629 research outputs found
Equações de estimativa da radiação solar fotosinteticamente ativa para diferentes coberturas de céu
O objetivo do trabalho foi propor equações de estimativa da radiação solar fotosinteticamente ativa em função da radiação solar global para diferentes coberturas de céu. A base de dados de irradiâncias global e fotossinteticamente ativa de 2004 foi cedida pelo Laboratório de Radiometria Solar de Botucatu-UNESP. As equações de estimativa foram obtidas por meio de regressão linear para 4 condições diferenciadas: todas as condições de cobertura de céu; cobertura de céu nublada; cobertura de céu parcialmente nublada e; cobertura de céu aberto. A verificação de desempenho das equações de estimativa foi realizada a partir da análise do coeficiente de determinação R2. Os resultados mostram percentuais diferenciados da radiação solar fotossinteticamente ativa em função da radiação solar global para as diferentes coberturas de céu: 46,25%para todas as condições de cobertura de céu; 50,06% para cobertura de céu nublado; 47,05% para cobertura de céu parcialmente nublado e; 45,64% para coberutra de céu aberto.The objective was to propose estimating equations of photosynthetically active solar radiation due to solar radiation for different sky covers. The global irradiance database and photosynthetically active 2004 was provided by the Solar Radiometry Laboratory Botucatu-UNESP. The estimating equations were obtained by linear regression to four different conditions: all sky coverage conditions; cloudy sky coverage; sky coverage and partly cloudy; open coverage. The performance verification of estimating equations was performed from the analysis of the R2 determination coefficient. The results show different percentage of photosynthetically active solar radiation due to solar radiation for different sky covers: 46.25% for all sky coverage conditions; 50.06% for cloudy sky coverage; 47.05% partly cloudy sky and coverage; 45.64% for open coverage.Tema 11: Radiación solar y clima.Facultad de Arquitectura y Urbanism
Equações de estimativa da radiação solar fotosinteticamente ativa para diferentes coberturas de céu
O objetivo do trabalho foi propor equações de estimativa da radiação solar fotosinteticamente ativa em função da radiação solar global para diferentes coberturas de céu. A base de dados de irradiâncias global e fotossinteticamente ativa de 2004 foi cedida pelo Laboratório de Radiometria Solar de Botucatu-UNESP. As equações de estimativa foram obtidas por meio de regressão linear para 4 condições diferenciadas: todas as condições de cobertura de céu; cobertura de céu nublada; cobertura de céu parcialmente nublada e; cobertura de céu aberto. A verificação de desempenho das equações de estimativa foi realizada a partir da análise do coeficiente de determinação R2. Os resultados mostram percentuais diferenciados da radiação solar fotossinteticamente ativa em função da radiação solar global para as diferentes coberturas de céu: 46,25%para todas as condições de cobertura de céu; 50,06% para cobertura de céu nublado; 47,05% para cobertura de céu parcialmente nublado e; 45,64% para coberutra de céu aberto.The objective was to propose estimating equations of photosynthetically active solar radiation due to solar radiation for different sky covers. The global irradiance database and photosynthetically active 2004 was provided by the Solar Radiometry Laboratory Botucatu-UNESP. The estimating equations were obtained by linear regression to four different conditions: all sky coverage conditions; cloudy sky coverage; sky coverage and partly cloudy; open coverage. The performance verification of estimating equations was performed from the analysis of the R2 determination coefficient. The results show different percentage of photosynthetically active solar radiation due to solar radiation for different sky covers: 46.25% for all sky coverage conditions; 50.06% for cloudy sky coverage; 47.05% partly cloudy sky and coverage; 45.64% for open coverage.Tema 11: Radiación solar y clima.Facultad de Arquitectura y Urbanism
Equações de estimativa da radiação solar fotosinteticamente ativa para diferentes coberturas de céu
O objetivo do trabalho foi propor equações de estimativa da radiação solar fotosinteticamente ativa em função da radiação solar global para diferentes coberturas de céu. A base de dados de irradiâncias global e fotossinteticamente ativa de 2004 foi cedida pelo Laboratório de Radiometria Solar de Botucatu-UNESP. As equações de estimativa foram obtidas por meio de regressão linear para 4 condições diferenciadas: todas as condições de cobertura de céu; cobertura de céu nublada; cobertura de céu parcialmente nublada e; cobertura de céu aberto. A verificação de desempenho das equações de estimativa foi realizada a partir da análise do coeficiente de determinação R2. Os resultados mostram percentuais diferenciados da radiação solar fotossinteticamente ativa em função da radiação solar global para as diferentes coberturas de céu: 46,25%para todas as condições de cobertura de céu; 50,06% para cobertura de céu nublado; 47,05% para cobertura de céu parcialmente nublado e; 45,64% para coberutra de céu aberto.The objective was to propose estimating equations of photosynthetically active solar radiation due to solar radiation for different sky covers. The global irradiance database and photosynthetically active 2004 was provided by the Solar Radiometry Laboratory Botucatu-UNESP. The estimating equations were obtained by linear regression to four different conditions: all sky coverage conditions; cloudy sky coverage; sky coverage and partly cloudy; open coverage. The performance verification of estimating equations was performed from the analysis of the R2 determination coefficient. The results show different percentage of photosynthetically active solar radiation due to solar radiation for different sky covers: 46.25% for all sky coverage conditions; 50.06% for cloudy sky coverage; 47.05% partly cloudy sky and coverage; 45.64% for open coverage.Tema 11: Radiación solar y clima.Facultad de Arquitectura y Urbanism
Gravitational Waves From Known Pulsars: Results From The Initial Detector Era
We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data
Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of
continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a
fully coherent search, based on matched filtering, which uses the position and rotational parameters
obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto-
noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch
between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have
been developed, allowing a fully coherent search for gravitational waves from known pulsars over a
fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of
11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial
outliers, further studies show no significant evidence for the presence of a gravitational wave signal.
Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of
the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for
the first time. For an additional 3 targets, the median upper limit across the search bands is below the
spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried
out so far
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