Amid the COVID-19 pandemic, there has been an increase in the number of abuse cases, with bruising being the most common indicator. Often when a victim comes forward to report an assault, only slight redness may be observed, which may not accurately represent the injury severity. This study focuses on the use of Alternate Light Source (ALS) to detect and document such injuries more effectively. Following institutional approval, blunt trauma was inflicted on fifty-five healthy participants with no known medical conditions. The participant was seated while a spherical object weighing 465 grams was dropped at a height of 1.5 meters through a vertical tube onto the ventral/anterior surface of the participant’s forearm. The injury site was observed under four different lighting conditions. Findings were documented with photography over specific time intervals over 21 days. A comparison was made between body composition and skin tone on their effect on the visibility of the bruise. Our findings concluded that bruising in females persisted for a longer period, and the optimal wavelength for documentation of bruises is 415 nanometers with a yellow filter. A blinded study was conducted using the same methodology to assess the accuracy of ALS for detection of bruises. The blinded study results showed an accuracy of 75%. Although the results showed high accuracy, it was determined that the results rely on the researcher’s perception of bruising. Therefore, the results of the blinded study were inconclusive. Subsequently, peer review of the photographs was conducted to evaluate the effect of bias in detection of bruises. Similar to the results from the blinded study, the observation of the bruise remains highly subjective. The representative sample size was insufficient to provide statistical analysis between the observations of each reviewer. Therefore, the results from the peer review study were also inconclusive. Although ALS is effective in the documentation of bruises, caution is advised when using ALS to detect bruises as skin pigments, and pre-existing skin conditions may interfere with the interpretation.

The production of an isotropic source or detector by fixing a small resin sphere onto one end of an optical fibre is discussed. The potential application of these fibres to Photochemotherapy is reviewed. Isotropic fibres are used as both sources and detectors in experiments designed to measure the amount of light loss in a 1% solution of Neutralipid (an intravenous nutrient supply). Determination of light loss in this solution is important in one application of Photochemotherapy where an estimate of the irradiation time is required. / Thesis / Master of Science (MSc)

We aim to develop an implantable, optical neural imaging device by fabricating lasers and photodiodes onto a gallium arsenide substrate. Some studies suggest that lasers exhibit higher noise than light emitting diodes (LEDs) due to coherence effects – my studies aim to quantify this noise and to guide device development. To this end, I developed a model of a fluorescent imaging device which agreed with experiment. Noise analysis performed in phantom showed that laser sources exhibit temporal and spatial noise up to 10x higher than LED sources, and in vivo noise analysis also demonstrated this trend. I studied a neural injury model called cortical spreading depression in vitro in mouse brain slices and in vivo in the rat brain using laser and LED sources. Signal magnitudes in vitro are on the order of 10% and in vivo results are inconclusive. Future work will aim to reduce coherence related noise.

We aim to develop an implantable, optical neural imaging device by fabricating lasers and photodiodes onto a gallium arsenide substrate. Some studies suggest that lasers exhibit higher noise than light emitting diodes (LEDs) due to coherence effects – my studies aim to quantify this noise and to guide device development. To this end, I developed a model of a fluorescent imaging device which agreed with experiment. Noise analysis performed in phantom showed that laser sources exhibit temporal and spatial noise up to 10x higher than LED sources, and in vivo noise analysis also demonstrated this trend. I studied a neural injury model called cortical spreading depression in vitro in mouse brain slices and in vivo in the rat brain using laser and LED sources. Signal magnitudes in vitro are on the order of 10% and in vivo results are inconclusive. Future work will aim to reduce coherence related noise.

Syftet med undersökningen är ta reda på vilken förståelse elever från årskurs 5 har för ljuskällans tekniska utveckling. Syftet har uppnåtts med hjälp av frågeställningarna Vilken kunskap visar elever i årskurs 5 om ljuskällans tekniska utveckling? och Vilken kunskap visar elever i årskurs 5 om glöd- och lågenergiglödlampan som komponent i ett tekniskt system? Metoden som valts är kvalitativa intervjuer och innefattar totalt tio olika djupgående intervjuer. Under intervjuerna har eleverna fått placera fem olika ljuskällor i historisk ordning, med hjälp av dessa bilder har de fått beskriva den tekniska utvecklingen för att tillslut hamna på elsystemet. Resultatet visar att eleverna har mycket god kunskap om ljuskällans tekniska utveckling och god kunskap om systemet bakom glöd- och lågenergiglödlampan. Vid ljuskällans tekniska utveckling kan eleverna nämna material- och användningsskillnader samt skillnaden i hur de lyser. När det gäller elsystemet kan de nämna elsystemets delkomponenter, elens ursprungskällor samt hur energin färdas i systemet. Undersökningen visar att eleverna har en likartad förståelse jämfört med tidigare liknande forskning inom ämnet teknik, förståelse som också kan relateras till tidigare erfarenheter och ålder.

Based on a previously completed design for a soft X-ray (50-1100 eV) emission spectrometer, an endstation was constructed for the Resonant Elastic and Inelastic X-ray Scattering (REIXS) beamline at the CLS. The optical design employed techniques and software tools developed in-house using ray-tracing and diffraction grating efficiency calculations to analyze and compare existing designs and to propose a new design with superior performance. This design employs Rowland circle geometry to achieve a theoretical resolving power in excess of 2,500 in our range of interest. In addition, a novel optical design for a larger extremely high resolution spectrometer has been completed to provide theoretical resolving powers exceeding 10,000 throughout the higher end of the spectrum. To accommodate this optical design a completely new mechanical design was required, involving significant mechanical, electrical, vacuum and software engineering. Countless custom fabricated parts were required along with numerous o -the-shelf secondary instruments and systems. All told, this entirely student-managed project has cost over $1.5M and taken over 5 years. Construction is finally complete and the endstation is currently being commissioned. Necessary design changes made during the mechanical design process resulting in the selection of a more suitable, but lower resolution, detector. This reduced the theoretical maximum resolving power to 1,800 for the first order gratings and roughly 5,000 for the third order gratings. Commissioning is still underway, but first order resolutions in the range of 1,000 - 2,000 have been recorded as have third order resolutions exceeding 4,000. Publication quality data has been collecting by members of this research group and invited external users have successfully grown and measured samples here. Two of the optical elements required rework and upon their delivery the system commissioning will be completed and peer-reviewed access will begin.

The diploma thesis is focused on calculating the thermal resistance of the line light source and the design of the cooling system with ideal inlet temperature. The partial aim of the work is in cooperation with CAMEA spol. s r. o. to determine the thermal resistances of the individual parts of the device and propose modifications so that the total thermal resistance and the maximum temperature are within the limits given by the cooperating firm. The main objective is to design a cooling system with all safety features and recommended regulation for economical and reliable operation. Analytical calculations, CFD simulations and real-world testing are used to determine the desired results. A reduction by 30% in thermal resistance of the printed circuit board was achieved, the thermal resistance of the aluminum profile with the cooling channel was determined and its hydraulic properties were calculated. The current cooling system designed by CAMEA spol. s r. o. for less powerful diodes was verified for use in a more powerful system, and a new cooling system was designed for efficient and economical operation in a powerful diode system.

This thesis discusses modern methods for fast defect detection of solar cells. For the means of the defect classification, the technological production process of crystalline silicon solar cells is described. The defects are researched by the electroluminescence and prohtoluminescence methods. The Photoluminiscence method is improved by the posibility of using different wavelenght of excitacion sources. The range of using in industrial production is determined for the discussed methods.

This magister’s thesis is about modern lighting of vehicles, the visual range and afterglow in poor visibility. The first part of the thesis provides a detailed analysis of the current situation and problems, including a comprehensive description of the sources of light radiation, lamps, structures, and describe the systems used in modern lighting technology of vehicles. In the second part of the thesis there are the scientific methods to determine the issue of visual range and afterglow of the headlights. The second part is about the application of acquired techniques to detect an afterglow and the visual range of vehicles with modern headlights with a light source with xenon lamp, compared with a vehicle with a halogen lamp and a vehicle with an older halogen headlight.

The aim of the thesis is to introduce the basic photometric quantities and operating parameters of LED light sources, according to which the light sources are evaluated and compared. The thesis examines effects of high temperature and elevated stress on LED retrofits and a design of measurement methods to measure these influences. According to the proposed methods, nine samples of light sources were measured and compared to each other on a basis of the measurements. Comparison was made from the point of view of the energy as well as the quality of the produced light. The results were also compared to the parameters specified by the producers.