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Solar tracking

Ching-Chuan Wei, Yu-Chang Song, Chia-Chi Chang, Chuan-Bi Lin
Solar energy is certainly an energy source worth exploring and utilizing because of the environmental protection it offers. However, the conversion efficiency of solar energy is still low. If the photovoltaic panel perpendicularly tracks the sun, the solar energy conversion efficiency will be improved. In this article, we propose an innovative method to track the sun using an image sensor. In our method, it is logical to assume the points of the brightest region in the sky image representing the location of the sun...
November 25, 2016: Sensors
Benjamin Merkel, Richard A Phillips, Sébastien Descamps, Nigel G Yoccoz, Børge Moe, Hallvard Strøm
BACKGROUND: The use of light level loggers (geolocators) to understand movements and distributions in terrestrial and marine vertebrates, particularly during the non-breeding period, has increased dramatically in recent years. However, inferring positions from light data is not straightforward, often relies on assumptions that are difficult to test, or includes an element of subjectivity. RESULTS: We present an intuitive framework to compute locations from twilight events collected by geolocators from different manufacturers...
2016: Movement Ecology
Vratislav Cmiel, Josef Skopalik, Katerina Polakova, Jan Solar, Marketa Havrdova, David Milde, Ivan Justan, Massimiliano Magro, Zenon Starcuk, Ivo Provaznik
In the last few years, magnetically labeled cells have been intensively explored, and non-invasive cell tracking and magnetic manipulation methods have been tested in preclinical studies focused on cell transplantation. For clinical applications, it is desirable to know the intracellular pathway of nanoparticles, which can predict their biocompatibility with cells and the long-term imaging properties of labeled cells. Here, we quantified labeling efficiency, localization, and fluorescence properties of Rhodamine derivatized superparamagnetic maghemite nanoparticles (SAMN-R) in mesenchymal stromal cells (MSC)...
November 26, 2016: European Biophysics Journal: EBJ
Mia Catharine Mattioli, Lauren M Sassoubre, Todd L Russell, Alexandria B Boehm
The decay of sewage-sourced enterococci, Escherichia coli, three human-associated microbial source tracking (MST) markers, Salmonella, Campylobacter, and norovirus GII was measured in situ in coastal, marine waters. Experiments examined the effects of sunlight intensity and season on decay. Seawater was seeded with untreated sewage, placed into permeable dialysis bags, and deployed in the coastal ocean near the water surface, and at 18 cm, and 99 cm depths, to vary solar intensity, during winter and summer seasons...
January 1, 2017: Water Research
Almis Serbenta, Oleg V Kozlov, Giuseppe Portale, Paul H M van Loosdrecht, Maxim S Pshenichnikov
Morphology of organic photovoltaic bulk heterojunctions (BHJs) - a nanoscale texture of the donor and acceptor phases - is one of the key factors influencing efficiency of organic solar cells. Detailed knowledge of the morphology is hampered by the fact that it is notoriously difficult to investigate by microscopic methods. Here we all-optically track the exciton harvesting dynamics in the fullerene acceptor phase from which subdivision of the fullerene domain sizes into the mixed phase (2-15 nm) and large (>50 nm) domains is readily obtained via the Monte-Carlo simulations...
November 8, 2016: Scientific Reports
Jinshan Xu, Shaocong Gan, Song Li, Zhongyuan Ruan, Shengyong Chen, Yong Wang, Changgui Gui, Bin Wan
Designs leading to maximize the use of sun radiation of a given reflective area without increasing the expense on investment are important to solar power plants construction. We here provide a method that allows one to compute shade area at any given time as well as the total shading effect of a day. By establishing a local coordinate system with the origin at the apex of a parabolic dish and z-axis pointing to the sun, neighboring dishes only with [Formula: see text] would shade onto the dish when in tracking mode...
2016: SpringerPlus
Nazmiye Cemre Birben, Ayse Tomruk, Miray Bekbolet
Solar photocatalytic disinfection efficiency of novel visible light activated (VLA) photocatalysts was evaluated with the aim of assessing inactivation of Escherichia coli as the pathogen indicator organism present in drinking water. Influence of humic acid (HA) on the photocatalytic disinfection efficiency of the specified VLA TiO2 specimens i.e., N-doped, Se-doped, and Se-N co-doped TiO2 was also investigated. Photocatalytic disinfection efficiency was assessed by the enumeration of bacteria following selected irradiation periods...
October 6, 2016: Environmental Science and Pollution Research International
Michael Saliba, Taisuke Matsui, Konrad Domanski, Ji-Youn Seo, Amita Ummadisingu, Shaik M Zakeeruddin, Juan-Pablo Correa-Baena, Wolfgang R Tress, Antonio Abate, Anders Hagfeldt, Michael Grätzel
All of the cations currently used in perovskite solar cells abide by the tolerance factor for incorporation into the lattice. We show that the small and oxidation-stable rubidium cation (Rb(+)) can be embedded into a "cation cascade" to create perovskite materials with excellent material properties. We achieved stabilized efficiencies of up to 21.6% (average value, 20.2%) on small areas (and a stabilized 19.0% on a cell 0.5 square centimeters in area) as well as an electroluminescence of 3.8%. The open-circuit voltage of 1...
October 14, 2016: Science
Rui Liu, Zuoliang He, Jiefang Sun, Jingfu Liu, Guibin Jiang
Plasmonic catalysis is an emerging process that utilizes surface plasmon resonance (SPR) process to harnesses solar energy for the promotion of catalyzed reactions. In most cases, SPR generated hot electrons (HEs) play an indispensable role in this solar-chemical energy shift process. Therefore, understanding the effectiveness of the HEs in promoting chemical reactions, and identifying the key factors that contribute to this utilization efficiency is of profound importance. Herein, the authors outline an in situ surface enhanced Raman spectroscopy protocol to track the fate of HEs...
December 2016: Small
D Liang, J Almeida, C R Vistas
A large aspheric fused silica lens was used to couple efficiently the concentrated solar radiation from the focal zone of a 1.5-m-diameter primary concentrator into a 4-mm-diameter, 35-mm-long Nd:YAG single-crystal rod within a conical pump cavity. Continuous-wave laser power of 29.3 W was measured, attaining 25.0  W/m<sup>2</sup> solar laser collection efficiency, corresponding to a 19% increase over the previous record. Its laser beam figure of merit-the ratio between laser power and the product of Mx2, My2 beam quality factors-of 0...
September 20, 2016: Applied Optics
Gregor Hülsen, Julian Gröbner, Saulius Nevas, Peter Sperfeld, Luca Egli, Geiland Porrovecchio, Marek Smid
One major objective of the European Joint Research Project "Traceability for surface spectral solar ultraviolet (UV) radiation" was to reduce the uncertainty of spectral UV measurements. The measurement instrument used for this work was the portable UV European reference spectroradiometer Qasume. The calibration uncertainty of this instrument was decreased and validated by a comparison of direct calibrations against a primary standard for spectral irradiance, a high temperature blackbody radiator, and against a reference detector using a spectrally tunable laser as a monochromatic source...
September 10, 2016: Applied Optics
Robert H Coridan, Zebulon G Schichtl, Tao Sun, Kamel Fezzaa
Semiconductor-liquid junctions are ubiquitous in photoelectrochemical approaches to artificial photosynthesis. By analogy with the antennae and reaction centers in natural photosynthetic complexes, separating the light-absorbing semiconductor and electrocatalysts can improve catalytic efficiency. A catalytic layer can also impair the photovoltage-generating energetics of the electrode without appropriate microscopic organization of catalytically active area on the surface. Here, we have developed a method using high-speed X-ray phase contrast imaging to study in situ electrolytic bubble growth on semiconductor electrodes fabricated with isolated, micron-scale platinum electrocatalysts...
September 21, 2016: ACS Applied Materials & Interfaces
Taisuke Matsui, Ieva Petrikyte, Tadas Malinauskas, Konrad Domanski, Maryte Daskeviciene, Matas Steponaitis, Paul Gratia, Wolfgang Tress, Juan-Pablo Correa-Baena, Antonio Abate, Anders Hagfeldt, Michael Grätzel, Mohammad Khaja Nazeeruddin, Vytautas Getautis, Michael Saliba
Triarylamine-based polymers with different functional groups were synthetized as hole-transport materials (HTMs) for perovskite solar cells (PSCs). The novel materials enabled efficient PSCs without the use of chemical doping (or additives) to enhance charge transport. Devices employing poly(triarylamine) with methylphenylethenyl functional groups (V873) showed a power conversion efficiency of 12.3 %, whereas widely used additive-free poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) demonstrated 10...
September 22, 2016: ChemSusChem
Sarah J C Simon, Fraser G L Parlane, Wesley B Swords, Cameron W Kellett, Chuan Du, Brian Lam, Rebecca K Dean, Ke Hu, Gerald J Meyer, Curtis P Berlinguette
We report here an enhancement in photovoltage for dye-sensitized solar cells (DSSCs) where halogen-bonding interactions exist between a nucleophilic electrolyte species (I(-)) and a photo-oxidized dye immobilized on a TiO2 surface. The triarylamine-based dyes under investigation showed larger rate constants for dye regeneration (kreg) by the nucleophilic electrolyte species when heavier halogen substituents were positioned on the dye. The open-circuit voltages (VOC) tracked these kreg values. This analysis of a homologous series of dyes that differ only in the identity of two halogen substituents provides compelling evidence that the DSSC photovoltage is sensitive to kreg...
August 24, 2016: Journal of the American Chemical Society
Jing Zhao, Benjamin A Nail, Michael A Holmes, Frank E Osterloh
Surface photovoltage spectroscopy (SPS) was used to study the photochemistry of mercaptoethanol-ligated CdSe quantum dot (2.0-4.2 nm diameter) films on indium doped tin oxide (ITO) in the absence of an external bias or electrolyte. The n-type films generate negative voltages under super band gap illumination (0.1-0.5 mW cm(-2)) by majority carrier injection into the ITO substrate. The photovoltage onset energies track the optical band gaps of the samples and are assigned as effective band gaps of the films...
September 1, 2016: Journal of Physical Chemistry Letters
Hagop S Atamian, Nicky M Creux, Evan A Brown, Austin G Garner, Benjamin K Blackman, Stacey L Harmer
Young sunflower plants track the Sun from east to west during the day and then reorient during the night to face east in anticipation of dawn. In contrast, mature plants cease movement with their flower heads facing east. We show that circadian regulation of directional growth pathways accounts for both phenomena and leads to increased vegetative biomass and enhanced pollinator visits to flowers. Solar tracking movements are driven by antiphasic patterns of elongation on the east and west sides of the stem...
August 5, 2016: Science
Matthew T Dunstan, Serena A Maugeri, Wen Liu, Matthew G Tucker, Oluwadamilola O Taiwo, Belen Gonzalez, Phoebe K Allan, Michael W Gaultois, Paul R Shearing, David A Keen, Anthony E Phillips, Martin T Dove, Stuart A Scott, John S Dennis, Clare P Grey
Carbon capture and storage (CCS) offers a possible solution to curb the CO2 emissions from stationary sources in the coming decades, considering the delays in shifting energy generation to carbon neutral sources such as wind, solar and biomass. The most mature technology for post-combustion capture uses a liquid sorbent, amine scrubbing. However, with the existing technology, a large amount of heat is required for the regeneration of the liquid sorbent, which introduces a substantial energy penalty. The use of alternative sorbents for CO2 capture, such as the CaO-CaCO3 system, has been investigated extensively in recent years...
October 20, 2016: Faraday Discussions
Joel R Norris, Robert J Allen, Amato T Evan, Mark D Zelinka, Christopher W O'Dell, Stephen A Klein
Clouds substantially affect Earth's energy budget by reflecting solar radiation back to space and by restricting emission of thermal radiation to space. They are perhaps the largest uncertainty in our understanding of climate change, owing to disagreement among climate models and observational datasets over what cloud changes have occurred during recent decades and will occur in response to global warming. This is because observational systems originally designed for monitoring weather have lacked sufficient stability to detect cloud changes reliably over decades unless they have been corrected to remove artefacts...
August 4, 2016: Nature
C E DeForest, T A Howard, D F Webb, J A Davies
A polarizing heliospheric imager is a critical next generation tool for space weather monitoring and prediction. Heliospheric imagers can track coronal mass ejections (CMEs) as they cross the solar system, using sunlight scattered by electrons in the CME. This tracking has been demonstrated to improve the forecasting of impact probability and arrival time for Earth-directed CMEs. Polarized imaging allows locating CMEs in three dimensions from a single vantage point. Recent advances in heliospheric imaging have demonstrated that a polarized imager is feasible with current component technology...
January 2016: Space Weather: the International Journal of Research & Applications
Yajie Wang, Yunbo Shi, Xiaoyu Yu, Yongjie Liu
Currently, tracking in photovoltaic (PV) systems suffers from some problems such as high energy consumption, poor anti-interference performance, and large tracking errors. This paper presents a solar PV tracking system on the basis of an improved perturbation and observation method, which maximizes photoelectric conversion efficiency. According to the projection principle, we design a sensor module with a light-intensity-detection module for environmental light-intensity measurement. The effect of environmental factors on the system operation is reduced, and intelligent identification of the weather is realized...
2016: PloS One
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