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Статті в журналах з теми "Flux visibles"

Автор: Grafiati

Опубліковано: 20 січня 2023

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1

Manzagol, Claude. "Portée géographique des investissements étrangers." Cahiers de géographie du Québec 17, no. 40 (April 12, 2005): 35–49. http://dx.doi.org/10.7202/021104ar.

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Si les géographes ont depuis longtemps reconnu l'importance des flux de capital qui sous-tendent la circulation des biens visibles, ils ont accordé peu d'attention aux mouvements internationaux de l'argent dont l'impact était difficile à mesurer. La période actuelle est marquée par la montée rapide, dans la plupart des pays, des investissements étrangers, essentiellement sous forme d'investissements directs. À la lumière de statistiques et d'ouvrages récents, l'auteur montre comment, outre l'accroissement de l'écart entre pays développés et Tiers Monde, ils modifient les réseaux de flux (biens, personnes, information, innovation) et les structures des pays d'accueil. Ils contribuent en outre à accentuer les disparités régionales, tant il est vrai que leur comportement s'identifie à travers des schémas spatiaux originaux. Certes, l'investissement américain au Canada, qui fournit les exemples les plus démonstratifs, constitue un cas limite. Néanmoins, la montée des entreprises multi-nationales engendre un nouveau système industriel caractérisé par un changement d'échelle de l'appareil de production et une modification radicale des structures et des stratégies d'entreprises.

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2

GONDRET, F. "La lipogenèse chez le lapin. Importance pour le contrôle de la teneur en lipides de la viande." INRAE Productions Animales 12, no. 4 (September 1, 1999): 301–9. http://dx.doi.org/10.20870/productions-animales.1999.12.4.3891.

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La teneur en lipides d’un tissu est la résultante de plusieurs flux métaboliques (dépôt, synthèse, utilisation). Cet article présente les principales caractéristiques de la synthèse des lipides chez le lapin, dans le muscle comparativement aux tissus adipeux visibles et au foie. Le potentiel de synthèse de novo exprimé par le muscle augmente avec l’âge de l’animal, en parallèle à l’accumulation des triglycérides dans les adipocytes intramusculaires. L’activité des enzymes qui fournissent le NADPH nécessaire à la synthèse des acides gras est réduite si l’animal est soumis à une restriction alimentaire en fin d’engraissement, et ceci en parallèle avec une baisse de la teneur en lipides des muscles. A valeur énergétique égale, la nature des acides gras présents dans le régime alimentaire est sans incidence sur l’activité des enzymes de la lipogenèse, mais peut moduler la quantité et la nature des lipides intramusculaires. Des études ultérieures devront être conduites pour évaluer l’importance respective des différentes voies métaboliques dans la détermination de la teneur finale en lipides des muscles.

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3

Lardon, Sylvie. "Les trois vi-e-s des territoires ruraux : voyage en France ou ailleurs." Revue Organisations & territoires 29, no. 1 (May 12, 2020): 149–63. http://dx.doi.org/10.1522/revueot.v29n1.1134.

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Les territoires ruraux changent : ils nouent de nouvelles relations avec le monde urbain. La planètes’urbanise : elle est le siège de nombreux flux. Ces dynamiques, qui s’étendent sur de larges espaces, occultent celles qui se déroulent à proximité, à faible densité, dans les territoires où pourtant on assiste à un foisonnement d’initiatives. Or, ce sont des territoires vivants qui transforment le monde en articulant l’urbain et le rural, en assumant une solidarité réciproque, en dépassant les limites et les frontières. Pour accompagner ces dynamiques de changement, l’ingénierie territoriale se doit de favoriser l’interterritorialité, l’intégration des échelles et des mondes ainsi que la reconnaissance des innovations sociales et territoriales. Plus encore, elle doit impliquer l’ensemble des acteurs qui sont partie prenante pour donner vie aux territoires en se construisant une vision partagée du territoire et en mettant en oeuvre des actions collectives, en les ancrant dans le territoire et en les rendant visibles et sensibles. Ce cadre conceptuel d’une ingénierie territoriale pour, par et avec les territoires ruraux est issu d’une recherche partenariale en cours avec le territoire du Grand Clermont et du parc naturel régional Livradois-Forez, en région Auvergne- Rhône-Alpes, en France, qui « invente les territoires de demain » autour de son projet alimentaire territorial. Il y a là de nouvelles pistes à explorer qui remettent en cause les procédés traditionnels de production scientifique et de construction de l’action. La rigueur des itinéraires méthodologiques construits et la diversité assumée des dispositifs permettent de monter en généricité. L’imagination valorise cette diversité et produit le futur des territoires.

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4

Megessier, C. "The visual and infrared flux calibrations." Symposium - International Astronomical Union 189 (1997): 61–66. http://dx.doi.org/10.1017/s007418090011650x.

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We present a critical review of the available visible and near infrared flux calibrations. In the visible, the accuracy and the good consistency of three independent determinations of Vega monochromatic flux allow one to recommend with confidence f5556-Vega = 3.46 10−11Wm−2nm−1 within 0.7%. In the near infrared, the possible flux excess of Vega, as compared to that derived from the atmosphere models fitting the visible, does not allow such a good accuracy. The agreement between the calibrations, either from a comparison of Vega to blackbodies or from solar analog stars, would question the calibrations relying on models. More work is necessary to conclude with confidence and then to reduce the uncertainty on the near infrared calibrations.

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5

Troshchynska, Yana, Roman Bleha, Lenka Kumbarová, Marcela Sluková, Andrej Sinica, and Jiří Štětina. "Discrimination of flax cultivars based on visible diffusion reflectance spectra and colour parameters of whole seeds." Czech Journal of Food Sciences 37, No. 3 (July 3, 2019): 199–204. http://dx.doi.org/10.17221/202/2018-cjfs.

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Discrimination of yellow and brown seeded flax cultivars was made based on visible (Vis) diffusion reflectance spectra of whole seeds. Hierarchy cluster analysis (HCA) and principal component analysis (PCA) were used for the discrimination. Multivariate analyses of Vis spectra led to satisfactory discrimination of all flax cultivars of this study. The CIE L*a*b* colour parameters were calculated from the diffusion reflectance Vis spectra. The values of L* were in the range of 48.8–53.6 and 62.6–66.0% for brown and yellow seeded cultivars, respectively. Chromatic parameters a* and b* were in the range of 2.8–4.9 and 7.9–16.4%, respectively. A strong linear correlation (R<sub>2</sub> = 0.9712) was found between a* and b* parameters for all the flaxseed samples. The L* and a* parameters were sufficient for HCA clustering of the individual flax cultivars.

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6

Subedi, Bimal, Sameer Nepal, and Ocean Shrestha. "Comparison of Relative Flux Density of Procyon in Visible Band." Nepal Journal of Science and Technology 20, no. 1 (December 31, 2021): 82–90. http://dx.doi.org/10.3126/njst.v20i1.43357.

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We present the photometric analysis of Procyon in FITS format using Aladin 9.0 by studying the luminous flux collected by a 16 inch Meade LX200GPS Schmidt-Cassegrain telescope placed at B.P. Koirala National Observa¬tory, Nagarkot, Nepal on April 18, 2017. The maximum and minimum diameters along the maximum and minimum flux regions are constructed. A graph is plotted using a Python custom program for the relative flux density along the two diameters. The flux density varies from the region of extremities of the diameters constructed from 0.25 to a peak of 248.50 in the relative unit. A significant bulging towards the north-eastern portion of Procyon is observed. While moving from the region of maximum flux towards the edge of the north-eastern section, we noticed the bulge prominently. The south-western portion and the other two directions do not show much variation. A possible explanation of the result is discussed.

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7

Lei, Yu, Fang Fang Fu, Li Zheng, Zhi Qiang Wang, Xin Zhao, and Hai Lin. "Absolute Luminous Flux and Quantum Yield of Sm³⁺-Doped Cadmium-Aluminum-Silicate Glasses under the Pumping of Blue Light Emitting Diode." Applied Mechanics and Materials 275-277 (January 2013): 1974–77. http://dx.doi.org/10.4028/www.scientific.net/amm.275-277.1974.

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Absolute luminous flux and quantum yield for multichannel transition emissions have been determined in samarium ion (Sm3+)-doped cadmium-aluminum-silicate (CAS) glasses under the pumping of blue light emitting diode (LED) using an integrating sphere of 30 cm diameter, which connected to a CCD detector with a 400 μm-core optical fiber. The radiant flux and luminous flux for the visible transition emissions (550–750 nm) of Sm3+under the blue LED excitation were solved to be 123 μW and 32 mlm, respectively, which occupied 1.51% and 7.16% of the whole. The total quantum yield of the visible fluorescence of Sm3+has been calculated to be 2.52%. Investigation on optical radiation parameters for multichannel visible transition emissions of Sm3+in CAS glasses provides a reference in developing luminescence and display materials.

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8

Kruk, Jeffrey W. "Review of the ultraviolet flux calibration." Symposium - International Astronomical Union 189 (1997): 67–72. http://dx.doi.org/10.1017/s0074180900116511.

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The practical difficulties in performing laboratory calibrations of instruments at ultraviolet wavelengths are considerably greater than at visible wavelengths, and the concommitant uncertainties are greater as well. In recent years theoretical models of white dwarf atmospheres have been adopted as UV flux standards, with impressive results. In this review, I will discuss the methodology of laboratory flux calibrations in the UV, the internal consistency and potential shortcomings of calibrations based on white dwarf model atmospheres, recent laboratory results, and future prospects.

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9

Roibu, Anca, Rishi Bharadwaj Morthala, M. Enis Leblebici, Dorota Koziej, Tom Van Gerven, and Simon Kuhn. "Design and characterization of visible-light LED sources for microstructured photoreactors." Reaction Chemistry & Engineering 3, no. 6 (2018): 849–65. http://dx.doi.org/10.1039/c8re00165k.

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10

Maruyama, Yuki, Chihiro Izawa, and Tomoaki Watanabe. "Synthesis of by the Flux Method." ISRN Materials Science 2012 (September 26, 2012): 1–5. http://dx.doi.org/10.5402/2012/170362.

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has been successfully synthesized using Bi2O3–B2O3 eutectic flux. In particular, we succeeded in synthesizing a low-temperature-phase crystal (α-) at 1073 K as well as high-temperature-phase crystal (β-). The morphology of α- and β- particles prepared by the flux method is a euhedral crystal. In contrast, the morphology of particles prepared by solid state reaction differs: α- is aggregated and β- is necked. Ultraviolet-visible diffuse reflectance spectra indicate that the absorption edge is at a longer wavelength for β- than for α- with β- absorbing light of wavelengths up to nearly 400 nm.

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11

Bohlin, Ralph C. "CALSPEC: HST Spectrophotometric Standards at 0.115 to 32 μm with a 1% Accuracy Goal". Proceedings of the International Astronomical Union 14, A30 (серпень 2018): 449–53. http://dx.doi.org/10.1017/s1743921319005064.

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AbstractThe flux distributions of spectrophotometric standard stars were initially derived from the comparison of stars to laboratory sources of known flux but are now based on calculated model atmospheres. For example, pure hydrogen white dwarf (WD) models provide the basis for the HST CALSPEC archive of flux standards. There is good evidence that relative fluxes from the visible to the near-IR wavelength of ∼2.5 μm are currently accurate to ∼1% for the primary reference standards.

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12

Zorec, J., D. Ballereau, and J. Chauville. "Continuum Flux Excess in Be Stars Determined from Spectral Lines." International Astronomical Union Colloquium 175 (2000): 502–5. http://dx.doi.org/10.1017/s0252921100056360.

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AbstractWe study the continuum flux excess at λ4471 by comparing the observed He I λ4471 line profiles with non-LTE model line profiles. Assuming that emission of the Hγ line is formed nearly in the same regions of the circumstellar envelope as those where the visible continuum flux excess rises, we estimate the continuum opacity needed to account for the veiling of the He I λ4471 line. The flux excess so derived is then studied as a function of the stellar aspect angle in an attempt to determine the degree of incidence of the envelope geometry near the central star on the continuum flux of Be stars.

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13

Giampapa, Mark S. "The Photometric Variability of Solar-Type Stars." Proceedings of the International Astronomical Union 11, A29A (August 2015): 365–71. http://dx.doi.org/10.1017/s174392131600329x.

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AbstractThe joint variability of chromospheric emission with the integrated flux in the Kepler visible band for the Sun as a star is examined. No correlation between our Ca II K line parameter and the Kepler passband is seen, suggesting that visible-band variability in solar-like stars is mostly independent of solar-like chromospheric activity. However, the K-line parameter time series and the total solar flux in the infrared K band appear weakly correlated, reflecting the wavelength dependence of the relationship between magnetic activity and broadband variability. We then apply a schematic, three-component model as a framework for the discussion of stellar photometric variability as observed by Kepler. The model confirms that spots tend to dominate stellar photometric variability in the visible though interesting cases do emerge where the facular disk coverage may become important in determining the amplitude of broadband variability.

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14

Booth, A. J. "The stellar temperature scale from angular diameters and flux distributions." Symposium - International Astronomical Union 189 (1997): 147–52. http://dx.doi.org/10.1017/s0074180900116626.

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The current situation for the measurement of effective temperatures from interferometrically determined angular diameters and spectrophometry in the UV, visible and IR is considered. Accuracies and reliabilities of the resulting temperatures are assessed and coverage of stellar types is discussed.

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15

Goukenleuque, Cédric, Bruno Bézard, and Emmanuel Lellouch. "Radiative equilibrium models of “hot Jupiters”." Symposium - International Astronomical Union 202 (2004): 277–79. http://dx.doi.org/10.1017/s0074180900218056.

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We present an extension of our equilibrium model, initially applied to 51 Peg b (Goukenleuque et al. 2000), to other irradiated extrasolar planets with different orbital distances (up to 1 AU). The model yields the mean atmospheric thermal structure and predicts the reflected spectral flux as well as the thermal flux emerging from such planets, in the visible and in the infrared wavelength ranges.

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16

PARWANI, RAJESH R. "SPIN POLARIZATION BY EXTERNAL MAGNETIC FIELDS, AHARONOV-BOHM FLUX STRINGS, AND CHIRAL SYMMETRY BREAKING IN QED3." International Journal of Modern Physics A 11, no. 10 (April 20, 1996): 1715–31. http://dx.doi.org/10.1142/s0217751x96000912.

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In the first part, the induced vacuum spin around an Aharonov-Bohm flux string in massless three-dimensional QED is computed explicitly and the result is shown to agree with a general index theorem. A previous observation in the literature, that the presence of induced vacuum quantum numbers which are not periodic in the flux make an integral-flux AB string visible, is reinforced. In the second part, a recent discussion of chiral symmetry breaking by external magnetic fields in parity-invariant QED 3 and its relation to the induced spin in parity-noninvariant QED 3 is further elaborated. Finally, other vacuum polarization effects around flux tubes in different variants of QED, in three and four dimensions are mentioned.

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17

Park, Yun H., Irina N. Sokolik, and Samuel R. Hall. "The Impact of Smoke on the Ultraviolet and Visible Radiative Forcing Under Different Fire Regimes." Air, Soil and Water Research 11 (January 1, 2018): 117862211877480. http://dx.doi.org/10.1177/1178622118774803.

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The quantification of the UV characteristics of smoke aerosols is valuable to UV Index forecasting, air quality studies, air chemistry studies, and assessments of the impacts on regional and global environmental changes. The wavelength dependence of the light absorption by smoke aerosol has been researched throughout the UV and visible spectral region and varies with fire type and aerosol composition. An objective of this study is to investigate the spectral optical properties (eg, extinction coefficient, single-scattering albedo, and asymmetry parameter), UV actinic fluxes, and radiative forcing of smoke of different fire regimes. The smoke aerosol information (eg, simulated smoke fields from biomass burning emission and vertical distribution of the mass concentration of smoke components) from WRF-Chem is used to distinguish 2 smoke types: flaming and smoldering. To compute the spectral optical properties for the fire regimes, the representative size distribution and spectral refractive index have been implemented into the Mie code, and the optical properties are used to run the tropospheric ultraviolet and visible radiative transfer model. We make comparisons between simulated model and measured actinic flux in the UV and visible spectra under smoke aerosol laden conditions. The WRF-Chem-SMOKE model simulates the smoke plume matched with fire locations and comparable aerosol optical depth (AOD) with satellite measurements. However, the correlation between the simulated and observed AOD is small, which implies that adjusting the fire size for the emission inputs and improving meteorological fields are required for further research. The smoke at selected locations reduces the UV actinic flux and increases the visible actinic flux above the plume at small solar zenith angles. The specific spectral response is dependent on the smoke type. Overall, the results of this investigation show that this approach is valuable to estimate the impact of smoke on UV and visible radiative fluxes.

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18

Rybin, B. M., I. A. Zavrazhnova, and D. B. Rybin. "Determining gloss of opaque protective and decorative coatings on wood and wood-based materials." Forestry Bulletin 26, no. 5 (October 2022): 102–11. http://dx.doi.org/10.18698/2542-1468-2022-5-102-111.

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A significant problem in the production of furniture is an objective assessment of the reflective properties of coating surfaces by gloss. Instrument readings are influenced by various factors such as color, saturation, lightness of the surface, roughness of the coating surface under study, the refractive index of a colored substance, etc. The calculations showed that the coefficients of absorption and reflection of visible radiation for colored substances are insignificant over 10 %. Although when light is reflected from the surface of a colored substance, the dominant wavelength range of the visible radiation spectrum is observed, which characterizes color, but its energy characteristics in relation to the reflected flux are insignificant. The total reflected flux characterizes the gloss of the coating, and the dominant color flux characterizes the color of the substance. For colored substances, it is not possible to use the refractive index in optical calculations. When absorbing and reflecting the visible spectrum of radiation from colored substances, anomalous dispersion is observed (the values of the refractive index change according to various dependencies inside the light absorption band and beyond it). The use of known gloss meters for assessing the gloss of opaque colored protective and decorative coatings requires the improvement of existing methods or the development of new ones that allow solving the multifactorial problem of influencing the gloss of color, saturation, lightness and roughness of the studied surfaces.

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19

Musielok, B. "The Nature of Balmer Line Variability in Chemically Peculiar Stars." International Astronomical Union Colloquium 90 (1986): 179–80. http://dx.doi.org/10.1017/s0252921100091454.

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Photoelectric measurements of the β-index were made for six Ap-stars (56 Ari, 41 Tau, φ Dra, HD 188041, HD 215441, HD 221568) and one He-rich star (HD 184927). For all these stars the minimum of β occurs at a phase of maximum light at a wavelength longward of the null-wavelength region. Such coincidence can be explained by the blanketing mechanism proposed by Kodaira (1973) for the explanation of the Hγ line variations in HD 221568. According to Kurucz (1979), for stars hotter than 9000K an increase of metal abundance in the atmosphere causes an increase of the visible flux and an simultanous decrease of equivalent widths of Balmer lines. The same changes of the visible flux and equivalent widths of Balmer lines can be obtained using a model atmosphere with a suitable higher temperature. Using the Kurucz (1979) model atmospheres, temperature differences were calculated, which are necessary to obtain the observed decrease of the (β-index and the increase of the flux in a given photometric band.

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20

Wu, Mengfei, Ting-An Lin, Jan O. Tiepelt, Vladimir Bulović, and Marc A. Baldo. "Nanocrystal-Sensitized Infrared-to-Visible Upconversion in a Microcavity under Subsolar Flux." Nano Letters 21, no. 2 (January 14, 2021): 1011–16. http://dx.doi.org/10.1021/acs.nanolett.0c04060.

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21

Tritschler, A., and H. Uitenbroek. "The Contrast of Magnetic Flux Concentrations at Near‐Infrared and Visible Wavelengths." Astrophysical Journal 648, no. 1 (September 2006): 741–52. http://dx.doi.org/10.1086/505700.

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22

van der Hage, J. C. H., and S. R. de Roode. "An Isotropic Light Sensor for Measurements of Visible Actinic Flux in Clouds." Journal of Atmospheric and Oceanic Technology 16, no. 11 (November 1999): 1698–701. http://dx.doi.org/10.1175/1520-0426(1999)016<1698:ailsfm>2.0.co;2.

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23

Anheier, N. C., M. J. Labiche, and M. M. Graff. "Intracavity multipass system for generation of high flux of cw visible light." Review of Scientific Instruments 60, no. 9 (September 1989): 3080–81. http://dx.doi.org/10.1063/1.1140613.

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24

Iliev, I. Kh. "Blanketing Hypothesis and Light Variations of HD 27309." International Astronomical Union Colloquium 90 (1986): 291–94. http://dx.doi.org/10.1017/s0252921100091673.

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AbstractThe influence of variable blanketing on the photometric variations of hot, silicon Ap star HD 27309 has been estimated. Spectrum variations in the visible are not the principal reason for the observed light variability, but flux redistribution from UV into visible fit well the observational data. An reference is made on the fulfillment of the variable blanketing assumptions at least for silicon Ap stars.

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25

Speetjens, M. F. M., and A. A. Van Steenhoven. "Heat and Mass Transfer Made Visible." Defect and Diffusion Forum 312-315 (April 2011): 713–18. http://dx.doi.org/10.4028/www.scientific.net/ddf.312-315.713.

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Heat and mass transfer in fluid flows traditionally is examined in terms of temperature and concentration fields and heat/mass-transfer coefficients at fluid-solid interfaces. However, heat/mass transfer may alternatively be considered as the transport of a passive scalar by the total advective-diffusive flux in a way analogous to the transport of fluid by the flow field. This Lagrangian approach facilitates heat/mass-transfer visualisation in a similar manner as flow visualisation and has great potential for transport problems in which insight into (interaction between) the scalar fluxes throughout the entire configuration is essential. This ansatz furthermore admits investigation of heat and mass transfer by well-established geometrical methods from laminar-mixing studies, which offers promising new research capabilities. The Lagrangian approach is introduced and demonstrated by way of representative examples.

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26

Shaban, Y. R., and G. H. Miley. "Practical, visible wavelength nuclear-pumped laser." Laser and Particle Beams 11, no. 3 (September 1993): 559–66. http://dx.doi.org/10.1017/s0263034600005218.

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A practical, visible nuclear-pumped laser (NPL) has been sought at the University of Illinois and other laboratories for a number of years. Yet, the results from successful visible NPLs to date have not been fully satisfactory, e.g., the threshold pumping power is too high for conventional applications. Progress in recent studies of 3He-Ne-H2 as a candidate NPL operating in the visible region at 585.3 nm on the 2P1,-1S2 Ne transition is described. We obtained lasing on the above transition for 3He-Ne-H2 concentrations of 1,140, 588, and 412 torr, respectively, with the laser cavity placed in the beamport of the University of Illinois TRIGA reactor. The threshold thermal neutron flux is 1014 n/cm2-s, corresponding to a threshold pumping power of 5 W/cm3.

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27

Kontogiannis, I., G. Tsiropoula, K. Tziotziou, C. Gontikakis, C. Kuckein, M. Verma, and C. Denker. "Emergence of small-scale magnetic flux in the quiet Sun." Astronomy & Astrophysics 633 (January 2020): A67. http://dx.doi.org/10.1051/0004-6361/201936778.

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Context. We study the evolution of a small-scale emerging flux region (EFR) in the quiet Sun, from its emergence in the photosphere to its appearance in the corona and its decay. Aims. We track processes and phenomena that take place across all atmospheric layers; we explore their interrelations and compare our findings with those from recent numerical modelling studies. Methods. We used imaging as well as spectral and spectropolarimetric observations from a suite of space-borne and ground-based instruments. Results. The EFR appears in the quiet Sun next to the chromospheric network and shows all morphological characteristics predicted by numerical simulations. The total magnetic flux of the region exhibits distinct evolutionary phases, namely an initial subtle increase, a fast increase with a Co-temporal fast expansion of the region area, a more gradual increase, and a slow decay. During the initial stages, fine-scale G-band and Ca II H bright points coalesce, forming clusters of positive- and negative-polarity in a largely bipolar configuration. During the fast expansion, flux tubes make their way to the chromosphere, pushing aside the ambient magnetic field and producing pressure-driven absorption fronts that are visible as blueshifted chromospheric features. The connectivity of the quiet-Sun network gradually changes and part of the existing network forms new connections with the newly emerged bipole. A few minutes after the bipole has reached its maximum magnetic flux, the bipole brightens in soft X-rays forming a coronal bright point. The coronal emission exhibits episodic brightenings on top of a long smooth increase. These coronal brightenings are also associated with surge-like chromospheric features visible in Hα, which can be attributed to reconnection with adjacent small-scale magnetic fields and the ambient quiet-Sun magnetic field. Conclusions. The emergence of magnetic flux even at the smallest scales can be the driver of a series of energetic phenomena visible at various atmospheric heights and temperature regimes. Multi-wavelength observations reveal a wealth of mechanisms which produce diverse observable effects during the different evolutionary stages of these small-scale structures.

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28

Nakazawa, Y., K. Godo, K. Niwa, T. Zama, Y. Yamaji, and S. Matsuoka. "Development of LED-based standard source for total luminous flux calibration." Lighting Research & Technology 51, no. 6 (September 20, 2018): 870–82. http://dx.doi.org/10.1177/1477153518800746.

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For total luminous flux calibration by a sphere-spectroradiometer system in 2π geometry, a new LED-based standard light source (standard LED) covering the full visible wavelength range has been developed. The developed standard LED has sufficient spectral power over the full visible wavelength range using UV-LED dies of different peak wavelengths in combination with red, green and blue phosphors. By evaluating spectrum flatness based on the magnitude of the second derivative, the spectrum of the standard LED was customised to minimise the measurement uncertainty. Properties of the standard LED such as the luminous intensity distribution, stability and reproducibility were also evaluated. The evaluation results indicate that the standard LED has good properties as a standard light source for the 2π total spectral radiant flux scale. Furthermore, the result of an operating current dependence suggests that the standard LED has benefits as a standard source that conventional standard lamps do not have.

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29

Glass, I. S. "3.14. Infrared variations of active galaxies: what they tell us." Symposium - International Astronomical Union 184 (1998): 117–18. http://dx.doi.org/10.1017/s0074180900084278.

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Little is known about the long-term infrared variations of Seyfert galaxies. Are they large or small, fast or slow, regular or irregular? Do they possess variable components hidden at visible wavelengths? Can their variational time-scales give us information about activity on sub-milliarcsecond spatial scales? Do the infrared measurements show well-defined flux variation gradients? Is the infrared flux delayed with respect to changes in the output of the central engine? And do the infrared variability studies support the “Unified Model”?

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30

Bonifacio, Piercarlo, and Fiorella Castelli. "The Impact of Reddening on the Observed Fluxes of a Stars." International Astronomical Union Colloquium 138 (1993): 143–48. http://dx.doi.org/10.1017/s0252921100020406.

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AbstractWe compare observed ultraviolet and visible flux distributions, for a sample of A-type stars, with computed fluxes obtained with version 9 of the ATLAS code (Kurucz, 1970) in order to asses the impact of reddening. We also make a comparison between determinations of reddening from UV colour indices and visible wide band (Johnson) and intermediate band (Strömgren) colour indices. We discuss the implications on the study of slightly reddened high galactic latitude stars.

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31

Carrington, Samantha J., Indranil Chakraborty, and Pradip K. Mascharak. "Exceptionally rapid CO release from a manganese(i) tricarbonyl complex derived from bis(4-chloro-phenylimino)acenaphthene upon exposure to visible light." Dalton Transactions 44, no. 31 (2015): 13828–34. http://dx.doi.org/10.1039/c5dt01007a.

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Both in solid state and in solution, the manganese carbonyl complex [MnBr(CO)₃(BIAN)] rapidly releases CO upon illumination with visible light. This complex could find use in delivery of rapid flux of CO to biological targets.

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32

Wonsick, Margaret M., Rachel T. Pinker, Wen Meng, and Louis Nguyen. "Evaluation of Surface Shortwave Flux Estimates from GOES: Sensitivity to Sensor Calibration." Journal of Atmospheric and Oceanic Technology 23, no. 7 (July 1, 2006): 927–35. http://dx.doi.org/10.1175/jtech1894.1.

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Abstract Parameters derived from satellite observations depend on the quality of the calibration method applied to the raw satellite radiance measurements. This study investigates the sensitivity of absolute reflectance, derived cloud cover, and estimated surface shortwave (SW) downward fluxes to two different calibration methods for the visible sensor aboard the eighth Geostationary Operational Environmental Satellite (GOES-8). The first method was developed at NOAA's National Environmental Satellite, Data, and Information Service (NESDIS), and the second at the NASA Langley Research Center. Differences in visible reflectance ranged from −0.5% to 3%. The average difference in monthly mean cloud amount was ∼3%, and the average difference in monthly mean shortwave downward flux was 5 W m−2. Differences in bias and rms of the SW fluxes when evaluated against ground station measurements were less than 3 W m−2. Neither calibration method was shown to consistently outperform the other. This evaluation yields an estimate of the errors in fluxes that can be attributed to calibration.

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33

Hidayat, Muhammad, Arwin Juli Rakhmadi, and Abu Yazid Raisal. "Measuring the Apparent Magnitude of Planet Mars on August 1st and October 2nd, 2018 at the Falak Observatory at Muhammadiyah University of North Sumatera." Indonesian Review of Physics 3, no. 1 (May 30, 2020): 6. http://dx.doi.org/10.12928/irip.v3i1.1838.

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The Bright stars that were seen by the eyes are the received quantity of the energy flux sent from the celestial body. The energy flux is inversely proportional to the distant quadrant which means that the light of the stars that are visible to our eyes cannot be compared to the actual brightness or even weaker than the others and the visible star lights the apparent magnitude. The purpose of this study is to measure the apparent magnitude of Mars. This research methodology is quantitative, by taking number of images/videos of Mars and then the data is processed by using IRIS software. The results of the analysis is using IRIS software that shows the value of the apparent magnitude of Mars on August 1st, 2018 is (-1.56 ± 0.33) and October 2nd 2018 is (-1.84 ± 0.08). This was taken by selecting the best image result in clear night sky.

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34

Ma, W., Y. Ma, M. Li, Z. Hu, L. Zhong, Z. Su, H. Ishikawa, and J. Wang. "Estimating surface fluxes over the north Tibetan Plateau area with ASTER imagery." Hydrology and Earth System Sciences Discussions 5, no. 4 (July 1, 2008): 1705–30. http://dx.doi.org/10.5194/hessd-5-1705-2008.

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Abstract. Surface fluxes are important boundary conditions for climatological modeling and Asian monsoon system. The recent availability of high-resolution, multi-band imagery from the ASTER (Advanced Space-borne Thermal Emission and Reflection radiometer) sensor has enabled us to estimate surface fluxes. ASTER covers a wide spectral region with 14 bands from the visible to the thermal infrared with high spatial, spectral and radiometric resolution. The spatial resolution varies with wavelength: 15 m in the visible and near-infrared (VNIR), 30 m in the short wave infrared (SWIR), and 90 m in the thermal infrared (TIR). A parameterization method based on ASTER data and field observations has been proposed and tested for deriving surface albedo, surface temperature, Normalized Difference Vegetation Index (NDVI), Modified Soil Adjusted Vegetation Index (MSAVI), vegetation coverage, Leaf Area Index (LAI), net radiation flux, soil heat flux, sensible heat flux and latent heat flux over heterogeneous land surface in this paper. As a case study, the methodology was applied to the experimental area of the Coordinated Enhanced Observing Period (CEOP) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau (CAMP/Tibet), which located at the north Tibetan Plateau. The ASTER data of 24 July 2001, 29 November 2001 and 12 March 2002 was used in this paper for the case of summer, winter and spring. To validate the proposed methodology, the ground-measured surface variables (surface albedo and surface temperature) and land surface heat fluxes (net radiation flux, soil heat flux, sensible heat flux and latent heat flux) were compared to the ASTER derived values. The results show that the derived surface variables and land surface heat fluxes in three different months over the study area are in good accordance with the land surface status. Also, the estimated land surface variables and land surface heat fluxes are in good accordance with ground measurements, and all their absolute percent difference (APD) is less than 10% in the validation sites. It is therefore concluded that the proposed methodology is successful for the retrieval of land surface variables and land surface heat fluxes using the ASTER data and filed observation over the study area.

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35

Kim, Dong Eok, and Junseok Park. "Experimental study of critical heat flux in pool boiling using visible-ray optics." International Journal of Heat and Mass Transfer 169 (April 2021): 120937. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2021.120937.

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36

Hamilton, Devon, and John B. Lester. "A Technique for the Study of Stellar Convection: The Visible Solar Flux Spectrum." Publications of the Astronomical Society of the Pacific 111, no. 763 (September 1999): 1132–43. http://dx.doi.org/10.1086/316421.

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37

Landau, I. L., and Leo Rinderer. "Influence of weak visible light on flux creep in HTSC at low temperatures." Czechoslovak Journal of Physics 46, S3 (March 1996): 1721–22. http://dx.doi.org/10.1007/bf02562975.

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38

Landau, I. L., and L. Rinderer. "Influence of weak visible light on flux creep in HTSC at low temperatures." Superlattices and Microstructures 21, no. 3 (April 1997): 427–30. http://dx.doi.org/10.1006/spmi.1996.0412.

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39

Kawashima, Kenta, Mirabbos Hojamberdiev, Oluwaniyi Mabayoje, Bryan R. Wygant, Kunio Yubuta, C. Buddie Mullins, Kazunari Domen, and Katsuya Teshima. "NH3-assisted chloride flux-coating method for direct fabrication of visible-light-responsive SrNbO2N crystal layers." CrystEngComm 19, no. 37 (2017): 5532–41. http://dx.doi.org/10.1039/c7ce00614d.

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40

Liu, Rong, Jun Wen, Xin Wang, Zuoliang Wang, Yu Liu, and Ming Zhang. "Estimates of Daily Evapotranspiration in the Source Region of the Yellow River Combining Visible/Near-Infrared and Microwave Remote Sensing." Remote Sensing 13, no. 1 (December 25, 2020): 53. http://dx.doi.org/10.3390/rs13010053.

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The spatial variation of surface net radiation, soil heat flux, sensible heat flux, and latent heat flux at different times of the day over the northern Tibetan Plateau were estimated using the Surface Energy Balance System algorithm, data from the FY-2G geostationary meteorological satellite, and microwave data from the FY-3C polar-orbiting meteorological satellite. In addition, the evaporative fraction was analyzed, and the total evapotranspiration (ET) was obtained by the effective evaporative fraction to avoid the error from accumulation. The hourly change of latent heat flux presented a sound unimodal diurnal variation. The results showed the regional ET ranged between 2.0 and 4.0 mm over the Source Region of the Yellow River. The conditional expectations of surface energy components during the experimental period of the study area were statistically analyzed, and the correspondence between different surface temperatures and the effective energy distribution was examined. The effective energy distribution of the surface changed significantly with the increase in temperature; in particular, when the surface temperature exceeded 290 K, the effective energy was mainly used for surface ET. The aim of this study was to avoid the use of surface meteorological observations that are not readily available over large areas, and the findings lay a foundation for the commercialization of land surface evapotranspiration.

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41

Maartens, A., P. Swart, and E. P. Jacobs. "Removal of Natural Organic Matter by Ultrafiltration: Characterisation, Fouling and Cleaning." Water Science and Technology 40, no. 9 (November 1, 1999): 113–20. http://dx.doi.org/10.2166/wst.1999.0456.

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Organic matter in natural brown water as well as humic acids from a commercial sample were characterised by ultraviolet-visible light-spectroscopy and used in ultrafiltration studies. During ultrafiltration the pure-water flux and the operational flux were measured continuously to determine the degree of membrane fouling. The natural organic matter and commercial humic acid concentrations of the feed and permeate solutions were determined spectrophotometrically. These variables were used in conjunction with conventional flux measurements, to determine the colour-removal efficiency of ultrafiltration as well as the degree of foulant adsorption onto the membranes. Fouled membranes were cleaned with alkaline chemical agents normally used to extract natural organic matter from soil samples. The cleaning efficiency and the effect of cleaning solutions on the membrane selectivity were studied.

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42

Takeuchi, Masao, and Yoshifumi Fukuzawa. "Light Attentuation and Visibility in Blowing Snow." Annals of Glaciology 6 (1985): 311–13. http://dx.doi.org/10.3189/1985aog6-1-311-313.

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Visibility in blowing snow was investigated by measurements of visibility using optical targets, light attenuation of parallel beam and snow concentration and mass flux of airborne snow particles.Visibility is thought to be inversely proportional to extinction coefficient of light according to Koschmeider’s equation of visibility. However, visually observed values are not in accordance with those calculated from extinction coefficient of light when visibility is at a very low range. The extinction coefficient of light is proportional to the total cross section of airborne snow particles in a light path. The total cross section is also in proportion to concentration of airborne snow particles. There are many reported investigations of relation between visibility and snow concentration with widely differing results. The extinction coefficient of light varies with the shape and size of the particles, but cannot totally account for observed differences.Transforming the snow concentration into mass flux of snow particles, a better relation between visibility and mass flux was found. These facts are explained in terms of the size of snow particles which are large enough to be seen. Visibility through visible particles is determined not only by the homogeneous attenuation of light discovered by Koschmeider, but also by the influence of visible particles themselves and their afterimage.

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43

Takeuchi, Masao, and Yoshifumi Fukuzawa. "Light Attentuation and Visibility in Blowing Snow." Annals of Glaciology 6 (1985): 311–13. http://dx.doi.org/10.1017/s0260305500010752.

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Анотація:

Visibility in blowing snow was investigated by measurements of visibility using optical targets, light attenuation of parallel beam and snow concentration and mass flux of airborne snow particles. Visibility is thought to be inversely proportional to extinction coefficient of light according to Koschmeider’s equation of visibility. However, visually observed values are not in accordance with those calculated from extinction coefficient of light when visibility is at a very low range. The extinction coefficient of light is proportional to the total cross section of airborne snow particles in a light path. The total cross section is also in proportion to concentration of airborne snow particles. There are many reported investigations of relation between visibility and snow concentration with widely differing results. The extinction coefficient of light varies with the shape and size of the particles, but cannot totally account for observed differences. Transforming the snow concentration into mass flux of snow particles, a better relation between visibility and mass flux was found. These facts are explained in terms of the size of snow particles which are large enough to be seen. Visibility through visible particles is determined not only by the homogeneous attenuation of light discovered by Koschmeider, but also by the influence of visible particles themselves and their afterimage.

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44

MacQueen, R. M., W. C. Davidson, and I. Mann. "The Role of Particle Size in Producing the F- Coronal Scattered Brightness." International Astronomical Union Colloquium 150 (1996): 349–52. http://dx.doi.org/10.1017/s0252921100501833.

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AbstractMotivated by new infrared observations, we examine the contribution of various size intervals of interplanetary dust particles to visible and infrared scattered radiances of the solar F-corona, employing Mie theory and particle size distributions based upon differing interpretations of lunar microcrater evidence and interplanetary flux measurements.

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45

Wang, Qiang, Qingjun Guo, Leping Wang, and Bing Li. "The flux growth of single-crystalline CoTiO3 polyhedral particles and improved visible-light photocatalytic activity of heterostructured CoTiO3/g-C3N4 composites." Dalton Transactions 45, no. 44 (2016): 17748–58. http://dx.doi.org/10.1039/c6dt03449g.

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Novel CoTiO₃/g-C₃N₄ heterostructures with improved photocatalytic activity were successfully synthesized by a facile in situ growth route with the flux-grown CoTiO₃ polyhedral crystals serving as an efficient visible-light sensitizer.

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46

Moujtahid, A., J. Zorec, and A. M. Hubert. "On the Characteristics of Circumstellar Envelopes in Be Stars near the Central Object." International Astronomical Union Colloquium 175 (2000): 506–9. http://dx.doi.org/10.1017/s0252921100056372.

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AbstractObserved visible energy distributions of Be stars were studied with analytic flux distributions produced by flattened circumstellar envelopes. The theoretical representation of emitted fluxes also allows for density distribution effects in the region where the visible continuum emission/absorption is raised. Two main conclusions were reached: (a) regions responsible for spectrophotometric ”shell” phases have, on average, steeper density distributions than those producing the spectrophotometric ”Be” phases; (b) the mean temperatures of the studied circumstellar envelope regions shows a linear relation with their mean ”inverse” extent R*/R.

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47

Hoshika, Yasutomo, Elisa Carrari, Barbara Mariotti, Sofia Martini, Alessandra De Marco, Pierre Sicard, and Elena Paoletti. "Flux-Based Ozone Risk Assessment for a Plant Injury Index (PII) in Three European Cool-Temperate Deciduous Tree Species." Forests 11, no. 1 (January 9, 2020): 82. http://dx.doi.org/10.3390/f11010082.

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This study investigated visible foliar ozone (O3) injury in three deciduous tree species with different growth patterns (indeterminate, Alnus glutinosa (L.) Gaertn.; intermediate, Sorbus aucuparia L.; and determinate, Vaccinium myrtillus L.) from May to August 2018. Ozone effects on the timing of injury onset and a plant injury index (PII) were investigated using two O3 indices, i.e., AOT40 (accumulative O3 exposure over 40 ppb during daylight hours) and PODY (phytotoxic O3 dose above a flux threshold of Y nmol m−2 s−1). A new parameterization for PODY estimation was developed for each species. Measurements were carried out in an O3 free-air controlled exposure (FACE) experiment with three levels of O3 treatment (ambient, AA; 1.5 × AA; and 2.0 × AA). Injury onset was found in May at 2.0 × AA in all three species and the timing of the onset was determined by the amount of stomatal O3 uptake. It required 4.0 mmol m−2 POD0 and 5.5 to 9.0 ppm·h AOT40. As a result, A. glutinosa with high stomatal conductance (gs) showed the earliest emergence of O3 visible injury among the three species. After the onset, O3 visible injury expanded to the plant level as confirmed by increased PII values. In A. glutinosa with indeterminate growth pattern, a new leaf formation alleviated the expansion of O3 visible injury at the plant level. V. myrtillus showed a dramatic increase of PII from June to July due to higher sensitivity to O3 in its flowering and fruiting stage. Ozone impacts on PII were better explained by the flux-based index, PODY, as compared with the exposure-based index, AOT40. The critical levels (CLs) corresponding to PII = 5 were 8.1 mmol m−2 POD7 in A. glutinosa, 22 mmol m−2 POD0 in S. aucuparia, and 5.8 mmol m−2 POD1 in V. myrtillus. The results highlight that the CLs for PII are species-specific. Establishing species-specific O3 flux-effect relationships should be key for a quantitative O3 risk assessment.

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48

Livadiotis, George, and Xenophon Moussas. "The maximum magnetic flux in an active region." Proceedings of the International Astronomical Union 4, S257 (September 2008): 101–8. http://dx.doi.org/10.1017/s1743921309029159.

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AbstractThe Photometric-Magnetic Dynamical model handles the evolution of an individual sunspot as an autonomous nonlinear, though integrable, dynamical system. The model considers the simultaneous interplay of two different interacted factors: The photometric and magnetic factors, respectively, characterizing the evolution of the sunspot visible area A on the photosphere, and the simultaneous evolution of the sunspot magnetic field strength B. All the possible sunspots are gathered in a specific region of the phase space (A, B). The separatrix of this phase space region determines the upper limit of the values of sunspot area and magnetic strength. Consequently, an upper limit of the magnetic flux in an active region is also determined, found to be ≈7.23 × 1023 Mx. This value is phenomenologically equal to the magnetic flux concentrated in the totality of the granules of the quite Sun. Hence, the magnetic flux concentrated in an active region cannot exceed the one concentrated in the whole photosphere.

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49

Bless, R. C., and J. W. Percival. "The bolometric luminosities of stars." Symposium - International Astronomical Union 189 (1997): 73–82. http://dx.doi.org/10.1017/s0074180900116523.

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The total energy emitted by a star is one of its basic parameters. It is also one of the most difficult to determine, requiring space-based as well as ground-based measurements of the absolute flux from stars. We review the current status of these observations in the ultraviolet, visible, and near infrared, and estimate the uncertainties of the absolute flux measurements in these spectral regions. We compare recent determinations of the bolometric luminosity of early-type stars with the first (mostly) empirical results of 20 years ago. We close with a few comments on possible improvements of these measurements in the future.

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50

Irshad, Liu, Arshad, Sohail, Murthy, Khokhar, and Uba. "A Novel Localization Technique Using Luminous Flux." Applied Sciences 9, no. 23 (November 21, 2019): 5027. http://dx.doi.org/10.3390/app9235027.

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As global navigation satellite system (GNNS) signals are unable to enter indoor spaces, substitute methods such as indoor localization-based visible light communication (VLC) are gaining the attention of researchers. In this paper, the systematic investigation of a VLC channel is performed for both direct and indirect line of sight (LoS) by utilizing the impulse response of indoor optical wireless channels. In order to examine the localization scenario, two light-emitting diode (LED) grid patterns are used. The received signal strength (RSS) is observed based on the positional dilution of precision (PDoP), a subset of the dilution of precision (DoP) used in global navigation satellite system (GNSS) positioning. In total, 31 × 31 possible positional tags are set for a given PDoP configuration. The values for positional error in terms of root mean square error (RMSE) and the sum of squared errors (SSE) are taken into consideration. The performance of the proposed approach is validated by simulation results according to the selected indoor space. The results show that the position accuracy enhanced is at short range by 24% by utilizing the PDoP metric. As confirmation, the modeled accuracy is compared with perceived accuracy results. This study determines the application and design of future optical wireless systems specifically for indoor localization.

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