Navegando por Data de Publicação, começando com "2008-12-05"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 4 de 4

Secagem de sementes de gramíneas (Brachiaria brizantha) em leito fluidizado
(Universidade Federal de São Carlos, 2008-12-05) Rizzi Júnior, Antonio Carlos; Freire, José Teixeira; https://lattes.cnpq.br/2270677706718167; https://lattes.cnpq.br/4688543665793400
Drying operation is an important stage of the processing that precedes the storage of seeds, since that with low moisture contents, these can retain their power of germination and other qualities for long periods. The objective of this work was to perform a study of drying of grass seeds (Brachiaria brizantha) in a batch fluidized bed, in order to evaluate the performance of the dryer in a physiological and phenomenological point of view. Fluid dynamics, heat transfer and drying tests were accomplished in order to verify the operational limitations of the equipment, as well as determining the main characteristic experimental parameters of the seeds (such as minimum fluidization velocity and transfer coefficients). Moreover, two types of models were tested (three-phase and two-phase models) with the purpose of comparing the feasibility of its applications. Sensitivity analyses were carried out on the main parameters and properties of the models aiming to discuss their strengths and weaknesses. Besides, experimental comparisons of the drying process in the equipment operating as fixed bed and fluidized bed were made. Among the main results, it was found that the simplified two-phase model provided better predictions of the drying experiments in fluidized bed, specially the temperature of the bed, than the three-phase model, which takes into account the existence of the solid, interstitial gas and bubble gas phases. By applying the hypothesis test of equality between the experimental and simulated variables, it was found a P-value equal to 0,829 for the simplified model Tm variable, better than the three-phase model corresponding variables. The adopted drying kinetics represented well the process, which presented a correlation coefficient of 0,975 between the predicted and experimental data.
Perfil cromatográfico e análise multivariada para o controle de qualidade de amostras comerciais do gênero Phyllanthus (quebra-pedra)
(Universidade Federal de São Carlos, 2008-12-05) Martins, Lucia Regina Rocha; Cass, Quezia Bezerra; https://lattes.cnpq.br/9197210255594409; https://lattes.cnpq.br/0301804822998646
This work present the development and application of methods by High Performance Liquid Chromatography (HPLC) to the quality control of vegetable samples known as stone breaker , that correspond to Phyllanthus species, two of them entered in Brazilian Pharmacopoeia: P.niruri L. and P. tenellus Roxb. A chromatographic profile analytical method was developed and validated, using HPLC with diode array detection (DAD), for the analysis of aqueous extracts of Phyllanthus authentic samples, which consisted of six species grown under controlled conditions in two different sites (Campinas and São Carlos, Brazil) and also not cultivated samples, collected in 27 cities of São Paulo state. Chemometric methods of exploratory analysis were used to interpret the chromatographic informations, such as Principal Component Analysis (PCA) and Hierarquical Cluster Analysis (HCA). Classification models (SIMCA, KNN e PLS-DA) were developed and validated and demonstrated that the Phyllanthus species can be differentiated from each other through their chromatographic profiles and multivariate analysis. The chromatographic method was applied in the analysis of 25 stone breaker commercial samples and their authenticity was determined by the classification models: the results showed that most products are produced with the P. tenellus species, although they are marketed as P. niruri; two samples was determined as adulteration since they were not classified as any Phyllanthus species. A chemical marker was purified by semi-preparative HPLC-UV from the crude aqueous extract of P. niruri specie; spectroscopy characterization determined its structure as corilagin, an hydrolisable tannin. An analytical method by HPLC-UV was developed and validated for quantification of this marker in extracts of Phyllanthus species and stone breaker commercial samples. For the cultivated samples, there was significant variability in the concentration of corilagin according to the place of cultivation and the time of year; among the non-cultivated P. tenellus samples, there was large differences in the marker concentration, result of the influence of different habitats in secondary metabolism of the plant. The corilagin quantification therefore was not feasible to determine the authenticity/quality of commercial samples, but can be used in the monitoring of Phyllanthus cultivated species. In two commercial samples the marker was not detected, which characterized as adulterated samples of stone breaker .
Análise custo/benefício da adoção de boas práticas de manejo em pesque-pague
(Universidade Federal de São Carlos, 2008-12-05) Rosa, Daniele Klöppel; Marques, João Fernando; https://lattes.cnpq.br/2090848308352950; https://lattes.cnpq.br/0481036691164883
Fish culture is na aquaculture field which has been growing a lot in the last few years, specially by fish capture stagnation and for the growing high nutritional quality animal protein demand. A market field that has been greatly developed since 1990 s and which holds huge transactions of buying and selling alive cultures fish is the fee fishing activity, moving not only São Paulo fish cultures but from other states too, like Paraná, Mato Grosso do Sul and Minas Gerais. However, as in any human activity, it has negative and positive impacts. On this perspective, this study has objected, through an environment assessment evaluation in five fee-fishing units located in Araras region, manage the proposition Best Management Practices (BMP s) use and making a cost/benefit analysis to prove the viability of those practices use. Data were collected through a previous prepared questions and fishing pounds water and sediment samples analysis and water quality parameters measures in three different moments: before, during and after the rainy period. The analysis showed there are lead and iron elements excess in water, the former is due to previous lead contamination in Mogi-Guaçu hydrographical basin, and the last one because of the region soil type. Several Best Management Practices (BMP s) were proposed and the cost/benefit analysis identified only one economic viable establishment, whereas under a 9.5% a year discount rate in a 15-year analysis, it s proved to be profitable. The studied fee-fishing units presented serious problems on economic sector, and should in an urgent way improve their administrative and management strategies in order to better explore the property potentialities and the activity the execute in a sustainable manner.
Estratégia de produção e gestão de suprimentos: estudo de casos no setor de linha branca
(Universidade Federal de São Carlos, 2008-12-05) Calife, Naiara Faiad Sebba; Nogueira, Edemilson; https://lattes.cnpq.br/5029822027693191
The growing pressure for competitiveness and development of flexible production systems enhanced the strategic role of the production to achieve the goals of global enterprises. The decisions on production should be integrated with strategic decisions of the organization, and the organizational functions of production support stop being performed individually, and also take over strategic role in corporations, it is, for instance, the case of supplies function. This study aims to identify and analyze the Production Strategies and Supplies Management in two important companies in the white line area and check out if and how the function Supplies influences and is influenced by these strategies. The white line area has experienced, since the last decade, intense process of internationalization of production and concentration of capital. Such processes accelerated the diffusion rhythm of innovations in this sector, causing changes in the management and production organization. Furthermore, the existence of a gap in the theory that relates Production Strategy and Supplies Management makes us to bring this relation into practice. One opted for an approach of qualitative and exploratory character, and the research strategy used was the case study. It was possible to check the relevance of these issues for the companies studied so that they could achieve a favorable competitive position, and it was noticed that the priorities of the area of supplies are aligned with the competitive priorities of the enterprises, showing that the supplies management acts by giving support to the production strategy and vice-versa.