191 research outputs found
Estudo sobre o controle de qualidade do palmito (Euterpe edulis Mart.) processado por apertização
To improve the quality control conditions of the processed product, the influence of some parameters on the attributes of quality of canned hear-of-palm (Euterpe edulis Mart.) was studied. The results showed that, depending on the treatment used, some attributes of quality may have important variations during processing and storage of the canned product.Com o objetivo de melhorar as condições de seu controle de qualidade, foi estudada a influência de alguns parâmetros nos atributos de qualidade do palmito (Euterpe edulis Mart.) processado por apertização. Os resultados mostraram que, dependendo dos tratamentos empregados, alguns atributos de qualidade podem sofrer variações importantes durante o processamento e armazenamento do produto enlatado
Estudo sobre o processamento do palmito (Euterpe edulis Mart.). por apertização: III. Influencia de soluções de espera e tempos de esterilização
The objective of this paper was to study the influence of pretreatment solutions and processing times on the quality of canned heart-of-palm (Euterpe edulis Mart.). The results showed that, in general, the best processing method was the pretreatment solution 5% NaCl + 1% k2s2o5 combined with thermal processing times of 50 minutes for the first three cuts and 60 minutes for the last ones. For the first three cuts, in particular, the pretreatment solution 5% NaCl + 1% citric acid combined with 45 minutes of thermal processing presented the best results for all attributes of quality, except for flavor, in which the pretreatment solution 1% citric acid + 0,25% ascorbic acid with 40 minutes of thermal processing was superior.O presente trabalho teve como objetivo estudar a influência da composição da solução de espera e de tempos de esterilização na qualidade do palmito (Euterpe edulis Mart.) processado por apertização. Os resultados mostraram que, de um modo geral, o melhor método de processamento foi o que empregou a solução de espera 5% NaCl + 1% K2S2O5 Combinada com os tempos de esterilização de 50 minutos para os três primeiros cortes e de 60 minutos para os últimos cortes. Para os três primeiros cortes, em particular, o método que empregou a solução de espera 5% NaCl+1% ácido cítrico combinada com o tempo de esterilização de 45 minutos, foi o que apresentou os melhores resultados para todos os atributos de qualidade, exceto para "flavor", em que a solução de espera 1% ácido cítrico+0,25% ácido ascórbico com 40 minutos de esterilização foi superior
Creation of a vehicular delay-tolerant network prototype
Vehicular Delay-Tolerant Network (VDTN) is a new disruptive network architecture where vehicles act as the communication infrastructure. VDTN follows a layered architecture based on control and data planes separation, and positioning the bundle layer under the network layer. VDTN furnishes low-cost asynchronous communications coping with intermittent and sparse connectivity, variable delays and even no end-to-end connection. This paper presents a VDTN prototype (testbed) proposal, which implements and validates the VDTN layered architecture considering the proposed out-of-band signaling. The main goals of the prototype are emulation, demonstration, performance evaluation, and diagnose of protocol stacks and services, proving the applicability of VDTNs over a wide range of environments.Part of this work has been supported by the Instituto de Telecomunicações, Next Generation Networks and Applications Group (NetGNA), Covilhã Delegation, Portugal in the framework of the VDTN@Lab Project, and by the Euro-NF Network of Excellence from the Seventh Framework Programme of EU
Direct and indirect effects of tree canopy facilitation in the recruitment of M editerranean oaks
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106739/1/jpe12189.pd
Estimation of flexible fuzzy GARCH models for conditional density estimation
In this work we introduce a new flexible fuzzy GARCH model for conditional density estimation. The model combines two different types of uncertainty, namely fuzziness or linguistic vagueness, and probabilistic uncertainty. The probabilistic uncertainty is modeled through a GARCH model while the fuzziness or linguistic vagueness is present in the antecedent and combination of the rule base system. The fuzzy GARCH model under study allows for a linguistic interpretation of the gradual changes in the output density, providing a simple understanding of the process. Such a system can capture different properties of data, such as fat tails, skewness and multimodality in one single model. This type of models can be useful in many fields such as macroeconomic analysis, quantitative finance and risk management. The relation to existing similar models is discussed, while the properties, interpretation and estimation of the proposed model are provided. The model performance is illustrated in simulated time series data exhibiting complex behavior and a real data application of volatility forecasting for the S&P 500 daily returns series
Influência da interação do pré-aquecimento e da remoção da película externa, na elaboração de passas de banana
The present work was conducted to check the influence and interaction of pre-heating (in oven) and removal of the external skin of bananas in the elaboration of banana figs. These treatments were employed before dipping the fruits for 10 minutes in a 2% solution of potassium metabisulfite heated to 40°C with the pH of the solution adjusted from 3.4 to 2.9. It was concluded that pre-heating the fruits influenced positively the control of enzymic browning. The removal of banana external skin did not influenced the samples pre-heated but did it negatively in the samples not pre-heated.O presente trabalho teve a finalidade de verificar a influência do prévio aquecimento em estufa e da remoção da película externa da banana na elaboração de banana passa. Esses tratamentos foram empregados antes da imersão da banana, por 10 minutos em solução aquecida a 40°C de metabisulfito de potássio a 2%, cujo pH foi ajustado a 2,9. Concluiu-se que o pré-aquecimento exerce uma ação bastante favorável no controle do escurecimento enzímico, visto que, o seu emprego resultou em produtos de muito melhor aspecto. A remoção da película da banana, não teve influência nas amostras pré-aquecidas mas influenciou negativamente as amostras que não sofreram pré-aquecimento
Influência da interação do ph da solução de metabisulfito de potássio e da remoção da película externa, na elaboração de banana passa
The present work was conducted to find ways to control enzymic browning by poliphenoloxidase in the elaboration of banana figs. Bananas were treated with SO2 by immersion in a solution of potassium metabisulfite of which, concentration, temperature, pH and time of immersion were studied, as well as the interaction between these treatments and the removal of the fruit external skin. It was concluded that the best treatment was to immerse for 10 minutes in the 2% solution at 40°C, independently of pH control. The interaction of pH and removing or not the external skin of the bananas had no influence on the ensymic browning.Este trabalho teve por objetivo encontrar meios de controlar o escurecimento enzímico catalizado pelo polifenoloxidase na elaboração de banana passa. As bananas foram tratadas com SO2, através da sua imersão em uma solução de metabisulfito de potássio. As variáveis estudadas desta solução foram, sua concentração, temperatura, pH e tempo de imersão, bem como sua interação com a remoção da panícula externa dos frutos. Concluiu-se que o melhor tratamento foi o da imersão por 10 minutos na solução de metabisulfito a 2%, aquecida a 40°C, independente do controle do pH. A interação do pH da solução com a remoção da película externa da banana não teve influência no controle do escurecimento
Di-Alkyl adipates as new phase change material for low temperature energy storage
This work is a contribution to the thermal characterization of a selected binary system of two di-n-alkyl adipates that can be used as phase change material for thermal energy storage at low temperatures. The construction of the solid–liquid phase diagram using differential scanning calorimetry (DSC), complemented with Raman Spectroscopy studies for the system composed by diethyl and dibutyl adipates is presented. The solidus and liquidus equilibrium temperatures were determined by DSC for the pure components and 30 binary mixtures at selected molar compositions were used to construct the corresponding solid–liquid phase diagram. The binary system of diethyl and dibutyl adipates presents eutectic behaviour at low temperatures. The eutectic temperature was found at 240.46 K, and the eutectic composition was determined to occur at the molar fraction xdibutyl = 0.46. Additionally, the system shows a polymorphic transition, characteristic of dibutyl adipate, occurring at ca. 238 K, confirmed by optical microscopy. To the best of our knowledge, no reference to the phase diagram of the present system could be found in the literature. Raman spectroscopy was essential to complement the construction of the phase equilibrium diagram, enabling the identification of the solid and liquid phases of the system. Finally, the liquidus curve of the phase diagram was also successfully predicted using a suitable fitting equation, being the root mean square deviation of the data from the correlation equal to 0.54 K. In addition, this fitting operation enabled a correct prediction of the eutectic composition of the system.info:eu-repo/semantics/publishedVersio
Diphenyl diselenide, a simple glutathione peroxidase mimetic, inhibits human LDL oxidation in vitro
Oxidative modification of low-density lipoprotein (LDL) represents an important factor in atherogenesis. In the present study, we have investigated the antioxidant capability of diphenyl diselenide (PhSe)2, a simple organoseleno compound, against copper (Cu2+) and peroxyl radical-induced human LDL oxidation in vitro. In initial studies using human serum, (PhSe)2 caused a dose-dependent inhibition of Cu2+-induced lipid peroxidation, which was correlated to thiol consumption. (PhSe)2 increased lipid peroxidation lag phase and decreased lipid peroxidation rate in isolated human LDL, evaluated by measuring both conjugated diene (CD) and thiobarbituric acid reactive substances (TBARS) levels. Consistent with these observations, (PhSe)2 showed a marked inhibitory effect on 2,2-azobis(2-amidinopropane dihydrochloride) (AAPH)-induced oxidation of LDL or parinaric acid (PnA) incorporated into LDL. (PhSe)2 also displayed a dose-dependent protective effect against Cu2+-induced lipid peroxidation in rat aortic slices. Interestingly, besides the antioxidant effects of (PhSe)2 toward the lipid moieties of LDL, which was related to its thiol-peroxidase activity, protein moieties from human isolated LDL were also protected against Cu2+-induced oxidation. The results presented herein are the first to show that (i) (PhSe)2 inhibits lipid peroxidation in human isolated LDL in vitro, (ii) this phenomenon is related to its thiol-peroxidase activity, and (iii) this chalcogen also prevents the oxidation of protein moieties of human LDL. Taken together, such data render (PhSe)2 a promising molecule for pharmacological studies with respect to the atherogenic process.http://www.sciencedirect.com/science/article/B6T12-4S21TS2-1/1/38250cf8bae4a4195ccd8905cf5c2a8
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