297 research outputs found
Efeito da adição de resÃduos de polietileno de alta densidade e borracha de pneus em ligante asfáltico 50/70
Dissertação apresentada ao Programa de Pós-
Graduação em Engenharia Civil da Universidade
Federal da Integração Latino-Americana, como
requisito parcial à obtenção do tÃtulo de Mestre
em Engenharia Civil. Orientador: Prof. Dr. Ricardo Oliveira de SouzaNo Brasil a pavimentação de ruas, avenidas e estradas são executadas maiormente com
misturas asfálticas, em que o ligante asfáltico tem papel fundamental na coesão,
resistência ao afundamento de trilha de roda, resistência à fadiga e resistência ao
trincamento térmico. O desempenho desses ligantes pode ser melhorado com a adição de
modificadores como estireno-butadieno-estireno (SBS), etileno acetato de vinilo (EVA),
resÃduo de polietileno e/ou de borracha de pneus reciclados. Neste sentido, este estudo
avaliou o efeito da adição de resÃduo de polietileno de alta densidade (PEAD) em teores
de 1, 2, 3% e de borracha de pneus reciclados em teores de 13 e 15% ao ligante asfáltico
convencional 50/70. A avaliação envolveu ligantes não envelhecidos e envelhecidos em
curto prazo, de modo que todos os ligantes foram submetidos a ensaios de ponto de
amolecimento, ponto de fulgor, viscosidade Brookfield, cisalhamento dinâmico, fluência
em viga, termogravimetria, calorimetria exploratória diferencial e espectroscopia de
infravermelho, e para todos os resultados foram realizadas análises de regressão linear
múltipla. Constatou-se a adição de PEAD e borracha de pneus agem como agentes
redutores de perda de massa, de modo a diminuir a volatilização do CAP modificado.
Para os maiores teores de adição de PEAD e menores teores de borracha, houve um
aumento da consistência e da resistência ao afundamento de trilha de roda. A adição de
13% de borracha + 3% de PEAD apresentou o melhor desempenho dentre os ligantes
modificados avaliados.In Brazil, asphalt mixtures are used for almost streets, avenues and highways paving
works. In this case, asphalt binder has a key role considering the cohesion, resistance do
rut depth, resistance to fatigue and to thermal cracking. Binder modifiers such styrene-
butadiene-styrene (SBS), ethylene-vinyl-acetate (EVA), Polyethylene and ground rubber
have been used to enhance the performance of unmodified asphalt binders. This study
evaluated the addition of High Density Polyethylene (HDPE) residue (1, 2, 3%) and ground
rubber from scrap tires (13 and 15%) to 50/70 (grade of penetration) asphalt binder. The
evaluation comprised unaged and short-term aged modified and unmodified asphalt
binders. Laboratory tests such the softening point, flash point, Brookfield viscosity,
dynamic shearing, creep stiffness, thermogravimetry and differential calorimetry were
carried out for all binders. Regression analyses were accomplished considering the
laboratory data results. It was found that modified binders using higher HDP addition rates
allied to lower ground rubber rates improved consistency and resistance to rut depth. The
addition of 13% ground rubber plus 3% HDPE proved the best performance amongst
modified binders evaluate
A non-randomized comparative study using different doses of acyclovir to prevent herpes simplex reactivation in patients submitted to autologous stem cell transplantation
The reactivation of Herpes Simplex virus (HSV) occurs in 70% to 80% of patients submitted to autologous stem cell transplantation (ASCT); it increases the severity of chemotherapy-induced mucositis. Therefore, the use of acyclovir in ASCT patients is considered standard practice. However, the minimum dose needed to prevent reactivation is a matter of debate. We compared two doses of acyclovir in a non-randomized fashion in 59 patients submitted to ASCT: 32 patients received a dose of 125 mg/m2 IV every six hours and the subsequent 27 patients received a dose of 60 mg/m2 IV every six hours. Viral excretion was evaluated through weekly viral culture of oral swabs. Grade 4 mucositis was more frequent in Group 1 (p= 0.03). The reactivation rates in Groups 1 and 2 were 9% and 4%, respectively (p= 0.62, 95% confidence interval -7 - 18). Prophylaxis with reduced doses of intravenous acyclovir seems to be as effective as a higher dose in inhibiting HSV reactivation, with a significant reduction in cost. Prospective randomized studies are needed to confirm our conclusions.
Mortalidade intra-hospitalar em pacientes submetidos a cirurgia em um hospital universitário no sul do Brasil : comparação entre duas coortes : antes e durante a pandemia covid-19
Introdução: A pandemia de COVID-19 influenciou drasticamente a prática médica no nosso paÃs. Alterações na dinâmica do funcionamento dos hospitais foram imprescindÃveis para reduzir a sobrecarga e para evitar o colapso do sistema de saúde. O presente estudo objetiva examinar se a pandemia impactou na mortalidade de pacientes cirúrgicos no perÃodo perioperatório até 30 dias em um hospital referência para o tratamento da COVID-19 no sul do Brasil. Métodos: Conduzimos um estudo de coorte utilizando dados de pacientes cirúrgicos que foram operados antes (janeiro de 2018 a dezembro de 2019) e durante a pandemia do novo coronavÃrus (fevereiro a dezembro de 2020). Três grupos de pacientes submetidos à cirurgia foram criados: Pré-pandemia (2018-2019), Durante Pandemia COVID-negativos e Durante Pandemia COVID-positivos (2020). Estimamos o risco clÃnico e cirúrgico e associações independentes entre a pandemia e mortalidade intra-hospitalar até 30 dias foram avaliadas utilizando o modelo de regressão de Poisson com variância robusta. Resultados: Foram incluÃdos 15.156 pacientes no estudo, sendo 12.207 pertencentes ao grupo pré-pandemia e 2.949 aos grupos de durante a pandemia. A mortalidade encontrada foi de 2,5% (309/12207) no grupo controle versus 7,2% (212/2949) no grupo operado durante a pandemia. A mortalidade entre pacientes diagnosticados com COVID durante ou após a cirurgia foi de 25,8% (32/124) ao passo que dentre os negativos para COVID foi de 6,4% (180/2816). A proporção de cirurgias urgentes, ASA ≥ 3 foi maior no grupo da pandemia. O risco relativo de ter sido submetido a cirurgia durante a pandemia, após ajustes para variáveis sabidamente relacionadas com mortalidade foi de 1,52 (IC 95% 1.27-1.84). Associações independentes foram encontradas entre mortalidade e categoria do modelo de risco Ex-Care, infecção por COVID e cirurgia torácica. Análise de sensibilidade excluindo pacientes infectados por COVID permaneceu mostrando aumento do risco cirúrgico no perÃodo da pandemia. [RR de 1.50 (95% IC 1.27-1.78)]. Resultados: A mortalidade perioperatória foi substancialmente aumentada dentre submetidos à cirurgia na pandemia, mesmo entre aqueles sem infecção por COVID. Dessa forma, nosso resultado sugere que a pandemia impactou negativamente na assistência à saúde. Esta pandemia sem precedentes reforça a necessidade de se adotarem estratégias que fortaleçam o sistema cirúrgico e promovam prosperidade econômica em paÃses de baixo e médio rendimentos, tal como o Brasil.Before the pandemic, healthcare systems in LMICs (low-middle income countries) already experienced limited 'capacity to rescue' and scaling up of care to prevent deaths in those patients who develop postoperative complications and physiological deterioration on hospital wards. It is still uncertain whether the pandemic itself and hospital delivery have played a role in raising postoperative mortality rates even further. This before and after cohort study aimed to assess the pandemic impact on postoperative mortality up to 30 days in a university, COVID-19 referral hospital, in Southern of Brazil. Methods: We conducted a cohort study using data from patients who operated before (from January 2018 to December 2019) and during the pandemic (from February to December 2020). Data describing the two groups were compared. The surgical and clinical risk were estimated, and the independent association of pandemic and in-hospital 30-day mortality were evaluated using Poisson regression with robust error variance analysis. Results: 15.156 patients were included, 12.207 operated before the pandemic and 2.949 operated during the first pandemic year. Mortality rates were 2,5% (309/12207) in the control group versus 7,2% (212/2949) in during pandemic group. Mortality among COVID-positive patients was 25,8% (32/124) and between COVID-negative patients was 6,4% (180/2816). The proportion of urgent surgeries, ASA ≥ 3 was higher in pandemic group. The relative risk of being operated during the pandemic, after adjustments for variables known to relate to mortality was 1,52 (1.27-1.84). Sensitivity analysis excluding COVID-positive patients showed the increase in mortality risk of being operated during pandemic [RR of 1.50 (95% CI 1.27-1.78)]. Conclusions: Postoperative mortality was substantially increased among patients submitted to surgery during the pandemic, even among those without COVID infection, and that suggests that the pandemic itself played a negative role in health surgical system. This episode in global health has reinforced the need to adopt strategies to strengthen surgical systems to save lives and promote economic growth in LMIC
Exploring Inclusive Design and Digital Humanities: Enabling Bilingual Digital Narratives for Deaf Children
The collaboration between designers and digital humanists has indeed gained increasing significance in crafting effective projects, with design serving as a centralizing force in the realm of digital humanities by establishing interfaces for individuals to engage with technological resources. Therefore, design's methodological practices, encompassing various research and experiential facets, play a pivotal role in enhancing the usability and accessibility of digital resources within the social sphere. This study aims to expand the discourse on the characteristics and potential of the interplay between inclusive design and digital humanities practices, with a specific focus on the development of bilingual digital narratives (utilizing Brazilian Sign Language and Portuguese). The research adopts a collaborative, qualitative approach, encompassing processes of evaluation, validation, and enhancement. Digital visual narratives are presented as a facilitating tool for integrating LIBRAS and Portuguese, thereby aiding in language acquisition for deaf children. The article contributes to the discussion of the humanistic approach to design, emphasizing the values of empathy, ethics, and social responsibility in the creation of inclusive and accessible projects
Successful surgical management of an extrahepatic biliary cystadenocarcinoma
Extrahepatic bile duct cancer is an uncommon disease, and few cases are curable by surgery. We report a case of extrahepatic biliary cystadenocarcinoma (BCAC) associated with atrophy of the left hepatic lobe. A 54-year old male was admitted with painless obstructive jaundice and a hepatic palpable mass noticed one month before presentation. Liver functions tests were consistent with cholestatic damage and serum carbohydrate antigen 19.9 (CA 19-9) was increased before treatment. Magnetic resonance imaging (MRI) disclosed dilatation of the left hepatic bile duct with irregular wall thickening close to the hepatic confluence, and atrophy of left hepatic lobe. The patient was submitted to en bloc extended left hepatectomy with resection of caudate lobe, hilar lymphadenectomy, and suprapancreatic biliary tree resection. All surgical margins were grossly negative, and postoperative course was uneventful, except for a minor bile leak. The patient was discharged on the 15th postoperative day; he is alive without tumor recurrence one year after primary therapy. Although technically challenging, extended en bloc resection is feasible in adults with extrahepatic BCAC and can improve survival with acceptable and manageable morbidity
New softwares for automated microsatellite marker development
Microsatellites are repeated small sequence motifs that are highly polymorphic and abundant in the genomes of eukaryotes. Often they are the molecular markers of choice. To aid the development of microsatellite markers we have developed a module that integrates a program for the detection of microsatellites (TROLL), with the sequence assembly and analysis software, the Staden Package. The module has easily adjustable parameters for microsatellite lengths and base pair quality control. Starting with large datasets of unassembled sequence data in the form of chromatograms and/or text data, it enables the creation of a compact database consisting of the processed and assembled microsatellite containing sequences. For the final phase of primer design, we developed a program that accepts the multi-sequence ‘experiment file’ format as input and produces a list of primer pairs for amplification of microsatellite markers. The program can take into account the quality values of consensus bases, improving success rate of primer pairs in PCR. The software is freely available and simple to install in both Windows and Unix-based operating systems. Here we demonstrate the software by developing primer pairs for 427 new candidate markers for peanut
RaciocÃnio moral em questões sociocientÃficas: argumentação de licenciandos de ciências sobre a eutanásia
The objective of this work was to identify the extent of argumentative skills and establish the possible presence of levels of moral reasoning in the arguments produced by science teachers in training regarding Euthanasia as a socioscientific issue (SSI). Socioscientific issues are characterized by controversial topics, generating discussions involving values, moral reasoning and decision-making. To carry out this research, we used the focus group as a method of data collection. The focus group proved to be adequate for this research, since we sought to analyze the statements that emerged during the discussion among the participants. To analyze the data, we used Toulmin's argumentative methodological approach to build the argumentative layouts of each survey participant. In a second moment, each of these layouts was analyzed according to Kohlberg's taxonomy of moral reasoning. As results we found that the science teachers in training were able to build arguments, and that the levels of moral reasoning show us that few people rely on laws to make up their moral reasoning in the process of decision-making on euthanasia.O objetivo desse trabalho foi identificar a extensão das habilidades argumentativas e estabelecer a possÃvel presença de nÃveis de raciocÃnio moral nos argumentos produzidos por professores de ciências em formação, a respeito da eutanásia como questão sociocientÃfica (QSC). As questões sociocientÃficas são caracterizadas por serem temas controversos, geradores de discussões que envolvem valores, raciocÃnio moral e tomada de decisão. Para a realização dessa proposta de trabalho, utilizamos o grupo focal como método de coleta de dados. O grupo focal se mostrou adequado para esta pesquisa, já que buscávamos analisar as falas que emergiam durante a discussão entre os participantes. Para análise dos dados, em um primeiro momento, utilizamos a abordagem metodológica argumentativa de Toulmin para construir os layouts argumentativos de cada participante da pesquisa. Em um segundo momento, cada um desses layouts foi analisado segundo a taxonomia de raciocÃnio moral de Kohlberg. Como resultados verificamos que, de maneira geral, os professores de ciências em formação são capazes de construir argumentos e que os nÃveis de raciocÃnio moral apresentados nos mostraram que poucas pessoas se baseiam em leis para construir seus raciocÃnios morais no processo de tomada de decisão a respeito da eutanásia
Câmara frigorifica com atmosfera controlada para conservação de produtos frutÃcolas refrigerados
Trabalho final de Mestrado para obtenção do grau de mestre em Engenharia Mecânica Ramo de Energia, Refrigeração e ClimatizaçãoO trabalho de projeto final de Mestrado, corresponde à conceção de uma câmara frigorÃfica com atmosfera controlada para conservação de produtos frutÃcolas refrigerados, em que o fruto escolhido foi o kiwi. Foi feito uma caracterização do fruto e principais propriedades e enquadramento da sub-fileira do kiwi em Portugal. Foram abordados os fatores de conceção da câmara frigorÃfica com atmosfera controlada e apresentadas as diferenças relativamente à atmosfera normal. Seguidamente foi apresentado a planta de instalação, que irá possuir3 câmaras frigorÃficas com atmosfera controlada, zona de lavagem, zona de calibragem e triagem, tanque de pré-arrefecimento, zona de embalamento, sala das máquinas, armazém e área administrativa. A parte mais técnica corresponde ao dimensionamento e conceção da instalação frigorÃfica e da câmara frigorÃfica de atmosfera controlada. No final identificou-se o impacte ambiental, análise financeira, pontos crÃticos e as mais-valias da solução.Abstract: The working end of Master design corresponds to thedesign of a cooling chamber with controlled atmosphere to refrigerated storage kiwi.It was made a characterization of fruit and main properties and environment of the kiwi sub-row in Portugal. The design factor of the refrigerator was approached of controlled atmosphere and shows the differences from the normal atmosphere. Then it was presented the installation of plant, which will have 3 cold rooms with controlled atmosphere, washing area, sizing and sorting area, precooling tank, packing area, engine room, warehouse and administrative area. The most technical part corresponds to the sizing and design of the cooling installation and the refrigerator in a controlled atmosphere. At the endidentified the environmental impact, financial analysis, critical points and the gains of the solution
Orbital magnetoelectric effect in nanoribbons of transition metal dichalcogenides
The orbital magnetoelectric effect (OME) generically refers to the appearance
of an orbital magnetization induced by an applied electric field. Here, we show
that nanoribbons of transition metal dichalcogenides (TMDs) with zigzag (ZZ)
edges may exhibit a sizeable OME activated by an electric field applied along
the ribbons' axis. We examine nanoribbons extracted from a monolayer (1L) and a
bilayer (2L) of MoS in the trigonal (H) structural phase. Transverse
profiles of the induced orbital angular momentum accumulations are calculated
to first order in the longitudinally applied electric field. Our results show
that close to the nanoribbon's edge-state crossings energy, the orbital angular
momentum accumulations take place mainly around the ribbons' edges. They have
two contributions: one arising from the orbital Hall effect (OHE) and the other
consists in the OME. The former is transversely anti-symmetric with respect to
the principal axis of the nanoribbon, whereas the latter is symmetric, and
hence responsible for the resultant orbital magnetization induced in the
system. We found that the orbital accumulation originating from the OHE for the
1L-nanoribbon is approximately half that of a 2L-nanoribbon. Furthermore, while
the OME can reach fairly high values in 1L-TMD nanoribbons, it vanishes in the
2L ones that preserve spatial inversion symmetry. The microscopic features that
justify our findings are also discussed.Comment: 14 pages, 16 figure
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