5000 groove/mm multilayer-coated blazed grating with 33percent efficiency in the 3rd order in the EUV wavelength range (open access)

5000 groove/mm multilayer-coated blazed grating with 33percent efficiency in the 3rd order in the EUV wavelength range

We report on recent progress in developing diffraction gratings which can potentially provide extremely high spectral resolution of 105-106 in the EUV and soft x-ray photon energy ranges. Such a grating was fabricated by deposition of a multilayer on a substrate which consists ofa 6-degree blazed grating with a high groove density. The fabrication of the substrate gratings was based on scanning interference lithography and anisotropic wet etch of silicon single crystals. The optimized fabrication process provided precise control of the grating periodicity, and the grating groove profile, together with very short anti-blazed facets, and near atomically smooth surface blazed facets. The blazed grating coated with 20 Mo/Si bilayers demonstrated a diffraction efficiency in the third order as high as 33percent at an incidence angle of 11? and wavelength of 14.18 nm.
Date: July 7, 2009
Creator: Lawrence Berkeley National Laboratory. Advanced Light Source.
Object Type: Article
System: The UNT Digital Library
Binary pseudo-random gratings and arrays for calibration of the modulation transfer function of surface profilometers: recent developments (open access)

Binary pseudo-random gratings and arrays for calibration of the modulation transfer function of surface profilometers: recent developments

The major problem of measurement of a power spectral density (PSD) distribution of the surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF tends to distort the PSD at higher spatial frequencies. It has been suggested [Proc. SPIE 7077-7, (2007), Opt. Eng. 47 (7), 073602-1-5 (2008)] that the instrumental MTF of a surface profiler can be precisely measured using standard test surfaces based on binary pseudo-random (BPR) patterns. In the cited work, a one dimensional (1D) realization of the suggested method based on use of BPR gratings has been demonstrated. Here, we present recent achievements made in fabricating and using two-dimensional (2D) BPR arrays that allow for a direct 2D calibration of the instrumental MTF. The 2D BPRAs were used as standard test surfaces for 2D MTF calibration of the MicromapTM-570 interferometric microscope with all available objectives. The effects of fabrication imperfections on the efficiency of calibration are also discussed.
Date: July 7, 2009
Creator: Barber, Samuel K.; Soldate, Paul; Anderson, Erik H.; Cambie, Rossana; Marchesini, Stefano; McKinney, Wanye R. et al.
Object Type: Article
System: The UNT Digital Library
Cellulose Synthesizing Complexes in Vascular Plants and Procaryotes (open access)

Cellulose Synthesizing Complexes in Vascular Plants and Procaryotes

Continuing the work initiated under DE-FG03-94ER20145, the following major accomplishments were achieved under DE-FG02-03ER15396 from 2003-2007: (a) we purified the acsD gene product of the Acetobacter cellulose synthase operon as well as transferred the CesA cellulose gene from Gossypium into E. coli in an attempt to crystallize this protein for x-ray diffraction structural analysis; however, crystallization attempts proved unsuccessful; (b) the Acetobacter cellulose synthase operon was successfully incorporated into Synechococcus, a cyanobacterium2; (c) this operon in Synechococcus was functionally expressed; (d) we successfully immunolabeled Vigna cellulose and callose synthase components and mapped their distribution before and after wounding; (e) we developed a novel method to produce replicas of cellulose synthases in tobacco BY-2 cells, and we demonstrated the cytoplasmic domain of the rosette TC; (f) from the moss Physcomitrella, we isolated two full-length cDNA sequences of cellulose synthase (PpCesA1 and PpCesA2) and attempted to obtain full genomic DNA sequences; (g) we examined the detailed molecular structure of a new form of non-crystalline cellulose known as nematic ordered cellulose (=NOC)3.
Date: July 7, 2009
Creator: Brown, Richard M., Jr. & Saxena, Inder Mohan
Object Type: Report
System: The UNT Digital Library
"Data Acquisition Systems" (open access)

"Data Acquisition Systems"

This project involved support for Lou Costrell and myself in the development of IEEE and IEC standards for nuclear counting and data acquisition systems. Over the years, as a result of this support, Lou and I were able to attend standards meetings of IEEE and IEC, which led directly to the publication of many standards for NIM systems, FastBus and CAMAC. We also chaired several writing committees as well as ANSI N42 (Nuclear instrumentation), IEEE NIM (NIM standard), IEEE NID (NPSS nuclear instruments and detector) and IEC TC45 WG9 (Nuclear instrumentation). Through this support we were able to assure that the interests of the US and DOE were expressed and implemented in the various standards.
Date: July 7, 2009
Creator: Unterweger, Michael & Costrell, Louis deceased
Object Type: Report
System: The UNT Digital Library
Design and Operation of a tunable MeV-level Compton-scattering-based (gamma-ray) source (open access)

Design and Operation of a tunable MeV-level Compton-scattering-based (gamma-ray) source

A mono-energetic gamma-ray (MEGa-ray) source based on Compton-scattering, targeting nuclear physics applications such as nuclear resonance fluorescence, has been constructed and commissioned at Lawrence Livermore National Laboratory. In this paper, the overall architecture of the system, as well as some of the critical design decisions made in the development of the source, are discussed. The performances of the two laser systems (one for electron production, one for scattering), the electron photoinjector, and the linear accelerator are also detailed, and initial {gamma}-ray results are presented.
Date: July 7, 2009
Creator: Gibson, D. J.; Albert, F.; Anderson, S. G.; Betts, S. M.; Messerly, M. J.; Phan, H. H. et al.
Object Type: Article
System: The UNT Digital Library
Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications (open access)

Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications

This report is the final technical report for DOE Program DE-FC36-04GO14301 titled “Direct Methanol Fuel Cell Prototype Demonstration for Consumer Electronics Applications”. Due to the public nature of this report some of the content reported in confidential reports and meetings to the DOE is not covered in detail in this report and some of the content has been normalized to not show actual values. There is a comparison of the projects accomplishments with the objectives, an overview of some of the key subsystem work, and a review of the three levels of prototypes demonstrated during the program. There is also a description of the eventual commercial product and market this work is leading towards. The work completed under this program has significantly increased the understanding of how Direct Methanol Fuel Cells (DMFC) can be deployed successfully to power consumer electronic devices. The prototype testing has demonstrated the benefits a direct methanol fuel cell system has over batteries typically used for powering consumer electronic devices. Three generations of prototypes have been developed and tested for performance, robustness and life. The technologies researched and utilized in the fuel cell stack and related subsystems for these prototypes are leveraged from advances in other …
Date: July 7, 2009
Creator: Carlstrom, Charles, M., Jr.
Object Type: Report
System: The UNT Digital Library
Early Transition Metal Oxides as Catalysts: Crossing Scales from Clusters to Single Crystals to Functioning Materials (open access)

Early Transition Metal Oxides as Catalysts: Crossing Scales from Clusters to Single Crystals to Functioning Materials

The overall goal of this program is to investigate the electronic structure and chemical bonding of early transition metal oxide clusters and use them as well-defined molecular models to obtain insight into properties and mechanisms of oxide catalysts, as well as to provide accurate spectroscopic and molecular information to verify theoretical methods used to predict materials properties. A laser vaporization cluster source is used to produce metal oxide clusters with different sizes, structures, and compositions. Well-defined inorganic polyoxometalate clusters in solution are transported in the gas phase using electrospray. Two state-of-the-art photoelectron spectroscopy apparatuses are used to interrogate the oxide clusters and polyoxometalate anions in the gas phase to obtain spectroscopic and electronic structure information. The experimental effort is assisted by theoretical calculations to understanding the structures, chemical bonding, and catalytical properties of the transition metal oxide clusters. The research approach combines novel and flexible experimental techniques and advanced theoretical/computational methodologies and seeks molecular-level information to aiding the design of new catalysts, as well as mechanistic understanding. We have focused on the investigation of tungsten oxide clusters containing three W atoms: W{sub 3}O{sub x}{sup -} (x = 7-11). A number of interesting findings have been made. We observed that the …
Date: July 7, 2009
Creator: Wang, Lai-Sheng
Object Type: Report
System: The UNT Digital Library
High pressure phase transformation in iron under fast compression (open access)

High pressure phase transformation in iron under fast compression

We present experimental results on the solid-solid, {alpha} to {epsilon} phase transformation kinetics of iron under high pressure dynamic compression. We observe kinetic features - velocity loops - similar with the ones recently reported to occur when water is frozen into its ice VII phase under comparable experimental conditions. We analyze this behavior in terms of general ideas coupling the steady sample compression with phase nucleation and growth with a pressure dependent phase interface velocity. The model is used to predict the response of iron when steadily driven across the {alpha} - {epsilon} phase boundary on very short time scales, including those envisioned to be achieved in ultra-fast laser experiments.
Date: July 7, 2009
Creator: Bastea, M; Bastea, S & Becker, R
Object Type: Article
System: The UNT Digital Library
Kinase Expression and Chromosomal Rearrangements in Papillary Thyroid Cancer Tissues: Investigations at the Molecular and Microscopic Levels (open access)

Kinase Expression and Chromosomal Rearrangements in Papillary Thyroid Cancer Tissues: Investigations at the Molecular and Microscopic Levels

Structural chromosome aberrations are known hallmarks of many solid tumors. In the papillary form of thyroid cancer (PTC), for example, activation of the receptor tyrosine kinase (RTK) genes, ret or the neurotrophic tyrosine kinase receptor type I (NTRK1) by intra- or interchromosomal rearrangements have been suggested as a cause of the disease. The 1986 accident at the nuclear power plant in Chernobyl, USSR, led to the uncontrolled release of high levels of radioisotopes. Ten years later, the incidence of childhood papillary thyroid cancer (chPTC) near Chernobyl had risen by two orders of magnitude. Tumors removed from some of these patients showed aberrant expression of the ret RTK gene due to a ret/PTC1 or ret/PTC3 rearrangement involving chromosome 10. However, many cultured chPTC cells show a normal G-banded karyotype and no ret rearrangement. We hypothesize that the 'ret-negative' tumors inappropriately express a different oncogene or have lost function of a tumor suppressor as a result of chromosomal rearrangements, and decided to apply molecular and cytogenetic methods to search for potentially oncogenic chromosomal rearrangements in Chernobyl chPTC cases. Knowledge of the kind of genetic alterations may facilitate the early detection and staging of chPTC as well as provide guidance for therapeutic intervention.
Date: July 7, 2009
Creator: Weier, Heinz-Ulrich; Kwan, Johnson; Lu, Chun-Mei; Ito, Yuko; Wang, Mei; Baumgartner, Adolf et al.
Object Type: Report
System: The UNT Digital Library
SBIR Phase I final Report (open access)

SBIR Phase I final Report

The approach that we propose here in this SBIR proposal is a modified water electrolysis cell. In conventional water electrolysis the H2O is split into electrons, protons, and oxygen gas at the anode electrode. The electrons travel through an external power source and the protons travel through an electrolyte membrane to the cathode where they recombine to form hydrogen gas. The power source requires a minimum of 1.23 V to overcome the potential difference of the electrodes for the splitting of water. In contrast in our approach proposed here, instead of splitting water we are using acetate in wastewater and bacteria to oxidize the acetate into electrons and protons at the anode surface. The microbes release the electrons to the anode and the resulting protons move to the cathode electrode through the proton exchange membrane as described above and recombine to form hydrogen gas. The advantage here is that the required potential is now on the order of 0.25 to 0.8 V, and a considerable savings in electricity is realized to produce the same amount of hydrogen while at the same time removing organic matter from wastewater streams. Significant improvements in current density needs to be made in order for …
Date: July 7, 2009
Creator: Grot, Stephen
Object Type: Report
System: The UNT Digital Library
The Shifting Landscape of Ratepayer-Funded Energy Efficiency in the U.S. (open access)

The Shifting Landscape of Ratepayer-Funded Energy Efficiency in the U.S.

None
Date: July 7, 2009
Creator: Barbose, G.; Goldman, C. & Schlegel, J.
Object Type: Article
System: The UNT Digital Library
Thermal Instability of Olivine-Type LiMnP04 Cathodes (open access)

Thermal Instability of Olivine-Type LiMnP04 Cathodes

The remarkable thermal stability of LiFePO{sub 4} and its charged counterpart, FePO{sub 4}, have been instrumental in its commercialization as a lithium ion battery cathode material. Despite the similarity in composition and structure, and despite the high thermal stability of the parent compound, LiMnPO{sub 4}, we find that the delithiated phase Li{sub y}MnPO{sub 4}, (which contains a small amount of residual lithium), is relatively unstable and reactive toward a lithium ion electrolyte. The onset temperature for heat evolution in the presence of 1M LiPF{sub 6} in 1:1 ethylene carbonate/propylene carbonate is around 150 C, and the total evolved heat is 884 J/g, comparable to that produced under similar conditions by charged LiCoO{sub 2} electrodes.
Date: July 7, 2009
Creator: Chen, Guoying & Richardson, Thomas J.
Object Type: Article
System: The UNT Digital Library
UCRLDetermination of the standard deviation on multiplication based on count distributions (open access)

UCRLDetermination of the standard deviation on multiplication based on count distributions

The multiplication M of a multiplying object can be determined by analyzing the arrival times of thermal neutrons in detectors such as helium tubes. A source emitting neutrons randomly will lead to neutron inter arrival times obeying Poisson process statistics. By observing how the inter arrival times of detected counts differ from Poisson statistics, one can assess properties of the neutron source such as the source intensity and multiplication. While the method of analyzing the inter arrival times of neutrons using count distributions to determine characteristics of the source has been used for a long time, the treatment of the errors on the determined quantities multiplication M and source strength S have not yet been adequately treated. This object of this report is to assess these errors.
Date: July 7, 2009
Creator: Verbeke, J
Object Type: Report
System: The UNT Digital Library
Analysis of Longitudinal Beam Dynamics Behavior and RF System Operative Limits at High Beam Currents in Storage Rings (open access)

Analysis of Longitudinal Beam Dynamics Behavior and RF System Operative Limits at High Beam Currents in Storage Rings

A dynamics simulation model is used to estimate limits of performance of the Positron-Electron Project (PEP-II). The simulation captures the dynamics and technical limitations of the Low Level Radio Frequency (LLRF) system, the high-power RF components and the low-order mode coupled bunch longitudinal beam dynamics. Simulation results showing the effect of non-linearities on the LLRF loops, and studies of the effectiveness of technical component upgrades are reported, as well as a comparison of these results with PEP-II measurements. These studies have led to the estimation of limits and determining factors in the maximum stored current that the Low Energy Ring/High Energy Ring (LER/HER) can achieve, based on system stability for different RF station configurations and upgrades. In particular, the feasibility of the PEP-II plans to achieve the final goal in luminosity, which required an increase of the beam currents to 4A for LER and 2.2A for HER, is studied. These currents are challenging in part because they would push the longitudinal low-order beam mode stability to the limit, and the klystron forward power past a level of satisfactory margin. An acceptable margin is defined in this paper, which in turn determines the corresponding klystron forward power limitation.
Date: July 7, 2008
Creator: Mastorides, T; Rivetta, C.; Fox, J. D.; Winkle, D. Van & Tytelman, D.
Object Type: Article
System: The UNT Digital Library
Dezentrale Energieversorgung mit Speichertechnologien (open access)

Dezentrale Energieversorgung mit Speichertechnologien

None
Date: July 7, 2008
Creator: Stadler, Michael; Stadler, Michael & Marnay, Chris
Object Type: Article
System: The UNT Digital Library
Final Technical Report (open access)

Final Technical Report

P. fluorescens PfO-1 is a soil bacterium isolated by this laboratory from sandy loam soil (4). Because of the importance of adhesion for persistence in natural environments, we utilized adherence to sand as an assay to screen a library of PfO-1 mutants for defects in adhesion. Three adhesion defective mutants, PfO-5, PfO-10, and PfO-15 were recovered. PfO-5 and PfO-10 had different insertions in the same gene, which we called adnA, and also showed motility defects (3). PfO-15 was motile, but was hyper-flagellated. The insertion was in a different gene, adnB, which shows similarity to mot genes involved in flagella functions (Strain and Levy, unpublished). These early studies demonstrated the important but separable requirements for flagella and motility in adherence. In a field study, the adnA mutant PfO-5 was less able to persist than the wildtype PfO-1 and did not spread as fast or as far from the point of inoculation as did PfO-1 (7), linking adhesion and soil fitness. DNA sequencing revealed that AdnA shares 82% identity with the flagella regulator FleQ from P. aeruginosa (3). FleQ is required for adhesion of P. aeruginosa to respiratory mucin, which is important for pathogenesis (1, 2). Using a gene fusion approach, seven …
Date: July 7, 2008
Creator: Stuart B. Levy, M.D.
Object Type: Report
System: The UNT Digital Library
Measurements and Analysis of Longitudinal HOM Driven Coupled Bunch Modes in PEP-II Rings (open access)

Measurements and Analysis of Longitudinal HOM Driven Coupled Bunch Modes in PEP-II Rings

The growth rates of the longitudinal higher-order impedance-driven beam modes have greatly increased since the initial PEP-II design and commissioning. This increase is attributed to the addition of 6 1.2MW RF stations with 8 accelerating cavities in the HER and 2 1.2MW RF stations with 4 accelerating cavities in the LER, which allowed operations at twice the design current and almost four times the luminosity. As a result, the damping requirements for the longitudinal feedback have greatly increased since the design, and the feedback filters and control schemes have evolved during PEP-II operations. In this paper, growth and damping rate data for the higher-order mode (HOM) driven coupled-bunch modes are presented from various PEP-II runs and are compared with historical estimates during commissioning. The effect of noise in the feedback processing channel is also studied. Both the stability and performance limits of the system are analyzed.
Date: July 7, 2008
Creator: Mastorides, T; Rivetta, C.; Fox, J. D. & Winkle, D. Van
Object Type: Article
System: The UNT Digital Library
Modeling and Simulation of the Longitudinal Beam Dynamics - RF Station Interaction in the LHC Rings (open access)

Modeling and Simulation of the Longitudinal Beam Dynamics - RF Station Interaction in the LHC Rings

A non-linear time-domain simulation has been developed to study the interaction between longitudinal beam dynamics and RF stations in the LHC rings. The motivation for this tool is to determine optimal LLRF configurations, to study system sensitivity on various parameters, and to define the operational and technology limits. It will be also used to study the effect of RF station noise, impedance, and perturbations on the beam life time and longitudinal emittance. It allows the study of alternative LLRF implementations and control algorithms. The insight and experience gained from our PEP-II simulation is important for this work. In this paper we discuss properties of the simulation tool that will be helpful in analyzing the LHC RF system and its initial results. Partial verification of the model with data taken during the LHC RF station commissioning is presented.
Date: July 7, 2008
Creator: Mastorides, T; Rivetta, C.; Fox, J. D.; Winkle, D.Van; Baudrenghien, P. & Tuckmantel, J.
Object Type: Article
System: The UNT Digital Library
The powers of deconfinement (open access)

The powers of deconfinement

The trace anomaly of gluodynamics encodes the breakdown of classical scale invariance due to interactions around the deconfinement phase transition. While it is expected that at high temperatures perturbation theory becomes applicable we show that current lattice calculations are far from the perturbative regime and are dominated instead by inverse even power corrections in the temperature, while the total perturbative contribution is estimated to be extremely small and compatible with zero within error bars. We provide an interpretation in terms of dimension-two gluon condensate of the dimensionally reduced theory which value agrees with a similar analysis of power corrections from available lattice data for the renormalized Polyakov loop and the heavy quark-antiquark free energy in the deconfined phase of QCD [1,2].
Date: July 7, 2008
Creator: Megias,E.; Ruiz Arriola, E.; Megias, E. & Salcedo, L.L.
Object Type: Article
System: The UNT Digital Library
Real Time Grid Reliability Management 2005 (open access)

Real Time Grid Reliability Management 2005

The increased need to manage California?s electricity grid in real time is a result of the ongoing transition from a system operated by vertically-integrated utilities serving native loads to one operated by an independent system operator supporting competitive energy markets. During this transition period, the traditional approach to reliability management -- construction of new transmission lines -- has not been pursued due to unresolved issues related to the financing and recovery of transmission project costs. In the absence of investments in new transmission infrastructure, the best strategy for managing reliability is to equip system operators with better real-time information about actual operating margins so that they can better understand and manage the risk of operating closer to the edge. A companion strategy is to address known deficiencies in offline modeling tools that are needed to ground the use of improved real-time tools. This project: (1) developed and conducted first-ever demonstrations of two prototype real-time software tools for voltage security assessment and phasor monitoring; and (2) prepared a scoping study on improving load and generator response models. Additional funding through two separate subsequent work authorizations has already been provided to build upon the work initiated in this project.
Date: July 7, 2008
Creator: Eto, Joe; Eto, Joe; Lesieutre, Bernard; Lewis, Nancy Jo & Parashar, Manu
Object Type: Report
System: The UNT Digital Library
RESULTS OF IONSIV® IE-95 STUDIES FOR THE REMOVAL OF RADIOACTIVE CESIUM FROM K-EAST BASIN SPENT NUCLEAR FUEL POOL DURING DECOMMISSIONING ACTIVITIES (open access)

RESULTS OF IONSIV® IE-95 STUDIES FOR THE REMOVAL OF RADIOACTIVE CESIUM FROM K-EAST BASIN SPENT NUCLEAR FUEL POOL DURING DECOMMISSIONING ACTIVITIES

This report delineates the results obtained from laboratory testing of IONISIV{reg_sign} IE-95 to determine the efficacy of the zeolite for the removal of radioactive cesium from the KE Basin water prior to transport to the Effluent Treatment Facility, as described in RPP-PLAN-36158, IONSIV{reg_sign} IE-95 Studies for the removal of Radioactive Cesium from KE Basin Spent Nuclear Fuel Pool during Decommissioning Activities. The spent nuclear fuel was removed from KE Basin and the remaining sludge was layered with a grout mixture consisting of 26% Lehigh Type I/II portland cement and 74% Boral Mohave type F fly ash with a water-to-cement ratio of 0.43. The first grout pour was added to the basin floor to a depth of approximately 14 in. covering an area of 12,000 square feet. A grout layer was also added to the sludge containers located in the attached Weasel and Technical View pits.
Date: July 7, 2008
Creator: JB, DUNCAN & SP, BURKE
Object Type: Report
System: The UNT Digital Library
Sunfall: a collaborative visual analytics system for astrophysics (open access)

Sunfall: a collaborative visual analytics system for astrophysics

Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.
Date: July 7, 2008
Creator: Aragon, Cecilia R.; Aragon, Cecilia R.; Bailey, Stephen J.; Poon, Sarah; Runge, Karl & Thomas, Rollin C.
Object Type: Article
System: The UNT Digital Library
Tank 241-an-102 Multi-Probe Corrosion Monitoring System Project Lessons Learned (open access)

Tank 241-an-102 Multi-Probe Corrosion Monitoring System Project Lessons Learned

During 2007 and 2008, a new Multi-Probe Corrosion Monitoring System (MPCMS) was designed and fabricated for use in double-shell tank 241-AN-102. The system was successfully installed in the tank on May 1, 2008. The 241-AN-102 MPCMS consists of one 'fixed' in-tank probe containing primary and secondary reference electrodes, tank material electrodes, Electrical Resistance (ER) sensors, and stressed and unstressed corrosion coupons. In addition to the fixed probe, the 241-AN-102 MPCMS also contains four standalone coupon racks, or 'removable' probes. Each rack contains stressed and unstressed coupons made of American Society of Testing and Materials A537 CL1 steel, heat-treated to closely match the chemical and mechanical characteristics of the 241-AN-102 tank wall. These coupon racks can be removed periodically to facilitate examination of the attached coupons for corrosion damage. Along the way to successful system deployment and operation, the system design, fabrication, and testing activities presented a number of challenges. This document discusses these challenges and lessons learned, which when applied to future efforts, should improve overall project efficiency.
Date: July 7, 2008
Creator: Taylor, T.; Hagensen, A. & Kirch, N. W.
Object Type: Report
System: The UNT Digital Library
Volatile Organic Compound Investigation Results, 300 Area, Hanford Site, Washington (open access)

Volatile Organic Compound Investigation Results, 300 Area, Hanford Site, Washington

Unexpectedly high concentrations of volatile organic compounds (VOC) were discovered while drilling in the unconfined aquifer beneath the Hanford Site’s 300 Area during 2006. The discovery involved an interval of relatively finer-grained sediment within the unconfined aquifer, an interval that is not sampled by routine groundwater monitoring. Although VOC contamination in the unconfined aquifer has been identified and monitored, the concentrations of newly discovered contamination are much higher than encountered previously, with some new results significantly higher than the drinking water standards. The primary contaminant is trichloroethene, with lesser amounts of tetrachloroethene. Both chemicals were used extensively as degreasing agents during the fuels fabrication process. A biological degradation product of these chemicals, 1,2-dichloroethene, was also detected. To further define the nature and extent of this contamination, additional characterization drilling was undertaken during 2007. Four locations were drilled to supplement the information obtained at four locations drilled during the earlier investigation in 2006. The results of the combined drilling indicate that the newly discovered contamination is limited to a relatively finer-grained interval of Ringold Formation sediment within the unconfined aquifer. The extent of this contamination appears to be the area immediately east and south of the former South Process Pond. Samples …
Date: July 7, 2008
Creator: Peterson, Robert E.; Williams, Bruce A. & Smith, Ronald M.
Object Type: Report
System: The UNT Digital Library