Development of a system for adsorption measurements in the 77 – 500 K and 1 – 100 bar range

Adsorption is a phenomenon present in various systems important to the field of cryogenics, having a great deal of relevance in the development of vibration-free coolers: these are crucial for the cooling of sensitive detectors, as they offer the possibility of using a sorption compressor, do not have moving parts and do not induce unwanted mechanical vibrations in the system, maintaining its sensibility and greatly minimizing wear due to use. In the context of an ESA-funded project for the development of such a cooler, a study on adequate adsorption materials to use for the non-mechanical cryogenic compressor present in the final system was required. Considering this, a system for measurement of adsorption properties in the range of its operating pressures and temperatures was needed and, independently, also useful in future adsorption studies the laboratory decides to perform. A brief historical and functional review of the adsorption phenomenon, its applications in cryogenics, and available and various methods for its measurement is made. The design and assembly of an adsorption measurement system, through the volumetric (also known as manometric) method, for temperatures in the 77 K to 500 K range and pressures up to 100 bar is detailed. Proof pressure tests were made to validate the design of the vessel, with positive results. Other pre-measurement tests, such as heating and cooling assays, void and dead volume measurements, empty-vessel measurements, were all carried out with an intention to validate and characterize the developed system. A LabVIEWTM interface for the control and automatic acquisition of the system parameters was developed and tested throughout the whole process. Results were taken using a sample of HKUST-1 (also known as Cu3(BTC)2 or BasoliteTM C300) and compared against the results from another group, as well as a partner laboratory, from both their theoretical simulations and their commercial gravimetric system

The effect of 2-butyl-cyanoacrylate adhesive in osteotomies and bone grafts in rabbits: macroscopic and radiographic characteristics

OBJECTIVE: To evaluate the effect of butyl-2-cyanoacrylate tissue adhesive in osteotomies and bone grafts, with regard to macroscopic and radiographic characteristics. METHODS: Forty-eight rabbits were used, randomly divided into four groups of 12 animals, with observation periods of two, four, eight and 16 weeks. Both thoracic limbs were operated in each animal and two osteotomies were performed in each of the radii, withdrawing a bone fragment (bone graft) of 1 cm in length. On one side, the bone graft was then replaced and a drop of adhesive was applied to each of the osteotomies. On the other side, the same procedure was performed without applying the adhesive. The rejection level for the nullity hypothesis was set at 0.05% or 5%. RESULTS: Blue marks were present in all the surgical specimens in which adhesive was applied. From the fourth week onwards, there was absence of movement of the bone grafts with adhesive and control. In group A, in the proximal osteotomies with adhesive, there was less deviation of the bone graft (p = 0.02). In group C, the union (p = 0.03) and the integration of the bone graft (p = 0.02) were better in the proximal osteotomies with adhesive. CONCLUSIONS: The adhesive was not completely metabolized within 16 weeks. There was clinical consolidation of the osteotomies within four weeks. The adhesive stabilized the bone graft within the first weeks and did not interfere with the consolidation of the osteotomies, or the integration of the bone graft in radiographic observations.OBJETIVO: Avaliar o efeito do adesivo tecidual butil-2-cianoacrilato em osteotomias e enxerto ósseo (EO), sob o aspecto macroscópico e radiográfico. MÉTODOS: Foram utilizados 48 coelhos, divididos aleatoriamente em quatro grupos de 12 animais, com períodos de observação de duas, quatro, oito e 16 semanas. Foram operados os dois membros torácicos de cada animal e realizadas duas osteotomias em cada um dos rádios, com a retirada de um fragmento ósseo (EO) de 1cm de comprimento. De um lado foi recolocado o EO no local e aplicada uma gota do adesivo em cada uma das osteotomias. No outro lado, foi realizado o mesmo procedimento sem a aplicação do adesivo. Fixou-se em 0,05 ou 5% o nível de rejeição da hipótese de nulidade. RESULTADOS: Presença de marcas azuis em todas as peças cirúrgicas em que foi utilizado o adesivo. A partir da quarta semana, ausência de movimento dos EO com adesivo e controle. No grupo A, nas osteotomias proximais com adesivo, ocorreu menos desvio do EO (p = 0,02). No grupo C, a união (p = 0,03) e a integração do EO (p = 0,02) foram melhores nas osteotomias proximais com adesivo. CONCLUSÕES: O adesivo não foi totalmente metabolizado com 16 semanas. Há consolidação clínica das osteotomias em quatro semanas. O adesivo estabilizou o EO nas primeiras semanas e não interferiu na consolidação das osteotomias, assim como na integração dos EO a observação radiográfica.UNIVÁS FACIMPAUNIFESP Departamento de OrtopediaUNIFESP, Depto. de OrtopediaSciEL

Flock Nocturnal Activity: Is There a Rotative Guard?

Animal activity during the night period is of enormous importance, since it represents approximately half of animals’ lives, and monitoring it during this period makes it possible to detect problems related to well-being and safety, and allows us to infer energy expenditure on the basis of their activity level. The present study analyzes a sheep activity dataset created during the night period to validate non-invasive techniques of monitoring that can be used to infer energy expenditure at night and to detect abnormal nocturnal activity. The study allowed us to detect cyclic changes in activity during the night period, which is composed of inactive and active periods, and to identify sheep lying positions. The analysis of the joint activity of the flock allowed us to perceive a time lag in the rest cycles, which consisted of periods of activity of ewes undone between elements of the flock. Although it does not allow us to identify the components of the period of inactivity, since the method used does not monitor brain activity, the results allow us to confirm the cyclical character of the nocturnal activity of sheep that has been reported in the literature, as well as their typical posture when lying down. Although this is an exploratory application with a very small number of animals, the similarity between the results obtained and the results documented in the existing literature, which have mostly been obtained using invasive methods, is encouraging, and suggests it is possible to rely on activity monitoring processes based on inertial sensors.info:eu-repo/semantics/publishedVersio

Modelos Mistos Ortogonais com Amostras de Dimensão Aleatória

A aplicação da análise de variância (ANOVA) a situações em que as dimensões das amostras não são previamente conhecidas, pode ser uma situação bastante comum. Tal ocorre, por exemplo, quando a recolha das observações é realizada num período fixo de tempo ou quando podem ocorrer falhas de observações. Nestes casos é mais correto considerar as dimensões das amostras como realizações de variáveis aleatórias independentes. São consideradas três distribuições distintas para as dimensões das amostras: - a distribuição de Poisson, quando a ocorrência das observações corresponde a processos de contagem; - a distribuição Binomial, caso exista um limite superior para a dimensão das amostras que nem sempre é atingido devido à ocorrência de falhas de observações; - a distribuição Geométrica [Binomial Negativa], quando o número de observações corresponde ao número de ocorrências até ao primeiro sucesso [s-ésimo sucesso]. O objetivo do presente trabalho é estender a teoria dos modelos mistos ortogonais ao caso em que as dimensões das amostras são desconhecidas. A formulação do modelo é feita considerando situações de estabilidade, o que significa que as estatísticas de teste têm a mesma distribuição, quer para a parte de efeitos fixos, quer para a parte de efeitos aleatórios do modelo, quando a hipótese nula se verifica. A aplicabilidade da abordagem proposta é ilustrada através de estudos referentes ao desemprego, em alguns países da União Europeia, com dados obtidos através da PORDATA - Base de dados de Portugal contemporâneos. Os resultados obtidos sugerem que a utilização da nossa abordagem, pode evitar a ocorrência de falsas rejeições, o que é confirmado através da realização de alguns estudos com dados simulados.Applying analysis of variance (ANOVA) where the samples dimensions are not known in advance is a very common situation. This occurs, for example, when observations are collected within a fixed time period or when some observations failures may occur. In these cases it is more appropriate to consider the sample sizes as realizations of independent random variables. Three different distributions are considered for the sample sizes: - the Poisson distribution, when the occurrence of observations corresponds to counting processes; - the Binomial distribution, when we have an upper bound for the sample sizes, which is not always achieved, since failures may occur; - the Geometric [Negative Binomial] distribution, for samples constituted by the observations taken until a success [until s successes]. The aim of the present work is to extend the theory of the orthogonal mixed models to situations where the sample sizes are not known in advance. The model formulation is done considering stable statistics, which means that the test statistics have the same distribution whether referring to the fixed or the random effects part of the model, when the tested hypothesis holds. The applicability of the proposed approach is illustrated through some studies on real data, considering the unemployement in the European Union, obtained from PORDATA - Base de dados de Portugal contemporâneos. The obtained results suggest that false rejections may be avoided when applying our approach, which is confirmed by carrying out some simulation studies

A INDEPENDÊNCIA DE ANGOLA E OS CONTEXTOS DAS NEGOCIAÇÕES COM OS COLONIZADORES

O presente artigo, de natureza qualitativa, buscou refletir sobre o processo de independência de Angola, a partir de revisão bibliográfica e análise documental. Dentre outras questões, verificou-se que os avanços e retrocessos daquilo que podia ser a plataforma negocial da transição colonial para a autodeterminação dos angolanos (Acordo de Alvor), estaria relacionada com as estratégias coloniais de negociação junto às potências dominantes da época (URSS e EUA)

Aproximação numérica de equações diferenciais parciais com p-Laplaciano e memória

Neste trabalho, faz-se um estudo sobre a aplicação do método dos elementos finitos na resolução de uma equação diferencial parcial não linear do tipo parabólico com memória da forma [...]In this work, a study is carried out on the application of the finite element method for solving a nonlinear parabolic partial diferential equation with memory of the form [...]FCT - Fundação para a Ciência e Tecnologia e Grant BID/ICIFC/Santander Universidades-UBI/2015

A criação artística contemporânea no contexto das universidades seniores: um caso de estudo

Mestrado em Criação artística e ContemporâneaAs Universidades Seniores têm vindo a assumir um papel cada vez mais preponderante nas transformações das sociedades ocidentais atuais, as quais têm a responsabilidade de integrar, absorver e até mesmo beneficiar das mais-valias caraterísticas do aluno sénior. São portanto o reflexo das mudanças de paradigma do adulto sénior, permitindo variadíssimas possibilidades e atividades orientadas para este público. A proposta de novas práticas e metodologias é consequentemente, desejável a partir de novas abordagens didáticas de ensino que tentam acompanhar a disponibilidade de informação facilitadora do acesso ao conhecimento. A diversidade de meios e o cruzamento de várias disciplinas artísticas apresentam-se como componentes de um processo que se pretende dinâmico e atual. Neste relatório de estágio, coloca-se a questão da valorização da Criação Artística, através de uma abordagem contemporânea, na configuração das ofertas educativas no seio das Universidades Seniores em geral, e da Universidade Sénior de Ovar em particular. Como tal é proposto o desenvolvimento do projeto Incubadora Artística como configuração experimental daquilo que é admitido como possibilidade alargada de aproximação à arte, em geral, e à arte contemporânea, em particular, por parte do aluno sénior conhecendo e explorando as diferentes expressões artísticas, bem como usando as mesmas nas suas próprias produções artística.Senior universities have been playing an increasingly important role in the transformation of today’s Western societies. These have the responsibility of integrating, absorbing and even benefitting from the valuable characteristics of the senior students. Therefore, they are the reflection of the paradigm shifts allowing a wide range of possibilities and activities aimed at this particular audience. The proposal of new practices and methodologies are consequently desirable based on the new teaching didactic approaches that try to keep up with the availability of information that facilitates the access to knowledge. The diversity of resources and the crossing of different artistic subjects are presented as components of a process intended to be dynamic and current. This training report, raises the issue regarding the value of artistic creation through a contemporary approach in the selection of the educational offer in the senior universities, and more specifically, in the Senior University of Ovar. Having this in mind, we propose the development of the Art Incubator Project as an experimental setup of what is admitted to be a possible extended approach to art, in general, and contemporary art, in particular by the senior student. This way the student can acknowledge and explore the different artistic expressions as well as use these in their own artistic productions

Impact of Institutional Support on Export Performance

Artigo publicado em revista científica internacionalThis paper examines institutional support (financial and marketing support) on export-oriented firms’ performance or so-called born globals. We develop a model to address how financial and marketing support can help young entrepreneurial firms to overcome the liability of newness and smallness in gaining competitive capabilities. Using a quantitative method, data were collected from 217 manufacturers and service sectors in Malaysia, an emerging Southeast Asian market. The results suggest that government assistance in marketing leads to competitive capabilities and export performance; however, financial support neither contributes to competitive capabilities nor export performance. We found the significant role of competitive capabilities as a mediator in enhancing the relationship between marketing support and export performance. Practical implications drawn from this result can be offered as guidelines for the policymakers in supporting young entrepreneurs that lead to competitive capabilities and superior performance.info:eu-repo/semantics/publishedVersio