A cellulose liquid crystal motor: a steam engine of the second kind

The salient feature of liquid crystal elastomers and networks is strong coupling between orientational order and mechanical strain. Orientational order can be changed by a wide variety of stimuli, including the presence of moisture. Changes in the orientation of constituents give rise to stresses and strains, which result in changes in sample shape. We have utilized this effect to build soft cellulose-based motor driven by humidity. The motor consists of a circular loop of cellulose film, which passes over two wheels. When humid air is present near one of the wheels on one side of the film, with drier air elsewhere, rotation of the wheels results. As the wheels rotate, the humid film dries. The motor runs so long as the difference in humidity is maintained. Our cellulose liquid crystal motor thus extracts mechanical work from a difference in humidity.

Optimização dos parâmetros de um robô hexápode através de algoritmos genéticos

Mestrado em Engenharia Electrotécnica e de Computadores

Construção de um robô trepador com locomoção através de rodas e adesão através de meios magnéticos

Mestrado em Engenharia Electrotécnica e de Computadores

A influência da idade nos parâmetros metabólicos durante a marcha com andarilho

Introdução: Estruturalmente, a marcha é modificada de acordo com as características de cada individuo, sua natureza morfológica, tipo de atividade, idade e a presença de determinadas doenças, entre outros fatores. Devidas as alterações fisiológicas de envelhecimento, o custo energético da marcha normal por si só é superior nos idosos comparativamente com os jovens. Objetivo: Analisar a influência do uso de andarilho com rodas e fixo nos parâmetros metabólicos de indivíduos com mais de 60 anos e em jovens. Metodologia: realizou-se um estudo analítico transversal numa amostra de 21 voluntários, sendo 11adultos jovens (idade compreendida entre 18 e 25 anos) e 10 são adultos com idade superior a 60 anos. Utilizou-se o sistema K4b2 COSMED de forma a recolher os dados relativos ao consumo energético, quociente respiratório e volume de CO2 produzido. Os participantes realizaram os diferentes tipos de marcha (marcha normal, a três pontos com andarilho fixo, a três pontos modificada com andarilho fixo, a três pontos com andarilho com rodas e a três pontos modificada com andarilho com rodas) durante 10 minutos num percurso rectilíneo de 20 metros. Para a análise estatística recorreu-se ao software IBM SPSS Statistics v20 com um nível de significância de 0,05. Resultados: observou-se que á exceção da marcha normal em todos os outros tipos de marcha com andarilho, os participantes com mais de 60 anos, apresentam valores significativamente superiores aos dos jovens, nomeadamente nas marchas com andarilho fixo, a 3 pontos e a 3 pontos modificada e com andarilho de rodas, na marcha a 3ponto modificada. Verificaram-se diferenças apenas no grupo dos jovens, pois a marcha normal apresentou valores significativamente maiores que as restantes. Conclusão: A idade influenciou os parâmetros metabólicos da marcha normal e com andarilhos fixo e móvel apresentando os idosos um maior gasto energético, bem como os METS utilizados.

Robótica móvel: sistema de condução autónoma

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica Ramo Automação e Electrónica Industrial

A literature review on the optimization of legged robots

Over the last two decades the research and development of legged locomotion robots has grown steadily. Legged systems present major advantages when compared with ‘traditional’ vehicles, because they allow locomotion in inaccessible terrain to vehicles with wheels and tracks. However, the robustness of legged robots, and especially their energy consumption, among other aspects, still lag behind mechanisms that use wheels and tracks. Therefore, in the present state of development, there are several aspects that need to be improved and optimized. Keeping these ideas in mind, this paper presents the review of the literature of different methods adopted for the optimization of the structure and locomotion gaits of walking robots. Among the distinct possible strategies often used for these tasks are referred approaches such as the mimicking of biological animals, the use of evolutionary schemes to find the optimal parameters and structures, the adoption of sound mechanical design rules, and the optimization of power-based indexes.

The discovery of three lost ‘Salting’ carpets: science as a tool for revealing their history

Thesis presented at the Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, to obtain a Master degree in Conservation and Restoration,Specialization in Textiles

Low cost inertial-based localization system for a service robot

Dissertation presented at Faculty of Sciences and Technology of the New University of Lisbon to attain the Master degree in Electrical and Computer Science Engineering

The Portuguese Administrative Elite, 1851-1910

The aim of this article is to examine the composition and patterns of recruitment of the ministries’directors-general, as well as to assess the interconnections between bureaucracy and politics, from the beginnings of Regeneração (1851) until the breakdown of Monarchy (1910). The post of director-general was considered one of “political trust”, that might be filled by individuals from outside the civil service, and the selection and de-selection of officeholders depended exclusively on the ministers’ will. Nonetheless, most directors-general were experienced bureaucrats, boasting a steady career as civil servants, and remained in office for long terms, regardless of ministerial discontinuities. In other words, High Administration became relatively immune to party-driven politics. Due to their professional background and lengthy tenure, directors-general were usually highly skilled specialists, combining technical expertise and practical knowledge of the wheels of state bureaucracy. Hence, they were often influential actors in policy-making, playing an active (and sometimes decisive) part behind the scenes, in both designing and implementing government policies. As regards their social profile, directors-general formed a cohesive and homogeneous elite group: being predominantly drawn from urban middle class milieus, highly educated, and appointed to office in their forties.

Aspergilli and Penicillia related to the surface of ripening italian grana type cheese and its ripening environment

Information available on the mycoflora associated to ripening Italian “grana type” cheese is very poor. Recently, ochratoxin A (OTA) was detected in samples of packed grated cheese [1]; therefore, the need of information to perform a risk management was highlighted. Moreover, sterigmatocystin (STC) has been reported in cheese and it is considered an emerging problem. Despite the fact that both of them are mycotoxins included in group 2B by IARC [2,3], no European regulation exists. So, the main goal of this work is to give for the first time a general overview about Penicillia and Aspergilli growing on the surface of ripening “grana type” cheese, with particular attention on mycotoxigenic species. To perform this, in 2013 and 2014 crust samples were scratched from ripening grana cheese wheels and also Potato Dextrose Agar plates were exposed to monitor ripening house air. Then, 140 fungal isolates were randomly chosen, purified and monosporic colonies were obtained for their identification at specie level. A polyphasic approach is followed, based on morphological characterisation, toxic extrolites profiling and gene sequencing. The identification is still in progress, but the first results based on the morphological approach showed the presence of mycotoxigenic Aspergilli (Aspergillus flavus and A. versicolor) and various Penicillium species; among them Penicillium chrysogenum, P. implicatum and P. solitum were identified. Only P. chrysogenum was reported to produce the mycotoxins cyclopiazonic acid (CPA) and roquefortine-C (ROQ-C) [4]. These results will be presented and discussed. [1] A. Biancardi, R. Piro, G. Galaverna, C. Dall’Asta, "A simple and reliable liquid chromatography–tandem mass spectrometry method for determination of ochratoxin A in hard cheese" International Journal of Food Sciences and Nutrition 64 (5), 2013, 632 – 640. [2] International Agency for Research on Cancer (IARC) “IARC Monographs on the Evaluation of Carcinogenic Risks to Humans” 31, 1983, 191 – 199. [3] International Agency for Research on Cancer (IARC) “IARC Monographs on the Evaluation of carcinogenic Risks to Humans”, suppl. 7, 1987, 72. [4] J. I. Pitt, D. A. Hocking, “Fungi and Food Spoilage” 1997, 291.

Efeito da porosidade nas propriedades físicas, mecânicas e tribológicas de mós abrasivas

Dissertação de mestrado integrado em Engenharia de Materiais

“PhenoWorld”: a new multidimensional strategy for studying behaviour in rodents

Tese de Doutoramento em Ciências da Saúde

Um chronographo de construção simples, permittindo registrar intervallos de tempo de 1 a 60 segundos

Descriptive memorial of a chronograph made from a common chronoscop (Eastman Timer). The chronoscop has been modified in order to permit to adjust distinct cog-wheels, everyone in its turn, to the axis of the seconds hand. Each of these cog-wheels holds a definite number of teeth accordingly with the time interval ones desire to record. A wheel with 20 teeth, for instance, is available for recording time in periods of each three seconds, another wheel with 6 teeth, will reckon time in intervals of 10 seconds and so on. These wheels may be interchanged most easily, which enables, with the same apparatus, to have at hand a time recorder for any time interval between one and sixty seconds. To register the time the apparatus is connected with a dry cell. A wire is attached to a binding post on the metal case of the apparatus, another wire being connected with an isolated binding post placed in front of the cog-wheel and fastened to a platinum point allowing open or shut the circuit, every time one of the cogs of the wheel comes into contact with this platinum point. A signal magnet is placed also in the circuit for writing the time intervals on the revolving drum.

Església, poder i societat als comtats catalans d'origen carolingi (877-1010)

El projecte de recerca “Església, poder i societat als comtats catalans d'origen carolingi (877-1010)” contempla l'estudi de l'Església catalana del segle X en tots els seus vessants: com a estructura formada per diferents institucions (seus episcopals, cenobis, parròquies i esglésies-oratoris); com a conjunt de persones (clergues i laics que participen de diferent manera i amb diferent implicació dels afers eclesiàstics); en relació al poder polític-administratiu dels comtats catalans (comtes, vescomtes, senyors i altres delegats del poder i la justícia); com en relació amb els aspectes socioeconòmics i d'ordenació territorial (la gran massa de camperols, l'acaparament de terres per part dels grans propietaris, l'articulació d'un sistema de rendes, els vincles entre persones de diferents rangs, la compartimentació d'un espai creixent). Observem, doncs, que l'Església catalana altmedieval resta present en tots els àmbits de la vida i que el seu estudi permet, de retruc, un coneixement més profund i rigorós de la societat. Tot això, contextualitzat durant el segle X, a cavall entre dos períodes ben estudiats i que en ocasions l'han ennuvolat. El segle X és un període privilegiat per a l'estudi d'un bon nombre de dinàmiques polítiques, socials, econòmiques i culturals que demostren que aquesta centúria tenia una personalitat pròpia i que la posen en rellevància respecte als temps anteriors i posteriors. La historiografia tradicional altmedieval catalana tendeix a buscar l'origen dels canvis socials, institucionals i polítics, de la Catalunya medieval, en dos moments concrets: el món carolingi o els anys immediatament posteriors al canvi de mil•lenni. No obstant això, l'augment de fonts històriques, el millor coneixement dels conceptes i de les institucions i l'apropament a la història mitjançant nous enfocaments i paradigmes, permet visualitzar el segle X com a moment de continuació, però també de naixement de situacions prou importants com per a no ser negligides.

« L'esthétique du chant dans la piété calviniste aux premiers temps de la Réforme (1536-1545) »

Contrairement aux idées reçues, l'esthétique assume bien une fonction dans les formes rituelles adoptées par les Eglises issues de la Réforme calviniste. Mais il revient moins à l'image, considérée avant tout comme une source de distraction, qu'à la musique de porter cette dimension dans la piété réformée. Retraçant la formation de la pensée calvinienne sur la question des rapports entre culte et musique entre 1536 et 1543, cette étude montre comment le théologien en vient durant ces années à considérer que le chant des psaumes permet de concilier dans la dévotion, un processus cognitif, guidé par le sens des paroles, et un mouvement affectif, suscité par la mélodie. C'est, aux yeux de Calvin, de la jonction de ces deux dynamiques que naît l'élévation spirituelle à laquelle le culte doit conduire. Notwithstanding common belief, aesthetics had an important function in ritual forms implemented by Reformed Calvinist Churches. The impact of aesthetics on reformed piety rested less on images, considered to be a source of distraction, than on music. By reconsidering the evolution of Calvin's thoughts on the relationship between music and religious services between 1536 and 1543, this study reveals how Calvin came to consider that by singing the psalms, Christians could conciliate in prayer a cognitive process which was to be guided by both the meaning of the words and the emotions triggered by the tune. For Calvin, the spiritual elevation to which religious services should lead was to emerge from the conjunction of these two impetuses.