Sistema de secagem solar para frutos tropicais e modelagem da secagem de banana em um secador de coluna estática

In this study were projected, built and tested an electric solar dryer consisting of a solar collector, a drying chamber, an exhaust fan and a fan to promote forced hot air convection. Banana drying experiments were also carried out in a static column dryer to model the drying and to obtain parameters that can be used as a first approximation in the modeling of an electric solar dryer, depending on the similarity of the experimental conditions between the two drying systems. From the banana drying experiments conducted in the static column dryer, we obtained food weight data as a function of aqueous concentration and temperature. Simplified mathematical models of the banana drying were made, based on Fick s and Fourier s second equations, which were tested with the experimental data. We determined and/or modeled parameters such as banana moisture content, density, thin layer drying curves, equilibrium moisture content, molecular diffusivity of the water in banana DAB, external mass transfer coefficient kM, specific heat Cp, thermal conductivity k, latent heat of water evaporation in the food Lfood, time to heat food, and minimum energy and power required to heat the food and evaporate the water. When we considered the shrinkage of radius R of a banana, the calculated values of DAB and kM generally better represent the phenomenon of water diffusion in a solid. The latent heat of water evaporation in the food Lfood calculated by modeling is higher than the latent heat of pure water evaporation Lwater. The values calculated for DAB and KM that best represent the drying were obtained with the analytical model of the present paper. These values had good agreement with those assessed with a numeric model described in the literature, in which convective boundary condition and food shrinkage are considered. Using parameters such as Cp, DAB, k, kM and Lfood, one can elaborate the preliminary dryer project and calculate the economy using only solar energy rather than using solar energy along with electrical energy

Concepção de um secador rotatório para secagem do cefalotórax do camarão

The present work has as objective the knowledge of the process of drying of the cephalothorax of shrimp to give support the industry to make possible the use of this byproduct. In this sense, the process conditions in this tray dryer and spouted bed were analyzed. With these results, it was projected and constructs a dryer with specific characteristics for the drying of the cephalothorax. The desorption isotherms were obtained by the dynamic method in the temperatures of 20, 35 and 50º C and in the interval of 10-90% of relative humidity. It was observed that the product in form of powder can be conserved with larger stability for lower relative humidity to 40%. The curves of drying of the dryer of fixed bed were adjusted for the models: single exponential, biparametric exponential and Page. The model biparametric exponential more adequately described all the drying conditions studied. The tests carry out in spouted bed showed high drying rate for the material in the paste form in beds active dynamicly-fluid, provely the necessity of a feeding in shorter intervals of time to increase the thermal efficiency of the process. The projected dryer, be considered the obtained results, it was a rotary dryer with inert bed, feed co-current, discharge in cyclone to take place the separation gas-solid, and feed carry out in intervals of 2 minutes. The optimization of the equipment projected it was accomplished used the complete factorial experimental design 24, this had as independent variables temperature velocity of the air, feed flow rate and encapsulated concentration (albumin), as variables answers the thermal efficiency, the moisture content of obtained powder, total time of test and the efficiency of production of powder in several points of processing. The results showed that the rotary dryer with inert bed can present, also, good results if applied industrially

Properties of a new fungal b-galactosidase with potential application in the dairy industry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Atividade antifúngica de extratos de Momordica charantia L. sobre Colletotrichum musae

Os objetivos do presente trabalho foram avaliar os efeitos de extratos de Momordica charantia sobre o crescimento micelial e a germinação de conídios de Colletotrichum musae, e a eficiência destes extratos no controle da antracnose, causada por C. musae, em bananas. Extratos aquoso e hidroetanólico, obtidos de folhas e ramos, na concentração de 50% em relação ao volume adicionado, em meio sólido, proporcionaram 71 e 65% de inibição do crescimento micelial, respectivamente, enquanto que em meio líquido, a inibição do crescimento micelial foi de 86 e 81%, respectivamente. Somente o extrato aquoso e o tiofanato metílico, nas concentrações de 50% e 1000 µg mL-1 respectivamente, proporcionaram 100% de inibição da germinação de esporos de C. musae. Os extratos metanólico e aquoso inibiram em 80 e 70%, respectivamente, o desenvolvimento das lesões em bananas, quando aplicados até dois dias antes da inoculação do fungo. Estes resultados foram semelhantes ao tratamento com tiofanato metílico, que inibiu 80% do desenvolvimento das lesões. Confirma-se a presença de substância antifúngica nos extratos de M. charantia e outros estudos devem ser realizados para viabilizar seu uso no controle da antracnose da banana.

Propriedades Físicas do Semicondutor Bi2Te3

Thermoelectric Refrigerators (TEC Thermoelectric Cooling) are solid-state heat pumps used in applications where stabilization of temperature cycles or cooling below the room temperature are required. TEC are based on thermoelectric devices, and these in turn, are based on the Peltier effect, which is the production of a difference in temperature when an electric current is applied to a junction formed by two non-similar materials. This is one of the three thermoelectric effects and is a typical semiconductor junction phenomenon. The thermoelectric efficiency, known as Z thermoelectric or merit figure is a parameter that measures the quality of a thermoelectric device. It depends directly on electrical conductivity and inversely on the thermal conductivity. Therefore, good thermoelectric devices have typically high values of electrical conductivity and low values of thermal conductivity. One of the most common materials in the composition of thermoelectric devices is the semiconductor bismuth telluride (Bi2Te3) and its alloys. Peltier plates made up by crystals of semiconductor P-type and N-type are commercially available for various applications in thermoelectric systems. In this work, we characterize the electrical properties of bismuth telluride through conductivity/resistivity of the material, and X-rays power diffraction and magnetoresistance measurements. The results were compared with values taken from specific literature. Moreover, two techniques of material preparation, and applications in refrigerators, are discussed

Filtros acústicos em cristais fonônicos

In this work, we have studied the acoustic phonon wave propagation within the periodic and quasiperiodic superlattices of Fibonacci type. These structures are formed by phononic crystals, whose periodicity allows the raise of regions known as stop bands, which prevent the phonon propagation throughout the structure for specific frequency values. This phenomenon allows the construction of acoustic filters with great technological potential. Our theoretical model were based on the method of the transfer matrix, thery acoustics phonons which describes the propagation of the transverse and longitudinal modes within a unit cell, linking them with the precedent cell in the multilayer structure. The transfer matrix is built taking into account the elastic and electromagnetic boundary conditions in the superllatice interfaces, and it is related to the coupled differential equation solutions (elastic and electromagnetic) that describe each model under consideration. We investigated the piezoelectric properties of GaN and AlN the nitride semiconductors, whose properties are important to applications in the semiconductor device industry. The calculations that characterize the piezoelectric system, depend strongly on the cubic (zinc-bend) and hexagonal (wurtzite) crystal symmetries, that are described the elastic and piezoelectric tensors. The investigation of the liquid Hg (mercury), Ga (gallium) and Ar (argon) systems in static conditions also using the classical theory of elasticity. Together with the Euler s equation of fluid mechanics they one solved to the solid/liquid and the liquid/liquid interfaces to obtain and discuss several interesting physical results. In particular, the acoustical filters obtained from these structures are again presented and their features discussed

Aplicações da q-Álgebra em física da matéria condensada

We address the generalization of thermodynamic quantity q-deformed by q-algebra that describes a general algebra for bosons and fermions . The motivation for our study stems from an interest to strengthen our initial ideas, and a possible experimental application. On our journey, we met a generalization of the recently proposed formalism of the q-calculus, which is the application of a generalized sequence described by two parameters deformation positive real independent and q1 and q2, known for Fibonacci oscillators . We apply the wellknown problem of Landau diamagnetism immersed in a space D-dimensional, which still generates good discussions by its nature, and dependence with the number of dimensions D, enables us future extend its application to systems extra-dimensional, such as Modern Cosmology, Particle Physics and String Theory. We compare our results with some experimentally obtained performing major equity. We also use the formalism of the oscillators to Einstein and Debye solid, strengthening the interpretation of the q-deformation acting as a factor of disturbance or impurity in a given system, modifying the properties of the same. Our results show that the insertion of two parameters of disorder, allowed a wider range of adjustment , i.e., enabling change only the desired property, e.g., the thermal conductivity of a same element without the waste essence

Synthesis, characterization and thermal studies on solid 3-methoxybenzoate of some bivalent transition metal ions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis, characterization and thermal studies of solid state 4-methylbenzylidenepyruvate of some trivalent metal ions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis, characterization and thermal behaviour on solid pyruvates of light trivalent lanthanides

Foram sintetizados compostos Ln-L no estado sólido, onde Ln significa os lantanídeos leves trivalentes e L é o piruvato. Estes compostos foram caracterizados e estudados utilizando-se a Termogravimetria e Termogravimetria derivada (TG/DTG), calorimetria exploratória diferencial (DSC) difratometria de raios X pelo método do pó, espectroscopia na região do infravermelho, análise elementar e complexometria. Os resultados permitiram obter informações com respeito a composição, desidratação, sitio de coordenação, comportamento térmico e a decomposição térmica destes compotos.

Synthesis, characterization and thermal behaviour of solid-state compounds of 4-methoxybenzoate with lanthanum (III) and trivalent lighter lanthanides

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Imunoexpressão das claudinas -1 e -7 em ameloblastomas e germes dentais humanos

We investigated the immunohistochemistry expression of claudins -1 and -7 in ameloblastoma and in human dental germs on the pattern of distribution (focal, regional or diffuse), the cells that expressed (if central or peripheral) and the location of that expression in the cell components recital membrane, cytoplasm and nucleus. Among the 29 cases of ameloblastoma, 24 were type solid and 6 unicystic. In 7 mandibular specimens of human fetuses found dental germs from the stage of bud to the crown. We note that the pattern of expression in the dental germs was variable for claudinas studied according to the cell type and stage of differentiation and was invariate only in the cells of stellate reticulum. In epithelium internal of enamel organ, claudin-1 has been decreasing with the progression of differentiation as to claudina-7 that was found in the cells of the peripheral papilla. For ameloblastoma the expression was more significant than that observed in dental germs. Fisher s exact test no found association between the expression of claudinas cells in central and peripheral and the type of ameloblastoma (solid or unicystic). Thus, in general the claudin-1 was positive in the central cell of 93,1% of the cases and in peripheral cells of 51,7%. The claudin-7 was expressed in the cells of all cases central and peripheral cells from 89,7%. For both claudins the distribution was predominantly diffuse cells both in central and peripheral cells. Given our findings it is suggested that the expression of claudins may be indicative of the involvement of these molecules in morphogenetics events culminating with the dental development and that possibly influence the development of neoplastic ameloblastoma

Avaliação imuno-histoquímica da BMP-2, BMP-4 e seus receptores (BMPRIA e BMPRII) em ameloblastomas e tumor odontogênico adenomatóide

BMPs are components superfamily ligands transformation growth fator-β (TGF-β) secreted into the extracellular environment, with mechanisms of intercellular communication through specific ligands and receptors in various target cells, being recognized for its influence in osteogenic induction, also play an important role in tissue homeostasis, cell proliferation, differentiation control , in addition to being present in the development of various malignancies. The aim of this study was to compare the immunohistochemical expression of BMP-2, BMP-4 and its receptors BMPRIA and BMPRII in cases of ameloblastoma and adenomatoid odontogenic tumor. The sample consisted of 20 cases of solid ameloblastoma (SA), 10 cases of ameloblastoma unicystic (UA) and 16 cases of adenomatoid odontogenic tumor (AOT). The expression of BMPs and their receptors was evaluated in the parenchyma and stroma of lesions, establishing the percentage of immunopositive cells (0 - negative; 1-1 % to 10 % of cells positive; 2 - 11% to 25% of positive cells; 3 - 26% to 50% of cells positive; 4 - 51% to 75 % of positive cells; 5 - more than 75% positive cells). Analysis of the expression of BMP-2 revealed no statistically significant differences in parenchymal (p = 0.925) and stromal component (p = 0.345) between the groups, as well as BMP-4 (p = 0.873 / p = 0.131). In the epithelial component, SA and AOT had a higher frequency of score 5. In turn, all cases of UA were classified as score 5. The analysis of the stromal component showed no statistically significant difference between groups with respect to median scores BMPRIA positivity (p = 0.768) and BMPRII (p = 0.779). In the epithelial component of SA and UA, no statistically significant correlations between imunoexpression proteins analyzed were observed. In turn, the group of AOT, statistically significant positive correlations between the scores of expression of all studied proteins were found. In the stromal component, statistically significant positive correlations were found only in the SA group in BMP -4 and BMPRII (r = 0.476; p = .034), in the UA in BMP-4 and BMPRIA (r = 0.709; p = 0.022). The results of this study suggest that the BMPs and their receptors are involved in the development process odontogenic tumors. BMP-4, in turn, besides being present in odontogenic tumors have the capacity to form mineralized material.

Expressão imuno-histoquímica das integrinas a2ß1, a3ß1 e a5ß1 em adenoma pleomórfico de glândula salivar menor e maior e carcinoma adenóide cístico

Pleomorphic adenoma and adenoid cystic carcinoma (ACC) consist benign and malignant neoplasm from salivary gland, respectively. These neoplasms share some characteristics, such as cellular origin and considerable production of extracellular matrix, however, with distinct biological behavior. The aim of the present study was to compare the expression of D2E1, D3E1 e D5E1 integrins in pleomorphic adenoma from minor and major salivary glands and ACCs. Furthermore, it was investigated possible differences in the expression of these integrins according to histological subtypes of ACC. Fourteen cases of pleomorphic adenoma from major salivary gland, fourteen cases from minor salivary gland and ten cases of ACC were selected. It was taken into consideration the presence or absence, localization and intensity of integrin immunoexpression. The cases of pleomorphic adenoma were grouped in order to compare the expression between the distinct neoplasms. It was observed a highly significant difference (p<0,0001) in relation to D2E1 integrin between the neoplasms since pleomorphic adenoma showed a pronounced immunostaining. It was not possible to perform statistical tests considering the D2E1 integrin expression; nevertheless, it could be observed a tendency of higher staining in pleomorphic adenoma. For comparative reasons the cases ACCs were divided in two groups: solid and tubular/cribriform. It was not detected significant differences in regard to D2E1 integrin; and statistical analysis could not be realized in relation to D3E1 and D5E integrin expression. However, it was also verified a tendency of absence or reduced expression in the solid subtype. It can be concluded that the reduced D2E1 integrin expression observed in CACs may be related to a lesser degree of cell differentiation in this neoplasm and the reduced D5E1 integrin expression can be associated with aggressive biological behavior. Moreover, the absence and/or reduced expression of the studied integrins in solid ACC suggests a role in pathogenesis and more aggressive biological behavior of this histological subtype

Síntese e caracterização de componentes nanoestruturados de células a combustível de óxidos sólidos

Perovskite-like ceramic materials present the general formula ABO3, where A is a rare earth element or an alkaline metal element, and B is a transition metal. These materials are strong candidates to assume the position of cathode in Solid Oxide Fuel Cells (SOFC), because they present thermal stability at elevated temperatures and interesting chemical and physical properties, such as superconductivity, dieletricity, magnetic resistivity, piezoelectricity, catalytic activity and electrocatalytic and optical properties. In this work the cathodes of Solid Oxide Fuel Cells with the perovskite structure of La1-xSrxMnO3 (x = 0.15, 0.22, 0.30) and the electrolyte composed of zirconia-stabilized-yttria were synthesized by the Pechini method. The obtained resins were thermal treatment at 300 ºC for 2h and the obtained precursors were characterized by thermal analysis by DTA and TG / DTG. The powder precursors were calcined at temperatures from 450 to 1350ºC and were analyzed using XRD, FTIR, laser granulometry, XRF, surface area measurement by BET and SEM methods. The pellets were sintered from the powder to the study of bulk density and thermal expansion