Opto-acoustic cell permeation (open access)

Opto-acoustic cell permeation

Optically generated acoustic waves have been used to temporarily permeate biological cells. This technique may be useful for enhancing transfection of DNA into cells or enhancing the absorption of locally delivered drugs. A diode-pumped frequency-doubled Nd:YAG laser operating at kHz repetition rates was used to produce a series of acoustic pulses. An acoustic wave was formed via thermoelastic expansion by depositing laser radiation into an absorbing dye. Generated pressures were measured with a PVDF hydrophone. The acoustic waves were transmitted to cultured and plated cells. The cell media contained a selection of normally- impermeable fluorescent-labeled dextran dyes. Following treatment with the opto-acoustic technique, cellular incorporation of dyes, up to 40,000 Molecular Weight, was noted. Control cells that did not receive opto-acoustic treatment had unremarkable dye incorporation. Uptake of dye was quantified via fluorescent microscopic analysis. Trypan Blue membrane exclusion assays and fluorescent labeling assays confirmed the vitality of cells following treatment. This method of enhanced drug delivery has the potential to dramatically reduce required drug dosages and associated side effects and enable revolutionary therapies.
Date: March 9, 2000
Creator: Visuri, S R & Heredia, N
Object Type: Article
System: The UNT Digital Library
Thermodynamics of paracrystalline silicon (open access)

Thermodynamics of paracrystalline silicon

Fluctuation microscopy experiments have shown that the as-deposited structure of amorphous silicon thin films is paracrystalline. A paracrystal consists of small (< 3 nm in diameter) topologically crystalline grains separated by a disordered matrix. Here the authors consider the thermodynamics of paracrystalline silicon as a function of the grain size and the temperature. They offer a simple model that qualitatively explains the observed metastability of the ordered structure at low temperature (300 K), the relaxation towards a more disordered structure at intermediate temperatures (600 K), and the recrystallization at high temperatures (1,000 K).
Date: May 9, 2000
Creator: Voyles, P. M.; Treacy, M. M. J. & Gibson, J. M.
Object Type: Article
System: The UNT Digital Library
MAXDOSE-SR: A routine release atmospheric dose model used at SRS (open access)

MAXDOSE-SR: A routine release atmospheric dose model used at SRS

MAXDOSE-SR is a PC version of the dosimetry code MAXIGASP, which was used to calculate doses to the maximally exposed offsite individual for routine atmospheric releases of radioactive material at the Savannah River Site (SRS). Complete code description, verification of models, and user's manual have been included in this report. Minimal input is required to run the program, and site specific parameters are used when possible.
Date: February 9, 2000
Creator: Simpkins, A.A.
Object Type: Report
System: The UNT Digital Library
U.S. field testing programs and results (open access)

U.S. field testing programs and results

The United States has been active in four major international in-situ or field testing programs over the past two decades, involving the burial of simulated high-level waste forms and package components. These programs are designed to supplement laboratory testing studies in order to obtain the most complete and realistic picture possible of waste glass behavior under realistic repository-relevant conditions.
Date: June 9, 2000
Creator: Wicks, G. G.
Object Type: Article
System: The UNT Digital Library
Pulse radiolysis studies in supercritical CO{sub 2} (open access)

Pulse radiolysis studies in supercritical CO{sub 2}

The pulse radiolysis technique has been applied to study reactions of ions in supercritical solutions. Evidence for the formation of C{sub 2}O{sub 4}{sup +} has been found in supercritical CO{sub 2}. The rate of the electron transfer reaction from dimethyl aniline to the C{sub 2}O{sub 4}{sup +} was measured over the density range of 0.17--0.7 g/cm{sup 3}. The reaction rate was measured to be close to diffusion-controlled at the lowest density; at higher densities, the rate was considerably below the apparent diffusion-controlled rate. Similar behavior was found for the reaction of the anion (presumably C{sub 2}O{sub 4}{sup {minus}}) with benzoquinone. The reaction of O{sub 2} with C{sub 2}O{sub 4}{sup +} was considerably slower than the expected diffusion-controlled rate.
Date: March 9, 2000
Creator: Jonah, C. D.; Dimitrijevic, N. M.; Bartels, D. M. & Takahashi, K.
Object Type: Article
System: The UNT Digital Library
Porosity in polysilsesquioxane xerogels (open access)

Porosity in polysilsesquioxane xerogels

Polysilsesquioxanes, [RSiO{sub 1.5}]{sub n} are a class of hybrid organic-inorganic materials in which silicon atoms are linked with up to three siloxane bonds to other monomer units in the polymer and the organic group is a pendent functionality. Polysilsesquioxanes are prepared by the hydrolysis and condensation of organotrialkoxysilanes (Scheme l). Organotrialkoxysilanes RSi(OR{prime}){sub 3}, have been extensively used as coupling agents for composites or surface treatments for materials. Polysilsesquioxanes have become increasingly popular for generating specialty coatings such as low k dielectric materials for microelectronic applications. While there is extensive information on the formation of polysilsesquioxanes, there has not been a survey of the ability of organotrialkoxysilanes to form gels until recently. The formation of polysilsesquioxanes gels has been shown to be very sensitive to the nature of the organic group. Many monomers will only form soluble oligomers or polymers upon hydrolysis and condensation, even when the reaction is conducted solvent-free with neat monomer and aqueous catalyst. Furthermore, there is little information concerning the influence of the organic group, R, on the porosity of the polysilsesquioxanes gels that are formed. In this paper the authors describe the preparation of polysilsesquioxane gels where R = H, methyl, ethyl, cyanoethyl, vinyl, dodecyl, hexadecyl, …
Date: May 9, 2000
Creator: Loy, Douglas A.; Schneider, Duane A.; Baugher, Brigitta M. & Rahimian, Kamyar
Object Type: Article
System: The UNT Digital Library
Degradation of EBR-II driver fuel during wet storage (open access)

Degradation of EBR-II driver fuel during wet storage

Characterization data are reported for sodium bonded EBR-II reactor fuel which had been stored underwater in containers since the 1981--1982 timeframe. Ten stainless steel storage containers, which had leaked water during storage due to improper sealing, were retrieved from the ICPP-603 storage basin at the Idaho National Engineering and Environmental Laboratory (INEEL) in Idaho. In the container chosen for detailed destructive analysis, the stainless steel cladding on the uranium alloy fuel had ruptured and fuel oxide sludge filled the bottom of the container. Headspace gas sampling determined that greater than 99% hydrogen was present. Cesium 137, which had leached out of the fuel during the aqueous corrosion process, dominated the radionuclide source term of the water. The metallic sodium from the fuel element bond had reacted with the water, forming a concentrated caustic solution of NaOH.
Date: March 9, 2000
Creator: Pahl, R. G.
Object Type: Article
System: The UNT Digital Library
Rare K+ Decays from Experiment E787 (open access)

Rare K+ Decays from Experiment E787

This paper presents the latest results from experiment E787, at Brookhaven National Laboratory, on K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} and radiative K{sup +} decays. The result for K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}} uses data collected in runs taken during 1995, 1996 and 1997. In addition, they discuss plans for future measurements of K{sup +} {r_arrow} {pi}{sup +} {nu}{bar {nu}}.
Date: October 9, 2000
Creator: Jain, V.
Object Type: Article
System: The UNT Digital Library
Microfabrication and Micropatterning with Soft Lithography (open access)

Microfabrication and Micropatterning with Soft Lithography

None
Date: August 9, 2000
Creator: Baca, Justin T. & Myers, Ramona L.
Object Type: Article
System: The UNT Digital Library
A new linear inductive voltage adder driver for the Saturn Accelerator (open access)

A new linear inductive voltage adder driver for the Saturn Accelerator

Saturn is a dual-purpose accelerator. It can be operated as a large-area flash x-ray source for simulation testing or as a Z-pinch driver especially for K-line x-ray production. In the first mode, the accelerator is fitted with three concentric-ring 2-MV electron diodes, while in the Z-pinch mode the current of all the modules is combined via a post-hole convolute arrangement and driven through a cylindrical array of very fine wires. We present here a point design for a new Saturn class driver based on a number of linear inductive voltage adders connected in parallel. A technology recently implemented at the Institute of High Current Electronics in Tomsk (Russia) is being utilized. In the present design we eliminate Marx generators and pulse-forming networks. Each inductive voltage adder cavity is directly fed by a number of fast 100-kV small-size capacitors arranged in a circular array around each accelerating gap. The number of capacitors connected in parallel to each cavity defines the total maximum current. By selecting low inductance switches, voltage pulses as short as 30-50-ns FWHM can be directly achieved. The voltage of each stage is low (100-200 kv). Many stages are required to achieve multi-megavolt accelerator output. However, since the length …
Date: August 9, 2000
Creator: Mazarakis, M. G.; Spielman, R. B.; Struve, K. W. & Long, F. W.
Object Type: Article
System: The UNT Digital Library
CARBON DIOXIDE AS A FEEDSTOCK. (open access)

CARBON DIOXIDE AS A FEEDSTOCK.

This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting …
Date: December 9, 2000
Creator: CREUTZ,C. & FUJITA,E.
Object Type: Article
System: The UNT Digital Library
DD Neutron Yield Measurements on Z Using Lead Probes (open access)

DD Neutron Yield Measurements on Z Using Lead Probes

A series of inertial confinement fusion (ICF) capsule experiments were run on the Z machine at Sandia's Pulsed Power directorate. These experiments were designed specifically to implode a 2 mm diameter hollow plastic capsule filled with deuterium gas. The implosion of the capsule should raise the temperature (kinetic energy) of the deuterium gas ions, which will interact with each other and produce 2.45 MeV fusion neutrons. The author is reporting on one diagnostic technique used to measure the yield of these fusion neutrons. The technique chosen to measure the DD neutron yield is the use of lead (Pb) probe detectors. The assignment was to calibrate two detectors for the 2.50-MeV neutrons produced by the deuterium-deuterium fusion reactions on Z. The author introduces ICF, and then describes the theory, the design, and the calibration of the lead probe. Finally, she presents the results of the ICF experiments and explain the difficulties inherent in analyzing the data.
Date: August 9, 2000
Creator: GERKEN,ERICA S.
Object Type: Article
System: The UNT Digital Library
Process Development for CIGS Based Thin Film Photovoltaics Modules, Phase II Technical Report (open access)

Process Development for CIGS Based Thin Film Photovoltaics Modules, Phase II Technical Report

As a technology partner with NREL, Global Solar Energy (GSE) has initiated an extensive and systematic plan to accelerate the commercialization of thin-film photovoltaics (PV) based on copper indium gallium diselenide (CIGS). The distinguishing feature of the GSE manufacturing process is the exclusive use of lightweight, flexible substrates. GSE has developed the technology to fabricate CIGS photovoltaics on both stainless-steel and polymer substrates. CIGS deposited on flexible substrates can be fabricated into either flexible or rigid modules. Low-cost, rigid PV panels for remote power, bulk/utility, telecommunication, and rooftop applications have been produced by affixing the flexible substrate to an inexpensive rigid panel by lamination or adhesive. Stainless-steel-based PV modules are fabricated by a novel interconnect method that avoids the use of wires or foils and soldered connections. In the case of polymer-based PV modules, the continuous roll is not sectioned into individual panels until the module buss and power leads are attached. Roll-to-roll vacuum deposition has several advantages that translate directly to reduced capital costs, greater productivity, improved yield, greater reliability, lower maintenance, and a larger volume of PV material. In combination with roll-to-roll processing, GSE has developed evaporation deposition operations that enable low-cost and high-efficiency CIGS modules. The CIGS …
Date: November 9, 2000
Creator: Britt, J.; Wiedeman, S. & Albright, S.
Object Type: Report
System: The UNT Digital Library
Enzymes for Degradation of Energetic Materials and Demilitarization of Explosives Stockpiles SERDP Final Report, 9/00 (open access)

Enzymes for Degradation of Energetic Materials and Demilitarization of Explosives Stockpiles SERDP Final Report, 9/00

None
Date: November 9, 2000
Creator: Goheen, SC; Campbell, JA; Shi, Y & Aust, S
Object Type: Report
System: The UNT Digital Library
Experience of Russian Radiochemical Plant Sites With the Bubbler Probe Manometry Tank Volume Measurement System. (open access)

Experience of Russian Radiochemical Plant Sites With the Bubbler Probe Manometry Tank Volume Measurement System.

None
Date: October 9, 2000
Creator: Suda, S.; Zuhoski, P.; Fishbone, L. G.; Darenskikh, O.; Purygin, V. & Golosovsky, A.
Object Type: Article
System: The UNT Digital Library
The Development of the Yucca Mountain Project Feature, Event, and Process (FEP) Database (open access)

The Development of the Yucca Mountain Project Feature, Event, and Process (FEP) Database

None
Date: November 9, 2000
Creator: FREEZE,GEOFF; SWIFT,PETER N. & BRODSKY,NANCY S.
Object Type: Article
System: The UNT Digital Library
CARBON DIOXIDE AS A FEEDSTOCK. (open access)

CARBON DIOXIDE AS A FEEDSTOCK.

This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting …
Date: December 9, 2000
Creator: CREUTZ,C. & FUJITA,E.
Object Type: Article
System: The UNT Digital Library
National Needs Drivers for Nanotechnology (open access)

National Needs Drivers for Nanotechnology

Societal needs related to demographics, resources, and human behavior will drive technological advances over the next 20 years. Nanotechnology is anticipated to be an important enabler of these advances, and thus maybe anticipated to have significant influence on new systems approaches to solving societal problems as well as on extending current science and technology-based applications. To examine the potential implications of nanotechnology a societal needs-driven approach is taken. Thus the methodology is to present the definition of the problem, and then examine system concepts, technology issues, and promising future directions. We approach the problem definition from a national and global security perspective and identify three key areas involving the condition of the planet, the human condition, and global security. In anticipating societal issues in the context of revolutionary technologies, such as maybe enabled by nanoscience, the importance of working on the entire life cycle of any technological solution is stressed.
Date: October 9, 2000
Creator: Yonas, G. & Picraux, S.T.
Object Type: Article
System: The UNT Digital Library
PRECOMBUSTION REMOVAL OF HAZARDOUS AIR POLLUTANT PRECURSORS (open access)

PRECOMBUSTION REMOVAL OF HAZARDOUS AIR POLLUTANT PRECURSORS

In response to growing environmental concerns reflected in the 1990 Clean Air Act Amendment (CAAA), the United States Department of Energy (DOE) sponsored several research and development projects in late 1995 as part of an initiative entitled Advanced Environmental Control Technologies for Coal-Based Power Systems. The program provided cost-shared support for research and development projects that could accelerate the commercialization of affordable, high-efficiency, low-emission, coal-fueled electric generating technologies. Clean coal technologies developed under this program would serve as prototypes for later generations of technologies to be implemented in the industrial sector. In order to identify technologies with the greatest potential for commercial implementation, projects funded under Phase I of this program were subject to competitive review by DOE before being considered for continuation funding under Phase II. One of the primary topical areas identified under the DOE initiative relates to the development of improved technologies for reducing the emissions of air toxics. Previous studies have suggested that many of the potentially hazardous air pollutant precursors (HAPPs) occur as trace elements in the mineral matter of run-of-mine coals. As a result, these elements have the potential to be removed prior to combustion at the mine site by physical coal cleaning processes …
Date: October 9, 2000
Creator: unknown
Object Type: Report
System: The UNT Digital Library
The Dynamic Competition Between Stress Generation and Relaxation Mechanisms During Coalescence of Volmer-Weber Thin Films (open access)

The Dynamic Competition Between Stress Generation and Relaxation Mechanisms During Coalescence of Volmer-Weber Thin Films

None
Date: October 9, 2000
Creator: Floro, J. A.; Hearne, S. J.; Hunter, J. A.; Kotula, P. G.; Chason, E.; Seel, S. C. et al.
Object Type: Article
System: The UNT Digital Library
New perspectives in physics beyond the standard model (open access)

New perspectives in physics beyond the standard model

In 1934 Fermi postulated a theory for weak interactions containing a dimensionful coupling with a size of roughly 250 GeV. Only now are we finally exploring this energy regime. What arises is an open question: supersymmetry and large extra dimensions are two possible scenarios. Meanwhile, other experiments will begin providing definitive information into the nature of neutrino masses and CP violation. In this paper, we explore features of possible theoretical scenarios, and study the phenomenological implications of various models addressing the open questions surrounding these issues.
Date: September 9, 2000
Creator: Weiner, Neal Jonathan
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Experimental Study of the Spin Structure of the Neutron (3He) at low Q2: a connection between the Bjorken and Gerasimov-Drell-Hearn Sum Rules (open access)

Experimental Study of the Spin Structure of the Neutron (3He) at low Q2: a connection between the Bjorken and Gerasimov-Drell-Hearn Sum Rules

The authors have presented the motivations in gathering doubly polarized data in the quasi-elastic, resonance and DIS domains. These data were used to calculate the extended GDH integral. The comparison of this quantity with the spin dependent forward Compton amplitude {bar S}{sub 1} is of particular importance for the unification of the two strong interaction descriptions (nucleonic/hadronic vs. partonic) because {bar S}{sub 1} is the first quantity theoretically calculable in the full Q{sup 2} domain of the strong interaction. Such a data taking was made possible because of three major technical achievements: (1) the beam of high duty cycle (100%), high current (up to 70 {micro}A) and high polarization (70%); (2) the {sup 3}He target of high density (above 10 atm) with a polarization of 35% and a length of 40 cm; and (3) the large acceptance (6 msr) and high resolution ({Delta}P/P {approx_equal} 10{sup {minus}4}) spectrometers. These features, available at Jefferson Lab, enabled them to achieve the highest luminosity in the world (about 10{sup 36} s{sup {minus}1} cm{sup {minus}2} with a current of 15 {micro}A) as far as polarized {sup 3}He targets are concerned. Consequently they were able to gather, in a rather short period of time (3 months), …
Date: October 9, 2000
Creator: Deur, Alexander
Object Type: Thesis or Dissertation
System: The UNT Digital Library
FEASIBILITY ANALYSIS FOR INSTALLING A CIRCULATING FLUIDIZED BED BOILER FOR COFIRING MULTIPLE BIOFUELS AND OTHER WASTES WITH COAL AT PENN STATE UNIVERSITY (open access)

FEASIBILITY ANALYSIS FOR INSTALLING A CIRCULATING FLUIDIZED BED BOILER FOR COFIRING MULTIPLE BIOFUELS AND OTHER WASTES WITH COAL AT PENN STATE UNIVERSITY

The Pennsylvania State University, under contract to the US Department of Energy, National Energy Technology Laboratory is performing a feasibility analysis on installing a state-of-the-art circulating fluidized bed boiler and ceramic filter emission control device at Penn State's University Park campus for cofiring multiple biofuels and other wastes with coal or coal refuse, and developing a test program to evaluate cofiring multiple biofuels and coal-based feedstocks. The objective of the project is being accomplished using a team that includes personnel from Penn State's Energy Institute and the Office of Physical Plant, Foster Wheeler Energy Corporation, Foster Wheeler Development Corporation, and Cofiring Alternatives. The major emphasis of work during this reporting period was to assess the types and quantities of potential feedstocks and collect samples of them for analysis. Approximately twenty different biomass, animal waste, and other wastes were collected and analyzed.
Date: October 9, 2000
Creator: Miller, Bruce G. & Jawdy, Curtis
Object Type: Report
System: The UNT Digital Library
Differencing Algorithms for Material Interfaces in Two-Phase Darcy Flow (open access)

Differencing Algorithms for Material Interfaces in Two-Phase Darcy Flow

None
Date: November 9, 2000
Creator: REED,ALFRED W.
Object Type: Article
System: The UNT Digital Library