SURFACE GEOPHYSICAL EXPLORATION OF B & BX & BY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH MAGNETICS AND ELECTROMAGNETICS (open access)

SURFACE GEOPHYSICAL EXPLORATION OF B & BX & BY TANK FARMS AT THE HANFORD SITE RESULTS OF BACKGROUND CHARACTERIZATION WITH MAGNETICS AND ELECTROMAGNETICS

This report documents the results of preliminary surface geophysical exploration activities performed between October and December 2006 at the B, BX, and BY tank farms (B Complex). The B Complex is located in the 200 East Area of the U. S. Department of Energy's Hanford Site in Washington State. The objective of the preliminary investigation was to collect background characterization information with magnetic gradiometry and electromagnetic induction to understand the spatial distribution of metallic objects that could potentially interfere with the results from high resolution resistivity survey. Results of the background characterization show there are several areas located around the site with large metallic subsurface debris or metallic infrastructure.
Date: September 28, 2007
Creator: DA, MYERS
Object Type: Report
System: The UNT Digital Library
LLNL Facility Screening Report (SCR) for B362 (open access)

LLNL Facility Screening Report (SCR) for B362

None
Date: September 14, 2007
Creator: Cooper, G
Object Type: Report
System: The UNT Digital Library
Progress with Tevatron Electron Lenses (open access)

Progress with Tevatron Electron Lenses

None
Date: September 13, 2007
Creator: Kamerdzhiev, V.; Alexahin, Y.; Kuznetsov, G. F.; Shiltsev, V. D. & Zhang, X.
Object Type: Article
System: The UNT Digital Library
A Built for Purpose Micro-Hole Coiled Tubing Rig (MCTR) (open access)

A Built for Purpose Micro-Hole Coiled Tubing Rig (MCTR)

This report will serve as the final report on the work performed from the contract period October 2005 thru April 2007. The project 'A Built for Purpose Microhole Coiled Tubing Rig (MCTR)' purpose was to upgrade an existing state-of-the-art Coiled Tubing Drilling Rig to a Microhole Coiled Tubing Rig (MCTR) capable of meeting the specifications and tasks of the Department of Energy. The individual tasks outlined to meet the Department of Energy's specifications are: (1) Concept and development of lubricator and tool deployment system; (2) Concept and development of process control and data acquisition; (3) Concept and development of safety and efficiency improvements; and (4) Final unit integration and testing. The end result of the MCTR upgrade has produced a unit capable of meeting the following requirements: (1) Capable of handling 1-inch through 2-3/8-inch coiled tubing (Currently dressed for 2-3/8-inch coiled tubing and capable of running up to 3-1/2-inch coiled tubing); (2) Capable of drilling and casing surface, intermediate, production and liner hole intervals; (3) Capable of drilling with coiled tubing and has all controls and installation piping for a top drive; (4) Rig is capable of running 7-5/8-inch range 2 casing; and (5) Capable of drilling 5,000 ft true …
Date: September 30, 2007
Creator: Patton, Bart
Object Type: Report
System: The UNT Digital Library
Direct Assay of Filter Media following DEOX Testing (open access)

Direct Assay of Filter Media following DEOX Testing

The direct assay of filter media by gamma spectrometry following DEOX testing has distinct advantages over analytical chemistry. Prior to using gamma spectrometry for the quantification of cesium (Cs-137), a calibration must be established with known sources since gamma spectrometry yields relative results. Quantitative analytical chemistry, in particular ICP-MS, has been performed on the filter media for comparison to the gamma spectrometry data. The correlation of gamma spectrometry to ICP-MS data is presented to justify the continued use of gamma spectrometry for filter media.
Date: September 1, 2007
Creator: Lind, R. P.; Giglio, J. J.; Cummings, D. G.; Huntley, M. W.; Morgan, C. D.; Bateman, K. J. et al.
Object Type: Article
System: The UNT Digital Library
Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts (open access)

Conversion of Hydrogen Sulfide in Coal Gases to Liquid Elemental Sulfur with Monolithic Catalysts

Removal of hydrogen sulfide (H{sub 2}S) from coal gasifier gas and sulfur recovery are key steps in the development of Department of Energy's (DOE's) advanced power plants that produce electric power and clean transportation fuels with coal and natural gas. These plants will require highly clean coal gas with H{sub 2}S below 1 ppmv and negligible amounts of trace contaminants such as hydrogen chloride, ammonia, alkali, heavy metals, and particulate. The conventional method of sulfur removal and recovery employing amine, Claus, and tail-gas treatment is very expensive. A second generation approach developed under DOE's sponsorship employs hot-gas desulfurization (HGD) using regenerable metal oxide sorbents followed by Direct Sulfur Recovery Process (DSRP). However, this process sequence does not remove trace contaminants and is targeted primarily towards the development of advanced integrated gasification combined cycle (IGCC) plants that produce electricity (not both electricity and transportation fuels). There is an immediate as well as long-term need for the development of cleanup processes that produce highly clean coal gas for next generation power plants. To this end, a novel process is now under development at several research organizations in which the H{sub 2}S in coal gas is directly oxidized to elemental sulfur over a …
Date: September 30, 2007
Creator: Kwon, K. C.
Object Type: Report
System: The UNT Digital Library
New Equalizers for Antiproton Stochastic Cooling at Fermilab (open access)

New Equalizers for Antiproton Stochastic Cooling at Fermilab

In the continuous effort to improve antiproton stacking rate, a new type of equalizers has been developed and installed in antiproton accumulator. The R&D of these new equalizers is described in this paper. Equalizers are used in Fermilab antiproton stochastic cooling to compensate frequency response of the cooling system. Usually both amplitude and phase compensations are needed. However in most cases it is difficult to achieve a satisfactory compensation for both because of their interdependence. To make it more difficult is that in some cases large compensations (10 to 20 db of amplitude compensation or more than 100 degree of phase compensation) are needed near the low or high ends of a frequency band. Recently a new compensation scheme of equalizers is proposed for Fermilab antiproton accumulator. This scheme originated from the requirement to maximize the system performance resulting in a request for the phase of the cooling system transfer function to be extremely flat. For this kind of phase correction, a new type of equalizers has been developed.
Date: September 13, 2007
Creator: Lebedev, V. A.; Pasquinelli, R. J. & Sun, D.
Object Type: Article
System: The UNT Digital Library
Commercial-Scale Performance Predictions for High-Temperature Electrolysis Plants Coupled to Three Advanced Reactor Types (open access)

Commercial-Scale Performance Predictions for High-Temperature Electrolysis Plants Coupled to Three Advanced Reactor Types

This report presents results of system analyses that have been developed to assess the hydrogen production performance of commercial-scale high-temperature electrolysis (HTE) plants driven by three different advanced reactor – power-cycle combinations: a high-temperature helium cooled reactor coupled to a direct Brayton power cycle, a supercritical CO2-cooled reactor coupled to a direct recompression cycle, and a sodium-cooled fast reactor coupled to a Rankine cycle. The system analyses were performed using UniSim software. The work described in this report represents a refinement of previous analyses in that the process flow diagrams include realistic representations of the three advanced reactors directly coupled to the power cycles and integrated with the high-temperature electrolysis process loops. In addition, this report includes parametric studies in which the performance of each HTE concept is determined over a wide range of operating conditions. Results of the study indicate that overall thermal-to- hydrogen production efficiencies (based on the low heating value of the produced hydrogen) in the 45 - 50% range can be achieved at reasonable production rates with the high-temperature helium cooled reactor concept, 42 - 44% with the supercritical CO2-cooled reactor and about 33 - 34% with the sodium-cooled reactor.
Date: September 1, 2007
Creator: McKellar, M. G.; O'Brien, J. E. & Herring, J. S.
Object Type: Report
System: The UNT Digital Library
Nonlinear Statistical Signal Processing: A Particle Filtering Approach (open access)

Nonlinear Statistical Signal Processing: A Particle Filtering Approach

A introduction to particle filtering is discussed starting with an overview of Bayesian inference from batch to sequential processors. Once the evolving Bayesian paradigm is established, simulation-based methods using sampling theory and Monte Carlo realizations are discussed. Here the usual limitations of nonlinear approximations and non-gaussian processes prevalent in classical nonlinear processing algorithms (e.g. Kalman filters) are no longer a restriction to perform Bayesian inference. It is shown how the underlying hidden or state variables are easily assimilated into this Bayesian construct. Importance sampling methods are then discussed and shown how they can be extended to sequential solutions implemented using Markovian state-space models as a natural evolution. With this in mind, the idea of a particle filter, which is a discrete representation of a probability distribution, is developed and shown how it can be implemented using sequential importance sampling/resampling methods. Finally, an application is briefly discussed comparing the performance of the particle filter designs with classical nonlinear filter implementations.
Date: September 19, 2007
Creator: Candy, J
Object Type: Article
System: The UNT Digital Library
On the Virial Theorem for Interstellar Medium (open access)

On the Virial Theorem for Interstellar Medium

An attempt has been made to derive a version of the virial integral that would describe average properties of the interstellar medium (ISM). It is suggested to eliminate the (large) contribution of stellar matter by introducing 'exclusion zones' surrounding stars. Such an approach leads to the appearance of several types of additional surface integrals in the general expression. Their contribution depends on the rate of energy and matter exchange between the stars and ISM. If this exchange is weak, one can obtain a desired virial integral for ISM. However, the presence of intermittent large-scale energetic events significantly constrains the applicability of the virial theorem. If valid, the derived virial integral is dominated by cold molecular/atomic clouds, with only minor contribution of the global magnetic field and low-density warm part.
Date: September 24, 2007
Creator: Ryutov, D.
Object Type: Article
System: The UNT Digital Library
A Cell-Centered Adaptive Projection Method for the IncompressibleNavier-Stokes Equations in Three Dimensions (open access)

A Cell-Centered Adaptive Projection Method for the IncompressibleNavier-Stokes Equations in Three Dimensions

We present a method for computing incompressible viscousflows in three dimensions using block-structured local refinement in bothspace and time. This method uses a projection formulation based on acell-centered approximate projection, combined with the systematic use ofmultilevel elliptic solvers to compute increments in the solutiongenerated at boundaries between refinement levels due to refinement intime. We use an L_0-stable second-order semi-implicit scheme to evaluatethe viscous terms. Results are presentedto demonstrate the accuracy andeffectiveness of this approach.
Date: September 25, 2007
Creator: Martin, D.F.; Colella, P. & Graves, D.T.
Object Type: Article
System: The UNT Digital Library
Strengthening the foundations of proliferation assessment tools. (open access)

Strengthening the foundations of proliferation assessment tools.

Robust and reliable quantitative proliferation assessment tools have the potential to contribute significantly to a strengthened nonproliferation regime and to the future deployment of nuclear fuel cycle technologies. Efforts to quantify proliferation resistance have thus far met with limited success due to the inherent subjectivity of the problem and interdependencies between attributes that lead to proliferation resistance. We suggest that these limitations flow substantially from weaknesses in the foundations of existing methodologies--the initial data inputs. In most existing methodologies, little consideration has been given to the utilization of varying types of inputs--particularly the mixing of subjective and objective data--or to identifying, understanding, and untangling relationships and dependencies between inputs. To address these concerns, a model set of inputs is suggested that could potentially be employed in multiple approaches. We present an input classification scheme and the initial results of testing for relationships between these inputs. We will discuss how classifying and testing the relationship between these inputs can help strengthen tools to assess the proliferation risk of nuclear fuel cycle processes, systems, and facilities.
Date: September 1, 2007
Creator: Rexroth, Paul E.; Saltiel, David H.; Rochau, Gary Eugene; Cleary, Virginia D.; Ng, Selena (AREVA NC, Paris, France); Greneche, Dominique (AREVA NC, Paris, France) et al.
Object Type: Report
System: The UNT Digital Library
AN EVALUATION OF POTENTIAL LINER MATERIALS FOR ELIMINATING FCCI IN IRRADIATED METALLIC NUCLEAR FUEL ELEMENTS (open access)

AN EVALUATION OF POTENTIAL LINER MATERIALS FOR ELIMINATING FCCI IN IRRADIATED METALLIC NUCLEAR FUEL ELEMENTS

Metallic nuclear fuels are being looked at as part of the Global Nuclear Energy Program for transmuting longlive transuranic actinide isotopes contained in spent nuclear fuel into shorter-lived fission products. In order to optimize the performance of these fuels, the concept of using liners to eliminate the fuel/cladding chemical interactions that can occur during irradiation of a fuel element has been investigated. The potential liner materials Zr and V have been tested using solid-solid diffusion couples, consisting of liner materials butted against fuel alloys and against cladding materials. The couples were annealed at the relatively high temperature of 700°C. This temperature would be the absolute maximum temperature present at the fuel/cladding interface for a fuel element in-reactor. Analysis was performed using a scanning electron microscope equipped with energy-dispersive and wavelengthdispersive spectrometers (SEM/EDS/WDS) to evaluate any developed diffusion structures. At 700°C, minimal interaction was observed between the metallic fuels and either Zr or V. Similarly, limited interaction was observed between the Zr and V and the cladding materials. The best performing liner material appeared to be the V, based on amounts of interaction.
Date: September 1, 2007
Creator: Keiser, D. D. & Cole, J. I.
Object Type: Article
System: The UNT Digital Library
Use of composite materials, health monitoring and self-healing concepts to refurbish our civil and military infrastructure. (open access)

Use of composite materials, health monitoring and self-healing concepts to refurbish our civil and military infrastructure.

An unavoidable by-product of a metallic structure's use is the appearance of crack, corrosion, erosion and other flaws. Economic barriers to the replacement of these structures have created an aging civil and military infrastructure and placed even greater demands on efficient and safe repair and inspection methods. As a result of Homeland Security issues and these aging infrastructure concerns, increased attention has been focused on the rapid repair and preemptive reinforcement of structures such as buildings and bridges. This Laboratory Directed Research and Development (LDRD) program established the viability of using bonded composite patches to repair metallic structures. High modulus fiber-reinforced polymer (FRP) material may be used in lieu of mechanically fastened metallic patches or welds to reinforce or repair damaged structures. Their use produces a wide array of engineering and economic advantages. Current techniques for strengthening steel structures have several drawbacks including requiring heavy equipment for installation, poor fatigue performance, and the need for ongoing maintenance due to continued corrosion attack or crack growth. The use of bonded composite doublers has the potential to correct the difficulties associated with current repair techniques and the ability to be applied where there are currently no rehabilitation options. Applications include such diverse …
Date: September 1, 2007
Creator: Roach, Dennis Patrick; Delong, Waylon Anthony; White, Scott (University of Illinois, Urbana, Illinois); Yepez, Esteban; Rackow, Kirk A. & Reedy, Earl David, Jr.
Object Type: Report
System: The UNT Digital Library
Caterpillar MorElectric DOE Idle Reduction Demonstration Program (open access)

Caterpillar MorElectric DOE Idle Reduction Demonstration Program

This project titled 'Demonstration of the New MorElectric{trademark} Technology as an Idle Reduction Solution' is one of four demonstration projects awarded by the US Department of Energy in 2002. The goal of these demonstration and evaluation projects was to gather objective in-use information on the performance of available idle reduction technologies by characterizing the cost; fuel, maintenance, and engine life savings; payback; and user impressions of various systems and techniques. In brief, the Caterpillar Inc. project involved applying electrically driven accessories for cab comfort during engine-off stops and for reducing fuel consumption during on-highway operation. Caterpillar had equipped and operated five new trucks with the technology in conjunction with International Truck and Engine Corporation and COX Transfer. The most significant result of the project was a demonstrated average idle reduction of 13.8% for the 5 truck MEI fleet over the control fleet. It should be noted that the control fleet trucks were also equipped with an idle reduction device that would start and stop the main engine automatically in order to maintain cab temperature. The control fleet idle usage would have been reduced by 3858 hours over the 2 year period with the MEI system installed, or approximately 2315 gallons …
Date: September 30, 2007
Creator: Bernardi, John
Object Type: Report
System: The UNT Digital Library
Power conversion from environmentally scavenged energy sources. (open access)

Power conversion from environmentally scavenged energy sources.

As the power requirements for modern electronics continue to decrease, many devices which were once dependent on wired power are now being implemented as portable devices operating from self-contained power sources. The most prominent source of portable power is the electrochemical battery, which converts chemical energy into electricity. However, long lasting batteries require large amounts of space for chemical storage, and inevitably require replacement when the chemical reaction no longer takes place. There are many transducers and scavenging energy sources (SES) that are able to exploit their environment to generate low levels of electrical power over a long-term time period, including photovoltaic cells, thermoelectric generators, thermionic generators, and kinetic/piezoelectric power generators. This generated power is sustainable as long as specific environmental conditions exist and also does not require the large volume of a long lifetime battery. In addition to the required voltage generation, stable power conversion requires excess energy to be efficiently stored in an ultracapacitor or similar device and monitoring control algorithms to be implemented, while computer modeling and simulation can be used to complement experimental testing. However, building an efficient and stable power source scavenged from a varying input source is challenging.
Date: September 1, 2007
Creator: Druxman, Lee Daniel
Object Type: Report
System: The UNT Digital Library
Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU ZP-1 Wells 299-W10-33 and 299-W11-48 (open access)

Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU ZP-1 Wells 299-W10-33 and 299-W11-48

Slug-test results obtained from single and multiple, stress-level slug tests conducted during drilling and borehole advancement provide detailed hydraulic conductivity information at two Hanford Site Operable Unit (OU) ZP-1 test well locations. The individual test/depth intervals were generally sited to provide hydraulic-property information within the upper ~10 m of the unconfined aquifer (i.e., Ringold Formation, Unit 5). These characterization results complement previous and ongoing drill-and-test characterization programs at surrounding 200-West and -East Area locations (see Figure S.1).
Date: September 30, 2007
Creator: Newcomer, Darrell R.
Object Type: Report
System: The UNT Digital Library
Plastic Straining of Iridium Alloy DOP-26 During Cup Sizing Operations (open access)

Plastic Straining of Iridium Alloy DOP-26 During Cup Sizing Operations

DOP-26 iridium alloy cups are used for fuel cladding for radioisotope power systems. The cups are deep drawn and recrystallized prior to final fabrication operations. This study characterizes the plastic deformation of cups during a sizing operation following the recrystallization heat treatment. The purpose of the sizing operation is to achieve the specified roundness, diameter, and radius dimensions of the cup. The operation introduces various levels of plastic strain in the cup. Plastic strain can be a cause of inhomogeneous or abnormal grain growth during subsequent exposure to elevated temperature during the service life of the fueled clad. This is particularly true in the case of cups which have irregularities in the cup walls from the deep drawing operations. Diameter and roundness measurements were made on two cups both before and after sizing. Plastic strain levels were calculated using the ABAQUSTM finite element software. The calculated plastic strain levels in both cups were below 0.025, a value shown to be below the critical strain for abnormal grain growth during a simulated service exposure. The calculated maximum plastic strain was found to increase with increased applied sizing load and was not sensitive to the input value for the clearance between the …
Date: September 1, 2007
Creator: Ohriner, Evan Keith; Ulrich, George B & Sabau, Adrian S
Object Type: Report
System: The UNT Digital Library
Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 3, Bryan Mound Site, Texas. (open access)

Sonar atlas of caverns comprising the U.S. Strategic Petroleum Reserve. Volume 3, Bryan Mound Site, Texas.

Downhole sonar surveys from the four active U.S. Strategic Petroleum Reserve sites have been modeled and used to generate a four-volume sonar atlas, showing the three-dimensional geometry of each cavern. This volume 3 focuses on the Bryan Mound SPR site, located in southeastern Texas. Volumes 1, 2, and 4, respectively, present images for the Bayou Choctaw SPR site, Louisiana, the Big Hill SPR site, Texas, and the West Hackberry SPR site, Louisiana. The atlas uses a consistent presentation format throughout. The basic geometric measurements provided by the down-cavern surveys have also been used to generate a number of geometric attributes, the values of which have been mapped onto the geometric form of each cavern using a color-shading scheme. The intent of the various geometrical attributes is to highlight deviations of the cavern shape from the idealized cylindrical form of a carefully leached underground storage cavern in salt. The atlas format does not allow interpretation of such geometric deviations and anomalies. However, significant geometric anomalies, not directly related to the leaching history of the cavern, may provide insight into the internal structure of the relevant salt dome.
Date: September 1, 2007
Creator: Rautman, Christopher Arthur & Lord, Anna Snider
Object Type: Report
System: The UNT Digital Library
Soft Phonons in (delta)-Phase Plutonium Near the (delta)-(alpha)' Transition (open access)

Soft Phonons in (delta)-Phase Plutonium Near the (delta)-(alpha)' Transition

Plutonium and its alloys exhibit complex phase diagrams that imply anomalous lattice dynamics near phase stability boundaries. Specifically, the TA [111] phonon branch in Ga-stabilized {delta}-Pu at room temperature shows a pronounced soft mode at the zone boundary, which suggests a possible connection to the martensitic transformation from the fcc {delta}-phase to the monoclinic {alpha}{prime}-phase at low temperatures. This work is a study of the lattice dynamics of this system by x-ray thermal diffuse scattering. The results reveal little temperature dependence of the phonon frequencies, thus indicating that kinetic phonon softening is not responsible for this phase transition.
Date: September 13, 2007
Creator: Xu, R; Wong, J; Zshack, P; Hong, H & Chiang, T
Object Type: Article
System: The UNT Digital Library
The polarized SRF gun experiment. (open access)

The polarized SRF gun experiment.

RF electron guns are capable of producing electron bunches with high brightness, which outperform DC electron guns and may even be able to provide electron beams for the ILC without the need for a damping ring. However, all successful existing guns for polarized electrons are DC guns because the environment inside an RF gun is hostile to the GaAs cathode material necessary for polarization. While the typical vacuum pressure in a DC gun is better than 10{sup -11} torr the vacuum in an RF gun is in the order of 10{sup -9} torr. Experiments at BINP Novosibirsk show that this leads to strong ion back-bombardment and generation of dark currents, which destroy the GaAs cathode in a short time. The situation might be much more favorable in a (super-conducting) SRF gun. The cryogenic pumping of the gun cavity walls may make it possible to maintain a vacuum close to 10{sup -12} torr, solving the problem of ion bombardment and dark currents. Of concern would be contamination of the gun cavity by evaporating cathode material. This report describes an experiment that Brookhaven National Laboratory (BNL) in collaboration with Advanced Energy Systems (AES) is conducting to answer these questions.
Date: September 10, 2007
Creator: Kewisch, J.; Ben-Zvi, Ilan; Rao, T.; Burrill, A.; Pate, D.; Grover, R. et al.
Object Type: Article
System: The UNT Digital Library
Numerical modeling of self-limiting and self-enhancing caprock alteration induced by CO2 storage in a depleted gas reservoir (open access)

Numerical modeling of self-limiting and self-enhancing caprock alteration induced by CO2 storage in a depleted gas reservoir

This paper presents numerical simulations of reactive transport which may be induced in the caprock of an on-shore depleted gas reservoir by the geological sequestration of carbon dioxide. The objective is to verify that CO{sub 2} geological disposal activities currently being planned for the study area are safe and do not induce any undesired environmental impact. In our model, fluid flow and mineral alteration are induced in the caprock by penetration of high CO{sub 2} concentrations from the underlying reservoir, where it was assumed that large amounts of CO{sub 2} have already been injected at depth. The main focus is on the potential effect of precipitation and dissolution processes on the sealing efficiency of caprock formations. Concerns that some leakage may occur in the investigated system arise because the seal is made up of potentially highly-reactive rocks, consisting of carbonate-rich shales (calcite+dolomite averaging up to more than 30% of solid volume fraction). Batch simulations and multi-dimensional 1D and 2D modeling have been used to investigate multicomponent geochemical processes. Numerical simulations account for fracture-matrix interactions, gas phase participation in multiphase fluid flow and geochemical reactions, and kinetics of fluid-rock interactions. The geochemical processes and parameters to which the occurrence of high …
Date: September 7, 2007
Creator: Xu, Tianfu; Gherardi, Fabrizio; Xu, Tianfu & Pruess, Karsten
Object Type: Article
System: The UNT Digital Library
Sample extraction and injection with a microscale preconcentrator. (open access)

Sample extraction and injection with a microscale preconcentrator.

This report details the development of a microfabricated preconcentrator that functions as a fully integrated chemical extractor-injector for a microscale gas chromatograph (GC). The device enables parts-per-billion detection and quantitative analysis of volatile organic compounds (VOCs) in indoor air with size and power advantages over macro-scale systems. The 44 mm{sup 3} preconcentrator extracts VOCs using highly adsorptive, granular forms of graphitized carbon black and carbon molecular sieves. The micron-sized silicon cavities have integrated heating and temperature sensing allowing low power, yet rapid heating to thermally desorb the collected VOCs (GC injection). The keys to device construction are a new adsorbent-solvent filling technique and solvent-tolerant wafer-level silicon-gold eutectic bonding technology. The product is the first granular adsorbent preconcentrator integrated at the wafer level. Other advantages include exhaustive VOC extraction and injection peak widths an order of magnitude narrower than predecessor prototypes. A mass transfer model, the first for any microscale preconcentrator, is developed to describe both adsorption and desorption behaviors. The physically intuitive model uses implicit and explicit finite differences to numerically solve the required partial differential equations. The model is applied to the adsorption and desorption of decane at various concentrations to extract Langmuir adsorption isotherm parameters from effluent curve …
Date: September 1, 2007
Creator: Robinson, Alex Lockwood (Advanced Sensor Technologies, Albuquerque, NM) & Chan, Helena Kai Lun
Object Type: Report
System: The UNT Digital Library
glideinWMS - A generic pilot-based Workload Management System (open access)

glideinWMS - A generic pilot-based Workload Management System

The Grid resources are distributed among hundreds of independent Grid sites, requiring a higher level Workload Management System (WMS) to be used efficiently. Pilot jobs have been used for this purpose by many communities, bringing increased reliability, global fair share and just in time resource matching. GlideinWMS is a WMS based on the Condor glidein concept, i.e. a regular Condor pool, with the Condor daemons (startds) being started by pilot jobs, and real jobs being vanilla, standard or MPI universe jobs. The glideinWMS is composed of a set of Glidein Factories, handling the submission of pilot jobs to a set of Grid sites, and a set of VO Frontends, requesting pilot submission based on the status of user jobs. This paper contains the structural overview of glideinWMS as well as a detailed description of the current implementation and the current scalability limits.
Date: September 1, 2007
Creator: Sfiligoi, Igor
Object Type: Article
System: The UNT Digital Library