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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

    DOEpatents

    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. Reflection measurements of microwave absorbers

    NASA Astrophysics Data System (ADS)

    Baker, Dirk E.; van der Neut, Cornelis A.

    1988-12-01

    A swept-frequency interferometer is described for making rapid, real-time assessments of localized inhomogeneities in planar microwave absorber panels. An aperture-matched exponential horn is used to reduce residual reflections in the system to about -37 dB. This residual reflection is adequate for making comparative measurements on planar absorber panels whose reflectivities usually fall in the -15 to -25 dB range. Reflectivity measurements on a variety of planar absorber panels show that multilayer Jaumann absorbers have the greatest inhomogeneity, while honeycomb absorbers generally have excellent homogeneity within a sheet and from sheet to sheet. The test setup is also used to measure the center frequencies of resonant absorbers. With directional couplers and aperture-matched exponential horns, the technique can be easily applied in the standard 2 to 40 GHz waveguide bands.

  4. 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.

  5. Long term measurements of light absorbing particles on tropical glaciers

    NASA Astrophysics Data System (ADS)

    Schmitt, C. G.; Sanchez Rodriguez, W.; Arnott, W. P.; All, J.; Schwarz, J. P.

    2016-12-01

    We present results of six years of measurements of light absorbing particles (LAP) on glaciers of the Cordillera Blanca mountain range in Peru. Tropical glaciers are important sources of water for human consumption, agriculture, and hydroelectric power in the region. Regular measurements in the dry season show that light absorbing particle concentrations are generally low (equivalent to the absorption equivalent of 5-30 nanograms of black carbon per gram of snow) during non-El Nino years while values increase substantially during the recent El Nino. Two years of monthly measurements at two glaciers show that fresh snow LAP concentration are very low while LAP levels increase dramatically during snow-less periods.

  6. Acoustic absorbance measurements in neonates exposed to smoking during pregnancy.

    PubMed

    Pucci, Beatriz Paloma Corrêa; Roque, Nayara Michelle Costa de Freitas; Gamero, Marcella Scigliano; Durante, Alessandra Spada

    2017-04-01

    To analyze acoustic absorbance using wideband tympanometry in neonates exposed to passive smoking during pregnancy. A study comprising 54 neonates in the control group (CG - unexposed) and 19 in the study group (SG - exposed) was carried out. Subjects were submitted to the wideband tympanometry test and subsequent analysis of absorbance of 17 frequencies. Low frequencies had a lower level of absorbance compared to high frequencies for both ambient and peak pressures, with no difference between the groups. No effect of passive smoking on acoustic absorbance measurements in neonates was observed. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. 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.

  8. Design and measuring of a tunable hybrid metamaterial absorber for terahertz frequencies

    NASA Astrophysics Data System (ADS)

    Zhong, Min; Liu, Shui Jie; Xu, Bang Li; Wang, Jie; Huang, Hua Qing

    2018-04-01

    A tunable hybrid metamaterial absorber is designed and experimentally produced in THz band. The hybrid metamaterial absorber contains two dielectric layers: SU-8 and VO2 layers. An absorption peak reaching to 83.5% is achieved at 1.04 THz. The hybrid metamaterial absorber exhibits high absorption when the incident angle reaches to 45°. Measured results indicate that the absorption amplitude and peak frequency of the hybrid metamaterial absorber is tunable in experiments. It is due to the insulator-to-metal phase transition is achieved when the measured temperature reaches to 68 °C. Moreover, the hybrid metamaterial absorber reveals high figure of merit (FOM) value when the measured temperature reaches to 68 °C.

  9. Selective solar absorber emittance measurement at elevated temperature

    NASA Astrophysics Data System (ADS)

    Giraud, Philémon; Braillon, Julien; Raccurt, Olivier

    2017-06-01

    Durability of solar components for CSP (Concentrated Solar Power Plant) technologies is a key point to lower cost and ensure their large deployment. These technologies concentrated the solar radiation by means of mirrors on a receiver tube where it is collected as thermal energy. The absorbers are submitted to strong environmental constraints and the degradation of their optical properties (emittance and solar absorbance) have a direct impact on performance. The characterization of a material in such condition is complicated and requires advanced apparatuses, and different measurement methods exist for the determination of the two quantities of relevance regarding an absorber, which are its emittance and its solar absorbance. The objective is to develop new optical equipment for measure the emittance of this solar absorber at elevated temperature. In this paper, we present an optical bench developed for emittance measurement on absorbers is conditions of use. Results will be shown, with a discussion of some factors of influence over this measurement and how to control them.

  10. Antioxidative activity of lactobacilli measured by oxygen radical absorbance capacity.

    PubMed

    Saide, J A O; Gilliland, S E

    2005-04-01

    The reducing ability and antioxidative activity of some species of Lactobacillus were compared under in vitro conditions. Cultures of Lactobacillus delbrueckii ssp. lactis, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and Lactobacillus casei were grown at 37 degrees C in de Man, Rogosa, Sharpe (MRS) broth supplemented with 0.5% 2,3,5 triphenyl tetrazolium chloride (TTC) to evaluate reducing activity. Reduced TTC was extracted from the cultures with acetone, and the intensity of the red color measured colorimetrically at 485 nm was an indication of reducing activity. The lactobacilli varied significantly in relative ability to reduce TTC when grown in MRS broth for 15 h. The relative amounts of growth as indicated by pH values at 18 h appeared to influence the amount of reduction. Antioxidative activity was evaluated by the ability of the whole cells or the cell-free extracts from cultures to protect a protein from being attacked by free radicals. These analyses were performed using the oxygen radical absorbance capacity method. All cultures tested exhibited some degree of antioxidative activity. Among the treatments, the cell-free extracts from cells grown in MRS broth exhibited significantly higher values than did whole cells. There was no apparent relationship between the reducing and antioxidative activities of the cultures evaluated. The results from this study show that these cultures can provide a source of dietary antioxidants. Furthermore, selection of cultures that produce antioxidants as starters could provide yet another health or nutritional benefit from cultured or culture-containing dairy products.

  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. 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.

  13. Breathing gas perfluorocarbon measurements using an absorber filled with zeolites.

    PubMed

    Proquitté, H; Rüdiger, M; Wauer, R R; Schmalisch, G

    2003-11-01

    Perfluorocarbon (PFC) has been widely used in the treatment of respiratory diseases; however, PFC content of the breathing gases remains unknown. Therefore, we developed an absorber using PFC selective zeolites for PFC measurement in gases and investigated its accuracy. To generate a breathing gas with different PFC contents a heated flask was rinsed with a constant air flow of 4 litre x min(-1) and 1, 5, 10, and 20 ml of PFC were infused over 20 min using an infusor. The absorber was placed on an electronic scale and the total PFC volume was calculated from the weight gain. Steady-state increase in weight was achieved 3.5 min after stopping the infusion. The calculated PFC volume was slightly underestimated but the measuring error did not exceed -1% for PFC less than 1 ml. The measurement error decreased with increasing PFC volume. This zeolite absorber is an accurate method to quantitatively determine PFC in breathing gases and can be used as a reference method to validate other PFC sensors.

  14. Strain Gage Measurements of Aft Nacelle Shock Absorbers.

    DTIC Science & Technology

    ENGINE NACELLES, SHOCK ABSORBERS ), (* SHOCK ABSORBERS , STRESSES), SURFACE TO SURFACE MISSILES, LAUNCHING, STRAIN GAGES, COMPRESSIVE PROPERTIES, CALIBRATION, STRAIN(MECHANICS), FAILURE, GROUND SUPPORT EQUIPMENT.

  15. Real part of refractive index measurement approach for absorbing liquid.

    PubMed

    Liu, Hao; Ye, Junwei; Yang, Kecheng; Xia, Min; Guo, Wenping; Li, Wei

    2015-07-01

    An algorithm based on use of a reflected refractometer to measure the real part of the refractive index (RI) for an absorbing liquid is presented. The absorption of liquid will blur the division between bright and dark regions on a Fresnel reflective curve. However, the reflective ratio at some incident angles that are less than the critical angle have little sensitivity to absorbability. Unlike common methods that extract RI from reflectivity in critical angle vicinity, the presented method acquires the real RI from reflective ratio at a subcritical angle. Supported by the theoretical analysis and experimental results on a reflected refractometer, we have achieved accuracy better than 3×10(-4) RIU on ink samples with absorption coefficient around 300  cm(-1). Additional tests on Alizarin yellow GG solutions prove that the subcritical algorithm is feasible and of high accuracy.

  16. Measured acoustic properties of variable and low density bulk absorbers

    NASA Technical Reports Server (NTRS)

    Dahl, M. D.; Rice, E. J.

    1985-01-01

    Experimental data were taken to determine the acoustic absorbing properties of uniform low density and layered variable density samples using a bulk absober with a perforated plate facing to hold the material in place. In the layered variable density case, the bulk absorber was packed such that the lowest density layer began at the surface of the sample and progressed to higher density layers deeper inside. The samples were placed in a rectangular duct and measurements were taken using the two microphone method. The data were used to calculate specific acoustic impedances and normal incidence absorption coefficients. Results showed that for uniform density samples the absorption coefficient at low frequencies decreased with increasing density and resonances occurred in the absorption coefficient curve at lower densities. These results were confirmed by a model for uniform density bulk absorbers. Results from layered variable density samples showed that low frequency absorption was the highest when the lowest density possible was packed in the first layer near the exposed surface. The layers of increasing density within the sample had the effect of damping the resonances.

  17. Computed a multiple band metamaterial absorber and its application based on the figure of merit value

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Sheng, Yuping; Jun, Wang

    2018-01-01

    A high performed multiple band metamaterial absorber is designed and computed through the software Ansofts HFSS 10.0, which is constituted with two kinds of separated metal particles sub-structures. The multiple band absorption property of the metamaterial absorber is based on the resonance of localized surface plasmon (LSP) modes excited near edges of metal particles. The damping constant of gold layer is optimized to obtain a near-perfect absorption rate. Four kinds of dielectric layers is computed to achieve the perfect absorption perform. The perfect absorption perform of the metamaterial absorber is enhanced through optimizing the structural parameters (R = 75 nm, w = 80 nm). Moreover, a perfect absorption band is achieved because of the plasmonic hybridization phenomenon between LSP modes. The designed metamaterial absorber shows high sensitive in the changed of the refractive index of the liquid. A liquid refractive index sensor strategy is proposed based on the computed figure of merit (FOM) value of the metamaterial absorber. High FOM values (116, 111, and 108) are achieved with three liquid (Methanol, Carbon tetrachloride, and Carbon disulfide).

  18. Measurement of Absorbed Dose from Radionuclide Solutions Mixed Intimately with the Fbx Dosimeter.

    NASA Astrophysics Data System (ADS)

    Benedetto, Anthony Richard

    Chemical dosimeters are used widely for accurate measurement of large radiation doses due to external beam irradiation from radioisotope sources and from particle accelerators. Their use for measurement of absorbed doses from radioactive solutions mixed in the dosimeter solution was reported as early as 1952, but the large activities needed to produce suitable absorbance values in the relatively insensitive dosimeters of that time discouraged further work. This manuscript reports the results of an investigation into the suitability of the ferrous sulfate-benzoic acid -xylenol orange (FBX) dosimeter for measurement of small absorbed doses caused by radionuclide solutions dissolved in the dosimeter solution. The FBX dosimeter exhibited a linear dose response as a function of activity for two common radiopharmaceuticals, technetium-99m sodium pertechnetate and iodine-131 sodium iodide. Conditions under which the FBX dosimeter may be used with radionuclide solutions were studied and were found to be amenable to routine use by laboratories possessing relatively unsophisticated instrumentation. It appears likely that any radionuclide could be studied using this dosimeter. Finally, potential applications and future research work are suggested, including measurement of absorbed dose from radiopharmaceuticals using realistic human-like phantoms to assess the risk from clinical nuclear medicine studies.

  19. 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.

  20. 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.

  1. Impedance Measurement of a Gamma-Ray TES Calorimeter with a Bulk Sn Absorber

    SciTech Connect

    Akamatsu, H.; Ishisaki, Y.; Hoshino, A.

    2009-12-16

    We performed complex impedance measurements with a Ti/Au-based gamma-ray TES calorimeter with a bulk Sn absorber. Excellent energy resolution of 38.4{+-}0.9eV at 60 keV was observed. The impedance of the calorimeter can be well explained by a two-body thermal model. We investigated the behavior of the parameters of the calorimeter during the superconducting-to-normal transition. We confirmed that C and G{sub a} are in good agreement with the predicted values. We performed a noise analysis and found several excess noise components, as well as internal thermal fluctuation noise (ITFN) term due to the thermal conductance between the Sn absorber and themore » Ti/Au TES. Dominanting the noise is an excess noise having a similar frequency dependence to the phonon noise and the ITFN noise.« less

  2. 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.

  3. Measuring value sensitivity in medicine.

    PubMed

    Ineichen, Christian; Christen, Markus; Tanner, Carmen

    2017-01-28

    Value sensitivity - the ability to recognize value-related issues when they arise in practice - is an indispensable competence for medical practitioners to enter decision-making processes related to ethical questions. However, the psychological competence of value sensitivity is seldom an explicit subject in the training of medical professionals. In this contribution, we outline the traditional concept of moral sensitivity in medicine and its revised form conceptualized as value sensitivity and we propose an instrument that measures value sensitivity. We developed an instrument for assessing the sensitivity for three value groups (moral-related values, values related to the principles of biomedical ethics, strategy-related values) in a four step procedure: 1) value identification (n = 317); 2) value representation (n = 317); 3) vignette construction and quality evaluation (n = 37); and 4) instrument validation by comparing nursing professionals with hospital managers (n = 48). We find that nursing professionals recognize and ascribe importance to principle-related issues more than professionals from hospital management. The latter are more likely to recognize and ascribe importance to strategy-related issues. These hypothesis-driven results demonstrate the discriminatory power of our newly developed instrument, which makes it useful not only for health care professionals in practice but for students and people working in the clinical context as well.

  4. Relationship between the structures of flavonoids and oxygen radical absorbance capacity values: a quantum chemical analysis.

    PubMed

    Zhang, Di; Liu, Yixiang; Chu, Le; Wei, Ying; Wang, Dan; Cai, Shengbao; Zhou, Feng; Ji, Baoping

    2013-02-28

    Various radical-scavenging activities (RSA) assessment assays are based on discrete mechanisms and on using different radical sources. Few studies have analyzed the structural significance of flavonoids in their peroxyl radical activities in the oxygen radical absorbance capacity (ORAC) assay. In this study, the RSA of 13 flavonoids in two ORAC assays with different probes (fluorescein and pyrogallol red) were investigated. Neither O-H bond dissociation enthalpy nor ionization potential values of flavonoids correlated with ORAC values. The proton affinity (PA) and electron transfer enthalpy (ETE) values, which were obtained via the sequential proton-loss electron-transfer mechanism, were significantly associated with the ORAC(pyrogallol Red) and ORAC(fluorescein) assays, respectively. Thus, PA represented the kinetic aspect of RSA, whereas ETE reflected the RSA extent. The PA values and the most acidic sites of flavonoids were affected by intramolecular electronic interactions, H-bonding, 3-hydroxyl group in the C ring, and conjugation systems. The stability of the deprotonated flavonoid determined the ETE value. Apart from the PA and ETE values in the first oxidation step of flavonoids, the PA and ETE values in the second oxidation step also affected the ORAC values of flavonoids.

  5. 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.

  6. Response of Non-Linear Shock Absorbers-Boundary Value Problem Analysis

    NASA Astrophysics Data System (ADS)

    Rahman, M. A.; Ahmed, U.; Uddin, M. S.

    2013-08-01

    A nonlinear boundary value problem of two degrees-of-freedom (DOF) untuned vibration damper systems using nonlinear springs and dampers has been numerically studied. As far as untuned damper is concerned, sixteen different combinations of linear and nonlinear springs and dampers have been comprehensively analyzed taking into account transient terms. For different cases, a comparative study is made for response versus time for different spring and damper types at three important frequency ratios: one at r = 1, one at r > 1 and one at r <1. The response of the system is changed because of the spring and damper nonlinearities; the change is different for different cases. Accordingly, an initially stable absorber may become unstable with time and vice versa. The analysis also shows that higher nonlinearity terms make the system more unstable. Numerical simulation includes transient vibrations. Although problems are much more complicated compared to those for a tuned absorber, a comparison of the results generated by the present numerical scheme with the exact one shows quite a reasonable agreement

  7. Fine-resolution voxel S values for constructing absorbed dose distributions at variable voxel size.

    PubMed

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

    2010-10-01

    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. VSVs were generated in soft tissue with a fine spatial sampling using the Monte Carlo (MC) code MCNPX for particle emissions of 9 radionuclides: (18)F, (90)Y, (99m)Tc, (111)In, (123)I, (131)I, (177)Lu, (186)Re, and (201)Tl. 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 (90)Y and (131)I 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. For the sphere model study, the mean relative difference in the average absorbed dose was 0.20% ± 0.41% for (90)Y and -0.36% ± 0.51% for (131)I (n = 20). For the hepatic tumor, the difference in the average absorbed dose to tumor was 0.33% for (90)Y and -0.61% for (131)I and the difference in average absorbed dose to the liver was 0.25% for (90)Y and -1.35% for (131)I. 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. This new VSV

  8. Design and measure of a tunable double-band metamaterial absorber in the THz spectrum

    NASA Astrophysics Data System (ADS)

    Guiming, Han

    2018-04-01

    We demonstrate and measure a hybrid double-band tunable metamaterial absorber in the terahertz region. The measured metamaterial absorber contains of a hybrid dielectric layer structure: a SU-8 layer and a VO2 layer. Near perfect double-band absorption performances are achieved by optimizing the SU-8 layer thickness at room temperature 25 °C. Measured results show that the phase transition can be observed when the measured temperature reaches 68 °C. Further measured results indicate that the resonance frequency and absorption amplitude of the proposed metamaterial absorber are tunable through increasing the measured temperature, while structural parameters unchanged. The proposed hybrid metamaterial absorber shows many advantages, such as frequency agility, absorption amplitude tunable, and simple fabrication.

  9. Robust sensor for turbidity measurement from light scattering and absorbing liquids.

    PubMed

    Kontturi, Ville; Turunen, Petri; Uozumi, Jun; Peiponen, Kai-Erik

    2009-12-01

    Internationally standardized turbidity measurements for probing solid particles in liquid are problematic in the case of simultaneous light scattering and absorption. A method and a sensor to determine the turbidity in the presence of light absorption are presented. The developed sensor makes use of the total internal reflection of a laser beam at the liquid-prism interface, and the turbidity is assessed using the concept of laser speckle pattern. Using average filtering in speckle data analyzing the observed dynamic speckle pattern, which is due to light scattering from particles and the static speckle due to stray light of the sensor, can be separated from each other. Good correlation between the standard deviation of dynamic speckle and turbidity value for nonabsorbing and for absorbing liquids was observed. The sensor is suggested, for instance, for the measurement of ill-behaved as well as small-volume turbid liquids in both medicine and process industry.

  10. Measuring neuronal avalanches in disordered systems with absorbing states

    NASA Astrophysics Data System (ADS)

    Girardi-Schappo, M.; Tragtenberg, M. H. R.

    2018-04-01

    Power-law-shaped avalanche-size distributions are widely used to probe for critical behavior in many different systems, particularly in neural networks. The definition of avalanche is ambiguous. Usually, theoretical avalanches are defined as the activity between a stimulus and the relaxation to an inactive absorbing state. On the other hand, experimental neuronal avalanches are defined by the activity between consecutive silent states. We claim that the latter definition may be extended to some theoretical models to characterize their power-law avalanches and critical behavior. We study a system in which the separation of driving and relaxation time scales emerges from its structure. We apply both definitions of avalanche to our model. Both yield power-law-distributed avalanches that scale with system size in the critical point as expected. Nevertheless, we find restricted power-law-distributed avalanches outside of the critical region within the experimental procedure, which is not expected by the standard theoretical definition. We remark that these results are dependent on the model details.

  11. Variability of measurements of sweat sodium using the regional absorbent-patch method.

    PubMed

    Dziedzic, Christine E; Ross, Megan L; Slater, Gary J; Burke, Louise M

    2014-09-01

    There is interest in including recommendations for the replacement of the sodium lost in sweat in individualized hydration plans for athletes. Although the regional absorbent-patch method provides a practical approach to measuring sweat sodium losses in field conditions, there is a need to understand the variability of estimates associated with this technique. Sweat samples were collected from the forearms, chest, scapula, and thigh of 12 cyclists during 2 standardized cycling time trials in the heat and 2 in temperate conditions. Single measure analysis of sodium concentration was conducted immediately by ion-selective electrodes (ISE). A subset of 30 samples was frozen for reanalysis of sodium concentration using ISE, flame photometry (FP), and conductivity (SC). Sweat samples collected in hot conditions produced higher sweat sodium concentrations than those from the temperate environment (P = .0032). A significant difference (P = .0048) in estimates of sweat sodium concentration was evident when calculated from the forearm average (mean ± 95% CL; 64 ± 12 mmol/L) compared with using a 4-site equation (70 ± 12 mmol/L). There was a high correlation between the values produced using different analytical techniques (r2 = .95), but mean values were different between treatments (frozen FP, frozen SC > immediate ISE > frozen ISE; P < .0001). Whole-body sweat sodium concentration estimates differed depending on the number of sites included in the calculation. Environmental testing conditions should be considered in the interpretation of results. The impact of sample freezing and subsequent analytical technique was small but statistically significant. Nevertheless, when undertaken using a standardized protocol, the regional absorbent-patch method appears to be a relatively robust field test.

  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. 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.

  14. 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.

  15. Refractive index measurements in absorbing media with white light spectral interferometry.

    PubMed

    Arosa, Yago; Lago, Elena López; de la Fuente, Raúl

    2018-03-19

    White light spectral interferometry is applied to measure the refractive index in absorbing liquids in the spectral range of 400-1000 nm. We analyze the influence of absorption on the visibility of interferometric fringes and, accordingly, on the measurement of the refractive index. Further, we show that the refractive index in the absorption band can be retrieved by a two-step process. The procedure requires the use of two samples of different thickness, the thicker one to retrieve the refractive index in the transparent region and the thinnest to obtain the data in the absorption region. First, the refractive index values are retrieved with good accuracy in the transparent region of the material for 1-mm-thick samples. Second, these refractive index values serve also to precisely calculate the thickness of a thinner sample (~150 µm) since the accuracy of the methods depends strongly on the thickness of the sample. Finally, the refractive index is recovered for the entire spectral range.

  16. Real-time measurement and monitoring of absorbed dose for electron beams

    NASA Astrophysics Data System (ADS)

    Korenev, Sergey; Korenev, Ivan; Rumega, Stanislav; Grossman, Leon

    2004-09-01

    The real-time method and system for measurement and monitoring of absorbed dose for industrial and research electron accelerators is considered in the report. The system was created on the basis of beam parameters method. The main concept of this method consists in the measurement of dissipated kinetic energy of electrons in the irradiated product, determination of number of electrons and mass of irradiated product in the same cell by following calculation of absorbed dose in the cell. The manual and automation systems for dose measurements are described. The systems are acceptable for all types of electron accelerators.

  17. 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.

  18. Most Wired 2006: measuring value.

    PubMed

    Solovy, Alden

    2006-07-01

    As the Most Wired hospitals incorporate information technology into their strategic plans, they combine a"balanced scorecard"approach with classic business analytics to measure how well IT delivers on their goals. To find out which organizations made this year's 100 Most Wired list, as well as those named in other survey categories, go to the foldout section.

  19. 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…

  20. MO-AB-BRA-03: Calorimetry-Based Absorbed Dose to Water Measurements Using Interferometry

    SciTech Connect

    Flores-Martinez, E; Malin, M; DeWerd, L

    2015-06-15

    Purpose: Interferometry-based calorimetry is a novel technique to measure radiation-induced temperature changes allowing the measurement of absorbed dose to water (ADW). There are no mechanical components in the field. This technique also has the possibility of obtaining 2D dose distributions. The goal of this investigation is to calorimetrically-measure doses between 2.5 and 5 Gy over a single projection in a photon beam using interferometry and compare the results with doses calculated using the TG-51 linac calibration. Methods: ADW was determined by measuring radiation-induced phase shifts (PSs) of light passing through water irradiated with a 6 MV photon beam. A 9×9×9more » cm{sup 3} glass phantom filled with water and placed in an arm of a Michelson interferometer was irradiated with 300, 400, 500 and 600 monitor units. The whole system was thermally insulated to achieve sufficient passive temperature control. The depth of measurement was 4.5 cm with a field size of 7×7 cm{sup 2}. The intensity of the fringe pattern was monitored with a photodiode and used to calculate the time-dependent PS curve. Data was acquired 60 s before and after the irradiation. The radiation-induced PS was calculated by taking the difference in the pre- and post-irradiation drifts extrapolated to the midpoint of the irradiation. Results were compared to computed doses. Results: Average comparison of calculated ADW values with interferometry-measured values showed an agreement to within 9.5%. k=1 uncertainties were 4.3% for calculations and 14.7% for measurements. The dominant source of uncertainty for the measurements was a temperature drift of about 30 µK/s caused by heat conduction from the interferometer’s surroundings. Conclusion: This work presented the first absolute ADW measurements using interferometry in the dose range of linac-based radiotherapy. Future work to improve measurements’ reproducibility includes the implementation of active thermal control techniques.« less

  1. A simple laser-based device for simultaneous microbial culture and absorbance measurement

    NASA Astrophysics Data System (ADS)

    Abrevaya, X. C.; Cortón, E.; Areso, O.; Mauas, P. J. D.

    2013-07-01

    In this work we present a device specifically designed to study microbial growth with several applications related to environmental microbiology and other areas of research as astrobiology. The Automated Measuring and Cultivation device (AMC-d) enables semi-continuous absorbance measurements directly during cultivation. It can measure simultaneously up to 16 samples. Growth curves using low and fast growing microorganism were plotted, including Escherichia coli and Haloferax volcanii, a halophilic archaeon.

  2. 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…

  3. Simultaneous measurement of liquid absorbance and refractive index using a compact optofluidic probe.

    PubMed

    Malak, Maurine; Marty, Frédéric; Bourouina, Tarik; Angelescu, Dan

    2013-07-21

    We present a novel optical technique for simultaneously measuring the absorbance and the refractive index of a thin film using an infrared optofluidic probe. Experiments were carried on two different liquids and the results agree with the bibliographical data. The ultimate goal is to achieve a multi-functional micro-optical device for analytical applications.

  4. Absorbed dose measurement in low temperature samples:. comparative methods using simulated material

    NASA Astrophysics Data System (ADS)

    Garcia, Ruth; Harris, Anthony; Winters, Martell; Howard, Betty; Mellor, Paul; Patil, Deepak; Meiner, Jason

    2004-09-01

    There is a growing need to reliably measure absorbed dose in low temperature samples, especially in the pharmaceutical and tissue banking industries. All dosimetry systems commonly used in the irradiation industry are temperature sensitive. Radiation of low temperature samples, such as those packaged with dry ice, must therefore take these dosimeter temperature effects into consideration. This paper will suggest a method to accurately deliver an absorbed radiation dose using dosimetry techniques designed to abrogate the skewing effects of low temperature environments on existing dosimetry systems.

  5. 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.

  6. Determination of the optimal cutoff value for a serological assay: an example using the Johne's Absorbed EIA.

    PubMed Central

    Ridge, S E; Vizard, A L

    1993-01-01

    Traditionally, in order to improve diagnostic accuracy, existing tests have been replaced with newly developed diagnostic tests with superior sensitivity and specificity. However, it is possible to improve existing tests by altering the cutoff value chosen to distinguish infected individuals from uninfected individuals. This paper uses data obtained from an investigation of the operating characteristics of the Johne's Absorbed EIA to demonstrate a method of determining a preferred cutoff value from several potentially useful cutoff settings. A method of determining the financial gain from using the preferred rather than the current cutoff value and a decision analysis method to assist in determining the optimal cutoff value when critical population parameters are not known with certainty are demonstrated. The results of this study indicate that the currently recommended cutoff value for the Johne's Absorbed EIA is only close to optimal when the disease prevalence is very low and false-positive test results are deemed to be very costly. In other situations, there were considerable financial advantages to using cutoff values calculated to maximize the benefit of testing. It is probable that the current cutoff values for other diagnostic tests may not be the most appropriate for every testing situation. This paper offers methods for identifying the cutoff value that maximizes the benefit of medical and veterinary diagnostic tests. PMID:8501227

  7. Measurement of absorbed dose during the phantom torso experiment on the International Space Station

    NASA Astrophysics Data System (ADS)

    Semones, E.; Gibbons, F.; Golightly, M.; Weyland, M.; Johnson, A.; Smith, G.; Shelfer, T.; Zapp, N.

    The Phantom Torso Experiment (PTE) was flown on the International Space Station (ISS) during Increment 2 (April-August 2001). The experiment was located in the US Lab module Human Research Facility (HRF) rack. The objective of the passive dosimetry portion of the experiment was to measure spatial distributions of absorbed dose in the 34, 1 inch sections of a modified RandoTM phantom. In each section of the phantom, thermoluminescent detectors (TLDs) were placed at various locations (depths) to provide the spatial measurement. TLDs were also located at several radiosensitive organ locations (brain, thyroid, heart/lung, stomach and colon) and two locations on the surface (skin). Active silicon detectors were also placed at these organ locations to provide time resolved results of the absorbed dose rates. Using these detectors, it is possible to separate the trapped and galactic cosmic ray components of the absorbed dose. The TLD results of the spatial and organ dose measurements will be presented and comparisons of the TLD and silicon detector organ absorbed doses will be made.

  8. Ultrahigh precision nonlinear reflectivity measurement system for saturable absorber mirrors with self-referenced fluence characterization.

    PubMed

    Orsila, Lasse; Härkönen, Antti; Hyyti, Janne; Guina, Mircea; Steinmeyer, Günter

    2014-08-01

    Measurement of nonlinear optical reflectivity of saturable absorber devices is discussed. A setup is described that enables absolute accuracy of reflectivity measurements better than 0.3%. A repeatability within 0.02% is shown for saturable absorbers with few-percent modulation depth. The setup incorporates an in situ knife-edge characterization of beam diameters, making absolute reflectivity estimations and determination of saturation fluences significantly more reliable. Additionally, several measures are discussed to substantially improve the reliability of the reflectivity measurements. At its core, the scheme exploits the limits of state-of-the-art digital lock-in technology but also greatly benefits from a fiber-based master-oscillator power-amplifier source, the use of an integrating sphere, and simultaneous comparison with a linear reflectivity standard.

  9. 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.

  10. Role of near ultraviolet wavelength measurements in the detection and retrieval of absorbing aerosols from space

    NASA Astrophysics Data System (ADS)

    Mukai, Sonoyo; Fujito, Toshiyuki; Nakata, Makiko; Sano, Itaru

    2017-10-01

    Aerosol remote sensing by ultraviolet (UV) wavelength is established by a Total Ozone Mapping Spectrometer (TOMS) mounted on the long-life satellite Nimbus-7 and continues to make observations using Ozone monitoring instrument (OMI) located on the Aura satellite. For example, TOMS demonstrated that UV radiation (0.331 and 0.360 μm) could easily detect absorbing particles such as mineral dust or smoke aerosols. TOMS-AI (absorbing aerosol index) has been used to identify the absorbing aerosols from space. For an upcoming mission, JAXA/GCOM-C will have the polarization sensor SGLI boarded in December 2017. The SGLI has multi (19)-channels including near UV (0.380 μm) and violet (0.412 μm) wavelengths. This work intends to examine the role of near UV data in the detection of absorbing aerosols similar to TOMS-AI played. In practice, the measurements by GLI mounted on the short Japanese mission JAXA/ADEOS-2, whose data archive period was just 8 months from April to October in 2003, are available for simulation of SGLI data because ADEOS-2/GLI installed near UV and violet channels. First of all, the ratio of data at 0.412 μm to that at 0.380 μm is examined as an indicator to detect absorbing aerosols on a global scale during ADEOS-2 era. It is noted that our research group has developed an efficient algorithm for aerosol retrieval in hazy episodes (dense concentrations of atmospheric aerosols). It can be said that at least this work is an attempt to grasp the biomass burning plumes from the satellite.

  11. Diamond detector in absorbed dose measurements in high‐energy linear accelerator photon and electron beams

    PubMed Central

    Binukumar, John Pichy; Amri, Iqbal Al; 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 1.1 mm, thickness 1×10−3mm, 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 stopping 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. PACS number(s): 87.56.Da PMID:27074452

  12. 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

    2016-03-08

    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.

  13. 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.

  14. Measurements of evaporated perfluorocarbon during partial liquid ventilation by a zeolite absorber.

    PubMed

    Proquitté, Hans; Rüdiger, Mario; Wauer, Roland R; Schmalisch, Gerd

    2004-01-01

    During partial liquid ventilation (PLV) the knowledge of the quantity of exhaled perfluorocarbon (PFC) allows a continuous substitution of the PFC loss to achieve a constant PFC level in the lungs. The aim of our in vitro study was to determine the PFC loss in the mixed expired gas by an absorber and to investigate the effect of the evaporated PFC on ventilatory measurements. To simulate the PFC loss during PLV, a heated flask was rinsed with a constant airflow of 4 L min(-1) and PFC was infused by different speeds (5, 10, 20 mL h(-1)). An absorber filled with PFC selective zeolites was connected with the flask to measure the PFC in the gas. The evaporated PFC volume and the PFC concentration were determined from the weight gain of the absorber measured by an electronic scale. The PFC-dependent volume error of the CO2SMO plus neonatal pneumotachograph was measured by manual movements of a syringe with volumes of 10 and 28 mL with a rate of 30 min(-1). Under steady state conditions there was a strong correlation (r2 = 0.999) between the infusion speed of PFC and the calculated PFC flow rate. The PFC flow rate was slightly underestimated by 4.3% (p < 0.01). However, this bias was independent from PFC infusion rate. The evaporated PFC volume was precisely measured with errors < 1%. The volume error of the CO2SMO-Plus pneumotachograph increased with increasing PFC content for both tidal volumes (p < 0.01). However for PFC flow rates up to 20 mL/h the error of the measured tidal volumes was < 5%. PFC selective zeolites can be used to quantify accurately the evaporated PFC volume during PLV. With increasing PFC concentrations in the exhaled air the measurement errors of ventilatory parameters have to be taken into account.

  15. 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.

  16. 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.

  17. 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.

  18. Reducing uncertainties associated with filter-based optical measurements of light absorbing carbon particles with chemical information

    NASA Astrophysics Data System (ADS)

    Engström, J. E.; Leck, C.

    2011-08-01

    The presented filter-based optical method for determination of soot (light absorbing carbon or Black Carbon, BC) can be implemented in the field under primitive conditions and at low cost. This enables researchers with small economical means to perform monitoring at remote locations, especially in the Asia where it is much needed. One concern when applying filter-based optical measurements of BC is that they suffer from systematic errors due to the light scattering of non-absorbing particles co-deposited on the filter, such as inorganic salts and mineral dust. In addition to an optical correction of the non-absorbing material this study provides a protocol for correction of light scattering based on the chemical quantification of the material, which is a novelty. A newly designed photometer was implemented to measure light transmission on particle accumulating filters, which includes an additional sensor recording backscattered light. The choice of polycarbonate membrane filters avoided high chemical blank values and reduced errors associated with length of the light path through the filter. Two protocols for corrections were applied to aerosol samples collected at the Maldives Climate Observatory Hanimaadhoo during episodes with either continentally influenced air from the Indian/Arabian subcontinents (winter season) or pristine air from the Southern Indian Ocean (summer monsoon). The two ways of correction (optical and chemical) lowered the particle light absorption of BC by 63 to 61 %, respectively, for data from the Arabian Sea sourced group, resulting in median BC absorption coefficients of 4.2 and 3.5 Mm-1. Corresponding values for the South Indian Ocean data were 69 and 97 % (0.38 and 0.02 Mm-1). A comparison with other studies in the area indicated an overestimation of their BC levels, by up to two orders of magnitude. This raises the necessity for chemical correction protocols on optical filter-based determinations of BC, before even the sign on the

  19. Study of Fricke-gel dosimeter calibration for attaining precise measurements of the absorbed dose

    SciTech Connect

    Liosi, Giulia Maria; Benedini, Sara; Giacobbo, Francesca

    2015-07-01

    A method has been studied for attaining, with good precision, absolute measurements of the spatial distribution of the absorbed dose by means of the Fricke gelatin Xylenol Orange dosimetric system. With this aim, the dose response to subsequent irradiations was analyzed. In fact, the proposed modality is based on a pre-irradiation of each single dosimeter in a uniform field with a known dose, in order to extrapolate a calibration image for a subsequent non-uniform irradiation with an un-known dose to be measured. (authors)

  20. Measurement of absorbed dose with a bone-equivalent extrapolation chamber.

    PubMed

    DeBlois, François; Abdel-Rahman, Wamied; Seuntjens, Jan P; Podgorsak, Ervin B

    2002-03-01

    A hybrid phantom-embedded extrapolation chamber (PEEC) made of Solid Water and bone-equivalent material was used for determining absorbed dose in a bone-equivalent phantom irradiated with clinical radiation beams (cobalt-60 gamma rays; 6 and 18 MV x rays; and 9 and 15 MeV electrons). The dose was determined with the Spencer-Attix cavity theory, using ionization gradient measurements and an indirect determination of the chamber air-mass through measurements of chamber capacitance. The collected charge was corrected for ionic recombination and diffusion in the chamber air volume following the standard two-voltage technique. Due to the hybrid chamber design, correction factors accounting for scatter deficit and electrode composition were determined and applied in the dose equation to obtain absorbed dose in bone for the equivalent homogeneous bone phantom. Correction factors for graphite electrodes were calculated with Monte Carlo techniques and the calculated results were verified through relative air cavity dose measurements for three different polarizing electrode materials: graphite, steel, and brass in conjunction with a graphite collecting electrode. Scatter deficit, due mainly to loss of lateral scatter in the hybrid chamber, reduces the dose to the air cavity in the hybrid PEEC in comparison with full bone PEEC by 0.7% to approximately 2% depending on beam quality and energy. In megavoltage photon and electron beams, graphite electrodes do not affect the dose measurement in the Solid Water PEEC but decrease the cavity dose by up to 5% in the bone-equivalent PEEC even for very thin graphite electrodes (<0.0025 cm). In conjunction with appropriate correction factors determined with Monte Carlo techniques, the uncalibrated hybrid PEEC can be used for measuring absorbed dose in bone material to within 2% for high-energy photon and electron beams.

  1. Absorbed dose estimates from a single measurement one to three days after the administration of 177Lu-DOTATATE/-TOC.

    PubMed

    Hänscheid, Heribert; Lapa, Constantin; Buck, Andreas K; Lassmann, Michael; Werner, Rudolf A

    2017-01-01

    To retrospectively analyze the accuracy of absorbed dose estimates from a single measurement of the activity concentrations in tumors and relevant organs one to three days after the administration of 177 Lu-DOTA-TATE/TOC assuming tissue specific effective half-lives. Activity kinetics in 54 kidneys, 30 neuroendocrine tumor lesions, 25 livers, and 27 spleens were deduced from series of planar images in 29 patients. After adaptation of mono- or bi-exponential fit functions to the measured data, it was analyzed for each fit function how precise the time integral can be estimated from fixed tissue-specific half-lives and a single measurement at 24, 48, or 72 h after the administration. For the kidneys, assuming a fixed tissue-specific half-life of 50 h, the deviations of the estimate from the actual integral were median (5 % percentile, 95 % percentile): -3 °% (-15 %>; +16 °%) for measurements after 24 h, +2 %> (-9 %>; +12 %>) for measurements after 48 h, and 0 % (-2 %; +12 %) for measurements after 72 h. The corresponding values for the other tissues, assuming fixed tissue-specific half-lives of 67 h for liver and spleen and 77 h for tumors, were +2 % (-25 %; +20 %) for measurements after 24 h, +2 °% (-16 %>; +17 %>) for measurements after 48 h, and +2 %> (-11 %>; +10 %>) for measurements after 72 h. Especially for the kidneys, which often represent the dose limiting organ, but also for liver, spleen, and neuroendocrine tumors, a meaningful absorbed dose estimate is possible from a single measurement after 2, more preferably 3 days after the administration of 177 Lu-DOTA-TATE/-TOC assuming fixed tissue specific effective half-lives. Schattauer GmbH.

  2. 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

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

    SciTech Connect

    Dubey, P. K., E-mail: premkdubey@gmail.com; Kumar, Yudhisther; Gupta, Reeta

    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 occursmore » 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.« less

  4. 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.

  5. 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.

  6. 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.

  7. Radiation force on absorbing targets and power measurements of a high intensity focused ultrasound (HIFU) source

    NASA Astrophysics Data System (ADS)

    Qian, Zuwen; Zhu, Zhemin; Ye, Shigong; Jiang, Wenhua; Zhu, Houqing; Yu, Jinshen

    2010-10-01

    Based on the analytic expressions for the radiated field of a circular concave piston given by Hasegawa et al., an integral for calculation of the radiation force on a plane absorbing target in a spherically focused field is derived. A general relation between acoustic power P and normal radiation force F n is obtained under the condition of kr ≫ 1. Numerical computation is carried out by using the symbolic computation program for practically focused sources and absorbing circular targets. The results show that, for a given source, there is a range of target positions where the radiation force is independent of the target’s position under the assumption that the contribution of the acoustic field behind the target to the radiation force can be neglected. The experiments are carried out and confirm that there is a range of target positions where the measured radiation force is basically independent of the target’s position even at high acoustic power (up to 700 W). It is believed that when the radiation force method is used to measure the acoustic power radiated from a focused source, the size of the target must be selected in such a way that no observable sound can be found in the region behind the target.

  8. 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.

  9. 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...

  10. Photophoretic trapping of absorbing particles in air and measurement of their single-particle Raman spectra.

    PubMed

    Pan, Yong-Le; Hill, Steven C; Coleman, Mark

    2012-02-27

    A new method is demonstrated for optically trapping micron-sized absorbing particles in air and obtaining their single-particle Raman spectra. A 488-nm Gaussian beam from an Argon ion laser is transformed by conical lenses (axicons) and other optics into two counter-propagating hollow beams, which are then focused tightly to form hollow conical beams near the trapping region. The combination of the two coaxial conical beams, with focal points shifted relative to each other along the axis of the beams, generates a low-light-intensity biconical region totally enclosed by the high-intensity light at the surface of the bicone, which is a type of bottle beam. Particles within this region are trapped by the photophoretic forces that push particles toward the low-intensity center of this region. Raman spectra from individual trapped particles made from carbon nanotubes are measured. This trapping technique could lead to the development of an on-line real-time single-particle Raman spectrometer for characterization of absorbing aerosol particles.

  11. Heating Rate of Light Absorbing Aerosols: Time-Resolved Measurements, the Role of Clouds, and Source Identification.

    PubMed

    Ferrero, Luca; Močnik, Griša; Cogliati, Sergio; Gregorič, Asta; Colombo, Roberto; Bolzacchini, Ezio

    2018-03-20

    Light absorbing aerosols (LAA) absorb sunlight and heat the atmosphere. This work presents a novel methodology to experimentally quantify the heating rate (HR) induced by LAA into an atmospheric layer. Multiwavelength aerosol absorption measurements were coupled with spectral measurements of the direct, diffuse and surface reflected radiation to obtain highly time-resolved measurements of HR apportioned in the context of LAA species (black carbon, BC; brown carbon, BrC; dust), sources (fossil fuel, FF; biomass burning, BB), and as a function of cloudiness. One year of continuous and time-resolved measurements (5 min) of HR were performed in the Po Valley. We experimentally determined (1) the seasonal behavior of HR (winter 1.83 ± 0.02 K day -1 ; summer 1.04 ± 0.01 K day -1 ); (2) the daily cycle of HR (asymmetric, with higher values in the morning than in the afternoon); (3) the HR in different sky conditions (from 1.75 ± 0.03 K day -1 in clear sky to 0.43 ± 0.01 K day -1 in complete overcast); (4) the apportionment to different sources: HR FF (0.74 ± 0.01 K day -1 ) and HR BB (0.46 ± 0.01 K day -1 ); and (4) the HR of BrC (HR BrC : 0.15 ± 0.01 K day -1 , 12.5 ± 0.6% of the total) and that of BC (HR BC : 1.05 ± 0.02 K day -1 ; 87.5 ± 0.6% of the total).

  12. Effects of consecutive wideband tympanometry trials on energy absorbance measures of the middle ear.

    PubMed

    Burdiek, Laina M; Sun, Xiao-Ming

    2014-10-01

    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 EA. Data were collected in 29 young adults with normal hearing and middle ear status. Before and after 8 successive WBTymp runs, EA was also measured at ambient pressure. Subsequently, two 226-Hz tympanometry tests were performed. EA systematically changed over the WBTymp trials in a frequency-specific manner: increase for low frequencies (below 1.5 kHz) and decrease for high frequencies (around 2 kHz and 5 to 6 kHz). The changes, although small, were significant. Much larger EA changes were measured at ambient pressure. The test-retest difference of 226-Hz tympanogram measures was much smaller than previously reported. Consecutive tympanometry testing alters EA measures of the middle ear. This phenomenon could be mainly attributed to change in stiffness at the eardrum, called tympanometric preconditioning. This also has effects on baseline WBTymp outcomes. This effect should be taken into account as a procedural variable in both research and clinical applications of WAI measurements.

  13. 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.

  14. Interferometer-Based Calorimetric Measurements of Absorbed Dose to Water in External Beam Radiotherapy

    NASA Astrophysics Data System (ADS)

    Flores-Martinez, Everardo

    Calorimetry is often used to establish high-energy photon absorbed dose to water (ADW) primary standards as calorimetry is a direct measurement of the energy imparted to the water by ionizing radiation. Current calorimeters use thermistors to establish national standards but there is the possibility of systematic errors in these instruments because thermistors overheat due to their low heat capacity. For this reason, there has been renewed interest in using alternative temperature measurement techniques, especially those that do not require a mechanical probe. Interferometer-based thermometry is a technique that exploits the temperature dependence of the refractive index of water and can be used as an alternative method for temperature measurement in radiation calorimetry. A distinctive advantage of the use of interferometry for radiation calorimetry is the capability of obtaining 2D or 3D temperature/dose distributions. Compared to thermistor-based measurements, the use of interferometer-based ADW measurements has been limited by the low measurement resolution. Optimized setups with higher accuracy and precision are necessary to perform measurements at clinically relevant dose rates. A calorimeter for thermistor-based ADW measurements was developed. The instrument was used to measure thermal drifts and noise were measured using the instrument in a water phantom. Residual thermal drifts were accounted for by using a three-step measurement protocol. Additionally, the instrument was used to measure ADW from a 6MV photon beam from a medical linear accelerator. A Michelson-type interferometer was built, characterized, and placed inside the calorimeter with the water phantom at the reference arm. Interferometer and phantom temperature fluctuations were minimized by means of the passive thermal control provide by the calorimeter enclosure, leading to increased fringe pattern stability. The interferometer characterization included phase shift measurements induced by

  15. Poly(dimethylsiloxane) photonic microbioreactors based on segmented waveguides for local absorbance measurement.

    PubMed

    Demming, Stefanie; Vila-Planas, Jordi; Aliasghar Zadeh, Sobehir; Edlich, Astrid; Franco-Lara, Ezequiel; Radespiel, Rolf; Büttgenbach, Stephanus; Llobera, Andreu

    2011-02-01

    We present the development of microbioreactors (MBRs) based on poly(dimethylsiloxane) (PDMS) segmented waveguides (SWG) for local absorbance measurements. Two different MBRs were studied, either using symmetric or asymmetric SWG (being defined as MBR-S and MBR-A, respectively). Their optical and fluidic performances were numerically analyzed, showing robustness from an optical point of view and distinct fluid flow profile. The optical characterization was done in two steps. Initially, the experimental limit of detection (LOD) and the sensitivity were determined for two different analytes (fluorescein and methylorange). With both systems, a similar limit of detection for both analytes was obtained, being in the micromolar level. Their sensitivities were 20.2±0.3 (×10⁻³) A.U./μM and 5.5±0.2 (×10⁻³) A.U./μM for fluorescein and methylorange, respectively. Once validated its applicability for local absorbance measurements, a continuous cultivation of Saccharomyces cerevisiae was done to test the viability of the proposed systems for photonic MBRs. Concretely, the cell growth was locally monitored inside the MBR during 33 h. Spectral analysis showed that the determination of the culture parameters were wavelength dependant, with a growth rate of 0.39±0.02 h⁻¹ and a doubling time of 1.65±0.09 h at an optimal wavelength of 469.9±0.3 nm. Besides the easy and monolithic integration of the SWG into poly(dimethylsiloxane) microfluidic systems, the results presented here are very promising for the application in any disposable photonic lab-on-a-chip systems used for online analysis or photonic MBRs. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Advantages of measuring the Q Stokes parameter in addition to the total radiance I in the detection of absorbing aerosols

    NASA Astrophysics Data System (ADS)

    Stamnes, Snorre; Fan, Yongzhen; Chen, Nan; Li, Wei; Tanikawa, Tomonori; Lin, Zhenyi; Liu, Xu; Burton, Sharon; Omar, Ali; Stamnes, Jakob J.; Cairns, Brian; Stamnes, Knut

    2018-05-01

    A simple but novel study was conducted to investigate whether an imager-type spectroradiometer instrument like MODIS, currently flying on board the Aqua and Terra satellites, or MERIS, which flew on board Envisat, could detect absorbing aerosols if they could measure the Q Stokes parameter in addition to the total radiance I, that is if they could also measure the linear polarization of the light. Accurate radiative transfer calculations were used to train a fast neural network forward model, which together with a simple statistical optimal estimation scheme was used to retrieve three aerosol parameters: aerosol optical depth at 869 nm, optical depth fraction of fine mode (absorbing) aerosols at 869 nm, and aerosol vertical location. The aerosols were assumed to be bimodal, each with a lognormal size distribution, located either between 0 and 2 km or between 2 and 4 km in the Earth's atmosphere. From simulated data with 3% random Gaussian measurement noise added for each Stokes parameter, it was found that by itself the total radiance I at the nine MODIS VIS channels was generally insufficient to accurately retrieve all three aerosol parameters (˜ 15% to 37% successful), but that together with the Q Stokes component it was possible to retrieve values of aerosol optical depth at 869 nm to ± 0.03, single-scattering albedo at 869 nm to ± 0.04, and vertical location in ˜ 65% of the cases. This proof-of-concept retrieval algorithm uses neural networks to overcome the computational burdens of using vector radiative transfer to accurately simulate top-of-atmosphere (TOA) total and polarized radiances, enabling optimal estimation techniques to exploit information from multiple channels. Therefore such an algorithm could, in concept, be readily implemented for operational retrieval of aerosol and ocean products from moderate or hyperspectral spectroradiometers.

  17. Analysis of reflectance spectra of UV-absorbing aerosol scenes measured by SCIAMACHY

    NASA Astrophysics Data System (ADS)

    de Graaf, M.; Stammes, P.; Aben, E. A. A.

    2007-01-01

    Reflectance spectra from 280-1750 nm of typical desert dust aerosol (DDA) and biomass burning aerosol (BBA) scenes over oceans are presented, measured by the space-borne spectrometer Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY). DDA and BBA are both UV-absorbing aerosols, but their effect on the top-of-atmosphere (TOA) reflectance is different due to differences in the way mineral aerosols and smoke reflect and absorb radiation. Mineral aerosols are typically large, inert particles, found in warm, dry continental air. Smoke particles, on the other hand, are usually small particles, although often clustered, chemically very active and highly variable in composition. Moreover, BBA are hygroscopic and over oceans BBA were invariably found in cloudy scenes. TOA reflectance spectra of typical DDA and BBA scenes were analyzed, using radiative transfer simulations, and compared. The DDA spectrum was successfully simulated using a layer with a bimodal size distribution of mineral aerosols in a clear sky. The spectrum of the BBA scene, however, was determined by the interaction between cloud droplets and smoke particles, as is shown by simulations with a model of separate aerosol and cloud layers and models with internally and externally mixed aerosol/cloud layers. The occurrence of clouds in smoke scenes when sufficient water vapor is present usually prevents the detection of optical properties of these aerosol plumes using space-borne sensors. However, the Absorbing Aerosol Index (AAI), a UV color index, is not sensitive to scattering aerosols and clouds and can be used to detect these otherwise obscured aerosol plumes over clouds. The amount of absorption of radiation can be expressed using the absorption optical thickness. The absorption optical thickness in the DDA case was 0.42 (340 nm) and 0.14 (550 nm) for an aerosol layer of optical thickness 1.74 (550 nm). In the BBA case the absorption optical thickness was 0.18 (340 nm) and 0

  18. Valuing vaccines using value of statistical life measures.

    PubMed

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

    2014-09-03

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Measurement of argon neutral velocity distribution functions near an absorbing boundary in a plasma

    NASA Astrophysics Data System (ADS)

    Short, Zachary; Thompson, Derek; Good, Timothy; Scime, Earl

    2016-10-01

    Neutral particle distributions are critical to the study of plasma boundary interactions, where ion-neutral collisions, e.g. via charge exchange, may modify energetic particle populations impacting the boundary surface. Neutral particle behavior at absorbing boundaries thus underlies a number of important plasma physics issues, such as wall loading in fusion devices and anomalous erosion in Hall thruster channels. Neutral velocity distribution functions (NVDFs) are measured using laser-induced fluorescence (LIF). Our LIF scheme excites the 1s4 non-metastable state of neutral argon with 667.913 nm photons. The subsequent decay emission at 750.590 nm is recorded synchronously with injection laser frequency. Measurements are performed near a grounded boundary immersed in a cylindrical helicon plasma, with the boundary plate oriented at an oblique angle to the magnetic field. NVDFs are recorded in multiple velocity dimensions and in a three-dimensional volume, enabling point-to-point comparisons with NVDF predictions from particle-in-cell models as well as comparisons with ion velocity distribution function measurements obtained in the same regions through Ar-II LIF. This work is supported by US National Science Foundation Grant Number PHYS-1360278.

  20. 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.

    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 andmore » 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.« less

  1. SU-F-T-175: Absorbed Dose Measurement Using Radiophotoluminescent Glass Dosimeter in Therapeutic Proton Beam

    SciTech Connect

    Chang, W; National Institute of Radiological Sciences, Chiba, Chiba; Koba, Y

    Purpose: To measure the absorbed dose to water Dw in therapeutic proton beam with radiophotoluminescent glass dosimeter (RGD), a methodology was proposed. In this methodology, the correction factor for the LET dependence of radiophotoluminescent (RPL) efficiency and the variation of mass stopping power ratio of water to RGD (SPRw, RGD) were adopted. The feasibility of proposed method was evaluated in this report. Methods: The calibration coefficient in terms of Dw for RGDs (GD-302M, Asahi Techno Glass) was obtained using 60Co beam. The SPRw, RGD was calculated by Monte Carlo simulation toolkit Geant4. The LET dependence of RPL efficiency was investigatedmore » experimentally by using a 70 MeV proton beam at National Institute of Radiological Sciences. For clinical usage, the residual range Rres was used as a quality index to determine the correction factor for RPL efficiency. The proposed method was evaluated by measuring Dw at difference depth in the 200 MeV proton beam. Results: For both modulated and non-modulated proton beam, the SPRw, RGD increases more than 3 % where Rres are less than 1 cm. RPL efficiency decreases with increasing LET and it reaches 0.6 at LET of 10 keV µm{sup −1}. Dw measured by RGD (Dw, RGD) shows good agreement with that measured by ionization chamber (Dw, IC) and the relative difference between Dw, RGD and Dw, IC are within 3 % where Rres is larger than 1 cm. Conclusion: In this work, a methodology for using RGD in proton dosimetry was proposed and the SPRw, RGD and the LET dependence of RPL efficiency in therapeutic proton beam was investigated. The results revealed that the proposed method is useful for RGD in the dosimetry of proton beams.« less

  2. Impacts of light-absorbing impurities on snow and their quantification with bidirectional reflectance measurements

    NASA Astrophysics Data System (ADS)

    Gritsevich, Maria; Peltoniemi, Jouni; Meinander, Outi; Dagsson-Waldhauserová, Pavla; Zubko, Nataliya; Hakala, Teemu; Virkkula, Aki; Svensson, Jonas; de Leeuw, Gerrit

    2017-04-01

    In order to quantify the effects of absorbing impurities on snow and define their contribution to the climate change, we have conducted a series of dedicated bidirectional reflectance measurements. Chimney soot, volcanic sand, and glaciogenic silt have been deposited on the snow in the controlled way. The bidirectional reflectance factors of these targets and untouched snow have been measured using the Finnish Geodetic Institute's field goniospectrometer FIGIFIGO, see, e.g., [1, 2] and references therein. It has been found that the contaminants darken the snow, and modify its appearance mostly as expected, with clear directional signal and modest spectral signal. A remarkable feature is the fact that any absorbing contaminant on snow enhances the metamorphosis under strong sunlight [3, 4]. Immediately after deposition, the contaminated snow surface appears darker than the pure snow in all viewing directions, but the heated soot particles start sinking down deeply into the snow in minutes. The nadir measurement remains darkest, but at larger zenith angles the surface of the soot-contaminated snow changes back to almost as white as clean snow. Thus, for on ground observer the darkening by impurities can be completely invisible, overestimating the albedo, but a nadir looking satellite sees the darkest points, now underestimating the albedo. After more time, also the nadir view brightens, and the remaining impurities may be biased towards more shadowed locations or less absorbing orientations by natural selection. This suggests that at noon the albedo should be lower than in the morning or afternoon. When sunlight stimulates more sinking than melting, albedo should be higher in the afternoon than in the morning, and vice versa when melting is dominating. Thus to estimate the effects caused by black carbon (BC) deposited on snow on climate changes may one need to take into account possible rapid diffusion of the BC inside the snow from its surface. When the snow melt

  3. A mathematical model for calculation of 90Sr absorbed dose in dental tissues: elaboration and comparison to EPR measurements.

    PubMed

    Shishkina, E A; Lyubashevskii, N M; Tolstykh, E I; Ignatiev, E A; Betenekova, T A; Nikiforov, S V

    2001-09-01

    A mathematical model for calculation of the 90Sr absorbed doses in dental tissues is presented. The results of the Monte-Carlo calculations are compared to the data obtained by EPR measurements of dental tissues. Radiometric measurements of the 90Sr concentrations. TLD and EPR dosimetry investigations were performed in animal (dog) study. The importance of the irregular 90Sr distribution in the dentine for absorbed dose formation has been shown. The dominant dose formation factors (main source-tissues) were identified for the crown dentine and enamel. The model has shown agreement with experimental data which allows to determine further directions of the human tooth model development.

  4. 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.

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

    PubMed

    Herzog, Bastian; Lemmer, Hilde; Horn, Harald; Müller, Elisabeth

    2014-02-22

    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. 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. 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.

  6. 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

  7. 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

    2016-08-02

    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.

  8. Measuring Work Values of Public School Administrators.

    ERIC Educational Resources Information Center

    Hales, Loyde W.; Waggoner, Jacqueline

    This paper presents the results of research investigating (1) the reliability and validity of the Ohio Work Values Inventory (OWVI) when used with public school administrators; (2) the work values of public school administrators; (3) differences in work values of male and female administrators; and (4) differences in work values of individuals at…

  9. 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.

  10. Sensitivity of multiangle photo-polarimetry to absorbing aerosol vertical layering and properties: Quantifying measurement uncertainties for ACE requirements

    NASA Astrophysics Data System (ADS)

    Kalashnikova, O. V.; Garay, M. J.; Davis, A. B.; Natraj, V.; Diner, D. J.; Tanelli, S.; Martonchik, J. V.; JPl Team

    2011-12-01

    The impact of tropospheric aerosols on climate can vary greatly based upon relatively small variations in aerosol properties, such as composition, shape and size distributions, as well as vertical layering. Multi-angle polarimetric measurements have been advocated in recent years as an additional tool to better understand and retrieve the aerosol properties needed for improved predictions of aerosol radiative forcing on climate. The central concern of this work is the assessment of the effects of absorbing aerosol properties under measurement uncertainties achievable for future generation multi-angle, polarimetric imaging instruments under ACE mission requirements. As guidelines, the on-orbit performance of MISR for multi-angle intensity measurements and the reported polarization sensitivities of a MSPI prototype were adopted. In particular, we will focus on sensitivities to absorbing aerosol layering and observation-constrained refractive indices (resulting in various single scattering albedos (SSA)) of both spherical and non-spherical absorbing aerosol types. We conducted modeling experiments to determine how the measured Stokes vector elements are affected in UV-NIR range by the vertical distribution, mixing and layering of smoke and dust aerosols, and aerosol SSA under the assumption of a black and polarizing ocean surfaces. We use a vector successive-orders-of-scattering (SOS) and VLIDORT transfer codes that show excellent agreement. Based on our sensitivity studies we will demonstrate advantages and disadvantages of wavelength selection in UV-NIR range to access absorbing aerosol properties. Polarized UV channels do not show particular advantage for absorbing aerosol property characterization due to dominating molecular signal. Polarimetric SSA sensitivity is small, however needed to be considered in the future polarimetric retrievals under ACE-defined uncertainty.

  11. 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.

  12. Intracardiac light catheter for rapid scanning transmural absorbance spectroscopy of perfused myocardium: measurement of myoglobin oxygenation and mitochondria redox state.

    PubMed

    Femnou, Armel N; Kuzmiak-Glancy, Sarah; Covian, Raul; Giles, Abigail V; Kay, Matthew W; Balaban, Robert S

    2017-12-01

    Absorbance spectroscopy of intrinsic cardiac chromophores provides nondestructive assessment of cytosolic oxygenation and mitochondria redox state. Isolated perfused heart spectroscopy is usually conducted by collecting reflected light from the heart surface, which represents a combination of surface scattering events and light that traversed portions of the myocardium. Reflectance spectroscopy with complex surface scattering effects in the beating heart leads to difficulty in quantitating chromophore absorbance. In this study, surface scattering was minimized and transmural path length optimized by placing a light source within the left ventricular chamber while monitoring transmurally transmitted light at the epicardial surface. The custom-designed intrachamber light catheter was a flexible coaxial cable (2.42-Fr) terminated with an encapsulated side-firing LED of 1.8 × 0.8 mm, altogether similar in size to a Millar pressure catheter. The LED catheter had minimal impact on aortic flow and heart rate in Langendorff perfusion and did not impact stability of the left ventricule of the working heart. Changes in transmural absorbance spectra were deconvoluted using a library of chromophore reference spectra to quantify the relative contribution of specific chromophores to the changes in measured absorbance. This broad-band spectral deconvolution approach eliminated errors that may result from simple dual-wavelength absorbance intensity. The myoglobin oxygenation level was only 82.2 ± 3.0%, whereas cytochrome c and cytochrome a + a 3 were 13.3 ± 1.4% and 12.6 ± 2.2% reduced, respectively, in the Langendorff-perfused heart. The intracardiac illumination strategy permits transmural optical absorbance spectroscopy in perfused hearts, which provides a noninvasive real-time monitor of cytosolic oxygenation and mitochondria redox state. NEW & NOTEWORTHY Here, a novel nondestructive real-time approach for monitoring intrinsic indicators of cardiac

  13. 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…

  14. 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.

  15. Postselected weak measurement beyond the weak value

    SciTech Connect

    Geszti, Tamas

    2010-04-15

    Closed expressions are derived for the quantum measurement statistics of pre- and postselected Gaussian particle beams. The weakness of the preselection step is shown to compete with the nonorthogonality of postselection in a transparent way. The approach is shown to be useful in analyzing postselection-based signal amplification, allowing measurements to be extended far beyond the range of validity of the well-known Aharonov-Albert-Vaidman limit. Additionally, the present treatment connects postselected weak measurement to the topic of phase-contrast microscopy.

  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.

  17. Measured values of coal mine stopping resistance

    SciTech Connect

    Oswald, N.; Prosser, B.; Ruckman, R.

    2008-12-15

    As coal mines become larger, the number of stoppings in the ventilation system increases. Each stopping represents a potential leakage path which must be adequately represented in the ventilation model. Stopping resistance can be calculated using two methods, the USBM method, used to determine a resistance for a single stopping, and the MVS technique, in which an average resistance is calculated for multiple stoppings. Through MVS data collected from ventilation surveys of different subsurface coal mines, average resistances for stoppings were determined for stopping in poor, average, good, and excellent conditions. The calculated average stoppings resistance were determined for concretemore » block and Kennedy stopping. Using the average stopping resistance, measured and calculated using the MVS method, provides a ventilation modeling tool which can be used to construct more accurate and useful ventilation models. 3 refs., 3 figs.« less

  18. 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.

  19. Secondary neutron dose measurement for proton eye treatment using an eye snout with a borated neutron absorber

    PubMed Central

    2013-01-01

    Background We measured and assessed ways to reduce the secondary neutron dose from a system for proton eye treatment. Methods Proton beams of 60.30 MeV were delivered through an eye-treatment snout in passive scattering mode. Allyl diglycol carbonate (CR-39) etch detectors were used to measure the neutron dose in the external field at 0.00, 1.64, and 6.00 cm depths in a water phantom. Secondary neutron doses were measured and compared between those with and without a high-hydrogen–boron-containing block. In addition, the neutron energy and vertices distribution were obtained by using a Geant4 Monte Carlo simulation. Results The ratio of the maximum neutron dose equivalent to the proton absorbed dose (H(10)/D) at 2.00 cm from the beam field edge was 8.79 ± 1.28 mSv/Gy. The ratio of the neutron dose equivalent to the proton absorbed dose with and without a high hydrogen-boron containing block was 0.63 ± 0.06 to 1.15 ± 0.13 mSv/Gy at 2.00 cm from the edge of the field at depths of 0.00, 1.64, and 6.00 cm. Conclusions We found that the out-of-field secondary neutron dose in proton eye treatment with an eye snout is relatively small, and it can be further reduced by installing a borated neutron absorbing material. PMID:23866307

  20. 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…

  1. Mushroom plasmonic metamaterial infrared absorbers

    SciTech Connect

    Ogawa, Shinpei, E-mail: Ogawa.Shimpei@eb.MitsubishiElectric.co.jp; Fujisawa, Daisuke; Hata, Hisatoshi

    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 bymore » 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.« less

  2. 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.

  3. Considerations on the calibration of small thermoluminescent dosimeters used for measurement of beta particle absorbed doses in liquid environments.

    PubMed

    Demidecki, A J; Williams, L E; Wong, J Y; Wessels, B W; Yorke, E D; Strandh, M; Strand, S E

    1993-01-01

    An investigation has been carried out on the factors which affect the absolute calibration of thermoluminescent dosimeters (TLDs) used in beta particle absorbed dose evaluations. Four effects on light output (LO) were considered: decay of detector sensitivity with time, finite TLD volume, dose linearity, and energy dependence. Most important of these was the decay of LO with time in culture medium, muscle tissue, and gels. This permanent loss of sensitivity was as large as an order of magnitude over a 21-day interval for the nominally 20-microns-thick disc-shaped CaSO4(Dy) TLDs in gel. Associated leaching of the dosimeter crystals out of the Teflon matrix was observed using scanning electron microscopy. Large channels leading from the outside environment into the TLDs were identified using SEM images. A possibility of batch dependence of fading was indicated. The second most important effect was the apparent reduction of light output due to finite size and increased specific gravity of the dosimeter (volume effect). We estimated this term by calculations as 10% in standard "mini" rods for beta particles from 90Y, but nearly a factor of 3 for 131I beta particles in the same geometry. No significant nonlinearity of the log (light output) with log (absorbed dose) over the range 0.05-20.00 Gy was discovered. Energy dependence of the LO was found to be not detectable, within measurement errors, over the range of 0.60-6.0 MeV mean energy electrons. With careful understanding of these effects, calibration via gel phantom would appear to be an acceptable strategy for mini TLDs used in beta absorbed dose evaluations in media.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. 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.

  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.

  7. 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…

  8. A Scaled-Projective Measure of Interpersonal Values

    ERIC Educational Resources Information Center

    Kilmann, Ralph H.

    1975-01-01

    The Kilmann Insight Test is a measure of the interpersonal value constructs. That is how the individual perceives and interprets the desirable and undesirable features of interpersonal behavior. The validity of the test is investigated by explaining its relationship to a self-report measure assessing similar values. (DEP)

  9. Application of stereo x-ray photogrammetry (SRM) in the determination of absorbed dose values during intracavitary radiation therapy

    SciTech Connect

    van Kleffens, H.J.; Star, W.M.

    1979-04-01

    The method of stereo x-ray photogrammetry is described, using a stereo x-ray comparator, as well as some clinical applications. The x-ray equipment consists of two x-ray tubes and a pneumatically driven cassette changer, developed to reduce effects of patient or organ motion between stero radiographs. The accuracy of the set-up is demonstated with measurements on a geometrical model and on a gelatine phantom containing radium needles. The clinical use is reported in determining dose rates to points of the intestinal wall during intracavitary radiotherapy of gynecological cancer. In a number of cases the stereo measurements have resulted in a changemore » in the application time or in the charge or position of the applicator, possibly preventing later complications, as a result of a high dose. Future applications for implant dosimetry (/sup 192/Ir, /sup 125/I) are suggested.« less

  10. 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.

  11. Simulation and Measurement of Absorbed Dose from 137 Cs Gammas Using a Si Timepix Detector

    NASA Technical Reports Server (NTRS)

    Stoffle, Nicholas; Pinsky, Lawrence; Empl, Anton; Semones, Edward

    2011-01-01

    The TimePix readout chip is a hybrid pixel detector with over 65k independent pixel elements. Each pixel contains its own circuitry for charge collection, counting logic, and readout. When coupled with a Silicon detector layer, the Timepix chip is capable of measuring the charge, and thus energy, deposited in the Silicon. Measurements using a NIST traceable 137Cs gamma source have been made at Johnson Space Center using such a Si Timepix detector, and this data is compared to simulations of energy deposition in the Si layer carried out using FLUKA.

  12. Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

    PubMed

    Harada, Kazuki; Maeda, Toshimichi; Hasegawa, Yoshiro; Tokunaga, Takushi; Ogawa, Shinya; Fukuda, Kyoko; Nagatsuka, Norie; Nagao, Keiko; Ueno, Shunshiro

    2011-01-01

    The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

  13. Factors that introduce intrasubject variability into ear-canal absorbance measurements.

    PubMed

    Voss, Susan E; Stenfelt, Stefan; Neely, Stephen T; Rosowski, John J

    2013-07-01

    Wideband immittance measures can be useful in analyzing acoustic sound flow through the ear and also have diagnostic potential for the identification of conductive hearing loss as well as causes of conductive hearing loss. To interpret individual measurements, the variability in test–retest data must be described and quantified. Contributors to variability in ear-canal absorbance–based measurements are described in this article. These include assumptions related to methodologies and issues related to the probe fit within the ear and potential acoustic leaks. Evidence suggests that variations in ear-canal cross-sectional area or measurement location are small relative to variability within a population. Data are shown to suggest that the determination of the Thévenin equivalent of the ER-10C probe introduces minimal variability and is independent of the foam ear tip itself. It is suggested that acoustic leaks in the coupling of the ear tip to the ear canal lead to substantial variations and that this issue needs further work in terms of potential criteria to identify an acoustic leak. In addition, test–retest data from the literature are reviewed.

  14. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. 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.

  16. Use of a heated graphite scrubber as a means of reducing interferences in UV-absorbance measurements of atmospheric ozone

    NASA Astrophysics Data System (ADS)

    Turnipseed, Andrew A.; Andersen, Peter C.; Williford, Craig J.; Ennis, Christine A.; Birks, John W.

    2017-06-01

    A new solid-phase scrubber for use in conventional ozone (O3) photometers was investigated as a means of reducing interferences from other UV-absorbing species and water vapor. It was found that when heated to 100-130 °C, a tubular graphite scrubber efficiently removed up to 500 ppb ozone and ozone monitors using the heated graphite scrubber were found to be less susceptible to interferences from water vapor, mercury vapor, and aromatic volatile organic compounds (VOCs) compared to conventional metal oxide scrubbers. Ambient measurements from a graphite scrubber-equipped photometer and a co-located Federal equivalent method (FEM) ozone analyzer showed excellent agreement over 38 days of measurements and indicated no loss in the scrubber's ability to remove ozone when operated at 130 °C. The use of a heated graphite scrubber was found to reduce the interference from mercury vapor to ≤ 3 % of that obtained using a packed-bed Hopcalite scrubber. For a series of substituted aromatic compounds (ranging in volatility and absorption cross section at 253.7 nm), the graphite scrubber was observed to consistently exhibit reduced levels of interference, typically by factors of 2.5 to 20 less than with Hopcalite. Conventional solid-phase scrubbers also exhibited complex VOC adsorption and desorption characteristics that were dependent upon the relative humidity (RH), volatility of the VOC, and the available surface area of the scrubber. This complex behavior involving humidity is avoided by use of a heated graphite scrubber. These results suggest that heated graphite scrubbers could be substituted in most ozone photometers as a means of reducing interferences from other UV-absorbing species found in the atmosphere. This could be particularly important in ozone monitoring for compliance with the United States (U.S.) Clean Air Act or for use in VOC-rich environments such as in smog chambers and monitoring indoor air quality.

  17. A framework to measure the value of public health services.

    PubMed

    Jacobson, Peter D; Neumann, Peter J

    2009-10-01

    To develop a framework that public health practitioners could use to measure the value of public health services. Primary data were collected from August 2006 through March 2007. We interviewed (n=46) public health practitioners in four states, leaders of national public health organizations, and academic researchers. Using a semi-structured interview protocol, we conducted a series of qualitative interviews to define the component parts of value for public health services and identify methodologies used to measure value and data collected. The primary form of analysis is descriptive, synthesizing information across respondents as to how they measure the value of their services. Our interviews did not reveal a consensus on how to measure value or a specific framework for doing so. Nonetheless, the interviews identified some potential strategies, such as cost accounting and performance-based contracting mechanisms. The interviews noted implementation barriers, including limits to staff capacity and data availability. We developed a framework that considers four component elements to measure value: external factors that must be taken into account (i.e., mandates); key internal actions that a local health department must take (i.e., staff assessment); using appropriate quantitative measures; and communicating value to elected officials and the public.

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

    DOE PAGES

    Guillen, Donna Post; Harris, William H.

    2016-05-11

    A metal matrix composite (MMC) material comprised 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. Our purpose 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. Thus, a test procedure was developed to perform DSC and laser flashmore » 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. Furthermore, the ability of this material to effectively conduct heat as a function of temperature, volume fraction Al 3Hf, radiation damage and annealing is assessed using the MOOSE suite of computational tools.« less

  19. [A new method for quantitative measurement of the cadmium absorbed by chick embryos].

    PubMed

    Gottofrey, J

    1984-01-01

    We attempted to determine the quantity of cadmium incorporated in hens eggs after immersion in cadmium solutions, and the cadmium concentration measured in embryos. We discussed equipment allowing simultaneous treatment of up to 42 samples, and called it " digestor ". It consisted of two gas-heated sand baths, two stands for cooling down solutions and an evacuation system for toxic vapours. Our method was based on wet mineralisation. It consisted of desintegrating experimental chick embryos in a HNO3/H2O2 mixed solution. After heating and evaporating, the quantity of cadmium in the remnant was determined by atomic absorption spectrophotometry. The reliability of such a technique was tested by studying as controls controls 17 days-old chick embryos injected with a known quantity of Cd(NO3). It showed no loss of cadmium. We also compared our procedure with a dry ashing method. The latter showed unacceptable losses and insufficient precision for the problems we wanted to investigate. Our method gave us much more precise results. The equipment we developed has functioned wholly satisfactorily and allowed us to investigate for instance cadmium distribution and concentration in embryonic organs of 17 days-old chicks. It could also be useful for researches concerning other biological samples analyzed for different heavy metals.

  20. Measuring Incompatible Observables by Exploiting Sequential Weak Values.

    PubMed

    Piacentini, F; Avella, A; Levi, M P; Gramegna, M; Brida, G; Degiovanni, I P; Cohen, E; Lussana, R; Villa, F; Tosi, A; Zappa, F; Genovese, M

    2016-10-21

    One of the most intriguing aspects of quantum mechanics is the impossibility of measuring at the same time observables corresponding to noncommuting operators, because of quantum uncertainty. This impossibility can be partially relaxed when considering joint or sequential weak value evaluation. Indeed, weak value measurements have been a real breakthrough in the quantum measurement framework that is of the utmost interest from both a fundamental and an applicative point of view. In this Letter, we show how we realized for the first time a sequential weak value evaluation of two incompatible observables using a genuine single-photon experiment. These (sometimes anomalous) sequential weak values revealed the single-operator weak values, as well as the local correlation between them.

  1. Measuring Incompatible Observables by Exploiting Sequential Weak Values

    NASA Astrophysics Data System (ADS)

    Piacentini, F.; Avella, A.; Levi, M. P.; Gramegna, M.; Brida, G.; Degiovanni, I. P.; Cohen, E.; Lussana, R.; Villa, F.; Tosi, A.; Zappa, F.; Genovese, M.

    2016-10-01

    One of the most intriguing aspects of quantum mechanics is the impossibility of measuring at the same time observables corresponding to noncommuting operators, because of quantum uncertainty. This impossibility can be partially relaxed when considering joint or sequential weak value evaluation. Indeed, weak value measurements have been a real breakthrough in the quantum measurement framework that is of the utmost interest from both a fundamental and an applicative point of view. In this Letter, we show how we realized for the first time a sequential weak value evaluation of two incompatible observables using a genuine single-photon experiment. These (sometimes anomalous) sequential weak values revealed the single-operator weak values, as well as the local correlation between them.

  2. 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.

  3. 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.

  4. Measurement Theory Based on the Truth Values Violates Local Realism

    NASA Astrophysics Data System (ADS)

    Nagata, Koji

    2017-02-01

    We investigate the violation factor of the Bell-Mermin inequality. Until now, we use an assumption that the results of measurement are ±1. In this case, the maximum violation factor is 2( n-1)/2. The quantum predictions by n-partite Greenberger-Horne-Zeilinger (GHZ) state violate the Bell-Mermin inequality by an amount that grows exponentially with n. Recently, a new measurement theory based on the truth values is proposed (Nagata and Nakamura, Int. J. Theor. Phys. 55:3616, 2016). The values of measurement outcome are either +1 or 0. Here we use the new measurement theory. We consider multipartite GHZ state. It turns out that the Bell-Mermin inequality is violated by the amount of 2( n-1)/2. The measurement theory based on the truth values provides the maximum violation of the Bell-Mermin inequality.

  5. TH-CD-201-09: High Spatial Resolution Absorbed Dose to Water Measurements Using Optical Calorimetry in Megavoltage External Beam Therapy

    SciTech Connect

    Flores-Martinez, E; DeWerd, L; Radtke, J

    2016-06-15

    Purpose: To develop and implement a high spatial resolution calorimeter methodology to measure absorbed dose to water (ADW) using phase shifts (PSs) of light passing through a water phantom and to compare measurements with theoretical calculations. Methods: Radiation-induced temperature changes were measured using the PSs of a He-Ne laser beam passing through a (10×10×10) cm{sup 3} water phantom. PSs were measured using a Michelson interferometer and recording the time-dependent fringe patterns on a CCD camera. The phantom was positioned at the center of the radiation field. A Varian 21EX was used to deliver 500 MU from a 9 MeV beammore » using a (6×6) cm{sup 2} cone. A 127cm SSD was used and the PSs were measured at depths ranging from of 1.90cm to 2.10cm in steps of 0.05cm by taking profiles at the corresponding rows across the image. PSs were computed by taking the difference between pre- and post-irradiation image frames and then measuring the amplitude of the resulting image profiles. An amplitude-to-PS calibration curve was generated using a piezoelectric transducer to mechanically induce PSs between 0.05 and 1.50 radians in steps of 0.05 radians. The temperature dependence of the refractive index of water at 632.8nm was used to convert PSs to ADW. Measured results were compared with ADW values calculated using the linac output calibration and commissioning data. Results: Milli-radian resolution in PS measurement was achieved using the described methodology. Measured radiation-induced PSs ranged from 0.10 ± 0.01 to 0.12 ± 0.01 radians at the investigated depths. After converting PSs to ADW, measured and calculated ADW values agreed within the measurement uncertainty. Conclusion: This work shows that interferometer-based calorimetry measurements are capable of achieving sub-millimeter resolution measuring 2D temperature/dose distributions, which are particularly useful for characterizing beams from modalities such as SRS, proton therapy, or microbeams.« less

  6. 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.

  7. A Framework for Measuring Low-Value Care.

    PubMed

    Miller, George; Rhyan, Corwin; Beaudin-Seiler, Beth; Hughes-Cromwick, Paul

    2018-04-01

    It has been estimated that more than 30% of health care spending in the United States is wasteful, and that low-value care, which drives up costs unnecessarily while increasing patient risk, is a significant component of wasteful spending. To address the need for an ability to measure the magnitude of low-value care nationwide, identify the clinical services that are the greatest contributors to waste, and track progress toward eliminating low-value use of these services. Such an ability could provide valuable input to the efforts of policymakers and health systems to improve efficiency. We reviewed existing methods that could contribute to measuring low-value care and developed an integrated framework that combines multiple methods to comprehensively estimate and track the magnitude and principal sources of clinical waste. We also identified a process and needed research for implementing the framework. A comprehensive methodology for measuring and tracking low-value care in the United States would provide an important contribution toward reducing waste. Implementation of the framework described in this article appears feasible, and the proposed research program will allow moving incrementally toward full implementation while providing a near-term capability for measuring low-value care that can be enhanced over time. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  8. Ferrite HOM Absorber for the RHIC ERL

    SciTech Connect

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

    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 measurementsmore » of the finished niobium cavity are presented which confirm the effective damping of higher-order modes in the ERL. by the ferrite absorbers.« less

  9. 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

  10. [Implicit value judgments in the measurement of health inequalities].

    PubMed

    Harper, Sam; King, Nicholas B; Meersman, Stephen C; E Reichman, Marsha; Breen, Nancy; Lynch, John

    2014-04-01

    Quantitative estimates of the magnitude, direction, and rate of change of health inequalities play a crucial role in creating and assessing policies aimed at eliminating the disproportionate burden of disease in disadvantaged populations. It is generally assumed that the measurement of health inequalities is a value-neutral process, providing objective data that are then interpreted using normative judgments about whether a particular distribution of health is just, fair, or socially acceptable. We discuss five examples in which normative judgments play a role in the measurement process itself, through either the selection of one measurement strategy to the exclusion of others or the selection of the type, significance, or weight assigned to the variables being measured. Overall, we find that many commonly used measures of inequality are value laden and that the normative judgments implicit in these measures have important consequences for interpreting and responding to health inequalities. Because values implicit in the generation of health inequality measures may lead to radically different interpretations of the same underlying data,we urge researchers to explicitly consider and transparently discuss the normative judgments underlying their measures. We also urge policymakers and other consumers of health inequalities data to pay close attention to the measures on which they base their assessments of current and future health policies.

  11. Implicit value judgments in the measurement of health inequalities.

    PubMed

    Harper, Sam; King, Nicholas B; Meersman, Stephen C; Reichman, Marsha E; Breen, Nancy; Lynch, John

    2010-03-01

    Quantitative estimates of the magnitude, direction, and rate of change of health inequalities play a crucial role in creating and assessing policies aimed at eliminating the disproportionate burden of disease in disadvantaged populations. It is generally assumed that the measurement of health inequalities is a value-neutral process, providing objective data that are then interpreted using normative judgments about whether a particular distribution of health is just, fair, or socially acceptable. We discuss five examples in which normative judgments play a role in the measurement process itself, through either the selection of one measurement strategy to the exclusion of others or the selection of the type, significance, or weight assigned to the variables being measured. Overall, we find that many commonly used measures of inequality are value laden and that the normative judgments implicit in these measures have important consequences for interpreting and responding to health inequalities. Because values implicit in the generation of health inequality measures may lead to radically different interpretations of the same underlying data, we urge researchers to explicitly consider and transparently discuss the normative judgments underlying their measures. We also urge policymakers and other consumers of health inequalities data to pay close attention to the measures on which they base their assessments of current and future health policies.

  12. 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. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  13. Absorbed dose evaluation of Auger electron-emitting radionuclides: impact of input decay spectra on dose point kernels and S-values

    NASA Astrophysics Data System (ADS)

    Falzone, Nadia; Lee, Boon Q.; Fernández-Varea, José M.; Kartsonaki, Christiana; Stuchbery, Andrew E.; Kibédi, Tibor; Vallis, Katherine A.

    2017-03-01

    The aim of this study was to investigate the impact of decay data provided by the newly developed stochastic atomic relaxation model BrIccEmis on dose point kernels (DPKs - radial dose distribution around a unit point source) and S-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE) emitting radionuclides, namely 67Ga, 80mBr, 89Zr, 90Nb, 99mTc, 111In, 117mSn, 119Sb, 123I, 124I, 125I, 135La, 195mPt and 201Tl. Radiation spectra were based on the nuclear decay data from the medical internal radiation dose (MIRD) RADTABS program and the BrIccEmis code, assuming both an isolated-atom and condensed-phase approach. DPKs were simulated with the PENELOPE Monte Carlo (MC) code using event-by-event electron and photon transport. S-values for concentric spherical cells of various sizes were derived from these DPKs using appropriate geometric reduction factors. The number of Auger and Coster-Kronig (CK) electrons and x-ray photons released per nuclear decay (yield) from MIRD-RADTABS were consistently higher than those calculated using BrIccEmis. DPKs for the electron spectra from BrIccEmis were considerably different from MIRD-RADTABS in the first few hundred nanometres from a point source where most of the Auger electrons are stopped. S-values were, however, not significantly impacted as the differences in DPKs in the sub-micrometre dimension were quickly diminished in larger dimensions. Overestimation in the total AE energy output by MIRD-RADTABS leads to higher predicted energy deposition by AE emitting radionuclides, especially in the immediate vicinity of the decaying radionuclides. This should be taken into account when MIRD-RADTABS data are used to simulate biological damage at nanoscale dimensions.

  14. English Value-Added Measures: Examining the Limitations of School Performance Measurement

    ERIC Educational Resources Information Center

    Perry, Thomas

    2016-01-01

    Value-added "Progress" measures are to be introduced for all English schools in 2016 as "headline" measures of school performance. This move comes despite research highlighting high levels of instability in value-added measures and concerns about the omission of contextual variables in the planned measure. This article studies…

  15. Measuring Values in Environmental Research: A Test of an Environmental Portrait Value Questionnaire

    PubMed Central

    Bouman, Thijs; Steg, Linda; Kiers, Henk A. L.

    2018-01-01

    Four human values are considered to underlie individuals’ environmental beliefs and behaviors: biospheric (i.e., concern for environment), altruistic (i.e., concern for others), egoistic (i.e., concern for personal resources) and hedonic values (i.e., concern for pleasure and comfort). These values are typically measured with an adapted and shortened version of the Schwartz Value Survey (SVS), to which we refer as the Environmental-SVS (E-SVS). Despite being well-validated, recent research has indicated some concerns about the SVS methodology (e.g., comprehensibility, self-presentation biases) and suggested an alternative method of measuring human values: The Portrait Value Questionnaire (PVQ). However, the PVQ has not yet been adapted and applied to measure values most relevant to understand environmental beliefs and behaviors. Therefore, we tested the Environmental-PVQ (E-PVQ) – a PVQ variant of E-SVS –and compared it with the E-SVS in two studies. Our findings provide strong support for the validity and reliability of both the E-SVS and E-PVQ. In addition, we find that respondents slightly preferred the E-PVQ over the E-SVS (Study 1). In general, both scales correlate similarly to environmental self-identity (Study 1), energy behaviors (Studies 1 and 2), pro-environmental personal norms, climate change beliefs and policy support (Study 2). Accordingly, both methodologies show highly similar results and seem well-suited for measuring human values underlying environmental behaviors and beliefs. PMID:29743874

  16. 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.

  17. Comparison of ultraviolet absorbance and NO-chemiluminescence for ozone measurement in wildfire plumes at the Mount Bachelor Observatory

    NASA Astrophysics Data System (ADS)

    Gao, Honglian; Jaffe, Daniel A.

    2017-10-01

    The goal of this paper is to evaluate the accuracy of the commonly used ozone (O3) instrument (the ultraviolet (UV) photometer) against a Federal Reference Method (Nitric Oxide -chemiluminescence) for ozone measurement in wildfire smoke plumes. We carried out simultaneous ozone measurement with two UV O3 photometers and one nitric oxide-chemiluminescence (NO-CL) ozone detectors during wildfire season (Aug. 1-Sept. 30) in 2015 at the Mount Bachelor Observatory (MBO, 2763 m above mean sea level, Oregon, USA). The UV O3 shows good agreement and excellent correlation to NO-CL O3, with linear regression slopes close to unity and R2 of 0.92 for 1-h average data and R2 of 0.93 for O3 daily maximum 8-h average (MDA8). During this two-month period we identified 35 wildfire events. Ozone enhancements in those wildfire plumes measured by NO-CL O3 and UV O3 monitors also show good agreement and excellent linear correlation, with a slope and R2 of 1.03 and 0.86 for O3 enhancements (ΔO3) and 1.00 and 0.98 for carbon monoxide (CO)-normalized ozone enhancement ratios (ΔO3/ΔCO), respectively. Overall, the UV O3 was found to have a positive bias of 4.7 ± 2.8 ppbv compared to the NO-CL O3. The O3 bias between NO-CL O3 and UV O3 is independent of wildfire plume tracers such as CO, particulate matter (PM1), aerosol scattering, and ultrafine particles. The results demonstrate that the UV O3 absorbance method is reliable, even in highly concentrated wildfire plumes.

  18. 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

  19. Measure-valued solutions to the complete Euler system revisited

    NASA Astrophysics Data System (ADS)

    Březina, Jan; Feireisl, Eduard

    2018-06-01

    We consider the complete Euler system describing the time evolution of a general inviscid compressible fluid. We introduce a new concept of measure-valued solution based on the total energy balance and entropy inequality for the physical entropy without any renormalization. This class of so-called dissipative measure-valued solutions is large enough to include the vanishing dissipation limits of the Navier-Stokes-Fourier system. Our main result states that any sequence of weak solutions to the Navier-Stokes-Fourier system with vanishing viscosity and heat conductivity coefficients generates a dissipative measure-valued solution of the Euler system under some physically grounded constitutive relations. Finally, we discuss the same asymptotic limit for the bi-velocity fluid model introduced by H.Brenner.

  20. 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.

  1. Weak measurements and quantum weak values for NOON states

    NASA Astrophysics Data System (ADS)

    Rosales-Zárate, L.; Opanchuk, B.; Reid, M. D.

    2018-03-01

    Quantum weak values arise when the mean outcome of a weak measurement made on certain preselected and postselected quantum systems goes beyond the eigenvalue range for a quantum observable. Here, we propose how to determine quantum weak values for superpositions of states with a macroscopically or mesoscopically distinct mode number, that might be realized as two-mode Bose-Einstein condensate or photonic NOON states. Specifically, we give a model for a weak measurement of the Schwinger spin of a two-mode NOON state, for arbitrary N . The weak measurement arises from a nondestructive measurement of the two-mode occupation number difference, which for atomic NOON states might be realized via phase contrast imaging and the ac Stark effect using an optical meter prepared in a coherent state. The meter-system coupling results in an entangled cat-state. By subsequently evolving the system under the action of a nonlinear Josephson Hamiltonian, we show how postselection leads to quantum weak values, for arbitrary N . Since the weak measurement can be shown to be minimally invasive, the weak values provide a useful strategy for a Leggett-Garg test of N -scopic realism.

  2. The Valued Living Questionnaire: Defining and Measuring Valued Action within a Behavioral Framework

    ERIC Educational Resources Information Center

    Wilson, Kelly G.; Sandoz, Emily K.; Kitchens, Jennifer; Roberts, Miguel

    2010-01-01

    A number of cognitive-behavior therapies now strongly emphasize particular behavioral processes as mediators of clinical change specific to that therapy. This shift in emphasis calls for the development of measures sensitive to changes in the therapies' processes. Among these is acceptance and commitment therapy (ACT), which posits valued living…

  3. How to Use Value-Added Measures Right

    ERIC Educational Resources Information Center

    Di Carlo, Matthew

    2012-01-01

    Value-added models are a specific type of "growth model," a diverse group of statistical techniques to isolate a teacher's impact on his or her students' testing progress while controlling for other measurable factors, such as student and school characteristics, that are outside that teacher's control. Opponents, including many teachers, argue…

  4. 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…

  5. 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…

  6. 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…

  7. Bayes' theorem application in the measure information diagnostic value assessment

    NASA Astrophysics Data System (ADS)

    Orzechowski, Piotr D.; Makal, Jaroslaw; Nazarkiewicz, Andrzej

    2006-03-01

    The paper presents Bayesian method application in the measure information diagnostic value assessment that is used in the computer-aided diagnosis system. The computer system described here has been created basing on the Bayesian Network and is used in Benign Prostatic Hyperplasia (BPH) diagnosis. The graphic diagnostic model enables to juxtapose experts' knowledge with data.

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

    SciTech Connect

    Muir, B. R., E-mail: Bryan.Muir@nrc-cnrc.gc.ca

    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 measuredmore » 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

  9. Reverse engineering gene regulatory networks from measurement with missing values.

    PubMed

    Ogundijo, Oyetunji E; Elmas, Abdulkadir; Wang, Xiaodong

    2016-12-01

    Gene expression time series data are usually in the form of high-dimensional arrays. Unfortunately, the data may sometimes contain missing values: for either the expression values of some genes at some time points or the entire expression values of a single time point or some sets of consecutive time points. This significantly affects the performance of many algorithms for gene expression analysis that take as an input, the complete matrix of gene expression measurement. For instance, previous works have shown that gene regulatory interactions can be estimated from the complete matrix of gene expression measurement. Yet, till date, few algorithms have been proposed for the inference of gene regulatory network from gene expression data with missing values. We describe a nonlinear dynamic stochastic model for the evolution of gene expression. The model captures the structural, dynamical, and the nonlinear natures of the underlying biomolecular systems. We present point-based Gaussian approximation (PBGA) filters for joint state and parameter estimation of the system with one-step or two-step missing measurements . The PBGA filters use Gaussian approximation and various quadrature rules, such as the unscented transform (UT), the third-degree cubature rule and the central difference rule for computing the related posteriors. The proposed algorithm is evaluated with satisfying results for synthetic networks, in silico networks released as a part of the DREAM project, and the real biological network, the in vivo reverse engineering and modeling assessment (IRMA) network of yeast Saccharomyces cerevisiae . PBGA filters are proposed to elucidate the underlying gene regulatory network (GRN) from time series gene expression data that contain missing values. In our state-space model, we proposed a measurement model that incorporates the effect of the missing data points into the sequential algorithm. This approach produces a better inference of the model parameters and hence

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

    PubMed Central

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

    2012-01-01

    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

  11. 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.

  12. Measure Your Gradient”: A New Way to Measure Gradients in High Performance Liquid Chromatography by Mass Spectrometric or Absorbance Detection

    PubMed Central

    Magee, Megan H.; Manulik, Joseph C.; Barnes, Brian B.; Abate-Pella, Daniel; Hewitt, Joshua T.; Boswell, Paul G.

    2014-01-01

    The gradient produced by an HPLC is never the same as the one it is programmed to produce, but non-idealities in the gradient can be taken into account if they are measured. Such measurements are routine, yet only one general approach has been described to make them: both HPLC solvents are replaced with water, solvent B is spiked with 0.1% acetone, and the gradient is measured by UV absorbance. Despite the widespread use of this procedure, we found a number of problems and complications with it, mostly stemming from the fact that it measures the gradient under abnormal conditions (e.g. both solvents are water). It is also generally not amenable to MS detection, leaving those with only an MS detector no way to accurately measure their gradients. We describe a new approach called “Measure Your Gradient” that potentially solves these problems. One runs a test mixture containing 20 standards on a standard stationary phase and enters their gradient retention times into open-source software available at www.measureyourgradient.org. The software uses the retention times to back-calculate the gradient that was truly produced by the HPLC. Here we present a preliminary investigation of the new approach. We found that gradients measured this way are comparable to those measured by a more accurate, albeit impractical, version of the conventional approach. The new procedure worked with different gradients, flow rates, column lengths, inner diameters, on two different HPLCs, and with six different batches of the standard stationary phase. PMID:25441073

  13. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Reference value sensitivity of measures of unfair health inequality

    PubMed Central

    García-Gómez, Pilar; Schokkaert, Erik; Van Ourti, Tom

    2014-01-01

    Most politicians and ethical observers are not interested in pure health inequalities, as they want to distinguish between different causes of health differences. Measures of “unfair” inequality - direct unfairness and the fairness gap, but also the popular standardized concentration index - therefore neutralize the effects of what are considered to be “legitimate” causes of inequality. This neutralization is performed by putting a subset of the explanatory variables at reference values, e.g. their means. We analyze how the inequality ranking of different policies depends on the specific choice of reference values. We show with mortality data from the Netherlands that the problem is empirically relevant and we suggest a statistical method for fixing the reference values. PMID:24954998

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  16. Absorbed dose thresholds and absorbed dose rate limitations for studies of electron radiation effects on polyetherimides

    NASA Technical Reports Server (NTRS)

    Long, Edward R., Jr.; Long, Sheila Ann T.; Gray, Stephanie L.; Collins, William D.

    1989-01-01

    The threshold values of total absorbed dose for causing changes in tensile properties of a polyetherimide film and the limitations of the absorbed dose rate for accelerated-exposure evaluation of the effects of electron radiation in geosynchronous orbit were studied. Total absorbed doses from 1 kGy to 100 MGy and absorbed dose rates from 0.01 MGy/hr to 100 MGy/hr were investigated, where 1 Gy equals 100 rads. Total doses less than 2.5 MGy did not significantly change the tensile properties of the film whereas doses higher than 2.5 MGy significantly reduced elongation-to-failure. There was no measurable effect of the dose rate on the tensile properties for accelerated electron exposures.

  17. Extracting joint weak values with local, single-particle measurements.

    PubMed

    Resch, K J; Steinberg, A M

    2004-04-02

    Weak measurement is a new technique which allows one to describe the evolution of postselected quantum systems. It appears to be useful for resolving a variety of thorny quantum paradoxes, particularly when used to study properties of pairs of particles. Unfortunately, such nonlocal or joint observables often prove difficult to measure directly in practice (for instance, in optics-a common testing ground for this technique-strong photon-photon interactions would be needed to implement an appropriate von Neumann interaction). Here we derive a general, experimentally feasible, method for extracting these joint weak values from correlations between single-particle observables.

  18. Weak values in continuous weak measurements of qubits

    NASA Astrophysics Data System (ADS)

    Qin, Lupei; Liang, Pengfei; Li, Xin-Qi

    2015-07-01

    For continuous weak measurements of qubits, we obtain exact expressions for weak values (WVs) from the postselection restricted average of measurement outputs, by using both the quantum-trajectory equation (QTE) and the quantum Bayesian approach. The former is applicable to short-time weak measurement, while the latter can relax the measurement strength to finite. We find that even in the "very" weak limit the result can be essentially different from the one originally proposed by Aharonov, Albert, and Vaidman (AAV), in the sense that our result incorporates nonperturbative correction which could be important when the AAV WV is large. Within the Bayesian framework, we obtain also elegant expressions for finite measurement strength and find that the amplifier's noise in quantum measurement has no effect on the WVs. In particular, we obtain very useful results for homodyne measurement in a circuit-QED system, which allows for measuring the real and imaginary parts of the AAV WV by simply tuning the phase of the local oscillator. This advantage can be exploited as an efficient state-tomography technique.

  19. 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.

  20. Negative measurement sensitivity values of planar capacitive imaging probes

    NASA Astrophysics Data System (ADS)

    Yin, Xiaokang; Chen, Guoming; Li, Wei; Hutchins, David

    2014-02-01

    The measurement sensitivity distribution of planar capacitive imaging (CI) probes describes how effectively each region in the sensing area is contributing to the measured charge signal on the sensing electrode. It can be used to determine the imaging ability of a CI probe. It is found in previous work that, there are regions in the sensing area where the change of the charge output and the change of targeting physical parameter are of opposite trends. This opposite correlation implies that the measurement sensitivity values in such regions are negative. In this work, the cause of negative sensitivity is discussed. Experiments are also designed and performed so as to verify the existence of negative sensitivity and study the factors that may affect the negative sensitivity distributions.

  1. 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. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Measuring Value in Internal Medicine Residency Training Hospitals Using Publicly Reported Measures.

    PubMed

    Schickedanz, Adam; Gupta, Reshma; Arora, Vineet M; Braddock, Clarence H

    2018-03-01

    Graduate medical education (GME) lacks measures of resident preparation for high-quality, cost-conscious practice. The authors used publicly reported teaching hospital value measures to compare internal medicine residency programs on high-value care training and to validate these measures against program director perceptions of value. Program-level value training scores were constructed using Centers for Medicare & Medicaid Services Value-Based Purchasing (VBP) Program hospital quality and cost-efficiency data. Correlations with Association of Program Directors in Internal Medicine Annual Survey high-value care training measures were examined using logistic regression. For every point increase in program-level VBP score, residency directors were more likely to agree that GME programs have a responsibility to contain health care costs (adjusted odds ratio [aOR] 1.18, P = .04), their faculty model high-value care (aOR 1.07, P = .03), and residents are prepared to make high-value medical decisions (aOR 1.07, P = .09). Publicly reported clinical data offer valid measures of GME value training.

  3. 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.

  4. Panel Absorber

    NASA Astrophysics Data System (ADS)

    MECHEL, F. P.

    2001-11-01

    A plane wave is incident on a simply supported elastic plate covering a back volume; the arrangement is surrounded by a hard baffle wall. The plate may be porous with a flow friction resistance; the back volume may be filled either with air or with a porous material. The back volume may be bulk reacting (i.e., with sound propagation parallel to the plate) or locally reacting. Since this arrangement is of some importance in room acoustics, Cremer in his book about room acoustics [1] has presented an approximate analysis. However, Cremer's analysis uses a number of assumptions which make his solution, in his own estimate, unsuited for low frequencies, where, on the other hand, the arrangement mainly is applied. This paper presents a sound field description which uses modal analysis. It is applicable not only in the far field, but also near the absorber. Further, approximate solutions are derived, based on simplifying assumptions like Cremer has used. The modal analysis solution is of interest not only as a reference for approximations but also for practical applications, because the aspect of computing time becomes more and more unimportant (the 3D-plots presented below for the sound field were evaluated with modal analysis in about 6 s).

  5. Biases in Multicenter Longitudinal PET Standardized Uptake Value Measurements1

    PubMed Central

    Doot, Robert K; Pierce, Larry A; Byrd, Darrin; Elston, Brian; Allberg, Keith C; Kinahan, Paul E

    2014-01-01

    This study investigates measurement biases in longitudinal positron-emission tomography/computed tomography (PET/CT) studies that are due to instrumentation variability including human error. Improved estimation of variability between patient scans is of particular importance for assessing response to therapy and multicenter trials. We used National Institute of Standards and Technology-traceable calibration methodology for solid germanium-68/gallium-68 (68Ge/68Ga) sources used as surrogates for fluorine-18 (18F) in radionuclide activity calibrators. One cross-calibration kit was constructed for both dose calibrators and PET scanners using the same 9-month half-life batch of 68Ge/68Ga in epoxy. Repeat measurements occurred in a local network of PET imaging sites to assess standardized uptake value (SUV) errors over time for six dose calibrators from two major manufacturers and for six PET/CT scanners from three major manufacturers. Bias in activity measures by dose calibrators ranged from -50% to 9% and was relatively stable over time except at one site that modified settings between measurements. Bias in activity concentration measures by PET scanners ranged from -27% to 13% with a median of 174 days between the six repeat scans (range, 29 to 226 days). Corresponding errors in SUV measurements ranged from -20% to 47%. SUV biases were not stable over time with longitudinal differences for individual scanners ranging from -11% to 59%. Bias in SUV measurements varied over time and between scanner sites. These results suggest that attention should be paid to PET scanner calibration for longitudinal studies and use of dose calibrator and scanner cross-calibration kits could be helpful for quality assurance and control. PMID:24772207

  6. 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

  7. Estimation of organ cumulated activities and absorbed doses on intakes of several 11C labelled radiopharmaceuticals from external measurement with thermoluminescent dosimeters.

    PubMed

    Nakamura, T; Hayashi, Y; Watabe, H; Matsumoto, M; Horikawa, T; Fujiwara, T; Ito, M; Yanai, K

    1998-02-01

    We have developed a method for obtaining the cumulated activities in organs from radionuclides, which are injected into the patient in nuclear medicine procedures, by external exposure measurement with thermoluminescent dosimeters (TLDs) which are attached to the patient's body surface close to source organs to obtain information on body-surface doses. As the surface dose is connected to the cumulated activities in source organs through radiation transmission in the human body which can be estimated with the aid of a mathematical phantom, the organ cumulated activities can be obtained by the inverse transform method. The accuracy of this method was investigated by using a water phantom in which several gamma-ray volume sources of known activity were placed to simulate source organs. We then estimated by external measurements the organ cumulated activities and absorbed doses in subjects to whom the radiopharmaceuticals 11C-labelled Doxepin, 11C-labelled YM09151-2 and 11C-labelled Benzotropin were administered in clinical nuclear medicine procedures. The cumulated activities in the brain obtained with TLDs for Doxepin and YM09151-2 are 63.6 +/- 6.2 and 32.1 +/- 12.0 kBq h MBq-1 respectively, which are compared with the respective values of 33.3 +/- 9.9 and 23.9 +/- 6.2 kBq h MBq-1 with direct PET (positron emission tomography) measurements. The agreement between the two methods is within a factor of two. The effective doses of Doxepin, YM09151-2 and Benzotropin are determined as 6.92 x 10(-3), 7.08 x 10(-3) and 7.65 x 10(-3) mSv MBq-1 respectively with the TLD method. This method has great advantages, in that cumulated activities in several organs can be obtained easily with a single procedure, and the measurements of body surface doses are performed simultaneously with the nuclear medicine procedure, as TLDs are too small to interfere with other medical measurements.

  8. Measuring Success in Health Care Value-Based Purchasing Programs

    PubMed Central

    Damberg, Cheryl L.; Sorbero, Melony E.; Lovejoy, Susan L.; Martsolf, Grant R.; Raaen, Laura; Mandel, Daniel

    2014-01-01

    Abstract Value-based purchasing (VBP) refers to a broad set of performance-based payment strategies that link financial incentives to health care providers' performance on a set of defined measures in an effort to achieve better value. The U.S. Department of Health and Human Services is advancing the implementation of VBP across an array of health care settings in the Medicare program in response to requirements in the 2010 Patient Protection and Affordable Care Act, and policymakers are grappling with many decisions about how best to design and implement VBP programs so that they are successful in achieving stated goals. This article summarizes the current state of knowledge about VBP based on a review of the published literature, a review of publicly available documentation from VBP programs, and discussions with an expert panel composed of VBP program sponsors, health care providers and health systems, and academic researchers with VBP evaluation expertise. Three types of VBP models were the focus of the review: (1) pay-for-performance programs, (2) accountable care organizations, and (3) bundled payment programs. The authors report on VBP program goals and what constitutes success; the evidence on the impact of these programs; factors that characterize high– and low–performing providers in VBP programs; the measures, incentive structures, and benchmarks used by VBP programs; evidence on spillover effects and unintended consequences; and gaps in the knowledge base. PMID:28083347

  9. Measuring the value of accurate link prediction for network seeding.

    PubMed

    Wei, Yijin; Spencer, Gwen

    2017-01-01

    The influence-maximization literature seeks small sets of individuals whose structural placement in the social network can drive large cascades of behavior. Optimization efforts to find the best seed set often assume perfect knowledge of the network topology. Unfortunately, social network links are rarely known in an exact way. When do seeding strategies based on less-than-accurate link prediction provide valuable insight? We introduce optimized-against-a-sample ([Formula: see text]) performance to measure the value of optimizing seeding based on a noisy observation of a network. Our computational study investigates [Formula: see text] under several threshold-spread models in synthetic and real-world networks. Our focus is on measuring the value of imprecise link information. The level of investment in link prediction that is strategic appears to depend closely on spread model: in some parameter ranges investments in improving link prediction can pay substantial premiums in cascade size. For other ranges, such investments would be wasted. Several trends were remarkably consistent across topologies.

  10. Evaluating Frameworks That Provide Value Measures for Health Care Interventions.

    PubMed

    Mandelblatt, Jeanne S; Ramsey, Scott D; Lieu, Tracy A; Phelps, Charles E

    2017-02-01

    The recent acceleration of scientific discovery has led to greater choices in health care. New technologies, diagnostic tests, and pharmaceuticals have widely varying impact on patients and populations in terms of benefits, toxicities, and costs, stimulating a resurgence of interest in the creation of frameworks intended to measure value in health. Many of these are offered by providers and/or advocacy organizations with expertise and interest in specific diseases (e.g., cancer and heart disease). To help assess the utility of and the potential biases embedded in these frameworks, we created an evaluation taxonomy with seven basic components: 1) define the purpose; 2) detail the conceptual approach, including perspectives, methods for obtaining preferences of decision makers (e.g., patients), and ability to incorporate multiple dimensions of value; 3) discuss inclusions and exclusions of elements included in the framework, and whether the framework assumes clinical intervention or offers alternatives such as palliative care or watchful waiting; 4) evaluate data sources and their scientific validity; 5) assess the intervention's effect on total costs of treating a defined population; 6) analyze how uncertainty is incorporated; and 7) illuminate possible conflicts of interest among those creating the framework. We apply the taxonomy to four representative value frameworks recently published by professional organizations focused on treatment of cancer and heart disease and on vaccine use. We conclude that each of these efforts has strengths and weaknesses when evaluated using our taxonomy, and suggest pathways to enhance the utility of value-assessing frameworks for policy and clinical decision making. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  11. 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

  12. 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.

  13. Calibration of GafChromic EBT3 for absorbed dose measurements in 5 MeV proton beam and (60)Co γ-rays.

    PubMed

    Vadrucci, M; Esposito, G; Ronsivalle, C; Cherubini, R; Marracino, F; Montereali, R M; Picardi, L; Piccinini, M; Pimpinella, M; Vincenti, M A; De Angelis, C

    2015-08-01

    To study EBT3 GafChromic film in low-energy protons, and for comparison purposes, in a reference (60)Co beam in order to use it as a calibrated dosimetry system in the proton irradiation facility under construction within the framework of the Oncological Therapy with Protons (TOP)-Intensity Modulated Proton Linear Accelerator for RadioTherapy (IMPLART) Project at ENEA-Frascati, Italy. EBT3 film samples were irradiated at the Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali di Legnaro, Italy, with a 5 MeV proton beam generated by a 7 MV Van de Graaff CN accelerator. The nominal dose rates used were 2.1 Gy/min and 40 Gy/min. The delivered dose was determined by measuring the particle fluence and the energy spectrum in air with silicon surface barrier detector monitors. A preliminary study of the EBT3 film beam quality dependence in low-energy protons was conducted by passively degrading the beam energy. EBT3 films were also irradiated at ENEA-National Institute of Ionizing Radiation Metrology with gamma radiation produced by a (60)Co source characterized by an absorbed dose to water rate of 0.26 Gy/min as measured by a calibrated Farmer type ionization chamber. EBT3 film calibration curves were determined by means of a set of 40 film pieces irradiated to various doses ranging from 0.5 Gy to 30 Gy absorbed dose to water. An EPSON Expression 11000XL color scanner in transmission mode was used for film analysis. Scanner response stability, intrafilm uniformity, and interfilm reproducibility were verified. Optical absorption spectra measurements were performed on unirradiated and irradiated EBT3 films to choose the most sensitive color channel to the dose range used. EBT3 GafChromic films show an under response up to about 33% for low-energy protons with respect to (60)Co gamma radiation, which is consistent with the linear energy transfer dependence already observed with higher energy protons, and a negligible dose-rate dependence in the 2-40 Gy/min range

  14. The Bungee Jumper: A Comparison of Predicted and Measured Values

    NASA Astrophysics Data System (ADS)

    Biezeveld, Hubert

    2003-04-01

    The greater-than-g acceleration of a bungee jumper discussed in a previous article in this journal by Kagan and Kott led to many lively discussions among Dutch physics teachers. These inspired me to look for an inexpensive experimental setup, suitable for use in a high school physics class, that can be used to confirm that indeed the acceleration is greater than g. In this paper I describe an exercise to compare the predicted and the measured graphs for the displacement y(t) of the jumper and the force Fb(t) exerted by the bungee on the bridge to which it is fastened. In my apparatus, the "bungee" consists of a light chain and the "jumper" is a small piece of brass. Data collection and the calculation of predicted values were carried out using Coach.2 The analysis reliably leads to the conclusion that the acceleration of the falling jumper does indeed exceed g.

  15. Protocol for fermionic positive-operator-valued measures

    NASA Astrophysics Data System (ADS)

    Arvidsson-Shukur, D. R. M.; Lepage, H. V.; Owen, E. T.; Ferrus, T.; Barnes, C. H. W.

    2017-11-01

    In this paper we present a protocol for the implementation of a positive-operator-valued measure (POVM) on massive fermionic qubits. We present methods for implementing nondispersive qubit transport, spin rotations, and spin polarizing beam-splitter operations. Our scheme attains linear opticslike control of the spatial extent of the qubits by considering ground-state electrons trapped in the minima of surface acoustic waves in semiconductor heterostructures. Furthermore, we numerically simulate a high-fidelity POVM that carries out Procrustean entanglement distillation in the framework of our scheme, using experimentally realistic potentials. Our protocol can be applied not only to pure ensembles with particle pairs of known identical entanglement, but also to realistic ensembles of particle pairs with a distribution of entanglement entropies. This paper provides an experimentally realizable design for future quantum technologies.

  16. Measuring the economic value of wildlife: a caution

    Treesearch

    T. H. Stevens

    1992-01-01

    Wildlife values appear to be very sensitive to whether species are evaluated separately or together, and value estimates often seem inconsistent with neoclassical economic theory. Wildlife value estimates must therefore be used with caution. Additional research about the nature of individual value structures for wildlife is needed.

  17. The Study and Measurement of Values and Attitudes.

    ERIC Educational Resources Information Center

    Kerlinger, Fred N.

    The author defines values, attitudes, and beliefs according to their relation to referents. A referent is a construct standing for a set or category of social objects, ideas, or behaviors that is the focus of an attitude. Attitudes and values are belief systems. Beliefs are enduring cognitions about referents; beliefs reflect the value and…

  18. Wave Absorber with Fine Weatherability for Improving ETC Environment

    NASA Astrophysics Data System (ADS)

    Miura, Yu; Matsumoto, Kouta; Okada, Osamu; Hashimoto, Osamu

    Wave absorber of rubber sheet containing natural rubber and EPDM is designed, fabricated and measured for improving ETC environment. As a result, proposed absorption material has fine weatherability and wave absorption satisfied with ETC standard can be realized theoretically before and after the weatherability test if the thickness of absorber is fabricated at the ranging from 2.26mm to 2.52mm. Moreover, absorber sheet sample based on theoretical values is fabricated and are measured. As a result, 20dB or more is also confirmed at the incident angle ranging from 5 to 55 degrees experimentally. Therefore, the wave absorber with fine weatherability being satisfied with ETC standard can be realized.

  19. 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

  20. 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

    2016-02-01

    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.

  1. Metasurface Broadband Solar Absorber

    DOE PAGES

    Azad, Abul K.; Kort-Kamp, Wilton J. M.; Sykora, Milan; ...

    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

  2. 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…

  3. The Measurement of Values: Effects of Different Assessment Procedures

    ERIC Educational Resources Information Center

    Feather, N. T.

    1973-01-01

    Rating and pair-comparison procedures for assessing the importance of terminal and instrumental values were compared with the standard ranking procedure developed by Rokeach. Effects of order of presentation of of the value sets were also investigated. Neither procedure nor order had replicable effect though some sex differences were apparent. (TO)

  4. 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…

  5. Measuring value for low-acuity care across settings.

    PubMed

    Morgan, Sofie Rahman; Smith, Meaghan A; Pitts, Stephen R; Shesser, Robert; Uscher-Pines, Lori; Ward, Michael J; Pines, Jesse M

    2012-09-01

    Increasing healthcare costs have created an emphasis on improving value, defined as how invested time, money, and resources improve health. The role of emergency departments (EDs) within value-driven health systems is still undetermined. Often questioned is the value of an ED visit for conditions that could be reasonably treated elsewhere such as office-based, urgent, and retail clinics. This paper presents a conceptual approach to assess the value of these low-acuity visits. It adapts an existing analytic model to highlight specific factors that impact key stakeholders' (patients, insurers, and society) assessments of the value of ED-based care compared with care in alternative settings. These factors are presented in 3 equations, 1 for each stakeholder, emphasizing how tangible and intangible benefits of care weigh against direct and indirect costs and how each perspective influences value. Aligning value among groups could allow stakeholders to influence each other and could guide rational change in the delivery of acute medical care for low-acuity conditions.

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

    SciTech Connect

    Johnson, Timothy J.; Bernacki, Bruce E.; Redding, Rebecca L.

    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 diffusemore » 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.« less

  7. Comparison of 3D ion velocity distribution measurements and models in the vicinity of an absorbing boundary oriented obliquely to a magnetic field

    NASA Astrophysics Data System (ADS)

    Henriquez, Miguel F.; Thompson, Derek S.; Kenily, Shane; Khaziev, Rinat; Good, Timothy N.; McIlvain, Julianne; Siddiqui, M. Umair; Curreli, Davide; Scime, Earl E.

    2016-10-01

    Understanding particle distributions in plasma boundary regions is critical to predicting plasma-surface interactions. Ions in the presheath exhibit complex behavior because of collisions and due to the presence of boundary-localized electric fields. Complete understanding of particle dynamics is necessary for understanding the critical problems of tokamak wall loading and Hall thruster channel wall erosion. We report measurements of 3D argon ion velocity distribution functions (IVDFs) in the vicinity of an absorbing boundary oriented obliquely to a background magnetic field. Measurements were obtained via argon ion laser induced fluorescence throughout a spatial volume upstream of the boundary. These distribution functions reveal kinetic details that provide a point-to-point check on particle-in-cell and 1D3V Boltzmann simulations. We present the results of this comparison and discuss some implications for plasma boundary interaction physics.

  8. Measuring the value of older people's production: a diary study

    PubMed Central

    2012-01-01

    Background The productive capacity of retired people is usually not valued. However, some retirees produce much more than we might expect. This diary-based study identifies the activities of older people, and suggests some value mechanisms. One question raised is whether it is possible to scale up this diary study into a larger representative study. Methods Diaries kept for one week were collected among 23 older people in the north of Sweden. The texts were analysed with a grounded theory approach; an interplay between ideas and empirical data. Results Some productive activities of older people must be valued as the opportunity cost of time or according to the market value, and others must be valued with the replacement cost. In order to make the choice between these methods, it is important to consider the societal entitlement. When there is no societal entitlement, the first or second method must be used; and when it exists, the third must be used. Conclusions An explicit investigation of the content of the entitlement is needed to justify the choice of valuation method for each activity. In a questionnaire addressing older people's production, each question must be adjusted to the type of production. In order to fully understand this production, it is important to consider the degree of free choice to conduct an activity, as well as health-related quality of life. PMID:22230745

  9. 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.

  10. Measuring the Economic Value of Pre-MBA Work Experience

    ERIC Educational Resources Information Center

    Yeaple, Ronald N.; Johnston, Mark W.; Whittingham, Keith L.

    2010-01-01

    Pre-MBA work experience is required for admission to many graduate schools of business. In the present study, MBA graduates with a wide range of pre-MBA work experience were surveyed to assess the economic value of such work experience. No evidence was found of a systematic financial advantage to students from working for several years before…

  11. A tool to measure nurse efficiency and value.

    PubMed

    Landry, M T; Landry, H T; Hebert, W

    2001-07-01

    Home care nurses who have multiple roles can increase their value by validating their contributions and work efficiency. This article presents a method for tracking nurse efficiency for those who are paid on an hourly basis, and provides a mechanism to document their contributions to the home care agency.

  12. 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…

  13. 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…

  14. Measuring the Value Added of Management: A Knowledge Value Added Approach

    DTIC Science & Technology

    2006-12-31

    Dark Matter ” ................................................................3 Difficult-to-track Dark Matter Outputs .................................................5 Computing Metaphor..........................................................................6 Dark Matter Correlates with Market Performance ..............................8 Outputs of Dark Matter .......................................................................9 Operationalizing: The Measurement of Dark

  15. Measuring Virtual Simulations Value in Training Exercises - USMC Use Case

    DTIC Science & Technology

    2015-12-04

    and cost avoidance and Capt Jonathan Richardson, PM TRASYS, who was the primary author for the After-Action Documentation and Analysis Report ...REFERENCES Cermak J. & McGurk M. (2010, July). Putting a Value On Training. McKinsey Quarterly. Retrieved June 10, 2015 from http://www.mckinsey.com...www.hqmc.marines.mil/Portals/142/Docs/2015CPG_Color.pdf Gordon, S. & Cooley, T. (2013) Phase One Final Report : Cost Avoidance Study of USMC Simulation

  16. 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.

  17. 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 amore » 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.« less

  18. Measure-valued solutions to nonlocal transport equations on networks

    NASA Astrophysics Data System (ADS)

    Camilli, Fabio; De Maio, Raul; Tosin, Andrea

    2018-06-01

    Aiming to describe traffic flow on road networks with long-range driver interactions, we study a nonlinear transport equation defined on an oriented network where the velocity field depends not only on the state variable but also on the distribution of the population. We prove existence, uniqueness and continuous dependence results of the solution intended in a suitable measure-theoretic sense. We also provide a representation formula in terms of the push-forward of the initial and boundary data along the network and discuss an explicit example of nonlocal velocity field fitting our framework.

  19. MAX-DOAS observations from ground, ship, and research aircraft: maximizing signal-to-noise to measure 'weak' absorbers

    NASA Astrophysics Data System (ADS)

    Volkamer, Rainer; Coburn, Sean; Dix, Barbara; Sinreich, Roman

    2009-08-01

    Multi AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instruments, as solar straylight satellites, require an accurate characterization and elimination of Fraunhofer lines from solar straylight spectra to measure the atmospheric column abundance of reactive gases that destroy toxic and heat trapping ozone and form climate cooling aerosols, like glyoxal (CHOCHO), iodine oxide (IO), or bromine oxide (BrO). The currently achievable noise levels with state-of-the-art DOAS instruments are limited to δ'DL ~ 10-4 (noise equivalent differential optical density, δ') further noise reductions are typically not straightforward, and the reason for this barrier is not well understood. Here we demonstrate that the nonlinearity of state-of-the-art CCD detectors poses a limitation to accurately characterize Fraunhofer lines; the incomplete elimination of Fraunhofer lines is found to cause residual structures of δ' ~ 10-4, and only partially accounted by fitting of an "offset" spectrum. We have developed a novel software tool, the CU Data Acquisition Code that overcomes this barrier by actively controlling the CCD saturation level, and demonstrates that δ'DL on the order of 10-5 are possible without apparent limitations from the presence of Fraunhofer lines. The software also implements active control of the elevation angle (angle with respect to the horizon) by means of a Motion Compensation System for use with mobile MAX-DOAS deployments from ships and aircraft. Finally, a novel approach to convert slant column densities into line-of-sight averaged concentrations is discussed.

  20. 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

  1. 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.; Zhu, G.

    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 ofmore » {>=}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.« less

  2. 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.

  3. 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.

  4. 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 dialect,…

  5. 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,…

  6. 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…

  7. Measuring the value of endoscopic retrograde cholangiopancreatography activity: an opportunity to stratify endoscopists on the basis of their value.

    PubMed

    Parihar, Vikrant; Moran, Carthage; Maheshwari, Pardeep; Cheriyan, Danny; O'Toole, Aoibhlinn; Murray, Frank; Patchett, Stephen E; Harewood, Gavin C

    2018-07-01

    As finite healthcare resources come under pressure, the value of physician activity is assuming increasing importance. The value in healthcare can be defined as patient health outcomes achieved per monetary unit spent. Even though some attempts have been made to quantify the value of clinician activity, there is little in the medical literature describing the importance of endoscopists' activity. This study aimed to characterize the value of endoscopic retrograde cholangiopancreatography (ERCP) performance of five gastroenterologists. We carried out a retrospective-prospective cohort study using the databases of patients undergoing ERCP between September 2014 and March 2017. We collected data from 1070 patients who underwent ERCP comparing value among the ERCPists at index ERCP. Procedure value was calculated using the formula Q/(T/C), where Q is the quality of procedure, T is the duration of procedure and C is the adjusted for complexity level. Quality and complexity were derived on a 1-4 Likert scale on the basis of American Society for Gastrointestinal Endoscopy criteria; time was recorded (in min) from intubation to extubation. Endoscopist time calculated from procedure time was considered a surrogate marker of cost as individual components of procedure cost were not itemized. In total, 590 procedures were analysed: 465 retrospectively over 24 months and 125 prospectively over 6 months. There was a 32% variation in the value of endoscopist activity in a more substantial retrospective cohort, with an even more considerable 73% variation in a smaller prospective arm. In an analysis of greater than 1000 ERCPs by a small cohort of experienced ERCPists, there was a wide variation in the value of endoscopist activity. Although the precision of estimating procedural costs needs further refinement, these findings show the ability to stratify ERCPists on the basis of the value their activity. As healthcare costs are scrutinized more closely, such value measurements are

  8. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Absorbance enhancement in microplate wells for improved-sensitivity biosensors.

    PubMed

    Suárez, Guillaume; Santschi, Christian; Plateel, Gregory; Martin, Olivier J F; Riediker, Michael

    2014-06-15

    A generic optical biosensing strategy was developed that relies on the absorbance enhancement phenomenon occurring in a multiple scattering matrix. Experimentally, inserts made of glass fiber membrane were placed into microplate wells in order to significantly lengthen the trajectory of the incident light through the sample and therefore increase the corresponding absorbance. Enhancement factor was calculated by comparing the absorbance values measured for a given amount of dye with and without the absorbance-enhancing inserts in the wells. Moreover, the dilution of dye in solutions with different refractive indices (RI) clearly revealed that the enhancement factor increased with the ΔRI between the membrane and the surrounding medium, reaching a maximum value (EF>25) when the membranes were dried. On this basis, two H2O2-biosensing systems were developed based on the biofunctionalization of the glass fiber inserts either with cytochrome c or horseradish peroxidase (HRP) and the analytical performances were systematically compared with the corresponding bioassay in solution. The efficiency of the absorbance-enhancement approach was particularly clear in the case of the cytochrome c-based biosensor with a sensitivity gain of 40 folds and wider dynamic range. Therefore, the developed strategy represents a promising way to convert standard colorimetric bioassays into optical biosensors with improved sensitivity. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. 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.

  11. Dosimetry for nonuniform activity distributions: a method for the calculation of 3D absorbed-dose distribution without the use of voxel S-values, point kernels, or Monte Carlo simulations.

    PubMed

    Traino, A C; Marcatili, S; Avigo, C; Sollini, M; Erba, P A; Mariani, G

    2013-04-01

    Nonuniform activity within the target lesions and the critical organs constitutes an important limitation for dosimetric estimates in patients treated with tumor-seeking radiopharmaceuticals. The tumor control probability and the normal tissue complication probability are affected by the distribution of the radionuclide in the treated organ/tissue. In this paper, a straightforward method for calculating the absorbed dose at the voxel level is described. This new method takes into account a nonuniform activity distribution in the target/organ. The new method is based on the macroscopic S-values (i.e., the S-values calculated for the various organs, as defined in the MIRD approach), on the definition of the number of voxels, and on the raw-count 3D array, corrected for attenuation, scatter, and collimator resolution, in the lesion/organ considered. Starting from these parameters, the only mathematical operation required is to multiply the 3D array by a scalar value, thus avoiding all the complex operations involving the 3D arrays. A comparison with the MIRD approach, fully described in the MIRD Pamphlet No. 17, using S-values at the voxel level, showed a good agreement between the two methods for (131)I and for (90)Y. Voxel dosimetry is becoming more and more important when performing therapy with tumor-seeking radiopharmaceuticals. The method presented here does not require calculating the S-values at the voxel level, and thus bypasses the mathematical problems linked to the convolution of 3D arrays and to the voxel size. In the paper, the results obtained with this new simplified method as well as the possibility of using it for other radionuclides commonly employed in therapy are discussed. The possibility of using the correct density value of the tissue/organs involved is also discussed.

  12. 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.

  13. Methods for absorbing neutrons

    DOEpatents

    Guillen, Donna P [Idaho Falls, ID; Longhurst, Glen R [Idaho Falls, ID; Porter, Douglas L [Idaho Falls, ID; Parry, James R [Idaho Falls, ID

    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.

  14. Measuring Value-at-Risk and Expected Shortfall of crude oil portfolio using extreme value theory and vine copula

    NASA Astrophysics Data System (ADS)

    Yu, Wenhua; Yang, Kun; Wei, Yu; Lei, Likun

    2018-01-01

    Volatilities of crude oil price have important impacts on the steady and sustainable development of world real economy. Thus it is of great academic and practical significance to model and measure the volatility and risk of crude oil markets accurately. This paper aims to measure the Value-at-Risk (VaR) and Expected Shortfall (ES) of a portfolio consists of four crude oil assets by using GARCH-type models, extreme value theory (EVT) and vine copulas. The backtesting results show that the combination of GARCH-type-EVT models and vine copula methods can produce accurate risk measures of the oil portfolio. Mixed R-vine copula is more flexible and superior to other vine copulas. Different GARCH-type models, which can depict the long-memory and/or leverage effect of oil price volatilities, however offer similar marginal distributions of the oil returns.

  15. Complex Fuzzy Set-Valued Complex Fuzzy Measures and Their Properties

    PubMed Central

    Ma, Shengquan; Li, Shenggang

    2014-01-01

    Let F*(K) be the set of all fuzzy complex numbers. In this paper some classical and measure-theoretical notions are extended to the case of complex fuzzy sets. They are fuzzy complex number-valued distance on F*(K), fuzzy complex number-valued measure on F*(K), and some related notions, such as null-additivity, pseudo-null-additivity, null-subtraction, pseudo-null-subtraction, autocontionuous from above, autocontionuous from below, and autocontinuity of the defined fuzzy complex number-valued measures. Properties of fuzzy complex number-valued measures are studied in detail. PMID:25093202

  16. Experimental and simulated study of a composite structure metamaterial absorber

    NASA Astrophysics Data System (ADS)

    Li, Shengyong; Ai, Xiaochuan; Wu, Ronghua; Chen, Jiajun

    2017-11-01

    In this paper, a high performance metamaterial absorber is designed and experimental studied. Measured results indicate that a perfect absorption band and a short-wavelength absorption peak are achieved in the near-infrared spectrum. Current strength distributions reveal that the absorption band is excited by the cavity resonance. And electric field distributions show that the short-wavelength absorption peak is excited by the horizontal coupled of localized surface plasmon (LSP) modes near hole edges. On the one hand, the absorption property of the measured metamaterial absorber can be enhanced through optimizing the structural parameters (a, w, and H). On the other hand, the absorption property is sensitive to the change of refractive index of environmental medias. A sensing scheme is proposed for refractive index detecting based on the figure of merit (FOM) value. Measured results indicate that the proposed sensing scheme can achieve high FOM value with different environmental medias (water, glucose solution).

  17. 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.

  18. Measuring the value of nonwage employee benefits: building a model of the relation between benefit satisfaction and value.

    PubMed

    Weathington, Bart L; Jones, Allan P

    2006-11-01

    Researchers have commonly assumed benefits that employees view as more valuable have a greater influence on their attitudes and behaviors. Researchers have used 2 common methods to measure benefit value: attaching a monetary value to benefits and using self-reports of benefit importance. The present authors propose that the 2 approaches are conceptually distinct and have different implications. They use a social exchange perspective to justify this distinction and integrate both approaches and benefit satisfaction into a more comprehensive model of benefit perception. Results suggest that both measures have practical applications depending on the nature of the exchange relationship between the organization and employees. However, this relationship depends on the specific benefit and on employee satisfaction with that benefit. Some benefits lend themselves to a monetary estimate, whereas others lend themselves more to a nonmonetary valuation.

  19. 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.

  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. Evaluation of effective energy for QA and QC: measurement of half-value layer using radiochromic film density.

    PubMed

    Gotanda, T; Katsuda, T; Gotanda, R; Tabuchi, A; Yamamoto, K; Kuwano, T; Yatake, H; Takeda, Y

    2009-03-01

    The effective energy of diagnostic X-rays is important for quality assurance (QA) and quality control (QC). However, the half-value layer (HVL), which is necessary to evaluate the effective energy, is not ubiquitously monitored because ionization-chamber dosimetry is time-consuming and complicated. To verify the applicability of GAFCHROMIC XR type R (GAF-R) film for HVL measurement as an alternative to monitoring with an ionization chamber, a single-strip method for measuring the HVL has been evaluated. Calibration curves of absorbed dose versus film density were generated using this single-strip method with GAF-R film, and the coefficient of determination (r2) of the straight-line approximation was evaluated. The HVLs (effective energies) estimated using the GAF-R film and an ionization chamber were compared. The coefficient of determination (r2) of the straight-line approximation obtained with the GAF-R film was more than 0.99. The effective energies (HVLs) evaluated using the GAF-R film and the ionization chamber were 43.25 keV (5.10 mm) and 39.86 keV (4.45 mm), respectively. The difference in the effective energies determined by the two methods was thus 8.5%. These results suggest that GAF-R might be used to evaluate the effective energy from the film-density growth without the need for ionization-chamber measurements.

  2. Measuring the Value of Placements to Employers: A Cost-Benefit Approach

    ERIC Educational Resources Information Center

    Wond, Tracey; Rambukwella, Shan

    2018-01-01

    This article explores the concept and measurement of placement value, underexplored in theory and practice to date. The article makes a theoretical contribution to the placement value discourse by examining and articulating the placement value concept. It also offers a practical contribution by exploring a piloted tool to evaluate employer…

  3. Acoustic Properties of Absorbent Asphalts

    NASA Astrophysics Data System (ADS)

    Trematerra, Amelia; Lombardi, Ilaria

    2017-08-01

    Road traffic is one of the greater cause of noise pollution in urban centers; a prolonged exposure to this source of noise disturbs populations subjected to it. In this paper is reported a study on the absorbent coefficients of asphalt. The acoustic measurements are carried out with a impedance tube (tube of Kundt). The sample are measured in three conditions: with dry material (traditional), “wet” asphalt and “dirty” asphalt.

  4. The Development and Validation of Brief and Ultrabrief Measures of Values.

    PubMed

    Sandy, Carson J; Gosling, Samuel D; Schwartz, Shalom H; Koelkebeck, Tim

    2017-01-01

    Values are a central personality construct and the importance of studying them has been well established. To encourage researchers to integrate measures of values into their studies, brief and ultrabrief instruments were developed to recapture the 10 values measured by the 40-item Portrait Values Questionnaire (PVQ; Schwartz, 2003 ). Rigorous psychometric procedures based on separate derivation (N = 38,049) and evaluation (N = 29,143) samples yielded 10- and 20-item measures of values, which proved to be successful at capturing the patterns and magnitude of correlations associated with the original PVQ. These instruments should be useful to researchers who would like to incorporate a values scale into their study but do not have the space to administer a longer measure.

  5. What's the Difference? A Model for Measuring the Value Added by Higher Education in Australia

    ERIC Educational Resources Information Center

    Coates, Hamish

    2009-01-01

    Measures of student learning are playing an increasingly significant role in determining the quality and productivity of higher education. This paper evaluates approaches for estimating the value added by university education, and proposes a methodology for use by institutions and systems. The paper argues that value-added measures of learning are…

  6. 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.

  7. Validating Fricke dosimetry for the measurement of absorbed dose to water for HDR 192Ir brachytherapy: a comparison between primary standards of the LCR, Brazil, and the NRC, Canada.

    PubMed

    Salata, Camila; David, Mariano Gazineu; de Almeida, Carlos Eduardo; El Gamal, Islam; Cojocaru, Claudiu; Mainegra-Hing, Ernesto; McEwen, Malcom

    2018-04-05

    Two Fricke-based absorbed dose to water standards for HDR Ir-192 dosimetry, developed independently by the LCR in Brazil and the NRC in Canada have been compared. The agreement in the determination of the dose rate from a HDR Ir-192 source at 1 cm in a water phantom was found to be within the k  =  1 combined measurement uncertainties of the two standards: D NRC /D LCR   =  1.011, standard uncertainty  =  2.2%. The dose-based standards also agreed within the uncertainties with the manufacturer's stated dose rate value, which is traceable to a national standard of air kerma. A number of possible influence quantities were investigated, including the specific method for producing the ferrous-sulphate Fricke solution, the geometry of the holder, and the Monte Carlo code used to determine correction factors. The comparison highlighted the lack of data on the determination of G(Fe 3+ ) in this energy range and the possibilities for further development of the holders used to contain the Fricke solution. The comparison also confirmed the suitability of Fricke dosimetry for Ir-192 primary standard dose rate determinations at therapy dose levels.

  8. Validating Fricke dosimetry for the measurement of absorbed dose to water for HDR 192Ir brachytherapy: a comparison between primary standards of the LCR, Brazil, and the NRC, Canada

    NASA Astrophysics Data System (ADS)

    Salata, Camila; Gazineu David, Mariano; de Almeida, Carlos Eduardo; El Gamal, Islam; Cojocaru, Claudiu; Mainegra-Hing, Ernesto; McEwen, Malcom

    2018-04-01

    Two Fricke-based absorbed dose to water standards for HDR Ir-192 dosimetry, developed independently by the LCR in Brazil and the NRC in Canada have been compared. The agreement in the determination of the dose rate from a HDR Ir-192 source at 1 cm in a water phantom was found to be within the k  =  1 combined measurement uncertainties of the two standards: D NRC/D LCR  =  1.011, standard uncertainty  =  2.2%. The dose-based standards also agreed within the uncertainties with the manufacturer’s stated dose rate value, which is traceable to a national standard of air kerma. A number of possible influence quantities were investigated, including the specific method for producing the ferrous-sulphate Fricke solution, the geometry of the holder, and the Monte Carlo code used to determine correction factors. The comparison highlighted the lack of data on the determination of G(Fe3+) in this energy range and the possibilities for further development of the holders used to contain the Fricke solution. The comparison also confirmed the suitability of Fricke dosimetry for Ir-192 primary standard dose rate determinations at therapy dose levels.

  9. 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.

  10. Direct quantum process tomography via measuring sequential weak values of incompatible observables.

    PubMed

    Kim, Yosep; Kim, Yong-Su; Lee, Sang-Yun; Han, Sang-Wook; Moon, Sung; Kim, Yoon-Ho; Cho, Young-Wook

    2018-01-15

    The weak value concept has enabled fundamental studies of quantum measurement and, recently, found potential applications in quantum and classical metrology. However, most weak value experiments reported to date do not require quantum mechanical descriptions, as they only exploit the classical wave nature of the physical systems. In this work, we demonstrate measurement of the sequential weak value of two incompatible observables by making use of two-photon quantum interference so that the results can only be explained quantum physically. We then demonstrate that the sequential weak value measurement can be used to perform direct quantum process tomography of a qubit channel. Our work not only demonstrates the quantum nature of weak values but also presents potential new applications of weak values in analyzing quantum channels and operations.

  11. Development and Preliminary Validation of a New Measure of Values in Scientific Work.

    PubMed

    English, Tammy; Antes, Alison L; Baldwin, Kari A; DuBois, James M

    2018-04-01

    In this paper we describe the development and initial psychometric evaluation of a new measure, the values in scientific work (VSW). This scale assesses the level of importance that investigators attach to different VSW. It taps a broad range of intrinsic, extrinsic, and social values that motivate the work of scientists, including values specific to scientific work (e.g., truth and integrity) and more classic work values (e.g., security and prestige) in the context of science. Notably, the values represented in this scale are relevant to scientists regardless of their career stage and research focus. We administered the VSW and a measure of global values to 203 NIH-funded investigators. Exploratory factor analyses suggest the delineation of eight VSW, including autonomy, research ethics, social impact, income, collaboration, innovation and growth, conserving relationships, and job security. These VSW showed predictable and distinct associations with global values. Implications of these findings for work on research integrity and scientific misconduct are discussed.

  12. "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.

  13. 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

  14. 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.

  15. Workshop: Using Contingent Valuation to Measure Non-Market Values (1994)

    EPA Pesticide Factsheets

    Workshop co-hosted by USEPA and Dept of Energy on using contingent valuation to measure non-market values for improvement in health and the environment. Includes transcripts of presentations and discussion by attendees, later published as a book.

  16. Stability of Teacher Value-Added Rankings across Measurement Model and Scaling Conditions

    ERIC Educational Resources Information Center

    Hawley, Leslie R.; Bovaird, James A.; Wu, ChaoRong

    2017-01-01

    Value-added assessment methods have been criticized by researchers and policy makers for a number of reasons. One issue includes the sensitivity of model results across different outcome measures. This study examined the utility of incorporating multivariate latent variable approaches within a traditional value-added framework. We evaluated the…

  17. 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.

  18. 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.

  19. Radiation dosimetry in cell biology: comparison of calculated and measured absorbed dose for a range of culture vessels and clinical beam qualities.

    PubMed

    Claridge Mackonis, Elizabeth; Hammond, Lauren; Esteves, Ana I S; Suchowerska, Natalka

    2018-02-01

    Cell culture studies are frequently used to evaluate the effects of cancer treatments such as radiotherapy, hormone therapy, chemotherapy, nanoparticle enhancement, and to determine any synergies between the treatments. To achieve valid results, the absorbed dose of each therapy needs to be well known and controlled. In this study, we aim to determine the uncertainty associated with radiation exposure in different experimental conditions. We have performed an in-depth evaluation of the absorbed dose and dose distribution that would be delivered to a cell sample when cultivated in a number of the more popular designs of culture vessels. We focus on exposure to two beam types: a kilovoltage x-ray beam and a megavoltage photon beam, both of which are routinely used to treat cancer patients in the clinical environment. Our results identify large variations of up to 16% in the absorbed dose across multi-well culture plates, which if ignored in radiobiological experiments, have the potential to lead to erroneous conclusions.

  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. Comparing multistate expected damages, option price and cumulative prospect measures for valuing flood protection

    NASA Astrophysics Data System (ADS)

    Farrow, Scott; Scott, Michael

    2013-05-01

    Floods are risky events ranging from small to catastrophic. Although expected flood damages are frequently used for economic policy analysis, alternative measures such as option price (OP) and cumulative prospect value exist. The empirical magnitude of these measures whose theoretical preference is ambiguous is investigated using case study data from Baltimore City. The outcome for the base case OP measure increases mean willingness to pay over the expected damage value by about 3%, a value which is increased with greater risk aversion, reduced by increased wealth, and only slightly altered by higher limits of integration. The base measure based on cumulative prospect theory is about 46% less than expected damages with estimates declining when alternative parameters are used. The method of aggregation is shown to be important in the cumulative prospect case which can lead to an estimate up to 41% larger than expected damages. Expected damages remain a plausible and the most easily computed measure for analysts.

  2. Linking Quality and Spending to Measure Value for People with Serious Illness.

    PubMed

    Ryan, Andrew M; Rodgers, Phillip E

    2018-03-01

    Healthcare payment is rapidly evolving to reward value by measuring and paying for quality and spending performance. Rewarding value for the care of seriously ill patients presents unique challenges. To evaluate the state of current efforts to measure and reward value for the care of seriously ill patients. We performed a PubMed search of articles related to (1) measures of spending for people with serious illness and (2) linking spending and quality measures and rewarding performance for the care of people with serious illness. We limited our search to U.S.-based studies published in English between January 1, 1960, and March 31, 2017. We supplemented this search by identifying public programs and other known initiatives that linked quality and spending for the seriously ill and extracted key program elements. Our search related to linking spending and quality measures and rewarding performance for the care of people with serious illness yielded 277 articles. We identified three current public programs that currently link measures of quality and spending-or are likely to within the next few years-the Oncology Care Model; the Comprehensive End-Stage Renal Disease Model; and Home Health Value-Based Purchasing. Models that link quality and spending consist of four core components: (1) measuring quality, (2) measuring spending, (3) the payment adjustment model, and (4) the linking/incentive model. We found that current efforts to reward value for seriously ill patients are targeted for specific patient populations, do not broadly encourage the use of palliative care, and have not closely aligned quality and spending measures related to palliative care. We develop recommendations for policymakers and stakeholders about how measures of spending and quality can be balanced in value-based payment programs.

  3. Linking Quality and Spending to Measure Value for People with Serious Illness

    PubMed Central

    Rodgers, Phillip E.

    2018-01-01

    Abstract Background: Healthcare payment is rapidly evolving to reward value by measuring and paying for quality and spending performance. Rewarding value for the care of seriously ill patients presents unique challenges. Objective: To evaluate the state of current efforts to measure and reward value for the care of seriously ill patients. Design: We performed a PubMed search of articles related to (1) measures of spending for people with serious illness and (2) linking spending and quality measures and rewarding performance for the care of people with serious illness. We limited our search to U.S.-based studies published in English between January 1, 1960, and March 31, 2017. We supplemented this search by identifying public programs and other known initiatives that linked quality and spending for the seriously ill and extracted key program elements. Results: Our search related to linking spending and quality measures and rewarding performance for the care of people with serious illness yielded 277 articles. We identified three current public programs that currently link measures of quality and spending—or are likely to within the next few years—the Oncology Care Model; the Comprehensive End-Stage Renal Disease Model; and Home Health Value-Based Purchasing. Models that link quality and spending consist of four core components: (1) measuring quality, (2) measuring spending, (3) the payment adjustment model, and (4) the linking/incentive model. We found that current efforts to reward value for seriously ill patients are targeted for specific patient populations, do not broadly encourage the use of palliative care, and have not closely aligned quality and spending measures related to palliative care. Conclusions: We develop recommendations for policymakers and stakeholders about how measures of spending and quality can be balanced in value-based payment programs. PMID:29091529

  4. Mathematical values in the processing of Chinese numeral classifiers and measure words.

    PubMed

    Her, One-Soon; Chen, Ying-Chun; Yen, Nai-Shing

    2017-01-01

    A numeral classifier is required between a numeral and a noun in Chinese, which comes in two varieties, sortal classifer (C) and measural classifier (M), also known as 'classifier' and 'measure word', respectively. Cs categorize objects based on semantic attributes and Cs and Ms both denote quantity in terms of mathematical values. The aim of this study was to conduct a psycholinguistic experiment to examine whether participants process C/Ms based on their mathematical values with a semantic distance comparison task, where participants judged which of the two C/M phrases was semantically closer to the target C/M. Results showed that participants performed more accurately and faster for C/Ms with fixed values than the ones with variable values. These results demonstrated that mathematical values do play an important role in the processing of C/Ms. This study may thus shed light on the influence of the linguistic system of C/Ms on magnitude cognition.

  5. Shock absorber servicing tool

    NASA Technical Reports Server (NTRS)

    Koepler, Jack L. (Inventor); Hill, Robert L. (Inventor)

    1981-01-01

    A tool to assist in the servicing of a shock absorber wherein the shock absorber is constructed of a pair of aligned gas and liquid filled chambers. Each of the chambers is separated by a movable separator member. Maximum efficiency of the shock absorber is achieved in the locating of a precise volume of gas within the gas chamber and a precise volume of liquid within the liquid chamber. The servicing tool of this invention employs a rod which is to connect with the separator and by observation of the position of the rod with respect to the gauge body, the location of the separator is ascertained even though it is not directly observable.

  6. Mechanical energy absorber

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J. (Inventor)

    1993-01-01

    An energy absorbing system for controlling the force where a moving object engages a stationary stop and where the system utilized telescopic tubular members, energy absorbing diaphragm elements, force regulating disc springs, and a return spring to return the telescoping member to its start position after stroking is presented. The energy absorbing system has frusto-conical diaphragm elements frictionally engaging the shaft and are opposed by a force regulating set of disc springs. In principle, this force feedback mechanism serves to keep the stroking load at a reasonable level even if the friction coefficient increases greatly. This force feedback device also serves to desensitize the singular and combined effects of manufacturing tolerances, sliding surface wear, temperature changes, dynamic effects, and lubricity.

  7. Accuracy of apparent diffusion coefficient value measurement on PACS workstation: A comparative analysis.

    PubMed

    El Kady, Reem M; Choudhary, Arabinda Kumar; Tappouni, Rafel

    2011-03-01

    The purpose of this article is to evaluate the accuracy of apparent diffusion coefficient (ADC) measurements made with a PACS workstation compared with measurements made with a dedicated workstation, which is currently considered the reference standard. A retrospective review was performed in liver lesions from 79 patients using three MRI platforms. The final diagnosis was established by liver biopsy in 31 patients and by dynamic MRI and follow-up, both clinical and radiologic as indicated, in 48 patients. Each lesion that was clearly demonstrable on the ADC map was measured with a commercial dedicated postprocessing workstation and again with a PACS system. A two-sample t test was used to determine the statistically significant differences between the two ADC measurements. A total of 79 patients with 120 liver lesions were included. ADC values measured on the workstation were 0.4-4.38 × 10(-3) mm(2)/s. The ADC values measured on the PACS were 0.42-4.35 × 10(-3) mm(2)/s. The T value was -1.113, with 119 degrees of freedom, and the significance level was 0.268, which implies no significant difference between the two different measuring systems for all pathologic abnormalities and MRI scanners used. ADC values measured on a routine PACS workstation are as accurate as the values obtained on a dedicated specialized workstation. ADC value measurement on the routine PACS will save time and lead to increased utilization, which, in turn, will lead to an improved understanding of the different disease processes and their clinical management.

  8. Shock Absorbing System

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A lightweight, inexpensive shock-absorbing system, developed by Langley Research Center 20 years ago, is now in service as safety device for an automated railway at Duke University Medical Center. The transportation system travels at about 25 miles per hour, carrying patients, visitors, staff and cargo. At the end of each guideway of the system are "frangible," (breakable) tube "buffers." If a slowing car fails to make a complete stop at the terminal, it would bump and shatter the tubes, absorbing energy that might otherwise jolt the passengers or damage the vehicle.

  9. A scheme of quantum state discrimination over specified states via weak-value measurement

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Dai, Hong-Yi; Liu, Bo-Yang; Zhang, Ming

    2018-04-01

    The commonly adopted projective measurements are invalid in the specified task of quantum state discrimination when the discriminated states are superposition of planar-position basis states whose complex-number probability amplitudes have the same magnitude but different phases. Therefore we propose a corresponding scheme via weak-value measurement and examine the feasibility of this scheme. Furthermore, the role of the weak-value measurement in quantum state discrimination is analyzed and compared with one in quantum state tomography in this Letter.

  10. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. 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.

  12. 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

  13. 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.

  14. Design of a nonlinear torsional vibration absorber

    NASA Astrophysics Data System (ADS)

    Tahir, Ammaar Bin

    larger than that in the latter. A nonlinear absorber design has been proposed comprising of thin beams as elastic elements. The geometric configuration of the proposed design has been shown to provide cubic stiffness nonlinearity in torsion. The values of design variables, namely the strength of nonlinearity alpha and torsional stiffness kalpha, were obtained by optimizing dimensions and material properties of the beams for a maximum vibration energy dissipation in the nonlinear absorber. A parametric study has also been conducted to analyze the effect of the magnitude of excitation provided to the system on the performance of a nonlinear absorber. It has been shown that the nonlinear absorber turns out to be more effective in terms of energy dissipation as compared to a linear absorber with an increase in the excitation level applied to the system.

  15. Repeatability, variability and reference values of pulsed wave Doppler echocardiographic measurements in healthy Saanen goats

    PubMed Central

    2012-01-01

    Background Pulsed wave (PW) Doppler echocardiography has become a routine non invasive cardiac diagnostic tool in most species. However, evaluation of intracardiac blood flow requires reference values, which are poorly documented in goats. The aim of this study was to test the repeatability, the variability, and to establish the reference values of PW measurements in healthy adult Saanen goats. Using a standardised PW Doppler echocardiographic protocol, 10 healthy adult unsedated female Saanen goats were investigated three times at one day intervals by the same observer. Mitral, tricuspid, aortic and pulmonary flows were measured from a right parasternal view, and mitral and aortic flows were also measured from a left parasternal view. The difference between left and right side measurements and the intra-observer inter-day repeatability were tested and then the reference values of PW Doppler echocardiographic parameters in healthy adult female Saanen goats were established. Results As documented in other species, all caprine PW Doppler parameters demonstrated a poor inter-day repeatability and a moderate variability. Tricuspid and pulmonary flows were best evaluated on the right side whereas mitral and aortic flows were best obtained on the left side, and reference values are reported for healthy adult Saanen goats. Conclusions PW Doppler echocardiography allows the measurement of intracardiac blood flow indices in goats. The reference values establishment will help interpreting these indices of cardiac function in clinical cardiac cases and developing animal models for human cardiology research. PMID:23067875

  16. Shock Absorbing Helmets

    NASA Technical Reports Server (NTRS)

    1978-01-01

    This paper presents a description of helmets used by football players that offer three times the shock-absorbing capacity of earlier types. An interior padding for the helmets, composed of Temper Foam, first used by NASA's Ames Research Center in the design of aircraft seats is described.

  17. 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.

  18. Dynamic testing of airplane shock-absorbing struts

    NASA Technical Reports Server (NTRS)

    Langer, P; Thome, W

    1932-01-01

    Measurement of perpendicular impacts of a landing gear with different shock-absorbing struts against the drum testing stand. Tests were made with pneumatic shock absorbers having various degrees of damping, liquid shock absorbers, steel-spring shock absorbers and rigid struts. Falling tests and rolling tests. Maximum impact and gradual reduction of the impacts in number and time in the falling tests. Maximum impact and number of weaker impacts in rolling tests.

  19. Comparison of measurement- and proxy-based Vs30 values in California

    USGS Publications Warehouse

    Yong, Alan K.

    2016-01-01

    This study was prompted by the recent availability of a significant amount of openly accessible measured VS30 values and the desire to investigate the trend of using proxy-based models to predict VS30 in the absence of measurements. Comparisons between measured and model-based values were performed. The measured data included 503 VS30 values collected from various projects for 482 seismographic station sites in California. Six proxy-based models—employing geologic mapping, topographic slope, and terrain classification—were also considered. Included was a new terrain class model based on the Yong et al. (2012) approach but recalibrated with updated measured VS30 values. Using the measured VS30 data as the metric for performance, the predictive capabilities of the six models were determined to be statistically indistinguishable. This study also found three models that tend to underpredict VS30 at lower velocities (NEHRP Site Classes D–E) and overpredict at higher velocities (Site Classes B–C).

  20. 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

  1. Electromagnetic wave absorbing properties of amorphous carbon nanotubes.

    PubMed

    Zhao, Tingkai; Hou, Cuilin; Zhang, Hongyan; Zhu, Ruoxing; She, Shengfei; Wang, Jungao; Li, Tiehu; Liu, Zhifu; Wei, Bingqing

    2014-07-10

    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.

  2. [The prognostic value of cerebral oxygen saturation measurement for assessing prognosis after cardiopulmonary resuscitation].

    PubMed

    Inal, Mehmet Turan; Memiş, Dilek; Yıldırım, Ilker; Uğur, Hüseyin; Erkaymaz, Aysegul; Turan, F Nesrin

    Despite new improvements on cardiopulmonary resuscitation (CPR), brain damage is very often after resuscitation. To assess the prognostic value of cerebral oxygen saturation measurement (rSO 2 ) for assessing prognosis on patients after cardiopulmonary resuscitation. Retrospective analysis. We analyzed 25 post-CPR patients (12 female and 13 male). All the patients were cooled to a target temperature of 33-34°C. The Glascow Coma Scale (GCS), Corneal Reflexes (CR), Pupillary Reflexes (PR), arterial Base Excess (BE) and rSO 2 measurements were taken on admission. The rewarming GCS, CR, PR, BE and rSO 2 measurements were made after the patient's temperature reached 36°C. In survivors, the baseline rSO 2 value was 67.5 (46-70) and the percent difference between baseline and rewarming rSO 2 value was 0.03 (0.014-0.435). In non-survivors, the baseline rSO 2 value was 30 (25-65) and the percent difference between baseline and rewarming rSO 2 value was 0.031 (-0.08 to -20). No statistical difference was detected on percent changes between baseline and rewarming values of rSO 2. Statistically significant difference was detected between baseline and rewarming GCS groups (p=0.004). No statistical difference was detected between GCS, CR, PR, BE and rSO 2 to determine the prognosis. Despite higher values of rSO 2 on survivors than non-survivors, we found no statistically considerable difference between groups on baseline and the rewarming rSO 2 values. Since the measurement is simple, and not affected by hypotension and hypothermia, the rSO 2 may be a useful predictor for determining the prognosis after CPR. Copyright © 2016 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  3. Property Values as a Measure of Neighborhoods: An Application of Hedonic Price Theory.

    PubMed

    Leonard, Tammy; Powell-Wiley, Tiffany M; Ayers, Colby; Murdoch, James C; Yin, Wenyuan; Pruitt, Sandi L

    2016-07-01

    Researchers measuring relationships between neighborhoods and health have begun using property appraisal data as a source of information about neighborhoods. Economists have developed a rich tool kit to understand how neighborhood characteristics are quantified in appraisal values. This tool kit principally relies on hedonic (implicit) price models and has much to offer regarding the interpretation and operationalization of property appraisal data-derived neighborhood measures, which goes beyond the use of appraisal data as a measure of neighborhood socioeconomic status. We develop a theoretically informed hedonic-based neighborhood measure using residuals of a hedonic price regression applied to appraisal data in a single metropolitan area. We describe its characteristics, reliability in different types of neighborhoods, and correlation with other neighborhood measures (i.e., raw neighborhood appraisal values, census block group poverty, and observed property characteristics). We examine the association between all neighborhood measures and body mass index. The hedonic-based neighborhood measure was correlated in the expected direction with block group poverty rate and observed property characteristics. The neighborhood measure and average raw neighborhood appraisal value, but not census block group poverty, were associated with individual body mass index. We draw theoretically consistent methodology from the economics literature on hedonic price models to demonstrate how to leverage the implicit valuation of neighborhoods contained in publicly available appraisal data. Consistent measurement and application of the hedonic-based neighborhood measures in epidemiology will improve understanding of the relationships between neighborhoods and health. Researchers should proceed with a careful use of appraisal values utilizing theoretically informed methods such as this one.

  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

    SciTech Connect

    Gutiérrez Castillo, J. G., E-mail: jggc59@hotmail.com; Álvarez Romero, J. T., E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx; Calderón, A. Torres, E-mail: trinidad.alvarez@inin.gob.mx, E-mail: fisarmandotorres@gmail.com, E-mail: victor.tovar@inin.gob.mx

    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 capsulesmore » 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%.« less

  5. Dollar$ & $en$e. Part IV: Measuring the value of people, structural, and customer capital.

    PubMed

    Wilkinson, I

    2001-01-01

    In Part I of this series, I introduced the concept of memes (1). Memes are ideas or concepts, the information world equivalent of genes. The goal of this series of articles is to infect you with my memes, so that you will assimilate, translate, and express them. We discovered that no matter what our area of expertise or "-ology," we all are in the information business. Our goal is to be in the wisdom business. We saw that when we convert raw data into wisdom we are moving along a value chain. Each step in the chain adds a different amount of value to the final product: timely, relevant, accurate, and precise knowledge which can then be applied to create the ultimate product in the value chain: wisdom. In Part II of this series, I infected you with a set of memes for measuring the cost of adding value (2). In Part III of this series, I infected you with a new set of memes for measuring the added value of knowledge, i.e., intellectual capital (3). In Part IV of this series, I will infect you with memes for measuring the value of people, structural, and customer capital.

  6. [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

  7. An automated A-value measurement tool for accurate cochlear duct length estimation.

    PubMed

    Iyaniwura, John E; Elfarnawany, Mai; Ladak, Hanif M; Agrawal, Sumit K

    2018-01-22

    There has been renewed interest in the cochlear duct length (CDL) for preoperative cochlear implant electrode selection and postoperative generation of patient-specific frequency maps. The CDL can be estimated by measuring the A-value, which is defined as the length between the round window and the furthest point on the basal turn. Unfortunately, there is significant intra- and inter-observer variability when these measurements are made clinically. The objective of this study was to develop an automated A-value measurement algorithm to improve accuracy and eliminate observer variability. Clinical and micro-CT images of 20 cadaveric cochleae specimens were acquired. The micro-CT of one sample was chosen as the atlas, and A-value fiducials were placed onto that image. Image registration (rigid affine and non-rigid B-spline) was applied between the atlas and the 19 remaining clinical CT images. The registration transform was applied to the A-value fiducials, and the A-value was then automatically calculated for each specimen. High resolution micro-CT images of the same 19 specimens were used to measure the gold standard A-values for comparison against the manual and automated methods. The registration algorithm had excellent qualitative overlap between the atlas and target images. The automated method eliminated the observer variability and the systematic underestimation by experts. Manual measurement of the A-value on clinical CT had a mean error of 9.5 ± 4.3% compared to micro-CT, and this improved to an error of 2.7 ± 2.1% using the automated algorithm. Both the automated and manual methods correlated significantly with the gold standard micro-CT A-values (r = 0.70, p < 0.01 and r = 0.69, p < 0.01, respectively). An automated A-value measurement tool using atlas-based registration methods was successfully developed and validated. The automated method eliminated the observer variability and improved accuracy as compared to manual

  8. Measuring the Value of New Drugs: Validity and Reliability of 4 Value Assessment Frameworks in the Oncology Setting.

    PubMed

    Bentley, Tanya G K; Cohen, Joshua T; Elkin, Elena B; Huynh, Julie; Mukherjea, Arnab; Neville, Thanh H; Mei, Matthew; Copher, Ronda; Knoth, Russell; Popescu, Ioana; Lee, Jackie; Zambrano, Jenelle M; Broder, Michael S

    2017-06-01

    Several organizations have developed frameworks to systematically assess the value of new drugs. To evaluate the convergent validity and interrater reliability of 4 value frameworks to understand the extent to which these tools can facilitate value-based treatment decisions in oncology. Eight panelists used the American Society of Clinical Oncology (ASCO), European Society for Medical Oncology (ESMO), Institute for Clinical and Economic Review (ICER), and National Comprehensive Cancer Network (NCCN) frameworks to conduct value assessments of 15 drugs for advanced lung and breast cancers and castration-refractory prostate cancer. Panelists received instructions and published clinical data required to complete the assessments, assigning each drug a numeric or letter score. Kendall's Coefficient of Concordance for Ranks (Kendall's W) was used to measure convergent validity by cancer type among the 4 frameworks. Intraclass correlation coefficients (ICCs) were used to measure interrater reliability for each framework across cancers. Panelists were surveyed on their experiences. Kendall's W across all 4 frameworks for breast, lung, and prostate cancer drugs was 0.560 (P= 0.010), 0.562 (P = 0.010), and 0.920 (P < 0.001), respectively. Pairwise, Kendall's W for breast cancer drugs was highest for ESMO-ICER and ICER-NCCN (W = 0.950, P = 0.019 for both pairs) and lowest for ASCO-NCCN (W = 0.300, P = 0.748). For lung cancer drugs, W was highest pairwise for ESMO-ICER (W = 0.974, P = 0.007) and lowest for ASCO-NCCN (W = 0.218, P = 0.839); for prostate cancer drugs, pairwise W was highest for ICER-NCCN (W = 1.000, P < 0.001) and lowest for ESMO-ICER and ESMO-NCCN (W = 0.900, P = 0.052 for both pairs). When ranking drugs on distinct framework subdomains, Kendall's W among breast cancer drugs was highest for certainty (ICER, NCCN: W = 0.908, P = 0.046) and lowest for clinical benefit (ASCO, ESMO, NCCN: W = 0.345, P = 0.436). Among lung cancer drugs, W was highest for toxicity

  9. Calculating meal glycemic index by using measured and published food values compared with directly measured meal glycemic index.

    PubMed

    Dodd, Hayley; Williams, Sheila; Brown, Rachel; Venn, Bernard

    2011-10-01

    Glycemic index (GI) testing is normally based on individual foods, whereas GIs for meals or diets are based on a formula using a weighted sum of the constituents. The accuracy with which the formula can predict a meal or diet GI is questionable. Our objective was to compare the GI of meals, obtained by using the formula and by using both measured food GI and published values, with directly measured meal GIs. The GIs of 7 foods were tested in 30 healthy people. The foods were combined into 3 meals, each of which provided 50 g available carbohydrate, including a staple (potato, rice, or spaghetti), vegetables, sauce, and pan-fried chicken. The mean (95% CI) meal GIs determined from individual food GI values and by direct measurement were as follows: potato meal [predicted, 63 (56, 70); measured, 53 (46, 62)], rice meal [predicted, 51 (45, 56); measured, 38 (33, 45)], and spaghetti meal [predicted, 54 (49, 60); measured, 38 (33, 44)]. The predicted meal GIs were all higher than the measured GIs (P < 0.001). The extent of the overestimation depended on the particular food, ie, 12, 15, and 19 GI units (or 22%, 40%, and 50%) for the potato, rice, and spaghetti meals, respectively. The formula overestimated the GI of the meals by between 22% and 50%. The use of published food values also overestimated the measured meal GIs. Investigators using the formula to calculate a meal or diet GI should be aware of limitations in the method. This trial is registered with the Australian and New Zealand Clinical Trials Registry as ACTRN12611000210976.

  10. Critical micelle concentration values for different surfactants measured with solid-phase microextraction fibers.

    PubMed

    Haftka, Joris J-H; Scherpenisse, Peter; Oetter, Günter; Hodges, Geoff; Eadsforth, Charles V; Kotthoff, Matthias; Hermens, Joop L M

    2016-09-01

    The amphiphilic nature of surfactants drives the formation of micelles at the critical micelle concentration (CMC). Solid-phase microextraction (SPME) fibers were used in the present study to measure CMC values of 12 nonionic, anionic, cationic, and zwitterionic surfactants. The SPME-derived CMC values were compared to values determined using a traditional surface tension method. At the CMC of a surfactant, a break in the relationship between the concentration in SPME fibers and the concentration in water is observed. The CMC values determined with SPME fibers deviated by less than a factor of 3 from values determined with a surface tension method for 7 out of 12 compounds. In addition, the fiber-water sorption isotherms gave information about the sorption mechanism to polyacrylate-coated SPME fibers. A limitation of the SPME method is that CMCs for very hydrophobic cationic surfactants cannot be determined when the cation exchange capacity of the SPME fibers is lower than the CMC value. The advantage of the SPME method over other methods is that CMC values of individual compounds in a mixture can be determined with this method. However, CMC values may be affected by the presence of compounds with other chain lengths in the mixture because of possible mixed micelle formation. Environ Toxicol Chem 2016;35:2173-2181. © 2016 SETAC. © 2016 SETAC.

  11. A National Trial on Differences in Cerebral Perfusion Pressure Values by Measurement Location.

    PubMed

    McNett, Molly M; Bader, Mary Kay; Livesay, Sarah; Yeager, Susan; Moran, Cristina; Barnes, Arianna; Harrison, Kimberly R; Olson, DaiWai M

    2018-04-01

    Cerebral perfusion pressure (CPP) is a key parameter in management of brain injury with suspected impaired cerebral autoregulation. CPP is calculated by subtracting intracranial pressure (ICP) from mean arterial pressure (MAP). Despite consensus on importance of CPP monitoring, substantial variations exist on anatomical reference points used to measure arterial MAP when calculating CPP. This study aimed to identify differences in CPP values based on measurement location when using phlebostatic axis (PA) or tragus (Tg) as anatomical reference points. The secondary study aim was to determine impact of differences on patient outcomes at discharge. This was a prospective, repeated measures, multi-site national trial. Adult ICU patients with neurological injury necessitating ICP and CPP monitoring were consecutively enrolled from seven sites. Daily MAP/ICP/CPP values were gathered with the arterial transducer at the PA, followed by the Tg as anatomical reference points. A total of 136 subjects were enrolled, resulting in 324 paired observations. There were significant differences for CPP when comparing values obtained at PA and Tg reference points (p < 0.000). Differences remained significant in repeated measures model when controlling for clinical factors (mean CPP-PA = 80.77, mean CPP-Tg = 70.61, p < 0.000). When categorizing CPP as binary endpoint, 18.8% of values were identified as adequate with PA values, yet inadequate with CPP values measured at the Tg. Findings identify numerical differences for CPP based on anatomical reference location and highlight importance of a standard reference point for both clinical practice and future trials to limit practice variations and heterogeneity of findings.

  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. A Value Measure for Public-Sector Enterprise Risk Management: A TSA Case Study.

    PubMed

    Fletcher, Kenneth C; Abbas, Ali E

    2018-05-01

    This article presents a public value measure that can be used to aid executives in the public sector to better assess policy decisions and maximize value to the American people. Using Transportation Security Administration (TSA) programs as an example, we first identify the basic components of public value. We then propose a public value account to quantify the outcomes of various risk scenarios, and we determine the certain equivalent of several important TSA programs. We illustrate how this proposed measure can quantify the effects of two main challenges that government organizations face when conducting enterprise risk management: (1) short-term versus long-term incentives and (2) avoiding potential negative consequences even if they occur with low probability. Finally, we illustrate how this measure enables the use of various tools from decision analysis to be applied in government settings, such as stochastic dominance arguments and certain equivalent calculations. Regarding the TSA case study, our analysis demonstrates the value of continued expansion of the TSA trusted traveler initiative and increasing the background vetting for passengers who are afforded expedited security screening. © 2017 Society for Risk Analysis.

  14. Prognostic and diagnostic value of EEG signal coupling measures in coma.

    PubMed

    Zubler, Frederic; Koenig, Christa; Steimer, Andreas; Jakob, Stephan M; Schindler, Kaspar A; Gast, Heidemarie

    2016-08-01

    Our aim was to assess the diagnostic and predictive value of several quantitative EEG (qEEG) analysis methods in comatose patients. In 79 patients, coupling between EEG signals on the left-right (inter-hemispheric) axis and on the anterior-posterior (intra-hemispheric) axis was measured with four synchronization measures: relative delta power asymmetry, cross-correlation, symbolic mutual information and transfer entropy directionality. Results were compared with etiology of coma and clinical outcome. Using cross-validation, the predictive value of measure combinations was assessed with a Bayes classifier with mixture of Gaussians. Five of eight measures showed a statistically significant difference between patients grouped according to outcome; one measure revealed differences in patients grouped according to the etiology. Interestingly, a high level of synchrony between the left and right hemisphere was associated with mortality on intensive care unit, whereas higher synchrony between anterior and posterior brain regions was associated with survival. The combination with the best predictive value reached an area-under the curve of 0.875 (for patients with post anoxic encephalopathy: 0.946). EEG synchronization measures can contribute to clinical assessment, and provide new approaches for understanding the pathophysiology of coma. Prognostication in coma remains a challenging task. qEEG could improve current multi-modal approaches. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  15. Apollo couch energy absorbers

    NASA Technical Reports Server (NTRS)

    Wesselski, C. J.; Drexel, R. E.

    1972-01-01

    Load attenuators for the Apollo spacecraft crew couch and its potential applications are described. Energy absorption is achieved through friction and cyclic deformation of material. In one concept, energy absorption is accomplished by rolling a compressed ring of metal between two surfaces. In another concept, energy is absorbed by forcing a plastically deformed washer along a rod. Among the design problems that had to be solved were material selection, fatigue life, ring slippage, lubrication, and friction loading.

  16. 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".

  17. Measurement of 13C chemical shift tensor principal values with a magic-angle turning experiment.

    PubMed

    Hu, J Z; Orendt, A M; Alderman, D W; Pugmire, R J; Ye, C; Grant, D M

    1994-08-01

    The magic-angle turning (MAT) experiment introduced by Gan is developed into a powerful and routine method for measuring the principal values of 13C chemical shift tensors in powdered solids. A large-volume MAT probe with stable rotation frequencies down to 22 Hz is described. A triple-echo MAT pulse sequence is introduced to improve the quality of the two-dimensional baseplane. It is shown that measurements of the principal values of chemical shift tensors in complex compounds can be enhanced by using either short contact times or dipolar dephasing pulse sequences to isolate the powder patterns from protonated or non-protonated carbons, respectively. A model compound, 1,2,3-trimethoxybenzene, is used to demonstrate these techniques, and the 13C principal values in 2,3-dimethylnaphthalene and Pocahontas coal are reported as typical examples.

  18. Measuring the Value of Public Health Systems: The Disconnect Between Health Economists and Public Health Practitioners

    PubMed Central

    Jacobson, Peter D.; Palmer, Jennifer A.

    2008-01-01

    We investigated ways of defining and measuring the value of services provided by governmental public health systems. Our data sources included literature syntheses and qualitative interviews of public health professionals. Our examination of the health economic literature revealed growing attempts to measure value of public health services explicitly, but few studies have addressed systems or infrastructure. Interview responses demonstrated no consensus on metrics and no connection to the academic literature. Key challenges for practitioners include developing rigorous, data-driven methods and skilled staff; being politically willing to base allocation decisions on economic evaluation; and developing metrics to capture “intangibles” (e.g., social justice and reassurance value). Academic researchers evaluating the economics of public health investments should increase focus on the working needs of public health professionals. PMID:18923123

  19. The advantages of absorbed-dose calibration factors.

    PubMed

    Rogers, D W

    1992-01-01

    A formalism for clinical external beam dosimetry based on use of ion chamber absorbed-dose calibration factors is outlined in the context and notation of the AAPM TG-21 protocol. It is shown that basing clinical dosimetry on absorbed-dose calibration factors ND leads to considerable simplification and reduced uncertainty in dose measurement. In keeping with a protocol which is used in Germany, a quantity kQ is defined which relates an absorbed-dose calibration factor in a beam of quality Q0 to that in a beam of quality Q. For 38 cylindrical ion chambers, two sets of values are presented for ND/NX and Ngas/ND and for kQ for photon beams with beam quality specified by the TPR20(10) ratio. One set is based on TG-21's protocol to allow the new formalism to be used while maintaining equivalence to the TG-21 protocol. To demonstrate the magnitude of the overall error in the TG-21 protocol, the other set uses corrected versions of the TG-21 equations and the more consistent physical data of the IAEA Code of Practice. Comparisons are made to procedures based on air-kerma or exposure calibration factors and it is shown that accuracy and simplicity are gained by avoiding the determination of Ngas from NX. It is also shown that the kQ approach simplifies the use of plastic phantoms in photon beams since kQ values change by less than 0.6% compared to those in water although an overall correction factor of 0.973 is needed to go from absorbed dose in water calibration factors to those in PMMA or polystyrene. Values of kQ calculated using the IAEA Code of Practice are presented but are shown to be anomalous because of the way the effective point of measurement changes for 60Co beams. In photon beams the major difference between the IAEA Code of Practice and the corrected AAPM TG-21 protocol is shown to be the Prepl correction factor. Calculated kQ curves and three parameter equations for them are presented for each wall material and are shown to represent accurately the kQ curve

  20. 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…

  1. 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…

  2. Career Assessment: Interest and Values Measures for Tech Prep and School-to-Work Programs.

    ERIC Educational Resources Information Center

    Kapes, Jerome T.; Martinez, Linda

    This paper describes and compares interests and values measures useful for career assessment and counseling in tech prep and school-to-work programs. The primary source of information for this information is the third edition of "A Counselor's Guide to Career Assessment Instruments" (Kapes, Mastie, and Whitfield 1994). Stated objectives…

  3. 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…

  4. Measuring Striving for Understanding and Learning Value of Geometry: A Validity Study

    ERIC Educational Resources Information Center

    Ubuz, Behiye; Aydinyer, Yurdagül

    2017-01-01

    The current study aimed to construct a questionnaire that measures students' personality traits related to "striving for understanding" and "learning value of geometry" and then examine its psychometric properties. Through the use of multiple methods on two independent samples of 402 and 521 middle school students, two studies…

  5. 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…

  6. Alternative method of quantum state tomography toward a typical target via a weak-value measurement

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Dai, Hong-Yi; Yang, Le; Zhang, Ming

    2018-03-01

    There is usually a limitation of weak interaction on the application of weak-value measurement. This limitation dominates the performance of the quantum state tomography toward a typical target in the finite and high-dimensional complex-valued superposition of its basis states, especially when the compressive sensing technique is also employed. Here we propose an alternative method of quantum state tomography, presented as a general model, toward such typical target via weak-value measurement to overcome such limitation. In this model the pointer for the weak-value measurement is a qubit, and the target-pointer coupling interaction is no longer needed within the weak interaction limitation, meanwhile this interaction under the compressive sensing can be described with the Taylor series of the unitary evolution operator. The postselection state at the target is the equal superposition of all basis states, and the pointer readouts are gathered under multiple Pauli operator measurements. The reconstructed quantum state is generated from an optimization algorithm of total variation augmented Lagrangian alternating direction algorithm. Furthermore, we demonstrate an example of this general model for the quantum state tomography toward the planar laser-energy distribution and discuss the relations among some parameters at both our general model and the original first-order approximate model for this tomography.

  7. 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…

  8. 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.

  9. We do not know what we do not know: innovative approaches to value measurement.

    PubMed

    Laviana, Aaron A; Resnick, Matthew J

    2018-07-01

    Over the past several years, there has been an increasing focus on improving the 'value' of healthcare delivered, defined as the ratio of clinical outcomes to the costs incurred to achieve them. The former U.S. Secretary of Health and Human Services Sylvia Burwell announced in 2015 that the majority of healthcare payments in the Medicare and Medicaid programmes will align with value by 2018. Although this has yet to fully mature, numerous health systems have restructured with a goal of improving the value of care delivered to their populations. Nevertheless, there remain important unanswered questions regarding how we measure value in the current U.S. healthcare system. The purpose of this review is to highlight innovations that are not only making it easier to measure value but also to improve care from the patient, provider and healthcare system perspectives. Behavioural start-ups and the introduction of relatively inexpensive health coaches are starting to permeate the healthcare landscape. These coaches are the consumers' advocate, acting as the quarterback of an extended care team in order to optimize health. Furthermore, time-driven activity-based costing has allowed us to understand costs on a more granular level, and novel tracking software may further automate these costing algorithms in order to better facilitate their dissemination. We must all work to enable new models of care that improve value by incentivizing individuals, payers and providers to improve health, rather than treat the disease after it manifests. We must also continue to improve the efficiency of healthcare delivery largely through improvements in value measurement.

  10. Effects of caffeine on fractional flow reserve values measured using intravenous adenosine triphosphate.

    PubMed

    Nakayama, Masafumi; Chikamori, Taishiro; Uchiyama, Takashi; Kimura, Yo; Hijikata, Nobuhiro; Ito, Ryosuke; Yuhara, Mikio; Sato, Hideaki; Kobori, Yuichi; Yamashina, Akira

    2018-04-01

    We investigated the effects of caffeine intake on fractional flow reserve (FFR) values measured using intravenous adenosine triphosphate (ATP) before cardiac catheterization. Caffeine is a competitive antagonist for adenosine receptors; however, it is unclear whether this antagonism affects FFR values. Patients were evenly randomized into 2 groups preceding the FFR study. In the caffeine group (n = 15), participants were given coffee containing 222 mg of caffeine 2 h before the catheterization. In the non-caffeine group (n = 15), participants were instructed not to take any caffeine-containing drinks or foods for at least 12 h before the catheterization. FFR was performed in patients with more than intermediate coronary stenosis using the intravenous infusion of ATP at 140 μg/kg/min (normal dose) and 170 μg/kg/min (high dose), and the intracoronary infusion of papaverine. FFR was followed for 30 s after maximal hyperemia. In the non-caffeine group, the FFR values measured with ATP infusion were not significantly different from those measured with papaverine infusion. However, in the caffeine group, the FFR values were significantly higher after ATP infusion than after papaverine infusion (P = 0.002 and P = 0.007, at normal and high dose ATP vs. papaverine, respectively). FFR values with ATP infusion were significantly increased 30 s after maximal hyperemia (P = 0.001 and P < 0.001 for normal and high dose ATP, respectively). The stability of the FFR values using papaverine showed no significant difference between the 2 groups. Caffeine intake before the FFR study affected FFR values and their stability. These effects could not be reversed by an increased ATP dose.

  11. 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.

  12. Network analysis of surgical innovation: Measuring value and the virality of diffusion in robotic surgery.

    PubMed

    Garas, George; Cingolani, Isabella; Panzarasa, Pietro; Darzi, Ara; Athanasiou, Thanos

    2017-01-01

    Existing surgical innovation frameworks suffer from a unifying limitation, their qualitative nature. A rigorous approach to measuring surgical innovation is needed that extends beyond detecting simply publication, citation, and patent counts and instead uncovers an implementation-based value from the structure of the entire adoption cascades produced over time by diffusion processes. Based on the principles of evidence-based medicine and existing surgical regulatory frameworks, the surgical innovation funnel is described. This illustrates the different stages through which innovation in surgery typically progresses. The aim is to propose a novel and quantitative network-based framework that will permit modeling and visualizing innovation diffusion cascades in surgery and measuring virality and value of innovations. Network analysis of constructed citation networks of all articles concerned with robotic surgery (n = 13,240, Scopus®) was performed (1974-2014). The virality of each cascade was measured as was innovation value (measured by the innovation index) derived from the evidence-based stage occupied by the corresponding seed article in the surgical innovation funnel. The network-based surgical innovation metrics were also validated against real world big data (National Inpatient Sample-NIS®). Rankings of surgical innovation across specialties by cascade size and structural virality (structural depth and width) were found to correlate closely with the ranking by innovation value (Spearman's rank correlation coefficient = 0.758 (p = 0.01), 0.782 (p = 0.008), 0.624 (p = 0.05), respectively) which in turn matches the ranking based on real world big data from the NIS® (Spearman's coefficient = 0.673;p = 0.033). Network analysis offers unique new opportunities for understanding, modeling and measuring surgical innovation, and ultimately for assessing and comparing generative value between different specialties. The novel surgical innovation metrics developed may

  13. 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

  14. 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.

  15. Calculating Measurement Uncertainty of the “Conventional Value of the Result of Weighing in Air”

    DOE PAGES

    Flicker, Celia J.; Tran, Hy D.

    2016-04-02

    The conventional value of the result of weighing in air is frequently used in commercial calibrations of balances. The guidance in OIML D-028 for reporting uncertainty of the conventional value is too terse. When calibrating mass standards at low measurement uncertainties, it is necessary to perform a buoyancy correction before reporting the result. When calculating the conventional result after calibrating true mass, the uncertainty due to calculating the conventional result is correlated with the buoyancy correction. We show through Monte Carlo simulations that the measurement uncertainty of the conventional result is less than the measurement uncertainty when reporting true mass.more » The Monte Carlo simulation tool is available in the online version of this article.« less

  16. New measurements of W-values for protons and alpha particles.

    PubMed

    Giesen, U; Beck, J

    2014-10-01

    The increasing importance of ion beams in cancer therapy and the lack of experimental data for W-values for protons and heavy ions in air require new measurements. A new experimental set-up was developed at PTB and consistent measurements of W-values in argon, nitrogen and air for protons and alpha particles with energies from 0.7 to 3.5 MeV u(-1) at PTB, and for carbon ions between 3.6 and 7.0 MeV u(-1) at GSI were carried out. This publication concentrates on the measurements with protons and alpha particles at PTB. The experimental methods and the determination of corrections for recombination effects, beam-induced background radiation and additional effects are presented. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. A quantum inspired model of radar range and range-rate measurements with applications to weak value measurements

    NASA Astrophysics Data System (ADS)

    Escalante, George

    2017-05-01

    Weak Value Measurements (WVMs) with pre- and post-selected quantum mechanical ensembles were proposed by Aharonov, Albert, and Vaidman in 1988 and have found numerous applications in both theoretical and applied physics. In the field of precision metrology, WVM techniques have been demonstrated and proven valuable as a means to shift, amplify, and detect signals and to make precise measurements of small effects in both quantum and classical systems, including: particle spin, the Spin-Hall effect of light, optical beam deflections, frequency shifts, field gradients, and many others. In principal, WVM amplification techniques are also possible in radar and could be a valuable tool for precision measurements. However, relatively limited research has been done in this area. This article presents a quantum-inspired model of radar range and range-rate measurements of arbitrary strength, including standard and pre- and post-selected measurements. The model is used to extend WVM amplification theory to radar, with the receive filter performing the post-selection role. It is shown that the description of range and range-rate measurements based on the quantum-mechanical measurement model and formalism produces the same results as the conventional approach used in radar based on signal processing and filtering of the reflected signal at the radar receiver. Numerical simulation results using simple point scatterrer configurations are presented, applying the quantum-inspired model of radar range and range-rate measurements that occur in the weak measurement regime. Potential applications and benefits of the quantum inspired approach to radar measurements are presented, including improved range and Doppler measurement resolution.

  18. Hyperspectral photoacoustic spectroscopy of highly-absorbing samples for diagnostic ocular imaging applications

    NASA Astrophysics Data System (ADS)

    Lim, Hoong-Ta; Murukeshan, Vadakke Matham

    2017-01-01

    Photoacoustic spectroscopy has been used to measure optical absorption coefficient and the application of tens of wavelength bands in photoacoustic spectroscopy was reported. Using optical methods, absorption-related information is, generally, derived from reflectance or transmittance values. Hence measurement accuracy is limited for highly absorbing samples where the reflectance or transmittance is too low to give reasonable signal-to-noise ratio. In this context, this paper proposes and illustrates a hyperspectral photoacoustic spectroscopy system to measure the absorption-related properties of highly absorbing samples directly. The normalized optical absorption coefficient spectrum of the highly absorbing iris is acquired using an optical absorption coefficient standard. The proposed concepts and the feasibility of the developed diagnostic medical imaging system are demonstrated using fluorescent microsphere suspensions and porcine eyes as test samples.

  19. 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

  20. Reference values for physical performance measures in the aging working population.

    PubMed

    Cote, Mark P; Kenny, Anne; Dussetschleger, Jeffrey; Farr, Dana; Chaurasia, Ashok; Cherniack, Martin

    2014-02-01

    The aim of this study was to determine reference physical performance values in older aging workers. Cross-sectional physical performance measures were collected for 736 manufacturing workers to assess effects of work and nonwork factors on age-related changes in musculoskeletal function and health. Participants underwent surveys and physical testing that included bioelectrical impedance analysis, range-of-motion measures, exercise testing, and dynamic assessment. Physical characteristics, such as blood pressure and body fat percentage, were comparable to published values. Dynamic and range-of-motion measurements differed from published normative results. Women had age-related decreases in cervical extension and lateral rotation. Older men had better spinal flexion than expected. Predicted age-related decline in lower-extremity strength and shoulder strength in women was not seen. Men declined in handgrip, lower-extremity strength, and knee extension strength, but not trunk strength, across age groups. There was no appreciable decline in muscle fatigue at the trunk, shoulder, and knee with aging for either gender, except for the youngest age group of women. Normative values may underestimate physical performance in "healthy" older workers, thereby underappreciating declines in less healthy older workers. Work may be preservative of function for a large group of selected individuals. A "healthy worker effect" may be greater for musculoskeletal disease and function than for heart disease and mortality. Clinicians and researchers studying musculoskeletal function in older workers can use a more specific set of reference values.

  1. 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.

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

    SciTech Connect

    Di Lorenzo, Antonio, E-mail: dilorenzo.antonio@gmail.com

    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 maximizesmore » 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.« less

  3. 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.

  4. Quality, Safety, Value: From Theory to Practice Management What Should We Measure?

    PubMed

    Shore, Benjamin J; Murphy, Robert F; Hogue, Grant D

    2015-01-01

    Over the past 35 years the health care community and in particular orthopaedic surgery, has undergone a transformation from retrospective case-series-based expert opinion to randomized prospective clinical trials. During this transition, orthopaedic surgeons have become very skilled in the measurement of physician-derived outcomes (radiographic angles, complications, recurrences, and mortality); however, these are not patient-centered outcomes and they are of little importance to our patients' satisfaction. Moving forward outcome measurement needs to be restructured to focus more on patient-reported outcomes. This paper outlines why outcome measurement is important, reviews outcome strategies that have been used historically, introduces a new outcome measurement tool and identifies strategies for future implementation and measurement of health care quality and value within pediatric orthopaedics.

  5. 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.

  6. 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.

  7. Corrosion resistant neutron absorbing coatings

    DOEpatents

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    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.

  8. Corrosion resistant neutron absorbing coatings

    DOEpatents

    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.

  9. Anorectal physiology measurements are of no value in clinical practice. True or false?

    PubMed Central

    Carty, N. J.; Moran, B.; Johnson, C. D.

    1994-01-01

    This article examines whether there is any clinical value in anorectal physiology measurements. The function of the human rectum is poorly understood and the factors which affect function of the anal sphincters are complex. Several laboratories have reported results of anorectal physiology measurements, but there is extensive variation between normal values in different laboratories. It is argued that anorectal physiology measurements fail to meet the criteria of a useful clinical test: 1. It is not widely available to clinicians; 2. It is not possible to establish a reproducible normal range; 3. Abnormal measurements do not correlate with disease entities or explain symptoms; 4. The results are often unhelpful in diagnosis and management; 5. Clinical outcome after intervention does not correlate with alteration in the measurements obtained. On the other hand it can be argued that anorectal physiology measurements do provide information that assists in the management of conditions such as constipation, anismus, Hirschsprung's disease, faecal incontinence and tenesmus. Management based on biofeedback modification of physiological responses requires these techniques as part of the biofeedback system. There is evidence that this may be appropriate in anismus and solitary rectal ulcer syndrome. However, the assessment of these difficult conditions and the interpretation of the results are probably at present best confined to specialist units. PMID:8074392

  10. Reference values for developing responsive functional outcome measures across the lifespan.

    PubMed

    McKay, Marnee J; Baldwin, Jennifer N; Ferreira, Paulo; Simic, Milena; Vanicek, Natalie; Burns, Joshua

    2017-04-18

    To generate a reference dataset of commonly performed functional outcome measures in 1,000 children and adults and investigate the influence of demographic, anthropometric, strength, and flexibility characteristics. Twelve functional outcome measures were collected from 1,000 healthy individuals aged 3-101 years: 6-minute walk test, 30-second chair stand test, timed stairs test, long jump, vertical jump, choice stepping reaction time, balance (Star Excursion Balance Test, tandem stance eyes open and closed, single-leg stance eyes closed), and dexterity (9-hole peg test, Functional Dexterity Test). Correlation and multiple regression analyses were performed to identify factors independently associated with each measure. Age- and sex-stratified reference values for functional outcome measures were generated. Functional performance increased through childhood and adolescence, plateaued during adulthood, and declined in older adulthood. While balance did not differ between the sexes, male participants generally performed better at gross motor tasks while female participants performed better at dexterous tasks. Height was the most consistent correlate of functional performance in children, while lower limb muscle strength was a major determinant in adolescents and adults. In older adults, age, lower limb strength, and joint flexibility explained up to 63% of the variance in functional measures. These normative reference values provide a framework to accurately track functional decline associated with neuromuscular disorders and assist development and validation of responsive outcome measures for therapeutic trials. © 2017 American Academy of Neurology.

  11. The incremental value of self-reported mental health measures in predicting functional outcomes of veterans.

    PubMed

    Eisen, Susan V; Bottonari, Kathryn A; Glickman, Mark E; Spiro, Avron; Schultz, Mark R; Herz, Lawrence; Rosenheck, Robert; Rofman, Ethan S

    2011-04-01

    Research on patient-centered care supports use of patient/consumer self-report measures in monitoring health outcomes. This study examined the incremental value of self-report mental health measures relative to a clinician-rated measure in predicting functional outcomes among mental health service recipients. Participants (n = 446) completed the Behavior and Symptom Identification Scale, the Brief Symptom Inventory, and the Veterans/Rand Short Form-36 at enrollment in the study (T1) and 3 months later (T2). Global Assessment of Functioning (GAF) ratings, mental health service utilization, and psychiatric diagnoses were obtained from administrative data files. Controlling for demographic and clinical variables, results indicated that improvement based on the self-report measures significantly predicted one or more functional outcomes (i.e., decreased likelihood of post-enrollment psychiatric hospitalization and increased likelihood of paid employment), above and beyond the predictive value of the GAF. Inclusion of self-report measures may be a useful addition to performance measurement efforts.

  12. The added value of measuring thumb and finger strength when comparing strength measurements in hypoplastic thumb patients.

    PubMed

    Molenaar, H M Ties; Selles, Ruud W; de Kraker, Marjolein; Stam, Henk J; Hovius, Steven E R

    2013-10-01

    When interventions to the hand are aimed at improving function of specific fingers or the thumb, the RIHM (Rotterdam Intrinsic Hand Myometer) is a validated tool and offers more detailed information to assess strength of the involved joints besides grip and pinch measurements. In this study, strength was measured in 65 thumbs in 40 patients diagnosed with thumb hypoplasia. These 65 thumbs were classified according to Blauth. Longitudinal radial deficiencies were also classified. The strength measurements comprised of grip, tip, tripod and key pinch. Furthermore palmar abduction and opposition of the thumb as well as abduction of the index and little finger were measured with the RIHM. For all longitudinal radial deficiency patients, grip and pinch strength as well as palmar abduction and thumb opposition were significantly lower than reference values (P<0.001). However, strength in the index finger abduction and the little finger abduction was maintained or decreased to a lesser extent according to the degree of longitudinal radial deficiency. All strength values decreased with increasing Blauth-type. Blauth-type II hands (n=15) with flexor digitorum superficialis 4 opposition transfer including stabilization of the metacarpophalangeal joint showed a trend toward a higher opposition strength without reaching statistical significance (P=0.094),however compared to non-operated Blauth-type II hands (n=6) they showed a lower grip strength (P=0.019). The RIHM is comparable in accuracy to other strength dynamometers. Using the RIHM, we were able to illustrate strength patterns on finger-specific level, showing added value when evaluating outcome in patients with hand related problems. © 2013.

  13. 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.

  14. 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.

  15. 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.

  16. Added value measures in education show genetic as well as environmental influence.

    PubMed

    Haworth, Claire M A; Asbury, Kathryn; Dale, Philip S; Plomin, Robert

    2011-02-02

    Does achievement independent of ability or previous attainment provide a purer measure of the added value of school? In a study of 4000 pairs of 12-year-old twins in the UK, we measured achievement with year-long teacher assessments as well as tests. Raw achievement shows moderate heritability (about 50%) and modest shared environmental influences (25%). Unexpectedly, we show that for indices of the added value of school, genetic influences remain moderate (around 50%), and the shared (school) environment is less important (about 12%). The pervasiveness of genetic influence in how and how much children learn is compatible with an active view of learning in which children create their own educational experiences in part on the basis of their genetic propensities.

  17. The current state of nursing performance measurement, public reporting, and value-based purchasing.

    PubMed

    Kurtzman, Ellen T; Dawson, Ellen M; Johnson, Jean E

    2008-08-01

    Over the last decade, there has been a substantial investment in holding health care providers accountable for the quality of care provided in hospitals and other settings of care. This investment has been realized through the proliferation of national policies that address performance measurement, public reporting, and value-based purchasing. Although nurses represent the largest segment of the health care workforce and despite their acknowledged role in patient safety and health care outcomes, they have been largely absent from policy setting in these areas. This article provides an analysis of current nursing performance measurement and public reporting initiatives and presents a summary of emerging trends in value-based purchasing, with an emphasis on activities in the United States. The article synthesizes issues of relevance to advancing the current climate for nursing quality and concludes with key issues for future policy setting.

  18. 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

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

    PubMed

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

    2013-03-01

    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 2100ml 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. The Role of Patient-Reported Outcome Measures in Value-Based Payment Reform.

    PubMed

    Squitieri, Lee; Bozic, Kevin J; Pusic, Andrea L

    2017-06-01

    The U.S. health care system is currently experiencing profound change. Pressure to improve the quality of patient care and control costs have caused a rapid shift from traditional volume-driven fee-for-service reimbursement to value-based payment models. Under the 2015 Medicare Access and Children's Health Insurance Program Reauthorization Act, providers will be evaluated on the basis of quality and cost efficiency and ultimately receive adjusted reimbursement as per their performance. Although current performance metrics do not incorporate patient-reported outcome measures (PROMs), many wonder whether and how PROMs will eventually fit into value-based payment reform. On November 17, 2016, the second annual Patient-Reported Outcomes in Healthcare Conference brought together international stakeholders across all health care disciplines to discuss the potential role of PROs in value-based health care reform. The purpose of this article was to summarize the findings from this conference in the context of recent literature and guidelines to inform implementation of PROs in value-based payment models. Recommendations for evaluating key perspectives and measurement goals are made to facilitate appropriate use of PROMs to best benefit and amplify the voice of our patients. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

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

    SciTech Connect

    Kuramochi, Yui, E-mail: kuramochi.yui.22c@st.kyoto-u.ac.jp

    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.

  2. Microwave measurements of the absolute values of absorption by water vapour in the atmosphere.

    PubMed

    Hogg, D C; Guiraud, F O

    1979-05-31

    MEASUREMENT of the absolute value of absorption by water vapour at microwave frequencies is difficult because the effect is so small. Far in the wings of the absorption lines, in the so-called 'windows' of the spectrum, it is especially difficult to achieve high accuracy in the free atmosphere. But it is in these windows that the behaviour of the absorption is important from both applied and scientific points of view. Satellite communications, remote sensing of the atmosphere, and radioastronomy, are all influenced by this behaviour. Measurements on an Earth-space path are reported here; the results indicate a nonlinear relationship between absorption and water-vapour content.

  3. An Intercomparison of Lidar Ozone and Temperature Measurements From the SOLVE Mission With Predicted Model Values

    NASA Technical Reports Server (NTRS)

    Burris, John; McGee, Thomas J.; Hoegy, Walt; Lait, Leslie; Sumnicht, Grant; Twigg, Larry; Heaps, William

    2000-01-01

    Temperature profiles acquired by Goddard Space Flight Center's AROTEL lidar during the SOLVE mission onboard NASA's DC-8 are compared with predicted values from several atmospheric models (DAO, NCEP and UKMO). The variability in the differences between measured and calculated temperature fields was approximately 5 K. Retrieved temperatures within the polar vortex showed large regions that were significantly colder than predicted by the atmospheric models.

  4. Partial discharge measurements on 110kV current transformers. Setting the control value. Case study

    NASA Astrophysics Data System (ADS)

    Dan, C.; Morar, R.

    2017-05-01

    The case study presents a series of partial discharge measurements, reflecting the state of insulation of 110kV CURRENT TRANSFORMERS located in Sibiu county substations. Measurements were performed based on electrical method, using MPD600: an acquisition and analysis toolkit for detecting, recording, and analyzing partial discharges. MPD600 consists of one acquisition unit, an optical interface and a computer with dedicated software. The system allows measurements of partial discharge on site, even in presence of strong electromagnetic interferences because it provides synchronous acquisition from all measurement points. Therefore, measurements, with the ability to be calibrated, do render: - a value subject to interpretation according to IEC 61869-1:2007 + IEC 61869-2:2012 + IEC 61869-3:2011 + IEC 61869-5:2011 and IEC 60270: 2000; - the possibility to determine the quantitative limit of PD (a certain control value) to which the equipment can be operated safely and repaired with minimal costs (relative to the high costs implied by eliminating the consequences of a failure) identified empirically (process in which the instrument transformer subjected to the tests was completely destroyed).

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

    SciTech Connect

    Yonas, H.; Darby, J.M.; Marks, E.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 flowmore » 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.« less

  6. Using the New Postacute Care Quality Measures to Demonstrate the Value of Occupational Therapy.

    PubMed

    Sandhu, Sharmila; Furniss, Jeremy; Metzler, Christina

    As the health care system continues to evolve toward one based on quality not quantity, demonstrating the value of occupational therapy has never been more important. Providing high-quality services, achieving optimal outcomes, and identifying and promoting occupational therapy's distinct value are the responsibilities of all practitioners. In relation to the Improving Medicare Post-Acute Care Transformation (IMPACT) Act of 2014, the Centers for Medicare and Medicaid Services (CMS) is implementing new functional items and related outcome performance measures across postacute care (PAC) settings. Practitioners can demonstrate the role and value of occupational therapy services through their participation in data collection and the interpretation of the resulting performance measures. In this column, we review the objectives of the IMPACT Act, introduce the new self-care and mobility items and outcome performance measures being implemented in PAC settings, and describe ways to use these new data to advocate for occupational therapy. We also discuss American Occupational Therapy Association initiatives to provide materials and guidance for occupational therapy practitioners to contribute to PAC data collection. Copyright © 2018 by the American Occupational Therapy Association, Inc.

  7. Hospitals Known for Nursing Excellence Perform Better on Value Based Purchasing Measures

    PubMed Central

    Lasater, Karen B.; Germack, Hayley D.; Small, Dylan S.; McHugh, Matthew D.

    2018-01-01

    It is well-established that hospitals recognized for good nursing care – Magnet hospitals – are associated with better patient outcomes. Less is known about how Magnet hospitals compare to non-Magnets on quality measures linked to Medicare reimbursement. The purpose of this study was to determine how Magnet hospitals perform compared to matched non-Magnet hospitals on Hospital Value Based Purchasing (VBP) measures. A cross-sectional analysis of three linked data sources was performed. The sample included 3,021 non-federal acute care hospitals participating in the VBP program (323 Magnets; 2,698 non-Magnets). Propensity score matching was used to match Magnet and non-Magnet hospitals with similar hospital characteristics. After matching, linear and logistic regression models were used to examine the relationship between Magnet status and VBP performance. After matching and adjusting for hospital characteristics, Magnet recognition predicted higher scores on Total Performance (Regression Coefficient [RC] = 1.66, p < 0.05), Clinical Processes (RC = 3.85; p < 0.01), and Patient Experience (RC = 6.33; p < 0.001). The relationships between Magnet recognition and the Outcome and Efficiency domains were not statistically significant. Magnet hospitals known for nursing excellence perform better on Hospital VBP measures. As healthcare systems adapt to evolving incentives that reward value, attention to nurses at the front lines may be central to ensuring high-value care for patients. PMID:28558604

  8. 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…

  9. Blood glucose measurement in patients with suspected diabetic ketoacidosis: a comparison of Abbott MediSense PCx point-of-care meter values to reference laboratory values.

    PubMed

    Blank, Fidela S J; Miller, Moses; Nichols, James; Smithline, Howard; Crabb, Gillian; Pekow, Penelope

    2009-04-01

    The purpose of this study is to compare blood glucose levels measured by a point of care (POC) device to laboratory measurement using the same sample venous blood from patients with suspected diabetic ketoacidosis (DKA). A descriptive correlational design was used for this IRB-approved quality assurance project. The study site was the 50-bed BMC emergency department (ED) which has an annual census of over 100,000 patient visits. The convenience sample consisted of 54 blood samples from suspected DKA patients with orders for hourly blood draws for glucose measurement. Spearman correlations of the glucose POC values, reference lab values, and differences between the two, were evaluated. A chi-square test was used to evaluate the association between the acidosis status and FDA acceptability of POC values. Patient age range was 10-86 years; 63% were females; 46% had a final diagnosis of DKA. POC values underestimated glucose levels 93% of the time. There was a high correlation between the lab value and the magnitude of the difference, (lab minus POC value) indicating that the higher the true glucose value, the greater the difference between the lab and the POC value. A chi-square test showed no overall association between acidosis and FDA-acceptability. The POC values underestimated lab reported glucose levels in 50 of 54 cases even with the use of same venous sample sent to the lab, which make it highly unreliable for use in monitoring suspected DKA patients.

  10. Clustering of reads with alignment-free measures and quality values.

    PubMed

    Comin, Matteo; Leoni, Andrea; Schimd, Michele

    2015-01-01

    The data volume generated by Next-Generation Sequencing (NGS) technologies is growing at a pace that is now challenging the storage and data processing capacities of modern computer systems. In this context an important aspect is the reduction of data complexity by collapsing redundant reads in a single cluster to improve the run time, memory requirements, and quality of post-processing steps like assembly and error correction. Several alignment-free measures, based on k-mers counts, have been used to cluster reads. Quality scores produced by NGS platforms are fundamental for various analysis of NGS data like reads mapping and error detection. Moreover future-generation sequencing platforms will produce long reads but with a large number of erroneous bases (up to 15 %). In this scenario it will be fundamental to exploit quality value information within the alignment-free framework. To the best of our knowledge this is the first study that incorporates quality value information and k-mers counts, in the context of alignment-free measures, for the comparison of reads data. Based on this principles, in this paper we present a family of alignment-free measures called D (q) -type. A set of experiments on simulated and real reads data confirms that the new measures are superior to other classical alignment-free statistics, especially when erroneous reads are considered. Also results on de novo assembly and metagenomic reads classification show that the introduction of quality values improves over standard alignment-free measures. These statistics are implemented in a software called QCluster (http://www.dei.unipd.it/~ciompin/main/qcluster.html).

  11. Measuring What People Value: A Comparison of “Attitude” and “Preference” Surveys

    PubMed Central

    Phillips, Kathryn A; Johnson, F Reed; Maddala, Tara

    2002-01-01

    Objective To compare and contrast methods and findings from two approaches to valuation used in the same survey: measurement of “attitudes” using simple rankings and ratings versus measurement of “preferences” using conjoint analysis. Conjoint analysis, a stated preference method, involves comparing scenarios composed of attribute descriptions by ranking, rating, or choosing scenarios. We explore possible explanations for our findings using focus groups conducted after the quantitative survey. Methods A self-administered survey, measuring attitudes and preferences for HIV tests, was conducted at HIV testing sites in San Francisco in 1999–2000 (n = 365, response rate=96 percent). Attitudes were measured and analyzed using standard approaches. Conjoint analysis scenarios were developed using a fractional factorial design and results analyzed using random effects probit models. We examined how the results using the two approaches were both similar and different. Results We found that “attitudes” and “preferences” were generally consistent, but there were some important differences. Although rankings based on the attitude and conjoint analysis surveys were similar, closer examination revealed important differences in how respondents valued price and attributes with “halo” effects, variation in how attribute levels were valued, and apparent differences in decision-making processes. Conclusions To our knowledge, this is the first study to compare attitude surveys and conjoint analysis surveys and to explore the meaning of the results using post-hoc focus groups. Although the overall findings for attitudes and preferences were similar, the two approaches resulted in some different conclusions. Health researchers should consider the advantages and limitations of both methods when determining how to measure what people value. PMID:12546291

  12. Mechanical device for determining the stiffness and the viscous friction coefficient of shock absorber elements modelled by bond graph

    NASA Astrophysics Data System (ADS)

    Ibănescu, R.; Ibănescu, M.

    2016-11-01

    The present paper presents a mechanical device for the assessment of the fundamental parameters of a shock absorber: the spring stiffness and the viscous friction coefficient, without disassembling the absorber. The device produces an oscillatory motion of the shock absorber and can measure its amplitude and angular velocities. The dynamic model of the system, consisting of the mechanical device and the shock absorber, is performed by using the bond- graph method. Based on this model, the motion equations are obtained, which by integration lead to the motion law. The two previously mentioned parameters are determined by using this law and the measured values of two amplitudes and of their corresponding angular velocities. They result as solutions of a system of two non-linear algebraic equations.

  13. Network analysis of surgical innovation: Measuring value and the virality of diffusion in robotic surgery

    PubMed Central

    Cingolani, Isabella; Panzarasa, Pietro; Darzi, Ara; Athanasiou, Thanos

    2017-01-01

    Background Existing surgical innovation frameworks suffer from a unifying limitation, their qualitative nature. A rigorous approach to measuring surgical innovation is needed that extends beyond detecting simply publication, citation, and patent counts and instead uncovers an implementation-based value from the structure of the entire adoption cascades produced over time by diffusion processes. Based on the principles of evidence-based medicine and existing surgical regulatory frameworks, the surgical innovation funnel is described. This illustrates the different stages through which innovation in surgery typically progresses. The aim is to propose a novel and quantitative network-based framework that will permit modeling and visualizing innovation diffusion cascades in surgery and measuring virality and value of innovations. Materials and methods Network analysis of constructed citation networks of all articles concerned with robotic surgery (n = 13,240, Scopus®) was performed (1974–2014). The virality of each cascade was measured as was innovation value (measured by the innovation index) derived from the evidence-based stage occupied by the corresponding seed article in the surgical innovation funnel. The network-based surgical innovation metrics were also validated against real world big data (National Inpatient Sample–NIS®). Results Rankings of surgical innovation across specialties by cascade size and structural virality (structural depth and width) were found to correlate closely with the ranking by innovation value (Spearman’s rank correlation coefficient = 0.758 (p = 0.01), 0.782 (p = 0.008), 0.624 (p = 0.05), respectively) which in turn matches the ranking based on real world big data from the NIS® (Spearman’s coefficient = 0.673;p = 0.033). Conclusion Network analysis offers unique new opportunities for understanding, modeling and measuring surgical innovation, and ultimately for assessing and comparing generative value between different

  14. Different top-down approaches to estimate measurement uncertainty of whole blood tacrolimus mass concentration values.

    PubMed

    Rigo-Bonnin, Raül; Blanco-Font, Aurora; Canalias, Francesca

    2018-05-08

    Values of mass concentration of tacrolimus in whole blood are commonly used by the clinicians for monitoring the status of a transplant patient and for checking whether the administered dose of tacrolimus is effective. So, clinical laboratories must provide results as accurately as possible. Measurement uncertainty can allow ensuring reliability of these results. The aim of this study was to estimate measurement uncertainty of whole blood mass concentration tacrolimus values obtained by UHPLC-MS/MS using two top-down approaches: the single laboratory validation approach and the proficiency testing approach. For the single laboratory validation approach, we estimated the uncertainties associated to the intermediate imprecision (using long-term internal quality control data) and the bias (utilizing a certified reference material). Next, we combined them together with the uncertainties related to the calibrators-assigned values to obtain a combined uncertainty for, finally, to calculate the expanded uncertainty. For the proficiency testing approach, the uncertainty was estimated in a similar way that the single laboratory validation approach but considering data from internal and external quality control schemes to estimate the uncertainty related to the bias. The estimated expanded uncertainty for single laboratory validation, proficiency testing using internal and external quality control schemes were 11.8%, 13.2%, and 13.0%, respectively. After performing the two top-down approaches, we observed that their uncertainty results were quite similar. This fact would confirm that either two approaches could be used to estimate the measurement uncertainty of whole blood mass concentration tacrolimus values in clinical laboratories. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  15. 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

    ... costs or selling values subsequent to the rate redetermination which reduce conversion value to less... 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...

  16. Reflection by absorbing periodically stratified media

    NASA Astrophysics Data System (ADS)

    Lekner, John

    2014-03-01

    Existing theory gives the optical properties of a periodically stratified medium in terms of a two by two matrix. This theory is valid also for absorbing media, because the matrix remains unimodular. The main effect of absorption is that the reflection (of either polarization) becomes independent of the number of periods N, and of the substrate properties, provided N exceeds a certain value which depends on the absorption. The s and p reflections are then given by simple formulae. The stop-band structure, which gives total reflection in bands of frequency and angle of incidence in the non-absorbing case, remains influential in weakly absorbing media, causing strong variations in reflectivity. The theory is applied to the frequency dependence of the normal-incidence reflectivity of a quarter-wave stack in which the high-index and low-index layers both absorb weakly. Analytical expressions are obtained for the frequency at which the reflectivity is maximum, the maximum reflectivity, and also for the reflectivity at the band edges of the stop band of the non-absorbing stack.

  17. Precision half-life measurement of 11C: The most precise mirror transition F t value

    NASA Astrophysics Data System (ADS)

    Valverde, A. A.; Brodeur, M.; Ahn, T.; Allen, J.; Bardayan, D. W.; Becchetti, F. D.; Blankstein, D.; Brown, G.; Burdette, D. P.; Frentz, B.; Gilardy, G.; Hall, M. R.; King, S.; Kolata, J. J.; Long, J.; Macon, K. T.; Nelson, A.; O'Malley, P. D.; Skulski, M.; Strauss, S. Y.; Vande Kolk, B.

    2018-03-01

    Background: The precise determination of the F t value in T =1 /2 mixed mirror decays is an important avenue for testing the standard model of the electroweak interaction through the determination of Vu d in nuclear β decays. 11C is an interesting case, as its low mass and small QE C value make it particularly sensitive to violations of the conserved vector current hypothesis. The present dominant source of uncertainty in the 11CF t value is the half-life. Purpose: A high-precision measurement of the 11C half-life was performed, and a new world average half-life was calculated. Method: 11C was created by transfer reactions and separated using the TwinSol facility at the Nuclear Science Laboratory at the University of Notre Dame. It was then implanted into a tantalum foil, and β counting was used to determine the half-life. Results: The new half-life, t1 /2=1220.27 (26 ) s, is consistent with the previous values but significantly more precise. A new world average was calculated, t1/2 world=1220.41 (32 ) s, and a new estimate for the Gamow-Teller to Fermi mixing ratio ρ is presented along with standard model correlation parameters. Conclusions: The new 11C world average half-life allows the calculation of a F tmirror value that is now the most precise value for all superallowed mixed mirror transitions. This gives a strong impetus for an experimental determination of ρ , to allow for the determination of Vu d from this decay.

  18. Anomalous weak values and the violation of a multiple-measurement Leggett-Garg inequality

    NASA Astrophysics Data System (ADS)

    Avella, Alessio; Piacentini, Fabrizio; Borsarelli, Michelangelo; Barbieri, Marco; Gramegna, Marco; Lussana, Rudi; Villa, Federica; Tosi, Alberto; Degiovanni, Ivo Pietro; Genovese, Marco

    2017-11-01

    Quantum mechanics presents peculiar properties that, on the one hand, have been the subject of several theoretical and experimental studies about its very foundations and, on the other hand, provide tools for developing new technologies, the so-called quantum technologies. The nonclassicality pointed out by Leggett-Garg inequalities has represented, with Bell inequalities, one of the most investigated subjects. In this article we study the connection of Leggett-Garg inequalities with a new emerging field of quantum measurement, the weak values in the case of a series of sequential measurements on a single object. In detail, we perform an experimental study of the four-time-correlator Leggett-Garg test, by exploiting single and sequential weak measurements performed on heralded single photons.

  19. Building the Infrastructure for Value at UCLA: Engaging Clinicians and Developing Patient-Centric Measurement.

    PubMed

    Clarke, Robin; Hackbarth, Andrew S; Saigal, Christopher; Skootsky, Samuel A

    2015-10-01

    Evolving payer and patient expectations have challenged academic health centers (AHCs) to improve the value of clinical care. Traditional quality approaches may be unable to meet this challenge. One AHC, UCLA Health, has implemented a systematic approach to delivery system redesign that emphasizes clinician engagement, a patient-centric scope, and condition-specific, clinician-guided measurement. A physician champion serves as quality officer (QO) for each clinical department/division. Each QO, with support from a central measurement team, has developed customized analytics that use clinical data to define targeted populations and measure care across the full treatment episode. From October 2012 through June 2015, the approach developed rapidly. Forty-three QOs are actively redesigning care delivery protocols within their specialties, and 95% of the departments/divisions have received a customized measure report for at least one patient population. As an example of how these analytics promote systematic redesign, the authors discuss how Department of Urology physicians have used these new measures, first, to better understand the relationship between clinical practice and outcomes for patients with benign prostatic hyperplasia and, then, to work toward reducing unwarranted variation. Physicians have received these efforts positively. Early outcome data are encouraging. This infrastructure of engaged physicians and targeted measurement is being used to implement systematic care redesign that reliably achieves outcomes that are meaningful to patients and clinicians-incorporating both clinical and cost considerations. QOs are using an approach, for multiple newly launched projects, to identify, test, and implement value-oriented interventions tailored to specific patient populations.

  20. 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. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. In-situ measurements of light-absorbing impurities in snow of glacier on Mt. Yulong and implications for radiative forcing estimates.

    PubMed

    Niu, Hewen; Kang, Shichang; Shi, Xiaofei; Paudyal, Rukumesh; He, Yuanqing; Li, Gang; Wang, Shijin; Pu, Tao; Shi, Xiaoyi

    2017-03-01

    The Tibetan Plateau (TP) or the third polar cryosphere borders geographical hotspots for discharges of black carbon (BC). BC and dust play important roles in climate system and Earth's energy budget, particularly after they are deposited on snow and glacial surfaces. BC and dust are two kinds of main light-absorbing impurities (LAIs) in snow and glaciers. Estimating concentrations and distribution of LAIs in snow and glacier ice in the TP is of great interest because this region is a global hotspot in geophysical research. Various snow samples, including surface aged-snow, superimposed ice and snow meltwater samples were collected from a typical temperate glacier on Mt. Yulong in the snow melt season in 2015. The samples were determined for BC, Organic Carbon (OC) concentrations using an improved thermal/optical reflectance (DRI Model 2001) method and gravimetric method for dust concentrations. Results indicated that the LAIs concentrations were highly elevation-dependent in the study area. Higher contents and probably greater deposition at relative lower elevations (generally <5000masl) of the glacier was observed. Temporal difference of LAIs contents demonstrated that LAIs in snow of glacier gradually increased as snow melting progressed. Evaluations of the relative absorption of BC and dust displayed that the impact of dust on snow albedo and radiative forcing (RF) is substantially larger than BC, particularly when dust contents are higher. This was verified by the absorption factor, which was <1.0. In addition, we found the BC-induced albedo reduction to be in the range of 2% to nearly 10% during the snow melting season, and the mean snow albedo reduction was 4.63%, hence for BC contents ranging from 281 to 894ngg -1 in snow of a typical temperate glacier on Mt. Yulong, the associated instantaneous RF will be 76.38-146.96Wm -2 . Further research is needed to partition LAIs induced glacial melt, modeling researches in combination with long-term in

  2. Presenting Cost and Efficiency Measures That Support Consumers to Make High-Value Health Care Choices.

    PubMed

    Greene, Jessica; Sacks, Rebecca M

    2018-02-25

    To identify approaches to presenting cost and resource use measures that support consumers in selecting high-value hospitals. Survey data were collected from U.S. employees of Analog Devices (n = 420). In two online experiments, participants viewed comparative data on four hospitals. In one experiment, participants were randomized to view one of five versions of the same comparative cost data, and in the other experiment they viewed different versions of the same readmissions data. Bivariate and multivariate analyses examined whether presentation approach was related to selecting the high-value hospital. Consumers were approximately 16 percentage points more likely to select a high-value hospital when cost data were presented using actual dollar amounts or using the word "affordable" to describe low-cost hospitals, compared to when the Hospital Compare spending ratio was used. Consumers were 33 points more likely to select the highest performing hospital when readmission performance was shown using word icons rather than percentages. Presenting cost and resource use measures effectively to consumers is challenging. This study suggests using actual dollar amounts for cost, but presenting performance on readmissions using evaluative symbols. © Health Research and Educational Trust.

  3. Standard values of maximum tongue pressure taken using newly developed disposable tongue pressure measurement device.

    PubMed

    Utanohara, Yuri; Hayashi, Ryo; Yoshikawa, Mineka; Yoshida, Mitsuyoshi; Tsuga, Kazuhiro; Akagawa, Yasumasa

    2008-09-01

    It is clinically important to evaluate tongue function in terms of rehabilitation of swallowing and eating ability. We have developed a disposable tongue pressure measurement device designed for clinical use. In this study we used this device to determine standard values of maximum tongue pressure in adult Japanese. Eight hundred fifty-three subjects (408 male, 445 female; 20-79 years) were selected for this study. All participants had no history of dysphagia and maintained occlusal contact in the premolar and molar regions with their own teeth. A balloon-type disposable oral probe was used to measure tongue pressure by asking subjects to compress it onto the palate for 7 s with maximum voluntary effort. Values were recorded three times for each subject, and the mean values were defined as maximum tongue pressure. Although maximum tongue pressure was higher for males than for females in the 20-49-year age groups, there was no significant difference between males and females in the 50-79-year age groups. The maximum tongue pressure of the seventies age group was significantly lower than that of the twenties to fifties age groups. It may be concluded that maximum tongue pressures were reduced with primary aging. Males may become weaker with age at a faster rate than females; however, further decreases in strength were in parallel for male and female subjects.

  4. Measuring the nose in septorhinoplasty patients: ultrasonographic standard values and clinical correlations.

    PubMed

    Stenner, Markus; Koopmann, Mario; Rudack, Claudia

    2017-02-01

    Although septorhinoplasty is the most commonly performed operation in plastic surgery, and the surgical plan as well as its outcome is directly related to the configuration of the anatomical structures in the nose, these are not routinely assessed preoperatively. The aim of our study was to evaluate the nasal soft tissue and cartilaginous structures by means of high-resolution ultrasonography to set up clinical correlations and standard values. We examined 44 patients before septorhinoplasty by high-resolution ultrasonography in noncontact mode. All pictures were quantitatively evaluated by measuring 13 lengths and 4 ratios. All patients underwent a rhinomanometry measuring the nasal air flow. Besides others, men as well as older patients have a significantly thicker alar cartilage. Patients with thinner alar cartilages have a significantly smaller interdomal distance as well as significantly thinner upper lateral cartilages. The soft tissue above the bony dorsum was significantly thicker in older patients. Younger patients have significantly thicker soft tissue in relation to their cartilage. Patients with thicker soft tissue and thinner cartilage have a smaller tip. The interdomal distance and the thickness of the cartilaginous septum significantly correlated with the nasal air flow. We set up standard values of nasal structures in septorhinoplasty patients which can be used as reference values. By judging cartilage and soft tissue characteristics preoperatively, relevant factors for distinct procedures could be analyzed and the surgical steps can be better planned. Visualization by ultrasonography enables the surgeon to achieve treatment goals in a more predictable fashion.

  5. The equivalence of two phylogenetic biodiversity measures: the Shapley value and Fair Proportion index.

    PubMed

    Hartmann, Klaas

    2013-11-01

    Most biodiversity conservation programs are forced to prioritise species in order to allocate their funding. This paper contains a mathematical proof that provides biological support for one common approach based on phylogenetic indices. Phylogenetic trees describe the evolutionary relationships between a group of taxa. Two indices for computing the distinctiveness of each taxon in a phylogenetic tree are considered here-the Shapley value and the Fair Proportion index. These indices provide a measure of the importance of each taxon for overall biodiversity and have been used to prioritise taxa for conservation. The Shapley value is the biodiversity contribution a taxon is expected to make if all taxa are equally likely to become extinct. This interpretation makes it appealing to use the Shapley value in biodiversity conservation applications. The Fair Proportion index lacks a convenient interpretation, however it is significantly easier to calculate and understand. It has been empirically observed that there is a high correlation between the two indices. This paper shows the mathematical basis for this correlation and proves that as the number of taxa increases, the indices become equivalent. Consequently in biodiversity prioritisation the simpler Fair Proportion index can be used whilst retaining the appealing interpretation of the Shapley value.

  6. Quality measures and pediatric radiology: suggestions for the transition to value-based payment.

    PubMed

    Heller, Richard E; Coley, Brian D; Simoneaux, Stephen F; Podberesky, Daniel J; Hernanz-Schulman, Marta; Robertson, Richard L; Donnelly, Lane F

    2017-06-01

    Recent political and economic factors have contributed to a meaningful change in the way that quality in health care, and by extension value, are viewed. While quality is often evaluated on the basis of subjective criteria, pay-for-performance programs that link reimbursement to various measures of quality require use of objective and quantifiable measures. This evolution to value-based payment was accelerated by the 2015 passage of the Medicare Access and CHIP (Children's Health Insurance Program) Reauthorization Act (MACRA). While many of the drivers of these changes are rooted in federal policy and programs such as Medicare and aimed at adult patients, the practice of pediatrics and pediatric radiology will be increasingly impacted. This article addresses issues related to the use of quantitative measures to evaluate the quality of services provided by the pediatric radiology department or sub-specialty section, particularly as seen from the viewpoint of a payer that may be considering ways to link payment to performance. The paper concludes by suggesting a metric categorization strategy to frame future work on the subject.

  7. Epidemiological, demographic, and economic analyses: measurement of the value of trichiasis surgery in The Gambia.

    PubMed

    Frick, K D; Keuffel, E L; Bowman, R J

    2001-07-01

    Untreated trichiasis can lead to corneal opacity. Surgery to prevent the eyelashes from rubbing against the cornea is available, but many individuals with trichiasis never undergo the operation. This study estimates the cost of illness of untreated trichiasis and the willingness to pay for surgery and compares them with the actual cost of providing surgery. The cost of illness estimate is based on trichiasis patient demographics. Data on the implicit price of obtaining surgery and surgical utilization in a matched pair randomized trial are used to infer individual willingness to pay for trichiasis surgery. Patients in the study paid nothing out-of-pocket for surgery; the price of obtaining surgery is the value of the individual's time needed for travel and surgery plus the price of public transportation. The cost of producing surgery was calculated from project records. All monetary figures are reported in 1998 US dollars. The average cost of untreated trichiasis, or the net present value of life-time lost economic productivity, was $89. Individuals facing a lower cost were more likely to undergo an operation; the inferred average willingness to pay was $1.43 (SD 0.244). Surgery cost $6.13 to provide, including $0.86 for transportation to the village. Whether the value of trichiasis surgery exceeds the cost in The Gambia depends on how the value is measured. Individuals are willing to use only limited resources to obtain surgery even though lifetime economic productivity may increase substantially. All three economic measures can be used to inform policy.

  8. Value-Added Measures of Education Performance: Clearing Away the Smoke and Mirrors. Policy Brief 10-4

    ERIC Educational Resources Information Center

    Harris, Douglas N.

    2010-01-01

    In this policy brief, the author explores the problems with attainment measures when it comes to evaluating performance at the school level, and explores the best uses of value-added measures. These value-added measures, the author writes, are useful for sorting out-of-school influences from school influences or from teacher performance, giving…

  9. 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.

  10. Mapping from disease-specific measures to health-state utility values in individuals with migraine.

    PubMed

    Gillard, Patrick J; Devine, Beth; Varon, Sepideh F; Liu, Lei; Sullivan, Sean D

    2012-05-01

    The objective of this study was to develop empirical algorithms that estimate health-state utility values from disease-specific quality-of-life scores in individuals with migraine. Data from a cross-sectional, multicountry study were used. Individuals with episodic and chronic migraine were randomly assigned to training or validation samples. Spearman's correlation coefficients between paired EuroQol five-dimensional (EQ-5D) questionnaire utility values and both Headache Impact Test (HIT-6) scores and Migraine-Specific Quality-of-Life Questionnaire version 2.1 (MSQ) domain scores (role restrictive, role preventive, and emotional function) were examined. Regression models were constructed to estimate EQ-5D questionnaire utility values from the HIT-6 score or the MSQ domain scores. Preferred algorithms were confirmed in the validation samples. In episodic migraine, the preferred HIT-6 and MSQ algorithms explained 22% and 25% of the variance (R(2)) in the training samples, respectively, and had similar prediction errors (root mean square errors of 0.30). In chronic migraine, the preferred HIT-6 and MSQ algorithms explained 36% and 45% of the variance in the training samples, respectively, and had similar prediction errors (root mean square errors 0.31 and 0.29). In episodic and chronic migraine, no statistically significant differences were observed between the mean observed and the mean estimated EQ-5D questionnaire utility values for the preferred HIT-6 and MSQ algorithms in the validation samples. The relationship between the EQ-5D questionnaire and the HIT-6 or the MSQ is adequate to use regression equations to estimate EQ-5D questionnaire utility values. The preferred HIT-6 and MSQ algorithms will be useful in estimating health-state utilities in migraine trials in which no preference-based measure is present. Copyright © 2012 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  11. 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

  12. Social value orientation: theoretical and measurement issues in the study of social preferences.

    PubMed

    Murphy, Ryan O; Ackermann, Kurt A

    2014-02-01

    What motivates people when they make decisions and how those motivations are potentially entangled with concerns for others are central topics for the social, cognitive, and behavioral sciences. According to the postulate of narrow self-interest, decision makers have the goal of maximizing personal payoffs and are wholly indifferent to the consequences for others. The postulate of narrow self-interest-which has been influential in economics, psychology, and sociology-is precise and powerful but is often simply wrong. Its inadequacy is well known and efforts have been made to develop reliable and valid measurement methods to quantify the more nuanced social preferences that people really have. In this paper, we report on the emergence and development of the predominant conceptualization of social preferences in psychology: social value orientation (SVO). Second, we discuss the relationship between measurement and theory development of the SVO construct. We then provide an overview of the literature regarding measurement methods that have been used to assess individual variations in social preferences. We conclude with a comparative evaluation of the various measures and provide suggestions regarding the measures' constructive use in building psychologically realistic theories of people's social preferences.

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

    PubMed

    O'Sullivan, Teresa A; Lau, Carmen; Patel, Mitul; Mac, Chi; Krueger, Janelle; Danielson, Jennifer; Weber, Stanley S

    2015-12-25

    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. 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. 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. 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.

  14. Challenges in measuring and valuing productivity costs, and their relevance in mood disorders

    PubMed Central

    Lensberg, Benedikte R; Drummond, Michael F; Danchenko, Natalya; Despiégel, Nicolas; François, Clément

    2013-01-01

    Lost productivity is often excluded from economic evaluations, which may lead to an underestimation of the societal benefits of treatment. However, there are multiple challenges in reliably estimating and reporting productivity losses. This article explores the main challenges, ie, selecting an appropriate valuation method (ie, human capital, friction cost, or multiplier), avoiding double counting, and accounting for equity. It also discusses the use of presenteeism instruments and their application in clinical trials, with a specific focus on their relevance in individuals with mood disorders. Further research and discussion is required on the development of reliable techniques for measuring and valuing productivity changes due to presenteeism. PMID:24273412

  15. Reference values of anthropometric measurements in Dutch children. The Oosterwolde Study.

    PubMed

    Gerver, W J; Drayer, N M; Schaafsma, W

    1989-03-01

    In the period 1979-1980 the following anthropometric measurements were recorded in 2351 healthy Dutch children from 0-17 years of age: height, weight, sitting height, arm span, lengths of upper-arm, lower-arm and hand, tibial length, foot length, biacromial diameter, biiliacal diameter, and head circumference. Corresponding percentile values were constructed on the basis of normality assumptions, the mean and standard deviation at age t being determined by a cubic spline approximation. The results are compared with other studies and given in the form of growth charts.

  16. Measurement of utility values in the UK for health states related to immune thrombocytopenic purpura.

    PubMed

    Szende, Agota; Brazier, John; Schaefer, Caroline; Deuson, Robert; Isitt, John J; Vyas, Paresh

    2010-08-01

    To measure utility values associated with immune (idiopathic) thrombocytopenic purpura (ITP), as perceived by the United Kingdom (UK) general public. A multi-step process, including clinical trial data, literature review, and patient focus group, was used to develop ITP health states valued in a web survey. Six ITP health states were defined based on platelet levels, risk of bleeding and key adverse events/disease complications. Clinical trial data on bleeding and ITP-specific quality of life data were key sources for developing health-state descriptions. 359 respondents, randomly selected from a managed web panel in the UK, completed the web-based Time Trade-Off survey. Wilcoxon signed-rank test was used to compare differences between each pair of health states. Sample characteristics (mean age: 47.9 +/- 16.9 years; 54% female) were comparable to the UK general population. ITP health states were valued as significantly worse than perfect health. Experiencing bleeding episodes was a more important driver than low platelet levels in valuing a health state to be worse. Substantial disutilities were associated with surviving an intracranial haemorrhage. Mean (SD) utility values for each ITP health state are: HS1: platelets >or=50 x 10(9)/L, no outpatient bleed: 0.863 +/- 0.15; HS2: platelets >or=50 x 10(9)/L, outpatient bleed: 0.734 +/- 0.19; HS3: platelets <50 x 10(9)/L, no outpatient bleed: 0.841 +/- 0.19; HS4: platelets <50 x 10(9)/L, outpatient bleed: 0.732 +/- 0.19; HS5: intracranial haemorrhage (2-6 months): 0.038 +/- 0.46; HS6: steroid treatment adverse events: 0.758 +/- 0.20. Potential limitations relate to web user population characteristics and lack of comparative testing of web-based TTO methods. Results provide evidence that the UK general population associate substantial loss of value living with ITP, suggesting an important role for new ITP treatments. Utility values based on these health states may be useful in future cost-effectiveness studies of

  17. 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.

  18. Online physician ratings fail to predict actual performance on measures of quality, value, and peer review.

    PubMed

    Daskivich, Timothy J; Houman, Justin; Fuller, Garth; Black, Jeanne T; Kim, Hyung L; Spiegel, Brennan

    2018-04-01

    Patients use online consumer ratings to identify high-performing physicians, but it is unclear if ratings are valid measures of clinical performance. We sought to determine whether online ratings of specialist physicians from 5 platforms predict quality of care, value of care, and peer-assessed physician performance. We conducted an observational study of 78 physicians representing 8 medical and surgical specialties. We assessed the association of consumer ratings with specialty-specific performance scores (metrics including adherence to Choosing Wisely measures, 30-day readmissions, length of stay, and adjusted cost of care), primary care physician peer-review scores, and administrator peer-review scores. Across ratings platforms, multivariable models showed no significant association between mean consumer ratings and specialty-specific performance scores (β-coefficient range, -0.04, 0.04), primary care physician scores (β-coefficient range, -0.01, 0.3), and administrator scores (β-coefficient range, -0.2, 0.1). There was no association between ratings and score subdomains addressing quality or value-based care. Among physicians in the lowest quartile of specialty-specific performance scores, only 5%-32% had consumer ratings in the lowest quartile across platforms. Ratings were consistent across platforms; a physician's score on one platform significantly predicted his/her score on another in 5 of 10 comparisons. Online ratings of specialist physicians do not predict objective measures of quality of care or peer assessment of clinical performance. Scores are consistent across platforms, suggesting that they jointly measure a latent construct that is unrelated to performance. Online consumer ratings should not be used in isolation to select physicians, given their poor association with clinical performance.

  19. Singular value description of a digital radiographic detector: Theory and measurements

    SciTech Connect

    Kyprianou, Iacovos S.; Badano, Aldo; Gallas, Brandon D.

    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 objectmore » 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

  20. Measuring striving for understanding and learning value of geometry: a validity study

    NASA Astrophysics Data System (ADS)

    Ubuz, Behiye; Aydınyer, Yurdagül

    2017-11-01

    The current study aimed to construct a questionnaire that measures students' personality traits related to striving for understanding and learning value of geometry and then examine its psychometric properties. Through the use of multiple methods on two independent samples of 402 and 521 middle school students, two studies were performed to address this issue to provide support for its validity. In Study 1, exploratory factor analysis indicated the two-factor model. In Study 2, confirmatory factor analysis indicated the better fit of two-factor model compared to one or three-factor model. Convergent and discriminant validity evidence provided insight into the distinctiveness of the two factors. Subgroup validity evidence revealed gender differences for striving for understanding geometry trait favouring girls and grade level differences for learning value of geometry trait favouring the sixth- and seventh-grade students. Predictive validity evidence demonstrated that the striving for understanding geometry trait but not learning value of geometry trait was significantly correlated with prior mathematics achievement. In both studies, each factor and the entire questionnaire showed satisfactory reliability. In conclusion, the questionnaire was psychometrically sound.

  1. 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%).

  2. Evaluation of variations in absorbed dose and image noise according to patient forms in X-ray computed tomography.

    PubMed

    Matsubara, Kosuke; Koshida, Kichiro; Suzuki, Masayuki; Hayakawa, Mayumi; Tsujii, Hideo; Yamamoto, Tomoyuki

    2005-12-20

    Excessive radiation exposure in pediatric computed tomography (CT) scanning has become a serious problem, and it is difficult to select scan parameters for the scanning of small patients such as children. We investigated differences in absorbed dose and standard deviation (SD) in Hounsfield unit (HU) caused by differences in the form of the subject using a body-type phantom with removable body parts. Using four X-ray CT scanners, measurements were made with values from 50 mAs to 300 mAs, with slices of 50 mAs, using scan protocols that were assumed to perform thorough examinations. The results showed that the mAs values and absorbed doses were almost proportional, and the absorbed doses in the phantom without body parts were about 1.1-2.2-fold higher than those of the phantom with body parts at the same points. The SD values obtained indicated that the absorbed doses in the phantom with body parts were 0.3-0.6 times those of the phantom without body parts when the mAs values used were adjusted so that both SD values were the same. The absorbed doses in various patient forms can be estimated from these results, and they will become critical data for the selection of appropriate scan protocols.

  3. Properties of CGM-Absorbing Galaxies

    NASA Astrophysics Data System (ADS)

    Hamill, Colin; Conway, Matthew; Apala, Elizabeth; Scott, Jennifer

    2018-01-01

    We extend the results of a study of the sightlines of 45 low-redshift quasars (0.06 < z < 0.85) observed by HST/COS that lie within the Sloan Digital Sky Survey. We have used photometric data from the SDSS DR12, along with the known absorption characteristics of the intergalactic medium and circumgalactic medium, to identify the most probable galaxy matches to absorbers in the spectroscopic dataset. Here, we use photometric data and measured galaxy parameters from SDSS DR12 to examine the distributions of galaxy properties such as virial radius, morphology, and position angle among those that match to absorbers within a specific range of impact parameters. We compare those distributions to galaxies within the same impact parameter range that are not matched to any absorber in the HST/COS spectrum in order to investigate global properties of the circumgalactic medium.

  4. A wideband absorber for television studios

    NASA Astrophysics Data System (ADS)

    Baird, M. D. M.

    The acoustic treatment in BBC television has taken various forms to date, all of which have been relatively expensive, some of which provide inadequate absorption. An investigation has been conducted into the possibilities of producing a new type of wideband absorber which would be more economic, also taking installation time into account, than earlier designs. This Report describes the absorption coefficient measurements made on various combinations of materials, from which a wideband sound absorber has been developed. The absorber works efficiently between 50 Hz and 10 kHz, is simple and easy to construct using readily available materials, and is fire resistant. The design lends itself, if necessary, to on-site fine tuning, and savings in the region of 50 percent can be achieved in terms of cost and space with respect to previous designs.

  5. Value-based neurosurgery: measuring and reducing the cost of microvascular decompression surgery.

    PubMed

    McLaughlin, Nancy; Upadhyaya, Pooja; Buxey, Farzad; Martin, Neil A

    2014-09-01

    Care providers have put significant effort into optimizing patient safety and quality of care. Value, defined as meaningful outcomes achieved per dollar spent, is emerging as a promising framework to redesign health care. Scarce data exist regarding cost measurement and containment for episodes of neurosurgical care. The authors assessed how cost measurement and strategic containment could be used to optimize the value of delivered care after the implementation and maturation of quality improvement initiatives. A retrospective study of consecutive patients undergoing microvascular decompression was performed. Group 1 comprised patients treated prior to the implementation of quality improvement interventions, and Group 2 consisted of those treated after the implementation and maturation of quality improvement processes. A third group, Group 3, represented a contemporary group studied after the implementation of cost containment interventions targeting the three most expensive activities: pre-incision time in the operating room (OR) and total OR time, intraoperative neuromonitoring (IOM), and bed assignment (and overall length of stay [LOS]). The value of care was assessed for all three groups. Forty-four patients were included in the study. Average preparation time pre-incision decreased from 73 to 65 to 45 minutes in Groups 1, 2, and 3, respectively. The average total OR time and OR cost were 434 minutes and $8513 in Group 1; 348 minutes and $7592 in Group 2; and 407 minutes and $8333 in Group 3. The average cost for IOM, excluding electrode needles, was $1557, $1585, and $1263, respectively, in Groups 1, 2, and 3. Average total cost for bed assignment was $5747, $5198, and $4535, respectively, in Groups 1, 2, and 3. The average total LOS decreased from 3.16 days in Group 1 to 2.14 days in Group 3. Complete relief of or a significant decrease in preoperative symptomatology was achieved in 42 of the 44 patients, respectively. Overall, the average cost of a surgical

  6. 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.

  7. Measurement of cochlear length using the 'A' value for cochlea basal diameter: A feasibility study.

    PubMed

    Deep, Nicholas L; Howard, Brittany E; Holbert, Sarah O; Hoxworth, Joseph M; Barrs, David M

    2017-07-01

    To determine whether the cochlea basal diameter (A value) measurement can be consistently and precisely obtained from high-resolution temporal bone imaging for use in cochlear length estimation. A feasibility study at a tertiary referral center was performed using the temporal bone CTs of 40 consecutive patients. The distance from the round window to the lateral wall was measured for each cochlea by two independent reviewers, a neuroradiologist and an otolaryngologist. The interrater reliability was calculated using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. Forty patients (19 males, 21 females) for a total of 80 cochleae were included. Interrater reliability on the same ear had a high level of agreement by both the ICC and the Bland-Altman plot. ICCs were 0.90 (95% CI: 0.82, 0.94) for the left ear and 0.96 (95% CI: 0.92, 0.98) for the right ear. Bland-Altman plot confirmed interrater reliability with all 96% of measurements falling within the 95% limits of agreement. Measurement between the round window and lateral cochlear wall can be consistently and reliably obtained from high-resolution temporal bone CT scans. Thus, it is feasible to utilize this method to estimate the cochlear length of patients undergoing cochlear implantation.

  8. Value of in vivo electrophysiological measurements to evaluate canine small bowel autotransplants.

    PubMed Central

    Meijssen, M A; Heineman, E; de Bruin, R W; Veeze, H J; Bijman, J; de Jonge, H R; ten Kate, F J; Marquet, R L; Molenaar, J C

    1991-01-01

    This study aimed to develop a non-invasive method for in vivo measurement of the transepithelial potential difference in the canine small bowel and to evaluate this parameter in small bowel autotransplants. In group 0 (control group, n = 4), two intestinal loops were created without disturbing their vascular, neural, and lymphatic supplies. In group I (successful autotransplants, n = 11), two heterotopic small bowel loops were constructed. Long term functional sequelae of vascular, neural, and lymphatic division were studied. Group II (n = 6) consisted of dogs with unsuccessful autotransplants suffering thrombosis of the vascular anastomosis, which resulted in ischaemic small bowel autografts. In group I, values of spontaneous transepithelial potential difference, an index of base line active electrolyte transport, were significantly lower compared with group 0 (p less than 0.05), probably as a result of denervation of the autotransplants. Both theophylline and glucose stimulated potential difference responses, measuring cyclic adenosine monophosphate mediated chloride secretion and sodium coupled glucose absorption respectively, showed negative luminal values in group I at all time points after transplantation. These transepithelial potential difference responses diminished progressively with time. From day 21 onwards both theophylline and glucose stimulated potential difference responses were significantly less than the corresponding responses at day seven (p less than 0.05). Morphometric analysis showed that the reduction of transepithelial potential difference responses preceded degenerative mucosal changes in the heterotopic small bowel autografts. In group II, potential difference responses to theophylline and glucose showed positive luminal values (p<0.01 v group I), probably as a result of passive potassium effusion from necrotic enterocytes. Images Figure 3 PMID:1752464

  9. 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

  10. 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…

  11. 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...

  12. Variability in objective and subjective measures affects baseline values in studies of patients with COPD

    PubMed Central

    Ha, Jae Wook; Couper, David J.; O’Neal, Wanda K.; Barr, R. Graham; Bleecker, Eugene R.; Carretta, Elizabeth E.; Cooper, Christopher B.; Doerschuk, Claire M.; Drummond, M Bradley; Han, MeiLan K.; Hansel, Nadia N.; Kim, Victor; Kleerup, Eric C.; Martinez, Fernando J.; Rennard, Stephen I.; Tashkin, Donald; Woodruff, Prescott G.; Paine, Robert; Curtis, Jeffrey L.; Kanner, Richard E.

    2017-01-01

    Rationale Understanding the reliability and repeatability of clinical measurements used in the diagnosis, treatment and monitoring of disease progression is of critical importance across all disciplines of clinical practice and in clinical trials to assess therapeutic efficacy and safety. Objectives Our goal is to understand normal variability for assessing true changes in health status and to more accurately utilize this data to differentiate disease characteristics and outcomes. Methods Our study is the first study designed entirely to establish the repeatability of a large number of instruments utilized for the clinical assessment of COPD in the same subjects over the same period. We utilized SPIROMICS participants (n = 98) that returned to their clinical center within 6 weeks of their baseline visit to repeat complete baseline assessments. Demographics, spirometry, questionnaires, complete blood cell counts (CBC), medical history, and emphysema status by computerized tomography (CT) imaging were obtained. Results Pulmonary function tests (PFTs) were highly repeatable (ICC’s >0.9) but the 6 minute walk (6MW) was less so (ICC = 0.79). Among questionnaires, the Saint George’s Respiratory Questionnaire (SGRQ) was most repeatable. Self-reported clinical features, such as exacerbation history, and features of chronic bronchitis, often produced kappa values <0.6. Reported age at starting smoking and average number of cigarettes smoked were modestly repeatable (kappa = 0.76 and 0.79). Complete blood counts (CBC) variables produced intraclass correlation coefficients (ICC) values between 0.6 and 0.8. Conclusions PFTs were highly repeatable, while subjective measures and subject recall were more variable. Analyses using features with poor repeatability could lead to misclassification and outcome errors. Hence, care should be taken when interpreting change in clinical features based on measures with low repeatability. Efforts to improve repeatability of key clinical

  13. The calibration of plane parallel ionisation chambers for the measurement of absorbed dose in electron beams of low to medium energies. Part 2: The PTW/MARKUS chamber.

    PubMed

    Cross, P; Freeman, N

    1997-06-01

    The purpose of Part 2 study of calibration methods for plane parallel ionisation chambers was to determine the feasibility of using beams of calibration of the MARKUS chamber other than the standard AAPM TG39 reference beams of 60Co and a high energy electron beam (E0 > or = 15 MeV). A previous study of the NACP chamber had demonstrated an acceptable level of accuracy with corresponding spread of -0.5% to +0.8% for its calibration in non-standard situations (medium to low energy electron and photon beams). For non-standard situations the spread in NDMARKUS values was found to be +/-2.5%. The results suggest that user calibrations of the MARKUS chamber in non-standard situations are associated with more uncertainties than is the case with the NACP chamber.

  14. Direct comparison of neutral velocity distribution measurements and simulations in the vicinity of an absorbing boundary oblique to a magnetic field

    NASA Astrophysics Data System (ADS)

    Henriquez, Miguel F.; Thompson, Derek S.; Keniley, Shane; Curreli, Davide; Steinberger, Thomas E.; Caron, David D.; Jemiolo, Andrew J.; McLaughlin, Jacob W.; Dufor, Mikal T.; Neal, Luke A.; Scime, Earl E.; Siddiqui, M. Umair

    2017-10-01

    Plasma-boundary interactions are strongly affected by the sheath and presheath structures that form near the boundary surface. Recent measurements have observed ion transport across magnetic field lines in regions where the surface is oblique to the background magnetic field (ψ =74°) . In these boundary regions, charge exchange collisions may provide a mechanism through which neutral particles interact with the long distance presheath electric field. We report efforts to directly compare Boltzmann and particle-in-cell simulations with 3D neutral velocity distribution functions (NVDFs) using laser induced fluorescence (LIF) in a magnetized plasma boundary region. We present a novel LIF method for measuring Ar-II metastable velocity distributions, in which we observe the 738.6014 nm fluorescence (2p3 to 1s4 in Paschen's notation), that results from absorption of the 706.9167 nm (1s5 metastable to 2p3) pump laser, providing neutral temperatures and flows. We additionally describe electrostatic probe measurements in the same region.

  15. A novel scoring system to measure radiographic abnormalities and related spirometric values in cured pulmonary tuberculosis.

    PubMed

    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

    Despite chemotherapy, patients with cured pulmonary tuberculosis may result in lung functional impairment. To evaluate a novel scoring system based on the degree of radiographic abnormalities and related spirometric values in patients with cured pulmonary tuberculosis. 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. 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. The extent of radiographic abnormalities, as evaluated through our novel scoring system, was inversely associated with spirometric values, and exhibited good reliability and reproducibility. As intra

  16. 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

  17. Lumbar lordosis and sacral slope in lumbar spinal stenosis: standard values and measurement accuracy.

    PubMed

    Bredow, J; Oppermann, J; Scheyerer, M J; Gundlfinger, K; Neiss, W F; Budde, S; Floerkemeier, T; Eysel, P; Beyer, F

    2015-05-01

    Radiological study. To asses standard values, intra- and interobserver reliability and reproducibility of sacral slope (SS) and lumbar lordosis (LL) and the correlation of these parameters in patients with lumbar spinal stenosis (LSS). Anteroposterior and lateral X-rays of the lumbar spine of 102 patients with LSS were included in this retrospective, radiologic study. Measurements of SS and LL were carried out by five examiners. Intraobserver correlation and correlation between LL and SS were calculated with Pearson's r linear correlation coefficient and intraclass correlation coefficients (ICC) were calculated for inter- and intraobserver reliability. In addition, patients were examined in subgroups with respect to previous surgery and the current therapy. Lumbar lordosis averaged 45.6° (range 2.5°-74.9°; SD 14.2°), intraobserver correlation was between Pearson r = 0.93 and 0.98. The measurement of SS averaged 35.3° (range 13.8°-66.9°; SD 9.6°), intraobserver correlation was between Pearson r = 0.89 and 0.96. Intraobserver reliability ranged from 0.966 to 0.992 ICC in LL measurements and 0.944-0.983 ICC in SS measurements. There was an interobserver reliability ICC of 0.944 in LL and 0.990 in SS. Correlation between LL and SS averaged r = 0.79. No statistically significant differences were observed between the analyzed subgroups. Manual measurement of LL and SS in patients with LSS on lateral radiographs is easily performed with excellent intra- and interobserver reliability. Correlation between LL and SS is very high. Differences between patients with and without previous decompression were not statistically significant.

  18. Valuing urban open space using the travel-cost method and the implications of measurement error.

    PubMed

    Hanauer, Merlin M; Reid, John

    2017-08-01

    Urbanization has placed pressure on open space within and adjacent to cities. In recent decades, a greater awareness has developed to the fact that individuals derive multiple benefits from urban open space. Given the location, there is often a high opportunity cost to preserving urban open space, thus it is important for both public and private stakeholders to justify such investments. The goals of this study are twofold. First, we use detailed surveys and precise, accessible, mapping methods to demonstrate how travel-cost methods can be applied to the valuation of urban open space. Second, we assess the degree to which typical methods of estimating travel times, and thus travel costs, introduce bias to the estimates of welfare. The site we study is Taylor Mountain Regional Park, a 1100-acre space located immediately adjacent to Santa Rosa, California, which is the largest city (∼170,000 population) in Sonoma County and lies 50 miles north of San Francisco. We estimate that the average per trip access value (consumer surplus) is $13.70. We also demonstrate that typical methods of measuring travel costs significantly understate these welfare measures. Our study provides policy-relevant results and highlights the sensitivity of urban open space travel-cost studies to bias stemming from travel-cost measurement error. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. 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.

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

    SciTech Connect

    Younkin, K; Long, CN

    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 casemore » 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.« less

  1. 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.

  2. 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.

  3. Effect of sampling location on L* values and pH measurements and their relationship in broiler breast fillets

    USDA-ARS?s Scientific Manuscript database

    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...

  4. The Math–Biology Values Instrument: Development of a Tool to Measure Life Science Majors’ Task Values of Using Math in the Context of Biology

    PubMed Central

    Andrews, Sarah E.; Runyon, Christopher; Aikens, Melissa L.

    2017-01-01

    In response to calls to improve the quantitative training of undergraduate biology students, there have been increased efforts to better integrate math into biology curricula. One challenge of such efforts is negative student attitudes toward math, which are thought to be particularly prevalent among biology students. According to theory, students’ personal values toward using math in a biological context will influence their achievement and behavioral outcomes, but a validated instrument is needed to determine this empirically. We developed the Math–Biology Values Instrument (MBVI), an 11-item college-level self-­report instrument grounded in expectancy-value theory, to measure life science students’ interest in using math to understand biology, the perceived usefulness of math to their life science career, and the cost of using math in biology courses. We used a process that integrates multiple forms of validity evidence to show that scores from the MBVI can be used as a valid measure of a student’s value of math in the context of biology. The MBVI can be used by instructors and researchers to help identify instructional strategies that influence math–biology values and understand how math–biology values are related to students’ achievement and decisions to pursue more advanced quantitative-based courses. PMID:28747355

  5. Wideband Aural Acoustic Absorbance Predicts Conductive Hearing Loss in Children

    PubMed Central

    Keefe, Douglas H.; Sanford, Chris A.; Ellison, John C.; Fitzpatrick, Denis F.; Gorga, Michael P.

    2013-01-01

    Objective This study tested the hypothesis that wideband aural absorbance predicts conductive hearing loss (CHL) in children medically classified as having otitis media with effusion. Design Absorbance was measured in the ear canal over frequencies from 0.25 to 8 kHz at ambient pressure or as a swept tympanogram. CHL was defined using criterion air-bone gaps of 20, 25 and 30 dB at octaves from 0.25 to 4 kHz. A likelihood-ratio predictor of CHL was constructed across frequency for ambient absorbance and across frequency and pressure for absorbance tympanometry. Performance was evaluated at individual frequencies and for any frequency at which a CHL was present. Study Sample Absorbance and conventional 226-Hz tympanograms were measured in children of age 3 to 8 years with CHL and with normal hearing. Results Absorbance was smaller at frequencies above 0.7 kHz in the CHL group than the control group. Based on the area under the receiver operating characteristic curve, wideband absorbance in ambient and tympanometric tests were significantly better predictors of CHL than tympanometric width, the best 226-Hz predictor. Accuracies of ambient and tympanometric wideband absorbance did not differ. Conclusions Absorbance accurately predicted CHL in children and was more accurate than conventional 226-Hz tympanometry. PMID:23072655

  6. 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.

  7. 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.

  8. Development and testing of an instrument to measure holistic nursing values in nurse practitioner care.

    PubMed

    Kinchen, Elizabeth

    2015-01-01

    As primary care delivery evolves in the United States with nurse practitioners (NPs) as key providers, exploring the patient's perception of the nature and quality of NPs' care is of critical importance to healthcare consumers, providers, educators, policy makers, and underwriters. The aim of this study was to describe the development and testing of the Nurse Practitioner Holistic Caring Instrument, a new, investigator-developed measure of the preservation of holistic nursing values in NP care. Results suggest that NPs provide patient-centered, comprehensive, and clinically competent care, rendering them ideally suited to leading primary health care delivery. However, further testing in more diverse populations and settings is needed to strengthen preliminary findings.

  9. Prognostic value of repeated serum CA 125 measurements in first trimester pregnancy.

    PubMed

    Schmidt, T; Rein, D T; Foth, D; Eibach, H W; Kurbacher, C M; Mallmann, P; Römer, T

    2001-08-01

    To assess the diagnostic value of maternal CA 125 in patients with symptomatic first trimester pregnancy and to evaluate the prognostic significance of CA 125 versus beta-hCG in early pregnancies with intact fetal heartbeat, complicated by vaginal bleeding. Two prospective open-label studies with longitudinal follow-up in the second trial. Academic Department of Obstetrics and Gynecology, University of Cologne. Study 1: 168 patients presenting between gestational weeks 6 and 12 with: extrauterine pregnancy, 29; missed abortion, 50; incomplete spontaneous abortion, 38; imminent abortion, 33; and normal pregnancy (no history of endometriosis or ovarian mass), 18. Study 2: Fifty consecutive patients with vaginal bleeding during gestational weeks 6-12 all of whom having demostrable fetal heartbeat. Eighteen patients finally aborted whereas the remainder had normally continuing pregnancy until term. Study 1: Single serum determinations of CA 125 and beta-hCG were correlated with the different disorders observed. Study 2: Two sequential measurements of serum CA 125 and beta-hCG performed within a 5-7 days interval were related to the outcome of pregnancy as indicated by changes of the ultrasound presentation, miscarriage, future hospitalization, or delivery. Study 1: Patients with vaginal bleeding generally had higher median CA 125 values (38 IU/ml; range 1.3-540) compared to non-bleeding patients (17.8 IU/ml; range 1.0-157). No statistically significant differences in regard to median serum CA 125 levels between symptomatic and normal pregnancies occurred: normal pregnancy, 25.5 IU/ml (range 3.2-97); ectopic pregnancy, 26 IU/ml (range 1.3-157); missed abortion, 19.1IU/ml (range 1-242); threatened abortion, 48 IU/ml (range 5.2-540); spontaneous abortion, 40 IU/ml (range 5.4-442). Study 2: Initial CA 125 levels did not differ significantly between both groups of patients with 27/32 non-aborters and 13/18 aborters showing concentrations below 65 IU/ml. After 5-7 days, CA

  10. 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.

  11. The public health value of vaccines beyond efficacy: methods, measures and outcomes.

    PubMed

    Wilder-Smith, A; Longini, I; Zuber, P L; Bärnighausen, T; Edmunds, W J; Dean, N; Spicher, V Masserey; Benissa, M R; Gessner, B D

    2017-07-26

    Assessments of vaccine efficacy and safety capture only the minimum information needed for regulatory approval, rather than the full public health value of vaccines. Vaccine efficacy provides a measure of proportionate disease reduction, is usually limited to etiologically confirmed disease, and focuses on the direct protection of the vaccinated individual. Herein, we propose a broader scope of methods, measures and outcomes to evaluate the effectiveness and public health impact to be considered for evidence-informed policymaking in both pre- and post-licensure stages. Pre-licensure: Regulatory concerns dictate an individually randomised clinical trial. However, some circumstances (such as the West African Ebola epidemic) may require novel designs that could be considered valid for licensure by regulatory agencies. In addition, protocol-defined analytic plans for these studies should include clinical as well as etiologically confirmed endpoints (e.g. all cause hospitalisations, pneumonias, acute gastroenteritis and others as appropriate to the vaccine target), and should include vaccine-preventable disease incidence and 'number needed to vaccinate' as outcomes. Post-licensure: There is a central role for phase IV cluster randomised clinical trials that allows for estimation of population-level vaccine impact, including indirect, total and overall effects. Dynamic models should be prioritised over static models as the constant force of infection assumed in static models will usually underestimate the effectiveness and cost-effectiveness of the immunisation programme by underestimating indirect effects. The economic impact of vaccinations should incorporate health and non-health benefits of vaccination in both the vaccinated and unvaccinated populations, thus allowing for estimation of the net social value of vaccination. The full benefits of vaccination reach beyond direct prevention of etiologically confirmed disease and often extend across the life course of a

  12. 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,…

  13. Metamaterial Absorber Based Multifunctional Sensor Application

    NASA Astrophysics Data System (ADS)

    Ozer, Z.; Mamedov, A. M.; Ozbay, E.

    2017-02-01

    In this study metamaterial based (MA) absorber sensor, integrated with an X-band waveguide, is numerically and experimentally suggested for important application including pressure, density sensing and marble type detecting applications based on rectangular split ring resonator, sensor layer and absorber layer that measures of changing in the dielectric constant and/or the thickness of a sensor layer. Changing of physical, chemical or biological parameters in the sensor layer can be detected by measuring the resonant frequency shifting of metamaterial absorber based sensor. Suggested MA based absorber sensor can be used for medical, biological, agricultural and chemical detecting applications in microwave frequency band. We compare the simulation and experimentally obtained results from the fabricated sample which are good agreement. Simulation results show that the proposed structure can detect the changing of the refractive indexes of different materials via special resonance frequencies, thus it could be said that the MA-based sensors have high sensitivity. Additionally due to the simple and tiny structures it could be adapted to other electronic devices in different sizes.

  14. Reference values of MRI measurements of the common bile duct and pancreatic duct in children.

    PubMed

    Gwal, Kriti; Bedoya, Maria A; Patel, Neal; Rambhatla, Siri J; Darge, Kassa; Sreedharan, Ram R; Anupindi, Sudha A

    2015-07-01

    the axial measurement was 2.0 mm; the mean coronal measurement of the pancreatic duct was 0.9 mm and the axial measurement was 0.8 mm. Our study provides normative measurements for the common bile duct and pancreatic duct for children up to age 10 years. The upper limits of the CBD and pancreatic duct increase with age, and the values range 1.1-4.0 mm for the CBD and 0.6-1.9 mm for the pancreatic duct.

  15. Diagnostic value of different adherence measures using electronic monitoring and virologic failure as reference standards.

    PubMed

    Deschamps, Ann E; De Geest, Sabina; Vandamme, Anne-Mieke; Bobbaers, Herman; Peetermans, Willy E; Van Wijngaerden, Eric

    2008-09-01

    Nonadherence to antiretroviral therapy is a substantial problem in HIV and jeopardizes the success of treatment. Accurate measurement of nonadherence is therefore imperative for good clinical management but no gold standard has been agreed on yet. In a single-center prospective study nonadherence was assessed by electronic monitoring: percentage of doses missed and drug holidays and by three self reports: (1) a visual analogue scale (VAS): percentage of overall doses taken; (2) the Swiss HIV Cohort Study Adherence Questionnaire (SHCS-AQ): percentage of overall doses missed and drug holidays and (3) the European HIV Treatment Questionnaire (EHTQ): percentage of doses missed and drug holidays for each antiretroviral drug separately. Virologic failure prospectively assessed during 1 year, and electronic monitoring were used as reference standards. Using virologic failure as reference standard, the best results were for (1) the SHCS-AQ after electronic monitoring (sensitivity, 87.5%; specificity, 78.6%); (2) electronic monitoring (sensitivity, 75%; specificity, 85.6%), and (3) the VAS combined with the SHCS-AQ before electronic monitoring (sensitivity, 87.5%; specificity, 58.6%). The sensitivity of the complex EHTQ was less than 50%. Asking simple questions about doses taken or missed is more sensitive than complex questioning about each drug separately. Combining the VAS with the SHCS-AQ seems a feasible nonadherence measure for daily clinical practice. Self-reports perform better after electronic monitoring: their diagnostic value could be lower when given independently.

  16. Radar Absorbing Material Design

    DTIC Science & Technology

    2003-09-01

    layer will depend on the angle of the incidence of the incoming wave. However, for large and ε µ values, the direction of the refracted ray in the...1995. 3. Federation of American Scientist Official Website (www.fas.org), 22 June 2003. 4. Asoke Bhattacharyya, D.L. Sengupta, Radar Cross Section

  17. [Clinical value of serum presepsin (SCD14-ST) concentration measurement in patients with pesticide poisoning].

    PubMed

    Gao, X; Zhu, B Y; Wang, W Z; He, J Q; Han, D L; Liu, Y J; Meng, H; Xiao, Q M; Liu, X T; Han, Y Y

    2016-05-20

    To investigate the value of serum presepsin concentration measurement in the clinical diagnosis and treatment of patients with pesticide poisoning patients. A total of 160 patients with pesticide poisoning were enrolled as study subjects and divided into moderate organophosphate pesticide poisoning group (40 patients) , severe organophosphate pesticide poisoning group (40 patients) , abamectin pesticide poisoning group (40 patients) , and paraquat poisoning group (40 patients). A total of 20 healthy volunteers were enrolled as the control group. All the patients with poisoning received conventional treatment of pesticide poisoning immediately after admission, and serum presepsin concentration was measured on days 1 (within 24 hours after poisoning) , 3, and 7 of admission, and biochemical and radiological parameters related to the patient's condition were also examined. The patients with a Presepsin concentration of >800 pg/ml on day 1 of admission were randomly divided into conventional treatment group and ulinastatin treatment group, and the treatment outcome was compared between the two groups. Compared with the healthy control group, the groups with pesticide poisoning showed significant increases in serum Presepsin concentrations, with the highest degree of increase on day 1 (P <0.05). The serum Presepsin concentration was positively correlated with alanine aminotransferase, aspartate aminotransferase, creatine kinase, creatine kinase MB, lactate dehydrogenase, serum creatinine, blood urea nitrogen, interleukin-18, and white blood cell count, but negatively correlated with cholinesterase. In the conventional treatment group and ulinastatin treatment group, the overall response rate was 68% and 78.8%, respectively, with a significant difference between the two groups (P<0.05). In 40 patients with paraquat poisoning, 32 experienced an increase in serum presepsin concentration, and among these 32 patients, 27 (83%) experienced exudation on lung CT. Serum

  18. Measuring the Value of the Hubble Constant “à la Refsdal”

    NASA Astrophysics Data System (ADS)

    Grillo, C.; Rosati, P.; Suyu, S. H.; Balestra, I.; Caminha, G. B.; Halkola, A.; Kelly, P. L.; Lombardi, M.; Mercurio, A.; Rodney, S. A.; Treu, T.

    2018-06-01

    Realizing Refsdal’s original idea from 1964, we present estimates of the Hubble constant that are complementary to, and potentially competitive with, those of other cosmological probes. We use the observed positions of 89 multiple images, with extensive spectroscopic information, from 28 background sources and the measured time delays between the images S1–S4 and SX of supernova “Refsdal” (z = 1.489), which were obtained thanks to Hubble Space Telescope deep imaging and Multi Unit Spectroscopic Explorer data. We extend the strong-lensing modeling of the Hubble Frontier Fields galaxy cluster MACS J1149.5+2223 (z = 0.542), published by Grillo et al. (2016), and explore different ΛCDM models. Taking advantage of the lensing information associated to the presence of very close pairs of multiple images at various redshifts, and to the extended surface brightness distribution of the SN Refsdal host, we can reconstruct the total mass-density profile of the cluster very precisely. The combined dependence of the multiple-image positions and time delays on the cosmological parameters allows us to infer the values of H 0 and Ωm with relative (1σ) statistical errors of, respectively, 6% (7%) and 31% (26%) in flat (general) cosmological models, assuming a conservative 3% uncertainty on the final time delay of image SX and, remarkably, no priors from other cosmological experiments. Our best estimate of H 0, based on the model described in this work, will be presented when the final time-delay measurement becomes available. Our results show that it is possible to utilize time delays in lens galaxy clusters as an important alternative tool for measuring the expansion rate and the geometry of the universe.

  19. 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.

  20. 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.

    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 validatedmore » 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

  1. 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

  2. Self-Regulating Shock Absorber

    NASA Technical Reports Server (NTRS)

    Wesselski, Clarence J.

    1995-01-01

    Mechanical shock absorber keeps frictional damping force within tolerable limit. Its damping force does not increase with coefficient of friction between energy-absorbing components; rather, frictional damping force varies only slightly. Relatively insensitive to manufacturing variations and environmental conditions altering friction. Does not exhibit high breakaway friction and consequent sharp increase followed by sharp decrease in damping force at beginning of stroking. Damping force in absorber does not vary appreciably with speed of stroking. In addition, not vulnerable to leakage of hydraulic fluid.

  3. The Value of Body Weight Measurement to Assess Dehydration in Children

    PubMed Central

    Pruvost, Isabelle; Dubos, François; Chazard, Emmanuel; Hue, Valérie; Duhamel, Alain; Martinot, Alain

    2013-01-01

    Dehydration secondary to gastroenteritis is one of the most common reasons for office visits and hospital admissions. The indicator most commonly used to estimate dehydration status is acute weight loss. Post-illness weight gain is considered as the gold-standard to determine the true level of dehydration and is widely used to estimate weight loss in research. To determine the value of post-illness weight gain as a gold standard for acute dehydration, we conducted a prospective cohort study in which 293 children, aged 1 month to 2 years, with acute diarrhea were followed for 7 days during a 3-year period. The main outcome measures were an accurate pre-illness weight (if available within 8 days before the diarrhea), post-illness weight, and theoretical weight (predicted from the child’s individual growth chart). Post-illness weight was measured for 231 (79%) and both theoretical and post-illness weights were obtained for 111 (39%). Only 62 (21%) had an accurate pre-illness weight. The correlation between post-illness and theoretical weight was excellent (0.978), but bootstrapped linear regression analysis showed that post-illness weight underestimated theoretical weight by 0.48 kg (95% CI: 0.06–0.79, p<0.02). The mean difference in the fluid deficit calculated was 4.0% of body weight (95% CI: 3.2–4.7, p<0.0001). Theoretical weight overestimated accurate pre-illness weight by 0.21 kg (95% CI: 0.08–0.34, p = 0.002). Post-illness weight underestimated pre-illness weight by 0.19 kg (95% CI: 0.03–0.36, p = 0.02). The prevalence of 5% dehydration according to post-illness weight (21%) was significantly lower than the prevalence estimated by either theoretical weight (60%) or clinical assessment (66%, p<0.0001).These data suggest that post-illness weight is of little value as a gold standard to determine the true level of dehydration. The performance of dehydration signs or scales determined by using post-illness weight as a gold standard has to be

  4. The value of body weight measurement to assess dehydration in children.

    PubMed

    Pruvost, Isabelle; Dubos, François; Chazard, Emmanuel; Hue, Valérie; Duhamel, Alain; Martinot, Alain

    2013-01-01

    Dehydration secondary to gastroenteritis is one of the most common reasons for office visits and hospital admissions. The indicator most commonly used to estimate dehydration status is acute weight loss. Post-illness weight gain is considered as the gold-standard to determine the true level of dehydration and is widely used to estimate weight loss in research. To determine the value of post-illness weight gain as a gold standard for acute dehydration, we conducted a prospective cohort study in which 293 children, aged 1 month to 2 years, with acute diarrhea were followed for 7 days during a 3-year period. The main outcome measures were an accurate pre-illness weight (if available within 8 days before the diarrhea), post-illness weight, and theoretical weight (predicted from the child's individual growth chart). Post-illness weight was measured for 231 (79%) and both theoretical and post-illness weights were obtained for 111 (39%). Only 62 (21%) had an accurate pre-illness weight. The correlation between post-illness and theoretical weight was excellent (0.978), but bootstrapped linear regression analysis showed that post-illness weight underestimated theoretical weight by 0.48 kg (95% CI: 0.06-0.79, p<0.02). The mean difference in the fluid deficit calculated was 4.0% of body weight (95% CI: 3.2-4.7, p<0.0001). Theoretical weight overestimated accurate pre-illness weight by 0.21 kg (95% CI: 0.08-0.34, p = 0.002). Post-illness weight underestimated pre-illness weight by 0.19 kg (95% CI: 0.03-0.36, p = 0.02). The prevalence of 5% dehydration according to post-illness weight (21%) was significantly lower than the prevalence estimated by either theoretical weight (60%) or clinical assessment (66%, p<0.0001).These data suggest that post-illness weight is of little value as a gold standard to determine the true level of dehydration. The performance of dehydration signs or scales determined by using post-illness weight as a gold standard has to be reconsidered.

  5. Comparison of oxygen saturation values and measurement times by pulse oximetry in various parts of the body.

    PubMed

    Yönt, Gülendam Hakverdioğlu; Korhan, Esra Akin; Khorshid, Leyla

    2011-11-01

    The aim of this study, which included 40 patients, was to compare the values pulse oximetry and the measurement times in various regions of the body. Data were analyzed using intraclass correlation coefficient test and paired-sample test. The confidence power value was found to be .81 for the comparison of oxygen saturation values by arterial blood gas analysis and measurement by the forehead probe. It was found that the time for oxygen saturation measurement using the forehead probe was shorter than those using the finger and toe probes. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. The Math-Biology Values Instrument: Development of a Tool to Measure Life Science Majors' Task Values of Using Math in the Context of Biology.

    PubMed

    Andrews, Sarah E; Runyon, Christopher; Aikens, Melissa L

    2017-01-01

    In response to calls to improve the quantitative training of undergraduate biology students, there have been increased efforts to better integrate math into biology curricula. One challenge of such efforts is negative student attitudes toward math, which are thought to be particularly prevalent among biology students. According to theory, students' personal values toward using math in a biological context will influence their achievement and behavioral outcomes, but a validated instrument is needed to determine this empirically. We developed the Math-Biology Values Instrument (MBVI), an 11-item college-level self--report instrument grounded in expectancy-value theory, to measure life science students' interest in using math to understand biology, the perceived usefulness of math to their life science career, and the cost of using math in biology courses. We used a process that integrates multiple forms of validity evidence to show that scores from the MBVI can be used as a valid measure of a student's value of math in the context of biology. The MBVI can be used by instructors and researchers to help identify instructional strategies that influence math-biology values and understand how math-biology values are related to students' achievement and decisions to pursue more advanced quantitative-based courses. © 2017 S. E. Andrews et al. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  7. Measuring changes in lipid and blood glucose values in the health and wellness program of Prudential Financial, Inc.

    PubMed

    Short, Meghan E; Goetzel, Ron Z; Young, Jared S; Kowlessar, Niranjana M; Liss-Levinson, Rivka C; Tabrizi, Maryam J; Roemer, Enid Chung; Sabatelli, Adriano A; Winick, Keith; Montes, Myrtho; Crighton, K Andrew

    2010-08-01

    To determine the effect of health promotion programs of Prudential Financial, Inc on biometric measures of blood lipids and glucose. Using actual biometric and self-reported measures of blood lipids and glucose values for the employees of Prudential Financial, Inc, we examined 1) the extent to which self-reported lipid and blood glucose values correlate to laboratory data, 2) whether self-reported and measured lipid values differ for physically active and sedentary employees, and 3) whether participation in a disease management program affects employees' lipid measures. We found significant differences in self-reported and measured total cholesterol and low-density lipoprotein values, although these differences and those for all lipid and blood glucose values were not clinically meaningful. Supporting previous clinical studies, high-density lipoprotein values were significantly higher for fitness center users compared with sedentary employees. Finally, disease management participants showed a significant reduction in total cholesterol and low-density lipoprotein during a 3-year period compared with nonparticipants. On average, the employees of Prudential Financial, Inc were aware of and accurately reported their lipid and blood glucose levels. Results from this study support the value of evaluating corporate health promotion programs, using measured biometric outcomes.

  8. [Digital blood flow measurement by venous occlusion plethysmography in Raynaud's phenomenon. Value of the rewarming test].

    PubMed

    Cristol, R; Debray, J

    1986-01-01

    The fingertip blood flow measured by mercury strain gauge plethysmography with venous occlusion, at 22 degrees C room temperature, had significantly lower mean values in 190 patients with Raynaud's phenomenon (55 men aged 49 yrs +/- 16, 135 women aged 48 yrs +/- 16) than in 40 age and sex matched controls: 18 ml/100 ml/minute +/- 14.6 versus 35 ml/100 ml/minute +/- 15 at level p less than 0.01. The mean fingertip blood flow was significantly lower (p less than 0.01) in 31 cases of scleroderma and 32 cases of pulpar necrosis (respectively 13 ml +/- 13 and 11 ml +/- 8) than in 55 cases of primary Raynaud's disease (no detectable etiology and normal capillaroscopy 5 years after onset) or in 34 cases of mild Raynaud's phenomenon (respectively 21.6 +/- 16 and 24.4 +/- 18). A warming test (both hands in water at 45 degrees C during 3 minutes) was performed in 50 cases with low basal fingertip blood flow. It induced a "normalized" flow in 22 cases (mostly primary or mild Raynaud), a partly improved flow in 20 cases (mostly secondary Raynaud) and no improvement in 8 cases (scleroderma). The warming test appears to be clinically useful to assess the vasospasm and the vasodilating capabilities.

  9. Establishing Common Cost Measures to Evaluate the Economic Value of Patient Navigation Programs

    PubMed Central

    Whitley, Elizabeth; Valverde, Patricia; Wells, Kristen; Williams, Loretta; Teschner, Taylor; Shih, Ya-Chen Tina

    2011-01-01

    Background Patient navigation is an intervention aimed at reducing barriers to healthcare for underserved populations as a means to reduce cancer health disparities. Despite the proliferation of patient navigation programs across the United States, information related to the economic impact and sustainability of these programs is lacking. Method Following a review of the relevant literature, the Health Services Research (HSR) cost workgroup of the American Cancer Society National Patient Navigator Leadership Summit met to examine cost data relevant to assessing the economic impact of patient navigation and to propose common cost metrics. Results Recognizing that resources available for data collection, management and analysis vary, five categories of core and optional cost measures were identified related to patient navigator programs, including, program costs, human capital costs, direct medical costs, direct non-medical costs and indirect costs. Conclusion(s) Information demonstrating economic as well as clinical value is necessary to make decisions about sustainability of patient navigation programs. Adoption of these common cost metrics are recommended to promote understanding of the economic impact of patient navigation and comparability across diverse patient navigation programs. PMID:21780096

  10. On approximately symmetric informationally complete positive operator-valued measures and related systems of quantum states

    NASA Astrophysics Data System (ADS)

    Klappenecker, Andreas; Rötteler, Martin; Shparlinski, Igor E.; Winterhof, Arne

    2005-08-01

    We address the problem of constructing positive operator-valued measures (POVMs) in finite dimension n consisting of n2 operators of rank one which have an inner product close to uniform. This is motivated by the related question of constructing symmetric informationally complete POVMs (SIC-POVMs) for which the inner products are perfectly uniform. However, SIC-POVMs are notoriously hard to construct and, despite some success of constructing them numerically, there is no analytic construction known. We present two constructions of approximate versions of SIC-POVMs, where a small deviation from uniformity of the inner products is allowed. The first construction is based on selecting vectors from a maximal collection of mutually unbiased bases and works whenever the dimension of the system is a prime power. The second construction is based on perturbing the matrix elements of a subset of mutually unbiased bases. Moreover, we construct vector systems in Cn which are almost orthogonal and which might turn out to be useful for quantum computation. Our constructions are based on results of analytic number theory.

  11. Phase-space representations of symmetric informationally complete positive-operator-valued-measure fiducial states

    NASA Astrophysics Data System (ADS)

    Saraceno, Marcos; Ermann, Leonardo; Cormick, Cecilia

    2017-03-01

    The problem of finding symmetric informationally complete positive-operator-valued-measures (SIC-POVMs) has been solved numerically for all dimensions d up to 67 [A. J. Scott and M. Grassl, J. Math. Phys. 51, 042203 (2010), 10.1063/1.3374022], but a general proof of existence is still lacking. For each dimension, it was shown that it is possible to find a SIC-POVM that is generated from a fiducial state upon application of the operators of the Heisenberg-Weyl group. We draw on the numerically determined fiducial states to study their phase-space features, as displayed by the characteristic function and the Wigner, Bargmann, and Husimi representations, adapted to a Hilbert space of finite dimension. We analyze the phase-space localization of fiducial states, and observe that the SIC-POVM condition is equivalent to a maximal delocalization property. Finally, we explore the consequences in phase space of the conjectured Zauner symmetry. In particular, we construct a Hermitian operator commuting with this symmetry that leads to a representation of fiducial states in terms of eigenfunctions with definite semiclassical features.

  12. 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

  13. Countercurrent flow absorber and desorber

    DOEpatents

    Wilkinson, William H.

    1984-01-01

    Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system.

  14. Countercurrent flow absorber and desorber

    DOEpatents

    Wilkinson, W.H.

    1984-10-16

    Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system. 9 figs.

  15. 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

  16. 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).

  17. 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

  18. Evaluation of oxygen radical absorbance capacity in kampo medicine.

    PubMed

    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.

  19. 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…

  20. Spectrophotometric Measurement of Minimal Erythema Dose Sites after Narrowband Ultraviolet B Phototesting: Clinical Implication of Spetrophotometric Values in Phototherapy

    PubMed Central

    Jeon, Su-Young; Lee, Chae-Young; Song, Ki-Hoon

    2014-01-01

    Background The spectrophotometer is well known to be a useful tool for estimating the objective minimal erythema dose (MED) during planning of phototherapy protocol. However, only a few spectrophotometric values are used to evaluate the erythema and pigmentation of the MED site during phototesting. Objective To determinea new meaning of the relationships among spectrophotometric values during phototesting. Methods Twenty-five patients with psoriasis and 23 patients with vitiligo were selected before undergoing narrowband ultraviolet B phototherapy. We interpreted the gross findings of erythema and measured the L*a*b* values using a spectrophotometer at each phototest spot. We compared MEDs, basic spectrophotometric values (L*a*b*), and b*/L* values separately according to skin type, and determined the correlation of each spectrophotometric value and the correlation between a* and b*/L* values. Results Among L*a*b* values, only b* values showed a statistically significant difference between the type III and IV groups (p=0.003). There was a positive correlation only between MEDs and b* values (p<0.05). The average b*/L*value in the type IV group was significantly higher than the type III group (p<0.05). Conclusion The higher b* values in type IV skin indicates that skin tanning develops more prominently than type III. The correlation between MEDs and b* values may signify that the skin pigmentation status is deepened with the higher MEDs. The difference in b*/L*values between type III and IV skin reflects that the b*/L*value is thought to be an index of tanning. The a* value, known as an index of erythema, does not influence the degree of tanning. PMID:24648682

  1. Absorbing devaluation: Pemex penalized

    SciTech Connect

    NONE

    Shock from Mexico`s international finance debacle has created a ripple across the global pond, affecting trading markets from Buenos Aires to Hong Kong. Mexican consumers must cope with a currency that can purchase 40% fewer imported goods than it could seven weeks ago. The Mexican government has taken austerity measures controlling prices on staple consumer items designed to prevent rampant inflation. State oil company Petroleos Mexicanos is left exposed to some of the costs of the peso devaluation to supply Mexican gasoline markets with imported supply. However, Mexico`s flexible tax structure allows Pemex to divert the cost throughout its operations.

  2. Thermally induced nonlinear optical absorption in metamaterial perfect absorbers

    NASA Astrophysics Data System (ADS)

    Guddala, Sriram; Kumar, Raghwendra; Ramakrishna, S. Anantha

    2015-03-01

    A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks was fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm2.

  3. A Method for Determining Pseudo-measurement State Values for Topology Observability of State Estimation in Power Systems

    NASA Astrophysics Data System (ADS)

    Urano, Shoichi; Mori, Hiroyuki

    This paper proposes a new technique for determining of state values in power systems. Recently, it is useful for carrying out state estimation with data of PMU (Phasor Measurement Unit). The authors have developed a method for determining state values with artificial neural network (ANN) considering topology observability in power systems. ANN has advantage to approximate nonlinear functions with high precision. The method evaluates pseudo-measurement state values of the data which are lost in power systems. The method is successfully applied to the IEEE 14-bus system.

  4. Defining and Delivering Measurable Value: A Mega Thinking and Planning Primer

    ERIC Educational Resources Information Center

    Kaufman, Roger

    2005-01-01

    Mega planning has a primary focus on adding value for all stakeholders. It is realistic, practical, and ethical. Denning and then achieving sustained organizational success is possible. It relies on three basic elements: (1) "A societal value-added "frame of mind" or paradigm": your perspective about your organization, people, and our world. It…

  5. Measurement and Analysis of Soldiers’ Value Systems Change during Infantry Initial Entry Training.

    DTIC Science & Technology

    1982-12-01

    Media". Journal of Advertising Research , 21, (October 1981): 37-43. Blair, John D. "Social and Value Integration of Youth in the Military". Youth and...Society 10 (September 1978): 33-46. Boote, Alfred S. "Market Segmentation by Personal Values and Salient Product Attributes". Journal of Advertising Research 21

  6. Measuring salient food attitudes and food-related values. An elaborated, conflicting and interdependent system.

    PubMed

    Hauser, Mirjam; Jonas, Klaus; Riemann, Rainer

    2011-10-01

    Consumer food choice behaviour in post-industrial countries is complex and influenced by a multitude of interacting variables. This study looked at the antecedents of behaviour and examined salient food-related values and attitudes. To discover personal meanings and patterns of everyday food choices across different situations we used a qualitative approach in the form of repertory grid interviews. An analysis of the personal constructs elicited from a representative sample of 100 Swiss consumers revealed elaborated value systems. The food-related values can be summarised as: authenticity/naturalness, conviviality, health, quality/indulgence, convenience, and price. The salience of these values and their negatively evaluated counterparts differed for various social eating situations and product categories. Consumers' personal values also differed significantly from their perception of current trends in eating culture. In every-day food choices interdependent food-related values compete and are thus a possible cause of ambivalence and conflicts. The findings offer explanations of discrepancies between values/attitudes and behaviour that may be due to situational constraints and habits. Implications for companies include the need for strategic realignment to regain consumers' trust by providing comprehensive value-congruent food solutions that also consider health and ethical criteria. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Value-Added Models and the Measurement of Teacher Productivity. CALDER Working Paper No. 54

    ERIC Educational Resources Information Center

    Harris, Douglas; Sass, Tim; Semykina, Anastasia

    2010-01-01

    Research on teacher productivity, and recently developed accountability systems for teachers, rely on value-added models to estimate the impact of teachers on student performance. The authors test many of the central assumptions required to derive value-added models from an underlying structural cumulative achievement model and reject nearly all…

  8. 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…

  9. Measuring the Value of Statistical Life: Estimating Compensating Wage Differentials among Workers in India

    ERIC Educational Resources Information Center

    Madheswaran, S.

    2007-01-01

    Policy makers confronted with the need to introduce health and safety regulations often wonder how to value the benefits of these regulations. One way that a monetary value could be placed on reductions in health risks, including risk of death, is through understanding how people are compensated for the different risks they take. While there is an…

  10. 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.

  11. MEthods of ASsessing blood pressUre: identifying thReshold and target valuEs (MeasureBP): a review & study protocol.

    PubMed

    Blom, Kimberly C; Farina, Sasha; Gomez, Yessica-Haydee; Campbell, Norm R C; Hemmelgarn, Brenda R; Cloutier, Lyne; McKay, Donald W; Dawes, Martin; Tobe, Sheldon W; Bolli, Peter; Gelfer, Mark; McLean, Donna; Bartlett, Gillian; Joseph, Lawrence; Featherstone, Robin; Schiffrin, Ernesto L; Daskalopoulou, Stella S

    2015-04-01

    Despite progress in automated blood pressure measurement (BPM) technology, there is limited research linking hard outcomes to automated office BPM (OBPM) treatment targets and thresholds. Equivalences for automated BPM devices have been estimated from approximations of standardized manual measurements of 140/90 mmHg. Until outcome-driven targets and thresholds become available for automated measurement methods, deriving evidence-based equivalences between automated methods and standardized manual OBPM is the next best solution. The MeasureBP study group was initiated by the Canadian Hypertension Education Program to close this critical knowledge gap. MeasureBP aims to define evidence-based equivalent values between standardized manual OBPM and automated BPM methods by synthesizing available evidence using a systematic review and individual subject-level data meta-analyses. This manuscript provides a review of the literature and MeasureBP study protocol. These results will lay the evidenced-based foundation to resolve uncertainties within blood pressure guidelines which, in turn, will improve the management of hypertension.

  12. Microwave absorbing property of silicone rubber composites with added carbonyl iron particles and graphite platelet

    NASA Astrophysics Data System (ADS)

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

    2013-02-01

    Silicone rubber composites filled with carbonyl iron particles (CIPs) and graphite platelet (GP) were prepared using non-coating or coating processes. The complex permittivity and permeability of the composites were measured using a vector network analyzer in the frequency range of 1-18 GHz and dc electric conductivity was measured by the standard four-point contact method. The results showed that CIPs/GP composites fabricated in the coating process had the highest permittivity and permeability due to the particle orientation and interactions between the two absorbents. The coating process resulted in a decreased effective eccentricity of the absorbents, and the dc conductivity increased according to Neelakanta's equations. The reflection loss (RL) value showed that the composites had an excellent absorbing property in the L-band, minimum -11.85 dB at 1.5 mm and -15.02 dB at 2 mm. Thus, GP could be an effective additive in preparing thin absorbing composites in the L-band.

  13. Carbon Absorber Retrofit Equipment (CARE)

    SciTech Connect

    Klein, Eric

    During Project DE-FE0007528, CARE (Carbon Absorber Retrofit Equipment), Neumann Systems Group (NSG) designed, installed and tested a 0.5MW NeuStream® carbon dioxide (CO 2) capture system using the patented NeuStream® absorber equipment and concentrated (6 molal) piperazine (PZ) as the solvent at Colorado Springs Utilities’ (CSU’s) Martin Drake pulverized coal (PC) power plant. The 36 month project included design, build and test phases. The 0.5MW NeuStream® CO 2 capture system was successfully tested on flue gas from both coal and natural gas combustion sources and was shown to meet project objectives. Ninety percent CO 2 removal was achieved with greater thanmore » 95% CO 2product purity. The absorbers tested support a 90% reduction in absorber volume compared to packed towers and with an absorber parasitic power of less than 1% when configured for operation with a 550MW coal plant. The preliminary techno-economic analysis (TEA) performed by the Energy and Environmental Research Center (EERC) predicted an over-the-fence cost of $25.73/tonne of CO 2 captured from a sub-critical PC plant.« less

  14. Additive manufacturing of RF absorbers

    NASA Astrophysics Data System (ADS)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  15. Using Publicly Available Data to Construct a Transparent Measure of Health Care Value: A Method and Initial Results.

    PubMed

    Weeks, William B; Kotzbauer, Gregory R; Weinstein, James N

    2016-06-01

    Using publicly available Hospital Compare and Medicare data, we found a substantial range of hospital-level performance on quality, expenditure, and value measures for 4 common reasons for admission. Hospitals' ability to consistently deliver high-quality, low-cost care varied across the different reasons for admission. With the exception of coronary artery bypass grafting, hospitals that provided the highest-value care had more beds and a larger average daily census than those providing the lowest-value care. Transparent data like those we present can empower patients to compare hospital performance, make better-informed treatment decisions, and decide where to obtain care for particular health care problems. In the United States, the transition from volume to value dominates discussions of health care reform. While shared decision making might help patients determine whether to get care, transparency in procedure- and hospital-specific value measures would help them determine where to get care. Using Hospital Compare and Medicare expenditure data, we constructed a hospital-level measure of value from a numerator composed of quality-of-care measures (satisfaction, use of timely and effective care, and avoidance of harms) and a denominator composed of risk-adjusted 30-day episode-of-care expenditures for acute myocardial infarction (1,900 hospitals), coronary artery bypass grafting (884 hospitals), colectomy (1,252 hospitals), and hip replacement surgery (1,243 hospitals). We found substantial variation in aggregate measures of quality, cost, and value at the hospital level. Value calculation provided additional richness when compared to assessment based on quality or cost alone: about 50% of hospitals in an extreme quality- (and about 65% more in an extreme cost-) quintile were in the same extreme value quintile. With the exception of coronary artery bypass grafting, higher-value hospitals were larger and had a higher average daily census than lower-value

  16. 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

  17. 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.

  18. SINIS bolometer with a suspended absorber

    NASA Astrophysics Data System (ADS)

    Tarasov, M.; Edelman, V.; Mahashabde, S.; Fominsky, M.; Lemzyakov, S.; Chekushkin, A.; Yusupov, R.; Winkler, D.; Yurgens, A.

    2018-03-01

    We have developed a Superconductor-Insulator-Normal Metal-Insulator-Superconductor (SINIS) bolometer with a suspended normal metal bridge. The suspended bridge acts as a bolometric absorber with reduced heat losses to the substrate. Such bolometers were characterized at 100-350 mK bath temperatures and electrical responsivity of over 109 V/W was measured by dc heating the absorber through additional contacts. Suspended bolometers were also integrated in planar twin-slot and log-periodic antennas for operation in the submillimetre-band of radiation. The measured voltage response to radiation at 300 GHz and at 100 mK bath temperature is 3*108 V/W and a current response is 1.1*104 A/W which corresponds to a quantum efficiency of ~15 electrons per photon. An important feature of such suspended bolometers is the thermalization of electrons in the absorber heated by optical radiation, which in turn provides better quantum efficiency. This has been confirmed by comparison of bolometric response to dc and rf heating. We investigate the performance of direct SN traps and NIS traps with a tunnel barrier between the superconductor and normal metal trap. Increasing the volume of superconducting electrode helps to reduce overheating of superconductor. Influence of Andreev reflection and Kapitza resistance, as well as electron-phonon heat conductivity and thermal conductivity of N-wiring are estimated for such SINIS devices.

  19. Investigations on Absorber Materials at Cryogenic Temperatures

    SciTech Connect

    Marhauser, Frank; Elliott, Thomas; Rimmer, Robert

    2009-05-01

    In the framework of the 12 GeV upgrade project for the Continuous Electron Beam Accelerator Facility (CEBAF) improvements are being made to refurbish cryomodules housing Thomas Jefferson National Accelerator Facility's (JLab) original 5-cell cavities. Recently we have started to look into a possible simplification of the existing Higher Order Mode (HOM) absorber design combined with the aim to find alternative material candidates. The absorbers are implemented in two HOM-waveguides immersed in the helium bath and operate at 2 K temperature. We have built a cryogenic setup to perform measurements on sample load materials to investigate their lossy characteristics and variationsmore » from room temperature down to 2 K. Initial results are presented in this paper.« less

  20. 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…

  1. Better Absorbents for Ammonia Separation

    SciTech Connect

    Malmali, Mahdi; Le, Giang; Hendrickson, Jennifer

    Making ammonia from renewable wind energy at a competitive price may be possible if the conventional ammonia condenser is replaced with an ammonia absorber. Such a process change requires an ammonia selective absorbent. Supported metal halide sorbents for this separation display outstanding dynamic capacity close to their equilibrium thermodynamic limits. Alkaline earth chlorides and bromides supported on silica and zeolite Y are the most promising. MgCl 2 and CaBr 2 at 40% loading on silica show capacities of 60-70 mg NH3/gsorbent at 150 °C and 4 bar. Overall, cations with smaller atomic numbers show more affinity to ammonia; bromides holdmore » ammonia more strongly than chlorides. Different solvents and metal halide mixtures do not show significant changes in the absorption capacity. Finally, these absorbents can be incorporated into ammonia reaction-absorption syntheses to achieve faster production rates.« less

  2. Better Absorbents for Ammonia Separation

    DOE PAGES

    Malmali, Mahdi; Le, Giang; Hendrickson, Jennifer; ...

    2018-03-30

    Making ammonia from renewable wind energy at a competitive price may be possible if the conventional ammonia condenser is replaced with an ammonia absorber. Such a process change requires an ammonia selective absorbent. Supported metal halide sorbents for this separation display outstanding dynamic capacity close to their equilibrium thermodynamic limits. Alkaline earth chlorides and bromides supported on silica and zeolite Y are the most promising. MgCl 2 and CaBr 2 at 40% loading on silica show capacities of 60-70 mg NH3/gsorbent at 150 °C and 4 bar. Overall, cations with smaller atomic numbers show more affinity to ammonia; bromides holdmore » ammonia more strongly than chlorides. Different solvents and metal halide mixtures do not show significant changes in the absorption capacity. Finally, these absorbents can be incorporated into ammonia reaction-absorption syntheses to achieve faster production rates.« less

  3. Low temperature selective absorber research

    NASA Astrophysics Data System (ADS)

    Herzenberg, S. A.; Silberglitt, R.

    1982-04-01

    Research carried out since 1979 on selective absorbers is surveyed, with particular attention given to the low-temperature coatings seen as promising for flat plate and evacuated tube applications. The most thoroughly investigated absorber is black chrome, which is highly selective and is the most durable low-temperature absorber. It is believed that other materials, because of their low cost and lower content of strategic materials, may eventually supplant black chrome. Among these candidates are chemically converted black nickel; anodically oxidized nickel, zinc, and copper composites; and nickel or other low-cost multilayer coatings. In reviewing medium and high-temperature research, black chrome, multilayer coatings and black cobalt are seen as best medium-temperature candidates. For high temperatures, an Al2O3/Pt-Al203 multilayer composite or the zirconium diboride coating is preferred.

  4. Factors influencing the robustness of P-value measurements in CT texture prognosis studies

    NASA Astrophysics Data System (ADS)

    McQuaid, Sarah; Scuffham, James; Alobaidli, Sheaka; Prakash, Vineet; Ezhil, Veni; Nisbet, Andrew; South, Christopher; Evans, Philip

    2017-07-01

    Several studies have recently reported on the value of CT texture analysis in predicting survival, although the topic remains controversial, with further validation needed in order to consolidate the evidence base. The aim of this study was to investigate the effect of varying the input parameters in the Kaplan-Meier analysis, to determine whether the resulting P-value can be considered to be a robust indicator of the parameter’s prognostic potential. A retrospective analysis of the CT-based normalised entropy of 51 patients with lung cancer was performed and overall survival data for these patients were collected. A normalised entropy cut-off was chosen to split the patient cohort into two groups and log-rank testing was performed to assess the survival difference of the two groups. This was repeated for varying normalised entropy cut-offs and varying follow-up periods. Our findings were also compared with previously published results to assess robustness of this parameter in a multi-centre patient cohort. The P-value was found to be highly sensitive to the choice of cut-off value, with small changes in cut-off producing substantial changes in P. The P-value was also sensitive to follow-up period, with particularly noisy results at short follow-up periods. Using matched conditions to previously published results, a P-value of 0.162 was obtained. Survival analysis results can be highly sensitive to the choice in texture cut-off value in dichotomising patients, which should be taken into account when performing such studies to avoid reporting false positive results. Short follow-up periods also produce unstable results and should therefore be avoided to ensure the results produced are reproducible. Previously published findings that indicated the prognostic value of normalised entropy were not replicated here, but further studies with larger patient numbers would be required to determine the cause of the different outcomes.

  5. Modelling the cost-effectiveness of impact-absorbing flooring in Swedish residential care facilities.

    PubMed

    Ryen, Linda; Svensson, Mikael

    2016-06-01

    Fall-related injuries among the elderly, specifically hip fractures, cause significant morbidity and mortality as well as imposing a substantial financial cost on the health care system. Impact-absorbing flooring has been advocated as an effective method for preventing hip fractures resulting from falls. This study identifies the cost-effectiveness of impact-absorbing flooring compared to standard flooring in residential care facilities for the elderly in a Swedish setting. An incremental cost-effectiveness analysis was performed comparing impact-absorbing flooring to standard flooring using a Markov decision model. A societal perspective was adopted and incremental costs were compared to incremental gains in quality-adjusted life years (QALYs). Data on costs, probability transitions and health-related quality of life measures were retrieved from the published literature and from Swedish register data. Probabilistic sensitivity analysis was performed through a Monte Carlo simulation. The base-case analysis indicates that the impact-absorbing flooring reduces costs and increases QALYs. When allowing for uncertainty we find that 60% of the simulations indicate that impact-absorbing flooring is cost-saving compared to standard flooring and an additional 20% that it has a cost per QALY below a commonly used threshold value : Using a modelling approach, we find that impact-absorbing flooring is a dominant strategy at the societal level considering that it can save resources and improve health in a vulnerable population. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  6. Skin Temperature Measurement Using Contact Thermometry: A Systematic Review of Setup Variables and Their Effects on Measured Values

    PubMed Central

    MacRae, Braid A.; Annaheim, Simon; Spengler, Christina M.; Rossi, René M.

    2018-01-01

    Background: Skin temperature (Tskin) is commonly measured using Tskin sensors affixed directly to the skin surface, although the influence of setup variables on the measured outcome requires clarification. Objectives: The two distinct objectives of this systematic review were (1) to examine measurements from contact Tskin sensors considering equilibrium temperature and temperature disturbance, sensor attachments, pressure, environmental temperature, and sensor type, and (2) to characterise the contact Tskin sensors used, conditions of use, and subsequent reporting in studies investigating sports, exercise, and other physical activity. Data sources and study selection: For the measurement comparison objective, Ovid Medline and Scopus were used (1960 to July 2016) and studies comparing contact Tskin sensor measurements in vivo or using appropriate physical models were included. For the survey of use, Ovid Medline was used (2011 to July 2016) and studies using contact temperature sensors for the measurement of human Tskin in vivo during sport, exercise, and other physical activity were included. Study appraisal and synthesis methods: For measurement comparisons, assessments of risk of bias were made according to an adapted version of the Cochrane Collaboration's risk of bias tool. Comparisons of temperature measurements were expressed, where possible, as mean difference and 95% limits of agreement (LoA). Meta-analyses were not performed due to the lack of a common reference condition. For the survey of use, extracted information was summarised in text and tabular form. Results: For measurement comparisons, 21 studies were included. Results from these studies indicated minor (<0.5°C) to practically meaningful (>0.5°C) measurement bias within the subgroups of attachment type, applied pressure, environmental conditions, and sensor type. The 95% LoA were often within 1.0°C for in vivo studies and 0.5°C for physical models. For the survey of use, 172 studies were

  7. Skin Temperature Measurement Using Contact Thermometry: A Systematic Review of Setup Variables and Their Effects on Measured Values.

    PubMed

    MacRae, Braid A; Annaheim, Simon; Spengler, Christina M; Rossi, René M

    2018-01-01

    Background: Skin temperature ( T skin ) is commonly measured using T skin sensors affixed directly to the skin surface, although the influence of setup variables on the measured outcome requires clarification. Objectives: The two distinct objectives of this systematic review were (1) to examine measurements from contact T skin sensors considering equilibrium temperature and temperature disturbance, sensor attachments, pressure, environmental temperature, and sensor type, and (2) to characterise the contact T skin sensors used, conditions of use, and subsequent reporting in studies investigating sports, exercise, and other physical activity. Data sources and study selection: For the measurement comparison objective, Ovid Medline and Scopus were used (1960 to July 2016) and studies comparing contact T skin sensor measurements in vivo or using appropriate physical models were included. For the survey of use, Ovid Medline was used (2011 to July 2016) and studies using contact temperature sensors for the measurement of human T skin in vivo during sport, exercise, and other physical activity were included. Study appraisal and synthesis methods: For measurement comparisons, assessments of risk of bias were made according to an adapted version of the Cochrane Collaboration's risk of bias tool. Comparisons of temperature measurements were expressed, where possible, as mean difference and 95% limits of agreement (LoA). Meta-analyses were not performed due to the lack of a common reference condition. For the survey of use, extracted information was summarised in text and tabular form. Results: For measurement comparisons, 21 studies were included. Results from these studies indicated minor (<0.5°C) to practically meaningful (>0.5°C) measurement bias within the subgroups of attachment type, applied pressure, environmental conditions, and sensor type. The 95% LoA were often within 1.0°C for in vivo studies and 0.5°C for physical models. For the survey of use, 172 studies

  8. Adaptive inertial shock-absorber

    NASA Astrophysics Data System (ADS)

    Faraj, Rami; Holnicki-Szulc, Jan; Knap, Lech; Seńko, Jarosław

    2016-03-01

    This paper introduces and discusses a new concept of impact absorption by means of impact energy management and storage in dedicated rotating inertial discs. The effectiveness of the concept is demonstrated in a selected case-study involving spinning management, a recently developed novel impact-absorber. A specific control technique performed on this device is demonstrated to be the main source of significant improvement in the overall efficiency of impact damping process. The influence of various parameters on the performance of the shock-absorber is investigated. Design and manufacturing challenges and directions of further research are formulated.

  9. Damage tolerant light absorbing material

    DOEpatents

    Lauf, Robert J.; Hamby, Jr., Clyde; Akerman, M. Alfred; Seals, Roland D.

    1993-01-01

    A light absorbing article comprised of a composite of carbon-bonded carbon fibers, prepared by: blending carbon fibers with a carbonizable organic powder to form a mixture; dispersing the mixture into an aqueous slurry; vacuum molding the aqueous slurry to form a green article; drying and curing the green article to form a cured article; and, carbonizing the cured article at a temperature of at least about 1000.degree. C. to form a carbon-bonded carbon fiber light absorbing composite article having a bulk density less than 1 g/cm.sup.3.

  10. Damage tolerant light absorbing material

    DOEpatents

    Lauf, R.J.; Hamby, C. Jr.; Akerman, M.A.; Seals, R.D.

    1993-09-07

    A light absorbing article comprised of a composite of carbon-bonded carbon fibers, is prepared by: blending carbon fibers with a carbonizable organic powder to form a mixture; dispersing the mixture into an aqueous slurry; vacuum molding the aqueous slurry to form a green article; drying and curing the green article to form a cured article; and, carbonizing the cured article at a temperature of at least about 1000 C to form a carbon-bonded carbon fiber light absorbing composite article having a bulk density less than 1 g/cm[sup 3]. 9 figures.

  11. Outcome measures for clinical rehabilitation trials: impairment, function, quality of life, or value?

    PubMed

    Wade, Derick T

    2003-10-01

    Choosing outcome measures in rehabilitation research depends on the standard research skills of clear thinking, attention to detail, and minimizing the amount of data collected. In rehabilitation, outcome is more difficult to measure because (1) usually several outcomes are relevant, (2) relevant outcomes are affected by multiple factors in addition to treatment, and (3) even good measures rarely reflect the specific interest of any individual patient or member of the rehabilitation team, leading to some dissent. Measurement of general quality of life is not possible because there is little agreement as to the nature of the construct; moreover, measurement of relevant aspects of quality of life would probably give similar results. Cost in terms of resources can be estimated, but there is no validated or even widely accepted method of relating this to benefit in a fair, open, and rational way. Outcome is best measured at the level of behavior (activities), with other measures being used to aid interpretation.

  12. 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.

  13. 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

  14. Study on the millimeter-wave scale absorber based on the Salisbury screen

    NASA Astrophysics Data System (ADS)

    Yuan, Liming; Dai, Fei; Xu, Yonggang; Zhang, Yuan

    2018-03-01

    In order to solve the problem on the millimeter-wave scale absorber, the Salisbury screen absorber is employed and designed based on the RL. By optimizing parameters including the sheet resistance of the surface resistive layer, the permittivity and the thickness of the grounded dielectric layer, the RL of the Salisbury screen absorber could be identical with that of the theoretical scale absorber. An example is given to verify the effectiveness of the method, where the Salisbury screen absorber is designed by the proposed method and compared with the theoretical scale absorber. Meanwhile, plate models and tri-corner reflector (TCR) models are constructed according to the designed result and their scattering properties are simulated by FEKO. Results reveal that the deviation between the designed Salisbury screen absorber and the theoretical scale absorber falls within the tolerance of radar Cross section (RCS) measurement. The work in this paper has important theoretical and practical significance in electromagnetic measurement of large scale ratio.

  15. The ultraviolet absorbance spectrum of coliform bacteria and its relationship to astronomy

    NASA Astrophysics Data System (ADS)

    Hoyle, F.; Wickramasinghe, N. C.; Jansz, E. R.; Jayatissa, P. M.

    1983-09-01

    The ultraviolet absorbance spectrum of a mixed culture of coliform bacteria is obtained and compared to recent measurements of the extinction curve of starlight. The absorbance of the bacterial suspensions over the wavebands 3500-2000 A and 7000-3400 A are presented along with a comparison of the extinction values for the star HD 14250 with the alpha function of the coliform suspension, which is a measure of the total amount of the material in the line of sight of the star. The agreement is excellent and is just as good as the agreement obtained by Karim et al. (1983) for typtophan in isolation, supporting the contention that the tryptophan responsible for the astronomical extinction is present in the interstellar grains in protein form.

  16. Development of sampling calorimeter with segmented lead glass absorber

    NASA Astrophysics Data System (ADS)

    Terada, R.; Takeshita, T.; Itoh, H.; Kanzaki, I.

    2018-02-01

    Sampling calorimeter is indispensable for physics measurement at collider experiment with PFA. Uncertainty of deposit energy at absorber layer degrades energy resolution. This problem will be solved by using lead glass as absorber, which is clear and heavy. High energy particles produce Cherenkov lights whose light yield corresponds to the track length in the lead glass. This information from the absorber will improve the energy resolution of the calorimeter. Performance of this calorimeter prototype tested for electrons at ELPH beam at Tohoku University has been described. We discuss the problems and its capabilities.

  17. Liver Stiffness Measured by Two-Dimensional Shear-Wave Elastography: Prognostic Value after Radiofrequency Ablation for Hepatocellular Carcinoma.

    PubMed

    Lee, Dong Ho; Lee, Jeong Min; Yoon, Jung-Hwan; Kim, Yoon Jun; Lee, Jeong-Hoon; Yu, Su Jong; Han, Joon Koo

    2018-03-01

    To evaluate the prognostic value of liver stiffness (LS) measured using two-dimensional (2D) shear-wave elastography (SWE) in patients with hepatocellular carcinoma (HCC) treated by radiofrequency ablation (RFA). The Institutional Review Board approved this retrospective study and informed consent was obtained from all patients. A total of 134 patients with up to 3 HCCs ≤5 cm who had undergone pre-procedural 2D-SWE prior to RFA treatment between January 2012 and December 2013 were enrolled. LS values were measured using real-time 2D-SWE before RFA on the procedural day. After a mean follow-up of 33.8 ± 9.9 months, we analyzed the overall survival after RFA using the Kaplan-Meier method and Cox proportional hazard regression model. The optimal cutoff LS value to predict overall survival was determined using the minimal p value approach. During the follow-up period, 22 patients died, and the estimated 1- and 3-year overall survival rates were 96.4 and 85.8%, respectively. LS measured by 2D-SWE was found to be a significant predictive factor for overall survival after RFA of HCCs, as was the presence of extrahepatic metastases. As for the optimal cutoff LS value for the prediction of overall survival, it was determined to be 13.3 kPa. In our study, 71 patients had LS values ≥13.3 kPa, and the estimated 3-year overall survival was 76.8% compared to 96.3% in 63 patients with LS values <13.3 kPa. This difference was statistically significant (hazard ratio = 4.30 [1.26-14.7]; p = 0.020). LS values measured by 2D-SWE was a significant predictive factor for overall survival after RFA for HCC.

  18. Quantifying the value of redundant measurements at GCOS Reference Upper-Air Network sites

    DOE PAGES

    Madonna, F.; Rosoldi, M.; Güldner, J.; ...

    2014-11-19

    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 the integrated water vapour (IWV) and water vapour mixing ratio profiles 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 on the IWV measured with radiosondes, global positioning system, microwave and infrared radiometers, and Raman lidar measurements differed by less than 8%.more » Comparisons of time series of IWV content from ground-based remote sensing instruments with in situ soundings showed that microwave radiometers have the highest redundancy with the IWV time series measured by radiosondes and therefore the highest potential to reduce the random uncertainty of the radiosondes time series. Moreover, the random uncertainty of a time series from one instrument can be reduced by ~ 60% by constraining the measurements with those from another instrument. The best reduction of random uncertainty is achieved by conditioning Raman lidar measurements with microwave radiometer measurements. In conclusion, specific instruments are recommended for atmospheric water vapour measurements at GRUAN sites. This approach can be applied to the study of redundant measurements for other climate variables.« less

  19. Counterflow absorber for an absorption refrigeration system

    DOEpatents

    Reimann, Robert C.

    1984-01-01

    An air-cooled, vertical tube absorber for an absorption refrigeration system is disclosed. Strong absorbent solution is supplied to the top of the absorber and refrigerant vapor is supplied to the bottom of the absorber to create a direct counterflow of refrigerant vapor and absorbent solution in the absorber. The refrigeration system is designed so that the volume flow rate of refrigerant vapor in the tubes of the absorber is sufficient to create a substantially direct counterflow along the entire length of each tube in the absorber. This provides several advantages for the absorber such as higher efficiency and improved heat transfer characteristics, and allows improved purging of non-condensibles from the absorber.

  20. Development of monofilar rotor hub vibration absorber

    NASA Technical Reports Server (NTRS)

    Duh, J.; Miao, W.

    1983-01-01

    A design and ground test program was conducted to study the performance of the monofilar absorber for vibration reduction on a four-bladed helicopter. A monofilar is a centrifugal tuned two degree-of-freedom rotor hub absorber that provides force attenuation at two frequencies using the same dynamic mass. Linear and non-linear analyses of the coupled monofilar/airframe system were developed to study tuning and attenuation characteristics. Based on the analysis, a design was fabricated and impact bench tests verified the calculated non-rotating natural frequencies and mode shapes. Performance characteristics were measured using a rotating absorber test facility. These tests showed significant attenuation of fixed-system 4P hub motions due to 3P inplane rotating-system hub forces. In addition, detuning effects of the 3P monofilar modal response were small due to the nonlinearities and tuning pin slippage. However, attenuation of 4P hub motions due to 5P inplane hub forces was poor. The performance of the 5P monofilar modal response was degraded by torsional motion of the dynamic mass relative to the support arm which resulted in binding of the dynamic components. Analytical design studies were performed to evaluate this torsional motion problem. An alternative design is proposed which may alleviate the torsional motion of the dynamic mass.

  1. Oil and fat absorbing polymers

    NASA Technical Reports Server (NTRS)

    Marsh, H. E., Jr. (Inventor)

    1977-01-01

    A method is described for forming a solid network polymer having a minimal amount of crosslinking for use in absorbing fats and oils. The polymer remains solid at a swelling ratio in oil or fat of at least ten and provides an oil absorption greater than 900 weight percent.

  2. Measurement Error and Bias in Value-Added Models. Research Report. ETS RR-17-25

    ERIC Educational Resources Information Center

    Kane, Michael T.

    2017-01-01

    By aggregating residual gain scores (the differences between each student's current score and a predicted score based on prior performance) for a school or a teacher, value-added models (VAMs) can be used to generate estimates of school or teacher effects. It is known that random errors in the prior scores will introduce bias into predictions of…

  3. Travelers’ Value of Time and Reliability as Measured on Katy Freeway : Final Report.

    DOT National Transportation Integrated Search

    2016-09-01

    The value of travel time savings (VOT) is an estimate of what travelers would be willing to pay in order to save time on a particular trip. If travelers would pay $1 to reduce their travel time by six minutes, then they have a VOT of $10 per hour. VO...

  4. Using Mandated Speed Limits to Measure the Value of a Statistical Life

    ERIC Educational Resources Information Center

    Ashenfelter, Orley; Greenstone, Michael

    2004-01-01

    In 1987 the federal government permitted states to raise the speed limit on their rural interstate roads, but not on their urban interstate roads, from 55 mph to 65 mph. Since the states that adopted the higher speed limit must have valued the travel hours they saved more than the fatalities incurred, this institutional change provides an…

  5. 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…

  6. Contemporary Measures of Career Interest and Values: A Review and Synthesis of Prominent Instruments.

    ERIC Educational Resources Information Center

    Kapes, Jerome T.; And Others

    A study examined the collection of 27 interest and values instruments in the review chapters of the third edition of "A Counselor's Guide to Career Assessment Instruments" (Kapes, Mastie, and Whitfield 1994) to determine their commonalities and differences. The instruments were described and compared on these sets of characteristics: name of…

  7. Individual, Country and Societal Cluster Differences on Measures of Personality, Attitudes, Values, and Social Norms

    ERIC Educational Resources Information Center

    Stankov, Lazar

    2011-01-01

    This study investigated cross-cultural differences on 38 subscales from 4 major domains--personality, social attitudes, values, and social norms. These scales were administered to participants who took the Test of English as a Foreign Language[TM] (TOEFL[R], N = 1,600) and U.S. college students (N = 429). Total variability of each subscale was…

  8. Reference Values for Human Posture Measurements Based on Computerized Photogrammetry: A Systematic Review.

    PubMed

    Macedo Ribeiro, Ana Freire; Bergmann, Anke; Lemos, Thiago; Pacheco, Antônio Guilherme; Mello Russo, Maitê; Santos de Oliveira, Laura Alice; de Carvalho Rodrigues, Erika

    The main objective of this study was to review the literature to identify reference values for angles and distances of body segments related to upright posture in healthy adult women with the Postural Assessment Software (PAS/SAPO). Electronic databases (BVS, PubMed, SciELO and Scopus) were assessed using the following descriptors: evaluation, posture, photogrammetry, physical therapy, postural alignment, postural assessment, and physiotherapy. Studies that performed postural evaluation in healthy adult women with PAS/SAPO and were published in English, Portuguese and Spanish, between the years 2005 and 2014 were included. Four studies met the inclusion criteria. Data from the included studies were grouped to establish the statistical descriptors (mean, variance, and standard deviation) of the body angles and distances. A total of 29 variables were assessed (10 in the anterior views, 16 in the lateral right and left views, and 3 in the posterior views), and its respective mean and standard deviation were calculated. Reference values for the anterior and posterior views showed no symmetry between the right and left sides of the body in the frontal plane. There were also small differences in the calculated reference values for the lateral view. The proposed reference values for quantitative evaluation of the upright posture in healthy adult women estimated in the present study using PAS/SAPO could guide future studies and help clinical practice. Copyright © 2017. Published by Elsevier Inc.

  9. Sensitivity of Value Added School Effect Estimates to Different Model Specifications and Outcome Measures

    ERIC Educational Resources Information Center

    Pride, Bryce L.

    2012-01-01

    The Adequate Yearly Progress (AYP) Model has been used to make many high-stakes decisions concerning schools, though it does not provide a complete assessment of student academic achievement and school effectiveness. To provide a clearer perspective, many states have implemented various Growth and Value Added Models, in addition to AYP. The…

  10. Measuring Teacher Effectiveness with the Pennsylvania Value-Added Assessment System

    ERIC Educational Resources Information Center

    Bowen, Naomi

    2017-01-01

    The purpose of this research was to determine if the Pennsylvania Value-Added Assessment System Average Growth Index (PVAAS AGI) scores, derived from standardized tests and calculated for Pennsylvania schools, provide a valid and reliable assessment of teacher effectiveness, as these scores are currently used to derive 15% of the annual…

  11. 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,…

  12. 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…

  13. 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.…

  14. Two-dimensional QR-coded metamaterial absorber

    NASA Astrophysics Data System (ADS)

    Sui, Sai; Ma, Hua; Wang, Jiafu; Pang, Yongqiang; Zhang, Jieqiu; Qu, Shaobo

    2016-01-01

    In this paper, the design of metamaterial absorbers is proposed based on QR coding and topology optimization. Such absorbers look like QR codes and can be recognized by decoding softwares as well as mobile phones. To verify the design, two lightweight wideband absorbers are designed, which can achieve wideband absorption above 90 % in 6.68-19.30 and 7.00-19.70 GHz, respectively. More importantly, polarization-independent absorption over 90 % can be maintained under incident angle within 55°. The QR code absorber not only can achieve wideband absorption, but also can carry information such as texts and Web sites. They are of important values in applications such identification and electromagnetic protection.

  15. Absorbing boundary conditions for second-order hyperbolic equations

    NASA Technical Reports Server (NTRS)

    Jiang, Hong; Wong, Yau Shu

    1989-01-01

    A uniform approach to construct absorbing artificial boundary conditions for second-order linear hyperbolic equations is proposed. The nonlocal boundary condition is given by a pseudodifferential operator that annihilates travelling waves. It is obtained through the dispersion relation of the differential equation by requiring that the initial-boundary value problem admits the wave solutions travelling in one direction only. Local approximation of this global boundary condition yields an nth-order differential operator. It is shown that the best approximations must be in the canonical forms which can be factorized into first-order operators. These boundary conditions are perfectly absorbing for wave packets propagating at certain group velocities. A hierarchy of absorbing boundary conditions is derived for transonic small perturbation equations of unsteady flows. These examples illustrate that the absorbing boundary conditions are easy to derive, and the effectiveness is demonstrated by the numerical experiments.

  16. Patient value: its nature, measurement, and role in real world evidence studies and outcomes-based reimbursement.

    PubMed

    McKenna, Stephen P; Wilburn, Jeanette

    2018-05-01

    The assessment of "patient value" is fundamental to clinical trials, real world evidence studies, and outcomes-based reimbursement schemes. Measures of health-related quality-of-life (HRQoL) are widely used in health research. Such measures are effective in determining the presence or absence of symptoms and functional ability. However, HRQoL measures were not intended, nor designed, to determine the value to patients of alternative health states. Functions have no intrinsic value-they are a means to fulfil human needs. However, needs can be met in a variety of ways, for example by adopting different functions or by the provision of social services. It is possible to analyze all functions in terms of the needs they satisfy. A needs model has been applied in health research since the 1990s. It is concerned with the extent to which human needs are fulfilled in the presence of disease and its treatment. It is argued that this is the major concern of the patient. Needs-based measures are patient-centric and produce a valid unidimensional index of outcome. Consequently, they provide a direct means of measuring patient value. This approach provides the possibility of evaluating health services in terms of the value they provide to consumers and payers. It also has a role to play in real-world evidence studies and outcomes-based reimbursement. It is recommended that greater attention is given in future to the development of patient-reported outcome measures that provide direct assessments of patient value.

  17. Projective Measures of Intrafamilial Attitudes as a Function of Value Judgments about Higher Education.

    ERIC Educational Resources Information Center

    Sweney, Arthur B.

    The academic community is very concerned at this time to develop measures of professor adequacy against which to validate students' evaluations. Sweney and Weston (1970) found ten independent dimensions which explain attitudes and expectancies of their professors. These became the basis for the Learning Encounter Measure (LEM). Many of these…

  18. 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…

  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 inmore » 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.« less

  20. The absorbed dose to blood from blood-borne activity

    NASA Astrophysics Data System (ADS)

    Hänscheid, H.; Fernández, M.; Lassmann, M.

    2015-01-01

    The radiation absorbed dose to blood and organs from activity in the blood is relevant for nuclear medicine dosimetry and for research in biodosimetry. The present study provides coefficients for the average absorbed dose rates to the blood from blood-borne activity for radionuclides frequently used in targeted radiotherapy and in PET diagnostics. The results were deduced from published data for vessel radius-dependent dose rate coefficients and reasonable assumptions on the blood-volume distribution as a function of the vessel radius. Different parts of the circulatory system were analyzed separately. Vessel size information for heart chambers, aorta, vena cava, pulmonary artery, and capillaries was taken from published results of morphometric measurements. The remaining blood not contained in the mentioned vessels was assumed to reside in fractal-like vascular trees, the smallest branches of which are the arterioles or venules. The applied vessel size distribution is consistent with recommendations of the ICRP on the blood-volume distribution in the human. The resulting average absorbed dose rates to the blood per nuclear disintegration per milliliter (ml) of blood are (in 10-11 Gy·s-1·Bq-1·ml) Y-90: 5.58, I-131: 2.49, Lu-177: 1.72, Sm-153: 2.97, Tc-99m: 0.366, C-11: 4.56, F-18: 3.61, Ga-68: 5.94, I-124: 2.55. Photon radiation contributes 1.1-1.2·10-11 Gy·s-1·Bq-1·ml to the total dose rate for positron emitters but significantly less for the other nuclides. Blood self-absorption of the energy emitted by ß-particles in the whole blood ranges from 37% for Y-90 to 80% for Tc-99m. The correspondent values in vascular trees, which are important for the absorbed dose to organs, range from 30% for Y-90 to 82% for Tc-99m.

  1. 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.

  2. Measuring the subjective value of risky and ambiguous options using experimental economics and functional MRI methods.

    PubMed

    Levy, Ifat; Rosenberg Belmaker, Lior; Manson, Kirk; Tymula, Agnieszka; Glimcher, Paul W

    2012-09-19

    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 ambiguity(1,2), 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 method(3 )to assess the neural representation of the subjective values of risky and ambiguous options(4). 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

  3. Measurement error and timing of predictor values for multivariable risk prediction models are poorly reported.

    PubMed

    Whittle, Rebecca; Peat, George; Belcher, John; Collins, Gary S; Riley, Richard D

    2018-05-18

    Measurement error in predictor variables may threaten the validity of clinical prediction models. We sought to evaluate the possible extent of the problem. A secondary objective was to examine whether predictors are measured at the intended moment of model use. A systematic search of Medline was used to identify a sample of articles reporting the development of a clinical prediction model published in 2015. After screening according to a predefined inclusion criteria, information on predictors, strategies to control for measurement error and intended moment of model use were extracted. Susceptibility to measurement error for each predictor was classified into low and high risk. Thirty-three studies were reviewed, including 151 different predictors in the final prediction models. Fifty-one (33.7%) predictors were categorised as high risk of error, however this was not accounted for in the model development. Only 8 (24.2%) studies explicitly stated the intended moment of model use and when the predictors were measured. Reporting of measurement error and intended moment of model use is poor in prediction model studies. There is a need to identify circumstances where ignoring measurement error in prediction models is consequential and whether accounting for the error will improve the predictions. Copyright © 2018. Published by Elsevier Inc.

  4. 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.

  5. 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.

  6. The value of hemodynamic measurements by air plethysmography in diagnosing venous obstruction of the lower limb.

    PubMed

    Kurstjens, Ralph L M; de Wolf, Mark A F; Alsadah, Sarah A; Arnoldussen, Carsten W K P; Strijkers, Rob H W; Toonder, Irwin M; Wittens, Cees H A

    2016-07-01

    Air plethysmography (APG) is a functional, noninvasive test that can assess volumetric changes in the lower limb and might therefore be used as a diagnostic tool in chronic deep venous disease. However, use of APG in chronic deep venous obstructive disease remains debatable. This study assessed the clinical value of APG in identifying chronic deep venous obstruction. All patients referred to our tertiary, outpatient clinic between January 2011 and August 2013 with chronic venous complaints and suspected outflow obstruction underwent an outflow fraction (OF), ejection fraction (EF), and residual volume fraction (RVF) test using APG. Duplex ultrasound and magnetic resonance venography were used to establish whether and where obstruction was present. Diagnostic values of these tests were assessed for obstructions at different levels of the deep venous system. A total of 312 limbs in 248 patients were tested. Mean age was 45.5 ± 14.0 years, and 62.5% were female. In post-thrombotic disease, specificity and positive predictive value for OF were as high as 98.4% and 95.0%, respectively; however, sensitivity was 34.8% and negative predictive value was 29.6%, with no clinically relevant positive or negative likelihood ratios. No clinically relevant differences were observed in stratifying for level of obstruction. EF and RVF were as inconclusive. Neither could these parameters be used in diagnosing nonthrombotic iliac vein compression. We found a poor correlation between OF, EF, or RVF, determined by APG, and the presence of chronic deep venous obstruction. Therefore, use of its relative parameters is unwarranted in daily clinical practice. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

  7. LISN: Measurement of TEC values, and TID characteristics over South and Central America (Invited)

    NASA Astrophysics Data System (ADS)

    Valladares, C. E.

    2013-12-01

    The Low-latitude Ionospheric Sensor Network (LISN) is a distributed observatory designed to provide the climatology and weather of the low latitude ionosphere over the South American continent. Presently, the LISN observatory consists of 47 GPS receivers able to transmit TEC and scintillation values to a central server in a real-time basis. Historical TEC values from these receivers and from about 300 other GPSs that operated in South and Central America between 2008 and 2012 were used to derive regional maps of TEC and TIDs. A prominent feature of the TEC maps is the intense day-to-day variability that is observed during all seasons and under quiet and active magnetic conditions. To assess the TEC dependencies a non-linear least-square fit was conducted to simultaneously extract the solar flux, magnetic and seasonal variability for each square cell of the TEC maps and for each 30-min local time sector. It was found that TEC values and the anomaly intensity increase as a function of the solar flux. The latitudinal separation increases with magnetic activity, and TEC values in Central America become the largest when Kp is equal to 5o or more. TIDs are seen quite frequently over the Caribbean region and in the northern part of South America. To calculate the TIDs travel velocities, their propagation direction, and the scale-size of the disturbances a multi-site multi-dimension cross-correlation method was applied to the TEC database. Phase velocities of order 150 m/s and scale sizes between 100 and 400 km were typically observed. This paper will present the morphology and statistics of TIDs as a function of latitude, longitude, local time and season. It is also introduced the results of an investigation to correlate the appearance, phase velocity and angle of propagation of TIDs and tropospheric phenomena observed with the TRMM satellite.

  8. Measuring value for money: a scoping review on economic evaluation of health information systems.

    PubMed

    Bassi, Jesdeep; Lau, Francis

    2013-01-01

    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. 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. 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. 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.

  9. Montana Department of Transportation Research Peer Exchange : Implementation, Performance Measures, and the Value of Research

    DOT National Transportation Integrated Search

    2018-01-01

    The Montana Department of Transportation (MDT) Research Program hosted a peer exchange in Helena, Montana, from September 12-14, 2017. The objective for the peer exchange was to explore best practices on implementation, performance measures, and the ...

  10. [Study of new blended chemical absorbents to absorb CO2].

    PubMed

    Wang, Jin-Lian; Fang, Meng-Xiang; Yan, Shui-Ping; Luo, Zhong-Yang; Cen, Ke-Fa

    2007-11-01

    Three kinds of blended absorbents were investigated on bench-scale experimental bench according to absorption rate and regeneration grade to select a reasonable additive concentration. The results show that, among methyldiethanolamine (MDEA) and piperazine (PZ) mixtures, comparing MDEA : PZ = 1 : 0.4 (m : m) with MDEA : PZ = 1 : 0.2 (m : m), the absorption rate is increased by about 70% at 0.2 mol x mol(-1). When regeneration lasting for 40 min, regeneration grade of blended absorbents with PZ concentration of 0.2, 0.4, and 0.8 is decreased to 83.06%, 77.77% and 76.67% respectively while 91.04% for PZ concentration of 0. MDEA : PZ = 1 : 0.4(m : m) is a suitable ratio for MDEA/PZ mixtures as absorption and regeneration properties of the blended absorbents are all improved. The aqueous blends with 10% primary amines and 2% tertiary amines could keep high CO2 absorption rate, and lower regeneration energy consumption. Adding 2% 2-Amino-2-methyl-1-propanol (AMP) to 10% diethanolamine (DEA), the blended amine solvents have an advantage in absorption and regeneration properties over other DEA/AMP mixtures. Blended solvents, which consist of a mixture of primary amines with a small amount of tertiary amines, have the highest absorption rate among the three. And mixed absorbents of secondary amines and a small amount of sterically hindered amines have the best regeneration property. To combine absorption and regeneration properties, blends with medium activator addition to tertiary amines are competitive.

  11. The Value of Measurement for Development of Nursing Knowledge:Underlying Philosophy, Contributions and Critiques.

    PubMed

    Durepos, Pamela; Orr, Elizabeth; Ploeg, Jenny; Kaasalainen, Sharon

    2018-06-26

    A philosophical discussion of constructive realism and measurement in the development of nursing knowledge is presented. Through Carper's four patterns of knowing, nurses come to know a person holistically. However, measurement as a source for nursing knowledge has been criticized for underlying positivism and reductionist approach to exploring reality. Which seems mal-alignment with person-centered care. Discussion paper. Constructive realism bridges positivism and constructivism, facilitating the measurement of physical and psychological phenomena. Reduction of complex phenomena and theoretical constructs into measurable properties is essential to building nursing's empiric knowledge and facilitates (rather than inhibits) person-knowing. Nurses should consider constructive realism as a philosophy to underpin their practice. This philosophy supports measurement as a primary method of inquiry in nursing research and clinical practice. Nurses can carefully select, and purposefully integrate, measurement tools with other methods of inquiry (such as qualitative research methods) to demonstrate the usefulness of nursing interventions and highlight nursing as a science. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. SeHCAT retention values as measured with a collimated and an uncollimated gamma camera: a method comparison study.

    PubMed

    Wright, James W; Lovell, Lesley A; Gemmell, Howard G; McKiddie, Fergus; Staff, Roger T

    2013-07-01

    TauroH-23-(Se) selena-25-homocholic acid retention values are used in the diagnosis of bile acid malabsorption. The standard method for measuring values is with an uncollimated gamma camera, which can create some logistic difficulties, with other background sources of activity, which are irrelevant when a collimator is used, becoming significant. In this study we compare the retention values obtained with a collimated and an uncollimated gamma camera in phantoms and in 23 patients. Bland-Altman plots were created using the data, which showed a mean bias in retention of 0.10% in the phantom study and 0.55% in the patient study between methods. A Wilcoxon signed-rank test with the null hypothesis of zero median difference between uncollimated and collimated methods was not statistically significant to P values less than 0.05 in the patient and phantom studies. In the patient study, on using a fixed boundary of retention (10%) between positive and negative status, the status of one patient was changed from negative (12%) to positive (9%). We conclude that measurement of retention with a collimated gamma camera is similar but not identical to that of uncollimated values. The clinical significance of this shift is unclear, as the threshold of significance and the method of integrating this measure with other clinical factors into management remain unclear.

  13. Measurement of susceptibility artifacts with histogram-based reference value on magnetic resonance images according to standard ASTM F2119.

    PubMed

    Heinrich, Andreas; Teichgräber, Ulf K; Güttler, Felix V

    2015-12-01

    The standard ASTM F2119 describes a test method for measuring the size of a susceptibility artifact based on the example of a passive implant. A pixel in an image is considered to be a part of an image artifact if the intensity is changed by at least 30% in the presence of a test object, compared to a reference image in which the test object is absent (reference value). The aim of this paper is to simplify and accelerate the test method using a histogram-based reference value. Four test objects were scanned parallel and perpendicular to the main magnetic field, and the largest susceptibility artifacts were measured using two methods of reference value determination (reference image-based and histogram-based reference value). The results between both methods were compared using the Mann-Whitney U-test. The difference between both reference values was 42.35 ± 23.66. The difference of artifact size was 0.64 ± 0.69 mm. The artifact sizes of both methods did not show significant differences; the p-value of the Mann-Whitney U-test was between 0.710 and 0.521. A standard-conform method for a rapid, objective, and reproducible evaluation of susceptibility artifacts could be implemented. The result of the histogram-based method does not significantly differ from the ASTM-conform method.

  14. UV-visible absorbance spectroscopy as a proxy for peatland dissolved organic carbon (DOC) quantity and quality: considerations on wavelength and absorbance degradation.

    PubMed

    Peacock, Mike; Evans, Chris D; Fenner, Nathalie; Freeman, Chris; Gough, Rachel; Jones, Timothy G; Lebron, Inma

    2014-05-01

    Absorbance in the UV or visible spectrum (UV-vis) is commonly used as a proxy for DOC concentrations in waters draining upland catchments. To determine the appropriateness of different UV-vis measurements we used surface and pore water samples from two Welsh peatlands in four different experiments: (i) an assessment of single wavelength proxies (1 nm increments between 230-800 nm) for DOC concentration demonstrated that 254 nm was more accurate than 400 nm. The highest R(2) values between absorbance and DOC concentration were generated using 263 nm for one sample set (R(2) = 0.91), and 230 nm for the other three sample sets (respective R(2) values of 0.86, 0.81, and 0.93). (ii) A comparison of different DOC concentration proxies, including single wavelength proxies, a two wavelength model, a proxy using phenolic concentration, and a proxy using the area under a UV spectrum at 250-350 nm. It was found that both a single wavelength proxy (≤263 nm) and a two wavelength model performed well for both pore water and surface water. (iii) An evaluation of the E2 : E3, E2 : E4, E4 : E6 ratios, and SUVA (absorbance at 254 nm normalised to DOC concentration) as indicators of DOC quality showed that the E4 : E6 ratio was subject to extensive variation over time, and was highly correlated between surface water and pore water, suggesting that it is a useful metric to determine temporal changes in DOC quality. (iv) A repeated weekly analysis over twelve weeks showed no consistent change in UV-vis absorbance, and therefore an inferred lack of degradation of total DOC in samples that were filtered and stored in the dark at 4 °C.

  15. 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. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  16. 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

  17. Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment

    DOE PAGES

    Öztürk, Hande; Noyan, I. Cevdet

    2017-08-24

    A rigorous study of sampling and intensity statistics applicable for a powder diffraction experiment as a function of crystallite size is presented. Our analysis yields approximate equations for the expected value, variance and standard deviations for both the number of diffracting grains and the corresponding diffracted intensity for a given Bragg peak. The classical formalism published in 1948 by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] appears as a special case, limited to large crystallite sizes, here. It is observed that both the Lorentz probability expression and the statistics equations used in the classical formalism are inapplicable for nanocrystallinemore » powder samples.« less

  18. Expected values and variances of Bragg peak intensities measured in a nanocrystalline powder diffraction experiment

    SciTech Connect

    Öztürk, Hande; Noyan, I. Cevdet

    A rigorous study of sampling and intensity statistics applicable for a powder diffraction experiment as a function of crystallite size is presented. Our analysis yields approximate equations for the expected value, variance and standard deviations for both the number of diffracting grains and the corresponding diffracted intensity for a given Bragg peak. The classical formalism published in 1948 by Alexander, Klug & Kummer [J. Appl. Phys.(1948),19, 742–753] appears as a special case, limited to large crystallite sizes, here. It is observed that both the Lorentz probability expression and the statistics equations used in the classical formalism are inapplicable for nanocrystallinemore » powder samples.« less

  19. Carotid intima-media thickness: ultrasound measurement, prognostic value and role in clinical practice.

    PubMed

    Nair, Satheesh Balakrishnan; Malik, Rayaz; Khattar, Rajdeep S

    2012-12-01

    Ultrasound measurement of carotid intima-media thickness (IMT) has become a valuable tool for detecting and monitoring progression of atherosclerosis and recently published recommendations provide guidance for proper standardisation of these measurements. Important determinants of carotid IMT include age, gender, systolic blood pressure, diabetes mellitus and serum cholesterol levels. Many studies have shown carotid IMT to correlate with the severity of coronary atherosclerosis assessed by CT coronary calcification scores, coronary angiography and intravascular ultrasound. Consistent with its correlation with cardiovascular risk factors and coronary artery disease, a meta-analysis of large observational studies has shown carotid IMT to be a strong predictor of future cardiovascular events. Moreover, in patients with established coronary artery disease a reduction in carotid IMT has been shown to translate into a reduction in future cardiovascular events. Consensus statements now also recommend carotid IMT measurements to further refine the prognostic assessment of patients traditionally considered to be at an intermediate risk of cardiovascular disease.

  20. Theoretical value of Newtonian constant G confirmed by the International Bureau of Weights & Measures in Paris, France

    NASA Astrophysics Data System (ADS)

    Omerbashich, Mensur

    2015-01-01

    World oldest authority for scientific constants and the keeper of the original metre standard, the International Bureau of Weights and Measures (BIPM) in Paris, France has accomplished a historic confirmation of the Omerbashich's (first-ever) scientific prediction of value of the Newtonian gravitational constant G.