1,898 research outputs found
TSP2 Online Program Evaluation
This poster will report the results of a program evaluation for a new pilot online resource. The Study Place Project Online (TSP2 Online) is a personalized and confidential resource that aims to help students achieve their academic goals. The resource includes study tips, study locations, advice from professors, and a virtual study session. Students in psychology classes completed a brief online survey including a series of questions about the visuals and content of the pilot online resource. Final data collection and analyses will not be complete until early spring 2020, but preliminary findings suggest that TSP2 Online will be a valuable and effective academic resource.https://digitalcommons.cortland.edu/slides/1006/thumbnail.jp
Spin- and Isospin-Dependent Momentum Distributions in Fermi Liquids at Non-zero Temperatures
We explore the structure of momentum distributions of Fermi liquids such as
completely polarized 3He, unpolarized liquid 3He, and nuclear matter at nonzero
temperatures. The study employs correlated density matrix theory and adapts the
algorithm to deal with spin- and isospin-dependent correlations. The analysis
is based on the factor decomposition of the one-body reduced density matrix.
The decomposition permits to distinguish between statistical correlations and
dynamic (direct) correlations. Together with the concept of renormalized
fermions the formal results open the pathway to investigate the thermal
boundaries of normal Fermi phases within correlated density matrix theory. We
also discuss possible transitions from normal phases to anomalous fermion
phases triggered by statistical correlations or by periodic phase-phase
structures
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Evaluation of optical techniques for characterising soil organic matter quality in agricultural soils
Soil organic matter (SOM) is one of the main global carbon pools. It is a measure of soil quality as its presence increases carbon sequestration and improves physical and chemical soil properties. The determination and characterisation of humic substances gives essential information of the maturity and stresses of soils as well as of their health. However, the determination of the exact nature and molecular structure of these substances has been proven difficult. Several complex techniques exist to characterise SOM and mineralisation and humification processes. One of the more widely accepted for its accuracy is nuclear magnetic resonance (NMR) spectroscopy. Despite its efficacy, NMR needs significant economic resources, equipment, material and time. Proxy measures like the fluorescence index (FI), cold and hot-water extractable carbon (CWC and HWC) and SUVA-254 have the potential to characterise SOM and, in combination, provide qualitative and quantitative data of SOM and its processes. Spanish and British agricultural cambisols were used to measure SOM quality and determine whether similarities were found between optical techniques and 1H NMR results in these two regions with contrasting climatic conditions. High correlations (p < 0.001) were found between the specific aromatic fraction measured with 1H NMR and SUVA-254 (Rs = 0.95) and HWC (Rs = 0.90), which could be described using a linear model. A high correlation between FI and the aromatics fraction measured with 1H NMR (Rs = −0.976) was also observed. In view of our results, optical measures have a potential, in combination, to predict the aromatic fraction of SOM without the need of expensive and time consuming techniques
AlH3 between 65-110 GPa: implications of electronic band and phonon structures
A first-principles density-functional-theory method has been used to
reinvestigate the mechanical and dynamical stability of the metallic phase of
AlH3 between 65-110 GPa. The electronic properties and phonon dynamics as a
function of pressure are also explored. We find electron-phonon
superconductivity in the cubic Pm-3n structure with critical temperature Tc =
37 K at 70 GPa which decreases rapidly with the increase of pressure. Further
unlike a previously calculated Tc value of 24 K at 110 GPa, we do not find any
superconductivity of significance at this pressure which is consistent with
experimental observation.Comment: 6 pages, 4 figures Keywords: AlH3, Electronic structure, Phonon
dynamics, Superconductivity PACS number(s): 62.50.-p, 63.20.kd, 74.10.+v,
74.20.P
Observed photodetachment in parallel electric and magnetic fields
We investigate photodetachment from negative ions in a homogeneous 1.0-T
magnetic field and a parallel electric field of approximately 10 V/cm. A
theoretical model for detachment in combined fields is presented. Calculations
show that a field of 10 V/cm or more should considerably diminish the Landau
structure in the detachment cross section. The ions are produced and stored in
a Penning ion trap and illuminated by a single-mode dye laser. We present
preliminary results for detachment from S- showing qualitative agreement with
the model. Future directions of the work are also discussed.Comment: Nine pages, five figures, minor revisions showing final publicatio
STM characterization of the Si-P heterodimer
We use scanning tunneling microscopy (STM) and Auger electron spectroscopy to
study the behavior of adsorbed phosphine (PH) on Si(001), as a function
of annealing temperature, paying particular attention to the formation of the
Si-P heterodimer. Dosing the Si(001) surface with 0.002 Langmuirs of
PH results in the adsorption of PH (x=2,3) onto the surface and
some etching of Si to form individual Si ad-dimers. Annealing to 350C
results in the incorporation of P into the surface layer to form Si-P
heterodimers and the formation of short 1-dimensional Si dimer chains and
monohydrides. In filled state STM images, isolated Si-P heterodimers appear as
zig-zag features on the surface due to the static dimer buckling induced by the
heterodimer. In the presence of a moderate coverage of monohydrides this static
buckling is lifted, rending the Si-P heterodimers invisible in filled state
images. However, we find that we can image the heterodimer at all H coverages
using empty state imaging. The ability to identify single P atoms incorporated
into Si(001) will be invaluable in the development of nanoscale electronic
devices based on controlled atomic-scale doping of Si.Comment: 6 pages, 4 figures (only 72dpi
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An integrated building demolition and waste planning model for the Fernald Site
The Fernald DOE site will begin full-scale remediation of buildings under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) during the 1995 fiscal year pursuant to a signed Record of Decision. This effort is currently estimated to cost $350 million and span a minimum duration of 8 years, if funding is not a constraint. The identification of the most viable sequence and schedule for the effort involved the development of an integrated planning model and the commissioning of a sitewide planning team. The resulting work product represents the best combination of assumptions and calculations possible at this time and provides information necessary for compliance with the CERCLA Remedial Design documentation requirements for the over 230 component structures governed by the decision. Sequence and integrated schedule development for the decontamination and dismantlement (D&D) of Fernald structures has involved evaluation of current and future utilization of structures, availability of waste storage and staging space, the needs and impacts of other on-going Fernald projects, Resource Conservation and Recovery Act (RCRA) waste management and remediation projects, the layout of site utilities, site hydrology, and the potential sizing, location, and construction rates for an on-property disposal cell
Influence of temperature gradients on tunnel junction thermometry below 1 K: cooling and electron-phonon coupling
We have studied thermal gradients in thin Cu and AlMn wires, both
experimentally and theoretically. In the experiments, the wires were Joule
heated non-uniformly at sub-Kelvin temperatures, and the resulting temperature
gradients were measured using normal metal-insulator-superconducting tunnel
junctions. The data clearly shows that even in reasonably well conducting thin
wires with a short (m) non-heated portion, significant temperature
differences can form. In most cases, the measurements agree well with a model
which includes electron-phonon interaction and electronic thermal conductivity
by the Wiedemann-Franz law.Comment: J. Low Temp. Phys. in pres
Isoscalar Giant Dipole Resonance and Nuclear Matter Incompressibility Coefficient
We present results of microscopic calculations of the strength function,
S(E), and alpha-particle excitation cross sections sigma(E) for the isoscalar
giant dipole resonance (ISGDR). An accurate and a general method to eliminate
the contributions of spurious state mixing is presented and used in the
calculations. Our results provide a resolution to the long standing problem
that the nuclear matter incompressibility coefficient, K, deduced from sigma(E)
data for the ISGDR is significantly smaller than that deduced from data for the
isoscalar giant monopole resonance (ISGMR).Comment: 4 pages using revtex 3.0, 3 postscript figures created by Mathematica
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