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The coopetitive effect in supply chains: exploring the relationship between multiple supply chains from the focal agent perspective
(Universidade Federal de São Carlos, 2024-04-10) Brandão, Maicom Sergio; Godinho Filho, Moacir; https://lattes.cnpq.br/6136685270563354; https://lattes.cnpq.br/6709066592331133; https://orcid.org/0000-0002-7798-1922
This thesis explores the possibility of a form of interaction between supply chains known as coopetition, which combines cooperation and competition. The main objective is to investigate coopetition among multiple supply chains within an organization from the perspective of supply chain relativism and its implications. This study, organized into six articles, unfolds into two primary streams of inquiry: the perspective of multiple supply chains - resulting in the theoretical framework of the research - and coopetition - providing the basic concepts used in the study. Through a first systematic review, the thesis underscores the significance of the idea of flow as a fundamental concept in understanding the relativism of supply chains, with a particular emphasis on the interaction among material, financial, and information flows. Furthermore, it formalizes the perspective of multiple supply chains as an alternative to the conventional characterization of nodes and links, highlighting the multifaceted nature of supply chain phenomena. Within this vein, it presents the perspective of multiple supply chains as part of organizational discourse from sustainability reports. Besides, the thesis establishes a theoretical framework to investigate coopetition among multiple supply chains. Through a second systematic literature review, it is found that, within the inter-organizational context, there exist various forms of coopetition (technology-based, relationship-based, and channel-based) associated with different supply chains. Through a multiple case study, the execution and cooperative interaction among multiple supply chains are observed, and their similarities and differences concerning inter-organizational coopetition are listed. Finally, through a retrospective case study, it observes how changes in organizational structure can foster the emergence of the distinct supply chains of the organization and shift coopetitive dynamics along the coopetition continuum. The coopetitive effect addressed in this thesis corresponds to interaction founded on a cooperative context occurring among multiple supply chains within an organization - delimited, socialized, and managed by a group of actors - where internal resource scarcity may lead to competition among them. The implications of this interaction can affect not only the focal company but also other links in the supply chain positively or negatively. As contributions, this study proposes that variants of the supply chain term be observed as representatives of the evolution of the research field from the main concepts of phenomenon, orientation, and supply chain management. Considering coopetition, expands the scope of analysis levels to include coopetition among multiple supply chains. Furthermore, the thesis contributes to managerial understanding by proposing strategies to effectively navigate coopetitive dynamics. It emphasizes the importance of identifying core and non-core supply chains, managing power asymmetries among them, and recognizing the role of organizational structure in shaping coopetitive interactions. Additionally, it highlights the importance of mediating elements capable of capturing the global and individual value creation of multiple supply chains. It also underscores the need to differentiate coopetition from a mere supply constraint due to its relational characteristic, thus avoiding tensions and conflicts solely relying on trust among actors to be solved.
Caracterização do óxido formado na superfície da junta M5TM/Zircaloy- 4 soldada por resistência e pressão após testes de corrosão em autoclave a 360°C
(Universidade Federal de São Carlos, 2024-04-10) Soares, Alexandre Roberto; Rovere, Carlos Alberto Della; https://lattes.cnpq.br/8141224513975606; https://orcid.org/0000-0003-1534-0561; Silva, Rodrigo da; https://lattes.cnpq.br/3763016865133213; https://orcid.org/0000-0002-1381-1334; https://lattes.cnpq.br/5080379377721278; https://orcid.org/0000-0001-6311-2884
The nuclear fuel cycle involves uranium mining and chemistry, fuel manufacturing, fuel element operation in reactors, and post-irradiation treatment. The casing tubes are produced with zirconium alloys, as they have a low neutron capture cross-section. Welding processes in nuclear applications are electron beam, laser, resistance, projection and spot welding. The welds undergo destructive and non-destructive tests to characterize the joint, tube bursting tests, metallography, and corrosion. The present work sought to characterize the oxide layer formed on the surface of a joint composed of zirconium M5TM and Zircaloy-4 alloys welded by the Resistance Pressure Welding (RPW) process. Autoclave corrosion tests were carried out to simulate operational conditions, identifying specific oxidation/corrosion mechanisms after analysis. The results obtained show that during the corrosion process, both the surface of the plug and the tube oxidize, forming an oxide layer composed predominantly of the m-ZrO2 phase, adhering and continuing on the surface of both materials. Furthermore, small Zr(Fe,Cr)2 precipitates present in the buffer microstructure oxidize, remaining on the surface of the oxide layer. For the welded bead, the rapid growth of the oxide leads to the formation of a continuous nodule of white oxide, which presents a high fraction of the t-ZrO2 phase. The growth of this white oxide nodule is accompanied by the penetration of the oxide into the bead reinforcement at the plug/weld bead interface region. As the corrosion process progresses, complete oxidation of the Zr(Fe,Cr)2 precipitates occurs, leading to the formation of voluminous oxide nodules composed of a mixture of phases: t-ZrO2, m-ZrO2, Cr2O3 and Fe2O3. Although the oxides observed were obtained under more severe conditions than usual, they proved to be safe in terms of depth and thickness, not drastically affecting the weld bead region even after five corrosion cycles.
Modelagem numérica do perfil térmico e do escoamento de material termoplástico por extrusão em um cabeçote customizado para manufatura aditiva
(Universidade Federal de São Carlos, 2024-04-10) Santos, André Luiz Grando; Silveira, Zilda de Castro; https://lattes.cnpq.br/2567496668379673; https://orcid.org/0000-0002-5040-0403; Lucas, Alessandra de Almeida; https://lattes.cnpq.br/9754332336954137; https://orcid.org/0000-0002-4762-6030; https://lattes.cnpq.br/1235655060164028; https://orcid.org/0000-0003-4912-156X
This work presents a procedure for modeling and numerical analysis of the flow of a thermoplastic fluid with pseudoplastic behavior applied to a custom miniature vertical head based on twin-screw extrusion for additive manufacturing. It is a case study conducted using the miniature head of an innovative prototype conceived on a laboratory scale for direct manufacturing using the PP RP141 raw material in powder form. The temperature profiles in the head were estimated, and the techniques adopted were validated with experimental data from a prototype of the extruder head. The pressures and flow details in the channels forming the extrusion nozzle (die) were revealed through a 3D model. The dimensionless parameters characteristic of the types of elements that constitute the screws were also determined by a 3D model. A 1D flow model published by another author was modified and coded to predict the pressures and, consequently, the location of the fully filled sections of the screws. This modified model was validated by comparison with documented cases in the literature. Furthermore, the filled sections were simulated using mesh immersion techniques in a 3D model, and details of the complex flow in these sections were discussed. Finally, a comparison of the pressures predicted by the modified 1D model with those obtained by the 3D model revealed a good approximation between the results of these analyses using the technique proposed in this work, thus establishing a procedural roadmap for exploring the processing limits of the unit, screw compositions, process variables, and materials, as well as aiding decision-making in the design stages of other units and improvements of this innovative variant of additive manufacturing.
Lebesgue solvability of equations associated to elliptic and canceling linear differential operators with measure data
(Universidade Federal de São Carlos, 2024-04-10) Biliatto, Victor Sandrin; Moonens, Laurent; https://orcid.org/0000-0001-6351-2626; Picon, Tiago Henrique; https://lattes.cnpq.br/7853908129934448; https://orcid.org/0000-0001-5911-8212; https://lattes.cnpq.br/6295450179617895; https://orcid.org/0000-0003-4184-953X
In this thesis, we present new results on the solvability of the equation A*(x,D) f = µ for f in L^p, with complex measure data µ, associated to an elliptic linear differential operator A(x,D) of order m with variable complex coefficients. Our method is based on (m,p)-energy control of µ giving sufficient conditions for solutions when 1 ≤ p < ∞. A particular study is presented in the global setting of Lebesgue solvability for the equation A*(D) f = µ, where A(D) is a homogeneous differential operator with constant coefficients. We also obtain sufficient conditions in the limiting case p = ∞ using new L^1 (global and local) estimates on measures for elliptic and canceling operators, which are interesting on their own.