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Criteria for Determination of Material Control and Accountability System Effectiveness (open access)

Criteria for Determination of Material Control and Accountability System Effectiveness

The Nevada Test Site (NTS) is a test bed for implementation of the Safeguards First Principles Initiative (SFPI), a risk-based approach to Material Control & Accountability (MC&A) requirements. The Comprehensive Assessment of Safeguards Strategies (COMPASS) model is used to determine the effectiveness of MC&A systems under SFPI. Under this model, MC&A is divided into nine primary elements. Each element is divided into sub-elements. Then each sub-element is assigned two values, effectiveness and contribution, that are used to calculate the rating. Effectiveness is a measure of subelement implementation and how well it meets requirements. Contribution is a relative measure of the importance, and functions as a weighting factor. The COMPASS model provides the methodology for calculation of sub-element and element ratings, but not the actual criteria. Each site must develop its own criteria. For the rating to be meaningful, the effectiveness criteria must be objective and based on explicit, measurable criteria. Contribution (weights) must reflect the importance within the MC&A program. This paper details the NTS approach to system effectiveness and contribution values, and will cover the following: the basis for the ratings, an explanation of the contribution “weights,” and the objective, performance based effectiveness criteria. Finally, the evaluation process will …
Date: March 1, 2008
Creator: Wright, John
System: The UNT Digital Library
Analysis of the causes of failure in high chrome oxide refractory materials from slagging gasifiers (open access)

Analysis of the causes of failure in high chrome oxide refractory materials from slagging gasifiers

High Cr2O3 refractory materials are used to line the hot face of slagging gasifiers. Gasifiers are reaction chambers that convert water, oxygen, and a carbon feedstock into CO, H2, and methane at temperatures as high as 1575oC and pressures up to 1000 psi. Ash in the carbon feedstock liquefies, erodes and corrodes the gasifier’s refractory liner, contributing to liner failure within a few months to two years. The failure of a refractory liner decreases a gasifier’s on-line availability and causes costly system downtime and repairs. Many factors contribute to refractory lining failure, including slag penetration and corrosion, thermal cycling, gasifier environment, and mechanical loads. The results of refractory post-mortem failure analysis and how observations relate to gasifier service life will be discussed.
Date: March 1, 2006
Creator: Bennett, J. P.; Kwong, K. -S.; Powell, C. A.; Thomas, H. & Krabbe, R. A.
System: The UNT Digital Library
Biosafety Practices and Emergency Response at the Idaho National Laboratory and Los Alamos National Laboratory (open access)

Biosafety Practices and Emergency Response at the Idaho National Laboratory and Los Alamos National Laboratory

Strict federal regulations govern the possession, use, and transfer of pathogens and toxins with potential to cause harm to the public, either through accidental or deliberate means. Laboratories registered through either the Centers for Disease Control and Prevention (CDC), the U.S. Dept. of Agriculture (USDA), or both, must prepare biosafety, security, and incident response plans, conduct drills or exercises on an annual basis, and update plans accordingly. At the Idaho National Laboratory (INL), biosafety, laboratory, and emergency management staff have been working together for 2 years to satisfy federal and DOE/NNSA requirements. This has been done through the establishment of plans, training, tabletop and walk-through exercises and drills, and coordination with local and regional emergency response personnel. Responding to the release of infectious agents or toxins is challenging, but through familiarization with the nature of the hazardous biological substances or organisms, and integration with laboratory-wide emergency response procedures, credible scenarios are being used to evaluate our ability to protect workers, the public, and the environment from agents we must work with to provide for national biodefense.
Date: March 1, 2008
Creator: Roberto, Frank F. & Matz, Dina M.
System: The UNT Digital Library
IR Spectrometer Using 90-Degree Off-Axis Parabolic Mirrors (open access)

IR Spectrometer Using 90-Degree Off-Axis Parabolic Mirrors

A gated spectrometer has been designed for real-time, pulsed infrared (IR) studies at the National Synchrotron Light Source at the Brookhaven National Laboratory. A pair of 90-degree, off-axis parabolic mirrors are used to relay the light from an entrance slit to an output recording camera. With an initial wavelength range of 1500–4500 nm required, gratings could not be used in the spectrometer because grating orders would overlap. A magnesium oxide prism, placed between these parabolic mirrors, serves as the dispersion element. The spectrometer is doubly telecentric. With proper choice of the air spacing between the prism and the second parabolic mirror, any spectral region of interest within the InSb camera array’s sensitivity region can be recorded. The wavelengths leaving the second parabolic mirror are collimated, thereby relaxing the camera positioning tolerance. To set up the instrument, two different wavelength (visible) lasers are introduced at the entrance slit and made collinear with the optical axis via flip mirrors. After dispersion by the prism, these two laser beams are directed to tick marks located on the outside housing of the gated IR camera. This provides first-order wavelength calibration for the instrument. Light that is reflected off the front prism face is coupled …
Date: March 1, 2008
Creator: Malone, Robert M. & McKenna, Ian J.
System: The UNT Digital Library
REMOVING SLUDGE HEELS FROM SAVANNAH RIVER SITE WASTE TANKS BY OXALIC ACID DISSOLUTION (open access)

REMOVING SLUDGE HEELS FROM SAVANNAH RIVER SITE WASTE TANKS BY OXALIC ACID DISSOLUTION

The Savannah River Site (SRS) will remove sludge as part of waste tank closure operations. Typically the bulk sludge is removed by mixing it with supernate to produce a slurry, and transporting the slurry to a downstream tank for processing. Experience shows that a residual heel may remain in the tank that cannot be removed by this conventional technique. In the past, SRS used oxalic acid solutions to disperse or dissolve the sludge heel to complete the waste removal. To better understand the actual conditions of oxalic acid cleaning of waste from carbon steel tanks, the authors developed and conducted an experimental program to determine its effectiveness in dissolving sludge, the hydrogen generation rate, the generation rate of other gases, the carbon steel corrosion rate, the impact of mixing on chemical cleaning, the impact of temperature, and the types of precipitates formed during the neutralization process. The test samples included actual SRS sludge and simulated SRS sludge. The authors performed the simulated waste tests at 25, 50, and 75 C by adding 8 wt % oxalic acid to the sludge over seven days. They conducted the actual waste tests at 50 and 75 C by adding 8 wt % oxalic …
Date: March 1, 2009
Creator: Poirier, M; David Herman, D; Fernando Fondeur, F; John Pareizs, J; Michael Hay, M; Bruce Wiersma, B et al.
System: The UNT Digital Library
First Observation of Coherent pi0 Production in Neutrino Nucleus Interactions with E(nu) < 2 GeV (open access)

First Observation of Coherent pi0 Production in Neutrino Nucleus Interactions with E(nu) < 2 GeV

The MiniBooNE experiment at Fermilab has amassed the largest sample to date of {pi}{sup 0}s produced in neutral current (NC) neutrino-nucleus interactions at low energy. This paper reports a measurement of the momentum distribution of {pi}{sup 0}s produced in mineral oil (CH{sub 2}) and the first observation of coherent {pi}{sup 0} production below 2 GeV. In the forward direction, the yield of events observed above the expectation for resonant production is attributed primarily to coherent production off carbon, but may also include a small contribution from diffractive production on hydrogen. Integrated over the MiniBooNE neutrino flux, the sum of the NC coherent and diffractive modes is found to be (19.5 {+-} 1.1 (stat) {+-} 2.5 (sys))% of all exclusive NC {pi}{sup 0} production at MiniBooNE. These measurements are of immediate utility because they quantify an important background to MiniBooNE's search for {nu}{sub {mu}} {yields} {nu}{sub e} oscillations.
Date: March 1, 2008
Creator: Aguilar-Arevalo, A. A.; Anderson, C. E.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J. et al.
System: The UNT Digital Library
Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV (open access)

Measurement of the t anti-t production cross section in p anti-p collisions at s**(1/2) = 1.96-TeV

We measure the t{bar t} production cross section in p{bar p} collisions at {radical}s = 1.96 TeV in the lepton+jets channel. Two complementary methods discriminate between signal and background, b-tagging and a kinematic likelihood discriminant. Based on 0.9 fb{sup -1} of data collected by the D0 detector at the Fermilab Tevatron Collider, we measure {sigma}{sub t{bar t}} = 7.62 {+-} 0.85 pb, assuming the current world average m{sub t} = 172.6 GeV. We compare our cross section measurement with theory predictions to determine a value for the top quark mass of 170 {+-} 7 GeV.
Date: March 1, 2008
Creator: Abazov, V. M.; Abbott, B.; Abolins, M.; Acharya, B. S.; Adams, M.; Adams, T. et al.
System: The UNT Digital Library
Cygnus Water Switch Jitter (open access)

Cygnus Water Switch Jitter

The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources - Cygnus 1 and Cygnus 2. Each source has the following x-ray output: 1-mm diameter spot size, 4 rad at 1 m, 50-ns Full Width Half Max. The diode pulse has the following electrical specifications: 2.25 MV, 60 kA, 60 ns. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site (NTS). The sources were developed to produce high-resolution images on subcritical tests which are performed at NTS. Subcritical tests are single-shot, high-value events. For this application, it is desirable to maintain a high level of reproducibility in source output. The major components of the Cygnus machines are: Marx generator, water-filled pulse–forming line (PFL), water-filled coaxial transmission line, three-cell inductive voltage adder, and rod-pinch diode. A primary source of fluctuation in Cygnus shot-to-shot performance is jitter in breakdown of the main PFL switch, which is a “self-break” switch. The PFL switch breakdown time determines the peak PFL charging voltage, which ultimately affects the diode pulse. Therefore, PFL switch jitter contributes to shot-to-shot variation in source endpoint energy and dose. In this paper we will present PFL switch jitter analysis for both Cygnus …
Date: March 1, 2008
Creator: Charles V. Mitton, George D. Corrow, Mark D. Hansen, David J. Henderson, et al.
System: The UNT Digital Library
Oxidation of advanced steam turbine alloys (open access)

Oxidation of advanced steam turbine alloys

Advanced or ultra supercritical (USC) steam power plants offer the promise of higher efficiencies and lower emissions. Current goals of the U.S. Department of Energy’s Advanced Power Systems Initiatives include coal generation at 60% efficiency, which would require steam temperatures of up to 760°C. This research examines the steamside oxidation of advanced alloys for use in USC systems, with emphasis placed on alloys for high- and intermediate-pressure turbine sections.
Date: March 1, 2006
Creator: Holcomb, G. R.; Covino, B. S., Jr.; Bullard, S. J. & Ziomek-Moroz, M.
System: The UNT Digital Library
What is a Beryllium Measurement? A Critical Look at Beryllium (open access)

What is a Beryllium Measurement? A Critical Look at Beryllium

DOE workplaces strive to comply with the 10 CFR 850.31(b)(1) surface concentration release criterion. The usual planning considerations for demonstrating compliance are these: how many swipes, and where; which sample preparation and analytical methods; what reporting limits; and what sample statistic to compare with the criterion. We have reviewed swipe samples from hundreds of Nevada Test Site workplaces: office buildings; experimental facilities; forward area field units; shops; and tunnels. Our experiences have led us to a critical examination of the inner workings of the measurement process itself, involving details generally taken for granted when those usual questions are asked. In this presentation we dissect the ICP-AES Be measurement process. We discuss calibration options and how they impact the distributions of analytical results. We look at distributions of blank results obtained from different labs, and discuss their relevance to determining reporting limits. We examine the way measurements are made from spectra, how that process impacts our understanding of the actual statistical distributions of Be measurements, and how interferences can affect Be measurements. Our objective is to gain sufficient confidence in the measurement process so that the usual questions will make sense and the survey results will be credible. Based on our …
Date: March 1, 2006
Creator: Davis, Charles; Field, Dan; Hess, John & Jensen, Dan
System: The UNT Digital Library
Relative Permeabilities: a pore-level model study of the capillary number dependence (open access)

Relative Permeabilities: a pore-level model study of the capillary number dependence

Relative permeabilities are widely used by the petroleum industry in reservoir simulations of recovery strategies. In recent years, pore level modeling has been used to determine relative permeabilities at zero capillary number for a variety of more and more realistic model porous media. Unfortunately, these studies cannot address the issue of the observed capillary number dependence of the relative permeabilities. Several years ago, we presented a method for determining the relative permeabilities from pore-level modeling at general capillary number. We have used this method to determine the relative permeabilities at several capillary numbers and stable viscosity ratios. In addition, we have determined these relative permeabilities using one of the standard dynamic methods for determining relative permeabilities from core flood experiments. Our results from the two methods are compared with each other and with experimental results.
Date: March 1, 2008
Creator: Ferer, M.V.; Mason, G.; Bromhal, G.S. & Smith, D.H.
System: The UNT Digital Library
Biomonitoring with Wireless Communications (open access)

Biomonitoring with Wireless Communications

This review is divided into three sections: technologies for monitoring physiological parameters; biosensors for chemical assays and wireless communications technologies including image transmissions. Applications range from monitoring high risk patients for heart, respiratory activity and falls to sensing levels of physical activity in military, rescue, and sports personnel. The range of measurements include, heart rate, pulse wave form, respiratory rate, blood oxygen, tissue pCO2, exhaled carbon dioxide and physical activity. Other feasible measurements will employ miniature chemical laboratories on silicon or plastic chips. The measurements can be extended to clinical chemical assays ranging from common blood assays to protein or specialized protein measurements (e.g., troponin, creatine, and cytokines such as TNF and IL6). Though the feasibility of using wireless technology to communicate vital signs has been demonstrated 32 years ago (1) it has been only recently that practical and portable devices and communications net works have become generally available for inexpensive deployment of comfortable and affordable devices and systems.
Date: March 1, 2003
Creator: Budinger, Thomas F.
System: The UNT Digital Library
Mercury Removal at Idaho National Engineering and Environmental Laboratory's New Waste Calcining Facility (open access)

Mercury Removal at Idaho National Engineering and Environmental Laboratory's New Waste Calcining Facility

Technologies were investigated to determine viable processes for removing mercury from the calciner (NWCF) offgas system at the Idaho National Engineering and Environmental Laboratory. Technologies for gas phase and aqueous phase treatment were evaluated. The technologies determined are intended to meet EPA Maximum Achievable Control Technology (MACT) requirements under the Clean Air Act and Resource Conservation and Recovery Act (RCRA). Currently, mercury accumulation in the calciner off-gas scrubbing system is transferred to the tank farm. These transfers lead to accumulation in the liquid heels of the tanks. The principal objective for aqueous phase mercury removal is heel mercury reduction. The system presents a challenge to traditional methods because of the presence of nitrogen oxides in the gas phase and high nitric acid in the aqueous scrubbing solution. Many old and new technologies were evaluated including sorbents and absorption in the gas phase and ion exchange, membranes/sorption, galvanic methods, and UV reduction in the aqueous phase. Process modifications and feed pre-treatment were also evaluated. Various properties of mercury and its compounds were summarized and speciation was predicted based on thermodynamics. Three systems (process modification, NOxidizer combustor, and electrochemical aqueous phase treatment) and additional technology testing were recommended.
Date: March 1, 2000
Creator: Ashworth, Samuel Clay; Wood, R. A.; Taylor, D. D. & Sieme, D. D.
System: The UNT Digital Library
Radiological Contingency Planning for the Mars Science Laboratory Launch (open access)

Radiological Contingency Planning for the Mars Science Laboratory Launch

None
Date: March 1, 2008
Creator: Guss, Paul
System: The UNT Digital Library
Learning from Mistakes --- A Comprehensive Study on Real World Concurrency Bug Characteristics. In the proceedings of the 13th International Conference on Architecture Support for Programming Languages and Operating Systems (ASPLOS'08), March 2008 (open access)

Learning from Mistakes --- A Comprehensive Study on Real World Concurrency Bug Characteristics. In the proceedings of the 13th International Conference on Architecture Support for Programming Languages and Operating Systems (ASPLOS'08), March 2008

The reality of multi-core hardware has made concurrent programs pervasive. Unfortunately, writing correct concurrent programs is dif#2;cult. Addressing this challenge requires advances in multiple directions, including concurrency bug detection, concurrent program testing, concurrent programming model design, etc. Designing effective techniques in all these directions will signi#2;cantly bene#2;t from a deep understanding of real world concurrency bug characteristics. This paper provides the #2;rst (to the best of our knowledge) comprehensive real world concurrency bug characteristic study. Specifically, we have carefully examined concurrency bug patterns, manifestation, and #2;x strategies of 105 randomly selected real world concurrency bugs from 4 representative server and client opensource applications (MySQL, Apache, Mozilla and OpenOf#2;ce). Our study reveals several interesting #2;ndings and provides useful guidance for concurrency bug detection, testing, and concurrent programming language design. Some of our #2;ndings are as follows: (1) Around one third of the examined non-deadlock concurrency bugs are caused by violation to programmers' order intentions, which may not be easily expressed via synchronization primitives like locks and transactional memories; (2) Around 34% of the examined non-deadlock concurrency bugs involve multiple variables, which are not well addressed by existing bug detection tools; (3) About 92% of the examined concurrency bugs can be reliably …
Date: March 1, 2008
Creator: Park, Yuanyuan Zhou Shan Lu Soyeon
System: The UNT Digital Library
DEVELOPMENT OF A CROSSFLOW FILTER TO REMOVE SOLIDS FROM RADIOACTIVE LIQUID WASTE: COMPARISON OF TEST DATA WITH OPERATING EXPERIENCE - 9119 (open access)

DEVELOPMENT OF A CROSSFLOW FILTER TO REMOVE SOLIDS FROM RADIOACTIVE LIQUID WASTE: COMPARISON OF TEST DATA WITH OPERATING EXPERIENCE - 9119

In 2008, the Savannah River Site (SRS) began treatment of liquid radioactive waste from its Tank Farms. To treat waste streams containing {sup 137}Cs, {sup 90}Sr, and actinides, SRS developed the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The Actinide Removal Process contacts the waste with monosodium titanate (MST) to sorb strontium and select actinides. After MST contact, the process filters the resulting slurry to remove the MST (with sorbed strontium and actinides) and any entrained sludge. The filtrate is transported to the MCU to remove cesium. The solid particle removed by the filter are concentrated to {approx} 5 wt %, washed to reduce the concentration of dissolved sodium, and transported to the Defense Waste Processing Facility (DWPF) for vitrification. The authors conducted tests with 0.5 {micro} and 0.1 {micro} Mott sintered stainless steel crossflow filter at bench-scale (0.19 ft{sup 2} surface area) and pilot-scale (11.2 ft{sup 2}). The collected data supported design of the filter for the process and identified preferred operating conditions for the full-scale process (230 ft{sup 2}). The testing investigated the influence of operating parameters, such as filter pore size, axial velocity, transmembrane pressure, and solids loading, on filter flux, …
Date: March 1, 2009
Creator: Poirier, M; David Herman, D; Samuel Fink, S & Julius Lacerna, J
System: The UNT Digital Library
EVALUATING ROBOT TECHNOLOGIES AS TOOLS TO EXPLORE RADIOLOGICAL AND OTHER HAZARDOUS ENVIRONMENTS (open access)

EVALUATING ROBOT TECHNOLOGIES AS TOOLS TO EXPLORE RADIOLOGICAL AND OTHER HAZARDOUS ENVIRONMENTS

There is a general consensus that robots could be beneficial in performing tasks within hazardous radiological environments. Most control of robots in hazardous environments involves master-slave or teleoperation relationships between the human and the robot. While teleoperation-based solutions keep humans out of harms way, they also change the training requirements to accomplish a task. In this paper we present a research methodology that allowed scientists at Idaho National Laboratory to identify, develop, and prove a semi-autonomous robot solution for search and characterization tasks within a hazardous environment. Two experiments are summarized that validated the use of semi-autonomy and show that robot autonomy can help mitigate some of the performance differences between operators who have different levels of robot experience, and can improve performance over teleoperated systems.
Date: March 1, 2008
Creator: Nielsen, Curtis W.; Gertman, David I.; Bruemmer, David J.; Hartley, R. Scott & Walton, Miles C.
System: The UNT Digital Library
Coral Reef Genomics: Developing tools for functional genomics ofcoral symbiosis (open access)

Coral Reef Genomics: Developing tools for functional genomics ofcoral symbiosis

Symbioses between cnidarians and dinoflagellates in the genus Symbiodinium are widespread in the marine environment. The importance of this symbiosis to reef-building corals and reef nutrient and carbon cycles is well documented, but little is known about the mechanisms by which the partners establish and regulate the symbiosis. Because the dinoflagellate symbionts live inside the cells of their host coral, the interactions between the partners occur on cellular and molecular levels, as each partner alters the expression of genes and proteins to facilitate the partnership. These interactions can examined using high-throughput techniques that allow thousands of genes to be examined simultaneously. We are developing the groundwork so that we can use DNA microarray profiling to identify genes involved in the Montastraea faveolata and Acropora palmata symbioses. Here we report results from the initial steps in this microarray initiative, that is, the construction of cDNA libraries from 4 of 16 target stages, sequencing of 3450 cDNA clones to generate Expressed Sequenced Tags (ESTs), and annotation of the ESTs to identify candidate genes to include in the microarrays. An understanding of how the coral-dinoflagellate symbiosis is regulated will have implications for atmospheric and ocean sciences, conservation biology, the study and diagnosis of …
Date: March 1, 2005
Creator: Schwarz, Jodi; Brokstein, Peter; Manohar, Chitra; Coffroth, MaryAlice; Szmant, Alina & Medina, Monica
System: The UNT Digital Library
Nuclear Materials Management U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO) (open access)

Nuclear Materials Management U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO)

In light of the changing Defense Complex mission, the high cost to storing and protecting nuclear materials, and in consideration of scarcity of resources, it is imperative that the U.S. Department of Energy (DOE) owned nuclear materials are managed effectively. The U.S. Department of Energy, National Nuclear Security Administration (NNSA) Strategic Action Plan outlines the strategy for continuing to meet America’s nuclear security goals, meeting the overall mission challenges of DOE and NNSA as well as giving focus to local missions. The mission of the NNSA/NSO Nuclear Materials Management (NMM) Program is to ensure that nuclear material inventories are accurately assessed and reported, future material needs are adequately planned, and that existing Nevada Test Site (NTS) inventories are efficiently utilized, staged, or dispositioned. The NNSA/NSO understands that the NTS has unique characteristics to serve and benefit the nation with innovative solutions to the complex problems involving Special Nuclear Materials, hazardous materials, and multi-agency, integrated operations. The NNSA/NSO is defining infrastructure requirements for known future missions, developing footprint consolidation strategic action plans, and continuing in the path of facility modernization improvements. The NNSA/NSO is striving for the NTS to be acknowledged as an ideal location towards mission expansion and growth. The …
Date: March 1, 2008
Creator: Schreiber, Jesse
System: The UNT Digital Library
Corrosion behavior of experimental and commercial nickel-base alloys in HCl and HCl containing Fe3+ (open access)

Corrosion behavior of experimental and commercial nickel-base alloys in HCl and HCl containing Fe3+

The effects of ferric ions on the corrosion resistance and electrochemical behavior of a series of Ni-based alloys in 20% HCl at 30ºC were investigated. The alloys studied were those prepared by the Albany Research Center (ARC), alloys J5, J12, J13, and those sold commercially, alloys 22, 242, 276, and 2000. Tests included mass loss, potentiodynamic polarization, and linear polarization.
Date: March 1, 2006
Creator: Holcomb, G. R.; Covino, B. S., Jr.; Bullard, S. J. & Ziomek-Moroz, M.
System: The UNT Digital Library
BOBCAT Personal Radiation Detector Field Test and Evaluation Campaign (open access)

BOBCAT Personal Radiation Detector Field Test and Evaluation Campaign

Following the success of the Anole test of portable detection system, the U.S. Department of Homeland Security (DHS) Domestic Nuclear Detection Office organized a test and evaluation campaign for personal radiation detectors (PRDs), also known as “Pagers.” This test, “Bobcat,” was conducted from July 17 to August 8, 2006, at the Nevada Test Site. The Bobcat test was designed to evaluate the performance of PRDs under various operational scenarios, such as pedestrian surveying, mobile surveying, cargo container screening, and pedestrian chokepoint monitoring. Under these testing scenarios, many operational characteristics of the PRDs, such as gamma and neutron sensitivities, positive detection and false alarm rates, response delay times, minimum detectable activities, and source localization errors, were analyzed. This paper will present the design, execution, and methodologies used to test this equipment for the DHS.
Date: March 1, 2008
Creator: Hodge, Chris
System: The UNT Digital Library
Developing Fieldable Systems for Chemical Sensing Using Field Asymmetric Ion Mobility Spectrometry and Mass Spectrometry (open access)

Developing Fieldable Systems for Chemical Sensing Using Field Asymmetric Ion Mobility Spectrometry and Mass Spectrometry

Currently, there is an urgent need for field-rugged and field-programmable sensor systems that provide highly selective, universal monitoring of vapors and aerosols at detectable levels from persons or areas involved with illicit chemical/biological/explosives (CBE) production. These devices must be portable, low cost, robust, and provide accurate measurements to avoid both false positive and negative results. Furthermore, the information provided by the devices must be received in a timely manner so that informed decisions can be immediately made and the appropriate actions taken. Two technologies that are unparalleled in their sensitivity, selectivity, and trace-level detection capabilities are field asymmetric ion mobility spectrometry (FAIMS) and mass spectrometry. Here, we will show progress that has been made toward developing fieldable FAIMS systems and mass spectrometers. Working in collaboration with Sionex Corporation, the microDMx detector was equipped with a continuous air sampling system to develop selective methods for the analysis of compounds of interest. A microdiaphragm pump (KNF Neuberger, Inc.) is used to pull in gas-phase analytes directly from the air for separation and detection with the FAIMS system. The FAIMS evaluation platform (SVAC) unit currently measures 9.8-inch x 4.6-inch x 3.2-inch, weighs 3.1 lb, and utilizes a {sup 63}Ni source to ionize incoming …
Date: March 1, 2008
Creator: Kevin Kyle, Stephan Weeks, R. Trainham
System: The UNT Digital Library
Preliminary Benchmarking and MCNP Simulation Results for Homeland Security (open access)

Preliminary Benchmarking and MCNP Simulation Results for Homeland Security

The purpose of this article is to create Monte Carlo N-Particle (MCNP) input stacks for benchmarked measurements sufficient for future perturbation studies and analysis. The approach was to utilize historical experimental measurements to recreate the empirical spectral results in MCNP, both qualitatively and quantitatively. Results demonstrate that perturbation analysis of benchmarked MCNP spectra can be used to obtain a better understanding of field measurement results which may be of national interest. If one or more spectral radiation measurements are made in the field and deemed of national interest, the potential source distribution, naturally occurring radioactive material shielding, and interstitial materials can only be estimated in many circumstances. The effects from these factors on the resultant spectral radiation measurements can be very confusing. If benchmarks exist which are sufficiently similar to the suspected configuration, these benchmarks can then be compared to the suspect measurements. Having these benchmarks with validated MCNP input stacks can substantially improve the predictive capability of experts supporting these efforts.
Date: March 1, 2008
Creator: Hayes, Robert
System: The UNT Digital Library
Fireside corrosion probes for fossil fuel combustion (open access)

Fireside corrosion probes for fossil fuel combustion

Electrochemical corrosion rate probes have been constructed and tested along with mass loss coupons in environments consisting of N2/O2/CO2/SO2 plus water vapor. Temperatures ranged from 450° to 700°C. Results show that electrochemical corrosion rates for ash-covered mild steel are a function of time, temperature, and gaseous environment. Correlation between the electrochemical and mass loss corrosion rates was poor.
Date: March 1, 2006
Creator: Covino, B. S., Jr.; Bullard, S. J.; Ziomek-Moroz, M.; Holcomb, G. R. & Eden, D. A.
System: The UNT Digital Library