In this study, the characteristic properties of the ultrafast laser exhibit sufficiently in the application of RFOBIC and two-photon UV fluorescence. This laser can be used to measure photonic components with fast responding speed due to the ultrashort pulse and broad bandwidth which is RF bandwidths of greater than 1.8THz. we have demonstrated the use of a frequency-doubled femtosecond optical parametric oscillator in generating two-photon excitation that is equivalent to ultraviolet(UV) light with wavelength less than 300 nm. This capability allows observation of some amino acids and enables excitation that is only possible with wavelength in UVB range(290 nm-320 nm)

Bei der postmortalen Befunderhebung an Zähnen im Rahmen der Identifikation unbekannter Leichen besteht die Möglichkeit, dass zahnfarbene Füllungen übersehen oder fehlgedeutet werden. Daraus entstehende Diskrepanzen zu den antemortalen Daten können zu Problemen bei der Identifikation führen. Ziel der Ar-beit war daher die Ermittlung einer zuverlässigen und praxistauglichen Methode zum sicheren Erkennen von zahnfarbenen Zahnfüllungen bei der postmortalen Befunderhebung. Dazu wurden 50 menschliche Zähne mit zahnfarbenen Füllungen versorgt und mittels UV-Licht, digitaler IR-Fotografie, digitalem Röntgen, CT und einer Schmelzfärbemethode bezüglich der Erkennbarkeit der Füllungen untersucht. Die geeignetsten Methoden wurden zusätzlich anhand von Farbfotografien in Fragebögen beurteilt. Die Schmelzfärbemethode erwies sich als die genauste Methode, aber auch mit Hilfe der UV-Fluoreszenz konnten mit 97% nahezu alle Füllungen erkannt werden. Die Röntgendiagnostik ermöglichte das Erkennen von 80% der vorhandenen zahnfarbenen Füllungen. Das CT ist unzuverlässig und die Infrarot-Fotografie ist ungeeignet für diese Fragestellung. Im Ergebnis dieser Studie kann die verbesserte Schmelzfärbung als sicherste Me-thode zur postmortalen Identifikation von zahnfarbenen Füllungen empfohlen wer-den. Als zuverlässige und schnelle „Screening Methode“ ist die Untersuchung mittels UV-Fluoreszenz geeignet. Für den sicheren Einsatz der UV-Fluoreszenz in der Rechtsmedizin sollten die Fähigkeiten der Rechtsmediziner im Umgang mit dieser Methode anhand praktischer Übungen geschult werden.

abstract: Encapsulant is a key packaging component of photovoltaic (PV) modules, which protects the solar cell from physical, environmental and electrical damages. Ethylene-vinyl acetate (EVA) is one of the major encapsulant materials used in the PV industry. This work focuses on indoor accelerated ultraviolet (UV) stress testing and characterization to investigate the EVA discoloration and delamination in PV modules by using various non-destructive characterization techniques, including current-voltage (IV) measurements, UV fluorescence (UVf) and colorimetry measurements. Mini-modules with glass/EVA/cell/EVA/backsheet construction were fabricated in the laboratory with two types of EVA, UV-cut EVA (UVC) and UV-pass EVA (UVP). The accelerated UV testing was performed in a UV chamber equipped with UV lights at an ambient temperature of 50°C, little or no humidity and total UV dosage of 400 kWh/m2. The mini-modules were maintained at three different temperatures through UV light heating by placing different thickness of thermal insulation sheets over the backsheet. Also, prior to thermal insulation sheet placement, the backsheet and laminate edges were fully covered with aluminum tape to prevent oxygen diffusion into the module and hence the photobleaching reaction. The characterization results showed that mini-modules with UV-cut EVA suffered from discoloration while the modules with UV-pass EVA suffered from delamination. UVf imaging technique has the capability to identify the discoloration region in the UVC modules in the very early stage when the discoloration is not visible to the naked eyes, whereas Isc measurement is unable to measure the performance loss until the color becomes visibly darker. YI also provides the direct evidence of yellowing in the encapsulant. As expected, the extent of degradation due to discoloration increases with the increase in module temperature. The Isc loss is dictated by both the regions – discolored area at the center and non-discolored area at the cell edges, whereas the YI is only determined at the discolored region due to low probe area. This led to the limited correlation between Isc and YI in UVC modules. In case of UVP modules, UV radiation has caused an adverse impact on the interfacial adhesion between the EVA and solar cell, which was detected from UVf images and severe Isc loss. No change in YI confirms that the reason for Isc loss is not due to yellowing but the delamination. Further, the activation energy of encapsulant discoloration was estimated by using Arrhenius model on two types of data, %Isc drop and ΔYI. The Ea determined from the change in YI data for the EVA encapsulant discoloration reaction without the influence of oxygen and humidity is 0.61 eV. Based on the activation energy determined in this work and hourly weather data of any site, the degradation rate for the encaspulant browning mode can be estimated. / Dissertation/Thesis / Masters Thesis Chemical Engineering 2018

Le recyclage des matériaux issus de produits en fin de vie est un enjeu important pour préserver nos ressources de matières premières qui sont de plus en plus rares et dont l'extraction est de plus en plus impactante pour l'environnement. Pourtant certains matériaux sont peu recyclés. C'est le cas des polymères de couleur sombre.L'originalité de ce travail est d'avoir intégré dans le processus de conception deux stratégies de l'écoconception : les limites des procédés de tri actuel et les limites sur les ressources. Cette démarche a abouti à concevoir un matériau et son procédé de recyclage. Ce système apporte potentiellement un bonus écologique en permettant de produire plus de matières recyclées sur le marché en satisfaisant les consommateurs en apportant une traçabilité de ces matières et une technologie nouvelle validée par la mise au point d'un démonstrateur couplé à un convoyeur industriel. / The recycling of materials from end of life products is a important issue to preserve our resources of raw materials which are more and more rare and the extraction of which is more and more impactant for the environment. Nevertheless certain materials are little recycled. It is the case of dark colored polymers.The originality of this work is to have integrated into the process of design two strategies of ecodesign: the limits of current sorting processes and the limits on the resources. This approach succeeded to design a material and its process of recycling. This system brings potentially an environmental bonus by allowing producing more recycled materials on the market, satisfying the consumers by bringing a traceability of these materials and a new technology validated by the development of a demonstrator coupled with an industrial conveyor.

For a PV plant it is of fundamental importance that the operation of the PV modules is free from faults or at least that the faults can be detected early, to ensure efficient electricity production. Some defects such as cracks can be seen in visible light while microcracks and damage to the silicon material can only be seen through special lighting. This study focuses on the most common defects in photovoltaic (PV) systems. Compare the infrared (IR) technology with the new ultraviolet (UV) fluorescence image technique for PV characterization, based on their accuracy and uncertainty factors under an experimental field investigation. In this study, first a literature study was conducted to the most common defects in PV system and their impact on electricity generation. Then a simulation model of a PV system was created in PVsyst and exported to Microsoft Excel which was used to evaluate how different defects at different stages of the PV cell's life cycle impact electricity generation, performance parameters and economic exchange. Furthermore, experiments with UV and IR was implemented at a PV system located in Dalarna and some PV modules at MDH. It was conducted that occurrence of snail tracks, delamination and hot spots in combination with bypass failures and non-functioning cell will affect the economic profitability in the long run and the payback time will increase since their impacts on electricity generation and performance parameters are huge. The worst case is when PV modules are affected by the fault in bypass diode and non-functioning cell which result to a payback time longer than the module's lifetime and huge amount electricity losses in different bypass diodes configurations. Since UV and IR are two different methods that are performed in two different ways, different errors occurred during the measurements. The biggest external factor was the weather that determined if the experiment could be implemented. The IR method gave decent results and was quicker to use, but the UV method highlighted some defect which could not be seen with the IR technology.

Intrusion-related, carbonate rock–hosted replacement deposits are an important source of global base metal production that includes: Cu-Zn skarn, Zn-Pb-Ag carbonate replacement and Ag-base metal deposits. These deposits are located in multiple geological settings and are commonly associated with low-grade Cu-Mo calc-alkaline porphyry districts. Visible alteration halos to these deposits range from ten to hundreds of metres around high temperature skarn deposits, being small to imperceptible around the distal relatively low temperature members of this clan. Patterns of visible and cryptic alteration are described and constrained in this study particularly around paleo-fluid flow zones at different distances and elevations from the ore centre. This was done in order to identify the large-scale zonation, mechanisms, and effects of fluid infiltration especially into the distal portions of these deposits. The main alteration tracers employed included mineralogy, major and trace element geochemistry, oxygen and carbon isotopes, and the fluorescent signature of calcite veins associated with the fluids conduits. Two areas were selected for this study: the large Cu-Zn Antamina skarn and the Ag-base metal Uchucchacua vein deposits in the Peruvian Central Andes as these deposits represent the end-members of the polymetallic carbonate rock-hosted deposits and hence, provide an excellent opportunity to examine the margins and upper sections of these hydrothermal systems. Geochronological analyses of intrusive dikes were used to establish the magmatic and hydrothermal evolution associated with mineralization, as well as the genetic linkage between proximal and distal portions of the mineralizing system at Antamina. Oxygen, carbon and strontium isotope data of vein minerals is also used to constrain the temperature of the fluids proximal and distal to the magmatic centre. Chemical data of fluorescent and non-fluorescent veins were used to determine the main activators of fluorescence and to constrain its relationship with mineralizing fluids. In summary, results of this research identify a large-scale zonation of visible and cryptic alteration around paleo-fluid flow zones demonstrating the linkage between Ag-base metal veins, replacement and skarn deposits. Anomalous halos determined throughout Antamina and Uchucchacua deposits may contribute to the development of a more systematic exploration methodology for these types of deposits.

Intrusion-related, carbonate rock–hosted replacement deposits are an important source of global base metal production that includes: Cu-Zn skarn, Zn-Pb-Ag carbonate replacement and Ag-base metal deposits. These deposits are located in multiple geological settings and are commonly associated with low-grade Cu-Mo calc-alkaline porphyry districts. Visible alteration halos to these deposits range from ten to hundreds of metres around high temperature skarn deposits, being small to imperceptible around the distal relatively low temperature members of this clan. Patterns of visible and cryptic alteration are described and constrained in this study particularly around paleo-fluid flow zones at different distances and elevations from the ore centre. This was done in order to identify the large-scale zonation, mechanisms, and effects of fluid infiltration especially into the distal portions of these deposits. The main alteration tracers employed included mineralogy, major and trace element geochemistry, oxygen and carbon isotopes, and the fluorescent signature of calcite veins associated with the fluids conduits. Two areas were selected for this study: the large Cu-Zn Antamina skarn and the Ag-base metal Uchucchacua vein deposits in the Peruvian Central Andes as these deposits represent the end-members of the polymetallic carbonate rock-hosted deposits and hence, provide an excellent opportunity to examine the margins and upper sections of these hydrothermal systems. Geochronological analyses of intrusive dikes were used to establish the magmatic and hydrothermal evolution associated with mineralization, as well as the genetic linkage between proximal and distal portions of the mineralizing system at Antamina. Oxygen, carbon and strontium isotope data of vein minerals is also used to constrain the temperature of the fluids proximal and distal to the magmatic centre. Chemical data of fluorescent and non-fluorescent veins were used to determine the main activators of fluorescence and to constrain its relationship with mineralizing fluids. In summary, results of this research identify a large-scale zonation of visible and cryptic alteration around paleo-fluid flow zones demonstrating the linkage between Ag-base metal veins, replacement and skarn deposits. Anomalous halos determined throughout Antamina and Uchucchacua deposits may contribute to the development of a more systematic exploration methodology for these types of deposits.

Intrusion-related, carbonate rock–hosted replacement deposits are an important source of global base metal production that includes: Cu-Zn skarn, Zn-Pb-Ag carbonate replacement and Ag-base metal deposits. These deposits are located in multiple geological settings and are commonly associated with low-grade Cu-Mo calc-alkaline porphyry districts. Visible alteration halos to these deposits range from ten to hundreds of metres around high temperature skarn deposits, being small to imperceptible around the distal relatively low temperature members of this clan. Patterns of visible and cryptic alteration are described and constrained in this study particularly around paleo-fluid flow zones at different distances and elevations from the ore centre. This was done in order to identify the large-scale zonation, mechanisms, and effects of fluid infiltration especially into the distal portions of these deposits. The main alteration tracers employed included mineralogy, major and trace element geochemistry, oxygen and carbon isotopes, and the fluorescent signature of calcite veins associated with the fluids conduits. Two areas were selected for this study: the large Cu-Zn Antamina skarn and the Ag-base metal Uchucchacua vein deposits in the Peruvian Central Andes as these deposits represent the end-members of the polymetallic carbonate rock-hosted deposits and hence, provide an excellent opportunity to examine the margins and upper sections of these hydrothermal systems. Geochronological analyses of intrusive dikes were used to establish the magmatic and hydrothermal evolution associated with mineralization, as well as the genetic linkage between proximal and distal portions of the mineralizing system at Antamina. Oxygen, carbon and strontium isotope data of vein minerals is also used to constrain the temperature of the fluids proximal and distal to the magmatic centre. Chemical data of fluorescent and non-fluorescent veins were used to determine the main activators of fluorescence and to constrain its relationship with mineralizing fluids. In summary, results of this research identify a large-scale zonation of visible and cryptic alteration around paleo-fluid flow zones demonstrating the linkage between Ag-base metal veins, replacement and skarn deposits. Anomalous halos determined throughout Antamina and Uchucchacua deposits may contribute to the development of a more systematic exploration methodology for these types of deposits. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Bei der postmortalen Befunderhebung an Zähnen im Rahmen der Identifikation unbekannter Leichen besteht die Möglichkeit, dass zahnfarbene Füllungen übersehen oder fehlgedeutet werden. Daraus entstehende Diskrepanzen zu den antemortalen Daten können zu Problemen bei der Identifikation führen. Ziel der Ar-beit war daher die Ermittlung einer zuverlässigen und praxistauglichen Methode zum sicheren Erkennen von zahnfarbenen Zahnfüllungen bei der postmortalen Befunderhebung. Dazu wurden 50 menschliche Zähne mit zahnfarbenen Füllungen versorgt und mittels UV-Licht, digitaler IR-Fotografie, digitalem Röntgen, CT und einer Schmelzfärbemethode bezüglich der Erkennbarkeit der Füllungen untersucht. Die geeignetsten Methoden wurden zusätzlich anhand von Farbfotografien in Fragebögen beurteilt. Die Schmelzfärbemethode erwies sich als die genauste Methode, aber auch mit Hilfe der UV-Fluoreszenz konnten mit 97% nahezu alle Füllungen erkannt werden. Die Röntgendiagnostik ermöglichte das Erkennen von 80% der vorhandenen zahnfarbenen Füllungen. Das CT ist unzuverlässig und die Infrarot-Fotografie ist ungeeignet für diese Fragestellung. Im Ergebnis dieser Studie kann die verbesserte Schmelzfärbung als sicherste Me-thode zur postmortalen Identifikation von zahnfarbenen Füllungen empfohlen wer-den. Als zuverlässige und schnelle „Screening Methode“ ist die Untersuchung mittels UV-Fluoreszenz geeignet. Für den sicheren Einsatz der UV-Fluoreszenz in der Rechtsmedizin sollten die Fähigkeiten der Rechtsmediziner im Umgang mit dieser Methode anhand praktischer Übungen geschult werden.

Highly accurate analysis for the quantification of sulphur compounds and oxygenated volatile organic compounds are crucial for the adherence of the legislation in different environmental sectors. The sulphur compounds and oxygenated volatile organic compounds measurements are challenging, due to various factors such as molecules being adsorbed on the inner surfaces of cylinders. It is therefore important to produce accurate and reliable reference gas mixtures with mole fraction at ambient levels for the air quality monitoring and field of gas sensing in South Africa. The challenges in producing sulphur compounds and oxygenated volatile organic compounds reference gas mixtures are that the overall process from gravimetric preparation steps until the comparison analysis process and the stability of mixture in the gas cylinder, results in the large measurement uncertainties. In order to produce reference gas mixtures of the highest level, three important steps are followed: purity assessment of starting material, gravimetric preparation, and verification/validation of prepared gas mixtures. The purity analysis of high purity starting materials was determined using gas chromatography coupled with various detectors and Karl Fischer for determination of moisture content in high purity chemicals. The sulphur compounds and oxygenated volatile organic compounds to be developed in this study were hydrogen sulphide, sulphur dioxide, acetone, methanol, ethanol, isopropanol, and n-butanol. These components were produced following the International Organisation for Standardisation documents at mole fraction of 10 µmol/mol for sulphur compounds and 5 µmol/mol for oxygenated volatile organic compounds. The preparation of sulphur compounds reference gas mixtures was done with a static gravimetric method using a direct method where a target component was transferred directly into the cylinder. The preparation of oxygenated volatile organic compounds used an indirect method whereby a target liquid component from high purity chemicals was transferred into a cylinder using a gas-tight syringe.The comparison between the reference gas mixtures was validated using Non-Dispersive Ultra-Violet analysers (NDUV), gas chromatograph coupled with pulsed discharge helium ionisation detector (GC-PDHID, UV fluorescence analysers for sulphur compounds and gas chromatograph coupled with flame ionisation detector (GC-FID) for the oxygenated volatile organic compounds. A multi-point calibration method was used to analyse sulphur dioxide and hydrogen sulphide on the NDUV analyser, and the single-point calibration method was used for analysis on the gas chromatography and UV fluorescence where a sample mixture is analysed against a reference mixture with a similar mole fraction. The statistical data considered during analysis included calculation of the instrument drift and percentage relative standard deviation to check measurements repeatability, reliability, and measurement uncertainty. The gravimetric results of prepared sulphur compounds at 10 µmol/mol gave a percentage relative expanded uncertainty of 0.041 % REU for hydrogen sulphide, 0.12 % REU for sulphur dioxide. The gravimetric results of prepared oxygenated volatile organic compounds at 5 µmol/mol showed a percentage relative expanded uncertainty 0.068 to 0.35 % REU for isopropanol and ethanol respectively and less than 2.4 % REU for multi component of oxygenated volatile organic compounds. Finally, the primary standard gas mixtures of sulphur compounds and oxygenated volatile organic compounds were developed with the highest metrological measurement uncertainty level of (k=2). / Environmental Sciences / M. Sc. (Environmental Sciences)