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Uppsatsen behandlar belysningsarmaturer inom LED-segmentet. Uppsatsen behandlar isynnerhet varför ljuskällan i LED-belysningsarmaturer oftast konstrueras så att ljuskällorna inteär utbytbara.Metoder som har använts i förstudien har varit; informationssökning, kvalitativa intervjuer,teknisk LED-modulsinventering samt konstruktionsundersökningar. Metoder som använts iproduktutvecklingsfasen har varit; tekniska informationsstudier, Idéinventering genom visuellidégenerering, imageboards och skissprocess (att tänka med en penna).Syftet med projektet har varit att utveckla en LED-armatur med utbytbar ljuskälla. Projektetsresultat blev en LED-golvarmatur med utbytbar ljuskälla. Ljuskällan som används i armaturenär enligt den unga branschfrivilliga standarden för LED-moduler, Zhaga. / The essay deals with luminaries in the LED segment. The essay deals in particular with why thelight sources in LED lighting fixtures usually is designed so that the light sources are notreplaceble.Methods used in this work has been; information searching, qualitative interviews, technicalLED module inventory and construction surveys. Methods used in the product developmentphase have been; technical information studies, Idea inventory by visual idea generation, imageboards and sketching process (thinking with a pen).The aim of the project was to develop an LED fixture with a replaceable light source. The resultof the project became an LED floor fixture with replaceable light source. The light source usedin the luminarie is of the young voluntary industry standard for LED modules, Zhaga.

Solar radiation influences virtually all biological process on earth. Yeasts, the microbial driver of ethanol fermentation, evolved on the surface of vegetation and had to adapt to survive photonic assault. Past research has demonstrated that white light affects yeast metabolism along with the ability to entrain circadian rhythms, although no known genetic mechanism accounts for this. High intensity narrow wavelength light-emitting diodes were employed to illuminate synthetic cultures under fermentation. Multiple colors along the visible spectrum were used, corresponding to the peak absorbance wavelengths of Saccharomyces sp. yeast. Impacts in primary metabolite evolution were found, dependent on wavelength. Longer wavelengths produced higher amounts of acetic acid and glycerol; shorter wavelengths produced more ethanol. Because past research showed light timing had pronounced effects, illumination schemes on the scale of milliseconds to hours were tested for ethanol production. Light schemes on the scale of enzymatic reactions, yeast generation times, and circadian rhythms produced the most ethanol. Discrete blocks and duration of illumination were used to elucidate where light had the most influence over yeast metabolism and fermentation. Late lag phase and mid log phase illumination impacted ethanol fermentation more than any other period of time. Light effects were tested on apple juice to see if they extended from synthetic media to natural products. Significant impacts on ethanol production were discovered and flavor/aroma impacts were noted. Light, color, intensity, and timing have all been shown to control and affect fermentation with both positive and negative effects established. / Doctor of Philosophy / Sun light influences virtually all biological process on earth. Yeasts, the microbial drivers of ethanol fermentation, evolved on the surface of vegetation and had to adapt to survive destructive effects of the sun. Past research has demonstrated that white light affects yeast metabolism along with the ability to develop growth cycles similar to day / night patterns, although it is currently not believed this possible due to the biology of yeast. High intensity single color light-emitting diodes were employed to illuminate laboratory formulated cultures under fermentation. Multiple colors along the visible spectrum were used, corresponding to the peak absorbance wavelengths of Saccharomyces sp. yeast. Green/yellow/red wavelengths produced higher amounts of acetic acid (vinegar) and glycerol; blue and ultraviolet wavelengths produced more ethanol. Because past research showed light timing could change how yeast grow and consumed carbohydrates, light timing on the scale of milliseconds to hours were tested for ethanol production. Light timing on the scale of milliseconds, hours, and daylight cycles produces the most ethanol. Discrete blocks and duration of illumination were used to find where during fermentation light had the most impact. It was found that from immediately after the beginning of fermentation to the middle of fermentation is where yeast responded the most strongly. Light effects were tested on apple juice to see if they extended laboratory cultures to natural products. Significant changes in the amount of ethanol produced were discovered and changes in the taste and smell of fermented apple juice were noted. Light, color, intensity, and timing have all been shown to control and affect fermentation with both positive and negative effects established.

As a growth industry, tremendous cost pressures are pushing the LED lighting market away from traditional power electronics converters and towards solutions that are more unconventional. Lower quality LED lights use simple low-cost converters, whereas high end product may add complexity in order to achieve a more dramatic energy savings. SIMO technology represents an opportunity in LED lighting to combine the low cost of single-stage converters with the energy saving capability of a two-stage, multiple string solution. This paper describes the modeling, analysis, design, and testing of a Multiple Independently Regulated Output Flyback (MIROF) converter, used in LED lighting for the purpose of multiple string control. This converter is based upon SIMO technology applied to a PFC Flyback converter. The result was the development of a novel control method and an operational demonstration unit. A cost comparison of the MIROF and a conventional two-stage driver shows a promising cost reduction benefit for the former, and comparative testing shows favorable performance of the MIROF converter compared to the two-stage approach. / Master of Science

Yes / Mothers' responsiveness to hunger and fullness cues has been implicated in the development of infant over-weight, and baby led weaning (BLW) is argued to be one way to protect against overfeeding. Whilst studies have examined maternal perceptions of hunger, fullness and adequate intake to some degree in traditional weaning (TW) contexts, less is known about this in BLW. This study therefore aimed to understand and compare maternal perceptions of cues and intake in BLW and TW. Eleven mothers of infants (7–24m) participated in semi-structured interviews based on discussions of short videos featuring participants feeding their infants. Interviews were read and transcribed in full. Data were selected for coding which addressed mothers' perceptions of infant hunger, fullness and sufficient consumption and subsequently subjected to template analysis. A sample of data was coded to produce an initial template which was applied to all interviews and revised in an iterative process to produce a final template for interpreting findings. Mothers in the study were adept at recognising fullness cues and gauging feeding state. Both groups perceived similar hunger cues although TW mothers reported a wider range of fullness cues. Both groups used numerous strategies for judging the adequacy of their babies’ intake. These included the use of infant cues, however perceived adequacy of intake was also influenced by factors such as infant tiredness and maternal worries about over and under-eating. Findings have implications for the development of responsive feeding interventions while also highlighting the utility of video elicited interviews for understanding feeding interactions. / This work was supported by a White Rose Doctoral Training Partnership Economic and Social Research Council PhD studentship (UK) to Janet McNally.

Silicon carbide was the first substance reported to display electroluminescence and enabled the first blue light emitting diode (LED). While the challenges of fabrication and poor efficiency lead to alternatives being developed, recent demand for high temperature, high power electronics have brought silicon carbide back to the forefront of development and improved quality and production scale. Due to the large bandgap, it is possible for light across the visible spectrum and into ultraviolet (UV) to be emitted. The wavelength of light produced depends heavily on the inclusion of different defects and impurities. Great care is taken to minimize this to improve device performance. The ability to induce and control these defects however, could allow for a range of wavelengths to be emitted and enable different colours of LEDs or the creation of white LEDs without the need for phosphors. This thesis explores different post fabrication treatments and operating conditions that can be used to alter the luminescent intensity and spectrum of commercial devices. Chapter one will include a brief history of LED development in addition to exploring the strengths and weaknesses of silicon carbide as a light emitting material. The following chapter will cover the theory behind LED operation and the structure/properties of SiC. In chapter 4, an electrochemical etch is used to alter the emission spectrum through the formation of a nano-porous surface layer. The processed device is then used to demonstrate electroluminescence due to lateral charge diffusion in SiC for the first time Chapter 5 details the effects of operating conditions on electroluminescence with a strong focus on temperature, and chapter 6 suggests future work and possible applications. / Thesis / Master of Science (MSc)

Participation in a combination of adult-led and peer-led activities appears to lead to favourable outcomes in sport (Côté, Erickson, & Abernethy, 2013). However, very little is known regarding the potential differences in how youth experience these distinct activities. Thus, the purpose of this project was to investigate the subjective and objective experiences of the same individuals across adult-led and peer-led sport activities. Recreational male soccer players (n = 27; Mean Age = 10.11) were examined using direct observation and experience rating scales in an effort to shed light on the impact that adult-led and peer-led sport activities have on the same athletes. The results clearly illustrated that the experiences of youth across these two activities are very different. In the adult-led activities, youth experienced high levels of effort and concentration, and spent more time being physically or mentally engaged. However, antisocial behaviours were also more frequent in the adult-led activities. Meanwhile, youth experienced high rates of prosocial behaviours, sport-related communication, as well as general communication during the peer-led activities. These findings suggest that rather than one approach being comparatively superior to the other, both adult-led and peer-led sport activities have the potential to yield unique benefits towards children’s experiences in sport. The results from the present study may have important practical implications if sport programs can utilize the benefits of both adult-led and peer-led activities to offer youth a sport experience which combines the best of both worlds. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2013-08-22 17:29:14.363

LED is one of the competitive businesses in the optical industry of Taiwan. Taiwan also has the most complete structure of LED industry from the chips (upstream) to the LED packages (downstream). Especial for the LED packages, from very beginning’s red, green, yellow and amber colors to blue and white colors, the LED companies in Taiwan have all participated more than 40 years and stand the very important role in the global LED industry. With the last 10 years, Due to the government in China also see the huge potential of LED business, so they invested the LED industry especial for the chips and packages started from the year 2000 as the important country development plan. However, with this 16 years’ over expansion in China, the global LED industry already became the cost driven industry for most of applications like lighting, TFT-LCD and consumer applications. How to find the next potential applications for LED package industry in Taiwan and have the difference than the companies in China will be the future growth opportunity of the LED business in Taiwan.

Les oxynitrures dopés terre rare présentent des propriétés intéressantes pour un usage en tant que luminophore pour LEDs blanches. Une nouvelle famille de luminophores dopés Eu2+ ou Ce3+ avec un réseau hôte oxynitrure de structure apatite a été étudiée : La8+xSr2-x(Si/Ge)6NyO26+x/2-3/2y. L’ammonolyse d’un précurseur oxyde de structure apatite a été utilisée comme technique générale de nitruration. Elle a permis de diminuer substantiellement la température de nitruration en comparaison avec la méthode classique par réaction à l’état solide sous atmosphère mixte N2/H2. Les différentes luminescences des luminophores obtenus ont été étudiées et corrélées à la structure cristalline à l’aide de différentes techniques de caractérisation.La structure apatite présente notamment la particularité de proposer plusieurs sites anioniques pour l’introduction de l’azote ainsi que deux sites cationiques pour les ions terre rare activateurs. L’utilisation de nombreuses techniques de caractérisation (IR, Raman, RMN, diffraction des neutrons) a permis d’obtenir des informations sur la position de l’azote. En parallèle, la comparaison des propriétés optiques avec celles de composés réduits sous Ar/H2 a permis d’attribuer les émissions aux différents sites cristallins disponibles dans la structure. Des mesures de rendement quantique ainsi que des tentatives d’optimisation des propriétés de luminescence ont été effectuées. / Rare-earth doped oxynitrides have attracted much attention as phosphors for white LEDs. A new family of Ce3+ or Eu2+-doped oxynitride phosphors with the apatite structure has been studied: La8+xSr2-x(Si/Ge)6NyO26+x/2-3/2y. The ammonolysis of an apatite oxide precursor has been used as a general method of synthesis, allowing decreasing the nitriding temperature respective to the classical solid state reaction in N2/H2 atmosphere. The luminescence properties of the obtained phosphors have been studied and relationships with the crystalline structure have been drawn.The apatite structure shows several crystallographic sites available for nitrogen as well as two cationic sites for optically active rare-earth ions. Several structural characterization technique have been used (IR, Raman, NMR, Neutron diffraction) and important information has been obtained concerning the nitrogen distribution in the available positions of the crystal structure. Comparison of the luminescent properties with those of compounds reduced under Ar/H2 allowed attributing emissions to the different crystallographic sites available in the structure.Quantum efficiency measurements have been carried out as well as trials for improving the intensity of the luminescent properties.

Nos últimos 15 anos a utilização do LED (Light-emitting diode) como fonte de iluminação alternativa se tornou bastante comum. Na década de 90 eles evoluíram de forma a ser possível a criação de LED com comprimentos de ondas menores, nas cores azul, verde e ciano e de onde veio a criação do LED branco de alta potência. Com este novo conceito de iluminação, devido às exigências de condições específicas para o desenvolvimento de atividades que exige um grau maior de cuidado no conforto visual e na confiabilidade de análise de cores na produção de produtos, o ser humano passou a ser um dos focos de pesquisa. Como a visão humana pode perceber o espectro de cores dos resultados de processos químicos com a presença do LED? Como o uso dessa tecnologia pode alterar de forma significativa o resultado de testes e exames onde a percepção de cores é determinante? O objetivo deste trabalho é identificar a sensibilidade ao contraste espacial e fazer uma comparação com o uso das lâmpadas fluorescentes tradicionais para identificar as principais vantagens e desvantagens no uso desta tecnologia. As lâmpadas LED foram instaladas em um dos laboratórios de Química do Câmpus São Paulo e testes para identificação de cores foram aplicados a voluntários. Para efeito de comparação, os mesmos testes foram aplicados no laboratório de Biologia que tem o mesmo formato e dimensão, mas as lâmpadas foram as Fluorescentes tubulares e, para completar a análise, painéis LED foram instalados, também, no laboratório de Química e os testes foram repetidos. Os resultados quanto ao uso das lâmpadas tubulares LED foram bem consistentes e, comprovam que o LED pode ser utilizado em ambientes profissionais onde as cores são imprescindíveis para qualidade de produtos. / In the last 15 years, the use of LED (Light-emitting diode) as a source of alternative lighting has become quite common. In the 90 they evolved in such a way that it is possible to create LED with smaller wavelengths, in the colors Blue, green and cyan and the creation of the high power white LED. With this new lighting concept, due to the requirements of specific conditions for the development of activities that require a higher level of care in the visual comfort and reliability of color analysis in the production of products, the human being has become one of the focuses of research. As the human vision could perceive the color spectrum of the results of chemical processes with the presence of LED? As the use of this technology can change significantly the result of tests and exams where the perception is crucial? The aim of this study is to identify the spatial contrast sensitivity and make a comparison with the use of traditional fluorescent lamps to identify the main advantages and disadvantages in the use of this technology. LED lamps installed in a Campus chemistry Labs and tests for identification of colors applied to volunteers. For comparison, the same tests applied in the laboratory of Biology that has the same format and size, but the lamps were the tubular Fluorescent and, to complete the analysis, LED panels installed, too, in the laboratory of chemistry and the tests repeated. The results regarding the use of LED lamps were quite consistent and show that the LED used in professional environments where the colors are indispensable for quality products.