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  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 426 journals)
Showing 1 - 200 of 265 Journals sorted alphabetically
AAS Open Research     Open Access   (Followers: 1)
ABC Journal of Advanced Research     Open Access  
Accountability in Research: Policies and Quality Assurance     Hybrid Journal   (Followers: 22)
Acta Materialia Transilvanica     Open Access  
Acta Nova     Open Access   (Followers: 1)
Acta Scientifica Malaysia     Open Access  
Acta Scientifica Naturalis     Open Access   (Followers: 3)
Adıyaman University Journal of Science     Open Access  
Advanced Science     Open Access   (Followers: 13)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 11)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 5)
Advances in Research     Open Access  
Advances in Science and Technology     Full-text available via subscription   (Followers: 17)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 8)
Afrique Science : Revue Internationale des Sciences et Technologie     Open Access   (Followers: 2)
AFRREV STECH : An International Journal of Science and Technology     Open Access   (Followers: 4)
American Academic & Scholarly Research Journal     Open Access   (Followers: 6)
American Journal of Applied Sciences     Open Access   (Followers: 27)
American Journal of Humanities and Social Sciences     Open Access   (Followers: 17)
American Scientist     Full-text available via subscription   (Followers: 13)
ANALES de la Universidad Central del Ecuador     Open Access   (Followers: 4)
Anales del Instituto de la Patagonia     Open Access  
Applied Mathematics and Nonlinear Sciences     Open Access   (Followers: 1)
Apuntes de Ciencia & Sociedad     Open Access  
Arab Journal of Basic and Applied Sciences     Open Access  
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives Internationales d'Histoire des Sciences     Partially Free   (Followers: 7)
Archives of Current Research International     Open Access  
ARO. The Scientific Journal of Koya University     Open Access   (Followers: 1)
ARPHA Conference Abstracts     Open Access   (Followers: 5)
ARPHA Proceedings     Open Access   (Followers: 5)
ArtefaCToS : Revista de estudios sobre la ciencia y la tecnología     Open Access   (Followers: 1)
Asia-Pacific Journal of Science and Technology     Open Access  
Asian Journal of Advanced Research and Reports     Open Access   (Followers: 2)
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 2)
Asian Journal of Scientific Research     Open Access   (Followers: 3)
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 7)
Australian Field Ornithology     Full-text available via subscription   (Followers: 4)
Australian Journal of Social Issues     Hybrid Journal   (Followers: 7)
Avrasya Terim Dergisi     Open Access  
Bangladesh Journal of Scientific Research     Open Access   (Followers: 1)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 3)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10)
Berkeley Scientific Journal     Full-text available via subscription  
BIBECHANA     Open Access   (Followers: 2)
BibNum     Open Access  
Bilge International Journal of Science and Technology Research     Open Access   (Followers: 1)
Bioethics Research Notes     Full-text available via subscription   (Followers: 16)
Bistua : Revista de la Facultad de Ciencias Básicas     Open Access  
BJHS Themes     Open Access   (Followers: 1)
Black Sea Journal of Engineering and Science     Open Access  
Borneo Journal of Resource Science and Technology     Open Access  
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Bulletin de la Société Royale des Sciences de Liège     Open Access  
Bulletin of the National Research Centre     Open Access  
Butlletí de la Institució Catalana d'Història Natural     Open Access  
Central European Journal of Clinical Research     Open Access  
Chain Reaction     Full-text available via subscription  
Ciencia & Natura     Open Access   (Followers: 1)
Ciencia Amazónica (Iquitos)     Open Access   (Followers: 1)
Ciencia en Desarrollo     Open Access   (Followers: 3)
Ciencia en su PC     Open Access   (Followers: 1)
Ciencia Ergo Sum     Open Access  
Ciência ET Praxis     Open Access  
Ciencia y Tecnología     Open Access  
Ciencia, Docencia y Tecnología     Open Access  
Ciencias Holguin     Open Access   (Followers: 2)
CienciaUAT     Open Access   (Followers: 1)
Citizen Science : Theory and Practice     Open Access   (Followers: 2)
Communications Faculty of Sciences University of Ankara Series A2-A3 Physical Sciences and Engineering     Open Access  
Communications in Applied Sciences     Open Access  
Comprehensive Therapy     Hybrid Journal   (Followers: 3)
Comunicata Scientiae     Open Access   (Followers: 1)
ConCiencia     Open Access  
Conference Papers in Science     Open Access   (Followers: 2)
Configurations     Full-text available via subscription   (Followers: 11)
COSMOS     Hybrid Journal   (Followers: 1)
Crea Ciencia Revista Científica     Open Access   (Followers: 2)
Cuadernos de Investigación UNED     Open Access  
Current Issues in Criminal Justice     Hybrid Journal   (Followers: 15)
Current Research in Geoscience     Open Access   (Followers: 8)
Dalat University Journal of Science     Open Access  
Data     Open Access   (Followers: 5)
Data Curation Profiles Directory     Open Access   (Followers: 5)
Dhaka University Journal of Science     Open Access  
Dharmakarya     Open Access  
Diálogos Interdisciplinares     Open Access  
Digithum     Open Access   (Followers: 2)
Discover Sustainability     Open Access   (Followers: 2)
Einstein (São Paulo)     Open Access  
Ekaia : EHUko Zientzia eta Teknologia aldizkaria     Open Access  
Elkawnie : Journal of Islamic Science and Technology     Open Access  
Emergent Scientist     Open Access  
Enhancing Learning in the Social Sciences     Open Access   (Followers: 9)
Enseñanza de las Ciencias : Revista de Investigación y Experiencias Didácticas     Open Access  
Entramado     Open Access  
Entre Ciencia e Ingeniería     Open Access   (Followers: 1)
Epiphany     Open Access   (Followers: 4)
Estação Científica (UNIFAP)     Open Access   (Followers: 1)
Ethiopian Journal of Education and Sciences     Open Access   (Followers: 6)
Ethiopian Journal of Science and Technology     Open Access  
Ethiopian Journal of Sciences and Sustainable Development     Open Access   (Followers: 5)
European Online Journal of Natural and Social Sciences     Open Access   (Followers: 12)
European Scientific Journal     Open Access   (Followers: 12)
Evidência - Ciência e Biotecnologia - Interdisciplinar     Open Access  
Exchanges : the Warwick Research Journal     Open Access   (Followers: 2)
Experimental Results     Open Access   (Followers: 1)
Extensionismo, Innovación y Transferencia Tecnológica     Open Access   (Followers: 3)
Facets     Open Access  
Fides et Ratio : Revista de Difusión Cultural y Científica     Open Access   (Followers: 1)
Fırat University Turkish Journal of Science & Technology     Open Access  
Fontanus     Open Access  
Forensic Science Policy & Management: An International Journal     Hybrid Journal   (Followers: 380)
Frontiers for Young Minds     Open Access  
Frontiers in Climate     Open Access   (Followers: 3)
Frontiers in Science     Open Access   (Followers: 1)
Fundamental Research     Open Access   (Followers: 2)
Futures & Foresight Science     Hybrid Journal   (Followers: 4)
Gaudium Sciendi     Open Access   (Followers: 1)
Gazi University Journal of Science     Open Access  
Ghana Studies     Full-text available via subscription   (Followers: 15)
Global Journal of Pure and Applied Sciences     Full-text available via subscription  
Global Journal of Science Frontier Research     Open Access   (Followers: 2)
Globe, The     Full-text available via subscription   (Followers: 4)
HardwareX     Open Access  
Heidelberger Jahrbücher Online     Open Access  
Heliyon     Open Access  
Himalayan Journal of Science and Technology     Open Access   (Followers: 1)
History of Science and Technology     Open Access   (Followers: 2)
Hoosier Science Teacher     Open Access  
Iberoamerican Journal of Science Measurement and Communication     Open Access  
Impact     Open Access   (Followers: 2)
Indian Journal of History of Science     Hybrid Journal   (Followers: 2)
Indonesian Journal of Fundamental Sciences     Open Access  
Indonesian Journal of Science and Mathematics Education     Open Access   (Followers: 4)
Indonesian Journal of Science and Technology     Open Access  
Ingenieria y Ciencia     Open Access   (Followers: 1)
Innovare : Revista de ciencia y tecnología     Open Access  
Instruments     Open Access  
Integrated Research Advances     Open Access  
Interciencia     Open Access   (Followers: 1)
Interface Focus     Full-text available via subscription  
International Annals of Science     Open Access  
International Archives of Science and Technology     Open Access  
International Journal of Academic Research in Business, Arts & Science     Open Access   (Followers: 2)
International Journal of Advanced Multidisciplinary Research and Review     Open Access  
International Journal of Applied Science     Open Access  
International Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
International Journal of Computational and Experimental Science and Engineering (IJCESEN)     Open Access  
International Journal of Culture and Modernity     Open Access   (Followers: 3)
International Journal of Engineering, Science and Technology     Open Access  
International Journal of Engineering, Technology and Natural Sciences     Open Access  
International Journal of Innovation and Applied Studies     Open Access   (Followers: 12)
International Journal of Innovative Research and Scientific Studies     Open Access   (Followers: 6)
International Journal of Network Science     Hybrid Journal   (Followers: 3)
International Journal of Recent Contributions from Engineering, Science & IT     Open Access   (Followers: 1)
International Journal of Research in Science     Open Access   (Followers: 2)
International Journal of Science & Emerging Technologies     Open Access   (Followers: 1)
International Journal of Social Sciences and Management     Open Access   (Followers: 3)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 7)
International Letters of Social and Humanistic Sciences     Open Access   (Followers: 1)
International Review of Applied Sciences     Open Access  
International Scientific and Vocational Studies Journal     Open Access   (Followers: 2)
InterSciencePlace     Open Access   (Followers: 1)
Investiga : TEC     Open Access  
Investigación Joven     Open Access  
Investigación Valdizana     Open Access  
Investigacion y Ciencia     Open Access   (Followers: 1)
Iranian Journal of Science and Technology, Transactions A : Science     Hybrid Journal  
iScience     Open Access   (Followers: 2)
Issues in Science & Technology     Free   (Followers: 7)
Ithaca : Viaggio nella Scienza     Open Access  
J : Multidisciplinary Scientific Journal     Open Access  
Jaunujų mokslininkų darbai     Open Access   (Followers: 1)
Journal de la Recherche Scientifique de l'Universite de Lome     Full-text available via subscription   (Followers: 2)
Journal of Chromatography & Separation Techniques     Open Access   (Followers: 12)
Journal of Advanced Research     Open Access   (Followers: 3)
Journal of Al-Qadisiyah for Pure Science     Open Access   (Followers: 1)
Journal of Alasmarya University     Open Access   (Followers: 3)
Journal of Analytical Science & Technology     Open Access   (Followers: 6)
Journal of Applied Science and Technology     Full-text available via subscription   (Followers: 1)
Journal of Applied Sciences and Environmental Management     Open Access   (Followers: 3)
Journal of Big History     Open Access   (Followers: 3)
Journal of Composites Science     Open Access   (Followers: 3)
Journal of Critical Thought and Praxis     Open Access   (Followers: 2)
Journal of Deliberative Mechanisms in Science     Open Access  
Journal of Diversity Management     Open Access   (Followers: 6)
Journal of Indian Council of Philosophical Research     Hybrid Journal  
Journal of Institute of Science and Technology     Open Access  
Journal of Integrated Science and Technology     Open Access  
Journal of Interaction Science     Open Access   (Followers: 1)
Journal of Kerbala University     Open Access   (Followers: 1)
Journal of King Saud University - Science     Open Access   (Followers: 1)
Journal of Mathematical and Fundamental Sciences     Open Access  
Journal of Natural Sciences and Mathematics Research     Open Access  
Journal of Natural Sciences Research     Open Access   (Followers: 4)
Journal of Negative and No Positive Results     Open Access  
Journal of Responsible Technology     Open Access   (Followers: 1)
Journal of Science (JSc)     Open Access  
Journal of Science and Engineering     Open Access  

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Revista de Ciencia y Tecnología
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ISSN (Print) 0329-8922 - ISSN (Online) 1851-7587
Published by SciELO Homepage  [799 journals]
  • Calidad fisica de un suelo bajo distintos usos y manejo

    • Abstract: O monitoramento da qualidade fisica e quimica do solo e importante para manter ou modificar o manejo incorreto do solo. Neste sentido, o objetivo deste trabalho foi avaliar as propriedades fisicas para monitorar a qualidade do solo em diferentes tipos de manejo. O delineamento experimental utilizado foi o inteiramente casualizado, com tres tratamentos: Area de vegetacao natural; Area com o cultivo de cultura perene e Area de pastagem degradada; com 5 repeticoes. Foram avaliadas as propriedades fisicas: densidade do solo, taxa de infiltracao de agua, resistencia do solo a penetracao e umidade gravimetrica do solo. nas camadas de solo: 0,00-0,10; 0,10-0,20 e 0,20-0,40m, respectivamente. Os dados foram analisados estatisticamente, utilizando o teste de Tukey a 5% para comparacao das medias. A resistencia a penetracao nao foi um bom indicador da qualidade do solo. Os resultados encontrados mostram que o manejo interfere na qualidade fisica do solo. Conclui-se que o tratamento vegetacao nativa apresenta melhor qualidade fisica do solo.Monitoreo de la calidad del suelo y la quimica fisica es importante para mantener o modificar la direccion incorrecta del suelo. En este sentido, el objetivo de este estudio fue evaluar las propiedades fisicas para controlar la calidad del suelo en diferentes tipos de gestion. El diseno experimental fue completamente al azar, con tres tratamientos: area de vegetacion natural; Area con cultivos perennes y zona de pastos decapitados; con 5 repeticiones. las propiedades fisicas se evaluaron: la densidad del suelo, la tasa de infiltracion de agua, resistencia a la penetracion del suelo y la humedad del suelo gravimetrico. en capas de suelo: 0.00 0,10; 0,10-0,20 y 0,20-0,40m, respectivamente. Los datos fueron analizados estadisticamente mediante la prueba de Tukey al 5% para la comparacion de medias. La resistencia a la penetracion no fue un buen indicador de la calidad del suelo. Los resultados muestran que la administracion interfiere con la calidad fisica del suelo. Llegamos a la conclusion de que el tratamiento vegetacion nativa ha mejorado la calidad del suelo.It is important to monitor the physical quality and soil chemistry to maintain or modify the incorrect soil management. In this sense, the objective of this study was to evaluate the physical properties to monitor soil quality in different types of management. The experimental design was completely randomized, with three treatments: natural vegetation area; area with perennial crop cultivation and degraded pasture area; with 5 replications. The following physical properties were evaluated: soil density, water infiltration rate, soil penetration resistance and gravimetric soil moisture, in soil depths: 0.00 to 0.10; 0,20-0,40m and 0.10-0.20, respectively. We analysed data statistically by using the 5% Tukey test for comparison of means. The penetration resistance was not a good indicator of soil quality. The results show that the management interferes with the soil physical quality. We conclude that the treatment has improved physical native vegetation soil quality.
       
  • Estudio del rendimiento de cultivares de frijol caupi (Vigna unguiculata
           (L.) Walp.) en diferentes epocas de siembra en Camajuani, Cuba

    • Abstract: La investigacion se desarrollo en el Huerto Intensivo de la Agricultura Urbana del municipio Camajuani, provincia Villa Clara, Cuba, sobre suelo pardo con carbonatos de fertilidad media-baja. El experimento evaluo los componentes del rendimiento en 4 cultivares de caupi y en 2 epocas de siembra. Se empleo un diseno en bloques al azar con 6 repeticiones. Los rendimientos de los 4 cultivares reafirmaron sus posibilidades como alimento humano y animal. El rendimiento en febrero-mayo resulto significativamente inferior al de junio-septiembre; las condiciones ambientales de escasa precipitacion de este ultimo ciclo explican este resultado. El cultivar testigo Vinales seguido del Guariba, de crecimiento determinado, tuvieron rendimiento significativamente superior a las de crecimiento indeterminado IPA-206 e IPA-207. El rendimiento en los 4 cultivares fue determinado por el componente del rendimiento numero de vainas, para todos los cultivares en la siembra de junio-septiembre.This study was conducted in the Intensive Orchard of the Urban Agriculture of the Municipality of Camajuani, province of Villa Clara, Cuba, on brown soils with carbonates of medium to low fertility. The experiment evaluated the yield components in 4 Cowpea cultivars and in 2 sowing times. A design was used in randomized blocks with 6 repetitions. The yields of all the 4 cultivars reaffirmed their possibilities as human and animal food. The yield of the period February-May was significantly lower than through June-September; the weather conditions of scarce precipitation in this last cycle explain this result. The witness cultivar Vinales, followed by Guariba cultivar of certain growth, had significantly superior yield than those of uncertain growth IPA-206 and IPA-207. The yield in the 4 cultivars was determined by the yield component number of sheaths, for all the cultivars in the sowing of the period June-September.
       
  • Vino de Agua de Coco: Evaluacion Fisico-Quimica y Sensorial

    • Abstract: The physicochemical and sensory characteristics of a wine produced with coconut water were evaluated. The fermentation was conducted with Saccharomyces cerevisiae at 25 °C for 30 days. Titratable acidity, volatile and fixed acidity, pH, reducing sugars, sucrose content, density, alcohol content, yield and sensory analysis were determined. During the fermentation, titratable acidity increased from 33.56 to 63.53 meq/L and the pH decreased from 4.80 to 3.61. The coconut water wine had 5.25 meq/L of volatile acidity and 58.27 meq/L of fixed acidity. The reducing sugars were of 63.0 g/L and the sucrose content was 129.83 g/L. The alcohol content was 11.30°GL. The density reduced from 1.6870 (must) to 1.0197. The wine meets standards established by Brazilian law and yield was 77.75%. The product was well-accepted, being a potential product for commercialization.Se evaluaron las caracteristicas fisico-quimicas y sensoriales de vino de agua de coco. La fermentacion se realizo con Saccharomyces cerevisiae a 25 °C durante 30 dias. Se hicieron las determinaciones de acidez titulable, acidez volatil y fija, pH, azucares reductores, sacarosa, densidad, contenido de alcohol, rendimiento y analisis sensorial. Durante la fermentacion, la acidez aumento de 33,56 a 63,53 mEq/L y el pH disminuyo de 4,80 a 3,61. El vino de agua de coco tuvo 5,25 mEq/L de acidez volatil y 58,27 mEq/L de acidez fija. La concentracion de azucares reductores fue de 63,0 g/L y el contenido de sacarosa fue 129,83 g/L. El contenido de alcohol fue 11.30 °GL. La densidad se redujo de 1,6870 a 1,0197. El vino producido esta conformidad con las normas establecidas por la legislacion brasilena y su rendimiento fue del 77,75%. El producto tuvo buena aceptacion sensorial, siendo un producto con potencial de comercializacion.
       
  • Desarrollo y evaluacion sensorial de nectar mixto de pina y te Verde

    • Abstract: A elaboracao de nectares mistos fornece aos consumidores novos sabores e tem sido uma tendencia do mercado nacional e internacional. O objetivo deste estudo foi testar formulacoes de nectar misto de abacaxi e cha verde variando a proporcao polpa/cha, selecionado a melhor formulacao. Para a base mista do nectar foram utilizadas tres formulacoes: F1 (50% polpa/ 50% cha verde), F2 (60% polpa/ 40% cha verde) e F3 (70% polpa/ 30% cha verde). Os nectares foram elaborados com 30% da base mista e teor de solidos soluveis totais de 11 °Brix. Foram realizadas analises microbiologicas (coliformes a 35 °C e bolores e leveduras), fisico-quimicas (pH, acidez total e compostos fenolicos) e analise sensorial. A aceitacao sensorial foi conduzida com sessenta provadores nao treinados que avaliaram as formulacoes em relacao aos atributos cor, aparencia, aroma, sabor, docura, acidez, corpo e impressao global atraves de escala hedonica de 9 pontos. A atitude de compra do produto foi avaliada mediante escala de 5 pontos. Os resultados das analises microbiologicas foram satisfatorios, com ausencia de coliformes totais e bolores e leveduras. Os nectares mistos de abacaxi e cha verde obtiveram indice de aceitabilidade acima de 70% para cor, aparencia, corpo e impressao global. F2 foi a formulacao selecionada, uma vez que, teve aceitacao comparavel a F3. Assim, por F2 apresentar maior teor de cha verde que F3 e maior intencao de compra. Portanto, esta formulacao demonstra alto potencial para o mercado de nectares mistos.La produccion de nectares mixtos ofrece a los consumidores nuevos sabores y ha sido una tendencia en mercados nacionales e internacionales. El objetivo del estudio fue probar formulaciones de nectar mixto de pina y te verde cambiando la proporcion pulpa / te verde y seleccionar la mejor formulacion. En la base mixta se utilizaron tres formulaciones: F1 (50% de pulpa / 50% de te verde), F2 (60% de pulpa / 40% de te verde) y F3 (70% de pulpa / 30% de te verde). Los nectares se elaboraron con 30% de base mixta y contenido de solidos solubles totales fijos en 11 °Brix. Se realizaron analisis microbiologicos (coliformes a 35 °C, mohos y levaduras), fisico-quimicos (pH, acidez total y compuestos fenolicos) y analisis sensorial. La aceptacion sensorial se llevo a cabo con sesenta panelistas no entrenados que evaluaron las formulaciones para los atributos color, apariencia, aroma, sabor, dulzor, acidez, cuerpo e impresion global mediante escala hedonica de 9 puntos. La actitud de compra del producto se evaluo mediante una escala de 5 puntos. Los resultados de los analisis microbiologicos fueron satisfactorios, con la ausencia de coliformes totales, mohos y levaduras. Los nectares mixtos de pina y te verde mostraron indice de aceptabilidad por encima del 70% para color, apariencia, cuerpo e impresion global. F2 fue la formulacion seleccionada, pues tuvo aceptacion comparable a F3. Asi, por proporcionar F2 mayor contenido de te verde que F3 y tener la mayor intencion de compra, esta formulacion demuestra un alto potencial para el mercado de nectares mixtos.Mixed nectars production provides new flavors and it has been a trend of national and international markets. The aim of this study was to evaluate mixed nectar formulations of pineapple and green tea varying the ratio pulp/ tea, selecting the best one. For mixed base of nectar, three formulations were used: F1 (50% pulp/ 50% green tea), F2 (60% pulp/ 40% green tea) and F3 (70% pulp/ 30% green tea). Nectars were elaborated with 30% of the mixed base and total soluble solids content of 11 °Brix. Microbiological analyses (coliforms at 35 °C and molds and yeasts), physico-chemical analyses (pH, total acidity and phenolic compounds) and sensory analyses were made. Sensory acceptance was conducted with sixty untrained individuals that evaluated color, appearance, smell, flavor, sweetness, acidity, body and overall impression attributes using a 9 point hedonic scale. The purchase intention was also evaluated by using a 5-point scale. The results of the microbiological analyses were satisfactory, with the absence of total coliforms, molds and yeasts. Pineapple and green tea mixed nectars showed acceptability index above 70% for color, appearance, body and overall impression. F2 formulation was selected, since it had acceptance comparable to F3. F2 has greater green tea content than F3 and greater purchase intent too. Therefore, this formulation demonstrates high potential for mixed nectars market.
       
  • La produccion de bio-aceite a partir de diferentes materias primas en
           Brasil

    • Abstract: A tecnologia de pirolise e considerada promissora para conversao de biomassa celulosica. E esta revisao fornece uma visao geral de producao de bio-oleo a partir de pirolise e as possibilidades de empregabilidade comercial no Brasil. Retratando metodos de producao, modernizacao, alem da producao de insumos, como: o mercado madeireiro, a geracao de residuos agropecuarios e de residuos urbanos, que podem incrementar a producao energetica nacional, sem inferir na competicao por area e emissao de poluentes.La pirolisis se considera tecnologia prometedora para la conversion de biomasa celulosica. Y esta revision proporciona una vision general de la bio-aceite de pirolisis y de empleo comercial oportunidades en Brasil. Retratando metodos de produccion, la modernizacion, asi como los insumos de produccion, como el mercado de la madera, la generacion de residuos agricolas y residuos municipales, que puede construir la produccion nacional de energia sin inferir en la competencia por el area y las emisiones.Pyrolysis is considered promising technology for converting cellulosic biomass. This review provides an overview of pyrolysis bio-oil and its commercial use opportunities in Brazil. Portraying production methods, modernization, as well as production supplies, such as the timber market, the generation of agricultural waste and municipal waste can build national energy production without interfering in the competition for area and emissions.
       
  • Retencion de Sales de Boro en Tres Maderas Mexicanas: Evaluacion Mecanica
           por Vibraciones

    • Abstract: El objetivo de la investigacion fue determinar la densidad y el modulo de elasticidad de madera de Guazuma ulmifolia, Spathodea campanulata y Abies religiosa y observar el efecto del proceso de impregnacion con sales de boro sobre estas propiedades. Se estudiaron lotes de 35 probetas normalizadas y se impregnaron con una solucion con una concentracion del 3% con el metodo baño caliente-frio. Antes y despues del tratamiento de impregnacion se realizaron pruebas de vibraciones. Los valores promedio de la densidad, frecuencia natural y modulo de elasticidad son proporcionales a los reportados para maderas mexicanas. Cuantitativamente, los resultados de retencion son comparables con los de la bibliografia. Considerando que las tres especies fueron sometidas al mismo tratamiento de impregnado y probadas con un metodo de caracter no destructivo, se concluye que cada especie de madera responde mecanicamente de manera diferente e independiente al proceso de impregnacion con sales de boro.The aim of the research was to determine the density and the elasticity modulus of Guazuma ulmifolia, Spathodea campanulata and Abies religiosa wood and to observe the effect produced by a boron salts impregnation process on these properties. Thirty-five sets of standard specimens were studied, and impregnated with a 3% concentration solution with a hot-cold bath method. Before and after the treatment, transversal vibration tests were realized. Average values of density, natural frequency and elasticity modulus are proportional to Mexican woods previously reported. Quantitatively, results of boron salts retention were comparable with the ones reports in the bibliography. Considering that the three species were exposed to the same treatment of impregnation and tested with a nondestructive method, the research concluded that each wood species mechanically reacts in a different and independent way to the process of impregnation of Boron salts.
       
  • Produccion de bioetanol a partir de cultivos contaminados: una alternativa
           para salvar las cosechas dañadas

    • Abstract: El presente trabajo evalua la influencia presentada por el contenido de fumonisinas en maiz utilizado como materia prima para la produccion de bioetanol. Mediante experimentos de fermentacion a escala laboratorio, a partir de maiz con concentraciones crecientes de fumonisinas, se comparan tres parametros basicos del proceso de fermentacion (eficiencia, productividad y rendimiento) y se contrastan la concentracion final de etanol producido y el contenido inicial de almidon en la materia prima. Para valores de 0 y 1.400 ppm de fumonisinas en maiz, la concentracion promedio de etanol producido fue de 6,05% (p/p) y de 3,23% (p/p), respectivamente. Asi tambien, los tres parametros analizados disminuyeron al aumentar el nivel de contaminacion. Los resultados obtenidos demostraron que el maiz contaminado con fumonisinas puede ser utilizado como materia prima para la produccion de etanol en fermentaciones convencionales, siendo razonable utilizarlo hasta un nivel de contaminacion que no supere las 140 ppm de fumonisinas.In this study, we evaluate the influence exerted by the presence of fumonisins in corn used as feedstock for the production of bioethanol. With fermentation experiments at laboratory scale, using corn with increasing concentrations of fumonisin as raw material, three basic parameters of the fermentation process (efficiency, productivity and performance) are compared and the final concentration of ethanol and initial starch content in the raw material are contrasted. For values of 0 and 1,400 ppm of fumonisins in corn, the average concentration of ethanol produced was 6.05% (w/w) and 3.23% (w/w), respectively. In addition, the three parameters analyzed decreased with increasing contamination level. The results showed that corn contaminated with fumonisin could be used as feedstock for ethanol production in conventional fermentation processes, being reasonable to use it up to a concentration not exceeding 140 ppm fumonisin.
       
  • Estimacion del impacto economico de la sequia agricola en el cultivo de
           maiz

    • Abstract: Se realiza una investigacion para determinar el impacto economico que provoca la sequia agricola en el cultivo de maiz en el municipio Venezuela. Se establecen tres escenarios de precipitaciones: seco, normal y lluvioso, asi como los niveles de impactos (bajo, medio y alto) a los que puede estar sometido el cultivo en condiciones de secano. En la investigacion se emplea la matriz de riesgo como herramienta fundamental para la determinacion de perdidas y ganancias financieras, teniendo en cuenta la planificacion de siembra y el ciclo fenologico. Los resultados demostraron que es posible predecir los beneficios y perdidas economicas segun los escenarios definidos y obtener producciones de maiz bajo estas condiciones para los escenarios normales y lluviosos con buenos beneficios brutos.An investigation was conducted to determine the economic impact caused by agricultural drought in maize cultivation in the municipality of Venezuela. Three precipitation scenarios were established: dry, normal and rainy as well as their respective level of impacts (low, medium and high) that the crop can be subjected to under rainfed conditions. In this research, a risk matrix method was used as a fundamental tool for determining financial gains and losses, considering seeding planning and the phenological cycle. The results showed that it is possible to predict the benefits and economic losses from defined scenarios and get corn yields under these conditions for normal and rainy scenarios with good gross profits.
       
  • Estudio comparativo: secado de yerba mate con leña de bosque
           implantado vs chip de madera

    • Abstract: En cumplimiento de la normativa vigente en la provincia de Misiones, las industrias yerbateras han sustituido en sus procesos el uso de lena de bosque nativo por lena de bosque implantado y en menor medida por chip de madera del mismo origen. Cada tipo de combustible tiene una tecnologia especifica de quemado. In compliance with current regulations in the province of Misiones, the yerba mate industries have substituted in their processes the use of native forest firewood by implanted forest firewood and to a lesser extent by wood chip of the same origin. Each type has a specific fuel burning technology. El objetivo del presente trabajo fue comparar los dos metodos de secado, para evaluar la incidencia de cada uno sobre los parametros de calidad del producto final y la eficiencia economica del proceso. Se han encontrado diferencias significativas en las propiedades fisicoquimicas al comparar los metodos utilizados. Se determino en muestras procesadas con chip menor dispersion de valores de cada variable fisicoquimica. Los costos de produccion se redujeron un 29,73% respecto de la lena de bosque implantado. Se determino que con chip se logra un producto con mejores atributos de calidad y procesos productivos economicamente mas eficientes.In compliance with the regulations in force in the province of Misiones, the yerba mate industries have replaced their processes using native wood for firewood planted forest and to a lesser extent chip of wood of the same origin. Each type has a specific fuel burning technology. In compliance with current regulations in the province of Misiones, the yerba mate industries have substituted in their processes the use of native forest firewood by implanted forest firewood and to a lesser extent by wood chip of the same origin. Each type has a specific fuel burning technology. The aim of this study was to compare the two methods of drying, to assess the impact of each on the parameters of product quality and economic efficiency of the process. We found significant differences in physicochemical properties by comparing the methods used. It was determined less dispersion of values of each physicochemical variable in samples processed with chip. Production costs were reduced by 29.73% compared to forest firewood. It was determined that with chip a product of better quality and more efficient economically productive processes is achieved.
       
  • Aplicacion de diferentes tecnicas de Secado en frutas de Diospyros kaki
           var. ‘Fuyu’

    • Abstract: El objetivo fue evaluar el efecto de las condiciones de deshidratacion sobre la perdida de agua y los cambios de color en Dyospiros kaki var ‘Fuyu’. Las condiciones fueron: i) Secado con aire a velocidad (1,1 m/s) y temperatura (45, 60 y 75 .C) constantes (SAC), ii) Secado intermitente con ciclos de flujo de aire/reposo de 45/45 minutos (SAC INT), a las mismas temperaturas, iii) Deshidratacion osmotica en solucion de sacarosa a 50 y 60 .Brix y secado con aire a 60 .C (DO+SAC). El modelo de Page fue utilizado para describir la perdida de agua. Los valores de n para SAC a 45 y 60 .C, SAC INT y DO+SAC no presentaron diferencias significativas (p>0,05). Los valores de k aumentaron con la temperatura en SAC y SAC INT. Los parametros L* y b* disminuyeron durante el secado. El ΔE no fue afectado por el SAC INT.The aim of this study was to evaluate the effect of drying conditions on water loss and color changes of Diospyros kaki var Fuyu fruit. The conditions were: i) drying with constant air flow rate (1,1 m/s) and temperature (45, 60 and 75 °C) (SAC), ii) intermittent drying with cicles of heat application/tempering time for 45/45 min (SAC INT), at the same temperatures, iii) Osmotic dehydration in sucrose solution at 50 and 60 °Brix before drying at 60 °C (DO + SAC). In order to describe the water loss the Page model was used. The n parameter values of SAC at 45 and 60 °C,SAC INT and DO + SAC were not significantly different (p> 0.05). The k values increased with temperature in SAC and SAC INT. L* and b* color parameters decreased during drying. The color difference ΔE was not affected by INT SAC.
       
 
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