Fluorescent lamp sizes

California and Minnesota have placed restrictions on the disposal of fluorescent light tubes, which contain from 40—50 mg of mercury per tube, depending on size. After batteries, fluorescent lamps are the second largest contributor of mercury in soHd waste streams in the United States (3,14). A California law classifies the disposal of 25 or more fluorescent lamp tubes as hazardous waste. In Minnesota, all waste lamps generated from commercial sources are considered hazardous waste. Private homes are, however, exempt from the law (14). Other states have proposed similar regulations. Several companies have developed technologies for recovering mercury from spent lamps (14). 

Fluorescent lamps are manufactured by squirting a suspension of phosphor particles in an ethyl cellulose lacquer upon the inner surface of a vertical glass tube. Once the lacquer drains off, a film of peuticles is formed. The lacquer is then burned off, leaving a layer of phosphor particles. Electrodes are sealed on the tube is evacuated Hg and inert gas is added and the lamp ends are added to finish the lamp. Lamp brightness and lifetime are dependent upon the particle size distribution of the phosphor particles. The number of small particles is critical since they are low in brightness output... 

Spent fluorescent lamps, as well as mercury vapor lamps, contain sufficient mercury to qualify as toxic hazardous wastes under Section 66699 (b) of the California Code of Regulations (CCR). At present, a generator may dispose of no more than 25 spent fluorescent light tubes and/or mercury vapor lamps at a time, regardless of size. The EPA, too, has concluded that fluorescent lamps can in sufficient quantities be considered hazardous waste under 40 CFR 261.24 (Quicksilver 1989). 

The following table, shown on the next page, gives a comparison of the various sizes of fluorescent lamps currently available. 

Conventional light sources A significant amount of research has been done to develop more intense conventional sources to increase the fluorescence signal size. Conventional light sources that have been used for AES include hollow cathode lamps (HCLs), electrodeless discharge lamps (EDLs), and continuum sources. 

CFLs are miniature fluorescent lamps designed to replace ordinary GLS lamps. They are available In a variety of shapes and sizes so that they can be fitted into... 

There is a demand for larger and larger liquid crystal devices (e.g., LCD TVs). As the size of a display increases, the number of light sources (e.g., cold cathode fluorescent lamps (CCFL)) used to backhght the display can also increase. Polycarbonate (PC) films are preferred in larger displays compared to aciyhc or styrenic plastics due to better thermal and dimensional stability. 

Fig. 17 Cadmium selenide QDs, dissolved in toluene, fluorescing brightly in the presence of a ultraviolet lamp, in three noticeably different colors (blue 481 nm, green 520 nm, and orange 612 nm). The blue QDs have the smallest particle size, the green dots are slightly larger, and the orange dots are the largest. (Adapted from http //www. amazingrust.com/ experiments/current proj ects / Misc.html)...

Figure 22. Human embryonic kidney cells (A), rat vascular smooth muscle cells (B, C) and human osteoblast-like MG 63 cells (D) in cultures on micropattemed surfaces. A, B PTFE irradiated with UV light produced by a Xe2 -excimer lamp for 30 min in an ammonia atmosphere through a mask with holes 100 pm in diameter and center-to-center distance 300 pm C PE irradiated with Ar ions (energy 150 keV, ion dose lO ions/cm ) through a mask with holes 100 pm in diameter and center-to-center distance 200 pm fullerenes Qo deposited through a mask with rectangular holes with an average size of 128 3 pm per 98 8 pm on glass coverslips. Day 7 after seeding. A native cells in an inverted phase-contrast microscope B, C cells stained with hematoxylin and eosin, Olympus microscope IX 50 D cells stained with fluorescence-based LIVE/DEAD viability/cytotoxicity kit (Invitrogen), Olympus microscope IX 50. Bars 300 pm (A), 200 pm (B, D), Imm (C) [10,11].

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