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Thermodynamic properties of water desorption in lettuce seeds | Propriedades termodinâmicas da dessorção de água de sementes de alface Texto completo
2018
Zeymer, Juliana Soares | Corrêa, Paulo Cesar | Oliveira, Gabriel Henrique Horta de | Baptestini, Fernanda Machado
Thermodynamic properties of water desorption in lettuce seeds | Propriedades termodinâmicas da dessorção de água de sementes de alface Texto completo
2018
Zeymer, Juliana Soares | Corrêa, Paulo Cesar | Oliveira, Gabriel Henrique Horta de | Baptestini, Fernanda Machado
Knowledge of the movement of water molecules inside material is important for the study of interactions between water and chemical components of agricultural products. The thermodynamic properties calculation reports this need, being the source of information to design drying equipment, calculate the energy required in this process and evaluate the physical phenomena that occur on the food surface. Given the importance of the subject, the objective of this study was to determine the thermodynamic properties of the water desorption process in lettuce seeds. Lettuce seeds had an initial moisture content of 9.3% (d.b.). The equilibrium moisture content of seeds was determined by static gravimetric method at different temperatures (10, 20, 30, 40 and 50 ± 1 °C) and relative humidity values (between 11 and 96%). Experiments were conducted in triplicate. It was observed that, with increasing equilibrium moisture content, there was a reduction in the energy required for evaporation of water in lettuce seeds, with values of integral isosteric heat of desorption in the water content range 2.1 to 21.2% (d.b.) which varied from '4164.89 to 2477.43' kJ kg-1. With increasing equilibrium moisture content there was a decrease in differential entropy, resulting in lower demand for mobility of water molecules. The Gibbs free energy also decreased with increasing equilibrium moisture content and was positive for all temperatures studied, showing non-spontaneity of water desorption in the seeds. The enthalpy-entropy compensation theory was has been satisfactorily applied to the sorption phenomenon and the water desorption process in lettuce seeds was controlled by enthalpy. | O conhecimento da movimentação das moléculas de água dentro do material é importante para o correto estudo das interações entre a água e os componentes químicos dos produtos agrícolas. O cálculo das propriedades termodinâmicas relata essa necessidade, sendo fonte de informação para projetar equipamentos de secagem, calcular a energia requerida nesse processo e avaliar os fenômenos físicos que ocorrem na superfície dos alimentos. Diante da importância do assunto, o objetivo do presente trabalho foi determinar as propriedades termodinâmicas do processo de dessorção de água em sementes de alface. As sementes de alface possuíam teor de água inicial de 9,3% (b.s.). O teor de água de equilíbrio das sementes foi determinado pelo método estático-gravimétrico para diferentes valores de temperatura (10, 20, 30, 40 e 50 ± 1 °C) e atividade de água (entre 11 e 96%), em três repetições. De acordo com os resultados encontrados, observou-se que com o aumento do teor de água de equilíbrio, ocorre redução da energia necessária para a evaporação da água nas sementes de alface, sendo que os valores do calor isostérico integral de dessorção, na faixa de teor de água de 2,1 a 21,2% (b.s.), variaram de 4164,89 a 2477,43 kJ kg-1. Com a elevação do teor de água de equilíbrio, há um decréscimo da entropia diferencial, implicando em menor demanda de mobilidade das moléculas de água. A energia livre de Gibbs também diminuiu com o incremento do teor de água de equilíbrio, sendo positiva para todas as temperaturas estudadas, demonstrando a não espontaneidade do processo de dessorção de água nas sementes. A teoria da compensação entalpia-entropia foi satisfatoriamente aplicada ao fenômeno de sorção, sendo o processo de dessorção de água das sementes de alface controlado pela entalpia.
Mostrar más [+] Menos [-]Thermodynamic properties of water desorption in lettuce seeds Texto completo
2018
Juliana Soares Zeymer | Paulo Cesar Corrêa | Gabriel Henrique Horta de Oliveira | Fernanda Machado Baptestini
Knowledge of the movement of water molecules inside material is important for the study of interactions between water and chemical components of agricultural products. The thermodynamic properties calculation reports this need, being the source of information to design drying equipment, calculate the energy required in this process and evaluate the physical phenomena that occur on the food surface. Given the importance of the subject, the objective of this study was to determine the thermodynamic properties of the water desorption process in lettuce seeds. Lettuce seeds had an initial moisture content of 9.3% (d.b.). The equilibrium moisture content of seeds was determined by static gravimetric method at different temperatures (10, 20, 30, 40 and 50 ± 1 °C) and relative humidity values (between 11 and 96%). Experiments were conducted in triplicate. It was observed that, with increasing equilibrium moisture content, there was a reduction in the energy required for evaporation of water in lettuce seeds, with values of integral isosteric heat of desorption in the water content range 2.1 to 21.2% (d.b.) which varied from ‘4164.89 to 2477.43’ kJ kg-1. With increasing equilibrium moisture content there was a decrease in differential entropy, resulting in lower demand for mobility of water molecules. The Gibbs free energy also decreased with increasing equilibrium moisture content and was positive for all temperatures studied, showing non-spontaneity of water desorption in the seeds. The enthalpy-entropy compensation theory was has been satisfactorily applied to the sorption phenomenon and the water desorption process in lettuce seeds was controlled by enthalpy.
Mostrar más [+] Menos [-]Thermodynamic properties of water desorption in lettuce seeds Texto completo
2018
Juliana Soares Zeymer | Paulo Cesar Corrêa | Gabriel Henrique Horta de Oliveira | Fernanda Machado Baptestini
Knowledge of the movement of water molecules inside material is important for the study of interactions between water and chemical components of agricultural products. The thermodynamic properties calculation reports this need, being the source of information to design drying equipment, calculate the energy required in this process and evaluate the physical phenomena that occur on the food surface. Given the importance of the subject, the objective of this study was to determine the thermodynamic properties of the water desorption process in lettuce seeds. Lettuce seeds had an initial moisture content of 9.3% (d.b.). The equilibrium moisture content of seeds was determined by static gravimetric method at different temperatures (10, 20, 30, 40 and 50 ± 1 °C) and relative humidity values (between 11 and 96%). Experiments were conducted in triplicate. It was observed that, with increasing equilibrium moisture content, there was a reduction in the energy required for evaporation of water in lettuce seeds, with values of integral isosteric heat of desorption in the water content range 2.1 to 21.2% (d.b.) which varied from ‘4164.89 to 2477.43’ kJ kg-1. With increasing equilibrium moisture content there was a decrease in differential entropy, resulting in lower demand for mobility of water molecules. The Gibbs free energy also decreased with increasing equilibrium moisture content and was positive for all temperatures studied, showing non-spontaneity of water desorption in the seeds. The enthalpy-entropy compensation theory was has been satisfactorily applied to the sorption phenomenon and the water desorption process in lettuce seeds was controlled by enthalpy.
Mostrar más [+] Menos [-]AGRONOMIC PERFORMANCE OF GÉRBERA UNDER WATER REUSE ABSTRACT | DESEMPENHO AGRONÔMICO DE GÉRBERA SOB REUSO DE ÁGUA - DOI: 10.7127/rbai.v12n600922
2018
Carvalho, Pedro Henrique Máximo de Souza | Santos Costa, William Ralf | Silva e Silva, Jamerson | Queiroz, Sérgio Oliveira Pinto de | Souza, Joselita Cardoso de
The present work had as objective to evaluate the productive performance of gerbera under two management of the irrigation and different qualities of water, in protected environment. The experimental design was a completely randomized design, in a subdivided plots scheme, with three water qualities (water of the São Francisco river plus fertilization, stabilization pond effluent enriched with 50% of chemical fertilization, stabilization pond effluent) in the plots and two methods of irrigation management (drainage lysimeter and evaporator of piché) in the subplots. The plants were cultivated on commercial substratum Tropstrato in pots with 5 L of volume, spaced 0.50 mx 0.80 m, drip irrigated, with the emitters nominal flow of 2 L h-1, under service pressure of 200 kPa. The variables analyzed were: stem length (CH), stem diameter (DH), chapter diameter (DC), total productivity (PT) and water use efficiency (USA). From the results obtained and for the experimental conditions it is possible to conclude that the stabilization pond effluent was able to meet the nutritional requirement of the gerbera plants, resulting in the same qualitative and productive performance of the gerbera plants as the one obtained under fertirrigation. | O presente trabalho teve como objetivo avaliar o desempenho produtivo da gérbera sob dois manejos da irrigação e diferentes qualidades de água, em ambiente protegido. O delineamento experimental adotado foi o inteiramente casualizado, em esquema de parcelas subdivididas, tendo três qualidades de água (água do rio São Francisco acrescida de fertilização; efluente de lagoa de estabilização enriquecido com 50% da fertilização química e efluente de lagoa de estabilização) nas parcelas e dois métodos de manejo de irrigação (lisímetro de drenagem e evaporímetro de piché) nas subparcelas. As plantas foram cultivadas em substrato comercial Tropstrato, em vasos com 5 L de volume, sob espaçamento de 0,50 m x 0,80 m, irrigadas por gotejamento, tendo os emissores vazão nominal de 2 L h<sup>-1</sup>, sob pressão de serviço de 200 kPa. As variáveis analisadas foram: comprimento da haste (CH), diâmetro de haste (DH), diâmetro de <em>capítulo</em> (DC), produtividade total (PT) e eficiência no uso da água (EUA). A partir dos resultados obtidos e para as condições experimentais é possível concluir que o efluente de lagoa de estabilização foi capaz de atender ao requerimento nutricional das plantas de gérbera, resultando em mesmo desempenho qualitativo e produtivo das plantas de gérbera que aquele obtido sob fertirrigação.
Mostrar más [+] Menos [-]Recolector de agua, captada de la atmósfera, para zonas rurales | Water collector, catched from the atmosphere, for rural zones Texto completo
2018
Nicolás Medina Ospina | Morales Silva, Leonardo
Diseñar un sistema de recolección de agua, proveniente de la humedad del aire, que mitigue la escasez de agua en las temporadas secas del año, por medio de la aplicación de conceptos básicos de termodinámica aplicada y bio geo diseño. Donde el diseño aporta la mejora de los sistemas mediante su pensamiento divergente. La investigación de este proyecto se realizó utilizando 6 metodologías: 1. Método científico 2. Método epistemológico formalizante 3. Design thinking 4. “¿Qué? ¿Cómo? ¿Por qué? 5. Biónica 6. Bernd lobach. Con estas metodologías reencontró que la zona piloto de aplicación, Tunja, Boyacá, es un lugar idóneo para realizar el proyecto. Recolector de agua, captada de la atmósfera, para zonas rurales. Es el nombre de este proyecto, que llega a recolectar dos mil litros de agua en un periodo de 24 horas, que podría mitigar el problema de escasez de agua en épocas de sequía. Para efectos de llevar eso acabo se utilizan los paquetes técnicos similares a ares acondicionados y materiales de alta resistencia. Para garantizar a los campesinos y neo campesinos (que son nuestros usuarios) una vida útil de mínimo 20 años. Bachue, agua y vida se nombró al producto resultante de este proyecto, que por medio de su producción de agua, permite una recuperación de la inversión aproximadamente en 44 meses. Es un producto único en su escala a nivel Latinoamérica que puede llegar a producirse en diferentes escalas para suplir diferentes necesidades y llegar a más usuarios. | Diseñador industrial | Pregrado | Design a system for collecting water, coming from the humidity of the air, which will alleviate water shortages in the dry season of the year, through the application of basic concepts of applied thermodynamics and bio geo design. Where the design provides improvement of systems through their divergent thinking. This project research was carried out using 6 methodologies: 1. scientific method 2. Formalizing epistemological method 3. Design thinking 4. "What? How? Why? 5 Bionic 6. Bernd lobatch. with these methodologies re found that the pilot area of application, Tunja, Boyacá, is an ideal place to carry out the project. Collecting of water, collected from the atmosphere, for rural areas. It is the name of this project, coming to collect two thousand liters of water in a period of 24 hours, which could alleviate the problem of scarcity of water in times of drought. For purposes of lead that I just used similar technical packages to ares conditioners and materials of high strength. To ensure that farmers and neo farmers (who are our users) a useful life of at least 20 years. Bachué, water and life was named the product resulting from this project, which through its production of water, enables a payback about in 44 months. It is a unique product in its scale to Latin America level that may occur at different scales for different needs and reach more users
Mostrar más [+] Menos [-]Agroalimentación, agua y sostenibilidad Texto completo
2018
Melgarejo, Joaquín (ed.) | Abadía Sánchez, Ricardo (ed.) | Universidad de Alicante. Departamento de Análisis Económico Aplicado | Recursos Hídricos y Desarrollo Sostenible
Las páginas que aquí se presentan recogen los textos referidos a las ponencias de la segunda edición del Simposyum Agroalimentario de la Vega Baja del Segura (SYA), que tuvo lugar los días 23 y 24 de noviembre de 2017, bajo el lema: agroalimentación, agua y sostenibilidad. En dicho encuentro se reunieron en el Auditorio de la Lonja de Orihuela los grandes referentes del sector agroalimentario por segundo año consecutivo, con el objetivo de dialogar, debatir e intercambiar conocimiento en busca de las claves del crecimiento y del desarrollo sostenible del sector. El éxito del evento denominado SYA ORIHUELA, tras las ediciones de 2016 y 2017, se constata y crece progresivamente en cada nuevo encuentro. Así, este libro continúa la serie iniciada con el titulado “El sector agroalimentario: sostenibilidad, cooperación y expansión”. El objetivo de esta publicación ha sido confeccionar un documento en el cual pueda quedar constancia de gran parte de ese conocimiento generado durante el simposio.
Mostrar más [+] Menos [-]Suelo, agua y manejo Texto completo
2018
Alconada Magliano, Margarita María | Cerisola, Cecilia | Cuellas, Marisol | Alconada Magliano, Margarita María | Martínez, Susana Beatriz | Garbi, Mariana
- Suelo y agua: Indicadores de calidad y degradación. Manejo: control de la salinidad, alcalinidad y drenaje | Margarita M Alconada Magliano. - Experiencias en el manejo del drenaje. Subsolado y Cincel | Cecilia Cerisola. - Drenes corrugados, PVC | Marisol Cuellas y Margarita Alconada M. | Facultad de Ciencias Agrarias y Forestales
Mostrar más [+] Menos [-]Agua para la industria Texto completo
2018
Simbron Velasquez, Kelly Soledad
El objetivo de este trabajo de investigación es dar a conocer que el agua es un elemento fundamental para los seres vivos, esta sustancia líquida está compuesto por la unión de dos elementos químicos, hidrógeno (H) y oxígeno (O) que son abundantes en la tierra. El agua es la sustancia más importante en muchas actividades, tales como: la industria, agricultura, ganadería y la minería, para lo cual es importante tener en cuenta la calidad del agua para el consumo, el agua representa el 80% de composición en los seres vivos. El agua pasa por el proceso de ciclo hidrológico que es un fenómeno ocurrido por la energía solar, sin embargo, solo el 2,5 % del agua almacenada en la tierra es agua dulce apto para el consumo humano y el 71% de agua representa a nivel de toda la superficie que cubre a la tierra. El agua en la industria es una actividad fundamental en la economía de nuestra sociedad de las cuales se encarga de transformar la materia prima en valor agregado convirtiendo en grandes cantidades de energía dentro de la industria, el agua es el factor principal dentro de la industria hidroeléctrica, hidráulica que ayuda a generar energía a través de la fuerza de caída del agua. La industria farmacéutica utiliza el agua como ingrediente principal en la producción de inyectables; por lo tanto, se debe tener en cuenta la calidad del agua utilizada en la preparación de las soluciones de productos químicos. | The objective of this research work is to make known that water is a fundamental element for living beings, this liquid substance is composed of the union of two chemical elements, hydrogen (H) and oxygen (O) that are abundant in the land. Water is the most important substance in many activities, such as: industry, agriculture, livestock and mining, for which it is important take into account the quality of water for consumption, water represents 80% of composition in living beings. Water goes through the hydrological cycle process which is a phenomenon occurred by solar energy, however, only 2.5% of the water stored in The earth is fresh water suitable for human consumption and 71% of water represents at the level of the entire surface that covers the earth. Water in industry is a fundamental activity in the economy of our society, which is responsible for transforming raw materials into added value, converting large amounts of energy within the industry, water is the factor main within the hydroelectric, hydraulic industry that helps generate energy at through the force of falling water. The pharmaceutical industry uses water as main ingredient in the production of injectables; therefore, it must be taken into account the quality of the water used in the preparation of chemical product solutions.
Mostrar más [+] Menos [-]Manual de los Reglamentos del Agua en Florida: Ley del Agua de 2016 Texto completo
2018
Michael T. Olexa | Tatiana Borisova | Jarrett Davis
La Ley del Agua de la Florida de 2016 es una política de agua integral que aborda los problemas críticos de abastecimiento de agua y calidad de la Florida. Entró en vigor el 1 de julio de 2016. La Ley del Agua de la Florida de 2016 creó la Ley de Protección de Acuíferos y Manantiales de Florida, codificó la Iniciativa de la Florida Central y revisó la Ley de los Everglades y Estuarios del Norte.
Mostrar más [+] Menos [-]Manual de los Reglamentos del Agua en Florida: Ley del Agua de 2016 Texto completo
2018
Michael T. Olexa | Tatiana Borisova | Jarrett Davis
La Ley del Agua de la Florida de 2016 es una política de agua integral que aborda los problemas críticos de abastecimiento de agua y calidad de la Florida. Entró en vigor el 1 de julio de 2016. La Ley del Agua de la Florida de 2016 creó la Ley de Protección de Acuíferos y Manantiales de Florida, codificó la Iniciativa de la Florida Central y revisó la Ley de los Everglades y Estuarios del Norte.
Mostrar más [+] Menos [-]Manual de los Reglamentos del Agua en Florida: Ley del Agua de 2016 Texto completo
2018
Michael T. Olexa | Tatiana Borisova | Jarrett Davis
La Ley del Agua de la Florida de 2016 es una política de agua integral que aborda los problemas críticos de abastecimiento de agua y calidad de la Florida. Entró en vigor el 1 de julio de 2016. La Ley del Agua de la Florida de 2016 creó la Ley de Protección de Acuíferos y Manantiales de Florida, codificó la Iniciativa de la Florida Central y revisó la Ley de los Everglades y Estuarios del Norte.
Mostrar más [+] Menos [-]Sensitivity parameters during the emptying maneuvers in water pipelines | Parámetros significativos durante los procesos de vaciado en conducciones de agua Texto completo
2018
Coronado-Hernández, O.E. | Fuertes-Miquel, V.S. | Iglesias-Rey, P.L. | Mora-Meliá, D.
Emptying pipelines can be critical in many water pipelines because subatmospheric pressure troughs are reached due to the expansion of entrapped air, which could cause considerable damage to the system depending on both installation conditions and stiffness pipe. This paper shows the sensitivity analysis for the mathematical model proposed by the authors, where the main hydraulic and thermodynamic parameters are analyzed (internal pipe diameter, friction factor, pipe slope, polytropic coefficient, air valve diameter, air pocket size and time maneuvering of the drain valve). Two cases were analyzed: (i) a pipe with the upstream end closed, and (ii) a pipe with an air valve installed in the upstream end. The results show that in the Case No.1, pipe slope, polytropic coefficient and air pocket size parameters are very sensitive on the subatmospheric pressure troughs, and on the other hand in the Case No. 2, the majority of parameters are very sensitive during the emptying process. | El proceso de vaciado en conducciones de agua genera depresiones por la expansión del aire en el interior de las tuberías y esto podría causar el colapso del sistema dependiendo de las condiciones de instalación y de la rigidez de la conducción. En este artículo se presenta el análisis de sensibilidad del modelo matemático desarrollado por los autores, analizando los principales parámetros hidráulicos y termodinámicos que intervienen en este proceso tales como: diámetro interior de la tubería, factor de fricción, pendiente longitudinal de la tubería, coeficiente politrópico, diámetro de la ventosa, tamaño de la bolsa de aire y tiempo de apertura. Este análisis se realizó para dos casos posibles: Caso No. 1, tubería con el extremo aguas arriba cerrado; y Caso No. 2, tubería con una ventosa instalada en el extremo aguas arriba. Los resultados muestran que para el Caso No. 1 los parámetros que más inciden en las depresiones son la pendiente longitudinal de la tubería, el coeficiente politrópico y el tamaño de la bolsa de aire; mientras que para el Caso No. 2, la mayoría de los parámetros influyen significativamente durante el proceso de vaciado.
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