Structural Evolution of Ni-Ti Alloy Wires Produced by Hot and Cold Rotary Forging

Ni-Ti shape memory alloys (SMA), have interesting functional properties such as shape memory effect and superelasticity that enable their use in different segments. These functional characteristics are obtained through the thermomechanical processing (hot and cold). The hot deformation may promote the intended metallurgical transformations and the microstructural changes are improved by final cold deformation. These processes influence the final mechanical properties of the materials and, by consequence, their applications. This work focused on a Ni-rich Ni-Ti alloy, which may be used in the orthodontic archwires since the alloys used for this purpose need to show superelastic characteristics at room and oral temperature. It is sought by the mechanical and thermal treatments that the material displays an austenite finish temperature below room temperature. In this work, the characteristics of the thermomechanical processing are studied using samples representative of the different processing steps. For each processing step, the effect of the process parameters on the phase transformation temperature, superelasticity and shape memory effects was assessed and correlated to its microstructure. The structural analysis of each sample was performed by different techniques, which allowed the identification of the thermomechanical processing evolution. It was noticed that the austenite finish temperature was close to room temperature for all the steps. For all the samples, an austenite matrix at room temperature was observed. Different heat treatments were applied to identify the most suitable changes to be proposed along the rotary forging steps. Thermomechanical treatments were performed to understand and verify the structural evolution (by X-ray diffraction, using synchrotron radiation) and the mechanical behavior during the hot and cold deformations. These treatments allowed us to observe and discuss restoration phenomena, such as dynamic recovery and recrystallization. In addition, orthodontic archwires were studied in a reverse engineering approach to identify their structural characteristics and the corresponding functional behavior. The characterization of commercial functionally graded NiTi orthodontic archwire was performed and the introduction of graded functionality in conventional archwires was analyzed. This study aimed to contribute to the development of processing strategies that will give rise to more consistently uniform characteristics of Ni-Ti shape memory alloys and a minimization of the failures occurring during processing

The study of new NiTi actuators to reinforce the wing movement of aircraft systems

This research was funded by: Project PTDC/CTM-CTM/29101/2017-POCI-01-0145-FEDER-029101 funded by FEDER funds through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES, and Project POCI-01-0247-FEDER-033758 funded by Agência Nacional de Inovação, S.A. PT2020-SII&DT-Copromoção. This research was also supported by FEDER funds through the program COMPETE-Programa Operacional Factores de Competitividade, and by national funds through FCT-Fundação para a Ciência e a Tecnologia, under the project UIDB/EMS/00285/2020.UIDB/EMS/00285/2020, PAMI-ROTEIRO/0328/2013, CENTRO-01-0145-FEDER-000014-3362, POCI-01-0247-FEDER-033758Actuators using Shape Memory Alloy (SMA) springs could operate in different mechanical systems requiring geometric flexibility and high performance. The aim of the present study is to highlight the potential of these actuators, using their dimensional variations resulting from the phase transformations of NiTi springs (SMA) to make the movements of the system’s mobile components reversible. This reversibility is due to thermal-induced martensitic transformation of NiTi springs. The transformation promotes the extended and retracted of the springs as the phase changing (martensite–austenite) creates movement in part of the system. Therefore, the phase transition temperatures of NiTi, evaluated by differential scanning calorimetry (DSC), are required to control the dimensional variation of the spring. The influence of the number of springs in the system, as well as how impacts on the reaction time were evaluated. The different numbers of springs (two, four, and six) and the interspaces between them made it possible to control the time and the final angle attained in the mobile part of the system. Mechanical resistance, maximum angle, and the system’s reaction time using different NiTi springs highlight the role of the actuators. Fused Deposition Modelling (FDM)/Material Extrusion (MEX) or Selective Laser Sintering (SLS) was selected for shaping the composite matrix system. A new prototype was designed and developed to conduct tests that established the relationship between the recoverable deformation of the matrix suitable for the application as well as the number and distribution of the actuators.info:eu-repo/semantics/publishedVersio

QR code: tendência de evolução comercial no ponto-de-venda físico de retalho

Numa era em que o mundo online está cada vez mais inserido no quotidiano de qualquer pessoa, apercebemo-nos que o contacto com empresas físicas está em declínio (Araújo, 2015). Segundo um estudo, apurado pela E-commerce Europe2, estima-se que o comércio através da internet (e-commerce) tenha atingindo os 3,5 mil milhões de euros em 2015, registando um crescimento anual de 8%, em Portugal. Assim, dado este crescimento neste género de consumo, muitas empresas e clientes questionam-se se a loja física não estará a perder importância (Besouchet, 2015). Neste contexto, ainda que as vantagens das compras online sejam inegáveis (facilidade de comparação de preços, conforto e conveniência de entrega de mercadoria) para Besouchet (2015) nada supera a experiência de compra no ponto-de-venda físico. Este ponto-de-venda, oferece outras sensações e sentimentos, ligados aos cinco sentidos, (Blessa, 2010) que o consumo através da internet não permite tais como: sentir o toque do tecido, visualização da cor com exatidão, perceção olfática, entre outras… (Besouchet, 2015). Deste modo, esta dissertação assume o objetivo de repor a atenção dada às lojas físicas de outrora, tirando partido da tecnologia e do entretenimento lúdico. O meio tecnológico explorado foi o QR Code, uma área sobre a qual, ainda não existe muita investigação produzida, tornando-o, por conseguinte, particularmente pertinente, numa dimensão de estudo propícia para o consumo.In an era where the online world is increasingly inserted in the day to day life of every person, we realize that the contact with the companies is declining (Araújo 2015). According to a study made by E-commerce Europe2, it is estimated that the commerce trough the internet (e-commerce) has reached 3,5 thousand millions euros in 2015, registring an anual growth of 8% in Portugal. This way, due to the mentioned growth in this type of consumption, many companies and clients question themselves if the fisical store is not losing its meaning and importance (Besouchet 2015). In this context, even though the advantages of online shopping are evident (facility in comparing prices, comfort and convinience in the delivery) to Besouchet (2015) nothing overcomes the experience of buying in the selling point. The selling point offers diferente sensations and feelings attached to the five senses, (Blessa 2010) which the cosumerism trough the internet does not offer, such as: feeling the touch of the fabric, visualizing the color precisely, the perseption of smell, and others… (Besouchet 2015). This way, this dissertation theses had the intention of resetting the atention once given to the physical stores, taking advantage of the technology and the playful entertainment. The technológical mean explored was the QR code, an área which doesnt have much investigation yet, making it particularly pertinent, in a study dimension proper for consumerism

Identification of a Dental Anomaly in a Tiriyo Indigenous Park Patient by Computed Tomography: A Case Report

This report describes anatomical variations in an indigenous patient from the Brazilian Amazon. A 13-year-old indigenous girl attended the dental clinic for a routine examination. Clinically, a change in the coronary morphology of all upper incisors was observed; characterized by a shovel-shaped lingual surface-a feature considered a polygenic hereditary trait commonly found in native American people. The x-ray examination revealed the presence of a root anomaly in the left upper central incisor. A cone-beam computed tomography (CBCT) scan was performed, revealing the presence of a supernumerary root located on the lingual surface. A single wide canal, which bifurcated in the middle-third level into two canals with different foramina, was observed in the cervical portion. It is essential for dental surgeons to be aware of possible anatomical differences, especially considering the origin of the patient, to avoid interference in treatment success.Keywords: Abnormalities; Cone-beam Computed Tomography; Health Services; Indigenous; Tooth Roo

Análise Probabilística de Aterro sobre Solos Moles

No model correctly predicts a given system's reality, so that the engineering calculations have uncertainties, which may cause several kinds of errors. The constructions on soft clay deposits present a high difficulty due to such soil's high compressibility and low resistance. The geotechnical designs of embankments on soft soils are traditionally analyzed using a global safety factor obtained through deterministic methods, not incorporating the calculation's inherent uncertainties. On the other hand, the probabilistic approach makes it possible to quantify the uncertainties arising from the parameters' variability and the more comprehensive assessment of the expected safety level for the work through the probability of failure. In this way, it is possible to untie the idea that high safety factor values always guarantee safer projects. In this context, this study aims to compare the solutions obtained by the Probabilistic Methods of Rosenblueth, Monte Carlo, Latin Hypercube, and First Order Second Moment (FOSM), in addition to evaluating the results by means of a deterministic approach using the methods of Bishop Simplified, Janbu Simplified, Spencer and Morgenstern & Price. Stability analyses were performed using the Slide v.6 computational tool. The analyses show the importance of introducing the coefficient of variation in the parameters since the uncertainty directly affects the level of performance expected for the work.Nenhum modelo prevê perfeitamente a realidade de um determinado sistema; consequentemente, os cálculos em engenharia têm incertezas, que, por conseguinte vão repercutir diretamente em erros de diversos tipos. Em especial, as obras sobre depósitos de argilas moles apresentam uma alta dificuldade devido ao comportamento caracterizado por elevada compressibilidade e baixa resistência desse solo. Os projetos geotécnicos de aterros sobre solos moles são tradicionalmente analisados por intermédio de um fator de segurança global obtido por meio de métodos determinísticos, não incorporando as incertezas inerentes no cálculo. Já a abordagem probabilística possibilita a quantificação das incertezas oriundas da variabilidade dos parâmetros, bem como a avaliação mais abrangente do nível de segurança esperado para a obra através da probabilidade de falha. Desse modo, é possível desvincular a ideia que altos valores de fator de segurança sempre garantem projetos mais seguros. Neste contexto, o presente estudo tem como objetivo comparar as soluções obtidas pelos Métodos Probabilísticos de Rosenblueth, Monte Carlo, Hipercubo Latino e First Order Second Moment (FOSM), além de avaliar os resultados pela abordagem determinística pelos métodos de Bishop Simplificado, Janbu Simplificado, Spencer e Morgenstern & Price. As análises referentes a estabilidade foram realizadas com o auxílio da ferramenta computacional Slide v.6. Os resultados oriundos das análises evidenciam a importância da inserção do coeficiente de variação nos parâmetros, já que a incerteza repercute diretamente no nível de desempenho esperado para a obra

Variação especial e temporal de Peridinium umbonatum F. Stein, 1883 (Dinophyceae) e sua relação com o fitoplâncton total de uma lagoa rasa e oligotrófica no Brasil Central (Lagoa Bonita, Distrito Federal)

OBJETIVOS: O principal objetivo deste estudo foi investigar a distribuição temporal e espacial de Peridinium umbonatum e sua relação com as variáveis físicas e químicas da água das zonas pelágica e litorânea da Lagoa Bonita, localizada em Brasília, Distrito Federal; MÉTODOS: As amostras foram coletadas em três estações: duas na zona litorânea e uma na zona pelágica, a cada 15 dias, de abril de 2005 a março de 2006; RESULTADOS: P. umbonatum foi o único membro da classe Dinophyceae registrado durante todo o ciclo sazonal, com poucas exceções, tanto nas zonas litorâneas quanto na zona pelágica da Lagoa Bonita. O maior biovolume dessa alga (7,5 mm³.L-1) ocorreu perto da costa, no início da estação chuvosa, em novembro de 2005. Os menores valores de biovolume P. umbonatum foram registrados em maio e junho de 2005, meses tipicamente secos; CONCLUSÕES: P. umbonatum e a comunidade fitoplanctônica como um todo tiveram os maiores biovolumes nos dois pontos da zona litorânea, no final da estação seca e início das chuvas. Tanto a escala temporal quanto a espacial foram relevantes na ocorrência de P. umbonatum, sendo que a heterogeneidade espacial foi o fator preponderante durante o período de estudo. A estrutura das comunidades de plantas, sobretudo macrófitas submersas, influenciaram na dinâmica populacional de P. umbanatum que ocorreu em um lago raso, pobre em nutrientes e de tamanho pequeno, cujas características coincidem com as características de habitat descritas para o grupo funcional Lo estabelecido por Reynolds et al. (2002).AIM: The main goal of this study was to investigate the temporal and spatial distribution of Peridinium umbonatum and its relationship with the physical and chemical water variables of the pelagic and littoral zones of Lagoon Bonita, located in Brasília, Distrito Federal; METHODS: Samples were collected at three stations: two in the littoral zone and one in the pelagic zone, every 15 days from April 2005 through March 2006; RESULTS: P. umbonatum was the only member of class Dinophyceae recorded during the entire seasonal cycle, with few exceptions, in both the littoral and pelagic zones of Lagoon Bonita. The highest biovolume (7.5 mm³.L-1) of this alga occurred near shore at the beginning of the rainy season, in November 2005. Smaller values of P. umbonatum biovolume were recorded in May and June 2005, typical dry months; CONCLUSIONS: P. umbonatum and the phytoplankton community as a whole had higher biovolumes in the two littoral zone sites, at the end of the dry season and the beginning of the rains. Both, the temporal and spatial scales were relevant in the presence of P. umbonatum, and the spatial heterogeneity was the dominant factor along the study period. The plant community structure, mainly submersed macrophytes, has affected the P. umbonatum population dynamics that took place at shallow, nutrient-poor conditions, small-size lake, which matches with habitat template described to Lo functional classification established by Reynolds et al. (2002)

Design, Characterization and Biological Properties

Funding Information: This work was financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of projects UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO, the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB, project UIDP/04129/2020 of LEAF—Linking Landscape, Environment, Agriculture and Food—Research Center, and projects LA/P/0037/2020, UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication—i3N. Diana Araújo and Catarina Roma-Rodrigues were funded by FCT/MCTES, with grant numbers SFRH/BD/140829/2018 and SFRH/BPD/124612/2016, respectively. Publisher Copyright: © 2023 by the authors.FucoPol, a fucose-rich polyanionic polysaccharide, was used for the first time for the preparation of hydrogel membranes (HMs) using Fe3+ as a crosslinking agent. This study evaluated the impact of Fe3+ and FucoPol concentrations on the HMs’ strength. The results show that, above 1.5 g/L, Fe3+ concentration had a limited influence on the HMs’ strength, and varying the FucoPol concentration had a more significant effect. Three different FucoPol concentrations (1.0, 1.75 and 2.5 wt.%) were combined with Fe3+ (1.5 g/L), resulting in HMs with a water content above 97 wt.% and an Fe3+ content up to 0.16 wt.%. HMs with lower FucoPol content exhibited a denser porous microstructure as the polymer concentration increased. Moreover, the low polymer content HM presented the highest swelling ratio (22.3 ± 1.8 g/g) and a lower hardness value (32.4 ± 5.8 kPa). However, improved mechanical properties (221.9 ± 10.2 kPa) along with a decrease in the swelling ratio (11.9 ± 1.6 g/g) were obtained for HMs with a higher polymer content. Furthermore, all HMs were non-cytotoxic and revealed anti-inflammatory activity. The incorporation of FucoPol as a structuring agent and bioactive ingredient in the development of HMs opens up new possibilities for its use in tissue engineering, drug delivery and wound care management.publishersversionpublishe

Fatores associados ao parto cesárea nos sistemas público e privado de atenção à saúde

OBJECTIVE Identifying factors associated to Caesarean sections among the residents of Maringá-PR, according to the financing source for delivery. METHODS A cross-sectional study with data from 920 postpartum women interviewed between October 2013 and February 2014. Association analysis was performed by logistic regression. RESULTS Caesarean section rates were 55.5% in the Unified Healthcare System (SUS) and 93.8% in the private system. Factors associated with Caesarean section in the SUS were: previous Caesarean section (OR=8.9; CI=4.6-16.9), desire for Caesarean section early in pregnancy (OR=2.0; CI=1.1-3.6), pregestational overweight/obesity (OR=1.8; CI=1.1-2.8), and per capita family income higher than one minimum wage (OR=2.1; CI=1.3-3.4). In the private system, desire for Caesarean section early in pregnancy (OR=25.3) and a previous Caesarean section (OR=11.3) were strongly associated to its performance. CONCLUSION It is necessary to properly orientate all pregnant women who desire a Caesarean delivery, from both the SUS and the private system, about the inherent risks of the surgical procedure without indication. In the public health sector, guidelines should be focused on pregnant women with previous Caesarean delivery, with a per capita income higher than one minimum wage and those who are overweight or obese, as these women are more likely to have a Caesarean section.OBJETIVO Identificar factores asociados con la cesárea entre residentes de Maringá-PR, según la fuente de financiación del parto. MÉTODO Estudio transversal con datos de 920 puérperas entrevistadas entre octubre de 2013 y febrero de 2014. El análisis de asociación se hizo por regresión logística. RESULTADOS La tasa de cesáreas fue del 55,5% y del 93,8% en el Sistema Único de Salud (SUS) y en el sistema privado, respectivamente. Se asociaron a la cesárea en el SUS: realización de cesárea anterior (OR=8,9; IC=4,6-16,9), deseo por la cesárea en el inicio de la gestación (OR=2,0; IC=1,1-3,6), sobrepeso/obesidad pre gestacional (OR=1,8; IC=1,1-2,8) y renta familiar per capita mayor que un sueldo mínimo (OR=2,1; IC=1,3-3,4). En el sistema privado, el deseo por la cesárea en el inicio de la gestación (OR=25,3) y una cesárea anterior (OR=11,3) estuvieron fuertemente asociados con su realización. CONCLUSIÓN Es necesario orientar adecuadamente a todas las gestantes que desean el parto cesárea, en el SUS y el sistema privado, acerca de los riesgos inherente al procedimiento quirúrgico sin indicación. En el sector público de salud, deben ser foco de las orientaciones las gestantes con parto cesárea anterior, las con renta familiar per capita mayor que un sueldo mínimo y con sobrepeso u obesidad, quienes tienen más probabilidades de realizar cesárea.OBJETIVO Identificar fatores associados à cesárea entre residentes de Maringá-PR, segundo a fonte de financiamento do parto. MÉTODO Estudo transversal com dados de 920 puérperas entrevistadas entre outubro de 2013 e fevereiro de 2014. A análise de associação foi feita por regressão logística. RESULTADOS A taxa de cesariana foi de 55,5% e 93,8% no Sistema Único de Saúde (SUS) e no sistema privado, respectivamente. Associou-se à cesárea no SUS: realização de cesárea anterior (OR=8,9; IC=4,6-16,9), desejo pela cesárea no início da gestação (OR=2,0; IC=1,1-3,6), sobrepeso/obesidade pré-gestacional (OR=1,8; IC=1,1-2,8), e renda familiar per capita maior que um salário mínimo (OR=2,1; IC=1,3-3,4). No sistema privado, o desejo pela cesárea no início da gestação (OR=25,3) e uma cesárea anterior (OR=11,3) estiveram fortemente associados à sua realização. CONCLUSÃO É necessário orientar adequadamente todas as gestantes que desejam o parto cesárea, no SUS e no sistema privado, sobre os riscos inerentes ao procedimento cirúrgico sem indicação. No setor público de saúde, devem ser foco das orientações as gestantes com parto cesárea anterior, as com renda familiar per capita maior que um salário mínimo e com sobrepeso ou obesidade, as quais têm mais chances de realizar cesárea

Líquenes como bioindicadores de poluição atmosférica

Numa altura em que existem os mais variados equipamentos tecnológicos de avaliação da qualidade do ar recorrer a um organismo vivo para esse efeito não parece uma grande inovação a não ser que traga algum tipo de vantagem adicional, como seja permitir avaliar os efeitos da contaminação para além dos valores instantâneos obtidos por medições químicas. Os líquenes são seres vivos com características particulares, as hifas do fungo absorvem água diretamente da atmosfera, e por isso são particularmente sensíveis à poluição ambiental tornando-se um recurso a que qualquer pessoa pode recorrer para ter uma ideia da qualidade do ar que respira. Foi isso que tentámos fazer neste trabalho, identificar e comparar os líquenes de três locais, determinar a espécie a que pertencem e inferir sobre a qualidade do ar do local de onde os recolhemos, relativamente à quantidade de SO2 presente