|
|
|
| Registros recuperados: 58 | |
|
|
| Brondani, Gilvano Ebling; Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP); Wendling, Ivar; Empresa Brasileira de Pesquisa Agropecuária (Embrapa - Florestas); Brondani, André Ebling; Universidade Federal Fluminense; Araujo, Marla Alessandra; Universidade Federal de Lavras; Silva, André Luís Lopes da; Universidade Federal do Paraná; Gonçalves, Antonio Natal; Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo. |
| It is possible to determine the optimum time for permanence of vegetative propagules (mini-cuttings) inside a greenhouse for rooting, and this value can be used to optimize the structure of the nursery. The aim of this study was to determine the dynamics of adventitious rooting in mini-cuttings of three clones of Eucalyptus benthamii x Eucalyptus dunnii. Sprouts of H12, H19 and H20 clones were collected from mini-stumps that were planted in gutters containing sand and grown in a semi-hydroponic system. The basal region of the mini-cuttings was immersed in 2,000 mg L-1 indole-3-butyric acid (IBA) solution for 10 seconds. The rooting percentage of the mini-cuttings, the total length of the root system and the rooting rate per mini-cutting were also evaluated... |
| Tipo: Pesquisa |
Palavras-chave: 5.01.03.04-0 vegetative propagation; Clonal forestry; Organogenesis; Mathematical modeling; Rhizogenesis; Clonal mini-garden 5.01.03.04-0. |
| Ano: 2012 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/13059 |
| |
|
|
| Absalan, Ghafour; Kianmehr, Mohammad Hossein; Arabhosseini, Akbar. |
| Compost compression processes, such as pelleting, increase bulk density, improve storability, reduce transportation costs and make easier materials handling using existing equipment for handling and storage of grains. It is important to prevent quality deterioration of pellets in long time storage. Therefore, it is necessary to reduce the moisture content of the pellets to less than or less. In this research the drying kinetics of compost pellets were studied at air temperatures of 50, 60 and 70 , air velocities of 0.5, 1 and 1.5 , particle sizes of 1.18 and 2 mm and pellet diameters of 6 and 8 mm. The maximum effective moisture diffusivity (1.78× ) was obtained at air velocity of , air temperature of 70 , particle size of 1.18 mm and pellet diameter of 8... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Drying kinetics; Effective moisture diffusivity; Mathematical modeling; Pellet. |
| Ano: 2016 |
URL: http://www.cigrjournal.org/index.php/Ejounral/article/view/3656 |
| |
|
| |
|
| |
|
|
| Grégio,Juliana M.; Caetano,Marco A.L.; Yoneyama,Takashi. |
| Optimal control theory provides a very interesting quantitative method that can be used to assist the decision making process in several areas of application, such as engineering, biology, economics and sociology. The main idea is to determine the values of the manipulated variables, such as drug doses, so that some cost function is minimized, subject to physical constraints. In this work, the cost function reflects the number of CD4+T cells, viral particles and the drug doses. It is worth noticing that high drug doses are related to more intense side-effects, apart from the impact on the actual cost of the treatment. In a previous paper by the authors, the LQR - Linear Quadratic Regulator approach was proposed for the computation of long period... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: AIDS; Filtering; Drugs; Mathematical modeling; Optimization. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652009000100002 |
| |
|
|
| Santos,Maria L.S.; Muniz,Kátia; Barros-Neto,Benício; Araujo,Moacyr. |
| The Amazon River estuary is notable at the Amazon Continental Shelf, where the presence of the large amount of water originating from the Amazon during the river's falling discharge period was made evident by the low salinity values and high nutrient levels. Even so, the presence of oceanic waters in the shelf area was significant. Dissolved organic nitrogen was the predominant species of the nitrogen cycle phases, followed by total particulate nitrogen, nitrate, ammonium and nitrite. The chlorophyll a data in the eutrophic area indicated that there is sufficient nitrogen in the area to withstand productivity, though dissolved inorganic nitrogen removal processes are faster than regeneration or mineralization. The anomalous amounts of inorganic dissolved... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon Continental Shelf; Nitrogen; Phosphate; Mathematical modeling. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652008000400011 |
| |
|
|
| Teixeira,Sirlei Dias; Fiorio,Jhonatan Luiz; Galvan,Diego; Sefstrom,Carolina; Cogo,Priscila Morgana; Sales Junior,Valber; Rodrigues,Márcio Barreto; Hendges,Ana Paula Palaro Klein; Maia,Beatriz Helena L. de Noronha Sales; Benghi,Thalita Gilda Santos. |
| ABSTRACT: The extraction of essential oils obtained by the hydrodistillation of needles/twigs waste of Pinus taeda L. was optimized by applying response surface methodology (RSM), with 24 full factorial design, in order to improve oil essential production, and aggregate value to the production chain of pine wood. Through the model it was possible to ascertain the influence of the variables in the average amount of essential oil (0.1032 mL), being the variables analyzed: biomass - Bm (x1), extraction time - ET (x2), Bm:ET (x1x2) and sample size - SS: drying times - DT (x3x4). Only linear terms (biomass and extraction time) and your interaction demonstrated significant positive values (0.0344, 0.0206 and 0.0131). The major components of the essential oil... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pinus; Byproduct; Essential oil; Response surface methodology (RSM); Mathematical modeling. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132016000100603 |
| |
|
|
| Andreola,Ricardo; Jorge,Regina Maria Matos; Santos,Onélia Aparecida Andreo dos; Jorge,Luiz Mario de Matos. |
| An industrial system for the production of white liquor of a pulp and paper industry, Klabin Paraná Papéis, formed by ten reactors was modeled, simulated, and analyzed. The developed model considered possible water losses by the evaporation and reaction, in addition to variations in the volumetric flow of lime mud across the reactors due to the composition variations. The model predictions agreed well with the process measurements at the plant and the results showed that the slaking reaction was nearly complete at the third causticizing reactor, while causticizing ends by the seventh reactor. Water loss due to slaking reaction and evaporation occurred more pronouncedly in the slaker reactor than in the final causticizing reactors; nevertheless, the lime... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Slaker reactor; Causticizing reactor; White liquor; Mathematical modeling; Simulation. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000100024 |
| |
|
|
| Longhi,Daniel Angelo; Tremarin,Andréia; Carciofi,Bruno Augusto Mattar; Laurindo,João Borges; Aragão,Gláucia Maria Falcão de. |
| The aim of this study was to establish primary and secondary models to describe the growth kinetics of Byssochlamys fulva on solidified apple juice at different temperatures. B. fulva was inoculated on solidified apple juice at 10, 15, 20, 25 and 30 °C. Linear-with-breakpoint, Baranyi and Roberts, and Huang primary models (without upper asymptote) were fitted to the data, and they showed good ability to describe the growth kinetics. B. fulva showed longer adaptation time on apple juice than on culture medium, but growth rates were similar as reported in the literature. The dependence of µmax and λ parameters on temperature was described with Square Root and Arrhenius-Davey secondary models, respectively. These models were important to establish... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mould growth; Mathematical modeling; Food microbiology; Predictive mycology. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132014000600971 |
| |
|
|
| Zehe,A.; Ramírez,A.; Starostenko,O.. |
| Electro-rotation can be used to determine the dielectric properties of cells, as well as to observe dynamic changes in both dielectric and morphological properties. Suspended biological cells and particles respond to alternating-field polarization by moving, deforming or rotating. While in linearly polarized alternating fields the particles are oriented along their axis of highest polarizability, in circularly polarized fields the axis of lowest polarizability aligns perpendicular to the plane of field rotation. Ellipsoidal models for cells are frequently applied, which include, beside sphere-shaped cells, also the limiting cases of rods and disks. Human erythrocyte cells, due to their particular shape, hardly resemble an ellipsoid. The additional effect... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electro-rotation spectra; Induced dipole moment; Mathematical modeling; Erythrocyte aggregates. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000200003 |
| |
|
|
| Machin,A.B.; Nascimento,L.F.; Mantovani,K.; Machin,E.B.. |
| Exposure to air pollution is an important cause of hospital admissions due to respiratory diseases. Nevertheless, few studies use pollutant concentration data estimated by mathematical models. A time-series ecological study was developed, using data from hospitalizations due to respiratory diseases in people over 60 years of age, residents of Cuiabá, Brazil, during 2012, obtained from the Brazilian Ministry of Health. The independent variables were the concentrations of fine particulate matter (PM2.5) and carbon monoxide (CO) estimated by mathematical modeling, minimum temperature, and relative humidity (obtained from the Brazilian Meteorological Agency), and the number of forest fires. The generalized linear regression model of Poisson was used, with lags... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Air pollutants; Particulate matter; Respiratory diseases; Elderly health; Mathematical modeling. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2019000200604 |
| |
|
| |
|
| |
|
|
| Corrêa,Paulo Cesar; Zeymer,Juliana Soares; Oliveira,Gabriel Henrique Horta de; Araujo,Marcos Eduardo Viana de; Silva,Camilla Sena da. |
| ABSTRACT It is necessary to determine the sorption isotherms of seeds to develop adequate systems of storage and drying. The chemical composition of a product affects the sorption process; products with a high oil content adsorb a lower amount of moisture from the environment than products with a high carbohydrate content. Given the importance of the hygroscopicity of different agricultural products, this work aimed to determine, model and evaluate the difference between desorption isotherms of ryegrass and flax seeds grown at different temperature and relative humidity conditions. Ryegrass and flax seeds, which contained initial moisture contents of 10.4 and 8.7% (db), respectively, were used. The equilibrium moisture content of the seeds was determined... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Equilibrium moisture content; Chemical composition; Mathematical modeling; Chung Pfost; Smith.. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542020000100215 |
| |
|
|
| MARQUES,Tadeu Alcides; RAMPAZO,Érick Malheiros; ZILLIANI,Rafael Rebes; MARQUES,Patricia Angélica Alves; BENINCASA,Fabio. |
| Abstract Sugarcane monosaccharides are reducing sugars, and classical analytical methodologies (Lane-Eynon, Benedict, complexometric-EDTA, Luff-Schoorl, Musson-Walker, Somogyi-Nelson) are based on reducing copper ions in alkaline solutions. In Brazil, certain factories use Lane-Eynon, others use the equipment referred to as “REDUTEC”, and additional factories analyze reducing sugars based on a mathematic model. The objective of this paper is to understand the relationship between variations in millivolts, mass and tenors of reducing sugars during the analysis process. Another objective is to generate an automatic model for this process. The work herein uses the equipment referred to as “REDUTEC”, a digital balance, a peristaltic pump, a digital camcorder,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mathematical modeling; Monosaccharide; Chemical determination. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612016000100070 |
| |
|
|
| Jalali,Vahideh Ranemaye Rabbani; Narain,Narendra; Silva,Gabriel Francisco da. |
| Osmotic dehydration is considered to be a suitable preprocessing step to reduce the water content of foods. Such products can be dried further by conventional drying processes to lower their water activity and thus extend their shelf life. In this work, banana (Musa sapientum) fruits were initially treated by osmosis by varying several parameters of the processing conditions which included, besides the cutting format (longitudinal and round slices) of the fruit, temperature (28 and 49 ºC), syrup concentration (50, 60 and 67 ºBrix), treatment time (2, 4, 6, 10, 14, 16 and 18 hours), fruit and syrup ratio (1:1, 1:2, 1:3 and 1:4) and agitation effects. The best quality products were obtained by the use of the 67 ºBrix syrup, for 60 minutes of osmotic... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Processing; Osmosis; Optimization; Mathematical modeling; Drying. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612008000200002 |
| |
|
| |
|
|
| OMOLOLA,Adewale Olusegun; KAPILA,Patrick Francis; SILUNGWE,Henry. |
| Abstract Drying characteristics of Cleome leaves in an oven dryer was studied. The impact of oven drying temperature (50, 60 and 70 °C) on moisture composition of the plant at a uniform air speed was considered. Eight drying models, namely, simple exponential, Page, Verma, modified Henderson and Pabis, Lewis, two term exponential, Newton, logarithmic, and Wang and Singh were fitted to drying data. Modified Henderson and Pabis model satisfactorily depicts the drying behaviour of Cleome leaves. Effective moisture diffusivity of Cleome ranged from 1.03 × 10−6 to 1.77 × 10−5 m2/s. Reliance of the calculated effective diffusivity on oven temperature was unavoidable. The required activation energy for oven drying of Cleome leaves was found to be 24.46 kJ/mol.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cleome gynandra L.; Colour; Oven drying; Effective diffusivity; Mathematical modeling; Activation energy. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612019000600588 |
| |
|
| |
|
|
| Mendes,Udenys Cabral; Resende,Osvaldo; Almeida,Dieimisson Paulo. |
| This study analyzed the variation in shape and size of Adzuki beans during soaking at different temperatures. In addition, different mathematical models were fitted to the experimental values of volumetric expansion, selecting the best one. Grains of Adzuki beans (Vigna angularis) with moisture content of approximately 0.25 (decimal d.b.) were manually harvested; they were, then, dried to 0.128 (decimal d.b.). The beans were subjected to soaking in distilled water at the temperatures 18 ± 1, 27 ± 1, 36 ± 1, and 45 ± 1 °C, in five repetitions. Recipients containing 80 mL of distilled water and 20 g of beans for each sample were used. The samples were periodically weighed in order to determine the water absorption. After that, the samples were removed from... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Physical properties; Moisture content; Mathematical modeling. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612011000300023 |
| |
| Registros recuperados: 58 | |
|
|
|
