Thematische Bibliographien / Sun elevation

Inhaltsverzeichnis

  1. Zeitschriftenartikel
  2. Dissertationen
  3. Bücher
  4. Buchteile
  5. Konferenzberichte
  6. Berichte der Organisationen

Auswahl der wissenschaftlichen Literatur zum Thema „Sun elevation“

Autor: Grafiati
Veröffentlicht am 28. Juni 2021
Zuletzt aktualisiert am 1. Februar 2022

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Zeitschriftenartikel zum Thema "Sun elevation"

1

Bidschadler, R. A., und P. L. Vornberger. „Detailed elevation map of Ice Stream C, Antarctica, using satellite imagery and airborne radar“. Annals of Glaciology 20 (1994): 327–35. http://dx.doi.org/10.3189/1994aog20-1-327-335.

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Surface elevations collected by airborne radar arc interpolated between flight lines using Landsat I'M image data to produce a detailed digital elevation model of a part of Ice Stream C, West Antarctica. The photodinometric method developed is general and allows the derivation of surface elevation along any line parallel to the solar illumination from a single known elevation on that line. Accuracies of the derived elevations are improved with additional elevation control that permits an empirical determination of parameters in the photoclinometric equation accounting for albedo and atmospheric scattering. Elevation errors increase approximately linearly with the integration distance. An explicit relationship is derived that shows the image brightness is insensitive to the cross-Sun component of small surface slopes typical of ice sheets. The greatest impediment to the accuracy of this technique is the radiance resolution of the sensor which limits the signal-to-noise ratio of the image data and can mask variations in albedo that are falsely converted to variations in surface slope.
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Bidschadler, R. A., und P. L. Vornberger. „Detailed elevation map of Ice Stream C, Antarctica, using satellite imagery and airborne radar“. Annals of Glaciology 20 (1994): 327–35. http://dx.doi.org/10.1017/s0260305500016645.

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Surface elevations collected by airborne radar arc interpolated between flight lines using Landsat I'M image data to produce a detailed digital elevation model of a part of Ice Stream C, West Antarctica. The photodinometric method developed is general and allows the derivation of surface elevation along any line parallel to the solar illumination from a single known elevation on that line. Accuracies of the derived elevations are improved with additional elevation control that permits an empirical determination of parameters in the photoclinometric equation accounting for albedo and atmospheric scattering. Elevation errors increase approximately linearly with the integration distance. An explicit relationship is derived that shows the image brightness is insensitive to the cross-Sun component of small surface slopes typical of ice sheets. The greatest impediment to the accuracy of this technique is the radiance resolution of the sensor which limits the signal-to-noise ratio of the image data and can mask variations in albedo that are falsely converted to variations in surface slope.
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Chen, Y. T., B. H. Lim und C. S. Lim. „General Sun Tracking Formula for Heliostats With Arbitrarily Oriented Axes“. Journal of Solar Energy Engineering 128, Nr. 2 (25.06.2005): 245–50. http://dx.doi.org/10.1115/1.2189868.

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The most general form of solar tracking formulae of an arbitrarily oriented heliostat toward an arbitrarily located target on the Earth is presented. With this complete solution, the used azimuth-elevation, spinning-elevation tracking formula, etc., are the special cases of it. Therefore, more application may be sought out for many individual cases in solar engineering. The new form of tracking solution could bring changes in the geometry and structure of the design of heliostat to meet various requirements.
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Chong, K. K., und M. H. Tan. „Comparison Study of Two Different Sun-Tracking Methods in Optical Efficiency of Heliostat Field“. International Journal of Photoenergy 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/908364.

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There are two sun-tracking methods widely used for the heliostat, which are conventional Azimuth-Elevation and revolutionary Spinning-Elevation methods. Following the previous study to compare the range of motion, a comparison study in optical efficiency of heliostat field for the two methods is further explored in this paper. A special algorithm using ray-tracing technique has also been developed to simulate the optical efficiency of heliostat field for both sun-tracking methods in different latitudes. With the new algorithm, comprehensive analysis to compare the optical efficiency of individual heliostat and the overall heliostat field for the two sun-tracking methods has been carried out.
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Huuskonen, Asko, und Iwan Holleman. „Determining Weather Radar Antenna Pointing Using Signals Detected from the Sun at Low Antenna Elevations“. Journal of Atmospheric and Oceanic Technology 24, Nr. 3 (01.03.2007): 476–83. http://dx.doi.org/10.1175/jtech1978.1.

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Abstract A method to determine the elevation and azimuth biases of the radar antenna using solar signals observed by a scanning radar is presented. Data recorded at low elevation angles where the atmospheric refraction has a significant effect on the propagation of the radio wave are used, and a method to take the effect of the refraction into account in the analysis is presented. A set of equations is given by which the refraction of the radio waves as a function of the relative humidity can easily be calculated. Also, a simplified model for the calculation of the atmospheric attenuation is presented. The consistency of the adopted models for the atmospheric refraction and atmospheric attenuation is confirmed by data collected at a single elevation pointing, but over a long observing time. Finally, the method is applied to datasets based on operational measurements at the Finnish Meteorological Institute (FMI) and Royal Netherlands Meteorological Institute (KNMI), and elevation and azimuth biases of the radars are shown.
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Reimann, Jens, und Martin Hagen. „Antenna Pattern Measurements of Weather Radars Using the Sun and a Point Source“. Journal of Atmospheric and Oceanic Technology 33, Nr. 5 (Mai 2016): 891–98. http://dx.doi.org/10.1175/jtech-d-15-0185.1.

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AbstractThe sun is known to be a good target for weather radar calibration. In this paper high-resolution raster scans of the sun at high elevations will be used to derive the antenna pattern of weather radar, without being affected by beam propagation effects and reflections close to the earth’s surface. It is shown that this pattern matches well to pattern measurements using a point source. Hence, a good estimation of the real antenna pattern can be derived using the sun.Furthermore, formulas to extract undistorted antenna patterns from the sun, even at high-elevation angles, are derived. The signal processing required to achieve high sensitivity for the antenna pattern measurements will be described. Important parts of the antenna pattern—for example, sidelobes—become visible when using long integration times.The polarimetric receiver channel cross-correlation coefficient is proposed as a figure of merit of the cross-polar isolation of the antenna and hence the cross-polar pattern. The results are also compared to point source measurements. This illustrates how an unpolarized signal source like the sun can be used to derive polarimetric variables.
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Liu, Chao, und Jing Hui. „Research on Physical MPPT of Photovoltaic Array System Based on Image Processing“. Applied Mechanics and Materials 321-324 (Juni 2013): 1138–44. http://dx.doi.org/10.4028/www.scientific.net/amm.321-324.1138.

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Based on analyzing the development and the performance feature of existing solar tracker, we propose a solar Maximum Power Point Tracking (MPPT) strategy which combines photoelectric sensor and image processing. Firstly, photoelectric tracking mode positions the sun in the field of view of the image sensor. Then, the position of the sun image is captured by the image sensor. After that, we can find the coordinates of the sun spot in the field of view through image binarization processing. According to the number of steps of stepper motor rotation which is calculated by the deviation of coordinates, the controller drives the biaxial photosensitive (PV) array tracking device, making the sun spot always fall in the centre of the image. Tests show that the elevation angle and azimuth angle of the tracking range of the photovoltaic array are both 0～270°.The average tracking error of elevation angle is less than 0.7°, and the average tracking error of azimuth angle is less than 0.5°.
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Igoe, D. P., und A. V. Parisi. „Solar current output as a function of sun elevation: students as toolmakers“. Physics Education 50, Nr. 6 (Oktober 2015): 657–61. http://dx.doi.org/10.1088/0031-9120/50/6/657.

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Martha, Tapas R., Norman Kerle, Cees J. van Westen, Victor Jetten und K. Vinod Kumar. „Effect of Sun Elevation Angle on DSMs Derived from Cartosat-1 Data“. Photogrammetric Engineering & Remote Sensing 76, Nr. 4 (01.04.2010): 429–38. http://dx.doi.org/10.14358/pers.76.4.429.

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Peart, David R., Matthew B. Jones und Peter A. Palmiotto. „Winter injury to red spruce at Mount Moosilauke, New Hampshire“. Canadian Journal of Forest Research 21, Nr. 9 (01.09.1991): 1380–89. http://dx.doi.org/10.1139/x91-195.

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We report the severity and detailed spatial patterns of winter injury to red spruce (Picearubens Sarg.) in the winter of 1988–1989 and assess support for the desiccation and freezing hypotheses. Foliar injury was quantified at three elevations (840, 990, and 1140 m) and on east- and west-facing slopes in the spruce-fir zone at Mount Moosilauke, New Hampshire. Overall, 29% of current-year foliage on red spruce trees was killed by winter injury. Injury increased with elevation. There was a weak tendency for winter injury to be higher on the sun-exposed south sides of crowns, but substantial injury also occurred on shaded foliage. Injury increased markedly with height in crown at high elevation, but decreased with height at low elevation. The results appear inconsistent with desiccation as the main cause of winter injury. Elevational trends in foliar injury are consistent with the freezing hypothesis, but the strong trends in foliar injury by height within trees cannot be fully explained without further data on spatial variation in microclimate and freezing tolerance. Failure to break bud was assessed on the same spatial scales as foliar injury. Bud break was least in trees and crown sections with severe foliar injury. No evidence for winter injury was found on balsam fir (Abiesbalsamea (L.) Mill.). The results support the hypothesis that winter injury may contribute to the current decline of red spruce in the northern Appalachians.
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Dissertationen zum Thema "Sun elevation"

1

Uher, Ondřej. „Servomechanické řízení pohybu fotovoltaických panelů“. Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229662.

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Thesis deals with the introduction to the production of electricity using photovoltaic panels and the relative position between panels and the Sun. The project aim was to design equipment to ensure the vertical position of the solar panels towards the Sun during the day so as to achieve maximum energy gain from sunlight. Pointing mechanism will be governed by the date and time.
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Castle, Sarah Christine. „Plant-nutrient dynamics in high elevation forests of the southern San Juan Mountains, Colorado, USA“. Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1453520.

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Spyropoulou, Katerina Dimitris 1977. „Interpretation of tectonics from digital elevation data in the San Gabriel Mountains, CA : evaluation of methods and data sources“. Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/34350.

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Thesis (S.M. in Geosystems)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2003.
Includes bibliographical references (leaves 34-36).
The identifiable pattern of the qualitative geomorphologic parameters such as steepness and concavity values that derived from the slope-area analysis of 28 tributaries in the San Gabriel Mountains were used to estimate relative rock uplift rates. The results suggest that the eastern region of the San Gabriel Mountain is controlled by a high rock uplift rate while the western region is controlled by a low rock uplift rate. Furthermore, arrangement of the variations of the steepness and concavity values suggests the presence of an active fault zone between the western and the eastern region of the San Gabriel Mountains. This tectonic zone is responsible for the apparent differentiation in rock uplift rates between the two mountain regions. This conclusion is supported from previous knowledge that suggests faster exhumation and high erosion rates of the East San Gabriel (ESG) block and slower exhumation and lower erosion rates of the Western San Gabriel (WSG) block (Spotila, J., Blythe, A., House, M., Niemi, N., Gregory, B., 2002). Moreover on the technological side of this project, plots of steepness or concavity values derived from analysis of SRTM (30 meter resolution), ASTER (30 meter resolution), USGS (30 meter resolution) and USGS (10 meter resolution) DEMs analysis suggest that USGS DEM-10 meters and SRTM DEM-30 meters are currently the most accurate methods to accurately quantify differential steepness and concavity values for the area of the San Gabriel Mountains in Southern California. Finally, the application of different smoothing options on the plots of slope-drainage area analysis of the tributaries of the San Gabriel Mountains suggests that a 600 meter window size is the optimum size with more reliable information and better noise elimination.
Katerina Dimitris Spyropoulou.
S.M.in Geosystems
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Dunaj, Lindsay L. „Comparing Newly Built Wetlands in the Atchafalaya Bay, Louisiana and Sacramento-San Joaquin Delta, California“. ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1515.

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This research investigated patterns in elevation change in newly built wetlands in the Atchafalaya delta, and newly restored wetlands in the Sacramento-San Joaquin River delta. RSETs were used to measure small changes in elevation, and soil cores were processed to examine mineral and organic contributions. Elevation change was highly variable, responding to influences from water level, river discharge, storms and vegetation. Mineral matter consistently added more to the marsh soil through volumetric and gravimetric contributions. Organic contributions were not significantly different across sites, suggesting the type of emergent vegetation at a site may not be the most important factor. Sites with the lowest elevations had the highest rates of positive elevation change. Higher elevation sites were more exposed and had negative rates of elevation change. The findings suggest ideal sites for marsh building are in areas that receive sediment input, are protected from high-energy events, and can support emergent vegetation.
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Salmon, Summer Anne. „A New Technique for Measuring Runup Variation Using Sub-Aerial Video Imagery“. The University of Waikato, 2008. http://hdl.handle.net/10289/2511.

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Video monitoring of beaches is becoming the preferred method for observing changes to nearshore morphology. Consequently this work investigates a new technique for predicting the probability of inundation that is based on measuring runup variation using video. Runup is defined as the water-level elevation maxima on the foreshore relative to the still water level and the waterline is defined as the position where the MWL intersects the beach face. Tairua, and Pauanui Beaches, on the north east coast of the North Island of New Zealand, were used as the field site in this study and represent two very different beaches with the same incoming wave and meteorological conditions. Tairua is most frequently in an intermediate beach state, whereas Pauanui is usually flatter in nature. In order to rectify runup observations, an estimate of the runup elevation was needed (Z). This was estimated by measuring the variation of the waterline over a tidal cycle from time-averaged video images during a storm event and provided beach morphology statistics (i.e. beach slope (α) and beach intercept (b)) used in the rectification process where Z=aX+b. The maximum swash excursions were digitized from time-stacks, and rectified to provide run-up timeseries with duration 20 minutes. Field calibrations revealed a videoed waterline that was seaward of the surveyed waterline. Quantification of this error gave a vertical offset of 0.33m at Tairua and 0.25m at Pauanui. At Tairua, incident wave energy was dominant in the swash zone, and the runup distributions followed a Rayleigh distribution. At Pauanui, the flatter beach, the runup distributions were approximately bimodal due to the dominance of infragravity energy in the swash signal. The slope of the beach was a major control on the runup elevation; runup at Pauanui was directly affected by the deepwater wave height and the tide, while at Tairua there was no correlation. Overall, the results of the study indicate realistic runup measurements, over a wide range of time scales and, importantly, during storm events. However, comparisons of videoed runup and empirical runup formulae revealed larger deviations as the beach steepness increased. Furthur tests need to be carried out to see if this is a limitation of this technique, used to measure runup. The runup statistics are consistently higher at Tairua and suggests that swash runs up higher on steeper beaches. However, because of the characteristics of flatter beaches (such as high water tables and low drainage efficiencies) the impact of extreme runup elevations on such beaches are more critical in regards to erosion and/ or inundation. The coastal environment is of great importance to Māori. Damage to the coast and coastal waahi tapu (places of spiritual importance) caused by erosion and inundation, adversely affects the spiritual and cultural well-being of Māori. For this reason, a chapter was dedicated to investigating the practices used by Māori to protect and preserve the coasts in accordance with tikanga Māori (Māori protocols). Mimicking nature was and still is a practice used by Māori to restore the beaches after erosive events, and includes replanting native dune plants and using natural materials on the beaches to stabilize the dunes. Tapu and rahui (the power and influence of the gods) were imposed on communities to prohibit and prevent people from free access to either food resources or to a particular place, in order to protect people and/ or resources. Interpretations of Māori oral histories provide insights into past local hazards and inform about the safety and viability of certain activities within an area. Environmental indicators were used to identify and forecast extreme weather conditions locally. Māori knowledge of past hazards, and the coastal environment as a whole, is a valuable resource and provides a unique source of expertise that can contribute to current coastal hazards management plans in New Zealand and provide insights about the areas that may again be impacted by natural hazards.
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Klinka, Karel, Bernhard E. Splechtna, Jaroslav Dobry und Christine Chourmouzis. „Climate - radial growth relationships in some major tree species of British Columbia“. Forest Sciences Department, University of British Columbia, 1998. http://hdl.handle.net/2429/671.

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This study examines the influence of climate on tree-ring properties of several major tree species: Pacific silver fir (Abies amabilis (Dougl. ex Loud.) Forbes), subalpine fir (Abies lasiocarpa (Hook.) Nutt.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and lodgepole pine (Pinus contorta var. latifolia Dougl. ex Loud.). Our three objectives were to determine how (1) tree-ring properties change along an elevation gradient, (2) short-term climatic influences are correlated with tree-ring properties, and (3) long-term climatic influence on tree-ring properties.
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Saderi, Seyedehmasoumeh. „Dynamiques de la formation du bois du Mélèze (Larix decidua Mill.) le long d’un gradient altitudinal de 1000 m dans les Alpes du sud Françaises“. Thesis, Paris, AgroParisTech, 2017. http://www.theses.fr/2017AGPT0015.

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La survie des plantes pérennes dépend de leur capacité à s'adapter à leur environnement. Les modèles de végétation prédisent que les changements climatiques vont avoir un effet profond sur la production et la distribution des forêts. La réponse des arbres aux changements climatiques dépend de la capacité du cambium à produire un bois performant. L'objectif est de comprendre quelles modifications des processus de formation du bois permettent aux arbres de croître dans des conditions contrastées. Nous avons suivi la formation du bois de 60 mélèzes, en 2013, dans quatre peuplements, le long d'un gradient altitudinal de 1000 m dans les Alpes du Sud. Des échantillons ont été prélevés chaque semaine. Les cellules en formation ont été classées et comptées en fonction de leur stade de différentiation (division, élargissement, épaississement et mature). De plus, l'occurrence de tissus cicatriciels a été notée. Le comptage cellulaire a ensuite servi à calculer les dates critiques de la formation du bois à l'aide de régressions logistiques, alors que la croissance du bois était décrite par l'ajustement de modèle de Gompertz. Les dates et taux obtenus ont été comparés au gradient altitudinal grâce à des tests bootstrap et des modèles linéaires mixtes. La contribution relative à la production annuelle totale du taux par rapport à la durée a été estimée à l'aide d'une analyse de sensibilité. L'activité cambiale (AC) a commencé vers mi-mai pour le site le plus bas du gradient et vers mi-juin pour le site le plus élevé, ce qui correspond à un retard de 3 jours par 100 m. Le début des autres périodes de la formation du bois (FB) suivaient la même tendance altitudinale, mais avec un décalage de quelques jours à un ou deux mois. Les fins de l'AC et de la FB suivaient une tendance parabolique avec les arbres du peuplement le plus bas finissant en premier, ceux du peuplement le plus haut en second, et ceux des peuplements intermédiaires en dernier. Les durées totales de l'AC et de la FB présentaient également des tendances paraboliques avec les durées les plus courtes à 2300 m, et les plus longues à 1700 m. Néanmoins, nous avons découvert que le raccourcissement de la saison de végétation lié à l'altitude était compensé par une augmentation des taux de production cellulaire aboutissant à des largeurs de cernes finales comparables pour les trois peuplements du haut. Le peuplement du bas, au contraire, présentait des cernes plus étroits, en raison de saisons de végétation plus courtes et de taux de production plus bas. L'analyse de sensibilité a montré que le nombre de cellule final était plus influencé par le taux de production que par sa durée. Nous avons constaté une augmentation du nombre de cellules cambiale avec l'altitude, qui contrebalançait l'allongement du cycle cellulaire, et maintenait un taux de production important. Enfin, nous n'avons pas observé de tissues cicatriciels mais un nombre important de canaux résinifères. Un examen détaillé des résidus des ajustements des Gompertz a conduit à penser que le microcarottage stimule légèrement l’AC, perturbant la xylogénèse et la structure finale des cernes de croissance. Les délais observés dans le démarrage de l'AC et de la FB peuvent être associés au gradient adiabatique de température et être ainsi convertis en un allongement de la saison de végétation de 5 jours par °C. D'un autre côté, nos résultats montrent que c'est plutôt la photopériode qui détermine la fin de l’AC, bien qu'une restriction hydrique soit capable de précipiter cette fin. Cependant, même si la phénologie est une composante importante du fonctionnement des forêts, nos résultats soulignent le rôle majeur du taux d’activité cambiale en ce qui concerne la croissance. L'investissement structural consistant à augmenter le nombre de cellules cambiales pour soutenir le taux de division quand l'altitude augmente, que la température baisse, et que le cycle cellulaire s'allonge, révèle un mécanisme d'adaptation puissant
The survival of perennial plants depends on their ability to remain adapted to their ever-changing environment. Vegetation model predictions indicate that climate change will have profound effects on forest production and distribution. Tree response to environmental factors amply relies on cambium ability to produce efficient wood. The main objective of this thesis is to understand which modifications of the wood formation (WF) processes allow trees to grow under contrasted conditions. The xylogenesis of 60 larch trees, in four stands along an elevation gradient of 1000 m in the French Southern Alps was monitored in the 2013. Wood samples were taken every week from tree stem.. Forming wood cells counted according to their differentiation stage (dividing, enlarging, wall thickening and mature). Moreover, the occurrence of wounding tissues were recorded. Meteorological data were obtained from nearby climate stations andrelative extractable water was computed using a water balance model. Thecritical dates of wood formation were computed based on logistic regression, while wood growth dynamics was described using Gompertz models. Dates and rates were then compared along the elevation gradient using bootstrap tests and mixed-effects models. The relative contribution to the total annual production of rates vs. durations was assessed using a sensitivity analysis of a basic physical model. Cambial activity (CA) started around mid-May at the lowest stand and around mid-June at the highest one, which correspond to a delay of 3 days per 100 m. The onsets of the other periods of wood formation followed exactly the same elevation trend, but were lagged in time of a few days up to one or two months. The cessation of CA and WF followed a parabolic trend with trees from the lowest stand finishing first, followed by those from the highest stand, while those from the intermediate elevations finished the last. CA and WF durations also exhibited parabolic trends, but with the shortest season occurring at 2300 m and the longest ones at 1700 m Nevertheless, we discovered that the elevation-related shortening of the growing season, was compensated by an increase in the cell production rate, leading to comparable tree-ring widths in the three upper stands. The lowest stand, on the contrary, exhibited narrow tree rings due to both low production rates and short durations. The sensitivity analysis showed that the final cell number was more related to the rate of production than to its duration. Moreover, our results showed that the number of cambial cell increased with elevation, which compensated the lengthening of the cell cycle, and thus maintained high production rates, even at high elevation. Lastly, we didn't observe any callus tissue in our anatomical sections, but we counted numerous traumatic resin canals. Moreover, a careful examination of Gompertz fitting residuals leaded us to think that microcoring monitoring slightly stimulated cambial activity, disturbing xylogenesis and final tree-ring structure. We believe, however, that the overall impact of cambial stimulation on wood formation phenology and dynamics remains limited. So the delay in the wood formation CA and WF onsets with increasing elevation can be associated with the adiabatic temperature decrease and thus translated into a lengthening of the growing season of about 5 days per °C. On the other hand, our results show that the cessation of cambial activity is more related to photoperiod, even with water shortage being able to hasten growing season termination. However, even if phenology is a key component of forest functioning, our results underlined the pivotal role of the rate of cambial activity in tree growth. Structural investment to sustain cell division rates while elevation increase, thanks to increased number of cambial cells, and despite temperature-related increased of cell cycle length, unveil a strong adaptation mechanism of trees to high elevations
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Klinka, Karel. „Trembling aspen site index in relation to environmental measures of site quality“. Forest Sciences Department, University of British Columbia, 2001. http://hdl.handle.net/2429/666.

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Trembling aspen (Populus tremuloides Michx.) is one of the most common tree species in the boreal and temperate forests of North America. It grows on many different sites and associates with a variety of tree species. In BC, aspen is frequent throughout all submontane and montane continental forested zones. Relationships between environmental factors and forest productivity have been the subjects of many studies. Most of these studies, using various topographic, soil, physical and chemical properties as independent variables, had limited success in accounting for the variation in SI over a large geographic area. The objectives of this study were (1) to quantify relationships between aspen SI and environmental factors at two spatial scales, and (2) to develop predictive SI models from easily measurable environmental factors.
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Jelínek, Roman. „Bytový dům ve Zlíně“. Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-225804.

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The aim of this thesis is to elaborate project documentation for new construction of low-energy residential building with 16 luxury apartments, apartment without barriers and with pharmacy of basic type. It is a four-storey detached building without basement, with flat roof, roof terraces and with balconies. Residential building is located in one of the most enjoyable parts of the city of Zlín – Jižní Svahy II in the vicinity of Central park with bicycle path and with beautiful view of the Zlín. The building will be located on land plot No. 2144/46, where is still situated unfinished building "Torso" from the late 80 years. The residential building is designed in brick system Heluz, ceiling construction is made up of prestressed hollow core slabs, perimeter walls are with external thermal insulation composite system and external doors and windows are made of plastic and aluminum with triple glazing. For heating and water heating will be utilized renewables energy, such as heat pump and solar collectors. Residential units with three residential rooms are designed with a forced ventilation by means of ventilation units with heat recovery. The building also uses modern shielding elements such as outdoor blinds and horizontal sun breakers. The part of the project are also disposition studies, seminar work and energy part.
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Ashith, Shyam R. Babu. „Design and Development of a Three-degree-of-freedom Parallel Manipulator to Track the Sun for Concentrated Solar Power Towers“. Thesis, 2017. http://etd.iisc.ernet.in/2005/3561.

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In concentrated solar power (CSP) stations, large arrays of mirrors which are capable of changing its orientation are used to reflect the incident solar energy to a stationary receiver kept at a distance. Such mirrors are often called as heliostats. The receiver contains a heat absorbing medium like molten salt. By absorbing the thermal energy reflected from thousands of heliostats, the temperature would reach around 6000C and the heat can be used in thermal power plants to generate steam and thus run a turbine to produce electricity. One of the biggest advantages of CSP over conventional energy harvesting from Sun is that it can generate electricity during night for long hours of time from the thermal energy stored during daytime. This eliminates the usage of batteries or any other energy storing methods. The conversion efficiency is also high in CSP due to the high temperature achieved. With prior knowledge of the station coordinates, viz., the latitude and longitude, the day of the year and time, the direction or the path of sun can be fully determined. Typically, the sun's motion is tracked by the azimuth-elevation (Az-El) or the target-aligned configuration heliostats. In both these approaches, the mirror needs to be moved about two axes independently using two actuators in series with the mirror effectively mounted at a single point at the centre. This arrangement causes the mirror to deform in presence of gusty winds in a solar field which results in loss of pointing accuracy. Typically a beam error of less than 2-3 mrad is desirable in a large solar field and this value also includes other sources of loss of pointing accuracy like gravity and wind loading. In order to prevent this, a rigid support frame is required for each of the heliostats. In this work, two three degree-of-freedom parallel manipulators, viz., the 3-UPU wrist and 3-RPS, have been proposed to track the sun in central receiver systems. The main reasons for choosing a parallel manipulator as heliostat are its desirable characteristics like large load carrying capacity, high accuracy in positioning the mirror and easy to obtain the inverse kinematics and convenient for real time control. The proposed parallel manipulators support the load of the mirror, structure and wind loading at three points resulting in less deflection and thus a much larger mirror can be moved with the required tracking accuracy and without increasing the weight of the support structure. The algorithm for sun tracking is developed, extensive simulation study with respect to actuations required, variation of joint angles, spillage loss and leg intersection has been carried out. Using FEA, it is shown that for same sized mirror, wind loading of 22 m/s and maximum deflection requirement (2 mrad), the weight of the support structure is between 15% and 60% less with the parallel manipulators when compared to azimuth-elevation or the target-aligned configurations. A comprehensive study on stroke minimization of prismatic joints is carried out. It is found that a stroke of 700 mm is required for a 2 m x 2 m heliostat at Bangalore when the farthest heliostat is at a distance of 300 m from the tower. Although, there is an extra motor required to track the sun, the 3-RPS manipulator is better than the conventional methods if the mirror area per actuator criteria is taken into consideration. Prototypes of the Az-El and 3-RPS heliostats were made with a mirror size of 1 m x 1 m. A PID controller implemented using MATLAB-Simulink and a low cost, custom made motor driver circuit is used to control the motion of the 3-RPS heliostat. The algorithm developed is tested on the prototype by tracking a point marked on the wall of the lab space and is found to have a tracking error of only 7.1 mrad. Finally, the actual sun tracking is carried out on the roof of a building reflecting the sun-light to a wall situated 6.72 m above and a distance of 15.87 m from the heliostats. The images are captured at various instances of time from 11:30 a.m. to 3:30 p.m. on October 15th and November 10th, 2016, tracking errors are quantified and it is demonstrated that the proposed 3-RPS parallel manipulator can indeed work as a heliostat in concentrated solar power plants.
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Bücher zum Thema "Sun elevation"

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Sharron, Brundige, Hrsg. Bicycle rides.: 83 rides with detailed maps & elevation contours. 4. Aufl. San Pedro, Calif: B-D Enterprises, 2000.

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Taylor, Lisa A. Digital elevation model of Port San Luis, California: Procedures, data sources and analysis. Boulder, Colo: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Environmental Satellite, Data, and Information Service, National Geophysical Data Center, 2008.

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S, ar) 1. Goodman, und Field Museum of Natural, Hrsg. A floral and faunal inventory of the R©Øeserve sp©Øeciale d'Anjanaharibe-Sud, Madagascar: With reference to elevational variation. [Chicago, Ill.]: Field Museum of Natural History, 1998.

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Goodman, Steven M. A Floral and Faunal Inventory of the Reserve Speciale D'Anjanaharibe-Sud, Madagascar: With Reference to Elevational Variation (Fieldiana. New Series. Zoology, No 90). Field Museum of Natural, 1998.

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A Beautiful and accurate elevation of the Temple of Solomon taken from the celebrated model erected by counsellors Schott at Hamburgh: Ornamented with the most interesting passages in the lives of King David and Solomon his son .. [Toronto?: s.n., 1985.

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Buchteile zum Thema "Sun elevation"

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Tape, Walter. „The role of sun elevation“. In Atmospheric Halos, 58–68. Washington, D. C.: American Geophysical Union, 1994. http://dx.doi.org/10.1029/ar064p0058.

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Guo, Minghuan, Zhifeng Wang und Zhenwu Lu. „The Optical Designing Method and the Concentrating Performance Analysis for a Toroidal Heliostat with Spinning-Elevation Sun Tracking“. In Proceedings of ISES World Congress 2007 (Vol. I – Vol. V), 1878–82. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-75997-3_383.

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Tape, Walter. „Halo simulations at selected sun elevations“. In Atmospheric Halos, 108–21. Washington, D. C.: American Geophysical Union, 1994. http://dx.doi.org/10.1029/ar064p0108.

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Ghandehari, Mehran, Barbara P. Buttenfield und Carson J. Q. Farmer. „Cross-Scale Analysis of Sub-pixel Variations in Digital Elevation Models“. In Advances in Cartography and GIScience, 359–73. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-57336-6_25.

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Keilig, Klaus-Peter, Andreas Dietrich und Michael Krautblatter. „Comparison of Multi-temporal Elevation Models of a Debris-Flow Channel“. In IAEG/AEG Annual Meeting Proceedings, San Francisco, California, 2018 - Volume 1, 275–82. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-93124-1_33.

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Malik, Sumaira M., und Nauman ARIF Chaudary. „Pheochromocytoma presenting as Takotsubo cardiomyopathy and ST-segment elevation myocardial infarction“. In The Endocrine Society's 95th Annual Meeting and Expo, June 15–18, 2013 - San Francisco, MON—62—MON—62. 2055 L Street NW, Suite 600, Washington, DC 20036: The Endocrine Society, 2013. http://dx.doi.org/10.1210/endo-meetings.2013.ahpaa.11.mon-62.

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Ouma, Paul, Peter M. Macharia, Emelda Okiro und Victor Alegana. „Methods of Measuring Spatial Accessibility to Health Care in Uganda“. In Practicing Health Geography, 77–90. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63471-1_6.

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AbstractEnsuring everyone has access to health care regardless of demographic, geographic and social economic status is a key component of universal health coverage. In sub-Saharan Africa, where populations are often sparsely distributed and services scarcely available, reducing distances or travel time to facilities is key in ensuring access to health care. This chapter traces the key concepts in measuring spatial accessibility by reviewing six methods—Provider-to-population ratio, Euclidean distance, gravity models, kernel density, network analysis and cost distance analysis—that can be used to model spatial accessibility. The advantages and disadvantages of using each of these models are also laid out, with the aim of choosing a model that can be used to capture spatial access. Using an example from Uganda, a cost distance analysis is used to model travel time to the nearest primary health care facility. The model adjusts for differences in land use, weather patterns and elevation while also excluding barriers such as water bodies and protected areas in the analysis. Results show that the proportion of population within 1-h travel times for the 13 regions in the country varies from 64.6% to 96.7% in the dry period and from 61.1% to 96.3% in the wet period. The model proposed can thus be used to highlight disparities in spatial accessibility, but as we demonstrate, care needs to be taken in accurate assembly of data and interpreting results in the context of the limitations.
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„elevator sub“. In Dictionary Geotechnical Engineering/Wörterbuch GeoTechnik, 465. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-41714-6_50892.

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„Biology and Management of Dogfish Sharks“. In Biology and Management of Dogfish Sharks, herausgegeben von John W. Mandelman und Marianne A. Farrington. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781934874073.ch20.

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Abstract.—To provide a synthesis of the physiological responses to otter-trawl capture in spiny dogfish <em>Squalus acanthias</em>, blood values from trawled individuals were evaluated against values from minimally stressed dogfish caught rapidly by hook and line (control). Values and analyses from published studies are considered along with those from the most expansive set of blood samples taken from dogfish captured by both methods to date. Significant impacts of trawling on dogfish blood physiology were reflected in all parameters excluding log plasma protein. Parameters for whole-blood acid–base status (pH, significant decrease; pO<sub>2</sub>, 45% decrease; pCO<sub>2</sub>, 82% increase), and the metabolite lactate anion (125% increase) were most perturbed relative to differences induced by the capture methods in other parameters. The concentrations of sera monovalent electrolytes (Na<sup>+</sup>, K<sup>+</sup>, Cl<sup>-</sup>) and glucose were significantly elevated by trawling, but not to the magnitude seen in other studies related to capture stress in fish. Significant elevations in hematocrit and reductions in blood urea nitrogen (BUN) concentrations were also observed subsequent to trawling. Overall, this capture method incited marked changes in blood physiology relative to values in minimally stressed dogfish. However, previous studies demonstrating high rates of posttrawl dogfish survival indicate that such changes are resolvable in this species prior to lethal consequences.
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Gencer, Baris, und Marco Roffi. „Special conditions: acute coronary syndromes“. In ESC CardioMed, 929–35. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0218.

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Diabetes is a major risk factor for cardiovascular disease and is associated with an increased risk of mortality in the setting of acute coronary syndromes. Like patients without diabetes, ST elevation and non-ST elevation myocardial infarction patients mandate immediate and within 24 h coronary angiography, respectively. Even in the absence of troponin elevation, all patients with diabetes with suspected acute coronary syndromes should undergo coronary angiography within 72 h due to their increased risk (which is not the case for individuals without diabetes). Antiplatelet treatment should be handled as in patients without diabetes, and the more potent P2Y12 inhibitors prasugrel and ticagrelor should be preferred over clopidogrel. Overall, trials investigating the impact of intensive glucose-lowering therapies in the acute phase of acute coronary syndromes did not show a positive impact on clinical outcomes. In the long term, efforts in secondary prevention to reach recommended global preventive targets are especially important in this patient population to improve survival and reduce the recurrence of ischaemic events.
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Konferenzberichte zum Thema "Sun elevation"

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Aliman, Omar, und Ismail Daut. „Rotation-Elevation of Sun Tracking Mode to Gain High Concentration Solar Energy“. In 2007 International Conference on Power Engineering, Energy and Electrical Drives. IEEE, 2007. http://dx.doi.org/10.1109/powereng.2007.4380115.

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Chong, Kok-Keong, und Chee-Woon Wong. „Open-loop azimuth-elevation sun-tracking system using on-axis general sun-tracking formula for achieving tracking accuracy of below 1 mrad“. In 2010 35th IEEE Photovoltaic Specialists Conference (PVSC). IEEE, 2010. http://dx.doi.org/10.1109/pvsc.2010.5614088.

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Cristea, Octavian, Paul Dolea, Paul-Vladut Dascal und Tudor Palade. „Influence of sun elevation, azimuth and X-ray bursts on long distance VLF radio propagation“. In 2014 10th International Conference on Communications (COMM). IEEE, 2014. http://dx.doi.org/10.1109/iccomm.2014.6866694.

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Tseng, Kuo-Hsiung, Chuan-Yi Wang und Guan-Hung Lin. „Effect of the Sun Elevation for Fixed PV System and Single-Axis-Tracking PV System“. In 2019 IEEE 6th International Conference on Industrial Engineering and Applications (ICIEA). IEEE, 2019. http://dx.doi.org/10.1109/iea.2019.8714782.

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Kozlov, Valerii S., Mikhail V. Panchenko und Elena P. Yausheva. „Seasonal variability of diurnal behavior of concentrations of submicron aerosol and absorbing substance in coordinates of sun elevation“. In SPIE Proceedings, herausgegeben von Gennadii G. Matvienko und Victor A. Banakh. SPIE, 2006. http://dx.doi.org/10.1117/12.723187.

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Hwang, Eui-seung, Sun-Kon Kim, Do-Young Kim und Ki-Jung Park. „Vibration Serviceability of Long Span Cable Bridges using Long-term Monitoring Data“. In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.1539.

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<p>Along with building slender and longer span structures, vibration serviceability becomes more important considerations in bridge design and maintenance. In this study, vibration serviceability and deflection limit for long span cable bridges are investigated using long-term monitoring data such as accelerations and displacements of bridges. Exampled bridges are Yi Sun-Sin Grand Bridge (suspension bridge, main span length=1,545m) and 2<sup>nd</sup> Jindo Grand Bridge (cable stayed bridge, main span length=344m). Long-term data are analyzed and compared with various design codes, guidelines, and other research results. Probability of exceedance are calculated for each criterion. Regarding on deflection limits, Korean Bridge Design Code (Limit State Design) specifies L/400 and L/350 for cable stayed and suspension bridges, respectively. Saadeghvaziri suggested deflection limit based on natural frequency, acceleration limit of 0.5 m/s² and vehicle speed. Various human comfort criteria on vibration are also applied including ISO standards. The results of this study are expected to be useful reference for the design, the proper planning and deflection review of the long span cable bridges around the world. Further researches are required to find the optimum deflection or vibration criteria for long span bridge and their effects on bridge clearance and elevation.</p>
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Al-Ansary, Hany, Shaker Alaqel, Eldwin Djajadiwinata und Abdullah Mohammed. „Optical Analysis of a New Point Focus Fresnel Concentrator“. In ASME 2015 9th International Conference on Energy Sustainability collocated with the ASME 2015 Power Conference, the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2015 Nuclear Forum. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/es2015-49340.

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This study describes preliminary optical analysis performed regarding a new collector called the Point Focus Fresnel Concentrator (PFFC). This collector combines the concepts of the linear Fresnel collector and central receiver systems to form a new concept of a focal point Fresnel concentrator with a dual-axis sun tracking system. It concentrates direct solar radiation using a number of flat mirrors positioned over a rotating frame. The frame tracks the sun in the azimuth direction, while each row of mirrors tracks the sun in the elevation direction, thereby allowing sunlight to be concentrated on the same point above the collector throughout the day. PFFC is considered suitable for a number of applications, such as power generation by concentrating photovoltaics (CPV) and Stirling engines, and process heat applications. In this study, the first attempt to characterize the optical performance of the collector is made. A prototype of the collector has already been built on the campus of King Saud University. It has a total footprint of 9 m2, and includes 900 mirrors, each of which is 7 cm × 7 cm. The receiver has a diameter of 10 cm. Optical performance is studied by ray tracing methods to obtain flux maps and intercept factors of the receiver. Results show that the average concentration ratio is in the order of 220 to 300 suns when mirrors with a 6-mrad optical error are used. For the same mirrors, the highest attainable average intercept factor (0.674) occurs in the winter due to the low particle loading in the atmosphere. When the optical error is reduced to 2 mrad, the average concentration ratio increases to 290 to 400 suns, and the average intercept factor increases to 0.892. In any case, if the current design of PFFC is to be used in conjunction with CPV, a secondary concentrator would be needed to achieve required concentration ratios in the order of 500 suns.
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Steffen, Bridgette J., Charles E. Andraka und Richard B. Diver. „Development and Characterization of a Color 2F Alignment Method for the Advanced Dish Development System“. In ASME 2003 International Solar Energy Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/isec2003-44239.

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Dish/Stirling systems rely on accurate mirrors and alignment. Inaccuracies in alignment can lead to flux “hotspots” that can reduce performance and even damage the solar receiver. To improve the alignment process a procedure that can be used to align solar dish concentrator facets was developed on the second-generation (Mod 2) Advanced Dish Development System (ADDS) at Sandia National Laboratories in Albuquerque, NM. The previously used facet alignment method was based on the distant light source technique and required the dish to be pointed near the horizon while an observer located approximately 100 meters away views the image of a target and calls in adjustments to an aligner. At high sun elevation angles structural deflections inherent in any dish concentrator result in facet misalignments. To address these issues while allowing improved access to facet adjustments, an alignment technique that permits alignment at any elevation angle was developed and evaluated. This technique utilized a video camera and color target affixed on a lightweight tower at a distance near twice the dish focal length (2f) from the vertex of the dish, hence the name “color 2f”. The camera and target are centered on the optical axis of the concentrator. During the initial evaluation of the color 2f facet alignment procedure on the ADDS Mod 2 concentrator, no facet adjustments were made. Instead concentrator facet deflections were measured by taking and evaluating images of the dish reflecting the target while the dish was pointed at the horizon, 45 degrees elevation, and vertical. These images were compared to each other, to determine gravity induced pointing errors as the dish changes in elevation. Future implementations of the color 2f system could be used to align the system rather than simply diagnose it. The proposed approach has the potential to accurately align concentrators without large open land spaces, and to account for elevation-induced structural deflections. In this paper, the color 2f alignment technique is described along with the results from the gravity induced structural deflection study. Issues and recommendations for improvement of the 2f alignment system are also presented.
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Glenn, Kyle. „Solar Furnace Heliostat Closed-Loop Control System“. In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90444.

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A 4.2 kW solar furnace heliostat was interfaced with a closed-loop control system to manipulate the azimuth and elevation rotational degrees of freedom to continuously align a solar concentrator with the sun. A QP50-6SD2 quadrant photodiode laser beam positioning device, developed by Pacific Silicon and Sensor, was modified to sense the orientation of the sun. The quadrant photodiode was mounted inside a dark box with a pinhole aperture and mounted so that when the heliostat reflects light along the desired axis, the quadrant photodiode relays balanced error signals. These error signals were interpreted with a Basic Stamp 2p40 microcontroller developed by Parallax Inc. LM741 operational amplifiers and ADC0831 analog to digital converters were used for signal conditioning. The 2p40 microcontroller interprets and checks the error signals every 500ms and uses a ULN2803 Darlington Transistor array to activate the heliostat drive motor’s solid-state relays to maintain solar alignment. The closed-loop heliostat control system can track with 1.6 degrees of accuracy. This is closer than the original prediction of 3 degrees. The control system requires user-inputs for initial alignment. Alignment can initiate with the heliostat out of alignment by at least 6 degrees. The versatility of the 2p40 allows subroutines to be programmed in that can handle hysteresis in the slewing of the heliostat, continue tracking as the heliostat begins to wobble from wind gusts, or continue tracking during intermittent shadowing from clouds.
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Gwesha, Ammar Omar, Yasir Mohammed Alfulayyih und Peiwen Li. „Optimization of Fixed PV Panel “Tilt” Angles for Maximal Energy Harvest Considering Year-Around Sky Coverage Conditions“. In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-10391.

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Abstract In order to maximize the electrical energy harvested by photovoltaic panels in a setup with fixed angles, it is important to get the angle optimized. In the present work, sunlight availability or sky coverage conditions of year-long period based on ten years’ data are counted in the modeling to optimize the PV panel tilt angles targeting for the maximal energy in a year. The analysis uses precise sunray calculation models. The energy harvested in every 6 minutes by a PV panel is summated for the daily time period from sunrise to sunset when the sun elevation angles are above 5 degree, with the sky-coverage factor multiplied. The results show that the annual solar energy received by a PV solar panel tilted with a fixed angle equal to the local latitude (at Tucson AZ, USA) could reach 2297 kWh/m2 under 10-year averaged sky coverage conditions. However, the gain in the yearly solar energy harvest is expected to be about 4.28%, 7.06%, and 8.42% higher if a PV panel is inclined optimally according to two-season, four-season, and monthly adjustments, respectively, compared to the optimized life-long fixed angle.
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Berichte der Organisationen zum Thema "Sun elevation"

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Riley, Daniel, und Clifford Hansen. Sun-relative pointing for dual-axis solar trackers employing azimuth and elevation rotations. Office of Scientific and Technical Information (OSTI), April 2014. http://dx.doi.org/10.2172/1177037.

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Kaelberer, Monte S. Ocean Sun Glint in the 3 to 5 Micron Region and Its Radiance Variation with Off Glint Sun Angle and Sensor Elevation. Fort Belvoir, VA: Defense Technical Information Center, März 1990. http://dx.doi.org/10.21236/ada248740.

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Wadman, Heidi, und Jesse McNinch. Elevation of underlying basement rock, Ogdensburg Harbor, NY. Engineer Research and Development Center (U.S.), Juni 2021. http://dx.doi.org/10.21079/11681/40843.

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Over six linear miles of shallow acoustic reflection geophysical data were collected in an 800 ft by 300 ft survey region at Ogdensburg Harbor, Ogdensburg, NY. To better accommodate modern commercial vessels and expand the harbor’s capacity, the current navigable depth of -19 ft Low Water Depth (LWD) needs to be increased to -28 ft LWD, and an accurate map of the nature of the riverbed material (e.g., unconsolidated sediment, partially indurated glacial till, or bedrock) is required to effectively plan for removal. A total of 28 boreholes were previously collected to map the stratigraphy, and the effort revealed significant spatial variability in unit thickness and elevation between adjacent boreholes. To accurately map this variable stratigraphy, chirp sub-bottom profiles were collected throughout the region, with an average line spacing of 13 ft. These sub-bottom data, validated and augmented by the borehole data, resulted in high-resolution spatial maps of stratigraphic elevation and thickness for the study area. The data will allow for more accurate assessment of the type and extent of different dredging efforts required to achieve a future uniform depth of -28 ft LWD for the navigable region.
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Lewis, C. E. The effects on photosynthetic CO{sub 2} assimilation to long-term elevation of atmospheric CO{sub 2} concentration: An assessment of the response of Trifolium Repens L. cv. Blanca grown at F.A.C.E. Office of Scientific and Technical Information (OSTI), November 1994. http://dx.doi.org/10.2172/10116180.

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Grain elevator owner's son dies after being engulfed in a corn bin. U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, April 1993. http://dx.doi.org/10.26616/nioshsface92mn025.

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