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The Moon, Earth’s only natural satellite, is a potential new platform for Earth observation. Moreover, with the wide applicability of the angular information from remote sensing data, it ha...

An Islamic prayer time has been extensively investigated by astronomers. However, since there are some issues regarding the different views in the fixation of the altitude of Sun, the twilight angle and the latest issues of an extra eight minutes that need to be added for Subh prayer time, therefore it was being re-calculate again. The purpose of this study is to re-identify Subh and Isha solar angle at Besut, Kuala Terengganu by using SQM-LU-DL and to compare official prayer times with the observations by providing time and angle differences to evaluate the correct time frame of Subh and Isha. This study is focused on the sky brightness that was being measured by using Sky Quality Meter-Lens-USB-Data Logger (SQM-LU-DL) to measure the twilight. The data for 2018 is from April until October. For 2019, there are only two months which are February and March with one minute interval in the range of SQM-LU-DL. The observation of the data is based on the pattern of the graph which is the growth curve by plotting the magnitude of the Sun against time. This data can be related to the altitude of the Sun which is the condition to determine the beginning of Subh and Isha prayers time. As the result, the average of theoretical and quantitative measurements of Isha is 17.59° and 17.80°, while for Subh is around 20.26° and 18.69°.

Rapidly changing light conditions can reduce carbon gain and productivity in field crops because photosynthetic responses to light fluctuations are not instantaneous. Plant responses to fluctuating light occur across levels of organizational complexity from entire canopies to the biochemistry of a single reaction and across orders of magnitude of time. Although light availability and variation at the top of the canopy are largely dependent on the solar angle and degree of cloudiness, lower crop canopies rely more heavily on light in the form of sunflecks, the quantity of which depends mostly on canopy structure but also may be affected by wind. The ability of leaf photosynthesis to respond rapidly to these variations in light intensity is restricted by the relatively slow opening/closing of stomata, activation/deactivation of C3 cycle enzymes, and up-regulation/down-regulation of photoprotective processes. The metabolic complexity of C4 photosynthesis creates the apparently contradictory possibilities that C4 photosynthesis may be both more and less resilient than C3 to dynamic light regimes, depending on the frequency at which these light fluctuations occur. We review the current understanding of the underlying mechanisms of these limitations to photosynthesis in fluctuating light that have shown promise in improving the response times of photosynthesis-related processes to changes in light intensity.

The needing of using clean energy increases every year because of the negative impact of emissions from electricity power plant and to reduce the costs of generating power by using natural energies like solar, wind, and other sources. The availability of using solar energy as source of producing electricity in Al-Hilla city by using Concentrating Solar Power (CSP) was investigated in this research. The major parameters in this study were the city position, and the annually amount of solar received, also, number of charts related to solar parameters for the management of CSP were derived and showed in this research. The using of CSP as electricity power can be important solution to force the problem of high cost of electricity power fuel needed and the lack of power produced because of increasing of power consumed specially in summer season.

Due to the rapid development of field operation, camping, exploration, or any other situation, most people require a short-term electric power supply. Therefore, solar power generation gets approved gradually. The angle between the panel and the solar angle of incidence play a decisive role in generating the efficiency of the solar panel. When the angle of incidence reaches 90 degree, the generating efficiency of the panel can also reach as high as 90%, whereas when the angle of incidence reaches 70 degree, the generating efficiency only gets 40% with quick decrease. In this present study, we introduced a mechanical structure, easy to assemble, dismantle and deliver, which is used for the relationship between the Earth and Sun movement. The hardware bracket and control software of the solar panel automatic tracking system consisted of HX4040W-8 aluminum profile, 200 W SUN-L single crystal solar panel and Singfo 1500W solar power generation system, large torque 86 stepping motor with 12.8 n.m static torque, driver dm860, STC12C5A60S2 single-chip and 1602A LCD. The results of electric power graph showed that the value measured by an automatic tracking system between 10:00 and 14:00 is significantly higher than the value of the fixed device.

The Geostationary Operational Environmental Satellite (GOES)-16 observatory was launched on 19 November 2016. During daily on-orbit operations, shadowing of the inboard magnetometer sensor unit occurs due to spacecraft geometry and solar angle. Throughout the shadowing periods of the inboard magnetometer, anomalous excursions of 20 nT are observed. In addition to the excursions during shadow events, the measurement difference between the inboard and outboard magnetometer varies over the day, indicating erroneous measurements by one or both magnetometers. Another immediate on-orbit observation was that based on the deployment rotations, the zero offsets of the X and Y axes were found to be significantly different, ∼30 nT, from ground calibration data. Because of these observables, an extensive root cause investigation was undertaken to correct the magnetometer system for the next spacecraft in the GOES-R series. This paper documents the efforts of that activity and the lessons learned as a result of the investigation.

This paper presents the design and implementation of a photovoltaic emulator, based on an accurate mathematical model of a photovoltaic panel, instead of the look-up table method. The latter requires more memory for increasing accuracy and considering all the desired environmental situations. Furthermore, the proposed approach takes into account the incidence solar angle, as an input parameter, to offer the possibility of evaluating daily losses for different values of tilt angle. The validation of the proposed emulator is carried out by comparing in real-time, both the studied panel output and the emulator output, under variable load, temperature, and irradiation levels. The emulator is able to operate online with connected solar radiation and temperature sensors or offline with recorded measurement vectors. The practical tests were performed on a prototype designed using a MATLAB C MEX S-function, dSPACE board 1104, and a controlled DC/DC converter. The results showed that the emulator was able to behave accurately as the studied photovoltaic panel.

The Sierra Nevada of Santa Marta (12°N) hosts a unique glaciated environment (6.5 km2) only 40 km distant from the Caribbean Sea. However, the remoteness of the glaciers and restricted access to the region has so far prevented onsite field work research from being undertaken. We worked with several very high resolution airborne and satellite images to delimit the extension of the glaciers during the maximum extension of the Little Ice Age (ca. 1850), when glaciers covered 81.6 km2, and the ice cover in four subsequent phases (1954, 1995, 2010 and 2016). Polar plots and Random Forest models enabled characterization of the spatial distribution of ice cover in the region, and how the impact of topographic and geographical variables changed over time. Results show that elevation was the most important variable in explaining the existence of glaciers during the LIA. Since then, the ice cover has gradually been receding to areas shielded from solar radiation, even though the solar angle at this latitude is very high. Thus, results clearly confirm that topography is increasing its importance to explain the glacier distribution over the study area, and the particular characteristics of where each ice body is found will gain importance. Nonetheless, the probability of ice being present as predicted by Random Forests in 2017 suggests that most of the ice cover located outside the most elevated areas of the Sierra is very likely to disappear in coming years.

The daily and seasonal cycles of spectral and intensity content in the sunlight that reaches the earth's surface constitutes a natural pacemaker for activity in the terrestrial biosphere. In humans and most mammals, the evolutionary consequence of this rhythmicity is the existence of a circadian rhythm, which regulates various vital activities such as the production of hormones, mating and feeding times, and sleep according to the solar angle and the characteristics of the daylight. Thus there is a spectral-temporal relationship underpinning the rhythmicity that got built into us over the ~1,000,000 years of evolution but now has to learn to cope with the abrupt changes brought in by electric lighting ~100 years ago, To improve human quality of life and wellness, it is desired to incorporate the principal characteristics of daylight' rhythmicity in lighting. Here we describe a smart LED lighting system capable of reproducing daylight's changes in relative spectral power and circadian content with time-of- day. It achieves high-fidelity reproduction of daylight's spectral and circadian content as a function of time in a compact, relatively inexpensive and novel system that could readily be adapted for production and may offer an additional yet unstudied solutions in areas were lighting as therapy are being developed.

The main objective of this thesis is to design and test a solar concentrating collector with heat storage for domestic applications, mainly solar cooking. The system must be cheap, robust, easy to use and maintain, and non-hazardous. The system must be able to store energy over 200◦C to enable cooking, baking and frying. The heat collection is performed with a parabolic trough focusing the energy on a focal line where the absorber stands, the whole system is driven with a solar tracker.The first task is to find relevant materials for heat storage. After investigation, latent heat materials show a better potential for this application, especially for their ability to store a lot of energy at constant temperature. The influence of solar tracking inaccuracy is investigated as well, and shows that by chosing a large absorber, it is possible to both reduce the influence of these inaccuracies and of the solar angle.The concept of self-circulation has numerous advantages, such as the absence of a pumping system and the self-regulation of the temperature. This concept is then tested with a first prototype to ensure that it is suitable for our objectives. The test shows a great ability for thermal oil to transfer energy from the collector to a heat storage placed above using the self-circulation principle. The next objective is then to optimize the heat transfer into the absorber. After comparing with electrical heating the performance of two different storages coupled with the same self-circulating loop, it appears that a storage with a larger volume of oil is more efficient than an aluminum-based storage. Coupled with latent heat materials, the oil-based storage is then the basis for the following tests.Experiments are conducted outdoors to test the charging of the system with the sun. Absorbers with and without insulation are tested, and as expected the insulation (air layer) around the absorber is necessary to reach quickly high temperatures. The system proves to be good enough to charge a storage in one sunny day starting from ambient temperature. The energy stored is large enough to provide cooking energy for two people. After charging, heat extraction experiments are conducted. The system shows great abilities for frying but boiling water takes time. After testing with a flat plate, it appears that the low quality of the contact between the top plate and the cooking pan contributes to the long cooking time. By improving the flatness of the top of the heat storage, boiling water can be performed in a reasonable time, competitive compared to traditional cookings devices or commercialized direct solar cookers. A final test was started with an evacuated tube around the absorber, and simulations on the upscaling of the storage are made to conclude on the potential of this concept. The measurements have successfully been compared with a dynamic system model. The computational model was used for upscaling analysis.

In this paper, we propose a novel algorithm for accurately estimating the degree of radiometric non-uniformity in remote sensing images. The algorithm was tested on high-quality images and heavily striping images, and quantitative analyses were conducted to evaluate the performance for each band by measuring the radiometric non-uniformity of the images. The results demonstrated that the proposed algorithm exhibits high accuracy and stability compared with traditional algorithms. The radiometric performance of TianGong-1 short-wave infrared images was calculated using this new method, and it was highly correlated with the solar angle, pitch angle and refrigerator thermal according to the Apriori algorithm. Based on these results, we have proposed a strategy for restricting increases in striping.

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2016, Thesis (M.Sc.) -- İstanbul Technical University, Instıtute of Science and Technology, 2016, Enerji, tüm çeşitleriyle dünyaya yön veren, insanlık tarihinin en başından itibaren varolmuş ve olmaya devam edecek önemli bir unsurdur. Dünyanın değişimi, her ne kadar nüfus ve teknolojiyle orantılı olsa da enerji; teknolojiyi ve dünyayı döndüren çarklardan en önemlisidir. Nüfus artışı, sanayileşme ve teknolojideki gelişmeler ile akabinde gelen küreselleşme sonucunda enerjiye olan ihtiyaç gün geçtikçe artmaktadır. Dünyada enerji başlangıçta fosil yakıtlara dayansa da, zamanla bu tür yenilenmeyen yakıtların bir başka deyişle başlıca kömür, petrol ve doğalgaz rezervlerinin tükenmesiyle ve fosil yakıtların ekosisteme verdikleri zararın artması sonucunda küresel ısınma probleminin ortaya çıkmasıyla farklı enerji kaynaklarına yönelinmiştir. Her ne kadar, fosil enerji kaynakları Dünya enerji talebinde önemini gelecekte de sürdürecek olsa da, bu tür kaynaklara alternatif olan enerji kaynakları çok eski olmamakla birlikte geçmişten günümüze kadar varlığını devam ettirmiş ve teknolojik gelişmeler, bilimsel çalışmalar ve ekonomik yatırımlar sayesinde gün geçtikçe gelişen, ekosisteme duyarlı ve önü açık enerji sahaları var olacaktır. Bahsi geçen, enerji kaynakları başlıca; rüzgar, güneş, jeotermal, hidrolik enerji ve biyoenerji gibi enerji kaynakları olan bu sürdürülebilir enerji kaynakları gelişmekte olup, ilerleyen teknoloji ile gelecekte fosil yakıtlardan ziyade başvurulan yegane yakıt türü olacaktır. Sürdürülebilir enerji kaynakları içerisinde önemli yere sahip olan güneş enerjisi, teknolojinin de gelişmesine paralel olarak dünya genelinde rağbet görmektedir. Dünya’nın her yerinde konu ile ilgili çeşitli konferanslar, iyileştirme toplantıları yapılmakta ve her yıl devlet kanalları, kuruluşlar, dernekler ve üniversiteler yıllık raporlar sunmaktadır. Bu bağlamda, tezin amaçlarından biri dünya ve Türkiye genelinde güneş enerjisi teknolojisinin yerini tayin etmektir. Öte yandan, geniş kapsamlı bir uygulama alanına sahip bu enerji sahasında, bölgesel ve kısmi projeler yürütülmektedir. Yapılan projelerin ilk kurulum maliyetlerinin yüksek olması gibi sebeplerden ötürü, proje çalışması başlamadan önce çeşitli incelemeler ve analizler yapılmaktadır. Bahsi geçen bu ön değerlendirmenin kapsamı; bölge yapısından, maliyet analizine kadar uzanan geniş bir yelpazeye sahiptir. Öte yandan incelenmesi gereken birincil unsur uygulama bölgesine ait güneş ışınım süreleri ve ışınım özellikleridir. Işınım ölçüm cihazlarının alım ve kalibrasyon maliyetleri yüksek olduğundan gelişmekte olan ülkeler başta olmak üzere dünya genelinde ışınım değerleri tayinine ait modeller ortaya sunulmuş ve sunulmaya devam etmektedir. Modeller, genellikler seçili kısıtlı bölgeleri kapsasa da geniş alanlara yönelik hesaplamalar çıkartılma yönünde de çalışmalar vardır. Bu tezin esas amaçlarından biri, literatürde var olan ve Türkiye özelinde geliştirilmiş yatay düzelme gelen ışınım modellerini ortaya koymak ve Türkiye genelinde belirlenen bölgelerdeki seçilen istasyonlar özelinde literatürden seçilen bu modelleri değerlendirmektir. Modeller için yapılan istatistik analiz sonucunda tez dahilinde en uygun modelleri belirlemek amaçlanmıştır. Öte yandan, Enerji ve Tabii Kaynaklar Bakanlığından alınan veriler dahilinde yeni modeller literatüre kazandırılmak bu tezin en önemli amaçlarından biridir. Tezin ilk bölümünde, güneş enerjisinin Türkiye ve Dünya genelinde gelişimine ve mevcut durumuna yer verilmiştir. Dünya ve Türkiye için yayınlanan kurulu güç ve yapılan/yapılacak olan yatırımlara yönelik devletler, kurum ve kuruluşlar hazırlanan tarafından yıllık raporlar ve mevzuatlar incelenmiştir. Öte yandan, enerji yatırımlarının hukuki ve hükümet açısı incelenmiş, mevcut devlet destekli projeler rakamlarla ifade edilmiştir. Yapılan bu analiz devamında, literatürde yayınlanan güneş enerjisi ile ilgili çalışmalar değerlendirilip tezin literatür kısmında detaylandırılmıştır. Bahsi geçen bu çalışmalar, güneş ışınım değerlerinin tayinine ait literatüre kazandırılan modellerin incelenmesini ve belirli bölgeler için analizlerini kapsamaktadır. Öte yandan, literatüre yeni güneş ışınım modelleri sunan çalışmalar da tezin literatür incelemesi kısmına dahil edilmiştir. Literatür kısmında bahsedilen bu analiz, tez konusu kapsamında olup, bu bağlamda literatürde var olan model çalışmaları ve/veya literatüre sunulan modellerin tarama çalışmaları gözönüne alınmıştır. Tez kapsamında olmayan, farklı meteorolojik parametrelere, bölge coğrafyası ve iklimine bağlı modellerden bahsedilmemiştir. Bunun yanısıra, tezin literatür kısmında incelenen tez konusu kapsamındaki modeller yine tez konusu dahilindeki bölge olan Türkiye için türetilen ve literatürde varolan modellerdir. İlk kısmın akabinde, tezin ikinci bölümünde güneş enerjisi fiziğine değinilmiştir. Güneş enerjisi uygulamaları için yapılacak olan hesaplamalarda, seçilecek bölge için yıllık güneş ışınım değerleri önemli bir yere sahip olmakla birlikte bunun için en önemli ve temel unsur güneşin konumu ve güneşten gelen ışınım açılarıdır. Bu bağlamda, güneş ışınım açılarının fizik bilimi açısından ne ifade ettiği bu bölümde tanımlanmış ve temel bağlantılar verilerek detaylandırılmıştır. Tez kapsamında varolan bu açıların detaylandırılmasının yanısıra bu açıların tez konusu dahilinde olan ışınım hesaplamaları için mevcut önemi ve kullanımı ilerleyen bölümlerde görülmektedir. Öte yandan, tezin ikinci kısımına konu olmuş olan ışınım; ışınımın tanımı ve güneş ışınımının atmosferi geçip yeryüzüne gelene kadarki yolculuğundan bahsedilmiştir. Güneş enerjisi uygulamalarında önemli yere sahip olan anlık ve günlük güneş ışınım hesapları hem atmosfer dışı hem de yeryüzü için irdelenmiştir. Bunun yanısıra, yeryüzüne gelen ışınım, eğik ve yatay düzlem için anlık ve günlük detaylandırılmasının yanı sıra toplam, direk ve yaygın ışınım hesaplamaları olarak da anlatılmıştır. Her ne kadar tez kapsamında, yatay düzlem için günlük toplam güneş ışınım inceleme ve hesaplamalarına yer verilmiş olsa bahsi geçen diğer hesaplamaların teorik bilgisi bu bölüm kapsamındadır. Tezin üçüncü bölümü, deneysel çalışmanın detaylandırılmasını içermektedir. Öncelikle, teze konu olan Türkiye’nin güneş ışınım yapısının anlatılmasının yanı sıra metrekareye düşen ışınım değerleri rakamsal olarak yansıtılmıştır. Akabinde, ışınım değerlerine bağlı olarak ayrılan bölgeler tanımlanmıştır. Tez kapsamında, Türkiye 4 bölgede incelenmiş ve her bölge için yine ışınım değerlerine göre 5’ er istasyon belirlenmiştir. Bahsi geçen bölgeler ve istasyonlar tezin bu bölümünde detaylandırılmıştır. Öte yandan, literatür kısmında bahsedilen ve tez konusu dahilinde Türkiye’ nin belirli bölge ve/veya istasyonları için daha önce literatüre sunulan ve tez dahilinde irdelemek adına seçilen modeller yine bu kısımda detaylandırılmıştır. Modellerin konu olduğu çalışmalardan kısaca bahsedilmiştir. Modellerin formülleri ve formüllerin bağlı olduğu parametreler bu kısımda sunulmuş ve modeller ile ilgili açıklama yapılmış, var ise aynı modele ait alt formüllerin temsil ettiği hesaplama detaylandırılmıştır. Tezin hesaplama bölümü olan dördüncü bölümünde, Türkiye genelinde 4 bölge için seçilen 5’er istasyon görsel olarak sunulmuş ve her bir bölgenin tabii tutulduğu hesaplamalar açıklanmıştır. Detaylandırmak gerekirse, literatürden seçilen modeller 6 set halinde gruplanmış ve her bölgedeki istasyonlar için ayrı ayrı hesaplamaları yapılmıştır. Bu hesaplamalar sonucunda, her bir bölge için temsili bir istasyon seçilmiştir. Tezin bu kısmında seçili istasyonların yanı sıra tez çalışmasının geçtiği istasyon olan İstanbul’ un da hesaplamaları dahil edilmiştir. Seçili istasyonlar ve İstanbul istasyonu için model hesaplamaları grafiksel olarak sunulmuş ve grafiğin ortaya çıkması konusunda uygulanan modeller her bir hesaplama sonucu için tablolar dahilinde detaylandırılmıştır. Dördüncü bölümde, yukarıda anlatılan her bölge için seçili istasyonların literatür modellerinin irdelenmesinin yanı sıra, modellerin her bir bölge ve her bölgedeki her bir istasyon için uygunluk durumlarının irdelenmesi adına literatürde en sık kullanılan istatistiksel analiz metodları altında incelenmiş ve tezin bu kısmına dahil edilmiştir. Her bir bölge için yapılan bu irdelemeler tablolar halinde sunulmuştur. Tezin yine dördüncü bölümünde, İstanbul ve seçili istasyonlar için yatay düzleme gelen günlük güneş ışınımına dair hesaplanan ve ölçülen değerler irdelenmiştir. Bu çalışma akabinde İstanbul ve her bölgenin seçili istasyonuna ait yeni modeller korelasyon faktörü ile ortaya konulmuştur. Tezin son kısmında, yapılan çalışma doğrultusunda ortaya çıkan sonuçlara değinilmiş, varılan nokta tartışmış ve yapılan çalışmaya dair sonuç çıkarılmıştır. Güneş enerjisinin önemine değinilmiş ve teknolojisinin gelişimi yatırımlar açısından rakamlarla kıyaslanmıştır. Öte yandan, ileriye dönük iyileştirme adına öneride bulunulmuştur. Akabinde, yapılan tez çalışması dahilinde her bir bölgede seçilen istasyonlar için makul olan model tayini yapılması adına istatistik açıdan değerlendirilmiş ve modeller kıyaslanmıştır. Öte yandan, tez konusu dahilinde olan Türkiye bölgesi için her bir bölgedeki seçilen istasyonlar ve tezin geçtiği istasyon olması açısından İstanbul istasyonu için ileri sürülen yeni korelasyonlar istatiksel olarak irdeleniş ve yorumlanmıştır, Energy demand led to solar energy and installing photovoltaic facilities become the mainstream power supplier today. Solar energy has become a trending topic not only for scientific researches but also for the governments and companies as well. Therefore, there have been conferences, meetings with regard to improvements of solar technology and science behind, meanwhile anaylsing the yearly situation of solar technology in terms of economic, legal and governmental aspects. However, there are some obstacles for investors that can not be ignored. The most important ones are installment costs and legal regulations. This situation force investors to do the right project before installation. Thereto, building solar plants with suitable setup to the correct geographic areas by utilizing information of solar radiation data is the start point of solar energy facility investment projects. In these premises several solar radiation models have been improved in order to estimate the solar radiation at a given location or larger areas. One of the main objective of this thesis is to review the solar radiation models available in the literature and evaluate for the defined regions and related stations in Turkey in order to develop new models. Therefore, this Master of Science Thesis aims to compares the models for several stations in four regions where the total solar radiation range varies by region. Further, thesis also aims to imply the statistical analysis methods in order to detect the most appropriate model. In the first part of this thesis, the improvements in the solar energy field are explained for Turkey and World. Besides, the current status of solar energy installed capacities are explained with numbers due to the yearly reports that published around the world by governments and solar energy related societies. Furthermore, literature reviewed in this thesis with regard to the models proposed to determine global solar radiation datas for specific or general regions. The studies published for the models, are detailed in the literature part of the first chapter. The investigation for solar plant installations has to be done scientifically for to define the most appropriate facility. Therefore, the physics of solar energy has major role. In this context, in the second chapter this thesis states, theorical knowledge of solar angular and radiation calculations. The descriptions of solar angles are detailed meanwhile the pathway of solar radiation through the atmosphere is explained. Besides the descriptions of physics of solar energy, the related fundamental equations of solar radiation are also defined. The daily extraterrestrial radiation fundamental equations are detailed meanwhile the daily solar radiation on horizontal surface is stated in this chapter that are within the topic of this thesis. Although the hourly fundamental calculations of solar radiation on horizontal and inclined surface are not the topic of this thesis, the global, direct and diffuse solar radiation are also detailed for the knowledge of the physics of solar radiation fundamentals. Further, in the third chapter, experimental study is explained by the description of the region and the global solar radiation calculation by models selected from the literature. The models that are evaluated in the literature are chosen which the studies enlightens as some station(s) within Turkey region. The third chapter summarize briefly the models and the studies that the models are purposed. Furthermore, the chapter defines the field that the thesis evolved. This thesis, includes Turkey region with four different solar radiation ranges which are named under regions. There are 5 stations for each region that are evaluated under the selected models. In the fourth chapter, calculations are detailed and 4 regions each 5 stations illustrated. Each station evaluated for selected models which are grouped by 6 sets of models. On the other hand, models are evaluated for each station of each region, but only Istanbul and one selected station for each region are illustrated by the model results figures. Further, statistical analysis results are shown for regions. By the end of fourth chapter, new models purposed by this Master of Science Thesis is given for selected stations and Istanbul, Turkey according to the measured and calculated data of the monthly average daily global radiation and the monthly average maximum possible daily sunshine duration. In the conclution, the importance of solar energy is stated and the improvements around the world are evaluated by means of report datas. Furthermore, forecasts are given for the improvents of solar energy field. In the following, the models are compared by the statistical analysis results of each selected station. At the end, the purposed models by this thesis are evaluated by the statistical analysis methods., Yüksek Lisans, M.Sc.

Little empirical data exist on the surface temperatures of the keystone saguaro cactus Carnegiea gigantea despite its well documented adaptations for reducing direct solar radiation and heating. In this study, I document temperatures on the surface of individuals on their ridges and furrows, at two different heights above the ground, in the sun and in the shade and at two sites, in two seasons (winter and summer), based on a total of over 4200 surface temperature readings. ANOVA was used for statistical comparisons. Temperatures are generally warmer lower on the plant, likely due to heating from the ground from the ground below. The spiny ridges have more moderate temperatures than the furrows. Differences in temperature between these two groups were significant, but small. Seasonal differences between the sun-facing and shaded sides of the plants were significant. Temperature differences were much more pronounced during the winter than in the summer. The reasons for this are uncertain, but solar angle may be important, with the sun's rays shining more directly on the surface of this upright plant during the low solar angle months of winter, while in summer, the sun's rays arrive at a near-parallel angle to the plant and the energy is thus spread over a wider area, resulting in smaller temperature differences. Other factors may be important as well, such as photosynthetic changes in the plant, which may sometimes use the C3 pathway (rather than CAM) that would promote evaporative cooling.

Objective To monitor changes in hoof morphology in response to barefoot trimming. Methods Seven horses were trimmed every 6 weeks according to barefoot trimming principles, which involved levelling the hoof to live sole, lowering the heels, bevelling the toe and rounding the peripheral wall, while leaving the sole, frog and bars intact. A 4-month period was allowed to lower the heels sufficiently to achieve a hoof shape representative of the barefoot trim. This was regarded as the starting point for morphological adaptations in response to maintenance of the trim. Hoof morphology was measured from lateral, dorsal and solar view photographs and lateromedial radiographs taken at 0, 4 and 16 months. Changes from 0 to 4 months represented differences between a natural hoof shape and the trim, while changes from 4 to 16 months represented adaptive effects during hoof growth. Results Establishment of the barefoot trim involved significant shortening of the toe, heel and medial and lateral walls, with increases in angulation at the toe, medial and lateral walls, but not at the heel. Maintenance of the trim resulted in a palmar/plantar migration of the heels, with increases in support length, heel angle and solar angle of the distal phalanx (P3). Conclusions Bevelling the toe and engaging the frog and bars in the weight-bearing function of the foot resulted in elevation of the heel angle and solar angle of P3. These changes may be beneficial in treating under-run heels and negative solar plane angulation of P3.

Ultraviolet radiation (UVR; wave length, 280-400 nm) can be an important source of mortality for fish, particularly during early life history stages. Because UVR exposure varies seasonally owing to solar angle, climatic conditions, and changes in the UV transparency of water, UVR-induced mortality among temperate fishes may vary as a function of spawning time. We examined patterns of UVR exposure in nests of bluegill Lepomis macrochirus over the course of a spawning season in a highly transparent lake in northeastern Pennsylvania. At the beginning, middle, and end of the spawning season, we measured nest depth and estimated the cumulative UVR exposure of all bluegill nests along three 250-m transects. Cumulative exposure was then used to predict the UVR-induced mortality for bluegill larvae in each nest. The median UVR exposure in bluegill nests was highest at the start of the spawning season, and the predicted UVR-induced larval mortality was at least 10% in 38% of the nests. As the season progr...

A geometric algorithm has been developed for determining the hour lines and sun altitude concentric circles to be used in plotting the solar charts for any geographic latitude, and relevant mathematical formulas have been derived. The data presented in the developed tables and diagrams can be used in setting up a computer database for subsequent plotting of the solar charts.

The Green Solar Collector (GSC), a photobioreactor designed for area efficient outdoor cultivation of microalgae uses Fresnel lenses and light guides to focus, transport and distribute direct light into the algae suspension. Calculating the path of rays of light, so-called ray tracing, is used to determine local light intensities inside the photobioreactor based on the focused rays of sunlight. Reflection and refraction of the propagating rays of sunlight from point of focus to refraction into the photobioreactor is calculated. Refraction out of smooth and sandblasted distributor surfaces is simulated. For the sandblasted surface a specific structure is assumed and corresponding reflection and refraction patterns are described by a 2-dimensional modeling approach. Results of the simulations are validated by measurements on real light guide surfaces. The validated model is used to determine the influence of the solar angle on the uniformity and efficiency of light distribution over the light distributor surface. The simulations show that efficient capturing of sunlight and redistribution inside the algal biomass can be achieved in the Green Solar Collector at higher elevation angles of the sun, making the Green Solar Collector suitable for operation at low latitudes with a high level of direct irradiance.

The European light dosimeter network (ELDONET) comprisesmore than 40 stations in 24 countries on 5 continents. Thepresent report compares solar radiation data in the photosyntheticactive radiation, UV-A (315–400 nm) and UV-B (280–315 nm) wavelength ranges for 17 stations at different latitudeson the northern and southern hemispheres for up to 10 years ofmonitoring. While the maximal irradiances on clear days followa latitudinal gradient due to the cosine dependence on the solarangle, the total doses strongly depend on the local climate andatmospheric conditions as well as the day-length distribution overthe year. UV-B irradiances and doses are strongly influenced bythe total column ozone, which is recorded for all covered stations. Fil: Häder, Donat Peter. Universidad de Erlangen-Núremberg; Alemania Fil: Lebert, Michael. Universidad de Erlangen-Núremberg; Alemania Fil: Schuster, Martín Iván. Universidad de Erlangen-Núremberg; Alemania Fil: Del Ciampo, Lineu. Universidade da Regiao de Joinville; Brasil Fil: Helbling, Eduardo Walter. Fundación Playa Unión. Estación de Fotobiología Playa Unión; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: McKenzie, Richard. National Institute of Water and Atmospheric Research; Nueva Zelanda