Radiant Flux Density

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Machado, Eduardo Caruso - One of the best experts on this subject based on the ideXlab platform.

  • Um modelo matematico-fisiologico para simular o acumulo de materia seca na cultura de cana-de-açucar (Saccharum SP)
    [s.n.], 2018
    Co-Authors: Machado, Eduardo Caruso
    Abstract:

    Orientador: Hilton Silveira PintoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: No presente trabalho, desenvolveu-se um modelo matemático-fisiológico para simular o acúmulo de matéria seca na cultura de cana-de-açucar, a partir de informações metereológicas. O modelo consiste de um série de equações que descrevem quantativamente, cada uma delas, um comportamento fisiológico da planta em resposta à variação das condições ambientais. A maior parte dos parâmetros e fatores usados no desenvolvimento das equações foi obtida a partir da adaptação de resultados de pesquisas disponíveis na literatura. A estimativa da produção líquida de meteria seca, em bases diárias, foi feita pelo balanço entre Fluxos de ganho e perdas de matéria seca, representados pela fotossíntese e respiração, respectivamente. As taxas de fotossíntese total e de respiração total foram estimadas pelo produto da taxa potencial máxima por um série de fatores de ajustamentos, representando uma estimativa do efeito que cada condição ambiental e/ou fisiológica exerce sobre os processos fisiológicos considerados. Para estimar a taxa de fotossíntese diária da cultura, foram consideradas: a curva de resposta fotossíntese: radiação solar, a densidade de Fluxo de radiação solar incidente, a distribuição da radiação solar no dossel vegetativo, a reflexão da radiação solar pela superfície da cultura, área foliar, a idade da plante e da folha, a temperatura do ar e a água disponível no solo ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digitalAbstract: A physiological model was developed to simulate the dry matter accumulation in the sugar-cane, using meteorological data. The model consist of a series of equation which describe quantitatively the physiological behaviour of the plant due to the variation of the envitonmental conditions. Most of the parameters and factors used to develop the equations were obtained from research data available in the literature, and from the results obtained in the present experiment. The estimate of the daily dry matter net production was done by the balance between its gains and losses, represented by photosysthesis and respiration, respectively. The rates of gross photosysthesis and respiration were estimated as the product of their maximum potential rate by a series of limiting factors. These factors represent an estimate of the effect that each environmental and/or physiological conditions has on the physiological processes under condideration. The photosynthetic rate of the crop was calculated from the light-photosysthetic function, Radiant Flux Density, radiation distribution within the canopy, radiation refleted by the crop surface, leaf area. Age of the plant and leaf, air temperature and available soil moisture. The radiation intercepted by the crop and the radiation distribution within the canopy were determined experimentally by the balance of the global and near infra-red radiation mede in a sugar-cane plantation, located in the Experimental Station of Piracicaba of the Instituto Agronomico ...Note: The complete abstract is available with the full electronic digital thesis or dissertationsMestradoMestre em Ciências Biológica

Pereira Netto - One of the best experts on this subject based on the ideXlab platform.

  • Comportamento fisio-ecologico de plantas de kudzu (Pueraria spp.) : efeito da temperatura e da deficiencia hidrica sobre a assimilação do nitrato e balanço hidrico na planta
    2018
    Co-Authors: Pereira Netto
    Abstract:

    Orientador: Hilton Silveira PintoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Os efeitos da temperatura e da deficiência hídrica sobre a atividade da redutase de nitrato (E.C.1.6.6.1), in vivo, resistência foliar à difusão de vapor de água, temperatura foliar e conteúdo relativo de água da folha foram avaliados em dois ambientes. Em casa de vegetação, utilizando-se Pueraria phaseoloides, a deficiência hídrica foi induzida através da suspensão da irrigação e no campo, plantas de Pueraria lobata cresceram sob efeito das flutuações na temperatura do ar e na disponibilidade de água no solo naturalmente verificadas no local. Medidas da densidade do Fluxo de radiação solar global instantânea, temperatura e umidade relativa do ar e conteúdo de água do solo foram realizadas e a densidade do Fluxo de radiação solar global diária e o défice de pressão de vapor entre a folha e o ar calculados, visando o monitoramento das condições micro-climáticas nas proximidades das plantas. Foram ainda padronizadas neste trabalho as condições mais adequadas para o ensaio da redutase de nitrato em tecidos foliares. ...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digitalAbstract: The effects of air temperature and water déficit on nitrate reductase activity (E.C.1.6.6.1),leaf diffusion resistance, leaf temperature and leaf relative water content were evaluated in two different environmental conditions. In the greenhouse, using Pueraria phaseoloides, the water deficit was induced by suspending the irrigation and in the field, Pueraria lobata plants were naturally submitted to both fluctuating air temperature and soil water availability. Measurements of the instantaneous Radiant Flux Density, air temperature, relative humidity and soil water content were taken.Daily Radiant Flux Density and the leaf-air vapor pressure deficit were calculated for the characterization of the microclimate conditions of the plant surroundings. Furthermore, more appropriated conditions were standarized for nitrate reductase assay in vivo in foliar tissue. In the field experiments, a considerable influence of air temperature on nitrate assimilation was found/ the greatest nitrate reductase acativity was observed between 28 and 29oC and a considerable decrease in temperatures above 33 and below 23oC.The increase in leaf diffusion resistance from 1,0 to 1,8 sec.cm-1 was associated to the increase in air temperature from 21 to 36oC. The increase in leaf diffusion resistance from 0,9 to 1,8 sec.cm ¿1 was related to water depletion of field capacity from 71 to 50%. ...Note: The complete abstract is available with the full electronic digital thesis or dissertationsMestradoBiologia VegetalMestre em Ciências Biológica

A S Bova - One of the best experts on this subject based on the ideXlab platform.

  • Radiant Flux Density energy Density and fuel consumption in mixed oak forest surface fires
    International Journal of Wildland Fire, 2012
    Co-Authors: R L Kremens, Matthew B Dickinson, A S Bova
    Abstract:

    Closing the wildland fire heat budget involves characterising the heat source and energy dissipation across the range of variability in fuels and fire behaviour. Meeting this challenge will lay the foundation for predicting direct ecological effects of fires and fire–atmosphere coupling. In this paper, we focus on the relationships between the fire radiation field, as measured from the zenith, fuel consumption and the behaviour of spreading flame fronts. Experiments were conducted in 8 × 8-m outdoor plots using preconditioned wildland fuels characteristic of mixed-oak forests of the eastern United States. Using dual-band radiometers with a field of view of ~18.5 m2 at a height of 4.2 m, we found a near-linear increase in fire radiative energy Density over a range of fuel consumption between 0.15 and 3.25 kg m–2. Using an integrated heat budget, we estimate that the fraction of total theoretical combustion energy Density radiated from the plot averaged 0.17, the fraction of latent energy transported in the plume averaged 0.08, and the fraction accounted for by the combination of fire convective energy transport and soil heating averaged 0.72. Future work will require, at minimum, instantaneous and time-integrated estimates of energy transported by radiation, convection and soil heating across a range of fuels.

Berko Sierau - One of the best experts on this subject based on the ideXlab platform.

  • spectral absorption properties of atmospheric aerosols
    Atmospheric Chemistry and Physics, 2007
    Co-Authors: Robert Bergstrom, P K Quinn, Peter Pilewskie, Jens Redemann, Tami C Bond, Philip B. Russell, Berko Sierau
    Abstract:

    We have determined the solar spectral absorption optical depth of atmospheric aerosols for specific case studies during several field programs (three cases have been reported previously; two are new results). We combined airborne measurements of the solar net Radiant Flux Density and the aerosol optical depth with a detailed radiative transfer model for all but one of the cases. The field programs (SAFARI 2000, ACE Asia, PRIDE, TARFOX, INTEX-A) contained aerosols representing the major absorbing aerosol types: pollution, biomass burning, desert dust and mixtures. In all cases the spectral absorption optical depth decreases with wavelength and can be approximated with a power-law wavelength dependence (Absorption Angstrom Exponent or AAE). We compare our results with other recent spectral absorption measurements and attempt to briefly summarize the state of knowledge of aerosol absorption spectra in the atmosphere. We discuss the limitations in using the AAE for calculating the solar absorption. We also discuss the resulting spectral single scattering albedo for these cases.

  • under a Creative Commons License. Atmospheric Chemistry and Physics Spectral absorption properties of atmospheric aerosols
    2007
    Co-Authors: R. W. Bergstrom, P K Quinn, Peter Pilewskie, Jens Redemann, Tami C Bond, Philip B. Russell, Berko Sierau
    Abstract:

    Abstract. We have determined the solar spectral absorption optical depth of atmospheric aerosols for specific case studies during several field programs (three cases have been reported previously; two are new results). We combined airborne measurements of the solar net Radiant Flux Density and the aerosol optical depth with a detailed radiative transfer model for all but one of the cases. The field programs (SAFARI 2000, ACE Asia, PRIDE, TARFOX, INTEX-A) contained aerosols representing the major absorbing aerosol types: pollution, biomass burning, desert dust and mixtures. In all cases the spectral absorption optical depth decreases with wavelength and can be approximated with a power-law wavelength dependence (Absorption Angstrom Exponent or AAE). We compare our results with other recent spectral absorption measurements and attempt to briefly summarize the state of knowledge of aerosol absorption spectra in the atmosphere. We discuss the limitations in using the AAE for calculating the solar absorption. We also discuss the resulting spectral single scattering albedo for these cases.

Vytlačilová Jitka - One of the best experts on this subject based on the ideXlab platform.

  • Usage of the annelid Tubifex tubifex Müll. as a model organism for biological activity assessment
    Univerzita Karlova Přírodovědecká fakulta, 2010
    Co-Authors: Vytlačilová Jitka
    Abstract:

    The aim of the presented doctoral thesis was to use the sludge worm Tubifex tubifex as a model for biological activity testing. In the presented study, the Tubifex worm was used to evaluate photosensibilisation, i.e. sensibilisation of an organism towards UVA radiation (365 nm; Radiant Flux Density of 350 μW/cm2) after contact with certain substances. The tested substances included proven photosensibilizing agents - rose bengal, khellin and xanthotoxin; isolated natural substances - thiophene polyacetylene umbelliferon, scopoline, and scopoletine; synthetic compounds - salicylanilides and thiosalicylanilides; and penicillin drugs Augmentin and Ospamox and their active substance standard amoxicillin. The final evaluation of photosensibilizing properties of the substances was carried out according to the Commission Directive 2000/33/EC PHOTOTOXICITY - IN VITRO 3T3 NRU PHOTOTOXICITY TEST. The test was performed in 24-well plates where one set of plates with the photosensibilizing agent was irradiated and the second set was placed in an incubator (20±2řC) as a dark control without any light presence for the whole period of the experiment. The plates were evaluated immediately after the given period of irradiation (15, 30, 45, 60, 120, and 240 minutes). Mortality and percentual number of damaged...Záměrem předložené disertační práce bylo využití kroužkovce Tubifex tubifex jako modelu pro testování biologické aktivity. Nítěnka byla v této studii použita pro hodnocení fotosenzibilizace, tj. zcitlivění organismu vůči UVA záření (365 nm; hustota zářivého toku 350 μW/cm2) po styku s určitými látkami. Testované látky zahrnovaly jednak prokázané fotosenzibilizátory: bengálskou červeň khelin a xantotoxin. Dále přírodní izolované látky - thiofenový polyyn, umbelliferon, skopolin, skopoletin. Zástupce syntetických látek - salicylanilidy a thiosalicylanilidy a léčiva penicilinového typu Augmentin, Ospamox a jejich standard účinné látky amoxicilin. Závěrečné zhodnocení fotosenzibilizačních vlastností látek bylo provedeno dle Směrnice komise 2000/33/ES pro FOTOTOXICITY - ZKOUŠKY FOTOTOXICITY 3T3 NRU IN VITRO. Test probíhal ve 24jamkových destičkách. Kdy jedna sada destiček s fotosenzibilizátorem byla ozařována a druhá sada byla po celou dobu experimentu umístěna v termostatu (20±2řC) bez přítomnosti světla jako temnostní kontrola. Vyhodnocení probíhalo ihned po zvolené době ozařování (15, 30, 45, 60, 120, 240 min). Jako endpointy byla navržena mortalita a procento poškozených jedinců. Mezi prokázanými fotosenzibilizátory byl dosažen nejvyšší PIF faktor (5,72) u bengálské červeně po 30 min ozařování a při...Katedra ekologieDepartment of EcologyFaculty of SciencePřírodovědecká fakult

  • Usage of the annelid Tubifex tubifex Müll. as a model organism for biological activity assessment
    2010
    Co-Authors: Vytlačilová Jitka
    Abstract:

    The aim of the presented doctoral thesis was to use the sludge worm Tubifex tubifex as a model for biological activity testing. In the presented study, the Tubifex worm was used to evaluate photosensibilisation, i.e. sensibilisation of an organism towards UVA radiation (365 nm; Radiant Flux Density of 350 μW/cm2) after contact with certain substances. The tested substances included proven photosensibilizing agents - rose bengal, khellin and xanthotoxin; isolated natural substances - thiophene polyacetylene umbelliferon, scopoline, and scopoletine; synthetic compounds - salicylanilides and thiosalicylanilides; and penicillin drugs Augmentin and Ospamox and their active substance standard amoxicillin. The final evaluation of photosensibilizing properties of the substances was carried out according to the Commission Directive 2000/33/EC PHOTOTOXICITY - IN VITRO 3T3 NRU PHOTOTOXICITY TEST. The test was performed in 24-well plates where one set of plates with the photosensibilizing agent was irradiated and the second set was placed in an incubator (20±2řC) as a dark control without any light presence for the whole period of the experiment. The plates were evaluated immediately after the given period of irradiation (15, 30, 45, 60, 120, and 240 minutes). Mortality and percentual number of damaged individuals were..

  • Usage of the annelid Tubifex tubifex Müll. as a model organism for biological activity assessment
    2010
    Co-Authors: Vytlačilová Jitka
    Abstract:

    The aim of the presented doctoral thesis was to use the sludge worm Tubifex tubifex as a model for biological activity testing. In the presented study, the Tubifex worm was used to evaluate photosensibilisation, i.e. sensibilisation of an organism towards UVA radiation (365 nm; Radiant Flux Density of 350 μW/cm2) after contact with certain substances. The tested substances included proven photosensibilizing agents - rose bengal, khellin and xanthotoxin; isolated natural substances - thiophene polyacetylene umbelliferon, scopoline, and scopoletine; synthetic compounds - salicylanilides and thiosalicylanilides; and penicillin drugs Augmentin and Ospamox and their active substance standard amoxicillin. The final evaluation of photosensibilizing properties of the substances was carried out according to the Commission Directive 2000/33/EC PHOTOTOXICITY - IN VITRO 3T3 NRU PHOTOTOXICITY TEST. The test was performed in 24-well plates where one set of plates with the photosensibilizing agent was irradiated and the second set was placed in an incubator (20±2řC) as a dark control without any light presence for the whole period of the experiment. The plates were evaluated immediately after the given period of irradiation (15, 30, 45, 60, 120, and 240 minutes). Mortality and percentual number of damaged..

  • Usage of the annelid Tubifex tubifex Müll. as a model organism for biological activity assessment
    Univerzita Karlova Přírodovědecká fakulta, 2010
    Co-Authors: Vytlačilová Jitka
    Abstract:

    The aim of the presented doctoral thesis was to use the sludge worm Tubifex tubifex as a model for biological activity testing. In the presented study, the Tubifex worm was used to evaluate photosensibilisation, i.e. sensibilisation of an organism towards UVA radiation (365 nm; Radiant Flux Density of 350 μW/cm2) after contact with certain substances. The tested substances included proven photosensibilizing agents - rose bengal, khellin and xanthotoxin; isolated natural substances - thiophene polyacetylene umbelliferon, scopoline, and scopoletine; synthetic compounds - salicylanilides and thiosalicylanilides; and penicillin drugs Augmentin and Ospamox and their active substance standard amoxicillin. The final evaluation of photosensibilizing properties of the substances was carried out according to the Commission Directive 2000/33/EC PHOTOTOXICITY - IN VITRO 3T3 NRU PHOTOTOXICITY TEST. The test was performed in 24-well plates where one set of plates with the photosensibilizing agent was irradiated and the second set was placed in an incubator (20±2řC) as a dark control without any light presence for the whole period of the experiment. The plates were evaluated immediately after the given period of irradiation (15, 30, 45, 60, 120, and 240 minutes). Mortality and percentual number of damaged individuals were...Záměrem předložené disertační práce bylo využití kroužkovce Tubifex tubifex jako modelu pro testování biologické aktivity. Nítěnka byla v této studii použita pro hodnocení fotosenzibilizace, tj. zcitlivění organismu vůči UVA záření (365 nm; hustota zářivého toku 350 μW/cm2) po styku s určitými látkami. Testované látky zahrnovaly jednak prokázané fotosenzibilizátory: bengálskou červeň khelin a xantotoxin. Dále přírodní izolované látky - thiofenový polyyn, umbelliferon, skopolin, skopoletin. Zástupce syntetických látek - salicylanilidy a thiosalicylanilidy a léčiva penicilinového typu Augmentin, Ospamox a jejich standard účinné látky amoxicilin. Závěrečné zhodnocení fotosenzibilizačních vlastností látek bylo provedeno dle Směrnice komise 2000/33/ES pro FOTOTOXICITY - ZKOUŠKY FOTOTOXICITY 3T3 NRU IN VITRO. Test probíhal ve 24jamkových destičkách. Kdy jedna sada destiček s fotosenzibilizátorem byla ozařována a druhá sada byla po celou dobu experimentu umístěna v termostatu (20±2řC) bez přítomnosti světla jako temnostní kontrola. Vyhodnocení probíhalo ihned po zvolené době ozařování (15, 30, 45, 60, 120, 240 min). Jako endpointy byla navržena mortalita a procento poškozených jedinců. Mezi prokázanými fotosenzibilizátory byl dosažen nejvyšší PIF faktor (5,72) u bengálské červeně po 30 min ozařování a při...Institute for Environmental StudiesÚstav pro životní prostředíFaculty of SciencePřírodovědecká fakult