Open-ended activities

Open End Activity (OEA) An Experience in Computer Graphics Laboratory... 

The tubular positive plate uses rigid, porous fiber glass tubes covered with a perforated plastic foil as the active material retainer (Fig. 2). Dry lead oxide, PbO, and red lead, Pb O, are typically shaken into the tubes which are threaded over the grid spines. The open end is then sealed by a polyethylene bar. Patents describe a procedure for making a type of tube for the tubular positive plate (90) and a method for filling tubular plates of lead—acid batteries (91). Tubular positive plates are pickled by soaking in a sulfate solution and are then cured. Some proceed directiy to formation and do not requite the curing procedure. 

The first of the open-ended problems to be considered is nuclear weapons proliferation, in the context of its relation to commercial nuclear power. There is a connection, because a country with an active nuclear power program has a head start, in terms of equipment and technically trained people, should it decide to embark upon a weapons program. This has been a live issue in the case of han.5... 

To activate the delay, first fasten the container securely in an upright position. Make a hole in the side of the container near the bottom and insert the open end of a nonelectric blasting cap. Be sure that some of the sugar-chlorate mix gets into the open end of the cap. The business end of the blasting cap can be inserted directly into the explosive charge or connected to the charge with primacord. To start the delay, carefully place a spoonful of concentrated acid in the pocket of the membrane—... 

After exposure, the outside surface of the cast was cleansed until the activity of the washes was less than 10X the background of a gamma well scintillation counter. The cast was cut into separate bifurcations and airway sections and each section was counted to determine the amount of aerosol deposited. Sane samples contained both airway and bifurcation sections because of the complex configuration of the cast. For combination samples, the total activity deposited was equally apportioned between each of the airways and bifurcations. End airways were included for determination or total deposition but not in any of the analyses because flow disturbances at open ends may have affected deposition. The surface area of each sample was measured separately. The surface density for each cast segment was calculated by dividing the activity measured in the sample by the interior surface area of that sample. 

X-ray crystal structures of glutamine synthetase from both Salmonella typhimuriuni and Mycobacterium tuberculosis are very similar. Structures of wild type enzymes and of active site mutants have been determined. All structures have been solved with Mn in the active site. There are twelve identical subunits arranged in two face-to-face symmetrical hexamers. The active sites are in funnel-shaped open-ended cavities located between adjacent subunits of the hexamer. These cavities are 45 A long, 30 A wide at the outer end, and 10 A wide at the inner end and the active site with the two Mn " ions is approximately halfway down the cavity. The metal-metal distance is 5.8 A. The more tightly bound Mn is coordinated to the side chains of Glu-131, Glu-212, Glu-220, and two water molecules, one of which is shared by both metal ions. Glu-129, Glu-357, His-269, and two additional water molecules are bound to the Mn + at the lower affinity site. A schematic view of the active site metal coordination is shown in Figure 36. 

This book consists of eight chapters. Chapters 2, 3 and 4 give methodological background and reviews. Chapters 5 to 8 carry the applications both in the field of analytical chemistry and pharmaceutical formulations. Since the field of which this book tries to give an overview is still under active research, this book is by no means a monograph with well established and tested methods. There are still a lot of questions and open ends. This book, however, does give some ideas how to tackle the problems of robustness. 

The non-precipitated withdrawal procedure described above represents an open-ended screen for dependence liability. The procedure can be rendered more discriminating, by pre-exposing the animals to the same administration schedule and then testing them in procedures with more specific indications. For example, withdrawal-induced fearfulness could be assessed by using a plus-maze appropriately calibrated to detect anxiogenic activity. Similarly, a withdrawal-induced... 

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