This research plans the power capacities of the obstacle lighting on the power transmission towers, which are located in the areas where the utility cannot reach. The obstacle lighting is formed by light emitting diodes (LEDs), which are powered mainly by solar cells and subordinately by rechargeable batteries. The solar cells charge the batteries during the sunny daytime with plenty sunlight. When the sunlight is insufficient and the obstacle lamp is turned on, batteries and solar cells supply the obstacle lighting simultaneously. The power capacities of the solar cells and batteries are designated to keep the obstacle lighting system uninterruptible either under the drastic weather variation or a long period of insufficient sunlight. Under the specified operation rules of the obstacle lighting, a more economical and precise method is proposed for planning the power capacities of solar cells and batteries based on the weather data from Central Weather Bureau in recent 6 years following. The power planning method is implemented in the areas of Kaohsiung, Chiayi and Ali mountain to demonstrate the feasibility and the accuracy in reality.

ABSTRACT Organic light emitting diode (OLED) has significant scientific implication and technological potential. Using organic materials for tailored emitting color, threshold voltage reduction, and emission efficiency gain are the key points for the commercialization of OLED. An UV-Vis spectrophotometer was applied to obtain the absorption spectra of PVK, C6, and PRL, as well as their respective band gap (Eg) values of 3.49 eV, 2.32 eV, and 2.55 eV. The turn-on oxidation potential of cyclic voltammograms was reduced for HOMO energy at 5.64 eV, 5.21 eV, and 5.16 eV, respectively. The Eg subtracted from HOMO energy yielded the respective LUMO values of 2.15 eV, 2.89 eV and 2.61 eV. Excitation at 457 nm or 325 nm was applied to the freestanding films of PVK, PVK doped with C6 (10/1), and PVK doped with PRL (10/1). From the UV-Vis absorption spectra and Egs, we knew that 457 nm excitation did not generate photoluminescence (PL) of PVK. The PL spectra of the doped freestanding films were mostly attributed to the dye molecules of C6 or PRL. The PL spectra of doped freestanding films were insensitive to the excitation sources at 325 nm and 457 nm. There was a blue shift at the PL emission peak indicative of energy transfer from PVK to C6 or PRL for the doped films. Using spin-coating or vacuum deposition to fabricate PVK, C6, and PRL films onto an ITO substrate followed by evaporating Al (Ag) as the electron injector to form OLED devices. Because of the energy transfer between PVK and C6 or PRL, ITO/PVK:C6/Al homojunction OLED showed a smaller threshold voltage than that of ITO/C6/Al, from 9 V to 3.5 V. Likewise, ITO/PVK:PRL/Al homojunction OLED had a smaller threshold voltage than that of ITO/PRL/Al, from 8 V to 4.5 V. PVK was also used as the hole blocking layer to construct heterojunction OLED to balance electron-hole numbers in the emitting layer. The threshold voltage of ITO/C6/Al reduced from 9 V to 7 V with a heterojunction of ITO/PVK/C6/Al. A device of ITO/PRL/Al having a threshold voltage of 8V reduced to 6V with an ITO/PVK/PRL/Al heterojunction OLED. Coating a protective layer (Ag) on the metallic electron injector, or packaging the device in N2 could both decrease the decay and increase the life time of OLED.

LGP( Light Guide Plate) is the important part of the BLM(Back Light Modulus). It makes the BLM high illuminance and uniformity with leading light direction. LED(Light Emitting Diode) is the light source of the BLM. In this study there are V-Cut of the micro-structure applying on the LGP to discuss and research with optical simulation software TracePro. A 2.5 inch BLM with LED is building to analysis. First, the beginning side of the LGP has been studied with V-Cut. The purpose is making the distribution angel larger and upgrading brightness. Then, with the V-Cut micro-structure on the out-light surface and optical sheets get the largest light availability ratio. Finally, the reflect surface divides to five parts with different pitches design. The results show the good benefit by more uniformly light distribution and illuminance.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: cartilage, tendon, light scattering. Includes bibliographical references (p. 60-61).

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Graham, Samuel; Committee Member: Joshi, Yogendra; Committee Member: Kumar, Satish. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Light pollution in urban areas - How to prevent light pollution at construction   Jakob Sjöling   Light pollution is a relatively new but rapidly growing form of pollution. Society's increasing demand for light coupled with the pace at which lighting technology evolves is accelerating that growth. The purpose of this study was to analyse how the construction industry plan and design outdoor lighting when erecting new buildings, specifically with regards to the issue of light pollution. It also investigated how local authorities work with these issues during urban planning. In both cases special interest was placed in ways to improve the planning and use of outdoor lighting in order to minimize light pollution. To this end a series of interviews were held with people in the construction industry who are involved in the planning of lighting. Interviews were also held with local officials who manages issues of lighting and the environment within the municipality of Kungsbacka, Sweden. The interviews showed that people who work with these issues were well aware that poorly planned lighting can cause glare and disturbances. They were, however, almost totally unaware of the severe danger that light at night poses to both human health and environmental stability. To remedy this, information about the risks posed by night-time lighting must be spread from the scientific community to entrepreneurs and local officials who work with lighting. There are also several areas where changes in routines can help to avoid many of the potential pitfalls threatening to cause an, otherwise good, lighting plan to fail in regards to light pollution.

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Properties of coherent media in the regime of electromagnetically induced transparency (EIT) are studied. A study of the shape and width of the EIT resonance is presented for coherent media with buffer gas. Observation of an absorption-like resonance for large one-photon detunings in a medium with buffer gas and its properties are shown. The regime of ``slow'' and ``fast'' group velocities are studied. Observation of narrow resonances with a phase broadened probe field is presented, and possible application of this regime are outlined.

White LEDs (Light Emitting Diodes) in Visible Light Communication (VLC) is an emerging technology that is being researched so it can eventually be used for common communications systems. LEDs have a number of advantages, one of which is long life expectancy. However, like many emerging technologies, VLC has many technical issues that need to be addressed. We proposed an optical indoor wireless communication system that used white LEDs like plug-in devices. We developed a practical implementation of VLC and demonstrated it experimentally. In particular we focused on designing a prototype of VLC that can be used without having to make major changes to the present infrastructure with two types of protocol — namely RS-232 and USB — for data transmission.

The aim of this study was to test the hypothesis that ryegrass and clover, when grown under optimal conditions in mixed stands, interact in response to available light energy. with other resources non-limiting, pasture yield is determined by the efficiency with which solar radiation is intercepted by canopies and converted into dry matter. The clover-ryegrass interaction under varying light regimes, as experienced in the canopies of these pastures, was studied by investigating the growth and production of ryegrass and clover in relation to light harvesting abilities and photosynthetic utilization of intercepted light. Pasture canopy structure and growth were studied under a four-weekly clipping treatment. The interception of photon flux density (PFD) in the pasture canopy was monitored diurnally and seasonally in mixed and mono cultures. Light use efficiency (C02 fixed/ unit absorbed PFD) as well as photochemical efficiency of photosystem II (Fv/Fm) were studied by monitoring CO2 assimilation rates and chlorophyll fluorescence respectively. The results obtained from this study indicated that interaction did occur between ryegrass and clover, cultivated in mixed pastures. The mixture was capable of more efficient light interception than the mono cultures, which resulted in higher productivity. Light interception abilities, as manifested in canopy architecture, and not physiological utilization of light energy, were found to govern the interaction between the two pasture components. / Thesis (M.Sc.)-University of Natal, Durban, 1993.