11,627 research outputs found
Apparatus for inserting and removing specimens from high temperature vacuum furnaces
The apparatus comprises a high speed gate valve for isolating the interior of the furnance from an air lock chamber on the opposite side of the gate valve. The air lock chamber is provided with valve ports connected to a vacuum source, a source of inert quenching gas, and the atmosphere, respectively. Attached to the end of the air lock chamber away from the furnace is a cylindrical tube having disposed within it a rod carrying specimen pan at the end towards the furnace and having mounted at its top end an annular magnet having a diameter slightly less than the interior diameter of the tube. The top end of the tube is closed by a removeable cap. Encircling the tube in the vicinity of the magnet is a carbon steel ring which when axially moved along the tube causes the magnet to follow it and thereby controls the position of the rod and specimen pan within the tube
Automated screening of propulsion system test data by neural networks, phase 1
The evaluation of propulsion system test and flight performance data involves reviewing an extremely large volume of sensor data generated by each test. An automated system that screens large volumes of data and identifies propulsion system parameters which appear unusual or anomalous will increase the productivity of data analysis. Data analysts may then focus on a smaller subset of anomalous data for further evaluation of propulsion system tests. Such an automated data screening system would give NASA the benefit of a reduction in the manpower and time required to complete a propulsion system data evaluation. A phase 1 effort to develop a prototype data screening system is reported. Neural networks will detect anomalies based on nominal propulsion system data only. It appears that a reasonable goal for an operational system would be to screen out 95 pct. of the nominal data, leaving less than 5 pct. needing further analysis by human experts
Demand for large freighter aircraft as projected by the NASA cargo/logistics airlift system studies
The market conditions are examined up through the year 2008 to provide a preliminary assessment of the potential for and the characteristics of an advanced, all-cargo transport aircraft. Any new freighter must compete with current wide-body aircraft and their derivatives. Aircraft larger than the wide-bodies may incur economic penalties and operational problems. A lower direct operating cost is not a sufficient criterion to base a decision for the initiation of a new aircraft development or to select aircraft characteristics. Other factors of equal importance that are reviewed in this paper include considerations of the system infrastructure, the economics of the airlines, and the aircraft manufacturer return on investment. The results of the market forecast and a computer simulation show that an advanced long range aircraft with a payload between 68 to 181 tonnes (75 to 200 tons) could generate a solid foothold beginning around 1994
An outlook for cargo aircraft of the future
An assessment is provided of the future of air cargo by analyzing air cargo statistics and trends, by noting air cargo system problems and inefficiencies, by analyzing characteristics of air-eligible commodities, and by showing the promise of new technology for future cargo aircraft with significant improvements in costs and efficiency. NASA's proposed program is reviewed which would sponsor the research needed to provide for development of advanced designs by 1985
Research based criteria for the design and selection of literacy and thinking tools
Trabalho final de mestrado integrado em Medicina (Geriatria), apresentado à Faculdade de Medicina da Universidade de Coimbra.O objetivo deste artigo de revisão é resumir a literatura disponível acerca do tópico “A
depressão e o idoso” no que diz respeito a epidemiologia, fatores protetores e de risco,
diagnóstico, tratamento e prevenção. Como tal, foi feita uma pesquisa através do PubMed
considerando artigos publicados há menos de 20 anos, utilizando como palavras-chave
depressão, idoso, idade avançada, epidemiologia, prevenção, fatores de risco e tratamento, e
de seguida selecionando apenas os artigos considerados relevantes. A depressão afeta 350
milhões de pessoas e é a principal causa mundial de invalidez. Uma vez que a população
mundial envelhecida se encontra a aumentar rapidamente, é essencial um melhor
entendimento da depressão no idoso. A depressão não é uma consequência natural do
processo de envelhecimento e manifesta-se de forma diferente no idoso, através de alterações
cognitivas, somatização, alterações corporais e uma menor probabilidade de insurgência de
sintomas afetivos. O suicídio é uma possível consequência desta doença e é mais prevalente
na população envelhecida do que nas populações mais jovens. Os fatores de risco vasculares
constituem uma peça importante no desenvolvimento da depressão no idoso e como tal o seu
conhecimento deve ser aprofundado bem como o de outras vulnerabilidades biológicas
relacionadas com a idade. Os cuidados primários de saúde são essenciais na prevenção pelo
que os médicos de família devem ser educados no sentido de detetar indivíduos em risco de
desenvolver a patologia. O tratamento é tão eficaz nesta idade como na população mais jovem
e existem várias opções disponíveis, desde fármacos a psicoterapia e, em casos particulares,
terapia electroconvulsiva. Embora a literatura neste tópico esteja a aumentar, é ainda reduzida
especialmente considerando a existente acerca de outras doenças psiquiátricas menos
prevalentes nesta idade, como a demência.The aim of this review was to assess the available literature on the topic of elderly depression
in terms of epidemiology, risk and protective factors, diagnosis, treatment and prevention.
With that purpose a research was made via PubMed, with a timeline of the last 20 years, using
the keywords depression, elderly, old, late-life, aging, epidemiology, prevention, risk factors
and treatment, subsequently selecting the articles found to be relevant. Depression affects 350
million people and is the main cause of disability worldwide. As the world population is
ageing at a rapid rate, better understanding depression in old age is key. Depression is not a
normal part of the ageing process and can manifest itself differently in old age, with cognitive
alterations, somatic symptom, peripheral body changes and less likelihood to present affective
symptoms. A serious possible outcome of depression is suicide, that is more prevalent in older
populations than any other age group. Vascular risk factors play an important role in the
development of depressive disorders in this age and should be further studied, as well as other
age-associated biological vulnerabilities. Primary care services play an important role in
prevention and efforts should be made to better educate general practitioners into detecting at
risk individuals. There are various treatment options available, from drug treatments to
psychotherapy and, when needed, electroconvulsive therapy. Treatment was proven to be as
effective in this age group as in younger populations. Although literature on this topic is
growing it is still considerably low when comparing to other less prevalent psychiatric
diseases in old age, such as dementia
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