Tripod

Two other examples will sufhce. Methane physisorbs on NaCl(lOO) and an early study showed that the symmetrical, IR-inactive v mode could now be observed [97]. In more recent work, polarized FTIR rehection spectroscopy was used to determine that on being adsorbed, the three-fold degeneracies of the vs and v modes were partially removed [98]. This hnding allowed consideration of possible adsorbate-adsorbent geometries one was that of a tripod with three of the methane hydrogens on the surface. The systems were at between 4 and 40 K so that the equilibrium pressure was very low, about 10 atm. 

Place 50 g. (57 ml.) of dry A.R. benzene and 0 5 ml. of dry p rridine (1) (dried over potassium hydroxide pellets) in a 500 ml. round-bottomed flask. Attach a reflux condenser to the flask and an inverted funnel (just dipping into some water in a beaker) to the top of the condenser (Fig. II, 13, 8, b). Partially immerse the flask in a bath of cold water, supported upon a tripod and gauze. Carefully pour 125 g, (40 ml.) of bromine (for precautions to be taken with bromine, see Section 111,35, Note 1) through a condenser and immediately insert the absorption device into the upper end of the condenser. A vigorous reaction soon occurs and hydrogen bromide is evolved which is absorbed by the water in the beaker when the reaction slackens, warm the bath to 25-30° for... 

When finest grain stmcture and maximum image sharpness are required, the original is photographed in a large-format camera using a separate sheet of film for each exposure. These cameras are heavier than roll-film cameras and usually require a tripod and/or a controlled studio environment. Common sheet film sizes include 102 x 127 mm (4x5 in.) and 203 x 254 mm (8 x 10 in.). 

Classic A/-heterocychc ligands, eg, bipyridyl (bipy), terpyridyl, imidazole, pyrazine, phenanthroline, piperazine (including alkyl- and aryl-substituted derivatives), and polypyrazol-l-yl-borates (bis, tris, and tetra), have all been found to coordinate Th(IV) chlorides, perchlorates, and nitrates. The tripodal hydrotris(pyrazolyl)borates, HBPz, have been used to stabilize organometaHic complexes (31). Bis-porphyrin Th(IV) "sandwich" complexes have been... 

Usually, in AFM the position of the tip is fixed and the sample is raster-scanned. After manual course approach with fine-thread screws, motion of the sample is performed with a piezo translator made of piezo ceramics like e. g. lead zirconate tita-nate (PZT), which can be either a piezo tripod or a single tube scanner. Single tube scanners are more difficult to calibrate, but they can be built more rigid and are thus less sensitive towards vibrational perturbations. 

I come now to the second leg of our notional tripod - phase equilibria. 

To recapitulate, the legs of the imaginary tripod on which the structure of materials science is assembled are atoms and crystals phase equilibria microstructure. Of course, these are not wholly independent fields of study. Microstructure consists of phases geometrically disposed, phases are controlled by Gibbsian thermodynamics. 

The first tank was cleaned without incident. By the time the contractors started on the second tank, a new foreman was in charge. To soften the deposits, he disconnected the steam coil, blew live steam into the tank, and then sprayed kerosene onto the walls, section by section, using a spinner mounted on a tripod. The report does not make it clear whether or not the kerosene was heated. While men were moving the tripod, a fire started in the tank, followed by an explosion. Three men were icilled. one by the fire and tw o by falling bits of the external concrete cladding. 

Address 97, KRS Road Metagalli, Mysore 570 016 India Phone +91 821 511985 E-mail topnote 123 yahoo.com Web site http //topnote.tripod.com... 

The benefits claimed for the TRIPOD approach are that it provides a consistent method for auditing a situation to identify deficiencies in the factors that are likely to give rise to errors. These deficiencies can then be corrected to reduce the likelihood of accidents occurring in the future. 

FIGURE 2.10 TRIPOD Failure-State Profiles of Two Production Platforms (Wagenaar, 1992). 

HFAM has 20 groups of factors instead of the 10 general failure types of the TRIPOD approach. The reason for this is that all of the 10 TRIPOD GFTs would be applied in all situations, even though the actual questions that make up the factors may vary. In the case of HFAM, it would be rare to apply all of the factors unless an entire plant was being evaluated. HFAM uses a screening process to first identify the major areas vulnerable to human error. The generic factors and appropriate job specific factors are then applied to these areas. For example, control room questions would not be applied to maintenance jobs. 

Another link exists between the PIF concept and the sociotechnical assessment methods described in Section 2.7 The checklists used in the TRIPOD methodology are essentially binary questions which evaluate whether the sets of PIFs making up each of the general failure types are adequate or not. The hierarchical sets of factors in HRAM are essentially PIFs which are expressed at increasingly finer levels of definition, as required by the analyst. The audit tool which forms MANAGER also comprises items which can be regarded as PIFs which assess both management level and direct PIFs such as procedures. 

It should be emphasized that the PIFs considered in this chapter, although generally considered important by human reliability specialists, are not meant to be exhaustive in their coverage. Other selections, such as those considered by the methods such as TRIPOD and HP AM (Chapter 2), are possible. It is recommended that the advice of an experienced human reliability or human factors specialist is sought when deciding which PIFs should be covered in a specific situation. 

Other 5-coordinate Co compounds which have been characterized include [CoBr- N(C2H4NMe2)3 ]+, which is high-spin with 3 unpaired electrons and is trigonal bipyra-midal (imposed by the tripod ligand), and... 

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