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Evolução microestrutural e propriedades mecânicas das ligas Al-10%Si-0,45%Mg e Al-10%Si-1,0%Mg
(Universidade Federal de São Carlos, 2021-07-28) Gandolfi, Maressa; Spinelli, José Eduardo; https://lattes.cnpq.br/8882038118634925; https://lattes.cnpq.br/3579243272425225
Al-Si alloys with high silicon (Si) content are widely used in aerospace, automotive, microelectronics, among others. In this context, the Al-10 wt.% Si alloys with the addition of Magnesium (Mg) are alternatives that arouse interest for processing in permanent molds, by lost wax, by high pressure die-casting and by additive manufacturing. Due to growing interest, there are necessary more in-depth studies of the interrelationships between solidification thermal parameters, microstructural parameters and mechanical properties of the Al-10 wt. % Si-Mg alloys, both due to the scarcity of these data in the literature and due to the importance of this knowledge in the pre-programming related to foundry processes. In this sense, a study for the conditions of slow and moderate solidification was carried out through this Master's proposal. Through transient directional solidification experiments a wide range of dendritic scale variation was obtained for both Al-10 wt.% Si-0.45 wt.% Mg and Al-10 wt.% Si-1.0 wt.% Mg alloys, with primary and secondary dendritic spacings, 1 and 2 ranging from 76 m to 360 m and from 17 m to 38 m, respectively. The interdendritic phases detected were Mg2Si with Chinese Script morphology and Si with lamellar morphology, with a higher fraction of Mg2Si for the alloy containing 1.0 wt.% Mg. Thanks to the higher fraction of refined Mg2Si particles, in addition to greater refining and complexity of the dendritic network (smaller 2), the Al-10 wt.% Si-1.0 wt.% Mg alloy achieved greater mechanical strength and ductility compared to the Al-10 wt.% Si-0.45 wt.% Mg alloys. The samples of the Al-10 wt.% Si-1.0 wt.% Mg alloy with 2 of 16 m show the best balance of tensile properties with ultimate tensile strength limit of 220 MPa, yield tensile strength of 142 MPa and elongation-to-fracture of 5%.
Cultura e Interculturalidade em movimento no ensino de Português Língua Estrangeira: um estudo bibliográfico-documental
(Universidade Federal de São Carlos, 2021-07-28) Yonaha, Tábata Quintana; Viana, Nelson; https://lattes.cnpq.br/6252579012192711; https://lattes.cnpq.br/4076862793928173
This dissertation is the result of a qualitative bibliographic research design. The concepts of culture and interculturality in the Foreign Language Teaching (henceforth FLT) are investigated under the scope of Applied Linguistics. Its main aim was to gather theoretical contributions on these concepts, to relate and discuss them from a critical perspective following an interpretative-constructivist approach. The reference sources for the development of this research were primary (books, articles, technical texts) and tertiary (databases). We present primary concepts about culture in the language studies area (KRAMSCH, 2011; 2017). In addition, we develop a historical overview of the relationship between language and culture based on the works of Risager (1998) and Kramsch (2001; 2006; 2007; 2010; 2011). Another concept presented is culture under different perspectives based on the contributions of Holliday (2012) and Abdallah-Pretceille (2006). This work discusses the most widely used intercultural models in academic research on this theme (BYRAM, 1998; BENNETT, 1998; DEARDORFF, 2009) through analyzing their main characteristics. The in-depth analysis of these models has the emergency of an epistemic turn of popular knowledge and scientific knowledge supported and advocated in Walsh's decolonial proposals (2008; 2010). Issues as power, exclusion, subordination of identities, knowledge, languages and systems are scrutinized in Walsh’s work, as well as in the works of Dervin (2006; 2017). The author problematizes solid conceptions of culture and interculturality while taking the critical interculturality proposals of Tubino (2005) and Candau (2016) into consideration. Seeking, with this discussion, to contribute to the visibility and expansion of this theme in the teaching of Portuguese as a Foreign Language (PFL), we focused on the Celpe-Bras exam due to its washback effects into this field, analyzing guiding documents for the face-to-face interaction of the evaluation process, namely in relation to the notions of culture and interculturality embodied in aspects of the Provocative Elements and Interaction Scripts. We consider that the results of this research can contribute to discussions and, potentially, to the practices of PFL teachers, in initial and in continuous professional development, in a reflexive way, since the pedagogical alternatives presented emphasize the importance of breaking away from solid constructions of culture ( DERVIN; MACHART, 2015) and to question crystallized senses and debatable certainties of knowledge (MOITA LOPES; FABRÍCIO, 2015) about cultures and interculturality in the context of teaching in this area.
Uso de extrato de canela, extrato de cravo e hipoclorito de sódio no controle de Fusarium oxysporum f. sp. lycopersici e Alternaria alternata
(Universidade Federal de São Carlos, 2021-07-28) Carmello, Camila Rodrigues; Rosa-Magri, Marcia Maria; https://lattes.cnpq.br/4166319985147604; Cardoso, Jean Carlos; https://lattes.cnpq.br/3681181863704059; https://lattes.cnpq.br/9928689337714493
The tomato crop is very sensitive to phytosanitary problems, among the fungal diseases that affect the crop, the Fusarium wilt caused by Fusarium oxysporum f. sp. lycopersici and the black spot, caused by Alternaria alternata. The use of pesticides is one of the main ways to manage pests and diseases in tomato crops, making control measures based on systematic applications of fungicides following a calendar of weekly applications. While the application of fungicides brings benefits to the productivity of horticultural crops, their use has been restricted by environmental risks and the greater demand for food without the presence of residues of these substances. In this context, the use of natural products from plants and already used as food can be an alternative form of control. Thus, this work aims to evaluate the in vitro growth inhibition potential of different pathogenic races of Fusarium oxysporum f. sp. lycopersici (causer of fusarium wilt) and Alternaria alternata (black spot), by the use of aqueous extract of cinnamon and aqueous extract of clove, in addition to the use of sodium hypochlorite solution, as well as its application to reduce symptoms of black pinta on tomato fruits in post-harvest. For this purpose, the work was divided into two chapters, where in vitro tests were performed in the first chapter to observe the potential of the aqueous extract of cinnamon and sodium hypochlorite in the control of Alternaria alternata and the three main races of Fusarium oxysporum f. sp. Lycopersici. In the second chapter, the effects of the aqueous extract of cinnamon and the aqueous extract of clove on the control of Alternaria alternata in vitro and post-harvest of tomatoes were treated. Complete growth inhibition of the three races of Fusarium oxysporum f. sp. lycopersici and Alternaria Alternata only when using sodium hypochlorite from a concentration of 3%, and a partial inhibition with the use of cinnamon extract. Both, cinnamon extract and sodium hypochlorite solution, at concentrations above 2%, reduced IVCM values. Total inhibition of Alternaria mycelial growth under in vitro conditions was obtained using 5% clove extract. The combination of cinnamon and clove, both at 2.5 and 5%, also enabled complete inhibition of mycelial growth. In addition to the effect on mycelial growth, it was also possible to verify the inhibition of spore germination and control of the fungus in the post-harvest of tomato fruits.