Assessment of simple filter systems for treating run-off from seasonal livestock areas

Non-Peer ReviewedCattle wintering sites and calving grounds are frequently located on dissected terrain. In many of these areas there is a high risk of contamination to stream headwaters from on-site run-off, particularly in the spring. A literature review suggested a number of small- or municipal-scale filter treatments that may have potential for treating run-off in terms of reducing nutrient and pathogen concentrations. If effective, such systems may provide a low-cost, low-maintenance system for treating run-off in these situations. A two-year bench scale trial was initiated in 2006 at two sites to test the effectiveness of four filter technologies. The technologies were chosen based on several criteria which included: capital and maintenance costs, simplicity, known effectiveness, space requirements, and the ability to scale down the technology. The four selected filters were: demand-operated slow sand filter, intermittent flow sand filter, intermittent flow wood chip filter, and continuous flow rock filter. The trial and filters are described and preliminary results obtained starting in July, 2006 are presented. First year results suggest that the slow sand filter is not a viable technology but the intermittent flow filters and the rock filter show promise

Phonon `notches' in a-b -plane optical conductivity of high-Tc superconductors

It is shown that a correlation between the positions of the $c$-axis longitudinal optic ($LO_c$) phonons and ``notch''-like structures in the $a$-$b$ plane conductivity of high-$T_c$ superconductors results from phonon-mediated interaction between electrons in different layers. It is found that the relative size of the notches depends on $\lambda_{ph}(\Omega_{ph}/\gamma_{ph})$, where $\lambda_{ph}$, $\Omega_{ph}$ and $\gamma_{ph}$ are the effective coupling strength, the frequency and the width of the optical phonon which is responsible for the notch. Even for $\lambda_{ph}\approx 0.01$ the effect can be large if the phonon is very sharp.Comment: 5 pages, REVTeX, 4 uuencoded figure

Scaling of transition temerature and CuO_2 plane buckling in the cuprate superconductors

Recently it is seen\cite{Nature},that both $\rm{T}_c$ and the buckling of the $CuO_2$ planes goes through a maximum at the same doping level. We show that only for optimal doping concentration the Fermi surface touches the M($0,\pi$) point in the BZ, where the matrix element for interlayer pair tunneling amplitude is largest, so that the gain in delocalization energy by tunneling(in pairs) along the $c$ axis is largest. Buckling of the planes on the other hand modulates the separation between the planes and thereby modulates the interlayer pair tunneling amplitude. That is why both $\rm{T}_c$ and buckling angle(Oxygen atom displacement out of the plane) scales the same way with doping concentration. We have calculated $\rm{T}_c$ and buckling angle for various doping concentration. The agreement with experiment is remarkably good. We also point out the possible reason for large(about 1 percent) change of the buckling mode phonon frequency, accross the transition temperature. scatteringComment: Summitted to Physics C, Journal of Superconductivity, 6 pages Tex file with 4 postscript files attache

Moral distress in emergency departments : experiences of registered nurses

The purpose of the study is to determine whether registered nurses are experiencing moral distress while working in emergency departments, and if so, the causes and their reactions to the phenomenon. Registered nurses currently employed in an in emergency department engaged in semi-structured interviews to examine the phenomenon. This study utilized narrative inquiry research design as advocated by Reissman (2008). Findings indicated that registered nurses are experiencing moral distress in emergency departments related to myriad pressures and demands forcing simultaneous decisions primarily related to use of the finite number of resources at their disposal and the provision of futile care. Participants’ reactions to moral distress included acknowledging that they will continue to find themselves in morally distressing situations, passion for their jobs despite encountering morally stressing situations, and an ability to manage negative effects of moral distress related to their personalities and the nature of the working relationships that exist within emergency departments. Findings indicate that health care administrators, staff, and physicians require increased awareness of the phenomenon if they wish to address and mitigate these situations

Riparian buffer design tool for cropland: lotic systems

Non-Peer ReviewedRiparian areas function as a buffer between the upland and the aquatic systems. This area is unique in its structure and the services it provides intercepting non-point source (NPS) pollution from the upland. In some cases additional buffer width may be required or sought. Riparian buffer strips are a beneficial management practice (BMP) eligible for cost-shared funding under government programs. However, little information is available to assist landowners in appropriate location or design considerations. This project aims to create a riparian buffer design tool to be utilized on lotic (flowing water) systems in cropland settings. This tool will consist of a flow chart and accompanying key. The flow chart along with air photographs, soils maps and discussions with the landowner will help to determine where on the landscape a buffer should be located. The final product will include case studies and guiding documents for technical staff to utilize when assisting landowners with their riparian buffer strips

Polarized far-infrared and Raman spectra of SrCuO2 single crystals

We measured polarized far-infrared reflectivity and Raman scattering spectra of SrCuO$_2$ single crystals. The frequencies for infrared-active modes were determined using an oscillator-fitting procedure of reflectivity data. The Raman spectra were measured at different temperatures using several laser energies $\omega_L$. In addition to eight of twelve Raman active modes, predicted by factor-group analysis, we observed a complex structure in the Raman spectra for polarization parallel to the {\bf c}-axis, which consists of Raman-allowed A$_g$ symmetry modes, and B$_{1u}$ LO infrared-active (Raman-forbidden) modes of the first and higher order as well as their combinations. The Raman-forbidden modes have a stronger intensity at higher $\omega_L$ than the Raman-allowed ones. In order to explain this resonance effect, we measured the dielectric function and optical reflection spectra of SrCuO$_2$ in the visible range. We show that the Raman-allowed A$_g$ symmetry modes are resonantly enhanced when a laser energy is close to $E_0$, while Raman-forbidden (IR-active) modes resonate strongly for laser line energies close to the electronic transition of higher energy gaps.Comment: to be published in Physica

Heavy-Fermion Formation at the Metal-to-Insulator Transition in Gd1−x_{1-x}Srx_xTiO3_3

The perovskite-like transition-metal oxide Gd$_{1-x}$Sr$_x$TiO$_3$ is investigated by measurements of resistivity, specific-heat, and electron paramagnetic resonance (EPR). Approaching the metal-to-insulator transition from the metallic regime ($x \geq 0.2$), the Sommerfeld coefficient $\gamma$ of the specific heat becomes strongly enhanced and the resistivity increases quadratically at low temperatures, which both are fingerprints of strong electronic correlations. The temperature dependence of the dynamic susceptibility, as determined from the Gd$^{3+}$-EPR linewidth, signals the importance of strong spin fluctuations, as observed in heavy-fermion compounds.Comment: 4pages, 3 figure

Phonons and Magnetic Excitations in Mott-Insulator LaTiO3_3

The polarized Raman spectra of stoichiometric LaTiO$_3$ (T$_N = 150$ K) were measured between 6 and 300 K. In contrast to earlier report on half-metallic LaTiO$_{3.02}$, neither strong background scattering, nor Fano shape of the Raman lines was observed. The high frequency phonon line at 655 cm$^{-1}$ exhibits anomalous softening below T$_N$: a signature for structural rearrangement. The assignment of the Raman lines was done by comparison to the calculations of lattice dynamics and the nature of structural changes upon magnetic ordering are discussed. The broad Raman band, which appears in the antiferromagnetic phase, is assigned to two-magnon scattering. The estimated superexchange constant $J = 15.4\pm0.5$ meV is in excellent agreement with the result of neutron scattering studies.Comment: 4 pages, 5 figure

Low-Temperature Phase of the Cd2_2Re2_2O7_7 Superconductor: Ab initio Phonon Calculations and Raman Scattering

Using an {\it ab initio} approach, we report a phonon soft mode in the tetragonal structure described by the space group $I4_{1}22$ of the $1$ K $5d$ superconductor Cd$_2$Re$_2$O$_7$. It induces an orthorhombic distortion to a crystal structure described by the space group $F222$ which hosts the superconducting state. This new phase has a lower total energy than the other known crystal structures of Cd$_2$Re$_2$O$_7$. Comprehensive temperature dependent Raman scattering experiments on isotope enriched samples, $^{116}$Cd$_2$Re$_2{^{18}}$O$_7$, not only confirm the already known structural phase transitions but also allow us to identify a new characteristic temperature regime around $\sim 80$ K, below which the Raman spectra undergo remarkable changes with the development of several sharp modes and mode splitting. Together with the results of the \textit{ab initio} phonon calculations we take these observations as strong evidence for another phase transition to a novel low-temperature crystal structure of Cd$_2$Re$_2$O$_7$.Comment: 7 pages, 8 figure