WorldWideScience

Sample records for beta backscattering gages

  1. Card controlled beta backscatter thickness measuring instrument

    International Nuclear Information System (INIS)

    An improved beta backscatter instrument for the nondestructive measurement of the thickness of thin coatings on a substrate is described. Included therein is the utilization of a bank of memory stored data representative of isotope, substrate, coating material and thickness range characteristics in association with a control card having predetermined indicia thereon selectively representative of a particular isotope, substrate material, coating material and thickness range for conditioning electronic circuit means by memory stored data selected in accord with the predetermined indicia on a control card for converting backscattered beta particle counts into indicia of coating thickness

  2. High-precision thickness measurements using beta backscatter

    International Nuclear Information System (INIS)

    A two-axis, automated fixture for use with a high-intensity Pm-147 source and a photomultiplier-scintillation beta-backscatter probe for making thickness measurements has been designed and built. A custom interface was built to connect the system to a minicomputer, and software was written to position the tables, control the probe, and make the measurements. Measurements can be made in less time with much greater precision than by the method previously used

  3. Importance of the radiometric ash content determination by means of beta backscattering for coal transformation

    International Nuclear Information System (INIS)

    The radiometric method for ash content determination based on beta backscattering has been evaluated from the point of view of quality control and quality assurance in lignite mining and use of lignite. Applying the method, optimum control and distribution to generation of power, briquetting or coal transformation depending on ash content is possible

  4. Development of a semi-automatic beta-backscatter thickness-measuring system

    International Nuclear Information System (INIS)

    The semi-automated beta-backscatter system was evaluated to determine the overall system capability. The capability studies performed on the system indicate that the system can measure aluminum nominally 11.33 μm (450 μin.) thick on a Kapton substrate to a precision of better than 0.72 percent (one standard deviation = +- 0.0816 μm) in a time interval of 10 seconds. The report also covers various fail safe devices installed in the positioning fixture, and changes made in the system's software to facilitate operation of the system and storage of data

  5. Streamflow Gaging Stations

    Data.gov (United States)

    Department of Homeland Security — This map layer shows selected streamflow gaging stations of the United States, Puerto Rico, and the U.S. Virgin Islands, in 2013. Gaging stations, or gages, measure...

  6. Storage Gage Precipitation Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A storage gage is a precipitation gage that requires reading and maintenance only monthly or seasonal intervals. This library includes reports from such gages,...

  7. Radioisotope gage for automatic control of cotton wool package

    International Nuclear Information System (INIS)

    A summary is given of research work and in-service tests carried out on radiometric gages for on-line control in bandage industry. A special type of thickness gage based on beta absorption measurements restricts the weight fluctuations of ready cotton wool packages to less than +- 2 per cent. Economic effectiveness of the gage is evaluated

  8. NOVA 201 ultrasonic thickness gage (NOVA Gage)

    Science.gov (United States)

    Garecht, Diane

    1990-01-01

    The measurement integrity of the NOVA 201 digital ultrasonic thickness gage (NOVA gage) was demonstrated by comparing the NOVA gage measurements to the thickness gage measurements, and determining the bias and uncertainty of the NOVA gage when measuring redesigned solid rocket motor (RSRM) hardware per engineering test plans (ETP). The NOVA gage was tested by three different operators on steel and aluminum RSRM hardware for wall thickness. The results show that the measurement bias is not consistent. The uncertainty of the bias is caused by the heterogeneous material properties of the RSRM components that influence the time of flight of ultrasonic waves. The measurement uncertainty inherent to the design and operation of the NOVA gage is less in comparison to the uncertainty of the bias. The total measurement uncertainty cannot be substantially reduced by taking more than one measurement. There is no correlation between bias and the surface finish range of this test unless 3-in-One oil is used as a couplant, in which case there appears to be a slight trend. There is no correlation between uncertainty and the surface finish range. The measurement uncertainty of the NOVA gage can be reduced using 3-in-One oil as a couplant.

  9. Strain gage balances and buffet gages

    Science.gov (United States)

    Ferris, A. T.

    1983-01-01

    One-piece strain gage force balances were developed for use in the National Transonic Facility (NTF). This was accomplished by studying the effects of the cryogenic environment on materials, strain gages, cements, solders, and moisture proofing agents, and selecting those that minimized strain gage output changes due to temperature. In addition, because of the higher loads that may be imposed by the NTF, these balances are designed to carry a larger load for a given diameter than conventional balances. Full cryogenic calibrations were accomplished, and wind tunnel results that were obtained from the Langley 0-3-Meter Transonic Cryogenic Tunnel were used to verify laboratory test results.

  10. Palladium-chromium static strain gages for high temperatures

    Science.gov (United States)

    Lei, Jih-Fen

    1992-01-01

    An electrical resistance strain gage that can provide accurate static strain measurement to a temperature of 1500 F or above is being developed both in fine wire and thin film forms. The gage is designed to be temperature compensated on any substrate material. It has a dual element: the gage element is a special alloy, palladium-13wt percent chromium (PdCr), and the compensator element is platinum (Pt). Earlier results of a PdCr based wire gage indicated that the apparent strain of this gage can be minimized and the repeatability of the apparent strain can be improved by prestabilizing the gage on the substrate for a long period of time. However, this kind of prestabilization is not practical in many applications and therefore the development of a wire gage which is prestabilized before installation on the substrate is desirable. This paper will present our recent progress in the development of a prestabilized wire gage which can provide meaningful strain data for the first thermal cycle. A weldable PdCr gage is also being developed for field testing where conventional flame-spraying installation can not be applied. This weldable gage is narrower than a previously reported gage, thereby allowing the gage to be more resistant to buckling under compressive loads. Some preliminary results of a prestabilized wire gage flame-sprayed directly on IN100, an engine material, and a weldable gage spot-welded on IN100 and SCS-6/(beta)21-S Titanium Matrix Composite (TMC), a National Aero-Space Plane (NASP) structure material, will be reported. Progress on the development of a weldable thin film gage will also be addressed. The measurement technique and procedures and the lead wire effect will be discussed.

  11. RF modal quantity gaging

    Science.gov (United States)

    Vanleuven, K.

    1989-05-01

    The primary objective is to provide a concept of a radio frequency (RF) modal resonance technique which is being investigated as a method for gaging the quantities of subcritical cryogenic propellants in metallic tanks. Of special interest are the potential applications of the technique to microgravity propellant gaging situations. The results of concept testing using cryogenic oxygen, hydrogen, and nitrogen, as well as paraffin simulations of microgravity fluid orientations, are reported. These test results were positive and showed that the gaging concept was viable.

  12. GAGES-II: Geospatial Attributes of Gages for Evaluating Streamflow

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset, termed "GAGES II", an acronym for Geospatial Attributes of Gages for Evaluating Streamflow, version II, provides geospatial data and classifications...

  13. Development of reversible strain gage

    International Nuclear Information System (INIS)

    A high-temperature strain gage which can be peeled after taking required apparent strain measurements in a furnace and can be attached reverse-side-up at the point of interest on a test structure was developed. Using the ''reversible'' strain gage with selected room-temperature curing type polyester adhesive, one can expect to measure thermal strain accurately, especially for on large structures, at the first test in temperature up to 250 deg C. The repeatability of apparent strains for about 100 reversible gages was within 50 microstrains of difference at 250 deg C (within 30 microstrains of difference for 80 % of the test gages). (author)

  14. Low-g propellant gaging

    Science.gov (United States)

    Orton, George

    1987-09-01

    A program to develop and demonstrate technology for low gravity propellant gaging on future geostationary satellites is described. Evaluations were performed to select four gaging concepts for ground tests and low gravity tests in the NASA KC-135 aircraft. The selected concepts were: (1) an ultrasonic point sensor system, (2) a nucleonic gaging system, (3) an ultrasonic torsional wave guide, and (4) an ultrasonic flowmeter. As a result of successful ground and KC-135 tests, two concepts (the ultrasonic point sensor and the nucleonic systems) were selected for orbital test in a shuttle Get-Away-Special experiment.

  15. Temperature controlled strain gaged extensometer

    Science.gov (United States)

    Ramos, G. L.; Seplow, S.

    1968-01-01

    Temperature controlled strain-gaged extensometer measures longitudinal and girth deflections of pressure vessels in excess of one percent strain during pressurization and depressurization with cryogenic fluids at cryogenic temperatures. The device is of beryllium-copper strips.

  16. Electrical properties of materials for elevated temperature resistance strain gage application. Ph.D. Thesis

    International Nuclear Information System (INIS)

    The objective was to study the electrical resistances of materials that are potentially useful as resistance strain gages at 1000 C. Transition metal carbides and nitrides, boron carbide and silicon carbide were selected for the experimental phase of this research. Due to their low temperature coefficient of resistance and good stability, TiC, ZrC, B sub 4 C and beta-SiC are suggested as good candidates for high temperature resistance strain gage applications

  17. Propellant gaging for geostationary satellites

    Science.gov (United States)

    Orazietti, A. J.; Orton, G. F.; Schreib, R.

    1986-06-01

    Evaluations were performed to select four gaging concepts for ground tests and low-g tests in the NASA KC-135 aircraft. The selected concepts were an ultrasonic point sensor system, a nucleonic gaging system, an ultrasonic torsional wave guide, and an ultrasonic flowmeter. The first three systems provide a direct measurement of propellant quantity remaining, while the fourth system integrates (totalizes) the propellant flow to the engines and infers propellant remaining based on a known initial propellant load. As a result of successful ground and KC-135 tests, two concepts (the ultrasonic point sensor and nucleonic systems) were selected for orbital test in a Shuttle Get-Away-Special experiment. These systems offer high end-of-life accuracy potential, are nonintrusive (external to the tanks and feedlines), and are low in risk because of their good technology base. The Shuttle Get-Away-Special experiment has been assembled and passed flight certification testing in late April 1986.

  18. High-Temperature Adhesive Strain Gage Developed

    Science.gov (United States)

    Pereira, J. Michael; Roberts, Gary D.

    1997-01-01

    Researchers at the NASA Lewis Research Center have developed a unique strain gage and adhesive system for measuring the mechanical properties of polymers and polymer composites at elevated temperatures. This system overcomes some of the problems encountered in using commercial strain gages and adhesives. For example, typical commercial strain gage adhesives require a postcure at temperatures substantially higher than the maximum test temperature. The exposure of the specimen to this temperature may affect subsequent results, and in some cases may be higher than the glass-transition temperature of the polymer. In addition, although typical commercial strain gages can be used for short times at temperatures up to 370 C, their long-term use is limited to 230 C. This precludes their use for testing some high-temperature polyimides near their maximum temperature capability. Lewis' strain gage and adhesive system consists of a nonencapsulated, unbacked gage grid that is bonded directly to the polymer after the specimen has been cured but prior to the normal postcure cycle. The gage is applied with an adhesive specially formulated to cure under the specimen postcure conditions. Special handling, mounting, and electrical connection procedures were developed, and a fixture was designed to calibrate each strain gage after it was applied to a specimen. A variety of tests was conducted to determine the performance characteristics of the gages at elevated temperatures on PMR-15 neat resin and titanium specimens. For these tests, which included static tension, thermal exposure, and creep tests, the gage and adhesive system performed within normal strain gage specifications at 315 C. An example of the performance characteristics of the gage can be seen in the figure, which compares the strain gage measurement on a polyimide specimen at 315 C with an extensometer measurement.

  19. Low TCR nanocomposite strain gages

    Science.gov (United States)

    Gregory, Otto J. (Inventor); Chen, Ximing (Inventor)

    2012-01-01

    A high temperature thin film strain gage sensor capable of functioning at temperatures above 1400.degree. C. The sensor contains a substrate, a nanocomposite film comprised of an indium tin oxide alloy, zinc oxide doped with alumina or other oxide semiconductor and a refractory metal selected from the group consisting of Pt, Pd, Rh, Ni, W, Ir, NiCrAlY and NiCoCrAlY deposited onto the substrate to form an active strain element. The strain element being responsive to an applied force.

  20. Streamflow Gaging Stations of the United States - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows selected streamflow gaging stations of the United States, Puerto Rico, and the U.S. Virgin Islands, in 2013. Gaging stations, or gages, measure...

  1. Neutron moisture gage for bulk material

    International Nuclear Information System (INIS)

    Desing and operation of neutron moisture gage of bulk materials intended for the determination of moisture of coke, agglomerated charge, and iron ore concentrate in black metallurgy is described. The moisture gage operates both under ''measurement'' and ''calibration'' conditions, contains a fast neutron source, and two groups of slow neutron detectors. Technical and economic efficiency of the moisture gage utilization consists in the improved accuracy of moisture detection at the expense of more accurate calibration, optimum arrangement of the carriage in a hopper, and stabilization of detector temperature. The device service is also simplified

  2. A magnifying scratch-gage force transducer

    Science.gov (United States)

    Scott, C. E.

    1969-01-01

    Single-component scratch-gage transducer incorporates a unique motion magnification scheme to increase the magnitude of the load measuring scratch approximately 15 times over that of conventional models. It is small, load carrying and high in natural frequency.

  3. Dual active surface heat flux gage probe

    Science.gov (United States)

    Liebert, Curt H.; Kolodziej, Paul

    1995-02-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  4. Dynamic coherent backscattering mirror

    Energy Technology Data Exchange (ETDEWEB)

    Zeylikovich, I.; Xu, M., E-mail: mxu@fairfield.edu [Physics Department, Fairfield University, Fairfield, CT 06824 (United States)

    2016-02-15

    The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the direction space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the spatial space. The random medium behaves as a reciprocity mirror which robustly converts a diverging incident beam into a converging backscattering one focusing at a conjugate spot in space. Here we first analyze theoretically this coherent backscattering mirror (CBM) phenomenon and then demonstrate the capability of CBM compensating and correcting both static and dynamic phase distortions occurring along the optical path. CBM may offer novel approaches for high speed dynamic phase corrections in optical systems and find applications in sensing and navigation.

  5. Transient temperature response of strain gages

    International Nuclear Information System (INIS)

    When an electrical resistance strain gage bonded to a material is subjected to a temperature change, the resistance of the strain gage changes even though the material is free of stress. This temperature-induced resistance change is generally expressed in strain units and is commonly called apparent strain or thermal output. The thermal expansion coefficients and the temperature coefficient of resistance are temperature-dependent quantities and not necessarily linearly related to temperature. For transient temperature conditions, the two temperatures are different. The magnitude and effect of this temperature difference on apparent strain is studied

  6. Low pressure gage type VM-01

    International Nuclear Information System (INIS)

    High vacuum systems became an important element of many applied technologies, from gas analysers to rocket engines. An intelligent apparatus for pressure measurement in the range of 10-3 - 10-8 mbar, with incorporated INTEL 80C51 microcontroller is presented. Based on a Bayard-Alpert hot cathode gage, equally developed in our institute, the pressure gage allows the displaying of different operation parameters and also of the error codes for different kinds of malfunctioning, as for instance missing of grid voltage, grid-collector breakdown, pressure increasing above 10-3 mbar. Its operation is based on a microcontroller assembly language program especially worked out and introduced in the central units EPROM memory. The gage characteristics for different gases are also introduced in an EPROM memory, and the type of the gas is selected by the operator from the front panel. One can select also from the front panel the pressure unit (mbar, torr, Pa). If a remote control is necessary, this can be done by means of a PC, with a program written in the LabVIEW graphical programming language. The pressure gage was tested and calibrated in relation with an EDWARDS vacuum measuring system and provided a good accuracy (better than 25%). Its field of application is both laboratory and industrial measurements. Its main features are: - supply voltage, 220 V ac / 50 Hz; - power consumption, 30 W; - gage's grid supply voltage, 160 V; grid current, 2 mA / p = 10 -5...10-8 mbar and 0.2 mA / p = 10-3...10-5 mbar; - cathode heating current, max. 3 A; - measuring range, 10-3...10-8 mbar; - error of measurement, ±35%; - remote control, according to the RS232 standard; - size, 320 x 200 x 100 mm; - weight, 3.5 Kg. (authors)

  7. Evaluation of OTT PLUVIO Precipitation Gage versus Belfort Universal Precipitation Gage 5-780 for the National Atmospheric Deposition Program

    Science.gov (United States)

    Tumbusch, Mary L.

    2003-01-01

    The National Atmospheric Deposition Program, a cooperative effort supported by Federal, State, and local agencies, and Indian Tribes, was established in 1977 to study atmospheric deposition and its impact on the environment. The program's National Trends Network now includes wet-deposition networks at more than 250 sites across the United States, Canada, Puerto Rico, and the Virgin Islands. Precipitation amounts are currently measured using a Belfort Universal Precipitation Gage 5-780, which involves technology that is more than 50 years old. In 1999, a three-phase study was begun to evaluate several weighing, all-weather precipitation gages to find a possible replacement for the Belfort Universal Precipitation Gage 5-780. One gage that performed consistently well in phase I and II testing was the OTT PLUVIO Precipitation Gage. Phase III of the study, discussed herein, was to determine the accuracy and comparability of the data sets collected by the OTT PLUVIO Precipitation Gages and the existing Belfort Universal Precipitation Gage 5-780. Seven OTT PLUVIO Precipitation Gages were installed at six National Trends Network sites across the country for a data-collection period of approximately 18 months. The NovaLynx Model 260-2510 Standard Rain and Snow Gage also was used, as a reference, at two of the sites. Paired t-tests analysis showed no significant differences in precipitation measurements between the Belfort Universal Precipitation Gage 5-780 and the OTT PLUVIO Precipitation Gages at three of the six sites. When the false positives were removed from the precipitation-event data sets, the gages at all sites were in agreement and the paired t-tests showed the gage measurements were not significantly different. A false positive is defined as a zero response from the Belfort Universal Precipitation Gage 5-780 concurrent with a recorded response from the OTT PLUVIO Precipitation Gage.

  8. Assessment of current high-temperature strain gages

    International Nuclear Information System (INIS)

    Long-term stability tests for systematic drift and strain sensitivity (gage factor) were conducted on two types of capacitive strain gages - the Boeing differential-capacitance gage and the CERL-Planer variable gap capacitive strain transducer - and on the Ailtech SG-425 resistance gage. Results for tests of durations up to 12,000 hr are presented and compared with similar tests reported by others. The stability and repeatability of the capacitive systems were verified. In addition, two short-term investigations were made on Ailtech weldable-resistance gages to address areas of uncertainty related to special applications. Data from these tests are also presented and interpreted. Advantages and limitations of the various systems are identified, and conclusions and recommendations are presented. Descriptions of the gage systems and problems encountered in the use of capacitive gages are given in appendices

  9. Investigation on the determination of the leaf water status of greenhouse cucumbers by means of β-ray gaging

    International Nuclear Information System (INIS)

    The leaf water status of intact greenhouse cucumber plants was determined by the β-ray gaging technique. The measurements were performed in a leaf inserted in medium height. To observe the geometry of the leaf to be measured, a measuring device with emitter and detector has been developed. It could be shown, that the daily plant water balance depending on climatic factors and the change of the soil moisture after sprinkler irrigation as well as the influence of the wettening of the leaf on the moisture status of the plant could be determined by means of the chosen experimental device. Between the values measured by beta gaging and the velocity of the sap flow a linear relation was found. The β-ray gaging technique proved to be well suited for studies on the influence of environmental factors on the water balance of greenhouse cucumbers

  10. Precision geometric parameter gage for synchrotron radiation

    CERN Document Server

    Gubrienko, K I; Makonin, S; Seleznev, V; Solodovnik, F; Sytin, A N; Vrazhnov, M; Wittenburg, K

    2001-01-01

    This article includes the description of the geometric parameter gage device prototype for synchrotron radiation of HERA collider (DESY). The system construction which capable to measure photo current, caused by such a radiation in a refractory metal, described here. The system component parts are: measuring heads and photo current measuring electronics designed by IHEP, stepper motor by Vacuum Generators with HEDS-550X encoder by Hewlett Packard, PCI-STEP-4CX 4-Axis Closed Loop Step controller by National Instruments. The device is controlled by means of Microsoft Visual Basic program using Value Motion Windows Libraries. The device prototype was tested in the beam of the DORIS storage ring.

  11. Development of reinstrumenting technique of fuel rods with pressure gages

    International Nuclear Information System (INIS)

    Comprehensive procedures were designed in order to reinstrument irradiated fuel rods with fission gas pressure gages and measure inner pressure of the fuel rods in following re-irradiation experiments. The procedures have necessitated development of wide-ranging techniques which have been successfully being carried out. This report outlines the reinstrumenting procedures and summarizes in and out-of-pile characteristics of the developed pressure gage. Efforts were made to provide designed performance in fabrication process, which resulted in several revisions in the pressure gage design. In and out-of-pile performance tests verified successful workability of the developed pressure gage under expected service environments. (author)

  12. THERMAL NEUTRON BACKSCATTER IMAGING.

    Energy Technology Data Exchange (ETDEWEB)

    VANIER,P.; FORMAN,L.; HUNTER,S.; HARRIS,E.; SMITH,G.

    2004-10-16

    Objects of various shapes, with some appreciable hydrogen content, were exposed to fast neutrons from a pulsed D-T generator, resulting in a partially-moderated spectrum of backscattered neutrons. The thermal component of the backscatter was used to form images of the objects by means of a coded aperture thermal neutron imaging system. Timing signals from the neutron generator were used to gate the detection system so as to record only events consistent with thermal neutrons traveling the distance between the target and the detector. It was shown that this time-of-flight method provided a significant improvement in image contrast compared to counting all events detected by the position-sensitive {sup 3}He proportional chamber used in the imager. The technique may have application in the detection and shape-determination of land mines, particularly non-metallic types.

  13. Restriction of GAGE protein expression to subpopulations of cancer cells is independent of genotype and may limit the use of GAGE proteins as targets for cancer immunotherapy

    DEFF Research Database (Denmark)

    Gjerstorff, M F; Johansen, L E; Nielsen, O;

    2006-01-01

    , and most GAGE-positive tumours also contained cancer cells lacking GAGE expression. Studies of genetically homogenous cell lines with similar intercellular heterogeneous GAGE expression showed that GAGE expression was not associated with a specific genotype, but defined a phenotypically distinct...

  14. How the Schmidt-Boelter gage really works

    International Nuclear Information System (INIS)

    The Schmidt-Boelter gage is but one version of a proven heat flux measurement concept generally referred to as the axial temperature gradient method. This gage has been used since the mid-1950's and has gained wide acceptance because the transducer provides a high-level, self-generating output signal directly proportional to the heat flux incident upon the sensing surface. Utilization of this transducer in aerospace measurements since the late 1970's has broadened the scope of application of the device, but has raised questions concerning the proper interpretation of the results. The principle of operation of the gage can correctly be divided into two distinct categories-the thermal and thermoelectric functions. The thermal response of the gage can be approximated by simple steady-state equations. But due to the number of different materials required in the construction of the gage, the transient temperature and heat conduction in gage members are more accurately characterized by finite-element thermal analysis techniques. Results of these analyses are presented in graphical format in the paper. Thermoelectric characteristics of the gage are accurately defined by basic principles of thermoelectric thermometry. Altogether, the analyses presented in this paper demonstrate how this transducer actually works. The conclusions presented herein may be different than opinions held by most casual users regarding gage operation. Results of limited laboratory experiments which support the analyses are described and presented

  15. 16 CFR Figure 2 to Part 1511 - Small Parts Gage

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Small Parts Gage 2 Figure 2 to Part 1511 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT REGULATIONS REQUIREMENTS FOR PACIFIERS Pt.1511, Fig. 2 Figure 2 to Part 1511—Small Parts Gage EC03OC91.069...

  16. USGS Small-scale Dataset - Streamflow Gaging Stations of the United States 201403 Shapefile

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows selected streamflow gaging stations of the United States, Puerto Rico, and the U.S. Virgin Islands, in 2013. Gaging stations, or gages, measure...

  17. Heat-Flux Gage thermophosphor system

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, K.W.

    1991-08-01

    This document describes the installation, hardware requirements, and application of the Heat-Flux Gage (Version 1.0) software package developed by the Oak Ridge National Laboratory, Applied Technology Division. The developed software is a single component of a thermographic phosphor-based temperature and heat-flux measurement system. The heat-flux transducer was developed by EG G Energy Measurements Systems and consists of a 1- by 1-in. polymethylpentene sheet coated on the front and back with a repeating thermographic phosphor pattern. The phosphor chosen for this application is gadolinium oxysulphide doped with terbium. This compound has a sensitive temperature response from 10 to 65.6{degree}C (50--150{degree}F) for the 415- and 490-nm spectral emission lines. 3 refs., 17 figs.

  18. Monitoring Everglades freshwater marsh water level using L-band synthetic aperture radar backscatter

    Science.gov (United States)

    Kim, Jin-Woo; Lu, Zhong; Jones, John W.; Shum, C.K.; Lee, Hyongki; Jia, Yuanyuan

    2014-01-01

    The Florida Everglades plays a significant role in controlling floods, improving water quality, supporting ecosystems, and maintaining biodiversity in south Florida. Adaptive restoration and management of the Everglades requires the best information possible regarding wetland hydrology. We developed a new and innovative approach to quantify spatial and temporal variations in wetland water levels within the Everglades, Florida. We observed high correlations between water level measured at in situ gages and L-band SAR backscatter coefficients in the freshwater marsh, though C-band SAR backscatter has no close relationship with water level. Here we illustrate the complementarity of SAR backscatter coefficient differencing and interferometry (InSAR) for improved estimation of high spatial resolution water level variations in the Everglades. This technique has a certain limitation in applying to swamp forests with dense vegetation cover, but we conclude that this new method is promising in future applications to wetland hydrology research.

  19. The role of GAGE cancer/testis antigen in metastasis

    DEFF Research Database (Denmark)

    Gjerstorff, Morten Frier; Terp, Mikkel Green; Hansen, Malene Bredahl;

    2016-01-01

    metastatic (M4A4) and moderately metastatic clones (LM3), stable downregulation of GAGE expression did not affect the ability of CL16 cells to establish primary tumors and form metastasis in the lungs of immunodeficient mice. CONCLUSIONS: These results suggest that GAGE proteins per se do not support...... isogenic cell lines, which are equally tumorigenic in immunodeficient mice, but differ with their ability to generate metastases in the lungs and lymph nodes. RESULTS: Although GAGE proteins were strongly upregulated in the highly metastatic clone (CL16) compared to non-metastatic (NM2C5), weakly...

  20. Backscatter imagery in Jobos Bay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 1x1 meter resolution backscatter mosaic of Jobos Bay, Puerto Rico (in NAD83 UTM 19 North). The backscatter values are in relative 8-bit (0 –...

  1. Speckle reduction methods for laser line gages

    Science.gov (United States)

    Harding, Kevin G.

    1997-12-01

    Speckle caused by the use of laser sources is a well known phenomena. For some applications, the presence of the speckle is used as part of the method, but in others it is purely a source of noise. In the case of line based laser gages, speckle is typically of considerable concern. Certainly, using white light sources or LEDs with short coherence is one way around this problem, but such methods also loose some of the valuable properties of laser line projection such as very narrow lines, the ability to create multiple lines by diffraction, and high signal to background through the use of bandpass filters to view only the laser wavelength. There have been a number of valuable tools introduced that help reduce the problem of speckle from laser sources, without giving up all the advantages of the laser itself. This paper reviews the pros and cons of a number of these methods, and suggests a specific set of tools that are specific to laser line projection.

  2. NASA LaRC Strain Gage Balance Design Concepts

    Science.gov (United States)

    Rhew, Ray D.

    1999-01-01

    The NASA Langley Research Center (LaRC) has been designing strain-gage balances for more than fifty years. These balances have been utilized in Langley's wind tunnels, which span over a wide variety of aerodynamic test regimes, as well as other ground based test facilities and in space flight applications. As a result, the designs encompass a large array of sizes, loads, and environmental effects. Currently Langley has more than 300 balances available for its researchers. This paper will focus on the design concepts for internal sting mounted strain-gage balances. However, these techniques can be applied to all force measurement design applications. Strain-gage balance concepts that have been developed over the years including material selection, sting, model interfaces, measuring, sections, fabrication, strain-gaging and calibration will be discussed.

  3. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  4. Evaluation test on stability of high temperature strain gage

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Toshimi (Kyowa Electronic Instruments Co. Ltd., Tokyo (Japan)); Ito, Haruhiko; Tanaka, Isao; Komori, Yoshihiro

    1983-08-01

    This report deals with the results on a stability test of high temperature strain gage which is utilized for development of the Stethoscope for OGL - 1 Components in Elevated Temperature Services (ab. SOCETS). The test has proved that the weldable strain gage (KHC - 20 - G5) exhibits excellent stability at 500/sup 0/C during 3000 to 4000 hours service and can be applied sufficiently to evaluate integrity of OGL - 1 high temperature pipings and others.

  5. Evaluation test on stability of high temperature strain gage

    International Nuclear Information System (INIS)

    This report deals with the results on a stability test of high temperature strain gage which is utilized for development of the Stethoscope for OGL - 1 Components in Elevated Temperature Services (ab. SOCETS). The test has proved that the weldable strain gage (KHC - 20 - G5) exhibits excellent stability at 5000C during 3000 to 4000 hours service and can be applied sufficiently to evaluate integrity of OGL - 1 high temperature pipings and others. (author)

  6. Strain gage selection in loads equations using a genetic algorithm

    Science.gov (United States)

    1994-01-01

    Traditionally, structural loads are measured using strain gages. A loads calibration test must be done before loads can be accurately measured. In one measurement method, a series of point loads is applied to the structure, and loads equations are derived via the least squares curve fitting algorithm using the strain gage responses to the applied point loads. However, many research structures are highly instrumented with strain gages, and the number and selection of gages used in a loads equation can be problematic. This paper presents an improved technique using a genetic algorithm to choose the strain gages used in the loads equations. Also presented are a comparison of the genetic algorithm performance with the current T-value technique and a variant known as the Best Step-down technique. Examples are shown using aerospace vehicle wings of high and low aspect ratio. In addition, a significant limitation in the current methods is revealed. The genetic algorithm arrived at a comparable or superior set of gages with significantly less human effort, and could be applied in instances when the current methods could not.

  7. Investigation of factors affecting the calibration of strain gage based transducers ('Goodzeit gages') for SSC magnets

    International Nuclear Information System (INIS)

    These transducers are designed to measure stresses on SSC collared coils. They are individually calibrated with a bonded ten-stack of SSC inner coil cable by applying a known load and reading corresponding output from the gages. The transducer is supported by a notched 'backing plate' that allows for bending of the gage beam during calibration or in use with an actual coil. Several factors affecting the calibration and use of the transducers are: the number of times a 'backing plate' is used, the similarities or differences between bonded ten-stacks, and the differences between the ten-stacks and the coil they represent. The latter is probably the most important because a calibration curve is a model of how a transducer should react within a coil. If the model is wrong, the calibration curve is wrong. Information will be presented regarding differences in calibrations between Brookhaven National Labs (also calibrating these transducers) and Fermilab - what caused these differences, the investigation into the differences between coils and ten-stacks, and how they relate to transducer calibration, and some suggestions for future calibrations

  8. Investigation of factors affecting the calibration of strain gage based transducers (''Goodzeit gages'') for SSC magnets

    International Nuclear Information System (INIS)

    These transducers are designed to measure stresses on SSC collared coils. They are individually calibrated with a bonded ten-stack of SSC inner coil cable by applying a known load and reading corresponding output from the gages. The transducer is supported by a notched ''backing plate'' that allows for bending of the gage beam during calibration or in use with an actual coil. Several factors affecting the calibration and use of the transducers are: the number of times a ''backing plate'' is used, the similarities or difficulties between bonded ten-stacks, and the differences between the ten-stacks and the coil they represent. The latter is probably the most important because a calibration curve is a model of how a transducer should react within a coil. If the model is wrong, the calibration curve is wrong. Information will be presented regarding differences in calibrations between Brookhaven National Labs (also calibrating these transducers) and Fermilab -- what caused these differences, the investigation into the differences between coils and ten-stacks and how they relate to transducer calibration, and some suggestions for future calibrations

  9. Skin Friction Gage for Measurements in Hypersonic Flow

    Institute of Scientific and Technical Information of China (English)

    Francois Falempin; Marat Goldfeld; Roman Nestoulia

    2003-01-01

    A description and results of tests of a new small-scale gage for direct measurement of skin friction force are presented in the paper. The gage design provides separated measurement of longitudinal and transversal component of friction force. Application of this scheme provides high sensitivity and necessary high-frequency response of the gage. The tests of the gage were carried out in a blow down wind tunnel at Mach numbers of 2 and 4 within the range of Reynolds numbers Rex from 0.8 to 5 million and in the hot-shot wind tunnel at Mach number 6 and Reynolds numbers Rex= 2.5-10 million. The measurements of skin friction were carried out on a flat plate and on a ramp beyond the shock wave. Simultaneously with the direct measurement of friction in the blow down wind tunnel, the measurements of profiles of average velocities and mass flow rate pulsations were realised. Analysis of measurement errors has shown that the friction gage permits to measure skin friction coefficient on a flat plate with mistake not more than 10%.

  10. Backscatter laser depolarization studies of simulated stratospheric aerosols - Crystallized sulfuric acid droplets

    Science.gov (United States)

    Sassen, Kenneth; Zhao, Hongjie; Yu, Bing-Kun

    1989-01-01

    The optical depolarizing properties of simulated stratospheric aerosols were studied in laboratory laser (0.633 micrometer) backscattering experiments for application to polarization lidar observations. Clouds composed of sulfuric acid solution droplets, some treated with ammonia gas, were observed during evaporation. The results indicate that the formation of minute ammonium sulfate particles from the evaporation of acid droplets produces linear depolarization ratios of beta equivalent to 0.02, but beta equivalent to 0.10 to 0.15 are generated from aged acid cloud aerosols and acid droplet crystalization effects following the introduction of ammonia gas into the chamber. It is concluded that partially crystallized sulfuric acid droplets are a likely candidate for explaining the lidar beta equivalent to 0.10 values that have been observed in the lower stratosphere in the absence of the relatively strong backscattering from homogeneous sulfuric acid droplet (beta equivalent to 0) or ice crystal (beta equivalent to 0.5) clouds.

  11. Standard guide for installing bonded resistance strain gages

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1993-01-01

    1.1 This guide provides guidelines for installing bonded resistance strain gages. It is not intended to be used for bulk or diffused semiconductor gages. This document pertains only to adhesively bonded strain gages. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  12. Streamflow gaging in a remote area using cellular telephone telemetry

    International Nuclear Information System (INIS)

    In this paper a case study is presented describing the utilization of cellular phone technology in a remote sensing situation. Because expected annual energy estimates are vital in planning small hydroelectric projects, it is important that the flow data from river gaging stations provide reliable information to the engineer. When the project is situated in a remote area where gaging stations are unavailable. such as on an island or in emerging nations, the design engineer may need to provide the flow data himself. The problem of transmitting the flow data from a remote mountain stream away from any roads and telephone lines, to the office for computer analysis was solved by using an innovative method utilizing cellular telephones to access raw data from solar powered data loggers and pressure transducer gaging instruments

  13. Damage detection by mixed measurements using accelerometers and strain gages

    International Nuclear Information System (INIS)

    This work investigates the relationship between the FRFs (frequency response functions) measured by accelerometers and strain gages utilized widely for investigating structural performance. Modifying the GDM (global-deviation method), this study examines the possibility of damage detection in utilizing both sensors together. The experimental results on the mixed utilization of two sensors show that the SFRF (strain frequency response function) data measured by strain gages in the neighborhood of end supports are more practical in establishing the baseline curve than the DFRF (displacement frequency response function) data measured by accelerometers. It is shown that the modified GDM can be effectively utilized in detecting damage based on the mixed measurements of accelerometers and strain gages. (paper)

  14. Evaluation of Pd-Cr Wires for Strain Gage Application

    Science.gov (United States)

    Lei, Jih-Fen; Greer, L. C., III; Oberle, L. G.

    1995-01-01

    A newly developed alloy, palladium-13 weight percent chromium (Pd13Cr), was identified by United Technologies Research Center under a NASA contract to be the best material for high temperature strain gage applications. An electrical resistance strain gage that can provide accurate static strain measurement to a temperature higher than that of a commercially available gage is urgently needed in aerospace and aeronautics research. A strain gage made of a 25.4 micron (1 mil) diameter Pd13Cr wire has been recently demonstrated to be usable for static strain measurements to 800 C. This compares to the 400 C temperature limit of the commercially available strain gages. The performance of the Pd-Cr gage, however, strongly depends on the quality of the Pd13Cr wire. Four batches of Pd-Cr wires purchased from three different manufacturers were therefore evaluated to determine the best source of the wire for strain gage applications. The three suppliers were Precious Metal Institute in China, Sigmund Cohn Co., and G & S Titanium, Inc. in the United States. Two batches of wires obtained from Previous Metal Institute in 1987 and 1992, respectively are referred to herein as China87 and China92 wires. The mechanical, chemical and electrical properties of these wires, both as-received and after high temperature exposures at 800 C for 50 hours were analyzed. The elastic modulus and the failure strength of the wires were evaluated using a tensile test machine equipped with a laser speckle strain measurement system. The chemical and microstructural properties of the wires were inspected using a plasma atomic emission spectrometer and a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscope (EDS). The electrical stability and repeatability of the wires were determined by measuring the electrical resistance of the wires during three thermal cycles to 1000 C and a ten-hour soak at 1000 C. As a result of this study, the wire which has the highest

  15. Development of a high temperature static strain gage system

    International Nuclear Information System (INIS)

    The objective of this program is to develop electrical resistance strain gages which will permit the measurement of static strains on nickel and cobalt superalloy parts inside gas turbine engines running on a test stand. The specific goal is to develop a complete system able to make strain measurements up to plus or minus 2000 mu strain with a total error of no more than plus or minus 10 percent over a 50 hour period at 1250 K. The initial part of this work consisted of a strain gage alloy development effort in which a variety of alloys were evaluated after being prepared by drop-casting or splat cooling

  16. Determination of residual stress profile using a strain gage technique

    International Nuclear Information System (INIS)

    A simple beam theory analysis is presented for the determination of residual stress patterns in beams or plates using a strain gage technique. The analysis is valid for a general stress distribution which need not be symmetric with respect to the neutral axis. The experimental approach consists of attaching a strain gage on the surface of a beam or a plate and then grinding off the other side. The recorded strain vs thickness ground off data can be used to determine the corresponding stress profile

  17. On line ultrasonic integrated backscatter

    International Nuclear Information System (INIS)

    A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

  18. Photoelectron backscattering in vacuum phototubes

    CERN Document Server

    Lubsandorzhiev, B K; Vyatchin, Y E; Shaibonov, B A J

    2006-01-01

    In this article we describe results of a photoelectron backscattering effect in vacuum phototubes: classical photomultipliers (PMT) and hybrid phototubes (PH). Late pulses occurring in PMTs are attributed to the photoelectron backscattering and distinguished from pulses due to an anode glow effect. The late pulses are measured in a number of PMTs and HPs with various photocathode sizes covering 1-50 cm range and different types of the first dynode materials and construction designs. It is shown that the late pulses are a generic feature of all vacuum photodetectors - PMTs and PHs and they don't deteriorate dramatically amplitude and timing responses of vacuum phototubes.

  19. USGS Small-scale Dataset - Streamflow Gaging Stations of the United States 201403 FileGDB 10.1

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer shows selected streamflow gaging stations of the United States, Puerto Rico, and the U.S. Virgin Islands, in 2013. Gaging stations, or gages, measure...

  20. ''Cristall'' gage for measuring manganese concentration and its exploitation at mining works

    International Nuclear Information System (INIS)

    A KM-1 ''Crystal'' gage for the rapid neutron activation analysis of ores and ore concentrates for manganese is described. The gage includes a container with (5x108 neutr/s) Pu-Be neutron source, sample feed mechanism, radiation detector, metering, controlling and blocking circuits. The gage permits to analyze raw manganese ore and ore concentrates within 5-55% manganese content ranges. Analysis accuracy is +-5% abs. The gage is simple in service. The calibration curve of the gage is given. Versions of the KM-1a ''Cristall'' gage described (for conditions of flotation concentrating mill) and KM-2 ''Cristall'' have been developed. The estimation of economic efficiency of the KM-2 ''Cristall'' gage has shown that annual benefit when using one gage was equal to 110000 roubles

  1. Polymer deformation gage measures thickness change in tensile tests

    Science.gov (United States)

    Broyles, H. F.; Broyles, H. H.

    1966-01-01

    Lightweight deformation gage attached to a polymer specimen determines the thickness changes undergone by the specimen during the testing of its tensile and elongation properties. Mechanical noise from outside sources is dampened when the assembly is hung on a light rubber band.

  2. Simplified atmospheric diffusion calculations with slide-rule gage points

    International Nuclear Information System (INIS)

    Gage points are given with the help of which the most commonly required atmospheric diffusion calculations can be carried out rapidly using a simple slide-rule setting; e.g. maximum ground concentration, its distance, and the corresponding effective stack height as functions of the prevailing type of meteorological condition. (author)

  3. X-ray backscatter imaging

    Science.gov (United States)

    Dinca, Dan-Cristian; Schubert, Jeffrey R.; Callerame, J.

    2008-04-01

    In contrast to transmission X-ray imaging systems where inspected objects must pass between source and detector, Compton backscatter imaging allows both the illuminating source as well as the X-ray detector to be on the same side of the target object, enabling the inspection to occur rapidly and in a wide variety of space-constrained situations. A Compton backscatter image is similar to a photograph of the contents of a closed container, taken through the container walls, and highlights low atomic number materials such as explosives, drugs, and alcohol, which appear as especially bright objects by virtue of their scattering characteristics. Techniques for producing X-ray images based on Compton scattering will be discussed, along with examples of how these systems are used for both novel security applications and for the detection of contraband materials at ports and borders. Differences between transmission and backscatter images will also be highlighted. In addition, tradeoffs between Compton backscatter image quality and scan speed, effective penetration, and X-ray source specifications will be discussed.

  4. Gravitational Laser Back-Scattering

    OpenAIRE

    Novaes, S. F.; Spehler, D.

    1993-01-01

    A possible way of producing gravitons in the laboratory is investigated. We evaluate the cross section electron + photon $\\rightarrow$ electron + graviton in the framework of linearized gravitation, and analyse this reaction considering the photon coming either from a laser beam or from a Compton back-scattering process.

  5. Analytical purpose electron backscattering system

    International Nuclear Information System (INIS)

    In this work an analytical purposes electron backscattering system improved at the Center of Applied Studies for Nuclear Development is described. This system can be applied for fast, exact and nondestructive testing of binary and AL/Cu, AL/Ni in alloys and for other applications

  6. Evaluation of candidate rain gages for upgrading precipitation measurement tools for the National Atmospheric Deposition Program

    Science.gov (United States)

    Gordon, John D.

    2003-01-01

    The National Atmospheric Deposition Program (NADP) was established in 1977 to investigate atmospheric deposition and its effects on the environment. Since its establishment, precipitation records have been obtained at all NADP sites using a gage developed approximately 50 years ago-the Belfort 5-780 mechanical rain gage. In 1998 and 1999, a study was done by the U.S. Geological Survey to evaluate four recently developed, technologically advanced rain gages as possible replacement candidates for the mechanical gage currently (2002) in use by the NADP. The gage types evaluated were the Belfort 3200, Geonor T-200, ETI Noah II, and the OTT PLUVIO. The Belfort 5-780 was included in the study to compare the performance of the rain gage currently (2002) used by NADP to the performance of the more recently developed gages. As a reference gage, the NovaLynx Model 260-2510 National Weather Service type stick gage also was included in the study. Two individual gages of each type were included in the study to evaluate precision between gages of the same type. A two-phase evaluation was completed. Phase I consisted of indoor bench tests with known amounts of simulated rainfall applied in 20 individual tests. Phase II consisted of outdoor testing by collecting precipitation during a 26-week period near Bay St. Louis, Mississippi. The ETI Noah II, OTT PLUVIO, and NovaLynx stick gages consistently recorded depths more commensurate with the amounts of applied simulated rainfall in Phase I testing than the Geonor T-200, Belfort 5-780, and Belfort 3200 gages. Gages where both the median difference between the measured and applied simulated rainfall and the interquartile range of all of their measured minus applied simulated rainfall differences were small (less than or equal to 0.01 inch) were judged to have performed very well in Phase I testing. The median and interquartile-range values were 0.01 inch or less for each of the ETI Noah II gages, OTT PLUVIO gages, and NovaLynx stick

  7. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  8. Using Gage Blocks as Measuring Standards, Aviation Quality Control (Basic): 9225.03.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This unit of instruction deals with a study of the evolution and history of gage blocks and optical flats as measuring tools. Theory and principles are covered in detail. Considerable time is spent on the techniques of using gage blocks and optical flats in actual measurement set-ups. Included is the calibration and care of gage blocks and optical…

  9. BackscatterA [8101]--Offshore Pacifica, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Pacifica map area, California. Backscatter data are provided as two separate grids...

  10. Backscatter B [8101]--Offshore Bolinas, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bolinas map area, California. Backscatter data are provided as separate grids...

  11. Backscatter D [Snippets]--Offshore Bolinas, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bolinas map area, California. Backscatter data are provided as separate grids...

  12. BackscatterB [7125]--Offshore Pacifica, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Pacifica map area, California. Backscatter data are provided as two separate grids...

  13. Backscatter A [8101]--Offshore Bolinas, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bolinas map area, California. Backscatter data are provided as separate grids...

  14. Backscatter A [8101]--Offshore San Gregorio, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3306 presents data for the acoustic-backscatter map (see sheet 3, SIM 3306) of the Offshore of San Gregorio map area, California. Backscatter data...

  15. Backscatter E [Swath]--Offshore Bolinas, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bolinas map area, California. Backscatter data are provided as separate grids...

  16. Backscatter [SWATH]--Offshore Santa Cruz, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Santa Cruz map area, California. Backscatter data are provided as three separate...

  17. Backscatter B [7125]--Offshore San Gregorio, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3306 presents data for the acoustic-backscatter map (see sheet 3, SIM 3306) of the Offshore of San Gregorio map area, California. Backscatter data...

  18. Nodule bottom backscattering study using multibeam echosounder

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Raju, Y.S.N.; Nair, R.R.

    A study is carried out to observe the angular dependence of backscattering strength at nodule area where grab sample and photographic data is available. Theoretical study along with the experimentally observed data shows that the backscattering...

  19. Backscatter C [7125]--Offshore Bolinas, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bolinas map area, California. Backscatter data are provided as separate grids...

  20. Alumina Encapsulated Strain Gage Not Mechanically Attached To The Substrate, Used to Temperature Compensate an Active High Temperature Gage In A Half-Bridge Configuration

    Science.gov (United States)

    Piazza, Anthony (Inventor)

    2001-01-01

    A temperature compensation element for a high-temperature strain gage and the method of fabricating the same. Preferably, the element is a "dummy" strain gage not mechanically attached to the substrate. The element is encapsulated in an insulative material and used to compensate an active high-temperature strain gage and wired in a half-bridge configuration. The temperature compensation element and high-temperature strain gage are fabricated using the method of the present invention. This method includes temporarily adhering the element to a heat sink, encapsulated in an insulative material and then removed from the heat sink. Next, the element is either stacked or placed near the active gage. Ideally, the element and the active gage have substantially similar heat transfer and electrical properties.

  1. Analysis of strain gage reliability in F-100 jet engine testing at NASA Lewis Research Center

    Science.gov (United States)

    Holanda, R.

    1983-01-01

    A reliability analysis was performed on 64 strain gage systems mounted on the 3 rotor stages of the fan of a YF-100 engine. The strain gages were used in a 65 hour fan flutter research program which included about 5 hours of blade flutter. The analysis was part of a reliability improvement program. Eighty-four percent of the strain gages survived the test and performed satisfactorily. A post test analysis determined most failure causes. Five failures were caused by open circuits, three failed gages showed elevated circuit resistance, and one gage circuit was grounded. One failure was undetermined.

  2. Improvements in backscatter measurement devices

    International Nuclear Information System (INIS)

    Improvements in measuring the thickness of a coating on a substrate by the technique of backscattered particles are described. These improvements enable the measurements to be carried out continuously as an integral part of the coating production line and also permit measurements where the coated elements are separated from one another by a predetermined distance. The former is achieved by situating the backscatter probe and detector on the rim of the measurement wheel and rotating this wheel at a speed such that the coated element and probe are stationary relative to one another. The latter improvement is achieved by an indexing apparatus which automatically positions the probe beside a coated element. (U.K.)

  3. Hanle effect in coherent backscattering

    International Nuclear Information System (INIS)

    We study the shape of the coherent-backscattering (CBS) cone obtained when resonant light illuminates a thick cloud of laser-cooled rubidium atoms in the presence of a homogenous magnetic field. We observe new magnetic field-dependent anisotropies in the CBS signal. We show that the observed behavior is due to the modification of the atomic-radiation pattern by the magnetic field (Hanle effect in the excited state)

  4. Standard test method for ambient temperature fatigue life of metallic bonded resistance strain gages

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This test method covers a uniform procedure for the determination of strain gage fatigue life at ambient temperature. A suggested testing equipment design is included. 1.2 This test method does not apply to force transducers or extensometers that use bonded resistance strain gages as sensing elements. 1.3 Strain gages are part of a complex system that includes structure, adhesive, gage, leadwires, instrumentation, and (often) environmental protection. As a result, many things affect the performance of strain gages, including user technique. A further complication is that strain gages, once installed, normally cannot be reinstalled in another location. Therefore, it is not possible to calibrate individual strain gages; performance characteristics are normally presented on a statistical basis. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices ...

  5. Strain-gage applications in wind tunnel balances

    Science.gov (United States)

    Mole, P. J.

    1990-10-01

    Six-component balances used in wind tunnels for precision measurements of air loads on scale models of aircraft and missiles are reviewed. A beam moment-type balance, two-shell balance consisting of an outer shell and inner rod, and air-flow balances used in STOL aircraft configurations are described. The design process, fabrication, gaging, single-gage procedure, and calibration of balances are outlined, and emphasis is placed on computer stress programs and data-reduction computer programs. It is pointed out that these wind-tunnel balances are used in applications for full-scale flight vehicles. Attention is given to a standard two-shell booster balance and an adaptation of a wind-tunnel balance employed to measure the simulated distributed launch loads of a payload in the Space Shuttle.

  6. Cost-effectiveness of the U.S. Geological Survey stream-gaging program in Indiana

    Science.gov (United States)

    Stewart, J.A.; Miller, R.L.; Butch, G.K.

    1986-01-01

    Analysis of the stream gaging program in Indiana was divided into three phases. The first phase involved collecting information concerning the data need and the funding source for each of the 173 surface water stations in Indiana. The second phase used alternate methods to produce streamflow records at selected sites. Statistical models were used to generate stream flow data for three gaging stations. In addition, flow routing models were used at two of the sites. Daily discharges produced from models did not meet the established accuracy criteria and, therefore, these methods should not replace stream gaging procedures at those gaging stations. The third phase of the study determined the uncertainty of the rating and the error at individual gaging stations, and optimized travel routes and frequency of visits to gaging stations. The annual budget, in 1983 dollars, for operating the stream gaging program in Indiana is $823,000. The average standard error of instantaneous discharge for all continuous record gaging stations is 25.3%. A budget of $800,000 could maintain this level of accuracy if stream gaging stations were visited according to phase III results. A minimum budget of $790,000 is required to operate the gaging network. At this budget, the average standard error of instantaneous discharge would be 27.7%. A maximum budget of $1 ,000,000 was simulated in the analysis and the average standard error of instantaneous discharge was reduced to 16.8%. (Author 's abstract)

  7. Cost effectiveness of the US Geological Survey's stream-gaging program in New York

    Science.gov (United States)

    Wolcott, S.W.; Gannon, W.B.; Johnston, W.H.

    1986-01-01

    The U.S. Geological Survey conducted a 5-year nationwide analysis to define and document the most cost effective means of obtaining streamflow data. This report describes the stream gaging network in New York and documents the cost effectiveness of its operation; it also identifies data uses and funding sources for the 174 continuous-record stream gages currently operated (1983). Those gages as well as 189 crest-stage, stage-only, and groundwater gages are operated with a budget of $1.068 million. One gaging station was identified as having insufficient reason for continuous operation and was converted to a crest-stage gage. Current operation of the 363-station program requires a budget of $1.068 million/yr. The average standard error of estimation of continuous streamflow data is 13.4%. Results indicate that this degree of accuracy could be maintained with a budget of approximately $1.006 million if the gaging resources were redistributed among the gages. The average standard error for 174 stations was calculated for five hypothetical budgets. A minimum budget of $970,000 would be needed to operated the 363-gage program; a budget less than this does not permit proper servicing and maintenance of the gages and recorders. Under the restrictions of a minimum budget, the average standard error would be 16.0%. The maximum budget analyzed was $1.2 million, which would decrease the average standard error to 9.4%. (Author 's abstract)

  8. Beta Thalassemia

    Science.gov (United States)

    ... South Asian (Indian, Pakistani, etc.), Southeast Asian and Chinese descent. 1 Beta Thalassemia ßß Normal beta globin ... then there is a 25% chance with each pregnancy that their child will inherit two abnormal beta ...

  9. Conductance and noise signatures of Majorana backscattering

    OpenAIRE

    Chung, Suk Bum; Qi, Xiao-Liang; Maciejko, Joseph; Zhang, Shou-Cheng

    2010-01-01

    We propose a conductance measurement to detect the backscattering of chiral Majorana edge states. Because normal and Andreev processes have equal probability for backscattering of a single chiral Majorana edge state, there is qualitative difference from backscattering of a chiral Dirac edge state, giving rise to half-integer Hall conductivity and decoupling of fluctuation in incoming and outgoing modes. The latter can be detected through thermal noise measurement. These experimental signature...

  10. Signal conditioning of single-active-arm strain gages used for dynamic stress measurement

    Science.gov (United States)

    Mahrenholz, B. G.

    1991-09-01

    A new strain-gage signal conditioner is described for use in the measurement of dynamic stresses on turbine engine compressor blades. This conditioner has two novel circuits. A new gage excitation circuit corrects for changes in lead-wire resistance by automatically adjusting resistances in series with the leads to the gage. This maintains a balanced configuration that offers better high-frequency common-mode rejection and less broadband noise than with constant-current excitation. Another circuit in the conditioner provides system calibration by shunting a small value resistor that is in series with the gage to produce resistance change that accurately simulates the gage resistance change. The shunting is done at a rate of 1,000 times a second to produce a 1-kHz square-wave calibration signal. The calibration circuit may be used to check on the integrity of the gage and its cabling.

  11. Palladium-chromium static strain gage for high temperature propulsion systems

    Science.gov (United States)

    Lei, Jih-Fen

    1991-01-01

    The present electrical strain gage for high temperature static strain measurements is in its fine-wire and thin-film forms designed to be temperature-compensated on any substrate material. The gage element is of Pd-Cr alloy, while the compensator is of Pt. Because the thermally-induced apparent strain of this compensated wire strain gage is sufficiently small, with good reproducibility between thermal cycles to 800 C, output figures can be corrected within a reasonable margin of error.

  12. Strain Gage Measurement System to Determine Cryogenic Propellant Tank Level

    Science.gov (United States)

    Figueroa, Fernando; St.Cyr, William W.; VanDyke, David; McVay, Greg; Mitchell, Mark; Langford, Lester

    2003-01-01

    Measurement of tank level, particularly for cryogenic propellants, has proven to be a difficult proposition. Current methods based on differential pressure, capacitance sensors, temperature sensors, etc.; do not provide sufficiently accurate or robust measurements, especially at run time. This paper describes a simple, but effective method to determine propellant volume by measuring very small deformations of the structure supporting the tank. Results of a laboratory study to validate the method, and experimental data from a deployed system are presented. A comparison with an existing differential pressure sensor shows that the strain gage system provides a very good quality signal even during pressurization.

  13. Alfred P. Gage and the Introductory Physics Laboratory

    Science.gov (United States)

    Greenslade, Thomas B.

    2016-03-01

    This article is about a late 19th-century teacher of secondary school physics. I was originally interested in the apparatus that he sold. This led me to the physics books that he wrote, and these took me to his unusual ideas about ways to use laboratory time to introduce students to the phenomena of physics. More than 100 years later educational ideas have now come full circle, and it is time to bring Gage and his texts and ideas to 21st-century physics teachers.

  14. Zero-Gravity Vortex Vent and PVT Gaging System

    Science.gov (United States)

    Downey, M. G.; Trevathan, J. T.

    1989-01-01

    Space Station and satellite reservicing will require the ability to vent gas on orbit from liquid supply or storage tanks and to gage liquid quantity under microgravity conditions. In zero gravity, (zero-g) the vortex vent is capable of venting gas from a tank of liquid containing gas randomly distributed as bubbles. The concept uses a spinning impeller to create centrifugal force inside a vortex tube within a tank. This creates a gas pocket and forces the liquid through a venturi and back into the tank. Gas is then vented from the gas pocket through a liquid detector and then out through an exhaust port. If the liquid detector senses liquid in the vent line, the fluid is directed to the low-pressure port on the venturi and is returned to the tank. The advantages of this system is that it has no rotating seals and is compatible with most corrosive and cryogenic fluids. A prototype was designed and built at the NASA Johnson Space Center and flown on the KC-135 zero-g aircraft. During these test flights, where microgravity conditions are obtained for up to 30 sec, the prototype demonstrated that less than 0.10 percent of the volume of fluid vented was liquid when the tank was half full of liquid. The pressure volume temperature (PVT) gaging system is used in conjunction with the vortex vent to calculate the amount of liquid remaining in a tank under microgravity conditions. The PVT gaging system is used in conjunction with the vortex vent to gage liquid quantity in zero or low gravity. The system consists of a gas compressor, accumulator, and temperature and pressure instrumentation. To measure the liquid in a tank a small amount of gas is vented from the tank to the compressor and compressed into the accumulator. Pressure and temperature in the tank and accumulator are measured before and after the gas transfer occurs. Knowing the total volume of the tank, the volume of the accumulator, the volume of the intermediate lines, and initial and final pressures and

  15. Experimental spectra unfolding of fast ion backscattering

    International Nuclear Information System (INIS)

    Problems on processing of experimental spectra of fast light ion backscattering are considered to obtain information about element composition in thin films and surface layers of solids. Application of mathematical processing of the spectra is shown to allow considerably to improve analytical characteristics of the ion backscattering method and to expand the field for its application

  16. Apparatus for storage, retrieval and deployment of drag gages used in fuel assembly inspection

    International Nuclear Information System (INIS)

    In a fuel assembly guide thimble inspecting system having drag gages being insertable within guide thimbles of a fuel assembly, a drag gage handling apparatus is described comprising: (a) storing means for holding the drag gages in a series of storage positions being angularly displaced from one another about a common axis; (b) means for moving the drag gages from the respective storage positions about an endless path to dispose a selected one of the gages at a retrieval-and-return station; (c) loading means operable for respectively gripping and releasing the selected one drag gage at the retrieval-and-return station; (d) transporting means movable between a work station and a storage station; (e) hoisting means supporting the loading means and being supported by the transporting means, the hoisting means being operable for respectively raising and lowering the loading means and the selected one drag gage therewith away from and toward the retrieval-and-return station when the transporting means is at the storage station and operable for respectively raising and lowering the loading means and the selected one drag gage away from and toward the fuel assembly guide thimbles when the transporting means is at the work station; (f) safety means releasably mounted to the loading means for restraining the loading means in gripping relation with the selected one drag gage; and (g) means located adjacent to the retrieval-and-return station for releasing the safety means from restraining the loading means in gripping relation with the selected one drag gage only when the loading means and selected one drag gage are disposed at the retrieval-and-return station

  17. Use of encapsulated high-temperature strain gages at temperatures up to 315 C

    International Nuclear Information System (INIS)

    An account is given of the use of two types of encapsulated strain gage to measure strains in West Germany nuclear power stations during start up and service. Gage calibration was performed using a clamping device rather than spot welding. Of the two types of encapsulated strain gages available for measurement up to 315 C, one is a quarter-bridge gage with an NiCr measuring element; the other is a half-bridge gage with a PtW measuring element. Factors considered were: apparent strain, zero shift, change of apparent strain, creep and lifetime. It is recommended that NiCr gages be used for static measurements up to about 260 C only. For temperatures higher than 260 degrees, PtW strain gages must be used; these seem to be much more stable at temperatures of 260-315 C. Tests are under way to determine the maximum temperature for these gages; all that is certain now is that they fail at 530 C when the cables separate. 6 references

  18. Cost effectiveness of the US Geological Survey's stream-gaging programs in New Hampshire and Vermont

    Science.gov (United States)

    Smath, J.A.; Blackey, F.E.

    1986-01-01

    Data uses and funding sources were identified for the 73 continuous stream gages currently (1984) being operated. Eight stream gages were identified as having insufficient reason to continue their operation. Parts of New Hampshire and Vermont were identified as needing additional hydrologic data. New gages should be established in these regions as funds become available. Alternative methods for providing hydrologic data at the stream gaging stations currently being operated were found to lack the accuracy that is required for their intended use. The current policy for operation of the stream gages requires a net budget of $297,000/yr. The average standard error of estimation of the streamflow records is 17.9%. This overall level of accuracy could be maintained with a budget of $285,000 if resources were redistributed among gages. Cost-effective analysis indicates that with the present budget, the average standard error could be reduced to 16.6%. A minimum budget of $278,000 is required to operate the present stream gaging program. Below this level, the gages and recorders would not receive the proper service and maintenance. At the minimum budget, the average standard error would be 20.4%. The loss of correlative data is a significant component of the error in streamflow records, especially at lower budgetary levels. (Author 's abstract)

  19. Detector for high-energy photon backscatter

    Science.gov (United States)

    Silver, Michael D.; Erker, Joseph W.; Duncan, Michael Z.; Hartford, Thomas J.; Sivers, E. A.; Hopkinson, James F.

    1993-12-01

    High energy photon backscatter uses pair production to probe deep beneath surfaces with single side accessibility or to image thick, radiographically opaque objects. At the higher photon energies needed to penetrate thick and/or highly attenuating objects, Compton backscatter becomes strongly forward peaked with relatively little backscatter flux. Furthermore, the downward energy shift of the backscattered photon makes it more susceptible to attenuation on its outbound path. Above 1.022 MeV, pair production is possible; at about 10 MeV, pari production crosses over Compton scatter as the dominant x-ray interaction mechanism. The backscattered photons can be hard x rays from the bremsstrahlung of the electrons and positrons or 0.511 MeV photons from the annihilation of the positron. Monte Carlo computer simulations of such a backscatter system were done to characterize the output signals and to optimize a high energy detector design. This paper touches on the physics of high energy backscatter imaging and describes at some length the detector design for tomographic and radiographic imaging.

  20. Application of hybrid techniques (self-organizing map and fuzzy algorithm) using backscatter data for segmentation and fine-scale roughness characterization of seepage-related seafloor along the western continental margin of India

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Menezes, A.A.A.; Dandapath, S.; Fernandes, W.A.; Karisiddaiah, S.M.; Haris, K.; Gokul, G.S.

    backscatter data facilitates in achieving stationary profile data sets suitable for seafloor roughness model application. The power spectral density (PSD) function of the segmented profiles provides the power law parameters (Beta and a`) through curve fitting...

  1. Harvesting backscatter electrons for radiation therapy

    International Nuclear Information System (INIS)

    Purpose: An innovative technique is used to harvest backscatter electrons for the treatment of superficial small lesions of skin, oral cavity, and rectum where a significant dose gradient and maximum surface dose is desired. Methods and Materials: Backscatter electrons are harvested out of the primary electron beams from the linear accelerators. The design consists of a short cylindrical cone that fits snugly over a long cylindrical electron cone. The short cylindrical cone has a thick circular plate of high atomic number medium (Pb) attached to the distal end, and a lateral slit of variable length and width. The width of the slit could be closed as desired by rotating the two cones and the length can be increased by lowering the short cylindrical cone. Primary electrons strike the Pb plate perpendicularly and produce backscatter electrons that pass through the lateral slit for treatment. Using film and a parallel plate ion chamber, backscattered electron dose characteristics are studied. Results: The depth dose characteristic of the backscatter electron is very similar to that of the 0.2 mm Al half-value layer x-ray beam that is commonly used for the intracavitary and superficial lesions. The backscatter electron energy is nearly constant and effectively ≤ 1 MeV from the clinical megavoltage beams. The backscatter electron dose rate of 0.32-0.8 Gy/min could be achieved from modern accelerators without any modification. The beam flatness is dependent on the slit size and the depth of treatment, but is satisfactory to treat small lesions. Conclusions: The measured data for backscatter electron energy, fluence, depth dose, flatness, dose rate, and absolute dose indicates that the harvested backscattered electrons are suitable for clinical use

  2. Cost effectiveness of the U.S. Geological Survey's stream-gaging program in Illinois

    Science.gov (United States)

    Mades, D.M.; Oberg, K.A.

    1984-01-01

    Data uses and funding sources were identified for 138 continuous-record discharge-gaging stations currently (1983) operated as part of the stream-gaging program in Illinois. Streamflow data from five of those stations are used only for regional hydrology studies. Most streamflow data are used for defining regional hydrology, defining rainfall-runoff relations, flood forecasting, regulating navigation systems, and water-quality sampling. Based on the evaluations of data use and of alternative methods for determining streamflow in place of stream gaging, no stations in the 1983 stream-gaging program should be deactivated. The current budget (in 1983 dollars) for operating the 138-station program is $768,000 per year. The average standard error of instantaneous discharge for the current practice for visiting the gaging stations is 36.5 percent. Missing stage record accounts for one-third of the 36.5 percent average standard error. (USGS)

  3. Influence of Primary Gage Sensitivities on the Convergence of Balance Load Iterations

    Science.gov (United States)

    Ulbrich, Norbert Manfred

    2012-01-01

    The connection between the convergence of wind tunnel balance load iterations and the existence of the primary gage sensitivities of a balance is discussed. First, basic elements of two load iteration equations that the iterative method uses in combination with results of a calibration data analysis for the prediction of balance loads are reviewed. Then, the connection between the primary gage sensitivities, the load format, the gage output format, and the convergence characteristics of the load iteration equation choices is investigated. A new criterion is also introduced that may be used to objectively determine if the primary gage sensitivity of a balance gage exists. Then, it is shown that both load iteration equations will converge as long as a suitable regression model is used for the analysis of the balance calibration data, the combined influence of non linear terms of the regression model is very small, and the primary gage sensitivities of all balance gages exist. The last requirement is fulfilled, e.g., if force balance calibration data is analyzed in force balance format. Finally, it is demonstrated that only one of the two load iteration equation choices, i.e., the iteration equation used by the primary load iteration method, converges if one or more primary gage sensitivities are missing. This situation may occur, e.g., if force balance calibration data is analyzed in direct read format using the original gage outputs. Data from the calibration of a six component force balance is used to illustrate the connection between the convergence of the load iteration equation choices and the existence of the primary gage sensitivities.

  4. Strain gage sting balance 204-6. Calibration report

    Science.gov (United States)

    Blaettler, Heinz

    1986-12-01

    The strain gage sting balance 204-6 was developed for aerodynamic measurements on rocket models in the transonic and supersonic wind tunnel. Data are: X = +/- 50 (N); Y = +/- 150 (N); Z = +/- 400 (N); Mx = +/- 1.5 (Nm); My = +/- 20 (Nm); and Mz = +/- 10 (Nm). Compared to the existing balances of same size the ratio Y/Z is changed from 1:8 to 1:3.75. This change of specifications was introduced with regard to measurements to be taken with a sting providing automatic roll positioning around the X-axis. The resistance module was separately constructed and prestressed by a factor of 0.5, and connected to the model and sting part of the balance by electron-beam welding.

  5. An evaluation of Idaho stream-gaging networks

    Science.gov (United States)

    Quillian, E.W.; Harenberg, W.A.

    1982-01-01

    Network Analysis for Regional Information (NARI) and the Cost-Effectiveness Procedure were tested by applying them to stream-gaging networks in Idaho. NARI was used to determine network design strategies that would maximize the value of additional data. Value of data was measured as the decrease in the probable true standards error of regional regression equations. NARI indicated that no significant decrease in regression error can be achieved by the collection of additional data and that better models should be sought. No major modifications to NARI are necessary to make it widely applicable. The Cost-Effectiveness Procedure was used to determine optimal network operation strategies. It showed network uncertainty can be reduced when six- or one-visit per year minimum constraints are in force. Sensitivity to various cost factors was examined. Attempts to model networks that included sites for collection of groundwater and water-quality data were unsuccessful. (USGS)

  6. Geoscience Workforce Development at UNAVCO: Leveraging the NSF GAGE Facility

    Science.gov (United States)

    Morris, A. R.; Charlevoix, D. J.; Miller, M.

    2013-12-01

    Global economic development demands that the United States remain competitive in the STEM fields, and developing a forward-looking and well-trained geoscience workforce is imperative. According to the Bureau of Labor Statistics, the geosciences will experience a growth of 19% by 2016. Fifty percent of the current geoscience workforce is within 10-15 years of retirement, and as a result, the U.S. is facing a gap between the supply of prepared geoscientists and the demand for well-trained labor. Barring aggressive intervention, the imbalance in the geoscience workforce will continue to grow, leaving the increased demand unmet. UNAVCO, Inc. is well situated to prepare undergraduate students for placement in geoscience technical positions and advanced graduate study. UNAVCO is a university-governed consortium facilitating research and education in the geosciences and in addition UNAVCO manages the NSF Geodesy Advancing Geosciences and EarthScope (GAGE) facility. The GAGE facility supports many facets of geoscience research including instrumentation and infrastructure, data analysis, cyberinfrastructure, and broader impacts. UNAVCO supports the Research Experiences in the Solid Earth Sciences for Students (RESESS), an NSF-funded multiyear geoscience research internship, community support, and professional development program. The primary goal of the RESESS program is to increase the number of historically underrepresented students entering graduate school in the geosciences. RESESS has met with high success in the first 9 years of the program, as more than 75% of RESESS alumni are currently in Master's and PhD programs across the U.S. Building upon the successes of RESESS, UNAVCO is launching a comprehensive workforce development program that will network underrepresented groups in the geosciences to research and opportunities throughout the geosciences. This presentation will focus on the successes of the RESESS program and plans to expand on this success with broader

  7. Instrument for underwater measurement of optical backscatter

    Science.gov (United States)

    Maffione, Robert A.; Dana, David R.; Honey, Richard C.

    1991-12-01

    A backscatter sensor has been developed for rapidly measuring, in situ, the volume scattering function (VSF) in the backward direction. The backscatter sensor uses a bistatic optical geometry to measure backscatter from a small volume of seawater over a range of scattering angles from approximately 115 degree(s) to 170 degree(s). The calibration of the sensor yields a weighted, angular averaged value of the VSF with a centroid located at a scattering angle of about 150 degree(s). The backscatter sensor design is based on a sensitive synchronous detector and pulsed, light-emitting diode that has been used at visible and near-infrared wavelengths. The entire sensor package, which includes circuitry for digitizing the signal, is contained in a compact, rugged housing. The sensor has been deployed both in towed arrays and in stationary profiling mode. Scattering profiles from two recent deployments are presented.

  8. Stimulated Raman backscattering at high laser intensities

    Energy Technology Data Exchange (ETDEWEB)

    Skoric, M.M. [Vinca Inst. of Nuclear Sciences, Belgrade (Yugoslavia); Tajima, Toshiki; Sasaki, Akira; Maluckov, A.; Jovanovic, M.

    1998-03-01

    Signatures of Stimulated Raman backscattering of a short-pulse high-intensity laser interacting with an underdense plasma are discussed. We introduce a nonlinear three-wave interaction model that accounts for laser pump depletion and relativistic detuning. A mechanism is revealed based on a generic route to chaos, that predicts a progressive increase of the backscatter complexity with a growing laser intensity. Importance of kinetic effects is outlined and demonstrated in fluid-hybrid and particle simulations. As an application, we show that spectral anomalies of the backscatter, predicted by the above model, are consistent with recent sub-picosecond, high-intensity laser gas-target measurements at Livermore and elsewhere. Finally, a recently proposed scheme for generation of ultra-short, low-prepulse laser pulses by Raman backscattering in a thin foil target, is shown. (author)

  9. Steel strain gage on steel shaft liner: Installation and monitoring procedure: Final draft

    International Nuclear Information System (INIS)

    Tangential and axial strains will be measured in the steel shaft liner component using steel strain gages (SSGs). These gages are vibrating wire strain gages welded directly to the steel liner. The primary objective of the overall monitoring program of which these gages constitute one part, is to define the stress-deformation behavior of the linings, seals, and foundations during and after construction. For this purpose, it is necessary to consider the SSGs welded to the liners as one element of an integrated program of monitoring the mechanical and thermomechanical response of the shaft. Other instruments which form part of this program include extensometers, concrete strain gages, convergence gages, concrete stress gages, piezometers, joint meters, and temperature detectors. The selection of these instrument types and their locations is based on a unified concept of behavior of the lining/rock structure and on how such a model of behavior will be deduced from the results of all instrumentation at an array. 9 refs., 5 figs

  10. Backscatter Modeling at 2.1 Micron Wavelength for Space-Based and Airborne Lidars Using Aerosol Physico-Chemical and Lidar Datasets

    Science.gov (United States)

    Srivastava, V.; Rothermel, J.; Jarzembski, M. A.; Clarke, A. D.; Cutten, D. R.; Bowdle, D. A.; Spinhirne, J. D.; Menzies, R. T.

    1999-01-01

    Space-based and airborne coherent Doppler lidars designed for measuring global tropospheric wind profiles in cloud-free air rely on backscatter, beta from aerosols acting as passive wind tracers. Aerosol beta distribution in the vertical can vary over as much as 5-6 orders of magnitude. Thus, the design of a wave length-specific, space-borne or airborne lidar must account for the magnitude of 8 in the region or features of interest. The SPAce Readiness Coherent Lidar Experiment under development by the National Aeronautics and Space Administration (NASA) and scheduled for launch on the Space Shuttle in 2001, will demonstrate wind measurements from space using a solid-state 2 micrometer coherent Doppler lidar. Consequently, there is a critical need to understand variability of aerosol beta at 2.1 micrometers, to evaluate signal detection under varying aerosol loading conditions. Although few direct measurements of beta at 2.1 micrometers exist, extensive datasets, including climatologies in widely-separated locations, do exist for other wavelengths based on CO2 and Nd:YAG lidars. Datasets also exist for the associated microphysical and chemical properties. An example of a multi-parametric dataset is that of the NASA GLObal Backscatter Experiment (GLOBE) in 1990 in which aerosol chemistry and size distributions were measured concurrently with multi-wavelength lidar backscatter observations. More recently, continuous-wave (CW) lidar backscatter measurements at mid-infrared wavelengths have been made during the Multicenter Airborne Coherent Atmospheric Wind Sensor (MACAWS) experiment in 1995. Using Lorenz-Mie theory, these datasets have been used to develop a method to convert lidar backscatter to the 2.1 micrometer wavelength. This paper presents comparison of modeled backscatter at wavelengths for which backscatter measurements exist including converted beta (sub 2.1).

  11. High-Temperature Extensometry and PdCr Temperature-Compensated Wire Resistance Strain Gages Compared

    Science.gov (United States)

    1997-01-01

    A detailed experimental evaluation is underway at the NASA Lewis Research Center to compare and contrast the performance of the PdCr/Pt dual-element temperature-compensated wire resistance strain gage with that of conventional high-temperature extensometry. The advanced PdCr gage, developed by researchers at Lewis, exhibits desirable properties and a relatively small and repeatable apparent strain to 800 C. This gage represents a significant advance in technology because existing commercial resistance strain gages are not reliable for quasi-static strain measurements above approx. 400 C. Various thermal and mechanical loading spectra are being applied by a high-temperature thermomechanical uniaxial testing system to evaluate the two strain-measurement systems. This is being done not only to compare and contrast the two strain sensors, but also to investigate the applicability of the PdCr strain gage to the coupon-level specimen testing environment typically employed when the high-temperature mechanical behavior of structural materials is characterized. Strain measurement capabilities to 800 C are being investigated with a nickel-base superalloy, Inconel 100 (IN 100), substrate material and application to TMC's is being examined with the model system, SCS-6/Ti-15-3. Furthermore, two gage application techniques are being investigated in the comparison study: namely, flame-sprayed and spot welding. The apparent strain responses of both the weldable and flame-sprayed PdCr wire strain gages were found to be cyclically repeatable on both IN 100 and SCS-6/Ti-15-3 [0]_8. In general, each gage exhibited some uniqueness with respect to apparent strain behavior. Gages mounted on the IN 100 specimens tended to show a repeatable apparent strain within the first few cycles, because the thermal response of IN 100 was stable. This was not the case, however, for the TMC specimens, which typically required several thermal cycles to stabilize the thermal strain response. Thus

  12. Cost effectiveness of the U.S. Geological Survey's stream-gaging program in Wisconsin

    Science.gov (United States)

    Walker, J.F.; Osen, L.L.; Hughes, P.E.

    1987-01-01

    This report presents the results of a three-step evaluation of the stream-gaging program in Wisconsin. First, data uses and funding sources were identified for the 89 continuous-record gaging stations operated during the 1984 water year. Next, alternative methods of streamflow estimation were examined for three stations. A flow-routing model was used for two of the stations and a statistical model was used for the third. The modeled discharges did not compare well enough with observed discharges to warrant elimination of any of the stations. Finally, an optimization model was used to assess the cost effectiveness of the stream-gaging process.

  13. Flow and gage monitoring records for Stillwater National Wildlife Refuge : 2002

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This file contains records of a survey of water flow, depth of water in the canal or unit gage height, and other comments, through selected points in the drainage...

  14. U.S. Geological Survey Stream Gages located in the Central Valley, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the locations of, and links to USGS gages on the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central...

  15. Drainage basin delineations for selected USGS streamflow-gaging stations in Virginia (Drainage_Basin)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Drainage_Basin polygon feature class was created as a digital representation of drainage basins for more than 1,650 continuous-record streamflow-gaging...

  16. Problems Associated with Attaching Strain Gages to Titanium Alloy Ti-61-4V

    Science.gov (United States)

    Jenkins, J. M.; Lemcoe, M. M.

    1977-01-01

    Weldable strain gages have shown excellent high temperature characteristics for supersonic cruise aircraft application. The spotwelding attachment method, however, has resulted in serious reductions in the fatigue life of titanium alloy (Ti-6Al-4V) fatigue specimens. The reduction is so severe that the use of weldable strain gages on operational aircraft must be prohibited. The cause of the fatigue problem is thought to be a combination of the microstructure changes in the material caused by spotwelding and the presence of the flange of the stain gage. Brazing, plating, and plasma spraying were investigated as substitutes for spotwelding. The attachment of a flangeless gage by plasma spraying provided the most improvement in the fatigue life of the titanium.

  17. Flow and gage monitoring records for Stillwater National Wildlife Refuge : 1997

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This file contains records of a survey of water flow, depth of water in the canal or unit gage height, and other comments, through selected points in the drainage...

  18. Technical manual, data reduction software for gage comparison experiments in the WIPP

    International Nuclear Information System (INIS)

    This manual describes the software developed for use by the HP9845 Desktop Computer to check, transfer, convert, and dump data taken on the gage comparison experiments in the Waste Isolation Pilot Plant (WIPP)

  19. Flow and gage monitoring records for Stillwater National Wildlife Refuge : 2000

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This file contains records of a survey of water flow, depth of water in the canal or unit gage height, and other comments, through selected points in the drainage...

  20. Six-component strain gage block scale 167-6B. Part 1: Calibration, September 1983

    Science.gov (United States)

    Wyss, C.

    1983-11-01

    The calibration of a six-component strain gage block balance for measurements in wind tunnels is described. The temperature dependance is considered. An error estimation is given. Calibration measurements are presented.

  1. Experiments to study strain gage load calibrations on a wing structure at elevated temperatures

    Science.gov (United States)

    Monaghan, R. C.; Fields, R. A.

    1973-01-01

    Laboratory experiments were performed to study changes in strain-gage bridge load calibrations on a wing structure heated to temperatures of 200 F, 400 F, and 600 F. Data were also obtained to define the experimental repeatability of strain-gage bridge outputs. Experiments were conducted to establish the validity of the superposition of bridge outputs due to thermal and mechanical loads during a heating simulation of Mach 3 flight. The strain-gage bridge outputs due to load cycle at each of the above temperature levels were very repeatable. A number of bridge calibrations were found to change significantly as a function of temperature. The sum of strain-gage bridge outputs due to individually applied thermal and mechanical loads compared well with that due to combined or superimposed loads. The validity of superposition was, therefore, established.

  2. Development of Displacement Gages Exposed to Solid Rocket Motor Internal Environments

    Science.gov (United States)

    Bolton, D. E.; Cook, D. J.

    2003-01-01

    The Space Shuttle Reusable Solid Rocket Motor (RSRM) has three non-vented segment-to-segment case field joints. These joints use an interference fit J-joint that is bonded at assembly with a Pressure Sensitive Adhesive (PSA) inboard of redundant O-ring seals. Full-scale motor and sub-scale test article experience has shown that the ability to preclude gas leakage past the J-joint is a function of PSA type, joint moisture from pre-assembly humidity exposure, and the magnitude of joint displacement during motor operation. To more accurately determine the axial displacements at the J-joints, two thermally durable displacement gages (one mechanical and one electrical) were designed and developed. The mechanical displacement gage concept was generated first as a non-electrical, self-contained gage to capture the maximum magnitude of the J-joint motion. When it became feasible, the electrical displacement gage concept was generated second as a real-time linear displacement gage. Both of these gages were refined in development testing that included hot internal solid rocket motor environments and simulated vibration environments. As a result of this gage development effort, joint motions have been measured in static fired RSRM J-joints where intentional venting was produced (Flight Support Motor #8, FSM-8) and nominal non-vented behavior occurred (FSM-9 and FSM-10). This data gives new insight into the nominal characteristics of the three case J-joint positions (forward, center and aft) and characteristics of some case J-joints that became vented during motor operation. The data supports previous structural model predictions. These gages will also be useful in evaluating J-joint motion differences in a five-segment Space Shuttle solid rocket motor.

  3. Application of Temperature Sensitivities During Iterative Strain-Gage Balance Calibration Analysis

    Science.gov (United States)

    Ulbrich, N.

    2011-01-01

    A new method is discussed that may be used to correct wind tunnel strain-gage balance load predictions for the influence of residual temperature effects at the location of the strain-gages. The method was designed for the iterative analysis technique that is used in the aerospace testing community to predict balance loads from strain-gage outputs during a wind tunnel test. The new method implicitly applies temperature corrections to the gage outputs during the load iteration process. Therefore, it can use uncorrected gage outputs directly as input for the load calculations. The new method is applied in several steps. First, balance calibration data is analyzed in the usual manner assuming that the balance temperature was kept constant during the calibration. Then, the temperature difference relative to the calibration temperature is introduced as a new independent variable for each strain--gage output. Therefore, sensors must exist near the strain--gages so that the required temperature differences can be measured during the wind tunnel test. In addition, the format of the regression coefficient matrix needs to be extended so that it can support the new independent variables. In the next step, the extended regression coefficient matrix of the original calibration data is modified by using the manufacturer specified temperature sensitivity of each strain--gage as the regression coefficient of the corresponding temperature difference variable. Finally, the modified regression coefficient matrix is converted to a data reduction matrix that the iterative analysis technique needs for the calculation of balance loads. Original calibration data and modified check load data of NASA's MC60D balance are used to illustrate the new method.

  4. A mechanical and histomorphometric analysis of bone bonding by hydroxyapatite-coated strain gages.

    Science.gov (United States)

    Wilson, D L; Szivek, J A; Anderson, P L; Miera, V L; Battraw, G A

    1998-01-01

    Identification of the strains controlling bone remodeling is important for determining ways to prevent bone loss due to load deprivation, or implant placement. Long-term monitoring of strains can potentially provide the best information. Glues are resorbed within 2-3 weeks. Two formulations of microcrystalline hydroxyapatite (HA) were used to attach strain gages to rat femora to assess their long-term in vivo strain measurement capability. Seven male rats received HA-coated gages, and 2 animals underwent a sham procedure. The gages were prepared using a published technique and placed on the antero-lateral aspect of the left femora. After 6-7 weeks, the animals were euthanized and both femora explanted. Gages were attached to the right femora with cyanoacrylate. All femora were tested in cantilever bending, then embedded, sectioned, and stained with mineralized bone stain. The undecalcified sections were examined using transmitted and ultraviolet light microscopy. Mechanical testing showed one HA formulation provided 70-100% bonding. Histology showed intimate contact between the gage and bone surface. Histomorphometry indicated increased bone activity under the gage compared to the remaining bone, the controls, and the shams. The results indicate that microcrystalline HAs bond to bone quickly and can allow long term in vivo measurements. PMID:9659635

  5. Overcoring and calibration of IRAD GAGE stressmeters at the Spent Fuel Test in Climax granite

    International Nuclear Information System (INIS)

    IRAD GAGE vibrating-wire stressmeters were installed in the Spent Fuel Facility at the Nevada Test Site to measure the change in in-situ stress during the Spent Fuel Test-Climax (SFT-C). Although extensive pre-installation laboratory tests were conducted, they were generic in nature. Unfortunately the degree of gage-rock contact has a strong influence on gage sensitivity and cannot be predicted before installation. This report discusses the results of removing a cylindrical section of rock and gages as a unit through overcoring and the subsequent post test calibrations of the stressmeters in the laboratory. With the assumption that the gage-rock contact was not disturbed by the overcoring, the results from these calibrations compensate for varying gage-rock contact. The estimated in-situ stresses based on post test calibration data are quite consistent with those directly measured in nearby holes. The magnitude of stress change calculated from pre-installation test data is generally much smaller than that estimated from post test calibration data

  6. Concrete strain gage in concrete shaft lining: Installation and monitoring procedure: Final draft

    International Nuclear Information System (INIS)

    A cast-in-place concrete or concrete block preliminary lining component and a cast-in-place final concrete lining form part of the shaft lining system. Strain measurements within the cast-in-place concrete linings will be obtained using a concrete strain gage (CSG). This gage consists of a vibrating wire sensor and anchors embedded in the concrete during casting CSGs will be installed in both exploratory shafts. The primary objective of the overall monitoring program, of which these gages constitute one part, is to define the stress-deformation behavior of the shaft lining, seals, and foundations during and after construction. For this purpose it is necessary to consider the CSG embedded in the concrete as one element of an integrated program of monitoring the mechanical and thermomechanical response of the shaft. Other instruments that form part of this program include concrete stress meters, steel strain gages on the steel shaft liner, convergence gages, piezometers, joint meters, bitumen pressure gages, temperature detectors, and extensometers. For a justification and basis for design of the instrument arrays which form part of the Shaft Mechanical and Thermal Response Monitoring, refer to the Draft Shaft Study Plan. 8 figs

  7. Design and development of a miniature column-based interface (MCBI) stress gage

    Science.gov (United States)

    Rickman, Denis D.

    1993-04-01

    Tests are routinely conducted to evaluate the survivability, under simulated battlefield conditions, of buried military structures subjected to high-explosive loadings. The survivability assessments require the measurement of dynamic normal stresses induced at soil/structure interfaces. Stresses in excess of 10,000 psi and accelerations greater than 100,000 g's may be applied at interface locations. Normal-incidence interface stress gages currently used in such tests are incapable of accurately measuring stresses above 5,000 psi, and are sensitive to lateral accelerations and structure-transmitted stresses which distort the measurement. This study explores the design, development, and testing of a miniature, column-based, interface (MCBI) stress gage. The MCBI gage is designed to measure normal stresses up to 35,000 psi. Laboratory tests indicate that the gage produces a linear output due to applied pressure and is virtually insensitive to lateral stresses. Explosive tests have shown the MCBI gage compares favorably to commonly-used interface stress gages at stresses up to 3,000 psi and is survivable at stresses up to 25,000 psi.

  8. Multibeam Sonar Backscatter Data Acquisition and Processing: Guidelines and Recommendations from the GEOHAB Backscatter Working Group

    Science.gov (United States)

    Heffron, E.; Lurton, X.; Lamarche, G.; Brown, C.; Lucieer, V.; Rice, G.; Schimel, A.; Weber, T.

    2015-12-01

    Backscatter data acquired with multibeam sonars are now commonly used for the remote geological interpretation of the seabed. The systems hardware, software, and processing methods and tools have grown in numbers and improved over the years, yet many issues linger: there are no standard procedures for acquisition, poor or absent calibration, limited understanding and documentation of processing methods, etc. A workshop organized at the GeoHab (a community of geoscientists and biologists around the topic of marine habitat mapping) annual meeting in 2013 was dedicated to seafloor backscatter data from multibeam sonars and concluded that there was an overwhelming need for better coherence and agreement on the topics of acquisition, processing and interpretation of data. The GeoHab Backscatter Working Group (BSWG) was subsequently created with the purpose of documenting and synthetizing the state-of-the-art in sensors and techniques available today and proposing methods for best practice in the acquisition and processing of backscatter data. Two years later, the resulting document "Backscatter measurements by seafloor-mapping sonars: Guidelines and Recommendations" was completed1. The document provides: An introduction to backscatter measurements by seafloor-mapping sonars; A background on the physical principles of sonar backscatter; A discussion on users' needs from a wide spectrum of community end-users; A review on backscatter measurement; An analysis of best practices in data acquisition; A review of data processing principles with details on present software implementation; and finally A synthesis and key recommendations. This presentation reviews the BSWG mandate, structure, and development of this document. It details the various chapter contents, its recommendations to sonar manufacturers, operators, data processing software developers and end-users and its implication for the marine geology community. 1: Downloadable at https://www.niwa.co.nz/coasts-and-oceans/research-projects/backscatter-measurement-guidelines

  9. On Uncertainty of Compton Backscattering Process

    CERN Document Server

    Mo, X H

    2013-01-01

    The uncertainty of Compton backscattering process is studied by virtue of analytical formulas, and the special effects of variant energy spread and energy drift on the systematic uncertainty estimation are also studied with Monte Carlo sampling technique. These quantitative conclusions are especially important for the understanding the uncertainty of beam energy measurement system.

  10. The single backscattering of gamma rays

    International Nuclear Information System (INIS)

    The paper presents the results of the single backscattering investigations of gamma rays in various materials. A simplified mathematical model is given for determining the probability that a photon scattered back by a single Compton scattering is incident on the detector. The probability is calculated as a function of the primary photon energy and the atomic number Z of the scatterer. (Auth.)

  11. BackscatterC [SWATH]--Offshore Pigeon Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Pigeon Point map area, California. Backscatter data are provided as three separate...

  12. BackscatterA [8101]--Offshore Pigeon Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Pigeon Point map area, California. Backscatter data are provided as three separate...

  13. BackscatterB [7125]--Offshore Pigeon Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Pigeon Point map area, California. Backscatter data are provided as three separate...

  14. BackscatterB [EM300]--Monterey Canyon and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Monterey Canyon and Vicinity map area, California. Backscatter data are provided as separate...

  15. BackscatterC [7125]--Monterey Canyon and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Monterey Canyon and Vicinity map area, California. Backscatter data are provided as separate...

  16. Backscatter D [USGS]--Offshore of Tomales Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Tomales Point map area, California. Backscatter data are provided as separate...

  17. BackscatterA [SWATH]--Offshore Aptos, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Aptos map area, California. Backscatter data are provided as two separate grids...

  18. BackscatterB [7125]--Offshore Scott Creek, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Scott Creek map area, California. Backscatter data are provided as three separate...

  19. Backscatter B [7125]--Offshore Half Moon Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Half Moon Bay map area, California. Backscatter data are provided as two...

  20. BackscatterC [SWATH]--Offshore Scott Creek, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Scott Creek map area, California. Backscatter data are provided as three separate...

  1. Backscatter C [8101]--Offshore of San Francisco, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of San Francisco map area, California. Backscatter data are provided as separate...

  2. Backscatter D [7125]--Offshore of San Francisco, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of San Francisco map area, California. Backscatter data are provided as separate...

  3. Backscatter C [Swath]--Offshore of Fort Ross, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Fort Ross map area, California. Backscatter data are provided as separate...

  4. Backscatter B [Swath]--Drakes Bay and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Drakes bay and Vicinity map area, California. Backscatter data are provided as separate grids...

  5. BackscatterA [8101]--Offshore Scott Creek, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Scott Creek map area, California. Backscatter data are provided as three separate...

  6. BackscatterB [EM300]--Offshore Aptos, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Offshore of Aptos map area, California. Backscatter data are provided as two separate grids...

  7. Backscatter A [8101]--Offshore of Bodega Head, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bodega Head map area, California. Backscatter data are provided as separate...

  8. Backscatter A [8101]--Offshore of Tomales Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Tomales Point map area, California. Backscatter data are provided as separate...

  9. Backscatter B [8101]--Offshore of San Francisco, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of San Francisco map area, California. Backscatter data are provided as separate...

  10. Backscatter A [8101]--Offshore Half Moon Bay, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Half Moon Bay map area, California. Backscatter data are provided as two...

  11. Backscatter C [Swath]--Offshore of Tomales Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Tomales Point map area, California. Backscatter data are provided as separate...

  12. Backscatter B [7125]--Offshore of Tomales Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Tomales Point map area, California. Backscatter data are provided as separate...

  13. Study of multibeam techniques for bathymetry and seabottom backscatter applications

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, R.R.; Chakraborty, B.

    Indian ocean is presented using Hydrosweep-multibeam installed onboard ORV Sagarkanya. A seabottom classification model is proposed which can be applied for multibeam backscatter data. Certain aspects of the multibeam backscatter signal data processing...

  14. Backscatter A [8101]--Offshore of Fort Ross, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Fort Ross map area, California. Backscatter data are provided as separate...

  15. Backscatter B [7125]--Offshore of Fort Ross, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Fort Ross map area, California. Backscatter data are provided as separate...

  16. Backscatter C [Swath]--Offshore of Bodega Head, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bodega Head map area, California. Backscatter data are provided as separate...

  17. Backscatter B [7125]--Offshore of Bodega Head, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bodega Head map area, California. Backscatter data are provided as separate...

  18. Backscatter A [8101]--Offshore of San Francisco, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of San Francisco map area, California. Backscatter data are provided as separate...

  19. Preliminary backscatter results from the hydrosweep multibeam system

    Digital Repository Service at National Institute of Oceanography (India)

    Hagen, R.A.; Chakraborty, B.; Schenke, H.W.

    of Oceanography to convert the measured electrical energy into acoustic backscatter energy. This conversion includes corrections for the position, slope, and area of the scattering surface. In this paper we present backscatter data from several areas surveyed...

  20. Inter-Technology Backscatter: Towards Internet Connectivity for Implanted Devices

    OpenAIRE

    Iyer, Vikram; Talla, Vamsi; Kellogg, Bryce; Gollakota, Shyamnath; Smith, Joshua R.

    2016-01-01

    We introduce inter-technology backscatter, a novel approach that transforms wireless transmissions from one technology to another, on the air. Specifically, we show for the first time that Bluetooth transmissions can be used to create Wi-Fi and ZigBee-compatible signals using backscatter communication. Since Bluetooth, Wi-Fi and ZigBee radios are widely available, this approach enables a backscatter design that works using only commodity devices. We build prototype backscatter hardware using ...

  1. Electromagnetic backscattering from one-dimensional drifting fractal sea surface II: Electromagnetic backscattering model

    Science.gov (United States)

    Tao, Xie; William, Perrie; Shang-Zhuo, Zhao; He, Fang; Wen-Jin, Yu; Yi-Jun, He

    2016-07-01

    Sea surface current has a significant influence on electromagnetic (EM) backscattering signals and may constitute a dominant synthetic aperture radar (SAR) imaging mechanism. An effective EM backscattering model for a one-dimensional drifting fractal sea surface is presented in this paper. This model is used to simulate EM backscattering signals from the drifting sea surface. Numerical results show that ocean currents have a significant influence on EM backscattering signals from the sea surface. The normalized radar cross section (NRCS) discrepancies between the model for a coupled wave-current fractal sea surface and the model for an uncoupled fractal sea surface increase with the increase of incidence angle, as well as with increasing ocean currents. Ocean currents that are parallel to the direction of the wave can weaken the EM backscattering signal intensity, while the EM backscattering signal is intensified by ocean currents propagating oppositely to the wave direction. The model presented in this paper can be used to study the SAR imaging mechanism for a drifting sea surface. Project supported by the National Natural Science Foundation of China (Grant No. 41276187), the Global Change Research Program of China (Grant No. 2015CB953901), the Priority Academic Program Development of Jiangsu Higher Education Institutions, China, the Program for the Innovation Research and Entrepreneurship Team in Jiangsu Province, China, the Canadian Program on Energy Research and Development, and the Canadian World Class Tanker Safety Service Program.

  2. Improved Regression Analysis of Temperature-Dependent Strain-Gage Balance Calibration Data

    Science.gov (United States)

    Ulbrich, N.

    2015-01-01

    An improved approach is discussed that may be used to directly include first and second order temperature effects in the load prediction algorithm of a wind tunnel strain-gage balance. The improved approach was designed for the Iterative Method that fits strain-gage outputs as a function of calibration loads and uses a load iteration scheme during the wind tunnel test to predict loads from measured gage outputs. The improved approach assumes that the strain-gage balance is at a constant uniform temperature when it is calibrated and used. First, the method introduces a new independent variable for the regression analysis of the balance calibration data. The new variable is designed as the difference between the uniform temperature of the balance and a global reference temperature. This reference temperature should be the primary calibration temperature of the balance so that, if needed, a tare load iteration can be performed. Then, two temperature{dependent terms are included in the regression models of the gage outputs. They are the temperature difference itself and the square of the temperature difference. Simulated temperature{dependent data obtained from Triumph Aerospace's 2013 calibration of NASA's ARC-30K five component semi{span balance is used to illustrate the application of the improved approach.

  3. Hidden Connections between Regression Models of Strain-Gage Balance Calibration Data

    Science.gov (United States)

    Ulbrich, Norbert

    2013-01-01

    Hidden connections between regression models of wind tunnel strain-gage balance calibration data are investigated. These connections become visible whenever balance calibration data is supplied in its design format and both the Iterative and Non-Iterative Method are used to process the data. First, it is shown how the regression coefficients of the fitted balance loads of a force balance can be approximated by using the corresponding regression coefficients of the fitted strain-gage outputs. Then, data from the manual calibration of the Ames MK40 six-component force balance is chosen to illustrate how estimates of the regression coefficients of the fitted balance loads can be obtained from the regression coefficients of the fitted strain-gage outputs. The study illustrates that load predictions obtained by applying the Iterative or the Non-Iterative Method originate from two related regression solutions of the balance calibration data as long as balance loads are given in the design format of the balance, gage outputs behave highly linear, strict statistical quality metrics are used to assess regression models of the data, and regression model term combinations of the fitted loads and gage outputs can be obtained by a simple variable exchange.

  4. Auroral backscatter observed at HF from Ottawa

    International Nuclear Information System (INIS)

    Bistatic HF radar recordings of auroral scattering sources north of Ottawa are reported. Doppler frequency spreads over + or - 100 Hz were obtained at least 35 percent of the time. The peak of the Doppler frequency distribution was sometimes shifted from zero by as much as 50 Hz, and significant contributions often occurred at Doppler frequencies greater than 150 Hz. Signals received simultaneously on both arms of a two-arm direction-finding array were used to identify the specific elevations and bearings of the backscatter signals. A detailed study of a particular hour-long period is reported, and a large number of 'apparent' auroral backscatter sources are identified. The source regions, probably located in the F layer, were elongated mainly in the north-south direction and extended over at least 3 deg of latitude. North-south corridors were found between such sources in which echo returns were either absent or very weak. 14 references

  5. Implementation of Doppler backscattering for MAST

    CERN Document Server

    Hillesheim, J C; Peebles, W A; Meyer, H; Meakins, A; Field, A R; Dunai, D; Carr, M; Hawkes, N

    2014-01-01

    A sixteen channel millimeter-wave diagnostic system, covering the frequency range 30-75 GHz, has been installed on MAST [B. Lloyd et al., Nucl. Fusion 43, 1665 (2003)] and has been successfully used for both Doppler backscattering (DBS) and conventional (normal-incidence) fluctuation reflectometry. DBS has become a well-established and versatile diagnostic technique for the measurement of intermediate- k ($k_{\\bot} \\rho_i \\sim 1$, and higher) density fluctuations and flows in magnetically confined fusion experiments. The $180^{\\circ}$ backscattering for DBS requires three dimensional wave-vector matching between the launched beam and the plasma fluctuations inducing the scattering, which are expected to be highly elongated along the magnetic field. The large pitch angle in MAST means that DBS implementation depends strongly on the capability to accurately launch the probing beam at a toroidal and poloidal angle that is matched to the magnetic field at the scattering location. We report on the scattering consi...

  6. Demonstration of differential backscatter absorption gas imaging

    International Nuclear Information System (INIS)

    Backscatter absorption gas imaging (BAGI) is a technique that uses infrared active imaging to generate real-time video imagery of gas plumes. We describe a method that employs imaging at two wavelengths (absorbed and not absorbed by the gas to be detected) to allow wavelength-differential BAGI. From the frames collected at each wavelength, an absorbance image is created that displays the differential absorbance of the atmosphere between the imager and the backscatter surface. This is analogous to a two-dimensional topographic differential absorption lidar or differential optical absorption spectroscopy measurement. Gas plumes are displayed, but the topographic scene image is removed. This allows a more effective display of the plume image, thus ensuring detection under a wide variety of conditions. The instrument used to generate differential BAGI is described. Data generated by the instrument are presented and analyzed to estimate sensitivity. (c) 2000 Optical Society of America

  7. Clip gage attachment for frictionless measurement of displacement during high-temperature mechanical testing

    Science.gov (United States)

    Alexander, David J.

    1994-01-01

    An attachment for placement between a test specimen and a remote clip gage extensometer providing improved fracture toughness tests of materials at elevated temperature. Using a cylindrical tube and axial rod in new relationship, the device transfers the displacement signal of the fracture toughness test specimen directly to a clip gage extensometer located outside the high temperature furnace. Virtually frictionless operation is assured by having the test specimen center one end of the rod in one end of the tube, while the clip gage extensometer arms center the other end of the rod in the other end of the tube. By providing positive control over both ends of both rod and tube, the attachment may be operated in orientations other than vertical.

  8. Calibration of high temperature strain gages. Kalibrierung von Hochtemperatur-Dehnungsmessstreifen

    Energy Technology Data Exchange (ETDEWEB)

    Hofstoetter; Weichsel

    1983-01-01

    Two procedures are examined for the calibration of the high temperature strain gages SG 125 and MG 125 manufactured by Eaton. The separation method developed by KWU and the modified damping method introduced by TUeV-Rheinland is tested up to temperatures of 315/sup 0/C. Both methods are well suited to limit the error interval for the SG 125 strain gages to about +- 30 ..mu..m/m in contrast to an error interval of +- 110 ..mu..m/m as reported by the manufacturer. The two methods, however, cannot be used in combination. In the case of the MG 125 strain gages with a shorter measuring length the results are not so promising. 38 figs.

  9. A new strain gage method for measuring the contractile strain ratio of Zircaloy tubing

    International Nuclear Information System (INIS)

    An improved strain gage method for determining the contractile strain ratio (CSR) of Zircaloy tubing was developed. The new method consists of a number of load-unload cyclings at approximately 0.2% plastic strain interval. With this method the CSR of Zircaloy-4 tubing could be determined accurately because it was possible to separate the plastic strains from the elastic strain involvement. The CSR values determined by use of the new method were in good agreement with those calculated from conventional post-test manual measurements. The CSR of the tubing was found to decrease with the amount of deformation during testing because of uneven plastic flow in the gage section. A new technique of inscribing gage marks by use of a YAG laser is discussed. (orig.)

  10. Detection of Bi-Directionality in Strain-Gage Balance Calibration Data

    Science.gov (United States)

    Ulbrich, Norbert

    2012-01-01

    An indicator variable was developed for both visualization and detection of bi-directionality in wind tunnel strain-gage balance calibration data. First, the calculation of the indicator variable is explained in detail. Then, a criterion is discussed that may be used to decide which gage outputs of a balance have bi- directional behavior. The result of this analysis could be used, for example, to justify the selection of certain absolute value or other even function terms in the regression model of gage outputs whenever the Iterative Method is chosen for the balance calibration data analysis. Calibration data of NASA s MK40 Task balance is analyzed to illustrate both the calculation of the indicator variable and the application of the proposed criterion. Finally, bi directionality characteristics of typical multi piece, hybrid, single piece, and semispan balances are determined and discussed.

  11. Connecting forest ecosystem and microwave backscatter models

    Science.gov (United States)

    Kasischke, Eric S.; Christensen, Norman L., Jr.

    1990-01-01

    A procedure is outlined to connect data obtained from active microwave remote sensing systems with forest ecosystem models. The hierarchy of forest ecosystem models is discussed, and the levels at which microwave remote sensing data can be used as inputs are identified. In addition, techniques to utilize forest ecosystem models to assist in the validation of theoretical microwave backscatter models are identified. Several examples to illustrate these connecting processes are presented.

  12. SuperDARN backscatter during intense geomagnetic storms

    Science.gov (United States)

    Currie, J. L.; Waters, C. L.; Menk, F. W.; Sciffer, M. D.; Bristow, W. A.

    2016-06-01

    It is often stated that high-frequency radars experience a loss of backscatter during geomagnetic storm events. The occurrence of backscatter during 25 intense geomagnetic storms was examined using data from the Bruny Island and Kodiak radars and a superposed epoch analysis. It was found that while a reduction of backscatter occurred in the middle to far ranges, there was an increase in the amount of backscatter from close range following storm onset. Ray tracing showed that an enhanced charge density in the E region can reduce the chance of F region and increase the chance of E region backscatter. It was also shown that reduction in backscatter cannot be explained by D region absorption. Using a normalized SYM-H value, percentage time through recovery phase can be estimated during storm progression which allows a prediction of backscatter return in real time that accounts for varying storm recovery phase duration.

  13. Stabilization of measuring channel of reflective gamma thickness gage by light pulses from additional scintillator

    International Nuclear Information System (INIS)

    Possibility for using a sodium iodide scintillator as a reference signal source is considered. Experimental data on studying the performance of a gamma thickness gage with an additional scintillator are given. Results of experimental investigations of a thickness gage dummy proved practical expediency of the principle being considered. It is established, in particular, that the device is ready to operate without warm-up with a constant sensitivity, the deviation not exceeding 0.5%, in the ambient temperature range of 15-25 deg C

  14. Identifying dissolved organic carbon sources at a gaged headwater catchment using FDOM sensors

    Science.gov (United States)

    Malzone, J. M.; Shanley, J. B.

    2014-12-01

    The United States Geological Survey's (USGS) W-9 gage at the headwaters of Sleepers River, Vermont has been monitored for dissolved organic carbon (DOC) concentration for more than 20 years. However, the sources of this DOC during base flow and hydrologic events remain unclear. The major objectives of this research were to identify sources of DOC during storm events and to explain the observed DOC-streamflow counterclockwise hysteresis during hydrologic events. Two main hypotheses to explain hysteresis during hydrologic events were tested: (1) distant headwater wetlands are the major DOC source, which lags behind peak flow due to travel time; and (2) the entire watershed contributes to the DOC at the gage, but the response of DOC lags behind the period when groundwater contributes most to streamflow. Sources of DOC were tracked using fluorescent dissolved organic matter (FDOM) sensors in surface water and groundwater wells. Wells were installed at four depths, 0.3, 0.6, 0.9, and 1.2 m, at four sites: a peaty low-gradient riparian area near the headwaters; a mid-hillslope area on a long hillslope mid-watershed; a near-stream area on a long hillslope mid-watershed; and a low-gradient tributary confluence area just above the gage. During storm events, FDOM and hydraulic head were measured at the nested groundwater wells. Samples for DOC analysis were also taken to determine the relationship between FDOM and DOC. Results suggest that both distant sources and the greater watershed played a role in the transport of DOC to the W-9 gage. Distant peaty sources dominated during large storms and contributed the highest surface water FDOM measurements. The peak FDOM at the gage was therefore best described as a result of transport. However, export from these distant sources terminated rapidly and did not explain continued elevated FDOM at the gage. Groundwater across the watershed exhibited hysteresis analogous to that in the stream itself, with FDOM peaking as head receded

  15. Application of semiempirical expressions to the alpha and beta radiometry of environmental depositions samples

    International Nuclear Information System (INIS)

    Were applied two semiempirical equations exponential beta absorption and Bragg-Kleeman approximation complementary to experimental corrections for beta backscattering and auto absorption of beta and alpha radiations in measurements of environmental depositions samples In the first case was verified the validity of mentioned corrections with an application boundary to mass greater than 300 Pb-210 (0.015 mg/cm2) In the second case, the Bragg-Kleeman approximation combined with the experimental beta corrections, bring a judgment to determine the fundamental alpha and beta emisors samples which results the Pb-210 group

  16. GAGE cancer-germline antigens are recruited to the nuclear envelope by germ cell-less (GCL)

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Rösner, Heike I; Pedersen, Christina B;

    2012-01-01

    metazoan transcriptional regulator, Germ cell-less (GCL), as an interaction partner of GAGE12I. GCL directly binds LEM-domain proteins (LAP2β, emerin, MAN1) at the nuclear envelope, and we found that GAGE proteins were recruited to the nuclear envelope inner membrane by GCL. Based on yeast two...

  17. Silicon strain gages bonded on stainless steel using glass frit for strain sensor applications

    International Nuclear Information System (INIS)

    In this paper, a steel pressure sensor using strain gages bonded on a 17–4 PH stainless steel (SS) diaphragm based on glass frit technology is proposed. The strain gages with uniform resistance are obtained by growing an epi-silicon layer on a single crystal silicon wafer using epitaxial deposition technique. The inorganic glass frits are used as the bonding material between the strain gages and the 17–4 PH SS diaphragm. Our results show that the output performances of sensors at a high temperature of 125 °C are almost equal those at room temperature, which indicates that the glass frit bonding is a good method and may lead to a significant advance in the high temperature applicability of silicon strain gage sensors. Finally, the microstructure of the cured organic adhesive and the fired glass frit are compared. It may be concluded that the defects of the cured organic adhesive deteriorate the hysteresis and repeatability errors of the sensors. (paper)

  18. Silicon strain gages bonded on stainless steel using glass frit for strain sensor applications

    Science.gov (United States)

    Zhang, Zongyang; Cheng, Xingguo; Leng, Yi; Cao, Gang; Liu, Sheng

    2014-05-01

    In this paper, a steel pressure sensor using strain gages bonded on a 17-4 PH stainless steel (SS) diaphragm based on glass frit technology is proposed. The strain gages with uniform resistance are obtained by growing an epi-silicon layer on a single crystal silicon wafer using epitaxial deposition technique. The inorganic glass frits are used as the bonding material between the strain gages and the 17-4 PH SS diaphragm. Our results show that the output performances of sensors at a high temperature of 125 °C are almost equal those at room temperature, which indicates that the glass frit bonding is a good method and may lead to a significant advance in the high temperature applicability of silicon strain gage sensors. Finally, the microstructure of the cured organic adhesive and the fired glass frit are compared. It may be concluded that the defects of the cured organic adhesive deteriorate the hysteresis and repeatability errors of the sensors.

  19. Iterative Strain-Gage Balance Calibration Data Analysis for Extended Independent Variable Sets

    Science.gov (United States)

    Ulbrich, Norbert Manfred

    2011-01-01

    A new method was developed that makes it possible to use an extended set of independent calibration variables for an iterative analysis of wind tunnel strain gage balance calibration data. The new method permits the application of the iterative analysis method whenever the total number of balance loads and other independent calibration variables is greater than the total number of measured strain gage outputs. Iteration equations used by the iterative analysis method have the limitation that the number of independent and dependent variables must match. The new method circumvents this limitation. It simply adds a missing dependent variable to the original data set by using an additional independent variable also as an additional dependent variable. Then, the desired solution of the regression analysis problem can be obtained that fits each gage output as a function of both the original and additional independent calibration variables. The final regression coefficients can be converted to data reduction matrix coefficients because the missing dependent variables were added to the data set without changing the regression analysis result for each gage output. Therefore, the new method still supports the application of the two load iteration equation choices that the iterative method traditionally uses for the prediction of balance loads during a wind tunnel test. An example is discussed in the paper that illustrates the application of the new method to a realistic simulation of temperature dependent calibration data set of a six component balance.

  20. Reducing parametric backscattering by polarization rotation

    CERN Document Server

    Barth, Ido

    2016-01-01

    When a laser passes through underdense plasmas, Raman and Brillouin Backscattering can reflect a substantial portion of the incident laser energy. This is a major loss mechanism, for example, in inertial confinement fusion. However, by slow rotation of the incident linear polarization, the overall reflectivity can be reduced significantly. Particle in cell simulations show that, for parameters similar to those of indirect drive fusion experiments, polarization rotation reduces the reflectivity by a factor of $5$. A general, fluid-model based, analytical estimation for the reflectivity reduction agrees with simulations.

  1. Interactive computer analysis of nuclear backscattering spectra

    International Nuclear Information System (INIS)

    A review will be made of computer-based interactive nuclear backscattering analysis system. Users without computer experience can develop moderate competence with the system after only brief instruction because of the menu-driven organization. Publishable quality figures can be obtained without any computer expertise. Among the quantities which can be displayed over the data are depth scales for any element, element identification, relative concentrations and theoretical spectra. Captions and titling can made from a selection of 30 font styles. Lettering is put on the graphs umder joy-stick control such that placement is exact without needing complicated commands. (orig.)

  2. Resampling Gaged Networks to Provide Uncertainty Estimates for Daily Streamflow Predictions in Ungaged Basins

    Science.gov (United States)

    Farmer, W. H.; Over, T. M.; Vogel, R. M.; Archfield, S. A.; Kiang, J. E.

    2014-12-01

    In ungaged basins, predictions of daily streamflow are essential to responsible and effective management and design of water resources systems. Transfer-based methods are widely used for prediction in ungaged basins (PUB) within a gaged network. Such methods rely on the transfer of information from an index gage to an ungaged site. In what is known as the nearest-neighbor algorithm, the index gage is selected based on geospatial proximity. The predictions offered by any PUB method can be highly uncertain, and it is often difficult to characterize this uncertainty. In the development of predicted streamflow records, understanding the uncertainty of estimates would greatly improve water resources management in ungaged basins. It is proposed that by resampling the sites of the gaged network, with replacement, a set of equally-probable streamflow predictions can be produced for any ungaged site. For a particular day in the record, the percentiles of the distribution of the resampled, predicted streamflows can be used to estimate confidence intervals of the original daily streamflow predictions. This approach is explored in the Southeast United States with a nearest-neighbor application of non-linear spatial interpolation using flow duration curves (QPPQ), a common PUB method. Though some interval re-centering is required to ensure that the best-case prediction falls within the confidence intervals, it is shown that this technique provides a reasonable first-order approximation of prediction uncertainty. Still, the best estimated confidence intervals are shown to consistently under-estimate the nominal confidence. It is hypothesized that this interval contraction is a result of temporal and spatial correlation within the gaged network. Additionally, implications of prediction uncertainty are explored and alternative estimators are considered.

  3. Data acquisition from vacuum gage controlled by RS-232 standard using LabVIEW

    International Nuclear Information System (INIS)

    This paper deals with the problem of connecting a microcontroller-based vacuum gage to a personal computer, using the RS-232 hardware standard and the software LabVIEW and his collection of virtual instruments from National Instruments. To solve the problem an instrument driver was created. This provided the customer with a perfect solution for the remote control and data acquisition from an Intel 80CXX microcontroller-based vacuum gage. The remote control making use of an IBM-PC was design and manufactured in our institute. In order to make it intelligent the device was provided with a microprocessor or a microcontroller. To fulfill the requirements a vacuum gage with an 80C31 microcontroller and two Bayard-Alpert ion gauges, for very low pressures (10-3 to 10-7 mbar) and low pressure (10 mbar to 10-3 mbar) was built. Because this microcontroller has a built-in circuitry for a serial communication, we established a serial communication between the PC (Pentium -166 MHz) and the vacuum gage, according to the RS-232 hardware standard. Optimum selection of software development tools however, was not as straightforward. Most producers use the C/C++ - language programming tool for developing instrument drivers for their intelligent devices. One of the advantages of C/C++ is its speed, but the compilation and the high-level skill required for optimum programming do not fit well with some requirements, particularly those of versatility, upgradability and user friendliness. After careful evaluation of several options, a final decision was to develop a hybrid software package using two different software development tools: LabVIEW, and assembly language. We chose LabVIEW because it is dedicated to data acquisition and communications, containing libraries for data collection, analysis, presentation and storage. The assembly language for Intel 8051's microcontrollers family is used to write the firmware for the vacuum gage and arithmetic routines. (authors)

  4. Understanding the radar backscattering from flooded and nonflooded Amazonian forests: results from canopy backscatter modeling

    International Nuclear Information System (INIS)

    To understand the potential of using multiwavelength imaging radars to detect flooding in Amazonian floodplain forests, we simulated the radar backscatter from a floodplain forest with a flooded or nonflooded ground condition at C-, L-, and P-bands. Field measurements of forest structure in the Anavilhanas archipelago of the Negro River, Brazil, were used as inputs to the model. Given the same wavelength or incidence angle, the ratio of backscatter from the flooded forest to that from the nonflooded forest was higher at HH polarization than at VV polarization. Given the same wavelength or polarization, the ratio was larger at small incidence angles than at large incidence angles. Given the same polarization or incidence angle, the ratio was larger at a long wavelength than at a short wavelength. As the surface soil moisture underneath the nonflooded forest increased from 10% to 50% of volumetric moisture, the flooded/nonflooded backscatter ratio decreased; the decreases were small at C- and L-band but large at P-band. When the leaf size was comparable to or larger than the wavelength of C-band, the leaf area index (LAI) had a large effect on the simulated C-band (not L-band or P-band) backscatter from the flooded and nonflooded forests. (author)

  5. CRED Acoustic Backscatter Guam 2003, Imagery Extracted from Gridded Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Backscatter extracted from gridded bathymetry of the banktops and shelf environments of Guam, of the Mariana Islands Archipelago.

  6. Effect of Pressure on Intracardiac Backscatter from Microbubbles

    Institute of Scientific and Technical Information of China (English)

    DENG; Youbin; LI; Chunlei; CHANG; Qing

    2001-01-01

    The backscatter from sonicated albumin microbubbles (Albunex) was analyzed using acoustic densitometry in an in vitro pulsatile heart model to evaluate the effects of pressure on the backscatter from Albunex, and the cardiac cyclic changes of intracardiac backscatter from sonicated albumin microbubbles in 16 healthy persons were analyzed. It was found that the Albunex microbubbles were compressed in systole and decompressed in diastole, causing corresponding changes of backscatter in cardiac cycle. Although the intensities of backscatter in diastole and systole were related to the concentration of microbubbles, the concentration of microbubbles had no effect on the difference of end-diastolic and end-systolic backscatter. The difference of the backscatter was highly correlated with end-systolic pressure (r = 0. 96, P = 0. 001). In human studies, we also observed same intracardiac cyclic changes of backscatter from sonicated albumin microbubbles. Our study indicates that it is possible to evaluate the intracardiac pressure non-invasively by analyzing the intracardiac backscatter from the microbubbles with acoustic densitometry.

  7. Chiral Receiving Antenna With Low Backscattering Levels

    CERN Document Server

    Karilainen, Antti O

    2011-01-01

    Receiving antennas absorb power from incident waves, but they also re-radiate some power into surrounding space. If a receiving antenna is to be used as a sensor which should not disturb the object under study, it should scatter as little power as possible in the receiving direction. We propose to use a chiral element composed of two orthogonal chiral particles as a low-scattering sensor.The element can transmit and receive circular polarization in all directions with the Huygens' pattern. We derive the vector effective length for the antenna using the small dipole approximation for the chiral particles. We observe that the element does not backscatter, regardless of the polarization, when the incidence direction is normal to the plane of the particles. Scattered fields, scattered axial ratio, and the scattering cross section are presented. We show that the zero-backscattering property holds also for the antenna element when it is capable to receive all the available power with conjugate loading. The approxim...

  8. Evaluation test of high temperature strain gages used in a stethoscope for OGL-1 components in an elevated temperature service

    International Nuclear Information System (INIS)

    The stethoscope for OGL-1 components in a elevated temperature service (SOCETS) is a measuring system of evaluation integrity of structures for high temperature pipings during operations of Japan Material Testing Reactor. This paper is described about the results on fundamental performance on high temperature strain gages. From their test results that have been based on correlation of temperature-timestrain factors, it became clear that two weldable strain gages and a capacitance strain gage were available for strain measurements of OGL-1 components. (author)

  9. Evaluation test of high temperature strain gages used in a stethoscope for OGL-1 components in an elevated temperature service

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Toshimi (Kyowa Electronic Inst. Co. Ltd. (Japan)); Tanaka, Isao; Komori, Yoshihiro; Suzuki; Toshiaki

    1982-08-01

    The stethoscope for OGL-1 components in a elevated temperature service (SOCETS) is a measuring system of evaluation integrity of structures for high temperature pipings during operations of Japan Material Testing Reactor. This paper is described about the results on fundamental performance on high temperature strain gages. From their test results that have been based on correlation of temperature-timestrain factors, it became clear that two weldable strain gages and a capacitance strain gage were available for strain measurements of OGL-1 components.

  10. Design, Analysis, and Initial Testing of a Fiber-Optic Shear Gage for 3D, High-Temperature Flows

    OpenAIRE

    Orr, Matthew William

    2004-01-01

    Design, Analysis, and Initial Testing of a Fiber-Optic Shear Gage for 3D, High-Temperature Flows Matthew W. Orr Dr. Joseph A. Schetz, Chairman Aerospace Engineering Abstract This investigation concerns the design, analysis, and initial testing of a new, two-component wall shear gage for 3D, high-temperature flows. This gage is a direct-measuring, non-nulling design with a round head surrounded by a small gap. Two flexure wheels are used to allow small motions of the flo...

  11. The Harwell back-scattering spectrometer

    International Nuclear Information System (INIS)

    Neutron diffraction spectra in which both high resolution (Δ Q/Q approximately equal to 0.003) and high intensity are maintained up to scattering vectors as high as 30A-1(sin theta/lambda = 2.5) have been obtained with the back-scattering spectrometer (BSS) recently installed on the Harwell electron linac. The theory behind the spectrometer design is described, and it is shown how the above resolution requirement leads to its basic features of a 12m incident flight path, a 2m scattering flight path and a scattering angle (2theta) acceptance from 1650 to 1750. Examples of the resolution, intensity and background are given. It is shown that the problem of frame overlap may be overcome by using an absorbing filter. (author)

  12. Electron backscatter diffraction in materials characterization

    Directory of Open Access Journals (Sweden)

    Dejan Stojakovic

    2012-03-01

    Full Text Available Electron Back-Scatter Diffraction (EBSD is a powerful technique that captures electron diffraction patterns from crystals, constituents of material. Captured patterns can then be used to determine grain morphology, crystallographic orientation and chemistry of present phases, which provide complete characterization of microstructure and strong correlation to both properties and performance of materials. Key milestones related to technological developments of EBSD technique have been outlined along with possible applications using modern EBSD system. Principles of crystal diffraction with description of crystallographic orientation, orientation determination and phase identification have been described. Image quality, resolution and speed, and system calibration have also been discussed. Sample preparation methods were reviewed and EBSD application in conjunction with other characterization techniques on a variety of materials has been presented for several case studies. In summary, an outlook for EBSD technique was provided.

  13. The dose from Compton backscatter screening.

    Science.gov (United States)

    Rez, Peter; Metzger, Robert L; Mossman, Kenneth L

    2011-04-01

    Systems based on the detection of Compton backscattered X rays have been deployed for screening personnel for weapons and explosives. Similar principles are used for screening vehicles at border-crossing points. Based on well-established scattering cross sections and absorption coefficients in conjunction with reasonable estimates of the image contrast and resolution, the entrance skin dose and the dose at a depth of 1 cm can be calculated. The effective dose can be estimated using the same conversion coefficients as used to convert exposure measurements to the effective dose. It is shown that the effective dose is highly dependent on image resolution (i.e. pixel size).The effective doses for personnel screening systems are unlikely to be in compliance with the American National Standards Institute standard NS 43.17 unless the pixel sizes are >4 mm. Nevertheless, calculated effective doses are well below doses associated with health effects. PMID:21068018

  14. Simulation of ultrasound backscatter images from fish

    DEFF Research Database (Denmark)

    Pham, An Hoai; Stage, Bjarne; Hemmsen, Martin Christian;

    2011-01-01

    The objective of this work is to investigate ultrasound (US) backscatter in the MHz range from fis to develop a realistic and reliable simulation model. The long term objective of the work is to develop the needed signal processing for fis species differentiation using US. In in-vitro experiments......, a cod (Gadus morhua) was scanned with both a BK Medical ProFocus 2202 ultrasound scanner and a Toshiba Aquilion ONE computed tomography (CT) scanner. The US images of the fis were compared with US images created using the ultrasound simulation program Field II. The center frequency of the transducer...... is 10 MHz and the Full Width at Half Maximum (FWHM) at the focus point is 0.54 mm in the lateral direction. The transducer model in Field II was calibrated using a wire phantom to validate the simulated point spread function. The inputs to the simulation were the CT image data of the fis converted to...

  15. Strong Localization in Disordered Media: Analysis of the Backscattering Cone

    KAUST Repository

    Delgado, Edgar

    2012-06-01

    A very interesting effect in light propagation through a disordered system is Anderson localization of light, this phenomenon emerges as the result of multiple scattering of waves by electric inhomogeneities like spatial variations of index of refraction; as the amount of scattering is increased, light propagation is converted from quasi-diffusive to exponentially localized, with photons confined in a limited spatial region characterized by a fundamental quantity known as localization length. Light localization is strongly related to another interference phenomenon emerged from the multiple scattering effect: the coherent backscattering effect. In multiple scattering of waves, in fact, coherence is preserved in the backscattering direction and produces a reinforcement of the field flux originating an observable peak in the backscattered intensity, known as backscattering cone. The study of this peak provide quantitative information about the transport properties of light in the material. In this thesis we report a complete FDTD ab-initio study of light localization and coherent backscattering. In particular, we consider a supercontinuum pulse impinging on a sample composed of randomly positioned scatterers. We study coherent backscattering by averaging over several realizations of the sample properties. We study then the coherent backscattering cone properties as the relative permittivity of the sample is changed, relating the latter with the light localization inside the sample. We demonstrate important relationships between the width of the backscattering cone and the localization length, which shows a linear proportionality in the strong localization regime.

  16. Rutherford backscattering in an industrial environment

    International Nuclear Information System (INIS)

    Rutherford Backscattering spectrometry (RBS) is a well established analytical technique, particularly in the university and major research oriented industrial laboratories. Historically, the accelerators used for RBS analysis have been renovated low energy nuclear physics rather than a dedicated optimally designed analytical instrument. It is this 'requirement' that each machine be individually rebuilt prior to use as a materials analysis tool that has contributed to the limited industrial use of RBS when compared with other analytical techniques such as Auger spectroscopy or Secondary Ion Mass spectrometry (SIMS). This paper will discuss the design criteria and applications of an RBS system for use in an industrial analytical environment. The design issues which are discussed include the backscattered particle detection, sample positioning, charge integration, vacuum, and automation systems. An RBS system for which the design of these systems has been optimized in light of many current industrial applications will be evaluated. The prototype of this system has been tested for the previous two years with a utilization factor of 4000-5000 individual analyses per year. The applications which have been investigated extend from the familiar electronics related topics to many other diverse fields such as polymeric chemistry, catalysis, and surface modification of synthetic fibers. Some of the electronics applications include high throughput 'production line' analysis of silicides, copper doped aluminium, and similar interconnect materials as well as the more sophisticated trace impurity mapping techniques which involve channeled line scans. Catalysis applications include the study of cage compound zeolite particle and the depth distribution of the active catalyst in these particles. Applications in the field of synthesis fibers include the study of the depth distribution of coloring agents and dyes in the near surface region of the fibers. (orig.)

  17. CHANGES OF BACKSCATTERING PARAMETERS DURING CHILLING INJURY IN BANANAS

    Directory of Open Access Journals (Sweden)

    NORHASHILA HASHIM

    2014-06-01

    Full Text Available The change in backscattering parameters during the appearance of chilling injury in bananas was investigated. Bananas were stored at a chilling temperature for two days and the degrees of the chilling injuries that appeared were measured before, during and after storage using backscattering imaging and visual assessment. Laser lights at 660 nm and 785 nm wavelengths were shot consecutively onto the samples in a dark room and a camera was used to capture the backscattered lights that appeared on the samples. The captured images were analysed and the changes of intensity against pixel count were plotted into graphs. The plotted graph provides useful information of backscattering parameters such as inflection point (IP, slope after inflection point (SA, and full width at half maximum (FWHM and saturation radius (RSAT. Results of statistical analysis indicated that there were significant changes of these backscattering parameters as chilling injury developed.

  18. Backscattering at a pulsed neutron source, the MUSICAL instrument

    International Nuclear Information System (INIS)

    In the first part the principles of the neutron backscattering method are described and some simple considerations about the energy resolution and the intensity are presented. A prototype of a backscattering instrument, the first Juelich instrument, is explained in some detail and a representative measurement is shown which was performed on the backscattering instrument IN10 at the ILL in Grenoble. In the second part a backscattering instrument designed for a pulsed neutron source is proposed. It is shown that a rather simple modification, which consists in the replacement of the Doppler drive of the conventional backscattering instrument by a multi silicon monochromator crystal (MUSICAL) leads to a very effective instrument, benefitting from the peak flux of the pulsed source. ((orig.))

  19. Channel stability downstream from a dam assessed using aerial photographs and stream-gage information

    Science.gov (United States)

    Juracek, K.E.

    2000-01-01

    The stability of the Neosho River channel downstream from John Redmond Dam, in southeast Kansas, was investigated using multiple-date aerial photographs and stream-gage information. Bankfull channel width was used as the primary indicator variable to assess pre- and post-dam channel change. Five six-mile river reaches and four stream gages were used in the analysis. Results indicated that, aside from some localized channel widening, the overall channel change has been minor with little post-dam change in bankfull channel width. The lack of a pronounced postdam channel change may be attributed to a substantial reduction in the magnitude of the post-dam annual peak discharges in combination with the resistance to erosion of the bed and bank materials. Also, the channel may have been overwidened by a series of large floods that predated construction of the dam, including one with an estimated 500-year recurrence interval.

  20. High temperature static strain gage development contract, tasks 1 and 2. Interim report

    International Nuclear Information System (INIS)

    Results are presented for the first two tasks to develop resistive strain gage systems for use up to 1250 K on blades and vanes in gas turbine engines under tests. The objective of these two tasks was to further improve and evaluate two static strain gage alloys identified as candidates in a previous program. Improved compositions were not found for either alloy. Further efforts on the Fe-11.9Al-10.6Cr weigth percent alloy were discontinued because of time dependent drift problems at 1250 K in air. When produced as a 6.5 micrometer thick sputtered film, the Pd-13Cr weight percent alloys is not sufficiently stable for this use in air at 1250 K and a protective overcoat system will need to be developed

  1. Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of an Inflatable Module

    Science.gov (United States)

    Valle, Gerard D.; Selig, Molly; Litteken, Doug; Oliveras, Ovidio

    2012-01-01

    This paper documents the integration of a large hatch penetration into an inflatable module. This paper also documents the comparison of analytical load predictions with measured results utilizing strain measurement. Strain was measured by utilizing photogrammetric measurement and through measurement obtained from strain gages mounted to selected clevises that interface with the structural webbings. Bench testing showed good correlation between strain measurement obtained from an extensometer and photogrammetric measurement especially after the fabric has transitioned through the low load/high strain region of the curve. Test results for the full-scale torus showed mixed results in the lower load and thus lower strain regions. Overall strain, and thus load, measured by strain gages and photogrammetry tracked fairly well with analytical predictions. Methods and areas of improvements are discussed.

  2. Utilizing Photogrammetry and Strain Gage Measurement to Characterize Pressurization of Inflatable Modules

    Science.gov (United States)

    Mohammed, Anil

    2011-01-01

    This paper focuses on integrating a large hatch penetration into inflatable modules of various constructions. This paper also compares load predictions with test measurements. The strain was measured by utilizing photogrammetric methods and strain gages mounted to select clevises that interface with the structural webbings. Bench testing showed good correlation between strain data collected from an extensometer and photogrammetric measurements, even when the material transitioned from the low load to high load strain region of the curve. The full-scale torus design module showed mixed results as well in the lower load and high strain regions. After thorough analysis of photogrammetric measurements, strain gage measurements, and predicted load, the photogrammetric measurements seem to be off by a factor of two.

  3. New approach for calibration and interpretation of IRAD GAGE vibrating-wire stressmeters

    International Nuclear Information System (INIS)

    IRAD GAGE vibrating-wire stressmeters were installed in the Spent Fuel Facility at the Nevada Test Site to measure the change in in-situ stress during the Spent Fuel Test-Climax (SFT-C). This paper discusses the results of removing a cylindrical section of rock and gages as a unit through overcoring, and the subsequent post-test calibration of the stressmeters in the laboratory. The estimated in-situ stresses based on post test calibration data are quite consistent with those directly measured in nearby holes. The magnitude of stress change calculated from pre-test calibration data is generally much smaller than that estimated from post test calibration data. 11 refs., 5 figs., 2 tabs

  4. Cost-effectiveness of the US Geological Survey stream-gaging program in Arkansas

    Science.gov (United States)

    Darling, M.E.; Lamb, T.E.

    1984-01-01

    This report documents the results of the cost-effectiveness of the stream-gaging program in Arkansas. Data uses and funding sources were identified for the daily-discharge stations. All daily-discharge stations were found to be in one or more data use categories, and none were candidates for alternate methods which would result in discontinuation or conversion to a partial record station. The cost for operation of daily-discharge stations and routing costs to partial record stations, crest gages, pollution control stations as well as seven recording ground-water stations was evaluated in the Kalman-Filtering Cost-Effective Resource allocation (K-CERA) analysis. This operation under current practices requires a budget of $292,150. The average standard error of estimate of streamflow record for the Arkansas District was analyzed at 33 percent.

  5. Improving the reliability of high pressure reciprocating compressors by strain gage measurements

    International Nuclear Information System (INIS)

    The paper presents a combined experimental and numerical investigation of the structure of two high pressure reciprocating compressors. The experimental work was done by strain gage measurements. Its purpose was to put in evidence the place where the dangerous stresses occured and to validate FE models. These ones were used to find solutions to reduce the peak of the stresses, minimizing in this way failure risk of compressors body. (orig.)

  6. Strain gage balance for half models 302-6. Calibration report

    Science.gov (United States)

    Blaettler, Heinz

    1986-02-01

    A six-component strain gage balance for half models 302-6 for the transonic wind tunnel was developed and calibrated. The calibration was executed with a special lever, so that forces and moments could be loaded at the point of attack of the model. Point 8 (for recording buffering) was also measured. The balance is conceived for: X = +/- 100 (N); Mx = +/- 200 (Nm); Y = +/- 200 (N); My = +/- 35 (Nm); Z = +/- 1000 (N); and Mz = +/- 30 (Nm).

  7. Application of capsule type strain gage and fiber optic grating strain sensor for measurement of strain under irradiation environment

    International Nuclear Information System (INIS)

    In Japan Atomic Energy Research Institute, in-pile strain measurement techniques have been developing by using JMTR. In order to evaluate the performance of capsule type strain gage and fiber optic grating sensor under irradiation environment, the heat-up tests in electric furnace before irradiation and in-pile tests were performed. As for capsule type strain gage, it is found that gage factor almost did not change and both its electric resistance and strain output decreased by irradiation effect. A correlation was found between the change ratio of the electric resistance of the capsule type strain gage and fast neutron fluence. As for fiber optic grating sensor, it is possible to measure strain under irradiation environment below 1x1023 n/m2 (E>1 MeV) by this sensor, because in-pile temperature characteristic was in agreement with out-of-pile test results. (author)

  8. Methodology to measure strains at high temperatures using electrical strain gages with free filaments

    International Nuclear Information System (INIS)

    An experimental methodology used for strains measuring at high temperatures is show in this work. In order to do the measurements, it was used electric strain gages with loose filaments attached to a stainless steel 304 beam with specific cements. The beam has triangular shape and a constant thickness, so the strain is the same along its length. Unless the beam surface be carefully prepared, the strain gage attachment is not efficient. The showed results are for temperatures ranging from 20 deg C to 300 deg C, but the experimental methodology could be used to measure strains at a temperature up to 900 deg C. Analytical calculations based on solid mechanics were used to verify the strain gage electrical installation and the measured strains. At a first moment, beam deformations as a temperature function were plotted. After that, beam deformations with different weighs were plotted as a temperature function. The results shown allowed concluding that the experimental methodology is trustable to measure strains at temperatures up to 300 deg C. (author)

  9. Fiber-Optic Strain-Gage Tank Level Measurement System for Cryogenic Propellants

    Science.gov (United States)

    Figueroa, Fernando; Mitchell, Mark; Langford, Lester

    2004-01-01

    Measurement of tank level, particularly for cryogenic propellants, has proven to be a difficult problem. Current methods based on differential pressure, capacitance sensors, temperature sensors, etc.; do not provide sufficiently accurate or robust measurements, especially at run time. These methods are designed to measure tank-level, but when the fluids are in supercritical state, the liquid-gas interface disappears. Furthermore, there is a need for a non-intrusive measurement system; that is, the sensors should not require tank modifications and/or disturb the fluids. This paper describes a simple, but effective method to determine propellant mass by measuring very small deformations of the structure supporting the tank. Results of a laboratory study to validate the method, and experimental data from a deployed system are presented. A comparison with an existing differential pressure sensor shows that the strain gage system provides a much better quality signal across all regimes during an engine test. Experimental results also show that the use of fiber optic strain gages (FOSG) over classic foil strain gages extends the operation time (before the system becomes uncalibrated), and increases accuracy. Finally, a procedure is defined whereby measurements from the FOSG mounted on the tank supporting structure are compensated using measurements of a FOSG mounted on a reference plate and temperature measurements of the structure. Results describing the performance of a deployed system that measures tank level during propulsion tests are included.

  10. Strain-gage balance calibration of a magnetic suspension and balance system

    Science.gov (United States)

    Roberts, Paul W.; Tcheng, Ping

    1987-01-01

    A load calibration of the NASA 13-in magnetic suspension and balance system (MSBS) is described. The calibration procedure was originally intended to establish the empirical relationship between the coil currents and the external loads (forces and moments) applied to a magnetically suspended calibrator. However, it was discovered that the performance of a strain-gage balance is not affected when subjected to the magnetic environment of the MSBS. The use of strain-gage balances greatly reduces the effort required to perform a current-vs.-load calibration as external loads can be directly inferred from the balance outputs while a calibrator is suspended in MSBS. It is conceivable that in the future such a calibration could become unnecessary, since an even more important application for the use of a strain-gage balance in MSBS environment is the acquisition of precision aerodynamic force and moment data by telemetering the balance outputs from a suspended model/core/balance during wind tunnel tests.

  11. Strain-gage balance calibration of a magnetic suspension and balance system

    Science.gov (United States)

    Roberts, Paul W.; Tcheng, Ping

    A load calibration of the NASA 13-in magnetic suspension and balance system (MSBS) is described. The calibration procedure was originally intended to establish the empirical relationship between the coil currents and the external loads (forces and moments) applied to a magnetically suspended calibrator. However, it was discovered that the performance of a strain-gage balance is not affected when subjected to the magnetic environment of the MSBS. The use of strain-gage balances greatly reduces the effort required to perform a current-vs.-load calibration as external loads can be directly inferred from the balance outputs while a calibrator is suspended in MSBS. It is conceivable that in the future such a calibration could become unnecessary, since an even more important application for the use of a strain-gage balance in MSBS environment is the acquisition of precision aerodynamic force and moment data by telemetering the balance outputs from a suspended model/core/balance during wind tunnel tests.

  12. Cost effectiveness of the US Geological Survey stream-gaging program in Alabama

    Science.gov (United States)

    Jeffcoat, H.H.

    1987-01-01

    A study of the cost effectiveness of the stream gaging program in Alabama identified data uses and funding sources for 72 surface water stations (including dam stations, slope stations, and continuous-velocity stations) operated by the U.S. Geological Survey in Alabama with a budget of $393,600. Of these , 58 gaging stations were used in all phases of the analysis at a funding level of $328,380. For the current policy of operation of the 58-station program, the average standard error of estimation of instantaneous discharge is 29.3%. This overall level of accuracy can be maintained with a budget of $319,800 by optimizing routes and implementing some policy changes. The maximum budget considered in the analysis was $361,200, which gave an average standard error of estimation of 20.6%. The minimum budget considered was $299,360, with an average standard error of estimation of 36.5%. The study indicates that a major source of error in the stream gaging records is lost or missing data that are the result of streamside equipment failure. If perfect equipment were available, the standard error in estimating instantaneous discharge under the current program and budget could be reduced to 18.6%. This can also be interpreted to mean that the streamflow data records have a standard error of this magnitude during times when the equipment is operating properly. (Author 's abstract)

  13. A New Load Residual Threshold Definition for the Evaluation of Wind Tunnel Strain-Gage Balance Data

    Science.gov (United States)

    Ulbrich, N.; Volden, T.

    2016-01-01

    A new definition of a threshold for the detection of load residual outliers of wind tunnel strain-gage balance data was developed. The new threshold is defined as the product between the inverse of the absolute value of the primary gage sensitivity and an empirical limit of the electrical outputs of a strain{gage. The empirical limit of the outputs is either 2.5 microV/V for balance calibration or check load residuals. A reduced limit of 0.5 microV/V is recommended for the evaluation of differences between repeat load points because, by design, the calculation of these differences removes errors in the residuals that are associated with the regression analysis of the data itself. The definition of the new threshold and different methods for the determination of the primary gage sensitivity are discussed. In addition, calibration data of a six-component force balance and a five-component semi-span balance are used to illustrate the application of the proposed new threshold definition to different types of strain{gage balances. During the discussion of the force balance example it is also explained how the estimated maximum expected output of a balance gage can be used to better understand results of the application of the new threshold definition.

  14. Characterization of the backscattered radiation from petawatt laser matter interactions

    International Nuclear Information System (INIS)

    The development of high peak power and energy laser systems require the assurance that any backscattered radiation will not lead to damage of the laser system. We present the characterization of the backscattered radiation for different target types and conditions at petawatt power levels and intensities (>1020W/cm2). We observe that radiation is generated between 700 and 900 nm, as well as the expected self emission and laser fundamental. The percentage of the incident light backscattered reduces as a function of the incident energy and is typically <1% for petawatt laser interactions

  15. Statistical simulation of multiple Compton backscattering process

    Science.gov (United States)

    Potylitsyn, A. P.; Kolchuzhkin, A. M.

    2014-09-01

    A number of laboratories are currently developing monochromatic sources of X-rays and gamma quanta based on the Compton backscattering (CBS) of laser photons by relativistic electrons. Modern technologies are capable of providing a concentration of electrons and photons in the interaction point such that each primary electron can emit several hard photons. In contrast to the well-known nonlinear CBS process, in which an initial electron "absorbs" a few laser photons and emits a single hard one, the above-mentioned process can be called a multiple CBS process and is characterized by a mean number of emitted photons. The present paper is devoted to simulating the parameters of a beam of back scattered quanta based on the Monte Carlo technique. It is shown that, even in the case of strong collimation of a resulting photon beam, the radiation monochromaticity may deteriorate because of the contribution coming from the multiple photon emission, which is something that must be considered while designing new CBS sources.

  16. X-Ray Backscatter Machine Support Frame

    Science.gov (United States)

    Cannon, Brooke

    2010-01-01

    This summer at Kennedy Space Center, I spent 10 weeks as an intern working at the Prototype Development Lab. During this time I learned about the design and machining done here at NASA. I became familiar with the process from where a design begins in Pro/Engineer and finishes at the hands of the machinists. As an intern I was given various small jobs to do and then one project of my own. My personal project was a job for the Applied Physics Lab; in their work they use an X-Ray Backscatter machine. Previously it was resting atop a temporary frame that limited the use of the machine. My job was to design a frame for the machine to rest upon that would allow a full range of sample sizes. The frame was required to support the machine and provide a strain relief for the cords attached to the machine as it moved in the x and y directions. Calculations also had to be done to be sure the design would be able to withstand any loads or outside sources of stress. After the calculations proved the design to be ready to withstand the requirements, the parts were ordered or fabricated, as required. This helped me understand the full process of jobs sent to the Prototype Development Lab.

  17. Estimating slash pine biomass using radar backscatter

    Science.gov (United States)

    Hussin, Yousif Ali; Reich, Robin M.; Hoffer, Roger M.

    1991-01-01

    L-band HV multiple-incidence-angle aircraft synthetic aperture radar (SAR) data were analyzed in relation to average stand biomass, basal area, and tree height for 55 slash pine plantations located in northern Florida. This information was used to develop a system of equations to predict average stand biomass as a function of L-band (24.5-cm) radar backscatter. The system of equations developed in this study using three-stage least-squares and combinatorial screening accounted for 97 percent of the variability observed in average stand biomass per hectare. When applied to an independent data set, the biomass equations had an average bias of less than 1 percent with a standard error of approximately 3 percent. These results indicate that future Shuttle Imaging Radar Systems (e.g., SIR-C, which will have cross-polarized radar sensors) should be able to obtain better estimates of forest biomass than were obtained with previous satellite radar missions, which utilized only HH-polarized SAR data.

  18. BETA-S, Multi-Group Beta-Ray Spectra

    International Nuclear Information System (INIS)

    1 - Description of program or function: BETA-S calculates beta-decay source terms and energy spectra in multigroup format for time-dependent radionuclide inventories of actinides, fission products, and activation products. Multigroup spectra may be calculated in any arbitrary energy-group structure. The code also calculates the total beta energy release rate from the sum of the average beta-ray energies as determined from the spectral distributions. BETA-S also provides users with an option to determine principal beta-decaying radionuclides contributing to each energy group. The CCC-545/SCALE 4.3 (or SCALE4.2) code system must be installed on the computer before installing BETA-S, which requires the SCALE subroutine library and nuclide-inventory generation from the ORIGEN-S code. 2 - Methods:Well-established models for beta-energy distributions are used to explicitly represent allowed, and 1., 2. - and 3. -forbidden transition types. Forbidden non-unique transitions are assumed to have a spectral shape of allowed transitions. The multigroup energy spectra are calculated by numerically integrating the energy distribution functions using an adaptive Simpson's Rule algorithm. Nuclide inventories are obtained from a binary interface produced by the ORIGEN-S code. BETA-S calculates the spectra for all isotopes on the binary interface that have associated beta-decay transition data in the ENSDF-95 library, developed for the BETA-S code. This library was generated from ENSDF data and contains 715 materials, representing approximately 8500 individual beta transition branches. 3 - Restrictions on the complexity of the problem: The algorithms do not treat positron decay transitions or internal conversion electrons. The neglect of positron transitions in inconsequential for most applications involving aggregate fission products, since most of the decay modes are via electrons. The neglect of internal conversion electrons may impact on the accuracy of the spectrum in the low

  19. Backscatter B [USGS]--Offshore of Ventura, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3254 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3254) of the Offshore Ventura map area, California. The raster data...

  20. Backscatter A [CSUMB]--Offshore of Ventura, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3254 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3254) of the Offshore of Ventura map area, California. The raster...

  1. Backscatter B [USGS]--Offshore of Carpinteria, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3261 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3261) of the Offshore of Carpinteria map area, California. The raster...

  2. Backscatter A [CSUMB]--Offshore of Carpinteria, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3261 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3261) of the Offshore of Carpinteria map area, California. The raster...

  3. Backscatter A [CSUMB]--Offshore of Santa Barbara, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3281 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3281) of the Offshore of Santa Barbara map area, California. The...

  4. Reson 8101 multibeam backscatter data from Galvez Bank.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the Mariana archipelago between the U.S. Territory of Guam and Farallon De Pajaros Island in the...

  5. Bathymetry and Acoustic Backscatter: Northern Santa Barbara Channel, Southern California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This report presents bathymetry and acoustic backscatter data collected in July 2008 in the northern Santa Barbara Channel, California, using a bathymetric sidescan...

  6. An algorithm to determine backscattering ratio and single scattering albedo

    Digital Repository Service at National Institute of Oceanography (India)

    Suresh, T.; Desa, E.; Matondkar, S.G.P.; Mascarenhas, A.A.M.Q.; Nayak, S.R.; Naik, P.

    Algorithms to determine the inherent optical properties of water, backscattering probability and single scattering albedo at 490 and 676 nm from the apparent optical property, remote sensing reflectance are presented here. The measured scattering...

  7. LIDAR for atmospheric backscatter and temperature measurements Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objectives of this effort are to measure atmospheric backscatter profiles and temperature using a zenith looking lidar, designed for a small lander.The lidar...

  8. Photoelectron backscattering from silicon anodes of hybrid photodetector tubes

    CERN Document Server

    D'Ambrosio, C

    2000-01-01

    The impact of photoelectron backscattering on spectral distributions measured with hybrid photodetector tubes has been calculated. The calculations are based on the backscattering coefficient mu , the average number of photoelectrons N/sub phel/ emitted from the photocathode, and on the distribution of the fractional photoelectron energy q absorbed in silicon during the backscattering process. We obtained the following results: the average number of absorbed (measured) photoelectrons N/sub meas/ in the silicon anode amounts to ~88% of the incident N/sub phel/. Photoelectron- and gamma-absorption peaks are broadened by a factor 1.043 due to backscattering. As an example, for photomultiplier tubes, this broadening can amount to an average factor of 1.18 due to statistic and gain fluctuations on the dynode chain. (15 refs).

  9. Detection of buried landmine with X-ray backscatter technique

    Science.gov (United States)

    Yuk, Sunwoo; Kim, Kwang Hyun; Yi, Yun

    2006-11-01

    We describe a continuously operating scanning X-ray imaging system developed for landmine detection based on a backscatter X-ray principle, thus detection is done from the same side as the source. The source operates at 120 kV p and 3 mA. To study the physics of Compton X-ray backscattering, the photon transport factor, backscatter factor (BSF) and backscatter probability (BSP) were simulated using Monte-Carlo calculations using the generalized particle transport program MCNP. Based on the Monte-Carlo analyses results, a mine detecting system has been designed. It potentially has a low false alarm rate and a high detection probability, and a direct imaging facility.

  10. Detection of buried landmine with X-ray backscatter technique

    Energy Technology Data Exchange (ETDEWEB)

    Yuk, Sunwoo [Department of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)]. E-mail: sunwoo@korea.ac.kr; Kim, Kwang Hyun [Chosun University, 375, Seosuk-Dong, Dong-Gu, Gwangju (Korea, Republic of); Yi, Yun [Department of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)

    2006-11-30

    We describe a continuously operating scanning X-ray imaging system developed for landmine detection based on a backscatter X-ray principle, thus detection is done from the same side as the source. The source operates at 120 kV p and 3 mA. To study the physics of Compton X-ray backscattering, the photon transport factor, backscatter factor (BSF) and backscatter probability (BSP) were simulated using Monte-Carlo calculations using the generalized particle transport program MCNP. Based on the Monte-Carlo analyses results, a mine detecting system has been designed. It potentially has a low false alarm rate and a high detection probability, and a direct imaging facility.

  11. Backscatter--Offshore of Refugio Beach Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3319 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3319) of Offshore Refugio Beach map area, California. The raster data...

  12. Reson 8101 Backscatter imagery of Penguin Bank, Molokai, Hawaii, USA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Backscatter imagery extracted from gridded bathymetry of Penguin Bank, Molokai, Hawaii, USA. These data provide almost complete coverage between 0 and 100 meters....

  13. Backscatter [8101]--Offshore of Monterey Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents 2-m-resolution Reson 8101 data for the acoustic-backscatter map of the Offshore of Monterey map area, California. These metadata...

  14. Backscatter [7125]-- Offshore of Monterey Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents 2-m-resolution Reson 7125 data for the acoustic-backscatter map of Offshore of Monterey map area, California. These metadata describe...

  15. Backscatter [Swath]-- Offshore of Monterey Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents 2-m-resolution SWATHPlus data for the acoustic-backscatter map of Offshore of Monterey map area, California. These metadata describe...

  16. Interlinking backscatter, grain size and benthic community structure

    Science.gov (United States)

    McGonigle, Chris; Collier, Jenny S.

    2014-06-01

    The relationship between acoustic backscatter, sediment grain size and benthic community structure is examined using three different quantitative methods, covering image- and angular response-based approaches. Multibeam time-series backscatter (300 kHz) data acquired in 2008 off the coast of East Anglia (UK) are compared with grain size properties, macrofaunal abundance and biomass from 130 Hamon and 16 Clamshell grab samples. Three predictive methods are used: 1) image-based (mean backscatter intensity); 2) angular response-based (predicted mean grain size), and 3) image-based (1st principal component and classification) from Quester Tangent Corporation Multiview software. Relationships between grain size and backscatter are explored using linear regression. Differences in grain size and benthic community structure between acoustically defined groups are examined using ANOVA and PERMANOVA+. Results for the Hamon grab stations indicate significant correlations between measured mean grain size and mean backscatter intensity, angular response predicted mean grain size, and 1st principal component of QTC analysis (all p response predicted mean grain size (r2 = 0.692; p response predicted grain size (p < 0.001), and QTC class (p = 0.009). Mean grain size (Clamshell) shows a significant difference between groups for mean backscatter (p = 0.001); other methods were not significant. PERMANOVA for the Hamon abundance shows benthic community structure was significantly different between acoustic groups for all methods (p ≤ 0.001). Overall these results show considerable promise in that more than 60% of the variance in the mean grain size of the Clamshell grab samples can be explained by mean backscatter or acoustically-predicted grain size. These results show that there is significant predictive capacity for sediment characteristics from multibeam backscatter and that these acoustic classifications can have ecological validity.

  17. Analysis of forest backscattering characteristics based on polarization coherence tomography

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    It is difficult to make an inventory of vertical profiles of forest structure parameters in field measurements.However,analysis and understanding of forest backscattering characteristics contribute to estimation and detection of forest vertical structure because of the close relationships between backscattering characteristics and structure parameters.The vertical structure function in the complex interferometric coherence definition,which represents the vertical variation of microwave scattering with the penetration depth at a point in the 2-D radar image and can be used to analyze the forest backscattering characteristics,can be reconstructed from polarization coherence tomography(PCT).Based on PCT,the paper analyzes the forest backscattering characteristics and explores the inherent relationship between the result of PCT and the forest structure parameters from numerical simulation of Random Volume over Ground model(RVoG),Polarimetric SAR interferometry(PolInSAR)simulation of forest scene and PolInSAR data at L-band of the test site Traunstein.Firstly,the effects of the extinction coefficient and surface-to-volume scattering ratio in RVoG model on vertical backscattering characteristics are analyzed by means of numerical simulation.Secondly,by applying PCT to L-band POLInSAR simulations of forest scene,different variations of vertical backscattering due to different extinction coefficients and the ratios of surface-to-volume scattering resulting from different polarizations,forest types and densities are displayed and analyzed.Then a concept of relative average backscattering intensity is presented,and the factors which affect its vertical distribution are also discussed.Preliminary results show that there is high sensitivity of the vertical distribution of forest relative average backscattering intensity to the polarization,forest type and density.Finally,based on repeat pass DLR E-SAR L-band airborne POLInSAR data,the capability of PCT technology for detection

  18. Ultrasonic Backscattering from Suspended Erythrocytes: Dependence on Frequency and Size.

    Science.gov (United States)

    Kuo, Ihyuan

    The ultrasonic scattering properties of blood have been intensively investigated since the echo signal from red blood cells carries abundant diagnostic information for the study of blood flow and blood properties in the vessels. Recently, ultrasound of frequency higher than 20 MHz has been implemented in intravascular imaging to obtain better images of the vessel wall. In this research measurements were extended to 30 MHz to better understand the effect of blood on the operation of these intravascular devices. The experimentally measured backscatter of saline suspended porcine erythrocytes for frequency up to 30 MHz agrees very well with the theoretical analysis which indicate that Rayleigh scattering is still valid below this frequency. The analysis utilize the T-matrix method to calculate the backscattering cross section of an erythrocyte modeled as a fluid sphere, disk, and biconcave disk. Measurements on the backscattering coefficients of porcine, bovine, and lamb erythrocytes reveal that the backscatter has a square dependence on cell volume. The cell size dependent backscatter is also analyzed via a continuum approach. It is found that the echo intensity of high frequency ultrasound suffers greatly from the attenuation. The dilemma may be solved by using a spherically focused transducer. An analysis of the focused beam reflected from a perfect planar reflector leads to the modification of the standard substitution method for the backscatter measurement since the "image source" theory is found to be inappropriate for the focused beam. Reflection of the focused beam near the focal point is described based on Huygens' principle. Experimental and theoretical results indicate that the backscatter is dependent upon the position of the scatterer and the geometry of the transducer if a focused beam is used. Since ultrasound velocity information is needed for scattering measurements, an innovative method for measuring the acoustic speed and the attenuation coefficient

  19. Aerosol Lidar for the Relative Backscatter Amplification Measurements

    Science.gov (United States)

    Razenkov, Igor A.; Banakh, Victor A.; Nadeev, Alexander I.

    2016-06-01

    Backscatter amplification presents only in a turbulent atmosphere, when the laser beam is propagates twice through the same inhomogeneities. We proposed technical solution to detect backscatter amplification. An aerosol micro pulse lidar with a beam expansion via receiving telescope was built to study this effect. Our system allows simultaneous detection of two returns from the same scattering volume: exactly on the axis of the laser beam and off the axis.

  20. Radar backscatter modelling of forests using a macroecological approach

    OpenAIRE

    Brolly, Matthew

    2012-01-01

    This thesis provides a new explanation for the behaviour of radar backscatter of forests using vegetation structure models from the field of macroecology. The forests modelled in this work are produced using allometry-based ecological models with backscatter derived from the parameterisation of a radiative transfer model. This work is produced as a series of papers, each portraying the importance of macroecology in defining the forest radar response. Each contribution does so b...

  1. A relationship between ultrasonic integrated backscatter and myocardial contractile function.

    OpenAIRE

    Wickline, S. A.; Thomas, L J; Miller, J.G.; Sobel, B E; J. E. Perez

    1985-01-01

    We have shown previously that the physiologic, mechanical cardiac cycle is associated with a parallel, cardiac cycle-dependent variation of integrated backscatter (IB). However, the mechanisms responsible are not known. The mathematical and physiological considerations explored in the present study suggest that the relationship between backscatter and myocardial contractile function reflects cyclic alterations in myofibrillar elastic parameters, with the juxtaposition of intracellular and ext...

  2. Aerosol Backscatter from Airborne Continuous Wave CO2 Lidars Over Western North America and the Pacific Ocean

    Science.gov (United States)

    Jarzembski, Maurice A.; Srivastava, Vandana; Rothermel, Jeffry

    1999-01-01

    Atmospheric aerosol backscatter, beta, variability gives a direct indication of aerosol loading. Since aerosol variability is governed by regional sources and sinks as well as affected by its transport due to meteorological conditions, it is important to characterize this loading at different locations and times. Lidars are sensitive instruments that can effectively provide high-resolution, large-scale sampling of the atmosphere remotely by measuring aerosol beta, thereby capturing detailed temporal and spatial variability of aerosol loading, Although vertical beta profiles are usually obtained by pulsed lidars, airborne-focused CW lidars, with high sensitivity and short time integration, can provide higher resolution sampling in the vertical, thereby revealing detailed structure of aerosol layers. During the 1995 NASA Multicenter Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission, NASA MSFC airborne-focused CW CO2 Doppler lidars, operating at 9.1 and 10.6-micrometers wavelength, obtained high resolution in situ aerosol beta measurements to characterize aerosol variability. The observed variability in beta at 9.1-micrometers wavelength with altitude is presented as well as comparison with some pulsed lidar profiles.

  3. Ionization gage

    International Nuclear Information System (INIS)

    An ionization manometer is proposed which contains a transducer consisting of an anode, a directly heated cathode and a collector, a power source, a cathode emission current stabilizer, an ionic current amplifier connected to a recorder, and a cathode emission current modulator. To increase the accuracy of measurements under conditions of vacuum evaporation of materials, the modulator has been designed to comprise a source of controlling electric unipolar pulses of a specified duration and frequency and a blocking device connected to the collector. The output of the source of controlling electric unipolar pulses is connected to the emission current stabilizer and to the second input of the blocking device whose output is connected to the ionic current amplifier. The amount of pressure exerted in the vacuum chamber is estimated from the magnitude of the variable constituent of the collector signal

  4. Discharge, gage height, and elevation of 100-year floods in the Hudson River basin, New York

    Science.gov (United States)

    Archer, Roger J.

    1978-01-01

    The flood discharge that may be expected to be equaled or exceeded on the average of once in 100 years (100-year flood) was computed by the log-Pearson Type-III frequency relation for 72 stations in the Hudson River basin. These discharges and, where available, their corresponding gage height and elevation above mean sea level are presented in tabular form. A short explanation of computation methods is included. The data are to be used as part of a federally funded study of the water resources and related land resources of the Hudson River basin. (Woodard-USGS)

  5. Development of a six component flexured two shell internal strain gage balance

    Science.gov (United States)

    Mole, P. J.

    1993-01-01

    The paper describes the development of a new wind tunnel balance designed to meet the load requirements of the new advanced aircraft. Based on the floating frame or two-shell concept, the Flexured Balance incorporates a separate axial element, thus allowing for higher load per unit diameter, reduced primary load interaction, and greater flexibility in load range selection. Described is the design process, fabrication, gaging, calibration results, and performance during tunnel testing of the first prototype balance. Supporting data and accuracies are provided.

  6. Development and Ground Testing of Direct Measuring Skin Friction Gages for High Enthalpy Supersonic Flight Tests

    OpenAIRE

    Smith, Theodore Brooke

    2001-01-01

    A series of direct-measuring skin friction gages were developed for a high-speed, high-temperature environment of the turbulent boundary layer in flows such as that in supersonic combustion ramjet (scramjet) engines, with a progression from free-jet ground tests to a design for an actual hypersonic scramjet-integrated flight vehicle. The designs were non-nulling, with a sensing head that was flush with the model wall and surrounded by a small gap. Thus, the shear force due to the flow along...

  7. 18 W/m2 Mockup for Defense High-Level Waste (Rooms A): In situ data report: Volume 1---Mechanical response gages (February 1985--June 1990)

    International Nuclear Information System (INIS)

    Data are presented from the 18 W/m2 Mockup for Defense High-Level Waste, a very large scale in situ test fielded underground at the Waste Isolation Pilot Plant (WIPP). These data include selected fielding information, test configuration, instrumentation activities, and comprehensive results from a large number of gages. The results in this report give measured data from the mechanical response gages, i.e., room closure gages, extensometers, and stress meters emplaced in the test. Construction of the test began in June 1984; gage data in this report cover the complete test duration, that is, to June 1990

  8. Development of a {sup 147}Pm source for beta-backscatter thickness gauge applications

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Manoj; Udhayakumar, J. [Radiopharmaceuticals Division, Bhabha Atomic Research Center, Radiological Laboratory, Trombay, Mumbai 400 085 (India); Nuwad, J.; Shukla, Rakesh; Pillai, C.G.S. [Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Dash, Ashutosh, E-mail: adash@barc.gov.i [Radiopharmaceuticals Division, Bhabha Atomic Research Center, Radiological Laboratory, Trombay, Mumbai 400 085 (India); Venkatesh, Meera [Radiopharmaceuticals Division, Bhabha Atomic Research Center, Radiological Laboratory, Trombay, Mumbai 400 085 (India)

    2011-03-15

    This paper describes a method for the preparation of {sup 147}Pm sources, utilized in the determination of graphite coating thickness on the inner surface of the zircaloy cladding tube of nuclear fuels. {sup 147}Pm was adsorbed on a limited surface area [1.5 mm ({phi})x2 mm (l)] of a cylindrical aluminum rod [1.5 mm ({phi})x10 mm (l)]. In brief, the selected tip area [1.5 mm ({phi})x2 mm (l)] was anodized at a current density of 15 mA/cm{sup 2} at 15 {sup o}C in 3 M.H{sub 2}SO{sub 4} for 2 h followed by immersion of this area in 10 {mu}L of {sup 147}Pm solution containing 37 MBq (1 mCi) of activity at pH 6.0 for 24 h. The radioactive area was subsequently covered with a thin layer of Polymethyl Methacrylate (PMMA) to prevent leaching of {sup 147}Pm from the source. The quantity of incorporated {sup 147}Pm activity was assayed in a calibrated ion chamber. Quality control tests were carried out to ensure nonleachability, uniform distribution of activity and stability of the sources.

  9. Strain-gage signal-conditioning system for use in the LCP

    International Nuclear Information System (INIS)

    A strain-gage signal-conditioning system, providing wide-band noise rejection and isolation from high voltages that occur during emergency coil discharges, has been developed and tested. The multichannel system combines double-shielded transformers, neutralizing networks, and bandpass filters (with commercial 3-kHz carrier amplifier modules to isolate the strain gages to 5000 V) eliminate thermoelectric effects, and provide a signal bandwidth of 200 Hz. Common-mode interference occurs primarily as a result of beat-note effects between the carrier and the superimposed noise at frequencies near the odd harmonics of the carrier. The common-mode rejection of the test circuit was measured to be 120 dB for noise at 2750 and 3250 Hz, 135 dB at 3 kHz, and 135 dB and better at the odd harmonics of 9 kHz and above. The system has been successfully used in strain measurements on the toroidal field coils of the ISX-B tokamak and will be used in the Large Coil Test Facility to monitor strains in the energized coil conductors

  10. Tide Gage Records of Two Large XIX Century Tsunamis Originated in South America

    Science.gov (United States)

    Barrientos, S. E.; Ward, S. N.

    2008-12-01

    Two large earthquakes took place in the later part of the XIX century in southern Peru and northern Chile, these are the August 13, 1868, and the May 9, 1877 (local time), events. Their estimated magnitudes are of the order of 9 rupturing contiguous segments of nearly 500 km each. Both of them accommodated the convergence between Nazca and South American plates producing large seafloor and coastal elevation changes generating significant tsunamis that affected most of the coastlines of the Pacific basin. Reported local runups reached 20 m. Both trans-pacific tsunamis were recorded at one tide gage in Fort Point, in the Presidio area of San Francisco Bay, California. Records at Sausalito (approximately 6 km away from Fort Point) for the 1877 event mimic the signal recorded at Fort Point. Here we report on the characteristics of these tide gage records and compare them to the recent record of the June 2001 Mw=8.4 earthquake that ruptured a fraction of the 1868 event. Numerical simulations of the tsunamis have been constructed. The area to the south of the 2001 event and north of Antofagasta - Tocopilla in Chile (17°S-22°S), has not been subjected to large earthquakes since the 1868-1877 sequence.

  11. Gage cookbook: Tools and techniques to measure stresses and motions on explosive experiments

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.W. [Sandia National Labs., Albuquerque, NM (United States). Applied Technology Dept.

    1996-01-01

    Tools and techniques developed to measure stresses and motions on underground nuclear and high explosive tests in the tuff geologies at the Nevada Test Site are described in this document. The thrust of the measurements was to understand containment phenomenology. The authors concentrate on the fluid-coupled ytterbium gage; it was fielded to measure dynamic stress in the 0.2 to 20 kilobar range and the subsequent, low amplitude residual stress. Also described are accelerometer packages; their traces were integrated to obtain particle motion. Various cable survival techniques were investigated with field measurements for they wished to extend the measurements to late-time. Field measurements were also made to address the gage inclusion problem. Work to date suggests that the problem is a minimum when the stress level is above the yield strength of the host rock and grout. Below the yield level stress amplitudes in the grouted hole can range from 60 to 200% of the stress in the host rock.

  12. Stress Measurement around a Circular Role in a Cantilever Beam under Bending Moment Using Strain Gage and Reflective Photoelasticity

    International Nuclear Information System (INIS)

    It is necessary to study on the stress concentration experimentally, which is the main reason to avoid mechanical dilapidation and failure, when designing a mechanical structure. Stress concentration factor of a specimen of cantilever beam with a circular hole in the center was measured using both strain gage and photoelastic methods in this paper. In strain-gage measurement, three strain gages along the line near a hole of the specimen were installed and maximum strain was extrapolated from three measurements. In photoelastic measurement, two methods were employed. First, the Babinet-Soleil compensation method was used to measure the maximum strain. Secondly, photoelastic 4-step phase shilling method was applied to observe the strain distribution around the hole. Measurements obtained by different experiments were comparable within the range of experimental error

  13. Problems in use and security of measurement of high temperature strain gages at various temperature limits up to 10000C

    International Nuclear Information System (INIS)

    The examples given show the quality and use of manufacturers' data for a series of behaviour criteria for strain gages in the high temperature region. These results should not only be regarded critically. The manufacturer must appreciate that the very costly programme of investigations on the users' side represents a product development for large parts for the manufacturer of the strain gauges. It would therefore be desirable if these considerations were to initiate investigations on the manufacturer's part, in order to clear up the problematic are of the use of strain gages in the high temperature field, in order to provide the customer with more reliable and better strain gage characteristics for very expensive high temperature strain measurements. (orig.)

  14. Strain gages as a tool for experimental residual stress measurement. Dehnungsmessstreifen als Hilfsmittel zur experimentellen Ermittlung von Eigenspannungen

    Energy Technology Data Exchange (ETDEWEB)

    Keil, S.

    1989-09-01

    Residual stress in structural components can be experimentally determined with the aid of strain gages. Different experimental methods are available for this purpose which however all rely on the same principle of an external mechanical impact changing the inherent state of equilibrium of the component. The strain gages measure the relative elongation changes induced at the surface due to the new equilibrium state, and these data give information on the original residual stress in the workpiece. The article in hand describes the different methods that can be applied for inducing the desired change of equilibrium state and discusses practical examples. (orig.).

  15. MAGE-A1, GAGE and NY-ESO-1 cancer/testis antigen expression during human gonadal development

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Kock, Kirsten; Nielsen, Ole;

    2007-01-01

    BACKGROUND: Cancer/testis antigens (CTAs) are expressed in several cancers and during normal adult male germ cell differentiation. Little is known about their role in fetal development of human germ cells. METHODS: We examined expression of the CTAs MAGE-A1, GAGE and NY-ESO-1 in fetal gonads by...... cells and the staining intensity of all three CTAs peaked during the second trimester and gradually decreased towards birth in both male and female germ cells. In oocytes, MAGE-A1 expression terminated around birth, whereas NY-ESO-1 expression persisted through the neonatal stage and GAGE expression was...

  16. Electron backscattering from solid targets: Elastic scattering calculations

    International Nuclear Information System (INIS)

    Highlights: • Backscattering coefficient of low-energy electrons. • Elastic scattering cross sections. • Analytical expression of the numerical coefficient in the Nigam atomic screening factor. - Abstract: Analytical expression of the target atomic number dependence of the numerical coefficient in the Nigam atomic screening factor is proposed here to approximate the Rutherford elastic scattering cross sections for slow electron beams impinging on selected solid targets (from Be to Au) in the primary energy range 1–4 keV. Applications are then proposed in terms of Monte Carlo calculation of backscattering coefficient. In this respect, tabulations of backscattering coefficients are here reported for slow electrons in solid targets of interest pointing out a reasonable agreement with the data available in the literature. Analytical expressions of the target atomic number dependence of the electron backscattering coefficient is also suggested for selected electron primary energies ranging from 1 to 4 keV allowing thus an accurate determination of backscattering coefficients for low-energy electrons in solid targets without any resort in Monte Carlo type calculations

  17. Probabilities and statistics for backscatter estimates obtained by a scatterometer

    Science.gov (United States)

    Pierson, Willard J., Jr.

    1989-01-01

    Methods for the recovery of winds near the surface of the ocean from measurements of the normalized radar backscattering cross section must recognize and make use of the statistics (i.e., the sampling variability) of the backscatter measurements. Radar backscatter values from a scatterometer are random variables with expected values given by a model. A model relates backscatter to properties of the waves on the ocean, which are in turn generated by the winds in the atmospheric marine boundary layer. The effective wind speed and direction at a known height for a neutrally stratified atmosphere are the values to be recovered from the model. The probability density function for the backscatter values is a normal probability distribution with the notable feature that the variance is a known function of the expected value. The sources of signal variability, the effects of this variability on the wind speed estimation, and criteria for the acceptance or rejection of models are discussed. A modified maximum likelihood method for estimating wind vectors is described. Ways to make corrections for the kinds of errors found for the Seasat SASS model function are described, and applications to a new scatterometer are given.

  18. Coherent Thomson backscattering from laser-driven relativistic ultra-thin electron layers

    CERN Document Server

    Meyer-ter-Vehn, Jürgen

    2008-01-01

    The generation of laser-driven dense relativistic electron layers from ultra-thin foils and their use for coherent Thomson backscattering is discussed, applying analytic theory and one-dimensional particle-in-cell simulation. The blow-out regime is explored in which all foil electrons are separated from ions by direct laser action. The electrons follow the light wave close to its leading front. Single electron solutions are applied to initial acceleration, phase switching, and second-stage boosting. Coherently reflected light shows Doppler-shifted spectra, chirped over several octaves. The Doppler shift is found to be proportional to \\gamma_x^2=1/(1-\\beta_x^2), where \\beta_x is the electron velocity component in normal direction of the electron layer which is also the direction of the driving laser pulse. Due to transverse electron momentum p_y, the Doppler shift by 4*\\gamma_x^2=4*\\gamma^2/(1+(p_y/mc)^2) ~= 2*\\gamma is significantly smaller than full shift of 4*\\gamma^2. Methods to turn p_y -> 0 and to recove...

  19. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  20. BATS - Backscattering And Time-of-flight Spectrometer

    International Nuclear Information System (INIS)

    The new backscattering spectrometer IN16b will go into commissioning end 2011, providing in its final state about ten times higher count rate than its predecessor, IN16. Here we propose to increase its dynamic range by a factor of 7 with the TOF mode extension, BATS. This will make IN16b the leading high resolution backscattering spectrometer for incoherent quasi-elastic and inelastic neutron scattering; it will be competitive to the coarser resolution inverted geometry backscattering spectrometers that are being brought online at spallation sources. The increased dynamic range will extend the scope of science addressed on IN16b, generating considerable potential in fields such as the hydrogen economy (proton conduction, fuel cells, hydrogen storage), soft matter, biology and nano-science (nano-scale confinement, functionalized polymers). Such a large impact can be achieved using only a moderate investment. (authors)

  1. Ultrasonic Characterization of Tissues via Backscatter Frequency Dependence

    DEFF Research Database (Denmark)

    Stetson, Paul F.; Sommer, F.G.

    1997-01-01

    Phantom and patient studies were performed to assess the potential of backscatter frequency dependence as a useful parameter for tissue characterization. A commercial phased-array ultrasonic scanner was adapted to allow digitization of the intermediate-frequency ultrasonic data, Studies of agar...... phantoms containing polystyrene microspheres with 3.5 and 5 MHz transducers indicated the ability for robust differentiation of phantoms having different scatterer size and frequency dependence, based on calculated differences in mean frequencies of backscattered spectra, Using a 3,5-MHz probe......, significantly lower mean frequency of ultrasound backscattered from cirrhotic, compared to normal, liver tissue was noted, Studies of benign and malignant liver tumors (hemangiomas and metastases, respectively) indicated differences in frequency content of these tumors, compared to the adjacent normal liver...

  2. From Gaged to Ungaged- Predicting Long-term Environmental Flows, and Ecosystems Responses.

    Science.gov (United States)

    Sengupta, A.; Adams, S. K.; Stein, E. D.; Mazor, R.; Bledsoe, B. P.

    2015-12-01

    Modern management needs, such as water supply, quality, and ecosystem protection place numerous demands on instream flows. Many regions are interested in developing numeric flow criteria as a way of ensuring maintenance of flow patterns that protect biological resources while meeting other demands. Developing flow criteria requires the capacity to generate reliable time series of the daily flow at any stream reach of interest and to relate flow patterns to biological indicators of stream health. Most stream reaches are not gaged, and it is impractical to develop detailed models for all reaches where flow alteration needs to be evaluated. We present a novel mechanistic approach to efficiently predict flows and flow alteration at all ungaged stream locations within a region of interest. We used an "ensemble approach" whereby a series of regionally representative models were developed and calibrated. New sites of interest are assigned to one of the ensemble models based on similarity of catchment properties. For southern California, we selected 43 gaged sites representing the range of geomorphology, and watershed characteristics of streams in the region. For each gaged site, we developed a hydrologic model (HEC-HMS) to predict daily flows for a period representing dry, wet and normal precipitation. The final goal is to relate flow alterations to ecological responses, the models were calibrated to three separate performance metrics that reflect conditions important for instream biological communities- proportion of low flow days, flashiness and Nash Sutcliffe efficiency for overall model performance. We cross-validated the models using a "jack-knife" approach. Models were assigned to novel 840 bioassessment sites based on the results of a Random Forest model that identified catchment properties that most affected the runoff patterns. Daily flow data for existing and "reference conditions" was simulated for a 23-year period for current and reference (undeveloped

  3. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    .S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return of the...

  4. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward-...

  5. Bruce Thompson: Adventures and advances in ultrasonic backscatter

    Science.gov (United States)

    Margetan, Frank J.

    2012-05-01

    Over the course of his professional career Dr. R. Bruce Thompson published several hundred articles on non-destructive evaluation, the majority dealing with topics in ultrasonics. One longtime research interest of Dr. Thompson, with applications both to microstructure characterization and defect detection, was backscattered grain noise in metals. Over a 20 year period he led a revolving team of staff members and graduate students investigating various aspects of ultrasonic backscatter. As a member of that team I had the privilege of working along side Dr. Thompson for many years, serving as a sort of Dr. Watson to Bruce's Sherlock Holmes. This article discusses Dr. Thompson's general approaches to modeling backscatter, the research topics he chose to explore to systematically elucidate a better understanding of the phenomena, and the many contributions to the field achieved under his leadership. The backscatter work began in earnest around 1990, motivated by a need to improve inspections of aircraft engine components. At that time Dr. Thompson launched two research efforts. The first led to the heuristic Independent Scatterer Model which could be used to estimate the average grain noise level that would be seen in any given ultrasonic inspection. There the contribution from the microstructure was contained in a measureable parameter known as the Figure-of-Merit or FOM. The second research effort, spearheaded by Dr. Jim Rose, led to a formal relationship between FOM and details of the metal microstructure. The combination of the Independent Scattering Model and Rose's formalism provided a powerful tool for investigating backscatter in metals. In this article model developments are briefly reviewed and several illustrative applications are discussed. These include: the determination of grain size and shape from ultrasonic backscatter; grain noise variability in engine-titanium billets and forgings; and the design of ultrasonic inspection systems to improve defect

  6. Flux maximization techniques for compton backscatter depth profilometry.

    Science.gov (United States)

    Lawson, L

    1993-01-01

    Resolution in x-ray backscatter imaging has often been hampered by low fluxes. But, for a given set of resolution requirements and geometric constraints, it is possible to define a maximization problem in the geometric parameters for which the solution is the maximum flux possible in those circumstances. In this way, resolution in noncritical directions can be traded for improved resolution in a desired direction. Making this the thickness, or surface normal direction, makes practicable the depth profiling of layered structures. Such techniques were applied to the problem of imaging the layered structure of corroding aircraft sheet metal joints using Compton backscatter. PMID:21307450

  7. Probing Molecular Dynamics by Laser-Induced Backscattering Holography

    Science.gov (United States)

    Haertelt, Marko; Bian, Xue-Bin; Spanner, Michael; Staudte, André; Corkum, Paul B.

    2016-04-01

    We use differential holography to overcome the forward scattering problem in strong-field photoelectron holography. Our differential holograms of H2 and D2 molecules exhibit a fishbonelike structure, which arises from the backscattered part of the recolliding photoelectron wave packet. We demonstrate that the backscattering hologram can resolve the different nuclear dynamics between H2 and D2 with subangstrom spatial and subcycle temporal resolution. In addition, we show that attosecond electron dynamics can be resolved. These results open a new avenue for ultrafast studies of molecular dynamics in small molecules.

  8. Corrosion detection in aircraft by X-ray backscatter methods

    International Nuclear Information System (INIS)

    A limited-scan backscatter technique for detecting hidden corrosion and other flaws in aircraft has been demonstrated. Both simulation and experimental results indicate that as little as 5% material loss at depths up to 0.508 cm (0.200 in.) and 10% material loss at depths up to 0.635 cm (0.250 in.) beneath aircraft skin surfaces can be realiably detected. The technology involves analysis of backscattered photon data to yield a figure-of-merit whose value as a function of position indicates with high probability of detection whether or not flaws - such as corrosion, disbonding, macro-cracks, or voids - exist within scanned samples

  9. Coherent Effects in Microwave Backscattering Models for Forest Canopies

    Science.gov (United States)

    Saatchi, Sasan; McDonald, Kyle

    1995-01-01

    In modeling forest canopies, several scattering mechanisms are taken into account: 1) volume scattering, 2) surface-volume interaction, and 3) surface scattering from forest floor. Depending on the structural and dielectric characteristics of forest canopies, the relative contribution of each mechanism in the total backscatter signal of an imaging radar can vary. In this paper, two commonly used first order discrete scattering models, Distorted Born Approximation (DBA) and Radiative Transfer (RT) are used to simulate the backscattered power received by polarimetric radars at P-, L-, and C-bands over coniferous and deciduous forests. The difference between the two models resides on the coherent effect in the surface-volume interaction terms.

  10. Continuous water determination in NPK fertilizer liquor by controlling neutron moisture gage

    International Nuclear Information System (INIS)

    The principle is described of the neutron method for measuring fertilizer liquor moisture. The method is based on the slowing-down of fast neutrons in their transport through matter. The experimental neutron moisture gage system consists of a measuring sensor and an electronic evaluation unit. The sensor consists of an 241Am-Be fast neutron source having an activity of 11.1x109 Bq and of a proportional thermal neutron detector containing boron fluoride. The detector current signal is amplified by a preamplifier and is supplied by means of a coaxial cable to the input of the electronic evaluation unit. The variation is graphically shown of pulse rate with changes in fertilizer liquor moisture. (J.B.)

  11. Review of Trackside Monitoring Solutions: From Strain Gages to Optical Fibre Sensors

    Directory of Open Access Journals (Sweden)

    Georges Kouroussis

    2015-08-01

    Full Text Available A review of recent research on structural monitoring in railway industry is proposed in this paper, with a special focus on stress-based solutions. After a brief analysis of the mechanical behaviour of ballasted railway tracks, an overview of the most common monitoring techniques is presented. A special attention is paid on strain gages and accelerometers for which the accurate mounting position on the track is requisite. These types of solution are then compared to another modern approach based on the use of optical fibres. Besides, an in-depth discussion is made on the evolution of numerical models that investigate the interaction between railway vehicles and tracks. These models are used to validate experimental devices and to predict the best location(s of the sensors. It is hoped that this review article will stimulate further research activities in this continuously expanding field.

  12. Strain measurement technique for elevated temperature tensile and creep testing of foil-gage metals

    Science.gov (United States)

    Blackburn, L. B.

    1988-01-01

    This paper describes a strain measurement technique suitable for elevated-temperature tensile and creep testing of foil-gage metals, using a modified commonly available mechanical extensometer in conjunction with a displacement transducer. The extensometer was modified by attaching to it a counterbalance (to reduce the effect of the extensometer weight on the total maximum test load) and by incorporating a conical tip/flat-edge design (to minimize induced stresses in the specimen resulting from extensometer attachment). Creep tests were performed on 0.102-mm-thick specimens of Ti-6Al-4V at temperatures of 427 and 538 C, at nominal applied stresses of 310.3 and 172.4 MPa, respectively. Examination of the resulting creep curves suggested that the strain measurement system provided actual creep strain values with good accuracy.

  13. Review of Trackside Monitoring Solutions: From Strain Gages to Optical Fibre Sensors

    Science.gov (United States)

    Kouroussis, Georges; Caucheteur, Christophe; Kinet, Damien; Alexandrou, Georgios; Verlinden, Olivier; Moeyaert, Véronique

    2015-01-01

    A review of recent research on structural monitoring in railway industry is proposed in this paper, with a special focus on stress-based solutions. After a brief analysis of the mechanical behaviour of ballasted railway tracks, an overview of the most common monitoring techniques is presented. A special attention is paid on strain gages and accelerometers for which the accurate mounting position on the track is requisite. These types of solution are then compared to another modern approach based on the use of optical fibres. Besides, an in-depth discussion is made on the evolution of numerical models that investigate the interaction between railway vehicles and tracks. These models are used to validate experimental devices and to predict the best location(s) of the sensors. It is hoped that this review article will stimulate further research activities in this continuously expanding field. PMID:26287207

  14. Expression, purification and characterization of the cancer-germline antigen GAGE12I: a candidate for cancer immunotherapy

    DEFF Research Database (Denmark)

    Gjerstorff, Morten F; Besir, Hüseyin; Larsen, Martin R; Ditzel, Henrik J

    2010-01-01

    intracellular expression in yeast (Pichia pastoris) and nickel affinity, ion exchange and gel filtration purification. The identity of the purified protein was confirmed by mass spectrometry. This strategy yielded a total of 48 mg of highly pure (>98%) GAGE12I from 8 L of culture (6 mg/l). Interestingly, gel...

  15. Cost-effectiveness of the U.S. Geological Survey's stream-gaging programs in Massachusetts and Rhode Island

    Science.gov (United States)

    Gadoury, R.A.; Smath, J.A.; Fontaine, R.A.

    1985-01-01

    The report documents the results of a study of the cost-effectiveness of the U.S. Geological Survey 's continuous-record stream-gaging programs in Massachusetts and Rhode Island. Data uses and funding sources were identified for 91 gaging stations being operated in Massachusetts are being operated to provide data for two special purpose hydrologic studies, and they are planned to be discontinued at the conclusion of the studies. Cost-effectiveness analyses were performed on 63 continuous-record gaging stations in Massachusetts and 15 stations in Rhode Island, at budgets of $353,000 and $60,500, respectively. Current operations policies result in average standard errors per station of 12.3% in Massachusetts and 9.7% in Rhode Island. Minimum possible budgets to maintain the present numbers of gaging stations in the two States are estimated to be $340,000 and $59,000, with average errors per station of 12.8% and 10.0%, respectively. If the present budget levels were doubled, average standards errors per station would decrease to 8.1% and 4.2%, respectively. Further budget increases would not improve the standard errors significantly. (USGS)

  16. Quantum dots as mineral- and matrix-specific strain gages for bone biomechanical studies

    Science.gov (United States)

    Zhu, Peizhi; Xu, Jiadi; Morris, Michael; Ramamoorthy, Ayyalusamy; Sahar, Nadder; Kohn, David

    2009-02-01

    We report the use of quantum dots (Qdots) as strain gages in the study of bone biomechanics using solid state nuclear magnetic resonance (NMR) spectroscopy. We have developed solid state NMR sample cells for investigation of deformations of bone tissue components at loads up to several Mega Pascal. The size constraints of the NMR instrumentation limit the bone specimen diameter and length to be no greater than 2-3 mm and 30 mm respectively. Further, magic angle spinning (MAS) solid state NMR experiments require the use of non-metallic apparatus that can be rotated at kilohertz rates. These experimental constraints preclude the use of standard biomechanical measurement systems. In this paper we explore the use of quantum dot center of gravity measurement as a strain gage technology consistent with the constraints of solid state NMR. We use Qdots that bind calcium (625 nm emission) and collagen (705 nm emission) for measurement of strain in these components. Compressive loads are applied to a specimen in a cell through a fine pitch screw turned with a mini-torque wrench. Displacement is measured as changes in the positions of arrays of quantum dots on the surface of a specimen. Arrays are created by spotting the specimen with dilute suspensions of Qdots. Mineral labeling is achieved with 705 nm carboxylated dots and matrix labeling with 565 nm quantum dots conjugated to collagen I antibodies. After each load increment the new positions of the quantum dots are measured by fluorescence microscopy. Changes in Qdot center of gravity as a function of applied load can be measured with submicron accuracy.

  17. A Universal Tare Load Prediction Algorithm for Strain-Gage Balance Calibration Data Analysis

    Science.gov (United States)

    Ulbrich, N.

    2011-01-01

    An algorithm is discussed that may be used to estimate tare loads of wind tunnel strain-gage balance calibration data. The algorithm was originally developed by R. Galway of IAR/NRC Canada and has been described in the literature for the iterative analysis technique. Basic ideas of Galway's algorithm, however, are universally applicable and work for both the iterative and the non-iterative analysis technique. A recent modification of Galway's algorithm is presented that improves the convergence behavior of the tare load prediction process if it is used in combination with the non-iterative analysis technique. The modified algorithm allows an analyst to use an alternate method for the calculation of intermediate non-linear tare load estimates whenever Galway's original approach does not lead to a convergence of the tare load iterations. It is also shown in detail how Galway's algorithm may be applied to the non-iterative analysis technique. Hand load data from the calibration of a six-component force balance is used to illustrate the application of the original and modified tare load prediction method. During the analysis of the data both the iterative and the non-iterative analysis technique were applied. Overall, predicted tare loads for combinations of the two tare load prediction methods and the two balance data analysis techniques showed excellent agreement as long as the tare load iterations converged. The modified algorithm, however, appears to have an advantage over the original algorithm when absolute voltage measurements of gage outputs are processed using the non-iterative analysis technique. In these situations only the modified algorithm converged because it uses an exact solution of the intermediate non-linear tare load estimate for the tare load iteration.

  18. Assessment of the Uniqueness of Wind Tunnel Strain-Gage Balance Load Predictions

    Science.gov (United States)

    Ulbrich, N.

    2016-01-01

    A new test was developed to assess the uniqueness of wind tunnel strain-gage balance load predictions that are obtained from regression models of calibration data. The test helps balance users to gain confidence in load predictions of non-traditional balance designs. It also makes it possible to better evaluate load predictions of traditional balances that are not used as originally intended. The test works for both the Iterative and Non-Iterative Methods that are used in the aerospace testing community for the prediction of balance loads. It is based on the hypothesis that the total number of independently applied balance load components must always match the total number of independently measured bridge outputs or bridge output combinations. This hypothesis is supported by a control volume analysis of the inputs and outputs of a strain-gage balance. It is concluded from the control volume analysis that the loads and bridge outputs of a balance calibration data set must separately be tested for linear independence because it cannot always be guaranteed that a linearly independent load component set will result in linearly independent bridge output measurements. Simple linear math models for the loads and bridge outputs in combination with the variance inflation factor are used to test for linear independence. A highly unique and reversible mapping between the applied load component set and the measured bridge output set is guaranteed to exist if the maximum variance inflation factor of both sets is less than the literature recommended threshold of five. Data from the calibration of a six{component force balance is used to illustrate the application of the new test to real-world data.

  19. Expression of tumor-specific antigen MAGE, GAGE and BAGE in ovarian cancer tissues and cell lines

    Directory of Open Access Journals (Sweden)

    Yu Hao

    2010-04-01

    Full Text Available Abstract Background To observe mRNA expression of tumor-specific antigen MAGE, BAGE and GAGE in epithelial ovarian cancer tissues and cell lines, to explore the relationship between gene expression and diagnosis, treatment and prognosis of ovarian cancer, and to evaluate the feasibility of their gene products as markers, and an immunotherapy target for ovarian cancer. Methods mRNA expression of MAGE-1, MAGE-3, GAGE-1/2 and BAGE were determined by reverse transcription polymerase chain reaction (RT-PCR in 14 cases of normal ovarian tissue, 20 cases of ovarian benign tumor specimens, 41 cases of ovarian cancer specimens, and ovarian cancer cell lines SKOV3, A2780, and COC1. Results MAGE, GAGE and BAGE genes were not expressed in normal ovarian tissue. In benign tumors, only the MAGE gene was expressed; the expression rate of this gene in benign tumors was 15% (3/20. In ovarian cancer tissues, MAGE-1 and MAGE-3 was highly expressed, with expression rates of 53.7% (22/41 and 36.6% (15/41, while GAGE-1/2 and BAGE had relatively low expression, with rates of 26.8% (11/41 and 14.6% (6/41. In metastatic lesions of ovarian cancer, only MAGE-1 and BAGE were expressed, with expression rates of 28.6% (2/7 and 14.3% (1/7. The positive expression rates of MAGE-1 and MAGE-3 in serous cystadenocarcinoma were significantly higher than that in other types of ovarian cancer (P P Conclusion Tumor-specific antigen MAGE, BAGE and GAGE may play a role in the occurrence and development of ovarian cancer. These genes can be used as one of the important indicators for early diagnosis, efficacy evaluation and prognostic determination of ovarian cancer.

  20. About the origin of high-frequency ultrasonic backscattering signals

    International Nuclear Information System (INIS)

    Ultrasonic backscattering measurements allow to make a quick and nondestructive assessment of materials structures. As a qualitative assessment the homogeneity of structural states is determined, but also quantitative measurements are possible, like e.g. the determination of grain sizes in steels. But plottable measuring curves corresponding to the physically described interrelations will only be obtained as a result of a sufficiently large number (approx.= 1024) of averaging operations applied to equidirectional backscattering signals. The individual high-frequency signal is very strongly amplitude modulated. The signals required for averaging are obtained from different acoustic irradiation positions (position averaging), or by means of different center frequencies (frequency averaging). The present paper shows by means of numerical model calculations how the high-frequency backscattering signal is built up by superposition of the backscattering signals from all scattering objects lying in the acoustic beam. The improved understanding of the superposition of individual scattering processes opens up further opportunities of making a local structural analysis by means of ultrasonics. (orig.)

  1. Using Back-Scattering to Enhance Efficiency in Neutron Detectors

    OpenAIRE

    Kittelmann, Thomas; Klinkby, Esben; Cai, Xiao Xiao; Kanaki, Kalliopi; Cooper-Jensen, Carsten P.; Hall-Wilton, Richard

    2015-01-01

    The principle of using strongly scattering materials to recover efficiency in neutron detectors, via back-scattering of unconverted thermal neutrons, is discussed in general. Feasibility of the method is illustrated through Geant4-based simulations of a specific setup involving a moderator-like material placed behind a single layered boron-10 thin film gaseous detector.

  2. BACKSCATTER GUAGE DESCRIPTION FOR INSPECTION OF NEUTRON ABSORBER AND UNIFORMITY

    Energy Technology Data Exchange (ETDEWEB)

    Dewberry, R.; Gibbs, K.; Couture, A.

    2012-05-23

    This paper describes design, calibration, and testing of a dual He-3 detector neutron backscatter gauge for use in the Savannah River Site Mixed Oxide Fuel project. The gauge is demonstrated to measure boron content and uniformity in concrete slabs used in the facility construction.

  3. Coherent backscattering of light by cold atoms: theory meets experiment

    OpenAIRE

    Labeyrie, Guillaume; Delande, Dominique; Mueller, Cord A.; Miniatura, Christian; Kaiser, Robin

    2002-01-01

    Coherent backscattering (CBS) of quasi-resonant light by cold atoms presents some specific features due to the internal structure of the atomic scatterers. We present the first quantitative comparison between the experimentally observed CBS cones and Monte-Carlo calculations which take into account the shape of the atomic cloud as well as the internal atomic structure.

  4. Exploring backscattered imaging in low voltage FE-SEM

    OpenAIRE

    Lewis, P.; Micklethwaite, S.; Harrington, J; Dixon, M.; Brydson, R; Hondow, N

    2015-01-01

    Contrast levels in backscattered SEM images were investigated, utilising stage deceleration for low voltage imaging and also electron energy filtering. Image contrast variations are explained via use of Monte Carlo simulations which can predict the optimum accelerating and filter voltages for imaging complex sample mixtures.

  5. Characterization of a γ-backscattering imaging device

    Science.gov (United States)

    González, N.; Fajardo, E.; Blanco, W.; Cristancho, F.

    2012-02-01

    The Compton Camera is a γ-backscattering imaging device that allows us to obtain images of hidden objects. In order to evaluate the factors that affect the quality of those images, experiments were carried out to determine its response to different materials. Mathematical methods have been developed to quantify the image quality.

  6. Analysis of a proposed Compton backscatter imaging technique

    Science.gov (United States)

    Hall, James M.; Jacoby, Barry A.

    1994-03-01

    One-sided imaging techniques are currently being used in nondestructive evaluation of surfaces and shallow subsurface structures. In this work we present both analytical calculations and detailed Monte Carlo simulations aimed at assessing the capability of a proposed Compton backscattering imaging technique designed to detect and characterize voids located several centimeters below the surface of a solid.

  7. Backscatter C [Fugro]--Offshore of Coal Oil Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3302 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3302) of the Offshore of Coal Oil Point map area, California. The...

  8. Backscatter A [CSUMB]--Offshore Coal Oil Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3302 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3302) of the Offshore of Coal Oil Point map area, California. The...

  9. Backscatter B [USGS]--Offshore of Coal Oil Point, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of SIM 3302 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3302) of the Offshore of Coal Oil Point map area, California. The...

  10. Coherent backscattering of light by cold atoms: theory meets experiment

    International Nuclear Information System (INIS)

    Coherent backscattering (CBS) of quasi-resonant light by cold atoms presents some specific features due to the internal structure of the atomic scatterers. We present the first quantitative comparison between the experimentally observed CBS cones and Monte Carlo calculations which take into account the shape of the atomic cloud as well as the internal atomic structure. (authors)

  11. Backscatter gauge description for inspection of neutron absorber content

    Science.gov (United States)

    Dewberry, R. A.; Gibbs, K. M.; Couture, A. H.

    2013-05-01

    This paper describes design, calibration, and testing of a dual He-3 detector neutron backscatter gauge for use in the Savannah River Site Mixed Oxide Fuel project. The gauge is demonstrated to measure boron content and uniformity in concrete slabs used in the facility construction.

  12. Coherent backscattering of light by resonant atomic dipole transitions

    International Nuclear Information System (INIS)

    We study coherent backscattering (CBS) of resonant light by cold atomic vapors, both experimentally and theoretically. The theory predicts a drastic reduction of the CBS enhancement factor when a degenerate internal structure is present in the ground state. We test this prediction in experiments using different atoms and various transitions

  13. Source point calibration from an arbitrary electron backscattering pattern

    DEFF Research Database (Denmark)

    Lassen, Niels Christian Krieger

    1999-01-01

    Precise knowledge of the position of the source point is a requirement if electron backscattering patterns (EBSPs) are to be used for crystal orientation measurements or other types of measurements which demand a geometrical analysis of the patterns. Today, possibly the most popular method for...

  14. BackscatterB [Swath]--Offshore of Salt Point Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Salt Point map area, California. Backscatter data are provided as separate...

  15. BackscatterC [7125]--Offshore of Point Reyes Map Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Point Reyes map area, California. Backscatter data are provided as separate...

  16. BackscatterA [8101]--Offshore of Point Reyes Map Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Point Reyes map area, California. Backscatter data are provided as separate...

  17. BackscatterC [7125]--Offshore of Salt Point Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Salt Point map area, California. Backscatter data are provided as separate...

  18. BackscatterA [8210]--Offshore of Salt Point Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Salt Point map area, California. Backscatter data are provided as separate...

  19. BackscatterB [Swath]--Offshore of Point Reyes Map Map Area, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Point Reyes map area, California. Backscatter data are provided as separate...

  20. Super-virtual Interferometric Separation and Enhancement of Back-scattered Surface Waves

    KAUST Repository

    Guo, Bowen

    2015-08-19

    Back-scattered surface waves can be migrated to detect near-surface reflectors with steep dips. A robust surface-wave migration requires the prior separation of the back-scattered surface-wave events from the data. This separation is often difficult to implement because the back-scattered surface waves are masked by the incident surface waves. We mitigate this problem by using a super-virtual interferometric method to enhance and separate the back-scattered surface waves. The key idea is to calculate the virtual back-scattered surface waves by stacking the resulting virtual correlated and convolved traces associated with the incident and back-scattered waves. Stacking the virtual back-scattered surface waves improves their signal-to-noise ratio and separates the back-scattered surface-waves from the incident field. Both synthetic and field data results validate the robustness of this method.

  1. BackscatterA [USGS SWATH]--Monterey Canyon and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Monterey Canyon and Vicinity map area, California. Backscatter data are provided as separate...

  2. BackscatterD [CSUMB Swath]--Monterey Canyon and Vicinity, California

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This part of DS 781 presents data for the acoustic-backscatter map of Monterey Canyon and Vicinity map area, California. Backscatter data are provided as separate...

  3. Multibeam Backscatter Data for Selected U.S. Locations in the Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry for selected U.S. locations in the Pacific. The backscatter datasets include data collected using...

  4. Fiber optic backscatter spectroscopic sensor to monitor enamel demineralization and remineralization in vitro

    OpenAIRE

    Kishen, Anil; Shrestha, Annie; Rafique, Adeela

    2008-01-01

    In this study, a Fiber Optic Backscatter Spectroscopic Sensor (FOBSS) is used to monitor demineralization and remineralization induced changes in the enamel. A bifurcated fiber optic backscatter probe connected to a visible light source and a high resolution spectrophotometer was used to acquire the backscatter light spectrum from the tooth surface. The experiments were conducted in two parts. In Part 1, experiments were carried out using fiber optic backscatter spectroscopy on (1) sound enam...

  5. Expression of tumor-specific antigen MAGE, GAGE and BAGE in ovarian cancer tissues and cell lines

    International Nuclear Information System (INIS)

    To observe mRNA expression of tumor-specific antigen MAGE, BAGE and GAGE in epithelial ovarian cancer tissues and cell lines, to explore the relationship between gene expression and diagnosis, treatment and prognosis of ovarian cancer, and to evaluate the feasibility of their gene products as markers, and an immunotherapy target for ovarian cancer. mRNA expression of MAGE-1, MAGE-3, GAGE-1/2 and BAGE were determined by reverse transcription polymerase chain reaction (RT-PCR) in 14 cases of normal ovarian tissue, 20 cases of ovarian benign tumor specimens, 41 cases of ovarian cancer specimens, and ovarian cancer cell lines SKOV3, A2780, and COC1. MAGE, GAGE and BAGE genes were not expressed in normal ovarian tissue. In benign tumors, only the MAGE gene was expressed; the expression rate of this gene in benign tumors was 15% (3/20). In ovarian cancer tissues, MAGE-1 and MAGE-3 was highly expressed, with expression rates of 53.7% (22/41) and 36.6% (15/41), while GAGE-1/2 and BAGE had relatively low expression, with rates of 26.8% (11/41) and 14.6% (6/41). In metastatic lesions of ovarian cancer, only MAGE-1 and BAGE were expressed, with expression rates of 28.6% (2/7) and 14.3% (1/7). The positive expression rates of MAGE-1 and MAGE-3 in serous cystadenocarcinoma were significantly higher than that in other types of ovarian cancer (P < 0.05). Gene expression rate was not correlated with menopause or lymph node metastasis. Positive expression of MAGE-1 and MAGE-3 was positively correlated with tumor differentiation and the clinical stage of the ovarian cancer. In addition, the positive expression rate of BAGE was significantly higher in ovarian cancer patients with ascites (P < 0.05). The mRNA expression profiles of MAGE, GAGE and BAGE in ovarian carcinoma cell lines SKOV3, A2780 and COC1 varied, but there was at least one gene expressed in each cell line. Tumor-specific antigen MAGE, BAGE and GAGE may play a role in the occurrence and development of ovarian cancer

  6. Koedam {beta} factors revisited

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, J.E. [Physics Department, University of Wisconsin, Madison, WI (United States); Doughty, D.A. [Perkin-Elmer Optoelectronics, Santa Clara, CA (United States); Lister, G.G. [OSRAM SYLVANIA Inc., Beverly, MA (United States)

    2002-07-21

    A Koedam {beta} factor makes it possible to compute the total output power in line radiation from a positive column discharge using a single radiance measurement normal to an aperture in the wall. The results of analytic derivations of {beta} factors are presented for columns with uniform ({beta}=1.0) and parabolic ({beta}=0.75) excitation rates per unit volume and with negligible opacity. A Monte Carlo code for simulating radiation trapping with a spatially uniform density of absorbing atoms is then used to determine {beta} factors as a function of opacity. The code includes partial frequency redistribution and a Voigt line shape with radiative broadening, resonance collisional broadening, and Doppler broadening. The resulting {beta} factors are found to be nearly independent of opacity over a wide range of column radii for spectral line shapes dominated by Doppler broadening or by resonance collisional broadening. Additional Monte Carlo simulations are used to study {beta} factors as a function of a non-uniform density of absorbing atoms from radial cataphoresis with line shapes dominated by Doppler broadening, foreign gas broadening, and resonance collisional broadening. Radial cataphoresis is found to increase {beta} factors in all cases. Geometrical effects, refraction, and imperfect transmission at the glass wall are studied and found to decrease {beta} factors. (author)

  7. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  8. Detection and imaging in strongly backscattering randomly layered media

    International Nuclear Information System (INIS)

    Echoes from small reflectors buried in the heavy clutter are weak and difficult to distinguish from the medium backscatter. Detection and imaging with sensor arrays in such media require filtering out the unwanted backscatter and enhancing the echoes from the reflectors that we wish to locate. We consider a filtering and detection approach based on the singular value decomposition of the local cosine transform of the array response matrix. The algorithm is general and can be used for detection and imaging in the heavy clutter, but its analysis depends on the model of the cluttered medium. This paper is concerned with the analysis of the algorithm in finely layered random media. We obtain a detailed characterization of the singular values of the transformed array response matrix and justify the systematic approach of the filtering algorithm for detecting and refining the time windows that contain the echoes that are useful in imaging

  9. Model for H- and D- production by hydrogen backscattering

    International Nuclear Information System (INIS)

    The Marlowe Monte-Carlo backscattering code has been used to calculate particle reflection coefficients and energy distributions for H, D incident upon Li, K, Ni, Cu, Mo, Ag, Cs, Hf, W, Pt, and U surfaces. The backscattered energy and angular distributions are combined with a model for formation and survival probabilities for H-, D- leaving the surface. A least-squares fit of experimental measurements of H- yields from the composite surface, Cs/Cu, has been used to obtain two semi-empirical constants, α, β which enter into the formation and survival probabilities. These probabilities are used to calculate the production probability which in turn provides an upper limit to the negative ion yield. The choice of electrode material is discussed as a function of atomic number

  10. Radio-wave backscattering from artificial ionospheric turbulence

    International Nuclear Information System (INIS)

    The authors present the characteristics of shortwave signals, backscattered from artificial ionospheric inhomogeneities. The diagnostic equipment is located at a distance of about 100 km from the perturbing transmitter. The experimental results are interpreted on the basis of trajectory computations. The feasibility of investigating the inhomogeneous structure of the perturbed region obtained with the use of a high-power ionospheric station located at a small distance from the heater station is demonstrated. It is shown that the test wave signals backscattered by the perturbed region in the 5-10 MHz frequency range have appreciable amplitudes. The experiments showed that the region occupied by the artificial inhomogeneities extends to more than 50 km below the level of reflection of the heater wave

  11. RFID tag modification for full depth backscatter modulation

    Science.gov (United States)

    Scott, Jeffrey Wayne [Pasco, WA; Pratt, Richard M [Richland, WA

    2010-07-20

    A modulated backscatter radio frequency identification device includes a diode detector configured to selectively modulate a reply signal onto an incoming continuous wave; communications circuitry configured to provide a modulation control signal to the diode detector, the diode detector being configured to modulate the reply signal in response to be modulation control signal; and circuitry configured to increase impedance change at the diode detector which would otherwise not occur because the diode detector rectifies the incoming continuous wave while modulating the reply signal, whereby reducing the rectified signal increases modulation depth by removing the reverse bias effects on impedance changes. Methods of improving depth of modulation in a modulated backscatter radio frequency identification device are also provided.

  12. Theoretical Analysis of Rayleigh Backscattering Noise in Fiber Raman Amplifiers

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this paper, a new theoretical model for Rayleigh backscattering (RB) analysis of fiber Raman amplifiers is proposed. The model includes all the interactions among the pumps, signals, and all orders of RB. The results show that the higher order RB has a negligible influence on the performance of the amplifier. The co-propagating and counterpropagating RB power of the signal grow quadratically with the net-gain of the amplifier. The signal to double Rayleigh backscattering noise ratio (OSNRDRB ) of backward-pumped FRAs is better than that of the forward-pumped ones at high net-gain level (> 13 dB), while at low net-gain level the OSNRDrb of the forward-pumped FRAs is slightly better than that of the backward-pumped ones.

  13. Control of coherent backscattering by breaking optical reciprocity

    CERN Document Server

    Bromberg, Y; Popoff, S M; Cao, H

    2015-01-01

    Reciprocity is a universal principle that has a profound impact on many areas of physics. A fundamental phenomenon in condensed-matter physics, optical physics and acoustics, arising from reciprocity, is the constructive interference of quantum or classical waves which propagate along time-reversed paths in disordered media, leading to, for example, weak localization and metal-insulator transition. Previous studies have shown that such coherent effects are suppressed when reciprocity is broken. Here we show that by breaking reciprocity in a controlled manner, we can tune, rather than simply suppress, these phenomena. In particular, we manipulate coherent backscattering of light, also known as weak localization. By utilizing a non-reciprocal magneto-optical effect, we control the interference between time-reversed paths inside a multimode fiber with strong mode mixing, and realize a continuous transition from the well-known peak to a dip in the backscattered intensity. Our results may open new possibilities fo...

  14. Application of neutron backscatter techniques to level measurement problems

    International Nuclear Information System (INIS)

    We have designed and built portable level detectors and fixed level monitors based on neutron scattering and detection principles. The main components of these devices, which we call neutron backscatter gauges, are a neutron emitting radioisotope, a neutron detector, and a ratemeter. The gauge is a good detector for hydrogen but is much less sensitive to most other materials. This allows level measurements of hydrogen bearing materials, such as hydrocarbons, to be made through the walls of metal vessels. Measurements can be made conveniently through steel walls which are a few inches thick. We have used neutron backscatter gauges in a wide variety of level measurement applications encountered in the petrochemical industry. In a number of cases, the neutron techniques have proven to be superior to conventional level measurement methods, including gamma ray methods

  15. ILC Beam Energy Measurement by means of Laser Compton Backscattering

    CERN Document Server

    Muchnoi, N; Viti, M

    2008-01-01

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered $\\gamma$-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of $10^{-4}$ or bette...

  16. Characteristics of final particles in multiple Compton backscattering process

    Science.gov (United States)

    Potylitsyn, A.; Kol‘chuzhkin, A.

    2013-08-01

    An electron passing through a counter propagating intense laser beam can interact with a few laser photons with emission of a hard photon in each collision event. In contrast with the well-known nonlinear Compton backscattering process the above mentioned process may be named as multiple Compton backscattering process (MCBS). In this paper we have investigated the evolution of the electron energy distribution during MCBS process using Monte-Carlo (M-C) simulation. The main characteristics of such a distribution as mean energy and variance obtained by M-C technique were compared with analytical solutions of kinetic equations. We found the kinematic region where the analytical solutions are applicable with a good accuracy. A photon spectrum, even for the case when each electron emits one photon (in average) differs significantly from that described by the Klein-Nishina formula.

  17. Gamma-ray backscatter for body composition measurement.

    Science.gov (United States)

    Morgan, H M; Shakeshaft, J T; Lillicrap, S C

    1998-01-01

    The purpose of this study was to examine the potential of using backscatter information to assess regional body composition at selected sites. Two measurement techniques are examined: the measurement of the ratio of coherent to Compton scatter, and the measurement of the Compton scatter profile. Two possible applications are considered: the measurement of trabecular bone mineral density, and the measurement of the average fat/muscle ratio in a tissue volume. The results presented indicate that the analysis of coherent and Compton backscattered gamma-ray spectra from an 241Am source has the potential for measuring both trabecular bone mineral density and average fat/muscle ratio in a tissue volume, with a low absorbed dose to the subject. PMID:9569541

  18. Backscatter, anisotropy, and polarization of solar hard X-rays

    Science.gov (United States)

    Bai, T.; Ramaty, R.

    1978-01-01

    The problems of anisotropy, polarization, center-to-limb variation of the X-ray spectrum, and Compton backscatter are investigated in a study of solar hard X-rays. Effect of backscatter are found particularly important for anisotropic sources which emit hard X-rays predominantly toward the photosphere; for such anisotropic primary X-ray sources, the observed X-ray flux near 30 keV does not depend significantly on the position of the flare. In addition, the degree of polarization of the sum of the primary and reflected X-rays with energies in the 15 to 30 keV range may be as high as 30%. Determination of the height and anisotropy of the primary X-ray sources from study of the albedo patch is also discussed.

  19. Characteristics of Final Particles in Multiple Compton Backscattering Process

    CERN Document Server

    Potylitsyn, A

    2013-01-01

    An electron passing through a counter propagating intense laser beam can interact with a few laser photons with emission of a hard photon in each collision event. In contrast with the well-known nonlinear Compton backscattering process the above mentioned process may be named as multiple Compton backscattering process (MCBS). In this paper we have investigated the evolution of the electron energy distribution during MCBS process using Monte-Carlo (M-C) simulation. The main characteristics of such a distribution as mean energy and variance obtained by M-C technique were compared with analytical solutions of kinetic equations. We found the kinematic region where the analytical solutions are applicable with a good accuracy. A photon spectrum, even for the case when each electron emits one photon (in average) differs significantly from that described by the Klein-Nishina formula.

  20. Present State of Electron Backscatter Diffraction and Prospective Developments

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzer, R A; Field, D P; Adams, B L; Kumar, M; Schwartz, A J

    2008-10-24

    Electron backscatter diffraction (EBSD), when employed as an additional characterization technique to a scanning electron microscope (SEM), enables individual grain orientations, local texture, point-to-point orientation correlations, and phase identification and distributions to be determined routinely on the surfaces of bulk polycrystals. The application has experienced rapid acceptance in metallurgical, materials, and geophysical laboratories within the past decade (Schwartz et al. 2000) due to the wide availability of SEMs, the ease of sample preparation from the bulk, the high speed of data acquisition, and the access to complementary information about the microstructure on a submicron scale. From the same specimen area, surface structure and morphology of the microstructure are characterized in great detail by the relief and orientation contrast in secondary and backscatter electron images, element distributions are accessed by energy dispersive spectroscopy (EDS), wavelength dispersive spectroscopy (WDS), or cathodoluminescence analysis, and the orientations of single grains and phases can now be determined, as a complement, by EBSD.

  1. Stream gage descriptions and streamflow statistics for sites in the Tigris River and Euphrates River Basins, Iraq

    Science.gov (United States)

    Saleh, Dina K.

    2010-01-01

    Statistical summaries of streamflow data for all long-term streamflow-gaging stations in the Tigris River and Euphrates River Basins in Iraq are presented in this report. The summaries for each streamflow-gaging station include (1) a station description, (2) a graph showing annual mean discharge for the period of record, (3) a table of extremes and statistics for monthly and annual mean discharge, (4) a graph showing monthly maximum, minimum, and mean discharge, (5) a table of monthly and annual mean discharges for the period of record, (6) a graph showing annual flow duration, (7) a table of monthly and annual flow duration, (8) a table of high-flow frequency data (maximum mean discharge for 3-, 7-, 15-, and 30-day periods for selected exceedance probabilities), and (9) a table of low-flow frequency data (minimum mean discharge for 3-, 7-, 15-, 30-, 60-, 90-, and 183-day periods for selected non-exceedance probabilities).

  2. Inspection of reinforced concrete samples by Compton backscattering technique

    International Nuclear Information System (INIS)

    Reinforced concrete structures require frequent monitoring to ensure the concrete quality during its service life and for evaluation of in situ existing conditions. Compton backscattering of gamma rays is a nondestructive technique used for material characterization and detection of defects and inclusions in materials and can be employed on reinforced concrete. The methodology allows one-sided inspection of large structures, is relatively inexpensive and can be portable. The concept is based on detection of backscattered radiation produced from a collimated beam aimed at the sample. By measuring the spectrum of these scattered gamma rays it is possible to determine local density perturbations. In this work we used the Compton backscattering technique to locate and measure steel, defects and crushed stone inside concrete. The samples were irradiated with gamma rays from a Ø2 mm diameter collimated 241Am (100 mCi) source and the inelastically scattered photons were recorded at an angle of 135° by a high resolution CdTe semiconductor detector. Scanning was achieved by lateral movement of the sample blocks across the source and detector field of view in steps of 1 mm. A previous optimization of the experimental setup was performed with Monte Carlo simulation. The results showed that it was possible to locate inclusions and defects with Ø8 mm positioned at a depth of 20 mm below the surface of the sample. It was observed that aggregates such as crushed stone could mask defects at specific points due to high attenuation of the incident and scattered beam. - Highlights: ► Compton Backscattering was used to inspect reinforced concrete samples. ► The positioning of rebars, defects and crushed stone was achieved. ► High attenuation presented by crushed stone can mask defects at specific points

  3. Conservation of energy in coherent backscattering of light

    OpenAIRE

    Fiebig, Susanne; Aegerter, Christof M.; Bührer, Wolfgang; Störzer, Martin; Akkermans, Eric; Montambaux, Gilles; Maret, Georg

    2008-01-01

    Although conservation of energy is fundamental in physics, its principles seem to be violated in the field of wave propagation in turbid media by the energy enhancement of the coherent backscattering cone. In this letter we present experimental data which show that the energy enhancement of the cone is balanced by an energy cutback at all scattering angles. Moreover, we give a complete theoretical description, which is in good agreement with these data. The additional terms needed to enforce ...

  4. ILC Beam Energy Measurement by means of Laser Compton Backscattering

    OpenAIRE

    Muchnoi, N.; Schreiber, H. J.; Viti, M

    2008-01-01

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered $\\gamma$-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitiv...

  5. Electron backscattering rates of light elements in Moliere approximation

    International Nuclear Information System (INIS)

    Electron backscattering rates of light elements (atomic number Z = 6, 13, 29) are evaluated for electron energies of E = 20 ... 60 keV. The scattering amplitude in Moliere approximation is expanded as a series. The series elements are calculated in closed form with the aid of substitute functions. By comparison with the first Born approximation this yields correction factors of 1 ... 1,25. (orig.) 891 WBU

  6. Combined backscatter and transmission method for nuclear density gauge

    OpenAIRE

    Golgoun Seyed Mohammad; Sardari Dariush; Sadeghi Mahdi; Ebrahimi Mohammad; Aminipour Mojtaba; Davarpanah Mohammad Reza

    2015-01-01

    Nowadays, the use of nuclear density gauges, due to the ability to work in harsh industrial environments, is very common. In this study, to reduce error related to the ρ of continuous measuring density, the combination of backscatter and transmission are used simultaneously. For this reason, a 137Cs source for Compton scattering dominance and two detectors are simulated by MCNP4C code for measuring the density of 3 materials. Important advantages of this combined radiometric gauge are diminis...

  7. Proton - deuteron elastic backscattering in the resonance region

    International Nuclear Information System (INIS)

    In order to explain the proton - deuteron backscattering cross section, which show one peak for the incident proton kinetic energy at 600 MeV, the contribution of the Feynman diagram is calculated for the double pion exchange mechanism. This is due to the fact that the observed peak is exactly in the region where the Δ(1232) resonance can be excited in the πN-πN. (L.C.)

  8. Valley-protected backscattering suppression in silicon photonic graphene

    CERN Document Server

    Chen, Xiao-Dong

    2016-01-01

    In this paper, we study valley degree of freedom in all dielectric silicon photonic graphene. Photonic band gap opening physics under inversion symmetry breaking is revisited by the viewpoint of nonzero valley Chern number. Bulk valley modes with opposite orbital angular momentum are unveiled by inspecting time-varying electric fields. Topological transition is well illustrated through photonic Dirac Hamiltonian. Valley dependent edge states and the associated valley-protected backscattering suppression around Z-shape bend waveguide have been demonstrated.

  9. Double beta decay experiments

    OpenAIRE

    Barabash, A. S.

    2011-01-01

    The present status of double beta decay experiments is reviewed. The results of the most sensitive experiments are discussed. Proposals for future double beta decay experiments with a sensitivity to the $$ at the level of (0.01--0.1) eV are considered.

  10. Negative Beta Encoder

    CERN Document Server

    Kohda, Tohru; Aihara, Kazuyuki

    2008-01-01

    A new class of analog-digital (A/D), digital-analog (D/A) converters as an alternative to conventional ones, called $\\beta$-encoder, has been shown to have exponential accuracy in the bit rates while possessing self-correction property for fluctuations of amplifier factor $\\beta$ and quantizer threshold $\

  11. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for...

  12. Flight Test Results from the Rake Airflow Gage Experiment on the F-15B Airplane

    Science.gov (United States)

    Frederick, Michael A.; Ratnayake, Nalin A.

    2011-01-01

    The Rake Airflow Gage Experiment involves a flow-field survey rake that was flown on the Propulsion Flight Test Fixture at the NASA Dryden Flight Research Center using the Dryden F-15B research test bed airplane. The objective of this flight test was to ascertain the flow-field angularity, local Mach number profile, total pressure distortion, and dynamic pressure at the aerodynamic interface plane of the Channeled Centerbody Inlet Experiment. This new mixed-compression, supersonic inlet is planned for flight test in the near term. Knowledge of the flow-field characteristics at this location underneath the airplane is essential to flight test planning and computational modeling of the new inlet, anairplane, flying at a free-stream Mach number of 1.65 and a pressure altitude of 40,000 ft, would achieve the desired local Mach number for the future inlet flight test. Interface plane distortion levels of 2 percent and a local angle of attack of -2 deg were observed at this condition. Alternative flight conditions for future testing and an exploration of certain anomalous data also are provided.

  13. Dynamic testing of POSI-SEAL motor-operated butterfly valves using strain gages

    International Nuclear Information System (INIS)

    Utilities operating nuclear power plants recognize that the correct functioning of all motor-operated valves, and particularly those in safety-related systems, is of paramount importance. The U.S. Nuclear Regulatory Commission has issued Generic Letter 89-10 relative to this concern. Operability must be demonstrated under design-basis conditions. In order to demonstrate operability of motor-operated butterfly valves, the valve stem torque must be determined. The valve stem torque is a function of seat material, stem packing, stem bearing friction, and hydrodynamic lift and drag. The total valve operating hydrodynamic torque can be predicted using the valve manufacturer's data and the differential pressure. In order to validate the valve manufacturer's data, the actual total valve hydrodynamic torque is measured using strain gages mounted directly on the valve stem. This paper presents the results of comparing the predicted total valve operating hydrodynamic torque with the actual total valve operating hydrodynamic torque for six POSI-SEAL Class 150 high performance butterfly valves

  14. The effects of changes in loblolly pine biomass and soil moisture on ERS-1 SAR backscatter

    International Nuclear Information System (INIS)

    For young (< 15 years old) loblolly pine stands at Duke Forest (North Carolina, USA), when the ground was wet, the observed ERS-1 SAR backscatter from short-grass fields of 0.05 kg/m 2 biomass was >~ the backscatter from the stands, and there was no significant correlation between the backscatter and biomass (r2 = 0.19). Under dry soil conditions, the backscatter increased about 2-3 dB as the biomass increased from 0.05 kg/m2 to about 0.5- 1.5 kg/m ~, and the backscatter may be saturated near a 0.5-1.5 kg / m ~ biomass level. The correlation coefficient between the backscatter and biomass was r2 = 0.46. When the Santa Barbara microwave canopy backscatter model was applied to simulate the ERS-1 SAR backscatter from the stands over dry ground, modeled and observed backscatter had similar trends with increasing biomass. For these stands, sensitivity analyses using the model showed that as the surface-soil moisture increased, the major contributor to the total backscatter was changed from canopy volume scattering to surface backscatter between 0.4 kg / m2 and about I kg/m2. Signal saturating at low standing biomass and high sensitivity to soil moisture conditions limit the value of a short-wave (C-band) and steep local incidence angle (23 °) microwave sensor such as the ERS-1 SAR for forest monitoring

  15. An adjusted location model for SuperDARN backscatter echoes

    Directory of Open Access Journals (Sweden)

    E. X. Liu

    2012-12-01

    Full Text Available The radars that form the Super Dual Auroral Radar Network (SuperDARN receive scatter from ionospheric irregularities in both the E- and F-regions, as well as the Earth's surface, either ground or sea. For ionospheric scatter, the current SuperDARN standard software considers a straight-line propagation from the radar to the scattering zone with an altitude assigned by a standard height model. The knowledge of the group delay to a scatter volume is not sufficient for an exact determination of the location of the irregularities. In this study, the difference between the locations of the backscatter echoes determined by SuperDARN standard software and by ray tracing has been evaluated, using the ionosonde data collected at Sodankylä, which is in the field-of-view of Hankasalmi SuperDARN radar. By studying elevation angle information of backscattered echoes from the data sets of Hankasalmi radar in 2008, we have proposed an adjusted fitting location model determined by slant range and elevation angle. To test the reliability of the adjusted model, an independent data set is selected in 2009. The result shows that the difference between the adjusted model and the ray tracing is significantly reduced and the adjusted model could provide a more accurate location for backscatter targets.

  16. Inspection of reinforced concrete samples by Compton backscattering technique

    Science.gov (United States)

    Boldo, E. M.; Appoloni, C. R.

    2014-02-01

    Reinforced concrete structures require frequent monitoring to ensure the concrete quality during its service life and for evaluation of in situ existing conditions. Compton backscattering of gamma rays is a nondestructive technique used for material characterization and detection of defects and inclusions in materials and can be employed on reinforced concrete. The methodology allows one-sided inspection of large structures, is relatively inexpensive and can be portable. The concept is based on detection of backscattered radiation produced from a collimated beam aimed at the sample. By measuring the spectrum of these scattered gamma rays it is possible to determine local density perturbations. In this work we used the Compton backscattering technique to locate and measure steel, defects and crushed stone inside concrete. The samples were irradiated with gamma rays from a Ø2 mm diameter collimated 241Am (100 mCi) source and the inelastically scattered photons were recorded at an angle of 135° by a high resolution CdTe semiconductor detector. Scanning was achieved by lateral movement of the sample blocks across the source and detector field of view in steps of 1 mm. A previous optimization of the experimental setup was performed with Monte Carlo simulation. The results showed that it was possible to locate inclusions and defects with Ø8 mm positioned at a depth of 20 mm below the surface of the sample. It was observed that aggregates such as crushed stone could mask defects at specific points due to high attenuation of the incident and scattered beam.

  17. A backscattered x-ray imager for medical applications

    Science.gov (United States)

    Morris, Eric Jude L.; Dibianca, Frank A.; Shukla, Hemant; Gulabani, Daya

    2005-04-01

    Conventional X-ray radiographic systems rely on transmitted photons for the production of images. Backscatter imaging makes use of the more abundant scattered photons for image formation. Specifically, incoherently (Compton) scattered X-ray photons are detected and used for image formation in this modality of medical imaging. However, additional information is obtained when the transmitted X-ray photons are also detected and used. Transmission radiography produces a two-dimensional image of a three dimensional system, therefore image information from a shallower object is often contaminated by image information from underlying objects. Backscattered x-ray imaging largely overcomes this deficiency by imaging depth selectively, which reduces corruption of shallow imaging information by information from deeper objects lying under it. Backscattered x-ray imaging may be particularly useful for examining anatomical structures at shallow depths beneath the skin. Some typical applications for such imaging might be breast imaging, middle ear imaging, imaging of skin melanomas, etc. Previous investigations, by way of theoretical calculations and computational simulations into the feasibility of this kind of imaging have uncovered high-contrast and SNR parameters. Simulations indicate that this method can be used for imaging relatively high-density objects at depths of up to approximately five centimeters below the surface. This paper presents both theoretical and experimental SNR results on this new medical imaging modality.

  18. Simulation Studies of the Backscattering Signal in HSRL Technique

    CERN Document Server

    Georgakopoulou, Angelika

    2012-01-01

    The technique of High Spectral Resolution Lidar (HSRL) for atmospheric monitoring allows the determination of the aerosol to molecular ratio and can be used in UHECR Observatories using air fluorescence telescopes. By this technique a more accurate estimate of the Cherenkov radiation superimposed to the fluorescence signal can be achieved. A laboratory setup was developed to determine the backscattering coefficients using microparticles diluted in water and diffusion interfaces. In this setup we used a CW SLM laser at 532 nm and a 250 mm Newtonian telescope. Simulations of the above experimental configuration have been made using Scatlab\\c{opyright}, FINESSE\\c{opyright} 0.99.8 and MATLAB\\c{opyright} and are presented in this work. We compare the simulated 2-dimensional Fabry-Perot fringe images of the backscattering signal recorded in the CCD sensor with that of experimental ones. Additionally, we simulated the backscattering of the laser beam by the atmosphere at a height of 2000 m and we have studied the in...

  19. Relationships between multipolarized radar backscatter and slash pine stand parameters

    Science.gov (United States)

    Hussin, Yousif Ali; Hoffer, Roger M.

    1989-01-01

    Multipolarized L-band (24.5 cm) aircraft radar data was obtained for a primarily forested area in northern Florida. Based on the results of previous studies by Hoffer and Hussin (1989), a swath of medium incidence angle (35-25 deg) data was defined. Three groups of slash pine stands were located in the data: 4- to 17-year-old plantations, 18- to 48-year-old plantations, and 16- to 53-year-old natural stands. Stand data obtained from the forest-products companies operating in the area include age, tree height, diameter-at-breast height, basal area, volume (cords/acre), and density (trees/acre). Each of these stand parameters were compared to each of the four polarizations (HH, VV, VH, and HV) of the radar data for each group of stands. Statistically significant relationships were found between the radar backscatter and the forest stand parameters only for the 4- to 17-year-old slash pine plantation stands. In general, the cross-polarized radar backscatter was more highly correlated with the various stand parameters than the like-polarized backscatter, and the VV-polarized data were more highly correlated than the HH-polarized data.

  20. Selected Discharge Measurements at Stream-Gaging Stations on Lower Platte River near Ashland, Duncan, Leshara, Louisville, and North Bend, Nebraska, 1934-2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The accompanying "Lower_Platte_GAGES5" data release consists of two parts, a spatial data layer composed of a vector point data set representing five USGS...

  1. C-band backscattering characteristics of lake ice in northern Alaska during spring thaw period

    International Nuclear Information System (INIS)

    C-band backscatter intensities from lake ice in Northern Alaska showed a reversal phenomenon from freezing period to spring thaw period. The backscattering mechanisms of this phenomenon have not been clearly explained yet. In order to understand a mechanism of this backscatter reversal, we conducted field observations from April to May in 1997. This paper describes a summary of field observation data analysis and a derived assumption for the backscattering mechanism for the spring thaw period. The backscattering increase of the grounded ice is caused by a roughness increase of the ice surface, while backscattering decrease of the floating ice is by a presence of water film of the ice surface. By using the IEM surface scattering model, a validity of the assumed backscattering mechanisms is confirmed. (author)

  2. Multiple scattering wavelength dependent backscattering of kaolin dust in the IR: Measurements and theory

    Science.gov (United States)

    Ben-David, Avishai

    1992-01-01

    Knowing the optical properties of aerosol dust is important for designing electro-optical systems and for modeling the effect on propagation of light in the atmosphere. As CO2 lidar technology becomes more advanced and is used for multiwavelength measurements, information on the wavelength dependent backscattering of aerosol dust particles is required. The volume backscattering coefficient of aerosols in the IR is relatively small. Thus, only a few field measurements of backscattering, usually at only a few wavelengths, are reported in the literature. We present spectral field measurements of backscattering of kaolin dust in the 9-11 micron wavelength range. As the quantity of dust increases, multiple scattering contributes more to the measured backscattered signal. The measurements show the effect of the dust quantity of the spectral backscatter measurements. A simple analytical two stream radiative transfer model is applied to confirm the measurements and to give insight to the multiple scattering spectra of backscattering.

  3. Evaluation of a strain-gage load calibration on a low-aspect-ratio wing structure at elevated temperature

    Science.gov (United States)

    Reardon, Lawrence F.

    1989-01-01

    The environmental aspect of elevated temperature and its relationship to the science of strain gage calibrations of aircraft structures are addressed. A section of a wing designed for a high-speed aircraft structure was used to study this problem. This structure was instrumented with strain gages calibrated at both elevated and room temperatures. Load equations derived from a high-temperature load calibration were compared with equations derived from an identical load calibration at room temperature. The implications of the high temperature load calibration were studied from the viewpoint of applicability and necessity. Load equations derived from the room temperature load calibration resulted in generally lower equation standard errors than equations derived from the elevated temperature load calibration. A distributed load was applied to the structure at elevated temperature and strain gage outputs were measured. This applied load was then calculated using equations derived from both the room temperature and elevated temperature calibration data. It was found that no significant differences between the two equation systems existed in terms of computing this applied distributed load, as long as the thermal shifts resulting from thermal stresses could be identified. This identification requires a heating of the structure. Therefore, it is concluded that for this structure, a high temperature load calibration is not required. However, a heating of the structure is required to determine thermal shifts.

  4. Rapid synthesis of beta zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  5. Retrieving forest stand parameters from SAR backscatter data using a neural network trained by a canopy backscatter model

    International Nuclear Information System (INIS)

    It was possible to retrieve the stand mean dbh (tree trunk diameter at breast height) and stand density from the Jet Propulsion Laboratory (JPL) Airborne Synthetic Aperture Radar (AIRSAR) backscatter data by using threelayered perceptron neural networks (NNs). Two sets of NNs were trained by the Santa Barbara microwave canopy backscatter model. One set of the trained NNs was used to retrieve the stand mean dbh, and the other to retrieve the stand density. Each set of the NNs consisted of seven individual NNs for all possible combinations of one, two, and three radar wavelengths. Ground and multiple wavelength AIRSAR backscatter data from two ponderosa pine forest stands near Mt. Shasta, California (U.S.A.) were used to evaluate the accuracy of the retrievals. The r.m.s. and relative errors of the retrieval for stand mean dbh were 6.1 cm and 15.6 per cent for one stand (St2), and 3.1 cm and 6.7 per cent for the other stand (St11). The r.m.s. and relative errors of the retrieval for stand density were 71.2 treesha-1 and 23.0 per cent for St2, and 49.7 treesha-1 and 21.3 per cent for St11. (author)

  6. The Future of the Plate Boundary Observatory in the GAGE Facility and beyond 2018

    Science.gov (United States)

    Mattioli, G. S.; Bendick, R. O.; Foster, J. H.; Freymueller, J. T.; La Femina, P. C.; Miller, M. M.; Rowan, L.

    2014-12-01

    The Geodesy Advancing Geosciences and Earthscope (GAGE) Facility, which operates the Plate Boundary Observatory (PBO), builds on UNAVCO's strong record of facilitating research and education in the geosciences and geodesy-related engineering fields. Precise positions and velocities for the PBO's ~1100 continuous GPS stations and other PBO data products are used to address a wide range of scientific and technical issues across North America. A large US and international community of scientists, surveyors, and civil engineers access PBO data streams, software, and other on-line resources daily. In a global society that is increasingly technology-dependent, consistently risk-averse, and often natural resource-limited, communities require geodetic research, education, and infrastructure to make informed decisions about living on a dynamic planet. The western U.S. and Alaska, where over 95% of the PBO sensor assets are located, have recorded significant geophysical events like earthquakes, volcanic eruptions, and tsunami. UNAVCO community science provides first-order constraints on geophysical processes to support hazards mapping and zoning, and form the basis for earthquake and tsunami early warning applications currently under development. The future of PBO was discussed at a NSF-sponsored three-day workshop held in September 2014 in Breckenridge, CO. Over 40 invited participants and community members, including representatives from interested stakeholder groups, UNAVCO staff, and members of the PBO Working Group and Geodetic Infrastructure Advisory Committee participated in workshop, which included retrospective and prospective plenary presentations and breakout sessions focusing on specific scientific themes. We will present some of the findings of that workshop in order to continue a dialogue about policies and resources for long-term earth observing networks. How PBO fits into the recently released U.S. National Plan for Civil Earth Observations will also be

  7. Internships and UNAVCO: Training the Future Geoscience Workforce Through the NSF GAGE Facility

    Science.gov (United States)

    Morris, A. R.; MacPherson-Krutsky, C. C.; Charlevoix, D. J.; Bartel, B. A.

    2015-12-01

    Facilities are uniquely positioned to both serve a broad, national audience and provide unique workforce experience to students and recent graduates. Intentional efforts dedicated to broadening participation in the future geoscience workforce at the NSF GAGE (Geodesy Advancing Geosciences and EarthScope) Facility operated by UNAVCO, are designed to meet the needs of the next generation of students and professionals. As a university-governed consortium facilitating research and education in the geosciences, UNAVCO is well-situated to both prepare students for geoscience technical careers and advanced research positions. Since 1998, UNAVCO has offered over 165 student assistant or intern positions including engineering, data services, education and outreach, and business support. UNAVCO offers three formal programs: the UNAVCO Student Internship Program (USIP), Research Experiences in Solid Earth Science for Students (RESESS), and the Geo-Launchpad (GLP) internship program. Interns range from community college students up through graduate students and recent Masters graduates. USIP interns gain real-world work experience in a professional setting, collaborate with teams toward a common mission, and contribute their knowledge, skills, and abilities to the UNAVCO community. RESESS interns conduct authentic research with a scientist in the Front Range area as well as participate in a structured professional development series. GLP students are in their first 2 years of higher education and work alongside UNAVCO technical staff gaining valuable work experience and insight into the logistics of supporting scientific research. UNAVCO's efforts in preparing the next generation of scientists largely focuses on increasing diversity in the geosciences, whether continuing academic studies or moving into the workforce. To date, well over half of our interns and student assistants come from backgrounds historically underrepresented in the geosciences. Over 80% of former interns

  8. Beta-carotene

    Science.gov (United States)

    ... and deterioration of the lining of the mouth (oral mucositis). Taking beta-carotene by mouth doesn’t appear to prevent the development of oral mucositis during radiation therapy or chemotherapy. Pancreatic cancer. Taking ...

  9. Neutrinoless double beta decay

    International Nuclear Information System (INIS)

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given. (author)

  10. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  11. [High beta tokamak research

    International Nuclear Information System (INIS)

    Our activities on High Beta Tokamak Research during the past 20 months of the present grant period can be divided into six areas: reconstruction and modeling of high beta equilibria in HBT; measurement and analysis of MHD instabilities observed in HBT; measurements of impurity transport; diagnostic development on HBT; numerical parameterization of the second stability regime; and conceptual design and assembly of HBT-EP. Each of these is described in some detail in the sections of this progress report

  12. High beta multipoles

    International Nuclear Information System (INIS)

    Multipoles are being employed as devices to study fusion issues and plasma phenomena at high values of beta (plasma pressure/magnetic pressure) in a controlled manner. Due to their large volume, low magnetic field (low synchrotron radiation) region, they are also under consideration as potential steady state advanced fuel (low neutron yield) reactors. Present experiments are investigating neoclassical (bootstrap and Pfirsch-Schlueter) currents and plasma stability at extremely high beta

  13. Autoregressive conditional beta

    OpenAIRE

    Yunmi Kim

    2012-01-01

    The capital asset pricing model provides various predictions about equilibrium expected returns on risky assets. One key prediction is that the risk premium on a risky asset is proportional to the nondiversifiable market risk measured by the asset's beta coefficient. This paper proposes a new method for estimating and drawing inferences from a time-varying capital asset pricing model. The proposed method, which can be considered a vector autoregressive model for multiple beta coefficients, is...

  14. Concentration measurement of yeast suspensions using high frequency ultrasound backscattering.

    Science.gov (United States)

    Elvira, Luis; Vera, Pedro; Cañadas, Francisco Jesús; Shukla, Shiva Kant; Montero, Francisco

    2016-01-01

    This work proposes the use of an ultrasound based technique to measure the concentration of yeasts in liquid suspension. This measurement was achieved by the detection and quantification of ultrasonic echoes backscattered by the cells. More specifically, the technique was applied to the detection and quantification of Saccharomyces cerevisiae. A theoretical approach was proposed to get the average density and sound speed of the yeasts, which were found to be 1116 kg/m(3) and 1679 m/s, respectively. These parameters were needed to model the waves backscattered by each single cell. A pulse-echo arrangement working around 50 MHz, being able to detect echoes from single yeasts was used to characterize experimentally yeast solutions from 10(2) to 10(7)cells/ml. The Non-negative Matrix Factorization denoising technique was applied for data analysis. This technique required a previous learning of the spectral patterns of the echoes reflected from yeasts in solution and the base noise from the liquid medium. Comparison between pulse correlation (without denoising) and theoretical and experimental pattern learning was made to select the best signal processing. A linear relation between ultrasound output and concentration was obtained with correlation coefficient R(2)=0.996 for the experimental learning. Concentrations from 10(4) to 10(7)cells/ml were detected above the base noise. These results show the viability of using the ultrasound backscattering technique to detect yeasts and measure their concentration in liquid cultures, improving the sensitivity obtained using spectrophotometric methods by one order of magnitude. PMID:26361271

  15. HAB detection based on absorption and backscattering properties of phytoplankton

    Science.gov (United States)

    Lei, Hui; Pan, Delu; Bai, Yan; Chen, Xiaoyan; Zhou, Yan; Zhu, Qiankun

    2011-11-01

    The coastal area of East China Sea (ECS) suffers from the harmful algal blooms (HAB) frequently every year in the warm season. The most common causative phytoplankton algal species of HAB in the ECS in recent years are Prorocentrum donghaiense (dinoflagellates), Karenia mikimotoi (dinoflagellates which could produce hemolytic and ichthyotoxins) and Skeletonema costatum (diatom). The discrimination between the dinoflagellates and diatom HAB through ocean color remote sensing approach can add the knowledge of HAB events in ECS and help to the precaution. A series of in-situ measurement consisted of absorption coefficient, total scattering and particulate backscattering coefficient was conducted in the southern coast of Zhejiang Province in May 2009, and the estuary of Changjiang River in August 2009 and December 2010, which encountered two HAB events and a moderate bloom. The Inherent Optical Properties (IOPs) of the bloom waters have significant difference between phytoplankton species in absorption and backscattering properties. The chlorophyll a specific absorption coefficient (a*phy(λ)) for the bloom patches (chlorophyll a concentration >6mg m-3) differ greatly from the adjacent normal seawater, with the a*phy(λ) of bloom water lower than 0.03 m2 mg-1 while the a*phy(λ) of the adjacent normal seawater is much higher (even up to 0.06 m2 mg-1). Meanwhile, the backscattering coefficients at 6 wavebands (420, 442, 470, 510, 590 and 700nm) are also remarkably lower for bloom waters ( 0.02 m-1). The backscattering coefficient ratio (Rbp(λ)) is much lower for diatom bloom waters than for dinoflagellates types (0.01079 vs. 0.01227). A discrimination model based on IOPs is established, and several typical dinoflagellates and diatom bloom events including Prorocentrum donghaiense, Karenia mikimotoi and Skeletonema costatum in the ECS are picked out for testing with the MODIS-L2 and L3 ocean color remote sensing products from NASA website. The result proves that the

  16. The diurnal pattern of microwave backscattering by wheat

    International Nuclear Information System (INIS)

    A truck-mounted Ku-, C-, and L-band scatterometer system was used to obtain diurnal multiparameter radar backscatter measurements of wheat in August 1987 and June and July 1988. Concurrent field measurements of plant and soil moisture content were made in support of the radar data. Analyses of these data demonstrate the sensitivity of the microwave signals to the daily movement of water in the soil/plant system. The dependence of frequency, incidence angle, and polarization are discussed in relationship to the diurnal and seasonal changes in the soil and plant water content. The results are used to identify potential agronomic applications and future research requirements. (author)

  17. Development of landmine detection system by using backscattering neutron method

    International Nuclear Information System (INIS)

    Metal detector could not detect many kinds of Anti-Personal landmines which consist of plastic and explosive materials, for example TNT, RDX, etc, hence nuclear radiation detector, namely the gamma rays and neutron detectors, is prospect to be applied. One nuclear method for determining the landmine is measuring the backscattering neutron. The concept of radiation detection is detecting bulk material landmine which contains hydrogen, nitrogen, oxygen, and/or carbon by irradiating the soil with neutrons and detecting the gamma rays and neutron radiation that appears on the soil surface as a result from neutron-soil/target interaction. The development of landmine detection system has been proposed by using thermal backscattering neutron method. However, some difficulties are caused by the complexity of conditions, for example humidity, soil contents, density of each material of landmines and others. The purpose of this study is to setup a detection system with high efficiency for detecting the landmine by utilizing backscattering neutron method. Previously, the landmine detection experiment has been based on measuring the difference in the total counts of neutron in two cases, which are with and without melamine target. Nevertheless, a detection problem still remains in the case of deeply location target to the surface and humid cases due to the domination of hydrogen effect. In the present work, in order to detect as efficient as possible the existence of landmine inside the soil, two methods are applied simultaneously. First, the total counts measurements are performed, and then the determination of epithermal and fast backscattering neutrons effect is measured by using the 3He detector with Cadmium covered. In order to obtain the dominant effect of hydrogen in all energy ranges, the total neutron count will be conducted firstly. The total neutron counts measurement is suitable when higher content hydrogen exist in the landmines rather than in the soil. The

  18. Rutherford backscattering and Auger spectroscopy of mercuric iodide detectors

    Energy Technology Data Exchange (ETDEWEB)

    Felter, T.E.; Stulen, R.H. (Sandia National Labs., Livermore, CA (USA)); Schnepple, W.F.; Ortale, C.; Van den Berg, L. (EG and G Energy Measurements, Inc., Goleta, CA (USA). Santa Barbara Operations)

    1989-11-01

    Palladium contacts on mercuric iodide have been studied using Rutherford backscattering spectroscopy and Auger electron spectroscopy. Results on actual detector contacts show some intermixing of both mercury and iodine with the palladium. To investigate the role of processing variables as a possible cause of this effect we have fabricated model contacts at low temperatures (T {approx equal} 100 K) and analyzed in situ. The results demonstrated that significant interdiffusion occurs at temperatures as low as 225 K. We conclude that excessive heating during contact deposition could prove to be detrimental to device performance and that the use of cooled substrates during processing should be explored. (orig.).

  19. Rutherford backscattering and Auger spectroscopy of mercuric iodide detectors

    Science.gov (United States)

    Felter, T. E.; Stulen, R. H.; Schnepple, W. F.; Ortale, C.; van den Berg, L.

    1989-11-01

    Palladium contacts on mercuric iodide have been studied using Rutherford backscattering spectroscopy and Auger electron spectroscopy. Results on actual detector contacts show some intermixing of both mercury and iodine with the palladium. To investigate the role of processing variables as a possible cause of this effect we have fabricated model contacts at low temperatures (T ≈ 100 K) and analyzed in situ. The results demonstrated that significant interdiffusion occurs at temperatures as low as 225 K. We conclude that excessive heating during contact deposition could prove to be detrimental to device performance and that the use of cooled substrates during processing should be explored.

  20. Rutherford backscattering and Auger spectroscopy of mercuric iodide detectors

    International Nuclear Information System (INIS)

    Palladium contacts on mercuric iodide have been studied using Rutherford backscattering spectroscopy and Auger electron spectroscopy. Results on actual detector contacts show some intermixing of both mercury and iodine with the palladium. To investigate the role of processing variables as a possible cause of this effect we have fabricated model contacts at low temperatures (T ≅ 100 K) and analyzed in situ. The results demonstrated that significant interdiffusion occurs at temperatures as low as 225 K. We conclude that excessive heating during contact deposition could prove to be detrimental to device performance and that the use of cooled substrates during processing should be explored. (orig.)

  1. Backscattering from dental restorations and splint materials during therapeutic radiation

    International Nuclear Information System (INIS)

    Models were constructed to simulate as closely as possible the human oral cavity. Radiation absorbed doses were determined for controls and various test situations involving the presence of dental restorative and splint materials during cobalt-60 irradiation of the models. Adjacent gold full crowns and adjacent solid dental silver amalgam cores both increased the dose to the interproximal gingivae by 20%. Use of orthodontic full bands for splinting the jaws increased the dose to the buccal tissues by an average of 10%. Augmentation of dose through backscatter radiation was determined to be only slight for intracoronal amalgam fillings and stainless steel or plastic bracket splints

  2. Statistical Parameter Estimation in Ultrasound Backscattering from Tissue Mimicking Media.

    Science.gov (United States)

    Chen, Jian-Feng

    Several tissue characterization parameters, including the effective scatterer number density and the backscatter coefficient, were derived from the statistical properties of ultrasonic echo signals. The effective scatterer number density is the actual scatterer number density in a medium multiplied by a frequency-dependent factor that depends on the differential scattering cross-sections of all scatterers. The method described in this thesis for determining the scatterer number density explicitly retains both the temporal nature of the data acquisition and the properties of the ultrasound field in the data reduction. Moreover, it accounts for the possibility that different sets of scatterers may dominate the echo signal at different frequencies. The random processes involved in forming ultrasound echo signals from random media give rise to an uncertainty in the estimated effective scatterer number density. This uncertainty is evaluated using error propagation. The statistical uncertainty depends on the effective number of scatterers contributing to the segmented echo signal, increasing when the effective number of scatterers increases. Tests of the scatterer number density data reduction method and the statistical uncertainty estimator were done using phantoms with known ultrasound scattering properties. Good agreement was found between measured values and those calculated from first-principles. The properties of the non-Gaussian and non-Rayleigh parameters of ultrasound echo signals are also studied. Both parameters depend on the measurement system, including the transducer field and pulse frequency content, as well as on the medium's properties. The latter is expressed in terms of the scatterer number density and the second and fourth moments of the medium's scattering function. A simple relationship between the non-Gaussian and non-Rayleigh parameters is derived and verified experimentally. Finally, a reference phantom method is proposed for measuring the

  3. Combined backscatter and transmission method for nuclear density gauge

    Science.gov (United States)

    Golgoun, Seyed Mohammad; Sardari, Dariush; Sadeghi, Mahdi; Ebrahimi, Mohammad; Aminipour, Mojtaba; Davarpanah, Mohammad Reza

    2015-07-01

    Nowadays, the use of nuclear density gauges, due to the ability to work in harsh industrial environments, is very common. In this study, to reduce error related to the ρ of continuous measuring density, the combination of backscatter and transmission are used simultaneously. For this reason, a 137Cs source for Compton scattering dominance and two detectors are simulated by MCNP4C code for measuring the density of 3 materials. Important advantages of this combined radiometric gauge are diminished influence of μ and therefore improving linear regression.

  4. Combined backscatter and transmission method for nuclear density gauge

    Directory of Open Access Journals (Sweden)

    Golgoun Seyed Mohammad

    2015-01-01

    Full Text Available Nowadays, the use of nuclear density gauges, due to the ability to work in harsh industrial environments, is very common. In this study, to reduce error related to the ρ of continuous measuring density, the combination of backscatter and transmission are used simultaneously. For this reason, a 137Cs source for Compton scattering dominance and two detectors are simulated by MCNP4C code for measuring the density of 3 materials. Important advantages of this combined radiometric gauge are diminished influence of μ and therefore improving linear regression.

  5. Investigations of Temperature and Backscatter Correlation in the Dry Snow Zone of the Greenland Ice Sheet

    OpenAIRE

    Moon, Kevin R.; Long, David G.

    2012-01-01

    Due to system degradation, satellite-borne scatterometers require post-launch calibrations to maintain accuracy. The dry snow zone of the Greenland ice sheet has been used for calibration due to its relatively constant backscatter properties. However, we recently discovered that some of the variation in the dry snow zone backscatter is seasonal. This paper uses correlation analysis to investigate the relationship between temperature and backscatter in the dry snow zone. The correlation coeffi...

  6. Comparative modelling of X-ray backscattering in the Novillo tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Flores, A.; Castillo, A.; Barocio, S.R.; Chavez, E.; Melendez, L.; Cruz, G.J.; Olayo, M.G.; Gonzalez, P.; Azorin, J. E-mail: azorin@xanum.uam.mx

    2001-08-01

    Results of X-ray backscattering studies on the Novillo tokamak using thermoluminescent dosimeters (TLDs) are presented. Dose measurements were carried out on the equatorial plane of the tokamak along 12 radial directions. The backscattering can be due to the interaction of the radiation with the surrounding walls. Two kinds of phenomenological mathematical methods describing the X-ray backscattering were obtained from the experimental data and compared. Good agreement was found between the data and the predictions of the models.

  7. Multi-beam backscatter image data processing techniques employed to EM 1002 system

    Digital Repository Service at National Institute of Oceanography (India)

    Fernandes, W.A.; Chakraborty, B.

    backscatter intensities recorded in the raw (*.all) files are corrected during data acquisition for backscatter employing Lambert’s law (Simrad Model) [4]. However, for lower incidence angles (within the 0-25º) it was determined that the gain settings... of seabed during online data acquisition. Thus there will be image distortion, therefore, above correction is made during processing the raw backscatter strengths. • Lambert’s law removal: As discussed in preceding sections [4], the raw data is treated...

  8. Seabottom characterization using multibeam echosounder angular backscatter: An application of the composite roughness theory

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Schenke, H.W.; Kodagali, V.N.; Hagen, R.

    of the contributions from the surface rough- ness and volume inhomogeneities. For an interface backscattering strength within the composite roughness theory, Jackson et al. [1] had applied power law properties of the seafloor roughness spectrum to a Helmholtz...-Kirchhoff’s theory) is employed. A visual examination to observe the match between the theoretical and measured backscattering strengths is performed. In order to determine accurate, unbiased power law parameters, we have avoided using the backscattering strength...

  9. Effect of the Photon's Brownian Doppler Shift on the Weak-Localization Coherent-Backscattering Cone

    OpenAIRE

    Lesaffre, Max; Atlan, Michael; Gross, Michel

    2006-01-01

    We report the first observation of the dependence of the coherent-backscattering (CBS) enhanced cone with the frequency of the backscattered photon. The experiment is performed on a diffusing liquid suspension and the Doppler broadening of light is induced by the Brownian motion of the scatterers. Heterodyne detection on a CCD camera is used to measure the complex field (i.e., the hologram) of the light that is backscattered at a given frequency. The analysis of the holograms yield the freque...

  10. On some corrections to beta spectra measured by toroidal inron-free beta spectrometer

    International Nuclear Information System (INIS)

    In the investigations of the features of neutron-deficient isotopes to study low-intensity branches of positron decay ST-2 the iron-free beta spectrometer with toroidal magnetic field (light intensity approximately 20%, resolution ability approximately 1%) is used. The influence of the factors distorting β-spectra in case of the ST-2 spectrometer has been studied. In using the sources without the carriers the source thickness at Esub(β) > 100 keV doesn't distort the spectrum. The investigation of the dependence of 22Na positron counting at different energies on theckness of the substrate made it possible to determine the paremeters of backscattering. It was shown that the backgroud of the spectrometer in positron measuring regime at energies Esub(β) > 100 keV didn't depend on the energy. The measurements at the energies higher than maximum positron energy give directly the background value. According to experimental distribution of the lines of conversion electrons the analytical kind of response function of the spectrometer has been obtained. Spectral distribution of monochromatic electrons consists of the peak, described by Gauss distribution, and exponential ''tail'' in the direction of small energies. The investigations showed that with the help of the ST-2 beta spectrometer the decay positron btanches with the intensity up to 0.01% per decay may be determined with the accuracy 2-3 keV. There is principal possibility to study form factors of β-spectra

  11. The measurement of concrete density by back-scattered γ-radiation

    International Nuclear Information System (INIS)

    The use of γ backscattering techniques in the quality control of concrete are considered. The performance of an instrument using this technique, the Ekco N 711B, is reported. It was found that quick and accurate measurements could be obtained which were independent of the material chemical constitution and that good correlation existed between ultrasonic pulse velocity, and the backscatter methods. The disadvantage of measuring backscatter from thin concrete members was overcome by using a steel backing plate that compensated for the back-scatter if the concrete depth was less than the semi-infinite depth. (U.K.)

  12. Verification of terahertz-wave spectrophotometry by Compton backscattering of coherent synchrotron radiation

    Science.gov (United States)

    Sei, Norihiro; Takahashi, Toshiharu

    2014-01-01

    We developed a continuous-spectrum light beam from Compton backscattering by using coherent synchrotron radiation in an L-band linac at the Kyoto University Research Reactor Institute. The ratio of Compton backscattered photons to background photons when coherent synchrotron radiation was used was three times larger than when coherent transition radiation was used. The transmission spectrum of a polystyrene film in the terahertz-wave region was evaluated by measuring the spectrum of the Compton backscattered photons and it roughly agreed with that measured by a Martin-Puplett-type interferometer. The spectrophotometry using Compton backscattering shows promise as a new tool for investigations in terahertz-wave science.

  13. Transport equation theory of electron backscattering and x-ray production

    International Nuclear Information System (INIS)

    A transport equation theory of electron backscattering and x ray production is derived and applied to energy dissipation of 30-KeV electrons for copper as a function of depth and to the energy distribution of backscattered electrons for copper, aluminum, and gold. These results are plotted and compared with experiment. Plots for variations of backscattering with atomic number and with angle of incidence, and polar plots of backscattering for 30-keV electrons at normal incidence are also presented. 10 references, seven figures

  14. Data analysis of backscattering LIDAR system correlated with meteorological data

    International Nuclear Information System (INIS)

    In these last years, we had an increase in the interest in the monitoring of the effect of the human activity being on the atmosphere and the climate in the planet. The remote sensing techniques has been used in many studies, also related the global changes. A backscattering LIDAR system, the first of this kind in Brazil, has been used to provide the vertical profile of the aerosol backscatter coefficient at 532 nm up to an altitude of 4-6 km above sea level. In this study, data has was collected in the year of 2005. These data had been correlated with data of solar photometer CIMEL and also with meteorological data. The main results had indicated to exist a standard in the behavior of these meteorological data and the vertical distribution of the extinction coefficient gotten through LIDAR. In favorable periods of atmospheric dispersion, that is, rise of the temperature of associated air the fall of relative humidity, increase of the atmospheric pressure and low ventilation tax, was possible to determine with good precision the height of the Planetary Boundary Layer, as much through the vertical profile of the extinction coefficient how much through the technique of the vertical profile of the potential temperature. The technique LIDAR showed to be an important tool in the determination of the thermodynamic structure of the atmosphere, assisting to characterize the evolution of the CLP throughout the day, which had its good space and secular resolution. (author)

  15. Observations of HF backscatter decay rates from HAARP generated FAI

    Science.gov (United States)

    Bristow, William; Hysell, David

    2016-07-01

    Suitable experiments at the High-frequency Active Auroral Research Program (HAARP) facilities in Gakona, Alaska, create a region of ionospheric Field-Aligned Irregularities (FAI) that produces strong radar backscatter observed by the SuperDARN radar on Kodiak Island, Alaska. Creation of FAI in HF ionospheric modification experiments has been studied by a number of authors who have developed a rich theoretical background. The decay of the irregularities, however, has not been so widely studied yet it has the potential for providing estimates of the parameters of natural irregularity diffusion, which are difficult measure by other means. Hysell, et al. [1996] demonstrated using the decay of radar scatter above the Sura heating facility to estimate irregularity diffusion. A large database of radar backscatter from HAARP generated FAI has been collected over the years. Experiments often cycled the heater power on and off in a way that allowed estimates of the FAI decay rate. The database has been examined to extract decay time estimates and diffusion rates over a range of ionospheric conditions. This presentation will summarize the database and the estimated diffusion rates, and will discuss the potential for targeted experiments for aeronomy measurements. Hysell, D. L., M. C. Kelley, Y. M. Yampolski, V. S. Beley, A. V. Koloskov, P. V. Ponomarenko, and O. F. Tyrnov, HF radar observations of decaying artificial field aligned irregularities, J. Geophys. Res. , 101, 26,981, 1996.

  16. ILC beam energy measurement by means of laser Compton backscattering

    International Nuclear Information System (INIS)

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered γ-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of 10-4 or better on a bunch-to-bunch basis while the electron and positron beams are in collision. (orig.)

  17. Classification of kidney and liver tissue using ultrasound backscatter data

    Science.gov (United States)

    Aalamifar, Fereshteh; Rivaz, Hassan; Cerrolaza, Juan J.; Jago, James; Safdar, Nabile; Boctor, Emad M.; Linguraru, Marius G.

    2015-03-01

    Ultrasound (US) tissue characterization provides valuable information for the initialization of automatic segmentation algorithms, and can further provide complementary information for diagnosis of pathologies. US tissue characterization is challenging due to the presence of various types of image artifacts and dependence on the sonographer's skills. One way of overcoming this challenge is by characterizing images based on the distribution of the backscatter data derived from the interaction between US waves and tissue. The goal of this work is to classify liver versus kidney tissue in 3D volumetric US data using the distribution of backscatter US data recovered from end-user displayed Bmode image available in clinical systems. To this end, we first propose the computation of a large set of features based on the homodyned-K distribution of the speckle as well as the correlation coefficients between small patches in 3D images. We then utilize the random forests framework to select the most important features for classification. Experiments on in-vivo 3D US data from nine pediatric patients with hydronephrosis showed an average accuracy of 94% for the classification of liver and kidney tissues showing a good potential of this work to assist in the classification and segmentation of abdominal soft tissue.

  18. Investigation of sheared liquids by neutron backscattering and reflectivity

    CERN Document Server

    Wolff, M; Hock, R; Frick, B; Zabel, H

    2002-01-01

    We have investigated by neutron scattering structural and dynamical properties of water solutions of the triblock copolymer P85 under shear. To this end a shear cell that suits the requirements for neutron backscattering and another for reflectivity experiments have been built. In reflectivity measurements we find the polymer concentration (nominal concentration of 33% by weight) to vary right at the surface between 12% and 52% for hydrophilic or hydrophobic coated silicon wavers, for temperatures between 18 C and 73 C and for shear rates up to 2500 s sup - sup 1. Additional structural changes deeper in the bulk are also observed. On the backscattering instrument (IN10 at ILL) we find that the liquid appears to stick to the plates of the shear cell, implying an unusual macroscopic velocity distribution that differs from that found earlier for lubrication oils. We report further on changes of the quasielastic line width in the direction of the shear gradient for different temperatures and shear rates. (orig.)

  19. Backscatter Matrix Observations by The GV-HSRL

    Science.gov (United States)

    Hayman, Matthew; Spuler, Scott; Morley, Bruce

    2016-06-01

    The GV-HSRL is a high spectral resolution lidar capable of measuring calibrated backscatter, extinction and circular depolarization from the ground or NSF Gulfstream V platform. In the spring of 2012, the instrument was modified to measure the full backscatter matrix of atmospheric scatterers. This modification enabled us to investigate the polarization properties of oriented particles and further understand where particles orient and how they may impact depolarization lidar data. Observations were performed from the ground at different times with the lidar's tilt angle at 4°, 22° and 32° degrees off zenith. This instrument found oriented ice crystals only produced observable polarization effects at the 32° lidar tilt angle. By contrast, a significant fraction of rain observations have oriented scattering matrices at all three lidar tilt angles. Thus conventional depolarization lidar is generally well suited for characterizing ice crystals but not liquid precipitation. Oriented ice crystals are most commonly investigated by looking for specular scatter from horizontally oriented plates. While this method offers excellent sensitivity to small populations of oriented plats, it has very little capability to determine the fraction of oriented plates if the population is larger than about 1%. We show here that observing f12 scattering matrix element at 32° off zenith may be more effective for estimating the oriented fraction of particles in a volume.

  20. Trace contamination measurements using heavy ion backscattering spectrometry

    International Nuclear Information System (INIS)

    Heavy Ion Backscattering Spectrometry (HIBS) is a tool for measuring surface contamination at levels much lower than previously achievable with ion beam analyses. Many areas of materials research and development require very low levels of impurities, with advanced microelectronics as the best example. HIBS uses low-energy, heavy ions for analysis, taking advantage of the increased backscattering yield which can be obtained from high Z ion beams at low energy. Background due to increased yield from the substrate is eliminated by a thin carbon foil as part of the detector, with a thickness chosen to range out ions scattered from the substrate and allow only ions scattered from impurities heavier than the substrate to reach the detector. The authors research system, using 150-200 keV N+ beams and a single time-of-flight detector optimized for large solid angle, has achieved a sensitivity ranging from ∼5xl010 atoms/cm2 for Fe to ∼1x109 atoms/cm2 for Au on Si, without preconcentration. A stand-alone HIBS prototype which the authors have developed for SEMATECH is expected to reach detection limits of ∼5x109 atoms/cm2 for Fe and ∼1x108 atoms/cm2 for Au on Si. In this paper they discuss in detail the factors which affect sensitivity for HIBS

  1. Study of sporadic-E clouds by backscatter radar

    Directory of Open Access Journals (Sweden)

    Z. Houminer

    Full Text Available It is shown that swept-frequency backscatter ionograms covering a range of azimuths can be used to study the dynamics of sporadic-E clouds. A simple technique based on analytic ray tracing can be used to simulate the observed narrow traces associated with Es patches. This enables the location and extent of the sporadic-E clouds to be determined. The motion of clouds can then be determined from a time sequence of records. In order to demonstrate the method, results are presented from an initial study of 5 days of backscatter ionograms from the Jindalee Stage B data base obtained during March-April 1990. Usually 2–3 clouds were observed each day, mainly during the evening and up to midnight. The clouds lasted from 1–4 h and extended between 30°–80° in azimuth and 150-800 km in range. The clouds were mostly stationary or drifted generally westward with velocities of up to 80 m s–1. Only one cloud was observed moving eastward.

  2. ILC beam energy measurement by means of laser Compton backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Muchnoi, N. [Budker Inst. for Nuclear Physics, Novosibirsk (Russian Federation); Schreiber, H.J.; Viti, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2008-10-15

    A novel, non-invasive method of measuring the beam energy at the International Linear Collider is proposed. Laser light collides head-on with beam particles and either the energy of the Compton scattered electrons near the kinematic end-point is measured or the positions of the Compton backscattered {gamma}-rays, the edge electrons and the unscattered beam particles are recorded. A compact layout for the Compton spectrometer is suggested. It consists of a bending magnet and position sensitive detectors operating in a large radiation environment. Several options for high spatial resolution detectors are discussed. Simulation studies support the use of an infrared or green laser and quartz fiber detectors to monitor the backscattered photons and edge electrons. Employing a cavity monitor, the beam particle position downstream of the magnet can be recorded with submicrometer precision. Such a scheme provides a feasible and promising method to access the incident beam energy with precisions of 10{sup -4} or better on a bunch-to-bunch basis while the electron and positron beams are in collision. (orig.)

  3. Variation of backscatter as an indicator of boundary layer structure

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, M. [UMIST, Dept. of Chemical Engineering, Manchester (United Kingdom); Hunter, G.C. [National Power, Swindon (United Kingdom)

    1997-10-01

    In this work we have developed software to display cross-sections of the variance of backscatter over a given sampling period in addition to its absolute mean. We have analyzed a series of Lidar cross-sections of elevated plumes dispersing into a convective BL and have then derived profiles both of the mean backscatter, , as a function of height and of its relative, shot-to-shot, variation, {radical} /. The latter is a measure of the homogeneity of the aerosol. There is no cheap device for measuring BL depths so we were interested in comparing depths estimated using our Lidar with those predicted by the current ADMS atmospheric dispersion model. This is based on integrating an energy budget to predict the BL development and as such relies on values for the initial lapse rate and for the surface sensible heat flux. A major shortcoming of the model appears to be that, in the absence of measurements, it must assume a default value for the former; the latter may be estimated from surface measurements but is very sensitive to the assumed availability of surface moisture. (LN)

  4. Observations of 2D Doppler backscattering on MAST

    CERN Document Server

    Thomas, D A; Freethy, S J; Huang, B K; Shevchenko, V F; Vann, R G L

    2015-01-01

    The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D Doppler backscattering (DBS) experiments on MAST. SAMI actively probes the plasma edge using a wide (+-40 degrees vertical and horizontal) and tuneable (10-35.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6-24 degrees FWHM at 10-34.5 GHz. This capability is unique to SAMI and is an entirely novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial measurements of phenomena observed on conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of H-mode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch an...

  5. Instrumentation, methods of flood-data collection and transmission, and evaluation of streamflow-gaging network in Indiana

    Science.gov (United States)

    Glatfelter, D.R.; Butch, G.K.

    1994-01-01

    Floods are the number one natural disaster in the Nation, based on loss of life and property. In Indiana, several major floods have occurred during this century. Flooding can occur at any time in any geographic area in Indiana. The degree of flooding can vary from a minor inconvenience to major flooding that results in loss of life and extensive damage. In this study, the existing streamflow-gaging networks in Indiana are evaluated on the basis of meeting flood-data needs of various governmental agencies.

  6. Analysis of GAGE, NY-ESO-1 and SP17 cancer/testis antigen expression in early stage non-small cell lung carcinoma

    International Nuclear Information System (INIS)

    The unique expression pattern and immunogenic properties of cancer/testis antigens make them ideal targets for immunotherapy of cancer. The MAGE-A3 cancer/testis antigen is frequently expressed in non-small cell lung cancer (NSCLC) and vaccination with MAGE-A3 in patients with MAGE-A3-positive NSCLC has shown promising results. However, little is known about the expression of other cancer/testis antigens in NSCLC. In the present study the expression of cancer/testis antigens GAGE, NY-ESO-1 and SP17 was investigated in patients with completely resected, early stage, primary NSCLC. Tumor biopsies from normal lung tissue and from a large cohort (n = 169) of NSCLC patients were examined for GAGE, NY-ESO-1 and SP17 protein expression by immunohistochemical analysis. The expression of these antigens was further matched to clinical and pathological features using univariate cox regression analysis. GAGE and NY-ESO-1 cancer/testis antigens were not expressed in normal lung tissue, while SP17 was expressed in ciliated lung epithelia. The frequency of GAGE, NY-ESO-1 and SP17 expression in NSCLC tumors were 26.0% (44/169), 11.8% (20/169) and 4.7% (8/169), respectively, and 33.1% (56/169) of the tumors expressed at least one of these antigens. In general, the expression of GAGE, NY-ESO-1 and SP17 was not significantly associated with a specific histotype (adenocarcinoma vs. squamous cell carcinoma), but high-level GAGE expression (>50%) was more frequent in squamous cell carcinoma (p = 0.02). Furthermore, the frequency of GAGE expression was demonstrated to be significantly higher in stage II-IIIa than stage I NSCLC (17.0% vs. 35.8%; p = 0.02). Analysis of the relation between tumor expression of GAGE and NY-ESO-1 and survival endpoints revealed no significant associations. Our study demonstrates that GAGE, NY-ESO-1 and SP17 cancer/testis antigens are candidate targets for immunotherapy of NSCLC and further suggest that multi-antigen vaccines may be beneficial

  7. Double beta decay experiments

    International Nuclear Information System (INIS)

    The great sensitivity of double beta decay to neutrino mass and right handed currents has motivated many new and exciting attempts to observe this elusive nuclear phenomenon directly. Experiments in operation and other coming on line in the next one or two years are expected to result in order-of-magnitude improvements in detectable half lives for both the two-neutrino and no-neutrino modes. A brief history of double beta decay experiments is presented together with a discussion of current experimental efforts, including a gas filled time projection chamber being used to study selenium-82. (author)

  8. Plasma beta HCG determination

    International Nuclear Information System (INIS)

    There are three important indications for the early diagnosis of pregnancy through the determination of the beta sub-unit of chorionic gonadotrophin using radioimmunoassay: 1) some patient's or doctor's anxiety to discover the problem; 2) when it will be necessary to employ diagnostic or treatment procedures susceptible to affect the ovum; and 3) in the differential diagnosis of amenorrhoea, uterine hemorrhage and abdominal tumors. Other user's are the diagnosis of missed absortion, and the diagnosis and follow-up of chrorioncarcinoma. The AA. studied 200 determinations of plasma beta-HCG, considering the main difficulties occuring in the clinical use of this relevant laboratory tool in actual Obstetrics. (author)

  9. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.;

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions of...... differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears that the...

  10. Substrate-mediated zero backscattering from dielectric metasurfaces

    CERN Document Server

    Petrov, Mihail; Baryshnikova, Kseniia; Belov, Pavel

    2015-01-01

    In this work, we study optical properties of all-dielectric metasurfaces on top of the high-index substrate. We show that matching the magnitudes and setting the {\\pi}-phase difference of the electric and magnetic dipole moments in nanoparticles, one can obtain a suppression of reflection from the substrate coated with metasurface. In contrast to homogeneous environment, where zero backscattering, or Kerker effect, is observed when electric and magnetic moments are in-phase, the blooming of the substrate occurs when the out-of-phase condition is satisfied, i.e. for the wavelength between the resonances of electric and magnetic dipole moments. We perform numerical simulations of spherical and disk nanoparticle arrays for different permittivities of the substrate, and confirm our model by numerically separating the contributions into the total reflection from nanoparticle arrays and bare substrate. The influence of high-index substrate is crucial for designing optical metasurfaces and photovoltaic elements with...

  11. Spectral characteristics of Compton backscattering sources. Linear and nonlinear modes

    International Nuclear Information System (INIS)

    Compton backscattering (CBS) of laser photons by relativistic electrons is widely used to design X-ray and gamma sources with a bandwidth better than 1% using a tight collimation. In order to obtain a reasonable intensity of the resulting beam one has to increase power of a laser pulse simultaneously with narrowing of the waist in the interaction point. It can lead to nonlinearity of CBS process which is affected on spectral characteristics of the collimated gamma beam (so-called “red-shift” of the spectral line, emission of “soft” photons with energy much less than the spectral line energy). In this paper we have analyzed such an influence using Monte-Carlo technique and have shown that even weak nonlinearity should be taken into account if the gamma beam is formed by a narrow aperture

  12. Back-scatter based whispering gallery mode sensing

    CERN Document Server

    Knittel, Joachim; McAuslan, David L; Brawley, George A; Bowen, Warwick P

    2013-01-01

    Whispering gallery mode biosensors allow selective unlabelled detection of single proteins and, combined with quantum limited sensitivity, the possibility for noninvasive realtime observation of motor molecule motion. However, to date technical noise sources, most particularly low frequency laser noise, have constrained such applications. Here we introduce a new technique for whispering gallery mode sensing based on direct detection of back-scattered light. This experimentally straightforward technique is immune to frequency noise in principle, and further, acts to suppress thermorefractive noise. We demonstrate 27 dB of frequency noise suppression, eliminating frequency noise as a source of sensitivity degradation and allowing an absolute frequency shift sensitivity of 76 kHz. Our results open a new pathway towards single molecule biophysics experiments and ultrasensitive biosensors.

  13. Backscatter absorption gas imaging systems and light sources therefore

    Science.gov (United States)

    Kulp, Thomas Jan; Kliner, Dahv A. V.; Sommers, Ricky; Goers, Uta-Barbara; Armstrong, Karla M.

    2006-12-19

    The location of gases that are not visible to the unaided human eye can be determined using tuned light sources that spectroscopically probe the gases and cameras that can provide images corresponding to the absorption of the gases. The present invention is a light source for a backscatter absorption gas imaging (BAGI) system, and a light source incorporating the light source, that can be used to remotely detect and produce images of "invisible" gases. The inventive light source has a light producing element, an optical amplifier, and an optical parametric oscillator to generate wavelength tunable light in the IR. By using a multi-mode light source and an amplifier that operates using 915 nm pump sources, the power consumption of the light source is reduced to a level that can be operated by batteries for long periods of time. In addition, the light source is tunable over the absorption bands of many hydrocarbons, making it useful for detecting hazardous gases.

  14. Automated determination of crystal orientations from electron backscattering patterns

    DEFF Research Database (Denmark)

    Lassen, Niels Christian Krieger

    1994-01-01

    pattern recognition procedure which enables 8 to 12 bands to be localized in typical EBSPs from a modern system. It will be described, how these automatically localized bands can be indexed and used for optimal estimation of the unknown crystal orientations. A necessary prerequisite for precise......The electron backscattering pattern (EBSP) technique is widely accepted as being an extremely powerful tool for measuring the crystallographic orientation of individual crystallites in polycrystalline materials. Procedures which allow crystal orientations to be calculated on the bases of the...... determination of crystallographic orientations from EBSPs is accurate knowledge of three calibration parameters which describe the position of the point from which the patterns are emitted relative to the phosphor screen on which they are recorded. This thesis will describe a novel method by which these...

  15. Electron backscatter diffraction: Strategies for reliable data acquisition and processing

    International Nuclear Information System (INIS)

    In electron backscatter diffraction (EBSD) software packages there are many user choices both in data acquisition and in data processing and display. In order to extract maximum scientific value from an inquiry, it is helpful to have some guidelines for best practice in conducting an EBSD investigation. The purpose of this article therefore is to address selected topics of EBSD practice, in a tutorial manner. The topics covered are a brief summary on the principles of EBSD, specimen preparation, calibration of an EBSD system, experiment design, speed of data acquisition, data clean-up, microstructure characterisation (including grain size) and grain boundary characterisation. This list is not meant to cover exhaustively all areas where EBSD is used, but rather to provide a resource consisting of some useful strategies for novice EBSD users.

  16. Spectral characteristics of Compton backscattering sources. Linear and nonlinear modes

    Science.gov (United States)

    Potylitsyn, A. P.; Kolchuzhkin, A. M.

    2015-07-01

    Compton backscattering (CBS) of laser photons by relativistic electrons is widely used to design X-ray and gamma sources with a bandwidth better than 1% using a tight collimation. In order to obtain a reasonable intensity of the resulting beam one has to increase power of a laser pulse simultaneously with narrowing of the waist in the interaction point. It can lead to nonlinearity of CBS process which is affected on spectral characteristics of the collimated gamma beam (so-called "red-shift" of the spectral line, emission of "soft" photons with energy much less than the spectral line energy). In this paper we have analyzed such an influence using Monte-Carlo technique and have shown that even weak nonlinearity should be taken into account if the gamma beam is formed by a narrow aperture.

  17. Results from the Daresbury Compton backscattering X-ray source

    Science.gov (United States)

    Laundy, D.; Priebe, G.; Jamison, S. P.; Graham, D. M.; Phillips, P. J.; Smith, S. L.; Saveliev, Y.; Vassilev, S.; Seddon, E. A.

    2012-10-01

    The Daresbury Compton Backscattering X-ray Source uses a high power Ti Sapphire laser interacting in head on geometry with electron bunches in the ALICE energy recovery linear accelerator. X-ray photons with peak energy of 21 keV were generated with the accelerator operating at an energy of 29.6 MeV. The spatial profile of the X-rays emitted near the electron beam axis was measured. The characteristics of the X-ray yield measured as a function of relative timing between the laser pulse and the interacting electron bunch was found to be consistent with the modelled intensity behaviour using measured electron and laser beam parameters.

  18. Compton Backscattering for the Calibration of KEDR Tagging System

    CERN Document Server

    Kaminskiy, V V; Zhilich, V N

    2014-01-01

    KEDR detector has the tagging system (TS) to study the gamma-gamma processes. To determine the two-photon invariant mass, the energies of the scattered at small angles electrons and positrons are measured by the magnetic spectrometer embedded into the lattice of the VEPP--4M collider. The energy resolution (scattered electron/positron energy resolution divided by the beam energy) of this spectrometer varies from 0.6% to 0.03% depending on the electron/positron energy. The Compton backscattering of laser radiation on the electron/positron beam is used for the accurate energy scale and resolution calibration of the tagging system. The report covers the design, recent results and current status of the KEDR TS calibration system.

  19. Compton backscattering for the calibration of KEDR tagging system

    Science.gov (United States)

    Kaminskiy, V. V.; Muchnoi, N. Yu; Zhilich, V. N.

    2014-08-01

    KEDR detector has the tagging system (TS) to study the gamma-gamma processes. To determine the two-photon invariant mass, the energies of the scattered at small angles electrons and positrons are measured by the magnetic spectrometer embedded into the lattice of the VEPP-4M collider. The energy resolution (scattered electron/positron energy resolution divided by the beam energy) of this spectrometer varies from 0.6% to 0.03% depending on the electron/positron energy. The Compton backscattering of laser radiation on the electron/positron beam is used for the accurate energy scale and resolution calibration of the tagging system. The report covers the design, recent results and current status of the KEDR TS calibration system.

  20. Monte Carlo simulations of landmine detection using neutron backscattering imaging

    Energy Technology Data Exchange (ETDEWEB)

    Datema, Cor P. E-mail: c.datema@iri.tudelft.nl; Bom, Victor R.; Eijk, Carel W.E. van

    2003-11-01

    Neutron backscattering is a technique that has successfully been applied to the detection of non-metallic landmines. Most of the effort in this field has concentrated on single detectors that are scanned across the soil. Here, two new approaches are presented in which a two-dimensional image of the hydrogen distribution in the soil is made. The first method uses an array of position-sensitive {sup 3}He-tubes that is placed in close proximity of the soil. The second method is based on coded aperture imaging. Here, thermal neutrons from the soil are projected onto a detector which is typically placed one to several meters above the soil. Both methods use a pulsed D/D neutron source. The Monte Carlo simulation package GEANT 4 was used to investigate the performance of both imaging systems.

  1. Results from the Daresbury Compton backscattering X-ray source

    International Nuclear Information System (INIS)

    The Daresbury Compton Backscattering X-ray Source uses a high power Ti Sapphire laser interacting in head on geometry with electron bunches in the ALICE energy recovery linear accelerator. X-ray photons with peak energy of 21 keV were generated with the accelerator operating at an energy of 29.6 MeV. The spatial profile of the X-rays emitted near the electron beam axis was measured. The characteristics of the X-ray yield measured as a function of relative timing between the laser pulse and the interacting electron bunch was found to be consistent with the modelled intensity behaviour using measured electron and laser beam parameters.

  2. Remote identification of a shipwreck site from MBES backscatter.

    Science.gov (United States)

    Masetti, Giuseppe; Calder, Brian

    2012-11-30

    The method described attempts to remotely identify the shape of an anthropogenic object, such as a wreck of a modern vessel, using reflectivity data from Multi-Beam Echosounder (MBES) systems. In the beam domain, the backscatter strength values - geometrically and radiometrically corrected - are used to extract a large number of Gray Level Co-occurrence Matrix (GLCM) features with different input parameters. Principal Component Analysis (PCA) is applied in order to achieve dimensionality reduction whilst a K-means algorithm clusters as "shipwreck site" a large number of beams for each line. After the geo-referencing process, a K-nearest-neighbors (K-NN) technique is applied as a filter for possible misclassifications. Finally, the shape of the shipwreck site is defined from the georeferenced beams using the α-shape method, constructing an output compatible with Geographic Information Systems (GIS). PMID:22820745

  3. Determination of RF source power in WPSN using modulated backscattering

    CERN Document Server

    Sreedhar, K

    2012-01-01

    A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations. During RF transmission energy consumed by critically energy-constrained sensor nodes in a WSN is related to the life time system, but the life time of the system is inversely proportional to the energy consumed by sensor nodes. In that regard, modulated backscattering (MB) is a promising design choice, in which sensor nodes send their data just by switching their antenna impedance and reflecting the incident signal coming from an RF source. Hence wireless passive sensor networks (WPSN) designed to operate using MB do not have the lifetime constraints. In this we are going to investigate the system analytically. To obtain interference-free communication connectivity with the WPSN nodes number of RF sources is determined and analyzed i...

  4. Many-beam dynamical simulation of electron backscatter diffraction patterns.

    Science.gov (United States)

    Winkelmann, Aimo; Trager-Cowan, Carol; Sweeney, Francis; Day, Austin P; Parbrook, Peter

    2007-01-01

    We present an approach for the simulation of complete electron backscatter diffraction (EBSD) patterns where the relative intensity distributions in the patterns are accurately reproduced. The Bloch wave theory is applied to describe the electron diffraction process. For the simulation of experimental patterns with a large field of view, a large number of reflecting planes has to be taken into account. This is made possible by the Bethe perturbation of weak reflections. Very good agreement is obtained for simulated and experimental patterns of gallium nitride GaN{0001} at 20kV electron energy. Experimental features like zone-axis fine structure and higher-order Laue zone rings are accurately reproduced. We discuss the influence of the diffraction of the incident beam in our experiment. PMID:17126489

  5. Nondestructive testing of concrete by gamma backscattering method

    International Nuclear Information System (INIS)

    Nondestructive testing (NDT) methods are used to examine objects without destroying it. In many situations like working industrial plants and fluid transportation system, inspection of huge or thick sized objects by destructive methods are not desirable. The Compton backscattering of gamma rays, one of NDT techniques could be used for material characterization and detection of defects in materials easily. Concrete structures require testing after the concrete has hardened, to determine whether the structure is suitable for its designed use. There is a possibility of defects in the constructed buildings and structures, and therefore, defects like voids and cracks, if any, have to be evaluated for the purpose. Further, periodic testing of old buildings and structures to know their integrity has become a necessity. These types of testings can be conducted only by employing nondestructive techniques

  6. Diffuse Backscattering Mueller Matrices Patterns from Turbid Media

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lian-Shun; ZHU Chen; WANG Zhi-Ping; ZHANG Jing

    2006-01-01

    We present experimental measurements and theory of the diffusely backscattered Mueller matrix patterns that arise from illuminating a turbid medium with a polarized laser beam. Our technique employs polarized light from a He-Ne laser (λ= 632.8 nm) focused onto the surface of the scattering medium. A surface area of approximately 2×2 cm2 centred on the light input point is imaged through polarization analysis optics onto a CCD camera. The Mueller matrix is reconstructed by 49 intensity measurements with various orientations of polarizer and analyser. The measured Mueller matrix of polystyrene spheres is compared with the theory result of incoherent scattering of light by spheres. It shows that the azimuthal patterns of the Mueller matrix are determined by the symmetry of the turbid media and the shape of scattering particles. The result is further proved by experiments with polystyrene spheres of different concentrations in de-ionized water.

  7. Compton backscattering of intracavity storage ring free-electron laser radiation

    International Nuclear Information System (INIS)

    We discuss the γ- ray production by Compton backscattering of intracavity S.R. FEL radiation. We use a semi-analytical model which provides the build up of the signal combined with the storage ring damping mechanism and derive simple relations yielding the connection between backscattered photons brightness and the intercavity laser equilibrium intensity

  8. Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

    International Nuclear Information System (INIS)

    Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

  9. Stratospheric backscatter, extinction, and lidar ratio profiling after the Mt. Pinatubo eruptions

    International Nuclear Information System (INIS)

    Since August 1991 the stratospheric aerosol layer is continuously monitored with a combination Raman elastic-backscatter lidar, groundbased systems. XeCl excimer laser is used as the radiation source. Signals elastically backscattered from air molecules and particles and inelastically Raman backscattered from nitrogen molecules are detected. The measurements of these two signal profiles up to 35 km height allows the separate and independent determination of aerosol extinction and backscatter properties in the perturbed lower stratosphere. The extinction coefficient is derived from the nitrogen Raman signal profile, while the backscatter coefficient is obtained from the elastic-to-inelastic backscatter signal ratio. In this way, also the extinction-to-backscatter, or lidar, ratio profile is determined. For the first time, lidar ratios are determined in the perturbed stratospheric layer by the use of remote sensing only. The lidar ratio contains information about the size range of the stratospheric particles which are assumed to be sulfuric acid droplets, and it is needed in the calculation of aerosol optical properties from data taken with a typical backscatter lidar

  10. Identification of major backscattering sources in trees and shrubs at 10 GHz

    Science.gov (United States)

    Zoughi, R.; Wu, L. K.; Moore, R. K.

    1986-01-01

    A short-range very-fine-resolution FM-CW radar scatterometer has been used to identify the primary contributors to 10-GHz radar backscatter from pine, pin oak, American sycamore and sugar maple trees, and from creeping juniper shrubs. This system provided a range resolution of 11 cm and gave a 16-cm diameter illumination area at the target range of about 4 m. For a pine tree, the needles caused the strongest backscatter as well as the strongest attenuation in the radar signal. Cones, although insignificant contributors to the total backscatter, were more important for backscattering than for attenuation. For the rest of the trees, leaves were the strongest cause of backscattering and attenuation. However, in the absence of leaves, the petioles, small twigs, and branches gave relatively strong backscatter. For American sycamore and sugar maple trees, the fruits did not affect the total backscatter unless they were packed in clusters. For creeping juniper the backscattered energy and attenuation in the radar signal were mainly due to the top two layers of the evergreen scales. The contribution of the tree trunks was not determined.

  11. The Low Backscattering Targets Classification in Urban Areas

    Science.gov (United States)

    Shi, L.

    2012-07-01

    The Polarimetric and Interferometric Synthetic Aperture Radar (POLINSAR) is widely used in urban area nowadays. Because of the physical and geometric sensitivity, the POLINSAR is suitable for the city classification, power-lines detection, building extraction, etc. As the new X-band POLINSAR radar, the china prototype airborne system, XSAR works with high spatial resolution in azimuth (0.1 m) and slant range (0.4 m). In land applications, SAR image classification is a useful tool to distinguish the interesting area and obtain the target information. The bare soil, the cement road, the water and the building shadow are common scenes in the urban area. As it always exists low backscattering sign objects (LBO) with the similar scattering mechanism (all odd bounce except for shadow) in the XSAR images, classes are usually confused in Wishart-H-Alpha and Freeman-Durden methods. It is very hard to distinguish those targets only using the general information. To overcome the shortage, this paper explores an improved algorithm for LBO refined classification based on the Pre-Classification in urban areas. Firstly, the Pre-Classification is applied in the polarimetric datum and the mixture class is marked which contains LBO. Then, the polarimetric covariance matrix C3 is re-estimated on the Pre-Classification results to get more reliable results. Finally, the occurrence space which combining the entropy and the phase-diff standard deviation between HH and VV channel is used to refine the Pre-Classification results. The XSAR airborne experiments show the improved method is potential to distinguish the mixture classes in the low backscattering objects.

  12. THE LOW BACKSCATTERING TARGETS CLASSIFICATION IN URBAN AREAS

    Directory of Open Access Journals (Sweden)

    L. Shi

    2012-07-01

    Full Text Available The Polarimetric and Interferometric Synthetic Aperture Radar (POLINSAR is widely used in urban area nowadays. Because of the physical and geometric sensitivity, the POLINSAR is suitable for the city classification, power-lines detection, building extraction, etc. As the new X-band POLINSAR radar, the china prototype airborne system, XSAR works with high spatial resolution in azimuth (0.1 m and slant range (0.4 m. In land applications, SAR image classification is a useful tool to distinguish the interesting area and obtain the target information. The bare soil, the cement road, the water and the building shadow are common scenes in the urban area. As it always exists low backscattering sign objects (LBO with the similar scattering mechanism (all odd bounce except for shadow in the XSAR images, classes are usually confused in Wishart-H-Alpha and Freeman-Durden methods. It is very hard to distinguish those targets only using the general information. To overcome the shortage, this paper explores an improved algorithm for LBO refined classification based on the Pre-Classification in urban areas. Firstly, the Pre-Classification is applied in the polarimetric datum and the mixture class is marked which contains LBO. Then, the polarimetric covariance matrix C3 is re-estimated on the Pre-Classification results to get more reliable results. Finally, the occurrence space which combining the entropy and the phase-diff standard deviation between HH and VV channel is used to refine the Pre-Classification results. The XSAR airborne experiments show the improved method is potential to distinguish the mixture classes in the low backscattering objects.

  13. Feasibility of using backscattered muons for archeological imaging

    Science.gov (United States)

    Bonal, N.; Preston, L. A.

    2013-12-01

    Use of nondestructive methods to accurately locate and characterize underground objects such as rooms and tools found at archeological sites is ideal to preserve these historic sites. High-energy cosmic ray muons are very sensitive to density variation and have been used to image volcanoes and archeological sites such as the Egyptian and Mayan pyramids. Muons are subatomic particles produced in the upper atmosphere that penetrate the earth's crust up to few kilometers. Their absorption rate depends on the density of the materials through which they pass. Measurements of muon flux rate at differing directions provide density variations of the materials between the muon source (cosmic rays and neutrino interactions) and the detector, much like a CAT scan. Currently, muon tomography can resolve features to the sub-meter scale making it useful for this type of work. However, the muon detector must be placed below the target of interest. For imaging volcanoes, the upper portion is imaged when the detector is placed on the earth's surface at the volcano's base. For sites of interest beneath the ground surface, the muon detector would need to be placed below the site in a tunnel or borehole. Placing the detector underground can be costly and may disturb the historical site. We will assess the feasibility of imaging the subsurface using upward traveling muons, to eliminate the current constraint of positioning the detector below the target. This work consists of three parts 1) determine the backscattered flux rate from theory, 2) distinguish backscattered from forward scattered muons at the detector, and 3) validate the theoretical results with field experimentation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  14. Statistics of vertical backscatter profile of cirrus clouds

    Directory of Open Access Journals (Sweden)

    P. Veglio

    2011-09-01

    Full Text Available A nearly global statistical analysis of vertical backscatter and extinction profiles of cirrus clouds collected by the CALIOP lidar, on-board of the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, is presented.

    Statistics on frequency of occurrence and distributions of bulk properties of cirrus clouds in general and, for the first time, of horizontally homogeneous (on a 5-km field of view cirrus clouds only are provided. Annual and seasonal backscatter profiles (BSP are computed for the horizontally homogeneous cirri. Differences found in the day/night cases and for midlatitudes and tropics are studied in terms of the mean physical parameters of the clouds from which they are derived.

    The relation between cloud physical parameters (optical depth, geometrical thickness and temperature and the shape of the BSP is investigated. It is found that cloud geometrical thickness is the main parameter affecting the shape of the mean CALIOP BSP. Specifically, cirrus clouds with small geometrical thicknesses show a maximum in mean BSP curve placed near cloud top. As the cloud geometrical thickness increases the BSP maximum shifts towards cloud base. Cloud optical depth and temperature have smaller effect on the shape of the CALIOP BSPs. In general a slight increase in the BSP maximum is observed as cloud temperature and optical depth increase.

    In order to fit mean BSPs, as functions of geometrical thickness and position within the cloud layer, polynomial functions are provided. The impact on satellite radiative transfer simulations in the infrared spectrum when using either a constant ice-content (IWC along the cloud vertical dimension or an IWC profile derived from the BSP fitting functions is evaluated. It is, in fact, demonstrated that, under realistic hypotheses, the mean BSP is linearly proportional to the IWC profile.

  15. HF radar observations of ionospheric backscatter during geomagnetically quiet periods

    Science.gov (United States)

    Kane, T. A.; Makarevich, R. A.; Devlin, J. C.

    2012-01-01

    The quiet-time coherent backscatter from the F-region observed by the Tasman International Geospace Environment Radar (TIGER) Bruny Island HF radar is analysed statistically in order to determine typical trends and controlling factors in the ionospheric echo occurrence. A comparison of the F-region peak density values from the IRI-2007 model and ionosonde measurements in the vicinity of the radar's footprint shows a very good agreement, particularly at subauroral and auroral latitudes, and model densities within the radar's footprint are used in the following analyses. The occurrence of F-region backscatter is shown to exhibit distinct diurnal, seasonal and solar cycle variations and these are compared with model trends in the F-region peak electron density and Pedersen conductance of the underlying ionosphere. The solar cycle effects in occurrence are demonstrated to be strong and more complex than a simple proportionality on a year-to-year basis. The diurnal and seasonal effects are strongly coupled to each other, with diurnal trends exhibiting a systematic gradual variation from month to month that can be explained when both electron density and conductance trends are considered. During the night, the echo occurrence is suggested to be controlled directly by the density conditions, with a direct proportionality observed between the occurrence and peak electron density. During the day, the echo occurrence appears to be controlled by both conductance and propagation conditions. It is shown that the range of echo occurrence values is smaller for larger conductances and that the electron density determines what value the echo occurrence takes in that range. These results suggest that the irregularity production rates are significantly reduced by the highly conducting E layer during the day while F-region density effects dominate during the night.

  16. HF radar observations of ionospheric backscatter during geomagnetically quiet periods

    Directory of Open Access Journals (Sweden)

    T. A. Kane

    2012-01-01

    Full Text Available The quiet-time coherent backscatter from the F-region observed by the Tasman International Geospace Environment Radar (TIGER Bruny Island HF radar is analysed statistically in order to determine typical trends and controlling factors in the ionospheric echo occurrence. A comparison of the F-region peak density values from the IRI-2007 model and ionosonde measurements in the vicinity of the radar's footprint shows a very good agreement, particularly at subauroral and auroral latitudes, and model densities within the radar's footprint are used in the following analyses. The occurrence of F-region backscatter is shown to exhibit distinct diurnal, seasonal and solar cycle variations and these are compared with model trends in the F-region peak electron density and Pedersen conductance of the underlying ionosphere. The solar cycle effects in occurrence are demonstrated to be strong and more complex than a simple proportionality on a year-to-year basis. The diurnal and seasonal effects are strongly coupled to each other, with diurnal trends exhibiting a systematic gradual variation from month to month that can be explained when both electron density and conductance trends are considered. During the night, the echo occurrence is suggested to be controlled directly by the density conditions, with a direct proportionality observed between the occurrence and peak electron density. During the day, the echo occurrence appears to be controlled by both conductance and propagation conditions. It is shown that the range of echo occurrence values is smaller for larger conductances and that the electron density determines what value the echo occurrence takes in that range. These results suggest that the irregularity production rates are significantly reduced by the highly conducting E layer during the day while F-region density effects dominate during the night.

  17. Evaluation of neutrino masses from $m_{\\beta\\beta}$ values

    CERN Document Server

    Khrushchov, V V

    2008-01-01

    A neutrino mass matrix is considered under conditions of the CP invariance and the negligible reactor mixing $\\theta_{13}$ angle. Absolute mass values for three neutrinos are evaluated in normal and inverted hierarchy spectra on the ground of data for oscillation mixing neutrino parameters and effective neutrino mass entering into a probability of neutrinoless two beta decay $m_{\\beta\\beta}$ values.

  18. Low-beta structures

    OpenAIRE

    M. Vretenar(CERN, Geneva, Switzerland)

    2012-01-01

    'Low-beta' radio-frequency accelerating structures are used in the sections of a linear accelerator where the velocity of the particle beam increases with energy. The requirement for space periodicity to match the increasing particle velocity led to the development of a large variety of structures, both normal and superconducting, which are described in this lecture.

  19. Applied Beta Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements.

  20. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross-section...

  1. Neutrinoless Double Beta Decay

    CERN Document Server

    Päs, Heinrich

    2015-01-01

    We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.

  2. Applied Beta Dosimetry

    International Nuclear Information System (INIS)

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements

  3. Profiling of back-scattered electrons in opposed magnetic field of a Twin Electron Beam Gun

    International Nuclear Information System (INIS)

    Electron gun is extensively used in material processing, physical vapour deposition and atomic vapour based laser processes. In these processes where the electron beam is incident on the substrate, a significant fraction of electron beam gets back-scattered from the target surface. The trajectory of this back scattered electron beam depends on the magnetic field in the vicinity. The fraction of back-scattered depends on the atomic number of the target metal and can be as high as ∼40% of the incident beam current. These back-scattered electrons can cause undesired hot spots and also affect the overall process. Hence, the study of the trajectory of these back-scattered electrons is important. This paper provides the details of experimentally mapped back-scattered electrons of a 2×20kW Twin Electron Beam Gun (TEBG) in opposed magnetic field i.e. with these guns placed at 180° to each other.

  4. Interferon Beta-1b Injection

    Science.gov (United States)

    Interferon beta-1b injection is used to reduce episodes of symptoms in patients with relapsing-remitting (course ... and problems with vision, speech, and bladder control). Interferon beta-1b is in a class of medications ...

  5. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... for Disease Control and Prevention Centre for Genetics Education (Australia) Cold Spring Harbor Laboratory: Your Genes Your Health Disease InfoSearch: Beta Thalassemia Genomics Education Programme (UK) MalaCards: dominant beta-thalassemia Merck Manual ...

  6. Beta gets better with age

    OpenAIRE

    Tomunen, Tuomas

    2015-01-01

    The objective of my thesis is to study the cause for the low beta anomaly, which is an observation that the high beta stocks perform poorly relative to the low beta stocks. Based on earlier findings, I hypothesize that if a stock has high investor attention, its price overreacts to market-wide shocks, which results in a positive measurement error in its beta. Simultaneously, high attention causes overpricing, because the stock overreacts more often to positive shocks than to negat...

  7. The relationship between VHF radar auroral backscatter amplitude and Doppler velocity: a statistical study

    Directory of Open Access Journals (Sweden)

    B. A. Shand

    Full Text Available A statistical investigation of the relationship between VHF radar auroral backscatter intensity and Doppler velocity has been undertaken with data collected from 8 years operation of the Wick site of the Sweden And Britain Radar-auroral Experiment (SABRE. The results indicate three different regimes within the statistical data set; firstly, for Doppler velocities <200 m s–1, the backscatter intensity (measured in decibels remains relatively constant. Secondly, a linear relationship is observed between the backscatter intensity (in decibels and Doppler velocity for velocities between 200 m s–1 and 700 m s–1. At velocities greater than 700 m s–1 the backscatter intensity saturates at a maximum value as the Doppler velocity increases. There are three possible geophysical mechanisms for the saturation in the backscatter intensity at high phase speeds: a saturation in the irregularity turbulence level, a maximisation of the scattering volume, and a modification of the local ambient electron density. There is also a difference in the dependence of the backscatter intensity on Doppler velocity for the flow towards and away from the radar. The results for flow towards the radar exhibit a consistent relationship between backscatter intensity and measured velocities throughout the solar cycle. For flow away from the radar, however, the relationship between backscatter intensity and Doppler velocity varies during the solar cycle. The geometry of the SABRE system ensures that flow towards the radar is predominantly associated with the eastward electrojet, and flow away is associated with the westward electrojet. The difference in the backscatter intensity variation as a function of Doppler velocity is attributed to asymmetries between the eastward and westward electrojets and the geophysical parameters controlling the backscatter amplitude.

  8. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  9. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  10. Beta and muon decays

    International Nuclear Information System (INIS)

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  11. Impact of diurnal variation in vegetation water content on radar backscatter of maize during water stress

    Science.gov (United States)

    van Emmerik, Tim; Steele-Dunne, Susan; Judge, Jasmeet; van de Giesen, Nick

    2014-05-01

    Microwave emission and backscatter of vegetated surfaces are influenced by vegetation water content (VWC), which varies in response to availability of soil moisture in the root zone. Understanding the influence of diurnal VWC dynamics on radar backscatter will improve soil moisture retrievals using microwave remote sensing, and will provide insight into the potential use for radar to directly monitor vegetation water status. The goal of this research is to investigate the effect of diurnal variation in VWC of an agricultural canopy on backscatter for different radar configurations. Water stress was induced in a corn (Zea mays) canopy near Citra, Florida, between September 1 and October 20, 2013. Diurnal destructive samples from the canopy were collected to determine leaf, stalk and total VWC. Water stress was quantified by calculating the evaporation deficit and measuring the soil water tension. The water-cloud model was used to model the influence of VWC and soil moisture variations on backscatter for a range of frequencies, polarizations and incidence angles. Furthermore, radar backscatter time series was simulated to show the effect of water stress on the diurnal variation in backscatter due to VWC. Results of this study show the very significant effects that VWC dynamics have on radar backscatter. We also highlight the potential for vegetation and soil water status monitoring using microwave remote sensing.

  12. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some form...... of language interoperability between Java and BETA is required. The first approach is to use the Java Native Interface and use C to bridge between Java and BETA. This results in a workable, but complicated solution. The second approach is to let the BETA compiler generate Java class files. With this...... approach it is possible to implement plug-ins in BETA and even inherit from Java classes. In the paper the two approaches are described together with part of the mapping from BETA to Java class files. http://www.sciencedirect.com/science/journal/15710661...

  13. COM Support in BETA

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Component technologies based on binary units of independent production are some of the most important contributions to software architecture and reuse during recent years. Especially the COM technologies and the CORBA standard from the Object Management Group have contributed new and interesting ...... principles for software architecture, and proven to be useful in parctice. In this paper ongoing work with component support in the BETA language is described....

  14. Beta decay for pedestrians

    CERN Document Server

    Lipkin, Harry Jeannot

    1962-01-01

    The ""pedestrian approach"" was developed to describe some essentially simple experimental results and their theoretical implications in plain language. In this graduate-level text, Harry J. Lipkin presents simply, but without oversimplification, the aspects of beta decay that can be understood without reference to the formal theory; that is, the reactions that follow directly from conservation laws and elementary quantum mechanics.The pedestrian treatment is neither a substitute for a complete treatment nor a watered-down version.

  15. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  16. On the resistance behaviour of high elongation strain gages. Pt. 1. Physical foundations; Zur Widerstandsaenderung von Dehnungsmessstreifen bei grossen Deformationen. T. 1. Physikalische Grundlagen

    Energy Technology Data Exchange (ETDEWEB)

    Stockmann, M. [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Experimentelle Mechanik; Naumann, J. [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Fakultaet fuer Maschinenbau und Verfahrenstechnik; Bormann, P. [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Experimentelle Mechanik; Pelz, F. [Technische Univ. Chemnitz-Zwickau, Chemnitz (Germany). Experimentelle Mechanik

    1996-04-01

    The technique of strain measurements by electrical strain gages is one of the most essential methods in experimental analysis of mechanical loads. The precise investigation of high elongation strain requests the consideration of nonlinear behaviour, which is not covered by standard equipment. Theory and experimental verifications of the nonlinear effects are presented. (orig.)

  17. Quantification of uncertainties in the 100-year flow at an ungaged site near a gaged station and its application in Georgia

    Science.gov (United States)

    Cho, Huidae; Bones, Emma

    2016-08-01

    The Federal Emergency Management Agency has introduced the concept of the "1-percent plus" flow to incorporate various uncertainties in estimation of the 100-year or 1-percent flow. However, to the best of the authors' knowledge, no clear directions for calculating the 1-percent plus flow have been defined in the literature. Although information about standard errors of estimation and prediction is provided along with the regression equations that are often used to estimate the 1-percent flow at ungaged sites, uncertainty estimation becomes more complicated when there is a nearby gaged station because regression flows and the peak flow estimate from a gage analysis should be weighted to compute the weighted estimate of the 1-percent flow. In this study, an equation for calculating the 1-percent plus flow at an ungaged site near a gaged station is analytically derived. Also, a detailed process is introduced for calculating the 1-percent plus flow for an ungaged site near a gaged station in Georgia as an example and a case study is performed. This study provides engineers and practitioners with a method that helps them better assess flood risks and develop mitigation plans accordingly.

  18. Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

    Science.gov (United States)

    Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

    2014-01-01

    The safety-of-flight parameters for the Adaptive Compliant Trailing Edge (ACTE) flap experiment require that flap-to-wing interface loads be sensed and monitored in real time to ensure that the structural load limits of the wing are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces were monitored; each contained four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty-one applied test load cases were developed using the predicted in-flight loads. Pre-test predictions of strain gage responses were produced using finite element method models of the interface fittings. Predicted and measured test strains are presented. A load testing rig and three hydraulic jacks were used to apply combinations of shear, bending, and axial loads to the interface fittings. Hardware deflections under load were measured using photogrammetry and transducers. Due to deflections in the interface fitting hardware and test rig, finite element model techniques were used to calculate the reaction loads throughout the applied load range, taking into account the elastically-deformed geometry. The primary load equations were selected based on multiple calibration metrics. An independent set of validation cases was used to validate each derived equation. The 2-sigma residual errors for the shear loads were less than eight percent of the full-scale calibration load; the 2-sigma residual errors for the bending moment loads were less than three percent of the full-scale calibration load. The derived load equations for shear, bending, and axial loads are presented, with the calculated errors for both the calibration cases and the independent validation load cases.

  19. Influence of the Testing Gage Length on the Strength, Young's Modulus and Weibull Modulus of Carbon Fibres and Glass Fibres

    Directory of Open Access Journals (Sweden)

    Luiz Claudio Pardini

    2002-10-01

    Full Text Available Carbon fibres and glass fibres are reinforcements for advanced composites and the fiber strength is the most influential factor on the strength of the composites. They are essentially brittle and fail with very little reduction in cross section. Composites made with these fibres are characterized by a high strength/density ratio and their properties are intrisically related to their microstructure, i.e., amount and orientation of the fibres, surface treatment, among other factors. Processing parameters have an important role in the fibre mechanical behaviour (strength and modulus. Cracks, voids and impurities in the case of glass fibres and fibrillar misalignments in the case of carbon fibres are created during processing. Such inhomogeneities give rise to an appreciable scatter in properties. The most used statistical tool that deals with this characteristic variability in properties is the Weibull distribution. The present work investigates the influence of the testing gage length on the strength, Young's modulus and Weibull modulus of carbon fibres and glass fibres. The Young's modulus is calculated by two methods: (i ASTM D 3379M, and (ii interaction between testing equipment/specimen The first method resulted in a Young modulus of 183 GPa for carbon fibre, and 76 GPa for glass fibre. The second method gave a Young modulus of 250 GPa for carbon fibre and 50 GPa for glass fibre. These differences revelead differences on how the interaction specimen/testing machine can interfere in the Young modulus calculations. Weibull modulus can be a tool to evaluate the fibre's homogeneity in terms of properties and it is a good quality control parameter during processing. In the range of specimen gage length tested the Weibull modulus for carbon fibre is ~ 3.30 and for glass fibres is ~ 5.65, which indicates that for the batch of fibres tested, the glass fibre is more uniform in properties.

  20. Conditions for observation of the enhanced backscattering phenomenon in a turbulent atmosphere

    Science.gov (United States)

    Chrzanowski, Janusz; Kirkiewicz, Jozef; Kravtsov, Yuri A.

    2003-11-01

    Influence of enhanced backscattering effect on laser measurements of dust and aerosols content in a turbulent atmosphere is discussed. It is shown that doubling of the backscattered light intensity, characteristic for enhanced backscattering, leads to overestimating dust content in the air. To avoid undesirable effect of overestimation, it is recommended to displace receiving aperture sidewise relatively to laser source. Other method to eliminate overestimation is to use wider laser beam and extended receiving aperture as compared to coherence radius of the scattered wave field.

  1. Backscatter amplification effect for a reflected partially coherent Gaussian beam in turbulent medium

    Science.gov (United States)

    Xiang, Ning-Jing; Wu, Zhen-Sen; Guo, Qiu-Fen; Wang, Ming-Jun

    2015-09-01

    The extended Huygens-Fresnel principle is used to develop a formulation for the backscattered intensity enhancement of a Gaussian Schell-model source beam through a weak turbulence. The results are shown that backscattered intensity enhancement factor of the reflected GSM beam is concerned with the coherence length of source, the wavelength, the size of target and wave structure function. In addition, the closed-form expressions can interpret backscattered intensity enhancement of plane and spherical wave scattered from a diffuse target. The results are illustrated by examples and compared with the previous work.

  2. The Monte Carlo calculation of gamma-ray backscattering from various materials

    International Nuclear Information System (INIS)

    The question is discussed of gamma backscattering on different materials. For coaxial geometry with a point source placed next to the material surface, using the Monte Carlo method the number of backscattered photons in variation with atomic number Z of the scatterer is calculated. A multiple scattering calculation is performed for 60Co and 137Cs. The obtained results are plotted in graphs showing the minima in each period of the periodic system, this for gases. For other elements the number of backscattered photons is dependent on the atomic number Z, primary gamma radiation energy, density, and the geometry of the experiment. (author)

  3. Suppressing Rayleigh backscatter and code noise from all-fiber digital interferometers.

    Science.gov (United States)

    Ngo, Silvie; Shaddock, Daniel A; McRae, Terry G; Lam, Timothy T-Y; Chow, Jong H; Gray, Malcolm B

    2016-01-01

    We configure an all-fiber digital interferometer to eliminate both code noise and Rayleigh backscatter noise from bidirectional measurements. We utilize a sawtooth phase ramp to upconvert code noise beyond our signal bandwidth, demonstrating an in-band noise reduction of approximately two orders of magnitude. In addition, we demonstrate, for the first time to our knowledge, the use of relative code delays within a digital-interferometer system to eliminate Rayleigh-backscatter noise, resulting in a noise reduction of a factor of 50. Finally, we identify double Rayleigh-backscatter noise as our limiting noise source and suggest two methods to minimize this noise source. PMID:26696164

  4. Generation and Investigation of Backscatter Mosaics using TerraSAR-X Data

    OpenAIRE

    Rizzoli, Paola; Bräutigam, Benjamin; Wollstadt, Steffen; Mittermayer, Josef

    2010-01-01

    Global backscatter data is required for accurate performance estimation and instrument commanding inside the TerraSAR-X and TanDEM-X missions. The goal of this work is the generation of an X-Band backscatter map by assembling images acquired by the TSX satellite. The complete data ground coverage will be achievable with TanDEM-X mission data. An interpolator, that allows the estimation of the on ground backscatter for any required polarization and incidence angle from the available data, has ...

  5. Backscattering analysis of thin films on non-flat surfaces

    Science.gov (United States)

    Berning, Paul R.; Niiler, Andrus

    1993-02-01

    In order to allow for the analysis of contaminant layers on powder surfaces, methods of adapting ion beam analysis techniques for use on non-flat surfaces have been developed. In this work, particular attention is given to situations where the dimensions of the surface structures are much larger than the thickness of the film, but much smaller than the ion beam spot size. It is assumed that the surface material is conformal and evenly distributed across the surface. Two methods are discussed; both are designed to analyze backscattered ion energy spectra through the use of available simulation programs. These methods rely on knowledge of the distribution of surface-normal to beam-direction angles present on the surface shape to be studied. Examples of this and other relevant distribution functions corresponding to several types of surface shape will be shown. The methods described here are used to study oxide layers grown thermally on small (≈ 130 μm) spherical titanium powder particles. We also show examples of how to empirically determine the distribution of surface tilt angles present on a surface of unknown shape when the nature of the surface film is known.

  6. Compton Backscattering Concept for the Production of Molybdenum-99

    Energy Technology Data Exchange (ETDEWEB)

    L. Merminga, G.A. Krafft

    2009-05-01

    The medical isotope Molybdenum-99 is presently used for 80-85% of all nuclear medicine procedures and is produced by irradiating highly enriched uranium U-235 targets in NRU reactors. It was recently proposed that an electron linac be used for the production of 99Mo via photo-fission of a natural uranium target coming from the excitation of the giant dipole resonance around 15 MeV. The photons can be produced using the braking radiation (“bremsstrahlung”) spectrum of an electron beam impinged on a high Z material. In this paper we present an alternate concept for the production of 99Mo which is also based on photo-fission of U-238, but where the ~15 MeV gamma-rays are produced by Compton backscattering of laser photons from relativistic electrons. We assume a laser wavelength of 330 nm, resulting in 485 MeV electron beam energy, and 10 mA of average current. Because the induced energy spread on the electron beam is a few percent, one may recover most of the electron beam energy, which substantially increases the efficiency of the system. The accelerator concept, based on a three-pass recirculation system with energy recovery, is described and efficiency estimates are presented.

  7. 63Ni β range and backscattering in confined geometries

    International Nuclear Information System (INIS)

    To know the spatial distribution of ion pairs resulting from 63Ni β radiation in the gas phase is important for the electron capture detector. The 63Ni-induced, initial ion pair distribution was therefore measured in a variety of gases with two techniques: a conventional one based on the electrical saturation current at variable interelectrode distances, and an unconventional one based on luminescence from a plastic scintillator. The data are analyzed in terms of two ranges, d50 and d95, that describe the distances from a planar radioactive foil within which 50% and 95% of the total gas-phase ionization occur. The data from the electrical measurement show unexpected evidence of strong β backscattering and secondary electron emission from the counter-electrode. Under these (non-exponential) conditions, d50 values in the common detector gases nitrogen and argon/methane vary from 0.5 to 1.0 mm, depending on the nature of the counter-electrode. Calculations based on the quasi-exponential range found at longer distances in electrical measurements yield values of about 2.5 mm (which are low because of geometric measurement bias). In contrast, the data from the luminescence measurement are almost completely exponential and d50 values for argon (+5% methane) and nitrogen are 2.8 and 3.8 mm, respectively. The d95 values vary from 12 to 16 mm for the luminescence, to 6 and 9 mm for the (less reliable) electrical measurement; all at ambient conditions

  8. Investigation of radar backscattering from second-year sea ice

    Science.gov (United States)

    Lei, Guang-Tsai; Moore, Richard K.; Gogineni, S. P.

    1988-01-01

    The scattering properties of second-year ice were studied in an experiment at Mould Bay in April 1983. Radar backscattering measurements were made at frequencies of 5.2, 9.6, 13.6, and 16.6 GHz for vertical polarization, horizontal polarization and cross polarizations, with incidence angles ranging from 15 to 70 deg. The results indicate that the second-year ice scattering characteristics were different from first-year ice and also different from multiyear ice. The fading properties of radar signals were studied and compared with experimental data. The influence of snow cover on sea ice can be evaluated by accounting for the increase in the number of independent samples from snow volume with respect to that for bare ice surface. A technique for calculating the snow depth was established by this principle and a reasonable agreement has been observed. It appears that this is a usable way to measure depth in snow or other snow-like media using radar.

  9. Measurement of crystal misorientation distribution by electron backscatter diffraction

    International Nuclear Information System (INIS)

    It is well known stress corrosion cracking in stainless steel and nickel based alloy is enhanced by plastic strain induced in the material, although the reason why has not been fully understood. Since stress corrosion cracking begins from small crack initiation and its growth, it is important to know the inhomogeneous distribution of plastic strain. Electron backscatter diffraction (EBSD) enables us to measure crystal orientations on specimen surface with a spatial resolution of nano-meter order. The magnitude of local plastic strain can be estimated from change in crystal orientation (misorientation) obtained. In this study, distributions of the misorientation were evaluated by using EBSD. A tensile specimen made of pure copper was subjected to tensile test to introduce plastic strain. From changes in surface images of the specimen during the test, distribution of plastic strain was identified by using the image correlation technique and was compared with distribution of misorientation obtained by EBSD measurement. It was revealed that the misorientation correlates well with dislocation density introduced by deformation rather than with local plastic strain. A data processing technique for improving accuracy of measured data of crystal orientation was developed and was successfully applied to obtain distributions of misorientation. The improved misorientation map showed that the misorientation tended to concentrate at grain boundaries. Influence of setting parameters in the new processing technique was investigated. Also, other techniques for improving a quality of distribution map were discussed. Finally, a procedure was shown for getting qualified misorientation distribution. (author)

  10. Estimating the breast surface using UWB microwave monostatic backscatter measurements.

    Science.gov (United States)

    Winters, David W; Shea, Jacob D; Madsen, Ernest L; Frank, Gary R; Van Veen, Barry D; Hagness, Susan C

    2008-01-01

    This paper presents an algorithm for estimating the location of the breast surface from scattered ultrawideband (UWB) microwave signals recorded across an antenna array. Knowing the location of the breast surface can improve imaging performance if incorporated as a priori information into recently proposed microwave imaging algorithms. These techniques transmit low-power microwaves into the breast using an antenna array, which in turn measures the scattered microwave signals for the purpose of detecting anomalies or changes in the dielectric properties of breast tissue. Our proposed surface identification algorithm consists of three procedures, the first of which estimates M points on the breast surface given M channels of measured microwave backscatter data. The second procedure applies interpolation and extrapolation to these M points to generate N > M points that are approximately uniformly distributed over the breast surface, while the third procedure uses these N points to generate a 3-D estimated breast surface. Numerical as well as experimental tests indicate that the maximum absolute error in the estimated surface generated by the algorithm is on the order of several millimeters. An error analysis conducted for a basic microwave radar imaging algorithm (least-squares narrowband beamforming) indicates that this level of error is acceptable. A key advantage of the algorithm is that it uses the same measured signals that are used for UWB microwave imaging, thereby minimizing patient scan time and avoiding the need for additional hardware. PMID:18232368

  11. Ion beam polishing for three-dimensional electron backscattered diffraction

    DEFF Research Database (Denmark)

    Saowadee, Nath; Agersted, Karsten; Ubhi, H.S.;

    2013-01-01

    Serial sectioning by focused ion beam milling for three-dimensional electron backscatter diffraction (3D-EBSD) can create surface damage and amorphization in certain materials and consequently reduce the EBSD signal quality. Poor EBSD signal causes longer data acquisition time due to signal...... averaging and/or poor 3D-EBSD data quality. In this work a low kV focused ion beam was successfully implemented to automatically polish surfaces during 3D-EBSD of La- and Nb-doped strontium titanate of volume 12.6 × 12.6 × 3.0 μm. The key to achieving this technique is the combination of a defocused low k......V high current ion beam and line scan milling. The line scan was used to restrict polishing to the sample surface and the ion beam was defocused to ensure the beam contacted the complete sample surface. In this study 1 min polishing time per slice increases total acquisition time by approximately 3...

  12. Compton-backscattered annihilation radiation from the Galactic Center region

    Science.gov (United States)

    Smith, D. M.; Lin, R. P.; Feffer, P.; Slassi, S.; Hurley, K.; Matteson, J.; Bowman, H. B.; Pelling, R. M.; Briggs, M.; Gruber, D.

    1993-01-01

    On 1989 May 22, the High Energy X-ray and Gamma-ray Observatory for Nuclear Emissions, a balloon-borne high-resolution germanium spectrometer with an 18-deg FOV, observed the Galactic Center (GC) from 25 to 2500 keV. The GC photon spectrum is obtained from the count spectrum by a model-independent method which accounts for the effects of passive material in the instrument and scattering in the atmosphere. Besides a positron annihilation line with a flux of (10.0 +/- 2.4) x 10 exp -4 photons/sq cm s and a full width at half-maximum (FWHM) of (2.9 + 1.0, -1.1) keV, the spectrum shows a peak centered at (163.7 +/- 3.4) keV with a flux of (1.55 +/- 0.47) x 10 exp -3 photons/sq cm s and a FWHM of (24.4 +/- 9.2) keV. The energy range 450-507 keV shows no positronium continuum associated with the annihilation line, with a 2-sigma upper limit of 0.90 on the positronium fraction. The 164 keV feature is interpreted as Compton backscatter of broadened and redshifted annihilation radiation, possibly from the source 1E 1740.7-2942.

  13. Vacuum birefringence by Compton backscattering through a strong field

    Science.gov (United States)

    Wistisen, Tobias N.; Uggerhøj, Ulrik I.

    2013-09-01

    We propose a novel scheme to measure nonlinear effects in electrodynamics arising from QED corrections. Our theoretical starting point is the Heisenberg-Euler-Schwinger effective Lagrangian which predicts that a vacuum with a strong static electromagnetic field turns birefringent. We propose to employ a pulsed laser to create Compton backscattered photons off a high energy electron beam. These photons will pass through a strong static magnetic field, which according to the QED prediction changes the state of polarization of the radiation—an effect proportional to the photon energy. This change will be measured by using an aligned single crystal, since a large difference in the pair production cross sections at high energies can be achieved with proper orientation of the crystal. As an example we will consider the machine, LHeC, under consideration at CERN as the source of these electrons, and an LHC dipole magnet as the source of the strong static magnetic field. In the proposed experimental setup the birefringence effect will be manifested in a difference in the number of pairs created in the polarizer crystal as the initial laser light has a varying state of polarization, achieved with a rotating quarter wave plate. This will be seen as a clear peak in the Fourier transform spectrum of the pair-production rate signal, which can be obtained with 3 hours of measurement. We also comment on the sensitivity of the experiment, to the existence of an axion, a hypothetical spin-0 particle that couples to two photons.

  14. Wide aperture periodic lens system for multiple Compton backscattering

    CERN Document Server

    Miyahara, Y

    2002-01-01

    Polarized gamma-ray generation by Compton backscattering in a periodic focusing system of electron and laser beams is discussed for the production of polarized positron beam in a linear collider. Circularly polarized CO sub 2 laser beams are focused by an optical lens series and collided with a 5.8 GeV electron beam to generate circularly polarized gamma-rays with 60 MeV at a maximum. In the present work, the basic concept of periodic lens system discussed previously is reconsidered to reduce the laser power required for a gamma-ray yield of 7x10 sup 1 sup 5 gamma/s and the peak laser power density at lenses as much as possible for technical practice. The electron beam is focused by a series of permanent quadrupole magnets with a FODO structure. The power is reduced to six sources with 5.6 kW each, and the peak power density is reduced to 1.4 GW/cm sup 2. These values can be reduced further by using a longer laser pulse length and a damping ring for the electron beam.

  15. Towards high accuracy calibration of electron backscatter diffraction systems

    Energy Technology Data Exchange (ETDEWEB)

    Mingard, Ken [National Physical Laboratory, Hampton Road, Teddington, TW11 0LW (United Kingdom); Day, Austin, E-mail: Austin.Day@ADSci.co.uk [Aunt Daisy Scientific Ltd., Claremont House, Lydney, GL15 5DX (United Kingdom); Maurice, Claire [Ecole des Mines, Centre SMS-UMR CNRS 5146, 158 cours Fauriel, 42023 Saint Etienne Cedex 2 (France); Quested, Peter [National Physical Laboratory, Hampton Road, Teddington, TW11 0LW (United Kingdom)

    2011-04-15

    For precise orientation and strain measurements, advanced Electron Backscatter Diffraction (EBSD) techniques require both accurate calibration and reproducible measurement of the system geometry. In many cases the pattern centre (PC) needs to be determined to sub-pixel accuracy. The mechanical insertion/retraction, through the Scanning Electron Microscope (SEM) chamber wall, of the electron sensitive part of modern EBSD detectors also causes alignment and positioning problems and requires frequent monitoring of the PC. Optical alignment and lens distortion issues within the scintillator, lens and charge-coupled device (CCD) camera combination of an EBSD detector need accurate measurement for each individual EBSD system. This paper highlights and quantifies these issues and demonstrates the determination of the pattern centre using a novel shadow-casting technique with a precision of {approx}10 {mu}m or {approx}1/3 CCD pixel. -- Research highlights: {yields} Issues with accurate EBSD calibration are discussed. {yields} Optical distortion data for 17 EBSD detectors are tabulated. {yields} A new shadow-casting system is demonstrated; it gives a pattern centre precision of {approx}10 {mu}m and allows changes to be observed on the live EBSP.

  16. Surface roughness from MOLA backscatter pulse-widths

    Science.gov (United States)

    Poole, W. D.; Muller, J.-P.; Gupta, S.; Grindrod, P. M.

    2013-09-01

    The time-spread of backscatter laser altimeter pulses, known as pulse-widths, are thought to be capable of being used to infer variations in topography within the footprint of the laser pulse. Here, Mars Orbiter Laser Altimeter (MOLA) pulse-widths have been compared to surface roughness and slope, as measured from high-resolution digital terrain models (DTMs), over different terrains in order to understand how this dataset can be used in the selection of landing and roving sites, and in inferring surface formation and evolution. The results are varied, and suggest that pulsewidths do not respond consistently to variations in terrain. The results show that over Mars Science Laboratory (MSL) candidate landing sites, the pulse-widths can be used as a rough estimate of surface roughness at baselines much larger than the footprint of the pulse. Over much rougher terrain, these pulse-widths respond best to footprint scale slope, which suggests that an additional slope correction for 75 m baselines slopes is required to infer finer scale roughness. However, this is shown not to be the case, as correcting the pulse-widths for 75 m slopes at the MSL candidate sites, and detrending the DTM data, produced poorer results.

  17. Neutral beam species measurements using in situ Rutherford backscatter spectrometry

    International Nuclear Information System (INIS)

    This work describes a new in situ method for measuring the neutral particle fractions in high power deuterium neutral beams, used to heat magnetically confined fusion plasmas. Deuterium beams, of variable energies, pulse lengths, and powers up to 47 keV, 100 msec, 1.6 MW, were Rutherford backscattered at 1350 from TiC inner neutral beam armor of the PDX, and detected using an electrostatic analyzer with microchannel plates. Complete energy scans were made every 20 msec and data were obtained simultaneously from five different positions across the beam profile. The neutral particle fractions were measured to be D0(E):D0(E/2):D0(E/3)=53:32:15. The corresponding neutral power fractions were P0(E):P0(E/2):P0(E/3)=72:21:7, and the associated ionic fractions at the output of the ion source were D1+(E):D2+(E):D3+(E)=74:20:6. The measured neutral particle fractions were relatively constant over more than 70% of the beam power distribution. A decrease in the yield of the full energy component in the outer regions of the beam was observed. Other possible experimental configurations and geometries are discussed

  18. Determination of RF Source Power in WPSN Using Modulated Backscattering

    Directory of Open Access Journals (Sweden)

    K.Sreedhar

    2012-03-01

    Full Text Available A wireless sensor network (WSN is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations. During RF transmission energy consumed by critically energy-constrained sensor nodes in a WSN is related to the life time system, but the life time of the system is inversely proportional to the energy consumed by sensor nodes. In that regard, modulated backscattering (MB is a promising design choice, in which sensor nodes send their data just by switching their antenna impedance and reflecting the incident signal coming from an RF source. Hence wireless passive sensor networks (WPSN designed to operate using MB do not have the lifetime constraints. In this we are going to investigate the system analytically. To obtain interference-free communication connectivity with the WPSN nodes number of RF sources is determined and analyzed in terms of output power and the transmission frequency of RF sources, network size, RF source and WPSN node characteristics. The results of this paper reveal that communication coverage and RF Source Power can be practically maintained in WPSN through careful selection of design parameters

  19. Evaluation of the health risk of body backscatter x ray scanners; Evaluation du risque sanitaire des scanners corporels a rayons X backscatter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Following the attempted attack between Amsterdam and Detroit on the 25 december 2009, the council of interior safety decided a quick display of equipment using more efficient imaging techniques than metals detectors usually in place in French airports. Two technologies of devices are susceptible to be implemented on the airports: scanners using non ionizing radiation, (called millimetric waves) or scanners using ionizing radiation (x radiation, measurement by backscattering called backscatter). This report evaluates the dosimetric impact and the sanitary risk of backscatter x ray scanners and formulates recommendations to authorities to allow them to rule on the type of technology to use. Then, this report gives leads to conceive elements of information to communicate to travelers susceptible to be controlled by a such scanner in a foreign airport. (N.C.)

  20. Calibration of beta-particle ophthalmic applicators at the National Bureau of Standards

    International Nuclear Information System (INIS)

    The method used at the National Bureau of Standards for the calibration of strontium-90 + yttrium-90 beta-particle ophthalmic applicators in terms of absorbed dose to water, is described. The method involves measurement of ionization density at the applicator surface with an extrapolation chamber, correction for the difference in backscatter between the collection electrode and water, and application of the Bragg-Gray equation. The calibration obtained is an average over the active surface of the applicator. The overall uncertainty of the surface calibration is about + or - 15 percent

  1. Obtaining of laue patterns of a copper crystal by backscattering method

    International Nuclear Information System (INIS)

    Diffraction patterns of neutrons were obtained by the Laue method of a copper crystal and using the direct and indirect neutrography techniques. Unlike the conventional diffraction method by transmission, neutrons backscattered were registered which also satisfy the Bragg relation

  2. Influence of lithium coating on the optics of Doppler backscatter system

    International Nuclear Information System (INIS)

    This paper presents the first investigation of the effect of lithium coating on the optics of Doppler backscattering. A liquid lithium limiter has been applied in the Experimental Advanced Superconducting Tokamak (EAST), and a Doppler backscattering has been installed in the EAST. A parabolic mirror and a flat mirror located in the vacuum vessel are polluted by lithium. An identical optical system of the Doppler backscattering is set up in laboratory. The power distributions of the emission beam after the two mirrors with and without lithium coating (cleaned before and after), are measured at three different distances under four incident frequencies. The results demonstrate that the influence of the lithium coating on the power distributions are very slight, and the Doppler backscattering can work normally under the dosage of lithium during the 2014 EAST campaign

  3. Sea Floor Topography and Backscatter Intensity of the Historic Area Remediation Site

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set includes topography and backscatter intensity of the sea floor of the Historic Area Remediation Site (HARS), located offshore of New York and New...

  4. Aerosol backscattering profiles of CO2 wavelengths: the NOAA data base

    International Nuclear Information System (INIS)

    NOAA's data base for aerosol backscattering at lambda = 10.6 μm since May 1981, Boulder, Colorado, is presented together with seasonally averaged profiles and statistical analyses. Studies of the El Chichon event are included

  5. High-frequency over-the-horizon radar and ionospheric backscatter studies in China

    Science.gov (United States)

    Li, Le-Wei

    1998-09-01

    China is one of the countries that employs high-frequency over-the-horizon radars for both military and civil applications. The first Chinese high-frequency over-the horizon backscatter radar was developed in the 1970s. This paper briefly introduces the first Chinese over-the-horizon backscatter radar system and reviews ionospheric backscatter and propagation studies in China. The paper discusses the motivation for establishing over-the-horizon radar systems in China, the experimental system, target recognition and detection,and estimation of over-the-horizon radar availability. Observations of aircraft, large-scale traveling ionospheric disturbances, and the effects of a remote nuclear explosion are also presented. Finally, the real-time Chinese ionosonde network and frequency predictions using backscatter ionograms are discussed.

  6. Fine scale analyses of a coralline bank mapped using multi-beam backscatter data

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, A.A.A.; Naik, M.; Fernandes, W.A.; Haris, K.; Chakraborty, B.; Estiberio, S.; Lohani, R.B.

    In this work, we have developed a classification technique to characterize the seafloor of the Gaveshani (coralline) bank area using multi-beam backscatter data. Softcomputational techniques like the artificial neural networks (ANNs) based...

  7. NOAA TIFF Graphic- 0.5m Backscatter Mosaic of St. Thomas, US Virgin Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 0.5 meter resolution backscatter mosaic of the south shore of St. Thomas, US Virgin Islands.NOAA's NOS/NCCOS/CCMA Biogeography Team and...

  8. Backscatter 0.5m TIFF Mosaic of St. Croix (Buck Island), US Virgin Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 0.5 meter resolution backscatter mosaic of the north shore of Buck Island, St. Croix, US Virgin Islands. NOAA's NOS/NCCOS/CCMA Biogeography...

  9. Effect of grain size distribution on attenuation and backscattered grain noise

    International Nuclear Information System (INIS)

    The attenuation and backscattered grain noises in pure irons were measured. From the backscattered grain noise FOM (Figure-of-merit) which is a material dependent parameter were obtained by using independent scattering model. Attenuation coefficients and FOM's were compared with the results calculated by LPM theory and the general scattering model, respectively. Although the absolute values were not exactly same between measured and calculated results, the dependencies of them on the average grain size could be confirmed. The effect of grain size distribution on attenuation and backscattered grain noise was analyzed. The different scattering mechanisms according to the ratio of wavelength to grain size were applied to the analysis of the attenuation and backscattering even in a specimen.

  10. The application possibilities of the gamma-ray Compton backscattering technique

    Science.gov (United States)

    Flechas, D.; Sarmiento, L. G.; González, N.; Gómez-Muñoz, J.; Garzón, C.; Fajardo, E.; Cristancho, F.

    2013-05-01

    The location of objects hidden in dense matter and the analysis of metallic surfaces using gamma backscattering are two possible applications strongly suggested here with experiments, highlevel Monte Carlo simulations, and some supporting basic theory.

  11. Assessment of Multiple Delamination in Laminated Composites for Aircrafts using X-ray Backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Noh Yu [College of Medicine, Hanyang University, Cheonan (Korea, Republic of)

    2010-02-15

    A Compton X-ray backscatter technique has been developed to quantitatively assess impact damage in quasi-isotropic laminated composites made by a drop-weight tester. X-ray backscatter imaging system with a slit-type camera is constructed to obtain a cross-sectional profile of impact-damaged laminated composites from the electron-density variation of the cross section. A nonlinear scattering model based on Boltsman equation is introduced to compute Compton X-ray backscattering field for the defect assessment. An adaptive filter is also used to reduce noises from many sources including quantum noise and irregular distributions of fibers and matrix in composites. Delaminations masked or distorted by the first delamination are detected and characterized effectively by the Compton X-ray backscatter technique, both in width and location, by application of error minimization algorithm

  12. Landmine detection method combined with backscattering neutrons and capture {gamma}-rays from hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Yoshiyuki, E-mail: ytaka@rri.kyoto-u.ac.j [Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Misawa, Tsuyoshi; Pyeon, Cheol Ho; Shiroya, Seiji [Research Reactor Institute, Kyoto University, Asashiro-nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Yoshikawa, Kiyoshi [Institute of Advanced Energy, Kyoto University, Gokashou, Uji-shi, Kyoto 611-0011 (Japan)

    2011-07-15

    The usefulness of the measurements of the backscattering neutron and 2.22 MeV capture {gamma}-ray from hydrogen in the landmine detection method is described in this paper. When the soil moisture content is increased, the reaction rates of both the neutron scattering reaction and capture reaction are increased. However, the backscattering neutrons are more influenced than the capture {gamma}-rays by the soil moisture before the reaction with the detector. The facts that the backscattering neutron method is useful in the dry soil case and that the capture {gamma}-ray method is effective in well-wet soil case are confirmed by the experiments and the calculations. The landmine detection efficiency is improved in various soil moisture conditions by combining the backscattering neutron method together with the capture {gamma}-ray method. The effectiveness of the pulse mode operation was confirmed numerically.

  13. Backscatter 0.5m TIFF Mosaic of St. Thomas, US Virgin Islands, 2004

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This image represents a 0.5 meter resolution backscatter mosaic of the south shore of St. Thomas, US Virgin Islands. NOAA's NOS/NCCOS/CCMA Biogeography Team and...

  14. Backscattering Light Model of Seawater for Modulated Lidar Based on the Stationarity of Light Field

    Institute of Scientific and Technical Information of China (English)

    JI Hang; MA Yong; LIANG Kun; WANG Hong-yuan

    2007-01-01

    The backscattering signal, which arises from the pulsed laser traveling through water, has limited the lidar system sensitivity and underwater target contrast. The transmitted optical carrier is modulated to be ultrashort pulsed laser and i t is effective to suppress the backscattering to adopt the coherent detection technology by identifying the modulation envelope. A nonstationary light field is formed in seawater by the ultrashort pulsed laser. The inherent relationship between the nonstationary light field formed by modulated lidar and the stationary light field formed by conventional lidar was discussed and the backscattering light model of the stationary light field for the ultrashort pulsed laser was proposed. The backscattering signal in modulated lidar system was processed and analyzed in the frequency domain on the basis of the model.

  15. CRED Reson 8101 multibeam backscatter data from the islands and banks in the Mariana archipelago, 2007.

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Multibeam backscatter imagery extracted from gridded bathymetry of the Mariana archipelago between the U.S. Territory of Guam and Uracas Island in the Commonwealth...

  16. Automatically determining the origin direction and propagation mode of high-frequency radar backscatter

    Science.gov (United States)

    Burrell, Angeline G.; Milan, Stephen E.; Perry, Gareth W.; Yeoman, Timothy K.; Lester, Mark

    2015-12-01

    Elevation angles of returned backscatter are calculated at Super Dual Auroral Radar Network radars using interferometric techniques. These elevation angles allow the altitude of the reflection point to be estimated, an essential piece of information for many ionospheric studies. The elevation angle calculation requires knowledge of the azimuthal return angle. This directional angle is usually assumed to lie along a narrow beam from the front of the radar, even though the signals are known to return from both in front of and behind the radar. If the wrong direction of return is assumed, large uncertainties will be introduced through the azimuthal return angle. This paper introduces a means of automatically determining the correct direction of arrival and the propagation mode of backscatter. The application of this method will improve the accuracy of backscatter elevation angle data and aid in the interpretation of both ionospheric and ground backscatter observations.

  17. Reson 8101 Backscatter imagery of Ni'ihau Island, Hawaii, USA

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Backscatter imagery extracted from gridded bathymetry of Ni'ihau Island, Hawaii, USA. These data provide almost complete coverage between 0 and 100 meters. The...

  18. Extracting integrated and differential cross sections in low energy heavy-ion reactions from backscattering measurements

    Science.gov (United States)

    Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.; Diaz-Torres, A.; Gomes, P. R. S.; Lenske, H.

    2016-07-01

    We suggest new methods to extract elastic (quasi-elastic) scattering angular distribution and reaction (capture) cross sections from the experimental elastic (quasi-elastic) backscattering excitation function taken at a single angle.

  19. Vertical Aerosol Backscatter Variability from an Airborne Focused Continuous Wave CO2 Lidar

    Science.gov (United States)

    Jarzembski, Maurice A.; Srivastava, Vandana; Rothermel, Jeffry

    1998-01-01

    Atmospheric aerosol backscatter measurements using a continuous wave focused Doppler lidar at 9.1 micron wavelength were obtained over western North America and the Pacific Ocean during 13 - 26 September, 1995 as part of National Aeronautics and Space Administration's (NASA) Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) mission on board the NASA DC8 aircraft. Backscatter variability was measured for approximately 52 flight hours, covering equivalent horizontal distance of approximately 25,000 km in the troposphere. Quasi-vertical backscatter profiles were also obtained during various ascents and descents which ranged between approximately 0.1 to 12.0 km altitude. Aerosol haze layers were encountered at different altitudes. Similarities and differences for aerosol loading over land and over ocean were observed. A mid-tropospheric aerosol backscatter background mode was found with modal value approximately 1O(exp -10)/m/sr, consistent with previous airborne and ground-based datasets.

  20. Influence of lithium coating on the optics of Doppler backscatter system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X. H.; Liu, A. D., E-mail: lad@ustc.edu.cn; Zhou, C.; Hu, J. Q.; Wang, M. Y.; Yu, C. X.; Liu, W. D.; Li, H.; Lan, T.; Xie, J. L. [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2015-10-15

    This paper presents the first investigation of the effect of lithium coating on the optics of Doppler backscattering. A liquid lithium limiter has been applied in the Experimental Advanced Superconducting Tokamak (EAST), and a Doppler backscattering has been installed in the EAST. A parabolic mirror and a flat mirror located in the vacuum vessel are polluted by lithium. An identical optical system of the Doppler backscattering is set up in laboratory. The power distributions of the emission beam after the two mirrors with and without lithium coating (cleaned before and after), are measured at three different distances under four incident frequencies. The results demonstrate that the influence of the lithium coating on the power distributions are very slight, and the Doppler backscattering can work normally under the dosage of lithium during the 2014 EAST campaign.

  1. Correction of Doppler-broadened Rayleigh backscattering effects in H2O dial measurements

    Science.gov (United States)

    Ansmann, A.; Bosenberg, J.

    1986-01-01

    A general method of solutions for treating effects of Doppler-broadened Rayleigh backscattering in H2O Differential Absorption Lidar (DIAL) measurements are described and discussed. Errors in vertical DIAL measuremtns caused by this laser line broadening effect can be very large and, therfore, this effect has to be accounted for accurately. To analyze and correct effects of Doppler-broadened Rayleigh backscattering in DIAL experiments, a generalized DIAL approximation was derived starting from a lidar equation, which includes Doppler broadening. To evaluate the accuracy of H2O DIAL measurements, computer simulations were performed. It was concluded that correction of Doppler broadened Rayleigh backscattering is possible with good accuracy in most cases of tropospheric H2O DIAL measurements, but great care has to be taken when layers with steep gradients of Mie backscattering like clouds or inversion layers are present.

  2. A Compact In Situ Sensor for Measurement of Absorption and Backscattering in Natural Waters Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop an active sensor for in situ measurement of the inherent optical properties (IOPs) absorption and backscattering at multiple wavelengths....

  3. Xeroradiography in. beta. -thalassaemia

    Energy Technology Data Exchange (ETDEWEB)

    Scutellari, P.N.; Orzincolo, C.; Tamarozzi, R.

    1985-01-01

    Xeroradiographic investigations of the skull, hand, and elbow were performed on 27 patients with homozygous ..beta..-thalassaemia. The results were compared with plain radiographic examinations. Xeroradiography, because of its technical properties (i.e. edge contrast enhancement and wide latitude), was shown to demonstrate cortical thinning of long bones, swelling of the diploic space in the skull, and reticulated patterns in the elbow better than standard radiography. Moreover, the use of 'positive' mode imaging was shown to have advantages in the study of the skull and extremities.

  4. Realized Beta GARCH

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri Radkov

    2014-01-01

    particularly useful for modeling financial returns during periods of rapid changes in the underlying covariance structure. When applied to market returns in conjunction with returns on an individual asset, the model yields a dynamic model specification of the conditional regression coefficient that is known as...... conditional beta series during the financial crises.......We introduce a multivariate generalized autoregressive conditional heteroskedasticity (GARCH) model that incorporates realized measures of variances and covariances. Realized measures extract information about the current levels of volatilities and correlations from high-frequency data, which is...

  5. Resolving subwavelength objects with a crossed wire mesh superlens operated in backscattering mode

    Energy Technology Data Exchange (ETDEWEB)

    Silveirinha, Mario G [Department of Electrical Engineering-Instituto de Telecomunicacoes, University of Coimbra (Portugal); Medeiros, Carla R; Fernandes, Carlos A; Costa, Jorge R, E-mail: mario.silveirinha@co.it.pt [Technical University of Lisbon, Instituto Superior Tecnico-Instituto de Telecomunicacoes, 1049-001 Lisbon (Portugal)

    2011-05-15

    In this work, we demonstrate that a crossed-wires superlens operated in backscattering mode can resolve targets separated by a subwavelength distance. It is theoretically shown that the effect of the backscattered field on the return loss of a probe antenna is sufficiently strong to allow us to discriminate the targets over a broad range of frequencies. These properties have been experimentally confirmed at microwave frequencies.

  6. Resolving subwavelength objects with a crossed wire mesh superlens operated in backscattering mode

    International Nuclear Information System (INIS)

    In this work, we demonstrate that a crossed-wires superlens operated in backscattering mode can resolve targets separated by a subwavelength distance. It is theoretically shown that the effect of the backscattered field on the return loss of a probe antenna is sufficiently strong to allow us to discriminate the targets over a broad range of frequencies. These properties have been experimentally confirmed at microwave frequencies.

  7. Theoretical analysis of backscattered polarization patterns of turbid media containing glucose

    Institute of Scientific and Technical Information of China (English)

    Lanqing Xu; Hui Li; Shusen Xie

    2007-01-01

    Single scattering model and Stokes-Mueller formalism are introduced to investigate the influence of glucose on backscattered polarization patterns in turbid media. Glucose molecules rotate the polarization plane and induce changes in backscattered Mueller matrix patterns. Some Mueller matrix elements present higher optical rotation as the concentration of glucose augments. Using image subtraction and integration,linear relationship between low glucose concentration in the physiological range and optical rotation degree can be derived.

  8. A Monte Carlo computer program for analysis of backscattering and sputtering in practical vacuum systems

    International Nuclear Information System (INIS)

    A Monte Carlo computer program originally developed for analysis of molecular gas flow in axi-symmetric vacuum systems has been extended to include modelling of high energy backscattering and sputtering processes. This report describes the input data required by the computer program together with the results produced. A general description is given of the program operation and the backscattering and sputtering modelling used. An example calculation is included to illustrate practical application of the program. (author)

  9. Climatology of the aerosol extinction to backscatter ratio from sun photometric measurements

    OpenAIRE

    Baldasano Recio, José María; Pedrós, Roberto; Estallés, Víctor; Sicard, Michaël; Gómez Amo, Jose Luis; Utrillas, Maria Pilar; Martínez Lozano, José Antonio; Rocadenbosch Burillo, Francisco; Pérez, C.

    2010-01-01

    The elastic lidar equation contains two unknown atmospheric parameters, namely, the particulate optical extinction and backscatter coefficients, which are related through the lidar ratio (i.e., the particulate-extinction-to-backscatter ratio). So far, independent inversion of the lidar signal has been carried out by means of Raman lidars (usually limited to nighttime measurements), high-spectral-resolution lidars, or scanning elastic lidars under the assumption of a homog...

  10. An analytical model for backscattered luminance in fog: comparisons with Monte Carlo computations and experimental results

    OpenAIRE

    Taillade, Frédéric; Belin, Etienne; Dumont, Eric

    2008-01-01

    We propose an analytical model for backscattered luminance in fog and derive an expression for the visibility signal-to-noise ratio as a function of meteorological visibility distance. The model uses single scattering processes. It is based on the Mie theory and the geometry of the optical device (emitter and receiver). In particular, we present an overlap function and take the phase function of fog into account. The results of the backscattered luminance obtained with our analytical model...

  11. Calculation of the backscattered ion energy and angular distributions during the grazing implantation

    International Nuclear Information System (INIS)

    Simulation of ion implantation into deep trenches demands the exact evaluation of ion fluxes backscattered from the sidewalls. In this paper an application of Boltzmann Transport Equation (BTE) to backscattered ion energy and angular distribution calculations is presented. Characteristic examples of grazing implantation of Sb, As and P in Si are considered and good agreement with Monte-Carlo (MC) calculations are found. It was also found that BTE gives a more smooth distribution without statistical fluctuations and essentially saves computational time. (author)

  12. An integral model for thermal backscattering from the exhaust plume of space-based HF laser

    OpenAIRE

    Falcovitz, Joseph; Fuhs, Allen E.

    1986-01-01

    The operation of a space-based HF laser may be hampered due to self contamination by corrosive exhaust products. We estimate one effect contributing to contaminating blackflow: thermal backscattering from the rarefaction fans flanking the exhaust ring-jet. Our computational model is based on a first-iterate approximation to the Boltzmann equation in integral form. Results indicate that thermal backscattering of corrosive speies (HF, DF) is negligible.

  13. Radio-analysis of hydrogenous material using neutron back-scattering technique

    International Nuclear Information System (INIS)

    In this work, we have explored the possibility of using neutron back-scattering technique in performing radio analysis for samples of hydrogenous materials such as explosives, drugs, crude oil and water, looking for different signals that may be used to discriminate these samples. Monte Carlo simulations were carried out to model the detection system and select the optimal geometry as well. The results were determined in terms of the energy spectra of the back-scattered neutrons.(Author)

  14. Modeling the effects of laser-beam smoothing on filamentation and stimulated Brillouin backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Berger, R.L.; Kaiser, T.B.; Lasinski, B.F. [and others

    1996-06-01

    Using the three-dimensional code (F3D), the authors compute the filamentation and backscattering of laser light. The results show that filamentation can be controlled and stimulated Brillouin backscattering (SBBS) can be reduced by using random phase plates (RPP) and small f-numbers or smoothing by spectral dispersion (SSD) with large bandwidth. An interesting result is that, for uniform plasmas, the SBBS amplification takes place over several laser axial coherence lengths (coherence length = speckle length).

  15. The backscatter cloud probe – a compact low-profile autonomous optical spectrometer

    OpenAIRE

    K. Beswick; Baumgardner, D; Gallagher, M; Volz-Thomas, A.; Nedelec, P.; K.-Y. Wang; LANCE, S.

    2014-01-01

    A compact (500 cm3), lightweight (500 g), near-field, single particle backscattering optical spectrometer is described that mounts flush with the skin of an aircraft and measures the concentration and optical equivalent diameter of particles from 5 to 75 μm. The backscatter cloud probe (BCP) was designed as a real-time qualitative cloud detector primarily for data quality control of trace gas instruments developed for the climate monitoring instrument packages that are being...

  16. Enhanced Doppler Effect in the Upper Hybrid Resonance Microwave Backscattering Experiment

    OpenAIRE

    Altukhov, A.B.; Gurchenko, A.D.; Gusakov, E. Z.; Esipov, L. A.; Lashkul, S. I.; Stepanov, A. Yu.

    2004-01-01

    Observations of enhanced Doppler frequency shift effect of the highly localized microwave backscattering in the upper hybrid resonance are reported. The experiment is performed at FT-2 tokamak, where a steerable focusing antenna set, allowing off equatorial plane plasma extraordinary wave probing from high magnetic field side, was installed. A separate line less than 1.5 MHz wide and shifted by up to 2 MHz is routinely observed in the backscattering spectrum under condition of accessible uppe...

  17. Diffusion of Sr in fluorphlogopite determined by Rutherford backscattering spectrometry

    Science.gov (United States)

    Hammouda, T.; Cherniak, D. J.

    2000-05-01

    We have measured the diffusivity of Sr in fluorphlogopite in a direction perpendicular to the basal planes (in the c direction). Annealing experiments were performed on single crystals, and most of them at ambient pressure. The penetration profiles of the diffusant were determined by Rutherford backscattering spectrometry. Sr diffusion parallel to c obeys an Arrhenius law, whose equation is: D Sr=2.7·10 -14 exp - 13 5900±3100/RTwhere DSr is given in m 2 s -1 and activation energy in J mol -1. The values measured in fluorphlogopite overlap the range previously determined in other silicates, but the activation energy for fluorphlogopite is approximately half that of the other minerals for which diffusion data exist. A summary of the available data on diffusion in micas of all compositions shows that activation energies for species such as Sr, O, Rb and K fall in the same range, i.e. 100-175 kJ per mol. When plotted together, these data define two groups of parallel Arrhenian lines. One group consists of the measurements performed in the c direction, the other of those performed normal to the c direction. The distinction between the two groups is clear, and diffusion parallel to the c direction is slower by several orders of magnitude. The corresponding closure temperature for fluorphlogopite, when diffusion occurs in the c direction, is of the order of 700°C, relatively close to that of feldspars. On the basis of some simple assumptions about diffusion anisotropy in micas, we also estimated the closure temperature when diffusion takes place in a direction parallel to the basal planes. In that case, the value is noticeably lower, of the order of 400°C. However, this value, if applicable to other micas, is higher than what is currently accepted, which could have some implications for models of thermal histories or uplift rates of rocks.

  18. Double beta decay: present status

    OpenAIRE

    Barabash, A. S.

    2008-01-01

    The present status of double beta decay experiments (including the search for $2\\beta^{+}$, EC$\\beta^{+}$ and ECEC processes) are reviewed. The results of the most sensitive experiments are discussed. Average and recommended half-life values for two-neutrino double beta decay are presented. Conservative upper limits on effective Majorana neutrino mass and the coupling constant of the Majoron to the neutrino are established as $ < 0.75$ eV and $ < 1.9 \\cdot 10^{-4}$, respectively. Proposals fo...

  19. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  20. Cavitation inception by the backscattering of pressure waves from a bubble interface

    Science.gov (United States)

    Takahira, Hiroyuki; Ogasawara, Toshiyuki; Mori, Naoto; Tanaka, Moe

    2015-10-01

    The secondary cavitation that occurs by the backscattering of focused ultrasound from a primary cavitation bubble caused by the negative pressure part of the ultrasound (Maxwell, et al., 2011) might be useful for the energy exchange due to bubble oscillations in High Intensity Focused Ultrasound (HIFU). The present study is concerned with the cavitation inception by the backscattering of ultrasound from a bubble. In the present experiment, a laser-induced bubble which is generated by a pulsed focused laser beam with high intensity is utilized as a primary cavitation bubble. After generating the bubble, focused ultrasound is emitted to the bubble. The acoustic field and the bubble motion are observed with a high-speed video camera. It is confirmed that the secondary cavitation bubble clouds are generated by the backscattering from the laser-induced bubble. The growth of cavitation bubble clouds is analyzed with the image processing method. The experimental results show that the height and width of the bubble clouds grow in stepwise during their evolution. The direct numerical simulations are also conducted for the backscattering of incident pressure waves from a bubble in order to evaluate a pressure field near the bubble. It is shown that the ratio of a bubble collapse time t0 to a characteristic time of wave propagation tS, η = t0/ts, is an important determinant for generating negative pressure region by backscattering. The minimum pressure location by the backscattering in simulations is in good agreement with the experiment.