Resource Type

The ACTive Intervention in Hospice Interdisciplinary Team Meetings: Exploring family caregiver and hospice team communication (open access)

The ACTive Intervention in Hospice Interdisciplinary Team Meetings: Exploring family caregiver and hospice team communication

Article describing family caregiver and hospice team communication and the ACTive intervention in hospice interdisciplinary team meetings.
Date: April 14, 2010
Creator: Wittenberg-Lyles, Elaine; Oliver, Debra Parker; Demiris, George & Baldwin, Paula K.
System: The UNT Digital Library
Disclosure of Children's Positive Serostatus to Family and Nonfamily Members: Informal Caregivers in Togo, West Africa (open access)

Disclosure of Children's Positive Serostatus to Family and Nonfamily Members: Informal Caregivers in Togo, West Africa

Article on the disclosure of children's positive serostatus to family and nonfamily members.
Date: April 14, 2011
Creator: Moore, Ami R. & Williamson, David Allen
System: The UNT Digital Library
Experimental and Computational Studies of the Kinetics of the Reaction of Atomic Hydrogen with Methanethiol (open access)

Experimental and Computational Studies of the Kinetics of the Reaction of Atomic Hydrogen with Methanethiol

Article on experimental and computational studies of the kinetics of the reaction of atomic hydrogen with methanethiol.
Date: April 14, 2015
Creator: Kerr, Katherine E.; Alecu, I. M.; Thompson, Kristopher; Gao, Yide & Marshall, Paul
System: The UNT Digital Library
EXPERIMENTS ON CAKE DEVELOPMENT IN CROSSFLOW FILTRATION FOR HIGH LEVEL WASTE (open access)

EXPERIMENTS ON CAKE DEVELOPMENT IN CROSSFLOW FILTRATION FOR HIGH LEVEL WASTE

Crossflow filtration is a key process step in many operating and planned waste treatment facilities to separate undissolved solids from supernate slurries. This separation technology generally has the advantage of self cleaning through the action of wall shear stress, which is created by the flow of waste slurry through the filter tubes. However, the ability of filter wall self cleaning depends on the slurry being filtered. Many of the alkaline radioactive wastes are extremely challenging to filtration, e.g., those containing compounds of aluminum and iron, which have particles whose size and morphology reduces permeability. Low filter flux can be a bottleneck in waste processing facilities such as the Salt Waste Processing Facility at the Savannah River Site and the Waste Treatment Plant at the Hanford Site. Any improvement to the filtration rate would lead directly to increased throughput of the entire process. To date, increased rates are generally realized by either increasing the crossflow filter axial flowrate, which is limited by pump capacity, or by increasing filter surface area, which is limited by space and increases the required pump load. In the interest of accelerating waste treatment processing, DOE has funded studies to better understand filtration with the goal of …
Date: April 14, 2011
Creator: Duignan, M. & Nash, C.
System: The UNT Digital Library
Nanopillars array for surface enhanced Raman scattering (open access)

Nanopillars array for surface enhanced Raman scattering

The authors present a new class of surface-enhanced Raman scattering (SERS) substrates based on lithographically-defined two-dimensional rectangular array of nanopillars. Two types of nanopillars within this class are discussed: vertical pillars and tapered pillars. For the vertical pillars, the gap between each pair of nanopillars is small enough (< 50 nm) such that highly confined plasmonic cavity resonances are supported between the pillars when light is incident upon them, and the anti-nodes of these resonances act as three-dimensional hotspots for SERS. For the tapered pillars, SERS enhancement arises from the nanofocusing effect due to the sharp tip on top. SERS experiments were carried out on these substrates using various concentrations of 1,2 bis-(4-pyridyl)-ethylene (BPE), benzenethiol (BT) monolayer and toluene vapor. The results show that SERS enhancement factor of over 0.5 x 10{sup 9} can be achieved, and BPE can be detected down to femto-molar concentration level. The results also show promising potential for the use of these substrates in environmental monitoring of gases and vapors such as volatile organic compounds.
Date: April 14, 2011
Creator: Chang, A. S. P.; Bora, M.; Nguyen, H. T.; Behymer, E. M.; Larson, C. C.; Britten, J. A. et al.
System: The UNT Digital Library
Optical method for distance and displacement measurements of the probe-sample separation in a scanning near-field optical microscope (open access)

Optical method for distance and displacement measurements of the probe-sample separation in a scanning near-field optical microscope

This article presents an alternative optical method to determine the probe-sample separation distance in a scanning near-field optical microscope.
Date: May 18, 2016
Creator: Santamaria, L.; Garcia-Ortiz, C. E.; Siller Carrillo, Héctor Rafael; Cortes, R. & Coello, V.
System: The UNT Digital Library
Physicians, Clinics, and Neighborhoods: Multiple Levels of Influence on Colorectal Cancer Screening (open access)

Physicians, Clinics, and Neighborhoods: Multiple Levels of Influence on Colorectal Cancer Screening

This article describes variability in colorectal cancer (CRC) test use and compares the performance of novel cross-classified and traditional hierarchical models.
Date: April 14, 2014
Creator: Pruitt, Sandi L.; Leonard, Tammy; Zhang, Song; Schootman, Mario; Halm, Ethan A. & Gupta, Samir
System: The UNT Digital Library
Simple Fully Automated Group Classification on Brain fMRI (open access)

Simple Fully Automated Group Classification on Brain fMRI

We propose a simple, well grounded classification technique which is suited for group classification on brain fMRI data sets that have high dimensionality, small number of subjects, high noise level, high subject variability, imperfect registration and capture subtle cognitive effects. We propose threshold-split region as a new feature selection method and majority voteas the classification technique. Our method does not require a predefined set of regions of interest. We use average acros ssessions, only one feature perexperimental condition, feature independence assumption, and simple classifiers. The seeming counter-intuitive approach of using a simple design is supported by signal processing and statistical theory. Experimental results in two block design data sets that capture brain function under distinct monetary rewards for cocaine addicted and control subjects, show that our method exhibits increased generalization accuracy compared to commonly used feature selection and classification techniques.
Date: April 14, 2010
Creator: Honorio, J.; Goldstein, R.; Honorio, J.; Samaras, D.; Tomasi, D. & Goldstein, R.Z.
System: The UNT Digital Library
System Modeling of kJ-class Petawatt Lasers at LLNL (open access)

System Modeling of kJ-class Petawatt Lasers at LLNL

Advanced Radiographic Capability (ARC) project at the National Ignition Facility (NIF) is designed to produce energetic, ultrafast x-rays in the range of 70-100 keV for backlighting NIF targets. The chirped pulse amplification (CPA) laser system will deliver kilo-Joule pulses at an adjustable pulse duration from 1 ps to 50 ps. System complexity requires sophisticated simulation and modeling tools for design, performance prediction, and comprehension of experimental results. We provide a brief overview of ARC, present our main modeling tools, and describe important performance predictions. The laser system (Fig. 1) consists of an all-fiber front end, including chirped-fiber Bragg grating (CFBG) stretchers. The beam after the final fiber amplifier is split into two apertures and spatially shaped. The split beam first seeds a regenerative amplifier and is then amplified in a multi-pass Nd:glass amplifier. Next, the preamplified chirped pulse is split in time into four identical replicas and injected into one NIF Quad. At the output of the NIF beamline, each of the eight amplified pulses is compressed in an individual, folded, four-grating compressor. Compressor grating pairs have slightly different groove densities to enable compact folding geometry and eliminate adjacent beam cross-talk. Pulse duration is adjustable with a small, rack-mounted compressor …
Date: April 14, 2010
Creator: Shverdin, M Y; Rushford, M; Henesian, M A; Boley, C; Haefner, C; Heebner, J E et al.
System: The UNT Digital Library
Theoretical study of transverse-longitudinal emittance coupling (open access)

Theoretical study of transverse-longitudinal emittance coupling

The effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions is investigated using the generalized Courant-Snyder theory for coupled lattices. Recently, the concept and technique of transverse-longitudinal emittance coupling have been proposed for applications in the Linac Coherent Light Source and other free-electron lasers to reduce the transverse emittance of the electron beam. Such techniques can also be applied to the driver beams for the heavy ion fusion and beam-driven high energy density physics, where the transverse emittance budget is typically tighter than the longitudinal emittance. The proposed methods consist of one or several coupling components which completely swap the emittances of one of the transverse directions and the longitudinal direction at the exit of the coupling components. The complete emittance exchange is realized in one pass through the coupling components. In the present study, we investigate the effect of a weakly coupled periodic lattice in terms of achieving emittance exchange between the transverse and longitudinal directions. A weak coupling component is introduced at every focusing lattice, and we would like to determine if such a lattice can realize the function of emittance exchange.
Date: April 14, 2011
Creator: Qin, H.; Davidson, R. C.; Chung, M.; Barnard, J. J. & Wang, T. F.
System: The UNT Digital Library
Thick beryllium coatings by magnetron sputtering (open access)

Thick beryllium coatings by magnetron sputtering

Thick (>150 {micro}m) beryllium coatings are studied as an ablator material of interest for fusion fuel capsules for the National Ignition Facility (NIF). As an added complication, the coatings are deposited on mm-scale spherical substrates, as opposed to flats. DC magnetron sputtering is used because of the relative controllability of the processing temperature and energy of the deposits. We used ultra small angle x-ray spectroscopy (USAXS) to characterize the void fraction and distribution along the spherical surface. We investigated the void structure using a combination focused ion beam (FIB) and scanning electron microscope (SEM), along with transmission electron microscopy (TEM). Our results show a few volume percent of voids and a typical void diameter of less than two hundred nanometers. Understanding how the stresses in the deposited material develop with thickness is important so that we can minimize film cracking and delamination. To that end, an in-situ multiple optical beam stress sensor (MOSS) was used to measure the stress behavior of thick Beryllium coatings on flat substrates as the material was being deposited. We will show how the film stress saturates with thickness and changes with pressure.
Date: April 14, 2011
Creator: Wu, H.; Nikroo, A.; Youngblood, K.; Moreno, K.; Wu, D.; Fuller, T. et al.
System: The UNT Digital Library
Waveguide Coupling via Magnetic Gratings with Effective Strips (open access)

Waveguide Coupling via Magnetic Gratings with Effective Strips

This article provides an overview of an approach convenient for describing intermediate gratings for two types of applications: both metafilms and the coupling of incident waves to waveguide modes or diffraction orders.
Date: April 14, 2018
Creator: Roccapriore, Kevin M.; Lyvers, David P.; Brown, Dean P.; Poutrina, Ekaterina; Urbas, Augustine M.; Germer, Thomas A. et al.
System: The UNT Digital Library