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Transição agroecológica em uma abordagem sociocultural: ressignificação de práticas agrícolas, localidades e modos de vida
(Universidade Federal de São Carlos, 2021-04-29) Vaz, Renata Maria Guerreiro Fontoura Costa; Norder, Luiz Antonio Cabello; https://lattes.cnpq.br/0080353709980071; Figueiredo, Rodolfo Antônio de; https://lattes.cnpq.br/0854609216769461; https://lattes.cnpq.br/1147459500274690
Starting from the notion of transition in the field of agroecology, this thesis refers to an analysis of this process through the socio-cultural relations that constitute it, based on three case studies in the city of São Carlos. Also, the research had as objectives to understand the motivations that lead farmers to adhere to ecologically-based production methods; to analyze the new social and environmental relations resulting from the agroecological transition; to unveil the processes of redefining and creating new identities linked to agroecology; to investigate the relocation processes originated from the new conceived productive practices; and to compare the different transition processes and the respective nuances among the studied cases, taking into account the specific social and historical contexts of each reality. The hypothesis presented is that the agroecological transition, understood as a socio-cultural process triggered by multiple elements, promotes substantial changes in the social and environmental relations of the subjects who experience it, which is presented through the adoption of new ecological based productive practices, the changing of values, the building of new networks of communication and collaboration among the many social actors, the relocation, and transformation at the territorial level –in a dynamics that flows from disenchantment regarding the conventional mode of production to the enchantment by the possibilities of change that ecologically-based agriculture provides – associated with the challenges inherent to this rupture. In order to do so, the notions of “critical event”, by Veena Das, and “symbolic efficacy”, by Lévi-Strauss, were adopted as analytical references, which were adapted for the understanding of motivating and/or rupture events that lead the subjects and social groups to adhere to engagement in transition, and the process of food relocation. Interviews were conducted with the aforementioned social groups, with a focus on addressing life trajectories, in addition to participatory methodologies and participant observation. The collected narratives were examined by means of the Discursive Textual Analysis. Analysis categories were developed referring to the period that precedes the engagement in the transition process, among them, there are the origins and ways of life, the struggle for land, and motivating and/or rupture events. From that moment on, new social and environmental relations were created by these groups, analyzed based on factors such as: the search for new knowledge and adopted productive techniques; access to public policies and development projects; their own consumption and food security; redefinition of values associated with agroecological production; relocation; marketing and certification strategies; and overcome/present challenges and/or conflicts, among others. Thus, as results, the research reveals that the engagement in the agroecological transition requires specific knowledge and is related to the creation of meaning and the construction of trusting relationships, it requires constant dedication and is linked to values that go beyond monetary. A process, therefore, that is triggered by endogenous and exogenous reasons, in which the motivating events play a crucial role, in different realities of life in rural areas.
Biorrefinaria aplicada à cadeia de soja: um estudo de caso de extração verde e sustentável de isoflavonas
(Universidade Federal de São Carlos, 2021-04-29) Stahl, Aylon Matheus; Forim, Moacir Rossi; https://lattes.cnpq.br/1234565160573730; Zuin, Vânia Gomes; https://lattes.cnpq.br/5265150425993880; https://lattes.cnpq.br/0146141624567461
SOY BIOREFINERY: GREEN AND SUSTAINABLE EXTRACTION OF ISOFLAVONES. Brazil has the potential to be the world's largest producer of soybeans (Glycine max), being, in 2020, responsible for the production of 124 Mt of oilseeds. However, about 70% of the mass produced ends up being transformed into waste during the countless processing steps to generate oil, bran and grains. These agro-industrial residues have high added-value substances that can be extracted and reintegrated into the production chain using green techniques. Considering new practices aligned with sustainable development to face global challenges, such as the circular economy and the use of green and sustainable chemical processes, the concept of biorefinery presents itself as an economically viable way to achieve such objectives. This concept seeks creative processes for the extraction and transformation of this residual material that are sustainable in their core. Therefore, the investigation of by-products from soy processing is the first step to reinsert them in the production chain through the concepts of biorefinery and green and sustainable chemistry, establishing initial steps towards a non-linear economy. Thus, the extraction of two bioactive compounds from soy agro-industrial residues, the isoflavones of commercial interest daidzein and genistein, was investigated. For the extraction of these substances, two industrially scalable techniques were used: Extraction Assisted by High-Speed Homogenizer and Extraction Assisted by Ultrasound. For the optimization of procedures, the following chemometric treatments were performed: Full Factorial Design and Fractional Factorial Design, for the selection of the most relevant variables for higher extraction yields, and the Central Composite Design, for the creation of mathematical models capable of describing the best parameters for extraction. In order to make the procedure more sustainable, the extractions were performed only with mixtures of water and ethanol as the extraction solvent and, also, a chromatographic method was developed for quantification in an Ultra High Performance Liquid Chromatograph coupled to a diode array detector in the ultraviolet-visible range. In order to analyze the efficiency of resources use of the experiments, the metric "sustainable factors" was employed, considering sample mass, solvent volume, energy and time. The chromatographic method developed proved to be selective, linear and with adequate limits of detection and quantification for the extracts obtained. Among the variables studied, the sample-to-solvent ratio and the composition of the extraction solvent are the most significant for both techniques. The highest extraction yield obtained (in mg g-1) for extraction using homogenizer was 0.11 for daidzein and 0.071 for genistein; and for extraction using the ultrasonic bath it was 0.14 for daidzein and 0.082 for genistein. When analyzing the results, some experiments with slightly lower extraction yields showed greater efficiency in the use of resources considering the mass of the extracted analytes. In general, it was shown that it is possible to adopt agro-industrial residues as sources of commercially important molecules. These compounds extraction from processing residues can be carried out in an efficient and sustainable manner.
Diagnóstico das condições para implantação da Modelagem da Informação da Construção (BIM) em municípios de pequeno porte
(Universidade Federal de São Carlos, 2021-04-29) Alves, Thiago Rodrigo de Oliveira; Serra, Sheyla Mara Baptista; https://lattes.cnpq.br/8528385567782505; https://lattes.cnpq.br/1790395000927499
Building Information Modeling (BIM) methodology currently represents one of the main options for modernizing and restructuring design and construction practices for the Architecture, Engineering, Construction and Operations (AECO) sector. To provide more significant savings, efficiency, and transparency to its projects, the Federal Government prepared the National BIM Dissemination Strategy, also known as the BIM-BR Strategy. The first phase aims to apply BIM methodology to develop public projects for architecture and engineering. This study aims to verify the conditions of receptivity and existing infrastructure for implementing BIM by the management of small municipalities, that is, those with a population of fewer than 20 thousand inhabitants. A pilot study of a descriptive and exploratory case study was first carried out to seek validation for the elaborated questionnaire. The survey was carried out with nine small municipalities located in the northwest region of the State of São Paulo, verifying the conditions of receptivity, infrastructure and analyzing professionals' perceptions regarding the possible obstacles to BIM realization. Despite the possible benefits of implementing the BIM methodology, it was lying that several barriers can impede the dissemination process. The professionals' experience, financial factors, staff availability, equipment, and program requirements were some perceived difficulties in introducing the new tools. Finally, it was verified that the assistance of other government instances to carry out investments in the modernization of equipment and systems of small city halls would be crucial for the future dissemination of BIM for this group. Simple initiatives, such as the development of normative instruments, training and qualifications, and the implementation of communication management systems between sectors, can also help to improve BIM's receptivity by small-sized city halls.
Conversão de furfural sobre zeólitas (Hf, Al)-ZSM-5 hierárquicas: controle da relação de sítios ácidos de Lewis e Brønsted e seu efeito na seletividade a produtos
(Universidade Federal de São Carlos, 2021-04-29) Silva, Domingos Sérgio Araújo; Urquieta-González, Ernesto Antonio; https://lattes.cnpq.br/2389975677904655; https://lattes.cnpq.br/9207614236832829
One-pot catalytic processes using heterogeneous acid catalysts have been a promising strategy for the valorization of platform molecules from lignocellulosic biomass, such as the transformation of furfural (Fur) to γ-valerolactone (GVL), levulinic acid (AL), levulinate esters, angelic lactones, etc., which can be used for the production of biofuels and additives, "green" solvents and chemical intermediates. Among the catalysts used in these processes, zeolites with Lewis acidity (L) and Brønsted (B) have demonstrated remarkable activities for coupling reactions by Meerwein Ponndorf-Verley transfer hydrogenation (MPV), hydrolysis/ alcoholysis and lactonization, which are routes of synthesis used in the conversion of molecules derived from lignocellulosic biomass. However, in the conversion of Fu, there are still limitations to be overcome, such as the development of more selective heterogeneous catalysts and with more active and accessible sites capable of performing the stages of hydrogenation by MPV and hydrolysis/alcoholysis. For MPV transfer hydrogenation reactions, zeolites with incorporated tetravalent metals (Ti, Sn, Zr, and Hf) have shown high activities, with those Hf-incorporated being the most active. In this context, this work proposes to develop hierarchical ZSM-5 zeolites containing L acid sites generated by Hf and B acid sites to be used as catalysts for the conversion of Fur in the presence of 2-propanol to more valuable products. For this purpose, hierarchical ZSM-5 zeolites with acidity of L and B were prepared by post-synthesis strategies of desilication, dealumination, and incorporation in liquid phase of Hf4+ cations. Analyses from XRD, DRS-UV-Vis, N2 physisorption, and FTIR in situ with adsorbed pyridine proved that the synthesis methods employed are capable to obtain micro-mesoporous ZSM-5 zeolites with both types of acid sites. In the catalytic tests, the hierarchical zeolites were able to catalyze the Fur conversion by in series reactions, generating mainly products such as GVL, AL, isopropyl levulinate (LI), β-angelic lactone (β AgL), and 2-(isopropoxymethyl)furan (2-IPF). The distribution of these products was strongly affected by the textural and acidic properties of the materials. The control of the B/L ratio proved to be essential in obtaining more efficient catalysts. To make this control, different strategies were used, such as heat treatments, changes in the degree of incorporation of the metallic cation, and physical mixtures of solids with L or B acidity. For the thermally treated mesoporous zeolites (Hf, Al)-ZSM-5, the selectivity to GVL decreased with the increase of the calcination temperature of the catalyst, and up to 450 °C its selectivity remained constant. The adjustment of the B/L ratio obtained with the change in the textural properties of the zeolite and subsequent insertion of Hf allowed changing the accessibility of the precursor of the metallic cation and its degree of incorporation, resulting in catalysts with different activities and selectivities. Physical mixtures of protonic hierarchical zeolites with HfO2 were also efficient for controlling the B/L ratio in a simpler and faster way. Using 30 mg of a micro-mesoporous zeolite (Hf, Al)-ZSM-5 containing 1.53 μmol of L and 4.14 μmol of B, it was possible to convert about 200 μmol of Fur after 40 h of reaction at 120 °C, obtaining GVL and LI yields of 35 and 23%, respectively. Catalytic tests varying the reaction conditions allowed to verify that the yields and selectivities to products of interest for the sectors of biofuels and chemical intermediates such as GVL and LI can be improved with the increase of the reaction temperature, catalyst mass and adjustment of the B/L ratio. In addition, catalyst reuse tests showed that the micro-mesoporous ZSM-5 zeolite having B and L sites generated by Hf maintained its catalytic activity until at least four consecutive reaction cycles. In general, the strategies presented were promising for the development of potential catalysts for the reactions of transformation of furan molecules into highly demanded products, such as biofuels, additives and chemical intermediates.
Análise da viabilidade técnica e econômica da integração do processo de recuperação de etanol por arraste (stripping) com CO2 na indústria sucroenergética
(Universidade Federal de São Carlos, 2021-04-29) Souza, Fabricio Menezes de; Queiroz, João Paulo Silva; https://lattes.cnpq.br/7316247674511327; Cruz, Antonio José Gonçalves da; https://lattes.cnpq.br/1812806190521028; https://lattes.cnpq.br/6867078399350708
Brazil is the world's largest sugarcane ethanol producer which puts the country in a stand-out position among the bioenergy producers. Ethanol is an important biofuel in the renewable energy matrix. In 2017, the Brazilian Government launched the National Biofuel Policy, named “RenovaBio”. With this program, it is expected an increase in production process efficiency and a reduction in the by-product generated. To achieve these goals, producing a more concentrated wine in the fermentation stage is a good strategy. However, in the fermentation process, ethanol itself is a limiter, since it is a toxic compound to the yeasts, which reduces or even stops the cell growth rate when high concentrations are achieved. To overcome this problem, ethanol can be produced and removed from the fermentation medium as it is formed. Thus, the objective of this work was to analyze ethanol removal from the fermentation broth using the carbon dioxide striping technique. The ethanol removed by the carbon dioxide stream is recovered by absorption using monoethylene glycol. This integrated process (removal and recovery process) was implemented and evaluated in an industrial autonomous and annex distillery implemented in the Aspen Plus process simulator. The implementation of extractive fermentation in the conventional ethanol production process increased the electric energy production by 9.4% besides reduced the amount of vinasse by 0.5 liters per liter of ethanol compared to the conventional autonomous distillery. Furthermore, the sugar recovery as ethanol was increased by 1.07%. These results showed that extractive fermentation becomes economically feasible when low specific stripping gas flow rates are used in the process. However, the recovery of the entrained ethanol and the requirement of the energy to compress the carbon dioxide stream were the main factors that impact the process viability. The first one had a positive impact whereas the second one exhibit a negative impact.
Fotoconversão de CO2 em produtos com valor agregado
(Universidade Federal de São Carlos, 2021-04-29) Faria, Ana Luiza Alves; Nogueira, Francisco Guilherme Esteves; https://lattes.cnpq.br/8117497993539795; https://lattes.cnpq.br/1261471786703960
In recent decades, due to population and industrial growth, the energy demand has increased significantly. However, much of the energy consumed comes from burning fossil fuels, which emit large amounts of gases that can increase the temperature of the earth. Among these gases, carbon dioxide (CO2) stands out as one of the main causes of the greenhouse effect. Thus, the need to develop new economically and energetically viable technologies for energy production through clean and sustainable routes is essential. Among these technologies, the CO2 photoconversion process (“artificial photosynthesis”) in products with added value can be highlighted. However, the vast majority of semiconductors developed to date, for this purpose, have a high rate of recombination of their photogenerated electron/hole pairs, thus reducing the efficiency of the process. In order to improve the photocatalytic efficiency, this project aimed to develop semiconductors based on niobium pentoxide (Nb2O5) modified with iron (Fe) or copper (Cu) for photoreduction of CO2, aiming to increase the photocatalytic efficiency of the material through the reduction in the rate of recombination of the photogenerated electron/hole pairs. For this, semiconductors based on Nb2O5 were synthesized by the oxidizing peroxide method under hydrothermal treatment. The depositions of Fe or Cu were carried out by the method of sputtering ("magnetron sputtering") since this technique allows the deposition of nanoparticles with a high degree of purity. The addition of Fe or Cu nanoparticles on the Nb2O5 surface significantly reduced the rate of recombination of the photogenerated electron/hole pairs, due to the greater spatial separation of the photogenerated charges through the formation of heterostructure between the materials, which resulted in a significant increase in CO2 photoconversion. The materials modified with Fe showed high production of carbon monoxide (CO) (356.6 µmol/g). In addition, the calcination of the Nb2O5 semiconductor and its modification with Fe favored the production of methane (5.13 µmol/g), methanol (75.78 µmol/g) and acetic acid (69.07 µmol/g). On the other hand, Cu-modified materials showed a high production of methane (52.5 µmol/g) and methanol (628.01 µmol/g), compared to Nb2O5 and the catalysts modified with Fe The higher conversion efficiency for materials modified with Cu is related to the ability of Cu to trap the photogenerated electrons in the conduction band of Nb2O5.
Efeito da exigência de respostas ecoicas durante o ensino de discriminação auditivo-visual na emergência de tatos em crianças com autismo
(Universidade Federal de São Carlos, 2021-04-29) Carneiro, Anne Caroline da Costa; Cortez, Mariéle Diniz; https://lattes.cnpq.br/7927746584626515; https://lattes.cnpq.br/6394261833355301
Many studies have been developing procedures to teach verbal repertoires to children diagnosed with Autism Spectrum Disorder (ASD). The purpose of this study was to evaluate the efficacy of a auditory visual discrimination training with and without echoic response requirement in the emergence of tacts in children with autism, and evaluate if the moment in which the response was required (e.g., after the auditory stimulus was presented meanwhile children attempted to the visual stimulus) could lead to the emergence of tact responses. 3 children diagnosed with ASD participated in the study and were exposed to the following experimental conditions: 1) Pretest tact probe, with the purpose of evaluate the participant's entry repertoire and choose the target stimulus, 2) Auditory visual discrimination training with echoic response requirement to one set of stimulus in which the participant was required to emit the echoic response after the auditory stimulus was presented meanwhile children attempted to the visual stimulus, 3) Auditory visual discrimination training without echoic response requirement to another set of stimulus, and, 4) posttest tact probe to evaluate the effects of echoic responses requirement in the emergence of tacts. An alterned treatment design was implemented allowing the evaluation inter and intra participants. The results demonstrates a high level of tact emergence for all participants suggesting that echoic responses requirement in an specific moment in which it is emitted could play an important role in the emergence of tacts in as auditory visual discrimination training procedure.