Browsing by Issue Date, starting with "2004-12-06"

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Proposição de um modelo de referência para gestão da qualidade na cadeia de produção de leite e de derivados.
(Universidade Federal de São Carlos, 2004-12-06)
Scalco, Andréa Rossi
;
Toledo, José Carlos de
;
https://lattes.cnpq.br/9421627326330417
The competitivity and the survival of Brazilian dairy, and consequently the dairy production chain, are conditioned to an improvement of products quality and to competitive production costs. The costumer health can be put in risk due to consumption of products in which the quality characteristics are altered, leading the costumer to not purchase the product again, injuring the company image and its survival. The costs, wastes and flaws are above the acceptable standards.According to the diagnosis made by SCALCO (1999), it was observed that there are significant flaws in the quality management system in the major part of dairy industries studied, compromising the final product quality and generating losses in the production process. Some examples of these flaws are: no preventive technical support for the milk suppliers, strong dependence from the inspection and control of the raw material and the final product, use of labor force not well qualified and distribution control process without quality control. The found flaws are not limited just to the industrial segment; they can be felt all over the production of the milk chain and similar product. Due to the fact of the perishable characteristic of these products, the condition of hygiene and refrigeration should be kept trough the chain. By this, it is justified the elaboration of a model to manage the quality trough this chain; considering its specifications in the search for an effective instrument in the quality coordination. The model essentially consists in a system to coordinate information; identification of the problems and elaboration of improvement plans managed by a coordinating agent. The elaboration of the model is established on bibliographical revision about system and techniques of quality management; agro food chain coordination; field research for the acquaintance of the problems and practices of management and coordination of the quality all over the segment of the milk chain and similar; secondary data about the sector and its quality management. The work presents an illustration of the model, as well as an evaluation of it by the sector specialists. This evaluation has shown that this model can be considered original, clear, adequate to the dairy production chain reality, adaptable to its particularities, it contains necessary elements to coordinate the quality and contribute for the improvement and preservation of the product quality, also reducing costs and losses in its part of the production chain.
A construção da qualificação: um estudo de caso na industria da linha branca.
(Universidade Federal de São Carlos, 2004-12-06)
Martínez, Mariângela
;
Rachid, Alessandra
;
https://lattes.cnpq.br/6981682198988902
THE QUALIFICATION CONSTRUCTION: A CASE STUDY IN THE INDUSTRY OF WHITE GOODS seeks to evaluate how the productive restructuring alters the worker's profile in the white goods industry and the perception workers have about it. The restructuring process for which the white goods industry is passing in the last twenty years makes it an object of interest for investigation. With the crisis of theirs original markets, great companies of foreign capital felt the need to reach new markets, mainly in the emerging countries as Latin America, the European East and the Asian Southeast. In Brazil, objective of the expansion of the multinationals, the process of patrimonial rearrange it was characterized by the incorporation of national companies by great foreign groups. The entrance of those multinationals in the Brazilian market intensified the process of productive restructuring refering to production organization, work organizations, changes in job conditions and in qualification demands. Managers and workers of a factory producing cookers were interviewed with the objective of apprehending theirs perception about the changes that took place after a multinational acquired the company. It is analyzed its restructuring process and its main implications for the worker's profile, emphasizing the role of RSI (repetitive strain injury).
Ecofisiologia de plantas lenhosas jovens de cerrado sob irradiâncias contrastantes
(Universidade Federal de São Carlos, 2004-12-07)
Ronquim, Carlos Cesar
;
Prado, Carlos Henrique Britto de Assis
;
https://lattes.cnpq.br/7561749470600567
We evaluated long term responses, such as survivorship, growth, photosynthetic capacity and leaf nutrient content on potted young plants of Cybistax antisyphilitica (Mart) Mart. (Bignoniaceae), Tabebuia chrysotricha (Mart. ex DC) Mart. (Bignoniaceae), Anadenanthera falcata Benth. Speg. (Mimosoideae), Stryphnodendron adstringens Mart. Coville (Mimosoideae), and Copaifera langsdorffii Desf. (Caesalpinioideae) growing in open and in shaded area without water stress. The survivorship, biomass accumulation, height and total leaf area were linked with higher photosynthetic capacity on area basis in open area. Shaded young plants showed higher leaf nutrient content on mass basis (g kg-1), lower respiration in dark, and modified the biomass partition presenting greater mean values of leaf area rate, and smaller values of the specific leaf mass. High transitory concentrations of CO2 increased the photosynthetic capacity in both irradiance conditions. However, the largest apparent carboxylation efficiency values were reached in open area. S. adstringens was unable to stay for long period in shade. The leaf gas exchange, leaf water potential and chlorophyll fluorescence were measured during daily courses in Vochysia tucanorum (C.K. Spreng.) Mart. (Vochysiaceae) and C. langsdorffii during dry and wet seasons to point out shortterm responses of carbon and water balances. The shade condition provoked higher mortality of V. tucanorum during dry season and imposed environmental constraints for V. tucanorum and C. langsdorffii due to the lower values of leaf water potential (Ψ), net photosynthesis (A) and potential photochemical efficiency (Fv/Fm). The higher C. langsdorffii survivorship in shade seems to be related with fast and high biomass accumulation in root during early growth. The sunflecks that took place under canopies are more effective in the rainy season than dry season for carbon assimilation in C. langsdorffii, and seems to cause photoinhibition in dry period by reason of excessive irradiance intensity and lower Ψ values. A careful characterization of growth and photosynthetic performances of young plants of Cerrado species in contrasting irradiances has provided important understanding of ecological conditions behind natural regeneration in Cerrado domain. It enhances the reliability of forest management methods.
Expressão heteróloga e localização subcelular de seis proteínas possivelmente envolvidas com a Síndrome de Down
(Universidade Federal de São Carlos, 2004-12-07)
Justino, Daniela Morilha Néo
;
Silva, Flávio Henrique da
;
https://lattes.cnpq.br/1757309852446263
Down syndrome (DS) is the most common congenital disease occurring in approximately 1 out of 700 live births. In addition to the full HC21 trisomy, rare individuals with clinically recognized DS have only a partial trisomy, carrying a region common to all patients dubbed as Down Syndrome Critical Region (DSCR). Several genes contained in this portion of the HC21 are probably related to the DS phenotypes. In an attempt to characterize some of the DSCR genes, heterologous expression and subcellular localization analyses were performed for the genes DCRB (DSCR4), c21orf45, c21orf59, c21orf83-2, c21orf 95 and c21orf101. Analyses of the recombinant proteins produced in Escherichia coli showed that most of them remained in the insoluble fraction. DCRB was expressed as a soluble protein in E. coli Rosetta (DE3), purified and subjected to assays for secondary structure analyses. Also, deletion and site directed mutagenesis as well as the production of polyclonal antisera against DCRB were performed. Subcellular localization analyses revealed that the proteins DCRB, c21orf45, c21orf59 and c21orf83-2 were distributed in the cytoplasm of mammalian cells and that c21orf95 and c21orf101 resided in the nucleus. Considering the lack of information concerning these proteins encoded in the DSCR our results allowed a insight into some of the proteins provably involved in Down syndrome.
Organização e politização do movimento de saúde dos portadores falcêmicos na grande São Paulo - Brasil
(Universidade Federal de São Carlos, 2004-12-08)
Araújo, Reginaldo Silva de
;
Cardoso, Marina Denise
The principal aim of this research is to look for the normative and political construction of illnesses considered ethnic specific, such as the sickle cell anemia, in the scope of the movements and forms of organization which are representative of certain population groups (in the case, the black movement), as well as in the scope of the politics of public health programs for the attendance of the population that presents the trace of the referring hemoglobin or the proper sickle cell anemia illness. It intends also to study the associations of the Black Movement and the Movement of Specific Illnesses (sickle cell anemia) as they are politically organized and constructing claims together with the governmental services for the attendance of particular demands of health for specific population groups, as it is the case of the preventive care and attention to the health of the carrying patients of the sickle cell anemia. It searches, thus, to know how these movements are interrelated and how they prioritize the guidelines to the improvement of care for the carriers of the sickle cell anemia. The analysis of these forms of organization and political performance would still look for to observe how the construction of the sickle cell anemia as "ethnic illness" or "specific illness" can be an instrument not only for the claims of some population groups towards a specific health care service, but also in which way the proper notion of "ethnic illness" or "specific illness" can become, eventually, a normative construction related to certain political mottos, such as "citizenship" or "racial democracy".
Especificação e implementação de um protocolo tolerante a falhas e de baixa latência para redes de sensores sem fio
(Universidade Federal de São Carlos, 2004-12-10)
Pazzi, Richard Werner Nelem
;
Araujo, Regina Borges de
;
https://lattes.cnpq.br/8964123297688432
Wireless sensor networks are increasingly being deployed for fine-grain monitoring of physical environments subjected to critical conditions such as fire, leaking of toxic gases and explosions. A great challenge to these networks is to provide a fast, reliable and fault tolerant channel for event propagation. The protocol has to meet the requirements of querybased, event-driven and periodic sensor network application scenarios, even in the presence of emergency conditions that can lead to node failures and path disruption to the sink that receives those events. This paper presents a fault tolerant and low latency routing protocol that meets the sensor networks requirements for critical condition monitoring applications. The algorithm uses the publish/subscribe mechanism and the concept of event driven delivery, a technique that selects the shortest path for the notification of events, reducing latency. Fault tolerance is achieved through the triggering of a local path repair mechanism to find new paths with minimal number of transmissions. The protocol was implemented and simulated in the ns-2 network simulator and compared to the Directed Diffusion paradigm. Relevant metrics, such as end-to-end delay, energy dissipation, and delivery ratio, were evaluated showing that the proposed algorithm can be an adequate solution to meet the strict requirements of information propagation in real-time monitoring applications. An extension of the proposed protocol is also presented. This extension is in phase of implementation and simulation and it is expected to reduce data traffic and, consequently, reduce the energy dissipation. This new solution follows a hierarchical approach to propagate data through the network.
Resolubilidade global para uma classe de campos vetoriais no Toro
(Universidade Federal de São Carlos, 2004-12-10)
Silva, Paulo Leandro Dattori da
;
Bergamasco, Adalberto Panobianco
;
https://lattes.cnpq.br/7985048857393389
Problemas correntes sobre nucleação, crescimento de cristais e difusão em vidros
(Universidade Federal de São Carlos, 2004-12-10)
Nascimento, Marcio Luis Ferreira
;
Zanotto, Edgar Dutra
;
https://lattes.cnpq.br/1055167132036400
Alterações funcionais e morfológicas do músculo quadríceps induzidas pelo treinamento excêntrico após reconstrução do LCA
(Universidade Federal de São Carlos, 2004-12-10)
Brasileiro, Jamilsom Simões
;
Salvini, Tânia de Fátima
The anterior cruciate ligament (ACL) is the most commonly injured ligament in the knee and its rupture results in pain, instability, muscle atrophy and weakness. The quadriceps femoris muscle dysfunction is common before and after ACL reconstruction and can persist over years. A detailed understanding of neuromuscular function after ACL reconstruction is critical to the development of optimal rehabilitation strategies. The purpose of this study was to investigate the contributions of functional and morphological factors, in the muscle recovery, after ACL reconstruction. The effects of two therapeutic methods, usually utilized to recover muscle strength were also evaluated: Neuromuscular Electrical Stimulation (NMES) and eccentric exercise. Eight subjects (age = 31.3 ± 5.8 years) who had undergone ACL ligament reconstruction (mean 9.4 ± 0.7 months after the surgery) were randomly assigned to either an eccentric exercise associated with NMES (russian current) or only an eccentric exercise group. Only the involved limb was trained 2 days a week, for 12 weeks. The uninvolved one was also evaluated as reference. The quadriceps muscle function was evaluated by the measurement of the knee extensor torque during isometric and eccentric isokinetic contractions (30 and 120º/s) and by surface electromyography (EMG) of the Vastus Medialis Obliquos (VMO), Vastus Lateralis (VL) and Rectus Femoris (RF) muscles. The quadriceps cross-sectional area (CSA) was measured in six regions using Nuclear Magnetic Resonance Imaging (MRI-I). The initial evaluation showed significant extensor torque deficit both in isometric and eccentric conditions of the involved limb, compared to the contralateral one. There was significant muscle atrophy along the quadriceps extension, mainly in the distal thigh region. The EMG activity was lower for the VMO in all tested situations. NMES did not interfere in the gain of muscular strength, in any of the evaluated functions. The eccentric training increased significantly the isometric (from 198 ± 37 to 228 ± 48 Nm, p<0.05) and eccentric torque at 30 and 120º/s (from 227 ± 56 to 291 ± 65, p< 0.01 and from 199 ± 51 to 240 ± 63, p< 0.05, respectively). Quadriceps cross-sectional area also increased at all the evaluated regions for the involved limb, and the highest hypertrophy was at the thigh proximal region (from 169 ± 27 to 189 ± 25,8 cm2, p< 0.01 ), when compared to the distal region (form 31,5 ± 5,9 to 35,1 ± 6,1 cm2, p< 0.01). The EMG activity of VMO was recovered after the first six weeks of eccentric training. In the same period, the increased extensor torque showed correlation with the increased quadriceps cross-sectional area (r=0,81) and with the recovery of motor unit activation (r=0.69). After twelve weeks of training, there was correlation only between increased torque and cross-sectional area (r=0.78). In conclusion: 1) eccentric training showed to be a potent resource in the recovery of both morphological and functional factors of quadriceps, after ACL reconstruction; 2) NEMS did not interfere in the rehabilitation of these individuals.
Estudo sistematico das propriedades termodinâmicas e criticalidade de filmes finos e super-redes magnéticas
(Universidade Federal de São Carlos, 2004-12-10)
Cabral Neto, João dos Santos
;
Souza, José Ricardo de
In this work we will study through the differential operator technique the surface effect in anisotropic spin ½ quantum Heisenberg model, through theory of effective field (EFT), of a two-spins cluster, in case of simple cubic lattice. Those systems are characterized by the existence of the surfaces, thin films and superlattice, or the bulk. Therefore, the exchange interaction, among the nearest-neighboring, depends on the position of the atoms in the lattice: with the existence of surfaces we have for atoms in those plans, exchange interactions Js and in the adjacent plans interaction J. We studied the thermodynamic properties of the quantum metamagnet for the simple cubic lattice. The limit of stability of the phase antiferromagnetic is presented for the ground state (T = 0) and the respective diagrams of phases are analyzed. With the choice of the interlayer coupling interaction different from the existent in the plane (interplane), parameter λ (interaction λJ), we analyzed the influence of the crossover in the dimensionality [2d(λ =10-5) → 3d(λ =1.0)] of the system in the thermodynamic properties with the appearance of an anomaly in magnetic susceptibility. The surface effect in the thermodynamic properties is treated taking the system on thickness film l, with exchange interactions F and AF, where in that last one we applied an external field. We observed the behavior of the thin film in function of the temperature, number of layers, magnetic field and the ratio Js/J. Changing the exchange interaction between the elements and the layers of the thin film, we characterized the system as a magnetic superlattice. We chose four arrangements in the construction of the superlattice: different inter and interlayer ferromagnetic (F) interaction, the same for antiferromagnetic (AF), alternating the layers among F, and alternating superlattice composed of F (with l1 layers) and AF (with l2 layers), where l = l1 + l2 is the thickness of the film, where we observed the influence of the change of the exchange interaction in the thermodynamic properties and in the critical properties. Several phenomena were observed, as for instance, oscillation in the magnetizations and susceptibility for layers in certain values of the temperature and coupling parameters.
O estudo da guerra e a formação da liderança militar brasileira (1996-2004).
(Universidade Federal de São Carlos, 2004-12-10)
Oliveira, Tânia Regina Pires de Godoy Torres de
;
Ferreira Junior, Amarilio
;
https://lattes.cnpq.br/0748545841167046
This study in the educational field displays the results of the bibliographic, documental and field researches. These were studies about the war through the teaching of Military History as this discipline is taught in the Brazilian Armed Forces schools. It highlights the study of war in History classes, the formation of the war leader in Brazil prepares the soldier for his war performance but this educational orientation has proven insufficient because it does not consider characteristics that are specific to the Brazilian military personnel. That s an educational process that focuses the History of War in a positive way and that does not necessarily prepare the officer for his career in the Brazilian society, a society that is not interested in the topic of Defense. That lack of interest can be explained by the fact that Brazil has rarely run any risks of attack against its territory or its sovereignhood. That s why the people find civical or subsidiary military action to be more important than actions of war. The Army schools programs do not approach polemic topics in the Armed Forces trajectroy in the Brazilian society. That s because our forces have never been on a battlefield. They have mostly done territorial defense and administration. Moreover, it has been involved in both social and political issues. Therefore, its educational formation aims for a performance that will not actually take place in Brazil. It s insufficient for the officer in his actual professional life. To prove our theory, we analyze the politics concerning national defense. These politics have existed since 1996 and we ll also see what they say about military performance and its scarce presence in the teaching-learning process. The element that brings about such analysis is the Military History content because it shows that the civilians society keeps getting more and more estranged from defense issues. Next, we present aspects of Military History in the three Brazilian army schools from 1996 through 2004. We also present its specific features in the teachinglearning process, the orientation for a study of war as an educational element in the preparation of an officer and the way this discipline is regarded by education authorities. We also show the way students of the three Brazilian military schools see Military History, a regular part of their formation, and the way they see their own preparation for the military career. Finally, we reflect upon the political and institutional role of the Brazilian Armed Forces, as it is in the National Defense Policy. We also reflect upon the difficulties to build a program that encloses the multiple functions to be performed by a Brazilian military officer nowadays.
Estratégia tecnológica e desempenho inovador: análise das pequenas e médias empresas produtoras de equipamentos médico-hospitalares de São Carlos e Ribeirão Preto.
(Universidade Federal de São Carlos, 2004-12-10)
Rieg, Denise Luciana
;
Alves Filho, Alceu Gomes
;
https://lattes.cnpq.br/7885557554922569
The goal of this thesis is to identify innovation performances and technology strategies (TSs) adopted by medical equipment firms (those that are technology-based firms (TBFs) or not), located in São Carlos and Ribeirão Preto. Two hypotheses were delineated: (1) the medical equipment firms located in São Carlos and Ribeirão Preto that reached higher innovation performances in the last three years, differ from the ones that reached lower innovation performances in the dimensions of their technology strategies; and (2) the medical equipment technology-based firms located in São Carlos and Ribeirão Preto differ from the ones which are not considered as technology-based firms in the dimensions of their technology strategies. In order to analyze those hypotheses, data about TBF status, TS, and innovation performance were collected from thirty nine medical equipment producers located in São Carlos and Ribeirão Preto. An structured questionnaire was utilized for this purpose. The analysis of this information shows that the technology strategies adopted by the medical equipment firms that reached higher innovation performances are different in many aspects from the ones adopted by those that reached lower innovation performances. There are also differences between the TSs adopted by the medical equipment technology-based firms and the TSs adopted by those which are not considered as technology-based firms. Regarding the firms which reached higher and lower innovation, some indications were obtained that larger investments in internal activities of research and development and in external sources of technology, larger dedication to technology forecasting, and development of a wide portfolio of product and process technologies have allowed the firms to reach larger innovation performances. Regarding TBFs and Not-TBFs, it was observed that the TBFs have worked for the enlargement of their innovation and acquisition capacities of product technologies. Examples of their efforts: (1) large investments in internal R&D activities destined to innovations in product; (2) the number of engineers and scientists allocated to these activities; (3) the amount of key product technologies that those firms have; and (4) their large dedication to technology forecasting, etc. On the other hand, there were indications that N-TBFs (when they carry out some technological effort) dedicate themselves to the enlargement of their operation and adaptation capacities to operate their facilities more efficiently.
Dispersão dielétrica em materiais ferroelétricos
(Universidade Federal de São Carlos, 2004-12-13)
Guerra, José de Los Santos
;
Eiras, José Antônio
;
https://lattes.cnpq.br/6653223814715498
In the last decades, the high frequency dielectric response has been one of the most studied issues in the ferroelectricity area. The main dielectric characteristic is the strong dependence of the dielectric parameters (real and imaginary component of the dielectric permittivity) with the measuring frequency (dielectric dispersion). Among them, the perovskite-structured family, such as barium titanate (BaTiO3), pure and modified lead zirconate titanate (PZT and PLZT, respectively), and some others similar compounds can be emphasised. In order to explain such phenomenon some theoretical models have been proposed, nevertheless a major discussion about the true mechanism responsible for the microwave dielectric dispersion remains still open. In this work, a pressurecontrolled sample holder for microwave dielectric measurements is presented. The experimental set-up involves a coaxial line coupled to a pressure-controlled sample holder able to obtain the dielectric characterization as a function of the temperature. On the other hand, the microwave dielectric dispersion process was investigated in the relaxor and normal ferroelectric composítions of lanthanum modified lead titanate ceramics. The obtained results were discussed concerning a damped harmonic oscillator, considering the vibration of the boundaries of the polar regions, independently of their structure, as the mechanism responsible for the high frequency dielectric anomalies (dielectric dispersion and resonance) in ferroelectric systems.
Métodos exatos baseados em relaxação lagrangiana e surrogate para o problema de carregamento de paletes do produtor.
(Universidade Federal de São Carlos, 2004-12-13)
Oliveira, Lilian Kátia de
;
Morabito Neto, Reinaldo
The purpose of this work is to develop exact methods, based on Lagrangean and Surrogate relaxation, with good performance to solve the manufacturer s pallet loading problem. This problem consists of orthogonally arranging the maximum number of rectangles of sizes (l,w) and (w,l) into a larger rectangle (L,W) without overlapping. Such methods involve a tree search procedure of branch and bound type and they use, in each node of the branch and bound tree, bounds derived from Lagrangean and/or Surrogate relaxations of a 0-1 linear programming formulation. Subgradient optimization algorithms are used to optimize such bounds. Problem reduction tests and Lagrangean and Surrogate heuristics are also applied in the subgradient optimization to obtain good feasible solution. Computational experiments were performed with instances from the literature and also real instances obtained from a carrier. The results show that the methods are able to solve these instances, on average, more quickly than other exact methods, including the software GAMS/CPLEX.
Preparação, caracterização e estudos termoanalíticos de bases de Schiff biopoliméricas e seus complexos de cobre
(Universidade Federal de São Carlos, 2004-12-13)
Santos, José Estrela dos
;
Cavalheiro, Éder Tadeu Gomes
;
https://lattes.cnpq.br/4745280891704797
The present work is divided in three parts. The first part deals with the purification and characterization of commercial chitosan from different suppliers. The second part describes the synthesis and characterization of biopolymeric Schiff bases obtained of chitosan. The Schiff bases were obtained from the condensation chitosan ( DA= 90%) with salicylaldehyde and its 5-bromo, 5-chloro, 5-nitro, 5-methyl, 5-methoxy sallicylaldehyde derivatives in acidic medium. Using the data obtained in the spectra of 1H NMR of the Schiff bases, it was determined the Mean Degree of Substitution ( DS ). The Mean Degree of Substitution ( DS ) ranged from 4.6% to 68.5% depending on the R group. The most substituted Schiff bases (highly DS ) has been used to obtain copper complexes. All the products were characterized by elemental analysis, hydrogen nuclear magnetic resonance (1H NMR) and infrared spectroscopy (IR). SEM photomicrographs was obtained with the purpose of verifying in morphologic changes in the biopolymerics Schiff bases as well as the copper complexes obtained from these bases in relation to starting chitosan. In a third stage, it was investigated the thermal behavior of biopolymerics Schiff bases and with the starting chitosan. An evaluation of the hydration and of thermal decomposition of chitosan and of the biopolymerics Schiff bases was accomplished using Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC). The chitosan TG curves under N2 presented two mass losses representing dehydration and decomposition of the polymer. Under air an additional step was observed due to the burnning of carbonaceous material. The biopolymeric Schiff bases decomposed in three steps: dehydration, decomposition and burnning of the carbonaceous residue in air. In both cases the DSC curves agreeded with the thermal events described by the TG curves.
Contribuição ao estudo dos mecanismos envolvidos na aglomeração esférica de sólidos em suspensão
(Universidade Federal de São Carlos, 2004-12-13)
Aldeia, Wagner
;
Giulietti, Marco
;
https://lattes.cnpq.br/7703659740618915
This work was developed with the objective of to improve the state of the technique of spherical agglomeration of solids in suspension and to promote a progress in the necessary knowledge for its exploration in larger scale. We studied the agglomeration of salicylic acid crystals obtained from the reaction of sodium salicylate and sulfuric acid. The agglomeration was promoted using chloroform as bridging liquid, that was introduced in the solution immediately after the precipitation of crystals, the agglomeration being monitored by measurement of the suspension turbidity. The effect of variables as temperature, flow rate of chloroform feed, agitation and solid concentration on the following product properties were investigated: granulometric distribution, flowability, real and apparent densities, mechanical resistance, residual solvent, porosity and morphology. The results of this study allowed the identification of a new mechanism of agglomeration of solids from suspension and the possibility of controlling the process, in order to provide particles of a great variety of sizes, depending on the average size of the original crystals and according to the requirements of the final product application.
Seletividade da Clinoptilolita natural por metais tóxicos em sistemas aquosos
(Universidade Federal de São Carlos, 2004-12-13)
Fernández, Juan Carlos Torres
;
Gubulin, José Carlos
Natural zeolites are the most important inorganic cationic exchangers exhibiting high ion exchange capacity, selectivity and environment compatibility. Heavy metals are well known for toxicity and their disposal is a significant industrial waste problem. The goal of this work was directed to evaluate the selectivity of a purified homo-ionic clinoptilolite mineral for aqueous Pb2+, Zn2+, Cu2+ and Na+ ions at 0,005 eq/L and 303 K, interpreted through the application of empirical thermodynamic models to the zeolite phase (Margules, Van Laar, Wilson) coupled with a well established ion-interaction approach for the electrolyte solution (Pitzer). The present study considered the following stages: (1) adsorbent material: preparation and characterization; (2) aqueous solutions: nitrates of sodium, lead, zinc and copper; (3) equilibration of weighed amounts of homo-ionic clinoptilolite with a series of solutions containing the two competing cations; (4) analysis for aqueous cations by AAE; (5) construction of the equilibrium points; isotherm analysis; (6) test for thermodynamic reversibility; (7) empirical models for the zeolite phase (admitted as a solid solution) jointed to the ion-interaction model chosen for the aqueous solution; (8) equilibrium constant and Gibbs free energy for the ion-exchange reactions; phenomenological interpretation of the thermodynamic parameters obtained by means of the application of empirical models to the zeolite phase. The above procedure was, in the same way, followed for the ternary systems. The results obtained in this work shown that the empirical models adopted for the solid phase coupled to Pitzer s model for the activity coefficients in the electrolyte solution describe successfully the binary ion-exchange equilibria. The calculated equilibrium constant and the corresponding Gibbs free energy for each binary-exchange reaction resulted in a selectivity sequence, at the normality and temperature of this study, easily deduced as: 2 2 2 Pb Na Cu Zn + + + + > > . Besides, the parameters estimated applying the Margules , Van Laar s and Wilson s equations for cations in the solid binary mixture resulted in useful values quantifying adequately the cation zeolite framework interactions, thus, an alternative way to interpret the adsorbent selectivity from the charge and cationic radius effect. The ternary parameters obtained applying multi-component empirical models do not explain properly the non-ideality of ions in a solid mixture containing more than two components. This is in accordance with the results encountered in a number of publications on crystal structure of heulandite-group zeolites: these aluminosilicates are found to contain crystallographically distinct set of sites throughout the exchanger framework and that normally each set of sites is partially populated by the exchanging ions. As a consequence, activity coefficients for a multi-component exchange reaction cannot be predicted from appropriate binary data for a heterogeneous exchanger, since the phenomenological binary coefficients are complicated functions of each site set, population and composition, and both these properties will change on introducing other species of ion in the exchanger. In this sense, and from what were obtained here, is believed that multi-component solid phase nonideality must, at least, be interpreted through the application of statistical thermodynamic models considering the energetic heterogeneity of a number of site set and the charge density of the specific zeolite framework.
Mini-fábrica: uma nova proposta de arranjo produtivo e organizacional híbrido em uma empresa do setor eletroeletrônico.
(Universidade Federal de São Carlos, 2004-12-13)
Rotta, Ivana Salvagni
;
Grün, Roberto
;
https://lattes.cnpq.br/6028266827740491
;
https://lattes.cnpq.br/1366592110711803
This thesis is concerned to the structure of a productive and organizational arrangement the mini-factory (MF) and its related concepts. A local subsidiary of an electronics multinational corporation was analysed, considering the main characteristics of the mini-factory. The thesis analysed the initial project for the mini-factory, its planning and implementation, the main changes and adaptations along the years, and the way that the mini-factory concept is used more recently by the company. The thesis also analysed the mini-factory impacts and contributions for the work groups and the qualification processes, focusing both people and organization. A case study research was developed, including interviews and data research, considering three distinctive periods of study. The variety of data collected supported the analysis of several important characteristics of the company and the way it works. The main results of this thesis show that the arrangement studied, called mini-factory by the company, is, actually, a new hybrid productive and organizational arrangement, that integrates characteristics of the mini-factory original concept with the related concepts. The results indicate that the adaptation processes, made during the years by the company, developed an arrangement different from those described by the other companies and even by the literature. These identified characteristics had been crucial for the good results achieved by the company and, nowadays, it is considered an example for the other subsidiaries of this multinational corporation.
Avaliação da qualidade da água do rio Manguaba, estado de Alagoas, Brasil, com ênfase na comunidade de macroinvertebrados bentônicos
(Universidade Federal de São Carlos, 2004-12-13)
Freitas, Liriane Monte
;
Gessner, Alaíde Aparecida Fonseca
;
https://lattes.cnpq.br/8465752836529703
The Manguaba river basin is located in the State of Alagoas, Brazil. It has an estimated area of 352 km2 and it drains part of the counties of Novo Lino, Jundiá, Porto Calvo, Japaratinga and Porto de Pedras. Since the riverhead, visible anthropic interferences can be detected. The river crosses rural zones (where sugar-cane crops predominate), as well as urban areas. With the aim of evaluate the environmental conditions of this river, and considering the regional context, this thesis is the first study in the State of Alagoas on benthic macroinvertebrates carried out in fluvial environment. The different anthropic activities developed along the river was the criterium to establish seven stations for collection purposes, that were plotted between 08º59 S - 35º42 W e 09º04 S - 35º22 W. The samples were collected on rainy and dry season, during 2001 and 2002. Samples of superficial water and bottom sediments were used for abiotic analyses. Fauna samples were done to study qualitative and quantitative features. Four higher groups were detected, with 76 taxonomic categories. Chironomidae (Insecta: Diptera), with 28 genera, was the most important among the 44 families identified. Larvae of Chironomidae, Oligochaeta (Tubificidae, Naididae), Hirudinea (Glossiphoniidae) and Mollusca (mainly Thiaridae) overtopped in high density and occurrence. Among Chironomidae Procladius and Chironomus were dominant in the area of the riverhead and Polypedilum (Tripodura) was an important group all along the river. Diversity and evenness indices indicated low to medium values. The similarity analysis and multivariate correspondence analysis distinguished the riverhead from the other sampling stations. Among the last ones, the results indicated higher impacts at on the stations near urban areas. This could be confirmed by the faunistic composition of taxonomic groups known as tolerant.
O uso do system dynamics em um modelo de apoio a comercialização: uma aplicação à agricultura familiar
(Universidade Federal de São Carlos, 2004-12-13)
Faulin, Evandro Jacóia
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Azevedo, Paulo Furquim de
The family farmers play an important role in the Brazilian agricultural production. However, even though they occupy a prominent position in the agricultural production in Brazil, there are not management techniques specifically suitable to family farmers. Focusing on commercialization and vertical coordination, this dissertation has as main objective the development of management prescriptions related to procurement and marketing activities undertaken by family farmers. Computational simulation, based on System Dynamics methodology, was the main instrument to support procurement and marketing decisions. Interviews with thirty three vegetables family farmers and five of their main suppliers, all located in the region of São Carlos SP, provided the real data for the design of the computational model. The empirical research revealed that family farmers do not plan procurement and marketing appropriately, although they manage to compete with non-family production. The use of governance structures based on trust seems to be the main cause of their survival and success. The simulation based on System Dynamics helped the design of models that represent and help the decision making related the procurement and marketing by family farmers.