3,383 research outputs found
A Reading Lesson Observation Framework for Elementary Teachers, Principals, and Literacy Supervisors
Henk et al present a framework which will provide reference points for assessment and help refine instructional practices in reading
AN AGRICULTURAL VALUE TAX AS AN ALTERNATIVE TO LAND USE TAX OR MARKET VALUE TAX ON LAND
Public Economics,
The Writing Observation Framework: A Guide for Refining and Validating Writing Instruction
The Writing Observation Framework (WOF) is a new tool for enhancing writing instruction in schools. The WOF organizes principles of writing instruction In a way that improves the evaluation of teachers\u27 writing practices, encourages a shared philosophy of the writing process and its instruction, and assists schools in demonstrating the integrity of their writing programs
Influence of higher d-wave gap harmonics on the dynamical magnetic susceptibility of high-temperature superconductors
Using a fermiology approach to the computation of the magnetic susceptibility
measured by neutron scattering in hole-doped high-Tc superconductors, we
estimate the effects on the incommensurate peaks caused by higher d-wave
harmonics of the superconducting order parameter induced by underdoping. The
input parameters for the Fermi surface and d-wave gap are taken directly from
angle resolved photoemission (ARPES) experiments on Bi{2}Sr{2}CaCu{2}O{8+x}
(Bi2212). We find that higher d-wave harmonics lower the momentum dependent
spin gap at the incommensurate peaks as measured by the lowest spectral edge of
the imaginary part in the frequency dependence of the magnetic susceptibility
of Bi2212. This effect is robust whenever the fermiology approach captures the
physics of high-Tc superconductors. At energies above the resonance we observe
diagonal incommensurate peaks. We show that the crossover from parallel
incommensuration below the resonance energy to diagonal incommensuration above
it is connected to the values and the degeneracies of the minima of the
2-particle energy continuum.Comment: 13 pages, 7 figure
Boron isotope effect in single crystals of ErNiBC superconductor
The influence of local moment magnetism on the boron isotope effect of T
was studied on single crystals of ErNiBC. Values of the partial isotope
effect exponent of =0.100.02 and =0.100.04 were
obtained based on two different criteria applied to extract . No
significant change in the partial isotope effect exponent compared to the ones
obtained for LuNiBC was observed. Based on this result we conclude that
pair-breaking due to the Er local magnetic moment appears to have no detectable
influence on boron isotope effect of T.Comment: 7 pages, 3 figure
Carbon isotope fractionation during aerobic biodegradation of trichloroethene by Burkholderia cepacia G4: a tool to map degradation mechanisms
The strain Burkholderia cepacia G4 aerobically mineralized trichloroethene (TCE) to CO2 over a time period of similar to20 h. Three biodegradation experiments were conducted with different bacterial optical densities at 540 nm (OD(540)s) in order to test whether isotope fractionation was consistent. The resulting TCE degradation was 93, 83.8, and 57.2% (i.e., 7.0, 16.2, and 42.8% TCE remaining) at OD(540)s of 2.0, 1.1, and 0.6, respectively. ODs also correlated linearly with zero-order degradation rates (1.99, 1.11, and 0.64 mumol h(-1)). While initial nonequilibrium mass losses of TCE produced only minor carbon isotope shifts (expressed in per mille delta C- 13(VPDB)), they were 57.2, 39.6, and 17.0parts per thousand between the initial and final TCE levels for the three experiments, in decreasing order of their OD(540)s. Despite these strong isotope shifts, we found a largely uniform isotope fractionation. The latter is expressed with a Rayleigh enrichment factor, E, and was -18.2 when all experiments were grouped to a common point of 42.8% TCE remaining. Although, decreases of epsilon to -20.7 were observed near complete degradation, our enrichment factors were significantly more negative than those reported for anaerobic dehalogenation of TCE. This indicates typical isotope fractionation for specific enzymatic mechanisms that can help to differentiate between degradation pathways
Preliminary study of thermomechanical fatigue of polycrystalline MAR-M 200
Thermomechanical fatigue (TMF) experiments were conducted on polycrystalline MAR-M 200 over a cyclic temperature range of 500 to 1000 C. Inelastic strain ranges of 0.03 to 0.2 percent were imposed on the specimens. The TMF lives were found to be significantly shorter than isothermal low-cycle-fatigue (LCF) life at the maximum cycle temperature, and in-phase cycling was more damaging than out-of-phase cycling. Extensive crack tip oxidation appeared to play a role in promoting the severity of in-phase cycling. Carbide particle - matrix interface cracking was also observed after in-phase TMF cycling. The applicability of various life prediction models to the TMF results obtained was assessed. It was concluded that current life prediction models based on isothermal data as input must be modified to be applicable to the TMF results
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