Repository logo
Communities & Collections
Entire repository
About
English
العربية
বাংলা
Català
Čeština
Deutsch
Ελληνικά
Español
فارسی
Suomi
Français
Gàidhlig
ગુજરાતી
हिंदी
Magyar
Italiano
Қазақ
Latviešu
മലയാളം
मराठी
Nederlands
ଓଡିଆ
Polski
Português
Português do Brasil
Русский
Srpski (lat)
Српски
Svenska
తెలుగు
தமிழ்
Türkçe
Yкраї́нська
Tiếng Việt
繁体中文
Have you forgotten your password?
  1. Home
  2. Browse by Date

Browsing by Issue Date, starting with "2023-02-27"

Filter results by year or month
Now showing 1 - 20 of 6321
  • Results Per Page
  • Sort Options
  • Loading...
    Thumbnail Image
    Item type:Item,
    Efeitos da pandemia de COVID-19 na saúde dos trabalhadores de hospitais universitários
    (Universidade Federal de São Carlos, 2023-02-27)
    Vieira, Suelen Debora Fontana
    ;
    Oliveira, Ana Beatriz de
    ;
    https://lattes.cnpq.br/104954775918655
    ;
    https://lattes.cnpq.br/5292442725088804
    The Covid-19 pandemic has brought significant changes in the professional and personal life of hospitals workers, especially those who perform direct assistance to the population. Many workers were physically and emotionally exhausted, which contributes to the absenteeism due to several factors besides the contact with the Covid-19 virus. These workers can experience physical and mental overload and acquiring diseases by their own work environment in which they are inserted, facing daily exhausting situations such as dealing with death, suffering and pain. In periods of pandemic, these situations get worse by increased demand in hospitals and lack of structure to meet all the patients. As literature shows, sanitary outbreaks and pandemics periods are cyclic. In this context, it is relevant to have knowledge about the physical and mental health of these workers and the profile of absenteeism of this population. The aim of this study was to evaluate the data of absenteeism considering the care and administrative sectors of university hospitals in Brazil between 2018 and 2022, and to evaluate, in a sample of subjects of this population, the occupational fatigue, the work engagement, the symptoms of the Burnout syndrome and the musculoskeletal symptoms, to understand the effects of Covid-19 pandemic on the health of these workers. The survey was conducted in two stages, with workers from both the care and administrative sectors of university hospitals in Brazil (allocated by region), who were active in combating COVID-19 pandemic for at least 6 months. In the first stage, an analysis of the monthly mean of absenteeism by region, between 2018 and 2022 was performed. In addition, the classification of the absences according to the International Disease Classification System - 10th review, was presented. In the second stage, a survey was conducted through online and printed questionnaires, using the following instruments: a sociodemographic questionnaire, the Need for Recovery Scale, the Maslach Burnout Inventory-Human Services Survey (MBI-HSS), the Utrecht Work Engagement scale (UWES) and the Nordic Musculoskeletal Questionnaire (NMQ). The results of the first stage of the research showed that in 2020 and 2021 there was an increase in the absenteeism and in the monthly mean of absences per worker and hospital in all regions of Brazil. The most frequent health problems corresponded to infectious and parasitic diseases and respiratory diseases. In the second stage, the results of the questionnaires showed that 65.35% of workers had a high need for recovery. In addition, 31.37% had symptoms of the Burnout syndrome. Considering the engagement at work, 44.44% had a medium classification and a low percentage of the evaluated workers had engagement classified as “high” and “very high”. Considering the musculoskeletal symptoms, for the administrative sector the most affected region was the neck and for the care sector, the most affected region was the low back. In addition, the results show that musculoskeletal symptoms have developed or worsened for most workers. The results showed that in the period of the Covid-19 pandemic, both the physical and mental health of university hospitals workers presented quite negative aspects, evidenced by the alarming percentage of workers with fatigue, musculoskeletal symptoms, symptoms of burnout syndrome and the low percentage of workers with high engagement at work. These findings can guide the elaboration of prevention and treatment strategies focused on this population, especially when considering challenging contexts, such as pandemic periods. In addition, new studies seeking to evaluate the physical and mental health of these workers in the long term are still necessary.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Oxidação do metano em metanol: efeito da natureza do oxidante na estrutura da espécie ativa em Cu-FAU e Cu-CHA
    (Universidade Federal de São Carlos, 2023-02-27)
    Vieira, Jussara Vitória Reis
    ;
    Lima, Patrícia Moreira
    ;
    Bueno, José Maria Corrêa
    ;
    https://lattes.cnpq.br/0157452280626031
    ;
    https://lattes.cnpq.br/7379453700180071
    The direct oxidation of methane to methanol is carried out with metal-zeolite catalysts in three steps: (I) oxidation of metal oxide with O2; (II) partial oxidation of methane to methanol using active site oxygen, and (III) methanol desorption with water vapour. Generally, the conventional process studied in the literature is carried out in cycles with temperature changes. However, the isothermal cycle is preferable from an economic and operational point of view. Understanding the active species in catalysts is important for the development of materials that allow higher methanol yields. Although the literature presents excellent studies on this reaction, the process has not yet left the laboratory scale. It is necessary to investigate changes in the process that allow improvements to achieve a future viability. Therefore, the general objective of this work is to propose the use of CO2 as an oxidant in an isothermal process at high temperature in the partial oxidation reaction of methane to methanol using the zeolites Cu-FAU and Cu-CHA, and through the technique of diffuse reflectance spectroscopy in the ultraviolet and visible region to compare the effect of this oxidant on the structure of the active species in relation to the traditionally used oxidant, oxygen. The catalysts showed excellent performance in the isothermal process (400 °C), using CO2 as an oxidant. The results achieved were 140 and 132 µmol MeOH/gcat, for Cu-FAU and Cu-CHA, respectively. Through DRS UV-vis in situ it was possible to verify the presence of two species that are able to activate methane in Cu-FAU using CO2 -[Cu3(µ-O)3]2+ and [CuOH]+. However, the use of oxygen only species [CuOH]+ is observed. The Cu-CHA showed only species [CuOH]+ in both oxidants. The results suggest that the combination of oxidant and zeolite structure influences the formation of the active species. The treatment in CO2, in addition to providing active oxygen for the formation of the active site, allows the self-reduction of a copper fraction (Cu2+ → Cu+). The Cu+ formed can migrate into the Cu-FAU zeolite structure and recombine with other atoms to form [Cu3(µ-O)3]2+. The proposal to use carbon dioxide is a step forward in contributing to the study of the direct partial oxidation of methane to methanol.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Study of different curcumins for staphylococcus aureus antimicrobial photodynamic therapy
    (Universidade Federal de São Carlos, 2023-02-27)
    Joshi, Priyankaben Niravkumar
    ;
    Blanco, Kate Cristina
    ;
    https://lattes.cnpq.br/9029359807019219
    ;
    Bagnato, Vanderlei Salvador
    ;
    https://lattes.cnpq.br/4947860249518663
    Curcumin is a Photosensitizer (PS) used for microbial inactivation when light is applied. Antimicrobial photodynamic therapy (aPDT) is a promising approach for treatment of bacterial infections, combining a PS + light to produce reactive species of oxygen that kills the microorganisms. This project aims to analyze the effectiveness of different in vitro curcumin formulations for PDT protocol against S.aureus. In this study, we compared Synthetic curcumin (Cur-Syn) with Nanoencapsulated Curcumin (Cur-Nano), as well as curcumins modified with Chlorine (Cl), Selenium (Se), and Iodine(I) (Cur-Cl, Cur-Se, Cur-I). Staphylococcus aureus (ATCC 25923) was incubated with Curcumin and irradiated at 450nm to evaluate the effects of aPDT. Mortality was measured by counting the surviving colony forming units per milliliter (CFU/ml). The Uptake of photosensitizer (PS) and photobleaching were compared for the curcumins of interest. Our in vitro results suggest that Nanoencapsulated curcumin wasn't able to release curcumin and attack the bacteria when compared with Cur-Syn in the same conditions. Also, of the three modifications of Cur-Cl, Cur-Se, Cur-I; Cur-Se, had detrimental effect on bacteria. However, the rate of uptake and photobleaching capacity of Cur-Syn and Cur-Se were found to be quite similar. Our results suggest that curcumin modifications influence the effect of the molecule on PS.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Sobre viver em Maceió: atos de vida de pessoas LGBTQIA+ em situação de rua na perspectiva da terapia ocupacional social
    (Universidade Federal de São Carlos, 2023-02-27)
    Silva, Rodrigo Gonçalves Lima Borges da
    ;
    Malfitano, Ana Paula Serrata
    ;
    https://lattes.cnpq.br/1462870858750395
    ;
    https://lattes.cnpq.br/4189886841192586
    Introduction: The reality of homeless people living in marginality and precariousness is marked by poverty, survival process and resistance. This situation was aggravated as a result of the COVID-19 pandemic, which covered the worldwide territory. Considering the social markers of differences, the social issue, the social structure of hierarchies between individuals and social occupational therapy, it is relevant to understand the ways of life of different social groups, as well as homeless LGBTQIA+ people, in view of understanding multiple lives and survival, discussing professional actions with this population. Objective: To understand life moments of homeless LGBTQIA+ people during the COVID-19 pandemic, in Maceió/AL, Brazil. Methods: Starting from institutional spaces, as a "Consultório na Rua", a service of the Health Department of the City of Maceió, in Alagoas, and also from two non-governmental shelters for LGBTQIA+ people, we invited seven people to present us some of their lives through interviews, with data complemented by participant observation in the services and informal conversations. Results: The fields data demonstrated ruptures and creations of new social support networks, in processes that permeate social marginalization and precariousness. Going to the streets was described as a critical event caused by the rupture with the family, due to conflicts arising from the experience of a dissidence of gender and sexuality, marked in stories that go through poverty as a condition of life. From life on the streets, social institutions are important components of the social support network, permitting access to basic necessities, like food and a place to sleep. In this context, dreams are woven, at times as an escape from the precarious reality, at other times as the creation of possibilities and facing reality, mixing strategies for the maintenance of their lives, revealing how to live. The context of the pandemic aggravated the conditions for the maintenance of basic survival necessities, and all the collaborators of this study were already living on the streets when the pandemic started. Discussion: As a reading key for the results, "acts" were drawn, understood as moments of life that exist between the birth and death of the human being. The "acts" are a poetic way of reading reality to think strategies for professional action. They are: how to get together; how to exist; how to survive; about living in the pandemic; and time to dream, which present how to survive in Maceió, AL during the pandemic and the creative possibilities of life beyond marginalization and ruptures. Conclusion: To understand the ways of life through the proposition of "acts" configures itself as a possibility of understanding the ways of life of LGBTQIA+ people living on the streets, based on their narratives, which describe the possibilities of creating strategies for survival, as well as the living during the pandemic. The reflections on life moments through acts are expected to collaborate with new theoretical and conceptual perspectives for the development of professional actions, especially for occupational therapists, with this population.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Esperança e promoção da saúde mental de mães de prematuros internados em Unidade de Terapia Intensiva Neonatal
    (Universidade Federal de São Carlos, 2023-02-27)
    Albers, Mariana Barbosa Ferreira
    ;
    Zerbetto, Sonia Regina
    ;
    https://lattes.cnpq.br/1282433435871232
    ;
    https://orcid.org/0000-0002-2522-1948
    ;
    https://lattes.cnpq.br/5591675662670636
    The birth of premature infants can lead to experiences of hospitalization in the Neonatal Intensive Care Unit for mothers and their families, where specialized care is provided but negative experiences are also encountered. This fact can trigger negative impacts on these women, potentially affecting their mental health. In this context, hope has been recognized and considered as a resource for care, contributing to adaptation and resilience. The general objective of this study was to analyze the perceptions and experiences of hope among mothers of premature newborns hospitalized in Neonatal Intensive Care Units (NICUs) and its repercussions on their mental health during the COVID-19 pandemic. The specific objective was to analyze the perception of mothers of premature infants hospitalized in NICUs regarding inhibiting and promoting factors of hope during the pandemic context. The study employed a qualitative approach, conducting face-to-face semi-structured interviews with twelve mothers of premature infants hospitalized in a Neonatal Intensive Care Unit in a city of a State of São Paulo , where the mother is not allowed to stay in the unit and visiting hours are restricted. During the research period, which took place during the pandemic, visits were limited to the parents of the premature infants. Thematic reflective analysis was the adopted method, anchored in the theoretical construct of Dufault and Martocchio's Model of Hope. The study was analyzed and approved by the Research Ethics Committee for Human Beings of a Federal University in a city of São Paulo State, with opinion number 5,129,909 in the year 2021. The results emphasized that the process of hope is based on life circumstances that generate learning in a context that promotes coexistence with ambivalent feelings. Hope presented various conceptual meanings for these mothers; however, it constituted a process that is oriented towards the future while holding expectations of something possible, even in the face of uncertainties. In this context, women recognized situations/factors that promoted or inhibited hope. Sources of hope were represented by people in the family circle, healthcare professionals, religious beliefs, and improvement in the neonate's clinical condition. Inhibiting factors for hope were related to the mother's perception of the fragility of the neonate, including deterioration in the premature infant's clinical condition, physical suffering, as well as concerns about future impairments and damages to the physical and mental development of the premature newborn. It can be concluded that in recognizing healthcare and nursing teams as sources of hope, these professionals require relational and intrapersonal competence and skills to assist patients in the process of identifying factors and sources that promote or inhibit hope. Therefore, to achieve this objective, it is necessary to incorporate hope as a thematic and clinical practice in the training process of these professionals. Keywords: Hope; Mental Health; Mothers; Premature Newborn; Neonatal Intensive Care Units; COVID-19.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Fatores preditivos do prognóstico desfavorável em pessoas com dor patelofemoral: uma revisão sistemática
    (Universidade Federal de São Carlos, 2023-02-27)
    Demarchi, Samantha Janaina
    ;
    Serrão, Fábio Viadanna
    ;
    https://lattes.cnpq.br/8137335642635433
    ;
    https://lattes.cnpq.br/2880103940680669
    Identifying predictive factors of patellofemoral pain (PFP) prognosis is important for clinical decision making. Although previous systematic reviews have identified some predictive factors of a poor prognosis, they included studies with inadequate designs to answer the research question and, thus, their results should be considered with caution. To identify, from observational prospective cohort studies, baseline characteristics of people with PFP that are predictive of a poor prognosis. Electronic search performed at PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Embase, SPORTDiscus, SCOPUS, Web of Science and WorldCat databases (up to April 2022). Only observational prospective cohort studies investigating baseline characteristics of people with PFP that were predictive of a poor prognosis were included. The methodological quality of the included studies was assessed using the Quality in Prognosis Studies Tool (QUIPS). This review was developed according to the guide for systematic reviews of studies of prognostic factors and reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol (PRISMA-P) guidelines. Only one low risk of bias study was included. At one-year follow-up, the presence of a low/middle education level, poor health, the presence of bilateral symptoms and self-reported swollen knee were independently associated with persistent knee symptoms. A paucity of observational prospective cohort studies investigating baseline characteristics of people with PFP that are predictive of a poor prognosis was identified. The results of this review may assist physical therapists in clinical decision making. However, as only one study was included, further observational prospective cohort studies are needed to confirm this result.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Efeitos do exercício físico na função muscular do joelho, dor e qualidade de vida em mulheres pós-menopausadas com osteoartrite de joelho: uma revisão sistemática com metanálise
    (Universidade Federal de São Carlos, 2023-02-27)
    Wolf, Débora Faria
    ;
    Serrão, Paula Regina Mendes da Silva
    ;
    https://lattes.cnpq.br/2917658715637353
    ;
    https://lattes.cnpq.br/5632478948196525
    Objective: To investigate the effects of physical exercise on muscle function of the knee, pain and quality of life in postmenopausal women with knee osteoarthritis (OA). Methods: An electronic search was conducted of the PubMed, Embase, Web of Science, Cochrane Library, LILACS and PEDro databases for relevant articles published up to February 2023. Only randomized clinical trials with interventions involving physical exercise of any modality in postmenopausal women with knee OA were included. This review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the Cochrane Recommendations. Methodological quality of the studies selected was assessed using the PEDro scale and the evidence was synthesized using the Grading of Recommendations, Assessment, Development and Evaluation scale. Results: Among the 146 articles identified, five were included in the present systematic review and enabled meta-analysis of the outcomes physical function, pain and stiffness. Treatment with physical exercise proved effective at improving physical function compared to the control based on the distance traveled on the Six-Minute Walk Test. However, no difference was found when assessed based on self-reports. No differences between the treatment and control groups were found for the outcomes pain or stiffness. Meta-analysis was not possible for the outcomes muscle function of the knee or quality of life due to insufficient data. Conclusion: Physical exercises can contribute to the improvement in physical function in postmenopausal women with knee OA when assessed by the distance travelled, but not by the self-report assessment
  • Loading...
    Thumbnail Image
    Item type:Item,
    O planejamento nacional-desenvolvimentista no Brasil (1946-1964).
    (Universidade Federal de São Carlos, 2023-02-27)
    Nogueira, Johnny Daniel Matias
    ;
    Cepêda, Vera Alves
    ;
    https://lattes.cnpq.br/4917331423373631
    ;
    https://lattes.cnpq.br/3185164992645890
    The debate on state planning in Brazil mobilized a group of intellectuals and political actions with the aim of diagnosing the structural barriers of the economy and, thus, overcoming the condition of underdevelopment, promoting industrialization. The purpose of this study is to analyze how the theme of planning evolved in three analytical movements: in the international context, at the national level and in the thought of Celso Furtado, during the period from 1946 to 1964. The choice of this time period is justified for several reasons: first, due to the context of Brazil's redemocratization after 15 years of the Vargas government; second, by the international trend towards planning, influenced by the transformations resulting from the economic crisis at the beginning of the century; thirdly, due to the national scenario that saw the proposal of three economic plans, one of them led by Celso Furtado himself; fourth, due to the exhaustion of the laissez-faire model after two World Wars and the Great Depression of 1929, which required more vigorous intervention from the State to replace the market as a promoter of development; and, finally, due to the determination of industrial entrepreneurs, bureaucracy and intellectual sectors to complete the country's transition from an agrarian-export model to an urban-industrial nation. This study falls within the field of studies of Brazilian political thought and seeks to shed light on the complex evolution of state planning in Brazil during this critical period.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Vontade política, razão comunicativa e educação: análise sobre o sentido político-educacional da reforma do ensino médio - Lei 13.415/17
    (Universidade Federal de São Carlos, 2023-02-27)
    Venturelli, Sandra Olades Martins
    ;
    Gomes, Luiz Roberto
    ;
    https://lattes.cnpq.br/4768579559449929
    ;
    https://orcid.org/0000-0002-8867-7897
    ;
    https://lattes.cnpq.br/8965126677894347
    This thesis aims to analyze the formation of political will in contemporary society within formal education. Considering the importance of developing a critical potential for the formative process, we analyze the potentialities of a political will formation in the educative process that can be constituted in an emancipatory action and face the domain of strategic and technical-instrumental rationality over discursive rationality. We evaluate that emancipation in the process of political will formation in schools might be related to the decision processes of the institutions that wield power, such as the State. Its actions should aim to allow social interaction and build accessible communication without undiscussed impositions but consensually evaluated instead. As the determination of Educational Public Policies orients formal education (schooling), we search to identify the rational fundaments which sustain the educational-political processes once we consider being necessary rationality created and expressed by intersubjectivity. We analyze the hasty approval procedures of High School Reform, Law nº 13.415/17, to identify if there were any deformation of emancipatory projects in the education system, favoring the relations with the market and neoliberal projects. For this thesis's development, we employ the conceptual theoretical fundaments of Jürgen Hamermas's thinking, which offer indispensable elements to comprehend the structure that holds the rationality of the modern world. Through bibliographic research, we develop the theoretical framework and advance on constructing the necessary concepts for this thesis understanding. We conducted the documental analysis through publicized institutional documents referring to educational policies and curriculum orientation, such as laws, decrees, and provisional measures.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Uma terapia filosófica da Modelagem Matemática na Educação Matemática
    (Universidade Federal de São Carlos, 2023-02-27)
    Costa, Daniana de
    ;
    Caldeira, Ademir Donizeti
    ;
    https://lattes.cnpq.br/8185048034258055
    ;
    https://lattes.cnpq.br/8838183313851024
    Based on Ludwig Wittgenstein's therapeutic philosophy, the aim is to clarify conceptual confusions that exist in possible images related to what is described about Mathematical Modelling in Mathematics Education as found in dissertations and theses developed in Brazil. The research approach is qualitative, and it is classified as exploratory and bibliographic, when the uses of the linguistic expressions, mathematical modelling and mathematical model are explored in an empirical material constituted by forty-seven Brazilian dissertations and theses from the period 1976 to 2022. The interpretation of the use of these linguistic expressions occurred in the construction of three images: 1) in Modelling, the student discovers mathematics inserted in some extralinguistic reality; 2) the mathematical model is an underlying representation of empirical reality; 3) in Modelling, mathematical knowledge would originate in mental constructions. Inspired by Wittgenstein's therapy, possible clarifications of the conceptual confusions imbricated in these images were initiated. Concerning the first image, two conceptual confusions were verified, indicating that in Modelling the nature of mathematical statements is taken as equal in nature to the statements of the empirical sciences, and the conclusions of the students (rediscoveries or personal discoveries) in Modelling are of empirical nature. As a possible clarification, it is argued that mathematical statements are of a normative nature that enable the understanding of the empirical world. In this sense, the student will be able to do Modelling from the moment he knows the rules of mathematics and of Modelling itself and is able to act guided by these rules. As for the second image, the confusion is that there would be an isomorphism between the mathematical model and the empirical reality. To clarify, it is argued that, from a Wittgensteinian perspective, the mathematical model can be conceived as representation (Darstellung), such as a paradigm, a linguistic object that organizes and gives meaning to empirical experience. As for the third image, the conceptual confusion is that the mathematical knowledge constructed in the Modelling is mental representations (Vorstellungen) of mathematical concepts. It is made explicit that there can be a kind of construction of mathematical knowledge initiated by the various uses of mathematical rules presented to the student. Paying attention to the use of the linguistic expressions mathematical modelling and mathematical model in the empirical material of this research, it is pointed out that in Modelling there is an exclusive use of the referential conception of language related to the empiricist and intuitionist meanings of Mathematics.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Intervenções para mudança do comportamento de movimento e o desenvolvimento de uma plataforma para o monitoramento de atividade em reabilitação (MARe) para indivíduos pós-acidente vascular cerebral
    (Universidade Federal de São Carlos, 2023-02-27)
    Oliveira, Simone Garcia de
    ;
    Nogueira, Samuel Lourenço
    ;
    https://lattes.cnpq.br/2287847504423307
    ;
    Russo, Thiago Luiz de
    ;
    https://lattes.cnpq.br/2755480908047791
    After a stroke, it has been identified that most individuals adopt a lifestyle with sedentary behaviors (SB) and low levels of physical activity (PA), which can cause damage to the individual, accentuating disabilities, limiting the performance of daily activities, restricting participation and society, and increasing the risk of new cerebrovascular events. Movement behavior (SB and PA) is an area of great interest in Neurofunctional Physiotherapy. Thus, interventions aiming to reduce SB and increase PA after stroke have been studied in the last decades and shown promising results. However, most studies end up using measurements of PA and SB self-reported by patients, thus not providing sufficiently reliable objective data to reflect the person's daily context. Thus, accelerometers and other motion sensors integrated into inertial measurement units (IMUs) bring important technological advances to rehabilitation, with systems capable of continuously detecting aspects of real-world mobility. However, due to asymmetry and decreased gait speed in this population, many of these approaches do not provide valid and reliable metric properties for measuring movement behavior in individuals with stroke. Given this, this thesis aimed to systematically synthesize the literature on the effectiveness of interventions, which used outcomes based on the use of activity monitors, to reduce SB and increase PA levels. In addition, it aimed to evaluate the measurement properties of a platform for activity monitoring in rehabilitation (AMoR) for post-stroke individuals. The first study (Manuscript 1) was a systematic review with meta-analysis, in which searches of the main databases of the area were performed. Data extraction was performed and analyses of the methodological quality, risk of bias and quality of evidence of the included studies were evaluated. Seventeen studies involving 1,031 patients were included in this systematic review. The meta-analysis showed that in post-stroke individuals, there is evidence of high quality and statistical significance in favor of exercise interventions combined with behavioral change techniques in the acute/subacute phase and in favor of exercise-only training in the chronic phase for increasing the number of daily steps. Overall, the risk of bias in the included studies was low. The second study (Manuscript 2), was a cross-sectional observational study, with 21 individuals in the chronic phase of post-stroke, who used the AMoR platform, during activities of daily living (ADLs), while being monitored by a video camera. These activities were filmed in a simulated environment. The validity and reliability of measurements between the platform and cameras were analyzed by Spearman's correlation coefficient and mean absolute percentage error (MAPE), and intraclass correlation coefficient (ICC) and Bland-Altman plot analyses, respectively. The following variables were considered: number of steps, time spent sitting/lying, and postural change from sitting to standing (Sit-Std) and standing to sitting (Std-Sit). The AMoR platform showed very high correlation values for number of steps and time spent sitting/lying and high correlation for postural change from Sit-Std and Std-Sit. An error percentage above 5% was observed only for the Sit-Std postural change (7.13%). The ICC values show excellent agreement of the AMoR platform with the video for number of steps and time spent sitting/lying and good agreement for Sit-Std and Std-Sit postural change. Difference values of the AMoR platform and video for step counting, sitting/lying time and postural change were within the limit of agreement in the Bland-Altman plot analyses. In conclusion, this thesis showed that: 1) by the literature analysis, the combination of exercise with behavioral interventions is associated with a significant increase in PA level in the acute and subacute phase after stroke. Furthermore, exercise-based interventions are associated with a significant increase in daily steps in chronic post-stroke participants; 2) the AMoR platform was valid and reliable for counting number of steps, time spent sitting/lying and identification of Sit-Std and Std-Sit postural changes during tests in a simulated environment in post-stroke individuals.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Conflitos, convergências e possibilidades de integração entre o estudo de impacto de vizinhança e o licenciamento ambiental municipal: estudos de caso em cidades médias paulistas
    (Universidade Federal de São Carlos, 2023-02-27)
    Abreu, Emanoele Lima
    ;
    Peres, Renata Bovo
    ;
    https://lattes.cnpq.br/6045407453925020
    ;
    https://lattes.cnpq.br/1167798136607835
    The Local Environmental Licensing (LEL) and the Neighborhood Impact Assessment (NIA) are instruments that aim at licensing activities in urban territory and represent an attempt to articulate urban and environmental problems, despite having legislation that derives from different concepts. This thesis researched the State of São Paulo, as it is growing in terms of the application of the LEL and NIA. This thesis aimed to advance the investigation of the relationship between urban and environmental regulation. We used qualitative research methods and resorted to three approaches. The first approach refers to bibliographic research, carried out through Systematic Literature Review (SLR). At SLR we investigate theoretical, conceptual and methodological approaches to LEL and NIA. In the second approach, we use multiple Case Studies, we seek to understand the application of these instruments in the four (04) cities and investigate the existence of an integrated urban environmental management in their territories. In the third, we interview stakeholders and public servants from the case study cities. Through the SLR, we found that the LEL and the NIA are instruments that need integration for urban environmental management in the country. However, there are still challenges of a technical, theoretical-conceptual and political-administrative nature that prevent this connection. In the Case Studies, three (03) cities studied did not have a specific law for NIA. In these cities, the Master Plan or the Land Use and Occupation Law are responsible for regulating NIA, with information complemented by terms of reference. Regarding the LEL, all cities had a specific law and, with the exception of Jundiaí, carried out environmental licensing through authorization by the state environmental agency. As for the interviews with stakeholders, we mapped the following related conflicts: the attribution of NIA and LEL instruments; the social agents involved; and the attribution of the state in the application of these instruments. Inserting the environmental dimension into local urban policies still faces political and institutional obstacles. The origin of these obstacles has deep roots in a series of conflicts of interest between different local social forces. Diagnosing, identifying and recognizing such conflicts is essential for the development of local urban-environmental governance.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Satisfação dos cuidadores familiares à intervenção de telerreabilitação e de acompanhamento para pessoas idosas com demência: ensaio clínico randomizado
    (Universidade Federal de São Carlos, 2023-02-27)
    Gerassi, Renata Carolina
    ;
    Ansai, Juliana Hotta
    ;
    https://lattes.cnpq.br/1028110691131464
    ;
    https://lattes.cnpq.br/4379315617361631
    Among the so-called chronic non-communicable diseases and syndromes that commonly affect older people, dementias stand out, for having characteristics that do not affect only the sick individual. They extend to the entire family structure and to society, with great psychosocial and economic impact. Faced with social distancing as a protective measure against the pandemic of COVID-19, many older people and caregivers have had to learn to deal with the use of Information and Communication Technologies. Tele-rehabilitation is a long-distance health care access alternative that has been used extensively during the pandemic of COVID-19 and can help access health care and quality of life for older adults with dementia and their caregivers without posing a risk of contagion from COVID-19. The satisfaction factor with telerehabilitation is an important focus of research, as it is a key aspect to measure the quality of care and assess the relevance of these services provided. The present study aimed to verify caregiver satisfaction to a Telerehabilitation Program and to Remote Follow-up in older adults with dementia and their caregivers; to compare caregiver satisfaction to telerehabilitation and Remote Follow-up in older adults with dementia and their caregivers during social distancing by the COVID-19 pandemic; To verify which factors interfere in the caregiver's satisfaction to the interventions, including the factors related to the older adults with dementia (age, sex, comorbidities, mental health status - cognition and behavior and functional capacity) and factors related to the caregiver (age, sex, years of study, marital status, family monthly income, whether he/she shares the care with someone else and how many hours of the day care is given to the older adults, mental health status - cognition and behavior, quality of life and burden). This research has a quanti-qualitative approach and is part of a randomized clinical trial only post-test with a control group, with blinding of the evaluator, controlled by two groups: Intervention Group (Telerehabilitation Program) and Control Group (Remote Follow-up). Caregivers in both groups received information in a standardized manner about dementia and COVID-19 care at baseline. For the Intervention Group, this information was more detailed and after these presentations, the Intervention Group received the Telerehabilitation Program, with standardized exercise for the older adults and guidelines for the caregiver. There were two online assessments: initial and after 12 weeks. The initial assessment was intended to measure mental health status (cognition and behavior) and functional capacity. In addition, mental health status, quality of life, and caregiver burden were assessed. After 12 weeks, caregiver satisfaction to the intervention and to Remote Monitoring in the older adults was verified using an online questionnaire. For the analyses, a significance level of α = 0.05 was adopted and SPSS (20.0) software was used to perform the statistical tests. For the open-ended questions, the procedure of qualitative data treatment and analysis was adopted, using the MAXQDA2022 software. After coding, for the obtained segments, Bardin's content analysis technique was performed. The total final sample after 12 weeks comprised 64 pairs of family caregivers and older persons. Caregivers in the Telerehabilitation Program showed higher satisfaction with the intervention, with the Internet treatment, and with the health care received than caregivers submitted to the Remote Follow-up. Both groups reported that they liked the treatment, pointed out the audio and video quality as excellent, and signaled a preference for Internet treatment over face-to-face. In the Intervention Group, only the hours dedicated to care influenced the satisfaction with the intervention. In the Control Group, the performance in cognition and functionality of the older person influenced satisfaction with the Remote Follow-up. More caregivers in the Intervention Group had their expectations reached, compared to the Control Group, although both groups reported difficulties throughout the 12 weeks and suggestions to the treatment. We conclude that the telerehabilitation program achieved satisfactory results, suggesting the potential of telerehabilitation as an aid in providing care for the older person with dementia and their caregivers.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Das "Jornadas" ao "Fora Dilma": uma explicação pelas classes
    (Universidade Federal de São Carlos, 2023-02-27)
    Ramatís, André
    ;
    Casalecchi, Gabriel Avila
    ;
    https://lattes.cnpq.br/9759794253878555
    ;
    https://orcid.org/0000-0003-1637-0180
    ;
    https://lattes.cnpq.br/3023679717033384
    The objective of this course conclusion work is to understand the movements that inspired the “June days” of 2013, specifically analyzing the composition of the corpus of manifestations, dividing the event into two periods and with two interpretation methodologies, namely: the analysis class Marxist; and the interpretation of the respondents' public opinions, via survey. What can be seen is a shift from young people just entering the world working to the streets, questioning public services, the political class and with the “centrality” of the urban mobility agenda, to, later, an older profile with the background of claims focused on the moralization of the political debate, anti-partisanship and anti-petism, their income index, as well as their space in production configure them as members of the middle class motivated, we believe, by a certain “social selfishness”. The investigation permeates the scope of this change, which is extranatural, the greatest time of mass demonstrations since redemocratization, mobilizing class characteristics exposed by the protesters' agency, in the same sense as in their reactions to the questions. Finally, we launch hypotheses for a deeper understanding of the theme related to the events of Lulism, indispensable for the cut, in an attempt to allocate the event to its historical period, being a “live” moment of the Brazilian class struggle.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Efeitos da fase do ciclo menstrual na massa muscular
    (Universidade Federal de São Carlos, 2023-02-27)
    Dias, Nathalia Fernanda
    ;
    Libardi, Cleiton Augusto
    ;
    https://lattes.cnpq.br/8953409094842074
    ;
    https://lattes.cnpq.br/6901117134684357
    Introduction: Eumenorrheic women are naturally exposed to hormonal fluctuations of estradiol (E2), progesterone (P4), luteinizing hormone, and follicle-stimulating hormone during the menstrual cycle (MC). However, these hormonal oscillations during MC in muscle mass are little known. The aim of the study was to investigate the possible changes in the muscle thickness (MT) and muscular cross-sectional area (MCSA) of the vastus lateralis, during the phases of two CM. As a secondary objective, we sought to investigate changes in muscle parameters throughout the CM, from an individual approach. Methods: Thirty-five healthy young women aged between 18 and 35 years and with a regular MC of 21 to 35 days participated in the study. Muscle evaluations by ultrasound and evaluations of E2 and P4 hormones by salivary samples were performed in the phases of the MC (follicular phase [FOL], ovulatory phase [OVU], and luteal phase [LUT]), for two consecutive cycles. A mixed-model analysis was performed to compare E2 and P4 levels, MT, and MCSA in different phases of MC. In case of significant F, Tukey's adjustment was performed for multiple comparisons. Additionally, a subsample (n=13) was analyzed, including only those participants who met the criteria of increased E2 in OVU in relation to FOL. In this subsample, the same mixed model analysis was performed, as well as a Person correlation analysis between all muscle and hormonal parameters investigated in each of the MC phases. Finally, from an individual analysis, we analyzed how many participants had true changes in MT and MCSA between MC phases. Results: P4 concentrations were significantly higher in first cycle LUT and second cycle LUT compared to first cycle FOL (p = 0.017 and p = 0.039, respectively), first cycle OVU (p = 0.0008 and p = 0.008, respectively), second cycle FOL (p = 0.012 and p = 0.0007, respectively) and second cycle OVU (p = 0.008 and p = 0.006, respectively). However, no significant differences were observed between the phases of the two MC for E2 concentrations. MT and MCSA also did not vary over the cycles. When analyzing a subsample, E2 concentrations were significantly higher in OVU than in FOL (p = 0.001), and P4 concentrations were significantly higher in LUT than in FOL (p = 0.017) and OVU (p = 0.0009). As observed in the complete sample, MT and MCSA were also unchanged. No significant correlation was observed between the muscular and hormonal parameters analyzed either. Finally, regarding the individual analyses, we observed that MT and MCSA showed changes for some participants over the MC. Conclusion: Hormonal variations resulting from the MC do not affect MT and the MCSA. However, changes in this tissue can be observed at the individual level in the different phases of MC, but without associations with the hormones E2 and P4.
  • Loading...
    Thumbnail Image
    Item type:Item,
    “O que se faz, como se faz, por que se faz?” – focalizando o núcleo da terapia ocupacional no campo da saúde mental infantojuvenil
    (Universidade Federal de São Carlos, 2023-02-27)
    Táparo, Flávia Arantes
    ;
    Cid, Maria Fernanda Barboza
    ;
    https://lattes.cnpq.br/8595043315867424
    ;
    https://lattes.cnpq.br/1822757843870161
    The field of child and youth mental health is understood as a multidisciplinary field, where different professional cores, including Occupational Therapy, interrelate, supporting each other in the fulfillment of theoretical and practical activities within this field. The available literature incipiently identifies the elements that characterize the professional core of Occupational Therapy in the field of child and adolescent mental health, pointing to the importance of deepening the knowledge in this theme. Thus, the present study had the general objective of identifying the perspective of occupational therapists involved in the psychosocial care of children and adolescents about the professional core of Occupational Therapy in the field of child and adolescent mental health. As specific objectives, the study sought to: identify aspects that support and/or influence the practices of occupational therapists in the field of mental health of children and adolescents; and analyze how other professionals involved in the psychosocial care of children and adolescents describe and evaluate the practice of occupational therapists in the field of child and adolescent mental health. An exploratory-descriptive study was carried out, with a qualitative and quantitative approach, in two phases. In Phase 1, 107 professionals participated, of which 59 were occupational therapists and 48 non-occupational therapists, who answered an online questionnaire. The questionnaire began with multiple-choice questions related to the sociodemographic aspects of the participants, followed by open questions about aspects and elements perceived about the core of Occupational Therapy in the field of child and youth mental health. In Phase 2 had the participation of 32 professionals who had participated in the first phase, of which 20 were occupational therapists and 12 non-occupational therapists. In this phase, four online focus groups were performed, two with each group of participants. The focus groups aimed to deepen the discussion about the professional core of Occupational Therapy in the field of child and adolescent mental health. The results of the sociodemographic evaluation, obtained with the questionnaire, were analyzed using descriptive statistics, while the data obtained in the open questions of the questionnaire and in the focal groups were analyzed using the Iramuteq® software. The results obtained with the sociodemographic questions of the questionnaire indicated a majority participation of cisgender women, occupational therapists and residents of the State of São Paulo. Among the non-occupational therapist participants, the participation of psychologists, nurses and social workers, respectively, stood out. Most of the participants were post graduated professionals and had previous experience working in Centers for Psychosocial Care (CAPS) for children and adolescents. The analysis of the results of the open questions of the questionnaire and of the focal groups, allowed answering the questions that appear in the title of this research. Regarding the question of what Occupational Therapy does and how it does in the field of child and adolescent mental health, the following were found: 1) the focus on occupations and on daily life activities; 2) the acting on routines and based on the daily lives of individuals; 3) the integral perspective on the subjects; 4) the weave of networks and intersectionality; 5) the acting on interface with the field of Education; 6) the acting in situations of intense psychic suffering and handling crisis situations; 7) the acting on situations of vulnerabilities and violence; and 8) the acting in the most serious and complex cases. As for why Occupational Therapy works in this way in this field , the results showed an approximation between the core of Occupational Therapy and the premises of psychosocial care of children and adolescents, which support the field of child and adolescent mental health, in the following aspects: 1) the importance of welcoming and listening; 2) valuing identities and subjectivities; 3) “doing together” what makes sense; 4) the expansion of autonomy and social participation; and 5) construction of life projects. The approximations between the core of Occupational Therapy and the field of child and adolescent mental health are the result of similar historical processes that this core and this field have gone through in the context of the Psychiatric Reform (especially Brazilian). They translate the unison and current theoretical understandings of both field and core in defense of childhoods and adolescences, of the care in a network setting and in freedom, the preservation of autonomy and citizenship and the appreciation of this population as active subjects and protagonists of their own history. It makes evident the importance and potency of the Occupational Therapy core in the field of child and youth mental health.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Protocolo mobility intensive training (Mob-IT) em crianças e adolescentes com paralisia cerebral: viabilidade de implementação e fidelidade do tratamento
    (Universidade Federal de São Carlos, 2023-02-27)
    Gonçalves, Luana Pereira Oliveira
    ;
    Pereira, Natalia Duarte
    ;
    https://lattes.cnpq.br/3408152349657748
    ;
    Campos, Ana Carolina de
    ;
    https://lattes.cnpq.br/5292093208120940
    Although intensive interventions have shown high levels of evidence in children and adolescents with cerebral palsy (CP), intervention protocols focusing on mobility are still limited. Still, the available studies often provide scarce information about the implementation of the intervention, which limits its reproducibility. Thus, two studies were carried out to describe the fidelity and feasibility of implementing an intensive protocol based on the principles of task-oriented therapy with a focus on mobility in children and adolescents with CP. The intervention was delivered using a single-subject experimental design. Four children with CP, median age: 11 years (where the youngest participant is 7 and the oldest is 13) levels I to III in the gross motor function classification system (GMFCS) participated. The mobility intensive training (Mob-IT) protocol proposed 24 hours of activities based on pre-established goals in collaboration with the participants, and was applied 3 times a week, in 2-hour sessions, for four weeks. Study 1 tested the fidelity of Mob-IT, and a manual of procedures was prepared to guarantee the fidelity of the protocol, which was tested in relation to the type of feedback provided, the level of difficulty, progression of tasks and the actual volume of the intervention. The results showed that the sessions ensured the use of extrinsically focused feedback (recommended), that the tasks were at least somewhat difficult, that task progression was performed during the intervention, and an average of 78% of the time was spent with the activities (actual volume), and 22% used as rest time and guidance. Study 2 aimed to verify the feasibility of Mob-IT with the aid of the Qualitative Feedback Questionnaire (QFQ) instrument, through adherence, acceptability, adverse effects, understanding of tasks and intervention time, and evaluating through the Canadian Performance Measure Occupational (COPM) the satisfaction of the participants and their guardians with the protocol. The results showed good acceptability of the protocol, few adverse effects, good understanding, and enough time, as reported by the participants. Regarding satisfaction, both participants and guardians were satisfied with the results of the training. Both studies had favorable results, with the implementation of the protocol being viable and faithful to the training principles and criteria. Thus, the effectiveness of the Mob-IT protocol will be tested in larger scale studies.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Secagem convectiva de concentrado de minério de ferro: abordagem experimental e simulações por fluidodinâmica computacional
    (Universidade Federal de São Carlos, 2023-02-27)
    Souza, Amarílis Severino e
    ;
    Béttega, Rodrigo
    ;
    https://lattes.cnpq.br/1379682125857376
    ;
    https://lattes.cnpq.br/3433503573566379
    Conventional transfer chutes are equipment used to change the solids flow direction in transporting systems that use conveyor belts. During operation, the solid transported by the upper conveyor belt enters the chute and falls, from where it is directed to the lower conveyor belt, changing its flow direction. A patent from Vale S.A company describes the adaptation of the transfer chute as an industrial drying unit, consisting of feeding hot air in the base of the equipment, which rises and exchanges heat and mass with the falling wet ore. One of the main advantages of the adapted equipment is the implementation of a moisture reduction process for iron ore concentrates in an equipment already installed on the production line. However, since it is a new technology, many aspects of its operation are unknown. The objective of this work was to simulate by computational fluid dynamics (CFD) the operation of the drying chute, referring to a unit installed in the pelletizing plant of São Luís/MA, analyzing and evaluating the momentum, heat, and mass transport phenomena involved. It was decided to experimentally obtain a correlation for the mass transfer coefficient (K), which is a key simulating parameter to be implemented in the CFD simulations for greater precision in describing the iron ore drying rate. The procedure for obtaining and validating the correlation for K was initially executed in a laboratory-scale dryer called FB-2. Thin layer drying experiments were carried out for various conditions of air temperature (50 °C ≤ Tf ≤ 90 °C) and air velocity (2.5 m/s ≤ uf ≤ 4.5 m/s). From these data, a correlation for K was obtained and implemented in CFD simulations of the FB-2 equipment. The validation procedure showed an excellent agreement between the experimental and simulated data for the variation of the dimensionless moisture with time. Afterwards, in order to obtain a correlation for a range of conditions closer to those of the drying chute, a new dryer (GR-1) was designed and constructed. In this dryer, for an air temperature of 140 °C and an air velocity of 15 m/s, a drying time of about 6 s was required to reduce the iron ore moisture by two percentage points (wet basis). From experimental data collected in the GR-1, a correlation for K was obtained for another range of air temperatures (100 °C ≤ Tf ≤ 140 °C) and air velocities (5 m/s ≤ uf ≤ 15 m/s), implemented in CFD simulations of the GR-1 equipment and validated against the experimental data. Finally, CFD simulations of the drying chute equipment were performed using the correlation for K previously obtained in the GR-1. The CFD simulations of the drying chute involved a porous zone model to describe the sieve that composes the equipment. Physical coherence of the model was investigated and considered appropriate. The contours of velocity, temperature and humidity of both the fluid and solid phases were presented, as well as the regions in which the drying rate was higher. In addition, the impacts of closing some outlets of the equipment was evaluated using the simulator. Numerical results provided a better understanding of the operation in the drying chute and the simulator showed potential to evaluate possible improvements in its geometry and operation.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Educação Antropofágica: apropriação cultural indígena pelos jesuítas no início da colonização portuguesa do Brasil (1549-1599)
    (Universidade Federal de São Carlos, 2023-02-27)
    Andrade, Leandro Lente de
    ;
    Bittar, Marisa
    ;
    https://lattes.cnpq.br/3059723520472948
    ;
    https://lattes.cnpq.br/6917189940573959
    This thesis aimed to understand indigenous cultural appropriation as a fundamental part of the pedagogical-catechetical pragmatism of the Society of Jesus in the first decades of their missions in Brazil. For this task, the following were explored: the reasons that led to the formation of the Catholic Order to have a high degree of adaptation to various historical conjunctures; the European interpretation of indigenous cultures; and the unyielding defenses of the indigenous soul and the viability of conversion despite the insistent behaviors condemnable by the Church. Primary historical sources, especially the Jesuit letters, and a wide specialized bibliography on the subject were used as a contribution to carry out this research. As a result of this survey, the central argument of the thesis consisted in listing a series of practices of appropriation and re-signification, promoting a specific meaning for each event of Christianization through education and not, in fact, incorporating such achievements as an official permanent strategy in the Jesuit legacy for Catholicism, even though accommodation is frequent in several other contexts. Therefore, such an approach did not lessen the relation of the Jesuits and indigenous peoples concerning acculturation, or Jesuit apologetics, or cultural hybridity – without considering the resistance of the original peoples and the pragmatic reason for this ephemeral cultural miscegenation. Finally, it was concluded that indigenous cultures, especially their arts, played a fundamental role in resisting European impositions, so that the appropriation of these cultural elements was the main way in which the Jesuits found a rapprochement with the original peoples. In this way, the performance of the Society of Jesus on the Brazilian coast during the 16th century used non-traditional methods, and sometimes too sensitive in the eyes of other important members of the Catholic Church, so that the process of catechization reached its much desired results.
  • Loading...
    Thumbnail Image
    Item type:Item,
    Estudo do efeito dos tratamentos duplex de nitrocementação e deposição de filmes DLC dopados com nitrogênio e silício nas propriedades tribológicas do aço M2
    (Universidade Federal de São Carlos, 2023-02-27)
    Danelon, Miguel Rubira
    ;
    Martins, Paulo Sérgio
    ;
    https://lattes.cnpq.br/6979394011332346
    ;
    https://orcid.org/0000-0002-8239-7528
    ;
    Rossino, Luciana Sgarbi
    DLC films have been the focus of recent research due to chemical inertia, low friction coefficient, high hardness, and interesting optical properties. But due to its problem of poor adhesion on metallic substrates, some alternatives have been developed to solve that problem, for example, the doping of DLC films like N and Si, and duplex treatments together with DLC film. Ionic plasma nitrocarburizing is a thermochemical treatment that improves the wear, fatigue, and corrosion properties, due to an iron nitride and carbonitrides formed on the surface and the nitrogen and the formation of a diffusion zone due to the carbon diffusion on the material. This work aims to study the effect of duplex treatment (nitrocarburizing+DLC) of silicon-doped and nitrogen-doped DLC on the wear resistance of AISI M2 in comparison with nitriding, nitrocarburizing, DLC, DLCN, and DLC-Si treated individually tribological behavior. Plasma treatments were carried out using a pulsed-DC power supply. Treatments were initialized, it was performed a plasma ablation cleaning with a gas mixture of 80%Ar-20%H2 for 1h. After the ablation treatments, plasma nitrocarburizing was performed with a gas mixture of 80%N2-15%H2-5%CH4 at 450ºC, a gas flow of 750sccm for 6h. By means of comparison, a nitriding treatment was performed under the same conditions but with a gas mixture of 80%N2-20%H2. DLC, DLCN, and DLC-Si films were deposited with a gas mixture of 90%CH4-10%Ar, 70%CH4-30%N2, and 90%CH4-8%Ar-2%HMDSO respectively, with a gas flow of 30sccm. All films were deposited for 2h. Duplex treatments were a combination of nitrocarburizing and DLC films with different doping. Duplex treatment with DLC-Si film was deposited in milling tools, to evaluate the effect of the treatment during the milling of aluminum alloy. Nitrocarburizing has presented a compound layer with thinner thickness when compared to nitriding treatment. So as the silicon and nitrogen-doped DLC films presented lower thickness in relation to conventional DLC film. Duplex treatments have shown a reduction of the compound layer and the DLC films when compared to simple treatments. Nitrocarburizing treatment has also presented a harder compound layer when compared to nitriding layer, due to the presence of the carbon element during treatment. DLC-Si film has shown the higher hardness among the DLC and DLCN treatments, due to the stabilization of sp3 hybridizations. While, the duplex treatments, has shown the highest hardness when compared to simple treatments, proving the efficiency of these treatments when compared to the simple ones. Duplex treatment of nitrocarburizing and DLC film doped with silicon presented the best wear resistance compared to other treatments, due to the stabilization of sp3 bonds in the film, which brings the film more hardness and thermal stability, the improve it is also due to the synergy between the compound layer and the DLC-Si film, which improves the wear resistance of the material, and, improves the adhesion of the film on the substrate. When milling aluminum, the treatment reduced the build-up edge formation without reducing the roughness of the milled sample. Thus, it is possible to conclude that the duplex treatment with nitrocarburizing and DLC film doped with silicon has presented the best performance during wear tests and has created the possibility of improving the useful life of AISI M2 milling tools.
  • «
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • ...
  • 317
  • »
Siga as redes sociais do SIBi
Contato

Repositório Institucional da UFSCar (RI UFSCar)

Av. Biblioteca Comunitária, Campus São Carlos

Rod. Washington Luís, km 235 - SP-310

São Carlos, SP, 13565-905 (16) 3351-8477

Email: repositorio@ufscar.br

Acessos ao repositorio.ufscar.br
Consultar estatísticas de acesso

DSpace software copyright © 2002-2026 LYRASIS

  • Accessibility settings
  • Privacy policy
  • End User Agreement