction --- p.19
Chapter 2.3.3 --- Bilinear modeling (BLM) --- p.21
Chapter 2.3.3.1 --- artial least square regression (PLSR) --- p.23
Chapter 2.3.3.2 --- Model reliability --- p.24
Chapter 2.3.3.3 --- LS segmentation analysis --- p.25
Chapter 2.4 --- Session discussion and conclusion --- p.27
Chapter 3 --- Surfacelasmon Resonance (SPR) Experiments and Analysis
Chapter 3.1 --- Intrcduction --- p.29
Chapter 3.2 --- Theory --- p.30
Chapter 3.2.1 --- Maxwell's equations --- p.30
Chapter 3.2.2 --- olarization of EM wave --- p.32
Chapter 3.2.3 --- Boundary condition --- p.33
Chapter 3.2.4 --- Total internal reflection --- p.37
Chapter 3.2.5 --- hase shift of total internal reflection wave --- p.38
Chapter 3.2.6 --- Kretschmannrism configuration --- p.38
Chapter 3.2.7 --- Conditions affecting SPR --- p.41
Chapter 3.3 --- Different SPR configuration systems --- p.44
Chapter 3.3.1 --- rinciple of angular-based interrogation SPR setup --- p.44
Chapter 3.3.2 --- rinciple of intensity-based interrogation SPR setup --- p.45
Chapter 3.3.3 --- rinciple of wavelength-based interrogation SPR setup --- p.45
Chapter 3.3.4 --- hase-based interrogation SPR setup --- p.47
Chapter 3.3.4.1 --- Michelson Interferometer --- p.48
Chapter 3.3.4.2 --- Thehase-based setup --- p.49
Chapter 3.3.5 --- Comparison and discussion of different configurations --- p.51
Chapter 3.4 --- SPR experiment adopts wavelengths-based interrogation setup --- p.54
Chapter 3.4.1 --- The experiment setup --- p.54
Chapter 3.4.1.1 --- Samplereparation --- p.58
Chapter 3.4.1.2 --- Experiment Result using 928 nm and 1120 nm initial resonant wavelength --- p.58
Chapter 3.4.2 --- Experimental data analysis --- p.60
Chapter 3.4.2.1 --- Conventional SPR data analysis --- p.61
Chapter 3.4.2.1.1 --- Data analysis using minimum hunting witholynomial fit --- p.62
Chapter 3.4.3 --- LS regression analysis for SPR data --- p.67
Chapter 3.5 --- Session discussion and conclusion --- p.71
Chapter 4 --- Near-Infrared Spectroscopy Experiment and Analysis
Chapter 4.1 --- Overview of near-infrared spectroscopy --- p.74
Chapter 4.1.1 --- Electromagnetic spectrum --- p.75
Chapter 4.1.2 --- Molecules vibration --- p.76
Chapter 4.1.3 --- Law of absorption: Lambert-Beer Law --- p.77
Chapter 4.2 --- Near Infrared Spectrometer --- p.79
Chapter 4.2.1 --- Dispersive NIR spectrometer --- p.79
Chapter 4.2.2 --- Fourier-Transformed NIR spectrometer --- p.83
Chapter 4.2.3 --- Comparison between dispersive NIR and FT-NIR spectrometers --- p.85
Chapter 4.2.4 --- Self-established monochromator based spectrometer --- p.87
Chapter 4.2.4.1 --- Choose of detector andhotonic signal conversion unit --- p.90
Chapter 4.3 --- Experimental result of NIR-spectrum by self-established spectrometer --- p.95
Chapter 4.3.1 --- New approach for improving RMSEP without normalization of water spectrum as background information --- p.105
Chapter 4.4 --- Experimental results of NIR-spectrum by commercial spectrometers --- p.109
Chapter 4.5 --- Instrumentation limitation of NIR spectrometer --- p.117
Chapter 4.6 --- Session Discussion and conclusion --- p.119
Chapter 5 --- Conclusions and Suggestions for the Future Work
Chapter 5.1 --- Research aim and contributions --- p.126
Chapter 5.2 --- Discussion on experiments --- p.128
Chapter 5.3 --- Future work --- p.131
Chapter 5.4 --- Conclusion --- p.134
Reference: --- p.136
Appendixes: --- p.141
Appendix A Different approaches for non-invasive glucose measurement --- p.142
Appendix B Calibration model of the SPR experimental result with 1120 nm as initial resonance wavelength --- p.145
Appendix C Matlabrogram written for data analysis and simulation --- p.146
Appendix D Detail specification of the monochromator using in our laboratory --- p.150
Appendix E Monochromator Controlrogram --- p.156
Appendix F The throughput example copied from the handbook of ORIEL Instruments --- p.165
Appendix G RMSEPlot of the data obtained by self-established spectrometer with and without datare-treatments --- p.166
"Appendix H RMSEPlot of the raw data obtained from the three different commercial machines (Vector-22N/C, NIRSystem 6500 and NIRSystem XDS) with and without datare-treatment" --- p.176

The thermal denaturation of proteins has been extensively studied using several methods including differential scanning calorimetry (DSC). A custom-built optical system was used to study thermal effects on protein as an alternative method to DSC measurements. It was used to investigate the thermal stability of bovine serum albumin (BSA) with a focus on comparisons with published DSC data. In the first study, the effect of protein concentration on the thermal denaturation (Td) of BSA was determined and validated using published DSC data for bovine serum albumin (BSA). The optical rotation (OR) and transmitted light (TL) signals indicating protein conformational changes and gel formation, respectively, were collected during the heating of BSA solutions at ~6��C/min from room temperature to ~85��C. The experiments were performed on 1, 2.5 and 5% (w/v) BSA in 0.01 M phosphate buffer at pH 7 and ionic strength (IS) 0.08. BSA���s Td values obtained from this investigation were consistent with published values and had low experimental variability (CV<2.5%). In agreement with some but not all published data, increasing BSA concentration did not affect its thermal stability. Protein gel formation, however, increased with protein concentration. In the second study, changes in the OR and TL signal of BSA in 0.01 M phosphate buffer at pH 6.1, 7 and 7.9 with IS maintained at 0.04, 0.08 and 0.16 were recorded during the heating of BSA solutions at ~6��C/min from room temperature to ~85��C. BSA showed a maximum and minimum thermostability at pH 7 and 7.9, respectively, consistent with published values determined by DSC. BSA formed opaque gel at pH 6.1 approaching the BSA���s pI values. Increasing IS level did not have a significant effect on BSA���s Td value but promoted gel formation. In the third study, the optical method was applied to investigate the heat stability of BSA as affected by low concentrations of sucrose, trehalose or sorbitol. BSA solutions (2.5% w/v) in the presence of 0 5% sucrose, trehalose and sorbitol were heated at ~6��C/min from ambient temperature to ~85��C. In contrast with published work on the thermal stability of BSA in the presence of higher sugar concentrations, this study showed that increasing sugar concentration did not enhance the thermal stability of this protein. Also, the ability to promote protein stability among sucrose, trehalose and sorbitol were not significantly different. The significance of these studies is that they demonstrate that the custom-built optical methods here developed can be used to study heat-induced protein denaturation and the effect of environmental conditions. Future studies will examine other proteins such as ��-lactoglobulin or ��-lacactalbumin. A further advantage of optical systems is their ability to conduct real-time measurements which could be used for food processing control.
Graduation date: 2007

Plant nectar is a simple food and is easily digested by many different species of pollinators. Many compounds make up the composition of floral nectars, but the most abundant are sugars, generally dominated by sucrose and the hexoses, glucose and fructose. Nectar sugars have been measured for many plant species visited by hummingbirds, sunbirds and other passerines, revealing a range of concentrations. The nectars of passerine-pollinated flowers are generally dilute compared to those of bee-pollinated flowers. The question why bird nectars are so dilute has been addressed in many studies. Many hypotheses have been proposed, among them the relationship between viscosity and drinking by birds. The viscosity of sugar solutions increases exponentially with increasing concentration, and capillarity is inversely proportional to viscosity. Nectarivorous birds imbibe nectar by capillarity, and high sugar concentrations could impose constraints on their feeding efficiency. Feeding in nectarivorous birds, especially hummingbirds, has been mostly devoted to assessing sugar type preferences. However, concentration preferences have received less attention, and the effect of viscosity on feeding has not been examined separately from sugar concentration for any bird species. Do nectarivorous birds show a preference for specific concentrations at a broad and a fine scale of difference, given a specific sugar type? Does viscosity impose a feeding limitation on nectarivorous birds? Does it affect their feeding behaviour? Sunbirds and other nectar-feeding birds can choose amongst various flowering plant species at any one time. Their feeding responses may have important consequences on pollination ecology. In this study, concentration preferences of white-bellied sunbirds were examined using paired solutions of either sucrose or equicaloric 1:1 mixtures of glucose and fructose, at a both a broad and a fine scale of difference between pairs over the concentration range of 0.25 to 2.5 M. I hypothesized that sunbirds would prefer concentrations of 1 M and higher on sucrose solutions, while preferring concentrations less than 1 M on hexose solutions. On both sugar types at the broad scale, the higher concentration was significantly preferred up to 1 M, suggesting a preference for 1 M sugar solutions. At a finer scale, white-bellied sunbirds were able to discriminate 0.03 and 0.05 M (1 and 2% w/w) concentration differences between sucrose and hexose solutions respectively. This discrimination is similar to that reported at low concentrations for other passerine nectar-feeders, and at higher concentrations for hummingbirds. To determine if high viscosity nectars limit the sugar intake of avian nectar consumers, white-bellied sunbirds were exposed to three different test series of sucrose solutions: control series (CS, pure sucrose 0.25 – 2.5 M), constant viscosity series (CVS, 0.25 – 0.7 M with increased viscosity equivalent to that of 1 M sucrose) and constant concentration series (CCS, 1 M with increased viscosities equivalent to that of 1.5, 2 and 2.5 M sucrose). Viscosities were artificially altered with Tylose®. The sunbirds had reduced intake rates and gained less energy on more viscous sucrose solutions. Also, sunbirds did not alter their feeding behaviour (feeding frequency, feeding duration, total feeding duration and feeding interval) in any significant way when feeding on more viscous sucrose solutions. This lack of change in feeding behaviour led to lower sugar intake rates and sugar consumption. These results suggest that sunbirds suffer a preingestional limitation when consuming nectars with viscosities higher than those due to sugar concentration alone.
Dissertation (MSc)--University of Pretoria, 2010.
Zoology and Entomology
unrestricted

碩士
國立中興大學
生物產業機電工程學系
92
Plant tissue culture is one of important industry in the biotechnology. The application of plant tissue culture can breed the good plants and modifies some hereditary feature by sieving out some mutants of quality. In the tissue culture work adequate medium is very important. Sugar is important component in medium. It is the main source of carbon in the tissue culture plantlet. The purpose of this study was to apply the time-domain reflectometer(TDR) technology to measure the sugar concentration in the tissue culture medium. The technology may be used to monitor the processing of tissue culture, that is, to obtain the sugar of consumption during growth stages. Then the consumption curve of sugar could be obtained in the culture of process. In the study, a novel probe designed by researcher and combine with TDR was applied in the tissue culture vessel. The results of this study indicated that the concentrations of glucose and sucrose in the tissue culture medium could be measured. At the same terms, these curves between two kinds of sugar were not significant difference. The measurement of concentration of sugar that is not easy to for whole curves. One section of waveform was picked and treat by regression analyze technology. The correlations between concentration and regression coefficient were established. The experience equation to incorporate the temperature term was executed. So the TDR signal can be used to estimate concentration of sugar. As MS formula was added into medium, much ions of conductivity interference the dielectric of measurement. The TDR technique was inadequate to be applied to the medium with MS composition.

碩士
國立臺灣大學
森林學研究所
87
Summary In this research，we want to realize the effects of dalapon on concentration of amino acids and sugars in leaves of green bamboo（Bambusa oldhami Munro）. In October 1998. two culms of green bamboo were selected in Taita campus and were treated with 0 g、1g and 5g dalapon respectively. After that，in each month，leaves from each culms were collected，and used to analyse the amounts total sugars，reducing sugars and total amino acids. It was found that total sugars and reducing sugars decreased；but total amino acids increased. After dalapon treatment on October 1998 as described ，leaves of green bambo were collected on November 1998， January 1999，and March 1999，The content of individual amino acids and amide in these leaves by an automatic amino acid analyzer. It was found that each amino acid or amide increased after dalapon treatment. Among them ,giutarmic acid and aspartic acid increased tremendously in leaves of 5g dalapon treated bambo which were collected after 6 months of treatment.

碩士
美和科技大學
健康與生技產業研究所
101
Wax apple is an important economic fruit crop and‘Pink’ is the leading cultivar in Taiwan. Although the fruit of ‘Pink’ can be quite large, flesh thick, sweet and juicy, fruit skins are sometimes not able to reach the expected crimson color, especially in the late spring to late summer high temperature period.‘Thub Thim Chan’ is a red colored cultivar imported from Thailand. Although the quality of its fruit is inferior to that of the ‘Pink’, its skin color remains crimson even in summer. The present study investigated the effects of temperature, sugar concentration and light intensity on the fruit growth and anthocyanin biosynthesis of‘Thub Thim Chan’. The results show that anthocyanin concentration is three times greater under 300 μmole m-2 s-1 light intensity than that of the dark. Fruit skin color is the best at 20℃ than 25℃ and 30℃. Sucrose at 9% gives the best fruit skin color. To realize the effects of culture length, f ruit skin discs were cultured at 20℃or 25℃for from 2 to 14 days. The results showed that either weight, diameter or the anthocyanin concentration was at their peak on the 14th day under 20℃. While 25℃ treatment reaches the highest weight, diameter, sugar concentration and anthocyanin concentration on the 12th day.To understand the effects of temperature shift on fruit growth of ‘Thub Thim Chan’ and ‘Pink’, fruit discs were first cultured at 20℃ for 3, 6, 9 and 12 days, and then 11, 8, 5 and 2 days at 30℃. The results showed that weight and sugar content of ‘Thub Thim Chan’ wax apple fruit discs were bether for the 20℃ 3d → 30℃ 11d, 20℃ 6d → 30℃ 8d and 20℃ 9d → 30℃ 5d treatments. 20℃ 12d → 30℃ 2d gives better fruit skin coloring. Although temperature shifting did not affect the weight and diameterof ‘Pink’ wax apple fruit discs, sugar concentrations was greater for the 20℃ 6d → 30℃ 8d and 20℃ 9d → 30℃ 5d Treatments. Anthocyanin concentrations were higher for the 20℃ 9d → 30℃ 5d and 20℃ 12d → 30℃ 2d treatments.The effects of high temperatures on the quality of ‘Thub Thim Chan’ wax apple fruits was studied using simulated high temperatures (30℃, 35℃ and 40℃) in the field. The results showed that 40℃ treated either 10 days, 20 days or 26 days resulted in the lightest fruit weigt, shortest diameter, the lowest concentration of anthocyanins.