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Análise da expressão do fator de transcrição Sf-1 e sua regulação em culturas primárias de adrenal de rato: o papel de Pod-1/TCF21.; Analysis of Sf-1 transcription factor and its regulation in rat adrenal cell primary culture: the role of Pod-1/TCF21.

Abreu, Nayara Pereira de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/08/2013 PT
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27.49%
O fator esteroidogênico 1 (SF-1) é um fator de transcrição envolvido no desenvolvimento, na produção de esteroides e na proliferação do córtex adrenal. POD-1/TCF21 parece estar envolvido na regulação de SF-1, inibindo sua expressão e suas funções nas células esteroidogênicas. No entanto, a expressão e a relação entre SF-1 e POD-1 em células normais adrenocorticais não está esclarecida. O objetivo desse trabalho foi determinar se Pod-1 regula a expressão de Sf-1 através da hiperexpressão de Pod-1 em culturas primárias de células adrenocorticais de rato. Foi analisada a expressão endógena de Sf-1 e Pod-1, através da reação de RT-PCR quantitativo, em células glomerulosas (G) e células fasciculadas/reticulares (F/R), bem como em células transfectadas com pCMVMycPod-1. Os resultados mostraram que Sf-1 está mais expresso nas células F/R do que nas células G e ambos os tipos celulares apresentaram baixa expressão endógena de Pod-1. As células F/R transfectadas apresentaram um aumento estatisticamente significante da expressão de Sf-1, mas não as células G. Esses resultados sugerem um mecanismo de ação de Pod-1 no controle da expressão de Sf-1 em células adrenocorticais normais distinto do descrito em células de tumores adrenais e células esteroidogênicas.; The steroidogenic factor 1 (SF-1) is a transcription factor involved in the development...

O papel do fator de transcrição POD-1 na regulação de SF-1 e LRH-1 em células tumorais da suprarrenal humana.; The role of POD-1 transcription factor in the SF-1 and LRH-1 regulation in human adrenocortical tumor cells.

França, Mônica Malheiros
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/03/2014 PT
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37.55%
SF-1 e LRH-1 são fatores de transcrição que exercem um papel fundamental na produção de esteroides nas gônadas e na suprarrenal, além de estarem envolvidos no processo tumorigênico desses órgãos. Por outro lado, POD-1 apresenta menor expressão em carcinomas adrenocorticais, e parece regular Sf-1. Nesse trabalho foi analisado o papel de POD-1 na regulação de SF-1 e de LRH-1 em células de tumores adrenocorticais. A hiperexpressão de POD-1 resultou em redução da expressão SF-1/SF-1. Em contraste, houve um aumento da expressão gênica de LRH-1, devido à diminuição da expressão de SHP, um regulador negativo de LRH-1. Nas células transfectadas com siRNA-POD-1, os níveis de POD-1 foram reduzidos e de SF-1 aumentado, reforçando o mecanismo regulatório entre os fatores. No ChIP assay, POD-1 se ligou a sequência E-box do promotor de SF-1. Por outro lado, não foi caracterizado a ligação de POD-1 no promotor LRH-1, embora POD-1 tenha se ligado ao E-box do promotor SHP. A redução de SF-1 diminuiu a expressão de StAR, mas não modulou a proliferação das células tumorais. Em resumo, POD-1 pode ter um papel mais amplo como regulador da transcrição de fatores que controlam o processo tumorigênico, e é um candidato a gene supressor de tumor nas células adrenocorticais.; SF-1 and LRH-1 have played a critical role in steroid production...

Pole placement by coordinated tuning of Power System Stabilizers and FACTS-POD stabilizers

Furini, M. A.; Pereira, A. L. S.; Araujo, P. B.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 615-622
ENG
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This work presents the application of the Decentralized Modal Control method for pole placement in multimachine power systems utilizing FACTS (Flexible AC Transmission Systems), STATCOM (Static Synchronous Compensator) and UPFC (Unified Power Flow Controller) devices. For this, these devices are equipped with supplementary damping controllers, denominated POD ( Power Oscillation Damping), achieving a coordinated project with local controllers (Power System Stabilizers - PSS). Comparative analysis on the function of damping of the FACTS, STATCOM and UPFC is performed using the New England System that has 10 generators, 39 buses and 46 transmission lines. (c) 2011 Elsevier Ltd. All rights reserved.

Ajuste de parâmetros de controladores suplementares (POD) através de redes neurais artificiais em dispositivos FACTS TCSC e SSSC

Menezes, Maxwell Martins de
Fonte: Universidade Estadual Paulista (UNESP) Publicador: Universidade Estadual Paulista (UNESP)
Tipo: Dissertação de Mestrado Formato: 116 f. : il.
POR
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37.33%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Pós-graduação em Engenharia Elétrica - FEIS; Este trabalho apresenta estudos referentes à estabilidade a pequenas perturbações do SEP, considerando a atuação de FACTS para o amortecimento das oscilações eletromecânicas de baixa frequência. São abordados os dispositivos FACTS TCSC (Thyristor Controlled Series Capacitor) e o SSSC (Static Synchronous Series Compensator). É realizada a representação e modelagem dos dispositivos FACTS no SEP inserindo no Modelo Sensibilidade de Potência. Para melhorar o desempenho do SEP no que se refere à estabilidade a pequenas perturbações, controladores suplementares são propostos para aumentar o desempenho dos dispositivos TCSC e SSSC, introduzindo o amortecimento necessário ao SEP. Adicionam-se os controladores suplementares POD no modelo modificado para os dispositivos TCSC e SSSC para verificar sua atuação. Para encontrar a melhor localização para instalação dos dispositivos é usado a teoria dos resíduos. Esta mesma teoria é usada também para o ajuste dos parâmetros dos controlares juntamente com outro ajuste feito através de Redes Neurais Artificiais (RNA), que é proposto como alternativa de comparação ao método dos resíduos. Simulações são efetuadas em um sistema teste simétrico para se verificar resultados e a eficácia do controlador POD (parâmetros ajustados pela RNA proposta)...

Production of dextran and fructose from carob pod extract and cheese whey by Leuconostoc mesenteroides NRRL B512(f)

Santos, Mariana; Rodrigues, Alírio; Teixeira, J. A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /08/2005 ENG
Relevância na Pesquisa
37.29%
The production of dextran and fructose from carob pod extract (CPE) and cheese whey (CW) as carbon source by the bacterium Leuconostoc mesenteroides was investigated. The influence of secondary carbon sources (maltose, lactose and galactose) on dextran molecular weight and fermented broth viscosity were also studied. Significant changes were not observed in broth viscosity during dextran production at initial sucrose concentration of 20 and 120 g/l. Complementary sugars maltose, lactose and galactose together with sucrose promote production of dextran with fewer glucose units. Dextran molecular weight decreases from the range 1,890,000–10,000,000 to 240,000–400,000 Da when complementary sugars are present. Polydispersity was improved when complementary sugars were used. Fermentation using mixtures of carob pod extract and cheese whey confirm these results obtained for production of dextran. Final concentrations of dextran and fructose indicate that reaction yields were not affected. Carob pod and cheese whey can be successfully used as raw material in the fermentation system described. The maximum concentrations of dextran and fructose obtained using carob pod extract resulted in 8.56 and 7.78 g/l, respectively. Combined carob pod extract and cheese whey resulted in dextran and fructose concentrations of 7.23 and 6.98 g/l...

Soybean Pod Set Enhancement with Synthetic Cytokinin Analogs

Dyer, Daniel J.; Carlson, Dale R.; Cotterman, C. Daniel; Sikorski, James A.; Ditson, Susan L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1987 EN
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27.39%
The previously reported activity of benzyladenine and selected other cytokinin analogs to increase pod set in soybean (Glycine max [L.] Merr.) was further investigated to define the structure-activity relationship and evaluate the effects of the cytokinins on yield parameters. Enhancement of pod set was found to be greatest with N-6 saturated alkyl substituted analogs, and was only weakly associated with activity in a callus growth bioassay. The response of yield parameters to increasing pod load was evaluated by applying various cytokinin analogs having a range of pod set enhancement activity. The increased pod load at the treated nodes was not compensated by a reduction in pod number on the remainder of the plant. However, there was a compensatory decrease in seed size. Overall, a significant trend to greater total seed weight per plant was associated with the increased pod number. Initial evaluations indicated that foliar applications of select cytokinins could temporarily increase pod number. However, the increases in pod number obtained with foliar treatments were too small to be of practical utility and were not maintained to maturity.

Effects of Morphactin and Other Auxin Transport Inhibitors on Soybean Senescence and Pod Development 1

Noodén, Larry D.; Noodén, S. M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1985 EN
Relevância na Pesquisa
27.36%
Because triiodobenzoic acid increases pod number, albeit variably, in soybean (Glycine max), we tested other auxin-transport inhibitors. Morphactins, especially methylchlorflurenol (MCF), were found to be very active (optimal concentration 10 micromolar) when sprayed onto the foliage. Applications at 1 week after the start of flowering were most effective, producing a 40% increase in pod number with little inhibition (12%) of stem elongation. MCF increased the number of pods initiated (reaching 1 cm length) at least partially by prolonging the initiation period, while pod abortion (failure of pods > 1 cm long) remained low. Generally, MCF did not increase seed yield (dry weight/plant); more, but smaller seeds, were formed by the treated plants. The promotive effect of MCF on pod initiation seems to be independent of its inhibition of stem elongation, which is insignificant at 10 micromolar. MCF delayed pod maturation by 3 to 4 days, while foliar yellowing, blade abscission, and petiole abscission were retarded by 2, 4, and 2 days, respectively. MCF has only a small effect on senescence and that could be indirect, due to a delay in pod development. Other auxin-transport inhibitors tested, including N-1-naphthylphthalamic acid, produced little or no increase in pod number; however...

Cell Penetrating Peptide POD Mediates Delivery of Recombinant Proteins to Retina, Cornea and Skin

Johnson, Leslie N.; Cashman, Siobhan M.; Read, Sarah Parker; Kumar-Singh, Rajendra
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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27.43%
Recently we described a novel cell penetrating peptide, POD (peptide for ocular delivery) that could deliver small molecules including fluorescent dyes into retinal cells. The objective of the current study was to examine whether biologically relevant macromolecules such as proteins, genetically fused with POD could also be delivered into retinal tissues in vivo. We generated a POD-GFP fusion protein and examined its cell and tissue penetrating properties. We found that endogenously expressed POD-GFP fusion protein localized to the nucleus, suggesting that POD acts as a nuclear localization signal. Adenovirus (Ad) vectors expressing POD-GFP fusion protein were constructed and the recombinant protein was purified from Ad-infected human embryonic retinoblasts (HER). Exogenously supplied POD-GFP fusion protein rapidly transduced A549 and HER cells and colocalized in part with markers of late endosomes, from which it could escape. Following subretinal delivery, POD-GFP localized to the retinal pigment epithelium and the photoreceptor cell bodies. When injected into the vitreous, POD-GFP localized to the ganglion cells and the inner nuclear layer of the retina as well as the lens capsule. Topical application of POD-GFP to ocular surfaces resulted in uptake by the corneal epithelium. POD-GFP also transduced non-ocular tissues...

The importance of nodule CO2 fixation for the efficiency of symbiotic nitrogen fixation in pea at vegetative growth and during pod formation

Fischinger, Stephanie Anastasia; Schulze, Joachim
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
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27.39%
Nodule CO2 fixation is of pivotal importance for N2 fixation. The process provides malate for bacteroids and oxaloacetate for nitrogen assimilation. The hypothesis of the present paper was that grain legume nodules would adapt to higher plant N demand and more restricted carbon availability at pod formation through increased nodule CO2 fixation and a more efficient N2 fixation. Growth, N2 fixation, and nodule composition during vegetative growth and at pod formation were studied in pea plants (Pisum sativum L.). In parallel experiments, 15N2 and 13CO2 uptake, as well as nodule hydrogen and CO2 release, was measured. Plants at pod formation showed higher growth rates and N2 fixation per plant when compared with vegetative growth. The specific activity of active nodules was about 25% higher at pod formation. The higher nodule activity was accompanied by higher amino acid concentration in nodules and xylem sap with a higher share of asparagine. Nodule 13CO2 fixation was increased at pod formation, both per plant and per 15N2 fixed unit. However, malate concentration in nodules was only 40% of that during vegetative growth and succinate was no longer detectable. The data indicate that increased N2 fixation at pod formation is connected with strongly increased nodule CO2 fixation. While the sugar concentration in nodules at pod formation was not altered...

Antioxidant Enzymes Regulate Reactive Oxygen Species during Pod Elongation in Pisum sativum and Brassica chinensis

Liu, Nan; Lin, Zhifang; Guan, Lanlan; Gaughan, Gerald; Lin, Guizhu
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 04/02/2014 EN
Relevância na Pesquisa
27.39%
Previous research has focused on the involvement of reactive oxygen species (ROS) in cell wall loosening and cell extension in plant vegetative growth, but few studies have investigated ROS functions specifically in plant reproductive organs. In this study, ROS levels and antioxidant enzyme activities were assessed in Pisum sativum and Brassica chinensis pods at five developmental stages. In juvenile pods, the high levels of O2.− and.OH indicates that they had functions in cell wall loosening and cell elongation. In later developmental stages, high levels of.OH were also related to increases in cell wall thickness in lignified tissues. Throughout pod development, most of the O2.− was detected on plasma membranes of parenchyma cells and outer epidermis cells of the mesocarp, while most of the H2O2 was detected on plasma membranes of most cells throughout the mesocarp. This suggests that these sites are presumably the locations of ROS generation. The antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) apparently contributed to ROS accumulation in pod wall tissues. Furthermore, specifically SOD and POD were found to be associated with pod growth through the regulation of ROS generation and transformation. Throughout pod development...

Improving Nutritional Quality of Cocoa Pod (Theobroma cacao) through Chemical and Biological Treatments for Ruminant Feeding: In vitro and In vivo Evaluation

Laconi, Erika B.; Jayanegara, Anuraga
Fonte: Asian-Australasian Association of Animal Production Societies (AAAP) and Korean Society of Animal Science and Technology (KSAST) Publicador: Asian-Australasian Association of Animal Production Societies (AAAP) and Korean Society of Animal Science and Technology (KSAST)
Tipo: Artigo de Revista Científica
Publicado em /03/2015 EN
Relevância na Pesquisa
27.43%
Cocoa pod is among the by-products of cocoa (Theobroma cacao) plantations. The aim of this study was to apply a number of treatments in order to improve nutritional quality of cocoa pod for feeding of ruminants. Cocoa pod was subjected to different treatments, i.e. C (cocoa pod without any treatment or control), CAm (cocoa pod+1.5% urea), CMo (cocoa pod+3% molasses), CRu (cocoa pod+3% rumen content) and CPh (cocoa pod+3% molasses+Phanerochaete chrysosporium inoculum). Analysis of proximate and Van Soest’s fiber fraction were performed on the respective treatments. The pods were then subjected to an in vitro digestibility evaluation by incubation in rumen fluid-buffer medium, employing a randomized complete block design (n = 3 replicates). Further, an in vivo evaluation of the pods (35% inclusion level in total mixed ration) was conducted by feeding to young Holstein steers (average body weight of 145±3.6 kg) with a 5×5 latin square design arrangement (n = 5 replicates). Each experimental period lasted for 30 d; the first 20 d was for feed adaptation, the next 3 d was for sampling of rumen liquid, and the last 7 d was for measurements of digestibility and N balance. Results revealed that lignin content was reduced significantly when cocoa pod was treated with urea...

NCG62/1: Modificaci??n del POD aprobado en Consejo de Gobierno en su sesi??n ordinaria de 19 de marzo de 2012

Universidad de Granada
Fonte: Universidade de Granada Publicador: Universidade de Granada
Tipo: Outros
SPA
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36.91%
Modificaci??n del POD aprobado en Consejo de Gobierno en su sesi??n ordinaria de 19 de marzo de 2012. Aprobado en la sesi??n extraordinaria del Consejo de Gobierno de 22 de junio de 2012

POD-1/Tcf21 overexpression reduces endogenous SF-1 and StAR expression in rat adrenal cells

França,M. M.; Abreu,N. P.; Vrechi,T. A. M.; Lotfi,C. F.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2015 EN
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37.41%
During gonad and adrenal development, the POD-1/capsulin/TCF21transcription factor negatively regulates SF-1/NR5A1expression, with higher SF-1 levels being associated with increased adrenal cell proliferation and tumorigenesis. In adrenocortical tumor cells, POD-1 binds to the SF-1 E-box promoter region, decreasing SF-1 expression. However, the modulation of SF-1 expression by POD-1 has not previously been described in normal adrenal cells. Here, we analyzed the basal expression of Pod-1 and Sf-1 in primary cultures of glomerulosa (G) and fasciculata/reticularis (F/R) cells isolated from male Sprague-Dawley rats, and investigated whether POD-1 overexpression modulates the expression of endogenous Sf-1 and its target genes in these cells. POD-1 overexpression, following the transfection of pCMVMycPod-1, significantly decreased the endogenous levels of Sf-1 mRNA and protein in F/R cells, but not in G cells, and also decreased the expression of the SF-1 target StAR in F/R cells. In G cells overexpressing POD-1, no modulation of the expression of SF-1 targets, StAR and CYP11B2, was observed. Our data showing that G and F/R cells respond differently to ectopic POD-1 expression emphasize the functional differences between the outer and inner zones of the adrenal cortex...

Eléments comparatifs de plusieurs technologies de génératrices à aimants permanents a entrainement direct pour hydroliennes; Comparison of several Direct-Drive PM Generators for Tidal Turbines

DJEBARRI, Sofiane; CHARPENTIER, Jean-Frederic; SCUILLER, Franck; BENBOUZID, Mohamed
Fonte: Société Hydrotechnique de France Publicador: Société Hydrotechnique de France
FR
Relevância na Pesquisa
27.36%
L’article présente la comparaison des dimensionnements de génératrices à entraînement direct pour des cahiers des charges d’hydroliennes. Deux types de structures magnétiques (à flux radial et à flux axial) sont étudiés. Nous considérons que ces deux structures peuvent être associées à une turbine à axe horizontal selon deux types de technologies d’intégration : POD et Rim-Driven. Dans un concept dit « Rim-Driven » la génératrice est disposée sur la périphérie des pales. Pour les technologies POD, la génératrice est logée dans une nacelle étanche placée au niveau de l’axe de l’hélice. Un point de dimensionnement nominal inspiré d’un projet d’hydrolienne préindustrielle est défini pour être utilisé, dans cette étude, pour le dimensionnement de ces génératrices. Les outils utilisés comprennent un modèle électromagnétique et un modèle thermique intégrés dans une procédure d’optimisation visant à minimiser le coût total des parties actives sous contraintes thermique et de rendement. Ces dimensionnements électromagnétiques des génératrices pour des configurations Rim-Driven et POD permettent de dégager des conclusions qualitatives sur le choix du type de génératrices et son mode d’accouplement avec l’hélice.; The aim of the paper is to compare the design of direct-drive permanent-magnet (PM) generators associated with horizontal axis tidal turbines. The turbine/generator couplings are here examined. These turbine/generator couplings consist of a POD and Rim-driven assembly. In a Rim-Driven association the electrical generator active parts are inserted in a duct surrounding the blades. For POD generator insertion...

Model Order Reduction of Non-Linear Magnetostatic Problems Based on POD and DEI Methods

HENNERON, Thomas; CLENET, Stéphane
Fonte: IEEE Publicador: IEEE
EN
Relevância na Pesquisa
37.06%
In the domain of numerical computation, Model Order Reduction approaches are more and more frequently applied in mechanics and have shown their efficiency in terms of reduction of computation time and memory storage requirements. One of these approaches, the Proper Orthogonal Decomposition (POD), can be very efficient in solving linear problems but encounters limitations in the non-linear case. In this paper, the Discret Empirical Interpolation Method coupled with the POD method is presented. This is an interesting alternative to reduce large-scale systems deriving from the discretization of non-linear magnetostatic problems coupled with an external electrical circuit.

Determinación de la cinética de liofilización en floretes de brócoli (Brassica oleracea L, var. Legacy) y evaluación del contenido de ácido L - ascórbico (L-AA) y actividad peroxidasa (POD)

Parra Vergara, Julie Carolina
Fonte: Universidad Nacional Abierta y a Distancia UNAD Publicador: Universidad Nacional Abierta y a Distancia UNAD
Tipo: Proyecto_Aplicado_o_Tesis Formato: pdf
SPA
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27.45%
Imagenes, Graficas Estadisticas, Tablas Estadisticas; La liofilización es una alternativa de interés como método de conservación de alimentos, la cual permite prolongar la vida útil manteniendo significativamente las propiedades físicas y químicas relacionadas con su calidad. El objetivo de este trabajo fue determinar la cinética de liofilización en floretes de brócoli (Brassica oleracea L, var. Legacy) y evaluar el contenido de ácido L- ascórbico (L-AA) y Actividad Peroxidasa (POD). Las muestras se sometieron a pretratamiento (escaldado a vapor durante 90±2ºC por 2 minutos) y una liofilización con congelación previa (12 horas a -26ºC); la variables de trabajo del equipo fueron de -56ºC y 0.021mbar. Los resultados de la cinética de liofilización mostro al final del proceso, ninguna diferencia significativa (p ≥0.05) en la fracción de agua retirada con y sin pretratamiento (escaldado al vapor). Igualmente se evaluó la liofilización con el modelo matemático URIF, y presento ninguna diferencia significativa (p ≥0.05) con respecto a la fracción de agua retirada, tanto en el los tratamientos (BL) y (BEL). Se evaluó el contenido del ácido L- ascórbico (L-AA) y actividad peroxidasa (POD) en floretes de brócoli (Brassica oleracea L...

POD/DEIM Nonlinear model order reduction of an ADI implicit shallow water equations model

Stefanescu, Razvan; Navon, Ionel Michael
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 12/11/2012
Relevância na Pesquisa
27.43%
In the present paper we consider a 2-D shallow-water equations (SWE) model on a $\beta$-plane solved using an alternating direction fully implicit (ADI) finite-difference scheme on a rectangular domain. The scheme was shown to be unconditionally stable for the linearized equations. The discretization yields a number of nonlinear systems of algebraic equations. We then use a proper orthogonal decomposition (POD) to reduce the dimension of the SWE model. Due to the model nonlinearities, the computational complexity of the reduced model still depends on the number of variables of the full shallow - water equations model. By employing the discrete empirical interpolation method (DEIM) we reduce the computational complexity of the reduced order model due to its depending on the nonlinear full dimension model and regain the full model reduction expected from the POD model. To emphasize the CPU gain in performance due to use of POD/DEIM, we also propose testing an explicit Euler finite difference scheme (EE) as an alternative to the ADI implicit scheme for solving the swallow water equations model. We then proceed to assess the efficiency of POD/DEIM as a function of number of spatial discretization points, time steps, and POD basis functions. As was expected...

Comparison of POD reduced order strategies for the nonlinear 2D Shallow Water Equations

Ştefănescu, Răzvan; Sandu, Adrian; Navon, Ionel M.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/02/2014
Relevância na Pesquisa
27.48%
This paper introduces tensorial calculus techniques in the framework of Proper Orthogonal Decomposition (POD) to reduce the computational complexity of the reduced nonlinear terms. The resulting method, named tensorial POD, can be applied to polynomial nonlinearities of any degree $p$. Such nonlinear terms have an on-line complexity of $\mathcal{O}(k^{p+1})$, where $k$ is the dimension of POD basis, and therefore is independent of full space dimension. However it is efficient only for quadratic nonlinear terms since for higher nonlinearities standard POD proves to be less time consuming once the POD basis dimension $k$ is increased. Numerical experiments are carried out with a two dimensional shallow water equation (SWE) test problem to compare the performance of tensorial POD, standard POD, and POD/Discrete Empirical Interpolation Method (DEIM). Numerical results show that tensorial POD decreases by $76\times$ times the computational cost of the on-line stage of standard POD for configurations using more than $300,000$ model variables. The tensorial POD SWE model was only $2-8\times$ slower than the POD/DEIM SWE model but the implementation effort is considerably increased. Tensorial calculus was again employed to construct a new algorithm allowing POD/DEIM shallow water equation model to compute its off-line stage faster than the standard and tensorial POD approaches.; Comment: 23 pages...

Characterization and evaluation of cocoa (Theobroma cacao L.) pod husk as a renewable energy source

Martínez-Ángel,J. Daniel; Villamizar-Gallardo,R. Amanda; Ortíz-Rodríguez,O. Orlando
Fonte: Colegio de Postgraduados Publicador: Colegio de Postgraduados
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2015 EN
Relevância na Pesquisa
36.91%
In Colombia, the cocoa pod husk (CPH) is expected to reach 2 100 000 t year-1 in 2021 which is usually burned or left over for decomposing outdoors at the plantations without any environmental control. Therefore, this study evaluated the energetic potential of CPH obtained after the initial processing of this fruit (Theobroma cacao L.). Three biological materials were analyzed: clone CCN-51 (CPH1), clone ICS-39 (CPH2) and a hybrid (CPH3), which present high yield and number of fruits per tree. The samples were examined by using different characterization techniques for raw biomass and ashes; in addition to the ultimate, proximate and heating value analyses, different fouling indexes were determined in order to estimate the phenomena of solids formation inside the reactor when combustion or gasification is used as a thermochemical valorization process. The Colombian CPHs contain relatively homogeneous levels of C, H and O, but very heterogeneous ash contents (1.4 to 12.9 wt %). The three studied samples showed high content of K2O in ashes (67 to 74 wt %). The higher heating value (HHV) ranged from 15 395 to 16 670 kJ kg-1. Furthermore, the fouling index and the fusibility analysis suggest the appearance of agglomeration and sintering phenomena when CPH is used as a fuel. The gasification is proposed as the process with major possibilities for the energetic use of CPH. CPH1 sample seems to allow a more stable and flexible operation...

Adsorption of Mercury(II) onto activated carbons derived from Theobroma cacao pod husk

Kede,Charles M.; Ndibewu,Peter P.; Kalumba,Makonga M.; Panichev,Nikolay A.; Ngomo,Horace M.; Ketcha,Joseph M.
Fonte: South African Journal of Chemistry Publicador: South African Journal of Chemistry
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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Activated carbon prepared from Theobroma cacao pod husk was used as a low-costbiosorbent for the removal of mercury(II) from aqueous solutions. The influence of pH and contact time on the adsorption was investigated by conducting a series of batch adsorption experiments. The equilibrium data were fitted to the Langmuir and Freundlich isotherm models. The Langmuir isotherm was found to best describe the experimental data. The amount adsorbed increased with increasing temperature. The maximum adsorption capacity of mercury was found to be 10(5) ng g-1 for an initial mercury concentration of 100 ppb. The kinetics of adsorption were modelled by means of the Lagergren-first-order and pseudo-second-order models. The pseudo-second-order model was found to explain the adsorption kinetics most effectively. It was also found that pore diffusion played an important role in the adsorption, and intra-particle diffusion was the rate-limiting step during the first 30 min. A FTIR study revealed that the carbonyl and sulfur functional groups present on the surface of the adsorbing material were involved in chemical interaction with mercury(II).