401 research outputs found
Acetoxilação de α-Pineno com catalisadores heterogéneos
Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção de grau de Mestre em Engenharia Química e BioquímicaEste trabalho teve como objectivo estudar a acetoxilação de α-pineno a acetato de α-terpinilo, na presença de catalisadores heterogéneos. Os catalisadores seleccionados consistem em sílica mesoestruturada - SBA-15, funcionalizada com grupos sulfónicos.
Os produtos da acetoxilação do α-pineno são acetatos (acetato de α-terpinilo, acetato de bornilo e acetato β-fenchilo) e hidrocarbonetos (canfeno, limoneno, tricicleno, y-terpineno, terpinoleno e α-terpineno).
Numa primeira fase do trabalho, foram preparados quatro catalisadores SBA-15 (C1, C2, C3 e C4), com diferentes quantidades de grupos ácido sulfónico. Estes materiais foram caracterizados recorrendo a diferentes técnicas, sendo estas difracção de Raios X, isotérmicas de adsorção-dessorção de azoto a 77 K, microscopia electrónica de transmissão e análise elementar.
Após a caracterização dos materiais, os catalisadores foram utilizados na acetoxilação de α-pineno. Observou-se que a actividade aumenta com o aumento da área superficial e volume de poros. Com o objectivo de optimizar as condições da reacção, foram estudados o efeito de diferentes parâmetros, tais como, massa de catalisador, temperatura, concentração inicial de α-pineno, na conversão de α-pineno e na selectividade para o produto desejado.
No sentido de estudar a estabilidade catalítica do catalisador C1, o qual mostrou a actividade mais elevada, foram efectuados ensaios consecutivos com a mesma amostra e nas mesmas condições. Após cinco ensaios, o catalisador mostrou ainda uma boa actividade inicial.
Do presente trabalho resultou um artigo, que será publicado numa revista científica da especialidade
Sobre o novo em design
Dissertação de Mestrado em Ciências da Comunicação
Cultura Contemporânea e Novas TecnologiasNum território atravessado por Arte e Técnica, a disciplina do design é inevitavelmente impelida para o novo. Mas que tensões e afinidades se manifestam nessa pressão para a inovação? Para pensar este tema parte-se da investigação de Boris Groys sobre o Novo na economia cultural. Para Groys o novo só é possível fora do espaço profano. A convicção de que o design opera nesse mesmo espaço profano, sugere a necessidade de uma questão prévia acerca da especificidade do contexto do design. Propõe-se aqui um contexto que se baseia na distinção entre banal e trivial. À luz destes conceitos revisitam-se incontornáveis questões, porventura não resolvidas, do modernismo e do pós-modernismo no design. Para lá de qualquer categorização histórica ou tipológica, pretende-se pensar o design como projecto moderno. Assim, o design enquanto projecto moderno é, não apenas um meio do homem agir sobre o mundo, mas antes, um meio de agir sobre si próprio. A inovação em design é, por conseguinte, uma oportunidade (ou uma obrigação) de auto-determinação, de auto-desenho, de self-design
Brand gender and consumer-based brand equity on Facebook: The mediating role of consumer-brand engagement and brand love
Brand gender has been suggested as a relevant source of consumer-based brand equity (CBBE). The purpose of this paper is to deepen understanding of the relationship between brand gender and CBBE by analyzing the mediating roleofconsumer–brandengagement (CBE)andbrandlove(BL)onthisrelationship.Thisresearchwas conducted on Facebook, the dominant global social media platform. The hypotheses were tested using structural equation modeling. Results support 6 of the 9 hypotheses, with a significant relationship between analyzed constructs. This study advances prior work by showing that brand gender has an indirect and relevant impact on CBBE through BL and CBE. Therefore, this research confirms the advantages of clear gender positioning and extends prior research by suggesting that brands with a strong gender identity will encourage BL and CB
Growth performance, biochemical composition and sedimentation velocity of Tetraselmis sp. CTP4 under different salinities using low-cost lab- and pilot-scale systems
Biomass harvesting is one of the most expensive steps of the whole microalgal production pipeline. Therefore, the present work aimed to understand the effect of salinity on the growth performance, biochemical composition and sedimentation velocity of Tetraselmis sp. CTP4, in order to establish an effective low-cost pilot-scale harvesting system for this strain. At lab scale, similar growth performance was obtained in cultures grown at salinities of 5, 10 and 20 g L-1 NaCl. In addition, identical settling velocities (2.4-3.6 cm h-1) were observed on all salinities under study, regardless of the growth stage. However, higher salinities (20 g L-1) promoted a significant increase in lipid contents in this strain compared to when this microalga was cultivated at 5 or 10 g L-1 NaCl. At pilot-scale, cultures were cultivated semi-continuously in 2.5-m3 tubular photobioreactors, fed every four days, and stored in a 1-m3 harvesting tank. Upon a 24-hour settling step, natural sedimentation of the microalgal cells resulted in the removal of 93% of the culture medium in the form of a clear liquid containing only vestigial amounts of biomass (0.07 ± 0.02 g L-1 dry weight; DW). The remaining culture was recovered as a highly concentrated culture (19.53 ± 4.83 g L-1 DW) and wet microalgal paste (272.7 ± 18.5 g L-1 DW). Overall, this method provided an effective recovery of 97% of the total biomass, decreasing significantly the harvesting costs.Agência financiadora
Portuguese national budget P2020
Foundation for Science and Technology (FCT) CMAR/Multi/04326/2013
ALGARED+ 1398 EP - INTERREG V-A Espana Portugal project
ALGACO2 project 023310
COST Action 1408 - European Network for Bio-products
FCT SFRH/BD/105541/2014info:eu-repo/semantics/publishedVersio
Nós a família a comunidade e as artes - interseções criativas a partir do jardim de infância
O presente relatório surge no âmbito da unidade curricular de Projeto, do curso de Mestrado em Intervenção e Animação Artísticas, e refere-se ao desenvolvimento de um projeto de intervenção que teve como designação «Nós, a família, a comunidade e as Artes»e que foi realizado em contexto de jardim de infância. Este projeto surgiu da necessidade de compreender qual o papel das experiências artísticas vivenciadas pelas crianças na aproximação entre a escola, a família e a comunidade.
O desenvolvimento do projeto estruturou-se em quatro momentos distintos: uma fase inicial, de Diagnóstico; a fase de Planificação, referente à preparação das atividades a desenvolver; a fase de Implementação, referente à concretização das diferentes propostas educativas; e a fasede Avaliação, na qual se avaliou e refletiu sobre o projeto.
Paralelamente ao desenvolvimento do projeto foi realizado também um estudo de investigação, orientado pela questão Em que medida a vivência de experiências com as linguagens artísticas pode facilitar a relação entre a escola, a família e a comunidade?.Este estudo, de caráter descritivo, desenvolveu-se numa lógica de investigação-ação, tendo como técnicas de recolha de dados a observação participante e a construção de um diário de bordo, os registos fotográficos e a aplicação de um questionário.
A avaliação do projeto demonstrou que as artes têm um papel muito importante na promoção de práticas que envolvem as crianças, as suas famílias e a comunidade. Verificou-se que se construíram novas formas de interação, tendo as relações entre todos os intervenientes sido intensificadas e aprofundadas. De igual modo, também se verificou que esta aproximação teve reflexos nas aprendizagens das crianças
Wearable lower limb neuroprosthesis: system architecture and control tuning
The use of functional electrical stimulation (FES) through neuroprosthesis is becoming a promising solution in lower limb neurorehabilitation. However, the wearability constraints and time-consuming tuning of stimulation parameters still limit the daily use of neuroprostheses. This work proposes two major contributions, namely: (i) a conceptual design and technical architecture of a fully wearable lower limb neuroprosthesis; and (ii) a Matlab-OpenSim framework that enables fast subject-and muscle-specific tuning of FES controllers based on OpenSim musculoskeletal models. The validation procedures for this study were divided into three phases: (i) Verification of the system architecture real-time requirements; (ii) evaluation of the reliability of the MATLAB-OpenSim framework for tuning PID controller; and (iii) its subsequent use in the neuroprosthesis control with a healthy subject. The obtained results demonstrated that the neuroprosthesis system was able to meet the real-time requirements, with control and data acquisition call periods below 10 ms. Further findings indicated reliable and stable behavior of the simulation-tuned PID controller with an overshoot of 9.82% and a rise time of 0.063 s. The trajectory tracking control results with the neuroprosthesis corroborated the robustness of the tuned PID controller in tracking the desired ankle trajectory (RMSE = 17.23 ± 2.97º and time delay = 0.21 ± 0.070 s).This work has been supported by the Fundação para a Ciência e Tecnologia (FCT) through
the Reference Scholarship under Grant SFRH/BD/147878/2019, the Stimulus of Scientific
Employment under Grant 2020.03393.CEECIND, and in part by the FEDER Funds through
the Programa Operacional Regional do Norte and national funds from FCT with the SmartOs
project under Grant NORTE-01-0145-FEDER-030386. It is also supported under the national
support to R&D units grant, through the reference project UIDB/04436/2020 and
UIDP/04436/2020
Is there a relation between environmental exposure to teratogenic substances during pregnancy and congenital anomalies in the newborn? A pilot study in Portugal
Background: Maternal occupation as a proxy of environmental exposure has been consistently associated with specific congenital anomalies (CA) in the foetus and newborn. On the other hand, geographical location of the mother such as place of residence and place of work have not been used as proxy for environmental exposures during pregnancy. We designed a pilot study aiming to investigate the association between maternal place of residence and workplace during pregnancy and CA in Portugal. Methods: Cases and controls are identified in the maternity unit. Cases are all live births with at least one CA delivered in the Barreiro hospital located in a heavy industrial area near Lisboa. Controls are the two normal births following each case. Residents outside the study area, stillbirths and women who decline to participate or are incapable of giving consent are excluded. A health professional interviews the mothers using a questionnaire adapted from the registry form of the Portuguese national registry of CA and includes information on places during pregnancy (residence, workplace, leisure), and demographic characterization as place of birth, infant sex, weight, description of CA, age of mother, ethnicity, maternal birth place. Maternal health and obstetric history, education, smoking, alcohol, drugs and medication use is also collected as potential confounders. Results: The pilot study started in January 2016 and at the moment two cases and four controls have been recruited without refusals. The study will continue to be implemented and it is proposed to start in other hospital units during 2016
Non-essential elements and their role in sustainable agriculture
Agricultural systems are constantly under environmental pressure, and the continuous rise of the global population requires an increasingly intensification of agronomical productivity. To meet the current global food demand, particularly in depleted ecosystems under adverse climate conditions, the development of novel agronomical practices, which ensure crop productivity while safeguarding minimal impact to the environment, must be encouraged. Since aluminium (Al), cobalt (Co), selenium (Se), silicon (Si) and sodium (Na) are not essential to plant metabolism, their benefits are often neglected or underestimated in agriculture; however, several studies support their advantages in sustainable agriculture when properly employed. The agronomical uses of these elements have been studied in the last decades, delivering important cues for the improvement of food and feed production worldwide due to beneficial effects in plant growth and productivity, nutrient balance, pest and pathogen resistance, water stress management, heavy-metal toxicity alleviation, and postharvest performance. However, their application has not been addressed as part of a holistic conservation strategy that supports the sustainability of agroecosystems. Here, we discuss the potential use of these elements in sustainable agriculture, and the knowledge gaps that hinder their effective integration into agronomical practices, which result in equally profitable applications while supporting environmental sustainability.info:eu-repo/semantics/publishedVersio
Is there a relation between environmental exposure during pregnancy and congenital anomalies in newborn? Preliminary results from a case-control study
Poster publicado em: European Journal of Medical Genetics. 2018;61(9):571. https://doi.org/10.1016/j.ejmg.2018.06.071BACKGROUND: Maternal exposure to environmental factors has been associated to the birth of a child with specific congenital anomalies (CA). The aiming of this study is to investigate the association between occupational exposure, maternal place of residence, workplace and leisure activities during pregnancy and CA
METHODS: In 2016, an observational, case control study was developed and is still in progress. Cases are live births, identified in the maternity unit, with at least one CA and controls are the two births without anomaly following each case. Residents outside the study area, stillbirths and women who decline to participate or are incapable to give consent are excluded
RESULTS: Were recruited to the study 116 live births (38 cases and 78 controls). The majority of cases reported living (68.4%) and spend leisure time (63.2%) in the industrial area. 57.7 of controls lives and 46.9% spend leisure time in same area. However no statistical differences were detected between them (p=0.195 for residency and p=0.175 for place of leisure). Cases work more frequently in Lisbon (21%) and residence area (15.8%) compared to controls (17.3% and 15.4% respectively) (p=0.057). A total of 44 CA were detected and the most frequently reported groups was the musculoskeletal system (34.1%) followed by CA of the ear and genital group (15.9% and 15.9 respectively).
CONCLUSION: Due to the small sample size, no statistically significant difference was found between cases and controls. Reason why it is necessary to continue the study and obtain the collaboration of other hospitals in the same area.info:eu-repo/semantics/publishedVersio
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