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Sample records for absorbance values measured

  1. Establishing traceability of photometric absorbance values for accurate measurements of the haemoglobin concentration in blood

    NASA Astrophysics Data System (ADS)

    Witt, K.; Wolf, H. U.; Heuck, C.; Kammel, M.; Kummrow, A.; Neukammer, J.

    2013-10-01

    Haemoglobin concentration in blood is one of the most frequently measured analytes in laboratory medicine. Reference and routine methods for the determination of the haemoglobin concentration in blood are based on the conversion of haeme, haemoglobin and haemiglobin species into uniform end products. The total haemoglobin concentration in blood is measured using the absorbance of the reaction products. Traceable absorbance measurement values on the highest metrological level are a prerequisite for the calibration and evaluation of procedures with respect to their suitability for routine measurements and their potential as reference measurement procedures. For this purpose, we describe a procedure to establish traceability of spectral absorbance measurements for the haemiglobincyanide (HiCN) method and for the alkaline haematin detergent (AHD) method. The latter is characterized by a higher stability of the reaction product. In addition, the toxic hazard of cyanide, which binds to the iron ion of the haem group and thus inhibits the oxygen transport, is avoided. Traceability is established at different wavelengths by applying total least-squares analysis to derive the conventional quantity values for the absorbance from the measured values. Extrapolation and interpolation are applied to get access to the spectral regions required to characterize the Q-absorption bands of the HiCN and AHD methods, respectively. For absorbance values between 0.3 and 1.8, the contributions of absorbance measurements to the total expanded uncertainties (95% level of confidence) of absorbance measurements range from 1% to 0.4%.

  2. Method of absorbance correction in a spectroscopic heating value sensor

    SciTech Connect

    Saveliev, Alexei; Jangale, Vilas Vyankatrao; Zelepouga, Sergeui; Pratapas, John

    2013-09-17

    A method and apparatus for absorbance correction in a spectroscopic heating value sensor in which a reference light intensity measurement is made on a non-absorbing reference fluid, a light intensity measurement is made on a sample fluid, and a measured light absorbance of the sample fluid is determined. A corrective light intensity measurement at a non-absorbing wavelength of the sample fluid is made on the sample fluid from which an absorbance correction factor is determined. The absorbance correction factor is then applied to the measured light absorbance of the sample fluid to arrive at a true or accurate absorbance for the sample fluid.

  3. Solar absorber material reflectivity measurements at temperature

    SciTech Connect

    Bonometti, J.A.; Hawk, C.W.

    1999-07-01

    Assessment of absorber shell material properties at high operating temperatures is essential to the full understanding of the solar energy absorption process in a solar thermal rocket. A review of these properties, their application and a new experimental methodology to measure them at high temperatures is presented. The direct application for the research is absorber cavity development for a Solar Thermal Upper Stage (STUS). High temperature measurements, greater than 1,000 Kelvin, are difficult to obtain for incident radiation upon a solid surface that forms an absorber cavity in a solar thermal engine. The basic material properties determine the amount of solar energy that is absorbed, transmitted or reflected and are dependent upon the material's temperature. This investigation developed a new approach to evaluate the material properties (i.e., reflectivity, absorptive) of the absorber wall and experimentally determined them for rhenium and niobium sample coupons. The secular reflectivity was measured both at room temperature and at temperatures near 1,000 Kelvin over a range of angles from 0 to 90 degrees. The same experimental measurements were used to calculate the total reflectivity of the sample by integrating the recorded intensities over a hemisphere. The test methodology used the incident solar energy as the heating source while directly measuring the reflected light (an integrated value over all visible wavelengths). Temperature dependence on total reflectivity was found to follow an inverse power function of the material's temperature.

  4. Absorbed dose measurements and predictions on LDEF

    NASA Technical Reports Server (NTRS)

    Frank, A. L.; Benton, E. V.; Armstrong, T. W.; Colborn, B. L.

    1993-01-01

    The overall radiation environment of the Long Duration Exposure Facility (LDEF) was determined in part through the use of thermoluminescent detectors (TLD's) which were included in several experiments. The results given are from four experiments (A0015 Biostack, M0004 Fiber Optics Data Link, P0004 Seeds in Space, and P0006 Linear Energy Transfer Spectrum Measurement) and represent a large fraction of existing absorbed dose data. The TLD's were located on the leading and the trailing edges and the Earth end of the spacecraft under various shielding depths (0.48 to 15.4 g/sq cm). The measured absorbed doses were found to reflect both directional dependence of incident trapped protons and shielding. At the leading edge, doses ranged from 2.10 to 2.58 Gy under shielding of 2.90 to 1.37 g/sq cm Al equivalent (M0004). At the trailing edge, doses varied from 3.04 to 4.49 Gy under shielding of 11.7 to 3.85 g/sq cm (A0015), doses varied from 2.91 to 6.64 Gy under shielding of 11.1 to 0.48 g/sq cm (P0004), and a dose range of 2.66 to 6.48 Gy was measured under shielding of 15.4 to 0.48 g/sq cm (P0006). At the Earth end of the spacecraft, doses from 2.41 to 3.93 Gy were found under shielding of 10.0 to 1.66 g/sq cm (A0015). The effect of the trapped proton anisotropy was such that the western side of LDEF received more than 2 times the dose of the eastern side at shielding depths of approximately 1 g/sq cm. Calculations utilizing a directional model of trapped proton spectra predict smaller doses than those measured, being about 50 percent of measured values at the trailing edge and Earth end, and about 80 percent near the leading edge.

  5. DHCAL with minimal absorber: measurements with positrons

    NASA Astrophysics Data System (ADS)

    Freund, B.; Neubüser, C.; Repond, J.; Schlereth, J.; Xia, L.; Dotti, A.; Grefe, C.; Ivantchenko, V.; Berenguer Antequera, J.; Calvo Alamillo, E.; Fouz, M.-C.; Marin, J.; Puerta-Pelayo, J.; Verdugo, A.; Brianne, E.; Ebrahimi, A.; Gadow, K.; Göttlicher, P.; Günter, C.; Hartbrich, O.; Hermberg, B.; Irles, A.; Krivan, F.; Krüger, K.; Kvasnicka, J.; Lu, S.; Lutz, B.; Morgunov, V.; Provenza, A.; Reinecke, M.; Sefkow, F.; Schuwalow, S.; Tran, H. L.; Garutti, E.; Laurien, S.; Matysek, M.; Ramilli, M.; Schroeder, S.; Bilki, B.; Norbeck, E.; Northacker, D.; Onel, Y.; Cvach, J.; Gallus, P.; Havranek, M.; Janata, M.; Kovalcuk, M.; Kvasnicka, J.; Lednicky, D.; Marcisovsky, M.; Polak, I.; Popule, J.; Tomasek, L.; Tomasek, M.; Sicho, P.; Smolik, J.; Vrba, V.; Zalesak, J.; van Doren, B.; Wilson, G. W.; Kawagoe, K.; Hirai, H.; Sudo, Y.; Suehara, T.; Sumida, H.; Takada, S.; Tomita, T.; Yoshioka, T.; Bilokin, S.; Bonis, J.; Cornebise, P.; Pöschl, R.; Richard, F.; Thiebault, A.; Zerwas, D.; Hostachy, J.-Y.; Morin, L.; Besson, D.; Chadeeva, M.; Danilov, M.; Markin, O.; Popova, E.; Gabriel, M.; Goecke, P.; Kiesling, C.; van der Kolk, N.; Simon, F.; Szalay, M.; Corriveau, F.; Blazey, G. C.; Dyshkant, A.; Francis, K.; Zutshi, V.; Kotera, K.; Ono, H.; Takeshita, T.; Ieki, S.; Kamiya, Y.; Ootani, W.; Shibata, N.; Jeans, D.; Komamiya, S.; Nakanishi, H.

    2016-05-01

    In special tests, the active layers of the CALICE Digital Hadron Calorimeter prototype, the DHCAL, were exposed to low energy particle beams, without being interleaved by absorber plates. The thickness of each layer corresponded approximately to 0.29 radiation lengths or 0.034 nuclear interaction lengths, defined mostly by the copper and steel skins of the detector cassettes. This paper reports on measurements performed with this device in the Fermilab test beam with positrons in the energy range of 1 to 10 GeV. The measurements are compared to simulations based on GEANT4 and a standalone program to emulate the detailed response of the active elements.

  6. Measuring Nursing Care Value.

    PubMed

    Welton, John M; Harper, Ellen M

    2016-01-01

    The value of nursing care as well as the contribution of individual nurses to clinical outcomes has been difficult to measure and evaluate. Existing health care financial models hide the contribution of nurses; therefore, the link between the cost and quality o nursing care is unknown. New data and methods are needed to articulate the added value of nurses to patient care. The final results and recommendations of an expert workgroup tasked with defining and measuring nursing care value, including a data model to allow extraction of key information from electronic health records to measure nursing care value, are described. A set of new analytic metrics are proposed. PMID:27055306

  7. Absorber Alignment Measurement Tool for Solar Parabolic Trough Collectors: Preprint

    SciTech Connect

    Stynes, J. K.; Ihas, B.

    2012-04-01

    As we pursue efforts to lower the capital and installation costs of parabolic trough solar collectors, it is essential to maintain high optical performance. While there are many optical tools available to measure the reflector slope errors of parabolic trough solar collectors, there are few tools to measure the absorber alignment. A new method is presented here to measure the absorber alignment in two dimensions to within 0.5 cm. The absorber alignment is measured using a digital camera and four photogrammetric targets. Physical contact with the receiver absorber or glass is not necessary. The alignment of the absorber is measured along its full length so that sagging of the absorber can be quantified with this technique. The resulting absorber alignment measurement provides critical information required to accurately determine the intercept factor of a collector.

  8. Techniques for measuring intercepted and absorbed PAR in corn canopies

    NASA Technical Reports Server (NTRS)

    Gallo, K. P.; Daughtry, C. S. T.

    1984-01-01

    The quantity of radiation potentially available for photosynthesis that is captured by the crop is best described as absorbed photosynthetically active radiation (PAR). Absorbed PAR (APAR) is the difference between descending and ascending fluxes. The four components of APAR were measured above and within two planting densities of corn (Zea mays L.) and several methods of measuring and estimating APAR were examined. A line quantum sensor that spatially averages the photosynthetic photon flux density provided a rapid and portable method of measuring APAR. PAR reflectance from the soil (Typic Argiaquoll) surface decreased from 10% to less than 1% of the incoming PAR as the canopy cover increased. PAR reflectance from the canopy decreased to less than 3% at maximum vegetative cover. Intercepted PAR (1 - transmitted PAR) generally overestimated absorbed PAR by less than 4% throughout most of the growing season. Thus intercepted PAR appears to be a reasonable estimate of absorbed PAR.

  9. Simultaneous measurements of absorbed dose and linear energy transfer in therapeutic proton beams

    NASA Astrophysics Data System (ADS)

    Granville, Dal A.; Sahoo, Narayan; Sawakuchi, Gabriel O.

    2016-02-01

    The biological response resulting from proton therapy depends on both the absorbed dose in the irradiated tissue and the linear energy transfer (LET) of the beam. Currently, optimization of proton therapy treatment plans is based only on absorbed dose. However, recent advances in proton therapy delivery have made it possible to vary the LET distribution for potential therapeutic gain, leading to investigations of using LET as an additional parameter in plan optimization. Having a method to measure and verify both absorbed dose and LET as part of a quality assurance program would be ideal for the safe delivery of such plans. Here we demonstrated the potential of an optically stimulated luminescence (OSL) technique to simultaneously measure absorbed dose and LET. We calibrated the ratio of ultraviolet (UV) to blue emission intensities from Al2O3:C OSL detectors as a function of LET to facilitate LET measurements. We also calibrated the intensity of the blue OSL emission for absorbed dose measurements and introduced a technique to correct for the LET-dependent dose response of OSL detectors exposed to therapeutic proton beams. We demonstrated the potential of our OSL technique by using it to measure LET and absorbed dose under new irradiation conditions, including patient-specific proton therapy treatment plans. In the beams investigated, we found the OSL technique to measure dose-weighted LET within 7.9% of Monte Carlo-simulated values and absorbed dose within 2.5% of ionization chamber measurements.

  10. Simultaneous measurements of absorbed dose and linear energy transfer in therapeutic proton beams.

    PubMed

    Granville, Dal A; Sahoo, Narayan; Sawakuchi, Gabriel O

    2016-02-21

    The biological response resulting from proton therapy depends on both the absorbed dose in the irradiated tissue and the linear energy transfer (LET) of the beam. Currently, optimization of proton therapy treatment plans is based only on absorbed dose. However, recent advances in proton therapy delivery have made it possible to vary the LET distribution for potential therapeutic gain, leading to investigations of using LET as an additional parameter in plan optimization. Having a method to measure and verify both absorbed dose and LET as part of a quality assurance program would be ideal for the safe delivery of such plans. Here we demonstrated the potential of an optically stimulated luminescence (OSL) technique to simultaneously measure absorbed dose and LET. We calibrated the ratio of ultraviolet (UV) to blue emission intensities from Al2O3:C OSL detectors as a function of LET to facilitate LET measurements. We also calibrated the intensity of the blue OSL emission for absorbed dose measurements and introduced a technique to correct for the LET-dependent dose response of OSL detectors exposed to therapeutic proton beams. We demonstrated the potential of our OSL technique by using it to measure LET and absorbed dose under new irradiation conditions, including patient-specific proton therapy treatment plans. In the beams investigated, we found the OSL technique to measure dose-weighted LET within 7.9% of Monte Carlo-simulated values and absorbed dose within 2.5% of ionization chamber measurements. PMID:26859539

  11. Measurements of Light Absorbing Particles on Tropical South American Glaciers

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J.; Schwarz, J. P.; Arnott, W. P.; Warthon, J.; Andrade, M.; Celestian, A. J.; Hoffmann, D.; Cole, R. J.; Lapham, E.; Horodyskyj, U. N.; Froyd, K. D.; Liao, J.

    2014-12-01

    Glaciers in the tropical Andes have been losing mass rapidly in recent decades. In addition to the documented increase in temperature, increases in light absorbing particulates deposited on glaciers could be contributing to the observed glacier loss. Here we present results of measurements of light absorbing particles from glaciers in Peru and Bolivia. Samples have been collected by American Climber Science Program volunteers and scientists at altitudes up to 6770 meters. Collected snow samples were melted and filtered in the field. A new inexpensive technique, the Light Absorption Heating Method (LAHM) has been developed for analysis of light absorbing particles collected on filters. Results from LAHM analysis are calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). For snow samples collected at the same field location LAHM analysis and measurements from the Single Particle Soot Photometer (SP2) instrument are well correlated (r2 = 0.92). Co-located SP2 and LAHM filter analysis suggest that BC could be the dominant absorbing component of the light absorbing particles in some areas.

  12. A portable absorbed dose measuring instrument with gamma discrimination

    NASA Technical Reports Server (NTRS)

    Quam, W. M.; Wilde, W. I.

    1972-01-01

    The characteristics of an electronic instrument for measuring the radiation dose absorbed by tissues are presented. The detector is a sphere of tissue-equivalent plastic with a single wire located on a diameter of the sphere. The electronic circuits and method of operation of the detector are described. Advantages are the small size and easy portability plus ability to selectively measure neutron and gamma plus neutron events.

  13. Alternative Ear-Canal Measures Related to Absorbance

    PubMed Central

    Neely, Stephen T.; Stenfelt, Stefan; Schairer, Kim S.

    2013-01-01

    Several alternative ear-canal measures are similar to absorbance in their requirement for prior determination of a Thévenin-equivalent sound source. Examples are (1) sound intensity level (SIL), (2) forward-pressure level (FPL), (3) time-domain ear-canal reflectance (TDR), and (4) cochlear reflectance (CR). These four related measures are similar to absorbance in their utilization of wide-band stimuli and their focus on recording ear-canal sound pressure. The related measures differ from absorbance in how the ear-canal pressure is analyzed and in the type of information that is extracted from the recorded response. SIL and FPL have both been shown to be better as measures of sound level in the ear canal compared to sound pressure level (SPL) because they reduced calibration errors due to standing waves in studies of behavioral thresholds and otoacoustic emissions. TDR may be used to estimate ear-canal geometry and may have the potential to assess middle-ear pathology. CR reveals information about the inner ear that is similar to what is provided by other types of otoacoustic emissions and may have theoretical advantages that strengthen its interpretation. PMID:23900185

  14. Water-absorbing capacitor system for measuring relative humidity

    NASA Technical Reports Server (NTRS)

    Laue, Eric G. (Inventor)

    1987-01-01

    A method and apparatus using a known water-absorbent polymer as a capacitor which is operated at a dc voltage for measuring relative humidity is presented. When formed as a layer between porous electrically-conductive electrodes and operated in an RC oscillator circuit, the oscillator frequency varies inversely with the partial pressure of the moisture to be measured. In a preferred embodiment, the capacitor is formed from Nafion and is operated at a low dc voltage with a resistor as an RC circuit in an RC oscillator. At the low voltage, the leakage current is proper for oscillation over a satisfactory range. The frequency of oscillation varies in an essentially linear fashion with relative humidity which is represented by the moisture being absorbed into the Nafion. The oscillation frequency is detected by a frequency detector.

  15. New absorbed dose measurement with cylindrical water phantoms for multidetector CT.

    PubMed

    Ohno, Takeshi; Araki, Fujio; Onizuka, Ryota; Hioki, Kazunari; Tomiyama, Yuuki; Yamashita, Yusuke

    2015-06-01

    The aim of this study was to develop new dosimetry with cylindrical water phantoms for multidetector computed tomography (MDCT). The ionization measurement was performed with a Farmer ionization chamber at the center and four peripheral points in the body-type and head-type cylindrical water phantoms. The ionization was converted to the absorbed dose using a (60)Co absorbed-dose-to-water calibration factor and Monte Carlo (MC) -calculated correction factors. The correction factors were calculated from MDCT (Brilliance iCT, 64-slice, Philips Electronics) modeled with GMctdospp (IMPS, Germany) software based on the EGSnrc MC code. The spectrum of incident x-ray beams and the configuration of a bowtie filter for MDCT were determined so that calculated photon intensity attenuation curves for aluminum (Al) and calculated off-center ratio (OCR) profiles in air coincided with those measured. The MC-calculated doses were calibrated by the absorbed dose measured at the center in both cylindrical water phantoms. Calculated doses were compared with measured doses at four peripheral points and the center in the phantom for various beam pitches and beam collimations. The calibration factors and the uncertainty of the absorbed dose determined using this method were also compared with those obtained by CTDIair (CT dose index in air). Calculated Al half-value layers and OCRs in air were within 0.3% and 3% agreement with the measured values, respectively. Calculated doses at four peripheral points and the centers for various beam pitches and beam collimations were within 5% and 2% agreement with measured values, respectively. The MC-calibration factors by our method were 44-50% lower than values by CTDIair due to the overbeaming effect. However, the calibration factors for CTDIair agreed within 5% with those of our method after correction for the overbeaming effect. Our method makes it possible to directly measure the absorbed dose for MDCT and is more robust and accurate than the

  16. New absorbed dose measurement with cylindrical water phantoms for multidetector CT

    NASA Astrophysics Data System (ADS)

    Ohno, Takeshi; Araki, Fujio; Onizuka, Ryota; Hioki, Kazunari; Tomiyama, Yuuki; Yamashita, Yusuke

    2015-06-01

    The aim of this study was to develop new dosimetry with cylindrical water phantoms for multidetector computed tomography (MDCT). The ionization measurement was performed with a Farmer ionization chamber at the center and four peripheral points in the body-type and head-type cylindrical water phantoms. The ionization was converted to the absorbed dose using a 60Co absorbed-dose-to-water calibration factor and Monte Carlo (MC) -calculated correction factors. The correction factors were calculated from MDCT (Brilliance iCT, 64-slice, Philips Electronics) modeled with GMctdospp (IMPS, Germany) software based on the EGSnrc MC code. The spectrum of incident x-ray beams and the configuration of a bowtie filter for MDCT were determined so that calculated photon intensity attenuation curves for aluminum (Al) and calculated off-center ratio (OCR) profiles in air coincided with those measured. The MC-calculated doses were calibrated by the absorbed dose measured at the center in both cylindrical water phantoms. Calculated doses were compared with measured doses at four peripheral points and the center in the phantom for various beam pitches and beam collimations. The calibration factors and the uncertainty of the absorbed dose determined using this method were also compared with those obtained by CTDIair (CT dose index in air). Calculated Al half-value layers and OCRs in air were within 0.3% and 3% agreement with the measured values, respectively. Calculated doses at four peripheral points and the centers for various beam pitches and beam collimations were within 5% and 2% agreement with measured values, respectively. The MC-calibration factors by our method were 44-50% lower than values by CTDIair due to the overbeaming effect. However, the calibration factors for CTDIair agreed within 5% with those of our method after correction for the overbeaming effect. Our method makes it possible to directly measure the absorbed dose for MDCT and is more robust and accurate than the

  17. Performance Measurement to Demonstrate Value.

    PubMed

    Hyder, Joseph A; Hebl, James R

    2015-12-01

    Anesthesiologists are obligated to demonstrate the value of the care they provide. The Centers for Medicare and Medicaid Services has multiple performance-based payment programs to drive high-value care and motivate integrated care for surgical patients and hospitalized patients. These programs rely on diverse arrays of performance measures and complex reporting rules. Among all specialties, anesthesiology has tremendous potential to effect wide-ranging change on diverse measures. Performance measures deserve scrutiny by anesthesiologists as tools to improve care, the means by which payment is determined, and as a means to demonstrate the value of care to surgeons, hospitals, and patients. PMID:26610623

  18. Measurement of EUV absorber and resist CD using spectroscopic ellipsometer

    NASA Astrophysics Data System (ADS)

    Lee, Kyung M.; Tavassoli, Malahat; Yan, Pei-yang; Zhang, Guojing

    2013-09-01

    Evaluation of lithography process or stepper involves very large quantity of CD measurements and measurement time. In this paper, we report on an application of Scatterometry based metrology for evaluation of EUV photomask lithography. Measurements were made on mask level with Ellipsometric scatterometer for develop-check CD (DCCD) and final check CD (FCCD). Calculation of scatterometer profile information was performed with in-situ library-based rigorous coupled wave analysis (RCWA) method. We characterized the CD uniformity (CDU) and metal film thickness uniformity. OCD results show that high precision CD measurement EUV absorber and resist is possible with this method. A series of simulations were also performed to investigate the feasibility of Ellipsometric scatterometry for various pitches/line CD sizes, down to 11nm half-pitch at 1x magnification. The data showed that Scatterometry provides a nondestructive and faster mean of characterizing mask CD performance for various EUV process generations.

  19. Absorbed dose and LET spectra measurements on LDEF

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Csige, I.; Frank, A. L.; Benton, E. R.; Frigo, L. A.; Parnell, T. A.; Watts, J.; Harmon, A.

    1995-01-01

    Total absorbed doses measured with TLD's, linear energy transfer (LET) spectra measured with plastic track detectors, and low energy neutrons measured on LDEF have been compared with model calculations. The total absorbed doses measured in TLD's were higher than predicted in the calculations of Armstrong et al. and differ from the calculations of Atwell et al. LDEF LET spectra are dependent on detector orientation, shielding and experiment location. These factors need to be taken into account when modeling the LDEF LET spectra. LET spectra measured with plastic nuclear track detectors (PNTD's) also deviate significantly from calculations especially for high LET particles (LET(sub infinity) H2O greater than 100keV/micron). Modeling efforts to date do not include the contribution of proton induced secondaries. Analysis of polycarbonate PNTD's from the West-side of LDEF has revealed a very high fluence of tracks (greater than 1 x 10(exp 7) tracks/cm(exp 2) under 2 gm/cm(exp 2) shielding). Fluence drops off rapidly as shielding depth increases. Tracks only form in the region of the detector closest to the surface, not in the bulk of the detector. To date no adequate explanation for this observation has been found. We plan to measure range distribution of very high LET (LET (sub infinity) H2O greater than 500 keV/micron) secondary particles produced in silicon wafer by high energy primary cosmic ray particles. Refinements of experimental techniques and model calculations are being carried out in order to understand existing discrepancies between experimental measurements and calculations.

  20. Strontium-89 therapy: measurement of absorbed dose to skeletal metastases.

    PubMed

    Blake, G M; Zivanovic, M A; Blaquiere, R M; Fine, D R; McEwan, A J; Ackery, D M

    1988-04-01

    We report measurements of absorbed dose to vertebral metastases in ten patients referred for 89Sr therapy for disseminated prostatic carcinoma. Patients received a tracer dose of 85Sr at the time of 89Sr treatment and metastatic strontium retention was monitored scintigraphically for 6 mo. Metastatic 85Sr activity corrected for tissue attenuation was measured using the conjugate view principle, with special care taken to eliminate errors due to the selection of the metastatic region of interest. Metastatic volume was determined from high resolution CT images, and density inferred from Hounsfield number using the QCT bone mineral calibration of Genant and Cann. The mean absorbed dose was 850 rad/mCi (23 cGy/MBq) with a range from 220-2260 rad/mCi (6 to 61 cGy/MBq). The wide range found was consistent with the variation expected to arise due to differences in strontium renal plasma clearance (range 0.1-11.81/day) and extent of skeletal metastatic disease (varying from two small metastases to a superscan on [99mTc]MDP images) among the patients studied. PMID:3351609

  1. Scattering photoacoustic method in measurement of weakly absorbing turbid suspensions

    NASA Astrophysics Data System (ADS)

    Zhao, Zuomin; Törmänen, Matti; Myllylä, Risto

    2006-08-01

    Conventional photoacoustic techniques in composition determination and biomedical diagnose and imaging are based on the optical absorption in target substance or objects from which the photons to be scattered are not concerned. It is obvious that the intensities of scattered lights closely relate to the property of the interrogated substance, therefore measuring the signals produced by them can give rise to more information of the substance. Based on this idea, a novel method entitled scattering photoacoustic (SPA) method is put forward to study weak absorption suspensions with highly scattering. In this method, a near infrared pulse laser irradiates the studied object which contacts with external absorbers, resulting the generation of a few photoacoustic signals; one is produced in the studied object as conventional case, others are in external absorbers which are produced by the scattered photons. All these signals are successively received by a piezoelectric detector with short damping period. Analyzing these signals is capable of determining reduced scattered coefficient and absorption coefficient, as well as acoustic attenuation of studied suspensions. Some measurement results in intralipid and fibre (paper pulp) suspensions are given rise to in the end.

  2. Light Absorbing Particle (LAP) Measurements in the Lower Stratosphere

    NASA Technical Reports Server (NTRS)

    Baumgardner, D.; Raga, G. B.; Anderson, B.; Diskin, G.; Sachse, G.; Kok, G.

    2003-01-01

    This viewgraph presentation covers the capabilities and design of the Single Particle Soot Photometer (SP-2), and reviews its role on the Sage III Ozone Loss Validation Experiment (SOLVE II) field campaign during 2003. On SOLVE II the SP-2 was carried into the Arctic onboard a DC-8 aircraft, in order to determine the size distribution of light-absorbing and non light-absorbing particles in the stratosphere. Graphs and tables relate some of the results from SOLVE II.

  3. Measurement-based estimates of direct radiative effects of absorbing aerosols above clouds

    NASA Astrophysics Data System (ADS)

    Feng, Nan; Christopher, Sundar A.

    2015-07-01

    The elevated layers of absorbing smoke aerosols from western African (e.g., Gabon and Congo) biomass burning activities have been frequently observed above low-level stratocumulus clouds off the African coast, which presents an excellent natural laboratory for studying the effects of aerosols above clouds (AAC) on regional energy balance in tropical and subtropical environments. Using spatially and temporally collocated Moderate Resolution Imaging Spectroradiometer, Ozone Monitoring Instrument (OMI), and Clouds and the Earth's Radiant Energy System data sets, the top-of-atmosphere shortwave aerosol direct shortwave radiative effects (ARE) of absorbing aerosols above low-level water clouds in the southeast Atlantic Ocean was examined in this study. The regional averaged instantaneous ARE has been estimated to be 36.7 ± 20.5 Wm-2 (regional mean ± standard deviation) along with a mean positive OMI Aerosol Index at 1.3 in August 2006 based on multisensors measurements. The highest magnitude of instantaneous ARE can even reach 138.2 Wm-2. We assess that the 660 nm cloud optical depth (COD) values of 8-12 is the critical value above (below) which aerosol absorption (scattering) effect dominates and further produces positive (negative) ARE values. The results further show that ARE values are more sensitive to aerosols above lower COD values than cases for higher COD values. This is among the first studies to provide quantitative estimates of shortwave ARE due to AAC events from an observational perspective.

  4. New procedure for direct measurements of absorbance of thin films of ultra-high absorbance UV blocks

    NASA Astrophysics Data System (ADS)

    McMillan, Norman D.; Solsvik, A.; Murphy, L.; Stevenson, A.; O'Neill, M.; Moore, J.

    2005-06-01

    A novel method for the measurement of ultra-high absorbance liquids has been devised and details are given of a new ultra absorbance instrument developed specifically for these thin liquid film measurements. The instrument specifically constructed for monitoring and measuring sunscreen products has been tested using locally produced sunscreen products. This new approach has been made possible by the development of very accurate liquid micro-dispensers and details are given of the novel procedure to carry out these measurements. Detailed description of the apparatus construction is given with photographs of the apparatus. The work described is largely based on research and quality control measurements of Parasol suncare products. Results on the reproducibility of measurements taken with the UAI for a commercial range of factor 20 sunscreen liquid are given and these have been used to validate the performance of the instrument. It is believed that the absorbance measurements described here are perhaps the largest ever reported. In addition, the photostability of this product has been monitored in aging tests. Finally, some studies have been done on two other commercially available factor 20 products that show that these are significantly worse with regards to both protection from ageing and burn.

  5. Absorbed dose measurements on external surface of Kosmos-satellites with glass thermoluminescent detectors.

    PubMed

    Akatov YuA; Arkhangelsky, V V; Kovalev, E E; Spurny, F; Votochkova, I

    1989-01-01

    In this paper we present absorbed dose measurements with glass thermoluminescent detectors on external surface of satellites of Kosmos-serie flying in 1983-87. Experiments were performed with thermoluminescent aluminophosphate glasses of thicknesses 0.1, 0.3, 0.4, 0.5, and 1 mm. They were exposed in sets of total thickness between 5 and 20 mm, which were protected against sunlight with thin aluminized foils. In all missions, extremely high absorbed dose values were observed in the first layers of detectors, up to the thickness of 0.2 to 0.5 gcm-2. These experimental results confirm that, during flights at 250 to 400 km, doses on the surface of the satellites are very high, due to the low energy component of the proton and electron radiation. PMID:11537297

  6. Fine-Resolution Voxel S Values for Constructing Absorbed Dose Distributions at Variable Voxel Size

    PubMed Central

    Dieudonné, Arnaud; Hobbs, Robert F.; Bolch, Wesley E.; Sgouros, George; Gardin, Isabelle

    2010-01-01

    This article presents a revised voxel S values (VSVs) approach for dosimetry in targeted radiotherapy, allowing dose calculation for any voxel size and shape of a given SPECT or PET dataset. This approach represents an update to the methodology presented in MIRD pamphlet no. 17. Methods VSVs were generated in soft tissue with a fine spatial sampling using the Monte Carlo (MC) code MCNPX for particle emissions of 9 radionuclides: 18F, 90Y, 99mTc, 111In, 123I, 131I, 177Lu, 186Re, and 201Tl. A specific resampling algorithm was developed to compute VSVs for desired voxel dimensions. The dose calculation was performed by convolution via a fast Hartley transform. The fine VSVs were calculated for cubic voxels of 0.5 mm for electrons and 1.0 mm for photons. Validation studies were done for 90Y and 131I VSV sets by comparing the revised VSV approach to direct MC simulations. The first comparison included 20 spheres with different voxel sizes (3.8–7.7 mm) and radii (4–64 voxels) and the second comparison a hepatic tumor with cubic voxels of 3.8 mm. MC simulations were done with MCNPX for both. The third comparison was performed on 2 clinical patients with the 3D-RD (3-Dimensional Radiobiologic Dosimetry) software using the EGSnrc (Electron Gamma Shower National Research Council Canada)-based MC implementation, assuming a homogeneous tissue-density distribution. Results For the sphere model study, the mean relative difference in the average absorbed dose was 0.20% ± 0.41% for 90Y and −0.36% ± 0.51% for 131I (n = 20). For the hepatic tumor, the difference in the average absorbed dose to tumor was 0.33% for 90Y and −0.61% for 131I and the difference in average absorbed dose to the liver was 0.25% for 90Y and −1.35% for 131I. The comparison with the 3D-RD software showed an average voxel-to-voxel dose ratio between 0.991 and 0.996. The calculation time was below 10 s with the VSV approach and 50 and 15 h with 3D-RD for the 2 clinical patients. Conclusion This new

  7. Laser measurement of extinction coefficients of highly absorbing liquids. [airborne oil spill monitoring application

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.; Kincaid, J. S.

    1980-01-01

    A coaxial dual-channel laser system has been developed for the measurement of extinction coefficients of highly absorbing liquids. An empty wedge-shaped sample cell is first translated laterally through a He-Ne laser beam to measure the differential thickness using interference fringes in reflection. The wedge cell is carefully filled with the oil sample and translated through the coaxially positioned dye laser beam for the differential attenuation or extinction measurement. Optional use of the instrumentation as a single-channel extinction measurement system and also as a refractometer is detailed. The system and calibration techniques were applied to the measurement of two crude oils whose extinction values were required to complete the analysis of airborne laser data gathered over four controlled spills.

  8. Technical description of parameters influencing the pH value of suspension absorbent used in flue gas desulfurization systems.

    PubMed

    Głomba, Michał

    2010-08-01

    As a result of the large limestone deposits available in Poland, the low cost of reagent acquisition for the largescale technological use and relatively well-documented processes of flue gas desulfurization (FGD) technologies based on limestone sorbent slurry, wet scrubbing desulfurization is a method of choice in Poland for flue gas treatment in energy production facilities, including power plants and industrial systems. The efficiency of FGD using the above method depends on several technological and kinetic parameters, particularly on the pH value of the sorbent (i.e., ground limestone suspended in water). Consequently, many studies in Poland and abroad address the impact of various parameters on the pH value of the sorbent suspension, such as the average diameter of sorbent particles (related to the limestone pulverization degree), sorbent quality (in terms of pure calcium carbonate [CaCO3] content of the sorbent material), stoichiometric surfeit of CaCO3 in relation to sulfur dioxide (SO2) absorbed from flue gas circulating in the absorption node, time of absorption slurry retention in the absorber tank, chlorine ion concentration in sorbent slurry, and concentration of dissolved metal salts (Na, K, Mg, Fe, Al, and others). This study discusses the results of laboratory-scale tests conducted to establish the effect of the above parameters on the pH value of limestone slurry circulating in the SO2 absorption node. On the basis of the test results, a correlation equation was postulated to help maintain the desirable pH value at the design phase of the wet FGD process. The postulated equation displays good coincidence between calculated pH values and those obtained using laboratory measurements. PMID:20842941

  9. In situ Measurements of Absorbing Aerosols from Urban Sources, in Maritime Environments and during Biomass Combustion

    NASA Astrophysics Data System (ADS)

    Mazzoleni, C.; Manvendra, D.; Chylek, P.; Arnott, P.

    2006-12-01

    Absorbing aerosols have important but still ill quantified effects on climate, visibility, cloud processes, and air quality. The compilation of aerosol scattering and absorption databases from reliable measurements is essential to reduce uncertainties in these inter-linked research areas. The atmospheric radiative balance for example, is modeled using the aerosol single scattering albedo (ratio of scattering to scattering plus absorption, SSA) as a fundamental input parameter in climate models. Sulfate aerosols with SSA values close to 1 scatter solar radiation resulting in a negative radiative forcing. However aerosol SSA values less than 1 are common when combustion processes are contributing to the aerosol sources. Absorbing aerosols directly heat the atmosphere and reduce the solar radiation at the surface. Currently, the net global anthropogenic aerosol direct radiative forcing is estimated to be around -0.5W m-2 with uncertainty of about 80% largely due to lack of understanding of SSA of sulfate-organic-soot aerosols. We present a rapidly expanding data set of direct in situ aerosol absorption and scattering measurements performed since June 2005 by photoacoustic instrument (at 781 and 870 nm), with integrated a total scattering sensor, during numerous field campaigns. Data have been collected over a wide range of aerosol sources, local environments and anthropogenic activities. Airborne measurements were performed in marine stratus off shore of the California coast and in cumulus clouds and clear air in the Houston, TX area; ground-based measurements have been performed in many locations in Mexico City; while laboratory measurements have been collected during a controlled combustion experiment of many different biomass fuels. The large dynamic range of aerosol types and conditions from these different field campaigns will be integrated to help quantify the SSA values, their variability, and their implications on the radiative forcing of climate.

  10. Valuing Learning: The Measurement Journey.

    ERIC Educational Resources Information Center

    Wang, Greg

    2003-01-01

    Discusses the money wasted on ineffective training programs and the resulting surge in interest among training professionals in conducting learning evaluation and return on investment (ROI) measurement. Describes Kirkpatrick's four-level evaluation concept; questions regarding measurement validity and reliability; and new developments in learning…

  11. Performance Measures, Benchmarking and Value.

    ERIC Educational Resources Information Center

    McGregor, Felicity

    This paper discusses performance measurement in university libraries, based on examples from the University of Wollongong (UoW) in Australia. The introduction highlights the integration of information literacy into the curriculum and the outcomes of a 1998 UoW student satisfaction survey. The first section considers performance indicators in…

  12. A Novel, Real-Valued Genetic Algorithm for Optimizing Radar Absorbing Materials

    NASA Technical Reports Server (NTRS)

    Hall, John Michael

    2004-01-01

    A novel, real-valued Genetic Algorithm (GA) was designed and implemented to minimize the reflectivity and/or transmissivity of an arbitrary number of homogeneous, lossy dielectric or magnetic layers of arbitrary thickness positioned at either the center of an infinitely long rectangular waveguide, or adjacent to the perfectly conducting backplate of a semi-infinite, shorted-out rectangular waveguide. Evolutionary processes extract the optimal physioelectric constants falling within specified constraints which minimize reflection and/or transmission over the frequency band of interest. This GA extracted the unphysical dielectric and magnetic constants of three layers of fictitious material placed adjacent to the conducting backplate of a shorted-out waveguide such that the reflectivity of the configuration was 55 dB or less over the entire X-band. Examples of the optimization of realistic multi-layer absorbers are also presented. Although typical Genetic Algorithms require populations of many thousands in order to function properly and obtain correct results, verified correct results were obtained for all test cases using this GA with a population of only four.

  13. Measuring absorbed dose for i-CAT CBCT examinations in child, adolescent and adult phantoms

    PubMed Central

    Choi, E

    2015-01-01

    Objectives: Design and construct child and adolescent head phantoms to measure the absorbed doses imparted during dental CBCT and compare with the absorbed dose measured in an adult phantom. Methods: A child phantom was developed to represent the smallest patients receiving CBCT, usually for craniofacial developmental concerns, and an adolescent phantom was developed to represent healthy orthodontic patients. Absorbed doses were measured using a thimble ionization chamber for the custom-built child and adolescent phantoms and compared with measurements using a commercially available adult phantom. Imaging was performed with an i-CAT Next Generation (Imaging Sciences International, Hatfield, PA) CBCT using two different fields of view covering the craniofacial complex (130 mm high) or maxilla/mandible (60 mm high). Results: Measured absorbed doses varied depending on the location of the ionization chamber within the phantoms. For CBCT images obtained using the same protocol for all phantoms, the highest absorbed dose was measured in all locations of the small child phantom. The lowest absorbed dose was measured in the adult phantom. Conclusions: Images were obtained with the same protocol for the adult, adolescent and child phantoms. A consistent trend was observed with the highest absorbed dose being measured in the smallest phantom (child), while the lowest absorbed dose was measured in the largest phantom (adult). This study demonstrates the importance of child-sizing the dose by using dedicated paediatric protocols optimized for the imaging task, which is critical as children are more sensitive to harmful effects of radiation and have a longer life-span post-irradiation for radiation-induced symptoms to develop than do adults. PMID:25785822

  14. SU-FF-T-390: In-Vivo Prostate Brachytherapy Absorbed Dose Measurements

    SciTech Connect

    Gueye, Paul; Velasco, Carlos; Keppel, Cynthia; Murphy, B; Sinesi, C

    2009-06-01

    Purpose: In-vivo prostate brachytherapy absorbed dosimetrydetector using scintillating fibers. Method and Materials: Five pairs of 85.5 {+-} 0.05 cm long blue shifted scintillating fibers (model BCF-10) with 1 mm{sup 2} cross sectional area were placed in a mixture of gelatin (368.6 {+-} 0.5 grams) and water (3.78 {+-} 0.025 liters) to measured the absorbed dose delivered by a 12 Ci {sup 192}Ir HDR source. The fibers were held by a 7 x 7 cm{sup 2} template grid and optically connected to a 16-channel multianode photomultiplier tube (Hamamatsu, model H6568). Each pair consisted of one fiber 4 mm shorter than the other one to extract the dose by the subtraction method. A dose atlas was used for radiation delivered to the phantom. The plans followed delivered 5 and 7 Gy to a point located 2.0 centimeters away from the central dwelling positions. A total of 32 data points were acquired in a plan to assess the linearity and reproducibility of the measurements.Results: Reproducibility of the data was found to be within 5% and the overall accuracy of the system estimated to be {+-}5.5%. The linearity of the data for all 7 measureddose values (ranging from 0.6 to 7 Gy), gives a slope of 312 counts/Gy with a 1.4% relative deviation. Conclusion: This work indicates the possibility of measuring in real-time the dose effectively delivered to a biological system during prostate brachytherapy treatments. The availability of commercially thin (150 {micro}m) scintillating fibers opens the capability of using such system during clinical treatments (by embedding the fibers within the catheters) with the advantage of performing real-time adjustment of the dose delivery.

  15. MEASURING LOW-VALUE CARE IN MEDICARE

    PubMed Central

    Schwartz, Aaron L.; Landon, Bruce E.; Elshaug, Adam G.; Chernew, Michael E.; McWilliams, J. Michael

    2014-01-01

    Importance Despite the importance of identifying and reducing wasteful health care utilization, few direct measures of overuse have been developed. Direct measures are appealing because they identify specific services to limit and can characterize low-value care even among the most efficient providers. Objective To develop claims-based measures of low-value services, examine service use (and associated spending) detected by these measures in Medicare, and determine if patterns of use are related across different types of low-value services. Design, Setting and Participants Drawing from evidence-based lists of services that provide minimal clinical benefit, we developed and trialed 26 claims-based measures of low-value services. Using 2009 claims for 1,360,908 Medicare beneficiaries, we assessed the proportion of beneficiaries receiving these services, mean per-beneficiary service use, and the proportion of total spending devoted to these services. We compared the amount of use and spending detected by versions of these measures with different sensitivity and specificity. We also estimated correlations between use of different services within geographic areas, adjusting for beneficiaries’ sociodemographic and clinical characteristics. Main Outcome Measures Use and spending detected by 26 measures of low-value services in 6 categories: low-value cancer screening; low-value diagnostic and preventive testing; low-value preoperative testing; low-value imaging; low-value cardiovascular testing and procedures; and other low-value surgical procedures. Results Services detected by more sensitive versions of measures affected 41% of beneficiaries and constituted 2.7% of overall annual spending. Services detected by more specific versions of measures affected 24% of beneficiaries and constituted 0.6% of overall spending. In adjusted analyses, low-value spending detected in geographic regions at the 5th percentile of the regional distribution of low-value spending ($221

  16. Density measurement in air with saturable absorbing seed gas

    NASA Technical Reports Server (NTRS)

    Baganoff, D.

    1982-01-01

    Approaches which have the potential to make density measurements in a compressible flow, where one or more laser beams are used as probes, were investigated. Saturation in sulfur hexafluoride iodine and a crossed beam technique where one beam acts as a saturating beam and the other is at low intensity and acts as a probe beam are considered. It is shown that a balance between an increase in fluorescence intensity with increasing pressure from line broadening and the normal decrease in intensity with increasing pressure from quenching can be used to develop a linear relation between fluorescence intensity and number density and lead to a new density measurement scheme. The method is used to obtain a density image of the cross section of an iodine seeded underexpanded supersonic jet of nitrogen, by illuminating the cross section by a sheet of laser light.

  17. Density measurement in air with a saturable absorbing seed gas

    NASA Technical Reports Server (NTRS)

    Baganoff, D.

    1981-01-01

    Resonantly enhanced scattering from the iodine molecule is studied experimentally for the purpose of developing a scheme for the measurement of density in a gas dynamic flow. A study of the spectrum of iodine, the collection of saturation data in iodine, and the development of a mathematical model for correlating saturation effects were pursued for a mixture of 0.3 torr iodine in nitrogen and for mixture pressures up to one atmosphere. For the desired pressure range, saturation effects in iodine were found to be too small to be useful in allowing density measurements to be made. The effects of quenching can be reduced by detuning the exciting laser wavelength from the absorption line center of the iodine line used (resonant Raman scattering). The signal was found to be nearly independent of pressure, for pressures up to one atmosphere, when the excitation beam was detuned 6 GHz from line center for an isolated line in iodine. The signal amplitude was found to be nearly equal to the amplitude for fluorescence at atmospheric pressure, which indicates a density measurement scheme is possible.

  18. Monte Carlo simulation for the prediction of precision of absorbance measurements with a miniature CCD spectrometer.

    PubMed

    Tsaousoglou, E P; Bolis, S D; Efstathiou, C E

    2003-01-01

    The precision characteristics of the absorbance measurements obtained with a low-cost miniature spectrometer incorporating an array detector were evaluated. Uncertainties in absorbance measurements were due to a combination of non-uniform light intensity and detector response over the wavelength range examined (350-850 nm), in conjunction with the digitization of the intensity indications and the intrinsic noise of the detecting elements. The precision characteristics are presented as contour plots displaying the expected RSD% of absorbances on the absorbance versus wavelength plane. The minimum RSD% for the spectrometer configuration tested was observed within the 0.2-1.5 absorbance units and 500-750 nm wavelength range. Without invoking signal enhancement features of the data-acquisition program (scan average, higher integration times, smoothing based on averaging the signal detected by adjacent pixels), the attainable precision within this range was 0.4-0.8%. A computer program based on Monte Carlo simulations was developed for the prediction of absorbance precision characteristics under various conditions of measurements. PMID:18924714

  19. Density measurement in air with a saturable absorbing seed gas

    NASA Technical Reports Server (NTRS)

    Baganoff, D.

    1982-01-01

    A method for making density measurements in a compressible flow by using off resonance laser induced fluorescence is studied. The seed molecule chosen for study is the iodine molecule which is excited with the 514.5 nm line of the argon ion laser whose output is frequency tuned, by as much as 3 GHz, relative to a strong iodine transition using an intracavity etalon. The theory which was developed to analyze the effect will be used in conjunction with two experiments being conducted to further study the method an acoustic resonance tube in which controlled perturbations about a uniform state are produced, and a small supersonic jet in which the conditions of the flow vary widely from point to point.

  20. Dual photonic-electrochemical lab on a chip for online simultaneous absorbance and amperometric measurements.

    PubMed

    Ordeig, Olga; Ortiz, Pedro; Muñoz-Berbel, Xavier; Demming, Stefanie; Büttgenbach, Stephanus; Fernández-Sánchez, César; Llobera, Andreu

    2012-04-17

    A dual lab on a chip (DLOC) approach that enables simultaneous optical and electrochemical detection working in a continuous flow regime is presented. Both detection modes are integrated for the first time into a single detection volume and operate simultaneously with no evidence of cross-talk. The electrochemical cell was characterized amperometrically by measuring the current in ferrocyanide solutions at +0.4 V vs gold pseudoreference electrode, at a flow rate of 200 μL min(-1). The experimental results for ferrocyanide concentrations ranging from 0.005 to 2 mM were in good agreement with the values predicted by the Levich equation for a microelectrode inside a rectangular channel, with a sensitivity of 2.059 ± 0.004 μA mM(-1) and a limit of detection (LoD) of (2.303 ± 0.004) × 10(-3) mM. Besides, optical detection was evaluated by measuring the absorbance of ferricyanide solutions at 420 nm. The results obtained therein coincide with those predicted by the Beer-Lambert law for a range of ferricyanide concentrations from 0.005 to 0.3 mM and showed an estimated LoD of (0.553 ± 0.001) × 10(-3) mM. The DLOC was finally applied to the analysis of L-lactate via a bienzymatic reaction involving lactate oxidase (LOX) and horseradish peroxidase (HRP). Here, the consumption of the reagent of the reaction (ferrocyanide) was continuously monitored by amperometry whereas the product of the reaction (ferricyanide) was recorded by absorbance. The DLOC presented good performance in terms of sensitivity and limit of detection, comparable to other fluidic systems found in the literature. Additionally, the ability to simultaneously quantify enzymatic reagent consumption and product generation confers the DLOC a self-verifying capability which in turn enhances its robustness and reliability. PMID:22429156

  1. Analysis and measurement of electromagnetic scattering by pyramidal and wedge absorbers

    NASA Technical Reports Server (NTRS)

    Dewitt, B. T.; Burnside, Walter D.

    1986-01-01

    By modifying the reflection coefficients in the Uniform Geometrical Theory of Diffraction a solution that approximates the scattering from a dielectric wedge is found. This solution agrees closely with the exact solution of Rawlins which is only valid for a few minor cases. This modification is then applied to the corner diffraction coefficient and combined with an equivalent current and geometrical optics solutions to model scattering from pyramid and wedge absorbers. Measured results from 12 inch pyramid absorbers from 2 to 18 GHz are compared to calculations assuming the returns add incoherently and assuming the returns add coherently. The measured results tend to be between the two curves. Measured results from the 8 inch wedge absorber are also compared to calculations with the return being dominated by the wedge diffraction. The procedures for measuring and specifying absorber performance are discussed and calibration equations are derived to calculate a reflection coefficient or a reflectivity using a reference sphere. Shaping changes to the present absorber designs are introduced to improve performance based on both high and low frequency analysis. Some prototypes were built and tested.

  2. Absorbed dose measurements in the build-up region of flattened versus unflattened megavoltage photon beams.

    PubMed

    De Puysseleyr, Annemieke; Lechner, Wolfgang; De Neve, Wilfried; Georg, Dietmar; De Wagter, Carlos

    2016-06-01

    This study evaluated absorbed dose measurements in the build-up region of conventional (FF) versus flattening filter-free (FFF) photon beams. The absorbed dose in the build-up region of static 6 and 10MV FF and FFF beams was measured using radiochromic film and extrapolation chamber dosimetry for single beams with a variety of field sizes, shapes and positions relative to the central axis. Removing the flattening filter generally resulted in slightly higher relative build-up doses. No considerable impact on the depth of maximum dose was found. PMID:27020966

  3. Absorbed dose measurements for kV-cone beam computed tomography in image-guided radiation therapy.

    PubMed

    Hioki, Kazunari; Araki, Fujio; Ohno, Takeshi; Nakaguchi, Yuji; Tomiyama, Yuuki

    2014-12-01

    In this study, we develope a novel method to directly evaluate an absorbed dose-to-water for kilovoltage-cone beam computed tomography (kV-CBCT) in image-guided radiation therapy (IGRT). Absorbed doses for the kV-CBCT systems of the Varian On-Board Imager (OBI) and the Elekta X-ray Volumetric Imager (XVI) were measured by a Farmer ionization chamber with a (60)Co calibration factor. The chamber measurements were performed at the center and four peripheral points in body-type (30 cm diameter and 51 cm length) and head-type (16 cm diameter and 33 cm length) cylindrical water phantoms. The measured ionization was converted to the absorbed dose-to-water by using a (60)Co calibration factor and a Monte Carlo (MC)-calculated beam quality conversion factor, kQ, for (60)Co to kV-CBCT. The irradiation for OBI and XVI was performed with pelvis and head modes for the body- and the head-type phantoms, respectively. In addition, the dose distributions in the phantom for both kV-CBCT systems were calculated with MC method and were compared with measured values. The MC-calculated doses were calibrated at the center in the water phantom and compared with measured doses at four peripheral points. The measured absorbed doses at the center in the body-type phantom were 1.96 cGy for OBI and 0.83 cGy for XVI. The peripheral doses were 2.36-2.90 cGy for OBI and 0.83-1.06 cGy for XVI. The doses for XVI were lower up to approximately one-third of those for OBI. Similarly, the measured doses at the center in the head-type phantom were 0.48 cGy for OBI and 0.21 cGy for XVI. The peripheral doses were 0.26-0.66 cGy for OBI and 0.16-0.30 cGy for XVI. The calculated peripheral doses agreed within 3% in the pelvis mode and within 4% in the head mode with measured doses for both kV-CBCT systems. In addition, the absorbed dose determined in this study was approximately 4% lower than that in TG-61 but the absorbed dose by both methods was in agreement within their combined uncertainty. This method

  4. Study of the automatic measuring technique and instrument for an automobile shock-absorber connecting rod

    NASA Astrophysics Data System (ADS)

    Chen, Chan-Yao; Dai, Shuguang; Zhang, R. J.; Mu, Ping-An

    1993-09-01

    The autinobile shock absorber connecting rod makes very strict tolerance requirements on the diameter size, roundness, straightness. Because it is a kind of thin and long workpiece, it is difficult to measure the errors of the roundness and axis straightness. Furthermore, it brings much difficulty to realize the highly efficient autinatic measurment as the connecting rod is mass produced. Therefore, there is not any kind of connecting rod automatic measuring instrument available in China. In this article, the authors put forword the methods and principles which can autiatically and efficiently measure the above-mentioned errors of the connecting rod and have designed a reliable and simple automatic measuring instrument, Furthermore, the designing requirements and methods of the software and the electrical system are also introduced. The problem of the automatic measurement of the automobile shock absorber connecting rod has been solved. and it not only guarantees the quality of the rod, but also provides the basis for technical analysis of the product.

  5. Effects of Consecutive Wideband Tympanometry Trials on Energy Absorbance Measures of the Middle Ear

    ERIC Educational Resources Information Center

    Burdiek, Laina M.; Sun, Xiao-Ming

    2014-01-01

    Purpose: Wideband acoustic immittance (WAI) is a new technique for assessing middle ear transfer function. It includes energy absorbance (EA) measures and can be acquired with the ear canal pressure varied, known as "wideband tympanometry" (WBTymp). The authors of this study aimed to investigate effects of consecutive WBTymp testing on…

  6. Estimation of bermudagrass forage intake from canopy spectral absorbance measurements using hyperspectral radiometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hyperspectral forage canopy absorbance was estimated on eight random plots in each of three 1.2 ha common bermudagrass pastures weekly over a period of 9 weeks from June through early August, 2005 using spectroradiometers measuring light reflectance from 410 nm to 1010 nm. Forage in each plot was ...

  7. Increasing dust-absorbing equipment operation efficiency using the automatic laser instrument for solid particle concentration measurement

    NASA Astrophysics Data System (ADS)

    Privalov, Vadim V.; Shemanin, Valery G.; Charty, Pavel V.

    2003-06-01

    The technological process of cement production, which side effect is dust generating and its exhausting to atmosphere, is not stopped as a rule when some faults were origin in dust-absorbing equipment (DAE). The analysis in reference one shows that longtime conducting of the technological process at DAE refusal or fault leads to its working efficiency reduction, which reveals itself in significant excess of nominal values of the dust output concentrations. The number of the most typical refusals and damages and algorithms of their searching were analyzed in work in reference 2 for the most wide-spread dust-absorber types: blanch and electrostatic filters. This work goal are the estimation of DAE working efficiency and choosing of the optimum way of its increasing with using of the automatic laser instrument for aerosol particles concentration measuring in the dust-air flows.

  8. Determining the Absorbance Spectra of Photochromic Materials From Measured Spectrophotometer Data

    NASA Technical Reports Server (NTRS)

    Downie, John D.

    1998-01-01

    If a two-state photochromic material is optically bleached, the absorbance spectrum data measured by a spectrophotometer is in general comprised of components from both the ground state and the upper state. Under general conditions, it may be difficult to extract the actual upper state spectrum from the spectrum of the bleached material. A simple algorithm is presented here for the recovery of the pure absorbance spectra of the upper state of a material such as bacteriorhodopsin, given single wavelength bleaching illumination, steady-state conditions, and accurate knowledge of phototransition rates and thermal decay rates.

  9. Measurement of Raman spectra of single airborne absorbing particles trapped by a single laser beam.

    PubMed

    Ling, Lin; Li, Yong-qing

    2013-02-15

    We demonstrate a method for optical trapping and Raman spectroscopy of micron-sized, airborne absorbing particles using a single focused laser beam. A single Gaussian beam at 532 nm is used to trap and precisely manipulate absorbing airborne particles. The fluctuation of the position of the trapped particles is substantially reduced by controlling the power of the laser beam with a position-sensitive detector and a locking circuit. Raman spectra of the position-stabilized particles or clusters are then measured with an objective and CCD spectrograph. PMID:23455087

  10. Sensitive absorbance measurement method based on laser multi-wave mixing

    NASA Astrophysics Data System (ADS)

    Wu, Zhiqiang; Liu, Jinying; Tong, william G.

    1994-12-01

    A sensitive absorbance measurement based on nonlinear laser degenerate four-wave mixing is demonstrated for cadmium. The cadmium ions react with dithizone to form a cadium complex which is then extracted in carbon tetrachloride and analyzed. A relatively low-power argon ion laser line at 514.5 nm is used as the excitation light source. This nonlinear laser method offers many useful features including efficient and simple optical signal detection (signal is a collimated coherent beam), excellent detection sensitivity for absorbance, and efficient use of low laser power levels, small laser probe volumes and short analyte path legnths (e.g., <0.5 mm). A detection limit of 7 fg or 0.05 ng/ml for cadmium, corresponding to an absorbance detection limit of 1.8 × 10 -6 AU is reported using a flowing analyte cell at room temperature.

  11. In situ measurements of the oblique incidence sound absorption coefficient for finite sized absorbers.

    PubMed

    Ottink, Marco; Brunskog, Jonas; Jeong, Cheol-Ho; Fernandez-Grande, Efren; Trojgaard, Per; Tiana-Roig, Elisabet

    2016-01-01

    Absorption coefficients are mostly measured in reverberation rooms or with impedance tubes. Since these methods are only suitable for measuring the random incidence and the normal incidence absorption coefficient, there exists an increasing need for absorption coefficient measurement of finite absorbers at oblique incidence in situ. Due to the edge diffraction effect, oblique incidence methods considering an infinite sample fail to measure the absorption coefficient at large incidence angles of finite samples. This paper aims for the development of a measurement method that accounts for the finiteness of the absorber. A sound field model, which accounts for scattering from the finite absorber edges, assuming plane wave incidence is derived. A significant influence of the finiteness on the radiation impedance and the corresponding absorption coefficient is found. A finite surface method, which combines microphone array measurements over a finite sample with the sound field model in an inverse manner, is proposed. Besides, a temporal subtraction method, a microphone array method, impedance tube measurements, and an equivalent fluid model are used for validation. The finite surface method gives promising agreement with theory, especially at near grazing incidence. Thus, the finite surface method is proposed for further measurements at large incidence angles. PMID:26827003

  12. High-precision measurements of light-induced torque on absorbing microspheres

    NASA Astrophysics Data System (ADS)

    Capitanio, Marco; Normanno, Davide; Saverio Pavone, Francesco

    2004-10-01

    Laser beams have been demonstrated to be capable of exerting torque as well as forces on microparticles. Using a custom magneto-optic manipulator, we directly measured the torque exerted by laser light on absorbing microspheres as a result of the transfer of spin angular momentum. A general method for measuring torque has been developed, and the experimental apparatus has shown a sensitivity of ~1 pN/nm.

  13. One Moon, many measurements 1: Radiance values

    NASA Astrophysics Data System (ADS)

    Pieters, C. M.; Boardman, J. W.; Ohtake, M.; Matsunaga, T.; Haruyama, J.; Green, R. O.; Mall, U.; Staid, M. I.; Isaacson, P. J.; Yokota, Y.; Yamamoto, S.; Besse, S.; Sunshine, J. M.

    2013-09-01

    Several modern optical instruments orbited the Moon during 2008 and 2009 onboard the SELENE and Chandrayaan-1 spacecraft and provided a welcomed feast of spectroscopic data to be used for scientific analyses. The different spatial and spectral resolutions of these sensors along with diverse illumination geometry during data acquisition make each set of data unique, and each instrument contributes special value to integrated science analyses. In order to provide the maximum science benefit, we have undertaken a careful cross-validation of radiance data among these orbital instruments and also a set of systematic data acquired using Earth-based telescopes. Most radiance values at 750 nm fall between 0 and 100 W/(m2 μm sr), but a small important fraction can be up to ×2 to ×3 that value, with the largest values occurring at the highest spatial resolution. All instruments are in agreement about overall spectral properties of lunar materials, but small systematic differences are documented between instruments. Lunar radiance values measured with remote sensors for landing sites are all not as high as that estimated from laboratory measurements of returned soil. This is largely because laboratory measurements of lunar soils cannot retain or duplicate the fine structure of lunar regolith found in the natural space environment.

  14. Localization of an absorber in a turbid semi-infinite medium by spatially resolved continuous-wave diffuse reflectance measurements

    NASA Astrophysics Data System (ADS)

    Aksel, Ertugrul Burtecin; Turkoglu, Ahu Nur; Ercan, Ayse Ece; Akin, Ata

    2011-08-01

    A method to locate an absorber embedded in a semi-infinite turbid medium by spatially-resolved continuous-wave (SRCW) diffuse reflectance measurements is introduced. The depth of the absorber is assessed by single wavelength SRCW diffuse reflectance measurements by two detectors in a radial row. The ratio of perturbations introduced by the defect at two detectors is used to be matched with the ratio-versus-depth curve, which are generated by approximate formulas of continuous wave diffuse reflectance. The error due to approximation and the error in depth assessment are studied for different cases revealing favorable source-detector placements with respect to planar position of the defect. The effect of lateral displacement of the source with respect to defect is studied. A strategy to overcome errors introduced by erroneous prediction of background medium optical properties is suggested. Theoretical results indicate that the depth of the absorber can be obtained with 0.1 mm precision independent of its absorption coefficient and its size for the values chosen in the study. The approach is tested experimentally and it is observed that theoretical results fit with experimental data.

  15. CAN CONTINGENT VALUATION MEASURE PASSIVE USE VALUES

    EPA Science Inventory

    Contingent valuation (CV) is the only method currently available for practically measuring passive-use values. Because proposed laws may require that environmental regulations pass a benefit-cost test, CV has become central to the policy debate on environmental protection. Crit...

  16. Measuring radiology's value in time saved.

    PubMed

    Lee, Christoph I; Enzmann, Dieter R

    2012-10-01

    Because radiology has historically not measured its added value to patient care and thus not communicated it in easily understood terms to all stakeholders, the specialty must correct this to prepare for the eventual transition from the current fee-for-service payment schedule to new value-based reimbursement systems. Given the increasing risk for marginalization, radiologists need to engage clinicians and managers to map the processes and associated costs of episodes of patient care to identify areas for providing and improving integrated diagnostic information and to measure the value thereof. In such time-driven, activity-based costing practices, radiologists should highlight how proper investments in the information generated by imaging and how radiologists' associated consultative and coordination of services can save greater resources downstream, especially in the nonrenewable resource of physician time, an increasingly scarce health care resource. Using physician time in the most efficient way will be a key element for decreasing health care costs at the aggregate level. Therefore, expressing radiology's contribution in terms of downstream physician time saved is a metric that can be easily understood by all stakeholders. In a conceptual framework centered on value, the specialty of radiology must focus more on its most important product, actionable information, rather than on imaging technologies themselves. Information, unlike imaging technologies, does not depreciate with time but rather increases in value the more it is used. PMID:23025865

  17. Optical absorbance measurements and photoacoustic evaluation of freeze-thawed polyvinyl-alcohol vessel phantoms

    NASA Astrophysics Data System (ADS)

    Arabul, M. U.; Heres, H. M.; Rutten, M.; van de Vosse, F.; Lopata, R.

    2015-03-01

    Multispectral photoacoustic (MPA) imaging is a promising tool for the diagnosis of atherosclerotic carotids. Excitation of different constituents of a plaque with different wavelengths of the light may provide morphological information to evaluate plaque vulnerability. Preclinical validation of in vivo photoacoustic (PA) imaging requires a comprehensive phantom study. In this study, the design of optically realistic vessel phantoms for photoacoustics was examined by characterizing their optical properties for different dye concentrations, and comparing those to PA measurements. Four different concentrations of Indian ink and molecular dye were added to a 15 wt% PVA and 1 wt% orgasol mixture. Next, the homogeneously mixed gels were subjected to five freeze - thaw cycles to increase the stiffness of vessel phantoms (rinner = 2:5mm, router = 4mm). For each cycle, the optical absorbance was measured between 400 nm 990 nm using a plate reader. Additionally, photoacoustic responses of each vessel phantom at 808 nm were tested with a novel, hand-held, integrated PA probe. Measurements show that the PA signal intensity increases with the optical absorber concentration (0.3 to 0.9) in close agreement with the absorbance measurements. The freeze - thaw process has no significant effect on PA intensity. However, the total attenuation of optical energy increases after each freeze-thaw cycle, which is primarily due to the increase in the scattering coefficient. In future work, the complexity of these phantoms will be increased to examine the feasibility of distinguishing different constituents with MPA imaging.

  18. Valuing vaccines using value of statistical life measures.

    PubMed

    Laxminarayan, Ramanan; Jamison, Dean T; Krupnick, Alan J; Norheim, Ole F

    2014-09-01

    Vaccines are effective tools to improve human health, but resources to pursue all vaccine-related investments are lacking. Benefit-cost and cost-effectiveness analysis are the two major methodological approaches used to assess the impact, efficiency, and distributional consequences of disease interventions, including those related to vaccinations. Childhood vaccinations can have important non-health consequences for productivity and economic well-being through multiple channels, including school attendance, physical growth, and cognitive ability. Benefit-cost analysis would capture such non-health benefits; cost-effectiveness analysis does not. Standard cost-effectiveness analysis may grossly underestimate the benefits of vaccines. A specific willingness-to-pay measure is based on the notion of the value of a statistical life (VSL), derived from trade-offs people are willing to make between fatality risk and wealth. Such methods have been used widely in the environmental and health literature to capture the broader economic benefits of improving health, but reservations remain about their acceptability. These reservations remain mainly because the methods may reflect ability to pay, and hence be discriminatory against the poor. However, willingness-to-pay methods can be made sensitive to income distribution by using appropriate income-sensitive distributional weights. Here, we describe the pros and cons of these methods and how they compare against standard cost-effectiveness analysis using pure health metrics, such as quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs), in the context of vaccine priorities. We conclude that if appropriately used, willingness-to-pay methods will not discriminate against the poor, and they can capture important non-health benefits such as financial risk protection, productivity gains, and economic wellbeing. PMID:25045822

  19. Atomic Calculations and Laboratory Measurements Relevant to X-ray Warm Absorbers

    NASA Technical Reports Server (NTRS)

    Kallman, Tim; Bautista, M.; Palmeri, P.

    2007-01-01

    This viewgraph document reviews the atomic calculations and the measurements from the laboratory that are relevant to our understanding of X-Ray Warm Absorbers. Included is a brief discussion of the theoretical and the experimental tools. Also included is a discussion of the challenges, and calculations relevant to dielectronic recombination, photoionization cross sections, and collisional ionization. A review of the models is included, and the sequence that the models were applied.

  20. Measurement of absorbed dose rate of gamma radiation for lead compounds

    NASA Astrophysics Data System (ADS)

    Rudraswamy, B.; Dhananjaya, N.; Manjunatha, H. C.

    2010-07-01

    An attempt has been made to estimate the absorbed dose rate using both theoretical and measured mass energy attenuation coefficient of gamma for the lead compounds such as PbNO 3, PbCl 2, PbO 2 and PbO using various gamma sources such as 22Na (511, 1274), 137Cs (661.6), 54Mn (835) and 60Co (1173, 1332 keV).

  1. Microdosimetric measurements for neutron-absorbed dose determination during proton therapy

    PubMed Central

    Pérez-Andújar, Angélica; DeLuca, Paul M.; Thornton, Allan F.; Fitzek, Markus; Hecksel, Draik; Farr, Jonathan

    2012-01-01

    This work presents microdosimetric measurements performed at the Midwest Proton Radiotherapy Institute in Bloomington, Indiana, USA. The measurements were done simulating clinical setups with a water phantom and for a variety of stopping targets. The water phantom was irradiated by a proton spread out Bragg peak (SOBP) and by a proton pencil beam. Stopping target measurements were performed only for the pencil beam. The targets used were made of polyethylene, brass and lead. The objective of this work was to determine the neutron-absorbed dose for a passive and active proton therapy delivery, and for the interactions of the proton beam with materials typically in the beam line of a proton therapy treatment nozzle. Neutron doses were found to be higher at 45° and 90° from the beam direction for the SOBP configuration by a factor of 1.1 and 1.3, respectively, compared with the pencil beam. Meanwhile, the pencil beam configuration produced neutron-absorbed doses 2.2 times higher at 0° than the SOBP. For stopping targets, lead was found to dominate the neutron-absorbed dose for most angles due to a large production of low-energy neutrons emitted isotropically. PMID:22334761

  2. An international dosimetry exchange for boron neutron capture therapy, Part I: Absorbed dose measurements

    SciTech Connect

    Binns, P.J.; Riley, K.J.; Harling, O.K.

    2005-12-15

    An international collaboration was organized to undertake a dosimetry exchange to enable the future combination of clinical data from different centers conducting neutron capture therapy trials. As a first step (Part I) the dosimetry group from the Americas, represented by MIT, visited the clinical centers at Studsvik (Sweden), VTT Espoo (Finland), and the Nuclear Research Institute (NRI) at Rez (Czech Republic). A combined VTT/NRI group reciprocated with a visit to MIT. Each participant performed a series of dosimetry measurements under equivalent irradiation conditions using methods appropriate to their clinical protocols. This entailed in-air measurements and dose versus depth measurements in a large water phantom. Thermal neutron flux as well as fast neutron and photon absorbed dose rates were measured. Satisfactory agreement in determining absorbed dose within the experimental uncertainties was obtained between the different groups although the measurement uncertainties are large, ranging between 3% and 30% depending upon the dose component and the depth of measurement. To improve the precision in the specification of absorbed dose amongst the participants, the individually measured dose components were normalized to the results from a single method. Assuming a boron concentration of 15 {mu}g g{sup -1} that is typical of concentrations realized clinically with the boron delivery compound boronophenylalanine-fructose, systematic discrepancies in the specification of the total biologically weighted dose of up to 10% were apparent between the different groups. The results from these measurements will be used in future to normalize treatment plan calculations between the different clinical dosimetry protocols as Part II of this study.

  3. An international dosimetry exchange for boron neutron capture therapy. Part I: Absorbed dose measurements.

    PubMed

    Binns, P J; Riley, K J; Harling, O K; Kiger, W S; Munck af Rosenschöld, P M; Giusti, V; Capala, J; Sköld, K; Auterinen, I; Serén, T; Kotiluoto, P; Uusi-Simola, J; Marek, M; Viererbl, L; Spurny, F

    2005-12-01

    An international collaboration was organized to undertake a dosimetry exchange to enable the future combination of clinical data from different centers conducting neutron capture therapy trials. As a first step (Part I) the dosimetry group from the Americas, represented by MIT, visited the clinical centers at Studsvik (Sweden), VTT Espoo (Finland), and the Nuclear Research Institute (NRI) at Rez (Czech Republic). A combined VTT/NRI group reciprocated with a visit to MIT. Each participant performed a series of dosimetry measurements under equivalent irradiation conditions using methods appropriate to their clinical protocols. This entailed in-air measurements and dose versus depth measurements in a large water phantom. Thermal neutron flux as well as fast neutron and photon absorbed dose rates were measured. Satisfactory agreement in determining absorbed dose within the experimental uncertainties was obtained between the different groups although the measurement uncertainties are large, ranging between 3% and 30% depending upon the dose component and the depth of measurement. To improve the precision in the specification of absorbed dose amongst the participants, the individually measured dose components were normalized to the results from a single method. Assuming a boron concentration of 15 microg g(-1) that is typical of concentrations realized clinically with the boron delivery compound boronophenylalanine-fructose, systematic discrepancies in the specification of the total biologically weighted dose of up to 10% were apparent between the different groups. The results from these measurements will be used in future to normalize treatment plan calculations between the different clinical dosimetry protocols as Part II of this study. PMID:16475772

  4. Diamond detector in absorbed dose measurements in high-energy linear accelerator photon and electron beams.

    PubMed

    Ravichandran, Ramamoorthy; Binukumar, John Pichy; Al Amri, Iqbal; Davis, Cheriyathmanjiyil Antony

    2016-01-01

    Diamond detectors (DD) are preferred in small field dosimetry of radiation beams because of small dose profile penumbras, better spatial resolution, and tissue-equivalent properties. We investigated a commercially available 'microdiamond' detector in realizing absorbed dose from first principles. A microdiamond detector, type TM 60019 with tandem electrometer is used to measure absorbed doses in water, nylon, and PMMA phantoms. With sensitive volume 0.004 mm3, radius 1.1mm, thickness 1 x10(-3) mm, the nominal response is 1 nC/Gy. It is assumed that the diamond detector could collect total electric charge (nC) developed during irradiation at 0 V bias. We found that dose rate effect is less than 0.7% for changing dose rate by 500 MU/min. The reproducibility in obtaining readings with diamond detector is found to be ± 0.17% (1 SD) (n = 11). The measured absorbed doses for 6 MV and 15 MV photons arrived at using mass energy absorption coefficients and stop-ping power ratios compared well with Nd, water calibrated ion chamber measured absorbed doses within 3% in water, PMMA, and nylon media. The calibration factor obtained for diamond detector confirmed response variation is due to sensitivity due to difference in manufacturing process. For electron beams, we had to apply ratio of electron densities of water to carbon. Our results qualify diamond dosimeter as a transfer standard, based on long-term stability and reproducibility. Based on micro-dimensions, we recommend these detectors for pretreatment dose verifications in small field irradiations like stereotactic treatments with image guidance. PMID:27074452

  5. Measurements of the light-absorbing material inside cloud droplets and its effect on cloud albedo

    NASA Technical Reports Server (NTRS)

    Twohy, C. H.; Clarke, A. D.; Warren, Stephen G.; Radke, L. F.; Charleson, R. J.

    1990-01-01

    Most of the measurements of light-absorbing aerosol particles made previously have been in non-cloudy air and therefore provide no insight into aerosol effects on cloud properties. Here, researchers describe an experiment designed to measure light absorption exclusively due to substances inside cloud droplets, compare the results to related light absorption measurements, and evaluate possible effects on the albedo of clouds. The results of this study validate those of Twomey and Cocks and show that the measured levels of light-absorbing material are negligible for the radiative properties of realistic clouds. For the measured clouds, which appear to have been moderately polluted, the amount of elemental carbon (EC) present was insufficient to affect albedo. Much higher contaminant levels or much larger droplets than those measured would be necessary to significantly alter the radiative properties. The effect of the concentrations of EC actually measured on the albedo of snow, however, would be much more pronounced since, in contrast to clouds, snowpacks are usually optically semi-infinite and have large particle sizes.

  6. The effects of optical scattering on pulsed photoacoustic measurement in weakly absorbing liquids

    NASA Astrophysics Data System (ADS)

    Zhao, Zuomin; Myllylä, Risto

    2001-12-01

    In this article, a photoacoustic technique, excited by a pulsed diode laser, is used in a study of optically absorbing and scattering liquids. The article discusses the effects of optical scattering on the photoacoustic source and signal. In the empirical part, varying amounts of milk and carbon powder were added to water to control the absorption and scattering coefficients of the resulting liquids. The results showed that scattering increases the duration of the photoacoustic signal while decreasing the signal amplitude to some degree. This paper also shows a quite simple method for measuring the scattering coefficient in weakly absorbing materials using a PZT transducer, which can be used to determine the concentration of highly scattering compositions in some cases.

  7. Environmental audits -- Defining measurable value and benefits

    SciTech Connect

    Murphy, P.

    1998-07-01

    It is well accepted that historically traditional find and fix environmental audits are at best, short-term solutions. Such reactive thinking does not effectively identify the cause(s), are often short-lived and when facilities are re-evaluated, tend to frustrate any serious environmental stewardship program. More proactive thinking embraces the identifying and aggressive follow-up toward closure of causes. In any organization where audits are a part of proactive environmental company policies, even the latter progressive approach may not be a high enough plateau. Progressive audit programs include also, the essential ingredient to evaluate program strengths, avoiding the disastrous perceptions that audit is an evaluation of job performances. Establishment of baseline trust emphasizing the positive as well as deficiencies reinforces cooperation and builds winning relationships. Assurances of the sustainability of compliance through employee efforts though, cannot be guaranteed no matter what the regulation or how strong the company policy. Guarantees are few, but a more assured reinforcement of sustained buy-in can be through the identification and communication of audit value and benefits. Value and benefits are often thought of in terms of helping facilities achieve and maintain compliance while avoiding notices of violation and fines. While these among other objectives are the foundation reasons for assessing, a deeper, big picture analysis of employee effort and measurable value is required. Skillful audit teams use their perspective to identify opportunities and take on non-traditional roles to assist facilities transcend corrective action toward and maintenance of compliance. A measurable value and benefits driven approach in association with compliance objectives, enhanced by strong communication, reinforces the very foundation of trust and stewardship within the organization.

  8. Measurements of light-absorbing particles on the glaciers in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

    2015-02-01

    Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light-absorbing particles sampled from glaciers during three surveys in the Cordillera Blanca Mountains in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, 240 snow samples were collected from 15 mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the 3 years and some mountains were sampled multiple times during the same year. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particles on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective black carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the LAHM analysis and the SP2 refractory black carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light-absorbing particles in the more polluted regions were likely BC. The 3 years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

  9. Measurements of light absorbing particulates on the glaciers in the Cordillera Blanca, Peru

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; All, J. D.; Schwarz, J. P.; Arnott, W. P.; Cole, R. J.; Lapham, E.; Celestian, A.

    2014-10-01

    Glaciers in the tropical Andes have been rapidly losing mass since the 1970s. In addition to the documented increase in air temperature, increases in light absorbing particulates deposited on glaciers could be contributing to the observed glacier loss. Here we report on measurements of light absorbing particulates sampled from glaciers during three surveys in the Cordillera Blanca in Peru. During three research expeditions in the dry seasons (May-August) of 2011, 2012 and 2013, two hundred and forty snow samples were collected from fifteen mountain peaks over altitudes ranging from 4800 to nearly 6800 m. Several mountains were sampled each of the three expeditions and some mountains were sampled multiple times during the same expedition. Collected snow samples were melted and filtered in the field then later analyzed using the Light Absorption Heating Method (LAHM), a new technique that measures the ability of particulates on filters to absorb visible light. LAHM results have been calibrated using filters with known amounts of fullerene soot, a common industrial surrogate for black carbon (BC). As sample filters often contain dust in addition to BC, results are presented in terms of effective Black Carbon (eBC). During the 2013 survey, snow samples were collected and kept frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated eBC mass from the filter analysis and the SP2 refractory Black Carbon (rBC) results were well correlated (r2 = 0.92). These results indicate that a substantial portion of the light absorbing particulates in the more polluted areas were likely BC. The three years of data show that glaciers in the Cordillera Blanca Mountains close to human population centers have substantially higher levels of eBC (as high as 70 ng g-1) than remote glaciers (as low as 2.0 ng g-1 eBC), indicating that population centers can influence local glaciers by sourcing BC.

  10. An overview of wideband immittance measurements techniques and terminology: You say absorbance, I say reflectance

    PubMed Central

    Rosowski, John J; Stenfelt, Stefan; Lilly, David

    2013-01-01

    This paper reviews the relationships among different acoustic measurements of the mobility of the tympanic membrane, including: impedance, admittance, reflectance and absorbance, which we group under the rubric of immittance measures. Each of these quantities is defined and related to the others. The relationship is most easily grasped in terms of a straight rigid ear canal of uniform area terminated by a uniform middle-ear immittance placed perpendicular to the long axis of the ear canal. Complications due to variations from this geometry are discussed. Different methods for measuring these quantities are described and the assumptions inherent within each method are made explicit. The benefits of wideband measurements of these quantities are described, as are the benefits and limitations of different components of immittance and reflectance/absorbance. While power reflectance (the square of the magnitude of pressure reflectance) is relatively invariant along the length of the ear canal, it has the disadvantage that it ignores phase information that may be useful in assessing the presence of acoustic leaks in ear-canal measurements and identifying other potential error sources. A combination of reflectance and impedance magnitude and angle give a more complete description of the middle ear from measurements in the ear canal. PMID:23900187

  11. Visual observation and quantitative measurement of the microwave absorbing effect at X band.

    PubMed

    Zhao, L; Chen, X; Ong, C K

    2008-12-01

    We have set up a two-dimensional spatial field mapping system to measure graphically the quasi-free-space electromagnetic wave in a parallel plate waveguide. Our apparatus illustrates a potential application in characterizing the microwave absorbing materials. From the measured mappings of the microwave field, the visualization of spatial physical process and quantitative characterization of reflectivity coefficients can be achieved. This simple apparatus has a remarkable advantage over with conventional testing methods which usually involve huge, expensive anechoic chambers and demand samples of large size. PMID:19123583

  12. Monte Carlo calculations and measurements of absorbed dose per monitor unit for the treatment of uveal melanoma with proton therapy

    PubMed Central

    Koch, Nicholas; Newhauser, Wayne D; Titt, Uwe; Gombos, Dan; Coombes, Kevin; Starkschall, George

    2014-01-01

    The treatment of uveal melanoma with proton radiotherapy has provided excellent clinical outcomes. However, contemporary treatment planning systems use simplistic dose algorithms that limit the accuracy of relative dose distributions. Further, absolute predictions of absorbed dose per monitor unit are not yet available in these systems. The purpose of this study was to determine if Monte Carlo methods could predict dose per monitor unit (D/MU) value at the center of a proton spread-out Bragg peak (SOBP) to within 1% on measured values for a variety of treatment fields relevant to ocular proton therapy. The MCNPX Monte Carlo transport code, in combination with realistic models for the ocular beam delivery apparatus and a water phantom, was used to calculate dose distributions and D/MU values, which were verified by the measurements. Measured proton beam data included central-axis depth dose profiles, relative cross-field profiles and absolute D/MU measurements under several combinations of beam penetration ranges and range-modulation widths. The Monte Carlo method predicted D/MU values that agreed with measurement to within 1% and dose profiles that agreed with measurement to within 3% of peak dose or within 0.5 mm distance-to-agreement. Lastly, a demonstration of the clinical utility of this technique included calculations of dose distributions and D/MU values in a realistic model of the human eye. It is possible to predict D/MU values accurately for clinical relevant range-modulated proton beams for ocular therapy using the Monte Carlo method. It is thus feasible to use the Monte Carlo method as a routine absolute dose algorithm for ocular proton therapy. PMID:18367789

  13. Absorbed dose measurements for kV-cone beam computed tomography in image-guided radiation therapy

    NASA Astrophysics Data System (ADS)

    Hioki, Kazunari; Araki, Fujio; Ohno, Takeshi; Nakaguchi, Yuji; Tomiyama, Yuuki

    2014-12-01

    In this study, we develope a novel method to directly evaluate an absorbed dose-to-water for kilovoltage-cone beam computed tomography (kV-CBCT) in image-guided radiation therapy (IGRT). Absorbed doses for the kV-CBCT systems of the Varian On-Board Imager (OBI) and the Elekta X-ray Volumetric Imager (XVI) were measured by a Farmer ionization chamber with a 60Co calibration factor. The chamber measurements were performed at the center and four peripheral points in body-type (30 cm diameter and 51 cm length) and head-type (16 cm diameter and 33 cm length) cylindrical water phantoms. The measured ionization was converted to the absorbed dose-to-water by using a 60Co calibration factor and a Monte Carlo (MC)-calculated beam quality conversion factor, kQ, for 60Co to kV-CBCT. The irradiation for OBI and XVI was performed with pelvis and head modes for the body- and the head-type phantoms, respectively. In addition, the dose distributions in the phantom for both kV-CBCT systems were calculated with MC method and were compared with measured values. The MC-calculated doses were calibrated at the center in the water phantom and compared with measured doses at four peripheral points. The measured absorbed doses at the center in the body-type phantom were 1.96 cGy for OBI and 0.83 cGy for XVI. The peripheral doses were 2.36-2.90 cGy for OBI and 0.83-1.06 cGy for XVI. The doses for XVI were lower up to approximately one-third of those for OBI. Similarly, the measured doses at the center in the head-type phantom were 0.48 cGy for OBI and 0.21 cGy for XVI. The peripheral doses were 0.26-0.66 cGy for OBI and 0.16-0.30 cGy for XVI. The calculated peripheral doses agreed within 3% in the pelvis mode and within 4% in the head mode with measured doses for both kV-CBCT systems. In addition, the absorbed dose determined in this study was approximately 4% lower than that in TG-61 but the absorbed dose by both methods was in agreement within their combined

  14. Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants

    SciTech Connect

    Anheier, Norman C.; Cannon, Bret D.; Kulkarni, Gourihar R.; Munley, John T.; Nelson, Danny A.; Qiao, Hong; Phillips, Jon R.

    2012-07-17

    Laser Ablation Absorbance Ratio Spectrometry (LAARS) is a new verification measurement technology under development at the US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL). LAARS uses three lasers to ablate and then measure the relative isotopic abundance of uranium compounds. An ablation laser is tightly focused on uranium-bearing solids, producing a small atomic uranium vapor plume. Two collinear wavelength-tuned spectrometry lasers transit through the plume and the absorbance of U-235 and U-238 isotopes are measured to determine U-235 enrichment. The measurement is independent of chemical form and degree of dilution with nuisance dust and other materials. LAARS has high relative precision and detection limits approaching the femtogram range for U-235. The sample is scanned and assayed point-by-point at rates reaching 1 million measurements/hour, enabling LAARS to detect and analyze uranium in trace samples. The spectrometer is assembled using primarily commercially available components and features a compact design and automated analysis.Two specific gaseous centrifuge enrichment plant (GCEP) applications of the spectrometer are currently under development: 1) LAARS-Environmental Sampling (ES), which collects and analyzes aerosol particles for GCEP misuse detection and 2) LAARS-Destructive Assay (DA), which enables onsite enrichment DA sample collection and analysis for protracted diversion detection. The two applications propose game-changing technological advances in GCEP safeguards verification.

  15. Electron paramagnetic resonance measurements of absorbed dose in teeth from citizens of Ozyorsk.

    PubMed

    Wieser, A; Vasilenko, E; Aladova, E; Fattibene, P; Semiochkina, N; Smetanin, M

    2014-05-01

    In 1945, within the frame of the Uranium Project for the production of nuclear weapons, the Mayak nuclear facilities were constructed at the Lake Irtyash in the Southern Urals, Russia. The nuclear workers of the Mayak Production Association (MPA), who lived in the city of Ozyorsk, are the focus of epidemiological studies for the assessment of health risks due to protracted exposure to ionising radiation. Electron paramagnetic resonance measurements of absorbed dose in tooth enamel have already been used in the past, in an effort to validate occupational external doses that were evaluated in the Mayak Worker Dosimetry System. In the present study, 229 teeth of Ozyorsk citizens not employed at MPA were investigated for the assessment of external background exposure in Ozyorsk. The annually absorbed dose in tooth enamel from natural background radiation was estimated to be (0.7 ± 0.3) mGy. For citizens living in Ozyorsk during the time of routine noble gas releases of the MPA, which peaked in 1953, the average excess absorbed dose in enamel above natural background was (36 ± 29) mGy, which is consistent with the gamma dose obtained by model calculations. In addition, there were indications of possible accidental gaseous MPA releases that affected the population of Ozyorsk, during the early and late MPA operation periods, before 1951 and after 1960. PMID:24604722

  16. Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

    SciTech Connect

    Dubey, P. K. Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

    2014-05-15

    The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

  17. Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target.

    PubMed

    Dubey, P K; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

    2014-05-01

    The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique. PMID:24880401

  18. Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

    NASA Astrophysics Data System (ADS)

    Dubey, P. K.; Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

    2014-05-01

    The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

  19. Temperature measurements behind reflected shock waves in air. [radiometric measurement of gas temperature in self-absorbing gas flow

    NASA Technical Reports Server (NTRS)

    Bader, J. B.; Nerem, R. M.; Dann, J. B.; Culp, M. A.

    1972-01-01

    A radiometric method for the measurement of gas temperature in self-absorbing gases has been applied in the study of shock tube generated flows. This method involves making two absolute intensity measurements at identical wavelengths, but for two different pathlengths in the same gas sample. Experimental results are presented for reflected shock waves in air at conditions corresponding to incident shock velocities from 7 to 10 km/s and an initial driven tube pressure of 1 torr. These results indicate that, with this technique, temperature measurements with an accuracy of + or - 5 percent can be carried out. The results also suggest certain facility related problems.

  20. A Comparison of Model Calculation and Measurement of Absorbed Dose for Proton Irradiation. Chapter 5

    NASA Technical Reports Server (NTRS)

    Zapp, N.; Semones, E.; Saganti, P.; Cucinotta, F.

    2003-01-01

    With the increase in the amount of time spent EVA that is necessary to complete the construction and subsequent maintenance of ISS, it will become increasingly important for ground support personnel to accurately characterize the radiation exposures incurred by EVA crewmembers. Since exposure measurements cannot be taken within the organs of interest, it is necessary to estimate these exposures by calculation. To validate the methods and tools used to develop these estimates, it is necessary to model experiments performed in a controlled environment. This work is such an effort. A human phantom was outfitted with detector equipment and then placed in American EMU and Orlan-M EVA space suits. The suited phantom was irradiated at the LLUPTF with proton beams of known energies. Absorbed dose measurements were made by the spaceflight operational dosimetrist from JSC at multiple sites in the skin, eye, brain, stomach, and small intestine locations in the phantom. These exposures are then modeled using the BRYNTRN radiation transport code developed at the NASA Langley Research Center, and the CAM (computerized anatomical male) human geometry model of Billings and Yucker. Comparisons of absorbed dose calculations with measurements show excellent agreement. This suggests that there is reason to be confident in the ability of both the transport code and the human body model to estimate proton exposure in ground-based laboratory experiments.

  1. Multichord time-resolved electron temperature measurements by the x-ray absorber-foil method on TFTR

    SciTech Connect

    Kiraly, J.; Bitter, M.; Efthimion, P.; von Goeler, S.; Grek, B.; Hill, K.W.; Johnson, D.; McGuire, K.; Sauthoff, N.; Sesnic, S.

    1985-09-01

    Absorber foils have been installed in the TFTR X-Ray Imaging System to permit measurement of the electron temperature along 10 to 30 chords spaced at 5-12.5 cm with a time resolution of less than 100 ..mu..s. The technique uses the ratio of x-ray fluxes transmitted through two different foils. The ratio depends mainly on electron temperature. Simulations show that strong impurity line radiation can distort this ratio. To correct for these effects, special beryllium-scandium filters are employed to select the line-free region between 2 and 4.5 keV. Other filter pairs allow corrections for Fe L and Ni L line radiation as well as Ti K and Ni K emission. Good accuracy is also obtained with simple beryllium filters, provided that impurity corrections are incorporated in the analysis, taking line intensities from the x-ray pulse-height analysis diagnostic. A description of modeling calculations and a comparison of temperature values from this diagnostic with data from the x-ray pulse height analysis, the electron cyclotron emission, and the Thomson scattering diagnostics are presented. Several applications of the absorber foil electron temperature diagnostic on TFTR are discussed.

  2. Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants

    SciTech Connect

    Anheier, Norman C.; Cannon, Bret D.; Qiao, Hong; Phillips, Jon R.

    2012-07-01

    Laser Ablation Absorbance Ratio Spectrometry (LAARS) is a new verification measurement technology under development at the US Department of Energy’s (DOE) Pacific Northwest National Laboratory (PNNL). LAARS uses three lasers to ablate and then measure the relative isotopic abundance of uranium compounds. An ablation laser is tightly focused on uranium-bearing solids producing a small plume containing uranium atoms. Two collinear wavelength-tuned spectrometry lasers transit through the plume and the absorbance of U-235 and U-238 isotopes are measured to determine U-235 enrichment. The measurement has high relative precision and detection limits approaching the femtogram range for uranium. It is independent of chemical form and degree of dilution with nuisance dust and other materials. High speed sample scanning and pinpoint characterization allow measurements on millions of particles/hour to detect and analyze the enrichment of trace uranium in samples. The spectrometer is assembled using commercially available components at comparatively low cost, and features a compact and low power design. Future designs can be engineered for reliable, autonomous deployment within an industrial plant environment. Two specific applications of the spectrometer are under development: 1) automated unattended aerosol sampling and analysis and 2) on-site small sample destructive assay measurement. The two applications propose game-changing technological advances in gaseous centrifuge enrichment plant (GCEP) safeguards verification. The aerosol measurement instrument, LAARS-environmental sampling (ES), collects aerosol particles from the plant environment in a purpose-built rotating drum impactor and then uses LAARS-ES to quickly scan the surface of the impactor to measure the enrichments of the captured particles. The current approach to plant misuse detection involves swipe sampling and offsite analysis. Though this approach is very robust it generally requires several months to

  3. Dualex: A New Instrument for Field Measurements of Epidermal Ultraviolet Absorbance by Chlorophyll Fluorescence

    NASA Astrophysics Data System (ADS)

    Goulas, Yves; Cerovic, Zoran G.; Cartelat, Aurélie; Moya, Ismaël

    2004-08-01

    Dualex (dual excitation) is a field-portable instrument, hereby described, for the assessment of polyphenolic compounds in leaves from the measurement of UV absorbance of the leaf epidermis by double excitation of chlorophyll fluorescence. The instrument takes advantage of a feedback loop that equalizes the fluorescence level induced by a reference red light to the UV-light-induced fluorescence level. This allows quick measurement from attached leaves even under field conditions. The use of light-emitting diodes and of a leaf-clip configuration makes Dualex a user-friendly instrument with potential applications in ecophysiological research, light climate analysis, agriculture, forestry, horticulture, pest management, selection of medicinal plants, and wherever accumulation of leaf polyphenolics is involved in plant responses to the environment.

  4. Concentration measurements of complex mixtures of broadband absorbers by widely tunable optical parametric oscillator laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Ruxton, K.; Macleod, N. A.; Weidmann, D.; Malcolm, G. P. A.; Maker, G. T.

    2012-11-01

    The ability to obtain accurate vapour parameter information from a compound's absorption spectrum is an essential data processing application in order to quantify the presence of an absorber. Concentration measurements can be required for a variety of applications including environmental monitoring, pipeline leak detection, surface contamination and breath analysis. This work demonstrates sensitive concentration measurements of complex mixtures of volatile organic compounds (VOCs) using broadly tunable mid wave infrared (MWIR) laser spectroscopy. Due to the high absorption cross-sections, the MWIR spectral region is ideal to carry out sensitive concentration measurements of VOCs by tunable laser absorption spectroscopy (TLAS) methods. Absorption spectra of mixtures of VOCs were recorded using a MWIR optical parametric oscillator (OPO), with a tuning range covering 2.5 μm to 3.7 μm. The output of the MWIR OPO was coupled to a multi-pass astigmatic Herriott gas cell, maintained at atmospheric pressure that can provide up to 210 m of absorption path length, with the transmission output from the cell being monitored by a detector. The resulting spectra were processed by a concentration retrieval algorithm derived from the optimum estimation method, taking into account both multiple broadband absorbers and interfering molecules that exhibit narrow multi-line absorption features. In order to demonstrate the feasibility of the concentration measurements and assess the capability of the spectral processor, experiments were conducted on calibrated VOCs vapour mixtures flowing through the spectroscopic cell with concentrations ranging from parts per billion (ppb) to parts per million (ppm). This work represents as a first step in an effort to develop and apply a similar concentration fitting algorithm to hyperspectral images in order to provide concentration maps of the spatial distribution of multi-species vapours. The reported functionality of the novel fitting algorithm

  5. Measuring Moral Values in Public Relations.

    ERIC Educational Resources Information Center

    Wright, Donald K.

    A study was conducted to examine the ethical and moral values of public relations personnel. Subjects were 105 American public relations practitioners, 104 Canadian practitioners, and 215 public relations students. Subjects completed an instrument based on P. Crissman's scale of moral value judgments, which contained 50 items scored on a…

  6. Values and Public Dissent: I - Preliminary Measures.

    ERIC Educational Resources Information Center

    Berrien, F.K.; Turner, Floyd D.

    Founded on a systems model of political processes and a review of studies relating values to political controls, 90 value items were administered to "mainstream" and "eddy" (dissenting) groups, including moderate and radical students, Rotarians, member of the New Democratic Coalition, Navy enlisted men, and Navy brig prisoners for the purpose of…

  7. Laser measurement of the spectral extinction coefficients of fluorescent, highly absorbing liquids. [crude petroleum oils

    NASA Technical Reports Server (NTRS)

    Hoge, F. E.

    1982-01-01

    A conceptual method is developed to deduce rapidly the spectral extinction coefficient of fluorescent, highly absorbing liquids, such as crude or refined petroleum oils. The technique offers the advantage of only requiring one laser wavelength and a single experimental assembly and execution for any specific fluorescent liquid. The liquid is inserted into an extremely thin wedge-shaped cavity for stimulation by a laser from one side and flurescence measurement on the other side by a monochromator system. For each arbitrarily selected extinction wavelength, the wedge is driven slowly to increasing thicknesses until the fluorescence extinguishes. The fluorescence as a function of wedge thickness permits a determination of the extinction coefficient using an included theoretical model. When the monochromator is set to the laser emission wavelength, the extinction coefficient is determined using the usual on-wavelength signal extinction procedure.

  8. Millimeter wave complex dielectric permittivity and complex magnetic permeability measurements of absorbing materials

    NASA Astrophysics Data System (ADS)

    Tkachov, Igor Ivanovich

    2000-09-01

    This dissertation presents new methods for characterization of materials in the millimeter wave range. Historically, this has been the most difficult part of the electromagnetic spectrum for accurate measurements of material properties. New instrumentation has now been developed for operation in this frequency band. The new techniques developed in the course of this work allowed precise measurement of dielectric properties as well as the separation of magnetic properties from dielectric in the millimeter wave range. A new quasi-optical spectrometer with a waveguide reference channel has been designed and built for the precision measurement of the real part of dielectric permittivity of medium and highly absorbing materials over an extended W-band frequency range (70-118 GHz). A new method of phase measurement with this unique unbalanced quasi-optical waveguide bridge spectrometer has been developed. The phase of the electromagnetic wave transmitted through the specimen can be measured accurately, leading to the determination of the real part of the complex dielectric permittivity of moderate and highly absorbing dielectric materials with high precision. A simple quasi-optical transmission configuration of the spectrometer, a single free space channel provides the transmittance data with a high resolution from which the spectra of the imaginary part of dielectric permittivity of materials are evaluated accurately. A backward wave oscillator (BWO) is used as the source of tunable coherent radiation for the spectrometer. The high output power of the BWO and the high sensitivity of the receiver system, which employs a specially constructed liquid helium cooled InSb detector, enable adequate sensitivity in transmission for highly absorbing materials. Systematic study of dielectric and magnetic properties of various materials has been performed with the quasi-optical free space method in the millimeter wave range from 34GHz to 117GHz for the first time. Specific results

  9. Myoplasmic binding of fura-2 investigated by steady-state fluorescence and absorbance measurements.

    PubMed Central

    Konishi, M; Olson, A; Hollingworth, S; Baylor, S M

    1988-01-01

    Binding of the fluorescent Ca2+ indicator dye fura-2 by intracellular constituents has been investigated by steady-state optical measurements. Fura-2's (a) fluorescence intensity, (b) fluorescence emission anisotropy, (c) fluorescence emission spectrum, and (d) absorbance spectra were measured in glass capillary tubes containing solutions of purified myoplasmic proteins; properties b and c were also measured in frog skeletal muscle fibers microinjected with fura-2. The results indicate that more than half, and possibly as much as 85%, of fura-2 molecules in myoplasm are in a protein-bound form, and that the binding changes many properties of the dye. For example, in vitro characterization of the Ca2+-dye reaction indicates that when fura-2 is bound to aldolase (a large and abundant myoplasmic protein), the dissociation constant of the dye for Ca2+ is three- to fourfold larger than that measured in the absence of protein. The problems raised by intracellular binding of fura-2 to cytoplasmic proteins may well apply to cells other than skeletal muscle fibers. PMID:3266079

  10. Cultural Value, Measurement and Policy Making

    ERIC Educational Resources Information Center

    O'Brien, Dave

    2015-01-01

    No matter what the national context, the question of how to understand the impact of government programmes, particularly in terms of value for money, has emerged as a complex problem to be solved by social scientific management. This article engages with these trends in two ways. It focuses on the UK to understand how these tools and technologies…

  11. Estimation of the absorbed dose in radiation-processed food. 4. EPR measurements on eggshell

    SciTech Connect

    Desrosiers, M.F.; Le, F.G. ); Harewood, P.M.; Josephson, E.S. ); Montesalvo, M. )

    1993-09-01

    Fresh whole eggs treated with ionizing radiation for Salmonellae control testing. The eggshell was then removed and examined by electron paramagnetic resonance (EPR) spectroscopy to determine if EPR could be used to (1) distinguish irradiated from unirradiated eggs and (2) assess the absorbed dose. No EPR signals were detected in unirradiated eggs, while strong signals were measurable for more than 200 days after irradiation. Although a number of EPR signals were measured, the most intense resonance (g = 2.0019) was used for dosimetry throughout the study. This signal was observed to increase linearly with dose (up to [approximately]6 kGy), which decayed [approximately]20% within the first 5 days after irradiation and remained relatively constant thereafter. The standard added-dose method was used to assess, retrospectively, the dose to eggs processed at 0.2, 0.7, and 1.4 kGy. Relatively good results were obtained when measurement was made on the day the shell was reirradiated; with this procedure estimates were better for shell processed at the lower doses.

  12. Influence of Diffraction Effects on the Result of Measuring the Absorption Coefficient of Ultrasound in Weakly Absorbing Liquids by the Pulse Method

    NASA Astrophysics Data System (ADS)

    Shatsky, A. V.

    2016-08-01

    We consider the problem of the influence of diffraction effects on the result of measuring the absorption coefficient of ultrasound in weakly absorbing liquids by the pulse method. Diffraction attenuation of an ultrasonic signal in a measuring cell using solid-state delay lines is calculated. It is shown that the use of delay lines of the ultrasonic signal leads to a considerable distortion of the measured absorption coefficient in the low-frequency range from the true value and can either overestimate or underestimate the results.

  13. Simultaneous measurement of changes in thickness and refractive index of weakly absorbing self-standing solid films using optical interferometry

    NASA Astrophysics Data System (ADS)

    Easwar, N.; Fantini, R.; Willis, E.

    2001-06-01

    A nondestructive optical interferometric method, which enables a direct and simultaneous measurement of small changes in both thickness and refractive index of thin films, is described. Optical interferometric methods are sensitive to the changes in the optical path length (the product of the refractive index and the physical thickness) through the film. Thus, when the film is subjected to changing environmental conditions such as changing temperature or humidity, it is a challenge to determine the change in thickness and the change in refractive index separately, using interferometry. By simultaneously monitoring two different sets of interference fringes, i.e., transmission and reflection fringes, we have been able to successfully address this challenge. Our measurements on well-characterized pedigree glass samples are presented. The results agree well with the expected values for these samples, supporting the feasibility of this characterization technique to new materials. Self-standing, transparent (weakly absorbing) films ranging in thickness from tens to hundreds of microns can be characterized from direct measurements.

  14. Light-absorbing Particles in Snow and Ice: Measurement and Modeling of Climatic and Hydrological Impact

    SciTech Connect

    Qian, Yun; Yasunari, Teppei J.; Doherty, Sarah J.; Flanner, M. G.; Lau, William K.; Ming, J.; Wang, Hailong; Wang, Mo; Warren, Stephen G.; Zhang, Rudong

    2015-01-01

    Light absorbing particles (LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance (a.k.a., surface darkening), which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice (LAPSI) has been identified as one of major forcings affecting climate change, e.g. in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this review paper, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the mass concentrations, albedo reduction, radiative forcing, andclimatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle.

  15. Measurement of absorbed dose-to-water for an HDR {sup 192}Ir source with ionization chambers in a sandwich setup

    SciTech Connect

    Araki, Fujio; Kouno, Tomohiro; Ohno, Takeshi; Kakei, Kiyotaka; Yoshiyama, Fumiaki; Kawamura, Shinji

    2013-09-15

    Purpose: In this study, a dedicated device for ion chamber measurements of absorbed dose-to-water for a Nucletron microSelectron-v2 HDR {sup 192}Ir brachytherapy source is presented. The device uses two ionization chambers in a so-called sandwich assembly. Using this setup and by taking the average reading of the two chambers, any dose error due to difficulties in absolute positioning (centering) of the source in between the chambers is cancelled to first order. The method's accuracy was examined by comparing measurements with absorbed dose-to-water determination based on the AAPM TG-43 protocol.Methods: The optimal source-to-chamber distance (SCD) for {sup 192}Ir dosimetry was determined from ion chamber measurements in a water phantom. The {sup 192}Ir source was sandwiched between two Exradin A1SL chambers (0.057 cm{sup 3}) at the optimal SCD separation. The measured ionization was converted to the absorbed dose-to-water using a {sup 60}Co calibration factor and a Monte Carlo-calculated beam quality conversion factor, k{sub Q}, for {sup 60}Co to {sup 192}Ir. An uncertainty estimate of the proposed method was determined based on reproducibility of measurements at different institutions for the same type of source.Results: The optimal distance for the A1SL chamber measurements was determined to be 5 cm from the {sup 192}Ir source center, considering the depth dependency of k{sub Q} for {sup 60}Co to {sup 192}Ir and the chamber positioning. The absorbed dose to water measured at (5 cm, 90°) on the transverse axis was 1.3% lower than TG-43 values and its reproducibility and overall uncertainty were 0.8% and 1.7%, respectively. The measurement doses at anisotropic points agreed within 1.5% with TG-43 values.Conclusions: The ion chamber measurement of absorbed dose-to-water with a sandwich method for the {sup 192}Ir source provides a more accurate, direct, and reference dose compared to the dose-to-water determination based on air-kerma strength in the TG-43 protocol

  16. Measuring the value of healthcare business assets.

    PubMed

    Evans, C J

    2000-04-01

    Healthcare organizations obtain valuations of business assets for many reasons, including to support decisions regarding potential mergers, sale of business components, or financing; for tax assessments; and for defense against law-suits. If compliance with regulations may be an issue, such as when a not-for-profit organization is involved in a transaction, healthcare organizations should seek an independent appraisal to ensure that applicable legal standards are met. Whether or not regulatory issues are involved, however, an accurate and useful valuation of business assets depends on many factors. Financial managers must understand the purpose and function of the valuation, choice of appropriate valuation techniques, proper assessment of intangible value, use of realistic growth rates, appropriate emphasis on key focus areas of the valuation (e.g., risk and future income streams), and an accounting of physician compensation. PMID:10915353

  17. Instrumentation and method for measuring NIR light absorbed in tissue during MR imaging in medical NIRS measurements

    NASA Astrophysics Data System (ADS)

    Myllylä, Teemu S.; Sorvoja, Hannu S. S.; Nikkinen, Juha; Tervonen, Osmo; Kiviniemi, Vesa; Myllylä, Risto A.

    2011-07-01

    Our goal is to provide a cost-effective method for examining human tissue, particularly the brain, by the simultaneous use of functional magnetic resonance imaging (fMRI) and near-infrared spectroscopy (NIRS). Due to its compatibility requirements, MRI poses a demanding challenge for NIRS measurements. This paper focuses particularly on presenting the instrumentation and a method for the non-invasive measurement of NIR light absorbed in human tissue during MR imaging. One practical method to avoid disturbances in MR imaging involves using long fibre bundles to enable conducting the measurements at some distance from the MRI scanner. This setup serves in fact a dual purpose, since also the NIRS device will be less disturbed by the MRI scanner. However, measurements based on long fibre bundles suffer from light attenuation. Furthermore, because one of our primary goals was to make the measuring method as cost-effective as possible, we used high-power light emitting diodes instead of more expensive lasers. The use of LEDs, however, limits the maximum output power which can be extracted to illuminate the tissue. To meet these requirements, we improved methods of emitting light sufficiently deep into tissue. We also show how to measure NIR light of a very small power level that scatters from the tissue in the MRI environment, which is characterized by strong electromagnetic interference. In this paper, we present the implemented instrumentation and measuring method and report on test measurements conducted during MRI scanning. These measurements were performed in MRI operating rooms housing 1.5 Tesla-strength closed MRI scanners (manufactured by GE) in the Dept. of Diagnostic Radiology at the Oulu University Hospital.

  18. A Deep Search For Faint Galaxies Associated With Very Low-redshift C IV Absorbers. II. Program Design, Absorption-line Measurements, and Absorber Statistics

    NASA Astrophysics Data System (ADS)

    Burchett, Joseph N.; Tripp, Todd M.; Prochaska, J. Xavier; Werk, Jessica K.; Tumlinson, Jason; O'Meara, John M.; Bordoloi, Rongmon; Katz, Neal; Willmer, C. N. A.

    2015-12-01

    To investigate the evolution of metal-enriched gas over recent cosmic epochs as well as to characterize the diffuse, ionized, metal-enriched circumgalactic medium, we have conducted a blind survey for C iv absorption systems in 89 QSO sightlines observed with the Hubble Space Telescope Cosmic Origins Spectrograph. We have identified 42 absorbers at z < 0.16, comprising the largest uniform blind sample size to date in this redshift range. Our measurements indicate an increasing C iv absorber number density per comoving path length (d{N}/{dX}= 7.5 ± 1.1) and modestly increasing mass density relative to the critical density of the universe (ΩC iv = 10.0 ± 1.5 × 10-8) from z ˜ 1.5 to the present epoch, consistent with predictions from cosmological hydrodynamical simulations. Furthermore, the data support a functional form for the column density distribution function that deviates from a single power law, also consistent with independent theoretical predictions. As the data also probe heavy element ions in addition to C iv at the same redshifts, we identify, measure, and search for correlations between column densities of these species where components appear to be aligned in velocity. Among these ion-ion correlations, we find evidence for tight correlations between C ii and Si ii, C ii and Si iii, and C iv and Si iv, suggesting that these pairs of species arise in similar ionization conditions. However, the evidence for correlations decreases as the difference in ionization potential increases. Finally, when controlling for observational bias, we find only marginal evidence for a correlation (86.8% likelihood) between the Doppler line width b(C iv) and column density N(C iv).

  19. Screening and monitoring microbial xenobiotics’ biodegradation by rapid, inexpensive and easy to perform microplate UV-absorbance measurements

    PubMed Central

    2014-01-01

    Background Evaluation of xenobiotics biodegradation potential, shown here for benzotriazoles (corrosion inhibitors) and sulfamethoxazole (sulfonamide antibiotic) by microbial communities and/or pure cultures normally requires time intensive and money consuming LC/GC methods that are, in case of laboratory setups, not always needed. Results The usage of high concentrations to apply a high selective pressure on the microbial communities/pure cultures in laboratory setups, a simple UV-absorbance measurement (UV-AM) was developed and validated for screening a large number of setups, requiring almost no preparation and significantly less time and money compared to LC/GC methods. This rapid and easy to use method was evaluated by comparing its measured values to LC-UV and GC-MS/MS results. Furthermore, its application for monitoring and screening unknown activated sludge communities (ASC) and mixed pure cultures has been tested and approved to detect biodegradation of benzotriazole (BTri), 4- and 5-tolyltriazole (4-TTri, 5-TTri) as well as SMX. Conclusions In laboratory setups, xenobiotics concentrations above 1.0 mg L-1 without any enrichment or preparation could be detected after optimization of the method. As UV-AM does not require much preparatory work and can be conducted in 96 or even 384 well plate formats, the number of possible parallel setups and screening efficiency was significantly increased while analytic and laboratory costs were reduced to a minimum. PMID:24558966

  20. Measurement of absorbed dose to water around an electronic brachytherapy source. Comparison of two dosimetry systems: lithium formate EPR dosimeters and radiochromic EBT2 film

    NASA Astrophysics Data System (ADS)

    Adolfsson, Emelie; White, Shane; Landry, Guillaume; Lund, Eva; Gustafsson, Håkan; Verhaegen, Frank; Reniers, Brigitte; Carlsson Tedgren, Åsa; Alm Carlsson, Gudrun

    2015-05-01

    Interest in high dose rate (HDR) electronic brachytherapy operating at 50 kV is increasing. For quality assurance it is important to identify dosimetry systems that can measure the absorbed doses in absolute terms which is difficult in this energy region. In this work a comparison is made between two dosimetry systems, EPR lithium formate dosimeters and radiochromic EBT2 film. Both types of dosimeters were irradiated simultaneously in a PMMA phantom using the Axxent EBS. Absorbed dose to water was determined at distances of 10 mm, 30 mm and 50 mm from the EBS. Results were traceable to different primary standards as regards to absorbed dose to water (EPR) and air kerma (EBT2). Monte Carlo simulations were used in absolute terms as a third estimate of absorbed dose to water. Agreement within the estimated expanded (k = 2) uncertainties (5% (EPR), 7% (EBT2)) was found between the results at 30 mm and 50 mm from the x-ray source. The same result was obtained in 4 repetitions of irradiation, indicating high precision in the measurements with both systems. At all distances, agreement between EPR and Monte Carlo simulations was shown as was also the case for the film measurements at 30mm and 50mm. At 10mm the geometry for the film measurements caused too large uncertainty in measured values depending on the exact position (within sub-mm distances) of the EBS and the 10 mm film results were exculded from comparison. This work has demonstrated good performance of the lithium formate EPR dosimetry system in accordance with earlier experiments at higher photon energies (192Ir HDR brachytherapy). It was also highlighted that there might be issues regarding the energy dependence and intrinsic efficiency of the EBT2 film that need to be considered for measurements using low energy sources.

  1. Measuring the value of customer retention

    SciTech Connect

    Monts, K.; Bonevac, B.; Lauer, J.; Tessema, D.

    1997-05-01

    Competition will require changes in how market research is conducted and how customers are pursued. The question remains: How does one approach customer retention in a way that provides meaningful guidelines? The conventional wisdom is that {open_quotes}the business of business is selling.{close_quotes} There is some truth to this, but the key question today is: What bearing does this have on how to run a business in a competitive environment? A recent article in the Harvard Business Review noted that, {open_quotes}Increasingly, companies are less focused on selling products and more interested in keeping customers.{close_quotes} Indeed, some observers have posited a natural societal evolutionary trend toward a shift of emphasis toward customer retention vis-a-vis customer acquisition, as a consequence of the primary marketing communication technology shifting from {open_quotes}broadcast{close_quotes} (where messages are sent out to inchoate masses) to {open_quotes}interactive{close_quotes} (where relationships are cultivated with precisely defined market niches or individual customers). The business of growing a business, then, can be framed as a matter of getting customers and keeping them so as to grow the value of the customer base to its fullest potential. In these terms, setting a marketing budget becomes the task of balancing what is spent on customer acquisition with what is spent on retention.

  2. Measurement, simulation on dynamic characteristics of a wire gauze fluid damping shock absorber

    NASA Astrophysics Data System (ADS)

    Ping, Yang; Yonghong, Tan; Jianmin, Yang; Nin, Sun

    2006-04-01

    A new kind of shock absorber with Coulomb-fluid damping through coupling oil, wire gauze, rubber and spring by ingenious tactics is designed for reinforcement of electronic-information equipment in atrocious vibration and impact. The physical mechanism of the shock absorber is systematically investigated. The key-model machine shows complex non-linear dynamic characteristics in multi-parameter coupling dynamic test; otherwise, it has a good dynamic performance for attenuating vibration and resisting violent impact. Based on this, the non-linear dynamic model for attenuating vibration mode of the shock absorber is presented by analysing coupling physical mechanism of fluid and Coulomb friction and other factors for designing the shock absorber with high validity. The analytical results obtained in experimental data have been compared with the numerical ones obtained by performing the Runge-Kutta method with the mathematical model. As the model results agree well with the test data, it can be used for engineering design.

  3. Measurements of a prototype synchrotron radiation pumped absorber for future light sources

    NASA Astrophysics Data System (ADS)

    Chou, T. S.; Foerster, C. L.; Halama, H.; Lanni, C.

    1988-09-01

    In the new generation of advanced synchrotron light sources, the conventional concept of distributed pumping is no longer suitable for removing the gas load caused by photon stimulated desorption (PSD). A new concept using a combination of photon absorber and pumping station has been designed, constructed, and installed in the U10B beam line at the VUV ring of the National Synchrotron Light Source. The system consists of an electrically insulated water cooled copper block, a titanium sublimation pump, calibrated BA gauges, a calibrated RGA, and a known conductance. A photon beam 10 milliradian wide and 3.26 milliradian high, having critical energy of 500 eV, is directed on the absorber. PSD yield is studied as a function of total beam dose and absorber surface preparation. The results from this experiment, pump characteristics, design of an absorber pump for future light sources, and the pressure improvement factors will be presented.

  4. Measurements of a prototype synchrotron radiation pumped absorber for future light sources

    SciTech Connect

    Chou, T.S.; Foerster, C.L.; Halama, H.; Lanni, C.

    1988-01-01

    In the new generation of advanced synchrotron light sources, the conventional concept of distributed pumping is no longer suitable for removing the gas load caused by photon stimulated desorption (PSD). A new concept using a combination of photon absorber and pumping station has been designed, constructed, and installed in the U1OB beam line at the VUV ring of the National Synchrotron Light Source. The system consists of an electrically insulated water cooled copper block, a titanium sublimation pump, calibrated BA gauges, a calibrated RGA, and a known conductance. A photon beam 10 milliradian wide and 3.26 milliradian high, having critical energy of 500 eV, is directed on the absorber. PSD yield is studied as a function of total beam dose and absorber surface preparation. The results from this experiment, pump characteristics, design of an absorber pump for future light sources, and the pressure improvement factors will be presented. 5 refs., 7 figs., 1 tab.

  5. Measuring agglomerate size distribution and dependence of localized surface plasmon resonance absorbance on gold nanoparticle agglomerate size using analytical ultracentrifugation.

    PubMed

    Zook, Justin M; Rastogi, Vinayak; Maccuspie, Robert I; Keene, Athena M; Fagan, Jeffrey

    2011-10-25

    Agglomeration of nanoparticles during measurements in relevant biological and environmental media is a frequent problem in nanomaterial property characterization. The primary problem is typically that any changes to the size distribution can dramatically affect the potential nanotoxicity or other size-determined properties, such as the absorbance signal in a biosensor measurement. Herein we demonstrate analytical ultracentrifugation (AUC) as a powerful method for measuring two critical characteristics of nanoparticle (NP) agglomerates in situ in biological media: the NP agglomerate size distribution, and the localized surface plasmon resonance (LSPR) absorbance spectrum of precise sizes of gold NP agglomerates. To characterize the size distribution, we present a theoretical framework for calculating the hydrodynamic diameter distribution of NP agglomerates from their sedimentation coefficient distribution. We measure sedimentation rates for monomers, dimers, and trimers, as well as for larger agglomerates with up to 600 NPs. The AUC size distributions were found generally to be broader than the size distributions estimated from dynamic light scattering and diffusion-limited colloidal aggregation theory, an alternative bulk measurement method that relies on several assumptions. In addition, the measured sedimentation coefficients can be used in nanotoxicity studies to predict how quickly the agglomerates sediment out of solution under normal gravitational forces, such as in the environment. We also calculate the absorbance spectra for monomer, dimer, trimer, and larger gold NP agglomerates up to 600 NPs, to enable a better understanding of LSPR biosensors. Finally, we validate a new method that uses these spectra to deconvolute the net absorbance spectrum of an unknown bulk sample and approximate the proportions of monomers, dimers, and trimers in a polydisperse sample of small agglomerates, so that every sample does not need to be measured by AUC. These results

  6. Measured Wavelength-Dependent Absorption Enhancement of Internally Mixed Black Carbon with Absorbing and Nonabsorbing Materials.

    PubMed

    You, Rian; Radney, James G; Zachariah, Michael R; Zangmeister, Christopher D

    2016-08-01

    Optical absorption spectra of laboratory generated aerosols consisting of black carbon (BC) internally mixed with nonabsorbing materials (ammonium sulfate, AS, and sodium chloride, NaCl) and BC with a weakly absorbing brown carbon surrogate derived from humic acid (HA) were measured across the visible to near-IR (550 to 840 nm). Spectra were measured in situ using a photoacoustic spectrometer and step-scanning a supercontinuum laser source with a tunable wavelength and bandwidth filter. BC had a mass-specific absorption cross section (MAC) of 7.89 ± 0.25 m(2) g(-1) at λ = 550 nm and an absorption Ångström exponent (AAE) of 1.03 ± 0.09 (2σ). For internally mixed BC, the ratio of BC mass to the total mass of the mixture was chosen as 0.13 to mimic particles observed in the terrestrial atmosphere. The manner in which BC mixed with each material was determined from transmission electron microscopy (TEM). AS/BC and HA/BC particles were fully internally mixed, and the BC was both internally and externally mixed for NaCl/BC particles. The AS/BC, NaCl/BC, and HA/BC particles had AAEs of 1.43 ± 0.05, 1.34 ± 0.06, and 1.91 ± 0.05, respectively. The observed absorption enhancement of mixed BC relative to the pure BC was wavelength dependent for AS/BC and decreased from 1.5 at λ = 550 nm with increasing wavelength while the NaCl/BC enhancement was essentially wavelength independent. For HA/BC, the enhancement ranged from 2 to 3 and was strongly wavelength dependent. Removal of the HA absorption contribution to enhancement revealed that the enhancement was ≈1.5 and independent of wavelength. PMID:27359341

  7. Electron absorbed fractions of energy and S-values in an adult human skeleton based on µCT images of trabecular bone

    NASA Astrophysics Data System (ADS)

    Kramer, R.; Richardson, R. B.; Cassola, V. F.; Vieira, J. W.; Khoury, H. J.; Lira, C. A. B. de O.; Robson Brown, K.

    2011-03-01

    When the human body is exposed to ionizing radiation, among the soft tissues at risk are the active marrow (AM) and the bone endosteum (BE) located in tiny, irregular cavities of trabecular bone. Determination of absorbed fractions (AFs) of energy or absorbed dose in the AM and the BE represent one of the major challenges of dosimetry. Recently, at the Department of Nuclear Energy at the Federal University of Pernambuco, a skeletal dosimetry method based on µCT images of trabecular bone introduced into the spongiosa voxels of human phantoms has been developed and applied mainly to external exposure to photons. This study uses the same method to calculate AFs of energy and S-values (absorbed dose per unit activity) for electron-emitting radionuclides known to concentrate in skeletal tissues. The modelling of the skeletal tissue regions follows ICRP110, which defines the BE as a 50 µm thick sub-region of marrow next to the bone surfaces. The paper presents mono-energetic AFs for the AM and the BE for eight different skeletal regions for electron source energies between 1 keV and 10 MeV. The S-values are given for the beta emitters 14C, 59Fe, 131I, 89Sr, 32P and 90Y. Comparisons with results from other investigations showed good agreement provided that differences between methodologies and trabecular bone volume fractions were properly taken into account. Additionally, a comparison was made between specific AFs of energy in the BE calculated for the actual 50 µm endosteum and the previously recommended 10 µm endosteum. The increase in endosteum thickness leads to a decrease of the endosteum absorbed dose by up to 3.7 fold when bone is the source region, while absorbed dose increases by ~20% when the beta emitters are in marrow.

  8. Specific ultra-violet absorbance as an indicator measurement of merucry sources in an Adirondack River basin

    USGS Publications Warehouse

    Burns, Douglas A.; Aiken, George R.; Bradley, Paul M.; Journey, Celeste A.; Schelker, Jakob

    2013-01-01

    The Adirondack region of New York has been identified as a hot spot where high methylmercury concentrations are found in surface waters and biota, yet mercury (Hg) concentrations vary widely in this region. We collected stream and groundwater samples for Hg and organic carbon analyses across the upper Hudson River, a 493 km2 basin in the central Adirondacks to evaluate and model the sources of variation in filtered total Hg (FTHg) concentrations. Variability in FTHg concentrations during the growing seasons (May-Oct) of 2007-2009 in Fishing Brook, a 66-km2 sub-basin, was better explained by specific ultra-violet absorbance at 254 nm (SUVA254), a measure of organic carbon aromaticity, than by dissolved organic carbon (DOC) concentrations, a commonly used Hg indicator. SUVA254 was a stronger predictor of FTHg concentrations during the growing season than during the dormant season. Multiple linear regression models that included SUVA254 values and DOC concentrations could explain 75 % of the variation in FTHg concentrations on an annual basis and 84 % during the growing season. A multiple linear regression landscape modeling approach applied to 27 synoptic sites across the upper Hudson basin found that higher SUVA254 values are associated with gentler slopes, and greater riparian area, and lower SUVA254 values are associated with an increasing influence of open water. We hypothesize that the strong Hg?SUVA254 relation in this basin reflects distinct patterns of FTHg and SUVA254 that are characteristic of source areas that control the mobilization of Hg to surface waters, and that the seasonal influence of these source areas varies in this heterogeneous basin landscape.

  9. Cultural Values Predicting Acculturation Orientations: Operationalizing a Quantitative Measure

    ERIC Educational Resources Information Center

    Ehala, Martin

    2012-01-01

    This article proposes that acculturation orientations are related to two sets of cultural values: utilitarianism (Ut) and traditionalism (Tr). While utilitarian values enhance assimilation, traditional values support language and identity maintenance. It is proposed that the propensity to either end of this value opposition can be measured by an…

  10. Quantitative angle-resolved small-spot reflectance measurements on plasmonic perfect absorbers: impedance matching and disorder effects.

    PubMed

    Tittl, Andreas; Harats, Moshe G; Walter, Ramon; Yin, Xinghui; Schäferling, Martin; Liu, Na; Rapaport, Ronen; Giessen, Harald

    2014-10-28

    Plasmonic devices with absorbance close to unity have emerged as essential building blocks for a multitude of technological applications ranging from trace gas detection to infrared imaging. A crucial requirement for such elements is the angle independence of the absorptive performance. In this work, we develop theoretically and verify experimentally a quantitative model for the angular behavior of plasmonic perfect absorber structures based on an optical impedance matching picture. To achieve this, we utilize a simple and elegant k-space measurement technique to record quantitative angle-resolved reflectance measurements on various perfect absorber structures. Particularly, this method allows quantitative reflectance measurements on samples where only small areas have been nanostructured, for example, by electron-beam lithography. Combining these results with extensive numerical modeling, we find that matching of both the real and imaginary parts of the optical impedance is crucial to obtain perfect absorption over a large angular range. Furthermore, we successfully apply our model to the angular dispersion of perfect absorber geometries with disordered plasmonic elements as a favorable alternative to current array-based designs. PMID:25251075

  11. Differences among Monte Carlo codes in the calculations of voxel S values for radionuclide targeted therapy and analysis of their impact on absorbed dose evaluations

    SciTech Connect

    Pacilio, M.; Lanconelli, N.; Lo Meo, S.; Betti, M.; Montani, L.; Torres Aroche, L. A.; Coca Perez, M. A.

    2009-05-15

    Several updated Monte Carlo (MC) codes are available to perform calculations of voxel S values for radionuclide targeted therapy. The aim of this work is to analyze the differences in the calculations obtained by different MC codes and their impact on absorbed dose evaluations performed by voxel dosimetry. Voxel S values for monoenergetic sources (electrons and photons) and different radionuclides ({sup 90}Y, {sup 131}I, and {sup 188}Re) were calculated. Simulations were performed in soft tissue. Three general-purpose MC codes were employed for simulating radiation transport: MCNP4C, EGSnrc, and GEANT4. The data published by the MIRD Committee in Pamphlet No. 17, obtained with the EGS4 MC code, were also included in the comparisons. The impact of the differences (in terms of voxel S values) among the MC codes was also studied by convolution calculations of the absorbed dose in a volume of interest. For uniform activity distribution of a given radionuclide, dose calculations were performed on spherical and elliptical volumes, varying the mass from 1 to 500 g. For simulations with monochromatic sources, differences for self-irradiation voxel S values were mostly confined within 10% for both photons and electrons, but with electron energy less than 500 keV, the voxel S values referred to the first neighbor voxels showed large differences (up to 130%, with respect to EGSnrc) among the updated MC codes. For radionuclide simulations, noticeable differences arose in voxel S values, especially in the bremsstrahlung tails, or when a high contribution from electrons with energy of less than 500 keV is involved. In particular, for {sup 90}Y the updated codes showed a remarkable divergence in the bremsstrahlung region (up to about 90% in terms of voxel S values) with respect to the EGS4 code. Further, variations were observed up to about 30%, for small source-target voxel distances, when low-energy electrons cover an important part of the emission spectrum of the radionuclide

  12. Diversifying natural resources value measurements: The Trinity River study

    USGS Publications Warehouse

    Taylor, J.G.; Douglas, A.J.

    1999-01-01

    An interdisciplinary team set out to establish the economic and social values of the Trinity River in northern California. This information was intended to support the Secretary of the Interior's decision on allocation of Trinity River flows. This team set out to measure the values of Trinity River flows, fishery resources, and recreation amenities in several different ways. A survey was mailed to users of the Trinity River. This single instrument included economic measures (willingness-to-pay and costs incurred in visiting) and social-psychological measures (importance, satisfaction, and water allocation preferences). A closely related survey measured several of these same values among west coast regional households. The results of these surveys were compiled, and the measured economic and social values were compared. We found that integrating economic and social value information provides a greater depth of understanding of the resource's value. In addition, this integration provides a more in-depth understanding through the quantitative and qualitative results that emerge.

  13. MEASUREMENT OF MICROWAVE RADIATION ABSORBED BY BIOLOGICAL SYSTEMS, 2, ANALYSIS BY DEWAR-FLASK CALORIMETRY

    EPA Science Inventory

    Free-field power density has long been used as an index of energy dosing in studies of biological effects of microwave radiation. However, this method of quantifying dose can lead to considerable error if it is used as an index of the rate of energy actually being absorbed by a s...

  14. Roof Integrated Solar Absorbers: The Measured Performance of ''Invisible'' Solar Collectors: Preprint

    SciTech Connect

    Colon, C. J.; Merrigan, T.

    2001-10-19

    The Florida Solar Energy Center (FSEC), with the support of the National Renewable Energy Laboratory, has investigated the thermal performance of solar absorbers that are an integral, yet indistinguishable, part of a building's roof. The first roof-integrated solar absorber (RISA) system was retrofitted into FSEC's Flexible Roof Facility in Cocoa, Florida, in September 1998. This ''proof-of-concept'' system uses the asphalt shingle roof surface and the plywood decking under the shingles as an unglazed solar absorber. Data was gathered for a one-year period on the system performance. In Phase 2, two more RISA prototypes were constructed and submitted for testing. The first used the asphalt shingles on the roof surface with the tubing mounted on the underside of the plywood decking. The second prototype used metal roofing panels over a plywood substrate and placed the polymer tubing between the plywood decking and the metal roofing. This paper takes a first look at the thermal performance results for the ''invisible'' solar absorbers that use the actual roof surface of a building for solar heat collection.

  15. Using optoacoustic imaging for measuring the temperature dependence of Grüneisen parameter in optically absorbing solutions

    PubMed Central

    Petrova, Elena; Ermilov, Sergey; Su, Richard; Nadvoretskiy, Vyacheslav; Conjusteau, André; Oraevsky, Alexander

    2013-01-01

    Grüneisen parameter is a key temperature-dependent physical characteristic responsible for thermoelastic efficiency of materials. We propose a new methodology for accurate measurements of temperature dependence of Grüneisen parameter in optically absorbing solutions. We use two-dimensional optoacoustic (OA) imaging to improve accuracy of measurements. Our approach eliminates contribution of local optical fluence and absorbance. To validate the proposed methodology, we studied temperature dependence of aqueous cupric sulfate solutions in the range from 22 to 4°C. Our results for the most diluted salt perfectly matched known temperature dependence for the Grüneisen parameter of water. We also found that Grüneisen-temperature relationship for cupric sulfate exhibits linear trend with respect to the concentration. In addition to accurate measurements of Grüneisen changes with temperature, the developed technique provides a basis for future high precision OA temperature monitoring in live tissues. PMID:24150350

  16. Axiological Measurement of Human Value Factors in Mental Processes.

    ERIC Educational Resources Information Center

    Bierschenk, Bernhard; Mattsson, Jan

    Modern behavioral research focuses on the possibility of a direct measurement of value preferences, which are conceived as important causal variables of behavior. A method and procedure for the measurement and representation of human value factors is presented. The thesis was studied that valuation results from an active inquiring agent whose…

  17. Measurement Invariance of Expectancy-Value Questionnaire in Physical Education

    ERIC Educational Resources Information Center

    Zhu, Xihe; Sun, Haichun; Chen, Ang; Ennis, Catherine

    2012-01-01

    Expectancy-Value Questionnaire (EVQ) measures student expectancy beliefs and task values of the domain content (Eccles & Wigfield, 1995). In this study the authors examine measurement invariance of EVQ in the domain of physical education between elementary and middle-school students. Participants included 811 students (3rd-5th grades) from 13…

  18. Influence of extraction solvent on antioxidant capacity value of oleaster measured by ORAC method.

    PubMed

    Yalcin, Gorkem; Sogut, Ozlem

    2014-01-01

    Oxygen radical absorbance capacity (ORAC) is a widely used hydrogen atom transfer-based method which measures the antioxidant capacity of natural products. ORAC values of oleaster (Elaeagnus angustifolia L.), which was extracted with ethanol/acetone (7:3, v/v), ethanol/water (1:1, v/v) and methanol/water (1:1, v/v) in order to evaluate the effects of solvent type on antioxidant capacity, were examined. In general, results revealed that ethanol/water extracts exhibited better antioxidant capacity values. Furthermore, results obtained by using ORAC-eosin y (ORAC-EY), one of the widely used derivative of fluorescein (FL), as a fluorescent probe were compared with those obtained by using ORAC-FL. According to the results, ORAC-EY values were found to be compatible with ORAC-FL values. PMID:24783990

  19. Developing a Measure of Value in Health Care.

    PubMed

    Ken Lee, K H; Matthew Austin, J; Pronovost, Peter J

    2016-06-01

    There is broad support to pay for value, rather than volume, for health care in the United States. Despite the support, practical approaches for measuring value remain elusive. Value is commonly defined as quality divided by costs, where quality reflects patient outcomes and costs are the total costs for providing care, whether these be costs related to an episode, a diagnosis, or per capita. Academicians have proposed a conceptual approach to measure value, in which we measure outcomes important to patients and costs using time-driven activity-based costing. This approach is conceptually sound, but has significant practical challenges. In our commentary, we describe how health care can use existing quality measures and cost accounting data to measure value. Although not perfect, we believe this approach is practical, valid, and scalable and can establish the foundation for future work in this area. PMID:27325323

  20. Measuring industrial energy efficiency: Physical volume versus economic value

    SciTech Connect

    Freeman, S.L.; Niefer, M.J.; Roop, J.M.

    1996-12-01

    This report examines several different measures of industrial output for use in constructing estimates of industrial energy efficiency and discusses some reasons for differences between the measures. Estimates of volume-based measures of output, as well as 3 value-based measures of output (value of production, value of shipments, and value added), are evaluated for 15 separate 4-digit industries. Volatility, simple growth rate, and trend growth rate estimates are made for each industry and each measure of output. Correlations are made between the volume- and value-based measures of output. Historical energy use data are collected for 5 of the industries for making energy- intensity estimates. Growth rates in energy use, energy intensity, and correlations between volume- and value-based measures of energy intensity are computed. There is large variability in growth trend estimates both long term and from year to year. While there is a high correlation between volume- and value-based measures of output for a few industries, typically the correlation is low, and this is exacerbated for estimates of energy intensity. Analysis revealed reasons for these low correlations. It appears that substantial work must be done before reliable measures of trends in the energy efficiency of industry can be accurately characterized.

  1. All-fiber wavelength-tunable picosecond nonlinear reflectivity measurement setup for characterization of semiconductor saturable absorber mirrors

    NASA Astrophysics Data System (ADS)

    Viskontas, K.; Rusteika, N.

    2016-09-01

    Semiconductor saturable absorber mirror (SESAM) is the key component for many passively mode-locked ultrafast laser sources. Particular set of nonlinear parameters is required to achieve self-starting mode-locking or avoid undesirable q-switch mode-locking for the ultra-short pulse laser. In this paper, we introduce a novel all-fiber wavelength-tunable picosecond pulse duration setup for the measurement of nonlinear properties of saturable absorber mirrors at around 1 μm center wavelength. The main advantage of an all-fiber configuration is the simplicity of measuring the fiber-integrated or fiber-pigtailed saturable absorbers. A tunable picosecond fiber laser enables to investigate the nonlinear parameters at different wavelengths in ultrafast regime. To verify the capability of the setup, nonlinear parameters for different SESAMs with low and high modulation depth were measured. In the operating wavelength range 1020-1074 nm, <1% absolute nonlinear reflectivity accuracy was demonstrated. Achieved fluence range was from 100 nJ/cm2 to 2 mJ/cm2 with corresponding intensity from 10 kW/cm2 to 300 MW/cm2.

  2. [Measurement of terrestrial ecosystem service value in China].

    PubMed

    He, Hao; Pan, Yaozhong; Zhu, Wenquan; Liu, Xulong; Zhang, Qing; Zhu, Xiufang

    2005-06-01

    With the measurement of net primary productivity and vegetation coverage fraction based on remote sensing data,the terrestrial ecosystem service value of China in 2000 was quantitatively estimated as 9.17 x 10(12) yuan (RMB). The spatial distribution of the ecological service value showed a decreasing trend from southeast China to northwest China, which was consistent with the regional distribution of vegetation types. The service value varied with different vegetations, e. g., forests had the highest service value of 18 789 yuan x hm(-2), accounting for 40.80% of the total terrestrial ecosystem service value, and bushes and farmlands had a higher service value of 13 789 yuan x hm(-2) and 13054 yuan x hm(-2), which was 10.79% and 24.23% of total value, respectively. The service value was also varied with different ecosystem functions, i.e., gas regulation contributed the highest value of 45.16% to the total service value, and the contribution of soil conservation and water conservation was 28.83% and 14.44%, respectively. The integrated approach coupling ecology and remote sensing data provided a new method to measure the ecological service value, which could estimate the value objectively and spatial-explicitly. However, some uncertainties still existed in this approach, which should be improved in the future studies. PMID:16180767

  3. Two-Valued Probability Measure on the Pontryagin Space

    NASA Astrophysics Data System (ADS)

    Matvejchuk, Marjan; Utkina, Elena

    2015-12-01

    The well known Kochen-Specker's theorem is devoted to the problem of hidden variables in quantum mechanics. The Kochen-Specker theorem says: There is no two-valued probability measure on the real Hilbert space of dimension three. In the paper we present an analogy of Kochen-Specker's theorem in Pontryagin space: A Pontryagin spase H of dimension greater than or equal to three has a two-valued probability measure if and only if H has indefinite rank one: in which case, any such two-valued probability measure on H is unique.

  4. The Valued Living Questionnaire for Alcohol Use: Measuring value-behavior discrepancy in college student drinking.

    PubMed

    Miller, Mary Beth; Meier, Ellen; Lombardi, Nathaniel; Leavens, Eleanor L; Grant, DeMond M; Leffingwell, Thad R

    2016-09-01

    Developing discrepancy between one's values and behaviors is theoretically important in motivating change; however, existing studies lack a validated measure of value-behavior discrepancy for alcohol misuse. The current studies aimed to modify Wilson & DuFrene (2008) Valued Living Questionnaire (VLQ) to assess consistency of alcohol use with important values. In Study 1, the initial factor structure and test-retest reliability of the VLQ for Alcohol Use (VLQ-A) was tested in a sample of college students who regularly drink alcohol (N = 150). Results guided modifications to the measure. In Study 2, the revised measure's factor structure and predictive validity were tested with a second sample of college students who drink alcohol (N = 222). In both studies, exploratory factor analysis supported a unidimensional factor structure. Perceived discrepancy between alcohol use and important values predicted greater readiness to change, while perceived consistency between alcohol use and important values predicted more frequent heavy episodic drinking. Certain values were more useful in predicting outcomes than others. Alcohol use (heavy vs. moderate drinking) did not moderate outcomes. The VLQ-A is a brief and reliable self-report measure of perceived discrepancy between drinking behaviors and important values that may increase readiness to change. Future research examining the generalizability of findings to various samples and the efficacy of the VLQ-A as a supplement to brief interventions is warranted. (PsycINFO Database Record PMID:27537000

  5. Determination of the quantum dot band gap dependence on particle size from optical absorbance and transmission electron microscopy measurements.

    PubMed

    Segets, Doris; Lucas, J Matthew; Klupp Taylor, Robin N; Scheele, Marcus; Zheng, Haimei; Alivisatos, A Paul; Peukert, Wolfgang

    2012-10-23

    This work addresses the determination of arbitrarily shaped particle size distributions (PSDs) from PbS and PbSe quantum dot (QD) optical absorbance spectra in order to arrive at a relationship between band gap energy and particle size over a large size range. Using a modified algorithm which was previously developed for ZnO, we take only bulk absorption data from the literature and match the PSDs derived from QD absorbance spectra with those from transmission electron microscopical (TEM) image analysis in order to arrive at the functional dependence of the band gap on particle size. Additional samples sized solely from their absorbance spectra with our algorithm show excellent agreement with TEM results. We investigate the influence of parameters of the TEM image analysis such as threshold value on the final result. The band gap versus size relationship developed from analysis of just two samples lies well within the bounds of a number of published data sets. We believe that our methodology provides an attractive shortcut for the study of various novel quantum-confined direct band gap semiconductor systems as it permits the band gap energies of a broad size range of QDs to be probed with relatively few synthetic experiments and without quantum mechanical simulations. PMID:22984808

  6. Accurate spectral response measurements of a complementary absorbing organic tandem cell with fill factor exceeding the subcells

    SciTech Connect

    Cheyns, David; Kim, Minjae; Verreet, Bregt; Rand, Barry P.

    2014-03-03

    Single heterojunction organic photovoltaic cells based on co-evaporated donor–acceptor layers with power conversion efficiencies (η) above 5.5% are demonstrated, using either high (1.8 eV) or low (1.4 eV) optical gap materials. The high energy absorbing cell utilizes a high fullerene-C{sub 70} content, in combination with a high mobility amorphous donor, while the low energy absorbing cell consists of a donor–acceptor molecule paired with C{sub 60} as the acceptor. The integration of the two cells in an optimized tandem configuration leads to η =7.2%, verified by external quantum efficiency measurements of the subcells. Notably, the fill-factor of the tandem stack is higher than either one of the sub-cells.

  7. Colloid osmotic pressure: its measurement and clinical value.

    PubMed Central

    Morissette, M. P.

    1977-01-01

    Plasma colloid osmotic pressure (COP) is an important determinant in the appearance of edema. The development of a simple technique for COP measurement, based on an electronic pressure transducer and a semipermeable membrane system, has led to an appreciation of the value of COP determinations in clinical practice. In a steady state the measured COP replicates the value computed from serum proteins. In pathologic sera a derived value is unreliable. The normal human plasma COP averages 25.4 mm Hg. This value tends to decrease with age, is lower in females and is also lower in subjects at bed rest. As a clinical tool COP measurement represents an unduplicated contribution to the differential diagnosis of pulmonary edema. In critically ill patients COP measurement represents a reliable predictor of survival. PMID:851930

  8. Measuring Social Studies Achievement: A Matter of Values.

    ERIC Educational Resources Information Center

    Elliot, Richard J.

    Questions as to whether measurement can provide a universally applicable set of criteria for making value judgments in the social sciences are raised. Four assumptions about education, experience, reality, and value formation were identified to provide a fuller reference point for social science educators when they are viewing current standardized…

  9. Mechanism of the typical relaxation process at low frequency based on dielectric measurements of water absorbed in porous titanium dioxide

    NASA Astrophysics Data System (ADS)

    Gao, Xin; Wang, Qiang; Sun, Gang; Li, Chenxi; Hu, Lin

    2016-02-01

    Dielectric spectroscopy is a valuable tool in physics, chemistry, biophysics, and materials science. However, there is still an argument about the typical relaxation process at low frequency, which is always masked by electrode polarization. Low-frequency dielectric measurements of water absorbed in porous titanium dioxide have been performed. The experimental results show that typical polarization at low frequency is caused by space-charge polarization. A model is proposed to explain the experimental results, which indicates that the electric field in the sample is close to 0. An effective circuit is given, and the calculation gives similar dielectric spectra to those measured in experiments, which confirms the physical model.

  10. Application of high-resolution spectral absorbance measurements to determine dissolved organic carbon concentration in remote areas

    NASA Astrophysics Data System (ADS)

    Avagyan, Armine; Runkle, Benjamin R. K.; Kutzbach, Lars

    2014-09-01

    Accurate quantification of dissolved organic carbon (DOC) in surface and soil pore waters is crucial for understanding changes in water resources under the influence of climate and land use changes. Sampling and laboratory analysis of DOC content at a sufficient temporal frequency are especially difficult to achieve for natural DOC sources like the extensive boreal and arctic mire landscapes due to their remoteness. Therefore, the goals of this paper are (1) to investigate the performance of a portable, high-resolution ultraviolet-visible light spectroscopic method for determining the DOC content of surface and soil pore water samples from a boreal mire complex and (2) to compare the spectroscopic method with other DOC measurement techniques, e.g., the wet heated persulfate oxidation method and a laboratory, expulsion-based spectrophotometric method and (3) to assess different multivariate models that relate absorbance measurements with DOC contents. The study indicates that high-resolution spectroscopic measurements provide a simple, robust and non-destructive method for measuring DOC content. These measurements are of short duration (<1 min) and the sample analysis is portable, rendering this method particularly advantageous for in situ investigations at remote field locations. The study also demonstrates that if absorbances at specific wavelengths are used as proxies for DOC concentration, it is recommended to create site-specific calibration models that include more than one wavelength to achieve the optimal accuracy of the proxy-based DOC quantification.

  11. Evaluating a novel application of optical fibre evanescent field absorbance: rapid measurement of red colour in winegrape homogenates

    NASA Astrophysics Data System (ADS)

    Lye, Peter G.; Bradbury, Ronald; Lamb, David W.

    Silica optical fibres were used to measure colour (mg anthocyanin/g fresh berry weight) in samples of red wine grape homogenates via optical Fibre Evanescent Field Absorbance (FEFA). Colour measurements from 126 samples of grape homogenate were compared against the standard industry spectrophotometric reference method that involves chemical extraction and subsequent optical absorption measurements of clarified samples at 520 nm. FEFA absorbance on homogenates at 520 nm (FEFA520h) was correlated with the industry reference method measurements of colour (R2 = 0.46, n = 126). Using a simple regression equation colour could be predicted with a standard error of cross-validation (SECV) of 0.21 mg/g, with a range of 0.6 to 2.2 mg anthocyanin/g and a standard deviation of 0.33 mg/g. With a Ratio of Performance Deviation (RPD) of 1.6, the technique when utilizing only a single detection wavelength, is not robust enough to apply in a diagnostic sense, however the results do demonstrate the potential of the FEFA method as a fast and low-cost assay of colour in homogenized samples.

  12. Measurement Theory in Deutsch's Algorithm Based on the Truth Values

    NASA Astrophysics Data System (ADS)

    Nagata, Koji; Nakamura, Tadao

    2016-08-01

    We propose a new measurement theory, in qubits handling, based on the truth values, i.e., the truth T (1) for true and the falsity F (0) for false. The results of measurement are either 0 or 1. To implement Deutsch's algorithm, we need both observability and controllability of a quantum state. The new measurement theory can satisfy these two. Especially, we systematically describe our assertion based on more mathematical analysis using raw data in a thoughtful experiment.

  13. Redox potential - field measurements - meassured vs. expected values

    NASA Astrophysics Data System (ADS)

    Stavělová, Monika; Kovář, Martin

    2016-04-01

    Oxidation and reduction (redox) potential is an important and theoretically very well defined parameter and can be calculated accurately. Its value is determinative for management of many electrochemical processes, chemical redox technologies as well as biotechnologies. To measure the redox value that would correspond with the accuracy level of theoretical calculations in field or operational conditions is however nearly impossible. Redox is in practice measured using combined argentochloride electrode with subsequent value conversion to standard hydrogen electrode (EH). Argentochloride electrode does not allow for precise calibration. Prior to the measurement the accuracy of measurement of particular electrode can only be verified in comparative/control solution with value corresponding with oxic conditions (25°C: +220 mV argentochloride electrode, i.e.. +427 mV after conversion to EH). A commercial product of stabile comparative solution for anoxic conditions is not available and therefore not used in every day practice - accuracy of negative redox is not verified. In this presentation results of two tests will be presented: a) monitoring during dynamic groundwater sampling from eight monitoring wells at a site contaminated by chlorinated ethenes (i.e. post-oxic to anoxic conditions) and b) laboratory test of groundwater contaminated by arsenic from two sites during reaction with highly oxidized compounds of iron (ferrates) - i.e. strongly oxic conditions. In both tests a simultaneous measurement by four argentochloride electrodes was implemented - all four electrodes were prior to the test maintained expertly. The redox values of testing electrodes in a comparative solution varied by max. 6 mV. The redox values measured by four electrodes in both anoxic and oxic variant varied by tens to a hundred mV, while with growing time of test the variance of measured redox values increased in both oxic and anoxic variant. Therefore the interpretation of measured redox

  14. Mushroom plasmonic metamaterial infrared absorbers

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Hata, Hisatoshi; Uetsuki, Mitsuharu; Misaki, Koji; Kimata, Masafumi

    2015-01-01

    There has been a considerable amount of interest in the development of various types of electromagnetic wave absorbers for use in different wavelength ranges. In particular, infrared (IR) absorbers with wavelength selectivity can be applied to advanced uncooled IR sensors, which would be capable of identifying objects through their radiation spectrum. In the present study, mushroom plasmonic metamaterial absorbers (MPMAs) for the IR wavelength region were designed and fabricated. The MPMAs consist of a periodic array of thin metal micropatches connected to a thin metal plate with narrow silicon (Si) posts. A Si post height of 200 nm was achieved by isotropic XeF2 etching of a thin Si layer sandwiched between metal plates. This fabrication procedure is relatively simple and is consistent with complementary metal oxide semiconductor technology. The absorption spectra of the fabricated MPMAs were experimentally measured. In addition, theoretical calculations of their absorption properties were conducted using rigorous coupled wave analysis. Both the calculated and measured absorbance results demonstrated that these MPMAs can realize strong selective absorption at wavelengths beyond the period of the array by varying the micropatch width. Absorbance values greater than 90% were achieved. Dual- or single-mode absorption can also be selected by varying the width of the Si posts. Pixel structures using such MPMAs could be used as high responsivity, high resolution and fast uncooled IR sensors.

  15. Mushroom plasmonic metamaterial infrared absorbers

    SciTech Connect

    Ogawa, Shinpei Fujisawa, Daisuke; Hata, Hisatoshi; Uetsuki, Mitsuharu; Misaki, Koji; Kimata, Masafumi

    2015-01-26

    There has been a considerable amount of interest in the development of various types of electromagnetic wave absorbers for use in different wavelength ranges. In particular, infrared (IR) absorbers with wavelength selectivity can be applied to advanced uncooled IR sensors, which would be capable of identifying objects through their radiation spectrum. In the present study, mushroom plasmonic metamaterial absorbers (MPMAs) for the IR wavelength region were designed and fabricated. The MPMAs consist of a periodic array of thin metal micropatches connected to a thin metal plate with narrow silicon (Si) posts. A Si post height of 200 nm was achieved by isotropic XeF{sub 2} etching of a thin Si layer sandwiched between metal plates. This fabrication procedure is relatively simple and is consistent with complementary metal oxide semiconductor technology. The absorption spectra of the fabricated MPMAs were experimentally measured. In addition, theoretical calculations of their absorption properties were conducted using rigorous coupled wave analysis. Both the calculated and measured absorbance results demonstrated that these MPMAs can realize strong selective absorption at wavelengths beyond the period of the array by varying the micropatch width. Absorbance values greater than 90% were achieved. Dual- or single-mode absorption can also be selected by varying the width of the Si posts. Pixel structures using such MPMAs could be used as high responsivity, high resolution and fast uncooled IR sensors.

  16. Weak-value Metrology and Shot-Noise Limited Measurements

    NASA Astrophysics Data System (ADS)

    Viza, Gerardo Ivan

    This thesis contains a subset of the research in which I have participated in during my studies at the University of Rochester. It contains three projects and one overarching theme of weak-value metrology. We start with chapter 1 where we cover the historical background leading up to quantum optics, which we use for precision metrology. We also introduce the weak-value formulation and give examples of metrological implementations for parameter estimation. Chapter 2 introduces two experiments to measure a longitudinal velocity and a transverse momentum kick. We show that weak-value based techniques are shot-noise limited because we saturate the Cramer-Rao bound for the estimator used, and efficient because we experimentally demonstrate there is virtually no loss of Fisher information of the parameter of interest from the discarded events. In Chapter 3 we present a comparison of two experiments that measure a beam deflection. One experiment is a weak-value based technique, while the other is the standard focusing technique. We set up the two experiments in the presence of simulated technical noise sources and show how the weak-value based technique out performs the standard technique in both visibility and in deviation of the transverse momentum kick. Chapter 4 contains work of the exploration of concatenated postselection for weak-value amplification. We demonstrate an optimization and conditions where postselecting on two degrees of freedom can be beneficial to enhance the weak-value amplification.

  17. Heisenberg's uncertainty principle for simultaneous measurement of positive-operator-valued measures

    NASA Astrophysics Data System (ADS)

    Miyadera, Takayuki; Imai, Hideki

    2008-11-01

    A limitation on simultaneous measurement of two arbitrary positive-operator-valued measures is discussed. In general, simultaneous measurement of two noncommutative observables is only approximately possible. Following Werner’s formulation, we introduce a distance between observables to quantify an accuracy of measurement. We derive an inequality that relates the achievable accuracy with noncommutativity between two observables. As a byproduct a necessary condition for two positive-operator-valued measures to be simultaneously measurable is obtained.

  18. Laser heating of an absorbing and conducting media applied to laser flash property measurements

    SciTech Connect

    Gritzo, L.A.; Anderson, E.E.

    1993-12-31

    The laser flash technique is widely used for determining the thermal diffusivity of a sample. In this work, the temperature distribution throughout the sample is investigated, identifying localized, highly-heated regions near the front surface of the sample as a function of: (1) pulse duration, (2) incident beam uniformity, and (3) sample opacity. These high-temperature regions result in an increase in the uncertainty due to temperature-dependent properties, an increase in the heat loss from the sample, and an increased risk of sample damage. The temperature within a semi-transparent media is also investigated in order to establish a regime for which the media can reasonably be considered as opaque. This analysis illustrates that, for same total energy deposition, treatment of the incident energy as a continuous heat source, as opposed to an infinitesimal pulse of energy, results in a factor of 2 increase in the front surface temperature during heating. Also, for the same total energy deposition and approximate beam size, use of a Gaussian intensity distribution increases the front surface temperature during heating by more than a factor of 2 as compared to the use of a uniform temperature distribution. By analyzing the front surface temperature of an absorbing and conducting semi-transparent sample subjected to a Gaussian intensity distribution, it is concluded that the media can be treated as opaque, (i.e. the energy can be applied as a boundary condition) for {var_epsilon} = kd > 50, where k is the extinction coefficient and d is the beam diameter. For materials with a sufficiently small absorption coefficient and thermal diffusivity, a closed-form solution suitable for design use is presented for the front-surface temperature at a location coincident with the beam centerline.

  19. Using Value-Added Measures of Teacher Quality. Brief 9

    ERIC Educational Resources Information Center

    Hanushek, Eric A.; Rivkin, Steven G.

    2010-01-01

    Extensive education research on the contribution of teachers to student achievement produces two generally accepted results. First, teacher quality varies substantially as measured by the value added to student achievement or future academic attainment or earnings. Second, variables often used to determine entry into the profession and…

  20. Measuring the strategic value of information technology investments

    SciTech Connect

    Conrad, K.W.

    1994-08-01

    Value is often perceived differently by the proponents of new information technologies and those who allocate resources and define priorities. Such differences often become a roadblock to meeting true business needs. Project justifications regularly rely on calculated cost savings, which rarely measure the full benefit of new technologies. In fact, if cost savings provide a complete picture, then the organization is probably just automating routine clerical operations and has abandoned efforts that would provide significant strategic value. Strategic value is not limited to financial calculations, but includes quality, time and risk criteria. This paper describes approaches for measuring strategic value that can provide organizations with proven techniques to improve performance, reengineer processes, benchmark performance against other suppliers, identify outsourcing opportunities, or defend themselves from pressures to outsource. Many organizations respond to tightening budgets by cutting overhead. These measurement approaches can demonstrate how overhead is critical to organizational effectiveness and how cost savings can be found, instead, by measurably improving performance throughout the organization. Finally, the paper describes efforts underway within the Department of Energy and at the Hanford Site to implement the approaches described in this paper.

  1. Measuring and Communicating the Value Created by an Organization

    ERIC Educational Resources Information Center

    Sherman, W. Richard

    2010-01-01

    This paper offers a different perspective in measuring the value created by an organization. It does so in the context of an undergraduate course in managerial accounting. In order to break down the functional silo approach to problem solving that has become the model of traditional business education, applications of shadow accounting, the…

  2. Valuing Informal Care Experience: Does Choice of Measure Matter?

    ERIC Educational Resources Information Center

    Mentzakis, Emmanouil; McNamee, Paul; Ryan, Mandy; Sutton, Matthew

    2012-01-01

    Well-being equations are often estimated to generate monetary values for non-marketed activities. In such studies, utility is often approximated by either life satisfaction or General Health Questionnaire scores. We estimate and compare monetary valuations of informal care for the first time in the UK employing both measures, using longitudinal…

  3. Social Capital, Value, and Measure: Antonio Negri's Challenge to Capitalism.

    ERIC Educational Resources Information Center

    Day, Ronald E.

    2002-01-01

    Considers one concept in knowledge management, that of social capital, focusing on the problem of measure and value in capitalism, specifically within the period and conditions of post-Fordist production. Discusses the work of Antonio Negri and suggests the importance of knowledge management as a symptom of a turn in political economy. (Author/LRW)

  4. Against Journal Articles for Measuring Value in University Output

    ERIC Educational Resources Information Center

    Mbali, C.

    2010-01-01

    The following lines of arguments against the metrics of journal articles is developed: (1) Textual output should no longer be main valued output; (2) Digitalization enables other ways of advancing knowledge; (3) Measures by journal article favours the disciplines of Natural Science and Engineering (NSE) and moulds other disciplines of Social…

  5. Quantitation of absorbed or deposited materials on a substrate that measures energy deposition

    DOEpatents

    Grant, Patrick G.; Bakajin, Olgica; Vogel, John S.; Bench, Graham

    2005-01-18

    This invention provides a system and method for measuring an energy differential that correlates to quantitative measurement of an amount mass of an applied localized material. Such a system and method remains compatible with other methods of analysis, such as, for example, quantitating the elemental or isotopic content, identifying the material, or using the material in biochemical analysis.

  6. Estimation of absorbed doses from paediatric cone-beam CT scans: MOSFET measurements and Monte Carlo simulations.

    PubMed

    Kim, Sangroh; Yoshizumi, Terry T; Toncheva, Greta; Frush, Donald P; Yin, Fang-Fang

    2010-03-01

    The purpose of this study was to establish a dose estimation tool with Monte Carlo (MC) simulations. A 5-y-old paediatric anthropomorphic phantom was computed tomography (CT) scanned to create a voxelised phantom and used as an input for the abdominal cone-beam CT in a BEAMnrc/EGSnrc MC system. An X-ray tube model of the Varian On-Board Imager((R)) was built in the MC system. To validate the model, the absorbed doses at each organ location for standard-dose and low-dose modes were measured in the physical phantom with MOSFET detectors; effective doses were also calculated. In the results, the MC simulations were comparable to the MOSFET measurements. This voxelised phantom approach could produce a more accurate dose estimation than the stylised phantom method. This model can be easily applied to multi-detector CT dosimetry. PMID:19889800

  7. Agentic and communal values: their scope and measurement.

    PubMed

    Trapnell, Paul D; Paulhus, Delroy L

    2012-01-01

    Agency is the meta-concept associated with self-advancement in social hierarchies; communion is the partner concept associated with maintenance of positive relationships. Despite the wealth of data documenting the conceptual utility of agency and communion (A & C) as superordinate metaconcepts, no direct measures of global A & C value dimensions are currently available. The first part of this article presents structural analyses of data from 4 diverse data sets (3 archival and 1 new): Each included a broad inventory of values or life goals. All 4 data sets revealed higher order A & C dimensions that were either apparent or implicit. The second part details the development of the ACV, a 24-item questionnaire measuring global A and C values, and documents its psychometric properties. Four studies support their joint construct validity by positioning the value measures within a nomological network of interpersonal traits, self-favorability biases, ideology dimensions, gender, socio-sexuality, and religious attitudes. Potential applications of the new instrument are discussed. PMID:22176265

  8. Ultrasensitive Beam Deflection Measurement via Interferometric Weak Value Amplification

    SciTech Connect

    Dixon, P. Ben; Starling, David J.; Jordan, Andrew N.; Howell, John C.

    2009-05-01

    We report on the use of an interferometric weak value technique to amplify very small transverse deflections of an optical beam. By entangling the beam's transverse degrees of freedom with the which-path states of a Sagnac interferometer, it is possible to realize an optical amplifier for polarization independent deflections. The theory for the interferometric weak value amplification method is presented along with the experimental results, which are in good agreement. Of particular interest, we measured the angular deflection of a mirror down to 400{+-}200 frad and the linear travel of a piezo actuator down to 14{+-}7 fm.

  9. Notes on the Measurement of pH Values

    SciTech Connect

    Carranza, R M; Rebak, R B

    2005-05-05

    The original definition of pH is: pH = -log a{sub H}. Where a{sub H} is the (relative) hydrogen ion activity. However, a single ion activity cannot be measured. Activities of individual ionic species are necessarily conventional. The pH number, of course, has in itself little absolute significance. As the negative of the logarithm of a product of a concentration (c or m) and an activity coefficient (y or {gamma}), it acquires its magnitude from the numerical scale adopted for the latter. Experimental pH measurements are nonetheless widely applied to the determination of thermodynamic equilibrium data such as pK values, on the assumption that they represent -log a{sub H} (or paH). The single ion activity coefficient approaches unity as the ionic strength goes to zero, so that activity becomes m or c and paH becomes pmH or pcH. pH is therefore defined operationally in terms of the operation or method used to measure it, that is, by means of a cell called an operational cell. The cell is standardized by solutions of assigned pH value (Reference Value pH Standard, Primary pH Standards and Operational Standards). Such standard reference solutions are buffer solutions whose pH values are assigned from measurements on cells with or without liquid junction. It must be emphasized that the definition of pH scale is quite different from the measurement of pH with glass-reference electrode-pH meter assemblies, where several standards are used in order to take into account possible deficiencies in the electrode and meter performance.

  10. Development and validation of a measure of food choice values.

    PubMed

    Lyerly, Jordan E; Reeve, Charlie L

    2015-06-01

    Food choice values (FCVs) are factors that individuals consider when deciding which foods to purchase and/or consume. Given the potentially important implications for health, it is critical for researchers to have access to a validated measure of FCV. Though there is an existing measure of FCV, this measure was developed 20 years ago and recent research suggests additional FCVs exist that are not included in this measure. A series of four studies was conducted to develop a new expanded measure of FCV. An eight-factor model of FCV was supported and confirmed. In aggregate, results from the four studies indicate that the measure is content valid, and has internally consistent scales that also demonstrated acceptable temporal stability and convergent validity. In addition, the eight scales of the measures were independent of social desirability, met criteria for measurement invariance across income groups, and predicted dietary intake. The development of this new measure of FCV may be useful for researchers examining FCVs (FCVs) in the future, as well as for use in intervention and prevention efforts targeting dietary choices. PMID:25637871

  11. Measurement of wavelength-dependent extinction to distinguish between absorbing and nonabsorbing aerosol particulates

    NASA Technical Reports Server (NTRS)

    Portscht, R.

    1977-01-01

    Measurements of spectral transmission factors in smoky optical transmission paths reveal a difference between wavelength exponents of the extinction cross section of high absorption capacity and those of low absorption capacity. A theoretical explanation of this behavior is presented. In certain cases, it is possible to obtain data on the absorption index of aerosol particles in the optical path by measuring the spectral decadic extinction coefficient at, at least, two wavelengths. In this manner it is possible, for instance, to distinguish smoke containing soot from water vapor.

  12. On the Singular Value Decomposition of Measured Data

    NASA Astrophysics Data System (ADS)

    Epps, Brenden

    2015-11-01

    Singular value decomposition (SVD) is a well-known mathematical tool that can be used to decompose an ensemble of velocity field data into spatiotemporal modes that may reveal coherent flow structures. The proper orthogonal decomposition (POD) is a special case of the SVD, used when the data are uncorrelated in time (as in a turbulent flow). Although the SVD and POD have been widely used in fluid mechanics, Epps and Techet (2010, ExpFluids 48:355-367) were among the first to consider how experimental error affects the results of the SVD. This talk revisits that paper and provides mathematically-rigorous bounds on the errors in the computed singular values and spatio-temporal mode shapes. Given experimental data with unknown error, a procedure is presented to (i) determine the root mean square measurement error and (ii) determine ``error bars'' for the singular values and vectors.

  13. Measurement of the neutron detection efficiency of a 80% absorber-20% scintillating fibers calorimeter

    NASA Astrophysics Data System (ADS)

    Anelli, M.; Bertolucci, S.; Bini, C.; Branchini, P.; Corradi, G.; Curceanu, C.; De Zorzi, G.; Di Domenico, A.; Di Micco, B.; Ferrari, A.; Fiore, S.; Gauzzi, P.; Giovannella, S.; Happacher, F.; Iliescu, M.; Lucà, A.; Martini, M.; Miscetti, S.; Nguyen, F.; Passeri, A.; Prokofiev, A. V.; Sarra, I.; Sciascia, B.; Sirghi, F.; Tagnani, D.

    2011-01-01

    The neutron detection efficiency of a sampling calorimeter made of 1 mm diameter scintillating fibers embedded in a lead/bismuth structure has been measured at the neutron beam of The Svedberg Laboratory at Uppsala. A significant enhancement of the detection efficiency with respect to a bulk organic scintillator detector with the same thickness is observed.

  14. Uncertainty relations for positive-operator-valued measures

    SciTech Connect

    Massar, Serge

    2007-10-15

    How much unavoidable randomness is generated by a positive-operator-valued measure (POVM)? We address this question using two complementary approaches. First, we study the variance of a real variable associated with the POVM outcomes. In this context we introduce an uncertainty operator which measures how much additional noise is introduced by carrying out a POVM rather than a von Neumann measurement. We illustrate this first approach by studying the variances of joint estimates of {sigma}{sub x} and {sigma}{sub z} for spin-1/2 particles. We show that for unbiased measurements the sum of these variances is lower bounded by 1. In our second approach we study the entropy of the POVM outcomes. In particular, we try to establish lower bounds on the entropy of the POVM outcomes. We illustrate this second approach by examples.

  15. Defining and Computing a Value Based Cyber-Security Measure

    SciTech Connect

    Aissa, Anis Ben; Abercrombie, Robert K; Sheldon, Frederick T; Mili, Ali

    2011-01-01

    In past work, we presented a value based measure of cybersecurity that quantifies the security of a system in concrete terms, specifically, in terms of how much each system stakeholder stands to lose (in dollars per hour of operation) as a result of security threats and system vulnerabilities\\; our metric varies according to the stakes that each stakeholder has in meeting each security requirement. In this paper we discuss the specification and design of a system that collects, updates and maintains all the information that pertains to estimating our cybersecurity measure, and offers stakeholders quantitative means to make security-related decisions.

  16. Defining and Computing a Valued Based Cyber-Security Measure

    SciTech Connect

    Aissa, Anis Ben; Abercrombie, Robert K; Sheldon, Frederick T; Mili, Ali

    2012-01-01

    In earlier work, we presented a value based measure of cybersecurity that quantifies the security of a system in concrete terms, specifically, in terms of how much each system stakeholder stands to lose (in dollars per hour of operation) as a result of security threats and system vulnerabilities; our metric varies according to the stakes that each stakeholder has in meeting each security requirement. In this paper, we discuss the specification and design of a system that collects, updates, and maintains all the information that pertains to estimating our cybersecurity measure, and offers stakeholders quantitative means to make security-related decisions.

  17. Measurement of absorbed doses in organs of medical staff at (18)F-FDG pet examination.

    PubMed

    Fujibuchi, Toshioh; Iimori, Takashi; Isobe, Tomonori; Masuda, Yoshitada; Uchida, Yoshitaka; Matsubayashi, Fumiyasu; Sakae, Takeji

    2010-01-01

    In this study, the organ doses were measured using a human- body phantom simulating a medical staff member, and we considered an effective method for decreasing exposure to staff in positron emission tomography examinations. A fluorescence glass dosimeter was arranged for measurements in various organs. Regarding exposure, the average ratio of the dose at 100 cm from the source to the dose at 30 cm was 0.35. The ratio of the dose at 100 cm with a 3 cm lead shield to the dose at 100 cm with no shielding device was 0.01. To reduce the radiation exposure effectively, medical staff members should inform the patient of the details of the examination in advance, reduce the contact time with the patient during the examination, and maximize their distance from the patient when contact is necessary. PMID:20821099

  18. Multi-Wavelength Measurement of Soot Optical Properties: Influence of Non-Absorbing Coatings

    NASA Astrophysics Data System (ADS)

    Freedman, Andrew; Renbaum-Wollf, Lindsay; Forestieri, Sara; Lambe, Andrew; Cappa, Christopher; Davidovits, Paul; Onasch, Timothy

    2015-04-01

    Soot, a product of incomplete combustion, plays an important role in the earth's climate system through the absorption and scattering of solar radiation. Important in quantifying the direct radiative impacts of soot in climate models, and specifically of black carbon (BC), is the assumed BC refractive index and shape-dependent interaction of light with BC particles. The latter assumption carries significant uncertainty because BC particles are fractal-like, being agglomerates of smaller (20-40 nm) spherules, yet many optical models such as Mie theory in particular, typically assume a spherical particle morphology. It remains unclear under what conditions this is an acceptable assumption. To investigate the ability of various optical models to reproduce observed BC optical properties, we obtained measurements of light absorption, scattering and extinction coefficients and thus single scattering albedo (SSA) of size-resolved soot particles. Measurements were made on denuded soot particles produced using both methane and ethylene as fuels. In addition, these soot particles were coated with dioctyl sebacate or sulfuric acid and the enhancement in the apparent mass absorption coefficient determined. Extinction and absorption were measured using a dual cavity ringdown photoacoustic spectrometer (CRD-PAS) at 405 nm and 532 nm. Scattering and extinction were measured using a CAPS PMssa single scattering albedo monitor (Aerodyne) at 630 nm. Soot particle mass was quantified using a centrifugal particle mass analyzer (CPMA, Cambustion), mobility size with a scanning mobility particle sizer (SMPS, TSI) and soot concentration with a CPC (Brechtel). The results will be interpreted in light of both Mie theory which assumes spherical and uniform particles and Rayleigh-Debye-Gans (RDG) theory, which assumes that the absorption properties of soot are dictated by the individual spherules. For denuded soot, effective refractive indices will be determined.

  19. Measuring intestinal fluid transport in vitro: Gravimetric method versus non-absorbable marker.

    PubMed

    Whittamore, Jonathan M; Genz, Janet; Grosell, Martin; Wilson, Rod W

    2016-04-01

    The gut sac is a long-standing, widely used in vitro preparation for studying solute and water transport, and calculation of these fluxes requires an accurate assessment of volume. This is commonly determined gravimetrically by measuring the change in mass over time. While convenient this likely under-estimates actual net water flux (Jv) due to tissue edema. We evaluated whether the popular in vivo volume marker [(14)C]-PEG 4000, offers a more representative measure of Jvin vitro. We directly compared these two methods in five teleost species (toadfish, flounder, rainbow trout, killifish and tilapia). Net fluid absorption by the toadfish intestine based on PEG was significantly higher, by almost 4-fold, compared to gravimetric measurements, compatible with the latter under-estimating Jv. Despite this, PEG proved inconsistent for all of the other species frequently resulting in calculation of net secretion, in contrast to absorption seen gravimetrically. Such poor parallelism could not be explained by the absorption of [(14)C]-PEG (typically <1%). We identified a number of factors impacting the effectiveness of PEG. One was adsorption to the surface of sample tubes. While it was possible to circumvent this using unlabelled PEG 4000, this had a deleterious effect on PEG-based Jv. We also found sequestration of PEG within the intestinal mucus. In conclusion, the short-comings associated with the accurate representation of Jv by gut sac preparations are not overcome by [(14)C]-PEG. The gravimetric method therefore remains the most reliable measure of Jv and we urge caution in the use of PEG as a volume marker. PMID:26794612

  20. Measuring the total value of a river cleanup.

    PubMed

    Alam, M K; Marinova, D

    2003-01-01

    The paper estimates the total value for the community of the cleanup of the Buriganga River. Dhaka, the capital of Bangladesh, was developed on the bank of the Buriganga River in the early 1600s. The river is now near dead mainly due to human interventions. The paper develops a hypothetical cleanup programme to improve the water quality, which will help the overall environment in and around the river. The value of this programme is estimated within the framework of total economic value; non-marketed benefits are measured through a contingent valuation survey and marketed benefits are estimated using market and shadow prices. The findings of the survey suggest that not only are a significant proportion of the residents willing to pay for the cleanup programme, but many are also willing to contribute in non-monetary ways (mainly their time). When the latter contribution is monetised, it represents 60% of the total value for the non-marketed benefits. The marketed benefits are estimated to represent 58% of the overall value of the cleanup programme (18.6 million US dollars/year). A failure to account for all benefits could lead to a gross underestimation of the desirability of providing public funding for the cleanup of dying rivers. PMID:14653645

  1. Measuring Nursing Value from the Electronic Health Record.

    PubMed

    Welton, John M; Harper, Ellen M

    2016-01-01

    We report the findings of a big data nursing value expert group made up of 14 members of the nursing informatics, leadership, academic and research communities within the United States tasked with 1. Defining nursing value, 2. Developing a common data model and metrics for nursing care value, and 3. Developing nursing business intelligence tools using the nursing value data set. This work is a component of the Big Data and Nursing Knowledge Development conference series sponsored by the University Of Minnesota School Of Nursing. The panel met by conference calls for fourteen 1.5 hour sessions for a total of 21 total hours of interaction from August 2014 through May 2015. Primary deliverables from the bit data expert group were: development and publication of definitions and metrics for nursing value; construction of a common data model to extract key data from electronic health records; and measures of nursing costs and finance to provide a basis for developing nursing business intelligence and analysis systems. PMID:27332163

  2. Kinetic coupling between electron and proton transfer in cytochrome c oxidase: simultaneous measurements of conductance and absorbance changes.

    PubMed Central

    Adelroth, P; Sigurdson, H; Hallén, S; Brzezinski, P

    1996-01-01

    Bovine heart cytochrome c oxidase is an electron-current driven proton pump. To investigate the mechanism by which this pump operates it is important to study individual electron- and proton-transfer reactions in the enzyme, and key reactions in which they are kinetically and thermodynamically coupled. In this work, we have simultaneously measured absorbance changes associated with electron-transfer reactions and conductance changes associated with protonation reactions following pulsed illumination of the photolabile complex of partly reduced bovine cytochrome c oxidase and carbon monoxide. Following CO dissociation, several kinetic phases in the absorbance changes were observed with time constants ranging from approximately 3 microseconds to several milliseconds, reflecting internal electron-transfer reactions within the enzyme. The data show that the rate of one of these electron-transfer reactions, from cytochrome a3 to a on a millisecond time scale, is controlled by a proton-transfer reaction. These results are discussed in terms of a model in which cytochrome a3 interacts electrostatically with a protonatable group, L, in the vicinity of the binuclear center, in equilibrium with the bulk through a proton-conducting pathway, which determines the rate of proton transfer (and indirectly also of electron transfer). The interaction energy of cytochrome a3 with L was determined independently from the pH dependence of the extent of the millisecond-electron transfer and the number of protons released, as determined from the conductance measurements. The magnitude of the interaction energy, 70 meV (1 eV = 1.602 x 10(-19) J), is consistent with a distance of 5-10 A between cytochrome a3 and L. Based on the recently determined high-resolution x-ray structures of bovine and a bacterial cytochrome c oxidase, possible candidates for L and a physiological role for L are discussed. PMID:8901574

  3. Ferrite HOM Absorber for the RHIC ERL

    SciTech Connect

    Hahn,H.; Choi, E.M.; Hammons, L.

    2008-10-01

    A superconducting Energy Recovery Linac is under construction at Brookhaven National Laboratory to serve as test bed for RHIC upgrades. The damping of higher-order modes in the superconducting five-cell cavity for the Energy-Recovery linac at RHIC is performed exclusively by two ferrite absorbers. The ferrite properties have been measured in ferrite-loaded pill box cavities resulting in the permeability values given by a first-order Debye model for the tiled absorber structure and an equivalent permeability value for computer simulations with solid ring dampers. Measured and simulated results for the higher-order modes in the prototype copper cavity are discussed. First room-temperature measurements of the finished niobium cavity are presented which confirm the effective damping of higher-order modes in the ERL. by the ferrite absorbers.

  4. Preprocessing and parameterizing bioimpedance spectroscopy measurements by singular value decomposition.

    PubMed

    Nejadgholi, Isar; Caytak, Herschel; Bolic, Miodrag; Batkin, Izmail; Shirmohammadi, Shervin

    2015-05-01

    In several applications of bioimpedance spectroscopy, the measured spectrum is parameterized by being fitted into the Cole equation. However, the extracted Cole parameters seem to be inconsistent from one measurement session to another, which leads to a high standard deviation of extracted parameters. This inconsistency is modeled with a source of random variations added to the voltage measurement carried out in the time domain. These random variations may originate from biological variations that are irrelevant to the evidence that we are investigating. Yet, they affect the voltage measured by using a bioimpedance device based on which magnitude and phase of impedance are calculated.By means of simulated data, we showed that Cole parameters are highly affected by this type of variation. We further showed that singular value decomposition (SVD) is an effective tool for parameterizing bioimpedance measurements, which results in more consistent parameters than Cole parameters. We propose to apply SVD as a preprocessing method to reconstruct denoised bioimpedance measurements. In order to evaluate the method, we calculated the relative difference between parameters extracted from noisy and clean simulated bioimpedance spectra. Both mean and standard deviation of this relative difference are shown to effectively decrease when Cole parameters are extracted from preprocessed data in comparison to being extracted from raw measurements.We evaluated the performance of the proposed method in distinguishing three arm positions, for a set of experiments including eight subjects. It is shown that Cole parameters of different positions are not distinguishable when extracted from raw measurements. However, one arm position can be distinguished based on SVD scores. Moreover, all three positions are shown to be distinguished by two parameters, R0/R∞ and Fc, when Cole parameters are extracted from preprocessed measurements. These results suggest that SVD could be considered as an

  5. Measurements of absorbed heat flux and water-side heat transfer coefficient in water wall tubes

    NASA Astrophysics Data System (ADS)

    Taler, Jan; Taler, Dawid; Kowal, Andrzej

    2011-04-01

    The tubular type instrument (flux tube) was developed to identify boundary conditions in water wall tubes of steam boilers. The meter is constructed from a short length of eccentric tube containing four thermocouples on the fire side below the inner and outer surfaces of the tube. The fifth thermocouple is located at the rear of the tube on the casing side of the water-wall tube. The boundary conditions on the outer and inner surfaces of the water flux-tube are determined based on temperature measurements at the interior locations. Four K-type sheathed thermocouples of 1 mm in diameter, are inserted into holes, which are parallel to the tube axis. The non-linear least squares problem is solved numerically using the Levenberg-Marquardt method. The heat transfer conditions in adjacent boiler tubes have no impact on the temperature distribution in the flux tubes.

  6. Multispectral metamaterial absorber.

    PubMed

    Grant, J; McCrindle, I J H; Li, C; Cumming, D R S

    2014-03-01

    We present the simulation, implementation, and measurement of a multispectral metamaterial absorber (MSMMA) and show that we can realize a simple absorber structure that operates in the mid-IR and terahertz (THz) bands. By embedding an IR metamaterial absorber layer into a standard THz metamaterial absorber stack, a narrowband resonance is induced at a wavelength of 4.3 μm. This resonance is in addition to the THz metamaterial absorption resonance at 109 μm (2.75 THz). We demonstrate the inherent scalability and versatility of our MSMMA by describing a second device whereby the MM-induced IR absorption peak frequency is tuned by varying the IR absorber geometry. Such a MSMMA could be coupled with a suitable sensor and formed into a focal plane array, enabling multispectral imaging. PMID:24690713

  7. Measurement and Simulation of Thermal Conductivity of Hafnium-Aluminum Thermal Neutron Absorber Material

    NASA Astrophysics Data System (ADS)

    Guillen, Donna Post; Harris, William H.

    2016-05-01

    A metal matrix composite (MMC) material composed of hafnium aluminide (Al3Hf) intermetallic particles in an aluminum matrix has been identified as a promising material for fast flux irradiation testing applications. This material can filter thermal neutrons while simultaneously providing high rates of conductive cooling for experiment capsules. The purpose of this work is to investigate effects of Hf-Al material composition and neutron irradiation on thermophysical properties, which were measured before and after irradiation. When performing differential scanning calorimetry (DSC) on the irradiated specimens, a large exotherm corresponding to material annealment was observed. Therefore, a test procedure was developed to perform DSC and laser flash analysis (LFA) to obtain the specific heat and thermal diffusivity of pre- and post-annealment specimens. This paper presents the thermal properties for three states of the MMC material: (1) unirradiated, (2) as-irradiated, and (3) irradiated and annealed. Microstructure-property relationships were obtained for the thermal conductivity. These relationships are useful for designing components from this material to operate in irradiation environments. The ability of this material to effectively conduct heat as a function of temperature, volume fraction Al3Hf, radiation damage, and annealing is assessed using the MOOSE suite of computational tools.

  8. The measuring of the absorbed dose in human tissue that underwent irradiation with ionizing radiation

    NASA Astrophysics Data System (ADS)

    Bercea, S.; Nikolic, A.; Cenusa, C.; Celarel, A.

    2010-07-01

    Ionizing radiations are radiations of atomic origin (X) or nuclear origin (α, β, γ). They are composed of either subatomic particles (α, β) or electromagnetic waves (X, γ) which possess enough energy to remove electrons from the atoms and molecules of the medium with which particles interact. They thus generate ionizing processes. The effects that are produced by the interaction of the ionizing radiations with a particular medium (which could be human tissue) have different intensities depending on the nature of the incident radiations, on the rate in which these radiations release energy to the medium and on the total amount of energy released to the medium. For this reason, the energy released by a particular type of ionizing radiations to a particular type of medium has become of great interest both for researchers and for specialists who deal with using ionizing radiations in different fields, such as the biomedical one. The aim of the present paper is to briefly present some of the aspects connected to the way certain quantities are defined, quantities which are specific to the interaction of ionizing particles with the medium they pass through and which are also connected to the energy released in the medium. The paper also describes methods of measuring these quantities.

  9. Ultra-low Q values for neutrino mass measurements

    SciTech Connect

    Kopp, Joachim; Merle, Alexander; /Heidelberg, Max Planck Inst.

    2009-11-01

    We investigate weak nuclear decays with extremely small kinetic energy release (Q value) and thus extremely good sensitivity to the absolute neutrino mass scale. In particular, we consider decays into excited daughter states, and we show that partial ionization of the parent atom can help to tune Q values to << 1 keV. We discuss several candidate isotopes undergoing {beta}{sup {+-}}, bound state {beta}, or electron capture decay, and come to the conclusion that a neutrino mass measurement using low-Q decays might only be feasible if no ionization is required, and if future improvements in isotope production technology, nuclear mass spectroscopy, and atomic structure calculations are possible. Experiments using ions, however, are extremely challenging due to the large number of ions that must be stored. New precision data on nuclear excitation levels could help to identify further isotopes with low-Q decay modes and possibly less challenging requirements.

  10. Filter-free integrated sensor array based on luminescence and absorbance measurements using ring-shaped organic photodiodes.

    PubMed

    Abel, Tobias; Sagmeister, Martin; Lamprecht, Bernhard; Kraker, Elke; Köstler, Stefan; Ungerböck, Birgit; Mayr, Torsten

    2012-12-01

    An optical waveguiding sensor array featuring monolithically integrated organic photodiodes as integrated photo-detector, which simplifies the readout system by minimizing the required parts, is presented. The necessity of any optical filters becomes redundant due to the proposed platform geometry, which discriminates between excitation light and sensing signal. The sensor array is capable of measuring luminescence or absorption, and both sensing geometries are based on the identical substrate. It is demonstrated that background light is virtually non-existent. All sensing and waveguide layers, as well as in- and out-coupling elements are assembled by conventional screen-printing techniques. Organic photodiodes are integrated by layer-by-layer vacuum deposition onto glass or common polymer foils. The universal and simple applicability of this sensor chip is demonstrated by sensing schemes for four different analytes. Relative humidity, oxygen, and carbon dioxide are measured in gas phase using luminescence-based sensor schemes; the latter two analytes are also measured by absorbance-based sensor schemes. Furthermore, oxygen and pH in aqueous media were enabled. The consistency of calibration characteristics extending over different sensor chips is verified. PMID:22706404

  11. A new optical method coupling light polarization and Vis-NIR spectroscopy to improve the measured absorbance signal's quality of soil samples.

    NASA Astrophysics Data System (ADS)

    Gobrecht, Alexia; Bendoula, Ryad; Roger, Jean-Michel; Bellon-Maurel, Véronique

    2014-05-01

    Visible - Near-infrared spectroscopy (Vis-NIRS) is now commonly used to measure different physical and chemical parameters of soils, including carbon content. However, prediction model accuracy is insufficient for Vis-NIRS to replace routine laboratory analysis. One of the biggest issues this technique is facing up to is light scattering due to soil particles. It causes departure in the assumed linear relationship between the Absorbance spectrum and the concentration of the chemicals of interest as stated by Beer-Lambert's Law, which underpins the calibration models. Therefore it becomes essential to improve the metrological quality of the measured signal in order to optimize calibration as light/matter interactions are at the basis of the resulting linear modeling. Optics can help to mitigate scattering effect on the signal. We put forward a new optical setup coupling linearly polarized light with a Vis-NIR spectrometer to free the measured spectra from multi-scattering effect. The corrected measured spectrum was then used to compute an Absorbance spectrum of the sample, using Dahm's Equation in the frame of the Representative Layer Theory. This method has been previously tested and validated on liquid (milk+ dye) and powdered (sand + dye) samples showing scattering (and absorbing) properties. The obtained Absorbance was a very good approximation of the Beer-Lambert's law absorbance. Here, we tested the method on a set of 54 soil samples to predict Soil Organic Carbon content. In order to assess the signal quality improvement by this method, we built and compared calibration models using Partial Least Square (PLS) algorithm. The prediction model built from new Absorbance spectrum outperformed the model built with the classical Absorbance traditionally obtained with Vis-NIR diffuse reflectance. This study is a good illustration of the high influence of signal quality on prediction model's performances.

  12. Defining and Computing a Valued Based Cyber Security Measure

    SciTech Connect

    Aissa, Anis Ben; Abercrombie, Robert K; Sheldon, Frederick T; Mili, Ali

    2011-01-01

    In earlier works (Ben-Aissa et al. 2010; Abercrombie et al. 2008; Sheldon et al. 2009), we presented a value based measure of cybersecurity that quantifies the security of a system in concrete terms, specifically, in terms of how much each system stakeholder stands to lose (in dollars per hour of operation) as a result of security threats and system vulnerabilities; our metric varies according to the stakes that each stakeholder has in meeting each security requirement. In this paper, we discuss the specification and design of a system that collects, updates, and maintains all the information that pertains to estimating our cybersecurity measure, and offers stakeholders quantitative means to make security-related decisions.

  13. Transcutaneous oximetry measurement: normal values for the upper limb.

    PubMed

    2016-03-01

    Consistent with the Committee on Publication Ethics guidelines, we the above authors are initiating the retraction of our paper: Young DA, Blake DF, Brown LH: Transcutaneous oximetry measurement: normal values for the upper limb. Diving Hyperb Med. 2012;42(4):208-213. We wish to make the following statement: "The authors voluntarily retract this article after discovering a critical error associated with the instrumentation used in the study, namely the fitting of incorrect sensor membranes on the electrodes of the transcutaneous oximetry device used in the study. This resulted in transcutaneous oxygen tension (PtcO₂) measurements that were consistently lower than those that would have been recorded with the correct electrode membranes in place. We recently confirmed this by comparing the two membrane types once we discovered the error. We are in the process of replicating our work using the correct PtcO₂ specific membranes." PMID:27044465

  14. Measuring energy efficiency in economics: Shadow value approach

    NASA Astrophysics Data System (ADS)

    Khademvatani, Asgar

    For decades, academic scholars and policy makers have commonly applied a simple average measure, energy intensity, for studying energy efficiency. In contrast, we introduce a distinctive marginal measure called energy shadow value (SV) for modeling energy efficiency drawn on economic theory. This thesis demonstrates energy SV advantages, conceptually and empirically, over the average measure recognizing marginal technical energy efficiency and unveiling allocative energy efficiency (energy SV to energy price). Using a dual profit function, the study illustrates how treating energy as quasi-fixed factor called quasi-fixed approach offers modeling advantages and is appropriate in developing an explicit model for energy efficiency. We address fallacies and misleading results using average measure and demonstrate energy SV advantage in inter- and intra-country energy efficiency comparison. Energy efficiency dynamics and determination of efficient allocation of energy use are shown through factors impacting energy SV: capital, technology, and environmental obligations. To validate the energy SV, we applied a dual restricted cost model using KLEM dataset for the 35 US sectors stretching from 1958 to 2000 and selected a sample of the four sectors. Following the empirical results, predicted wedges between energy price and the SV growth indicate a misallocation of energy use in stone, clay and glass (SCG) and communications (Com) sectors with more evidence in the SCG compared to the Com sector, showing overshoot in energy use relative to optimal paths and cost increases from sub-optimal energy use. The results show that energy productivity is a measure of technical efficiency and is void of information on the economic efficiency of energy use. Decomposing energy SV reveals that energy, capital and technology played key roles in energy SV increases helping to consider and analyze policy implications of energy efficiency improvement. Applying the marginal measure, we also

  15. Direct reading measurement of absorbed dose with plastic scintillators--the general concept and applications to ophthalmic plaque dosimetry.

    PubMed

    Flühs, D; Heintz, M; Indenkämpen, F; Wieczorek, C

    1996-03-01

    We have developed dosemeters based on plastic scintillators for a variety of applications in radiation therapy. The dosemeters consist basically of a tissue-substituting scintillator probe, an optical fiber light guide, and a photomultiplier tube. The background light generated in the light guide can be compensated by a simultaneous measurement of the light from a blind fiber. Plastic scintillator dosemeters combine several advantageous properties which render them superior to other dosemeter types for many applications: minimal disturbance of the radiation field because of the homogeneous detector volume and the approximate water equivalence; no dependence on temperature and pressure (under standard clinical conditions) and angle of radiation incidence; no high voltage in the probe; high spatial resolution due to small detector volumes; direct reading of absorbed doses; and a large dynamical range. The high spatial resolution together with direct reading make these detectors suitable for real-time 3-D dosimetry using multi-channel detector systems. Such a system has been developed for eye plaque dosimetry and successfully employed for dosimetric treatment optimization. The plaque optimization can be performed by dosimetric measurements for the individual patient ("dosimetric treatment planning"). The time consumption for this procedure is less than for a physically correct computer-based therapy planning, e.g., by means of a Monte Carlo simulation. PMID:8815386

  16. Sound Absorbers

    NASA Astrophysics Data System (ADS)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  17. Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes

    NASA Technical Reports Server (NTRS)

    Miamee, A. G.

    1988-01-01

    Let B be a Banach space and H and K two Hilbert spaces. The spectral dilation of L(B,H)-valued measures is studied and it is shown that the recent results of Makagon and Salehi (1986) and Rosenberg (1982) on the dilation of L(K,H)-valued measures can be extended to hold for the general Banach space setting of L(B,H)-valued measures. These L(B,H)-valued measures are closely connected to the Banach space valued processes. This connection is recalled and as application of spectral dilation of L(B,H)-valued measures the well known stationary dilation results for scalar valued processes is extended to the case of Banach space valued processes.

  18. Spectral dilation of L(B,H)-valued measures and its application to stationary dilation for Banach space valued processes

    NASA Technical Reports Server (NTRS)

    Miamee, A. G.

    1989-01-01

    Let B be a Banach space and H and K to Hilbert spaces. The spectral dilation of L(B,H)-valued measures is studied and it is shown that the recent results of Makagon and Salehi (1986) and Rosenberg (1982) on the dilation of L(K,H)-valued measures can be extended to hold for the general Banach space setting of L(B,H)-valued measures. These L(B,H)-valued measures are closely connected to the Banach space valued processes. This connection is recalled and as application of spectral dilation of L(B,H)-valued measures the well known stationary dilation results for scalar valued processes is extended to the case of Banach space valued processes.

  19. Accuracy and optimal timing of activity measurements in estimating the absorbed dose of radioiodine in the treatment of Graves' disease

    NASA Astrophysics Data System (ADS)

    Merrill, S.; Horowitz, J.; Traino, A. C.; Chipkin, S. R.; Hollot, C. V.; Chait, Y.

    2011-02-01

    Calculation of the therapeutic activity of radioiodine 131I for individualized dosimetry in the treatment of Graves' disease requires an accurate estimate of the thyroid absorbed radiation dose based on a tracer activity administration of 131I. Common approaches (Marinelli-Quimby formula, MIRD algorithm) use, respectively, the effective half-life of radioiodine in the thyroid and the time-integrated activity. Many physicians perform one, two, or at most three tracer dose activity measurements at various times and calculate the required therapeutic activity by ad hoc methods. In this paper, we study the accuracy of estimates of four 'target variables': time-integrated activity coefficient, time of maximum activity, maximum activity, and effective half-life in the gland. Clinical data from 41 patients who underwent 131I therapy for Graves' disease at the University Hospital in Pisa, Italy, are used for analysis. The radioiodine kinetics are described using a nonlinear mixed-effects model. The distributions of the target variables in the patient population are characterized. Using minimum root mean squared error as the criterion, optimal 1-, 2-, and 3-point sampling schedules are determined for estimation of the target variables, and probabilistic bounds are given for the errors under the optimal times. An algorithm is developed for computing the optimal 1-, 2-, and 3-point sampling schedules for the target variables. This algorithm is implemented in a freely available software tool. Taking into consideration 131I effective half-life in the thyroid and measurement noise, the optimal 1-point time for time-integrated activity coefficient is a measurement 1 week following the tracer dose. Additional measurements give only a slight improvement in accuracy.

  20. Reference Values for Body Composition and Anthropometric Measurements in Athletes

    PubMed Central

    Santos, Diana A.; Dawson, John A.; Matias, Catarina N.; Rocha, Paulo M.; Minderico, Cláudia S.; Allison, David B.; Sardinha, Luís B.; Silva, Analiza M.

    2014-01-01

    Background Despite the importance of body composition in athletes, reference sex- and sport-specific body composition data are lacking. We aim to develop reference values for body composition and anthropometric measurements in athletes. Methods Body weight and height were measured in 898 athletes (264 female, 634 male), anthropometric variables were assessed in 798 athletes (240 female and 558 male), and in 481 athletes (142 female and 339 male) with dual-energy X-ray absorptiometry (DXA). A total of 21 different sports were represented. Reference percentiles (5th, 25th, 50th, 75th, and 95th) were calculated for each measured value, stratified by sex and sport. Because sample sizes within a sport were often very low for some outcomes, the percentiles were estimated using a parametric, empirical Bayesian framework that allowed sharing information across sports. Results We derived sex- and sport-specific reference percentiles for the following DXA outcomes: total (whole body scan) and regional (subtotal, trunk, and appendicular) bone mineral content, bone mineral density, absolute and percentage fat mass, fat-free mass, and lean soft tissue. Additionally, we derived reference percentiles for height-normalized indexes by dividing fat mass, fat-free mass, and appendicular lean soft tissue by height squared. We also derived sex- and sport-specific reference percentiles for the following anthropometry outcomes: weight, height, body mass index, sum of skinfold thicknesses (7 skinfolds, appendicular skinfolds, trunk skinfolds, arm skinfolds, and leg skinfolds), circumferences (hip, arm, midthigh, calf, and abdominal circumferences), and muscle circumferences (arm, thigh, and calf muscle circumferences). Conclusions These reference percentiles will be a helpful tool for sports professionals, in both clinical and field settings, for body composition assessment in athletes. PMID:24830292

  1. Use of the Normalized Absorbance Ratio as an Internal Standardization Approach To Minimize Measurement Error in Enzyme-Linked Immunosorbent Assays for Diagnosis of Human Papillomavirus Infection▿

    PubMed Central

    Ramanakumar, Agnihotram V.; Thomann, Patricia; Candeias, Joao M.; Ferreira, Silvaneide; Villa, Luisa L.; Franco, Eduardo L.

    2010-01-01

    The serological detection of antibodies against human papillomavirus (HPV) antigens is a useful tool to determine exposure to genital HPV infection and in predicting the risk of infection persistence and associated lesions. Enzyme-linked immunosorbent assays (ELISAs) are commonly used for seroepidemiological studies of HPV infection but are not standardized. Intra- and interassay performance variation is difficult to control, especially in cohort studies that require the testing of specimens over extended periods. We propose the use of normalized absorbance ratios (NARs) as a standardization procedure to control for such variations and minimize measurement error. We compared NAR and ELISA optical density (OD) values for the strength of the correlation between serological results for paired visits 4 months apart and HPV-16 DNA positivity in cervical specimens from a cohort investigation of 2,048 women tested with an ELISA using HPV-16 virus-like particles. NARs were calculated by dividing the mean blank-subtracted (net) ODs by the equivalent values of a control serum pool included in the same plate in triplicate, using different dilutions. Stronger correlations were observed with NAR values than with net ODs at every dilution, with an overall reduction in nonexplained regression variability of 39%. Using logistic regression, the ranges of odds ratios of HPV-16 DNA positivity contrasting upper and lower quintiles at different dilutions and their averages were 4.73 to 5.47 for NARs and 2.78 to 3.28 for net ODs, with corresponding significant improvements in seroreactivity-risk trends across quintiles when NARs were used. The NAR standardization is a simple procedure to reduce measurement error in seroepidemiological studies of HPV infection. PMID:20053861

  2. Measurement and global analysis of the absorbance changes in the photocycle of the photoactive yellow protein from Ectothiorhodospira halophila.

    PubMed Central

    Hoff, W D; van Stokkum, I H; van Ramesdonk, H J; van Brederode, M E; Brouwer, A M; Fitch, J C; Meyer, T E; van Grondelle, R; Hellingwerf, K J

    1994-01-01

    The photocycle of the photoactive yellow protein (PYP) from Ectothiorhodospira halophila was examined by time-resolved difference absorption spectroscopy in the wavelength range of 300-600 nm. Both time-gated spectra and single wavelength traces were measured. Global analysis of the data established that in the time domain between 5 ns and 2 s only two intermediates are involved in the room temperature photocycle of PYP, as has been proposed before (Meyer T.E., E. Yakali, M. A. Cusanovich, and G. Tollin. 1987. Biochemistry. 26:418-423; Meyer, T. E., G. Tollin, T. P. Causgrove, P. Cheng, and R. E. Blankenship. 1991. Biophys. J. 59:988-991). The first, red-shifted intermediate decays biexponentially (60% with tau = 0.25 ms and 40% with tau = 1.2 ms) to a blue-shifted intermediate. The last step of the photocycle is the biexponential (93% with tau = 0.15 s and 7% with tau = 2.0 s) recovery to the ground state of the protein. Reconstruction of the absolute spectra of these photointermediates yielded absorbance maxima of about 465 and 355 nm for the red- and blue-shifted intermediate with an epsilon max at about 50% and 40% relative to the epsilon max of the ground state. The quantitative analysis of the photocycle in PYP described here paves the way to a detailed biophysical analysis of the processes occurring in this photoreceptor molecule. PMID:7819501

  3. A graphite calorimeter for absolute measurements of absorbed dose to water: application in medium-energy x-ray filtered beams

    NASA Astrophysics Data System (ADS)

    Pinto, M.; Pimpinella, M.; Quini, M.; D'Arienzo, M.; Astefanoaei, I.; Loreti, S.; Guerra, A. S.

    2016-02-01

    The Italian National Institute of Ionizing Radiation Metrology (ENEA-INMRI) has designed and built a graphite calorimeter that, in a water phantom, has allowed the determination of the absorbed dose to water in medium-energy x-rays with generating voltages from 180 to 250 kV. The new standard is a miniaturized three-bodies calorimeter, with a disc-shaped core of 21 mm diameter and 2 mm thickness weighing 1.134 g, sealed in a PMMA waterproof envelope with air-evacuated gaps. The measured absorbed dose to graphite is converted into absorbed dose to water by means of an energy-dependent conversion factor obtained from Monte Carlo simulations. Heat-transfer correction factors were determined by FEM calculations. At a source-to-detector distance of 100 cm, a depth in water of 2 g cm-2, and at a dose rate of about 0.15 Gy min-1, results of calorimetric measurements of absorbed dose to water, D w, were compared to experimental determinations, D wK, obtained via an ionization chamber calibrated in terms of air kerma, according to established dosimetry protocols. The combined standard uncertainty of D w and D wK were estimated as 1.9% and 1.7%, respectively. The two absorbed dose to water determinations were in agreement within 1%, well below the stated measurement uncertainties. Advancements are in progress to extend the measurement capability of the new in-water-phantom graphite calorimeter to other filtered medium-energy x-ray qualities and to reduce the D w uncertainty to around 1%. The new calorimeter represents the first implementation of in-water-phantom graphite calorimetry in the kilovoltage range and, allowing independent determinations of D w, it will contribute to establish a robust system of absorbed dose to water primary standards for medium-energy x-ray beams.

  4. Review of reconstruction of radiation incident air kerma by measurement of absorbed dose in tooth enamel with EPR.

    PubMed

    Wieser, A

    2012-03-01

    Electron paramagnetic resonance dosimetry with tooth enamel has been proved to be a reliable method to determine retrospectively exposures from photon fields with minimal detectable doses of 100 mGy or lower, which is lower than achievable with cytogenetic dose reconstruction methods. For risk assessment or validating dosimetry systems for specific radiation incidents, the relevant dose from the incident has to be calculated from the total absorbed dose in enamel by subtracting additional dose contributions from the radionuclide content in teeth, natural external background radiation and medical exposures. For calculating organ doses or evaluating dosimetry systems the absorbed dose in enamel from a radiation incident has to be converted to air kerma using dose conversion factors depending on the photon energy spectrum and geometry of the exposure scenario. This paper outlines the approach to assess individual dose contributions to absorbed dose in enamel and calculate individual air kerma of a radiation incident from the absorbed dose in tooth enamel. PMID:22128353

  5. SU-E-T-516: Measurement of the Absorbed Dose Rate in Water Under Reference Conditions in a CyberKnife Unit

    SciTech Connect

    Aragon-Martinez, N; Hernandez-Guzman, A; Gomez-Munoz, A; Massillon-JL, G

    2014-06-01

    Purpose: This paper aims to measure the absorbed-dose-rate in a CyberKnife unit reference-field (6cm diameter) using three ionization chambers (IC) following the new IAEA/AAPM formalism and Gafchromic film (MD-V3-55 and EBT3) protocol according to our work reported previously. Methods: The absorbed-dose-rates were measured at 90cm and 70cm SSD in a 10cmx10cm field and at 70cm SSD in a 5.4cmx5.4cm equivalent to 6cm diameter field using a linac Varian iX. All measurements were performed at 10cm depth in water. The correction factors that account for the difference between the IC response on the reference field and the CyberKnife reference field, k-(Q-msr,Q)^(f-msr,f-ref), were evaluated and Gafchromic film were calibrated using the results obtained above. Under the CyberKnife reference conditions, the factors were used to measure the absorbed-dose-rate with IC according to the new formalism and the calibrated film was irradiated in water. The film calibration curve was used to evaluate the absorbed-dose-rate in the CyberKnife unit. Results: Difference up to 2.56% is observed between dose-rate measured with IC in the reference 10cmx10cm field, depending where the chamber was calibrated, which was not reflected in the correction factor k-(Q-msr,Q)^(f-msr,f-ref ) where variations of ~0.15%-0.5% were obtained. Within measurements uncertainties, maximum difference of 1.8% on the absorbed-dose-rate in the CyberKnife reference field is observed between all IC and the films Conclusion: Absorbed-dose-rate to water was measured in a CyberKnife reference field with acceptable accuracy (combined uncertainties ~1.32%-1.73%, k=1) using three IC and films. The MD-V3-55 film as well as the new IAEA/AAPM formalism can be considered as a suitable dosimetric method to measure absorbed-dose-rate to water in small and non-standard CyberKnife fields used in clinical treatments However, the EBT3 film is not appropriated due to the high uncertainty provided (combined uncertainty ~9%, k=1

  6. Ion chamber absorbed dose calibration coefficients, N{sub D,w}, measured at ADCLs: Distribution analysis and stability

    SciTech Connect

    Muir, B. R.

    2015-04-15

    Purpose: To analyze absorbed dose calibration coefficients, N{sub D,w}, measured at accredited dosimetry calibration laboratories (ADCLs) for client ionization chambers to study (i) variability among N{sub D,w} coefficients for chambers of the same type calibrated at each ADCL to investigate ion chamber volume fluctuations and chamber manufacturing tolerances; (ii) equivalency of ion chamber calibration coefficients measured at different ADCLs by intercomparing N{sub D,w} coefficients for chambers of the same type; and (iii) the long-term stability of N{sub D,w} coefficients for different chamber types by investigating repeated chamber calibrations. Methods: Large samples of N{sub D,w} coefficients for several chamber types measured over the time period between 1998 and 2014 were obtained from the three ADCLs operating in the United States. These are analyzed using various graphical and numerical statistical tests for the four chamber types with the largest samples of calibration coefficients to investigate (i) and (ii) above. Ratios of calibration coefficients for the same chamber, typically obtained two years apart, are calculated to investigate (iii) above and chambers with standard deviations of old/new ratios less than 0.3% meet stability requirements for accurate reference dosimetry recommended in dosimetry protocols. Results: It is found that N{sub D,w} coefficients for a given chamber type compared among different ADCLs may arise from differing probability distributions potentially due to slight differences in calibration procedures and/or the transfer of the primary standard. However, average N{sub D,w} coefficients from different ADCLs for given chamber types are very close with percent differences generally less than 0.2% for Farmer-type chambers and are well within reported uncertainties. Conclusions: The close agreement among calibrations performed at different ADCLs reaffirms the Calibration Laboratory Accreditation Subcommittee process of ensuring

  7. Oxygen radical absorbance capacity (ORAC) of cyclodextrin-solubilized flavonoids, resveratrol and astaxanthin as measured with the ORAC-EPR method.

    PubMed

    Sueishi, Yoshimi; Ishikawa, Misa; Yoshioka, Daisuke; Endoh, Nobuyuki; Oowada, Shigeru; Shimmei, Masashi; Fujii, Hirotada; Kotake, Yashige

    2012-03-01

    Recently, we proposed an oxygen radical absorbance capacity method that directly quantifies the antioxidant's scavenging capacity against free radicals and evaluated the radical scavenging abilities for water soluble antioxidant compounds. In this study, we determined the radical scavenging abilities of lipophilic antioxidants which were solubilized by cyclodextrin in water. Commonly employed fluorescence-based method measures the antioxidant's protection capability for the fluorescent probe, while we directly quantify free-radical level using electron paramagnetic resonance spin trapping technique. In addition, the spin trapping-based method adopted controlled UV-photolysis of azo-initiator for free radical generation, but in fluorescence-based method, thermal decomposition of azo-initiator was utilized. We determined the radical scavenging abilities of seven well-known lipophilic antioxidants (five flavonoids, resveratrol and astaxanthin), using methylated β-cyclodextrin as a solubilizer. The results indicated that the agreement between spin trapping-based and fluorescence-based values was only fair partly because of a large variation in the previous fluorescence-based data. Typical radical scavenging abilities in trolox equivalent unit are: catechin 0.96; epicatechin 0.94; epigallocatechin gallate 1.3; kaempferol 0.37; myricetin 3.2; resveratrol 0.64; and astaxanthin 0.28, indicating that myricetin possesses the highest antioxidant capacity among the compounds tested. We sorted out the possible causes of the deviation between the two methods. PMID:22448093

  8. The Measurement of Values: Behavioral Science and Philosophical Approaches. Modern Concepts of Philosophy Series.

    ERIC Educational Resources Information Center

    Handy, Rollo

    The work of behavioral scientists and philosophers on value measurement is discussed, including a review of issues, controversies, and several attempts to measure values. The author points out vast disagreement in existing literature about value measurement, definitions of measurement and values in general, and the meaning of the scientific…

  9. Long-term stability of liquid ionization chambers with regard to their qualification as local reference dosimeters for low dose-rate absorbed dose measurements in water.

    PubMed

    Bahar-Gogani, J; Grindborg, J E; Johansson, B E; Wickman, G

    2001-03-01

    The long-term sensitivity and calibration stability of liquid ionization chambers (LICs) has been studied at a local and a secondary standards dosimetry laboratory over a period of 3 years. The chambers were transported several times by mail between the two laboratories for measurements. The LICs used in this work are designed for absorbed dose measurements in the dose rate region of 0.1-100 mGy min(-1) and have a liquid layer thickness of 1 mm and a sensitive volume of 16.2 mm3. The liquids used as sensitive media in the chambers are mixtures of isooctane (C8H18) and tetramethylsilane (Si(CH3)4) in different proportions (about 2 to 1). Operating at a polarizing voltage of 300 V the leakage current of the chambers was stable and never exceeded 3% of the observable current at a dose rate of about 1 mGy min(-1). The volume sensitivity of the chambers was measured to be of the order of 10(-9) C Gy(-1) mm3. No systematic changes in the absorbed dose to water calibration was observed for any of the chambers during the test period (sigma < 0.2%). Variations in chamber dose response with small changes in the polarizing voltage as well as sensitivity changes with accumulated absorbed dose were also investigated. Measurements showed that the LIC response varies by 0.15% per 1% change in applied voltage around 300 V. No significant change could be observed in the LIC sensitivity after a single absorbed dose of 15 kGy. The results indicate that the LIC can be made to serve as a calibration transfer instrument and a reference detector for absorbed dose to water determinations providing good precision and long-term reproducibility. PMID:11277221

  10. Methane and carbon dioxide increases in the urban boundary layer: Inferences from whole-column infrared absorbance measurements

    SciTech Connect

    Gurney, K.R.; Hansen, A.D.A.; Rosen, H.

    1988-01-01

    Using the sun as an infrared source, we determined the total atmospheric column absorbance of methane and carbon dioxide spectral lines in the 8- to 10-..mu..m infrared region. At our laboratory located in an urban region, these absorbances showed fluctuations larger than can be accounted for by known variabilities in the background atmosphere. We interpret these observations in terms of large changes in concentration of methane and carbon dioxide within the urban boundary layer. These increases could affect the radiative balance in urban locations and contribute to the urban heat island. copyright American Geophysical Union 1988

  11. Liquid Cryogen Absorber for MICE

    SciTech Connect

    Baynham, D.E.; Bish, P.; Bradshaw, T.W.; Cummings, M.A.; Green,M.A.; Ishimoto, S.; Ivaniouchenkov, I.; Lau, W.; Yang, S.Q.; Zisman, M.S.

    2005-08-20

    The Muon Ionization Cooling Experiment (MICE) will test ionization cooling of muons. In order to have effective ionization cooling, one must use an absorber that is made from a low-z material. The most effective low z materials for ionization cooling are hydrogen, helium, lithium hydride, lithium and beryllium, in that order. In order to measure the effect of material on cooling, several absorber materials must be used. This report describes a liquid-hydrogen absorber that is within a pair of superconducting focusing solenoids. The absorber must also be suitable for use with liquid helium. The following absorber components are discussed in this report; the absorber body, its heat exchanger, the hydrogen system, and the hydrogen safety. Absorber cooling and the thin windows are not discussed here.

  12. Fractional absorption of active absorbable algal calcium (AAACa) and calcium carbonate measured by a dual stable-isotope method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    With the use of stable isotopes, this study aimed to compare the bioavailability of active absorbable algal calcium (AAACa), obtained from oyster shell powder heated to a high temperature, with an additional heated seaweed component (Heated Algal Ingredient, HAI), with that of calcium carbonate. In ...

  13. Measuring Strategic Value-Drivers for Managing Intellectual Capital

    ERIC Educational Resources Information Center

    Bose, S.; Oh, K. B.

    2004-01-01

    In an evolving business environment characterised by globalisation and a challenging competitive paradigm, it is imperative for strategic management processes to focus on the financial perspectives of value and risk in intellectual capital to create sustainability in long-term value. This paper presents the key issues pertaining to the strategic…

  14. Identifying, Measuring and Monitoring Value during Project Development

    ERIC Educational Resources Information Center

    Kliniotou, Maria

    2004-01-01

    This paper describes the findings of the research done by Loughborough University in conjunction with ten construction industry collaborators in an attempt to identify what construction professionals mean by value. The aim of the research is to establish a common approach to identify value in projects and to monitor its development throughout the…

  15. Why Add Value in Assessment? A Pilot Project in Ohio Gains Interest in Value-Added Measurements of Individual Students

    ERIC Educational Resources Information Center

    Mahoney, James W.

    2004-01-01

    In this article, the author suggests that good teachers add value in a number of measurable and immeasurable ways. While the gain of a student in mathematics can be measured, it is impossible to measure the impact of a teacher who motivated a child to want to do math. Teachers cannot control how kids enter the classroom and should not be held…

  16. Value-Added Measures of Teacher Candidates' Dispositions

    ERIC Educational Resources Information Center

    Cosgrove, Maryellen; Carpenter, Barbara

    2012-01-01

    This article describes how a teacher preparation program can positively impact professional dispositions. Pre and post essays from a sample of sixty candidates were qualitatively analyzed to determine the value-added growth of their professional dispositions.

  17. Intensity-Value Corrections for Integrating Sphere Measurements of Solid Samples Measured Behind Glass

    SciTech Connect

    Johnson, Timothy J.; Bernacki, Bruce E.; Redding, Rebecca L.; Su, Yin-Fong; Brauer, Carolyn S.; Myers, Tanya L.; Stephan, Eric G.

    2014-11-01

    Accurate and calibrated directional-hemispherical reflectance spectra of solids are important for both in situ and remote sensing. Many solids are in the form of powders or granules and to measure their diffuse reflectance spectra in the laboratory, it is often necessary to place the samples behind a transparent medium such as glass for the ultraviolet (UV), visible, or near-infrared spectral regions. Using both experimental methods and a simple optical model, we demonstrate that glass (fused quartz in our case) leads to artifacts in the reflectance values. We report our observations that the measured reflectance values, for both hemispherical and diffuse reflectance, are distorted by the additional reflections arising at the air–quartz and sample–quartz interfaces. The values are dependent on the sample reflectance and are offset in intensity in the hemispherical case, leading to measured values up to ~6% too high for a 2% reflectance surface, ~3.8% too high for 10% reflecting surfaces, approximately correct for 40–60% diffuse-reflecting surfaces, and ~1.5% too low for 99% reflecting Spectralon® surfaces. For the case of diffuse-only reflectance, the measured values are uniformly too low due to the polished glass, with differences of nearly 6% for a 99% reflecting matte surface. The deviations arise from the added reflections from the quartz surfaces, as verified by both theory and experiment, and depend on sphere design. Finally, empirical correction factors were implemented into post-processing software to redress the artifact for hemispherical and diffuse reflectance data across the 300–2300 nm range.

  18. Intensity-value corrections for integrating sphere measurements of solid samples measured behind glass.

    PubMed

    Johnson, Timothy J; Bernacki, Bruce E; Redding, Rebecca L; Su, Yin-Fong; Brauer, Carolyn S; Myers, Tanya L; Stephan, Eric G

    2014-01-01

    Accurate and calibrated directional-hemispherical reflectance spectra of solids are important for both in situ and remote sensing. Many solids are in the form of powders or granules and to measure their diffuse reflectance spectra in the laboratory, it is often necessary to place the samples behind a transparent medium such as glass for the ultraviolet (UV), visible, or near-infrared spectral regions. Using both experimental methods and a simple optical model, we demonstrate that glass (fused quartz in our case) leads to artifacts in the reflectance values. We report our observations that the measured reflectance values, for both hemispherical and diffuse reflectance, are distorted by the additional reflections arising at the air-quartz and sample-quartz interfaces. The values are dependent on the sample reflectance and are offset in intensity in the hemispherical case, leading to measured values up to ~6% too high for a 2% reflectance surface, ~3.8% too high for 10% reflecting surfaces, approximately correct for 40-60% diffuse-reflecting surfaces, and ~1.5% too low for 99% reflecting Spectralon® surfaces. For the case of diffuse-only reflectance, the measured values are uniformly too low due to the polished glass, with differences of nearly 6% for a 99% reflecting matte surface. The deviations arise from the added reflections from the quartz surfaces, as verified by both theory and experiment, and depend on sphere design. Empirical correction factors were implemented into post-processing software to redress the artifact for hemispherical and diffuse reflectance data across the 300-2300 nm range. PMID:25280186

  19. Ultrasmall polarization rotation measurements via weak value amplification

    NASA Astrophysics Data System (ADS)

    de Lima Bernardo, Bertúlio; Azevedo, Sérgio; Rosas, Alexandre

    2014-06-01

    We propose a framework to analyze weak measurements based on an angular version of the von Neumann measurement scheme, where the coupling between the system and the meter causes rotation of the measuring variable. We also discuss an experimental application of this theory in which measurements of weak optical activity and reflection-induced polarization rotation could be amplified in nearly two orders of magnitude. It can shed a new light on a great variety of physical chemistry, molecular biology and nanotechnology studies.

  20. Combining linear polarization spectroscopy and the Representative Layer Theory to measure the Beer-Lambert law absorbance of highly scattering materials.

    PubMed

    Gobrecht, Alexia; Bendoula, Ryad; Roger, Jean-Michel; Bellon-Maurel, Véronique

    2015-01-01

    Visible and Near Infrared (Vis-NIR) Spectroscopy is a powerful non destructive analytical method used to analyze major compounds in bulk materials and products and requiring no sample preparation. It is widely used in routine analysis and also in-line in industries, in-vivo with biomedical applications or in-field for agricultural and environmental applications. However, highly scattering samples subvert Beer-Lambert law's linear relationship between spectral absorbance and the concentrations. Instead of spectral pre-processing, which is commonly used by Vis-NIR spectroscopists to mitigate the scattering effect, we put forward an optical method, based on Polarized Light Spectroscopy to improve the absorbance signal measurement on highly scattering samples. This method selects part of the signal which is less impacted by scattering. The resulted signal is combined in the Absorption/Remission function defined in Dahm's Representative Layer Theory to compute an absorbance signal fulfilling Beer-Lambert's law, i.e. being linearly related to concentration of the chemicals composing the sample. The underpinning theories have been experimentally evaluated on scattering samples in liquid form and in powdered form. The method produced more accurate spectra and the Pearson's coefficient assessing the linearity between the absorbance spectra and the concentration of the added dye improved from 0.94 to 0.99 for liquid samples and 0.84-0.97 for powdered samples. PMID:25467494

  1. On the structure of invariant measures for set-valued maps

    SciTech Connect

    Gorbachev, Aleksei N; Stepin, Anatolii M

    2011-09-30

    Properties of measures invariant with respect to set-valued maps are studied. It is shown that an absolutely continuous invariant measure for a set-valued map need not be unique, and the set of all invariant measures need not be a Choquet simplex. The problem concerning the existence of invariant measures with respect to set-valued maps parametrized by single-valued and set-valued maps of the circle having various smoothness classes is studied. Bibliography: 13 titles.

  2. Toward a Reliable and Valid Measure of Institutional Mission and Values Perception: The DePaul Values Inventory

    ERIC Educational Resources Information Center

    Ferrari, Joseph R.; Cowman, Shaun E.

    2004-01-01

    Across three studies, the development of a reliable and valid measure of perceptions by students of an urban, private, faith-based teaching university's mission and values was assessed. Study 1 presented scale construction and reliability of the DePaul Values Inventory (DeVI) with undergraduates (n = 111), yielding a final 22-item rating scale…

  3. The assessment of climatology of absorbing aerosol field with integration of aerosol-climate model, and ground-based and satellite remote sensing measurements

    NASA Astrophysics Data System (ADS)

    Jeong, G.; Wang, C.; Mahowald, N. M.; Rigby, M. L.; Martins, J.

    2009-12-01

    Absorbing aerosols play important roles in the Earth’s radiation budget and atmospheric circulation by absorbing sunlight and heating the atmosphere while cooling the surface. The strength of such effects depends on microphysical processes in the lifecycle of absorbing aerosols and their emissions to the atmosphere. Even though the knowledge of aerosol controlling processes and the techniques measuring aerosol properties have been greatly advanced, there are still significant gaps between model results and measurement data. The goal of this study is to minimize the model-observation discrepancy and to assess global 3-D absorbing aerosol fields. To achieve this goal, we investigate the errors related to aerosol models and measurements, and optimize the emissions of anthropogenic absorbing aerosols (BC) used in the models. In this study we first derive the aerosol optical depth (AOD) and absorbing aerosol optical depth (AAOD) of anthropogenic aerosols using the 3-D interactive aerosol-climate model [Kim et al., 2008] developed based on NCAR CAM3, running in an aerosol-transport-model (ATM) driven by NCEP/NCAR reanalysis data (2001~2003). Aerosol transformation in the atmosphere is fully considered in this model. We also derived the AOD and AAOD of dust aerosols based on the climatology from the Model of Atmospheric Transport and Chemistry (MATCH) driven by the NCEP/NCAR reanalysis data [Mahowald et al., 1997; Kistler et al., 2001]. In addition, the climatology (10-year mean) of the CAM3 sea salt model (Mahowald et al., 2006) is used to calculate the AOD of sea salt aerosols. An inverse modeling technique (Kalman filtering) is used to optimize the emissions of BC aerosols by minimizing the model-observation discrepancy of AAOD, and the emissions of anthropogenic organic carbon (OC) aerosols and SO2 by minimizing the model-observation discrepancy of AOD. Initial estimates of carbonaceous aerosol emission due to fossil fuel are taken from the MIT EPPA model and Bond

  4. A graphite calorimeter for absolute measurements of absorbed dose to water: application in medium-energy x-ray filtered beams.

    PubMed

    Pinto, M; Pimpinella, M; Quini, M; D'Arienzo, M; Astefanoaei, I; Loreti, S; Guerra, A S

    2016-02-21

    The Italian National Institute of Ionizing Radiation Metrology (ENEA-INMRI) has designed and built a graphite calorimeter that, in a water phantom, has allowed the determination of the absorbed dose to water in medium-energy x-rays with generating voltages from 180 to 250 kV. The new standard is a miniaturized three-bodies calorimeter, with a disc-shaped core of 21 mm diameter and 2 mm thickness weighing 1.134 g, sealed in a PMMA waterproof envelope with air-evacuated gaps. The measured absorbed dose to graphite is converted into absorbed dose to water by means of an energy-dependent conversion factor obtained from Monte Carlo simulations. Heat-transfer correction factors were determined by FEM calculations. At a source-to-detector distance of 100 cm, a depth in water of 2 g cm(-2), and at a dose rate of about 0.15 Gy min(-1), results of calorimetric measurements of absorbed dose to water, D(w), were compared to experimental determinations, D wK, obtained via an ionization chamber calibrated in terms of air kerma, according to established dosimetry protocols. The combined standard uncertainty of D(w) and D(wK) were estimated as 1.9% and 1.7%, respectively. The two absorbed dose to water determinations were in agreement within 1%, well below the stated measurement uncertainties. Advancements are in progress to extend the measurement capability of the new in-water-phantom graphite calorimeter to other filtered medium-energy x-ray qualities and to reduce the D(w) uncertainty to around 1%. The new calorimeter represents the first implementation of in-water-phantom graphite calorimetry in the kilovoltage range and, allowing independent determinations of D(w), it will contribute to establish a robust system of absorbed dose to water primary standards for medium-energy x-ray beams. PMID:26841127

  5. Surface Modification of Polycrystalline Cu(In,Ga)Se2 Thin-Film Solar Cell Absorber Surfaces for PEEM Measurements

    SciTech Connect

    Wilks, R. G.; Contreras, M. A.; Lehmann, S.; Herrero-Albillos, J.; Bismaths, L. T.; Kronast, F.; Noufi, R.; Bar, M.

    2011-01-01

    We present a thorough examination of the {micro}m-scale topography of Cu(In, Ga)Se{sub 2} ('CIGSe') thin-film solar cell absorbers using different microscopy techniques. We specifically focus on the efficacy of preparing smooth sample surfaces - by etching in aqueous bromine solution - for a spatially resolved study of their chemical and electronic structures using photoelectron emission microscopy (PEEM). The etching procedure is shown to reduce the CIGSe surface roughness from ca. 40 to 25 nm after 40s etching, resulting in an increase in the quality of the obtained PEEM images. Furthermore we find that the average observed grain size at the etched surfaces appears larger than at the unetched surfaces. Using a liftoff procedure, it is additionally shown that the backside of the absorber is flat but finely patterned, likely due to being grown on the finely-structured Mo back contact.

  6. [What is the value of measuring "singer's formant" in phoniatry?].

    PubMed

    Klingholz, F

    1992-11-01

    The singing formant is the product of an articulatory gesture. Devices for phonetogram measurement often claim the ability to determine it. However, they measure rather the overtone content or the noise of the voice than the formant. Moreover, the voice efficiency (ratio of the sound pressure in the frequency band 2-5 kHz to the total sound pressure), also measured by these devices, is not defined in a physical or physiological sense. Such measurement does not evaluate the efficiency of the vocal apparatus. PMID:1463568

  7. Can Value-Added Measures of Teacher Performance Be Trusted?

    ERIC Educational Resources Information Center

    Guarino, Cassandra M.; Reckase, Mark D.; Wooldridge, Jeffrey M.

    2015-01-01

    We investigate whether commonly used value-added estimation strategies produce accurate estimates of teacher effects under a variety of scenarios. We estimate teacher effects in simulated student achievement data sets that mimic plausible types of student grouping and teacher assignment scenarios. We find that no one method accurately captures…

  8. Reflectance Sensors: How Stable Are the Values They Measure?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reflectance sensors have been shown to be sensitive to the nitrogen status of crops. Systems using these sensors to control real-time variable-rate N fertilizer applications have been developed. For these systems to accurately diagnose the N rate needed, any shift in sensor value over short time per...

  9. Accounting for People: Can Business Measure Human Value?

    ERIC Educational Resources Information Center

    Workforce Economics, 1997

    1997-01-01

    Traditional business practice undervalues human capital, and most conventional accounting models reflect this inclination. The argument for more explicit measurements of human resources is simple: Improved measurement of human resources will lead to more rational and productive choices about managing human resources. The business community is…

  10. Quantifying the value of redundant measurements at GRUAN sites

    NASA Astrophysics Data System (ADS)

    Madonna, F.; Rosoldi, M.; Güldner, J.; Haefele, A.; Kivi, R.; Cadeddu, M. P.; Sisterson, D.; Pappalardo, G.

    2014-06-01

    The potential for measurement redundancy to reduce uncertainty in atmospheric variables has not been investigated comprehensively for climate observations. We evaluated the usefulness of entropy and mutual correlation concepts, as defined in information theory, for quantifying random uncertainty and redundancy in time series of atmospheric water vapor provided by five highly instrumented GRUAN (GCOS [Global Climate Observing System] Reference Upper-Air Network) Stations in 2010-2012. Results show that the random uncertainties for radiosonde, frost-point hygrometer, Global Positioning System, microwave and infrared radiometers, and Raman lidar measurements differed by less than 8%. Comparisons of time series of the Integrated Water Vapor (IWV) content from ground-based remote sensing instruments with in situ soundings showed that microwave radiometers have the highest redundancy and therefore the highest potential to reduce random uncertainty of IWV time series estimated by radiosondes. Moreover, the random uncertainty of a time series from one instrument should be reduced of ~ 60% by constraining the measurements with those from another instrument. The best reduction of random uncertainty resulted from conditioning of Raman lidar measurements with microwave radiometer measurements. Specific instruments are recommended for atmospheric water vapor measurements at GRUAN sites. This approach can be applied to the study of redundant measurements for other climate variables.

  11. Seeking value in Medicare: performance measurement for clinical professionals.

    PubMed

    Sprague, Lisa

    2013-10-30

    The Medicare program, despite its reputation of being a bill payer with little regard to the worth of the services it buys, has begun to put in place a range of programs aimed at assessing quality and value, with more to come. Attention to resource use and cost is nascent. The issues are complex, and it is no surprise that there is a level of contention between providers and regulators, even though both profess commitment to improved quality. This paper summarizes the quality and value programs that apply to physicians and other clinical professionals, as well as programs designed to encourage the adoption of technology to support quality improvement. Participation in all is voluntary. However, a decision not to participate increasingly carries a financial penalty, as Congress (and, by extension, the U.S. Department of Health and Human Services, or HHS) tries to encourage behavior it cannot force. PMID:24312987

  12. Liquid Hydrogen Absorber for MICE

    SciTech Connect

    Ishimoto, S.; Suzuki, S.; Yoshida, M.; Green, Michael A.; Kuno, Y.; Lau, Wing

    2010-05-30

    Liquid hydrogen absorbers for the Muon Ionization Cooling Experiment (MICE) have been developed, and the first absorber has been tested at KEK. In the preliminary test at KEK we have successfully filled the absorber with {approx}2 liters of liquid hydrogen. The measured hydrogen condensation speed was 2.5 liters/day at 1.0 bar. No hydrogen leakage to vacuum was found between 300 K and 20 K. The MICE experiment includes three AFC (absorber focusing coil) modules, each containing a 21 liter liquid hydrogen absorber made of aluminum. The AFC module has safety windows to separate its vacuum from that of neighboring modules. Liquid hydrogen is supplied from a cryocooler with cooling power 1.5 W at 4.2 K. The first absorber will be assembled in the AFC module and installed in MICE at RAL.

  13. [Measuring the intracoronary pressure gradient--value and methodologic limitations].

    PubMed

    Sievert, H; Kaltenbach, M

    1987-06-01

    Measurements of pressure gradients were performed in a fluid-filled model. The hydrostatically regulated perfusion pressure, as well as the diameter of the tube segments and the regulation of the flow by peripheral resistance, were comparable to conditions in human coronary arteries. Pressure gradients above 20 mm Hg were only measured with a reduction in cross-sectional area of more than 90%. Even after increasing the flow four-fold, which corresponds to the human coronary flow reserve, as well as after probing the stenosis with different catheters (2F-5F), gradients greater than 20 mm Hg were only recorded with high-grade stenoses (more than 80% reduction in cross-sectional area). The findings in this model demonstrate that measurement of pressure gradients allows only a quantitative differentiation between high-grade (greater than 80%) and low-grade (less than 80%) stenoses. The catheter itself can substantially contribute to the gradient by vessel obstruction, depending on the diameter of the catheter and of the coronary vessel. A quantitative assessment of the stenosis therefore requires knowledge of the pre- and post-stenotic vessel diameter as well as of the catheter diameter. However, pressure measurements during transluminal coronary angioplasty should not be abandoned. They can be useful to aid catheter positioning and to estimate dilatation efficacy. Moreover, measurement of coronary capillary wedge pressure during balloon expansion provides valuable information about the extent of collateralisation. PMID:2957862

  14. Temperature dependence of the absorbance of alkaline solutions of 4-nitrophenyl phosphate--a potential source of error in the measurement of alkaline phosphatase activity.

    PubMed

    Burtis, C A; Seibert, L E; Baird, M A; Sampson, E J

    1977-09-01

    The absorbance of an alkaline solution of 4-nitrophenyl phosphate is a function of temperature. Quantitative evaluation of this phenomenon indicates that it (a) depends on the concentration of the compound and is independent of source, buffer concentration, and pH above 9.0; (b) is reversible; (c) is not a result of alkaline hydrolysis or 4-nitrophenol contamination; and (d) correlates with a temperature-induced shift of its absorbance spectrum. The phenomenon may represent a potential analytical problem in methods for alkaline phosphatase in which this compound is the substrate. If thermal equilibrium is not reached and maintained during an alkaline phosphatase assay, the thermochromic response will be included in the measured rate. The magnitude of this error depends on the thermal response and control characteristics of each particular instrument and the reaction conditions under which such an analysis is performed. PMID:19164

  15. Direct measurement of absorbed dose to water in HDR {sup 192}Ir brachytherapy: Water calorimetry, ionization chamber, Gafchromic film, and TG-43

    SciTech Connect

    Sarfehnia, Arman; Kawrakow, Iwan; Seuntjens, Jan

    2010-04-15

    Purpose: Gafchromic film and ionometric calibration procedures for HDR {sup 192}Ir brachytherapy sources in terms of dose rate to water are presented and the experimental results are compared to the TG-43 protocol as well as with the absolute dose measurement results from a water calorimetry-based primary standard. Methods: EBT-1 Gafchromic films, an A1SL Exradin miniature Shonka thimble type chamber, and an SI HDR 1000 Plus well-type chamber (Standard Imaging, Inc., Middleton, WI) with an ADCL traceable S{sub k} calibration coefficient (following the AAPM TG-43 protocol) were used. The Farmer chamber and Gafchromic film measurements were performed directly in water. All results were compared to direct and absolute absorbed dose to water measurements from a 4 deg. C stagnant water calorimeter. Results: Based on water calorimetry, the authors measured the dose rate to water to be 361{+-}7 {mu}Gy/(h U) at a 55 mm source-to-detector separation. The dose rate normalized to air-kerma strength for all the techniques agree with the water calorimetry results to within 0.83%. The overall 1-sigma uncertainty on water calorimetry, ionization chamber, Gafchromic film, and TG-43 dose rate measurement amounts to 1.90%, 1.44%, 1.78%, and 2.50%, respectively. Conclusions: This work allows us to build a more realistic uncertainty estimate for absorbed dose to water determination using the TG-43 protocol. Furthermore, it provides the framework necessary for a shift from indirect HDR {sup 192}Ir brachytherapy dosimetry to a more accurate, direct, and absolute measurement of absorbed dose to water.

  16. High resolution redox potential measurements: techniques, interpretation and value

    NASA Astrophysics Data System (ADS)

    Vorenhout, Michel; van der Geest, Harm G.

    2013-04-01

    The ongoing improvement of techniques for the in situ measurement of redox potentials has led to a large number of studies on redox variability in various environments. These studies originate from a wide array of scientific disciplines, amongst which ecology (sediment biogeochemistry), environmental chemistry (degradation studies) and archaeology (in situ preservation). To gain insight in the potential applications, this paper presents three examples of studies in which a newly developed measurement technique was used in soils and where spatial and temporal variation plays an important role. The first one is a microcosm study on the effects of biota on the dynamics of redox conditions in the toplayer of aquatic sediments, showing that the presence of microbiota has a direct influence on biogeochemical parameters. The second is the study of the redox potential in the world heritage site of Bryggen (Bergen, NO) that is under threat of oxidation. The oxidation, caused by a lowered groundwater table, causes soil degradation and unstable conditions for the monumental buildings of the Medieval site. The third study shows variability in a sandy flood plain in Bangladesh, where redox processes dictate the environmental behaviour of Arsenic. This toxic metal is present in many wells used for drinking water, but shows very local variation in dissolution dynamics. In these three studies, continuous measurements of (changes in) redox conditions revealed a strong variability in these systems and consequences for the interpretation of single point measurements or low frequency sampling campaigns are discussed. In these and many other cases, the continuous measurement of the redox potential in soil media will aid in the understanding of the system under study.

  17. The impact of microwave absorber and radome geometries on GNSS measurements of station coordinates and atmospheric water vapour

    NASA Astrophysics Data System (ADS)

    Ning, T.; Elgered, G.; Johansson, J. M.

    2011-01-01

    We have used microwave absorbing material in different geometries around ground-based Global Navigation Satellite System (GNSS) antennas in order to mitigate multipath effects on the estimates of station coordinates and atmospheric water vapour. The influence of a hemispheric radome - of the same type as in the Swedish GPS network SWEPOS - was also investigated. Two GNSS stations at the Onsala Space Observatory were used forming a 12 m baseline. GPS data from October 2008 to November 2009 were analyzed by the GIPSY/OASIS II software using the Precise Point Positioning (PPP) processing strategy for five different elevation cutoff angles from 5° to 25°. We found that the use of the absorbing material decreases the offset in the estimated vertical component of the baseline from ˜27 mm to ˜4 mm when the elevation cutoff angle varies from 5° to 20°. The horizontal components are much less affected. The corresponding offset in the estimates of the atmospheric Integrated Water Vapour (IWV) decreases from ˜1.6 kg/m2 to ˜0.3 kg/m2. Changes less than 5 mm in the offsets in the vertical component of the baseline are seen for all five elevation cutoff angle solutions when the antenna was covered by a hemispheric radome. Using the radome affects the IWV estimates less than 0.4 kg/m2 for all different solutions. IWV comparisons between a Water Vapour Radiometer (WVR) and the GPS data give consistent results.

  18. Value measurement in health care: a new perspective.

    PubMed

    Michelman, J E; Rausch, P E; Barton, T L

    1999-08-01

    Vital to the success of any healthcare organization is the ability to obtain useful information and feedback about its performance. In particular, healthcare organizations need to begin to understand how non-value-adding work activities detract from their bottom lines. Additionally, financial managers and information systems need to provide data and reports throughout the continuum of care. Overall, healthcare organizations must align the management information and control systems with the planning and decision-making processes. The horizontal information system is a tool to manage three common problems facing today's healthcare managers: (1) the use of existing information to focus on control rather than improve business, (2) failure to focus on satisfying the customer, and (3) failure to combine their efforts with those of the employees by developing trust and a common focus. PMID:10557800

  19. Managing Complex IT Security Processes with Value Based Measures

    SciTech Connect

    Abercrombie, Robert K; Sheldon, Frederick T; Mili, Ali

    2009-01-01

    Current trends indicate that IT security measures will need to greatly expand to counter the ever increasingly sophisticated, well-funded and/or economically motivated threat space. Traditional risk management approaches provide an effective method for guiding courses of action for assessment, and mitigation investments. However, such approaches no matter how popular demand very detailed knowledge about the IT security domain and the enterprise/cyber architectural context. Typically, the critical nature and/or high stakes require careful consideration and adaptation of a balanced approach that provides reliable and consistent methods for rating vulnerabilities. As reported in earlier works, the Cyberspace Security Econometrics System provides a comprehensive measure of reliability, security and safety of a system that accounts for the criticality of each requirement as a function of one or more stakeholders interests in that requirement. This paper advocates a dependability measure that acknowledges the aggregate structure of complex system specifications, and accounts for variations by stakeholder, by specification components, and by verification and validation impact.

  20. ESTIMATED NEPTUNIUM SEDIMENT SORPTION VALUES AS A FUNCTION OF PH AND MEASURED BARIUM AND RADIUM KD VALUES

    SciTech Connect

    Kaplan, D.

    2011-01-13

    The objective of this document is to provide traceability and justification for a select few new geochemical data used in the Special Analysis entitled 'Special Analysis for the Dose Assessment of the Final Inventories in Center Slit Trenches One through Five'. Most values used in the Special Analysis came from the traditional geochemical data package, however, some recent laboratory measurements have made it possible to estimate barium K{sub d} values. Additionally, some recent calculations were made to estimate neptunium K{sub d} values as a function of pH. The assumptions, justifications, and calculations needed to generate these new values are presented in this document, and the values are summarized.

  1. Calibration method for a photoacoustic system for real time source apportionment of light absorbing carbonaceous aerosol based on size distribution measurements

    NASA Astrophysics Data System (ADS)

    Utry, Noemi; Ajtai, Tibor; Pinter, Mate; Orvos, Peter I.; Szabo, Gabor; Bozoki, Zoltan

    2016-04-01

    In this study, we introduce a calibration method with which sources of light absorbing carbonaceous particulate matter (LAC) can be apportioned in real time based on multi wavelength optical absorption measurements with a photoacoustic system. The method is primary applicable in wintry urban conditions when LAC is dominated by traffic and biomass burning. The proposed method was successfully tested in a field campaign in the city center of Szeged, Hungary during winter time where the dominance of traffic and wood burning aerosol has been experimentally demonstrated earlier. With the help of the proposed calibration method a relationship between the measured Aerosol Angström Exponent (AAE) and the number size distribution can be deduced. Once the calibration curve is determined, the relative strength of the two pollution sources can be deduced in real time as long as the light absorbing fraction of PM is exclusively related to traffic and wood burning. This assumption is indirectly confirmed in the presented measurement campaign by the fact that the measured size distribution is composed of two unimodal size distributions identified to correspond to traffic and wood burning aerosols. The proposed method offers the possibility of replacing laborious chemical analysis with simple in-situ measurement of aerosol size distribution data.

  2. Measuring the value of mortality risk reductions in Turkey.

    PubMed

    Tekeşin, Cem; Ara, Shihomi

    2014-07-01

    The willingness to pay (WTP) for mortality risk reduction from four causes (lung cancer, other type of cancer, respiratory disease, traffic accident) are estimated using random parameter logit model with data from choice experiment for three regions in Turkey. The value of statistical life (VSL) estimated for Afsin-Elbistan, Kutahya-Tavsanli, Ankara and the pooled case are found as 0.56, 0.35, 0.46 and 0.49 million Purchasing Power Parity (PPP) adjusted 2012 US dollars (USD). Different types of risk cause different VSL estimates and we found the lung cancer premium of 213% against traffic accident. The effects of one-year-delayed provision of risk-reduction service are the reduction of WTP by 482 TL ($318 in PPP adjusted USD) per person on average, and the disutility from status-quo (zero risk reduction) against alternative is found to be 891 TL ($589 in PPP adjusted USD) per person on average. Senior discounts of VSL are partially determined by status-quo preference and the amount of discount decreases once the status-quo bias is removed. The peak VSL is found to be for the age group 30-39 and the average VSL for the age group is 0.8 million PPP adjusted USD). Turkey's compliance to European Union (EU) air quality standard will cause welfare gains of total 373 million PPP adjusted USD for our study areas in terms of reduced number of premature mortality. PMID:25000150

  3. Measuring the Value of Mortality Risk Reductions in Turkey

    PubMed Central

    Tekeşin, Cem; Ara, Shihomi

    2014-01-01

    The willingness to pay (WTP) for mortality risk reduction from four causes (lung cancer, other type of cancer, respiratory disease, traffic accident) are estimated using random parameter logit model with data from choice experiment for three regions in Turkey. The value of statistical life (VSL) estimated for Afsin-Elbistan, Kutahya-Tavsanli, Ankara and the pooled case are found as 0.56, 0.35, 0.46 and 0.49 million Purchasing Power Parity (PPP) adjusted 2012 US dollars (USD). Different types of risk cause different VSL estimates and we found the lung cancer premium of 213% against traffic accident. The effects of one-year-delayed provision of risk-reduction service are the reduction of WTP by 482 TL ($318 in PPP adjusted USD) per person on average, and the disutility from status-quo (zero risk reduction) against alternative is found to be 891 TL ($589 in PPP adjusted USD) per person on average. Senior discounts of VSL are partially determined by status-quo preference and the amount of discount decreases once the status-quo bias is removed. The peak VSL is found to be for the age group 30–39 and the average VSL for the age group is 0.8 million PPP adjusted USD). Turkey’s compliance to European Union (EU) air quality standard will cause welfare gains of total 373 million PPP adjusted USD for our study areas in terms of reduced number of premature mortality. PMID:25000150

  4. The comparison of measured deformation indicators of mining area with theoretical values calculated using Knothe's formulas

    NASA Astrophysics Data System (ADS)

    Orwat, Justyna; Mielimaka, Ryszard

    2016-06-01

    The article demonstrates the comparison of prognosed values of deformation indicators with their values obtained from geodetic measurements. The value of correlation coefficient R between its theoretical and practical values was calculated for each indicator. Following the measured values as basic ones, the evaluation of efficiency of prognosis via the use of Knothe`s theory (a mathematical model, in which lowering of point is calculated as a double integral from Gauss error function with adequate parameters).

  5. Modified two-flux approximation for identification of radiative properties of absorbing and scattering media from directional-hemispherical measurements.

    PubMed

    Dombrovsky, Leonid; Randrianalisoa, Jaona; Baillis, Dominique

    2006-01-01

    A modified two-flux approximation is suggested for calculating the hemispherical transmittance and reflectance of a refracting, absorbing, and scattering medium in the case of collimated irradiation of the sample along the normal to the interface. The Fresnel reflection is taken into account in this approach. It is shown that the new approximation is rather accurate for the model transport scattering function. For an arbitrary scattering medium, the error of the modified two-flux approximation is estimated by comparison with the exact numerical calculations for the Henyey-Greenstein scattering function in a wide range of albedos and optical thicknesses. Possible applications of the derived analytical solution to identification problems are discussed. PMID:16478064

  6. Relating costs to the user value of farmland biodiversity measurements.

    PubMed

    Targetti, S; Herzog, F; Geijzendorffer, I R; Pointereau, P; Viaggi, D

    2016-01-01

    The impact of agricultural management on global biodiversity highlights the need for farm-scale monitoring programmes capable of determining the performance of agriculture practices. Yet the identification of appropriate indicators is a challenging process and one that involves considering a number of different aspects and requirements. Besides the attention given to scientific effectiveness, relevant but less studied issues related to biodiversity measurements include the economic feasibility of monitoring programmes and the relevance of indicators for different end-users. In this paper, we combine an analytic assessment of costs and a stakeholder-based evaluation of the usefulness of a set of biodiversity-related parameters (habitat mapping, vegetation, bees, earthworms, spiders, and a farmer questionnaire) tested for scientific consistency in 12 European case studies and on more than 14,000 ha of farmland. The results point to the possibility of meeting the expectations of different end-users (administrators, farmers and consumers) with a common indicator set. Combining costs and usefulness also suggests the possibility of designing more efficient monitoring approaches involving private agencies and networks of volunteers and farmers for the field data collection at different stages of a monitoring programme. Although complex, such an approach would make it possible to enhance the effectiveness of available funds for farmland biodiversity monitoring. PMID:26457535

  7. Measuring Children's Environmental Attitudes and Values in Northwest Mexico: Validating a Modified Version of Measures to Test the Model of Ecological Values (2-MEV)

    ERIC Educational Resources Information Center

    Schneller, A. J.; Johnson, B.; Bogner, F. X.

    2015-01-01

    This paper describes the validation process of measuring children's attitudes and values toward the environment within a Mexican sample. We applied the Model of Ecological Values (2-MEV), which has been shown to be valid and reliable in 20 countries, including one Spanish speaking culture. Items were initially modified to fit the regional…

  8. Examining the Perceived Value of Integration of Earned Value Management with Risk Management-Based Performance Measurement Baseline

    ERIC Educational Resources Information Center

    Shah, Akhtar H.

    2014-01-01

    Many projects fail despite the use of evidence-based project management practices such as Performance Measurement Baseline (PMB), Earned Value Management (EVM) and Risk Management (RM). Although previous researchers have found that integrated project management techniques could be more valuable than the same techniques used by themselves, these…

  9. Implementing Value-Added Measures of School Effectiveness: Getting the Incentives Right.

    ERIC Educational Resources Information Center

    Ladd, Helen F.; Walsh, Randall P.

    2002-01-01

    Evaluates value-added approach to measuring school effectiveness in North and South Carolina. Finds that value-added approach favors high-achievement schools, with large percentage of students from high-SES backgrounds. Discusses statistical problems in measuring value added. Concludes teachers' and administrators' avoidance of low-achievement,…

  10. Metasurface Broadband Solar Absorber

    DOE PAGESBeta

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-02-01

    Here, we demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Moreover, our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributionsmore » to elucidate how the absorption occurs within the metasurface structure.« less

  11. Metasurface Broadband Solar Absorber

    PubMed Central

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  12. Metasurface Broadband Solar Absorber

    NASA Astrophysics Data System (ADS)

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; Weisse-Bernstein, Nina R.; Luk, Ting S.; Taylor, Antoinette J.; Dalvit, Diego A. R.; Chen, Hou-Tong

    2016-02-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure.

  13. Metasurface Broadband Solar Absorber.

    PubMed

    Azad, Abul K; Kort-Kamp, Wilton J M; Sykora, Milan; Weisse-Bernstein, Nina R; Luk, Ting S; Taylor, Antoinette J; Dalvit, Diego A R; Chen, Hou-Tong

    2016-01-01

    We demonstrate a broadband, polarization independent, wide-angle absorber based on a metallic metasurface architecture, which accomplishes greater than 90% absorptance in the visible and near-infrared range of the solar spectrum, and exhibits low absorptivity (emissivity) at mid- and far-infrared wavelengths. The complex unit cell of the metasurface solar absorber consists of eight pairs of gold nano-resonators that are separated from a gold ground plane by a thin silicon dioxide spacer. Our experimental measurements reveal high-performance absorption over a wide range of incidence angles for both s- and p-polarizations. We also investigate numerically the frequency-dependent field and current distributions to elucidate how the absorption occurs within the metasurface structure. PMID:26828999

  14. Fock-state view of weak-value measurements and implementation with photons and atomic ensembles

    SciTech Connect

    Simon, Christoph; Polzik, Eugene S.

    2011-04-15

    Weak measurements in combination with postselection can give rise to a striking amplification effect (related to a large ''weak value''). We show that this effect can be understood by viewing the initial state of the pointer as the ground state of a fictional harmonic oscillator. This perspective clarifies the relationship between the weak-value regime and other measurement techniques and inspires a proposal to implement fully quantum weak-value measurements combining photons and atomic ensembles.

  15. Measuring daily Value-at-Risk of SSEC index: A new approach based on multifractal analysis and extreme value theory

    NASA Astrophysics Data System (ADS)

    Wei, Yu; Chen, Wang; Lin, Yu

    2013-05-01

    Recent studies in the econophysics literature reveal that price variability has fractal and multifractal characteristics not only in developed financial markets, but also in emerging markets. Taking high-frequency intraday quotes of the Shanghai Stock Exchange Component (SSEC) Index as example, this paper proposes a new method to measure daily Value-at-Risk (VaR) by combining the newly introduced multifractal volatility (MFV) model and the extreme value theory (EVT) method. Two VaR backtesting techniques are then employed to compare the performance of the model with that of a group of linear and nonlinear generalized autoregressive conditional heteroskedasticity (GARCH) models. The empirical results show the multifractal nature of price volatility in Chinese stock market. VaR measures based on the multifractal volatility model and EVT method outperform many GARCH-type models at high-risk levels.

  16. In situ UV-VIS-NIR absorbing properties of atmospheric aerosol particles: estimates of the imaginary refractive index and comparison with columnar values.

    PubMed

    Mogo, S; Cachorro, V E; de Frutos, A M

    2012-11-30

    In this work, a novel technique is used to estimate the aerosol complex index of refraction of in situ collected samples. Samples of atmospheric particulate matter were collected in El Arenosillo, southern Spain, on polycarbonate filters during summer 2004 as part of an aerosol characterization campaign. These samples were analyzed for the volumetric absorption coefficient in the 320-800 nm spectral region and an estimation of the effective imaginary refractive index was made. The values of the imaginary part of the complex refractive index ranged between 0.0009-0.0215 at 800 nm and 0.0015-0.0114 at 320 nm. Little dependence on the wavelength was observed. Several intense and long lasting desert outbreaks were registered during the campaign and the complex refractive index almost doubles its value during these dust events. Finally, we present a comparison of data obtained in situ with columnar data obtained from the AERONET network. A correlation factor of 0.64 was obtained between both data, which gives an idea of how accurately the in situ ground data represent the total column. PMID:22964016

  17. PHITS simulations of the Protective curtain experiment onboard the Service module of ISS: Comparison with absorbed doses measured with TLDs

    NASA Astrophysics Data System (ADS)

    Ploc, Ondřej; Sihver, Lembit; Kartashov, Dmitry; Shurshakov, Vyacheslav; Tolochek, Raisa

    2013-12-01

    "Protective curtain" was the physical experiment onboard the International Space Station (ISS) aimed on radiation measurement of the dose - reducing effect of the additional shielding made of hygienic water-soaked wipes and towels placed on the wall in the crew cabin of the Service module Zvezda. The measurements were performed with 12 detector packages composed of thermoluminescent detectors (TLDs) and plastic nuclear track detectors (PNTDs) placed at the Protective curtain, so that they created pairs of shielded and unshielded detectors.

  18. Hyperuniformity of critical absorbing states.

    PubMed

    Hexner, Daniel; Levine, Dov

    2015-03-20

    The properties of the absorbing states of nonequilibrium models belonging to the conserved directed percolation universality class are studied. We find that, at the critical point, the absorbing states are hyperuniform, exhibiting anomalously small density fluctuations. The exponent characterizing the fluctuations is measured numerically, a scaling relation to other known exponents is suggested, and a new correlation length relating to this ordering is proposed. These results may have relevance to photonic band-gap materials. PMID:25839254

  19. Hyperuniformity of Critical Absorbing States

    NASA Astrophysics Data System (ADS)

    Hexner, Daniel; Levine, Dov

    2015-03-01

    The properties of the absorbing states of nonequilibrium models belonging to the conserved directed percolation universality class are studied. We find that, at the critical point, the absorbing states are hyperuniform, exhibiting anomalously small density fluctuations. The exponent characterizing the fluctuations is measured numerically, a scaling relation to other known exponents is suggested, and a new correlation length relating to this ordering is proposed. These results may have relevance to photonic band-gap materials.

  20. Fluorescence spectroscopy: considerations for highly absorbing dissolved organic matter samples

    NASA Astrophysics Data System (ADS)

    Simone, B. E.; Miller, M.; McKnight, D. M.

    2009-12-01

    Fluorescence spectroscopy is a robust method for characterizing organic matter (OM). However, proper collection and correction of spectra are necessary to provide useful data. One important correction is the inner-filter correction, which primarily accounts for the inner-filter effect by adjusting for the wavelength dependent attenuation of emitted light by the solution prior to detection by the fluorometer. The most commonly used correction is based on an assumption that light is emitted at the center of the pathlength. Thus, the inner-filter effect is more pronounced in highly absorbing samples, and has the potential to skew the fluorescence spectra. For this study, the terrestrially derived Suwannee River fulvic acid (SRFA) and microbially derived Pony Lake fulvic acid (PLFA), from the International Humic Substances Society (IHSS), were diluted to incremental absorbances at a wavelength of 254 nm from 0.05 to 1.0 at pH 4 and 7. Three dimensional fluorescence spectra were measured and modeled with the Cory and McKnight (2005) parallel factor analysis (PARAFAC) model which resolves the fluorescence spectra into 13 components, including quinone-like and protein-like components. In the absence of inner-filter effects, plots of absorbance vs. loadings should be linear. Using the data from absorbance of 0.05 to 0.3, where the inner-filter affect is least pronounced, a linear regression was created and used as a baseline to predict component loadings at higher absorbance values in the absence of inner-filter effects. Results indicate that at absorbance values greater than 0.3, the commonly-used inner-filter correction is not able to remove the inner-filter effect. Therefore, in order to obtain reliable component loadings and correctly interpret the spectra, samples should be diluted to absorbance values less than 0.3 at 254 nm prior to collection of three dimensional fluorescence scans. The recommendation of a maximum absorbance of 0.3 agrees with the results of a

  1. Measurement of absorbed doses from X-ray baggage examinations to tooth enamel by means of ESR and glass dosimetry.

    PubMed

    Zhumadilov, Kassym; Stepanenko, Valeriy; Ivannikov, Alexander; Zhumadilov, Zhaxybay; Zharlyganova, Dinara; Toyoda, Shin; Tanaka, Kenichi; Endo, Satoru; Hoshi, Masaharu

    2008-11-01

    The contribution of radiation from X-ray baggage scans at airports on dose formation in tooth samples was investigated by electron spin resonance (ESR) dosimetry and by glass dosimetry. This was considered important, because tooth samples from population around the Semipalatinsk Nuclear Test Site (SNTS), Kazakhstan, had been transported in the past to Hiroshima University for retrospective dose assessment of these residents. Enamel samples and glass dosimeters were therefore examined at check-in time at Kansai airport (Osaka, Japan), Dubai airport (Dubai, United Arab Emirates) and Domodedovo airport (Moscow, Russia). These airports are on the route from Kazakhstan to Japan. Three different potential locations of the samples were investigated: in pocket (without X-ray scans), in a small bag (with four X-ray scans) and in large luggage (with two X-ray scans). The doses obtained by glass and ESR dosimetry methods were cross-compared. As expected, doses from X-ray examinations measured by glass dosimetry were in the microGy range, well below the ESR detection limit and also below the doses measured in enamel samples from residents of the SNTS. PMID:18648837

  2. Measuring the Variability of Data from Other Values in the Set

    ERIC Educational Resources Information Center

    Jones, Dustin L.; Scariano, Stephen M.

    2014-01-01

    Students have intuitive notions of the meaning of variability; some may see variability as how values in a set vary from each other. This article provides a measure of variability that is based on that conception. We introduce this new measure and a method for calculating it. Finally, we prove that this measure is equivalent to the population…

  3. Value, Impact, and the Transcendent Library: Progress and Pressures in Performance Measurement and Evaluation

    ERIC Educational Resources Information Center

    Town, J. Stephen

    2011-01-01

    Libraries are under pressure to prove their worth and may not have achieved this fully successfully. There is a resultant growing requirement for value and impact measurement in academic and research libraries. This essay reviews the natural history of library performance measurement and suggests that proof of worth will be measured by the…

  4. Patients’ perceived value of pharmacy quality measures: a mixed-methods study

    PubMed Central

    Shiyanbola, Olayinka O; Mort, Jane R

    2015-01-01

    Objective To describe patients’ perceived value and use of quality measures in evaluating and choosing community pharmacies. Design Focus group methodology was combined with a survey tool. During the focus groups, participants assessed the value of the Pharmacy Quality Alliance's quality measures in evaluating and choosing a pharmacy. Also, participants completed questionnaires rating their perceived value of quality measures in evaluating a pharmacy (1 being low value and 5 being high) or choosing a pharmacy (yes/no). Thematic analysis and descriptive statistics were used to analyse the focus groups and surveys, respectively. Setting Semistructured focus groups were conducted in a private meeting space of an urban and a rural area of a Mid-western State in the USA. Participants Thirty-four adults who filled prescription medications in community pharmacies for a chronic illness were recruited in community pharmacies, senior centres and public libraries. Results While comments indicated that all measures were important, medication safety measures (eg, drug-drug interactions) were valued more highly than others. Rating of quality measure utility in evaluating a pharmacy ranged from a mean of 4.88 (‘drug-drug interactions’) to a mean of 4.0 (‘absence of controller therapy for patients with asthma’). Patients were hesitant to use quality information in choosing a pharmacy (depending on the participant's location) but might consider if moving to a new area or having had a negative pharmacy experience. Use of select quality measures to choose a pharmacy ranged from 97.1% of participants using ‘drug-drug interactions’ (medication safety measure) to 55.9% using ‘absence of controller therapy for patients with asthma’. Conclusions The study participants valued quality measures in evaluating and selecting a community pharmacy, with medication safety measures valued highest. The participants reported that the quality measures would not typically cause a

  5. AN INDEPENDENT MEASUREMENT OF THE INCIDENCE OF Mg II ABSORBERS ALONG GAMMA-RAY BURST SIGHT LINES: THE END OF THE MYSTERY?

    SciTech Connect

    Cucchiara, A.; Prochaska, J. X.; Fynbo, J. P. U.; Fox, D. B.; Chen, H.-W.; Cooksey, K. L.; Cenko, S. B.; Bloom, J. S.; Perley, D.; Berger, E.; Chornock, R.; Tanvir, N. R.; D'Elia, V.; Lopez, S.; De Jaeger, T.

    2013-08-20

    In 2006, Prochter et al. reported a statistically significant enhancement of very strong Mg II absorption systems intervening the sight lines to gamma-ray bursts (GRBs) relative to the incidence of such absorption along quasar sight lines. This counterintuitive result has inspired a diverse set of astrophysical explanations (e.g., dust, gravitational lensing) but none of these has obviously resolved the puzzle. Using the largest set of GRB afterglow spectra available, we reexamine the purported enhancement. In an independent sample of GRB spectra with a survey path three times larger than Prochter et al., we measure the incidence per unit redshift of {>=}1 A rest-frame equivalent width Mg II absorbers at z Almost-Equal-To 1 to be l(z) = 0.18 {+-} 0.06. This is fully consistent with current estimates for the incidence of such absorbers along quasar sight lines. Therefore, we do not confirm the original enhancement and suggest those results suffered from a statistical fluke. Signatures of the original result do remain in our full sample (l(z) shows an Almost-Equal-To 1.5 enhancement over l(z){sub QSO}), but the statistical significance now lies at Almost-Equal-To 90% c.l. Restricting our analysis to the subset of high-resolution spectra of GRB afterglows (which overlaps substantially with Prochter et al.), we still reproduce a statistically significant enhancement of Mg II absorption. The reason for this excess, if real, is still unclear since there is no connection between the rapid afterglow follow-up process with echelle (or echellette) spectrographs and the detectability of strong Mg II doublets. Only a larger sample of such high-resolution data will shed some light on this matter.

  6. Different Tests, Different Answers: The Stability of Teacher Value-Added Estimates across Outcome Measures

    ERIC Educational Resources Information Center

    Papay, John P.

    2011-01-01

    Recently, educational researchers and practitioners have turned to value-added models to evaluate teacher performance. Although value-added estimates depend on the assessment used to measure student achievement, the importance of outcome selection has received scant attention in the literature. Using data from a large, urban school district, I…

  7. Method and apparatus for real-time measurement of fuel gas compositions and heating values

    DOEpatents

    Zelepouga, Serguei; Pratapas, John M.; Saveliev, Alexei V.; Jangale, Vilas V.

    2016-03-22

    An exemplary embodiment can be an apparatus for real-time, in situ measurement of gas compositions and heating values. The apparatus includes a near infrared sensor for measuring concentrations of hydrocarbons and carbon dioxide, a mid infrared sensor for measuring concentrations of carbon monoxide and a semiconductor based sensor for measuring concentrations of hydrogen gas. A data processor having a computer program for reducing the effects of cross-sensitivities of the sensors to components other than target components of the sensors is also included. Also provided are corresponding or associated methods for real-time, in situ determination of a composition and heating value of a fuel gas.

  8. Sensitivity, specificity, and predictive values of a forearm blood pressure measurement method in severe obesity.

    PubMed

    Leblanc, Marie-Ève; Cloutier, Lyne; Poirier, Paul

    2015-04-01

    For blood pressure assessment, it has been reported that forearm blood pressure measurement appears to be as valid as an upper-arm blood pressure measurement method in individuals with severe obesity when correlated to the intra-arterial method, considered as the gold standard. Sensitivity, specificity, and predictive values for the presence of systemic hypertension in 25 severely obese patients from 352 blood pressure measurements were calculated. The sensitivity (0.98) and the positive predictive value (0.93) for hypertension on forearm blood pressure measurements are excellent, indicating that the forearm approach is a promising alternative to systemic hypertension diagnosis in severe obesity. PMID:25757220

  9. Composition for absorbing hydrogen

    DOEpatents

    Heung, L.K.; Wicks, G.G.; Enz, G.L.

    1995-05-02

    A hydrogen absorbing composition is described. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  10. Composition for absorbing hydrogen

    DOEpatents

    Heung, Leung K.; Wicks, George G.; Enz, Glenn L.

    1995-01-01

    A hydrogen absorbing composition. The composition comprises a porous glass matrix, made by a sol-gel process, having a hydrogen-absorbing material dispersed throughout the matrix. A sol, made from tetraethyl orthosilicate, is mixed with a hydrogen-absorbing material and solidified to form a porous glass matrix with the hydrogen-absorbing material dispersed uniformly throughout the matrix. The glass matrix has pores large enough to allow gases having hydrogen to pass through the matrix, yet small enough to hold the particles dispersed within the matrix so that the hydrogen-absorbing particles are not released during repeated hydrogen absorption/desorption cycles.

  11. Consistency between Self-Reported and Recorded Values for Clinical Measures

    PubMed Central

    III, Joseph Thomas; Paulet, Mindy; Rajpura, Jigar R.

    2016-01-01

    Objectives. This study evaluated consistency between self-reported values for clinical measures and recorded clinical measures. Methods. Self-reported values were collected for the clinical measures: systolic blood pressure, diastolic blood pressure, glucose level, height, weight, and cholesterol from health risk assessments completed by enrollees in a privately insured cohort. Body mass index (BMI) was computed from reported height and weight. Practitioner recorded values for the clinical measures were obtained from health screenings. We used bivariate Pearson correlation analysis and descriptive statistics to evaluate consistency between self-reported data and recorded clinic measurements. Results. There was high correlation between self-reported clinical values and recorded clinical measures for diastolic blood pressure (r = 0.91, P = <0.0001), systolic blood pressure (r = 0.93, P = <0.0001), cholesterol (r = 0.97, P = <0.0001), body mass index (r = 0.96, P = <0.0001), glucose (r = 0.96, P = <0.0001), weight (r = 0.98, P = <0.0001), and height (r = 0.89, P = <0.0001). Conclusions. Self-reported clinical values for each of the eight clinical measures examined had good consistency with practitioner recorded data. PMID:26942034

  12. A review of measurement and modeling of Light-absorbing Particles in Snow and Ice and their climatic and hydrological impact

    NASA Astrophysics Data System (ADS)

    Qian, Y.; Doherty, S. J.; Lau, W. K. M.; Ming, J.; Wang, H.; Warren, S. G.; Yasunari, T. J.; Zhang, R.; Flanner, M.

    2015-12-01

    Light absorbing particles (LAP, e.g., black carbon, brown carbon, and dust) influence water and energy budgets of the atmosphere and snowpack in multiple ways. In addition to their effects associated with atmospheric heating by absorption of solar radiation and interactions with clouds, LAP in snow on land and ice can reduce the surface reflectance , which is likely to accelerate the snow aging process and further reduces snow albedo and increases the speed of snowpack melt. LAP in snow and ice (LAPSI) has been identified as one of major forcings affecting climate change, e.g. in the fourth and fifth assessment reports of IPCC. However, the uncertainty level in quantifying this effect remains very high. In this talk, we document various technical methods of measuring LAPSI and review the progress made in measuring the LAPSI in Arctic, Tibetan Plateau and other mid-latitude regions. We also report the progress in modeling the concentrations, albedo reduction, radiative forcing, and climatic and hydrological impact of LAPSI at global and regional scales. Finally we identify some research needs for reducing the uncertainties in the impact of LAPSI on global and regional climate and the hydrological cycle.

  13. Inferring Absorbing Organic Carbon Content from AERONET Data

    NASA Technical Reports Server (NTRS)

    Arola, A.; Schuster, G.; Myhre, G.; Kazadzis, S.; Dey, S.; Tripathi, S. N.

    2011-01-01

    Black carbon, light-absorbing organic carbon (often called brown carbon) and mineral dust are the major light-absorbing aerosols. Currently the sources and formation of brown carbon aerosol in particular are not well understood. In this study we estimated globally the amount of light absorbing organic carbon and black carbon from AERONET measurements. We find that the columnar absorbing organic carbon (brown carbon) levels in biomass burning regions of South-America and Africa are relatively high (about 15-20 magnesium per square meters during biomass burning season), while the concentrations are significantly lower in urban areas in US and Europe. However, we estimated significant absorbing organic carbon amounts from the data of megacities of newly industrialized countries, particularly in India and China, showing also clear seasonality with peak values up to 30-35 magnesium per square meters during the coldest season, likely caused by the coal and biofuel burning used for heating. We also compared our retrievals with the modeled organic carbon by global Oslo CTM for several sites. Model values are higher in biomass burning regions than AERONET-based retrievals, while opposite is true in urban areas in India and China.

  14. Value-Added Measures for Schools in England: Looking inside the "Black Box" of Complex Metrics

    ERIC Educational Resources Information Center

    Kelly, Anthony; Downey, Christopher

    2010-01-01

    Value-added measures can be used to allocate funding to schools, to identify those institutions in need of special attention and to underpin government guidance on targets. In England, there has been a tendency to include in these measures an ever-greater number of contextualising variables and to develop ever-more complex models that encourage…

  15. Using Value-Added Models to Measure Teacher Effects on Students' Motivation and Achievement

    ERIC Educational Resources Information Center

    Ruzek, Erik A.; Domina, Thurston; Conley, AnneMarie M.; Duncan, Greg J.; Karabenick, Stuart A.

    2015-01-01

    Value-added (VA) models measure teacher contributions to student learning and are increasingly employed in educational reform efforts. Using data from 35 seventh-grade teachers and 2,026 students across seven schools, we employ VA methods to measure teacher contributions to students' motivational orientations (mastery and performance achievement…

  16. Airborne aldehydes in cabin-air of commercial aircraft: Measurement by HPLC with UV absorbance detection of 2,4-dinitrophenylhydrazones.

    PubMed

    Rosenberger, Wolfgang; Beckmann, Bibiana; Wrbitzky, Renate

    2016-04-15

    This paper presents the strategy and results of in-flight measurements of airborne aldehydes during normal operation and reported "smell events" on commercial aircraft. The aldehyde-measurement is a part of a large-scale study on cabin-air quality. The aims of this study were to describe cabin-air quality in general and to detect chemical abnormalities during the so-called "smell-events". Adsorption and derivatization of airborne aldehydes on 2,4-dinitrophenylhydrazine coated silica gel (DNPH-cartridge) was applied using tailor-made sampling kits. Samples were collected with battery supplied personal air sampling pumps during different flight phases. Furthermore, the influence of ozone was investigated by simultaneous sampling with and without ozone absorption unit (ozone converter) assembled to the DNPH-cartridges and found to be negligible. The method was validated for 14 aldehydes and found to be precise (RSD, 5.5-10.6%) and accurate (recovery, 98-103 %), with LOD levels being 0.3-0.6 μg/m(3). According to occupational exposure limits (OEL) or indoor air guidelines no unusual or noticeable aldehyde pollution was observed. In total, 353 aldehyde samples were taken from two types of aircraft. Formaldehyde (overall average 5.7 μg/m(3), overall median 4.9 μg/m(3), range 0.4-44 μg/m(3)), acetaldehyde (overall average 6.5 μg/m(3), overall median 4.6, range 0.3-90 μg/m(3)) and mostly very low concentrations of other aldehydes were measured on 108 flights. Simultaneous adsorption and derivatization of airborne aldehydes on DNPH-cartridges to the Schiff bases and their HPLC analysis with UV absorbance detection is a useful method to measure aldehydes in cabin-air of commercial aircraft. PMID:26376451

  17. Atmospheric Radiation Measurement (ARM) Value-Added Data Products (Including Evaluated Data Sets)

    DOE Data Explorer

    Many of the scientific needs of the ARM Program are met through the analysis and processing of existing data products into "value-added" products or VAPs. Despite extensive instrumentation deployed at the ARM sites, there will always be quantities of interest that are either impractical or impossible to measure directly or routinely. Physical models using ARM instrument data as inputs are implemented as VAPs and can help fill some of the unmet measurement needs of the Program. Conversely, ARM produces some VAPs not in order to fill unmet measurement needs, but instead to improve the quality of existing measurements. In addition, when more than one measurement is available, ARM also produces "best estimate" VAPs. A special class of VAP called a Quality Measurement Experiment (QME) adds value to the input data streams by providing for continuous assessment of the quality of the input data. [taken from http://www.arm.gov/data/vaps_all.php] One of the ARM data centers, the External Data Center or XDC at Brookhaven National Laboratory, also adds value to ARM information by identifying sources and acquiring external data to augment the data being generated within the program. These external data sets are converted, processed, and carefully evaluated for their value to the overall ARM program. /. Data Plots are also value-added products from ARM.

  18. Delta K measurements with synthetic aperture radar data. [micirowavelength difference values

    NASA Technical Reports Server (NTRS)

    Larson, R. W.; Jackson, P. L.; Klooster, A.

    1985-01-01

    Delta K measurements are obtained from the interference of two electromagnetic waves of different frequencies. Constructive interference occurs when 2pi phase differences between the two frequencies correspond to a surface wavelength. Previous Delta K measurements have used two discrete frequencies for this purpose. Range pulses and Doppler signatures of a synthetic aperture radar system were filtered to obtain a sequence of Delta K values. Those Delta K values which correspond to the wavelengths of known surfaces show maximum constructive interference. SAR data can therefore be used for Delta K measurements, indicating the possibility of selective Delta K filtering during data gathering.

  19. Value-based performance measures for Hanford Tank Waste Remedition System (TWRS) Program

    SciTech Connect

    Keeney, R.L.; von Winterfeldt, D.

    1996-01-01

    The Tank Waste Remediation Systems (TWRS) Program is responsible for the safe storage, retrieval, treatment, and preparation for disposal of high-level waste currently stored in underground storage tanks at the Hanford site in Richland. The TWRS program has adopted a logical approach to decision making that is based on systems engineering and decision analysis (Westinghouse Hanford Company, 1995). This approach involves the explicit consideration of stakeholder values and an evaluation of the TWRS alternatives in terms of these values. Such evaluations need to be consistent across decisions. Thus, an effort was undertaken to develop a consistent, quantifiable set of measures that can be used by TVVRS to assess alternatives against the stakeholder values. The measures developed also met two additional requirements: 1) the number of measure should be relatively small; and 2) performance with respect to the measures should be relatively easy to estimate.

  20. The VALS: A new tool to measure people's general valued attributes of landscapes.

    PubMed

    Kendal, Dave; Ford, Rebecca M; Anderson, Nerida M; Farrar, Alison

    2015-11-01

    Research on values for natural areas has largely focussed on theoretical concerns such as distinguishing different kinds of values held by people. However practice, policymaking, planning and management is typically focused on more tangible valued attributes of the landscape such as biodiversity and recreation infrastructure that can be manipulated by management actions. There is a need for valid psychometric measures of such values that are suited to informing land management policies. A Valued Attributes of Landscape Scale (VALS) was developed, derived from a document analysis of values expressed in public land policy documents. The validity of the VALS was tested in an online survey comparing values across one of three randomly presented landscape contexts in Victoria, Australia: all publicly managed natural land, coastal areas, and large urban parks. A purposive snowball sample was used to recruit participants with a range of views and professional experience with land management, including members of the urban public. Factor analysis of responses (n = 646) separated concepts relating to natural attributes, social functions, the experience of being in natural areas, cultural attributes and productive uses. Relative importance of valued attribute factors was similar across all landscape contexts, although there were small but significant differences in the way people valued social functions (higher in urban parks) and productive uses (lower in urban parks). We conclude that the concept of valued attributes is useful for linking theoretical understandings of people's environmental values to the way values are considered by land managers, and that these attributes can be measured using the VALS instrument to produce data that should be useful for the policy and planning of natural resources. PMID:26321532

  1. On set-valued functionals: Multivariate risk measures and Aumann integrals

    NASA Astrophysics Data System (ADS)

    Ararat, Cagin

    In this dissertation, multivariate risk measures for random vectors and Aumann integrals of set-valued functions are studied. Both are set-valued functionals with values in a complete lattice of subsets of Rm. Multivariate risk measures are considered in a general d-asset financial market with trading opportunities in discrete time. Specifically, the following features of the market are incorporated in the evaluation of multivariate risk: convex transaction costs modeled by solvency regions, intermediate trading constraints modeled by convex random sets, and the requirement of liquidation into the first m ≤ d of the assets. It is assumed that the investor has a "pure" multivariate risk measure R on the space of m-dimensional random vectors which represents her risk attitude towards the assets but does not take into account the frictions of the market. Then, the investor with a d-dimensional position minimizes the set-valued functional R over all m-dimensional positions that she can reach by trading in the market subject to the frictions described above. The resulting functional Rmar on the space of d-dimensional random vectors is another multivariate risk measure, called the market-extension of R. A dual representation for R mar that decomposes the effects of R and the frictions of the market is proved. Next, multivariate risk measures are studied in a utility-based framework. It is assumed that the investor has a complete risk preference towards each individual asset, which can be represented by a von Neumann-Morgenstern utility function. Then, an incomplete preference is considered for multivariate positions which is represented by the vector of the individual utility functions. Under this structure, multivariate shortfall and divergence risk measures are defined as the optimal values of set minimization problems. The dual relationship between the two classes of multivariate risk measures is constructed via a recent Lagrange duality for set optimization. In

  2. Precise Penning trap measurements of double β-decay Q-values

    NASA Astrophysics Data System (ADS)

    Redshaw, M.; Brodeur, M.; Bollen, G.; Bustabad, S.; Eibach, M.; Gulyuz, K.; Izzo, C.; Lincoln, D. L.; Novario, S. J.; Ringle, R.; Sandler, R.; Schwarz, S.; Valverde, A. A.

    2015-10-01

    The double β-decay (ββ -decay) Q-value, defined as the mass difference between parent and daughter atoms, is an important parameter for both two-neutrino ββ -decay (2 νββ) and neutrinoless ββ -decay (0 νββ) experiments. The Q-value enters into the calculation of the phase space factors, which relate the measured ββ -decay half-life to the nuclear matrix element and, in the case of 0 νββ , the effective Majorana mass of the neutrino. In addition, the Q-value defines the total kinetic energy of the two electrons emitted in 0 νββ , corresponding to the location of the single peak that is the sought after signature of 0 νββ . Hence, it is essential to have a precise and accurate Q-value determination. Over the last decade, the Penning trap mass spectrometry community has made a significant effort to provide precise ββ -decay Q-value determinations. Here we report on recent measurements with the Low Energy Beam and Ion Trap (LEBIT) facility at the National Superconducting Cyclotron Laboratory (NSCL) of the 48Ca, 82Se, and 96Zr Q-values. These measurements complete the determination of ββ -decay Q-values for the 11 ``best'' candidates (those with Q >2 MeV). We also report on a measurement of the 78Kr double electron capture (2EC) Q-value and discuss ongoing Penning trap measurements relating to ββ -decay and 2EC. Support from NSF Contract No. PHY-1102511, and DOE Grant No. 03ER-41268.

  3. Disturbance in weak measurements and the difference between quantum and classical weak values

    NASA Astrophysics Data System (ADS)

    Ipsen, Asger C.

    2015-06-01

    The role of measurement-induced disturbance in weak measurements is of central importance for the interpretation of the weak value. Uncontrolled disturbance can interfere with the postselection process and make the weak value dependent on the details of the measurement process. Here we develop the concept of a generalized weak measurement for classical and quantum mechanics. The two cases appear remarkably similar, but we point out some important differences. A priori it is not clear what the correct notion of disturbance should be in the context of weak measurements. We consider three different notions and get three different results: (1) For a "strong" definition of disturbance, we find that weak measurements are disturbing. (2) For a weaker definition we find that a general class of weak measurements is nondisturbing, but that one gets weak values which depend on the measurement process. (3) Finally, with respect to an operational definition of the "degree of disturbance," we find that the AAV weak measurements are the least disturbing, but that the disturbance is always nonzero.

  4. In-Situ Measurements of U-Values and Thermal Performance of Windows.

    SciTech Connect

    Klems, Joseph H.; Keller, H.

    1987-04-01

    Five commercial windows were studied using the MoWiTT (Mobile Window Thermal Test) facility, an accurate new field test apparatus. Both overall diurnal performance and U-values were measured. The latter were compared to test laboratory hot box measurements for the same five windows, and to calculations made with the program WINDOW-2.0. Calculations, MoWiTT and hot box measurements agreed for three of the windows; for one of the others, the calculations agreed with the MoWiTT measurement but not with the hot box. For the fifth, a low-E window, the calculations may be made to agree with either measurement but not both, depending on assumptions about the frame. The authors suggest a possible explanation for the conflict, and advance an interpretation of the data which would allow a consistent understanding of calculated, field and laboratory U-values. In the studies of overall performance, uncertainties arising from wintertime solar gain were found to overshadow the differences in U-value for all window orientations, including north-facing. In some of the windows tested, improved U-values were offset by decreased solar gain acceptance. Further research is suggested to achieve a method of evaluating overall window energy performance which would reliably reflect U-value improvements. 5 refs., 36 figs., 13 tabs.

  5. A summary of the measured pK values of the ionizable groups in folded proteins.

    PubMed

    Grimsley, Gerald R; Scholtz, J Martin; Pace, C Nick

    2009-01-01

    We tabulated 541 measured pK values reported in the literature for the Asp, Glu, His, Cys, Tyr, and Lys side chains, and the C and N termini of 78 folded proteins. The majority of these values are for the Asp, Glu, and His side chains. The average pK values are Asp 3.5 +/- 1.2 (139); Glu 4.2 +/- 0.9 (153); His 6.6 +/- 1.0 (131); Cys 6.8 +/- 2.7 (25); Tyr 10.3 +/- 1.2 (20); Lys 10.5 +/- 1.1 (35); C-terminus 3.3 +/- 0.8 (22) and N-terminus 7.7 +/- 0.5 (16). We compare these results with the measured pK values of these groups in alanine pentapeptides, and comment on our overall findings. PMID:19177368

  6. Modelling Absorbent Phenomena of Absorbent Structure

    NASA Astrophysics Data System (ADS)

    Sayeb, S.; Ladhari, N.; Ben Hassen, M.; Sakli, F.

    Absorption, retention and strike through time, as evaluating criteria of absorbent structures quality were studied. Determination of influent parameters on these criteria were realized by using the design method of experimental sets. In this study, the studied parameters are: Super absorbent polymer (SAP)/fluff ratio, compression and the porosity of the non woven used as a cover stock. Absorption capacity and retention are mostly influenced by SAP/fluff ratio. However, strike through time is affected by compression. Thus, a modelling of these characteristics in function of the important parameter was established.

  7. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P.; Longhurst, Glen R.; Porter, Douglas L.; Parry, James R.

    2012-07-24

    A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

  8. Externally tuned vibration absorber

    DOEpatents

    Vincent, Ronald J.

    1987-09-22

    A vibration absorber unit or units are mounted on the exterior housing of a hydraulic drive system of the type that is powered from a pressure wave generated, e.g., by a Stirling engine. The hydraulic drive system employs a piston which is hydraulically driven to oscillate in a direction perpendicular to the axis of the hydraulic drive system. The vibration absorbers each include a spring or other resilient member having one side affixed to the housing and another side to which an absorber mass is affixed. In a preferred embodiment, a pair of vibration absorbers is employed, each absorber being formed of a pair of leaf spring assemblies, between which the absorber mass is suspended.

  9. The measured energy value of pistachio nuts in the human diet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have suggested that lipid from nuts is more poorly absorbed than that from other food sources. If lipid from nuts is poorly absorbed, then the metabolizable energy contained in the nuts is less than that predicted by the Atwater general factor for fat of 37 kJ(9 kcal)/g. A crossov...

  10. Echocardiographic measurements in the Irish wolfhound: reference values for the breed.

    PubMed

    Vollmar, A C

    1999-01-01

    Out of 400 Irish wolfhounds cardiologically examined, echocardiographic measurements of 262 normal dogs were analyzed to obtain reference values for the breed. Based on regression analysis, several echocardiographic parameters showed significant linear correlation with body weight and with age, but coefficients of determination were low. Therefore, due to a high individual variability of echocardiographic measurements in adult Irish wolfhounds, the predictive value of body weight for echocardiographic measurements was clinically not relevant. Sex had no influence on echocardiographic values. For the estimation of myocardial function, end-systolic volume index (ESVI) (mean, 29.0 ml/m2 +/- standard deviation [SD], 5.9 ml/m2) was determined for the group of 262 normal dogs. PMID:10416769

  11. [Gas Concentration Measurement Based on the Integral Value of Absorptance Spectrum].

    PubMed

    Liu, Hui-jun; Tao, Shao-hua; Yang, Bing-chu; Deng, Hong-gui

    2015-12-01

    The absorptance spectrum of a gas is the basis for the qualitative and quantitative analysis of the gas by the law of the Lambert-Beer. The integral value of the absorptance spectrum is an important parameter to describe the characteristics of the gas absorption. Based on the measured absorptance spectrum of a gas, we collected the required data from the database of HIT-RAN, and chose one of the spectral lines and calculated the integral value of the absorptance spectrum in the frequency domain, and then substituted the integral value into Lambert-Beer's law to obtain the concentration of the detected gas. By calculating the integral value of the absorptance spectrum we can avoid the more complicated calculation of the spectral line function and a series of standard gases for calibration, so the gas concentration measurement will be simpler and faster. We studied the changing trends of the integral values of the absorptance spectrums versus temperature. Since temperature variation would cause the corresponding variation in pressure, we studied the changing trends of the integral values of the absorptance spectrums versus both the pressure not changed with temperature and changed with the temperature variation. Based on the two cases, we found that the integral values of the absorptance spectrums both would firstly increase, then decrease, and finally stabilize with temperature increasing, but the ranges of specific changing trend were different in the two cases. In the experiments, we found that the relative errors of the integrated values of the absorptance spectrum were much higher than 1% and still increased with temperature when we only considered the change of temperature and completely ignored the pressure affected by the temperature variation, and the relative errors of the integrated values of the absorptance spectrum were almost constant at about only 1% when we considered that the pressure were affected by the temperature variation. As the integral value

  12. How Can Value-Added Measures Be Used for Teacher Improvement? What We Know Series: Value-Added Methods and Applications. Knowledge Brief 13

    ERIC Educational Resources Information Center

    Loeb, Susanna

    2013-01-01

    The question for this brief is whether education leaders can use value-added measures as tools for improving schooling and, if so, how to do this. Districts, states, and schools can, at least in theory, generate gains in educational outcomes for students using value-added measures in three ways: creating information on effective programs, making…

  13. Craniofacial skeletal measurements based on computed tomography: Part II. Normal values and growth trends.

    PubMed

    Waitzman, A A; Posnick, J C; Armstrong, D C; Pron, G E

    1992-03-01

    Current diagnosis and surgical correction of craniofacial anomalies would benefit from accurate quantitative and standardized points of reference. A retrospective study was undertaken to define normal values for a series of craniofacial measurements and to evaluate the growth patterns of the craniofacial complex through axial computed tomography (CT). Fifteen measurements were taken from 542 CT scan series of skeletally normal subjects. The measurement values were then divided into 1-year age categories from 1 to 17 years, and into four age groups for those under 1 year of age. The normal range and growth pattern of measurement values for the cranial vault, orbital region, and upper midface are presented. The overall size of the cranio-orbito-zygomatic skeleton reaches more than 85 percent of adult size by age 5 years. The cranial vault grows rapidly in the first year of life but growth levels off early. The upper midface grows at a slower rate in infancy, but continues to grow later in childhood and early adolescence. Knowledge of the differential growth patterns and normal measurement values in the craniofacial region will help improve diagnostic accuracy, staging of reconstruction, precision of corrective surgery, and follow-up of patients. PMID:1571345

  14. On the acoustics of rocket combustors equipped with quarter wave absorbers

    NASA Astrophysics Data System (ADS)

    Oschwald, M.; Marpert, M.

    2011-10-01

    The acoustic resonance spectrum and the dissipation of specific modes in combustors equipped with absorbers have been investigated experimentally and numerically. It is found that the application of absorber rings to a combustor changes its resonance behavior significantly. Based on the acoustic fields obtained by three-dimensional (3D) modal analysis, the damping behavior for modes is predicted and compared to measurements. There is a good agreement between prediction and experimental data with respect to the general trend of the dependence of damping on the absorber length. However, the experimentally determined dissipation rates are significantly larger than the predicted values.

  15. Informational power of the Hoggar symmetric informationally complete positive operator-valued measure

    NASA Astrophysics Data System (ADS)

    Szymusiak, Anna; Słomczyński, Wojciech

    2016-07-01

    We compute the informational power for the Hoggar symmetric informationally complete positive operator-valued measure (SIC-POVM) in dimension eight, i.e., the classical capacity of a quantum-classical channel generated by this measurement. We show that the states constituting a maximally informative ensemble form a twin Hoggar SIC-POVM being the image of the original one under a conjugation.

  16. Magnetic field effects on microwave absorbing materials

    NASA Technical Reports Server (NTRS)

    Goldberg, Ira; Hollingsworth, Charles S.; Mckinney, Ted M.

    1991-01-01

    The objective of this program was to gather information to formulate a microwave absorber that can work in the presence of strong constant direct current (DC) magnetic fields. The program was conducted in four steps. The first step was to investigate the electrical and magnetic properties of magnetic and ferrite microwave absorbers in the presence of strong magnetic fields. This included both experimental measurements and a literature survey of properties that may be applicable to finding an appropriate absorbing material. The second step was to identify those material properties that will produce desirable absorptive properties in the presence of intense magnetic fields and determine the range of magnetic field in which the absorbers remain effective. The third step was to establish ferrite absorber designs that will produce low reflection and adequate absorption in the presence of intense inhomogeneous static magnetic fields. The fourth and final step was to prepare and test samples of such magnetic microwave absorbers if such designs seem practical.

  17. Precision QEC-value measurement of 23Mg for testing the CKM matrix unitarity

    NASA Astrophysics Data System (ADS)

    Brodeur, Maxime; Schultz, Brad; Dilling, Jens; Titan Collaboration

    2014-09-01

    We report a new direct measurement of the 23Mg β+-decay transition energy QEC using the TITAN Penning trap mass spectrometer. This value agrees with the latest atomic mass evaluation while being four times more precise. The increase in precision changes the uncertainty contribution of the QEC-value on the statistical rate function fv from 11 % to 0.6 %, an improvement by a factor of 18. This enables a more robust determination of the corrected Ft -value of this mirror transition to the required precision, making possible further test of the CKM matrix unitarity. We report a new direct measurement of the 23Mg β+-decay transition energy QEC using the TITAN Penning trap mass spectrometer. This value agrees with the latest atomic mass evaluation while being four times more precise. The increase in precision changes the uncertainty contribution of the QEC-value on the statistical rate function fv from 11 % to 0.6 %, an improvement by a factor of 18. This enables a more robust determination of the corrected Ft -value of this mirror transition to the required precision, making possible further test of the CKM matrix unitarity. Natural Sciences and Engineering Research Council of Canada.

  18. Acoustical model of a Shoddy fibre absorber

    NASA Astrophysics Data System (ADS)

    Manning, John Peter

    ) Characterization testing yields specific values for intrinsic material parameters that allow for comparison to other porous materials. Individual parameter relations allow users to substitute measured or theoretical values as needed. A new empirical acoustical model is proposed to describe the behaviour of Shoddy-based fibre absorbers. The model requires knowledge of the bulk density only. This parameter is easily measured making application of the model elementary. Mots-clés : Shoddy, porous, fibre, recycled, absorption, model, acoustic.

  19. Using neural measures of economic value to solve the public goods free-rider problem.

    PubMed

    Krajbich, Ian; Camerer, Colin; Ledyard, John; Rangel, Antonio

    2009-10-23

    Every social group needs to decide when to provide public goods and how to allocate the costs among its members. Ideally, this decision would maximize the group's net benefits while also ensuring that every individual's benefit is greater than the cost he or she has to pay. Unfortunately, the economic theory of mechanism design has shown that this ideal solution is not feasible when the group leadership does not know the values of the individual group members for the public good. We show that this impossibility result can be overcome in laboratory settings by combining technologies for obtaining neural measures of value (functional magnetic resonance imaging-based pattern classification) with carefully designed institutions that allocate costs based on both reported and neurally measured values. PMID:19745115

  20. Advanced neutron absorber materials

    DOEpatents

    Branagan, Daniel J.; Smolik, Galen R.

    2000-01-01

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  1. Sentinels Guarding the Grail: Value-Added Measurement and the Quest for Education Reform

    ERIC Educational Resources Information Center

    Gabriel, Rachael; Lester, Jessica Nina

    2013-01-01

    Since the beginning of the federal Race To The Top grant competition, Value-Added Measurement (VAM) has captured the attention of the American public through high-profile media representations of the tool and the controversy that surrounds it. In this paper, we build upon investigations of constructions of VAM in the media and present a discourse…

  2. 42 CFR 412.164 - Measure selection under the Hospital Value-Based Purchasing (VBP) Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Measure selection under the Hospital Value-Based Purchasing (VBP) Program. 412.164 Section 412.164 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM PROSPECTIVE PAYMENT SYSTEMS FOR INPATIENT HOSPITAL SERVICES Adjustments to the...

  3. Value-Added Measures in Education: What Every Educator Needs to Know

    ERIC Educational Resources Information Center

    Harris, Douglas N.

    2011-01-01

    In "Value-Added Measures in Education", Douglas N. Harris takes on one of the most hotly debated topics in education. Drawing on his extensive work with schools and districts, he sets out to help educators and policymakers understand this innovative approach to assessment and the issues associated with its use. Written in straightforward language…

  4. Measuring Staff Perceptions of University Identity and Activities: The Mission and Values Inventory

    ERIC Educational Resources Information Center

    Ferrari, Joseph R.; Velcoff, Jessica

    2006-01-01

    Higher education institutions need to ascertain whether their stakeholders understand the school's mission, vision, and values. In the present study, the psychometric properties of a mission identity and activity measure were investigated with two staff samples. Using a principal component factor analysis (varimax rotation), respondents in Sample…

  5. Start a New Fire: Measuring the Value of Academic Libraries in Undergraduate Learning

    ERIC Educational Resources Information Center

    Menchaca, Frank

    2014-01-01

    In the last two decades, fundamental changes in information distribution, in the general economy, and in the behaviors of faculty, students, and library staff have problematized the question of an academic library's value and how it can be measured. This article reviews those changes and, drawing on research linked to the Collegiate Learning…

  6. Measuring the Value of Succession Planning and Management: A Qualitative Study of Multinational Companies

    ERIC Educational Resources Information Center

    Kim, Yeonsoo

    2010-01-01

    This article proposes a model for planning and operating an effective succession planning and management (SP&M) program and measuring its value. The nature of the research is exploratory, following a qualitative approach using in-depth interviews. Representatives of multinational companies interviewed for this study revealed that succession…

  7. Measuring Teacher Effectiveness Using Value-Added Models of High School Achievement

    ERIC Educational Resources Information Center

    Gawade, Nandita G.; Meyer, Robert H.

    2016-01-01

    This article uses empirical data to consider the consequences of particular characteristics of instruction and testing in high school for the modeling and estimation of value-added measures of school or teacher effectiveness. Unlike Mathematics and Reading for most elementary and middle school grades, there is a lack of annual testing of students…

  8. Refining the Measure and Dimensions of Social Values of Older People (SVOP)

    ERIC Educational Resources Information Center

    Yoon, Eunkyung; Kolomer, Stacey R.

    2007-01-01

    Older persons are living longer and healthier and, thus, are capable of being more productive and less dependent. Despite this trend, young people persistently hold the age-old negative stereotypes about older persons. The goals of this study were to develop a valid, reliable measure of social values of older people and to assess its utility as…

  9. An evaluation of a new instrument to measure organisational safety culture values and practices.

    PubMed

    Díaz-Cabrera, D; Hernández-Fernaud, E; Isla-Díaz, R

    2007-11-01

    The main aim of this research is to evaluate a safety culture measuring instrument centred upon relevant organisational values and practices related to the safety management system. Seven dimensions that reflect underlying safety meanings are proposed. A second objective is to explore the four cultural orientations in the field of safety arising from the competing values framework. The study sample consisted of 299 participants from five companies in different sectors. The results show six dimensions of organisational values and practices and different company profiles in the organisations studied. The four cultural orientations proposed by the competing values framework are not confirmed. Nevertheless, a coexistence of diverse cultural orientations or paradoxes in the companies is observed. PMID:17920844

  10. Two-qubit Bell inequality for which positive operator-valued measurements are relevant

    SciTech Connect

    Vertesi, T.; Bene, E.

    2010-12-15

    A bipartite Bell inequality is derived which is maximally violated on the two-qubit state space if measurements describable by positive operator valued measure (POVM) elements are allowed, rather than restricting the possible measurements to projective ones. In particular, the presented Bell inequality requires POVMs in order to be maximally violated by a maximally entangled two-qubit state. This answers a question raised by N. Gisin [in Quantum Reality, Relativistic Causality, and Closing the Epistemic Circle: Essays in Honour of Abner Shimony, edited by W. C. Myrvold and J. Christian (Springer, The Netherlands, 2009), pp. 125-138].

  11. Behavioral Economic Measures of Alcohol Reward Value as Problem Severity Indicators in College Students

    PubMed Central

    Skidmore, Jessica R.; Murphy, James G.; Martens, Matthew P.

    2014-01-01

    The aims of the current study were to examine the associations among behavioral economic measures of alcohol value derived from three distinct measurement approaches, and to evaluate their respective relations with traditional indicators of alcohol problem severity in college drinkers. Five behavioral economic metrics were derived from hypothetical demand curves that quantify reward value by plotting consumption and expenditures as a function of price, another metric measured proportional behavioral allocation and enjoyment related to alcohol versus other activities, and a final metric measured relative discretionary expenditures on alcohol. The sample included 207 heavy drinking college students (53% female) who were recruited through an on-campus health center or university courses. Factor analysis revealed that the alcohol valuation construct comprises two factors: one factor that reflects participants’ levels of alcohol price sensitivity (demand persistence), and a second factor that reflects participants’ maximum consumption and monetary and behavioral allocation towards alcohol (amplitude of demand). The demand persistence and behavioral allocation metrics demonstrated the strongest and most consistent multivariate relations with alcohol-related problems, even when controlling for other well-established predictors. The results suggest that behavioral economic indices of reward value show meaningful relations with alcohol problem severity in young adults. Despite the presence of some gender differences, these measures appear to be useful problem indicators for men and women. PMID:24749779

  12. The transmission color value: a novel egg quality measure for recording shell color used for monitoring the stress and health status of a brown layer flock.

    PubMed

    Mertens, K; Vaesen, I; Loffel, J; Kemps, B; Kamers, B; Perianu, C; Zoons, J; Darius, P; Decuypere, E; De Baerdemaeker, J; De Ketelaere, B

    2010-03-01

    Stress and diseases have the potential to influence the deposition of eggshell pigmentation during egg formation. Therefore, defining the shell color of eggs on a daily basis could be a representative method for monitoring stress or health status of a flock and maintaining good performance. A novel way of measuring eggshell color based on visible-near infrared transmission spectroscopy transmission spectra was defined: the transmission color value (TCV). The TCV was calculated as the ratio between the transmission at 643 nm (maximum absorbance of the pigmentation molecule protoporphyrin IX) and the transmission at 610 nm (a reference wavelength). Experiments were carried out to investigate the relevance of TCV for monitoring flock stress and health or even anticipating any factors unfavorable to performance. In 2 small experimental flocks, deliberate heat stress challenges were applied. A medium-scale experimental flock in an aviary was monitored on a daily basis during the whole productive period. From the deliberate heat stress challenges, it was seen that stress had a significant effect on eggshell pigmentation. This observation was confirmed in a daily monitored flock, in which, for example, an infectious bronchitis infection occurred. These stress situations were quickly reflected by an increased TCV value: more transmission due to less pigmentation and hence less absorbance at the pigmentation wavelength. Furthermore, for the observed problems in the daily monitoring, the TCV value signaled the problem earlier (4 d) than the average egg weight or even signaled when the other parameters did not signal anything. Measuring the TCV of all eggs produced on a daily basis provides relevant information on the stress or health status of a flock of brown layers. This could be used as an early detection of stress situations or emerging diseases, even before important quality and health damage can occur. PMID:20181881

  13. The QCRad Value Added Product: Surface Radiation Measurement Quality Control Testing, Including Climatology Configurable Limits

    SciTech Connect

    Long, CN; Shi, Y

    2006-09-01

    This document describes the QCRad methodology, which uses climatological analyses of the surface radiation measurements to define reasonable limits for testing the data for unusual data values. The main assumption is that the majority of the climatological data are “good” data, which for field sites operated with care such as those of the Atmospheric Radiation Measurement (ARM) Program is a reasonable assumption. Data that fall outside the normal range of occurrences are labeled either “indeterminate” (meaning that the measurements are possible, but rarely occurring, and thus the values cannot be identified as good) or “bad” depending on how far outside the normal range the particular data reside. The methodology not only sets fairly standard maximum and minimum value limits, but also compares what we have learned about the behavior of these instruments in the field to other value-added products (VAPs), such as the Diffuse infrared (IR) Loss Correction VAP (Younkin and Long 2004) and the Best Estimate Flux VAP (Shi and Long 2002).

  14. Measuring the value of groundwater and other forms of natural capital

    PubMed Central

    Fenichel, Eli P.; Abbott, Joshua K.; Bayham, Jude; Boone, Whitney; Haacker, Erin M. K.; Pfeiffer, Lisa

    2016-01-01

    Valuing natural capital is fundamental to measuring sustainability. The United Nations Environment Programme, World Bank, and other agencies have called for inclusion of the value of natural capital in sustainability metrics, such as inclusive wealth. Much has been written about the importance of natural capital, but consistent, rigorous valuation approaches compatible with the pricing of traditional forms of capital have remained elusive. We present a guiding quantitative framework enabling natural capital valuation that is fully consistent with capital theory, accounts for biophysical and economic feedbacks, and can guide interdisciplinary efforts to measure sustainability. We illustrate this framework with an application to groundwater in the Kansas High Plains Aquifer, a rapidly depleting asset supporting significant food production. We develop a 10-y time series (1996−2005) of natural capital asset prices that accounts for technological, institutional, and physical changes. Kansas lost approximately $110 million per year (2005 US dollars) of capital value through groundwater withdrawal and changes in aquifer management during the decade spanning 1996–2005. This annual loss in wealth is approximately equal to the state’s 2005 budget surplus, and is substantially more than investments in schools over this period. Furthermore, real investment in agricultural capital also declined over this period. Although Kansas’ depletion of water wealth is substantial, it may be tractably managed through careful groundwater management and compensating investments in other natural and traditional assets. Measurement of natural capital value is required to inform management and ongoing investments in natural assets. PMID:26858431

  15. Measuring the value of groundwater and other forms of natural capital.

    PubMed

    Fenichel, Eli P; Abbott, Joshua K; Bayham, Jude; Boone, Whitney; Haacker, Erin M K; Pfeiffer, Lisa

    2016-03-01

    Valuing natural capital is fundamental to measuring sustainability. The United Nations Environment Programme, World Bank, and other agencies have called for inclusion of the value of natural capital in sustainability metrics, such as inclusive wealth. Much has been written about the importance of natural capital, but consistent, rigorous valuation approaches compatible with the pricing of traditional forms of capital have remained elusive. We present a guiding quantitative framework enabling natural capital valuation that is fully consistent with capital theory, accounts for biophysical and economic feedbacks, and can guide interdisciplinary efforts to measure sustainability. We illustrate this framework with an application to groundwater in the Kansas High Plains Aquifer, a rapidly depleting asset supporting significant food production. We develop a 10-y time series (1996-2005) of natural capital asset prices that accounts for technological, institutional, and physical changes. Kansas lost approximately $110 million per year (2005 US dollars) of capital value through groundwater withdrawal and changes in aquifer management during the decade spanning 1996-2005. This annual loss in wealth is approximately equal to the state's 2005 budget surplus, and is substantially more than investments in schools over this period. Furthermore, real investment in agricultural capital also declined over this period. Although Kansas' depletion of water wealth is substantial, it may be tractably managed through careful groundwater management and compensating investments in other natural and traditional assets. Measurement of natural capital value is required to inform management and ongoing investments in natural assets. PMID:26858431

  16. Weak values and weak coupling maximizing the output of weak measurements

    SciTech Connect

    Di Lorenzo, Antonio

    2014-06-15

    In a weak measurement, the average output 〈o〉 of a probe that measures an observable A{sup -hat} of a quantum system undergoing both a preparation in a state ρ{sub i} and a postselection in a state E{sub f} is, to a good approximation, a function of the weak value A{sub w}=Tr[E{sub f}A{sup -hat} ρ{sub i}]/Tr[E{sub f}ρ{sub i}], a complex number. For a fixed coupling λ, when the overlap Tr[E{sub f}ρ{sub i}] is very small, A{sub w} diverges, but 〈o〉 stays finite, often tending to zero for symmetry reasons. This paper answers the questions: what is the weak value that maximizes the output for a fixed coupling? What is the coupling that maximizes the output for a fixed weak value? We derive equations for the optimal values of A{sub w} and λ, and provide the solutions. The results are independent of the dimensionality of the system, and they apply to a probe having a Hilbert space of arbitrary dimension. Using the Schrödinger–Robertson uncertainty relation, we demonstrate that, in an important case, the amplification 〈o〉 cannot exceed the initial uncertainty σ{sub o} in the observable o{sup -hat}, we provide an upper limit for the more general case, and a strategy to obtain 〈o〉≫σ{sub o}. - Highlights: •We have provided a general framework to find the extremal values of a weak measurement. •We have derived the location of the extremal values in terms of preparation and postselection. •We have devised a maximization strategy going beyond the limit of the Schrödinger–Robertson relation.

  17. [Absorbed doses in dental radiology].

    PubMed

    Bianchi, S D; Roccuzzo, M; Albrito, F; Ragona, R; Anglesio, S

    1996-01-01

    The growing use of dento-maxillo-facial radiographic examinations has been accompanied by the publication of a large number of studies on dosimetry. A thorough review of the literature is presented in this article. Most studies were carried out on tissue equivalent skull phantoms, while only a few were in vivo. The aim of the present study was to evaluate in vivo absorbed doses during Orthopantomography (OPT). Full Mouth Periapical Examination (FMPE) and Intraoral Tube Panoramic Radiography (ITPR). Measurements were made on 30 patients, reproducing clinical conditions, in 46 anatomical sites, with 24 intra- and 22 extra-oral thermoluminiscent dosimeters (TLDS). The highest doses were measured, in orthopantomography, at the right mandibular angle (1899 mu Gy) in FMPE on the right naso-labial fold (5640 mu Gy and in ITPR on the palatal surface of the left second upper molar (1936 mu Gy). Intraoral doses ranged from 21 mu Gy, in orthopantomography, to 4494 mu Gy in FMPE. Standard errors ranged from 142% in ITPR to 5% in orthopantomography. The highest rate of standard errors was found in FMPE and ITPR. The data collected in this trial are in agreement with others in major literature reports. Disagreements are probably due to different exam acquisition and data collections. Such differences, presented comparison in several sites, justify lower doses in FMPE and ITPR. Advantages and disadvantages of in vivo dosimetry of the maxillary region are discussed, the former being a close resemblance to clinical conditions of examination and the latter the impossibility of collecting values in depth of tissues. Finally, both ITPR and FMPE required lower doses than expected, and can be therefore reconsidered relative to their radiation risk. PMID:8966249

  18. A Research on Performance Measurement Based on Economic Valued-Added Comprehensive Scorecard

    NASA Astrophysics Data System (ADS)

    Chen, Qin; Zhang, Xiaomei

    With the development of economic, the traditional performance mainly rely on financial indicators could not satisfy the need of work. In order to make the performance measurement taking the best services for business goals, this paper proposed Economic Valued-Added Comprehensive Scorecard based on research of shortages and advantages of EVA and BSC .We used Analytic Hierarchy Process to build matrix to solve the weighting of EVA Comprehensive Scorecard. At last we could find the most influence factors for enterprise value forming the weighting.

  19. Strength Measurements in Acute Hamstring Injuries: Intertester Reliability and Prognostic Value of Handheld Dynamometry.

    PubMed

    Reurink, Gustaaf; Goudswaard, Gert Jan; Moen, Maarten H; Tol, Johannes L; Verhaar, Jan A N; Weir, Adam

    2016-08-01

    Study Design Cohort study, repeated measures. Background Although hamstring strength measurements are used for assessing prognosis and monitoring recovery after hamstring injury, their actual clinical relevance has not been established. Handheld dynamometry (HHD) is a commonly used method of measuring muscle strength. The reliability of HHD has not been determined in athletes with acute hamstring injuries. Objectives To determine the intertester reliability and the prognostic value of hamstring HHD strength measurement in acute hamstring injuries. Methods We measured knee flexion strength with HHD in 75 athletes at 2 visits, at baseline (within 5 days of hamstring injury) and follow-up (5 to 7 days after the baseline measurement). We assessed isometric hamstring strength in 15° and 90° of knee flexion. Reliability analysis testing was performed by 2 testers independently at the follow-up visit. We recorded the time needed to return to play (RTP) up to 6 months following baseline. Results The intraclass correlation coefficients of the strength measurements in injured hamstrings were between 0.75 and 0.83. There was a statistically significant but weak correlation between the time to RTP and the strength deficit at 15° of knee flexion measured at baseline (Spearman r = 0.25, P = .045) and at the follow-up visit (Spearman r = 0.26, P = .034). Up to 7% of the variance in time to RTP is explained by this strength deficit. None of the other strength variables were significantly correlated with time to RTP. Conclusion Hamstring strength can be reliably measured with HHD in athletes with acute hamstring injuries. The prognostic value of strength measurements is limited, as there is only a weak association between the time to RTP and hamstring strength deficit after acute injury. Level of Evidence Prognosis, level 4. J Orthop Sports Phys Ther 2016;46(8):689-696. Epub 12 May 2016. doi:10.2519/jospt.2016.6363. PMID:27170527

  20. Internal absorber solar collector

    DOEpatents

    Sletten, Carlyle J.; Herskovitz, Sheldon B.; Holt, F. S.; Sletten, E. J.

    1981-01-01

    Thin solar collecting panels are described made from arrays of small rod collectors consisting of a refracting dielectric rod lens with an absorber imbedded within it and a reflecting mirror coated on the back side of the dielectric rod. Non-tracking collector panels on vertical walls or roof tops receive approximately 90% of solar radiation within an acceptance zone 60.degree. in elevation angle by 120.degree. or more in the azimuth sectors with a collector concentration ratio of approximately 3.0. Miniaturized construction of the circular dielectric rods with internal absorbers reduces the weight per area of glass, plastic and metal used in the collector panels. No external parts or insulation are needed as heat losses are low due to partial vacuum or low conductivity gas surrounding heated portions of the collector. The miniature internal absorbers are generally made of solid copper with black selective surface and the collected solar heat is extracted at the collector ends by thermal conductivity along the absorber rods. Heat is removed from end fittings by use of liquid circulants. Several alternate constructions are provided for simplifying collector panel fabrication and for preventing the thermal expansion and contraction of the heated absorber or circulant tubes from damaging vacuum seals. In a modified version of the internal absorber collector, oil with temperature dependent viscosity is pumped through a segmented absorber which is now composed of closely spaced insulated metal tubes. In this way the circulant is automatically diverted through heated portions of the absorber giving higher collector concentration ratios than theoretically possible for an unsegmented absorber.

  1. Metal shearing energy absorber

    NASA Technical Reports Server (NTRS)

    Fay, R. J.; Wittrock, E. P. (Inventor)

    1973-01-01

    A metal shearing energy absorber is described. The absorber is composed of a flat thin strip of metal which is pulled through a slot in a cutter member of a metal, harder than the metal of the strip. The slot's length, in the direction perpendicular to the pull direction, is less than the strip's width so that as the strip is pulled through the slot, its edges are sheared off, thereby absorbing some of the pulling energy. In one embodiment the cutter member is a flat plate of steel, while in another embodiment the cutter member is U-shaped with the slot at its base.

  2. Lipid-absorbing Polymers

    NASA Technical Reports Server (NTRS)

    Marsh, H. E., Jr.; Wallace, C. J.

    1973-01-01

    The removal of bile acids and cholesterol by polymeric absorption is discussed in terms of micelle-polymer interaction. The results obtained with a polymer composed of 75 parts PEO and 25 parts PB plus curing ingredients show an absorption of 305 to 309%, based on original polymer weight. Particle size effects on absorption rate are analyzed. It is concluded that crosslinked polyethylene oxide polymers will absorb water, crosslinked polybutadiene polymers will absorb lipids; neither polymer will absorb appreciable amounts of lipids from micellar solutions of lipids in water.

  3. The relationship between inferior vena cava diameter measured by bedside ultrasonography and central venous pressure value

    PubMed Central

    Citilcioglu, Serenat; Sebe, Ahmet; Oguzhan Ay, Mehmet; Icme, Ferhat; Avci, Akkan; Gulen, Muge; Sahan, Mustafa; Satar, Salim

    2014-01-01

    Objective: We aimed to present inferior vena cava (IVC) diameter as a guiding method for detection of relationship between IVC diameter measured noninvasively with the help of ultrasonography (USG) and central venous pressure (CVP) and evaluation of patient's intravascular volume status. Methods: Patients over the age of 18, to whom a central venous catheter was inserted to their subclavian vein or internal jugular vein were included in our study. IVC diameter measurements were recorded in millimeters following measurement by the same clinician with the help of USG both at the end-inspiratory and end-expiratory phase. CVP measurements were viewed on the monitor by means of piezoelectric transducer and recorded in mmHg. SPSS 18.0 package program was used for statistical analysis of data. Results: Forty five patients were included in the study. The patients had the diagnosis of malignancy (35.6%), sepsis (13.3%), pneumonia, asthma, chronic obstructive pulmonary disease (11.1%). 11 patients (24.4%) required mechanical ventilation while 34 (75.6%) patients had spontaneous respiration. In patients with spontaneous respiration, a significant relationship was found between IVC diameters measured by ultrasonography at the end of expiratory and inspiratory phases and measured CVP values at the same phases (for expiratory p = 0.002, for inspiratory p= 0.001). There was no statistically significant association between IVC diameters measured by ultrasonography at the end of expiration and inspiration and measured CVP values at the same phases in mechanically ventilated patients. Conclusions: IVC diameter measured by bedside ultrasonography can be used for determination of the intravascular volume status of the patients with spontaneous respiration. PMID:24772133

  4. Measuring Value Added in Higher Education: A Proposed Methodology for Developing a Performance Indicator Based on the Economic Value Added to Graduates

    ERIC Educational Resources Information Center

    Rodgers, Timothy

    2007-01-01

    The 2003 UK higher education White Paper suggested that the sector needed to re-examine the potential of the value added concept. This paper describes a possible methodology for developing a performance indicator based on the economic value added to graduates. The paper examines how an entry-quality-adjusted measure of a graduate's "expected"…

  5. Review and assessment of measured values of the nonlinear refractive-index coefficient of fused silica

    SciTech Connect

    Milam, D.

    1998-01-01

    The literature describes more than 30 measurements, at wavelengths between 249 and 1550 nm, of the absolute value of the nonlinear refractive-index coefficient of fused silica. Results of these experiments were assessed and best currently available values were selected for the wavelengths of 351, 527, and 1053 nm. The best values are (3.6{plus_minus}0.64){times}10{sup {minus}16} cm{sup 2}/W at 351 nm, (3.0{plus_minus}0.35){times}10{sup {minus}16} cm{sup 2}/W at 527 nm, and (2.74{plus_minus}0.17){times}10{sup {minus}16} cm{sup 2}/W at 1053 nm. {copyright} 1998 Optical Society of America

  6. Detection of Organic Compounds in Water by an Optical Absorbance Method

    PubMed Central

    Kim, Chihoon; Eom, Joo Beom; Jung, Soyoun; Ji, Taeksoo

    2016-01-01

    This paper proposes an optical method which allows determination of the organic compound concentration in water by measurement of the UV (ultraviolet) absorption at a wavelength of 250 nm~300 nm. The UV absorbance was analyzed by means of a multiple linear regression model for estimation of the total organic carbon contents in water, which showed a close correlation with the UV absorbance, demonstrating a high adjusted coefficient of determination, 0.997. The comparison of the TOC (total organic carbon) concentrations for real samples (tab water, sea, and river) calculated from the UV absorbance spectra, and those measured by a conventional TOC analyzer indicates that the higher the TOC value the better the agreement. This UV absorbance method can be easily configured for real-time monitoring water pollution, and built into a compact system applicable to industry areas. PMID:26742043

  7. Detection of Organic Compounds in Water by an Optical Absorbance Method.

    PubMed

    Kim, Chihoon; Eom, Joo Beom; Jung, Soyoun; Ji, Taeksoo

    2016-01-01

    This paper proposes an optical method which allows determination of the organic compound concentration in water by measurement of the UV (ultraviolet) absorption at a wavelength of 250 nm~300 nm. The UV absorbance was analyzed by means of a multiple linear regression model for estimation of the total organic carbon contents in water, which showed a close correlation with the UV absorbance, demonstrating a high adjusted coefficient of determination, 0.997. The comparison of the TOC (total organic carbon) concentrations for real samples (tab water, sea, and river) calculated from the UV absorbance spectra, and those measured by a conventional TOC analyzer indicates that the higher the TOC value the better the agreement. This UV absorbance method can be easily configured for real-time monitoring water pollution, and built into a compact system applicable to industry areas. PMID:26742043

  8. Direct mass measurements of cadmium and palladium isotopes and their double-β transition Q values

    NASA Astrophysics Data System (ADS)

    Smorra, C.; Beyer, T.; Blaum, K.; Block, M.; Düllmann, Ch. E.; Eberhardt, K.; Eibach, M.; Eliseev, S.; Nagy, Sz.; Nörtershäuser, W.; Renisch, D.

    2012-02-01

    The Q value of the double-electron capture in 108Cd has been determined to be (272.04 ± 0.55) keV in a direct measurement with the double-Penning trap mass spectrometer TRIGA-TRAP. Based on this result a resonant enhancement of the decay rate of 108Cd is excluded. We have confirmed the double-β transition Q values of 106Cd and 110Pd recently measured with the Penning-trap mass spectrometers SHIPTRAP and ISOLTRAP, respectively. Furthermore, the atomic masses of the involved nuclides (106,108,110Cd, 106,108,110Pd) have been directly linked to the atomic mass standard.

  9. Can the reinforcing value of food be measured in bulimia nervosa?

    PubMed Central

    Schebendach, Janet; Broft, Allegra; Foltin, Richard W.; Walsh, B. Timothy

    2013-01-01

    Binge eating is a core clinical feature of bulimia nervosa (BN). Enhanced reinforcing value of food may play a role in this behavioral disturbance, but a systematic behavioral assessment of objective measures of the rewarding value of binge eating is lacking. The purpose of this study was to quantify the reinforcing value of food in BN patients as compared with normal controls. A progressive ratio (PR) computerized work task was completed under binge and non-binge instruction. The task consisted of 12 trials. The first trial required 50 keyboard taps to earn one portion of yogurt shake, and subsequent trials required progressive work increments of 200 taps for each additional portion. Completion of all 12 trials required 13,800 taps to earn 2,100 ml of shake. The breakpoint, defined as the largest ratio completed before a participant stopped working, was the measure of reinforcing efficacy. Ten patients and 10 controls completed the experiment. Under binge instruction, patients completed more trials and taps, and had a higher breakpoint than controls. The non-binge instruction yielded opposite findings; compared to controls, patients completed fewer trials and taps, and had a lower breakpoint. These results support the feasibility and potential utility of a PR task to quantify the reinforcing value of food in patients with BN. PMID:23178173

  10. Measurement of wilderness benefits and option value, with an application to the Washakie Wilderness, northwest Wyoming

    SciTech Connect

    Barrick, K.A.

    1983-01-01

    The Federal government is currently considering up to 135 oil and gas leases in the Washakie Wilderness which provides a realistic uncertainty about the future supply of wilderness characteristics. The measurement technique is a contingent valuation questionnaire, which was mailed to 1199 individuals (581 responses). The research samples include: Washakie Wilderness visitors, Yellowstone National Park visitors, the residents of four US cities (Salt Lake City, Portland, Nashville, and Orlando) and rural residents located near the selected cities. The results indicate that the average wilderness consumer surplus is $80.13 for Washakie Wilderness visitors, $39.00 for Yellowstone visitors, $8.97 for the urban group and $7.80 for the rural group. The relative importance of four attributes of wilderness option value are measured, including value in, a personal visit to the Washakie (12-25% of value), others being able to visit (16-26%), the wilderness being available for future generations (30-40%), and the existence of wilderness regardless of anyone visiting it (25%). On- and off-site users attribute statistically different weights to the first three attributes, but not to existence value.

  11. Minimal sufficient positive-operator valued measure on a separable Hilbert space

    SciTech Connect

    Kuramochi, Yui

    2015-10-15

    We introduce a concept of a minimal sufficient positive-operator valued measure (POVM), which is the least redundant POVM among the POVMs that have the equivalent information about the measured quantum system. Assuming the system Hilbert space to be separable, we show that for a given POVM, a sufficient statistic called a Lehmann-Scheffé-Bahadur statistic induces a minimal sufficient POVM. We also show that every POVM has an equivalent minimal sufficient POVM and that such a minimal sufficient POVM is unique up to relabeling neglecting null sets. We apply these results to discrete POVMs and information conservation conditions proposed by the author.

  12. Accuracy, Precision, Sensitivity, and Specificity of Noninvasive ICP Absolute Value Measurements.

    PubMed

    Krakauskaite, Solventa; Petkus, Vytautas; Bartusis, Laimonas; Zakelis, Rolandas; Chomskis, Romanas; Preiksaitis, Aidanas; Ragauskas, Arminas; Matijosaitis, Vaidas; Petrikonis, Kestutis; Rastenyte, Daiva

    2016-01-01

    An innovative absolute intracranial pressure (ICP) value measurement method has been validated by multicenter comparative clinical studies. The method is based on two-depth transcranial Doppler (TCD) technology and uses intracranial and extracranial segments of the ophthalmic artery as pressure sensors. The ophthalmic artery is used as a natural pair of "scales" that compares ICP with controlled pressure Pe, which is externally applied to the orbit. To balance the scales, ICP = Pe a special two-depth TCD device was used as a pressure balance indicator. The proposed method is the only noninvasive ICP measurement method that does not need patient-specific calibration. PMID:27165929

  13. Measurements of Sc I gf-values. [absorption spectroscopy using heat pipe oven

    NASA Technical Reports Server (NTRS)

    Parkinson, W. H.; Reeves, E. M.; Tomkins, F. S.

    1976-01-01

    Absolute gf-values were obtained for 98 transitions in neutral scandium by the hook method using an inductively coupled heat-pipe oven. Of the 98 lines, 51 are classified, 33 are unclassified lines that occur in pairs with the lower energy level identified, and 14 are unclassified but are believed to originate from one of the two lower levels of the ground state. The results are compared with semiempirical and other measurement results in the literature.

  14. CBF measured by Xe-CT: Approach to analysis and normal values

    SciTech Connect

    Yonas, H.; Darby, J.M.; Marks, E.C.; Durham, S.R.; Maxwell, C. )

    1991-09-01

    Normal reference values and a practical approach to CBF analysis are needed for routine clinical analysis and interpretation of xenon-enhanced computed tomography (CT) CBF studies. The authors measured CBF in 67 normal individuals with the GE 9800 CT scanner adapted for CBF imaging with stable Xe. CBF values for vascular territories were systematically analyzed using the clustering of contiguous 2-cm circular regions of interest (ROIs) placed within the cortical mantle and basal ganglia. Mixed cortical flows averaged 51 {plus minus} 10ml.100g-1.min-1. High and low flow compartments, sampled by placing 5-mm circular ROIs in regions containing the highest and lowest flow values in each hemisphere, averaged 84 {plus minus} 14 and 20 {plus minus} 5 ml.100 g-1.min-1, respectively. Mixed cortical flow values as well as values within the high flow compartment demonstrated significant decline with age; however, there were no significant age-related changes in the low flow compartment. The clustering of systematically placed cortical and subcortical ROIs has provided a normative data base for Xe-CT CBF and a flexible and uncomplicated method for the analysis of CBF maps generated by Xe-enhanced CT.

  15. Using Effort to Measure Reward Value of Faces in Children with Autism

    PubMed Central

    Ewing, Louise; Pellicano, Elizabeth; Rhodes, Gillian

    2013-01-01

    According to one influential account, face processing atypicalities in autism reflect reduced reward value of faces, which results in limited attention to faces during development and a consequent failure to acquire face expertise. Surprisingly, however, there is a paucity of work directly investigating the reward value of faces for individuals with autism and the evidence for diminished face rewards in this population remains equivocal. In the current study, we measured how hard children with autism would work to view faces, using an effortful key-press sequence, and whether they were sensitive to the differential reward value of attractive and unattractive faces. Contrary to expectations, cognitively able children with autism did not differ from typically developing children of similar age and ability in their willingness to work to view faces. Moreover, the effort expended was strongly positively correlated with facial attractiveness ratings in both groups of children. There was also no evidence of atypical reward values for other, less social categories (cars and inverted faces) in the children with autism. These results speak against the possibility that face recognition difficulties in autism are explained by atypical reward value of faces. PMID:24236140

  16. Using effort to measure reward value of faces in children with autism.

    PubMed

    Ewing, Louise; Pellicano, Elizabeth; Rhodes, Gillian

    2013-01-01

    According to one influential account, face processing atypicalities in autism reflect reduced reward value of faces, which results in limited attention to faces during development and a consequent failure to acquire face expertise. Surprisingly, however, there is a paucity of work directly investigating the reward value of faces for individuals with autism and the evidence for diminished face rewards in this population remains equivocal. In the current study, we measured how hard children with autism would work to view faces, using an effortful key-press sequence, and whether they were sensitive to the differential reward value of attractive and unattractive faces. Contrary to expectations, cognitively able children with autism did not differ from typically developing children of similar age and ability in their willingness to work to view faces. Moreover, the effort expended was strongly positively correlated with facial attractiveness ratings in both groups of children. There was also no evidence of atypical reward values for other, less social categories (cars and inverted faces) in the children with autism. These results speak against the possibility that face recognition difficulties in autism are explained by atypical reward value of faces. PMID:24236140

  17. "Smart" Electromechanical Shock Absorber

    NASA Technical Reports Server (NTRS)

    Stokes, Lebarian; Glenn, Dean C.; Carroll, Monty B.

    1989-01-01

    Shock-absorbing apparatus includes electromechanical actuator and digital feedback control circuitry rather than springs and hydraulic damping as in conventional shock absorbers. Device not subject to leakage and requires little or no maintenance. Attenuator parameters adjusted in response to sensory feedback and predictive algorithms to obtain desired damping characteristic. Device programmed to decelerate slowly approaching vehicle or other large object according to prescribed damping characteristic.

  18. Iron Chalcogenide Photovoltaic Absorbers

    SciTech Connect

    Yu, Liping; Lany, Stephan; Kykyneshi, Robert; Jieratum, Vorranutch; Ravichandran, Ram; Pelatt, Brian; Altschul, Emmeline; Platt, Heather A. S.; Wager, John F.; Keszler, Douglas A.; Zunger, Alex

    2011-08-10

    An integrated computational and experimental study of FeS₂ pyrite reveals that phase coexistence is an important factor limiting performance as a thin-film solar absorber. This phase coexistence is suppressed with the ternary materials Fe₂SiS₄ and Fe₂GeS₄, which also exhibit higher band gaps than FeS₂. Thus, the ternaries provide a new entry point for development of thin-film absorbers and high-efficiency photovoltaics.

  19. The calibration of plane parallel ionisation chambers for the measurement of absorbed dose in electron beams of low to medium energies. Part 1: the NACP chamber.

    PubMed

    Cross, P; Freeman, N

    1996-09-01

    A study was made of calibrating the NACP plane parallel chamber in electron beams from linear accelerators of a different manufacture with energies, Ep,o' from 4.4 to 19.1 MeV, and also in 4 and 6 MV photon beams as well as a cobalt60 beam. The photon beam measurements were both IN-AIR and IN-PHANTOM. With the exception of the lowest energy electron beam (nominal 5 MeV), the ND values from measurements in the electron beams were within +/- 1% of the average value from the three different methods according to the AAPM TG 39 protocol. The preferred method of calibration of an electron chamber is of course in an electron beam at R100 in water. This can still be done in medium energy electron beams (nominal 7 to 14 MeV) for the NACP chamber with the same degree of accuracy and precision as with AAPM TG 39 methodology. Alternatively the traditional cobalt-60 calibration beam can be replaced by a low energy (4-6MV) photon beam for in-phantom calibrations at 50 mm depth, giving comparable results, and with no more uncertainties than those obtained in electron beams. PMID:8936730

  20. Freshwater DOM quantity and quality from a two-component model of UV absorbance

    USGS Publications Warehouse

    Carter, Heather T.; Tipping, Edward; Koprivnjak, Jean-Francois; Miller, Matthew P.; Cookson, Brenda; Hamilton-Taylor, John

    2012-01-01

    We present a model that considers UV-absorbing dissolved organic matter (DOM) to consist of two components (A and B), each with a distinct and constant spectrum. Component A absorbs UV light strongly, and is therefore presumed to possess aromatic chromophores and hydrophobic character, whereas B absorbs weakly and can be assumed hydrophilic. We parameterised the model with dissolved organic carbon concentrations [DOC] and corresponding UV spectra for c. 1700 filtered surface water samples from North America and the United Kingdom, by optimising extinction coefficients for A and B, together with a small constant concentration of non-absorbing DOM (0.80 mg DOC L-1). Good unbiased predictions of [DOC] from absorbance data at 270 and 350 nm were obtained (r2 = 0.98), the sum of squared residuals in [DOC] being reduced by 66% compared to a regression model fitted to absorbance at 270 nm alone. The parameterised model can use measured optical absorbance values at any pair of suitable wavelengths to calculate both [DOC] and the relative amounts of A and B in a water sample, i.e. measures of quantity and quality. Blind prediction of [DOC] was satisfactory for 9 of 11 independent data sets (181 of 213 individual samples).

  1. Leaf absorbance and photosynthesis

    NASA Technical Reports Server (NTRS)

    Schurer, Kees

    1994-01-01

    The absorption spectrum of a leaf is often thought to contain some clues to the photosynthetic action spectrum of chlorophyll. Of course, absorption of photons is needed for photosynthesis, but the reverse, photosynthesis when there is absorption, is not necessarily true. As a check on the existence of absorption limits we measured spectra for a few different leaves. Two techniques for measuring absorption have been used, viz. the separate determination of the diffuse reflectance and the diffuse transmittance with the leaf at a port of an integrating sphere and the direct determination of the non-absorbed fraction with the leaf in the sphere. In a cross-check both methods yielded the same results for the absorption spectrum. The spectrum of a Fuchsia leaf, covering the short-wave region from 350 to 2500 nm, shows a high absorption in UV, blue and red, the well known dip in the green and a steep fall-off at 700 nm. Absorption drops to virtually zero in the near infrared, with subsequent absorptions, corresponding to the water absorption bands. In more detailed spectra, taken at 5 nm intervals with a 5 nm bandwidth, differences in chlorophyll content show in the different depths of the dip around 550 nm and in a small shift of the absorption edge at 700 nm. Spectra for Geranium (Pelargonium zonale) and Hibiscus (with a higher chlorophyll content) show that the upper limit for photosynthesis can not be much above 700 nm. No evidence, however, is to be seen of a lower limit for photosynthesis and, in fact, some experiments down to 300 nm still did not show a decrease of the absorption although it is well recognized that no photosynthesis results with 300 nm wavelengths.

  2. [Value of serum PSA and PAP measurement with newly developed latex turbidimetric immunoassay].

    PubMed

    Akino, H; Tsuka, H; Okada, K; Tsuchiya, Y; Matsubara, M; Arimura, K

    1995-06-01

    Serum prostate specific antigen (PSA) and prostatic acid-phosphatase (PAP) levels in normal controls, and patients with prostate cancer, benign prostate hypertrophy (BPH) and other urological diseases were examined with a newly developed latex turbidimetric immunoassay (LPIA ACE PSA, LPIA ACE PAP, IATRON LABORATORIES, INC., Tokyo, Japan). The advantageous characteristics of this method are small amount (10 microliters) of serum required and short time (about 20 min.) for performing this assay. There was a high linear correlation between LPIA ACE PSA and MARKIT-F PA (r2 = 0.953), between LPIA ACE PSA and TANDEM-E PSA (r2 = 0.881) and between LPIA ACE PAP and ABBOTT-PAP EIA (r2 = 0.946). When the BPH patients (n = 110) were used as negative controls, the cut-off value of PSA was determined to be 4.3 ng/ml. Using this level as the cut-off value, the sensitivity was 78% (42 positive/54 untreated prostate cancer patients), specificity (negative rate in BPH patients) was 95% and efficiency was 89%. In a follow-up study of prostate cancer, the PSA value was elevated above the cut-off value in 68% at the time of clinical progression. These findings suggest that LPIA ACE PSA is a useful tool for serum PSA measurement. The cut-off value of PAP measured with LPIA ACE PAP was 9.0 ng/ml, which was determined by the same method as PSA. The sensitivity, specificity and efficiency ware 39%, 96% and 77%, respectively. These findings indicate that PAP is less useful than PSA in the diagnosis of prostate cancer.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7544063

  3. The weak measurement process and the weak value of spin for metastable helium 23S1

    NASA Astrophysics Data System (ADS)

    Monachello, Vincenzo; Barker, Peter; Flack, Robert; Hiley, Basil

    2016-05-01

    An experiment is being designed and constructed in order to measure the weak value of spin for an atomic system. The principle of the ``weak measurement'' process was first proposed by Aharonov, Albert and Vaidman, and describes a scenario in which a system is weakly coupled to a pointer between well-defined pre- and post-selected states. This experiment will utilise a pulsed supersonic beam of spin-1 metastable Helium (He*) atoms in the 23S1 state. The spin of the pre-selected He* atoms will be weakly coupled to its centre-of-mass. During its flight, the atomic beam will be prepared in a desired quantum state and travel through two inhomogeneous magnets (weak and strong) which both comprise the ``weak measurement'' process. The deviation of the post-selected ms = + 1 state as measured using a micro-channel plate, phosphor screen and CCD camera setup will allow for the determination of the weak value of spin. This poster will report on the methods used and the experimental realisation.

  4. Structured Metal Film as Perfect Absorber

    NASA Astrophysics Data System (ADS)

    Xiong, Xiang; Jiang, Shang-Chi; Peng, Ru-Wen; Wang, Mu

    2014-03-01

    With standing U-shaped resonators, fish-spear-like resonator has been designed for the first time as the building block to assemble perfect absorbers. The samples have been fabricated with two-photon polymerization process and FTIR measurement results support the effectiveness of the perfect absorber design. In such a structure the polarization-dependent resonance occurs between the tines of the spears instead of the conventional design where the resonance occurs between the metallic layers separated by a dielectric interlayer. The incident light neither transmits nor reflects back which results in unit absorbance. The power of light is trapped between the tines of spears and finally be absorbed. The whole structure is covered with a continuous metallic layer with good thermo-conductance, which provides an excellent approach to deal with heat dissipation, is enlightening in exploring metamaterial absorbers.

  5. Mild solutions to a measure-valued mass evolution problem with flux boundary conditions

    NASA Astrophysics Data System (ADS)

    Evers, Joep H. M.; Hille, Sander C.; Muntean, Adrian

    2015-08-01

    We investigate the well-posedness and approximation of mild solutions to a class of linear transport equations on the unit interval [ 0, 1 ] endowed with a linear discontinuous production term, formulated in the space M ([ 0, 1 ]) of finite Borel measures. Our working technique includes a detailed boundary layer analysis in terms of a semigroup representation of solutions in spaces of measures able to cope with the passage to the singular limit where thickness of the layer vanishes. We obtain not only a suitable concept of solutions to the chosen measure-valued evolution problem, but also derive convergence rates for the approximation procedure and get insight in the structure of flux boundary conditions for the limit problem.

  6. Improved Correction of IR Loss in Diffuse Shortwave Measurements: An ARM Value-Added Product

    SciTech Connect

    Younkin, K; Long, CN

    2003-11-01

    Simple single black detector pyranometers, such as the Eppley Precision Spectral Pyranometer (PSP) used by the Atmospheric Radiation Measurement (ARM) Program, are known to lose energy via infrared (IR) emission to the sky. This is especially a problem when making clear-sky diffuse shortwave (SW) measurements, which are inherently of low magnitude and suffer the greatest IR loss. Dutton et al. (2001) proposed a technique using information from collocated pyrgeometers to help compensate for this IR loss. The technique uses an empirically derived relationship between the pyrgeometer detector data (and alternatively the detector data plus the difference between the pyrgeometer case and dome temperatures) and the nighttime pyranometer IR loss data. This relationship is then used to apply a correction to the diffuse SW data during daylight hours. We developed an ARM value-added product (VAP) called the SW DIFF CORR 1DUTT VAP to apply the Dutton et al. correction technique to ARM PSP diffuse SW measurements.

  7. Non-invasive blood pressure measurement: values, problems and applicability in the common marmoset (Callithrix jacchus).

    PubMed

    Mietsch, M; Einspanier, A

    2015-07-01

    The common marmoset (Callithrix jacchus, C. j.) is an established primate model in biomedical research and for human-related diseases. Monitoring of cardiovascular parameters including blood pressure (BP) is important for the health surveillance of these experimental animals and the quantification of diseases or pharmaceutical substances influencing BP. Measurement guidelines for C. j. do not exist yet; therefore, the present study was carried out to establish a practicable protocol based on recommendations of the American College of Veterinary Internal Medicine (ACVIM). Furthermore, BP data of 49 marmosets (13.8-202.4 months of age) were obtained via high-definition oscillometry to further knowledge of physiological parameters and gender-related differences in this primate. The thighs proved to be the most suitable measurement localization, since systolic values were less variable (left 4.03 ± 2.90%, right 5.96 ± 2.77%) compared with the tail (12.7 ± 6.96%). BP values were similar in the morning and in the afternoon (P > 0.05). Data were highly reproducible within and between several sessions on three consecutive days (P > 0.05) as well as over the course of 20 months (P > 0.05). Furthermore, the measurement time for females was significantly shorter than for males (5:14 ± 1:59 min versus 6:50 ± 1:58 min, P = 0.007). Measurement recommendations for the common marmoset were successfully established. Standardized values enabled a reliable comparison of BP parameters, e.g. for cardiovascular, toxicological or metabolic research. PMID:25552521

  8. Inferring runoff generation processes through high resolution spatial and temporal UV-Vis absorbance measurements in a mountainous headwater catchment in Southern Ecuador

    NASA Astrophysics Data System (ADS)

    Windhorst, David; Schob, Sarah; Zang, Carina; Crespo, Patricio; Breuer, Lutz

    2015-04-01

    The alpine grassland páramo - typically occurring in the headwater catchments of the Andes - plays an important role in flow regulation, hydropower generation and local water supply. However, hydrological and hydro-biogeochemical processes in the páramo and their potential reactions to climate and land use change are largely unknown. Therefore, we used a UV-Vis absorbance spectrometer to investigate fluxes of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity and nitrate (NO3-N) in a small headwater catchment (91.31 km²) in the páramo in south Ecuador on a 5 min temporal and 100 m spatial resolution to gain first insights in its hydrological functioning. Spatial sampling was realized during three snapshot sampling campaigns along the 14.2 km long stream between October 2013 and January 2014, while temporal sampling took place at a permanent sampling site within the catchment between February and June 2014. To identify the runoff generation processes the spatial patterns have been associated with local site specific (e.g. fish ponds) and sub-catchment wide (e.g. land use) characteristics. Storm flow events within the time series allowed to further study temporal changes and rotational patterns of concentration-discharge relations (hysteresis). In total, 35 events were identified to be suitable for analyzing hysteresis effects of BOD, COD, and turbidity. Nitrate concentrations could be studied for 20 events. Regardless of the flow conditions nitrate leaching increased with a growing share of non-native pine forests or pastures in the study area. During low flow conditions, the high water holding capacity of the upstream páramo areas ensured a continuous supply of BOD to the stream. Pasture and pine forest sites, mostly occurring in the downstream section of the stream, contributed to BOD only during discharge events. Contradicting the expectations the trout farms along the lower part of the streams had a relatively closed nutrient cycle and

  9. Smart absorbing property of composites with MWCNTs and carbonyl iron as the filler

    NASA Astrophysics Data System (ADS)

    Xu, Yonggang; Yuan, Liming; Cai, Jun; Zhang, Deyuan

    2013-10-01

    A smart absorbing composite was prepared by mixing silicone rubber, multi-walled carbon nanotubes (MWCNTs) and flaky carbonyl iron particles (CIPs) in a two-roll mixer. The complex permittivity and permeability of composites with variable compression strain was measured by the transmission method and dc electric conductivity was measured by the standard four-point contact method, then the reflection loss (RL) could be calculated to evaluate the microwave absorbing ability. The results showed that the applied compression strain made the complex permittivity decrease but not obviously due to the broken original conductive network. The enforcement of the strain on the complex permeability was attributed to the orientation of flaky CIPs. With the compressing strain applied on the composites with thickness 1 mm or 1.5 mm, the RL value decreased (minimum -13.2 dB and -25.1 dB) and the absorbing band (RL<-10 dB) was widened (5.2-10.6 GHz and 4.0-8.4 GHz). While as the composite thickness decreased caused by the compression strain, the RL value still decreased (minimum -12.4 dB and -18.6 dB) and the absorbing band was also broadened (6.5-10.7 GHz and 4.4-10.0 GHz). Thus the smart absorbing property was effective on preparing absorbers with wide absorption band and high absorption ratio.

  10. Reconceptualizing 'effectiveness' in environmental projects: can we measure values-related achievements?

    PubMed

    Harder, Marie K; Velasco, Ismael; Burford, Gemma; Podger, Dimity; Janoušková, Svatava; Piggot, Georgia; Hoover, Elona

    2014-06-15

    There have been recent calls for a shift to an evidence-based paradigm in environmental management, grounded in systematic monitoring and evaluation, but achieving this will be complex and difficult. Evaluating the educational components of environmental initiatives presents particular challenges, because these programs often have multiple concurrent goals and may value 'human outcomes', such as value change, which are intangible and difficult to quantify. This paper describes a fresh approach based on co-creating an entirely new values-based assessment framework with expert practitioners worldwide. We first discuss the development of a generic framework of 'Proto-Indicators' (reference criteria constituting prototypes for measurable indicators), and then demonstrate its application within a reforestation project in Mexico where indicators and assessment tools were localized to enhance context-relevance. Rigorously derived using unitary validity, with an emphasis on relevance, practicability and logical consistency from user perspectives, this framework represents a step-wise advance in the evaluation of non-formal EE/ESD programs. This article also highlights three important principles with broader implications for evaluation, valuation and assessment processes within environmental management: namely peer-elicitation, localizability, and an explicit focus on ethical values. We discuss these principles in relation to the development of sustainability indicators at local and global levels, especially in relation to post-2015 Sustainable Development Goals. PMID:24681651

  11. Direct measurement of large-scale quantum states via expectation values of non-Hermitian matrices

    PubMed Central

    Bolduc, Eliot; Gariepy, Genevieve; Leach, Jonathan

    2016-01-01

    In quantum mechanics, predictions are made by way of calculating expectation values of observables, which take the form of Hermitian operators. Non-Hermitian operators, however, are not necessarily devoid of physical significance, and they can play a crucial role in the characterization of quantum states. Here we show that the expectation values of a particular set of non-Hermitian matrices, which we call column operators, directly yield the complex coefficients of a quantum state vector. We provide a definition of the state vector in terms of measurable quantities by decomposing these column operators into observables. The technique we propose renders very-large-scale quantum states significantly more accessible in the laboratory, as we demonstrate by experimentally characterizing a 100,000-dimensional entangled state. This represents an improvement of two orders of magnitude with respect to previous phase-and-amplitude characterizations of discrete entangled states. PMID:26780858

  12. Direct measurement of large-scale quantum states via expectation values of non-Hermitian matrices.

    PubMed

    Bolduc, Eliot; Gariepy, Genevieve; Leach, Jonathan

    2016-01-01

    In quantum mechanics, predictions are made by way of calculating expectation values of observables, which take the form of Hermitian operators. Non-Hermitian operators, however, are not necessarily devoid of physical significance, and they can play a crucial role in the characterization of quantum states. Here we show that the expectation values of a particular set of non-Hermitian matrices, which we call column operators, directly yield the complex coefficients of a quantum state vector. We provide a definition of the state vector in terms of measurable quantities by decomposing these column operators into observables. The technique we propose renders very-large-scale quantum states significantly more accessible in the laboratory, as we demonstrate by experimentally characterizing a 100,000-dimensional entangled state. This represents an improvement of two orders of magnitude with respect to previous phase-and-amplitude characterizations of discrete entangled states. PMID:26780858

  13. Direct measurement of large-scale quantum states via expectation values of non-Hermitian matrices

    NASA Astrophysics Data System (ADS)

    Bolduc, Eliot; Gariepy, Genevieve; Leach, Jonathan

    2016-01-01

    In quantum mechanics, predictions are made by way of calculating expectation values of observables, which take the form of Hermitian operators. Non-Hermitian operators, however, are not necessarily devoid of physical significance, and they can play a crucial role in the characterization of quantum states. Here we show that the expectation values of a particular set of non-Hermitian matrices, which we call column operators, directly yield the complex coefficients of a quantum state vector. We provide a definition of the state vector in terms of measurable quantities by decomposing these column operators into observables. The technique we propose renders very-large-scale quantum states significantly more accessible in the laboratory, as we demonstrate by experimentally characterizing a 100,000-dimensional entangled state. This represents an improvement of two orders of magnitude with respect to previous phase-and-amplitude characterizations of discrete entangled states.

  14. Identification of Inhibitor Concentrations to Efficiently Screen and Measure Inhibition Ki Values against Solute Carrier Transporters

    PubMed Central

    Zheng, Xiaowan; Polli, James

    2010-01-01

    The objective was to identify inhibitor concentrations to efficiently screen and measure inhibition Ki values of solute carrier (SLC) transporters. The intestinal bile acid transporter and its native substrate taurocholate were used as a model system. Inhibition experiments were conducted using 27 compounds. For each compound, the inhibition constant Ki was obtained from the comprehensive inhibition profile, and referred as the reference Ki. Ki values were also estimated from various partial profiles and were compared to the reference Ki. A screening Ki was estimated from one data point and also compared to the reference Ki. Results indicate that Ki can be accurately measured using an inhibitor concentration range of only 0-Ki via five different inhibitor concentrations. Additionally, a screening concentration of 10-fold the substrate affinity Kt for potent inhibitors (Ki < 20Kt) and 100-fold Kt for nonpotent inhibitors (Ki > 20Kt) provided an accurate Ki estimation. Results were validated through inhibition studies of two other SLC transporters. In conclusion, experimental conditions to screen and measure accurate transporter inhibition constant Ki are suggested where a low range of inhibitor concentrations can be used. This approach is advantageous in that minimal compound is needed to perform studies and accommodates compounds with low aqueous solubility. PMID:20553862

  15. Student-Valued Measurable Teaching Behaviors of Award-Winning Pharmacy Preceptors

    PubMed Central

    Lau, Carmen; Patel, Mitul; Mac, Chi; Krueger, Janelle; Danielson, Jennifer; Weber, Stanley S.

    2015-01-01

    Objective. To identify specific preceptor teaching-coaching, role modeling, and facilitating behaviors valued by pharmacy students and to develop measures of those behaviors that can be used for an experiential education quality assurance program. Methods. Using a qualitative research approach, we conducted a thematic analysis of student comments about excellent preceptors to identify behaviors exhibited by those preceptors. Identified behaviors were sorted according to the preceptor’s role as role model, teacher/coach, or learning facilitator; measurable descriptors for each behavior were then developed. Results. Data analysis resulted in identification of 15 measurable behavior themes, the most frequent being: having an interest in student learning and success, making time for students, and displaying a positive preceptor attitude. Measureable descriptors were developed for 5 role-modeling behaviors, 6 teaching-coaching behaviors, and 4 facilitating behaviors. Conclusion. Preceptors may need to be evaluated in their separate roles as teacher-coach, role model, and learning facilitator. The developed measures in this report could be used in site quality evaluation. PMID:26889063

  16. Measure-valued solutions for a hierarchically size-structured population

    NASA Astrophysics Data System (ADS)

    Ackleh, Azmy S.; Ito, Kazufumi

    We present a hierarchically size-structured population model with growth, mortality and reproduction rates which depend on a function of the population density ( environment). We present an example to show that if the growth rate is not always a decreasing function of the environment (e.g., a growth which exhibits the Allee effect) the emergence of a singular solution which contains a Dirac delta mass component is possible, even if the vital rates of the individual and the initial data are smooth functions. Therefore, we study the existence of measure-valued solutions. Our approach is based on the vanishing viscosity method.

  17. Unidirectional perfect absorber.

    PubMed

    Jin, L; Wang, P; Song, Z

    2016-01-01

    This study proposes a unidirectional perfect absorber (UPA), which we realized with a two-arm Aharonov-Bohm interferometer, that consists of a dissipative resonator side-coupled to a uniform resonator array. The UPA has reflection-less full absorption on one direction, and reflectionless full transmission on the other, with an appropriate magnetic flux and coupling, detuning, and loss of the side-coupled resonator. The magnetic flux controls the transmission, the left transmission is larger for magnetic flux less than one-half flux quantum; and the right transmission is larger for magnetic flux between one-half and one flux quantum. Besides, a perfect absorber (PA) can be realized based on the UPA, in which light waves from both sides, with arbitrary superposition of the ampli- tude and phase, are perfectly absorbed. The UPA is expected to be useful in the design of novel optical devices. PMID:27615125

  18. Analog of Formula of Total Probability for Quantum Observables Represented by Positive Operator Valued Measures

    NASA Astrophysics Data System (ADS)

    Khrennikov, Andrei

    2016-09-01

    We represent Born's rule as an analog of the formula of total probability (FTP): the classical formula is perturbed by an additive interference term. In this note we consider practically the most general case: generalized quantum observables given by positive operator valued measures and measurement feedback on states described by atomic instruments. This representation of Born's rule clarifies the probabilistic structure of quantum mechanics (QM). The probabilistic counterpart of QM can be treated as the probability update machinery based on the special generalization of classical FTP. This is the essence of the Växjö interpretation of QM: statistical realist contextual and local interpretation. We analyze the origin of the additional interference term in quantum FTP by considering the contextual structure of the two slit experiment which was emphasized by R. Feynman.

  19. Time-energy trade-off in unambiguous-state-discrimination positive operator-valued measures

    NASA Astrophysics Data System (ADS)

    Uzdin, Raam; Gat, Omri

    2013-11-01

    Unambiguous-nonorthogonal-state discrimination has a fundamental importance in quantum information. Moreover, it can be used for entanglement distillation and secure communication. The discrimination is carried out by a positive operator-valued measure (POVM) generalized measurement, which is typically implemented by coupling the system to an ancilla. We find a trade-off between the needed energy resources and the evolution time needed to implement the POVM and express it in terms of an actionlike cost inequality. We find the realization that minimizes this actionlike cost and show that, in this case, the cost is determined by the maximal population transfer from the system to the ancilla. We demonstrate our findings in an example of a three-level system coupled to a laser.

  20. A comparison of airborne wake vortex detection measurements with values predicted from potential theory

    NASA Technical Reports Server (NTRS)

    Stewart, Eric C.

    1991-01-01

    An analysis of flight measurements made near a wake vortex was conducted to explore the feasibility of providing a pilot with useful wake avoidance information. The measurements were made with relatively low cost flow and motion sensors on a light airplane flying near the wake vortex of a turboprop airplane weighing approximately 90000 lbs. Algorithms were developed which removed the response of the airplane to control inputs from the total airplane response and produced parameters which were due solely to the flow field of the vortex. These parameters were compared with values predicted by potential theory. The results indicated that the presence of the vortex could be detected by a combination of parameters derived from the simple sensors. However, the location and strength of the vortex cannot be determined without additional and more accurate sensors.

  1. Singular value description of a digital radiographic detector: Theory and measurements

    PubMed Central

    Kyprianou, Iacovos S.; Badano, Aldo; Gallas, Brandon D.; Myers, Kyle J.

    2008-01-01

    The H operator represents the deterministic performance of any imaging system. For a linear, digital imaging system, this system operator can be written in terms of a matrix, H, that describes the deterministic response of the system to a set of point objects. A singular value decomposition of this matrix results in a set of orthogonal functions (singular vectors) that form the system basis. A linear combination of these vectors completely describes the transfer of objects through the linear system, where the respective singular values associated with each singular vector describe the magnitude with which that contribution to the object is transferred through the system. This paper is focused on the measurement, analysis, and interpretation of the H matrix for digital x-ray detectors. A key ingredient in the measurement of the H matrix is the detector response to a single x ray (or infinitestimal x-ray beam). The authors have developed a method to estimate the 2D detector shift-variant, asymmetric ray response function (RRF) from multiple measured line response functions (LRFs) using a modified edge technique. The RRF measurements cover a range of x-ray incident angles from 0° (equivalent location at the detector center) to 30° (equivalent location at the detector edge) for a standard radiographic or cone-beam CT geometric setup. To demonstrate the method, three beam qualities were tested using the inherent, Lu∕Er, and Yb beam filtration. The authors show that measures using the LRF, derived from an edge measurement, underestimate the system’s performance when compared with the H matrix derived using the RRF. Furthermore, the authors show that edge measurements must be performed at multiple directions in order to capture rotational asymmetries of the RRF. The authors interpret the results of the H matrix SVD and provide correlations with the familiar MTF methodology. Discussion is made about the benefits of the H matrix technique with regards to signal

  2. Singular value description of a digital radiographic detector: Theory and measurements

    SciTech Connect

    Kyprianou, Iacovos S.; Badano, Aldo; Gallas, Brandon D.; Myers, Kyle J.

    2008-10-15

    The H operator represents the deterministic performance of any imaging system. For a linear, digital imaging system, this system operator can be written in terms of a matrix, H, that describes the deterministic response of the system to a set of point objects. A singular value decomposition of this matrix results in a set of orthogonal functions (singular vectors) that form the system basis. A linear combination of these vectors completely describes the transfer of objects through the linear system, where the respective singular values associated with each singular vector describe the magnitude with which that contribution to the object is transferred through the system. This paper is focused on the measurement, analysis, and interpretation of the H matrix for digital x-ray detectors. A key ingredient in the measurement of the H matrix is the detector response to a single x ray (or infinitestimal x-ray beam). The authors have developed a method to estimate the 2D detector shift-variant, asymmetric ray response function (RRF) from multiple measured line response functions (LRFs) using a modified edge technique. The RRF measurements cover a range of x-ray incident angles from 0 deg. (equivalent location at the detector center) to 30 deg. (equivalent location at the detector edge) for a standard radiographic or cone-beam CT geometric setup. To demonstrate the method, three beam qualities were tested using the inherent, Lu/Er, and Yb beam filtration. The authors show that measures using the LRF, derived from an edge measurement, underestimate the system's performance when compared with the H matrix derived using the RRF. Furthermore, the authors show that edge measurements must be performed at multiple directions in order to capture rotational asymmetries of the RRF. The authors interpret the results of the H matrix SVD and provide correlations with the familiar MTF methodology. Discussion is made about the benefits of the H matrix technique with regards to signal

  3. Electromagnetic Wave Absorbing Properties of Amorphous Carbon Nanotubes

    PubMed Central

    Zhao, Tingkai; Hou, Cuilin; Zhang, Hongyan; Zhu, Ruoxing; She, Shengfei; Wang, Jungao; Li, Tiehu; Liu, Zhifu; Wei, Bingqing

    2014-01-01

    Amorphous carbon nanotubes (ACNTs) with diameters in the range of 7–50 nm were used as absorber materials for electromagnetic waves. The electromagnetic wave absorbing composite films were prepared by a dip-coating method using a uniform mixture of rare earth lanthanum nitrate doped ACNTs and polyvinyl chloride (PVC). The microstructures of ACNTs and ACNT/PVC composites were characterized using transmission electron microscope and X-ray diffraction, and their electromagnetic wave absorbing properties were measured using a vector-network analyzer. The experimental results indicated that the electromagnetic wave absorbing properties of ACNTs are superior to multi-walled CNTs, and greatly improved by doping 6 wt% lanthanum nitrate. The reflection loss (R) value of a lanthanum nitrate doped ACNT/PVC composite was −25.02 dB at 14.44 GHz, and the frequency bandwidth corresponding to the reflector loss at −10 dB was up to 5.8 GHz within the frequency range of 2–18 GHz. PMID:25007783

  4. Realising the Real Benefits of Outsourcing: Measurement Excellence and Its Importance in Achieving Long Term Value

    NASA Astrophysics Data System (ADS)

    Oshri, Ilan; Kotlarsky, Julia

    These days firms are, more than ever, pressed to demonstrate returns on their investment in outsourcing. While the initial returns can always be associated with one-off cost cutting, outsourcing arrangements are complex, often involving inter-related high-value activities, which makes the realisation of long-term benefits from outsourcing ever more challenging. Executives in client firms are no longer satisfied with the same level of service delivery through the outsourcing lifecycle. They seek to achieve business transformation and innovation in their present and future services, beyond satisfying service level agreements (SLAs). Clearly the business world is facing a new challenge: an outsourcing delivery system of high-value activities that demonstrates value over time and across business functions. However, despite such expectations, many client firms are in the dark when trying to measure and quantify the return on outsourcing investments: results of this research show that less than half of all CIOs and CFOs (43%) have attempted to calculate the financial impact of outsourcing to their bottom line, indicating that the financial benefits are difficult to quantify (51%).

  5. Measurement of the solar heat gain coefficient and U value of windows with insect screens

    SciTech Connect

    Brunger, A.; Dubrous, F.M.; Harrison, S.

    1999-07-01

    Energy ratings are currently being used in a number of countries to assist in the selection of windows and doors based on energy performance. Developed for simple comparison purposes, these rating numbers do not take into account window removable attachments such as insect screens that are, nevertheless, widely used. Research was carried out to assess the effect of insect screens on the heat gains and losses of windows. The work reported in this paper deals with the effect of one screen type on the performance of a base-case, double-glazed window. Using an indoor solar simulator facility, measurements of the window solar heat gain coefficient (SHGC) and U value were made for different screen attachment configurations and climatic conditions. Results with the sample window tested indicate that insect screens placed on the outdoor side can reduce its SHGC by 46% with only a 7% reduction in its U value (0.19 W/m{sup 2}{center_dot}C), and that insect screens placed on the indoor side can reduce its SHGC by 15% while reducing its U value by 14% (0.38 W/m{sup 2}{center_dot}C).

  6. Singular value decomposition filtering for enhanced signal extraction from two-dimensional beam emission spectroscopy measurements

    SciTech Connect

    Shafer, M. W.; McKee, G. R.; Schlossberg, D. J.

    2008-10-15

    The signal-to-noise ratio (SNR) of extracted turbulence features from beam emission spectroscopy (BES) data is significantly enhanced via application of singular value decomposition (SVD) methods. BES measures two-dimensional localized density fluctuations in DIII-D. The SNR of core turbulence characteristics is typically limited by noise arising from electronic noise, photon noise, and fluctuations in the observed neutral beam. SVD filtering has led to a significant enhancement in the SNR, reducing errors in time-resolved measurements of core turbulence characteristics, including correlation lengths, decorrelation rates, and group velocities. The SVD filtration technique is applied to BES data by combining multiple physically adjacent sampling locations to extract spatially correlated signals while partially removing unwanted incoherent noise. Using approximately half of the singular value weighted modes to reconstruct turbulence signals is found to improve SNR by up to a factor of 4, while maintaining the spatial structure of the turbulence. Unique aspects of application of SVD to broadband turbulence data are discussed.

  7. Metrological traceability of the measured values of properties of engineering materials

    NASA Astrophysics Data System (ADS)

    Roebben, G.; Linsinger, T.; Lamberty, A.; Emons, H.

    2010-04-01

    Global comparability of the measured values of material properties is based on some fundamental metrological concepts. These concepts are either already widely implemented in current procedures for materials testing or they are being further developed and increasingly accepted and used. An important aspect of the comparability of measurement results is metrological traceability. This paper aims at illustrating with practical examples how to apply the concept of metrological traceability as defined in ISO/IEC Guide 99:2007, known also as the VIM (International Vocabulary of Metrology), in the field of engineering material properties. VIM distinguishes three different types of references for traceability: either to a system of units, such as the SI, to a measurement procedure or to a physical measurement standard. For each approach, an example is given in the field of engineering material properties, including appropriate traceability statements and means to achieve the traceability. The role of certified reference materials is highlighted, as well as practical consequences of traceability requirements for the design of reference material certification projects.

  8. Optimizing the value of measuring inferior vena cava diameter in shocked patients.

    PubMed

    Abu-Zidan, Fikri M

    2016-02-01

    Point-of-care ultrasound has been increasingly used in evaluating shocked patients including the measurement of inferior vena cava (IVC) diameter. Operators should standardize their technique in scanning IVC. Relative changes are more important than absolute numbers. We advise using the longitudinal view (B mode) to evaluate the gross collapsibility, and the M mode to measure the IVC diameter. Combining the collapsibility and diameter size will increase the value of IVC measurement. This approach has been very useful in the resuscitation of shocked patients, monitoring their fluid demands, and predicting recurrence of shock. Pitfalls in measuring IVC diameter include increased intra-thoracic pressure by mechanical ventilation or increased right atrial pressure by pulmonary embolism or heart failure. The IVC diameter is not useful in cases of increased intra-abdominal pressure (abdominal compartment syndrome) or direct pressure on the IVC. The IVC diameter should be combined with focused echocardiography and correlated with the clinical picture as a whole to be useful. PMID:26855888

  9. Comparison Between Measured and Calculated Free Calcium Values at Different Serum Albumin Concentrations

    PubMed Central

    Mir, Altaf Ahmad; Goyal, Bela; Datta, Sudip Kumar; Ikkurthi, Saidaiah; Pal, Arnab

    2016-01-01

    Introduction: Free ionic calcium is the metabolically active component of total calcium (TCa) in blood. However, most laboratories report TCa levels that are dependent on serum albumin concentration. Hence, several formulae have evolved to calculate free calcium levels from TCa after adjustment for albumin. However, free calcium can directly be measured using direction selective electrodes rather than spectrophotometric methods used in autoanalyzers. Objectives: This study compares the levels of free calcium obtained by measurement by direct ion selective electrode (ISE) and the one calculated as a function of TCa by formulae. Materials and Methods: A total of 254 serum samples submitted to clinical biochemistry laboratory of a tertiary care hospital were analyzed for total protein, albumin, and TCa by standard spectrophotometric methods and for free calcium by direct ISE. Three commonly used formulae viz. Orrell, Berry et al. and Payne et al. were used to calculate adjusted TCa. Calculated free calcium was obtained by taking 50% of these values. Results: A significant difference (P < 0.05) was observed between calculated free calcium by all the three formulae and measured free calcium estimated by direct ISE using paired t-test and Bland–Altman plots. Conclusion: Formulae for predicting free calcium by estimating TCa and albumin lacks consistency in prediction and free calcium should be evaluated by direct measurement. PMID:27365914

  10. Construction of extremal local positive-operator-valued measures under symmetry

    SciTech Connect

    Virmani, S.; Plenio, M.B.

    2003-06-01

    We study the local implementation of positive-operator-valued measures (POVMs) when we require only the faithful reproduction of the statistics of the measurement outcomes for all initial states. We first demonstrate that any POVM with separable elements can be implemented by a separable superoperator, and develop techniques for calculating the extreme points of POVMs under a certain class of constraint that includes separability and positive partial transposition. As examples we consider measurements that are invariant under various symmetry groups (Werner, isotropic, Bell diagonal, local orthogonal), and demonstrate that in these cases separability of the POVM elements is equivalent to implementability via local operations and classical communication (LOCC). We also calculate the extrema of these classes of measurement under the groups that we consider, and give explicit LOCC protocols for attaining them. These protocols are hence optimal methods for locally discriminating between states of these symmetries. One of many interesting consequences is that the best way to locally discriminate Bell-diagonal mixed states is to perform a two-outcome POVM using local von Neumann projections. This is true regardless of the cost function, the number of states being discriminated, or the prior probabilities. Our results give the first cases of local mixed-state discrimination that can be analyzed quantitatively in full, and may have application to other problems such as demonstrations of nonlocality, experimental entanglement witnesses, and perhaps even entanglement distillation.

  11. Traceable measurement and uncertainty analysis of the gross calorific value of methane determined by isoperibolic calorimetry

    NASA Astrophysics Data System (ADS)

    Haloua, F.; Foulon, E.; Allard, A.; Hay, B.; Filtz, J. R.

    2015-12-01

    As methane is the major component of natural gas and non-conventional gases as biogas or mine gases, its energy content has to be measured accurately regardless of its production site for fiscal trading of transported and distributed natural gas. The determination of calorific value of fuel gases with the lowest uncertainty can only be performed by direct method with a reference gas calorimeter. To address this point, LNE developed a few years ago an isoperibolic reference gas calorimeter according to the Rossini’s principle. The energy content Hs of methane of purity 99.9995% has been measured to 55 507.996 kJ kg-1 (890.485 kJ mol-1) with an expanded relative uncertainty of 0.091% (coverage factor k  =  2.101 providing a level of confidence of approximately 95%). These results are based on ten repeated measurements and on the uncertainty assessment performed in accordance with the guide to the expression of uncertainty in measurement (GUM). The experimental setup and the results are reported here and for the first time, the fully detailed uncertainty calculation is exposed.

  12. The Measurement of Subjective Value and Its Relation to Contingent Valuation and Environmental Public Goods

    PubMed Central

    Khaw, Mel W.; Grab, Denise A.; Livermore, Michael A.; Vossler, Christian A.; Glimcher, Paul W.

    2015-01-01

    Environmental public goods—including national parks, clean air/water, and ecosystem services—provide substantial benefits on a global scale. These goods have unique characteristics in that they are typically “nonmarket” goods, with values from both use and passive use that accrue to a large number of individuals both in current and future generations. In this study, we test the hypothesis that neural signals in areas correlated with subjective valuations for essentially all other previously studied categories of goods (ventromedial prefrontal cortex and ventral striatum) also correlate with environmental valuations. We use contingent valuation (CV) as our behavioral tool for measuring valuations of environmental public goods. CV is a standard stated preference approach that presents survey respondents with information on an issue and asks questions that help policymakers determine how much citizens are willing to pay for a public good or policy. We scanned human subjects while they viewed environmental proposals, along with three other classes of goods. The presentation of all four classes of goods yielded robust and similar patterns of temporally synchronized brain activation within attentional networks. The activations associated with the traditional classes of goods replicate previous correlations between neural activity in valuation areas and behavioral preferences. In contrast, CV-elicited values for environmental proposals did not correlate with brain activity at either the individual or population level. For a sub-population of participants, CV-elicited values were correlated with activity within the dorsomedial prefrontal cortex, a region associated with cognitive control and shifting decision strategies. The results show that neural activity associated with the subjective valuation of environmental proposals differs profoundly from the neural activity associated with previously examined goods and preference measures. PMID:26221734

  13. Octanol/water partition coefficients of phthalate esters: A comparison of measured, estimated, and computed values

    SciTech Connect

    Ellington, J.; Floyd, T.

    1995-12-31

    Reliable octanol/water partition coefficients (K{sub ow}) of nine dialkyl phthalate esters are needed in an ongoing benthic organisms toxicity testing program. The equilibrium distribution of an organic chemical between water and octanol (K{sub ow}) is a physical constant that can be used to calculate both bioaccumulation factors (BAFs) and equilibrium constants for sediment-organic carbon partitioning (K{sub oc}). The log K{sub ow}s reported in the literature for a single chemical often span several orders of magnitude. For example, the reported log K{sub ow}s of bis(2-ethylehxyl) phthalate range from a low of 5.11 to a high of 9.61. The log K{sub ow}s of the dialkyl phthalate esters in this study were expected to range from < 2 (dimethyl) to > 8 (didecyl). The slow-stir method as described by de Bruijn has been shown to avoid emulsion formation and allow measure of K{sub ow}s of chemicals with log K{sub ow} > 6. In addition to measurement by the slow-stir method the K{sub ow}s were also determined by a high performance liquid chromatography (HPLC) estimation method and calculated by a computer based program that was designed to calculate physical/chemical properties (SPARC). The greatest difference between the slow-stir and SPARC K{sub ow} values was 0.19 with the other differences less than 0.1 log units. All the HPLC estimated values were at least 0.7 log units lower than the slow-stir value. For example, the log K{sub ow}s determined for dibutly phthalate by the slow-stir, SPARC, and HPLC methods were 4.50 {+-} 0.03, 4.61, and 4.00, respectively.

  14. The Measurement of Subjective Value and Its Relation to Contingent Valuation and Environmental Public Goods.

    PubMed

    Khaw, Mel W; Grab, Denise A; Livermore, Michael A; Vossler, Christian A; Glimcher, Paul W

    2015-01-01

    Environmental public goods--including national parks, clean air/water, and ecosystem services--provide substantial benefits on a global scale. These goods have unique characteristics in that they are typically "nonmarket" goods, with values from both use and passive use that accrue to a large number of individuals both in current and future generations. In this study, we test the hypothesis that neural signals in areas correlated with subjective valuations for essentially all other previously studied categories of goods (ventromedial prefrontal cortex and ventral striatum) also correlate with environmental valuations. We use contingent valuation (CV) as our behavioral tool for measuring valuations of environmental public goods. CV is a standard stated preference approach that presents survey respondents with information on an issue and asks questions that help policymakers determine how much citizens are willing to pay for a public good or policy. We scanned human subjects while they viewed environmental proposals, along with three other classes of goods. The presentation of all four classes of goods yielded robust and similar patterns of temporally synchronized brain activation within attentional networks. The activations associated with the traditional classes of goods replicate previous correlations between neural activity in valuation areas and behavioral preferences. In contrast, CV-elicited values for environmental proposals did not correlate with brain activity at either the individual or population level. For a sub-population of participants, CV-elicited values were correlated with activity within the dorsomedial prefrontal cortex, a region associated with cognitive control and shifting decision strategies. The results show that neural activity associated with the subjective valuation of environmental proposals differs profoundly from the neural activity associated with previously examined goods and preference measures. PMID:26221734

  15. Detection of myocardial viability by dobutamine stress echocardiography: incremental value of diastolic wall thickness measurement

    PubMed Central

    Zaglavara, T; Pillay, T; Karvounis, H; Haaverstad, R; Parharidis, G; Louridas, G; Kenny, A

    2005-01-01

    Objective: To assess the diagnostic accuracy of baseline diastolic wall thickness (DWT) alone and as an adjunct to dobutamine stress echocardiography (DSE) for prediction of myocardial viability in patients with ischaemic left ventricular (LV) dysfunction, with the recovery of resting function after revascularisation as the yardstick. Patients: 24 patients with ischaemic LV dysfunction (ejection fraction < 40%) scheduled for surgical revascularisation. Setting: Regional cardiothoracic centre. Methods: All patients underwent DSE before and resting echocardiography six months after revascularisation. DWT was measured in each of the 16 LV segments. A receiver operating characteristic (ROC) and a multi-ROC curve were generated to assess the ability of DWT alone and in combination with DSE to predict myocardial viability. Results: DWT > 0.6 cm provided a sensitivity of 80%, a specificity of 51%, and a negative predictive value of 80% for the prediction of viability in akinetic segments. DSE had an excellent specificity (92%) but a modest sensitivity (60%) in akinetic segments. A combination of improvement at DSE or DWT > 0.8 cm improved sensitivity (90% v 60%, p < 0.001) and negative predictive value (92% v 78%, p  =  0.03) in akinetic segments compared with DSE alone. This was achieved with some loss in specificity (75% v 92%, p  =  0.01) and positive predictive value (71% v 82%, p  =  0.79). Conclusions: DWT measurement may improve the sensitivity of DSE for the detection of myocardial viability. Akinetic segments with DWT > 0.8 cm have a good chance of recovery despite the absence of contractile reserve during DSE. Further testing may be required before excluding myocardial viability in these cases. PMID:15831644

  16. Multiple-layer Radiation Absorber

    NASA Astrophysics Data System (ADS)

    Baker, Robert M. L.; Baker, Bonnie Sue

    A structure is discussed for absorbing incident radiation, either electromagnetic (EM) or sound. Such a surface structure is needed, for example, in a highly sensitive high-frequency gravitational wave or HFGW detector such as the Li-Baker. The multi-layer absorber, which is discussed, is constructed with metamaterial [MM] layer or layers on top. This MM is configured for a specific EM or sound radiation frequency band, which absorbs incident EM or sound radiation without reflection. Below these top MM layers is a substrate of conventional EM-radiation absorbing or acoustical absorbing reflective material, such as an array of pyramidal foam absorbers. Incident radiation is partially absorbed by the MM layer or layers, and then it is more absorbed by the lower absorbing and reflecting substrate. The remaining reflected radiation is even further absorbed by the MM layers on its "way out_ so that essentially all of the incident radiation is absorbed _ a nearly perfect black-body absorber. In a HFGW detector a substrate, such as foam absorbers, may outgas into a high vacuum and reduce the capability of the vacuum-producing equipment, however, the layers above this lowest substrate will seal the absorbing and reflecting substrate from any external vacuum. The layers also serve to seal the absorbing material against air or water flow past the surfaces of aircraft, watercraft or submarines. Other applications for such a multiple-level radiation absorber include stealth aircraft, missiles and submarines.

  17. Light Absorbing Organic Carbon from Wood Pyrolysis: Closure Study between Measured and Modeled Optical Properties at Controlled Relative Humidity between 40 and 95%

    NASA Astrophysics Data System (ADS)

    Mena, F. C.; Brem, B. T.; Chen, Y.; Bond, T. C.; Rood, M. J.

    2012-12-01

    Hygroscopic aerosols uptake water at increased ambient relative humidity (RH), and this changes their size, shape, and composition. This affects their optical properties, and thus their radiative forcing. Organic carbon (OC) is an important component of the aerosol system due to its ubiquity and because its hygroscopic and light absorption properties are not well understood. In this work we have modeled the hygroscopic growth and optical properties (extinction, scattering, absorption, and single scattering albedo) at three wavelengths of OC from wood pyrolysis at increasing RH from 40 to 95%. Our goal was to reproduce laboratory measurements of the optical properties, particularly absorption of OC. Measurements included hygroscopicity with an H-TDMA, extinction with an extinction cell, and scattering with a nephelometer. Absorption was calculated by difference of extinction and scattering. The κ-Köhler model was used to model the hygroscopic growth, and different refractive index mixing rules were used to model the mixing state of OC+water mixtures. The hygroscopic growth factor (κ) for OC was 0.08 ± 0.02 (corresponding to a growth factor (GF) = 1.19 ± 0.03 at 90% RH). The linear volume average mixing rule, Lorentz-Lorenz, Maxwell-Garnett, Bruggeman, and Core-Shell configuration were not able to reproduce the laboratory results. The mixing rule that was able to reproduce the structure of the absorption dependence on RH was the Dynamic Effective Medium Approximation (DEMA). Using refractive indices of m = 1.57 + 0.017i at 467 nm, 1.57 + 0.01i at 530 nm, and 1.57 + 0.002i nm at 660 nm, which were adjusted to obtain absorption measurements at dry conditions, we obtained closure at 467 nm and 530 nm wavelengths at RH from 40 to 95%, within the uncertainties of the model and the measurements. Absorption at 660 nm was very low, and it was not possible to confirm closure due to detection limitations of the measurements. Our results indicate that absorption by OC is

  18. Methods for evaluating the reference value in laboratory intercomparisons of dimensional measurements

    NASA Astrophysics Data System (ADS)

    Stone, Jack A.

    2005-08-01

    A number of methods have been proposed to evaluate the reference value for intercomparisons of laboratory measurements. Methods for establishing the reference value include the arithmetic mean, weighted mean (with weights proportional to the reciprocals of the squared uncertainties), median, and total median. In addition, it has been suggested that it might be possible to modify the weighted mean, using iterative approaches to automatically eliminate outliers or to modify the weights in light of the results of the intercomparison. No single one of the analysis methods is best for all circumstances, nor can the efficiency of any method be determined without making assumptions about the underlying nature of the intercomparison. (How well do the participants evaluate their uncertainties? What is the underlying distribution of errors, including outliers? Are the errors correlated between one laboratory and the next?) Although there is considerable divergence of opinion as to what constitutes realistic assumptions, completed international comparisons can begin to provide at least rough guidance for constructing models. In this paper, I will try to construct models that are consistent with what we have learned thus far from CCL (Consultative Committee for Length) key comparisons in the field of dimensional metrology. Based on such models, I have explored various methods for establishing a reference value, to determine which methods are likely to produce a reference value with a low uncertainty. As would be expected, there is no single method that is always superior; results depend on both the underlying assumptions and on the spread and distribution of claimed uncertainties of the participating laboratories.

  19. Performance-based measures of physical function as mortality predictors: Incremental value beyond self-reports

    PubMed Central

    Goldman, Noreen; Glei, Dana A.; Rosero-Bixby, Luis; Chiou, Shu-Ti; Weinstein, Maxine

    2015-01-01

    BACKGROUND Although previous studies have indicated that performance assessments strongly predict future survival, few have evaluated the incremental value in the presence of controls for self-reported activity and mobility limitations. OBJECTIVE We assess and compare the added value of four tests – walking speed, chair stands, grip strength, and peak expiratory flow (PEF) – for predicting all-cause mortality. METHODS Using population-based samples of older adults in Costa Rica (n = 2290, aged 60+) and Taiwan (n = 1219, aged 53+), we estimate proportional hazards models of mortality for an approximate five-year period. Receiver Operator Characteristic (ROC) curves are used to assess the prognostic value of each performance assessment. RESULTS Self-reported measures of physical limitations contribute substantial gains in mortality prediction, whereas performance-based assessments yield modest incremental gains. PEF provides the greatest added value, followed by grip strength. Our results suggest that including more than two performance assessments may provide little improvement in mortality prediction. CONCLUSIONS PEF and grip strength are often simpler to administer in home interview settings, impose less of a burden on some respondents, and, in the presence of self-reported limitations, appear to be better predictors of mortality than do walking speed or chair stands. COMMENTS Being unable to perform the test is often a strong predictor of mortality, but these indicators are not well-defined. Exclusion rates vary by the specific task and are likely to depend on the underlying demographic, health, social and cultural characteristics of the sample. PMID:25866473

  20. Estimation of utility values from visual analog scale measures of health in patients undergoing cardiac surgery

    PubMed Central

    Oddershede, Lars; Andreasen, Jan Jesper; Ehlers, Lars

    2014-01-01

    Introduction In health economic evaluations, mapping can be used to estimate utility values from other health outcomes in order to calculate quality adjusted life-years. Currently, no methods exist to map visual analog scale (VAS) scores to utility values. This study aimed to develop and propose a statistical algorithm for mapping five dimensions of health, measured on VASs, to utility scores in patients suffering from cardiovascular disease. Methods Patients undergoing coronary artery bypass grafting at Aalborg University Hospital in Denmark were asked to score their health using the five VAS items (mobility, self-care, ability to perform usual activities, pain, and presence of anxiety or depression) and the EuroQol 5 Dimensions questionnaire. Regression analysis was used to estimate four mapping models from patients’ age, sex, and the self-reported VAS scores. Prediction errors were compared between mapping models and on subsets of the observed utility scores. Agreement between predicted and observed values was assessed using Bland–Altman plots. Results Random effects generalized least squares (GLS) regression yielded the best results when quadratic terms of VAS scores were included. Mapping models fitted using the Tobit model and censored least absolute deviation regression did not appear superior to GLS regression. The mapping models were able to explain approximately 63%–65% of the variation in the observed utility scores. The mean absolute error of predictions increased as the observed utility values decreased. Conclusion We concluded that it was possible to predict utility scores from VAS scores of the five dimensions of health used in the EuroQol questionnaires. However, the use of the mapping model may be inappropriate in more severe conditions. PMID:24453497

  1. Attenuation of external Bremsstrahlung in metallic absorbers

    SciTech Connect

    Dhaliwal, A.S.; Powar, M.S.; Singh, M. )

    1990-12-01

    In this paper attenuation of bremsstrahlung from {sup 147}Pm and {sup 170}Tm beta emitters has been studied in aluminum, copper, tin, and lead metallic absorbers. Bremsstrahlung spectra and mass attenuation coefficients for monoenergetic gamma rays are used to calculate theoretical attenuation curves. Magnetic deflection and beta stopping techniques are used to measure the integral bremsstrahlung intensities above 30 keV in different target thicknesses. Comparison of measured and calculated attenuation curves shows a good agreement for various absorbers, thus providing a test of this technique, which may be useful in understanding bremsstrahlung intensity buildup and in the design of optimum shielding for bremsstrahlung sources. It is found that the absorption of bremsstrahlung in metallic absorbers does not obey an exponential law and that absorbers act as energy filters.

  2. Neutron Absorbing Alloys

    DOEpatents

    Mizia, Ronald E.; Shaber, Eric L.; DuPont, John N.; Robino, Charles V.; Williams, David B.

    2004-05-04

    The present invention is drawn to new classes of advanced neutron absorbing structural materials for use in spent nuclear fuel applications requiring structural strength, weldability, and long term corrosion resistance. Particularly, an austenitic stainless steel alloy containing gadolinium and less than 5% of a ferrite content is disclosed. Additionally, a nickel-based alloy containing gadolinium and greater than 50% nickel is also disclosed.

  3. Comparison of the calculated absorbed dose using the Cadplan™ treatment planning software and Tld-100 measurements in an Alderson-Rando phantom for a bronchogenic treatment

    SciTech Connect

    Gutiérrez Castillo, J. G.; Álvarez Romero, J. T. E-mail: fisarmandotorres@gmail.com Calderón, A. Torres E-mail: fisarmandotorres@gmail.com M, V. Tovar E-mail: fisarmandotorres@gmail.com

    2014-11-07

    To verify the accuracy of the absorbed doses D calculated by a TPS Cadplan for a bronchogenic treatment (in an Alderson-Rando phantom) are chosen ten points with the following D's and localizations. Point 1, posterior position on the left edge with 136.4 Gy. Points: 2, 3 and 4 in the left lung with 104.9, 104.3 and 105.8 Gy, respectively; points 5 and 6 at the mediastinum with 192.4 and 173.5 Gy; points 7, 8 and 9 in the right lung with 105.8, 104.2 and 104.7 Gy, and 10 at posterior position on right edge with 143.7 Gy. IAEA type capsules with TLD 100 powder are placed, planned and irradiated. The evaluation of the absorbed dose is carried out a curve of calibration for the LiF response (nC) {sup vs} {sup DW}, to several cavity theories. The traceability for the DW is obtained with a secondary standard calibrated at the NRC (Canada). The dosimetric properties for the materials considered are determined from the Hounsfield numbers reported by the TPS. The stopping power ratios are calculated for nominal spectrum to 6 MV photons. The percent variations among the planned and determined D in all the cases they are < ± 3%.

  4. Comparison of the calculated absorbed dose using the Cadplan™ treatment planning software and Tld-100 measurements in an Alderson-Rando phantom for a bronchogenic treatment

    NASA Astrophysics Data System (ADS)

    Gutiérrez Castillo, J. G.; Álvarez Romero, J. T.; Torres Calderón, A.; Tovar, M. V.

    2014-11-01

    To verify the accuracy of the absorbed doses D calculated by a TPS Cadplan for a bronchogenic treatment (in an Alderson-Rando phantom) are chosen ten points with the following D's and localizations. Point 1, posterior position on the left edge with 136.4 Gy. Points: 2, 3 and 4 in the left lung with 104.9, 104.3 and 105.8 Gy, respectively; points 5 and 6 at the mediastinum with 192.4 and 173.5 Gy; points 7, 8 and 9 in the right lung with 105.8, 104.2 and 104.7 Gy, and 10 at posterior position on right edge with 143.7 Gy. IAEA type capsules with TLD 100 powder are placed, planned and irradiated. The evaluation of the absorbed dose is carried out a curve of calibration for the LiF response (nC) vs DW, to several cavity theories. The traceability for the DW is obtained with a secondary standard calibrated at the NRC (Canada). The dosimetric properties for the materials considered are determined from the Hounsfield numbers reported by the TPS. The stopping power ratios are calculated for nominal spectrum to 6 MV photons. The percent variations among the planned and determined D in all the cases they are < ± 3%.

  5. A Novel Scoring System to Measure Radiographic Abnormalities and Related Spirometric Values in Cured Pulmonary Tuberculosis

    PubMed Central

    Báez-Saldaña, Renata; López-Arteaga, Yesenia; Bizarrón-Muro, Alma; Ferreira-Guerrero, Elizabeth; Ferreyra-Reyes, Leticia; Delgado-Sánchez, Guadalupe; Cruz-Hervert, Luis Pablo; Mongua-Rodríguez, Norma; García-García, Lourdes

    2013-01-01

    Background Despite chemotherapy, patients with cured pulmonary tuberculosis may result in lung functional impairment. Objective To evaluate a novel scoring system based on the degree of radiographic abnormalities and related spirometric values in patients with cured pulmonary tuberculosis. Methods One hundred and twenty seven patients with cured pulmonary tuberculosis were prospectively enrolled in a referral hospital specializing in respiratory diseases. Spirometry was performed and the extent of radiographic abnormalities was evaluated twice by each of two readers to generate a novel quantitative score. Scoring reproducibility was analyzed by the intra-class correlation coefficient (ICC) and the Bland-Altman method. Multiple linear regression models were performed to assess the association of the extent of radiographic abnormalities with spirometric values. Results The intra-observer agreement for scoring of radiographic abnormalities (SRA) showed an ICC of 0.81 (CI:95%, 0.67–0.95) and 0.78 (CI:95%, 0.65–0.92), for reader 1 and 2, respectively. Inter-observer reproducibility for the first measurement was 0.83 (CI:95%, 0.71–0.95), and for the second measurement was 0.74 (CI:95%, 0.58–0.90). The Bland-Altman analysis of the intra-observer agreement showed a mean bias of 0.87% and -0.55% and an inter-observer agreement of -0.35% and -1.78%, indicating a minor average systematic variability. After adjustment for age, gender, height, smoking status, pack-years of smoking, and degree of dyspnea, the scoring degree of radiographic abnormalities was significantly and negatively associated with absolute and percent predicted values of FVC: -0.07 (CI:95%, -0.01 to -0.04); -2.48 (CI:95%, -3.45 to -1.50); and FEV1 -0.07 (CI:95%, -0.10 to -0.05); -2.92 (CI:95%, -3.87 to -1.97) respectively, in the patients studied. Conclusion The extent of radiographic abnormalities, as evaluated through our novel scoring system, was inversely associated with spirometric values, and

  6. Comparison between three methods to value lower tear meniscus measured by image software

    NASA Astrophysics Data System (ADS)

    García-Resúa, Carlos; Pena-Verdeal, Hugo; Lira, Madalena; Oliveira, M. Elisabete Real; Giráldez, María. Jesús; Yebra-Pimentel, Eva

    2013-11-01

    To measure different parameters of lower tear meniscus height (TMH) by using photography with open software of measurement. TMH was addressed from lower eyelid to the top of the meniscus (absolute TMH) and to the brightest meniscus reflex (reflex TMH). 121 young healthy subjects were included in the study. The lower tear meniscus was videotaped by a digital camera attached to a slit lamp. Three videos were recorded in central meniscus portion on three different methods: slit lamp without fluorescein instillation, slit lamp with fluorescein instillation and TearscopeTM without fluorescein instillation. Then, a masked observed obtained an image from each video and measured TMH by using open source software of measurement based on Java (NIH ImageJ). Absolute central (TMH-CA), absolute with fluorescein (TMH-F) and absolute using the Tearscope (TMH-Tc) were compared each other as well as reflex central (TMH-CR) and reflex Tearscope (TMH-TcR). Mean +/- S.D. values of TMH-CA, TMH-CR, TMH-F, TMH-Tc and TMH-TcR of 0.209 +/- 0.049, 0.139 +/- 0.031, 0.222 +/- 0.058, 0.175 +/- 0.045 and 0.109 +/- 0.029 mm, respectively were found. Paired t-test was performed for the relationship between TMH-CA - TMH-CR, TMH-CA - TMH-F, TMH-CA - TMH-Tc, TMH-F - TMH-Tc, TMH-Tc - TMH-TcR and TMH-CR - TMH-TcR. In all cases, it was found a significant difference between both variables (all p < 0.008). This study showed a useful tool to objectively measure TMH by photography. Eye care professionals should maintain the same TMH parameter in the follow-up visits, due to the difference between them.

  7. How Do Value-Added Indicators Compare to Other Measures of Teacher Effectiveness? What We Know Series: Value-Added Methods and Applications. Knowledge Brief 5

    ERIC Educational Resources Information Center

    Harris, Douglas N.

    2012-01-01

    In the recent drive to revamp teacher evaluation and accountability, measures of a teacher's value added have played the starring role. But the star of the show is not always the best actor, nor can the star succeed without a strong supporting cast. In assessing teacher performance, observations of classroom practice, portfolios of teachers' work,…

  8. Effect of sampling location on L* values and pH measurements and their relationship in broiler breast fillets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lightness (CIELAB L*) and pH values are the most widely measured quality indicators for broiler breast fillets (pectoralis major). Measurement of L* values with a spectrophotometer can be done through Specular Component Included (SCI) or Specular Component Excluded (SCE) modes. The intra-fillet loca...

  9. Is Log Ratio a Good Value for Measuring Return in Stock Investments?

    NASA Astrophysics Data System (ADS)

    Ultsch, Alfred

    Measuring the rate of return is an important issue for theory and practice of investments in the stock market. A common measure for rate of return is the logarithm of the ratio of successive prices (LogRatio). In this paper it is shown that LogRatio as well as arithmetic return rate (Ratio) have several disadvantages. As an alternative relative differences (RelDiff) are proposed to measure return. The stability against numerical and rounding errors of RelDiff is much better than for LogRatios and Ratio). RelDiff values are identical to LogRatios and Return for small absolutes. The usage of RelDiff maps returns to a finite range. For most subsequent analyses this is a big advantage. The usefulness of the approach is demonstrated on daily return rates of a large set of actual stocks. It is shown that returns can be modeled with a very simple mixture of distributions in great precision using Relative differences.

  10. Radar Absorbing Materials for Cube Stealth Satellite

    NASA Astrophysics Data System (ADS)

    Micheli, D.; Pastore, R.; Vricella, A.; Marchetti, M.

    A Cube Stealth Satellite is proposed for potential applications in defense system. Particularly, the faces of the satellite exposed to the Earth are made of nanostructured materials able to absorb radar surveillance electromagnetic waves, conferring stealth capability to the cube satellite. Microwave absorbing and shielding material tiles are proposed using composite materials consisting in epoxy-resin and carbon nanotubes filler. The electric permittivity of the composite nanostructured materials is measured and discussed. Such data are used by the modeling algorithm to design the microwave absorbing and the shielding faces of the cube satellite. The electromagnetic modeling takes into account for several incidence angles (0-80°), extended frequency band (2-18 GHz), and for the minimization of the electromagnetic reflection coefficient. The evolutionary algorithm used for microwave layered microwave absorber modeling is the recently developed Winning Particle Optimization. The mathematical model of the absorbing structure is finally experimentally validated by comparing the electromagnetic simulation to the measurement of the manufactured radar absorber tile. Nanostructured composite materials manufacturing process and electromagnetic reflection measurements methods are described. Finally, a finite element method analysis of the electromagnetic scattering by cube stealth satellite is performed.

  11. thin films as absorber

    NASA Astrophysics Data System (ADS)

    González, J. O.; Shaji, S.; Avellaneda, D.; Castillo, G. A.; Das Roy, T. K.; Krishnan, B.

    2014-09-01

    Photovoltaic structures were prepared using AgSb(S x Se1- x )2 as absorber and CdS as window layer at various conditions via a hybrid technique of chemical bath deposition and thermal evaporation followed by heat treatments. Silver antimony sulfo selenide thin films [AgSb(S x Se1- x )2] were prepared by heating multilayers of sequentially deposited Sb2S3/Ag dipped in Na2SeSO3 solution, glass/Sb2S3/Ag/Se. For this, Sb2S3 thin films were deposited from a chemical bath containing SbCl3 and Na2S2O3. Then, Ag thin films were thermally evaporated on glass/Sb2S3, followed by selenization by dipping in an acidic solution of Na2SeSO3. The duration of dipping was varied as 3, 4 and 5 h. Two different heat treatments, one at 350 °C for 20 min in vacuum followed by a post-heat treatment at 325 °C for 2 h in Ar, and the other at 350 °C for 1 h in Ar, were applied to the multilayers of different configurations. X-ray diffraction results showed the formation of AgSb(S x Se1- x )2 thin films as the primary phase and AgSb(S,Se)2 and Sb2S3 as secondary phases. Morphology and elemental detection were done by scanning electron microscopy and energy dispersive X-ray analysis. X-ray photoelectron spectroscopic studies showed the depthwise composition of the films. Optical properties were determined by UV-vis-IR transmittance and reflection spectral analysis. AgSb(S x Se1- x )2 formed at different conditions was incorporated in PV structures glass/FTO/CdS/AgSb(S x Se1- x )2/C/Ag. Chemically deposited post-annealed CdS thin films of various thicknesses were used as window layer. J- V characteristics of the cells were measured under dark and AM1.5 illumination. Analysis of the J- V characteristics resulted in the best solar cell parameters of V oc = 520 mV, J sc = 9.70 mA cm-2, FF = 0.50 and η = 2.7 %.

  12. A hydraulic absorber for wideband vibration reduction in ship hulls

    SciTech Connect

    Hsueh, W.J.; Lee, Y.J. . Dept. of Naval Architecture and Ocean Engineering)

    1994-02-01

    A vibration reduction of ship hulls by an active absorber system is proposed. In the scheme, a tuned mass is moved according to the hull vibration as measured by a multi-mode sensing system in order to generate a suitable active force for vibration reduction of hull girder. In order to supply the large amount of required power, a hydraulic servo system is implemented. Then the dynamic characteristic of the hydraulic system is considered for system design. Based on stochastic theory and optimal theory, the control law of the system is derived in order to approach the optimal level of vibration reduction. A 10-t absorber is applied to a 87,000-t oil tanker to demonstrate the feasibility of this scheme. The results show that the multi-peak values of resonance are suppressed in frequency response. Moreover, the vibration excited by propeller and engine is reduced to an extremely efficient level by this scheme.

  13. Measuring and predicting Delta(vap)H298 values of ionic liquids.

    PubMed

    Deyko, Alexey; Lovelock, Kevin R J; Corfield, Jo-Anne; Taylor, Alasdair W; Gooden, Peter N; Villar-Garcia, Ignacio J; Licence, Peter; Jones, Robert G; Krasovskiy, Vladimir G; Chernikova, Elena A; Kustov, Leonid M

    2009-10-14

    We report the enthalpies of vaporisation (measured using temperature programmed desorption by mass spectrometry) of twelve ionic liquids (ILs), covering four imidazolium, [C(m)C(n)Im]+, five pyrrolidinium, [C(n)C(m)Pyrr]+, two pyridinium, [C(n)Py]+, and a dication, [C3(C1Im)2]2+ based IL. These cations were paired with a range of anions: [BF4]-, [FeCl4]-, [N(CN)2]-, [PF3(C2F5)3]- ([FAP]-), [(CF3SO2)2N]- ([Tf2N]-) and [SCN]-. Using these results, plus those for a further eight imidazolium based ILs published earlier (which include the anions [CF3SO3]- ([TfO]-), [PF6]- and [EtSO4]-), we show that the enthalpies of vaporisation can be decomposed into three components. The first component is the Coulombic interaction between the ions, DeltaU(Cou,R), which is a function of the IL molar volume, V(m), and a parameter R(r) which quantifies the relative change in anion-cation distance on evaporation from the liquid phase to the ion pair in the gas phase. The second and third components are the van der Waals contributions from the anion, DeltaH(vdw,A), and the cation, DeltaH(vdw,C). We derive a universal value for R(r), and individual values of DeltaH(vdw,A) and DeltaH(vdw,C) for each of the anions and cations considered in this study. Given the molar volume, it is possible to estimate the enthalpies of vaporisation of ILs composed of any combination of the ions considered here; values for fourteen ILs which have not yet been studied experimentally are given. PMID:19774286

  14. Validation of an online questionnaire measure of the relative reinforcing value of food.

    PubMed

    Reslan, Summar; Saules, Karen K; Greenwald, Mark K

    2012-08-01

    Laboratory methods and questionnaires to assess the relative reinforcing value of food (RRV-F) have been developed, but this is the first study to validate an online questionnaire measure of the RRV-F. Participants (281 college students) completed an online survey assessing demographic variables, food preferences, and the RRV-F. A subsample (n=21) also completed a laboratory food choice session. The online RRV-F instrument showed strong predictive validity for laboratory food choice behavior, convergent validity with overweight status, and discriminant validity with unrelated constructs (age, gender, height). Results suggest that online methodology is appropriate for assessing the RRV-F in a manner that is cost-effective, time-efficient, affords greater anonymity, and enables recruitment from larger samples over a broader geographic region. PMID:22664412

  15. Harvestable vibrational energy from an avian source: theoretical predictions vs. measured values

    NASA Astrophysics Data System (ADS)

    Shafer, Michael W.; MacCurdy, Robert; Garcia, Ephrahim; Winkler, David

    2012-04-01

    For many reasons, it would be beneficial to have the capability of powering a wildlife tag over the course of multiple migratory seasons. Such an energy harvesting system would allow for more data collection and eliminate the need to replace depleted batteries. In this work, we investigate energy harvesting on birds and focus on vibrational energy harvesting. We review a method of predicting the amount of power that can be safely harvested from the birds such that the effect on their longterm survivability is not compromised. After showing that the safely harvestable power is significant in comparison to the circuits used in avian tags, we present testing results for the flight accelerations of two species of birds. Using these measured values, we then design harvesters that matched the flight acceleration frequency and are sufficiently low mass to be carried by the birds.

  16. Deterministic Positive Operator Valued Measurements Performed Onto Remote Qubits via Partially Entangled States

    NASA Astrophysics Data System (ADS)

    Chen, LiBing; Lu, Hong

    2015-03-01

    We show how a remote positive operator valued measurement (POVM) can be implemented deterministically by using partially entangled state(s). Firstly, we present a theoretical scheme for implementing deterministically a remote and controlled POVM onto any one of N qubits via a partially entangled ( N + 1)-qubit Greenberger-Horne-Zeilinger (GHZ) state, in which ( N - 1) administrators are included. Then, we design another scheme for implementing deterministically a POVM onto N remote qubits via N partially entangled qubit pairs. Our schemes have been designed for obtaining the optimal success probabilities: i.e. they are identical to those in the ordinary, local, POVMs. In these schemes, the POVM dictates the amount of entanglement needed. The fact that such overall treatment can save quantum resources is notable.

  17. A sensitive, high resolution magic angle turning experiment for measuring chemical shift tensor principal values

    NASA Astrophysics Data System (ADS)

    Alderman, D. W.

    1998-12-01

    A sensitive, high-resolution 'FIREMAT' two-dimensional (2D) magic-angle-turning experiment is described that measures chemical shift tensor principal values in powdered solids. The spectra display spinning-sideband patterns separated by their isotropic shifts. The new method's sensitivity and high resolution in the isotropic-shift dimension result from combining the 5pi magic-angle-turning pulse sequence, an extension of the pseudo-2D sideband-suppression data rearrangement, and the TIGER protocol for processing 2D data. TPPM decoupling is used to enhance resolution. The method requires precise synchronization of the pulses and sampling to the rotor position. It is shown that the technique obtains 35 natural-abundance 13C tensors from erythromycin in 19 hours, and high quality naturalabundance 15N tensors from eight sites in potassium penicillin V in three days on a 400MHz spectrometer.

  18. Quantum Tasks with Non-maximally Quantum Channels via Positive Operator-Valued Measurement

    NASA Astrophysics Data System (ADS)

    Peng, Jia-Yin; Luo, Ming-Xing; Mo, Zhi-Wen

    2013-01-01

    By using a proper positive operator-valued measure (POVM), we present two new schemes for probabilistic transmission with non-maximally four-particle cluster states. In the first scheme, we demonstrate that two non-maximally four-particle cluster states can be used to realize probabilistically sharing an unknown three-particle GHZ-type state within either distant agent's place. In the second protocol, we demonstrate that a non-maximally four-particle cluster state can be used to teleport an arbitrary unknown multi-particle state in a probabilistic manner with appropriate unitary operations and POVM. Moreover the total success probability of these two schemes are also worked out.

  19. Prediction of breeding values for tenderness of market animals from measurements on bulls.

    PubMed

    Barkhouse, K L; Van Vleck, L D; Cundiff, L V; Koohmaraie, M; Lunstra, D D; Crouse, J D

    1996-11-01

    Data were tenderness measures on steaks from 237 bulls (Group II) slaughtered after producing freezable semen and on 1,431 related steers and heifers (market animals, Group I) from Angus, Hereford, Pinzgauer, Brahman, and Sahiwal crosses from the Germ Plasm Evaluation project at the U.S. Meat Animal Research Center. Tenderness was assessed through Warner-Bratzler Shear Force (SF), taste panel tenderness (TPT), marbling score (MS), and myofibrillar fragmentation index (MFI). For all traits, as fraction Bos indicus inheritance increased, implied tenderness decreased. Heritability estimates were generally not significantly different from zero. Genetic correlations generally indicated favorable associations among the traits. The range in predicted breeding values of bulls for market animal tenderness was small and from -.34 to .32 kg for market animal shear force. Because of low estimates of heritability for SF or TPT, results from this experiment indicate that selection based on tenderness of steaks sampled from intact or late castrate males slaughtered following collection of freezable quality semen would not be very effective in improving average tenderness of steaks from steers of heifer progeny. If a mean of heritability estimates reported in the literature of .27 for shear value was assumed for market steer and heifer progeny instead of .02 as found in the present study, then selection based on estimates of shear force in young bulls would be relatively more effective in improving shear force of market progeny. PMID:8923175

  20. Measuring the Value of Earth Observation Information with the Gravity Research and Climate Experiment (GRACE) Satellite

    NASA Astrophysics Data System (ADS)

    Bernknopf, R.; Kuwayama, Y.; Brookshire, D.; Macauley, M.; Zaitchik, B.; Pesko, S.; Vail, P.

    2014-12-01

    Determining how much to invest in earth observation technology depends in part on the value of information (VOI) that can be derived from the observations. We design a framework and then evaluate the value-in-use of the NASA Gravity Research and Climate Experiment (GRACE) for regional water use and reliability in the presence of drought. As a technology that allows measurement of water storage, the GRACE Data Assimilation System (DAS) provides information that is qualitatively different from that generated by other water data sources. It provides a global, reproducible grid of changes in surface and subsurface water resources on a frequent and regular basis. Major damages from recent events such as the 2012 Midwest drought and the ongoing drought in California motivate the need to understand the VOI from remotely sensed data such as that derived from GRACE DAS. Our conceptual framework models a dynamic risk management problem in agriculture. We base the framework on information from stakeholders and subject experts. The economic case for GRACE DAS involves providing better water availability information. In the model, individuals have a "willingness to pay" (wtp) for GRACE DAS - essentially, wtp is an expression of savings in reduced agricultural input costs and for costs that are influenced by regional policy decisions. Our hypothesis is that improvements in decision making can be achieved with GRACE DAS measurements of water storage relative to data collected from groundwater monitoring wells and soil moisture monitors that would be relied on in the absence of GRACE DAS. The VOI is estimated as a comparison of outcomes. The California wine grape industry has features that allow it to be a good case study and a basis for extrapolation to other economic sectors. We model water use in this sector as a sequential decision highlighting the attributes of GRACE DAS input as information for within-season production decisions as well as for longer-term water reliability.

  1. Characterization of P700 as a photochemical quencher in isolated Photosystem I particles using simultaneous measurements of absorbance changes at 830 nm and photoacoustic signal.

    PubMed

    Bukhov, Nikolai G; Rajagopal, Subramanyam; Carpentier, Robert

    2002-01-01

    The relationship between the redox state of P700, the primary donor of PS I, monitored using absorbance changes at 830 nm and photochemical energy storage in PS I reaction centers assayed with the photoacoustic method (PA) was studied in isolated PS I submembrane particles aspirated onto nitrocellulose filters. Several donors have been used to support the electron transport through PS I. NADPH and NADH demonstrated low rates of electron donation to PS I, while ascorbate and ascorbate plus 2,6-dichlorophenolindophenol (DCIP) couple have been found more effective in both P700(+) reduction and stimulation of the variable component of the PA signal. A linear relationship was found in isolated PS I particles between the (A(830,max) - A(830,steady))/A(830,max) and (PA(max) - PA(steady))/PA(max) ratios, which characterized the relative amount of P700 in the reduced state and the relative magnitude of the variable PA component, respectively. That linear relationship was obtained independently from the nature of electron donor used for the reduction of P700(+). Such linear relationship was also obtained at various wavelengths of modulated light in the range of 660 to 720 nm, only the slope of the linear fits varied with wavelength. It is concluded that reduced P700 act as a photochemical quencher of absorbed energy. Variable thermal dissipation in PS I reaction centers of isolated submembrane particles linearly depends on the amount of reduced P700 and thus constitutes an appropriate indicator of the redox pressure applied to PS I. PMID:16245140

  2. Perfect terahertz absorber using fishnet based metafilm

    SciTech Connect

    Azad, Abul Kalam; Shchegolkov, Dmitry Yu; Chen, Houtong; Taylor, Antoinette; Smirnova, E I; O' Hara, John F

    2009-01-01

    We present a perfect terahertz (THz) absorber working for a broad-angle of incidence. The two fold symmetry of rectangular fishnet structure allows either complete absorption or mirror like reflection depending on the polarization of incident the THz beam. Metamaterials enable the ability to control the electromagnetic wave in a unique fashion by designing the permittivity or permeability of composite materials with desired values. Although the initial idea of metamaterials was to obtain a negative index medium, however, the evolution of metamaterials (MMs) offers a variety of practically applicable devices for controlling electromagnetic wave such as tunable filters, modulators, phase shifters, compact antenna, absorbers, etc. Terahertz regime, a crucial domain of the electromagnetic wave, is suffering from the scarcity of the efficient devices and might take the advantage of metamaterials. Here, we demonstrate design, fabrication, and characterization of a terahertz absorber based on a simple fishnet metallic film separated from a ground mirror plane by a dielectric spacer. Such absorbers are in particular important for bolometric terahertz detectors, high sensitivity imaging, and terahertz anechoic chambers. Recently, split-ring-resonators (SRR) have been employed for metamaterial-based absorbers at microwave and THz frequencies. The experimental demonstration reveals that such absorbers have absorptivity close to unity at resonance frequencies. However, the downside of these designs is that they all employ resonators of rather complicated shape with many fine parts and so they are not easy to fabricate and are sensitive to distortions.

  3. Comparing results of an exact vs. an approximate (Bayesian) measurement invariance test: a cross-country illustration with a scale to measure 19 human values

    PubMed Central

    Cieciuch, Jan; Davidov, Eldad; Schmidt, Peter; Algesheimer, René; Schwartz, Shalom H.

    2014-01-01

    One of the most frequently used procedures for measurement invariance testing is the multigroup confirmatory factor analysis (MGCFA). Muthén and Asparouhov recently proposed a new approach to test for approximate rather than exact measurement invariance using Bayesian MGCFA. Approximate measurement invariance permits small differences between parameters otherwise constrained to be equal in the classical exact approach. However, extant knowledge about how results of approximate measurement invariance tests compare to the results of the exact measurement invariance test is missing. We address this gap by comparing the results of exact and approximate cross-country measurement invariance tests of a revised scale to measure human values. Several studies that measured basic human values with the Portrait Values Questionnaire (PVQ) reported problems of measurement noninvariance (especially scalar noninvariance) across countries. Recently Schwartz et al. proposed a refined value theory and an instrument (PVQ-5X) to measure 19 more narrowly defined values. Cieciuch et al. tested its measurement invariance properties across eight countries and established exact scalar measurement invariance for 10 of the 19 values. The current study applied the approximate measurement invariance procedure on the same data and established approximate scalar measurement invariance even for all 19 values. Thus, the first conclusion is that the approximate approach provides more encouraging results for the usefulness of the scale for cross-cultural research, although this finding needs to be generalized and validated in future research using population data. The second conclusion is that the approximate measurement invariance is more likely than the exact approach to establish measurement invariance, although further simulation studies are needed to determine more precise recommendations about how large the permissible variance of the priors may be. PMID:25249996

  4. Comparing results of an exact vs. an approximate (Bayesian) measurement invariance test: a cross-country illustration with a scale to measure 19 human values.

    PubMed

    Cieciuch, Jan; Davidov, Eldad; Schmidt, Peter; Algesheimer, René; Schwartz, Shalom H

    2014-01-01

    One of the most frequently used procedures for measurement invariance testing is the multigroup confirmatory factor analysis (MGCFA). Muthén and Asparouhov recently proposed a new approach to test for approximate rather than exact measurement invariance using Bayesian MGCFA. Approximate measurement invariance permits small differences between parameters otherwise constrained to be equal in the classical exact approach. However, extant knowledge about how results of approximate measurement invariance tests compare to the results of the exact measurement invariance test is missing. We address this gap by comparing the results of exact and approximate cross-country measurement invariance tests of a revised scale to measure human values. Several studies that measured basic human values with the Portrait Values Questionnaire (PVQ) reported problems of measurement noninvariance (especially scalar noninvariance) across countries. Recently Schwartz et al. proposed a refined value theory and an instrument (PVQ-5X) to measure 19 more narrowly defined values. Cieciuch et al. tested its measurement invariance properties across eight countries and established exact scalar measurement invariance for 10 of the 19 values. The current study applied the approximate measurement invariance procedure on the same data and established approximate scalar measurement invariance even for all 19 values. Thus, the first conclusion is that the approximate approach provides more encouraging results for the usefulness of the scale for cross-cultural research, although this finding needs to be generalized and validated in future research using population data. The second conclusion is that the approximate measurement invariance is more likely than the exact approach to establish measurement invariance, although further simulation studies are needed to determine more precise recommendations about how large the permissible variance of the priors may be. PMID:25249996

  5. Design of a magnetorheological automotive shock absorber

    NASA Astrophysics Data System (ADS)

    Lindler, Jason E.; Dimock, Glen A.; Wereley, Norman M.

    2000-06-01

    Double adjustable shock absorbers allow for independent adjustment of the yield force and post-yield damping in the force versus velocity response. To emulate the performance of a conventional double adjustable shock absorber, a magnetorheological (MR) automotive shock absorber was designed and fabricated at the University of Maryland. Located in the piston head, an applied magnetic field between the core and flux return increases the force required for a given piston rod velocity. Between the core and flux return, two different shaped gaps meet the controllable performance requirements of a double adjustable shock. A uniform gap between the core and the flux return primarily adjusts the yield force of the shock absorber, while a non-uniform gap allows for control of the post-yield damping. Force measurements from sinusoidal displacement cycles, recorded on a mechanical damper dynamometer, validate the performance of uniform and non- uniform gaps for adjustment of the yield force and post-yield damping, respectively.

  6. Durability of Polymeric Glazing and Absorber Materials

    SciTech Connect

    Jorgensen, G.; Terwilliger, K.; Bingham, C.; Milbourne, M.

    2005-01-01

    The Solar Heating and Lighting Program has set the goal of reducing the cost of solar water heating systems by at least 50%. An attractive approach to such large cost reduction is to replace glass and metal parts with less-expensive, lighter-weight, more-integrated polymeric components. The key challenge with polymers is to maintain performance and assure requisite durability for extended lifetimes. The objective of this task is to quantify lifetimes through measurement of the optical and mechanical stability of candidate polymeric glazing and absorber materials. Polycarbonate sheet glazings, as proposed by two industry partners, have been tested for resistance to UV radiation with three complementary methods. Incorporation of a specific 2-mil thick UV-absorbing screening layer results in glazing lifetimes of at least 15 years; improved screens promise even longer lifetimes. Proposed absorber materials were tested for creep and embrittlement under high temperature, and appear adequate for planned ICS absorbers.

  7. 36 CFR 223.64 - Appraisal on a lump-sum value or rate per unit of measure basis.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... or rate per unit of measure basis. 223.64 Section 223.64 Parks, Forests, and Public Property FOREST... Contracts Appraisal and Pricing § 223.64 Appraisal on a lump-sum value or rate per unit of measure basis. Timber may be appraised and sold at a lump-sum value or at a rate per unit of measure which rate may...

  8. Ionized Absorbers in AGN

    NASA Astrophysics Data System (ADS)

    Mathur, S.

    1999-08-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  9. Ionized Absorbers in AGN

    NASA Technical Reports Server (NTRS)

    Mathur, S.

    1999-01-01

    As a part of this program, we observed three AGN:PKS2251 + 113, PG0043 = 039 and PLH909. Two objects show signatures of absorbtion in their UV spectra. Based on our earlier modeling of X-ray warm absorbents, we expected to observe X-ray observation in these objects. The third, PLH909, is known to have soft excess in EINSTEIN data. Attachment: "Exploratory ASCA observation of broad absorption line quasi-stellar objects".

  10. Determination of decay coefficients for combustors with acoustic absorbers

    NASA Technical Reports Server (NTRS)

    Mitchell, C. E.; Espander, W. R.; Baer, M. R.

    1972-01-01

    An analytical technique for the calculation of linear decay coefficients in combustors with acoustic absorbers is presented. Tuned circumferential slot acoustic absorbers were designed for the first three transverse modes of oscillation, and decay coefficients for these absorbers were found as a function of backing distance for seven different chamber configurations. The effectiveness of the absorbers for off-design values of the combustion response and acoustic mode is also investigated. Results indicate that for tuned absorbers the decay coefficient increases approximately as the cube of the backing distance. For most off-design situations the absorber still provides a damping effect. However, if an absorber designed for some higher mode of oscillation is used to damp lower mode oscillations, a driving effect is frequently found.

  11. Determination of threshold value of soil water content for field and vegetable plants with lysimeter measurements

    NASA Astrophysics Data System (ADS)

    Knoblauch, S.

    2009-04-01

    Both the potential water consumption of plants and their ability to withdraw soil water are necessary in order to estimate actual evapotranspiration and to predict irrigation timing and amount. In relating to root water uptake the threshold value at which plants reducing evapotranspiration is an important parameter. Since transpiration is linearly correlated to dry matter production, under the condition that the AET/PET-Quotient is smaller than 1.0 (de Wit 1958, Tanner & Sinclair 1983), the dry matter production begins to decline too. Plants respond to drought with biochemical, physiological and morphological modifications in order to avoid damages, for instance by increasing the root water uptake. The objective of the study is to determine threshold values of soil water content and pressure head respectively for different field and vegetable plants with lysimeter measurements and to derive so called reduction functions. Both parameter, potenzial water demand in several growth stages and threshold value of soil water content or pressure head can be determined with weighable field lysimeter. The threshold value is reached, when the evapotranspiration under natural rainfall condition (AET) drop clearly (0.8 PET) below the value under well watered condition (PET). Basis for the presented results is the lysimeter plant Buttelstedt of the Thuringian State Institute of Agriculture. It consist of two lysimeter cellars, each with two weighable monolithic lysimeters. The lysimeter are 2.5 m deep with a surface area of 2 m2 to allow a non-restrictive root growth and to arrange a representative number of plants. The weighing accuracy amounts to 0.05 mm. The percolating water is collected by ceramic suction cups with suction up to 0.3 MPa at a depth of 2.3 m. The soil water content is measured by using neutron probe. One of the two lysimeter cellars represents the will irrigated, the other one the non irrigated and/or reduced irrigated part of field. The soil is a Haplic

  12. Enhancement mechanism of the additional absorbent on the absorption of the absorbing composite using a type-based mixing rule

    NASA Astrophysics Data System (ADS)

    Xu, Yonggang; Yuan, Liming; Zhang, Deyuan

    2016-04-01

    A silicone rubber composite filled with carbonyl iron particles and four different carbonous materials (carbon black, graphite, carbon fiber or multi-walled carbon nanotubes) was prepared using a two-roller mixture. The complex permittivity and permeability were measured using a vector network analyzer at the frequency of 2-18 GHz. Then a type-based mixing rule based on the dielectric absorbent and magnetic absorbent was proposed to reveal the enhancing mechanism on the permittivity and permeability. The enforcement effect lies in the decreased percolation threshold and the changing pending parameter as the carbonous materials were added. The reflection loss (RL) result showed the added carbonous materials enhanced the absorption in the lower frequency range, the RL decrement value being about 2 dB at 4-5 GHz with a thickness of 1 mm. All the added carbonous materials reinforced the shielding effectiveness (SE) of the composites. The maximum increment value of the SE was about 3.23 dB at 0.5 mm and 4.65 dB at 1 mm, respectively. The added carbonous materials could be effective additives for enforcing the absorption and shielding property of the absorbers.

  13. Comparison of actual evaporation from water surface measured by GGI-3000 evaporimeter with values calculated by the Penman equation

    NASA Astrophysics Data System (ADS)

    Kohu, Mojmír; Rožnovský, Jaroslav; Knozová, Grazyna

    2014-09-01

    Information about water evaporation is essential for the calculation of water balance. Evaporation, however, is a very complex physical process and it is therefore difficult to quantify. Evaporation measurements from the weather station network of the Czech Hydrometeorological Institute between 1968 and 2011 were performed using the evaporimeter GGI-3000. Evaporation was calculated using modified standard method based on FAO. The aim of the article was to compare the measured values and calculations. It has been found that the evaporation values from water surface calculated using the empirical equation are usually higher than the measured values by on average 0.8 mm, in extreme cases even 6.9 mm. The measured data shows higher variability than the calculated values, which means that correlations between series are not strong, the correlation coefficient being 0.7. Nevertheless the findings can be used for homogenization of series measured by the GGI-3000 evaporimeter.

  14. Reference dosimetry at the Australian Synchrotron's imaging and medical beamline using free-air ionization chamber measurements and theoretical predictions of air kerma rate and half value layer

    SciTech Connect

    Crosbie, Jeffrey C.; Rogers, Peter A. W.; Stevenson, Andrew W.; Hall, Christopher J.; Lye, Jessica E.; Nordstroem, Terese; Midgley, Stewart M.; Lewis, Robert A.

    2013-06-15

    Purpose: Novel, preclinical radiotherapy modalities are being developed at synchrotrons around the world, most notably stereotactic synchrotron radiation therapy and microbeam radiotherapy at the European Synchrotron Radiation Facility in Grenoble, France. The imaging and medical beamline (IMBL) at the Australian Synchrotron has recently become available for preclinical radiotherapy and imaging research with clinical trials, a distinct possibility in the coming years. The aim of this present study was to accurately characterize the synchrotron-generated x-ray beam for the purposes of air kerma-based absolute dosimetry. Methods: The authors used a theoretical model of the energy spectrum from the wiggler source and validated this model by comparing the transmission through copper absorbers (0.1-3.0 mm) against real measurements conducted at the beamline. The authors used a low energy free air ionization chamber (LEFAC) from the Australian Radiation Protection and Nuclear Safety Agency and a commercially available free air chamber (ADC-105) for the measurements. The dimensions of these two chambers are different from one another requiring careful consideration of correction factors. Results: Measured and calculated half value layer (HVL) and air kerma rates differed by less than 3% for the LEFAC when the ion chamber readings were corrected for electron energy loss and ion recombination. The agreement between measured and predicted air kerma rates was less satisfactory for the ADC-105 chamber, however. The LEFAC and ADC measurements produced a first half value layer of 0.405 {+-} 0.015 and 0.412 {+-} 0.016 mm Cu, respectively, compared to the theoretical prediction of 0.427 {+-} 0.012 mm Cu. The theoretical model based upon a spectrum calculator derived a mean beam energy of 61.4 keV with a first half value layer of approximately 30 mm in water. Conclusions: The authors showed in this study their ability to verify the predicted air kerma rate and x-ray attenuation

  15. Photon extremity absorbed dose and kerma conversion coefficients for calibration geometries.

    PubMed

    Veinot, K G; Hertel, N E

    2007-02-01

    Absorbed dose and dose equivalent conversion coefficients are routinely used in personnel dosimetry programs. These conversion coefficients can be applied to particle fluences or to measured air kerma values to determine appropriate operational monitoring quantities such as the ambient dose equivalent or personal dose equivalent for a specific geometry. For personnel directly handling materials, the absorbed dose to the extremities is of concern. This work presents photon conversion coefficients for two extremity calibration geometries using finger and wrist/arm phantoms described in HPS N13.32. These conversion coefficients have been calculated as a function of photon energy in terms of the kerma and the absorbed dose using Monte Carlo techniques and the calibration geometries specified in HPS N13.32. Additionally, kerma and absorbed dose conversion coefficients for commonly used x-ray spectra and calibration source fields are presented. The kerma values calculated in this work for the x-ray spectra and calibration sources compare well to those listed in HPS N13.32. The absorbed dose values, however, differ significantly for higher energy photons because charged particle equilibrium conditions have not been satisfied for the shallow depth. Thus, the air-kerma-to-dose and exposure-to-dose conversion coefficients for Cs and Co listed in HPS N13.32 overestimate the absorbed dose to the extremities. Applying the conversion coefficients listed in HPS N13.32 for Cs, for example, would result in an overestimate of absorbed dose of 62% for the finger phantom and 55% for the wrist phantom. PMID:17220720

  16. Absorber for terahertz radiation management

    DOEpatents

    Biallas, George Herman; Apeldoorn, Cornelis; Williams, Gwyn P.; Benson, Stephen V.; Shinn, Michelle D.; Heckman, John D.

    2015-12-08

    A method and apparatus for minimizing the degradation of power in a free electron laser (FEL) generating terahertz (THz) radiation. The method includes inserting an absorber ring in the FEL beam path for absorbing any irregular THz radiation and thus minimizes the degradation of downstream optics and the resulting degradation of the FEL output power. The absorber ring includes an upstream side, a downstream side, and a plurality of wedges spaced radially around the absorber ring. The wedges form a scallop-like feature on the innermost edges of the absorber ring that acts as an apodizer, stopping diffractive focusing of the THz radiation that is not intercepted by the absorber. Spacing between the scallop-like features and the shape of the features approximates the Bartlett apodization function. The absorber ring provides a smooth intensity distribution, rather than one that is peaked on-center, thereby eliminating minor distortion downstream of the absorber.

  17. Using UV-absorbance of intrinsic dithiothreitol (DTT) during RP-HPLC as a measure of experimental redox potential in vitro.

    PubMed

    Seo, Angie; Jackson, Janelle L; Schuster, Jolene V; Vardar-Ulu, Didem

    2013-07-01

    Many in-vitro experiments performed to study the response of thiol-containing proteins to changes in environmental redox potentials use dithiothreitol (DTT) to maintain a preset redox environment throughout the experiments. However, the gradual oxidation of DTT during the course of the experiments, and the interaction between DTT and other components in the system, can significantly alter the initial redox potential and complicate data interpretation. Having an internal reporter of the actual redox potential of the assayed sample facilitates direct correlation of biochemical findings with experimental redox status. Reversed-phase high-performance liquid chromatography (RP-HPLC) is a widely used, well-established tool for analysis and purification of biomolecules, including proteins and peptides. Here, we describe a simple, robust, and quantitative RP-HPLC method we developed and tested for determination of the experimental redox potential of an in-vitro sample at the time of the experiment. It exploits the specific UV-absorbance of the oxidized intrinsic DTT in the samples and retains the high resolving power and high sensitivity of RP-HPLC with UV detection. PMID:23743664

  18. On the air-entry value of porous media: New insights from measurements, imaging and pore scale modeling

    NASA Astrophysics Data System (ADS)

    Lehmann, Peter; Hoogland, Frouke; Or, Dani

    2016-04-01

    The air entry value is the capillary pressure associated with the formation of a continuous gas phase, hence marking the onset of unsaturated conditions in a porous medium. Near the air-entry value, transport properties change abruptly hence the importance of reliable determination of this value for modeling processes in the vadose zone. Typically, air entry value is inferred from the soil water characteristics of a porous sample subjected to step-wise increase in applied suction. This procedure is laborious and may require long equilibration times, and is difficult to apply for coarse media. We present an alternative and simpler method to deduce air entry-value from continuous evaporation from an initially saturated porous sample. As water evaporates and menisci form and penetrate the surface, the capillary pressure (measured with a tensiometer at any depth) abruptly changes and marks the macroscopic air entry value. This value remains remarkably constant during evaporation and receding drying front (after accounting for hydrostatic front position). We present experimental results from different porous media confirming that air-entry values deduced from soil water characteristics and evaporation experiments are similar. We employed pore scale imaging and network modeling to confirm that the air-entry value corresponds to the critical path that is needed to form a continuous air phase and its macroscopic value remains stable at a drying front that traverses a uniform porous medium. For layered media, corresponding adjustments in air entry values and air invasion patterns have been predicted and measured.

  19. Corrosion resistant neutron absorbing coatings

    SciTech Connect

    Choi, Jor-Shan; Farmer, Joseph C.; Lee, Chuck K.; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  20. Corrosion resistant neutron absorbing coatings

    SciTech Connect

    Choi, Jor-Shan; Farmer, Joseph C; Lee, Chuck K; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

    2013-11-12

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  1. Absorbance detection of amino acids by laser wave mixing in microbore liquid chromatography.

    PubMed

    Wu, Z; Tong, W G

    1998-05-01

    Nonlinear optical phase conjugation by degenerate four-wave mixing is demonstrated as a sensitive "absorbance" detection method for microbore high-performance liquid chromatography. An argon ion laser operating at the 488-nm line is used as the excitation light source to generate the wave-mixing signal for dabsyl-labeled amino acids. Advantages of the nonlinear laser detection method include: virtually 100% optical signal collection efficiency, generation of the signal in the form of a coherent laser beam, signal measurement against a virtually dark background, reliable detection of small absorbance values, excellent detection sensitivity for both fluorescing and non-fluorescing analytes, relatively simple one-color one-laser optical setup, and low power or energy requirements for continuous-wave or pulsed lasers. Using our one-laser one-color nonlinear laser detector for "absorbance" measurements in liquid chromatography, we report a crude preliminary "injected" detection limit of 780 fmol for glycine. PMID:9618915

  2. Implementation of Positive Operator-Valued Measure in Passive Faraday Mirror Attack

    NASA Astrophysics Data System (ADS)

    Wang, Wei-Long; Gao, Ming; Ma, Zhi

    2015-03-01

    Passive Faraday-mirror (PFM) attack is based on imperfect Faraday mirrors in practical quantum cryptography systems and a set of three-dimensional Positive Operator-Valued Measure (POVM) operators plays an important role in this attack. In this paper, we propose a simple scheme to implement the POVM in PFM attack on an Faraday-Michelson quantum cryptography system. Since the POVM can not be implemented directly with previous methods, in this scheme it needs to expand the states sent by Alice and the POVM operators in the attack into four-dimensional Hilbert space first, without changing the attacking effect by calculation. Based on the methods proposed by Ahnert and Payne, the linear-optical setup for implementing the POVM operators is derived. At last, the complete setup for realizing the PFM attack is presented with all parameters. Furthermore, our scheme can also be applied to realize PFM attack on a plug-and-play system by changing the parameters in the setup. Supported by National Natural Science Foundation of China under Grant Nos. 61472446, U1204602, and National High Technology Research and Development Program of China under Grant No. 2011AA010803, and the Open Project Program of the State Key Laboratory of Mathematical Engineering and Advanced Computing under Grant No. 2013A14

  3. Judging Surgical Research: How Should We Evaluate Performance and Measure Value?

    PubMed Central

    Souba, Wiley W.; Wilmore, Douglas W.

    2000-01-01

    Objective To establish criteria to evaluate performance in surgical research, and to suggest strategies to optimize research in the future. Summary Background Data Research is an integral component of the academic mission, focusing on important clinical problems, accounting for surgical advances, and providing training and mentoring for young surgeons. With constraints on healthcare resources, there is increasing pressure to generate clinical revenues at the expense of the time and effort devoted to surgical research. An approach that would assess the value of research would allow prioritization of projects. Further, alignment of high-priority research projects with clinical goals would optimize research gains and maximize the clinical enterprise. Methods The authors reviewed performance criteria applied to industrial research and modified these criteria to apply to surgical research. They reviewed several programs that align research objectives with clinical goals. Results Performance criteria were categorized along several dimensions: internal measures (quality, productivity, innovation, learning, and development), customer satisfaction, market share, and financial indices (cost and profitability). A “report card” was proposed to allow the assessment of research in an individual department or division. Conclusions The department’s business strategy can no longer be divorced from its research strategy. Alignment between research and clinical goals will maximize the department’s objectives but will create the need to modify existing hierarchical structures and reward systems. Such alignment appears to be the best way to ensure the success of surgical research in the future. PMID:10862192

  4. Ancilla dimensions needed to carry out positive-operator-valued measurement

    SciTech Connect

    Chen Pingxing; Bergou, Janos A.; Zhu Shiyao; Guo Guangcan

    2007-12-15

    To implement a positive-operator-valued measurement (POVM), which is defined on the d{sub S}-dimensional Hilbert space of a physical system, one has to extend the Hilbert space to include d{sub A} additional dimensions (called the ancilla). This is done via either the tensor product extension (TPE) or the direct sum extension (DSE). The implementation of a POVM utilizes the available resources more efficiently if it requires fewer additional dimensions. To determine how to implement a POVM with the least additional dimensions is, therefore, an important task in quantum information. We have determined the necessary and sufficient (hence minimal) number of the additional dimensions needed to implement the same POVM by the TPE and the DSE, respectively. If the POVM has n elements and r{sub i} is the rank of the ith element, then the dimension of the minimal ancilla is d{sub A}={sigma}{sub i=1}{sup n}r{sub i}-d{sub S} for the DSE implementation, and this represents a lower bound for the added dimensions in the TPE implementation. In the proof, we explicitly construct the DSE implementation of a general POVM with elements of arbitrary rank. As an example, we determine d{sub A} for the unambiguous discrimination of N linearly independent states and provide the full DSE implementation of a state-discriminating POVM for N=2.

  5. Solar radiation absorbing material

    DOEpatents

    Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.

    1977-01-01

    Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.

  6. Absorber for solar power.

    PubMed

    Powell, W R

    1974-10-01

    A simple, economical absorber utilizing a new principle of operation to achieve very low reradiation losses while generating temperatures limited by material properties of quartz is described. Its performance is analyzed and indicates approximately 90% thermal efficiency and 73% conversion efficiency for an earth based unit with moderately concentrated (~tenfold) sunlight incident. It is consequently compatible with the most economic of concentrator mirrors (stamped) or mirrors deployable in space. Space applications are particularly attractive, as temperatures significantly below 300 K are possible and permit even higher conversion efficiency. PMID:20134700

  7. RANS Simulation of the Heave Response of a Two-Body Floating Point Wave Absorber: Preprint

    SciTech Connect

    Yu, Y.; Li, Y.

    2011-03-01

    A preliminary study on a two-body floating wave absorbers is presented in this paper. A Reynolds-Averaged Navier-Stokes computational method is applied for analyzing the hydrodynamic heave response of the absorber in operational wave conditions. The two-body floating wave absorber contains a float section and a submerged reaction section. For validation purposes, our model is first assumed to be locked. The two sections are forced to move together with each other. The locked single body model is used in a heave decay test, where the RANS result is validated with the experimental measurement. For the two-body floating point absorber simulation, the two sections are connected through a mass-spring-damper system, which is applied to simulate the power take-off mechanism under design wave conditions. Overall, the details of the flow around the absorber and its nonlinear interaction with waves are investigated, and the power absorption efficiency of the two-body floating wave absorber in waves with a constant value spring-damper system is examined.

  8. A Practical Measure of Student Motivation: Establishing Validity Evidence for the Expectancy-Value-Cost Scale in Middle School

    ERIC Educational Resources Information Center

    Kosovich, Jeff J.; Hulleman, Chris S.; Barron, Kenneth E.; Getty, Steve

    2015-01-01

    We present validity evidence for the Expectancy-Value-Cost (EVC) Scale of student motivation. Using a brief, 10-item scale, we measured middle school students' expectancy, value, and cost for their math and science classes in the Fall and Winter of the same academic year. Confirmatory factor analyses supported the three-factor structure of the EVC…

  9. Preliminary Evaluation of the Values Tracker: A Two-Item Measure of Engagement in Valued Activities in Those With Chronic Pain.

    PubMed

    Pielech, Melissa; Bailey, Robert W; McEntee, Mindy L; Ashworth, Julie; Levell, Jayne; Sowden, Gail; Vowles, Kevin E

    2016-01-01

    Engagement in valued activities is an important outcome, particularly in treatments that aim to enhance quality of life in those with chronic conditions. The present study describes the initial evaluation of the Values Tracker (VT), a two-item measure of values engagement, in 302 treatment-seeking adults with chronic pain. Hierarchical regression analyses were conducted to examine the utility of the VT in the statistical prediction of pain-related functioning, after controlling for demographic variables, pain intensity, and pain-related distress. Across analyses, pain intensity accounted for significant variance (range ΔR2 = .06-.09) with pain-related distress adding additional unique variance (range ΔR2 = .07-.19). The VT accounted for additional unique variance (range ΔR2 = .02-.17) for all variables with the exception of physical disability. These findings provide initial support for the utility of the VT in those with chronic pain. Given the VT's brevity, it may be particularly useful for tracking changes in engagement in values across sessions. PMID:26611467

  10. Optical measurement of the pH value of intransparent samples under high pressure

    NASA Astrophysics Data System (ADS)

    Nagel, M.; Wierschem, A.; Rauh, C.; Delgado, A.

    2015-04-01

    We present a method to optically study the pH value of intransparent media under pressure. To this end, we prepare and use immobilized pH-value indicators. The indicators are brought into contact to the medium and their optical signal is read out in reflection with a spectrometer. The pH value and pressure response of the indicator were calibrated with imidazole buffers. As an example for its applicability to foodstuff, we study the pressure-induced pH-value change of fat and meat pastes.

  11. What Value "Value Added"?

    ERIC Educational Resources Information Center

    Richards, Andrew

    2015-01-01

    Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…

  12. Temporal, latitude and altitude absorbed dose dependences

    NASA Astrophysics Data System (ADS)

    Stozhkov, Y.; Svirzhevsky, N.; Bazilevskaya, G.

    The regular balloon measurements in the Earth's atmosphere are carried on at the Lebedev Physical Institute since 1957. The regular balloon flights have been made at the high latitude stations (near Murmansk - northern hemisphere and Mi ny -r Antarctica) and at the middle latitude (Moscow). Based on these long-term measurements as well as on the latitude data obtained in the several Soviet Antarctic expeditions the calculations of absorbed doses were fulfilled for altitudes of 10, 15, 20 and 30 km. The absorbed dose dependences on the geomagnetic cutoff rigidities and the phase of the 11-year solar cycle were found. The evaluation of the solar proton events and energetic electron precipitation contributions to the absorbed dose enhancements was made.

  13. An evaluation of the seasonal added value of downscaling over the United States using new verification measures

    NASA Astrophysics Data System (ADS)

    De Haan, Laurel L.; Kanamitsu, Masao; De Sales, Fernando; Sun, Liqiang

    2015-10-01

    Two separate dynamically downscaled ensembles are used to assess the added value of downscaling over the continental United States on a seasonal timescale. One data set is from a 55-year continuous run forced with observed sea surface temperatures. The other data set has downscaling results from seven regional models for 21 winters forced from a single coupled global model. The second data set, known as the Multi-RCM Ensemble Downscaling (MRED) project was used as a collection of individual models as well as a multi-model ensemble. The data was first tested for the potential loss of small-scale details due to averaging, and it was found that the number of small-scale details is not reduced when averaging over several models or several years. The added value of the downscaling was then calculated by standard measures, including climatology and correlation, as well as two newer measures: the added value index (AVI) and fraction skill score (FSS). The additional verification measures provided more information about the added value than was found with the standard measures. In general, more added value was found with the multi-model ensemble than with individual models. While it was clear that the added value was dependent on the forcing model, regional model, season, variable, and region, there were some areas where the downscale consistently added value, particularly near the coast and in topographically interesting areas.

  14. Measuring the Value Added by Technical Documentation: A Review of Research and Practice.

    ERIC Educational Resources Information Center

    Mead, Jay

    1998-01-01

    Reviews existing work on establishing value of technical documentation to determine its principles. States that value can be returned by reducing internal investment, increasing sales, and reducing after-sales costs. Argues that further research will improve the understanding of information as the product itself, rather than simply a supporting…

  15. The Value-Added of Primary Schools: What Is It Really Measuring?

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2008-01-01

    This paper compares the official value-added scores in 2005 for all primary schools in three adjacent Local Educational Authorities (LEAs) in England with the raw-score Key Stage 2 (KS2) results for the same schools. The correlation coefficient for the raw- and value-added scores of these 457 schools is around +0.75. Scatterplots show that there…

  16. When it comes to measuring value, few HMOs can make the grade.

    PubMed

    MacStravic, S

    2001-01-01

    Like all organizations, managed care organizations (MCOs) must deliver value to customers, and to be sure of keeping them, ensure those customers know they have gained value. MCOs can choose any mix of insurance, protection, or experience value from particular encounters with customers, or durable value from their relationship with customers. Many have done a good job of tracking and enabling employers to appreciate the impact they have had on business performance, but few have done the same for the health and quality-of-life they deliver to consumers. MCOs already participate in the delivery of significant and enduring life value to consumers. It makes sense to track and remind consumers of the positive differences MCOs make, and thereby obtain member satisfaction, retention, and loyalty benefits, as well as image improvements for managed care as a whole. Some simple and inexpensive options for both tracking and reminding consumers are offered for consideration, including personalized annual health reports. PMID:11252390

  17. The vexing problem of defining the meaning, role and measurement of values in treatment decision-making.

    PubMed

    Charles, Cathy; Gafni, Amiram

    2014-03-01

    Two international movements, evidence-based medicine (EBM) and shared decision-making (SDM) have grappled for some time with issues related to defining the meaning, role and measurement of values/preferences in their respective models of treatment decision-making. In this article, we identify and describe unresolved problems in the way that each movement addresses these issues. The starting point for this discussion is that at least two essential ingredients are needed for treatment decision-making: research information about treatment options and their potential benefits and risks; and the values/preferences of participants in the decision-making process. Both the EBM and SDM movements have encountered difficulties in defining the meaning, role and measurement of values/preferences in treatment decision-making. In the EBM model of practice, there is no clear and consistent definition of patient values/preferences and no guidance is provided on how to integrate these into an EBM model of practice. Methods advocated to measure patient values are also problematic. Within the SDM movement, patient values/preferences tend to be defined and measured in a restrictive and reductionist way as patient preferences for treatment options or attributes of options, while broader underlying value structures are ignored. In both models of practice, the meaning and expected role of physician values in decision-making are unclear. Values clarification exercises embedded in patient decision aids are suggested by SDM advocates to identify and communicate patient values/preferences for different treatment outcomes. Such exercises have the potential to impose a particular decision-making theory and/or process onto patients, which can change the way they think about and process information, potentially impeding them from making decisions that are consistent with their true values. The tasks of clarifying the meaning, role and measurement of values/preferences in treatment decision

  18. Metamaterial electromagnetic wave absorbers.

    PubMed

    Watts, Claire M; Liu, Xianliang; Padilla, Willie J

    2012-06-19

    The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed. PMID:22627995

  19. Absorber coatings' degradation

    SciTech Connect

    Moore, S.W.

    1984-01-01

    This report is intended to document some of the Los Alamos efforts that have been carried out under the Department of Energy (DOE) Active Heating and Cooling Materials Reliability, Maintainability, and Exposure Testing program. Funding for these activities is obtained directly from DOE although they represent a variety of projects and coordination with other agencies. Major limitations to the use of solar energy are the uncertain reliability and lifetimes of solar systems. This program is aimed at determining material operating limitations, durabilities, and failure modes such that materials improvements can be made and lifetimes can be extended. Although many active and passive materials and systems are being studied at Los Alamos, this paper will concentrate on absorber coatings and degradation of these coatings.

  20. Using value-based total cost of ownership (TCO) measures to inform subsystem trade-offs

    NASA Astrophysics Data System (ADS)

    Radziwill, Nicole M.; DuPlain, Ronald F.

    2010-07-01

    Total Cost of Ownership (TCO) is a metric from management accounting that helps expose both the direct and indirect costs of a business decision. However, TCO can sometimes be too simplistic for "make vs. buy" decisions (or even choosing between competing design alternatives) when value and extensibility are more critical than total cost. A three-dimensional value-based TCO, which was developed to clarify product decisions for an observatory prior to Final Design Review (FDR), will be presented in this session. This value-based approach incorporates priority of requirements, satisfiability of requirements, and cost, and can be easily applied in any environment.

  1. Estimating Time-Varying PCB Exposures Using Person-Specific Predictions to Supplement Measured Values: A Comparison of Observed and Predicted Values in Two Cohorts of Norwegian Women

    PubMed Central

    Nøst, Therese Haugdahl; Breivik, Knut; Wania, Frank; Rylander, Charlotta; Odland, Jon Øyvind; Sandanger, Torkjel Manning

    2015-01-01

    , Rylander C, Odland JØ, Sandanger TM. 2016. Estimating time-varying PCB exposures using person-specific predictions to supplement measured values: a comparison of observed and predicted values in two cohorts of Norwegian women. Environ Health Perspect 124:299–305; http://dx.doi.org/10.1289/ehp.1409191 PMID:26186800

  2. On the definition of absorbed dose

    NASA Astrophysics Data System (ADS)

    Grusell, Erik

    2015-02-01

    Purpose: The quantity absorbed dose is used extensively in all areas concerning the interaction of ionizing radiation with biological organisms, as well as with matter in general. The most recent and authoritative definition of absorbed dose is given by the International Commission on Radiation Units and Measurements (ICRU) in ICRU Report 85. However, that definition is incomplete. The purpose of the present work is to give a rigorous definition of absorbed dose. Methods: Absorbed dose is defined in terms of the random variable specific energy imparted. A random variable is a mathematical function, and it cannot be defined without specifying its domain of definition which is a probability space. This is not done in report 85 by the ICRU, mentioned above. Results: In the present work a definition of a suitable probability space is given, so that a rigorous definition of absorbed dose is possible. This necessarily includes the specification of the experiment which the probability space describes. In this case this is an irradiation, which is specified by the initial particles released and by the material objects which can interact with the radiation. Some consequences are discussed. Specific energy imparted is defined for a volume, and the definition of absorbed dose as a point function involves the specific energy imparted for a small mass contained in a volume surrounding the point. A possible more precise definition of this volume is suggested and discussed. Conclusions: The importance of absorbed dose motivates a proper definition, and one is given in the present work. No rigorous definition has been presented before.

  3. Development of singlet oxygen absorption capacity (SOAC) assay method. 3. Measurements of the SOAC values for phenolic antioxidants.

    PubMed

    Mukai, Kazuo; Ouchi, Aya; Takahashi, Shingo; Aizawa, Koichi; Inakuma, Takahiro; Terao, Junji; Nagaoka, Shin-ichi

    2012-08-15

    Measurements of the singlet oxygen ((1)O(2)) quenching rates (k(Q) (S)) and the relative singlet oxygen absortpion capacity (SOAC) values were performed for 16 phenolic antioxidants (tocopherol derivatives, ubiquinol-10, caffeic acids, and catechins) and vitamin C in ethanol/chloroform/D(2)O (50:50:1, v/v/v) solution at 35 °C. It has been clarified that the SOAC method is useful to evaluate the (1)O(2)-quenching activity of lipophilic and hydrophilic antioxidants having 5 orders of magnitude different rate constants from 1.38 × 10(10) M(-1) s(-1) for lycopene to 2.71 × 10(5) for ferulic acid. The logarithms of the k(Q) (S) and the SOAC values for phenolic antioxidants were found to correlate well with their peak oxidation potentials (E(p)); the antioxidants that have smaller E(p) values show higher reactivities. In previous works, measurements of the k(Q) (S) values for many phenolic antioxidants were performed in ethanol. Consequently, measurements of the k(Q) (S) and relative SOAC values were performed for eight carotenoids in ethanol to investigate the effect of solvent on the (1)O(2)-quenching rate. The k(Q) (S) values for phenolic antioxidants and carotenoids in ethanol were found to correlate linearly with the k(Q) (S) values in ethanol/chloroform/D(2)O solution with a gradient of 1.79, except for two catechins. As the relative rate constants (k(Q)(AO) (S)/k(Q)(α-Toc) (S)) of antioxidants (AO) are equal to the relative SOAC values, the SOAC values do not depend on the kinds of solvent used, if α-tocopherol is used as a standard compound. In fact, the SOAC values obtained for carotenoids in mixed solvent agreed well with the corresponding ones in ethanol. PMID:22823146

  4. Bias and spread in extreme value theory measurements of probability of error

    NASA Technical Reports Server (NTRS)

    Smith, J. G.

    1972-01-01

    Extreme value theory is examined to explain the cause of the bias and spread in performance of communications systems characterized by low bit rates and high data reliability requirements, for cases in which underlying noise is Gaussian or perturbed Gaussian. Experimental verification is presented and procedures that minimize these effects are suggested. Even under these conditions, however, extreme value theory test results are not particularly more significant than bit error rate tests.

  5. [Measurement of serum PA values by a newly developed enzyme immunoassay].

    PubMed

    Kuriyama, M; Esaki, N; Shinoda, I; Ito, S; Yamada, S; Tokuyama, K; Deguchi, T; Takahashi, Y; Kawada, Y; Akimoto, S

    1993-02-01

    Serum prostate-specific antigen (PA) values detected by a newly developed enzyme immunoassay (EIA, MARKIT-M PA) as a successor of MARKIT-F PA, which has been a leading kit in Japan, were evaluated for its role in the diagnosis of cancer of the prostate and follow-up of the patients afflicted with the disease. The system is one-step sandwich type EIA using horseradish peroxidase as a tracer and has 0.50-100 ng/ml of detectable range with small amount of sample volume (25 microliters) and reliable quality control data. Furthermore, serum PA values detected by the assay were almost equivocal to those detected by MARKIT-F PA. Serum PA values in prostate cancer patients (n = 122) were statistically higher than those in normal males (n = 90), urological malignancies other than prostate cancer (n = 48) or benign prostatic hypertrophy (BPH, n = 73). Even in the patients with stage A and B prostate cancer, serum PA values were observed to be statistically higher than those in BPH cases. If 3.6 ng/ml was used, which is normal value in MARKIT-F PA, as a cut-off value and BPH cases as a control, the sensitivity, specificity and efficacy for diagnosis of prostate cancer were 77.9, 91.8 and 83.1%, respectively, which showed the best results during the range examined. Serially determined serum PA values in following up the patients with prostate cancer were confirmed to be highly effective to evaluate treatment responses. These results suggest that MARKIT-M PA is thought to be one of the best tool for determination of serum PA values. PMID:7681886

  6. Warm Absorber Diagnostics of AGN Dynamics

    NASA Astrophysics Data System (ADS)

    Kallman, Timothy

    Warm absorbers and related phenomena are observable manifestations of outflows or winds from active galactic nuclei (AGN) that have great potential value. Understanding AGN outflows is important for explaining the mass budgets of the central accreting black hole, and also for understanding feedback and the apparent co-evolution of black holes and their host galaxies. In the X-ray band warm absorbers are observed as photoelectric absorption and resonance line scattering features in the 0.5-10 keV energy band; the UV band also shows resonance line absorption. Warm absorbers are common in low luminosity AGN and they have been extensively studied observationally. They may play an important role in AGN feedback, regulating the net accretion onto the black hole and providing mechanical energy to the surroundings. However, fundamental properties of the warm absorbers are not known: What is the mechanism which drives the outflow?; what is the gas density in the flow and the geometrical distribution of the outflow?; what is the explanation for the apparent relation between warm absorbers and the surprising quasi-relativistic 'ultrafast outflows' (UFOs)? We propose a focused set of model calculations that are aimed at synthesizing observable properties of warm absorber flows and associated quantities. These will be used to explore various scenarios for warm absorber dynamics in order to answer the questions in the previous paragraph. The guiding principle will be to examine as wide a range as possible of warm absorber driving mechanisms, geometry and other properties, but with as careful consideration as possible to physical consistency. We will build on our previous work, which was a systematic campaign for testing important class of scenarios for driving the outflows. We have developed a set of tools that are unique and well suited for dynamical calculations including radiation in this context. We also have state-of-the-art tools for generating synthetic spectra, which are

  7. Value-Added and Other Methods for Measuring School Performance: An Analysis of Performance Measurement Strategies in Teacher Incentive Fund Proposals. Research Brief

    ERIC Educational Resources Information Center

    National Center on Performance Incentives, 2008

    2008-01-01

    In "Value-Added and Other Methods for Measuring School Performance: An Analysis of Performance Measurement Strategies in Teacher Incentive Fund Proposals"--a paper presented at the February 2008 National Center on Performance Incentives research to policy conference--Robert Meyer and Michael Christian examine select performance-pay plans used by…

  8. Measuring Values-Based Environmental Concerns in Children: An Environmental Motives Scale

    ERIC Educational Resources Information Center

    Bruni, Coral M.; Chance, Randie C.; Schultz, P. Wesley

    2012-01-01

    The Environmental Motives Scale (EMS) was developed to measure an individual's concerns about environmental issues. The measure provides subscale scores for egoistic, social-altruistic, and biospheric concerns. Prior studies have shown a good fit for the 3-factor structure, but the measure has yet to be used with children. In this paper we report…

  9. Evaluation of the Acoustic Measurement Capability of the NASA Langley V/STOL Wind Tunnel Open Test Section with Acoustically Absorbent Ceiling and Floor Treatments

    NASA Technical Reports Server (NTRS)

    Theobald, M. A.

    1978-01-01

    The single source location used for helicopter model studies was utilized in a study to determine the distances and directions upstream of the model accurate at which measurements of the direct acoustic field could be obtained. The method used was to measure the decrease of sound pressure levels with distance from a noise source and thereby determine the Hall radius as a function of frequency and direction. Test arrangements and procedures are described. Graphs show the normalized sound pressure level versus distance curves for the glass fiber floor treatment and for the foam floor treatment.

  10. Prognostic value of blood flow measurements using arterial spin labeling in gliomas.

    PubMed

    Furtner, Julia; Bender, Benjamin; Braun, Christian; Schittenhelm, Jens; Skardelly, Marco; Ernemann, Ulrike; Bisdas, Sotirios

    2014-01-01

    The period of event-free survival (EFS) within the same histopathological glioma grades may have high variability, mainly without a known cause. The purpose of this study was to reveal the prognostic value of quantified tumor blood flow (TBF) values obtained by arterial spin labeling (ASL) for EFS in patients with histopathologically proven astrocytomas independent of WHO (World Health Organization) grade. Twenty-four patients with untreated gliomas underwent tumor perfusion quantification by means of pulsed ASL in 3T. The clinical history of the patients was retrospectively extracted from the local database. Six patients had to be excluded due to insufficent follow-up data for further evaluation or histopathologically verified oligodendroglioma tumor components. Receiver operating characteristic (ROC) curves were used to define an optimal cut-off value of maximum TBF (mTBF) values for subgrouping in low-perfused and high-perfused gliomas. Kaplan-Meier curves and Cox proportional hazard regression model were used to determine the prognostic value of mTBF for EFS. An optimal mTBF cut-off value of 182 ml/100 g/min (sensitivity  = 83%, specificity  = 100%) was determined. Patients with low-perfused gliomas had significantly longer EFS compared to patients with high-perfused gliomas (p = 0.0012) independent of the WHO glioma grade. Quantified mTBF values obtained by ASL offer a new and totally non-invasive marker to prognosticate the EFS, independently on histopathological tumor grading, in patients with gliomas. PMID:24911025

  11. Prognostic Value of Blood Flow Measurements Using Arterial Spin Labeling in Gliomas

    PubMed Central

    Furtner, Julia; Bender, Benjamin; Braun, Christian; Schittenhelm, Jens; Skardelly, Marco; Ernemann, Ulrike; Bisdas, Sotirios

    2014-01-01

    The period of event-free survival (EFS) within the same histopathological glioma grades may have high variability, mainly without a known cause. The purpose of this study was to reveal the prognostic value of quantified tumor blood flow (TBF) values obtained by arterial spin labeling (ASL) for EFS in patients with histopathologically proven astrocytomas independent of WHO (World Health Organization) grade. Twenty-four patients with untreated gliomas underwent tumor perfusion quantification by means of pulsed ASL in 3T. The clinical history of the patients was retrospectively extracted from the local database. Six patients had to be excluded due to insufficent follow-up data for further evaluation or histopathologically verified oligodendroglioma tumor components. Receiver operating characteristic (ROC) curves were used to define an optimal cut-off value of maximum TBF (mTBF) values for subgrouping in low-perfused and high-perfused gliomas. Kaplan-Meier curves and Cox proportional hazard regression model were used to determine the prognostic value of mTBF for EFS. An optimal mTBF cut-off value of 182 ml/100 g/min (sensitivity  = 83%, specificity  = 100%) was determined. Patients with low-perfused gliomas had significantly longer EFS compared to patients with high-perfused gliomas (p = 0.0012) independent of the WHO glioma grade. Quantified mTBF values obtained by ASL offer a new and totally non-invasive marker to prognosticate the EFS, independently on histopathological tumor grading, in patients with gliomas. PMID:24911025

  12. Incremental value of natriuretic peptide measurement in acute decompensated heart failure (ADHF): a systematic review.

    PubMed

    Santaguida, Pasqualina L; Don-Wauchope, Andrew C; Ali, Usman; Oremus, Mark; Brown, Judy A; Bustamam, Amy; Hill, Stephen A; Booth, Ronald A; Sohel, Nazmul; McKelvie, Robert; Balion, Cynthia; Raina, Parminder

    2014-08-01

    The aim of this systematic review was to determine whether B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) independently add incremental value for predicting mortality and morbidity in patients with acute decompensated heart failure (ADHF). Medline(®), Embase™, AMED, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and CINAHL were searched from 1989 to June 2012. We also searched reference lists of included articles, systematic reviews, and the gray literature. Studies were screened for eligibility criteria and assessed for risk of bias. Data were extracted on study design, population demographics, assay cutpoints, prognostic risk prediction model covariates, statistical methods, outcomes, and results. From 183 citations, only seven studies (5 BNP and 2 NT-proBNP) considered incremental value in ADHF subjects admitted to acute care centers. Admission assay levels and length of follow-up varied for BNP studies (31 days to 12 months) and for NT-proBNP studies (25-82 months). All studies presented at least one estimate of incremental value of BNP/NT-proBNP relative to the base prognostic model. Using discrimination or likelihood statistics, these studies consistently showed that BNP or NT-proBNP increased model performance. Three studies used reclassification and model validation computations to establish incremental value; these studies showed less consistency with respect to added value. In conclusion, the literature assessing incremental value of BNP/NT-proBNP in ADHF populations is limited to seven studies evaluating only mortality outcomes and at moderate risk of bias. Although there were differences in the base risk prediction models, assay cutpoints, and lengths of follow-up, there was consistency in BNP/NT-proBNP adding incremental value in prediction models in ADHF patients. PMID:25052418

  13. METHOD 415.3 - MEASUREMENT OF TOTAL ORGANIC CARBON, DISSOLVED ORGANIC CARBON AND SPECIFIC UV ABSORBANCE AT 254 NM IN SOURCE WATER AND DRINKING WATER

    EPA Science Inventory

    2.0 SUMMARY OF METHOD

    2.1 In both TOC and DOC determinations, organic carbon in the water sample is oxidized to form carbon dioxide (CO2), which is then measured by a detection system. There are two different approaches for the oxidation of organic carbon in water sample...

  14. Fine-Structure Measurements of Oxygen A Band Absorbance for Estimating the Thermodynamic Average Temperature of the Earth's Atmosphere: An Experiment in Physical and Environmental Chemistry

    ERIC Educational Resources Information Center

    Myrick, M. L.; Greer, A. E.; Nieuwland, A.; Priore, R. J.; Scaffidi, J.; Andreatta, Daniele; Colavita, Paula

    2006-01-01

    The experiment describe the measures of the A band transitions of atmospheric oxygen, a rich series of rotation-electronic absorption lines falling in the deep red portion of the optical spectrum and clearly visible owing to attenuation of solar radiation. It combines pure physical chemistry with analytical and environmental science and provides a…

  15. Electrochemically regenerable carbon dioxide absorber

    NASA Technical Reports Server (NTRS)

    Woods, R. R.; Marshall, R. D.; Schubert, F. H.; Heppner, D. B.

    1979-01-01

    Preliminary designs were generated for two electrochemically regenerable carbon dioxide absorber concepts. Initially, an electrochemically regenerable absorption bed concept was designed. This concept incorporated the required electrochemical regeneration components in the absorber design, permitting the absorbent to be regenerated within the absorption bed. This hardware was identified as the electrochemical absorber hardware. The second hardware concept separated the functional components of the regeneration and absorption process. This design approach minimized the extravehicular activity component volume by eliminating regeneration hardware components within the absorber. The electrochemical absorber hardware was extensively characterized for major operating parameters such as inlet carbon dioxide partial pressure, process air flow rate, operational pressure, inlet relative humidity, regeneration current density and absorption/regeneration cycle endurance testing.

  16. Broadband patterned magnetic microwave absorber

    SciTech Connect

    Li, Wei; Wu, Tianlong; Wang, Wei; Guan, Jianguo; Zhai, Pengcheng

    2014-07-28

    It is a tough task to greatly improve the working bandwidth for the traditional flat microwave absorbers because of the restriction of available material parameters. In this work, a simple patterning method is proposed to drastically broaden the absorption bandwidth of a conventional magnetic absorber. As a demonstration, an ultra-broadband microwave absorber with more than 90% absorption in the frequency range of 4–40 GHz is designed and experimentally realized, which has a thin thickness of 3.7 mm and a light weight equivalent to a 2-mm-thick flat absorber. In such a patterned absorber, the broadband strong absorption is mainly originated from the simultaneous incorporation of multiple λ/4 resonances and edge diffraction effects. This work provides a facile route to greatly extend the microwave absorption bandwidth for the currently available absorbing materials.

  17. How weak values emerge in joint measurements on cloned quantum systems.

    PubMed

    Hofmann, Holger F

    2012-07-13

    A statistical analysis of optimal universal cloning shows that it is possible to identify an ideal (but nonpositive) copying process that faithfully maps all properties of the original Hilbert space onto two separate quantum systems, resulting in perfect correlations for all observables. The joint probabilities for noncommuting measurements on separate clones then correspond to the real parts of the complex joint probabilities observed in weak measurements on a single system, where the measurements on the two clones replace the corresponding sequence of weak measurement and postselection. The imaginary parts of weak measurement statics can be obtained by replacing the cloning process with a partial swap operation. A controlled-swap operation combines both processes, making the complete weak measurement statistics accessible as a well-defined contribution to the joint probabilities of fully resolved projective measurements on the two output systems. PMID:23030138

  18. Absorber Materials at Room and Cryogenic Temperatures

    SciTech Connect

    F. Marhauser, T.S. Elliott, A.T. Wu, E.P. Chojnacki, E. Savrun

    2011-09-01

    We recently reported on investigations of RF absorber materials at cryogenic temperatures conducted at Jefferson Laboratory (JLab). The work was initiated to find a replacement material for the 2 Kelvin low power waveguide Higher Order Mode (HOM) absorbers employed within the original cavity cryomodules of the Continuous Electron Beam Accelerator Facility (CEBAF). This effort eventually led to suitable candidates as reported in this paper. Furthermore, though constrained by small funds for labor and resources, we have analyzed a variety of lossy ceramic materials, several of which could be usable as HOM absorbers for both normal conducting and superconducting RF structures, e.g. as loads in cavity waveguides and beam tubes either at room or cryogenic temperatures and, depending on cooling measures, low to high operational power levels.

  19. Perceived value of stroke outcome measures across the post-acute care continuum: a qualitative case study.

    PubMed

    Danzl, Megan M; Hunter, Elizabeth G

    2013-04-01

    Connecting the continuum of post-acute care stroke services may be important for easing patients' transition between settings and facilitating recovery and community reintegration. The use of outcome measures is suggested as one means of connecting the continuum. The purpose of this qualitative case study is to describe administrators' and physiotherapists' perceived value of an outcomes program across the post-acute care stroke continuum at a rehabilitation hospital. Data were collected through individual interviews and focus groups with 18 participants. Three themes emerged on the value of the outcomes program: 1) enhanced communication; 2) supports clinical decision-making; and 3) value of objective data. These findings lend support for the use of standardized outcome measures by physiotherapists in stroke rehabilitation. Findings from this study may be useful for organizations and physiotherapists who wish to integrate outcome measures into practice. PMID:23039017

  20. Precision QEC-value measurement of Mg23 for testing the Cabibbo-Kobayashi-Maskawa matrix unitarity

    NASA Astrophysics Data System (ADS)

    Schultz, B. E.; Brodeur, M.; Andreoiu, C.; Bader, A.; Chaudhuri, A.; Chowdhury, U.; Gallant, A. T.; Grossheim, A.; Klawitter, R.; Kwiatkowski, A. A.; Leach, K. G.; Lennarz, A.; Macdonald, T. D.; Lassen, J.; Heggen, H.; Raeder, S.; Teigelhöfer, A.; Dilling, J.

    2014-07-01

    We report a new direct measurement of the transition energy QEC of the Mg23 β+ decay, using the TITAN Penning-trap mass spectrometer. This value is found to agree with the latest atomic mass evaluation while being four times more precise. The increase in precision changes the uncertainty contribution of the QEC value on the statistical rate function fv from 11% to 0.6%, an improvement by a factor of 18. This enables a more robust determination of the corrected Ft value of this mirror transition to the required precision, making possible further test of the Cabibbo-Kobayashi-Maskawa matrix unitarity.

  1. Kinetic modeling of dissolution and crystallization of slurries with attenuated total reflectance UV-visible absorbance and near-infrared reflectance measurements.

    PubMed

    Hsieh, Chun H; Billeter, Julien; McNally, Mary Ellen P; Hoffman, Ronald M; Gemperline, Paul J

    2013-06-01

    Slurries are often used in chemical and pharmaceutical manufacturing processes but present challenging online measurement and monitoring problems. In this paper, a novel multivariate kinetic modeling application is described that provides calibration-free estimates of time-resolved profiles of the solid and dissolved fractions of a substance in a model slurry system. The kinetic model of this system achieved data fusion of time-resolved spectroscopic measurements from two different kinds of fiber-optic probes. Attenuated total reflectance UV-vis (ATR UV-vis) and diffuse reflectance near-infrared (NIR) spectra were measured simultaneously in a small-scale semibatch reactor. A simplified comprehensive kinetic model was then fitted to the time-resolved spectroscopic data to determine the kinetics of crystallization and the kinetics of dissolution for online monitoring and quality control purposes. The parameters estimated in the model included dissolution and crystal growth rate constants, as well as the dissolution rate order. The model accurately estimated the degree of supersaturation as a function of time during conditions when crystallization took place and accurately estimated the degree of undersaturation during conditions when dissolution took place. PMID:23565977

  2. Development of FeCoB/Graphene Oxide based microwave absorbing materials for X-Band region

    NASA Astrophysics Data System (ADS)

    Das, Sukanta; Chandra Nayak, Ganesh; Sahu, S. K.; Oraon, Ramesh

    2015-06-01

    This work explored the microwave absorption capability of Graphene Oxide and Graphene Oxide coated with FeCoB for stealth technology. Epoxy based microwave absorbing materials were prepared with 30% loading of Graphene Oxide, FeCoB alloy and Graphene Oxide coated with FeCoB. Graphene Oxide and FeCoB were synthesized by Hummer's and Co-precipitation methods, respectively. The filler particles were characterized by FESEM, XRD and Vibrating Sample Magnetometer techniques. Permittivity, permeability and reflection loss values of the composite absorbers were measured with vector network analyzer which showed a reflection loss value of -7.86 dB, at 10.72 GHz, for single layered Graphene Oxide/Epoxy based microwave absorbers which can be correlated to the absorption of about 83.97% of the incident microwave energy. Reflection loss value of FeCoB/Epoxy based microwave absorber showed -13.30 dB at 11.67 GHz, which corresponded to maximum absorption of 93.8%. However, reflection loss values of Graphene Oxide coated with FeCoB/Epoxy based single-layer absorber increased to -22.24 dB at 12.4 GHz which corresponds to an absorption of 99% of the incident microwave energy.

  3. Red bone marrow doses, integral absorbed doses, and somatically effective dose equivalent from four maxillary occlusal projections

    SciTech Connect

    Berge, T.I.; Wohni, T.

    1984-02-01

    Phantom measurements of red bone marrow (RBM) doses, integral absorbed doses, and somatically effective dose equivalent (SEDE) from four different maxillary occlusal projections are presented. For each projection, different combinations of focus-skin distances and tube potentials were compared with regard to the patient's radiation load. The axial incisal view produced the highest patient exposures, with a maximum red bone marrow dose of 122.5 microGy/exposure, integral absorbed dose of 8.6 mJ/exposure, and SEDE values of 39.6 microSv/exposure. The corresponding values from the frontal, lateral occlusal, and tuber views ranged between 4% and 44% of the axial incisal view values for the integral absorbed dose and SEDE values, and between 0.3% and 3% for the red bone marrow doses. Increasing the focus-skin distance from 17.5 cm to 27 cm is accompanied by a 24% to 30% reduction in integral absorbed dose. Increasing the tube potential from 50 kV to 65 kV likewise results in a 23% reduction in absorbed energy.

  4. Impact of the point spread function on maximum standardized uptake value measurements in patients with pulmonary cancer.

    PubMed

    Gellee, S; Page, J; Sanghera, B; Payoux, P; Wagner, Thomas

    2014-05-01

    Maximum standardized uptake value (SUVmax) from fluorodeoxyglucose (FDG) positron emission tomography (PET) scans is a semi quantitative measure that is increasingly used in the clinical practice for diagnostic and therapeutic response assessment purposes. Technological advances such as the implementation of the point spread function (PSF) in the reconstruction algorithm have led to higher signal to noise ratio and increased spatial resolution. The impact on SUVmax measurements has not been studied in clinical setting. We studied the impact of PSF on SUVmax in 30 consecutive lung cancer patients. SUVmax values were measured on PET-computed tomography (CT) scans reconstructed iteratively with and without PSF (respectively high-definition [HD] and non-HD). HD SUVmax values were significantly higher than non-HD SUVmax. There was excellent correlation between HD and non-HD values. Details of reconstruction and PSF implementation in particular have important consequences on SUV values. Nuclear Medicine physicians and radiologists should be aware of the reconstruction parameters of PET-CT scans when they report or rely on SUV measurements. PMID:25191128

  5. Dynamic vibration absorbers for vibration control within a frequency band

    NASA Astrophysics Data System (ADS)

    Yang, Cheng; Li, Deyu; Cheng, Li

    2011-04-01

    The use of dynamic vibration absorbers to control the vibration of a structure in both narrow and broadbands is discussed in this paper. As a benchmark problem, a plate incorporating multiple vibration absorbers is formulated, leading to an analytical solution when the number of absorbers yields one. Using this analytical solution, control mechanisms of the vibration absorber in different frequency bandwidths are studied; the coupling properties due to the introduction of the absorber into the host structure are analyzed; and the control performance of the absorber in different control bandwidths is examined with respect to its damping and location. It is found that the interaction between the plate and the absorber by means of the reaction force from the absorber plays a dominant role in a narrow band control, while in a relatively broadband control the dissipation by the absorber damping governs the control performance. When control bandwidth further enlarges, the optimal locations of the absorbers are not only affected by the targeted mode, but also by the other plate modes. These locations need to be determined after establishing a trade-off between the targeted mode and other modes involved in the coupling. Finally, numerical findings are assessed based on a simply-supported plate and a fair agreement between the predicted and measured results is obtained.

  6. Plants absorb heavy metals

    SciTech Connect

    Parry, J.

    1995-02-01

    Decontamination of heavy metals-polluted soils remains one of the most intractable problems of cleanup technology. Currently available techniques include extraction of the metals by physical and chemical means, such as acid leaching and electroosmosis, or immobilization by vitrification. There are presently no techniques for cleanup which are low cost and retain soil fertility after metals removal. But a solution to the problem could be on the horizon. A small but growing number of plants native to metalliferous soils are known to be capable of accumulating extremely high concentrations of metals in their aboveground portions. These hyperaccumulators, as they are called, contain up to 1,000 times larger metal concentrations in their aboveground parts than normal species. Their distribution is global, including many different families of flowering plants of varying growth forms, from herbaceous plants to trees. Hyperaccumulators absorb metals they do not need for their own nutrition. The metals are accumulated in the leaf and stem vacuoles, and to a lesser extent in the roots.

  7. Value-Added and Observational Measures Used in the Teacher Evaluation Process: A Validation Study

    ERIC Educational Resources Information Center

    Guerere, Claudia

    2013-01-01

    Scores from value-added models (VAMs), as used for educational accountability, represent the educational effect teachers have on their students. The use of these scores in teacher evaluations for high-stakes decision making is new for the State of Florida. Validity evidence that supports or questions the use of these scores is critically needed.…

  8. An Evaluation of Empirical Bayes' Estimation of Value- Added Teacher Performance Measures. Working Paper #31. Revised

    ERIC Educational Resources Information Center

    Guarino, Cassandra M.; Maxfield, Michelle; Reckase, Mark D.; Thompson, Paul; Wooldridge, Jeffrey M.

    2014-01-01

    Empirical Bayes' (EB) estimation is a widely used procedure to calculate teacher value-added. It is primarily viewed as a way to make imprecise estimates more reliable. In this paper we review the theory of EB estimation and use simulated data to study its ability to properly rank teachers. We compare the performance of EB estimators with that of…

  9. Can Value-Added Measures of Teacher Performance Be Trusted? Working Paper #18

    ERIC Educational Resources Information Center

    Guarino, Cassandra M.; Reckase, Mark D.; Woolridge, Jeffrey M.

    2012-01-01

    We investigate whether commonly used value-added estimation strategies can produce accurate estimates of teacher effects. We estimate teacher effects in simulated student achievement data sets that mimic plausible types of student grouping and teacher assignment scenarios. No one method accurately captures true teacher effects in all scenarios,…

  10. An Evaluation of Empirical Bayes's Estimation of Value-Added Teacher Performance Measures

    ERIC Educational Resources Information Center

    Guarino, Cassandra M.; Maxfield, Michelle; Reckase, Mark D.; Thompson, Paul N.; Wooldridge, Jeffrey M.

    2015-01-01

    Empirical Bayes's (EB) estimation has become a popular procedure used to calculate teacher value added, often as a way to make imprecise estimates more reliable. In this article, we review the theory of EB estimation and use simulated and real student achievement data to study the ability of EB estimators to properly rank teachers. We compare the…

  11. The Value of International Experiences for Business Students: Measuring Business Student Attitudes toward Study Abroad

    ERIC Educational Resources Information Center

    Heffron, Sean; Maresco, Peter A.

    2014-01-01

    The value of an international experience--especially for students of business--continues to be an area of focus at colleges and universities. Students across all disciplines within the business curriculum: accounting, economics, finance, management, marketing, or sport management are expected by employers to possess knowledge of, and appreciation…

  12. Discrepancy between Atwater factor predicted and empirically measured energy value of almonds in human diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy content of foods is primarily determined by the Atwater factors, which may not be accurate for certain food groups. Nuts are a food group for which evidence suggests that the Atwater factors may be poorly predictive. The objective of this study was to determine the energy value of almonds i...

  13. Measuring the Economic Value of the Electronic Scientific Information Services in Portuguese Academic Libraries

    ERIC Educational Resources Information Center

    Melo, Luiza Baptista; Pires, Cesaltina Pacheco

    2011-01-01

    This article has three main objectives: i) to describe the use patterns of electronic and traditional resources in Portuguese academic libraries; ii) to estimate the value of the Portuguese electronic scientific information consortium b-on by using two alternative valuation methodologies; iii) to relate the use patterns with the valuation of b-on.…

  14. Measuring School and Teacher Value Added in DC, 2011-2012 School Year: Final Report

    ERIC Educational Resources Information Center

    Isenberg, Eric; Hock, Heinrich

    2012-01-01

    This report describes the value-added models used as part of teacher evaluation systems in the District of Columbia Public Schools (DCPS) and in eligible DC charter schools participating in "Race to the Top." The authors estimated: (1) teacher effectiveness in DCPS and eligible DC charter schools during the 2011-2012 school year; and (2)…

  15. Measuring School and Teacher Value Added in DC, 2011-2012 School Year. Final Report

    ERIC Educational Resources Information Center

    Isenberg, Eric; Hock, Heinrich

    2012-01-01

    In this report, the authors describe the value-added models used as part of teacher evaluation systems in the District of Columbia Public Schools (DCPS) and in eligible DC charter schools participating in Race to the Top. They estimated (1) teacher effectiveness in DCPS and eligible DC charter schools during the 2011-2012 school year; and (2)…

  16. Estimation of actual evapotranspiration using measured and calculated values of bulk surface resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently the United Nations-Food and Agriculture Organization (FAO) recommends using the Penman-Monteith method for estimating ET over all other meteorological methods. The principal limitation of using the generalized form of the Penman-Monteith equation is in obtaining accurate values for the bu...

  17. The Promise and Peril of Using Value-Added Modeling to Measure Teacher Effectiveness. Research Brief

    ERIC Educational Resources Information Center

    RAND Corporation, 2004

    2004-01-01

    Value-added modeling offers the possibility of estimating the effects of teachers and schools on student performance, a potentially important contribution in the current environment of concern for accountability in education. These techniques, however, are susceptible to a number of sources of bias, depending on decisions about how the modeling is…

  18. Relevance of methods and standards for the assessment of measurement system performance in a High-Value Manufacturing Industry

    NASA Astrophysics Data System (ADS)

    Loftus, Pete; Giudice, Seb

    2014-08-01

    Measurements underpin the engineering decisions that allow products to be designed, manufactured, operated, and maintained. Therefore, the quality of measured data needs to be systematically assured to allow decision makers to proceed with confidence. The use of standards is one way of achieving this. This paper explores the relevance of international documentary standards to the assessment of measurement system capability in High Value Manufacturing (HVM) Industry. An internal measurement standard is presented which supplements these standards and recommendations are made for a cohesive effort to develop the international standards to provide consistency in such industrial applications.

  19. SU-E-I-19: CTDI Values for All Protocols: Using the Ratio of the DLP Measured in CTDI Phantoms to the Measured Air Exposure

    SciTech Connect

    Raterman, G; Gauntt, D

    2014-06-01

    Purpose: To propose a method other than CTDI phantom measurements for routine CT dosimetry QA. This consists of taking a series of air exposure measurements and calculating a factor for converting from this exposure measurement to the protocol's associated head or body CTDI value using DLP. The data presented are the ratios of phantom DLP to air exposure ratios for different scanners, as well as error in the displayed CTDI. Methods: For each scanner, the CTDI is measured at all available tube voltages using both the head and body phantoms. Then, the exposure is measured using a pencil chamber in air at isocenter. A ratio of phantom DLP to exposure in air for a given protocol may be calculated and used for converting a simple air dose measurement to a head or body CTDI value. For our routine QA, the exposure in air for different collimations, mAs, and kVp is measured, and displayed CTDI is recorded. Therefore, the ratio calculated may convert these exposures to CTDI values that may then be compared to the displayed CTDI for a large range of acquisition parameter combinations. Results: It was found that all scanners tend to have a ratio factor that slightly increases with kVp. Also, Philips scanners appear to have less of a dependence on kVp; whereas, GE scanners have a lower ratio at lower kVp. The use of air exposure times the DLP conversion yielded CTDI values that were less than 10% different from the displayed CTDI on several scanners. Conclusion: This method may be used as a primary method for CT dosimetry QA. As a result of the ease of measurement, a dosimetry metric specific to that scanner may be calculated for a wide variety of CT protocols, which could also be used to monitor display CTDI value accuracy.

  20. Measuring the Subjective Value of Risky and Ambiguous Options using Experimental Economics and Functional MRI Methods

    PubMed Central

    Levy, Ifat; Rosenberg Belmaker, Lior; Manson, Kirk; Tymula, Agnieszka; Glimcher, Paul W.

    2012-01-01

    Most of the choices we make have uncertain consequences. In some cases the probabilities for different possible outcomes are precisely known, a condition termed "risky". In other cases when probabilities cannot be estimated, this is a condition described as "ambiguous". While most people are averse to both risk and ambiguity1,2, the degree of those aversions vary substantially across individuals, such that the subjective value of the same risky or ambiguous option can be very different for different individuals. We combine functional MRI (fMRI) with an experimental economics-based method3 to assess the neural representation of the subjective values of risky and ambiguous options4. This technique can be now used to study these neural representations in different populations, such as different age groups and different patient populations. In our experiment, subjects make consequential choices between two alternatives while their neural activation is tracked using fMRI. On each trial subjects choose between lotteries that vary in their monetary amount and in either the probability of winning that amount or the ambiguity level associated with winning. Our parametric design allows us to use each individual's choice behavior to estimate their attitudes towards risk and ambiguity, and thus to estimate the subjective values that each option held for them. Another important feature of the design is that the outcome of the chosen lottery is not revealed during the experiment, so that no learning can take place, and thus the ambiguous options remain ambiguous and risk attitudes are stable. Instead, at the end of the scanning session one or few trials are randomly selected and played for real money. Since subjects do not know beforehand which trials will be selected, they must treat each and every trial as if it and it alone was the one trial on which they will be paid. This design ensures that we can estimate the true subjective value of each option to each subject. We then

  1. Making an honest measurement scale out of the oxygen isotope delta-values.

    PubMed

    Gat, Joel R; DeBievre, Paul

    2002-01-01

    The differential measurement of the abundance of oxygen isotopes based on reference materials, such as VSMOW for the case of water, was used because the precision of the absolute mass-spectrometric determination of the abundance fell short of the differences to be measured. Since then these measurements have been much improved, so that a calibration scheme of the oxygen isotope abundance in water, carbonates, silica, phosphates, sulfates, nitrates and organic materials is suggested, based on an accredited primary standard of oxygen in air and using standard fluorination and O(2) to CO(2) conversion techniques. PMID:12442297

  2. The value of volume and growth measurements in timber sales management of the National Forests

    NASA Technical Reports Server (NTRS)

    Lietzke, K. R.

    1977-01-01

    This paper summarizes work performed in the estimation of gross social value of timber volume and growth rate information used in making regional harvest decisions in the National Forest System. A model was developed to permit parametric analysis. The problem is formulated as one of finding optimal inventory holding patterns. Public timber management differs from other inventory holding problems in that the inventory, itself, generates value over time in providing recreational, aesthetic and environmental goods. 'Nontimber' demand estimates are inferred from past Forest Service harvest and sales levels. The solution requires a description of the harvest rates which maintain the optimum inventory level. Gross benefits of the Landsat systems are estimated by comparison with Forest Service information gathering models. Gross annual benefits are estimated to be $5.9 million for the MSS system and $7.2 million for the TM system.

  3. Measuring the value of air quality: application of the spatial hedonic model.

    PubMed

    Kim, Seung Gyu; Cho, Seong-Hoon; Lambert, Dayton M; Roberts, Roland K

    2010-03-01

    This study applies a hedonic model to assess the economic benefits of air quality improvement following the 1990 Clean Air Act Amendment at the county level in the lower 48 United States. An instrumental variable approach that combines geographically weighted regression and spatial autoregression methods (GWR-SEM) is adopted to simultaneously account for spatial heterogeneity and spatial autocorrelation. SEM mitigates spatial dependency while GWR addresses spatial heterogeneity by allowing response coefficients to vary across observations. Positive amenity values of improved air quality are found in four major clusters: (1) in East Kentucky and most of Georgia around the Southern Appalachian area; (2) in a few counties in Illinois; (3) on the border of Oklahoma and Kansas, on the border of Kansas and Nebraska, and in east Texas; and (4) in a few counties in Montana. Clusters of significant positive amenity values may exist because of a combination of intense air pollution and consumer awareness of diminishing air quality. PMID:20376167

  4. The thermal instability of the warm absorber in NGC 3783

    NASA Astrophysics Data System (ADS)

    Goosmann, R. W.; Holczer, T.; Mouchet, M.; Dumont, A.-M.; Behar, E.; Godet, O.; Gonçalves, A. C.; Kaspi, S.

    2016-05-01

    Context. The X-ray absorption spectra of active galactic nuclei frequently show evidence of winds with velocities in the order of 103 km s-1 extending up to 104 km s-1 in the case of ultra-fast outflows. At moderate velocities, these winds are often spectroscopically explained by assuming a number of absorbing clouds along the line of sight. In some cases it was shown that the absorbing clouds are in pressure equilibrium with each other. Aims: We assume a photo-ionized medium with a uniform total (gas+radiation) pressure. The irradiation causes the wind to be radiation pressure compressed (RPC). We attempt to reproduce the observed spectral continuum shape, ionic column densities, and X-ray absorption measure distribution (AMD) of the extensively observed warm absorber in the Seyfert galaxy NGC 3783. Methods: We compare the observational characteristics derived from the 900 ks Chandra observation to radiative transfer computations in pressure equilibrium using the radiative transfer code titan. We explore different values of the ionization parameter ξ of the incident flux and adjust the hydrogen-equivalent column density, NH0, of the warm absorber to match the observed soft X-ray continuum. From the resulting models we derive the column densities for a broad range of ionic species of iron and neon and a theoretical AMD that we compare to the observations. Results: We find an extension of the degeneracy between ξ and NH0 for the constant pressure models previously discussed for NGC 3783. Including the ionic column densities of iron and neon in the comparison between observations and data we conclude that a range of ionization parameters between 4000 and 8000 erg cm s-1 is preferred. For the first time, we present theoretical AMDs for a constant pressure wind in NGC 3783 that correctly reproduces the observed level and is in approximate agreement with the observational appearance of an instability region. Conclusions: Using a variety of observational indicators, we

  5. Energy absorber for the CETA

    NASA Astrophysics Data System (ADS)

    Wesselski, Clarence J.

    1994-05-01

    The energy absorber that was developed for the CETA (Crew Equipment and Translation Aid) on Space Station Freedom is a metal on metal frictional type and has a load regulating feature that prevents excessive stroking loads from occurring while in operation. This paper highlights some of the design and operating aspects and the testing of this energy absorber.

  6. Energy absorber for the CETA

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J.

    1994-01-01

    The energy absorber that was developed for the CETA (Crew Equipment and Translation Aid) on Space Station Freedom is a metal on metal frictional type and has a load regulating feature that prevents excessive stroking loads from occurring while in operation. This paper highlights some of the design and operating aspects and the testing of this energy absorber.

  7. Metal-shearing energy absorber

    NASA Technical Reports Server (NTRS)

    Fay, R. J.; Wittrock, E. P.

    1971-01-01

    Device, consisting of tongue of thin aluminum alloy strip, pull tab, slotted steel plate which serves as cutter, and steel buckle, absorbs mechanical energy when its ends are subjected to tensile loading. Device is applicable as auxiliary shock absorbing anchor for automobile and airplane safety belts.

  8. Photochromic And Thermochromic Pigments For Solar Absorbing-Reflecting Coatings

    NASA Astrophysics Data System (ADS)

    Novinson, Thomas

    1987-11-01

    Both photochromic and thermochromic compounds were synthesized and physical measurements were made to determine coefficients of relectance, absorbance and emission. The most interesting group of thermochromic compounds are related to silver tctraiodomercurate and the most interesting photochromic compounds are substituted benzoindolinopyrospirans. The synthesis and optical reflectance and absorbance properties of other classes of compounds are also reported.

  9. Measuring Value Added School Effects on Ohio Six-Grade Proficiency Test Results Using Two-Level Hierarchical Linear Modeling.

    ERIC Educational Resources Information Center

    Yu, Lei; White, Donald B.

    This study was conducted to measure value added school effects in a Northwest urban public school district using a two-level hierarchical model. The model consisted of two student-level variables (prior achievement and eligibility for federal free or reduced-price lunch) and three school variables (percentage of students eligible for free or…

  10. Validation of the Consumer Values versus Perceived Product Attributes Model Measuring the Purchase of Athletic Team Merchandise

    ERIC Educational Resources Information Center

    Lee, Donghun; Byon, Kevin K.; Schoenstedt, Linda; Johns, Gary; Bussell, Leigh Ann; Choi, Hwansuk

    2012-01-01

    Various consumer values and perceived product attributes trigger consumptive behaviors of athletic team merchandise (Lee, Trail, Kwon, & Anderson, 2011). Likewise, using a principal component analysis technique on a student sample, a measurement scale was proposed that consisted of nine factors affecting the purchase of athletic team merchandise.…

  11. Correlation between environmental relative moldiness index (ERMI) values in French dwellings and other measures of fungal contamination

    EPA Science Inventory

    The Environmental Relative Moldiness Index (ERMI) is a DNA-based metric developed to describe the fungal contamination in US dwellings. Our goal was to determine if the ERMI values in dwellings in north western France were correlated with other measures of fungal contamination. D...

  12. Effectiveness Measures for Cross-Sectional Studies: A Comparison of Value-Added Models and Contextualised Attainment Models

    ERIC Educational Resources Information Center

    Lenkeit, Jenny

    2013-01-01

    Educational effectiveness research often appeals to "value-added models (VAM)" to gauge the impact of schooling on student learning net of the effect of student background variables. A huge amount of cross-sectional studies do not, however, meet VAM's requirement for longitudinal data. "Contextualised attainment models (CAM)" measure the influence…

  13. Visible light broadband perfect absorbers

    NASA Astrophysics Data System (ADS)

    Jia, X. L.; Meng, Q. X.; Yuan, C. X.; Zhou, Z. X.; Wang, X. O.

    2016-03-01

    The visible light broadband perfect absorbers based on the silver (Ag) nano elliptical disks and holes array are studied using finite difference time domain simulations. The semiconducting indium silicon dioxide thin film is introduced as the space layer in this sandwiched structure. Utilizing the asymmetrical geometry of the structures, polarization sensitivity for transverse electric wave (TE)/transverse magnetic wave (TM) and left circular polarization wave (LCP)/right circular polarization wave (RCP) of the broadband absorption are gained. The absorbers with Ag nano disks and holes array show several peaks absorbance of 100% by numerical simulation. These simple and flexible perfect absorbers are particularly desirable for various potential applications including the solar energy absorber.

  14. Challenges in Measuring Cost and Value in Oncology: Making It Personal.

    PubMed

    Yu, Peter P

    2016-01-01

    Oncology patients often find themselves facing an incurable disease with limited treatment options and increasing patient fragility. The importance of patient preferences and values increases in shared decision making especially when the cost of cancer care is continuing its steep rise. As our understanding of cancer systems biology increases, we are justifiably optimistic about therapeutic improvements but recognize that this has complicated the traditional Food and Drug Administration approval of drug indications based on organ-specific cancer for a particular drug. Dynamic and agile clinical guidelines that reflect a rapidly changing knowledge base for decision-making support are needed. The American Society of Clinical Oncology (ASCO) has been working on three initiatives to tackle these complex issues. The first initiative is ASCO's collaboration with other international organizations to create a framework to assess drugs for the World Health Organization's Essential Medicines List, including nongenerics. The second initiative aims to define clinically meaningful outcomes as precision medicine expands the definition of cancers, leading to increased demand for the use of targeted drugs as single agents or in combination. The third initiative is ASCO's value framework, published in 2015, focusing on patient-physician shared decision making. The framework incorporates three parameters: 1) the meaningfulness of the clinical benefit, 2) the toxicity of the treatment, and 3) the patient's financial out-of-pocket cost. ASCO is concerned about the rising cost of cancer care when the clinical complexity and the pace of change in oncology are accelerating, and it is committed to help improve patient outcomes and value in cancer care as well as to engage the broader health care community in a process of collaborative improvement. PMID:27565267

  15. Measuring value for money: a scoping review on economic evaluation of health information systems

    PubMed Central

    Bassi, Jesdeep; Lau, Francis

    2013-01-01

    Objective To explore how key components of economic evaluations have been included in evaluations of health information systems (HIS), to determine the state of knowledge on value for money for HIS, and provide guidance for future evaluations. Materials and methods We searched databases, previously collected papers, and references for relevant papers published from January 2000 to June 2012. For selection, papers had to: be a primary study; involve a computerized system for health information processing, decision support, or management reporting; and include an economic evaluation. Data on study design and economic evaluation methods were extracted and analyzed. Results Forty-two papers were selected and 33 were deemed high quality (scores ≥8/10) for further analysis. These included 12 economic analyses, five input cost analyses, and 16 cost-related outcome analyses. For HIS types, there were seven primary care electronic medical records, six computerized provider order entry systems, five medication management systems, five immunization information systems, four institutional information systems, three disease management systems, two clinical documentation systems, and one health information exchange network. In terms of value for money, 23 papers reported positive findings, eight were inconclusive, and two were negative. Conclusions We found a wide range of economic evaluation papers that were based on different assumptions, methods, and metrics. There is some evidence of value for money in selected healthcare organizations and HIS types. However, caution is needed when generalizing these findings. Better reporting of economic evaluation studies is needed to compare findings and build on the existing evidence base we identified. PMID:23416247

  16. CAP waveform estimation from the measured electrical bioimpedance values: Patient's heart rate variability analysis.

    PubMed

    Krivoshei, A; Uuetoa, H; Min, M; Annus, P; Uuetoa, T; Lamp, J

    2015-08-01

    The paper presents analysis of the generic transfer function (TF) between Electrical Bioimpedance (EBI) measured non-invasively on the wrist and Central Aortic Pressure (CAP) invasively measured at the aortic root. Influence of the Heart Rate (HR) variations on the generic TF and on reconstructed CAP waveforms is investigated. The HR variation analysis is provided on a single patient data to exclude inter-patient influences at the current research stage. A new approach for the generic TF estimating from a data ensemble is presented as well. Moreover, an influence of the cardiac period beginning point selection is analyzed and empirically optimal solution for its selection is proposed. PMID:26736870

  17. [Value of prostate-specific antigen measurements with newly developed enzyme immunoassay (MARKIT-M PA)].

    PubMed

    Arai, Y; Onishi, H; Oishi, K; Takeuchi, H; Yoshida, O

    1992-10-01

    Serum prostate-specific antigen (PSA) levels in patients with prostate cancer and benign prostate hypertrophy (BPH) were investigated with a newly developed enzyme immunoassay (MARKIT-M PA, Dainippon Pharmaceutical Co. Ltd., Osaka, Japan). Sensitivity of the assay system is 0.5 ng/ml and the detection range is 0.5-100 ng/ml. There was a high linear correlation (r = 0.987) between the assay and MARKIT-F PA, and values obtained with the assay were almost equal to those yielded by MARKIT-F PA assay. Using the BPH group as a negative control, the upper cut-off value in BPH patients was determined to be 3.6 ng/ml. Of the 48 patients with untreated prostate cancer, 77% was detectable by means of MARKIT-M PA assay. Using the BPH group as a negative control, specificity and efficiency were 93% and 86%, respectively. In another group of 27 BPH patients whose blood samples were taken immediately after digital prostatic examination, PSA was elevated in 15%. During follow-up of prostate cancer patients, PSA was elevated in 82% at the time of clinically detectable progression. In 15 patients whose disease was clinically well controlled, all levels of PSA were observed to be negative. These findings suggests that detection of serum PSA with this assay is of great use both in the diagnosis and monitoring of prostate cancer patients. PMID:1282772

  18. Measurement of patient-derived utility values for periodontal health using a multi-attribute scale.

    PubMed

    Bellamy, C A; Brickley, M R; McAndrew, R

    1996-09-01

    Periodontal health states are difficult to quantify and no formal scale quantifying patients' utilities for periodontal health states exits. Multi-attribute utility (MAU) techniques were used to develop such a scale. The MAU scale may be used to quantify patients' assessment of their current periodontal health and that of possible treatment outcomes. Such data, combined with probability values in formal decision analysis techniques would result in improved rationality of treatment planning for periodontal disease. 20 patients attending for routine undergraduate care were interviewed. Data from these interviews were sorted into groups of common interest (domains). Intra-domain health statements were complied from the interview content. 21 patients ranked the intra-domain statements on a scale of 0-100. This same group of patients also performed an inter-domain weighting. Mean results showed that patients were 2X as concerned with how they felt and with the prognosis of possible outcomes, than with how they looked and what facts they knew about their oral health. However, the real value of utilities research lies in application of individual results to treatment planning as there is a wide range of opinion regarding outcome health states. PMID:8891929

  19. Evaluation of Oxygen Radical Absorbance Capacity in Kampo Medicine

    PubMed Central

    Nishimura, Ko; Osawa, Toshihiko; Watanabe, Kenji

    2011-01-01

    Antioxidant capacity of food has come to be shown in terms of oxygen radical absorbance capacity (ORAC) mainly on vegetables or fruit. However, the evaluation of Kampo in terms of ORAC has not yet been accomplished. It is important that such an investigation is also conducted for Kampo medicine. We measured the ORAC value of almost all the available Kampo formulas used in the Japanese National health insurance system and examined the ORAC value both for the daily prescription, and also the crude herb ingredients. The ORAC value of Kampo medicine ranged 4.65–5913 units/day. The ORAC value was high in Kampo formulas including Rhei Rhizoma, and was relatively high in Kampo formulas including anti-inflammatory herbs other than Rhei Rhizoma. The ORAC value was also high in Kampo formulas including crude herbs that have relaxation effects. The ORAC value of a crude herb would seem to not be fixed but be dependent on combination with other crude herbs from the comparison of different herbs added to the basic Kampo medicine. These results suggest variability and complexity of the antioxidant capacity of Kampo medicine within the similar range of food. On the other hand, investigation of the compound changes of various crude herbs with ORAC may lead to the elucidation of the action mechanism of Kampo medicine. PMID:19126557

  20. [Differences in Measured Values among Homogenous Assay Reagents of LDL-C in LP-X Positive Serum Samples].

    PubMed

    Abe, Misako; Kurosawa, Hideo; Sato, Ryo; Ito, Kumie; Tomono, Yoshiharu; Manita, Daisuke; Hirowatari, Yuji; Yoshida, Hiroshi

    2015-03-01

    The LDL-C level measures with homogeneous (direct) assays in almost of clinical laboratories. Several reports however showed differences in measured values among the assay reagents. We investigated the differences in LDL-C values among direct assays and Friedewald formula (F-f) in 58 LP-X positive serum samples from jaundice patients by comparing LDL-C values measured by anion-exchange chromatography (AEX-HPLC), largely comparable to ultracentrifugation method. Changes in LDL-C values during the treatment of 8 patients were also investigated. Direct assay reagents from Sekisui Medical (S-r), Denka-Seiken (D-r), Wako Chemical (W-r), and Kyowa Medics (K-r) were used for comparison. F-f, S-r, and D-r correlated with AEX-HPLC with r values < 0.6 while W-r and K-r correlated with AEX-HPLC with r-vales > 0.6. Two samples in which F-f values provided 500 mg/dL plus bias to AEX-HPLC (LDL-C value of 220 mg/dL) demonstrated increased levels of IDL-C before treatment. LDL-C values (S-r and D-r) of the 2 samples were relatively high and near to F-f data while LDL-C values (W-r and K-r) were relatively low and close to AEX-HPLC data. The jaundice treatment decreased LDL-C values (S-r and D-r) and converged to 220 mg/dL, indicating that S-r and D-r might react markedly to IDL. These changes were consistent with decreases in serum free cholesterol and phospholipid in support of LP-X. By contrast, W-r and K-r data showed upward tendency and also converged to 220 mg/dL. These results suggest that LDL-C direct assay reagents would be classified into 2 groups with respect to the reagent reactivity to LP-X. PMID:26524853

  1. Nuclear space-valued stochastic differential equations driven by Poisson random measures

    SciTech Connect

    Xiong, J.

    1992-01-01

    The thesis is devoted primarily to the study of stochastic differential equations on duals of nuclear spaces driven by Poisson random measures. The existence of a weak solution is obtained by the Galerkin method and the uniqueness is established by implementing the Yamada-Watanabe argument in the present setup. When the magnitudes of the driving terms are small enough and the Poisson streams occur frequently enough, it is proved that the stochastic differential equations mentioned above can be approximated by diffusion equations. Finally, the author considers a system of interacting stochastic differential equations driven by Poisson random measures. Let (X[sup n][sub i](t), [center dot][center dot][center dot], X[sup n][sub n](t)) be the solution of this system and consider the empirical measures [zeta]n([omega],B) [identical to] (1/n) (sum of j=1 to n) [delta]x[sup n][sub j]([center dot],[omega])(B) (n[>=]1). It is provided that [zeta][sub n] converges in distribution to a non-random measure which is the unique solution of a McKean-Vlasov equation. The above problems are motivated by applications to neurophysiology, in particular, to the fluctuation of voltage potentials of spatially distributed neurons and to the study of asymptotic behavior of large systems of interacting neurons.

  2. The Meaningful Activity Participation Assessment: A Measure of Engagement in Personally Valued Activities

    ERIC Educational Resources Information Center

    Eakman, Aaron M.; Carlson, Mike E.; Clark, Florence A.

    2010-01-01

    The Meaningful Activity Participation Assessment (MAPA), a recently developed 28-item tool designed to measure the meaningfulness of activity, was tested in a sample of 154 older adults. The MAPA evidenced a sufficient level of internal consistency and test-retest reliability and correlated as theoretically predicted with the Life Satisfaction…

  3. Predictive Values of Selected Auditory Perceptual Factors in Relation to Measured First Grade Reading Achievement.

    ERIC Educational Resources Information Center

    McNinch, George

    A study was conducted to determine the relationship between auditory perceptual skills and first-grade reading success when readiness and intelligence measures were used in conjunction with auditory skills assessments. Sex differences were also considered. Six boys and six girls were randomly selected from each of 10 first-grade classrooms.…

  4. Measuring Our Success: How to Gauge the "Value Added" by an Independent School Education

    ERIC Educational Resources Information Center

    Gulla, John; Jorgenson, Olaf

    2014-01-01

    Having addressed variations of the question--How can a school's success be "measured"?--with mixed results across a collective five decades of service to boards, John Gulla and Olaf Jorgenson endeavored to develop a more helpful answer. To this end, they queried 200-plus leaders of California Association of Independent Schools…

  5. Measuring School and Teacher Value Added for IMPACT and TEAM in DC Public Schools. Final Report

    ERIC Educational Resources Information Center

    Isenberg, Eric; Hock, Heinrich

    2010-01-01

    The District of Columbia Public Schools (DCPS) has incorporated measures of school and teacher effectiveness, based on student test score growth, into a new teacher assessment system known as IMPACT. Implemented for the first time during the 2009-2010 school year, IMPACT is an assessment system with significant consequences. Prior to the start of…

  6. Absorbed Dose Determination Using Experimental and Analytical Predictions of X-Ray Spectra

    NASA Technical Reports Server (NTRS)

    Edwards, D. L.; Carruth, Ralph (Technical Monitor)

    2001-01-01

    Electron beam welding in a vacuum is a technology that NASA is investigating as a joining technique for manufacture of space structures. This investigation characterizes the x-ray environment due to operation of an in-vacuum electron beam welding tool and provides recommendations for adequate shielding for astronauts performing the in-vacuum electron beam welding. NASA, in a joint venture with the Russian Space Agency, was scheduled to perform a series of welding in space experiments on board the U.S. Space Shuttle. This series of experiments was named the international space welding experiment (ISWE). The hardware associated with the ISWE was leased to NASA by the Paton Welding Institute (PWI) in Ukraine for ground-based welding experiments in preparation for flight. Two ground tests were scheduled, using the ISWE electron beam welding tool, to characterize the radiation exposure to an astronaut during the operation of the ISWE. These radiation exposure tests used thermoluminescence dosimeters (TLD's) shielded with material currently used by astronauts during extravehicular activities to measure the radiation dose. The TLD's were exposed to x-ray radiation generated by operation of the ISWE in-vacuum electron beam welding tool. This investigation was the first known application of TLD's to measure absorbed dose from x rays of energy less than 10 keV. The ISWE hardware was returned to Ukraine before the issue of adequate shielding for the astronauts was completely verified. Therefore, alternate experimental and analytical methods were developed to measure and predict the x-ray spectral and intensity distribution generated by ISWE electron beam impact with metal. These x-ray spectra were normalized to an equivalent ISWE exposure, then used to calculate the absorbed radiation dose to astronauts. These absorbed dose values were compared to TLD measurements obtained during actual operation of the ISWE in-vacuum electron beam welding tool. The calculated absorbed dose

  7. Improved estimates of the radiation absorbed dose to the urinary bladder wall

    NASA Astrophysics Data System (ADS)

    Andersson, Martin; Minarik, David; Johansson, Lennart; Mattsson, Sören; Leide-Svegborn, Sigrid

    2014-05-01

    Specific absorbed fractions (SAFs) have been calculated as a function of the content in the urinary bladder in order to allow more realistic calculations of the absorbed dose to the bladder wall. The SAFs were calculated using the urinary bladder anatomy from the ICRP male and female adult reference computational phantoms. The urinary bladder and its content were approximated by a sphere with a wall of constant mass, where the thickness of the wall depended on the amount of urine in the bladder. SAFs were calculated for males and females with 17 different urinary bladder volumes from 10 to 800 mL, using the Monte Carlo computer program MCNP5, at 25 energies of mono-energetic photons and electrons ranging from 10 KeV to 10 MeV. The decay was assumed to be homogeneously distributed in the urinary bladder content and the urinary bladder wall, and the mean absorbed dose to the urinary bladder wall was calculated. The Monte Carlo simulations were validated against measurements made with thermoluminescent dosimeters. The SAFs obtained for a urine volume of 200 mL were compared to the values calculated for the urinary bladder wall using the adult reference computational phantoms. The mean absorbed dose to the urinary wall from 18F-FDG was found to be 77 µGy/MBq formales and 86 µGy/MBq for females, while for 99mTc-DTPA the mean absorbed doses were 80 µGy/MBq for males and 86 µGy/MBq for females. Compared to calculations using a constant value of the SAF from the adult reference computational phantoms, the mean absorbed doses to the bladder wall were 60% higher for 18F-FDG and 30% higher for 99mTc-DTPA using the new SAFs.

  8. [QUALITY MEASURES IN MEDICINE-- A PLEA FOR NEW, VALUE BASED THINKING].

    PubMed

    Fisher, Menachem; Wagner, Oded; Keinarl, Talia; Solt, Ido

    2015-09-01

    Quality is an important and basic conduct of complex systems in general and health systems in particular. Quality is a cornerstone of medicine, necessary in the eyes of the community of consumers, caregivers, and the systems that manage both. In Israel, the Ministry of Health has set the quality issue on the agenda of healthcare organizations in all existing frameworks. In this article we seek to offer an acceptable alternative perspective, in examining the quality of public health. We suggest highlighting the ethical aspect of medical care, while reducing the quantitative monitoring component of existing quality metrics. Relying solely on indices has negative effects that might cause damage. The proposed alternative focuses on the personal responsibility of health care providers, using. values and moral reasonin. PMID:26665750

  9. Measurement of local values of strains of the briquette by means of special resistance strain gauges

    NASA Astrophysics Data System (ADS)

    Rysz, Jozef

    1997-02-01

    Local measurement of the coal briquette strains during its destruction caused by sudden decrease of pressure of gas filling pores is difficult, because of high strain of coal (exceeds 16%), which results in bursting. A special type of an resistance-strain gauge, which is pressed into a defined position during briquette preparation was elaborated. This gauge is deformed just as the surrounding coal. The strain is measured as a difference in resistance of a mixture of coal grains (briquette material) and short, 8 micrometers dia. graphite fibers. A ca. 0.5 mm thick and ca. 1 mm long gauge was prepared. Its initial resistance constituted several hundreds ohms. The resistance vs. strain dependence is not linear but stable enough in time and does not depend on the type of gas filling briquette pores (e.g. CO2 and He).

  10. Assessing pain intensity following spinal cord injury: should rating scales measure 'overall' or 'maximal' values?

    PubMed

    Frank, Andrew O; Spyridonis, Fotios; Ghinea, Gheorghita

    2015-03-01

    Rating scales (RSs) are important for the assessment of pain intensity (PI) following a spinal cord injury (SCI). Using a Graphic Rating Scale, this pilot study measured an 'overall' level of PI repeated about every 2 h over 1 day and compared it with maximal PI scores reported previously. Patients were categorized into severity groups according to the overall Graphic Rating Scale score at initial assessment (T0). Eight men and six women (mean age 53.1; range 28-75) participated. Comparison of the overall PI scores and their changes over time with the maximal PI scores reported previously showed loss of patients in the severe group and less pronounced PI changes over time. Rating scales used in spinal cord injury services should measure maximal pain experienced 'right now' to eliminate potential averaging out of pain over time, which might allow physicians to assist patients in understanding their pain and begin their adjustment. PMID:25419691

  11. [Fiberoptic measurement of myocardial contraction--correlation of the signal with hemodynamic values].

    PubMed

    Müller, S; Kloppe, A; Mügge, A; Werner, J

    2002-01-01

    In addition to the intracardial ECG, the mechanical myocard contraction should be used as another input signal for cardiac pacemakers and implantable defibrillators. Therefore a fiberoptical measurement system was designed. A sensor-fiber was placed in the coronary venous system. An opto-electronic system converts the optical losses, caused by bending of the fiber, into a proportional voltage. This method allows measuring of the left ventricular myocard contraction strength. By theoretical calculations it was shown, that a good correlation of the sensor-signal and the left ventricular radius can be expected. Additional investigations using an isolated beating pig heart were performed. A high correlation of the sensor-signal and the left ventricular stroke volume was shown. PMID:12465226

  12. The right tool for the right job: the value of alternative patient experience measures.

    PubMed

    Ho, Lynn; Swartz, Adam; Wasson, John H

    2013-01-01

    Patient-reported experience of care predicts health care outcomes. Fourteen US and Canadian practices intercalated a standard ambulatory care Consumer Assessment of Healthcare Providers and Systems (CAHPS) survey within their usual Internet-based survey to compare results from the Internet survey, Internet CAHPS survey, and a mailed CAHPS survey. They found that practice performance rankings obtained via the multi-item CAHPS survey were equivalent to a single measure captured by the Internet survey. PMID:23748272

  13. Operational Risk Measurement of Chinese Commercial Banks Based on Extreme Value Theory

    NASA Astrophysics Data System (ADS)

    Song, Jiashan; Li, Yong; Ji, Feng; Peng, Cheng

    The financial institutions and supervision institutions have all agreed on strengthening the measurement and management of operational risks. This paper attempts to build a model on the loss of operational risks basing on Peak Over Threshold model, emphasizing on weighted least square, which improved Hill’s estimation method, while discussing the situation of small sample, and fix the sample threshold more objectively basing on the media-published data of primary banks loss on operational risk from 1994 to 2007.

  14. Hospital value-based purchasing (VBP) program: measurement of quality and enforcement of quality improvement.

    PubMed

    Szablowski, Katarzyna M

    2014-01-01

    VBP program is a novel medicare payment estimatin tool used to encourage clinical care quality improvement as well as improvement of patient experience as a customer of a health care system. The program utilizes well established tools of measuring clinical care quality and patient satisfaction such as the hospital IQR program and HCAHPS survey to estimate Medicare payments and encourage hospitals to continuosly improve the level of care they provide. PMID:24600783

  15. Absorbent product to absorb fluids. [for collection of human wastes

    NASA Technical Reports Server (NTRS)

    Dawn, F. S.; Correale, J. V. (Inventor)

    1982-01-01

    A multi-layer absorbent product for use in contact with the skin to absorb fluids is discussed. The product utilizes a water pervious facing layer for contacting the skin, overlayed by a first fibrous wicking layer, the wicking layer preferably being of the one-way variety in which fluid or liquid is moved away from the facing layer. The product further includes a first container section defined by inner and outer layer of a water pervious wicking material between which is disposed a first absorbent mass. A second container section defined by inner and outer layers between which is disposed a second absorbent mass and a liquid impermeable/gas permeable layer. Spacesuit applications are discussed.

  16. Calculation of RABBIT and Simulator Worth in the HFIR Hydraulic Tube and Comparison with Measured Values

    SciTech Connect

    Slater, CO

    2005-09-08

    To aid in the determinations of reactivity worths for target materials in a proposed High Flux Isotope Reactor (HFIR) target configuration containing two additional hydraulic tubes, the worths of cadmium rabbits within the current hydraulic tube were calculated using a reference model of the HFIR and the MCNP5 computer code. The worths were compared to measured worths for both static and ejection experiments. After accounting for uncertainties in the calculations and the measurements, excellent agreement between the two was obtained. Computational and measurement limitations indicate that accurate estimation of worth is only possible when the worth exceeds 10 cents. Results indicate that MCNP5 and the reactor model can be used to predict reactivity worths of various samples when the expected perturbations are greater than 10 cents. The level of agreement between calculation and experiment indicates that the accuracy of such predictions would be dependent solely on the quality of the nuclear data for the materials to be irradiated. Transients that are approximated by ''piecewise static'' computational models should likewise have an accuracy that is dependent solely on the quality of the nuclear data.

  17. The Value of Automated Follicle Volume Measurements in IVF/ICSI

    PubMed Central

    Vandekerckhove, Frank; Bracke, Victoria; De Sutter, Petra

    2014-01-01

    Background/Aims: The objective of this literature study is to investigate the place of recent software technology sonography-based automated volume count (SonoAVC) for the automatic measurement of follicular volumes in IVF/ICSI. Its advantages and disadvantages and potential future developments are evaluated. Methods: A total of 74 articles were read via a PubMed literature study. The literature study included 53 articles, 32 of which for the systematic review. Results: The SonoAVC software shows excellent accuracy. Comparing the technology with the “golden standard” two-dimensional (2D) manual follicle measurements, SonoAVC leads to a significantly lower intra- and inter-observer variability. However, there is no significant difference in clinical outcome (pregnancy rate). We noted a significant advantage in the time gained, both for doctor and patient. By storing the images, the technology offers the possibility of including a quality control and continuous training and further standardization of follicular monitoring can be expected. Ovarian reserve testing by measuring the antral follicle count with SonoAVC is highly reliable. Conclusion: This overview of previously published literature shows how SonoAVC offers advantages for clinical practice, without losing any accuracy or reliability. Doctors should be motivated to the general use of follicular volumes instead of follicular diameters. PMID:25593942

  18. Diagnostic Value of Measuring Platelet Von Willebrand Factor in Von Willebrand Disease

    PubMed Central

    Casonato, Alessandra; Cattini, Maria Grazia; Daidone, Viviana; Pontara, Elena; Bertomoro, Antonella; Prandoni, Paolo

    2016-01-01

    Von Willebrand disease (VWD) may be caused by an impaired von Willebrand factor (VWF) synthesis, its increased clearance or abnormal function, or combinations of these factors. It may be difficult to recognize the different contributions of these anomalies. Here we demonstrate that VWD diagnostics gains from measuring platelet VWF, which can reveal a defective VWF synthesis. Measuring platelet VWF revealed that: severe type 1 VWD always coincided with significantly lower platelet and plasma VWF levels, whereas mild forms revealed low plasma VWF levels associated with low or normal platelet VWF levels, and the latter were associated with a slightly shorter VWF survival; type Vicenza (the archetype VWD caused by a reduced VWF survival) featured normal platelet VWF levels despite significantly reduced plasma VWF levels; type 2B patients could have either normal platelet VWF levels associated with abnormal multimer patterns, or reduced platelet VWF levels associated with normal multimer patterns; type 2A patients could have reduced or normal platelet VWF levels, the former associated mainly with type 2A-I, the latter with type 2A-II; plasma and platelet VWF levels were normal in type 2N, except when the defect was associated with a quantitative VWF mutation. Our findings show that measuring platelet VWF helps to characterize VWD, especially the ambiguous phenotypes, shedding light on the mechanisms underlying the disorder. PMID:27532107

  19. In-vivo measurement of intrauterine gases and acid-base values early in human pregnancy.

    PubMed

    Jauniaux, E; Watson, A; Ozturk, O; Quick, D; Burton, G

    1999-11-01

    A new multiparameter sensor that combines electrochemical and fibre-optic technology was used for continuous in-vivo investigation of pH, carbon dioxide partial pressure (PCO(2)), oxygen partial pressure (PO(2)), bicarbonate concentration (HCO(3)(-)), base excess, and oxygen saturation (O(2)Sat) early in human pregnancy. The sensor was inserted into the amniotic cavity and the placental bed of 16 pregnancies at 10-15 weeks gestation, before termination under general anaesthesia. Amniotic fluid and retroplacental blood from the same site were also aspirated and analysed by means of cartridges and a portable blood gas analyser. Eleven series of measurements were obtained. The variation in measurements over the 5 min of monitoring was Measurements of PO(2) in both the amniotic cavity and the placental bed and of pH in the placental bed were higher using the cartridges than in vivo. The results indicated that in-vivo monitoring of fetoplacental gas and acid-base with a sensor is stable and accurate. Such technology will be helpful in improving our understanding of the fetoplacental metabolism in normal and complicated pregnancies. PMID:10548645

  20. Preparation of nanosize polyaniline and its utilization for microwave absorber.

    PubMed

    Abbas, S M; Dixit, A K; Chatterjee, R; Goel, T C

    2007-06-01

    Polyaniline powder in nanosize has been synthesized by chemical oxidative route. XRD, FTIR, and TEM were used to characterize the polyaniline powder. Crytallite size was estimated from XRD profile and also ascertained by TEM in the range of 15 to 20 nm. The composite absorbers have been prepared by mixing different ratios of polyaniline into procured polyurethane (PU) binder. The complex permittivity (epsilon' - jepsilon") and complex permeability (mu' - jmu") were measured in X-band (8.2-12.4 GHz) using Agilent network analyzer (model PNA E8364B) and its software module 85071 (version 'E'). Measured values of these parameters were used to determine the reflection loss at different frequencies and sample thicknesses, based on a model of a single layered plane wave absorber backed by a perfect conductor. An optimized polyaniline/PU ratio of 3:1 has given a minimum reflection loss of -30 dB (99.9% power absorption) at the central frequency 10 GHz and the bandwidth (full width at half minimum) of 4.2 GHz over whole X-band (8.2 to 12.4 GHz) in a sample thickness of 3.0 mm. The prepared composites can be fruitfully utilized for suppression of electromagnetic interference (EMI) and reduction of radar signatures (stealth technology). PMID:17655005