Gas mass-flow meters: Principles and applications

Gas mass-flow meters (GMFM) for original equipment manufacturers (OEM) applications are presently found in a relatively easy and cheap way. GMFM may be applied in a number of different situations but technical formation concerning its principles of measurement and applications are still misleading. In this paper, the principles of GMFM measurement are discussed and the operating parameters are clarified. A concept of gas mass-flow response factor is introduced and further used in a model for gas mass-flow measurement that is suitable to any gas mixture of known composition. In addition, a model for the application of GMFM to dynamic volumetric methods of dilution is presented and generalized

Quantum Spin-11 Anisotropic Ferromagnetic Heisenberg Model in a Crystal Field: A Variational Approach

A variational approach based on Bogoliubov inequality for the free energy is employed in order to treat the quantum spin-$1$ anisotropic ferromagnetic Heisenberg model in the presence of a crystal field. Within the Bogoliubov scheme an improved pair approximation has been used. The temperature dependent thermodynamic functions have been obtained and provide much better results than the previous simple mean-field scheme. In one dimension, which is still non-integrable for quantum spin-$1$, we get the exact results in the classical limit, or near-exact results in the quantum case, for the free energy, magnetization and quadrupole moment, as well for the transition temperature. In two and three dimensions the corresponding global phase diagrams have been obtained as a function of the parameters of the Hamiltonian. First-order transition lines, second-order transition lines, tricritical and tetracritical points, and critical endpoints have been located through the analysis of the minimum of the Helmholtz free energy and a Landau like expansion in the approximated free energy. Only first-order quantum transitions have been found at zero temperature. Limiting cases, such as isotropic Heisenberg, Blume-Capel and Ising models have been analyzed and compared to previous results obtained from other analytical approaches as well as from Monte Carlo simulations

The forward- and the equity-premium puzzles: two symptoms of the same illness?

Using information on US domestic financial data only, we build a stochastic discountfactor—SDF— and check whether it accounts for foreign markets stylized factsthat escape consumption based models. By interpreting our SDF as the projection ofa pricing kernel from a fully specified model in the space of returns, our results indicatethat a model that accounts for the behavior of domestic assets goes a long waytoward accounting for the behavior of foreign assets prices. We address predictabilityissues associated with the forward premium puzzle by: i) using instruments that areknown to forecast excess returns in the moments restrictions associated with Eulerequations, and; ii) by pricing Lustig and Verdelhan (2007)’s foreign currency portfolios.Our results indicate that the relevant state variables that explain foreign-currencymarket asset prices are also the driving forces behind U.S. domestic assets behavior.

Molecular analysis of anterior endoderm during Xenopus development: a funtional and genomic approach

Tese de doutoramento em Biologia (Biologia do Desenvolvimento), apresentada à Universidade de Lisboa através da Faculdade de Ciências, 2008Fundação para a Ciência e Tecnologia (FCT), (SFHR/BD/10035/2002

The Forward- and the Equity-Premium Puzzles: Two Symptoms of the Same Illness?

We build a pricing kernel using only US domestic assets data and checkwhether it accounts for foreign markets stylized facts that escape consumptionbased models. By interpreting our stochastic discount factor as the projection ofa pricing kernel from a fully specified model in the space of returns, our results indicatethat a model that accounts for the behavior of domestic assets goes a longway toward accounting for the behavior of foreign assets. We address predictabilityissues associated with the forward premium puzzle by: i) using instrumentsthat are known to forecast excess returns in the moments restrictions associatedwith Euler equations, and; ii) by pricing Lustig and Verdelhan (2007)'s foreigncurrency portfolios. Our results indicate that the relevant state variables that explainforeign-currency market asset prices are also the driving forces behind U.S.domestic assets behavior.

Estratégias de conservação de trilhas do Parque Nacional da Chapada dos Guimarães, Mato Grosso, Brasil.

Ocorreu um diagnóstico do estado de conservação de duas trilhas do Parque Nacional da Chapada dos Guimarães (PNCG) por meio de uma adaptação do método Visitor Impact Management (VIM). Pretendeu-se contribuir com o monitoramento sistematizado dos impactos existentes nessas trilhas consideradas estratégicas para a unidade de conservação. Os indicadores de impacto (erosão, alargamento, raízes expostas, carreiros, lixo, dano a vegetação e atalhos) foram quantificados e georreferenciados. O registro dos indicadores foi sistematizado por meio de um sistema de informações geográficas (SIG). As duas trilhas apresentaram dois indicadores com maior incidência (raízes expostas e dano a vegetação). Não houve diferença estatística que apontasse uma trilha com maior prioridade de recuperação que outra (χ2 = 6,4, gl=5, p=0,27). É necessário elaborar e executar um plano emergencial de manutenção dessas trilhas. Posteriormente essa atividade deverá integrar o plano de manejo da unidade de conservação

Abordagem clínica dos traumatismos uretrais

Trabalho final de mestrado integrado em Medicina área cientifica de Urologia, apresentado á Faculdade de Medicina da Universidade de CoimbraIntrodução: As lesões uretrais são pouco frequentes e é raro terem, isoladamente, graves riscos imediatos. Elas estão, contudo, entre as lesões mais nefastas para o sistema urinário em termos de sequelas a longo prazo, nomeadamente as estenoses, a incontinência urinária e a disfunção eréctil. Objectivo: Neste trabalho, propomo-nos a estudar de uma forma consistente e sistemática o estado da arte na abordagem do traumatismo da uretra masculina, feminina e da criança. Daremos particular importância à sua epidemiologia, etiologia e mecanismos lesionais, formas de apresentação, diagnóstico, tratamento e sequelas. Material e Métodos: O tema desta dissertação foi revisto utilizando a interface de pesquisa PubMed da Medline. A pesquisa foi restringida a artigos publicados desde o ano 1990 até à actualidade (Março de 2013), em língua portuguesa, inglesa, francesa e espanhola. Os artigos foram selecionados pela relevância do seu conteúdo, sendo que alguns foram excluídos pelo facto de existirem artigos semelhantes mais recentes. Foi também realizada uma pesquisa através de um manual de referência de Urologia. Resultados: Os traumatismos uretrais podem ser categorizados de acordo com o mecanismo de lesão (i.e., trauma por contusão versus trauma penetrante) e com a localização (i.e., uretra posterior versus uretra anterior). A lesão da uretra posterior está classicamente associada a fracturas pélvicas resultantes de acidentes de viação, enquanto o traumatismo uretral anterior decorre mais frequentemente de má instrumentação médica ou contusão perineal. A extensão da lesão uretral pode variar desde o simples estiramento até à rotura parcial ou total. A abordagem inicial e o aparecimento de complicações dependem em larga medida da localização da lesão, do seu mecanismo causal, sua extensão e da terapêutica realizada. Conclusão: A iatrogenia continua a ser a principal causa de traumatismo da uretra. O diagnóstico de traumatismo fechado da uretra anterior não suscita grandes hesitações no seu reconhecimento. O seu tratamento está bem descrito na literatura e envolve a introdução de um cateter suprapúbico em urgência. A atitude seguinte depende da gravidade e extensão da lesão. Quanto aos traumatismos abertos e às lesões uretrais associadas à fractura do pénis, o tratamento cirúrgico imediato é defendido unanimemente. As roturas da uretra posterior são traumatismos graves, frequentemente associados a fracturas instáveis da bacia, que devem ser encaminhados para equipas médicas experientes em hospitais de referência. O seu tratamento continua a ser alvo de discussão, no entanto, a intervenção gold standard continua a ser a uretroplastia diferida. Apesar de promissor, são necessários mais estudos que demonstrem as vantagens de um realinhamento endoscópico precoce no tratamento desta lesão.Introduction: Although relatively uncommon, urethral injuries can lead to significant morbidity to the urinary tract. Long term consequences include erectile dysfunction, stricture and incontinence. Objectives: This review article intended to consistently access the state of the art in the medical approach of male, female and child urethral trauma. In order to do so, we will give particular importance to its epidemiology, etiology, injury mechanisms, clinical presentation, diagnosis, management and complications. Material and Methods: The information for this review was compiled by searching the Pubmed (Medline) database. Only articles in Portuguese, English, French and Spanish, published since 1990 until nowadays (March 2013) were considered. Papers were prioritized by relevant content and some were excluded due to the similarity with more recent articles. It was also made a research on a textbook which is a reference in Urology. Results: Urethral trauma can be categorized according to its injury mechanism (blunt or penetrating injury) and location (posterior or anterior urethra). While injuries to the anterior urethra are often associated with careless instrumentation or straddle fractures, those concerning the posterior urethra classically arise from pelvic fractures in a multitrauma context. Its degree may range from a simple stretch to a partial or total rupture. The inicial management as well as the appearance of long term sequelae largely depend on the site of injury, its mechanism, length and type of treatment. Conclusion: Iatrogenic injuries remain the most prevalent form of urethral trauma. The diagnosis of blunt anterior urethral injuries is simple as its signs and symptoms are easily recognized. Moreover, its initial management is well described and involves the placement of a suprapubic catheter. Further action depends on the gravity and length of the injury. Regarding open injuries and penile fracture urethral injuries, primary surgical treatment gathers the approval of most of the authors. Posterior urethral distractions are serious injuries often related to unstable pelvic fractures, which must be managed by experimented surgeons in specialized hospitals. Despite the controversy of its treatment, the gold standard procedure remains delayed urethroplasty. Primary endoscopic realignment emerges as a promising approach. However, more studies are required to clearly validate its advantages

Apresentação de um caso de tuberculose primária com nódulos subcutâneos.

Trabalho de Conclusão de Curso - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde, Departamento de Pediatria, Curso de Medicina, Florianópolis, 197

Teachers' and students' views and attitudes towards a new mathematics curriculum: A case study

The education system in Portugal is in the midst of a period of intensive reform. This paper describes the findings of a qualitative case study focusing on the views and attitudes of teachers and students participating in a pilot curriculum development programme stressing active methodologies and group work, conducted by the Ministry of Education In particular it discusses their views and attitudes about mathematics, mathematics teaching and curriculum innovation. The teachers were found to struggle with a contradiction: whilst they approved the new orientations, which were seen as adequate and innovative, they complained strongly about the design and implementation of the programme Students had a generally positive attitude towards mathematics, although there were differences among them. The 7th graders were satisfied with their mathematics classes and with the new curriculum. The 10th graders did not consider the changes as significant in themselves, but expressed concern for their academic progress