Journal articles: 'Modèle de radiation'

1

Commenges, Hadrien. "Modèle de radiation et modèle gravitaire." Revue Internationale de Géomatique 26, no. 1 (2016): 79–95. http://dx.doi.org/10.3166/rig.26.79-95.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Nameche, T., and J. L. Vassel. "Bilan thermique sous climat tempéré des lagunes aérées et naturelles." Revue des sciences de l'eau 12, no. 1 (2005): 65–91. http://dx.doi.org/10.7202/705344ar.

Full text

Abstract:

Un modèle décrivant la température d'équilibre des lagunes a été développé, tenant compte des différents flux de chaleur que celles-ci échangent avec l'air et le sol environnant. Six composantes différentes ont été inclues dans le calcul de ce bilan thermique: radiation solaire, évaporation, convection, rayonnement atmosphérique, rayonnement de la surface du plan d'eau, échange via les parois en contact avec le sol. Le modèle ainsi obtenu a été testé avec efficacité sur deux lagunes aérées et une lagune naturelle situées sous climat tempéré ; sa précision sur l'estimation des températures d'équilibre étant de l'ordre de 0.7 °C. Des simulations en continu ont également pu être effectuées au moyen d'une variante dynamique, tenant compte de l'inertie thermique qu'entraîne le volume des bassins. Quelle que soit la saison envisagée, la principale forme d'apport de chaleur est représentée par la radiation solaire tandis que la dissipation d'énergie se partage entre les flux d'évaporation et la balance des deux flux de rayonnement. Les bassins échangeraient en moyenne plus de 250 W/m2 ; le maximum de transfert de chaleur correspondant au printemps et à la période estivale. Enfin, l'analyse de sensibilité du modèle nous a permis de mettre en évidence la contribution de chacun des termes intervenant dans le calcul de ce bilan thermique et de révéler sa dépendance vis-à-vis principalement de la température d'entrée, du rayonnement solaire et de la température de l'air.

APA, Harvard, Vancouver, ISO, and other styles

3

Rousseau, Daniel, Michel Jarraud, and Pascal Marquet. "Les débuts de Jean-François Geleyn : Mayence, Paris et son expérience au CEPMMT." La Météorologie, no. 112 (2021): 023. http://dx.doi.org/10.37053/lameteorologie-2021-0015.

Full text

Abstract:

La carrière scientifique de Jean-François Geleyn débute à l'université de Mayence, où il acquit une formation complémentaire sur le rayonnement atmosphérique, après sa formation à l'École nationale de la météorologie. À son retour à Paris, il enseigna son premier cours de rayonnement et expérimenta un premier schéma vertical de paramétrisations physiques. Recruté par le CEPMMT, il intégra la première équipe qui développa avec succès les paramétrisations physiques du modèle du Centre. Grâce à sa polyvalence sur tous les aspects de la prévision numérique, à ses qualités d'analyse et de synthèse, il contribua très activement aux développements du modèle du Centre. Jean-François Geleyn's scientific career began at the University of Mainz, where he received further training in atmospheric radiation, after his training at the National Meteorological School. On his return to Paris, he taught his first radiation course and experimented a first vertical scheme of physical parameterizations. Recruited by the ECMWF, he joined the first team who successfully developed the physical parameterizations of the ECMWF model. Thanks to his versatility in all aspects of numerical forecasting, his analytical and synthesis skills, he contributed very actively to the development of the ECMWF model.

APA, Harvard, Vancouver, ISO, and other styles

4

Morin, Guy, Tonino-Joseph Nzakimuena, and Wanda Sochanski. "Prévision des températures de l'eau en rivières à l'aide d'un modèle conceptuel : le cas de la rivière Moisie." Canadian Journal of Civil Engineering 21, no. 1 (1994): 63–75. http://dx.doi.org/10.1139/l94-006.

Full text

Abstract:

Hydro-Québec is projecting to increase the hydroelectric production capacity of the St. Marguerite River by diversion of the tributaries Pékans and Carheil rivers of the Moisie River, the most productive salmon river of the whole Quebec. Along with substantial changes in hydrological regimes, this hydroelectric development is most likely to affect some physical environment factors such as the water temperature, which is of prime importance for the biotope and, in particular, for the salmon productivity. The objective of the present study is to simulate, over a long period of time, the river water temperatures under natural conditions as compare to those after the impoundment, to assess the consequences of the tributary diversion. We used the hydrological CEQUEAU model coupled with a temperature model.The temperature model developed is applicable to the ice-free period and calculates daily water temperatures in rivers by computing an energy budget to each element of the watershed. The energy budget considers the short-wave solar radiation, long-wave radiation, evaporation, and convection in the air as well as the advective heat of various inflows from surface runoff, interflow, and groundwaters. The estimation of the atmospheric thermal exchanges is based on the equations usually found in literature. The volumes of the various inflows are given by the hydrological model. The temperature model uses daily data for air temperature and monthly data for solar radiation, cloudiness, wind speed, and vapour pressure.The model has been applied to the Moisie River (Québec), using the measured values for the calibration. Both observed and calculated values show good agreement. The model was also used to simulate, over the whole watershed, the water temperatures for the 1961–1989 period and after the diversion. The results show that the tributary diversion contributed to increase the water temperature of the Moisie River and that this increase is gradually attenuated as we progress downstream. Key words: temperature, impacts, model, Moisie, Québec, diversion, hydrology.

APA, Harvard, Vancouver, ISO, and other styles

5

Gallée, H., S. Preunkert, S. Argentini, et al. "Characterization of the boundary layer at Dome C (East Antarctica) during the OPALE summer campaign." Atmospheric Chemistry and Physics 15, no. 11 (2015): 6225–36. http://dx.doi.org/10.5194/acp-15-6225-2015.

Full text

Abstract:

Abstract. Regional climate model MAR (Modèle Atmosphérique Régional) was run for the region of Dome C located on the East Antarctic plateau, during Antarctic summer 2011–2012, in order to refine our understanding of meteorological conditions during the OPALE tropospheric chemistry campaign. A very high vertical resolution is set up in the lower troposphere, with a grid spacing of roughly 2 m. Model output is compared with temperatures and winds observed near the surface and from a 45 m high tower as well as sodar and radiation data. MAR is generally in very good agreement with the observations, but sometimes underestimates cloud formation, leading to an underestimation of the simulated downward long-wave radiation. Absorbed short-wave radiation may also be slightly overestimated due to an underestimation of the snow albedo, and this influences the surface energy budget and atmospheric turbulence. Nevertheless, the model provides sufficiently reliable information about surface turbulent fluxes, vertical profiles of vertical diffusion coefficients and boundary layer height when discussing the representativeness of chemical measurements made nearby the ground surface during field campaigns conducted at Concordia station located at Dome C (3233 m above sea level).

APA, Harvard, Vancouver, ISO, and other styles

6

Chebbah, Lynda, Lakhdar Djemili, Mohammed Tawfik Bouziane, and Mohamed Chiblak. "Modélisation d'un masque en béton bitumineux (brut et protégé) sous sollicitations thermiques en régime transitoire. cas du masque de barrage Ghrib (Ain Defla, Algérie)." La Houille Blanche, no. 1 (February 2020): 42–49. http://dx.doi.org/10.1051/lhb/2019064.

Full text

Abstract:

Le masque en béton bitumineux est l'un des organes les plus utilisés pour l'étanchéité des barrages en remblai. Le parement en béton bitumineux est, en particulier dans le cas des installations de stockage par pompage hydroélectriques, sont souvent très exposé à des fluctuations importantes de température, qui sont causées par la radiation solaire, la variation du niveau d'eau dans le réservoir, par le gel dans la saison d'hiver, ainsi que la vitesse et la direction du vent, sans oublier les précipitations. Pour mieux expliquer le phénomène de transfert de chaleur, il est nécessaire de connaître les variations de température dans les différentes couches du masque en béton bitumineux. Ce travail décrit la mesure de la température dans le masque en béton bitumineux (brut et avec protection) du barrage Ghrib (Ain Defla, Algérie) et son évaluation à l'aide d'un modèle numérique du transfert de chaleur dans le parement en béton bitumineux en utilisant le logiciel Fluent. Dans un premier temps une validation du modèle par comparaison avec des mesures expérimentales, dans le cas d'une variation journalière de température ambiante, La comparaison des résultats du calcul du modèle numérique avec les mesures réelles montre une excellente ressemblance. Nous simulons ensuite la pose d'une protection thermique en ajoutons une couche convective en béton poreux. Les résultats de cette simulation montrent que le transfert de chaleur par convection possède le potentiel de développer une différence de température significative entre les parties inférieure et supérieure du masque, et aussi que l'ajout de cette couche permet d'amortir le pic de température et le réduire à 12,31 °C, ceci de 9 h jusqu'à 15 h au moment où la chaleur est très élevée, ce qui est significatif pour notre masque, où les températures atteignant leurs valeurs maximales (49 °C).

APA, Harvard, Vancouver, ISO, and other styles

7

Colombo, S., L. Ibgui, S. Orlando, et al. "Non-LTE radiation hydrodynamics in PLUTO." Astronomy & Astrophysics 631 (October 23, 2019): A41. http://dx.doi.org/10.1051/0004-6361/201935991.

Full text

Abstract:

Context. Modeling the dynamics of most astrophysical structures requires an adequate description of the interaction of radiation and matter. Several numerical (magneto-) hydrodynamics codes were upgraded with a radiation module to fulfill this request. However, those that used either the flux-limited diffusion (FLD) or the M1 radiation moment approaches are restricted to local thermodynamic equilibrium (LTE). This assumption may not be valid in some astrophysical cases. Aims. We present an upgraded version of the LTE radiation-hydrodynamics (RHD) module implemented in the PLUTO code, which we have extended to handle non-LTE regimes. Methods. Starting from the general frequency-integrated comoving-frame equations of RHD, we have justified all the assumptions that were made to obtain the non-LTE equations that are implemented in the module under the FLD approximation. An operator-split method with two substeps was employed: the hydrodynamics part was solved with an explicit method by the solvers that are currently available in PLUTO, and the non-LTE radiation diffusion and energy exchange part was solved with an implicit method. The module was implemented in the PLUTO environment. It uses databases of radiative quantities that can be provided independently by the user: the radiative power loss, and the Planck and Rosseland mean opacities. In our case, these quantities were determined from a collisional-radiative steady-state model, and they are tabulated as functions of temperature and density. Results. Our implementation has been validated through different tests, in particular, radiative shock tests. The agreement with the semi-analytical solutions (when available) is good, with a maximum error of 7%. Moreover, we have proved that a non-LTE approach is of paramount importance to properly model accretion shock structures. Conclusion. Our radiation FLD module represents a step toward a general non-LTE RHD modeling.

APA, Harvard, Vancouver, ISO, and other styles

8

Lang, C., X. Fettweis, and M. Erpicum. "Future climate and surface mass balance of Svalbard glaciers in an RCP8.5 climate scenario: a study with the regional climate model MAR forced by MIROC5." Cryosphere 9, no. 3 (2015): 945–56. http://dx.doi.org/10.5194/tc-9-945-2015.

Full text

Abstract:

Abstract. We have performed a future projection of the climate and surface mass balance (SMB) of Svalbard with the MAR (Modèle Atmosphérique Régional) regional climate model forced by MIROC5 (Model for Interdisciplinary Research on Climate), following the RCP8.5 scenario at a spatial resolution of 10 km. MAR predicts a similar evolution of increasing surface melt everywhere in Svalbard followed by a sudden acceleration of melt around 2050, with a larger melt increase in the south compared to the north of the archipelago. This melt acceleration around 2050 is mainly driven by the albedo–melt feedback associated with the expansion of the ablation/bare ice zone. This effect is dampened in part as the solar radiation itself is projected to decrease due to a cloudiness increase. The near-surface temperature is projected to increase more in winter than in summer as the temperature is already close to 0 °C in summer. The model also projects a stronger winter west-to-east temperature gradient, related to the large decrease of sea ice cover around Svalbard. By 2085, SMB is projected to become negative over all of Svalbard's glaciated regions, leading to the rapid degradation of the firn layer.

APA, Harvard, Vancouver, ISO, and other styles

9

Panchenko, Vladimir. "Photovoltaic Thermal Module With Paraboloid Type Solar Concentrators." International Journal of Energy Optimization and Engineering 10, no. 2 (2021): 1–23. http://dx.doi.org/10.4018/ijeoe.2021040101.

Full text

Abstract:

The article presents the results of the development and research of the solar photovoltaic thermal module with paraboloid type solar radiation concentrators. The structure of the solar module includes a composite concentrator, which provides uniform illumination by concentrated solar radiation on the surface of the cylindrical photovoltaic thermal photoreceiver in the form of the aluminum radiator with photovoltaic converters. When exposed in concentrated solar radiation, the electrical efficiency of specially designed matrix photovoltaic converters increases, and the heat taken by the heat carrier increases the overall efficiency of the solar module. Uniform illumination of photovoltaic converters with concentrated solar radiation provides an optimal mode of operation. The consumer can use the received electric and thermal energy in an autonomous or parallel power supply with the existing power grid.

APA, Harvard, Vancouver, ISO, and other styles

10

Augas, Julien, Kian Abbasnezhadi, Alain N. Rousseau, and Michel Baraer. "What is the Trade-Off between Snowpack Stratification and Simulated Snow Water Equivalent in a Physically-Based Snow Model?" Water 12, no. 12 (2020): 3449. http://dx.doi.org/10.3390/w12123449.

Full text

Abstract:

In Nordic watersheds, estimation of the dynamics of snow water equivalent (SWE) represents a major step toward a satisfactory modeling of the annual hydrograph. For a multilayer, physically-based snow model like MASiN (Modèle Autonome de Simulation de la Neige), the number of modeled snow layers can affect the accuracy of the simulated SWE. The objective of this study was to identify the maximum number of snow layers (MNSL) that would define the trade-off between snowpack stratification and SWE modeling accuracy. Results indicated that decreasing the MNSL reduced the SWE modeling accuracy since the thermal energy balance and the mass balance were less accurately resolved by the model. Nevertheless, from a performance standpoint, SWE modeling can be accurate enough with a MNSL of two (2), with a substantial performance drop for a MNSL value of around nine (9). Additionally, the linear correlation between the values of the calibrated parameters and the MNSL indicated that reducing the latter in MASiN increased the fresh snow density and the settlement coefficient, while the maximum radiation coefficient decreased. In this case, MASiN favored the melting process, and thus the homogenization of snow layers occurred from the top layers of the snowpack in the modeling algorithm.

APA, Harvard, Vancouver, ISO, and other styles

11

Bargaoui, Zoubeïda, Hamouda Dakhlaoui, and Ahmed Houcine. "Modélisation pluie-débit et classification hydroclimatique." Revue des sciences de l'eau 21, no. 2 (2008): 233–45. http://dx.doi.org/10.7202/018468ar.

Full text

Abstract:

Résumé La recherche de similarité hydrologique est très importante pour l’estimation des débits aux bassins non jaugés. L’indice radiatif d’aridité, proposé dans le modèle de bilan hydrique de Budyko, en combinaison avec le bilan radiatif, représente un paramètre de contrôle de l’ETR (évapotranspiration réelle). Cet indice permet de définir des régions climatiques ou géobotaniques dans lesquelles s’inscrivent les modèles pluie-débit ajustés d’après des historiques d’observations hydroclimatiques. Le présent travail utilise le modèle HBV muni d’une routine d’optimisation à l’aide de l’algorithme SCE‑UA. Il propose une méthodologie de calage dans laquelle on tient explicitement compte de l’ETR établie à grande échelle, à partir de l’indice d’aridité. Cette méthode de calage adopte comme fonction objective la combinaison de trois critères : minimisation de l’écart quadratique sur les débits, minimisation de l’écart sur le bilan hydrique, minimisation de l’écart à l’ETR régionale. On montre qu’ainsi, on améliore la performance du modèle en période de validation.

APA, Harvard, Vancouver, ISO, and other styles

12

van Dalum, Christiaan T., Willem Jan van de Berg, Quentin Libois, Ghislain Picard, and Michiel R. van den Broeke. "A module to convert spectral to narrowband snow albedo for use in climate models: SNOWBAL v1.2." Geoscientific Model Development 12, no. 12 (2019): 5157–75. http://dx.doi.org/10.5194/gmd-12-5157-2019.

Full text

Abstract:

Abstract. Snow albedo schemes in regional climate models often lack a sophisticated radiation penetration scheme and generally compute only a broadband albedo. Here, we present the Spectral-to-NarrOWBand ALbedo module (SNOWBAL, version 1.2) to couple effectively a spectral albedo model with a narrowband radiation scheme. Specifically, the Two-streAm Radiative TransfEr in Snow model (TARTES) is coupled with the European Centre for Medium-Range Weather Forecasts (ECMWF) Integrated Forecast System (IFS), cycle 33R1, atmospheric radiation scheme based on the Rapid Radiation Transfer Model, which is embedded in the Regional Atmospheric Climate Model version 2.3p2 (RACMO2). This coupling allows to explicitly account for the effect of clouds, water vapor, snow impurities and snow metamorphism on albedo. Firstly, we present a narrowband albedo method to project the spectral albedos of TARTES onto the 14 spectral bands of the IFS shortwave radiation scheme using a representative wavelength (RW) for each band. Using TARTES and spectral downwelling surface irradiance derived with the DIScrete Ordinate Radiative Transfer atmospheric model, we show that RWs primarily depend on the solar zenith angle (SZA), cloud content and water vapor. Secondly, we compare the TARTES narrowband albedo, using offline RACMO2 results for south Greenland, with the broadband albedo parameterizations of Gardner and Sharp (2010), currently implemented in RACMO2, and the multi-layered parameterization of Kuipers Munneke et al. (2011, PKM). The actual absence of radiation penetration in RACMO2 leads on average to a higher albedo compared with TARTES narrowband albedo. Furthermore, large differences between the TARTES narrowband albedo and PKM and RACMO2 are observed for high SZA and clear-sky conditions, and after melt events when the snowpack is very inhomogeneous. This highlights the importance of accounting for spectral albedo and radiation penetration to simulate the energy budget of the Greenland ice sheet.

APA, Harvard, Vancouver, ISO, and other styles

13

Oleinik, A. S., S. V. Piskarev, and E. A. Ryzhkov. "An optical radiation module." Measurement Techniques 35, no. 12 (1992): 1399–401. http://dx.doi.org/10.1007/bf00976882.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Ogbonnaya, Chukwuma, Chamil Abeykoon, Adel Nasser, and Ali Turan. "Radiation-Thermodynamic Modelling and Simulating the Core of a Thermophotovoltaic System." Energies 13, no. 22 (2020): 6157. http://dx.doi.org/10.3390/en13226157.

Full text

Abstract:

Thermophotovoltaic (TPV) systems generate electricity without the limitations of radiation intermittency, which is the case in solar photovoltaic systems. As energy demands steadily increase, there is a need to improve the conversion dynamics of TPV systems. Consequently, this study proposes a novel radiation-thermodynamic model to gain insights into the thermodynamics of TPV systems. After validating the model, parametric studies were performed to study the dependence of power generation attributes on the radiator and PV cell temperatures. Our results indicated that a silicon-based photovoltaic (PV) module could produce a power density output, thermal losses, and maximum voltage of 115.68 W cm−2, 18.14 W cm−2, and 36 V, respectively, at a radiator and PV cell temperature of 1800 K and 300 K. Power density output increased when the radiator temperature increased; however, the open circuit voltage degraded when the temperature of the TPV cells increased. Overall, for an 80 W PV module, there was a potential for improving the power generation capacity by 45% if the TPV system operated at a radiator and PV cell temperature of 1800 K and 300 K, respectively. The thermal efficiency of the TPV system varied with the temperature of the PV cell and radiator.

APA, Harvard, Vancouver, ISO, and other styles

15

LIAO Dongjin, 廖东进, 黄志平 HUANG Zhiping, 卢艳 LU Yan, 方晓敏 FANG Xiaomin та 黄云龙 HUANG Yunlong. "双面太阳能组件辐照度模型的优化". ACTA PHOTONICA SINICA 50, № 3 (2021): 140. http://dx.doi.org/10.3788/gzxb20215003.0312003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Wünsch, Richard, Stefanie Walch, František Dinnbier, et al. "Tree-based solvers for adaptive mesh refinement code flash – II: radiation transport module TreeRay." Monthly Notices of the Royal Astronomical Society 505, no. 3 (2021): 3730–54. http://dx.doi.org/10.1093/mnras/stab1482.

Full text

Abstract:

ABSTRACT The treatment of radiative transfer with multiple radiation sources is a critical challenge in simulations of star formation and the interstellar medium (ISM). In this paper, we present the novel TreeRay method for solving general radiative transfer problems, based on reverse ray-tracing combined with tree-based accelerated integration. We implement TreeRay in the adaptive mesh refinement code flash, as a module of the tree solver developed by Wünsch et al. However, the method itself is independent of the host code and can be implemented in any grid-based or particle-based hydrodynamics code. A key advantage of TreeRay is that its computational cost is independent of the number of sources, making it suitable for simulations with many point sources (e.g. massive star clusters) as well as simulations where diffuse emission is important. A very efficient communication and tree-walk strategy enable TreeRay to achieve almost ideal parallel scalings. TreeRay can easily be extended with sub-modules to treat radiative transfer at different wavelengths and to implement related physical processes. Here, we focus on ionizing radiation and use the on-the-spot approximation to test the method and its parameters. The ability to set the tree solver time-step independently enables the speedy calculation of radiative transfer in a multiphase ISM, where the hydrodynamic time-step is typically limited by the sound speed of the hot gas produced in stellar wind bubbles or supernova remnants. We show that complicated simulations of star clusters with feedback from multiple massive stars become feasible with TreeRay.

APA, Harvard, Vancouver, ISO, and other styles

17

Vintila, Ruxandra. "Kalideos Adam : Synthèse et retour d'expérience." Revue Française de Photogrammétrie et de Télédétection, no. 197 (April 22, 2014): 112–18. http://dx.doi.org/10.52638/rfpt.2012.87.

Full text

Abstract:

Le projet de recherche ADAM a été une coopération scientifique entre la France et la Roumanie dédiée à l'Assimilation de Données spatiales par Agro-Modélisation, dont le promoteur et commanditaire a été le Centre National d'Études Spatiales. Le papier présente les principales approches utilisées et les résultats novateurs obtenus dans ADAM: constitution de la première base de données de télédétection de référence, production d'une série temporelle d'images Spot XS de haute qualité, méthode de suivi de l'humidité surfacique du sol au long du cycle cultural à partir d'imagesradar, définition de la fréquence optimale de revisite pour l'agriculture à l'échelle de la parcelle, développement d'une stratégie performante d'assimilation variationnelle de données spatiales dans les modèles de fonctionnement du couvert végétal, calcul du modèle adjoint d'un modèle complexe de fonctionnement par différentiation automatique, améliorationde la modélisation du transfert radiatif par la prise en compte de l'agrégation des feuilles dans le couvert (modèle CLAMP).

APA, Harvard, Vancouver, ISO, and other styles

18

Ивашкин, A. Ivashkin, Новиков, et al. "Calculation Model of Photochemical Reactor with a Pulse Xenon Lamp for Water Treatment." Safety in Technosphere 5, no. 4 (2016): 51–57. http://dx.doi.org/10.12737/23762.

Full text

Abstract:

A calculation model of the photochemical reactor based on a pulse xenon lamp and intended for water treatment from microbiological or chemical pollutants has been developed and realized. The model includes several calculation modules, each one describes the basic physical processes ongoing in the photochemical reactor: current’s form calculation module, pollutant’s particles trajectories calculation module, pulse lamp’s radiating characteristics calculation module, module for photometric calculation, determining an energy radiation dose of pollutant particles. Calculation of lamp’s radiating characteristics is based on ideas of gas discharge physics and on a number of empirical dependences, for calculation of other parameters has been used the numerical simulation. Model verification has been carried out by comparison of calculated and experimental efficiencies for two types of photochemical reactors’ designs with use of the known pollutant. The developed calculation model allows perform multi-parameter optimization for designs and regime parameters of pulse photochemical reactors for the purpose of increase their energy efficiency, and level of water treatment from various chemical and biological pollutants.

APA, Harvard, Vancouver, ISO, and other styles

19

De Ceuster, Frederik, Ward Homan, Jeremy Yates, Leen Decin, Peter Boyle, and James Hetherington. "magritte, a modern software library for 3D radiative transfer: I. Non-LTE atomic and molecular line modelling." Monthly Notices of the Royal Astronomical Society 492, no. 2 (2019): 1812–26. http://dx.doi.org/10.1093/mnras/stz3557.

Full text

Abstract:

ABSTRACT Radiative transfer is a key component in almost all astrophysical and cosmological simulations. We present magritte: a modern open-source software library for 3D radiative transfer. It uses a deterministic ray-tracer and formal solver, i.e. it computes the radiation field by tracing rays through the model and solving the radiative transfer equation in its second-order form along a fixed set of rays originating from each point. magritte can handle structured and unstructured input meshes, as well as smoothed-particle hydrodynamics (SPH) particle data. In this first paper, we describe the numerical implementation, semi-analytic tests and cross-code benchmarks for the non-LTE line radiative transfer module of magritte. This module uses the radiative transfer solver to self-consistently determine the populations of the quantized energy levels of atoms and molecules using an accelerated Lambda iteration (ALI) scheme. We compare magritte with the established radiative transfer solvers ratran (1D) and lime (3D) on the van Zadelhoff benchmark and present a first application to a simple Keplerian disc model. Comparing with lime, we conclude that magritte produces more accurate and more precise results, especially at high optical depth, and that it is faster.

APA, Harvard, Vancouver, ISO, and other styles

20

Ayash, Tarek, Sunling Gong, and Charles Q. Jia. "Direct and Indirect Shortwave Radiative Effects of Sea Salt Aerosols." Journal of Climate 21, no. 13 (2008): 3207–20. http://dx.doi.org/10.1175/2007jcli2063.1.

Full text

Abstract:

Abstract Sea salt aerosols play a dual role in affecting the atmospheric radiative balance. Directly, sea salt particles scatter the incoming solar radiation and absorb the outgoing terrestrial radiation. By acting as cloud condensation nuclei, sea salt aerosols indirectly modulate the atmospheric radiative budget through their effective contribution to cloud formation. Using the Canadian Aerosol Module (CAM)–Canadian Centre for Climate Modelling and Analysis (CCCma) GCM, version 3 (GCM3) framework, the direct as well as the indirect shortwave (SW) radiative effects of sea salt aerosols are simulated. The model results herein suggest that sea salt aerosols exert a significant direct radiative effect over oceanic regions, with seasonal means in the range from −2 to −3 W m−2 over the Southern Ocean. Globally, sea salt’s SW indirect effect (annual mean −0.38 W m−2) is found to be less than its direct effect (annual mean −0.65 W m−2). However, sea salt’s indirect effect is found to be far stronger over the Southern Hemisphere than over the Northern Hemisphere, especially over the Southern Ocean with seasonal means around −4 W m−2, which exceed its direct effect. The model results herein suggest that sea salt aerosols significantly modulate the atmospheric radiation budget over oceanic regions and need to be accounted for in global climate models.

APA, Harvard, Vancouver, ISO, and other styles

21

Alexander, P. M., M. Tedesco, X. Fettweis, R. S. W. van de Wal, C. J. P. P. Smeets, and M. R. van den Broeke. "Assessing spatio-temporal variability and trends (2000–2013) of modelled and measured Greenland ice sheet albedo." Cryosphere Discussions 8, no. 4 (2014): 3733–83. http://dx.doi.org/10.5194/tcd-8-3733-2014.

Full text

Abstract:

Abstract. Accurate measurements and simulations of Greenland Ice Sheet (GrIS) surface albedo are essential, given the crucial role of surface albedo in modulating the amount of absorbed solar radiation and meltwater production. In this study, we assess the spatio-temporal variability of GrIS albedo (during June, July, and August) for the period 2000–2013. We use two remote sensing products derived from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS), as well as outputs from the Modèle Atmosphérique Régionale (MAR) regional climate model (RCM) and data from in situ automatic weather stations. Our results point to an overall consistency in spatiotemporal variability between remote sensing and RCM albedo, but reveal a difference in mean albedo of up to ~0.08 between the two remote sensing products north of 70° N. At low elevations, albedo values simulated by the RCM are positively biased with respect to remote sensing products and in situ measurements by up to ~0.1 and exhibit low variability compared with observations. We infer that these differences are the result of a positive bias in simulated bare-ice albedo. MODIS albedo, RCM outputs and in situ observations consistently point to a~decrease in albedo of −0.03 to −0.06 per decade over the period 2003–2013 for the GrIS ablation zone (where there is a net loss of mass at the GrIS surface). Nevertheless, satellite products show a~decline in albedo of −0.03 to −0.04 per decade for regions within the accumulation zone (where there is a net gain of mass at the surface) that is not confirmed by either the model or in situ observations.

APA, Harvard, Vancouver, ISO, and other styles

22

Wang, Hao, Tie Dai, Min Zhao, et al. "Aerosol Effective Radiative Forcing in the Online Aerosol Coupled CAS-FGOALS-f3-L Climate Model." Atmosphere 11, no. 10 (2020): 1115. http://dx.doi.org/10.3390/atmos11101115.

Full text

Abstract:

The effective radiative forcing (ERF) of anthropogenic aerosol can be more representative of the eventual climate response than other radiative forcing. We incorporate aerosol–cloud interaction into the Chinese Academy of Sciences Flexible Global Ocean–Atmosphere–Land System (CAS-FGOALS-f3-L) by coupling an existing aerosol module named the Spectral Radiation Transport Model for Aerosol Species (SPRINTARS) and quantified the ERF and its primary components (i.e., effective radiative forcing of aerosol-radiation interactions (ERFari) and aerosol-cloud interactions (ERFaci)) based on the protocol of current Coupled Model Intercomparison Project phase 6 (CMIP6). The spatial distribution of the shortwave ERFari and ERFaci in CAS-FGOALS-f3-L are comparable with that of most available CMIP6 models. The global mean 2014–1850 shortwave ERFari in CAS-FGOALS-f3-L (−0.27 W m−2) is close to the multi-model means in 4 available models (−0.29 W m−2), whereas the assessing shortwave ERFaci (−1.04 W m−2) and shortwave ERF (−1.36 W m−2) are slightly stronger than the multi-model means, illustrating that the CAS-FGOALS-f3-L can reproduce the aerosol radiation effect reasonably well. However, significant diversity exists in the ERF, especially in the dominated component ERFaci, implying that the uncertainty is still large.

APA, Harvard, Vancouver, ISO, and other styles

23

Alexander, P. M., M. Tedesco, X. Fettweis, R. S. W. van de Wal, C. J. P. P. Smeets, and M. R. van den Broeke. "Assessing spatio-temporal variability and trends in modelled and measured Greenland Ice Sheet albedo (2000–2013)." Cryosphere 8, no. 6 (2014): 2293–312. http://dx.doi.org/10.5194/tc-8-2293-2014.

Full text

Abstract:

Abstract. Accurate measurements and simulations of Greenland Ice Sheet (GrIS) surface albedo are essential, given the role of surface albedo in modulating the amount of absorbed solar radiation and meltwater production. In this study, we assess the spatio-temporal variability of GrIS albedo during June, July, and August (JJA) for the period 2000–2013. We use two remote sensing products derived from data collected by the Moderate Resolution Imaging Spectroradiometer (MODIS), as well as outputs from the Modèle Atmosphérique Régionale (MAR) regional climate model (RCM) and data from in situ automatic weather stations. Our results point to an overall consistency in spatio-temporal variability between remote sensing and RCM albedo, but reveal a difference in mean albedo of up to ~0.08 between the two remote sensing products north of 70° N. At low elevations, albedo values simulated by the RCM are positively biased with respect to remote sensing products by up to ~0.1 and exhibit low variability compared with observations. We infer that these differences are the result of a positive bias in simulated bare ice albedo. MODIS albedo, RCM outputs, and in situ observations consistently indicate a decrease in albedo of −0.03 to −0.06 per decade over the period 2003–2013 for the GrIS ablation area. Nevertheless, satellite products show a decline in JJA albedo of −0.03 to −0.04 per decade for regions within the accumulation area that is not confirmed by either the model or in situ observations. These findings appear to contradict a previous study that found an agreement between in situ and MODIS trends for individual months. The results indicate a need for further evaluation of high elevation albedo trends, a reconciliation of MODIS mean albedo at high latitudes, and the importance of accurately simulating bare ice albedo in RCMs.

APA, Harvard, Vancouver, ISO, and other styles

24

Dunne-Daly, Carrie F. "External Radiation Therapy Self-Learning Module." Cancer Nursing 17, no. 2 (1994): 156???169. http://dx.doi.org/10.1097/00002820-199404000-00010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Pietras-Szewczyk, Małgorzata. "A GIS Open Source Software application for mapping solar energy resources in urban areas." E3S Web of Conferences 116 (2019): 00060. http://dx.doi.org/10.1051/e3sconf/201911600060.

Full text

Abstract:

This paper presents the development of an open source geographical information system (GIS) software module for mapping solar energy resources for urban areas. The main goal of this work is to demonstrate the potential use of the r.sun module, a component of GRASS software, in calculating real solar radiation for urban areas. Modelling of the spatial distribution of solar radiation is one of the program functions. The r.sun module is dedicated for that purpose; however, it can only generate the spatial distribution of potential solar radiation. To get the real solar radiation maps it is advisable to use meteorological data, that describe diminution of solar radiation caused by cloud cover. In order to facilitate the generation of maps a GRASS source code modification was made. As a result, the r.sun module used in this work generates the real spatial distribution of solar radiation. The results are shown to be comparable with solar radiation satellite data obtained from the HelioClim project.

APA, Harvard, Vancouver, ISO, and other styles

26

Crews, Francesca Lima, Emilly Rayane Santos Oliveira, Willames Albuquerque Soares, José Romualdo Souza Lima, and Antônio Celso Dantas Antonino. "Análise comparativa de modelos matemáticos para estimativas do saldo de radiação em áreas de pastagens." Revista Brasileira de Geografia Física 10, no. 6 (2017): 1889–97. http://dx.doi.org/10.26848/rbgf.v10.6.p1889-1897.

Full text

APA, Harvard, Vancouver, ISO, and other styles

27

Eldehn, Israa F., M. M. Mustafa, M. Elnono, and A. Hegazi. "INFLUENCE OF SOLAR RADIATION AND MODULE TEMPERATURE ON SOLAR MODULE PERFORMANCE." Misr Journal of Agricultural Engineering 33, no. 3 (2016): 789–804. http://dx.doi.org/10.21608/mjae.2016.97724.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Liu, Chun Yu, and Hai Tao Zhou. "Design on Optimization Database of Radiation Protection for Nuclear Facilities Maintenance." Advanced Materials Research 608-609 (December 2012): 835–38. http://dx.doi.org/10.4028/www.scientific.net/amr.608-609.835.

Full text

Abstract:

The optimization database of radiation protection was designed on nuclear facilities maintenance with SQL Server 2008 in this paper. The database includes four modules, namely system login module, statistical data module, daily module and optimization module. Twenty-three data tables were designed, which could store a mass of data in orderly. The optimization database of radiation protection on nuclear facilities maintenance could store the original monitoring data such as plant radiation levels measurement figure on nuclear facilities for maintenance and maintenance daily. This database also combines with the actual demand in the engineering project to statistics and analysis the data.

APA, Harvard, Vancouver, ISO, and other styles

29

Guo, H., Y. Liu, P. H. Daum, X. Zeng, X. Li, and W. K. Tao. "Effects of model resolution on entrainment (inversion heights), cloud-radiation interactions, and cloud radiative forcing." Atmospheric Chemistry and Physics Discussions 8, no. 6 (2008): 20399–425. http://dx.doi.org/10.5194/acpd-8-20399-2008.

Full text

Abstract:

Abstract. We undertook three-dimensional numerical studies of a marine stratus deck under a strong inversion using an interactive shortwave- and longwave-radiation module. A suite of sensitivity tests were conducted to address the effects of model resolution on entrainment (inversion heights), cloud-radiation interactions, and cloud radiative-forcings by varying model horizontal resolution only, varying vertical resolution only, and varying horizontal- and vertical-resolution simultaneously but with a fixed aspect ratio of 2.5. Our results showed that entrainment (inversion height) is more sensitive to vertical- than to horizontal-resolution. A vertical resolution finer than 40 m can simulate spatial- and temporal-variations in the inversion height well. The inversion height decreases with increasing vertical resolution, but tends to increase with increasing horizontal resolution. Cloud liquid water path doubles after refining both the vertical- and horizontal-resolution by a factor of four. This doubling is associated with a positive feedback between cloud water and cloud top radiative cooling, which amplifies small differences initiated by changes in the model resolution. The magnitude of the cloud radiative-forcing tends to increase with increasing model resolution, mainly attributable to the increase in the cloud liquid water path. Shortwave radiative forcing is dominant, and more sensitive to model resolution than the longwave counterpart.

APA, Harvard, Vancouver, ISO, and other styles

30

Belaed, Marwan, and Muhammad Mustafizur Rahman. "Enhancement of Energy Recovery in a Phase Change Energy Storage Module with Embedded Radiation Absorbing Particles." Journal of Clean Energy Technologies 8, no. 3 (2020): 24–30. http://dx.doi.org/10.18178/jocet.2020.8.3.521.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Calderón, Diego, Ondřej Pejcha, and Paul C. Duffell. "Moving-mesh radiation-hydrodynamic simulations of wind-reprocessed transients." Monthly Notices of the Royal Astronomical Society 507, no. 1 (2021): 1092–105. http://dx.doi.org/10.1093/mnras/stab2219.

Full text

Abstract:

ABSTRACT Motivated by recent theoretical work on tidal disruption events and other peculiar transients, we present moving-mesh radiation-hydrodynamic simulations of radiative luminosity emitted by a central source being reprocessed by a wind-like outflow. We couple the moving-mesh hydrodynamic code jet with our newly developed radiation module based on mixed-frame grey flux-limited diffusion with implicit timestep update. This allows us to study the self-consistent multidimensional radiation-hydrodynamic evolution over more than 10 orders of magnitude in both space and time in a single run. We simulate an optically thick spherical wind with constant or evolving mass-loss rate, which is irradiated by a central isotropic or angularly dependent radiation source. Our spherically symmetric simulations confirm previous analytic results by identifying different stages of radiation reprocessing: radiation trapped in the wind, diffusing out through the wind, and reaching constant maximum attenuation. We find that confining the central radiation source in a cone with moderate opening angles decrease up to one order of magnitude the early flux along sightlines oriented away from the direction of radiation injection but that the reprocessed radiation becomes isotropic roughly after one lateral diffusion time through the ejecta. We discuss further applications and guidelines for the use of our novel radiation-hydrodynamics tool in the context of transient modelling.

APA, Harvard, Vancouver, ISO, and other styles

32

Pradhan, Arjyadhara, and Bhagbat Panda. "Experimental Analysis of Factors Affecting the Power Output of the PV Module." International Journal of Electrical and Computer Engineering (IJECE) 7, no. 6 (2017): 3190. http://dx.doi.org/10.11591/ijece.v7i6.pp3190-3197.

Full text

Abstract:

Energy is the driving force in all the sectors as it acts like an index of standard of living or prosperity of the people of the country. However heavy dependence on fossil fuels leads to global warming, hence there is a need for the use of clean, sustainable, and eco friendly form of energy. Among the various types of non-conventional energy solar energy is the fundamental as it is abundant, pollution free and universally available.Even though the main input to the PV system is the solar radiation still there are other factors which affects the efficiency of the pv module. In this paper real time experiment has been conducted to analyze the effect of various factors like irradiance, temperature, and angle of tilt, soiling, shading on the power output of the pv module. Temperature is a negative factor which reduces the efficiency of the module and can be reduced by various cooling arrangements. Presence of dust particles and shading obstructs the incident solar radiations entering the panel and the effect is seen in the iv and pv curve .For better performance solar tracking at maximum power point is suggested to improve the power output of the pv module.

APA, Harvard, Vancouver, ISO, and other styles

33

Dürr, Bruno, Rolf Philipona, Francis Schubiger, and Atsumu Ohmura. "Comparison of modeled and observed cloud-free longwave downward radiation over the Alps." Meteorologische Zeitschrift 14, no. 1 (2005): 47–55. http://dx.doi.org/10.1127/0941-2948/2005/0014-0047.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Simon, Helge, Tim Sinsel, and Michael Bruse. "Introduction of Fractal-Based Tree Digitalization and Accurate In-Canopy Radiation Transfer Modelling to the Microclimate Model ENVI-met." Forests 11, no. 8 (2020): 869. http://dx.doi.org/10.3390/f11080869.

Full text

Abstract:

While complex urban morphologies including different materials, wall structures, etc., are rather adequately represented in microclimate models, replication of actual plant geometry is—so far—rather crudely handled. However, plant geometry greatly differs within species and locations while strongly determining a plant’s microclimate performance. To improve the plants representation in numerical models, a new method to describe plant skeletons using the so-called Lindenmayer-System has been implemented in the microclimate model ENVI-met. The new model allows describing much more realistic plants including the position and alignment of leaf clusters, a hierarchical description of the branching system and the calculation of the plant’s biomechanics. Additionally, a new canopy radiation transfer module is introduced that allows not only the simulation of diffuse radiation extinction but also secondary sources of diffuse radiation due to scattering of direct radiation within plant canopies. Intercomparisons between model runs with and without the advancements showed large differences for various plant parameters due to the introduction of the Lindenmayer-System and the advanced radiation scheme. The combination of the two developments represents a sophisticated approach to accurately digitize plants, model radiative transfer in crown canopies, and thus achieve more realistic microclimate results.

APA, Harvard, Vancouver, ISO, and other styles

35

Schwadron, N. A., L. Townsend, K. Kozarev, et al. "Earth-Moon-Mars Radiation Environment Module framework." Space Weather 8, no. 1 (2010): n/a. http://dx.doi.org/10.1029/2009sw000523.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Balter, Stephen. "What is radiation dose? A tutorial module." Catheterization and Cardiovascular Diagnosis 45, no. 1 (1998): 76–81. http://dx.doi.org/10.1002/(sici)1097-0304(199809)45:1<76::aid-ccd18>3.0.co;2-j.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Pyles, Jennifer M., Adriana V. F. Massicano, Jean-Pierre Appiah, Jennifer L. Bartels, Aaron Alford, and Suzanne E. Lapi. "Production of 52Mn using a semi-automated module." Applied Radiation and Isotopes 174 (August 2021): 109741. http://dx.doi.org/10.1016/j.apradiso.2021.109741.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Mignon-Risse, R., M. González, B. Commerçon, and J. Rosdahl. "A new hybrid radiative transfer method for massive star formation." Astronomy & Astrophysics 635 (March 2020): A42. http://dx.doi.org/10.1051/0004-6361/201936605.

Full text

Abstract:

Context. Frequency-dependent and hybrid approaches for the treatment of stellar irradiation are of primary importance in numerical simulations of massive star formation. Aims. We seek to compare outflow and accretion mechanisms in star formation simulations. We investigate the accuracy of a hybrid radiative transfer method using the gray M1 closure relation for proto-stellar irradiation and gray flux-limited diffusion (FLD) for photons emitted everywhere else. Methods. We have coupled the FLD module of the adaptive-mesh refinement code RAMSES with RAMSES-RT, which is based on the M1 closure relation and the reduced speed-of-light-approximation. Our hybrid (M1+FLD) method takes an average opacity at the stellar temperature for the M1 module, instead of the local environmental radiation field. Due to their construction, the opacities are consistent with the photon origin. We have tested this approach in radiative transfer tests of disks irradiated by a star for three levels of optical thickness and compared the temperature structure with the radiative transfer codes RADMC-3D and MCFOST. We applied it to a radiation-hydrodynamical simulation of massive star formation. Results. Our tests validate our hybrid approach for determining the temperature structure of an irradiated disk in the optically-thin (2% maximal error) and moderately optically-thick (error smaller than 25%) regimes. The most optically-thick test shows the limitation of our hybrid approach with a maximal error of 65% in the disk mid-plane against 94% with the FLD method. The optically-thick setups highlight the ability of the hybrid method to partially capture the self-shielding in the disk while the FLD alone cannot. The radiative acceleration is ≈100 times greater with the hybrid method than with the FLD. The hybrid method consistently leads to about + 50% more extended and wider-angle radiative outflows in the massive star formation simulation. We obtain a 17.6 M⊙ star at t ≃ 0.7τff, while the accretion phase is still ongoing, with a mean accretion rate of ≃7 × 10−4 M⊙ yr−1. Finally, despite the use of refinement to resolve the radiative cavities, no Rayleigh–Taylor instability appears in our simulations, and we justify their absence by physical arguments based on the entropy gradient.

APA, Harvard, Vancouver, ISO, and other styles

39

Suprianto, Marlon Tua Pangihutan Sibarani, Febrin, and Aulia Batubara. "Influence of the Intensity of the Solar Radiation and the Surface Area of Photovoltaic Module Towards the Electricity Generated by Photovoltaic Module." Journal of Computational and Theoretical Nanoscience 17, no. 7 (2020): 3126–31. http://dx.doi.org/10.1166/jctn.2020.9148.

Full text

Abstract:

The intensity of the solar radiation and the surface area of the photovoltaic module directly influence the amounts of electricity produced by the photovoltaic module. This needs to be known to determine the design of an effective solar power system for the use of electricity from solar energy sources. This research aims to determine the influence of the intensity of solar radiation and the area of the photovoltaic module on the performance of the photovoltaic module in producing current and voltage to be distributed to charge the battery. The method used in this research is an experimental method that measures the current and voltage of the photovoltaic module, the intensity of the solar radiation, the temperature, and the surface area of the photovoltaic module the equipment used is 600 Wp photovoltaic module, ammeter, voltmeter, luxmeter, solar charge controller, batteries and temperature gauges. Results of the research show the intensity of the solar radiation is directly proportional to the battery charging current. The intensity of the solar radiation up to 10000 lux produces a charging current on a 100 Ah 12 volt battery that is 0 to 1.55 Amperes, for 10000 lux to 60000 lux produces 1.6 to 8.35 A, for 60000 lux to 90000 lux produces 9 to 14 A and for above 90000 lux produces 14 to 19 A. The ratio of the surface area of the photovoltaic module is proportional to the ratio of the battery charging current and the increase in battery voltage. Photovoltaic modules with a surface area ratio of 1:2:3, produce a battery charging current and voltage that is 1:2:2.7 and 1:2.1:3.1. Comparison of the amount of electricity produced by a photovoltaic module is proportional to the ratio of the surface area of a photovoltaic module if the measurements are made at the same place and time, at the same scc (solar charge controller) and at the same initial voltage of the battery.

APA, Harvard, Vancouver, ISO, and other styles

40

Pantic, Lana, and Tomislav Pavlovic. "Determination of physical characteristics of horizontally positioned solar module in real climate conditions in Nis, Serbia." Facta universitatis - series: Physics, Chemistry and Technology 14, no. 1 (2016): 37–51. http://dx.doi.org/10.2298/fupct1601037p.

Full text

Abstract:

The aim of this paper was to investigate the influence of solar radiation intensity, ambient temperature, wind speed and solar module temperature on the modules physical characteristics, in local climate conditions and for all seasons in Nis, Serbia. Twelve sunny days, for each month of the year, from the period September 2014 - June 2016 were selected. During each day meteorological parameters, solar module temperature and solar module output parameters were measured. The highest values of solar radiation intensity, ambient temperature and solar module temperature were measured in summer months, while the lowest values were in winter months. The maximal values of the output power were measured in summer months due to the high values of solar radiation intensity on the solar modules surface. A negative impact of high solar module temperature on the open circuit voltage, the output power, the fill factor and the efficiency was observed. In the winter months the local climatic conditions and air pollution have an adverse impact on the solar module efficiency and lead to a noticeable reduction of the efficiency.

APA, Harvard, Vancouver, ISO, and other styles

41

Marki, Antun, and Oleg Antonić. "Ganzjahresmodelle für die Monatsmittel der Stunden mittel von direkter, diffuser und globaler Sonnenstrahlung am Boden." Meteorologische Zeitschrift 8, no. 3 (1999): 91–95. http://dx.doi.org/10.1127/metz/8/1999/91.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Bonnet, B., R. Chiniard, H. Legay, et al. "Use of 3D Packaging Technology for Satellite Active Antennas Front-ends." International Symposium on Microelectronics 2012, no. 1 (2012): 000554–60. http://dx.doi.org/10.4071/isom-2012-wa14.

Full text

Abstract:

Multi-Chip Module Vertical (MCM-V) technology, also called 3D packaging technology, enables the realization of a compact and low loss integrated feed for active antennas in Ka band. The active devices can be located in the vicinity of the radiating element, which reduces dramatically the volume and complexity of the antenna front-end for future architectures with more than a hundred beams in Ka band. This paper deals with the optimization of 3D packaging technology to reach the requirements of 30GHz microwave modules for space applications. The technological developments that have been led on the design and the assembly processes are detailed. The measurement results of an integrated feed module in radiation are given and the circuit designed to optimize the signal-to-noise ratio of the front-end for receiving antennas is characterized. The performance is as good as for an optimized planar front-end with a waveguide access for a much more compact module, especially in terms of footprint in an antenna array. These results successfully position 3D packaging as a disruptive technology for future space and telecom subsystems.

APA, Harvard, Vancouver, ISO, and other styles

43

Bilčík, Matúš, Monika Božiková, Ana Petrović, et al. "Analysis of Selected Photovoltaic Panels Operating Parameters as a Function of Partial Shading and Intensity of Reflected Radiation." Acta Technologica Agriculturae 21, no. 1 (2018): 14–17. http://dx.doi.org/10.2478/ata-2018-0003.

Full text

Abstract:

AbstractDue to expansion of utilisation of photovoltaics in ordinary households, the question arises how this phenomenon affects the electric power of photovoltaic modules. The article deals with the electric power analysis of photovoltaic modules as a function of two very important factors. The first examined factor was partial shading, and the second factor was the intensity of reflected radiation. In order to determine the dependence of module power on the aforementioned parameters, a measurement system under laboratory conditions has been prepared. For identification of the reflected radiation effect on the power of the photovoltaic module, a series of measurements was performed on 7 different surfaces with the same radiation source. It is evident from obtained experimental result that the ratio of reflected irradiation on the solar module power is 1.29%. By simulation of partial shading of photovoltaic module, the decrease of 86.15% in its output power was identified.

APA, Harvard, Vancouver, ISO, and other styles

44

Sarkar, Kartick C., Amiel Sternberg, and Orly Gnat. "A new ionization network and radiation transport module in pluto." Monthly Notices of the Royal Astronomical Society 503, no. 4 (2021): 5807–25. http://dx.doi.org/10.1093/mnras/stab578.

Full text

Abstract:

ABSTRACT We introduce a new general-purpose time-dependent ionization network (IN) and a radiation transport (RT) module for the magnetohydrodynamic (MHD) code pluto. Our IN is reliable for temperatures ranging from 5 × 103 to 3 × 108 K and includes all ionization states of H, He, C, N, O, Ne, Mg, Si, S, and Fe, making it suitable for studying a variety of astrophysical scenarios. Radiation loss for each ion–electron pair is calculated using cloudy-17 data on the fly. Photoionization and charge exchange are the main processes contributing to chemical heating. The IN is fully coupled to the RT module over a large range of opacities at different frequencies. The RT module employs a method of short characteristics assuming spherical symmetry. The radiation module requires the assumption of spherical symmetry, while the IN is compatible with full 3D. We also include a simple prescription for dust opacity, grain destruction, and the dust contribution to radiation pressure. We present numerical tests to show the reliability and limitations of the new modules. We also present a post-processing tool to calculate projected column densities and emission spectra.

APA, Harvard, Vancouver, ISO, and other styles

45

Хвостиков, В. П., Н. А. Калюжный, С. А. Минтаиров та ін. "Модули фотоэлектрических преобразователей лазерного (λ = 809-850 nm) излучения". Журнал технической физики 90, № 10 (2020): 1764. http://dx.doi.org/10.21883/jtf.2020.10.49811.43-20.

Full text

Abstract:

A high-efficiency photovoltaic module optimized for converting the monochromatic radiation with a wavelength of 809-850 nm is presented. The module comprises four photovoltaic converters with the total area of 16 cm2, which can provide the operating voltage of 4 V in the case of laser power greater than 1 W. The laser power converters are developed on the basis of AlGaAs/GaAs structures grown by LPE and MOVPE. When operating in the uniform illumination mode, the efficiency of the photovoltaic module is found to exceed 60% for the powerful laser radiation (6.2 W).

APA, Harvard, Vancouver, ISO, and other styles

46

Wenxiong, Yang, and Ma Chengwei. "Design and Development of Light Radiation Testing Equipment for Solar Greenhouse." E3S Web of Conferences 136 (2019): 02042. http://dx.doi.org/10.1051/e3sconf/201913602042.

Full text

Abstract:

A solar greenhouse light radiation testing equipment is designed and developed. The equipment consists of five parts: light radiation sensor, angle adjustment module, height adjustment module, data acquisition box and base module. It is easy to move, easy to use, detachable and assembleable, and can accurately obtain the illumination of the solar greenhouse everywhere, so as to help farmers use sunlight scientifically and rationally, precisely plant, and play a role in increasing production and efficiency. The equipment is not available on the market at present and belongs to original design.

APA, Harvard, Vancouver, ISO, and other styles

47

Emetere, M. E., and S. A. Afolalu. "Challenges of small-scale standalone solar energy supply in parts of Lagos via 39 years dataset." E3S Web of Conferences 294 (2021): 01007. http://dx.doi.org/10.1051/e3sconf/202129401007.

Full text

Abstract:

The adoption of solar energy as a sustainable clean type of energy can be seen globally by the patronage of solar devices. However, the high patronage photovoltaic (PV) module by the small-scale standalone user may be mitigated by the recent high maintenance cost via PV module damages by UV radiation. This study analyzed thirty-nine years (1980-2018) shortwave dataset in the tropics to chart the way forward for PV user, manufacturer, and regulatory organizations. It was observed that there is an increase in shortwave radiation in recent times that has led to more damages to PV modules. However, there is a statistical possibility that there may be lower shortwave radiation in the next decade, thereby reducing PV module damage. It is recommended that PV manufacture should modify the PV polymeric to shield the PV modules from UV radiation damage. Based on this research’s finding, it is recommended that product regulatory organizations develop a new technique to monitor PV modules.

APA, Harvard, Vancouver, ISO, and other styles

48

Kim, Joon-Yong, Seung-Hwan Yang, Chun-Gu Lee, et al. "Modeling of Solar Radiation Using Silicon Solar Module." Journal of Biosystems Engineering 37, no. 1 (2012): 11–18. http://dx.doi.org/10.5307/jbe.2012.37.1.011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Masi, A., S. Danzeca, R. Losito, P. Peronnard, R. Secondo, and G. Spiezia. "A high precision radiation-tolerant LVDT conditioning module." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 745 (May 2014): 73–81. http://dx.doi.org/10.1016/j.nima.2014.01.054.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Germain, M., L. Arnold, J. Baudot, et al. "Radiation damages in double-sided silicon strip module." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 485, no. 1-2 (2002): 121–25. http://dx.doi.org/10.1016/s0168-9002(02)00542-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Modèle de radiation'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles