Gas-Phase Molecular Dynamics: High Resolution Spectroscopy and Collision Dynamics of Transient Species (open access)

Gas-Phase Molecular Dynamics: High Resolution Spectroscopy and Collision Dynamics of Transient Species

This research is carried out as part of the Gas-Phase Molecular Dynamics program in the Chemistry Department at Brookhaven National Laboratory. Chemical intermediates in the elementary gas-phase reactions involved in combustion chemistry are investigated by high resolution spectroscopic tools. Production, reaction, and energy transfer processes are investigated by transient, double resonance, polarization and saturation spectroscopies, with an emphasis on technique development and connection with theory, as well as specific molecular properties.
Date: May 29, 2012
Creator: Hall, G. E. & Goncharov, V.
Object Type: Article
System: The UNT Digital Library
Control of New Kinetic Barriers & Design of Nanorods (open access)

Control of New Kinetic Barriers & Design of Nanorods

The accomplishments of this project include three elements. The first element directly relates to the focus of this project. Specifically, we have determined the three-dimensional Ehrlich-Schwoebel barriers, with and without surfactants, and two manuscripts in preparation; references refer to the list of journal publications. Further, we have discovered a characteristic length scale - the dimension of atomic islands bounded by multiple-layer surface steps. This discovery has made it possible to understand scientifically why nanorods synthesis is possible at all, will enable science-based design of nanorods, and may impact energy technology through nanomaterials design and synthesis. The second element relates to an exploration - synthesis of nanowires. This exploration is made possible through additional support of a Small Grant Exploratory Research from NSF. Through a combination of atomistic simulations, theories, and experiments, the PI and colleagues have made two contributions to the field. Specifically, they have revealed the physical reason why periodic twins develop during growth of SiC nanowires. Further, they have discovered that SiC nanowire films have an order-of-magnitude higher friction that their macroscopic counterpart, something that has never been reported before. The third elements relates to knowledge dissemination. The PI has co-edited (with Helena van Swygenhoven of PSI) an …
Date: May 29, 2012
Creator: Huang, Hanchen
Object Type: Report
System: The UNT Digital Library
Science Goals for the ARM Recovery Act Radars (open access)

Science Goals for the ARM Recovery Act Radars

Science Goals for the ARM Recovery Act Radars. In October 2008, an ARM workshop brought together approximately 30 climate research scientists to discuss the Atmospheric Radiation Measurement (ARM) Climate Research Facility's role in solving outstanding climate science issues. Through this discussion it was noted that one of ARM's primary contributions is to provide detailed information about cloud profiles and their impact on radiative fluxes. This work supports cloud parameterization development and improved understanding of cloud processes necessary for that development. A critical part of this work is measuring microphysical properties (cloud ice and liquid water content, cloud particle sizes, shapes, and distribution). ARM measurements and research have long included an emphasis on obtaining the best possible microphysical parameters with the available instrumentation. At the time of the workshop, this research was reaching the point where additional reduction in uncertainties in these critical parameters required new instrumentation for applications such as specifying radiative heating profiles, measuring vertical velocities, and studying the convective triggering and evolution of three-dimensional (3D) cloud fields. ARM was already operating a subset of the necessary instrumentation to make some progress on these problems; each of the ARM sites included (and still includes) a cloud radar (operating at …
Date: May 29, 2012
Creator: Mather, JH
Object Type: Text
System: The UNT Digital Library
Ceramic HEPA Filter Program (open access)

Ceramic HEPA Filter Program

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Date: May 29, 2012
Creator: Mitchell, M A; Bergman, W; Haslam, J; Brown, E P; Sawyer, S; Beaulieu, R et al.
Object Type: Article
System: The UNT Digital Library
Final Technical Report Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines (open access)

Final Technical Report Recovery Act: Online Nonintrusive Condition Monitoring and Fault Detection for Wind Turbines

The penetration of wind power has increased greatly over the last decade in the United States and across the world. The U.S. wind power industry installed 1,118 MW of new capacity in the first quarter of 2011 alone and entered the second quarter with another 5,600 MW under construction. By 2030, wind energy is expected to provide 20% of the U.S. electricity needs. As the number of wind turbines continues to grow, the need for effective condition monitoring and fault detection (CMFD) systems becomes increasingly important [3]. Online CMFD is an effective means of not only improving the reliability, capacity factor, and lifetime, but it also reduces the downtime, energy loss, and operation and maintenance (O&M) of wind turbines. The goal of this project is to develop novel online nonintrusive CMFD technologies for wind turbines. The proposed technologies use only the current measurements that have been used by the control and protection system of a wind turbine generator (WTG); no additional sensors or data acquisition devices are needed. Current signals are reliable and easily accessible from the ground without intruding on the wind turbine generators (WTGs) that are situated on high towers and installed in remote areas. Therefore, current-based CMFD …
Date: May 29, 2012
Creator: Qiao, Wei
Object Type: Report
System: The UNT Digital Library
LLNL-G3Dv3: global P-wave tomography model for improved regional and teleseismic travel time prediction (open access)

LLNL-G3Dv3: global P-wave tomography model for improved regional and teleseismic travel time prediction

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Date: May 29, 2012
Creator: Simmons, N A; Myers, S C; Johannesson, G & Matzel, E
Object Type: Article
System: The UNT Digital Library
NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN (open access)

NITRATE CONVERSION OF HB-LINE REILLEXTM HPQ RESIN

Reillex{trademark} HPQ ion exchange resin is used by HB Line to remove plutonium from aqueous streams. Reillex{trademark} HPQ resin currently available from Vertellus Specialties LLC is a chloride ionic form, which can cause stress corrosion cracking in stainless steels. Therefore, HB Line Engineering requested that Savannah River National Laboratory (SRNL) convert resin from chloride form to nitrate form in the Engineering Development Laboratory (EDL). To perform this task, SRNL treated two batches of resin in 2012. The first batch of resin from Reilly Industries Batch 80302MA was initially treated at SRNL in 2001 to remove chloride. This batch of resin, nominally 30 liters, has been stored wet in carboys since that time until being retreated in 2012. The second batch of resin from Batch 23408 consisted of 50 kg of new resin purchased from Vertellus Specialties in 2012. Both batches were treated in a column designed to convert resin using downflow of 1.0 M sodium nitrate solution through the resin bed followed by rinsing with deionized water. Both batches were analyzed for chloride concentration, before and after treatment, using Neutron Activation Analysis (NAA). The resin specification [Werling, 2003] states the total chlorine and chloride concentration shall be less than 250 …
Date: May 29, 2012
Creator: Steimke, J.; Williams, M.; Steeper, T. & Leishear, R.
Object Type: Report
System: The UNT Digital Library
Distinguishing Pu Metal From Pu Oxide Using Fast Neutron Counting (open access)

Distinguishing Pu Metal From Pu Oxide Using Fast Neutron Counting

We describe a method for simultaneously determining the {alpha}-ratio and k{sub eff} for fissile materials using fast neutrons. Our method is a generalization of the Hage-Cifarrelli method for determining k{sub eff} for fissile assemblies which utilizes the shape of the fast neutron spectrum. In this talk we illustrate the method using Monte Carlo simulations of the fast neutrons generated in PuO{sub 2} to calculate the fast neutron spectrum and Feynman correlations.
Date: May 29, 2012
Creator: Verbeke, J M; Chapline, G F; Nakae, L; Wurtz, R & Sheets, S
Object Type: Article
System: The UNT Digital Library
Surface and bulk current reduction of CdZnTe via band gap engineering (open access)

Surface and bulk current reduction of CdZnTe via band gap engineering

None
Date: May 29, 2012
Creator: Voss, Lars F.; Conway, Adam M.; Nelson, Art J.; Beck, Patrick R.; Graff, Robert T; Nikolic, Rebecca J et al.
Object Type: Article
System: The UNT Digital Library
Gas-Phase Molecular Dynamics: Theoretical Studies In Spectroscopy and Chemical Dynamics (open access)

Gas-Phase Molecular Dynamics: Theoretical Studies In Spectroscopy and Chemical Dynamics

The main goal of this program is the development and application of computational methods for studying chemical reaction dynamics and molecular spectroscopy in the gas phase. We are interested in developing rigorous quantum dynamics algorithms for small polyatomic systems and in implementing approximate approaches for complex ones. Particular focus is on the dynamics and kinetics of chemical reactions and on the rovibrational spectra of species involved in combustion processes. This research also explores the potential energy surfaces of these systems of interest using state-of-the-art quantum chemistry methods, and extends them to understand some important properties of materials in condensed phases and interstellar medium as well as in combustion environments.
Date: May 29, 2012
Creator: Yu, H. G. & Muckerman, J. T.
Object Type: Article
System: The UNT Digital Library