56 research outputs found
ELECTRONICAL LY RECONFIGURABLE FS S - INSPIRED TRANSMITARRAY FOR TWO DIMENS IONAL BEAMSTEERING FOR 5G ANDRADAR APPL ICATIONS AT 2 8 GHZ
In this dissertation, the author’s work on a 28 GHz transmitarray capable of antenna
beamsteering for various wireless applications, is presented. Such device allows for
the adjustment of the radiation pattern of an antenna by changing its main lobe
direction, without the need of any mechanical means.
A unit-cell based on a square-slot Frequency Selective Surface (FSS) is designed,
simulated and optimised through several full-wave simulations, using an electromagnetic
solver (CST MWS). Subsequently, the unit-cell was extended to a 10x10 array
configuration in order to enable Two-dimensional (2D) beamsteering. This work
yielded the fabrication of a prototype composed of four passive transmitarray lens,
which were experimentally tested and characterised. Finally, a novel unit-cell based
on a double square-slot intended aiming at active beamsteering was also studied
and optimised in simulation environment.
From this work, it was demonstrated that transmitarray can be seen as feasible
alternative to many traditional beamsteering techniques, such as phased antenna
arrays, while reducing the RF burden of the overall system using only a single
radiation source. This fact, allied with it’s ease of integration, reduced cost and
low-profile characteristics make transmitarrays a desirable solution for 5G and
RADAR applications, among others
Educação física na Europa : várias conceções
Artigo de RevistaUma conceção pode ser definida como uma estrutura de referência que guia a ação do professor nas suas decisões curriculares. O presente trabalho procura sistematizar as diferentes conceções de Educação Física, considerando a sua evolução histórica. Foram consultados artigos redigidos a partir de 1990 e que sintetizassem a evolução das conceções de Educação Física do passado até ao presente. A grande diversidade de conceções surge de um conjunto de diferenças
ideológicas resultantes da herança cultural de cada país ou região, bem como dos valores e crenças de cada professor, resultantes do seu processo de profissionalização. Por outro lado, a escolha de determinada conceção tem como base dar resposta às tendências sociais, repensando, desta forma, a função da disciplina no currículo escolar. Assim, atualmente, a atenção da Educação Física começa a direcionar-se para a valorização do “bem -estar” e “promoção de estilos de vida
ativos”.ABSTRACT: A conception can be defined as a reference structure that guides the action of the teacher in his curricular decisions.
Thus, the present work looks for systemize the different conceptions of Physical Education, considering its historical evolution, were consulted articles written from 1990 and that they abridged the evolution of the conceptions of Physical Education of the past until present.The great diversity of conceptions appears of a set of resultant ideological differences of the cultural
inheritance of each country or region, as well as the values and beliefs of each teacher resulting
from his professionalization process. On the other hand, the choice of determined conception has as
base to give reply to the social trends, rethink, in such a way, the structure and function of disciplines in the pertaining to school curricula. Thus, at present, the attention of the Physical Education starts to value the concepts of “welfare” and the “promotion ofactive life styles”
Geochemistry of soils and stream sediments in the NE border of the Iberian Pyrite Belt : implications to mineral exploration
Workshop comemorativo do Ano Internacional dos Solos, uma iniciativa do Laboratório Nacional
de Energia e Geologia, Comité IGCP da Unesco e Centro Ciência Viva do Lousal
Automatic control system for an oil-hydraulic actuator of a scissor lift
Lifting equipment’s have the purpose to lift goods within their safe working load and design rules specified in standards. However, some applications require additional care regarding handling the load when this care is out of the standard’s specifications. This paper presents the control and supervision system development of a scissor lift table, which should ensure, during its motion, that the vertical speed is constant. This lift table is working alongside a system for handling boxes composed by 3 entry conveyors and 1 exit conveyor. In this work, it was carried out the study of the direct and inverse kinematics to obtain the equations of position, speed and force for the oil-hydraulic actuator and the applicability of Denavit-Hartenberg’s algorithm for these equations. It was proposed a hydraulic circuit, with the selection of the main hydraulic components and the design of the oil-hydraulic actuator (a cylinder) with the magnetostrictive transducer as well. A programmable logical controller was selected, as well as the sensors and actuators for the conveyor system and a program was developed which allows to automatically control the system. The lift table’s velocity control is done by equations which define an oil flow profile of the hydraulic cylinder, which ensures a constant vertical speed of the lift table. To improve the control of the system, initial and final flow ramps were added to the equations, with reduced oil flow at the target height. It was observed that the use of Denavit-Hartenberg’s algorithm revealed to be limited, on which it was necessary to use other calculation methods to obtain the equations of speed and force. However, the proposed oil-hydraulic circuit, as well as the developed speed control, allow the control of the lift table’s position and speed.info:eu-repo/semantics/publishedVersio
Understanding male (con)tradi(c)tions through an in-depth interview study
This study aims to explore the diversity of male attitudes towards, and experiences of, sexual problems in the context of their relationships, through a qualitative approach on the historically and culturally specific patterns of change in sexual pleasures and experiences over the life course.Merck Sharp & Dohme Foundationinfo:eu-repo/semantics/publishedVersio
a transição da etapa de contenção para a de mitigação em Portugal
RESUMO - Os autores relatam a transição da etapa de retenção para a etapa de mitigação da Gripe A (H1N1), de acordo com a experiência portuguesa. Admitem que a curva epidémica da gripe poderia ser atrasada, mas não contida exactamente. A linha divisória entre os casos importados e os casos com origem em Portugal esteve na base da decisão de passar para a etapa de mitigação. --------------------------ABSTRACT – The authors report the transition from the containment phase into the mitigation one, according to the Portuguese experience. They further admit that the epidemic flu curve could be delayed, but not exactly contained. The cross line between the imported cases and those generated in Portugal supported the decision to step forward into the mitigation phase.publishersversionpublishe
SAIMI study : teeth brushing habits among immigrant children and adolescents from the Indian subcontinent in Lisbon
© 2018 Sociedade Portuguesa de Estomatologia e Medicina Dentária. Published by SPEMD. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Objectives: The number of child and adolescent immigrants from the Indian subcontinent has been increasing in Portugal. Dental caries is the most common chronic disease in these ages, and toothbrushing is the most effective prevention measure. The objective was to characterize the toothbrushing habits of immigrant children and adolescents from the Indian subcontinent, living in Lisbon. Methods: In this cross-sectional study, children and adolescents (aged 2 to 16 years) who were 1st and 2nd generation immigrants from the Indian subcontinent (Bangladesh, India and Pakistan) living in Lisbon were selected based on a chain referral sampling technique and using privileged access interviewers. Descriptive analysis of sociodemographic characteristics and toothbrushing habits and a multifactorial logistical model were performed, with toothbrushing twice a day as the dependent variable. Results: Data was obtained from 278 individuals (66% male, mean age of 7.6±3.5 years), 48% of which brushed their teeth twice a day. The probability of toothbrushing twice a day was significantly and independently associated with 1st generation immigrants and older age groups. Conclusions: In immigrant children from the Indian subcontinent, the frequency of toothbrushing twice a day is very low in pre-school ages, making it necessary to strengthen recommendations for starting toothbrushing with the eruption of the first deciduous teeth, as well as the adoption of targeted health promotion programs.Objetivos: O número de crianças e adolescentes imigrantes do subcontinente indiano tem aumentado em Portugal. A cárie dentária é a doença crónica mais frequente nestas idades, sendo a escovagem a sua mais eficaz prevenção. Pretendeu-se caracterizar os hábitos de escovagem dentária das crianças e adolescentes imigrantes do subcontinente indiano, residentes em Lisboa. Métodos: Estudo transversal com crianças e adolescentes (2 a 16 anos de idade), imigrantes de 1.ª e 2.ª geração do subcontinente indiano (Bangladesh, Índia e Paquistão) a residir em Lisboa, selecionados através de uma técnica de amostragem de propagação geométrica, usando inquiridores com acesso privilegiado à população-alvo. Foi realizada uma análise descritiva das características sociodemográficas e hábitos de escovagem e uma análise multifatorial por regressão logística, sendo a variável dependente a escovagem dentária bidiária. Resultados: Obtiveram-se dados relativos a 278 indivíduos (66% do sexo masculino, idade média de 7,6±3,5 anos), 48% dos quais escovava os dentes bidiariamente. A probabilidade de escovagem bidiária foi associada de forma significativa e independente aos imigrantes de 1.ª geração e aos grupos etários mais velhos. Conclusões: Nas crianças imigrantes do subcontinente indiano, a frequência de escovagem dentária bidiária é muito baixa em idade pré-escolar, sendo necessário reforçar as recomendações de que a escovagem se inicie com a erupção dos primeiros dentes decíduos, bem como a adoção de programas de promoção da saúde culturalmente adaptados.info:eu-repo/semantics/publishedVersio
Disfunção erétil nos cuidados de saúde primários: a sua abordagem e relação com fatores de risco cardiovasculares em doentes sem eventos cardiovasculares prévios
ABSTRACT - Introduction: Erectile dysfunction (ED) inquiry and treatment could have an important role in
cardiovascular prevention. The aims of the present study were to: (1) evaluate the association
of ED with cardiovascular risk (CVR) factors among patients with no previous cardiovascular
events; (2) assess the inquiry of ED in Portuguese primary care.
Methods: Cross-sectional study (January–March 2011) conducted in two Lisbon Primary
Healthcare Centers among men aged 18–80 years, sexually active and with no cardiac or
cerebrovascular disease. We collected data concerning CVR factors and sexual health inquiry
through interviews and clinical records and we used the International Index of Erectile Function
to evaluate ED. Logistic regression models were used to study the association between
ED and CVR factors.
Results: In a sample of 90 men (mean age 49.82 ± 15.65), 32% had ED. Hypertension prevalence
and the number of CVR factors was significantly higher among men with ED. However,
age was strongly associated with ED and, after age-adjustment, the associations found
between ED and hypertension lost their statistical significance. The majority of men evaluated
their sexual life as “very important” or “important” (98%) and affirmed that sexual
problems should be inquired by the general practitioner (93%) but only a minority were
inquired about it (14%).
Conclusion: ED is a frequent problem among men with no previous cardiovascular events
and, in our study, it was mostly associated with age. ED is still not inquired appropriately in
the primary care.RESUMO - Introdução: A abordagem e o tratamento da disfunção erétil (DE) nos cuidados de saúde
primários poderiam ter um papel importante na prevenção cardiovascular. Os objetivos
deste estudo foram: 1) estudar a relação da DE com os fatores de risco cardiovasculares
(FRCV) em indivíduos sem eventos cardiovasculares prévios; 2) avaliar a abordagem da DE
nos cuidados de saúde primários portugueses.
Métodos: Estudo transversal, exploratório, realizado em 2 centros de saúde de Lisboa,
incluindo homens com 18–80 anos de idade sexualmente ativos e sem doença cardíaca
ou cerebrovascular. Recolhemos dados relativos à abordagem da DE e dos FRCV através de
entrevistas e da consulta de processos clínicos. Avaliámos a DE através do Índice Internacional
de Função Eréctil e a associação com os FRCV através de modelos de regressão
logística.
Resultados: Numa amostra de 90 homens (média de idade 49,82 ± 15,65), 32% apresentavam
DE. A prevalência de hipertensão e o número de FRCV foi significativamente superior em
homens com DE. Contudo, a idade esteve significativamente associada à DE e, após ajuste
para a idade, a associação encontrada entre a hipertensão e a DE deixou de ser significativa.
Apesar de a maioria ter reportado que os problemas sexuais deviam ser abordados pelo
médico de família (93%), apenas uma minoria afirmou já ter sido inquirida a este respeito
(14%).
Conclusão: A DE é um problema frequente em homens sem eventos cardiovasculares prévios
e, no nosso estudo, associou-se sobretudo à idade. A DE não é suficientemente abordada nos
cuidados de saúde primários portugueses.info:eu-repo/semantics/publishedVersio
SAIMI Study - health and health care access by immigrants from the indian subcontinent in Lisbon : what recommendations for equitable and culturally adequate health care?
Copyright © Ordem dos Médicos 2015Introdução: O crescimento da população imigrante em Portugal tem sido consistente nas últimas décadas. Apesar disto, a informação sobre a saúde das populações imigrantes é escassa. Esta investigação utiliza dados recolhidos junto da população oriunda do subcontinente
indiano a residir no distrito de Lisboa para produzir recomendações para a prestação de serviços de saúde culturalmente adaptados.
Material e Métodos: Estudo transversal junto da comunidade imigrante do subcontinente indiano (Bangladesh, Índia e Paquistão) a residir em Lisboa, selecionada com base numa técnica de amostragem bola de neve e recorrendo a inquiridores com acesso privilegiado
à população-alvo. O questionário inquiriu sobre a saúde, o acesso aos cuidados de saúde, estilos de vida e atitudes perante a morte. Foi feita uma análise descritiva dos dados e uma comparação entre as três nacionalidades padronizada para a idade.
Resultados: Foram administrados questionários a 1011 indivíduos com uma taxa de adesão de 97%. A maioria dos participantes eram adultos do sexo masculino. Os imigrantes indianos relataram mais frequentemente barreiras na utilização dos serviços de saúde e tinham uma maior frequência de doenças crónicas. Os imigrantes paquistaneses tinham piores indicadores de estilos de vida.
Discussão: A população imigrante do subcontinente indiano tende a relatar mais dificuldades linguísticas no acesso aos cuidados de saúde quando comparada com outras populações imigrantes. Com base em recomendações da Organização Mundial da saúde, foi possível adaptar este conhecimento para produzir recomendações adaptadas ao contexto português.
Conclusão: Existem diversos aspetos na gestão dos serviços de saúde em Portugal que podem ser melhor adaptados à população
imigrante do subcontinente indiano.O estudo SAIMI foi financiado pela Direção-Geral da Saúde (DGS)
Overweight and obesity in Portugal: national prevalence in 2003–2005
Obesity is an endemic health problem in most developed countries, requiring serious public health attention. The first Portuguese nationwide representative survey about obesity (with objective anthropometric measurement) was undertaken from 1995 to 1998. This paper presents data coming from the second and most recent nationwide representative study of obesity, with objective measurement of weight, height, waist and hip circumferences. Data were collected between January 2003 and January 2005. The survey collected objective body mass index (BMI) values of 8116 participants aged 18-64. Main findings were: 2.4% of the sample had low weight (BMI = 30). Waist circumference measurement showed that 45.6% of the sample suffers increased cardiovascular health risks associated with high waist circumference. The overall overweight/obesity prevalence increased from 49.6% (in 1995-1998) to 53.6% (in 2003-2005). These data suggest that although obesity was identified as a public health problem one decade ago, action to reduce it does not seem to have been very effective to date. Well-defined public health intervention must be targeted to specific population groups where higher levels of obesity prevalence were found: low socioeconomic level groups and low-education level groups
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