KEYWORDS: Solid state lighting, Light sources and illumination, Lamps, Light emitting diodes, Safety, Solar cells, Renewable energy, Carbon dioxide, Solar energy, Medicine
Much has been written about the daily challenge for survival faced by countless millions of developing world families
and the overdeveloped world has offered a number of solutions by which those at the base of the economic pyramid
(BOP) can help themselves. Light Up The World (LUTW), the global leader in bringing Renewable Energy (RE) based
Solid State Lighting (SSL) to the developing world, offers yet another solution, and one that comes with a very high
probability of success. In this paper we discuss: the critical role played by micro credit (banking for the poor); a typical
example of a developing world community and their lighting needs and expenditures; how SSL can contribute positively
to all eight of the Millennium Development Goals; the micro and macroeconomics of SSL at the BOP, its numerous
societal benefits and its potential perverse outcomes; and thought there will always be a role for the donation based
model, it is only through the market model that safe, healthy and affordable SSL will reach the majority of the BOP,
such are the staggering numbers involved. LUTW's fundamental goal, through the facilitation of RE based SSL, is to
improve the quality of life of those, who through no fault of their own, find themselves trapped in a cycle of poverty.
Approximately two billion people, one third of humanity still has no access to electricity, and thus relies on fuel-based lighting, a dangerous alternative of last resort that is unhealthy, expensive, and offers very poor levels of illumination. This lack of light makes it difficult to perform most evening activities including studies by children and adults alike and therefore represents a significant barrier to human development. Over the past five years The Light Up The World Foundation (LUTW) has pioneered the use of the white light emitting diode (WLED) as an alternative home lighting solution, bringing clean, affordable light to thousands of non-electrified homes around the world. The information presented herein is intended to increase awareness of the enormous potential possessed by this emergent technology, "Solid State Lighting" (SSL), to improve the quality of life of millions of people around the world. The feasibility of its implementation is demonstrated with results from comprehensive field experience and laboratory research work. The mutual economic, social and environmental benefits for both stakeholders and SSL suppliers are discussed. Strategies conducive to the dissemination of this technology throughout the developing world are also presented.
Over the past 5 years, the application of white LEDs for ambient lighting has been investigated in the remote villages of Nepal. Currently, lighting is often met using kerosene wick lamps, which emit unhealthy levels of fumes, or by burning sap-filled pine sticks, which are worse than the kerosene lamps. A team of students from Calgary University developed some LED lamps that could easily be fabricated in Nepal using local materials and personnel. To generate power, a pedal DC generator was developed to charge batteries, as well as a simple wind turbine. The Nepal Light Project implemented a series of many projects over the last 2 years in several villages across Nepal, using several different power generating systems. A total of 142 households, two schools and a temple were fitted with lamps in 2000, and more will follow in 2001. A research project has also been undertaken in Nepal for the Danish International Development Agency (DANIDA) to investigate the potential for energy efficient lamps in the micro hydro industry. The R&D project was very small, and conducted basic testing on locally available compact fluorescent lamps and LED lamps. The report concluded that encouraging the use of CFLs would decrease costs by 30-50%, and that they should be included in the subsidy policy, along with power factor correcting capacitors. LED lamps should not be overly encouraged as the development of the diodes was advancing very rapidly. The real advantage of LED lamps lies in extremely low maintenance costs due to the low power requirements and long life, which is just as important for remote villages as it is for traffic lights and exit signs. It is estimated that these low ongoing costs could be as low as $3/household/year for a rural lighting project. Pilot projects should be encouraged to demonstrate and investigate the potential of WLEDs for lighting in remote communities in developing countries. With 2 billion people without access to electricity, and lighting being the first end use people generally require, the potential for white LEDs is nothing short of staggering, but they will face challenges similar to CFL technology due to the high initial cost of the lamps.
Collimated light transmission studies of bovine tendon have been carried out to show the collagen waveguide effect. A monochromator/lamp apparatus was used to irradiate tissue samples and the transmitted light intensity was measured parallel and perpendicular to the collagen fiber orientation. The intensity parallel to the collagen fibers was at least twice that seen with perpendicular propagation. This indicates there is less scattering parallel to the fibers and light waveguiding is present for photon scattering. Also, absorption of light due to hemoglobin around 550 nm and due to water at 980nm was more prominent for parallel than perpendicular propagation. The light may travel either through the collagen fibril or fiber bundles or through the interstitial matrix. Sequential tests during tissue dehydration were performed and it was found that the transmitted light intensity increased with dehydration. This suggest that light may not be traveling through the interstitial matrix where water is the major component. Water may be acting as a reflection boundary for the light that is passing through the fibril or fiber bundles. Collagen waveguiding may be utilized to elucidate the collagen structure. Also, tissue water content could be measured from the transmission profiles. These may be of use in diagnosis and repair of connective tissues.
STARMAP is a new, active star-configured, multiple access protocol designed particularly for very high-speed fiber optic LANs but equally applicable to lower speed copper based systems. The main features include: collision-free operation; no packet retransmissions; bounded access delay time; high degree of service fairness; no back-off algorithm required; an integrated data/voice transmission capability; a Universal, a Selective and a Local (Global & Selective) Broadcast capability; very high security; Local Selective Broadcast packets never leave the local hub; a relative insensitivity to `Master' hub failure; preemptive and nonpreemptive priority packet service scheme; novel variable delay register in the hubs; excellent natural diagnostic capability; Loop Creating Links significantly improve network performance; true parallel transmissions. Computer simulations of example STARMAP networks show that at typical values of the offered traffic load, the network throughput exceeds the link bit rate and in the limit, approaches a value equal to the product of the link bit rate and the number of hubs in the network. The useful life of twisted wire pair and coaxial cable based networks may be significantly extended due to the substantial increases in network throughput achievable.
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