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Evaluation of the microstructure and micromechanics properties of structural mortars with addition of iron ore tailings.
No full textThe Interfacial Transition Zone (ITZ) between the cement paste and aggregates is a region of great
interest for concretes because it is the composites’ weakest region. ITZ presents a great amount of
large calcium hydroxide and ettringite crystals, with the porosity being able to be up to 2.5
greater than that the rest of the paste. The microstructure, and consequently the ITZ, can be
improved by mineral addition. These materials fill the pores in the composite, influence the
hydration process and densify the matrix. Therefore, mineral additions, such as iron ore tailings
(IOT), can modify microstructure of composites. There are few studies on the assessment of IOT
heterogeneity on the microstructure and hardness of structural mortar. Thus, the present study
analyzes the properties influences of four IOT types on the microstructure, porosity, and thickness
of the structural mortars’ Interfacial Transition Zone (ITZ) with IOT addition, by different evaluation methods. The composites were characterized through the Scanning Electron Microscope by
backscattered electrons (SEM-BSE), line scan by Energy Dispersive Spectroscopy and nanoindentation. Results presented that IOT improved particle packing and tended to reduce the ITZ.
The IOT improved nucleation since it reduces the amount of anhydrous cement particles and
increases the amount of calcium hydroxide particles in the cement matrix. The nanoindentation
showed that IOT-added matrix presented greater hardness and indentation module. It can be
concluded that the IOT heterogeneity may affect microstructural properties and that the methods
presented can be good ways to evaluate the parameters
Gestão do conhecimento como estratégia para a sustentabilidade de uma incubadora tecnológica de cooperativas populares.
No full textPrograma de Pós-Graduação em Engenharia de Produção. Departamento de Engenharia de Produção, Instituto de Ciências Exatas e Aplicadas, Universidade Federal de Ouro Preto.O conhecimento possibilita às organizações a definição de estratégias em busca de sua
sobrevivência. Buscando ações que visem a sustentabilidade, as organizações, bem
como incubadoras tecnológicas de cooperativas populares (ITCPs), precisam definir
estratégias para propiciar o aperfeiçoamento e a incorporação do conhecimento à cultura
organizacional. As ITCPs inseridas no contexto de instituições de ensino superior
(IESs), são vistas como uma forma de aplicação da extensão universitária que combina
esforços individuais no intuito de alcançar propósitos coletivos. Assim, possuir a gestão
do conhecimento (GC) como uma estratégia organizacional pode possibilitar que a
ITCP saiba lidar com seus conhecimentos para alcançar seus objetivos internos e
aqueles vinculados às ações de assessoria. Desse modo, esta pesquisa teve como intuito
propor possíveis estratégias de GC que visem a sustentabilidade das ações de uma
ITCP. Para tanto, foi realizado um estudo de caso, baseado nas experiências de uma
ITCP, definida na instituição a qual está inserida, como um laboratório de extensão.
Foram utilizadas como técnicas de coleta de dados: observação participante; entrevistas
semiestruturadas com membros da ITCP, guiadas por roteiro; e análise documental a
partir de registros disponibilizados pela ITCP. Buscou-se, por meio deste trabalho,
compreender a metodologia de trabalho da ITCP e as relações que ela estabelecia, assim
como identificar processos de conhecimento e práticas de GC existentes na incubadora e
associadas a esses processos. Foi analisada a sustentabilidade da ITCP considerando as
dimensões econômica, política, social, de gestão e de formação, o que possibilitou a
identificação de problemas de conhecimento que poderiam ser obstáculos no
desenvolvimento das ações da ITCP e propensos a impactar a sustentabilidade da
incubadora, além de atingir aqueles apoiados por ela. Assim, entendendo esses
problemas, foram sugeridas ações voltadas ao conhecimento considerando o contexto da
ITCP estudada e as estratégias existentes. Por fim, foi proposto um framework de GC
adaptado da teoria que visou incluir aspectos considerados relevantes pelos membros da
incubadora, que foram expostos nas entrevistas, unindo a essa construção as reflexões
estabelecidas quanto ao conhecimento e à sustentabilidade. Ademais, este estudo teve
por intuito contribuir com a teoria de GC relacionando a estrutura organizacional de
uma ITCP, sua sustentabilidade e os preceitos da filosofia que embasam suas ações,
com os conhecimentos existentes e desafios a serem enfrentados quanto ao
conhecimento e a continuidade de suas ações.Knowledge enables organizations to define strategies in search of their survival.
Seeking actions aimed at sustainability, organizations, as well as technology incubators
of popular cooperatives (TIPCs), need to define strategies to promote the improvement
and incorporation of knowledge into the organizational culture. The TIPCs inserted in
the context of higher education institutions (HEIs) are seen as a way of applying
university extension that combines individual efforts in order to achieve collective
purposes. Thus, having knowledge management (KM) as an organizational strategy can
enable TIPC to know how to deal with its knowledge to achieve its internal objectives
and those linked to advisory actions. Thus, this research aimed to propose possible KM
strategies aimed at the sustainability of the actions of an TIPC. For that, a case study
was carried out, based on the experiences of an TIPC, defined in the institution in which
it operates, as an extension laboratory. The following data collection techniques were
used: participant observation; semi-structured interviews with TIPC members, guided
by a script; and document analysis based on records made available by TIPC. This work
sought to understand TIPCs work methodology and the relationships it established, as
well as to identify knowledge processes and KM practices existing in the incubator and
associated with these processes. TIPC’s sustainability was analyzed considering the
economic, political, social, management and training dimensions, which made it
possible to identify knowledge problems that could be obstacles in the development of
TIPC actions and likely to impact the sustainability of the incubator, in addition to to
reach those supported by it. Thus, understanding these problems, actions aimed at
knowledge were suggested considering the context of the TIPC studied and the existing
strategies. Finally, a KM framework adapted from the theory was proposed, which
aimed to include aspects considered relevant by the incubator members, which were
exposed in the interviews, joining this construction with the established reflections
regarding knowledge and sustainability. Furthermore, this study aimed to contribute to
the theory of KM by relating the organizational structure of an TIPC, its sustainability
and the precepts of the philosophy that underlie its actions, with the existing knowledge
and challenges to be faced regarding the knowledge and continuity of its actions
Diversity patterns of host plants and their gall‐inducing insects in the Brazilian Cerrado : testing ecological and historical hypotheses.
No full textCerrado is one of the most diverse savannahs on the planet in terms of plant species and insect herbivores, as well as in hotspot in the diversity of plant–galling insect interactions. The aims of the study were as follows: characterize the diversity of host plants (HP) and their associated gall-inducing insects (GII) in the Brazilian Cerrado; estimate the species richness of GII for the Cerrado vegetation; determine if GII species richness is shaping the plant species richness, taxa size, and the taxon age; to analyze the number of species per HP communities, and estimate the number of GII (co-threatened) in endangered plants. We used a comprehensive database compiling information available in 32 inventories on GII and their HP from several areas of the Cerrado. We fnd 994 morphospecies associated with 505 HP. Additionally, we estimated a total of 11,745 GII for the Cerrado, of which 8,574 were cecidomyiid species. More than 58% of the HP harbored a single GII, while 42% had more than two GII, corroborating the high specialization of the GII on their HP. Finally, we detected nine threatened HP hosting 27 species of GII, which are considered super-hosts. Our study is the frst to analyze the assemblages of HP and their GII in the Cerrado vegetation at a regional scale. Our fndings indicate a high regional diversity of both HP and GII, and we highlight the importance of plant species richness, taxon size, and the taxon age as factors shaping the diversity of GII in the Cerrado
Petrographic characterization through the study of the mineralogy and textural aspectos of kimberlites from the Alto Paranaíba Igneous Province - PIAP, Minas Gerais.
No full textOs kimberlitos são rochas ígneas, potássicas e ultrabásicas derivadas de magmas ricos em voláteis que, durante sua rápida ascensão, incorporam e assimilam materiais de diferentes origens, incluindo o diamante. Um dos desafios, principalmente em lâminas delgadas, é a separação de minerais de origem crustal, mantélica e genuína do próprio magma kimberlítico. A formação de estruturas específicas decorrentes desta subida e colocação na litosfera contribui para a complexidade do seu estudo, juntamente à suscetibilidade à alteração. A fase de descrição petrográfica realizada de forma sistemática é crucial para as etapas posteriores de investigações geoquímicas e, consequentemente, para estudos de preservação e distribuição de diamantes. Existe uma expressiva lacuna na classificação das rochas kimberlíticas da Província Ígnea do Alto Paranaíba (PIAP), que embora tenham sido estudadas ao longo dos anos com enfoque na geoquímica e descrições de xenólitos mantélicos, carecem de estudos pormenorizados da mineralogia e categorização sistemática dos clastos sob a ótica das classificações atuais. As abordagens aplicadas até o momento são as mesmas para a maior parte das rochas ígneas, e esses parâmetros são insuficientes para a descrição de componentes tão incomuns que ocorrem apenas nas rochas kimberlíticas. Através da descrição petrográfica de kimberlitos da PIAP utilizando uma abordagem recente e sistemática, juntamente com registros fotográficos dos principais componentes presentes, será possível estabelecer uma relação entre essas rochas e as zonas as quais pertencem. A criação deste indispensável elo irá contribuir no entendimento dos aspectos petrológicos da região mantélica local e nas futuras interpretações genéticas dessas ocorrências, permitindo reconstruir a história de colocação desses corpos na crosta e futuros modelos geológicos válidos para a estimativa de recursos.Kimberlites are igneous, potassic and ultrabasic rocks derived from volatile-rich magmas that, during their rapid ascent, incorporate and assimilate materials of different origins, including diamond. One of the challenges, especially in thin sheets, is the separation of minerals of crustal, mantle and genuine origin from the kimberlitic magma itself. The formation of specific structures arising from this ascent and emplacement in the lithosphere contributes to the complexity of its study, along with susceptibility to alteration. The petrographic description phase carried out in a systematic way is crucial for the later stages of geochemical investigations and, consequently, for diamond preservation and distribution studies. There is a significant gap in the classification of kimberolitic rocks of the Upper Paranaíba Igneous Province (PIAP), which, although they have been studied over the years with a focus on geochemistry and descriptions of mantle xenoliths, lack detailed studies of mineralogy and systematic categorization of clasts under the view of current classifications. The approaches applied so far are the same for most igneous rocks, and these parameters are insufficient for the description of such unusual components that occur only in kimberolitic rocks. Through petrographic description of kimberlites from the PIAP using a recent and systematic approach, together with photographic records of the main components present, it will be possible to establish a relationship between these rocks and the zones to which they belong. The creation of this indispensable link will contribute to the understanding of petrological aspects of the local mantle region and to future genetic interpretations of these occurrences, allowing the reconstruction of the emplacement history of these bodies in the crust and future valid geological models for resource estimation
Real-time capacitive sensor applied to a train wagon prototype for measuring iron ore moistur.
No full textAbstract—The emission of particulates during rail transport is related to the low moisture of the ore, which causes environmental pollution along the railroad. Given this problem, this work proposes the development of a parallel plate capacitive sensor applied to a small wagon prototype made of acrylic to measure the iron ore moisture and support studies of particulate emissions carried out in a laboratory. The sensor uses the Real-Dual Frequency method, which decreases the influence of electrical conductivity on the dielectric constant, even using low frequency (up to 8 MHz). From the dielectric constant, iron ore moisture is determined from indirect calibration, which obtained an accuracy of 0.07 pp and a maximum error of 0.39 pp. This study shows the development of an innovative real-time capacitive sensor, which uses a modern impedance-based technique to investigate particulate emissions and the drying behavior of iron ore
Evaluation of the activity and selectivity of mesoporous composites of MCM-41 and CuO in the CO2 photoreduction process.
No full textThe conversion of CO2 into valuable chemical feedstock through photocatalysis is considered an effective
strategy to mitigate global warming and energy supply problems. Among the challenges for CO2 photoreduction
are the design and synthesis of active photocatalysts with high affinity for the CO2 molecule and suitable
reduction potentials of valence and conduction bands to promote the reduction of the CO2 molecule. Molecular
sieves (MCM-41) with semiconductors, such as copper oxide, are alternatives to the traditional semiconductors
(TiO2 and ZnO) with high CO2 adsorption capacity, high specific surface area, and good stability, making them
perfect candidates for photocatalysis. Therefore, in this work, mesoporous composite materials based on MCM-41
and CuO were synthesized via the impregnation method. The synthesized materials were chemically, structurally, and morphologically characterized by XRD, SEM, FTIR, XPS, DRS, N2 adsorption and desorption, and atomic
absorption spectroscopy techniques, and the photocatalytic activity in the reduction of CO2 was evaluated under
visible radiation. We show that MCM-41 and the composite MCM-41/CuO have significant potential for use in
the CO2 photoreduction process, where the composition and different active sites in the photocatalysts play an
important role in the activity and selectivity of the products formed. The results showed that the MCM-41 and the
composite with 1 % (w/w%) CuO presented high selectivity and production of methanol, with 585.88 and
267.05 μmol.gcatalyst
-1 , respectively. Thus, the findings demonstrated the versatility of the MCM-41 to form
composites with semiconductors, as well as the need to comprehend the main aspects that influence CO2
photoreduction activities and the selectivity of the composites, including their surface, structural, and electrical
features
Research progress, trends, and future prospects on hydrothermal liquefaction of algae for biocrude production : a bibliometric analysis.
No full textThe rising demand to settle a sustainable energy source is guiding researchers in the production of biofuels. The liquefaction
process is an alternative to obtaining biocrude from diferent types of renewable biomass and can mitigate environmental
impacts. All papers published since 2000, which are related to the hydrothermal liquefaction process that aims to obtain
biocrude are analyzed in the present study using the bibliometric approach to provide the selected database. Furthermore, the
use of algae biomass in the liquefaction was also a discussed topic considering its high relevance in the process. The focus
of the present study was to evaluate the evolution of the current state of the art in these topics and also to indicate trends
and courses that it might be taken in the future. The database used in the bibliometric analysis was taken from the Web of
Science (WoS) and the papers were selected by two diferent search equations. With the selected data, the use of BibExcel,
VOSviewer, and PowerBi software was useful to guide the discussion and to create graphics and visual networks. As shown
in the results, it was noticeable the infuence of China and the USA on the feld, considering the high number of publications from these countries. Moreover, the main authors were indicated considering their citation numbers, publications,
and local h-index factor. Based on the author’s keywords, the most signifcant and recent topics on liquefaction were listed.
Among them, technical-economic analysis, nutrient, and energy recovery, response surface methodology, and kinetic model
are highlighted. This may indicate a new direction being taken by researchers besides the operational parameters’ studies
Tuberculosis incidence profile in municipalities of the state of Espírito Santo, Brazil, 2015-2020.
No full textA tuberculose é uma doença causada pelo Mycobacterium tuberculosis, transmitida, principalmente, pelo ar e pode
atingir vários órgãos do corpo. A confirmação é realizada a partir de análise do material da lesão, identificando o
bacilo de Koch. Trata-se de estudo transversal e descritivo que avaliou as taxas de incidência calculadas a partir
dos casos de tuberculose notificados, por meio do Sistema de Informação de Agravos de Notificação (SINAN),
entre os anos de 2015 e 2020 nos municípios do Estado do Espírito Santo. De acordo com o método descrito e data
da coleta de dados, foram observados 8.687 casos no recorte de tempo escolhido, dos quais 71,06% são do sexo
masculino. Analisando os possíveis agravantes como tabagismo e etilismo, notam-se altas taxas de incidência nos
municípios que compõem a Região Metropolitana de Vitória, quando comparados a outros municípios do Estado.
Os dados demonstraram que a faixa etária de maior incidência foi de 29 a 39 anos. O estudo, a partir dos seus
resultados, possui potencial para subsidiar discussões acerca do controle da doença no Estado, além da notificação.
Dessa forma, poderá ser utilizado auxiliando a gestão da saúde pública para otimizar os recursos e equipes para o
controle da tuberculose nos municípios que apresentarem incidências discrepantes ao que estava sendo proposto
em relação ao Plano Estadual de Controle da TB do Espírito Santo.Tuberculosis is a disease caused by Mycobacterium tuberculosis, transmitted mainly through the air and can affect
various organs of the body. Confirmation is performed by analyzing the lesion material, identifying Koch's
bacillus. Cross-sectional and descriptive study that evaluated the incidence rates calculated from the cases of
tuberculosis notified, through the Information System of Notifiable Diseases (SINAN), between the years 2015
and 2020 in the municipalities of the State of Espírito Santo. According to the method described, 8,686 cases were
observed in the chosen time frame, of which 71.06% are male. Analyzing possible aggravating factors such as
smoking and alcohol consumption high incidence rates are observed in the municipalities that make up the
Metropolitan Region of Vitória, when compared to other municipalities in the state. It was determined that the age
group with the highest incidence was 29 to 39 years old. The study, based on its results, has the potential to support
discussions about disease control in the State, in addition to notification. In this way, it can be used to help public
health management to optimize resources and teams for tuberculosis control in municipalities that present
discrepant incidences to what was being proposed in relation to the Espirito Santo State TB Control Plan
Avaliação do ensino remoto emergencial pelos docentes de pós-graduação da Universidade Federal de Goiás.
No full textA presente pesquisa tem como intuito investigar a opinião dos docentes que atuaram nos programas de pós-graduação da Universidade Federal de Goiás em 2020 acerca do trabalho desenvolvido por eles na modalidade de ensino remoto emergencial, durante o primeiro ano de Pandemia de Covid-19. Os dados obtidos por esta pesquisa foram originados a partir da avaliação realizada em novembro de 2020 pela Pró-Reitoria de Pós-Graduação da UFG que possuía como intuito analisar a situação do ensino remoto emergencial (ERE) e o seu impacto na pós-graduação. Após análise dos dados, constatou-se que apesar do ensino remoto ter demonstrado com clareza as desigualdades profundas existentes na educação brasileira, para o momento de isolamento social que vivemos o ERE se tornou uma opção aprovada pela maioria dos docentes investigados. Além disso, constatou-se que, em relação ao uso das Tecnologias Digitais de informação (TDICs), foi um momento de aumento pela demanda por cursos de capacitação para uso das novas tecnologias e que os docentes tiveram menos dificuldades com as ferramentas que eles já lidavam antes da pandemia
Resveratrol induces the production of reactive oxygen species, interferes with the cell cycle, and inhibits the cell migration of bladder tumour cells with different TP53 status.
No full textResveratrol is a polyphenolic compound whose antitumor activity
has been demonstrated in several types of cancer. However, there
are few studies on its molecular mechanisms of action in bladder
cancer. Therefore, we aimed to evaluate resveratrol activity in
bladder tumour cells with different TP53 gene status. Cytotoxicity,
cell proliferation, reactive oxygen species (ROS) production, cell
migration, mutagenicity, and CDH1, CTNNBIP1, HAT1, HDAC1, MYC,
and SMAD4 gene expression were evaluated. An increase in ROS
after resveratrol treatment was accompanied by reduced cell viability and proliferation in all cell lines. In TP53 wild-type cells, the
inhibition of cell migration was accompanied by CDH1 and
SMAD4 modulation. In TP53 mutated cells, cell migration inhibition with CDH1 and CTNNB1P1 upregulation was observed. In
conclusion, resveratrol has antiproliferative effect in bladder
tumour cells and its mechanism of action occurred through ROS
production, interference with cell cycle, and inhibition of cell
migration, independent of TP53 status