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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

The effect of light-emitting diode light on the growth, egg production, egg quality, hormone concentration and health of Hy-Line® W-36 laying hens

Poudel, Ishab 25 November 2020 (has links)
Light-emitting diode (LED) is an improved light delivery technology that provides better energy efficiency, longer lifespan, and the ability to select a specific wavelength of light. We evaluated the effect of blue and red-LED on performance, behavior, egg quality, hormonal concentration, and prevalence of Avian pathogenic E. coli (APEC) like E. coli in pullets and laying hens raised in cageree housing system. Results showed that birds raised in blue-LED during the pullet phase had higher body weight and earlier onset of early lay. Red-LED increased the yolk percentage, illustrating that red-LED can stimulate reproduction. Red-LED also decreased the relative spleen percentage, which is an indication of decreased immunity. Overall egg production was not affected by the light treatment. Irrespective of the light treatment, a higher prevalence of APEC like E. coli was found in colonies isolated from the trachea suggesting a possible route of transmission in cageree housing system.
42

Quantifying the Carbon Reduction Impact of a University LED Lighting Retrofit Program

Kaip, Rory James 25 April 2017 (has links)
No description available.
43

LED-Konvertering : ICEBREAKER FREJ

Karlsson, Johannes January 2016 (has links)
Sjöfartsverket har fem egna isbrytare, Ale, Atle, Frej, Oden och Ymer. Atleklassen består av fem stycken isbrytare, var av tre finns i Sverige (Frej, Atle och Ymer). Atle byggdes på det finska varvet Wärtsilä 1974 och var den första serien och fick ge namn åt den nya isbrytarklassen som byggdes 1970-talet. Genom modernisering och förebyggande underhåll är förutsättningarna goda för att Atleklassen ska kunna fortsätta att tjänstgöra som isbrytare i ytterligare 15-20 år. Arbetet handlade om att ta fram ett underlag för en framtida LED-konvertering med hänsyn till energibesparing, miljöpåverkan, underhåll, ljuskvalitet och belysningspunkter.  LED-konverteringen inriktar sig till de allmänna utrymmena med lysrör. Syftet var att på uppdrag av Magnus Byström, Chief Electrical Engineer, arbeta fram ett underlag till en eventuell framtida konvertering av befintliga ljuskällor till LED på isbrytaren Frej. De befintliga lysrören är av typ T8-lysrör och jämfördes med utbytbara T8-LED-lysrör. Resultatet av arbetet var att en framtida LED-konvertering skulle göra stora besparingar både på miljön och energianvändandet. Det finns totalt 472st lysrör med effekten 18W och 503st med 36W. En framtida LED-konvertering skulle bidra till en ekonomisk besparing på (511 099 SEK) under LED-lysrörets livslängd. Den längre livslängden hos LED-lysrör kontra traditionella lysrör medför också att tidsåtgången för att byta ut trasiga rör minskar till 28 %.
44

Geração e detecção de luz subpoissoninana

Paulo Gonçalves de Oliveira, José January 2003 (has links)
Made available in DSpace on 2014-06-12T17:40:33Z (GMT). No. of bitstreams: 2 arquivo7024_1.pdf: 4034997 bytes, checksum: ad4a1eb119a0628485cbb768800161c9 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2003 / As propriedades estatísticas da luz despertam o interesse do mundo científico desde o início do século passado quando os cientistas da época estavam surpresos com o fato de que a luz podia ser interpretada como partícula em vez de onda. A investigação das propriedades estatísticas da luz ajudaria a esclarecer a questão sobre a natureza da radiação eletromagnética. Em trabalho publicado em 1909 por Albert Einstein as flutuações da radiação do corpo negro foram descritas em função de duas componentes: ondas e partículas clássicas. Com o início da teoria quântica foi possível analisar os tipos de luz prevendo a existência de fenômenos não explicados classicamente. Um dos casos é objeto do nosso trabalho: a existência de radiação óptica com flutuações menores que aquela apresentada por uma fonte com estatística Poissoniana. Essa característica é prevista apenas pelo uso da teoria quântica para descrever o fenômeno da detecção óptica. Este tipo de luz tem aplicações que vão de espectroscopia a comunicações ópticas. Os trabalhos desenvolvidos tiveram como objetivo analisar propriedades estatísticas da luz, a construção de um aparato capaz de gerar e de detectar luz com variância menor que sua média (luz subpoissoniana), além de analisar as correlações existentes em dois feixes de luz em um interferômetro. Além dos trabalhos experimentais uma vasta bibliografia relacionada à pesquisa de óptica quântica e detecção da luz foi reunida, obtendo-se uma sólida fonte de consulta
45

Armaturfamilj med LED som ljuskälla

Smedberg, Hanna January 2009 (has links)
This report describes a project, which was carried out as a final thesis covering 30 ECTS during the final semester of the Master of Science programme Industrial Design. The assignment was issued by Fagerhults Belysning AB in Habo. The assignment was to design a family of products in which LED was to be used as a source of light.   The main focus in the initial part of the project was to find a way to design the inside of armature which was suitable for LED technology. An armature, already in the range of products at Fagerhult, with the desired qualities that was to be strived after was the Zintra. The lighting source of the Zintra is a compact fluorescent lamp. With its opal anti-glare barrier the Zintra gives a soft and pleasant light in many directions.   The family of products is intended for the public environments. The design was supposed to be suitable for many different places. The products should be decorative, both while switched on and switched off, impactful alone or in groups. The challenge in this project was to find an efficient way to direct the light from the LEDs out of the armature. The problem was that the LEDs emits aimed light while most other light sources, among them the compact fluorescent lamp, emits light in all directions. A big part of the project was experimenting with the LEDs to achieve a good light from the armatures. A good armature is anti-glaring, has sufficient illumination power and aims the light correctly. To avoid spots of light or shadows forming on the opal anti-glare barrier was an important goal with the experiments.   The result of the work is a suggestion of an outer, esthetic form of the armature as well as a suggestion for a technical solution to use LEDs. The development of the pendant armature received the most attention, being the most difficult armature to design with LEDs. The reasoning was that if the pendant armature would work with LED, so would the less complicated wall and ceiling armatures.
46

Integrering av belysning i ytterdörr

Johansson, Kalle, Larsson, Alexander January 2012 (has links)
No description available.
47

YAG:Ce3+ phosphors doping research, and application of surface modification

Huang, Yu-shyang 22 June 2011 (has links)
With today's technology, a variety of styles and a variety of different LED material was produced. The development of LED in the same time, the vendor industry in order to defend their own interests and under the huge business opportunities, and each side of the application of the style-related intellectual property rights in the LED,although the wise limits of property rights, but also contributed to a more diverse The LED manufacturing methods have been developed. Our experiment is the YAG:Ce3+ doped other compounds (for example: copper,aluminum, ...) in a small test tube and in within the near vacuum of a state to do the open end of the seal, and then make a small test tube temperature heating, hopes the doping elements in the impact of high temperatures contributed to YAG:Ce3+ to adjust the lasing wavelength, and in vitro experiments also found with the increase of heating temperature photoluminescence intensity for a gradual downward trend. The YAG:Ce3+ yellow phosphor surface facing the shortcomings of a defect, so we research for YAG:Ce3+ phosphors adsorbed on the surface of anti-reflective film to be improved and modified YAG:Ce3+ has a surface defect observation showed that after modification surface defects of the YAG:Ce3+ emission intensity on increase in the phenomenon. We will also anti-reflective film adsorbed on the YAG:Ce3+ compounds used in fluorescent plastic surface on top, and with the original YAG:Ce3+ phosphors are made of rubber making to compare, comparison of the fluorescent plastic found on YAG:Ce3+ surface adsorption anti-reflective film for luminescence efficiency and the absorption rate for the blue light has a better performance.
48

The Study of Future Growth Value in LED - The Case of Epistar

Chen, Yi-ho 15 July 2011 (has links)
This study mainly used O `Byrne (2000)'s theoretical basis, which is the company's economic value added is divided into two parts, Current operating value and future growth value , Use LED industry Epistar as the object of study, with factors which are the growth rate of net operating profit after-tax , competitive rates, long-term equity , and growth rate of enterprise investment in the company's future growth rate and the value of relationships, the study found out the stock market has significant influences for Taiwan's LED industry, the value of the company's future growth closely related. There are two results for the research towards the relationship between innovative products and future growth value , as follow: (1) Companies with innovative products ,share better performance on growth rate of net operating profit after-tax, competitive rates, long-term equity ,then those who do not. (2) Epistar put its innovative products into the market in 2009 and come out that both growth rate of net operating profit after-tax and competitive rates grow significantly.
49

A Simple Package Technique of Light Emitting Diode for Enhancing Illuminant Quality

Lin, Yu-Chung 20 June 2008 (has links)
The purpose of this thesis is to fabricate an LED module with low half intensity angle(HIA) ,and to use this module to form a line source with optical performance comparable to that of a CCFL .In addition ,heat dissipation of the LED module on different sub-mounts is also investigated . The LED modules were formed by first etching a through si via on silicon substrate using wet etching technology for light confining .Then a thin layer of metal was deposited on to the via to reflect the lights emitted from the LED .The LED die was attached to the Si sub-mount with electrodes ,and the connections between the LED and the Si sub-mount were completed by wire bonding .Finally ,the LED modules were obtained by positioning the Si substrates onto the Si sub-mounts using UV epoxy . The optical performance of the LED module was simulated by Lighttools .For the si substrate with a thickness of 400 £gm ,a simulated HIA of 36 o was obtained .Using six-LED package ,a 3-cm line source with 84.8% output uniformity was simulated .On the other hand ,the measured HIA of a LED module ,and the uniformity of 3-cm line source are 38 o and 84.8% ,respectively. The thermal resistance of the si sub-mounts were also investigated .The different structures of the sub-mount were proposed ,namely ,LED to Copper case ,LED to Si sub-mount to Copper case ,and LED to Si sub-mount with Copper filled via to Copper case .The estimated thermal resistance of the sub-mounts are 13 W/mk¡B19.4 W/mk and 34.7 W/mk .We believe that the large thermal resistance of the Si sub-mount with Copper filled via is primarily caused by 800 £gm thick substrate .
50

Concentration Effect of Organic Phosphors Pumped by Blue LED

Chen, Hsin-Nan 25 July 2008 (has links)
In this thesis , we used organic phosphors 10-(2-benzothiazolyl) -1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H,11Hbenzo[l]-pyrano[6,7,8-ij]inolizin-11- one (C545T) and 10-(2-benzothiazolyl)- 1,3,3,7,7-pentametquhyl-2, 3, 6,7-tetrahydro-1H,5H,11H-benzo[l]-pyrano[6,7,8-ij]-quinolizin-11-one(C-545P) , by mixed method to package for LED. First , we used C545T and C545P with different concentration of Silicone ,to find the best mixed ratios. Organic C545T and C545P were proposed to be the candidate of the green phosphor. The emitting peaks of C545P and C545T were 496 nm and 500 nm measured by photoluminescence, respectively. Organic green phosphors were mixed with silicone with different concentration.The optimal mixed weight ratio of phosphor to silicone were 1:500 and 1:300 for C545P and C545T,respectively. Second, we used InGaN/GaN multi-quantum well(MQW) Blue chip toexcite Organic phosphors were mixed with silicone with different concentration to fabricated device. With an injected current 20 mA ,we obtained the luminous efficiency was 79 lm/W , CIE coordinate at (0.33, 0.60) of packaged device C545T @ 1:500 ,and then the luminous efficiency was 68 lm/W , CIE coordinate at (0.33, 0.60) of package device C545P @1:300.Compared with commercial InGaN green LED , we find mixed organic phosphors packaged devices of luminous flux and luminous efficiency and have improved. The best mixed at 1:500 packaged device of C545T and silicone, and luminous efficiency increase 1/3.

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