• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 125
  • 25
  • 10
  • 6
  • 6
  • 4
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 188
  • 104
  • 50
  • 48
  • 46
  • 38
  • 37
  • 29
  • 24
  • 20
  • 19
  • 17
  • 16
  • 15
  • 14
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A study of Jatropha cardiophylla

Bertino, Margaret Marion January 1932 (has links)
No description available.
2

Variabilidad morfológica en poblaciones de Jatropha curcas L. "piñón blanco" (Euphorbiaceae)

Machahua González, Miguel January 2010 (has links)
Se analiza la variabilidad morfológica de Jatropha curcas en 20 poblaciones cultivadas en las regiones de Lambayeque, Piura, Tumbes, San Martín y Ucayali. Se muestrearon 123 individuos de 2-4 cm de dap; se registraron ocho parámetros morfométricos como: altura total de la planta, número de ramas de la planta, número de lóbulos del limbo, longitud del limbo, del pecíolo, del fruto, largo y ancho de la semilla. Los parámetros fueron analizados mediante la prueba de comparaciones de medias ANOVA (p menor 0.05); a los que mostraron diferencias significativas se realiza el análisis de componentes principales. Existen diferencias significativas de seis parámetros entre las poblaciones; respecto a la altura total de la planta, el mayor valor se registra para la población de La Libertad, y el menor valor para la población de San Isidro; respecto a la cantidad de ramas, el mayor valor se registra para Olmos, y el menor valor para Chazuta; respecto a la longitud del limbo y el pecíolo, el mayor valor se registra para Tambo Grande, y el menor valor para Olmos; respecto a la cantidad de lóbulos, el mayor valor se registra para Tambo Grande, y el menor valor para Curimaná; respecto a la longitud del fruto, el mayor valor se registra para la población de Oidor y el menor valor en la población Yarinacocha. Los resultados del Análisis de Componentes Principales mostraron que el 66.9% de la varianza correspondió a los 2 primeros componentes. No se observaron grupos claramente definidos; sin embargo, las poblaciones de la región costera formaron grupos distintos con respecto a las poblaciones de la región amazónica. Palabras Claves: piñón blanco, morfometría, análisis de varianza, análisis de componentes principales. / --- We analyzed the morphological variation of Jatropha curcas in 20 populations grown in the regions of Lambayeque, Piura, Tumbes, San Martin and Ucayali. A total of 123 individuals with DBH 2-4 cm were sampled, eight morphometric parameters were evaluated such as total plant height, number of branches of the plant, number of lobes of the lamina, length of blade, petiole, fruit and seed. The parameters were analyzed by Paired t test ANOVA (p less than 0.05), those with significant differences were performed principal components analysis. There are significant differences among the populations in seven parameters; regarding the total plant height, the highest value recorded was in La Libertad, and the lowest value for the population of San Isidro; regarding the number of branches, the highest value recorded was in Olmos, and the lowest value for Chazuta; regarding the length of the blade and petiole, the highest value recorded was found in Tambo Grande, and the lowest value in Olmos, regarding the number of lobes, the highest value recorded was in Tambo Grande, and the lowest value in Curimaná; regarding the length of the fruit, the highest value recorded was found in Oidor and the lowest in the population Yarinacocha. The Principal Component Analysis showed that 70.9% of the variance corresponds to the two first components. Groups clearly defined were not observed; however, the populations of the coastal region formed groups distinct from those of the jungle region. Keywords: piñon blanco, morfometric, variance analysis, principal components analysis.
3

Variabilidad morfológica en poblaciones de Jatropha curcas L. "piñón blanco" (Euphorbiaceae)

Machahua González, Miguel January 2010 (has links)
Se analiza la variabilidad morfológica de Jatropha curcas en 20 poblaciones cultivadas en las regiones de Lambayeque, Piura, Tumbes, San Martín y Ucayali. Se muestrearon 123 individuos de 2-4 cm de dap; se registraron ocho parámetros morfométricos como: altura total de la planta, número de ramas de la planta, número de lóbulos del limbo, longitud del limbo, del pecíolo, del fruto, largo y ancho de la semilla. Los parámetros fueron analizados mediante la prueba de comparaciones de medias ANOVA (p menor 0.05); a los que mostraron diferencias significativas se realiza el análisis de componentes principales. Existen diferencias significativas de seis parámetros entre las poblaciones; respecto a la altura total de la planta, el mayor valor se registra para la población de La Libertad, y el menor valor para la población de San Isidro; respecto a la cantidad de ramas, el mayor valor se registra para Olmos, y el menor valor para Chazuta; respecto a la longitud del limbo y el pecíolo, el mayor valor se registra para Tambo Grande, y el menor valor para Olmos; respecto a la cantidad de lóbulos, el mayor valor se registra para Tambo Grande, y el menor valor para Curimaná; respecto a la longitud del fruto, el mayor valor se registra para la población de Oidor y el menor valor en la población Yarinacocha. Los resultados del Análisis de Componentes Principales mostraron que el 66.9% de la varianza correspondió a los 2 primeros componentes. No se observaron grupos claramente definidos; sin embargo, las poblaciones de la región costera formaron grupos distintos con respecto a las poblaciones de la región amazónica. Palabras Claves: piñón blanco, morfometría, análisis de varianza, análisis de componentes principales. / We analyzed the morphological variation of Jatropha curcas in 20 populations grown in the regions of Lambayeque, Piura, Tumbes, San Martin and Ucayali. A total of 123 individuals with DBH 2-4 cm were sampled, eight morphometric parameters were evaluated such as total plant height, number of branches of the plant, number of lobes of the lamina, length of blade, petiole, fruit and seed. The parameters were analyzed by Paired t test ANOVA (p less than 0.05), those with significant differences were performed principal components analysis. There are significant differences among the populations in seven parameters; regarding the total plant height, the highest value recorded was in La Libertad, and the lowest value for the population of San Isidro; regarding the number of branches, the highest value recorded was in Olmos, and the lowest value for Chazuta; regarding the length of the blade and petiole, the highest value recorded was found in Tambo Grande, and the lowest value in Olmos, regarding the number of lobes, the highest value recorded was in Tambo Grande, and the lowest value in Curimaná; regarding the length of the fruit, the highest value recorded was found in Oidor and the lowest in the population Yarinacocha. The Principal Component Analysis showed that 70.9% of the variance corresponds to the two first components. Groups clearly defined were not observed; however, the populations of the coastal region formed groups distinct from those of the jungle region. Keywords: piñon blanco, morfometric, variance analysis, principal components analysis.
4

Estudo Químico da raiz de Jatropha mollissima (Pohl) Baill; identificação de compostos fenólicos em quatro espécies do gênero Anthurium através de Cromatografia Líquida acoplada à Espectrometria de Massas. / Chemical study of the roots of Jatropha mollissima ( Pohl ) Baill; identification of phenolic compounds in four species of the genus Anthurium by Liquid Chromatography coupled to Mass Spectrometry.

Rios, Jeíson Barros January 2011 (has links)
RIOS, J. B. Estudo Químico da raiz de Jatropha mollissima (Pohl) Baill; identificação de compostos fenólicos em quatro espécies do gênero Anthurium através de Cromatografia Líquida acoplada à Espectrometria de Massas. 2011. 77 f. Dissertação (Mestrado em Química) - Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2011. / Submitted by Daniel Eduardo Alencar da Silva (dealencar.silva@gmail.com) on 2014-11-12T23:08:01Z No. of bitstreams: 1 2011_dis_jbrios.pdf: 898121 bytes, checksum: 89bff758a49488e2d8ad691148da961e (MD5) / Approved for entry into archive by José Jairo Viana de Sousa(jairo@ufc.br) on 2015-01-13T14:43:35Z (GMT) No. of bitstreams: 1 2011_dis_jbrios.pdf: 898121 bytes, checksum: 89bff758a49488e2d8ad691148da961e (MD5) / Made available in DSpace on 2015-01-13T14:43:35Z (GMT). No. of bitstreams: 1 2011_dis_jbrios.pdf: 898121 bytes, checksum: 89bff758a49488e2d8ad691148da961e (MD5) Previous issue date: 2011 / This work aimed to study the chemical from the root of Jatropha mollissima (Euphorbiaceae), a plant native to northeastern Brazil. In this study we used chromatographic techniques in an attempt to isolate the chemical constituents of hexane and ethanol extracts of the root. Chromatographic treatment of extract allowed the isolation of a long aliphatic chain alcohol called triacontanol, a mixture of the steroids B-sitosterol and stigmasterol and a terpene latirano skeleton called jatrogrossidiona. Also in this work, we investigated the composition of phenolic compounds present in methanol extracts of leaves of four species of the genus Anthurium using HPLC - MS in which it was possible to identify eight phenolic compounds: 6- C- arabinosyl -8- C- glycosyl - apigenin in the leaves of A. lindmanianum; 8-O-ramnosyl-( 1-3)-C-glycosyl - acacetin and 7-O-[6-O-acetylglicosyl(1-2)]ramnosyl-( 1-6 )-glycosyl - acacetin in the leaves of A. andraeanum, 5- caffeoylquinic acid, vitexin, isovitexin and Orientin in the leaves of A. bonplandii and 6- O-ramnosyl-( 1-3)-C-glycosyl-acacetin in the leaves of A. plowmanii. The results for the inhibition of acetylcholinesterase enzyme showed that only the hexane extract of J. mollissima and methanol extract from the leaves of A. andraeanum showed anticholinesterase activity. / O presente trabalho teve como objetivo o estudo químico da raiz de Jatropha mollissima (Euphorbiaceae), planta nativa do nordeste brasileiro. Nesse estudo utilizaram-se técnicas cromatográficas na tentativa de isolamento dos constituintes químicos dos extratos hexânico e etanólico da raiz. O tratamento cromatográfico do extrato hexânico possibilitou o isolamento de um álcool de cadeia alifática longa denominado triacontanol, uma mistura dos esteroides B-sitosterol e estigmasterol e um terpeno de esqueleto latirano denominado jatrogrossidiona. Ainda nesse trabalho, investigou-se a composição de compostos fenólicos presentes nos extratos metanólicos das folhas de quatro espécies do gênero Anthurium através de CLAE-EM onde foi possível a identificação de oito compostos fenólicos: 6-C-arabinosil-8-C-glicosil-apigenina nas folhas de A. lindmanianum; 8-O-ramnosil-(1-3)-C-glicosil-acacetina e 7-O-[6-O-acetilglicosil(1-2)]ramnosil-(1-6)-glicosil-acacetina nas folhas de A. andraeanum; ácido 5-cafeoilquínico, vitexina, isovitexina e orientina nas folhas de A. bonplandii e 6-O-ramnosil-(1-3)-C-glicosil-acacetina nas folhas de A. plowmanii. Os resultados para o teste de inibição da enzima acetilcolinesterase mostraram que apenas os extratos hexanico de J. mollissima e metanólico das folhas de A. andraeanum apresentaram atividade anticolinesterásica.
5

Estudo comparativo da cicatrização de gastrorrafias com e sem o uso do extrato bruto de Jatropha gossypiifolia L. em ratos

Vale, José de Ribamar 07 February 2013 (has links)
Resumo: Introdução: A cicatrização do trato gastrintestinal é de grande importância na história da cirurgia, buscando-se tipos de fios e pontos apropriados e os diversos fatores que a influenciam. O uso de fitoterápicos como aceleradores da cicatrização tem sido usado por muitos anos sendo objetivo atual de pesquisas para a comprovação científica dessas propriedades terapêuticas. Objetivo: avaliar o uso do extrato bruto de Jatropha gossypiifolia L. na cicatrização de gastrorrafias em ratos. Material e Método: Foram utilizados 40 ratos wistar, machos, divididos em 02 grupos de 20, denominados de grupos controle e Jatropha. Dez animais de cada grupo foram mortos no 3o dia pós-operatório e denominados subgrupos controle e Jatropha do 3o dia e os 10 restantes de cada grupo foram mortos no 7o dia com a mesma denominação do 7o dia. Em cada animal foi realizado gastrotomia e gastrorrafia em plano único com fio polipropileno 6-0 (prolene®). Os animais do grupo Jatropha receberam dose única de 200mg/Kg do extrato bruto de Jatropha gossypiifolia L via intraperitoneal no dia do procedimento e os do grupo controle a mesma quantidade em mililitros (ml) de solução salina (cloreto de sódio à 0,9%). Foram avaliados os seguintes parâmetros: 1) alterações macroscópicas; 2) a resistência à insuflação de ar atmosférico (pressão de ruptura) da sutura; 3) características histológicas. Resultados: Não houve morte dos animais na evolução clínica, havendo boa cicatrização da parede abdominal, na ausência de sinais de infecção, deiscência, abscessos ou peritonites. A cicatrização da superfície serosa foi considerada boa em todos os animais, não ocorrendo fístulas, porém, as aderências intra-peritoneais ocorreram em 7 ratos do subgrupo controle e 9 do subgrupo Jatropha do 3o dia pós-operatório e em 9 do subgrupo controle e 8 do subgrupo Jatropha do 7o dia, não havendo diferenças estatisticamente significantes entre os grupos. A cicatrização da superfície mucosa foi classificada como boa em todos os animais. A resistência das gastrorrafias à insuflação de ar atmosférico demonstrou aumento estatisticamente significante da pressão de ruptura no grupo Jatropha do 3o dia de observação. A avaliação histológica demonstrou diferenças estatisticamente significantes, quanto aos critérios, reação inflamatória aguda menor e coaptação das bordas maior no subgrupo Jatropha do 7o dia pós-operatório em relação ao grupo controle do mesmo período. Conclusão: Concluiu-se que o extrato bruto de Jatropha gossypiifolia L. favorece a cicatrização no 3o dia pós-operatório, em relação, a maior resistência das gastrorrafias à pressão de ruptura e no 7o dia com melhor coaptação das bordas e reduzindo reação inflamatória aguda à microscópica. Palavras-chave: ratos, gastrorrafias, Jatropha gossypiifolia L, cicatrização, teste de resistência à insuflação de ar atmosférico.
6

Estimación de la eficiencia del uso del agua (EUA) y Kdpv para plantas jóvenes de Jatropha Curcas L.

Parada Molina, Felipe Agustín January 2014 (has links)
Tesis para optar al grado de Magister en Ciencias Agropecuarias Manejo de Suelos y Aguas Memoria para optar al Título Profesional de Ingeniero Agrónomo / El interés por el cultivo de Jatropha curcas L. ha aumentado en los últimos años. Lo anterior producto de: (1) su potencial bioenergético, y; (2) su eficiencia en el uso del agua, permitiendo su uso en zonas de escasez hídrica. La información disponible sobre este último punto es contradictoria, por esta razón el objetivo de este trabajo fue determinar la eficiencia del uso del agua (EUA) y el coeficiente propuesto por Tanner y Sinclair (1983) (K DPV ) en plantas jóvenes de Jatropha curcas L. El ensayo se realizó en la Región de Coquimbo, Chile (30º13` S, 70º15` O), en plantas de un año. Tres frecuencias de riego fueron establecidas, cada: 8 (T1); 14 (T2), y; 24 días (T3), suministrando agua suficiente para dejar el suelo a capacidad de campo. Se cuantificó la cantidad de agua transpirada por la plantas mediante lisímetros de pesada, en los cuales se consideraron las variaciones de peso como la transpiración del cultivo. Se cuantificó la biomasa producida como materia seca, realizando cortes cada 24 días. Se recopiló la información climática necesaria para determinar el déficit de presión de vapor (DPV) y se realizaron mediciones de potencial hídrico xilemático a mediodía, y de crecimiento (altura, área de sección trasversal de tronco y número de hojas). Los valores obtenidos de EUA y K DPV para Jatropha curcas L. fueron de 4,30 g de materia seca (MS) por cada Mg de agua transpirada y 3,30 g de MS kPa kg -1 de agua transpirada, respectivamente. Jatropha curcas L. presentó valores de - 0,92 y - 0,65 MPa de potencial hídrico xilemático para el periodo más crítico de medición. Respecto a las variables de crecimiento no se encontraron diferencias significativas que respondiesen a los tratamientos aplicados, siendo el T2 el que mostro un mayor crecimiento dentro del presente ensayo en términos de todas las variables medidas. / The interest in Jatropha curcas L. cultivation has increased in the recent years. This is product of its: (1) bioenergy potential, and, (2) efficiency in water use, allowing its use in areas with water scarcity. The literature available on this last point is contradictory, therefore, the objective of this work was to determine the water use efficiency (WUE) and the coefficient proposed by Tanner and Sinclair (1983) (K DPV ) in young plants of Jatropha curcas L. The trial was conducted in the Region of Coquimbo, Chile (30°13'S, 70°15'O), with one year old plants. Three irrigation frequencies were established every: 8 (T1), 14 (T2), and, 24 days (T3), providing enough water to reach field capacity of soil. The amount of transpired water by plants was quantified through weight lysimeters in which the variations were considered as the transpiration of the crop. Produced biomass, in terms of dry matter (DM), was obtained by cutting the plants every 24 days. Weather information was collected to determine the vapor pressure deficit (VPD). The measurements of stem water potential were performed at noon, and growth parameters (as height, cross-sectional area of stem, and number of leaves) were also measured. The obtained values of WUE and K DPV for Jatropha curcas L. were 4.30 g of DM by each Mg of transpired water and 3.30 g of DM kPa kg -1 of transpired water, respectively. Jatropha curcas L. showed values of - 0.92 and - 0.65 MPa of stem water potential for the most critical period of measurement. Regarding growth variables, there was no significant differences observed in the applied treatments, however, the T2 treatment showed a higher growth than other treatments in all the variables measured.
7

Development and evaluation of an effective process for the recovery of oil and detoxification of meal from jatropha curcas

Gaur, Sarthak, January 2009 (has links) (PDF)
Thesis (M.S.)--Missouri University of Science and Technology, 2009. / Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed August 31, 2009) Includes bibliographical references (p. 51-56).
8

Jatropha Curcase in Oahu and Mozambique : Acknowledging scientific differences and resulting questions

Marshall, Lindsey January 2010 (has links)
In the current search for alternatives to fossil energy sources, scientists have expanded their biofuel research pools to include non-traditional crops. Plants that were once only thought of as food crops (for example rapeseed, maize, sugarcane, and sugar beet) are now experimented with and used for biofuel supply. Other plants that did not have any agricultural or commercial use are now integral parts of biofuel research and advancement. One of these plants, Jatropha curcas, has spread through the biofuel communities throughout the world. Jatropha curcas is noted for its high quality oil and ability to grow in poor conditions.  Most of the interest in this tree is concentrated in the tropics, where a year-round growing/harvest season is possible. This study was conducted in order to view and discuss Jatropha curcas in two different settings: two test fields at the Hawaiian Agricultural Research Centers on Oahu, Hawaii, and Sun Biofuels plantation in Chimoio, Mozambique. After visiting Oahu, it was clear that, although some significant steps in pruning techniques had been achieved, many of the questions surrounding jatropha remained unanswered. These questions included, but were not limited to: What is the ideal irrigation level? Is the plant close to domestication? How can optimal yield be achieved? Are there ways to avoid dormancy? Additionally, as a result of the research, many new questions regarding environmental, social, agricultural, and economic aspects of jatropha arose. In Chimoio, it became immediately apparent that the plantation was little more than a huge test plot at its current stage in August, 2009. There was no infrastructure being set-up or built either at Sun Biofuels or in the surrounding cities to accommodate for machine harvesting, crushing, pressing, storage, and transportation, even though the first harvest was scheduled for 2010. Additionally, there were no on-site engineers or scientists to help with the initial phases of growth and harvest. It was evident that jatropha was growing on good quality soil in both Hawaii and Mozambique, and jatropha crops were planted on previous agricultural land. Just because it was shown that jatropha could grow on poor quality land does not mean that it actually grows there in a plantation-like environment. Additionally, because it was been proven that jatropha can grow on good quality soil does not mean it is a competitive substitute for other biofuel crops. It is clear that jatropha has highly irregular qualities (for example, growth, seed content, oil content, oil properties) not just in different parts of the world or even in different plantations, but from genetically identical trees in the same plantation with the same growing conditions. This is an explanation for why jatropha data is so inconsistent across the world. Further scientific and engineering research must be put into jatropha before a company should embark on a large-scale plantation venture. / I dagens sökande efter alternativ till fossila energikällor har forskningen inom biobränsleområdet kommit att inkludera icke-traditionella grödor. Växter som tidigare bara var tänkta som livsmedelsgrödor (t.ex. raps, majs, sockerrör och sockerbetor) ingår idag i experiment och används inom biobränsleutbudet. Andra växter som tidigare inte haft något kommersiellt användningsområde är idag en integrerad del av biobränsleforskningen. En av dessa växter, trädet Jatropha curcas, har spridit sig inom biobränslesamhällen över hela världen. Jatropha är känd för sin högkvalitativa olja och sin förmåga att växa under förhållanden som skulle vara dåliga för andra grödor. Intresset för jatropha är koncentrerat till tropikerna, där skördesäsongen sträcker sig över hela året. Denna studie genomfördes för att undersöka och diskutera Jatropha curcas i två olika miljöer: på The Hawaiian Agricultural Research Center, Oahu, Hawaii samt på Sun Biofuels Plantation, Chimoio, Mozambique. Efter att ha besökt Oahu var det tydligt att även om vissa betydelsefulla framsteg inom beskärningsteknik hade uppnåtts, så är fortfarande många av frågorna kring jatropha obesvarade. Dessa frågor inkluderar, men är inte begränsade till: Vilken är den ideala bevattningsnivån? Kan växten domesticeras? Hur kan optimal avkastning uppnås? Finns det något sätt att undvika trädets naturliga viloperioder? Dessutom, som ett resultat av forskningen, har många nya frågor dykt upp, rörande miljömässiga, sociala, ekonomiska och jordbruksrelaterade effekter av jatrophaodling. I Chimoio blev det uppenbart att Sun Biofuels jatrophaodling, i augusti 2009, inte var mycket mer än en stor försöksanläggning. Ingen infrastruktur vid anläggningen eller i kringliggande städer var inrättad för att möjliggöra maskinell skördning, krossning, pressning, lagring och transportering – trots att första skörden var planerad redan till 2010. Dessutom fanns inga ingenjörer eller forskare på plats för att vara behjälpliga med de inledande faserna av tillväxt och skörd. Relevant data som har samlats in från de två besökta områdena, samt undersökt litteratur, presenteras i resultaten. Det är tydligt att jatropha har mycket varierande egenskaper med avseende på till exempel tillväxt, frönsättning, oljehalt samt oljans egenskaper; inte bara mellan olika delar av världen eller ens mellan olika planteringar, utan också från genetiskt identiska träd i samma plantering med samma odlingsförhållanden. Detta är en förklaring till varför data om jatropha från studier över hela världen är så inkonsekventa. De frågor som uppkom från både Oahu och Chimoio tas upp i diskussionen. Det är uppenbart att ytterligare vetenskaplig och teknisk forskning måste investeras i jatropha innan ett företag kan tänkas ta sig an en storskalig produktion. Det är uppenbart att de två undersökta plantagerna saknar såväl god vetenskaplig kunskap om jatropha som utrustning för dess hantering.
9

Optimization of Jatropha Oil Extraction and Its By-Product Utilization by Pyrolysis Method

Kongkasawan, Jinjuta 1987- 14 March 2013 (has links)
Since the price of fossil fuel has increased, petroleum resources have been restricted and the environmental effects have been of great concern. Biofuel has been considered to be a good solution because it is a clean, non-pollutant and a renewable energy. Biodiesel is one alternative energy that plays a major role in the energy industry. So, the development of biofuel process is more interesting. Jatropha curcas L. is considered as an alternative energy source in order to help solve the energy crisis. The purpose of this research is to investigate the optimum condition of Jatropha seed extraction via a screw press and its by-product utilization by a pyrolysis method for achieving the maximum mass conversion and energy recovery. In this study, Jatropha seeds were first extracted by a screw press with different discharge aperture sizes, namely, number 4 (4.0 mm), 8 (7.0 mm), and 10 (10.5 mm). The by-product obtained from a screw press was then performed pyrolysis runs at the operating temperatures of 400, 500, and 600 degrees C. Results revealed that the optimum condition was achieved when using discharge aperture number 8 (7.0 mm) for a screw press and performing the pyrolysis of the by- product at 500 degrees C. The mass conversion efficiency of 35.8% refined oil, 21.8% bio-char, 14.6% bio-oil, and 11.7% syn-gas were obtained. Therefore, the utilization of by-product using a pyrolysis can enhance the effectiveness of Jatropha oil extraction with only 16% mass losses occurred. In addition, the gross heating values of the products were observed as 39.6 MJ/kg for the refined oil, 35.1 MJ/kg for the bio-oil, 27.5 MJ/kg for the bio-char, and 2.1 MJ/kg for the syn-gas. Due to a high mass conversion efficiency and energy content of Jatropha products, Jatropha has the potential to serve as an alternative energy source.
10

Αξιολόγηση της καταλληλότητας ενεργειακών φυτών για καλλιέργεια στην Ελλάδα

Σαραβάκου, Δήμητρα 01 October 2014 (has links)
Τη σημερινή εποχή, η εξάντληση των αποθεμάτων των ορυκτών καυσίμων, σε συνδυασμό με τις αυξανόμενες ενεργειακές ανάγκες, οδήγησε στην παραγωγή των βιοκαυσίμων. Με αυτό τον όρο νοείται κάθε καύσιμο που παράγεται από βιομάζα. Ένα από τα δημοφιλέστερα βιοκαύσιμα στην Ευρώπη είναι το βιοντίζελ, το οποίο λαμβάνεται μετά από μετεστεροποίηση τριγλυκεριδίων που περιέχονται σε φυτικά έλαια και ζωικά λίπη. Οι λόγοι που οδήγησαν στην παραγωγή βιοντίζελ είναι περιβαλλοντικοί αλλά και οικονομικοί, καθώς η αύξηση της χρήσης των ορυκτών καυσίμων επιβάρυνε και συνεχίζει μέχρι σήμερα την ατμοσφαιρική ρύπανση αλλά και η αύξηση της τιμής του πετρελαίου δυσχεραίνει την οικονομική κατάσταση πολλών χωρών που εισάγουν ορυκτά καύσιμα. Στην παρούσα διπλωματική εργασία, παρουσιάζονται τα βιοκαύσιμα 1ης και 2ης γενιάς, οι πρώτες ύλες από τις οποίες προέρχονται, πως αξιοποιούνται, ποια είναι τα πλεονεκτήματα και τα μειονεκτήματα αυτών και στη συνέχεια δίνεται μεγαλύτερη έμφαση στο φυτό Jatropha curcas, το οποίο αποτελεί την πηγή για την παραγωγή βιοντίζελ 2ης γενιάς. Στο τρίτο κεφάλαιο αυτής της διπλωματικής εργασίας, γίνεται παρουσίαση του φυτού, ανάλυση των μορφολογικών χαρακτηριστικών του, περιγραφή της καλλιέργειάς του, των αναγκών του, αναφέρονται οι χώρες στις οποίες έχει διαδοθεί, ο τρόπος επεξεργασίας του, και οι χρήσεις του σε άλλες διεργασίες μέχρι σήμερα. Ακόμη γίνεται γνωστό το κόστος παραγωγής του, η απόδοσή του σε έλαιο και συγκρίνεται με τις βασικές πρώτες ύλες μέχρι στιγμής για την παραγωγή βιοντίζελ. Τέλος, αναφέρονται ευρωπαϊκά και παγκόσμια προγράμματα και πειράματα, στα οποία έχει μελετηθεί η απόδοσή του. / --

Page generated in 0.046 seconds