Stairs visibility

An interesting and powerful new development in Raman spectroscopy of catalysts is the use of a UV laser to excite the sample. This has two major advantages. First, the scattering cross section, which varies with the fourth power of the frequency, is substantially increased. Second, the Raman peaks shift out of the visible region of the spectrum where fluorescence occurs. The reader is referred to Li and Stair for applications of UV Raman spectroscopy on catalysts [40]. 

FIGURE 8.12. The speculated mechanism for the stoichiometric splitting of water with visible light using tungsten oxide and titanium oxide. Note the stair-step mechanism. From Sayama et al. 

Many odd people come calling on the Maestro, but probably no couple I have ever found waiting out there at the top of the stairs has surprised me more. The woman was swathed from the ground up in the habit of a Benedictine nun, with only her fingers visible to show that there was a woman inside that menacing pillar of black. The man at her side, gray robed and tonsured, was the third Michiel son, the former Timoteo. I bowed to his austere. Old Testament stare. 

I know I m not alone in my experience through conversations with my girlfriends. One told me of how she went back to her car to pump (and hoped that nobody left early that day). Another hung a Do Not Enter sign on the bottom of a set of stairs to a loft, since the entire office she worked in was visible on the main floor. A third told me about having to explain to her male coworkers that when her office door was closed, it meant that she was available neither to answer the door nor to pick up the phone (which they routinely tried two minutes later). 

Volume 50 of Advances in Catalysis, published in 2006, was the hrst of a set of three focused on physical characterization of solid catalysts in the functioning state. This volume is the second in the set. The hrst four chapters are devoted to vibrational spectroscopies, including Fourier transform infrared (Lamberti et al.), ultraviolet Raman (Stair), inelastic neutron scattering (Albers and Parker), and infrared-visible sum frequency generation and polarization-modulation infrared rehection absorption (Rupprechter). Additional chapters deal with electron paramagnetic resonance (EPR) (Bruckner) and Mossbauer spectroscopies (Millet) and oscillating microbalance catalytic reactors (Chen et al.). 

Chua, Y.T., Stair, P.C. and Wachs, l.E. (2001) A comparison of ultraviolet and visible raman spectra of supported metal oxide catalysts. Journal of Physical Chemistry B, 105 (36), 8600-6. 

In this chapter we are dealing mainly with absorption of ultraviolet or visible pk iation, because its wavelength can be easily varied and this indicates exactly what where we are exciting. As H.A. Klasens, a pioneer in luminescent materials, used > iay ultraviolet excitation compares to striking one key of the piano, cathode-ray X-ray excitation compares to throwing the piano down the stairs. 

There are several factors that affect stairs safety. They include uniformity of dimensions, resistance, slope, visibility, stmcrnral strength, width, tread depth, placement, and other feamres. 

Visibility Visibility on stairs is very important. It includes having enough light to see steps easily and avoiding glare that obscures the ability to see steps. For example, a window or door located at the base of a stairway can create glare that makes it difficult to see steps. 

Minimum lighting levels in some standards require 1-5 footcandles of light. However, when one enters a building from bright, sunny outdoor conditions, minimum lighting levels for stairs are inadequate. Someone s eyes do not have time to adjust quickly to the lower light levels. Reduced visibility may lead to a fall. 

Because every second counts in successfully treating injured eyes and because an injured worker s vision is diminished, it is imperative that the path to an eyewash station be short, clearly marked and unobstructed. ANSI specifies that stations be located within a 10-second walk from the hazard on a travel path free of obstructions. The station must be located on the same level as the hazard with no steps or stairs, and immediately adjacent to strong caustics and strong acids. The area surrounding the eyewash station should be well ht and marked with a sign that is highly visible to everyone served by it. 

Stair rails should be highly visible, often of a different color from the stairs themselves. 

Fig.4.1 Antiskidding stripes would improve visibility of steps on a stair case...

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