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| Registros recuperados: 14 | |
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| Rajoka,Muhammad Ibrahim; Khan,Sana. |
| Production of β-xylosidaseby a cycloheximide and 2-deoxy-D-glucose-resistant mutant of Kluyveromyces marxianus PPY125 was studied when cultured on growth media containing galactose, glucose, xylose, cellobiose, sucrose and lactose as carbon sources. Xylose, cellobiose, lactose and sucrose were the key substrates. Both K. marxianus PPY125 and its mutant (M 125) supported maximum β-xylosidase specific product yield (Y P/X) following growth on xylose. Basal level of activity was observed in non-induced cultures grown on glucose. The mutant produced 1.5 to 2-fold more β-xylosidase than that produced by the wild cells. Synthesis of β-xylosidase was regulated by an induction mechanism in both wild and mutant cells. Addition of... |
| Tipo: Journal article |
Palavras-chave: Enthalpy; Entropy; Enzyme kinetics; Fermentation; Induction; Thermodynamics. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000200007 |
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| Vergütz,Leonardus; Silva,Luis Henrique Mendes da; Novais,Roberto Ferreira; Silva,Maria do Carmo Hespanhol da; Mageste,Aparecida Barbosa; Silva,Ivo Ribeiro. |
| ABSTRACT Humic acids (HA) are a component of humic substances (HS), which are found in nearly all soils, sediments, and waters. They play a key role in many, if not most, chemical and physical properties in their environment. Despite the importance of HA, their high complexity makes them a poorly understood system. Therefore, understanding the physicochemical properties and interactions of HA is crucial for determining their fundamental role and obtaining structural details. Cationic surfactants are known to interact electrostatically and hydrophobically with HA. Because they are a very well-known and characterized system, they offer a good choice as molecular probes for studying HA. The objective of this study was to evaluate the interaction between... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enthalpy; Humic substances; Isothermal titration calorimetry; Macromolecular structure; Microcalorimetry; Supramolecular structure. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832015000601633 |
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| Silva,Hellismar W. da; Rodovalho,Renato S.; Velasco,Marya F.; Silva,Camila F.; Vale,Luís S. R.. |
| ABSTRACT The objective of this study was to determine and model the drying kinetics of 'Cabacinha' pepper fruits at different temperatures of the drying air, as well as obtain the thermodynamic properties involved in the drying process of the product. Drying was carried out under controlled conductions of temperature (60, 70, 80, 90 and 100 °C) using three samples of 130 g of fruit, which were weighed periodically until constant mass. The experimental data were adjusted to different mathematical models often used in the representation of fruit drying. Effective diffusion coefficients, calculated from the mathematical model of liquid diffusion, were used to obtain activation energy, enthalpy, entropy and Gibbs free energy. The Midilli model showed the best... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Capsicum chinense L.; Moisture ratio; Enthalpy; Activation energy. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000200174 |
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| Corrêa,Paulo C.; Baptestini,Fernanda M.; Vanegas,Jaime D. B.; Leite,Rafael; Botelho,Fernando M.; Oliveira,Gabriel H. H. de. |
| ABSTRACT This study aims to determine the thermodynamic properties of damaged beans. Grains with initial moisture content of 53.85% (d.b.) were used. A part of the grains was used to obtain the desorption isotherms, while another part was subjected to drying until a moisture content of 5.26% (d.b.) was achieved; therefore, it was subjected to the adsorption process. To induce damage, a Stein breakage tester was used. To obtain the equilibrium moisture content, grains were placed in a climatic chamber whose temperatures were 20, 30, 40, and 50 ± 1 °C combined with a relative humidity of 30, 40, 50, 70, and 90 ± 3%. Although in the desorption process, damaged grains had a lower differential enthalpy compared with the control, the reverse behavior was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Enthalpy; Entropy; Gibbs free energy. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000800556 |
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| Costa,Cristian F.; Corrêa,Paulo C.; Vanegas,Jaime D. B.; Baptestini,Fernanda M.; Campos,Renata C.; Fernandes,Lara S.. |
| ABSTRACT Jabuticaba is a fruit native of Brazil and, besides containing many nutritional qualities, it also has a good field for use in products such as flour for cakes and biscuits, juice, liqueur, jelly and others. This study aimed to model the drying kinetics and determine the thermodynamic properties of jabuticaba peel at different drying air temperatures. Ripe fruits of jabuticaba (Myrciaria jaboticaba) were collected and pulped manually. Drying was carried out in a forced-air circulation oven with a flow of 5.6 m s-1 at temperatures of 40, 50, 60 and 70 °C. Six mathematical models commonly used to represent the drying process of agricultural products were fitted to the experimental data. The Arrhenius model was used to represent the drying constant... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Myrciaria jaboticaba; Enthalpy; Entropy. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662016000600576 |
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| Pereira,Dayana Cristina de Oliveira; Miranda,Késia Oliveira da Silva; Demattê Filho,Luiz Carlos; Pereira,Gustavo do Valle; Piedade,Sonia Maria De Stefano; Berno,Patricia Rodrigues. |
| ABSTRACT The objective of this study was to evaluate the effect of the presence of roosters on welfare and egg production of laying hens reared in an alternative system. Two breeding systems were established: barn 1 - laying hens reared without roosters (4500 birds); and barn 2 - laying hens reared with roosters (4500 layers and 250 roosters). In the poultry facilities, microclimate, egg production, mortality rate, and bird behavior were evaluated. Microclimate analysis showed that the birds were subjected to periods of constant heat stress, except for the morning hours. However, even under these conditions, egg production results and mortality rate were consistent with the indices recommended in the Isa Brown management guide in the barn with roosters;... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Behavior; Enthalpy; Husbandry environment; Laying hens. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-35982017000300175 |
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| Oliveira, Daniel Emanuel Cabral de; Resende, Osvaldo; Costa, Lílian Moreira; Silva, Hellismar Wakson da. |
| This study aimed to determine and evaluate the thermodynamic properties of crambe fruit at different equilibrium moisture contents. The dynamic-gravimetric method was used to collect experimental data. Crambe fruits with an initial moisture content of approximately 26% db (dry basis) were used. The thin-layer desorption of the product was conducted at different controlled temperatures (25, 30, 35, 40, and 45°C) and at water activity levels ranging from 0.10 to 0.89 until the product reached the equilibrium moisture content at the specified air condition. In conclusion, the thermodynamic properties of crambe fruit are affected by temperature and moisture content. The isokinetic theory is valid for the desorption process, which is controlled by enthalpy,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 5.03.03.00-7 Crambe abyssinica; Enthalpy; Entropy; Gibbs free energy; Enharia de Processamento de Produtos Agrícolas. |
| Ano: 2017 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/32516 |
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| Fadel, Moustafa Amin; Bani Hammad, Bani A.; AlHosany, Faisal; Iwaimer, Osama. |
| Greenhouse covering material is the most governing member of the construction which controls two major parameters, the amount of light and heat diffused from the surrounding environment into the internal space. In hot areas, balancing between optimum temperature and maximum light intensity inside the greenhouse consumes most of the energy spent in vegetable production systems. In this research, a special testing stand was fabricated to simulate the structure of a typical greenhouse provided with a 400W full spectrum light as a source of light and heat. Tests were carried out to investigate the effectiveness of different commercial covering material in light and heat diffusion. Twenty one combinations of Fiberglass, Polyethylene, Polycarbonate, Plexiglass... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Agricultural Engineering greenhouse; Enthalpy; Air temperature; Light transmittance; Covering materials. |
| Ano: 2016 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3240 |
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| Zeymer,Juliana Soares; Corrêa,Paulo Cesar; Oliveira,Gabriel Henrique Horta de; Araujo,Marcos Eduardo Viana de; Magalhães,Diana Soares. |
| ABSTRACT Studies about the thermodynamic properties of ryegrass seeds are necessary to improve post-harvest processes, relating the factors that affect product quality with the interaction between water and its chemical components. Given the importance of recognizing and understanding the intrinsic behavior of water in ryegrass seeds and providing data for the improvement of industrial drying equipment, this work aimed to calculate and evaluate the thermodynamic properties of moisture desorption of ryegrass seeds as a function of the equilibrium moisture content. Ryegrass seeds with initial moisture content of 10.4 (% d.b.) was used. The equilibrium moisture content of seeds was determined by static-gravimetric method at different temperatures (10, 20, 30,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Gibbs free energy; Entropy; Enthalpy; Water activity; Chung Pfost.. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542020000100202 |
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| Registros recuperados: 14 | |
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