Fluorescent ‘strip lights

Louis A. Bloomfield s entertaining book How Things Work The Physics of Everyday Life (second edition), Wiley, New York, 2001, discusses neon bulbs and fluorescent strip lighting, see pp. 395-399. For a more scientific look at fluorescent dyes, try Chapter 3 of Peter Bamfield s Chromic Phenomena (above), especially pp. 182-184. 

The spectral distribution of light emitted from a fluorescent strip light contains more UV component than does a normal tungsten bulb, and thus it will emit more photons of a sufficiently high energy to effect the degradation reaction shown in equation (9.6). 

Photopolymerisation in riboflavin-containing solution is induced by placing a fluorescent strip light a few centimetres from the tubes, and is accompanied by bleaching of the yellow riboflavin colour. 

The ceilings are perforated metal pans with insulation placed in the pans. These are effective both as sound deadeners and heat insulators. Lighting is by means of fluorescent strip lights set flush with the ceiling. 

By their nature lighting units emit heat the amount of heat will generally depend upon two factors, the wattage or energy consumption and the type of light, such as halogen lamps, incandescent units or fluorescent strip lighting. 

Lighting should be bright with spotlights over the stoyes, sink and worktops. Dimmer switches are required. Fluorescent strip lighting should be used as the general lighting. 

Inspect the paper in ultraviolet light—conveniently in front on a Hanovia ultraviolet strip light—in a dark room. The acids show up as intense blue fluorescent spots. Mark with a pencil the positions of all spots. The position of the two spots arising from solution (C) should be compared with the single spots arising from solutions (A) and (B). It is probable that the solution (B) of pure N-methylan-thranilic acid may also reveal a faint spot corresponding to anthranilic acid still present in minute traces in the methylated acid cf. p. 223). 

Photolytic breakdown is a big problem when we light the laboratory with fluorescent strips. 

Strip lighting in a classroom, hospital, business hall or kitchen is often called fluorescent lighting, although in fact it is a phosphorescent process, as above. Each bulb consists of a thin, hollow glass tube that is sealed at both ends. It contains gas such as helium, argon or krypton, and a drop of liquid mercury (about 0.5 mg of mercury per kilogram of lamp, or 0.5 parts per million). Like the neon and sodium lamps above, the pressure inside the tube is about 30 Pa, so the mercury evaporates to become a vapour. It is the mercury that yields the light, albeit indirectly. 

When the ascending solvent-front has reached a convenient height, the strip is removed, the position of the solvent-front marked, and the paper strip dried. The positions of the various solutes, if they are coloured compounds, now appear as clear separate spots. Frequently however, the solutes are colourless, and the position of their spots must be determined by indirect methods, such as their fluorescence in ultraviolet light, or their absorption in such light (when the spots appear almost black), or by spraying the paper with a dilute solution of a reagent which will give a coloured insoluble derivative with the solutes. 

Both these acids are colourless, but the spots of each acid on a filter-paper strip show up in ultraviolet light as intense blue fluorescent zones. They can also be detected, but considerably less sensitively, by spraying with ethanolic ferric chloride solution, which gives with N-methylanthranilic acid a purple-brown coloration. 

The performance of a biotreatment system ultimately depends on optimization of the activity of microbes and the ability to control the process parameters of the treatment system [157]. In this respect, the ability to monitor gene copy numbers and gene expression is highly useful for real time optimization of the efficiency of a biotreatment system. Advanced molecular techniques as well as low cost methods (e.g., antibody detection of enzymes based on color reaction strips fluorescence i.e., GFP marked organisms with UV light detection) can also be applied to monitor the microbial community structure, persistence of the added bacteria, and their interactions with indigenous populations. 

In this method the sediment is mixed with sodium sulphate and extracted with n-hexane. A portion of the extract is applied to a paper strip which is then eluted with petroleum ethenbenzene (35 65) for 60 seconds. Viewing of the strip under ultraviolet light reveals a blue fluorescent spot indicating the presence of oil in the sediment. 

Also, newer bills contain a plastic strip that is visible when the bill is held up to a light. The strips fluoresce in ultraviolet light 5—blue, 10-—orange, 20—yellow-green, 50—yellow-orange, and 100—pink. 

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