LITERATURE SURVEY FOR GROUNDWATER TREATMENT OPTIONS FOR NITRATE IODINE-129 AND URANIUM 200-ZP-1 OPERABLE UNIT HANFORD SITE (open access)

LITERATURE SURVEY FOR GROUNDWATER TREATMENT OPTIONS FOR NITRATE IODINE-129 AND URANIUM 200-ZP-1 OPERABLE UNIT HANFORD SITE

This literature review presents treatment options for nitrate, iodine-129, and uranium, which are present in groundwater at the 200-ZP-I Groundwater Operable Unit (OU) within the 200 West Area of the Hanford Site. The objective of this review is to determine available methods to treat or sequester these contaminants in place (i.e., in situ) or to pump-and-treat the groundwater aboveground (i.e., ex situ). This review has been conducted with emphasis on commercially available or field-tested technologies, but theoretical studies have, in some cases, been considered when no published field data exist. The initial scope of this literature review included only nitrate and iodine-I 29, but it was later expanded to include uranium. The focus of the literature review was weighted toward researching methods for treatment of nitrate and iodine-129 over uranium because of the relatively greater impact of those compounds identified at the 200-ZP-I OU.
Date: June 5, 2008
Creator: ME, BYRNES
Object Type: Report
System: The UNT Digital Library
AN INTEGRATED RELAP5-3D AND MUTLIPHASE CFD CODE SYSTEM UTILIZING A SEMI-implicit coupling technique (open access)

AN INTEGRATED RELAP5-3D AND MUTLIPHASE CFD CODE SYSTEM UTILIZING A SEMI-implicit coupling technique

An integrated code system consisting of RELAP5-3D and a multiphase CFD program has been created through the use of a generic semi-implicit coupling algorithm. Unlike previous CFD coupling work, this coupling scheme is numerically stable provided the material Courant limit is not violated in RELAP5-3D or at the coupling locations. The basis for the coupling scheme and details regarding the unique features associated with the application of this technique to a four-field CFD program are presented. Finally, the results of a verification problem are presented. The coupled code system is shown to yield accurate and numerically stable results.
Date: September 5, 2001
Creator: Aumiller, D.L., Tomlinson, E.T., and Weaver, W.L.
Object Type: Report
System: The UNT Digital Library
Employee Handbook (open access)

Employee Handbook

Welcome to Berkeley Lab. You are joining or are already a part of a laboratory with a sterling tradition of scientific achievement, including eleven Nobel Laureates and thirteen National Medal of Science winners. No matter what job you do, you make Berkeley Lab the outstanding organization that it is. Without your hard work and dedication, we could not achieve all that we have. We value you and thank you for choosing to be part of our community. This Employee Handbook is designed to help you navigate the Lab. With over 3,000 employees, an additional 3,000 guests visiting from countries around the world, a 200-acre campus and many policies and procedures, learning all the ins and outs may seem overwhelming, especially if you're a new employee. However, even if you have been here for a while, this Handbook should be a useful reference tool. It is meant to serve as a guide, highlighting and summarizing what you need to know and informing you where you can go for more detailed information. The general information provided in this Handbook serves only as a brief description of many of the Lab's policies. Policies, procedures and information are found in the Lab's Regulations and …
Date: September 5, 2008
Creator: Bello, Madelyn
Object Type: Report
System: The UNT Digital Library
Pressure-Induced Electronic Spin Transition of Iron in Magnesiow?stite-(Mg,Fe)O (open access)

Pressure-Induced Electronic Spin Transition of Iron in Magnesiow?stite-(Mg,Fe)O

An electronic transition of iron in magnesiowuestite has been studied with synchrotron Moessbauer and X-ray emission spectroscopies under high pressures. Synchrotron Moessbauer studies show that the quadrupole splitting disappears and the isomer shift drops significantly across the spin-paring transition of iron in (Mg{sub 0.75},Fe{sub 0.25})O between 62 and 70 GPa, whereas X-ray emission spectroscopy of the Fe-K{sub {beta}} fluorescence lines in dilute (Mg{sub 0.95},Fe{sub 0.05})O also confirms that a high-spin to low-spin transition occurs between 46 GPa and 55 GPa. Based upon current results and percolation theory, we reexamine the high-pressure phase diagram of (Mg,Fe)O and find that iron-iron exchange interaction plays an important role in stabilizing the high-spin state of iron in FeO-rich (Mg,Fe)O.
Date: October 5, 2005
Creator: Lin, J. F.; Gavriliuk, A. G.; Struzhkin, V. V.; Jacobsen, S. D.; Sturhahn, W.; Hu, M. Y. et al.
Object Type: Article
System: The UNT Digital Library
ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM- 2007 (open access)

ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM- 2007

Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. The 2007 inspection program revealed that the structural integrity and waste confinement capability of the Savannah River Site waste tanks were maintained. A very small amount of material had seeped from Tank 12 from a previously identified leaksite. The material observed had dried on the tank wall and did not reach the annulus floor. A total of 5945 photographs were made and 1221 visual and video inspections were performed during 2007. Additionally, ultrasonic testing was performed on four Waste Tanks (15, 36, 37 and 38) in accordance with approved inspection plans that met the requirements of WSRC-TR-2002- 00061, Revision 2 'In-Service Inspection Program for High Level Waste Tanks'. The Ultrasonic Testing (UT) In-Service Inspections (ISI) are documented in a separate report that is prepared by the ISI programmatic Level III UT Analyst. Tanks 15, 36, 37 and 38 are documented in 'Tank Inspection NDE Results for Fiscal Year 2007'; WSRC-TR-2007-00064.
Date: June 5, 2008
Creator: West, B & Ruel Waltz, R
Object Type: Report
System: The UNT Digital Library
Non-magnetic compensation in ferromagnetic Ga1-xMnxAs and Ga1-xMnxP synthesized by ion implantation and pulsed-laser melting (open access)

Non-magnetic compensation in ferromagnetic Ga1-xMnxAs and Ga1-xMnxP synthesized by ion implantation and pulsed-laser melting

The electronic and magnetic effects of intentional compensation with non-magnetic donors are investigated in the ferromagnetic semiconductors Ga1-xMnxAs and Ga1-xMnxP synthesized using ion implantation and pulsed-laser melting (II-PLM). It is demonstrated that compensation with non-magnetic donors and MnI have similarqualitative effects on materials properties. With compensation TC decreases, resistivity increases, and stronger magnetoresistance and anomalous Hall effect attributed to skew scattering are observed. Ga1-xMnxAs can be controllably compensated with Te through a metal-insulator transition through which the magnetic and electrical properties vary continuously. The resistivity of insulating Ga1-xMnxAs:Te can be described by thermal activation to the mobility edge and simply-activated hopping transport. Ga1-xMnxP doped with S is insulating at all compositions but shows decreasing TC with compensation. The existence of a ferromagnetic insulating state in Ga1-xMnxAs:Te and Ga1-xMnxP:S having TCs of the same order as the uncompensated materials demonstrates that localized holes are effective at mediating ferromagnetism in ferromagnetic semiconductors through the percolation of ferromagnetic 'puddles' which at low temperatures.
Date: February 5, 2008
Creator: Scarpulla, M. A.; Stone, P. R.; Sharp, I. D.; Haller, E. E.; Dubon, O. D.; Beeman, J. W. et al.
Object Type: Article
System: The UNT Digital Library
Assessment of Unabated Facility Emission Potentials for Evaluating Airborne Radionuclide Monitoring Requirements at Pacific Northwest National Laboratory - 2003 (open access)

Assessment of Unabated Facility Emission Potentials for Evaluating Airborne Radionuclide Monitoring Requirements at Pacific Northwest National Laboratory - 2003

Assessments were performed to evaluate compliance with the airborne radionuclide emission monitoring requirements in the National Emission Standards for Hazardous Air Pollutants (NESHAP - U.S. Code of Federal Regulations, Title 40, Part 61, Subpart H) and Washington Administrative Code (WAC) 246-247: Radiation Protection - Air Emissions. In these assessments, potential unabated offsite doses were evaluated for emission locations at facilities owned by the U.S. Department of Energy and operated by Pacific Northwest National Laboratory (PNNL) on the Hanford Site. This report describes the inventory-based methods and provides the results for the assessment performed in 2003.
Date: December 5, 2003
Creator: Ballinger, Marcel Y.; Sula, Monte J.; Gervais, Todd L. & Edwards, Daniel L.
Object Type: Report
System: The UNT Digital Library
Charm Mixing at BaBar (open access)

Charm Mixing at BaBar

We report on searches for D{sup 0}-{bar D}{sup 0} mixing using decay-time distributions of D{sup 0} {yields} K{pi} and D{sup 0} {yields} K{sup (*)}e{nu} decays and a lifetime ratio analysis of D{sup 0} {yields} K{sup +}K{sup -}, {pi}{sup +}{pi}{sup -} decays using 91 fb{sup -1} of e{sup +}e{sup -} data taken at the PEP-II asymmetric-energy storage ring at energies near 10.6 GeV. Searches for CP-violation in D{sup 0} mixing and decay are also reported, as well as a measurement of R{sub D}, the ratio of the doubly Cabibbo-suppressed decay rate to the Cabibbo-allowed decay rate.
Date: July 5, 2006
Creator: Cowan, Ray F.
Object Type: Article
System: The UNT Digital Library
Quadratic function approaching method for magnetotelluric soundingdata inversion (open access)

Quadratic function approaching method for magnetotelluric soundingdata inversion

The quadratic function approaching method (QFAM) is introduced for magnetotelluric sounding (MT) data inversion. The method takes the advantage of that quadratic function has single extreme value, which avoids leading to an inversion solution for local minimum and ensures the solution for global minimization of an objective function. The method does not need calculation of sensitivity matrix and not require a strict initial earth model. Examples for synthetic data and field measurement data indicate that the proposed inversion method is effective.
Date: April 5, 2004
Creator: Liangjun, Yan; Wenbao, Hu & Zhang, Keni
Object Type: Article
System: The UNT Digital Library
TREATMENT OF PLUTONIUM- AND URANIUM-CONTAMINATED OIL FROM ROCKY FLATS ENVIRONMENTAL TECHNOLOGY SITE (open access)

TREATMENT OF PLUTONIUM- AND URANIUM-CONTAMINATED OIL FROM ROCKY FLATS ENVIRONMENTAL TECHNOLOGY SITE

A removal method for plutonium and uranium has been tested at the Rocky Flats Environmental Technology Site (RFETS). This alternative treatment technology is applicable to U.S. Department of Energy (DOE) organics (mainly used pump oil) contaminated with actinides. In our studies, greater than 70% removal of the actinides was achieved. The technology is based on contacting the oil with a sorbent powder consisting of a surface modified mesoporous material. The SAMMS (Self-Assembled Monolayers on Mesoporous Support) technology was developed by the Pacific Northwest National Laboratory for removal and stabilization of RCRA (i.e., lead, mercury, cadmium, silver, etc.) and actinides in water and for removal of mercury from organic solvents [1, 2]. The SAMMS material is based on self-assembly of functionalized monolayers on mesoporous oxide surfaces. The unique mesoporous oxide support provides a high surface area, thereby enhancing the metal-loading capacity. The testing described in this report was conducted on a small scale but larger-scale testing of the technology has been performed on mercury-contaminated oil without difficulty [3].
Date: December 5, 2002
Creator: Klasson, K. T.
Object Type: Report
System: The UNT Digital Library
US Activities in the Development of Plasma-Based X-ray Lasers (open access)

US Activities in the Development of Plasma-Based X-ray Lasers

None
Date: October 5, 2005
Creator: Dunn, J
Object Type: Article
System: The UNT Digital Library
Application of a New Method for Analyzing Images: Two-Dimensional Non-Linear Additive Decomposition (open access)

Application of a New Method for Analyzing Images: Two-Dimensional Non-Linear Additive Decomposition

This paper documents the application of a new image processing algorithm, two-dimensional non-linear additive decomposition (NLAD), which is used to identify regions in a digital image whose gray-scale (or color) intensity is different than the surrounding background. Standard image segmentation algorithms exist that allow users to segment images based on gray-scale intensity and/or shape. However, these processing techniques do not adequately account for the image noise and lighting variation that typically occurs across an image. NLAD is designed to separate image noise and background from artifacts thereby providing the ability to consistently evaluate images. The decomposition techniques used in this algorithm are based on the concepts of mathematical morphology. NLAD emulates the human capability of visually separating an image into different levels of resolution components, denoted as ''coarse'', ''fine'', and ''intermediate''. Very little resolution information overlaps any two of the component images. This method can easily determine and/or remove trends and noise from an image. NLAD has several additional advantages over conventional image processing algorithms, including no need for a transformation from one space to another, such as is done with Fourier transforms, and since only finite summations are required, the calculational effort is neither extensive nor complicated.
Date: July 5, 2006
Creator: Zaccaria, M. A.; Drudnoy, D. M. & Stasenko, J. E.
Object Type: Article
System: The UNT Digital Library
3D-Simulation Studies of SNS Ring Doublet Magnets (open access)

3D-Simulation Studies of SNS Ring Doublet Magnets

The accumulator ring of the Spallation Neutron Source (SNS) at ORNL employs in its straight sections closely packed quadrupole doublemagnets with large aperture of R=15.1 cm an relatively short iron-to-iron distance of 51.4 cm. These quads have much extended fringe field, and magnetic interferences among them in the doublet assemblies is not avoidable. Though each magnet in the assemblies has been individually mapped to high accuracy of lower than 0.01 percent level, the experimental data including the magnetic interference effect will not be available. We have performed 3D computing simulations on a quadrupole doublet model in order to assess the degree of the interference and to obtain relevant data for the SNS commissioning and operation.
Date: May 5, 2005
Creator: Wang, J. G.; N., Tsoupas & Venturini, M.
Object Type: Article
System: The UNT Digital Library
Visual Spreadsheets in VisIt (open access)

Visual Spreadsheets in VisIt

The VACET team would like to add visual spreadsheeting capability to the visualization tool VisIt, to make it be a viable tool for current users of AMRVis and ChomboVis. This document describes AMRVis and ChomboVis approaches to visual spreadsheets and describes a proposed visual spreadsheet mechanism for VisIt.
Date: February 5, 2007
Creator: Whitlock, B & Childs, H
Object Type: Report
System: The UNT Digital Library
Supernova Science Center (open access)

Supernova Science Center

The Supernova Science Center (SNSC) was founded in 2001 to carry out theoretical and computational research leading to a better understanding of supernovae and related transients. The SNSC, a four-institutional collaboration, included scientists from LANL, LLNL, the University of Arizona (UA), and the University of California at Santa Cruz (UCSC). Intitially, the SNSC was funded for three years of operation, but in 2004 an opportunity was provided to submit a renewal proposal for two years. That proposal was funded and subsequently, at UCSC, a one year no-cost extension was granted. The total operational time of the SNSC was thus July 15, 2001 - July 15, 2007. This document summarizes the research and findings of the SNSC and provides a cummulative publication list.
Date: May 5, 2008
Creator: Woosley, S. E.
Object Type: Report
System: The UNT Digital Library
Intelligent Control via Wireless Sensor Networks for Advanced Coal Combustion Systems (open access)

Intelligent Control via Wireless Sensor Networks for Advanced Coal Combustion Systems

Numerical Modeling of Solid Gas Flow, System Identification for purposes of modeling and control, and Wireless Sensor and Actor Network design were pursued as part of this project. Time series input-output data was obtained from NETL's Morgantown CFB facility courtesy of Dr. Lawrence Shadle. It was run through a nonlinear kernel estimator and nonparametric models were obtained for the system. Linear and first-order nonlinear kernels were then utilized to obtain a state-space description of the system. Neural networks were trained that performed better at capturing the plant dynamics. It is possible to use these networks to find a plant model and the inversion of this model can be used to control the system. These models allow one to compare with physics based models whose parameters can then be determined by comparing them against the available data based model. On a parallel track, Dr. Kumar designed an energy-efficient and reliable transport protocol for wireless sensor and actor networks, where the sensors could be different types of wireless sensors used in CFB based coal combustion systems and actors are more powerful wireless nodes to set up a communication network while avoiding the data congestion. Dr. Ahmadi's group studied gas solid flow in …
Date: August 5, 2007
Creator: Behal, Aman; Kumar, Sunil & Ahmadi, Goodarz
Object Type: Report
System: The UNT Digital Library
FULL-SCALE COLD CRUCIBLE TEST ON VITRIFICATION OF SAVANNAH RIVER SITE SB4 HLW SURROGATE (open access)

FULL-SCALE COLD CRUCIBLE TEST ON VITRIFICATION OF SAVANNAH RIVER SITE SB4 HLW SURROGATE

The full-scale cold crucible test on vitrification of sludge batch 4 (SB4) Savannah River Site HLW surrogate using a 418 mm inner diameter stainless steel crucible was carried-out for 66 hrs. Commercially available Frit 503-R4 (8 wt.% Li{sub 2}O, 16 wt.% B{sub 2}O{sub 3}, 76 wt.% SiO{sub 2}) was used as a glass forming additive at a calcine to frit ratio of 1:1 (50 wt.% calcine, 50 wt.% frit). Two portions of slurry prepared from frit and mixture of chemicals simulating waste in amount of {approx}750 kg and from frit and waste surrogate prepared by the SRT-MST-2007-00070 procedure in amount of {approx}1,300 kg with water content of {approx}27 and {approx}50 wt.%, respectively, was processed and {approx}875 kg of the vitrified product in total ({approx}415 + 460 kg) was obtained. Average parameters were as follows: vibration power - 121.6 to 134.1 kW, feed rate (capacity) - 25.1 to 39.8 kg/hr, glass pour rate (productivity) - 14.0 kg/hr specific energy expenses for feed processing - 4.8 to 3.4 kW x hr/kg, specific energy expenses for glass production (melting ratio) - 8.7 to 9.6 kW x hr/kg, specific glass productivity - 2453 kg/(m{sup 2} x d). The product was composed of major vitreous …
Date: August 5, 2008
Creator: Marra, J
Object Type: Article
System: The UNT Digital Library
Design and Certification of Targets for Drop Tests at the NTRC Packaging Research Facility (open access)

Design and Certification of Targets for Drop Tests at the NTRC Packaging Research Facility

This report provides documentation of the design and certification of drop pad (targets) at the National Transportation Research Center (NTRC) Packaging Research Facility(PRF). Based on the evaluation performed, it has been demonstrated that the small (interior) drop pad (target) meets the regulatory definition of a flat, essentially unyielding, horizontal surface for packages weighing up to 3,150 lb (1,432 kg). The large (exterior) drop pad (target) meets the regulatory definition of a flat, essentially unyielding, horizontal surface for packages weighing up to 28,184 lb (12,811 kg).
Date: June 5, 2003
Creator: Ludwig, S. B.
Object Type: Report
System: The UNT Digital Library
Measurement of the Spin of the Omega- Hyperon at Babar (open access)

Measurement of the Spin of the Omega- Hyperon at Babar

A measurement of the spin of the {Omega}{sup -} hyperon produced through the exclusive process {Xi}{sub c}{sup 0} {yields} {Omega}{sup -}K{sup +} is presented using a total integrated luminosity of 116 fb{sup -1} recorded with the BABAR detector at the e{sup +}e{sup -} asymmetric-energy B-Factory at SLAC. Under the assumption that the {Xi}{sub c}{sup 0} has spin 1/2, the angular distribution of the {Lambda} from {Omega}{sup -} {yields} {Lambda}K{sup -} decay is inconsistent with all half-integer {Omega}{sup -} spin values other than 3/2. Lower statistics data for the process {Omega}{sub c}{sup 0} {yields} {Omega}{sup -}{pi}{sup +} from a 230 fb{sup -1} sample are also found to be consistent with {Omega}{sup -} spin 3/2. If the {Xi}{sub c}{sup 0} spin were 3/2, an {Omega}{sup -} spin of 5/2 cannot be excluded.
Date: July 5, 2006
Creator: Aubert, B.
Object Type: Article
System: The UNT Digital Library
14C/C measurements support Andreev's internode method to determine lichen growth rates in Cladina stygia (Fr.) Ahti (open access)

14C/C measurements support Andreev's internode method to determine lichen growth rates in Cladina stygia (Fr.) Ahti

Growth rates and the ability to date an organism can greatly contribute to understanding its population biology and community dynamics. 1n 1954, Andreev proposed a method to date Cladina, a fruticose lichen, using total thallus length and number of internodes. No research, however, has demonstrated the reliability of this technique or compared its estimates to those derived by other means. In this study, we demonstrate the utility of {sup 14}C/C ratios to determine lichen age and growth rate in Cladina stygia (Fr.) Ahti collected from northwestern Alaska, USA. The average growth rate using {sup 14}C/C ratios was 6.5 mm {center_dot} yr{sup -1}, which was not significantly different from growth rates derived by Andreev's internode method (average = 6.2 mm {center_dot} yr{sup -1}); thus, suggesting the reliability of Andreev's simple field method for dating lichens. In addition, we found lichen growth rates appeared to differ with geographic location, yet did not seem related to ambient temperature and total precipitation.
Date: December 5, 2007
Creator: Holt, E. & Bench, G.
Object Type: Article
System: The UNT Digital Library
The radiative influence of aerosol effects on liquid-phase cumulusclouds based on sensitivity studies with two climate models (open access)

The radiative influence of aerosol effects on liquid-phase cumulusclouds based on sensitivity studies with two climate models

None
Date: October 5, 2005
Creator: Menon, Surabi & Rotstayn, Leon
Object Type: Article
System: The UNT Digital Library
An Independent Measurement of the Total Active 8B Solar Neutrino Flux Using an Array of 3He Proportional Counters at the Sudbury Neutrino Observatory (open access)

An Independent Measurement of the Total Active 8B Solar Neutrino Flux Using an Array of 3He Proportional Counters at the Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory (SNO) used an array of {sup 3}He proportional counters to measure the rate of neutral-current interactions in heavy water and precisely determined the total active ({nu}{sub x}) {sup 8}B solar neutrino flux. This technique is independent of previous methods employed by SNO. The total flux is found to be 5.54{sub -0.31}{sup +0.33}(stat){sub -0.34}{sup +0.36}(syst) x 10{sup 6} cm{sup -2}s{sup -1}, in agreement with previous measurements and standard solar models. A global analysis of solar and reactor neutrino results yields {Delta}m{sup 2} = 7.94{sub -0.26}{sup +0.42} x 10{sup -5} eV{sup 2} and {theta} = 33.8{sub -1.3}{sup +1.4} degrees. The uncertainty on the mixing angle has been reduced from SNO's previous results.
Date: June 5, 2008
Creator: Colla, SNO
Object Type: Article
System: The UNT Digital Library
CHARACTERIZATION OF VITRIFIED SAVANNAH RIVER SITE SB4 WASTE SURROGATE PRODUCED IN COLD CRUCIBLE (open access)

CHARACTERIZATION OF VITRIFIED SAVANNAH RIVER SITE SB4 WASTE SURROGATE PRODUCED IN COLD CRUCIBLE

Savannah River Site (SRS) sludge batch 4 (SB4) waste surrogate with high aluminum and iron content was vitrified with commercially available Frit 503-R4 (8 wt.% Li{sub 2}O, 16 wt.% B2O3, 76 wt.% SiO{sub 2}) by cold crucible inductive melting using lab- (56 mm inner diameter), bench- (236 mm) and large-scale (418 mm) cold crucible. The waste loading ranged between 40 and 60 wt.%. The vitrified products obtained in the lab-scale cold crucible were nearly amorphous with traces of unreacted quartz in the product with 40 wt.% waste loading and traces of spinel phase in the product with 50 wt.% waste loading. The glassy products obtained in the bench-scale cold crucible are composed of major vitreous and minor iron-rich spinel phase whose content at {approx}60 wt.% waste loading may achieve {approx}10 vol.%. The vitrified waste obtained in the large-scale cold crucible was also composed of major vitreous and minor spinel structure phases. No nepheline phase has been found. Average degree of crystallinity was estimated to be {approx}12 vol.%. Anionic motif of the glass network is built from rather short metasilicate chains and boron-oxygen constituent based on boron-oxygen triangular units.
Date: August 5, 2008
Creator: Marra, J
Object Type: Article
System: The UNT Digital Library
FUNCTIONALIZED LATERAL SURFACE COATED LASERS FOR CHEM-BIO DETECTION (open access)

FUNCTIONALIZED LATERAL SURFACE COATED LASERS FOR CHEM-BIO DETECTION

We present a class of compact, monolithic, photonic sensors consisting of multiple section edge emitting lasers with functionalized lateral surface coatings for low level detection of chemical or biological agents. Specifically, we discuss 8 {micro}m x 250 {micro}m Pd-coated H{sub 2} sensors and configurations to reduce the minimum detection limit from 138ppm for passive sensors to 1ppm for active sensors. Compared with conventional optical H{sub 2} sensors that use fiber gratings, surface plasmon resonances, or surface reflectance, our sensors offer the advantages of smaller size, wider dynamic range, monolithic integration of laser source and detector, and 2-D scalability to arrays of sensors that are functionalized to detect different agents.
Date: July 5, 2007
Creator: Goddard, L L; Bond, T C; Cole, G D & Behymer, E M
Object Type: Article
System: The UNT Digital Library