Resource Type

Platinum Group Thiophenoxyimine Complexes: Syntheses,Crystallographic and Computational Studies of Structural Properties (open access)

Platinum Group Thiophenoxyimine Complexes: Syntheses,Crystallographic and Computational Studies of Structural Properties

Monomeric thiosalicylaldiminate complexes of rhodium(I) and iridium(I) were prepared by ligand transfer from the homoleptic zinc(II) species. In the presence of strongly donating ligands, the iridium complexes undergo insertion of the metal into the imine carbon-hydrogen bond. Thiophenoxyketimines were prepared by non-templated reaction of o-mercaptoacetophenone with anilines, and were complexed with rhodium(I), iridium(I), nickel(II) and platinum(II). X-ray crystallographic studies showed that while the thiosalicylaldiminate complexes display planar ligand conformations, those of the thiophenoxyketiminates are strongly distorted. Results of a computational study were consistent with a steric-strain interpretation of the difference in preferred ligand geometries.
Date: October 3, 2006
Creator: Krinsky, Jamin L.; Arnold, John & Bergman, Robert G.
System: The UNT Digital Library
Evidence for Anomalous Effects on the Current Evolution in Tokamak Operating Scenarios (open access)

Evidence for Anomalous Effects on the Current Evolution in Tokamak Operating Scenarios

Alternatives to the usual picture of advanced tokamak (AT) discharges are those that form when anomalous effects alter the plasma current and pressure profiles and those that achieve stationary characteristics through mechanisms so that a measure of desired AT features is maintained without external current-profile control. Regimes exhibiting these characteristics are those where the safety factor (q) evolves to a stationary profile with the on-axis and minimum q {approx} 1 and those with a deeply hollow current channel and high values of q. Operating scenarios with high fusion performance at low current and where the inductively driven current density achieves a stationary configuration with either small or non-existing sawteeth may enhance the neutron fluence per pulse on ITER and future burning plasmas. Hollow current profile discharges exhibit high confinement and a strong ''box-like'' internal transport barrier (ITB). We present results providing evidence for current profile formation and evolution exhibiting features consistent with anomalous effects or with self-organizing mechanisms. Determination of the underlying physical processes leading to these anomalous effects is important for scaling of current experiments for application in future burning plasmas.
Date: October 3, 2006
Creator: Casper, T.; Jayakumar, R.; Allen, S.; Holcomb, C.; Makowski, M.; Pearlstein, L. et al.
System: The UNT Digital Library
Gyrokinetic Simulations of ETG and ITG Turbulence (open access)

Gyrokinetic Simulations of ETG and ITG Turbulence

Published gyrokinetic continuum-code simulations indicated levels of the electron thermal conductivity {chi}{sub e} due to electron-temperature-gradient (ETG) turbulence large enough to be significant in some tokamaks, while subsequent global particle-in-cell (PIC) simulations gave significantly lower values. We have carried out an investigation of this discrepancy. We have reproduced the key features of the aforementioned PIC simulations using the flux-tube gyrokinetic PIC code, PG3EQ, thereby eliminating global effects and as the cause of the discrepancy. We show that the late-time low-transport state in both of these sets of PIC simulations is a result of discrete particle noise, which is a numerical artifact. Thus, the low value of {chi}{sub e} along with conclusions about anomalous transport drawn from these particular PIC simulations are unjustified. In our attempts to benchmark PIC and continuum codes for ETG turbulence at the plasma parameters used above, both produce very large intermittent transport. We have therefore undertaken benchmarks at an alternate reference point, magnetic shear s=0.1 instead of s=0.796, and have found that PIC and continuum codes reproduce the same transport levels. Scans in the magnetic shear show an abrupt transition to a high-{chi}{sub e} state as the shear is increased above s=0.4. When nonadiabatic ions are …
Date: October 3, 2006
Creator: Dimits, A.; Nevins, W.; Shumaker, D.; Hammett, G.; Dannert, T.; Jenko, F. et al.
System: The UNT Digital Library
PHEV Impacts on Regional Systems (Poster) (open access)

PHEV Impacts on Regional Systems (Poster)

This poster, submitted for the CU Energy Initiative/NREL Symposium on October 3, 2006 in Boulder, Colorado, looks at the impacts, emissions, and avoided gasoline due to plug-in hybrid electric vehicles (PHEVs).
Date: October 3, 2006
Creator: Parks, K.; Denholm, P. & Markel, T.
System: The UNT Digital Library
Best Practices in Determining the Impacts of Municipal Programs on Energy Use, Air Quality, and Other Ancillary Costs and Benefits (Poster) (open access)

Best Practices in Determining the Impacts of Municipal Programs on Energy Use, Air Quality, and Other Ancillary Costs and Benefits (Poster)

This poster, submitted for the CU Energy Initiative/NREL Symposium on October 3, 2006 held in Boulder, Colorado, discusses best practices for determining the impacts of municipal programs on energy use, air quality, and other costs and benefits.
Date: October 3, 2006
Creator: Brown, E. & Mosey, G.
System: The UNT Digital Library
Interaction Between Carbon Markets and Renewable Energy Markets (Poster) (open access)

Interaction Between Carbon Markets and Renewable Energy Markets (Poster)

This poster, submitted for the CU Energy Initiative/NREL Symposium on October 3, 2006 in Boulder, Colorado, discusses the interaction between carbon markets and renewable energy markets.
Date: October 3, 2006
Creator: Carroll, G. L.; Milford, J. & Bird, L.
System: The UNT Digital Library
Modeling of Performance, Cost, and Financing of Concentrating Solar, Photovoltaic, and Solar Heat Systems (Poster) (open access)

Modeling of Performance, Cost, and Financing of Concentrating Solar, Photovoltaic, and Solar Heat Systems (Poster)

This poster, submitted for the CU Energy Initiative/NREL Symposium on October 3, 2006 in Boulder, Colorado, discusses the modeling, performance, cost, and financing of concentrating solar, photovoltaic, and solar heat systems.
Date: October 3, 2006
Creator: Blair, N.; Mehos, M. & Christiansen, C.
System: The UNT Digital Library
Understanding Limitations in the Determination of the Diffuse Galactic Gamma-ray Emission (open access)

Understanding Limitations in the Determination of the Diffuse Galactic Gamma-ray Emission

We discuss uncertainties and possible sources of errors associated with the determination of the diffuse Galactic {gamma}-ray emission using the EGRET data. Most of the issues will be relevant also in the GLAST era. The focus here is on issues that impact evaluation of dark matter annihilation signals against the diffuse {gamma}-ray emission of the Milky Way.
Date: October 3, 2006
Creator: Moskalenko, Igor V.; /Stanford U., HEPL /KIPAC, Menlo Park; Digel, S.W.; /SLAC /KIPAC, Menlo Park; Porter, T.A.; /UC, Santa Cruz et al.
System: The UNT Digital Library
The MAPKERK-1,2 pathway integrates distinct and antagonistic signals from TGF alpha and FGF7 in morphogenesis of mouse mammary epithelium (open access)

The MAPKERK-1,2 pathway integrates distinct and antagonistic signals from TGF alpha and FGF7 in morphogenesis of mouse mammary epithelium

Transforming growth factor-{alpha} (TGF{alpha}) and fibroblast growth factor-7 (FGF7) exhibit distinct expression patterns in the mammary gland. Both factors signal through mitogen-activated kinase/extracellular regulated kinase-1,2 (MAPK{sup ERK1,2}); however, their unique and/or combined contributions to mammary morphogenesis have not been examined. In ex vivo mammary explants, we show that a sustained activation of MAPK{sup ERK1,2} for 1 h, induced by TGF{alpha}, was necessary and sufficient to initiate branching morphogenesis, whereas a transient activation (15 min) of MAPK{sup ERK1,2}, induced by FGF7, led to growth without branching. Unlike TGF{alpha}, FGF7 promoted sustained proliferation as well as ectopic localization of, and increase in, keratin-6 expressing cells. The response of the explants to FGF10 was similar to that to FGF7. Simultaneous stimulation by FGF7 and TGF{alpha} indicated that the FGF7-induced MAPK{sup ERK1,2} signaling and associated phenotypes were dominant: FGF7 may prevent branching by suppression of two necessary TGF{alpha}-induced morphogenetic effectors, matrix metalloproteinase-3 (MMP-3/stromelysin-1), and fibronectin. Our findings indicate that expression of morphogenetic effectors, proliferation, and cell-type decisions during mammary organoid morphogenesis are intimately dependent on the duration of activation of MAPK{sup ERK1,2} activation.
Date: October 3, 2006
Creator: Fata, Jimmie E; Mori, Hidetoshi; Ewald, Andrew J; Zhang, Hui; Yao, Evelyn; Werb, Zena et al.
System: The UNT Digital Library
Silicon Oxynitride Thin Film Barriers for PV Packaging (Poster) (open access)

Silicon Oxynitride Thin Film Barriers for PV Packaging (Poster)

Dielectric, adhesion-promoting, moisture barriers comprised of silicon oxynitride thin film materials (SiOxNy with various material stoichiometric compositions x,y) were applied to: 1) bare and pre-coated soda-lime silicate glass (coated with transparent conductive oxide SnO2:F and/or aluminum), and polymer substrates (polyethylene terephthalate, PET, or polyethylene napthalate, PEN); plus 2) pre- deposited photovoltaic (PV) cells and mini-modules consisting of amorphous silicon (a-Si) and copper indium gallium diselenide (CIGS) thin-film PV technologies. We used plasma enhanced chemical vapor deposition (PECVD) process with dilute silane, nitrogen, and nitrous oxide/oxygen gas mixtures in a low-power (< or = 10 milliW per cm2) RF discharge at ~ 0.2 Torr pressure, and low substrate temperatures < or = 100(degrees)C, over deposition areas ~ 1000 cm2. Barrier properties of the resulting PV cells and coated-glass packaging structures were studied with subsequent stressing in damp-heat exposure at 85(degrees)C/85% RH. Preliminary results on PV cells and coated glass indicate the palpable benefits of the barriers in mitigating moisture intrusion and degradation of the underlying structures using SiOxNy coatings with thicknesses in the range of 100-200 nm.
Date: October 3, 2006
Creator: del Cueto, J. A.; Glick, S. H.; Terwilliger, K. M.; Jorgensen, G. J.; Pankow, J. W.; Keyes, B. M. et al.
System: The UNT Digital Library
Impacts of Renewable Fuel and Electricity Standards on State Economies (Poster) (open access)

Impacts of Renewable Fuel and Electricity Standards on State Economies (Poster)

This poster, submitted for the CU Energy Initiative/NREL Symposium on October 3, discusses the impacts of renewable fuel and electricity standards on state economies.
Date: October 3, 2006
Creator: Brown, E.; Cory, K.; Brown, J.; Bird, L. & Sweezey, B.
System: The UNT Digital Library