Measurement of Ultra Low Outgassing Rates for NLC UHV Vacuum Chambers (open access)

Measurement of Ultra Low Outgassing Rates for NLC UHV Vacuum Chambers

Ultra low outgassing rates would be highly advantageous in accelerators and storage rings, such as the Next Linear Collider (NLC), where an outgassing rate of <10{sup -12} Torr liter/sec/cm{sup 2} could eliminate the need for costly distributed pumping. Measuring such low outgassing rates at room temperature has many difficulties. However, by inspection of Fick's law, it can be seen that thermal desorption is proportional to outgassing rate. It is commonly observed that the outgas rate doubles approximately every 15 C for temperatures under 100 C. By measuring outgassing rate versus temperature and time and extrapolating back to room temperature we can measure outgassing rates that would otherwise be difficult to make. To produce a reliable measurement also requires the total surface area under study to be approximately an order of magnitude greater than the area of the measurement chamber walls. To accomplish this, 27 plates of 5083 aluminum were placed in the measurement chamber. This technique will be the basis for future investigation of outgassing rates of other sample plates fabricated with different machining and cleaning techniques.
Date: June 12, 2001
Creator: Kishiyama, K.; Shen, S.; Behne, D.; Corlett, J. N.; Atkinson, D.; Kennedy, K. et al.
Object Type: Article
System: The UNT Digital Library
What is a Shock Wave to an Explosive Molecule? (open access)

What is a Shock Wave to an Explosive Molecule?

An explosive molecule is a metastable chemical species that reacts exothermically given the correct stimulus. Impacting an explosive with a shock wave is a ''wake-up call'' or ''trigger'' which compresses and heats the molecule. The energy deposited by the shock wave must be distributed to the vibrational modes of the explosive molecule before chemical reaction can occur. If the shock pressure and temperature are high enough and last long enough, exothermic chemical decomposition can lead to the formation of a detonation wave. For gaseous, liquid, and perfect single crystal solid explosives, after an induction time, chemical reaction begins at or near the rear boundary of the charge. This induction time can be calculated by high pressure, high temperature transition state theory. A ''superdetonation'' wave travels through the preshocked explosive until it overtakes the initial shock wave and then slows to the steady state Chapman-Jouguet (C-J) velocity. In heterogeneous solid explosives, initiation of reaction occurs at ''hot spots'' created by shock compression. If there is a sufficient number of large and hot enough ''hot spots,'' these ignition sites grow creating a pressure pulse that overtakes the leading shock front causing detonation. Since the chemical energy is released well behind the leading …
Date: June 12, 2001
Creator: Tarver, Craig M.
Object Type: Article
System: The UNT Digital Library
Gamma-gamma interaction region design issues (open access)

Gamma-gamma interaction region design issues

An initial design of the optics required for producing gamma-gamma collisions was produced for the NLC Zeroth Order Design Report (ZDR) submitted to the 1996 Snowmass workshop. The design incorporated only loose constraints from the interaction region requirements. In this paper we report progress on a design of a gamma-gamma interaction region which incorporates all constraints.
Date: January 12, 2001
Creator: Gronberg, J
Object Type: Article
System: The UNT Digital Library
Designing Remote Monitoring Systems for Long Term Maintenance and Reliability (open access)

Designing Remote Monitoring Systems for Long Term Maintenance and Reliability

As part of the effort to modernize safeguards equipment, the IAEA is continuing to acquire and install equipment for upgrading obsolete surveillance systems with digital technology; and providing remote-monitoring capabilities where and when economically justified. Remote monitoring is expected to reduce inspection effort, particularly at storage facilities and reactor sites. Remote monitoring technology will not only involve surveillance, but will also include seals, sensors, and other unattended measurement equipment. The experience of Lawrence Livermore National Laboratory (LLNL) with the Argus Security System offers lessons for the design, deployment, and maintenance of remote monitoring systems. Argus is an integrated security system for protection of high-consequence U.S. Government assets, including nuclear materials. Argus provides secure transmission of sensor data, administrative data, and video information to support intrusion detection and access control functions. LLNL developed and deployed the Argus system on its own site in 1988. Since that time LLNL has installed, maintained, and upgraded Argus systems at several Department of Energy and Department of Defense sites in the U.S. and at the original LLNL site. Argus has provided high levels of reliability and integrity, and reduced overall life-cycle cost through incremental improvements to hardware and software. This philosophy permits expansion of functional …
Date: October 12, 2001
Creator: Davis, G E; Johnson, G L; Schrader, F D; Stone, M A & Wilson, E F
Object Type: Article
System: The UNT Digital Library
BBU and Corkscrew Growth Predictions for the DARHT Second Axis Accelerator (open access)

BBU and Corkscrew Growth Predictions for the DARHT Second Axis Accelerator

The second axis accelerator of the Dual Axis Radiographic Hydrodynamic Test (DARHT-II) facility will produce a 2-kA, 20-MeV, 2-{micro}s output electron beam with a design goal of less than 1000 {pi} mm-mrad normalized transverse emittance. In order to meet this goal, both the beam breakup instability (BBU) and transverse ''corkscrew'' motion (due to chromatic phase advance) must be limited in growth. Using data from recent experimental measurements of the transverse impedance of actual DARHT-II accelerator cells by Briggs et al., they have used the LLNL BREAKUP code to predict BBU and corkscrew growth in DARHT-II. The results suggest that BBU growth should not seriously degrade the final achievable spot size at the x-ray converter, presuming the initial excitation level is of the order 100 microns or smaller. For control of corkscrew growth, a major concern is the number of ''tuning'' shots needed to utilize effectively the ''tuning-V'' algorithm. Presuming that the solenoid magnet alignment falls within spec, they believe that possibly as few as 50-100 shots will be necessary to set the dipole corrector magnet currents. They give some specific examples of tune determination for a hypothetical set of alignment errors.
Date: June 12, 2001
Creator: Chen, Y. J. & Fawley, W. M.
Object Type: Article
System: The UNT Digital Library
Explosion in the Granite Field: Hardening and Softening Behavior in Rocks (open access)

Explosion in the Granite Field: Hardening and Softening Behavior in Rocks

Properties of rock materials under quasistatic conditions are well characterized in laboratory experiments. Unfortunately, quasistatic data alone are not sufficient to calibrate models for use to describe inelastic wave propagation associated with conventional and nuclear explosions, or with impact. First, rock properties are size-dependent. properties measured using laboratory samples on the order of a few centimeters in size need to be modified to adequately describe wave propagation in a problem on the order of a few hundred meters in size. Second, there is lack of data about the damage (softening) behavior of rock because most laboratory tests focus on the pre-peak hardening region with very little emphasis on the post-peak softening region. This paper presents a model for granite that accounts for both the hardening and softening of geologic materials, and also provides a simple description of rubblized rock. The model is shown to reproduce results of quasistatic triaxial experiments as well as peak velocity and peak displacement attenuation from a compendium of dynamic wave propagation experiments that includes US and French nuclear tests in granite.
Date: July 12, 2001
Creator: Lomov, I N; Antoun, T H & Glenn, L A
Object Type: Article
System: The UNT Digital Library
Properties of fiber composites for advanced flywheel energy storage devices (open access)

Properties of fiber composites for advanced flywheel energy storage devices

The performance of commercial high-performance fibers is examined for application to flywheel power supplies. It is shown that actual delivered performance depends on multiple factors such as inherent fiber strength, strength translation and stress-rupture lifetime. Experimental results for recent stress-rupture studies of carbon fibers will be presented and compared with other candidate reinforcement materials. Based on an evaluation of all of the performance factors, it is concluded that carbon fibers are preferred for highest performance and E-glass fibers for lowest cost. The inferior performance of the low-cost E-glass fibers can be improved to some extent by retarding the stress-corrosion of the material due to moisture and practical approaches to mitigating this corrosion are discussed. Many flywheel designs are limited not by fiber failure, but by matrix-dominated failure modes. Unfortunately, very few experimental results for stress-rupture under transverse tensile loading are available. As a consequence, significant efforts are made in flywheel design to avoid generating any transverse tensile stresses. Recent results for stress-rupture of a carbon fiber/epoxy composite under transverse tensile load reveal that these materials are surprisingly durable under the transverse loading condition and that some radial tensile stress could be tolerated in flywheel applications.
Date: January 12, 2001
Creator: DeTeresa, S J & Groves, S E
Object Type: Article
System: The UNT Digital Library
Operation of a Four-Cylinder 1.9L Propane Fueled Homogeneous Charge Compression Ignition Engine: Basic Operating Characteristics and Cylinder-to-Cylinder Effects (open access)

Operation of a Four-Cylinder 1.9L Propane Fueled Homogeneous Charge Compression Ignition Engine: Basic Operating Characteristics and Cylinder-to-Cylinder Effects

A four-cylinder 1.9 Volkswagen TDI Engine has been converted to run in Homogeneous Charge Compression Ignition (HCCI) mode. The stock configuration is a turbocharged direct injection Diesel engine. The combustion chamber has been modified by discarding the in-cylinder Diesel fuel injectors and replacing them with blank inserts (which contain pressure transducers). The stock pistons contain a reentrant bowl and have been retained for the tests reported here. The intake and exhaust manifolds have also been retained, but the turbocharger has been removed. A heater has been installed upstream of the intake manifold and fuel is added just downstream of this heater. The performance of this engine in naturally aspirated HCCI operation, subject to variable intake temperature and fuel flow rate, has been studied. The engine has been run with propane fuel at a constant speed of 1800 rpm. This work is intended to characterize the HCCI operation of the engine in this configuration that has been minimally modified from the base Diesel engine. The performance (BMEP, IMEP, efficiency, etc) and emissions (THC, CO, NOx) of the engine are presented, as are combustion process results based on heat release analysis of the pressure traces from each cylinder.
Date: March 12, 2001
Creator: Flowers, D.; Aceves, S. M.; Martinez-Frias, J.; Smith, J. R.; Au, M.; Girard, J. et al.
Object Type: Article
System: The UNT Digital Library
Modeling of an Inductive Adder Kicker Pulser for a Proton Radiography System (open access)

Modeling of an Inductive Adder Kicker Pulser for a Proton Radiography System

An all solid-state kicker pulser for a proton radiography system has been designed. Multiple solid-state modulators stacked in an inductive-adder configuration are utilized in this kicker pulser design. Each modulator is comprised of multiple metal-oxide-semiconductor field-effect transistors (MOSFETs) which quickly switch the energy storage capacitors across a magnetic induction core. Metglas is used as the core material to minimize loss. Voltage from each modulator is inductively added by a voltage summing stalk. A circuit model of a prototype inductive adder kicker pulser modulator has been developed to predict the performance of the pulser modulator. The modeling results are compared with experimental data.
Date: June 12, 2001
Creator: Wang, L.; Caporaso, G. J. & Cook, E. G.
Object Type: Article
System: The UNT Digital Library
The plasticity of human breast carcinoma cells is more than epithelial to mesenchymal conversion (open access)

The plasticity of human breast carcinoma cells is more than epithelial to mesenchymal conversion

The human breast comprises three lineages: the luminal epithelial lineage, the myoepithelial lineage, and the mesenchymal lineage. It has been widely accepted that human breast neoplasia pertains only to the luminal epithelial lineage. In recent years, however, evidence has accumulated that neoplastic breast epithelial cells may be substantially more plastic in their differentiation repertoire than previously anticipated. Thus, along with an increasing availability of markers for the myoepithelial lineage, at least a partial differentiation towards this lineage is being revealed frequently. It has also become clear that conversions towards the mesenchymal lineage actually occur, referred to as epithelial to mesenchymal transitions. Indeed, some of the so-called myofibroblasts surrounding the tumor may indeed have an epithelial origin rather than a mesenchymal origin. Because myoepithelial cells, epithelial to mesenchymal transition-derived cells, genuine stromal cells and myofibroblasts share common markers, we now need to define a more ambitious set of markers to distinguish these cell types in the microenvironment of the tumors. This is necessary because the different microenvironments may confer different clinical outcomes. The aim of this commentary is to describe some of the inherent complexities in defining cellular phenotypes in the microenvironment of breast cancer and to expand wherever possible on …
Date: May 12, 2001
Creator: Petersen, Ole William; Nielsen, Helga Lind; Gudjonsson, Thorarinn; Villadsen, René Ronnov-Jessen, Lone & Bissell, Mina J.
Object Type: Article
System: The UNT Digital Library
Results of Tritium Tracking and Groundwater Monitoring at the Hanford Site 200 Area State-Approved Land Disposal Site--Fiscal Year 2001 (open access)

Results of Tritium Tracking and Groundwater Monitoring at the Hanford Site 200 Area State-Approved Land Disposal Site--Fiscal Year 2001

The Hanford Site 200 Area Effluent Treatment Facility (ETF) processes contaminated liquids derived from Hanford Site facilities. The clean water generated by these processes is occasionally enriched in tritium, and is discharged to the 200 Area State Approved Land Disposal Site (SALDS). Groundwater monitoring for tritium and other constituents is required by the state-issued permit at 22 wells surrounding the facility. During FY 2001, tritium activities in the SALDS proximal well 699-48-77A increased (maximum 670,000 pCi/L) as a result of the resumption of tritium disposal in September 2000, following a 16-month hiatus in significant tritium discharges. Well 699-48-77C, where tritium results reached a maximum value of 980,000 pCi/L, is reflecting the result of the delayed penetration of effluent deeper into the aquifer from 1999 SALDS tritium discharges. Speculation in FY 2000 (Barnett 2000b) that tritium may have reached two wells due south of the facility is probably premature. FY 2001 results indicate no departures from historical levels of tritium in these wells.
Date: October 12, 2001
Creator: Barnett, D. Brent & Rieger, Joanne T.
Object Type: Report
System: The UNT Digital Library
Material Balance Assessment for Double-Shell Tank Waste Pipeline Transfer (open access)

Material Balance Assessment for Double-Shell Tank Waste Pipeline Transfer

PNNL developed a material balance assessment methodology based on conservation of mass for detecting leaks and mis-routings in pipeline transfer of double-shell tank waste at Hanford. The main factors causing uncertainty in these transfers are variable property and tank conditions of density, existence of crust, and surface disturbance due to mixer pump operation during the waste transfer. The methodology was applied to three waste transfers from Tanks AN-105 and AZ-102.
Date: March 12, 2001
Creator: Onishi, Yasuo; Wells, Beric E.; Hartley, Stacey A. & Enderlin, Carl W.
Object Type: Report
System: The UNT Digital Library
Determining benefits and costs of improved central air conditioner efficiencies (open access)

Determining benefits and costs of improved central air conditioner efficiencies

Economic impacts on individual consumers from possible revisions to U.S. residential-type central air conditioner energy-efficiency standards are examined using a life-cycle cost (LCC) analysis. LCC is the consumer's cost of purchasing and installing a central air conditioner and operating it over its lifetime. This approach makes it possible to evaluate the economic impacts on individual consumers from the revised standards. The methodology allows an examination of groups of the population which benefit or lose from suggested efficiency standards. The results show that the economic benefits to consumers due to modest increases in efficiency are significant. For an efficiency increase of 20percent over the existing minimum standard (i.e., 12 SEER), 35percent of households with central air conditioners experience significant LCC savings, with an average savings of $453, while 25percent show significant LCC losses, with an average loss of $158 compared to apre-standard LCC average of $5,170. The remainder of the population (40percent) are largely unaffected.
Date: January 12, 2001
Creator: Rosenquist, G.; Levok, A.; Chan, P. & McMahon, J.
Object Type: Article
System: The UNT Digital Library
Very extended shapes in the A~;110 region (open access)

Very extended shapes in the A~;110 region

High-angular-momentum states in {sup 108}Cd were populated via the {sup 64}Ni({sup 48}Ca,4n) reaction at a beam energy of 207 MeV. Gamma rays were detected using the Gammasphere array. A rotational band has been observed with a dynamic moment of inertia and deduced lower limit of the quadrupole moment suggesting a major-to-minor axis ratio larger than 1.8:1, placing it among the most deformed structures identified in any nucleus, to date.
Date: September 12, 2001
Creator: Clark, R. M.; Fallon, P.; Gorgen, A.; Cromaz, M.; Deleplanque, M. A.; Diamond, R. M. et al.
Object Type: Article
System: The UNT Digital Library
On the handling of atomic anisotropic displacement parameters (open access)

On the handling of atomic anisotropic displacement parameters

None
Date: November 12, 2001
Creator: Grosse-Kunstleve, Ralf W. & Adams, Paul D.
Object Type: Article
System: The UNT Digital Library
External Criticality Risk of Immobilized Plutonium Waste Form in a Geologic Repository (open access)

External Criticality Risk of Immobilized Plutonium Waste Form in a Geologic Repository

This purpose of this technical report is to provide a comprehensive summary of the waste package (WP) external criticality-related risk of the Plutonium Disposition ceramic waste form, which is being developed and evaluated by the Office of Fissile Materials Disposition of the United States Department of Energy (DOE). Potential accumulation of the fissile materials, {sup 239}Pu and {sup 235}U, in rock formations having a favorable chemical environment for such actions, requires analysis because autocatalytic configurations, while unlikely to form, never-the-less have consequences which are undesirable and require evaluation. Secondly, the WP design has evolved necessitating a re-evaluation of the internal WP degradation scenarios that contribute to the external source terms. The scope of this study includes a summary of the revised WP degradation calculations, a summary of the accumulation mechanisms in fractures and lithophysae in the tuff beneath the WP footprint, and a summary of the criticality risk calculations from any accumulated fissile material. Accumulations of fissile material external to the WP sufficient to pose a potential criticality risk require a deposition mechanism operating over sufficient time to reach required levels. The transporting solution concentrations themselves are well below critical levels (CRWMS 2001e). The ceramic waste form consists of Pu …
Date: March 12, 2001
Creator: McClure, J.
Object Type: Report
System: The UNT Digital Library
A practical approach to the interGroup protocols (open access)

A practical approach to the interGroup protocols

Existing reliable ordered group communication protocols have been developed for local-area networks and do not, in general, scale well to large numbers of nodes and wide-area networks. The InterGroup suite of protocols is a scalable group communication system that introduces an unusual approach to handling group membership, and supports a receiver-oriented selection of service. The protocols are intended for a wide-area network, with a large number of nodes, that has highly variable delays and a high message loss rate, such as the Internet. The levels of the message delivery service range from unreliable unordered to reliable timestamp ordered. We also present a secure group layer that builds on InterGroup to provide SSL-like security for groups.
Date: November 12, 2001
Creator: Berket, Karlo; Agarwal, Deborah A. & Chevassut, Olivier
Object Type: Article
System: The UNT Digital Library
Toward improved environmental decisions. (open access)

Toward improved environmental decisions.

A common feature of many of the current environmental issues is that the immediate impact of risks, although considered to be small by many scientists, are uncertain and potentially wide spread and significant in the long term and thus of concern to potentially affected groups. The need to formulate decisions and commit major resources in the face of these uncertainties has led to the introduction of new environmental decision making frameworks that have as a central feature consideration of the broader environmental context and a greater involvement of the affected parties in the process. Various research activities and case studies are described which are targeted at aiding further development of the decision making frameworks into a more widely useable and effective approach.
Date: January 12, 2001
Creator: Habegger, L. & MacDonell, M.
Object Type: Article
System: The UNT Digital Library
Explosive Potential Analysis of AB Process-Final Report (open access)

Explosive Potential Analysis of AB Process-Final Report

A need arose to define the hazards associated with the operation of a process. The process involved the evolution of a hydrogen gas stream from thermal decomposition of uranium hydride at approximately 400 C into the interior of a purged argon-filled glove box. Specific hazards of interest included the potential reaction severity of the evolved hydrogen with atmospheric oxygen, either downstream in the vent system or inside the box in the event of serious air inleakage. Another hazard might be the energetic reaction of inleaked air with the hot uranium and uranium hydride powder bed, possibly resulting in the dispersion of powders into an air atmosphere and the rapid combustion of the powders. This was approached as a problem in calculational simulation. Given the parameters associated with the process and the properties of the glove box system, certain scenarios were defined and the potential for flammable or detonation reactions estimated. Calculation tools included a comprehensive fluid dynamics code, a spreadsheet, a curve-fitting program, an equation solver, and a thermochemistry software package. Results are reported which suggest that the process can be operated without significant hazard to operators or significant damage to equipment, assuming that operators take account of potential upset …
Date: October 12, 2001
Creator: Bullock, J. S.; Giles Jr., G. E.; Wendel, M. W. & Sulfredge, C. D.
Object Type: Report
System: The UNT Digital Library
Liquid phase epitaxial growth and characterization of germanium far infrared blocked impurity band detectors (open access)

Liquid phase epitaxial growth and characterization of germanium far infrared blocked impurity band detectors

Germanium Blocked Impurity Band (BIB) detectors require a high purity blocking layer (< 10{sup 13} cm{sup -3}) approximately 1 mm thick grown on a heavily doped active layer ({approx} 10{sup 16} cm{sup -3}) approximately 20 mm thick. Epilayers were grown using liquid phase epitaxy (LPE) of germanium out of lead solution. The effects of the crystallographic orientation of the germanium substrate on LPE growth modes were explored. Growth was studied on substrates oriented by Laue x-ray diffraction between 0.02{sup o} and 10{sup o} from the {l_brace}111{r_brace} toward the {l_brace}100{r_brace}. Terrace growth was observed, with increasing terrace height for larger misorientation angles. It was found that the purity of the blocking layer was limited by the presence of phosphorus in the lead solvent. Unintentionally doped Ge layers contained {approx}10{sup 15} cm{sup -3} phosphorus as determined by Hall effect measurements and Photothermal Ionization Spectroscopy (PTIS). Lead purification by vacuum distillation and dilution reduced the phosphorus concentration in the layers to {approx} 10{sup 14} cm{sup -3} but further reduction was not observed with successive distillation runs. The graphite distillation and growth components as an additional phosphorus source cannot be ruled out. Antimony ({approx}10{sup 16} cm{sup -3}) was used as a dopant for the …
Date: May 12, 2001
Creator: Bandaru, Jordana
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Development of cryotribological theories & application to cryogenic devices. Final report (open access)

Development of cryotribological theories & application to cryogenic devices. Final report

This is the final report of a research program on low-temperature friction and wear, primarily focused on development of cryotribological theories and application to cryogenic devices, particularly superconducting magnets.
Date: March 12, 2001
Creator: Iwasa, Yukikazu
Object Type: Report
System: The UNT Digital Library
Synchrotron infrared spectromicroscopy as a novel bioanalytical microprobe for individual living cells: Cytotoxicity considerations (open access)

Synchrotron infrared spectromicroscopy as a novel bioanalytical microprobe for individual living cells: Cytotoxicity considerations

Synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectromicroscopy is a newly emerging analytical tool capable of monitoring the biochemistry within an individual living mammalian cell in real time. This unique technique provides infrared (IR)spectra, hence chemical information, with high signal-to-noise at spatial resolutions as fine as 3 to 10 microns. Mid-IR photons are too low in energy (0.05-0.5 eV) to either break bonds or to cause ionization, and the synchrotron IR beam has been shown to produce minimal sample heating. However, an important question remains, ''Does the intense synchrotron beam induce any cytotoxic effects in living cells?'' In this work, we present the results from a series of standard biological assays to evaluate any short-and/or long-term effects on cells exposed to the synchrotron radiation-based infrared (SR-IR) beam. Cell viability was tested using alcian blue dye-exclusion and colony formation assays. Cell-cycle progression was tested with bromodeoxyuridine (BrdU) uptake during DNA synthesis. Cell metabolism was tested using an 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay. All control, 5-, 10-, and 20-minute SR-IR exposure tests (267 total and over 1000 controls) show no evidence of cytotoxic effects. Concurrent infrared spectra obtained with each experiment confirm no detectable chemistry changes between control and exposed cells.
Date: December 12, 2001
Creator: Holman, Hoi-Ying N.; Bjornstad, Kathleen A.; McNamara, Morgan P.; Martin, Michael C.; McKinney, Wayne R. & Blakely, Eleanor A.
Object Type: Article
System: The UNT Digital Library
Proposal to DOE Basic Energy Sciences: Ultrafast X-ray Science Facility at the Advanced Light Source (open access)

Proposal to DOE Basic Energy Sciences: Ultrafast X-ray Science Facility at the Advanced Light Source

We propose to develop a true user facility for ultrafast x-ray science at the Advanced Light Source. This facility will be unique in the world, and will fill a critical need for the growing ultrafast x-ray research community. The development of this facility builds upon the expertise from long-standing research efforts in ultrafast x-ray spectroscopy and the development of femtosecond x-ray sources and techniques at both the Lawrence Berkeley National Laboratory and at U.C. Berkeley. In particular, the technical feasibility of a femtosecond x-ray beamline at the ALS has already been demonstrated, and existing ultrafast laser technology will enable such a beamline to operate near the practical limit for femtosecond x-ray flux and brightness from a 3rd generation synchrotron.
Date: December 12, 2001
Creator: Schoenlein, Robert W.; Falcone, Roger W.; Abela, R.; Alivisatos, A. P.; Belkacem, A.; Berrah, N. et al.
Object Type: Report
System: The UNT Digital Library
WATER AS A REAGENT FOR SOIL REMEDIATION (open access)

WATER AS A REAGENT FOR SOIL REMEDIATION

SRI International conducted experiments in a two-year, two-phase process to develop and evaluate hydrothermal extraction technology, also known as hot water extraction (HWE) technology, to separate petroleum-related contaminants and other hazardous pollutants from soil and sediments. In this process, water with added electrolytes (inexpensive and environmentally friendly) is used as the extracting solvent under subcritical conditions (150-300 C). The use of electrolytes allows us to operate reactors under mild conditions and to obtain high separation efficiencies that were hitherto impossible. Unlike common organic solvents, water under subcritical conditions dissolves both organics and inorganics, thus allowing opportunities for separation of both organic and inorganic material from soil. In developing this technology, our systematic approach was to (1) establish fundamental solubility data, (2) conduct treatability studies with industrial soils, and (3) perform a bench-scale demonstration using a highly contaminated soil. The bench-scale demonstration of the process has shown great promise. The next step of the development process is the successful pilot demonstration of this technology. Once pilot tested, this technology can be implemented quite easily, since most of the basic components are readily available from mature technologies (e.g., steam stripping, soil washing, thermal desorption). The implementation of this technology will revolutionize the …
Date: November 12, 2001
Creator: Jayaweera, Indira S.; Marti-Perez, Montserrat; Diaz-Ferrero, Jordi & Sanjurjo, Angel
Object Type: Report
System: The UNT Digital Library