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Arctic and Midlatitude Stratospheric Trace Gas Measurements Using Ground-based UV-visible SpectroscopyFraser, Annemarie 26 February 2009 (has links)
A ground-based, zenith-sky, UV-visible triple grating spectrometer was installed at the Polar Environment Atmospheric Research Laboratory (PEARL) in the Canadian High Arctic during polar springtime from 2004 to 2007 as part of the Canadian Arctic ACE (Atmospheric Chemistry Experiment) Validation Campaigns. From the solar spectra,
ozone, NO2, and BrO vertical column densities (VCDs) have been retrieved using the DOAS (Differential Optical Absorption Spectroscopy) technique. This spectrometer, the UT-GBS (University of Toronto Ground-Based Spectrometer), was also deployed as part of the fourth Middle Atmosphere Nitrogen TRend Assessment (MANTRA) campaign in Vanscoy, Saskatchewan in August and September 2004.
A near-identical spectrometer, the PEARL-GBS, was permanently installed at PEARL
in August 2006 as part of the refurbishment of the laboratory by CANDAC (Canadian
Network for the Detection of Atmospheric Change). Since then, the instrument has been
making continuous measurements, with the exception of during polar night. Vertical
columns of ozone and NO2 can be retrieved year-round. During the 2007 sunrise campaign,
differential slant column densities (DSCDs) of OClO and VCDs of BrO were also
retrieved.
Ozone and NO2 DSCDs and VCDs from the UT-GBS were compared to the DSCDs and VCDs from three other UV-visible, ground-based, grating spectrometers that also participated in the MANTRA and Eureka campaigns. Two methods developed by the UV-visible Working Group of the NDACC (Network for the Detection of Atmospheric Composition Change) were followed. During MANTRA, the instruments were found to partially meet the NDACC standards. The comparisons from Eureka were an improvement on the MANTRA comparisons, and also partially met the NDACC standards. In 2007, the columns from the UT-GBS and PEARL-GBS were compared, and were found to agree within the NDACC standards for both species.
Ozone and NO2 VCDs from the ground-based instruments were also compared to
integrated partial columns from the ACE-FTS (ACE-Fourier Transform Spectrometer)
and ACE-MAESTRO (ACE-Measurements of Aerosol Extinction in the Stratosphere
and Troposphere Retrieved by Occultation) on board the ACE satellite. ACE-FTS partial
columns were found to agree with the ground-based total columns, while the ACE-MAESTRO
partial columns were found to be smaller than expected for ozone and larger than expected for NO2.
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Fabrication of a soft magnetic toroidal core using electrodeposition and UV-lithographySällström, Pär January 2009 (has links)
No description available.
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Sambandet mellan bestrykningsrecepturoch sänkningen av ytansvithet vid UV-lackningSjöström, Henrik January 2005 (has links)
AssiDomän tillverkar kartong till förpackningsindustrin. Inom detta område är vitheten på kartongytanen viktig parameter. För att höja intrycket av förpackningen samt skapa en skyddande yta lackas ofta förpackningen med UV-lack efter tryck. Efter lackning kan då otryckta lackade ytor uppfattas som mindre vita. För att ta reda på om bestrykningssammansättningen har betydelse har ett fem olika bestrykningar blandats. Pigmenten som använts i bestrykningarna är karbonat, kaolin och titandioxidi olika kombinationer. Kartong har sedan bestrukits med dessa och därefter lackerats med UV-lack. Lackningen har gjorts i tre olika lackmängder. Mätningar har sedan gjorts gällande framförallt vithet. Den samverkan som sker mellan ljus, materialet och dess struktur är av stor vikt för att skapa en yta med goda optiska egenskaper. Resultaten i detta försök visar att lacken påverkar de optiska egenskaperna och framförallt vitheten. De lackerade ytorna fick en gulton efter lackering vilket kan ha att göra med lackens egenskaper. Vitheten hade en något mindre minskning för den bestrykning som bestod av karbonat och titandioxid. Skillnaden var dock mycket liten då alla bestrykningar fick en sänkning av vitheten med cirka 11-13 procentenheter oberoende av utgångsvärdet i vithet för respektive bestrykning innan lackning. Positivt var att det kunde konstateras att den bestrykning som hade det högsta vithetsvärdet före lackning också hade det efter lackning med ett normalt lackpålägg vilket betyder att en hög vithet är av betydelse även om den bestrukna ytan ska lackas. Den sänkning av vitheten som sker kan ha flera tänkbara orsaker. En tänkbar orsak kan vara att lacken förstör den porösa struktur som ger den viktiga ljusspridningen i bestrykningsskiktet. Resultaten visar också att lackens egenskaper tycks vara av stor betydelse. Den gulton som framträdde efter lackning tyder på en ökad absorption av vissa ljusvåglängder. Något som också pekar på detta är att alla fem bestrykningarna fick en liknande sänkning av vitheten. För att säga exakt vad som är orsaken eller vilken kombination som påverkar vitheten mest krävs ytterliggare tester. Olika UV-lacker kan testas eftersom endast en UV-lack har använts i dessa försök. En närmare studie av gränsyta mellan UV-lacken och bestrykningsskiktet bör också göras för att se hur lacken påverkar bestrykningsskiktets struktur.
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Troubleshooting med avseende på avsättningar på gummiduk, Bobergs tryckeri ABÅkesson, Lars January 2004 (has links)
Bobergs printing house in Falun has during some time had problems regarding deposits on blankets intheirs Müller Martini UV-printing presses. Deposits appear in both image areas and non-image areas.These areas have been analyzed and the deposits on non-image areas contain chalk, clay and talc. Thequestion remains how these material bond to the blanket surface. The chalk and clay comes from thepaper. The talc comes from the ink. Deposits from image areas contain pigment and talc from the printingink. The dampening water has also been analyzed. The result shows some sort of problem with thehardness regulator for the clean water. The pH-level should be increased a few steps.
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Fundamental Mechanisms in the Extreme UV Resistance of AdenovirusEischeid, Anne January 2009 (has links)
<p>The adenoviruses are nonenveloped double stranded DNA viruses, which cause enteric dysentary and respiratory infection. Adenovirus has become a focus of the water treatment community because of its apparent resistance to ultraviolet disinfection; it is the basis for stringent new EPA regulations regarding all viruses in both surface and ground waters. Most of the work done so far, however, has involved the use of monochromatic (254 nm) low pressure (LP) UV sources and subsequent assay of viral infectivity in cell culture models. LP UV lamps primarily damage DNA, while polychromatic UV sources may damage other parts of the virus as well. Recent research has shown that these newer, polychromatic UV sources--such as medium pressure (MP) UV--are more effective than monochromatic LP UV for disinfection of adenovirus. The objectives of this work were to study adenoviral response to UV using both LP and MP UV as well as using both standard cell culture infectivity assays and more direct methods of assessment based on molecular biology. These include quantitative long PCR for assessment of DNA damage and SDS-PAGE for assessment of protein damage; transmission electron microscopy was used to examine the structure of UV treated viral particles. This work was only the second significant study to show the response of adenoviruses to medium pressure UV and the first to thoroughly examine the response of adenoviruses to both LP and MP UV using cell culture-independent methods. Results confirm that adenovirus is sensitive to MP UV when assayed in cell culture; they show that LP and MP UV are equally effective at inducing damage to the adenoviral genome and that MP UV is more effective than LP UV at damaging the viral proteins. This work helps deepen our understanding of UV disinfection of adenovirus.</p> / Dissertation
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The study of Zn1-x-yAlxTiyO thin film grown by UV assistant RF-sputteringCheng, Yu-chi 23 August 2011 (has links)
The most widely used transparent conducting thin films, Indium-Tin-Oxide (ITO), will surly encounter difficulties for Indium is naturally limited and its price rising fast very year. Searching for Indium free transparent conducting oxides (TCO) becomes one of the important issues in this field. Among of which, ZnO:Al (AZO) is the most import candidate and is used, now, in photovoltaic industry. In the future, flexible substrates are necessary, therefore, to preventing degrading of TCO crystal by repeatedly bending, TCO should be produced in amorphous or nano-crystal types. By properly doping of Ti in ZnO lattice, a certain form of amorphous-nanocrystal mixture films can be obtained at room temperature. Unfortunately, amorphous or nano-crystal with poor crystal structure suppress the electric conduction. Growth films at few hundred degrees may enhance the crystallization, however, the flexible substrate, such as PET, can only sustained temperature lower than 150oC. In this project, an UV assisted film growth technique is used to study the effect of the UV assistant growth on films properties. The aim of this study is wish to grow films with better crystallization at lower growth temperature.
Physical properties of films are investigated by the transmittance spectroscopy (N&K analyzer), X-ray dffractometer (XRD) and atomic force microscopy (AFM). It is found that the optical band gap increases and shows an obvious blue shifting due to the short range order in the present films. All films exhibits high level of transparency in the visible range. The grazing angle incident X-ray diffraction (GID XRD) indicates that high ratio of amorphous phase for films grown at high working gas pressure and low RF power. For certain growth conditions, pure amorphous films can be obtained. Oppositely, films grown at low working gas pressure and high RF power manifest crystal growth along all directions resulting shifting and broadening in XRD peaks. Higher the Ti doping levels higher the amorphous ratio. By gown films at higher temperatures, (002) peak dominates the GID XRD measurements. It is found that the 266nm UV assisted growth enhances crystallization and roughness of films at relatively low temperature, lower than the highest sustainable temperature of PET.
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Photoluminescence Characteristics of ZnO Thin Films by Reactive RF Magnetron SputteringKuo, Yi-Nan 07 July 2004 (has links)
In this study, the reactive rf magnetron sputtering was used to deposit zinc oxide (ZnO) thin films on Si substrate. The optimal sputtering parameters for film as luminescence application were found to be oxygen concentration (O2/O2+Ar) of 21%, RF power of 100W, substrate temperature of 500¢XC and sputtering pressure of 5 mtorr. Beside, the thermal treatment procedure was carried out to improve the luminescence characteristics of ZnO thin films.
The physical characteristics of ZnO thin films deposited on Si substrate with different sputtering parameters were obtained by the analyses of XRD and SEM. The optical properties of ZnO thin films were discussed also. Ultraviolet (UV) visible spectrometer and photoluminescence spectrometer were used to measure the visible transmission and photoluminescence characteristics (PL), respectively.
According to the experimental results, it is found that under optimal sputtering parameters, the emitted UV light intensity will be increased as the FWHM in x-ray diffraction is decreased, i.e. the grain size is larger. In addition, after post-deposition annealing at 800¢J, the strongest UV emission intensity was obtained in the nitrogen ambient and the strongest visible (green) emission intensity was obtained in the oxygen ambient.
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Study on the treatment of PCB Wastewater by Ferrite Process combined with Fenton¡¦s Method and UV/H2O2Chen, Chin-Yang 28 June 2006 (has links)
Biological and physical chemistry treatment methods always are used to remove COD of organic wastewater contains PCB. The effect is not obvious when the compositions of pollutant are too refractory or complicated. The primary treatment method of wastewater containing copper is chemical coagulation/sedimentation and its disadvantage is producing a large of sludge.
The objective of this study, using two combinative method of UV/H2O2-Ferrite Process and Fenton-Ferrite Process, is to remove organic compounds and heavy metal in real wastewater. Not only supernatant liquid could meet the standard of discharge wastewater but also produce general(non-hazardous) industrial wastes of heavy metal.
The primary operation condition of Fenton and UV/H2O2 process, was ferrous ion and hydrogen peroxide concentration, pH, reaction time, and chemical dosing, searching best operation condition to combine with Ferrite Process. Operation of Fenton and UV/H2O2 process under acid condition (pH=2) and neutral condition (pH=8) showed the best operation condition of Fenton and UV/H2O2. The removal decreased when the dose of hydrogen peroxide was added too more or too less.
As Fenton and UV/H2O2 process test finished, Ferrite Process is next used for treatment of heavy metal wastewater; Ferrite Process conducted as three stages and the operation conditions were controlled with temperature, pH and the ratio of Fe/M mole. The results showed that the best removal of treatment of copper containing wastewater by Ferrite Process achieved when the ratio of Fe/M mole was at 10. Treatment of PCB industrial real wastewater by Fenton-Ferrite Process and UV/H2O2-Ferrite Process which combined with Fenton, UV/H2O2 and Ferrite Process. The supernatant liquid containing organic compounds and heavy metal both could meet the standards of discharge wastewater and the sludge was judged with general(non-hazardous) wastes. The characteristic of the sludge were the diameter lattice less 100 nm and with magnetism and to develop recovery and utilization in a further work.
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The Study in Degradation of Ammonia with MnO2 as Catalyst for WaterChen, Chi-Ting 25 July 2003 (has links)
Nitrogen oxide in water was a critical factor of eutrophication. The poor tap-water quality in Taiwan was the result of ammonia nitrogen pollution. This research used manganese dioxide as the catalyst to degrade ammonia nitrogen content in water. Controlled factors in our experiment include basic test, optimal reaction condition test, and kinetics. Real water sample was drawn from the Love River for catalysis effect test. Results were then compared with the popularly used titanium dioxide.
Significant findings in this research include: 1) when the manganese dioxide content in water was 2%, the ammonia nitrogen removal rates were 31.80% under UV irradiation, and 22.21 % without light interference; 2) under UV irradiation, manganese dioxide would not affect the catalysis effect due to pH changes; 3) silicate in the water had catalysis effect, while sulfate, phosphate, and nitrate had inhibition effect; 4) manganese dioxide had catalysis effect in seawater, yet the removal rate would decrease as the salt content increases; 5) the rise of water temperature would enhance the ammonia nitrogen removal rate; 6) manganese dioxide had catalysis effect on the treatment of the Love River water, and the ammonia nitrogen removal rate reached 89.50 %; 7) in the biological test, manganese dioxide could effectively degrade the ammonia nitrogen content in water, and improve the survival rate of larval shrimp; 8) comparing to titanium dioxide, manganese dioxide had advantages of low cost, with catalysis effect in both seawater and fresh water under no light condition. As a result, manganese dioxide has significant future application potentials.
In the future, this research will conduct in-depth study on kinetics of degradability of manganese dioxide catalysis on ammonia nitrogen, and to design suitable catalytic reactor for water treatment. Moreover, it is of value to broadly research manganese dioxide related catalytic products, such as catalytic spray, catalytic paint, fluorescent tube, air filter, and catalytic fan...etc.
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Removal of Ethylenediaminetetraacetic Acid by O3 ¢ÎUV ProcessesLin, Yung-Ghang 12 August 2003 (has links)
This study was to investigate the removal efficiency and the feasibility of containing-EDTA solutions by O3 and O3/UV, advanced oxidation processes (denoted by AOPs). The operation parameters conducted in semi-batch reactor were as follows: ozone dose, pH, temperature and initial concentration of EDTA.
The best mineralization and COD removal was found at pH= 9 when the pH values in O3 process was controlled at 3, 5, 7, 9 and 11. Addition of UV in O3 process for treating solutions containing EDTA was found not increasing the reaction rate but raising the COD and mineralization efficiency.
In O3 process, the reaction rate was proportional to the ozone dose, it caused a higher mineralization. The higher the initial concentration of EDTA, the lower reaction rate, and the decreasing the mineralization was. Changing the temperature in reaction process was not obviously affected the removal of EDTA due to the lower activated energy found in O3 process.
In O3/UV process, EDTA was decomposed very fast, but it still could not be mineralized the intermediates completely. The concentration of nitrate formed in this process was low. It is probably for high energy NH-containing bonds which is not easy break down by O3/UV. Thus, the major reactions in this process are the break of C-N bond, and followed by the break of C-H bond.
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