WorldWideScience

Sample records for in-air measurements compare

  1. Disruptive Innovation in Air Measurement Technology: Reality ...

    Science.gov (United States)

    This presentation is a big picture overview on the changing state of air measurement technology in the world, with a focus on the introduction of low-cost sensors into the market place. The presentation discusses how these new technologies may be a case study in disruptive innovation for the air pollution measurement field. The intended audience is primarily those with experience in air pollution measurement methods, but much of the talk is accessible to the general public. This is a keynote presentation on emerging air monitoring technology, to be provided at the AWMA measurements conference in March, 2016.

  2. Absorption of sound in air - High-frequency measurements

    Science.gov (United States)

    Bass, H. E.; Shields, F. D.

    1977-01-01

    The absorption of sound in air at frequencies from 4 to 100 kHz in 1/12 octave intervals, for temperatures from 255.4 K (0 F) to 310.9 K (100 F) in 5.5 K (10 F) intervals, and at 10% relative-humidity increments between 0% and saturation has been measured. The values of free-field absorption have been analyzed to determine the relaxation frequency of oxygen for each of the 92 combinations of temperature and relative humidity studied and the results are compared to an empirical expression. The relaxation frequencies of oxygen have been analyzed to determine the microscopic energy-transfer rates.

  3. Gap in air pollution reduction measures

    International Nuclear Information System (INIS)

    Kamphuis, E.; Spijker, E.

    2006-01-01

    The air quality dossier in the Netherlands requires drastic cleaning of the vehicles fleet. However, the present measures are too much focused on the installation and use of soot filters. Other options to improve the air quality are discussed [nl

  4. Measurement of radon daughters in air samples by alpha spectroscopy

    International Nuclear Information System (INIS)

    Acena, M.L.; Crespo, M.T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of polonium 214 and polonium 218. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter (Author)

  5. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement

    International Nuclear Information System (INIS)

    Acena, M. L.; Crespo, M. T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs

  6. Traceable measurements of the activity concentration in air

    CERN Document Server

    Paul, A; Forkel-Wirth, Doris; Müller, A; Marcos, A

    2002-01-01

    The nuclear reactions induced by high energetic protons in heavy targets such as UC/sub 2/ and ThC cause a particular, complex radiation protection task at facilities like ISOLDE: the measurement of a mixture of different isotopes of the radioactive noble gas radon and the radon progenies in air. The knowledge of their respective activity concentration is fundamental for exposure assessments. Due to the complex mixture of activity concentrations in air, its precise determination is quite difficult. Therefore, a new procedure for taking reference samples was developed and implemented for the traceable measurement of the activity concentration of radioactive ions (e.g., radon progenies) in air. This technique is combined by measuring alpha -particles with a multi-wire ionization chamber for the parallel on-line determination of the activity concentration of different radon isotopes. (10 refs).

  7. Confounding and exposure measurement error in air pollution epidemiology

    NARCIS (Netherlands)

    Sheppard, L.; Burnett, R.T.; Szpiro, A.A.; Kim, J.Y.; Jerrett, M.; Pope, C.; Brunekreef, B.|info:eu-repo/dai/nl/067548180

    2012-01-01

    Studies in air pollution epidemiology may suffer from some specific forms of confounding and exposure measurement error. This contribution discusses these, mostly in the framework of cohort studies. Evaluation of potential confounding is critical in studies of the health effects of air pollution.

  8. Low-frequency sound absorption measurements in air

    Science.gov (United States)

    Zuckerwar, A. J.; Meredith, R. W.

    1984-01-01

    Thirty sets of sound absorption measurements in air at a pressure of 1 atmosphere are presented at temperatures from 10 C to 50 C, relative humidities from 0 to 100 percent, and frequencies from 10 to 2500 Hz. The measurements were conducted by the method of free decay in a resonant tube having a length of 18.261 m and bore diameter of 0.152 m. Background measurements in a gas consisting of 89.5 percent N2 and 10.5 percent Ar, a mixture which has the same sound velocity as air, permitted the wall and structural losses of the tube to be separated from the constituent absorption, consisting of classical rotational and vibrational absorption, in the air samples. The data were used to evaluate the vibrational relaxation frequencies of N2 and/or O2 for each of the 30 sets of meteorological parameters. Over the full range of humidity, the measured relaxation frequencies of N2 in air lie between those specified by ANSI Standard S1.26-1978 and those measured earlier in binary N2H2O mixtures. The measured relaxation frequencies could be determined only at very low values of humidity, reveal a significant trend away from the ANSI standard, in agreement with a prior investigation.

  9. Confounding and exposure measurement error in air pollution epidemiology.

    Science.gov (United States)

    Sheppard, Lianne; Burnett, Richard T; Szpiro, Adam A; Kim, Sun-Young; Jerrett, Michael; Pope, C Arden; Brunekreef, Bert

    2012-06-01

    Studies in air pollution epidemiology may suffer from some specific forms of confounding and exposure measurement error. This contribution discusses these, mostly in the framework of cohort studies. Evaluation of potential confounding is critical in studies of the health effects of air pollution. The association between long-term exposure to ambient air pollution and mortality has been investigated using cohort studies in which subjects are followed over time with respect to their vital status. In such studies, control for individual-level confounders such as smoking is important, as is control for area-level confounders such as neighborhood socio-economic status. In addition, there may be spatial dependencies in the survival data that need to be addressed. These issues are illustrated using the American Cancer Society Cancer Prevention II cohort. Exposure measurement error is a challenge in epidemiology because inference about health effects can be incorrect when the measured or predicted exposure used in the analysis is different from the underlying true exposure. Air pollution epidemiology rarely if ever uses personal measurements of exposure for reasons of cost and feasibility. Exposure measurement error in air pollution epidemiology comes in various dominant forms, which are different for time-series and cohort studies. The challenges are reviewed and a number of suggested solutions are discussed for both study domains.

  10. Measurements of radon activity concentrations in air at Niska spa

    International Nuclear Information System (INIS)

    Adrovic, F.; Vuckovic, B.; Ninkovic, M.

    2004-01-01

    Radon activity concentrations in air were measured in the recreational-tourist center of Niska Banja. Alpha Guard PQ 2000/ MC50 instrumentation (Genitron instruments, Frankfurt) was used. The observed indoor radon concentrations in the air of the Radon Hotel pool lay within the range of 0.980-1.908 kBq/m 3 and were directly dependent on the exhalation of radon from thermomineral waters. Radon concentrations were also measured outdoors, at locations for capping thermomineral water, as well as at locations for draining used water from the Radon Hotel pool. Outdoor radon concentrations as high as over 500 Bq/m 3 were observed. Gamma dose rates were measured in parallel and found to lie within the range of 72-420 nSv/h. The gamma doses correlated well with the observed radon levels. The largest gamma dose rates in air were measured in the pool of Radon Hotel and at the site where this thermomineral water is being capped

  11. Measurement of radon concentration in air employing Lucas chamber

    International Nuclear Information System (INIS)

    Machaj, B.

    1997-01-01

    The results of investigations aimed to determine the main features of radon concentration gauge in air, employing 0.17 L Lucas chamber, and air sample forced by an air pump are presented. For two hour sampling and measuring cycle time the dynamic error in the worst case (first read out) equals 5 % relative to the step jump of radon concentration. This is due to the increase of activity of the decay products in the chamber. It was observed that the short lived radon decay products (Po-218, Pb-214, Bi-214) are depositing on the walls of the chamber and they are not removed by flushing the chamber with air. (author)

  12. Radon measurements technique in air using a track plastic detector

    International Nuclear Information System (INIS)

    Pereira, J.F.A.; Silva Estrada, J.J. da; Binns, D.A.C.; Urban, M.

    1983-01-01

    A difusion chamber is used to measure the radon concentration in air through alpha particles tracks in Makrofol E, 300μm thick. This system was developed by Karlsruhe Nuclear Research Centre, Germany, and is already used by the Occupational Radiological Protection Department of IRD/CNEN, for premilimar measurements in Pocos de Caldas and Rio de Janeiro. In the chamber, the plastic detector is set at the lower end and a filter is placed at the upper end. In this way, a known volume is defined in the detector system. To amplify the tracks produced by the alpha particles due to radon and short-lived dadon-daughter products, an electrochemical system is employed. Some theoretical questions about the treeing produced by the electrochemical etching, the detector characteristics, as well as the adapted statistics model are also discussed. (Author) [pt

  13. Measurement of acetates in air using differential ion mobility spectrometer

    Science.gov (United States)

    Szczurek, Andrzej; Maciejewska, Monika; Zajiczek, Żaneta; Maziejuk, Mirosław

    2017-11-01

    Volatile organic compounds are one of the most important group of air pollutants. Potential health and environmental problems resulting from their emission prompted the requirement for monitoring these species. It motivates development of new measurement techniques which are fast, cost effective, reliable and field deployable. One of novel approaches is ion mobility spectrometry. It dwells on ion separation in electric field, based on differences in ion mobility. Many variants of this method are developed. In this wok, differential ion mobility spectrometry (DMS) was considered in respect of acetate measurements in air. It was demonstrated that DMS offers linear response to methyl, ethyl, propyl and butyl acetate in concentration range from 0.3 ppm to 7 ppm. Positive ions spectrum has to be utilised for this purpose. We showed that fragments of DMS spectrum which secure linearity are compound-specific. The obtained results are promising from the application point of view.

  14. Continuous measurement of radon concentration in air with Lucas cell

    International Nuclear Information System (INIS)

    Machaj, B.; Urbanski, P.

    1998-01-01

    Lucas cell was investigated as alpha radiation detector for continuous measurement of radon concentration in air with air sampling by means of the pump. The investigations carried out indicate that short lived radon decay products inside of the Lucas chamber with dimensions φ54x74 mm (0.17L) attach to the internal walls of the cell and are not removed when the cell is flushed with fresh air. This effect and the known effect of increase of radon daughters concentration when pure radon is introduced into the cell results in delay of response of the gage to variations of radon concentration. The response of the gage is considered and signal processing is suggested that can be useful in continuous measurement of radon concentration. (author)

  15. A diffusive sampling device for measurement of ammonia in air

    Science.gov (United States)

    Yamada, Tomomi; Uchiyama, Shigehisa; Inaba, Yohei; Kunugita, Naoki; Nakagome, Hideki; Seto, Hiroshi

    2012-07-01

    A diffusive sampling device, the DSD-NH3, has been developed for measurement of ammonia in air. The DSD-NH3 comprises silica gel impregnated with phosphoric acid as the absorbent, a porous sintered polyethylene tube that acts as a diffusive membrane, and a small polypropylene syringe that is used for the elution of analytes from the absorbent. Silica gel impregnated with phosphoric acid is used as absorbent for the DSD-NH3; basic gases in ambient air, including ammonia, are trapped in the DSD-NH3 device by their reaction with phosphoric acid in the sampler to form their corresponding phosphoric acid salts. After collection, the DSD-NH3 samplers are eluted by water. Cations in the eluate, including ammonium ions, are analyzed by ion chromatography. A side-by-side comparison was made with active samplers, demonstrating good correlation (r2 = 0.996). The sampling rate (94.5 ml min-1) was determined from comparison with an active sampling method and sampling rates. The sampling rate is also calculated from the respective molecular weights according to a rule based on Graham's law. The theoretical sampling rate with the DSD-NH3 is 95.4 ml min-1 and agrees with the experimental value (94.5 ml min-1). Little influence of wind velocity on the sampler was observed. The relative standard deviations for ammonia concentrations were 4.7% with face velocity ranging 0-5.0 m/s.

  16. Optimisation of key performance measures in air cargo demand management

    Directory of Open Access Journals (Sweden)

    Alexander May

    2014-03-01

    Full Text Available This article sought to facilitate the optimisation of key performance measures utilised for demand management in air cargo operations. The focus was on the Revenue Management team at Virgin Atlantic Cargo and a fuzzy group decision-making method was used. Utilising intelligent fuzzy multi-criteria methods, the authors generated a ranking order of ten key outcome-based performance indicators for Virgin Atlantic air cargo Revenue Management. The result of this industry-driven study showed that for Air Cargo Revenue Management, ‘Network Optimisation’ represents a critical outcome-based performance indicator. This collaborative study contributes to existing logistics management literature, especially in the area of Revenue Management, and it seeks to enhance Revenue Management practice. It also provides a platform for Air Cargo operators seeking to improve reliability values for their key performance indicators as a means of enhancing operational monitoring power.

  17. Large Gain in Air Quality Compared to an Alternative Anthropogenic Emissions Scenario

    Science.gov (United States)

    Daskalakis, Nikos; Tsigaridis, Kostas; Myriokefalitakis, Stelios; Fanourgakis, George S.; Kanakidou, Maria

    2016-01-01

    During the last 30 years, significant effort has been made to improve air quality through legislation for emissions reduction. Global three-dimensional chemistrytransport simulations of atmospheric composition over the past 3 decades have been performed to estimate what the air quality levels would have been under a scenario of stagnation of anthropogenic emissions per capita as in 1980, accounting for the population increase (BA1980) or using the standard practice of neglecting it (AE1980), and how they compare to the historical changes in air quality levels. The simulations are based on assimilated meteorology to account for the yearto- year observed climate variability and on different scenarios of anthropogenic emissions of pollutants. The ACCMIP historical emissions dataset is used as the starting point. Our sensitivity simulations provide clear indications that air quality legislation and technology developments have limited the rapid increase of air pollutants. The achieved reductions in concentrations of nitrogen oxides, carbon monoxide, black carbon, and sulfate aerosols are found to be significant when comparing to both BA1980 and AE1980 simulations that neglect any measures applied for the protection of the environment. We also show the potentially large tropospheric air quality benefit from the development of cleaner technology used by the growing global population. These 30-year hindcast sensitivity simulations demonstrate that the actual benefit in air quality due to air pollution legislation and technological advances is higher than the gain calculated by a simple comparison against a constant anthropogenic emissions simulation, as is usually done. Our results also indicate that over China and India the beneficial technological advances for the air quality may have been masked by the explosive increase in local population and the disproportional increase in energy demand partially due to the globalization of the economy.

  18. Intercomparison of different instruments for measuring radon concentration in air

    International Nuclear Information System (INIS)

    Shimo, Michikuni; Iida, Takao

    1990-01-01

    An intercomparison of different instruments for measurement of radon concentration was carried out. The instruments include an ionization chamber, the charcoal-trap method, a flow-type ionization chamber (pulse-counting method), a two-filter method, an electrostatic collection method and a passive integration radon monitor. All instruments except for the passive radon monitor have been calibrated independently. Measurements were performed over a concentration range from about 3.5 Bq·m -3 (in outdoor air) to 110 Bq·m -3 (in indoor air). The results obtained by these techniques, except the two-filter technique, are comparable. Radon daughter concentration measured using a filter-sampling method was about 52% of radon concentration. (author)

  19. Intercomparison of different instruments that measure radon concentration in air

    International Nuclear Information System (INIS)

    Shimo, M.; Iida, T.; Ikebe, Y.

    1987-01-01

    An intercomparison of different instruments for measurement of radon concentration was carried out. The instruments include an ionization chamber, the charcoal-trap technique, a flow-type ionization chamber (pulse-counting technique), a two-filter method, an electrostatic collection method and a passive integrating radon monitor. All instruments except for the passive radon monitor have been calibrated independently. Measurements were performed over a concentration range from about 3.5 Bq/m/sup 3/ (in outdoor air) to 110 Bq/m/sup 3/ (in indoor air). The results obtained from these techniques, except the two-filter technique, are comparable. Radon daughter concentration measured using a filter-sampling technique was about 52% of radon concentrations

  20. Measurement of nonlinear refractive index and ionization rates in air using a wavefront sensor.

    Science.gov (United States)

    Schwarz, Jens; Rambo, Patrick; Kimmel, Mark; Atherton, Briggs

    2012-04-09

    A wavefront sensor has been used to measure the Kerr nonlinear focal shift of a high intensity ultrashort pulse beam in a focusing beam geometry while accounting for the effects of plasma-defocusing. It is shown that plasma-defocusing plays a major role in the nonlinear focusing dynamics and that measurements of Kerr nonlinearity and ionization are coupled. Furthermore, this coupled effect leads to a novel way that measures the laser ionization rates in air under atmospheric conditions as well as Kerr nonlinearity. The measured nonlinear index n₂ compares well with values found in the literature and the measured ionization rates could be successfully benchmarked to the model developed by Perelomov, Popov, and Terentev (PPT model) [Sov. Phys. JETP 50, 1393 (1966)].

  1. Disruptive Innovation in Air Measurement Technology: Reality or Hype?

    Science.gov (United States)

    This presentation is a big picture overview on the changing state of air measurement technology in the world, with a focus on the introduction of low-cost sensors into the market place. The presentation discusses how these new technologies may be a case study in disruptive innov...

  2. Progress in air shower radio measurements : detection of distant events

    NARCIS (Netherlands)

    Bähren, L.; Buitink, S.J.; Falcke, H.D.E.; Horneffer, K.H.A.; Kuijpers, J.M.E.; Lafebre, S.J.; Nigl, A.; Petrovic, J.; Singh, K.

    2006-01-01

    Data taken during half a year of operation of 10 LOPES antennas (LOPES-10), triggered by EAS observed with KASCADE-Grande have been analysed. We report about the analysis of correlations of radio signals measured by LOPES-10 with extensive air shower events reconstructed by KASCADE-Grande, including

  3. Incorporation monitoring by measurements of activity concentrations in air

    International Nuclear Information System (INIS)

    Breukelmann, G.; Dalheimer, A.; Dilger, H.; Henrichs, K.

    1997-01-01

    The incorporation monitoring of workers handling actinides is in many cases not possible by individual methods: The sensitivity of bioassay of methods (in vivo, in vitro) is not sufficient to detect amounts as required by the low annual limits of intake. Similar difficulties may occur with the use of radionuclides with very short physical half-lives. In these cases, the measuring of activity concentrations in the air is the only way to monitor the workers and to meet legal requirements. The essential problem connected with this approach is to make sure, that the air sample analyzed represents the average air inhaled actually. Correspondingly, the new system regulating the incorporation monitoring in Germany requires additional measures to ensure this representatively. (author)

  4. Walkie-Talkie Measurements for the Speed of Radio Waves in Air

    Science.gov (United States)

    Dombi, Andra; Tunyagi, Arthur; Neda, Zoltan

    2013-01-01

    A handheld emitter-receiver device suitable for the direct estimation of the velocity of radio waves in air is presented. The velocity of radio waves is measured using the direct time-of-flight method, without the need for any tedious and precise settings. The results for two measurement series are reported. Both sets of results give an estimate…

  5. High-accuracy long-distance measurements in air with a frequency comb laser

    NARCIS (Netherlands)

    Cui, M.; Zeitouny, M.G.; Bhattacharya, N.; Van den Berg, S.A.; Urbach, H.P.; Braat, J.J.M.

    2009-01-01

    We experimentally demonstrate that a femtosecond frequency comb laser can be applied as a tool for longdistance measurement in air. Our method is based on the measurement of cross correlation between individual pulses in a Michelson interferometer. From the position of the correlation functions,

  6. Effect of cigarette smoke on the measured equivalent volume activity of 222Rn in air

    International Nuclear Information System (INIS)

    Tuckova, S.; Tykva, R.

    1994-01-01

    The effect of cigarette smoke in air on the increase of the measured equivalent volume activity of 222 Rn is demonstrated. After introduction of the smoke from one cigarette into 1 m 3 of air, this value increased up to ten times as shown be the method of sucking air through a filter. (author) 5 refs.; 1 fig

  7. Temperature retrieval from Rayleigh-Brillouin scattering profiles measured in air

    NARCIS (Netherlands)

    Witschas, B.; Ubachs, W.M.G.

    2014-01-01

    In order to investigate the performance of two different algorithms for retrieving temperature from Rayleigh-Brillouin (RB) line shapes, RB scattering measurements have been performed in air at a wavelength of 403 nm, for a temperature range from 257 K to 330 K, and atmospherically relevant

  8. Experimental measurement of fluid force coefficients for helical tube arrays in air cross flow

    International Nuclear Information System (INIS)

    Shen Shifang; Liu Reilan

    1993-01-01

    A helical coil steam generator is extensively used in the High Temperature Gas Cooled Reactor (HTGCR) and Sodium Cooled Reactor (SCR) nuclear power stations because of its compact structure, good heat-exchange, and small volume. The experimental model is established by the structure parameter of 200MW HTGCR. The fluid elastic instability of helical tube arrays in air cross flow is studied in this experiment, and the fluid force coefficients of helical tube arrays having the same notational direction of two adjacent layers in air cross flow are obtained. As compared to the fluid force coefficients of cylinder tube arrays, the fluid force coefficients of helical tube arrays are smaller in the low velocity area, and greater in the high velocity area. The experimental results help the study of the dynamic characteristics of helical tube arrays in air cross flow

  9. Refractive index and geometrical thickness measurement of a transparent pellicle in air by Gaussian beam defocusing.

    Science.gov (United States)

    Olvera-R, Octavio; Cywiak, Moisés; Cervantes-L, Joel; Morales, Arquímedes

    2014-04-10

    We demonstrate that it is possible to measure the local geometrical thickness and the refractive index of a transparent pellicle in air by combining the diffractive properties of a Gaussian beam with the analytical equations of the light that propagates through a thin layer. We show that our measurement technique is immune to inherent piston-like vibrations present in the pellicle. As our measurements are based on characterizing properly the Gaussian beam in a plane of detection, a homodyne technique for this purpose is devised and described. The feasibility of our proposal is confirmed by measuring local geometrical thicknesses and the refractive index of a commercially available stretch film.

  10. Measurement of the muon content in air showers at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Veberič Darko

    2016-01-01

    Full Text Available The muon content of extensive air showers produced by ultra-high energy cosmic rays is an observable sensitive to the composition of primary particles and to the properties of hadronic interactions governing the evolution of air-shower cascades. We present different methods for estimation of the number of muons at the ground and the muon production depth. These methods use measurements of the longitudinal, lateral, and temporal distribution of particles in air showers recorded by the detectors of the Pierre Auger Observatory. The results, obtained at about 140 TeV center-of-mass energy for proton primaries, are compared to the predictions of LHC-tuned hadronic-interaction models used in simulations with different primary masses. The models exhibit a deficitin the predicted muon content. The combination of these results with other independent mass composition analyses, such as those involving the depth of shower maximum observablemax, provide additional constraints on hadronic-interaction models for energies beyond the reach of the LHC.

  11. A Comparative Study of Sound Speed in Air at Room Temperature between a Pressure Sensor and a Sound Sensor

    Science.gov (United States)

    Amrani, D.

    2013-01-01

    This paper deals with the comparison of sound speed measurements in air using two types of sensor that are widely employed in physics and engineering education, namely a pressure sensor and a sound sensor. A computer-based laboratory with pressure and sound sensors was used to carry out measurements of air through a 60 ml syringe. The fast Fourier…

  12. A comparative study on laser induced shock cleaning of radioactive contaminants in air and water

    Science.gov (United States)

    Kumar, Aniruddha; Prasad, Manisha; Bhatt, R. B.; Behere, P. G.; Biswas, D. J.

    2018-03-01

    Efficient removal of Uranium-di-oxide (UO2) particulates from stainless steel surface was effected by Nd-YAG laser induced plasma shock waves in air as well as in water environment. The propagation velocity of the generated shock wave was measured by employing the photo-acoustic probe deflection method. Monitoring of the alpha activity of the sample with a ZnS (Ag) scintillation detector before and after the laser exposure allowed the estimation of decontamination efficiency defined as the percentage removal of the initial activity. Experiments were carried out to study the effect of laser pulse energy, number of laser exposures, orientation of the sample, the separation between the substrate surface and the onset point of the shock wave on the de-contamination efficiency. The most optimised cleaning was found to occur when the laser beam impinged normally on the sample that was immersed in water and placed at a distance of ∼0.7 mm from the laser focal spot. Analysis of the cleaned surface by optical microscopes established that laser induced shock cleaning in no way altered the surface property. The shock force generated in both air and water has been estimated theoretically and has been found to exceed the Van der Waal's binding force for spherical contaminant particulate.

  13. Simple method of measuring laser peak intensity inside femtosecond laser filament in air.

    Science.gov (United States)

    Xu, Shengqi; Sun, Xiaodong; Zeng, Bin; Chu, Wei; Zhao, Jiayu; Liu, Weiwei; Cheng, Ya; Xu, Zhizhan; Chin, See Leang

    2012-01-02

    Measurement of laser intensity inside a femtosecond laser filament is a challenging task. In this work, we suggest a simple way to characterize laser peak intensity inside the filament in air. It is based on the signal ratio measurement of two nitrogen fluorescence lines, namely, 391 nm and 337 nm. Because of distinct excitation mechanisms, the signals of the two fluorescence lines increase with the laser intensity at different orders of nonlinearity. An empirical formula has been deduced according to which laser peak intensity could be simply determined by the fluorescence ratio.

  14. Measuring and Comparing Energy Flexibilities

    DEFF Research Database (Denmark)

    Valsomatzis, Emmanouil; Hose, Katja; Pedersen, Torben Bach

    2015-01-01

    Flexibility in energy supply and demand becomes more and more important with increasing Renewable Energy Sources (RES) production and the emergence of the Smart Grid. So-called prosumers, i.e., entities that produce and/or consume energy, can offer their inherent flexibilities through so......-called demand response and thus help stabilize the energy markets. Thus, prosumer flexibility becomes valuable and the ongoing Danish project TotalFlex [1] explores the use of prosumer flexibility in the energy market using the concept of a flex-offer [2], which captures energy flexibilities in time and...... induced by time and amount individually, and by their com- bination. To this end, we introduce several flexibility measures that take into account the combined effect of time and energy on flex-offer flexibility and discuss their respective pros and cons through a number of realistic examples....

  15. Measurements of diurnal concentration variations of gaseous HCl in air in the subnanogram range

    Energy Technology Data Exchange (ETDEWEB)

    Matusca, P.; Schwarz, B.; Baechmann, K.

    1984-01-01

    A method of measuring gaseous HCl based on diffusion samplers has been developed. This sampling method allows a filterless dynamic gas-aerosol separation. After thermal desorption, HCl is converted into 2-chlorocyclohexanol by gas-phase reaction with 7-oxabicyclo(4.1.0)heptane. The derivatization product is analyzed by GC-separation using an electrolytic conductivity detector (HECD). The minimum concentration detectable is: 40 pptv HCl. Several results of measurements of gaseous HCl in air are reported. Gaseous HCl is present in concentrations between about 0.1 and 1.4 ng l/sup -1/ at STP in rural areas and 0.2 and 3.0 ng l/sup -1/ at STP in urban areas. Diurnal and spatial variations and the influence of climate were measured and are discussed.

  16. Measurements of diurnal concentration variations of gaseous HCl in air in the sub-nanogram range

    Science.gov (United States)

    Matusca, P.; Schwarz, B.; Bächmann, K.

    A method of measuring gaseous HCl based on diffusion samplers has been developed. This sampling method allows a filterless dynamic gas-aerosol separation. After thermal desorption, HCl is converted into 2-chlorocyclohexanol by gas-phase reaction with 7-oxabicyclo(4.1.0)heptane. The derivatization product is analysed by GC-separation using an electrolytic conductivity detector (HECD). The minimum concentration detectable is: 40 pptv HCl. Several results of measurements of gaseous HCl in air are reported. Gaseous HCl is present in concentrations between about 0.1 and 1.4 ngℓ -1 at STP in rural areas and 0.2 and 3.0 ng ℓ -1 at STP in urban areas. Diurnal and spatial variations and the influence of climate were measured and are discussed.

  17. Nitric oxide density measurements in air and air/fuel nanosecond pulse discharges by laser induced fluorescence

    Science.gov (United States)

    Uddi, M.; Jiang, N.; Adamovich, I. V.; Lempert, W. R.

    2009-04-01

    Laser induced fluorescence is used to measure absolute nitric oxide concentrations in air, methane-air and ethylene-air non-equilibrium plasmas, as a function of time after initiation of a single pulse, 20 kV peak voltage, 25 ns pulse duration discharge. A mixture of NO and nitrogen with known composition (4.18 ppm NO) is used for calibration. Peak NO density in air at 60 Torr, after a single pulse, is ~8 × 1012 cm-3 (~4.14 ppm) occurring at ~250 µs after the pulse, with decay time of ~16.5 ms. Peak NO atom mole fraction in a methane-air mixture with equivalence ratio of phiv = 0.5 is found to be approximately equal to that in air, with approximately the same rise and decay rate. In an ethylene-air mixture (also with equivalence ratio of phiv = 0.5), the rise and decay times are comparable to air and methane-air, but the peak NO concentration is reduced by a factor of approximately 2.5. Spontaneous emission measurements show that excited electronic states N2(C 3Π) and NO(A 2Σ) in air at P = 60 Torr decay within ~20 ns and ~1 µs, respectively. Kinetic modelling calculations incorporating air plasma kinetics complemented with the GRI Mech 3.0 hydrocarbon oxidation mechanism are compared with the experimental data using three different NO production mechanisms. It is found that NO concentration rise after the discharge pulse is much faster than predicted by Zel'dovich mechanism reactions, by two orders of magnitude, but much slower compared with reactions of electronically excited nitrogen atoms and molecules, also by two orders of magnitude. It is concluded that processes involving long lifetime (~100 µs) metastable states, such as N2(X 1Σ,v) and O2(b 1Σ), formed by quenching of the metastable N2(A 3Σ) state by ground electronic state O2, may play a dominant role in NO formation. NO decay, in all cases, is found to be dominated by the reverse Zel'dovich reaction, NO + O → N + O2, as well as by conversion into NO2 in a reaction of NO with ozone.

  18. Nitric oxide density measurements in air and air/fuel nanosecond pulse discharges by laser induced fluorescence

    International Nuclear Information System (INIS)

    Uddi, M; Jiang, N; Adamovich, I V; Lempert, W R

    2009-01-01

    Laser induced fluorescence is used to measure absolute nitric oxide concentrations in air, methane-air and ethylene-air non-equilibrium plasmas, as a function of time after initiation of a single pulse, 20 kV peak voltage, 25 ns pulse duration discharge. A mixture of NO and nitrogen with known composition (4.18 ppm NO) is used for calibration. Peak NO density in air at 60 Torr, after a single pulse, is ∼8 x 10 12 cm -3 (∼4.14 ppm) occurring at ∼250 μs after the pulse, with decay time of ∼16.5 ms. Peak NO atom mole fraction in a methane-air mixture with equivalence ratio of ψ = 0.5 is found to be approximately equal to that in air, with approximately the same rise and decay rate. In an ethylene-air mixture (also with equivalence ratio of ψ = 0.5), the rise and decay times are comparable to air and methane-air, but the peak NO concentration is reduced by a factor of approximately 2.5. Spontaneous emission measurements show that excited electronic states N 2 (C 3 Π) and NO(A 2 Σ) in air at P = 60 Torr decay within ∼20 ns and ∼1 μs, respectively. Kinetic modelling calculations incorporating air plasma kinetics complemented with the GRI Mech 3.0 hydrocarbon oxidation mechanism are compared with the experimental data using three different NO production mechanisms. It is found that NO concentration rise after the discharge pulse is much faster than predicted by Zel'dovich mechanism reactions, by two orders of magnitude, but much slower compared with reactions of electronically excited nitrogen atoms and molecules, also by two orders of magnitude. It is concluded that processes involving long lifetime (∼100 μs) metastable states, such as N 2 (X 1 Σ,v) and O 2 (b 1 Σ), formed by quenching of the metastable N 2 (A 3 Σ) state by ground electronic state O 2 , may play a dominant role in NO formation. NO decay, in all cases, is found to be dominated by the reverse Zel'dovich reaction, NO + O → N + O 2 , as well as by conversion into NO 2 in a reaction

  19. Measurements of the spatial distribution of tritium in air above a chronically contaminated surface

    International Nuclear Information System (INIS)

    Workman, W.J.G.; Davis, P.A.; Wood, M.J.; Barry, P.J.

    1993-01-01

    Tritium in air (HTO) concentrations were measured over a 13 month period above a surface that is chronically contaminated by tritium-bearing groundwater from a waste management area. The measurements were made using passive diffusion samplers, which were sited at six locations (about 100 m apart) at 0.15, 0.9, and 1.8 m above ground level. The diffusion samplers were compact, sampled at a known rate, and required no external power source. They are ideal for remote locations and require a minimum of effort to collect and analyze the data. HTO-in-air concentration peaked in the summer at 500-1500 Bq.m -3 and decreased in the winter to 1-120 Bq.m -3 . In general, concentration decreased with height above ground level, implying that HTO is being lost from the surface to the atmosphere. The flux of tritium to the atmosphere must, therefore, be taken into account to estimate the tritium mass balance for a contaminated area. (Author) 3 figs., 5 tabs., 10 refs

  20. Measurement of radon concentration in air employing Lucas chamber; Pomiar koncentracji radonu za pomoca komory Lucasa

    Energy Technology Data Exchange (ETDEWEB)

    Machaj, B.

    1997-12-31

    The results of investigations aimed to determine the main features of radon concentration gauge in air, employing 0.17 L Lucas chamber, and air sample forced by an air pump are presented. For two hour sampling and measuring cycle time the dynamic error in the worst case (first read out) equals 5 % relative to the step jump of radon concentration. This is due to the increase of activity of the decay products in the chamber. It was observed that the short lived radon decay products (Po-218, Pb-214, Bi-214) are depositing on the walls of the chamber and they are not removed by flushing the chamber with air. (author). 4 refs, 19 figs, 2 tabs.

  1. Measurement of HOx· production rate due to radon decay in air

    International Nuclear Information System (INIS)

    Ding, Huiling.

    1993-08-01

    Radon in indoor air may cause the exposure of the public to excessive radioactivity. Radiolysis of water vapor in indoor air due to radon decay could produce (·OH and HO 2 ·) that may convert atmospheric constituents to compounds of lower vapor pressure. These lower vapor pressure compounds might then nucleate to form new particles in the indoor atmosphere. Chemical amplification was used to determine HO x · production rate in indoor air caused by radon decay. Average HO x · production rate was found to be (4.31±0.07) x 10 5 HO x · per Rn decay per second (Bq) 3.4 to 55.0% at 22C. This work provided G (HO x ·) -value, 7.86±0.13 No./100 eV in air by directly measuring [HO x ·] formed from the radiolysis procedure. This G value implies that HO x · produced by radon decay in air might be formed by multiple processes and may be result of positive ion-molecule reactions, primary radiolysis, and radical reactions. There is no obvious relation between HO x · production rate and relative humidity. A laser-induced fluorescence (LIF) system has been used for ·OH production rate measurement; it consists of an excimer laser, a dye laser, a frequency doubler, a gaseous fluorescence chamber, and other optical and electronic parts. This system needs to be improved to eliminate the interferences of light scattering and artificial ·OH produced from the photolysis of O 3 /H 2 O

  2. Radon measurements in air in waterworks and indoor swimming pools - a primary mapping project

    International Nuclear Information System (INIS)

    Marinko, J.; Mjoenes, L.; Soederman, A.-L.

    2004-01-01

    In 2001 the Swedish Work Environment Authority asked five regional offices around the country; Falun, Malmoe, Vaexjoe, Umeaa and Oerebro, to measure radon in air in workplaces where water was likely to enhance radon levels indoors. Track etch detectors were used and placed in workplaces according to the SSI measurement protocol for determining the annual average radon concentration in homes. Rooms that are frequently used by employees were measured. The detectors were exposed between 1 to 3 months. 225 detectors were used in the project and analysed at the same laboratory. The results showed that the radon concentration in waterworks often is high. Measurements were made in 60 waterworks. Levels exceeding 1000 Bq/m 3 were found in 49 of them and levels exceeding 4000 Bq/m 3 were found in 21 waterworks. The variation between waterworks may be a result of the radon concentration in the raw water, the amount of radon gas escaping to the air when water is treated, the air exchange rate in the building and where the detectors were deployed. Measurements were made in 28 indoor swimming baths. The maximum level was 290 Bq/m 3 , but most concentrations were between 30 to 70 Bq/m 3 . The conclusion is that high radon levels do not seem to be a problem in indoor swimming baths. Maybe this is due to good ventilation or the fact that water often has been treated for radon before it is used in swimming pools. The results from measurement in food industries such as breweries showed no extreme radon levels except for a fish farm where levels over 1000 Bq/m 3 were measured in the farming room and 790 Bq/m 3 in the office. The radon concentrations in laundries were relatively low, between 30 and 170 Bq/m 3

  3. New particle formation in air mass transported between two measurement sites in Northern Finland

    Directory of Open Access Journals (Sweden)

    M. Komppula

    2006-01-01

    Full Text Available This study covers four years of aerosol number size distribution data from Pallas and Värriö sites 250 km apart from each other in Northern Finland and compares new particle formation events between these sites. In air masses of eastern origin almost all events were observed to start earlier at the eastern station Värriö, whereas in air masses of western origin most of the events were observed to start earlier at the western station Pallas. This demonstrates that particle formation in a certain air mass type depends not only on the diurnal variation of the parameters causing the phenomenon (such as photochemistry but also on some properties carried by the air mass itself. The correlation in growth rates between the two sites was relatively good, which suggests that the amount of condensable vapour causing the growth must have been at about the same level in both sites. The condensation sink was frequently much higher at the downwind station. It seems that secondary particle formation related to biogenic sources dominate in many cases over the particle sinks during the air mass transport between the sites. Two cases of transport from Pallas to Värriö were further analysed with an aerosol dynamics model. The model was able to reproduce the observed nucleation events 250 km down-wind at Värriö but revealed some differences between the two cases. The simulated nucleation rates were in both cases similar but the organic concentration profiles that best reproduced the observations were different in the two cases indicating that divergent formation reactions may dominate under different conditions. The simulations also suggested that organic compounds were the main contributor to new particle growth, which offers a tentative hypothesis to the distinct features of new particles at the two sites: Air masses arriving from the Atlantic Ocean typically spent approximately only ten hours over land before arriving at Pallas, and thus the time for the

  4. Comparing Laboratory and Field Measured Bioaccumulation Endpoints

    NARCIS (Netherlands)

    Burkhard, L. P.; Arnot, J. A.; Embry, M. R.; Farley, K. J.; Hoke, R. A.; Kitano, M.; Leslie, H.A.; Lotufo, G. R.; Parkerton, T.F.; Sappington, K.G.; Tomy, G. T.; Woodburn, K.B.

    2011-01-01

    An approach for comparing laboratory and field measures of bioaccumulation is presented to facilitate the interpretation of different sources of bioaccumulation data. Differences in numerical scales and units are eliminated by converting the data to dimensionless fugacity (or

  5. Comparative effectiveness of malaria preventive measures on ...

    African Journals Online (AJOL)

    The burden of malaria and its associated problems in pregnancy can be reduced by the use of different malaria preventive measures. This study was conducted to determine the comparative effectiveness of three different malaria preventive measures on populations of parturient in Abeokuta, Ogun State, Nigeria.

  6. Laboratory measurements of single light scattering by ensembles of randomly oriented small irregular particles in air. A review

    NARCIS (Netherlands)

    Muñoz, O.; Hovenier, J.W.

    2011-01-01

    In this paper we present an overview of light scattering experiments devoted to measure one or more elements of the scattering matrix as functions of the scattering angle of ensembles of randomly oriented small irregular particles in air. A summary of the most important findings in light scattering

  7. Mobile Air Monitoring: Measuring Change in Air Quality in the City of Hamilton, 2005-2010

    Science.gov (United States)

    Adams, Matthew D.; DeLuca, Patrick F.; Corr, Denis; Kanaroglou, Pavlos S.

    2012-01-01

    This paper examines the change in air pollutant concentrations between 2005 and 2010 occurring in the City of Hamilton, Ontario, Canada. After analysis of stationary air pollutant concentration data, we analyze mobile air pollutant concentration data. Air pollutants included in the analysis are CO, PM[subscript 2.5], SO[subscript 2], NO,…

  8. On the measurement of comparative advantage

    NARCIS (Netherlands)

    Hoen, A.R.; Oosterhaven, J.

    This paper shows-that the standard measure of revealed comparative advantage (RCA), ranging from 0 to infinity, has problematic properties. Due to its multiplicative specification, it has a moving mean larger than its expected value of 1, while its distribution strongly depends on the number of

  9. An index to measure depreciation in air quality in some coal mining areas of Korba industrial belt of Chhattisgarh, India.

    Science.gov (United States)

    Singh, Gurdeep

    2006-11-01

    The comparison with National Ambient Air Quality Standards does not always depict a true picture of the Air Quality Status of a study area. As an alternative an index that measures depreciation in Air Quality on more realistic terms has been proposed and applied to the ambient air monitoring data collected from some areas of Korba Coalfields in India. Results have been discussed in detail to illustrate the application of the proposed index and utility in bringing out more realistic air quality assessment.

  10. [Comparative quality measurements part 3: funnel plots].

    Science.gov (United States)

    Kottner, Jan; Lahmann, Nils

    2014-02-01

    Comparative quality measurements between organisations or institutions are common. Quality measures need to be standardised and risk adjusted. Random error must also be taken adequately into account. Rankings without consideration of the precision lead to flawed interpretations and enhances "gaming". Application of confidence intervals is one possibility to take chance variation into account. Funnel plots are modified control charts based on Statistical Process Control (SPC) theory. The quality measures are plotted against their sample size. Warning and control limits that are 2 or 3 standard deviations from the center line are added. With increasing group size the precision increases and so the control limits are forming a funnel. Data points within the control limits are considered to show common cause variation; data points outside special cause variation without the focus of spurious rankings. Funnel plots offer data based information about how to evaluate institutional performance within quality management contexts.

  11. Measurement of volumic activities of radon in air in houses and in working rooms with solid state nuclear track detectors

    International Nuclear Information System (INIS)

    Hakam, O.K.

    1993-01-01

    In this work, a new method of measuring volumic activity of radon has been developed. This method is based on using solid state nuclear track detectors LR-115 type II. It has been applied to measurement of volumic activities of radon in air in houses and in working rooms in different regions of Morocco. These measurements, carried out for the first time in the country, allowed to estimate the dose equivalents of radon received by the population of the studied regions. 59 refs., 38 figs., 38 tabs. (F.M.)

  12. Studying the possibility of recharging E-Perm for radon measurement in air

    International Nuclear Information System (INIS)

    Shweikani, R.; Bardan, R.

    2011-03-01

    In this work recharging electret detectors and studying their responding for radioactive gases (radon gas) was studied and the results were compared with solid state nuclear detectors (CR-39). After several experiments we found that using a metal nozzle which is connected to a high voltage supply (poling method) was useful to polarize the electret material and get a stable electrostatic charge. The stability of electret was studied after each experiment ,the results showed that the best charging parameters were: (7 mm as a nozzle height.- 15 sec as a charging time.- 5 kV as a charging voltage). Depending on the charging and stability studying results the electrets were calibrated in radon calibration cell and the calibration factors were defined The charged electrets were examined to measure radon concentration in the open environmental and were compared with CR-39 detectors; the charged electrets appeared a liner response for radon gas as CR-39 detectors.(author)

  13. Feasibility of measuring temperature and density fluctuations in air using laser-induced O2 fluorescence

    Science.gov (United States)

    Massey, G. A.; Lemon, C. J.

    1984-01-01

    A tunable line-narrowed ArF laser can selectively excite several rotation al lines of the Schumann-Runge band system of O2 in air. The resulting ultraviolet fluorescence can be monitored at 90 deg to the laser beam axis, permitting space and time resolved observation of density and temperature fluctuations in turbulence. Experiments and calculations show that + or - 1 K, + or - 1 percent density, 1 cu mm spatial, and 1 microsecond temporal resolution can be achieved simultaneously under some conditions.

  14. Electric field measurements in nanosecond pulse discharges in air over liquid water surface

    Science.gov (United States)

    Simeni Simeni, Marien; Baratte, Edmond; Zhang, Cheng; Frederickson, Kraig; Adamovich, Igor V.

    2018-01-01

    Electric field in nanosecond pulse discharges in ambient air is measured by picosecond four-wave mixing, with absolute calibration by a known electrostatic field. The measurements are done in two geometries, (a) the discharge between two parallel cylinder electrodes placed inside quartz tubes, and (b) the discharge between a razor edge electrode and distilled water surface. In the first case, breakdown field exceeds DC breakdown threshold by approximately a factor of four, 140 ± 10 kV cm-1. In the second case, electric field is measured for both positive and negative pulse polarities, with pulse durations of ˜10 ns and ˜100 ns, respectively. In the short duration, positive polarity pulse, breakdown occurs at 85 kV cm-1, after which the electric field decreases over several ns due to charge separation in the plasma, with no field reversal detected when the applied voltage is reduced. In a long duration, negative polarity pulse, breakdown occurs at a lower electric field, 30 kV cm-1, after which the field decays over several tens of ns and reverses direction when the applied voltage is reduced at the end of the pulse. For both pulse polarities, electric field after the pulse decays on a microsecond time scale, due to residual surface charge neutralization by transport of opposite polarity charges from the plasma. Measurements 1 mm away from the discharge center plane, ˜100 μm from the water surface, show that during the voltage rise, horizontal field component (Ex ) lags in time behind the vertical component (Ey ). After breakdown, Ey is reduced to near zero and reverses direction. Further away from the water surface (≈0.9 mm), Ex is much higher compared to Ey during the entire voltage pulse. The results provide insight into air plasma kinetics and charge transport processes near plasma-liquid interface, over a wide range of time scales.

  15. Simultaneous measurements of temperature and density in air flows using UV laser spectroscopy

    Science.gov (United States)

    Fletcher, D. G.; Mckenzie, R. L.

    1991-01-01

    The simultaneous measurement of temperature and density using laser-induced fluorescence of oxygen in combination with Q-branch Raman scattering of nitrogen and oxygen is demonstrated in a low-speed air flow. The lowest density and temperature measured in the experiment correspond to the freestream values at Mach 5 in the Ames 3.5-Foot Hypersonic Wind Tunnel for stagnation conditions of 100 atm and 1000 K. The experimental results demonstrate the viability of the optical technique for measurements that support the study of compressible turbulence and the validation of numerical codes in supersonic and hypersonic wind tunnel flows.

  16. Spot measurements of radionuclides in air, water and solids with a single instrument

    International Nuclear Information System (INIS)

    Philipsborn, H. von

    1998-01-01

    A unique instrument for measuring environmental radionuclides and novel methods for their concentrative sampling are described here which meet high requirements of sensitivity, easy and reliable handling, and low cost for most applications in field screening, monitoring and training. (author)

  17. High resolution kilometric range optical telemetry in air by radio frequency phase measurement

    Czech Academy of Sciences Publication Activity Database

    Guillory, J.; Šmíd, Radek; García-Márquez, J.; Truong, D.; Alexandre, CH.; Wallerand, J. P.

    2016-01-01

    Roč. 87, č. 7 (2016), 075105:1-6 ISSN 0034-6748 Institutional support: RVO:68081731 Keywords : distance-measuring instrument * index Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.515, year: 2016

  18. Towards Comprehensive Food Security Measures: Comparing Key ...

    African Journals Online (AJOL)

    Food security is a multi-dimensional issue that has been difficult to measure comprehensively, given the one-dimensional focus of existing indicators. Three indicators dominate the food security measurement debate: Household Food Insecurity Access Scale (HFIAS), Dietary Diversity Score (DDS) and Coping Strategies ...

  19. Defining, Measuring, and Comparing Organisational Cultures

    NARCIS (Netherlands)

    van den Berg, Peter T.; Wilderom, Celeste P.M.

    2004-01-01

    La littérature portant sur la culture des organisations souffre d’un manque manifeste d’enquêtes extensives débouchant sur des études comparatives. Afin de rendre plus comparables les cultures organisationnelles, nous proposons une définition et une série de dimensions. La culture organisationnelle

  20. Comparing two measures of mental toughness

    OpenAIRE

    Crust, Lee; Swann, Christian

    2011-01-01

    This paper tested relations between two measures of mental toughness. A sample of 110 male athletes (M age = 20.81 years; SD = 2.76), derived from University sports teams and local sports clubs, gave informed consent before completing two questionnaires to assess mental toughness. It was hypothesized that scales and subscales from the two different instruments, which purported to measure the same or substantially overlapping scales, would be strongly correlated. Predictions concerning the ...

  1. High resolution kilometric range optical telemetry in air by radio frequency phase measurement

    Energy Technology Data Exchange (ETDEWEB)

    Guillory, Joffray; García-Márquez, Jorge; Truong, Daniel; Wallerand, Jean-Pierre [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Šmíd, Radek [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Institute of Scientific Instruments of the CAS, Kralovopolska 147, 612 64 Brno (Czech Republic); Alexandre, Christophe [Centre d’Études et de Recherche en Informatique et Communications (CEDRIC), Cnam, 292 rue St-Martin, 75003 Paris (France)

    2016-07-15

    We have developed an optical Absolute Distance Meter (ADM) based on the measurement of the phase accumulated by a Radio Frequency wave during its propagation in the air by a laser beam. In this article, the ADM principle will be described and the main results will be presented. In particular, we will emphasize how the choice of an appropriate photodetector can significantly improve the telemeter performances by minimizing the amplitude to phase conversion. Our prototype, tested in the field, has proven its efficiency with a resolution better than 15 μm for a measurement time of 10 ms and distances up to 1.2 km.

  2. Application of inertial measuring unit in air navigation for ALS and DAP

    African Journals Online (AJOL)

    This article describes the inertial measuring device IMU, as well as its use in airborne laser scanning and digital aerial photography. This device is used during the operation of a scanning unit and an aerial photo camera. The structure of an additional connection for a digital video camera is proposed, which will record video ...

  3. Highly Sensitive Measurement of Liquid Density in Air Using Suspended Microcapillary Resonators

    Directory of Open Access Journals (Sweden)

    Oscar Malvar

    2015-03-01

    Full Text Available We report the use of commercially available glass microcapillaries as micromechanical resonators for real-time monitoring of the mass density of a liquid that flows through the capillary. The vibration of a suspended region of the microcapillary is optically detected by measuring the forward scattering of a laser beam. The resonance frequency of the liquid filled microcapillary is measured for liquid binary mixtures of ethanol in water, glycerol in water and Triton in ethanol. The method achieves a detection limit in an air environment of 50 µg/mL that is only five times higher than that obtained with state-of-the-art suspended microchannel resonators encapsulated in vacuum. The method opens the door to novel advances for miniaturized total analysis systems based on microcapillaries with the add-on of mechanical transduction for sensing the rheological properties of the analyzed fluids without the need for vacuum encapsulation of the resonators.

  4. Highly sensitive measurement of liquid density in air using suspended microcapillary resonators.

    Science.gov (United States)

    Malvar, Oscar; Ramos, Daniel; Martínez, Carmen; Kosaka, Priscila; Tamayo, Javier; Calleja, Montserrat

    2015-03-30

    We report the use of commercially available glass microcapillaries as micromechanical resonators for real-time monitoring of the mass density of a liquid that flows through the capillary. The vibration of a suspended region of the microcapillary is optically detected by measuring the forward scattering of a laser beam. The resonance frequency of the liquid filled microcapillary is measured for liquid binary mixtures of ethanol in water, glycerol in water and Triton in ethanol. The method achieves a detection limit in an air environment of 50 µg/mL that is only five times higher than that obtained with state-of-the-art suspended microchannel resonators encapsulated in vacuum. The method opens the door to novel advances for miniaturized total analysis systems based on microcapillaries with the add-on of mechanical transduction for sensing the rheological properties of the analyzed fluids without the need for vacuum encapsulation of the resonators.

  5. Radon-thoron measurements in air and soil from some districts of northern part of India

    Directory of Open Access Journals (Sweden)

    Mann Nisha

    2015-01-01

    Full Text Available Radon, thoron and their progenies in the indoor environment are considered as one of the health hazards. The alpha emitting nature of these gases made it possible to detect in indoor environment with the help of nuclear track detector techniques. The soil is the main source of indoor radon as it contains varying amounts of uranium and thorium. Thus the exhalation of radon from soil and its environmental activity needs to be studied. In the present study, the measurement of the indoor radon-thoron from the indoor environment and exhalation from soil are carried out using solid state nuclear track detector technique from Sirsa and Bhiwani districts of northern part of India. The canister technique was used to measure the radon ex- halation rate from the soil samples collected from the study area and pinhole based radon-thoron dosimeters were used to measure indoor radon and thoron concentration. The results show that indoor radon concentration varied from 9 to 28 Bq/m3, with an average of 18.9 Bq/m3 and from 5 to 21 Bq/m3, with an average of 13.8 Bq/m3, for Bhiwani and Sirsa, respectively. Similarly, thoron concentration varied from 14 to 48 Bq/m3, with average of 28.9 Bq/m3 and 27 to 54 Bq/m3, with the average of 39.0 Bq/m3, for Bhiwani and Sirsa, respectively. The mass exhalation rates from soil samples were also measured, to estimate their contribution to indoor radon. A correlation study was carried out between soil exhalation rates and indoor radon concentration.

  6. Video imaging measurement of interfacial wave velocity in air-water flow through a horizontal elbow

    Science.gov (United States)

    Al-Wazzan, Amir; Than, Cheok F.; Moghavvemi, Mahmoud; Yew, Chia W.

    2001-10-01

    Two-phase flow in pipelines containing elbows represents a common situation in the oil and gas industries. This study deals with the stratified flow regime between the gas and liquid phase through an elbow. It is of interest to study the change in wave characteristics by measuring the wave velocity and wavelength at the inlet and outlet of the elbow. The experiments were performed under concurrent air-water stratified flow in a horizontal transparent polycarbonate pipe of 0.05m diameter and superficial air and water velocities up to 8.97 and 0.0778 m/s respectively. A non-intrusive video imaging technique was applied to capture the waves. For image analysis, a frame by frame direct overlapping method was used to detect for pulsating flow and a pixel shifting method based on the detection of minimum values in the overlap function was used to determine wave velocity and wavelength. Under superficial gas velocity of less than 4.44 m/s, the results suggest a regular pulsating outflow produced by the elbow. At higher gas velocities, more random pulsation was found and the emergence of localized interfacial waves was detected. Wave velocities measured by this technique were found to produce satisfactory agreement with direct measurements.

  7. Tunable diode laser absorption sensor for temperature and velocity measurements of O2 in air flows

    Science.gov (United States)

    Philippe, L. C.; Hanson, R. K.

    1991-01-01

    A fast and nonintrusive velocity and temperature diagnostic based on oxygen absorption is presented. The system uses a GaAlAs tunable diode laser, ramped and modulated in wavelength at high frequency. Detection is performed at twice the modulating frequency, leading to second harmonic absorption lineshapes. Velocity is inferred from the wavelength shift of the absorption line center due to the Doppler effect. Temperature is determined by comparing experimental and calculated lineshapes. Capabilities of the technique for studies of transient high-speed flows are demonstrated in shock tube experiments. Good agreement is obtained with predicted temperatures and velocities when pressure-induced shifts are accounted for.

  8. Instrument for long-path spectral extinction measurements in air: application to sizing of airborne particles

    International Nuclear Information System (INIS)

    Paganini, Enrico; Trespidi, Franco; Ferri, Fabio

    2001-01-01

    A novel instrument that is capable of taking spectral extinction measurements over long optical paths (approximately 1-100 m) in the UV, visible, and IR ranges is described. The instrument is fully automated, and the extinction spectrum is acquired in almost real time (approximately 5-10 s) with a resolution of ∼3 nm. Its sensitivity and accuracy were estimated by tests carried out in a clean room that showed that, for optical paths between 50 and 100 m, the extinction coefficient can be detected at levels of ∼10 -5 m -1 . Tests carried out on calibrated latex particles showed that, when it was combined with an appropriate inversion method, the technique could be profitably applied to characterize airborne particulate distributions. By carrying out measurements over optical paths of ∼100 m, the instrument is also capable of detecting extinction coefficients that are due to aerosol concentrations well below the limits imposed by the European Economic Community for atmospheric pollution (150 μg/m3). Scaled over optical paths of ∼10 m, the limit imposed for particle emissions from industrial plants (10 mg/m3) can also be detected sensitively

  9. Measurement of radon progeny concentrations in air by alpha-particle spectrometey

    International Nuclear Information System (INIS)

    Kerr, G.D.

    1975-07-01

    A technique is presented for measuring air concentrations of the short-lived progeny of radon-222 by the use of alpha spectrometry. In this technique, the concentration of RaA, RaB, and RaC are calculated from one integral count of the RaA and two integral counts of the RaC' alpha-particle activity collected on a filter with an air sampling device. The influence of air sampling and counting intervals of time on the accuracy of the calculated concentrations is discussed in the report. A computer program is presented for use with this technique. It is written in the BASIC language. The program will calculate the air concentrations of RaA, RaB, and RaC, and will estimate the accuracy in these calculated concentrations. (U.S.)

  10. Measurements of diurnal concentration variations of gaseous HCl in air in the sub-nanogram range

    Energy Technology Data Exchange (ETDEWEB)

    Matusca, P.; Schwarz, B.; Baechmann, K.

    1984-01-01

    A diffusion sampling method, which allows a filterless dynamic gas-aerosol separation of HCl, has been developed. By gas-phase reaction with 7-oxabicyclo(4.1.0)heptane, HCl is converted into 2-chlorocyclohexanol and through the use of an electrolytic conductivity detector, the product is analyzed by GC-separation. A minimum HCl concentration of 40 pptv has been detected, and the gas has been found in rural areas at concentrations ranging between approximately 0.1 and 1.4 ng/l at STP, and in urban areas at concentrations of approximately 0.2 and 3.0 ng/l at STP. Consideration is also given to diurnal and spatial variations, and climate influence. The center of Darmstadt, a forest in the southeast of Darmstadt, and the Rhein-Main-Airport area of Frankfurt are the three areas where HCl measurements were made. 13 references.

  11. Arduino-based control system for measuring ammonia in air using conditionally-deployed diffusive samplers

    Science.gov (United States)

    Ham, J. M.; Williams, C.; Shonkwiler, K. B.

    2012-12-01

    Arduino microcontrollers, wireless modules, and other low-cost hardware were used to develop a new type of air sampler for monitoring ammonia at strong areal sources like dairies, cattle feedlots, and waste treatment facilities. Ammonia was sampled at multiple locations on the periphery of an operation using Radiello diffusive passive samplers (Cod. RAD168- and RAD1201-Sigma-Aldrich). However, the samplers were not continuously exposed to the air. Instead, each sampling station included two diffusive samplers housed in specialized tubes that sealed the cartridges from the atmosphere. If a user-defined set of wind and weather conditions were met, the Radiellos were deployed into the air using a micro linear actuator. Each station was solar-powered and controlled by Arduinos that were linked to a central weather station using Xbee wireless modules (Digi International Inc.). The Arduinos also measured the total time of exposure using hall-effect sensors to verify the position of the cartridge (i.e., deployed or retracted). The decision to expose or retract the samplers was made every five minutes based on wind direction, wind speed, and time of day. Typically, the diffusive samplers were replaced with fresh cartridges every two weeks and the used samplers were analyzed in the laboratory using ion chromatography. Initial studies were conducted at a commercial dairy in northern Colorado. Ammonia emissions along the Front Range of Colorado can be transported into the mountains where atmospheric deposition of nitrogen can impact alpine ecosystems. Therefore, low-cost air quality monitoring equipment is needed that can be widely deployed in the region. Initial work at the dairy showed that ammonia concentrations ranged between 600 to 1200 ppb during the summer; the highest concentrations were downwind of a large anaerobic lagoon. Time-averaged ammonia concentrations were also used to approximate emissions using inverse dispersion models. This methodology provides a

  12. Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinquan [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Sun, Xiaodong, E-mail: sun.200@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, 201 W. 19th Ave., Columbus, OH 43210 (United States); Liu, Yang [Nuclear Engineering Program, Department of Mechanical Engineering, Virginia Tech, 635 Prices Fork Road, Blacksburg, VA 24061 (United States)

    2016-12-15

    This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

  13. Liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions

    International Nuclear Information System (INIS)

    Zhou, Xinquan; Sun, Xiaodong; Liu, Yang

    2016-01-01

    This paper focuses on liquid-phase turbulence measurements in air-water two-phase flows over a wide range of void fractions and flow regimes, spanning from bubbly, cap-bubbly, slug, to churn-turbulent flows. The measurements have been conducted in two test facilities, the first one with a circular test section and the second one with a rectangular test section. A particle image velocimetry-planar laser-induced fluorescence (PIV-PLIF) system was used to acquire local liquid-phase turbulence information, including the time-averaged velocity and velocity fluctuations in the streamwise and spanwise directions, and Reynolds stress. An optical phase separation method using fluorescent particles and optical filtration technique was adopted to extract the liquid-phase velocity information. An image pre-processing scheme was imposed on the raw PIV images acquired to remove noise due to the presence of bubble residuals and optically distorted particles in the raw PIV images. Four-sensor conductivity probes and high-speed images were also used to acquire the gas-phase information, which was aimed to understand the flow interfacial structure. The highest area-averaged void fraction covered in the measurements for the circular and rectangular test sections was about 40%.

  14. comparative measurement o river for small hydro tive measurement ...

    African Journals Online (AJOL)

    eobe

    nd a stop clock. Ten different m. Ten different m. Ten different measurements were carried out easurements were carried out that the average volumetric flow rate .... or revolving cups connected to the end. The propeller is free to rotate and the speed of the rotation is related to the river velocity. Simple mechanical counters.

  15. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement; Medida de los descendientes del radon en aire por Espectrometria Alfa

    Energy Technology Data Exchange (ETDEWEB)

    Acena, M. L.; Crespo, M. T.

    1989-07-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs.

  16. Comparative study of the expansion dynamics of laser-driven plasma and shock wave in in-air and underwater ablation regimes

    Science.gov (United States)

    Nguyen, Thao T. P.; Tanabe, Rie; Ito, Yoshiro

    2018-03-01

    We compared the expansion characteristics of the plasma plumes and shock waves generated in laser-induced shock process between the two ablation regimes: in air and under water. The observation was made from the initial moment when the laser pulse hit the target until 1.5 μs. The shock processes were driven by focusing a single laser pulse (1064 nm, FWHM = 13 ns) onto the surface of epoxy-resin blocks using a 40-mm focal length lens. The estimated laser intensity at the target plane is approximate to 9 ×109Wcm-2 . We used the fast-imaging technique to observe the expansion of the plasma plume and a custom-designed time-resolved photoelasticity imaging technique to observe the propagation of shock waves with the time resolution of nanoseconds. We found that at the same intensity of the laser beam, the plasma expansion during the laser pulse follows different mechanisms: the plasma plume that grows in air follows a radiation-wave model while a detonation-wave model can explain the expansion of the plasma plume induced in water. The ideal blast wave theory can be used to predict the decay of the shock wave in air but is not appropriate to describe the decay of the shock wave induced under water.

  17. Nonlinear reflection of a spherically divergent N-wave from a plane surface: Optical interferometry measurements in air

    Energy Technology Data Exchange (ETDEWEB)

    Karzova, M., E-mail: masha@acs366.phys.msu.ru [Laboratoire de Mécanique des Fluides et d’Acoustique, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully (France); Physics Faculty, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Yuldashev, P.; Khokhlova, V. [Physics Faculty, Moscow State University, Leninskie Gory, 119991 Moscow (Russian Federation); Ollivier, S.; Blanc-Benon, Ph. [Laboratoire de Mécanique des Fluides et d’Acoustique, Ecole Centrale de Lyon, 36 Avenue Guy de Collongue, 69134 Ecully (France)

    2015-10-28

    Mach stem is a well-known structure typically observed in the process of strong (acoustic Mach numbers greater than 0.4) step-shock waves reflection from a rigid boundary. However, this phenomenon has been much less studied for weak shocks in nonlinear acoustic fields where Mach numbers are in the range from 0.001 to 0.01 and pressure waveforms have more complicated waveforms than step shocks. The goal of this work was to demonstrate experimentally how nonlinear reflection occurs in air for very weak spherically divergent acoustic spark-generated pulses resembling an N-wave. Measurements of reflection patterns were performed using a Mach-Zehnder interferometer. A thin laser beam with sub-millimeter cross-section was used to obtain the time resolution of 0.4 µs, which is 6 times higher than the time resolution of the condenser microphones. Pressure waveforms were reconstructed using the inverse Abel transform applied to the phase of the signal measured by the interferometer. The Mach stem formation was observed experimentally as a result of collision of the incident and reflected shock pulses. It was shown that irregular reflection of the pulse occurred in a dynamic way and the length of the Mach stem increased linearly while the pulse propagated along the surface. Since the front shock of the spark-generated pulse was steeper than the rear shock, irregular type of reflection was observed only for the front shock of the pulse while the rear shock reflection occurred in a regular regime.

  18. A comparative study on total reflection X-ray fluorescence determination of low atomic number elements in air, helium and vacuum atmospheres using different excitation sources

    Science.gov (United States)

    Misra, N. L.; Kanrar, Buddhadev; Aggarwal, S. K.; Wobrauschek, Peter; Rauwolf, M.; Streli, Christina

    2014-09-01

    A comparison of trace element determinations of low atomic number (Z) elements Na, Mg, Al, P, K and Ca in air, helium and vacuum atmospheres using W Lβ1, Mo Kα and Cr Kα excitations has been made. For Mo Kα and W Lβ1 excitations a Si (Li) detector with beryllium window was used and measurements were performed in air and helium atmospheres. For Cr Kα excitation, a Si (Li) detector with an ultra thin polymer window (UTW) was used and measurements were made in vacuum and air atmospheres. The sensitivities of the elemental X-ray lines were determined using TXRF spectra of standard solutions and processing them by IAEA QXAS program. The elemental concentrations of the elements in other solutions were determined using their TXRF spectra and pre-determined sensitivity values. The study suggests that, using the above experimental set up, Mo Kα excitation is not suited for trace determination of low atomic number element. Excitation by WLβ1 and helium atmosphere, the spectrometer can be used for the determination of elements with Z = 15 (P) and above with fairly good detection limits whereas Cr Kα excitation with ultra thin polymer window and vacuum atmosphere is good for the elements having Z = 11 (Na) and above. The detection limits using this set up vary from 7048 pg for Na to 83 pg for Ti.

  19. Comparative investigations of the spontaneous and stimulated emissions from nitrogen molecules in air with femtosecond laser excitation pulses

    International Nuclear Information System (INIS)

    Li, Ziting; Wang, Zhanshan; Chu, Wei; Zeng, Bin; Yao, Jinping; Li, Guihua; Xie, Hongqiang; Cheng, Ya

    2016-01-01

    We report on experimental investigations on the spontaneous and stimulated emissions from excited nitrogen molecules generated in both linearly and circularly polarized intense laser fields. The spontaneous emission is measured from the side direction of the laser-induced filament whereas the stimulated emission generated by seed amplification is measured in the forward direction of the laser propagation. The comparison between the signal intensities of the spontaneous fluorescence emission and the seed-amplified stimulated emission provides an insight into the population inversion generated in nitrogen molecules with circularly polarized femtosecond laser pulses. (paper)

  20. Virtual patient 3D dose reconstruction using in air EPID measurements and a back-projection algorithm for IMRT and VMAT treatments.

    Science.gov (United States)

    Olaciregui-Ruiz, Igor; Rozendaal, Roel; van Oers, René F M; Mijnheer, Ben; Mans, Anton

    2017-05-01

    At our institute, a transit back-projection algorithm is used clinically to reconstruct in vivo patient and in phantom 3D dose distributions using EPID measurements behind a patient or a polystyrene slab phantom, respectively. In this study, an extension to this algorithm is presented whereby in air EPID measurements are used in combination with CT data to reconstruct 'virtual' 3D dose distributions. By combining virtual and in vivo patient verification data for the same treatment, patient-related errors can be separated from machine, planning and model errors. The virtual back-projection algorithm is described and verified against the transit algorithm with measurements made behind a slab phantom, against dose measurements made with an ionization chamber and with the OCTAVIUS 4D system, as well as against TPS patient data. Virtual and in vivo patient dose verification results are also compared. Virtual dose reconstructions agree within 1% with ionization chamber measurements. The average γ-pass rate values (3% global dose/3mm) in the 3D dose comparison with the OCTAVIUS 4D system and the TPS patient data are 98.5±1.9%(1SD) and 97.1±2.9%(1SD), respectively. For virtual patient dose reconstructions, the differences with the TPS in median dose to the PTV remain within 4%. Virtual patient dose reconstruction makes pre-treatment verification based on deviations of DVH parameters feasible and eliminates the need for phantom positioning and re-planning. Virtual patient dose reconstructions have additional value in the inspection of in vivo deviations, particularly in situations where CBCT data is not available (or not conclusive). Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  1. Long open-path measurements of greenhouse gases in air using near-infrared Fourier transform spectroscopy

    Directory of Open Access Journals (Sweden)

    D. W. T. Griffith

    2018-03-01

    Full Text Available In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high-resolution atmospheric models of composition and meteorology with resolutions of the order of a kilometre. Open-path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open-path Fourier transform spectroscopy (FTS in the mid-infrared region, and differential optical absorption spectroscopy (DOAS in the UV and visible, have been used for many years for open-path spectroscopic measurements of selected species in both clean air and in polluted environments. Near infrared instrumentation allows measurements over longer paths than mid-infrared FTS for species such as greenhouse gases which are not easily accessible to DOAS.In this pilot study we present the first open-path near-infrared (4000–10 000 cm−1, 1.0–2.5 µm FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open-path FTS system, the analysis of the collected spectra, several measures of precision and accuracy of the measurements, and the results a four-month trial measurement period in July–November 2014. The open-path measurements are compared to calibrated in situ measurements made at one end of the open path. We observe significant differences of the order of a few ppm for CO2 and a few tens of ppb for CH4 between the open-path and point measurements which are 2 to 4 times the measurement repeatability, but we cannot unequivocally assign the differences to specific local sources or sinks. We conclude that open-path FTS may provide a valuable new tool for investigations of

  2. Long open-path measurements of greenhouse gases in air using near-infrared Fourier transform spectroscopy

    Science.gov (United States)

    Griffith, David W. T.; Pöhler, Denis; Schmitt, Stefan; Hammer, Samuel; Vardag, Sanam N.; Platt, Ulrich

    2018-03-01

    In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high-resolution atmospheric models of composition and meteorology with resolutions of the order of a kilometre. Open-path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open-path Fourier transform spectroscopy (FTS) in the mid-infrared region, and differential optical absorption spectroscopy (DOAS) in the UV and visible, have been used for many years for open-path spectroscopic measurements of selected species in both clean air and in polluted environments. Near infrared instrumentation allows measurements over longer paths than mid-infrared FTS for species such as greenhouse gases which are not easily accessible to DOAS.In this pilot study we present the first open-path near-infrared (4000-10 000 cm-1, 1.0-2.5 µm) FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open-path FTS system, the analysis of the collected spectra, several measures of precision and accuracy of the measurements, and the results a four-month trial measurement period in July-November 2014. The open-path measurements are compared to calibrated in situ measurements made at one end of the open path. We observe significant differences of the order of a few ppm for CO2 and a few tens of ppb for CH4 between the open-path and point measurements which are 2 to 4 times the measurement repeatability, but we cannot unequivocally assign the differences to specific local sources or sinks. We conclude that open-path FTS may provide a valuable new tool for investigations of atmospheric trace gas composition in

  3. A comparative study of foot measurements using Receiver ...

    African Journals Online (AJOL)

    The objective of this research was to assess the reliability of the foot measurements by comparing the male and female foot measurements, to know if there is correlation between the male and female foot measurements using the standard set by Landis and Koch (1977), and also to identity the true positive rate and false ...

  4. A comparative study on total reflection X-ray fluorescence determination of low atomic number elements in air, helium and vacuum atmospheres using different excitation sources

    Energy Technology Data Exchange (ETDEWEB)

    Misra, N.L., E-mail: nlmisra@barc.gov.in [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kanrar, Buddhadev; Aggarwal, S.K. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Wobrauschek, Peter; Rauwolf, M.; Streli, Christina [TU Wien, Atominstitut, Stadionallee 2, 1020 Vienna (Austria)

    2014-09-01

    A comparison of trace element determinations of low atomic number (Z) elements Na, Mg, Al, P, K and Ca in air, helium and vacuum atmospheres using W Lβ{sub 1}, Mo Kα and Cr Kα excitations has been made. For Mo Kα and W Lβ{sub 1} excitations a Si (Li) detector with beryllium window was used and measurements were performed in air and helium atmospheres. For Cr Kα excitation, a Si (Li) detector with an ultra thin polymer window (UTW) was used and measurements were made in vacuum and air atmospheres. The sensitivities of the elemental X-ray lines were determined using TXRF spectra of standard solutions and processing them by IAEA QXAS program. The elemental concentrations of the elements in other solutions were determined using their TXRF spectra and pre-determined sensitivity values. The study suggests that, using the above experimental set up, Mo Kα excitation is not suited for trace determination of low atomic number element. Excitation by WLβ1 and helium atmosphere, the spectrometer can be used for the determination of elements with Z = 15 (P) and above with fairly good detection limits whereas Cr Kα excitation with ultra thin polymer window and vacuum atmosphere is good for the elements having Z = 11 (Na) and above. The detection limits using this set up vary from 7048 pg for Na to 83 pg for Ti. - Highlights: • TXRF conditions are optimized for low atomic number (Z) element determinations. • Mo Kα with Be window detector can be used for elements with Z ≥ 20 (K). • W Lβ{sub 1} with Be window detector can be used for elements with Z ≥ 15 (P). • Cr Kα, UTW detector and vacuum atmosphere are suitable for elements with Z ≥ 11 (Na). • For the elements with Z ≥ 11 (Na), a separate study is needed.

  5. A comparative study of performance measurement standards of railway operator

    Directory of Open Access Journals (Sweden)

    Pongjirawut Siripong

    2017-01-01

    Full Text Available The European standard (EN 13816, is one of the widely accepted standards for measuring the quality of public passenger transport (PPT service. EN 13816 indicates 8 measurement criteria, 29 sub-criteria and 193 Key Performance Indicators (KPIs to be used to measure the performance of railway operators. Nowadays, there are other addition criteria beyond EN13816, developed by various organisations. This research firstly aims to explore the service performance measurement of railway operators used by actual railway operators at international level and in Thailand. After an intensive review of performance measurement standards, 9 standards are compiled and compared in terms of criteria, sub-criteria and KPIs using a cluster analysis methodology. The result found additional performance measurement aspects at 2 sub-criteria and 91 KPIs in addition to EN 13816. This research summarized and compared different performance measurement standards to measure service quality of metro rail line.

  6. Comparing 3D foot scanning with conventional measurement methods.

    Science.gov (United States)

    Lee, Yu-Chi; Lin, Gloria; Wang, Mao-Jiun J

    2014-01-01

    Foot dimension information on different user groups is important for footwear design and clinical applications. Foot dimension data collected using different measurement methods presents accuracy problems. This study compared the precision and accuracy of the 3D foot scanning method with conventional foot dimension measurement methods including the digital caliper, ink footprint and digital footprint. Six commonly used foot dimensions, i.e. foot length, ball of foot length, outside ball of foot length, foot breadth diagonal, foot breadth horizontal and heel breadth were measured from 130 males and females using four foot measurement methods. Two-way ANOVA was performed to evaluate the sex and method effect on the measured foot dimensions. In addition, the mean absolute difference values and intra-class correlation coefficients (ICCs) were used for precision and accuracy evaluation. The results were also compared with the ISO 20685 criteria. The participant's sex and the measurement method were found (p < 0.05) to exert significant effects on the measured six foot dimensions. The precision of the 3D scanning measurement method with mean absolute difference values between 0.73 to 1.50 mm showed the best performance among the four measurement methods. The 3D scanning measurements showed better measurement accuracy performance than the other methods (mean absolute difference was 0.6 to 4.3 mm), except for measuring outside ball of foot length and foot breadth horizontal. The ICCs for all six foot dimension measurements among the four measurement methods were within the 0.61 to 0.98 range. Overall, the 3D foot scanner is recommended for collecting foot anthropometric data because it has relatively higher precision, accuracy and robustness. This finding suggests that when comparing foot anthropometric data among different references, it is important to consider the differences caused by the different measurement methods.

  7. Measuring populism: comparing two methods of content analysis

    NARCIS (Netherlands)

    Rooduijn, M.; Pauwels, T.

    2011-01-01

    The measurement of populism - particularly over time and space - has received only scarce attention. In this research note two different ways to measure populism are compared: a classical content analysis and a computer-based content analysis. An analysis of political parties in the United Kingdom,

  8. Ultrasound measurements of testicular volume: Comparing the three ...

    African Journals Online (AJOL)

    Objective: To determine the accuracy of various ultrasound formulas for measuring the testicular volume in humans by comparing the resultant measurements with the actual testicular volume. Subjects and methods: The testicular volume of 121 testes from 62 patients with prostate cancer (mean age 72.7 ± 9.4) was ...

  9. A Framework for Comparative Assessments of Energy Efficiency Policy Measures

    Energy Technology Data Exchange (ETDEWEB)

    Blum, Helcio; Atkinson, Barbara; Lekov, Alex

    2011-05-24

    When policy makers propose new policies, there is a need to assess the costs and benefits of the proposed policy measures, to compare them to existing and alternative policies, and to rank them according to their effectiveness. In the case of equipment energy efficiency regulations, comparing the effects of a range of alternative policy measures requires evaluating their effects on consumers’ budgets, on national energy consumption and economics, and on the environment. Such an approach should be able to represent in a single framework the particularities of each policy measure and provide comparable results. This report presents an integrated methodological framework to assess prospectively the energy, economic, and environmental impacts of energy efficiency policy measures. The framework builds on the premise that the comparative assessment of energy efficiency policy measures should (a) rely on a common set of primary data and parameters, (b) follow a single functional approach to estimate the energy, economic, and emissions savings resulting from each assessed measure, and (c) present results through a set of comparable indicators. This framework elaborates on models that the U.S. Department of Energy (DOE) has used in support of its rulemakings on mandatory energy efficiency standards. In addition to a rigorous analysis of the impacts of mandatory standards, DOE compares the projected results of alternative policy measures to those projected to be achieved by the standards. The framework extends such an approach to provide a broad, generic methodology, with no geographic or sectoral limitations, that is useful for evaluating any type of equipment energy efficiency market intervention. The report concludes with a demonstration of how to use the framework to compare the impacts estimated for twelve policy measures focusing on increasing the energy efficiency of gas furnaces in the United States.

  10. Comparative study of bedside and laboratory measurements of hemoglobin.

    Science.gov (United States)

    Krenzischek, D A; Tanseco, F V

    1996-11-01

    The purpose of this study was to examine the effects of variations in technique on measurements of hemoglobin level done at the bedside and to compare these results with laboratory measurements of hemoglobin. In accordance with hospital policy, procedure, and protocol, various techniques were used to obtain samples of capillary and venous blood and of blood from arterial and central venous catheters. Levels of hemoglobin were measured at the bedside and in the laboratory, and the results were compared. The Johns Hopkins Hospital adult postanesthesia care unit. A total of 187 blood samples were obtained from 62 adults who had undergone general surgery. Group I comprised 20 subjects with capillary and venous blood samples. Group II comprised 21 subjects with arterial blood samples. Group III comprised 21 subjects with central venous blood samples. The results showed that the amount of blood to be discarded before obtaining samples of arterial and central venous blood need not be any larger than double the dead space of the catheter, and that shaking the blood sample for 10 seconds was sufficient to mix the sample before measurement of hemoglobin levels. Results of bedside and laboratory measurements of hemoglobin level were comparable. Bedside measurement of hemoglobin increases efficiency in patient care, decreases risk of blood-transmitted infection for staff, and decreases cost to the patient. However, the persons who perform the assay must be responsible in adhering to the standard of practice to minimize errors in the measurements.

  11. Measuring and comparing normal ear protrusion using computerized tomography

    International Nuclear Information System (INIS)

    Otsuka, Yasushi; Hosaka, Yoshiaki; Kiuchi, Tatsuya

    1998-01-01

    The normal external ears of 128 Japanese individuals (64 men and 64 women) were measured using the angle-measuring function of analytic software for computerized tomography (CT). The initial baseline for measurement was the orbitomeatal line (OM line); second measurements were taken 1 cm above the baseline (OM+1 cm), and third measurements 2 cm above the baseline (OM+2 cm). The sample was divided into two groups by sex (64 men and 64 women) and into three groups by age (20-39, 40-59, and 60+), and protrusion measurements for the three sections were compared by both sex and age. The results showed that males have larger auricular values (auricular concha cranial angle, auricular concha scaphoid angle, auricular cranial angle) than do females. In terms of age, the results showed that the auricular concha cranial angle becomes larger with increasing age, while the auricular concha scaphoid angle and auricular cranial angle become smaller with age. (author)

  12. Measurement of W values for protons, {sup 4}He- and {sup 12}C ions in air, argon and nitrogen; Messung von W-Werten fuer Protonen, {sup 4}He- und {sup 12}C-Ionen in Luft, Argon und Stickstoff

    Energy Technology Data Exchange (ETDEWEB)

    Beck, Jeannine

    2012-06-27

    In particle therapy for cancer the dosimetry of charged-particle radiation is usually performed by measuring the ionization produced in air-filled ionization chambers. The conversion of the reading of ionization chambers into absorbed dose requires W-values, which are defined as the average energy needed to produce an ion pair. Because of the increasing importance of ion therapy and the lack of experimental data for heavy charged particles in air, new measurements of W-values are being carried out at the Physikalisch-Technische Bundesanstalt Braunschweig (PTB) and the Helmholtzzentrum fuer Schwerionenforschung GmbH Darmstadt (GSI). Existing measurements for protons in air indicate an uncertainty of ±4 %. The main goals of the present work are to achieve consistent measurements for protons, helium and carbon ions in air, argon and nitrogen in the energy region of 1 MeV/u up to 7 MeV/u and to reduce the uncertainties. A low rate of 200 incoming ions per second is produced by scattering the primary beam from the accelerators off a thin gold foil at the center of a scattering chamber. At 45 an either side relative to the beam direction, the scattered ions are detected in a semiconductor detector and stopped in a gas-filled ionization chamber. In this way, the number and the energy of the particles entering the active volume of the ionization chamber can be determined using two independent methods. The number of ion pairs produced in the gas volume is determined from the simultaneous measurement of the ionization current collected at the lower electrode of the chamber using a calibrated electrometer. The W-value is calculated from the ionization current, the number and the energy of particles. Furthermore, several corrections like recombination effects, background from beam induced γ-radiation, measurement of the beam stability and gas cleaning are applied and will be discussed in this thesis. The measured W-values tend to be smaller than existing data and Show an

  13. A comparative study of physical performance measures in Parkinson's disease.

    Science.gov (United States)

    Tanji, Haruko; Gruber-Baldini, Ann L; Anderson, Karen E; Pretzer-Aboff, Ingrid; Reich, Stephen G; Fishman, Paul S; Weiner, William J; Shulman, Lisa M

    2008-10-15

    The objective of this study is to compare physical performance measures for their ability to discriminate between levels of disability and disease severity in Parkinson's disease (PD). Disability in PD is commonly assessed by patient self-report, which may be limited by patient insight. Seventy-nine patients with PD were tested with seven performance measures: Physical Performance Test (PPT), modified Physical Performance Test (mPPT), Short Physical Performance Battery (SPPB), Performance Test of Activities of Daily Living (PADL), Berg Balance Scale (BBS), Timed Up and Go (TUG), and Functional Reach (FR). These measures were compared with patient-reported disability on the Older Americans Resource and Services Disability subscale (OARS) and disease severity on the Unified Parkinson's Disease Rating Scale (UPDRS). The performance measures were more sensitive to levels of disease severity than disability. Four measures discriminated across quartiles of disability (PPT, mPPT, BBS, TUG: P mPPT, BBS, TUG, FR: P < 0.01; SPPB, PADL: P < 0.05). However, no measure consistently discriminated between subgroups with a range of early and advanced disease severity. The seven physical performance measures showed different profiles of strengths and weaknesses in assessing disability and disease severity. The results of this study will facilitate choosing performance measures for clinical care and clinical trials in PD. (c) 2008 Movement Disorder Society.

  14. Comparing predicted estrogen concentrations with measurements in US waters

    International Nuclear Information System (INIS)

    Kostich, Mitch; Flick, Robert; Martinson, John

    2013-01-01

    The range of exposure rates to the steroidal estrogens estrone (E1), beta-estradiol (E2), estriol (E3), and ethinyl estradiol (EE2) in the aquatic environment was investigated by modeling estrogen introduction via municipal wastewater from sewage plants across the US. Model predictions were compared to published measured concentrations. Predictions were congruent with most of the measurements, but a few measurements of E2 and EE2 exceed those that would be expected from the model, despite very conservative model assumptions of no degradation or in-stream dilution. Although some extreme measurements for EE2 may reflect analytical artifacts, remaining data suggest concentrations of E2 and EE2 may reach twice the 99th percentile predicted from the model. The model and bulk of the measurement data both suggest that cumulative exposure rates to humans are consistently low relative to effect levels, but also suggest that fish exposures to E1, E2, and EE2 sometimes substantially exceed chronic no-effect levels. -- Highlights: •Conservatively modeled steroidal estrogen concentrations in ambient water. •Found reasonable agreement between model and published measurements. •Model and measurements agree that risks to humans are remote. •Model and measurements agree significant questions remain about risk to fish. •Need better understanding of temporal variations and their impact on fish. -- Our model and published measurements for estrogens suggest aquatic exposure rates for humans are below potential effect levels, but fish exposure sometimes exceeds published no-effect levels

  15. Three scales of aerial photography compared for making stand measurements

    Science.gov (United States)

    Earl J. Rogers; Gene Avery; Roy A. Chapman

    1959-01-01

    Three scales of aerial photography were tested in an attempt to determine the best scale to use in forest surveying. This was done by comparing photo measurements of average tree height, average crown diameter, and crown-closure percent. These stand variables were selected for testing because of their applicability in making aerial estimates of timber volume.

  16. Comparative study of growth and linear body measurements in Anak ...

    African Journals Online (AJOL)

    The study was designed to compare the performance of two different breeds of broilers (Anak and Hubbard) using body weight and body linear measurements. Data on a total of 200 (100 each) Anak and Hubbard broiler breeds were collected weekly and the experiment lasted for 8 weeks. The parameters investigated ...

  17. Where is the human waist? Definitions, manual compared toscanner measurements.

    Science.gov (United States)

    Veitch, Daisy

    2012-01-01

    Where exactly is the human waist? How do definitions work for women who deviate from the conventional body shape? Does the measuring instrument matter? Waist is conventionally understood to be a measurable zone within the abdominal region of the torso, a zone of considerable importance. There needs to be a good consistent waist definition, one accurate and valid for everyone. Incorrect definition and measurement will result in technical errors, commercial wastage and customer dissatisfaction. This paper investigates the waist's location and size from the point of view of garment construction for 90 adult women scanned and manually measured in a breast reduction study at Flinders Medical Center, South Australia. There are differing definitions of the location of the human waist as well as different measuring instruments. This study compares:• Two definitions:• ISO 8559, 2.1.11 and • CAESAR, Waist Circumference Preferred.• Two different instruments:• the traditional tape measure, and • software-extracted computer-aided anthropometry (CAA). Substantial discrepancies between the results from these two locations-definitions were found. The choice of instrument used seriously affects the measurement obtained. This study demonstrates three things:• waist is not horizontal for a significant sub group of the population,• CAA extracted waist measurements are not accurate (same as real values) or valid (measures the characteristic) for a sub group, and • manually measured CAESAR Preferred Waist accurately and validly measured all individuals studied. There is a clear need to modify ISO waist definition for garment construction to include the full range of anatomical variation encountered amongst women.

  18. Comparative Analysis of Methods of Measuring Company's Intellectual Capital

    Directory of Open Access Journals (Sweden)

    Przemysław Dominiak

    2013-01-01

    Full Text Available Intellectual capital is, in general, considered to be a component of a company's market value, which is not always reflected in its financial statements. The authors analyzed 21 of the most common methods of measuring company's intellectual capital. Detailed analysis of these methods made it possible to identify a set of 7 basic criteria that clearly distinguish them. The paper presents a comparative matrix of methods of measuring intellectual capital in terms of all the considered criteria. It is shown that, among the best known methods of measuring intellectual capital, there is no so-called "standard measure", i.e. one which fulfils all the criteria at the same time. (original abstract

  19. Comparing Measures of Late HIV Diagnosis in Washington State

    Directory of Open Access Journals (Sweden)

    Laura Saganic

    2012-01-01

    Full Text Available As more US HIV surveillance programs routinely use late HIV diagnosis to monitor and characterize HIV testing patterns, there is an increasing need to standardize how late HIV diagnosis is measured. In this study, we compared two measures of late HIV diagnosis, one based on time between HIV and AIDS, the other based on initial CD4+ results. Using data from Washington's HIV/AIDS Reporting System, we used multivariate logistic regression to identify predictors of late HIV diagnosis. We also conducted tests for trend to determine whether the proportion of cases diagnosed late has changed over time. Both measures lead us to similar conclusions about late HIV diagnosis, suggesting that being male, older, foreign-born, or heterosexual increase the likelihood of late HIV diagnosis. Our findings reaffirm the validity of a time-based definition of late HIV diagnosis, while at the same time demonstrating the potential value of a lab-based measure.

  20. Evidence of bias in air-water Henry's law constants for semivolatile organic compounds measured by inert gas stripping.

    Science.gov (United States)

    Shunthirasingham, Chubashini; Lei, Ying Duan; Wania, Frank

    2007-06-01

    Accurate knowledge of the air-water Henry's law constant (H) is crucial for understanding an organic compound's environmental behavior. The inert gas stripping (IGS) method, widely used to measure H of semivolatile organic compounds (SOCs), may yield erroneously high values for compounds with a high water surface adsorption coefficient, K(IA), because chemical adsorbed to the bubble surface may be transferred to the head space upon bursting at the top of the stripping column. Experiments with alkanols of variable chain length identified a K(IA) threshold of approximately 10(-3) m, above which IGS is susceptible to this artifact. Most SOCs are predicted to have K(IA) values well above that threshold. IGS-determined H-values for chemicals belonging to various groups of SOCs were evaluated by comparison with H-values either calculated from reliable vapor pressure and solubility data or derived from data compilations that achieve thermodynamic consistency through optimized adjustment of measured physical-chemical property data. The investigated deviations were found to be generally consistent with what would be expected from a surface adsorption artifact. Namely, the apparent bias in IGS-determined H-values, if it occurs, (1) is positive, (2) increases with increasing size of an SOC, and (3) increases with decreasing temperature. It generally is also of a magnitude predicted using estimated K(IA) values. However, different studies display different K(IA) threshold values, beyond which the artifact becomes notable, and some studies appear to succeed in avoiding the artifact altogether. Whereas the use of aerosol traps cannot explain the absence of a surface adsorption artifact, it may be related to higher flow rates used by some investigators. For large compounds or those with more than one functional group, the predicted deviation is too large when compared to observations, suggesting that the estimated K(IA) values for those compounds are too high. A full quantitative

  1. Problems in air traffic management. VII., Job training performance of air traffic control specialists - measurement, structure, and prediction.

    Science.gov (United States)

    1965-07-01

    A statistical study of training- and job-performance measures of several hundred Air Traffic Control Specialists (ATCS) representing Enroute, Terminal, and Flight Service Station specialties revealed that training-performance measures reflected: : 1....

  2. An Experiment to Measure Range, Range Straggling, Stopping Power, and Energy Straggling of Alpha Particles in Air

    Science.gov (United States)

    Ouseph, P. J.; Mostovych, Andrew

    1978-01-01

    Experiments to measure range, range straggling, stopping power, and energy straggling of alpha particles are discussed in this article. Commercially available equipment with simple modifications is used for these measurements. (Author/GA)

  3. Smile line assessment comparing quantitative measurement and visual estimation.

    Science.gov (United States)

    Van der Geld, Pieter; Oosterveld, Paul; Schols, Jan; Kuijpers-Jagtman, Anne Marie

    2011-02-01

    Esthetic analysis of dynamic functions such as spontaneous smiling is feasible by using digital videography and computer measurement for lip line height and tooth display. Because quantitative measurements are time-consuming, digital videography and semiquantitative (visual) estimation according to a standard categorization are more practical for regular diagnostics. Our objective in this study was to compare 2 semiquantitative methods with quantitative measurements for reliability and agreement. The faces of 122 male participants were individually registered by using digital videography. Spontaneous and posed smiles were captured. On the records, maxillary lip line heights and tooth display were digitally measured on each tooth and also visually estimated according to 3-grade and 4-grade scales. Two raters were involved. An error analysis was performed. Reliability was established with kappa statistics. Interexaminer and intraexaminer reliability values were high, with median kappa values from 0.79 to 0.88. Agreement of the 3-grade scale estimation with quantitative measurement showed higher median kappa values (0.76) than the 4-grade scale estimation (0.66). Differentiating high and gummy smile lines (4-grade scale) resulted in greater inaccuracies. The estimation of a high, average, or low smile line for each tooth showed high reliability close to quantitative measurements. Smile line analysis can be performed reliably with a 3-grade scale (visual) semiquantitative estimation. For a more comprehensive diagnosis, additional measuring is proposed, especially in patients with disproportional gingival display. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  4. Comparing measurement errors for formants in synthetic and natural vowels.

    Science.gov (United States)

    Shadle, Christine H; Nam, Hosung; Whalen, D H

    2016-02-01

    The measurement of formant frequencies of vowels is among the most common measurements in speech studies, but measurements are known to be biased by the particular fundamental frequency (F0) exciting the formants. Approaches to reducing the errors were assessed in two experiments. In the first, synthetic vowels were constructed with five different first formant (F1) values and nine different F0 values; formant bandwidths, and higher formant frequencies, were constant. Input formant values were compared to manual measurements and automatic measures using the linear prediction coding-Burg algorithm, linear prediction closed-phase covariance, the weighted linear prediction-attenuated main excitation (WLP-AME) algorithm [Alku, Pohjalainen, Vainio, Laukkanen, and Story (2013). J. Acoust. Soc. Am. 134(2), 1295-1313], spectra smoothed cepstrally and by averaging repeated discrete Fourier transforms. Formants were also measured manually from pruned reassigned spectrograms (RSs) [Fulop (2011). Speech Spectrum Analysis (Springer, Berlin)]. All but WLP-AME and RS had large errors in the direction of the strongest harmonic; the smallest errors occur with WLP-AME and RS. In the second experiment, these methods were used on vowels in isolated words spoken by four speakers. Results for the natural speech show that F0 bias affects all automatic methods, including WLP-AME; only the formants measured manually from RS appeared to be accurate. In addition, RS coped better with weaker formants and glottal fry.

  5. TU-FG-209-09: Mathematical Estimation and Experimental Measurement of Patient Free-In-Air Skin Entrance Exposure During a Panoramic Dental X-Ray Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Errico, A; Behrman, R; Li, B [Boston University Medical Center, Boston, MA (United States)

    2016-06-15

    Purpose: To develop a simple mathematical model for estimating the patient free-in-air skin entrance exposure (SEE) during a panoramic dental x-ray that does not require the use of a head phantom. This eliminates issues associated with phantom centering and the mounting of a detector on the phantom for routine QC testing. Methods: We used a Sirona Orthophos XG panoramic radiographic unit and a Radcal Accu-Gold system for this study. A solid state detector was attached over the slit of the Orthophos’ sensor with the help of a custom-built jig. A single measurement of the free-in-air exposure at this position was taken over a full panoramic scan. A mathematical model for estimating the SEE was developed based upon this measurement, the system geometry, x-ray field beam width, and x-ray sweep angle. To validate the model, patient geometry was simulated by a 16 cm diameter PMMA CTDI phantom centered at the machine’s isocenter. Measurements taken on the phantom’s surface were made using a solid state detector with lead backing, an ion chamber, and the ion chamber with the phantom wrapped in lead to mitigate backscatter. Measurements were taken near the start position of the tube and at 90 degrees from the start position. Results: Using the solid state detector, the average SEE was 23.5+/−0.02 mR and 55.5+/−0.08 mR at 64 kVp and 73 kVp, respectively. With the lead-wrapping, the measurements from the ion chamber matched those of the solid state detector to within 0.1%. Preliminary results gave the difference between the mathematical model and the phantom measurements to be approximately 5% at both kVps. Conclusion: Reasonable estimates of patient SEE for panoramic dental radiography can be made using a simple mathematical model without the need for a head phantom.

  6. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    Science.gov (United States)

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  7. Comparing GPS, Log, Survey, and Accelerometry to Measure Physical Activity.

    Science.gov (United States)

    James, Peter; Weissman, Jennifer; Wolf, Jean; Mumford, Karen; Contant, Cheryl K; Hwang, Wei-Ting; Taylor, Lynne; Glanz, Karen

    2016-01-01

    We explored how objectively measured global positioning system (GPS) and accelerometer data match with travel logs and questionnaires in predicting trip duration and physical activity (PA). 99 participants wore GPS devices and accelerometers, and recorded all trips in a log for 5 consecutive days. Participants also completed a self-administered questionnaire on PA and travel behaviors. There was good agreement between GPS and log for assessment of trip duration, although log measures overestimated trip duration (concordance correlation coefficient 0.53 [0.47, 0.59]; Bland-Altman estimate 0.76 [0.16, 3.71] comparing GPS to log). Log measures underestimated light PA and overestimated moderate PA compared to accelerometry when greater than zero moderate PA was reported. It is often not feasible to deploy accelerometry or GPS devices in population research because these devices are expensive and require technical expertise and data processing. Questionnaires and logs provide inexpensive tools to assess PA and travel with reasonable concordance with objective measures. However, they have shortcomings in evaluating the presence and amount of light and moderate PA. Future questionnaires and logs should be developed to evaluate sensitivity to light and moderate PA.

  8. Femoral anteversion measured by ultrasound and CT: a comparative study

    International Nuclear Information System (INIS)

    Aamodt, A.; Terjesen, T.; Eine, J.; Kvistad, K.A.

    1995-01-01

    Both computed tomography (CT) and ultrasonography have been used successfully to estimate the femoral anteversion (AV) angle. In this study, AV angles in 20 human adult femurs were determined by ultrasonography and CT and the measurements compared. On CT the real AV angle was measured as the angle between the head-neck centreline and the posterior condylar plane. In addition, the angle between the anterior head-trochanter (HT) tangent and the posterior condylar plane was determined. The latter angle was also measured by ultrasonography using the tilted transducer technique. The mean interobserver variation in the ultrasound measurements was 1.9 . We found ultrasonography to correlate very well with CT, both when comparing with the HT angle (r=0.95) and with the AV angle (r=0.93). The HT angle was on average 4 greater than the AV angle. In this study the accuracy of ultrasonography was ±5 and the method is recommended for screening in patients with rotational disorders of the femur. (orig.)

  9. Motion-Correlated Flow Distortion and Wave-Induced Biases in Air-Sea Flux Measurements From Ships

    Science.gov (United States)

    Prytherch, J.; Yelland, M. J.; Brooks, I. M.; Tupman, D. J.; Pascal, R. W.; Moat, B. I.; Norris, S. J.

    2016-02-01

    Direct measurements of the turbulent air-sea fluxes of momentum, heat, moisture and gases are often made using sensors mounted on ships. Ship-based turbulent wind measurements are corrected for platform motion using well established techniques, but biases at scales associated with wave and platform motion are often still apparent in the flux measurements. It has been uncertain whether this signal is due to time-varying distortion of the air flow over the platform, or to wind-wave interactions impacting the turbulence. Methods for removing such motion-scale biases from scalar measurements have previously been published but their application to momentum flux measurements remains controversial. Here we use eddy covariance momentum flux measurements obtained onboard RRS James Clark Ross as part of the Waves, Aerosol and Gas Exchange Study (WAGES), a programme of near-continuous measurements using the autonomous AutoFlux system (Yelland et al., 2009). Measurements were made in 2013 in locations throughout the North and South Atlantic, the Southern Ocean and the Arctic Ocean, at latitudes ranging from 62°S to 75°N. We show that the measured motion-scale bias has a dependence on the horizontal ship velocity, and that a correction for it reduces the dependence of the measured momentum flux on the orientation of the ship to the wind. We conclude that the bias is due to experimental error, and that time-varying motion-dependent flow distortion is the likely source. Yelland, M., Pascal, R., Taylor, P. and Moat, B.: AutoFlux: an autonomous system for the direct measurement of the air-sea fluxes of CO2, heat and momentum. J. Operation. Oceanogr., 15-23, doi:10.1080/1755876X.2009.11020105, 2009.

  10. Diurnal and seasonal variation in air exchange rates and interzonal airflows measured by active and passive tracer gas in homes

    DEFF Research Database (Denmark)

    Bekö, Gabriel; Gustavsen, Sine; Frederiksen, Marie

    2016-01-01

    Outdoor air delivery to buildings is an important parameter in the assessment of pollutant exposure indoors. Detailed and well controlled measurements of air exchange rates (AER) and interzonal airflows in residential environment are scarce. We measured the outdoor AERs in up to six rooms in five...

  11. Measurements of the Institut fuer Strahlenhygiene of radioiodine in air, precipitation and fresh milk after the Chinese nuclear bomb test of Sept. 17, 1977

    International Nuclear Information System (INIS)

    Riedel, H.; Bretschneider, J.; Gesewsky, P.

    1977-11-01

    Following the nuclear bomb test the activity concentration of I 131 in air could be measured over a period of 11 days. The maximum concentration were 2.4 x 10 -13 Ci/m 3 in air and 2.7 x 10 -10 Ci/l in precipitation. The aerosolbound I 131 fraction was 80%, the rest was measured as gaseous compounds. Due to dry- and wet deposition on pastureland and uptake by grazing cows I 131 in milk from a central dairy could be measured over a period of 40 days. About 35% of the milk contamination was caused by wet deposition. I 131 in milk from this dairy was 1.2 x 10 -11 Ci/l at the time of delivery. Regarding the decay from milking to the delivery and the fraction of the cows that were not fed by fresh fodder, the above value corresponds to a maximum I 131 concentration of 1.7 x 10 -11 Ci/l. The I 131 concentration in milk when deposition hat ended shows an effective half-life of 6 days. The theoretical calculation of the milk concentration from air and precipitation values by using the actual recommended transfer data gave a 6 time higher concentration in milk than was really measured. Over the whole period of detectable I 131 concentrations in milk there could be calculated a total air to mil transfer factor of 325 Ci/l : Ci/m 3 . The radiation exposure to the thyroid was calculated to about 1 mrem for an infant and about 0,1 mrem for an adult. (orig./HP) [de

  12. Comparability of measured acceleration from accelerometry-based activity monitors.

    Science.gov (United States)

    Rowlands, Alex V; Fraysse, FranÇois; Catt, Mike; Stiles, Victoria H; Stanley, Rebecca M; Eston, Roger G; Olds, Tim S

    2015-01-01

    Accelerometers that provide triaxial measured acceleration data are now available. However, equivalence of output between brands cannot be assumed and testing is necessary to determine whether features of the acceleration signal are interchangeable. This study aimed to establish the equivalence of output between two brands of monitor in a laboratory and in a free-living environment. For part 1, 38 adults performed nine laboratory-based activities while wearing an ActiGraph GT3X+ and GENEActiv (Gravity Estimator of Normal Everyday Activity) at the hip. For part 2, 58 children age 10-12 yr wore a GT3X+ and GENEActiv at the hip for 7 d in a free-living setting. For part 1, the magnitude of time domain features from the GENEActiv was greater than that from the GT3X+. However, frequency domain features compared well, with perfect agreement of the dominant frequency for 97%-100% of participants for most activities. For part 2, mean daily acceleration measured by the two brands was correlated (r = 0.93, P acceleration values. The strong relation between accelerations measured by the two brands suggests that habitual activity level and activity patterns assessed by the GENE and GT3X+ may compare well if analyzed appropriately.

  13. Free radially expanding liquid sheet in air: time- and space-resolved measurement of the thickness field

    Science.gov (United States)

    Ligoure, Christian; Vernay, Clara; Ramos, Laurence

    2014-11-01

    The collision of a liquid drop against a small target results in the formation of a thin liquid sheet that extends radially until it reaches a maximum diameter. We have developed an original time- and space-resolved technique to measure the thickness field of this class of liquid sheet, based on the grey level measurement of the image of a dyed liquid sheet recorded using a fast camera. This method enables a precise measurement of the thickness in the range (10--450) μm, with a temporal resolution equals to that of the camera. Two asymptotic regimes for the expansion of the sheet are evidenced. The scalings of the thickness with t and r measured in the two regimes are those that were predicted but never experimentally measured before. Interestingly, our experimental data also evidence the existence of a maximum of the film thickness hmax (r) at a radial position rhmax (t) corresponding to the crossover of these two asymptotic regimes. The maximum moves with a constant velocity of the order of the impact velocity, Hence, our data has allowed one to reconcile the two apparently inconsistent theoretical predictions found in the literature Thanks to our visualization technique, we also evidence an azimuthal thickness modulation. Financial support from Solvay is acknowledged.

  14. Implicit measures of environmental attitudes: a comparative study

    Directory of Open Access Journals (Sweden)

    Martha Patricia Sánchez

    2016-01-01

    Full Text Available The present investigation aims to inquire about the capacity of three implicit instruments to measure the attitude toward natural and urban environments. One hundred and three students from a Mexican public university participated in the investigation. The implicit instruments used were the affective priming technique, the implicit association test, and the affect misattribution procedure. Further, an explicit scale was used for comparison. The results showed that all instruments converge in the same way; the nature images were viewed as more pleasant compared to the city images. Also, most results indicated good effect size values, observed power, and reliability, with the exception of the affective priming technique, which established low values. In addition, all instruments indicated weak correlations between each other. The results were discussed in terms of the capacity of the instruments to measure environmental attitudes, and also possible theoretical and methodological implications.

  15. A comparative study of calculated and measured particle velocities

    International Nuclear Information System (INIS)

    Tariq, S.M.

    2005-01-01

    After an explosive is detonated in a blast hole, seismic waves are generated in the ground surrounding the blast hole. These waves cause the particles of rock to oscillate about its position. As the wave attenuate, the particles come back to their original position. The rapidity with which the particles move is called the particle velocity. The peak or maximum velocity is the value which is of prime concern. This value of peak particle velocity can be estimated by the equations determined by the United States Bureau of Mines and by the DUPONT. A research program was conducted by the author at the 'Beck Materials Quarry' situated near Rolla, Missouri, USA. The purpose was to draw a comparison between the predicted and measured particle velocities. It was generally found that the predicted peak particle velocities were quite high as compared to the velocities measured by the Seismographs. (author)

  16. In-air and underwater hearing in the great cormorant (Phalacrocorax carbo)

    DEFF Research Database (Denmark)

    Johansen, Sasia; Larsen, Ole Næsbye; Christensen-Dalsgaard, Jakob

    2013-01-01

    The in-air and underwater hearing abilities of the great cormorant was measured using psychophysical and physiological techniques. The threshold of hearing was established at 3 frequencies in air and 4 frequencies underwater using a go-no go staircase psychophysical paradigm in an outdoor pen...... compared to other similar-sized birds. The hearing abilities in water are better than what would have been expected for a purely in-air adapted ear. [Work funded by the Carlsberg Foundation.]...

  17. Diurnal and seasonal variation in air exchange rates and interzonal flows measured by active tracer gas in five Danish homes

    DEFF Research Database (Denmark)

    Clausen, Geo; Bekö, Gabriel; Toftum, Jørn

    2016-01-01

    We measured the air exchange rates (AER) in up to six rooms in five naturally ventilated dwellings across four seasons using active tracer gas. Night time AER was also estimated in all bedrooms based on occupant-generated CO2. Additionally, we studied the pollutant distribution across the dwellings...

  18. Executive function in fibromyalgia: Comparing subjective and objective measures.

    Science.gov (United States)

    Gelonch, Olga; Garolera, Maite; Valls, Joan; Rosselló, Lluís; Pifarré, Josep

    2016-04-01

    There is evidence to suggest the existence of an executive dysfunction in people diagnosed with fibromyalgia, although there are certain inconsistencies between studies. Here, we aim to compare executive performance between patients with fibromyalgia and a control group by using subjective and objective cognitive tests, analyzing the influence of patient mood on the results obtained, and studying associations between the two measures. 82 patients diagnosed with fibromyalgia and 42 healthy controls, matched by age and years of education, were assessed using the Behavioral Rating Inventory of Executive Function - Adult Version (BRIEF-A) as a subjective measure of executive functioning. A selection of objective cognitive tests were also used to measure a series of executive functions and to identify symptoms of depression and anxiety. Patients with fibromyalgia perceived greater difficulties than the control group on all of the BRIEF-A scales. However, after adjustments were made for depression and anxiety the only differences that remained were those associated with the working memory scale and the Metacognition and Global Executive Composite index. In the case of the objective cognitive tests, a significantly worse overall performance was evidenced for the fibromyalgia patients. However, this also disappeared when adjustments were made for depression and anxiety. After this adjustment, fibromyalgia patients only performed significantly worse for the interference effect in the Stroop Test. Although there were no significant associations between most of the objective cognitive tests and the BRIEF-A scales, depression and anxiety exhibited strong associations with almost all of the BRIEF-A scales and with several of the objective cognitive tests. Patients with fibromyalgia showed executive dysfunction in subjective and objective measures, although most of this impairment was associated with mood disturbances. Exceptions to this general rule were observed in the

  19. Cryogenic current comparators for precise ion beam current measurements

    International Nuclear Information System (INIS)

    Kurian, Febin

    2015-01-01

    The planned Facility for Antiproton and Ion Research (FAIR) at GSI has to cope with a wide range of beam intensities in its high-energy beam transport systems and in the storage rings. To meet the requirements of a non-intercepting intensity measurement down to nA range, it is planned to install a number of Cryogenic Current Comparator (CCC) units at different locations in the FAIR beamlines. In this work, the first CCC system for intensity measurement of heavy ion beams, which was developed at GSI, was re-commissioned and upgraded to be used as a 'GSI - CCC prototype' for extensive optimization and development of an improved CCC for FAIR. After installation of a new SQUID sensor and related electronics, as well as implementation of improved data acquisition components, successful beam current measurements were performed at a SIS18 extraction line. The measured intensity values were compared with those of a Secondary Electron Monitor (SEM). Furthermore, the spill-structure of a slowly extracted beam was measured and analyzed, investigating its improvement due to bunching during the slow-extraction process. Due to the extreme sensitivity of the superconducting sensor, the determined intensity values as well as the adjustment of the system for optimal performance are strongly influenced by the numerous noise sources of the accelerators environment. For this reason, detailed studies of different effects caused by noise have been carried out, which are presented together with proposals to reduce them. Similarly, studies were performed to increase the dynamic range and overcome slew rate limitations, the results of which are illustrated and discussed as well. By combining the various optimizations and characterizations of the GSI CCC prototype with the experiences made during beam operation, criteria for a more efficient CCC System could be worked out, which are presented in this work. The details of this new design are worked out with respect to the

  20. De novo likelihood-based measures for comparing genome assemblies.

    Science.gov (United States)

    Ghodsi, Mohammadreza; Hill, Christopher M; Astrovskaya, Irina; Lin, Henry; Sommer, Dan D; Koren, Sergey; Pop, Mihai

    2013-08-22

    The current revolution in genomics has been made possible by software tools called genome assemblers, which stitch together DNA fragments "read" by sequencing machines into complete or nearly complete genome sequences. Despite decades of research in this field and the development of dozens of genome assemblers, assessing and comparing the quality of assembled genome sequences still relies on the availability of independently determined standards, such as manually curated genome sequences, or independently produced mapping data. These "gold standards" can be expensive to produce and may only cover a small fraction of the genome, which limits their applicability to newly generated genome sequences. Here we introduce a de novo  probabilistic measure of assembly quality which allows for an objective comparison of multiple assemblies generated from the same set of reads. We define the quality of a sequence produced by an assembler as the conditional probability of observing the sequenced reads from the assembled sequence. A key property of our metric is that the true genome sequence maximizes the score, unlike other commonly used metrics. We demonstrate that our de novo  score can be computed quickly and accurately in a practical setting even for large datasets, by estimating the score from a relatively small sample of the reads. To demonstrate the benefits of our score, we measure the quality of the assemblies generated in the GAGE and Assemblathon 1 assembly "bake-offs" with our metric. Even without knowledge of the true reference sequence, our de novo  metric closely matches the reference-based evaluation metrics used in the studies and outperforms other de novo  metrics traditionally used to measure assembly quality (such as N50). Finally, we highlight the application of our score to optimize assembly parameters used in genome assemblers, which enables better assemblies to be produced, even without prior knowledge of the genome being assembled. Likelihood

  1. Measurement and estimated health risks of volatile organic compounds and polychlorinated biphenyls in air at the Hanford Site

    International Nuclear Information System (INIS)

    Patton, G.W.; Cooper, A.T.; Blanton, M.L.

    1994-10-01

    A variety of radioactive and nonradioactive chemicals have been released in effluent streams and discharged to waste disposal facilities during the nuclear materials production period at the Hanford Site. Extensive environmental surveillance for radioactive materials has occurred at Hanford; however, only limited information is available on the types and concentrations of organic pollutants potentially present. This report describes work performed to provide the Hanford Site Surface Environmental Surveillance Project with representative air concentration data for volatile organic compounds and polychlorinated biphenyls (PCBs). US Environmental Protection Agency (USEPA) volatile organic compound sampling methods evaluated for Hanford Site use were carbon-based adsorbent traps (TO-2) and Summa air canisters (TO-14). Polychlorinated biphenyls were sampled using USEPA method (TO-4), which uses glass fiber filters and polyurethane foam adsorbent beds to collect the PCBS. This report also presents results for environmental surveillance samples collected for volatile organic compound and PCB analyses from 1990 to 1993. All measured air concentrations of volatile organic compounds and PCBs were well below applicable maximum allowable concentration standards for air contaminants. Because of the lack of ambient air concentration standards, a conservative estimate is provided of the potential human health impacts from exposure to the ambient air concentrations measured on the Hanford Site

  2. Measurement of liquid film thickness in air - water two phase flows in conventional and mini channels using image processing

    Energy Technology Data Exchange (ETDEWEB)

    Seshadri, Arunkumar; Mahadevan, Swetha; Muniyandi, Venkatesan [SASTRA University, Thanjavur (India)

    2015-05-15

    The measurement and study of liquid films in the case of two phase flows is significant in many heat transfer and mass transfer applications, such as chemical process industries, micro reactors, coating processes and in boilers. The focus of the present study was to measure and characterize the thickness of the liquid films for various two phase flow regimes in conventional and in mini channels using a non-intrusive technique. Experiments were performed on tubes of diameters 0.6, 1.5, 2.6 and 3.4mm. The superficial velocities of gas and liquid are in the range of 0.01-50 and 0.01-3m/s, respectively. The flow patterns were recorded with a high speed camera. A method to determine the two phase flow velocity using image registration has been discussed. Morphological processing and gray scale analysis were used to determine the liquid film thickness and characterize the flow regimes. The flow patterns identified are bubbly, dispersed bubbly, slug, slug-annular, wavy-annular, stratified, and annular. The flow regimes were validated with flow maps available in the literature. The liquid film thickness was identified by distance transform technique in image processing. The magnitude of film thickness varied with liquid and gas flow velocities. The film thickness was represented in terms of capillary number. The variation in film thickness along the length of the flow regime has been discussed. A relation between the liquid film thicknesses measured using the non-intrusive image processing technique and capillary number for the conventional and mini tubes is proposed based on the analysis. h/d=2.03Ca{sup 0.13}We{sup 0.52} for Bo>1 h/d=1.08Ca{sup 0.4}We{sup 0.35} for Bo<1 It is concluded from the proposed correlation that the variation in liquid film thickness is different for conventional and mini channels because of the effect of inertial dominance in conventional channels and viscous dominance in mini channels.

  3. A high precision mass spectrometry method for measuring O2/N2 ratios and CO2 concentrations in air

    International Nuclear Information System (INIS)

    Marca, A.D.; Dennis, P.F.; Etchells, A.

    2002-01-01

    A full, detailed understanding of the global carbon budget is needed for robust modelling of global climate and environmental change. Since the industrial revolution the carbon cycle has been shifted from a steady state in which removal of CO 2 from the atmosphere through photosynthesis is balanced by its addition through respiration. Currently increased respiration due to deforestation, modern agricultural practises and the burning of fossil fuels dominates photosynthesis resulting in modern atmospheric CO 2 concentrations some 32% higher than the year 1800 levels. However, the CO 2 concentration rises are lower than expected from known fossil fuel combustion inventories. A significant proportion of the excess CO 2 is taken up by the oceans, however a missing carbon sink must still be invoked to account for the difference between measured and expected CO 2 rises. A global greening as a result of increased photosynthesis is required to close the circle

  4. Measurements of gas and particle polycyclic aromatic hydrocarbons (PAHs) in air at urban, rural and near-roadway sites

    Science.gov (United States)

    Pratt, G. C.; Herbrandson, C.; Krause, M. J.; Schmitt, C.; Lippert, C. J.; McMahon, C. R.; Ellickson, K. M.

    2018-04-01

    We measured polycyclic aromatic hydrocarbons (PAHs) in gas and particle phases over two years using high volume samplers equipped with quartz fiber filters and XAD-4 at a rural site, an urban site, and a site adjacent to a heavily trafficked roadway. Overall results were generally as expected, in that concentrations increased from rural to urban to near-roadway sites, and PAHs with high vapor pressures (liquid subcooled, PoL) and low octanol-air partition coefficients (Koa) were mainly in the gas phase, while those with low PoL and high Koa were predominantly in the particle phase. Intermediate PAHs existed in both phases with the phase distribution following a seasonal pattern of higher gas phase concentrations in summer due to temperature effects. The overall pattern of phase distribution was consistent with PAH properties and ambient conditions and was similar at all three sites. The particle-bound fraction (ϕ) was well-described empirically by nonlinear regressions with log Koa and log PoL as predictors. Adsorption and absorption models underestimated the particle-bound fraction for most PAHs. The dual aerosol-air/soot-air model generally represented the gas-particle partitioning better than the other models across all PAHs, but there was a tendency to underestimate the range in the particle-bound fraction seen in measurements. There was a statistically insignificant tendency for higher PAHs in the particle phase at the near roadway site, and one piece of evidence that PAHs may be enriched on ultrafine particles at the near roadway site. Understanding the phase and particle size distributions of PAHs in highly polluted, high exposure microenvironments near traffic sources will help shed light on potential health effects.

  5. Comparing Measures of Estuarine Ecosystem Production in a ...

    Science.gov (United States)

    Anthropogenic nutrient enrichments and concerted efforts at nutrient reductions, compounded with the influences of climate change, are likely changing the net ecosystem production (NEP) of our coastal systems. To quantify these changes, scientists monitor a range of physical, chemical, and biological parameters sampled at various frequencies. Water column chlorophyll concentrations are arguably the most commonly used indicator of net phytoplankton production, as well as a coarse indicator of NEP. We compared parameters that estimate production, including chlorophyll, across an experimental nutrient gradient and in situ in both well-mixed and stratified estuarine environments. Data from an experiment conducted in the early 1980s in mesocosms designed to replicate a well-mixed mid-Narragansett Bay (Rhode Island) water column were used to correlate changes in chlorophyll concentrations, pH, dissolved oxygen (O2), dissolved inorganic nitrogen, phosphate, and silicate concentrations, cell counts, and 14C carbon uptake measurements across a range of nutrient enrichments. The pH, O2, nutrient, and cell count measurements reflected seasonal cycles of spring blooms followed by late summer/early fall respiration periods across nutrient enrichments. Chlorophyll concentrations were more variable and rates of 14C productivity were inconsistent with observed trends in nutrient concentrations, pH, and O2 concentrations. Similar comparisons were made using data from a well-mixe

  6. A new certified reference material for benzene measurement in air on a sorbent tube: development and proficiency testing

    Energy Technology Data Exchange (ETDEWEB)

    Caurant, A. [Laboratoire National de Metrologie et d' Essais, Paris (France); Universite Paris 12 et CNRS (UMR 7583), Faculte des Sciences et Technologie, Laboratoire Inter-universitaire des Systemes Atmospheriques, Unite Mixte de Recherche Universite Paris 7 (France); Lalere, B.; Schbath, M.C.; Stumpf, C.; Sutour, C.; Mace, T.; Vaslin-Reimann, S. [Laboratoire National de Metrologie et d' Essais, Paris (France); Quisefit, J.P.; Doussin, J.F. [Universite Paris 12 et CNRS (UMR 7583), Faculte des Sciences et Technologie, Laboratoire Inter-universitaire des Systemes Atmospheriques, Unite Mixte de Recherche Universite Paris 7 (France)

    2010-11-15

    A certified matrix reference material (CRM) for the measurement of benzene in ambient air has been developed at Laboratoire National de Metrologie et d'Essais. The production of these CRMs was conducted using a gravimetric method fully traceable to the International System of Units. The CRMs were prepared by sampling an accurate mass of a gaseous primary reference material of benzene, using a high-precision laminar flowmeter and a mass flow controller, with a PerkinElmer sampler filled with Carbopack trademark X sorbent. The relative standard deviations obtained for the preparation of a batch of 20 tubes loaded with 500 ng of benzene were below 0.2%. Each CRM is considered independent from the others and with its own certified value and an expanded uncertainty estimated to be within 0.5%, lower than the uncertainties of benzene CRMs already available worldwide. The stability of these materials was also established up to 12 months. These CRMs were implemented during proficiency testing, to evaluate the analytical performances of seven French laboratories involved in benzene air monitoring. (orig.)

  7. The neuroergonomic evaluation of human machine interface design in air traffic control using behavioral and EGG/ERP measures.

    Science.gov (United States)

    Giraudet, L; Imbert, J-P; Bérenger, M; Tremblay, S; Causse, M

    2015-11-01

    The Air Traffic Control (ATC) environment is complex and safety-critical. Whilst exchanging information with pilots, controllers must also be alert to visual notifications displayed on the radar screen (e.g., warning which indicates a loss of minimum separation between aircraft). Under the assumption that attentional resources are shared between vision and hearing, the visual interface design may also impact the ability to process these auditory stimuli. Using a simulated ATC task, we compared the behavioral and neural responses to two different visual notification designs--the operational alarm that involves blinking colored "ALRT" displayed around the label of the notified plane ("Color-Blink"), and the more salient alarm involving the same blinking text plus four moving yellow chevrons ("Box-Animation"). Participants performed a concurrent auditory task with the requirement to react to rare pitch tones. P300 from the occurrence of the tones was taken as an indicator of remaining attentional resources. Participants who were presented with the more salient visual design showed better accuracy than the group with the suboptimal operational design. On a physiological level, auditory P300 amplitude in the former group was greater than that observed in the latter group. One potential explanation is that the enhanced visual design freed up attentional resources which, in turn, improved the cerebral processing of the auditory stimuli. These results suggest that P300 amplitude can be used as a valid estimation of the efficiency of interface designs, and of cognitive load more generally. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. A sensitive LC-MS/MS method for measurement of organophosphorus pesticides and their oxygen analogs in air sampling matrices.

    Science.gov (United States)

    Armstrong, Jenna L; Dills, Russell L; Yu, Jianbo; Yost, Michael G; Fenske, Richard A

    2014-01-01

    A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15-1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78-113% from XAD-2 active air sampling tubes and 71-108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74-94% after time periods ranging from 2-10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method.

  9. Comparing pulmonary resistance measured with an esophageal balloon to resistance measurements with an airflow perturbation device

    International Nuclear Information System (INIS)

    Coursey, D C; Johnson, A T; Scharf, S M

    2010-01-01

    The airflow perturbation device (APD) perturbs flow and mouth pressure during regular breathing. Ratios of mouth pressure perturbation magnitudes to flow perturbation magnitudes were used to calculate inspiratory, expiratory and average respiratory resistances. Resistance measurements with the APD were compared to pulmonary resistances directly measured with an esophageal balloon. Six healthy subjects were tested during tidal breathing when known external resistances were added during inspiration, during expiration and during both inspiration and expiration. When the baseline averaged balloon measured pulmonary resistance was subtracted from the baseline averaged APD measured resistance, the difference between them was 0.92 ± 1.25 (mean ± SD) cmH 2 O L –1 s –1 . Compared to the magnitude of the known increase in the added resistance, the APD measured resistance increased by 79%, whereas directly measured pulmonary resistance increased only by 56%. During addition of external resistances to both inspiration and expiration, the changes in inspiratory and expiratory pulmonary resistance were only 36% and 62% of the added resistance, respectively. On the other hand, the APD inhalation and exhalation resistance measured between 82% and 76% of the added resistance. We conclude that the APD detects changes in external resistance at least as well as, and probably better than, classical measurements of pulmonary resistance

  10. Methodology for setting the reference levels in the measurements of the dose rate absorbed in air due to the environmental gamma radiation

    International Nuclear Information System (INIS)

    Dominguez Ley, Orlando; Capote Ferrera, Eduardo; Caveda Ramos, Celia; Alonso Abad, Dolores

    2008-01-01

    Full text: The methodology for setting the reference levels of the measurements of the gamma dose rate absorbed in the air is described. The registration level was obtained using statistical methods. To set the alarm levels, it was necessary to begin with certain affectation level, which activates the investigation operation mode when being reached. It is was necessary to transform this affectation level into values of the indicators selected to set the appearance of an alarm in the network, allowing its direct comparison and at the same time a bigger operability of this one. The affectation level was assumed as an effective dose of 1 mSv/y, which is the international dose limit for public. The conversion factor obtained in a practical way as a consequence of the Chernobyl accident was assumed, converting the value of annual effective dose into values of effective dose rate in air. These factors are the most important in our work, since the main task of the National Network of Environmental Radiological Surveillance of the Republic of Cuba is detecting accidents with a situations regional affectation, and this accident is precisely an example of pollution at this scale. The alarm level setting was based on the results obtained in the first year of the Chernobyl accident. For this purpose, some transformations were achieved. In the final results, a correction factor was introduced depending on the year season the measurement was made. It was taken into account the influence of different meteorological events on the measurement of this indicator. (author)

  11. Measurements by activation foils and comparative computations by MCNP code

    International Nuclear Information System (INIS)

    Kyncl, J.

    2008-01-01

    Systematic study of the radioactive waste minimisation problem is subject of the SPHINX project. Its idea is that burning or transmutation of the waste inventory problematic part will be realized in a nuclear reactor the fuel of which is in the form of liquid fluorides. In frame of the project, several experiments have been performed with so-called inserted experimental channel. The channel was filled up by the fluorides mixture, surrounded by six fuel assemblies with moderator and placed into LR-0 reactor vessel. This formation was brought to critical state and measurement with activation foil detectors were carried out at selected positions of the inserted channel. Main aim of the measurements was to determine reaction rates for the detectors mentioned. For experiment evaluation, comparative computations were accomplished by code MCNP4a. The results obtained show that very often, computed values of reaction rates differ substantially from the values that were obtained from the experiment. This contribution deals with analysis of the reasons of these differences from the point of view of computations by Monte Carlo method. The analysis of concrete cases shows that the inaccuracy of reaction rate computed is caused mostly by three circumstances:-space region that is occupied by detector is relatively very small;- microscopic effective cross-section R(E) of the reaction changes strongly with energy just in the energy interval that gives the greatest contribution to the reaction; - in the energy interval that gives the greatest contribution to reaction rate, the error of the computed neutron flux is great. These circumstances evoke that the computation of reaction rate with casual accuracy submits extreme demands on computing time. (Author)

  12. Comparative Study of the Volumetric Methods Calculation Using GNSS Measurements

    Science.gov (United States)

    Şmuleac, Adrian; Nemeş, Iacob; Alina Creţan, Ioana; Sorina Nemeş, Nicoleta; Şmuleac, Laura

    2017-10-01

    This paper aims to achieve volumetric calculations for different mineral aggregates using different methods of analysis and also comparison of results. To achieve these comparative studies and presentation were chosen two software licensed, namely TopoLT 11.2 and Surfer 13. TopoLT program is a program dedicated to the development of topographic and cadastral plans. 3D terrain model, level courves and calculation of cut and fill volumes, including georeferencing of images. The program Surfer 13 is produced by Golden Software, in 1983 and is active mainly used in various fields such as agriculture, construction, geophysical, geotechnical engineering, GIS, water resources and others. It is also able to achieve GRID terrain model, to achieve the density maps using the method of isolines, volumetric calculations, 3D maps. Also, it can read different file types, including SHP, DXF and XLSX. In these paper it is presented a comparison in terms of achieving volumetric calculations using TopoLT program by two methods: a method where we choose a 3D model both for surface as well as below the top surface and a 3D model in which we choose a 3D terrain model for the bottom surface and another 3D model for the top surface. The comparison of the two variants will be made with data obtained from the realization of volumetric calculations with the program Surfer 13 generating GRID terrain model. The topographical measurements were performed with equipment from Leica GPS 1200 Series. Measurements were made using Romanian position determination system - ROMPOS which ensures accurate positioning of reference and coordinates ETRS through the National Network of GNSS Permanent Stations. GPS data processing was performed with the program Leica Geo Combined Office. For the volumetric calculating the GPS used point are in 1970 stereographic projection system and for the altitude the reference is 1975 the Black Sea projection system.

  13. Smile line assessment comparing quantitative measurement and visual estimation

    NARCIS (Netherlands)

    Geld, P. Van der; Oosterveld, P.; Schols, J.; Kuijpers-Jagtman, A.M.

    2011-01-01

    INTRODUCTION: Esthetic analysis of dynamic functions such as spontaneous smiling is feasible by using digital videography and computer measurement for lip line height and tooth display. Because quantitative measurements are time-consuming, digital videography and semiquantitative (visual) estimation

  14. Comparing the Measured and Latent Dark Triad: Are Three Measures Better than One?

    Directory of Open Access Journals (Sweden)

    Peter K. Jonason

    2011-10-01

    Full Text Available Could measurement level be a factor worth considering when studying the Dark Triad (i.e., narcissism, psychopathy, and Machiavellianism? In two studies (N  = 465, we compared the relative fit of two Dark Triad models: one that treats the three measures as separate-yet-related personality traits and another that treats the measures as tapping a single, latent construct. Mid-level personality traits, such as mate-retention strategies (Study 1 were best explained by a three-measure model, whereas the higher-order trait of sociosexuality (Study 2, were best explained by a single, latent-factor model. When considering mid-level measurement in personality, the three traits may provide independent effects for interpersonal relationships, whereas at the higher-order level, the three traits may function as a single entity relating to other higher-order traits. We suggest one should consider level of measurement between the predictor and criterion variables to better predict correlations among variables such as the Dark Triad. DOI: 10.2458/azu_jmmss.v2i1.12363

  15. Comparative analyses of measured evapotranspiration for various land surfaces

    Science.gov (United States)

    Suat Irmak

    2016-01-01

    There is a significant lack of continuously measured ET data for multiple land surfaces in the same area to be able to make comparisons of water use rates of different agroecosystems. This research presentation will provide continuous evapotranspiration and other surface energy balance variables measured above multiple land use and management practices.

  16. Comparative analysis of colour change measurement devices in textile industry

    Directory of Open Access Journals (Sweden)

    Paulina Gilewicz

    2014-08-01

    Full Text Available In the paper there is presented a trial of application of new measurement principle of colour change with the use of DigiEye device. Comparison of DigiEye with commonly use in the textile industry spectrophotometer Macbeth 2020 was an aim of determination of relationship between parameters of both measurement systems. Samples for the colour change assessment on both measurement systems were first aged in the Xenotest 150. Ageing process was done according to the method of blues scale. Results were obtained by the colour measurement devices before and after the ageing test each releasing the diaphragms during exposing the examined samples on the light. Result of colour change were obtained in the colour system CIE L*a*b*. The measurements were done for PES fabrics destined on the outer layers of clothing. [b]Keywords[/b]: textiles, spectrophotometer, colorimeter [b][/b

  17. Why Choice Matters: Revisiting and Comparing Measures of Democracy

    Directory of Open Access Journals (Sweden)

    Heiko Giebler

    2018-03-01

    Full Text Available Measures of democracy are in high demand. Scientific and public audiences use them to describe political realities and to substantiate causal claims about those realities. This introduction to the thematic issue reviews the history of democracy measurement since the 1950s. It identifies four development phases of the field, which are characterized by three recurrent topics of debate: (1 what is democracy, (2 what is a good measure of democracy, and (3 do our measurements of democracy register real-world developments? As the answers to those questions have been changing over time, the field of democracy measurement has adapted and reached higher levels of theoretical and methodological sophistication. In effect, the challenges facing contemporary social scientists are not only limited to the challenge of constructing a sound index of democracy. Today, they also need a profound understanding of the differences between various measures of democracy and their implications for empirical applications. The introduction outlines how the contributions to this thematic issue help scholars cope with the recurrent issues of conceptualization, measurement, and application, and concludes by identifying avenues for future research.

  18. Evaluation of the salt deposition on the canister surface of concrete cask. Part 3. Long-term measurement of salt concentration in air and evaluation of the salt deposition

    International Nuclear Information System (INIS)

    Wataru, Masumi; Takeda, Hirofumi

    2015-01-01

    To realize the dry storage using concrete cask in Japan, it is important to develop the evaluation method of the SCC of the canister. One of the key issues is sea salt deposition on the canister surface during the storage period. If the amount of salt deposition exceeds the critical value, the SCC may occur. The amount of salt deposition depends on the ambient air condition. We developed the measurement device of salt in air to make clear the ambient condition. The device sucks the air including sea salt and the sea salt dissolves in water. We analyze the water including sea salt. This device works automatically for one or two months. In this study, the performance of this device was verified comparing the data obtained by the air sampler using filter pack. In Yokosuka area of CRIEPI, we measured the ambient air condition using this device for three years. Furthermore, we performed the salt deposition test using the small ducts in the same area. The ambient air including sea salt flows in the duct and the sea salt deposits on the test specimen put on the duct inner surface. We took out the specimen after certain time and measured the salt amount on the test specimen. Using these data, we obtained the relation between the salt deposition and the time on this ambient condition. The results of this study are useful to evaluate the SCC of the canister. (author)

  19. Correction: The stability and generation pattern of thermally formed isocyanic acid (ICA) in air - potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements.

    Science.gov (United States)

    Jankowski, Mikolaj Jan; Olsen, Raymond; Thomassen, Yngvar; Molander, Paal

    2018-02-21

    Correction for 'The stability and generation pattern of thermally formed isocyanic acid (ICA) in air - potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements' by Mikolaj Jan Jankowski et al., Environ. Sci.: Processes Impacts, 2016, 18, 810-818.

  20. Measuring the effect of ion-induced drift-gas polarization on the electrical mobilities of multiply-charged ionic liquid nanodrops in air.

    Science.gov (United States)

    Fernández-García, Juan; Fernández de la Mora, Juan

    2013-12-01

    The electrical mobilities of multiply-charged nanodrops of the ionic liquid 1-ethyl, 3-methylimidazolium dicyanamide (EMI-N[CN]2) were accurately measured in air at 20 °C for mass-selected clusters of composition [EMI-N[CN]2] n [EMI(+)] z , with 2 ≤ n ≤ 369 and 1 ≤ z ≤ 10. We confirm prior reports that the mobility Z of a globular ion of mass m is given approximately by the modified Stokes-Millikan law for spheres, Z  =  Z SM,mod (d m   +  d g , z, m), where d m   =  (6m/πρ)(1/3) is the nanodrop mass-diameter based on the density ρ of the liquid (corrected for the capillary compression and electrostatic deformation of the nanodrop), and d g is an effective air molecule diameter. There is however a measurable (up to 7%) and systematic z-dependent departure of Z from Z SM,mod . As theoretically expected at small ε (*) , this effect is accurately described by a simple correction factor of the form Z/Z SM,mod   =  δ(1  -  βε (*)), where kTε (*) is the potential energy due to the ion-induced dipole (polarization) attraction between a perfectly-conducting charged nanodrop and a polarized neutral gas-molecule at a distance (d m   +  d g )/2 from its center. An excellent fit of this model to hundreds of data points is found for d g ≈ 0.26 nm, β ≈ 0.36, and δ ≈ 0.954. Accounting for the effect of polarization decreases d g considerably with respect to values inferred from earlier nanodrop measurements that ignored this effect. In addition, and in spite of ambiguities in the mobility calibration scale, the measured constant δ smaller than unity increases Millikan's drag enhancement factor from the accepted value ξ m ≈ 1.36 to the new value ξ ≈ ξ m /δ ≈ 1.42  ± 0.03.

  1. Measuring the Effect of Ion-Induced Drift-Gas Polarization on the Electrical Mobilities of Multiply-Charged Ionic Liquid Nanodrops in Air

    Science.gov (United States)

    Fernández-García, Juan; Fernández de la Mora, Juan

    2013-12-01

    The electrical mobilities of multiply-charged nanodrops of the ionic liquid 1-ethyl, 3-methylimidazolium dicyanamide (EMI-N[CN]2) were accurately measured in air at 20 °C for mass-selected clusters of composition [EMI-N[CN]2] n [EMI+] z , with 2 ≤ n ≤ 369 and 1 ≤ z ≤ 10. We confirm prior reports that the mobility Z of a globular ion of mass m is given approximately by the modified Stokes-Millikan law for spheres, Z = Z SM, mod ( d m + d g , z, m), where d m = (6 m/ πρ)1/3 is the nanodrop mass-diameter based on the density ρ of the liquid (corrected for the capillary compression and electrostatic deformation of the nanodrop), and d g is an effective air molecule diameter. There is however a measurable (up to 7 %) and systematic z-dependent departure of Z from Z SM,mod . As theoretically expected at small ɛ * , this effect is accurately described by a simple correction factor of the form Z/ Z SM, mod = δ(1 - βɛ *), where kTɛ * is the potential energy due to the ion-induced dipole ( polarization) attraction between a perfectly-conducting charged nanodrop and a polarized neutral gas-molecule at a distance ( d m + d g )/2 from its center. An excellent fit of this model to hundreds of data points is found for d g ≈ 0.26 nm, β ≈ 0.36, and δ ≈ 0.954. Accounting for the effect of polarization decreases d g considerably with respect to values inferred from earlier nanodrop measurements that ignored this effect. In addition, and in spite of ambiguities in the mobility calibration scale, the measured constant δ smaller than unity increases Millikan's drag enhancement factor from the accepted value ξ m ≈ 1.36 to the new value ξ ≈ ξ m / δ ≈ 1.42 ± 0.03.

  2. Consistent measurements comparing the drift features of noble gas mixtures

    CERN Document Server

    Becker, U; Fortunato, E M; Kirchner, J; Rosera, K; Uchida, Y

    1999-01-01

    We present a consistent set of measurements of electron drift velocities and Lorentz deflection angles for all noble gases with methane and ethane as quenchers in magnetic fields up to 0.8 T. Empirical descriptions are also presented. Details on the World Wide Web allow for guided design and optimization of future detectors.

  3. Consistent measurements comparing the drift features of noble gas mixtures

    International Nuclear Information System (INIS)

    Becker, U.; Dinner, R.; Fortunato, E.; Kirchner, J.; Rosera, K.; Uchida, Y.

    1999-01-01

    We present a consistent set of measurements of electron drift velocities and Lorentz deflection angles for all noble gases with methane and ethane as quenchers in magnetic fields up to 0.8 T. Empirical descriptions are also presented. Details on the World Wide Web allow for guided design and optimization of future detectors

  4. Comparing measured with simulated vertical soil stress under vehicle load

    DEFF Research Database (Denmark)

    Keller, Thomas; Lamandé, Mathieu; Arvidsson, Johan

    The load transfer within agricultural soil is typically modelled on the basis of the theory of stress transmission in elastic media, usually in the semi-empirical form that includes the “concentration factor” (v). Measurements of stress in soil are needed to evaluate model calculations, but may...... be biased because transducers do not read true stresses. The aim of this paper was to measure and simulate soil stress under defined loads. First, we investigated the accuracy of the transducers in situ by measuring stress at high spatial and temporal resolution at 0.1 m depth under a known load. Stress...... in the soil profile at 0.3, 0.5 and 0.7 m depth was measured during wheeling at field capacity on five soils (13-66% clay). Stress propagation was then simulated with the semi-analytical model, using vertical stress at 0.1 m depth estimated from tyre characteristics as upper boundary condition, and v...

  5. Comparing Alternative Instruments to Measure Service Quality in Higher Education

    Science.gov (United States)

    Brochado, Ana

    2009-01-01

    Purpose: The purpose of this paper is to examine the performance of five alternative measures of service quality in the high education sector--service quality (SERVQUAL), importance-weighted SERVQUAL, service performance (SERVPERF), importance-weighted SERVPERF, and higher education performance (HEdPERF). Design/methodology/approach: Data were…

  6. Measuring Transnationalism: Comparing TV Formats using Digital Tools

    NARCIS (Netherlands)

    Larkey, Edward; Digeon, Landry; Er, Ibrahim

    2016-01-01

    abstractThis article elucidates a typology for cross-culturally comparing different versions of television formats. Digital tools are used to derive quantitative data based on temporal parameters of episode or genre of the narrative structure, content, and sequencing. Type one, which we also call

  7. Comparing the lived experience to objective measures of Accessibility

    OpenAIRE

    Angela Curl; John Nelson; Jillian Anable

    2011-01-01

    This paper presents work undertaken to date as part of PhD research into the process of Accessibility Planning in the UK and how existing objective measures of accessibility relate to individual perceptions or the "lived experience" of accessibility. Since 1997, Accessibility has been framed in the social exclusion context within UK transport planning and policy, focusing on the ability of people to participate fully in society, which is seen as being limited by poor accessibility. This appro...

  8. Comparative Measurements of Indoor Radon in Homes and Floating Houses

    International Nuclear Information System (INIS)

    Changmuang, Wirote; Tantawiroon, Malulee; Polphong, Pornsri

    2003-06-01

    A survey of the radon ( 222 Rn) concentrations in 318 homes and 152 floating houses (1410 samples) in Phitsanulok province, using a passive 222 Rn charcoal canister and measurement by gamma spectrometry. Floating houses showed significant lower mean levels (8.22 Bqm -3 ) than homes (21.56 Bqm -3 ) (p 222 Rn concentrations indicated that concrete homes had a higher level than wooden homes and homes lying on ground had a higher level than those built at 1 meter or more above ground. The estimated annual mean effective dose equivalent 0.35 mSvy -1 and the annual lung dose equivalent of 5.94 mSvy -1 were only one-third of the world mean estimates

  9. Atmospheric stability and complex terrain: comparing measurements and CFD

    DEFF Research Database (Denmark)

    Koblitz, Tilman; Bechmann, Andreas; Berg, Jacob

    2014-01-01

    -neutral atmospheric flow over complex terrain including physical processes like stability and Coriolis force. We examine the influence of these effects on the whole atmospheric boundary layer using the DTU Wind Energy flow solver EllipSys3D. To validate the flow solver, measurements from Benakanahalli hill, a field...... experiment that took place in India in early 2010, are used. The experiment was specifically designed to address the combined effects of stability and Coriolis force over complex terrain, and provides a dataset to validate flow solvers. Including those effects into EllipSys3D significantly improves......For wind resource assessment, the wind industry is increasingly relying on Computational Fluid Dynamics models that focus on modeling the airflow in a neutrally stratified surface layer. So far, physical processes that are specific to the atmospheric boundary layer, for example the Coriolis force...

  10. International Workshop on Comparing Ice Nucleation Measuring Systems 2014

    Energy Technology Data Exchange (ETDEWEB)

    Cziczo, Daniel [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2016-04-30

    The relationship of ambient aerosol particles to the formation of ice-containing clouds is one of the largest uncertainties in understanding the Earth’s climate. The uncertainty is due to several poorly understood processes and measurements including, but not limited to: (1) the microphysics of how particles nucleate ice, (2) the number of ice forming particles as a function of atmospheric properties such as temperature and relative humidity, (3) the atmospheric distribution of ice forming particles and (4) the role of anthropogenic activities in producing or changing the behavior of ice forming particles. The ways in which ice forming particles can impact climate is also multi-faceted. More ice forming particles can lead to clouds with more ice crystals and different optical properties than clouds with less ice forming particles. More effective ice forming particles can lead to ice at higher temperature and/or lower saturation, resulting in clouds at lower altitude or latitude which also changes the Earth’s radiative balance. Ice nucleation also initiates most of the Earth’s precipitation, even in the mid- and low-latitudes, since cloud-top temperatures are often below freezing. The limited measurements and lack of understanding directly translates to restrictions in our ability to model atmospheric ice formation and project changes into the future. The importance of ice nucleation research is further exemplified by Figure 1 which shows the publications per decade and citations per year on the topic of ice nucleation [DeMott et al., 2011]. After a lull at the end of the last century, there has been a dramatic increase in both publications and citations related to ice nucleation; this directly corresponds to the importance of ice nucleation on the Earth’s climate and the uncertainty in this area noted by the Solomon [2007].

  11. Measuring Transnationalism: Comparing TV Formats using Digital Tools

    Directory of Open Access Journals (Sweden)

    Edward Larkey

    2016-08-01

    Full Text Available This article elucidates a typology for cross-culturally comparing different versions of television formats. Digital tools are used to derive quantitative data based on temporal parameters of episode or genre of the narrative structure, content, and sequencing. Type one, which we also call “transposed narratives,” retains the narrative structure and sequencing while extending and expanding the narrative structure to readjust to longer broadcast times. Type two, which we call ‘transmutated narratives,’ re-distributes and re-organizes the narrative structure and sequencing to adjust to both extended broadcast time and other culturally relevant proximity issues. Type three adaptations display genre structure similarities while narrative structure, sequencing and content diverge. These we call ‘derived narratives.’

  12. Heating rate measurements over 30 deg and 40 deg (half angle) blunt cones in air and helium in the Langley expansion tube facility

    Science.gov (United States)

    Reddy, N. M.

    1980-01-01

    Convective heat transfer measurements, made on the conical portion of spherically blunted cones (30 deg and 40 deg half angle) in an expansion tube are discussed. The test gases used were helium and air; flow velocities were about 6.8 km/sec for helium and about 5.1 km/sec for air. The measured heating rates are compared with calculated results using a viscous shock layer computer code. For air, various techniques to determine flow velocity yielded identical results, but for helium, the flow velocity varied by as much as eight percent depending on which technique was used. The measured heating rates are in satisfactory agreement with calculation for helium, assuming the lower flow velocity, the measurements are significantly greater than theory and the discrepancy increased with increasing distance along the cone.

  13. Comparing Measurement Error between Two Different Methods of Measurement of Various Magnitudes

    Science.gov (United States)

    Zavorsky, Gerald S.

    2010-01-01

    Measurement error is a common problem in several fields of research such as medicine, physiology, and exercise science. The standard deviation of repeated measurements on the same person is the measurement error. One way of presenting measurement error is called the repeatability, which is 2.77 multiplied by the within subject standard deviation.…

  14. COMPARATIVE STUDY OF RADON AND THORON MEASUREMENTS IN FOUR ROMANIAN SHOW CAVES.

    Science.gov (United States)

    Burghele, B D; Cucos, A; Papp, B; Dicu, T; Pressyanov, D; Dimitrov, D; Dimitrova, I; Constantin, S

    2017-11-01

    Measurements have been carried out using four types of passive detectors in four of the most popular show caves in Romania. Three types of detectors (RSKS, RadTrak and CD) were used for radon measurements and two (Raduet and CD) for thoron measurement. Activity concentrations in air were measured in the same locations for two seasons, autumn and winter. Measured values for the different caves varied between below detection limit (5 Bq m-3) and 4024 Bq m-3 for radon and from below 10 to 583 Bq m-3 for thoron. The results indicate a very good correlation between RSKS and RadTrak detectors (r = 0.96). The most significant difference between radon concentrations measured with different types of detectors (RSKS and CD) was higher than 150%. The study suggests that the activity concentration of radon in caves, measured using track detectors, could not be influenced by the type of detector used if the microclimate factor is acknowledged. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. GC×GC measurements of C7-C11 aromatic and n-alkane hydrocarbons on Crete, in air from Eastern Europe during the MINOS campaign

    Directory of Open Access Journals (Sweden)

    X. Xu

    2003-01-01

    Full Text Available During the Mediterranean Intensive Oxidant Study (MINOS campaign in August 2001 gas-phase organic compounds were measured using comprehensive two-dimensional gas chromatography (GCxGC at the Finokalia ground station, Crete. In this paper, C7-C11 aromatic and n-alkane measurements are presented and interpreted. The mean mixing ratios of the hydrocarbons varied from 1±1 pptv (i-propylbenzene to 43±36 pptv (toluene. The observed mixing ratios showed strong day-to-day variations and generally higher levels during the first half of the campaign. Mean diel profiles showed maxima at local midnight and late morning, and minima in the early morning and evening. Results from analysis using a simplified box model suggest that both the chemical sink (i.e. reaction with OH and the variability of source strengths were the causes of the observed variations in hydrocarbon mixing ratios. The logarithms of hydrocarbon concentrations were negatively correlated with the OH concentrations integral over a day prior to the hydrocarbon measurements. Slopes of the regression lines derived from these correlations for different compounds are compared with literature rate constants for their reactions with OH. The slopes for most compounds agree reasonably well with the literature rate constants. A sequential reaction model has been applied to the interpretation of the relationship between ethylbenzene and two of its potential products, i.e. acetophenone and benzeneacetaldehyde. The model can explain the good correlation observed between [acetophenone]/[ethylbenzene] and [benzeneacetaldehyde]/[ethylbenzene]. The model results and field measurements suggest that the reactivity of benzeneacetaldehyde may lie between those of acetophenone and ethylbenzene and that the ratio between yields of acetophenone and benzeneacetaldehyde may be up to 28:1. Photochemical ages of trace gases sampled at Finokalia during the campaign are estimated using the sequential reaction model and

  16. Comparing i-Tree modeled ozone deposition with field measurements in a periurban Mediterranean forest

    Science.gov (United States)

    A. Morani; D. Nowak; S. Hirabayashi; G. Guidolotti; M. Medori; V. Muzzini; S. Fares; G. Scarascia Mugnozza; C. Calfapietra

    2014-01-01

    Ozone flux estimates from the i-Tree model were compared with ozone flux measurements using the Eddy Covariance technique in a periurban Mediterranean forest near Rome (Castelporziano). For the first time i-Tree model outputs were compared with field measurements in relation to dry deposition estimates. Results showed generally a...

  17. Fluctuations of the number of adsorbed micro/nanoparticles in sensors for measurement of particle concentration in air and liquid environments

    Directory of Open Access Journals (Sweden)

    Jokić Ivana

    2015-01-01

    Full Text Available A theoretical model of fluctuations of the number of adsorbed micro/nanoparticles in environmental sensors operating in air and liquids is presented, taking into account the effects of the mass transfer processes of the target particles in a sensor reaction chamber. The expressions for the total power of the corresponding adsorption-desorption noise, and for the corresponding signal-to-noise ratio are also derived. The presented analysis shows that the transfer processes can have a significant influence on the sensors limiting performance. The influence on both the fluctuations spectrum and the signal-to-noise ratio is estimated at different values of target particles concentration, functionalization sites surface density, and adsorption and desorption rate constants (the values are chosen from the ranges corresponding to real conditions. The analysis provides the guidelines for optimization of sensor design and operating conditions for the given target substance and sensor functionalization, in order to decrease the influence of the mass transfer, thus improving the ultimate performance (e.g. minimal detectable signal, signal-to-noise ratio of sensors for particle detection. The calculations we performed show that it is possible to increase the signal-to-noise ratio for as much as two orders of magnitude by using the optimization that eliminates the mass transfer influence. [Projekat Ministarstva nauke Republike Srbije, br. TR32008

  18. A thermal comparator sensor for measuring autogenous deformation in hardening Portland cement paste

    DEFF Research Database (Denmark)

    Østergaard, Thomas; Jensen, Ole Mejlhede

    2003-01-01

    This paper describes a simple and accurate experimental device specially developed to measure autogenous deformation in hardening cement-based materials. The measuring system consists of a so-called thermal comparator sensor and a modular thermostatically controlled system. The operating principle...... of the thermal comparator is based on thermal expansion of aluminium. A particular characteristic of the measuring system is the fixation of the thermal comparator sensor to the deforming specimen. The modular system ensures effective thermostatic control of the hydrating cement paste samples. The technique...

  19. A coaxially heated membrane introduction mass spectrometry interface for the rapid and sensitive on-line measurement of volatile and semi-volatile organic contaminants in air and water at parts-per-trillion levels.

    Science.gov (United States)

    Thompson, Alexander J; Creba, A Skye; Ferguson, Robyn M; Krogh, Erik T; Gill, Christopher G

    2006-01-01

    A coaxially heated membrane introduction mass spectrometry (MIMS) sampling interface is presented that demonstrates improved on-line performance for the direct measurement of semi-volatile organic compounds (SVOCs) in air and water samples at parts-per-trillion levels. The device is based on a polydimethylsiloxane (PDMS) capillary hollow fibre membrane (HFM) in a pneumatically assisted "flow-over" configuration that is resistively heated on the membrane interior via a coaxial nichrome wire, establishing a thermal gradient counter to the analyte concentration gradient. This arrangement allows for continuous and/or pulsed heating modes, affording excellent sensitivity for the on-line measurement of SVOCs while retaining sensitivity for volatile organic compounds (VOCs). In addition, the signal response time for SVOCs is reduced substantially over conventional "flow-over" MIMS interfaces. Separation and quantitation of analytes are achieved using quadrupole ion trap tandem mass spectrometry. Copyright (c) 2006 John Wiley & Sons, Ltd.

  20. A model based approach to reference-free straightness measurement at the Nanometer Comparator

    Science.gov (United States)

    Weichert, C.; Stavridis, M.; Walzel, M.; Elster, C.; Wiegmann, A.; Schulz, M.; Köning, R.; Flügge, J.; Tutsch, R.

    2009-06-01

    The Nanometer Comparator is the PTB reference length measuring machine for high precision calibrations of line scales and encoder systems. Up to now the Nanometer Comparator allows to measure the position of line structures in one dimension only. For high precision characterisations of masks, scales and incremental encoders, the measurement of the straightness of graduations is a requirement from emerging lithography techniques. Therefore the Nanometer Comparator will be equipped with an additional short range measurement system in the Y-direction, realized as a single path plane mirror interferometer and supposed to achieve sub-nm uncertainties. To compensate the topography of the Y-mirror, the Traceable Multi Sensor (TMS) method will be implemented to achieve a reference-free straightness measurement. Virtual experiments are used to estimate the lower accuracy limit and to determine the sensitive parameters. The virtual experiments contain the influence of the positioning devices, interferometer errors as well as non-perfect adjustment and fabrication of the machine geometry. The whole dynamic measurement process of the Nanometer Comparator including its influence on the TMS analysis, e.g. non-equally spaced measurement points, is simulated. We will present the results of these virtual experiments as well as the most relevant error sources for straightness measurement, incorporating the low uncertainties of the existing and planned measurement systems.

  1. The Relationship of Static Anthropometric Measurements to Lower Leg, Ankle, and Foot Injuries in Air Force Academy Cadets: A Prospective Longitudinal Study

    National Research Council Canada - National Science Library

    McMahon, Thomas

    2001-01-01

    The purpose of this prospective cohort study was to investigate the relationship between static anthropometric measures or demographical information and overuse injuries in the lower leg, ankle and foot...

  2. Excess use of coercive measures in psychiatry among migrants compared with native Danes

    DEFF Research Database (Denmark)

    Nørredam, Marie Louise; Garcia-Lopez, A; Keiding, N

    2010-01-01

    Norredam M, Garcia-Lopez A, Keiding N, Krasnik A. Excess use of coercive measures in psychiatry among migrants compared with native Danes.Objective: To investigate differences in risk of compulsory admission and other coercive measures in psychiatric emergencies among refugees and immigrants comp...

  3. Doppler ultrasound compared with strain gauge for measurement of systolic ankle blood pressure.

    Science.gov (United States)

    Joensen, J B; Juul, S; Abrahamsen, J; Henneberg, E W; Lindholt, Jes S

    2008-01-01

    This study assesses measurement variation in the measurement of ankle systolic blood pressure (ABP) when measured with Doppler ultrasound and with the strain gauge method. Ninety-seven patients were included. ABP was measured with Doppler ultrasound and with the strain gauge method. The methods were compared graphically by scatterplots and analyzed by paired t test, analysis of variance, and Pitman's paired variance ratio test. ABP was measured by strain gauge in all extremities, whereas no Doppler signal was obtainable in 7 limbs (4%). There was no systematic difference in measurements between the means of the two measurements. However, a substantial difference of more than 25 mm Hg was found in 15% of limbs and more than 20 mm Hg in 20%. In the majority of patients, measurements of ABP by Doppler ultrasound and the strain gauge method give similar results, but for a minority the discrepancy is substantial.

  4. A comparative study of linear measurements on facial skeleton with frontal and lateral cephalogram

    Directory of Open Access Journals (Sweden)

    Chandra Sekhar Gandikota

    2012-01-01

    Full Text Available Objective: To compare the accuracy of linear measurements on lateral and frontal cephalograms with gold standard skull measurements . Materials and Methods: Based on the specific criteria including reliable occlusion and condyles fitting in glenoid fossa, 15 dry human skulls were selected from a larger collection. Lateral and frontal cephalograms were taken of each skull by standardized methods. Steel ball bearings were used to identify the anatomic landmarks. Linear measurements in midsagittal plane were made on all three records. Intraclass correlation coefficients, Pearson′s correlation coefficient and regression constant were calculated to assess the records simultaneously. Results: The frontal cephalometric measurements showed high correlation to the direct skull measurements (Pearson′s coefficient 0.943measurements of the lateral cephalometric record are greater than the corresponding frontal cephalometric images. The overall findings of the present study showed that the frontal cephalometric measurements are closely related to the direct skull measures.

  5. Measures of satisfaction with care during labour and birth: a comparative review

    OpenAIRE

    Sawyer, Alexandra; Ayers, Susan; Abbott, Jane; Gyte, Gillian; Rabe, Heike; Duley, Leila

    2013-01-01

    Background\\ud Satisfaction is the one of the most frequently reported outcome measures for quality of care. Assessment of satisfaction with maternity services is crucial, and psychometrically sound measures are needed if this is to inform health practices. This paper comparatively reviews current measures of satisfaction with care during labour and birth.\\ud \\ud Methods\\ud A review of the literature was conducted. Studies were located through computerised databases and hand searching referenc...

  6. Prospective Comparative Analysis of 4 Different Intraocular Pressure Measurement Techniques and Their Effects on Pressure Readings.

    Science.gov (United States)

    Berk, Thomas A; Yang, Patrick T; Chan, Clara C

    2016-10-01

    To compare intraocular pressure (IOP) measurement using the Goldmann applanation tonometry (GAT) without fluorescein, with fluorescein strips, with fluorescein droplets, and IOP measurement with Tono-Pen Avia (TPA). This was a prospective comparative clinical analysis. It was performed in clinical practice. The study population consisted of 40 volunteer patients, 1 eye per patient. All patients who were 18 years and older having routine ophthalmological examination were eligible to participate. Active corneal abrasions and/or ulcers, previous glaucoma surgery, or prostheses interfering with GAT measurement were excluded. GAT IOP was measured first without fluorescein, then with fluorescein strip, then with fluorescein droplet, and finally with the TPA device. The main outcome measure was central corneal IOP. Mean±SD IOP measurements for GAT without fluorescein, with fluorescein strip, with fluorescein droplet, and for TPA groups were 12.65±3.01, 14.70±2.82, 15.78±2.64, and 16.33±3.08 mm Hg, respectively. Repeated-measures analysis of variance corrected with the Greenhouse-Geisser estimate ([Latin Small Letter Open E]=0.732) showed that measuring technique had a significant effect on IOP measurements (F2.20,85.59=34.66, P<0.001). The pairwise post hoc testing showed statistically significant mean differences (P≤0.001) between all techniques except when GAT with fluorescein droplet was compared with TPA (P=0.222). The Bland-Altman analyses showed 95% limits of agreement maximum potential discrepancies in measurement ranging from 5.89 mm Hg in the GAT with fluorescein strip versus droplet compared with 11.83 mm Hg in the GAT with fluorescein strip versus TPA comparison. IOP measurement technique significantly impacted the values obtained. The ophthalmologist should ensure consistent measurement technique to minimize variability when following patients.

  7. Satellite (Timed, Aura, Aqua) and In Situ (Meteorological Rockets, Balloons) Measurement Comparability

    Science.gov (United States)

    Schmidlin, F. J.; Goldberg, Richard A.; Feofilov, A.; Rose, R.

    2010-01-01

    Measurements using the inflatable falling sphere often are requested to provide density data in support of special sounding rocket launchings into the mesosphere and thermosphere. To insure density measurements within narrow time frames and close in space, the inflatable falling sphere is launched within minutes of the major test. Sphere measurements are reliable for the most part, however, availability of these rocket systems has become more difficult and, in fact, these instruments no longer are manufactured resulting in a reduction of the meager stockpile of instruments. Sphere measurements also are used to validate remotely measured temperatures and have the advantage of measuring small-scale atmospheric features. Even so, with the dearth of remaining falling spheres perhaps it is time to consider whether the remote measurements are mature enough to stand alone. Presented are two field studies, one in 2003 from Northern Sweden and one in 2010 from the vicinity of Kwajalein Atoll that compare temperature retrievals between satellite and in situ failing spheres. The major satellite instruments employed are SABER, MLS, and AIRS. The comparisons indicate that remotely measured temperatures mimic the sphere temperature measurements quite well. The data also confirm that satellite retrievals, while not always at the exact location required for individual studies, are adaptable enough and highly useful. Although the falling sphere will provide a measurement at a specific location and time, satellites only pass a given location daily or less often. This report reveals that averaged satellite measurements can provide temperatures and densities comparable to the falling sphere.

  8. Changes in air quality caused by reduced emission levels in Saxony-Anhalt. Results derived from a modern East German immission measuring system

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, U. [Saxony-Anhalt State Environmental Protection Agency, Magdeburg (Germany); Roemermann, D.; Begert, V. [Saxony-Anhalt Ministry of Environment, Magdeburg (Germany). Nature Conservation and Regional Planning

    1995-12-31

    Specific features and main fields of construction of a telemetric immission measuring system in the East German federal state of Saxony-Anhalt are shown as a result of a very rapid development in the last three years. Immission levels and resultant enormous changes in the recent years in conjunction with the drastically changed emission situation are analysed. (author)

  9. Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.

    Science.gov (United States)

    Li, Hui; Kayhanian, Masoud; Harvey, John T

    2013-03-30

    Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Transcutaneous oximetry measurements of the leg: comparing different measuring equipment and establishing values in healthy young adults.

    Science.gov (United States)

    Trinks, Tobias P; Blake, Denise F; Young, Derelle A; Thistlethwaite, Ken; Vangaveti, Venkat N

    2017-06-01

    Transcutaneous oximetry measurement (TCOM) is a non-invasive method of determining oxygen tension at the skin level using heated electrodes. To compare TCOM values generated by different machines and to establish lower limb TCOM values in a cohort of healthy individuals younger than 40 years of age. Sixteen healthy, non-smoking volunteers aged 18 to 39 years were recruited. TCOM was obtained at six locations on the lower leg and foot using three different Radiometer machines. Measurements were taken with subjects lying supine, breathing air. Except for one sensor site, there were no statistical differences in measurements obtained by the different TCOM machines. There was no statistical difference in measurements comparing left and right legs. Room air TCOM values for the different lower leg sites were (mean (SD) in mmHg): lateral leg 61.5 (9.2); lateral ankle 61.1 (9.7); medial ankle 59.1 (10.8); foot, first and second toe 63.4 (10.6); foot, fifth toe 59.9 (13.2) and plantar foot 74.1 (8.8). The overall mean TCOM value for the lower limb was 61 (10.8; 95% confidence intervals 60.05-62.0) mmHg. Lower-leg TCOM measurements using different Radiometer TCOM machines were comparable. Hypoxia has been defined as lower-leg TCOM values of less than 40 mmHg in non-diabetic patients and this is supported by our measurements. The majority (96.9%) of the lower leg TCOM values in healthy young adults are above the hypoxic threshold.

  11. Measure once, cut twice--adding patient-reported outcome measures to the electronic health record for comparative effectiveness research.

    Science.gov (United States)

    Wu, Albert W; Kharrazi, Hadi; Boulware, L Ebony; Snyder, Claire F

    2013-08-01

    This article presents the current state of patient-reported outcome measures and explains new opportunities for leveraging the recent adoption of electronic health records to expand the application of patient-reported outcomes in both clinical care and comparative effectiveness research. Historic developments of patient-reported outcome, electronic health record, and comparative effectiveness research are analyzed in two dimensions: patient centeredness and digitization. We pose the question, "What needs to be standardized around the collection of patient-reported outcomes in electronic health records for comparative effectiveness research?" We identified three converging trends: the progression of patient-reported outcomes toward greater patient centeredness and electronic adaptation; the evolution of electronic health records into personalized and fully digitized solutions; and the shift toward patient-oriented comparative effectiveness research. Related to this convergence, we propose an architecture for patient-reported outcome standardization that could serve as a first step toward a more comprehensive integration of patient-reported outcomes with electronic health record for both practice and research. The science of patient-reported outcome measurement has matured sufficiently to be integrated routinely into electronic health records and other electronic health solutions to collect data on an ongoing basis for clinical care and comparative effectiveness research. Further efforts and ideally coordinated efforts from various stakeholders are needed to refine the details of the proposed framework for standardization. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. COMPAR

    International Nuclear Information System (INIS)

    Kuefner, K.

    1976-01-01

    COMPAR works on FORTRAN arrays with four indices: A = A(i,j,k,l) where, for each fixed k 0 ,l 0 , only the 'plane' [A(i,j,k 0 ,l 0 ), i = 1, isub(max), j = 1, jsub(max)] is held in fast memory. Given two arrays A, B of this type COMPAR has the capability to 1) re-norm A and B ind different ways; 2) calculate the deviations epsilon defined as epsilon(i,j,k,l): =[A(i,j,k,l) - B(i,j,k,l)] / GEW(i,j,k,l) where GEW (i,j,k,l) may be chosen in three different ways; 3) calculate mean, standard deviation and maximum in the array epsilon (by several intermediate stages); 4) determine traverses in the array epsilon; 5) plot these traverses by a printer; 6) simplify plots of these traverses by the PLOTEASY-system by creating input data blocks for this system. The main application of COMPAR is given (so far) by the comparison of two- and three-dimensional multigroup neutron flux-fields. (orig.) [de

  13. Comparative use of different emission measurement approaches to determine methane emissions from a biogas plant.

    Science.gov (United States)

    Reinelt, Torsten; Delre, Antonio; Westerkamp, Tanja; Holmgren, Magnus A; Liebetrau, Jan; Scheutz, Charlotte

    2017-10-01

    A sustainable anaerobic biowaste treatment has to mitigate methane emissions from the entire biogas production chain, but the exact quantification of these emissions remains a challenge. This study presents a comparative measurement campaign carried out with on-site and ground-based remote sensing measurement approaches conducted by six measuring teams at a Swedish biowaste treatment plant. The measured emissions showed high variations, amongst others caused by different periods of measurement performance in connection with varying operational states of the plant. The overall methane emissions measured by ground-based remote sensing varied from 5 to 25kgh -1 (corresponding to a methane loss of 0.6-3.0% of upgraded methane produced), depending on operating conditions and the measurement method applied. Overall methane emissions measured by the on-site measuring approaches varied between 5 and 17kgh -1 (corresponding to a methane loss of 0.6 and 2.1%) from team to team, depending on the number of measured emission points, operational state during the measurements and the measurement method applied. Taking the operational conditions into account, the deviation between different approaches and teams could be explained, in that the two largest methane-emitting sources, contributing about 90% of the entire site's emissions, were found to be the open digestate storage tank and a pressure release valve on the compressor station. Copyright © 2017. Published by Elsevier Ltd.

  14. Measurements of 220Rn in air using a flow-through Lucas cell and multiple time analysis of recorded pulse events

    International Nuclear Information System (INIS)

    Falk, R.; Moere, H.; Nyblom, L.

    1992-01-01

    A multiple time analysis technique has successfully been applied for measurements of environmental levels of 220 Rn using a flow-through Lucas radon detector. The method is based on selective alpha counting of the short-lived nuclide 216 Pu. Owing to its short half-life (0.145 s), the alpha particle emitted at the decay of a 220 Rn atom will, within a fraction of a second, be followed by an alpha particle from the decay of 216 Po. By measuring the time interval between successive alpha counts followed by a multiple time analysis, the 216 Po activity and thereby the 220 Rn activity can be calculated. The method applied to a commercial instrument with a 160 ml Lucas cell as detector shows that a mean 220 Rn air concentration of less than 20 Bq.m -3 can easily be determined even if the 222 Rn air concentration is 10 times higher and varies. At lower 222 Rn levels a 220 Rn concentration less than 1 Bq.m -3 can be assessed using this technique. The method will be described together with some examples of its practical use. (author)

  15. UARS MILS O3 soundings compared with lidar measurements using the conservative coordinates reconstruction technique

    Science.gov (United States)

    Redaelli, G.; Lait, L. R.; Schoeberl, M.; Newman, P. A.; Visconti, G.; D'Altorio, A.; Masci, F.; Rizi, V.; Froidevaux, L.; Waters, J. W.

    1994-01-01

    A technique based on conservative properties of certain meteorological fields is used to compare ozone measurements from the Microwave Limb Sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) with soundings from a lidar system operated at midlatitudes by the University of L'Aquila, Italy. A few typical cases are analyzed in connection with the position of the vortex relative to the observing station, and it is shown that in general lidar observations taken within the vortex compare well with the UARS data, regardless of whether they are coincident with a satellite overpass. It is shown that such analysis may be useful for comparing measurements of the same quantity taken at different sites using different measurement techniques.

  16. Rotor equivalent wind speed for power curve measurementcomparative exercise for IEA Wind Annex 32

    DEFF Research Database (Denmark)

    Wagner, Rozenn; Cañadillas, B.; Clifton, A.

    2014-01-01

    A comparative exercise has been organised within the International Energy Agency (IEA) Wind Annex 32 in order to test the Rotor Equivalent Wind Speed (REWS) method under various conditions of wind shear and measurement techniques. Eight organisations from five countries participated in the exercise....... Each member of the group has derived both the power curve based on the wind speed at hub height and the power curve based on the REWS. This yielded results for different wind turbines, located in diverse types of terrain and where the wind speed profile was measured with different instruments (mast...... was the definition of the segment area used as weighting for the wind speeds measured at the various heights in the calculation of the REWS. This comparative exercise showed that the REWS method results in a significant difference compared to the standard method using the wind speed at hub height in conditions...

  17. Comparative study of radiometric and calorimetric methods for total hemispherical emissivity measurements

    Science.gov (United States)

    Monchau, Jean-Pierre; Hameury, Jacques; Ausset, Patrick; Hay, Bruno; Ibos, Laurent; Candau, Yves

    2017-11-01

    Accurate knowledge of infrared emissivity is important in applications such as surface temperature measurements by infrared thermography or thermal balance for building walls. A comparison of total hemispherical emissivity measurement was performed by two laboratories: the Laboratoire National de Métrologie et d'Essais (LNE) and the Centre d'Études et de Recherche en Thermique, Environnement et Systèmes (CERTES). Both laboratories performed emissivity measurements on four samples, chosen to cover a large range of emissivity values and angular reflectance behaviors. The samples were polished aluminum (highly specular, low emissivity), bulk PVC (slightly specular, high emissivity), sandblasted aluminum (diffuse surface, medium emissivity), and aluminum paint (slightly specular surface, medium emissivity). Results obtained using five measurement techniques were compared. LNE used a calorimetric method for direct total hemispherical emissivity measurement [1], an absolute reflectometric measurement method [2], and a relative reflectometric measurement method. CERTES used two total hemispherical directional reflectometric measurement methods [3, 4]. For indirect techniques by reflectance measurements, the total hemispherical emissivity values were calculated from directional hemispherical reflectance measurement results using spectral integration when required and directional to hemispherical extrapolation. Results were compared, taking into account measurement uncertainties; an added uncertainty was introduced to account for heterogeneity over the surfaces of the samples and between samples. All techniques gave large relative uncertainties for a low emissive and very specular material (polished aluminum), and results were quite scattered. All the indirect techniques by reflectance measurement gave results within ±0.01 for a high emissivity material. A commercial aluminum paint appears to be a good candidate for producing samples with medium level of emissivity

  18. Valid Outcome Measures in Care for Older People: Comparing the ASCOT and the ICECAP-O.

    Science.gov (United States)

    Hackert, Mariska Q N; Exel, Job van; Brouwer, Werner B F

    Limited health care budgets and population aging result in a need to compare care services on their benefits and costs. Because services for older people often aim to improve multiple life aspects, valid measures are needed to examine their benefits on individuals' health and well-being simultaneously. Two measures may meet this end: the Adult Social Care Outcomes Toolkit (ASCOT) and the ICEpop CAPability measure for Older people (ICECAP-O). To compare the validity of both measures, the ASCOT and the ICECAP-O. A sampling agency gathered cross-sectional data in May 2015. Using exploratory factor analysis, the underlying factor structure of the ASCOT and the ICECAP-O was examined for the first time. Convergent and discriminant validity in relation to health measures (five-level EuroQol five-dimensional questionnaire, EuroQol Visual Analogue Scale, Barthel Index, and Geriatric Depression Scale-15) and well-being measures (Older People's Quality of Life Questionnaire-13, Satisfaction with Life Scale, and Cantril's Ladder) were tested using Spearman rank correlations and variance analysis. The ASCOT and the ICECAP-O tapped into a shared factor, whereas both measures also loaded on two separate factors. The ASCOT and the ICECAP-O correlated highly with the health and well-being measures, but the correlation with the physical health measure Barthel Index was moderate. Both measures discriminated between subgroups of respondents. The ASCOT and the ICECAP-O seem promising measures to evaluate well-being among older people, whereby the ASCOT seems more specific to social care-related outcomes. The performance of both measures in other respondent groups and countries, and their relation to physical health, need to be further examined before their use in economic evaluations can be recommended. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  19. Evaluation of saving measurements and energetic efficiency in air-conditioning systems; Evaluacion de medidas de ahorro y eficiencia energetica en sistemas de climatizacion

    Energy Technology Data Exchange (ETDEWEB)

    Perez Lombard, L [Asociacion de Investigacion y Cooperacion de Andalucia (Spain); Ortiz, J [Building Research Establishment (United Kingdom); Riviere, P [Armines-ecole des mines de Paris (France)

    2006-04-15

    Buildings require an adequate air conditioning to offer workers a labor environment where there is thermal comfort. A study was performed in three different European places which count on several climates. The conclusion was the following: in order to analyze the energy efficiency in edifications it is fundamental the simulation tools use with the purpose of calculating the consumption and evaluating the saving measurements. [Spanish] Los edificios requieren de una climatizacion adecuada para que los que ahi operan puedan hacerlo dentro de un ambiente laboral donde exista el confort termico. Se llevo a cabo un estudio en tres lugares de Europa poseedores de diferentes climas y se concluyo que para poder analizar la eficiencia energetica de climatizacion en las edificaciones es imprescindible el uso de herramientas de simulacion con el proposito de calcular el consumo y evaluar las medidas de ahorro.

  20. Comparing measurement error correction methods for rate-of-change exposure variables in survival analysis.

    Science.gov (United States)

    Veronesi, Giovanni; Ferrario, Marco M; Chambless, Lloyd E

    2013-12-01

    In this article we focus on comparing measurement error correction methods for rate-of-change exposure variables in survival analysis, when longitudinal data are observed prior to the follow-up time. Motivational examples include the analysis of the association between changes in cardiovascular risk factors and subsequent onset of coronary events. We derive a measurement error model for the rate of change, estimated through subject-specific linear regression, assuming an additive measurement error model for the time-specific measurements. The rate of change is then included as a time-invariant variable in a Cox proportional hazards model, adjusting for the first time-specific measurement (baseline) and an error-free covariate. In a simulation study, we compared bias, standard deviation and mean squared error (MSE) for the regression calibration (RC) and the simulation-extrapolation (SIMEX) estimators. Our findings indicate that when the amount of measurement error is substantial, RC should be the preferred method, since it has smaller MSE for estimating the coefficients of the rate of change and of the variable measured without error. However, when the amount of measurement error is small, the choice of the method should take into account the event rate in the population and the effect size to be estimated. An application to an observational study, as well as examples of published studies where our model could have been applied, are also provided.

  1. Two- and three-dimensional CT measurements of urinary calculi length and width: a comparative study.

    Science.gov (United States)

    Lidén, Mats; Thunberg, Per; Broxvall, Mathias; Geijer, Håkan

    2015-04-01

    The standard imaging procedure for a patient presenting with renal colic is unenhanced computed tomography (CT). The CT measured size has a close correlation to the estimated prognosis for spontaneous passage of a ureteral calculus. Size estimations of urinary calculi in CT images are still based on two-dimensional (2D) reformats. To develop and validate a calculus oriented three-dimensional (3D) method for measuring the length and width of urinary calculi and to compare the calculus oriented measurements of the length and width with corresponding 2D measurements obtained in axial and coronal reformats. Fifty unenhanced CT examinations demonstrating urinary calculi were included. A 3D symmetric segmentation algorithm was validated against reader size estimations. The calculus oriented size from the segmentation was then compared to the estimated size in axial and coronal 2D reformats. The validation showed 0.1 ± 0.7 mm agreement against reference measure. There was a 0.4 mm median bias for 3D estimated calculus length compared to 2D (P calculus in axial and coronal reformats becomes underestimated compared to 3D if its orientation is not aligned to the image planes. Future studies aiming to correlate calculus size with patient outcome should use a calculus oriented size estimation. © The Foundation Acta Radiologica 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  2. Structural linear measurements in the newborn brain: accuracy of cranial ultrasound compared to MRI

    International Nuclear Information System (INIS)

    Leijser, Lara M.; Srinivasan, Latha; Cowan, Frances M.; Rutherford, Mary A.; Counsell, Serena J.; Allsop, Joanna M.

    2007-01-01

    Structural size in the neonatal brain is of clinical importance. Cranial ultrasonography (cUS) is the primary method used for evaluating the neonatal brain and it is important to know whether linear measurements made using this technique are accurate. To compare linear measurements of different cerebral structures made from neonatal cUS and contemporaneous MRI. Preterm and term infants studies with cUS and MRI on the same day were studied. Linear measurements made using both techniques from many cerebral structures were compared using a paired t-test. A total of 44 sets of scans from 26 preterm and 8 term infants were assessed. Small but significant differences between the cUS and MRI measurements (P<0.05) were found for the ventricular index, the posterior horn depth of the lateral ventricle, the extracerebral space and interhemispheric fissure, and the cortex of the cingulate gyrus. No significant differences were found for any other measurements. Linear measurements from cUS are accurate for most neonatal cerebral structures. Significant differences compared to MRI were found for a few structures, but only for the cortex were the absolute differences marked and possibly of clinical importance. (orig.)

  3. Structural linear measurements in the newborn brain: accuracy of cranial ultrasound compared to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Leijser, Lara M. [Hammersmith Hospital, Imperial College, Department of Paediatrics, London (United Kingdom); Srinivasan, Latha; Cowan, Frances M. [Hammersmith Hospital, Imperial College, Department of Paediatrics, London (United Kingdom); Hammersmith Hospital, Imperial College, Department of Imaging Sciences, London (United Kingdom); Rutherford, Mary A.; Counsell, Serena J.; Allsop, Joanna M. [Hammersmith Hospital, Imperial College, Department of Imaging Sciences, London (United Kingdom)

    2007-07-15

    Structural size in the neonatal brain is of clinical importance. Cranial ultrasonography (cUS) is the primary method used for evaluating the neonatal brain and it is important to know whether linear measurements made using this technique are accurate. To compare linear measurements of different cerebral structures made from neonatal cUS and contemporaneous MRI. Preterm and term infants studies with cUS and MRI on the same day were studied. Linear measurements made using both techniques from many cerebral structures were compared using a paired t-test. A total of 44 sets of scans from 26 preterm and 8 term infants were assessed. Small but significant differences between the cUS and MRI measurements (P<0.05) were found for the ventricular index, the posterior horn depth of the lateral ventricle, the extracerebral space and interhemispheric fissure, and the cortex of the cingulate gyrus. No significant differences were found for any other measurements. Linear measurements from cUS are accurate for most neonatal cerebral structures. Significant differences compared to MRI were found for a few structures, but only for the cortex were the absolute differences marked and possibly of clinical importance. (orig.)

  4. [Comparative measurement of urine specific gravity: reagent strips, refractometry and hydrometry].

    Science.gov (United States)

    Costa, Christian Elías; Bettendorff, Carolina; Bupo, Sol; Ayuso, Sandra; Vallejo, Graciela

    2010-06-01

    The urine specific gravity is commonly used in clinical practice to measure the renal concentration/dilution ability. Measurement can be performed by three methods: hydrometry, refractometry and reagent strips. To assess the accuracy of different methods to measure urine specific gravity. We analyzed 156 consecutive urine samples of pediatric patients during April and May 2007. Urine specific gravity was measured by hydrometry (UD), refractometry (RE) and reagent strips (TR), simultaneously. Urine osmolarity was considered as the gold standard and was measured by freezing point depression. Correlation between different methods was calculated by simple linear regression. A positive and acceptable correlation was found with osmolarity for the RE as for the UD (r= 0.81 and r= 0.86, respectively). The reagent strips presented low correlation (r= 0.46). Also, we found good correlation between measurements obtained by UD and RE (r= 0.89). Measurements obtained by TR, however, had bad correlation when compared to UD (r= 0.46). Higher values of specific gravity were observed when measured with RE with respect to UD. Reagent strips are not reliable for measuring urine specific gravity and should not be used as an usual test. However, hydrometry and refractometry are acceptable alternatives for measuring urine specific gravity, as long as the same method is used for follow-up.

  5. Controlling Air Traffic (Simulated) in the Presence of Automation (CATS PAu) 1995: A Study of Measurement Techniques for Situation Awareness in Air Traffic Control

    Science.gov (United States)

    French, Jennifer R.

    1995-01-01

    As automated systems proliferate in aviation systems, human operators are taking on less and less of an active role in the jobs they once performed, often reducing what should be important jobs to tasks barely more complex than monitoring machines. When operators are forced into these roles, they risk slipping into hazardous states of awareness, which can lead to reduced skills, lack of vigilance, and the inability to react quickly and competently when there is a machine failure. Using Air Traffic Control (ATC) as a model, the present study developed tools for conducting tests focusing on levels of automation as they relate to situation awareness. Subjects participated in a two-and-a-half hour experiment that consisted of a training period followed by a simulation of air traffic control similar to the system presently used by the FAA, then an additional simulation employing automated assistance. Through an iterative design process utilizing numerous revisions and three experimental sessions, several measures for situational awareness in a simulated Air Traffic Control System were developed and are prepared for use in future experiments.

  6. A comparative study of electromagnetic compatibility (EMC) analytical predictions and measurements

    Science.gov (United States)

    Clough, I. D.; Boud, W. E.

    1981-03-01

    Predictions by the specification and EMC analysis program (SEMCAP) used in the design of communication satellites to analyze and control EMC of electronic subsystems and wiring are compared with OTS, MAROTS and Meteosat data. The SEMCAP values are also checked against measurements on an experimental model of cable-coupled interference. A simple system handbook is provided. For a configuration of generators, receptors and wires, SEMCAP agrees reasonably well with measurements. The bundle shielding effect (of wires in the bundle other than those constituting the hard wire connections studied) introduces discrepencies. If this effect is allowed for in modelling, agreement with measurements is good.

  7. Alfven waves in the auroral ionosphere: A numerical model compared with measurements

    International Nuclear Information System (INIS)

    Knudsen, D.J.; Kelley, M.C.; Vickrey, J.F.

    1992-01-01

    The authors solve a linear numerical model of Alfven waves reflecting from the high-latitude ionosphere, both to better understanding the role of the ionosphere in the magnetosphere/ionosphere coupling process and to compare model results with in situ measurements. They use the model to compute the frequency-dependent amplitude and phase relations between the meridional electric and the zonal magnetic fields due to Alfven waves. These relations are compared with measurements taken by an auroral sounding rocket flow in the morningside oval and by the HILAT satellite traversing the oval at local noon. The sounding rocket's trajectory was mostly parallel to the auroral oval, and is measured enhanced fluctuating field energy in regions of electron precipitation. The rocket-measured phase data are in excellent agreement with the Alfven wave model, and the relation between the modeled and the measured by HILAT are related by the height-integrated Pedersen conductivity Σ p , indicating that the measured field fluctuations were due mainly to structured field-aligned current systems. A reason for the relative lack of Alfven wave energy in the HILAT measurements could be the fact that the satellite traveled mostly perpendicular to the oval and therefore quickly traversed narrow regions of electron precipitation and associated wave activity

  8. Comparing Evapotranspiration Rates Estimated from Atmospheric Flux and TDR Soil Moisture Measurements

    DEFF Research Database (Denmark)

    Schelde, Kirsten; Ringgaard, Rasmus; Herbst, Mathias

    2011-01-01

    Measurements of water vapor fluxes using eddy covariance (EC) and measurements of root zone soil moisture depletion using time domain reflectometry (TDR) represent two independent approaches to estimating evapotranspiration. This study investigated the possibility of using TDR to provide a lower...... limit estimate (disregarding dew evaporation) of evapotranspiration on dry days. During a period of 7 wk, the two independent measuring techniques were applied in a barley (Hordeum vulgare L.) field, and six dry periods were identified. Measurements of daily root zone soil moisture depletion were...... compared with daily estimates of water vapor loss. During the first dry periods, agreement between the two approaches was good, with average daily deviation between estimates below 1.0 mm d-1 Toward the end of the measurement period, the estimates of the two techniques tended to deviate due to different...

  9. A comparative study of linear measurements of facial skeleton using computed tomography and traditional cephalometry

    Directory of Open Access Journals (Sweden)

    Naveen Rayapudi

    2013-01-01

    Full Text Available Background: Radiographic imaging is an important adjunct in the assessment of skeletal and dental relationships for the orthodontic patient. Imaging is one of the most ubiquitous tools used by orthodontists to measure and record the size and form of craniofacial structures. Materials and Methods: The objectives of the study were to compare the measurements from human skulls and their images from cephalometric radiographs and computed tomography (CT scanograms in order to gauge the potential use of CT in routine clinical practice. Based on the specific criteria including stable occlusion and condyles fitting stably in glenoid fossa, 15 dry human skulls were selected. Lateral, posteroanterior cephalograms, and CT scout views were taken of each skull by standardized methods. Linear measurements were made on all three records. Intraclass correlation coefficients, Pearson′s correlation coefficient and regression constant were calculated to assess the records. Results: The linear measurements of the cephalometric record are greater than CT measurements on scout images. In vertical plane, the CT projections are more coinciding with the direct skull measurements. In sagittal and transverse planes, the cephalometric measurements were more correlating with the direct skull measurements. Conclusions: The cephalograms and CT scanograms differed in accuracy of linear measurements, because of variation in the location and size of an object, within the imaged 3D structure of both records.

  10. Comparative Study of the Knowledge of Metric Units of Measure and Their Application

    Science.gov (United States)

    Henry, Loren L.; Rowsey, Robert E.

    1978-01-01

    Compares the performance of three groups of students on two instruments developed to measure an understanding of: (1) metric relationships and (2) metric applications. It is concluded that participants are able to perform paper-pencil computation with metric units without being able to apply them. (HM)

  11. Measuring and Comparing Academic Language Development and Conceptual Understanding via Science Notebooks

    Science.gov (United States)

    Huerta, Margarita; Tong, Fuhui; Irby, Beverly J.; Lara-Alecio, Rafael

    2016-01-01

    The authors of this quantitative study measured and compared the academic language development and conceptual understanding of fifth-grade economically disadvantaged English language learners (ELL), former ELLs, and native English-speaking (ES) students as reflected in their science notebook scores. Using an instrument they developed, the authors…

  12. Does Occupational Mobility Influence Health among Working Women? Comparing Objective and Subjective Measures of Work Trajectories

    Science.gov (United States)

    Wilkinson, Lindsay R.; Shippee, Tetyana P.; Ferraro, Kenneth F.

    2012-01-01

    Occupational mobility is highly valued in American society, but is it consequential to women's health? Previous studies have yielded inconsistent results, but most measured occupational mobility by identifying transitions across occupational categories. Drawing from cumulative inequality theory, this study (1) compares objective and subjective…

  13. Revealed Comparative Advantage and the Alternatives as Measures of International Specialization

    DEFF Research Database (Denmark)

    Laursen, Keld

    2015-01-01

    discussion focuses on the properties of RSCA and empirical evidence, based on the Jarque-Bera test for normality of the regression error terms, using both the RCA and RSCA indices. We compare RSCA to other measures of international trade specialization including the Michaely index, the Contribution to Trade...

  14. The Efficiency of Higher Education Institutions in England Revisited: Comparing Alternative Measures

    Science.gov (United States)

    Johnes, Geraint; Tone, Kaoru

    2017-01-01

    Data envelopment analysis (DEA) has often been used to evaluate efficiency in the context of higher education institutions. Yet there are numerous alternative non-parametric measures of efficiency available. This paper compares efficiency scores obtained for institutions of higher education in England, 2013-2014, using three different methods: the…

  15. Measuring Person-Centered Care: A Critical Comparative Review of Published Tools

    Science.gov (United States)

    Edvardsson, David; Innes, Anthea

    2010-01-01

    Purpose of the study: To present a critical comparative review of published tools measuring the person-centeredness of care for older people and people with dementia. Design and Methods: Included tools were identified by searches of PubMed, Cinahl, the Bradford Dementia Group database, and authors' files. The terms "Person-centered,"…

  16. Comparative use of different emission measurement approaches to determine methane emissions from a biogas plant

    DEFF Research Database (Denmark)

    Reinelt, Torsten; Delre, Antonio; Westerkamp, Tanja

    2017-01-01

    A sustainable anaerobic biowaste treatment has to mitigate methane emissions from the entire biogas production chain, but the exact quantification of these emissions remains a challenge. This study presents a comparative measurement campaign carried out with on-site and ground-based remote sensin...

  17. Internationally Comparable Measures of Occupational Status for the 1988 International Standard Classification of Occupations

    NARCIS (Netherlands)

    Ganzeboom, H.B.G.; Treiman, D.J.

    1996-01-01

    This paper provides operational procedures for coding internationally comparable measures of occupational status from the recently published International Standard Classification of Occupation 1988 (ISCO88) of the International Labor Office (ILO, 1990). We first discuss the nature of the ISCO88

  18. Comparing Measures of General and Abdominal Adiposity as Predictors of Blood Pressure in College Students

    Science.gov (United States)

    Abshire, Demetrius A.; Mudd-Martin, Gia; Moser, Debra K.; Lennie, Terry A.

    2018-01-01

    Objective: To compare anthropometric measures of body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), and sagittal abdominal diameter (SAD) as predictors of blood pressure in college students. Participants: Students (N = 116) were recruited from November 2012 to May 2014 at an urban university and rural community…

  19. Comparing Derived and Actual Upwelling Longwave Measurements at the CERES Ocean Validation Experiment (COVE)

    Science.gov (United States)

    Fabbri, B. E.; Schuster, G. L.; Denn, F. M.; Arduini, R. F.; Madigan, J. J.

    2017-12-01

    One of the parameters measured from the Clouds and the Earth's Radiant Energy System (CERES) satellite is Earth emitted or longwave (LW) radiation. One validation site to compare this quantity is the CERES Ocean Validation Experiment (COVE), located at Chesapeake Light Station, approximately 25 kilometers east of Virginia Beach, Virginia (coordinates: 36.90N, 75.71W). However, the upwelling measurement is complicated due to the Light Station tower being in the LW instruments field of view. A negative outcome of the tower being in the field of view is a tower radiating effect, especially noticeable on clear, sunny days. During these days, the tower tends to heat up and radiate extra heat energy that is measured by the LW instrument. To understand the extent of the problem, we derive upwelling longwave measurements at the surface using sea surface temperature, air temperature, and dewpoint to compare with the actual longwave measurement made with an Eppley Laboratory pyrgeometer. The data used in this study is over a four-year period (2009-2012). One result using only nighttime data (range: 15.0 =solar insolation creating the tower radiating effect. Other results comparing the diurnal scope are analyzed and presented.

  20. SQUID based cryogenic current comparator for measurements of the dark current of superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Vodel, W.; Nietzsche, S.; Neubert, R.; Nawrodt, R. [Friedrich Schiller Univ. Jena (Germany); Peters, A. [GSI Darmstadt (Germany); Knaack, K.; Wendt, M.; Wittenburg, K. [DESY Hamburg (Germany)

    2005-07-01

    The linear accelerator technology, based on super-conducting L-band (1.3 GHz) is currently under study at DESY (Hamburg, Germany). The two 10 km long main Linacs will be equipped with a total of nearly 20.000 cavities. The dark current due to the emission of electrons in these high gradient field super-conducting cavities is an unwanted particle source. A newly high performance SQUID based measurement system for detecting dark currents is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the pA range with a measurement bandwidth of up to 70 kHz. The use of a cryogenic current comparator as dark current sensor has some important advantages: -) the measurement of the absolute value of the dark current, -) the non-dependence on the electron trajectories, -) the accurate absolute calibration with an additional wire loop, and -) extremely high resolution.

  1. Measurements of Corneal Thickness in Eyes with Pseudoexfoliation Syndrome: Comparative Study of Different Image Processing Protocols

    Directory of Open Access Journals (Sweden)

    Katarzyna Krysik

    2017-01-01

    Full Text Available Purpose. Comparative analysis of central and peripheral corneal thickness in PEX patients using three different imaging systems: Pentacam-Scheimpflug device, time-domain optical coherence tomography (OCT Visante, and swept-source OCT Casia. Materials and Methods. 128 eyes of 80 patients with diagnosed PEX were examined and compared with 112 normal, non-PEX eyes of 72 cataract patients. The study parameters included 5 measured zones: central and 4 peripheral (superior, inferior, nasal, and temporal. Results. The mean CCT in eyes with PEX syndrome measured with all three instruments was thicker than that in normal eyes. Corneal thickness measurements in the PEX group were statistically significantly different between Pentacam and OCT Casia: central corneal thickness (p=0.04, inferior corneal zone (p=0.01, and nasal and temporal corneal zones (p<0.01. Between Pentacam and OCT Visante inferior, nasal and temporal corneal zones were statistically significantly different (p<0.01. Between OCT Casia and OCT Visante, there were no statistically significant differences in measured parameters values. Conclusion. The central corneal thickness in eyes with PEX syndrome measured with three different independent methods is higher than that in the non-PEX group, and despite variable peripheral corneal thickness, this one parameter is still crucial in intraocular pressure measurements.

  2. Continuous versus bolus thermodilution cardiac output measurements--a comparative study.

    Science.gov (United States)

    Mihaljevic, T; von Segesser, L K; Tönz, M; Leskosek, B; Seifert, B; Jenni, R; Turina, M

    1995-05-01

    To compare the methods for continuous and bolus thermodilution cardiac output measurements. In vivo and in vitro experimental studies. Surgical research division in a university hospital. Eight calves and flow bench model. Data were collected in vivo from eight calves instrumented with pulmonary artery catheters, which allowed both continuous and bolus thermodilution measurements. The pulmonary artery catheter was placed through the external jugular vein. All in vitro measurements were performed using a flow bench model. A total of 232 bolus and continuous thermodilution measurements were analysed in vivo to determine the degree of agreement between the two methods. The absolute measurement bias was 0.14 L/min with 95% confidence limits ranging from -0.83 to 1.15 L/min. In vitro analysis of 576 measurements at six different temperature points (range 31 degrees to 41 degrees C), using clinically relevant flows (2 to 9 L/min), showed overestimation of flow values using continuous and bolus thermodilution methods. However, the continuous method showed better accuracy by a lower degree of overestimation. Systematic error was 9.7 +/- 8.4 (SD) % for continuous and 11.1 +/- 6.3% for the bolus method (p thermal filament of the pulmonary catheter impaired the accuracy of continuous measurement without affecting results from bolus measurements (systematic error -26.8 +/- 8.2% for continuous and -5.2 +/- 4.1% for bolus thermodilution). Continuous thermodilution cardiac output measurement provided higher accuracy and greater resistance to thermal noise than standard bolus measurements. The correct placement of the catheter is essential for precise measurements.

  3. Differences in displayed pump flow compared to measured flow under varying conditions during simulated cardiopulmonary bypass.

    LENUS (Irish Health Repository)

    Hargrove, M

    2008-07-01

    Errors in blood flow delivery due to shunting have been reported to reduce flow by, potentially, up to 40-83% during cardiopulmonary bypass. The standard roller-pump measures revolutions per minute and a calibration factor for different tubing sizes calculates and displays flow accordingly. We compared displayed roller-pump flow with ultrasonically measured flow to ascertain if measured flow correlated with the heart-lung pump flow reading. Comparison of flows was measured under varying conditions of pump run duration, temperature, viscosity, varying arterial\\/venous loops, occlusiveness, outlet pressure, use of silicone or polyvinyl chloride (PVC) in the roller race, different tubing diameters, and use of a venous vacuum-drainage device.

  4. A SOFTWARE TOOL TO COMPARE MEASURED AND SIMULATED BUILDING ENERGY PERFORMANCE DATA

    Energy Technology Data Exchange (ETDEWEB)

    Maile, Tobias; Bazjanac, Vladimir; O' Donnell, James; Garr, Matthew

    2011-11-01

    Building energy performance is often inadequate when compared to design goals. To link design goals to actual operation one can compare measured with simulated energy performance data. Our previously developed comparison approach is the Energy Performance Comparison Methodology (EPCM), which enables the identification of performance problems based on a comparison of measured and simulated performance data. In context of this method, we developed a software tool that provides graphing and data processing capabilities of the two performance data sets. The software tool called SEE IT (Stanford Energy Efficiency Information Tool) eliminates the need for manual generation of data plots and data reformatting. SEE IT makes the generation of time series, scatter and carpet plots independent of the source of data (measured or simulated) and provides a valuable tool for comparing measurements with simulation results. SEE IT also allows assigning data points on a predefined building object hierarchy and supports different versions of simulated performance data. This paper briefly introduces the EPCM, describes the SEE IT tool and illustrates its use in the context of a building case study.

  5. Comparability and repeatability of three commonly used methods for measuring endurance capacity.

    Science.gov (United States)

    Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

    2018-02-19

    Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.

  6. Compared performance of penetrometers and effect of soil water content on penetration resistance measurements

    Directory of Open Access Journals (Sweden)

    Edison Aparecido Mome Filho

    2014-06-01

    Full Text Available Modern agriculture techniques have a great impact on crops and soil quality, especially by the increased machinery traffic and weight. Several devices have been developed for determining soil properties in the field, aimed at managing compacted areas. Penetrometry is a widely used technique; however, there are several types of penetrometers, which have different action modes that can affect the soil resistance measurement. The objective of this study was to compare the functionality of two penetrometry methods (manual and automated mode in the field identification of compacted, highly mechanized sugarcane areas, considering the influence of soil water volumetric content (θ on soil penetration resistance (PR. Three sugarcane fields on a Rhodic Eutrudrox were chosen, under a sequence of harvest systems: one manual harvest (1ManH, one mechanized harvest (1MH and three mechanized harvests (3MH. The different degrees of mechanization were associated to cumulative compaction processes. An electronic penetrometer was used on PR measurements, so that the rod was introduced into the soil by hand (Manual and by an electromechanical motor (Auto. The θ was measured in the field with a soil moisture sensor. Results showed an effect of θ on PR measurements and that regression models must be used to correct data before comparing harvesting systems. The rod introduction modes resulted in different mean PR values, where the "Manual" overestimated PR compared to the "Auto" mode at low θ.

  7. Comparing the reliability of a trigonometric technique to goniometry and inclinometry in measuring ankle dorsiflexion.

    Science.gov (United States)

    Sidaway, Ben; Euloth, Tracey; Caron, Heather; Piskura, Matthew; Clancy, Jessica; Aide, Alyson

    2012-07-01

    The purpose of this study was to compare the reliability of three previously used techniques for the measurement of ankle dorsiflexion ROM, open-chained goniometry, closed-chained goniometry, and inclinometry, to a novel trigonometric technique. Twenty-one physiotherapy students used four techniques (open-chained goniometry, closed-chained goniometry, inclinometry, and trigonometry) to assess dorsiflexion range of motion in 24 healthy volunteers. All student raters underwent training to establish competence in the four techniques. Raters then measured dorsiflexion with a randomly assigned measuring technique four times over two sessions, one week apart. Data were analyzed using a technique by session analysis of variance, technique measurement variability being the primary index of reliability. Comparisons were also made between the measurements derived from the four techniques and those obtained from a computerized video analysis system. Analysis of the rater measurement variability around the technique means revealed significant differences between techniques with the least variation being found in the trigonometric technique. Significant differences were also found between the technique means but no differences between sessions were evident. The trigonometric technique produced mean ROMs closest in value to those derived from computer analysis. Application of the trigonometric technique resulted in the least variability in measurement across raters and consequently should be considered for use when changes in dorsiflexion ROM need to be reliably assessed. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Comparing ecosystem and soil respiration: Review and key challenges of tower-based and soil measurements

    Energy Technology Data Exchange (ETDEWEB)

    Barba, Josep; Cueva, Alejandro; Bahn, Michael; Barron-Gafford, Greg A.; Bond-Lamberty, Benjamin; Hanson, Paul J.; Jaimes, Aline; Kulmala, Liisa; Pumpanen, Jukka; Scott, Russell L.; Wohlfahrt, Georg; Vargas, Rodrigo

    2018-02-01

    The net ecosystem exchange (NEE) is the difference between ecosystem CO2 assimilation and CO2 losses to the atmosphere. Ecosystem respiration (Reco), the efflux of CO2 from the ecosystem to the atmosphere, includes the soil-to-atmosphere carbon flux (i.e., soil respiration; Rsoil) and aboveground plant respiration. Therefore, Rsoil is a fraction of Reco and by definition has to be smaller than Reco at annual, seasonal and daily scales. However, several studies estimating Reco with the eddy covariance technique and measuring Rsoil within the footprint of the tower have reported higher Rsoil than Reco at different time scales. Here, we compare four different and contrasting ecosystems (from forest to grasslands, and from boreal to semiarid) to study whether, and under what conditions, measurements of Reco are lower than Rsoil. In general, both fluxes showed similar temporal patterns, but Reco was not consistently higher than Rsoil from daily to annual scales across sites. We identified several issues that apply for measuring NEE and measuring/upscaling Rsoil that could result in an underestimation of Reco and/or an overestimation of Rsoil. These issues are discussed based on (a) nighttime measurements of NEE, (b) Rsoil measurements, and (c) the interpretation of the functional relationships of these fluxes with temperature (i.e., Q10). We highlight that there is still a need for better integration of Rsoil with eddy covariance measurements to address challenges related to spatial and temporal variability of Reco and Rsoil.

  9. Comparative research on the methods for measuring the mode deflection angle of cylindrical resonator gyroscope

    Science.gov (United States)

    Wang, Kai; Fan, Zhenfang; Wang, Dongya; Wang, Yanyan; Pan, Yao; Qu, Tianliang; Xu, Guangming

    2016-10-01

    The existence of mode deflection angle in the cylindrical resonator gyroscope (CRG) leads to the signal drift on the detecting nodes of the gyro vibration and significantly decreases the performance of the CRG. Measuring the mode deflection angle efficiently is the foundation of tuning for the imperfect cylindrical shell resonator. In this paper, an optical method based on the measuring gyroscopic resonator's vibration amplitude with the laser Doppler vibrometer and an electrical method based on measuring the output voltage of the electrodes on the resonator are both presented to measure the mode deflection angle. Comparative experiments were implemented to verify the methodology and the results show that both of the two methods could recognize the mode deflection angle efficiently. The precision of the optical method relies on the number and position of testing points distributed on the resonator. The electrical method with simple circuit shows high accuracy of measuring in a less time compared to the optical method and its error source arises from the influence of circuit noise as well as the inconsistent distribution of the piezoelectric electrodes.

  10. Accuracy of plantar electrodes compared with hand and foot electrodes in fat-free-mass measurement.

    Science.gov (United States)

    Jaffrin, Michel Y; Bousbiat, Sana

    2014-01-01

    This paper investigates the measurement of fat-free mass (FFM) by bioimpedance using foot-to-foot impedancemeters (FFI) with plantar electrodes measuring the foot-to-foot resistance R34 and hand-to-foot medical impedancemeters. FFM measurements were compared with corresponding data using Dual X-ray absorptiometry (DXA). Equations giving FFM were established using linear multiple regression on DXA data in a first group of 170 subjects. For validation, these equations were used on a second group of 86 subjects, and FFM were compared with DXA data; no significant difference was observed. The same protocol was repeated, but using electrodes on the right hand and foot in standing position to measure the hand to-foot resistance R13. Mean differences with DXA were higher for R13 than for R34. Effect of electrode size and feet position on resistance was also investigated. R34 decreased when electrode area increased or if feet were moved forward. It decreased if feet were moved backward. A proper configuration of contact electrodes can improve measurement accuracy and reproducibility of FFI.

  11. Quality-of-life scores compared to objective measures of swallowing after oropharyngeal chemoradiation.

    Science.gov (United States)

    Kendall, Katherine A; Kosek, Steven R; Tanner, Kristine

    2014-03-01

    To compare objective measures of swallowing function with patient reports of swallowing-related quality of life 1 year after treatment of oropharyngeal cancer with chemoradiation therapy. Patients seen for follow-up at least 1 year after treatment of oropharyngeal carcinoma with chemoradiation therapy were sequentially approached and asked to participate in the study. Maximum pharyngeal constriction, hyoid elevation, upper esophageal sphincter opening size, and bolus pharyngeal transit time were measured from modified barium swallowing studies in a group of 31 patients at least 1 year after chemoradiation therapy for the treatment of oropharyngeal carcinoma. Measures were made for a liquid 1-mL, 3-mL, and 20-mL bolus. Objective measure results were compared to scores from the MD Anderson Dysphagia Inventory and The University of Washington Swallowing Quality of Life Questionnaire results from the same patients. No strong correlation was identified between any of the objective measures of swallowing physiology and quality-of-life scores. Patient perception of the impact of swallowing function on quality of life does not correlate well with actual physiologic functioning. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Comparing Numbers of Drinks: College Students' Reports From Retrospective Summary, Followback, and Prospective Daily Diary Measures*

    Science.gov (United States)

    Patrick, Megan E.; Lee, Christine M.

    2010-01-01

    Objective: Retrospective summary, followback (retrospective diaries), and prospective daily diary measures of alcohol use among college students were compared across 29 days. Method: Participants were college students (n = 176; 60.2% female). Similarities in the three web-based reporting methods and both between-persons (i.e., gender, past drinking behavior, fraternity/sorority affiliation, average drinking behavior during the study period) and within-person (i.e., daily number of drinks, weekend days, Halloween, and week of study) predictors of concordance between reports of followback and prospective diaries were analyzed. Results: On prospective diaries, students reported a greater number of maximum drinks (compared with followback only) and a greater number of heavy drinking days in the past 2 weeks (compared with both followback and retrospective summary measures). In followback compared with prospective diaries, students tended to provide inflated accounts of their drinking behavior when reporting about occasions with greater typical drinking (i.e., weekends, Halloween) and deflated accounts of their drinking on their own heavier drinking days, especially if they were affiliated with a fraternity/sorority. Women and students who drank more on average across study days tended to provide deflated estimates of their day-to-day drinking in followback compared with prospective diary. Conclusions: Understanding the concordance and discordance in self-reported alcohol use is an important area for continued research efforts. PMID:20553664

  13. Comparing numbers of drinks: college students' reports from retrospective summary, followback, and prospective daily diary measures.

    Science.gov (United States)

    Patrick, Megan E; Lee, Christine M

    2010-07-01

    Retrospective summary, followback (retrospective diaries), and prospective daily diary measures of alcohol use among college students were compared across 29 days. Participants were college students (n = 176; 60.2% female). Similarities in the three web-based reporting methods and both between-persons (i.e., gender, past drinking behavior, fraternity/sorority affiliation, average drinking behavior during the study period) and within-person (i.e., daily number of drinks, weekend days, Halloween, and week of study) predictors of concordance between reports of followback and prospective diaries were analyzed. On prospective diaries, students reported a greater number of maximum drinks (compared with followback only) and a greater number of heavy drinking days in the past 2 weeks (compared with both followback and retrospective summary measures). In followback compared with prospective diaries, students tended to provide inflated accounts of their drinking behavior when reporting about occasions with greater typical drinking (i.e., weekends, Halloween) and deflated accounts of their drinking on their own heavier drinking days, especially if they were affiliated with a fraternity/sorority. Women and students who drank more on average across study days tended to provide deflated estimates of their day-to-day drinking in followback compared with prospective diary. Understanding the concordance and discordance in self-reported alcohol use is an important area for continued research efforts.

  14. Comparing and assessing different measurement techniques for mercury in coal systhesis gas

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, D.P.; Richardson, C.F. [Radian Corporation, Austin, TX (United States)

    1995-11-01

    Three mercury measurement techniques were performed on synthesis gas streams before and after an amine-based sulfur removal system. The syngas was sampled using (1) gas impingers containing a nitric acid-hydrogen peroxide solution, (2) coconut-based charcoal sorbent, and (3) an on-line atomic absorption spectrophotometer equipped with a gold amalgamation trap and cold vapor cell. Various impinger solutions were applied upstream of the gold amalgamation trap to remove hydrogen sulfide and isolate oxidized and elemental species of mercury. The results from these three techniques are compared to provide an assessment of these measurement techniques in reducing gas atmospheres.

  15. Comparative soil CO2 flux measurements and geostatisticalestimation methods on masaya volcano, nicaragua

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, J.L.; Bergfeld, D.; Cardellini, C.; Chiodini, G.; Granieri, D.; Varley, N.; Werner, C.

    2004-04-27

    We present a comparative study of soil CO{sub 2} flux (F{sub CO2}) measured by five groups (Groups 1-5) at the IAVCEI-CCVG Eighth Workshop on Volcanic Gases on Masaya volcano, Nicaragua. Groups 1-5 measured F{sub CO2} using the accumulation chamber method at 5-m spacing within a 900 m{sup 2} grid during a morning (AM) period. These measurements were repeated by Groups 1-3 during an afternoon (PM) period. All measured F{sub CO2} ranged from 218 to 14,719 g m{sup -2}d{sup -1}. Arithmetic means and associated CO{sub 2} emission rate estimates for the AM data sets varied between groups by {+-}22%. The variability of the five measurements made at each grid point ranged from {+-}5 to 167% and increased with the arithmetic mean. Based on a comparison of measurements made by Groups 1-3 during AM and PM times, this variability is likely due in large part to natural temporal variability of gas flow, rather than to measurement error. We compared six geostatistical methods (arithmetic and minimum variance unbiased estimator means of uninterpolated data, and arithmetic means of data interpolated by the multiquadric radial basis function, ordinary kriging, multi-Gaussian kriging, and sequential Gaussian simulation methods) to estimate the mean and associated CO{sub 2} emission rate of one data set and to map the spatial F{sub CO2} distribution. While the CO{sub 2} emission rates estimated using the different techniques only varied by {+-}1.1%, the F{sub CO2} maps showed important differences. We suggest that the sequential Gaussian simulation method yields the most realistic representation of the spatial distribution of F{sub CO2} and is most appropriate for volcano monitoring applications.

  16. Comparative Study of Ultrasonographic and Anthropometric Measurements of Regional Adiposity in Metabolic Syndrome

    Science.gov (United States)

    Ibrahim, Jebin; Prasanthi, Krishna; Reddy, Harish T; Shah, Rushit Sandeep; Haritha, Ch

    2017-01-01

    Introduction Metabolic syndrome is complex disorder unifying dyslipidemia, insulin resistance and hyper insulinemia. Rising global epidemic of obesity has tremendous impact on metabolic syndrome. Ultrasound is becoming widely utilized modality for measuring the visceral adiposity. Aim To determine the usefulness of ultrasonographic measurements in the estimation of regional adiposity and to compare them with anthropometric measurements and to correlate ultrasonographic measurements of regional adiposity and metabolic syndrome. Materials and Methods A cross-sectional study was conducted to compare anthropometry and ultrasonography in assessing the regional adiposity in metabolic syndrome. A total of 105 consecutive participants were included in the study after scrutinizing them for various definable factors of metabolic syndrome. Body Mass Index (BMI) of all participants was calculated and their available serological investigations were gathered. Primarily participants were subjected for anthropometric measurements like waist circumference and hip circumference, further waist/hip ratio was calculated. Following which all participants underwent sonological examination and sonographic indices like intraabdominal fat thickness, preperitoneal fat thickness, minimum and maximum subcutaneous fat thicknesses were measured. Abdominal wall fat index was calculated as ratio of maximum preperitoneal fat thickness to minimum subcutaneous fat thickness. Statistical analysis was performed using SPSS (Statistical Package Social Science, version-10.0.5) software. A p-value was calculated and values <0.05 were considered as statistically significant. Results Significant correlation was established between the BMI and waist and hip circumferences. Mild positive correlation was obtained between BMI and sonographic indices like IAF, SCF and PPF with Pearson correlation (r) values of 0.324, 0.585 and 0.211 respectively. Anthropometric measurements showed higher r-values (WC- 0.624 and

  17. Comparation of Some Values of Measured Parameteres between Old and New X-Ray Machines

    International Nuclear Information System (INIS)

    Kocic, B.; Marinkovic, J.; Praskalo, J.

    2013-01-01

    Checking the change of values of parameters like specific value of kerma, repeatability of expositions, linearity of exposition, stability of high voltage, time of exposition and HVL of X-ray machines that are in use in medical centres of Republic of Serbia give us an idea of comparing those values for two groups of X-ray machines. One is in use since 70's in last century and is still in use, and the other group is quite new, and is controlled for last 5 years. Checking the results of controlled parameters within those two groups of X-ray machines we can compare stability and quality of old and new machines, and the influence of 'aging' of machines to the quality and stability of measured parameters. Some of conclusions are that old machines are showing better stability and repeatability of values of measured parameters during the 'aging' than new machines.(author)

  18. Comparative study of speed estimators with highly noisy measurement signals for Wind Energy Generation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, O. [Escuela Superior de Computo, Instituto Politecnico Nacional, Av. Juan de Dios Batiz S/N, Col. Lindavista, Del. Gustavo A. Madero 7738, D.F. (Mexico); Figueres, E.; Garcera, G. [Grupo de Sistemas Electronicos Industriales, Departamento de Ingenieria Electronica, Universidad Politecnica de Valencia, Camino de Vera S/N, 7F, 46020 Valencia (Spain); Gonzalez, L.G. [Departamento de Ingenieria Electronica, Universidad de los Andes, Merida (Venezuela)

    2011-03-15

    This paper presents a comparative study of several speed estimators to implement a sensorless speed control loop in Wind Energy Generation Systems driven by power factor correction three-phase boost rectifiers. This rectifier topology reduces the low frequency harmonics contents of the generator currents and, consequently, the generator power factor approaches unity whereas undesired vibrations of the mechanical system decrease. For implementation of the speed estimators, the compared techniques start from the measurement of electrical variables like currents and voltages, which contain low frequency harmonics of the fundamental frequency of the wind generator, as well as switching frequency components due to the boost rectifier. In this noisy environment it has been analyzed the performance of the following estimation techniques: Synchronous Reference Frame Phase Locked Loop, speed reconstruction by measuring the dc current and voltage of the rectifier and speed estimation by means of both an Extended Kalman Filter and a Linear Kalman Filter. (author)

  19. Modeling Nonlinear Power Amplifiers in OFDM Systems from Subsampled Data: A Comparative Study Using Real Measurements

    Directory of Open Access Journals (Sweden)

    Santamaría Ignacio

    2003-01-01

    Full Text Available A comparative study among several nonlinear high-power amplifier (HPA models using real measurements is carried out. The analysis is focused on specific models for wideband OFDM signals, which are known to be very sensitive to nonlinear distortion. Moreover, unlike conventional techniques, which typically use a single-tone test signal and power measurements, in this study the models are fitted using subsampled time-domain data. The in-band and out-of-band (spectral regrowth performances of the following models are evaluated and compared: Saleh's model, envelope polynomial model (EPM, Volterra model, the multilayer perceptron (MLP model, and the smoothed piecewise-linear (SPWL model. The study shows that the SPWL model provides the best in-band characterization of the HPA. On the other hand, the Volterra model provides a good trade-off between model complexity (number of parameters and performance.

  20. Measures of satisfaction with care during labour and birth: a comparative review

    Science.gov (United States)

    2013-01-01

    Background Satisfaction is the one of the most frequently reported outcome measures for quality of care. Assessment of satisfaction with maternity services is crucial, and psychometrically sound measures are needed if this is to inform health practices. This paper comparatively reviews current measures of satisfaction with care during labour and birth. Methods A review of the literature was conducted. Studies were located through computerised databases and hand searching references of identified articles and reviews. Inclusion criteria were that the questionnaire was a multi-item scale of satisfaction with care during labour and birth, and some form of psychometric information (either information about questionnaire construction, or reliability, or validity) had to be reported. Results Nine questionnaires of satisfaction with care during labour and birth were identified. Instruments varied in psychometric properties and dimensions. Most described questionnaire construction and tested some form of reliability and validity. Measures were generally not based on the main theoretical models of satisfaction and varied in scope and application to different types of samples (e.g. satisfaction following caesarean section). For an in-depth measure of satisfaction with intrapartum care, the Intrapartal-Specific Quality from the Patient’s Perspective questionnaire (QPP-I) is recommended. Brief measures with good reliability and validity are provided by the Six Simple Questions (SSQ) or Perceptions of Care Adjective Checklist (PCACL-R). Conclusions Despite the interest in measures of satisfaction there are only a small number of validated measures of satisfaction with care during labour and birth. It is important that brief, reliable and valid measures are available for use in general and specific populations in order to assist research and inform practice. PMID:23656701

  1. Geometric Renyi divergence: A comparative measure with applications to atomic densities

    International Nuclear Information System (INIS)

    Antolin, J.; Bouvrie, P. A.; Angulo, J. C.

    2011-01-01

    An alternative one-parameter measure of divergence is proposed, quantifying the discrepancy among general probability densities. Its main mathematical properties include (i) comparison among an arbitrary number of functions, (ii) the possibility of assigning different weights to each function according to its relevance on the comparative procedure, and (iii) ability to modify the relative contribution of different regions within the domain. Applications to the study of atomic density functions, in both conjugated spaces, show the versatility and universality of this divergence.

  2. AeroCom INSITU Project: Comparing modeled and measured aerosol optical properties

    Science.gov (United States)

    Andrews, Elisabeth; Schmeisser, Lauren; Schulz, Michael; Fiebig, Markus; Ogren, John; Bian, Huisheng; Chin, Mian; Easter, Richard; Ghan, Steve; Kokkola, Harri; Laakso, Anton; Myhre, Gunnar; Randles, Cynthia; da Silva, Arlindo; Stier, Phillip; Skeie, Ragnehild; Takemura, Toshihiko; van Noije, Twan; Zhang, Kai

    2016-04-01

    AeroCom, an open international collaboration of scientists seeking to improve global aerosol models, recently initiated a project comparing model output to in-situ, surface-based measurements of aerosol optical properties. The model/measurement comparison project, called INSITU, aims to evaluate the performance of a suite of AeroCom aerosol models with site-specific observational data in order to inform iterative improvements to model aerosol modules. Surface in-situ data has the unique property of being traceable to physical standards, which is an asset in accomplishing the overall goal of bettering the accuracy of aerosols processes and the predicative capability of global climate models. Here we compare dry, in-situ aerosol scattering and absorption data from ~75 surface, in-situ sites from various global aerosol networks (including NOAA, EUSAAR/ACTRIS and GAW) with a simulated optical properties from a suite of models participating in the AeroCom project. We report how well models reproduce aerosol climatologies for a variety of time scales, aerosol characteristics and behaviors (e.g., aerosol persistence and the systematic relationships between aerosol optical properties), and aerosol trends. Though INSITU is a multi-year endeavor, preliminary phases of the analysis suggest substantial model biases in absorption and scattering coefficients compared to surface measurements, though the sign and magnitude of the bias varies with location. Spatial patterns in the biases highlight model weaknesses, e.g., the inability of models to properly simulate aerosol characteristics at sites with complex topography. Additionally, differences in modeled and measured systematic variability of aerosol optical properties suggest that some models are not accurately capturing specific aerosol behaviors, for example, the tendency of in-situ single scattering albedo to decrease with decreasing aerosol extinction coefficient. The endgoal of the INSITU project is to identify specific

  3. Correlations Among Hospital Quality Measures: What "Hospital Compare" Data Tell Us.

    Science.gov (United States)

    Hu, Jianhui; Jordan, Jack; Rubinfeld, Ilan; Schreiber, Michelle; Waterman, Brian; Nerenz, David

    A number of quality rating systems to rank health care providers have been developed over the years with the intention of helping consumers make informed health care purchasing decisions. Many use sets of individual quality measures to calculate a global rating. The utility of a global rating for consumer choice hinges on the relationships among included measures and the extent to which they jointly reflect an underlying dimension of quality. Publicly reported data on 4 quality domains-complication, mortality, readmission, and patient safety-from Centers for Medicare & Medicaid Services' Hospital Compare website were used to examine correlations among individual measures within each measure group (within-group correlations) and correlations between pairs of measures across different measure groups (between-group correlations). Modest within-group correlations were found in only 2 domains (mortality and readmission), and there were no meaningful between-group associations. These findings raise questions about whether consumers can reliably depend on global quality ratings to make informed decisions.

  4. Measurement of gingival thickness using digital vernier caliper and ultrasonographic method: a comparative study.

    Science.gov (United States)

    Sharma, Swati; Thakur, Srinath L; Joshi, Shyamsunder K; Kulkarni, Sudhindra S

    2014-05-01

    The measurement of the thickness of the gingival tissues has been done using different techniques. Trans-gingival probing with a graduated probe, use of vernier calipers, ultrasonography and cone-beam computed tomography (CBCT), have all been tried, but no one technique has been shown to be consistent and better than the others. The present study was done to evaluate and compare the gingival thickness as measured with a digital vernier caliper and ultrasonography. A total of 30 systemically healthy, non-smokers were included in the study. The gingival measurements were made and recorded from the maxillary and mandibular lateral incisor areas at 2 locations: (a) at a point apical to the free gingival groove; and (b) at a point immediately coronal to the muco-gingival junction. The mean gingival thickness ranged from 0.56 to 1.02 mm. Males had a significantly thicker gingiva as compared to females (P caliper and those made with ultrasonography were compared. The thickness of the gingiva was in the range of 0.56-1.02 mm. A digital vernier caliper and ultrasonography both can be used to assess the gingival thickness with equal accuracy. © 2013 Wiley Publishing Asia Pty Ltd.

  5. Rotor equivalent wind speed for power curve measurement - comparative exercise for IEA Wind Annex 32

    Science.gov (United States)

    Wagner, R.; Cañadillas, B.; Clifton, A.; Feeney, S.; Nygaard, N.; Poodt, M.; St. Martin, C.; Tüxen, E.; Wagenaar, J. W.

    2014-06-01

    A comparative exercise has been organised within the International Energy Agency (IEA) Wind Annex 32 in order to test the Rotor Equivalent Wind Speed (REWS) method under various conditions of wind shear and measurement techniques. Eight organisations from five countries participated in the exercise. Each member of the group has derived both the power curve based on the wind speed at hub height and the power curve based on the REWS. This yielded results for different wind turbines, located in diverse types of terrain and where the wind speed profile was measured with different instruments (mast or various lidars). The participants carried out two preliminary steps in order to reach consensus on how to implement the REWS method. First, they all derived the REWS for one 10 minute wind speed profile. Secondly, they all derived the power curves for one dataset. The main point requiring consensus was the definition of the segment area used as weighting for the wind speeds measured at the various heights in the calculation of the REWS. This comparative exercise showed that the REWS method results in a significant difference compared to the standard method using the wind speed at hub height in conditions with large shear and low turbulence intensity.

  6. Comparative study of global and local magnetization measurements on single crystalline high- Tc superconductors

    Science.gov (United States)

    Werner, M.; Brandstätter, G.; Sauerzopf, F. M.; Weber, H. W.; Hoekstra, A.; Surdeanu, R.; Wijngaarden, R. J.; Griessen, R.; Abulafia, Y.; Yeshurun, Y.; Winzer, K.; Veal, B. W.

    1998-07-01

    The mixed state of several (RE)Ba 2Cu 3O 7-δ single crystals (RE=Y,Yb) was investigated by various measuring techniques. Using an 8 T SQUID magnetometer as a reference, we compare the current densities evaluated from global magnetization measurements (SQUID, torque and VSM) and from a local technique (Hall probe array). Taking the specific time scales of the various measurements into consideration, we obtain excellent agreement at all temperatures from 5 to 77 K. Magneto-optical images of the flux density gradients confirm that the current densities can be calculated on the basis of an extended Bean model. The established correspondence between global and local techniques is of fundamental relevance for future experimental work on the subject.

  7. Comparing and Combining Measurement-Based and Driven-Dissipative Entanglement Stabilization*

    Directory of Open Access Journals (Sweden)

    Y. Liu

    2016-03-01

    Full Text Available We demonstrate and contrast two approaches to the stabilization of qubit entanglement by feedback. Our demonstration is built on a feedback platform consisting of two superconducting qubits coupled to a cavity, which are measured by a nearly quantum-limited measurement chain and controlled by high-speed classical logic circuits. This platform is used to stabilize entanglement by two nominally distinct schemes: a “passive” reservoir engineering method and an “active” correction based on conditional parity measurements. In view of the instrumental roles that these two feedback paradigms play in quantum error correction and quantum control, we directly compare them on the same experimental setup. Furthermore, we show that a second layer of feedback can be added to each of these schemes, which heralds the presence of a high-fidelity entangled state in real time. This “nested” feedback brings about a marked entanglement fidelity improvement without sacrificing success probability.

  8. Does the Conceptualization and Measurement of Democracy Quality Matter in Comparative Climate Policy Research?

    Directory of Open Access Journals (Sweden)

    Romy Escher

    2018-03-01

    Full Text Available Previous empirical research on democracy and global warming has mainly questioned whether democracy contributes to climate protection. However, there is no consensus in the theoretical literature on what institutional traits of democracy are crucial for climate policy. Thus, results based on indices that summarize multiple democracy quality dimensions could be misleading, as their effects could balance each other out or hide the relative importance of each institutional trait. This article examines whether the analysis of the effects of democracy quality dimensions, measured by separate indicators, contributes to a better understanding of cross-national variance in climate policy compared to the focus on the regime type difference, measured by democracy quality measures. Compared to earlier research, the results indicate that the positive effect of democracy on commitment to climate cooperation depends on the realization of political rights. We find little to support the claim that democracy quality dimensions matter for climate policy outcomes. The main implication of our findings is that it could be fruitful to use more disaggregated democracy measures for the analysis of substantive research questions.

  9. Assessment of femoral component migration in total hip arthroplasty: digital measurements compared to RSA.

    Science.gov (United States)

    Schütz, Uwe; Decking, Jens; Decking, Ralf; Puhl, Wolfhart

    2005-02-01

    The aim of this study was to determine the accuracy of the software system "Düsseldorf Migration Analysis - Femoral Component Analysis" (DMA-FCA) in measuring stem migration in total hip arthroplasty (THA) on digitised anteroposterior radiographs of the pelvis. Bony and implant landmarks on two consecutive radiographs were used for measurements of subsidence and varus-valgus tilt. The accuracy of the method was determined by reference to radiostereometric measurements (RSA). Using specific comparability limits, comparability analysis of radiographs with respect to femoral positioning is possible with DMA. DMA-FCA and RSA measurements were performed after cementless THR in a population of 60 patients aged 38 to 69 years. With a Cronbach's alpha-index of 0.89 and 0.99 for subsidence and 0.90 and 0.98 for classic varus-valgus-tilt, the intraobserver and interobserver reliability for the DMA-FCA-method was calculated as good. Using RSA as reference method, the accuracy of DMA-FCA was calculated to be 2.51 mm for subsidence and 2.49 degrees for varus-valgus-tilt (95% confidence interval). Without comparison to RSA, DMA measured 1.94 mm for subsidence and 2.35 degrees for varus-valgus-tilt. Based on a comparison with RSA, our results show lower accuracy for DMA-FCA than for EBRA-FCA, but DMA-FCA is easier to use in everyday clinical practice. It is hoped that the use of digital measuring methods such as DMA will become standard for long-term observation and will be integrated into clinical routine in the context of quality assurance of THR.

  10. A comparative study of linear measurement of the brain and three-dimensional measurement of brain volume using CT scans

    International Nuclear Information System (INIS)

    Hamano, K.; Iwasaki, N.; Takeya, T.; Takita, H.

    1993-01-01

    Parameters of linear measurement were compared with actual brain volume to assess the significance of linear measurements as indices of atrophy in 31 neurologically normal children and 22 neurologically abnormal children. Brain volume was established by means of an image-analyzing system using contiguous CT scans. The parameters or indices estimated were: (1) the maximum transverse width of both hemispheres, (2) the maximum longitudinal length of both hemispheres, (3) the maximum frontal subarachnoid space, (4) the maximum width of the interhemispheric fissure, (5) the maximum width of the Sylvian fissure, (6) Evans' ratio, (7) the maximum width of the third ventricle, (8) the cella media index, (9) the maximum width of the fourth ventricle. In neurologically normal children, the maximum transverse width of both hemispheres, the maximum longitudinal length of both hemispheres, the maximum width of the interhemispheric fissure and the maximum width of the Sylvian fissure correlated significantly with the combined volume (CV) of both hemipheres and basal ganglia. In particular, the maximum transverse width of both hemispheres and the maximum longitudinal length of both hemispheres had a high correlation. In neurologically abnormal children the maximum transverse width of both hemispheres and the maximum width of the interhemispheric fissure were significantly correlated with the CV of both hemispheres and basal ganglia. (orig.)

  11. 2D Spatial Frequency Considerations in Comparing 1D Power Spectral Density Measurements

    International Nuclear Information System (INIS)

    Takacs, P.Z.; Barber, S.; Church, E.L.; Kaznatcheev, K.; McKinney, W.R.; Yashchuk, V.Y.

    2010-01-01

    The frequency footprint of ID and 2D profiling instruments needs to be carefully considered in comparing ID surface roughness spectrum measurements made by different instruments. Contributions from orthogonal direction frequency components can not be neglected. The use of optical profiling instruments is ubiquitous in the measurement of the roughness of optical surfaces. Their ease-of-use and non-contact measurement method found widespread use in the optics industry for measuring the quality of delicate optical surfaces. Computerized digital data acquisition with these instruments allowed for quick and easy calculation of surface roughness statistics, such as root-mean-square (RMS) roughness. The computing power of the desktop computer allowed for the rapid conversion of spatial domain data into the frequency domain, enabling the application of sophisticated signal processing techniques to be applied to the analysis of surface roughness, the most powerful of which is the power spectral density (PSP) function. Application of the PSD function to surface statistics introduced the concept of 'bandwidth-limited' roughness, where the value of the RMS roughness depends critically upon the spatial frequency response of the instrument. Different instruments with different spatial frequency response characteristics give different answers when measuring the same surface.

  12. COMPARATIVE MEASUREMENTS OF HEAD ANGULAR MOVEMENTS USING A CAMERA SYSTEM AND A GYROSCOPE SYSTEM

    Directory of Open Access Journals (Sweden)

    Vladimir Socha

    2014-08-01

    Full Text Available Assessments of body-segment angular movements are very important in the rehabilitation process. Head angular movements are measured and analyzed for use in studies of stability and posture. However, there is no methodology for assessing angular movements of the head, and it has not been verified whether data measured by fundamentally different MoCap systems will lead to the same results. In this study, we used a camera system and a 3DOF orientation tracker placed on the subject’s head, and measured inclination (roll and flexion (pitch during quiet stance. The total length and the mean velocity of the traces of the pitch versus roll plots were used to measure and analyze head orientation. Using these methods, we are able to model the distribution of the measured 2D data, and to evaluate stability and posture. The results show that the total lengths and the mean velocities related to the 3DOF orientation tracker do not differ significantly from the total lengths and the mean velocities of traces related to the IR medical camera. We also found that the systems are not interchangeable, and that the same type of system must be used each time. The designed methods can be used for studies not only of head movements but also of movements of other segments of the human body, and can be used to compare other types of MoCap systems, depending on the requirements for a specific rehabilitation examination.

  13. By our bootstraps: Comparing methods for measuring auditory 40 Hz steady-state neural activity.

    Science.gov (United States)

    Edgar, J Christopher; Fisk, Charles L; Chen, Yu-Han; Stone-Howell, Breannan; Hunter, Michael A; Huang, Mingxiong; Bustillo, Juan R; Cañive, José M; Miller, Gregory A

    2017-08-01

    Although the 40 Hz auditory steady-state response (ASSR) is of clinical interest, the construct validity of EEG and MEG measures of 40 Hz ASSR cortical microcircuits is unclear. This study evaluated several MEG and EEG metrics by leveraging findings of (a) an association between the 40 Hz ASSR and age in the left but not right hemisphere, and (b) right- > left-hemisphere differences in the strength of the 40 Hz ASSR. The contention is that, if an analysis method does not demonstrate a left 40 Hz ASSR and age relationship or hemisphere differences, then the obtained measures likely have low validity. Fifty-three adults were presented 500 Hz stimuli modulated at 40 Hz while MEG and EEG were collected. ASSR activity was examined as a function of phase similarity (intertrial coherence) and percent change from baseline (total power). A variety of head models (spherical and realistic) and a variety of dipole source modeling strategies (dipole source localization and dipoles fixed to Heschl's gyri) were compared. Several sensor analysis strategies were also tested. EEG sensor measures failed to detect left 40 Hz ASSR and age associations or hemisphere differences. A comparison of MEG and EEG head-source models showed similarity in the 40 Hz ASSR measures and in estimating age and left 40 Hz ASSR associations, indicating good construct validity across models. Given a goal of measuring the 40 Hz ASSR cortical microcircuits, a source-modeling approach was shown to be superior in measuring this construct versus methods that rely on EEG sensor measures. © 2017 Society for Psychophysiological Research.

  14. Monitoring of formaldehyde in air.

    Science.gov (United States)

    Balmat, J L; Meadows, G W

    1985-10-01

    Any one of several monitoring methods, depending on requirement and circumstance, can be used to measure employee exposure to formaldehyde. Ordinarily, monitoring at DuPont is performed by sampling with impingers containing 1% aqueous sodium bisulfite or with silica gel tubes. The collected formaldehyde is measured spectrophotometrically after reaction with chromotropic acid. Results from studies on a selected number of formaldehyde monitoring methods reveal that reliable methods are available for area and personnel monitoring over both short term and long term. Accurate results are obtained from short-term monitoring (15 min at 1 L/min) with impingers of formaldehyde concentrations as low as 0.14 ppm. The current studies show that long-term monitoring (8 hr at 0.5 L/min) can be performed accurately at concentrations as low as 0.05 ppm. Accurate results also are obtained from short-term monitoring (15 min at 500 mL/min) with silica gel tubes of concentrations as low as 0.11 ppm formaldehyde; the lower limit established in the current studies for long-term monitoring (8 hr at 30 mL/min) is 0.15 ppm. Passive monitors provide the most convenient means of obtaining 8-hour time-weighted average (TWA) data. The Pro-Tek Formaldehyde Badge was demonstrated to reliably monitor formaldehyde concentrations varying from 0-0.5 ppm or 0-3 ppm. All of these methods satisfy the NIOSH criterion for acceptability that all results fall within +/- 25% of the true value at the 95% confidence level. Investigation of the Lion Formaldemeter disclosed that instantaneous and accurate (+/- 5%) measurement of formaldehyde in air can be made over a concentration range of 0.3-5 ppm in the absence of other substances that are oxidizable in its fuel cell detector.

  15. Comparative scatterometric CD measurements on a MoSi photo mask using different metrology tools

    Science.gov (United States)

    Richter, Jan; Rudolf, Jens; Bodermann, Bernd; Lam, John C.

    2008-10-01

    The demands on CD metrology techniques in terms of both reproducibility and measurement uncertainty increase with decreasing critical dimensions (CD) on lithography masks. Additionally a full 3D characterization of the mask structures becomes more and more important to understand and control the printing behavior of state of the art photomasks. Furthermore, an extension of metrology characterization including material properties can provide the final puzzle pieces for a better correlation of mask metrology to wafer metrology. Here, optical metrology systems, especially at-wavelength systems, are very well suited to characterize structure features of a photomask regarding their printing behavior on a wafer. In particular scatterometry is able to provide a better understanding of the investigated structure and allows for modeling of secondary structure parameters as well as material composition. AMTC has a commercial scatterometer from n&k Technology (n&k 5700-CDRT) in use. This system measures the spectral transmission and reflection, the 0th diffraction order. Beside thin film characterization this system is used for CD and edge profile characterization, also. The analysis of the data uses a look-up table approach in combination with a database, which has been generated and can be expanded, respectively, using a RCWA based software. At PTB we have realized a new DUV hybrid scatterometer which combines essential elements of a radiometer, an ellipsometer, and a diffractometer. These two systems are different both in terms of the measurement modes, the data evaluation method and the Maxwell-solver used. Therefore we started to compare the performance of both systems to traditional metrology system for CD metrology and phase measurement. For this purpose we performed first comparative scatterometric measurements on a MoSi phase shifting mask.

  16. Measurement of Post Void Residual Urine Volume Using Portable 3D Ultrasound Compared with Urinary Catheterization

    Directory of Open Access Journals (Sweden)

    Pichai Leerasiri

    2017-05-01

    Full Text Available Objective: To find out correlation between the 3D ultrasound and conventional urethral catheterization in terms of measurement accuracy of post void residual urine (PVR volume, pain score, and elapsed time among patients attending Urogynecology Clinic, Siriraj Hospital between December 2011 to December 2012. Methods: With the approval of the institution’s Ethics Committees, a total of 64 participants were enrolled. Participants with conditions that could affect bladder volume, including previous pelvic surgery and radiation, abnormal anatomy of genitourinary system, and contraindications for urethral catheterization were excluded. A questionnaire asking about demographic data and clinical presentation of each participant was completed. PVR volume was measured using the BladderScan® (BVI-9400, followed by urethral catheterization. Differences between PVR volume and elapsed time in both procedures were determined. At the end of each procedure every participant was asked to rate the pain score, from 0 (no pain to 10 (most severe pain, according to the Visual Analog Scale. Results: The mean age was 60 years old, ranging from 33 to 81. The mean body mass index (BMI was 26.5 kg/m2± 4.1. The PVR volume measured by the BladderScan® was significantly correlated with that measured by the conventional catheterization with the correlation coefficient of 0.92 (p<0.001. The mean pain score in the BladderScan® group was obviously less when compared with that of the catheterization group (0.59 ± 1.19 vs 3.00 ± 2.07; p<0.001. The mean time used in the BladderScan® group was significantly lower than that in the catheterization group. Conclusion: The BladderScan® had high correlation, time saving and less pain compared to conventional urethral catheterization for measurement of the post-void residual urine volume.

  17. Comparative performance of three experimental hut designs for measuring malaria vector responses to insecticides in Tanzania.

    Science.gov (United States)

    Massue, Dennis J; Kisinza, William N; Malongo, Bernard B; Mgaya, Charles S; Bradley, John; Moore, Jason D; Tenu, Filemoni F; Moore, Sarah J

    2016-03-15

    Experimental huts are simplified, standardized representations of human habitations that provide model systems to evaluate insecticides used in indoor residual spray (IRS) and long-lasting insecticidal nets (LLINs) to kill disease vectors. Hut volume, construction materials and size of entry points impact mosquito entry and exposure to insecticides. The performance of three standard experimental hut designs was compared to evaluate insecticide used in LLINs. Field studies were conducted at the World Health Organization Pesticide Evaluation Scheme (WHOPES) testing site in Muheza, Tanzania. Three East African huts, three West African huts, and three Ifakara huts were compared using Olyset(®) and Permanet 2.0(®) versus untreated nets as a control. Outcomes measured were mortality, induced exophily (exit rate), blood feeding inhibition and deterrence (entry rate). Data were analysed using linear mixed effect regression and Bland-Altman comparison of paired differences. A total of 613 mosquitoes were collected in 36 nights, of which 13.5% were Anopheles gambiae sensu lato, 21% Anopheles funestus sensu stricto, 38% Mansonia species and 28% Culex species. Ifakara huts caught three times more mosquitoes than the East African and West African huts, while the West African huts caught significantly fewer mosquitoes than the other hut types. Mosquito densities were low, very little mosquito exit was measured in any of the huts with no measurable exophily caused by the use of either Olyset or Permanet. When the huts were directly compared, the West African huts measured greater exophily than other huts. As unholed nets were used in the experiments and few mosquitoes were captured, it was not possible to measure difference in feeding success either between treatments or hut types. In each of the hut types there was increased mortality when Permanet or Olyset were present inside the huts compared to the control, however this did not vary between the hut types. Both East African

  18. Comparing modeled isoprene with aircraft-based measurements in the atmospheric boundary layer.

    Energy Technology Data Exchange (ETDEWEB)

    Doskey, P.; Gao, W.

    1997-12-12

    Nonmethane hydrocarbons (NMHCs) are involved in a complex series of reactions that regulate the levels of oxidants in the troposphere. Isoprene (C{sub 5}H{sub 8}), the primary NMHC emitted from deciduous trees, is one of the most important reactive hydrocarbons in the troposphere. The amount of isoprene entering the free troposphere is regulated by the compound's rate of emission from leaves and by chemical and physical processes in the forest canopy and the atmospheric boundary layer (ABL). This study uses a coupled canopy-ABL model to simulate these complex processes and compares calculated isoprene concentration profiles with those measured during aircraft flights above a forested region in the northeastern US. Land use information is coupled with satellite remote sensing data to describe spatial changes in canopy density during the field measurements. The high-resolution transport-chemistry model of Gao et al. (1993) for the ABL and the forest canopy layer is used to simulate vertical changes in isoprene concentration due to turbulent mixing and chemical reactions. The one-dimensional (1-D) ABL model includes detailed radiation transfer, turbulent diffusion, biogenic emissions, dry deposition, and chemical processes within the forest canopy and the ABL. The measured profiles are compared with the model simulations to investigate the biological, physical, and chemical processes that regulate the levels of isoprene within the ABL.

  19. SQUID Based Cryogenic Current Comparator for Measurements of the Dark Current of Superconducting Cavities

    CERN Document Server

    Vodel, W; Neubert, R; Nietzsche, S

    2005-01-01

    This contribution presents a LTS-SQUID based Cryogenic Current Comparator (CCC) for detecting dark currents, generated e.g. by superconducting cavities for the upcoming X-FEL project at DESY. To achieve the maximum possible energy the gradients of the superconducting RF cavities should be pushed close to the physical limit of 50 MV/m. The measurement of the undesired field emission of electrons (the so-called dark current) in correlation with the gradient will give a proper value to compare and classify the cavities. The main component of the CCC is a high performance LTS-DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the extracted dark current. For this reason the input coil of the SQUID is connected across a special designed toroidal niobium pick-up coil (inner diameter: about 100 mm) for the passing electron beam. A noise limited current resolution of nearly 2 pA/√(Hz) with a measurement bandwidth of up to 70 kHz was achieved without the pick-up coil. Now, ...

  20. Technical note: comparing von Luschan skin color tiles and modern spectrophotometry for measuring human skin pigmentation.

    Science.gov (United States)

    Swiatoniowski, Anna K; Quillen, Ellen E; Shriver, Mark D; Jablonski, Nina G

    2013-06-01

    Prior to the introduction of reflectance spectrophotometry into anthropological field research during the 1950s, human skin color was most commonly classified by visual skin color matching using the von Luschan tiles, a set of 36 standardized, opaque glass tiles arranged in a chromatic scale. Our goal was to establish a conversion formula between the tile-based color matching method and modern reflectance spectrophotometry to make historical and contemporary data comparable. Skin pigmentation measurements were taken on the forehead, inner upper arms, and backs of the hands using both the tiles and a spectrophotometer on 246 participants showing a broad range of skin pigmentation. From these data, a second-order polynomial conversion formula was derived by jackknife analysis to estimate melanin index (M-index) based on tile values. This conversion formula provides a means for comparing modern data to von Luschan tile measurements recorded in historical reports. This is particularly important for populations now extinct, extirpated, or admixed for which tile-based measures of skin pigmentation are the only data available. Copyright © 2013 Wiley Periodicals, Inc.

  1. COMPARATIVE KINEMATIC MEASURES OF TREADMILL RUNNING WITH OR WITHOUT BODY WEIGHT SUPPORT IN RUNNERS

    Directory of Open Access Journals (Sweden)

    Duane Millslagle

    2005-12-01

    Full Text Available Treadmill walking and running using a supportive harness has been used as a training method to rehabilitate injured patients' walking or running gait. Comparison of full weight support (FWS and body weight support (BWS kinematic measures in competitive runners has received little attention. The purpose of this study was to compare selected FWS to BWS kinematic measures in healthy competitive runners. Ten male runners (age = 21.4 ± 1.5 years with a training regimen averaging 64 km per week at 3.8 m·s-1 participated. All participants ran three 3-minute trials. The randomized trial conditions were: FWS, 20% BWS, and 40% BWS. All conditions were videotaped with 2 cameras and a 21-point, 3-D model was generated for analysis. From the position-time data, cycle length (CL, cycle frequency (CF, time of contact (TC, hip-, knee-, ankle- range of motion in degrees (H-ROM, K-ROM, and A-ROM, respectively, and vertical displacement of the center of mass (COM were derived and compared. With increasing support conditions, cycle length increased. Cycle frequency, hip and ankle angle ranges, and COM vertical displacement decreased (p 0.05. BWS running produced significant changes in selected kinematic measures. These changes may provide insight into runners' behavior when using BWS in training or recovery from competition. Additional investigation of BWS training affect with competitive runners would be recommended

  2. Comparing Traditional Service Delivery and Telepractice for Speech Sound Production Using a Functional Outcome Measure.

    Science.gov (United States)

    Coufal, Kathy; Parham, Douglas; Jakubowitz, Melissa; Howell, Cassandra; Reyes, Jared

    2018-02-06

    Using American Speech-Language-Hearing Association's (ASHA's) National Outcomes Measurement System (NOMS) Functional Communication Measure (FCM) as a common metric, this investigation compared traditional service delivery and telepractice service delivery for children receiving therapy for the NOMS diagnostic category of "speech sound production." De-identified cases were secured from ASHA's NOMS database and a proprietary database from a private e-learning provider. Cases were included if they met 3 criteria: (a) children received treatment exclusively for speech sound production, (b) they were between 6.0 and 9.5 years old, and (c) they received therapy lasting between 4 and 9 months. A total of 1,331 ASHA NOMS cases and 428 telepractice cases were included. The 2 groups were matched by initial FCM scores. Mann-Whitney U tests were completed to compare differences in the median change scores (the difference between the initial and final FCM scores) between the 2 groups. There were no significant differences in the median change scores between the traditional group and the telepractice group. These results suggest comparable treatment outcomes between traditional service delivery and telepractice for treatment of children exhibiting speech sound disorders. The findings provide support for the use of telepractice for school-age children.

  3. Application of analytic hierarchy process for measuring and comparing the global performance of intensive care units.

    Science.gov (United States)

    Hariharan, Seetharaman; Dey, Prasanta K; Chen, Deryk R; Moseley, Harley S L; Kumar, Areti Y

    2005-06-01

    To develop a model for the global performance measurement of intensive care units (ICUs) and to apply that model to compare the services for quality improvement. Analytic hierarchy process, a multiple-attribute decision-making technique, is used in this study to evolve such a model. The steps consisted of identifying the critical success factors for the best performance of an ICU, identifying subfactors that influence the critical factors, comparing them pairwise, deriving their relative importance and ratings, and calculating the cumulative performance according to the attributes of a given ICU. Every step in the model was derived by group discussions, brainstorming, and consensus among intensivists. The model was applied to 3 ICUs, 1 each in Barbados, Trinidad, and India in tertiary care teaching hospitals of similar setting. The cumulative performance rating of the Barbados ICU was 1.17 when compared with that of Trinidad and Indian ICU, which were 0.82 and 0.75, respectively, showing that the Trinidad and Indian ICUs performed 70% and 64% with respect to Barbados ICU. The model also enabled identifying specific areas where the ICUs did not perform well, which helped to improvise those areas. Analytic hierarchy process is a very useful model to measure the global performance of an ICU.

  4. Lean in Air Permitting Guide

    Science.gov (United States)

    The Lean in Air Permitting Guide is designed to help air program managers at public agencies better understand the potential value and results that can be achieved by applying Lean improvement methods to air permitting processes.

  5. Degeneration and height of cervical discs classified from MRI compared with precise height measurements from radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Kolstad, Frode [National Centre of Spinal Disorders, Norwegian University of Science and Technology, University Hospital of Trondheim, 7006 Trondheim (Norway)]. E-mail: frode.kolstad@medisin.ntnu.no; Myhr, Gunnar [Department of Radiology, University Hospital of Trondheim, 7006 Trondheim (Norway); Kvistad, Kjell Arne [Department of Radiology, University Hospital of Trondheim, 7006 Trondheim (Norway); Nygaard, Oystein P. [National Centre of Spinal Disorders, Norwegian University of Science and Technology, University Hospital of Trondheim, 7006 Trondheim (Norway); Leivseth, Gunnar [Department of Neuromedicine, Faculty of Medicine, Norwegian University of Science and Technology, University Hospital of Trondheim, 7006 Trondheim (Norway)

    2005-09-01

    Study design: Descriptive study comparing MRI classifications with measurements from radiographs. Objectives: 1.Define the relationship between MRI classified cervical disc degeneration and objectively measured disc height. 2.Assess the level of inter- and intra-observer errors using MRI in defining cervical disc degeneration. Summary of background data: Cervical spine degeneration has been defined radiologically by loss of disc height, decreased disc and bone marrow signal intensity and disc protrusion/herniation on MRI. The intra- and inter-observer error using MRI in defining cervical degeneration influences data interpretation. Few previous studies have addressed this source of error. The relation and time sequence between cervical disc degeneration classified by MRI and cervical disc height decrease measured from radiographs is unclear. Methods: The MRI classification of degeneration was based on nucleus signal, prolaps identification and bone marrow signal. Two neuro-radiologists evaluated the MR-images independently in a blinded fashion. The radiographic disc height measurements were done by a new computer-assisted method compensating for image distortion and permitting comparison with normal level-, age- and gender-appropriate disc height. Results/conclusions: 1.Progressing disc degeneration classified from MRI is on average significantly associated with a decrease of disc height as measured from radiographs. Within each MRI defined category of degeneration measured disc heights, however, scatter in a wide range. 2.The inter-observer agreement between two neuro-radiologists in both defining degeneration and disc height by MRI was only moderate. Studies addressing questions related to cervical disc degeneration should take this into consideration.

  6. Degeneration and height of cervical discs classified from MRI compared with precise height measurements from radiographs

    International Nuclear Information System (INIS)

    Kolstad, Frode; Myhr, Gunnar; Kvistad, Kjell Arne; Nygaard, Oystein P.; Leivseth, Gunnar

    2005-01-01

    Study design: Descriptive study comparing MRI classifications with measurements from radiographs. Objectives: 1.Define the relationship between MRI classified cervical disc degeneration and objectively measured disc height. 2.Assess the level of inter- and intra-observer errors using MRI in defining cervical disc degeneration. Summary of background data: Cervical spine degeneration has been defined radiologically by loss of disc height, decreased disc and bone marrow signal intensity and disc protrusion/herniation on MRI. The intra- and inter-observer error using MRI in defining cervical degeneration influences data interpretation. Few previous studies have addressed this source of error. The relation and time sequence between cervical disc degeneration classified by MRI and cervical disc height decrease measured from radiographs is unclear. Methods: The MRI classification of degeneration was based on nucleus signal, prolaps identification and bone marrow signal. Two neuro-radiologists evaluated the MR-images independently in a blinded fashion. The radiographic disc height measurements were done by a new computer-assisted method compensating for image distortion and permitting comparison with normal level-, age- and gender-appropriate disc height. Results/conclusions: 1.Progressing disc degeneration classified from MRI is on average significantly associated with a decrease of disc height as measured from radiographs. Within each MRI defined category of degeneration measured disc heights, however, scatter in a wide range. 2.The inter-observer agreement between two neuro-radiologists in both defining degeneration and disc height by MRI was only moderate. Studies addressing questions related to cervical disc degeneration should take this into consideration

  7. Comparing Pulsed Doppler LIDAR with SODAR and Direct Measurements for Wind Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, N. D.; Jonkman, B. J.; Scott, G. N.; Pichugina, Y. L.

    2007-07-01

    There is a pressing need for good wind-speed measurements at greater and greater heights to assess the availability of the resource in terms of power production and to identify any frequently occurring atmospheric structural characteristics that may create turbulence that impacts the operational reliability and lifetime of wind turbines and their components. In this paper, we summarize the results of a short study that compares the relative accuracies of wind speeds derived from a high-resolution pulsed Doppler LIDAR operated by the National Oceanic and Atmospheric Administration (NOAA) and a midrange Doppler SODAR with wind speeds measured by four levels of tower-based sonic anemometry up to a height of 116 m.

  8. Comparing Measurements of CT Angiography, TEE, and Fluoroscopy of the Left Atrial Appendage for Percutaneous Closure.

    Science.gov (United States)

    Saw, Jacqueline; Fahmy, Peter; Spencer, Ryan; Prakash, Roshan; McLaughlin, Patrick; Nicolaou, Savvas; Tsang, Michael

    2016-04-01

    Left atrial appendage (LAA) closure requires accurate preprocedural measurements, and trans-esophageal echocardiography (TEE), cardiac computed tomography angiography (CCTA) and fluoroscopy can be utilized. However, correlations between these measurements remain inadequately assessed. Patients who underwent LAA closure at Vancouver General Hospital who had baseline LAA measurements by CCTA, TEE, and fluoroscopy were included in this analysis. CCTAs were performed with prospective-ECG-gating with Toshiba 320-detector or Siemens second generation 128-slice dual-source scanners, and images interpreted with VitreaWorkstation.™ LAA maximal dimensions were obtained for all patients at: (1) Amplatzer Cardiac Plug (ACP)/Amulet landing zone 10 mm within orifice, (2) WATCHMAN ostium, and (3) WATCHMAN depth measurements. Correlations and agreements were compared. We report 50 consecutive patients who underwent LAA closure (8 ACP, 10 Amulet, 32 WATCHMAN). Average age was 75.2 ± 8.7 years, mean CHADS2 score 3.0 ± 1.3, and CHA2 DS2 -VASc 4.7 ± 1.5. Procedural device implantation success was 100%. For ACP landing zone, mean maximal measurements were 24.1 ± 4.7 mm with CCTA, 22.3 ± 4.9 mm TEE, and 19.9 ± 5.6 mm fluoroscopy (P fluoroscopy/CTA, 0.67 fluoroscopy/TEE, and 0.80 CTA/TEE. For WATCHMAN ostium, mean maximal measurements were 25.8 ± 4.7 mm CCTA (P fluoroscopy, P = 0.16 vs. TEE), 25.1 ± 4.4 mm TEE (P = 0.016 vs. fluoroscopy), and 23.8 ± 4.9 mm fluoroscopy; R value 0.71 fluoroscopy/CTA, 0.65 fluoroscopy/TEE, and 0.74 CTA/TEE. Depth measurements were 34.3 ± 5.7 mm with CCTA, 31.1 ± 6.5 mm TEE, and 27.8 ± 7.1 mm fluoroscopy (all P fluoroscopy/CTA, 0.22 fluoroscopy/TEE, and 0.56 CTA/TEE. All 3 imaging modalities correlated with ACP landing zone and WATCHMAN ostium measurements, with CCTA providing the largest measurements, followed by TEE and fluoroscopy. © 2016 Wiley Periodicals, Inc.

  9. Comparing Dynamic Treatment Regimes Using Repeated-Measures Outcomes: Modeling Considerations in SMART Studies

    Science.gov (United States)

    Lu, Xi; Nahum-Shani, Inbal; Kasari, Connie; Lynch, Kevin G.; Oslin, David W.; Pelham, William E.; Fabiano, Gregory; Almirall, Daniel

    2016-01-01

    A dynamic treatment regime (DTR) is a sequence of decision rules, each of which recommends a treatment based on a patient’s past and current health status. Sequential, multiple assignment, randomized trials (SMARTs) are multi-stage trial designs that yield data specifically for building effective DTRs. Modeling the marginal mean trajectories of a repeated-measures outcome arising from a SMART presents challenges, because traditional longitudinal models used for randomized clinical trials do not take into account the unique design features of SMART. We discuss modeling considerations for various forms of SMART designs, emphasizing the importance of considering the timing of repeated measures in relation to the treatment stages in a SMART. For illustration, we use data from three SMART case studies with increasing level of complexity, in autism, child attention deficit hyperactivity disorder (ADHD), and adult alcoholism. In all three SMARTs we illustrate how to accommodate the design features along with the timing of the repeated measures when comparing DTRs based on mean trajectories of the repeated-measures outcome. PMID:26638988

  10. Comparing Multi-Informant Assessment Measures of Parental Monitoring and Their Links with Adolescent Delinquent Behavior

    Science.gov (United States)

    Augenstein, Tara M.; Thomas, Sarah A.; Ehrlich, Katherine B.; Daruwala, Samantha; Reyes, Shelby M.; Chrabaszcz, Jeffrey S.; De Los Reyes, Andres

    2016-01-01

    SYNOPSIS Objective Parents’ poor monitoring of adolescents’ whereabouts and activities is commonly linked to adolescents’ increased engagement in delinquent behaviors. Yet, different domains of parental monitoring (parental monitoring behaviors vs. parental knowledge) and reports from multiple informants (parent vs. adolescent) may vary in their links to delinquent behavior. Design Seventy-four parental caregivers and 74 adolescents completed survey measures of parental monitoring and knowledge, and adolescents completed self-report surveys of delinquent behavior. Results We observed low-to-moderate magnitudes of correspondence between parent- and adolescent-reports of parental monitoring behaviors and parental knowledge. Adolescent self-reported delinquent behavior related to parent and adolescent reports of parental monitoring behaviors and parental knowledge, with adolescents who self-reported engagement in delinquent behaviors evidencing lower levels of parental knowledge and higher levels of poor monitoring compared to adolescents who did not self-report engagement in delinquent behaviors. Adolescent self-reported engagement in delinquent behaviors evidenced stronger links to parental monitoring when based on adolescent reports of monitoring (relative to parent reports), whereas stronger links held between adolescent self-reported delinquent behavior and parental knowledge when based on parent reports of knowledge (relative to adolescent reports). Conclusions Links between monitoring and adolescents’ delinquent behavior vary by the kind of monitoring measure completed as well as the informant completing the measure. These findings inform measurement selection in research and clinical assessments of parental monitoring and adolescent delinquent behavior. PMID:27482171

  11. Comparing GIS-based methods of measuring spatial accessibility to health services.

    Science.gov (United States)

    Yang, Duck-Hye; Goerge, Robert; Mullner, Ross

    2006-02-01

    The inequitable geographic distribution of health care resources has long been recognized as a problem in the United States. Traditional measures, such as a simple ratio of supply to demand in an area or distance to the closest provider, are easy measures for spatial accessibility. However the former one does not consider interactions between patients and providers across administrative borders and the latter does not account for the demand side, that is, the competition for the supply. With advancements in GIS, however, better measures of geographic accessibility, variants of a gravity model, have been applied. Among them are (1) a two-step floating catchment area (2SFCA) method and (2) a kernel density (KD) method. This microscopic study compared these two GIS-based measures of accessibility in our case study of dialysis service centers in Chicago. Our comparison study found a significant mismatch of the accessibility ratios between the two methods. Overall, the 2SFCA method produced better accessibility ratios. There is room for further improvement of the 2SFCA method-varying the radius of service area according to the type of provider or the type of neighborhood and determining the appropriate weight equation form-still warrant further study.

  12. Comparing farmer and measured assessments of soil quality in Tanzania: Do they align?

    Directory of Open Access Journals (Sweden)

    Allison C. Kelly

    2016-06-01

    Full Text Available Background: There is a wide gap between actual and potential yields for many crops in Sub-Saharan Africa (SSA. Experts identify poor soil quality as a primary constraint to increased agricultural productivity. Therefore, increasing agricultural productivity by improving soil quality is seen as a viable strategy to enhance food security. Yet adoption rates of programs focused on improving soil quality have generally been lower than expected [1], [2]. Results: We explore a seldom considered factor that may limit farmers’ demand for improved soil quality, namely, whether the farmers’ self-assessment of their soil quality match the assessments of soil scientists. In this paper, using data from the Tanzania National Panel Survey (TZNPS, part of the Living Standards Measurement Study – Integrated Surveys on Agriculture (LSMS-ISA, we compare farmers’ own assessments of soil quality with scientific measurements of soil quality from the Harmonized World Soil Database (HWSD. The study found a considerable “mismatch” and most notably, that 11.5 percent of survey households that reported having “good” soil quality are measured by scientific standards to have severely limited nutrient availability. Conclusion: Mismatches between scientific measurements and farmer assessments of soil quality may highlight a potential barrier for programs seeking to encourage farmers to adopt soil quality improvement activities.

  13. A Comparative Study of Simulated and Measured Gear-Flap Flow Interaction

    Science.gov (United States)

    Khorrami, Mehdi R.; Mineck, Raymond E.; Yao, Chungsheng; Jenkins, Luther N.; Fares, Ehab

    2015-01-01

    The ability of two CFD solvers to accurately characterize the transient, complex, interacting flowfield asso-ciated with a realistic gear-flap configuration is assessed via comparison of simulated flow with experimental measurements. The simulated results, obtained with NASA's FUN3D and Exa's PowerFLOW® for a high-fidelity, 18% scale semi-span model of a Gulfstream aircraft in landing configuration (39 deg flap deflection, main landing gear on and off) are compared to two-dimensional and stereo particle image velocimetry measurements taken within the gear-flap flow interaction region during wind tunnel tests of the model. As part of the bench-marking process, direct comparisons of the mean and fluctuating velocity fields are presented in the form of planar contour plots and extracted line profiles at measurement planes in various orientations stationed in the main gear wake. The measurement planes in the vicinity of the flap side edge and downstream of the flap trailing edge are used to highlight the effects of gear presence on tip vortex development and the ability of the computational tools to accurately capture such effects. The present study indicates that both computed datasets contain enough detail to construct a relatively accurate depiction of gear-flap flow interaction. Such a finding increases confidence in using the simulated volumetric flow solutions to examine the behavior of pertinent aer-odynamic mechanisms within the gear-flap interaction zone.

  14. Wind Turbine Rotor Simulation via CFD Based Actuator Disc Technique Compared to Detailed Measurement

    Directory of Open Access Journals (Sweden)

    Esmail Mahmoodi

    2015-10-01

    Full Text Available In this paper, a generalized Actuator Disc (AD is used to model the wind turbine rotor of the MEXICO experiment, a collaborative European wind turbine project. The AD model as a combination of CFD technique and User Defined Functions codes (UDF, so-called UDF/AD model is used to simulate loads and performance of the rotor in three different wind speed tests. Distributed force on the blade, thrust and power production of the rotor as important designing parameters of wind turbine rotors are focused to model. A developed Blade Element Momentum (BEM theory as a code based numerical technique as well as a full rotor simulation both from the literature are included into the results to compare and discuss. The output of all techniques is compared to detailed measurements for validation, which led us to final conclusions.

  15. Comparing different CFD wind turbine modelling approaches with wind tunnel measurements

    Science.gov (United States)

    Kalvig, Siri; Manger, Eirik; Hjertager, Bjørn

    2014-12-01

    The performance of a model wind turbine is simulated with three different CFD methods: actuator disk, actuator line and a fully resolved rotor. The simulations are compared with each other and with measurements from a wind tunnel experiment. The actuator disk is the least accurate and most cost-efficient, and the fully resolved rotor is the most accurate and least cost-efficient. The actuator line method is believed to lie in between the two ends of the scale. The fully resolved rotor produces superior wake velocity results compared to the actuator models. On average it also produces better results for the force predictions, although the actuator line method had a slightly better match for the design tip speed. The open source CFD tool box, OpenFOAM, was used for the actuator disk and actuator line calculations, whereas the market leading commercial CFD code, ANSYS/FLUENT, was used for the fully resolved rotor approach.

  16. A comparative study of satellite estimation for solar insolation in Albania with ground measurements

    Energy Technology Data Exchange (ETDEWEB)

    Mitrushi, Driada, E-mail: driadamitrushi@yahoo.com; Berberi, Pëllumb, E-mail: pellumb.berberi@gmail.com; Muda, Valbona, E-mail: vmuda@hotmail.com; Buzra, Urim, E-mail: rimibuzra@yahoo.com [Department of Engineering Physics, Faculty of Engineering Mathematics and Engineering Physics, Polytechnic University of Tirana, Tirana (Albania); Bërdufi, Irma, E-mail: irmaberdufi@gmail.com [Institute of Applied Nuclear Physics, Tirana University, Street “Th. Filipeu”, Tirana (Albania); Topçiu, Daniela, E-mail: topciudaniela@yahoo.com [Department of Physics, Faculty of Natural Physics, “Aleksander Xhuvani” University, Elbasan (Albania)

    2016-03-25

    The main objective of this study is to compare data provided by Database of NASA with available ground data for regions covered by national meteorological net NASA estimates that their measurements of average daily solar radiation have a root-mean-square deviation RMSD error of 35 W/m{sup 2} (roughly 20% inaccuracy). Unfortunately valid data from meteorological stations for regions of interest are quite rare in Albania. In these cases, use of Solar Radiation Database of NASA would be a satisfactory solution for different case studies. Using a statistical method allows to determine most probable margins between to sources of data. Comparison of mean insulation data provided by NASA with ground data of mean insulation provided by meteorological stations show that ground data for mean insolation results, in all cases, to be underestimated compared with data provided by Database of NASA. Converting factor is 1.149.

  17. Noninvasive xenon-133 measurements of cerebral blood flow using stationary detectors compared with dynamic emission tomography

    DEFF Research Database (Denmark)

    Schroeder, T; Vorstrup, S; Lassen, N A

    1986-01-01

    Repeated bedside measurements of CBF have been made possible by the recent development of a mobile unit with 10 stationary detectors using the intravenous xenon-133 method. To evaluate this technique, comparative CBF studies at rest and following the application of a cerebral vasodilatory stimulus...... (acetazolamide, 1 g i.v.) were performed with the mobile equipment and with xenon-133 single-photon emission inhalation tomography in patients with cerebrovascular disease. The CBF level and the flow response to acetazolamide as determined with the two methods were well correlated, although at low flow levels...

  18. Comparative discussion on some measurements of the atmospheric natural radioactivity and pollution with coal smoke particles

    International Nuclear Information System (INIS)

    Zoran, M.

    1977-01-01

    The results of measuring the natural radioactivity and coal smoke pollution are discussed for two sites in an industrial town, as well as for two heights at the same site, in connection with large scale and local atmospheric stability. The effects of the radiation fog upon the radon daughters acumulation near the ground are examined in some detail. By comparing the pollutant diurnal variations during two periods of similar atmospheric stability in autumn, respectively in winter, the contribution from the dwelling coal heating has been estimated to be about half of the total pollution in the town. (author)

  19. Changes in quality of life after elective surgery: an observational study comparing two measures.

    Science.gov (United States)

    Kronzer, Vanessa L; Jerry, Michelle R; Ben Abdallah, Arbi; Wildes, Troy S; McKinnon, Sherry L; Sharma, Anshuman; Avidan, Michael S

    2017-08-01

    Our main objective was to compare the change in a validated quality of life measure to a global assessment measure. The secondary objectives were to estimate the minimum clinically important difference (MCID) and to describe the change in quality of life by surgical specialty. This prospective cohort study included 7902 adult patients undergoing elective surgery. Changes in the Veterans RAND 12-Item Health Survey (VR-12), composed of a physical component summary (PCS) and a mental component summary (MCS), were calculated using preoperative and postoperative questionnaires. The latter also contained a global assessment question for quality of life. We compared PCS and MCS to the global assessment using descriptive statistics and weighted kappa. MCID was calculated using an anchor-based approach. Analyses were pre-specified and registered (NCT02771964). By the change in VR-12 scores, an equal proportion of patients experienced improvement and deterioration in quality of life (28% for PCS, 25% for MCS). In contrast, by the global assessment measure, 61% reported improvement, while only 10% reported deterioration. Agreement with the global assessment was slight for both PCS (kappa = 0.20, 57% matched) and MCS (kappa = 0.10, 54% matched). The MCID for the overall VR-12 score was approximately 2.5 points. Patients undergoing orthopedic surgery showed the most improvement in quality of life measures, while patients undergoing gastrointestinal/hepatobiliary or urologic surgery showed the most deterioration. Subjective global quality of life report does not agree well with a validated quality of life instrument, perhaps due to patient over-optimism.

  20. Funnel plots for comparing provider performance based on patient-reported outcome measures.

    Science.gov (United States)

    Neuburger, Jenny; Cromwell, David A; Hutchings, Andrew; Black, Nick; van der Meulen, Jan H

    2011-12-01

    Patient-reported outcome measures (PROMs) often produce skewed distributions of individual scores after a healthcare intervention. For health performance indicators derived from skewed distributions, funnel plots designed with symmetric control limits may increase the risk of false alarms about poor performance. To investigate the accuracy of funnel plots with symmetric control limits when comparing provider performance based on PROMs. The authors used a database containing condition-specific PROMs for 17,453 hip replacements and 7656 varicose vein procedures performed by providers in the English NHS. The mean postoperative PROM score, adjusted for patient characteristics, was used as the measure of performance. To compare performance, symmetric 99.8% control limits were calculated on funnel plots, 3 SDs away from the overall mean on either side. These were compared to control limits derived directly from percentiles of simulated (bootstrap) distributions of mean scores. The simulated control limits on funnel plots for both procedures were asymmetric. The empirical probability of falling outside the symmetric 99.8% 'poor performance' control limit was inflated from the stipulated rate of 0.1% to 0.2-0.3% for provider sample sizes of up to 150 procedures. The authors observed that, out of 237 providers of hip replacement, eight had adjusted mean scores that exceeded the symmetric 'poor performance' limit compared with only five that exceeded the corresponding simulated limit. In other words, three (1.3%) were differently classified. For varicose vein surgery, five out of 160 providers exceeded the symmetric limit and four exceeded the simulated limit, that is, 1 (0.6%) was differently classified. When designing funnel plots for comparisons of provider performance based on highly skewed data, the use of simulated control limits should be considered.

  1. Comparative performance of CO2 measuring methods: marine aquaculture recirculation system application

    Science.gov (United States)

    Pfeiffer, T.J.; Summerfelt, S.T.; Watten, B.J.

    2011-01-01

    Many methods are available for the measurement of dissolved carbon dioxide in an aqueous environment. Standard titration is the typical field method for measuring dissolved CO2 in aquaculture systems. However, titrimetric determination of dissolved CO2 in marine water aquaculture systems is unsuitable because of the high dissolved solids, silicates, and other dissolved minerals that interfere with the determination. Other methods used to measure dissolved carbon dioxide in an aquaculture water included use of a wetted CO2 probe analyzer, standard nomographic methods, and calculation by direct measurements of the water's pH, temperature, and alkalinity. The determination of dissolved CO2 in saltwater based on partial pressure measurements and non-dispersive infra-red (NDIR) techniques with a CO2 gas analyzer are widely employed for oceanic surveys of surface ocean CO2 flux and are similar to the techniques employed with the head space unit (HSU) in this study. Dissolved carbon dioxide (DC) determination with the HSU using a infra-red gas analyzer (IRGA) was compared with titrimetric, nomographic, calculated, and probe measurements of CO2 in freshwater and in saltwater with a salinity ranging from 5.0 to 30 ppt, and a CO2 range from 8 to 50 mg/L. Differences in CO2 measurements between duplicate HSUs (0.1–0.2 mg/L) were not statistically significant different. The coefficient of variation for the HSU readings averaged 1.85% which was better than the CO2 probe (4.09%) and that for the titrimetric method (5.84%). In all low, medium and high salinity level trials HSU precision was good, averaging 3.39%. Differences existed between comparison testing of the CO2 probe and HSU measurements with the CO2 probe readings, on average, providing DC estimates that were higher than HSU estimates. Differences between HSU and titration based estimates of DC increased with salinity and reached a maximum at 32.2 ppt. These differences were statistically significant (P < 0.05) at all

  2. Comparing electron tomography and HRTEM slicing methods as tools to measure the thickness of nanoparticles

    International Nuclear Information System (INIS)

    Alloyeau, D.; Ricolleau, C.; Oikawa, T.; Langlois, C.; Le Bouar, Y.; Loiseau, A.

    2009-01-01

    Nanoparticles' morphology is a key parameter in the understanding of their thermodynamical, optical, magnetic and catalytic properties. In general, nanoparticles, observed in transmission electron microscopy (TEM), are viewed in projection so that the determination of their thickness (along the projection direction) with respect to their projected lateral size is highly questionable. To date, the widely used methods to measure nanoparticles thickness in a transmission electron microscope are to use cross-section images or focal series in high-resolution transmission electron microscopy imaging (HRTEM 'slicing'). In this paper, we compare the focal series method with the electron tomography method to show that both techniques yield similar particle thickness in a range of size from 1 to 5 nm, but the electron tomography method provides better statistics since more particles can be analyzed at one time. For this purpose, we have compared, on the same samples, the nanoparticles thickness measurements obtained from focal series with the ones determined from cross-section profiles of tomograms (tomogram slicing) perpendicular to the plane of the substrate supporting the nanoparticles. The methodology is finally applied to the comparison of CoPt nanoparticles annealed ex situ at two different temperatures to illustrate the accuracy of the techniques in detecting small particle thickness changes.

  3. Comparing electron tomography and HRTEM slicing methods as tools to measure the thickness of nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Alloyeau, D., E-mail: alloyeau.damien@gmail.com [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Laboratoire d' Etude des Microstructures - ONERA/CNRS, UMR 104, B.P. 72, 92322 Chatillon (France); Ricolleau, C. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Oikawa, T. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); JEOL (Europe) SAS, Espace Claude Monet, 1 Allee de Giverny, 78290 Croissy-sur-Seine (France); Langlois, C. [Laboratoire Materiaux et Phenomenes Quantiques, Universite Paris 7/CNRS, UMR 7162, 2 Place Jussieu, 75251 Paris (France); Le Bouar, Y.; Loiseau, A. [Laboratoire d' Etude des Microstructures - ONERA/CNRS, UMR 104, B.P. 72, 92322 Chatillon (France)

    2009-06-15

    Nanoparticles' morphology is a key parameter in the understanding of their thermodynamical, optical, magnetic and catalytic properties. In general, nanoparticles, observed in transmission electron microscopy (TEM), are viewed in projection so that the determination of their thickness (along the projection direction) with respect to their projected lateral size is highly questionable. To date, the widely used methods to measure nanoparticles thickness in a transmission electron microscope are to use cross-section images or focal series in high-resolution transmission electron microscopy imaging (HRTEM 'slicing'). In this paper, we compare the focal series method with the electron tomography method to show that both techniques yield similar particle thickness in a range of size from 1 to 5 nm, but the electron tomography method provides better statistics since more particles can be analyzed at one time. For this purpose, we have compared, on the same samples, the nanoparticles thickness measurements obtained from focal series with the ones determined from cross-section profiles of tomograms (tomogram slicing) perpendicular to the plane of the substrate supporting the nanoparticles. The methodology is finally applied to the comparison of CoPt nanoparticles annealed ex situ at two different temperatures to illustrate the accuracy of the techniques in detecting small particle thickness changes.

  4. Cardiac Output Measurements in Septic Patients: Comparing the Accuracy of USCOM to PiCCO

    Directory of Open Access Journals (Sweden)

    Sophia Horster

    2012-01-01

    Full Text Available USCOM is an ultrasound-based method which has been accepted for noninvasive hemodynamic monitoring in various clinical conditions (USCOM, Ultrasonic cardiac output monitoring. The present study aimed at comparing the accuracy of the USCOM device with that of the thermodilution technique in patients with septicemia. We conducted a prospective observational study in a medical but noncardiological ICU of a university hospital. Septic adult patients (median age 55 years, median SAPS-II-Score 43 points on mechanical ventilation and catecholamine support were monitored with USCOM and PiCCO (=70. Seventy paired left-sided CO measurements (transaortic access = COUS-A were obtained. The mean COUS-A were 6.55 l/min (±2.19 versus COPiCCO 6.5 l/min (±2.18. The correlation coefficient was =0.89. Comparison by Bland-Altman analysis revealed a bias of −0.36 l/min (±0.99 l/min leading to a mean percentage error of 29%. USCOM is a feasible and rapid method to evaluate CO in septic patients. USCOM does reliably represent CO values as compared to the reference technique based on thermodilution (PiCCO. It seems to be appropriate in situations where CO measurements are most pertinent to patient management.

  5. Comparing frailty measures in their ability to predict adverse outcome among older residents of assisted living

    Directory of Open Access Journals (Sweden)

    Hogan David B

    2012-09-01

    Full Text Available Abstract Background Few studies have directly compared the competing approaches to identifying frailty in more vulnerable older populations. We examined the ability of two versions of a frailty index (43 vs. 83 items, the Cardiovascular Health Study (CHS frailty criteria, and the CHESS scale to accurately predict the occurrence of three outcomes among Assisted Living (AL residents followed over one year. Methods The three frailty measures and the CHESS scale were derived from assessment items completed among 1,066 AL residents (aged 65+ participating in the Alberta Continuing Care Epidemiological Studies (ACCES. Adjusted risks of one-year mortality, hospitalization and long-term care placement were estimated for those categorized as frail or pre-frail compared with non-frail (or at high/intermediate vs. low risk on CHESS. The area under the ROC curve (AUC was calculated for select models to assess the predictive accuracy of the different frailty measures and CHESS scale in relation to the three outcomes examined. Results Frail subjects defined by the three approaches and those at high risk for decline on CHESS showed a statistically significant increased risk for death and long-term care placement compared with those categorized as either not frail or at low risk for decline. The risk estimates for hospitalization associated with the frailty measures and CHESS were generally weaker with one of the frailty indices (43 items showing no significant association. For death and long-term care placement, the addition of frailty (however derived or CHESS significantly improved on the AUC obtained with a model including only age, sex and co-morbidity, though the magnitude of improvement was sometimes small. The different frailty/risk models did not differ significantly from each other in predicting mortality or hospitalization; however, one of the frailty indices (83 items showed significantly better performance over the other measures in predicting long

  6. Comparing frailty measures in their ability to predict adverse outcome among older residents of assisted living.

    Science.gov (United States)

    Hogan, David B; Freiheit, Elizabeth A; Strain, Laurel A; Patten, Scott B; Schmaltz, Heidi N; Rolfson, Darryl; Maxwell, Colleen J

    2012-09-14

    Few studies have directly compared the competing approaches to identifying frailty in more vulnerable older populations. We examined the ability of two versions of a frailty index (43 vs. 83 items), the Cardiovascular Health Study (CHS) frailty criteria, and the CHESS scale to accurately predict the occurrence of three outcomes among Assisted Living (AL) residents followed over one year. The three frailty measures and the CHESS scale were derived from assessment items completed among 1,066 AL residents (aged 65+) participating in the Alberta Continuing Care Epidemiological Studies (ACCES). Adjusted risks of one-year mortality, hospitalization and long-term care placement were estimated for those categorized as frail or pre-frail compared with non-frail (or at high/intermediate vs. low risk on CHESS). The area under the ROC curve (AUC) was calculated for select models to assess the predictive accuracy of the different frailty measures and CHESS scale in relation to the three outcomes examined. Frail subjects defined by the three approaches and those at high risk for decline on CHESS showed a statistically significant increased risk for death and long-term care placement compared with those categorized as either not frail or at low risk for decline. The risk estimates for hospitalization associated with the frailty measures and CHESS were generally weaker with one of the frailty indices (43 items) showing no significant association. For death and long-term care placement, the addition of frailty (however derived) or CHESS significantly improved on the AUC obtained with a model including only age, sex and co-morbidity, though the magnitude of improvement was sometimes small. The different frailty/risk models did not differ significantly from each other in predicting mortality or hospitalization; however, one of the frailty indices (83 items) showed significantly better performance over the other measures in predicting long-term care placement. Using different

  7. Evaluating task modification as an objective measure of functional limitation: repeatability and comparability.

    Science.gov (United States)

    Manini, Todd M; Cook, Summer B; VanArnam, Tom; Marko, Moshe; Ploutz-Snyder, Lori

    2006-07-01

    Modification of everyday tasks in older adults is associated with risk of deleterious health outcomes. The purpose of this study was to develop a task modification scale to examine its reliability and comparability to timed performance and common measures of physical function and impairment. Eighty-two (21 men, 61 women) older adults (74.4 +/- 8.2 years) were observed performing a chair rise (sitting heights: 43 cm, 38 cm, and 30 cm), stair ascent/descent, and kneel and supine rise tasks. Six hierarchically ranked categories (0-5) of modification were created for each task and then summed across tasks (summary modification [MOD] score: range 0-35). Comparisons were made with timed performance, knee extension strength, single-leg balance, self-reported function, five chair stands, and gait speed. Inter-rater reliability (intra-class correlation = 0.98) and participant repeatability (intra-class correlation = 0.92) of the MOD score were excellent. Ninety-six percent of participants modified at least one task (MOD score: 10.5 +/- 7.51, range 0-27). After adjusting for task modification, timed performance showed a lower association with gait speed (time vs MOD score, semipartial r2 = 0.31 vs 0.68), strength (semipartial r2 = 0.14 vs 0.65), and single-leg balance (semipartial r2 = 0.10 vs 0.40) than did the MOD score. The MOD score showed higher correlations with muscle strength and balance impairment than did other measures of functional limitation such as gait speed, time to complete five chair stands, and self-reported physical function. Documentation of task modification is reliable across raters and repeatable within participants; in addition, it compares well with other measures of physical function and impairment. Task modification reveals important and intuitive information regarding physical limitation, and deserves greater attention.

  8. Comparing computer adaptive and curriculum-based measures of math in progress monitoring.

    Science.gov (United States)

    Shapiro, Edward S; Dennis, Minyi Shih; Fu, Qiong

    2015-12-01

    The purpose of the study was to compare the use of a Computer Adaptive Test and Curriculum-Based Measurement in the assessment of mathematics. This study also investigated the degree to which slope or rate of change predicted student outcomes on the annual state assessment of mathematics above and beyond scores of single point screening assessments (i.e., the computer adaptive test or the CBM assessment just before the administration of the state assessment). Repeated measurement of mathematics once per month across a 7-month period using a Computer Adaptive Test (STAR-Math) and Curriculum-Based Measurement (CBM, AIMSweb Math Computation, AIMSweb Math Concepts/Applications) was collected for a maximum total of 250 third, fourth, and fifth grade students. Results showed STAR-Math in all 3 grades and AIMSweb Math Concepts/Applications in the third and fifth grades had primarily linear growth patterns in mathematics. AIMSweb Math Computation in all grades and AIMSweb Math Concepts/Applications in Grade 4 had decelerating positive trends. Predictive validity evidence showed the strongest relationships were between STAR-Math and outcomes for third and fourth grade students. The blockwise multiple regression by grade revealed that slopes accounted for only a very small proportion of additional variance above and beyond what was explained by the scores obtained on a single point of assessment just prior to the administration of the state assessment. (c) 2015 APA, all rights reserved).

  9. Comparing TACOM scores with subjective workload scores measured by NASA-TLX technique

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Kyun; Jung, Won Dea [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    It is a well-known fact that a large portion of human performance related problems was attributed to the complexity of tasks. Therefore, managing the complexity of tasks is a prerequisite for safety-critical systems such as nuclear power plants (NPPs), because the consequence of a degraded human performance could be more severe than in other systems. From this concern, it is necessary to quantify the complexity of emergency tasks that are stipulated in procedures, because most tasks of NPPs have been specified in the form of procedures. For this reason, Park et al. developed a task complexity measure called TACOM. In this study, in order to confirm the validity of the TACOM measure, subjective workload scores that were measured by the NASA-TLX technique were compared with the associated TACOM scores. To do this, 23 emergency tasks of the reference NPPs were selected, and then subjective workload scores for these emergency tasks were quantified by 18 operators who had a sufficient knowledge about emergency operations.

  10. Comparing Pore-scale and Macro-scale Capillary Pressure Measurements Using a Two- dimensional Micromodel

    Science.gov (United States)

    Brown, K. I.; Porter, M. L.; Wildenschild, D.

    2007-12-01

    Capillary pressure plays a critical role in multiphase flow and transport in porous media. At the pore scale, capillary pressure is defined by Laplace's law which states that capillary pressure is a function of surface tension, contact angle and curvature. This study focuses on imaging and estimating pore scale properties that determine capillary pressure. Drainage and imbibition experiments for a NAPL-water system are conducted in a two-dimensional micro-scale porous medium. High resolution images of the phase distributions and associated interfaces within the pores are collected during the experiments. Images are taken at a rate of approximately 50 frames per second with a resolution between 1-10 ìm per pixel. In addition, the pressure in each phase is measured with a transducer outside the porous medium, and pressure-saturation curves are plotted from the data. We will attempt to use Laplace's Law to estimate the average pressure inside the porous medium based on measured curvatures. The two pressure values (measured outside the system versus calculated via Laplace's Law) will be compared. The images will allow for investigation of pore scale properties during dynamic flow conditions, as well as static conditions, and importantly, allow for comparison among the two situations. Specifically, relaxation of menisci interfaces and resulting changes in interface curvature, and thus capillary pressure, will be correlated to variations in system properties such as fluid-fluid viscosities and flow rates.

  11. Wound debridement: Comparative reliability of three methods for measuring fibrin percentage in chronic wounds.

    Science.gov (United States)

    Laplaud, Anne-Laure; Blaizot, Xavier; Gaillard, Cathy; Morice, Aurore; Lebreuilly, Ingrid; Clément, Cécile; Parienti, Jean-Jacques; Dompmartin, Anne

    2010-01-01

    The purpose of this study was to examine the intra- and interrater reliability of three methods to measure the percentage of fibrin within a wound, hence reflecting wound debridement. The three methods include visual assessment, a portable wound measurement system (PWMS) Visitrak(R), and a computerized planimetry software Canvas(R). The main objective was to compare the computerized planimetry with visual analysis. For each wound, a series of two repeated recordings of fibrin percentage based on the same Day 1 photograph at Day 8 and Day 15, respectively, was assessed by four evaluators using the two methods. Additional objectives consisted in the assessment of the inter-rater reliability of computerized planimetry and PWMS to assess fibrin percentage and total surface area. Twenty-four patients were included for a total of 31 wounds. Intraclass correlation coefficient revealed improved reproducibility and repeatability of computerized planimetry. The reproducibility of computerized planimetry was better than PWMS when measuring the percentage of fibrin and total wound area. Because average visual estimations were very close to the computerized planimetry, bedside evaluation of fibrin percentage and wound debridement was considered as reliable, and consequently a valid technique for daily practice. PWMS proved to be less convenient, owing to difficulties in identifying fibrin margins. The higher intra and interrater reliability of computerized planimetry probably reflected the fact that subjective clinical assessment and objective calculation of percentages were mandatory for correct wound evaluation. Therefore, digital image analysis was considered as an accurate method for double-blind and multicentric trials.

  12. [Tono-pen versus manometer. Comparative measurements of intraocular pressure in human cadaver eyes].

    Science.gov (United States)

    Hessemer, V; Rössler, R; Jacobi, K W

    1989-07-01

    A new hand-held tonometer, the Tono-Pen (TP), was compared with a Statham membrane manometer (MAN). The TP is a pen-sized Mackay-Marg tonometer with electronic signal analysis and digital pressure display. Comparative measurements of intra-ocular pressure (IOP) were performed on six cadavers (12 eyes in situ), 3-6 hours after death. The IOP was changed in 5 to 10 mm Hg steps in a range between 0 and 60 mm Hg by an infusion system. As compared to the manometrically determined IOP, the TP gave small overestimation of IOP below 17 mm Hg and a small underestimation above 17 mm Hg (maximum deviation 2.5 mm Hg). The mean values of 29.9 (TP) and 30.4 mm Hg (MAN) were not significantly different (p greater than 0.05, analysis of variance). The correlation coefficient was 0.99. The relationship between TP (y axis) and MAN (x axis) pressure readings is characterized exactly by a slightly curvilinear graph (y = 0.82x + 0.0002x2 + 2.52; mm Hg). This may be approximated by a regression line with a slope of 0.94, a y intercept of 1.46 mm Hg and a standard deviation of the TP readings in relation to the regression line of 2.36 mm Hg. In conclusion, the good agreement between TP and MAN pressure readings is superior to the recently described agreement between TP and Goldmann tonometer readings.

  13. Measurement of comparative advantages of processed food sector of Serbia in the increasing the export

    Directory of Open Access Journals (Sweden)

    Ignjatijević Svetlana

    2014-01-01

    Full Text Available The subject of this research is to analyse the comparative advantages of export of processed food sector, in order to define the position of the processed food sector in Serbia in compare to the Danube region and highlight the products that were and will be the main exporting agricultural product of Serbia. In this research, we have applied the following indexes: RXA, RTA, ln RXA, RC, RCA, LFI, GL, Sm. We have examined the movement of the index for the period 2005 - 2011th year. We have investigated the existence of correlations RCA index of processed food sectors with the application of the Pearson and Spearman index determined as RCA variable mutual co-variant. We found that following products showed an increase of comparative advantage in export as measured by the Balassa index: milk products, cheese and curd, groats and meal of other cereals, preparations of cereals, flour, starch, vegetables, roots and tubers, processed, prepared and Fruit products, sugar, molasses and honey, chocolate and other food preparations with cocoa, animal food (including un milled cereals, edible products and preparations, alcoholic beverages, non-alcoholic beverages, solid vegetable fats, oils, 'soft' and animal and vegetable fats.

  14. Comparable Measures of Accessibility to Public Transport Using the General Transit Feed Specification

    Directory of Open Access Journals (Sweden)

    Jinjoo Bok

    2016-03-01

    Full Text Available Public transport plays a critical role in the sustainability of urban settings. The mass mobility and quality of urban lives can be improved by establishing public transport networks that are accessible to pedestrians within a reasonable walking distance. Accessibility to public transport is characterized by the ease with which inhabitants can reach means of transportation such as buses or metros. By measuring the degree of accessibility to public transport networks using a common data format, a comparative study can be conducted between different cities or metropolitan areas with different public transit systems. The General Transit Feed Specification (GTFS by Google Developers allows this by offering a common format based on text files and sharing the data set voluntarily produced and contributed by the public transit agencies of many participating cities around the world. This paper suggests a method to assess and compare public transit accessibility in different urban areas using the GTFS feed and demographic data. To demonstrate the value of the new method, six examples of metropolitan areas and their public transit accessibility are presented and compared.

  15. Criterion validity of measures of perceived relative harm of e-cigarettes and smokeless tobacco compared to cigarettes.

    Science.gov (United States)

    Persoskie, Alexander; Nguyen, Anh B; Kaufman, Annette R; Tworek, Cindy

    2017-04-01

    Beliefs about the relative harmfulness of one product compared to another (perceived relative harm) are central to research and regulation concerning tobacco and nicotine-containing products, but techniques for measuring such beliefs vary widely. We compared the validity of direct and indirect measures of perceived harm of e-cigarettes and smokeless tobacco (SLT) compared to cigarettes. On direct measures, participants explicitly compare the harmfulness of each product. On indirect measures, participants rate the harmfulness of each product separately, and ratings are compared. The U.S. Health Information National Trends Survey (HINTS-FDA-2015; N=3738) included direct measures of perceived harm of e-cigarettes and SLT compared to cigarettes. Indirect measures were created by comparing ratings of harm from e-cigarettes, SLT, and cigarettes on 3-point scales. Logistic regressions tested validity by assessing whether direct and indirect measures were associated with criterion variables including: ever-trying e-cigarettes, ever-trying snus, and SLT use status. Compared to the indirect measures, the direct measures of harm were more consistently associated with criterion variables. On direct measures, 26% of adults rated e-cigarettes as less harmful than cigarettes, and 11% rated SLT as less harmful than cigarettes. Direct measures appear to provide valid information about individuals' harm beliefs, which may be used to inform research and tobacco control policy. Further validation research is encouraged. Published by Elsevier Ltd.

  16. Comparative study of methods for blood flow measurement within transverse sinuses by using MR

    International Nuclear Information System (INIS)

    Gao Gejun; Feng Xiaoyuan; Yang Bojie; Geng Daoying

    2003-01-01

    Objective: To assess the accuracy of two-dimensional phase contrast (2D-PC) MR method for blood flow measurement within transverse sinuses by comparing this method with cine phase contrast (cine-PC) MR and Doppler in volunteers and patients. Methods: (1) A total of 12 transverse sinuses were examined in 8 healthy volunteers. 2D-PC MR and cine-PC MR were used respectively to measure the transverse area of flow, the flow velocities, and the volumetric flow rates in the same position in every transverse sinus. Paired t-test was used for comparison between the results determined by 2D-PC MR and that determined by cine-PC MR. (2) A total of 6 transverse sinuses were examined in 5 patients who needed operation. 2D-PC MR was used to determine the blood flow velocity of transverse sinus before operation, and Doppler was used to determine the blood flow velocity of the same transverse sinus during operation. The linear regression analysis was used for statistical analysis. Results: (1) Statistical analysis indicated that there were no significant difference among the transverse area of flow (t = -1.106, P = 0.293), the flow velocities (t = 0.262, P = 0.798), and the volumetric flow rates (t = 0.439, P = 0.669) measured by using 2D-PC MR and cine PC MR, respectively. (2) The correlation between flow velocities determined by 2D-PC MR imaging before operation and that determined by Doppler during operation was in excellent agreement (Y-circumflex = 1.303 x + 0.62, r 2 = 0.88). Conclusion: 2D-PC MR may be a practical convenient method for blood flow measurement within transverse sinuses system

  17. Comparing two forms of a childhood perspective-taking measure using CFA and IRT.

    Science.gov (United States)

    Carey, Jasmine M; Cassels, Tracy G

    2013-09-01

    Deficits in perspective-taking ability have been linked to social problems associated with disorders such as autism spectrum disorders (ASD) and conduct disorder. Even subtle deficits in perspective-taking are related to social adjustment and moral development. A common measure of perspective-taking abilities in children is the "Reading the Mind in the Eyes Task" ("Eyes task"; Baron-Cohen, Wheelwright, Spong, Scahill, & Lawson, 2001). The Eyes task was primarily developed for use in identifying individuals with ASDs, while its function with nonclinical populations has not been clearly addressed. Additionally, it is unknown whether the Eyes task can be used to measure specific deficits or abilities in the cognitive or emotional components of perspective-taking. In this article we assessed the structure and function of the Eyes task and an open ended or generative format of the same task (Generative Eyes Task; GET) found to measure emotional perspective-taking specifically. Confirmatory factor analyses found the traditional Eyes task to have the assumed single factor structure, while the GET has a clear 2-factor structure corresponding to emotionally valenced or neutral items. The Eyes task and the GET were also compared using item response theory. The Eyes task provided the most measurement accuracy at 2 standard deviations below the mean making it most accurate for populations with severe deficits, while the GET was most accurate at the mean level of perspective-taking. Based on these analyses, we conclude that the GET is more appropriate for use in nonclinical populations and when emotional perspective-taking abilities are of interest.

  18. Spectroscopic noninvasive measurement of hemoglobin compared with capillary and venous values in neonates.

    Science.gov (United States)

    Rabe, H; Alvarez, R Fernandez; Whitfield, T; Lawson, F; Jungmann, H

    2010-06-01

    Venepuncture-related blood loss is a common cause of neonatal anemia. Currently, this is the only way to obtain hemoglobin levels. This causes distress for the infant but can also lead to the need for blood transfusions. Recently, a new technique for measuring hemoglobin levels non-invasively has been developed to reduce iatrogenic blood loss and pain. To compare hemoglobin levels obtained using a transcutaneous spectroscopic device (Mediscan 2000, MBR Optical Systems, Wuppertal, Germany) with venous or capillary blood samples in neonates. Single-center prospective cohort study of term and preterm infants. The white light spectroscopic device was placed on the forearm for 60 s to measure hemoglobin content within 4 h of venous or capillary blood sampling. Pain reactions of the infants were assessed by using a neonatal pain assessment tool. Results were analyzed by Bland-Altman comparison and Wilcoxon signed-rank test. 80 infants (mean gestational age 29.8 +/- 3.8 weeks, mean birth weight 1,300 +/- 690 g) were enrolled into the study. A total of 313 spectroscopic recordings within 2 h of a clinically indicated blood sample (181 capillary, 142 venous) were taken. The correlation coefficient R(2) was 0.96 for capillary/spectroscopic and 0.99 for venous/spectroscopic pairs. Pain scores were significantly less for the spectroscopic measurements (p < 0.01). The results show good correlation between the hemoglobin blood levels and spectroscopic measurements. The slightly lower correlation coefficient for the capillary samples demonstrates a naturally higher variance in these values due to the laboratory method.

  19. A dual tracer ratio method for comparative emission measurements in an experimental dairy housing

    Science.gov (United States)

    Mohn, Joachim; Zeyer, Kerstin; Keck, Margret; Keller, Markus; Zähner, Michael; Poteko, Jernej; Emmenegger, Lukas; Schrade, Sabine

    2018-04-01

    Agriculture, and in particular dairy farming, is an important source of ammonia (NH3) and non-carbon dioxide greenhouse gas (GHG) emissions. This calls for the development and quantification of effective mitigation strategies. Our study presents the implementation of a dual tracer ratio method in a novel experimental dairy housing with two identical, but spatially separated housing areas. Modular design and flexible floor elements allow the assessment of structural, process engineering and organisational abatement measures at practical scale. Thereby, the emission reduction potential of specific abatement measures can be quantified in relation to a reference system. Emissions in the naturally ventilated housing are determined by continuous dosing of two artificial tracers (sulphur hexafluoride SF6, trifluoromethylsulphur pentafluoride SF5CF3) and their real-time detection in the ppt range with an optimized GC-ECD method. The two tracers are dosed into different experimental sections, which enables the independent assessment of both housing areas. Mass flow emissions of NH3 and GHGs are quantified by areal dosing of tracer gases and multipoint sampling as well as real-time analysis of both tracer and target gases. Validation experiments demonstrate that the technique is suitable for both areal and point emission sources and achieves an uncertainty of less than 10% for the mass emissions of NH3, methane (CH4) and carbon dioxide (CO2), which is superior to other currently available methods. Comparative emission measurements in this experimental dairy housing will provide reliable, currently unavailable information on emissions for Swiss dairy farming and demonstrate the reduction potential of mitigation measures for NH3, GHGs and potentially other pollutants.

  20. Pulse oximetry measures a lower heart rate at birth compared with electrocardiography.

    Science.gov (United States)

    van Vonderen, Jeroen J; Hooper, Stuart B; Kroese, Jacco K; Roest, Arno A W; Narayen, Ilona C; van Zwet, Erik W; te Pas, Arjan B

    2015-01-01

    To examine the effect of time after birth on heart rate (HR) measured by pulse oximetry (PO) (HRPO) and electrocardiography (ECG) (HRECG). HRECG and HRPO (collected at maximum sensitivity) were assessed in 53 term and preterm infants at birth. ECG electrodes and a PO sensor were attached as soon as possible and HRECG and HRPO were compared every 30 seconds from 1-10 minutes after birth. Data were compared using a Wilkinson signed-rank test. Clinical relevance (eg, HR <100 beats per minute [bpm] was tested using a McNemar test). Seven hundred fifty-five data pairs were analyzed. Median (IQR) gestational age was 37 (31-39) weeks. Mean (SD) starting time of PO and ECG data collection was 99 (33) vs 82 (26) seconds after birth (P = .001). In the first 2 minutes after birth, HRPO was significantly lower compared with HRECG (94 (67-144) vs 150 (91-153) bpm at 60 seconds (P < .05), 81 (60-109) vs 148 (83-170) bpm at 90 seconds (P < .001) and 83 (67-145) vs 158 (119-176) at 120 seconds (P < .001). A HR <100 bpm was more frequently observed with a PO than ECG in the first 2 minutes (64% vs 27% at 60 seconds (P = .05), 56% vs 26% at 90 seconds (P < .05) and 53% vs 21% at 120 seconds (P < .05). HR by ECG was verified by ultrasound for outflow from a subset of infants. In infants at birth, HRPO is significantly lower compared with ECG with clinically important differences in the first minutes. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Differences in neutral foot positions when measured barefoot compared to in shoes with varying stiffnesses.

    Science.gov (United States)

    Shultz, R; Birmingham, T B; Jenkyn, T R

    2011-12-01

    This study examined the absolute differences in neutral positions of the joints of the foot with different footwear. This addresses the question of whether separate static trials should be collected for each footwear condition to establish neutral positions. A multi-segment kinematic foot model and optical motion analysis system measured four inter-segmental joints of the foot: (1) hindfoot-to-midfoot in the frontal plane, (2) forefoot-to-midfoot in the frontal plane, (3) hallux-to-forefoot in the sagittal plane, and (4) the height-to-length ratio of the medial longitudinal arch. Barefoot was compared to three shoe condition using Nike Free trainers of varying longitudinal torsional stiffness in ten male volunteers. There was high variability both within subjects and shoe conditions. Shoes in general tended to raise the medial longitudinal arch and dorsiflex the hallux compared to barefoot condition. For the hallux, a minimum important difference of 5° or more was found between shoe conditions and the barefoot condition for majority of the subjects in all three shoe conditions (90% for control, 60% for least stiff, 50% for most stiff). This was less for the frontal plane inter-segmental joints of the foot where 50% of the subjects experience a change above 5° for at least one of the conditions. The choice of using condition-specific neutral trials versus a single common neutral trials should be considered carefully. A single common trial allows for differences in absolute joint angles to be compared between footwear conditions. This can be important clinically to determine whether a joint is approaching its end-of-range and therefore at risk of injury. Several condition-specific neutral trials allows for subtleties in kinematic waveforms to be better compared between conditions, since absolute shifts in joint angles due to changing neutral position are removed and the waveforms are better aligned. Copyright © 2011. Published by Elsevier Ltd.

  2. A comparative study of PCA, SIMCA and Cole model for classification of bioimpedance spectroscopy measurements.

    Science.gov (United States)

    Nejadgholi, Isar; Bolic, Miodrag

    2015-08-01

    Due to safety and low cost of bioimpedance spectroscopy (BIS), classification of BIS can be potentially a preferred way of detecting changes in living tissues. However, for longitudinal datasets linear classifiers fail to classify conventional Cole parameters extracted from BIS measurements because of their high variability. In some applications, linear classification based on Principal Component Analysis (PCA) has shown more accurate results. Yet, these methods have not been established for BIS classification, since PCA features have neither been investigated in combination with other classifiers nor have been compared to conventional Cole features in benchmark classification tasks. In this work, PCA and Cole features are compared in three synthesized benchmark classification tasks which are expected to be detected by BIS. These three tasks are classification of before and after geometry change, relative composition change and blood perfusion in a cylindrical organ. Our results show that in all tasks the features extracted by PCA are more discriminant than Cole parameters. Moreover, a pilot study was done on a longitudinal arm BIS dataset including eight subjects and three arm positions. The goal of the study was to compare different methods in arm position classification which includes all three synthesized changes mentioned above. Our comparative study on various classification methods shows that the best classification accuracy is obtained when PCA features are classified by a K-Nearest Neighbors (KNN) classifier. The results of this work suggest that PCA+KNN is a promising method to be considered for classification of BIS datasets that deal with subject and time variability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Stakeholder engagement in comparative effectiveness research: how will we measure success?

    Science.gov (United States)

    Lavallee, Danielle C; Williams, Carla J; Tambor, Ellen S; Deverka, Patricia A

    2012-09-01

    Stakeholder engagement in comparative effectiveness research continues to gain national attention. While various methods are used to gather stakeholder expertise and form recommendations, evaluation of the stakeholder experience is often missing. The lack of evaluation prohibits assessing how effective and meaningful engagement practices are for enhancing research efforts and limits the ability to identify areas for future improvement. We propose that an evaluation plan of engagement processes be developed before stakeholder involvement begins and be required as part of a request for proposal or research grant where stakeholder input is being sought. Furthermore, we recommend the inclusion of six meta-criteria that represent normative goals of multiple studies: respect, trust, legitimacy, fairness, competence and accountability. To aid in the development of future evaluations, we have developed definitions for and matched specific examples of measuring each meta-criterion to serve a guide for others in the field.

  4. Comparing Laser Interferometry and Atom Interferometry Approaches to Space-Based Gravitational-Wave Measurement

    Science.gov (United States)

    Baker, John; Thorpe, Ira

    2012-01-01

    Thoroughly studied classic space-based gravitational-wave missions concepts such as the Laser Interferometer Space Antenna (LISA) are based on laser-interferometry techniques. Ongoing developments in atom-interferometry techniques have spurred recently proposed alternative mission concepts. These different approaches can be understood on a common footing. We present an comparative analysis of how each type of instrument responds to some of the noise sources which may limiting gravitational-wave mission concepts. Sensitivity to laser frequency instability is essentially the same for either approach. Spacecraft acceleration reference stability sensitivities are different, allowing smaller spacecraft separations in the atom interferometry approach, but acceleration noise requirements are nonetheless similar. Each approach has distinct additional measurement noise issues.

  5. Comparing the physics reach of detectors in measuring CP violating angle β

    International Nuclear Information System (INIS)

    Toki, W.; Hassard, J.F.

    1993-01-01

    There have been attempts in the past to make quantitative comparison among present and proposed experiments seeking to measure the internal angles of the CKM unitarity triangle. The best known, which the authors shall call the Harrison Plot, puts the attainable error in sin (2β) against the year that error might be reached. Since there is huge uncertainty in the luminosity profiles of the proposed accelerators, the slope of these curves is recognized to be suspect. Furthermore, this representation makes no statement about the relative sizes of efficiency, dilution and number of events which determine the error. Here the authors present a complementary representation which allows a simple comparisons to be made, and which can be later extended to accommodate systematic errors and contributions to, say, the efficiencies, to be compared

  6. Comparative analysis of two methods for measuring sales volumes during malaria medicine outlet surveys.

    Science.gov (United States)

    Patouillard, Edith; Kleinschmidt, Immo; Hanson, Kara; Pok, Sochea; Palafox, Benjamin; Tougher, Sarah; O'Connell, Kate; Goodman, Catherine

    2013-09-05

    There is increased interest in using commercial providers for improving access to quality malaria treatment. Understanding their current role is an essential first step, notably in terms of the volume of diagnostics and anti-malarials they sell. Sales volume data can be used to measure the importance of different provider and product types, frequency of parasitological diagnosis and impact of interventions. Several methods for measuring sales volumes are available, yet all have methodological challenges and evidence is lacking on the comparability of different methods. Using sales volume data on anti-malarials and rapid diagnostic tests (RDTs) for malaria collected through provider recall (RC) and retail audits (RA), this study measures the degree of agreement between the two methods at wholesale and retail commercial providers in Cambodia following the Bland-Altman approach. Relative strengths and weaknesses of the methods were also investigated through qualitative research with fieldworkers. A total of 67 wholesalers and 107 retailers were sampled. Wholesale sales volumes were estimated through both methods for 62 anti-malarials and 23 RDTs and retail volumes for 113 anti-malarials and 33 RDTs. At wholesale outlets, RA estimates for anti-malarial sales were on average higher than RC estimates (mean difference of four adult equivalent treatment doses (95% CI 0.6-7.2)), equivalent to 30% of mean sales volumes. For RDTs at wholesalers, the between-method mean difference was not statistically significant (one test, 95% CI -6.0-4.0). At retail outlets, between-method differences for both anti-malarials and RDTs increased with larger volumes being measured, so mean differences were not a meaningful measure of agreement between the methods. Qualitative research revealed that in Cambodia where sales volumes are small, RC had key advantages: providers were perceived to remember more easily their sales volumes and find RC less invasive; fieldworkers found it more

  7. Comparing the frequency of hypertension determined by peri-dialysis measurement and ABPM in hemodialysis patients.

    Science.gov (United States)

    Abbasi, Mohammad-Reza; Lessan-Pezeshki, Mahboob; Najafi, Mohammad-Taghi; Gatmiri, Seyed-Mansour; Karbakhsh, Mojgan; Mohebi-Nejad, Azin

    2014-06-01

    Controlling blood pressure in hemodialysis patients is crucial but not always easy. The most common blood pressure measurement method is peri-dialysis measurement, but due to interdialytic blood pressure fluctuations, we are unsure if it is the proper way for evaluating blood pressure. Some studies have shown the superiority of 24-h ambulatory blood pressure monitoring over peri-dialysis blood pressure measurement. We aimed to compare the consistency of these methods in determining hypertension among hemodialysis patients. We studied 50 patients (mean age: 55.8 years) on regular hemodialysis in Imam Khomeini University Hospital, Tehran, Iran. Peri-dialysis blood pressure and interdialytic 24-h ambulatory blood pressure monitoring were recorded for each patient. Patients' demographic data and peri-dialysis weight were recorded too. All data were analyzed using the PASW Statistics 18.0, SPSS Inc. (Chicago, IL). There was a significant difference between pre-dialysis mean systolic blood pressure (146.1 ± 23.3 mmHg) and mean systolic blood pressure recorded by ambulatory blood pressure monitoring (135.3 ± 19.3 mmHg) (p = 0.001). There was also a significant difference between pre-dialysis mean diastolic blood pressure (83 ± 14 mmHg) and mean diastolic blood pressure recorded by ambulatory blood pressure monitoring (77.3 ± 10 mmHg) (p = 0.003). But the frequencies of hypertension measured with both methods were significantly consistent and the Kappa agreement coefficient was 0.525 (p = 0.001). Considering ambulatory blood pressure monitoring as the gold standard for blood pressure measurement, our recommendation for the best cutoff point to diagnose hypertension, with the highest sensitivity and specificity would be 135/80 mmHg for pre-dialysis blood pressure and 115/70 mmHg for post-dialysis blood pressure.

  8. Measuring health lifestyles in a comparative analysis: theoretical issues and empirical findings.

    Science.gov (United States)

    Abel, T

    1991-01-01

    The concept of lifestyle bears great potential for research in medical sociology. Yet, weaknesses in current methods have restrained lifestyle research from realizing its full potentials. The present focus is on the links between theoretical conceptions and their empirical application. The paper divides into two parts. The first part provides a discussion of basic theoretical and methodological issues. In particular selected lines of thought from Max Weber are presented and their usefulness in providing a theoretical frame of reference for health lifestyle research is outlined. Next, a theory guided definition of the subject matter is introduced and basic problems in empirical applications of theoretical lifestyle concepts are discussed. In its second part the paper presents findings from comparative lifestyle analyses. Data from the U.S. and West Germany are utilized to explore issues of measurement equivalence and theoretical validity. Factor analyses indicate high conceptual equivalence for new measures of health lifestyle dimensions in both the U.S. and West Germany. Divisive cluster analyses detect three distinct lifestyle groups in both nations. Implications for future lifestyle research are discussed.

  9. Measurement of hemoglobin A1 by liquid chromatography and by agar gel electrophoresis compared.

    Science.gov (United States)

    Hayes, E J; Gleason, R E; Soeldner, J S; Wacks, M; Blankstein, L

    1981-03-01

    We compare measurement of total fast hemoglobin (HbA1) by "high-performance" liquid chromatography and by electrophoresis on agar gel. Blood samples were obtained from a diverse population (n = 222): offspring of two diabetic parents, diabetic patients with and without retinopathy, diabetic and non-diabetic pregnant women, patients in the coronary-care unit, and normal persons. Precision studies with a normal and an above-normal A1 sample resulted in overall CVs of 9.0% and 4.6% for the electrophoretic method and 4.4% and 2% for the chromatographic method. Linear regression analysis of values for total fast hemoglobin for the complete sample population and for each subgroup showed results of the electrophoretic method to be in excellent agreement with those by the chromatographic method. We conclude that the agar gel electrophoretic method offers a reproducible means for HbA1 determination that is comparable to the HPLC method in terms of accuracy and is highly suited for routine laboratory use.

  10. Measuring satiety with pictures compared to visual analogue scales. An exploratory study.

    Science.gov (United States)

    Sadoul, Bastien C; Schuring, Ewoud A H; Symersky, Tomas; Mela, David J; Masclee, Ad A M; Peters, Harry P F

    2012-02-01

    Visual analogue scales (VAS) are a standard tool used to measure subjective appetite. To explore a potentially more intuitive and precise alternative, we developed a method based on pictures and assessed its performance characteristics vs. VAS. The objective was to compare the capacity of the two methods to discriminate appetite ratings between interventions. Both methods were applied within a previously published trial in which 16 healthy adults received standardised meals followed by three different ileal infusions in a balanced crossover design. At regular intervals volunteers indicated how many units of individually pictured food portions (for 10 different items) they would like to eat, and also scored six VAS. Methods were compared over different timeframes and assessed for their sensitivity to intervention effects. Pictures were more sensitive than VAS in differentiating intervention effects; however, further refinement and validation would be needed for pictures to become a standardised and accepted alternative to VAS for this type of research. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Measuring and Comparing Hospital Accessibility for Palm Beach County's Elderly and Nonelderly Populations During a Hurricane.

    Science.gov (United States)

    Prasad, Shivangi

    2017-09-18

    To determine whether, during a hurricane, geographic accessibility to hospitals with emergency care is compromised disproportionately for the elderly than for the nonelderly. The locations of hospitals with emergency health care and a subset of those hospitals functional during a hurricane were compared with the distribution of the elderly population at the block group level in Palm Beach County, Florida. Geographic Information Systems (GIS) proximity analysis (minimum distance to closest hospital) and cumulative distribution functions were used to measure and compare hospital accessibility during normal and hurricane conditions for the elderly and nonelderly populations. Accessibility to closest functional hospital during a hurricane was compromised disproportionately for the elderly. Geographic accessibility to emergency health care is compromised disproportionately for the elderly in Palm Beach County. Compounding the risk is the likelihood of the elderly experiencing a greater health care need during a hurricane. This poses a community public health crisis and calls for effective and collaborative planning between health professionals and disaster planners to address the health care needs of the elderly. (Disaster Med Public Health Preparedness. 2017;page 1 of 5).

  12. Comparative Study of Ground Measured, Satellite-Derived, and Estimated Global Solar Radiation Data in Nigeria

    Directory of Open Access Journals (Sweden)

    Boluwaji M. Olomiyesan

    2016-01-01

    Full Text Available In this study, the performance of three global solar radiation models and the accuracy of global solar radiation data derived from three sources were compared. Twenty-two years (1984–2005 of surface meteorological data consisting of monthly mean daily sunshine duration, minimum and maximum temperatures, and global solar radiation collected from the Nigerian Meteorological (NIMET Agency, Oshodi, Lagos, and the National Aeronautics Space Agency (NASA for three locations in North-Western region of Nigeria were used. A new model incorporating Garcia model into Angstrom-Prescott model was proposed for estimating global radiation in Nigeria. The performances of the models used were determined by using mean bias error (MBE, mean percentage error (MPE, root mean square error (RMSE, and coefficient of determination (R2. Based on the statistical error indices, the proposed model was found to have the best accuracy with the least RMSE values (0.376 for Sokoto, 0.463 for Kaduna, and 0.449 for Kano and highest coefficient of determination, R2 values of 0.922, 0.938, and 0.961 for Sokoto, Kano, and Kaduna, respectively. Also, the comparative study result indicates that the estimated global radiation from the proposed model has a better error range and fits the ground measured data better than the satellite-derived data.

  13. Comparing the T scores from bone sonometer measurements in Hispanic and non-Hispanic white women

    Directory of Open Access Journals (Sweden)

    Droege M

    2006-12-01

    Full Text Available Ethnicity is an important risk factor for the development of osteoporosis. Non-Hispanic white or Asian women are commonly considered at higher risk than other ethnicities. Hispanics in the U.S. are of Mexican, Caribbean, Central American, or South American descent. Conclusive data on the relative risk of osteoporosis in Hispanic women based upon heritage within the Hispanic population are not available. Objective: To investigate whether Hispanic white women are at a significantly lower risk than non-Hispanic whites for the development of osteoporosis. Methods: Cross-sectional study. Setting: Community health screenings. Participants: Hispanic and non-Hispanic white women. Intervention: Bone density measurements of the non-dominant heel. Descriptive statistics and inferential statistics including regression analyses were performed using SPSS 14.0. Main Outcomes Measure: T scores. Results: Overall, measurements were obtained from 352 women (209 Hispanic & 143 non-Hispanic white ranging in age from 55-97 years old. The mean T score obtained for Hispanic women was -1.194 and -1.280 for non-Hispanic white women. The correlation between the obtained T score and age was negative (r = -0.36, p<0.01, reflecting bone loss with increasing age. Regression analysis using age and ethnicity showed that ethnicity was a non-significant contributor to the best-fit regression line (t=0.60, p=0.55. Conclusion: This study indicates that Hispanic white women may be at comparable risk of developing osteoporosis as non-Hispanic white women.

  14. Comparing the Validity of Non-Invasive Methods in Measuring Thoracic Kyphosis and Lumbar Lordosis

    Directory of Open Access Journals (Sweden)

    Mohammad Yousefi

    2012-04-01

    Full Text Available Background: the purpose of this article is to study the validity of each of the non-invasive methods (flexible ruler, spinal mouse, and processing the image versus the one through-Ray radiation (the basic method and comparing them with each other.Materials and Methods: for evaluating the validity of each of these non-invasive methods, the thoracic Kyphosis and lumber Lordosis angle of 20 students of Birjand University (age mean and standard deviation: 26±2, weight: 72±2.5 kg, height: 169±5.5 cm through fours methods of flexible ruler, spinal mouse, and image processing and X-ray.Results: the results indicated that the validity of the methods including flexible ruler, spinal mouse, and image processing in measuring the thoracic Kyphosis and lumber Lordosis angle respectively have an adherence of 0.81, 0.87, 0.73, 0.76, 0.83, 0.89 (p>0.05. As a result, regarding the gained validity against the golden method of X-ray, it could be stated that the three mentioned non-invasive methods have adequate validity. In addition, the one-way analysis of variance test indicated that there existed a meaningful relationship between the three methods of measuring the thoracic Kyphosis and lumber Lordosis, and with respect to the Tukey’s test result, the image processing method is the most precise one.Conclusion as a result, this method could be used along with other non-invasive methods as a valid measuring method.

  15. Measuring learning gain: Comparing anatomy drawing screencasts and paper-based resources.

    Science.gov (United States)

    Pickering, James D

    2017-07-01

    The use of technology-enhanced learning (TEL) resources is now a common tool across a variety of healthcare programs. Despite this popular approach to curriculum delivery there remains a paucity in empirical evidence that quantifies the change in learning gain. The aim of the study was to measure the changes in learning gain observed with anatomy drawing screencasts in comparison to a traditional paper-based resource. Learning gain is a widely used term to describe the tangible changes in learning outcomes that have been achieved after a specific intervention. In regard to this study, a cohort of Year 2 medical students voluntarily participated and were randomly assigned to either a screencast or textbook group to compare changes in learning gain across resource type. Using a pre-test/post-test protocol, and a range of statistical analyses, the learning gain was calculated at three test points: immediate post-test, 1-week post-test and 4-week post-test. Results at all test points revealed a significant increase in learning gain and large effect sizes for the screencast group compared to the textbook group. Possible reasons behind the difference in learning gain are explored by comparing the instructional design of both resources. Strengths and weaknesses of the study design are also considered. This work adds to the growing area of research that supports the effective design of TEL resources which are complimentary to the cognitive theory of multimedia learning to achieve both an effective and efficient learning resource for anatomical education. Anat Sci Educ 10: 307-316. © 2016 American Association of Anatomists. © 2016 American Association of Anatomists.

  16. Comparative ultrasound measurement of normal thyroid gland dimensions in school aged children in our local environment.

    Science.gov (United States)

    Marchie, T T; Oyobere, O; Eze, K C

    2012-01-01

    The objective of this study was to determine the measurement of normal range of ultrasound (US) thyroid gland dimensions in school-aged children (6-16 years) in our environment and compared with what is obtained elsewhere. A prospective ultrasound measurement study done in University of Benin Teaching Hospital Benin, Nigeria. A prospective ultrasound (US) study of thyroid dimensions of 500 school-aged children in our environment consisting of 227 boys and 273 girls was done from 1 December 2006 to July 2007. The subjects were examined by the authors and subjects with palpable abnormal thyroid gland were excluded from the study. The thyroid dimensions (length, height, and diameter) were taken for each lobe by means of ultrasound (US). In addition volume of each thyroid lobe was calculated and the summation of volume of the lobes was taken as thyroid gland volume of each subject. Also height and weight of patients were documented from which the subject's body surface was calculated. Incidental thyroid gland lesion in US was excluded from the study. Using the Statistical program of social science (SPSS) and INSTAT (Graph Pad Inc. USA) the data were analyzed. Informed consent was obtained from all the subjects and the study was done in line with the ethical guidelines of the centers. The US thyroid gland volume in school-aged children in Benin City from this study ranges between 1.17 cm 3 and 7.19 cm 3 , mean volume range of 1.76-4.95 cm 3 , median volume range of 1.73-4.73 cm 3 , and range of standard deviation from 0.39 cm 3 to 1.49 cm 3 . The average mean thyroid volume is 2.32 cm 3 with the following average dimensions; anteroposterior right lobe =1.06 cm, mediolateral right lobe = 1.01 cm and craniocaudal right lobe = 2.34 cm, and anteroposterior left lobe = 1.01 cm, mediolateral left lobe = 1.04 cm and craniocaudal left lobe = 2.41 cm for both boys and girls respectively. These data are significantly lower than data obtained by European based World Health

  17. Comparative performance of Bayesian and AIC-based measures of phylogenetic model uncertainty.

    Science.gov (United States)

    Alfaro, Michael E; Huelsenbeck, John P

    2006-02-01

    Reversible-jump Markov chain Monte Carlo (RJ-MCMC) is a technique for simultaneously evaluating multiple related (but not necessarily nested) statistical models that has recently been applied to the problem of phylogenetic model selection. Here we use a simulation approach to assess the performance of this method and compare it to Akaike weights, a measure of model uncertainty that is based on the Akaike information criterion. Under conditions where the assumptions of the candidate models matched the generating conditions, both Bayesian and AIC-based methods perform well. The 95% credible interval contained the generating model close to 95% of the time. However, the size of the credible interval differed with the Bayesian credible set containing approximately 25% to 50% fewer models than an AIC-based credible interval. The posterior probability was a better indicator of the correct model than the Akaike weight when all assumptions were met but both measures performed similarly when some model assumptions were violated. Models in the Bayesian posterior distribution were also more similar to the generating model in their number of parameters and were less biased in their complexity. In contrast, Akaike-weighted models were more distant from the generating model and biased towards slightly greater complexity. The AIC-based credible interval appeared to be more robust to the violation of the rate homogeneity assumption. Both AIC and Bayesian approaches suggest that substantial uncertainty can accompany the choice of model for phylogenetic analyses, suggesting that alternative candidate models should be examined in analysis of phylogenetic data. [AIC; Akaike weights; Bayesian phylogenetics; model averaging; model selection; model uncertainty; posterior probability; reversible jump.].

  18. Electric field measurements on Cluster: comparing the double-probe and electron drift techniques

    Directory of Open Access Journals (Sweden)

    A. I. Eriksson

    2006-03-01

    Full Text Available The four Cluster satellites each carry two instruments designed for measuring the electric field: a double-probe instrument (EFW and an electron drift instrument (EDI. We compare data from the two instruments in a representative sample of plasma regions. The complementary merits and weaknesses of the two techniques are illustrated. EDI operations are confined to regions of magnetic fields above 30 nT and where wave activity and keV electron fluxes are not too high, while EFW can provide data everywhere, and can go far higher in sampling frequency than EDI. On the other hand, the EDI technique is immune to variations in the low energy plasma, while EFW sometimes detects significant nongeophysical electric fields, particularly in regions with drifting plasma, with ion energy (in eV below the spacecraft potential (in volts. We show that the polar cap is a particularly intricate region for the double-probe technique, where large nongeophysical fields regularly contaminate EFW measurments of the DC electric field. We present a model explaining this in terms of enhanced cold plasma wake effects appearing when the ion flow energy is higher than the thermal energy but below the spacecraft potential multiplied by the ion charge. We suggest that these conditions, which are typical of the polar wind and occur sporadically in other regions containing a significant low energy ion population, cause a large cold plasma wake behind the spacecraft, resulting in spurious electric fields in EFW data. This interpretation is supported by an analysis of the direction of the spurious electric field, and by showing that use of active potential control alleviates the situation.

  19. Comparing subjective image quality measurement methods for the creation of public databases

    Science.gov (United States)

    Redi, Judith; Liu, Hantao; Alers, Hani; Zunino, Rodolfo; Heynderickx, Ingrid

    2010-01-01

    The Single Stimulus (SS) method is often chosen to collect subjective data testing no-reference objective metrics, as it is straightforward to implement and well standardized. At the same time, it exhibits some drawbacks; spread between different assessors is relatively large, and the measured ratings depend on the quality range spanned by the test samples, hence the results from different experiments cannot easily be merged . The Quality Ruler (QR) method has been proposed to overcome these inconveniences. This paper compares the performance of the SS and QR method for pictures impaired by Gaussian blur. The research goal is, on one hand, to analyze the advantages and disadvantages of both methods for quality assessment and, on the other, to make quality data of blur impaired images publicly available. The obtained results show that the confidence intervals of the QR scores are narrower than those of the SS scores. This indicates that the QR method enhances consistency across assessors. Moreover, QR scores exhibit a higher linear correlation with the distortion applied. In summary, for the purpose of building datasets of subjective quality, the QR approach seems promising from the viewpoint of both consistency and repeatability.

  20. Thermal and fluid simulation of the environment under the dashboard, compared with measurement data

    Science.gov (United States)

    Popescu, C. S.; Sirbu, G. M.; Nita, I. C.

    2017-10-01

    The development of vehicles during the last decade is related to the evolution of electronic systems added in order to increase the safety and the number of services available on board, such as advanced driver-assistance systems (ADAS). Cars already have a complex computer network, with electronic control units (ECUs) connected to each other and receiving information from many sensors. The ECUs transfer an important heat power to the environment, while proper operating conditions need to be provided to ensure their reliability at high and low temperature, vibration and humidity. In a car cabin, electronic devices are usually placed in the compartment under the dashboard, an enclosed space designed for functional purposes. In the early stages of the vehicle design it has become necessary to analyse the environment under dashboard, by the use of Computational Fluid Dynamics (CFD) simulations and measurements. This paper presents the cooling of heat sinks by natural convection, a thermal and fluid simulation of the environment under the dashboard compared with test data.

  1. Bioindicators in the MIDUS National Study: Protocol, Measures, Sample, and Comparative Context

    Science.gov (United States)

    Love, Gayle Dienberg; Seeman, Teresa E.; Weinstein, Maxine; Ryff, Carol D.

    2010-01-01

    Objectives MIDUS is a national study of health and aging among individuals aged 25 to 74 at baseline(1995/96). Longitudinal survey assessments (2004/05), were followed by biological assessments on a subsample aged 35–85. To facilitate public use, we describe the protocol, measures, and sample. Methods Respondents traveled to clinics for a two-day data collection protocol that included fasting blood specimens, 12-hour urine specimen, medical history, physical exam, bone densitometry, a laboratory challenge (heart rate variability, blood pressure, respiration, salivary cortisol). Results Response rates for the biological protocol (N = 1,255) were 39.3%, or 43.1% (adjusting for those who could not be located or contacted). Reasons for non-participation were travel, family obligations, and being too busy. Respondents were comparable to the recruitment pool on most demographic characteristics and health assessments. Discussion Strengths of the protocol vis-à-vis other similar studies include opportunities to link biological factors with diverse content from other MIDUS projects. PMID:20876364

  2. Measuring Medical Housestaff Teamwork Performance Using Multiple Direct Observation Instruments: Comparing Apples and Apples.

    Science.gov (United States)

    Weingart, Saul N; Yaghi, Omar; Wetherell, Matthew; Sweeney, Megan

    2018-04-10

    To examine the composition and concordance of existing instruments used to assess medical teams' performance. A trained observer joined 20 internal medicine housestaff teams for morning work rounds at Tufts Medical Center, a 415-bed Boston teaching hospital, from October through December 2015. The observer rated each team's performance using 9 teamwork observation instruments that examined domains including team structure, leadership, situation monitoring, mutual support, and communication. Observations recorded on paper forms were stored electronically. Scores were normalized from 1 (low) to 5 (high) to account for different rating scales. Overall mean scores were calculated and graphed; weighted scores adjusted for the number of items in each teamwork domain. Teamwork scores were analyzed using t-tests, pair-wise correlations, and the Kruskal-Wallis statistic, and team performance was compared across instruments by domain. The 9 tools incorporated 5 major domains, with 5-35 items per instrument for a total of 161 items per observation session. In weighted and unweighted analyses, the overall teamwork performance score for a given team on a given day varied by instrument. While all of the tools identified the same low outlier, high performers on some instruments were low performers on others. Inconsistent scores for a given team across instruments persisted in domain-level analyses. There was substantial variation in the rating of individual teams assessed concurrently by a single observer using multiple instruments. Since existing teamwork observation tools do not yield concordant assessments, researchers should create better tools for measuring teamwork performance.

  3. A comparative study of computed radiographic cephalometry and conventional cephalometry in reliability of head film measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung Done; Kim, Kee Deog; Park, Chang Seo [Dept. of Dental Radiology, College of Dentistry, Yensei University, Seoul(Korea, Republic of)

    1997-02-15

    The purpose of this study was to compare and to find out the variability of head film measurements (landmarks identification) between Fuji computed radiographic cephalometry and conventional cephalometry. 28 Korean adults were selected. Lateral cephalometric FCR film and conventional cephalometric film of each subject was taken. Four investigators identified 24 cephalometric landmarks on lateral cephalometric FCR film and conventional cephalometric film were statistically analysed. The results were as follows : 1. In FCR film and conventional film, coefficient of variation (C.V.) of 24 landmarks was taken horizontally and vertically. 2. In comparison of significant differences of landmarks variability between FCR film and conventional film, horizontal l value of coefficient of variation showed significant differences in four landmarks among twenty-four landmarks, but vertical a value of coefficient of variation showed significant differences in sixteen landmarks among twenty-four landmarks. FCR film showed significantly less variability than conventional film in 17 subjects among 20 (4+16) subjects that sho wed significant difference.

  4. Comparing Global Positioning System (GPS) and Global Navigation Satellite System (GNSS) Measures of Team Sport Movements.

    Science.gov (United States)

    Jackson, Benjamin M; Polglaze, Ted; Dawson, Brian; King, Trish; Peeling, Peter

    2018-02-21

    To compare data from conventional GPS and new GNSS-enabled tracking devices, and to examine the inter-unit reliability of GNSS devices. Inter-device differences between 10 Hz GPS and GNSS devices were examined during laps (n=40) of a simulated game circuit (SGC) and during elite hockey matches (n=21); GNSS inter-unit reliability was also examined during the SGC laps. Differences in distance values and measures in three velocity categories (low 5 m.s -1 ) and acceleration/deceleration counts (>1.46 m.s -2 and GNSS reliability was examined using the coefficient of variation (CV) and intra-class correlation coefficient (ICC). Inter-device differences (P GNSS) differences (P GNSS devices had a lower HDoP score than GPS devices in all conditions. These findings suggest that GNSS devices may be more sensitive than GPS in quantifying the physical demands of team sport movements, but further study into the accuracy of GNSS devices is required.

  5. A comparative study of computed radiographic cephalometry and conventional cephalometry in reliability of head film measurements

    International Nuclear Information System (INIS)

    Kim, Hyung Done; Kim, Kee Deog; Park, Chang Seo

    1997-01-01

    The purpose of this study was to compare and to find out the variability of head film measurements (landmarks identification) between Fuji computed radiographic cephalometry and conventional cephalometry. 28 Korean adults were selected. Lateral cephalometric FCR film and conventional cephalometric film of each subject was taken. Four investigators identified 24 cephalometric landmarks on lateral cephalometric FCR film and conventional cephalometric film were statistically analysed. The results were as follows : 1. In FCR film and conventional film, coefficient of variation (C.V.) of 24 landmarks was taken horizontally and vertically. 2. In comparison of significant differences of landmarks variability between FCR film and conventional film, horizontal l value of coefficient of variation showed significant differences in four landmarks among twenty-four landmarks, but vertical a value of coefficient of variation showed significant differences in sixteen landmarks among twenty-four landmarks. FCR film showed significantly less variability than conventional film in 17 subjects among 20 (4+16) subjects that sho wed significant difference.

  6. Delayed hadrons in air showers observed in Chacaltaya

    International Nuclear Information System (INIS)

    Kakimoto, Fumio

    1984-01-01

    Bolivian Air Shower Joint Experiment group has studied high energy interaction by measuring the aspect of vertical growth of air showers of 10 16 eV or more at Mt. Chacaltaya Space Physics Observatory at 5200 m above sea level and atmospheric depth of 550 g/cm 2 . The aspect of vertical growth of electrons from about 100 g/cm 2 to about 400 g/cm 2 of atmospheric depth obtained by the measured results of the time of arrival distribution of air Cherenkov radiation at Mt. Chacaltaya agreed with the one predicted from the enhanced 1/2 power of E model. Since the vertical growth of electrons and muons in about 10 17 eV air showers from the atmospheric apex was difficult to give the unified explanation with known interaction models, the University of Tokyo group has proposed a two-component model for air shower growth. If this second component is formed from heavy particles or heavy quantum state as parents, it should be observed as the component which arrives later in air shower. Thus, the measurement and experiment on the delayed hadrons in air showers have been started. In this paper, the experiment, analysis and results are reported. It is clear that the parent particles which caused such a phenomenon were not pions which were multiply generated by the interaction generally known. Therefore, an exact simulating calculation must be performed and compared with the experimental results to obtain the final conclusion from the measured results of this time. (Wakatsuki, Y.)

  7. Water vapor measurements at ALOMAR over a solar cycle compared with model calculations by LIMA

    Science.gov (United States)

    Hartogh, P.; Sonnemann, G. R.; Grygalashvyly, M.; Song, Li; Berger, U.; Lübken, F.-J.

    2010-01-01

    influenced the long-term variability. We show results of measurements, compare these with calculations, and discuss the chemical and dynamical backgrounds of the variation of water vapor in the middle atmosphere.

  8. In-air and underwater hearing of the cormorant

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Wahlberg, Magnus; Christensen-Dalsgaard, Jakob

    Numerous studies have mapped the hearing abilities of birds in air but currently there is little or no data on how diving birds hear or react to sound under water. Therefore, it is unknown whether the ears and auditory system of diving birds are adapted to underwater hearing. In the present study...... 10 cm under water in a large water filled-tank while being artificially ventilated. ABR-responses to calibrated tone bursts produced by a woofer and an underwater speaker, respectively, were measured at different intensities and frequencies to obtain hearing threshold values in air and under water......Hz) under water. Generally, the cormorant ear was not very sensitive to sound, neither in air nor under water. The hearing abilities in water, however, were better than what would have been expected for a purely in-air adapted ear. (Supported by the Carlsberg Foundation 2009_01_0292 and the Danish Council...

  9. Comparing hypothetical versus non-hypothetical methods for measuring willingness to pay in a food context

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Carrasco, L.; Brugarolas, M.; Martínez-Poveda, A.; Ruiz-Martínez, J.J.

    2015-07-01

    Choosing a valid procedure to measure willingness to pay (WTP) is crucial for designating optimum price policies or for evaluating the demand for new products. This study compares two methods for obtaining WTP in a food context: a random nth price auction and an open-ended contingent valuation (CV) question. Participants were regular salad tomato buyers of Alicante and they were randomly assigned to one of the two treatments. The products about which they would show their WTP were traditional tomato varieties. Both treatments were divided into three stages: in the first stage the only available information was a reference price for the tomatoes. In stages 2 and 3 we revealed the local origin and the organic grown of the tomatoes respectively. Our results show that in the auction the percentage of participants willing to pay the same or more than the reference price was between 20 and 30%. In the CV method this percentage was between 40 and 65%. The mean WTP in the auction, considering the whole of the individuals, was situated between 1.90 and 2.13 €/kg. These same results obtained through the CV were situated between 2.54 and 3.21 €/kg. The results confirmed the findings of previous papers in which the hypothetical bias of CV was clarified because it yields higher values for WTP than the auction, especially when referring to the number of individuals willing to pay more. Additionally, hedonic price models were estimated for the prices obtained by both methods with the result that in all the models, WTP was directly related to the price paid for the latest purchase of tomatoes. (Author)

  10. Comparative analysis of measures of viral reservoirs in HIV-1 eradication studies.

    Directory of Open Access Journals (Sweden)

    Susanne Eriksson

    2013-02-01

    Full Text Available HIV-1 reservoirs preclude virus eradication in patients receiving highly active antiretroviral therapy (HAART. The best characterized reservoir is a small, difficult-to-quantify pool of resting memory CD4(+ T cells carrying latent but replication-competent viral genomes. Because strategies targeting this latent reservoir are now being tested in clinical trials, well-validated high-throughput assays that quantify this reservoir are urgently needed. Here we compare eleven different approaches for quantitating persistent HIV-1 in 30 patients on HAART, using the original viral outgrowth assay for resting CD4(+ T cells carrying inducible, replication-competent viral genomes as a standard for comparison. PCR-based assays for cells containing HIV-1 DNA gave infected cell frequencies at least 2 logs higher than the viral outgrowth assay, even in subjects who started HAART during acute/early infection. This difference may reflect defective viral genomes. The ratio of infected cell frequencies determined by viral outgrowth and PCR-based assays varied dramatically between patients. Although strong correlations with the viral outgrowth assay could not be formally excluded for most assays, correlations achieved statistical significance only for integrated HIV-1 DNA in peripheral blood mononuclear cells and HIV-1 RNA/DNA ratio in rectal CD4(+ T cells. Residual viremia was below the limit of detection in many subjects and did not correlate with the viral outgrowth assays. The dramatic differences in infected cell frequencies and the lack of a precise correlation between culture and PCR-based assays raise the possibility that the successful clearance of latently infected cells may be masked by a larger and variable pool of cells with defective proviruses. These defective proviruses are detected by PCR but may not be affected by reactivation strategies and may not require eradication to accomplish an effective cure. A molecular understanding of the discrepancy

  11. International Comparability of 131I, 201TI and 99mTc Activity Measurements performed in Cuban Nuclear Medicine

    International Nuclear Information System (INIS)

    Oropesa, P; Serra, R; Hernandez, A.T.; Varela, C

    2006-01-01

    This paper refers about the International Comparability of 131 I, 201 TI and 99m Tc Activity Measurements performed in Cuban Nuclear Medicine. Traceability of activity measurements in nuclear medicine based in two aspects: Comparability of clinic results and the safe and effective use of drugs. A bilateral international comparison for activity measurements CIEMAT CENTIS DMR was done. 2000-2004 National Program for 99m Tc 201 TI, 131 I vial and syringe measurements in radionuclide calibrators including a simulated test for activity administration. It is employed the Cause Effect Diagram for the activity measurement result of a source in the calibrator and the statistical methods for comparing several characteristics of the obtained data. The result of the comparisons demonstrates that the measurement quality has increased from one year to another

  12. Comparative study of the gamma spectrometry method performance in different measurement geometries

    International Nuclear Information System (INIS)

    Diaconescu, C.; Ichim, C.; Bujoreanu, L.; Florea, I.

    2013-01-01

    This paper presents the results obtained by gamma spectrometry on aqueous liquid waste sample using different measurement geometries. A liquid waste sample with known gamma emitters content was measured in three different geometries in order to assess the influence of the geometry on the final results. To obtain low measurement errors, gamma spectrometer was calibrated using a calibration standard with the same physical and chemical characteristics as the sample to be measured. Since the calibration was performed with the source at contact with HPGe detector, the waste sample was also measured, for all the three geometries, at the detector contact. The influence of the measurement geometry on the results was evaluated by computing the relative errors. The measurements performed using three different geometries (250 ml plastic vial, Sarpagan box and 24 ml Tricarb vial) showed that all these geometries may be used to quantify the activity of gamma emitters in different type of radioactive waste. (authors)

  13. Laser Noise Reduction in Air

    OpenAIRE

    Bejot, Pierre; Kasparian, Jerome; Salmon, Estelle; Ackermann, Roland; Gisin, Nicolas; Wolf, Jean-Pierre

    2006-01-01

    Fluctuations of the white-light supercontinuum produced by ultrashort laser pulses in selfguided filaments (spatio-temporal solitons) in air are investigated. We demonstrate that correlations exist within the white-light supercontinuum, and that they can be used to significantly reduce the laser intensity noise by filtering the spectrum. More precisely, the fundamental wavelength is anticorrelated with the wings of the continuum, while conjugated wavelength pairs on both sides of the continuu...

  14. Comparative study of cranial anthropometric measurement by traditional calipers to computed tomography and three-dimensional photogrammetry.

    Science.gov (United States)

    Mendonca, Derick A; Naidoo, Sybill D; Skolnick, Gary; Skladman, Rachel; Woo, Albert S

    2013-07-01

    Craniofacial anthropometry by direct caliper measurements is a common method of quantifying the morphology of the cranial vault. New digital imaging modalities including computed tomography and three-dimensional photogrammetry are similarly being used to obtain craniofacial surface measurements. This study sought to compare the accuracy of anthropometric measurements obtained by calipers versus 2 methods of digital imaging.Standard anterior-posterior, biparietal, and cranial index measurements were directly obtained on 19 participants with an age range of 1 to 20 months. Computed tomographic scans and three-dimensional photographs were both obtained on each child within 2 weeks of the clinical examination. Two analysts measured the anterior-posterior and biparietal distances on the digital images. Measures of reliability and bias between the modalities were calculated and compared.Caliper measurements were found to underestimate the anterior-posterior and biparietal distances as compared with those of the computed tomography and the three-dimensional photogrammetry (P photogrammetry (P = 0.002). The coefficients of variation for repeated measures based on the computed tomography and the three-dimensional photogrammetry were 0.008 and 0.007, respectively.In conclusion, measurements based on digital modalities are generally reliable and interchangeable. Caliper measurements lead to underestimation of anterior-posterior and biparietal values compared with digital imaging.

  15. Using Two Disability Measures to Compare Physical Inactivity Among US Adults With Disabilities.

    Science.gov (United States)

    McGuire, Dana Olzenak; Watson, Kathleen B; Carroll, Dianna D; Courtney-Long, Elizabeth A; Carlson, Susan A

    2018-01-18

    Prevalence of health behaviors among adults with disabilities may vary by disability measure. We used data from the 2011-2015 National Health Interview Survey to estimate prevalence of physical inactivity by disability status using 2 measures of disability: Basic Actions Difficulty questions (BADQ) and a standard 6-question measure (6Q). Disability prevalence (BADQ, 31.1%; 6Q, 17.5%) and inactivity prevalence among adults with disability (BADQ, 42.9%; 6Q, 52.5%) and without disability (BADQ, 24.3%; 6Q, 26.2%) varied by measure; however, both measures highlight inactivity disparities for adults with disability. Disability measures influence physical inactivity estimates and are important for guiding surveillance and health promotion activities for adults with disabilities.

  16. Comparative efficacy of a self-report scale and physiological measures in dental anxiety of children.

    Science.gov (United States)

    Manepalli, Swapna; Nuvvula, Sivakumar; Kamatham, Rekhalakshmi; Nirmala, Sunkara

    2014-11-01

    To determine and correlate dental anxiety in children, using psychometric and physiological measures. On hundred children (51 boys and 49 girls) were selected and anxiety was assessed using psychometric (Modified Child Dental Anxiety Scale) and physiological measures (pulse rate and oxygen saturation levels), for local anesthetic administration. Statistical analysis was carried out with SPSS software version 11.0. Metric continuous data are presented as mean ± standard deviation. Analysis between groups was carried out by using one way anova. Categorical variables were analyzed with "Fisher's exact test". For statistical significance, the probability value of anxiety. Both psychometric and physiological measures have their own merits and are important clinically. Even behavioral measures, although having observer bias, can be used as an adjuvant along with these measures. It is essential to take two or more measures into consideration rather than just one to assess dental anxiety. © 2013 Wiley Publishing Asia Pty Ltd.

  17. Programmes of measures under the water framework directive – a comparative case study

    DEFF Research Database (Denmark)

    Baaner, Lasse

    2011-01-01

    The water framework directive requires programmes of measures composed by the Member States, in order to achieve its environmental objectives. This article examines three programmes of measures for river basins in Denmark, Sweden, and Norway, with a focus on the differences in how the programmes...

  18. Accuracy of tidal breathing measurement of FloRight compared to an ultrasonic flowmeter in infants

    NARCIS (Netherlands)

    Petrus, Nicole C. M.; Thamrin, Cindy; Fuchs, Oliver; Frey, Urs

    2015-01-01

    Monitoring breathing pattern is especially relevant in infants with lung disease. Recently, a vest-based inductive plethysmograph system (FloRight®) has been developed for tidal breathing measurement in infants. We investigated the accuracy of tidal breathing flow volume loop (TBFVL) measurements in

  19. Comparing Graphical and Verbal Representations of Measurement Error in Test Score Reports

    Science.gov (United States)

    Zwick, Rebecca; Zapata-Rivera, Diego; Hegarty, Mary

    2014-01-01

    Research has shown that many educators do not understand the terminology or displays used in test score reports and that measurement error is a particularly challenging concept. We investigated graphical and verbal methods of representing measurement error associated with individual student scores. We created four alternative score reports, each…

  20. Conquest from Within: A Comparative Analysis between Soviet Active Measures and United States Unconventional Warfare Doctrine

    Science.gov (United States)

    2015-05-27

    Soviet active measures include: Manipulation or control of the media . Written or oral disinformation . Use of foreign Communist parties and front...course of world events”: Active measures ranged ‘from media manipulations to special actions involving various degrees of violence’ and included... disinformation , particularly forgeries. - manipulation of foreign media through controlled assets and press placements. - agents of influence

  1. Comparing methods for measuring consumer willingness to pay: A cognitive perspective

    DEFF Research Database (Denmark)

    Grunert, Klaus G.; Madsen, Charlotte Øland; Juhl, Hans Jørn

    Willingness to pay for a basic chilled soup product and for an improved, self-heating version was measured for 100 Ss who were randomly assigned to conditions: a contingent valuation scheme, and an experimental auction scheme. Drawing on constructs derived from research in consumer price informat......Willingness to pay for a basic chilled soup product and for an improved, self-heating version was measured for 100 Ss who were randomly assigned to conditions: a contingent valuation scheme, and an experimental auction scheme. Drawing on constructs derived from research in consumer price...... information processing, Ss reference price, price involvement, and WTP thought style were also measured. Results showed significant main effects for WTP measurement method and for Ss price information characteristics on measured willingness to pay for the main product, and a method x thought style interaction...

  2. BETWEEN PARCIMONY AND COMPLEXITY: COMPARING PERFORMANCE MEASURES FOR ROMANIAN BANKING INSTITUTIONS

    Directory of Open Access Journals (Sweden)

    ANCA MUNTEANU

    2012-01-01

    Full Text Available The main objective of this study is to establish the relationship between traditional measures of performance (ROE, ROA and NIM and EVA in order to gain some insight about the relevance of using more sophisticated performance measurements tools. Towards this end the study uses two acknowledged statistical measures: Kendall’s Tau and Spearman rank correlation Index. Using data from 12 Romanian banking institutions that report under IFRS for the period 2006-2010 the results suggest that generally EVA is highly correlated with Residual Income in the years that present positive operational profits whereas for the years with negative outcome the correlation is low. ROA and ROE are the measure that best correlates with EVA for the entire period and thus -applying Occam’s razor- could be used as a substitute for more complex shareholder earnings measures.

  3. Measuring Link-Resolver Success: Comparing 360 Link with a Local Implementation of WebBridge

    Science.gov (United States)

    Herrera, Gail

    2011-01-01

    This study reviewed link resolver success comparing 360 Link and a local implementation of WebBridge. Two methods were used: (1) comparing article-level access and (2) examining technical issues for 384 randomly sampled OpenURLs. Google Analytics was used to collect user-generated OpenURLs. For both methods, 360 Link out-performed the local…

  4. Criteria for a comparative assessment on handheld gamma-ray measurement tools

    International Nuclear Information System (INIS)

    Feichtinger, J.; Schwaiger, M.; Schmitzer, C.; Kindl, P.

    2001-01-01

    Full text: The radionuclide laboratories at the Austrian Research Centres Seibersdorf are strongly involved in radiation protection of public and employees as well as in environmental monitoring with special concern to gamma spectrometric measurements. Hence, field measurements and therefore the subject of hand-held measurement devices is a topic of main interest. Taking into consideration, that these hand-held measurement tool are further used in critical and sensitive operations, as for example by the IAEA Safeguards or by CTBTO On-Site inspectors, a standard for characterising these gamma measurement tools seems to be sound as necessary. The poster presents a set of technical criteria as well as limiting values, which allows an objective comparison of hand-held measurement devices. The criteria can be divided into three individual parts: radiometric characteristics, ergonomics and usability in field operations. The main criteria for testing the radiometry performance of hand-held measurement devices are sensitivity, efficiency, energy response, energy resolution and nuclide identification or not identification (if necessary), detection probability, dose rate indication, uncertainty, etc. The ergonomic test contains as dominating parts handling and quality of the manual. To evaluate the applicability in field operations different environmental conditions (e.g. light conditions, temperature range, moisture...) as well as battery lifetime and weight should be taken into account. These criteria may vary in dependence of the requirements or limitations given by various external conditions, but still a standard to evaluate and will give the opportunity to provide an objective comparison. (author)

  5. Multidetector-Row Computed Tomography Allows Accurate Measurement of Mechanical Prosthetic Heart Valve Leaflet Closing Angles Compared With Fluoroscopy

    NARCIS (Netherlands)

    Suchá, Dominika; Symersky, Petr; Vonken, Evert-Jan P. A.; Provoost, Esther; Chamuleau, Steven A. J.; Budde, Ricardo P. J.

    2014-01-01

    Purpose: The purpose of this study was to compare multidetector-row computed tomography (MDCT) leaflet restriction measurements with fluoroscopy measurements in commonly used mechanical prosthetic heart valves (PHVs). Methods: Four mechanical PHVs (ON-X, Carbomedics, St. Jude, and Medtronic Hall)

  6. Comparing the influence of various measurement error presentations in test score reports on educational decision-making

    NARCIS (Netherlands)

    Hopster-den Otter, Dorien; Muilenburg, Selia N.; Wools, Saskia; Veldkamp, Bernard P.; Eggen, Theo T.J.H.M.

    2018-01-01

    This study investigated (1) the extent to which presentations of measurement error in score reports influence teachers’ decisions and (2) teachers’ preferences in relation to these presentations. Three presentation formats of measurement error (blur, colour value and error bar) were compared to a

  7. Performance of the RAD-57 pulse CO-oximeter compared with standard laboratory carboxyhemoglobin measurement.

    Science.gov (United States)

    Touger, Michael; Birnbaum, Adrienne; Wang, Jessica; Chou, Katherine; Pearson, Darion; Bijur, Polly

    2010-10-01

    We assess agreement between carboxyhemoglobin levels measured by the Rad-57 signal extraction pulse CO-oximeter (RAD), a Food and Drug Administration-approved device for noninvasive bedside measurement, and standard laboratory arterial or venous measurement in a sample of emergency department (ED) patients with suspected carbon monoxide poisoning. The study was a cross-sectional cohort design using a convenience sample of adult and pediatric ED patients in a Level I trauma, burn, and hyperbaric oxygen referral center. Measurement of RAD carboxyhemoglobin was performed simultaneously with blood sampling for laboratory determination of carboxyhemoglobin level. The difference between the measures for each patient was calculated as laboratory carboxyhemoglobin minus carboxyhemoglobin from the carbon monoxide oximeter. The limits of agreement from a Bland-Altman analysis are calculated as the mean of the differences between methods ±1.96 SDs above and below the mean. Median laboratory percentage carboxyhemoglobin level was 2.3% (interquartile range 1 to 8.5; range 0% to 38%). The mean difference between laboratory carboxyhemoglobin values and RAD values was 1.4% carboxyhemoglobin (95% confidence interval [CI] 0.2% to 2.6%). The limits of agreement of differences of measurement made with the 2 devices were -11.6% and 14.4% carboxyhemoglobin. This range exceeded the value of ±5% carboxyhemoglobin defined a priori as clinically acceptable. RAD correctly identified 11 of 23 patients with laboratory values greater than 15% carboxyhemoglobin (sensitivity 48%; 95% CI 27% to 69%). There was one case of a laboratory carboxyhemoglobin level less than 15%, in which the RAD device gave a result greater than 15% (specificity of RAD 96/97=99%; 95% CI 94% to 100%). In the range of carboxyhemoglobin values measured in this sample, the level of agreement observed suggests RAD measurement may not be used interchangeably with standard laboratory measurement. Copyright © 2010 American

  8. Small field in-air output factors: the role of miniphantom design and dosimeter type.

    Science.gov (United States)

    Warrener, Kirbie; Hug, Benjamin; Liu, Paul; Ralston, Anna; Ebert, Martin A; McKenzie, David R; Suchowerska, Natalka

    2014-02-01

    The commissioning of treatment planning systems and beam modeling requires measured input parameters. The measurement of relative output in-air, Sc is particularly difficult for small fields. The purpose of this study was to investigate the influence of miniphantom design and detector selection on measured Sc values for small fields and to validate the measurements against Monte Carlo simulations. Measurements were performed using brass caps (with sidewalls) or tops (no sidewalls) of varying heights and widths. The performance of two unshielded diodes (60012 and SFD), EBT2 radiochromic film, and a fiber optic dosimeter (FOD) were compared for fields defined by MLCs (5-100 mm) and SRS cones (4-30 mm) on a Varian Novalis linear accelerator. Monte Carlo simulations were performed to theoretically predict Sc as measured by the FOD. For all detectors, Sc agreed to within 1% for fields larger than 10 mm and to within 2.3% for smaller fields. Monte Carlo simulation matched the FOD measurements for all size of cone defined fields to within 0.5%. Miniphantom design is the most important variable for reproducible and accurate measurements of the in-air output ratio, S(c), in small photon fields (less than 30 mm). Sidewalls are not required for fields ≤ 30 mm and tops are therefore preferred over the larger caps. Unlike output measurements in water, S(cp), the selection of detector type for Sc is not critical, provided the active dosimeter volume is small relative to the field size.

  9. Systematic comparative validation of self-report measures of sedentary time against an objective measure of postural sitting (activPAL).

    Science.gov (United States)

    Chastin, S F M; Dontje, M L; Skelton, D A; Čukić, I; Shaw, R J; Gill, J M R; Greig, C A; Gale, C R; Deary, I J; Der, G; Dall, P M

    2018-02-26

    Sedentary behaviour is a public health concern that requires surveillance and epidemiological research. For such large scale studies, self-report tools are a pragmatic measurement solution. A large number of self-report tools are currently in use, but few have been validated against an objective measure of sedentary time and there is no comparative information between tools to guide choice or to enable comparison between studies. The aim of this study was to provide a systematic comparison, generalisable to all tools, of the validity of self-report measures of sedentary time against a gold standard sedentary time objective monitor. Cross sectional data from three cohorts (N = 700) were used in this validation study. Eighteen self-report measures of sedentary time, based on the TAxonomy of Self-report SB Tools (TASST) framework, were compared against an objective measure of postural sitting (activPAL) to provide information, generalizable to all existing tools, on agreement and precision using Bland-Altman statistics, on criterion validity using Pearson correlation, and on data loss. All self-report measures showed poor accuracy compared with the objective measure of sedentary time, with very wide limits of agreement and poor precision (random error > 2.5 h). Most tools under-reported total sedentary time and demonstrated low correlations with objective data. The type of assessment used by the tool, whether direct, proxy, or a composite measure, influenced the measurement characteristics. Proxy measures (TV time) and single item direct measures using a visual analogue scale to assess the proportion of the day spent sitting, showed the best combination of precision and data loss. The recall period (e.g. previous week) had little influence on measurement characteristics. Self-report measures of sedentary time result in large bias, poor precision and low correlation with an objective measure of sedentary time. Choice of tool depends on the research context

  10. On the Measurement of Procrastination: Comparing Two Scales in Six European Countries.

    Science.gov (United States)

    Svartdal, Frode; Pfuhl, Gerit; Nordby, Kent; Foschi, Gioel; Klingsieck, Katrin B; Rozental, Alexander; Carlbring, Per; Lindblom-Ylänne, Sari; Rębkowska, Kaja

    2016-01-01

    Procrastination is a common problem, but defining and measuring it has been subject to some debate. This paper summarizes results from students and employees (N = 2893) in Finland, Germany, Italy, Norway, Poland, and Sweden using the Pure Procrastination Scale (PPS) and the Irrational Procrastination Scale (IPS; Steel, 2010), both assumed to measure unidimensional and closely related constructs. Confirmatory factor analyses indicated inadequate configural fit for the suggested one-factor model for PPS; however, acceptable fit was observed for a three-factor model corresponding to the three different scales the PPS is based on. Testing measurement invariance over countries and students-employees revealed configural but not strong or strict invariance, indicating that both instruments are somewhat sensitive to cultural differences. We conclude that the PPS and IPS are valid measures of procrastination, and that the PPS may be particularly useful in assessing cultural differences in unnecessary delay.

  11. On the measurement of procrastination: Comparing two scales in six European countries

    Directory of Open Access Journals (Sweden)

    Frode Svartdal

    2016-08-01

    Full Text Available Procrastination is a common problem, but defining and measuring it has been subject to some debate. This paper summarizes results from students and employees (N = 2893 in Finland, Germany, Italy, Norway, Poland and Sweden using the Pure Procrastination Scale (PPS and the Irrational Procrastination Scale (IPS (Steel, 2010, both assumed to measure unidimensional and closely related constructs. Confirmatory factor analyses (CFA indicated inadequate configural fit for the suggested one-factor model for PPS; however, acceptable fit was observed for a three-factor model corresponding to the three different scales the PPS is based on. Testing measurement invariance over countries and students-employees revealed configural but not strong or strict invariance, indicating that both instruments are somewhat sensitive to cultural differences. We conclude that the PPS and IPS are valid measures of procrastination, and that the PPS may be particularly useful in assessing cultural differences in unnecessary delay.

  12. Comparative analysis of two methods for measuring sales volumes during malaria medicine outlet surveys

    OpenAIRE

    Patouillard, Edith; Kleinschmidt, Immo; Hanson, Kara; Pok, Sochea; Palafox, Benjamin; Tougher, Sarah; O?Connell, Kate; Goodman, Catherine

    2013-01-01

    BACKGROUND There is increased interest in using commercial providers for improving access to quality malaria treatment. Understanding their current role is an essential first step, notably in terms of the volume of diagnostics and anti-malarials they sell. Sales volume data can be used to measure the importance of different provider and product types, frequency of parasitological diagnosis and impact of interventions. Several methods for measuring sales volumes are available, yet all have met...

  13. Process measures or patient reported experience measures (PREMs) for comparing performance across providers? A study of measures related to access and continuity in Swedish primary care.

    Science.gov (United States)

    Glenngård, Anna H; Anell, Anders

    2018-01-01

    Aim To study (a) the covariation between patient reported experience measures (PREMs) and registered process measures of access and continuity when ranking providers in a primary care setting, and (b) whether registered process measures or PREMs provided more or less information about potential linkages between levels of access and continuity and explaining variables. Access and continuity are important objectives in primary care. They can be measured through registered process measures or PREMs. These measures do not necessarily converge in terms of outcomes. Patient views are affected by factors not necessarily reflecting quality of services. Results from surveys are often uncertain due to low response rates, particularly in vulnerable groups. The quality of process measures, on the other hand, may be influenced by registration practices and are often more easy to manipulate. With increased transparency and use of quality measures for management and governance purposes, knowledge about the pros and cons of using different measures to assess the performance across providers are important. Four regression models were developed with registered process measures and PREMs of access and continuity as dependent variables. Independent variables were characteristics of providers as well as geographical location and degree of competition facing providers. Data were taken from two large Swedish county councils. Findings Although ranking of providers is sensitive to the measure used, the results suggest that providers performing well with respect to one measure also tended to perform well with respect to the other. As process measures are easier and quicker to collect they may be looked upon as the preferred option. PREMs were better than process measures when exploring factors that contributed to variation in performance across providers in our study; however, if the purpose of comparison is continuous learning and development of services, a combination of PREMs and

  14. Comparing emissions from a cattle pen as measured by two micrometeorological techniques.

    Science.gov (United States)

    Bai, Mei; Sun, Jianlei; Denmead, Owen T; Chen, Deli

    2017-11-01

    Accurate measurement of ammonia (NH 3 ) emissions from livestock pens is challenging. Two micrometeorological techniques, the integrated horizontal flux (IHF) and the backward Lagrangian stochastic (bLS) dispersion techniques were used to measure NH 3 emissions from an isolated cattle pen (20 × 20 m) in Victoria, Australia. The bLS technique is simple and insensitive to the presence of animals, but typically gives discontinuous measurements due to the need for target wind directions and wind conditions above accepted thresholds. In contrast, the IHF technique as implemented here gives near-continuous measurements with no restriction on wind directions. However, IHF needs more complex field measurements, and there are ambiguities when applied to an animal pen due to the presence of animals. Over the 29 days of our experiment, we collected 124 coincidental bLS and IHF emission measurements from the pen (30-min each). We found no statistical difference in the bLS and IHF calculations when the IHF turbulent flux correction factor (TF cor ) was set to 15%. Our results confirm that the IHF and bLS techniques, using independent sensors and having very different equipment layouts, gives nearly equivalent results. This suggests the choice of the two methods in future experiments can focus on their different strengths and weaknesses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Civil liability in air transport

    OpenAIRE

    Jiménez Ramírez, Jessica Alejandra

    2017-01-01

    Civil liability in air transport has been the response to a fact adversely affecting both people involved in this type of transport and people unrelated to it, as its goal is to repair the damage arising from the use of air transport, which makes the operator compensate the injured party. In this sense, civil liability in transport arises as a consequence of non-compliance or reasons unrelated to the parties (act of God, major force) originating the damage. La responsabilidad civil en el t...

  16. 24 h stability of thick multilayer silicene in air

    International Nuclear Information System (INIS)

    De Padova, Paola; Ottaviani, Carlo; Quaresima, Claudio; Generosi, Amanda; Paci, Barbara; Le Lay, Guy; Olivieri, Bruno; Imperatori, Patrizia; Salomon, Eric; Angot, Thierry; Quagliano, Lucia; Romano, Claudia; Vona, Alessandro; Muniz-Miranda, Maurizio

    2014-01-01

    Thick epitaxial multilayer silicene films with a √3 × √3R(30°) surface structure show only mild surface oxidation after 24 h in air, as measured by Auger electron spectroscopy. X-ray diffraction and Raman spectroscopy measurements performed in air without any protective capping, as well as, for comparison, with a thin Al 2 O 3 cap, showed the (002) reflection and the G, D and 2D Raman structures, which are unique fingerprints of thick multilayer silicene. (letter)

  17. Presence of organophosphorus pesticide oxygen analogs in air samples

    Science.gov (United States)

    Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

    2013-02-01

    A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (<30 ng m-3) typical of ambient or residential levels. Overall, the 2008 study data had significantly greater oxon than expected by artificial transformation, but the exact amount of environmental oxon in air remains difficult to quantify with the current sampling method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity

  18. Comparative study of elemental mercury flux measurement techniques over a Fennoscandian boreal peatland

    Science.gov (United States)

    Osterwalder, S.; Sommar, J.; Åkerblom, S.; Jocher, G.; Fritsche, J.; Nilsson, M. B.; Bishop, K.; Alewell, C.

    2018-01-01

    Quantitative estimates of the land-atmosphere exchange of gaseous elemental mercury (GEM) are biased by the measurement technique employed, because no standard method or scale in space and time are agreed upon. Here we present concurrent GEM exchange measurements over a boreal peatland using a novel relaxed eddy accumulation (REA) system, a rectangular Teflon® dynamic flux chamber (DFC) and a DFC designed according to aerodynamic considerations (Aero-DFC). During four consecutive days the DFCs were placed alternately on two measurement plots in every cardinal direction around the REA sampling mast. Spatial heterogeneity in peat surface characteristics (0-34 cm) was identified by measuring total mercury in eight peat cores (57 ± 8 ng g-1, average ± SE), vascular plant coverage (32-52%), water table level (4.5-14.1 cm) and dissolved gaseous elemental mercury concentrations (28-51 pg L-1) in the peat water. The GEM fluxes measured by the DFCs showed a distinct diel pattern, but no spatial difference in the average fluxes was detected (ANOVA, α = 0.05). Even though the correlation between the Teflon® DFC and Aero-DFC was significant (r = 0.76, p scale features, such as experimentally manipulated plots or small scale spatial heterogeneity.

  19. In-air ion beam analysis with high spatial resolution proton microbeam

    Energy Technology Data Exchange (ETDEWEB)

    Jakšić, M.; Chokheli, D.; Fazinić, S.; Grilj, V.; Skukan, N.; Sudić, I.; Tadić, T.; Antičić, T.

    2016-03-15

    One of the possible ways to maintain the micrometre spatial resolution while performing ion beam analysis in the air is to increase the energy of ions. In order to explore capabilities and limitations of this approach, we have tested a range of proton beam energies (2–6 MeV) using in-air STIM (Scanning Ion Transmission Microscopy) setup. Measurements of the spatial resolution dependence on proton energy have been compared with SRIM simulation and modelling of proton multiple scattering by different approaches. Results were used to select experimental conditions in which 1 micrometre spatial resolution could be obtained. High resolution in-air microbeam could be applied for IBIC (Ion Beam Induced Charge) tests of large detectors used in nuclear and high energy physics that otherwise cannot be tested in relatively small microbeam vacuum chambers.

  20. Comparability of slack water and Lagrangian flow respirometry methods for community metabolic measurements.

    Directory of Open Access Journals (Sweden)

    Emily C Shaw

    Full Text Available Coral reef calcification is predicted to decline as a result of ocean acidification and other anthropogenic stressors. The majority of studies predicting declines based on in situ relationships between environmental parameters and net community calcification rate have been location-specific, preventing accurate predictions for coral reefs globally. In this study, net community calcification and production were measured on a coral reef flat at One Tree Island, Great Barrier Reef, using Lagrangian flow respirometry and slack water methods. Net community calcification, daytime net photosynthesis and nighttime respiration were higher under the flow respirometry method, likely due to increased water flow relative to the slack water method. The two methods also varied in the degrees to which they were influenced by potential measurement uncertainties. The difference in the results from these two commonly used methods implies that some of the location-specific differences in coral reef community metabolism may be due to differences in measurement methods.

  1. Comparative Analysis of Direct and Indirect 131I Measurement Methods from the Stack to Outdoor

    Directory of Open Access Journals (Sweden)

    G. Suhariyono

    2017-11-01

    Full Text Available The radioisotope production facility at PUSPIPTEK Serpong produces and processes 131I that can disperse to the settlements (community and the environment around the Serpong Nuclear Area (SNA. 131I is produced routinely for medical uses in hospitals and pharmacies, for both domestic uses and export. 131I is a beta and gamma emitting radioactive material and can cause thyroid cancer. The problem was that there was so far no research and in-depth assessment of the aerial dispersion of 131I radioactivity emitted from the radioisotope production stack to the environment at actual conditions. The research was conducted through simultaneous measurement of 131I radioactivity in the stack of the 131I radioisotope production facility, Serpong, and outdoor in house courtyards around SNA in normal condition (no accident based on the variations of the distance and wind direction. Direct measurements were carried out with a portable in-situ NaI(Tl detector at outdoor, and with a LaBr3 detector in the stack. Indirect measurements were carried out by using charcoal filter and vacuum pump in the stack and outdoor. The direct measurement method has many advantages over the indirect measurement. The direct measurement method was found to be more accurate, less expensive, easier to operate, needing just one operator in its implementation, portable, and can be operated continuously and for long durations. The overall activity concentrations of 131I on average obtained by either direct or indirect method were still below the upper limit of 131I activity concentration in the air (530 Bq/m3 stipulated by the Regulation of the Chairman of BAPETEN (Perka BAPETEN No. 7/2013. 

  2. Comparability of the Patient-Reported Outcomes Measurement Information System Pediatric short form symptom measures across culture: examination between Chinese and American children with cancer.

    Science.gov (United States)

    Liu, Yanyan; Yuan, Changrong; Wang, Jichuan; Brown, Jeanne Geiger; Zhou, Fen; Zhao, Xiufang; Shen, Min; Hinds, Pamela S

    2016-10-01

    Patient-Reported Outcomes Measurement Information System (PROMIS) Pediatric forms measure symptoms and function of pediatric patients experiencing chronic disease by using the same measures. Comparability is one of the most important purposes of the PROMIS initiative. This study aimed to test the factorial structures of four symptom measures (i.e., Anxiety, Depression, Fatigue, and Pain Interference) in the original English and the Chinese versions and examine the measurement invariance of the measures across two cultures. Four PROMIS Pediatric measures were used to assess symptoms, respectively, in Chinese (n = 232) and American (n = 200) children and adolescents (8-17 years old) in treatment for cancer or in survivorship. The categorical confirmatory factor analysis (CCFA) model was used to examine factorial structures, and multigroup CCFA was applied to test measurement invariance of these measures between the Chinese and American samples. The CCFA models of the four PROMIS Pediatric symptom measures fit the data well for both the Chinese and American children and adolescents. Minor partial measurement invariance was identified. Factor means and factor variances of the four PROMIS measures were not significantly different between the two populations. Our results provide evidence that the four PROMIS Pediatric symptom measures have valid factorial structures and a statistical property of measurement invariance across American and Chinese children and adolescents with cancer. This means that the items of these measures were interpreted in a conceptually similar manner by two groups. They could be readily used for meaningful cross-cultural comparisons involving pediatric oncology patients in these two countries.

  3. The reliability and reproducibility of foot type measurements using a mirrored foot photo box and digital photography compared to caliper measurements.

    Science.gov (United States)

    Mall, Nathan A; Hardaker, W Mack; Nunley, James A; Queen, Robin M

    2007-01-01

    The height of the medial longitudinal arch (MLA) is thought to be a predisposing factor to various lower extremity injuries. Discrepancy exists as to whether MLA height plays a role in injury prevention. The purpose of this study was to determine the intertester and intratester reliability, and the validity of the mirrored foot photo box (MFPB) and caliper measurements to radiographic measurements. Thirty subjects with equal numbers of men and women were recruited. Both feet were tested (n=60) in a 90% weight bearing stance. A set of anatomic landmarks were palpated, marked, and measured using a caliper, MFPB, and radiographs. The protocol was completed by two testers on 2 days approximately 1 week apart. Intertester and intratester reliability were determined using the intraclass correlation coefficient (ICC)(2,k) and the ICC(2,1), respectively. Validity of both measurement techniques to radiographic measurements was determined using the ICC(2,k). The intertester reliability ranged from 0.991 to 0.577, while the intratester reliability ranged from 0.994 to 0.527, with first metatarsal angle being the only variable with poor reliability. Most variables demonstrated acceptable validity between the MFPB and the caliper measurements, and acceptable validity between the MFPB and calipers compared to radiographic measurements. The MFPB took 51.3+/-19.6s per foot while the caliper measurements averaged 227.4+/-68.9s to complete the measurements. The MFPB is as reliable as the caliper measurements, and offers better intertester reliability. Both the caliper and MFPB measurements demonstrated acceptable validity to radiographic measurements and testing time was reduced when using the MFPB compared to calipers.

  4. MEASUREMENT OF COMPARATIVE ADVANTAGES OF PROCESSED FOOD SECTOR OF SERBIA IN THE INCREASING THE EXPORT

    OpenAIRE

    Ignjatijević, Svetlana; Čavlin, Miroslav; Đorđević, Dragomir

    2014-01-01

    The subject of this research is to analyse the comparative advantages of export of processed food sector, in order to define the position of the processed food sector in Serbia in compare to the Danube region and highlight the products that were and will be the main exporting agricultural product of Serbia. In this research, we have applied the following indexes: RXA, RTA, ln RXA, RC, RCA, LFI, GL, Sm. We have examined the movement of the index for the period 2005 - 2011th year. We have inves...

  5. Piers Harris and Coopersmith Measure of Self-Esteem: A Comparative Analysis

    Science.gov (United States)

    Lynch, Mervin D.; Foley-Peres, Kathleen D.; Sullivan, Stefanie S.

    2008-01-01

    The purposes of this study were to see if the items from the Piers Harris Self Concept Scale and the Coopersmith Self Esteem Inventory had construct and predictive validity. Items used in this study were 50 items from the Coopersmith Self-Esteem Inventory and 80 items from the Piers Harris Self-Concept Scale. Construct measures were obtained using…

  6. Comparative evaluation of quantitative glomerular filtration rate measured by isotopic and nonisotopic methods

    International Nuclear Information System (INIS)

    Balachandran, S.; Toguri, A.G.; Petrusick, T.W.; Abbott, L.C.

    1981-01-01

    Good correlation of glomerular filtration rate (GFR) measured isotopically from plasma disappearance of Tc-99m-DTPA (Sn) was shown with inulin clearance, creatinine clearance, and graded radionuclide imaging. The isotopic GFR is a simple, urineless technique not requiring continuous infusion that enables one to perform simultaneous renal imaging with one radiotracer

  7. A Comparative Analysis of Computed and Measured SAR Images of Complex Targets

    Science.gov (United States)

    2012-05-01

    catamaran ferry, “HSC Alboran”, showing the actual configuration. Figure 5: CAD model of the catamaran ferry HCS Alboran; top: original model, bottom...range 4.4 “Alboran”, a catamaran ferry Figure 21: Two measured SAR images of the catamaran ferry, “Alboran”; image captured at

  8. Comparative Measurements of ITER Nb3Sn Strands between Two Laboratories

    NARCIS (Netherlands)

    Lu, Jun; Hill, Scott; McGuire, David; Dellinger, Keagan; Nijhuis, Arend; Wessel, W. A.; Krooshoop, H. J.G.; Chan, Kevin; Martovetsky, Nicolai

    2017-01-01

    ITER Nb3Sn strand quality verification tests require large quantities of precise measurements. Therefore, regular cross-checking between testing laboratories is critically important. In this paper, we present results from a cross-checking test of 140 samples between the National High Magnetic Field

  9. Measuring Creative Capacity in Gifted Students: Comparing Teacher Ratings and Student Products

    Science.gov (United States)

    Kettler, Todd; Bower, Janessa

    2017-01-01

    Creativity and giftedness are frequently associated, and schools may use measures of creativity for identifying gifted and talented students. The researchers examined three aspects of elementary student creativity: (a) the relationship between a teacher's rating of student creativity and rubric-scored student writing samples, (b) group differences…

  10. Different Gestalt Processing for Different Actions? Comparing Object-Directed Reaching and Looking Time Measures

    Science.gov (United States)

    Vishton, P.M.; Ware, E.A.; Badger, A.N.

    2005-01-01

    Six experiments compared the Gestalt processing that mediates infant reaching and looking behaviors. Experiment 1 demonstrated that the positioning and timing of 8- and 9-month-olds' reaching was influenced by remembered relative motion. Experiment 2 suggested that a visible gap, without this relative motion, was not sufficient to produce these…

  11. Measuring Teacher Classroom Management Skills: A Comparative Analysis of Distance Trained and Conventional Trained Teachers

    Science.gov (United States)

    Henaku, Christina Bampo; Pobbi, Michael Asamani

    2017-01-01

    Many researchers and educationist remain skeptical about the effectiveness of distance learning program and have termed it as second to the conventional training method. This perception is largely due to several challenges which exist within the management of distance learning program across the country. The general aim of the study is compare the…

  12. Child Immunization Status among a Sample of Adolescent Mothers: Comparing the Validity of Measurement Strategies

    Science.gov (United States)

    Phillips, Clarissa; Cota-Robles, Sonia; Knight, Margaret; Francis, Judith; Phillips, Elizabeth; Mazerbo, Laurie

    2011-01-01

    This study of adolescent mothers sought to identify whether a single general question asked by phone or a detailed, vaccine-specific question asked in a self-report questionnaire best captured infant immunization status at 6 months postpartum, by comparing them with immunization record books. Responses to a global question about whether infants…

  13. A comparative measurement technique of nanoparticle heating for magnetic hyperthermia applications

    Science.gov (United States)

    Drayton, A.; Zehner, J.; Timmis, J.; Patel, V.; Vallejo-Fernandez, G.; O’Grady, K.

    2017-12-01

    We describe a method for the determination of the heating power of magnetic nanoparticle colloids which have potential for application in the remedial treatment of malignant and non-malignant tumours. The method is based upon a comparison between the heating power observed when the colloid is exposed to a radio frequency magnetic field and that which is observed using a resistive electrical heater. A new design of the measurement cell has been made which has the advantages of reducing or eliminating the effects of convection, ensuring the measurement is made in a magnetic field of known uniformity and that the heat losses in the system are constant and minimized under both magnetic and Joule heating.

  14. Comparing Jupiter interior structure models to Juno gravity measurements and the role of a dilute core

    Science.gov (United States)

    Wahl, S. M.; Hubbard, W. B.; Militzer, B.; Guillot, T.; Miguel, Y.; Movshovitz, N.; Kaspi, Y.; Helled, R.; Reese, D.; Galanti, E.; Levin, S.; Connerney, J. E.; Bolton, S. J.

    2017-05-01

    The Juno spacecraft has measured Jupiter's low-order, even gravitational moments, J2-J8, to an unprecedented precision, providing important constraints on the density profile and core mass of the planet. Here we report on a selection of interior models based on ab initio computer simulations of hydrogen-helium mixtures. We demonstrate that a dilute core, expanded to a significant fraction of the planet's radius, is helpful in reconciling the calculated Jn with Juno's observations. Although model predictions are strongly affected by the chosen equation of state, the prediction of an enrichment of Z in the deep, metallic envelope over that in the shallow, molecular envelope holds. We estimate Jupiter's core to contain a 7-25 Earth mass of heavy elements. We discuss the current difficulties in reconciling measured Jn with the equations of state and with theory for formation and evolution of the planet.

  15. Comparative investigation of optical techniques for topography measurement of rough plastic surfaces

    DEFF Research Database (Denmark)

    Bariani, Paolo; Hansen, Hans Nørgaard; Arlø, Uffe Rolf

    2003-01-01

    An experimental assessment of three-dimensional surface topography characterisation methods for use with rough plastic parts has been carried out. Also, calibration methods and measuring procedures including optimal measuring conditions have been developed and applied. The study is based on rough...... polypropylene parts manufactured by injection moulding. The mould was equipped with inserts with EDM machined surfaces (Sa  3.5 µm) in order to represent a typical tool surface for injection moulding. A focus detection laser scanning profiler, a confocal scanning laser microscope, a white light interferometer...... and, in addition, a scanning electron microscope, have been used in the analysis of plastic surfaces. This investigation has shown that topography assessment of rough plastic surfaces is critical to both white light interference microscope and confocal microscope while the focus detection laser...

  16. Comparative speaking, shouting and singing voice range profile measurement: physiological and pathological aspects.

    Science.gov (United States)

    Hacki, T

    1996-01-01

    The Voice Range Profile (VRP) measurement offers a method for the investigation of voice modalities i.e. speaking voice, shouting voice and singing voice in their mutual pitch and intensity relations. The parameters FO and SPL are evaluated by means of automatic pitch and SPL measurements from (1) sustained phonation /a:/ in the speaker's natural pitch and intensity range, (2) the continuous speaking voice beginning with Pianissimo up to Fortissimo, (3) the shouting voice. Vocal intensity is plotted vertically, vocal pitch horizontally. The displays of the vocal intensity versus fundamental frequency are defined as singing voice range profile (VRP), speaking VRP and shouting VRP. The VRPs are superimposed on the same plot. Their form, their shape and their position to each other are analysed. The physiological relationships between the VRPs of the different voice modalities to each other are defined. The pathological relationships between the VRPs (i.e. reduction, shifting) give information about etiology and pathomechanism of voice disorders.

  17. Modeling the natural UV irradiation and comparative UV measurements at Moussala BEO (BG)

    Science.gov (United States)

    Tyutyundzhiev, N.; Angelov, Ch; Lovchinov, K.; Nitchev, Hr; Petrov, M.; Arsov, T.

    2018-03-01

    Studies of and modeling the impact of natural UV irradiation on the human population are of significant importance for human activity and economics. The sharp increase of environmental problems – extraordinary temperature changes, solar irradiation abnormalities, icy rains – raises the question of developing novel means of assessing and predicting potential UV effects. In this paper, we discuss new UV irradiation modeling based on recent real-time measurements at Moussala Basic Environmental Observatory (BEO) on Moussala Peak (2925 m ASL) in Rila Mountain, Bulgaria, and highlight the development and initial validation of portable embedded devices for UV-A, UV-B monitoring using open-source software architecture, narrow bandpass UV sensors, and the popular Arduino controllers. Despite the high temporal resolution of the VIS and UV irradiation measurements, the results obtained reveal the need of new assumptions in order to minimize the discrepancy with available databases.

  18. ANITA Air Monitoring on the International Space Station: Results Compared to Other Measurements

    Science.gov (United States)

    Honne, A.; Schumann-Olsen, H.; Kaspersen, K.; Limero, T.; Macatangay, A.; Mosebach, H.; Kampf, D.; Mudgett, P. D.; James, J. T.; Tan, G.; hide

    2009-01-01

    ANITA (Analysing Interferometer for Ambient Air) is a flight experiment precursor for a permanent continuous air quality monitoring system on the ISS (International Space Station). For the safety of the crew, ANITA can detect and quantify quasi-online and simultaneously 33 gas compounds in the air with ppm or sub-ppm detection limits. The autonomous measurement system is based on FTIR (Fourier Transform Infra-Red spectroscopy). The system represents a versatile air quality monitor, allowing for the first time the detection and monitoring of trace gas dynamics in a spacecraft atmosphere. ANITA operated on the ISS from September 2007 to August 2008. This paper summarizes the results of ANITA s air analyses with emphasis on comparisons to other measurements. The main basis of comparison is NASA s set of grab samples taken onboard the ISS and analysed on ground applying various GC-based (Gas Chromatography) systems.

  19. Comparing three gap filling methods for eddy covariance crop evapotranspiration measurements within a hilly agricultural catchment

    Science.gov (United States)

    Boudhina, Nissaf; Prévot, Laurent; Zitouna Chebbi, Rim; Mekki, Insaf; Jacob, Frédéric; Ben Mechlia, Netij; Masmoudi, Moncef

    2015-04-01

    Hilly watersheds are widespread throughout coastal areas around the Mediterranean Basin. They experience agricultural intensification since hilly topographies allow water-harvesting techniques that compensate for rainfall storage, water being a strong limiting factor for crop production. Their fragility is likely to increase with climate change and human pressure. Within semi-arid hilly watershed conditions, evapotranspiration (ETR) is a major term of both land surface energy and water balances. Several methods allow determining ETR, based either on direct measurements, or on estimations and forecast from weather and soil moisture data using simulation models. Among these methods, eddy covariance technique is based on high-frequency measurements of fluctuations of wind speed and air temperature / humidity, to directly determine the convective fluxes between land surface and atmosphere. In spite of experimental and instrumental progresses, datasets of eddy covariance measurements often experience large portions of missing data. The latter results from energy power failure, experimental maintenance, instrumental troubles such as krypton hygrometer malfunctioning because of air humidity, or quality assessment based filtering in relation to spatial homogeneity and temporal stationarity of turbulence within surface boundary layer. This last item is all the more important as hilly topography, when combined with strong winds, tends to increase turbulence within surface boundary layer. The main objective of this study is to establish gap-filling procedures to provide complete chronicles of eddy-covariance measurements of crop evapotranspiration (ETR) within a hilly agricultural watershed. We focus on the specific conditions induced by the combination of hilly topography and wind direction, by discriminating between upslope and downslope winds. The experiment was set for three field configurations within hilly conditions: two flux measurement stations (A, B) were installed

  20. Comparative study of outcome measures and analysis methods for traumatic brain injury trials.

    Science.gov (United States)

    Alali, Aziz S; Vavrek, Darcy; Barber, Jason; Dikmen, Sureyya; Nathens, Avery B; Temkin, Nancy R

    2015-04-15

    Batteries of functional and cognitive measures have been proposed as alternatives to the Extended Glasgow Outcome Scale (GOSE) as the primary outcome for traumatic brain injury (TBI) trials. We evaluated several approaches to analyzing GOSE and a battery of four functional and cognitive measures. Using data from a randomized trial, we created a "super" dataset of 16,550 subjects from patients with complete data (n=331) and then simulated multiple treatment effects across multiple outcome measures. Patients were sampled with replacement (bootstrapping) to generate 10,000 samples for each treatment effect (n=400 patients/group). The percentage of samples where the null hypothesis was rejected estimates the power. All analytic techniques had appropriate rates of type I error (≤5%). Accounting for baseline prognosis either by using sliding dichotomy for GOSE or using regression-based methods substantially increased the power over the corresponding analysis without accounting for prognosis. Analyzing GOSE using multivariate proportional odds regression or analyzing the four-outcome battery with regression-based adjustments had the highest power, assuming equal treatment effect across all components. Analyzing GOSE using a fixed dichotomy provided the lowest power for both unadjusted and regression-adjusted analyses. We assumed an equal treatment effect for all measures. This may not be true in an actual clinical trial. Accounting for baseline prognosis is critical to attaining high power in Phase III TBI trials. The choice of primary outcome for future trials should be guided by power, the domain of brain function that an intervention is likely to impact, and the feasibility of collecting outcome data.

  1. Comparative measurement of irritant properties of toilet bar soaps on human skin

    Directory of Open Access Journals (Sweden)

    Sanjay Singh

    1990-01-01

    Full Text Available Ten commonly used toilet bar soaps were tested for their respective irritancies usin Kligman.and Wooding′s technique of . 9 evaluation of mild irritants of human skin. Five per cent soap soulations were prepared and their pH measured, IT 50 and irritancy scores were calculated. There was to correlation between pH and IT 50 or irritancy scores and lux pink was least irritant followed by New Cinthol, Pears and lifebuoy.

  2. Baseline Measurements of Shoulder Surfing Analysis and Comparability for Smartphone Unlock Authentication

    Science.gov (United States)

    2017-05-22

    In this research, we explore a novel approach to measuring the susceptibility of smarthphone unlock authentication to shoulder surfing attacks. We...have created a series of video recordings where researchers enter authentication sequences into mobile devices (e.g. PINs, graphical patterns with...and played the role of attackers, viewing video-recorded footage of PIN and graphical pattern authentication input with various camera angles, hand

  3. Comparing the Self-Report and Measured Smartphone Usage of College Students: A Pilot Study

    OpenAIRE

    Lee, Heyoung; Ahn, Heejune; Nguyen, Trung Giang; Choi, Sam-Wook; Kim, Dae Jin

    2017-01-01

    Objective Nowadays smartphone overuse has become a social and medical concern. For the diagnosis and treatment, clinicians use the self-report information, but the report data often does not match actual usage pattern. The paper examines the similarity and variance in smartphone usage patterns between the measured data and self-reported data. Methods Together with the self-reported data, the real usage log data is collected from 35 college students in a metropolitan region of Northeast Asia, ...

  4. Aortic Measurements in Patients with Aortopathy are Larger and More Reproducible by Cardiac Magnetic Resonance Compared with Echocardiography.

    Science.gov (United States)

    Nejatian, Atosa; Yu, Johan; Geva, Tal; White, Matthew T; Prakash, Ashwin

    2015-12-01

    Accurate and reproducible aortic measurements are essential in aortopathy patients. Transthoracic echocardiography (TTE) is commonly used but has several limitations. Cardiac magnetic resonance (CMR) can offset these limitations but has not been directly compared with TTE. We compared the reproducibility of CMR and TTE measurements at multiple aortic levels. Patients with a connective tissue disorder (CTD) or bicommissural aortic valve (BAV) (n = 41; 22 CTD, 19 BAV; mean age 18.8 ± 8.9 years) with TTE and CMR imaging performed within 3 months of each other were randomly selected. Two blinded observers measured the aorta at multiple anatomic levels. Intra- and interobserver variability and agreement between techniques were assessed. Aortic root diameter measurements by TTE and CMR were equally reproducible (% error 4-10 %), but TTE measurements were systematically smaller by 5-7 % (p TTE were less reproducible, especially in BAV (% error 21-24 vs. 6-7 %, p = 0.01). Distal aortic measurements by TTE were 14-29 % smaller and had poor reproducibility compared with CMR (% error 24-42 vs. 9-10 %; p TTE, especially when the root is asymmetric. Measurements of the thoracic aorta distal to the root by CMR are more accurate and reproducible than by TTE. These data support a role for CMR in aortopathy patients.

  5. Comparative study of measurement of the normal retrogastric space of Korean adults

    International Nuclear Information System (INIS)

    Kim, Y. C.; Kim, Y. S.; Lee, Y. K.; Lee, D. Y.

    1979-01-01

    Though it may be equivocal in the obese patients, the measurement of the retrogastric space is still helpful in the early detection of retroperitoneal masses, such as carcinoma of the pancreas especially in the body and tail of the pancreas. Recently te best method or detect a retroperitoneal mass is, of course, Computed Tomography. But its application to every patient complaining epigastric distress is almost impossible because of its high cost. In those cases the measurement of the retrogastric space is advisable on the erect left lateral film checked during ordinary upper G-I series as a screening test. New method to measure the retrogastric space is proposed, and its relationship to the body thickness is studied. The results are follows: 1. The total number of the patient was 120 and sex distribution was 56 males and 64 females. 2. The retrogastric space and the retropyloric space had a close relationship with the thickness of the body. 3. The average ratio of the retrogastric space to the body thickness was 48.9 ± 8.4% in male and 43.3 ± 10.1 in female. 4. The average ratio of the retropyloric space to the body thickness was 38.6 ± 7.9% in male and 34.9 ± 9.1 in female. 5. The distance of the Treitz ligament from the fundus of the stomach had no relationship with the body thickness.

  6. Comparing the Self-Report and Measured Smartphone Usage of College Students: A Pilot Study.

    Science.gov (United States)

    Lee, Heyoung; Ahn, Heejune; Nguyen, Trung Giang; Choi, Sam-Wook; Kim, Dae Jin

    2017-03-01

    Nowadays smartphone overuse has become a social and medical concern. For the diagnosis and treatment, clinicians use the self-report information, but the report data often does not match actual usage pattern. The paper examines the similarity and variance in smartphone usage patterns between the measured data and self-reported data. Together with the self-reported data, the real usage log data is collected from 35 college students in a metropolitan region of Northeast Asia, using Android smartphone monitoring application developed by the authors. The unconscious users underestimate their usage time by 40%, in spite of 15% more use in the actual usage. Messengers are most-used application regardless of their self-report, and significant preference to SNS applications was observed in addict group. The actual hourly pattern is consistent with the reported one. College students use more in the afternoon, when they have more free time and cannot use PCs. No significant difference in hourly pattern is observed between the measured and self-report. The result shows there are significant cognitive bias in actual usage patterns exists in self report of smartphone addictions. Clinicians are recommended to utilize measurement tools in diagnosis and treatment of smartphone overusing subjects.

  7. Comparing traditional AP classes to portfolio AP classes in effectiveness of measuring knowledge.

    Directory of Open Access Journals (Sweden)

    Olona, L.

    2017-07-01

    Full Text Available High school students across the United States and internationally take Advanced Placement exams in May each year. These students also spend their school year enrolled in an Advanced Placement (AP class in preparation for the exam. There is a lack of research on any correlation between a student’s performance in class and performance on the exam. This study aims to compare the difference in correlation between traditional AP classes and portfolio AP classes. Second-semester grades and exam scores were collected from 2015 and 2016 from Norman High School students. Traditional classes had weak, if any, correlation, and portfolio classes presented no correlation. This lack of a relationship between class grade and exam score implies that students are unable to gauge their future exam performance based on class performance. Future researchers should compare data for a greater sample of students as well as regional samples.

  8. On a comparative study between dependence scales determined by linear and non-linear measures

    OpenAIRE

    Queiros, Silvio M. Duarte

    2008-01-01

    In this manuscript we present a comparative study about the determination of the relaxation (\\textit{i.e.}, independence) time scales obtained from the correlation function, the mutual information, and a criterion based on the evaluation of a nonextensive generalisation of mutual entropy. Our results show that, for systems with a small degree of complexity, standard mutual information and the criterion based on its nonextensive generalisation provide the same scale, whereas for systems with a...

  9. Comparative study of on-line response time measurement methods for platinum resistance thermometer

    International Nuclear Information System (INIS)

    Zwingelstein, G.; Gopal, R.

    1979-01-01

    This study deals with the in site determination of the response time of platinum resistance sensor. In the first part of this work, two methods furnishing the reference response time of the sensors are studied. In the second part of the work, two methods obtaining the response time without dismounting of the sensor, are studied. A comparative study of the performances of these methods is included for fluid velocities varying from 0 to 10 m/sec, in both laboratory and plant conditions

  10. Two period measures for comparing the fertility of marriage and cohabitation

    Directory of Open Access Journals (Sweden)

    Benoît Laplante

    2015-02-01

    Full Text Available Background: The diffusion of cohabitation and, presumably, of childbearing within cohabitation, inspires interest in measuring the respective contribution of childbearing within marriage and within cohabitation to overall fertility. However, there is no consensus on a proper way to do so. Objective: Contribute to the development of tools for assessing the relative importance of marriage and cohabitation to overall fertility by developing period measures closely related to age-specific fertility rates and the total fertility rate. Methods: We introduce two measures: 1 the contribution of the conjugal state (living alone, living in a cohabiting union, being married to age-specific fertility rates (CASFR and 2 the contribution of the conjugal state to the TFR (CTFR. These measures are similar in construction to the marital (legitimate fertility rates and marital (legitimate TFR, but they are weighted by the proportion of women living alone, cohabiting, or being married at each age, so that their sum is the overall TFR. Taken together, they represent the fertility of the average woman of a synthetic cohort who moves across the various conjugal states (living alone, cohabiting, being married over her life course. They provide "realistic" estimates of completed fertility within each conjugal state. Conclusions: CASFRs provide a description of the fertility, over her life course, of a synthetic woman who would have spent her reproductive years living alone, cohabiting, and being married as the average woman of the synthetic cohort. CTFR provides a decomposition of the cumulative fertility of this synthetic woman. Over her life course, she would have had exactly the number of children computed using the overall TFR, but CTFR details the proportion of these children she would have had while living alone, while cohabiting, and while being married. Comments: Despite being defined as a conditional ASR weighted by the age-specific proportion of women living

  11. Business incubator as a support measure for start-ups in Russia and Sweden. : Comparative analysis.

    OpenAIRE

    Kiseleva, Maria

    2017-01-01

    Growth and developing of start-ups plays an important role as starting new business is one of the indicator that shows the economy level of each country. At that time start-ups need support and one of such support institutions is business incubator who can provide all resources that start-ups need. Different studies exist about business incubator as a support measure and the role of them for start- ups, but there is a lack of studies in analyzing this topic in different business environments....

  12. Combined gel filtration, biuret/copper method compared with an immunochemical method for urinary protein measurement.

    Science.gov (United States)

    Peele, J D; Gadsden, R H; Loadholt, C B

    1977-01-01

    We compared an immunochemical method specific for plasma proteins with a chemical method, in which interfering substances are separated by gel filtration and "total" urinary protein is determined by the biuret reaction followed by reaction of protein-bound copper with diethyldithiocarbamate after a second gel filtration to remove nonprotein-bound copper. More than 250 24-h urine samples were analyzed by each method. There was linear agreement and a correlation of 0.96 between the two methods, but urinary protein values determined by the immunochemical method, especially for patients with multiple myeloma, were lower than by the chemical method.

  13. Comparative Analysis of Different Measurement Techniques for MLC Characterization: Preliminary Results

    International Nuclear Information System (INIS)

    Larraga-Gutierrez, J. M.; Ballesteros-Zebadua, P.; Garcia-Garduno, O. A.; Martinez-Davalos, A.; Rodriguez-Villafuerte, M.; Moreno-Jimenez, S.; Celis, M. A.

    2008-01-01

    Radiation transmission, leakage and beam penumbra are essential dosimetric parameters related to the commissioning of a multileaf collimation system. This work shows a comparative analysis of commonly used film detectors: X-OMAT V2 and EDR2 radiographic films, and GafChromic EBT registered radiochromic film. The results show that X-OMAT over-estimates radiation leakage and 80-20% beam penumbra. However, according to the reference values reported by the manufacturer for these dosimetric parameters, all three films are adequate for MLC dosimetric characterization, but special care must be taken when X-OMAT V2 film is used due to its low energy photon dependence

  14. Comparing intermittency and network measurements of words and their dependence on authorship

    International Nuclear Information System (INIS)

    Amancio, Diego Raphael; Oliveira, Osvaldo N Jr; Fontoura Costa, Luciano da; Altmann, Eduardo G

    2011-01-01

    Many features of texts and languages can now be inferred from statistical analyses using concepts from complex networks and dynamical systems. In this paper, we quantify how topological properties of word co-occurrence networks and intermittency (or burstiness) in word distribution depend on the style of authors. Our database contains 40 books by eight authors who lived in the nineteenth and twentieth centuries, for which the following network measurements were obtained: the clustering coefficient, average shortest path lengths and betweenness. We found that the two factors with stronger dependence on authors were skewness in the distribution of word intermittency and the average shortest paths. Other factors such as betweenness and Zipf's law exponent show only weak dependence on authorship. Also assessed was the contribution from each measurement to authorship recognition using three machine learning methods. The best performance was about 65% accuracy upon combining complex networks and intermittency features with the nearest-neighbor algorithm of automatic authorship. From a detailed analysis of the interdependence of the various metrics, it is concluded that the methods used here are complementary for providing short- and long-scale perspectives on texts, which are useful for applications such as the identification of topical words and information retrieval. (paper)

  15. Eliciting mixed emotions: a meta-analysis comparing models, types, and measures

    Science.gov (United States)

    Berrios, Raul; Totterdell, Peter; Kellett, Stephen

    2015-01-01

    The idea that people can experience two oppositely valenced emotions has been controversial ever since early attempts to investigate the construct of mixed emotions. This meta-analysis examined the robustness with which mixed emotions have been elicited experimentally. A systematic literature search identified 63 experimental studies that instigated the experience of mixed emotions. Studies were distinguished according to the structure of the underlying affect model—dimensional or discrete—as well as according to the type of mixed emotions studied (e.g., happy-sad, fearful-happy, positive-negative). The meta-analysis using a random-effects model revealed a moderate to high effect size for the elicitation of mixed emotions (dIG+ = 0.77), which remained consistent regardless of the structure of the affect model, and across different types of mixed emotions. Several methodological and design moderators were tested. Studies using the minimum index (i.e., the minimum value between a pair of opposite valenced affects) resulted in smaller effect sizes, whereas subjective measures of mixed emotions increased the effect sizes. The presence of more women in the samples was also associated with larger effect sizes. The current study indicates that mixed emotions are a robust, measurable and non-artifactual experience. The results are discussed in terms of the implications for an affect system that has greater versatility and flexibility than previously thought. PMID:25926805

  16. Simulating SOFIA's image jitter performance and how the results compare to in-flight measurements

    Science.gov (United States)

    Graf, Friederike; Reinacher, Andreas; Spohr, Daniel; Jakob, Holger; Fasoulas, Stefanos

    2017-09-01

    SOFIA, the Stratospheric Observatory for Infrared Astronomy is an airborne telescope and in full operation since 2014. It has already successfully conducted over 400 flights and can be equipped with eight different science instruments which range from the visible to the far infrared wavelength regime. In order to reach SOFIA's scientific goals, the telescope has to provide a stable platform with the ambitous image jitter requirements of less than 0.4 "rms. Such a steady operating environment is especially important for slit spectrometers like EXES (Echelon - Cross - Echelle Spectrograph), that aim to keep the star in the area of a very thin slit for integration. Currently, image motion is mainly caused by deformation and excitation of the telescope structure in a wide range of frequencies. These disturbances are counteracted by the so-called Flexible Body Compensation system which uses a set of accelerometers to estimate the resulting image motion. To better study optimization possibilities of SOFIA's control system, a simulation tool has been developed which not only implements system identification data and analytically derived models, but also allows the implementation and verification with sensor data from in flight measurements. Results of the simulation as well as in flight measurements will be presented and improvement strategies will be discussed.

  17. Comparing traditional measures of academic success with emotional intelligence scores in nursing students.

    Science.gov (United States)

    Cheshire, Michelle H; Strickland, Haley P; Carter, Melondie R

    2015-01-01

    Emotional intelligence (EI) is the ability to perceive emotions, to access and generate emotions so as to assist thought, to understand emotions and emotional knowledge and to reflectively regulate emotions so as to promote emotional and intellectual growth. EI is increasingly discussed in healthcare as having a potential role in nursing. The purpose of this descriptive study was to examine the causal relationship between EI scores and the traditional academic admission criteria (GPA) and evaluation methods of a baccalaureate nursing program. The sample included second semester upper division nursing students ( n = 85). EI was measured using the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). The results of the statistical analysis (MANOVA, ANOVA and Pearson correlational coefficient) found no significant relationships or correlations with the current methods of evaluation for admission to nursing school or the evaluation methods used once students are in the nursing program. These results imply that assessing a nursing student's EI is measuring a different type of intelligence than that represented by academic achievement. Based on the findings of this study and the current state of nursing education, EI abilities should be included as part of the admission criteria for nursing programs.

  18. Biosecurity Measures Applied in the United Arab Emirates - a Comparative Study Between Livestock and Wildlife Sectors.

    Science.gov (United States)

    Chaber, A L; Saegerman, C

    2017-08-01

    In 2013, the livestock population in the UAE exceeded 4.3 million heads with sheep and goats accounting for 90% of this. The overall number of captive wild ungulates (gazelle types) is difficult to assess as there is no registration system in place or enforced in the UAE with regard to the possession of wildlife. Those animal collections, mainly owned by high-ranking families, are therefore not registered and kept far from public viewing. Nonetheless, some collections are housing more than 30 000 ungulates in one location. The primary objective of this study was to describe the biosecurity measures currently applied in UAE ungulate facilities for different wildlife and livestock sectors. A secondary objective was to use the output from this biosecurity survey to investigate which sector could be categorized into risk groups for disease introduction and spread. Between October 2014 and May 2015, biosecurity questionnaire data were collected in the Emirates of Abu Dhabi, Dubai, Ras Al Khaimah, Fujeirah, Ajman, Umm al Quwain and Sharjah from 14 wildlife collections, 30 livestock farms and 15 mixed (wildlife and livestock farms). These investigations through questionnaires allowed us to quantify and assess statistically biosecurity practices and levels for both livestock and wildlife sectors. In both sectors, biosecurity measures could be improved and only a few facilities had high biosecurity scores. The group of small unregistered farms (Ezba) represented the highest risk of disease transmission to other animals due to their lack of biosecurity awareness. © 2016 Blackwell Verlag GmbH.

  19. How physicians, patients and observers compare on the use of qualitative and quantitative measures of physician-patient communication

    Science.gov (United States)

    Gordon, Howard.S.; Street, Richard.L.

    2016-01-01

    The purpose of this study was to compare several different measures of physician-patient communication. We compared data derived from different measures of three communication behaviors: patient participation; physician information-giving; and physician participatory decision making (PDM) style, from 83 outpatient visits to oncology or thoracic surgery clinics for pulmonary nodules or lung cancer. Communication was measured with rating scales completed by patients and physicians after the consultation and by two different groups of external observers who used rating scales or coded the frequency of communication behaviors, respectively, after listening to an audio-recording of the consultation. Measures were compared using Pearson correlations. Correlations of patients’ and physicians’ ratings of patient participation (r=0.04) and physician PDM style (r=0.03) were low and not significant (P>0.0083 Bonferroni-adjusted). Correlations of observers’ ratings with patients’ or physicians’ ratings for patient participation and physician PDM style were moderate or low (r=0.15, 0.27, 0.07, and 0.01, respectively), but were not statistically significant (P>0.0083 Bonferroni-adjusted). Correlations between observers’ ratings and frequency measures were 0.31, 0.52, and 0.63, and were statistically significant with p-values 0.005, communication to more labor intensive frequency measures. PMID:26755527

  20. Laser ignition of aluminum nanoparticles in air

    Energy Technology Data Exchange (ETDEWEB)

    Sandstrom, M. M. (Mary M.); Oschwald, D. M. (David M); Son, S. F. (Steven F.)

    2004-01-01

    This paper reports on recent experiments of the ignition of nanoaluminum in air by CO{sub 2} laser heating. Ignition time and temperature were measured as a function of Al particle size and laser power. The ignition time was determined by high-speed digital images and frrst light as determined by a photodiode. The ignition delay increases with increasing particle size, and the decreasing laser power. Two stage burning is observed. The first reaction takes place on the surface of the powder sample and moves from the center to the edges followed by the second reaction, which takes place within the bulk of the sample. As the particles size increases the material is less likely to burn through out, leaving behind unreacted Al powder.

  1. Second coefficient of viscosity in air

    Science.gov (United States)

    Ash, Robert L.; Zuckerwar, Allan J.; Zheng, Zhonquan

    1991-01-01

    Acoustic attenuation measurements in air were analyzed in order to estimate the second coefficient of viscosity. Data over a temperature range of 11 C to 50 C and at relative humidities between 6 percent and 91 percent were used. This analysis showed that the second coefficient of viscosity varied between 1900 and 20,000 times larger than the dynamic or first coefficient of viscosity over the temperature and humidity range of the data. In addition, the data showed that the molecular relaxation effects, which are responsible for the magnitude of the second coefficient of viscosity, place severe limits on the use of time-independent, thermodynamic equations of state. Compressible flows containing large streamwise velocity gradients, like shock waves, which cause significant changes in particle properties to occur during time intervals shorter than hundredths of seconds, must be modeled using dynamic equations of state. The dynamic model approach is described briefly.

  2. Retention of fission products in air filters

    International Nuclear Information System (INIS)

    Sobnack, R.

    1986-01-01

    The plume from the Chernobyl nuclear reactor reached London in the morning of 1st May. Less than two weeks later, the Physics Department, University of Surrey, reported a measurable level of radioactivity in air filters. On 15th May air filters from within the air conditioning plant of the Radioisotope Department at the London Hospital were removed for radiation checks. Crude tests with a geiger counter gave readings of 5-10 times higher than background levels. Gamma-ray spectroscopy of the departmental air filters (AF1) using a 127 mm NaI detector revealed a pattern characteristic of emissions of fission products from a nuclear reactor. Another air filter (AF2), from the home of a member of staff, was much less active. Because of the complexity of the gamma-ray spectrum and the relatively high level of emission from the departmental air filter, a thorough investigation was carried out using a high purity germanium detector. (author)

  3. Comparative Study of Anthropometric Measurement and Body Composition between Elite Handball and Basketball Players

    Directory of Open Access Journals (Sweden)

    Aldijana Muratovic

    2014-09-01

    Full Text Available The purpose of this study was to describe anthropometric characteristics and body composition of elite handball and basketball players as well as to make comparisons between them. Fifty-nine males were enrolled in the study, divided into three groups: fifteen handball players, fourteen basketball players and thirty healthy sedentary subjects. The descriptive statistics were expressed as a mean (SD for each variable, while the ANOVA and LSD Post Hoc tests were carried out to detect the effects of each type of sport. The results showed there was no significant difference in body mass index among the groups, while a significant difference was found for body height and body weight as well as for all three of the body contents measured (muscle, bone and fat among the groups. These findings may give coaches from the region better working knowledge and suggest to them to follow recent selection process methods and to be more careful during the recruitment.

  4. Comparative study of measured and modelled number concentrations of nanoparticles in an urban street canyon

    DEFF Research Database (Denmark)

    Kumar, Prashant; Garmory, Andrew; Ketzel, Matthias

    2009-01-01

    Pollution Model (OSPM) and Computational Fluid Dynamics (CFD) code FLUENT. All models disregarded any particle dynamics. CFD simulations have been carried out in a simplified geometry of the selected street canyon. Four different sizes of emission sources have been used in the CFD simulations to assess...... simulations showed that selection of the source size was critical to determine PNC distributions. A source size scaling the vehicle dimensions was found to better represent the measured PNC profiles in the lowest part of the canyon. The OSPM and Box model produced similar shapes of PNC profile across...... differences were largest between idealised (CFD and Box) and operational (OSPM) models at upper sampling heights; these were attributed to weaker exchange of air between street and roof-above in the upper part of the canyon in the CFD calculations. Possible reasons for these discrepancies are given....

  5. Measuring working memory in aphasia: Comparing performance on complex span and N-back tasks

    Directory of Open Access Journals (Sweden)

    Maria Ivanova

    2014-04-01

    No significant correlations were observed between performance on complex span task and N-back tasks.Furthermore, performance on the modified listening span was related to performance on the comprehension subtest of the QASA, while no relationship was found for 2-back and 0-back tasks.Our results mirror studies in healthy controls that demonstrated no relationship between performance on the two tasks(Jaeggi et al., 2010; Kane et al., 2007. Thus although N-back tasks seem similar to traditional complex span measures and may also index abilities related to cognitive processing, the evidence to date does not warrant their direct association with the construct of WM. Implications for future investigation of cognitive deficits in aphasia will be discussed.

  6. Magnetic resonance image intensity ratio, a normalized measure to enable interpatient comparability of left atrial fibrosis.

    Science.gov (United States)

    Khurram, Irfan M; Beinart, Roy; Zipunnikov, Vadim; Dewire, Jane; Yarmohammadi, Hirad; Sasaki, Takeshi; Spragg, David D; Marine, Joseph E; Berger, Ronald D; Halperin, Henry R; Calkins, Hugh; Zimmerman, Stefan L; Nazarian, Saman

    2014-01-01

    The measurement of late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) intensity in arbitrary units limits the objectivity of thresholds for focal scar detection and interpatient comparisons of scar burden. To develop and validate a normalized measure, the image intensity ratio (IIR), for the assessment of left atrial (LA) scar on LGE-MRI. Electrocardiogram- and respiratory-gated 1.5 Tesla LGE-MRI was performed in 75 patients (75% men; 62 ± 8 years) before atrial fibrillation ablation. The local IIR was defined as LA myocardial signal intensity for each of the 20 sectors on contiguous axial image planes divided by the mean LA blood pool image intensity. Intracardiac point-by-point sampled electroanatomic map points were coregistered with the corresponding image sectors. The average bipolar voltage for all 8153 electroanatomic map points was 0.9 ± 1.1 mV. In a mixed effects model accounting for within patient clustering, and adjusting for age, LA volume, mass, body mass index, sex, CHA2DS2-VASc score, atrial fibrillation type, history of previous ablations, and contrast delay time, each unit increase in local IIR was associated with 91.3% decrease in bipolar LA voltage (P 0.97 and >1.61 corresponded to bipolar voltage <0.5 and <0.1 mV, respectively. Normalization of LGE-MRI intensity by the mean blood pool intensity results in a metric that is closely associated with intracardiac voltage as a surrogate of atrial fibrosis. © 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.

  7. Phonological performance measured by speech severity indices compared with correlated factors

    Directory of Open Access Journals (Sweden)

    Haydée Fiszbein Wertzner

    Full Text Available CONTEXT AND OBJECTIVE: Some factors seem to influence speech impairment among phonologically disordered children. The aim was to compare severity indices with some correlated factors. DESIGN AND SETTING: Observational, analytical and cross-sectional study conducted within the Language-Speech-Hearing Sciences Course, Universidade de São Paulo. METHOD: Fifty phonologically disordered children with ages ranging from 4 to 11 years took part. The indices were calculated from phonology tests and were correlated with anamnesis and audiological data. Student’s t test and Spearman’s correlation were used to compare percentages of consonants correct (PCC and process density index (PDI for children with and without otitis, upper respiratory histories and audiological abnormalities, with regard to whether or not they were comprehended during assessment, their ages when they started to speak and their ages at the assessment. RESULTS: The higher the age at the assessment was, the higher the PCC (imitation: 0.468; naming: 0.431; Spearman’s correlation and the lower the PDI (imitation: 0.459; naming: 0.431; the later the child started to speak, the lower the PCC (imitation p = 0.064; naming p = 0.050 and the higher the PDI (imitation p = 0.067; naming p = 0.042. There were differences between groups with and without upper respiratory history (PCC: imitation p = 0.016, naming p = 0.005; PDI: imitation p = 0.014, naming p = 0.008. There was no difference between the groups regarding otitis, comprehension during the assessment and audiological data. CONCLUSIONS: Children with upper respiratory histories who began to speak later presented more severe speech impairment indices.

  8. Comparative overview of dangers, protective measures and risks for the final disposal of radioactive wastes

    International Nuclear Information System (INIS)

    1981-10-01

    The purpose of this report is to present an overview of the anticipated risks of geological disposal of radioactive wastes and to compare these to 'conventional' risks, which voluntarily or involuntarily are associated with human activities and have accompanied mankind for long times. Radioactive wastes which result from the generation of electricity by commercial nuclear reactors as well as those originating from research, industrial and medical applications necessitate prolonged isolation from the biosphere to their long-lived, although decaying, toxicity. Chapter 2 of this report contains a survey of the nature and extent of the potential hazard of radioactive waste, drawing attention to the fact that the toxicity of radionuclides is comparable to that of nonradioactive chemical compounds. The possibility of adverse effects on the public cannot be ruled out for either kind of waste. Current plans aim at the safe and effective disposal of radioactive wastes in deep and stable geological formations which should serve as hosts for engineered final repositories. For a final repository to be suitable, the site chosen should be free from circulating groundwater or the free movement of the groundwater must be strongly restricted. In order to prevent radioactive substances migrating away from the final repository in which they have been placed, it is planned to utilise natural and man-made barriers which function largely independently from each other. Thorough knowledge of the properties of man-made barriers, is as important as knowledge of the natural barriers, which are determined by the geology and hydrogeology of the site of the final repository. This principle of protection is known as a 'multiple-barrier concept' and is considered capable of providing safe disposal of radioactive wastes

  9. Preliminary comparative assessment and elements of equivalence of air pollution measurement results of portable monitoring stations with using stochastic models

    Science.gov (United States)

    Owczarek, Tomasz; Rogulski, Mariusz; Badyda, Artur

    2018-01-01

    This article is an attempt to assess the suitability of new non-reference mobile measuring devices for the analysis of PM10 concentrations. The aim is to compare the concentration daily values measured by these devices with the concentrations obtained by the reference device. It also examines the possibility of building models that correct these values to equivalent reference values. The analysis allows to conclude that the properties of the obtained measurements indicate a good chance of constructing an effective model of correcting the concentration values. Comparison of frequency, time variation and correlation of concentrations indicates the ability to demonstrate the equivalence of mobile devices with the reference method.

  10. Standing Sound Waves in Air with DataStudio

    Science.gov (United States)

    Kraftmakher, Yaakov

    2010-01-01

    Two experiments related to standing sound waves in air are adapted for using the ScienceWorkshop data-acquisition system with the DataStudio software from PASCO scientific. First, the standing waves are created by reflection from a plane reflector. The distribution of the sound pressure along the standing wave is measured. Second, the resonance…

  11. A correction scheme for thermal conductivity measurement using the comparative cut-bar technique based on 3D numerical simulation

    International Nuclear Information System (INIS)

    Xing, Changhu; Folsom, Charles; Jensen, Colby; Ban, Heng; Marshall, Douglas W

    2014-01-01

    As an important factor affecting the accuracy of thermal conductivity measurement, systematic (bias) error in the guarded comparative axial heat flow (cut-bar) method was mostly neglected by previous researches. This bias is primarily due to the thermal conductivity mismatch between sample and meter bars (reference), which is common for a sample of unknown thermal conductivity. A correction scheme, based on finite element simulation of the measurement system, was proposed to reduce the magnitude of the overall measurement uncertainty. This scheme was experimentally validated by applying corrections on four types of sample measurements in which the specimen thermal conductivity is much smaller, slightly smaller, equal and much larger than that of the meter bar. As an alternative to the optimum guarding technique proposed before, the correction scheme can be used to minimize the uncertainty contribution from the measurement system with non-optimal guarding conditions. It is especially necessary for large thermal conductivity mismatches between sample and meter bars. (paper)

  12. Polycyclic aromatic hydrocarbons in air samples of meat smokehouses

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Olsen, I L; Poulsen, O M

    1992-01-01

    in smokehouses curing fish (Nordholm et al., 1986). In contrast to the study on PAH exposure in smokehouses curing fish, the present study revealed no significant difference between total PAH content in air samples collected above the kilns compared with samples collected approximately 2 m in front of the kiln...... exposure during hot fish curing....

  13. Smoking Cessation Benefit Utilization: Comparing Methodologies for Measurement using New York State's Medicaid Data.

    Science.gov (United States)

    Malloy, Kevin; Proj, Anisa; Battles, Haven; Juster, Theresa; Ortega-Peluso, Christina; Wu, Meng; Juster, Harlan

    2017-11-09

    Pharmacotherapy and counseling for tobacco cessation are evidence based methods that increase successful smoking cessation attempts. Medicaid programs are required to provide coverage for smoking cessation services. Monitoring utilization is desirable for program evaluation and quality improvement. Various methodologies have been used to study utilization. Many factors can influence results, perhaps none more than how smokers are identified. This study evaluated utilization of smoking cessation services using various methods to estimate the number of smokers within New York State's (NYS's) Medicaid program in 2015. Estimates of utilization were generated based on Medicaid claims and encounters and four sources of smoking prevalence: two population surveys, one Medicaid enrollee survey, and diagnosis codes. We compared the percentage of (estimated) smokers utilizing cessation services, and the average number of services used, across fee-for-service and managed care populations, and by cessation service category. Statewide, smoking prevalence estimates ranged from 10.9% to 31.5%. Diagnosis codes identified less than 45% of smokers estimated by surveys. A similar number of cessation counseling (199,106) and pharmacotherapy services (197,728) were used, yet more members utilized counseling (126,839) than pharmacotherapy (91,433). The estimated percentage of smokers who used smoking cessation services ranged from 15.1% to 43.4%, and the estimated average number of cessation services used ranged from 0.31 to 0.90 per smoker. Smoking prevalence estimates obtained through surveys greatly exceed prevalence observed in diagnosis codes in NYS's Medicaid data. Use of diagnosis codes in analysis of smoking cessation benefit utilization may result in overestimates. Selection of a smoking prevalence data source for similar analyses should ultimately be based on completeness of the data and applicability to the population of interest. Evaluation of smoking cessation benefit

  14. Comparative evaluation of three methods to measure working length - Manual tactile sensation, digital radiograph, and multidetector computed tomography: Anin vitrostudy.

    Science.gov (United States)

    Dutta, Kaushik; Desai, Priti D; Das, Utapal Kumar; Sarkar, Soumayabrata

    2017-01-01

    Compare the measurement of working length with three different methods manual tactile sensation, digital radiography and Mutidetector computed tomography(MDCT). 40 human premolar extracted for orthodontic purpose were selected. Teeth were store in sodium chloride (0.9%) during the study. Access cavity was prepared and canal patency was seen with no 10 file in each tooth. Manually no 15 K file was inserted from access cavity until the tip was visible at the foramen, a silicon stopper was adjusted to the corresponding buccal cusp tip and the root canal length was measured. After that in each tooth with no-15 K file inserted from access cavity with stop at tip of buccal cusp until tip appear at foramen and x-ray was taken with digital radiograph (RVG,Satelac) and canal length was measured. After that all teeth are mounted in wax block,MDCT scan was done and in the scan images of teeth, root canal length is measured from buccal cusp tip to root end. After taking measurement of working length with all three methods and the data was stastically analyzed with One Way Analysis of variance (ANOVA) followed by Turkey's Test. ANOVA and turkeys test showed that there was no significant difference in the measurements by the three procedures (p>0.05). Working length measurement with MDCT scan and other two conventional methods does not show significant difference in measurement. Use of newer 3D imaging technique is useful in root canal treatment for measuring working length.

  15. Comparing parameterized versus measured microphysical properties of tropical convective cloud bases during the ACRIDICON-CHUVA campaign

    Science.gov (United States)

    Campos Braga, Ramon; Rosenfeld, Daniel; Weigel, Ralf; Jurkat, Tina; Andreae, Meinrat O.; Wendisch, Manfred; Pöhlker, Mira L.; Klimach, Thomas; Pöschl, Ulrich; Pöhlker, Christopher; Voigt, Christiane; Mahnke, Christoph; Borrmann, Stephan; Albrecht, Rachel I.; Molleker, Sergej; Vila, Daniel A.; Machado, Luiz A. T.; Artaxo, Paulo

    2017-06-01

    The objective of this study is to validate parameterizations that were recently developed for satellite retrievals of cloud condensation nuclei supersaturation spectra, NCCN(S), at cloud base alongside more traditional parameterizations connecting NCCN(S) with cloud base updrafts and drop concentrations. This was based on the HALO aircraft measurements during the ACRIDICON-CHUVA campaign over the Amazon region, which took place in September 2014. The properties of convective clouds were measured with a cloud combination probe (CCP), a cloud and aerosol spectrometer (CAS-DPOL), and a CCN counter onboard the HALO aircraft. An intercomparison of the cloud drop size distributions (DSDs) and the cloud water content (CWC) derived from the different instruments generally shows good agreement within the instrumental uncertainties. To this end, the directly measured cloud drop concentrations (Nd) near cloud base were compared with inferred values based on the measured cloud base updraft velocity (Wb) and NCCN(S) spectra. The measurements of Nd at cloud base were also compared with drop concentrations (Na) derived on the basis of an adiabatic assumption and obtained from the vertical evolution of cloud drop effective radius (re) above cloud base. The measurements of NCCN(S) and Wb reproduced the observed Nd within the measurements uncertainties when the old (1959) Twomey's parameterization was used. The agreement between the measured and calculated Nd was only within a factor of 2 with attempts to use cloud base S, as obtained from the measured Wb, Nd, and NCCN(S). This underscores the yet unresolved challenge of aircraft measurements of S in clouds. Importantly, the vertical evolution of re with height reproduced the observation-based nearly adiabatic cloud base drop concentrations, Na. The combination of these results provides aircraft observational support for the various components of the satellite-retrieved methodology that was recently developed to retrieve NCCN

  16. Modulation of Galactic Cosmic Rays in the Inner Heliosphere, Comparing with PAMELA Measurements

    Science.gov (United States)

    Qin, G.; Shen, Z.-N.

    2017-09-01

    We develop a numerical model to study the time-dependent modulation of galactic cosmic rays in the inner heliosphere. In the model, a time-delayed modified Parker heliospheric magnetic field (HMF) and a new diffusion coefficient model, NLGCE-F, from Qin & Zhang, are adopted. In addition, the latitudinal dependence of magnetic turbulence magnitude is assumed to be ˜ (1+{\\sin }2θ )/2 from the observations of Ulysses, and the radial dependence is assumed to be ˜ {r}S, where we choose an expression of S as a function of the heliospheric current sheet tilt angle. We show that the analytical expression used to describe the spatial variation of HMF turbulence magnitude agrees well with the Ulysses, Voyager 1, and Voyager 2 observations. By numerically calculating the modulation code, we get the proton energy spectra as a function of time during the recent solar minimum, it is shown that the modulation results are consistent with the Payload for Antimatter-Matter Exploration and Light-nuclei Astrophysics measurements.

  17. Measuring HRQoL by comparing the perception of air quality among residents in Selangor

    Science.gov (United States)

    Mohammad, Nor Hazlina; Abdullah, Mohammad Nasir; Razi, Nor Faezah Mohd; Ismail, Adriana

    2017-05-01

    Most studies regarding to air pollution were focused on forecasting Air Pollutant Index (API). Yet, there were no studies that conducted in Malaysia focused on Health-Related Quality of Life (HRQoL). The aim of this study was to investigate the HRQoL in two urban cities, which are Shah Alam and Putrajaya with different air pollution index. In doing so, SF36v2 questionnaire has been utilized to elicit data on HRQoL domains measured using eight domains (Physical Functioning, Role-Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role-Emotional and Mental Health). A cross-sectional study was conducted and residents were selected using simple random sampling from Shah Alam and Putrajaya. The SF36v2 questionnaire with socio demographic information was distributed to the residents. A total of 266 participated in the study, of which 133 samples per groups. The statistical methods employed were descriptive analyses, independent samples t-test and MANOVA to analyze the HRQoL data. There was no difference in perceptions on HRQoL for Role Physical, Vitality, Social Functioning and Mental Health between residents in Shah Alam and residents in Putrajaya. However, there was difference in perception on HRQoL for Physical Functioning, Bodily Pain, General Health and Role Emotional.

  18. Justice involvement among homeless individuals with mental illnesses: Are self-report and administrative measures comparable?

    Science.gov (United States)

    Lemieux, Ashley J; Roy, Laurence; Martin, Michael S; Latimer, Eric A; Crocker, Anne G

    2017-04-01

    Individuals with mental illnesses who experience homelessness have frequent interactions with the criminal justice system. Correctly measuring this involvement is essential to develop and evaluate the efficacy of intervention programs. Criminal justice involvement is typically assessed through administrative records or self-reported accounts. The aims of this study are to: 1) assess agreement between self-report and administrative data related to court appearances, and 2) identify individual characteristics that affect discrepancies between sources. Participants were 468 homeless persons with mental illness from the Montreal site of the At Home/Chez Soi randomized controlled trial, in Canada. Self-reported data was collected through an interviewer-administered questionnaire. Administrative data was collected through provincial and municipal court databases. Overall, agreement was good. Discrepancies were more common among those with a diagnosis of mood disorder with psychotic features, and those with a criminal history. Increased age and interviewer's perception of sincerity and interest increased likelihood of concordance. Generally, high agreement between self-report and administrative data suggests that either source can provide reliable information. Further work to understand predictors of discrepancies could further enhance the quality of data collected through these different sources. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. MEASURING ORGANIZATIONAL CULTURE: A QUANTITATIVE-COMPARATIVE ANALYSIS [doi: 10.5329/RECADM.20100902007

    Directory of Open Access Journals (Sweden)

    Valderí de Castro Alcântara

    2010-11-01

    Full Text Available This article aims at the analysis of the organizational culture at enterprises located in two towns with distinct quantitative traits, Rio Paranaíba and Araxá. While the surveyed enterprises in Rio Paranaíba are mostly micro and small enterprises (86%, in Araxá there are mostly medium and large companies (53%. The overall objective is to verify if there are significant differences in organizational culture among these enterprises and if they can be explained by the organization size. The research was quantitative and instruments for data collection were a questionnaire and a scale for measuring organizational culture containing four dimensions: Hierarchical Distance Index (IDH, Individualism Index (INDI, Masculinity Index (MASC and the Uncertainty Control Index (CINC. Tabulation and analysis of data were performed using the PASW Statistics 18, doing descriptive and inferential statistical procedures. Using a Reduction Factor (-21 the achieved indexes were classified into 5 intensity categories (from "very low" to "very high". The Student t test for two means was performed, revealing significant differences in Hierarchical Distance and Individualism between Araxá and Rio Paranaíba enterprises (p <0.05.   Keywords Organizational Culture; Dimensions of Organizational Culture; Araxá; Rio Paranaíba.

  20. Ranking DMUs by Comparing DEA Cross-Efficiency Intervals Using Entropy Measures

    Directory of Open Access Journals (Sweden)

    Tim Lu

    2016-12-01

    Full Text Available Cross-efficiency evaluation, an extension of data envelopment analysis (DEA, can eliminate unrealistic weighing schemes and provide a ranking for decision making units (DMUs. In the literature, the determination of input and output weights uniquely receives more attentions. However, the problem of choosing the aggressive (minimal or benevolent (maximal formulation for decision-making might still remain. In this paper, we develop a procedure to perform cross-efficiency evaluation without the need to make any specific choice of DEA weights. The proposed procedure takes into account the aggressive and benevolent formulations at the same time, and the choice of DEA weights can then be avoided. Consequently, a number of cross-efficiency intervals is obtained for each DMU. The entropy, which is based on information theory, is an effective tool to measure the uncertainty. We then utilize the entropy to construct a numerical index for DMUs with cross-efficiency intervals. A mathematical program is proposed to find the optimal entropy values of DMUs for comparison. With the derived entropy value, we can rank DMUs accordingly. Two examples are illustrated to show the effectiveness of the idea proposed in this paper.

  1. A Comparative Analysis of Value at Risk Measurement on Emerging Stock Markets: Case of Montenegro

    Directory of Open Access Journals (Sweden)

    Cerović Julija

    2015-03-01

    Full Text Available Background: The concept of value at risk gives estimation of the maximum loss of financial position at a given time for a given probability. The motivation for this analysis lies in the desire to devote necessary attention to risks in Montenegro, and to approach to quantifying and managing risk more thoroughly. Objectives: This paper considers adequacy of the most recent approaches for quantifying market risk, especially of methods that are in the basis of extreme value theory, in Montenegrin emerging market before and during the global financial crisis. In particular, the purpose of the paper is to investigate whether extreme value theory outperforms econometric and quantile evaluation of VaR in emerging stock markets such as Montenegrin market. Methods/Approach: Daily return of Montenegrin stock market index MONEX20 is analyzed for the period January, 2004 - February, 2014. Value at Risk results based on GARCH models, quantile estimation and extreme value theory are compared. Results: Results of the empirical analysis show that the assessments of Value at Risk based on extreme value theory outperform econometric and quantile evaluations. Conclusions: It is obvious that econometric evaluations (ARMA(2,0- GARCH(1,1 and RiskMetrics proved to be on the lower bound of possible Value at Risk movements. Risk estimation on emerging markets can be focused on methodology using extreme value theory that is more sophisticated as it has been proven to be the most cautious model when dealing with turbulent times and financial turmoil.

  2. Comparative evaluation of three impactor samplers for measuring airborne bacteria and fungi concentrations.

    Science.gov (United States)

    Méheust, Delphine; Gangneux, Jean-Pierre; Cann, Pierre Le

    2013-01-01

    Portable microbial samplers are useful for detecting microorganisms in the air. However, limited data are available on their performance when sampling airborne biological agents in a routine practice. We compared bacterial and fungal concentrations obtained in field conditions using three impactor samplers with different designs (AES Chemunex Sampl'Air, bioMérieux Air Ideal, and Sartorius AirPort MD8/BACTair). The linearity of mold collection was tested in the range of 100 L to 1000 L, and all the devices had a correlation coefficient higher than 0.95. For optimal comparison of the samplers, we performed experiments in different hospital rooms with varying levels of air biocontamination. Each sampling procedure was repeated to assess reproducibility. No significant difference between the samplers was observed for the mold concentrations on Sabouraud agar, whereas Sampl'Air collected significantly more bacteria on tryptic soy agar than Air Ideal or BACTair at one of the sites. Impactor location in the room was nevertheless associated with the variability observed with the three samplers at the highest microbial concentration levels. On the basis of their performance, autonomy and simplicity of use, these three impactors are suitable for routine indoor evaluation of microbial air contamination.

  3. Comparative Genomics of Interreplichore Translocations in Bacteria: A Measure of Chromosome Topology?

    Science.gov (United States)

    Khedkar, Supriya; Seshasayee, Aswin Sai Narain

    2016-06-01

    Genomes evolve not only in base sequence but also in terms of their architecture, defined by gene organization and chromosome topology. Whereas genome sequence data inform us about the changes in base sequences for a large variety of organisms, the study of chromosome topology is restricted to a few model organisms studied using microscopy and chromosome conformation capture techniques. Here, we exploit whole genome sequence data to study the link between gene organization and chromosome topology in bacteria. Using comparative genomics across ∼250 pairs of closely related bacteria we show that: (a) many organisms show a high degree of interreplichore translocations throughout the chromosome and not limited to the inversion-prone terminus (ter) or the origin of replication (oriC); (b) translocation maps may reflect chromosome topologies; and (c) symmetric interreplichore translocations do not disrupt the distance of a gene from oriC or affect gene expression states or strand biases in gene densities. In summary, we suggest that translocation maps might be a first line in defining a gross chromosome topology given a pair of closely related genome sequences. Copyright © 2016 Khedkar and Seshasayee.

  4. Measuring Disability: Comparing the Impact of Two Data Collection Approaches on Disability Rates

    Science.gov (United States)

    Sabariego, Carla; Oberhauser, Cornelia; Posarac, Aleksandra; Bickenbach, Jerome; Kostanjsek, Nenad; Chatterji, Somnath; Officer, Alana; Coenen, Michaela; Chhan, Lay; Cieza, Alarcos

    2015-01-01

    The usual approach in disability surveys is to screen persons with disability upfront and then ask questions about everyday problems. The objectives of this paper are to demonstrate the impact of screeners on disability rates, to challenge the usual exclusion of persons with mild and moderate disability from disability surveys and to demonstrate the advantage of using an a posteriori cut-off. Using data of a pilot study of the WHO Model Disability Survey (MDS) in Cambodia and the polytomous Rasch model, metric scales of disability were built. The conventional screener approach based on the short disability module of the Washington City Group and the a posteriori cut-off method described in the World Disability Report were compared regarding disability rates. The screener led to imprecise rates and classified persons with mild to moderate disability as non-disabled, although these respondents already experienced important problems in daily life. The a posteriori cut-off applied to the general population sample led to a more precise disability rate and allowed for a differentiation of the performance and needs of persons with mild, moderate and severe disability. This approach can be therefore considered as an inclusive approach suitable to monitor the Convention on the Rights of Persons with Disabilities. PMID:26308039

  5. Measuring Disability: Comparing the Impact of Two Data Collection Approaches on Disability Rates

    Directory of Open Access Journals (Sweden)

    Carla Sabariego

    2015-08-01

    Full Text Available The usual approach in disability surveys is to screen persons with disability upfront and then ask questions about everyday problems. The objectives of this paper are to demonstrate the impact of screeners on disability rates, to challenge the usual exclusion of persons with mild and moderate disability from disability surveys and to demonstrate the advantage of using an a posteriori cut-off. Using data of a pilot study of the WHO Model Disability Survey (MDS in Cambodia and the polytomous Rasch model, metric scales of disability were built. The conventional screener approach based on the short disability module of the Washington City Group and the a posteriori cut-off method described in the World Disability Report were compared regarding disability rates. The screener led to imprecise rates and classified persons with mild to moderate disability as non-disabled, although these respondents already experienced important problems in daily life. The a posteriori cut-off applied to the general population sample led to a more precise disability rate and allowed for a differentiation of the performance and needs of persons with mild, moderate and severe disability. This approach can be therefore considered as an inclusive approach suitable to monitor the Convention on the Rights of Persons with Disabilities.

  6. Comparing Small Area Techniques for Estimating Poverty Measures: the Case Study of Austria and Spain

    Directory of Open Access Journals (Sweden)

    Federico Crescenzi

    2016-06-01

    Full Text Available The Europe 2020 Strategy has formulated key policy objectives or so-called “headline targets” which the European Union as a whole and Member States are individually committed to achieving by 2020. One of the five headline targets is directly related to the key quality aspects of life, namely social inclusion; within these targets, the European Union Statistics on Income and Living Condition (EU-SILC headline indicators atrisk-of-poverty or social exclusion and its components will be included in the budgeting of structural funds, one of the main instruments through which policy targets are attained. For this purpose, Directorate-General Regional Policy of the European Commission is aiming to use sub-national/regional level data (NUTS 2. Starting from this, the focus of the present paper is on the “regional dimension” of well-being. We propose to adopt a methodology based on the Empirical Best Linear Unbiased Predictor (EBLUP with an extension to the spatial dimension (SEBLUP; moreover, we compare this small area technique with the cumulation method. The application is conducted on the basis of EU-SILC data from Austria and Spain. Results report that, in general, estimates computed with the cumulation method show standard errors which are smaller than those computed with EBLUP or SEBLUP. The gain of pooling SILC data over three years is, therefore, relevant, and may allow researchers to prefer this method.

  7. Comparative measurement of inorganic elements in Korean space foods using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong Sam; Kim, Sun Ha; Baek, Sung Ryel; Sun, Gwang Min; Moon, Jong Hwa; Choi, Jong Il; Lee, Joo Eun [KAERI, Daejeon (Korea, Republic of)

    2012-10-15

    In April 2008, Korea's first astronaut became a crew member of the international space station and she brought special space versions of traditional Korean dishes such as kimchi, boiled rice, hot red pepper paste, soybean paste soup, ginseng tea, green tea, and ramyun. To date, seventy kinds of Korean space foods (KSFs) have been developed by KAERI. The information and role of trace mineral elements from an intake of created and processed foodstuff are important as a indicator of human health and nutrition, as well as a quality control of food and diet. In particular, special food created for consumption by astronauts in outer space may differ with common food on the earth to compensate a decrease in taste and nutrition by hygienic sterilization processing as well as strong cosmic rays, a state of non gravitation, low pressure, and an enclosed space environment. An accurate quantitative analysis of trace elements in various kinds of biological samples is serious work for analytical data quality. An neutron activation analysis is a sensitive, non destructive, multi elemental analytical method without loss and contamination of a sample by chemical pre treatment. The aim of this study is to identify and to compare the distribution of concentrations for essential and functional inorganic elements in six kinds of Korean space foods developed by KAERI in 2011 using INAA.

  8. Comparative measurement of inorganic elements in Korean space foods using instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Chung, Yong Sam; Kim, Sun Ha; Baek, Sung Ryel; Sun, Gwang Min; Moon, Jong Hwa; Choi, Jong Il; Lee, Joo Eun

    2012-01-01

    In April 2008, Korea's first astronaut became a crew member of the international space station and she brought special space versions of traditional Korean dishes such as kimchi, boiled rice, hot red pepper paste, soybean paste soup, ginseng tea, green tea, and ramyun. To date, seventy kinds of Korean space foods (KSFs) have been developed by KAERI. The information and role of trace mineral elements from an intake of created and processed foodstuff are important as a indicator of human health and nutrition, as well as a quality control of food and diet. In particular, special food created for consumption by astronauts in outer space may differ with common food on the earth to compensate a decrease in taste and nutrition by hygienic sterilization processing as well as strong cosmic rays, a state of non gravitation, low pressure, and an enclosed space environment. An accurate quantitative analysis of trace elements in various kinds of biological samples is serious work for analytical data quality. An neutron activation analysis is a sensitive, non destructive, multi elemental analytical method without loss and contamination of a sample by chemical pre treatment. The aim of this study is to identify and to compare the distribution of concentrations for essential and functional inorganic elements in six kinds of Korean space foods developed by KAERI in 2011 using INAA

  9. Measurement Matters: Comparing Old and New Definitions of Rape in Federal Statistical Reporting.

    Science.gov (United States)

    Bierie, David M; Davis-Siegel, James C

    2015-10-01

    National statistics on the incidence of rape play an important role in the work of policymakers and academics. The Uniform Crime Reports (UCR) have provided some of the most widely used and influential statistics on the incidence of rape across the United States over the past 80 years. The definition of rape used by UCR changed in 2012 to include substantially more types of sexual assault. This article draws on 20 years of data from the National Incident-Based Reporting System to describe the impact this definitional change will have on estimates of the incidence of rape and trends over time. Drawing on time series as well as panel random effects methodologies, we show that 40% of sexual assaults have been excluded by the prior definition and that the magnitude of this error has grown over time. However, the overall trend in rape over time (year-to-year change) was not substantially different when comparing events meeting the prior definition and the subgroups of sexual assault that will now be counted. © The Author(s) 2014.

  10. Measuring empathy of medical students studying different curricula; a causal comparative study.

    Science.gov (United States)

    Ayub, Ayesha; Khan, Rehan Ahmed

    2017-08-01

    To determine the difference in empathy level of undergraduate medical students studying two different curricula. This cross-sectional study was conducted at Independent Medical College of Faisalabad and Islamic International Medical Collegeof Islamabad, both in Pakistan, from July to September 2016. The two medical colleges had two different types of curriculum systems; the integrated modular system and the discipline-based curriculum. The Toronto empathy questionnaire was used to calculate empathy scores. The responses were scored between 0 and 64 by taking sum of all the 16 questions. T-test was used to compare the mean scores and empathy levels between the two groups. SPSS 20 was used for data analysis. Of the 160 students, there were 80(50%) belonging to each institute. In the integrated modular system, 44(55%) students were females, whereas in the discipline-based system 45(56%) students were males. Students enrolled in the integrated modular system had a higher mean empathy score than students in the discipline-based system (44.2±6.59 versus 39.7±6.54, pstudents' personalities and their future practices.

  11. Smartphone and Universal Goniometer for Measurement of Elbow Joint Motions: A Comparative Study.

    Science.gov (United States)

    Behnoush, Behnam; Tavakoli, Nasim; Bazmi, Elham; Nateghi Fard, Fariborz; Pourgharib Shahi, Mohammad Hossein; Okazi, Arash; Mokhtari, Tahmineh

    2016-06-01

    Universal goniometer (UG) is commonly used as a standard method to evaluate range of motion (ROM) as part of joint motions. It has some restrictions, such as involvement of both hands of the physician, leads to instability of hands and error. Nowadays smartphones usage has been increasing due to its easy application. The study was designed to compare the smartphone inclinometer-based app and UG in evaluation of ROM of elbow. The maximum ROM of elbow in position of flexion and pronation and supination of forearm were examined in 60 healthy volunteers with UG and smartphone. Data were analyzed using SPSS (ver. 16) software and appropriate statistical tests were applied, such as paired t-test, ICC and Bland Altman curves. The results of this study showed high reliability and validity of smartphone in regarding UG with ICC > 0.95. The highest reliability for both methods was in elbow supination and the lowest was in the elbow flexion (0.84). Smartphones due to ease of access and usage for the physician and the patient, may be good alternatives for UG.

  12. Towards an Engaged Campus: Measuring and Comparing Definitive Stakeholders' Perceptions of University Social Engagement in South Korea

    Science.gov (United States)

    Cho, Young Ha

    2017-01-01

    Purpose: This paper aims to measure and rigorously compare the perceptions of South Korean university social engagement between faculty and students, two definitive stakeholders identified by stakeholder theory--but considerably heterogeneous, to understand how South Korean campus embraces social engagement in practice. To that end, this study…

  13. Develop generic equations to determine radon daughters concentrations in air

    International Nuclear Information System (INIS)

    Shweikani, R.; Jerby, B.

    2011-06-01

    Measurements of radon daughter concentrations in air are very important to determine the human dose from background radiation. Therefore, many studies tried to find measurements methods depending on many specific parameters such as measurement time, air pumping period and sample volume. In this study a general equations to determine radon daughter's concentrations in air was found using direct samples. The Equations results were closed to the results obtained from other well known methods. Many measurements with different places and various conditions were performed; the results showed that the new equations are able to be used with an error less than 10%, The relative error can be reduced by increasing the pumping rate or measuring high concentration cases.(author)

  14. Transcutaneous oximetry compared to ankle-brachial-index measurement in the evaluation of percutaneous transluminal angioplasty

    International Nuclear Information System (INIS)

    Wildgruber, Moritz; Wolf, Oliver; Weiss, Wolfgang; Berger, Hermann; Lutzenberger, Werner; Eckstein, Hans-Henning; Heider, Peter

    2007-01-01

    Objective: To investigate transcutaneous oximetry as parameter of the microcirculation is correlated to ankle-brachial-index as parameter of the macrocirculation after peripheral angioplasty procedures. Design: Prospective study. Materials and methods: 60 patients suffering from intermittent claudication were scheduled for angioplasty treatment. 45 patients were considered as eligible for angioplasty after angiographic evaluation, 15 patients underwent angiography only. Transcutaneous oximetry measurements were performed before the procedure, at the end of intervention, 24 h as well as 2 and 4 weeks after percutaneous transluminal angioplasty. Ankle-brachial-indices were obtained before intervention, 24 h as well as 2 and 4 weeks later. Results: Ankle-brachial-indices increased significantly at 24 h after angioplasty in patients being treated with angioplasty. Transcutaneous oximetry values dropped significantly at the end of the procedure and returned close to the baseline levels at 2 and 4 weeks after angioplasty. Ankle-brachial-indices and transcutaneous oximetry were positively correlated before (r = 0.3833, p = 0.009) as well as 4 weeks after angioplasty (r = 0.4596, p = 0.001). Immediately after radiological interventions, ankle-brachial-indices and transcutaneous oximetry are not positively correlated. In patients undergoing angiography only, transcutaneous oximetry levels drop significantly immediately after angiography and remain at decreased levels even at 4 weeks after intervention. Conclusion: Transcutaneous oximetry as parameter of the microcirculation is positively correlated with ankle-brachial-index as parameter of the macrocirculation before and at 4 weeks after angioplasty. Intraarterial angiography leads to a sudden decrease in skin microcirculation without affecting macrocirculation. As indicated by a lack of recovery in transcutaneous oximetry levels after 4 weeks, angiography alone results in a prolonged impaired microcirculation which may

  15. The aerodynamic cost of flight in the short-tailed fruit bat (Carollia perspicillata): comparing theory with measurement.

    Science.gov (United States)

    von Busse, Rhea; Waldman, Rye M; Swartz, Sharon M; Voigt, Christian C; Breuer, Kenneth S

    2014-06-06

    Aerodynamic theory has long been used to predict the power required for animal flight, but widely used models contain many simplifications. It has been difficult to ascertain how closely biological reality matches model predictions, largely because of the technical challenges of accurately measuring the power expended when an animal flies. We designed a study to measure flight speed-dependent aerodynamic power directly from the kinetic energy contained in the wake of bats flying in a wind tunnel. We compared these measurements with two theoretical predictions that have been used for several decades in diverse fields of vertebrate biology and to metabolic measurements from a previous study using the same individuals. A high-accuracy displaced laser sheet stereo particle image velocimetry experimental design measured the wake velocities in the Trefftz plane behind four bats flying over a range of speeds (3-7 m s(-1)). We computed the aerodynamic power contained in the wake using a novel interpolation method and compared these results with the power predicted by Pennycuick's and Rayner's models. The measured aerodynamic power falls between the two theoretical predictions, demonstrating that the models effectively predict the appropriate range of flight power, but the models do not accurately predict minimum power or maximum range speeds. Mechanical efficiency--the ratio of aerodynamic power output to metabolic power input--varied from 5.9% to 9.8% for the same individuals, changing with flight speed.

  16. Is There a Method That Can Measure Cohesivity? Cohesion by Sensory Evaluation Compared With Other Test Methods.

    Science.gov (United States)

    Edsman, Katarina L M; Wiebensjö, Åsa M; Risberg, Anna Maria; Öhrlund, Jan Åke

    2015-12-01

    Cohesion is described as the force between particles of the same substance that acts to unite them. Contrary to rheology, there are currently no ready-made instruments designed to measure cohesion, or methods which could be easily adapted to gels. To study and compare the possible clinical effects from the cohesive properties of a gel, it is necessary to standardize the definition and measurement of cohesion. The purpose of this study was to develop and evaluate methods for measuring cohesion. Three different methods were evaluated and compared with measures of perceived cohesion; compression force, dispersion in water and drop weight. Two different families of fillers (Emervel and Restylane) were used for evaluating the different methods. The compression force did not reflect the measures of perceived cohesion. The dispersion method showed variable results over time, had some practical issues, and is evaluated by subjective assessment. The best correlation to the perceived cohesion was found with the drop weight method. The drop weight method which closely resembles the definition of cohesion (IUPAC) was considered to be the best method for measuring cohesion.

  17. Short Communication: Testosterone Measured with an Automatic Immunoassay Compares Reasonbly Well to Results Obtained by LC-MS/MS

    DEFF Research Database (Denmark)

    Knudsen, Cindy Søndersø; Højskov, Carsten Schriver; Møller, Holger Jon

    2016-01-01

    Background: Previous studies have reported problems measuring testosterone with immunological assays. Here we explore an automatic second generation immunoassay compared to a LC-MS/MS method. Methods: We collected blood samples from 76 women and measured testosterone, progesterone, gender...... hormonebinding globulin (SHBG), and albumin employing Cobas e601/c501. Testosterone, androstenedione (andro), dehydroepiandrosterone sulphate (DHEAS), and 17-hydroxyprogesterone (17-OHP) concentrations were measured employing LC-MS/MS. We evaluated the difference between testosterone measured by the two methods...... for the difference between results obtained by the two methods and the sample concentration of DHEAS and andro: Diff (Cobas e601 - LC-MS/MS) = 0.116 x DHEAS - 0.396, r = 0.84 and Diff (Cobas e601 - LC-MS/MS) = 0.08 andro - 0.380, r = 0.58. No statistically significant interference was observed for progesterone, 17...

  18. Comparative Study of foF2 Measurements with IRI-2007 Model Predictions During Extended Solar Minimum

    Science.gov (United States)

    Zakharenkova, I. E.; Krankowski, A.; Bilitza, D.; Cherniak, Iu.V.; Shagimuratov, I.I.; Sieradzki, R.

    2013-01-01

    The unusually deep and extended solar minimum of cycle 2324 made it very difficult to predict the solar indices 1 or 2 years into the future. Most of the predictions were proven wrong by the actual observed indices. IRI gets its solar, magnetic, and ionospheric indices from an indices file that is updated twice a year. In recent years, due to the unusual solar minimum, predictions had to be corrected downward with every new indices update. In this paper we analyse how much the uncertainties in the predictability of solar activity indices affect the IRI outcome and how the IRI values calculated with predicted and observed indices compared to the actual measurements.Monthly median values of F2 layer critical frequency (foF2) derived from the ionosonde measurements at the mid-latitude ionospheric station Juliusruh were compared with the International Reference Ionosphere (IRI-2007) model predictions. The analysis found that IRIprovides reliable results that compare well with actual measurements, when the definite (observed and adjusted) indices of solar activityare used, while IRI values based on earlier predictions of these indices noticeably overestimated the measurements during the solar minimum.One of the principal objectives of this paper is to direct attention of IRI users to update their solar activity indices files regularly.Use of an older index file can lead to serious IRI overestimations of F-region electron density during the recent extended solar minimum.

  19. Self-report measures best explain changes in disability compared with physical measures after exercise rehabilitation for chronic low back pain.

    Science.gov (United States)

    Marshall, Paul; Murphy, Bernadette

    2008-02-01

    Sixteen-week intervention for chronic patients with low back pain (LBP) with 9-month follow-up. Primary randomization at 4 weeks into either supervised Swiss ball exercise or an exercise advice group. To evaluate changes in disability and pain in individuals with chronic LBP after combined treatment and exercise interventions, and to evaluate whether changes in self-report or physical measures would best explain improvements in disability There is a need to understand what the effectiveness of a clinically applicable treatment intervention is for an individual's perception of their back pain. There is insufficient evidence about the different combinations of manual treatment that commonly precede involvement in exercise programs. Sixty individuals with chronic nonspecific LBP (at least 3-month duration) were randomly assigned (after 4 weeks of manipulative or nonmanipulative treatment) to either a supervised Swiss ball exercise group, or an advice group. The exercise intervention was for 12 weeks with a long-term follow-up of 9 months. Self-report measures and physical measures (endurance times and myoelectric fatigue) were collected throughout the study. Self-rated disability improved more after the treatment period for individuals who received supervised exercise compared with advice alone. There was no difference found between individuals who received manipulative or nonmanipulative treatment. Multiple regression analysis found that self-report measures best explained improvements in disability throughout the study. Long-term findings showed no group differences. Supervised exercise is a more successful subsequent to manual treatment compared with exercise advice. The improvements associated with this type of program were primarily manifested in the psychologic self-report measures rather than physical measurements.

  20. Laser transit anemometer and Pitot probe comparative measurements in a sharp cone boundary layer at Mach 4

    Science.gov (United States)

    Hunter, W. W., Jr.; Ocheltree, S. L.; Russ, C. E., Jr.

    1991-01-01

    Laser transit anemometer (LTA) measurements of a 7 degree sharp cone boundary layer were conducted in the Air Force/AEDC Supersonic Tunnel A Mach 4 flow field. These measurements are compared with Pitot probe measurements and tricone theory provided by AEDC staff. Measurements were made both in laminar and turbulent boundary layers of the model. Comparison of LTA measurements with theory showed agreement to better than 1 percent for the laminar boundary layer cases. This level of agreement was obtained after small position corrections, 0.01 to 0.6 mm, were applied to the experimental data sets. Pitot probe data when compared with theory also showed small positioning errors. The Pitot data value was also limited due to probe interference with the flow near the model. The LTA turbulent boundary layer data indicated a power law dependence of 6.3 to 6.9. The LTA data was analyzed in the time (Tau) domain in which it was obtained and in the velocity domain. No significant differences were noted between Tau and velocity domain results except in one turbulent boundary layer case.

  1. Body composition in sport: a comparison of a novel ultrasound imaging technique to measure subcutaneous fat tissue compared with skinfold measurement.

    Science.gov (United States)

    Müller, Wolfram; Horn, Martin; Fürhapter-Rieger, Alfred; Kainz, Philipp; Kröpfl, Julia M; Maughan, Ronald J; Ahammer, Helmut

    2013-11-01

    Extremely low weight and rapid changes in weight and body composition have become major concerns in many sports, but sufficiently accurate field methods for body composition assessment in athletes are missing. This study aimed to explore the use of ultrasound methods for assessment of body fat content in athletes. 19 female athletes (stature: 1.67(± 0.06) m, weight: 59.6(± 7.6) kg; age: 19.5(± 3.3) years) were investigated by three observers using a novel ultrasound method for thickness measurement of uncompressed subcutaneous adipose tissue and of embedded structures. Two observers also measured skinfold thickness at eight International Society for the Advancement of Kinanthrometry (ISAK) sites; mean skinfold values were compared to mean subcutaneous adipose tissue thicknesses measured by ultrasound. Interobserver reliability of imaging and evaluation obtained by this ultrasound technique: intraclass correlation coefficient ICC=0.968 (95% CI 0.957 to 0.977); evaluation of given images: ICC=0.997 (0.993 to 0.999). Skinfold compared to ultrasound thickness showed that compressibility of subcutaneous adipose tissue depends largely on the site and the person: regression slopes ranged from 0.61 (biceps) to 1.59 (thigh) and CIs were large. Limits of agreement ranged from 2.6 to 8.6 mm. Regression lines did not intercept the skinfold axis at zero because of the skin thickness being included in the skinfold. The four ISAK trunk sites caused ultrasound imaging problems in 13 of 152 sites (8 ISAK sites, 19 athletes). The ultrasound method allows measurement of uncompressed subcutaneous adipose tissue thickness with an accuracy of 0.1-0.5 mm, depending on the probe frequency. Compressibility of the skinfold depends on the anatomical site, and skin thickness varies by a factor of two. This inevitably limits the skinfold methods for body fat estimation. Ultrasound accuracy for subcutaneous adipose tissue measurement is limited by the plasticity of fat and furrowed tissue

  2. Joint angle measurement: a comparative study of the reliability of goniometry and wire tracing for the hand.

    Science.gov (United States)

    Ellis, B; Bruton, A; Goddard, J R

    1997-11-01

    To compare the inter- and intra-rater reliability of goniometry and wire tracing in the assessment of finger joint angles: metacarpo-phalangeal (MCPJ), proximal (PIPJ) and distal interphalangeal joints (DIPJ). Twenty occupational therapists and 20 physiotherapists with a range of clinical experience were recruited from nine different centres. Using a masked goniometer and wire tracing they carried out repeated assessments of the MCPJ, PIPJ and DIPJ of a normal subject fixed in two different positions. The two assessment methods did not produce comparable angle measurements. Goniometry showed greater inter- and intra-rater reliability than wire tracing. Regardless of the assessment tool, the repeatability coefficient indicated that DIPJ measurement was less reliable than the other joints. Clinical and specialist experience did not affect reliability. Although both goniometry and wire tracing show limitations as reliable assessment tools, it is recommended that where possible goniometry should be used.

  3. Comparative evaluation of the tridimensional spine position measured with a new instrument (Vertebral Metrics) and an optoelectronic system of stereophotogrammetry.

    Science.gov (United States)

    Quaresma, Cláudia; João, Filipa; Fonseca, Miguel; Secca, Mário Forjaz; Veloso, António; O'Neill, João Goyri; Branco, Jorge

    2010-11-01

    We designed and built a non-invasive instrument, called Vertebral Metrics, to measure the x, y, and z positions of each spinous process of the spine on a standing position. In the present study, we perform a comparative evaluation of Vertebral Metrics, by comparing the results obtained from this instrument with those from a validated optoelectronic system of stereophotogrammetry, with 10 infrared cameras. The sample was composed of 11 women aged between 14 and 39 years. After marking the various points on the spinal column, from the first cervical vertebra to the first sacral vertebra, they were measured first with the new instrument (Vertebral Metrics) and then by means of the optoelectronics system. Afterwards, the results were subjected to a thorough comparison. The statistical comparison of the results was performed using an ANOVA model with three factors (Instrument, Subject, and Vertebra) for the intervertebral distance.

  4. Large Scale Computations in Air Pollution Modelling

    DEFF Research Database (Denmark)

    Zlatev, Z.; Brandt, J.; Builtjes, P. J. H.

    Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998......Proceedings of the NATO Advanced Research Workshop on Large Scale Computations in Air Pollution Modelling, Sofia, Bulgaria, 6-10 July 1998...

  5. Sex Differences in Neuropsychological Function and Manganese in Air, Blood, Hair, and Toenails in Ohio Residents

    Science.gov (United States)

    Background: This study compares manganese (Mn) in air, blood, hair, and toenails and neuropsychological function of 110 women and 76 men, environmentally exposed to Mn in air (Mn-air) in two Ohio towns from a ferromanganese smelter and a soil Mn-packaging facility.Method: Biomark...

  6. Assuming measurement invariance of background indicators in international comparative educational achievement studies: a challenge for the interpretation of achievement differences

    Directory of Open Access Journals (Sweden)

    Heike Wendt

    2017-03-01

    Full Text Available Abstract Background Large-scale cross-national studies designed to measure student achievement use different social, cultural, economic and other background variables to explain observed differences in that achievement. Prior to their inclusion into a prediction model, these variables are commonly scaled into latent background indices. To allow cross-national comparisons of the latent indices, measurement invariance is assumed. However, it is unclear whether the assumption of measurement invariance has some influence on the results of the prediction model, thus challenging the reliability and validity of cross-national comparisons of predicted results. Methods To establish the effect size attributed to different degrees of measurement invariance, we rescaled the ‘home resource for learning index’ (HRL for the 37 countries ( $$n=166,709$$ n = 166 , 709 students that participated in the IEA’s combined ‘Progress in International Reading Literacy Study’ (PIRLS and ‘Trends in International Mathematics and Science Study’ (TIMSS assessments of 2011. We used (a two different measurement models [one-parameter model (1PL and two-parameter model (2PL] with (b two different degrees of measurement invariance, resulting in four different models. We introduced the different HRL indices as predictors in a generalized linear mixed model (GLMM with mathematics achievement as the dependent variable. We then compared three outcomes across countries and by scaling model: (1 the differing fit-values of the measurement models, (2 the estimated discrimination parameters, and (3 the estimated regression coefficients. Results The least restrictive measurement model fitted the data best, and the degree of assumed measurement invariance of the HRL indices influenced the random effects of the GLMM in all but one country. For one-third of the countries, the fixed effects of the GLMM also related to the degree of assumed measurement invariance. Conclusion The

  7. Comparing Food Provided and Wasted before and after Implementing Measures against Food Waste in Three Healthcare Food Service Facilities

    Directory of Open Access Journals (Sweden)

    Christina Strotmann

    2017-08-01

    Full Text Available The aim of the study was to reduce food waste in a hospital, a hospital cafeteria, and a residential home by applying a participatory approach in which the employees were integrated into the process of developing and implementing measures. Initially, a process analysis was undertaken to identify the processes and structures existing in each institution. This included a 2-week measurement of the quantities of food produced and wasted. After implementing the measures, a second measurement was conducted and the results of the two measurements were compared. The average waste rate in the residential home was significantly reduced from 21.4% to 13.4% and from 19.8% to 12.8% in the cafeteria. In the hospital, the average waste rate remained constant (25.6% and 26.3% during the reference and control measurements. However, quantities of average daily food provided and wasted per person in the hospital declined. Minimizing overproduction, i.e., aligning the quantity of meals produced to that required, is essential to reducing serving losses. Compliance of meal quality and quantity with customer expectations, needs, and preferences, i.e., the individualization of food supply, reduces plate waste. Moreover, establishing an efficient communication structure involving all actors along the food supply chain contributes to decreasing food waste.

  8. Comparing the performance of the EQ-5D and SF-6D when measuring the benefits of alleviating knee pain

    Directory of Open Access Journals (Sweden)

    Avery Anthony J

    2009-07-01

    Full Text Available Abstract Objective To assess the practicality, validity and responsiveness of using each of two utility measures (the EQ-5D and SF-6D to measure the benefits of alleviating knee pain. Methods Participants in a randomised controlled trial, which was designed to compare four different interventions for people with self-reported knee pain, were asked to complete the EQ-5D, SF-6D, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC at both pre- and post-intervention. For both utility measures, we assessed their practicality (completion rate, construct validity (ability to discriminate between baseline WOMAC severity levels, and responsiveness (ability to discriminate between three groups: those whose total WOMAC score, i did not improve, ii improved by Results The EQ-5D was completed by 97.7% of the 389 participants, compared to 93.3% for the SF-6D. Both the EQ-5D and SF-6D were able to discriminate between participants with different levels of WOMAC severity (p Conclusion The EQ-5D and SF-6D had largely comparable practicality and construct validity. However, in contrast to the EQ-5D, the SF-6D could not discriminate between those who improved post-intervention, and those who did not. This suggests that it is more appropriate to use the EQ-5D in future cost-effectiveness analyses of interventions which are designed to alleviate knee pain. Trial registration Current Controlled Trials ISRCTN93206785

  9. Comparing parameterized versus measured microphysical properties of tropical convective cloud bases during the ACRIDICON–CHUVA campaign

    Directory of Open Access Journals (Sweden)

    R. C. Braga

    2017-06-01

    Full Text Available The objective of this study is to validate parameterizations that were recently developed for satellite retrievals of cloud condensation nuclei supersaturation spectra, NCCN(S, at cloud base alongside more traditional parameterizations connecting NCCN(S with cloud base updrafts and drop concentrations. This was based on the HALO aircraft measurements during the ACRIDICON–CHUVA campaign over the Amazon region, which took place in September 2014. The properties of convective clouds were measured with a cloud combination probe (CCP, a cloud and aerosol spectrometer (CAS-DPOL, and a CCN counter onboard the HALO aircraft. An intercomparison of the cloud drop size distributions (DSDs and the cloud water content (CWC derived from the different instruments generally shows good agreement within the instrumental uncertainties. To this end, the directly measured cloud drop concentrations (Nd near cloud base were compared with inferred values based on the measured cloud base updraft velocity (Wb and NCCN(S spectra. The measurements of Nd at cloud base were also compared with drop concentrations (Na derived on the basis of an adiabatic assumption and obtained from the vertical evolution of cloud drop effective radius (re above cloud base. The measurements of NCCN(S and Wb reproduced the observed Nd within the measurements uncertainties when the old (1959 Twomey's parameterization was used. The agreement between the measured and calculated Nd was only within a factor of 2 with attempts to use cloud base S, as obtained from the measured Wb, Nd, and NCCN(S. This underscores the yet unresolved challenge of aircraft measurements of S in clouds. Importantly, the vertical evolution of re with height reproduced the observation-based nearly adiabatic cloud base drop concentrations, Na. The combination of these results provides aircraft observational support for the various components of the satellite-retrieved methodology that was recently developed to

  10. Comparing two distance measures in the spatial mapping of food deserts: The case of Petržalka, Slovakia

    Directory of Open Access Journals (Sweden)

    Bilková Kristína

    2017-06-01

    Full Text Available Over the last twenty years or so, researchers’ attention to the issue of food deserts has increased in the geographical literature. Accessibility to large-scale retail units is one of the essential and frequently-used indicators leading to the identification and mapping of food deserts. Numerous accessibility measures of various types are available for this purpose. Euclidean distance and street network distance rank among the most frequently-used approaches, although they may lead to slightly different results. The aim of this paper is to compare various approaches to the accessibility to food stores and to assess the differences in the results gained by these methods. Accessibility was measured for residential block centroids, with applications of various accessibility measures in a GIS environment. The results suggest a strong correspondence between Euclidean distance and a little more accurate street network distance approach, applied in the case of the urban environment of Bratislava-Petržalka, Slovakia.

  11. A comparative study of the evolution of the geographical ideas and measurements until the time of Eratosthenes

    Science.gov (United States)

    Pinotsis, Antonios D.

    2005-04-01

    We perform a comparative study of the evolution of the most important methods for geographical, carto-graphical and astronomical measurements developed by ancient Greek scientists and philosophers until the time of Eratosthenes. It seems that the novel geometrical method invented by Eratosthenes for the measurement of the size of the Earth did not appear suddenly but was the final outcome of long-lasting intellectual activity. It is shown that Anaximander, Pytheas, Eudoxus of Cnidus, Dicaearchus, Aristotle and Archimedes, the most famous ancient Greek philosopher astronomers and geographers before Eratosthenes, affected his thinking and contributed to his discovery. Furthermore, we briefly describe and explain the method of Eratosthenes, its significance, new errors that intruded into Eratosthenes’ measurement, as well as its application for the determination of the shape and the size of the Earth.

  12. A Comparative Study of the Applied Methods for Estimating Deflection of the Vertical in Terrestrial Geodetic Measurements

    Directory of Open Access Journals (Sweden)

    Luca Vittuari

    2016-04-01

    Full Text Available This paper compares three different methods capable of estimating the deflection of the vertical (DoV: one is based on the joint use of high precision spirit leveling and Global Navigation Satellite Systems (GNSS, a second uses astro-geodetic measurements and the third gravimetric geoid models. The working data sets refer to the geodetic International Terrestrial Reference Frame (ITRF co-location sites of Medicina (Northern, Italy and Noto (Sicily, these latter being excellent test beds for our investigations. The measurements were planned and realized to estimate the DoV with a level of precision comparable to the angular accuracy achievable in high precision network measured by modern high-end total stations. The three methods are in excellent agreement, with an operational supremacy of the astro-geodetic method, being faster and more precise than the others. The method that combines leveling and GNSS has slightly larger standard deviations; although well within the 1 arcsec level, which was assumed as threshold. Finally, the geoid model based method, whose 2.5 arcsec standard deviations exceed this threshold, is also statistically consistent with the others and should be used to determine the DoV components where local ad hoc measurements are lacking.

  13. A Comparative Study of the Applied Methods for Estimating Deflection of the Vertical in Terrestrial Geodetic Measurements

    Science.gov (United States)

    Vittuari, Luca; Tini, Maria Alessandra; Sarti, Pierguido; Serantoni, Eugenio; Borghi, Alessandra; Negusini, Monia; Guillaume, Sébastien

    2016-01-01

    This paper compares three different methods capable of estimating the deflection of the vertical (DoV): one is based on the joint use of high precision spirit leveling and Global Navigation Satellite Systems (GNSS), a second uses astro-geodetic measurements and the third gravimetric geoid models. The working data sets refer to the geodetic International Terrestrial Reference Frame (ITRF) co-location sites of Medicina (Northern, Italy) and Noto (Sicily), these latter being excellent test beds for our investigations. The measurements were planned and realized to estimate the DoV with a level of precision comparable to the angular accuracy achievable in high precision network measured by modern high-end total stations. The three methods are in excellent agreement, with an operational supremacy of the astro-geodetic method, being faster and more precise than the others. The method that combines leveling and GNSS has slightly larger standard deviations; although well within the 1 arcsec level, which was assumed as threshold. Finally, the geoid model based method, whose 2.5 arcsec standard deviations exceed this threshold, is also statistically consistent with the others and should be used to determine the DoV components where local ad hoc measurements are lacking. PMID:27104544

  14. Evaluation of w values for carbon beams in air, using a graphite calorimeter.

    Science.gov (United States)

    Sakama, Makoto; Kanai, Tatsuaki; Fukumura, Akifumi; Abe, Kyoko

    2009-03-07

    Despite recent progress in carbon therapy, accurate values for physical data such as the w value in air or stopping power ratios for ionization chamber dosimetry have not been obtained. The absorbed dose to graphite obtained with the graphite calorimeter was compared with that obtained using the ionization chambers following the IAEA protocol in order to evaluate the w values in air for mono-energetic carbon beams of 135, 290, 400 and 430 MeV/n. Two cylindrical chambers (PTW type 30001 and PTW type 30011, Farmer) and two plane-parallel chambers (PTW type 23343, Markus and PTW type 34001, Roos) calibrated by the absorbed dose to graphite and exposure to the (60)Co photon beam were used. The comparisons to our calorimeter measurements revealed that, using the ionization chambers, the absorbed dose to graphite comes out low by 2-6% in this experimental energy range and with these chamber types and calibration methods. In the therapeutic energy range, the w values in air for carbon beams indicated a slight energy dependence; we, however, assumed these values to be constant for practical use because of the large uncertainty and unknown perturbation factors of the ionization chambers. The w values in air of the carbon beams were evaluated to be 35.72 J C(-1) +/- 1.5% in the energy range used in this study. This value is 3.5% larger than that recommended by the IAEA TRS 398 for heavy-ion beams. Using this evaluated result, the absorbed dose to water in the carbon beams would be increased by the same amount.

  15. Nitrogen fluorescence in air for observing extensive air showers

    CERN Document Server

    Keilhauer, B; Fraga, M; Matthews, J; Sakaki, N; Tameda, Y; Tsunesada, Y; Ulrich, A

    2012-01-01

    Extensive air showers initiate the fluorescence emissions from nitrogen molecules in air. The UV-light is emitted isotropically and can be used for observing the longitudinal development of extensive air showers in the atmosphere over tenth of kilometers. This measurement technique is well-established since it is exploited for many decades by several cosmic ray experiments. However, a fundamental aspect of the air shower analyses is the description of the fluorescence emission in dependence on varying atmospheric conditions. Different fluorescence yields affect directly the energy scaling of air shower reconstruction. In order to explore the various details of the nitrogen fluorescence emission in air, a few experimental groups have been performing dedicated measurements over the last decade. Most of the measurements are now finished. These experimental groups have been discussing their techniques and results in a series of \\emph{Air Fluorescence Workshops} commenced in 2002. At the 8$^{\\rm{th}}$ Air Fluoresc...

  16. Atmospheric measurements of total OH reactivity: Intercomparison of the pump-probe technique and the comparative reactivity method

    Science.gov (United States)

    Dusanter, Sebastien; Hansen, Robert; Leonardis, Thierry; Schoemaecker, Coralie; Blocquet, Marion; Fittschen, Christa; Hanoune, Benjamin; Sinha, Vinayak; Stevens, Philip; Locoge, Nadine

    2013-04-01

    The hydroxyl radical (OH) drives the oxidation of organic trace gases that can lead to the production of ozone and secondary organic aerosols in the atmosphere. A complete understanding of the sources and sinks of OH is therefore important to address issues related to both air quality and climate change. However, recent measurements of total OH reactivity [1-2], which is the inverse of the OH lifetime, have pointed out that our understanding of OH sinks is still incomplete and important reactive trace gases have not yet been identified. These measurements of total OH reactivity are of particular interest since they provide a critical test of our understanding of the OH budget. Three techniques are available to measure the total OH reactivity, including the total OH loss rate method [3], the pump-probe method [4], and the comparative reactivity method (CRM) [5]. While the first two methods are based on direct measurements of OH decays using laser-induced fluorescence instruments, the CRM is based on a different approach in which a tracer molecule is detected instead of OH to determine the ambient OH loss rate. As these instruments were deployed in different field campaigns, intercomparison exercises would be useful to ensure the accuracy of the measurements. However, such intercomparisons have not yet been published. An informal intercomparison involving a CRM instrument from the Ecole des Mines de Douai (EMD) and a pump-probe instrument from the laboratory Physicochimie des Processus de Combustion et de l'Atmosphere (PC2A) took place in an urban environment at the university of Lille (France). The two OH reactivity instruments measured continuously side by side for a duration of two weeks. Collocated measurements of trace gases were also performed using O3, NOx and SO2 monitors, as well as two automated chromatographic instruments capable of measuring more than 50 volatile organic compounds (VOC). We will present cross calibrations of the two OH reactivity

  17. Caliper vs. Lipometer--Comparing Two Methods of Subcutaneous Body Fat Measurement by Bland-Altman Diagrams.

    Science.gov (United States)

    Tafeit, Erwin; Kaimbacher, Petra Silke; Wallner-Liebmann, Sandra Johanna; Reibnegger, Gilbert; Cvirn, Gerhard; Jürimäe, Jaak; Saar, Meeli; Maestu, Jarek; Purge, Priit; Lätt, Evelin; Jürimäe, Toivo

    2015-09-01

    Skinfold Calipers are widely used to obtain subcutaneous adipose tissue thickness because of its non-invasive, simple and inexpensive technique. Nevertheless, Caliper skinfold thicknesses have the disadvantage of measuring compressed adipose tissue and double layers of skin, which might reduce the precision of these results. In contrast, the computerized optical device Lipometer was developed to permit a quick, precise and non-invasive determination of non-compressed mono layers of subcutaneous adipose tissue thickness. In the present paper we investigate the hypothesis that Caliper skinfold thicknesses are significantly different from subcutaneous adipose tissue thicknesses in mm, which can be measured by Lipometer. Caliper and Lipometer results were obtained from 371 Estonian boys aged between 9.0 and 12.8 years. Measurements were performed at six different body sites: triceps, biceps, upper back, upper abdomen, hip and front thigh. Caliper measurements were systematically higher than Lipometer results in a range between 1.2 mm (hip) and 11.08 mm (front thigh). The limits of agreement analysis provided intervals from 7.5 mm (biceps) up to 30.14 mm (front thigh). Comparing Caliper and Lipometer results very low measurement agreement was found. The two methods provided very poor interchangeability.

  18. Measurement of plantarflexor spasticity in traumatic brain injury: correlational study of resistance torque compared with the modified Ashworth scale.

    Science.gov (United States)

    Annaswamy, Thiru; Mallempati, Srinivas; Allison, Stephen C; Abraham, Lawrence D

    2007-05-01

    To examine the usefulness of a biomechanical measure, resistance torque (RT), in quantifying spasticity by comparing its use with a clinical scale, the modified Ashworth scale (MAS), and quantitative electrophysiological measures. This is a correlational study of spasticity measurements in 34 adults with traumatic brain injury and plantarflexor spasticity. Plantarflexor spasticity was measured in the seated position before and after cryotherapy using the MAS and also by strapping each subject's foot and ankle to an apparatus that provided a ramp and hold stretch. The quantitative measures were (1) reflex threshold angle (RTA) calculated through electromyographic signals and joint angle traces, (2) Hdorsiflexion (Hdf)/Hcontrol (Hctrl) amplitude ratio obtained through reciprocal inhibition of the soleus H-reflex, (3) Hvibration (Hvib)/Hctrl ratio obtained through vibratory inhibition of the soleus H-reflex, and (4) RT calculated as the time integral of the torque graph between the starting and ending pulses of the stretch. Correlation coefficients between RT and MAS scores in both pre-ice (0.41) and post-ice trials (0.42) were fair (P = 0.001). The correlation coefficients between RT scores and RTA scores in both the pre-ice (0.66) and post-ice trials (0.75) were moderate (P spasticity.

  19. Multidetector-row computed tomography allows accurate measurement of mechanical prosthetic heart valve leaflet closing angles compared with fluoroscopy.

    Science.gov (United States)

    Suchá, Dominika; Symersky, Petr; Vonken, Evert-Jan P A; Provoost, Esther; Chamuleau, Steven A J; Budde, Ricardo P J

    2014-01-01

    The purpose of this study was to compare multidetector-row computed tomography (MDCT) leaflet restriction measurements with fluoroscopy measurements in commonly used mechanical prosthetic heart valves (PHVs). Four mechanical PHVs (ON-X, Carbomedics, St. Jude, and Medtronic Hall) were imaged in a pulsatile model using fluoroscopy and 64-detector-row computed tomography. Five image acquisitions of each PHV without (1) and with (4) restricted leaflet closure were made. Three observers measured closure angles on fluoroscopy and MDCT. Data were analyzed using intraclass correlation coefficient (ICC) and Bland-Altman plots. Interobserver agreement was high in restricted and non-restricted leaflets on both modalities (ICCs >0.995). MDCT and fluoroscopy showed high agreements (ICCs >0.989). Median MDCT closure angle measurements differed at most -2 to +2 degrees from fluoroscopy in the restricted and -1 to +2 degrees in the non-restricted leaflets. MDCT allows measurement of leaflet motion with a maximal median discrepancy of 2 degrees. Both MDCT and fluoroscopy detect restricted leaflet closure with great accuracy.

  20. Quantifying unruptured giant intracranial aneurysms by measuring diameter and volume--a comparative analysis of 69 cases.

    Science.gov (United States)

    Dengler, Julius; Maldaner, Nicolai; Bijlenga, Philippe; Burkhardt, Jan-Karl; Graewe, Alexander; Guhl, Susanne; Nakamura, Makoto; Hohaus, Christian; Kursumovic, Adisa; Schmidt, Nils Ole; Schebesch, Karl-Michael; Wostrack, Maria; Vajkoczy, Peter; Mielke, Dorothee

    2015-03-01

    Intracranial aneurysms (IA) are usually quantified according to their largest diameter. However, volumetry has recently been increasingly conducted as well, especially in giant intracranial aneurysms (GIAs). Since so far the true value of GIA volumetry is unknown, we designed a trial to examine correlations between GIA diameter and volume with special focus on clinical implications. Magnetic resonance imaging of 69 unruptured GIAs in 66 patients was retrospectively evaluated. The largest diameter and volume were measured. Also, potential associations to the patients' clinical conditions were examined. Comparing GIA sizes of our patient cohort produced different results depending on whether GIA diameter or volume was measured. Measuring the diameter identified posterior circulation GIAs as the largest ones (39.2 mm, IQR 37.3-48.3), while measuring the volume found GIAs of the MCA to be the largest ones (12.3 cm(3), IQR 7.2-27.8). A correlation of GIA diameter and volume was only found in anterior circulation GIAs, which were predominantly saccular in shape, but not in those of the posterior circulation, of which most were fusiform. Neither GIA diameter nor GIA volume but only GIA location was associated with neurological deficits. Diameter and volume measurements are not interchangeable modes of GIA quantification. Our data suggest that the idea of distinguishing different sizes of GIA may be clinically less relevant than examining their location, shape or mass effect.

  1. Athletes trained using stable compared to unstable surfaces exhibit distinct postural control profiles when assessed by traditional and nonlinear measures.

    Science.gov (United States)

    Powell, Douglas W; Williams, D S Blaise

    2015-12-01

    Athletes are assumed to exhibit better balance than non-athletes; however, few studies have examined the role of different types of sports on balance measures. Two athlete groups that experience divergent sport-specific balance training are stable- (i.e. basketball) and unstable-surface athletes (i.e. surfers). The purpose of this study was to quantify the effect of stable- compared to unstable-surface sports on postural stability. Eight non-athletes (NON), eight stable-surface athletes (SSA) and eight unstable-surface athletes (USA) performed five 20-s quiet standing trials while ground reaction forces were recorded. Approximate entropy (ApEn), total excursion and root mean square distances (RMS) of the center of pressure position were calculated. Univariate ANOVAs with post hoc tests were conducted for each variable. ApEn values were lower in SSA compared to NON in the ML direction (p=0.012) and USA had lower ApEn values compared to SSA in the AP direction (p=0.036). The USA had smaller AP RMS compared to SSA (p=0.002) while the USA had greater ML RMS (p=0.008) and resultant RMS values compared to SSA (p=0.025). These data suggest that USA and SSA may exhibit direction-specific differences in balance strategy due to feedback paradigm. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. The reliability of a smartphone goniometer application compared with a traditional goniometer for measuring first metatarsophalangeal joint dorsiflexion.

    Science.gov (United States)

    Otter, Simon J; Agalliu, Brunilda; Baer, Nicola; Hales, Georgie; Harvey, Katrina; James, Keeley; Keating, Richard; McConnell, Warren; Nelson, Rachel; Qureshi, Saddaf; Ryan, Steven; St John, Abigail; Waddington, Heather; Warren, Katie; Wong, Duane

    2015-01-01

    Adequate sagittal plane motion of the first metatarsalphalangeal joint (1st MTPJ) is important during normal gait and goniometric measurement is commonly used as a diagnostic and outcome assessment tool. We aimed to determine the intra and inter-rater reliability together with the concurrent validity of a universal plastic goniometer (UG) and a smartphone applicationlication (Dr G) for the measurement of dorsiflexion at the 1st MTPJ. Measurement of joint position and passive range of motion of the 1st MTPJ dorsiflexion was compared using a UG and DrG goniometer. A double-blind repeated measures design was utilized, with intraclass correlation coefficient (ICC) used to determine levels of reliability. For joint position good intra-rater reliability (ICC >0.861) and good inter-rater reliability (ICC >0.823) was noted. However, the Dr G application consistently measured lower angles (mean 27.8° (SD 8.37)) than the UG (mean 32° (SD 11.7)) and these associations were significant (r = 0.399, p application. Both instruments demonstrated high levels of intra-rater reliability (ICC >0.809). Inter-rater reliability was moderate to good for the UG (ICC 0.693 (95 % CI 0.580 to 0.788)) and good for the Dr G application (ICC 0.708 (95 % CI 0.597 to 0.799)). Moderate to high intra and inter-rater reliability of joint position and passive 1st MTPJ motion can be achieved with traditional and smartphone-based goniometric measurement. The Dr G application may provide a slightly higher reliability, but devices should not be used inter-changeably as significant variation in measurement between devices may occur.

  3. Is quality of colorectal cancer care good enough? Core measures development and its application for comparing hospitals in Taiwan

    Directory of Open Access Journals (Sweden)

    Cheng Skye H

    2010-01-01

    Full Text Available Abstract Background Although performance measurement for assessing care quality is an emerging area, a system for measuring the quality of cancer care at the hospital level has not been well developed. The purpose of this study was to develop organization-based core measures for colorectal cancer patient care and apply these measures to compare hospital performance. Methods The development of core measures for colorectal cancer has undergone three stages including a modified Delphi method. The study sample originated from 2004 data in the Taiwan Cancer Database, a national cancer data registry. Eighteen hospitals and 5585 newly diagnosed colorectal cancer patients were enrolled in this study. We used indicator-based and case-based approaches to examine adherences simultaneously. Results The final core measure set included seventeen indicators (1 pre-treatment, 11 treatment-related and 5 monitoring-related. There were data available for ten indicators. Indicator-based adherence possesses more meaningful application than case-based adherence for hospital comparisons. Mean adherence was 85.8% (79.8% to 91% for indicator-based and 82.8% (77.6% to 88.9% for case-based approaches. Hospitals performed well (>90% for five out of eleven indicators. Still, the performance across hospitals varied for many indicators. The best and poorest system performance was reflected in indicators T5-negative surgical margin (99.3%, 97.2% - 100.0% and T7-lymph nodes harvest more than twelve(62.7%, 27.6% - 92.2%, both of which related to surgical specimens. Conclusions In this nationwide study, quality of colorectal cancer care still shows room for improvement. These preliminary results indicate that core measures for cancer can be developed systematically and applied for internal quality improvement.

  4. The Quest for Comparability: Studying the Invariance of the Teachers’ Sense of Self-Efficacy (TSES) Measure across Countries

    Science.gov (United States)

    Scherer, Ronny; Jansen, Malte; Nilsen, Trude; Areepattamannil, Shaljan; Marsh, Herbert W.

    2016-01-01

    Teachers’ self-efficacy is an important motivational construct that is positively related to a variety of outcomes for both the teachers and their students. This study addresses challenges associated with the commonly used ‘Teachers’ Sense of Self-Efficacy (TSES)’ measure across countries and provides a synergism between substantive research on teachers’ self-efficacy and the novel methodological approach of exploratory structural equation modeling (ESEM). These challenges include adequately representing the conceptual overlap between the facets of self-efficacy in a measurement model (cross-loadings) and comparing means and factor structures across countries (measurement invariance). On the basis of the OECD Teaching and Learning International Survey (TALIS) 2013 data set comprising 32 countries (N = 164,687), we investigate the effects of cross-loadings in the TSES measurement model on the results of measurement invariance testing and the estimation of relations to external constructs (i.e., working experience, job satisfaction). To further test the robustness of our results, we replicate the 32-countries analyses for three selected sub-groups of countries (i.e., Nordic, East and South-East Asian, and Anglo-Saxon country clusters). For each of the TALIS 2013 participating countries, we found that the factor structure of the self-efficacy measure is better represented by ESEM than by confirmatory factor analysis (CFA) models that do not allow for cross-loadings. For both ESEM and CFA, only metric invariance could be achieved. Nevertheless, invariance levels beyond metric invariance are better achieved with ESEM within selected country clusters. Moreover, the existence of cross-loadings did not affect the relations between the dimensions of teachers’ self-efficacy and external constructs. Overall, this study shows that a conceptual overlap between the facets of self-efficacy exists and can be well-represented by ESEM. We further argue for the cross

  5. Comparative measurements of external radiation exposure using mobile phones, dental ceramic, household salt and conventional personal dosemeters

    International Nuclear Information System (INIS)

    Ekendahl, Daniela; Bulánek, Boris; Judas, Libor

    2015-01-01

    Because retrospective dosimetry utilises commonly occurring materials and objects, it is particularly useful in cases of large-scale radiation accidents or malevolent acts with radioactive materials where casualties are inflicted on the general public and first emergency responders. The aim of this study was to investigate whether retrospective dosemeters can provide dose estimates with comparable accuracy like conventional personal dosemeters. Using an external source of radiation 137 Cs and an anthropomorphic phantom, we simulated serious irradiation of a human body in anterior-posterior and rotational geometries. Retrospective luminescence dosimetry objects, such as mobile phones, dental ceramic and household salt, and conventional personal dosemeters (thermoluminescent and electronic) were fixed to the anthropomorphic phantom. The doses obtained were compared with specific reference values. In most cases, relative deviations between the measured doses and the reference values did not exceed 20%. As the retrospective and conventional dosemeters show no significant differences in laboratory conditions, the retrospective luminescence dosimetry objects represent a very promising tool if handled properly. - Highlights: • A serious external exposure of human body was simulated. • Doses were measured using both retrospective and conventional dosemeters. • Utilised retrospective dosimetry materials were alumina resistors from mobile phones, household salt and dental ceramic. • Doses obtained were compared with reference values. • Both retrospective and conventional dosemeters gave similar results

  6. Kerma determination in air on mamma by thermoluminescence

    International Nuclear Information System (INIS)

    Palacios P, L. L.; Rivera M, T.

    2009-10-01

    In this work the experimental results of the entrance exposition are shown and Kerma in air [mGy] in mamma obtained by irradiation of accreditation phantom of American College of Radiology (ACR). The irradiations were realized in a conventional mammography equipment of Hospital Juarez in Mexico; the technique used during the irradiations was of automatic exposition; the thickness for the phantom ACR obtained by the technique were of 4.2 and 4.5 cm; the kilo voltage pick was of 24 kV p , the time and the milli amperage per second variable. The measuring of Kerma in air was obtained with thermoluminescent dosemeters of solid state, of nano particles of zirconium dioxide prepared by the precipitation method. The dosemeters were homogenized previously in low energies of X-rays that are those used for mammography. The thermoluminescent dosemeters of ZrO 2 were calibrated by means of an ionization chamber for different expositions. The calibration curve is reported for the exposition and Kerma in air against thermoluminescent intensity obtained by reading of thermoluminescent dosemeters of ZrO 2 , as well as the technique employee for the Kerma determination in air and entrance exposition in mamma. (Author)

  7. Comparing contents of outcome measures in cerebral palsy using the International Classification of Functioning (ICF-CY): a systematic review.

    Science.gov (United States)

    Schiariti, Veronica; Klassen, Anne F; Cieza, Alarcos; Sauve, Karen; O'Donnell, Maureen; Armstrong, Robert; Mâsse, Louise C

    2014-01-01

    The International Classification of Functioning children and youth version (ICF-CY) provides a universal framework for defining and classifying functioning and disability in children worldwide. To facilitate the application of the ICF in practice, ICF based-tools like the "ICF Core Sets" are being developed. In the context of the development of the ICF-CY Core Sets for children with Cerebral Palsy (CP), the aims of this study were as follows: to identify and compare the content of outcome measures used in studies of children with CP using the ICF-CY coding system; and to describe the most frequently addressed areas of functioning in those studies. We searched multiple databases likely to capture studies involving children with CP from January 1998 to March 2012. We included all English language articles that studied children aged 2-18 years and described an interventional or observational study. Constructs of the outcome measures identified in studies were linked to the ICF-CY by two trained professionals. We found 231 articles that described 238 outcome measures. The outcome measures contained 2193 concepts that were linked to the ICF-CY and covered 161 independent ICF-CY categories. Out of the 161 categories, 53 (33.5%) were related to body functions, 75 (46%) were related to activities/participation, 26 (16.1%) were related to environmental factors, and 7 (4.3%) were related to body structures. This systematic review provides information about content of measures that may guide researchers and clinicians in their selection of an outcome measure for use in a study and/or clinical practice with children with CP. Copyright © 2013 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  8. Small field in-air output factors: The role of miniphantom design and dosimeter type

    International Nuclear Information System (INIS)

    Warrener, Kirbie; Hug, Benjamin; Ebert, Martin A.; Liu, Paul; McKenzie, David R.; Ralston, Anna; Suchowerska, Natalka

    2014-01-01

    Purpose: The commissioning of treatment planning systems and beam modeling requires measured input parameters. The measurement of relative output in-air, S c is particularly difficult for small fields. The purpose of this study was to investigate the influence of miniphantom design and detector selection on measured S c values for small fields and to validate the measurements against Monte Carlo simulations. Methods: Measurements were performed using brass caps (with sidewalls) or tops (no sidewalls) of varying heights and widths. The performance of two unshielded diodes (60012 and SFD), EBT2 radiochromic film, and a fiber optic dosimeter (FOD) were compared for fields defined by MLCs (5–100 mm) and SRS cones (4–30 mm) on a Varian Novalis linear accelerator. Monte Carlo simulations were performed to theoretically predict S c as measured by the FOD. Results: For all detectors, S c agreed to within 1% for fields larger than 10 mm and to within 2.3% for smaller fields. Monte Carlo simulation matched the FOD measurements for all size of cone defined fields to within 0.5%. Conclusions: Miniphantom design is the most important variable for reproducible and accurate measurements of the in-air output ratio, S c , in small photon fields (less than 30 mm). Sidewalls are not required for fields ≤ 30 mm and tops are therefore preferred over the larger caps. Unlike output measurements in water, S cp, the selection of detector type for S c is not critical, provided the active dosimeter volume is small relative to the field size

  9. Small field in-air output factors: The role of miniphantom design and dosimeter type

    Energy Technology Data Exchange (ETDEWEB)

    Warrener, Kirbie, E-mail: kirbie.warrener@sesiahs.health.nsw.gov.au [Illawarra Cancer Care Centre, Wollongong Hospital, Wollongong, New South Wales 2521, Australia and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2522 (Australia); Hug, Benjamin; Ebert, Martin A. [School of Physics, University of Western Australia, Crawley, Western Australia 6009, Australia and Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Western Australia 6009 (Australia); Liu, Paul; McKenzie, David R. [School of Physics, University of Sydney, Darlington, New South Wales 2008 (Australia); Ralston, Anna [Chris O' Brien Lifehouse, Radiation Oncology, Sydney, New South Wales 2050 (Australia); Suchowerska, Natalka [School of Physics, University of Sydney, Darlington, New South Wales 2008, Australia and Chris O' Brien Lifehouse, Radiation Oncology, Sydney, New South Wales 2050 (Australia)

    2014-02-15

    Purpose: The commissioning of treatment planning systems and beam modeling requires measured input parameters. The measurement of relative output in-air, S{sub c} is particularly difficult for small fields. The purpose of this study was to investigate the influence of miniphantom design and detector selection on measured S{sub c} values for small fields and to validate the measurements against Monte Carlo simulations. Methods: Measurements were performed using brass caps (with sidewalls) or tops (no sidewalls) of varying heights and widths. The performance of two unshielded diodes (60012 and SFD), EBT2 radiochromic film, and a fiber optic dosimeter (FOD) were compared for fields defined by MLCs (5–100 mm) and SRS cones (4–30 mm) on a Varian Novalis linear accelerator. Monte Carlo simulations were performed to theoretically predict S{sub c} as measured by the FOD. Results: For all detectors, S{sub c} agreed to within 1% for fields larger than 10 mm and to within 2.3% for smaller fields. Monte Carlo simulation matched the FOD measurements for all size of cone defined fields to within 0.5%. Conclusions: Miniphantom design is the most important variable for reproducible and accurate measurements of the in-air output ratio, S{sub c}, in small photon fields (less than 30 mm). Sidewalls are not required for fields ≤ 30 mm and tops are therefore preferred over the larger caps. Unlike output measurements in water, S{sub cp,} the selection of detector type for S{sub c} is not critical, provided the active dosimeter volume is small relative to the field size.

  10. Validating the appropriateness of TACOM measure: Comparing TACOM scores with subjective workload scores quantified by NASA-TLX technique

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.; Jung, W. [Integrated Safety Assessment Div., Korea Atomic Energy Research Inst., P.O.Box 105, Duckjin-Dong, Yusong-Ku, Taejon, 305-600 (Korea, Republic of)

    2006-07-01

    In this study, the appropriateness of the task complexity (TACOM) measure that can quantify the complexity of emergency tasks was investigated by comparing subjective workload scores with the associated TACOM scores. To this end, based on the NASA-TLX (task load index) technique, 18 operators were asked to subjectively estimate perceived workload for 23 emergency tasks that were specified in the emergency operating procedures of the reference nuclear power plants. As the result of comparisons, it was observed that subjective workload scores increase in proportion to the increase of TACOM scores. Therefore, it is expect that the TACOM measure can be used as a serviceable method to quantify the complexity of emergency tasks. (authors)

  11. Comparative study of size dependent four-point probe sheet resistance measurement on laser annealed ultra-shallow junctions

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Lin, Rong; Hansen, Torben Mikael

    2008-01-01

    In this comparative study, the authors demonstrate the relationship/correlation between macroscopic and microscopic four-point sheet resistance measurements on laser annealed ultra-shallow junctions (USJs). Microfabricated cantilever four-point probes with probe pitch ranging from 1.5 to 500 mu m...... have been used to characterize the sheet resistance uniformity of millisecond laser annealed USJs. They verify, both experimentally and theoretically, that the probe pitch of a four-point probe can strongly affect the measured sheet resistance. Such effect arises from the sensitivity (or "spot size......") of an in-line four-point probe. Their study shows the benefit of the spatial resolution of the micro four-point probe technique to characterize stitching effects resulting from the laser annealing process....

  12. A COMPARATIVE LOOK INTO HOW TO MEASURE THE EFFECTIVENESS OF VOCABULARY LEARNING STRATEGIES: THROUGH USING PERCENTAGES OR CORRELATION COEFFICIENTS

    Directory of Open Access Journals (Sweden)

    İsmail Hakkı ERTEN

    2008-10-01

    Full Text Available This study aims to compare the appropriateness of two statistical procedures for measuring the effectiveness of vocabulary learning strategies: percentages and correlation coefficients. To do this a group of 20 learners of English were asked to study 12 words in a written list, with their pronunciations, dictionary definitions, and example sentences. Data was collected through introspection where students were asked to verbalize their mental processes as they studied the target words. A pre-test and post-test were given to measure the task achievement. The qualitative data was transcribed verbatim and content-analysed for tokens of strategy use as well as by noting whether each use of strategies led to successful recall of the words on which they were used. To calculate the strategy effectiveness, both simple percentage calculation and correlation coefficients were employed for comparison. The findings indicated that percentage calculation can give a more realistic picture of strategy effectiveness than correlation coefficients.

  13. Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air

    Science.gov (United States)

    Lee, Jo Jo; Ghosh, Tushar K.; Loyalka, Sudarshan K.

    2018-03-01

    The oxidation rates of several nuclear-grade graphites, NBG-18, NBG-17, IG-110 and IG-11, were measured in air using thermogravimetry. Kinetic parameters and oxidation behavior for each grade were compared by coke type, filler grain size and microstructure. The thickness of the oxidized layer for each grade was determined by layer peeling and direct density measurements. The results for NBG-17 and IG-11 were compared with those available in the literature and our recently reported results for NBG-18 and IG-110 oxidation in air. The finer-grained graphites IG-110 and IG-11 were more oxidized than medium-grained NBG-18 and NBG-17 because of deeper oxidant penetration, higher porosity and higher probability of available active sites. Variation in experimental conditions also had a marked effect on the reported kinetic parameters by several studies. Kinetic parameters such as activation energy and transition temperature were sensitive to air flow rates as well as sample size and geometry.

  14. Comparative analysis of several detectors for the measurement of radiation transmission and leakage from a multileaf collimator.

    Science.gov (United States)

    Lárraga-Gutiérrez, J M; Galván de la Cruz, O O; García-Garduño, O A; Ballesteros-Zebadúa, P

    2014-05-01

    The multileaf collimator (MLC) is the standard device used to shape radiation beams for 3-d conformal and intensity-modulated radiation therapy (IMRT). Due to the inherent properties of MLC, there is a small amount of radiation transmitted through the leaves, called radiation transmission (RT). Accurate measurements of this radiation are required to commission and validate IMRT-capable treatment planning systems because this radiation may impact the dosimetry of IMRT-calculated dose distributions. This work compares several detectors in the measurement of RT for a micro-multileaf collimation system. The results show that there are statistically significant differences in the measured RT values between detectors from 3.5 to 12.5% for the same MLC model and less than 0.2% relative to the isocentre dose for an open reference field. However, although small in magnitude, these differences may impact the dosimetry of IMRT treatment planning by up to 1.78 Gy to the healthy tissue surrounding the target for a treatment of 60 Gy in 30 fractions. By the later, these differences must be included as a source of uncertainty in IMRT dose delivery. Also, it must be established which detector offers the most reliable results in the measurement of the RT by using Monte Carlo simulation methods. Copyright © 2013 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  15. OH and O3 in the MLT: Comparing MAHRSI and ORA measurements With the SOCRATES 2D-model

    Science.gov (United States)

    Chabrillat, S.; Kockarts, G.; Brasseur, G.; Fussen, D.; Fonteyn, D.

    2001-12-01

    New space-based measurements of two key chemical species in the MLT, OH and O3\\ , were recently published. The OH radical was measured for the first time in the stratosphere and the mesosphere by the MAHRSI instrument. Conway et al. [2000] showed the difficulty to explain these observations with a one-dimensional model. Ozone measurements were extracted from the ORA instrument, which uses solar occultation in the UV-visible wavelength range. More than 2500 vertical profiles of O3 at sunrise and sunset were obtained, up to 110 km altitude. This is the first ozone data set to extend above the mesopause, capturing the ozone secondary maximum in its totality. We compare these measurements with the results of the SOCRATES two-dimensional interactive model. The latest version of this model includes, among other improvements, an accurate calculation of the absorption of the Lyman-α solar line by O2\\ , molecular diffusion, and a parameterization of the gravity wave drag to accurately match the observed temperature distribution in the MLT - especially the temporal and spatial structure of the mesopause. We show that the observations of mesospheric OH and O3 in the MLT are reproduced in a very satisfactory manner using this new multi-dimensional model.

  16. Comparative measurements and seasonal variations in energy and carbon exchange over forest and pasture in South West Amazonia

    Science.gov (United States)

    von Randow, C.; Manzi, A. O.; Kruijt, B.; de Oliveira, P. J.; Zanchi, F. B.; Silva, R. L.; Hodnett, M. G.; Gash, J. H. C.; Elbers, J. A.; Waterloo, M. J.; Cardoso, F. L.; Kabat, P.

    Comparative measurements of radiation flux components and turbulent fluxes of energy and CO2 are made at two sites in South West Amazonia: one in a tropical forest reserve and one in a pasture. The data were collected from February 1999 to September 2002, as part of the Large Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). During the dry seasons, although precipitation and specific humidity are greatly reduced, the soil moisture storage profiles down to 3.4m indicate that the forest vegetation continues to withdraw water from deep layers in the soil. For this reason, seasonal changes observed in the energy partition and CO2 fluxes in the forest are small, compared to the large reductions in evaporation and photosynthesis observed in the pasture. For the radiation balance, the reflected short wave radiation increases by about 55% when changing from forest to pasture. Combined with an increase of 4.7% in long wave radiation loss, this causes an average reduction of 13.3% in net radiation in the pasture, compared to the forest. In the wet season, the evaporative fraction (λE/Rn) at the pasture is 17% lower than at the forest. This difference increases to 24% during the dry season. Daytime CO2 fluxes are 20-28% lower (in absolute values) in the pasture compared to the forest. The night-time respiration in the pasture is also reduced compared to the forest, with averages 44% and 57% lower in the wet and dry seasons, respectively. As the reduction in the nocturnal respiration is larger than the reduction in the daytime uptake, the combined effect is a 19-67% higher daily uptake of CO2 in the pasture, compared to the forest. This high uptake of CO2 in the pasture site is not surprising, since the growth of the vegetation is constantly renewed, as the cattle remove the biomass.

  17. Measuring multi-membership in economic integration and its trade-impact. A comparative study of ECOWAS and SADC

    DEFF Research Database (Denmark)

    Afesorgbor, Sylvanus Kwaku; van Bergeijk, Peter A.G.

    One of intriguing aspects of African Regional Trade Agreements (RTAs) is the extent of multi-membership, where many Africa countries are members of more than one RTA. Using a gravity model for 25 countries and the years 1980-2006 we measure the extent of multi-membership and compare its impact...... in two major African Regional blocs, ECOWAS and SADC. We find that the impact of multi-membership critically depends on the characteristics of the multi-membership of regional integration initiatives. We find a positive impact if an additional membership complements the integration process...

  18. Learning effect of isokinetic measurements in healthy subjects, and reliability and comparability of Biodex and Lido dynamometers

    DEFF Research Database (Denmark)

    Lund, Hans; Søndergaard, K; Zachariassen, T

    2005-01-01

    The aim of this study was to examine the learning effect during a set of isokinetic measurements, to evaluate the reliability of the Biodex System 3 PRO dynamometer, and to compare the Biodex System 3 PRO and the Lido Active dynamometers on both extension and flexion over the elbow and the knee...... extension (P = 0.18) and elbow extension (P = 0.63). However, elbow flexion showed a 14.8% (95% CI: 11.2-18.4%; P = 0.0001) higher peak torque on Biodex. In conclusion, no learning effect was observed and the Biodex proved to be a highly reliable isokinetic dynamometer. A difference was observed when...

  19. A New Measurement Equivalence Technique Based on Latent Class Regression as Compared with Multiple Indicators Multiple Causes.

    Science.gov (United States)

    Jamali, Jamshid; Ayatollahi, Seyyed Mohammad Taghi; Jafari, Peyman

    2016-06-01

    Measurement equivalence is an essential prerequisite for making valid comparisons in mental health questionnaires across groups. In most methods used for assessing measurement equivalence, which is known as Differential Item Functioning (DIF), latent variables are assumed to be continuous. To compare a new method called Latent Class Regression (LCR) designed for discrete latent variable with the multiple indicators multiple cause (MIMIC) as a continuous latent variable technique to assess the measurement equivalence of the 12-item General Health Questionnaire (GHQ-12), which is a cross deferent subgroup of Iranian nurses. A cross-sectional survey was conducted in 2014 among 771 nurses working in the hospitals of Fars and Bushehr provinces of southern Iran. To identify the Minor Psychiatric Disorders (MPD), the nurses completed self-report GHQ-12 questionnaires and sociodemographic questions. Two uniform-DIF detection methods, LCR and MIMIC, were applied for comparability when the GHQ-12 score was assumed to be discrete and continuous, respectively. The result of fitting LCR with 2 classes indicated that 27.4% of the nurses had MPD. Gender was identified as an influential factor of the level of MPD.LCR and MIMIC agree with detection of DIF and DIF-free items by gender, age, education and marital status in 83.3, 100.0, 91.7 and 83.3% cases, respectively. The results indicated that the GHQ-12 is to a great degree, an invariant measure for the assessment of MPD among nurses. High convergence between the two methods suggests using the LCR approach in cases of discrete latent variable, e.g. GHQ-12 and adequate sample size.

  20. Optical system for trapping particles in air.

    Science.gov (United States)

    Kampmann, R; Chall, A K; Kleindienst, R; Sinzinger, S

    2014-02-01

    An innovative optical system for trapping particles in air is presented. We demonstrate an optical system specifically optimized for high precision positioning of objects with a size of several micrometers within a nanopositioning and nanomeasuring machine (NPMM). Based on a specification sheet, an initial system design was calculated and optimized in an iterative design process. By combining optical design software with optical force simulation tools, a highly efficient optical system was developed. Both components of the system, which include a refractive double axicon and a parabolic ring mirror, were fabricated by ultra-precision turning. The characterization of the optical elements and the whole system, especially the force simulations based on caustic measurements, represent an important interim result for the subsequently performed trapping experiments. The caustic of the trapping beam produced by the system was visualized with the help of image processing techniques. Finally, we demonstrated the unique efficiency of the configuration by reproducibly trapping fused silica spheres with a diameter of 10 μm at a distance of 2.05 mm from the final optical surface.

  1. Search for bursts in air shower data

    International Nuclear Information System (INIS)

    Bruce, T.E.G.; Clay, R.W.; Dawson, B.R.; Protheroe, R.J.; Blair, D.G.; Cinquini, P.

    1985-01-01

    There have been reports in recent years of the possible observation of bursts in air shower data. If such events are truly of an astrophysical nature then, they represent an important new class of phemonenon since no other bursts have been observed above the MeV level. The spectra of conventional gamma ray bursts are unknown at higher energies but their observed spectra at MeV energies appear generally to exhibit a steepening in the higher MeV range and are thus unlikely to extrapolate to measurable fluxes at air shower energies. An attempt has been made to look for deviations from randomness in the arrival times of air showers above approx. 10 to the 14th power eV with a number of systems and results so far are presented here. This work will be continued for a substantial period of time with a system capable of recording bursts with multiple events down to a spacing of 4 microns. Earlier data have also been searched for the possible association of air shower events with a glitch of the Vela pulsar

  2. Coal char oxidation kinetics in air medium

    Directory of Open Access Journals (Sweden)

    Korotkikh Alexander G.

    2017-01-01

    Full Text Available Study of oxidation kinetics for three types of coal char with different carbon content in air is presented. The coal char powders of anthracite, bituminous T-grade coal and 2B-grade lignite with particle size less than 80 μm were tested. The coal char oxidation was researched by isothermal method via simultaneous TG-DSC analyzer Netzsch STA 449 Jupiter F3 in the temperature range of 1000–1200 °C. Measurements were carried out at ambient pressure. Volumetric flow rate of oxidizing medium into analyser chamber was 250 ml/min. Flow consisted of air and argon with volumetric ratio 24/1. Carbon average rate of oxidation reaction at each temperature were defined based on experimental results. Kinetic constants (the frequency factor and activation energy were defined for Arrhenius equation modified with three submodels: volumetric model, shrinking core model and random pore model. The activation energy values for anthracite are 1,6-1,7 times higher than for chars of bituminous coal and lignite.

  3. Reactive oxygen species measurement in neat and washed semen: comparative analysis and its significance in male infertility assessment.

    Science.gov (United States)

    Venkatesh, S; Shamsi, M B; Dudeja, S; Kumar, R; Dada, Rima

    2011-01-01

    Oxidative stress (OS) is a major concern in idiopathic male infertility as elevated levels of reactive oxygen species (ROS) in the semen is believed to adversely affect sperm functional competence and damage both nuclear and mitochondrial DNA. Therefore, identifying infertile men with seminal OS may be used as a valuable tool in the assessment of male infertility. Semen is a complex mixture of spermatozoa and seminal plasma which is rich in enzymatic and non-enzymatic antioxidants. However, the measurement of ROS in the semen and its application in male infertility assessment is poorly understood. The aim of the present study was to compare the significance of ROS measurement in washed and neat semen. The study included 65 infertile men with abnormal semen (SA) parameters, 17 infertile men with normal semen (NS) parameters and 43 fertile controls (FC). ROS levels in both washed and neat semen were measured by luminol-dependent chemiluminescence assay and the values were expressed as 10(4 )RLU per minute per 20 million spermatozoa. The levels of ROS in both washed and neat semen were found to be significantly higher (P neat semen 0.03, washed semen 0.24), whereas infertile men with SA group had the highest median ROS level (neat semen 3.44, washed semen 27.42). In all subjects, ROS levels were found to be higher in washed semen than in neat semen. A strong positive correlation (r = 0.847, P neat and washed semen was observed. Measurement of ROS in neat semen reflects the original oxidative status in the actual sperm microenvironment and is an easy, simple, inexpensive and rapid method compared with ROS measurement from washed semen. ROS measurement in washed semen is done to assess ROS levels following sperm processing as in cases opting for assisted conception. As both ROS values in neat and washed show a positive correlation, neat semen may be used as a valuable tool for identifying infertile men with seminal OS. ROS levels are elevated in nearly 70% men with

  4. Vibrationally-Fluidized Granular Flows: Impact and Bulk Velocity Measurements Compared with Discrete Element and Continuum Models

    Science.gov (United States)

    Hashemnia, Kamyar

    A new laser displacement probe was developed to measure the impact velocities of particles within vibrationally-fluidized beds. The sensor output was also used to measure bulk flow velocity along the probe window and to provide a measure of the media packing. The displacement signals from the laser sensors were analyzed to obtain the probability distribution functions of the impact velocity of the particles. The impact velocity was affected by the orientation of the laser probe relative to the bulk flow velocity, and the density and elastic properties of the granular media. The impact velocities of the particles were largely independent of their bulk flow speed and packing density. Both the local impact and bulk flow velocities within a tub vibratory finisher were predicted using discrete element modelling (DEM) and compared to the measured values for spherical steel media. It was observed that the impact and bulk flow velocities were relatively insensitive to uncertainties in the contact coefficients of friction and restitution. It was concluded that the predicted impact and bulk flow velocities were dependent on the number of layers in the model. Consequently, the final DE model mimicked the key aspects of the experimental setup, including the submerged laser sensor. The DE method predictions of both impact velocity and bulk flow velocity were in reasonable agreement with the experimental measurements, with maximum differences of 20% and 30%, respectively. Discrete element modeling of granular flows is effective, but requires large numerical models. In an effort to reduce computational effort, this work presents a finite element (FE) continuum model of a vibrationally-fluidized granular flow. The constitutive equations governing the continuum model were calibrated using the discrete element method (DEM). The bulk flow behavior of the equivalent continuum media was then studied using both Lagrangian and Eulerian FE formulations. The bulk flow velocities predicted

  5. Use of lanthanide catalysts in air electrodes

    International Nuclear Information System (INIS)

    Souza Parente, L.T. de

    1982-01-01

    A review on the lanthanide catalysts suitable for the reduction catalysis of oxygen in air electrodes is presented. The kinds of lanthanide indicated to be used as catalysts of oxygen reduction are shown. (A.R.H.) [pt

  6. The stability and generation pattern of thermally formed isocyanic acid (ICA) in air - potential and limitations of proton transfer reaction-mass spectrometry (PTR-MS) for real-time workroom atmosphere measurements.

    Science.gov (United States)

    Jankowski, Mikolaj Jan; Olsen, Raymond; Thomassen, Yngvar; Molander, Paal

    2016-07-13

    Isocyanic acid (ICA) in vapour phase has been reported to be of unstable nature, making the occupational hygienic relevance of ICA questionable. The stability of pure ICA in clean air at different humidity conditions was investigated by Fourier transform-infrared spectrometric (FT-IR) measurements. Furthermore, the stability of ICA in a complex atmosphere representative thermal degradation hot-work procedures were examined by performing parallel measurements by proton transfer reaction-mass spectrometric (PTR-MS) instrumentation and off-line denuder air sampling using di-n-butylamine (as a derivatization agent prior to liquid chromatography mass spectrometric (LC-MS) determination). The apparent half-life of ICA in pure ICA atmospheres was 16 to 4 hours at absolute humidity (AH) in the range 4.2 to 14.6 g m(-3), respectively. In a complex atmosphere at an initial AH of 9.6 g m(-3) the apparent half-life of ICA was 8 hours, as measured with the denuder method. Thus, thermally formed ICA is to be considered as a potential occupational hazard with regard to inhalation. The generation pattern of ICA formed during controlled gradient (100-540 °C) thermal decomposition of different polymers in the presence of air was examined by parallel PTR-MS and denuder air sampling. According to measurement by denuder sampling ICA was the dominant aliphatic isocyanate formed during the thermal decomposition of all polymers. The real-time measurements of the decomposed polymers revealed different ICA generation patterns, with initial appearance of thermally released ICA in the temperature range 200-260 °C. The PTR-MS ICA measurements was however affected by mass overlap from other decomposition products at m/z 44, illustrated by a [ICA]Denuder/[ICA]PTR-MS ratio ranging from 0.04 to 0.90. These findings limits the potential use of PTR-MS for real time measurements of thermally released ICA in field, suggesting parallel sampling with short-term sequential off-line methodology.

  7. Assessment of the ABC/2 Method of Epidural Hematoma Volume Measurement as Compared to Computer-Assisted Planimetric Analysis.

    Science.gov (United States)

    Hu, Ting-Ting; Yan, Ling; Yan, Peng-Fei; Wang, Xuan; Yue, Ge-Fen

    2016-01-01

    Epidural hematoma volume (EDHV) is an independent predictor of prognosis in patients with epidural hematoma (EDH) and plays a central role in treatment decision making. This study's objective was to determine the accuracy and reliability of the widely used volume measurement method ABC/2 in estimating EDHV by comparing it to the computer-assisted planimetric method. A data set of computerized tomography (CT) scans of 35 patients with EDH was evaluated to determine the accuracy of ABC/2 method, using computer-assisted planimetric technique to establish the reference criterion of EDHV for each patient. Another data set was constructed by randomly selecting 5 patients then replicating each case twice to yield 15 patients. Intra- and interobserver reliability were evaluated by asking four observers to independently estimate EDHV for the latter data set using the ABC/2 method. Estimation of EDHV using the ABC/2 method showed high intra- and interobserver reliability (intra-class correlation coefficient = .99). These estimates were closely correlated with planimetric measures (r = .99). But the ABC/2 method generally overestimated EDHV, especially in the nonellipsoid-like group. The difference between the ABC/2 measures and planimetric measures was statistically significant (p ABC/2 method could be used for EDHV measurement, which would contribute to treatment decision making as well as clinical outcome prediction. However, clinicians should be aware that the ABC/2 method results in a general volume overestimation. Future studies focusing on justification of the technique to improve its accuracy would be of practical value. © The Author(s) 2015.

  8. Response and recovery measures for two floods in north China during the nineteenth century: a comparative study.

    Science.gov (United States)

    Ye, Yu; Fang, Xiuqi; Li, Fan

    2016-01-01

    The process of human response to natural disasters and its mechanisms as revealed by historical events still has a broad significance for modern society. This study analyzed the disaster relief process and the social response for two floods in China: the Yongding River flood in 1801 and the Yellow River flood in 1841. These two floods reflect the different response processes between the national and provincial capitals during a stage of climate cooling and social transition in the Qing dynasty. Applying methods of historical documents analysis and qualitatively comparative analysis to the materials such as Relief Chronicles Authorized by the Emperor in XinYou and Flood Description in Bian Liang , it shows that: (1) In 1801, the central government took on a lead position, from flood surveying to relief processes. However, local government and gentries played an important role in 1841. (2) In 1801, the government successfully undertook a series of relief measures addressing production, housing, food prices, taxes, and water conservancy and administration. In 1841, the response measures were relatively simple, focusing mainly on providing shelter and food for victims. (3) The government carried out long-term disaster prevention measures such as dredging channels after the flood in 1801. In 1841, however, the efforts were focused mainly on emergency rescue. (4) Refugees in the 1801 flood were effectively managed by a centralized authority. In 1841, regulation of the flooding was delayed by corruption and conflicts between officers, leading to an expansion of the disaster's impact. Above results have led to the conclusion that disaster relief systems and response measures had a significant effect on the consequences of those floods. Various flood relief measures and natural disasters management regimes have implications for contemporary flood hazard mitigation.

  9. Highly Sensitive Measurements of the Dark Current of Superconducting Cavities for TESLA Using a SQUID Based Cryogenic Current Comparator

    CERN Document Server

    Vodel, W; Nietzsche, S

    2004-01-01

    This contribution presents a Cryogenic Current Comparator (CCC) as an excellent tool for detecting dark currents generated, e.g. by superconducting cavities for the upcoming TESLA project (X-FEL) at DESY. To achieve the maximum possible energy the gradient of the superconducting RF cavities should be pushed close to the physical limit of 50 MV/m. The undesired field emission of electrons (so-called dark current) of the superconducting RF cavities at strong fields may limit the maximum gradient. The absolute measurement of the dark current in correlation with the gradient will give a proper value to compare and classify the cavities. The main component of the CCC is a highly sensitive LTS-DC SQUID system which is able to measure extremely low magnetic fields, e.g. caused by the dark current. For this reason the input coil of the SQUID is connected across a special designed toroidal niobium pick-up coil for the passing electron beam. A noise limited current resolution of nearly 2 pA/√(Hz) with a measu...

  10. Comparative Analysis of Satellite Measurements Calculation Results Using the Postprocessing Services: Asg-Eupos (Poland), Apps (USA) and CSRS (Canada)

    Science.gov (United States)

    Mika, Monika; Kudach, Jakub

    2014-06-01

    The publication has a cognitive research character. It presents a comparative analysis of free Internet services in Poland and abroad, used to adjust the data obtained using satellite measurement techniques. The main aim of this work is to describe and compare free tools for satellite data processing and to examine them for possible use in the surveying works in Poland. Among the many European and global services three of them dedicated to satellite measurements were selected: ASG-EUPOS (Poland), APPS (USA) and CSRS (Canada). The publication contains the results of calculations using these systems. Calculations were based on RINEX files obtained via postprocessing service (ASG-EUPOS network) POZGEO D for 12 reference stations in the South Poland. In order to examine differences in results between the ASG-EUPOS, APPS and CSRS the transformation points coordinate to a single coordinate system ETRF 2000 (in force in Poland) was made. Studies have shown the possibility of the calculation in Poland (in postprocessing mode) using the analyzed applications with global coverage.

  11. Making limb and nadir measurements comparable: A common volume study of PMC brightness observed by Odin OSIRIS and AIM CIPS

    Science.gov (United States)

    Benze, Susanne; Gumbel, Jörg; Randall, Cora E.; Karlsson, Bodil; Hultgren, Kristoffer; Lumpe, Jerry D.; Baumgarten, Gerd

    2018-01-01

    Combining limb and nadir satellite observations of Polar Mesospheric Clouds (PMCs) has long been recognized as problematic due to differences in observation geometry, scattering conditions, and retrieval approaches. This study offers a method of comparing PMC brightness observations from the nadir-viewing Aeronomy of Ice in the Mesosphere (AIM) Cloud Imaging and Particle Size (CIPS) instrument and the limb-viewing Odin Optical Spectrograph and InfraRed Imaging System (OSIRIS). OSIRIS and CIPS measurements are made comparable by defining a common volume for overlapping OSIRIS and CIPS observations for two northern hemisphere (NH) PMC seasons: NH08 and NH09. We define a scattering intensity quantity that is suitable for either nadir or limb observations and for different scattering conditions. A known CIPS bias is applied, differences in instrument sensitivity are analyzed and taken into account, and effects of cloud inhomogeneity and common volume definition on the comparison are discussed. Not accounting for instrument sensitivity differences or inhomogeneities in the PMC field, the mean relative difference in cloud brightness (CIPS - OSIRIS) is -102 ± 55%. The differences are largest for coincidences with very inhomogeneous clouds that are dominated by pixels that CIPS reports as non-cloud points. Removing these coincidences, the mean relative difference in cloud brightness reduces to -6 ± 14%. The correlation coefficient between the CIPS and OSIRIS measurements of PMC brightness variations in space and time is remarkably high, at 0.94. Overall, the comparison shows excellent agreement despite different retrieval approaches and observation geometries.

  12. Wrist blood pressure-measuring devices: a comparative study of accuracy with a standard auscultatory method using a mercury manometer.

    Science.gov (United States)

    Altunkan, Sekip; Yildiz, Sevil; Azer, Sabir

    2002-10-01

    In this study, we compared two wrist blood pressure-measuring devices, the Omron RX and the Nissei WS-310, against a mercury manometer. A total of 152 subjects attending an out-patient hypertensive clinic were recruited from a randomized blood pressure survey, 87 patients (mean 44.4 +/- 14.5 years of age) being selected according to the Association for the Advancement of Medical Instrumentation/British Hypertension Society standards. Device validation was assessed through the use of sequential same-arm readings compared with readings taken using a mercury sphygmomanometer by the two trained observers. There were no differences between the observers and the monitors for diastolic readings (2.8 +/- 4.8 mmHg for the Omron and 4.2 +/- 6.4 mmHg for the Nissei) according to the Association for the Advancement of Medical Instrumentation standards. The largest standard deviations -- 8.3 mmHg for the Omron and 8.8 mmHg for the Nissei, respectively -- were seen for systolic readings recorded by the observers and the monitors. According to the British Hypertension Society standards, the Omron achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. The Nissei monitor achieved an A grade for diastolic readings and a B grade for systolic readings within 5 and 10 mmHg. Patients found the wrist oscillometric devices that we tested to be comfortable and easy to use. These devices are appropriate for measuring diastolic blood pressure according to the standards, but the reliability of both devices decreased when measuring systolic blood pressure.

  13. Does Objective Quality of Physicians Correlate with Patient Satisfaction Measured by Hospital Compare Metrics in New York State?

    Science.gov (United States)

    Bekelis, Kimon; Missios, Symeon; MacKenzie, Todd A; O'Shaughnessy, Patrick M

    2017-07-01

    It is unclear whether publicly reported benchmarks correlate with quality of physicians and institutions. We investigated the association of patient satisfaction measures from a public reporting platform with performance of neurosurgeons in New York State. This cohort study comprised patients undergoing neurosurgical operations from 2009 to 2013 who were registered in the Statewide Planning and Research Cooperative System database. The cohort was merged with publicly available data from the Centers for Medicare and Medicaid Services Hospital Compare website. Propensity-adjusted regression analysis was used to investigate the association of patient satisfaction metrics with neurosurgeon quality, as measured by the neurosurgeon's individual rate of mortality and average length of stay. During the study period, 166,365 patients underwent neurosurgical procedures. Using propensity-adjusted multivariable regression analysis, we demonstrated that undergoing neurosurgical operations in hospitals with a greater percentage of patient-assigned "high" scores was associated with higher chance of being treated by a physician with superior performance in terms of mortality (odds ratio 1.90, 95% confidence interval 1.86-1.95), and a higher chance of being treated by a physician with superior performance in terms of length of stay (odds ratio 1.24, 95% confidence interval 1.21-1.27). Similar associations were identified for hospitals with a higher percentage of patients who claimed they would recommend these institutions to others. Merging a comprehensive all-payer cohort of neurosurgery patients in New York State with data from the Hospital Compare website, we observed an association of superior hospital-level patient satisfaction measures with objective performance of individual neurosurgeons in the corresponding hospitals. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Validation of ultrasonographic muscle thickness measurements as compared to the gold standard of computed tomography in dogs

    Directory of Open Access Journals (Sweden)

    Lindsey E. Bullen

    2017-01-01

    Full Text Available Objective The objective was to quantitatively evaluate the validity of ultrasonographic (US muscle measurements as compared to the gold standard of computed tomography (CT in the canine. Design This was a prospective study. Population Twenty-five, client-owned dogs scheduled for CT as part of a diagnostic work-up for the management of their primary disease process were included. Materials and Methods Specific appendicular (cubital flexors and extensors, coxofemoral flexors and extensors and axial (temporalis, supraspinatus, infraspinatus, lumbar epaxials muscle groups were selected for quantitative measure based on CT planning and patient position. Prior to CT scan, the skin over the muscle sites was shaved and marked with a permanent marker. Patient body position was determined based on the patient’s CT plan; positioning was consistent between CT and US imaging. To ensure identical imaging position for both CT and US measurements, radio-opaque fiducial markers were placed directly over the skin marks once the dog was positioned. Quantitative measurements (cm for both lean muscle mass (LMM and subcutaneous adipose (SQA were recorded. Statistical comparisons between CT and US values were done separately for each site and type. Results Muscle groups and associated SQA measured by US and CT were not statistically different based on an adjusted p-value using Bonferroni’s correction (p 0.897 for LLM and >0.8289 for SQA. Conclusions Ultrasound imaging of selected appendicular and axial muscle groups in dogs can provide comparable assessment of muscle thickness to the current gold standard, CT. In consideration of both statistical reliability to CT and cage-side accessibility, the temporalis, supraspinatus, infraspinatus, and lumbar epaxial LMM sites are considered the most useful targets for US LMM assessment in the canine. Our findings support the potential utility of US as a clinical tool in veterinary medicine to assess LMM status in patients

  15. Diffusion tensor imaging measures of white matter compared to myelin basic protein immunofluorescence in tissue cleared intact brains

    Directory of Open Access Journals (Sweden)

    Eric H. Chang

    2017-02-01

    Full Text Available We provide datasets from combined ex vivo diffusion tensor imaging (DTI and Clear Lipid-exchanged, Anatomically Rigid, Imaging/immunostaining compatible, Tissue hYdrogel (CLARITY performed on intact mouse brains. DTI-derived measures of fractional anisotropy (FA, radial diffusivity (RD, and axial diffusivity (AD were compared to antibody-based labeling of myelin basic protein (MBP, as measured by fluorescence microscopy. We used a customized CLARITY hydrogel solution to facilitate whole brain tissue clearing and subsequent immunolabeling. We describe how CLARITY was made compatible with magnetic resonance imaging with the intention of facilitating future multimodal imaging studies that may combine noninvasive imaging with 3D immunohistochemistry. These data and methods are related to the accompanying research article entitled, ‘The role of myelination in measures of white matter integrity: Combination of diffusion tensor imaging and two-photon microscopy of CLARITY intact brains’ (E.H. Chang, M. Argyelan, M. Aggarwal, T-S. Chandon, K.H. Karlsgodt, S. Mori, A.K. Malhotra, 2016 [1].

  16. Comparative measurements of plasma potential with ball-pen and Langmuir probe in low-temperature magnetized plasma

    Science.gov (United States)

    Zanáška, M.; Adámek, J.; Peterka, M.; Kudrna, P.; Tichý, M.

    2015-03-01

    The ball-pen probe (BPP) is used for direct plasma potential measurements in magnetized plasma. The probe can adjust the ratio of the electron and ion saturation currents Isat-/Isat+ to be close to one and therefore its I-V characteristic becomes nearly symmetric. If this is achieved, the floating potential of the BPP is close to the plasma potential. Because of its rather simple construction, it offers an attractive probe for measurements in magnetized plasma. Comparative measurements of plasma potential by BPPs of different dimensions as well as one Langmuir probe (LP) in an argon discharge plasma of a cylindrical magnetron were performed at various experimental conditions. An additional comparison by an emissive probe was also performed. All these types of probes provide similar values of plasma potential in a wide range of plasma parameters. Our results for three different BPP dimensions indicate that the BPP can be operated in a cylindrical magnetron DC argon discharge if the value of the ratio of the magnetic field and neutral gas pressure, B/p, is greater than approximately 10 mT/Pa.

  17. A comparative study of sheath potential profile measurements with laser-heated and current-heated emissive probes

    Science.gov (United States)

    Kella, Vara Prasad; Mehta, Payal; Sarma, A.; Ghosh, J.; Chattopadhyay, P. K.

    2016-04-01

    Emissive Langmuir probe is one of the most efficient diagnostic tools available for plasma potential measurements. Extensive studies have been carried out in designing different kinds of conventional (electrically heated) emissive probes (CEPs) to estimate the plasma potential. Laser heated emissive probe (LHEP) has been developed with certain advantages over the conventional probes such as low evaporation rate of the probe material, high lifetime, and high emission levels. Most importantly, the LHEP uses laser to heat the probe-tip and does not require electric current to heat the probe-tip like in CEP. The heating current in CEP substantially affects the plasma potential measurements, especially in the regions of plasma where high electric and magnetic field gradients are present. In this paper, we studied the plasma potential structures in sheath-presheath region using both LHEP and CEP in an unmagnetized dc-filament discharge plasma. Measurements of sheath spatial potential profile using laser heated emissive probe are compared with those obtained using conventional emissive probe.

  18. Assignment of resonances in dissociative recombination of HD{sup +} ions: High-resolution measurements compared with accurate computations

    Energy Technology Data Exchange (ETDEWEB)

    Waffeu Tamo, F. O. [Laboratoire Ondes et Milieux Complexes FRE-3102 CNRS and Universite du Havre, 25, rue Philippe Lebon, BP 540, F-76058 Le Havre (France); Centre for Atomic, Molecular Physics and Quantum Optics (CEPAMOQ), University of Douala, P.O. Box 8580, Douala (Cameroon); Laboratoire d' Etude du Rayonnement et de la Matiere en Astrophysique, Observatoire de Paris, F-91295 Meudon Cedex (France); Buhr, H.; Schwalm, D. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Department of Particle Physics, Weizmann Institute of Science, P.O. Box 26, 76100 Rehovot (Israel); Motapon, O. [LPF, UFD Physique et Sciences de l' Ingenieur, University of Douala, P.O. Box 24157, Douala (Cameroon); Altevogt, S.; Andrianarijaona, V. M.; Grieser, M.; Lammich, L.; Lestinsky, M.; Motsch, M.; Novotny, S.; Orlov, D. A.; Pedersen, H. B.; Sprenger, F.; Weigel, U.; Wolf, A. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Nevo, I. [Department of Particle Physics, Weizmann Institute of Science, P.O. Box 26, 76100 Rehovot (Israel); Urbain, X. [Institute of Condensed Matter and Nanosciences, Universite catholique de Louvain, chemin du cyclotron 2, B-1348 Louvain-la Neuve (Belgium); Schneider, I. F. [Laboratoire Ondes et Milieux Complexes FRE-3102 CNRS and Universite du Havre, 25, rue Philippe Lebon, BP 540, F-76058 Le Havre (France)

    2011-08-15

    The collision-energy resolved rate coefficient for dissociative recombination of HD{sup +} ions in the vibrational ground state is measured using the photocathode electron target at the heavy-ion storage ring TSR. Rydberg resonances associated with rovibrational excitation of the HD{sup +} core are scanned as a function of the electron collision energy with an instrumental broadening below 1 meV in the low-energy limit. The measurement is compared to calculations using multichannel quantum defect theory, accounting for rotational structure and interactions and considering the six lowest rotational energy levels as initial ionic states. Using thermal-equilibrium-level populations at 300 K to approximate the experimental conditions, close correspondence between calculated and measured structures is found up to the first vibrational excitation threshold of the cations near 0.24 eV. Detailed assignments, including naturally broadened and overlapping Rydberg resonances, are performed for all structures up to 0.024 eV. Resonances from purely rotational excitation of the ion core are found to have similar strengths as those involving vibrational excitation. A dominant low-energy resonance is assigned to contributions from excited rotational states only. The results indicate strong modifications in the energy dependence of the dissociative recombination rate coefficient through the rotational excitation of the parent ions, and underline the need for studies with rotationally cold species to obtain results reflecting low-temperature ionized media.

  19. Comparing the reliability and accuracy of clinical measurements using plaster model and the digital model system based on crowding severity.

    Science.gov (United States)

    Liang, Yu-Ming; Rutchakitprakarn, Lalita; Kuang, Shou-Hsin; Wu, Tzu-Ying

    2018-01-25

    This study aims to clarify whether 3Shape™ digital model system could be applied in orthodontic diagnostic analysis with certainty, especially under different crowding condition. Reliability, accuracy and efficiency of 3Shape™ digital model system were assessed by comparing them with traditional plaster cast. 29 plaster casts with permanent dentition were transformed into digital models by 3Shape™ D800 scanner. All 29 models were categorized into mild-crowding (arch length discrepancy 3 mm and 8 mm). Fourteen linear measurements were made manually using a digital caliper on plaster casts and virtually using the 3Shape™ Ortho Analyzer software by two examiners. Intra-class Correlation Coefficient (ICC) was used to evaluate intra-examiner reliability, inter-examiner reliability and reliability between two model systems. Paired t test was used to evaluate accuracy between two model systems. Kruskal-Wallis test followed by Mann-Whitney U test was used to evaluate the measurement differences between 3 groups in two model systems. Both intra-examiner and inter-examiner reliability were generally excellent for all measurements made on 3Shape™ digital model and plaster cast (ICC: 0.752-0.993). Reliability between different model systems was also excellent (ICC: 0.897-0.998). Half of the accuracy test showed statistically significant differences (p systems, the mandibular required space showed significant difference (p = 0.012) between mild crowding group (0.27 + 0.01 mm) and severe crowding group (0.20 + 0.09 mm). However, the differences were less than 0.5 mm and would not affect clinical decision. Using 3Shape™ digital model system instead of plaster casts for orthodontic diagnostic measurements is clinically acceptable. Copyright © 2018. Published by Elsevier Taiwan LLC.

  20. Incidence of childhood pneumonia: facility-based surveillance estimate compared to measured incidence in a South African birth cohort study

    Science.gov (United States)

    le Roux, David M; Myer, Landon; Nicol, Mark P; Zar, Heather J

    2015-01-01

    Background Pneumonia is the leading cause of childhood mortality and a major contributor to childhood morbidity, but accurate measurement of pneumonia incidence is challenging. We compared pneumonia incidence using a facility-based surveillance system to estimates from a cohort study conducted contemporaneously in the same community in Cape Town, South Africa. Methods A surveillance system was developed in six public sector primary care clinics and in a regional referral hospital, to detect childhood pneumonia cases. Nurses recorded all children presenting to facilities who met WHO case definitions of pneumonia, and hospital records were reviewed. Estimates of pneumonia incidence and severity were compared with incidence rates based on active surveillance in the Drakenstein Child Health Study. Results From June 2012 until September 2013, the surveillance system detected 306 pneumonia episodes in children under 1 year of age, an incidence of 0.20 episodes/child-year (e/cy) (95% CI 0.17 to 0.22 e/cy). The incidence in the cohort study from the same period was 0.27 e/cy (95% CI 0.23 to 0.32 e/cy). Pneumonia incidence in the surveillance system was almost 30% lower than in the birth cohort; incidence rate ratio 0.72 (95% CI 0.58 to 0.89). In the surveillance system, 18% were severe pneumonia cases, compared to 23% in the birth cohort, rate ratio 0.81 (95% CI 0.55 to 1.18). Conclusions In this setting, facility-based pneumonia surveillance detected fewer cases of pneumonia, and fewer severe cases, compared to the corresponding cohort study. Facility pneumonia surveillance using data collected by local healthcare workers provides a useful estimate of the epidemiology of childhood pneumonia but may underestimate incidence and severity. PMID:26685027

  1. Incidence of childhood pneumonia: facility-based surveillance estimate compared to measured incidence in a South African birth cohort study.

    Science.gov (United States)

    le Roux, David M; Myer, Landon; Nicol, Mark P; Zar, Heather J

    2015-12-18

    Pneumonia is the leading cause of childhood mortality and a major contributor to childhood morbidity, but accurate measurement of pneumonia incidence is challenging. We compared pneumonia incidence using a facility-based surveillance system to estimates from a cohort study conducted contemporaneously in the same community in Cape Town, South Africa. A surveillance system was developed in six public sector primary care clinics and in a regional referral hospital, to detect childhood pneumonia cases. Nurses recorded all children presenting to facilities who met WHO case definitions of pneumonia, and hospital records were reviewed. Estimates of pneumonia incidence and severity were compared with incidence rates based on active surveillance in the Drakenstein Child Health Study. From June 2012 until September 2013, the surveillance system detected 306 pneumonia episodes in children under 1 year of age, an incidence of 0.20 episodes/child-year (e/cy) (95% CI 0.17 to 0.22 e/cy). The incidence in the cohort study from the same period was 0.27 e/cy (95% CI 0.23 to 0.32 e/cy). Pneumonia incidence in the surveillance system was almost 30% lower than in the birth cohort; incidence rate ratio 0.72 (95% CI 0.58 to 0.89). In the surveillance system, 18% were severe pneumonia cases, compared to 23% in the birth cohort, rate ratio 0.81 (95% CI 0.55 to 1.18). In this setting, facility-based pneumonia surveillance detected fewer cases of pneumonia, and fewer severe cases, compared to the corresponding cohort study. Facility pneumonia surveillance using data collected by local healthcare workers provides a useful estimate of the epidemiology of childhood pneumonia but may underestimate incidence and severity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  2. Experimental analysis of ultrasonic signals in air-water vertical upward for void fraction measurement using neural networks; Analise experimental dos sinais ultra-sonicos em escoamentos verticais bifasicos para medicao da fracao de vazios atraves de redes neurais

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Milton Y.; Massignan, Joao P.D.; Daciuk, Rafael J.; Neves Junior, Flavio; Arruda, Lucia V.R. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2008-07-01

    Rheology of emulsion mixtures and void fraction measurements of multiphase flows requires proper instrumentation. Sometimes it is not possible to install this instrumentation inside the pipe or view the flow. Ultrasound technology has characteristics compatible with the requirements of the oil industry. It can assist the production of heavy oil. This study provides important information for an analysis of the feasibility of developing non-intrusive equipment. These probes can be used for measurement of multiphase void fraction and detect the flow pattern using ultrasound. Experiments using simulated upward air-water vertical two-phase flow show that there is a correlation between the acoustic attenuation and the concentration of the gas phase. Experimental data were obtained through the prototype developed for ultrasonic data acquisition. This information was processed and used as input parameters for a neural network classifier. Void fractions ({proportional_to}) were analyzed between 0% - 16%, in increments of 1%. The maximum error of the neural network for the classification of the flow pattern was 6%. (author)

  3. In-air and underwater hearing in the great cormorant (Phalacrocorax carbo sinensis)

    DEFF Research Database (Denmark)

    Johansen, Sasia; Larsen, Ole Næsbye; Christensen-Dalsgaard, Jakob

    2016-01-01

    Hearing thresholds of a great cormorant (Phalacrocorax carbo) were measured in air and under water using psychophysics. The lowest thresholds were at 2 kHz (45 dB re 20 μPa root-mean-square [rms] in air and 79 dB re 1 μPa rms in water). Auditory brainstem response measurements on one anesthetized...

  4. A comparative study of 19-iodocholesterol-''125I 3-acetate and Na''125I in liquid scintillation measurements

    International Nuclear Information System (INIS)

    Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J.M.; Grau Carles, A.

    1994-01-01

    A comparative study of performance of 19-iodocholesterol-''125I 3-acetate and sodium iodine samples labelled with ''125 I is presented for liquid scintillation counting measurements. Quench effect, count rate stability and spectral evolution of samples have been followed for several weeks in Toluene, Hisafe II, Instagel, Dioxane-naphthalene and Toluene-alcohol scintillators. Organic samples have negligible quench effect in the interval of I''-concentration of 0-90 ug and inorganic samples only show a very small variation, lower than 12%, for Dioxane-naphthalene, in the same range of concentration. Satisfactory stability is obtained in general for both, organic and inorganic samples, but small counting losses, 0.03% for 19-iodocholesterol-''125I 3-acetate samples in Toluene-alcohol and 0.04% for Na''125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs

  5. A comparative study of 19-iodo cholesterol-125I 3-acetate and Na 125I in liquid scintillation measurements

    International Nuclear Information System (INIS)

    Rodriguez Barquero, L.; Grau Malonda, A.; Los Arcos Merino, J. M.; Grau Carles, A.

    1994-01-01

    A comparative study of performance of 19-iodo cholesterol 1 25I 3-acetate and sodium iodide samples labeled with 125I is presented for liquid scintillation counting measurements. Quench effect, count rate stability and spectral evolution of samples have been followed for several weeks in Toluene, Hisafe II, Instagel, Dioxane-naphthalene and Toluene-alcohol scintillators. Organic samples have negligible quench effect in the interval of I concentration of 0-90 μg and inorganic samples only show a very small variation, lower than 12%, for Dioxane-naphthalene, in the same range of concentration. Satisfactory stability is obtained in general for both, organic and inorganic samples, but small counting losses, 0.03% for 19-iodocholesterol 1 I 3-acetate samples in Tolue ne-alcohol and 0 .04% for Na 125I samples in Dioxane-naphthalene and Toluene-alcohol, have been reported. (Author) 8 refs

  6. Harmonic models of a back-to-back converter in large offshore wind farms compared with measurement data

    DEFF Research Database (Denmark)

    Kocewiak, Lukasz Hubert; Hjerrild, Jesper; Bak, Claus Leth

    2009-01-01

    The offshore wind farm with installed back-to-back power converter in wind turbines is studied. As an example the Burbo Bank offshore wind farm with Siemens Wind Power wind turbines is taken into consideration. The wind farm is simulated in DIgSILENT Power Factory software in order to determine a...... results are compared with measurement data from the Burbo Bank offshore wind farm. The delimitations of both power converter models with referent to harmonic analysis are shown in this paper....... and assess harmonic emission in the point of common coupling. Different modelling methods of power electronic devices installed in wind turbines are presented. Harmonic load flow analysis and impedance frequency characteristics calculation are conducted to present differences between the models. Simulation...

  7. Comparative measurement of the efficiency of catalytic after-burning devices on a heavy-duty diesel engine

    Energy Technology Data Exchange (ETDEWEB)

    Pattas, K.N.; Kyriakis, N.A.; Samaras, Z.C.; Aidarinis, J.K.

    1984-01-01

    The effect of three oxidation catalysts (Honeycat DEP 290, Engelhard PTX 623, Herapur 20L) and one catalytic trap oxidizer (Johnson Matthey JM 13/II) on the emissions of a RABA (M.A.N. Licensed) heavy-duty diesel engine has been comparatively studied. Tests were conducted according to EPA 13 mode test to measure CO, total HC, NO/sub x/ and total particulate matter emitted by the engine with and without devices. The test results were also correlated to the total emissions of the Athenian buses through new weighing factors of an ''Athenian 13 mode test''. The engine tests for all four devices resulted in: (1) considerable reduction of the engine's CO and total HC emissions - being already low (2) practically no difference in NO/sub x/ emissions and (3) increase of the total particulate emissions at high load modes.

  8. Measuring international electricity integration: a comparative study of the power systems under the Nordic Council, MERCOSUR, and NAFTA

    Energy Technology Data Exchange (ETDEWEB)

    Pineau, P.-O. E-mail: ppineau@uvic.ca; Hira, Anil E-mail: ahira@sfu.ca; Froschauer, Karl E-mail: froschau@sfu.ca

    2004-09-01

    Many regions of the world feel the pressure to interconnect electric power systems internationally. Regional integrations of the electricity sector have become part of free trade and common market initiatives, though the steps individual national jurisdictions take towards developing integrated systems vary. In this article, we review three regions concerned with common market initiatives and at different stages of integration processes that involve infrastructural, regulatory, and commercial decisions. First, we examine the North European countries in the Nordic Council, then countries in the Southern Cone of South America in MERCOSUR, and finally Mexico, the United States and Canada, linked under NAFTA. This comparative study highlights the potential, but also the many hurdles, that electricity sector integrations face. The study suggests a framework for measuring the level of electricity sector integration that could be applied to other regions.

  9. Measuring international electricity integration: a comparative study of the power systems under the Nordic Council, MERCOSUR, and NAFTA

    International Nuclear Information System (INIS)

    Pineau, P.-O.; Hira, Anil; Froschauer, Karl

    2004-01-01

    Many regions of the world feel the pressure to interconnect electric power systems internationally. Regional integrations of the electricity sector have become part of free trade and common market initiatives, though the steps individual national jurisdictions take towards developing integrated systems vary. In this article, we review three regions concerned with common market initiatives and at different stages of integration processes that involve infrastructural, regulatory, and commercial decisions. First, we examine the North European countries in the Nordic Council, then countries in the Southern Cone of South America in MERCOSUR, and finally Mexico, the United States and Canada, linked under NAFTA. This comparative study highlights the potential, but also the many hurdles, that electricity sector integrations face. The study suggests a framework for measuring the level of electricity sector integration that could be applied to other regions

  10. Detailed characterization of a Comparative Reactivity Method (CRM) instrument for ambient OH reactivity measurements: experiments vs. modeling

    Science.gov (United States)

    Michoud, Vincent; Locoge, Nadine; Dusanter, Sébastien

    2015-04-01

    The Hydroxyl radical (OH) is the main daytime oxidant in the troposphere, leading to the oxidation of Volatile Organic Compounds (VOCs) and the formation of harmful pollutants such as ozone (O3) and Secondary Organic Aerosols (SOA). While OH plays a key role in tropospheric chemistry, recent studies have highlighted that there are still uncertainties associated with the OH budget, i.e the identification of sources and sinks and the quantification of production and loss rates of this radical. It has been demonstrated that ambient measurements of the total OH loss rate (also called total OH reactivity) can be used to identify and reduce these uncertainties. In this context, the Comparative Reactivity Method (CRM), developed by Sinha et al. (ACP, 2008), is a promising technique to measure total OH reactivity in ambient air and has already been used during several field campaigns. This technique relies on monitoring competitive reactions of OH with ambient trace gases and a reference compound (pyrrole) in a sampling reactor to derive ambient OH reactivity. However, this technique requires a complex data processing chain that has yet to be carefully investigated in the laboratory. In this study, we present a detailed characterization of a CRM instrument developed at Mines Douai, France. Experiments have been performed to investigate the dependence of the CRM response on humidity, ambient NOx levels, and the pyrrole-to-OH ratio inside the sampling reactor. Box modelling of the chemistry occurring in the reactor has also been performed to assess our theoretical understanding of the CRM measurement. This work shows that the CRM response is sensitive to both humidity and NOx, which can be accounted for during data processing using parameterizations depending on the pyrrole-to-OH ratio. The agreement observed between laboratory studies and model results suggests a good understanding of the chemistry occurring in the sampling reactor and gives confidence in the CRM

  11. Comparative measurements of growth rings in trees using a microscopic method and digital X-ray density images

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Mary Lucia da [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Quimica]. E-mail: maryls@terra.com.br; Wagener, Klaus [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica. Dept. de Quimica Analitica]. E-mail: mary_lucias@hotmail.com; Ferreira, Rubemar [Instituto de Radioprotecao e Dosimetria (IRD), Rio de Janeiro, RJ (Brazil)]. E-mail: rubemar@ird.gov.br

    2002-07-01

    As is well-known, the systematic analysis of the annual radial increase in the stem diameter of ring-forming trees gives quantitative information about varying climatic conditions in the past. These investigations became of high actual interest to verify present climatic changes. The traditional method for measuring ring widths in radially extracted tree samples is by microscopic observation, using an ABBE comparator. For documenting the recent climatic changes, as recorded in the changing sizes of the tree rings, dozens of trees have to be analyzed, and normally with four samples per each tree. This situation stimulated the interest in modern methods with fast data processing. However, to make use of them, needs also a fast way of recording the data. For the present purpose, this is the digital X-ray image showing the density differences in each ring has, resulting from 'early wood' and 'late wood' produced in different seasons of the year. To check the reliability of this new method, the same samples have also been measured with the microscopic method. It turned out that there are no systematic differences in the results, thus opening the way for much faster tree ring research. (author)

  12. Comparative measurements of growth rings in trees using a microscopic method and digital X-ray density images

    International Nuclear Information System (INIS)

    Silva, Mary Lucia da

    2002-01-01

    As is well-known, the systematic analysis of the annual radial increase in the stem diameter of ring-forming trees gives quantitative information about varying climatic conditions in the past. These investigations became of high actual interest to verify present climatic changes. The traditional method for measuring ring widths in radially extracted tree samples is by microscopic observation, using an ABBE comparator. For documenting the recent climatic changes, as recorded in the changing sizes of the tree rings, dozens of trees have to be analyzed, and normally with four samples per each tree. This situation stimulated the interest in modern methods with fast data processing. However, to make use of them, needs also a fast way of recording the data. For the present purpose, this is the digital X-ray image showing the density differences in each ring has, resulting from 'early wood' and 'late wood' produced in different seasons of the year. To check the reliability of this new method, the same samples have also been measured with the microscopic method. It turned out that there are no systematic differences in the results, thus opening the way for much faster tree ring research. (author)

  13. Thermographic skin temperature measurement compared with cold sensation in predicting the efficacy and distribution of epidural anesthesia.

    Science.gov (United States)

    Bruins, Arnoud A; Kistemaker, Kay R J; Boom, Annemieke; Klaessens, John H G M; Verdaasdonk, Rudolf M; Boer, Christa

    2018-04-01

    Due to the high rates of epidural failure (3-32%), novel techniques are required to objectively assess the successfulness of an epidural block. In this study we therefore investigated whether thermographic temperature measurements have a higher predictive value for a successful epidural block when compared to the cold sensation test as gold standard. Epidural anesthesia was induced in 61 patients undergoing elective abdominal, thoracic or orthopedic surgery. A thermographic picture was recorded at 5, 10 and 15 min following epidural anesthesia induction. After 15 min a cold sensation test was performed. Epidural anesthesia is associated with a decrease in skin temperature. Thermography predicts a successful epidural block with a sensitivity of 54% and a PPV of 92% and a specificity of 67% and a NPV of 17%. The cold sensation test shows a higher sensitivity and PPV than thermography (97 and 93%), but a lower specificity and NPV than thermography (25 and 50%). Thermographic temperature measurements can be used as an additional and objective method for the assessment of the effectiveness of an epidural block next to the cold sensation test, but have a low sensitivity and negative predictive value. The local decrease in temperature as observed in our study during epidural anesthesia is mainly attributed to a core-to-peripheral redistribution of body heat and vasodilation.

  14. Inadequacy of manual measurements compared to automated CT volumetry in assessment of treatment response of pulmonary metastases using RECIST criteria

    International Nuclear Information System (INIS)

    Marten, Katharina; Auer, Florian; Schmidt, Stefan; Rummeny, Ernst J.; Engelke, Christoph; Kohl, Gerhard

    2006-01-01

    The purpose of this study was to compare relative values of manual unidimensional measurements (MD) and automated volumetry (AV) for longitudinal treatment response assessment in patients with pulmonary metastases. Fifty consecutive patients with pulmonary metastases and repeat chest multidetector-row CT (median interval=2 months) were independently assessed by two radiologists for treatment response using Response Evaluation Criteria In Solid Tumours (RECIST). Statistics included relative measurement errors (RME), intra-/interobserver correlations, limits of agreement (95% LoA), and kappa. A total of 202 metastases (median volume=182.22 mm 3 ; range=3.16-5,195.13 mm 3 ) were evaluated. RMEs were significantly higher for MD than for AV (intraobserver RME=2.34-3.73% and 0.15-0.22% for MD and AV respectively; P 3 for AV. The interobserver 95% LoA were -1.46 to 1.92 mm for MD and -11.17 to 9.33 mm 3 for AV. There was total intra-/interobserver agreement on response using AV (κ=1). MD intra- and interobserver agreements were 0.73-0.84 and 0.77-0.80 respectively. Of the 200 MD response ratings, 28 (14/50 patients) were discordant. Agreement using MD dropped significantly from total remission to progressive disease (P<0.05). We therefore conclude that AV allows for better reproducibility of response evaluation in pulmonary metastases and should be preferred to MD in these patients. (orig.)

  15. Comparing a single case to a control group - Applying linear mixed effects models to repeated measures data.

    Science.gov (United States)

    Huber, Stefan; Klein, Elise; Moeller, Korbinian; Willmes, Klaus

    2015-10-01

    In neuropsychological research, single-cases are often compared with a small control sample. Crawford and colleagues developed inferential methods (i.e., the modified t-test) for such a research design. In the present article, we suggest an extension of the methods of Crawford and colleagues employing linear mixed models (LMM). We first show that a t-test for the significance of a dummy coded predictor variable in a linear regression is equivalent to the modified t-test of Crawford and colleagues. As an extension to this idea, we then generalized the modified t-test to repeated measures data by using LMMs to compare the performance difference in two conditions observed in a single participant to that of a small control group. The performance of LMMs regarding Type I error rates and statistical power were tested based on Monte-Carlo simulations. We found that starting with about 15-20 participants in the control sample Type I error rates were close to the nominal Type I error rate using the Satterthwaite approximation for the degrees of freedom. Moreover, statistical power was acceptable. Therefore, we conclude that LMMs can be applied successfully to statistically evaluate performance differences between a single-case and a control sample. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Clinical usefulness of serum free light chains measurement in patients with multiple myeloma: comparative analysis of two different tests

    Directory of Open Access Journals (Sweden)

    Tadeusz Kubicki

    2017-01-01

    Full Text Available Introduction: There are two commercially available tests for measurement of serum free light chains (sFLC in multiple myeloma (MM patients – Freelite and N Latex FLC. The aim of this study was to perform an assessment and direct comparison of the usefulness of the methods in routine clinical practice.Methods: 40 refractory/relapsed MM patients underwent routine disease activity assessment studies, along with sFLC analysis using both assays. Correlation and concordance between the tests and sensitivity of studied methods of sFLC assessment were established. Special attention was focused on sFLC results in patients finally evaluated after completing the treatment. Results: A weak correlation for the measurement of both κ [Passing–Bablok slope (PB = 0.7681] and λ chains [(PB = 1.542] was found. Using Bland–Altman plots, a bias of 0.0467 (κ and -0.2133 (λ between the measurements was documented. The concordance coefficient equaled 0.87 for κ, 0.62 for λ and 0.52 for κ/λ ratio. Ten patients had an abnormal Freelite assay κ/λ ratio and normal N Latex FLC κ/λ ratio. Three of these patients had negative serum protein electrophoresis results and fulfilled diagnostic criteria of stringent complete remission (sCR according to N Latex FLC (but not according to Freelite. When the κ/λ ratio obtained by both methods was compared to patients’ serum/urine protein electrophoresis and immunofixation results, sensitivity of Freelite and N Latex FLC was established to be 62.5% and 41%, respectively. Conclusions: There was no strong correlation or concordance between the two assays, and the sensitivity in terms of sFLC detection was different. This may cause problems when diagnosis of sCR is considered.

  17. Comparative study of regional cerebral blood flow values measured by IMP SPECT, 133Xe SPECT and Xe CT

    International Nuclear Information System (INIS)

    Matsuda, Masayuki; Lee, Hidehiko; Kuribayashi, Kousuke; Handa, Jyoji

    1996-01-01

    We measured the regional cerebral blood flow (rCBF) by N-isopropyl-p-[ 123 I] iodoamphetamine (IMP) SPECT using the recently proposed simplified method, and compared the values obtained with those determined by 133 Xe SPECT and Xe CT. A total of 10 patients with cerebrovascular disease was studied. In the region of the anterior cerebral artery of the non-lesion side, significantly lower values were obtained by Xe CT than by 133 Xe SPECT, whereas in the area of the middle cerebral artery, IMP SPECT recorded significantly higher values than the other two methods. In the territory of the posterior cerebral artery, IMP SPECT also recorded significantly higher values than the other methods, with the differences reaching 9. 3 ml/100g/min from 133 Xe SPECT and 12 ml/100g/min from Xe CT measurements. Similar res