Universidade Estadual de Campinas - UNICAMP
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Item Acesso aberto (Open Access) Estudo cristalográfico da deformação plástica em monocristais de cobre(Universidade Estadual de Campinas, 1977-07-15) GOMES, José de Ribamar Seguins; MEDRANO, Ricardo EnriquePrevious results in Aluminum have show that the Critical Resolved Shear Stress is not the same for different slip system when flat single crystals are deformed. This is consequence either different stress is necessary to move edge screw dislocation or surface effect (aluminum have a oxide layer attached). In the present work similar analysis have been done in copper. Flat single crystals of special orientation have beem grown Under inert atmosphere in a graphite mould. The slip system is determined by following the tensile orientation with this purpose a deformation frame is attached to the X-Rays difractomer and movement of the tensile axis is measured by using the LAUE technique. It is found similar results than in aluminum which means that differences in flow stress are mainly tested to dislocations.Item Acesso aberto (Open Access) Estudo por espectroscopia Raman da desidratação e reidratação do clorato de bário monohidratado Ba (ClO3) 2 H2O(Universidade Estadual de Campinas, 1977-07-15) CANCELA, Luiz Sérgio Guimarães; VARGAS, Helion; http://lattes.cnpq.br/1898007894731106Item Acesso aberto (Open Access) Síntese, caracterização e termoquímica de adutos entre metil, N, N'-dimetil e tetrametiluréia com haletos de zinco, cádmio e mercúrio-II(Universidade Estadual de Campinas, 1980) ASSUNÇÃO, Francisco Pereira; AIROLDI, Claúdio; http://lattes.cnpq.br/1481366755849386The reactions of zinc, cadmium and mercury halides with the ligands methylurea (MU), N, N'-dimethylurea (DMU) and tetramethylureia (TMU) yielded the following adducts: 2nL2x2, MLX2 (M + Cd, Hg) (X =Cl, Br and L=MU, DMU and TMU), M(TMU) 2I2 (M + Zn, Cd),Cd (DMU) 3Br3 and Hg (DMU) 2Cl2. These adducts were characterized by elemental analyses, melting points, conductance measurements, thermogravimetric. ifra red spectra and mass spectra. From the values os standard enthalpies of dissolution of thehalides,ligands and adducts in suitable calorimetric solvents, the standard enthapy of the reactions was calculated: MX2(s) + nL (l,s) = MLnX2 (s); ΔHθR. For the obtention of the standard enthalpies of formation ΔHθf of the adducts ΔHθR values were used. It was also necessary to determine the standard enthalpies of formation of DMU and MU, which were obtained by means of combustion calorimetry. The standard enthalpies, ΔHθD and ΔHθM, for the equations below were also calculated, howerer, it was necessary to determine the standard enthapy of vaporation of TMU and the standard enthalpies of sublimation of DMU and MU. MLnX2(s) + Mx2(s) + nL(g) ; ΔHθD. MLnX2(s) + Mx2(s) + nL(g) ; -ΔHθM. The thermal data in conjution with the mass spectra of the adducts suggest that possibility these compouds do not exist, at least in appreciable amounts in the gaseous phase. However, the enthalpy of the metal-oxigen bond was estimated, based on the fact that this mode of coordenation has occured with these three ligands, in agreement with the infra red results. The ΔHθR parameter establiches the order of basicity, TMU>DMU>MU, and the acidity order of of the metals, Zn>Cd>Hg.Item Acesso aberto (Open Access) Fauna associada as bromelias Cannistran aff. giganteum (Baker) L. B. Smith e Neoregelia cruenta (R. Graham) L. B. Smith de restinga do litoral norte do Estado de São Paulo(Universidade Estadual de Campinas, 1981) FERREIRA, Clara Pantoja; BENSON, Woodruff Whitman; http://lattes.cnpq.br/7116492347323901An experimental set up for the study of tablets coating in a two-dimensional spouted bed that uses vibration of the perforated base to enhance the circulation of the particles was developed. An acrylic rectangular upper section (4x32 cm) with fixed 4x4 cm draft plates was adjusted over 3 different convergent secctions (inclination 50') with 4x4 cm, 4x6 cm or 4x8 cm bases and contained 800g, 1100g or 1300g of tablets, Air (0,8 to 1,6 m3/min) forced by a 7,5 cv blower, was cooled down to 55°C and spouted this bed. The lenticular tablets (0,12g; 0,25g., 0,44g) were coated with a polymeric aqucous solution (11% solids). A two-fiuid atomizer (air pressure 82,7 1(.Pa) was used, inserted lateraily, near the bed base, and showed no influence on the movement of the particles. The experimental characterization of the tablets circulation rates was emphasized, using a magnet (0,4062 g) that followed the particles, activating a bobbin located at the upper end of the draf plates, The electric pulses were processed by a data acquisition sistem and the cicie time distribution curves were adjusted by the Modiíied Spline fit technique. The mean of the cicie t.in e distribution creased with are increase of the bed load and the size of the ta.blets in ali comparative tests. The vibration (10 Hz, 8 mm amplitude) reduced the mean of the cicie time distribution by more than 10%, and also decreased its variance. The vibration ais() aí ected the maxirnum pressure drop (40% reduction) and the minimum spouting velocity The vibro spouted bed showedhigher- adhesion efficency (73 to 88%) than the non-vibrated spouted bed (66 to 79%) in ali equivalent situations and the complete coating of the smailer tablets dema.nded iess processing time due to higher surface arca circulation rate.Item Acesso aberto (Open Access) Melhoramento de tecnologia na produção e conservação do queijo marajoara(Universidade Estadual de Campinas, 1981) FINOTELO, Nemer Alfredo; BENRAADT, Rodolfo Delfino ReynaDue to the importance of buffalo milk in the manufacture of marajoara cheese, in the present work we first covered: Original and zoological classification. Officially recognized races of domesticated buffalos. Zootechnical characteristics. Aspects of buffalo's in the world with special reference to India, Pakistan, Italy and Brazil. Installations and processes related to the manufacture of marajoara cheese were studied in toco. Besides, samples commercially produced representing six production areas of Pará state, were shipped by air to Campinas; three of the production areas referred to Marajõ Island and the other three referred to inland regions. The samples shipped included the two types of marajoara cheese locally produced: IIcream" type and "butter" type. As far as composition was concerned, the samples shipped ere tested for moisture, dry matter, fat, fat in the dry matter, pH, protein, protein in the dry matter and sodium chloride. To check for possible adulteration such as by intentional addition of flour or other amilaceus products, starch determinations were carried out in alI samples. To inhibit mold growth, several concentrations of different chemical preservatives were tested in twenty four cheeses in a small plant located at Marajo Island. The preservatives were added directly to the cheese mass during the manufacture of eight cheeses. One hour after processing was completed the surface of each of the eight cheeses was treated with an insulating cover including paraffin, linseed oil, and a preparation developed by the Dairy Products Institute Candido Tostes. The surface af two Other cheeses was not treated to serve as controlo Another set of four cheeses were only treated on the surface with one of the products mentianed. Six cheeses were treated with Rhodofilm (Bayer) on the surface and six other cheeses were vacuum packed in plastic cryovac bags according to the technique described in item 6.2. Finally, at the Central Public Health Laboratory of the State of Pará using as reference, two srnall Industrial Plants, were run rnicrobiological analysis of the final product, that was conditioned in cryovac, with and without addition of Sodium Nitrate. Analysis were also done in final product without any protection, as custornarilly commercialized, to compare both, at the moment they are consurned, and in accordance with flowsheet at item 6.3.Item Acesso aberto (Open Access) Penalização e lagrangeano aumentado(Universidade Estadual de Campinas, 1981-04-03) GOMES, Hermínio Simões; MARTÍNEZ PÉREZ, José Mário; http://lattes.cnpq.br/8543703316798123Item Acesso aberto (Open Access) Metabolismo de ureídeos e asparagina durante a ontogenia do fruto de plantas de soja nodulados e não-nodulados(Universidade Estadual de Campinas, 1982) GOMES, Maria Auxiliadora Feio; SODEK, Ladaslav; http://lattes.cnpq.br/2012001011713124The synthesis and accumulation of reserve proteins in seeds require a large supply of reduced nitrogen. Generally, the transport of nitrogen from other parts of the plant involves a few specific compounds, the nature of which depends on the species and growth conditions. The fixation of N 2 by Rhizobium in symbiotic association with soybeans, cultivated in the absence of mineral nitrogen, leads to the incorporation of atmospheric nitrogen in ureides (allantoin and allantoic acid). These compounds form the main nitrogenous components found in the transport stream of nodulated soybeans. On the other hand, soybeans grown in the absence of Rhizobium and with NO3 nitrogen source, contain asparagine as the predominant as transport form of nitrogen. The accumulation of protein in the fruits of such plants will depend, therefore, on their ability to utilize these compounds for the synthesis of amino acids. The objectives of the present study were: first, demonstrate the presence of the enzymes presumed to be involved in the utilization of these compounds (i.e. allantoinase and asparaginase). Second, determine the effect of this drastic change in the transport of nitrogen from mainly ureides (nodulated plants) to asparagine (non-nodulated plants) on the appearance of these enzymes during fruit ontogeny specifically in the pods, cotyledons and teguments Asparaginase was assayed by a radiometric method, involving the separation of the product by chromatograpy. Allantoin was assayed by measuring the formation of the product by a differential method. Activity of both enzymes was found in all tissues of the fruit, except in the pod where no asparaginase activity was detected. Both allantoinase and asparaginase presented low activities in the tegument, producing only a small peak near the and of seed development, both for modulated and non-nodulated plants, In pods and cotyledons higher levels of allantoinase were found, especially during the phase of most active protein accumulation. It is noteworthy that the activity in the cotyledon was well above the rate of nitrogen accumulation. Asparaginase activity was also higher over this period of cotyledon development, although the level of activity was lower, being similar to the rate of nitrogen accumulation. A comparison of the activity patterns nodulated and non-nodulated plants reveals little difference except for a tendency for allantoinase to remain high (pod and cotyledons) over a longer period in nodulated plants. This occurred in spite of a shorter maturation period for fruits of nodulated plants. On the other, asparaginase (cotyledon) maintained high activity over a longer period in the non-nodulated plants. The possible significance of this effect was discussed in terms of the supply of ureides and asparagine to the fruits. As to the levels of ureides and amino acids in the various fruits tissues, the data show that the ureides, despite their association with nodule activity, were present in levels above that expected for non-nodulated plants. Of the fruit only the pods presented a high level of ureides (200 x) in nodulated plants compared to non-nodulated since low but similar levels were found ín the cotyledons and teguments of both plant types. It is notworthy that the level of free amino acids was generally the inverse of that for ureides, since higher levels were found in fruits of non-nodulated plants.Item Acesso aberto (Open Access) Identificação de parâmetros em modelos ecológicos(Universidade Estadual de Campinas, 1982) GUERRA, Renato Borges; MARTÍNEZ PÉREZ, José Mário; http://lattes.cnpq.br/8543703316798123Item Acesso aberto (Open Access) Propagação de ondas eletromagnéticas em meios com camadas múltiplas usando funções de Green diádicas e sua aplicação no modelamento de florestas(Universidade Estadual de Campinas, 1982) CAVALCANTE, Gervásio Protásio dos Santos; ROGERS, David Antony; GIAROLA, Attilio José; http://lattes.cnpq.br/7834721061998959Item Acesso aberto (Open Access) Desenvolvimento de um método para a análise da solidificação de metais superaquecidos em moldes cilíndricos refrigerados(Universidade Estadual de Campinas, 1983) MOREIRA, Antonio Luciano Seabra; SANTOS, Rezende Gomes dos; http://lattes.cnpq.br/8824197696621614This work presents a theoretical-experimental study on the solidification of metals, initially at a temperature above the melting point, in cooled cylindrical moulds. A literature survey was carried out regarding the heat transfer methods applied to solidification in metal/mould systems. Using a radial water cooled device simulating the solidification of cylindrical geometries, experimental values of the solidified thickness as function of time were obtained. A method was developed to analyse the solidification kinetics of superheated metals in cooled cylindrical moulds and the predictions furnished by this method were compared with the experimental data. Possible applications of the proposed method to the solution of practical problems in the foundry process 3re presented. Finally a comparative study of the solidification kinetics of solidified metals in plane, cylindrical and spherical geometries is presented.Item Acesso aberto (Open Access) Estudo analítico experimental de um conjunto gaseificador(Universidade Estadual de Campinas, 1983) MORAES, Sinfrônio Brito; ISMAIL, Kamal Abdel Radi; http://lattes.cnpq.br/2741276950055207The research subject proposed in this study is based on an examination of the parameters significant for the process of ascendent and counter-current gasification. The gasifier which was utilized was a module proto type. The lower module has an extenal diameter of 50 cm and an internail diameter of 42 cm, owing to the refractory and to the double walls designed for the heating of the incoming air. The upper module with an external diameter of 55 cm and an internal diameter of 50,6 cm, is similarly made of double walls in view of the extraction of gas being localized at different The two modules are joined to each other in such a way as to enable a variation in the height of the charging of the gasifier, as well as in the height of the outgoing gas. The process of gasification used in the study was that of air gas or low-BTU gas. The study was divided into two geometries by varying be tween them, the relation of the height of the outgoing gas and the diameter of the gasifier. When gas was extracted by the upper perforation with a relation δ = 3,09 it is denominated upper geometry andwhen δ=214, lower geometry. Five experimento involving different escapes of air were made for each of the geometries. Temperatus were measured at three different points of the gasifier in order to ascertain the behavior of the reaction zones according to the temperatures. The flows of air, gas, gasified coal and steam contained in the air were measured so that the analyses were made in terms of dimensional parameters. The composition of the gas was analyses chromografically in all the experiments undertaken, so as to determine the calorific potential of the gas, the percent of energy in each component of the resultant mixed gas, and the calorific power of the gasifier. In relation to the composition of air gas, the gasification behaved as if it were a mixture of water gas, owing to local ambiental condition. The composition presented, on analysis, parts of hydrogen and methane, thus contributing to an increase in the heating power of the gas and consequently, an increase in the heating potential of the gasifier.Item Acesso aberto (Open Access) Contribuição para o planejamento econômico de sistemas de energias elétrica: um algoritmo para a expansão simultânea da geração e transmissão usando aproximação linear(Universidade Estadual de Campinas, 1983) BRANCO, Tadeu da Mata Medeiros; KOO, Robert Liang; http://lattes.cnpq.br/0610628446391103Contribution tho the eletric power systems economic planning: an algorithm for the simultaneos expansion of generation and transmission using linear approximation. Economic Planning of Generation and Transmission in Electrical Power Systems constitutes a Nonlinear Optimization Problem which has some complexity and must be treated in a global manner. Several iteractive methods has been proposed to solve problems of this nature but sometimes are unaceptable due time and large computer storage requirements. This complexity is enlarged if generation and transmission were simultaneously optimized. Linear programming has been considered as a promissing tool to solve these problems but due the linearization of nonlinear functions the results presents some loss of accuracy, even so, for planning purposes these results are aceptable. In this work we propose a Global Algorithm for the Economic Planning of Simultaneous Expansion of Generation and Transmission in Electrical Power Systems based on the application of a Linear Programming Method and Minimum Cost Flow Algorithm which permits discret addition of generation and circuits units to the system with minimum investment cost in each period. Losses and maximum capacity of the lines are included in the algorithm, some examples are shown and at the end we suggest some extensions to further works.Item Acesso aberto (Open Access) Processos de multifonons no sulfato de níquel hexahidratado NiSO4.6H2O(Universidade Estadual de Campinas, 1983-04-24) CANCELA, Luiz Sérgio Guimarães; GUALBERTO, Gilberto de MatosItem Acesso aberto (Open Access) Aspectos computacionais da resolução de um modelo em educação(Universidade Estadual de Campinas, 1983-12-16) ESPIRITO SANTO, Adilson Oliveira do; MARTÍNEZ PÉREZ, José Mário; http://lattes.cnpq.br/8543703316798123Item Acesso aberto (Open Access) Processos de relaxação em sistemas longe do equilíbrio termodinâmico(Universidade Estadual de Campinas, 1985-08-16) MACHADO, Carlos José Freire; VASCONCELLOS, Aurea Rosas; http://lattes.cnpq.br/0475932786473160Item Acesso aberto (Open Access) Estudo experimental do secador pneumático vertical(Universidade Estadual de Campinas, 1986-02-17) FARIA, Lênio José Guerreiro de; SANTANA, Cesar Costapinto; http://lattes.cnpq.br/8458559657676452This work is related with studies on the performance of a vertical pneumatic dryer on a well instrumented pilot plant. Experiences were rea1ized with sand particles with a mean diameter of 0.46mm and 0.55mm and glass spheres with a mean diameter of 0.24mm, in a drying tube with 4m high and an inside diameter of 5.25cm, aiming the determination of the air humidity, temperature and pressure profiles along the dryer, also entrance and exit moisture contents of solids can be obtained. Psychrometers were designed to measure the air humidity above 1000e and they are used to determine the humidity and temperature profiles. It is presented a1so a dryer simulation study that utilizes a unidimensional model, where the basic of the momentum, energy and mass conservation equations for particulated systems are integrated, and a comparison between the simulated and experimental results is done.Item Acesso aberto (Open Access) Determinação entalpimétrica de cálcio e magnésio em calcários usando-se um entalpímetro de fluxo contínuo(Universidade Estadual de Campinas, 1986-03-10) MENDES, Afonso Silva; OLIVEIRA, Walace Alves deDetermination of calcium and magnesium in limestone using a flow enthalpimeter is described. The apparatus consists of a peristaltic pump, a proportional injector, two twin thermistors, a Wheatstone bridge and a strip-chart recorder. The injector, the 'flow manifolds and the emperature-sensing elqments are immersed in San insulated water bath. For the determination of calcium, preliminary studies were undertaken using the precipitation reaction with ammonium oxalate and the complaxation with Na2-EDTA and Mg-EDTA. After these studies, the experimental procedure chosen was based on complexation with Mg-EDTA. In order to test the method, determination of calcium was performed in synthetic, certified and other samples. Precision and accuracy was found to be equal to 1.0% and the analytical rate was 100 samples per hour. For the determination of magnesium, initial tests were conducted investigating the possibility of using the complexation reaction with Na2-EDTA and the previous separation of calcium by means of precipitation with ammonium oxalate and ammonium molybdate. In the final procedure, the complexation reaction with Na2-EDTA was chosen to give the amount of both calcium and magnesium. Then, magnesium is found by difference, since the percentage of calcium is known. Resuls of several determinations indicate an average error around 4% for samples with MgO higher than 10%. The uncertainty increases for samples having MgO lower than 10%. The analytical rate is about 100 samples per hour. The results of the enthalpimetric method were compared with those found by other techniques such as volumetry ( by complexation) atomic absorption and flame photometry.Item Acesso aberto (Open Access) Transferência de calor com mudança de fase em processos de borbulhamento(Universidade Estadual de Campinas, 1986-04-25) SOUZA, Célio Augusto Gomes de; ANDRADE, Alberto Luiz de; http://lattes.cnpq.br/5905831095854831Heat transfer fenomena with phase change is analyed in a bubbling process, where heated gas hubbies pass through a liquid. The experimental evaporation rate is measured with an equipment which operates with gas feed temperatures in the range of 70 to 285°C, A diffusive transient model is presented in which the simultaneous transfer effects and surface bubble superheating are taken into account to calculate heat and mass transfer coefficients and flow rates. The modeling equations are presented in the explicit form thus permitting the direct calculations of heat and mass transfer rates during the evaporation of a liquid and the testing the predicted values with experimental results. A comparison between the simultaneous and the superheating models showed that at higher gas temperatures and higher residence times , both modeIs reproduce satisfactorily the operational conditions. in order to verify the equipment performance to obtain the bubbling time needed for the attainment of steady state, the liquid equilibrium temperature was theoretically calculated taking into a account the simultaneous and the superheating effects, being these results compared with the experimental values.Item Acesso aberto (Open Access) Métodos de projeção de convergência finita para sistemas lineares e quadrados mínimos(Universidade Estadual de Campinas, 1987-03-20) GUERRA, Renato Borges; MARTÍNEZ PÉREZ, José Mário; http://lattes.cnpq.br/8543703316798123Item Acesso aberto (Open Access) Influência dos frutos sobre a fixação de nitrogênio em soja (Glycine max L. Merril) cv. Santa Rosa(Universidade Estadual de Campinas, 1987-03-25) GOMES, Maria Auxiliadora Feio; SODEK, Ladaslav; http://lattes.cnpq.br/2012001011713124The main objective of this study was to obtain information on the relationship between reproductive development and nodule activity. For this purpose, we used nodulated soybeans induced to flower at different ages. The plants were grown in vermiculite with a nutrient solution deficient in nitrogen, and maintained in a greenhouse. Flower induction was carried out at the V2, V5 and V8 stages of development. Other treatments included the removal of flowers and the maintenance of plants in the vegetative state by growing them under long-day conditions. Measurements of nitrogen fixation were made with an intact plant system, which allows the use of the same plants throughout the growth cycle. When these measurements required the simultaneous quantification of nodule number and weight, a detached root system was used, where the shoot was sectioned immediately before the measurements. The intact and detached root systems gave similar activities for nitrogenase, showing that one system is just as reliable as the other. One advantage of the intact system is the possibility of using the same plants throughout the growth cycle. Of the experiments set up, two were carried out in the summer, where plants induces in the V2 and V5 stages produced activity curves with similar profiles and these for independent of the stage of reproductive development. This conclusion was confirmed by the data of the other treatments where fruits were removed and plants maintained vegetative under long days, since such treatments did not modify the nitrogenase activity curves. In another experiment, carried out in the autumn, plants induced at V2 and V5 produced peaks of activity at different ages corresponding to the reproductive phase, or specifically to the pod-fillinq stage. Therefore, under the conditions of this experiment at least, a clear relationship was obtained between the presence of fruits and the fall in nitrogenase activity. The different behaviour of the plants in this experiment compared with the others may be due to the less favorable conditions of light and temperature. The main conclusion reached was that the competition between the fruits and nodules for photosynthates in soybeans is not the main reason for the fall in nitrogenase activity, although it could be in less favorable conditions.