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1
Trevarthen, Geo Athena. "Brightness of brightness : seeing Celtic shamanism." Thesis, University of Edinburgh, 2003. http://hdl.handle.net/1842/1700.
Повний текст джерелаАнотація:
Early Irish literature, other Celtic literatures and later folklore are rich with descriptions of personal contact with the sacred. The Otherworld, or spiritual aspect of reality, is a constant and vivid presence in the legends. This reality does not seem distant, but rather, always ready to break through into physical reality, transforming those who encounter it. In earlier times, druids, and sometimes heroes and saints, seem to function fully as shamans as described by Mircea Eliade in his definitive work on shamanism, undertaking spirit journeys into the Otherworld. and returning with gifts for their people. In later times, when overtly primal shamanic practice was increasingly repressed, personal contact with the sacred became in many cases less defined and more individual. However, we continue to see contact with the Otherworld in folklore. hagiography and the mystical experiences fostered by later spiritual movements. While scholars such as Carey, Nagy and Melia have recognised and explored some of the shamanic themes present in Early Irish literature, the full complex of these themes, along with their implications for our understanding of Early Irish and Celtic culture, have not yet been hlly examined. A holistic approach to these difficult issues indicates that one must not just dissect the texts themselves for meaning, but take into account the research of archaeologists, anthropologists, psychologists and neuroscientists as well as Celticists. By doing so, I hope to show not only the evidence for Celtic shamanism itself, but suggest possible fbnctions of shamanic experience in Early Irish, and more broadly, Celtic culture, Because shamanic traditions typically have a clear cosmology and ideas about spiritual growth, I have also considered if the early Irish and, more broadly, the Celts may have had such a cosmology and ideas of harmonising with the sacred they came into such intense contact with.
2
Ковальська, Вікторія Володимирівна. "Analysis of the light pollution in the city of Kyiv." Thesis, Національний авіаційний університет, 2020. https://er.nau.edu.ua/handle/NAU/49682.
Повний текст джерелаАнотація:
Робота публікується згідно наказу ректора від 21.01.2020 р. №008/од "Про перевірку кваліфікаційних робіт на академічний плагіат у 2019-2020 навчальному році". Керівник роботи: доцент кафедри екології, к.т.н., Радомська Маргарита Мирославівна<br>Object of research – processes of pollution formation under the influence of artificial light sources.
Aim оf work – assessment of the light pollution level and its impact on environment.
Mehods of research: methods of analysis of sky by Bortle scale; comparative analysis of the obtained values of light level in the Kyiv city<br>У наш час штучні джерела світла є невід’ємною частиною
сучасні міста. Однак проблема полягає в тому, що їх кількість значно перевищує необхідну
забезпечити достатній рівень освітлення на вулицях міста. У наш час проблема світла
забруднення міст стає все більш важливим, оскільки це питання погано регулюється
досудовий рівень. А вплив світлового забруднення відчуває і населення міста, і біота в цілому.
3
Ковальська, Вікторія Володимирівна. "Analysis of the light pollution in the city of Kyiv." Thesis, Національний авіаційний університет, 2020. https://er.nau.edu.ua/handle/NAU/44801.
Повний текст джерелаАнотація:
Робота публікується згідно наказу ректора від 21.01.2020 р. №008/од "Про перевірку кваліфікаційних робіт на академічний плагіат у 2019-2020 навчальному році". Керівник роботи: доцент кафедри екології, к.т.н., Радомська Маргарита Мирославівна<br>Object of research – processes of pollution formation under the influence of artificial light sources.
Aim оf work – assessment of the light pollution level and its impact on environment.
Mehods of research: methods of analysis of sky by Bortle scale; comparative analysis of the obtained values of light level in the Kyiv city<br>У наш час штучні джерела світла є невід’ємною частиною
сучасні міста. Однак проблема полягає в тому, що їх кількість значно перевищує необхідну
забезпечити достатній рівень освітлення на вулицях міста. У наш час проблема світла
забруднення міст стає все більш важливим, оскільки це питання погано регулюється
досудовий рівень. А вплив світлового забруднення відчуває і населення міста, і біота в цілому.
4
Naidoo, Darryl. "High brightness lasers." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97044.
Повний текст джерела
5
Robinson, Alan Edward. "Mechanisms of brightness perception." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3372643.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of California, San Diego, 2009.<br>Title from first page of PDF file (viewed Oct. 7, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 57-58).
6
Lim, Jun Jun. "Investigation of factors influencing the brightness of high-power, high-brightness laser diodes." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404050.
Повний текст джерела
7
Bulen, Jay C. "Brightness measures of trombone timbre /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/11279.
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8
Miller, Ian Patrick. "The brightened." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/1554.
Повний текст джерелаАнотація:
Thesis (M.F.A.) -- University of Maryland, College Park, 2004.<br>Thesis research directed by: Dept. of English. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
9
Mackenzie, Jacob Isa. "High-brightness diode-pumped waveguide lasers." Thesis, University of Southampton, 2003. https://eprints.soton.ac.uk/15482/.
Повний текст джерелаАнотація:
Reported in this thesis are advances toward high-brightness diode-pumped planar waveguide (PW) lasers. Efficient and compact planar waveguide lasers are made possible by their geometry, which is compatible with that of high-power diode lasers, has very good thermal management characteristics, and delivers high optical gains per unit pump power. Thus using the waveguide structure in conjunction with trivalent rare-earth ions, multi-Watt diffraction-limited operation of weak and quasi-three-level laser transitions can be obtained. Large mode area (LMA) double-clad planar waveguides, fabricated via direct bonding sapphire and YAG, are the primary structures investigated herein. These high numerical aperture waveguides are ideally suited to high-power diode-pumping due to a combination of features related to their slab-like configuration. Furthermore the LMA double-clad planar waveguide is shown to robustly select the fundamental waveguide mode. This general result leads to guided-diffraction-limited output, applicable to a range of oscillating wavelengths. Two in-plane pumping geometries are detailed; longitudinal or end-pumping and transverse or side-pumping. For end-pumping, the pump is conditioned in one axis to enable launching into the waveguide, and at the same time the free space axis is matched to the fundamental mode of a simple monolithic laser cavity. As such, efficient end-pumped operation of Nd:YAG, Yb:YAG, and Er:YAG LMA-PW lasers were realised. With Nd:YAG for 7.5W of absorbed pump power, 4.3W of CW 1.064µm output was observed. Changing the resonator mirrors to optimise the quasi-three level transition an output of 3.5W at 946nm was measured, corresponding to 6.5W of absorbed pump. In addition the much weaker and rarely studied 1.8µm transition, operated with as much as 0.4W. In a similar configuration, 0.45W of 2.7µm CW output was obtained from a highly doped Er:YAG LMA-PW with 4.6W of absorbed pump power. As the first Er:YAG waveguide laser to be reported, it illustrates the possibility to obtain high output power and good beam quality from weak laser transitions with these structures. Furthermore by integrating a Cr4+ saturable absorber into a Yb:YAG LMA-PW, an end-pumped passively Q-switched laser was demonstrated with 2.3W average power at 1.03µm in a near-diffraction-limited beam. Pulses of ~2ns temporal width at repetition rates approaching 80kHz produced peak powers of ~20kW. Operation of a similar Nd:YAG LMA PW laser, on both the 1.064µm and 946nm transitions, was also demonstrated and its performance shown to be inferior to that of the Yb3+doped structure in this pumping configuration. Using the side-pumping scheme higher-powers can be obtained, typically however, at the expense of the resonator complexity when trying to obtain high brightness performance. As such a monolithic Tm:YAG LMA-PW laser, pumped by two proximity-coupled diode bars, produced 15W at 2µm with an asymmetric low brightness beam, despite being diffraction-limited in the guided axis. In addition two separate Nd:YAG LMA-PW lasers were trialled with unstable and external resonator geometries. Watt level output powers with significantly enhanced brightness were observed. Further designs for power scaling these devices are discussed.
10
Rosenbaum, Dominik. "Low surface brightness galaxies and their environments." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=979834880.
Повний текст джерела
11
Sprayberry, David. "Cosmological implications of low surface brightness galaxies." Diss., The University of Arizona, 1994. http://hdl.handle.net/10150/187022.
Повний текст джерелаАнотація:
This dissertation briefly presents the results of a survey for galaxies that have been overlooked by previous surveys because their surface brightness, or brightness per unit area on the night sky, is too low. This dissertation then makes use of the survey results to estimate the density of these galaxies and to delineate some of their properties. Chapter 1 describes the selection bias against finding galaxies of low surface brightness and outlines the importance of these galaxies for a more complete knowledge of the true local galaxy population. Chapter 2 discusses the techniques employed for identifying low surface brightness (LSB) galaxies for the survey, calibrating the photometry, and estimating the survey incompleteness as a function of galaxy parameters. Chapter 3 presents luminosity functions for the low surface brightness galaxies identified in the present survey, and for a combined sample of low surface brightness and high surface brightness galaxies. The overall space density of low surface brightness galaxies is about one-fourth to one-third as great as the density determined from standard field galaxy luminosity functions, and that the total luminosity density due to these low surface brightness galaxies is about one-third to one-half the level derived from other surveys. Chapter 4 presents 21 cm profiles and CCD surface photometry for a subset of the low surface brightness spiral galaxies found by the survey. The general trend of the LSB galaxies in the Tully-Fisher relation, relative to the trend of higher surface brightness galaxies, forms the basis of the conclusion that LSB spiral generally have mass-to-light ratios comparable to that of higher surface brightness spirals but with a much larger scatter. Various possible reasons for the higher scatter are explored. Chapter 5 presents CCD surface photometry and optical spectroscopy for a sample of eight low surface brightness spiral galaxies that are extraordinary because of their large physical sizes and high total luminosities. The properties of these galaxies are analyzed and compared to those of more normal spirals. Chapter 6 summarizes the findings of the preceding chapters and presents some ideas for future investigations.
12
Rastogi, Mayank. "SeaWinds RADIOMETER BRIGHTNESS TEMPERATURE CALIBRATION AND VALIDATION." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3445.
Повний текст джерелаАнотація:
The NASA SeaWinds scatterometer is a radar remote sensor which operates on two satellites; NASA's QuikSCAT launched in June 1999 and on Japan's ADEOS-II satellite launched in December 2002. The purpose of SeaWinds is to provide global measurements of the ocean surface wind vector. On QuikSCAT, a ground data processing algorithm was developed, which allowed the instrument to function as a QuikSCAT Radiometer (QRad) and measure the ocean microwave emissions (brightness temperature, Tb) simultaneously with the backscattered power. When SeaWinds on ADEOS was launched, this same algorithm was applied, but the results were anomalous. The initial SRad brightness temperatures exhibited significant, unexpected, ascending/descending orbit Tb biases. This thesis presents an empirical correction algorithm to correct the anomalous SeaWinds Radiometer (SRad) ocean brightness temperature measurements. I use the Advanced Microwave Scanning Radiometer (AMSR) as a brightness temperature standard to calibrate and then, with independent measurements, validate the corrected SRad Tb measurements. AMSR is a well-calibrated multi-frequency, dual-polarized microwave radiometer that also operates on ADEOS-II. These results demonstrate that, after tuning the Tb algorithm, good quality SRad brightness temperature measurements are obtained over the oceans.<br>M.S.E.E.<br>Department of Electrical and Computer Engineering<br>Engineering and Computer Science<br>Electrical Engineering
13
Xia, Shanhong. "High brightness limited-area cathode electron guns." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321552.
Повний текст джерела
14
Dillon, Nicholas. "High brightness-sensitivity interferometry : techniques and applications." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.330165.
Повний текст джерела
15
Williams, Stephen Alexander. "Half-brightness measurements of candidate radiation sensors." Thesis, University of Louisiana at Lafayette, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10163329.
Повний текст джерелаАнотація:
<p> Ionizing radiation poses a significant challenge for human and robotic space missions. Practical luminescent sensors will depend heavily upon research investigating the resistance of these materials to ionizing radiation and the ability to anneal or self-heal the damage caused by such radiation. In 1951, Birks and Black experimentally showed that the luminescent efficiency of anthracene bombarded by alpha particles varies with total fluence. From 1990 to the present, we found that the Birks and Black relation describes the reduction in light emission yield for every tested luminescent material except lead phosphate glass due to proton irradiation. These results indicate that radiation produced quenching centers compete with emission for absorbed energy. The purpose of this thesis is to present new results from related luminescent materials by exposing them to a 1-3 MeV proton beam. Particular emphasis will be placed on recent measurements made with bright luminescent materials, such as zinc sulfide doped with manganese (ZnS:Mn), europium tetrakis dibenzoylmethide triethylammonium (EuD4TEA), an magnesium tetrakis dibenzoylmethide triethylammonium (MgD4TEA). This research can be used to help determine if luminescent materials can be used as a real-time sensor to detect ionizing radiation.</p>
16
MacCormack, Stuart. "Photorefractive techniques for diode laser brightness enhancement." Thesis, University of Southampton, 1991. https://eprints.soton.ac.uk/403318/.
Повний текст джерелаАнотація:
The experimental investigation of a number of techniques using photorefractive materials to increase the spectral and spatial brightness of the output from high power semiconductor laser arrays are discussed. The topics of semiconductor lasers and photorefractive materials are reviewed briefly, and the experimental and theoretical background of array transverse modes and laser array injection locking are discussed fully. Single longitudinal mode operation of a 100mW array coupled to a simple, hemispherical external cavity is reported. A side mode suppression ratio of 14dB was achieved. A spatial brightness enhancement by a factor of 10 is reported for a 1W laser array coupled to a phase conjugate external cavity. A number of techniques for the combination of multiple array outputs into a single beam were investigated. A power of 108mW (220mW, Fresnel corrected) was obtained in a diffraction limited, single mode laser beam using photorefractive two-beam coupling with an injection locked 1W laser array pump. Results on the operation of a reflection geometry phase conjugate master-oscillator, power-amplifier using a 500mW diode laser array are presented. The observation of coherent energy transfer between the outputs from the separate stripes of a laser array is discussed, and an external photorefractive beam combining element is proposed. Phase conjugate fidelity results are presented for a double pass, phase conjugate, multimode fibre amplifier geometry. The experiments suggest that phase conjugate modal unscrambling will still take place in the presence of ~6dB gain. A scheme for a high efficiency, high power multimode fibre amplifier is proposed.
17
Martin, Mhairi Ann. "High brightness light sources for defence applications." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2738.
Повний текст джерелаАнотація:
This thesis contains the results of the work that was carried out between February 2009 and September 2012 in the area of high brightness light sources for defence applications. The work follows two main themes, namely nonlinearity in optical fibres and optical parametric oscillators (OPOs). Initially, the prospect of creating an ultrafast light source from solid core microstructured fibre via the phenomenon of modulation instability is discussed alongside supercontinuum generation and its value as a broad bandwidth source in countermeasures. What follows concerns OPOs in the infrared, both external (extracavity) and internal (intracavity) to a laser cavity, with the former is of benefit for high power applications, whereas the latter allows the OPO to operate more effectively at lower powers. The extracavity OPO section discusses a 2-stage conversion from 1064nm to 2128nm with the second stage design for conversion to ~5000nm, and the intracavity work is directed at both enabling a single frequency source for spectroscopy and examining the relationship between output coupling and the resonant OPO and laser fields.
18
Malton, S. P. "Laser interactions with high brightness electron beams." Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1444964/.
Повний текст джерелаАнотація:
The International Linear Collider will be a high-precision machine to study the next energy frontier in particle physics. At the TeV energy scale, the ILC is expected to deliver luminosities in excess of 1034 cni" 2s_1. In order to achieve this, beam conditions must be monitored throughout the machine. Measurment of the beam emittance is essential to ensuring that the high luminosity can be provided at the interaction point. At the de sign beam sizes in the ILC beam delivery system, the Laserwire provides a non-invasive real-time method of measuring the emittance by the method of inverse Compton scattering. The prototype Laserwire at the PETRA stor age ring has produced consistent results with measured beam sizes of below 100 /nn. The Energy Recovery Linac Prototype (ERLP) is a technology testbed for the 4th Generation Light Source (4GLS). Inverse Compton scattering can be used in the ERLP as a proof of concept for a proposed 4GLS upgrade, and to produce soft X-rays for condensed matter experiments. The design constraints for the main running mode of the ERLP differ from those required for inverse Compton scattering. Suitable modifications to the optical lattice have been developed under the constraint that no new magnetic structures may be introduced, and the resulting photon distributions are described.
19
Dowsett, David Mark Francis. "High Brightness Ion Sources for Surface Analysis." Thesis, University of Warwick, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491929.
Повний текст джерелаАнотація:
The aim of this work was to produce an ion source with a high brightness and low energy spread. Two approaches were taken, an existing high brightness ion source (the liquid metal ion source) was monochromated to reduce its energy spread; this work was carried out at the University of York. The second approach was to develop a novel high brightness ion source with an intrinsically low energy spread. This approach was carried out at the University of Warwick. Several potential monochromators were simulated and the concentric hemispherical analyser was found to be the most suitable. Liquid metal ion sources were fabricated for monochromation by the author. However, these sources did not prove to be sufficiently stable for energy spread measurements and electron sources were used to try to demonstrate the principal. Ultimately this approach did not prove successful and the alternative ofdeveloping a novel source was pursued. This second approach utilises a novel emission process discovered at Warwick: surface enhanced field emission. Alkali metal vapours incident on a hot, chemically etched molybdenum wire are ionised at fields much lower than those normally required for field emission. Emission currents of several microamps have been obtained from the source and the sample current found to extremely stable with r.m.s noise of just 0.65%. The axial angular intensity of the source is 23 ~A sfl at 1 ~A emission. SIMS depth profiling has been carried out and the dynamic range at 1 keY was 3 orders of magnitude. Spot sizes of 20 ~m have been measured at 1 keY. The dynamic range and spot size do not represent the ultimate performance of the source, both are expected to improve in an ion column designed for a high brightness source.
20
Jeffers, Sandra Victoria. "Surface brightness distributions of late-type stars." Thesis, University of St Andrews, 2005. http://hdl.handle.net/10023/12941.
Повний текст джерелаАнотація:
The aim of this work has been to increase our understanding of the surface brightness distributions of late-type stars through Doppler imaging and eclipse mapping techniques. Combining spectroscopic and photometric observations with the technique of Doppler Imaging, I have reconstructed surface images of the G2V star He 699 (for 08 October 2000), which show high latitude and polar structures. In the case of the KOV star AB Dor, the Doppler images for January 1992 and November 1993 show a large polar cap with small dark features also present at intermediate to high latitudes. As the phase sampling of the observations was insufficient to apply the sheared-image method it was not possible to detect any differential rotation. In the second part of my thesis I determine the surface brightness distribution of the primary component of the RS CVn eclipsing binary SV Cam. I have used extrapolated size distributions of sunspots to an active star to synthesize images of stellar photospheres with high spot filling factors. The resulting surface images, reconstructed with the Maximum Entropy eclipse mapping technique, show large spurious spot features at the quadrature points. It is concluded that two-spot modelling or chi-squared minimisation techniques are more susceptible to spurious structures being generated by systematic errors, arising from incorrect assumptions about photospheric surface brightness, than simple Fourier analysis of the light-curves. Spectrophotometric data from 9 HST orbits, observed in November 2001, have been used to eclipse-map the primary component of SV Cam. In combination with its HIPPAR- COS parallax it is found that the surface flux in the eclipsed low-latitude region is about 30% lower than computed from the best fitting PHOENIX model atmosphere. This flux deficit can only be accounted for if about a third of the primary's surface is covered with unresolved spots. However, when the spottedness from the eclipsed region is applied to the entire surface of the primary star, there still remains an unaccounted flux deficit. The remaining flux deficit is explained by the presence of a large polar spot extending down to latitude 48+/-6 deg. When the Maximum Entropy eclipse mapping technique is used to fit SV Cam's lightcurve, the observed minus computed residuals show strong spurious peaks at the quadrature points. It is only possible to reduce these peaks with the addition of a polar cap and the reduction of the primary star's temperature, to account for the star being peppered with unresolvable spots. Motivated by this result we investigate the limb darkening of the primary component of SV Cam. The wavelength dependence of the limb darkening is analysed by sub-dividing the HST lightcurve into 10 bands of equal emission flux. Flux variations between the first and fourth contact of the primary eclipse indicate that the limb darkening decreases towards longer wavelengths, in accordance with published limb darkening laws. Comparing fits of ATLAS and PHOENIX model atmospheres we find a wavelength dependence of the best fitting model. Due to its smooth cutoff at the stellar limb, the spherical geometry of the PHOENIX model atmosphere gives the best fit during partial eclipse. Between the second and third contact the difference between spherical and plane-parallel geometry is less important.
21
Okumi, Shoji, Naoto Yamamoto, Kuniaki Tamagaki, et al. "Development of the New Type Polarized Electron Source for SPLEEM." American Institite of Physics, 2007. http://hdl.handle.net/2237/11990.
Повний текст джерела
22
Kabore, Jean Yves. "ANALYIS OF AIRBORNE MICROWAVE POLARIMETRIC RADIOMETER MEASUREMENTS IN THE PRESENCE OF DYNAMIC PLATFORM ATTITUDE ERRORS." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2571.
Повний текст джерелаАнотація:
There are numerous applications for airborne imaging systems in remote sensing, and this thesis deals with a new microwave polarimetric radiometer technique for inferring ocean surface wind direction [3, 5, 7]. This technique is based upon the anisotropy of the polarized ocean blackbody emissions at microwave frequencies relative to the azimuth angle between the microwave radiometer antenna "look" direction and the direction of the wind. Because of the weak wind direction signature, it is important that all systematic brightness temperature (Tb) errors be eliminated, especially those that vary with the radiometer antenna scan position (look direction). This can be accomplished either in hardware implementation or through data processing corrections. Unfortunately, the misalignment of the axis of rotation for a conical-scanning imager can introduce such azimuthally dependent errors of significant magnitude. As the title suggests, the analysis of the resulting Tb errors caused by static and dynamic time-varying aircraft attitude errors is the main thrust of this thesis. In this thesis, we present analytical models developed to account for platform attitude changes on measured ocean microwave brightness temperature collected by a conically scanning radiometer. Data processing procedures for removing unwanted variations in ocean brightness temperatures are outlined. The analytical models are validated by making comparisons between modelled and measured Tb's obtained by the Conically Scanning Two-Look Airborne Radiometer (C-STAR). Results demonstrated that the analytical Tb model can accurately predict the measured polarized Tb's under actual flight conditions.<br>M.S.E.E.<br>Department of Electrical and Computer Engineering<br>Engineering and Computer Science<br>Electrical Engineering
23
Sakurai, Junichi. "Fuzzy stuff detection method : LSB galaxy auto scanning program on DPOSS /." view abstract or download file of text, 2000. http://wwwlib.umi.com/cr/uoregon/fullcit?p9986755.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of Oregon, 2000.<br>Typescript. Includes vita and abstract. Includes bibliographical references (leaves 94-96). Also available for download via the World Wide Web; free to University of Oregon users.
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Walker, Craig Lee. "Quantum well intermixing for high brightness semiconductor lasers." Thesis, University of Glasgow, 2002. http://theses.gla.ac.uk/4019/.
Повний текст джерелаАнотація:
The research presented in this thesis describes how monolithic opto-electronic integration using quantum well intermixing (QWI) can be applied to improve the high brightness performance of single-mode ridge waveguide GaAs/AlGaAs quantum well (QW) lasers. The sputtered SiO2 QWI technique is explained, and a selective process suitable for device manufacture was demonstrated. This QWI technology was applied to create three distinct devices to address the performance limitations imposed by catastrophic optical damage (COD), spatial mode instability, and overheating. A non absorbing mirror (NAM) laser technology was successfully demonstrated, capable of significantly improving the COD level of high power lasers prone to mirror degradation. Under pulsed test conditions designed to induce COD, the standard ridge laser suffered COD at 230 mW/facet, compared to 600 mW/facet for the NAM laser, demonstrating an improved COD level by a factor of 2.6. Confirmation of the COD failure mechanism was achieved by facet inspection, and removal of the damaged facets. Successful demonstration of a high brightness single lateral mode ridge laser with a self-aligned buried heterostructure defined by QWI was achieved. The device benefits from de-coupling of the optical and electrical confinement, allowing enhanced fundamental lateral mode operation up to higher powers; the buried heterostructure improves the lateral mode discrimination, thus suppressing higher order modes. Comparison of the standard ridge laser and the buried heterostructure ridge laser for ridge widths of 5 mm clearly demonstrated the improvement gained; the standard ridge laser was too wide to operate in the fundamental mode, whereas the buried heterostructure ridge laser showed dominantly single-mode operation up to 130 mW/facet.
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Mingee, Catherine M. "Retention of brightness discrimination in Paramecia, P. caudatum /." Connect to full text in OhioLINK ETD Center, 2009. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1258397377.
Повний текст джерелаАнотація:
Thesis (M.A.)--University of Toledo, 2009.<br>Typescript. "Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Master of Arts Degree in Psychology." "A thesis entitled"--at head of title. Bibliography: leaves 17-18.
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Fife, Keith G. (Keith Glen) 1974. "A stereo vision system with automatic brightness adaptation." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/9438.
Повний текст джерелаАнотація:
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.<br>Includes bibliographical references (p. 67-69).<br>This thesis describes the development of an automatic brightness adaptive imaging system for use in stereo vision algorithms implemented for a variety of processing architectures. A 256 x 256 array of wide dynamic range pixels with on-chip A/D converters provides the digital data path for a feedback network which controls the charge integration parameters at each pixel. The first goal of the project was to build a real-time demonstration of the imager with configurable compression functions. Secondly, electronic irising was employed by controlling the global charge integration time based on the average intensity of the image. In addition to electronic-irising, the imaging system employs a linear or a logarithmic compression scheme based on the image data. The controller fits the compression function to the image by comparing the average intensities of many different regions within the image. Finally, a 3-camera stereo-vision system was developed with data transfer to a PC through the PCI bus at 60fps. The imagers are synchronized and controlled based on the center imager's data which allows for consistent object correlation in stereo vision algorithms.<br>by Keith G. Fife.<br>S.B.and M.Eng.
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Kim, Yong-Guk. "Visual surface representation for transparency, occlusion and brightness." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.624737.
Повний текст джерела
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Cobley, Andrew Joseph. "The use of insoluble anodes in horizontal conveyorized printed circuit board manufacture : their effect on the performance and electrochemistry of acid copper electroplating solutions." Thesis, Loughborough University, 2002. https://dspace.lboro.ac.uk/2134/34016.
Повний текст джерелаАнотація:
The use of insoluble anodes has become critical to the viability of horizontal electroplating equipment. Despite this there have been few reported studies on the impact of using such anodes on the electrochemistry of acid copper plating solutions. A literature search therefore reviewed the different types of insoluble anode that had been previously utilized in sulphuric acid-based electrolytes and from this a number of criteria were established that might be applied when selecting an insoluble anode for horizontal acid copper electroplating. A 'life study' was then carried out to compare two electroplating baths, one operating with standard copper anodes, and the other insoluble anodes.
29
Marshall, James J. "A large survey for very low surface brightness galaxies." College Park, Md. : University of Maryland, 2004. http://hdl.handle.net/1903/2049.
Повний текст джерелаАнотація:
Thesis (Ph. D.) -- University of Maryland, College Park, 2004.<br>Thesis research directed by: Astronomy. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
30
Hanna, Rafik. "VALIDATION OF QUICKSCAT RADIOMETER (QRAD) MICROWAVE BRIGHTNESS TEMPERTURE MEASURMENTS." Doctoral diss., University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3990.
Повний текст джерелаАнотація:
After the launch of NASA's SeaWinds scatterometer in 1999, a radiometer function was implemented in the Science Ground Data Processing Systems to allow the measurement of the earth's microwave brightness temperature. This dissertation presents results of a comprehensive validation to assess the quality of QRad brightness temperature measurements using near-simultaneous ocean Tb comparisons between the SeaWinds on QuikSCAT (QRad) and WindSat polarimetric radiometer on Coriolis. WindSat was selected because it is a well calibrated radiometer that has many suitable collocations with QuikSCAT; and it has a 10.7 GHz channel, which is close to QRad frequency of 13.4 GHz. Brightness temperature normalizations were made for WindSat before comparison to account for expected differences in Tb with QRad because of incidence angle and channel frequency differences. Brightness temperatures for nine months during 2005 and 2006 were spatially collocated for rain-free homogeneous ocean scenes (match-ups) within 1° latitude x longitude boxes and within a ± 60 minute window. To ensure high quality comparison, these collocations were quality controlled and edited to remove non-homogenous ocean scenes and/or transient environmental conditions, including rain contamination. WindSat and QRad Tb's were averaged within 1° boxes and these were used for the radiometric inter-calibration analysis on a monthly basis. Results show that QRad calibrations are stable in the mean within ± 2K over the yearly seasonal cycle.<br>Ph.D.<br>School of Electrical Engineering and Computer Science<br>Engineering and Computer Science<br>Electrical Engineering PhD
31
Holdsworth, Adrian Richard. "Brightness conserving optical systems for high power diode lasers." Thesis, Heriot-Watt University, 1999. http://hdl.handle.net/10399/583.
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Ugarte, Urra Ignacio. "Brightness and magnetic evolution of solar coronal bright points." Thesis, Queen's University Belfast, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419415.
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Schwartzenberg, Jean Marc. "Field and cluster surveys for low surface brightness galaxies." Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336873.
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Kim, Ji Hoon. "The star formation history of low surface brightness galaxies." College Park, Md.: University of Maryland, 2007. http://hdl.handle.net/1903/7646.
Повний текст джерелаАнотація:
Thesis (Ph. D.) -- University of Maryland, College Park, 2007.<br>Thesis research directed by: Dept. of Astronomy. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Schmeißer, Martin Anton Helmut. "Photocathodes for high brightness, high average current photoelectron injectors." Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/20481.
Повний текст джерелаАнотація:
Für viele Anwendungen in der Grundlagenforschung, Medizin und industriellen Entwicklung sind Beschleuniger der entscheidende Antrieb. Vor allem Elektronenbeschleuniger sind als Synchrotronquellen unter den brillantesten Quellen für Strahlung im Infrarot- bis Röntgenbereich und damit unerlässlich für eine Vielzahl von Anwendungen und analytischen Methoden. Photoinjektoren stellen als Elektronenquellen für Beschleuniger eine wichtige Komponente für die Entwicklung von Lichtquellen wie Freie-Elektronen-Laser, sowie für neue Beschleunigerkonzepte wie Linearbeschleuniger mit Energierückgewinnung dar. Die Photokathode und der Anregungslaser definieren dabei mit der Quantenausbeute (QE) und der intrinsischen Emittanz zentrale Kenngrößen des Photoinjektors.
Diese Arbeit beschreibt die Entwicklung von Alkali-Antimonid Photokathoden für die Anwendung in einem Photoinjektor mit supraleitendem Hochfrequenz-Resonator. Alkali Antimonide zeigen generell eine hohe QE und Cäsium Kalium Antimonid (Cs-K-Sb) im speziellen verspricht eine geringe intrinsische Emittanz aufgrund der Ionisierungsenergie, die nur knapp unter der Photonenenergie der grünen Anregungslaser liegt.
Mit der Inbetriebnahme eines Präparations- und Analysesystems konnte die Abscheidung dünner Schichten von Cs-K-Sb sowie die Messung der QE und chemischen Zusammensetzung erzielt werden. Dabei wurde mit der Ko-evaporation der Alkalimetalle eine neue Wachstumsmethode etabliert und hinsichtlich der Prozessstabilität und Qualität der erzeugten Proben mit der sequenziellen Methode verglichen.
Schließlich beschreiben die Inbetriebnahme eines Prototyps des Photoinjektors und erste erfolgreiche Kathodentransfers im Vakuum einen wichtigen Schritt hin zum Betrieb eines Beschleunigers mit einer Cs-K-Sb Photokathode im supraleitenden Hochfrequenz-Injektor. Diese Kombination erlaubt die Erzeugung eines Elektronenstrahls mit niedriger Emittanz und hohem mittleren Strom.<br>For many disciplines in basic and applied research, medicine and industrial development accelerators are an important driving force. Especially electron accelerators as synchrotron sources are among the brightest sources of radiation from the infrared to the X-ray regime and thus fundamental to a broad range of analytical techniques. Photoinjectors as electron sources for accelerator applications are a key component for the development of light sources such as free electron lasers as well as new accelerator concepts like energy-recovery linacs. The photocathode and drive laser define the quantum efficiency (QE) and intrinsic emittance of the photoemission process and thus central figures of merit of the photoinjector.
This work focuses on the development of alkali antimonide photocathodes for the application in a superconducting radio frequency photoinjector.
Alkali antimonides generally exhibit a high QE and cesium potassium antimonide (Cs-K-Sb) specifically is expected to release electrons with a low intrinsic emittance as the photoemission threshold is close to the photon energy of common, green, drive laser wavelengths.
A preparation and analysis system has been commissioned for the deposition of Cs-K-Sb thin film photocathodes and their analysis regarding QE and chemical composition. A new deposition technique, the alkali metal co-deposition, was established and compared to the sequential deposition in terms of process reliability and quality of the produced samples.
The work concludes with a report of the commissioning of a prototype of the photoinjector and successful cathode transfers in ultra-high vacuum, which represents an important technological advancement towards the operation of an accelerator with the combination of Cs-K-Sb photocathodes and an SRF injector. This combination makes the generation of an electron beam with low emittance and high average current possible.
36
Boyajian, Tabetha S., Roi Alonso, Alex Ammerman, et al. "The First Post-Kepler Brightness Dips of KIC 8462852." IOP PUBLISHING LTD, 2018. http://hdl.handle.net/10150/626540.
Повний текст джерелаАнотація:
We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and " Angkor," which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar spectrum or polarization during the dips and (ii) the multiband photometry of the dips shows differential reddening favoring non-gray extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale << 1 mu m, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process.
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Салех, Ахмед Оссама, та Ahmed Ossama Saleh. "Проектування освітлення автотранспортного тунелю". Bachelor's thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2021. http://elartu.tntu.edu.ua/handle/lib/35492.
Повний текст джерелаАнотація:
Based on the analysis of the international standards of lighting of motor
transport tunnels the generalization of the basic directions of increase of
economy, safety and comfort of lighting is carried out. The normative
indicators of illumination and brightness in different zones of the tunnel
depending on its parameters and characteristics of road traffic taking into
account features of light adaptation of a human eye are systematized. Different types of lighting of motor tunnels depending on the purpose of
lighting, location of lighting fixtures, direction and intensity of road traffic
are analyzed. Based on the analysis of lighting and electrical parameters of light sources,
the expediency of their use for different types of tunnel lighting is
substantiated.<br>На основі аналізу міжнародних стандартів освітлення автотранспортних тунелів проведено узагальнення основних напрямків підвищення економічності, безпечності та комфортності освітлення, систематизовано нормативні показники освітленості та яскравості в різних зонах тунелю в залежності від його параметрів і характеристик дорожнього руху з врахуванням особливостей світлової адаптації ока людини. Проаналізовано різні види освітлення автотранспортних тунелів залежно від призначення освітлення, розміщення світлових приладів, напрямку та інтенсивності руху автомобільного транспорту. На основі аналізу світлотехнічних та електричних параметрів джерел світла обґрунтовано доцільність їх використання для різних видів освітлення тунелю. Проведено порівняння характеристик світлових приладів з розрядними і напівпровідниковими джерелами світла. Розглянуто можливість ступінчатого та плавного регулювання освітленості тунелю в нічний час доби. Обгрунтовано доцільність застосування ступінчатого регулювання освітленості при використанні розрядних джерел світла та можливість плавного і ступінчатого регулювання освітленості при використанні напівпровідникових джерел світла. Розроблено схему освітлення автотранспортного тунелю з врахуванням особливостей світлової адаптації ока людини при різних параметрах тунелю, інтенсивності автомобільного руху, часу доби.<br>Based on the analysis of the international standards of lighting of motor transport tunnels the generalization of the basic directions of increase of economy, safety and comfort of lighting is carried out. The normative indicators of illumination and brightness in different zones of the tunnel depending on its parameters and characteristics of road traffic taking into account features of light adaptation of a human eye are systematized. Different types of lighting of motor tunnels depending on the purpose of lighting, location of lighting fixtures, direction and intensity of road traffic are analyzed. Based on the analysis of lighting and electrical parameters of light sources, the expediency of their use for different types of tunnel lighting is substantiated. The characteristics of luminaires with discharge lamps of high pressure and LED are compared. Methods of light regulation in tunnels are analyzed, their advantages and disadvantages are established, recommendations on use for different types of lighting installations are given. The scheme of illumination of the motor transport tunnel is developed taking into account features of light adaptation of a human eye at various parameters of the tunnel, intensity of automobile traffic, time of day.<br>INTRODUCTION 6
1 ANALYTICAL SECTION 8
1.1 Types of road tunnels and it’s relation with the lighting
requirements and their characteristics
8
1.2 Ways to increase the efficiency of lighting tunnels 23
1.3 Conclusions to section 1 26
2 CALCULATION AND RESEARCH SECTION 27
2.1 Lighting devices for road tunnels 27
2.2 Placement of luminaires in tunnels 35
2.3 Methods of light control 37
2.3.1 Stepwise adjustment of the light level 38
2.3.2 Smooth adjustment of light level 40
2.4 Conclusions to section 2 47
3 PROJECT DESIGNING SECTION 48
3.1. Lighting calculation of a lighting installation for a transport tunnel 48
3.2. Adjusting the luminous flux of the lighting installation 60
3.3 Comparison of energy efficiency of the developed lighting
installations
61
3.4 Conclusions to section 3 64
4 LABOUR OCCUPATIONAL SAFETY AND SECURITY IN
EMERGENCY SITUATIONS 66
4.1. Safety requirements for the installation of lighting fixtures 66
4.2. The effect of electric current on humans. First aid for electric injuries 67
4.3 Influence of electromagnetic fields on the human body 70
GENERAL CONCLUSIONS FOR QUALIFICATION WORK 73
REFRENCES 75
38
Rouiller, Vanessa. "Sonaecom: challenging present, brighter future." Master's thesis, NSBE - UNL, 2011. http://hdl.handle.net/10362/10446.
Повний текст джерела
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Zhao, Dongyao. "Evolution of the brightest cluster galaxies." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/35927/.
Повний текст джерелаАнотація:
In this thesis, I explore the evolution of the brightest cluster galaxies (BCGs) over the last 10 billion years through detailed studies of both local BCGs from SDSS and their high-z progenitors from CANDELS UDS. First, I study a large sample of local BCGs and link their morphologies to their structural properties. We derive visual morphologies for these BCGs and find that ~57% of local BCGs are cD galaxies, ~13% are ellipticals, and ~21% belong to intermediate classes, mostly between E and cD. There is a continuous distribution in the properties of the BCG's envelopes, ranging from undetected (elliptical BCGs) to clearly detected (cD galaxies), with intermediate classes showing increasing degrees of the envelope presence. A minority (~7%) of BCGs have disk morphologies, with spirals and S0s in similar proportions, and the rest (~2%) are mergers. After carefully fitting the galaxy light distributions using Sersic models, I find a clear link between BCG morphology and structure, such that cD galaxies are typically larger than elliptical BCGs, and the visually extended envelope of cD galaxies is a distinct structure differing from the central bulge. Based on this BCG morphology--structure correlation, I develop a statistically robust way to separate cD from non-cD BCGs, by which cD galaxies can be selected with reasonably high completeness and low contamination. Next, I investigate the effect of environment on the properties of local BCGs by studying the relationship between the BCG's internal properties (stellar mass, structure and morphology) and their environment (local density and cluster halo mass). I find that the size of BCGs is determined by the intrinsic BCG stellar mass, with a weak correlation with the cluster environment. Additionally, more massive BCGs tend to inhabit denser regions and more massive clusters than lower mass BCGs. The growth of the BCGs seems to be linked to the hierarchical growth of the structures they inhabit: as the groups and clusters became denser and more massive, the BCGs at their centres also grew. Moreover, I demonstrate that cD galaxies are ~40% more massive than elliptical BCGs, and prefer denser regions and more massive haloes. My results, together with the findings of previous studies, suggest an evolutionary link between elliptical and cD BCGs. I propose that most present-day cDs started their life as ellipticals at z~1, which subsequently grew in stellar mass and size due to mergers. In this process, the cD envelope developed. This process is nearing completion since the majority of the local BCGs have cD morphology. However, the presence of BCGs with intermediate morphological classes suggests that the growth and morphological transformation of BCGs is still ongoing. Finally, I present a new method for tracing the evolution of BCGs from z~2 to z~0. I conclude, on the basis of semi-analytical models, that the best method to select BCG progenitors at z~2 is a hybrid environmental density and stellar mass ranking approach. Ultimately I am able to retrieve 45% of BCG progenitors. Although the selected high-z progenitor sample is a mixture of BCG and non-BCG progenitors, I demonstrate that their properties can be used to trace BCG evolution. Applying this method to the CANDELS UDS data, I construct an observational BCG progenitor sample at z~2. A local BCG comparison sample is constructed using the SDSS data, taking into account the likely contamination from non-BCGs to ensure a fair comparison between high-z and low-z samples. Using these samples I demonstrate that BCG sizes have grown by a factor of ~3.2 since z~2, and BCG progenitors are mainly late-type galaxies, exhibiting less concentrated profiles than their early-type local counterparts. I also find that BCG progenitors have more disturbed morphologies, while local BCGs have much smoother profiles. Moreover, I find that the stellar masses of BCGs have grown by a factor of ~2.5 since z~2, and the SFR of BCG progenitors has a median value of ~14 Msun/yr, much higher than their quiescent local descendants. I demonstrate that at 1 < z < 2 star formation and merging contribute approximately equally to BCG mass growth. However, merging plays a dominant role in BCG assembly at z < 1. I also find that BCG progenitors at high-z are not significantly different from other galaxies of similar mass at the same epoch. This suggests that the processes which differentiate BCGs from normal massive elliptical galaxies must occur at z < 2.
40
Whiley, Ian M. "Evolution of the brightest cluster galaxies." Thesis, University of Nottingham, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489698.
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Reineke, Sebastian. "Controlling Excitons: Concepts for Phosphorescent Organic LEDs at High Brightness." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-39520.
Повний текст джерелаАнотація:
This work focusses on the high brightness performance of phosphorescent organic light-emitting diodes (OLEDs). The use of phosphorescent emitter molecules in OLEDs is essential to realize internal electron-photon conversion efficiencies of 100 %. However, due to their molecular nature, the excited triplet states have orders of magnitude longer time constants compared to their fluorescent counterparts which, in turn, strongly increases the probability of bimolecular annihilation. As a consequence, the efficiencies of phosphorescent OLEDs decline at high brightness – an effect known as efficiency roll-off, for which it has been shown to be dominated by triplet-triplet annihilation (TTA). In this work, TTA of the archetype phosphorescent emitter Ir(ppy)3 is investi- gated in time-resolved photoluminescence experiments. For the widely used mixed system CBP:Ir(ppy)3, host-guest TTA – an additional unwanted TTA channel – is experimentally observed at high excitation levels. By using matrix materials with higher triplet energies, this effect is efficiently suppressed, however further studies show that the efficiency roll-off of Ir(ppy)3 is much more pronounced than predicted by a model based on Förster-type energy transfer, which marks the intrinsic limit for TTA. These results suggest that the emitter molecules show a strong tendency to form aggregates in the mixed film as the origin for enhanced TTA. Transmission electron microscopy images of Ir(ppy)3 doped mixed films give direct proof of emitter aggregates. Based on these results, two concepts are developed that improve the high brightness performance of OLEDs. In a first approach, thin intrinsic matrix interlayers are incorporated in the emission layer leading to a one-dimensional exciton confinement that suppresses exciton migration and, consequently, TTA. The second concept reduces the efficiency roll-off by using an emitter molecule with slightly differ- ent chemical structure, i.e. Ir(ppy)2(acac). Compared to Ir(ppy)3, this emitter has a much smaller ground state dipole moment, suggesting that the improved performance is a result of weaker aggregation in the mixed film. The knowledge gained in the investigation of triplet-triplet annihilation is further used to develop a novel emission layer design for white organic LEDs. It comprises three phosphorescent emitters for blue, green, and red emission embedded in a multilayer architecture. The key feature of this concept is the matrix material used for the blue emitter FIrpic: Its triplet energy is in resonance with the FIrpic excited state energy which enables low operating voltages and high power efficiencies by reducing thermal relaxation. In order to further increase the device efficiency, the OLED architecture is optically optimized using high refractive index substrates and thick electron transport layers. These devices reach efficiencies which are on par with fluorescent tubes – the current efficiency benchmark for light sources<br>Diese Arbeit richtet ihren Fokus auf die Untersuchung der Leistungsfähigkeit von phosphoreszenten, Licht-emittierenden organischen Dioden (OLEDs) im Bereich hoher Betriebshelligkeiten. Phosphoreszente Emittermoleku ̈le werden in OLEDs eingesetzt, um interne Elektron-Photon Konversionseffizienzen von 100% zu erreichen. Begründet in ihrer chemischen Struktur, weisen die angeregten Triplett-Zustände dieser Emitter um Größenordnungen längere Zeitkonstanten als die Emission fluo- reszenter Materialien auf, sodass die Wahrscheinlichkeit bimolekularer Auslöschung stark ansteigt. Dies resultiert in einem deutlichen Effizienzrückgang phosphoreszenter OLEDs bei großen Leuchtdichten. Dieser als Roll-off bekannter Effekt wird bei hohen Anregungsdichten hauptsächlich durch Triplett-Triplett Annihilation (TTA) bestimmt. In der Arbeit wird TTA an einem Modellmolekül, dem phosphoreszenten Emit- ter Ir(ppy)3, in zeitaufgelösten Photolumineszenz Experimenten untersucht. Für das bekannte Emittersystem CBP:Ir(ppy)3 wird bei hohen Anregungsdichten Host-Guest TTA beobachtet, was einen zusätzlichen, ungewünschten TTA Kanal darstellt. Dieser Effekt wird durch das Verwenden von Matrix Materialien mit höherer Triplett Energie vermieden, jedoch zeigt sich in weiteren Untersuchungen, dass der Roll-off deutlich stärker ist als von einem auf Förster Energieübertrag basierendem Modell vorhergesagt, welches selbst ein intrinsisches Limit für TTA in phosphoreszenten Systemen beschreibt. Die Diskrepanz zwischen experimenteller Beobachtung und Modellvorhersage wird durch eine starke Tendenz des Emitters, Aggregate zu bilden, erklärt, was TTA deutlich verstärkt. Diese Aggregate werden mit Hilfe von Transmissionselektronenmikroskopie an Ir(ppy)3-dotierten Mischsystemen direkt nachgewiesen. Basierend auf diesen Resultaten werden zwei Konzepte entwickelt, um die Effizienz phosphoreszenter Systeme bei hohen Helligkeiten zu verbessern. Im ersten Ansatz werden dünne intrinsische Schichten des Matrixmaterials in die Emissionsschicht eingebaut, was die Exzitonenbewegung in einer Raumrichtung und damit auch TTA stark unterdrückt. Das zweite Konzept reduziert den Effizienz Roll-off durch die Verwendung eines phosphoreszenten Emitters Ir(ppy)2(acac) mit einer leicht abgeänderten Molekularstruktur. Im Vergleich mit Ir(ppy)3 weist dieser ein deutlich kleineres Dipolmoment im molekularen Grundzustand auf, wodurch die Aggregation vermindert wird. Aufbauend auf den Ergebnissen der TTA wird ein neuartiges Emissionsschicht-Design für weißes Licht entwickelt. In diesem Konzept werden drei phosphoreszente Materialien für blaue, grüne und rote Farbe in eine Vielschicht-Architektur eingebracht. Das Hauptmerkmal der Emissionsschicht ist die Wahl des Matrix-Materials für dem blauen Emitter FIrpic: Seine Triplett Energie liegt resonant zu dem FIrpic Triplett Zustand, wodurch niedrige Betriebsspannungen und hohe Leistungseffizienzen ermöglicht werden, da die thermische Relaxierung reduziert wird. Um die Ef- fizienz dieser weißen OLEDs weiter zu erhöhen, wird die entwickelte OLED Architektur zusätzlich durch die Verwendung von hochbrechenden Substraten und dicken Elektronen-Transportschichten optisch optimiert. Bei beleuchtungsrelevanten Helligkeiten erreichen diese OLEDs das Effizienzniveau von Leuchtstoffröhren – letztere stellen heute den Effizienz-Maßstab dar
42
Otendal, Mikael. "A Compact High-Brightness Liquid-Metal-Jet X-Ray Source." Doctoral thesis, Stockholm, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4005.
Повний текст джерела
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Nilsson, David. "Prediction of wood species and pulp brightness from roundwood measurements." Doctoral thesis, Umeå : Univ, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-605.
Повний текст джерела
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Huang, Wen-Chih, and 黃文志. "《Adversity, Miraculous brightnes, Mindfield 》: Application of photomontage technique in the creation of image design for presenting the religious carnival of faithful pilgrims follow Dajia Mazu Procession." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/33qp45.
Повний текст джерелаАнотація:
碩士<br>國立臺灣藝術大學<br>視覺傳達設計學系碩士班<br>101<br>The creation of the study focused on Dajia Mazu Procession, adopting textual analysis to reveal the history and cultural scene of Dajia Mazu Pilgrimage, conducting direct observation to photograph and collect data as the image material for the study. In addition, using case study to analyze content of Mazu-related artworks of Taiwan artists and interpreting creative ideas of artworks adopting photomontage technique by worldwide photography artists.
The creation of the study use photomontage techniques, imitating the spirit of oriental painting of Long Chin-San’s composite photography works and poetic beauty of Jerry Uelsmann's(1934 ∼) artworks, presenting the enthralling images of pilgrimage troupe by using digital image composition technique to cut, combine, and collage photographs. Using the Chinese long handscroll's banner type to frame the artwork and expand the space and time of the image presentation, and applying Roland Barthes' semiotic theory to analyze and interpret the study. The researcher hopes the underlying meaning of three themes of the artwork--"Adversity", "Miraculous brightness", "Mindfield" can touch viewers deeply and move them to find their own value of life, and become the co-creation between the study and viewers.
The creation process of the study lasted for two years participation and photo shooting during the procession in 2011 and 2012. The recorded results can apply to art creations and the follow-up research as reference materials; with the booming development of modern day's cultural and creative industry of Taiwan, the author anticipates that the final presentation of the study can apply to cultural creative product, and become the advertising resource of cultural tourism marketing of Dajia Mazu Procession Festival.
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Šťástka, Jindřich. "Konvektivní bouře a vodní pára ve spodní stratosféře." Doctoral thesis, 2018. http://www.nusl.cz/ntk/nusl-388347.
Повний текст джерелаАнотація:
Title: Convective storms and lower stratospheric moisture Author: Jindřich Šťástka Department: Department of Atmospheric Physics Supervisor: RNDr. Martin Setvák, CSc., Czech Hydrometeorological Institute Abstract: The primary focus of this thesis is to diagnose contributions to upper tropo- spheric and lower stratospheric (UTLS) water vapor from convective storms. The first parts of this work introduces two approaches used for a detection of lower stratospheric water vapor above convective storm tops - brightness temperature difference (BTD) technique and EOS MLS measurements. The BTD technique is based on brightness temperature difference between the water vapor absorp- tion and infrared window bands, assuming a thermal inversion above the cloud top level. The most frequently offered explanation of positive BTD values above convective storms is presence of warmer water vapor in the lower stratosphere. Furthermore, so called BTD anomalies were described and it was proposed an algorithm for objective detection of such BTD anomalies. Characteristics of pa- rameters describing BTD, BTD anomaly, infrared window brightness temperature were investigated during storms evolution on dataset of 320 storms from the area of Europe. The analysis of these characteristics proved highly probable conection between positive...
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Chih-Chi, Hsu, and 許芝綺. "A dwelling in infinite brightness." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/94905817533027597548.
Повний текст джерелаАнотація:
碩士<br>國立臺南藝術大學<br>應用藝術研究所<br>96<br>The exposition of the work, “A dwelling in infinite brightness” was written during the period from 2004 to 2008. It took my state of life as the background. Through the writing and rearrangement of thinking, I intended to clarify the axis of creation and the possibility of future development.
I once approached “A dwelling in infinite brightness,” and would like to own “A dwelling in infinite brightness” now.
When the verb “approach” turns to be an adjective, it is a process for a new-born baby to undergo metamorphosis, sense the reality of life, and get close to socialization. Over my pure belief in life, and my questioning of social value system, I respond to myself through the way of labor by creation. Sense organs and intuition are used to break the powerful and rational boundary of thinking as well as the habitual standard of single value. The flowing space is used to accept, load and digest the state of mind. They are all imprisoned in the mutual penetration of reality and illusion. In the vaguely moving environment of the reality, the possible outline of self can be portrayed. The purity forgotten and forsaken by the progress of life as well as the value neglected by the social reality can be retrieved. They are the directions that I pay concern for when facing life.
My creation at the present stage is not merely an expression of personal feeling, or the narcissist and self-destructive twittering. I attempt to use the state contrived by space to symbolize the time that the individual of life is situated at, and the internal feeling when facing the external environment. They are expected to be transformed as self-consciousness and the exploration of the original nature of life.
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Qiu, Zun-Rong, and 邱俊榮. "IC Processed Brightness Enchancement Films." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/01718394564769272737.
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Wen, Tzu-Chu, and 溫子鉅. "High-Brightness AlGaInP LEDs Performance Evaluation." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/50324202437272110530.
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碩士<br>國立高雄應用科技大學<br>電子與資訊工程研究所碩士班<br>93<br>Recently, high-brightness LEDs have been applied to traffic signs and lighting equipment, because they have the advantages of low power consumption, low cost, and long life in comparison to the traditional lighting devices. Hence, the improvement of LED’s performance that includes life time and brightness of the device is very important.
In this work, the reliability tests for 620nm-AlGaInP LEDs with difference sizes and circumstances were studied. Our results show that three passivation mechanisms affect device reliability, that are: (1) surface passivation of LED caused by the epoxy coverage, (2) hydrogen passivation from bulk, and (3) hydrogen passivation caused by diffusion from epoxy coverage. Here, the surface passivation has the quickest characteristic time, and, however, the hydrogen passivation caused by epoxy coverage requires the longest time, especially as the device with a large area operated under the environment temperature of 85℃. The characteristic times were extracted by use of curve fitting method.
Furthermore, our results show that the bevel corners to the top capping layer can effectively reduce the critical angle loss and relax the stress at the interface between semiconductor and epoxy.
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Yang, Kai-Jen, and 楊凱仁. "The Research of Solar Brightness Controller." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/34644088049979331131.
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碩士<br>吳鳳科技大學<br>光機電暨材料研究所<br>99<br>This proposed solar brightness controller can not only control the charging current and charging voltage but also the cut-off of the battery for the load by detecting the voltage of the battery. In addition, the proposed controller provides the functions of the operation time and illumination model. The proposed controller automatically adjusts the illumination of the lights with the brightness of the environment, so as to achieve the energy conservation. One use a LCD to show the information of the charging current and the voltage of the solar and the battery, in order is the users see the condition of the proposed one.
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Lin, Yan-Hong, and 林諺宏. "Lighting Design of High Brightness LED." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/16455819550633633209.
Повний текст джерелаАнотація:
碩士<br>崑山科技大學<br>電子工程研究所<br>99<br>Light-emitting-diode(LED) compared with traditional fluorescent tube has many advantages, such as high reliahility, longer using time, small power consumption, and so on. Hence,LED has the most promising potential for future solid-state lighting. This thesis estimated the LED lighting replacement in the interior space. Thus, the author mainly uses Computer aided design (CAD) software was used to accomplish this task accurately&effectively. In space lighting design, optimal number of lamps should be decided to achieve the best brightness. Using the manufacturers’ specification of various lighting models, we can achieve the desired lighting requirements designed by the software. According the Much time and money can be saved without field test. Then in accordance with domestic and international lighting standards, the performance of existing fluorescent and LED lightings can be compared to access their effectiveness.