A Survey of the Arithmetical Concepts of Children in the Elementary Grades Pertaining to the Use of Money

It was the purpose of this study: (1) to survey the present concepts of money and its use, in a specific elementary grade level, in a cross section of a city that included all socio-economic levels; (2) to determine the extent to which knowledge of economic concepts is related to socio-economic level; and (3) make suggestions as to areas where greater emphasis towards understanding of money concepts should be placed

Non-Isothermal Mercury Pipe Flow Turbulent Characteristics

The turbulence structure of fully-developed mercury pipe flow, with and without heat transfer, was studied using hot-film anemometry at Reynolds number of approximately 50,000. Single sensors and slanted multiple sensors were used to obtain the radial distribution of axial fluctuating velocity and temperature quantities. Isothermal data were generally in good agreement with comparable air data indicating similar velocity structure. Temperature intensity data agreed with other data in liquid metals. Axial and radial turbulent heat flux results were somewhat inconclusive. Spectra and turbulence scales were developed providing a picture of the structure

Long-range potentials and (n−1)d+ns(n-1)d+ns molecular resonances in an ultracold rydberg gas

We have calculated long-range molecular potentials of the $0_g^{+}$, $0_u^{-}$ and $1_u$ symmetries between highly-excited rubidium atoms. Strong $np+np$ potentials characterized by these symmetries are important in describing interaction-induced phenomena in the excitation spectra of high $np$ Rydberg states. Long-range molecular resonances are such phenomena and they were first reported in S.M. Farooqi {\it et al.}, Phys. Rev. Lett. {\bf 91} 183002. One class of these resonances occurs at energies corresponding to excited atom pairs $(n-1)d+ns$. Such resonances are attributed to $\ell$-mixing due to Rydberg-Rydberg interactions so that otherwise forbidden molecular transitions become allowed. We calculate molecular potentials in Hund's case (c), use them to find the resonance lineshape and compare to experimental results.Comment: 11 pages, 7 figure