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Estudo dos riscos relativos à estrutura organizacional em implantações de Lean Production: um estudo de caso integrado em unidades de negócio manufatureiras de uma empresa multinacional
(Universidade Federal de São Carlos, 2016-03-28) Farhat, Daniel Madazio Rahal; ; Torres, Isaías; https://lattes.cnpq.br/9268170751052087; Guimarães, Márcia Regina Neves; https://lattes.cnpq.br/9250214706491925; https://lattes.cnpq.br/0514266989871705
Nowadays there are many methods and techniques proposed for the implementation of Lean Production, and there are several risks identified in studies that influence the success of these implementations. However, little is said about the relationship of these risks with changes in organizational structures and how they are treated during the implementations. This work, performed in business units of a large multinational company, aims to identify, according to the implementation responsible, the risks related to the elements of the organizational structure that may be associated with Lean Production implementations, as well as to check whether they were considered during the structuring and execution of the implementation projects. The study was based on an integrated case study in four units located in Brazil, which passed through distinct Lean Production implementation projects. An amount of 101 different risks related to the elements of organizational structures was identified and associated with Lean Production implementations in the four business units, as well as it can be seen that 31 of them are patterns between at least two of the four units. Seeking for standard risks among the four units, just the threat of a culture resistant to change and the opportunity of the training in Lean Production application were found. Such evidence clearly shows that these four business units belonging to the studied company had each other different types of risks related to the organizational structure associated with the implementations. A small portion of these risks, mostly opportunities, was considered during the design of the project, but still not using a systematic or standardized way, and most of the risk is not identified or at design or during project execution, but rather treated as becomes a real difficulty for the achievement of the results of project implementation.
Síntese e caracterização de géis para cromatografia de exclusão por tamanho via reticulação de Acetato de Celulose com 4,4' - Difenilmetano Diisocianato (MDI)
(Universidade Federal de São Carlos, 2016-03-28) Rosa, Wesley de Oliveira; Botaro, Vagner Roberto; https://lattes.cnpq.br/2907189124654066; https://lattes.cnpq.br/8873420219898061
The need to obtain biomaterials in order to reduce environmental impacts has been the focus of research groups in recent years, and cellulose, a dominant component at most forms of plants is a promising resource because of its abundance. In order to improve the ability processing, the chemical modification of cellulose has been widely studied. Among the most important reactions of cellulose are: etherification, esterification, acetylation and oxidation; being cellulose acetate, viscose, nitrocellulose and cellulose ethers, the main cellulose derivatives. The chemical modification with isocyanates presents some unique properties, such as absence of by-products and chemical stability of the urethane group. In this work we were synthesized gels obtained by modified cellulose acetate (CA) with a degree of substitution (DS) 2,5 by crosslinking, with 4,4' - Diphenylmethane diisocyanate (MDI) in stoichiometry of 1:1, in homogeneous by varying the humidity and the homogenization time. For characterization were used the following techniques and tests: vibrational infrared absorption spectroscopy (Fourier Transform Spectrometer - FTIR), size exclusion Chromatography (SEC), molecular absorption spectrophotometry UV-VIS, density determining of the gels by pycnometry, determination of the coefficient swelling, determination of cross-links by Flory-Rehner theory, thermogravimetry (TG) and scanning electron microscopy (SEM). Crosslink density results showed that the gel synthesized in the absence of moisture suffered greater crosslinking with an average number of repeat units between the crosslinking points of about 1000 times lower. The potential applications of these gels were tested, by using than as stationary phase in size exclusion chromatography, having been assessed its efficiency in the fractionation and separation of natural and synthetic polymers. Results showed the effectiveness of the gel as stationary phase on separation of polymers, opening up a range of opportunities, taking into consideration the simplicity of the process and lower costs attributed to it.
Produção de ácido cítrico a partir do cultivo de Aspergillus niger e Trichoderma reesei em bagaço de cana-de-açúcar e fermentação etanólica do extrato fúngico
(Universidade Federal de São Carlos, 2016-03-28) França, Hiléia Camargo Ribeiro; Bastos, Reinaldo Gaspar; https://lattes.cnpq.br/9329363278429665; https://lattes.cnpq.br/5128282862615398
Solid-state cultivation (SSC) are characterized by microbial growth on solid supports, often agroindustrial by-products, in conditions of absence of free water. Citric acid and ethanol are important commercial bioproducts used in various industrial sectors, which could be obtained by SSC of fungi from bagasse sugarcane and vinasse, with subsequent fermentation, minimizing the cost of production with the use two industrial byproducts. Fungi consortium has advantages over the isolated cultures, highlighting the best use of substrates due to enzyme supplementation, especially in terms of hydrolases. In this sense, the aim of this research was to evaluate the SSC of Aspergillus niger and Trichoderma reesei alone for the production of citric acid from sugarcane bagasse impregnated with different solutions (sucrose and vinasse) and the consortium of these fungi followed by ethanol fermentation of fungal yeast extract. The experimental steps set up the cultivation of A. niger for production of citric acid from submerged particles of sugarcane bagasse; SSC of A. niger and T. reesei alone and mixed using as impregnating with and without sucrose solution and vinasse pretreated with acid hydrolysis; ethanol fermentation of fungal extract by Saccharomyces cerevisiae. Results indicate the feasibility of Aspergillus niger´growth on submerged particles of sugarcane bagasse for citric acid production in medium with addition of sucrose. SSC of this fungus from sugarcane bagasse resulted in 103 mg L-1 of citric acid content in 4 days without addition of sucrose to the solid medium. Similarly, SSC of Trichoderma reesei in sugarcane bagasse leads citric acid production around 67 mg L-1 with raw vinasse in the first growth day. Specific production of 2.51 mg g-1 h-1 in terms of citric acid was obtained from the fungal consortium higher than that obtained using the two fungi alone. Ethanol fermentation tests by Saccharomyces cerevisiae from the fungal extract obtained by the SSC indicated that it is feasible to obtain a second bioproduct, especially high yield of glucose into ethanol to extract condition obtained from T. reesei without sucrose in 5 days. Results suggests the viability in the use of two important by-products of the sugarcane industry via microbial consortium by SSC, leading an interesting research field with various scientific and regional aspects.
Influência da adição de Co nas propriedades de catalisadores à base de Ni suportados em MgAl2O4 aplicados na reforma a vapor do ácido acético
(Universidade Federal de São Carlos, 2016-03-28) Mizuno, Stefanie Caroline Mayumi; Santos, João Batista Oliveira dos; https://lattes.cnpq.br/0285313473901330; Bueno, José Maria Corrêa; https://lattes.cnpq.br/0157452280626031; https://lattes.cnpq.br/0805524022565035
The steam reforming of acetic acid (SRAcH), a model compound of pyrolysis-oil, was studied over MgAl2O4-supported Co-Ni catalysts with different Co/Ni ratios, prepared by impregnation using the incipient wetness method. The catalysts were characterized by X-ray powder diffraction, temperature programmed reduction, temperature programmed desorption, and thermogravimetry. In the steam reforming reaction of AcH, both Ni and Co catalysts suffered partial oxidation due to contact with the reaction mixture. The ketonization reaction occurred on the MgAl2O4 support and the presence of Co or Ni changed the reaction pathway of species adsorbed on the support, which suppressed the formation of acetone. The cleavage of C-C bonds was favored on the Ni surface, resulting in CHx species, which in the presence of H2 were preferentially hydrogenated to CH4 at low temperatures. On the other hand, on the Co surface the CHx species were decomposed to C* and H* as the temperature increased. The addition of Co to Ni catalysts inhibited CH4 formation and carbon accumulation.
Particle image velocimetry and computational fluid dynamics applied to study the effect of hydrodynamics forces on animal cells cultivated in Taylor vortex bioreactor
(Universidade Federal de São Carlos, 2016-03-28) Singh, Harminder; Suazo, Cláudio Alberto Torres; https://lattes.cnpq.br/9591447226240450; https://lattes.cnpq.br/5920252813553567
Taylor-Vortex reactor (TVB) is fast becoming the next bioreactor to culture animal cells due to milder shear and homogeneous flow structures through-out the bioreactor in comparison to the traditional stirred vessels. However, there is little information in the literature for the TVB on the viscous energy dissipation rate (VEDR), which is considered the ideal parameter to characterize the cell death, and its geometrical aspects, which may affect the culture of animal cells resulting in poor efficiency. Consequently, this work focuses on: the estimation of the VEDR of mean flow and turbulent kinetic energy (TKE) using an experimental 2D particle image velocimetry (PIV) method and a computational fluid dynamics (CFD) method using different turbulence models, principally the direct numerical simulation (DNS) model; and, the impact of the off-bottom clearance area and the external cylinder’s bottom shape on the flow structures of TVB. Both numerical and experimental methods confirm that the bulk zone comprising of the 80 % of the gap-width, where the cell cultures will spend most of the time, has a near constant velocity magnitude of around 50 % of the tip velocity and VEDR values which are around 10 times lower than at the walls. Qualitatively, the DNS model predicted well the flow structure of both mean and turbulence parameters in comparison with the experimental PIV predictions. However, quantitatively only the mean velocity predictions are in good agreement with the PIV data with certain amount of under-estimation of the turbulence parameters. Among different turbulence models, the large eddy simulation (LES) - wall adapting local eddy-viscosity (WALE) model presented best comparison with the DNS model data for all the flow parameters; while, the Reynolds stress model and the LES-Smagorinsky models were the poorest. On the other hand, the Reynolds averaged Navier-Stokes (RANS) based two equation models estimated well the mean velocity components in comparison with the DNS model data, but could not capture well the flow structures of the turbulence components. The geometrical features of curved surface of outer bottom and off-bottom clearance area which are of practical importance in stirred vessels, impact adversely the flow structures in the TVB due to poor axial velocity component. In comparison with the spinner vessel, a stirred tank type bioeactor but with lower shear, for similar Re/ReT ratio, the maximum and mean VEDR were always found to be of lower magnitude values, and due to much less difference between the maximum and the mean values, the TVB presents more uniform structures in comparison to the spinner vessel.