2,721 research outputs found
Simpósio "Agricultura, Energia e Ambiente"
O crescimento populacional esperado para os próximos anos conduzirá à
necessidade de aumentar a produção agrícola de modo a satisfazer o aumento
da procura. Nos últimos anos tem-se assistido a uma evolução tecnológica nos
sistemas de produção que tem permitido aumentar a produtividade agrícola,
mas por vezes à custa de elevados consumos de energia e com práticas nem
sempre ambientalmente corretas.
Os desafios que se colocam atualmente são no sentido de melhorar a
conservação de recursos escassos, como o solo e a água, de aumentar a
eficiência de uso de factores de produção, de encontrar novas culturas, do
desenvolvimento da biotecnologia, da diminuição dos consumos energéticos e
de melhorar ainda mais as tecnologias associadas à produção.
A intensificação dos sistemas de produção para responder à procura, a
necessidade de encontrar fontes alternativas de energia, com a competição entre
a produção de culturas para biocombustíveis ou alimentos, a necessidade de
diminuir desperdícios, de reaproveitar a água usada, mas não consumida na
produção agrícola, ou águas residuais tratadas, e tornar a agricultura uma
prática compatível com a manutenção de uma biodiversidade ambiental, são
questões que têm de ser pensadas e discutidas por todos nós.
Deste modo, a Secção Especializada de Engenharia Rural (SEER), da
Sociedade de Ciências Agrárias de Portugal, e o Instituto de Ciências Agrárias
e Ambientais Mediterrânicas decidiram organizar o Simpósio “Agricultura,
Energia e Ambiente”, onde pretendemos que investigadores, técnicos,
produtores, e todas as pessoas interessadas nestes temas, os possam discutir
Simpósio "Agricultura, Energia e Ambiente"
O crescimento populacional esperado para os próximos anos conduzirá à
necessidade de aumentar a produção agrícola de modo a satisfazer o aumento
da procura. Nos últimos anos tem-se assistido a uma evolução tecnológica nos
sistemas de produção que tem permitido aumentar a produtividade agrícola,
mas por vezes à custa de elevados consumos de energia e com práticas nem
sempre ambientalmente corretas.
Os desafios que se colocam atualmente são no sentido de melhorar a
conservação de recursos escassos, como o solo e a água, de aumentar a
eficiência de uso de factores de produção, de encontrar novas culturas, do
desenvolvimento da biotecnologia, da diminuição dos consumos energéticos e
de melhorar ainda mais as tecnologias associadas à produção.
A intensificação dos sistemas de produção para responder à procura, a
necessidade de encontrar fontes alternativas de energia, com a competição entre
a produção de culturas para biocombustíveis ou alimentos, a necessidade de
diminuir desperdícios, de reaproveitar a água usada, mas não consumida na
produção agrícola, ou águas residuais tratadas, e tornar a agricultura uma
prática compatível com a manutenção de uma biodiversidade ambiental, são
questões que têm de ser pensadas e discutidas por todos nós.
Deste modo, a Secção Especializada de Engenharia Rural (SEER), da
Sociedade de Ciências Agrárias de Portugal, e o Instituto de Ciências Agrárias
e Ambientais Mediterrânicas decidiram organizar o Simpósio “Agricultura,
Energia e Ambiente”, onde pretendemos que investigadores, técnicos,
produtores, e todas as pessoas interessadas nestes temas, os possam discutir
Simple analytical model for the magnetophoretic separation of superparamagnetic dispersions in a uniform magnetic gradient
Magnetophoresis-the motion of magnetic particles under applied magnetic gradient-is a process of great interest in novel applications of magnetic nanoparticles and colloids. In general, there are two main different types of magnetophoresis processes: cooperative magnetophoresis (a fast process enhanced by particle-particle interactions) and noncooperative magnetophoresis (driven by the motion of individual particles in magnetic fields). In the case of noncooperative magnetophoresis, we have obtained a simple analytical solution which allows the prediction of the magnetophoresis kinetics from particle characterization data (size and magnetization). Our comparison with new experimental results shows good quantitative agreement. In addition, we show the existence of a universal curve onto which all experimental results should collapse after proper rescaling. The range of applicability of the analytical solution is discussed in light of the predictions of a magnetic aggregation model
LISA and LISA PathFinder, the endeavour to detect low frequency GWs
This is a review about LISA and its technology demonstrator, LISA PathFinder.
We first describe the conceptual problems which need to be overcome in order to
set up a working interferometric detector of low frequency Gravitational Waves
(GW), then summarise the solutions to them as currently conceived by the LISA
mission team. This will show that some of these solutions require new
technological abilities which are still under development, and which need
proper test before being fully implemented. LISA PathFinder (LPF) is the the
testbed for such technologies. The final part of the paper will address the
ideas and concepts behind the PathFinder as well as their impact on LISA.Comment: 25 pages, 21 figures, presented at the Spanish Relativity Meeting,
Mallorca September 2006. Will be published in Journal of Physics: Conference
Series, IOP. To be published in Journal of Physics: Conference Series, IO
Seedling emergence and establishment of Pinus sylvestris in the Mongolian forest-steppe ecotone
Syftet med studien är att undersöka och beskriva pedagogers uppfattningar av hur de skapar delaktighet och inflytande, i en kommuns förskoleverksamhet och organisation.Mina frågeställningar är hur pedagogerna beskriver sina möjligheter och hinder för att få och skapa delaktighet och inflytande, samt vilka inre och yttre faktorer som finns som påverkar möjligheten för delaktighet och inflytande.För att undersöka detta har jag valt en kvalitativ forskningsansats. Jag har genomfört semistrukturerade intervjuer med sju pedagoger. Det empiriska materialet har bearbetats kvalitativt i en empirinära ansats.I resultatet såg jag att ett större fokus på processkvaliteten behöver läggas och medvetenheten behöver ökas, kring den pedagogiska dokumentationens betydelse.Sammanfattningsvis behöver den undersökta kommunens förskolor en gemensam samsyn i hela systemet i ett förståelsebaserat och tolkande perspektiv som gynnar en långsiktig och hållbar utveckling.Participation and influence in the preschool, a study with teachers in one municipality.The purpose of this study is to explore and describe teacher’s perceptions of how they create participation and influence, in a municipality´s preschool and organization.My questions are how teachers describe their opportunities and barriers to get and create participation and influence, and what internal and external factors that affecting the ability of participation and influence.To examine this, I have chosen a qualitative research approach. I have conducted semi structured interviews, with seven teachers. The empirical data have been processed in a qualitative empirical closely approach.In the result, I found that a greater focus on process quality needs to be added and awareness needs to be increased, on the pedagogic documentations significances.In conclusion, needs the municipal preschools, which have been examined, get a common consensus of the entire system in a understanding based and interpretive perspective, that support a long term and sustainable development
In-flight thermal experiments for LISA pathfinder: simulating temperature noise at the inertial sensors
Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations
Small but crucial : the novel small heat shock protein Hsp21 mediates stress adaptation and virulence in Candida albicans
Peer reviewedPublisher PD
Relationship between eating behaviors and physical activity of preschoolers and their peers: a systematic review
Abstract: Objectives: Children learn by observing and imitating others, meaning that their eating behaviors and physical activity may be influenced by their peers. This paper systematically reviews how preschoolers’ eating behaviors and physical activity relate to their peers’ behaviors, and discusses avenues for future research. Methods: Six databases were searched for quantitative, peer-reviewed studies published up to July 2015 reporting on the correlates, predictors or effectiveness of peers on eating behaviors and physical activity in preschoolers. Risk of bias was independently assessed by two evaluators using the Quality Assessment Tool for Quantitative Studies. Results: Thirteen articles were included: six measured physical activity, and seven assessed eating behaviors. Four of the six physical activity studies reported that children were more active when peers were present, while large peer group size was negatively associated with physical activity in two cross-sectional studies. All nutrition interventions reported that children’s eating behaviors may be influenced by their peers. Conclusions: Although supported by weak evidence, peers appear to influence children’s eating behaviors and physical activity. However, this influence may be moderated by the number of peers, gender, age and the perceived status of the role models. Future obesity prevention interventions should consider involving peers as agents for positive eating behaviors and physical activity in preschoolers
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
The inclusive and dijet production cross-sections have been measured for jets
containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass
energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The
measurements use data corresponding to an integrated luminosity of 34 pb^-1.
The b-jets are identified using either a lifetime-based method, where secondary
decay vertices of b-hadrons in jets are reconstructed using information from
the tracking detectors, or a muon-based method where the presence of a muon is
used to identify semileptonic decays of b-hadrons inside jets. The inclusive
b-jet cross-section is measured as a function of transverse momentum in the
range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet
cross-section is measured as a function of the dijet invariant mass in the
range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets
and the angular variable chi in two dijet mass regions. The results are
compared with next-to-leading-order QCD predictions. Good agreement is observed
between the measured cross-sections and the predictions obtained using POWHEG +
Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet
cross-section. However, it does not reproduce the measured inclusive
cross-section well, particularly for central b-jets with large transverse
momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final
version published in European Physical Journal
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