The decay of neutron deficient97Ag,98Ag,and99g,m Ag

The decays of neutron-deficient 21-sec⁹⁷Ag, 44.5-sec⁹⁸Ag, 15-sec^99mAg, and 124-sec^99gAg nuclides have been investigated with the LISOL facility. Sources were produced by the⁹²Mo(¹⁴N, ypxn) reactions on an enriched⁹²Mo target. Positron-, x-, and γ-ray singles spectra have been performed on mass separated samples. The results are consistent with 9/2⁺ ground state in⁹⁹Ag and a high (6⁺ or 7⁺) spin and parity for⁹⁸Ag.     

Elastico-viscous squeeze films: Part 2. superimposed rotation

The first part of this paper contains a reconsideration of the conventional squeeze-film situation. It is shown that the Part 1 concentration on the half-time t_{$\text{1}\text{2}$} sometimes hides interesting elastico-viscous effects, since these are most pronounced at short times after the load is applied.The bulk of the paper is concerned with the more general situation in which a rotational flow is superimposed on the basic squeezing flow. This is brought about by rotating the bottom plate. An approximate theoretical analysis is shown to lead to a satisfactory prediction of observed behaviour under conditions of light loading.The experiments show substantial transient stress-overshoot effects under some conditions and there is also a possible indication of long-range memory effects in some of the experiments.     

A new tricyclic triketone from tandem condensation reactions

Perhydrophenanthrene-1,5,10-trione (6) was isolated from the reaction of methyl 3-(carboxymethyl)cyclohexanone and cyclohexenone in a tandem Michael-Claisen reaction. NMR and X-ray analysis confirmed the structure of the product.     

A note on the motion of a viscous liquid in a rotating straight pipe

Résumé On fait une analyse de l'écoulement laminaire de liquides newtoniens dans des tuyaux cylindriques tournant autor d'un axe perpendiculaire à l'axe du tuyau, l'écoulement étant celui induit par un gradient de pression constant. On donne des calculs explicites dans les cas du luyau circulaire et du tuyau rectangulaire.     

A note on the formulation of simple equations of state for elastico-viscous liquids

Résumé On a consideré la formulation de simples équations d'état qui décrivent approximativement la conduite observée des liquides elastico-visqueux et qui sont suffisamment simples pour être utiles à résoudre des problèmes d'écoulement général.     

Design of a large,rigid, modular optical bed for versatile optical and spectroscopic experimentation

Described is a mechanically-rigid and referenceable, vibrationally-isolated, modular optical support bed which has demonstrated significant utility in recent research on the physical—chemical nature of the atmospheric pressure spark discharge. By interconnecting an assembly of pre-aligned, truss-like sub-structures, a complete instrumental complex has been fabricated which exhibits high mechanical stability. This stability is sufficient to allow alignment of, for example, a 5 m focal length, high-dispersion optical spectrometer, to be maintained for months without detectable degradation. The approach is versatile and can be easily extended to include a wide variety of optical and other research applications. Supporting mechanical, vibration, and optical data are included as well as documentation of fabrication details.     

Particulates formed by a stabilized high voltage spark discharge

Light scattering was used to demonstrate the presence of small (?1 μm) particles in the immediate surroundings of a stable spark discharge. Several parameters, including electrode composition and surface condition, which are of importance in emission spectrochemical analysis, were found to be of importance in affecting the scattering signal. Electron micrographs of the heaviest particles revealed two distinct types of particles. Analytical implications are discussed.     

Effects of humidity on the weathering of glass

The weathering of 26 glass compositions was investigated under static conditions of 30%, 50%, 75%, 90% and 98% relative humidity (RH) at 50°C and a cycling condition between 77% and 98% RH at 50°C. The cycling condition was found to be less severe than static 98% RH. The effect of humidity level on weathering was studied and showed that water adsorption increases with time and humidity, whereas alkali generation increases with time, but not always with humidity. Significant weathering occurs for some glasses at 30% RH with the quantitative effect being almost as great as at 90% RH. Visual weathering was observed for some glasses when the level of generated alkali was less than 0.5 μg/cm².Various techniques for evaluating the weathering of glass under humid conditions were investigated. Visual appearance was judged to be the best evaluation method for routine weathering tests. It represents the effect of most concern and is sufficiently precise. Electron microscopy, measurement of sorbed water and alkali generated are principally used for research studies. Weight change and haze measurement lack sensitivity and reproducibility. A standard test was defined. The conditions are 98% RH at 50°C for 12 weeks. The visual ranking system is used. The glasses were generally ranked in the same order by the various evaluation techniques.