The reaction of BF3(g) with B2O3(l) was studied by the transpiration method in the temperature range 600° to 1100°K. Results indicate the reaction to be BF3(g)+B2O3(l)=(BOF)3(g).ΔH298° was found to be 4.2 kcal, and leads to ΔHf298°=—566.8±1 kcal/mole for (BOF)3(g).
The vapor above mixtures of MgF2 and B2O3 contained in a Knudsen cell was analyzed with a mass spectrometer and was found to contain BF3(g), (BOF)3(g), and BOF(g) in the range 980° to 1230°K. From studies of the temperature dependence of appropriate ion intensities the heat of the reaction (BOF)3(g)=3BOF(g)was derived as 131 kcal at 1125°K. Use of low ionizing electron energies was required to avoid fragmentation effects. The heat of formation of BOF(g) at 298°K was calculated to be —144±3 kcal/mole.
This paper reports the effect of procedures known to alter local blood flow upon the rate of removal of locally injected Na
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and I
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. An evaluation of this clearance method as a measure of nutritive blood flow is made. A second purpose is to report the lack of effect upon clearance from calf muscle of lumbar sympathetic block, and to discuss its therapeutic implications.
Drawing as a form of analytical inscription can provide researchers with highly flexible methods for exploring embodied interaction. Graphical techniques can combine spatial layouts, trajectories of action and anatomical detail, as well as rich descriptions of movement and temporal effects. This paper introduces some of the possibilities and challenges of adapting graphical techniques from life drawing and still life for interaction research. We demonstrate how many of these techniques are used in interaction research by illustrating the postural configurations and movements of participants in a ballet class. We then discuss a prototype software tool that is being developed to support interaction analysis specifically in the context of a collaborative data analysis session.
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