Browsing by Issue Date, starting with "2014-07-29"

Filter results by year or month

Now showing 1 - 20 of 16897

Estudos de atividade antimicrobiana, de migração e de toxicidade de nanopartículas de prata aplicadas em filmes poliméricos
(Universidade Federal de São Carlos, 2014-07-29)
Becaro, Aline Aparecida
;
Corrêa, Daniel Souza
;
https://lattes.cnpq.br/0461451015026948
;
https://lattes.cnpq.br/1283081812633332
Advances in nanotechnology have allowed the development of materials that can perform various technological functions. Among these materials, polymers have been noticed for innovation for food packaging, providing physical protection combined with antimicrobial activity, especially in the case of polymer additives with silver nanoparticles, which increase the time of shelf life of foods. In this context, the aim of this study was to evaluate the potential application of polymeric additives films with silver nanoparticles (AgNPs) for use in foods, analyzing toxicity in vivo and in vitro AgNPs in living organisms, defining the risks and benefits of the particles and for the product user, considering the possibility of migration of these to the environment. Nanoparticles were synthesized with varying size and shape and used for application in films. Several techniques were used to characterize the films and AgNPs. All tests using organisms followed established protocols. The results showed that the studied films showed good microbial activity at all concentrations for both microorganisms S. aureus and E. coli. The films also showed that can be used as food packaging maintaining desirable qualities chemical treasury consumers of minimally processed carrots. In the migration tests performed on the films was not observed even studied the possibility of migration of AgNPS at the lowest concentrations (2.5) have been reported in that they may migrate to other conditions at relatively low concentrations literature and as demonstrated in the tests toxicity to aquatic and terrestrial organisms there is potential risk of interfering with the survival and mobility of aquatic invertebrates fresh and salt water and algae, as well as can also interfere with the development of rat pups when ingested orally and causes changes cyto and genotoxic in organisms such as Allium cepa.
Animação estereoscópica: relações entre a tecnologia audiovisual e a percepção da profundidade
(Universidade Federal de São Carlos, 2014-07-30)
Santos, Tiago Eugenio dos
;
Andrade, Leonardo Antônio de
;
https://lattes.cnpq.br/3921612856948891
;
https://lattes.cnpq.br/2248690766230203
The stereoscopic application is not in itself a technical novelty, because, already in 1838, the first device that allowed the stereoscopic display is designed. In the early years of its invention new apparatus were constructed in an attempt to combine animation with stereoscopy. The 1910s and 1920s are marked by the beginning of the use of stereoscopy in the cinema and at the end of the 1930s in film animation. Since then, there have been periods of great productivity alternated by periods of relative calm. Today, we live in a time in which stereoscopy comes back to matter in the film scene, especially in animated films. This research builds a historical overview of stereoscopy, stereoscopic cinema and stereoscopic animated film. It also exposes the particularities of a stereoscopic audiovisual piece and discusses the specifics of the application of stereoscopy in animated films. Using as reference periods of stereoscopic film according to the author Ray Zone, this research aims to analyze the use of stereoscopy in animations from different historical periods. The selected works for the analysis are: Motor Rhythm (1952), Starchaser: The Legend of Orin (1985) and Brave (2012). In order to verify the implementation of stereoscopy and the role of parallax in the pieces chosen, an analysis methodology was developed so that we could be able to determine the application of stereoscopy within an audiovisual work while also addressing its narrative composition.
Catalisadores derivados de óxidos do tipo perovskita LaMO3, LaMFeO3 e LaMO3/γ-Al2O3 (M = Co, Ni ou Fe) aplicados à reforma a vapor de etanol
(Universidade Federal de São Carlos, 2014-07-30)
Faustino, Patrícia Brígida
;
Assaf, José Mansur
;
https://lattes.cnpq.br/9563312407691130
;
https://lattes.cnpq.br/6807169442685729
The hydrogen production has been extensively studied as a clean and powerful energy source, indicating that in the future hydrogen will became a key component for the global energy production, since burning fossil fuels, used nowadays, emits disturbing amounts of gases that cause the greenhouse effect and the global warming, which urgently needs to be reduced. Thus, hydrogen use has been studied as electric power generation and as a fuel derived from, for example, fuel cells that are able to convert chemical energy from the reaction between H2 and O2 into electrical energy, thermal energy and water, without causing environmental impacts, since it has no noises or vibrations and there is neither combustion or emission of particulates. A feasible way to produce hydrogen is the Steam Reforming Reaction of ethanol, since ethanol is a renewable source obtained mainly from sugar cane and also due to the low costs of operation in the Steam Reforming Reaction. Due to these facts, the reactions of Steam Reforming of Ethanol (SRE) have been extensively studied in previous years, and several studies have shown that this reaction provides a high hydrogen production; however, some parallel reactions may occur, forming side products, leading to reduced amounts of produced H2. Thus, the development of appropriate catalysts in these reactions becomes necessary, in a way that it enhances the conversion favoring the major product and suppressing the conversion to side products. A good efficiency of perovskite type oxides as catalysts in the SRE has been reported in several studies. These materials are mixed oxides with an ABO3 chemical structure, A being the largest cation such as alkali metals, alkaline earth metals and rare earth elements, and B representing the smallest cation such as transition metals. The partial substitution of cations located in the B site by others with similar oxidation state can promote changes in the redox properties of these ions, causing changes in the stability of the crystal structure. Therefore, the perovskite type oxides LaNiO3, LaCoO3 and LaFeO3 were synthesized through the citrate and precipitation methods. In a second stage Fe was added into the structure of the oxides LaNiO3 and LaCoO3, and in a new stage LaNiO3, LaCoO3 and LaFeO3 was synthesized with perovskite type oxides supported on gamma alumina by precipitation-deposition. After the syntheses, the catalysts were characterized and the influence of the preparation method was studied, specifically the effect of Fe addition and of the support presence, in relation to the activity of the catalysts in the reactions of steam reforming of ethanol for hydrogen production. The experimental results showed that the LaCoO3 catalyst synthesized by precipitation method was more active and stable than the others, although the LaNiO3 (citrate and precipitation) and LaCoO3 (citrate) catalysts had also been active in SRE. The material LaFeO3 showed to be inactive in the reaction. The Fe addition in the catalysts LaNiO3 and LaCoO3 structure did not significantly alter their catalytic performance, indicating an economically advantageous feature, since iron is a cheaper metal than cobalt and nickel, and may partially replace these elements in the catalyst formulation, thus decreasing the synthesis cost without compromising the hydrogen yields. The use of gamma alumina as support in the SRE favored materials with higher specific surface area, whereas it did not favor a higher activity or stability of these catalysts, however the activity was maintained.
Bioacumulações de Cd, Ni, Pb e Zn durante os crescimentos de Salvinia minima e Lemna valdiviana
(Universidade Federal de São Carlos, 2014-07-31)
Iha, Danilo Sinhei
;
Bianchini Júnior, Irineu
;
https://lattes.cnpq.br/0659731944736389
;
https://lattes.cnpq.br/2332539900317166
Metals are dispersed easily in environments and are bioconcentrated in tissues of many organisms causing risks to the health and stability of aquatic ecosystems even at low concentrations. The use of plants in phytoremediation has been evaluated in order to mitigate environmental contamination since it has large capacity to adsorb and/or accumulate metals. This study evaluated the growth and phytoremediation of Salvinia minima and Lemna valdiviana grown in different concentrations of Cd, Pb, Ni and Zn. The growths were determined through measurements of leaf area by photographic images. The cultures were performed in a continuous flow (residence time = 2 days), under controlled temperature (23 ºC) and photoperiod (12/12h; radiation intensity: 4.31x10- 3 μmol sec-1 cm-2). The selected concentrations were 0.003 0.030 0.300 and 0.600 mg L-1 Cd; 0.020 0.200 and 0.400 mg L-1 Ni; 0.01 0.10 and 1.00 mg L-1 Pb and 0.10 1.00 10.0 100.0 and 1,000.0 mg L-1 Zn. The metals selection derived from the difficulty of its removal by conventional methods, and the selection of concentrations was based on values toxic to humans and on the maximum values allowed by Brazilian legislation for effluent discharge. None S. minima growth in concentrations of 0.300 mg L-1 Cd and 10.0 mg L-1 Zn were observed. L. valdiviana showed no growth when cultured at concentrations of 0.600 mg L-1 Cd; 0.10 and 1.00 mg L-1 Pb; and greater than 100.0 mg L-1 Zn. Individuals of S. minima bioaccumulated maximum 0.803 mg g-1 Cd; 0.677 mg g-1 Ni; 1.786 mg g-1 Pb and 10.464 mg g-1 Zn. L. valdiviana bioaccumulated maximum 1.15 mg g-1 de Cd; 0.045 mg g-1 de Ni e 62.465 mg g-1 de Zn. The metals content in plant tissues increased and the growth coefficients decreased when progressively increased the Cd, Pb and Ni concentrations. We conclude that, depending on the concentration, the two species of macrophytes can be used to phytoremediate effluents with metals and S. minima is more efficient on Ni, Pb and Zn removal and L. valdiviana on Cd removal. The Cd and Ni concentrations allowed by Brazilian law were toxic for both species and the allowed Pb concentration were toxic for Lemna valdiviana.
Previsão da contração e da variação dimensional em componentes injetados através de simulação computacional
(Universidade Federal de São Carlos, 2014-07-31)
Kiam, Thyago Morette
;
Lucas, Alessandra de Almeida
;
https://lattes.cnpq.br/9754332336954137
;
Pessan, Luiz Antonio
;
https://lattes.cnpq.br/8276650236213537
Both, average linear shrinkage and dimensional variation behavior for injection-molded components influence its final application performance, hence the project overall quality and profit [1]. The use of simulation software for estimating dimensional variation is still incipient due to some factors such as lack of proficient users, code simplifications and lack of raw material proper characterization. On the Brazilian context, this third item is particularly critical, once the coefficients for warpage results improvement for the main commercial code available on the market, Autodesk Moldflow Insight (AMI); requires a very specific characterization named ‘corrected residual in-mold stress’ (CRIMS), just generated by the software developers in a quite complex and low cost-benefit process for national resin suppliers. The present work used computational experimentation based on commercial code AMI 2013 aiming both: to generate CRIMS coefficients from correlation studies involving optimization algorithm, based on Cellere and Luchetta work [2]; and to perform a case study proposing a method that make use of optimization algorithm and Monte Carlo Simulation in order to drive both, design and process decisions; in the end providing a estimative of the dimensional variation behavior on early design and mold development phases. The results level of error obtained with the CRIMS coefficients generated on this work is close to the results generated from coefficients generated by the supplier for the same material (confidential data) that represents the state-of-the-art of correction coefficients generation; confirming the potential for the method showed in this work. The adaptable nature of the method described on Cellere and Lucchetta paper [2] was maintained.
Incorporação da sustentabilidade em cadeias de suprimentos: práticas estabelecidas e barreiras encontradas
(Universidade Federal de São Carlos, 2014-07-31)
Nascimento, Annelise Mendes
;
Alcântara, Rosane Lúcia Chicarelli
;
https://lattes.cnpq.br/9931944429943729
This research aims to present and analyze the practices that can be established by focus companies with their suppliers, distributors and consumers, so that sustainability is embedded in their supply chains. Moreover, as a way to better understand the dynamics of sustainability, the research also analyzes the barriers faced by organizations when adopting this type of practice. From the information obtained by the technique of systematic literature review, we developed a questionnaire for the empirical stage of this research - a survey with organizations known for adopting sustainable practices. Among the results, it is emphasized that the practices aimed at environmental issues are further explored, both in literature and empirically. Regarding the practices with suppliers, those that require a lesser degree of involvement between companies - less collaboration - and had a more assessment nature stood out. Considering the chain downstream, practices among distributors are still poorly known, both in literature and empirically; and practices that stood out with consumers referred to the sharing of information, and labeling of products. Considering the barriers, the more relevant indicated by respondents was the cost. From the results obtained, proposals were outlined, both theoretical and practical, about the incorporation of sustainable practices throughout the supply chain, and how to overcome potential barriers. It is believed that these proposals can be a starting point for further academic research, and still be used by managers interested in the sustainable management of their organizations.
Sinterização em forno de micro-ondas da hexaferrita de bário dopada com cromo
(Universidade Federal de São Carlos, 2014-08-01)
Castro, Walter da Silva
;
Kiminami, Ruth Herta Goldschmidt Aliaga
;
https://lattes.cnpq.br/7643216999108223
;
https://lattes.cnpq.br/8869551828488378
Barium hexaferrite (BaM) is a magnetic ceramic material with a hexagonal crystal structure, which is widely used as a permanent magnet and in electronic devices, magnetic recording media, electromagnetic wave absorbers, etc. The properties of barium hexaferrite are strongly dependent on its composition, type of doping agents, and processing variables. Chromium oxide is an antiferromagnetic material, which, when used as a dopant in barium hexaferrite, can increase the latter s saturation magnetization and decrease its coercivity, making it suitable for use in magnetic recording media. The literature reports on several studies about the effect of the addition of dopants on barium hexaferrite sintered in a conventional furnace, aiming to improve its magnetic properties. However, no studies so far have focused specifically on microwave-sintered chromium oxide-doped barium hexaferrite. In this work, a commercial barium hexaferrite was mixed with chromium oxide ranging from 0 to 3g. Each mixed powders were pressed isostatically at 200 MPa and sintered in a conventional furnace (60 min) and a microwave oven (30 min) at 1100, 1200, 1240 and 1280oC, applying heating rates of 10oC/min and 50oC/min, respectively, to obtain highly dense materials with small grain sizes. The resulting materials were characterized by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), specific surface area by the BET method, apparent density, scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). The results indicated that sintering barium hexaferrite microwave with and without the addition of chromium oxide yields materials with a homogeneous microstructure and densities similar to those obtained by conventional sintering, which can be achieved in an 80% shorter firing time. At 1280oC, the microwave sintered BaMCr4 sample exhibited higher levels of saturation magnetization and remanence than those of the other samples conventionally and microwave sintered at this temperature.
Síntese e sinterização de pós-compósitos de aluminaboretos de alta dureza por moagem de alta energia
(Universidade Federal de São Carlos, 2014-08-04)
Cerqueira, Valdívio Rodrigues
;
Morelli, Márcio Raymundo
;
https://lattes.cnpq.br/0172837599844991
;
https://lattes.cnpq.br/0169289640534560
This work was aimed to obtain powder composite mixtures of ceramic phases with high hardness through high energy ball milling synthesis and characterization of sintered samples in terms of hardness. In an exploratory phase, many aluminothermic reactions were obtained from basic or precursors oxides such as WO3, TiO2, B2O3, Ti °, B ° and C, whose final products were B4C-TiB2-Al2O3 Al2O3 and (WB or WB2 or W2B5) - TiB2. The resulting powders from the processing of synthesis performed under different conditions were characterized employing the following techniques: X-ray diffraction (XRD), real density, X-ray fluorescence (XRF) and scanning electron microscopy (SEM). Two reactions were selected, where the powders were subjected to variation of milling time of high energy and disintegration procedure change. Samples of the powder were forming under uniaxial pressure of 50 MPa followed by isostatic pressure of 200MPa and sintered at 1600 °C, 1650 °C and 1700 °C under high vacuum aiming to characterize the microstructural evolution and microhardness Vickers. Thus, the results showed that the composite powder represented by Al2O3 - WB - TiB2 sintered at a temperature of 1700 °C allow to obtain apparent densities (% TD) and Vickers hardness, near 99% and 19 GPa respectively. The best results characterized by the density, microstructure and hardness were obtained by enhancing the grinding in ball mill and additional deagglomeration in planetary mill after high energy milling.
Efeito da adição de boro na microestrutura e na resistência ao desgaste do aço inoxidável AISI 430 conformado por spray
(Universidade Federal de São Carlos, 2014-08-04)
Nascimento, Alexandre Romão Costa
;
Bolfarini, Claudemiro
;
https://lattes.cnpq.br/9231627080617037
;
https://lattes.cnpq.br/7480615370794070
The contact between drill pipes during oil well exploitations induces a severe wear process that might cause well bore pipe wall rupture, fluids leakage, environmental impacts, and possibly fatal accidents. The problem is known by the oil and gas industries since the 1930 s and several solutions have been proposed by researchers and engineers in order to mitigate its deleterious effects. A method that grows popular in the industrial media is the execution of large-scale tests that consists in forcing a cylinder against the inner wall of a pipe. During this test, in order to reproduce operations conditions, the use of drilling mud as a lubricant and a wear resistant coating over the cylinder are both possible. The purpose of this work was to evaluate the effect of boron addition on the microstructure of spray-formed AISI 430 stainless steel as well as in its wear resistance in a condition comparable to the one observed during drill pipes contact. It was then necessary to develop a wear tester capable of reproducing the changes in the contact areathat occurs during the aforementioned contact. The results showed that unlike the conventional API 5L X80 steel, the spray-formed material s wear rates were constant as predicted by Archard s wear law. Despite the different wear rate behaviors, the generated wear debris showed a similar morphology in all tested materials. The tribossystem conditions induced a plastic ratchetting wear mechanism. In the light of Greenwood and Williamson s theoretical model, it was concluded that the observed changes in the wear rate on conventional steels was due to slow changes in the plasticity index which happens much more quickly in the sprayformed steels due to the presence of intermetallic borides. Moreover, considering the established test parameters, the increase in the boron content also increases the AISI 430 steel s wear resistance, since the increase in the area fraction of intermetallics decreases the rate at which metallic asperities contact each other during the test.
Programas de diversidade de recursos humanos: uma análise sobre sua adoção no Brasil
(Universidade Federal de São Carlos, 2014-08-04)
Reith, Stefanie Landim
;
Rachid, Alessandra
;
https://lattes.cnpq.br/6981682198988902
;
https://lattes.cnpq.br/3311563561943550
The purpose of this master´s degree thesis is to analyze the adoption of diversity programs for inclusion of women and blacks in companies in Brazil. We chose to conduct the survey on companies listed on the ranking "Melhores Empresas para Você Trabalhar" (Best Companies to Work For), in which they participate for human resources management practices evaluated as advanced. Few companies have diversity programs, but more than indicated by the literature review. Most programs are in initial stages. It was also possible to observe the relationship of the adoption of these programs with the size and origin of the capital of the companies surveyed.
Composição de espécies de lianas e sua resposta ao corte em um fragmento de floresta estacional semidecidual, Araras, SP
(Universidade Federal de São Carlos, 2014-08-04)
Rocha, Elisangela Xavier da
;
Penha, Alessandra dos Santos
;
https://lattes.cnpq.br/9799774247477252
;
https://lattes.cnpq.br/3486794494112864
Although the knowledge on plant richness of seasonal semideciduous forests has been increased during the last years, we have little information about the composition of lianas species in these phytophysiognomies, especially if one consider the small and degraded ones. In this sense, we sampled the species of lianas, and also their abundances and mechanisms of climbing in a 12.8 ha seasonal semideciduous forest fragment located at Centro de Ciências Agrárias (CCA), University of São Carlos (UFSCar), Araras, São Paulo, southeastern Brazil (22º18 00 S and 47º23 03 W). During one year (from March 2013 to March 2014) we registered the liana species through unsystematic hikes in the area. We found 34 species of lianas (14 families and 23 genera). Sapindaceae and Bignoniaceae were the families with the greatest species richness, eight species each one. We classified Serjania caracasana and S. laruotteana (Sapindaceae) as abundant because they occurred throughout the forest area. On the other hand, we found that Schnella microstachya (Fabaceae), Tynanthus fasciculatus (Bignoniaceae), and S. tristis were considered as rare . Species of lianas with tendrils were the most common in the community (64%), followed by the fickle lianas (24%) and the scandent ones (12%). Although small, degraded and isolated, we argued that these forest communities might present a great part of lianas richness, once they have ecosystem features that favor this life form. These findings may represent the basis for the proposition of management routes of the seasonal semideciduous forests; for example, if one should choose between the selective management of lianas or their unrestricted cutting in such ecosystems.
Influência da adição de Nb, Ti e Zr nas propriedades de fluência da liga HP fundida por centrifugação
(Universidade Federal de São Carlos, 2014-08-05)
Andrade, Antonio Rafael de
;
Bolfarini, Claudemiro
;
https://lattes.cnpq.br/9231627080617037
;
https://lattes.cnpq.br/3878393158100376
This work aimed to evaluate the influence caused by Nb single addition and by Nb-Ti and Nb-Zr combined addition in the high temperature mechanical properties of a centrifugally cast HP alloy. Particular investigation was carried out on creep and hot tensile properties in the temperature range between 900 to 1100 oC. Seamless tubes were casted by horizontal centrifugal process with the following nominal composition 0.50C-25Cr-35Ni, 0.50C-25Cr-35Ni-1Nb, 0.50C- 25Cr-35Ni-1Nb-0.1Ti e 0.50C-25Cr-35Ni-1Nb-0.1Zr. These 04 alloys were evaluated using the following techniques differential scanning calorimetry (DSC), optical and electron microscopy, energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The mechanical characterization was performed by elevated temperature tension tests with 3 different strain rates and constant load creep rupture test in the stress range of 65 to 15 MPa and comprising rupture times between 10 to 2000 hours, with or without extensometer using. The results were interpreted using classical methodologies (Norton, Arrhenius, Monkman-Grant, Larson-Miller, and others). The results shown that these elements addition did not change significantly the macrostructure, but they played an important role on formation, fragmentation, size, quantity, distribution, coarsening and coalescence on the carbides in the microstructure. Additions also refined the dendritic arm space. These microstructural changes led to a different mechanical behavior in each alloy. In the elevated temperature tension tests the Nb addition led to the highest values for mechanical resistance. On the other hand, Nb-Ti and Nb-Zr addition presented the highest time to rupture in creep tests, but in opposite conditions of temperature and stress.
Influência da adição de BaTiO3 nas propriedades estruturais, elétricas e anelásticas de cerâmicas piezoelétricas de Bi0,5Na0,5TiO3-BaTiO3
(Universidade Federal de São Carlos, 2014-08-07)
Diaz, Julio Cesar Camilo Albornoz
;
Silva Junior, Paulo Sergio da
;
https://lattes.cnpq.br/7418621942217628
;
https://lattes.cnpq.br/5796421075622433
Motivated by the great growth presented in the last decade in research on lead-free piezoelectric ceramics and the fact that some ceramic systems, as those based on bismuth, have been identified as promising candidates to substitute the lead zirconate titanate (PZT) in their present technological applications, was proposed as the objective of this work, study the effect of adding 𝐵𝑎𝑇 𝑖𝑂3 (BT) on the structural, electrical and anelastic properties exhibit by the system (1−𝑥)𝐵𝑖0.5𝑁𝑎0.5𝑇𝑖𝑂3−𝑥𝐵𝑎𝑇 𝑖𝑂3 (BNT-BT). The structural characterization was performed by the techniques of X-ray diffraction (XRD) and Raman spectroscopy. The morphological and compositional aspects (qualitative), in the calcined powders, and the sintered samples were studied by scanning electron microscopy (SEM). The ferroelectric and dielectric character of the compositions were obtained through characterization of ferroelectric hysteresis exhibit and using the technique of electrical impedance spectroscopy, respectively. Phase transitions and the possible mechanisms of anelastic relaxation were studied by the technique of mechanical spectroscopy. Samples were obtained by the method of solid state reaction, where it was possible to obtain compositions with 0.00 ≤ 𝑥 ≤ 0.08 with relative density greater than 95% and without the presence of spurious or secondary phases. On profiles of X-ray diffraction for the different studied sintered compositions was applied the method of Rietvelt refinement which allow the determination and confirmation of the crystal structures in the samples under study, and the presence of a morphotropic phase boundary (MPB) for the BNT-BT. The XRD results were corroborated by the results of Raman spectroscopy. The ferroelectric nature of the different compositions of BNT-BT system studied was confirmed. Electrical phase transitions (F-Af and Af-P) and structural transitions (R-T and T-C) exhibited by the BNT-BT were characterized by mechanical spectroscopy (using a dynamical mechanical analyzer (DMA)), and by electrical impedance spectroscopy, employing the results in complementing the electrical and structural phase diagram of this system. In addition to the phase transitions obtained, the technique of mechanical spectroscopy for compositions between 0.00 ≤ 𝑥 ≤ 0.03, allowed the observation of a complex process of anelastic relaxation that was associated with interactions and mobility of different defects present, which possibly contribute significantly to an increase of conductivity in these materials, which had not been previously reported in the literature.
Recuperação de fosfolipídeos residuais do farelo desengordurado de soja
(Universidade Federal de São Carlos, 2014-08-07)
Siqueira, Paula Fernandes de
;
Tardioli, Paulo Waldir
;
https://lattes.cnpq.br/0808991927126468
;
https://orcid.org/0000-0002-5011-9881
;
Giordano, Raquel de Lima Camargo
In soybean processing industry, oil extraction with hexane generates defatted meal. Next, soybean protein concentrate (SPC) production from the defatted meal by using ethanol solution generates alcoholic micelle as a byproduct. Following stages of ethanol recovery and concentration of that micelle, a sugared product called soybean molasses is produced. Observations of the presence of a viscous fraction (precipitate) in storage tanks of alcoholic micelle were the reason of this study which aimed at recovery of that phospholipids-rich material, main components of lecithin which presents high value in the market of soybean derivatives. So, the work was divided into three stages: development of technology, laboratory testing, and industrial testing. First of all, an analytical method by liquid chromatography for quantification of phospholipids was developed and validated. Next, assays in laboratory scale were worked out in order to evaluate the efficiency of phospholipids extraction from soybean defatted meal in different solvent systems, besides studying the behavior of each phospholipid in the system of solvent selected and the correlation between phospholipid extraction and protein concentration. The extraction process of residual phospholipids from defatted meal was studied by using varied mixtures of solvents. The following yields were obtained, in % (m phospholipids/m meal): 0.42 ± 0.01 (Hexane), 1.44 + 0.03 (Hexane: Ethanol 4:1), 1.08 ± 0.07 (Chloroform: Methanol 2:1), 1.48 ± 0.01 (Ethanol 75% v/v). As the extraction with 75% ethanol was the most efficient, the ethanol system : water was more deeply studied, because that is also the system used in SPC production. By varying the ethanol concentration, the best condition of extraction (70% v/v ethanol) enabled a recovery of 1.53 ± 0.02% (m/m) of phospholipids in the extract and 71.69% (m/m) of protein in solid fraction. Solubility of phospholipids was also tested in aqueous ethanol and remained between 0.499 g/L in 50% ethanol (v/v) at 25oC and 6.225 g/L in 90% (v/v) ethanol at 75oC. At last, industrial tests were carried out, in order to observe the production of material from actual conditions of process. Tests carried out were on micelle centrifugation and gum recovery (lecithin), and on drying of material obtained in continuous drier, besides analytical and commercial assays of the product, pure or as component of chocolates. It was possible to obtain a lecithin within commercial specifications, with high quality, and a yield of recovery of approximately 18.7 g lecithin to each kilogram of dried defatted meal. Results from this work showed the possibility of utilization of a residue from the soybean protein concentrate present in residual alcoholic micelle of the process.
Polímeros de hidrogéis com água de reúso e de abastecimento no desenvolvimento de mudas de espécies arbóreas da floresta estacional semidecidual
(Universidade Federal de São Carlos, 2014-08-07)
Ferreira, Alexandre José Domingues
;
Penha, Alessandra dos Santos
;
https://lattes.cnpq.br/9799774247477252
;
https://lattes.cnpq.br/6154403932271449
The seasonal semideciduous forests from southeastern Brazil have high plant species richness, but have been strongly affected by human interferences, which let them very degraded: nowadays they are represented by small isolated fragments, immersed in a landscape dominated by agriculture and large urban centers. In this sense, the ecology of restoration arises in order to facilitate, accelerate and direct the processes of secondary succession to manage such areas, considering the knowledge about theoretical concepts that aim to review the effectiveness of natural ecosystem management techniques and practices. In such a perspective, we aimed in this experiment to test the following question: During de production of seedlings of the native forest tree species, Ceiba speciosa (Malvaceae) and Handroanthus heptaphyllus (Bignoniaceae), different dilutions of hydrogel associated to irrigation with reused water, could improve their development? To answer this question, we selected three treatments (1g, 4g and 8g of hydrogel), beyond the witness (no hydrogel). The seedlings of both species were irrigated during one month with water reused and water supply. After this period, we estimated the growth of seedlings: roots, height and diameter. We used ANOVA (p = 0.001), and Tukey s test to verify significative differences between the mean of the treatments. We found significative differences in both height and diameter growth from 4g of hydrogel as to C. speciosa as H. heptaphyllus. In relation to the growth of root system of both tree species, the mean of superficial root area differed significantly from 4g of hydrogel when compared to the witness, confirming our initial assumption that the roots would grow in a lower proportion of area because they are in their hydric comfort zone. With such results added to theoretical knowledge in the ecology of restoration, the association of hydrogels with reused water comes to stand up for the sustainable use of water in the irrigation of native seedlings.
Reações de adição conjugada de indóis e oxindóis empregando organocatálise
(Universidade Federal de São Carlos, 2014-08-07)
Silva, Rodrigo César da
;
Paixão, Márcio Weber
;
https://lattes.cnpq.br/3773908504964104
;
https://lattes.cnpq.br/3123398279809365
Organocatalysis has emerged as a powerful synthetic tool which accelerated the development of new methods to obtain symmetric and asymmetric molecules. Furthermore, the use of small organic molecules such as amino acids derivatives, ureas, thioureas and squaramides are the leading characters in this area. In the present work, we designed a new class of organocatalysts, acting as hydrogen bond donors activation mode and subsequently catalytic activity was evaluated in the Michael addition type reactions of indoles to nitrostyrene. The synthetic route for obtaining the organocatalysts was extremely short, providing the product in just a single synthetic step in excellent yields. (CONTINUA...)
Otimização do processo de soldagem por fricção por ponto (FSpW) de soldas de materiais similares e dissimilares de ligas leves
(Universidade Federal de São Carlos, 2014-08-07)
Piccolo, Debora Regina Gastaldi
;
Alcântara, Nelson Guedes de
;
https://lattes.cnpq.br/3123107570992184
;
https://lattes.cnpq.br/3586398504200450
Currently there is a lot of pressure in the aeronautical and automobilistic transport section in order to reduce the fuel consumption and consequently cost and gas emissions. This measure has increased in the last years the use of light alloys, as the alluminium s alloys and of more efficient methods for joining them. Nevertheless, there is some difficult in joining these alloys using the conventional methods. The Friction Spot Welding (FSpW) is a solid state joining technique, that has great advantages regarding others joining techniques, and therefore could be a viable alternative to replace the established technologies as Resistance Spot Welding (RSW) and riveting, which are widely used by the automotive industry. The present works aims to study, through the Friction Spot Welding process (FSpW), the similar welding conditions of AA5754-H111 aluminium alloy and also the dissimilar welds between AA5754-H111 aluminium alloy and AZ31-O magnesium alloy. The influence of process parameters over the microstructure and the mechanical properties of the welded joints, as well as, the optimization of the welding process were evaluated. The joints were produced in overlap configuration through a different combination of parameters, which were established by statistical methods for design of experiments, and later submitted to mechanical and metallurgical characterization. The results proved the feasibility of joining the similar and dissimilar plates of aluminium AA5754 and magnesium AZ31 through FSpW process. The similar joints showed great results of shear strength. However, in the dissimilar joints, the utilization of a zinc interlayer, in spite of leading to a great superficial finishing, didn t effectively decrease the amount of intermetallic compounds formed in the joint as it was expected, leading to low values of shear strength.
Regulamentar para quê(m)? As representações sociais de prostitutas sobre a regulamentação da "profissão"
(Universidade Federal de São Carlos, 2014-08-07)
Afonso, Mariana Luciano
;
Scopinho, Rosemeire Aparecida
;
https://lattes.cnpq.br/4770451465556845
;
https://lattes.cnpq.br/4148954960536963
The general theme of this research is prostitution, known by common sense as the "oldest profession in the world", and always surrounded by much controversy, both nationally and internationally. Historically, the states are divided between their prohibition or regulation. Some social groups claim that prostitution should be regulated and recognized as a "job like any other," while others consider its exercise as a form of exploitation and commodification of the female body and expression of unequal power relations between men and women. Nationally, prostitution is already included in the Brazilian Code of Occupations, indexed with number 5198-05 in the category of "service provider". The Brazilian Penal Code does not criminalize the prostitutes, but punishes pimping. Since 1997 four law projects were shown to regulate prostitution, after many discussions, however, did not come to a conclusion about them, which seems to reflect the divergences in society about the subject. In 2012, Jean Wyllys proposed PL 4211/2012 which is currently in progress. In this interim, we propose to investigate what the main affected, the prostitutes themselves, think about the question. The theoretical and methodological framework is the Theory of Social Representations. The empirical field where this research was conducted is the central area of Sorocaba (SP), the region is historically known for sheltering prostitution. The subjects of this research are seven low-income prostitutes that exert their activity on the streets of this area. To understand the social representations of the subjects, direct observations were made and registered in a field diary and in-depth interviews, with semi-structured script were conducted. Institutions of the city with close contact with these women have been mapped: One of the Security Councils of Sorocaba, composed by tradespeople and police, one religious association, that is wing of the Catholic Church, and one Non- Governmental Organization (NGO), which works with Damage Reduction policy. Interviews with representatives of these institutions were conducted and documents produced by them were analyzed. To further understand the national context in which the theme is located, the content of the law projects, and the forces against and in favor of regulation were investigated, especially between State, Church, and social movements. It s concluded that the social representations of prostitutes are far from these speeches, and it s anchored in their own experience. They didn t know the particularities of each one of the law projects and they are against the regulation of prostitution.
Análise de um método de elementos finitos com interface estabilizada para a equação de advecção - reação
(Universidade Federal de São Carlos, 2014-08-07)
Leiva, Rosalia Taboada
;
Rodrigues, Savio Brochini
;
https://lattes.cnpq.br/1302085627916721
;
https://lattes.cnpq.br/4849264231932809
In this study we present an interface stabilised finite element method for the scalar advection-reaction equation... (CONTINUA - VER NO PDF)
Laminação em atmosfera inerte de ligas à base de magnésio para armazenagem de hidrogênio
(Universidade Federal de São Carlos, 2014-08-08)
Lago, Milton Luis do
;
Ishikawa, Tomaz Toshimi
;
https://lattes.cnpq.br/5726055117451807
;
https://lattes.cnpq.br/7895347968659345
In recent decades, the use of energy presented strong growth due to the need of supplying the daily energy consumption of approximately seven billion people. To solve this problem, it has been investigated the nature, alternative energy sources which respect the environmental issues, to provide social and technological development without negative impacts on the environment. Several processing routes have been investigated in recent years in order to overcome the obstacles of storage and availability of hydrogen as a clean, safe, cost effective and of easy manipulation energy source. The solid state reaction of magnesium and hydrogen gas produces the magnesium hydride compound which provides safe manipulation, high volumetric and gravimetric densities when compared to other traditional forms of storage (liquid or gas), coming out to be promising for being used on an industrial scale as energy carrier for mobile application. However, conventional processing routes produce a material which requires the use of high temperatures during cycling, as well as low speed of the kinetics of absorption and desorption of hydrogen gas, which limits its possibility of application. This work aims to improve the properties of magnesium alloys by cold rolling under inert atmosphere. To achieve this goal, it was developed a laminator equipped with speed control of cylinders that has capacity of 1.1 kilowatts, which works inside a glovebox. The equipment allows producing, by severe plastic deformation, voluminous magnesium-bases samples to storage hydrogen gas, under controlled atmosphere in order to avoid the incorporation of gaseous and/or solid impurities usually found on other viii routes of processing. Structural characterization of the processed samples was performed by techniques of analysis of XRD, SEM and TEM. The hydrogen storage properties were evaluated by DSC and measurements of PCT.