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pages 58-5

Primary Productivity in Lake Cochrane, South Dakota, During and After Sediment-Control Dam Construction

Lake Cochrane was selected for this study because of its history of superior water transparency (Haertel 1972, 1976b). Significant amounts of silt and chemicals enter the lake with runoff at 3 locations (Haertel unpublished data). Restriction or impediment of runoff at these locations should result in improved water transparency (Haertel 1976b, Siegel 1975). Therefore, East Dakota Conservancy Sub-District and the South Dakota Department of Wildlife, Parks, and Forestry decided to impede runoff waters by means of 3 sediment-control dams incorporated into the perimeter road system of the lake and financed through a grant from the Environmental Protection Agency (Siegel 1975) (Figure 1). The dams were designed to slow the movement of runoff water allowing sediment particles and sorbed nutrients to settle out . The objectives of this study were to: (1) evaluate the oxygen light and dark bottle method as a means of estimating primary productivity, and (2) estimate, during the open-water seasons, spatial and temporal variation of certain water quality parameters in Lake Cochrane during and after construction of the sediment-control dams

Lattice thermal conductivity of disordered NiPd and NiPt alloys

Numerical calculations of lattice thermal conductivity are reported for the binary alloys NiPd and NiPt. The present work is a continuation of an earlier paper by us [PRB, 72, 214207 (2005)]which had developed a theoretical framework for the calculation of configuration-averaged lattice thermal conductivity and thermal diffusivity in disordered alloys. The formulation was based on the augmented space theorem combined with a scattering diagram technique. In this paper we shall show dependence of the lattice thermal conductivity on a series of variables like phonon frequency, temperature and alloy composition. The temperature dependence of $\kappa(T)$ and its realtion to the measured thermal conductivity is discussed. The concentration dependence of $\kappa$ appears to justify the notion of a minimum thermal conductivity as discussed by Kittel, Slack and others. We also study the frequency and composition dependence of the thermal diffusivity averaged over modes. A numerical estimate of this quantity gives an idea about the location of mobility edge and the fraction of states in the frequency spectrum which is delocalized.Comment: 23 pages, 18 figure

Exact Solution of Photon Equation in Stationary G\"{o}del-type and G\"{o}del Space-Times

In this work the photon equation (massless Duffin-Kemmer-Petiau equation) is written expilicitly for general type of stationary G\"{o}del space-times and is solved exactly for G\"{o}del-type and G\"{o}del space-times. Harmonic oscillator behaviour of the solutions is discussed and energy spectrum of photon is obtained.Comment: 9 pages,RevTeX, no figure, revised for publicatio

Electronic structure, mechanical and thermodynamic properties of ThN from first-principles calculations

Lattice parameter, electronic structure, mechanical and thermodynamic properties of ThN are systematically studied using the projector-augmented-wave method and the generalized gradient approximation based on the density functional theory. The calculated electronic structure indicates the important contributions of Th 6\emph{d}and 5\emph{f} states to the Fermi-level electron occupation. Through Bader analysis it is found that the effective valencies in ThN can be represented as Th$^{+1.82}$ N$^{-1.82}$. Elastic constant calculations shows that ThN is mechanically stable and elastically anisotropic. Furthermore, the melting curve of ThN is presented up to 120 GPa. Based on the phonon dispersion data, our calculated specific heat capacities including both lattice and conduction-electron contributions agree well with experimental results in a wide range of temperature.Comment: 16 pages, 8 figure

Mobbing y síntomas depresivos en enfermeros de un hospital nacional de Lima 2023

El objetivo general de la presente investigación es determinar la relación entre el mobbing y los síntomas depresivos que sufren los enfermeros en un hospital nacional de Lima en el año 2023. El tipo de investigación es básica, el enfoque es cuantitativo y el nivel es correlacional. Se aplicó el Cuestionario de Conductas Negativas – Revisado (NAQ-R) y el Inventario de Depresión de Beck – II (BDI – II) a 70 enfermeros del servicio de hospitalización de un hospital nacional de Lima. Los resultados nos muestran que 31% de enfermeros encuestados sufre de mobbing y el 7% presentan síntomas depresivos. Además, el Rho de Spearman de la correlación entre estas dos variables es de 0.518, con una significancia de p < 0.001. En conclusión, el mobbing se relaciona de manera directa y significativa con los síntomas depresivos en los enfermeros de un Hospital Nacional de Lima