National Library of Energy BETA

Sample records for flat panel displays

  1. Microgap flat panel display

    DOE Patents [OSTI]

    Wuest, Craig R.

    1998-01-01

    A microgap flat panel display which includes a thin gas-filled display tube that utilizes switched X-Y "pixel" strips to trigger electron avalanches and activate a phosphor at a given location on a display screen. The panel utilizes the principal of electron multiplication in a gas subjected to a high electric field to provide sufficient electron current to activate standard luminescent phosphors located on an anode. The X-Y conductive strips of a few micron widths may for example, be deposited on opposite sides of a thin insulating substrate, or on one side of the adjacent substrates and function as a cathode. The X-Y strips are separated from the anode by a gap filled with a suitable gas. Electrical bias is selectively switched onto X and Y strips to activate a "pixel" in the region where these strips overlap. A small amount of a long-lived radioisotope is used to initiate an electron avalanche in the overlap region when bias is applied. The avalanche travels through the gas filled gap and activates a luminescent phosphor of a selected color. The bias is adjusted to give a proportional electron multiplication to control brightness for given pixel.

  2. Microgap flat panel display

    DOE Patents [OSTI]

    Wuest, C.R.

    1998-12-08

    A microgap flat panel display is disclosed which includes a thin gas-filled display tube that utilizes switched X-Y ``pixel`` strips to trigger electron avalanches and activate a phosphor at a given location on a display screen. The panel utilizes the principal of electron multiplication in a gas subjected to a high electric field to provide sufficient electron current to activate standard luminescent phosphors located on an anode. The X-Y conductive strips of a few micron widths may for example, be deposited on opposite sides of a thin insulating substrate, or on one side of the adjacent substrates and function as a cathode. The X-Y strips are separated from the anode by a gap filled with a suitable gas. Electrical bias is selectively switched onto X and Y strips to activate a ``pixel`` in the region where these strips overlap. A small amount of a long-lived radioisotope is used to initiate an electron avalanche in the overlap region when bias is applied. The avalanche travels through the gas filled gap and activates a luminescent phosphor of a selected color. The bias is adjusted to give a proportional electron multiplication to control brightness for given pixel. 6 figs.

  3. IBM's New Flat Panel Displays

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    by J. Stöhr (SSRL), M. Samant (IBM), J. Lüning (SSRL) Today's laptop computers utilize flat panel displays where the light transmission from the back to the front of the display is modulated by orientation changes in liquid crystal (LC) molecules. Details are discussed in Ref. 2 below. One of the key steps in the manufacture of the displays is the alignment of the LC molecules in the display. Today this is done by mechanical rubbing of two polymer surfaces and then sandwiching the LC between

  4. Sandia National Laboratories: Better flat-panel displays

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Facebook Twitter YouTube Flickr RSS News Better, brighter, cheaper flat-panel displays By ... colors and better images for flat-panel displays built from less expensive ...

  5. ELECTROLUMINESCENT MATERIAL FOR FLAT PANEL DISPLAY

    SciTech Connect (OSTI)

    Smith, D.B.

    2000-11-13

    The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop a new-generation electroluminescent (EL) material for flat panel displays and related applications by using unique and complementary research capabilities at Oak Ridge National Laboratory and OSRAM Sylvania, Inc. The goal was to produce an EL material with a luminance 10 times greater than conventional EL phosphors. An EL material with this increased luminance would have immediate applications for flat panel display devices (e.g., backlighting for liquid-crystal diodes) and for EL lamp technology. OSRAM Sylvania proposed that increased EL phosphor luminance could be obtained by creating composite EL materials capable of alignment under an applied electric field and capable of concentrating the applied electric field. Oak Ridge National Laboratory used pulsed laser deposition as a method for making these composite EL materials. The materials were evaluated for electroluminescence at laboratory facilities at OSRAM Sylvania, Inc. Many composite structures were thus made and evaluated, and it was observed that a composite structure based on alternating layers of a ferroelectric and a phosphor yielded electroluminescence. An enabling step that was not initially proposed but was conceived during the cooperative effort was found to be crucial to the success of the composite structure. The CRADA period expired before we were able to make quantitative measurements of the luminance and efficiency of the composite EL material. Future cooperative work, outside the scope of the CRADA, will focus on making these measurements and will result in the production of a prototype composite EL device.

  6. Flat panel ferroelectric electron emission display system

    DOE Patents [OSTI]

    Sampayan, Stephen E.; Orvis, William J.; Caporaso, George J.; Wieskamp, Ted F.

    1996-01-01

    A device which can produce a bright, raster scanned or non-raster scanned image from a flat panel. Unlike many flat panel technologies, this device does not require ambient light or auxiliary illumination for viewing the image. Rather, this device relies on electrons emitted from a ferroelectric emitter impinging on a phosphor. This device takes advantage of a new electron emitter technology which emits electrons with significant kinetic energy and beam current density.

  7. Flat panel ferroelectric electron emission display system

    DOE Patents [OSTI]

    Sampayan, S.E.; Orvis, W.J.; Caporaso, G.J.; Wieskamp, T.F.

    1996-04-16

    A device is disclosed which can produce a bright, raster scanned or non-raster scanned image from a flat panel. Unlike many flat panel technologies, this device does not require ambient light or auxiliary illumination for viewing the image. Rather, this device relies on electrons emitted from a ferroelectric emitter impinging on a phosphor. This device takes advantage of a new electron emitter technology which emits electrons with significant kinetic energy and beam current density. 6 figs.

  8. Flat or curved thin optical display panel

    DOE Patents [OSTI]

    Veligdan, J.T.

    1995-01-10

    An optical panel includes a plurality of waveguides stacked together, with each waveguide having a first end and an opposite second end. The first ends collectively define a first face, and the second ends collectively define a second face of the panel. The second face is disposed at an acute face angle relative to the waveguides to provide a panel which is relatively thin compared to the height of the second face. In an exemplary embodiment for use in a projection TV, the first face is substantially smaller in height than the second face and receives a TV image, with the second face defining a screen for viewing the image enlarged. 7 figures.

  9. Flat or curved thin optical display panel

    DOE Patents [OSTI]

    Veligdan, James T.

    1995-01-10

    An optical panel 10 includes a plurality of waveguides 12 stacked together, with each waveguide 12 having a first end 12a and an opposite second end 12b. The first ends 12a collectively define a first face 16, and the second ends 12b collectively define a second face 18 of the panel 10. The second face 18 is disposed at an acute face angle relative to the waveguides 12 to provide a panel 10 which is relatively thin compared to the height of the second face. In an exemplary embodiment for use in a projection TV, the first face 16 is substantially smaller in height than the second face 18 and receives a TV image, with the second face 18 defining a screen for viewing the image enlarged.

  10. Flat panel display development activities at Sandia National Laboratories

    SciTech Connect (OSTI)

    DiBello, E.G.; Worobey, W.; Burchett, S.; Hareland, W.; Felter, T.; Mays, B.

    1994-12-31

    The flat panel display development activities underway at Sandia National Laboratories are described. Research is being conducted in the areas of glass substrates, phosphors, large area processes, and electron emissions. Projects are focused on improving process yield, developing large area processes, and using modeling techniques to predict design performance.

  11. Diffractive optics for compact flat panel displays. Final report

    SciTech Connect (OSTI)

    Sweeney, D.; DeLong, K.

    1997-04-29

    Three years ago LLNL developed a practical method to dramatically reduce the chromatic aberration in single element diffractive imaging lenses. High efficiency, achromatic imaging lenses have been fabricated for human vision correction. This LDRD supported research in applying our new methods to develop a unique, diffraction-based optical interface with solid state, microelectronic imaging devices. Advances in microelectronics have led to smaller, more efficient components for optical systems. There have, however, been no equivalent advances in the imaging optics associated with these devices. The goal of this project was to replace the bulky, refractive optics in typical head-mounted displays with micro-thin diffractive optics to directly image flat-panel displays into the eye. To visualize the system think of the lenses of someone`s eyeglasses becoming flat-panel displays. To realize this embodiment, we needed to solve the problems of large chromatic aberrations and low efficiency that are associated with diffraction. We have developed a graceful tradeoff between chromatic aberrations and the diffractive optic thickness. It turns out that by doubling the thickness of a micro-thin diffractive lens we obtain nearly a two-times improvement in chromatic performance. Since the human eye will tolerate one diopter of chromatic aberration, we are able to achieve an achromatic image with a diffractive lens that is only 20 microns thick, versus 3 mm thickness for the comparable refractive lens. Molds for the diffractive lenses are diamond turned with sub-micron accuracy; the final lenses are cast from these molds using various polymers. We thus retain both the micro- thin nature of the diffractive optics and the achromatic image quality of refractive optics. During the first year of funding we successfully extended our earlier technology from 1 cm diameter optics required for vision applications up to the 5 cm diameter optics required for this application. 3 refs., 6 figs.

  12. Improving the diversity of manufacturing electroluminescent flat panel displays

    SciTech Connect (OSTI)

    Moss, T.S.; Samuels, J.A.; Smith, D.C.

    1995-09-01

    Crystalline calcium thiogallate with a cerium dopant has been deposited by metal-organic chemical vapor deposition (MOCVD) at temperatures below 600{degrees}C on a low cost glass substrate. An EL luminance of 1.05 fL was observed 40 volts above threshold at 60 Hz. This is more than an order of magnitude improvement over earlier crystalline-as-deposited thiogallate materials. These results pave the way for the use of MOCVD as a potential method for processing full color thin-film electroluminescent (TFEL) flat panel displays. The formation of the CaGa{sub 2}S{sub 4}:Ce phosphor requires precise control over a number of deposition parameters including flow rates, substrate temperature, and reactor pressure. The influence of these parameters will be discussed in terms of structure, uniformity, and TFEL device performance.

  13. Thiogallate Blue Phosphors for Thin Film Electroluminescent Flat Panel Displays

    SciTech Connect (OSTI)

    Dye, Robert C.; Tuenge, Richard T.

    1997-04-03

    This project helped to develop a metal-organic chemical vapor deposition (MOCVD) method that could improve the efficiency of the blue phosphor for full color thin-film electroluminescent (TFEL) flat panel displays. High quality SrS and SrS:Ce thin films were deposited from Sr(thd)2, Ce(thd)4 and H2S via a low pressure MOCVD process. Film characteristics were found to be insensitive to the presence of the cerium dopant in the concn. range investigated. Depositions were carried out for a wide temp. range (250-550°C). Deposition rates were found to be relatively insensitive for the temp. range investigated. The films produced were found to be highly cryst. at all temps. investigated. Deposited material showed texturing as a function of substrate material and temp. FWHM of the a 111 ii reflections were found to have a 2Q values of 0.15-0.18 deg. for all temps. RBS and AES shows stoichiometric 1 : 1 SrS with less than 2% carbon and oxygen contaminates. ERO indicates the films to have 1- 2.5% hydrogen. Films doped with 0.019-0.043 atom % Ce showed weak blue-green to green PL with increasing dopant concn. Doped films yielded up to 3.2 cd/m2 EL emission with CIE coordinates of x = 0.22 and y = 0.32 and turn-on voltages of 150-250 V.

  14. Flat panel display using Ti-Cr-Al-O thin film

    DOE Patents [OSTI]

    Jankowski, Alan F.; Schmid, Anthony P.

    2002-01-01

    Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  15. Method of forming a spacer for field emission flat panel displays

    SciTech Connect (OSTI)

    Bernhardt, A.F.; Contolini, R.J.

    1997-08-19

    Spacers are disclosed for applications such as field emission flat panel displays and vacuum microelectronics, and which involves the application of aerogel/xerogel technology to the formation of the spacer. In a preferred approach the method uses a mold and mold release agent wherein the gel precursor is a liquid which can be applied to the mold filling holes which expose the substrate (either the baseplate or the faceplate). A release agent is applied to the mold prior to precursor application to ease removal of the mold after formation of the dielectric spacer. The shrinkage of the gel during solvent extraction also improves mold removal. The final spacer material is a good dielectric, such as silica, secured to the substrate. 3 figs.

  16. Method of forming a spacer for field emission flat panel displays

    SciTech Connect (OSTI)

    Bernhardt, Anthony F.; Contolini, Robert J.

    1997-01-01

    Spacers for applications such as field emission flat panel displays and vacuum microelectronics, and which involves the application of aerogel/xerogel technology to the formation of the spacer. In a preferred approach the method uses a mold and mold release agent wherein the gel precursor is a liquid which can be applied to the mold filling holes which expose the substrate (either the baseplate or the faceplate). A release agent is applied to the mold prior to precursor application to ease removal of the mold after formation of the dielectric spacer. The shrinkage of the gel during solvent extraction also improves mold removal. The final spacer material is a good dielectric, such as silica, secured to the substrate.

  17. Multi-cusp ion source for doping process of flat panel display manufacturing

    SciTech Connect (OSTI)

    Inouchi, Yutaka Matsumoto, Takeshi; Dohi, Shojiro; Tanii, Masahiro; Takahashi, Genki; Nishimura, Ippei; Tatemichi, Junichi; Konishi, Masashi; Naito, Masao

    2014-02-15

    We developed a multi-cusp ion source for Nissin ion doping system iG5 which is used in low temperature poly-crystalline silicon processes for flat panel display (FPD) manufacturing. In this ion source, BF{sub 3} or PH{sub 3} diluted H{sub 2} plasmas are produced and large area ribbon ion beams are extracted. In general, ion ratio of B{sup +} in BF{sub 3} plasma is much smaller than BF{sub 2}{sup +} in multi-cusp ion sources. We developed a new method to increase B{sup +} ratio and obtained mass analyzed B{sup +} target current of 130 mA. We employed newly improved multi-slot type electrodes for the beam extraction system and obtained stable beams with the uniformity of below 3%. In BF{sub 3} plasmas, several undesirable metal fluorides are produced in the plasma chamber and deposited on the electrode system, which cause glitches and poor beam uniformity. We introduce several cleaning methods.

  18. Amorphous Diamond Flat Panel Displays - Final Report of ER-LTR CRADA project with SI Diamond Technology

    SciTech Connect (OSTI)

    Ager III, Joel W.

    1998-05-08

    The objective of this project was to determine why diamond-based films are unusually efficient electron emitters (field emission cathodes) at room temperature. Efficient cathodes based on diamond are being developed by SI Diamond Technology (SIDT) as components for bright, sunlight-readable, flat panel displays. When the project started, it was known that only a small fraction (<1%) of the cathode area is active in electron emission and that the emission sites themselves are sub-micron in size. The critical challenge of this project was to develop new microcharacterization methods capable of examining known emission sites. The research team used a combination of cathode emission imaging (developed at SIDT), micro-Raman spectroscopy (LBNL), and electron microscopy and spectroscopy (National Center for Electron Microscopy, LBNL) to examine the properties of known emission sites. The most significant accomplishment of the project was the development at LBNL of a very high resolution scanning probe that, for the first time, measured simultaneously the topography and electrical characteristics of single emission sites. The increased understanding of the emission mechanism helped SIDT to develop a new cathode material,''nano-diamond,'' which they have incorporated into their Field Emission Picture Element (FEPix) product. SIDT is developing large-format flat panel displays based on these picture elements that will be brighter and more efficient than existing outdoor displays such as Jumbotrons. The energy saving that will be realized if field emission displays are introduced commercially is in line with the energy conservation mission of DOE. The unique characterization tools developed in this project (particularly the new scanning microscopy method) are being used in ongoing BES-funded basic research.

  19. Luminescent studies of fluorescent chromophore-doped silica aerogels for flat panel display applications

    SciTech Connect (OSTI)

    Glauser, S.A.C. [California Univ., Davis, CA (United States). Dept. of Applied Science; Lee, H.W.H. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The remarkable optical and electronic properties of doped and undoped silica aerogels establish their utility as unique, mulitfunctional host materials for fluorescent dyes and other luminescent materials for display and imaging applications. We present results on the photoluminescence, absorption, and photoluminescence excitation spectra of undoped silica aerogels and aerogels doped with Er{sup 3+}, rhodamine 6G (R6G), and fluorescein. 4 refs., 12 figs.

  20. Thin optical display panel

    DOE Patents [OSTI]

    Veligdan, James Thomas

    1997-01-01

    An optical display includes a plurality of optical waveguides each including a cladding bound core for guiding internal display light between first and second opposite ends by total internal reflection. The waveguides are stacked together to define a collective display thickness. Each of the cores includes a heterogeneous portion defining a light scattering site disposed longitudinally between the first and second ends. Adjacent ones of the sites are longitudinally offset from each other for forming a longitudinal internal image display over the display thickness upon scattering of internal display light thereagainst for generating a display image. In a preferred embodiment, the waveguides and scattering sites are transparent for transmitting therethrough an external image in superposition with the display image formed by scattering the internal light off the scattering sites for defining a heads up display.

  1. Precise Application of Transparent Conductive Oxide Coatings for Flat Panel

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Displays and Photovoltaic Cells - Energy Innovation Portal Solar Photovoltaic Solar Photovoltaic Advanced Materials Advanced Materials Find More Like This Return to Search Precise Application of Transparent Conductive Oxide Coatings for Flat Panel Displays and Photovoltaic Cells Argonne National Laboratory Contact ANL About This Technology <p align="center"> New <em>ALD reaction chamber containing 12-in x 12-in piece of plate glass</em></p> New ALD reaction

  2. Precise Application of Transparent Conductive Oxide Coatings for Flat Panel

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Displays and Photovoltaic Cells | Argonne National Laboratory Precise Application of Transparent Conductive Oxide Coatings for Flat Panel Displays and Photovoltaic Cells Technology available for licensing: New transparent conducting oxide (TCO) coatings are deposited using atomic layer deposition (ALD). Provides uniform coating of complex, 3D nanostructures such as electrodes for next-generation PV cells Improved coating precision uses less material and reduces cost PDF icon

  3. Multi-clad black display panel

    SciTech Connect (OSTI)

    Veligdan, James T.; Biscardi, Cyrus; Brewster, Calvin

    2002-01-01

    A multi-clad black display panel, and a method of making a multi-clad black display panel, are disclosed, wherein a plurality of waveguides, each of which includes a light-transmissive core placed between an opposing pair of transparent cladding layers and a black layer disposed between transparent cladding layers, are stacked together and sawed at an angle to produce a wedge-shaped optical panel having an inlet face and an outlet face.

  4. Light redirective display panel and a method of making a light redirective display panel

    SciTech Connect (OSTI)

    Veligdan, James T.

    2002-01-01

    An optical display panel which provides improved light intensity at a viewing angle by redirecting light emitting from the viewing screen, and a method of making a light redirective display panel, are disclosed. The panel includes an inlet face at one end for receiving light, and an outlet screen at an opposite end for displaying the light. The inlet face is defined at one end of a transparent body, which body may be formed by a plurality of waveguides, and the outlet screen is defined at an opposite end of the body. The screen includes light redirective elements at the outlet screen for re-directing light emitting from the outlet screen. The method includes stacking a plurality of glass sheets, with a layer of adhesive or epoxy between each sheet, curing the adhesive to form a stack, placing the stack against a saw and cutting the stack at two opposite ends to form a wedge-shaped panel having an inlet face and an outlet face, and forming at the outlet face a plurality of light redirective elements which direct light incident on the outlet face into a controlled light cone.

  5. Light Redirective Display Panel And A Method Of Making A Light Redirective Display Panel

    SciTech Connect (OSTI)

    Veligdan, James T.

    2005-07-26

    An optical display panel which provides improved light intensity at a viewing angle by redirecting light emitting from the viewing screen, and a method of making a light redirective display panel, are disclosed. The panel includes an inlet face at one end for receiving light, and an outlet screen at an opposite end for displaying the light. The inlet face is defined at one end of a transparent body, which body may be formed by a plurality of waveguides, and the outlet screen is defined at an opposite end of the body. The screen includes light redirective elements at the outlet screen for re-directing light emitting from the outlet screen. The method includes stacking a plurality of glass sheets, with a layer of adhesive or epoxy between each sheet, curing the adhesive to form a stack, placing the stack against a saw and cutting the stack at two opposite ends to form a wedge-shaped panel having an inlet face and an outlet face, and forming at the outlet face a plurality of light redirective elements which direct light incident on the outlet face into a controlled light cone.

  6. Data Acquisition Scan for Large Area Flat Panel Digital X-ray Detector Array

    Energy Science and Technology Software Center (OSTI)

    2004-05-01

    Interface large area flat panel digital detector and motion control system for computed tomographic data acquisition.

  7. An improved method for flat-field correction of flat panel x-ray detector

    SciTech Connect (OSTI)

    Kwan, Alexander L.C.; Seibert, J. Anthony; Boone, John M.

    2006-02-15

    In this Technical Note, the effects of different flat-field techniques are examined for a cesium iodide flat panel detector, which exhibited a slightly nonlinear exposure response. The results indicate that the variable flat-field correction method with the appropriate polynomial fit provides excellent correction throughout the entire exposure range. The averaged normalized variation factor, used to assess the nonuniformity of the flat-field correction, decreased from 30.76 for the fixed correction method to 4.13 for the variable flat-field correction method with a fourth-order polynomial fit for the 60 kVp spectrum, and from 16.42 to 3.97 for the 95 kVp spectrum.

  8. Calibration of an amorphous-silicon flat panel portal imager for exit-beam dosimetry

    SciTech Connect (OSTI)

    Chen, Josephine; Chuang, Cynthia F.; Morin, Olivier; Aubin, Michele; Pouliot, Jean

    2006-03-15

    Amorphous-silicon flat panel detectors are currently used to acquire digital portal images with excellent image quality for patient alignment before external beam radiation therapy. As a first step towards interpreting portal images acquired during treatment in terms of the actual dose delivered to the patient, a calibration method is developed to convert flat panel portal images to the equivalent water dose deposited in the detector plane and at a depth of 1.5 cm. The method is based on empirical convolution models of dose deposition in the flat panel detector and in water. A series of calibration experiments comparing the response of the flat panel imager and ion chamber measurements of dose in water determines the model parameters. Kernels derived from field size measurements account for the differences in the production and detection of scattered radiation in the two systems. The dissimilar response as a function of beam energy spectrum is characterized from measurements performed at various off-axis positions and for increasing attenuator thickness in the beam. The flat panel pixel inhomogeneity is corrected by comparing a large open field image with profiles measured in water. To verify the accuracy of the calibration method, calibrated flat panel profiles were compared with measured dose profiles for fields delivered through solid water slabs, a solid water phantom containing an air cavity, and an anthropomorphic head phantom. Open rectangular fields of various sizes and locations as well as a multileaf collimator-shaped field were delivered. For all but the smallest field centered about the central axis, the calibrated flat panel profiles matched the measured dose profiles with little or no systematic deviation and approximately 3% (two standard deviations) accuracy for the in-field region. The calibrated flat panel profiles for fields located off the central axis showed a small -1.7% systematic deviation from the measured profiles for the in-field region

  9. Recovery of valuable materials from waste liquid crystal display panel

    SciTech Connect (OSTI)

    Li Jinhui Gao Song; Duan Huabo; Liu Lili

    2009-07-15

    Associated with the rapid development of the information and electronic industry, liquid crystal displays (LCDs) have been increasingly sold as displays. However, during the discarding at their end-of-life stage, significant environmental hazards, impacts on health and a loss of resources may occur, if the scraps are not managed in an appropriate way. In order to improve the efficiency of the recovery of valuable materials from waste LCDs panel in an environmentally sound manner, this study presents a combined recycling technology process on the basis of manual dismantling and chemical treatment of LCDs. Three key processes of this technology have been studied, including the separation of LCD polarizing film by thermal shock method the removal of liquid crystals between the glass substrates by the ultrasonic cleaning, and the recovery of indium metal from glass by dissolution. The results show that valuable materials (e.g. indium) and harmful substances (e.g. liquid crystals) could be efficiently recovered or separated through above-mentioned combined technology. The optimal conditions are: (1) the peak temperature of thermal shock to separate polarizing film, ranges from 230 to 240 deg. C, where pyrolysis could be avoided; (2) the ultrasonic-assisted cleaning was most efficient at a frequency of 40 KHz (P = 40 W) and the exposure of the substrate to industrial detergents for 10 min; and (3) indium separation from glass in a mix of concentrated hydrochloric acid at 38% and nitric acid at 69% (HCl:HNO{sub 3}:H{sub 2}O = 45:5:50, volume ratio). The indium separation process was conducted with an exposure time of 30 min at a constant temperature of 60 deg. C.

  10. Measurement of joint kinematics using a conventional clinical single-perspective flat-panel radiography system

    SciTech Connect (OSTI)

    Seslija, Petar; Teeter, Matthew G.; Yuan Xunhua; Naudie, Douglas D. R.; Bourne, Robert B.; MacDonald, Steven J.; Peters, Terry M.; Holdsworth, David W.

    2012-10-15

    Purpose: The ability to accurately measure joint kinematics is an important tool in studying both normal joint function and pathologies associated with injury and disease. The purpose of this study is to evaluate the efficacy, accuracy, precision, and clinical safety of measuring 3D joint motion using a conventional flat-panel radiography system prior to its application in an in vivo study. Methods: An automated, image-based tracking algorithm was implemented to measure the three-dimensional pose of a sparse object from a two-dimensional radiographic projection. The algorithm was tested to determine its efficiency and failure rate, defined as the number of image frames where automated tracking failed, or required user intervention. The accuracy and precision of measuring three-dimensional motion were assessed using a robotic controlled, tibiofemoral knee phantom programmed to mimic a subject with a total knee replacement performing a stair ascent activity. Accuracy was assessed by comparing the measurements of the single-plane radiographic tracking technique to those of an optical tracking system, and quantified by the measurement discrepancy between the two systems using the Bland-Altman technique. Precision was assessed through a series of repeated measurements of the tibiofemoral kinematics, and was quantified using the across-trial deviations of the repeated kinematic measurements. The safety of the imaging procedure was assessed by measuring the effective dose of ionizing radiation associated with the x-ray exposures, and analyzing its relative risk to a human subject. Results: The automated tracking algorithm displayed a failure rate of 2% and achieved an average computational throughput of 8 image frames/s. Mean differences between the radiographic and optical measurements for translations and rotations were less than 0.08 mm and 0.07 Degree-Sign in-plane, and 0.24 mm and 0.6 Degree-Sign out-of-plane. The repeatability of kinematics measurements performed

  11. Transmission type flat-panel X-ray source using ZnO nanowire field emitters

    SciTech Connect (OSTI)

    Chen, Daokun; Song, Xiaomeng; Zhang, Zhipeng; Chen, Jun; Li, Ziping; She, Juncong; Deng, Shaozhi; Xu, Ningsheng

    2015-12-14

    A transmission type flat-panel X-ray source in diode structure was fabricated. Large-scale patterned ZnO nanowires grown on a glass substrate by thermal oxidation were utilized as field emitters, and tungsten thin film coated on silica glass was used as the transmission anode. Uniform distribution of X-ray generation was achieved, which benefited from the uniform electron emission from ZnO nanowires. Self-ballasting effect induced by the intrinsic resistance of ZnO nanowire and decreasing of screening effect caused by patterned emitters account for the uniform emission. Characteristic X-ray peaks of W-L lines and bremsstrahlung X-rays have been observed under anode voltages at a range of 18–20 kV, the latter of which were the dominant X-ray signals. High-resolution X-ray images with spatial resolution less than 25 μm were obtained by the flat-panel X-ray source. The high resolution was attributed to the small divergence angle of the emitted X-rays from the transmission X-ray source.

  12. Hysterosalpingography using a flat panel unit: Evaluation and optimization of ovarian radiation dose

    SciTech Connect (OSTI)

    Messaris, Gerasimos A. T.; Abatzis, Ilias; Kagadis, George C.; Samartzis, Alexandros P.; Athanasopoulou, Panagiota; Christeas, Nikolaos; Katsanos, Konstantinos; Karnabatidis, Dimitrios; Nikiforidis, George C.

    2012-07-15

    Purpose: The aim of the present study was the evaluation and optimization of radiation dose to the ovaries (D) in hysterosalpingography (HSG). Methods: The study included a phantom study and a clinical one. In the phantom study, we evaluated imaging results for different geometrical setups and irradiation conditions. In the clinical study, 34 women were assigned into three different fluoroscopy modes and D was estimated with direct cervical TLD measurements. Results: In the phantom study, we used a source-to-image-distance (SID) of 110 cm and a field diagonal of 48 cm, and thus decreased air KERMA rate (KR) by 19% and 70%, respectively, for beam filtration: 4 mm Al and 0.9 mm Cu (Low dose). The least radiation exposure was accomplished by using the 3.75 pps fluoroscopy mode in conjunction with beam filtration: Low dose. In the clinical study, D normalized to 50 s of fluoroscopy time with a 3.75 pps fluoroscopy mode reached a value of 0.45 {+-} 0.04 mGy. Observers' evaluation of diagnostic image quality did not significantly differ for the three different modes of acquisition that were compared. Conclusions: Digital spot radiographs could be omitted in modern flat panel systems during HSG. Fluoroscopy image acquisitions in a modern flat panel unit at 3.75 pps and a beam filtration of 4 mm Al and 0.9 mm Cu demonstrate acceptable image quality with an average D equal to 0.45 mGy. This value is lower compared to the studied literature. For these reasons, the proposed method may be recommended for routine HSG examination in order to limit radiation exposure to the ovaries.

  13. The long-term stability of amorphous silicon flat panel imaging devices for dosimetry purposes

    SciTech Connect (OSTI)

    Louwe, R.J.W.; McDermott, L.N.; Sonke, J.-J.; Tielenburg, R.; Wendling, M.; Herk, M.B. van; Mijnheer, B.J.

    2004-11-01

    This study was carried out to determine the stability of the response of amorphous silicon (a-Si)-flat panel imagers for dosimetry applications. Measurements of the imager's response under reference conditions were performed on a regular basis for four detectors of the same manufacturer. We found that the ambient temperature influenced the dark-field, while the gain of the imager signal was unaffected. Therefore, temperature fluctuations were corrected for by applying a 'dynamic' dark-field correction. This correction method also removed the influence of a small, irreversible increase of the dark-field current, which was equal to 0.5% of the dynamic range of the imager per year and was probably caused by mild radiation damage to the a-Si array. By applying a dynamic dark-field correction, excellent stability of the response over the entire panel of all imagers of 0.5% (1 SD) was obtained over an observation period up to 23 months. However, two imagers had to be replaced after several months. For one imager, an image segment stopped functioning, while the image quality of the other imager degraded significantly. We conclude that the tested a-Si EPIDs have a very stable response and are therefore well suited for dosimetry. We recommend, however, applying quality assurance tests dedicated to both imaging and dosimetry.

  14. DuPont Displays Develops Low-Cost Method of Printing OLED Panels

    Office of Energy Efficiency and Renewable Energy (EERE)

    DuPont Displays Inc. (DDI) has developed a novel way of printing color-tunable OLED lighting panels that keeps manufacturing costs low. The method involves processing the organic layers from solution, with most of the process steps taking place under atmospheric conditions rather than in a high vacuum. Industry-standard slot-coating methods are used in conjunction with nozzle printing—in which the solutions of organic materials are continuously jetted through an array of nozzles moving at high speed—allowing the light-emitting materials to be spatially patterned.

  15. A forward bias method for lag correction of an a-Si flat panel detector

    SciTech Connect (OSTI)

    Starman, Jared; Tognina, Carlo; Partain, Larry; Fahrig, Rebecca

    2012-01-15

    Purpose: Digital a-Si flat panel (FP) x-ray detectors can exhibit detector lag, or residual signal, of several percent that can cause ghosting in projection images or severe shading artifacts, known as the radar artifact, in cone-beam computed tomography (CBCT) reconstructions. A major contributor to detector lag is believed to be defect states, or traps, in the a-Si layer of the FP. Software methods to characterize and correct for the detector lag exist, but they may make assumptions such as system linearity and time invariance, which may not be true. The purpose of this work is to investigate a new hardware based method to reduce lag in an a-Si FP and to evaluate its effectiveness at removing shading artifacts in CBCT reconstructions. The feasibility of a novel, partially hardware based solution is also examined. Methods: The proposed hardware solution for lag reduction requires only a minor change to the FP. For pulsed irradiation, the proposed method inserts a new operation step between the readout and data collection stages. During this new stage the photodiode is operated in a forward bias mode, which fills the defect states with charge. A Varian 4030CB panel was modified to allow for operation in the forward bias mode. The contrast of residual lag ghosts was measured for lag frames 2 and 100 after irradiation ceased for standard and forward bias modes. Detector step response, lag, SNR, modulation transfer function (MTF), and detective quantum efficiency (DQE) measurements were made with standard and forward bias firmware. CBCT data of pelvic and head phantoms were also collected. Results: Overall, the 2nd and 100th detector lag frame residual signals were reduced 70%-88% using the new method. SNR, MTF, and DQE measurements show a small decrease in collected signal and a small increase in noise. The forward bias hardware successfully reduced the radar artifact in the CBCT reconstruction of the pelvic and head phantoms by 48%-81%. Conclusions: Overall, the

  16. A two-dimensional multispecies fluid model of the plasma in an ac plasma display panel

    SciTech Connect (OSTI)

    Campbell, R.B.; Veerasingam, R.; McGrath, R.T.

    1995-08-01

    A time dependent, two-dimensional mode for simulating the plasma evolution in an AC plasma display panel (AC-PDP) is described. Reaction-convection (mobility)-diffusion equations for charged particles and excited heavy neutral species are solved along with Poisson`s equation, a radiation transport equation, a surface charge buildup equation, and an external L-R-C circuit equation using a fully implicit numerical method. Electron-driven rate coefficients are computed with a 0-D Boltzmann solver in the local field approximation. For studying the particle dynamics in pure helium, they consider a reduced model in which radiation transport is ignored and the excited species manifold is collapsed to composite metastable and excited states. The model predictions of breakdown voltage are quite sensitive to the value of the secondary electron emission coefficient assumed and the uncertainties in the electron-driven reaction rates. An initial comparison between the model predictions and I-V measurements from a specially constructed helium-filled panel is made with qualitatively similar behavior. The lack of quantitative agreement can be explained by a combination of uncertainties in the model input data and uncertainty in the initial surface charge state in the experiments.

  17. A nonlinear lag correction algorithm for a-Si flat-panel x-ray detectors

    SciTech Connect (OSTI)

    Starman, Jared; Star-Lack, Josh; Virshup, Gary; Shapiro, Edward; Fahrig, Rebecca

    2012-10-15

    Purpose: Detector lag, or residual signal, in a-Si flat-panel (FP) detectors can cause significant shading artifacts in cone-beam computed tomography reconstructions. To date, most correction models have assumed a linear, time-invariant (LTI) model and correct lag by deconvolution with an impulse response function (IRF). However, the lag correction is sensitive to both the exposure intensity and the technique used for determining the IRF. Even when the LTI correction that produces the minimum error is found, residual artifact remains. A new non-LTI method was developed to take into account the IRF measurement technique and exposure dependencies. Methods: First, a multiexponential (N = 4) LTI model was implemented for lag correction. Next, a non-LTI lag correction, known as the nonlinear consistent stored charge (NLCSC) method, was developed based on the LTI multiexponential method. It differs from other nonlinear lag correction algorithms in that it maintains a consistent estimate of the amount of charge stored in the FP and it does not require intimate knowledge of the semiconductor parameters specific to the FP. For the NLCSC method, all coefficients of the IRF are functions of exposure intensity. Another nonlinear lag correction method that only used an intensity weighting of the IRF was also compared. The correction algorithms were applied to step-response projection data and CT acquisitions of a large pelvic phantom and an acrylic head phantom. The authors collected rising and falling edge step-response data on a Varian 4030CB a-Si FP detector operating in dynamic gain mode at 15 fps at nine incident exposures (2.0%-92% of the detector saturation exposure). For projection data, 1st and 50th frame lag were measured before and after correction. For the CT reconstructions, five pairs of ROIs were defined and the maximum and mean signal differences within a pair were calculated for the different exposures and step-response edge techniques. Results: The LTI

  18. The effect of a Si-doped protective layer on the discharge characteristics of an alternating current plasma display panel

    SciTech Connect (OSTI)

    Lee, Don-Kyu; Park, Chung-Hoo; Lee, Hae June; Choi, Joon-Young; Kim, Dong-Hyun; Lee, Ho-Jun

    2007-10-15

    In order to improve the discharge characteristics such as discharge voltage, luminance, luminous efficacy, high-temperature misfiring, and lifetime, a small amount of Si was added to the MgO protective layer of a plasma display panel. The MgO protective layers were deposited by using an electron-beam evaporation method. The addition of Si onto a MgO protective layer can effectively increase the secondary electron emission coefficient so as to improve the discharge characteristics compared with using a pure MgO film. Both the surface characteristics of the protective layer and the electro-optical properties of 4 in. test panels were investigated, such as the discharge voltage, luminance, luminous efficacy, high-temperature misfiring, and lifetime. The results show that Si doping of 0.03%-0.04% in MgO has the best performance on plasma display panels.

  19. Nitrogen incorporated ultrananocrystalline diamond based field emitter array for a flat-panel x-ray source

    SciTech Connect (OSTI)

    Posada, Chrystian M.; Grant, Edwin J.; Lee, Hyoung K.; Castaño, Carlos H.; Divan, Ralu; Sumant, Anirudha V.; Rosenmann, Daniel; Stan, Liliana

    2014-04-07

    A field emission based flat-panel transmission x-ray source is being developed as an alternative for medical and industrial imaging. A field emitter array (FEA) prototype based on nitrogen incorporated ultrananocrystalline diamond film has been fabricated to be used as the electron source of this flat panel x-ray source. The FEA prototype was developed using conventional microfabrication techniques. The field emission characteristics of the FEA prototype were evaluated. Results indicated that emission current densities of the order of 6 mA/cm{sup 2} could be obtained at electric fields as low as 10 V/μm to 20 V/μm. During the prototype microfabrication process, issues such as delamination of the extraction gate and poor etching of the SiO{sub 2} insulating layer located between the emitters and the extraction layer were encountered. Consequently, alternative FEA designs were investigated. Experimental and simulation data from the first FEA prototype were compared and the results were used to evaluate the performance of alternative single and double gate designs that would yield better field emission characteristics compared to the first FEA prototype. The best simulation results are obtained for the double gate FEA design, when the diameter of the collimator gate is around 2.6 times the diameter of the extraction gate.

  20. Reduction of ring artifacts in CBCT: Detection and correction of pixel gain variations in flat panel detectors

    SciTech Connect (OSTI)

    Altunbas, Cem; Lai, Chao-Jen; Zhong, Yuncheng; Shaw, Chris C.

    2014-09-15

    Purpose: In using flat panel detectors (FPD) for cone beam computed tomography (CBCT), pixel gain variations may lead to structured nonuniformities in projections and ring artifacts in CBCT images. Such gain variations can be caused by change in detector entrance exposure levels or beam hardening, and they are not accounted by conventional flat field correction methods. In this work, the authors presented a method to identify isolated pixel clusters that exhibit gain variations and proposed a pixel gain correction (PGC) method to suppress both beam hardening and exposure level dependent gain variations. Methods: To modulate both beam spectrum and entrance exposure, flood field FPD projections were acquired using beam filters with varying thicknesses. “Ideal” pixel values were estimated by performing polynomial fits in both raw and flat field corrected projections. Residuals were calculated by taking the difference between measured and ideal pixel values to identify clustered image and FPD artifacts in flat field corrected and raw images, respectively. To correct clustered image artifacts, the ratio of ideal to measured pixel values in filtered images were utilized as pixel-specific gain correction factors, referred as PGC method, and they were tabulated as a function of pixel value in a look-up table. Results: 0.035% of detector pixels lead to clustered image artifacts in flat field corrected projections, where 80% of these pixels were traced back and linked to artifacts in the FPD. The performance of PGC method was tested in variety of imaging conditions and phantoms. The PGC method reduced clustered image artifacts and fixed pattern noise in projections, and ring artifacts in CBCT images. Conclusions: Clustered projection image artifacts that lead to ring artifacts in CBCT can be better identified with our artifact detection approach. When compared to the conventional flat field correction method, the proposed PGC method enables characterization of nonlinear

  1. Signal and noise transfer properties of CMOS based active pixel flat panel imager coupled to structured CsI:Tl

    SciTech Connect (OSTI)

    Arvanitis, C. D.; Bohndiek, S. E.; Blakesley, J.; Olivo, A.; Speller, R. D.

    2009-01-15

    Complementary metal-oxide-semiconductors (CMOS) active pixel sensors can be optically coupled to CsI:Tl phosphors forming a indirect active pixel flat panel imager (APFPI) for high performance medical imaging. The aim of this work is to determine the x-ray imaging capabilities of CMOS-based APFPI and study the signal and noise transfer properties of CsI:Tl phosphors. Three different CsI:Tl phosphors from two different vendors have been used to produce three system configurations. The performance of each system configuration has been studied in terms of the modulation transfer function (MTF), noise power spectra, and detective quantum efficiency (DQE) in the mammographic energy range. A simple method to determine quantum limited systems in this energy range is also presented. In addition, with aid of monochromatic synchrotron radiation, the effect of iodine characteristic x-rays of the CsI:Tl on the MTF has been determined. A Monte Carlo simulation of the signal transfer properties of the imager is also presented in order to study the stages that degrade the spatial resolution of our current system. The effect of using substrate patterning during the growth of CsI:Tl columnar structure was also studied, along with the effect of CsI:Tl fixed pattern noise due to local variations in the scintillation light. CsI:Tl fixed pattern noise appears to limit the performance of our current system configurations. All the system configurations are quantum limited at 0.23 {mu}C/kg with two of them having DQE (0) equal to 0.57. Active pixel flat panel imagers are shown to be digital x-ray imagers with almost constant DQE throughout a significant part of their dynamic range and in particular at very low exposures.

  2. Empirical binary tomography calibration (EBTC) for the precorrection of beam hardening and scatter for flat panel CT

    SciTech Connect (OSTI)

    Grimmer, Rainer; Kachelriess, Marc

    2011-04-15

    Purpose: Scatter and beam hardening are prominent artifacts in x-ray CT. Currently, there is no precorrection method that inherently accounts for tube voltage modulation and shaped prefiltration. Methods: A method for self-calibration based on binary tomography of homogeneous objects, which was proposed by B. Li et al. [''A novel beam hardening correction method for computed tomography,'' in Proceedings of the IEEE/ICME International Conference on Complex Medical Engineering CME 2007, pp. 891-895, 23-27 May 2007], has been generalized in order to use this information to preprocess scans of other, nonbinary objects, e.g., to reduce artifacts in medical CT applications. Further on, the method was extended to handle scatter besides beam hardening and to allow for detector pixel-specific and ray-specific precorrections. This implies that the empirical binary tomography calibration (EBTC) technique is sensitive to spectral effects as they are induced by the heel effect, by shaped prefiltration, or by scanners with tube voltage modulation. The presented method models the beam hardening correction by using a rational function, while the scatter component is modeled using the pep model of B. Ohnesorge et al. [''Efficient object scatter correction algorithm for third and fourth generation CT scanners,'' Eur. Radiol. 9(3), 563-569 (1999)]. A smoothness constraint is applied to the parameter space to regularize the underdetermined system of nonlinear equations. The parameters determined are then used to precorrect CT scans. Results: EBTC was evaluated using simulated data of a flat panel cone-beam CT scanner with tube voltage modulation and bow-tie prefiltration and using real data of a flat panel cone-beam CT scanner. In simulation studies, where the ground truth is known, the authors' correction model proved to be highly accurate and was able to reduce beam hardening by 97% and scatter by about 75%. Reconstructions of measured data showed significantly less artifacts than

  3. Noise, sampling, and the number of projections in cone-beam CT with a flat-panel detector

    SciTech Connect (OSTI)

    Zhao, Z.; Gang, G. J.; Siewerdsen, J. H.

    2014-06-15

    Purpose: To investigate the effect of the number of projection views on image noise in cone-beam CT (CBCT) with a flat-panel detector. Methods: This fairly fundamental consideration in CBCT system design and operation was addressed experimentally (using a phantom presenting a uniform medium as well as statistically motivated “clutter”) and theoretically (using a cascaded systems model describing CBCT noise) to elucidate the contributing factors of quantum noise (σ{sub Q}), electronic noise (σ{sub E}), and view aliasing (σ{sub view}). Analysis included investigation of the noise, noise-power spectrum, and modulation transfer function as a function of the number of projections (N{sub proj}), dose (D{sub tot}), and voxel size (b{sub vox}). Results: The results reveal a nonmonotonic relationship between image noise andN{sub proj} at fixed total dose: for the CBCT system considered, noise decreased with increasing N{sub proj} due to reduction of view sampling effects in the regime N{sub proj} <∼200, above which noise increased with N{sub proj} due to increased electronic noise. View sampling effects were shown to depend on the heterogeneity of the object in a direct analytical relationship to power-law anatomical clutter of the form κ/f {sup β}—and a general model of individual noise components (σ{sub Q}, σ{sub E}, and σ{sub view}) demonstrated agreement with measurements over a broad range in N{sub proj}, D{sub tot}, and b{sub vox}. Conclusions: The work elucidates fairly basic elements of CBCT noise in a manner that demonstrates the role of distinct noise components (viz., quantum, electronic, and view sampling noise). For configurations fairly typical of CBCT with a flat-panel detector (FPD), the analysis reveals a “sweet spot” (i.e., minimum noise) in the rangeN{sub proj} ∼ 250–350, nearly an order of magnitude lower in N{sub proj} than typical of multidetector CT, owing to the relatively high electronic noise in FPDs. The analysis

  4. Peer review panel summary report for technical determination of mixed waste incineration off-gas systems for Rocky Flats; Appendix A

    SciTech Connect (OSTI)

    1992-12-31

    A Peer Review Panel was convened on September 15-17, 1992 in Boulder, Co. The members of this panel included representatives from DOE, EPA, and DOE contractors along with invited experts in the fields of air pollution control and waste incineration. The primary purpose of this review panel was to make a technical determination of a hold, test and release off gas capture system should be implemented in the proposed RF Pland mixed waste incineration system; or if a state of the art continuous air pollution control and monitoring system should be utilized as the sole off-gas control system. All of the evaluations by the panel were based upon the use of the fluidized bed unit proposed by Rocky Flats and cannot be generalized to other systems.

  5. Gain and offset calibration reduces variation in exposure-dependent SNR among systems with identical digital flat-panel detectors

    SciTech Connect (OSTI)

    Willis, Charles E.; Vinogradskiy, Yevgeniy Y.; Lofton, Brad K.; White, R. Allen

    2011-07-15

    Purpose: The conditions under which vendor performance criteria for digital radiography systems are obtained do not adequately simulate the conditions of actual clinical imaging with respect to radiographic technique factors, scatter production, and scatter control. Therefore, the relationship between performance under ideal conditions and performance in clinical practice remains unclear. Using data from a large complement of systems in clinical use, the authors sought to develop a method to establish expected performance criteria for digital flat-panel radiography systems with respect to signal-to-noise ratio (SNR) versus detector exposure under clinical conditions for thoracic imaging. Methods: The authors made radiographic exposures of a patient-equivalent chest phantom at 125 kVp and 180 cm source-to-image distance. The mAs value was modified to produce exposures above and below the mAs delivered by automatic exposure control. Exposures measured free-in-air were corrected to the imaging plane by the inverse square law, by the attenuation factor of the phantom, and by the Bucky factor of the grid for the phantom, geometry, and kilovolt peak. SNR was evaluated as the ratio of the mean to the standard deviation (SD) of a region of interest automatically selected in the center of each unprocessed image. Data were acquired from 18 systems, 14 of which were tested both before and after gain and offset calibration. SNR as a function of detector exposure was interpolated using a double logarithmic function to stratify the data into groups of 0.2, 0.5, 1.0, 2.0, and 5.0 mR exposure (1.8, 4.5, 9.0, 18, and 45 {mu}Gy air KERMA) to the detector. Results: The mean SNR at each exposure interval after calibration exhibited linear dependence on the mean SNR before calibration (r{sup 2} = 0.9999). The dependence was greater than unity (m = 1.101 {+-} 0.006), and the difference from unity was statistically significant (p < 0.005). The SD of mean SNR after calibration also

  6. SU-D-12A-04: Investigation of a 2D Antiscatter Grid for Flat Panel Detectors

    SciTech Connect (OSTI)

    Altunbas, C; Kavanagh, B; Miften, M; Zhong, Y; Shaw, C

    2014-06-01

    Purpose: To improve CT number accuracy and contrast sensitivity, a novel 2D antiscatter grid (ASG) for flat panel detector (FPD) based CBCT imaging was evaluated. Experiments were performed to characterize the scatter rejection and contrast sensitivity performance of ASG. The reduction in primary transmission for various ASG geometries was also evaluated by a computational model. Methods: The 2D ASG design was based on multi-hole collimators used in Nuclear Medicine. It consisted of abutted hexagon shaped apertures with 2.5 mm pitch and 32 mm height, and separated by 0.25 mm thick lead septa. Scatter-to-primary ratio (SPR), contrast-to-noise ratio (CNR), and mean primary transmission were measured using a benchtop FPD/x-ray source system. Acrylic slabs of varying thicknesses were imaged with a contrast-detail phantom to measure CNR and SPR under different scatter conditions. Primary transmission was also measured by averaging pixel values in flood field images without the phantom. We additionally explored variation of primary transmission with pitch and septum thickness using a computational model of our ASG. Results: Our 2D ASG reduced the SPR from 3.3 to 0.12, and improved CNR by 50% in 20 cm thick slab phantom projections acquired at 120 kVp. While the measured primary transmission was 72.8%, our simulations show that primary transmission can be increased to 86% by reducing the septum thickness to 0.1 mm. Primary transmission further increases to 93% if septum thickness of 0.1 mm is used in conjunction with an increased pitch of 4 mm. Conclusion: The 2D ASG appears to be a promising scatter rejection device, offering both superior scatter rejection and improved contrast sensitivity. Though its lead footprint reduced primary transmission, our work shows that optimization of aperture pitch and septum thickness can significantly improve the primary transmission.

  7. SU-E-I-49: Simulation Study for Removing Scatter Radiation in Cesium-Iodine Based Flat Panel Detector System

    SciTech Connect (OSTI)

    Yoon, Y; Park, M; Kim, H; Kim, K; Kim, J; Morishita, J

    2015-06-15

    Purpose: This study aims to identify the feasibility of a novel cesium-iodine (CsI)-based flat-panel detector (FPD) for removing scatter radiation in diagnostic radiology. Methods: The indirect FPD comprises three layers: a substrate, scintillation, and thin-film-transistor (TFT) layer. The TFT layer has a matrix structure with pixels. There are ineffective dimensions on the TFT layer, such as the voltage and data lines; therefore, we devised a new FPD system having net-like lead in the substrate layer, matching the ineffective area, to block the scatter radiation so that only primary X-rays could reach the effective dimension.To evaluate the performance of this new FPD system, we conducted a Monte Carlo simulation using MCNPX 2.6.0 software. Scatter fractions (SFs) were acquired using no grid, a parallel grid (8:1 grid ratio), and the new system, and the performances were compared.Two systems having different thicknesses of lead in the substrate layer—10 and 20μm—were simulated. Additionally, we examined the effects of different pixel sizes (153×153 and 163×163μm) on the image quality, while keeping the effective area of pixels constant (143×143μm). Results: In case of 10μm lead, the SFs of the new system (∼11%) were lower than those of the other system (∼27% with no grid, ∼16% with parallel grid) at 40kV. However, as the tube voltage increased, the SF of new system (∼19%) was higher than that of parallel grid (∼18%) at 120kV. In the case of 20μm lead, the SFs of the new system were lower than those of the other systems at all ranges of the tube voltage (40–120kV). Conclusion: The novel CsI-based FPD system for removing scatter radiation is feasible for improving the image contrast but must be optimized with respect to the lead thickness, considering the system’s purposes and the ranges of the tube voltage in diagnostic radiology. This study was supported by a grant(K1422651) from Institute of Health Science, Korea University.

  8. Analysis of transient electron energy in a micro dielectric barrier discharge for a high performance plasma display panel

    SciTech Connect (OSTI)

    Uchida, Giichiro; Kajiyama, Hiroshi; Shinoda, Tsutae; Uchida, Satoshi

    2010-01-15

    We present here analysis of electron energy of a micro dielectric barrier discharge (micro-DBD) for alternating-current plasma display panel (ac-PDP) with Ne/Xe gas mixture by using the optical emission spectroscopy (OES). The OES method is quite useful to evaluate a variety of electron energy in a high pressure DBD ignited in a PDP small cell. Experiment shows that the ratio of Ne emission intensity (I{sub Ne}) relative to Xe emission intensity (I{sub Xe}) drastically decreases with time. This temporal profile is well consistent with dynamic behavior of electron temperature in a micro-DBD, calculated in one-dimensional fluid model. I{sub Ne}/I{sub Xe} also decreases with an increase in Xe gas pressure and a decrease in applied voltage especially in the initial stage of discharge, and these reflect the basic features of electron temperature in a micro-DBD. The influences of plasma parameters such as electron temperature on luminous efficacy are also theoretically analyzed using one-dimensional fluid model. The low electron temperature, which is attained at high Xe gas pressure, realizes the efficient Xe excitation for vacuum ultraviolet radiation. The high Xe-pressure condition also induces the rapid growth of discharge and consequent high plasma density, resulting in high electron heating efficiency.

  9. Impact of flat panel-imager veiling glare on scatter-estimation accuracy and image quality of a commercial on-board cone-beam CT imaging system

    SciTech Connect (OSTI)

    Lazos, Dimitrios; Williamson, Jeffrey F.

    2012-09-15

    Purpose: The purposes of this study is to measure the low frequency drop (LFD) of the modulation transfer function (MTF), associated with the long tails of the detector point spread function (PSF) of an on-board flat panel imager and study its impact on cone-beam CT (CBCT) image quality and scatter measurement accuracy. Methods: Two different experimental methods were used to characterize LFD and its associated PSF of a Varian OBI flat-panel detector system: the edge response function (ERF) method and the disk transfer function (DTF) method. PSF was estimated by fitting parametric models to these measurements for four values of the applied voltage (kVp). The resultant PSF was used to demonstrate the effect of LFD on image contrast and CT number accuracy in CBCT images reconstructed from synthetic datasets, as well as, accuracy of scatter measurements with the beam-stop method. Results: The MTFs derived from the measured ERF data revealed LFDs varying from 8% (at 60 kVp) to 10.5% (at 120 kVp), while the intensity of the long PSF tails was found to increase with increasing kVp. The veiling glare line spread functions derived from the ERF and DTF methods were in excellent agreement. Uncorrected veiling glare reduced contrast and the image intensity in CBCT reconstruction, near the phantom periphery (by 67 Hounsfield units in a 20 cm-in-diameter water phantom) and (to a smaller degree) near inhomogeneities. Use of the bow-tie filter mitigated these effects. Veiling glare also resulted in about 10%-15% overestimation of the scatter-to-primary ratio when measured with the beam-stop or beam-stop array method. Conclusions: The long tails of the detector PSF were found to have a modest dependence of beam spectrum, which is reflected on the MTF curve LFD. Our findings show that uncorrected veiling glare can affect quantitative accuracy and contrast in CBCT imaging, based on flat panel imager. In addition, it results in overestimation of the scatter-to-primary ratio, measured

  10. Cone beam breast CT with a high pitch (75 μm), thick (500 μm) scintillator CMOS flat panel detector: Visibility of simulated microcalcifications

    SciTech Connect (OSTI)

    Shen, Youtao; Zhong, Yuncheng; Lai, Chao-Jen; Wang, Tianpeng; Shaw, Chris C.

    2013-10-15

    Purpose: To measure and investigate the improvement of microcalcification (MC) visibility in cone beam breast CT with a high pitch (75 μm), thick (500 μm) scintillator CMOS/CsI flat panel detector (Dexela 2923, Perkin Elmer).Methods: Aluminum wires and calcium carbonate grains of various sizes were embedded in a paraffin cylinder to simulate imaging of calcifications in a breast. Phantoms were imaged with a benchtop experimental cone beam CT system at various exposure levels. In addition to the Dexela detector, a high pitch (50 μm), thin (150 μm) scintillator CMOS/CsI flat panel detector (C7921CA-09, Hamamatsu Corporation, Hamamatsu City, Japan) and a widely used low pitch (194 μm), thick (600 μm) scintillator aSi/CsI flat panel detector (PaxScan 4030CB, Varian Medical Systems) were also used in scanning for comparison. The images were independently reviewed by six readers (imaging physicists). The MC visibility was quantified as the fraction of visible MCs and measured as a function of the estimated mean glandular dose (MGD) level for various MC sizes and detectors. The modulation transfer functions (MTFs) and detective quantum efficiencies (DQEs) were also measured and compared for the three detectors used.Results: The authors have demonstrated that the use of a high pitch (75 μm) CMOS detector coupled with a thick (500 μm) CsI scintillator helped make the smaller 150–160, 160–180, and 180–200 μm MC groups more visible at MGDs up to 10.8, 9, and 10.8 mGy, respectively. It also made the larger 200–212 and 212–224 μm MC groups more visible at MGDs up to 7.2 mGy. No performance improvement was observed for 224–250 μm or larger size groups. With the higher spatial resolution of the Dexela detector based system, the apparent dimensions and shapes of MCs were more accurately rendered. The results show that with the aforementioned detector, a 73% visibility could be achieved in imaging 160–180 μm MCs as compared to 28% visibility achieved by

  11. Detection of Cement Leakage After Vertebroplasty with a Non-Flat-Panel Angio Unit Compared to Multidetector Computed Tomography - An Ex Vivo Study

    SciTech Connect (OSTI)

    Baumann, Clemens Fuchs, Heiko; Westphalen, Kerstin; Hierholzer, Johannes

    2008-11-15

    The purpose of this study was to investigate the detection of cement leakages after vertebroplasty using angiographic computed tomography (ACT) in a non-flat-panel angio unit compared to multidetector computed tomography (MDCT). Vertebroplasty was performed in 19 of 33 cadaver vertebrae (23 thoracic and 10 lumbar segments). In the angio suite, ACT (190{sup o}; 1.5{sup o} per image) was performed to obtain volumetric data. Another volumetric data set of the specimen was obtained by MDCT using a standard algorithm. Nine multiplanar reconstructions in standardized axial, coronal, and sagittal planes of every vertebra were generated from both data sets. Images were evaluated on the basis of a nominal scale with 18 criteria, comprising osseous properties (e.g., integrity of the end plate) and cement distribution (e.g., presence of intraspinal cement). MDCT images were regarded as gold standard and analyzed by two readers in a consensus mode. Rotational acquisitions were analyzed by six blinded readers. Results were correlated with the gold standard using Cohen's {kappa}-coefficient analysis. Furthermore, interobserver variability was calculated. Correlation with the gold standard ranged from no correlation (osseous margins of the neuroforamen, {kappa} = 0.008) to intermediate (trace of vertebroplasty canula; {kappa} = 0.615) for criteria referring to osseous morphology. However, there was an excellent correlation for those criteria referring to cement distribution, with {kappa} values ranging from 0.948 (paravertebral cement distribution) to 0.972 (intraspinal cement distribution). With a minimum of {kappa} = 0.768 ('good correlation') and a maximum of {kappa} = 0.91 ('excellent'), interobserver variability was low. In conclusion, ACT in an angio suite without a flat-panel detector depicts a cement leakage after vertebroplasty as well as MDCT. However, the method does not provide sufficient depiction of osseous morphology.

  12. Uterine Artery Embolization for Leiomyomata: Optimization of the Radiation Dose to the Patient Using a Flat-Panel Detector Angiographic Suite

    SciTech Connect (OSTI)

    Sapoval, Marc Pellerin, Olivier; Rehel, Jean-Luc; Houdoux, Nicolas; Rahmoune, Ghizlaine; Aubert, Bernard; Fitton, Isabelle

    2010-10-15

    The purpose of this study was to assess the ability of low-dose/low-frame fluoroscopy/angiography with a flat-panel detector angiographic suite to reduce the dose delivered to patients during uterine fibroid embolization (UFE). A two-step prospective dosimetric study was conducted, with a flat-panel detector angiography suite (Siemens Axiom Artis) integrating automatic exposure control (AEC), during 20 consecutive UFEs. Patient dosimetry was performed using calibrated thermoluminescent dosimeters placed on the lower posterior pelvis skin. The first step (10 patients; group A) consisted in UFE (bilateral embolization, calibrated microspheres) performed using the following parameters: standard fluoroscopy (15 pulses/s) and angiography (3 frames/s). The second step (next consecutive 10 patients; group B) used low-dose/low-frame fluoroscopy (7.5 pulses/s for catheterization and 3 pulses/s for embolization) and angiography (1 frame/s). We also recorded the total dose-area product (DAP) delivered to the patient and the fluoroscopy time as reported by the manufacturer's dosimetry report. The mean peak skin dose decreased from 2.4 {+-} 1.3 to 0.4 {+-} 0.3 Gy (P = 0.001) for groups A and B, respectively. The DAP values decreased from 43,113 {+-} 27,207 {mu}Gy m{sup 2} for group A to 9,515 {+-} 4,520 {mu}Gy m{sup 2} for group B (P = 0.003). The dose to ovaries and uterus decreased from 378 {+-} 238 mGy (group A) to 83 {+-} 41 mGy (group B) and from 388 {+-} 246 mGy (group A) to 85 {+-} 39 mGy (group B), respectively. Effective doses decreased from 112 {+-} 71 mSv (group A) to 24 {+-} 12 mSv (group B) (P = 0.003). In conclusion, the use of low-dose/low-frame fluoroscopy/angiography, based on a good understanding of the AEC system and also on the technique during uterine fibroid embolization, allows a significant decrease in the dose exposure to the patient.

  13. SU-E-I-07: Response Characteristics and Signal Conversion Modeling of KV Flat-Panel Detector in Cone Beam CT System

    SciTech Connect (OSTI)

    Wang, Yu; Cao, Ruifen; Pei, Xi; Wang, Hui; Hu, Liqin

    2015-06-15

    Purpose: The flat-panel detector response characteristics are investigated to optimize the scanning parameter considering the image quality and less radiation dose. The signal conversion model is also established to predict the tumor shape and physical thickness changes. Methods: With the ELEKTA XVI system, the planar images of 10cm water phantom were obtained under different image acquisition conditions, including tube voltage, electric current, exposure time and frames. The averaged responses of square area in center were analyzed using Origin8.0. The response characteristics for each scanning parameter were depicted by different fitting types. The transmission measured for 10cm water was compared to Monte Carlo simulation. Using the quadratic calibration method, a series of variable-thickness water phantoms images were acquired to derive the signal conversion model. A 20cm wedge water phantom with 2cm step thickness was used to verify the model. At last, the stability and reproducibility of the model were explored during a four week period. Results: The gray values of image center all decreased with the increase of different image acquisition parameter presets. The fitting types adopted were linear fitting, quadratic polynomial fitting, Gauss fitting and logarithmic fitting with the fitting R-Square 0.992, 0.995, 0.997 and 0.996 respectively. For 10cm water phantom, the transmission measured showed better uniformity than Monte Carlo simulation. The wedge phantom experiment show that the radiological thickness changes prediction error was in the range of (-4mm, 5mm). The signal conversion model remained consistent over a period of four weeks. Conclusion: The flat-panel response decrease with the increase of different scanning parameters. The preferred scanning parameter combination was 100kV, 10mA, 10ms, 15frames. It is suggested that the signal conversion model could effectively be used for tumor shape change and radiological thickness prediction. Supported by

  14. SU-C-16A-01: In Vivo Source Position Verification in High Dose Rate (HDR) Prostate Brachytherapy Using a Flat Panel Imager: Initial Clinical Experience

    SciTech Connect (OSTI)

    Franich, R; Smith, R; Millar, J; Haworth, A; Taylor, M; McDermott, L

    2014-06-15

    Purpose: We report our initial clinical experience with a novel position-sensitive source-tracking system based on a flat panel imager. The system has been trialled with 4 prostate HDR brachytherapy patients (8 treatment fractions) in this initial study. Methods: The flat panel imaging system was mounted under a customised carbon fibre couch top assembly (Figure 1). Three gold fiducial markers were implanted into the prostate of each patient at the time of catheter placement. X-ray dwell position markers were inserted into three catheters and a radiograph acquired to locate the implant relative to the imaging device. During treatment, as the HDR source dwells were delivered, images were acquired and processed to determine the position of the source in the patient. Source positions measured by the imaging device were compared to the treatment plan for verification of treatment delivery. Results: Measured dwell positions provided verification of relative dwell spacing within and between catheters, in the coronal plane. Measurements were typically within 2.0mm (0.2mm – 3.3mm, s.d. 0.8mm) of the planned positions over 60 dwells (Figure 2). Discrimination between larger dwell intervals and catheter differentiation were clear. This confirms important delivery attributes such as correct transfer tube connection, source step size, relative catheter positions and therefore overall correct plan selection and delivery. The fiducial markers, visible on the radiograph, provided verification of treatment delivery to the correct anatomical location. The absolute position of the dwells was determined by comparing the measured dwell positions with the x-ray markers from the radiograph, validating the programmed treatment indexer length. The total impact on procedure time was less than 5 minutes. Conclusion: The novel, noninvasive HDR brachytherapy treatment verification system was used clinically with minor impact on workflow. The system allows verification of correct treatment

  15. Micro-valve pump light valve display

    DOE Patents [OSTI]

    Yeechun Lee.

    1993-01-19

    A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

  16. Micro-valve pump light valve display

    DOE Patents [OSTI]

    Lee, Yee-Chun

    1993-01-01

    A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

  17. Noise variance analysis using a flat panel x-ray detector: A method for additive noise assessment with application to breast CT applications

    SciTech Connect (OSTI)

    Yang Kai; Huang, Shih-Ying; Packard, Nathan J.; Boone, John M.

    2010-07-15

    Purpose: A simplified linear model approach was proposed to accurately model the response of a flat panel detector used for breast CT (bCT). Methods: Individual detector pixel mean and variance were measured from bCT projection images acquired both in air and with a polyethylene cylinder, with the detector operating in both fixed low gain and dynamic gain mode. Once the coefficients of the linear model are determined, the fractional additive noise can be used as a quantitative metric to evaluate the system's efficiency in utilizing x-ray photons, including the performance of different gain modes of the detector. Results: Fractional additive noise increases as the object thickness increases or as the radiation dose to the detector decreases. For bCT scan techniques on the UC Davis prototype scanner (80 kVp, 500 views total, 30 frames/s), in the low gain mode, additive noise contributes 21% of the total pixel noise variance for a 10 cm object and 44% for a 17 cm object. With the dynamic gain mode, additive noise only represents approximately 2.6% of the total pixel noise variance for a 10 cm object and 7.3% for a 17 cm object. Conclusions: The existence of the signal-independent additive noise is the primary cause for a quadratic relationship between bCT noise variance and the inverse of radiation dose at the detector. With the knowledge of the additive noise contribution to experimentally acquired images, system modifications can be made to reduce the impact of additive noise and improve the quantum noise efficiency of the bCT system.

  18. TU-F-18C-02: Increasing Amorphous Selenium Thickness in Direct Conversion Flat-Panel Imagers for Contrast-Enhanced Dual-Energy Breast Imaging

    SciTech Connect (OSTI)

    Scaduto, DA; Hu, Y-H; Zhao, W

    2014-06-15

    Purpose: Contrast-enhanced (CE) breast imaging using iodinated contrast agents requires imaging with x-ray spectra at energies greater than those used in mammography. Optimizing amorphous selenium (a-Se) flat panel imagers (FPI) for this higher energy range may increase lesion conspicuity. Methods: We compare imaging performance of a conventional FPI with 200 μm a-Se conversion layer to a prototype FPI with 300 μm a-Se layer. Both detectors are evaluated in a Siemens MAMMOMAT Inspiration prototype digital breast tomosynthesis (DBT) system using low-energy (W/Rh 28 kVp) and high-energy (W/Cu 49 kVp) x-ray spectra. Detectability of iodinated lesions in dual-energy images is evaluated using an iodine contrast phantom. Effects of beam obliquity are investigated in projection and reconstructed images using different reconstruction methods. The ideal observer signal-to-noise ratio is used as a figure-of-merit to predict the optimal a-Se thickness for CE lesion detectability without compromising conventional full-field digital mammography (FFDM) and DBT performance. Results: Increasing a-Se thickness from 200 μm to 300 μm preserves imaging performance at typical mammographic energies (e.g. W/Rh 28 kVp), and improves the detective quantum efficiency (DQE) for high energy (W/Cu 49 kVp) by 30%. While the more penetrating high-energy x-ray photons increase geometric blur due to beam obliquity in the FPI with thicker a-Se layer, the effect on lesion detectability in FBP reconstructions is negligible due to the reconstruction filters employed. Ideal observer SNR for CE objects shows improvements in in-plane detectability with increasing a-Se thicknesses, though small lesion detectability begins to degrade in oblique projections for a-Se thickness above 500 μm. Conclusion: Increasing a-Se thickness in direct conversion FPI from 200 μm to 300 μm improves lesion detectability in CE breast imaging with virtually no cost to conventional FFDM and DBT. This work was partially

  19. SU-E-I-11: Cascaded Linear System Model for Columnar CsI Flat Panel Imagers with Depth Dependent Gain and Blur

    SciTech Connect (OSTI)

    Peng, B; Lubinsky, A; Zheng, H; Zhao, W; Teymurazyan, A

    2014-06-01

    Purpose: To implement a depth dependent gain and blur cascaded linear system model (CLSM) for optimizing columnar structured CsI indirect conversion flat panel imager (FPI) for advanced imaging applications. Methods: For experimental validation, depth dependent escape efficiency, e(z), was extracted from PHS measurement of different CsI scintillators (thickness, substrate and light output). The inherent MTF and DQE of CsI was measured using high resolution CMOS sensor. For CLSM, e(z) and the depth dependent MTF(f,z), were estimated using Monte Carlo simulation (Geant4) of optical photon transport through columnar CsI. Previous work showed that Monte Carlo simulation for CsI was hindered by the non-ideality of its columnar structure. In the present work we allowed variation in columnar width with depth, and assumed diffusive reflective backing and columns. Monte Carlo simulation was performed using an optical point source placed at different depth of the CsI layer, from which MTF(z,f) and e(z) were computed. The resulting e(z) with excellent matching with experimental measurements were then applied to the CLSM, Monte Carlo simulation was repeated until the modeled MTF, DQE(f) also match experimental measurement. Results: For a 150 micron FOS HL type CsI, e(z) varies between 0.56 to 0.45, and the MTF at 14 cycles/mm varies between 62.1% to 3.9%, from the front to the back of the scintillator. The overall MTF and DQE(f) at all frequencies are in excellent agreement with experimental measurements at all frequencies. Conclusion: We have developed a CLSM for columnar CsI scintillators with depth dependent gain and MTF, which were estimated from Monte Carlo simulation with novel optical simulation settings. Preliminary results showed excellent agreement between simulation results and experimental measurements. Future work is aimed at extending this approach to optimize CsI screen optic design and sensor structure for achieving higher DQE(f) in cone-beam CT, which uses

  20. The x-ray time of flight method for investigation of ghosting in amorphous selenium-based flat panel medical x-ray imagers

    SciTech Connect (OSTI)

    Rau, A.W.; Bakueva, L.; Rowlands, J.A.

    2005-10-15

    Amorphous selenium (a-Se) based real-time flat-panel imagers (FPIs) are finding their way into the digital radiology department because they offer the practical advantages of digital x-ray imaging combined with an image quality that equals or outperforms that of conventional systems. The temporal imaging characteristics of FPIs can be affected by ghosting (i.e., radiation-induced changes of sensitivity) when the dose to the detector is high (e.g., portal imaging and mammography) or the images are acquired at a high frame rate (e.g., fluoroscopy). In this paper, the x-ray time-of-flight (TOF) method is introduced as a tool for the investigation of ghosting in a-Se photoconductor layers. The method consists of irradiating layers of a-Se with short x-ray pulses. From the current generated in the a-Se layer, ghosting is quantified and the ghosting parameters (charge carrier generation rate and carrier lifetimes and mobilities) are assessed. The x-ray TOF method is novel in that (1) x-ray sensitivity (S) and ghosting parameters can be measured simultaneously (2) the transport of both holes and electrons can be isolated, and (3) the method is applicable to the practical a-Se layer structure with blocking contacts used in FPIs. The x-ray TOF method was applied to an analysis of ghosting in a-Se photoconductor layers under portal imaging conditions, i.e., 1 mm thick a-Se layers, biased at 5 V/{mu}m, were irradiated using a 6 MV LINAC x-ray beam to a total dose (ghosting dose) of 30 Gy. The initial sensitivity (S{sub 0}) of the a-Se layers was 63{+-}2 nC cm{sup -2} cGy{sup -1}. It was found that S decreases to 30% of S{sub 0} after a ghosting dose of 5 Gy and to 21% after 30 Gy at which point no further change in S occurs. At an x-ray intensity of 22 Gy/s (instantaneous dose rate during a LINAC x-ray pulse), the charge carrier generation rate was 1.25{+-}0.1x10{sup 22} ehp m{sup -3} s{sup -1} and, to a first approximation, independent of the ghosting dose. However, both

  1. Split image optical display

    DOE Patents [OSTI]

    Veligdan, James T.

    2005-05-31

    A video image is displayed from an optical panel by splitting the image into a plurality of image components, and then projecting the image components through corresponding portions of the panel to collectively form the image. Depth of the display is correspondingly reduced.

  2. Split image optical display

    DOE Patents [OSTI]

    Veligdan, James T.

    2007-05-29

    A video image is displayed from an optical panel by splitting the image into a plurality of image components, and then projecting the image components through corresponding portions of the panel to collectively form the image. Depth of the display is correspondingly reduced.

  3. Lowering of the firing voltage and reducing of the discharge delay time in alternating current plasma display panels by a discontinuous spin-coated LaB{sub 6} film on the MgO protective layer

    SciTech Connect (OSTI)

    Deng, Jiang; Zeng, Baoqing; Zhongshan Institute, University of Electronic Science and Technology of China, 528402 zhongshan ; Wang, Xiaoju; Lin, Zulun; Qi, Kangcheng; Cao, Guichuan

    2014-03-15

    A spin coated LaB{sub 6} discontinuous film is covered on MgO protective layer to improve the discharge performance of alternating current plasma display panels. Under the premise of high transmittance of more than 90%, a very small amount of polycrystal LaB{sub 6} powders added in an organic solvent are chosen as the coating solution. The discharge characteristics results show that with 250 torr 5% Xe-Ne pressure, the firing voltage and discharge delay time of the test panel with LaB{sub 6}/MgO double protective layer are decreased by 13.4% and 36.5%, respectively, compared with that of conventional MgO protective layer, likely owing to the low work function of LaB{sub 6.} Furthermore, the aging time of the proposed structure is comparable to that of pure MgO protective layer. Therefore, it will not increase the production costs and is highly suitable to be applied for alternating current plasma display panels with low electrical power consumption.

  4. Integrated display scanner

    DOE Patents [OSTI]

    Veligdan, James T.

    2004-12-21

    A display scanner includes an optical panel having a plurality of stacked optical waveguides. The waveguides define an inlet face at one end and a screen at an opposite end, with each waveguide having a core laminated between cladding. A projector projects a scan beam of light into the panel inlet face for transmission from the screen as a scan line to scan a barcode. A light sensor at the inlet face detects a return beam reflected from the barcode into the screen. A decoder decodes the return beam detected by the sensor for reading the barcode. In an exemplary embodiment, the optical panel also displays a visual image thereon.

  5. Low Voltage, Low Power Organic Light Emitting Transistors for AMOLED Displays

    SciTech Connect (OSTI)

    McCarthy, M. A. [University of Florida, Gainesville; Liu, B. [University of Florida, Gainesville; Donoghue, E. P. [University of Florida, Gainesville; Kravchenko, Ivan I [ORNL; Kim, D. Y. [University of Florida, Gainesville; Reynolds, J. R. [University of Florida, Gainesville; So, Franky [University of Florida, Gainesville; Rinzler, A. G. [University of Florida, Gainesville

    2011-01-01

    Low voltage, low power dissipation, high aperture ratio organic light emitting transistors are demonstrated. The high level of performance is enabled by a carbon nanotube source electrode that permits integration of the drive transistor and the organic light emitting diode into an efficient single stacked device. Given the demonstrated performance, this technology could break the technical logjam holding back widespread deployment of active matrix organic light emitting displays at flat panel screen sizes.

  6. Stepped inlet optical panel

    DOE Patents [OSTI]

    Veligdan, James T.

    2001-01-01

    An optical panel includes stacked optical waveguides having stepped inlet facets collectively defining an inlet face for receiving image light, and having beveled outlet faces collectively defining a display screen for displaying the image light channeled through the waveguides by internal reflection.

  7. Flat-Panel Cone-Beam Ct-Guided Radiofrequency Ablation of Very Small (≤1.5 cm) Liver Tumors: Technical Note on a Preliminary Experience

    SciTech Connect (OSTI)

    Cazzato, Roberto Luigi Buy, Xavier Alberti, Nicolas Fonck, Mariane; Grasso, Rosario Francesco; Palussière, Jean

    2015-02-15

    PurposeThe aim of the present study was to investigate the technical feasibility of flat-panel cone-beam CT (CBCT)-guided radiofrequency ablation (RFA) of very small (<1.5 cm) liver tumors.Materials and MethodsPatients included were candidates for hepatic percutaneous RFA as they had single biopsy-proven hepatic tumors sized ≤1.5 cm and poorly defined on ultrasonography. Following apnea induction, unenhanced CBCT scans were acquired and used to deploy the RF electrode with the aid of a virtual navigation system. If the tumor was not clearly identified on the unenhanced CBCT scan, a right retrograde arterial femoral access was established to carry out hepatic angiography and localize the tumor. Patients’ lesions and procedural variables were recorded and analyzed.ResultsThree patients (2 male and 1 female), aged 68, 76, and 87 years were included; 3 lesions (2 hepato-cellular carcinoma and 1 metastasis from colorectal cancer) were treated. One patient required hepatic angiography. Cycles of apnea used to acquire CBCT images and to deploy the electrode lasted <120 s. Mean fluoroscopic time needed to deploy the electrode was 36.6 ± 5.7 min. Mean overall procedural time was 66.0 ± 22.9 min. No peri- or post-procedural complications were noted. No cases of incomplete ablation were noted at 1-month follow-up.ConclusionPercutaneous CBCT-guided liver RFA with or without arterial hepatic angiography is technically feasible.

  8. Junction-based field emission structure for field emission display

    DOE Patents [OSTI]

    Dinh, Long N.; Balooch, Mehdi; McLean, II, William; Schildbach, Marcus A.

    2002-01-01

    A junction-based field emission display, wherein the junctions are formed by depositing a semiconducting or dielectric, low work function, negative electron affinity (NEA) silicon-based compound film (SBCF) onto a metal or n-type semiconductor substrate. The SBCF can be doped to become a p-type semiconductor. A small forward bias voltage is applied across the junction so that electron transport is from the substrate into the SBCF region. Upon entering into this NEA region, many electrons are released into the vacuum level above the SBCF surface and accelerated toward a positively biased phosphor screen anode, hence lighting up the phosphor screen for display. To turn off, simply switch off the applied potential across the SBCF/substrate. May be used for field emission flat panel displays.

  9. SU-E-I-53: Comparison of Kerma-Area-Product Between the Micro-Angiographic Fluoroscope (MAF) and a Flat Panel Detector (FPD) as Used in Neuro-Endovascular Procedures

    SciTech Connect (OSTI)

    Vijayan, S; Rana, V; Nagesh, S Setlur; Xiong, Z; Rudin, S; Bednarek, D

    2015-06-15

    Purpose: To determine the reduction of integral dose to the patient when using the micro-angiographic fluoroscope (MAF) compared to when using the standard flat-panel detector (FPD) for the techniques used during neurointerventional procedures. Methods: The MAF is a small field-of-view, high resolution x-ray detector which captures 1024 x 1024 pixels with an effective pixel size of 35μm and is capable of real-time imaging up to 30 frames per second. The MAF was used in neuro-interventions during those parts of the procedure when high resolution was needed and the FPD was used otherwise. The technique parameters were recorded when each detector was used and the kerma-area-product (KAP) per image frame was determined. KAP values were calculated for seven neuro interventions using premeasured calibration files of output as a function of kVp and beam filtration and included the attenuation of the patient table for the frontal projections to be more representative of integral patient dose. The air kerma at the patient entrance was multiplied by the beam area at that point to obtain the KAP values. The ranges of KAP values per frame were determined for the range of technique parameters used during the clinical procedures. To appreciate the benefit of the higher MAF resolution in the region of interventional activity, DA technique parameters were generally used with the MAF. Results: The lowest and highest values of KAP per frame for the MAF in DA mode were 4 and 50 times lower, respectively, compared to those of the FPD in pulsed fluoroscopy mode. Conclusion: The MAF was used in those parts of the clinical procedures when high resolution and image quality was essential. The integral patient dose as represented by the KAP value was substantially lower when using the MAF than when using the FPD due to the much smaller volume of tissue irradiated. This research was supported in part by Toshiba Medical Systems Corporation and NIH Grant R01EB002873.

  10. SU-D-204-05: Quantitative Comparison of a High Resolution Micro-Angiographic Fluoroscopic (MAF) Detector with a Standard Flat Panel Detector (FPD) Using the New Metric of Generalized Measured Relative Object Detectability (GM-ROD)

    SciTech Connect (OSTI)

    Russ, M; Ionita, C; Bednarek, D; Rudin, S

    2015-06-15

    Purpose: In endovascular image-guided neuro-interventions, visualization of fine detail is paramount. For example, the ability of the interventionist to visualize the stent struts depends heavily on the x-ray imaging detector performance. Methods: A study to examine the relative performance of the high resolution MAF-CMOS (pixel size 75µm, Nyquist frequency 6.6 cycles/mm) and a standard Flat Panel Detector (pixel size 194µm, Nyquist frequency 2.5 cycles/mm) detectors in imaging a neuro stent was done using the Generalized Measured Relative Object Detectability (GM-ROD) metric. Low quantum noise images of a deployed stent were obtained by averaging 95 frames obtained by both detectors without changing other exposure or geometric parameters. The square of the Fourier transform of each image is taken and divided by the generalized normalized noise power spectrum to give an effective measured task-specific signal-to-noise ratio. This expression is then integrated from 0 to each of the detector’s Nyquist frequencies, and the GM-ROD value is determined by taking a ratio of the integrals for the MAF-CMOS to that of the FPD. The lower bound of integration can be varied to emphasize high frequencies in the detector comparisons. Results: The MAF-CMOS detector exhibits vastly superior performance over the FPD when integrating over all frequencies, yielding a GM-ROD value of 63.1. The lower bound of integration was stepped up in increments of 0.5 cycles/mm for higher frequency comparisons. As the lower bound increased, the GM-ROD value was augmented, reflecting the superior performance of the MAF-CMOS in the high frequency regime. Conclusion: GM-ROD is a versatile metric that can provide quantitative detector and task dependent comparisons that can be used as a basis for detector selection. Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.

  11. Solar collector panels (process-method). Rainwater collection and storage

    SciTech Connect (OSTI)

    Mowery, J.W.

    1981-10-15

    A process for producing panels for solar heating of potable water is described. The panels have PVC tubing flat-coiled into square or rectangular shapes. Also described is a cistern for collecting and storing rainwater. (LEW)

  12. Flat | Open Energy Information

    Open Energy Info (EERE)

    ENERGYGeothermal Home Print PDF Flat Dictionary.png Flat: A relatively smooth landscape with no topographic relief Other definitions:Wikipedia Reegle Topographic Features...

  13. Interactive display system having a digital micromirror imaging device

    DOE Patents [OSTI]

    Veligdan, James T.; DeSanto, Leonard; Kaull, Lisa; Brewster, Calvin

    2006-04-11

    A display system includes a waveguide optical panel having an inlet face and an opposite outlet face. A projector cooperates with a digital imaging device, e.g. a digital micromirror imaging device, for projecting an image through the panel for display on the outlet face. The imaging device includes an array of mirrors tiltable between opposite display and divert positions. The display positions reflect an image light beam from the projector through the panel for display on the outlet face. The divert positions divert the image light beam away from the panel, and are additionally used for reflecting a probe light beam through the panel toward the outlet face. Covering a spot on the panel, e.g. with a finger, reflects the probe light beam back through the panel toward the inlet face for detection thereat and providing interactive capability.

  14. Interconnection Panel

    Office of Energy Efficiency and Renewable Energy (EERE)

    Presentation—given at at the Fall 2012 Federal Utility Partnership Working Group (FUPWG) meeting—discusses the interconnection panel, including an overview of the generation interconnection process (GIP), and interconnection agreements and their terms.

  15. Advisory Panels

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Advisory Panels Print ALS Advisory Panels Many people are involved in developing and expanding the scientific and user programs at the ALS. Members of the committees listed below are either appointed or elected by the user community and/or by ALS or Berkeley Lab management to provide a wide base of communication on issues concerning all aspects of ALS operations and development. Additional information about the role and responsibilities of each group, its membership, and contact information is

  16. Advisory Panels

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Advisory Panels Print ALS Advisory Panels Many people are involved in developing and expanding the scientific and user programs at the ALS. Members of the committees listed below are either appointed or elected by the user community and/or by ALS or Berkeley Lab management to provide a wide base of communication on issues concerning all aspects of ALS operations and development. Additional information about the role and responsibilities of each group, its membership, and contact information is

  17. Windy Flats | Open Energy Information

    Open Energy Info (EERE)

    Flats Jump to: navigation, search Name Windy Flats Facility Windy Flats Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Cannon Power Group...

  18. Development of a plasma panel radiation detector

    SciTech Connect (OSTI)

    Ball, Robert; Beene, James R; Ben Moshe, M.; Benhammou, Yan; Bensimon, B; Chapman, J. Wehrley; Etzion, E; Ferretti, Claudio; Friedman, Dr. Peter S.; Levin, Daniel S.; Silver, Yiftah; Weaverdyck, Curtis; Wetzel, R.; Zhou, Bing; Anderson, T; McKinny, K; Bentefour, E

    2014-11-01

    This article reports on the development and experimental results of commercial plasma display panels adapted for their potential use as micropattern gas radiation detectors. The plasma panel sensor (PPS) design and materials include glass substrates, metal electrodes and inert gas mixtures which provide a physically robust, hermetically sealed device. Plasma display panels used as detectors were tested with cosmic ray muons, beta rays and gamma rays, protons, and thermal neutrons. The results demonstrated rise times and time resolution of a few nanoseconds, as well as sub-millimeter spatial resolution compatible with the pixel pitch.

  19. DHS Flat Stanley Project

    Broader source: Energy.gov [DOE]

    To provide information on the DHS Flat Stanley Project. The goal of the project is to help kids learn about the importance of cybersecurity.

  20. Plasma Panel Based Radiation Detectors

    SciTech Connect (OSTI)

    Friedman, Dr. Peter S.; Varner Jr, Robert L; Ball, Robert; Beene, James R; Ben Moshe, M.; Benhammou, Yan; Chapman, J. Wehrley; Etzion, E; Ferretti, Claudio; Bentefour, E; Levin, Daniel S.; Moshe, M.; Silver, Yiftah; Weaverdyck, Curtis; Zhou, Bing

    2013-01-01

    The plasma panel sensor (PPS) is a gaseous micropattern radiation detector under current development. It has many operational and fabrication principles common to plasma display panels (PDPs). It comprises a dense matrix of small, gas plasma discharge cells within a hermetically sealed panel. As in PDPs, it uses non-reactive, intrinsically radiation-hard materials such as glass substrates, refractory metal electrodes, and mostly inert gas mixtures. We are developing these devices primarily as thin, low-mass detectors with gas gaps from a few hundred microns to a few millimeters. The PPS is a high gain, inherently digital device with the potential for fast response times, fine position resolution (< 50 m RMS) and low cost. In this paper we report here on prototype PPS experimental results in detecting betas, protons and cosmic muons, and we extrapolate on the PPS potential for applications including detection of alphas, heavy-ions at low to medium energy, thermal neutrons and X-rays.

  1. SHEPHERDS FLAT | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    SHEPHERDS FLAT SHEPHERDS FLAT DOE-LPO_Project-Posters_WIND_Shepherds-Flat.pdf (381.97 KB) More Documents & Publications EIS-0183: Record of Decision EIS-0183: Record of Decision EIS-0419: Supplement Analysis

  2. Fabric panel clean change-out frame

    DOE Patents [OSTI]

    Brown, Ronald M.

    1995-01-31

    A fabric panel clean change-out frame, for use on a containment structure having rigid walls, is formed of a compression frame and a closure panel. The frame is formed of elongated spacers, each carrying a plurality of closely spaced flat springs, and each having a hooked lip extending on the side of the spring facing the spacer. The closure panel is includes a perimeter frame formed of flexible, wedge-shaped frame members that are receivable under the springs to deflect the hooked lips. A groove on the flexible frame members engages the hooked lips and locks the frame members in place under the springs. A flexible fabric panel is connected to the flexible frame members and closes its center.

  3. Rocky flats teams forming

    SciTech Connect (OSTI)

    1994-08-01

    Bidding teams are shaping up to go after the $3.5-billion, five-year contract to manage ongoing operations and cleanup of the US Dept. of Energy`s Rocky Flats nuclear weapon plant near Denver.

  4. Rocky Flats Overview

    Broader source: Energy.gov [DOE]

    At the August 20, 2014 NNMCAB Site Tour Scott Surovchak DOE, Provided Information on Activities that Took Place on the Rocky Flats Site. Information on the Clean-up Process was Also Given.

  5. Method of fabrication of display pixels driven by silicon thin film transistors

    DOE Patents [OSTI]

    Carey, Paul G.; Smith, Patrick M.

    1999-01-01

    Display pixels driven by silicon thin film transistors are fabricated on plastic substrates for use in active matrix displays, such as flat panel displays. The process for forming the pixels involves a prior method for forming individual silicon thin film transistors on low-temperature plastic substrates. Low-temperature substrates are generally considered as being incapable of withstanding sustained processing temperatures greater than about 200.degree. C. The pixel formation process results in a complete pixel and active matrix pixel array. A pixel (or picture element) in an active matrix display consists of a silicon thin film transistor (TFT) and a large electrode, which may control a liquid crystal light valve, an emissive material (such as a light emitting diode or LED), or some other light emitting or attenuating material. The pixels can be connected in arrays wherein rows of pixels contain common gate electrodes and columns of pixels contain common drain electrodes. The source electrode of each pixel TFT is connected to its pixel electrode, and is electrically isolated from every other circuit element in the pixel array.

  6. Real-time graphic display utility for nuclear safety applications

    SciTech Connect (OSTI)

    Yang, S.; Huang, X.; Taylor, J.; Stevens, J.; Gerardis, T.; Hsu, A.; McCreary, T.

    2006-07-01

    With the increasing interests in the nuclear energy, new nuclear power plants will be constructed and licensed, and older generation ones will be upgraded for assuring continuing operation. The tendency of adopting the latest proven technology and the fact of older parts becoming obsolete have made the upgrades imperative. One of the areas for upgrades is the older CRT display being replaced by the latest graphics displays running under modern real time operating system (RTOS) with safety graded modern computer. HFC has developed a graphic display utility (GDU) under the QNX RTOS. A standard off-the-shelf software with a long history of performance in industrial applications, QNX RTOS used for safety applications has been examined via a commercial dedication process that is consistent with the regulatory guidelines. Through a commercial survey, a design life cycle and an operating history evaluation, and necessary tests dictated by the dedication plan, it is reasonably confirmed that the QNX RTOS was essentially equivalent to what would be expected in the nuclear industry. The developed GDU operates and communicates with the existing equipment through a dedicated serial channel of a flat panel controller (FPC) module. The FPC module drives a flat panel display (FPD) monitor. A touch screen mounted on the FPD serves as the normal operator interface with the FPC/FPD monitor system. The GDU can be used not only for replacing older CRTs but also in new applications. The replacement of the older CRT does not disturb the function of the existing equipment. It not only provides modern proven technology upgrade but also improves human ergonomics. The FPC, which can be used as a standalone controller running with the GDU, is an integrated hardware and software module. It operates as a single board computer within a control system, and applies primarily to the graphics display, targeting, keyboard and mouse. During normal system operation, the GDU has two sources of data

  7. Final Report of Project Nanometer Structures for Fuel Cells and Displays, etc.

    SciTech Connect (OSTI)

    Ji, Qing

    2011-12-15

    Low-energy ion beam bombardment induced self-assembly has been used to form various periodic nano-size wave-ordered structures (WOS). Such WOS can be used as hard etching masks to produce nanowire arrays, trenches etc., on other materials by means of traditional etching or ion sputtering. These periodic nano-size structures have a wide range of applications, including flat panel displays, optical electronics, and clean energy technologies (solar and fuel cells, lithium batteries). In order to achieve high throughput of the above processes, a large area RF-driven multicusp nitrogen ion source has been developed for the application of nitrogen ion beam induced surface modification. An integrated ion beam system, which can house either a large area RF-driven multicusp ion source or a commercially available microwave ion source (Roth & Rau AG Tamiris 400-f) have been designed, manufactured, assembled, and tested.

  8. Diesel prices flat

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices flat The U.S. average retail price for on-highway diesel fuel saw no movement from last week. Prices remained flat at $3.89 a gallon on Monday, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the West Coast states at 4.05 a gallon, up 2-tenths of a penny from a week ago. Prices were lowest in the Gulf Coast region at 3.80 a gallon, up 3-tenths of a penny

  9. Is flat fair?

    SciTech Connect (OSTI)

    Bunzl, Martin

    2010-07-15

    Dynamic pricing holds out the promise of shifting peak demand as well as reducing overall demand. But it also raises thorny issues of fairness. All practical pricing systems involve tradeoffs between equity and efficiency. I examine the circumstances under which equity ought to be allowed to trump efficiency and whether or not this constitutes a defense of flat pricing. (author)

  10. Prismatic optical display

    DOE Patents [OSTI]

    Veligdan, James T.; DeSanto, Leonard; Brewster, Calvin

    2004-06-29

    A spatially modulated light beam is projected, reflected, and redirected through a prismatic optical panel to form a video image for direct viewing thereon.

  11. Interactive optical panel

    DOE Patents [OSTI]

    Veligdan, James T.

    1995-10-03

    An interactive optical panel assembly 34 includes an optical panel 10 having a plurality of ribbon optical waveguides 12 stacked together with opposite ends thereof defining panel first and second faces 16, 18. A light source 20 provides an image beam 22 to the panel first face 16 for being channeled through the waveguides 12 and emitted from the panel second face 18 in the form of a viewable light image 24a. A remote device 38 produces a response beam 40 over a discrete selection area 36 of the panel second face 18 for being channeled through at least one of the waveguides 12 toward the panel first face 16. A light sensor 42,50 is disposed across a plurality of the waveguides 12 for detecting the response beam 40 therein for providing interactive capability.

  12. Interactive optical panel

    DOE Patents [OSTI]

    Veligdan, J.T.

    1995-10-03

    An interactive optical panel assembly includes an optical panel having a plurality of ribbon optical waveguides stacked together with opposite ends thereof defining panel first and second faces. A light source provides an image beam to the panel first face for being channeled through the waveguides and emitted from the panel second face in the form of a viewable light image. A remote device produces a response beam over a discrete selection area of the panel second face for being channeled through at least one of the waveguides toward the panel first face. A light sensor is disposed across a plurality of the waveguides for detecting the response beam therein for providing interactive capability. 10 figs.

  13. Low-cost solar flat-plate-collector development

    SciTech Connect (OSTI)

    Wilhelm, W.G.

    1981-01-01

    Cost goals were developed for the collector which led to the rejection of conventional approaches and to the exploration of thin-film technology. A thin-film sola absorber suited for high-speed continous-roll manufacture at low cost was designed. The absorber comprises two sheets of aluminum-foil/polymeric-material laminate bonded together at intervals to form channels with water as the heat transfer fluid. Several flat-plate panels were fabricated and tested. (MHR)

  14. Diesel prices flat nationally

    U.S. Energy Information Administration (EIA) Indexed Site

    Diesel prices flat nationally The U.S. average retail price for on-highway diesel fuel remained the same from a week ago at $3.98 a gallon on Monday, based on the weekly price survey by the U.S. Energy Information Administration. Diesel prices were highest in the West Coast states at 4.14 a gallon, up 1.4 cents from a week ago. Prices were lowest in the Gulf Coast region at 3.90 a gallon, up a tenth of a penny.

  15. Compressive and shear buckling analysis of metal matrix composite sandwich panels under different thermal environments

    SciTech Connect (OSTI)

    Ko, W.L.; Jackson, R.H.

    1993-06-01

    Combined inplane compressive and shear buckling analysis was conducted on flat rectangular sandwich panels using the Raleigh-Ritz minimum energy method with a consideration of transverse shear effect of the sandwich core. The sandwich panels were fabricated with titanium honeycomb core and laminated metal matrix composite face sheets. The results show that slightly slender (along unidirectional compressive loading axis) rectangular sandwich panels have the most desirable stiffness-to-weight ratios for aerospace structural applications; the degradation of buckling strength of sandwich panels with rising temperature is faster in shear than in compression; and the fiber orientation of the face sheets for optimum combined-load buckling strength of sandwich panels is a strong function of both loading condition and panel aspect ratio. Under the same specific weight and panel aspect ratio, a sandwich panel with metal matrix composite face sheets has much higher buckling strength than one having monolithic face sheets.

  16. Proposal Study Panels

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  17. Proposal Study Panels

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  18. Proposal Study Panels

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  19. Proposal Study Panels

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proposal Study Panels Print Two Proposal Study Panels (PSPs) exist at the ALS: one for the general sciences and one for structural biology. The role of the PSPs is desribed in User Policy. Note: Users are urged NOT to contact any members of the panels directly. Current members of the general sciences PSP, as of April 2016, are Masa Fukuto, Brookhaven National Laboratory Carol Hirschmugl, University of Wisconsin, Milwaukee Peter Johnson (chair), Brookhaven National Laboratory Apurva Mehta, SLAC

  20. Solar reflection panels

    DOE Patents [OSTI]

    Diver, Jr., Richard B.; Grossman, James W.; Reshetnik, Michael

    2006-07-18

    A solar collector comprising a glass mirror, and a composite panel, wherein the back of the mirror is affixed to a front surface of the composite panel. The composite panel comprises a front sheet affixed to a surface of a core material, preferably a core material comprising a honeycomb structure, and a back sheet affixed to an opposite surface of the core material. The invention may further comprise a sealing strip, preferably comprising EPDM, positioned between the glass mirror and the front surface of the composite panel. The invention also is of methods of making such solar collectors.

  1. Hydrogen Safety Panel

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    or otherwise restricted information. Project ID: scs07weiner PNNL-SA-65397 2 IEA HIA Task 19 Working Group Hydrogen Safety Training Props Hydrogen Safety Panel Incident...

  2. Cytoplasmic bacteriophage display system

    DOE Patents [OSTI]

    Studier, F.W.; Rosenberg, A.H.

    1998-06-16

    Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest. 1 fig.

  3. Cytoplasmic bacteriophage display system

    DOE Patents [OSTI]

    Studier, F. William; Rosenberg, Alan H.

    1998-06-16

    Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest.

  4. SHEPHERDS FLAT | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    It is expected to prevent 1,000,000 metric tons of carbon dioxide emissions annually. PROJECT STATISTICS: SHEPHERDS FLAT PROJECT SUMMARY OWNER Caithness Energy, LLC LOCATIONS ...

  5. Thin film polycrystalline silicon: Promise and problems in displays and solar cells

    SciTech Connect (OSTI)

    Fonash, S.J.

    1995-08-01

    Thin film polycrystalline Si (poly-Si) with its carrier mobilities, potentially good stability, low intragrain defect density, compatibility with silicon processing, and ease of doping activation is an interesting material for {open_quotes}macroelectronics{close_quotes} applications such as TFTs for displays and solar cells. The poly-Si films needed for these applications can be ultra-thin-in the 500{Angstrom} to 1000{Angstrom} thickness range for flat panel display TFTs and in the 4{mu}m to 10{mu}m thickness range for solar cells. Because the films needed for these microelectronics applications can be so thin, an effective approach to producing the films is that of crystallizing a-Si precursor material. Unlike cast materials, poly-Si films made this way can be produced using low temperature processing. Unlike deposited poly-Si films, these crystallized poly-Si films can have grain widths that are much larger than the film thickness and almost atomically smooth surfaces. This thin film poly-Si crystallized from a-Si precursor films, and its promise and problems for TFTs and solar cells, is the focus of this discussion.

  6. Optical panel system including stackable waveguides

    DOE Patents [OSTI]

    DeSanto, Leonard; Veligdan, James T.

    2007-03-06

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  7. Optical panel system including stackable waveguides

    DOE Patents [OSTI]

    DeSanto, Leonard; Veligdan, James T.

    2007-11-20

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  8. Solar control panel

    SciTech Connect (OSTI)

    Hoyois, J.C.

    1984-12-11

    A glazing panel for transmitting radiant energy including visible light energy which includes first and second glass sheets supported in spaced relation. The first glass sheet has an oxide coated surface which defines an exterior surface of the panel and a gold coating on the surface which faces the second glass sheet.

  9. Flexible optical panel

    DOE Patents [OSTI]

    Veligdan, James T.

    2001-01-01

    A flexible optical panel includes laminated optical waveguides, each including a ribbon core laminated between cladding, with the core being resilient in the plane of the core for elastically accommodating differential movement thereof to permit winding of the panel in a coil.

  10. Technical Review Panel Report

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    TRP Report v7, 12 Aug 2012 TRP Report Final December 2012 Advanced Reactor Concepts Technical Review Panel Report Evaluation and Identification of future R&D on eight Advanced Reactor Concepts, conducted April - September 2012 December 2012 Public release version 2 Public release version 3 Table of Contents Summary ................................................................................................................................... 4 1. Overview of the Technical Review Panel

  11. Interactive display system having a scaled virtual target zone

    DOE Patents [OSTI]

    Veligdan, James T.; DeSanto, Leonard

    2006-06-13

    A display system includes a waveguide optical panel having an inlet face and an opposite outlet face. A projector and imaging device cooperate with the panel for projecting a video image thereon. An optical detector bridges at least a portion of the waveguides for detecting a location on the outlet face within a target zone of an inbound light spot. A controller is operatively coupled to the imaging device and detector for displaying a cursor on the outlet face corresponding with the detected location of the spot within the target zone.

  12. Absolute calibration of optical flats

    DOE Patents [OSTI]

    Sommargren, Gary E.

    2005-04-05

    The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

  13. New generation of panel programs for radiation-diffraction problems

    SciTech Connect (OSTI)

    Breit, S.R.; Sclavounos, P.D.; Newman, J.N.

    1985-01-01

    Two computer programs were developed to analyze wave interactions with three-dimensional bodies. The first program, for spheroidal bodies, uses special panels to represent the exact body shape. The second program, based on flat quadrilateral panels, is applicable to arbitrary bodies. Green's theorem is employed with sources and normal dipoles on the body surface, and the subroutine FINGREEN is used to evaluate these singularities. Extensive comparisons are made for the heave added-mass and damping coefficients of a spheroid and an axisymmetric cylinder. Collocation and Galerkin techniques are compared, and Richardson extrapolation is shown to be an effective method for improving the accuracy without increasing the number of panels. Error tables are presented for these different approaches to show the effect on the final accuracy of varying the number of panels. Special studies are made in the vicinity of the first irregular frequency.

  14. Public Displays of Efficiency

    Broader source: Energy.gov [DOE]

    Imagine if an electronic billboard displayed how much energy you used this morning, or you stepped outside to see your energy savings painted on the street for passersby to see. For some Better Buildings neighborhoods, these public displays are popping up—and they're helping call attention to saving energy.

  15. Polyplanar optical display electronics

    SciTech Connect (OSTI)

    DeSanto, L.; Biscardi, C.

    1997-07-01

    The Polyplanar Optical Display (POD) is a unique display screen which can be used with any projection source. The prototype ten inch display is two inches thick and has a matte black face which allows for high contrast images. The prototype being developed is a form, fit and functional replacement display for the B-52 aircraft which uses a monochrome ten-inch display. In order to achieve a long lifetime, the new display uses a 100 milliwatt green solid-state laser (10,000 hr. life) at 532 nm as its light source. To produce real-time video, the laser light is being modulated by a Digital Light Processing (DLP{trademark}) chip manufactured by Texas Instruments. In order to use the solid-state laser as the light source and also fit within the constraints of the B-52 display, the Digital Micromirror Device (DMD{trademark}) circuit board is removed from the Texas Instruments DLP light engine assembly. Due to the compact architecture of the projection system within the display chassis, the DMD{trademark} chip is operated remotely from the Texas Instruments circuit board. The authors discuss the operation of the DMD{trademark} divorced from the light engine and the interfacing of the DMD{trademark} board with various video formats (CVBS, Y/C or S-video and RGB) including the format specific to the B-52 aircraft. A brief discussion of the electronics required to drive the laser is also presented.

  16. Solar heating panel

    SciTech Connect (OSTI)

    Keefe, R.A.

    1983-08-09

    A method of maintaining the temperature of a solar heating panel with glazing below about 220/sup 0/ utilizes convention cooling, where it is essential to the success of the method that the glazing be at least two inches above the upper surface of the collector. A panel of unitary construction of essentially the same plastic material which is an embodiment of the method can withstand the normal operating conditions to which such panels are subjected without thermal degradation of the plastic nor danger of rupture attending loss of physical integrity at excessive temperatures.

  17. Interactive display system having a matrix optical detector

    DOE Patents [OSTI]

    Veligdan, James T.; DeSanto, Leonard

    2007-01-23

    A display system includes a waveguide optical panel having an inlet face and an opposite outlet face. An image beam is projected across the inlet face laterally and transversely for display on the outlet face. An optical detector including a matrix of detector elements is optically aligned with the inlet face for detecting a corresponding lateral and transverse position of an inbound light spot on the outlet face.

  18. Residential Photovoltaic Solar Panels

    Office of Energy Efficiency and Renewable Energy (EERE)

    This b-roll footage shows exteriors of two Colorado residences that use photovoltaic panels to collect renewable solar energy, thereby reducing their dependence on external electric power. Net...

  19. Solar collector panel

    SciTech Connect (OSTI)

    Gessford, J.D.

    1983-03-01

    A solar collector panel and a method of making the collector panel. The solar collector panel has four layers of fiberglass mat which are each saturated with a catalyzed liquiform resin. Between the first two layers, unimpregnated kraft honeycomb paper having an open cellular structure is placed so as to form a resinated honeycomb core between these first two layers. A plurality of fluid channels are then bonded to the second layer of resin saturated fiberglass mat. The fluid channels are made of a material having a coefficient of thermal expansion essentially equal to that of the fiberglass mat. The third layer of resinsaturated fiberglass mat is placed over the fluid channels. A second layer of kraft honeycomb paper is then placed between the third and fourth layers of resin-saturated fiberglass mat, and a clear gel coat mixed with an ultraviolet inhibitor solution is rolled out over the top of the solar collector panel to partially screen out ultraviolet rays.

  20. Hexagon solar power panel

    DOE Patents [OSTI]

    Rubin, Irwin

    1978-01-01

    A solar energy panel comprises a support upon which silicon cells are arrayed. The cells are wafer thin and of two geometrical types, both of the same area and electrical rating, namely hexagon cells and hourglass cells. The hourglass cells are composites of half hexagons. A near perfect nesting relationship of the cells achieves a high density packing whereby optimum energy production per panel area is achieved.

  1. Gas filled panel insulation

    DOE Patents [OSTI]

    Griffith, B.T.; Arasteh, D.K.; Selkowitz, S.E.

    1993-12-14

    A structural or flexible highly insulative panel which may be translucent, is formed from multi-layer polymeric material in the form of an envelope surrounding a baffle. The baffle is designed so as to minimize heat transfer across the panel, by using material which forms substantially closed spaces to suppress convection of the low conductivity gas fill. At least a portion of the baffle carries a low emissivity surface for suppression of infrared radiation. 18 figures.

  2. Gas filled panel insulation

    DOE Patents [OSTI]

    Griffith, Brent T.; Arasteh, Dariush K.; Selkowitz, Stephen E.

    1993-01-01

    A structural or flexible highly insulative panel which may be translucent, is formed from multi-layer polymeric material in the form of an envelope surrounding a baffle. The baffle is designed so as to minimize heat transfer across the panel, by using material which forms substantially closed spaces to suppress convection of the low conductivity gas fill. At least a portion of the baffle carries a low emissivity surface for suppression of infrared radiation.

  3. Flat Ridge Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    Flat Ridge Wind Farm Jump to: navigation, search Name Flat Ridge Wind Farm Facility Flat Ridge Wind Farm Sector Wind energy Facility Type Commercial Scale Wind Facility Status In...

  4. Project Profile: High Performance Reflector Panels for CSP Assemblies |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Concentrating Solar Power » Project Profile: High Performance Reflector Panels for CSP Assemblies Project Profile: High Performance Reflector Panels for CSP Assemblies PPG logo PPG, under the CSP R&D FOA, is aiming to develop and commercialize large-area second-surface glass mirrors that are superior in value, cost, and performance, to existing mirrors on the market today. Approach Photo of a metal stand with flat square-shaped pieces lined up in three rows. This

  5. Automatic ranging circuit for a digital panel meter

    DOE Patents [OSTI]

    Mueller, Theodore R.; Ross, Harley H.

    1976-01-01

    This invention relates to a range changing circuit that operates in conjunction with a digital panel meter of fixed sensitivity. The circuit decodes the output of the panel meter and uses that information to change the gain of an input amplifier to the panel meter in order to insure that the maximum number of significant figures is always displayed in the meter. The circuit monitors five conditions in the meter and responds to any of four combinations of these conditions by means of logic elements to carry out the function of the circuit.

  6. Windy Flats IIa extension | Open Energy Information

    Open Energy Info (EERE)

    IIa extension Jump to: navigation, search Name Windy Flats IIa extension Facility Windy Flats IIa extension Sector Wind energy Facility Type Commercial Scale Wind Facility Status...

  7. Windy Flats Phase III | Open Energy Information

    Open Energy Info (EERE)

    Phase III Jump to: navigation, search Name Windy Flats Phase III Facility Windy Flats Phase III Sector Wind energy Facility Type Commercial Scale Wind Facility Status Proposed...

  8. Flat Water Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    Water Wind Farm Jump to: navigation, search Name Flat Water Wind Farm Facility Flat Water Wind Farm Sector Wind energy Facility Type Commercial Scale Wind Facility Status In...

  9. DOE - Office of Legacy Management -- Rocky Flats External Resources

    Office of Legacy Management (LM)

    Rocky Flats Site, Colorado External Resources Rocky Flats Stewardship Council Disclaimer Rocky Flats Cold War Museum Disclaimer U.S. Fish and Wildlife Service Rocky Flats National ...

  10. Revegetation of the Rocky Flats Site | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Revegetation of the Rocky Flats Site Revegetation of the Rocky Flats Site Revegetation of the Rocky Flats, Colorado Site PDF icon Revegetation of the Rocky Flats Site More...

  11. Oven wall panel construction

    DOE Patents [OSTI]

    Ellison, Kenneth; Whike, Alan S.

    1980-04-22

    An oven roof or wall is formed from modular panels, each of which comprises an inner fabric and an outer fabric. Each such fabric is formed with an angle iron framework and somewhat resilient tie-bars or welded at their ends to flanges of the angle irons to maintain the inner and outer frameworks in spaced disposition while minimizing heat transfer by conduction and permitting some degree of relative movement on expansion and contraction of the module components. Suitable thermal insulation is provided within the module. Panels or skins are secured to the fabric frameworks and each such skin is secured to a framework and projects laterally so as slidingly to overlie the adjacent frame member of an adjacent panel in turn to permit relative movement during expansion and contraction.

  12. Advanced solar panel designs

    SciTech Connect (OSTI)

    Ralph, E.L.; Linder, E.

    1995-10-01

    This paper describes solar cell panel designs that utilize new high efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

  13. Panel 3 - characterization

    SciTech Connect (OSTI)

    Erck, R.A.; Erdemir, A.; Janghsing Hsieh; Lee, R.H.; Xian Zheng Pan; Deming Shu; Feldman, A.; Glass, J.T.; Kleimer, R.; Lawton, E.A.

    1993-01-01

    The task of this panel was to identify and prioritize needs in the area of characterization of diamond and diamond-like-carbon (DLC) films for use in the transportation industry. Until recent advances in production of inexpensive films of diamonds and DLC, it was not feasible that these materials could be mass produced. The Characterization Panel is restricting itself to identifying needs in areas that would be most useful to manufacturers and users in producing and utilizing diamond and DLC coatings in industry. These characterization needs include in-situ monitoring during growth, relation of structure to performance, and standards and definitions.

  14. Industry Partners Panel

    Office of Energy Efficiency and Renewable Energy (EERE)

    Industry Panel presenters include: Michael G. Andrew, Director - Academic and Technical Programs, Advanced Products and Materials, Johnson Controls Power Solutions Michael A. Fetcenko, Vice President and Managing Director, BASF Battery Materials – Ovonic, BASF Corporation Adam Kahn, Founder and CEO, AKHAN Technologies, Inc. Stephen E. Zimmer, Executive Director, United States Council for Automotive Research (USCAR)

  15. Solar water heating panel

    SciTech Connect (OSTI)

    Burke, B.G.

    1984-10-02

    The present invention discloses a solar water heating panel and method of constructing such a solar panel from a pair of thin sheets bonded together around their peripheral edges and having at least one of the sheets formed with resiliently flexible areas defined by a plurality of abutting concave hexagonal areas or zones. The center of each hexagonal zone is formed as a dimple, concave with respect to the opposite sheet, whose radius of curvature is greater than the radius of an inscribed circle within said zone. The abutting zones between each hexagonal zone are formed convex relative to the opposite sheet and have a radius less than that of an inscribed circle. In a preferred form, the sheets are joined together at the center of alternate spaced-apart hexagonal areas. In this way, except for the centers bonded near the panel edges, each joined hexagonal center is surrounded by six unjoined areas to form both transverse and longitudinal flow passages through the panel.

  16. Solar heating panel

    SciTech Connect (OSTI)

    Ellsworth, R.L.

    1983-01-18

    A solar heating panel for collecting solar heat energy and method for making same having a heat insulative substrate with a multiplicity of grooves and structural supporting ribs formed therein covered by a thin, flexible heat conductive film to form fluid conducting channels which in turn are connected to manifolds from which fluid is directed into the channels and heated fluid is removed therefrom.

  17. Solar Panels Plus LLC | Open Energy Information

    Open Energy Info (EERE)

    Panels Plus LLC Jump to: navigation, search Name: Solar Panels Plus LLC Place: Chesapeake, Virginia Zip: 23320 Sector: Solar Product: Solar Panels Plus LLC distributes solar energy...

  18. Heat transfer panel and method

    SciTech Connect (OSTI)

    Clark, P.C.

    1984-09-25

    A durable, low-cost, heat transfer panel of the type typically employed as a solar energy collector is disclosed. The panel includes a flow channel defining structure, preferably formed as a corrugated sheet and a superimposed flexible membrane, to which manifolds or headers are secured. The manifolds have mating corrugated surfaces that are interengaged with the corrugations on the panel sheet to provide transverse rigidity to the overall panel structure as well as distribution of heat transfer fluid to and from the panel. Modified forms of the panel are disclosed in which the panel includes a selective absorber and a venting structure. A method for blow-molding the manifold into mating interengagement with the corrugated support sheet of the panel is also disclosed.

  19. Innovative Ballasted Flat Roof Solar PV Racking System

    SciTech Connect (OSTI)

    Peek, Richard T.

    2015-01-23

    The objective of this project was to reduce the cost of racking for PV solar on flat commercial rooftops. Cost reductions would come from both labor savings and material savings related to the installation process. The rack would need to accommodate the majority of modules available on the market. Cascade Engineering has a long history of converting traditional metal type applications over to plastic. Injection molding of plastics have numerous advantages including selection of resin for the application, placing the material exactly where it is needed, designing in features that will speed up the installation process, and weight reduction of the array. A plastic rack would need to meet the requirements of UL2703, Mounting systems, mounting devices, clamping/retention devices, and ground lugs for use with flat-plate photovoltaic modules and panels. Comparing original data to the end of project racking design, racking material costs were reduced 50% and labor costs reduced 64%. The racking product accommodates all 60 and 72 cell panels on the market, meets UL2703 requirements, contributes only 1.3 pounds per square foot of weight to the array, requires little ballast to secure the array, automatically grounds the module when the module is secured, stacks/nests well for shipping/fewer lifts to the roof, provides integrated wire routing, allows water to drain on the roof, and accommodates various seismic roof connections. Project goals were achieved as noted in the original funding application.

  20. Solar collector panel

    SciTech Connect (OSTI)

    Gessford, J.D.

    1980-11-11

    A solar collector panel and method of making same are disclosed. The solar collector panel has four layers of fiberglass mat which are each saturated with a catalyzed liquiform resin. Between the first two layers, unimpregnated kraft honeycomb paper having an open cellular structure is placed so as to form a resinated honeycomb core between these first two layers. A black gel coat is sprayed onto the second layer of resin-saturated fiberglass mat and a plurality of copper tubes are then placed onto the black gel coat so as to be bonded in heat-transfer relation thereto. The third layer of resin-saturated fiberglass mat is draped over the copper tubes so as to insulate them. A second layer of kraft honeycomb paper is then placed between the third and forth layers of resin-saturated fiberglass mat, and a clear gel coat mixed with an ultraviolet inhibitor solution is rolled out over the top of the solar collector panel to partially screen out ultraviolet rays.

  1. Lighted display devices for producing static or animated visual displays, including animated facial features

    DOE Patents [OSTI]

    Heilbron, Valerie J; Clem, Paul G; Cook, Adam Wade

    2014-02-11

    An illuminated display device with a base member with a plurality of cavities therein. Illumination devices illuminate the cavities and emit light through an opening of the cavities in a pattern, and a speaker can emit sounds in synchronization with the pattern. A panel with translucent portions can overly the base member and the cavities. An animated talking character can have an animated mouth cavity complex with multiple predetermined mouth lighting configurations simulative of human utterances. The cavities can be open, or optical waveguide material or positive members can be disposed therein. Reflective material can enhance internal reflectance and light emission.

  2. Graphene folding on flat substrates

    SciTech Connect (OSTI)

    Chen, Xiaoming; Zhao, Yadong; Ke, Changhong; Zhang, Liuyang; Wang, Xianqiao

    2014-10-28

    We present a combined experimental-theoretical study of graphene folding on flat substrates. The structure and deformation of the folded graphene sheet are experimentally characterized by atomic force microscopy. The local graphene folding behaviors are interpreted based on nonlinear continuum mechanics modeling and molecular dynamics simulations. Our study on self-folding of a trilayer graphene sheet reports a bending stiffness of about 6.57?eV, which is about four times the reported values for monolayer graphene. Our results reveal that an intriguing free sliding phenomenon occurs at the interlayer van der Waals interfaces during the graphene folding process. This work demonstrates that it is a plausible venue to quantify the bending stiffness of graphene based on its self-folding conformation on flat substrates. The findings reported in this work are useful to a better understanding of the mechanical properties of graphene and in the pursuit of its applications.

  3. Corrugated cover plate for flat plate collector

    DOE Patents [OSTI]

    Hollands, K. G. Terry; Sibbitt, Bruce

    1978-01-01

    A flat plate radiant energy collector is providing having a transparent cover. The cover has a V-corrugated shape which reduces the amount of energy reflected by the cover away from the flat plate absorber of the collector.

  4. Residue management at Rocky Flats

    SciTech Connect (OSTI)

    Olencz, J.

    1995-12-31

    Past plutonium production and manufacturing operations conducted at the Rocky Flats Environmental Technology Site (RFETS) produced a variety of plutonium-contaminated by-product materials. Residues are a category of these materials and were categorized as {open_quotes}materials in-process{close_quotes} to be recovered due to their inherent plutonium concentrations. In 1989 all RFETS plutonium production and manufacturing operations were curtailed. This report describes the management of plutonium bearing liquid and solid wastes.

  5. Flat space physics from holography

    SciTech Connect (OSTI)

    Bousso, Raphael

    2004-02-06

    We point out that aspects of quantum mechanics can be derived from the holographic principle, using only a perturbative limit of classical general relativity. In flat space, the covariant entropy bound reduces to the Bekenstein bound. The latter does not contain Newton's constant and cannot operate via gravitational backreaction. Instead, it is protected by--and in this sense, predicts--the Heisenberg uncertainty principle.

  6. Method of fabricating a solar absorber panel

    SciTech Connect (OSTI)

    Severson, A.M.

    1982-04-13

    A low-cost method of fabricating a solar absorber panel for use with a flat plate solar collector system is disclosed in which a plurality of formed elongated substantially u-shaped members are fixed in a predetermined configuration to the reverse side of a single sheet absorber member forming therewith hollow fluid passages or ducts. The fluid duct members are provided with a series of tabs which alternately protrude through spaced slits in the absorber panel such that when the tabs are folded over, a tight interlocking construction is produced. The ends of the single sheet absorber may then be folded to form inlet and outlet manifolds connecting the ends of the series of spaced ducts including closing end tabs or the manifolds may be fabricated of u-shaped tabbed members in the manner of the connecting passages. After the mechanical assembly, the entire unit is sealed as by pumping liquid solder under pressure through the unit. This not only seals the system but also provides a corrosion-resistant coating of solder over all internal parts.

  7. Independent Oversight Special Review, Rocky Flats Closure Project...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Rocky Flats Closure Project Site - April 2001 Independent Oversight Special Review, Rocky Flats Closure Project Site - April 2001 April 2001 Special Review of the Rocky Flats...

  8. ROCKY FLATS CLOSURE PROJECT EM, AUG 2006 | Department of Energy

    Energy Savers [EERE]

    AUG 2006 ROCKY FLATS CLOSURE PROJECT EM, AUG 2006 PDF icon Rocky Flats Closure Project-Lessons Learned-August 2006.pdf More Documents & Publications Rocky Flats Overview...

  9. Black optic display

    DOE Patents [OSTI]

    Veligdan, James T.

    1997-01-01

    An optical display includes a plurality of stacked optical waveguides having first and second opposite ends collectively defining an image input face and an image screen, respectively, with the screen being oblique to the input face. Each of the waveguides includes a transparent core bound by a cladding layer having a lower index of refraction for effecting internal reflection of image light transmitted into the input face to project an image on the screen, with each of the cladding layers including a cladding cap integrally joined thereto at the waveguide second ends. Each of the cores is beveled at the waveguide second end so that the cladding cap is viewable through the transparent core. Each of the cladding caps is black for absorbing external ambient light incident upon the screen for improving contrast of the image projected internally on the screen.

  10. Concentrating photovoltaic solar panel

    DOE Patents [OSTI]

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  11. Photovoltaic panel clamp

    DOE Patents [OSTI]

    Mittan, Margaret Birmingham; Miros, Robert H. J.; Brown, Malcolm P.; Stancel, Robert

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  12. Photovoltaic panel clamp

    DOE Patents [OSTI]

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  13. Thermal insulations using vacuum panels

    DOE Patents [OSTI]

    Glicksman, Leon R.; Burke, Melissa S.

    1991-07-16

    Thermal insulation vacuum panels are formed of an inner core of compressed low thermal conductivity powders enclosed by a ceramic/glass envelope evaluated to a low pressure.

  14. WIPP_Panel_7_Approved

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Panel 7 Certified and Ready for Waste Disposal CARLSBAD, N.M., August 1, 2013 - In mid-July 2013, the New Mexico Environment Department (NMED) approved the use of Panel 7 for disposal of defense- related transuranic (TRU) waste at the Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP). Approval by NMED for each underground waste disposal panel prior to use is required under the WIPP Hazardous Waste Facility Permit (Permit). A panel consists of seven waste disposal rooms and each room

  15. Signal Processing, Analysis, & Display

    Energy Science and Technology Software Center (OSTI)

    1986-06-01

    SIG is a general-purpose signal processing, analysis, and display program. Its main purpose is to perform manipulations on time- and frequency-domain signals. However, it has been designed to ultimately accommodate other representations for data such as multiplexed signals and complex matrices. Two user interfaces are provided in SIG - a menu mode for the unfamiliar user and a command mode for more experienced users. In both modes errors are detected as early as possible andmoreare indicated by friendly, meaningful messages. An on-line HELP package is also included. A variety of operations can be performed on time- and frequency-domain signals including operations on the samples of a signal, operations on the entire signal, and operations on two or more signals. Signal processing operations that can be performed are digital filtering (median, Bessel, Butterworth, and Chebychev), ensemble average, resample, auto and cross spectral density, transfer function and impulse response, trend removal, convolution, Fourier transform and inverse window functions (Hamming, Kaiser-Bessel), simulation (ramp, sine, pulsetrain, random), and read/write signals. User definable signal processing algorithms are also featured. SIG has many options including multiple commands per line, command files with arguments,commenting lines, defining commands, and automatic execution for each item in a repeat sequence. Graphical operations on signals and spectra include: x-y plots of time signals; real, imaginary, magnitude, and phase plots of spectra; scaling of spectra for continuous or discrete domain; cursor zoom; families of curves; and multiple viewports.less

  16. Closing Rocky Flats by 2006

    SciTech Connect (OSTI)

    Tuor, N. R.; Schubert, A. L.

    2002-02-26

    Safely accelerating the closure of Rocky Flats to 2006 is a goal shared by many: the State of Colorado, the communities surrounding the site, the U.S. Congress, the Department of Energy, Kaiser-Hill and its team of subcontractors, the site's employees, and taxpayers across the country. On June 30, 2000, Kaiser-Hill (KH) submitted to the Department of Energy (DOE), KH's plan to achieve closure of Rocky Flats by December 15, 2006, for a remaining cost of $3.96 billion (February 1, 2000, to December 15, 2006). The Closure Project Baseline (CPB) is the detailed project plan for accomplishing this ambitious closure goal. This paper will provide a status report on the progress being made toward the closure goal. This paper will: provide a summary of the closure contract completion criteria; give the current cost and schedule variance of the project and the status of key activities; detail important accomplishments of the past year; and discuss the challenges ahead.

  17. Solar heating panel arrangement

    SciTech Connect (OSTI)

    Chang, M.K.

    1983-07-12

    A solar heating panel arrangement and method are disclosed wherein a plurality of spherical lenses transmit and focus solar radiation onto the upper surface of a fluid passage for various relative positions of the sun. The upper surface of the passage is in heat transfer proximity to the fluid therein, causing solar radiation focused thereon to be transferred to the fluid in the form of heat. Solar radiation not directly incident on the lenses may be reflected onto them to increase the amount of solar energy available for transfer to the fluid. A supplementary insulating flow of fluid may also be provided above the passage to absorb heat passing upwardly therefrom and retain the heat within the system.

  18. Signal Processing, Analysis, & Display

    Energy Science and Technology Software Center (OSTI)

    1986-06-01

    SIG is a general-purpose signal processing, analysis, and display program. Its main purpose is to perform manipulations on time- and frequency-domain signals. However, it has been designed to ultimately accommodate other representations for data such as multiplexed signals and complex matrices. Two user interfaces are provided in SIG - a menu mode for the unfamiliar user and a command mode for more experienced users. In both modes errors are detected as early as possible andmore » are indicated by friendly, meaningful messages. An on-line HELP package is also included. A variety of operations can be performed on time- and frequency-domain signals including operations on the samples of a signal, operations on the entire signal, and operations on two or more signals. Signal processing operations that can be performed are digital filtering (median, Bessel, Butterworth, and Chebychev), ensemble average, resample, auto and cross spectral density, transfer function and impulse response, trend removal, convolution, Fourier transform and inverse window functions (Hamming, Kaiser-Bessel), simulation (ramp, sine, pulsetrain, random), and read/write signals. User definable signal processing algorithms are also featured. SIG has many options including multiple commands per line, command files with arguments,commenting lines, defining commands, and automatic execution for each item in a repeat sequence. Graphical operations on signals and spectra include: x-y plots of time signals; real, imaginary, magnitude, and phase plots of spectra; scaling of spectra for continuous or discrete domain; cursor zoom; families of curves; and multiple viewports.« less

  19. Built-in solar panel

    SciTech Connect (OSTI)

    Aloi, M.J.; Hancock, K.J.

    1981-06-16

    Disclosed herein is a solar panel assembly and method for fabrication of same. A portion of the rafters and roof sheeting is cut away to provide an orifice of suitable dimension within which a solar panel frame is to be disposed. A step portion is provided on an upper inner periphery thereof, and a frame lower portion is disposed upon the step. Conduits extend through the solar panel frame at upper and lower portions thereof in a substantially horizontal direction. These conduits are interconnected with a tubed collector plate. An insulative layer is provided underneath this tubed plate. A transparent panel is placed on top of the frame lower portion, and overlying the panel with a frame upper portion which connects the solar panel frame and the frame lower portion by suitable fasteners. Appropriate weather stripping is deployed between the frame upper portion and the solar panel frame, and the open area that exists between the solar panel frame and the roof is provided with a flashing so as to complete the sealing arrangement.

  20. Built-in solar panel

    SciTech Connect (OSTI)

    Aloi, M.J.; Hancock, K.J. II

    1983-07-12

    Disclosed herein is a solar panel assembly and method for fabrication of same including cutting away a portion of the rafters and roof sheeting to provide an orifice of suitable dimension within which a solar panel frame is to be disposed, providing a step portion on an upper inner periphery thereof, disposing a frame lower portion upon the step, installing conduits extending through the solar panel frame at upper and lower portions thereof in a substantially horizontal direction, interconnecting these conduits with a tubed collector plate, providing an insulative layer underneath this tubed plate, placing a transparent panel on top of the frame lower portion, and overlying the panel with a frame upper portion which connects the solar panel frame and the frame lower portion by suitable fasteners. Appropriate weather stripping is deployed between the frame upper portion and the solar panel frame, and the open area that exists between the solar panel frame and the roof is provided with a flashing so as to complete the sealing arrangement.

  1. Independent Oversight Review, Rocky Flats Environmental Technology...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Review of the Rocky Flats Environmental Technology Site Transportation Emergency Management Program This report provides the results of an independent review of the Transportation ...

  2. Stable Flats LLC | Open Energy Information

    Open Energy Info (EERE)

    to build the first multi-family LEED (Leadership in Energy & Environmental Design) Gold certified structure in the country. References: Stable Flats LLC1 This article is a...

  3. LG Display | Open Energy Information

    Open Energy Info (EERE)

    Zip: 150-721 Product: Korea Republic-based manufacturer and merchant supplier of thin-film transistor liquid crystal displays. Manufacturer of thin-film PV. Coordinates:...

  4. MODIFICATIONS TO THE WIPP PANEL CLOSURE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... in Panel 4 than in Panel 3. Please compare the waste inventories in Panels 3 and 4 ... to WIPP." This category consists of high-wattage (i.e., high decay heat) payload ...

  5. Rocky Flats Neutron Detector Testing at Valduc, France

    SciTech Connect (OSTI)

    Kim, S S; Dulik, G M

    2011-01-03

    Recent program requirements of the US Department of Energy/NNSA have led to a need for a criticality accident alarm system to be installed at a newly activated facility. The Criticality Safety Group of the Lawrence Livermore National Laboratory (LLNL) was able to recover and store for possible future use approximately 200 neutron criticality detectors and 20 master alarm panels from the former Rocky Flats Plant in Golden, Colorado when the plant was closed. The Criticality Safety Group participated in a facility analysis and evaluation, the engineering design and review process, as well as the refurbishment, testing, and recalibration of the Rocky Flats criticality alarm system equipment to be used in the new facility. In order to demonstrate the functionality and survivability of the neutron detectors to the effects of an actual criticality accident, neutron detector testing was performed at the French CEA Valduc SILENE reactor from October 7 to October 19, 2010. The neutron detectors were exposed to three criticality events or pulses generated by the SILENE reactor. The first excursion was performed with a bare or unshielded reactor, and the second excursion was made with a lead shielded/reflected reactor, and the third excursion with a polyethylene reflected core. These tests of the Rocky Flats neutron detectors were performed as a part of the 2010 Criticality Accident Alarm System Benchmark Measurements at the SILENE Reactor. The principal investigators for this series of experiments were Thomas M. Miller and John C. Wagner of the Oak Ridge National Laboratory, with Nicolas Authier and Nathalie Baclet of CEA Valduc. Several other organizations were also represented, including the Y-12 National Security Complex, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, CEA Saclay, and Babcock International Group.

  6. Panelized wall system with foam core insulation

    SciTech Connect (OSTI)

    Kosny, Jan; Gaskin, Sally

    2009-10-20

    A wall system includes a plurality of wall members, the wall members having a first metal panel, a second metal panel, and an insulating core between the first panel and the second panel. At least one of the first panel and the second panel include ridge portions. The insulating core can be a foam, such as a polyurethane foam. The foam can include at least one opacifier to improve the k-factor of the foam.

  7. Designation Memo: Federal Technical Capability Panel Chairperson...

    Energy Savers [EERE]

    Federal Technical Capability Panel Chairperson Designation Memo: Federal Technical Capability Panel Chairperson May 4, 2007, the Deputy Secretary memorandum designating Karen ...

  8. Solar panel and method of manufacturing a solar panel

    SciTech Connect (OSTI)

    Duchateau, J.; Nicolas, M.

    1982-05-25

    A solar panel comprising at least one solar energy transducer laminated between a transparent vitreous sheet and a second sheet in which the transducer is imbedded in a layer of transparent polymeric material which bonds the sheets together. The polymeric material comprises an acrylic compound. A method of making the aforesaid solar panel in which the acrylic compound is allowed to set in situ is described.

  9. DOE - NNSA/NFO -- Exhibits and Displays

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Exhibits and Displays NNSANFO Language Options U.S. DOENNSA - Nevada Field Office Exhibits and Displays Educational exhibits and displays are available for loan to libraries, ...

  10. Rocky Flats beryllium health surveillance

    SciTech Connect (OSTI)

    Stange, A.W.; Furman, F.J.; Hilmas, D.E.

    1996-10-01

    The Rocky Flats Beryllium Health Surveillance Program (BHSP), initiated in June 1991, was designed to provide medical surveillance for current and former employees exposed to beryllium. The BHSP identifies individuals who have developed beryllium sensitivity using the beryllium lymphocyte proliferation test (BeLPT). A detailed medical evaluation to determine the prevalence of chronic beryllium disease (CBD) is offered to individuals identified as beryllium sensitized or to those who have chest X-ray changes suggestive of CBD. The BHSP has identified 27 cases of CBD and another 74 cases of beryllium sensitization out of 4268 individuals tested. The distribution of BeLPT values for normal, sensitized, and CBD-identified individuals is described. Based on the information collected during the first 3 1/3 years of the BHSP, the BeLPT is the most effective means for the early identification of beryllium-sensitized individuals and to identify individuals who may have CBD. The need for BeLPT retesting is demonstrated through the identification of beryllium sensitization in individuals who previously tested normal. Posterior/anterior chest X-rays were not effective in the identification of CBD. 12 refs., 8 tabs.

  11. Blue Ribbon Panel Recommendations Report

    Broader source: Energy.gov [DOE]

    The Department of Energy's Geothermal Technologies Office (formerly Geothermal Technologies Program) assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a...

  12. Exascale Workshop Panel Report Meeting

    SciTech Connect (OSTI)

    Khaleel, Mohammad A.

    2010-07-01

    The Exascale Review Panel consists of 12 scientists and engineers with experience in various aspects of high-performance computing and its application, development, and management. The Panel hear presentations by several representatives of the workshops and town meetings convened over the past few years to examine the need for exascale computation capability and the justification for a U.S. Department of Energy (DOE) program to develop such capability. This report summarizes information provided by the presenters and substantial written reports to the Panel in advance of the meeting in Washington D.C. on January 19-20, 2010. The report also summarizes the Panel's conclusions with regard to the justification of a DOE-led exascale initiative.

  13. Cone-beam breast computed tomography with a displaced flat panel detector array

    SciTech Connect (OSTI)

    Mettivier, Giovanni; Russo, Paolo; Lanconelli, Nico; Meo, Sergio Lo

    2012-05-15

    Purpose: In cone-beam computed tomography (CBCT), and in particular in cone-beam breast computed tomography (CBBCT), an important issue is the reduction of the image artifacts produced by photon scatter and the reduction of patient dose. In this work, the authors propose to apply the detector displacement technique (also known as asymmetric detector or ''extended view'' geometry) to approach this goal. Potentially, this type of geometry, and the accompanying use of a beam collimator to mask the unirradiated half-object in each projection, permits some reduction of radiation dose with respect to conventional CBBCT and a sizeable reduction of the overall amount of scatter in the object, for a fixed contrast-to-noise ratio (CNR). Methods: The authors consider a scan configuration in which the projection data are acquired from an asymmetrically positioned detector that covers only one half of the scan field of view. Monte Carlo simulations and measurements, with their CBBCT laboratory scanner, were performed using PMMA phantoms of cylindrical (70-mm diameter) and hemiellipsoidal (140-mm diameter) shape simulating the average pendant breast, at 80 kVp. Image quality was evaluated in terms of contrast, noise, CNR, contrast-to-noise ratio per unit of dose (CNRD), and spatial resolution as width of line spread function for high contrast details. Results: Reconstructed images with the asymmetric detector technique deviate less than 1% from reconstruction with a conventional symmetric detector (detector view) and indicate a reduction of the cupping artifact in CT slices. The maximum scatter-to-primary ratio at the center of the phantom decreases by about 50% for both small and large diameter phantoms (e.g., from 0.75 in detector view to 0.40 in extended view geometry at the central axis of the 140-mm diameter PMMA phantom). Less cupping produces an increase of the CT number accuracy and an improved image detail contrast, but the associated increase of noise observed may produce a decrease of detail CNR. By simulating the energy deposited inside the phantoms, the authors evaluated a maximum 50% reduction of the absorbed dose at the expense of a decrease of CNR, for the half beam irradiation of the object performed with the displaced detector technique with respect to full beam irradiation. The decrease in CNR, and in absorbed dose as well, translates into a detail CNRD showing values comparable to or higher than the ones obtained for a conventional symmetric detector technique, attributed to the effect of decreased scatter in particular at the axis of the irradiated object. An estimate is provided (about 12%) for the average dose reduction possible in CBBCT at constant CNR for the average uncompressed breast (14 cm diameter, 50% glandularity), in case of minimum image overlapping in extended view. Conclusions: Simulations and experiments show that CBCT reconstructions with the displaced detector technique and with a half beam collimator are less affected by scatter artifacts, which could lead to some decrease of the radiation dose to the irradiated object with respect to a conventional reconstruction. This dose reduction is associated with increase of noise, decrease of CNR, but equal or improved CNRD values. The use of a small area detector would allow also to reduce the apparatus cost and to improve the data transfer speed with a corresponding increment of frame rate.

  14. Inside the White House: Solar Panels | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Inside the White House: Solar Panels Inside the White House: Solar Panels

  15. Rocky Flats ash test procedure (sludge stabilization)

    SciTech Connect (OSTI)

    Winstead, M.L.

    1995-09-14

    Rocky Flats Ash items have been identified as the next set of materials to be stabilized. This test is being run to determine charge sizes and soak times to completely stabilize the Rocky Flats Ash items. The information gathered will be used to generate the heating rampup cycle for stabilization. This test will also gain information on the effects of the glovebox atmosphere (moisture) on the stabilized material. This document provides instructions for testing Rocky Flats Ash in the HC-21C muffle furnace process.

  16. Windy Flats(3Q09 portion) | Open Energy Information

    Open Energy Info (EERE)

    Flats(3Q09 portion) Jump to: navigation, search Name Windy Flats(3Q09 portion) Facility Windy Flats(3Q09 portion) Sector Wind energy Facility Type Commercial Scale Wind Facility...

  17. ROCKY FLATS CLOSURE PROJECT EM, AUG 2006 | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ROCKY FLATS CLOSURE PROJECT EM, AUG 2006 ROCKY FLATS CLOSURE PROJECT EM, AUG 2006 PDF icon Rocky Flats Closure Project-Lessons Learned-August 2006.pdf More Documents & Publications...

  18. Wood panel earth shelter construction

    SciTech Connect (OSTI)

    Berg, J.R.; Loveless, J.G.; Senkow, W.

    1986-05-27

    An earth sheltered building is described including an arch structure, the structure including footings, a floor extending between the footings and arch means extending between the footings and having a base having lower ends on the footings for defining an enclosure which is covered with earth and open at opposite ends. The arch structure consists of: joined, curved wooden panel sections arranged in tandem in adjacent rows with more than two panel sections in a row, each of the sections including circumferentially extending wooden side members; wooden sheathing sections overlying the top skins of panel sections, the sheathing including a plurality of plywood sheets lapped over the joints between the panel sections and treated with a preservative; an adhesive joining the panel sections together within each row and to adjacent rows; waterproofing means on the sheathing for waterproofing the exterior surface of the arch means; connecting means engaging the base of the arch means at the footings and within the floor for tying the base together at its lower ends; and end walls and fastener means for joining the end walls to lateral edges of the arch means, the end walls dimensioned to extend above the arch means to retain earth placed on the arch means.

  19. Landfill Cover Revegetation at the Rocky Flats Environmental Technology

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Site | Department of Energy Landfill Cover Revegetation at the Rocky Flats Environmental Technology Site Landfill Cover Revegetation at the Rocky Flats Environmental Technology Site Landfill Cover Revegetation at the Rocky Flats Environmental Technology Site Landfill Cover Revegetation at the Rocky Flats Environmental Technology Site (507.34 KB) More Documents & Publications Revegetation of the Rocky Flats Site Smooth Brome Monitoring at Rocky Flats-2005 Results EIS-0285-SA-134:

  20. Microsoft Word - TurtleFlats_CX

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Turtle Flats Property Acquisition Funding Fish and Wildlife Project No.: 2011-003-00, ... This is part of BPA's ongoing efforts to mitigate for the impacts to fish and wildlife ...

  1. Rocky Flats Ash test procedure (sludge stabilization)

    SciTech Connect (OSTI)

    Funston, G.A.

    1995-06-14

    Rocky Flats Ash items have been identified as the next set of materials to be stabilized. This test is being run to determine charge sizes and soak times to completely stabilize the Rocky Flats Ash items. The information gathered will be used to generate the heating rampup cycle for stabilization. The test will provide information to determine charge sizes, soak times and mesh screen sizes (if available at time of test) for stabilization of Rocky Flats Ash items to be processed in the HC-21C Muffle Furnace Process. Once the charge size and soak times have been established, a program for the temperature controller of the HC-21C Muffle Furnace process will be generated for processing Rocky Flats Ash.

  2. Rocky Flats resumes shipments to WIPP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Rocky Flats Resumes Shipments to WIPP CARLSBAD, N.M., March 11, 2000 - The U.S. Department of Energy (DOE) has resumed transuranic radioactive waste shipments from DOE's Rocky Flats Environmental Technology Site (RFETS) to the Waste Isolation Pilot Plant (WIPP). A shipment consisting of 28 drums of transuranic waste today arrived safely at WIPP at 5:07 p.m. (Mountain Standard Time). The truck, carrying two TRUPACT-II (Transuranic Packaging Transporter Model II) shipping containers, departed

  3. Rocky Flats Environmental Technology Site Archived Soil & Groundwater...

    Office of Environmental Management (EM)

    Rocky Flats Environmental Technology Site Archived Soil & Groundwater Master Reports Rocky Flats Environmental Technology Site Archived Soil & Groundwater Master Reports Rocky ...

  4. Preliminary Notice of Violation , Rocky Flats Environmental Technology...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Violation , Rocky Flats Environmental Technology Site - EA-96-05 Preliminary Notice of Violation , Rocky Flats Environmental Technology Site - EA-96-05 October 7, 1996 Preliminary...

  5. LM Records Handling System (LMRHS01) - Rocky Flats Environmental...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Rocky Flats Environmental Records Database, Office of Legacy Management LM Records Handling System (LMRHS01) - Rocky Flats Environmental Records Database, Office of Legacy ...

  6. Procedure for measuring the solar reflectance of flat or curved...

    Office of Scientific and Technical Information (OSTI)

    Procedure for measuring the solar reflectance of flat or curved roofing assemblies Citation Details In-Document Search Title: Procedure for measuring the solar reflectance of flat ...

  7. DOE - Office of Legacy Management -- Rocky Flats Archive

    Office of Legacy Management (LM)

    ... Memorandum Regarding Instrumentation and Monitoring at the Rocky Flats OLF Appendix F Solar-Powered Air Stripping at the Rocky Flats Site, Colorado Appendix G RFLMA Contact ...

  8. Rocky Flats Site Expands Solar Power for Treating Groundwater...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Rocky Flats Site Expands Solar Power for Treating Groundwater Rocky Flats Site Expands Solar Power for Treating Groundwater April 17, 2013 - 1:26pm Addthis Subcontractor personnel ...

  9. Solar panel truss mounting systems and methods

    DOE Patents [OSTI]

    Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

    2016-06-28

    An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

  10. Solar panel truss mounting systems and methods

    DOE Patents [OSTI]

    Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

    2015-10-20

    An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

  11. Design of a photovoltaic central power station: flat-plate array

    SciTech Connect (OSTI)

    Not Available

    1984-02-01

    A design for a photovoltaic central power station using fixed flat-panel arrays has been developed. The 100 MW plant is assumed to be located adjacent to the Saguaro Power Station of Arizona Public Service. The design assumes high-efficiency photovoltaic modules using dendritic web cells. The modules are arranged in 5 MW subfields, each with its own power conditioning unit. The photovoltaic output is connected to the existing 115 kV utility switchyard. The site specific design allows detailed cost estimates for engineering, site preparation, and installation. Collector and power conditioning costs have been treated parametrically.

  12. Solar collector panel and method

    SciTech Connect (OSTI)

    King, W. S.

    1985-04-23

    A solar collector panel having a solar energy collector plate and means for flowing a fluid along one side of the plate in a perpendicular serpentine path so that the fluid is repetitively moved toward and away from the plate as it moves along the plate.

  13. Peg supported thermal insulation panel

    DOE Patents [OSTI]

    Nowobilski, J.J.; Owens, W.J.

    1985-04-30

    A thermal insulation panel which is lightweight, load bearing, accommodates thermal stress, and has excellent high temperature insulation capability comprises high performance insulation between thin metal walls supported by high density, high strength glass pegs made in compliance with specified conditions of time, temperature and pressure. 2 figs.

  14. Peg supported thermal insulation panel

    DOE Patents [OSTI]

    Nowobilski, Jeffert J.; Owens, William J.

    1985-01-01

    A thermal insulation panel which is lightweight, load bearing, accommodates thermal stress, and has excellent high temperature insulation capability comprising high performance insulation between thin metal walls supported by high density, high strength glass pegs made in compliance with specified conditions of time, temperature and pressure.

  15. Rocky Flats Compliance Program; Technology summary

    SciTech Connect (OSTI)

    1994-02-01

    The Department of Energy (DOE) established the Office of Technology Development (EM-50) (OTD) as an element of Environmental Restoration and Waste Management (EM) in November 1989. The primary objective of the Office of Technology Development, Rocky Flats Compliance Program (RFCP), is to develop altemative treatment technologies for mixed low-level waste (wastes containing both hazardous and radioactive components) to use in bringing the Rocky Flats Plant (RFP) into compliance with Federal and state regulations and agreements. Approximately 48,000 cubic feet of untreated low-level mixed waste, for which treatment has not been specified, are stored at the RFP. The cleanup of the Rocky Flats site is driven by agreements between DOE, the Environmental Protection Agency (EPA), and the Colorado Department of Health (CDH). Under these agreements, a Comprehensive Treatment and Management Plan (CTMP) was drafted to outline the mechanisms by which RFP will achieve compliance with the regulations and agreements. This document describes DOE`s strategy to treat low-level mixed waste to meet Land Disposal Restrictions and sets specific milestones related to the regulatory aspects of technology development. These milestones detail schedules for the development of technologies to treat all of the mixed wastes at the RFP. Under the Federal Facilities Compliance Act (FFCA), the CTMP has been incorporated into Rocky Flats Plant Conceptual Site Treatment Plan (CSTP). The CSTP will become the Rocky Flats Plant site Treatment Plan in 1995 and will supersede the CTMP.

  16. MicroEmissive Displays | Open Energy Information

    Open Energy Info (EERE)

    Edinburgh, United Kingdom Zip: EH9 3JF Product: MicroEmissive Displays makes P-OLED (polymer light emitting diode) displays. Specific interests are head mounted displays and...

  17. Seismic Lessons-Learned Panel Meetings

    Broader source: Energy.gov [DOE]

    The Chief of Nuclear Security (CNS) maintains a panel of experts known as the Seismic Lessons-Learned Panel, which meets periodically to discuss seismic issues impacting DOE facilities.

  18. Geothermal Technologies Program Blue Ribbon Panel Recommendations

    Office of Energy Efficiency and Renewable Energy (EERE)

    This report describes the recommendations of the Geothermal Blue Ribbon Panel, a panel of geothermal experts assembled in March 2011 for a discussion on the future of geothermal energy in the U.S.

  19. Proposal Review Panel | Stanford Synchrotron Radiation Lightsource

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Proposal Review Panel Submitting a proposal is the first step to access beam time at SSRL. Proposals are peer reviewed and rated by the SSRL Proposal Review Panel (PRP) on a scale ...

  20. Advisory Panels | Stanford Synchrotron Radiation Lightsource

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    SAC Website SSRL Proposal Review Panel (PRP) Access to SSRL beam lines is granted through proposals that are peer-reviewed and rated by the SSRL Proposal Review Panel (PRP). The ...

  1. Universal Display Corp | Open Energy Information

    Open Energy Info (EERE)

    Jump to: navigation, search Name: Universal Display Corp. Place: New Jersey Product: OLED (Organic Light Emitting Device) Developer References: Universal Display Corp.1 This...

  2. Solid waste recycling programs at Rocky Flats

    SciTech Connect (OSTI)

    Millette, R.L.; Blackman, T.E.; Shepard, M.D.

    1994-12-31

    The Rocky Flats (RFP) recycling programs for solid waste materials have been in place for over ten years. Within the last three years, the programs were centralized under the direction of the Rocky Flats Waste Minimization department, with the assistance of various plant organizations (e.g., Trucking, Building Services, Regulated Waste Operations, property Utilization and Disposal and Security). Waste Minimization designs collection and transportation systems for recyclable materials and evaluates recycling markets for opportunities to add new commodities to the existing programs. The Waste Minimization department also promotes employee participation in the Rocky Flats Recycling Programs, and collects all recycling data for publication. A description of the program status as of January 1994 is given.

  3. Total System Performance Assessment Peer Review Panel

    Broader source: Energy.gov [DOE]

    Total System Performance Assessment (TSPA) Peer Review Panel for predicting the performance of a repository at Yucca Mountain.

  4. Chemical tracking at the Rocky Flats Plant

    SciTech Connect (OSTI)

    Costain, D.B.

    1994-04-01

    EG&G Rocky Flats, Inc., has developed a chemical tracking system to support compliance with the Emergency Planning and community Right-to-Know Act (EPCRA) at the Rocky Flats Plant. This system, referred to as the EPCRA Chemical Control system (ECCS), uses bar code technology to uniquely identify and track the receipt, distribution, and use of chemicals. Chemical inventories are conducted using hand-held electronic scanners to update a site wide chemical database on a VAX 6000 computer. Information from the ECCS supports preparation of the EPCRA Tier II and Form R reports on chemical storage and use.

  5. Issues evaluation process at Rocky Flats Plant

    SciTech Connect (OSTI)

    Smith, L.C.

    1992-04-16

    This report describes the issues evaluation process for Rocky Flats Plant as established in July 1990. The issues evaluation process was initiated February 27, 1990 with a Charter and Process Overview for short-term implementation. The purpose of the process was to determine the projects required for completion before the Phased Resumption of Plutonium Operations. To determine which projects were required, the issues evaluation process and emphasized risk mitigation, based on a ranking system. The purpose of this report is to document the early design of the issues evaluation process to record the methodologies used that continue as the basis for the ongoing Issues Management Program at Rocky Flats Plant.

  6. Panel 4 - applications to transportation

    SciTech Connect (OSTI)

    Nichols, F.; Au, J.; Bhattacharya, R.; Bhushan, B.; Blunier, D.; Boardman, B.; Brombolich, L.; Davidson, J.; Graham, M.; Hakim, N.; Harris, K.; Hay, R.; Herk, L.; Hojnacki, H.; Rourk, D.; Kamo, R.; Nieman, B.; O`Neill, D.; Peterson, M.B.; Pfaffenberger, G.; Pryor, R.W.; Russell, J.; Syniuta, W.; Tamor, M.; Vojnovich, T.; Yarbrough, W.; Yust, C.S.

    1993-01-01

    The aim of this group was to compile a listing of current and anticipated future problem areas in the transportation industry where the properties of diamond and DLC films make them especially attractive and where the panel could strongly endorse the establishment of DOE/Transportation Industry cooperative research efforts. This section identifies the problem areas for possible applications of diamond/DLC technology and presents indications of current approaches to these problems.

  7. SGIP Smart Grid Interoperabilty Panel

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    SGIP Smart Grid Interoperability Panel Building2Grid Integration Dave Hardin David Holmberg ∗ The SGIP was explicitly established to support NIST in fulfilling its responsibilities pursuant to the Energy Independence and Security Act of 2007 ("EISA"). SGIP 1.0: NIST-funded, SGIP 2.0: Member-funded ∗ SGIP's mission is to provide a framework for coordinating all Smart Grid stakeholders in an effort to accelerate standards harmonization and advance the Interoperability of Smart Grid

  8. WM2015 Conference Panel Report

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    016: Lessons Learned and Return to Operations Following the 2014 Operational Incidents at WIPP Session Co-Chairs: Joe Franco, US DOE, Carlsbad Field Office Robert McQuinn, Nuclear Waste Partnership, LLC Panel Reporter: Roger Nelson, US DOE, Carlsbad Field Office Panelists:  Sean Dunagan, Recovery Manager, Carlsbad Field Office, US DOE  Mark Senderling, Headquarters Recovery Manager, US DOE - EM  Jim Blankenhorn, Recovery Manager, Nuclear Waste Partnership  J.R. Stroble, TRU Sites and

  9. Neal Lane: Science in a Flat World

    SciTech Connect (OSTI)

    Neal Lane

    2006-09-12

    Lane discusses the changes that have taken place in the world since World War II that have made it "flatter," referring to Thomas L. Friedman's book, The World is Flat. Friedman's main premise is that inexpensive telecommunications is bringing about unhampered international competition, the demise of economic stability, and a trend toward outsourcing services, such as computer programming, engineering and science research.

  10. Neal Lane: Science in a Flat World

    ScienceCinema (OSTI)

    Neal Lane

    2010-09-01

    Lane discusses the changes that have taken place in the world since World War II that have made it "flatter," referring to Thomas L. Friedman's book, The World is Flat. Friedman's main premise is that inexpensive telecommunications is bringing about unhampered international competition, the demise of economic stability, and a trend toward outsourcing services, such as computer programming, engineering and science research.

  11. Sub-crop geologic map of pre-Tertiary rocks in the Yucca Flat and northern Frenchman Flat areas, Nevada Test Site, southern Nevada

    SciTech Connect (OSTI)

    Cole, J.C.; Harris, A.G.; Wahl, R.R.

    1997-10-02

    This map displays interpreted structural and stratigraphic relations among the Paleozoic and older rocks of the Nevada Test Site region beneath the Miocene volcanic rocks and younger alluvium in the Yucca Flat and northern Frenchman Flat basins. These interpretations are based on a comprehensive examination and review of data for more than 77 drillholes that penetrated part of the pre-Tertiary basement beneath these post-middle Miocene structural basins. Biostratigraphic data from conodont fossils were newly obtained for 31 of these holes, and a thorough review of all prior microfossil paleontologic data is incorporated in the analysis. Subsurface relationships are interpreted in light of a revised regional geologic framework synthesized from detailed geologic mapping in the ranges surrounding Yucca Flat, from comprehensive stratigraphic studies in the region, and from additional detailed field studies on and around the Nevada Test Site. All available data indicate the subsurface geology of Yucca Flat is considerably more complicated than previous interpretations have suggested. The western part of the basin, in particular, is underlain by relics of the eastward-vergent Belted Range thrust system that are folded back toward the west and thrust by local, west-vergent contractional structures of the CP thrust system. Field evidence from the ranges surrounding the north end of Yucca Flat indicate that two significant strike-slip faults track southward beneath the post-middle Miocene basin fill, but their subsurface traces cannot be closely defined from the available evidence. In contrast, the eastern part of the Yucca Flat basin is interpreted to be underlain by a fairly simple north-trending, broad syncline in the pre-Tertiary units. Far fewer data are available for the northern Frenchman Flat basin, but regional analysis indicates the pre-Tertiary structure there should also be relatively simple and not affected by thrusting. This new interpretation has implications

  12. Concentrating Solar Panels: Bringing the Highest Power and Lowest Cost to the Rooftop

    SciTech Connect (OSTI)

    Michael Deck; Rick Russell

    2010-01-05

    Soliant Energy is a venture-capital-backed startup focused on bringing advanced concentrating solar panels to market. Our fundamental innovation is that we are the first company to develop a racking solar concentrator specifically for commercial rooftop applications, resulting in the lowest LCOE for rooftop electricity generation. Today, the commercial rooftop segment is the largest and fastest-growing market in the solar industry. Our concentrating panels can make a major contribution to the SAI's objectives: reducing the cost of solar electricity and rapidly deploying capacity. Our commercialization focus was re-shaped in 2009, shifting from an emphasis solely on panel efficiency to LCOE. Since the inception of the SAI program, LCOE has become the de facto standard for comparing commercial photovoltaic systems. While estimation and prediction models still differ, the emergence of performance-based incentive (PBI) and feed-in tariff (FIT) systems, as well as power purchase agreement (PPA) financing structures make LCOE the natural metric for photovoltaic systems. Soliant Energy has designed and demonstrated lower-cost, higher-power solar panels that consists of 6 (500X) PV module assemblies utilizing multi-junction cells and an integrated two-axis tracker. In addition, we have designed and demonstrated a prototype 1000X panel assembly with 8. Cost reductions relative to conventional flat panel PV systems were realized by (1) reducing the amount of costly semiconductor material and (2) developing strategies and processes to reduce the manufacturing costs of the entire system. Performance gains against conventional benchmarks were realized with (1) two-axis tracking and (2) higher-efficiency multi-junction PV cells capable of operating at a solar concentration ratio of 1000X (1000 kW/m2). The program objectives are: (1) Develop a tracking/concentrating solar module that has the same geometric form factor as a conventional flat, roof mounted photovoltaic (PV) panel

  13. Annual collectible energy of a two-axis tracking flat-plate solar collector

    SciTech Connect (OSTI)

    Attalage, R.A.; Reddy, T.A. )

    1992-01-01

    A correlation for annual collectible energy of a two-axis tracking flat-plate solar collector has been developed using simulated results based on typical meteorological year (TMY) data for 26 US locations. A preliminary validation of this correlation has been carried out with data from four Australian locations. With the advent of increasing interest in photovoltaic systems, there are a number of advantages of using a two-axis flat-plate collector. Since the tracking system is generally much cheaper than the collector panel, such a mode permits the incident solar radiation to be collected more efficiently. Incidence angle effects are minimized and, moreover, contrary to concentrating collectors, such a mode enables both the diffuse and beam components of solar radiation to be collected. In tropical locations where the diffuse fraction is generally high, this may be a great advantage. The objective of this study was to develop a correlation for the annual collectible energy of a two-axis tracking flat-plate collector.

  14. Release fractions for Rocky Flats specific accidents

    SciTech Connect (OSTI)

    Weiss, R.C.

    1992-09-01

    As Rocky Flats and other DOE facilities begin the transition process towards decommissioning, the nature of the scenarios to be studied in safety analysis will change. Whereas the previous emphasis in safety accidents related to production, now the emphasis is shifting to accidents related tc decommissioning and waste management. Accident scenarios of concern at Rocky Flats now include situations of a different nature and different scale than are represented by most of the existing experimental accident data. This presentation will discuss approaches@to use for applying the existing body of release fraction data to this new emphasis. Mention will also be made of ongoing efforts to produce new data and improve the understanding of physical mechanisms involved.

  15. Emergent universe in spatially flat cosmological model

    SciTech Connect (OSTI)

    Zhang, Kaituo; Yu, Hongwei; Wu, Puxun E-mail: wpx0227@gmail.com

    2014-01-01

    The scenario of an emergent universe provides a promising resolution to the big bang singularity in universes with positive or negative spatial curvature. It however remains unclear whether the scenario can be successfully implemented in a spatially flat universe which seems to be favored by present cosmological observations. In this paper, we study the stability of Einstein static state solutions in a spatially flat Shtanov-Sahni braneworld scenario. With a negative dark radiation term included and assuming a scalar field as the only matter energy component, we find that the universe can stay at an Einstein static state past eternally and then evolve to an inflation phase naturally as the scalar field climbs up its potential slowly. In addition, we also propose a concrete potential of the scalar field that realizes this scenario.

  16. Towards a flat 45%-efficient concentrator module

    SciTech Connect (OSTI)

    Mohedano, Rubén Hernandez, Maikel; Vilaplana, Juan; Chaves, Julio; Sorgato, S.; Falicoff, Waqidi; Miñano, Juan C.; Benitez, Pablo

    2015-09-28

    The so-called CCS{sup 4}FK is an ultra-flat photovoltaic system of high concentration and high efficiency, with potential to convert, ideally, the equivalent of a 45% of direct solar radiation into electricity by optimizing the usage of sun spectrum and by collecting part of the diffuse radiation, as a flat plate does. LPI has recently finished a design based on this concept and is now developing a prototype based on this technology, thanks to the support of FUNDACION REPSOL-Fondo de Emprendedores, which promotes entrepreneur projects in different areas linked to energy. This works shows some details of the actual design and preliminary potential performance expected, according to accurate spectral simulations.

  17. Final Transuranic Waste Shipment Leaves Rocky Flats | Department...

    Office of Environmental Management (EM)

    Transuranic Waste Shipment Leaves Rocky Flats Final Transuranic Waste Shipment Leaves Rocky Flats April 19, 2005 - 12:23pm Addthis Cleanup Ahead of Schedule, On Track to Save ...

  18. Salt Wells, Eight Mile Flat | Open Energy Information

    Open Energy Info (EERE)

    Eight Mile Flat Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Salt Wells, Eight Mile Flat Abstract Abstract unavailable. Author Nevada Bureau...

  19. SLIDESHOW: Shepherds Flat Wind Farm | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Shepherds Flat Wind Farm SLIDESHOW: Shepherds Flat Wind Farm Addthis 1 of 5 Image: Caithness Energy 2 of 5 Image: Caithness Energy 3 of 5 Image: Caithness Energy 4 of 5 Image: Caithness Energy 5 of 5 Image: Caithness Energy

  20. Vascular Flora of the Rocky Flats Area, Jefferson County, Colorado...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Vascular Flora of the Rocky Flats Area, Jefferson County, Colorado, USA August 2010 Jody K. Nelson PDF icon Vascular Flora of the Rocky Flats Area, Jefferson County, Colorado, USA ...

  1. DOE - Office of Legacy Management -- Rocky Flats Regulatory Documents

    Office of Legacy Management (LM)

    Notification that GS01 is no longer an RFLMA Point of Compliance (POC) Third Five-Year Review Report for the Rocky Flats Site Rocky Flats Legacy Management Agreement Environmental ...

  2. An Alternative High Luminosity LHC with Flat Optics and Long...

    Office of Scientific and Technical Information (OSTI)

    LHC with Flat Optics and Long-Range Beam-Beam Compensation Citation Details In-Document Search Title: An Alternative High Luminosity LHC with Flat Optics and Long-Range ...

  3. An Alternative High Luminosity LHC with Flat Optics and Long...

    Office of Scientific and Technical Information (OSTI)

    with Flat Optics and Long-Range Beam-Beam Compensation Citation Details In-Document Search Title: An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam ...

  4. Immobilization of Rocky Flats graphite fines residues

    SciTech Connect (OSTI)

    Rudisill, T.S.; Marra, J.C.; Peeler, D.K.

    1999-07-01

    The Savannah River Technology Center (SRTC) is developing an immobilization process for graphite fines residues generated during nuclear materials production activities at the Rocky Flats Environmental Technology Site (Rocky Flats). The continued storage of this material has been identified as an item of concern. The residue was generated during the cleaning of graphite casting molds and potentially contains reactive plutonium metal. The average residue composition is 73 wt% graphite, 15 wt% calcium fluoride (CaF{sub 2}), and 12 wt% plutonium oxide (PuO{sub 2}). Approximately 950 kg of this material are currently stored at Rocky Flats. The strategy of the immobilization process is to microencapsulate the residue by mixing with a sodium borosilicate (NBS) glass frit and heating at nominally 700 C. The resulting waste form would be sent to the Waste Isolation Pilot Plant (WIPP) for disposal. Since the PuO{sub 2} concentration in the residue averages 12 wt%, the immobilization process was required to meet the intent of safeguards termination criteria by limiting plutonium recoverability based on a test developed by Rocky Flats. The test required a plutonium recovery of less than 4 g/kg of waste form when a sample was leached using a nitric acid/CaF{sub 2} dissolution flowsheet. Immobilization experiments were performed using simulated graphite fines with cerium oxide (CeO{sub 2}) as a surrogate for PuO{sub 2} and with actual graphite fines residues. Small-scale surrogate experiments demonstrated that a 4:1 frit to residue ratio was adequate to prevent recovery of greater than 4 g/kg of cerium from simulated waste forms. Additional experiments investigated the impact of varying concentrations of CaF{sub 2} and the temperature/heating time cycle on the cerium recovery. Optimal processing conditions developed during these experiments were subsequently demonstrated at full-scale with surrogate materials and on a smaller scale using actual graphite fines.

  5. Status Update: Closing Rocky Flats by 2006

    SciTech Connect (OSTI)

    Tuor, N.; Schubert, A.

    2003-02-25

    Safely closing Rocky Flats by December 2006 is a goal shared by many: the State of Colorado, the communities surrounding the site, the U.S. Congress, the Department of Energy (DOE), Kaiser-Hill and its team of subcontractors, the site's employees and taxpayers across the country. This paper will: provide a status of the Closure Project to date; describe important accomplishments of the past year; describe some of the closure-enhancing technologies enabling acceleration; and discuss the remaining challenges ahead.

  6. Microwave solidification development for Rocky Flats waste

    SciTech Connect (OSTI)

    Dixon, D.; Erle, R.; Eschen, V.

    1994-04-01

    The Microwave Engineering Team at the Rocky Flats Plant has developed a production-scale system for the treatment of hazardous, radioactive, and mixed wastes using microwave energy. The system produces a vitreous final form which meets the acceptance criteria for shipment and disposal. The technology also has potential for application on various other waste streams from the public and private sectors. Technology transfer opportunities are being identified and pursued for commercialization of the microwave solidification technology.

  7. Basic TRUEX process for Rocky Flats Plant

    SciTech Connect (OSTI)

    Leonard, R.A.; Chamberlain, D.B.; Dow, J.A.; Farley, S.E.; Nunez, L.; Regalbuto, M.C.; Vandegrift, G.F.

    1994-08-01

    The Generic TRUEX Model was used to develop a TRUEX process flowsheet for recovering the transuranics (Pu, Am) from a nitrate waste stream at Rocky Flats Plant. The process was designed so that it is relatively insensitive to changes in process feed concentrations and flow rates. Related issues are considered, including solvent losses, feed analysis requirements, safety, and interaction with an evaporator system for nitric acid recycle.

  8. DOE - NNSA/NFO -- News & Views Frenchman Flat

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Frenchman Flat Photo - Wooden bleachers at Yucca Flats Between January 27, 1951 and March 25, 1968 fourteen atmospheric and five underground tests were detonated at Frenchman Flat. The 320-square-kilometer (123-square-mile) dry lake bed is one of three major closed desert valley basins at the Nevada Test Site, the others being Yucca and Jackass Flats. From 1953 to 1958, reinforced structures were exposed to of nuclear blasts and accompanying overpressures. Among the items exposed to the blasts

  9. LM Records Handling System (LMRHS01) - Rocky Flats Environmental Records

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Database, Office of Legacy Management | Department of Energy Rocky Flats Environmental Records Database, Office of Legacy Management LM Records Handling System (LMRHS01) - Rocky Flats Environmental Records Database, Office of Legacy Management LM Records Handling System (LMRHS01) - Rocky Flats Environmental Records Database, Office of Legacy Management LM Records Handling System (LMRHS01) - Rocky Flats Environmental Records Database, Office of Legacy Management (470.9 KB) More Documents

  10. Independent Oversight Review, Rocky Flats Environmental Technology Site -

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    March 2000 | Department of Energy Rocky Flats Environmental Technology Site - March 2000 Independent Oversight Review, Rocky Flats Environmental Technology Site - March 2000 March 2000 Review of the Rocky Flats Environmental Technology Site Transportation Emergency Management Program This report provides the results of an independent review of the Transportation Emergency Management Program at the Department of Energy's Rocky Flats Environmental Technology Site that was conducted by the

  11. Independent Oversight Special Review, Rocky Flats Closure Project Site -

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    April 2001 | Department of Energy Rocky Flats Closure Project Site - April 2001 Independent Oversight Special Review, Rocky Flats Closure Project Site - April 2001 April 2001 Special Review of the Rocky Flats Closure Project Site This report provides the results of a Special Review at the Rocky Flats Closure Project that was performed U.S. Department of Energy's (DOE) Office of Independent Environment, Safety, and Health Oversight. The Special Review was conducted in February and March 2001

  12. Geothermal Technologies Program Blue Ribbon Panel Recommendations

    SciTech Connect (OSTI)

    none,

    2011-06-17

    The Geothermal Technologies Program assembled a geothermal Blue Ribbon Panel on March 22-23, 2011 in Albuquerque, New Mexico for a guided discussion on the future of geothermal energy in the United States and the role of the DOE Program. The Geothermal Blue Ribbon Panel Report captures the discussions and recommendations of the experts. An addendum is available here: http://www.eere.energy.gov/geothermal/pdfs/gtp_blue_ribbon_panel_report_addendum10-2011.pdf

  13. Walk-In Panels | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Walk-In Panels Walk-In Panels The Department of Energy (DOE) develops standardized data templates for reporting the results of tests conducted in accordance with current DOE test procedures. Templates may be used by third-party laboratories under contract with DOE that conduct testing in support of ENERGY STAR® verification, DOE rulemakings, and enforcement of the federal energy conservation standards. Walk-In Panels - v1.2.xlsx (70.45 KB) More Documents & Publications Refrigerators and

  14. NREL Employee Appointed to Presidential Panel

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Employee Appointed to Presidential Panel For more information contact: e:mail: Public Affairs Golden, Colo., April 10, 1997 -- Sam Baldwin, international programs director for the U.S. Department of Energy's National Renewable Energy Laboratory (NREL), has been named to the President's Committee of Advisors on Science and Technology (PCAST) as the staff study director for PCAST's Energy Research and Development Panel. The panel will review current and projected U.S. energy research and

  15. MODIFICATIONS TO THE WIPP PANEL CLOSURE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    29 Panel Closure ATTACHMENT 1 NMED COMMENTS ITEM 1 - MODIFICATIONS TO THE WIPP PANEL CLOSURE Page 2 of 29 Panel Closure 1-1: PMR Overview, Section 1, "Revision to the PCS Design" This section needs to explicitly explain which Attachment G1 Appendices are being deleted and which new appendices contain relevant information from old appendices. For example, Appendix B appears to include consolidated relevant information from the previous Appendices B through F; the new Appendix A replaces

  16. Solar Decathlon Technology Spotlight: Structural Insulated Panels...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Structural insulated panels (SIPs) are prefabricated structural elements used to build walls, ceilings, floors, and roofs. Made of foam insulation sandwiched between two layers of ...

  17. Panel Discussion | OpenEI Community

    Open Energy Info (EERE)

    on the project background and history, status updates, analysis summary and future directions. The day ended with a panel discussion, with members including Lee Webb...

  18. OpenEI Community - Panel Discussion

    Open Energy Info (EERE)

    on the project background and history, status updates, analysis summary and future directions. The day ended with a panel discussion, with members including Lee...

  19. Apparatus for manifolding multiple passage solar panel

    SciTech Connect (OSTI)

    Mcalister, R.E.

    1982-06-08

    A method of sealingly connecting a thermoplastic solar panel structure comprising a multiplicity of elongated thin wall sections defining a multiplicity of parallel passages extending longitudinally between the ends of said panel structure to a thermoplastic manifold tube comprising the steps of mounting an elongated mandrel having a multiplicity of transversely projecting elements corresponding in number and spacing to the panel passages to be communicated with the interior of the manifold tube, positioning a side wall portion of the manifold tube in predetermined spaced relation with the open end of the panel structure so that the projecting elements of the mandrel are generally longitudinally aligned with the open ends of a corresponding member of the passages in the panel structure, heating the spaced panel structure end and the manifold tube side wall portion to soften the thermoplastic material thereof, moving the mandrel within the manifold tube so as to position the projecting elements through the side wall portion thereof and into the open ends of said corresponding panel structure passages and the manifold tube toward the panel structure end so as to cause the manifold tube side wall portion to apply a pressure to the panel structure end sufficient to deform the thermoplastic material thereof and effect a fusing of the same into a unitary mass, and withdrawing the mandrel in the direction of extent of the projecting elements to a position within the interior of the manifold tube and then longitudinally out of the manifold tube and apparatus for carrying out the method.

  20. MINUTES FROM SEISMIC LESSONS-LEARNED PANEL

    Office of Environmental Management (EM)

    ... Publishing such calculations will allow others to reference the method and prevent ... Process, as acceptable for use. The panel expressed consensus in 2009 that these new ...

  1. Federal Technical Capability Panel Conference Call Minutes -...

    Energy Savers [EERE]

    Federal Technical Capability Panel Conference Call Minutes January 20, 2016 Karen Boardman, Chair, not in attendance. Participating in DOE HQ Conference Call. Dave Chaney, Deputy ...

  2. Risk-Quantified Decision-Making at Rocky Flats

    SciTech Connect (OSTI)

    Myers, Jeffrey C.

    2008-01-15

    Surface soils in the 903 Pad Lip Area of the Rocky Flats Environmental Technology Site (RFETS) were contaminated with {sup 239/240}Pu by site operations. To meet remediation goals, accurate definition of areas where {sup 239/240}Pu activity exceeded the threshold level of 50 pCi/g and those below 50- pCi/g needed definition. In addition, the confidence for remedial decisions needed to be quantified and displayed visually. Remedial objectives needed to achieve a 90 percent certainty that unremediated soils had less than a 10 percent chance of {sup 239/240}Pu activity exceeding 50-pCi/g. Removing areas where the chance of exceedance is greater than 10 percent creates a 90 percent confidence in the remedial effort results. To achieve the stipulated goals, the geostatistical approach of probability kriging (Myers 1997) was implemented. Lessons learnt: Geostatistical techniques provided a risk-quantified approach to remedial decision-making and provided visualizations of the excavation area. Error analysis demonstrated compliance and confirmed that more than sufficient soils were removed. Error analysis also illustrated that any soils above the threshold that were not removed would be of nominal activity. These quantitative approaches were useful from a regulatory, engineering, and stakeholder satisfaction perspective.

  3. Display device for indicating the value of a parameter in a process plant

    DOE Patents [OSTI]

    Scarola, Kenneth; Jamison, David S.; Manazir, Richard M.; Rescorl, Robert L.; Harmon, Daryl L.

    1993-01-01

    An advanced control room complex for a nuclear power plant, including a discrete indicator and alarm system (72) which is nuclear qualified for rapid response to changes in plant parameters and a component control system (64) which together provide a discrete monitoring and control capability at a panel (14-22, 26, 28) in the control room (10). A separate data processing system (70), which need not be nuclear qualified, provides integrated and overview information to the control room and to each panel, through CRTs (84) and a large, overhead integrated process status overview board (24). The discrete indicator and alarm system (72) and the data processing system (70) receive inputs from common plant sensors and validate the sensor outputs to arrive at a representative value of the parameter for use by the operator during both normal and accident conditions, thereby avoiding the need for him to assimilate data from each sensor individually. The integrated process status board (24) is at the apex of an information hierarchy that extends through four levels and provides access at each panel to the full display hierarchy. The control room panels are preferably of a modular construction, permitting the definition of inputs and outputs, the man machine interface, and the plant specific algorithms, to proceed in parallel with the fabrication of the panels, the installation of the equipment and the generic testing thereof.

  4. Instrument for assaying radiation

    DOE Patents [OSTI]

    Coleman, Jody Rustyn; Farfan, Eduardo B.

    2016-03-22

    An instrument for assaying radiation includes a flat panel detector having a first side opposed to a second side. A collimated aperture covers at least a portion of the first side of the flat panel detector. At least one of a display screen or a radiation shield may cover at least a portion of the second side of the flat panel detector.

  5. AQUEOUS HOMOGENEOUS REACTORTECHNICAL PANEL REPORT

    SciTech Connect (OSTI)

    Diamond, D.J.; Bajorek, S.; Bakel, A.; Flanagan, G.; Mubayi, V.; Skarda, R.; Staudenmeier, J.; Taiwo, T.; Tonoike, K.; Tripp, C.; Wei, T.; Yarsky, P.

    2010-12-03

    Considerable interest has been expressed for developing a stable U.S. production capacity for medical isotopes and particularly for molybdenum- 99 (99Mo). This is motivated by recent re-ductions in production and supply worldwide. Consistent with U.S. nonproliferation objectives, any new production capability should not use highly enriched uranium fuel or targets. Conse-quently, Aqueous Homogeneous Reactors (AHRs) are under consideration for potential 99Mo production using low-enriched uranium. Although the Nuclear Regulatory Commission (NRC) has guidance to facilitate the licensing process for non-power reactors, that guidance is focused on reactors with fixed, solid fuel and hence, not applicable to an AHR. A panel was convened to study the technical issues associated with normal operation and potential transients and accidents of an AHR that might be designed for isotope production. The panel has produced the requisite AHR licensing guidance for three chapters that exist now for non-power reactor licensing: Reac-tor Description, Reactor Coolant Systems, and Accident Analysis. The guidance is in two parts for each chapter: 1) standard format and content a licensee would use and 2) the standard review plan the NRC staff would use. This guidance takes into account the unique features of an AHR such as the fuel being in solution; the fission product barriers being the vessel and attached systems; the production and release of radiolytic and fission product gases and their impact on operations and their control by a gas management system; and the movement of fuel into and out of the reactor vessel.

  6. Buckling behavior of stiffened panels under static and dynamic loading with particular emphasis on the response of the stiffener outstands

    SciTech Connect (OSTI)

    Louca, L.A.; Harding, J.E.

    1995-12-31

    This paper presents results on the buckling behavior of stiffened panels loaded axially under static loading and dynamically under transverse blast pressures. Particular emphasis is placed on the torsional behavior of the outstands. The study has been carried out using non-linear finite element (FE) packages and plastic mechanism techniques. For the static analysis, an FE package (LUSAS) has been used to obtain load deflection curves, including both the peak load and the unloading characteristic for a range of geometries. The responses of stiffened panels subjected to blast loading have also been investigated using various pressure time curves. Both a simple model, consisting of a flat-panel and an individual stiffener and a more complex model of a complete blast wall have been analyzed. The analysis package (DYNA3D) accounts for material and geometric non-linearities and strain rate effects which can significantly influence the capacity of the panel. As for the static results, the dynamic analyses have been correlated with previous experimental results. The effect of tripping is shown to have a significant influence on the response, and earlier yield of the panel, when the stiffeners are in compression, is highlighted. It is also shown that provided there is adequate in-plane support to allow the panels to develop membrane action, blast pressures exceeding one bar can be resisted.

  7. Briefing package for the Yucca Flat pre-emptive review, including overview, UZ model, SZ volcanics model and summary and conclusions sections

    SciTech Connect (OSTI)

    Kwicklis, Edward Michael; Keating, Elizabeth H

    2010-12-02

    Much progress has been made in the last several years in modeling radionuclide transport from tests conducted both in the unsaturated zone and saturated volcanic rocks of Yucca Flat, Nevada. The presentations to the DOE NNSA pre-emptive review panel contained herein document the progress to date, and discuss preliminary conclusions regarding the present and future extents of contamination resulting from past nuclear tests. The presentations also discuss possible strategies for addressing uncertainty in the model results.

  8. Gas pump with movable gas pumping panels

    DOE Patents [OSTI]

    Osher, John E.

    1984-01-01

    Apparatus for pumping gas continuously a plurality of articulated panels of getter material, each of which absorbs gases on one side while another of its sides is simultaneously reactivated in a zone isolated by the panels themselves from a working space being pumped.

  9. Kingspan Insulated Panels: Order (2013-CE-5353)

    Broader source: Energy.gov [DOE]

    DOE ordered Kingspan Insulated Panels, Inc. to pay a $8,000 civil penalty after finding Kingspan Insulated Panels had failed to certify that any basic models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

  10. Method of making a solar panel

    SciTech Connect (OSTI)

    Anderson, J.R.; Dominguez, R.

    1982-05-25

    A solar panel in which interconnected photovoltaic cells are maintained in light-receiving position by electrically conductive clips secured to the base of the panel. When the cells and clips are encapsulated in a protective resin, a vacuum is drawn during encapsulation to remove air bubbles trapped beneath the cells.