Lighting is an important factor in providing the appropriate learning environment at universities and educational facilities. It affects the learning outcomes and contributes to the aesthetic, psychological and health aspects of students, teachers and other users. Providing lighting is also costly and impacts on the environment. Thus, in choosing between competing lighting options an assessment...

This study evaluated the potential of high photosynthetic photon flux (PPF) from high-pressure sodium (HPS) lamps, alone or in combination with metal halide (MH) plus quartz iodide (QI) incandescent lamps, to support lettuce growth, with or without N supplementation. Varying exposures to radiation from combined HPS, MH, and QI lamps influenced dry weight gain and photosynthetic pigment content...

It will be observed that the period of time covered by the treatment is a little more than twelve months. At first only-two lamps were used?Lortet-Genoud, made by Marshall and Woods, of London ; but from May 23rd, 1902, two other lamps (constructed by Leslie Miller, of London) were added. The current used has been an interrupted one?five to ten amperes, about twelve volts, and the time of each ...

Energy-efficient lighting is one of the key measures for addressing electric power shortages and climate change mitigation, and fluorescent lamps are expected to dominate the lighting market in China over the next several years. This review presents an overview on the emissions and risk of mercury from fluorescent lamps during production and disposal, and discusses measures for reducing the mer...

With the kind permission of Leisure and Cultural Services Department (LCSD), Energy Efficiency Office (EEO) of Electrical and Mechanical Services Department (EMSD) completed a pilot lighting project in 2002 at Kowloon Bay Indoor Games Hall (KBIGH). The new lighting system made use of the latest T5 lighting technology for illuminating the high ceiling games hall. As compared with the existing hi...

Dimming fluorescent lamps is an attractive feature that provides mood and brightness effects as well as having tremendous energy savings potential. Designing a dimmable electronic ballast, however, is a complicated and challenging task. This paper presents an overview for designing a dimming electronic ballast for a T5 35W lamp. Lamp requirements, dimming control methods, and resonant output st...

Fluorescent lamps are estimated to annually release 1 t of mercury into the air in the United States; transport of used lamps may play an important role in these emissions. In 1999, the U.S. Environmental Protection Agency added lamps to the universal waste rule to encourage recycling by allowing shipment to recycling facilities by common carrier. The rules required that lamp packaging must be ...

Objective: The use of miniature X-ray source in electronic brachytherapy is on the rise so there is an urgent need to acquire more knowledge on X-ray spectrum production and distribution by a dose. The aim of this research was to investigate the influence of target thickness and geometry at the source of miniature X-ray tube on tube output.Method: Five sources were simulated based on problems e...

 In this paper an analysis of conducted harmonic emissions of different types of lamps is presented. The growing use of non-linear loads (pc, printers, electronic devices, etc.) connected to power supply systems and their variability with time, are responsible of a continuously changing harmonic content in the distribution system. Therefore, to analyze their real behaviour, the lamps were test...