WorldWideScience

Sample records for spot film measuring

  1. X-ray spot film device

    International Nuclear Information System (INIS)

    Pury, T.; Tsen, M.L.S.; Gray, F.L.; Stehr, R.E.; Konle, R.L.

    1981-01-01

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  2. Measuring microfocus focal spots using digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Fry, David A [Los Alamos National Laboratory

    2009-01-01

    Measurement of microfocus spot size can be important for several reasons: (1) Quality assurance during manufacture of microfocus tubes; (2) Tracking performance and stability of microfocus tubes; (3) Determining magnification (especially important for digital radiography where the native spatial resolution of the digital system is not adequate for the application); (4) Knowledge of unsharpness from the focal spot alone. The European Standard EN 12543-5 is based on a simple geometrical method of calculating focal spot size from unsharpness of high magnification film radiographs. When determining microfocus focal spot dimensions using unsharpness measurements both signal-to-noise (SNR) and magnification can be important. There is a maximum accuracy that is a function of SNR and therefore an optimal magnification. Greater than optimal magnification can be used but it will not increase accuracy.

  3. Laser Pyrometer For Spot Temperature Measurements

    Science.gov (United States)

    Elleman, D. D.; Allen, J. L.; Lee, M. C.

    1988-01-01

    Laser pyrometer makes temperature map by scanning measuring spot across target. Scanning laser pyrometer passively measures radiation emitted by scanned spot on target and calibrated by similar passive measurement on blackbody of known temperature. Laser beam turned on for active measurements of reflectances of target spot and reflectance standard. From measurements, temperature of target spot inferred. Pyrometer useful for non-contact measurement of temperature distributions in processing of materials.

  4. Initial research on the characterization methods of sparkle spots in optical thin films

    Science.gov (United States)

    Jiang, Jinhu; Gu, Wenhua

    2018-01-01

    In this article, we made a preliminary study on the main influencing factors of sparkle spots, put forward the concept of "sparklingness" to characterize the strength of sparkle spots, and proposed a standard measurement method for the sparklingness. We proposed to use 532 nm green laser pointer as the testing light source, let the light pass through the film and form a sparkle spots image at the receiving CCD or a piece of white paper. A standard image processing method was used to obtain an index number standing for the scattering status of the laser, which is defined as "sparklingness". In the experiment, we also analyzed the power dependence of sparklingness. With proper calibration, the measurement error of the sparklingness can be minimized, and it can be used as a physical quantity to describe the film quality as of the sparkle issue. This work can be a useful reference for further study of the sparkle issue in optical films.

  5. Nanotopographic characterization of spotted micro arrays on polyvinyl alcohol films by high-resolution long-range nanoprofiling.

    Science.gov (United States)

    Thete, Aniket R; Gross, G Alexander; Hausotte, Tino; Jäger, Gerd; Dorozhovets, Nataliya; Köhler, J Michael

    2009-01-01

    The nanopositioning and nanomeasuring machine was applied for the nanotopographic characterization of polymer micro spot arrays of fluorimetric chemochips. Chemochips are arrays of fluorescence dyes in a hydrogel matrix with different response behaviors of chemical components determination of chemical and physico-chemical properties of analytes by a pattern recognition approach. For the characterization and quality control of the spots, a nanometer resolution is needed over a scan range of several millimeters. This challenge could be met by use of a scanning probe sensor in connection with a laser interferometer controlled high-precision positioning and measuring device. This way, topographic scans with the resolution of atomic force microscope could be achieved over these demandingly large ranges. The technique was used in order to determine the quality of thin film micro spots made from fluorescence dye solutions on preformed polymer films and also tested for characterization of monomolecular films in the form of micro spots. The nanotopographic measurements reflect the strong influence of solvent/matrix interaction, wetting, swelling and material transport during the application of picoliter droplets in the spotting process. The measurement clarifies the reason for the formation of roughness in the nanometer range by nano-crystal formation in the upper part of polymer film and the rim formation of micro spots during solvent evaporation. The studies show the effect of application of different numbers of droplets in a dispensing series for spot formation and prove the high importance of polymer/solvent interaction for the quality of formed micro spots as well as for spot arrays of monomolecular films. Copyright (c) 2009 Wiley Periodicals, Inc.

  6. Dry spot growth criterion for isothermal liquid films on a horizontal substrate

    Science.gov (United States)

    Maltsev, L. I.; Podzharov, Yu. S.; Kabov, O. A.

    2017-05-01

    A criterion was elaborated for the phenomenon of dry spot evolution in isothermal liquid films on a horizontal substrate. The formulas are presented for gravity force and surface tension acting upon an element of the rim around the dry spot. The forces balance gives the evolution of initial dry spot: to expand or to contract.

  7. Spotting 2D atomic layers on aluminum nitride thin films.

    Science.gov (United States)

    Chandrasekar, Hareesh; Bharadwaj B, Krishna; Vaidyuala, Kranthi Kumar; Suran, Swathi; Bhat, Navakanta; Varma, Manoj; Srinivasan Raghavan

    2015-10-23

    Substrates for 2D materials are important for tailoring their fundamental properties and realizing device applications. Aluminum nitride (AIN) films on silicon are promising large-area substrates for such devices in view of their high surface phonon energies and reasonably large dielectric constants. In this paper epitaxial layers of AlN on 2″ Si wafers have been investigated as a necessary first step to realize devices from exfoliated or transferred atomic layers. Significant thickness dependent contrast enhancements are both predicted and observed for monolayers of graphene and MoS2 on AlN films as compared to the conventional SiO2 films on silicon, with calculated contrast values approaching 100% for graphene on AlN as compared to 8% for SiO2 at normal incidences. Quantitative estimates of experimentally measured contrast using reflectance spectroscopy show very good agreement with calculated values. Transistors of monolayer graphene on AlN films are demonstrated, indicating the feasibility of complete device fabrication on the identified layers.

  8. Laser Beam Caustic Measurement with Focal Spot Analyser

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Gong, Hui; Bagger, Claus

    2005-01-01

    In industrial applications of high power CO2-lasers the caustic characteristics of the laser beam have great effects on the performance of the lasers. A welldefined high intense focused spot is essential for reliable production results. This paper presents a focal spot analyser that is developed...... for measuring the beam profiles of focused high power CO2-lasers....

  9. Material influence on hot spot distribution in the nanoparticle heterodimer on film

    Science.gov (United States)

    Chen, Fang; Huang, Yingzhou; Wei, Hua; Wang, Shuxia; Zeng, Xiping; Cao, Wenbin; Wen, Weijia

    2018-04-01

    The metal nanoparticle aggregated on film, as an effective plasma enhancement pathway, has been widely used in various surface plasmon-related fields. In this study, the hot spots on the metal nanoparticle dimer composed of different materials (Agsbnd Au, Agsbnd Pd, and Agsbnd Cu) on metal (Au) film were investigated with finite element method. Based on the results, the hot spot distribution affected by the material can be confirmed by the electric field distribution of the metal nanoparticle dimer on the film. The aggregation effects of Au and Ag nanoparticles in Ausbnd Ag dimer system are not significant. However, for the Pdsbnd Ag dimer system, the hot spot aggregation effect is slightly larger than that of the Pd nanoparticle under the Ag nanoparticle. Besides, the non-uniform hot spots would bring about the light focusing phenomenon that the light intensity under Ag nanoparticle is almost 100 times greater than that under Cu nanoparticle in Agsbnd Cu dimer system. These results were further confirmed by the surface charge distribution, and analyzed based on the plasmonic hybridization theory. The data about the nanoparticle dimer on the dielectric (Si) film demonstrate the importance of induced image charges on the film surface in such a light focusing phenomenon. Our findings can enhance the understanding of the surface plasmon coupling in different materials, which may have great application prospects in surface plasmon-related fields, such as SERS, plasmonic enhanced solar cell, and plasmonic sensoring, etc.

  10. Thermal analysis of continuous and patterned multilayer films in the presence of a nanoscale hot spot

    Directory of Open Access Journals (Sweden)

    Jia-Yang Juang

    2016-10-01

    Full Text Available Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR, the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal barriers at the material layer interfaces crucially impact the temperature field hence play a key role in determining the hot spot geometry, transient response and power consumption. With a representative generic media model, we further explored the possibility of optimizing thermal performances by designing layers of heat sink and thermal barrier. The modeling approach demonstrates an effective way to characterize thermal behaviors of micro and nano-scale electronic devices with multilayer thin film structures. The insights into the thermal transport scheme will be critical for design and operations of such electronic devices.

  11. Thermal analysis of continuous and patterned multilayer films in the presence of a nanoscale hot spot

    Science.gov (United States)

    Juang, Jia-Yang; Zheng, Jinglin

    2016-10-01

    Thermal responses of multilayer films play essential roles in state-of-the-art electronic systems, such as photo/micro-electronic devices, data storage systems, and silicon-on-insulator transistors. In this paper, we focus on the thermal aspects of multilayer films in the presence of a nanoscale hot spot induced by near field laser heating. The problem is set up in the scenario of heat assisted magnetic recording (HAMR), the next-generation technology to overcome the data storage density limit imposed by superparamagnetism. We characterized thermal responses of both continuous and patterned multilayer media films using transient thermal modeling. We observed that material configurations, in particular, the thermal barriers at the material layer interfaces crucially impact the temperature field hence play a key role in determining the hot spot geometry, transient response and power consumption. With a representative generic media model, we further explored the possibility of optimizing thermal performances by designing layers of heat sink and thermal barrier. The modeling approach demonstrates an effective way to characterize thermal behaviors of micro and nano-scale electronic devices with multilayer thin film structures. The insights into the thermal transport scheme will be critical for design and operations of such electronic devices.

  12. Performance of an app measuring spot quality in dried blood spot sampling

    NARCIS (Netherlands)

    Veenhof, Herman

    2016-01-01

    Introduction: The Dried Blood Spot sampling (DBS) method gives patients and health care workers the opportunity for remote sampling using a drop of blood from a fingerprick on a sampling card which can be send to the laboratory by mail. Laboratory analysts frequently reject DBS samples because of

  13. Hot-Electron Intraband Luminescence from Single Hot Spots in Noble-Metal Nanoparticle Films

    Science.gov (United States)

    Haug, Tobias; Klemm, Philippe; Bange, Sebastian; Lupton, John M.

    2015-08-01

    Disordered noble-metal nanoparticle films exhibit highly localized and stable nonlinear light emission from subdiffraction regions upon illumination by near-infrared femtosecond pulses. Such hot spot emission spans a continuum in the visible and near-infrared spectral range. Strong plasmonic enhancement of light-matter interaction and the resulting complexity of experimental observations have prevented the development of a universal understanding of the origin of light emission. Here, we study the dependence of emission spectra on excitation irradiance and provide the most direct evidence yet that the continuum emission observed from both silver and gold nanoparticle aggregate surfaces is caused by recombination of hot electrons within the conduction band. The electron gas in the emitting particles, which is effectively decoupled from the lattice temperature for the duration of emission, reaches temperatures of several thousand Kelvin and acts as a subdiffraction incandescent light source on subpicosecond time scales.

  14. Measurements and comparison of focal spot sizes of two types of x-ray tubes installed in simulators

    International Nuclear Information System (INIS)

    Wen, C.; Sorell, G.; Hille, N.

    1996-01-01

    Full text: Measurements of the effective focal spot size of two types of X-ray tubes installed in radiotherapeutic simulators (TOSHIBA and VARIAN-Ximatron) are presented. As recommended in ACPSEM Quality Assurance Protocols for Diagnostic X-ray Equipment [Heggie and Petty, APESM, Vol.8 No.1 1985], the effective focal spot size of X-ray tube is vital in determining the maximum resolution of radiographic and fluoroscopic images. Hence, the quality of clinical performance of diagnostic equipment is depended to a large extent upon the accuracy in measuring and maintaining the focal spot size of the X-ray tube and regular QA program. In determining the shape and the dimension of the effective focal spot that is located within the X-ray tube and can not be measured directly, a method developed by Spiegler and Breckinridge [Spiegler and Breckinrige, Radiation Physics, Vol. 102 Mar. 1972] was used. By irradiating a lead star pattern which is placed in a divert X-ray beam between the tube and a negative film, a magnified radiographic image of the test pattern can be obtained from a standard X-ray film. The actual shape of the effective focus is determined by tracing the locus of the image intensity inversion of the radial pattern where that is occurring when only a certain condition of spatial variation from a central ray-line is met. Then, the dimension of the focal spot can be calculated. In this measurements, three different test patterns (Typ 9/1, 5 deg Vertex Angle 0.03 mm Pb, Typ 9-2 deg-360 0.05 mmPb and Typ 9 Teilung 2 deg 0.05 mm Pb) with same diameter of 45 mm are used. Results from a series measurements which were carried out repetitively under same working condition of both simulators indicate that the effective focal spots of these two tubes are of similar rectangular shape. However, the dimensions of the focal spots are about 1.297 X 0.848 mm for the TOSHIBA tube and 0.692 X 0.532 mm for the Ximatron tube. The orientation of the focal spot for TOSHIBA tube is

  15. Measurements of acoustic properties for thin films

    International Nuclear Information System (INIS)

    Kushibiki, J.; Maehara, H.; Chubachi, N.

    1982-01-01

    A measurement method for determining thin-film acoustic properties, such as characteristic acoustic impedance, sound velocity, density, and stiffness constant, is developed with a simple measurement principle and high measurement accuracy. The acoustic properties are determined from a maximum reflection loss and a center frequency obtained through a frequency response of the reflection loss for an acoustic transmission line composed of a sapphire/film/water system by using the acoustic pulse mode measurement system in the UHF range. The determination of the acoustic properties is demonstrated for sputtered fused quartz film, low-expansion borosilicate glass films, and chalcogenide glass films of evaporated As 2 S 3 and As 2 Se 3 , within the measurement accuracy around 1--2%. It is also found that the acoustic properties of thin films are generally different from those of bulk materials, depending on the fabrication techniques and conditions

  16. Method of rotation angle measurement in machine vision based on calibration pattern with spot array

    International Nuclear Information System (INIS)

    Li Weimin; Jin Jing; Li Xiaofeng; Li Bin

    2010-01-01

    We propose a method of rotation angle measurement with high precision in machine vision. An area scan CCD camera, imaging lens, and calibration pattern with a spot array make up the measurement device for measuring the rotation angle. The calibration pattern with a spot array is installed at the rotation part, and the CCD camera is set at a certain distance from the rotation components. The coordinates of the spots on the calibration pattern is acquired through the vision image of the calibration pattern captured by the CCD camera. At the initial position of the calibration pattern, the camera is calibrated with the spot array; the mathematical model of distortion error of the CCD camera is built. With the equation of coordinate rotation measurement, the rotation angle of the spot array is detected. In the theoretic simulation, noise of different levels is added to the coordinates of the spot array. The experiment results show that the measurement device can measure the rotation angle precisely with a noncontact method. The standard deviation of rotation angle measurement is smaller than 3 arc sec. The measurement device can measure both microangles and large angles.

  17. Measuring competitiveness of the EPEX spot market for electricity

    International Nuclear Information System (INIS)

    Graf, Christoph; Wozabal, David

    2013-01-01

    The issue of market concentration in electricity markets and resulting possible anti-competitive behavior of producers is a much discussed topic in many countries. We investigate the day-ahead market for electricity at the EPEX, the largest central European market for electricity. To analyze whether generating companies use their market power to influence prices, we use a conjectural variations approach as well as a direct approach to construct marginal costs of electricity production. Given the available data, we cannot reject the hypothesis that there was no systematic abuse of market power by the suppliers of electricity on the EPEX day-ahead spot market for the years 2007–2010. These results are essentially robust when restricting the sample to high load hours, which are generally considered to be the most prone to market manipulation. -- Highlights: •We investigate the efficiency of the German spot market for electricity. •We employ a conjectural variations approach and a fundamental market model. •Peak load hours and base load hours are analyzed separately. •We find that the market was competitive from 2007 to 2010 for both base and peak hours. •Policies to promote market transparency in Germany can be regarded as successful

  18. Skin Friction Measurements Using Luminescent Oil Films

    Science.gov (United States)

    Husen, Nicholas M.

    As aircraft are designed to a greater extent on computers, the need for accurate and fast CFD algorithms has never been greater. The development of CFD algorithms requires experimental data against which CFD output can be validated and from which insight about flow physics can be acquired. Skin friction, in particular, is an important quantity to predict with CFD, and experimental skin friction data sets aid not only with the validation of the CFD predictions, but also in tuning the CFD models to predict specific flow fields. However, a practical experimental technique for collecting spatially and temporally resolved skin friction data on complex models does not yet exist. This dissertation develops and demonstrates a new luminescent oil film skin friction meter which can produce spatially-resolved quantitative steady and unsteady skin friction data on models with complex curvature. The skin friction acting on the surface of a thin film of oil can be approximated by the expression tauw =mu ouh/h, where mu o is the dynamic viscosity of the oil, uh is the velocity of the surface of the oil film, and h is the thickness of the oil film. The new skin friction meter determines skin friction by measuring h and uh. The oil film thickness h is determined by ratioing the intensity of the fluorescent emissions from the oil film with the intensity of the incident light which is scattered from the surface of the model. When properly calibrated, that ratio provides an absolute oil film thickness value. This oil film thickness meter is therefore referred as the Ratioed-Image Film-Thickness (RIFT) Meter. The oil film velocity uh is determined by monitoring the evolution of tagged molecules within the oil film: Photochromic molecules are dissolved into the fluorescent oil and a pattern is written into the oil film using an ultraviolet laser. The evolution of the pattern is recorded, and standard cross-correlation techniques are applied to the resulting sequence of images. This

  19. Reactivity in Rapidly Collected Hygiene and Toilet Spot Check Measurements: A Cautionary Note for Longitudinal Studies

    Science.gov (United States)

    Arnold, Benjamin F.; Khush, Ranjiv S.; Ramaswamy, Padmavathi; Rajkumar, Paramasivan; Durairaj, Natesan; Ramaprabha, Prabhakar; Balakrishnan, Kalpana; Colford Jr., John M.

    2015-01-01

    Discreet collection of spot check observations to measure household hygiene conditions is a common measurement technique in epidemiologic studies of hygiene in low-income countries. The objective of this study was to determine whether the collection of spot check observations in longitudinal studies could itself induce reactivity (i.e., change participant behavior). We analyzed data from a 12-month prospective cohort study in rural Tamil Nadu, India that was conducted in the absence of any hygiene or toilet promotion activities. Our data included hygiene and toilet spot checks from 10,427 household visits. We found substantial evidence of participant reactivity to spot check observations of hygiene practices that were easy to modify on short notice. For example, soap observed at the household's primary handwashing location increased from 49% at enrollment to 81% by the fourth visit and remained at or above 77% for the remainder of the study. PMID:25385856

  20. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Lu, J.; Zhang, Wenqi

    2007-01-01

    The conventional methods of determining the dynamic resistance were mostly done by measuring the voltage and current at secondary side of transformer in resistance welding machines, in which the measuring set-up normally interferes with the movement of electrode, and the measuring precision is in...

  1. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Zhang, Wenqi; Bay, Niels

    Through years, the dynamic resistance across the electrodes has been used for weld quality estimation and contact resistance measurement. However, the previous methods of determining the dynamic resistance were mostly based on measuring the voltage and current on the secondary side...... of the transformer in resistance welding machines, implying defects from induction noise and interference with the leads connected to the electrodes for measuring the voltage. In this study, the dynamic resistance is determined by measuring the voltage on the primary side and the current on the secondary side......, as another application, the proposed method is used to measure the faying surface contact resistance....

  2. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Lu, J.; Zhang, Wenqi

    2007-01-01

    The conventional methods of determining the dynamic resistance were mostly done by measuring the voltage and current at secondary side of transformer in resistance welding machines, in which the measuring set-up normally interferes with the movement of electrode, and the measuring precision...... is influenced by inductive noise caused by the high welding current. In this study, the dynamic resistance is determined by measuring the voltage at primary side and current at secondary side. This increases the accuracy of measurement because of higher signal-noise ratio, and allows to apply to in...

  3. Surface dose extrapolation measurements with radiographic film

    International Nuclear Information System (INIS)

    Butson, Martin J; Cheung Tsang; Yu, Peter K N; Currie, Michael

    2004-01-01

    Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields. An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate two-dimensional map of surface dose if required. Results have shown that the surface percentage dose can be estimated within ±3% of parallel plate ionization chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10 cm, 20 cm and 30 cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. The corresponding parallel plate ionization chamber measurements are 16%, 27% and 37%, respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size. (note)

  4. the value of 5-hydroxy indole acetic acid measurement in spot urine ...

    African Journals Online (AJOL)

    hi-tech

    2004-01-01

    Jan 1, 2004 ... THE VALUE OF 5-HYDROXY INDOLE ACETIC ACID MEASUREMENT IN SPOT URINE IN ... Conclusion: Urine 5-HIAA measurement has low sensitivity and specificity. The value of the test is even clearly lower in gangrenous appendicitis. .... acute appendicitis in the present study displayed negative.

  5. A device for the color measurement and detection of spots on the skin

    Science.gov (United States)

    Pladellorens, Josep; Pintó, Agusti; Segura, Jordi; Cadevall, Cristina; Antó, Joan; Pujol, Jaume; Vilaseca, Meritxell; Coll, Joaquín

    2006-08-01

    In this work we present a new and fast easyâ€``to-use device which allows the measurement of color and the detection of spots on the human skin. The developed device is highly practical for relatively untrained operators and uses inexpensive consumer equipment, such as a CCD color camera, a light source composed of LEDs and a laptop. In order to perform these measurements the system takes a picture of the skin. After that, the operator selects the region of the skin to be analyzed on the image displayed and the system provides the CIELAB color coordinates, the chroma and the ITA parameter (Individual Tipology Angle), allowing the comparison with other reference images by means of the CIELAB color differences. The system also detects the spots, such as freckles, age spots, sun spots, pimples, black heads, etc., in a determined region, allowing the objective measurement of their size and area. The knowledge of the color of the skin and the detection of spots can be useful in several areas such as in dermatology applications, the cosmetics industry, the biometrics field, health care etc.

  6. Fire prevention film spots for television ... narrator influence on knowledge and attitude changes

    Science.gov (United States)

    Gene C. Bernardi

    1973-01-01

    The relative effectiveness of 60-second films on fire prevention, with different narrators, was tested among high school students and by exposure on commercial television channels. The narrators were Smokey Bear, a Youth, and a Ranger. All three films were effective in teaching proper fire use practices to the high school classroom audience. In commercial TV showings,...

  7. School based screening for hypothyroidism in Down's syndrome by dried blood spot TSH measurement

    OpenAIRE

    Noble, S; Leyland, K; Findlay, C; Clark, C; Redfern, J; Mackenzie, J; Girdwood, R; Donaldson, M

    2000-01-01

    OBJECTIVE—To determine the feasibility of annual hypothyroid screening of children with Down's syndrome by measuring thyroid stimulating hormone (TSH) on dried blood spots at school, and to describe the outcome in positive children.
DESIGN—Establishment of a register of school children with Down's syndrome, and procedures for obtaining permission from parents, annual capillary blood samples, TSH measurement, and clinical assessment of children with TSH values > 10 mU/litr...

  8. Blood and dried blood spot telomere length measurement by qPCR: assay considerations.

    Directory of Open Access Journals (Sweden)

    DeAnna L Zanet

    Full Text Available Measurement of telomere length is crucial for the study of telomere maintenance and its role in molecular pathophysiology of diseases and in aging. Several methods are used to measure telomere length, the choice of which usually depends on the type and size of sample to be assayed, as well as cost and throughput considerations. The goal of this study was to investigate the factors that may influence the reliability of qPCR-based relative telomere length measurements in whole blood. Day to day intra-individual variability, types of blood anticoagulant, sample storage conditions, processing and site of blood draw were investigated. Two qPCR-based methods to measure telomere length (monoplex vs. multiplex were also investigated and showed a strong correlation between them. Freezing and thawing of the blood and storage of the blood at 4°C for up to 4 days did not affect telomere length values. Telomere lengths in dried blood spots were significantly higher than both whole blood and peripheral mononuclear blood cells, and were highly correlated with both. We found that telomere length measurements were significantly higher in dried blood spots collected directly from fingertip prick compared to dried blood spots prepared with anticoagulated whole blood collected from the finger, and non-blotted whole blood taken from both finger and arm venipuncture. This suggests that DNA from cells blotted on paper is not equivalent to that collected from venipuncture whole blood, and caution should be taken when comparing between blood sample types.

  9. Comparison between refraction measured by Spot Vision ScreeningTM and subjective clinical refractometry

    Science.gov (United States)

    de Jesus, Daniela Lima; Villela, Flávio Fernandes; Orlandin, Luis Fernando; Eiji, Fernando Naves; Dantas, Daniel Oliveira; Alves, Milton Ruiz

    2016-01-01

    OBJECTIVE: The purpose of this study was to evaluate the accuracy of Spot Vision ScreeningTM as an autorefractor by comparing refraction measurements to subjective clinical refractometry results in children and adult patients. METHODS: One-hundred and thirty-four eyes of 134 patients were submitted to refractometry by Spot and clinical refractometry under cycloplegia. Patients, students, physicians, staff and children of staff from the Hospital das Clínicas (School of Medicine, University of São Paulo) aged 7-50 years without signs of ocular disease were examined. Only right-eye refraction data were analyzed. The findings were converted in magnitude vectors for analysis. RESULTS: The difference between Spot Vision ScreeningTM and subjective clinical refractometry expressed in spherical equivalents was +0.66±0.56 diopters (D), +0.16±0.27 D for the vector projected on the 90 axis and +0.02±0.15 D for the oblique vector. CONCLUSIONS: Despite the statistical significance of the difference between the two methods, we consider the difference non-relevant in a clinical setting, supporting the use of Spot Vision ScreeningTM as an ancillary method for estimating refraction. PMID:26934234

  10. Comparison between refraction measured by Spot Vision Screening™ and subjective clinical refractometry.

    Science.gov (United States)

    de Jesus, Daniela Lima; Villela, Flávio Fernandes; Orlandin, Luis Fernando; Eiji, Fernando Naves; Dantas, Daniel Oliveira; Alves, Milton Ruiz

    2016-02-01

    The purpose of this study was to evaluate the accuracy of Spot Vision Screening™ as an autorefractor by comparing refraction measurements to subjective clinical refractometry results in children and adult patients. One-hundred and thirty-four eyes of 134 patients were submitted to refractometry by Spot and clinical refractometry under cycloplegia. Patients, students, physicians, staff and children of staff from the Hospital das Clínicas (School of Medicine, University of São Paulo) aged 7-50 years without signs of ocular disease were examined. Only right-eye refraction data were analyzed. The findings were converted in magnitude vectors for analysis. The difference between Spot Vision Screening™ and subjective clinical refractometry expressed in spherical equivalents was +0.66±0.56 diopters (D), +0.16±0.27 D for the vector projected on the 90 axis and +0.02±0.15 D for the oblique vector. Despite the statistical significance of the difference between the two methods, we consider the difference non-relevant in a clinical setting, supporting the use of Spot Vision Screening™ as an ancillary method for estimating refraction.

  11. Comparison between refraction measured by Spot Vision ScreeningTM and subjective clinical refractometry

    Directory of Open Access Journals (Sweden)

    Daniela Lima de Jesus

    2016-02-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the accuracy of Spot Vision ScreeningTM as an autorefractor by comparing refraction measurements to subjective clinical refractometry results in children and adult patients. METHODS: One-hundred and thirty-four eyes of 134 patients were submitted to refractometry by Spot and clinical refractometry under cycloplegia. Patients, students, physicians, staff and children of staff from the Hospital das Clínicas (School of Medicine, University of São Paulo aged 7-50 years without signs of ocular disease were examined. Only right-eye refraction data were analyzed. The findings were converted in magnitude vectors for analysis. RESULTS: The difference between Spot Vision ScreeningTM and subjective clinical refractometry expressed in spherical equivalents was +0.66±0.56 diopters (D, +0.16±0.27 D for the vector projected on the 90 axis and +0.02±0.15 D for the oblique vector. CONCLUSIONS: Despite the statistical significance of the difference between the two methods, we consider the difference non-relevant in a clinical setting, supporting the use of Spot Vision ScreeningTM as an ancillary method for estimating refraction.

  12. A computational method to geometric measure of biological particles and application to DNA microarray spot size estimation.

    Science.gov (United States)

    Zhang, Mingjun; Mao, Kaixuan; Tao, Weimin; Tarn, Tzyh-Jong

    2006-04-01

    Geometric measures (volume, area and length) of biological particles are of fundamental interest for biological studies. Many times, the measures are at micro-/nano-scale, and based on images of the biological particles. This paper proposes a computational method to geometric measure of biological particles. The method has been applied to DNA microarray spot size estimation. Compared with existing algorithms for microarray spot size estimation, the proposed method is computational efficient and also provides confidence probability on the measure. The contributions of this paper include a generic computational method to geometric measure of biological particles and application to DNA microarray spot size estimation.

  13. Measurement of the temporal transferability of indoxacarb to cotton gloves from spot-on treated dogs.

    Science.gov (United States)

    Driver, Jeffrey H; Ross, John H; Guerino, Frank; Wrzesinski, Christopher

    2014-01-01

    The objectives of the studies reported herein were to (1) determine the minimum number of petting simulations required to load the maximum amount of test substance (indoxacarb) residue onto cotton gloves (the sampling medium) from spot-on treated dogs; and (2) using the number of petting simulations that resulted in maximal transfer, to conduct a second study that measured amount of residue dislodged via petting a dog as a function of the time interval after application. Maximal percent transfer of indoxacarb from spot-on treated dogs occurred after 10 repetitive petting simulations (consisting of 3 directional pet strokes each) and was approximately 1-2% of amount applied. Temporal measurements of mean indoxacarb transferability followed an exponential decay function, beginning at approximately 2% transfer on the day of application, and declining to 0.08% by d 30 post treatment.

  14. Measurement and application of purine derivatives: Creatinine ratio in spot urine samples of ruminants

    International Nuclear Information System (INIS)

    Chen, X.B.; Jayasuriya, M.C.N.; Makkar, H.P.S.

    2004-01-01

    The daily excretion of purine derivatives in urine has been used to estimate the supply of microbial protein to ruminant animals. The method provides a simple and non-invasive tool to indicate the nutritional status of farm animals. However due to the need for complete collection of urine the potential application at farm level is restricted. Research conducted under the FAO/IAEA Co-ordinated Research Project has indicated that it is possible to use the purine derivatives:creatinine ratio measured in several spot urine samples collected within a day, as an index of microbial protein supply in a banding system for farm application. Some theoretical and experimental aspects in the measurement of purine derivatives:creatinine ratio in spot urine samples and the possible application of the banding system at the farm level are discussed. (author)

  15. Measuring Faecal Epi-Androsterone as an Indicator of Gonadal Activity in Spotted Hyenas (Crocuta crocuta.

    Directory of Open Access Journals (Sweden)

    Susanne Pribbenow

    Full Text Available Enzyme immunoassays (EIA that measure faecal testosterone metabolites (fTM are useful tools to monitor gonadal activity. The aim of this study was to validate an "in-house" epiandrosterone EIA to monitor fTM in spotted hyenas. FTM were characterised in a male and a female hyena that each received an injection of 3H-testosterone. High-performance liquid chromatography (HPLC analyses revealed a cluster of highly polar enzyme-hydrolysable hormone metabolite conjugates. We performed hydrolysis using β-glucuronidase to deconjugate metabolites and improve sensitivity of the assay. Because β-glucuronidase from Helix pomatia has been reported to bias testosterone measurements in some species, we compared the enzymatic activity of the commonly used β-glucuronidase extracted from H. pomatia with the same enzyme from Escherichia coli. Our results showed that β-glucuronidases from both sources produced similar results from spotted hyena faeces. We therefore hydrolysed samples with H. pomatia enzymes. HPLC analyses also demonstrated that following hydrolysis the epiandrosterone EIA measured significant amounts of immunoreactive metabolites corresponding to radiolabelled metabolites in both sexes. Additionally, HPLC and GC-MS analyses confirmed the presence of epiandrosterone in faeces of spotted hyenas. The biological relevance of the epiandrosterone EIA was validated by demonstrating (1 a significant increase in fTM levels in response to a testosterone injection within 16 h, (2 no biological responsiveness to an adrenocorticotropic hormone (ACTH injection and (3 significant differences in fTM levels between juvenile males and adult immigrant males in a free-ranging wild population. Our results clearly demonstrate that the epiandrosterone EIA is a reliable non-invasive method to monitor gonadal activity in spotted hyenas.

  16. Method to measure the position offset of multiple light spots in a distributed aperture laser angle measurement system.

    Science.gov (United States)

    Jing, Xiaoli; Cheng, Haobo; Xu, Chunyun; Feng, Yunpeng

    2017-02-20

    In this paper, an accurate measurement method of multiple spots' position offsets on a four-quadrant detector is proposed for a distributed aperture laser angle measurement system (DALAMS). The theoretical model is put forward, as well as the corresponding calculation method. This method includes two steps. First, as the initial estimation, integral approximation is applied to fit the distributed spots' offset function; second, the Boltzmann function is employed to compensate for the estimation error to improve detection accuracy. The simulation results attest to the correctness and effectiveness of the proposed method, and tolerance synthesis analysis of DALAMS is conducted to determine the maximum uncertainties of manufacturing and installation. The maximum angle error is less than 0.08° in the prototype distributed measurement system, which shows the stability and robustness for prospective applications.

  17. Day-to-day variability in spot urine protein-creatinine ratio measurements.

    Science.gov (United States)

    Naresh, Chetana N; Hayen, Andrew; Craig, Jonathan C; Chadban, Steven J

    2012-10-01

    Accurate measurement of proteinuria is important in the diagnosis and management of chronic kidney disease (CKD). The reference standard test, 24-hour urinary protein excretion, is inconvenient and vulnerable to collection errors. Spot urine protein-creatinine ratio (PCR) is a convenient alternative and is in widespread use. However, day-to-day variability in PCR measurements has not been evaluated. Prospective cohort study of day-to-day variability in spot urine PCR measurement. Clinically stable outpatients with CKD (n = 145) attending a university hospital CKD clinic in Australia between July 2007 and April 2010. Spot urine PCR. Spot PCR variability was assessed and repeatability limits were determined using fractional polynomials. Spot PCRs were measured from urine samples collected at 9:00 am on consecutive days and 24-hour urinary protein excretion was collected concurrently. Paired results were analyzed from 145 patients: median age, 56 years; 59% men; and median 24-hour urinary protein excretion, 0.7 (range, 0.06-35.7) g/d. Day-to-day variability was substantial and increased in absolute terms, but decreased in relative terms with increasing baseline PCR. For patients with a low baseline PCR (20 mg/mmol [177 mg/g]), a change greater than ±160% (repeatability limits, 0-52 mg/mmol [0-460 mg/g]) is required to indicate a real change in proteinuria status with 95% certainty, whereas for those with a high baseline PCR (200 mg/mmol [1,768 mg/g]), a change of ±50% (decrease to 300 mg/mmol [>2,652 mg/g]) represents significant change. These study results need to be replicated in other ethnic groups. Changes in PCR observed in patients with CKD, ranging from complete resolution to doubling of PCR values, could be due to inherent biological variation and may not indicate a change in disease status. This should be borne in mind when using PCR in the diagnosis and management of CKD. Copyright © 2012 National Kidney Foundation, Inc. All rights reserved.

  18. Sensitivity of film measured off-axis ratios to film calibration curve using radiochromic film

    International Nuclear Information System (INIS)

    Garcia-Hernandez, Diana; Larraga-Gutierrez, Jose M.

    2011-01-01

    Off-axis ratios of conical beams generated with a stereotactic radiosurgery-dedicated Linac were measured with EBT2 film and stereotactic diode. The sensitivity of both full width at half maximum (FWHM) and penumbras (80-20% and 90-10%, respectively), with respect to the characteristics of the film calibration curve fit, was investigated. In all cases, penumbras resulted to be more sensitive than FWHM. However, these differences were, in general, smaller than the ones found between EBT2 reference values and the stereotactic diode measurements. The larger variation in OAR parameters was found to depend on whether the fit intersected or not the origin. A 1D gamma-index analysis showed this difference can be important in all measured conical beams. (author)

  19. Measurement of Scenic Spots Sustainable Capacity Based on PCA-Entropy TOPSIS: A Case Study from 30 Provinces, China

    Science.gov (United States)

    Liang, Xuedong; Liu, Canmian; Li, Zhi

    2017-01-01

    In connection with the sustainable development of scenic spots, this paper, with consideration of resource conditions, economic benefits, auxiliary industry scale and ecological environment, establishes a comprehensive measurement model of the sustainable capacity of scenic spots; optimizes the index system by principal components analysis to extract principal components; assigns the weight of principal components by entropy method; analyzes the sustainable capacity of scenic spots in each province of China comprehensively in combination with TOPSIS method and finally puts forward suggestions aid decision-making. According to the study, this method provides an effective reference for the study of the sustainable development of scenic spots and is very significant for considering the sustainable development of scenic spots and auxiliary industries to establish specific and scientific countermeasures for improvement. PMID:29271947

  20. Measurement of Scenic Spots Sustainable Capacity Based on PCA-Entropy TOPSIS: A Case Study from 30 Provinces, China.

    Science.gov (United States)

    Liang, Xuedong; Liu, Canmian; Li, Zhi

    2017-12-22

    In connection with the sustainable development of scenic spots, this paper, with consideration of resource conditions, economic benefits, auxiliary industry scale and ecological environment, establishes a comprehensive measurement model of the sustainable capacity of scenic spots; optimizes the index system by principal components analysis to extract principal components; assigns the weight of principal components by entropy method; analyzes the sustainable capacity of scenic spots in each province of China comprehensively in combination with TOPSIS method and finally puts forward suggestions aid decision-making. According to the study, this method provides an effective reference for the study of the sustainable development of scenic spots and is very significant for considering the sustainable development of scenic spots and auxiliary industries to establish specific and scientific countermeasures for improvement.

  1. Contact chain measurements for ultrathin conducting films

    NARCIS (Netherlands)

    Groenland, A.W.; Wolters, Robertus A.M.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

    2009-01-01

    Test structures for the electrical characterization of ultrathin conductive (ALD) films are presented based on electrodes on which the ultrathin film is deposited. The contact resistance of the buried electrodes to the ultrathin ALD TiN films is investigated using contact chain structures. This work

  2. Spot urine sodium measurements do not accurately estimate dietary sodium intake in chronic kidney disease12

    Science.gov (United States)

    Dougher, Carly E; Rifkin, Dena E; Anderson, Cheryl AM; Smits, Gerard; Persky, Martha S; Block, Geoffrey A; Ix, Joachim H

    2016-01-01

    Background: Sodium intake influences blood pressure and proteinuria, yet the impact on long-term outcomes is uncertain in chronic kidney disease (CKD). Accurate assessment is essential for clinical and public policy recommendations, but few large-scale studies use 24-h urine collections. Recent studies that used spot urine sodium and associated estimating equations suggest that they may provide a suitable alternative, but their accuracy in patients with CKD is unknown. Objective: We compared the accuracy of 4 equations [the Nerbass, INTERSALT (International Cooperative Study on Salt, Other Factors, and Blood Pressure), Tanaka, and Kawasaki equations] that use spot urine sodium to estimate 24-h sodium excretion in patients with moderate to advanced CKD. Design: We evaluated the accuracy of spot urine sodium to predict mean 24-h urine sodium excretion over 9 mo in 129 participants with stage 3–4 CKD. Spot morning urine sodium was used in 4 estimating equations. Bias, precision, and accuracy were assessed and compared across each equation. Results: The mean age of the participants was 67 y, 52% were female, and the mean estimated glomerular filtration rate was 31 ± 9 mL · min–1 · 1.73 m–2. The mean ± SD number of 24-h urine collections was 3.5 ± 0.8/participant, and the mean 24-h sodium excretion was 168.2 ± 67.5 mmol/d. Although the Tanaka equation demonstrated the least bias (mean: −8.2 mmol/d), all 4 equations had poor precision and accuracy. The INTERSALT equation demonstrated the highest accuracy but derived an estimate only within 30% of mean measured sodium excretion in only 57% of observations. Bland-Altman plots revealed systematic bias with the Nerbass, INTERSALT, and Tanaka equations, underestimating sodium excretion when intake was high. Conclusion: These findings do not support the use of spot urine specimens to estimate dietary sodium intake in patients with CKD and research studies enriched with patients with CKD. The parent data for this

  3. Automated translating beam profiler for in situ laser beam spot-size and focal position measurements

    Science.gov (United States)

    Keaveney, James

    2018-03-01

    We present a simple and convenient, high-resolution solution for automated laser-beam profiling with axial translation. The device is based on a Raspberry Pi computer, Pi Noir CMOS camera, stepper motor, and commercial translation stage. We also provide software to run the device. The CMOS sensor is sensitive over a large wavelength range between 300 and 1100 nm and can be translated over 25 mm along the beam axis. The sensor head can be reversed without changing its axial position, allowing for a quantitative estimate of beam overlap with counter-propagating laser beams. Although not limited to this application, the intended use for this device is the automated measurement of the focal position and spot-size of a Gaussian laser beam. We present example data of one such measurement to illustrate device performance.

  4. Measurements of plasma mirror reflectivity and focal spot quality for tens of picosecond laser pulses

    Science.gov (United States)

    Forestier-Colleoni, Pierre; Williams, Jackson; Scott, Graeme; Mariscal, Dereck. A.; McGuffey, Christopher; Beg, Farhat N.; Chen, Hui; Neely, David; Ma, Tammy

    2017-10-01

    The Advanced Radiographic Capability (ARC) laser at the NIF (LLNL) is high-energy ( 4 kJ) with a pulse length of 30ps, and is capable of focusing to an intensity of 1018W/cm2 with a 100 μm focal spot. The ARC laser is at an intensity which can be used to produce proton beams. However, for applications such as radiography and warm dense matter creation, a higher laser intensity may be desired to generate more energetic proton beams. One possibility to increase the intensity is to decrease the focused spot size by employing a smaller f-number optic. But it is difficult to implement such an optic or to bring the final focusing parabola closer to the target within the complicated NIF chamber geometry. A proposal is to use ellipsoidal plasma mirrors (PM) for fast focusing of the ARC laser light, thereby increasing the peak intensity. There is uncertainty, however, in the survivability and reflectivity of PM at such long pulse durations. Here, we show experimental results from the Titan laser to study the reflectivity of flat PM as a function of laser pulse length. A calorimeter was used to measure the PM reflectivity. We also observed degradation of the far and near field energy distribution of the laser after the reflection by the PM for pulse-lengths beyond 10ps. Contract DE-AC52-07NA27344. Funded by the LLNL LDRD program: tracking code 17-ERD-039.

  5. Spotting and validation of a genome wide oligonucleotide chip with duplicate measurement of each gene

    International Nuclear Information System (INIS)

    Thomassen, Mads; Skov, Vibe; Eiriksdottir, Freyja; Tan, Qihua; Jochumsen, Kirsten; Fritzner, Niels; Brusgaard, Klaus; Dahlgaard, Jesper; Kruse, Torben A.

    2006-01-01

    The quality of DNA microarray based gene expression data relies on the reproducibility of several steps in a microarray experiment. We have developed a spotted genome wide microarray chip with oligonucleotides printed in duplicate in order to minimise undesirable biases, thereby optimising detection of true differential expression. The validation study design consisted of an assessment of the microarray chip performance using the MessageAmp and FairPlay labelling kits. Intraclass correlation coefficient (ICC) was used to demonstrate that MessageAmp was significantly more reproducible than FairPlay. Further examinations with MessageAmp revealed the applicability of the system. The linear range of the chips was three orders of magnitude, the precision was high, as 95% of measurements deviated less than 1.24-fold from the expected value, and the coefficient of variation for relative expression was 13.6%. Relative quantitation was more reproducible than absolute quantitation and substantial reduction of variance was attained with duplicate spotting. An analysis of variance (ANOVA) demonstrated no significant day-to-day variation

  6. Measurement error in longitudinal film badge data

    International Nuclear Information System (INIS)

    Marsh, J.L.

    2002-04-01

    The classical measurement error model is that of a simple linear regression with unobservable variables. Information about the covariates is available only through error-prone measurements, usually with an additive structure. Ignoring errors has been shown to result in biased regression coefficients, reduced power of hypothesis tests and increased variability of parameter estimates. Radiation is known to be a causal factor for certain types of leukaemia. This link is mainly substantiated by the Atomic Bomb Survivor study, the Ankylosing Spondylitis Patients study, and studies of various other patients irradiated for therapeutic purposes. The carcinogenic relationship is believed to be a linear or quadratic function of dose but the risk estimates differ widely for the different studies. Previous cohort studies of the Sellafield workforce have used the cumulative annual exposure data for their risk estimates. The current 1:4 matched case-control study also uses the individual worker's film badge data, the majority of which has been unavailable in computerised form. The results from the 1:4 matched (on dates of birth and employment, sex and industrial status) case-control study are compared and contrasted with those for a 1:4 nested (within the worker cohort and matched on the same factors) case-control study using annual doses. The data consist of 186 cases and 744 controls from the work forces of four BNFL sites: Springfields, Sellafield, Capenhurst and Chapelcross. Initial logistic regressions turned up some surprising contradictory results which led to a re-sampling of Sellafield mortality controls without the date of employment matching factor. It is suggested that over matching is the cause of the contradictory results. Comparisons of the two measurements of radiation exposure suggest a strongly linear relationship with non-Normal errors. A method has been developed using the technique of Regression Calibration to deal with these in a case-control study context

  7. Electrical and electrochemical measurements in nanostructured films of polythiophene derivatives

    International Nuclear Information System (INIS)

    Braunger, Maria L.; Barros, Anerise; Ferreira, Marystela; Olivati, Clarissa A.

    2015-01-01

    Thin films from polythiophene derivatives can be fabricated by some experimental methods, including the Langmuir techniques, which are particularly suitable if some degree of molecular control is required. In this study, electrical and electrochemical measurements in Langmuir-Schaefer and spin-coated films of polythiophene derivatives were carried out in order to compare the influence of the deposition technique in these properties. Through cyclic voltammetry and UV-visible absorption measurements it was possible to estimate the energy diagrams for all the polythiophene films. Besides, electrochromic effect in the polythiophene thin films was observed

  8. Measurements of purine derivatives and creatinine in spot urine samples of Chinese yellow cattle

    International Nuclear Information System (INIS)

    Xing, Z.; Xi, W.B.; Mo, F.; Liu, J.W.; Yang, Y.F.; Chen, X.B.

    2004-01-01

    An experiment was conducted using 18 Chinese Yellow Cattle located in 5 farms to study how supplementation of fermentable energy to low quality straw-based rations would improve rumen microbial protein synthesis. Within each farm, the animals were fed on five diets. Diets 1-2 were typical rice straw + by-products used by farmers and were low in fermentable energy content; Diets 3- 5 were more balanced, containing a higher content of fermentable energy. Purine derivatives (PD) and creatinine in spot urine samples were measured. The results showed that the PD to creatinine ratio was significantly higher with Diets 3-5 than with Diets 1-2. Organic matter digestibility and thus organic matter intake was also higher with Diets 3-5 compared to Diets 1-2. The results indicted that the efficiency of microbial protein synthesis could be improved by balancing the diet. (author)

  9. Adiponectin levels measured in dried blood spot samples from neonates born small and appropriate for gestational age

    DEFF Research Database (Denmark)

    Klamer, A; Skogstrand, Kristin; Hougaard, D M

    2007-01-01

    Adiponectin levels measured in neonatal dried blood spot samples (DBSS) might be affected by both prematurity and being born small for gestational age (SGA). The aim of the study was to measure adiponectin levels in routinely collected neonatal DBSS taken on day 5 (range 3-12) postnatal from...

  10. Dosimetric evaluation of a commercial proton spot scanning Monte-Carlo dose algorithm: comparisons against measurements and simulations

    Science.gov (United States)

    Saini, Jatinder; Maes, Dominic; Egan, Alexander; Bowen, Stephen R.; St. James, Sara; Janson, Martin; Wong, Tony; Bloch, Charles

    2017-10-01

    RaySearch Americas Inc. (NY) has introduced a commercial Monte Carlo dose algorithm (RS-MC) for routine clinical use in proton spot scanning. In this report, we provide a validation of this algorithm against phantom measurements and simulations in the GATE software package. We also compared the performance of the RayStation analytical algorithm (RS-PBA) against the RS-MC algorithm. A beam model (G-MC) for a spot scanning gantry at our proton center was implemented in the GATE software package. The model was validated against measurements in a water phantom and was used for benchmarking the RS-MC. Validation of the RS-MC was performed in a water phantom by measuring depth doses and profiles for three spread-out Bragg peak (SOBP) beams with normal incidence, an SOBP with oblique incidence, and an SOBP with a range shifter and large air gap. The RS-MC was also validated against measurements and simulations in heterogeneous phantoms created by placing lung or bone slabs in a water phantom. Lateral dose profiles near the distal end of the beam were measured with a microDiamond detector and compared to the G-MC simulations, RS-MC and RS-PBA. Finally, the RS-MC and RS-PBA were validated against measured dose distributions in an Alderson-Rando (AR) phantom. Measurements were made using Gafchromic film in the AR phantom and compared to doses using the RS-PBA and RS-MC algorithms. For SOBP depth doses in a water phantom, all three algorithms matched the measurements to within  ±3% at all points and a range within 1 mm. The RS-PBA algorithm showed up to a 10% difference in dose at the entrance for the beam with a range shifter and  >30 cm air gap, while the RS-MC and G-MC were always within 3% of the measurement. For an oblique beam incident at 45°, the RS-PBA algorithm showed up to 6% local dose differences and broadening of distal fall-off by 5 mm. Both the RS-MC and G-MC accurately predicted the depth dose to within  ±3% and distal fall-off to within 2

  11. A new measurement method for the dynamic resistance signal during the resistance spot welding process

    International Nuclear Information System (INIS)

    Wang, Lijing; Hou, Yanyan; Zhao, Jian; Zhang, Hongjie; Xi, Tao; Qi, Xiangyang; Li, Yafeng

    2016-01-01

    To measure the dynamic resistance signal during the resistance spot welding process, some original work was carried out and a new measurement method was developed. Compared with the traditional method, using the instantaneous electrode voltage and welding current at peak current point in each half cycle, the resistance curve from the newly proposed method can provide more details of the dynamic resistance changes over time. To test the specific performance of the proposed method, a series of welding experiments were carried out and the tensile shear strengths of the weld samples were measured. Then, the measurement error of the proposed method was evaluated. Several features were extracted from the dynamic resistance curves. The correlations between the extracted features and weld strength were analyzed and the results show that these features are closely related to the weld strength and they can be used for welding quality monitoring. Moreover, the dynamic resistance curve from the newly proposed method can also be used to monitor some abnormal welding conditions. (paper)

  12. Spot urine protein measurements in normotensive pregnancies, pregnancies with isolated proteinuria and preeclampsia.

    Science.gov (United States)

    Kattah, Andrea; Milic, Natasa; White, Wendy; Garovic, Vesna

    2017-10-01

    We performed a prospective, longitudinal study of pregnant women presenting to their first obstetrics visits to characterize the changes in spot urine protein-to-creatinine (UPCR) and albumin-to-creatinine ratios (UACR) in normotensive pregnancies, as well as identify clinical characteristics associated with isolated proteinuria and preeclampsia. We measured spot urinary albumin, protein, and creatinine at the first prenatal visit, end of the second trimester, and at delivery. In the normotensive pregnancies ( n = 142), we found that from the beginning of pregnancy to delivery, UACR increased by a median [interquartile range (IQR)] of 14.7 mg/g Cr (3.74-51.8) and UPCR by 60 mg/g Cr (30-130) ( P 300 mg/g Cr in the absence of hypertension) was identified in 19/142 (13.4%) normotensive pregnancies. Increases in systolic and diastolic blood pressure from early pregnancy to delivery and increases in UACR from early to midpregnancy were associated with isolated proteinuria at delivery. Twelve women developed preeclampsia. Nulliparity, early, and midpregnancy diastolic blood pressures were strongly associated with the development of preeclampsia, but early changes in UACR were not. In conclusion, women who develop isolated proteinuria at delivery have a larger increase in blood pressure than women without proteinuria and have a "microalbuminuric" phase earlier in gestation, unlike women who develop preeclampsia. These findings suggest a different mechanism of urine protein excretion in women with isolated proteinuria as compared with women with preeclampsia, where proteinuria has a more abrupt onset. Copyright © 2017 the American Physiological Society.

  13. SPOT Program

    Science.gov (United States)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; hide

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  14. Residual stress measurement on propellant tank of 2219 aluminum alloy and study on its weak spot

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chaoqun; Li, Huan; Li, Jianxiong; Luo, Chuanguang; Ni, Yanbing [Tianjin University, Tianjin (China)

    2017-05-15

    This paper presented residual stress measurement on two circumferential Variable polarity plasma arc welding (VPPAW) joints and one circular closed Friction stir welding (FSW) joint on the propellant tank of 2219 aluminum alloy using the indentation strain-gauge method. Quite large tensile residual stresses were attached to the center and inner areas of the circular closed FSW joint. There were very large tensile stresses in some points of the two circumferential VPPAW joints, among these points, the maximum value was +253 MPa, which was about 63 % of the yield strength of 410 MPa measured in the base material. In addition, the peak of compressive residual stress was about -160 MPa. Above all, there were two typical peaks of residual stress in the circumferential VPPAW joints, one was located in the middle part while the other one was near the start/end position of the joints. Combining the result of residual stress measurement with the characteristics of the tank structure, it can be concluded that circular closed FSW joint around the flange was a weak spot on the propellant tank. And the most vulnerable point on the circular closed FSW joint has also been found.

  15. Spot Surface Labeling of Magnetic Microbeads and Application in Biological Force Measurements

    Science.gov (United States)

    Estes, Ashley; O'Brien, E. Tim; Hill, David; Superfine, Richard

    2006-11-01

    Biological force measurements on single molecules and macromolecular structures often use microbeads for the application of force. These techniques are often complicated by multiple attachments and nonspecific binding. In one set of experiments, we are applying a magnetic force microscope that allows us to pull on magnetic beads attached to ciliated human bronchial epithelial cells. These experiments provide a means to measure the stall force of cilia and understand how cilia propel fluids. However, because we are using beads with diameters of one and 2.8 microns, and the diameter of human airway cilia is approximately 200 nm, we cannot be assured that the bead is bound to a single cilium. To address this, we have developed a sputter coating technique to block the biotin binding capability of the streptavidin labeled bead over its entire surface except for a small spot. These beads may also have applications in other biological experiments such as DNA force experiments in which binding of a single target to an individual bead is critical.

  16. Creatinine measurement on dry blood spot sample for chronic kidney disease screening.

    Science.gov (United States)

    Silva, Alan Castro Azevedo E; Gómez, Juan Fidel Bencomo; Lugon, Jocemir Ronaldo; Graciano, Miguel Luis

    2016-03-01

    Chronic kidney disease (CKD) screening is advisable due to its high morbidity and mortality and is usually performed by sampling blood and urine. Here we present an innovative and simpler method, by measuring creatinine on a dry blood spot on filter paper. One-hundred and six individuals at high risk for CKD were enrolled. The creatinine values obtained using both tests and the demographic data of each participant allowed us to determinate the eGFR. The adopted cutoff for CKD was an eGFR value 96%, predictive negative value 55% and accuracy 92%. By the CKD-EPI equation the sensitivity was 94%, specificity 55%, predictive positive value 94%, predictive negative value 55% and accuracy 90%. A Bland and Altman analysis showed a relatively narrow range of creatinine values differences (+ 0.68mg/dl to -0.55mg/dl) inside the ± 1.96 SD, without systematic differences. Measurement of creatinine on dry blood sample is an easily feasible non-invasive diagnostic test with good accuracy that may be useful to screen chronic kidney disease.

  17. Bubble chamber film exposure for measurement by HPD

    International Nuclear Information System (INIS)

    Oxley, A.J.

    1978-03-01

    It is not easy for HPD measuring machines to detect tracks of low contrast in film from bubble chambers with bright-field illumination. Some of the basic aspects and limitations are considered in this paper. (author)

  18. Elastic Films for Cyrogenic Skin Friction Measurements, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Here we introduce a new sensor for measurement of skin friction and pressure, Surface Stress Sensitive Film (S3F). This technique can operate over a range of...

  19. A Model to Measure Tourist Preference toward Scenic Spots Based on Social Media Data: A Case of Dapeng in China

    Directory of Open Access Journals (Sweden)

    Yao Sun

    2017-12-01

    Full Text Available Research on tourist preference toward different tourism destinations has been a hot topic for decades in the field of tourism development. Tourist preference is mostly measured with small group opinion-based methods through introducing indicator systems in previous studies. In the digital age, e-tourism makes it possible to collect huge volumes of social data produced by tourists from the internet, to establish a new way of measuring tourist preference toward a close group of tourism destinations. This paper introduces a new model using social media data to quantitatively measure the market trend of a group of scenic spots from the angle of tourists’ demand, using three attributes: tourist sentiment orientation, present tourist market shares, and potential tourist awareness. Through data mining, cleaning, and analyzing with the framework of Machine Learning, the relative tourist preference toward 34 scenic spots closely located in the Dapeng Peninsula is calculated. The results not only provide a reliable “A-rating” system to gauge the popularity of different scenic spots, but also contribute an innovative measuring model to support scenic spots planning and policy making in the regional context.

  20. Multi-image oil-film interferometry skin friction measurements

    International Nuclear Information System (INIS)

    Naughton, J W; Hind, M D

    2013-01-01

    The benefits of analyzing multiple interferogram images obtained using oil-film interferometry in order to determine wall shear stress are assessed. Both dual- and multi-image analysis approaches are implemented and compared to standard single interferogram approaches. Each of the analysis approaches is derived from the thin oil-film equation. To assess the different implementations, both experimental interferograms and simulated oil films are used. The simulations determine the oil-film height as a function of space and time by solving the thin oil-film equation subject to a known wall shear stress distribution, whereas experimental interferograms were obtained in a turbulent flat plate boundary layer. The results of analyzing these data with the three different analysis approaches suggest that they all work equally well when test conditions are approximately steady. For tunnels with long transients at startup or when multiple test conditions need to be measured in a single run, the multi-image approach is recommended. (paper)

  1. Measurement and Comparison of Organic Compound Concentrations in Plasma, Whole Blood and Dried Blood Spot Samples

    Directory of Open Access Journals (Sweden)

    Stuart A Batterman

    2016-04-01

    Full Text Available The preferred sampling medium for measuring human exposures of persistent organic compounds (POPs is blood, and relevant sample types include whole blood, plasma, and dried blood spots (DBS. Because information regarding the performance and comparability of measurements across these sample types is limited, it is difficult to compare across studies. This study evaluates the performance of POP measurements in plasma, whole blood and DBS, and presents the distribution coefficients needed to convert concentrations among the three sample types. Blood samples were collected from adult volunteers, along with demographic and smoking information, and analyzed by GC/MS for organochlorine pesticides (OCPs, chlorinated hydrocarbons (CHCs, polychlorinated biphenyls (PCBs, and brominated diphenyl ethers (PBDEs. Regression models were used to evaluate the relationships between the sample types and possible effects of personal covariates. Distribution coefficients also were calculated using physically-based models.Across all compounds, concentrations in plasma were consistently the highest; concentrations in whole blood and DBS samples were comparable. Distribution coefficients for plasma to whole blood concentrations ranged from 1.74 to 2.26 for pesticides/CHCs, averaged 1.69 ± 0.06 for the PCBs, and averaged 1.65 ± 0.03 for the PBDEs. Regression models closely fit most chemicals (R2 > 0.80, and whole blood and DBS samples generally showed very good agreement. Distribution coefficients estimated using biologically-based models were near one and did not explain the observed distribution. Among the study population, median concentrations of several pesticides/CHCs and PBDEs exceeded levels reported in the 2007-2008 National Health and Nutrition Examination Survey, while levels of other OCPs and PBDEs were comparable or lower. Race and smoking status appeared to slightly affect plasma/blood concentration ratios for several POPs. The experimentally

  2. Simultaneous measurements of top surface and its underlying film surfaces in multilayer film structure.

    Science.gov (United States)

    Ghim, Young-Sik; Rhee, Hyug-Gyo; Davies, Angela

    2017-09-19

    With the growth of 3D packaging technology and the development of flexible, transparent electrodes, the use of multilayer thin-films is steadily increasing throughout high-tech industries including semiconductor, flat panel display, and solar photovoltaic industries. Also, this in turn leads to an increase in industrial demands for inspection of internal analysis. However, there still remain many technical limitations to overcome for measurement of the internal structure of the specimen without damage. In this paper, we propose an innovative optical inspection technique for simultaneous measurements of the surface and film thickness corresponding to each layer of multilayer film structures by computing the phase and reflectance over a wide range of wavelengths. For verification of our proposed method, the sample specimen of multilayer films was fabricated via photolithography process, and the surface profile and film thickness of each layer were measured by two different techniques of a stylus profilometer and an ellipsometer, respectively. Comparison results shows that our proposed technique enables simultaneous measurements of the top surface and its underlying film surfaces with high precision, which could not be measured by conventional non-destructive methods.

  3. Magnetic hysteresis measurements of thin films under isotropic stress.

    Science.gov (United States)

    Holland, Patrick; Dubey, Archana; Geerts, Wilhelmus

    2000-10-01

    Nowadays, ferromagnetic thin films are widely applied in devices for information technology (credit cards, video recorder tapes, floppies, hard disks) and sensors (air bags, anti-breaking systems, navigation systems). Thus, with the increase in the use of magnetic media continued investigation of magnetic properties of materials is necessary to help in determining the useful properties of materials for new or improved applications. We are currently interested in studying the effect of applied external stress on Kerr hysteresis curves of thin magnetic films. The Ni and NiFe films were grown using DC magnetron sputtering with Ar as the sputter gas (pAr=4 mTorr; Tsub=55-190 C). Seed and cap layers of Ti were used on all films for adhesion and oxidation protection, respectively. A brass membrane pressure cell was designed to apply in-plane isotropic stress to thin films. In this pressure cell, gas pressure is used to deform a flexible substrate onto which a thin magnetic film has been sputtered. The curvature of the samples could be controlled by changing the gas pressure to the cell. Magneto-Optical in-plane hysteresis curves at different values of strain were measured. The results obtained show that the stress sensitivity is dependent on the film thickness. For the 500nm NiFe films, the coercivity strongly decreased as a function of the applied stress.

  4. In situ measurement of conductivity during nanocomposite film deposition

    International Nuclear Information System (INIS)

    Blattmann, Christoph O.; Pratsinis, Sotiris E.

    2016-01-01

    Highlights: • Flame-made nanosilver dynamics are elucidated in the gas-phase & on substrates. • The resistance of freshly depositing nanosilver layers is monitored. • Low T g polymers facilitate rapid synthesis of conductive films. • Conductive nanosilver films form on top of or within the polymer depending on MW. - Abstract: Flexible and electrically conductive nanocomposite films are essential for small, portable and even implantable electronic devices. Typically, such film synthesis and conductivity measurement are carried out sequentially. As a result, optimization of filler loading and size/morphology characteristics with respect to film conductivity is rather tedious and costly. Here, freshly-made Ag nanoparticles (nanosilver) are made by scalable flame aerosol technology and directly deposited onto polymeric (polystyrene and poly(methyl methacrylate)) films during which the resistance of the resulting nanocomposite is measured in situ. The formation and gas-phase growth of such flame-made nanosilver, just before incorporation onto the polymer film, is measured by thermophoretic sampling and microscopy. Monitoring the nanocomposite resistance in situ reveals the onset of conductive network formation by the deposited nanosilver growth and sinternecking. The in situ measurement is much faster and more accurate than conventional ex situ four-point resistance measurements since an electrically percolating network is detected upon its formation by the in situ technique. Nevertheless, general resistance trends with respect to filler loading and host polymer composition are consistent for both in situ and ex situ measurements. The time lag for the onset of a conductive network (i.e., percolation) depends linearly on the glass transition temperature (T g ) of the host polymer. This is attributed to the increased nanoparticle-polymer interaction with decreasing T g . Proper selection of the host polymer in combination with in situ resistance monitoring

  5. In situ measurement of conductivity during nanocomposite film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Blattmann, Christoph O.; Pratsinis, Sotiris E., E-mail: sotiris.pratsinis@ptl.mavt.ethz.ch

    2016-05-15

    Highlights: • Flame-made nanosilver dynamics are elucidated in the gas-phase & on substrates. • The resistance of freshly depositing nanosilver layers is monitored. • Low T{sub g} polymers facilitate rapid synthesis of conductive films. • Conductive nanosilver films form on top of or within the polymer depending on MW. - Abstract: Flexible and electrically conductive nanocomposite films are essential for small, portable and even implantable electronic devices. Typically, such film synthesis and conductivity measurement are carried out sequentially. As a result, optimization of filler loading and size/morphology characteristics with respect to film conductivity is rather tedious and costly. Here, freshly-made Ag nanoparticles (nanosilver) are made by scalable flame aerosol technology and directly deposited onto polymeric (polystyrene and poly(methyl methacrylate)) films during which the resistance of the resulting nanocomposite is measured in situ. The formation and gas-phase growth of such flame-made nanosilver, just before incorporation onto the polymer film, is measured by thermophoretic sampling and microscopy. Monitoring the nanocomposite resistance in situ reveals the onset of conductive network formation by the deposited nanosilver growth and sinternecking. The in situ measurement is much faster and more accurate than conventional ex situ four-point resistance measurements since an electrically percolating network is detected upon its formation by the in situ technique. Nevertheless, general resistance trends with respect to filler loading and host polymer composition are consistent for both in situ and ex situ measurements. The time lag for the onset of a conductive network (i.e., percolation) depends linearly on the glass transition temperature (T{sub g}) of the host polymer. This is attributed to the increased nanoparticle-polymer interaction with decreasing T{sub g}. Proper selection of the host polymer in combination with in situ resistance

  6. Hot Films on Ceramic Substrates for Measuring Skin Friction

    Science.gov (United States)

    Noffz, Greg; Leiser, Daniel; Bartlett, Jim; Lavine, Adrienne

    2003-01-01

    Hot-film sensors, consisting of a metallic film on an electrically nonconductive substrate, have been used to measure skin friction as far back as 1931. A hot film is maintained at an elevated temperature relative to the local flow by passing an electrical current through it. The power required to maintain the specified temperature depends on the rate at which heat is transferred to the flow. The heat transfer rate correlates to the velocity gradient at the surface, and hence, with skin friction. The hot-film skin friction measurement method is most thoroughly developed for steady-state conditions, but additional issues arise under transient conditions. Fabricating hot-film substrates using low-thermal-conductivity ceramics can offer advantages over traditional quartz or polyester-film substrates. First, a low conductivity substrate increases the fraction of heat convected away by the fluid, thus increasing sensitivity to changes in flow conditions. Furthermore, the two-part, composite nature of the substrate allows the installation of thermocouple junctions just below the hot film, which can provide an estimate of the conduction heat loss.

  7. Infrared reflectance measurement for InN thin film characterization

    International Nuclear Information System (INIS)

    Fukui, K.; Kugumiya, Y.; Nakagawa, N.; Yamamoto, A.

    2006-01-01

    Infrared reflectance measurements of a series of InN thin films have been performed and attempt to derive carrier concentration and other physical constants for InN thin film characterization. Fitting calculations are performed by use of the dielectric function equation based on phonon-plasmon coupling model. Longitudinal and transverse optical phonon frequencies, plasma frequency and their damping parameters can be derived from fitting. From those results, electrical and phonon properties of InN and characterization of films are discussed. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Optical methods for thickness measurements on thin metal films.

    Science.gov (United States)

    Pokrowsky, P

    1991-08-01

    The thickness and the dielectric constants of thin metal films on glass substrates are determined by two different methods. The first method is a combination of transmission and ellipsometer measurements (TELL method) and the second is based on attenuated total reflection (ATR method in the Kretschmann arrangement). For comparison, both methods are applied to gold films within a thickness range of 20-80 nm. Furthermore, the TELL method was applied to chromium films of thicknesses up to 150 nm. All experiments are done with a He-Ne laser at 633-nm wavelength.

  9. Study of PEDOT conductive polymer films by admittance measurements

    International Nuclear Information System (INIS)

    Tamburri, Emanuela; Sarti, Stefano; Orlanducci, Silvia; Terranova, Maria Letizia; Rossi, Marco

    2011-01-01

    Research highlights: → Microwave technique to measure the conductivity of PEDOT films. → PEDOT conductivity depends on its mesoscopic scale structure and oxidation level. → Raman spectroscopy and SEM analysis to study structure and morphology of PEDOT. → Microwave measurements allow determination of the macroscopic scale conductivity. → Microwave measurements overcome problems related to the local structural defects and inhomogeneities of PEDOT. - Abstract: In this paper we propose the use of a microwave technique to measure the conductivity of poly(3,4-ethylenedioxythiophene) (PEDOT) films. The PEDOT layers were prepared by electropolymerization from aqueous solutions using both poly(sodium 4-styrene sulphonate) (NaPSS) and sodium dodecyl sulphate (NaDS) acting as monomer solubilizer and dopant for the polymer. The conductive properties of a series of samples produced under different synthesis conditions and characterized by different structures have been investigated by microwave measurements in the frequency range from 40 MHz to 40 GHz by using a Corbino disc geometry. Such technique allows to estimate the mean conductivity of the polymer samples overcoming the limitations of the measuring configurations typically imposed by the conventional d.c. measurements. The morphology of PEDOT films and the structure of polymer chains were studied by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. The correlated morphological, structural and microwave analysis enabled us to evidence several factors that affect the macroscopic scale conductivity of the polymer sample films and to identify the conditions for preparation of PEDOT films with functional properties relevant to technological applications.

  10. Polymer film strain gauges for measuring large elongations

    Science.gov (United States)

    Kondratov, A. P.; Zueva, A. M.; Varakin, R. S.; Taranec, I. P.; Savenkova, I. A.

    2018-02-01

    The paper shows the possibility to print polymer strain gages, microstrip lines, coplanar waveguides, and other prints for avionics using printing technology and equipment. The methods of screen and inkjet printing have been complemented by three new operations of preparing print films for application of an electrically conductive ink layer. Such additional operations make it possible to enhance the conductive ink layer adhesion to the film and to manufacture strain gages for measuring large elongations.

  11. Measurements of proton energy spectra using a radiochromic film stack

    Science.gov (United States)

    Filkins, T. M.; Steidle, Jessica; Ellison, D. M.; Steidle, Jeffrey; Freeman, C. G.; Padalino, S. J.; Fiksel, G.; Regan, S. P.; Sangster, T. C.

    2014-10-01

    The energy spectrum of protons accelerated from the rear-side of a thin foil illuminated with ultra-intense laser light from the OMEGA EP laser system at the University of Rochester's Laboratory for Laser Energetics (LLE) was measured using a stack of radiochromic film (RCF). The film stack consisted of four layers of Gafchromic HD-V2 film and four layers of Gafchromic MD-V2-55 film. Aluminum foils of various thicknesses were placed between each piece of RCF in the stack. This arrangement allowed protons with energies of 30 MeV to reach the back layer of RCF in the stack. The stack was placed in the detector plane of a Thomson parabola ion energy (TPIE) spectrometer. Each piece of film in the stack was scanned using a commercially available flat-bed scanner (Epson 10000XL). The resulting optical density was converted into proton fluence using an absolute calibration of the RCF obtained at the SUNY Geneseo 1.7 MV Pelletron accelerator laboratory. In these calibration measurements, the sensitivity of the radiochromic film was measured using monoenergetic protons produced by the accelerator. Details of the analysis procedure and the resulting proton energy spectra will be presented. Funded in part by a grant from the DOE through the Laboratory for Laser Energetics.

  12. The light spot test: Measuring anxiety in mice in an automated home-cage environment.

    Science.gov (United States)

    Aarts, Emmeke; Maroteaux, Gregoire; Loos, Maarten; Koopmans, Bastijn; Kovačević, Jovana; Smit, August B; Verhage, Matthijs; Sluis, Sophie van der

    2015-11-01

    Behavioral tests of animals in a controlled experimental setting provide a valuable tool to advance understanding of genotype-phenotype relations, and to study the effects of genetic and environmental manipulations. To optimally benefit from the increasing numbers of genetically engineered mice, reliable high-throughput methods for comprehensive behavioral phenotyping of mice lines have become a necessity. Here, we describe the development and validation of an anxiety test, the light spot test, that allows for unsupervised, automated, high-throughput testing of mice in a home-cage system. This automated behavioral test circumvents bias introduced by pretest handling, and enables recording both baseline behavior and the behavioral test response over a prolonged period of time. We demonstrate that the light spot test induces a behavioral response in C57BL/6J mice. This behavior reverts to baseline when the aversive stimulus is switched off, and is blunted by treatment with the anxiolytic drug Diazepam, demonstrating predictive validity of the assay, and indicating that the observed behavioral response has a significant anxiety component. Also, we investigated the effectiveness of the light spot test as part of sequential testing for different behavioral aspects in the home-cage. Two learning tests, administered prior to the light spot test, affected the light spot test parameters. The light spot test is a novel, automated assay for anxiety-related high-throughput testing of mice in an automated home-cage environment, allowing for both comprehensive behavioral phenotyping of mice, and rapid screening of pharmacological compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Different approaches how to deal with the South Atlantic Anomaly effect on the SPOT-5 DORIS measurement

    Science.gov (United States)

    Stepanek, P.; Filler, V.; Dousa, J.; Rodriguez Solano, C.; Hugentobler, U.

    2012-04-01

    The South Atlantic Anomaly (SAA) refers to the area where the Earth's inner Van Allen radiation belt comes closest to the Earth's surface, leading to increased levels of cosmic radiation at lower altitudes than elsewhere over the surface. A strong effect of the SAA on the quality of Jason-1 DORIS observations is well known and documented. However, the significant effect of SAA on the SPOT-5 DORIS observations has been observed as well by recent DORIS data analyses. The SAA affects the frequency of onboard oscillator and consequently estimated values of the parameters as the beacon frequency offset, the station height and the troposphere zenithal delay. The SAA effects mainly the SPOT-5 observations of the three stations in South America, i.e., Cachoeira Paulista (Brasil), Arequipa (Peru) and Santiago (Chile). The offset of the estimated station height achieves 27 cm for the SPOT-5 individual solution and the most biased station Cachoeira Paulista. Since the general quality of the SPOT-5 measurements is very good, the complete exclusion of the satellite from the combination is not kind of a rational approach. One possibility how to handle the problem is to exclude the regional stations from the solutions. There are two different ways, total elimination or using these data for orbit determination but not for the multi-satellite coordinate estimation. Another possibility is based on the application of the data corrective model. A simple empirical data corrective model has been developed, based on statistical analyses of the post-fit residuals.

  14. Measurements of the sensitivity of radiochromic film using ion beams

    Science.gov (United States)

    Steidle, J. A.; Shortino, J. P.; Ellison, D. M.; Freeman, C. G.; Sangster, T. C.

    2013-10-01

    Radiochromic film (RCF) is used in several diagnostics as a dosimeter that chromatically responds to incident particles. This response depends on the fluence, energy, and species of the incident particles. A 1.7 MV tandem Pelletron accelerator is used to create a monoenergetic ion beam which is scattered off a thin gold target onto a strip of RCF. A surface barrier detector is positioned behind a small hole in the film to measure the ion fluence on the nearby film. Once the film develops, it is scanned to examine its optical density. A response curve is acquired by fitting a three parameter formula to optical density and dose. These calibration curves can be used to help determine incident doses in a variety of situations.

  15. NOTE: Surface dose extrapolation measurements with radiographic film

    Science.gov (United States)

    Butson, Martin J.; Cheung, Tsang; Yu, Peter K. N.; Currie, Michael

    2004-07-01

    Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields. An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate two-dimensional map of surface dose if required. Results have shown that the surface percentage dose can be estimated within ±3% of parallel plate ionization chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10 cm, 20 cm and 30 cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. The corresponding parallel plate ionization chamber measurements are 16%, 27% and 37%, respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size.

  16. Identification of measures for prevention of black spots in organically produced stored carrots

    NARCIS (Netherlands)

    Köhl, J.; Kastelein, P.; Elderson, J.; Blok, W.J.

    2005-01-01

    In the Netherlands winter carrot for the fresh market is a cash crop for many organic growers of field vegetables. In the last few years blackish spots have been observed during storage of carrot roots. An inventory was carried out in 2001/2002 and 2002/2003 including in total 42 carrot lots from 22

  17. Nondestructive Measurement of Dynamic Modulus for Cellulose Nanofibril Films

    Science.gov (United States)

    Yan Qing; Robert J. Ross; Zhiyong Cai; Yiqiang Wu

    2013-01-01

    Nondestructive evaluation of cellulose nanofibril (CNF) films was performed using cantilever beam vibration (CBV) and acoustic methods to measure dynamic modulus. Static modulus was tested using tensile tension method. Correlation analysis shows the data measured by CBV has little linear relationship with static modulus, possessing a correlation coefficient (R

  18. Magnetostriction measurement in thin films using laser Doppler vibrometry

    International Nuclear Information System (INIS)

    Varghese, Ronnie; Viswan, Ravindranath; Joshi, Keyur; Seifikar, Safoura; Zhou, Yuan; Schwartz, Justin; Priya, Shashank

    2014-01-01

    This paper reports the laser Doppler vibrometry based measurement of the magnetostriction in magnetic thin films. Using this method, the strain induced by an AC magnetic field in the polycrystalline cobalt ferrite and nickel ferrite thin films grown on silicon and platinized silicon substrates was measured under a DC magnetic bias. The experimental setup and the derivation of the magnetostriction constant from the experimentally measured deflection values are discussed. The magnetostriction values derived using force and bending moment balances were compared with that derived from an industry standard relationship. In addition, we corroborate our approach by comparing the values derived from bending theory calculations of magnetically induced torque to those from measurements using Vibrating Sample Magnetometer (VSM). At high DC magnetic field bias, the magnitude of magnetization calculated from the measured magnetostriction was found to match the measured magnetization by VSM. - Highlights: • Laser Doppler vibrometry based technique to measure magnetostriction in thin films. • Strain induced by an AC magnetic field under a DC magnetic bias. • Picometer level deflections in polycrystalline cobalt and nickel ferrite thin films

  19. Glue Film Thickness Measurements by Spectral Reflectance

    Energy Technology Data Exchange (ETDEWEB)

    B. R. Marshall

    2010-09-20

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 μm, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  20. Glue Film Thickness Measurements by Spectral Reflectance

    International Nuclear Information System (INIS)

    Marshall, B.R.

    2010-01-01

    Spectral reflectance was used to determine the thickness of thin glue layers in a study of the effect of the glue on radiance and reflectance measurements of shocked-tin substrates attached to lithium fluoride windows. Measurements based on profilometry of the components were found to be inaccurate due to flatness variations and deformation of the tin substrate under pressure during the gluing process. The accuracy of the spectral reflectance measurements were estimated to be ±0.5 (micro)m, which was sufficient to demonstrate a convincing correlation between glue thickness and shock-generated light.

  1. A software system for measuring bubble chamber films on line

    International Nuclear Information System (INIS)

    Blomqvist, G.; Hulth, P.O.

    1974-01-01

    A system has been developed for measuring bubble chamber films on line. This report describes the computer program used in the on-line system. The program guides the operator during the measurements, makes on-line control of the measurement data and produces output data on magnetic tape in a format suitable as input for the geometry programme THRESH. The on-line program is coded in the assembly language OSAS-A used for CDC 8090 computers. (Auth.)

  2. Measurement error in longitudinal film badge data

    CERN Document Server

    Marsh, J L

    2002-01-01

    Initial logistic regressions turned up some surprising contradictory results which led to a re-sampling of Sellafield mortality controls without the date of employment matching factor. It is suggested that over matching is the cause of the contradictory results. Comparisons of the two measurements of radiation exposure suggest a strongly linear relationship with non-Normal errors. A method has been developed using the technique of Regression Calibration to deal with these in a case-control study context, and applied to this Sellafield study. The classical measurement error model is that of a simple linear regression with unobservable variables. Information about the covariates is available only through error-prone measurements, usually with an additive structure. Ignoring errors has been shown to result in biased regression coefficients, reduced power of hypothesis tests and increased variability of parameter estimates. Radiation is known to be a causal factor for certain types of leukaemia. This link is main...

  3. Determining Confounding Sensitivities In Eddy Current Thin Film Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gros, Ethan; Udpa, Lalita; Smith, James A.; Wachs, Katelyn

    2016-07-01

    Determining Confounding Sensitivities In Eddy Current Thin Film Measurements Ethan Gros, Lalita Udpa, Electrical Engineering, Michigan State University, East Lansing MI 48824 James A. Smith, Experiment Analysis, Idaho National Laboratory, Idaho Falls ID 83415 Eddy current (EC) techniques are widely used in industry to measure the thickness of non-conductive films on a metal substrate. This is done using a system whereby a coil carrying a high-frequency alternating current is used to create an alternating magnetic field at the surface of the instrument's probe. When the probe is brought near a conductive surface, the alternating magnetic field will induce ECs in the conductor. The substrate characteristics and the distance of the probe from the substrate (the coating thickness) affect the magnitude of the ECs. The induced currents load the probe coil affecting the terminal impedance of the coil. The measured probe impedance is related to the lift off between coil and conductor as well as conductivity of the test sample. For a known conductivity sample, the probe impedance can be converted into an equivalent film thickness value. The EC measurement can be confounded by a number of measurement parameters. It is the goal of this research to determine which physical properties of the measurement set-up and sample can adversely affect the thickness measurement. The eddy current testing is performed using a commercially available, hand held eddy current probe (ETA3.3H spring loaded eddy probe running at 8 MHz) that comes with a stand to hold the probe. The stand holds the probe and adjusts the probe on the z-axis to help position the probe in the correct area as well as make precise measurements. The signal from the probe is sent to a hand held readout, where the results are recorded directly in terms of liftoff or film thickness. Understanding the effect of certain factors on the measurements of film thickness, will help to evaluate how accurate the ETA3.3H spring

  4. Research on Forming Mechanisms and Controlling Measurements for Surface Light Spot Defects of Galvanizing Steel Coils for Automobile Use

    Science.gov (United States)

    Guangmin, Wei; Haiyan, Sun; Jianqiang, Shi; Lianxuan, Wang; Haihong, Wu

    When producing high surface quality galvanizing steel coils for automobile use, there are always many light spots on the surface since Hansteel CGL No.1 has been put into operation. The defect samples were analyzed by SEM and EDS. The result shows that cause for light spot is not only one. There are more Mn and P in high strength auto sheet, which can result in difficulty to be cleaned off the oxide on the hot rolled coils, so the defects coming. This is why the defects come with high strength auto sheet. When coils galvanized, the defects can't be covered up. To the contrary, the defects will be more obvious when zinc growing on the surface. And sometimes zinc or residue can adhere to work rolls when strips passing through SPM. The deposits then press normal coating. So the light spots come more. When the defect comes from pressing, there is no defect on steel base. The causation is found and measures were taken including high pressure cleaning equipments adopted. Result shows that the defects disappeared.

  5. Measurement of thick film adhesion by an impact separation technique

    International Nuclear Information System (INIS)

    Snowden, W.E.; Aksay, I.A.

    1981-01-01

    The purpose of this study was to utilize a dynamic loading (impact separation) technique to determine absolute values for the force of adhesion required to separate a substrate/film interface into its two joining components. A principal advantage of the technique is that the force required for adhesive failure is applied directly at the interface by stress waves of relatively low amplitude, not by application of a force to the free surface of the film. Critical impact velocities required for separation of thick films from two types of substrates were measured. Values for force of adhesion were then calculated using a complex finite-difference computer code developed for analysis of a variety of dynamic problems

  6. Imaging and thickness measurement of amorphous intergranular films using TEM

    International Nuclear Information System (INIS)

    MacLaren, I.

    2004-01-01

    Fresnel fringe analysis is shown to be unreliable for grain boundaries in yttrium-doped alumina: the determined thicknesses do not agree well with those measured from high resolution transmission electron microscopy (HRTEM), the asymmetry between under- and overfocus is very large, and Fresnel fringes are sometimes shown at boundaries which contain no amorphous film. An alternative approach to the analysis of HRTEM images of grain boundary films is demonstrated: Fourier filtering is used to remove the lattice fringes from the image thereby significantly enhancing the visibility of the intergranular films. The apparent film thickness shows a discrepancy between measurements from the original HRTEM image and the filtered image. It was shown that fringe delocalisation and diffuseness of the amorphous/crystalline interfaces will lead to a significant underestimate of the thickness in unprocessed HRTEM images. In contrast to this, the average thickness can be much more accurately measured from the Fourier-filtered image, provided the boundary is oriented accurately edge-on

  7. [Rescue service: initial measures on the spot and in hospital (author's transl)].

    Science.gov (United States)

    1975-11-01

    Improvement of any rescue service is inextricably bound up with the provision of optimal conditions with regard to first aid at the site of the accident, transport and immediate care in hospital. Only properly trained and experienced doctors are able to take appropriate life-saving action on the spot. Therefore ane should aim at getting the doctor to the site of the accident by helicopter or by ambulance as fast as possible. After immediate life-saving action has been taken, the various injuries should also be provisionally attended to as well as possible. The entire scope of these problems was discussed at the refresher course.

  8. Spotting the earth connection and short circuits between the electric conductors, using D.C. bridges for resistance measurements

    Science.gov (United States)

    Popa, I.; Popa, G. N.; Deaconu, S. I.; Iagăr, A.

    2015-06-01

    The paper establishes the necessary connections meant to spot the earth connections and short circuits between the conductors of a power line, using the DC bridges meant for measuring resistances between conductors at the ends of the power line. Since it is a relative method, it imposes an exact knowledge of the faulty power line setting. For values of the resistances measured between the conductors of the power line having over 1Ω at one end, the measurement will be carried out with a Wheatstone bridge, and for values below 1Ω with a Thomson bridge. In order to accurately determine the place of the fault, it measured the distances from the end of the line up to the fault and then we performed a correction calculation for this distance.

  9. Measurement of lower hybrid hot spots using a retarding field analyzer in Tore Supra

    Czech Academy of Sciences Publication Activity Database

    Gunn, J. P.; Petržílka, Václav; Ekedahl, A.; Fuchs, Vladimír; Gauthier, E.; Goniche, M.; Kočan, M.; Pascal, J.Y.; Saint Laurent, F.

    390-391, č. 1 (2009), s. 904-906 ISSN 0022-3115. [International Conference on Plasma-Surface Interactions in Controlled Fusion Devices/18th./. Toledo, 26.05.2008-30.5.2008] R&D Projects: GA ČR GA202/07/0044 Institutional research plan: CEZ:AV0Z20430508 Keywords : Lower Hybrid * hot spots * ELECTRONS * POWER Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.933, year: 2009 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TXN-4VG7MW6-7&_user=6542793&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000070123&_version=1&_urlVersion=0&_userid=6542793&md5=944ed4d95df86a149fa36439db6215db

  10. Simultaneous measurement of 25 inflammatory markers and neurotrophins in neonatal dried blood spots by immunoassay with xMAP technology

    DEFF Research Database (Denmark)

    Skogstrand, Kristin; Thorsen, Poul; Nørgaard-Pedersen, Bent

    2005-01-01

    BACKGROUND: Inflammatory reactions and other events in early life may be part of the etiology of late-onset diseases, including cerebral palsy, autism, and type 1 diabetes. Most neonatal screening programs for congenital disorders are based on analysis of dried blood spot samples (DBSS), and stored...... on flowmetric Luminex xMAP technology to measure inflammatory markers and neutrophins in DBSS. RESULTS: The high-capacity 25-plex multianalyte method measured 23 inflammatory and trophic cytokines, triggering receptor expressed on myeloid cells-1 (TREM-1), and C-reactive protein in two 3.2-mm punches from DBSS....... It also measured 26 cytokines and TREM-1 in serum. Standards Recovery in the 25-plex method were 90%-161% (mean, 105%). The low end of the working range for all 25 analytes covered concentrations found in DBSS from healthy newborns. Mean recovery of exogenous analytes added at physiologic concentrations...

  11. Parched elasto hydrodynamic lubrication film thickness measurement in an instrument ball bearing

    Science.gov (United States)

    Kingsbury, E.; Schritz, B.; Prahl, J.

    1988-01-01

    Parched Elasto Hydrodynamic Lubricant (PEHL) film thickness in a large instrument ball bearing is measured by electrical capacitance across its ball set. Correlation is shown between changes in film thickness and changes in Basic Speed Ratio (BSR) measured at the same time. BSR is confirmed as a sensitive, non-intrusive measure of transients in film thickness in a real bearing.

  12. IP-10 measured by Dry Plasma Spots as biomarker for therapy responses in Mycobacterium Tuberculosis infection.

    Science.gov (United States)

    Tonby, Kristian; Ruhwald, Morten; Kvale, Dag; Dyrhol-Riise, Anne Ma

    2015-03-18

    Tuberculosis (TB) has huge impact on human morbidity and mortality and biomarkers to support rapid TB diagnosis and ensure treatment initiation and cure are needed, especially in regions with high prevalence of multi-drug resistant TB. Soluble interferon gamma inducible protein 10 (IP-10) analyzed from dry plasma spots (DPS) has potential as an immunodiagnostic marker in TB infection. We analyzed IP-10 levels in plasma directly and extracted from DPS in parallel by ELISA from 34 clinically well characterized patients with TB disease before and throughout 24 weeks of effective anti-TB chemotherapy. We detected a significant decline of IP-10 levels in both plasma and DPS already after two weeks of therapy with good correlation between the tests. This was observed both in pulmonary and extrapulmonary TB. In conclusion, plasma IP-10 may serve as an early biomarker for anti-TB chemotherapy responses and the IP-10 DPS method has potential to be developed into a point-of care test for use in resource-limited settings. Further studies must be performed to validate the use of IP-10 DPS in TB high endemic countries.

  13. A Nondestructive Evaluation Method: Measuring the Fixed Strength of Spot-Welded Joint Points by Surface Electrical Resistivity.

    Science.gov (United States)

    Shimamoto, Akira; Yamashita, Keitaro; Inoue, Hirofumi; Yang, Sung-Mo; Iwata, Masahiro; Ike, Natsuko

    2013-04-01

    Destructive tests are generally applied to evaluate the fixed strength of spot-welding nuggets of zinc-plated steel (which is a widely used primary structural material for automobiles). These destructive tests, however, are expensive and time-consuming. This paper proposes a nondestructive method for evaluating the fixed strength of the welded joints using surface electrical resistance. A direct current nugget-tester and probes have been developed by the authors for this purpose. The proposed nondestructive method uses the relative decrease in surface electrical resistance, α . The proposed method also considers the effect of the corona bond. The nugget diameter is estimated by two factors: R Quota , which is calculated from variation of resistance, and a constant that represents the area of the corona bond. Since the maximum tensile strength is correlated with the nugget diameter, it can be inferred from the estimated nugget diameter. When appropriate measuring conditions for the surface electrical resistance are chosen, the proposed method can effectively evaluate the fixed strength of the spot-welded joints even if the steel sheet is zinc-plated.

  14. Measurement of radiation and temperature of cathod spots in excimer laser discharge; Ekishima reza reiki hodennai ni fukumareru inkyoku kiten no kogakuteki kansoku to ondo no sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Minamitani, Y.; Nakatani, H. [Mitsubishi Electric Corp., Tokyo (Japan)

    1996-08-20

    Excimer laser is used in various fields such as luminous source for steppers, annealing treatment, ablation process, nuclear fusion and so on. In this paper, the radiation timing and gas temperature of cathode spots, streamer discharges and glow discharges in KrF excimer are measured by observing the radiating spectra thereof. The following conclusions are obtained from the results of the present study. Cathode spots begin to radiate at about 20ns after the discharge initiation, then the first and second radiation peaks are observed respectively when the discharge current reversing after passing zero point and the reserved discharged current approaching zero point. Streamer discharge makes flashover between electrodes at the second radiation peak of cathode spots, while the glow discharges almost disappear when streamer discharges occurring. The temperatures of cathode spots and glow discharge as 5500K and 2600K respectively are almost constant and independent upon the discharging voltage of laser. 14 refs., 12 figs.

  15. Dried Blood Spots for Measuring Vibrio cholerae-specific Immune Responses.

    Directory of Open Access Journals (Sweden)

    Anita S Iyer

    2018-01-01

    Full Text Available Vibrio cholerae causes over 2 million cases of cholera and 90,000 deaths each year. Serosurveillance can be a useful tool for estimating the intensity of cholera transmission and prioritizing populations for cholera control interventions. Current methods involving venous blood draws and downstream specimen storage and transport methods pose logistical challenges in most settings where cholera strikes. To overcome these challenges, we developed methods for determining cholera-specific immune responses from dried blood spots (DBS.As conventional vibriocidal assay methods were unsuitable for DBS eluates from filter paper, we adopted a drop-plate culture method. We show that DBS collected from volunteers in South Sudan, and stored for prolonged periods in field conditions, retained functional vibriocidal antibodies, the titers of which correlated with paired serum titers determined by conventional spectrophotometric methods (r = 0.94, p = 0.00012. We also showed that eluates from DBS Serum Separator cards could be used with conventional spectrophotometric vibriocidal methods, and that they correlated with paired serum at a wide range of titers (r = 0.96, p<0.0001. Similarly, we used ELISA methods to show that V. cholerae O-specific polysaccharide antibody responses from DBS eluates correlated with results from paired serum for IgG (r = 0.85, p = 0.00006, IgM (r = 0.79, p = 0.00049 and IgA (r = 0.73, p = 0.0019, highlighting its potential for use in determination of isotype-specific responses. Storage of DBS cards at a range of temperatures did not change antibody responses.In conclusion, we have developed and demonstrated a proof-of-concept for assays utilizing DBS for assessing cholera-specific immune responses.

  16. Substrate heating measurements in pulsed ion beam film deposition

    Energy Technology Data Exchange (ETDEWEB)

    Olson, J.C.; Davis, H.A.; Rej, D.J.; Waganaar, W.J. [Los Alamos National Lab., NM (United States); Tallant, D.R. [Cornell Univ., Ithaca, NY (United States). Materials Science and Engineering Dept.; Thompson, M.O. [Sandia National Labs., Albuquerque, NM (United States)

    1995-05-01

    Diamond-like Carbon (DLC) films have been deposited at Los Alamos National Laboratory by pulsed ion beam ablation of graphite targets. The targets were illuminated by an intense beam of hydrogen, carbon, and oxygen ions at a fluence of 15-45 J/cm{sup 2}. Ion energies were on the order of 350 keV, with beam current rising to 35 kA over a 400 ns ion current pulse. Raman spectra of the deposited films indicate an increasing ratio of sp{sup 3} to sp{sup 2} bonding as the substrate is moved further away from the target and further off the target normal. Using a thin film platinum resistor at varying positions, we have measured the heating of the substrate surface due to the kinetic energy and heat of condensation of the ablated material. This information is used to determine if substrate heating is responsible for the lack of DLC in positions close to the target and near the target normal. Latest data and analysis will be presented.

  17. The reliability of head film measurements. 3. Tracing superimposition.

    Science.gov (United States)

    Baumrind, S; Miller, D; Molthen, R

    1976-12-01

    The superimposition of tracings from lateral skull x-ray films taken at different timepoints is an important method for assessing developmental and treatment changes through time. The usefulness of the data derived is, however, limited by the fact that the physical act of superimposing tracings is performed with some error. The magnitudes of error for superimpositions on different "planes" have not been amenable to quantitation by previously available methods. Using newly developed computer-aided techniques, we have been able to quantitate both the primary errors of tracing superimposition and the associated secondary landmark displacements for four conventionally employed anatomic reference "planes". For each reference "plane," twenty-five independent film pairs were examined independently by each of four judges. Therefore, 100 acts of tracing superimposition were available for each reference "plane." Output data are presented which appear to support the conclusion that measurement errors in tracing superimposition are a consequential factor affecting the confidence which should be placed in head film comparisons, particularly with regard to individual cases. Some consequences of this conclusion with respect to growth prediction and to the evaluation of treatment effects are considered.

  18. Determining the Elastic Modulus of Compliant Thin Films Supported on Substrates from Flat Punch Indentation Measurements

    Science.gov (United States)

    M.J. Wald; J.M. Considine; K.T. Turner

    2013-01-01

    Instrumented indentation is a technique that can be used to measure the elastic properties of soft thin films supported on stiffer substrates, including polymer films, cellulosic sheets, and thin layers of biological materials. When measuring thin film properties using indentation, the effect of the substrate must be considered. Most existing models for determining the...

  19. Effects of blood sample handling procedures on measurable inflammatory markers in plasma, serum and dried blood spot samples

    DEFF Research Database (Denmark)

    Skogstrand, K.; Thorsen, P.; Vogel, I.

    2008-01-01

    increased when blood samples were stored for a period of time before the centrifugation, for certain cytokines more than 1000 fold compared to serum and plasma isolated and frozen immediately after venepuncture. The concentrations in serum generally increased more than in plasma. The measurable......The interests in monitoring inflammation by immunoassay determination of blood inflammatory markers call for information on the stability of these markers in relation to the handling of blood samples. The increasing use of stored biobank samples for such ventures that may have been collected...... and stored for other purposes, justifies the study hereof. Blood samples were stored for 0, 4, 24, and 48 h at 4 degrees C, room temperature (RT), and at 35 degrees C, respectively, before they were separated into serum or plasma and frozen. Dried blood spot samples (DBSS) were stored for 0, 1, 2, 3, 7...

  20. Finite-element analysis of the deformation of thin Mylar films due to measurement forces.

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Michael Sean; Robinson, Alex Lockwood; Tran, Hy D.

    2012-01-01

    Significant deformation of thin films occurs when measuring thickness by mechanical means. This source of measurement error can lead to underestimating film thickness if proper corrections are not made. Analytical solutions exist for Hertzian contact deformation, but these solutions assume relatively large geometries. If the film being measured is thin, the analytical Hertzian assumptions are not appropriate. ANSYS is used to model the contact deformation of a 48 gauge Mylar film under bearing load, supported by a stiffer material. Simulation results are presented and compared to other correction estimates. Ideal, semi-infinite, and constrained properties of the film and the measurement tools are considered.

  1. Real-time micro-vibration multi-spot synchronous measurement within a region based on heterodyne interference

    Science.gov (United States)

    Lan, Ma; Xiao, Wen; Chen, Zonghui; Hao, Hongliang; Pan, Feng

    2018-01-01

    Real-time micro-vibration measurement is widely used in engineering applications. It is very difficult for traditional optical detection methods to achieve real-time need in a relatively high frequency and multi-spot synchronous measurement of a region at the same time,especially at the nanoscale. Based on the method of heterodyne interference, an experimental system of real-time measurement of micro - vibration is constructed to satisfy the demand in engineering applications. The vibration response signal is measured by combing optical heterodyne interferometry and a high-speed CMOS-DVR image acquisition system. Then, by extracting and processing multiple pixels at the same time, four digital demodulation technique are implemented to simultaneously acquire the vibrating velocity of the target from the recorded sequences of images. Different kinds of demodulation algorithms are analyzed and the results show that these four demodulation algorithms are suitable for different interference signals. Both autocorrelation algorithm and cross-correlation algorithm meet the needs of real-time measurements. The autocorrelation algorithm demodulates the frequency more accurately, while the cross-correlation algorithm is more accurate in solving the amplitude.

  2. Age Spots

    Science.gov (United States)

    ... for Every Season How to Choose the Best Skin Care Products In This Section Dermatologic Surgery What is dermatologic ... for Every Season How to Choose the Best Skin Care Products Age Spots Treatment Options Learn more about treatment ...

  3. Accuracy of stress measurement by Laue microdiffraction (Laue-DIC method): the influence of image noise, calibration errors and spot number.

    Science.gov (United States)

    Zhang, F G; Bornert, M; Petit, J; Castelnau, O

    2017-07-01

    Laue microdiffraction, available at several synchrotron radiation facilities, is well suited for measuring the intragranular stress field in deformed materials thanks to the achievable submicrometer beam size. The traditional method for extracting elastic strain (and hence stress) and lattice orientation from a microdiffraction image relies on fitting each Laue spot with an analytical function to estimate the peak position on the detector screen. The method is thus limited to spots exhibiting ellipsoidal shapes, thereby impeding the study of specimens plastically deformed. To overcome this difficulty, the so-called Laue-DIC method introduces digital image correlation (DIC) for the evaluation of the relative positions of spots, which can thus be of any shape. This paper is dedicated to evaluating the accuracy of this Laue-DIC method. First, a simple image noise model is established and verified on the data acquired at beamline BM32 of the European Synchrotron Radiation Facility. Then, the effect of image noise on errors on spot displacement measured by DIC is evaluated by Monte Carlo simulation. Finally, the combined effect of the image noise, calibration errors and the number of Laue spots used for data treatment is investigated. Results in terms of the uncertainty of stress measurement are provided, and various error regimes are identified.

  4. 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)

  5. Magnetic Field Measurements of the Spotted Yellow Dwarf DE Boo During 2001-2004

    Science.gov (United States)

    Plachinda, S.; Baklanova, D.; Butkovskaya, V.; Pankov, N.

    2017-06-01

    Spectropolarimetric observations of DE Boo have been performed at Crimean astrophysical observatory during 18 nights in 2001-2004. We present the result of the longitudinal magnetic field measurements on this star. The magnetic field varies from +44 G to -36 G with mean Standard Error (SE) of 8.2 G. For full array of the magnetic field measurements the difference between experimental errors and Monte Carlo errors is not statistically significant.

  6. A 4-spot time-of-flight anemometer for small centrifugal compressor velocity measurements

    Science.gov (United States)

    Wernet, Mark P.; Skoch, Gary J.

    1992-01-01

    The application of laser anemometry techniques in turbomachinery facilities is a challenging dilemma requiring an anemometer system with special qualities. Here, we describe the use of a novel laser anemometry technique applied to a small 4.5 kg/s, 4:1 pressure ratio centrifugal compressor. Sample velocity profiles across the blade pitch are presented for a single location along the rotor. The results of the intra-blade passage velocity measurements will ultimately be used to verify CFD 3-D viscous code predictions.

  7. Random spot urine protein to creatinine ratio is a reliable measure of proteinuria in lupus nephritis in Koreans.

    Science.gov (United States)

    Choi, In Ah; Park, Jin Kyun; Lee, Eun Young; Song, Yeong Wook; Lee, Eun Bong

    2013-01-01

    The accurate assessment of proteinuria is critical for the management of lupus nephritis. Measuring the protein to creatinine (P/C) ratio in random spot urine (RSU) samples has been introduced as an alternative to the 24-hour (24h) urine collection method. However, it remains unclear as to whether the RSU P/C ratio is reliable for assessing lupus nephritis (LN) in routine clinical practice. In total, 275 pairs of 24h urine and RSU samples from 102 patients with biopsy-proven LN were analysed. The correlation and concordance between the P/C ratios in the two sample types were assessed by Pearson or Spearman correlation and intra-class correlation coefficient (ICC) using mixed models for repeated measurements, respectively. The mean 24h urine P/C ratio was 3.2 ± 4.9. Overall, RSU P/C ratio correlated strongly with the 24h urine P/C ratio (r=0.944, purine and RSU P/C ratio in the range of 0.5 to 3 was good (r=0.720, p1.0 may prompt directly to a renal biopsy, whereas RSU P/C ratio between 0.5-1.0 should be followed by a confirmatory 24h urine collection.

  8. Thick Films acoustic sensors devoted to MTR environment measurements. Thick Films acoustic sensors devoted to Material Testing Reactor environment measurements

    International Nuclear Information System (INIS)

    Very, F.; Rosenkrantz, E.; Combette, P.; Ferrandis, J.Y.; Fourmentel, D.; Destouches, C.; Villard, J.F.

    2015-01-01

    The development of advanced instrumentation for in-pile experiments in Material Testing Reactor constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. An acoustic method for fission gas release detection was tested with success during a first experiment called REMORA 3 in 2010 and 2011, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. This experiment was lead at OSIRIS reactor (CEA Saclay, France). The maximal temperature on the sensor during the irradiation was about 150 deg. C. In this paper we present a thick film transducer produce by screen printing process. The screen printing of piezoelectric offers a wide range of possible applications for the development of acoustic sensors and piezoelectric structure for measurements in high temperature environment. We firstly produced a Lead Zirconate Titanate (PZT) based paste composed of Pz27 powder from Ferroperm, CF7575 glass, and organic solvent ESL 400. Likewise a Bismuth Titanate based paste synthesized in our laboratory was produced. With these inks we produced thick film up to 130 μm by screen printing process. Material properties characterizations of these thick-film resonators are essential for device design and applications. The piezoelectric coefficients d33 and pyro-electric P(T) coefficient are investigated. The highest P(T) and d33 are respectively 80 μC.m -2 .K -1 and 130 μC.N -1 for the PZT transducer -which validates the fabrication process-. In view of the development of this transducer oriented for high temperature and irradiation environment, we investigated the electrical properties of the transducers for different ranges of frequencies and temperature - from 20 Hz up to 40 MHz between 30 and 400 deg. C. We highlight the evolution of the impedance response and piezoelectric parameters of screen printed piezoelectric structures on alumina. Shortly an irradiation will be realized in order to

  9. Thick Films acoustic sensors devoted to MTR environment measurements. Thick Films acoustic sensors devoted to Material Testing Reactor environment measurements

    Energy Technology Data Exchange (ETDEWEB)

    Very, F.; Rosenkrantz, E.; Combette, P.; Ferrandis, J.Y. [University Montpellier, IES, UMR 5214, F-34000, Montpellier (France); CNRS, IES, UMR 5214, F-34000, Montpellier (France); Fourmentel, D.; Destouches, C.; Villard, J.F. [CEA, DEN, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St Paul lez Durance (France)

    2015-07-01

    The development of advanced instrumentation for in-pile experiments in Material Testing Reactor constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. An acoustic method for fission gas release detection was tested with success during a first experiment called REMORA 3 in 2010 and 2011, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. This experiment was lead at OSIRIS reactor (CEA Saclay, France). The maximal temperature on the sensor during the irradiation was about 150 deg. C. In this paper we present a thick film transducer produce by screen printing process. The screen printing of piezoelectric offers a wide range of possible applications for the development of acoustic sensors and piezoelectric structure for measurements in high temperature environment. We firstly produced a Lead Zirconate Titanate (PZT) based paste composed of Pz27 powder from Ferroperm, CF7575 glass, and organic solvent ESL 400. Likewise a Bismuth Titanate based paste synthesized in our laboratory was produced. With these inks we produced thick film up to 130 μm by screen printing process. Material properties characterizations of these thick-film resonators are essential for device design and applications. The piezoelectric coefficients d33 and pyro-electric P(T) coefficient are investigated. The highest P(T) and d33 are respectively 80 μC.m{sup -2}.K{sup -1} and 130 μC.N{sup -1} for the PZT transducer -which validates the fabrication process-. In view of the development of this transducer oriented for high temperature and irradiation environment, we investigated the electrical properties of the transducers for different ranges of frequencies and temperature - from 20 Hz up to 40 MHz between 30 and 400 deg. C. We highlight the evolution of the impedance response and piezoelectric parameters of screen printed piezoelectric structures on alumina. Shortly an irradiation will be realized in

  10. Measuring and overcoming limits of the Saffman-Delbrück model for soap film viscosities.

    Science.gov (United States)

    Vivek, Skanda; Weeks, Eric R

    2015-01-01

    We observe tracer particles diffusing in soap films to measure the two-dimensional (2D) viscous properties of the films. Saffman-Delbrück type models relate the single-particle diffusivity to parameters of the film (such as thickness h) for thin films, but the relation breaks down for thicker films. Notably, the diffusivity is faster than expected for thicker films, with the crossover at h/d = 5.2 ± 0.9 using the tracer particle diameter d. This indicates a crossover from purely 2D diffusion to diffusion that is more three-dimensional. We demonstrate that measuring the correlations of particle pairs as a function of their separation overcomes the limitations of the Saffman-Delbrück model and allows one to measure the viscosity of a soap film for any thickness.

  11. Dielectric Measurements on Sol-Gel Derived Titania Films

    Science.gov (United States)

    Capan, Rifat; Ray, Asim K.

    2017-11-01

    Alternating current (AC) impedance measurements were performed on 37 nm thick nanostructured sol-gel derived anatase titania films on ultrasonically cleaned (100) p-silicon substrates at temperatures T ranging from 100 K to 300 K over a frequency range between 20 Hz and 1 MHz. The frequency-dependent behavior of the AC conductivity σ ac( f, T) obeys the universal power law, and the values of the effective hopping barrier and hopping distance were found to be 0.79 eV and 6.7 × 10-11 m from an analysis due to the correlated barrier-hopping model. The dielectric relaxation was identified as a thermally activated non-Debye process involving an activation energy of 41.5 meV.

  12. A new attempt of measurement film thickness by x-ray diffractometry

    International Nuclear Information System (INIS)

    Kosaka, Masao; Kobayashi, Hideo

    1987-01-01

    In order to make film thickness measurements independent from the property or the structure of the film materials or the substrate, it is needed to adopt instead of directly utilizing the X-ray diffraction intensity, or attenuation information obtained from the substrate or film material, other new methods for measurement. Among the information obtained by X-ray diffraction, if intensity is excluded, others are F.W.H.M. and diffraction angle, only. If it is possible to investigate the film thickness dependency of the diffraction angle, it should be possible to measure the film thickness by diffraction angle. However, since diffraction angle has no film thickness dependency, it cannot be used directly for measurement. However, if we consider the principle of the X-ray diffractometer method, although it may be very slight, the substrate will be eccentric from the revolving center of the goniometer on account of the thickness of the film. If eccentricity occurs, this will cause changes in the diffraction angle. If we set the radius of the goniometer as R, diffraction angle θ, and the eccentricity from the revolving center of the specimen surface X, the deflection angle Δ2θ of 2θ may be expressed by Δ2θ = -2X · COSθ/R Thus, if X is caused by the film thickness, and by measuring the Δ2θ, it will be possible to measure the film thickness. As a result of the experiment, it was found that X-ray diffraction method can be used for the measurement of the film thickness of a few microns or above by utilizing the eccentricity caused by the film thickness. Especially it has the advantage of being able to measure thick films that X-rays will not penetrate, without being influenced by the chemical structure of the film or the substrates. (author)

  13. Surface roughness characterization of Al-doped zinc oxide thin films using rapid optical measurement

    Science.gov (United States)

    Kuo, Chil-Chyuan

    2011-07-01

    Transparent conductive oxide thin films have been widely investigated in photoelectric devices such as flat panel display (FPD) and solar cells. Al-doped zinc oxide (AZO) thin films have been widely employed in FPD. Measuring the surface roughness of AZO thin films is important before the manufacturing of photoelectric device using AZO thin films because surface roughness of AZO thin films will significantly affect the performance of photoelectric device. Traditional methods to measure surface roughness of AZO thin films are scanning electron microscopy and atomic force microscopy. The disadvantages of these approaches include long lead time and slow measurement speed. To solve this problem, an optical inspection system for rapid measurement of the surface roughness of AZO thin films is developed in this study. It is found that the incident angle of 60° is a good candidate to measure the surface roughness of AZO thin films. Based on the trend equation y=-3.6483 x+2.1409, the surface roughness of AZO thin films ( y) can be directly deduced from the peak power density ( x) using the optical inspection system developed. The maximum measurement-error rate of the optical inspection system developed is less than 8.7%.The saving in inspection time of the surface roughness of AZO thin films is up to 83%.

  14. Smoking in film in New Zealand: measuring risk exposure.

    Science.gov (United States)

    Gale, Jesse; Fry, Bridget; Smith, Tara; Okawa, Ken; Chakrabarti, Anannya; Ah-Yen, Damien; Yi, Jesse; Townsend, Simon; Carroll, Rebecca; Stockwell, Alannah; Sievwright, Andrea; Dew, Kevin; Thomson, George

    2006-10-04

    Smoking in film is a risk factor for smoking uptake in adolescence. This study aimed to quantify exposure to smoking in film received by New Zealand audiences, and evaluate potential interventions to reduce the quantity and impact of this exposure. The ten highest-grossing films in New Zealand for 2003 were each analysed independently by two viewers for smoking, smoking references and related imagery. Potential interventions were explored by reviewing relevant New Zealand legislation, and scientific literature. Seven of the ten films contained at least one tobacco reference, similar to larger film samples. The majority of the 38 tobacco references involved characters smoking, most of whom were male. Smoking was associated with positive character traits, notably rebellion (which may appeal to adolescents). There appeared to be a low threshold for including smoking in film. Legislative or censorship approaches to smoking in film are currently unlikely to succeed. Anti-smoking advertising before films has promise, but experimental research is required to demonstrate cost effectiveness. Smoking in film warrants concern from public health advocates. In New Zealand, pre-film anti-smoking advertising appears to be the most promising immediate policy response.

  15. Smoking in film in New Zealand: measuring risk exposure

    Directory of Open Access Journals (Sweden)

    Stockwell Alannah

    2006-10-01

    Full Text Available Abstract Background Smoking in film is a risk factor for smoking uptake in adolescence. This study aimed to quantify exposure to smoking in film received by New Zealand audiences, and evaluate potential interventions to reduce the quantity and impact of this exposure. Methods The ten highest-grossing films in New Zealand for 2003 were each analysed independently by two viewers for smoking, smoking references and related imagery. Potential interventions were explored by reviewing relevant New Zealand legislation, and scientific literature. Results Seven of the ten films contained at least one tobacco reference, similar to larger film samples. The majority of the 38 tobacco references involved characters smoking, most of whom were male. Smoking was associated with positive character traits, notably rebellion (which may appeal to adolescents. There appeared to be a low threshold for including smoking in film. Legislative or censorship approaches to smoking in film are currently unlikely to succeed. Anti-smoking advertising before films has promise, but experimental research is required to demonstrate cost effectiveness. Conclusion Smoking in film warrants concern from public health advocates. In New Zealand, pre-film anti-smoking advertising appears to be the most promising immediate policy response.

  16. Dark Spots

    Science.gov (United States)

    2006-01-01

    Dark spots (left) and 'fans' appear to scribble dusty hieroglyphics on top of the Martian south polar cap in two high-resolution Mars Global Surveyor, Mars Orbiter Camera images taken in southern spring. Each image is about 3-kilometers wide (2-miles).

  17. Microfabricated Thin Film Impedance Sensor & AC Impedance Measurements

    Science.gov (United States)

    Yu, Jinsong; Liu, Chung-Chiun

    2010-01-01

    Thin film microfabrication technique was employed to fabricate a platinum based parallel-electrode structured impedance sensor. Electrochemical impedance spectroscopy (EIS) and equivalent circuit analysis of the small amplitude (±5 mV) AC impedance measurements (frequency range: 1 MHz to 0.1 Hz) at ambient temperature were carried out. Testing media include 0.001 M, 0.01 M, 0.1 M NaCl and KCl solutions, and alumina (∼3 μm) and sand (∼300 μm) particulate layers saturated with NaCl solutions with the thicknesses ranging from 0.6 mm to 8 mm in a testing cell, and the results were used to assess the effect of the thickness of the particulate layer on the conductivity of the testing solution. The calculated resistances were approximately around 20 MΩ, 4 MΩ, and 0.5 MΩ for 0.001 M, 0.01 M, and 0.1 M NaCl solutions, respectively. The presence of the sand particulates increased the impedance dramatically (6 times and 3 times for 0.001 M and 0.1 M NaCl solutions, respectively). A cell constant methodology was also developed to assess the measurement of the bulk conductivity of the electrolyte solution. The cell constant ranged from 1.2 to 0.8 and it decreased with the increase of the solution thickness. PMID:22219690

  18. Influence of test capacitor features on piezoelectric and dielectric measurement of ferroelectric films.

    Science.gov (United States)

    Wang, Zhihong; Lau, Gih Keong; Zhu, Weiguang; Chao, Chen

    2006-01-01

    This paper presents both theoretical and numerical analyses of the piezoelectric and dielectric responses of a highly idealized film-on-substrate system, namely, a polarized ferroelectric film perfectly bonded to an elastic silicon substrate. It shows that both effective dielectric and piezoelectric properties of the films change with the size and configuration of the test capacitor. There exists a critical electrode size that is smaller than the diameter of the commonly used substrate. The effective film properties converge to their respective constrained values as capacitor size increases to the critical size. If capacitor size is smaller than the critical size, the surface displacement at the top electrode deviates from the net thickness change in response to an applied voltage because the film is deformable at the film/substrate interface. The constrained properties of the films depend only on those of bulk ferroelectrics but are independent of film thickness and substrate properties. The finding of the critical capacitor size together with analytical expressions of the constrained properties makes it possible to realize consistent measurement of piezoelectric and dielectric properties of films. A surface scanning technique is recommended to measure the profile of piezoresponses of the film so that the constrained properties of the film can be identified accurately.

  19. Metallic thin film depth measurements by X-ray microanalysis

    International Nuclear Information System (INIS)

    Ng, F.L.; Wei, J.; Lai, F.K.; Goh, K.L.

    2006-01-01

    In this study, a low-cost technique, energy dispersive spectroscopy (EDS), was used to explore the application of X-ray microanalysis in depth determination of metallic films. Al, Ni and Au films with varied thicknesses from 50 to 400 nm were deposited on silicon (Si) substrates by magnetron sputtering. Electron beam energies ranging from 4 to 30 keV were applied while other parameters were kept constant to determine the electron beam energy required to penetrate the films. The effect of the atomic number of the metallic films on the penetration capability of the electron beam was investigated. Based on the experimental results, mathematical models for Al, Ni and Au films were established and the interaction volume was simulated using a Monte Carlo program. The simulations are in good agreement with the experimental results. Al/Ni/Au multilayers were also studied

  20. Reduction to spark coordinates of data generated by automatic measurement of spark chamber film

    International Nuclear Information System (INIS)

    Maybury, R.; Hart, J.C.

    1976-09-01

    The initial stage in the data reduction for film from two spark chamber experiments is described. The film was automatically measured at the Rutherford Laboratory. The data from these measurements were reduced to a series of spark coordinates for each gap of the spark chambers. Quality control checks are discussed. (author)

  1. The Spotting Distribution of Wildfires

    Directory of Open Access Journals (Sweden)

    Jonathan Martin

    2016-06-01

    Full Text Available In wildfire science, spotting refers to non-local creation of new fires, due to downwind ignition of brands launched from a primary fire. Spotting is often mentioned as being one of the most difficult problems for wildfire management, because of its unpredictable nature. Since spotting is a stochastic process, it makes sense to talk about a probability distribution for spotting, which we call the spotting distribution. Given a location ahead of the fire front, we would like to know how likely is it to observe a spot fire at that location in the next few minutes. The aim of this paper is to introduce a detailed procedure to find the spotting distribution. Most prior modelling has focused on the maximum spotting distance, or on physical subprocesses. We will use mathematical modelling, which is based on detailed physical processes, to derive a spotting distribution. We discuss the use and measurement of this spotting distribution in fire spread, fire management and fire breaching. The appendix of this paper contains a comprehensive review of the relevant underlying physical sub-processes of fire plumes, launching fire brands, wind transport, falling and terminal velocity, combustion during transport, and ignition upon landing.

  2. Optical 3D shape measurement for nano-scale thin film buckling

    Science.gov (United States)

    Wang, S. B.; Xiao, Y.; Jia, H. K.; Li, L. A.

    2008-11-01

    This research focused on observing and measuring the 3D shape for nano-scale thin film buckling of 150nm Ti-film material deposited on organic glass substrates. With the aid of an optical microscope (2000×), the particular approaches were designed using optical wedge stepped in horizontal displacement approach and micro mechanical vertical displacement approach. The 3D shape measurement of thin film buckling on nano-scale level was carried out based on focusing-evaluation-function theory, gaussian interpolation and other theories related to digital image. After comparing the different measuring results and data from different focusing evaluation functions, an error analysis was established on the nature of such functions. In this experiment, we only focused on the measurement on the 3D shape for 150nm-thick thin film buckling. This research makes promotion in measurement on 3D shape of thin film buckling on nano-scale level.

  3. Elastohydrodynamic film thickness formula based on X-ray measurements with a synthetic paraffinic oil

    Science.gov (United States)

    Loewenthal, S. H.; Parker, R. J.; Zaretsky, E. V.

    1973-01-01

    An empirical elastohydrodynamic film thickness formula for heavily loaded contacts based upon X-ray film thickness measurements made with a synthetic paraffinic oil is presented. The deduced relation was found to adequately reflect the high load dependence exhibited by the measured minimum film thickness data at high Hertizian contact stresses, that is, above 1.04 x 10 to the ninth N/sq m (150,000 psi). Comparisons were made with the numerical results from a theoretical isothermal film thickness formula. The effects of changes in contact geometry, material, and lubricant properties on the form of the empirical model are also discussed.

  4. 3{omega} measurements of half-Heusler thin films using a passive circuit

    Energy Technology Data Exchange (ETDEWEB)

    Mix, Christian; Jaeger, Tino; Jakob, Gerhard [Institut fuer Physik, Universitaet Mainz, Staudinger Weg 7, 55128 Mainz (Germany)

    2011-07-01

    One possibility to increase the thermoelectric Figure-of-Merit of thin films is to decrease the thermal conductivity, by replacing the thin film with a superlattice of the same thickness. This is one of the major challenges in ongoing research. For this purpose a 3{omega}-measurement system is built up to obtain the thermal conductivity of thin films. To nullify influences of active elements, a setup including a wheatstone bridge is used. Different aspects of the measurement system like the influence of thermal penetration depth and the energy losses by atmosphere are discussed. Additionally, first results on Half-Heusler thin films and superlattices are presented.

  5. 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.

  6. 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.

  7. Mongolian spots

    Directory of Open Access Journals (Sweden)

    Divya Gupta

    2013-01-01

    Full Text Available Mongolian spots (MS are birthmarks that are present at birth and their most common location is sacrococcygeal or lumbar area. Lesions may be single or multiple and usually involve < 5% total body surface area. They are macular and round, oval or irregular in shape. The color varies from blue to greenish, gray, black or a combination of any of the above. The size varies from few to more than 20 centimetres. Pigmentation is most intense at the age of one year and gradually fades thereafter. It is rarely seen after the age of 6 years. Aberrant MS over occiput, temple, mandibular area, shoulders and limbs may be confused with other dermal melanocytoses and bruises secondary to child abuse, thus necessitating documentation at birth. Although regarded as benign, recent data suggest that MS may be associated with inborn errors of metabolism and neurocristopathies. Mongolian spots usually resolve by early childhood and hence no treatment is generally needed if they are located in the sacral area. However, sometimes it may be required for extrasacral lesions for cosmesis.

  8. Measurements of reciprocity law failure in green-sensitive X-ray films.

    Science.gov (United States)

    Arnold, B A; Eisenberg, H; Bjärngard, B E

    1978-02-01

    Reciprocity law failure was measured for four brands of medical x-ray films exposed with intensifying screens. Three of the films are green light-sensitized for use in combination with green light-emitting rare-earth screens. These films showed larger reciprocity failure effects than one conventional blue-sensitive film, Dupont Cronex-2. Development conditions had a small effect on reciprocity failure. As part of the investigation, a detector was constructed with a response that accurately monitors the light emission from the double screen-cassette combination over a wide range of x-ray photon energies.

  9. Soft X-ray fluorescence measurements of irradiated polymer films

    Science.gov (United States)

    Winarski, R. P.; Ederer, D. L.; Pivin, J.-C.; Kurmaev, E. Z.; Shamin, S. N.; Moewes, A.; Chang, G. S.; Whang, C. N.; Endo, K.; Ida, T.

    1998-11-01

    Fluorescent soft X-ray carbon Kα emission spectra (XES) have been used to characterize the bonding of carbon atoms in polyimide (PI) and polycarbosilane (PCS) films. The PI films have been irradiated with 40 keV nitrogen or argon ions, at fluences ranging from 1 × 10 14 to 1 × 10 16 cm -2. The PCS films have been irradiated with 5 × 10 15 carbon ions cm -2 of 500 keV and/or annealed at 1000°C. We find that the fine structure of the carbon XES of the PI films changes with implanted ion fluence above 1 × 10 14 cm -2 which we believe is due to the degradation of the PI into amorphous C:N:O. The width of the forbidden band as determined from the high-energy cut-off of the C Kα X-ray excitation decreases with the ion fluence. The bonding configuration of free carbon precipitates embedded in amorphous SiC which are formed in PCS after irradiation with C ions or combined treatments (irradiation and subsequent annealing) is close to either to that in diamond-like films or in silicidated graphite, respectively.

  10. Application of alternating current impedance measurements to characterize zirconium alloy oxidation films

    Science.gov (United States)

    Rosecrans, P. M.

    1982-06-01

    In an effort to understand observed differences in high temperature steam corrosion resistance, high frequency (500 Hz) a-c impedance measurements were used to monitor the permeability of oxidation films formed on Zircaloy 2 and Zircaloy 4 samples exposed to high temperature steam. Differences in oxidation resistance are related to differences in oxidation film permeability and ultimately to film characteristics. When these results are added to the existing data base established for zirconium alloy oxidation films using the high frequency impedance technique, improved understanding of the role of bulk corrodent access to the metal-oxide interface during oxidation becomes possible. In addition, differences in film character resulting from differences in oxidation environment become apparent upon review of the existing data base. Such differences may have practical application in selecting material preconditioning procedures and suggest explanations for some oxide film memory effects reported in the literature.

  11. Solid surface tension measured by a liquid drop under a solid film.

    Science.gov (United States)

    Nadermann, Nichole; Hui, Chung-Yuen; Jagota, Anand

    2013-06-25

    We show that a drop of liquid a few hundred microns in diameter placed under a solid, elastic, thin film (∼10 μm thick) causes it to bulge by tens of microns. The deformed shape is governed by equilibrium of tensions exerted by the various interfaces and the solid film, a form of Neumann's triangle. Unlike Young's equation, which specifies the contact angles at the junction of two fluids and a (rigid) solid, and is fundamentally underdetermined, both tensions in the solid film can be determined here if the liquid-vapor surface tension is known independently. Tensions in the solid film have a contribution from elastic stretch and a constant residual component. The residual component, extracted by extrapolation to films of vanishing thickness and supported by analysis of the elastic deformation, is interpreted as the solid-fluid surface tension, demonstrating that compliant thin-film structures can be used to measure solid surface tensions.

  12. Optical approach to thermopower and conductivity measurements in thin-film semiconductors

    International Nuclear Information System (INIS)

    Dersch, H.; Amer, N.M.

    1984-01-01

    An optical beam deflection technique is applied to measure the Joule and Peltier heat generated by electric currents through thin-film semiconductors. The method yields a spatially resolved conductivity profile and allows the determination of Peltier coefficients. Results obtained on doped hydrogenated amorphous silicon films are presented

  13. Antimicrobial compounds in polyethylene films - characterization and content measurement techniques

    International Nuclear Information System (INIS)

    Pires, Marcia; Santos, Ramon V.; Perao, Leandro; Ellwangler, Manoela W.; Nonemacher, Regina F.; Moraes, Lilian T. de; Gorski, Sandro; Staub, Simone; Petzhold, Cesar L.

    2009-01-01

    Developments have been done in the packaging market to attend the continuous changes in consumer demands and also to keep safety and shelf life of products during transportation and storage. Active packaging is the most innovative concepts in the market. It has been defined as a packaging that changes its conditions to extend shelf life. The objective of this work is the production and characterization of active polyethylene films with antimicrobial compounds. The initial results show that analytical techniques as RX fluorescence and FTIR can be used to characterize and quantify these compounds in polyethylene films. (author)

  14. Measurement of the radial temperature distribution of the heated spot produced by a focused laser beam using an optical pyrometer.

    Science.gov (United States)

    Hendricks, L J; Zobrist, S P

    1981-05-15

    A method is described for the evaluation of the Gaussian curve parameters needed for the description of the temperature distribution of the heated spot produced on a target substrate by a well-focused laser beam, using an optical pyrometer to read the weighted average temperatures from two distinct distances. The parameter so found gave a calculated distribution curve in excellent agreement with experimental determinations of that distribution.

  15. Novel geometry for simultaneous resistive, Hall and optical measurement of MgHx thin films

    Science.gov (United States)

    Koon, D. W.; Griffin, C. C. W.; Ares, J. R.; Leardini, F.; Sanchez, C.

    2009-03-01

    We describe a novel specimen geometry we have used to simultaneously probe optical transmission, sheet resistance and sheet Hall resistance in 100nm Mg films during hydrogen absorption. A Mg-film cloverleaf overlaps four rectangular Pd pads at the corners of a glass slide, a variation on a two-pad geometry used by Ingason and Olafsson for resistive studies of Pd-capped MgHx films [J. Alloys and Compounds 404- 406 (2005), 469-72.]. Hydrogen diffuses laterally through the Pd pads before entering the magnesium layer from below. The sample holder also includes an LED-photodiode pair for measuring [monochromatic] optical transmission. We show that the simultaneous measurement of these three quantities during the metal-to-insulator transition in a hydriding MgHx film allows for a more complete understanding of the hydriding process in these films.

  16. Dynamic measurement of the corneal tear film with a Twyman-Green interferometer.

    Science.gov (United States)

    Micali, Jason D; Greivenkamp, John E; Primeau, Brian C

    2015-05-01

    An interferometer for measuring dynamic properties of the in vivo tear film on the human cornea has been developed. The system is a near-infrared instantaneous phase-shifting Twyman-Green interferometer. The laser source is a 785 nm solid-state laser, and the system has been carefully designed and calibrated to ensure that the system operates at eye-safe levels. Measurements are made over a 6 mm diameter on the cornea.Successive frames of interferometric height measurements are combined to produce movies showing both the quantitative and qualitative changes in the topography of the tear film surface and structure. To date, measurement periods of up to 120 s at 28.6 frames per second have been obtained. Several human subjects have been examined using this system, demonstrating a surface height resolution of 25 nm and spatial resolution of 6 μm. Examples of features that have been observed in these preliminary studies of the tear film include postblink disruption, evolution, and stabilization of the tear film; tear film artifacts generated by blinking; tear film evaporation and breakup; and the propagation of foreign objects in the tear film. This paper discusses the interferometer design and presents results from in vivo measurements.

  17. Sensitivity of surface resistance measurement of HTS thin films by ...

    Indian Academy of Sciences (India)

    For the characteriza- tion of films, the resonators were mounted in an evacuated cryo-cooler and cooled down to lowest temperature. Microwave power was fed to the resonator through low loss cables and transmitted resonance signal was analyzed using scalar network analyzer (HP-8757D). The temperature is then slowly ...

  18. Sensitivity of film measured off-axis ratios to film calibration curve using radiochromic film; Sensibilidade das razoes fora do eixo central medidas para a curva de calibracao de filmes usando filme radiocromico

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Hernandez, Diana [Universidad Nacional Autnoma de Mexico (UNAM), Mexico City (Mexico). Inst. de Fisica; Larraga-Gutierrez, Jose M. [Instituto Nacional de Neurologia y Neurocirugia, Mexico City (Mexico). Unidad de Radioneurocirugia. Lab. de Fisica Medica

    2011-07-01

    Off-axis ratios of conical beams generated with a stereotactic radiosurgery-dedicated Linac were measured with EBT2 film and stereotactic diode. The sensitivity of both full width at half maximum (FWHM) and penumbras (80-20% and 90-10%, respectively), with respect to the characteristics of the film calibration curve fit, was investigated. In all cases, penumbras resulted to be more sensitive than FWHM. However, these differences were, in general, smaller than the ones found between EBT2 reference values and the stereotactic diode measurements. The larger variation in OAR parameters was found to depend on whether the fit intersected or not the origin. A 1D gamma-index analysis showed this difference can be important in all measured conical beams. (author)

  19. Measurement of full-field deformation induced by a dc electrical field in organic insulator films

    Directory of Open Access Journals (Sweden)

    Boudou L.

    2010-06-01

    Full Text Available Digital image correlation method (DIC using the correlation coefficient curve-fitting for full-field surface deformation measurements of organic insulator films is investigated in this work. First the validation of the technique was undertaken. The computer-generated speckle images and the measurement of coefficient of thermal expansion (CTE of aluminium are used to evaluate the measurement accuracy of the technique. In a second part the technique is applied to measure the mechanical deformation induced by electrical field application to organic insulators. For that Poly(ethylene naphthalene 2,6-dicarboxylate (PEN thin films were subjected to DC voltage stress and DIC provides the full-field induced deformations of the test films. The obtained results show that the DIC is a practical and robust tool for better comprehension of mechanical behaviour of the organic insulator films under electrical stress.

  20. Mobile Launch Platform Vehicle Assembly Building Area (SWMU 056) Hot Spot 3 Bioremediation Interim Measures Work Plan, Kennedy Space Center, Florida

    Science.gov (United States)

    Whitney L. Morrison; Daprato, Rebecca C.

    2016-01-01

    This Interim Measures Work Plan (IMWP) presents an approach and design for the remediation of chlorinated volatile organic compound (CVOC) groundwater impacts using bioremediation (biostimulation and bioaugmentation) in Hot Spot 3, which is defined by the area where CVOC (trichloroethene [TCE], cis-1,2-dichloroethene [cDCE], and vinyl chloride [VC]) concentrations are greater than 10 times their respective Florida Department of Environmental Protection (FDEP) Natural Attenuation Default Concentration (NADC) [10xNADC] near the western Mobile Launch Platform (MLP) structure. The IM treatment area is the Hot Spot 3 area, which is approximately 0.07 acres and extends from approximately 6 to 22 and 41 to 55 feet below land surface (ft BLS). Within Hot Spot 3, a source zone (SZ; area with TCE concentrations greater than 1% solubility [11,000 micrograms per liter (micrograms/L)]) was delineated and is approximately 0.02 acres and extends from approximately 6 to 16 and 41 to 50 ft BLS.

  1. Thermal expansion coefficient measurement from electron diffraction of amorphous films in a TEM.

    Science.gov (United States)

    Hayashida, Misa; Cui, Kai; Malac, Marek; Egerton, Ray

    2018-05-01

    We measured the linear thermal expansion coefficients of amorphous 5-30 nm thick SiN and 17 nm thick Formvar/Carbon (F/C) films using electron diffraction in a transmission electron microscope. Positive thermal expansion coefficient (TEC) was observed in SiN but negative coefficients in the F/C films. In case of amorphous carbon (aC) films, we could not measure TEC because the diffraction radii required several hours to stabilize at a fixed temperature. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  2. Film

    OpenAIRE

    Jones, Sarah

    2002-01-01

    This book looks at the movie industry and at the labour intensive but fascinating process of making a feature film. It examines each stage in the production of a film, from initial idea through to the final cut and screening, and highlights the main activities that take place along the way. The book not only looks at the work of prominent people in the film world, such as directors and actors, but also describes the equally important but less high profile contributions of the gaffer, best boy...

  3. Role of geometric parameters in electrical measurements of insulating thin films deposited on a conductive substrate

    Science.gov (United States)

    Kumar, S.; Gerhardt, R. A.

    2012-03-01

    The effects of film thickness, electrode size and substrate thickness on the impedance parameters of alternating frequency dielectric measurements of insulating thin films deposited on conductive substrates were studied through parametric finite-element simulations. The quasi-static forms of Maxwell's electromagnetic equations in a time harmonic mode were solved using COMSOL Multiphysics® for several types of 2D models (linear and axisymmetric). The full 2D model deals with a configuration in which the impedance is measured between two surface electrodes on top of a film deposited on a conductive substrate. For the simplified 2D models, the conductive substrate is ignored and the two electrodes are placed on the top and bottom of the film. By comparing the full model and the simplified models, approximations and generalizations are deduced. For highly insulating films, such as the case of insulating SiO2 films on a conducting Si substrate, even the simplified models predict accurate capacitance values at all frequencies. However, the edge effects on the capacitance are found to be significant when the film thickness increases and/or the top electrode contact size decreases. The thickness of the substrate affects predominantly the resistive components of the dielectric response while having no significant effect on the capacitive components. Changing the electrode contact size or the film thickness determines the specific values of the measured resistance or capacitance while the material time constant remains the same, and thus this affects the frequency dependence that is able to be detected. This work highlights the importance of keeping in mind the film thickness and electrode contact size for the correct interpretation of the measured dielectric properties of micro/nanoscale structures that are often investigated using nanoscale capacitance measurements.

  4. Film

    OpenAIRE

    Bould, M.

    2014-01-01

    A critical overview of critical-theoretical understandings of sf film, especially those promulgated by critics devoted to sf as a prose fiction form. It also considers adaptation, spectacle and special effects.

  5. Direct Measurement of Crazing Mechanics in Polystyrene Thin Films: Molecular Weight Effects

    Science.gov (United States)

    Shimomura, Shinichiro; Bay, Reed; Ilton, Mark; Crosby, Alfred

    Mechanical properties of polymer thin films are critical to various applications such as protective coatings, electronic devices, and separation membranes. Although methods for measuring the structure and some physical properties, such as Tg, of polymer thin films have been well established, measuring mechanical properties of thin films has not been fully developed and has been largely limited to extremely small strains and complex stress distributions. To overcome these limitations, we have recently introduced a direct measurement technique for quantifying the complete uniaxial stress-strain relationship for polymer thin films. Here, we use `dog-bone' shaped thin films of polystyrene (PS) to quantify the change in mechanical response as a function of molecular weight. We observe a nonlinear stress-strain relationship, resembling ideal plastic-like behavior, associated with the onset of crazing. We will discuss how the onset stress and critical strain to failure changes as a function of molecular weight. These changes, and the alignment of craze fibrils, are discussed in the context of how entanglement density is altered for confined thin films. These results provide new insight into fundamental molecular physics for polymer thin films.

  6. Study of the Radiochromic Film for High Dose Measurement in Radiation Processing

    Directory of Open Access Journals (Sweden)

    CHEN Yi-zhen

    2016-02-01

    Full Text Available To establish the radiochromic film dosimeter for high dose level measurement during radiation processing, By corresponding formula and its preparation process research, batches of radiochromic film dosimeters were prepared using nylon as substrate and pararosaniline cyanide as dye. In Co-60 gamma reference radiation field, dosimetry response performance of radiochromic film was studied and results showed that the repeatability was good to 1.0%. The response curves demonstrated good linearity in the dose range of 5-210 kGy, and the signal of radiochromic film dosimeters after irradiation under the condition of low temperature storage within 2 weeks was stable. In addition, the radiochromic film dosimeters were not found to have noticeable dose rate dependence in the range of this experiment. In the linear dose range, radiochromic film dosimeter measures the absorbed dose, with extended uncertainty 4.2% (k=2 for Co-60 gamma rays. The film was suitable as dosimeters for the parameters measurement of the electron beam on the accelerator.

  7. The characterization of TiN thin films using optical reflectivity measurements

    International Nuclear Information System (INIS)

    Glew, M R L; Vollmer, A; Schroeder, S L M; Barber, Z H

    2002-01-01

    Thin films of TiN have been deposited by reactive magnetron sputter deposition in varying partial pressures of nitrogen. Reflectivity measurements have been carried out between 1.5 and 3.5 eV and a correlation made between the film properties and optical data. Resistivity measurements carried out at room temperature are shown to exhibit the same trends as those obtained from reflectivity experiments. X-ray absorption fine structure measurements, in both electron-yield and fluorescence-yield modes, have shown the films to be identical and stoichiometric to within ±5 at.%. The use of reflectivity spectra to form the basis of a characterization tool for physical vapour deposited thin films is discussed

  8. Precise measurement of the transverse piezoelectric coefficient for thin films on anisotropic substrate

    International Nuclear Information System (INIS)

    Chun, Doo-Man; Sato, Masashi; Kanno, Isaku

    2013-01-01

    In this study, we propose a reliable measurement method for the effective transverse piezoelectric coefficient for thin films especially on anisotropic substrate. This coefficient for piezoelectric Pb(Zr, Ti)O 3 (PZT) thin films was calculated by measuring the electric field-induced tip displacement of unimorph cantilevers composed of PZT thin films and Si substrates. We evaluated the reliability of the proposed measurement method by comparing it with numerical analysis and confirmed that the relative error of the piezoelectric coefficient (e 31,f ) was less than 1%. We prepared 16 different unimorph cantilevers composed of identical PZT films on different Si beam geometries that had various substrate thicknesses and cantilever widths. Although the effective transverse piezoelectric coefficient e 31,f of PZT thin films ranged from −6.5 to −14 C/m 2 as a function of the applied voltage, the difference among the 16 samples with an applied voltage of 25 V was within 10%. These results demonstrate that the proposed measurement method has sufficient reliability and can be used to evaluate the effective transverse piezoelectric coefficient e 31,f of thin films.

  9. Radiochromic film measurement of spatial uniformity for a laser generated x-ray environment

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, J. H.; Newlander, C. D.; Horton, R.; Fournier, K. B.; Emig, J.; Patterson, R.; Davis, J. F.; Seiler, S.; Jenkins, P. P.

    2012-10-01

    n existing x-ray source application (XRSA) test cassette was modified to hold multiple x-ray filter materials followed by two radiochromic film types (FWT-60 and HD-810 Gafchromic® film) to qualitatively characterize the spectral-spatial uniformity over the XRSA sample field of view. Multiple sets of film were examined and nominal set was determined. These initial, qualitative measurements suggest a low-energy regime (E < 3 keV) spatial anisotropy and spatial isotropy at higher energies (E > 3 keV).

  10. Measurement of flexoelectric response in polyvinylidene fluoride films for piezoelectric vibration energy harvesters

    International Nuclear Information System (INIS)

    Choi, Seung-Bok; Kim, Gi-Woo

    2017-01-01

    This study presents an investigation on the measurement of flexoelectric response in β -phase polyvinylidene fluoride (PVDF) films attached on cantilever beam-based flexible piezoelectric vibration energy harvesters (PVEHs). The flexoelectric response associated with negative strain gradients was simulated through harmonic response analysis by using the finite element method (FEM). The polarization frequency response functions (FRFs) modified by direct flexoelectric effect of PVDF films was experimentally validated by multi-mode FRFs. From quantitative comparisons between experimental observations and simulated estimation of FRFs, it is demonstrated that the direct flexoelectric response can be observed in PVDF films attached on PVEHs. (paper)

  11. Safe and consistent method of spot-welding platinum thermocouple wires and foils for high temperature measurements

    Science.gov (United States)

    Orr, G.; Roth, M.

    2012-08-01

    A low-voltage (mV) electronically triggered spot welding system for fabricating fine thermocouples and thin sheets used in high-temperature characterization of materials' properties is suggested. The system is based on the capacitance discharge method with a timed trigger for obtaining reliable and consistent welds. In contrast to existing techniques based on employing high voltage DC supplies for charging the capacitor or supplies with positive and negative rails, this method uses a simple, standard dual power supply available at most of the physical laboratories or can be acquired at a low cost. In addition, an efficient and simple method of fabricating non-sticking electrodes that do not contaminate the weld area is suggested and implemented.

  12. A new technique of measuring trace absorption of optical thin films

    International Nuclear Information System (INIS)

    Apparao, K.V.S.R.; Sahoo, N.K.

    1993-01-01

    An instrument to measure trace absorption of optical thin films is indigenously developed using a novel technique. The instrument based on calorimetric principle measures the temperature rise and absorption of a sample simultaneously by two independent techniques. Such a dual technique feature enables one to measure the sample absorption with the first technique and simultaneously check the result with the second technique. The instrument can be used to measure trace absorption of dielectric optical thin films in UV, visible and near-IR spectral regions. Using the new instrument the absorption constant β and extinction coefficient k of Sb 2 O 3 and ZrO 2 films at 308 and 337 nm are measured successfully and reported for the first time. (author). 16 refs., 6 figs., 3 tabs

  13. Characterization of the flooding in vertical tubes by means of the film thickness measurement

    International Nuclear Information System (INIS)

    Malandrone, M.; Mioliggi, L.; Panella, B.; Scorta, G.

    1992-01-01

    The air-water countercurrent flow up to the flooding transition in a vertical tube has been experimentally investigated by liquid film thickness measurement performed by means of an electrical two-wires conductance probe. The liquid film mean thickness, the probability density function, the spectral power density and the power of the signal have been derived for a wide range of air and water flow rate, and related to the flow pattern with particular attention to the flooding phenomena. (6 figures) (Author)

  14. The use of a CCD imaging system for X-ray film intensity measurement

    International Nuclear Information System (INIS)

    Grigg, M.W.; Barnea, Z.

    1994-01-01

    The use of a simple CCD-based imaging system for digitizing and x-ray film image is demonstrated. A method of extending the region of linear response of the film based upon an analytic representation of the observed response to a series of increasing exposures is described. The validity of the procedure is illustrated through an example of the absolute intensity measurement of a reflection of cadmium sulphide. 3 refs., 7 figs

  15. Verification of relative output factor measurement using Gafchromic films for small-field radiosurgery photon beams.

    Science.gov (United States)

    Abdullah, R.; Sapeei, M. S.; Shukor, N. S. A.; Yusof, M. F. M.; Mohamed, M.; Idris, N. R. N.; Yusoff, A. L.; Zakaria, A.; Aziz, M. Z. A.

    2018-01-01

    Accurate dosimetry of small-field photon beams has always been difficult to achieve, due to the steep dose gradient and absence of lateral electronic equilibrium. The purpose of this study was to verify the measurement of relative output factor (ROF), which is one of the dosimetric parameter required for stereotactic radiosurgery (SRS) treatment planning. The ROFs for Radionics circular cone collimators with diameter in the range of 10.0 to 45.0 mm were measured using Gafchromic EBT2 and EBT3 films. The measurements were then compared with the ROFs obtained using a PinPoint ionisation chamber and Monte Carlo (MC) simulation. From the results, the ROFs measured by the ionisation chamber, EBT2, and EBT3 films were good agreement with the MC simulation, with deviations of less than 1.5, 2.6, and 5.0 % respectively. Based on the film dosimetry, the EBT2 film showed in a more reliable measurement for field size ranging from 15.0 to 45.0 mm, compared with EBT3. As a conclusion, based on the special characteristic of the small-field photon beams, ROF measurement using PinPoint ionisation chamber are being favoured, due to its accuracy. However, the EBT2 film can be used as an alternative, when high spatial resolution is required.

  16. Real Time Ultrasonic Aluminum SPOT Weld Monitoring System

    Science.gov (United States)

    Regalado, W. Pérez; Chertov, A. M.; Maev, R. Gr.

    2010-02-01

    Aluminum alloys pose several properties that make them one of the most popular engineering materials: they have excellent corrosion resistance, and high weight-to-strength ratio. Resistance spot welding of aluminum alloys is widely used today but oxide film and aluminum thermal and electrical properties make spot welding a difficult task. Electrode degradation due to pitting, alloying and mushrooming decreases the weld quality and adjustment of parameters like current and force is required. To realize these adjustments and ensure weld quality, a tool to measure weld quality in real time is required. In this paper, a real time ultrasonic non-destructive evaluation system for aluminum spot welds is presented. The system is able to monitor nugget growth while the spot weld is being made. This is achieved by interpreting the echoes of an ultrasound transducer located in one of the welding electrodes. The transducer receives and transmits an ultrasound signal at different times during the welding cycle. Valuable information of the weld quality is embedded in this signal. The system is able to determine the weld nugget diameter by measuring the delays of the ultrasound signals received during the complete welding cycle. The article presents the system performance on aluminum alloy AA6022.

  17. Stress measurement and stress relaxation during magnetron sputter deposition of cubic boron nitride thin films

    International Nuclear Information System (INIS)

    Abendroth, B.; Gago, R.; Kolitsch, A.; Moeller, W.

    2004-01-01

    Dynamic in situ analysis of stress and film thickness provide fast and more physical information on growth and stress evolution in cBN layers than integrating (ex situ) methods. Especially, features of the layered structure of boron nitride films, like the evolution of instantaneous stress and growth rates during deposition can be resolved by in situ methods. This work is concerned with dynamic in-situ stress measurement by means of cantilever bending during magnetron sputter deposition of cBN thin films. Laser deflection in combination with in situ ellipsometry is used to determine the instantaneous stress of the films. The results show in agreement with results that were obtained previously from ion beam assisted deposition (IBAD), that the hBN and cBN layers exhibit different levels of stress under constant deposition conditions. The stress increases from less than -4 GPa to very high values (-10 GPa) after the coalescence of the cBN nuclei. Therefore, it is possible to establish the point of cBN nucleation instantly. A simultaneous medium energy ion bombardment is used for stress relaxation during film deposition. A modified substrate bias voltage, combining negative high and low voltage pulses, is used to enable an ion bombardment of the growing film with energies up to 8 keV. In this way, cBN films with a stress as low as -1.7 GPa could be produced without destroying the sp 3 -bonds significantly

  18. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  19. Critical issues in measuring the mechanical properties of hard films on soft substrates by nanoindentation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Hay, J.C. [Oak Ridge National Lab., TN (United States); Pharr, G.M. [Rice Univ., Houston, TX (United States). Dept. of Materials Science

    1997-12-31

    This study explores the difficulties encountered when using conventional nanoindentation techniques to measure the Young`s modulus and hardness of hard films on soft substrates. In general, the indentation measurement of film/substrate systems is affected by four material properties: the Young`s modulus and hardness of the film, and the Young`s modulus and hardness of the substrate. For the particular case of a hard film on a soft substrate, there is a tendency for the material around the hardness impression to sink-in which results from the large difference in yielding of the two materials. In this study, a model system consisting of NiP on annealed Cu was used to explore the behavior. This system is interesting because the film and substrate have similar Young`s moduli, minimizing the elastic behavior as a variable. In contrast, the hardness of NiP is approximately 7--8 GPa, and that of the annealed copper is less than 1 GPa, providing a factor of 10 difference in the plastic flow characteristics. Experimental results indicate that standard analytical methods for determining the contact depth, hardness and Young`s modulus do not work well for the case of a hard film on a soft substrate. At shallow contact depths, the measured indentation modulus is close to that of the film, but at larger depths sink-in phenomena result in an overestimation of the contact area, and an indentation modulus which is less than the Young`s modulus of both the film and substrate. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) provide critical details of the physical processes involved, and illustrate how the standard data analyses overestimate the true contact area.

  20. Cantilever measurements of surface stress, surface reconstruction, film stress and magnetoelastic stress of monolayersc

    Directory of Open Access Journals (Sweden)

    Jürgen Kirschner

    2008-07-01

    Full Text Available We review the application of cantilever-based stress measurements in surface science and magnetism. The application of thin (thickness appr. 0.1 mm single crystalline substrates as cantilevers has been used successfully to measure adsorbate-induced surface stress changes, lattice misfit induced film stress, and magneto-elastic stress of ferromagnetic monolayers. Surface stress changes as small as 0.01 N/m can be readily measured, and this translates into a sensitivity for adsorbate-coverage well below 0.01 of one layer. Stress as large as several GPa, beyond the elasticity limits of high strength materials, is measured, and it is ascribed to the lattice misfit between film and substrate. Our results point at the intimate relation between surface stress and surface reconstruction, stress-induced structural changes in epitaxially strained films, and strain-induced modifications of the magneto-elastic coupling in ferromagnetic monolayers.

  1. Cantilever measurements of surface stress, surface reconstruction, film stress and magnetoelastic stress of monolayers.

    Science.gov (United States)

    Sander, Dirk; Tian, Zhen; Kirschner, Jürgen

    2008-07-29

    We review the application of cantilever-based stress measurements in surface science and magnetism. The application of thin (thickness appr. 0.1 mm) single crystalline substrates as cantilevers has been used successfully to measure adsorbate-induced surface stress changes, lattice misfit induced film stress, and magneto-elastic stress of ferromagnetic monolayers. Surface stress changes as small as 0.01 N/m can be readily measured, and this translates into a sensitivity for adsorbate-coverage well below 0.01 of one layer. Stress as large as several GPa, beyond the elasticity limits of high strength materials, is measured, and it is ascribed to the lattice misfit between film and substrate. Our results point at the intimate relation between surface stress and surface reconstruction, stress-induced structural changes in epitaxially strained films, and strain-induced modifications of the magneto-elastic coupling in ferromagnetic monolayers.

  2. Thermal pulse measurements of space charge distributions under an applied electric field in thin films

    International Nuclear Information System (INIS)

    Zheng, Feihu; An, Zhenlian; Zhang, Yewen; Liu, Chuandong; Lin, Chen; Lei, Qingquan

    2013-01-01

    The thermal pulse method is a powerful method to measure space charge and polarization distributions in thin dielectric films, but a complicated calibration procedure is necessary to obtain the real distribution. In addition, charge dynamic behaviour under an applied electric field cannot be observed by the classical thermal pulse method. In this work, an improved thermal pulse measuring system with a supplemental circuit for applying high voltage is proposed to realize the mapping of charge distribution in thin dielectric films under an applied field. The influence of the modified measuring system on the amplitude and phase of the thermal pulse response current are evaluated. Based on the new measuring system, an easy calibration approach is presented with some practical examples. The newly developed system can observe space charge evolution under an applied field, which would be very helpful in understanding space charge behaviour in thin films. (paper)

  3. Experimental study on two-dimensional film flow with local measurement methods

    International Nuclear Information System (INIS)

    Yang, Jin-Hwa; Cho, Hyoung-Kyu; Kim, Seok; Euh, Dong-Jin; Park, Goon-Cherl

    2015-01-01

    Highlights: • An experimental study on the two-dimensional film flow with lateral air injection was performed. • The ultrasonic thickness gauge was used to measure the local liquid film thickness. • The depth-averaged PIV (Particle Image Velocimetry) method was applied to measure the local liquid film velocity. • The uncertainty of the depth-averaged PIV was quantified with a validation experiment. • Characteristics of two-dimensional film flow were classified following the four different flow patterns. - Abstract: In an accident condition of a nuclear reactor, multidimensional two-phase flows may occur in the reactor vessel downcomer and reactor core. Therefore, those have been regarded as important issues for an advanced thermal-hydraulic safety analysis. In particular, the multi-dimensional two-phase flow in the upper downcomer during the reflood phase of large break loss of coolant accident appears with an interaction between a downward liquid and a transverse gas flow, which determines the bypass flow rate of the emergency core coolant and subsequently, the reflood coolant flow rate. At present, some thermal-hydraulic analysis codes incorporate multidimensional modules for the nuclear reactor safety analysis. However, their prediction capability for the two-phase cross flow in the upper downcomer has not been validated sufficiently against experimental data based on local measurements. For this reason, an experimental study was carried out for the two-phase cross flow to clarify the hydraulic phenomenon and provide local measurement data for the validation of the computational tools. The experiment was performed in a 1/10 scale unfolded downcomer of Advanced Power Reactor 1400 (APR1400). Pitot tubes, a depth-averaged PIV method and ultrasonic thickness gauge were applied for local measurement of the air velocity, the liquid film velocity and the liquid film thickness, respectively. The uncertainty of the depth-averaged PIV method for the averaged

  4. Friction and wear measurements of sputtered MoS/sub x/ films amorphized by ion bombardment

    International Nuclear Information System (INIS)

    Mikkelsen, N.J.; Chevallier, J.; Soerensen, G.; Straede, C.A.

    1988-01-01

    The present study presents an experimental evidence for amorphization of rf sputtered MoS/sub x/ films by ion bombardment. Even at low doses (3 x 10 15 ions/cm 2 ) of 400 keV argon ions a complete amorphization was confirmed by x-ray diffraction analysis and transmission electron microscopy. As a result of the ion bombardment the film density increased 100% to almost the bulk value for MoS 2 . The friction coefficient for ion beam amorphized MoS/sub x/ was measured to be 0.04 in agreement with the values reported for crystalline films but disagreeing considerably with the friction coefficient of 0.4 previously reported for amorphous films

  5. A nanoporous thin-film miniature interdigitated capacitive impedance sensor for measuring humidity

    Directory of Open Access Journals (Sweden)

    T. Islam

    2014-07-01

    Full Text Available This paper presents a development of a low-cost miniature humidity sensor with an interdigitated aluminium electrode connected in parallel on quartz substrate. Interdigitated capacitive device has been fabricated using the photolithography method. The aluminium electrode was covered with sensitive film of a nanoporous thin film of γ-Al2O3 made from novel sol–gel technique. Nanostructured thin film offers very high surface to volume ratio with distribution of micro pores for moisture detection. Pore morphologies of the film have been studied by field emission electron microscope and X-ray diffraction methods. Impedance measurement of the miniature capacitive humidity sensor toward relative humidity was investigated at room temperature by Agilent 4294A impedance analyzer (Agilent, Santa Clara, CA, USA. The device exhibits short response and recovery times and good repeatability.

  6. Adhesion and friction in polymer films on solid substrates: conformal sites analysis and corresponding surface measurements.

    Science.gov (United States)

    An, Rong; Huang, Liangliang; Mineart, Kenneth P; Dong, Yihui; Spontak, Richard J; Gubbins, Keith E

    2017-05-21

    In this work, we present a statistical mechanical analysis to elucidate the molecular-level factors responsible for the static and dynamic properties of polymer films. This analysis, which we term conformal sites theory, establishes that three dimensionless parameters play important roles in determining differences from bulk behavior for thin polymer films near to surfaces: a microscopic wetting parameter, α wx , defined as the ratio of polymer-substrate interaction to polymer-polymer interaction; a dimensionless film thickness, H*; and dimensionless temperature, T*. The parameter α wx introduced here provides a more fundamental measure of wetting than previous metrics, since it is defined in terms of intermolecular forces and the atomic structure of the substrate, and so is valid at the nanoscale for gas, liquid or solid films. To test this theoretical analysis, we also report atomic force microscopy measurements of the friction coefficient (μ), adhesion force (F A ) and glass transition temperature (T g ) for thin films of two polymers, poly(methyl methacrylate) (PMMA) and polystyrene (PS), on two planar substrates, graphite and silica. Both the friction coefficient and the glass transition temperature are found to increase as the film thickness decreases, and this increase is more pronounced for the graphite than for the silica surface. The adhesion force is also greater for the graphite surface. The larger effects encountered for the graphite surface are attributed to the fact that the microscopic wetting parameter, α wx , is larger for graphite than for silica, indicating stronger attraction of polymer chains to the graphite surface.

  7. Heat capacity measurements of atoms and molecules adsorbed on evaporated metal films

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, T.W.

    1989-05-01

    Investigations of the properties of absorbed monolayers have received great experimental and theoretical attention recently, both because of the importance of surface processes in practical applications such as catalysis, and the importance of such systems to the understanding of the fundamentals of thermodynamics in two dimensions. We have adapted the composite bolometer technology to the construction of microcalorimeters. For these calorimeters, the adsorption substrate is an evaporated film deposited on one surface of an optically polished sapphire wafer. This approach has allowed us to make the first measurements of the heat capacity of submonolayer films of /sup 4/He adsorbed on metallic films. In contrast to measurements of /sup 4/He adsorbed on all other insulating substrates, we have shown that /sup 4/He on silver films occupies a two-dimensional gas phase over a broad range of coverages and temperatures. Our apparatus has been used to study the heat capacity of Indium flakes. CO multilayers, /sup 4/He adsorbed on sapphire and on Ag films and H/sub 2/ adsorbed on Ag films. The results are compared with appropriate theories. 68 refs., 19 figs.

  8. Heat capacity measurements of atoms and molecules adsorbed on evaporated metal films

    International Nuclear Information System (INIS)

    Kenny, T.W.

    1989-05-01

    Investigations of the properties of absorbed monolayers have received great experimental and theoretical attention recently, both because of the importance of surface processes in practical applications such as catalysis, and the importance of such systems to the understanding of the fundamentals of thermodynamics in two dimensions. We have adapted the composite bolometer technology to the construction of microcalorimeters. For these calorimeters, the adsorption substrate is an evaporated film deposited on one surface of an optically polished sapphire wafer. This approach has allowed us to make the first measurements of the heat capacity of submonolayer films of 4 He adsorbed on metallic films. In contrast to measurements of 4 He adsorbed on all other insulating substrates, we have shown that 4 He on silver films occupies a two-dimensional gas phase over a broad range of coverages and temperatures. Our apparatus has been used to study the heat capacity of Indium flakes. CO multilayers, 4 He adsorbed on sapphire and on Ag films and H 2 adsorbed on Ag films. The results are compared with appropriate theories. 68 refs., 19 figs

  9. Characterization of mechanical properties of battery electrode films from acoustic resonance measurements

    Science.gov (United States)

    Dallon, Kathryn L.; Yao, Jing; Wheeler, Dean R.; Mazzeo, Brian A.

    2018-04-01

    Measurements of the mechanical properties of lithium-ion battery electrode films can be used to quantify and improve manufacturing processes and to predict the mechanical and electrochemical performance of the battery. This paper demonstrates the use of acoustic resonances to distinguish among commercial-grade battery films with different active electrode materials, thicknesses, and densities. Resonances are excited in a clamped circular area of the film using a pulsed infrared laser, and responses are measured using an electret condenser microphone. A numerical model is used to quantify the sensitivity of resonances to changes in mechanical properties. When the numerical model is compared to simple analytical models for thin plates and membranes, the battery films measured here trend more similarly to the membrane model. Resonance measurements are also used to monitor the drying process. Results from a scanning laser Doppler vibrometer verify the modes excited in the films, and a combination of experimental and simulated results is used to estimate the Young's modulus of the battery electrode coating layer.

  10. Band alignment measurements at heterojunction interfaces in layered thin film solar cells & thermoelectrics

    Science.gov (United States)

    Fang, Fang

    2011-12-01

    Public awareness of the increasing energy crisis and the related serious environmental concerns has led to a significantly growing demand for alternative clean and renewable energy resources. Thin film are widely applied in multiple renewable energy devices owing to the reduced amount of raw materials and increase flexibility of choosing from low-cost candidates, which translates directly into reduced capital cost. This is a key driving force to make renewable technology competitive in the energy market. This thesis is focused on the measurement of energy level alignments at interfaces of thin film structures for renewable energy applications. There are two primary foci: II -VI semiconductor ZnSe/ZnTe thin film solar cells and Bi2Te3/Sb2Te3 thin film structures for thermoelectric applications. In both cases, the electronic structure and energy band alignment at interfaces usually controls the carrier transport behavior and determines the quality of the device. High-resolution photoemission spectroscopy (lab-based XPS & synchrotron-based UPS) was used to investigate the chemical and electronic properties of epitaxial Bi2Te3 and Sb2Te3 thin films, in order to validate the anticipated band alignment at interfaces in Bi 2Te3/Sb2Te3 superlattices as one favoring electron-transmission. A simple, thorough two-step treatment of a chemical etching in dilute hydrochloric acid solution and a subsequent annealing at ˜150°C under ultra-high vacuum environment is established to remove the surface oxides completely. It is an essential step to ensure the measurements on electronic states are acquired on stoichimetric, oxide-free clean surface of Bi 2Te3 and Sb2Te3 films. The direct measurement of valence band offsets (VBO) at a real Sb 2Te3/Bi2Te3 interface is designed based on the Kraut model; a special stacking film structure is prepared intentionally: sufficiently thin Sb2Te3 film on top of Bi2Te 3 that photoelectrons from both of them are collected simultaneously. From a

  11. Squid measurement of the Verwey transition on epitaxial (1 0 0) magnetite thin films

    International Nuclear Information System (INIS)

    Dediu, V.; Arisi, E.; Bergenti, I.; Riminucci, A.; Solzi, M.; Pernechele, C.; Natali, M.

    2007-01-01

    We report results on epitaxial magnetite (Fe 3 O 4 ) thin films grown by electron beam ablation on (1 0 0) MgAl 2 O 4 substrates. At 120 K magnetite undergoes a structural and electronic transition, the so-called Verwey transition, at which magnetic and conducting properties of the material change. We observed the Verwey transition on epitaxial films with a thickness of 50 nm by comparing zero-field cooling (ZFC) and field cooling (FC) curves measured with a superconducting quantum interference device (SQUID) magnetometer. Observation of the Verwey transition by SQUID measurements in the films is sign of their high crystalline quality. Room temperature ferromagnetism has also been found by magneto-optical Kerr rotation (MOKE) and confirmed by SQUID measurements, with a hysteresis loop showing a coercive field of hundreds of Oe

  12. SU-F-18C-10: Clinical Implementation of Radiochromic Film Based CTDI Measurements

    International Nuclear Information System (INIS)

    Quintero, C; Seuntjens, J; Devic, S; Tomic, N; DeBlois, F

    2014-01-01

    Purpose: To evaluate accuracy and reproducibility of a radiochromic film-based protocol to measure computer tomography dose index (CTDI) as a part of annual QA on CT scanners and kV CBCT systems attached to linear accelerators. Methods: Energy dependence of Gafchromic XR-QA2(R) film model was tested over imaging beam qualities (50 – 140 kVp). Film pieces were irradiated in air to known values of air kerma in air (up to 10 cGy). Change in film reflectance was determined with an in-house written code using images produced by a flatbed document scanner. Calibration curves for each beam quality were created, and film responses for same air-kerma values were compared.Sets of film strips were placed into holes of a CTDI phantom and irradiated for several clinical scanning protocols on CT-simulators and CBCT systems. Film reflectance change was converted into dose to water and used to calculate CTDIvol values. Measured CTDIvol values were compared to tabulated CTDIvol values. Results: Average variations of ±5.2% in the mean film reflectance change were observed in the energy range of 80 to 140 keV, and 11.1% between 50 and 140 keV. The averaged measured CTDI values presented a mean variation for the same machine and protocol of 2.6%. However, measured CTDI values were in average 10% lower than tabulated CTDI values for CT-simulators, and 44% higher for CBCT systems. Conclusion: We found that in relatively broad range of beam qualities used in diagnostic radiology variation of film response is within ±5% resulting in ±15% systematic error in dose estimates if a single calibration curve is used. Relatively large discrepancy between measured and tabulated CTDI values for different protocols and imaging systems used within radiotherapy department strongly support the trend towards replacing CTDI value with equilibrium dose measurement in the center of cylindrical phantom as suggested by TG-111. This work was supported by the Natural Sciences and Engineering Research

  13. Study of measurement of the alcohol biomarker phosphatidylethanol (PEth) in dried blood spot (DBS) samples and application of a volumetric DBS device.

    Science.gov (United States)

    Beck, Olof; Kenan Modén, Naama; Seferaj, Sabina; Lenk, Gabriel; Helander, Anders

    2018-04-01

    Phosphatidylethanol (PEth) is a group of phospholipids formed in cell membranes following alcohol consumption. PEth measurement in whole blood samples is established as a specific alcohol biomarker with clinical and medico-legal applications. This study further evaluated the usefulness of dried blood spot (DBS) samples collected on filter paper for PEth measurement. Specimens used were surplus volumes of venous whole blood sent for routine LC-MS/MS quantification of PEth 16:0/18:1, the major PEth homolog. DBS samples were prepared by pipetting blood on Whatman 903 Protein Saver Cards and onto a volumetric DBS device (Capitainer). The imprecision (CV) of the DBS sample amount based on area and weight measurements of spot punches were 23-28%. Investigation of the relationship between blood hematocrit and PEth concentration yielded a linear, positive correlation, and at around 1.0-1.5μmol/L PEth 16:0/18:1, the PEth concentration increased by ~0.1μmol/L for every 5% increase in hematocrit. There was a close agreement between the PEth concentrations obtained with whole blood samples and the corresponding results using Whatman 903 (PEth DBS =1.026 PEth WB +0.013) and volumetric device (PEth DBS =1.045 PEth WB +0.016) DBS samples. The CV of PEth quantification in DBS samples at concentrations≥0.05μmol/L were ≤15%. The present results further confirmed the usefulness of DBS samples for PEth measurement. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Validation of amino-acids measurement in dried blood spot by FIA-MS/MS for PKU management.

    Science.gov (United States)

    Bruno, C; Dufour-Rainfray, D; Patin, F; Vourc'h, P; Guilloteau, D; Maillot, F; Labarthe, F; Tardieu, M; Andres, C R; Emond, P; Blasco, H

    2016-09-01

    Phenylketonuria (PKU) is a metabolic disorder leading to high concentrations of phenylalanine (Phe) and low concentrations of tyrosine (Tyr) in blood and brain that may be neurotoxic. This disease requires a regular monitoring of plasma Phe and Tyr as well as branched-chain amino-acids concentrations to adapt the Phe-restricted diet and other therapy that may be prescribed in PKU. We validated a Flow Injection Analysis tandem Mass Spectrometry (FIA-MS/MS) to replace the enzymatic method routinely used for neonatal screening in order to monitor in parallel to Phe, Tyr and branched-chain amino-acids not detected by the enzymatic method. We ascertained the performances of the method: linearity, detection and quantification limits, contamination index, accuracy. We cross validated the FIA-MS/MS and enzymatic methods and we evaluated our own reference ranges to monitor Phe, Tyr, Leu, Val on 59 dried blood spots of normal controls. We also evaluated Tyr, Leu and Val concentrations in PKU patients to detect some potential abnormalities, not evaluated by the enzymatic method. We developed a rapid method with excellent performances including precision and accuracy PKU patients had lower concentrations of Tyr, Leu and/or Val that could not be detected by the enzymatic method. Based on laboratory accreditation recommendations, we validated a robust, rapid and reliable FIA-MS/MS method to monitor plasma Phe concentrations but also Tyr, Leu and Val concentrations, suitable for PKU management. We evaluated our own reference ranges of concentration for a routine application of this method. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  15. Blood spot-based measures of glucose homeostasis and diabetes prevalence in a nationally representative population of young US adults.

    Science.gov (United States)

    Nguyen, Quynh C; Whitsel, Eric A; Tabor, Joyce W; Cuthbertson, Carmen C; Wener, Mark H; Potter, Alan J; Halpern, Carolyn T; Killeya-Jones, Ley A; Hussey, Jon M; Suchindran, Chirayath; Harris, Kathleen Mullan

    2014-12-01

    We investigated understudied biomarker-based diabetes among young US adults, traditionally characterized by low cardiovascular disease risk. We examined 15,701 participants aged 24 to 32 years at Wave IV of the National Longitudinal Study of Adolescent Health (Add Health, 2008). The study used innovative and relatively noninvasive methods to collect capillary whole blood via finger prick at in-home examinations in all 50 states. Assays of dried blood spots produced reliable and accurate values of HbA1c. Reliability was lower for fasting glucose and lowest for random glucose. Mean (SD) HbA1c was 5.6% (0.8%). More than a quarter (27.4%) had HbA1c-defined prediabetes. HbA1c was highest in the black, non-Hispanic race/ethnic group, inversely associated with education, and more common among the overweight/obese and physically inactive. The prevalence of diabetes defined by previous diagnosis or use of antidiabetic medication was 2.9%. Further incorporating HbA1c and glucose values, the prevalence increased to 6.8%, and among these participants, 38.9% had a previous diagnosis of diabetes (i.e., aware). Among those aware, 37.6% were treated and 64.0% were controlled (i.e., HbA1c young adults faces a historically high risk of diabetes but there is ample opportunity for early detection and intervention. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Electrode size and boundary condition independent measurement of the effective piezoelectric coefficient of thin films

    Directory of Open Access Journals (Sweden)

    M. Stewart

    2015-02-01

    Full Text Available The determination of the piezoelectric coefficient of thin films using interferometry is hindered by bending contributions. Using finite element analysis (FEA simulations, we show that the Lefki and Dormans approximations using either single or double-beam measurements cannot be used with finite top electrode sizes. We introduce a novel method for characterising piezoelectric thin films which uses a differential measurement over the discontinuity at the electrode edge as an internal reference, thereby eliminating bending contributions. This step height is shown to be electrode size and boundary condition independent. An analytical expression is derived which gives good agreement with FEA predictions of the step height.

  17. Small photon beam measurements using radiochromic film and Monte Carlo simulations in a water phantom

    International Nuclear Information System (INIS)

    Garcia-Garduno, Olivia A.; Larraga-Gutierrez, Jose M.; Rodriguez-Villafuerte, Mercedes; Martinez-Davalos, Arnulfo; Celis, Miguel A.

    2010-01-01

    This work reports the use of both GafChromic EBT film immersed in a water phantom and Monte Carlo (MC) simulations for small photon beam stereotactic radiosurgery dosimetry. Circularly collimated photon beams with diameters in the 4-20 mm range of a dedicated 6 MV linear accelerator (Novalis (registered) , BrainLAB, Germany) were used to perform off-axis ratios, tissue maximum ratios and total scatter factors measurements, and MC simulations. GafChromic EBT film data show an excellent agreement with MC results (<2.7%) for all measured quantities.

  18. Measurements of liquid film thickness, concentration, and temperature of aqueous urea solution by NIR absorption spectroscopy

    Science.gov (United States)

    Pan, R.; Jeffries, J. B.; Dreier, T.; Schulz, C.

    2016-01-01

    A multi-wavelength near-infrared (NIR) diode laser absorption sensor has been developed and demonstrated for real-time monitoring of the thickness, solute concentration, and temperature of thin films of urea-water solutions. The sensor monitors the transmittance of three near-infrared diode lasers through the thin liquid film. Film thickness, urea mass fraction, and liquid temperature were determined from measured transmittance ratios of suitable combinations of lasers. Available laser wavelengths were selected depending on the variation of the NIR absorption spectrum of the solution with temperature and solute concentration. The spectral database was measured by a Fourier transform infrared spectrometer in the range 5500-8000 cm-1 for urea solutions between 5 and 40 wt% and temperatures between 298 and 338 K. A prototype sensor was constructed, and the sensor concept was first validated with measurements using a calibration cell providing liquid layers of variable thickness (200-1500 µm), urea mass fraction (5-40 wt%) and temperature (298-318 K). Temporal variations of film thickness and urea concentration were captured during the constant-temperature evaporation of a liquid film deposited on an optically polished heated quartz flat.

  19. Sensitivity of surface resistance measurement of HTS thin films by ...

    Indian Academy of Sciences (India)

    field distribution in the resonators. The microwave surface resistance of the superconducting sample is then extracted from the measured Q value as a function of temperature. The sensitivity of the Rs measurement, that is, the relative change in the Q value with the change in the Rs value is determined for each resonator.

  20. Patterned thin metal film for the lateral resolution measurement of photoacoustic tomography

    Directory of Open Access Journals (Sweden)

    Kim Do-Hyun

    2012-07-01

    Full Text Available Abstract Background Image quality assessment method of photoacoustic tomography has not been completely standardized yet. Due to the combined nature of photonic signal generation and ultrasonic signal transmission in biological tissue, neither optical nor ultrasonic traditional methods can be used without modification. An optical resolution measurement technique was investigated for its feasibility for resolution measurement of photoacoustic tomography. Methods A patterned thin metal film deposited on silica glass provides high contrast in optical imaging due to high reflectivity from the metal film and high transmission from the glass. It provides high contrast when it is used for photoacoustic tomography because thin metal film can absorb pulsed laser energy. An US Air Force 1951 resolution target was used to generate patterned photoacoustic signal to measure the lateral resolution. Transducer with 2.25 MHz bandwidth and a sample submerged in water and gelatinous block were tested for lateral resolution measurement. Results Photoacoustic signal generated from a thin metal film deposited on a glass can propagate along the surface or through the surrounding medium. First, a series of experiments with tilted sample confirmed that the measured photoacoustic signal is what is propagating through the medium. Lateral resolution of the photoacoustic tomography system was successfully measured for water and gelatinous block as media: 0.33 mm and 0.35 mm in water and gelatinous material, respectively, when 2.25 MHz transducer was used. Chicken embryo was tested for biomedical applications. Conclusions A patterned thin metal film sample was tested for its feasibility of measuring lateral resolution of a photoacoustic tomography system. Lateral resolutions in water and gelatinous material were successfully measured using the proposed method. Measured resolutions agreed well with theoretical values.

  1. Thermal conductivity of a film of single walled carbon nanotubes measured with infrared thermal imager

    Science.gov (United States)

    Feng, Ya; Inoue, Taiki; Xiang, Rong; Chiashi, Shohei; Maruyama, Shigeo

    Heat dissipation has restricted the modern miniaturization trend with the development of electronic devices. Theoretically proven to be with high axial thermal conductivity, single walled carbon nanotubes (SWNT) have long been expected to cool down the nanoscale world. Even though the tube-tube contact resistance limits the capability of heat transfer of the bulk film, the high intrinsic thermal conductivity of SWNT still glorify the application of films of SWNT network as a thermal interface material. In this work, we proposed a new method to straightly measure the thermal conductivity of SWNT film. We bridged two cantilevered Si thin plate with SWNT film, and kept a steady state heat flow in between. With the infrared camera to record the temperature distribution, the Si plates with known thermal conductivity can work as a reference to calculate the heat flux going through the SWNT film. Further, the thermal conductivity of the SWNT film can be obtained through Fourier's law after deducting the effect of thermal radiation. The sizes of the structure, the heating temperature, the vacuum degree and other crucial impact factors are carefully considered and analyzed. The author Y. F. was supported through the Advanced Integration Science Innovation Education and Research Consortium Program by the Ministry of Education, Culture, Sport, Science and Technology.

  2. Novel method for the measurement of liquid film thickness during fuel spray impingement on surfaces.

    Science.gov (United States)

    Henkel, S; Beyrau, F; Hardalupas, Y; Taylor, A M K P

    2016-02-08

    This paper describes the development and application of a novel optical technique for the measurement of liquid film thickness formed on surfaces during the impingement of automotive fuel sprays. The technique makes use of the change of the light scattering characteristics of a metal surface with known roughness, when liquid is deposited. Important advantages of the technique over previously established methods are the ability to measure the time-dependent spatial distribution of the liquid film without a need to add a fluorescent tracer to the liquid, while the measurement principle is not influenced by changes of the pressure and temperature of the liquid or the surrounding gas phase. Also, there is no need for non-fluorescing surrogate fuels. However, an in situ calibration of the dependence of signal intensity on liquid film thickness is required. The developed method can be applied to measure the time-dependent and two-dimensional distribution of the liquid fuel film thickness on the piston or the liner of gasoline direct injection (GDI) engines. The applicability of this technique was evaluated with impinging sprays of several linear alkanes and alcohols with different thermo-physical properties. The surface temperature of the impingement plate was controlled to simulate the range of piston surface temperatures inside a GDI engine. Two sets of liquid film thickness measurements were obtained. During the first set, the surface temperature of the plate was kept constant, while the spray of different fuels interacted with the surface. In the second set, the plate temperature was adjusted to match the boiling temperature of each fuel. In this way, the influence of the surface temperature on the liquid film created by the spray of different fuels and their evaporation characteristics could be demonstrated.

  3. Development of an in-line X-ray reflectivity technique for metal film thickness measurement

    International Nuclear Information System (INIS)

    Windover, D.; Barnet, E.; Summers, J.; Gribbin, C.; Lu, T.-M.; Kumar, A.; Bakhru, H.; Lee, S.L.

    2001-01-01

    Non-destructive measurement of thin film (particularly metal film) thickness less than 10 nm has been a challenging task. In this work, we showed that it is possible to obtain the thickness of ultra-thin tantalum films within seconds using a fixed-angle, energy dispersive X-ray reflectivity technique by a conventional, low-energy X-ray copper or chromium source (20 kV/20 mA/400W) and using Parratt reflectivity modeling. We compared this fixed angle, energy dispersive result with more conventional fixed energy, angular dispersive reflectivity to establish the validity of the method and provide error estimates for fast thickness modeling. This X-ray technique is particularly useful for very thin diffusion barrier measurements in future microelectronics applications

  4. Methods of control for data processing systems over results of chamber film measurements

    International Nuclear Information System (INIS)

    Abdurakhimov, A.U.; Badalyan, S.G.; Dirner, A.; Ivanov, V.G.; Penev, V.N.

    1979-01-01

    Methods of control for data processing systems over the results of chamber film measurement are described. On the basis of analysis of parameters of event tracks, obtained in αp experiment, criteria are found to estimate coincidence of results of two independent measurements. Initial data for control are coordinates of tracks from chamber films or kinematic identification of events measured. As criteria for estimating the reliability of the results of the same events errors are used at measurement of track vertexes and points, differences between vertex space coordinates and event track paAameters at double measurements of latters and probabilities of identification of reaction various channels, X 2 values and missina masses. A specialized control software permits to obtain in a short computer time (2-5 min) data on the quality of measurements and possibility of their usage in experimental investigations

  5. SpotADAPT

    DEFF Research Database (Denmark)

    Kaulakiene, Dalia; Thomsen, Christian; Pedersen, Torben Bach

    2015-01-01

    by Amazon Web Services (AWS). The users aiming for the spot market are presented with many instance types placed in multiple datacenters in the world, and thus it is difficult to choose the optimal deployment. In this paper, we propose the framework SpotADAPT (Spot-Aware (re-)Deployment of Analytical...... execution within boundaries). Moreover, during the execution of the workload, SpotADAPT suggests a redeployment if the current spot instance gets terminated by Amazon or a better deployment becomes possible due to fluctuations of the spot prices. The approach is evaluated using the actual execution times...

  6. Film

    OpenAIRE

    Balint, Ruth; Dolgopolov, Greg

    2008-01-01

    From the beginning of the twentieth century, Sydney defined cosmopolitanism and modernity in the national imagination, and central to this image was the cinema: its technology, its architecture, its stars, its marketing and the stories it circulated to its audiences about Australia and the world. Though it is difficult to define a genre of Sydney film, Sydney provided the backdrop for a host of ideas about the city, and later suburbia. Sydney came to be seen as a ‘tinsel town’ of cultural ban...

  7. Surface dose measurement with Gafchromic EBT3 film for intensity modulated radiotherapy technique

    Science.gov (United States)

    Akbas, Ugur; Kesen, Nazmiye Donmez; Koksal, Canan; Okutan, Murat; Demir, Bayram; Becerir, Hatice Bilge

    2017-09-01

    Accurate dose measurement in the buildup region is extremely difficult. Studies have reported that treatment planning systems (TPS) cannot calculate surface dose accurately. The aim of the study was to compare the film measurements and TPS calculations for surface dose in head and neck cancer treatment using intensity modulated radiation therapy (IMRT). IMRT plans were generated for 5 head and neck cancer patients by using Varian Eclipse TPS. Quality assurance (QA) plans of these IMRT plans were created on rando phantoms for surface dose measurements. EBT3 films were cut in size of 2.5 x 2.5 cm2 and placed on the left side, right side and the center of larynx and then the films were irradiated with 6 MV photon beams. The measured doses were compared with TPS. The results of TPS calculations were found to be lower compared to the EBT3 film measurements at all selected points. The lack of surface dose calculation in TPS should be considered while evaluating the radiotherapy plans.

  8. MEASUREMENT OF MICROHARDNESS OF PHOTORESIST FILMS ON SILICON BY THE SCRATCHING METHOD

    Directory of Open Access Journals (Sweden)

    D. I. Brinkevich

    2016-01-01

    Full Text Available In recent years new types of resist for nano and submicronic lithography are intensively developed. As perspective materials for resist various polymeric compositions on a basis thermally and mechanically resistant polymers are considered. The purpose of the real work was studying of possibility of application of a microindentation and scratching methods for research of strength properties of films of the polymeric resist applied on plates of single-crystal silicon. As an example films of positive diazoquinonenovolak photoresist 1,0–5,0 μm thick which were applied on plates of silicon of various brands with a centrifugation method were used. The comparative analysis of an microindentation and scratching methods for microhardness measurement of structures photoresist-silicon is carried out. It is shown that the scratching an edge of a tetrahedral diamond pyramid (a scratching method is suitable for microhardness measurement of resistive films from 1,0 μm thick, at the same time the method of an microindentation can’t be used for measurements thin (h = 1,0–2,5 μm photoresist films. When using the load P = 1–2 g, more accurate values of microhardness gives the scratching method. Value of the microhardness determined by a scratching method is 20–40 % more than value of the microhardness received by a microindentation method. The increase in loading to 10 g leads to leveling of the specified distinctions – the values of a microhardness received by both methods coincide. Radiation of resistive films changed the structure of resist films. It is results to correlation of microhardness values given on measurement as by a scratching method, and by an indentation method. 

  9. Capacitance-voltage measurements in GaAs thin-film epitaxial structures

    Directory of Open Access Journals (Sweden)

    Gorev N. B.

    2009-10-01

    Full Text Available It is shown that capacitance–voltage characteristics that feature steeply dropping regions, in particular those of GaAs thin-film structures, may be measured at moderately small amplitudes of the measuring ac voltage (of the order of 100 mV at the expense of taking measurements at two different amplitudes. This conclusion is confirmed by the results of numerical calculation of the apparent capacitance of GaAs epitaxial structures.

  10. Nanoscale fatigue and fracture toughness measurements of multilayered thin film structures for digital micromirror devices

    Science.gov (United States)

    Wei, Guohua; Bhushan, Bharat; Jacobs, S. Joshua

    2004-07-01

    The digital micromirror device (DMD), which lies at the heart of Digital Light Processing™ projection display technology by Texas Instruments, Dallas, Texas, comprises a surface-micromachined array of mirrors on a base CMOS substrate. The nanomechanical properties of the thin-film structures used are important to the performance of the DMD. In this article, the nanoscale fatigue and fracture toughness of the single and multilayered thin film structures which are of interest in DMDs, i.e., TiN/Si, SiO2/Si, Al alloy/Si, TiN/Al alloy/Si, and SiO2/TiN/Al alloy/Si, were measured using nanoindentation techniques. The multilayered thin film structures with hard films on soft interlayer exhibit shorter fatigue life and higher ductility than the corresponding top hard films. The hardness plays an important role in determining the indentation fatigue life. Longer fatigue life is associated with higher hardness. The fracture toughness of TiN/Si and SiO2/Si was measured using the strain energy release method. .

  11. Real-time spot size camera for pulsed high-energy radiographic machines

    International Nuclear Information System (INIS)

    Watson, S.A.

    1993-01-01

    The focal spot size of an x-ray source is a critical parameter which degrades resolution in a flash radiograph. For best results, a small round focal spot is required. Therefore, a fast and accurate measurement of the spot size is highly desirable to facilitate machine tuning. This paper describes two systems developed for Los Alamos National Laboratory's Pulsed High-Energy Radiographic Machine Emitting X-rays (PHERMEX) facility. The first uses a CCD camera combined with high-brightness floors, while the second utilizes phosphor storage screens. Other techniques typically record only the line spread function on radiographic film, while systems in this paper measure the more general two-dimensional point-spread function and associated modulation transfer function in real time for shot-to-shot comparison

  12. Online terahertz thickness measurement in films and coatings

    Science.gov (United States)

    Duling, Irl N.; White, Jeffrey S.

    2017-02-01

    Pulsed terahertz systems are currently being deployed for online process control and quality control of multi-layered products for use in the building products and aerospace industries. While many laboratory applications of terahertz can allow waveforms to be acquired at rates of 1 - 40 Hz, online applications require measurement rates of in excess of 100Hz. The existing technologies of thickness measurement (nuclear, x-ray, or laser gauges) have rates between 100 and 1000 Hz. At these rates, the single waveform bandwidth must still remain at 2THz or above to allow thinner layers to be measured. In the applications where terahertz can provide unique capability (e.g. multi-layer thickness, delamination, density) long-term stability must be guaranteed within the tolerance required by the measurement. This can mean multi-day stability of less than a micron. The software that runs on these systems must be flexible enough to allow multiple product configurations, while maintaining the simplicity required by plant operators. The final requirement is to have systems that can withstand the environmental conditions of the measurement. This might mean qualification in explosive environments, or operation in hot, wet or dusty environments. All of these requirements can put restrictions on not only the voltage of electronic circuitry used, but also the wavelength and optical power used for the transmitter and receiver. The application of terahertz systems to online process control presents unique challenges that not only effect the physical design of the system, but can also effect the choices made on the terahertz technology itself.

  13. Non-destructive plasma frequency measurement for a semiconductor thin film using broadband surface plasmon polaritons

    Science.gov (United States)

    Yang, Tao; Ge, Jia-cheng; Li, Xing-ao; Stantchev, Rayko Ivanov; Zhu, Yong-yuan; Zhou, Yuan; Huang, Wei

    2018-03-01

    Measurement of the plasma frequency of a semiconductor film using broadband surface plasmon is demonstrated in this paper. We theoretically deduce a formula about the relation between plasma frequency and characteristic surface plasmon frequency. The characteristic surface plasmon frequency can be captured from the cut-off frequency of the transmission spectra of the broadband surface plasmon, which is used to measure the plasma frequency indirectly. The plasma frequencies of an intrinsic indium antimonide with and without optical illuminance are measured with a THz time-domain spectrometer at room temperature. The experimental measured plasma frequencies fit well with theoretical and simulation results. Compared with other methods, the proposed method has a special advantage on measuring the plasma frequency for a thin semiconductor film coated on other materials.

  14. Simultaneous measurement of 25 inflammatory markers and neurotrophins in neonatal dried blood spots by immunoassay with xMAP technology

    DEFF Research Database (Denmark)

    Skogstrand, Kristin; Thorsen, Poul; Nørgaard-Pedersen, Bent

    2005-01-01

    changed concentrations of inflammatory cytokines. Measurements on DBSS stored at -24 degrees C for >20 years showed that most cytokines are detectable in equal concentrations over time. CONCLUSIONS: The method can reliably measure 25 inflammatory markers and growth factors in DBSS. It has a large...... on flowmetric Luminex xMAP technology to measure inflammatory markers and neutrophins in DBSS. RESULTS: The high-capacity 25-plex multianalyte method measured 23 inflammatory and trophic cytokines, triggering receptor expressed on myeloid cells-1 (TREM-1), and C-reactive protein in two 3.2-mm punches from DBSS...

  15. Thin-film thickness measurement using x-ray peak ratioing in the scanning electron microscope

    International Nuclear Information System (INIS)

    Elliott, N.E.; Anderson, W.E.; Archuleta, T.A.; Stupin, D.M.

    1981-01-01

    The procedure used to measure laser target film thickness using a scanning electron microscope is summarized. This method is generally applicable to any coating on any substrate as long as the electron energy is sufficient to penetrate the coating and the substrate produces an x-ray signal which can pass back through the coating and be detected

  16. On-line display used with cathode ray tube film measuring device

    International Nuclear Information System (INIS)

    Fortney, L.R.; Robertson, W.J.

    1981-01-01

    An improved display has been developed for use on our computer controlled measuring device (RIPPLE). The device features a television image of the film and a digital presentation on the same X, Y display. The television image is formed using a modified left and right raster scan which can cover 50% more area in the same time as the traditional raster

  17. Raman measurements of epitaxial YBa2Cu3O7-δ films

    International Nuclear Information System (INIS)

    Burns, G.; Dacol, F.H.; Gield, C.A.; Gupta, A.; Holtzberg, F.; Koren, G.; Laibowitz, R.; McGuire, T.R.; Segmuller, A.P.; Worthington, T.K.

    1990-01-01

    The authors report Raman measurements on good (high J c ) epitaxial YBa 2 Cu 3 O -δ (Y123) films (δ ∼ 0). The results are compared to those from oriented Y123 single crystals. The comparisons are made for superconducting δ ∼ 0 and semiconducting δ ∼ 1 materials

  18. Thin-film resistance temperature detector array for the measurement of temperature distribution inside a phantom

    Science.gov (United States)

    Sim, Jai Kyoung; Hyun, Jaeyub; Doh, Il; Ahn, Bongyoung; Kim, Yong Tae

    2018-02-01

    A thin-film resistance temperature detector (RTD) array is proposed to measure the temperature distribution inside a phantom. HIFU (high-intensity focused ultrasound) is a non-invasive treatment method using focused ultrasound to heat up a localized region, so it is important to measure the temperature distribution without affecting the ultrasonic field and heat conduction. The present 25 µm thick PI (polyimide) film is transparent not only to an ultrasonic field, because its thickness is much smaller than the wavelength of ultrasound, but also to heat conduction, owing to its negligible thermal mass compared to the phantom. A total of 33 RTDs consisting of Pt resistors and interconnection lines were patterned on a PI substrate using MEMS (microelectromechanical systems) technology, and a polymer phantom was fabricated with the film at the center. The expanded uncertainty of the RTDs was 0.8 K. In the experimental study using a 1 MHz HIFU transducer, the maximum temperature inside the phantom was measured as 70.1 °C just after a HIFU excitation of 6.4 W for 180 s. The time responses of the RTDs at different positions also showed the residual heat transfer inside the phantom after HIFU excitation. HIFU results with the phantom showed that a thin-film RTD array can measure the temperature distribution inside a phantom.

  19. Photovoltaic material and device measurements workshop: focus on polycrystalline thin film cells

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    The general purpose of the workshop was to accelerate the development of thin film solar cells by improving the versatility and reliability of material and device measurement techniques. Papers were presented under the following sessions: structural/chemical session; optical/electro-optical session; charge transport session; and poster session. Each paper was processed for EDB.

  20. Nondestructive measurement of homoepitaxially grown GaN film thickness with Fourier transform infrared spectroscopy

    Science.gov (United States)

    Horikiri, Fumimasa; Narita, Yoshinobu; Yoshida, Takehiro

    2017-12-01

    In vertical devices containing GaN homoepitaxial layers on GaN substrates, the layer thickness is a key parameter that needs to be clarified before starting the device process. We applied Fourier transform infrared spectroscopy (FT-IR) to a homoepitaxially grown GaN film that consisted of an n--GaN layer. The estimated film thickness from the FT-IR spectrum agreed well with the results of cross-sectional scanning electron microscope cathodoluminescence images. This is the first report of nondestructive film thickness measurements for homoepitaxially grown GaN and indicates the applicability of FT-IR to the nondestructive inspection of vertical GaN power devices.

  1. Development of an experiment for measuring film cooling performance in supersonic flows

    Science.gov (United States)

    Maqbool, Daanish

    This thesis describes the development of an experiment for acquiring supersonic film cooling performance data in canonical configurations suitable for code validation. A methodology for selecting appropriate experimental conditions is developed and used to select test conditions in the UMD atmospheric pressure wind tunnel that are relevant to film cooling conditions encountered in the J-2X rocket engine. A new technique for inferring wall heat flux with 10% uncertainty from temperature-time histories of embedded sensors is developed and implemented. Preliminary heat flux measurements on the uncooled upper wall and on the lower wall with the film cooling flow turned off suggest that RANS solvers using Menter's SST model are able to predict heat flux within 15% in the far-field (> 10 injection slot heights) but are very inaccurate in the near-field. However, more experiments are needed to confirm this finding. Preliminary Schlieren images showing the shear layer growth rate are also presented.

  2. Method and apparatus for measurement of trap density and energy distribution in dielectric films

    Science.gov (United States)

    Maserjian, J. (Inventor)

    1976-01-01

    Trap densities in dielectric films are determined by tunnel injection measurements when the film is incorporated in an insulated-gate field effect transistor. Under applied bias to the transistor gate, carriers (electrons or holes) tunnel into traps in the dielectric film. The resulting space charge tends to change channel conductance. By feeding back a signal from the source contact to the gate electrode, channel conductance is held constant, and by recording the gate voltage as a function of time, trap density can be determined as a function of distance from the dielectric-semiconductor interface. The process is repeated with the gate bias voltage at different levels in order to determine the energy distribution of traps as a function of distance from the interface.

  3. A piezo-film-based measurement system for global haemodynamic assessment

    International Nuclear Information System (INIS)

    Clemente, Fabrizio; Cimmino, Pasquale; Arpaia, Pasquale

    2010-01-01

    A non-invasive piezo-film-based measurement method for haemodynamic assessment is proposed. The design of a system, able to reconstruct the blood pressure waveform online by dealing with problems arising from the piezo-film capacitive nature in the targeted frequency range (from quasi-dc up to 12 Hz), is illustrated. The system is based on a commercial piezo-film placed easily on the radial artery with a special brace without any discomfort for the patient. The analogical conditioning circuit and digital signal processing are continuously tuned with the signal from the sensor to reconstruct the blood pressure signal online. Diagnostic schema, based on physio-pathological models, have been implemented in order to compute online trends of max[dP(t)/d(t)] and volemic status highly useful for the intensivist and anaesthesiologist. The system was characterized by numerical simulation and experimental in vivo comparison to the traditional reference system

  4. Spectral interferometry including the effect of transparent thin films to measure distances and displacements

    International Nuclear Information System (INIS)

    Hlubina, P.

    2004-01-01

    A spectral-domain interferometric technique is applied for measuring mirror distances and displacements in a dispersive Michelson interferometer when the effect of transparent thin films coated onto the interferometer beam splitter and compensator is known. We employ a low-resolution spectrometer in two experiments with different amounts of dispersion in a Michelson interferometer that includes fused-silica optical sample. Knowing the thickness of the optical sample and the nonlinear phase function of the thin films, the positions of the interferometer mirror are determined precisely by a least-squares fitting of the theoretical spectral interferograms to the recorded ones. We compare the results of the processing that include and do not include the effect of transparent thin films (Author)

  5. Guided-mode-resonance-enhanced measurement of thin-film absorption.

    Science.gov (United States)

    Wang, Yifei; Huang, Yin; Sun, Jingxuan; Pandey, Santosh; Lu, Meng

    2015-11-02

    We present a numerical and experimental study of a guided-mode-resonance (GMR) device for detecting surface-bound light-absorbing thin films. The GMR device functions as an optical resonator at the wavelength strongly absorbed by the thin film. The GMR mode produces an evanescent field that results in enhanced optical absorption by the thin film. For a 100-nm-thick lossy thin film, the GMR device enhances its absorption coefficients over 26 × compared to a conventional glass substrate. Simulations show the clear quenching effect of the GMR when the extinction coefficient is greater than 0.01. At the resonant wavelength, the reflectance of the GMR surface correlates well with the degree of optical absorption. GMR devices are fabricated on a glass substrate using a surface-relief grating and a titanium-dioxide coating. To analyze a visible absorbing dye, the reflection coefficient of dye-coated GMR devices was measured. The GMR-based method was also applied to detecting acid gases, such as hydrochloric vapor, by monitoring the change in absorption in a thin film composed of a pH indicator, bromocresol green. This technique potentially allows absorption analysis in the visible and infrared ranges using inexpensive equipment.

  6. Oxidation/reduction studies on nanoporous platinum films by electrical resistance measurements

    Science.gov (United States)

    Zhu, Liangzhu; Kapoor, Siddharth; Parry, Quintin; Nahata, Ajay; Virkar, Anil V.

    2014-12-01

    Mechanisms and kinetics of surface reactions in nanoporous platinum films were investigated. Nanoporous films of platinum of ∼250 nm thickness were deposited on glass slides by co-sputtering Pt and carbon followed by subsequently burning off carbon in air at 450 °C. Electrical resistance was measured in air and in 10% H2 + nitrogen at 80 °C as a function of time. The change in electrical resistance was extremely fast when switched to the H2 + N2 atmosphere. When switched to air, the film resistance increased with time at a much slower rate. The increase in resistance in air was attributed to the formation of Pt-oxide on the internal surfaces of the nanoporous films. The kinetics of oxidation was described by a model which includes two surface kinetic steps and a diffusional step. The use of nanoporous films makes it possible to investigate mechanisms and kinetics of surface reactions by ensuring a large surface to volume ratio. Oxide scale thickness at 80 °C in air after several hours of oxidation was only sub-monolayer. Oxide scale thickness after 3 h at 450 °C was about 1 nm. Implications of the results for proton exchange membrane fuel cell (PEMFC) Pt catalyst degradation are discussed.

  7. Model of vortex dynamics in superconducting films in two-coil measurements of the coherence length

    Science.gov (United States)

    Lemberger, Thomas; Loh, Yen Lee

    In two-coil measurements on superconducting films, a magnetic field from a small coil is applied to the center of the film. When the amplitude of the ac field is increased, the film undergoes a transition from the ``Meissner'' state to a state with vortices and antivortices. Ultimately, the vortex density matches the applied magnetic field and field screening is negligible. Experimentally, the field at the transition is related to the superconducting coherence length, although a full theory of the relationship is lacking. We show that the mutual inductance between drive and pickup coils, on opposite sides of the film, as a function of ac field amplitude is well-described by a phenomenological model in which vortices and antivortices appear together in the film at the radius where the induced supercurrent is strongest, and then they move through a landscape of moderately strong vortex pinning sites. Work at OSU supported by DOE-Basic Energy Sciences through Grant No. FG02-08ER46533.

  8. Advanced platform for the in-plane ZT measurement of thin films

    Science.gov (United States)

    Linseis, V.; Völklein, F.; Reith, H.; Nielsch, K.; Woias, P.

    2018-01-01

    The characterization of nanostructured samples with at least one restricted dimension like thin films or nanowires is challenging, but important to understand their structure and transport mechanism, and to improve current industrial products and production processes. We report on the 2nd generation of a measurement chip, which allows for a simplified sample preparation process, and the measurement of samples deposited from the liquid phase using techniques like spin coating and drop casting. The new design enables us to apply much higher temperature gradients for the Seebeck coefficient measurement in a shorter time, without influencing the sample holder's temperature distribution. Furthermore, a two membrane correction method for the 3ω thermal conductivity measurement will be presented, which takes the heat loss due to radiation into account and increases the accuracy of the measurement results significantly. Errors caused by different sample compositions, varying sample geometries, and different heat profiles are avoided with the presented measurement method. As a showcase study displaying the validity and accuracy of our platform, we present temperature-dependent measurements of the thermoelectric properties of an 84 nm Bi87Sb13 thin film and a 15 μm PEDOT:PSS thin film.

  9. Simultaneous measurement of 25 inflammatory markers and neurotrophins in neonatal dried blood spots by immunoassay with xMAP technology

    DEFF Research Database (Denmark)

    Skogstrand, Kristin; Thorsen, Poul; Nørgaard-Pedersen, Bent

    2005-01-01

    on flowmetric Luminex xMAP technology to measure inflammatory markers and neutrophins in DBSS. RESULTS: The high-capacity 25-plex multianalyte method measured 23 inflammatory and trophic cytokines, triggering receptor expressed on myeloid cells-1 (TREM-1), and C-reactive protein in two 3.2-mm punches from DBSS...... potential for high-capacity analysis of DBSS in epidemiologic case-control studies and, with further refinements, in neonatal screening....

  10. [Investigation of multi-wavelength effect during the measurement of UV-enhanced film's emission spectrum].

    Science.gov (United States)

    Liu, Meng; Ni, Zheng-ji; Zhang, Da-wei; Huang, Yuan-shen; Zhuang, Song-lin

    2009-09-01

    The UV-responsive detector is a dual-use device for civilian and military after the laser and IR-responsive sensors. Typical image sensor coated with a layer of down-convert frequency thin film on it's photosurface to enhance UV response is the key technology of enhancing UV-response. The UV-enhanced thin film was made in the experimental laboratory using the Zn2SiO4:Mn phosphor by spin coating method. Two peaks at 520 and 560 nm respectively in the emission spectrum of the UV-enhanced film were found by SP1702 spectrograph when the excitation wavelength was 260 and 280 nm. The peaks were found in the process of experiment of measuring and counting the quantum efficiency of UV-enhanced thin film. But the light peaks at 520 and 560 nm are not the emission light peaks by the exciting light of 260 and 280 nm. The reason why the light at 520 and 560 nm is not the emission light was analyzed based on the measurement principle of grating spectrograph. The reasons for the multi-wavelength of light overlaps during the measurement of emission spectrum were also discussed. And the equipment used to separate the overlapped different wavelengths was designed, which will be used to resolve the problem of the overlap of multi-wavelength.

  11. Diode laser-based standoff absorption measurement of water film thickness in retro-reflection

    Science.gov (United States)

    Pan, R.; Brocksieper, C.; Jeffries, J. B.; Dreier, T.; Schulz, C.

    2016-09-01

    A dual-wavelength diode laser-based absorption sensor for standoff point measurements of water film thickness on an opaque surface is presented. The sensor consists of a diode laser source, a foil as backscattering target, and off-axis paraboloids for collecting the fraction of the laser radiation transmitted through the liquid layer via retro-reflection. Laser wavelengths in the near infrared at 1412 and 1353 nm are used where the temperature dependence of the liquid water absorption cross section is known. The lasers are fiber coupled and the detection of the retro-reflected light was accomplished through a multimode fiber and a single photodiode using time-division multiplexing. The water film thickness at a given temperature was determined from measured transmittance ratios at the two laser wavelengths. The sensor concept was first validated with measurement using a temperature-controlled calibration cell providing liquid layers of variable and known thickness between 100 and 1000 µm. Subsequently, the sensor was demonstrated successfully during recording the time-varying thickness of evaporating water films at fixed temperatures. The film thickness was recorded as a function of time at three temperatures down to 50 µm.

  12. A simple dried blood spot-method for in vivo measurement of ureagenesis by gas chromatography-mass spectrometry using stable isotopes.

    Science.gov (United States)

    Allegri, Gabriella; Deplazes, Sereina; Grisch-Chan, Hiu Man; Mathis, Déborah; Fingerhut, Ralph; Häberle, Johannes; Thöny, Beat

    2017-01-01

    Clinical management of inherited or acquired hyperammonemia depends mainly on the plasma ammonia level which is not a reliable indicator of urea cycle function as its concentrations largely fluctuate. The gold standard to assess ureagenesis in vivo is the use of stable isotopes. Here we developed and validated a simplified in vivo method with [ 15 N]ammonium chloride ([ 15 N]H 4 Cl) as a tracer. Non-labeled and [ 15 N]urea were quantified by GC-MS after extraction and silylation. Different matrices were evaluated for suitability of analysis. Ureagenesis was assessed in ornithine transcarbamylase (OTC)-deficient spf ash mice with compromised urea cycle function during fasted and non-fasted feeding states, and after rAAV2/8-vector delivery expressing the murine OTC-cDNA in liver. Blood (5μL) was collected through tail vein puncture before and after [ 15 N]H 4 Cl intraperitoneal injections over a two hour period. The tested matrices, blood, plasma and dried blood spots, can be used to quantify ureagenesis. Upon [ 15 N]H 4 Cl challenge, urea production in spf ash mice was reduced compared to wild-type and normalized following rAAV2/8-mediated gene therapeutic correction. The most significant difference in ureagenesis was at 30min after injection in untreated spf ash mice under fasting conditions (19% of wild-type). Five consecutive injections over a period of five weeks had no effect on body weight or ureagenesis. This method is simple, robust and with no apparent risk, offering a sensitive, minimal-invasive, and fast measurement of ureagenesis capacity using dried blood spots. The stable isotope-based quantification of ureagenesis can be applied for the efficacy-testing of novel molecular therapies. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. The Usability of a Pressure-Indicating Film to Measure the Teat Load Caused by a Collapsing Liner

    Directory of Open Access Journals (Sweden)

    Susanne Demba

    2016-09-01

    Full Text Available Prevention of damage to the teat and mastitis requires determination of the teat load caused by a collapsing liner. The aim of this study was to test a pressure-indicating film designed to measure the pressure between a collapsing liner and artificial teats. The Ultra Super Low and the Extreme Low pressure-indicating films were tested on two types of artificial teat. The experiments were performed with a conventional milking cluster equipped with round silicone liners. For each teat and film type, 30 repetitions were performed. Each repetition was performed with a new piece of film. Kruskal-Wallis tests were performed to detect differences between the pressure values for the different teats. The area of regions where pressure-indication color developed was calculated to determine the most suitable film type. Both film types measured the pressure applied to both artificial teats by the teat cup liner. Thus, the pressure-indicating films can be used to measure the pressure between a collapsing liner and an artificial teat. Based on the results of the present investigation, a pressure-indicating film with the measurement ranges of both film types combined would be an optimal tool to measure the overall pressure between an artificial teat and a collapsing liner.

  14. The Usability of a Pressure-Indicating Film to Measure the Teat Load Caused by a Collapsing Liner

    Science.gov (United States)

    Demba, Susanne; Elsholz, Sabrina; Ammon, Christian; Rose-Meierhöfer, Sandra

    2016-01-01

    Prevention of damage to the teat and mastitis requires determination of the teat load caused by a collapsing liner. The aim of this study was to test a pressure-indicating film designed to measure the pressure between a collapsing liner and artificial teats. The Ultra Super Low and the Extreme Low pressure-indicating films were tested on two types of artificial teat. The experiments were performed with a conventional milking cluster equipped with round silicone liners. For each teat and film type, 30 repetitions were performed. Each repetition was performed with a new piece of film. Kruskal-Wallis tests were performed to detect differences between the pressure values for the different teats. The area of regions where pressure-indication color developed was calculated to determine the most suitable film type. Both film types measured the pressure applied to both artificial teats by the teat cup liner. Thus, the pressure-indicating films can be used to measure the pressure between a collapsing liner and an artificial teat. Based on the results of the present investigation, a pressure-indicating film with the measurement ranges of both film types combined would be an optimal tool to measure the overall pressure between an artificial teat and a collapsing liner. PMID:27690033

  15. Automatic temperature compensating apparatus for measurement of thin films during deposition

    Science.gov (United States)

    Generosi, R.; Miriametro, A.

    1982-09-01

    This work describes the construction of a quartz resonator capable of measuring the thickness of deposited thin films with very high precision. A voltage-to-frequency converter is used as a reference oscillator. Temperature variations during the evaporation process, produced by both thermal irradiation and atomic bombardments, are monitored by an iron-constantan thermocouple which is used to generate a compensating signal at the input of the converter. The system also allows accurate measurement of the growth rate.

  16. A unified approach to deconvolution radiation spectra measured by radiochromic films

    CERN Document Server

    Stancic, V; Ljubenov, V

    2002-01-01

    A method for the evaluation of energy distribution of a radiation source on the basis of measured space distribution of deposited energy is proposed. The measured data were obtained by using radiochromic films. Mathematical modeling is defined as a Fredholm integral equation inversion problem. Negative solutions were treated as an additional condition expressed through undefined energy group boundaries, caused by virtue of the physical phenomenon of statistical uncertainty. Examples are given of the electron source and neutron radiation field.

  17. Effects of blood sample handling procedures on measurable inflammatory markers in plasma, serum and dried blood spot samples

    DEFF Research Database (Denmark)

    Skogstrand, K.; Thorsen, P.; Vogel, I.

    2008-01-01

    , and 30 days at the same temperatures. 27 inflammatory markers in serum and plasma and 25 markers in DBSS were measured by a previously validated multiplex sandwich immunoassay using Luminex xMAP technology. The measurable concentrations of several cytokines in serum and plasma were significantly......The interests in monitoring inflammation by immunoassay determination of blood inflammatory markers call for information on the stability of these markers in relation to the handling of blood samples. The increasing use of stored biobank samples for such ventures that may have been collected...... increased when blood samples were stored for a period of time before the centrifugation, for certain cytokines more than 1000 fold compared to serum and plasma isolated and frozen immediately after venepuncture. The concentrations in serum generally increased more than in plasma. The measurable...

  18. The analysis of track chamber photographs using flying spot digitizers

    CERN Multimedia

    Powell, Brian W

    1966-01-01

    A vast quantity of data pours from the experiments on particle accelerators throughout the world. For example, over 300 000 photographs per week came from the three bubble chambers operating on the CERN PS at the end of 1965. The conventional method of processing these bubble chamber photographs is for each one of them to be examined ('scanned') to see whether it records an interesting particle interaction. The interesting photographs are then passed to hand operated measuring machines to obtain precise measurements of the particle trajectories recorded on the film. Similar measurements are carried out on photographs taken in film spark chamber experiments. This article on the Flying Spot Digitizers at CERN describes one of the most fruitful attempts to speed and make more accurate the process of analysis of bubble and spark chamber photographs. There are two types of Flying Spot Digitizer at CERN — the HPD or Hough Powell Device (named after Professor Hough and the author who, together, initiated the devel...

  19. Qualitative cross-cultural exploration of vaginal bleeding/spotting symptoms and impacts associated with hormone therapy in post-menopausal women to inform the development of new patient-reported measurement tools.

    Science.gov (United States)

    Arbuckle, Rob; Humphrey, Louise; Abraham, Lucy; Dennerstein, Lorraine; Simon, James A; Mirkin, Sebastian; Bonner, Nicola; Walmsley, Steven; Tatlock, Sophi; Symonds, Tara

    2014-07-01

    To understand the vaginal bleeding/spotting experiences of postmenopausal (PM) women taking estrogen plus progestin therapies (EPT) and develop measures to assess these symptoms and their impact on women's daily lives in four countries. (1) Concept elicitation interviews were conducted with PM women in the US (n=14), Italy (n=15), Mexico (n=15) and China (n=15) to explore vaginal bleeding/spotting symptoms associated with EPT. The Post-Menopausal Bleeding Questionnaire (PMBQ) was also debriefed to evaluate understanding and comprehensiveness. (2) Based on concept elicitation, a single item electronic daily diary was developed and the PMBQ modified to form a 12-item impact measure. (3) The measures were pilot-tested and then cognitively debriefed with US women receiving EPT. All qualitative data was subject to thematic analysis. The Vaginal Bleeding/Spotting Daily Diary, (VBS-DD) and Post-Menopausal Bleeding Impact Questionnaire (PMBIQ) were developed in this study. Concept elicitation identified vaginal bleeding and spotting as important symptoms for women taking EPT, impacting their emotional wellbeing, social life, ability to move freely, clothing and sexual activity. Based on pilot testing and cognitive debriefing, women demonstrated good understanding of the VBS-DD and the PMBQ was reduced to 10 items due to conceptual redundancy. Women taking EPT in the US, China, Mexico and Italy reported vaginal bleeding/spotting symptoms that have a detrimental impact on their quality of life. Two new measures were developed to assess the severity and impact of vaginal bleeding/spotting specific to EPT. This work highlights the need for EPT-related symptoms to be a part of treatment decision-making. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Measuring and modeling maize evapotranspiration under plastic film-mulching condition

    Science.gov (United States)

    Li, Sien; Kang, Shaozhong; Zhang, Lu; Ortega-Farias, Samuel; Li, Fusheng; Du, Taisheng; Tong, Ling; Wang, Sufen; Ingman, Mark; Guo, Weihua

    2013-10-01

    Plastic film-mulching techniques have been widely used over a variety of agricultural crops for saving water and improving yield. Accurate estimation of crop evapotranspiration (ET) under the film-mulching condition is critical for optimizing crop water management. After taking the mulching effect on soil evaporation (Es) into account, our study adjusted the original Shuttleworth-Wallace model (MSW) in estimating maize ET and Es under the film-mulching condition. Maize ET and Es respectively measured by eddy covariance and micro-lysimeter methods during 2007 and 2008 were used to validate the performance of the Penman-Monteith (PM), the original Shuttleworth-Wallace (SW) and the MSW models in arid northwest China. Results indicate that all three models significantly overestimated ET during the initial crop stage in the both years, which may be due to the underestimation of canopy resistance induced by the Jarvis model for the drought stress in the stage. For the entire experimental period, the SW model overestimated half-hourly maize ET by 17% compared with the eddy covariance method (ETEC) and overestimated daily Es by 241% compared with the micro-lysimeter measurements (EL), while the PM model only underestimated daily maize ET by 6%, and the MSW model only underestimated half-hourly maize ET by 2% and Es by 7% during the whole period. Thus the PM and MSW models significantly improved the accuracy against the original SW model and can be used to estimate ET and Es under the film-mulching condition.

  1. Full-field measurement of dynamic stress by mechanoluminescence sensing film

    Science.gov (United States)

    Li, Chenshu; Xu, Chao-Nan; Imai, Yusuke; Bu, Nan

    2009-07-01

    Full-field measurement of dynamic stress has been realized by coating the surface of the test object metal with a upgrade mechanoluminescence sensing film of SrAl2O4:Eu (SAOE). Mechanoluminescent materials are attractive smart materials that can emit light induced by mechanical deformation. The ML sensing film of SAOE has been developed to make possible to visualize dynamic stress. Consequently this visualization technique has been become a promising experimental technique to investigate full-field stress analysis. In this paper we report the applications of the SAO ML sensing film for full-field stress analysis in aluminum alloy 5052 samples. Using the SAOE ML sensing film, the stress concentration produced by a circular hole was observed with the naked eyes in real time and the two-dimensional stress distribution was quantitatively measured; the complex and dynamic Portevin-Le Chatelier (PLC) effect, known as instability during plastic deformation, has been visualized, and the propagating characteristics of PLC bands were precisely investigated.

  2. Tear film flow and stability in normal Indian subjects

    Directory of Open Access Journals (Sweden)

    Maudgil S

    1989-01-01

    Full Text Available Tear film flow and stability studies were carried out in healthy population by Schirmer′s test-1 and tear film break-up-time (BUT measurements, respectively. The mean BUT observed was 13.87 +/- 4.79 seconds; however, in 22 percent of cases the values of BUT were even less than the lowest values laid down by various workers, from the Western countries. Maximum dry spots were located in the temporal quadrant.

  3. SU-F-T-176: Therapeutic Proton Beam Range Measurement Method with EBT3 Film

    Energy Technology Data Exchange (ETDEWEB)

    Lee, N [National Cancer Center, Goyang-si, Gyeonggi-do (Korea, Republic of)

    2016-06-15

    Purpose: Ocular proton therapy has the following advantages: i) sparing optic nerve, ii) the minimal dose is delivered to surrounding normal tissues. Since the proton therapy center was opened in 2007, 30 patients with ocular tumor have been treated at National Cancer Center using single scattering technique. To develop a solid eye phantom which can verify the output and the beam range with EBT3 film for independent patient QA in ocular proton therapy. Methods: The proton therapy is very effective to treat ocular tumor, because of the Bragg peak feature. In general, the beam shape of eye treatment is about 3 cm in diameter and the beam range is under 5 cm. However, proton therapy has uncertainty of beam range problem due to various stopping power of normal tissue, bone, air and so on, so that we should verify the beam range before treatment. For this purpose, a new PMMA phantom with wedge has been developed to use the film dosimetry and the ionization chamber. It is able to place a film on the slope of the phantom, which the spread out Bragg Peak by the water equivalent thickness value of PMMA can be made on the film. We considered to relation with quenching effect of proton energy and range for simple second check. In addition, the ionization chamber (Pin-point chamber, PTW 31014) can be inserted into a hole in the phantom to measure the absolute dose. Results: The output difference and beam range difference were less than 2% and 1.0 mm, respectively, between the measurement and the plan. Conclusion: An eye phantom was developed and its performance was evaluated successfully and it was useful to verify the output. Also with EBT3 film with the quenching effect for measurement depth-dose profile, range to patient QA.

  4. Study of thin film thickness measurement based on white light interference

    Science.gov (United States)

    Zheng, Yuanbo; Chu, Chunxiao; Wang, Xia

    2017-02-01

    One method for measuring thin film thickness was proposed in this paper, which based on white light interference. One parallel flat crystal was used to be the standard glass, and put another glass on it, to form one air wedge between them. The reflectance spectrum of two beams interference was measured by one spectrometer. By fitting the reflectance spectrum, wave numbers corresponding to every peak can be found, then using two beam interference theory, the air gap thickness at light incident point can be fitted. By measuring the air gap thickness at different positions, the flatness of measured surface also can be analyzed.

  5. Interferometric Measurements of Precursor Films Associated with Liquid Droplets on Solid Substrates.

    Science.gov (United States)

    McBrearty, Michael

    Precursor films associated with liquid droplets on solid substrates were measured using optical interferometry. De Gennes has given a theory which relates the shapes of these films to the strengths of van der Waals interactions between the molecules of the solid, liquid, and vapor, and to the spreading rates and contact angles of the macroscopically apparent droplet edges. Experimental efforts to evaluate the de Gennes theory should therefore include measurements in the macroscopic region as well as in the precursor region, but only one technique, microscopic imaging ellipsometry, is available which can measure in both regions. Its resolution is about 5 nm, which is insufficient for studying the thinnest parts of precursor films. We used optical interferometry with fractional fringe analysis and obtained a resolution that was similar: about +/- 4 nm. We monitored the spreading of silicone oil droplets on clean quartz wafers and on wafers coated with self-assembled monolayers of octadecyltrichlorosilane (OTS), which represented high and low energy substrates, respectively, and measured 22 precursor films. We were unable to test the theoretical predictions for the cutoff thicknesses and lengths because of the limited resolution of the measurements. Thickness profiles contained random fluctuations, but their shapes were approximately consistent with the predicted 1/r radial dependence. They were fitted to this function and yielded experimental estimates for the Hamaker constant, which characterizes the strength of the van der Waals interaction. The estimates were substantially scattered, but for precursors on clean wafers they spanned the value calculated from the Lifshitz theory. For precursors on OTS coated wafers, the experimentally determined Hamaker constants were uniformly larger, but no theoretical value is available for comparison. The measured thicknesses at the crossovers between the precursors and the macroscopic droplet regions agreed with the theoretical

  6. Simple measurement of light-interception by individual leaves in fruit vegetables by using an integrated solarimeter film

    International Nuclear Information System (INIS)

    Watanabe, S.; Nakano, Y.; Okano, K.

    2001-01-01

    Applicability of the integrated solarimeter film (Taisei Chemical Co. Ltd., Optleaf R-2D) for the measurement of amount of light-interception by individual leaves in fruit vegetables was investigated The fading rate of the film was highly correlated with the values measured by an integrated solarimeter at an open field, though the rate was depended on the air temperature during the measurement. Integrated solar radiation in a glasshouse could be estimated by the film as well as at an open field. Amount of light-interception by individual leaves of vertically trained watermelon plants could be measured by the film and light-interception characteristics of the plants could be expressed numerically. The integrated solarimeter film would be useful for analyzing light-interception characteristics in fruit vegetables

  7. Monitoring and intelligent control of electrode wear based on a measured electrode displacement curve in resistance spot welding

    Science.gov (United States)

    Zhang, Y. S.; Wang, H.; Chen, G. L.; Zhang, X. Q.

    2007-03-01

    Advanced high strength steels are being increasingly used in the automotive industry to reduce weight and improve fuel economy. However, due to increased physical properties and chemistry of high strength steels, it is difficult to directly substitute these materials into production processes currently designed for mild steels. New process parameters and process-related issues must be developed and understood for high strength steels. Among all issues, endurance of the electrode cap is the most important. In this paper, electrode wear characteristics of hot-dipped galvanized dual-phase (DP600) steels and the effect on weld quality are firstly analysed. An electrode displacement curve which can monitor electrode wear was measured by a developing experimental system using a servo gun. A neuro-fuzzy inference system based on the electrode displacement curve is developed for minimizing the effect of a worn electrode on weld quality by adaptively adjusting input variables based on the measured electrode displacement curve when electrode wear occurs. A modified current curve is implemented to reduce the effects of electrode wear on weld quality using a developed neuro-fuzzy system.

  8. Measurement of tritium in the free water of milk : spotting and quantifying some biases and proposing ways of improvement.

    Science.gov (United States)

    Le Goff, Pierre; Duda, Jean-Marie; Guétat, Philippe; Rambaud, Pauline; Mavon, Christophe; Vichot, Laurent; Badot, Pierre-Marie; Fromm, Michel

    2014-01-01

    As one of the three natural isotopes of hydrogen, tritium is ubiquitous and may potentially be present in any water or organic molecule that constitutes a biological matrix. Milk is one of the most frequently monitored foodstuffs in the vicinity of chronic release of radionuclides, as it is a very common food product and also because it integrates deposition on large areas of grass or crops at a local scale. Different parameters have been studied to assess their impact on the reliability of tritium measurements in the free water of milk. The volume of the sample, the technique used to extract the water and the level of dehydration modulate the results but in different ways: dispersion of results and under- or over-estimation of the tritium activity. The influence of sample storage and preparation has also been investigated. Methodological improvements of tritium measurements in the free water of milk are proposed. An original fractionation effect during distillation of milk is also described. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Estimating central tendency from a single spot measure: A closed-form solution for lognormally distributed biomarker data for risk assessment at the individual level.

    Science.gov (United States)

    Pleil, Joachim D; Sobus, Jon R

    2016-01-01

    Exposure-based risk assessment employs large cross-sectional data sets of environmental and biomarker measurements to predict population statistics for adverse health outcomes. The underlying assumption is that long-term (many years) latency health problems including cancer, autoimmune and cardiovascular disease, diabetes, and asthma are triggered by lifetime exposures to environmental stressors that interact with the genome. The aim of this study was to develop a specific predictive method that provides the statistical parameters for chronic exposure at the individual level based upon a single spot measurement and knowledge of global summary statistics as derived from large data sets. This is a profound shift in exposure and health statistics in that it begins to answer the question "How large is my personal risk?" rather than just providing an overall population-based estimate. This approach also holds value for interpreting exposure-based risks for small groups of individuals within a community in comparison to random individuals from the general population.

  10. A technique for measuring absolute toe pressures: evaluation of pressure-sensitive film techniques.

    Science.gov (United States)

    Tuckman, A S; Werner, F W; Fortino, M D; Spadaro, J A

    1992-05-01

    Although a number of pathologies of the forefoot in ballet dancers on pointe have been described, pressures and deforming forces have not been adequately measured. To evaluate the possible use of pressure-sensitive film (PSF) in measuring the pressures on the external soft tissues in such a confined space as the dancer's toe shoe, it was tested and calibrated with 20 cadaver toes. Each cadaver toe was internally stabilized and loaded longitudinally against PSF on a flat surface. The resultant films were analyzed with a video imaging system and the pressures and total forces were determined. Results showed that the linearity of the PSF to pressure had a regression value of 0.98. By using two sensitivity ranges of films, the total force measured by the PSF was found to be within 10% of the known applied force on each toe. The PSF, therefore, may very well be a useful and accurate method of measuring external soft tissue pressures on the forefoot.

  11. Modeling of stored charge in metallized biaxially oriented polypropylene film capacitors based on charging current measurement.

    Science.gov (United States)

    Li, Hua; Wang, Bowen; Li, Zhiwei; Liu, De; Lin, Fuchang; Dai, Ling; Zhang, Qin; Chen, Yaohong

    2013-10-01

    Metallized biaxially oriented polypropylene film (BOPP) capacitors are widely used in pulsed power systems. When the capacitor is used as the energy storage equipment under high electric field, more charges should be provided to maintain the voltage of the capacitor. This should be ascribed to the completion of the slow polarization which may take several hours or even longer. This paper focuses on the stored charge in metallized BOPP film capacitors. The modeling of the stored charge by the equivalent conversion of circuits is conducted to analyse the slow polarization in the BOPP film. The 3-RC network is proposed to represent the time-dependent charge stored in the capacitor. A charging current measurement system is established to investigate the charge storage property of the capacitor. The measurement system can measure the long time charging current with a sampling rate of 300 Hz. The total charge calculated by the charging current indicates that the stored charge in the capacitor under the electric field of 400 V/μm is 13.5% larger than the product of the voltage and the capacitance measured by the AC bridge. The nonlinear effect of the electric field on the slow polarization charge is also demonstrated. And the simulation of charge storage based on the 3-RC network can match well with the trend of the stored charge increasing with the time.

  12. Measurement for the MLC leaf velocity profile by considering the leaf leakage using a radiographic film

    International Nuclear Information System (INIS)

    Chow, James C L; Grigorov, Grigor N

    2006-01-01

    A method to measure the velocity profile of a multi-leaf collimator (MLC) leaf along its travel range using a radiographic film is reported by considering the intra-leaf leakage. A specific dynamic MLC field with leaves travelling from the field edge to the isocentre line was designed. The field was used to expose a radiographic film, which was then scanned, and the dose profile along the horizontal leaf axis was measured. The velocity at a sampling point on the film can be calculated by considering the horizontal distance between the sampling point and the isocentre line, dose at the sampling point, dose rate of the linear accelerator, the total leaf travel time from the field edge to isocentre line and the pre-measured dose rate of leaf leakage. With the leaf velocities and velocity profiles for all MLC leaves measured routinely, a comprehensive and simple QA for the MLC can be set up to test the consistency of the leaf velocity performance which is essential to the IMRT delivery using a sliding window technique. (note)

  13. A reliable control system for measurement on film thickness in copper chemical mechanical planarization system

    Science.gov (United States)

    Li, Hongkai; Qu, Zilian; Zhao, Qian; Tian, Fangxin; Zhao, Dewen; Meng, Yonggang; Lu, Xinchun

    2013-12-01

    In recent years, a variety of film thickness measurement techniques for copper chemical mechanical planarization (CMP) are subsequently proposed. In this paper, the eddy-current technique is used. In the control system of the CMP tool developed in the State Key Laboratory of Tribology, there are in situ module and off-line module for measurement subsystem. The in situ module can get the thickness of copper film on wafer surface in real time, and accurately judge when the CMP process should stop. This is called end-point detection. The off-line module is used for multi-points measurement after CMP process, in order to know the thickness of remained copper film. The whole control system is structured with two levels, and the physical connection between the upper and the lower is achieved by the industrial Ethernet. The process flow includes calibration and measurement, and there are different algorithms for two modules. In the process of software development, C++ is chosen as the programming language, in combination with Qt OpenSource to design two modules' GUI and OPC technology to implement the communication between the two levels. In addition, the drawing function is developed relying on Matlab, enriching the software functions of the off-line module. The result shows that the control system is running stably after repeated tests and practical operations for a long time.

  14. Forme Fruste Keratoconus Imaging and Validation via Novel Multi-Spot Reflection Topography

    Directory of Open Access Journals (Sweden)

    Anastasios John Kanellopoulos

    2013-10-01

    Full Text Available Background/Aims: This case report aims to evaluate safety, efficacy and applicability of anterior surface imaging in a patient with forme fruste keratoconus (FFKC based on a novel multi-spot, multicolor light-emitting-diode (LED tear film-reflection imaging technology Case Description: A 45-year-old male patient, clinically diagnosed with FFKC, with highly asymmetric manifestation between his eyes, was subjected to the multicolor-spot reflection topography. We investigated elevation and sagittal curvature maps comparatively with the multicolor-spot reflection topographer, a Placido topographer and a Scheimpflug imaging system. For the right eye, steep and flat keratometry values were 41.92 and 41.05 D with the multicolor spot-reflection topographer, 42.30 and 42.08 D with the Placido, and 41.95 and 41.19 D with the Scheimpflug system. For the left eye, steep and flat keratometry values were 41.86 and 41.19 D with the multicolor spot-reflection topographer, 42.06 and 41.66 D with the Placido topographer, and 41.96 and 41.66 D with the Scheimpflug camera. Average repeatability of the keratometry measurements was ±0.35 D for the multicolor spot-reflection topographer, ±0.30 D for the Placido, and ±0.25 D for the Scheimpflug camera. Very good agreement between the instruments was demonstrated on the elevation and curvature maps. Conclusion: The ease of use and the comparable results offered by the multicolor spot-reflection topographer, in comparison to established Placido and Scheimpflug imaging, as well as the increased predictability that may be offered by the multicolor spot-reflection topographer, may hold promise for wider clinical application, such as screening of young adults for early keratoconus and, in a much wider perspective, potential candidates for laser corneal refractive surgery.

  15. Forme Fruste Keratoconus Imaging and Validation via Novel Multi-Spot Reflection Topography.

    Science.gov (United States)

    Kanellopoulos, Anastasios John; Asimellis, George

    2013-01-01

    This case report aims to evaluate safety, efficacy and applicability of anterior surface imaging in a patient with forme fruste keratoconus (FFKC) based on a novel multi-spot, multicolor light-emitting-diode (LED) tear film-reflection imaging technology. A 45-year-old male patient, clinically diagnosed with FFKC, with highly asymmetric manifestation between his eyes, was subjected to the multicolor-spot reflection topography. We investigated elevation and sagittal curvature maps comparatively with the multicolor-spot reflection topographer, a Placido topographer and a Scheimpflug imaging system. For the right eye, steep and flat keratometry values were 41.92 and 41.05 D with the multicolor spot-reflection topographer, 42.30 and 42.08 D with the Placido, and 41.95 and 41.19 D with the Scheimpflug system. For the left eye, steep and flat keratometry values were 41.86 and 41.19 D with the multicolor spot-reflection topographer, 42.06 and 41.66 D with the Placido topographer, and 41.96 and 41.66 D with the Scheimpflug camera. Average repeatability of the keratometry measurements was ±0.35 D for the multicolor spot-reflection topographer, ±0.30 D for the Placido, and ±0.25 D for the Scheimpflug camera. Very good agreement between the instruments was demonstrated on the elevation and curvature maps. The ease of use and the comparable results offered by the multicolor spot-reflection topographer, in comparison to established Placido and Scheimpflug imaging, as well as the increased predictability that may be offered by the multicolor spot-reflection topographer, may hold promise for wider clinical application, such as screening of young adults for early keratoconus and, in a much wider perspective, potential candidates for laser corneal refractive surgery.

  16. Measurements of skin friction in water using surface stress sensitive films

    International Nuclear Information System (INIS)

    Crafton, J W; Fonov, S D; Jones, E G; Goss, L P; Forlines, R A; Fontaine, A

    2008-01-01

    The measurement of skin friction on hydrodynamic surfaces is of significant value for the design of advanced naval technology, particularly at high Reynolds numbers. Here we report on the development of a new sensor for measurement of skin friction and pressure that operates in both air and water. This sensor is based on an elastic polymer film that deforms under the action of applied normal and tangential loads. Skin friction and pressure gradients are determined by monitoring these deformations and then solving an inverse problem using a finite element model of the elastic film. This technique is known as surface stress sensitive films. In this paper, we describe the development of a sensor package specifically designed for two-dimensional skin friction measurements at a single point. The package has been developed with the goal of making two-dimensional measurements of skin friction in water. Quantitative measurements of skin friction are performed on a high Reynolds number turbulent boundary layer in the 12 inch water tunnel at Penn State University. These skin friction measurements are verified by comparing them to measurements obtained with a drag plate as well as by performing two-dimensional velocity measurements above the sensor using a laser Doppler velocimetry system. The results indicate that the sensor skin friction measurements are accurate to better than 5% and repeatable to better than 2%. The directional sensitivity of the sensor is demonstrated by positioning the sensor at several orientations to the flow. A final interesting feature of this sensor is that it is sensitive to pressure gradients, not to static pressure changes. This feature should prove useful for monitoring the skin friction on a seafaring vessel as the operating depth is changed

  17. Studying the Performance of Conductive Polymer Films as Textile Electrodes for Electrical Bioimpedance Measurements

    Science.gov (United States)

    Cunico, F. J.; Marquez, J. C.; Hilke, H.; Skrifvars, M.; Seoane, F.

    2013-04-01

    With the goal of finding novel biocompatible materials suitable to replace silver in the manufacturing of textile electrodes for medical applications of electrical bioimpedance spectroscopy, three different polymeric materials have been investigated. Films have been prepared from different polymeric materials and custom bracelets have been confectioned with them. Tetrapolar total right side electrical bioimpedance spectroscopy (EBIS) measurements have been performed with polymer and with standard gel electrodes. The performance of the polymer films was compared against the performance of the gel electrodes. The results indicated that only the polypropylene 1380 could produce EBIS measurements but remarkably tainted with high frequency artefacts. The influence of the electrode mismatch, stray capacitances and large electrode polarization impedance are unclear and they need to be clarified with further studies. If sensorized garments could be made with such biocompatible polymeric materials the burden of considering textrodes class III devices could be avoided.

  18. Studying the Performance of Conductive Polymer Films as Textile Electrodes for Electrical Bioimpedance Measurements

    International Nuclear Information System (INIS)

    Cunico, F J; Marquez, J C; Hilke, H; Skrifvars, M; Seoane, F

    2013-01-01

    With the goal of finding novel biocompatible materials suitable to replace silver in the manufacturing of textile electrodes for medical applications of electrical bioimpedance spectroscopy, three different polymeric materials have been investigated. Films have been prepared from different polymeric materials and custom bracelets have been confectioned with them. Tetrapolar total right side electrical bioimpedance spectroscopy (EBIS) measurements have been performed with polymer and with standard gel electrodes. The performance of the polymer films was compared against the performance of the gel electrodes. The results indicated that only the polypropylene 1380 could produce EBIS measurements but remarkably tainted with high frequency artefacts. The influence of the electrode mismatch, stray capacitances and large electrode polarization impedance are unclear and they need to be clarified with further studies. If sensorized garments could be made with such biocompatible polymeric materials the burden of considering textrodes class III devices could be avoided.

  19. Measurements of recombination coefficient of hydrogen atoms on plasma deposited thin films

    International Nuclear Information System (INIS)

    Drenik, A.; Vesel, A.; Mozetic, M.

    2006-01-01

    We have performed experiments in plasma afterglow in order to determine the recombination coefficients of plasma deposited thin films of tungsten and graphite. Plasma deposited films rather than bulk material were used in order to more closely emulate surface structure of plasma-facing material deposits in fusion reactors. We have also determined the recombination coefficient of 85250 borosilicate glass and Teflon. Plasma was created by means of a radio frequency generator in a mixture of argon and hydrogen at the pressures between 60 Pa and 280 Pa. The degree of dissociation of hydrogen molecules was found to be between 0.1 and 1. The H-atom density was measured by Fiber Optic Catalytic Probe. The recombination coefficient was determined by measuring the axial profile of the H-atom density and using Smith's side arm diffusion model. (author)

  20. Measurement of benzenethiol adsorption to nanostructured Pt, Pd, and PtPd films using Raman spectroelectrochemistry.

    Science.gov (United States)

    Pomfret, Michael B; Pietron, Jeremy J; Owrutsky, Jeffrey C

    2010-05-04

    Raman spectroscopy and electrochemical methods were used to study the behavior of the model adsorbate benzenethiol (BT) on nanostructured Pt, Pd, and PtPd electrodes as a function of applied potential. Benzenethiol adsorbs out of ethanolic solutions as the corresponding thiolate, and voltammetric stripping data reveal that BT is oxidatively removed from all of the nanostructured metals upon repeated oxidative and reductive cycling. Oxidative stripping potentials for BT increase in the order Pt < PtPd < Pd, indicating that BT adsorbs most strongly to nanoscale Pd. Yet, BT Raman scattering intensities, measured in situ over time scales of minutes to hours, are most persistent on the film of nanostructured Pt. Raman spectra indicate that adsorbed BT desorbs from nanoscale Pt at oxidizing potentials via cleavage of the Pt-S bond. In contrast, on nanoscale Pd and PtPd, BT is irreversibly lost due to cleavage of BT C-S bonds at oxidizing potentials, which leaves adsorbed sulfur oxides on Pd and PtPd films and effects the desulfurization of BT. While Pd and PtPd films are less sulfur-resistant than Pt films, palladium oxides, which form at higher potentials than Pt oxides, oxidatively desulfurize BT. In situ spectroelectrochemical Raman spectroscopy provides real-time, chemically specific information that complements the cyclic voltammetric data. The combination of these techniques affords a powerful and convenient method for guiding the development of sulfur-tolerant PEMFC catalysts.

  1. Measurement of Thermal Properties of Triticale Starch Films Using Photothermal Techniques

    Science.gov (United States)

    Correa-Pacheco, Z. N.; Cruz-Orea, A.; Jiménez-Pérez, J. L.; Solorzano-Ojeda, S. C.; Tramón-Pregnan, C. L.

    2015-06-01

    Nowadays, several commercially biodegradable materials have been developed with mechanical properties similar to those of conventional petrochemical-based polymers. These materials are made from renewable sources such as starch, cellulose, corn, and molasses, being very attractive for numerous applications in the plastics, food, and paper industries, among others. Starches from maize, rice, wheat, and potato are used in the food industry. However, other types of starches are not used due to their low protein content, such as triticale. In this study, starch films, processed using a single screw extruder with different compositions, were thermally and structurally characterized. The thermal diffusivity, thermal effusivity, and thermal conductivity of the biodegradable films were determined using photothermal techniques. The thermal diffusivity was measured using the open photoacoustic cell technique, and the thermal effusivity was obtained by the photopyroelectric technique in an inverse configuration. The results showed differences in thermal properties for the films. Also, the films microstructures were observed by scanning electron microscopy, transmission electron microscopy, and the crystalline structure determined by X-ray diffraction.

  2. Determining surface coverage of ultra-thin gold films from X-ray reflectivity measurements

    International Nuclear Information System (INIS)

    Kossoy, A.; Simakov, D.; Olafsson, S.; Leosson, K.

    2013-01-01

    The paper describes usage of X-ray reflectivity for characterization of surface coverage (i.e. film continuity) of ultra-thin gold films which are widely studied for optical, plasmonic and electronic applications. The demonstrated method is very sensitive and can be applied for layers below 1 nm. It has several advantages over other techniques which are often employed in characterization of ultra-thin metal films, such as optical absorption, Atomic Force Microscopy, Transmission Electron Microscopy or Scanning Electron Microscopy. In contrast to those techniques our method does not require specialized sample preparation and measurement process is insensitive to electrostatic charge and/or presence of surface absorbed water. We validate our results with image processing of Scanning Electron Microscopy images. To ensure precise quantitative analysis of the images we developed a generic local thresholding algorithm which allowed us to treat series of images with various values of surface coverage with similar image processing parameters. - Highlights: • Surface coverage/continuity of ultra-thin Au films (up to 7 nm) was determined. • Results from X-ray reflectivity were verified by scanning electron microscopy. • We developed local thresholding algorithm to treat non-homogeneous image contrast

  3. Robust measurement of thin-film photovoltaic modules exhibiting light-induced transients

    Science.gov (United States)

    Deceglie, Michael G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-09-01

    Light-induced changes to the current-voltage characteristic of thin-film photovoltaic modules (i.e. light-soaking effects) frustrate the repeatable measurement of their operating power. We describe best practices for mitigating, or stabilizing, light-soaking effects for both CdTe and CIGS modules to enable robust, repeatable, and relevant power measurements. We motivate the practices by detailing how modules react to changes in different stabilization methods. We also describe and demonstrate a method for validating alternative stabilization procedures, such as those relying on forward bias in the dark. Reliable measurements of module power are critical for qualification testing, reliability testing, and power rating.

  4. Robust Measurement of Thin-Film Photovoltaic Modules Exhibiting Light-Induced Transients: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Deceglie, Michael, G.; Silverman, Timothy J.; Marion, Bill; Kurtz, Sarah R.

    2015-09-09

    Light-induced changes to the current-voltage characteristic of thin-film photovoltaic modules (i.e. light-soaking effects) frustrate the repeatable measurement of their operating power. We describe best practices for mitigating, or stabilizing, light-soaking effects for both CdTe and CIGS modules to enable robust, repeatable, and relevant power measurements. We motivate the practices by detailing how modules react to changes in different stabilization methods. We also describe and demonstrate a method for validating alternative stabilization procedures, such as those relying on forward bias in the dark. Reliable measurements of module power are critical for qualification testing, reliability testing, and power rating.

  5. A method to investigate the electron scattering characteristics of ultrathin metallic films by in situ electrical resistance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, I. G.; Sousa, J. B. [IFIMUP and IN, Rua do campo Alegre, 687, 4169-007 Porto (Portugal); Department of Physics, FCUP, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Fermento, R. [Instituto de Microelectronica de Madrid, Isaac Newton 8, 28760 Tres Cantos, Madrid (Spain); Leitao, D. [IFIMUP and IN, Rua do campo Alegre, 687, 4169-007 Porto (Portugal)

    2009-07-15

    In this article, a method to measure the electrical resistivity/conductivity of metallic thin films during layer growth on specific underlayers is described. The in situ monitoring of an underlayer electrical resistance, its change upon the incoming of new material atoms/molecules, and the growth of a new layer are presented. The method is easy to implement and allows obtaining in situ experimental curves of electrical resistivity dependence upon film thickness with a subatomic resolution, providing insight in film growth microstructure characteristics, specular/diffuse electron scattering surfaces, and optimum film thicknesses.

  6. Measurement of modulation transfer functions of film-screen combinations with a lead bar pattern

    International Nuclear Information System (INIS)

    Hoeschen, D.; Mirande, W.

    1984-01-01

    A lead bar pattern, with continuously varying frequencies, has been used for measurement of modulation transfer functions of screen-film combinations. Although the highest usable frequency of the grid is only 3.4 mm -1 , evaluation of the first as well the third harmonic permits the expansion of the frequency range up to 10.2 mm -1 . Automatic evaluation of the images of the bar pattern gives reproducible results. These are presented. (orig.) [de

  7. How to Describe and Measure Obstacles of Narrative Immersion in a Film? The Wheel of Immersion as a Framework

    DEFF Research Database (Denmark)

    Bjørner, Thomas; Magnusson, Andreas; Nielsen, Robin Pascal

    2016-01-01

    The aim of this study is to describe and measure obstacles of narrative immersion in a film. Inspired by a literature review within both game research and film studies, we propose a circular model to describe the dynamic process of different levels of involvement viewers can be in while watching ...

  8. High-resolution hot-film measurement of surface heat flux to an impinging jet

    Science.gov (United States)

    O'Donovan, T. S.; Persoons, T.; Murray, D. B.

    2011-10-01

    To investigate the complex coupling between surface heat transfer and local fluid velocity in convective heat transfer, advanced techniques are required to measure the surface heat flux at high spatial and temporal resolution. Several established flow velocity techniques such as laser Doppler anemometry, particle image velocimetry and hot wire anemometry can measure fluid velocities at high spatial resolution (µm) and have a high-frequency response (up to 100 kHz) characteristic. Equivalent advanced surface heat transfer measurement techniques, however, are not available; even the latest advances in high speed thermal imaging do not offer equivalent data capture rates. The current research presents a method of measuring point surface heat flux with a hot film that is flush mounted on a heated flat surface. The film works in conjunction with a constant temperature anemometer which has a bandwidth of 100 kHz. The bandwidth of this technique therefore is likely to be in excess of more established surface heat flux measurement techniques. Although the frequency response of the sensor is not reported here, it is expected to be significantly less than 100 kHz due to its physical size and capacitance. To demonstrate the efficacy of the technique, a cooling impinging air jet is directed at the heated surface, and the power required to maintain the hot-film temperature is related to the local heat flux to the fluid air flow. The technique is validated experimentally using a more established surface heat flux measurement technique. The thermal performance of the sensor is also investigated numerically. It has been shown that, with some limitations, the measurement technique accurately measures the surface heat transfer to an impinging air jet with improved spatial resolution for a wide range of experimental parameters.

  9. Measurement of contact-line dissipation in a nanometer-thin soap film.

    Science.gov (United States)

    Guo, Shuo; Lee, Chun Huen; Sheng, Ping; Tong, Penger

    2015-01-01

    We report a direct measurement of the friction coefficient ξ(c) of two fluctuating contact lines formed on a fiber surface when a long glass fiber intersects the two water-air interfaces of a thin soap film. The glass fiber of diameter d in the range of 0.4-4 μm and length 100-300 μm is glued onto the front end of a rectangular cantilever used for atomic force microscopy. As a sensitive mechanical resonator, the hanging fiber probe can accurately measure a minute change of its viscous damping caused by the soap film. By measuring the broadening of the resonant peak of the hanging fiber probe with varying viscosity η of the soap film and different surface treatments of the glass fiber, we confirm that the contact line dissipation obeys a universal scaling law, ξ(c)=απdη, where the coefficient α=1.1±0.3 is insensitive to the change of liquid-solid contact angle. The experimental result is in good agreement with the numerical result based on the phase field model under the generalized Navier boundary conditions.

  10. Nonlinear surface impedance of YBCO thin films: Measurements, modeling, and effects in devices

    International Nuclear Information System (INIS)

    Oates, D.E.; Koren, G.; Polturak, E.

    1995-01-01

    High-T c thin films continue to be of interest for passive device applications at microwave frequencies, but nonlinear effects may limit the performance. To understand these effects we have measured the nonlinear effects may limit the performance. To understand these effects we have measured the nonlinear surface impedance Z s in a number of YBa 2 Cu 3 O 7-x thin films as a function of frequency from 1 to 18 GHz, rf surface magnetic field H rf to 1500 Oe, and temperature from 4 K to T c . The results at low H rf are shown to agree quantitatively with a modified coupled-grain model and at high H rf with hysteresis-loss calculations using the Bean critical-state model applied to a thin strip. The loss mechanisms are extrinsic properties resulting from defects in the films. We also report preliminary measurements of the nonlinear impedance of Josephson junctions, and the results are related to the models of nonlinear Z s . The implications of nonlinear Z s for devices are discussed using the example of a five-pole bandpass filter

  11. Laser-based diagnostics for the measurement of liquid water film thickness.

    Science.gov (United States)

    Greszik, Daniel; Yang, Huinan; Dreier, Thomas; Schulz, Christof

    2011-02-01

    Three different diagnostic techniques are investigated for measurement of the thickness of liquid water films deposited on a transparent quartz plate. The methods are based on laser-induced fluorescence (LIF) from low concentrations of a dissolved tracer substance and spontaneous Raman scattering of liquid water, respectively, both excited with 266 nm of radiation, and diode laser absorption spectroscopy (DLAS) in the near-infrared spectral region. Signal intensities are calibrated using liquid layers of known thickness between 0 and 1000 μm. When applied to evaporating liquid water films, the thickness values derived from the direct DLAS and Raman scattering measurements correlate well with each other as a function of time after the start of data recording, while the LIF signal derived thickness values decrease faster with time due to selective tracer evaporation from the liquid. The simultaneous application of the LIF with a tracer-free detection technique can serve as an in situ reference for quantitative film thickness measurements.

  12. A few remarks on TVS-EP film for measurement of dose distributions in high energy X rays

    International Nuclear Information System (INIS)

    Tsuda, Masayuki; Irifune, Toraji; Ohtani, Hiroki

    1997-01-01

    Dosimetry of small radiation fields for 6 MV and 18 MV x-rays have been evaluated with the use of silver halide film such as the XV2 Ready-pack (Kodak) and TVS-EP (CEA) films, and with the radiochromic film MD-55 (ISP Technologies). We compared the characteristics of the films with a 0.006 cm 3 ionization chamber (MC-110, Applied Engineering). The sensitivity of the radiochromic film is less than one hundredth of that of silver halide films. It was also that there were found linear relationship between a optical density of the radiochromic film and an irradiation dose only in a very narrow range. For this reason, the use of radiochromic film is unsuitable in the dosimetry for the accelerator. Compared to XV2 Ready-pack, there is linearity between optical density of the TVS-EP film and a much larger range of the irradiation dose. The sensitivity of the TVS-EP film is not dependent on the direction of the incident x-rays and is independent on the energy of the x-rays. The optical density of the TVS-EP film agreed with the ionization chamber dosimetry when the field size were varied. But, there is a limitation in using silver halide films in dosimetry. This limitation is due to various difficulties associated with intrinsic characteristics of the film, such as in developing processes and also in the measurement of the optical density. Therefore, dosimetry with the improved small size ionization chamber seems to be the most suitable on small field dosimetry. (author)

  13. Quantification in positron emission mammography (PEM) with planar detectors: contrast resolution measurements using a custom breast phantom and novel spherical hot-spots

    Science.gov (United States)

    Murthy, K.; Jolly, D.; Aznar, M.; Thompson, C. J.; Sciascia, P.; Loutfi, A.; Lisbona, R.; Gagnon, J. H.

    1999-12-01

    The authors have previously demonstrated that their Positron Emission Mammography-1 (PEM-1) system can successfully detect small (water. The heated solution is poured into spherical molds which are separated upon congealing to yield robust wall-less radioactive hot-spots. The hot-spots were uniform to within 1-5 parts in 100. Less than 0.1% of the total hot-spot activity leaked into the background in 30 minutes. Contrast resolution experiments have been performed with 12 mm and 16 mm diameter hot-spots in the breast phantom containing water with various amounts of background activity. In both cases, the observed contrast values agree well with the ideal values. In the case of the 12 mm hot-spot with a 350-650 keV energy window, image contrast differed from the ideal by an average of 11%. The image contrast for 12 mm hot-spot improved by 40% and the number of detected events decreased by 35% when the low energy threshold was increased from 300 keV to 450 keV.

  14. A Generic Algorithm to Estimate LAI, FAPAR and FCOVER Variables from SPOT4_HRVIR and Landsat Sensors: Evaluation of the Consistency and Comparison with Ground Measurements

    Directory of Open Access Journals (Sweden)

    Wenjuan Li

    2015-11-01

    Full Text Available The leaf area index (LAI and the fraction of photosynthetically active radiation absorbed by green vegetation (FAPAR are essential climatic variables in surface process models. FCOVER is also important to separate vegetation and soil for energy balance processes. Currently, several LAI, FAPAR and FCOVER satellite products are derived moderate to coarse spatial resolution. The launch of Sentinel-2 in 2015 will provide data at decametric resolution with a high revisit frequency to allow quantifying the canopy functioning at the local to regional scales. The aim of this study is thus to evaluate the performances of a neural network based algorithm to derive LAI, FAPAR and FCOVER products at decametric spatial resolution and high temporal sampling. The algorithm is generic, i.e., it is applied without any knowledge of the landcover. A time series of high spatial resolution SPOT4_HRVIR (16 scenes and Landsat 8 (18 scenes images acquired in 2013 over the France southwestern site were used to generate the LAI, FAPAR and FCOVER products. For each sensor and each biophysical variable, a neural network was first trained over PROSPECT+SAIL radiative transfer model simulations of top of canopy reflectance data for green, red, near-infra red and short wave infra-red bands. Our results show a good spatial and temporal consistency between the variables derived from both sensors: almost half the pixels show an absolute difference between SPOT and LANDSAT estimates of lower that 0.5 unit for LAI, and 0.05 unit for FAPAR and FCOVER. Finally, downward-looking digital hemispherical cameras were completed over the main land cover types to validate the accuracy of the products. Results show that the derived products are strongly correlated with the field measurements (R2 > 0.79, corresponding to a RMSE = 0.49 for LAI, RMSE = 0.10 (RMSE = 0.12 for black-sky (white sky FAPAR and RMSE = 0.15 for FCOVER. It is concluded that the proposed generic algorithm provides a good

  15. High efficacy of first-line ART in a West African cohort, assessed by dried blood spot virological and pharmacological measurements.

    Science.gov (United States)

    de Truchis, Pierre; Lê, Minh Patrick; Daou, Mamane; Madougou, Boubacar; Nouhou, Yacouba; Moussa Saley, Sahada; Sani, Achirou; Adehossi, Eric; Rouveix, Elisabeth; Saidou, Mamadou; Peytavin, Gilles; Delaugerre, Constance

    2016-11-01

    The objectives of this study were to determine the rate of viral success in HIV-infected patients on first-line ART by the assessment of dried blood spot (DBS) viral load (VL) and to assess the performance of DBS sampling for VL measurement, genotypic resistance and antiretroviral concentration determinations. HIV-infected patients treated for >1 year with first-line ART in Niamey, Niger were included. VL based on nucleic acid sequence-based amplification (NASBA) assay (limit of quantification 100 copies/mL); antiretroviral concentrations were interpreted using standard plasma cut-offs after extrapolation of blood to plasma results. Median (IQR) results are presented. Two hundred and eighteen patients (61% women), aged 41 (34-46) years, with 138 (56-235) CD4 cells/mm 3 at baseline were included. After 4 (2-6) years of follow-up under therapy, CD4 gain was +197 (98-372) cells/mm 3 ; 81% had VL ART in Niger. Adherence was high, according to antiretroviral concentrations, and the majority of failures were explained by selection of drug resistance mutations detected in the DBS genotype. Using DBS might improve the assessment of ART failure in HIV-infected patients in low-income countries. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  16. Laser based spot weld characterization

    Science.gov (United States)

    Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

    2016-02-01

    Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

  17. Raman spectroelectrochemistry of molecules within individual electromagnetic hot spots.

    Science.gov (United States)

    Shegai, Timur; Vaskevich, Alexander; Rubinstein, Israel; Haran, Gilad

    2009-10-14

    The role of chemical enhancement in surface-enhanced Raman scattering (SERS) remains a contested subject. We study SERS spectra of 4-mercaptopyridine molecules excited far from the molecular resonance, which are collected from individual electromagnetic hot spots at concentrations close to the single-molecule limit. The hot spots are created by depositing Tollen's silver island films on a transparent electrode incorporated within an electrochemical cell. Analysis of the intensity of the spectra relative to those obtained from individual rhodamine 6G molecules on the same surface provides a lower limit of approximately 3 orders of magnitude for the chemical enhancement. This large enhancement is likely to be due to a charge transfer resonance involving the transfer of an electron from the metal to an adsorbed molecule. Excitation at three different wavelengths, as well as variation of electrode potential from 0 to -1.2 V, lead to significant changes in the relative intensities of bands in the spectrum. It is suggested that while the bulk of the enhancement is due to an Albrecht A-term resonance Raman effect (involving the charge transfer transition), vibronic coupling provides additional enhancement which is sensitive to electrode potential. The measurement of potential-dependent SERS spectra from individual hot spots opens the way to a thorough characterization of chemical enhancement, as well to studies of redox phenomena at the single-molecule level.

  18. Measurements of the sensitivity and spatial resolution of radiochromic film using ion beams and X-rays

    Science.gov (United States)

    Schepis, M. J.; Shortino, J. P.; Crompton, K. R.; Stillman, C. R.; Freeman, C. G.; Nilson, P. M.; Sorce, C.; Sangster, T. C.

    2012-10-01

    Radiochromic film (RCF) is used to study protons and other ions that are accelerated from the rear side of targets illuminated with ultra-intense laser light. An experiment is underway to measure the sensitivity of RCF to protons and alpha particles of various energies using the 1.7 MV tandem Pelletron accelerator at SUNY Geneseo. An ion beam incident on a gold foil is used to expose the RCF to elastically scattered ions in a 28-inch diameter scattering chamber. The film is positioned in a circular arc in the chamber so the scattered ion fluence on the RCF strip varies as a function of the scattering angle. After exposure, the RCF is scanned in color negative transmission mode using an Epson 10000 XL flatbed scanner. The red channel of the resulting scan is used to determine the optical density of the film. The spatial resolution of the film was measured by blocking part of the film with a tantalum knife edge. The sensitivity of RCF to X-rays was also measured by exposing the film to X-rays produced by a biological irradiator. The response of the new Gafchromic HD-V2 radiochromic film is compared with the discontinued Gafchromic HD radiochromic film.

  19. A direct differential method for measuring thermal conductivity of thin films

    Science.gov (United States)

    Zeng, Yuqiang; Marconnet, Amy

    2017-04-01

    Over the past two decades, significant progress in the thermal metrology for thin films and wires has enabled new understanding of the thermal conductivity of nanostructures. However, a large variation in the measured thermal conductivity of similar nanostructured samples has been observed. In addition to potential differences from sample-to-sample, measurement uncertainty contributes to the observed variation in measured properties. Many now standard micro/nanoscale thermal measurement techniques require extensive calibration of the properties of the substrate and support structures and this calibration contributes to uncertainty. Within this work, we develop a simple, direct differential electrothermal measurement of thermal conductivity of micro/nanoscale sample films by extending conventional steady state electrothermal approaches. Specifically, we leverage a cross-beam measurement structure consisting of a suspended, composite heater beam (metal on silicon) with the sample structure (silicon) extending at a right angle from the center of the heater beam, in a configuration similar to the T-type measurements used for fibers and nanotubes. To accurately resolve the thermal conductivity of the sample, the steady-state Joule heating response of the cross-beam structure is measured. Then, the sample is detached from the heater beam with a Focused Ion Beam (FIB) tool enabling direct characterization of the composite heater beam thermal properties. The differential measurement of the structure before and after FIB cut enables direct extraction of the sample thermal conductivity. The effectiveness of this differential measurement technique is demonstrated by measuring thermal conductivity of a 200 nm silicon layer. Additionally, this new method enables investigation of the accuracy of conventional approaches for extracting sample thermal conductivity with the composite beam structure and conventional comparative approaches. The results highlight the benefits of the

  20. A direct differential method for measuring thermal conductivity of thin films.

    Science.gov (United States)

    Zeng, Yuqiang; Marconnet, Amy

    2017-04-01

    Over the past two decades, significant progress in the thermal metrology for thin films and wires has enabled new understanding of the thermal conductivity of nanostructures. However, a large variation in the measured thermal conductivity of similar nanostructured samples has been observed. In addition to potential differences from sample-to-sample, measurement uncertainty contributes to the observed variation in measured properties. Many now standard micro/nanoscale thermal measurement techniques require extensive calibration of the properties of the substrate and support structures and this calibration contributes to uncertainty. Within this work, we develop a simple, direct differential electrothermal measurement of thermal conductivity of micro/nanoscale sample films by extending conventional steady state electrothermal approaches. Specifically, we leverage a cross-beam measurement structure consisting of a suspended, composite heater beam (metal on silicon) with the sample structure (silicon) extending at a right angle from the center of the heater beam, in a configuration similar to the T-type measurements used for fibers and nanotubes. To accurately resolve the thermal conductivity of the sample, the steady-state Joule heating response of the cross-beam structure is measured. Then, the sample is detached from the heater beam with a Focused Ion Beam (FIB) tool enabling direct characterization of the composite heater beam thermal properties. The differential measurement of the structure before and after FIB cut enables direct extraction of the sample thermal conductivity. The effectiveness of this differential measurement technique is demonstrated by measuring thermal conductivity of a 200 nm silicon layer. Additionally, this new method enables investigation of the accuracy of conventional approaches for extracting sample thermal conductivity with the composite beam structure and conventional comparative approaches. The results highlight the benefits of the

  1. Electron scattering characteristics of polycrystalline metal transition films by in-situ electrical resistance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Trindade, I.G. [Faculdade de Ciencias da Universidade do Porto, Physics Department, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); IFIMUP and IN, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)], E-mail: i_trindade@msn.com; Leitao, D. [IFIMUP and IN, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Fermento, R. [Instituto de Microelectronica de Madrid, Isaac Newton 8, 28760 Tres Cantos, Madrid (Spain); Pogorelev, Y.; Sousa, J.B. [Faculdade de Ciencias da Universidade do Porto, Physics Department, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); IFIMUP and IN, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2009-08-15

    In-situ electrical resistance measurements were performed to obtain the scattering characteristics of very thin polycrystalline metal transition magnetic alloys grown by ion beam deposition (IBD) on specific underlayers. The experimental curves show size effects at small film thicknesses and important differences between Co{sub 85}Fe{sub 15} and Ni{sub 81}Fe{sub 19} thin layers grown on identical underlayers of Ta70 A/Ru13 A. The largest difference was observed in Ni{sub 81}Fe{sub 19} films grown on underlayers of amorphous Ta70 A. The experimental curves of electrical resistivity/conductivity variation with layer thickness were well fit within the Mayadas and Shatzkes (M-S) model, assuming specific formulations for grain growth with layer thickness.

  2. Measurement of transient atomic displacements in thin films with picosecond and femtometer resolution

    Directory of Open Access Journals (Sweden)

    M. Kozina

    2014-05-01

    Full Text Available We report measurements of the transient structural response of weakly photo-excited thin films of BiFeO3, Pb(Zr,TiO3, and Bi and time-scales for interfacial thermal transport. Utilizing picosecond x-ray diffraction at a 1.28 MHz repetition rate with time resolution extending down to 15 ps, transient changes in the diffraction angle are recorded. These changes are associated with photo-induced lattice strains within nanolayer thin films, resolved at the part-per-million level, corresponding to a shift in the scattering angle three orders of magnitude smaller than the rocking curve width and changes in the interlayer lattice spacing of fractions of a femtometer. The combination of high brightness, repetition rate, and stability of the synchrotron, in conjunction with high time resolution, represents a novel means to probe atomic-scale, near-equilibrium dynamics.

  3. Radiochromic Plastic Films for Accurate Measurement of Radiation Absorbed Dose and Dose Distributions

    DEFF Research Database (Denmark)

    McLaughlin, W. L.; Miller, Arne; Fidan, S.

    1977-01-01

    of many polymeric systems in industrial radiation processing. The result is that errors due to energy dependence of response of the radiation sensor are effectively reduced, since the spectral sensitivity of the dose meter matches that of the polymer of interest, over a wide range of photon and electron......Thin radiochromic dye films are useful for measuring large radiation absorbed doses (105–108 rads) and for high-resolution imaging of dose patterns produced by penetrating radiation beams passing through non-homogeneous media. Certain types of amino-substituted triarylmethane cyanides dissolved...... in polymeric solutions can be cast into flexible free-standing thin films of uniform thickness and reproducible response to ultraviolet and ionizing radiation. The increase in optical density versus energy deposited by radiation is linear over a wide range of doses and is for practical purposes independent...

  4. Conductance measurement by two-line probe method of polypyrrole nano-films formed on mica by admicellar polymerization

    International Nuclear Information System (INIS)

    Mou, C.-Y.; Yuan, W.-L.; Tsai, I-S.; O'Rear, Edgar A.; Barraza, Harry

    2008-01-01

    Measuring the electrical conductance is of importance in fabricating electronic devices based on semiconducting thin films. In this report, electrically conducting polypyrrole (PPy) nano-films were deposited on insulating mica plates by admicellar polymerization. It becomes difficult to measure such film conductance in the lateral direction due the nanometric thickness which only allows for very low electrical current. In order to understand the effects of surfactant on the film conductivity, morphological studies using atomic force microscopy and conductance measurements with a sub-fA multimeter were performed. Higher conductances were found for PPy thin films made using surfactant templates, than that of a bare mica surface. Using the two-line probe method by drawing two lines of silver glue 8 mm apart on the sample surface, the current-voltage curves of bare mica surface yielded a lateral conductance of 6.0 x 10 -13 S. In comparison, PPy thin films made using sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) as surfactant templates showed conductances of 1.2 x 10 -11 S and 7.7 x 10 -12 S, respectively. The higher conductances indicate tunneling, hopping, and percolation of charge carriers throughout the films. The lower-bound conductivities were calculated as 4.0 x 10 -3 S/cm and 2.6 x 10 -3 S/cm, measured based on the average thickness 2.3 nm for the SDS-PPy films and 2.4 nm for the CTAB-PPy films. Conductivities for both SDS and CTAB template PPy films are found to be of the same order

  5. Conductance measurement by two-line probe method of polypyrrole nano-films formed on mica by admicellar polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Mou, C.-Y. [Graduate Institute of Textile Engineering, Feng Chia University, Taichung 40724, Taiwan (China); Yuan, W.-L. [Department of Chemical Engineering, Feng Chia University, Taichung 40724, Taiwan (China)], E-mail: wyuan@fcu.edu.tw; Tsai, I-S. [Graduate Institute of Textile Engineering, Feng Chia University, Taichung 40724, Taiwan (China); O' Rear, Edgar A. [School of Chemical, Biological and Material Engineering, University of Oklahoma, Norman, OK 73019 (United States); Barraza, Harry [Unilever R and D HPC, Quarry Road East, Bebington, Wirral, CH63 3JW (United Kingdom)

    2008-10-01

    Measuring the electrical conductance is of importance in fabricating electronic devices based on semiconducting thin films. In this report, electrically conducting polypyrrole (PPy) nano-films were deposited on insulating mica plates by admicellar polymerization. It becomes difficult to measure such film conductance in the lateral direction due the nanometric thickness which only allows for very low electrical current. In order to understand the effects of surfactant on the film conductivity, morphological studies using atomic force microscopy and conductance measurements with a sub-fA multimeter were performed. Higher conductances were found for PPy thin films made using surfactant templates, than that of a bare mica surface. Using the two-line probe method by drawing two lines of silver glue 8 mm apart on the sample surface, the current-voltage curves of bare mica surface yielded a lateral conductance of 6.0 x 10{sup -13} S. In comparison, PPy thin films made using sodium dodecyl sulfate (SDS) and cetyl trimethyl ammonium bromide (CTAB) as surfactant templates showed conductances of 1.2 x 10{sup -11} S and 7.7 x 10{sup -12} S, respectively. The higher conductances indicate tunneling, hopping, and percolation of charge carriers throughout the films. The lower-bound conductivities were calculated as 4.0 x 10{sup -3} S/cm and 2.6 x 10{sup -3} S/cm, measured based on the average thickness 2.3 nm for the SDS-PPy films and 2.4 nm for the CTAB-PPy films. Conductivities for both SDS and CTAB template PPy films are found to be of the same order.

  6. Structural measurements of polymer-fullerene blend films for organic photovoltaics

    Science.gov (United States)

    Delongchamp, Dean

    2011-03-01

    Organic photovoltaic (OPV) technology has the potential to greatly lower the cost of solar cell fabrication by enabling ink-based deposition of active layers. In bulk heterojunction (BHJ) OPV devices, the power conversion efficiency critically depends on the distribution of the polymer absorber and the fullerene electron acceptor (e.g., the blend morphology). I will describe measurement methods to probe the structure of OPV devices, with a focus on the morphology of the BHJ layer. For example, the vertical distribution of absorber and electron acceptor in BHJ films follows segregation behavior similar to that of miscible polymer blends. The top (air) interface becomes rich in the polymer absorber, whereas the bottom interface composition depends on the substrate surface energy. Thin film transistors fabricated from BHJs can therefore exhibit ambipolar or hole-only transport depending on the dielectric, because of different interfacial segregation. We extend these results to practical photovoltaic devices by comparing BHJs cast upon hole transport layers that have similar work functions but different surface energies. This study includes the application of variable angle spectroscopic ellipsometry (VASE) to BHJ films, and emphasizes the importance of absorber anisotropy and vertical heterogeneity in the optical model. Additional results will describe the nanometer-scale structure in the BHJ interior. The application of solid-state nuclear magnetic resonance (SS-NMR) can reveal details about the segregation of absorber and acceptor in a BHJ film. Nanoscale BHJ morphology information can also be collected using tomographic transmission electron microscopy (TEM). Together these measurements allow us to reveal a detailed picture of BHJ morphology, explain how the morphology originates from materials and processing choices, and relate the morphology to device performance and stability.

  7. Home-cage anxiety levels in a transgenic rat model for Spinocerebellar ataxia type 17 measured by an approach-avoidance task: The light spot test.

    Science.gov (United States)

    Kyriakou, Elisavet I; Nguyen, Huu Phuc; Homberg, Judith R; Van der Harst, Johanneke E

    2017-08-18

    Measuring anxiety in a reliable manner is essential for behavioural phenotyping of rodent models such as the rat model for Spinocerebellar ataxia type 17 (SCA17) where anxiety is reported in patients. An automated tool for assessing anxiety within the home cage can minimize human intervention, stress of handling, transportation and novelty. We applied the anxiety test "light spot" (LS) (white led directed at the food-hopper) to our transgenic SCA17 rat model in the PhenoTyper 4500 ® to extend the knowledge of this automated tool for behavioural phenotyping and to verify an anxiety-like phenotype at three different disease stages for use in future therapeutic studies. Locomotor activity was increased in SCA17 rats at 6 and 9 months during the first 15min of the LS, potentially reflecting increased risk assessment. Both genotypes responded to the test with lower duration in the LS zone and higher time spent inside the shelter compared to baseline. We present the first data of a rat model subjected to the LS. The LS can be considered more biologically relevant than a traditional test as it measures anxiety in a familiar situation. The LS successfully evoked avoidance and shelter-seeking in rats. SCA17 rats showed a stronger approach-avoidance conflict reflected by increased activity in the area outside the LS. This home cage test, continuously monitoring pre- and post-effects, provides the opportunity for in-depth analysis, making it a potentially useful tool for detecting subtle or complex anxiety-related traits in rodents. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Absorbed dose distributions from ophthalmic106Ru/106Rh plaques measured in water with radiochromic film.

    Science.gov (United States)

    Hermida-López, Marcelino; Brualla, Lorenzo

    2018-02-05

    Brachytherapy with 106 Ru/ 106 Rh plaques offers good outcomes for small-to-medium choroidal melanomas and retinoblastomas. The dose measurement of the plaques is challenging, due to the small range of the emitted beta particles and steep dose gradients involved. The scarce publications on film dosimetry of 106 Ru/ 106 Rh plaques used solid phantoms. This work aims to develop a practical method for measuring the absorbed dose distribution in water produced by 106 Ru/ 106 Rh plaques using EBT3 radiochromic film. Experimental setups were developed to determine the dose distribution at a plane perpendicular to the symmetry axis of the plaque and at a plane containing the symmetry axis. One CCA and two CCX plaques were studied. The dose maps were obtained with the FilmQA Pro 2015 software, using the triple-channel dosimetry method. The measured dose distributions were compared to published Monte Carlo simulation and experimental data. A good agreement was found between measurements and simulations, improving upon published data. Measured reference dose rates agreed within the experimental uncertainty with data obtained by the manufacturer using a scintillation detector, with typical differences below 5%. The attained experimental uncertainty was 4.1% (k = 1) for the perpendicular setup, and 7.9% (k = 1) for the parallel setup. These values are similar or smaller than those obtained by the manufacturer and other authors, without the need of solid phantoms that are not available to most users. The proposed method may be useful to the users to perform quality assurance preclinical tests of 106 Ru/ 106 Rh plaques. © 2018 American Association of Physicists in Medicine.

  9. Steady heat conduction-based thermal conductivity measurement of single walled carbon nanotubes thin film using a micropipette thermal sensor.

    Science.gov (United States)

    Shrestha, R; Lee, K M; Chang, W S; Kim, D S; Rhee, G H; Choi, T Y

    2013-03-01

    In this paper, we describe the thermal conductivity measurement of single-walled carbon nanotubes thin film using a laser point source-based steady state heat conduction method. A high precision micropipette thermal sensor fabricated with a sensing tip size varying from 2 μm to 5 μm and capable of measuring thermal fluctuation with resolution of ±0.01 K was used to measure the temperature gradient across the suspended carbon nanotubes (CNT) film with a thickness of 100 nm. We used a steady heat conduction model to correlate the temperature gradient to the thermal conductivity of the film. We measured the average thermal conductivity of CNT film as 74.3 ± 7.9 W m(-1) K(-1) at room temperature.

  10. Application of Neutron Measurements to Advance Semiconductor Manufacturing: Next-Generation Lithography and Nanoporous Thin Films

    Science.gov (United States)

    Lin, Eric

    2010-03-01

    As feature sizes in microelectronic devices continue to decrease to sub-32 nm dimensions, new measurement methods are needed to understand the physical phenomena used in state-of-the-art lithography methods that may limit their fabrication and probe the structure and properties of new electronics materials. Neutron (and x-ray) beams have emerged as powerful probes of new manufactured structures with characteristic length scales ranging from (1 to 100) nm in thin films and in the bulk. In particular, X-ray reflectivity (XR), neutron reflectivity (NR), small angle neutron scattering (SANS), and small angle X-ray scattering (SAXS) can be applied in novel ways to address fundamental issues important to the microelectronics industry. This talk with highlight the application of neutron and x-ray measurement methods to investigate important problems in the development of photoresist materials used in lithography and of nanoporous low-dielectric-constant materials needed for next generation integrated circuits. Specific topics include: 1) the direct measurement of the reaction-diffusion front with nanometer resolution from ideal line-edges to probe image blur and roughness from photoacid diffusion 2) identification and measurement of a ``residual swelling fraction'' during the development and 3) measurements of the pore structure of low-dielectric constant thin films. Insights from these studies can provide guidelines and opportunities for the further extension of photoresist technology into the future and the integration of new materials into integrated circuits.

  11. Design of instantaneous liquid film thickness measurement system for conductive or non-conductive fluid with high viscosity

    Directory of Open Access Journals (Sweden)

    Yongxin Yu

    2017-06-01

    Full Text Available In the paper, a new capacitive sensor with a dielectric film coating was designed to measure the thickness of the liquid film on a flat surface. The measured medium can be conductive or non-conductive fluid with high viscosity such as silicone oil, syrup, CMC solution and melt. With the dielectric film coating, the defects caused by the humidity in a capacitor can be avoided completely. With a excitation frequency 0-20kHz, the static permittivity of capacitive sensor is obtained and stable when small thicknesses are monitored within the frequency of 0-3kHz. Based on the measurement principle, an experimental system was designed and verified including calibration and actual measurement for different liquid film thickness. Experimental results showed that the sensitivity, the resolution, repeatability and linear range of the capacitive sensor are satisfied to the liquid film thickness measurement. Finally, the capacitive measuring system was successfully applied to the water, silicone oil and syrup film thickness measurement.

  12. Accurate measurement of the piezoelectric coefficient of thin films by eliminating the substrate bending effect using spatial scanning laser vibrometry

    International Nuclear Information System (INIS)

    Leighton, Glenn J T; Huang, Zhaorong

    2010-01-01

    One of the major difficulties in measuring the piezoelectric coefficient d 33,f for thin films is the elimination of the contribution from substrate bending. We show by theoretical analysis and experimental measurements that by bonding thin film piezoelectric samples to a substantial holder, the substrate bending can be minimized to a negligible level. Once the substrate bending can be effectively eliminated, single-beam laser scanning vibrometry can be used to measure the precise strain distribution of a piezoelectric thin film under converse actuation. A significant strain increase toward the inside edge of the top electrode (assuming a fully covered bottom electrode) and a corresponding strain peak in the opposite direction just outside the electrode edge were observed. These peaks were found to increase with the increasing Poisson's ratio and transverse piezoelectric coefficient of the piezoelectric thin film. This is due to the non-continuity of the electric field at the edge of the top electrode, which leads to the concentration of shear stress and electric field in the vicinity of the electrode edge. The measured d 33,f was found to depend not only on the material properties such as the electromechanical coefficients of the piezoelectric thin films and elastic coefficients of the thin film and the substrate, but also on the geometry factors such as the thickness of the piezoelectric films, the dimensions of the electrode, and also the thickness of the substrate

  13. Spot market for uranium

    International Nuclear Information System (INIS)

    Colhoun, C.

    1982-01-01

    The spot market is always quoted for the price of uranium because little information is available about long-term contracts. A review of the development of spot market prices shows the same price curve swings that occur with all raw materials. Future long-term contracts will probably be lower to reflect spot market prices, which are currently in the real-value range of $30-$35. An upswing in the price of uranium could come in the next few months as utilities begin making purchases and trading from stockpiles. The US, unlike Europe and Japan, has already reached a supply and demand point where the spot market share is increasing. Forecasters cannot project the market price, they can only predict the presence of an oscillating spot or a secondary market. 5 figures

  14. Quantitative and high spatial resolution d33 measurement of piezoelectric bulk and thin films

    International Nuclear Information System (INIS)

    Shetty, Smitha; Yang, Jung In; Trolier-McKinstry, Susan; Stitt, Joe

    2015-01-01

    A single beam laser interferometer based on a modified Mirau detection scheme with a vertical resolution of ∼5 pm was developed for localized d 33 measurements on patterned piezoelectric films. The tool provides high spatial resolution (∼2 μm), essential for understanding scaling and processing effects in piezoelectric materials. This approach enables quantitative information on d 33 , currently difficult in local measurement techniques such as piezoresponse force microscopy. The interferometer is built in a custom microscope and employs a phase lock-in technique in order to detect sub-Angstrom displacements. d 33 measurements on single crystal 0.67PbMg 0.33 Nb 0.67 O 3 -0.33PbTiO 3 and bulk PbZrTiO 3 -5A ceramics demonstrated agreement within <3% with measurements using a double beam laser interferometer. Substrate bending contributions to out-of-plane strain, observed in thin continuous PbZr 0.52 Ti 0.48 O 3 films grown on Si substrates is reduced for electrode diameters smaller than 100 μm. Direct scanning across room temperature and 150 °C poled 5 μm and 10 μm features etched in 0.5 μm thick PbZr 0.52 Ti 0.48 O 3 films doped with 1% Nb confirmed minimal substrate contributions to the effective d 33,f . Furthermore, enhanced d 33,f values were observed along the feature edges due to partial declamping from the substrate, thus validating the application of single beam interferometry on finely patterned electrodes

  15. Elastic Measurements of Amorphous Silicon Films at mK Temperatures

    Science.gov (United States)

    Fefferman, Andrew; Maldonado, Ana; Collin, Eddy; Liu, Xiao; Metcalf, Tom; Jernigan, Glenn

    2017-06-01

    The low-temperature properties of glass are distinct from those of crystals due to the presence of poorly understood low-energy excitations. The tunneling model proposes that these are atoms tunneling between nearby equilibria, forming tunneling two-level systems (TLSs). This model is rather successful, but it does not explain the remarkably universal value of the mechanical dissipation Q^{-1} near 1 K. The only known exceptions to this universality are the Q^{-1} of certain thin films of amorphous silicon, carbon and germanium. Recently, it was found that Q^{-1} of amorphous silicon (a-Si) films can be reduced by two orders of magnitude by increasing the temperature of the substrate during deposition. According to the tunneling model, the reduction in Q^{-1} at 1 K implies a reduction in P0γ 2, where P0 is the density of TLSs and γ is their coupling to phonons. In this preliminary report, we demonstrate elastic measurements of a-Si films down to 20 mK. This will allow us, in future work, to determine whether P0 or γ is responsible for the reduction in Q^{-1} with deposition temperature.

  16. Novel measurement and monitoring system for forming processes based on piezoresistive thin film systems

    Science.gov (United States)

    Biehl, Saskia; Staufenbiel, Sebastian; Hauschild, Frank

    2009-05-01

    The investigation of a novel sensor system, integrated in the main load region of forming machines, is the challenge. Therefore it is important that the thin film system is multifunctional. It has an excellent tribological quality in combination with a piezoresistive behaviour. The layer system is deposited on the polished surface of a steel substrate. It has such geometries that it can be easily integrated in the drawing cushion of a deep drawing machine. The thin film sensor system exists out of a piezoresistive hydrogenated carbon layer, deposited in a PACVD process. Onto this layer arrays of chromium structures are deposited in a PVD process. The structures are protected against wear by an insulating silicon doped hydrogenated carbon layer. The whole thin film system has a thickness of about 9 μm. During the forming process the steel plate is in direct touch with the sensor system and moves over it. The position of the steel and the load distribution is measured in dependence on the forming stadium. The sensor system works as a control system to ensure that the shape of the product is perfect and without any cracks or creases.

  17. Film dosimetry using a smart device camera: a feasibility study for point dose measurements

    Science.gov (United States)

    Aland, Trent; Jhala, Ekta; Kairn, Tanya; Trapp, Jamie

    2017-10-01

    In this work, a methodology for using a smartphone camera, in conjunction with a light-tight box operating in reflective transmission mode, is investigated as a proof of concept for use as a film dosimetry system. An imaging system was designed to allow the camera of a smartphone to be used as a pseudo densitometer. Ten pieces of Gafchromic EBT3 film were irradiated to doses up to 16.89 Gy and used to evaluate the effects of reproducibility and orientation, as well as the ability to create an accurate dose response curve for the smartphone based dosimetry system, using all three colour channels. Results were compared to a flatbed scanner system. Overall uncertainty was found to be best for the red channel with an uncertainty of 2.4% identified for film irradiated to 2.5 Gy and digitised using the smartphone system. This proof of concept exercise showed that although uncertainties still exceed a flatbed scanner system, the smartphone system may be useful for providing point dose measurements in situations where conventional flatbed scanners (or other dosimetry systems) are unavailable or unaffordable.

  18. Transport Measurements on NEODYMIUM(1.85) CERIUM(.15) Copper OXYGEN(4-DELTA) Thin Films

    Science.gov (United States)

    Kussmaul, Andreas

    1992-01-01

    This work describes the synthesis and the study of the transport properties of thin films of Nd _{1.85}Ce_{.15 }CuO_{4-delta} carried out respectively at the IBM T. J. Watson Research Center in collaboration with Dr. A. Gupta, and at the Francis Bitter National Magnet Laboratory under the direction of Dr. P. M. Tedrow. The thin films were prepared by laser ablation of a stoichiometric target on heated substrates in a reactive ambient. The influence of the deposition parameters was studied, and the use of a nitreous oxide ambient was found to yield a clear improvement of the sample quality. The transport properties of the films were measured at low temperatures and in high magnetic fields. Non superconducting samples showed a strong, highly anisotropic, negative magnetoresistance that is consistent with two dimensional weak-localization. Superconducting samples show two dimensional fluctuation effects above T_{c}. The theory of fluctuations in a magnetic field was used to extract the position of H_{c2} (in the perpendicular direction) in the broad and almost featureless resistive transition, and the extracted values were fit to the theory of dirty superconductors. The angular dependence of the resistive transition was studied close to T _{c} and found to be somewhat better described by a two-dimensional model. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.).

  19. Dynamic measurement of liquid film thickness in stratified flow by using ultrasonic echo technique

    International Nuclear Information System (INIS)

    Serizawa, A.; Nagane, K.; Kamei, T.; Kawara, Z.; Ebisu, T.; Torikoshi, K.

    2004-01-01

    We developed a technique to measure time-dependent local film thickness in stratified air-water flow over a horizontal plate by using a time of flight of ultrasonic transmission. The ultrasonic echoes reflected at the liquid/air interfaces are detected by a conventional ultrasonic instrumentation, and the signals are analyzed by a personal computer after being digitalized by an A/D converter to give the time of flight for the ultrasonic waves to run over a distance of twice of the film thickness. A 3.8 mm diameter probe type ultrasonic transducer was used in the present work which transmits and receives 10 MHz frequency ultrasonic waves. The estimated spatial resolution with this arrangement is 0.075 mm in film thickness for water. The time resolution, which depends on both the A/D converter and the memory capacity was up to several tens Hz. We also discussed the sensitivity of the method to the inclination angle of the interfaces. (author)

  20. Uncertainty Analysis for Oil-Film Interferometry Skin-Friction Measurement Techniques

    Science.gov (United States)

    Naughton, Jonathan W.; Brown, James L.; Merriam, Marshal (Technical Monitor)

    1996-01-01

    Over the past 20 years, the use of oil-film interferometry to measure the skin friction coefficient (C(sub f) = tau/q where tau is the surface shear stress and q is the dynamic pressure) has increased. Different forms of this oil-film technique with various levels of accuracy and ease of use have been successfully applied in a wide range of flows. The method's popularity is growing due to its relative ease of implementation and minimal intrusiveness as well as an increased demand for C(sub f) measurements. Nonetheless, the accuracy of these methods has not been rigorously addressed to date. Most researchers have simply shown that the skin-friction measurements made using these techniques compare favorably with other measurements and theory, most of which are only accurate to within 5-20%. The use of skin-friction data in the design of commercial aircraft, whose drag at cruise is 50% skin-friction drag, and in the validation of computational fluid dynamics programs warrants better uncertainty estimates. Additional information is contained in the original extended abstract.

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

    International Nuclear Information System (INIS)

    Gotanda, R.; Takeda, Y.; Gotanda, T.; Oishi Hospital, Hiroshima; Tabuchi, A.; Kawasaki Hospital, Okayama; Yamamoto, K.; Osaka Cancer Prevention and Detection Centre, Osaka; Kuwano, T.; Osaka Medical Center for Cancer and Cardovascular Diseases, Osaka; Yatake, H.; Kaizuka City Hospital, Osaka; Katsuda, T.

    2009-01-01

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

  2. Development of Ultrafast Laser Flash Methods for Measuring Thermophysical Properties of Thin Films and Boundary Thermal Resistances

    Science.gov (United States)

    Baba, Tetsuya; Taketoshi, Naoyuki; Yagi, Takashi

    2011-11-01

    Reliable thermophysical property values of thin films are important to develop advanced industrial technologies such as highly integrated electronic devices, phase-change memories, magneto-optical disks, light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), semiconductor lasers (LDs), flat-panel displays, and power electronic devices. In order to meet these requirements, the National Metrology Institute of Japan of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) has developed ultrafast laser flash methods heated by picosecond pulse or nanosecond pulse with the same geometrical configuration as the laser flash method, which is the standard method to measure the thermal diffusivity of bulk materials. Since these pulsed light heating methods induce one-dimensional heat diffusion across a well-defined length of the specimen thickness, the absolute value of thermal diffusivity across thin films can be measured reliably. Using these ultrafast laser flash methods, the thermal diffusivity of each layer of multilayered thin films and the boundary thermal resistance between the layers can be determined from the observed transient temperature curves based on the response function method. The thermophysical properties of various thin films important for modern industries such as the transparent conductive films used for flat-panel displays, hard coating films, and multilayered films of next-generation phase-change optical disks have been measured by these methods.

  3. Determination of optical dispersion and film thickness of semiconducting disordered layers by transmission measurements: Application for chemically vapor deposited Si and SnO2 film

    Science.gov (United States)

    Davazoglou, D.

    1997-01-01

    A method is presented for the determination of the optical dispersion and thickness of thin semiconducting disordered layers, or stacks of such layers, deposited on fully or partly transparent substrates using transmission measurements. The method consists in fitting to the experimentally recorded spectra, theoretical ones, generated simulating the optical dispersion of the films involved with the help of the physical model proposed by Forouhi and Bloomer for amorphous semiconductors [Phys. Rev. B 34, 7018 (1986)]. The fit is made using standard regression analysis techniques that allow determination of the model parameters corresponding to these films. This method is applied for amorphous Si layers deposited on fused silica substrates by low pressure chemical vapor deposition (CVD) and SnO2 films grown by atmospheric pressure CVD on glass substrates and give results that are in agreement with those reported in the literature.

  4. A Manganin Thin Film Ultra-High Pressure Sensor for Microscale Detonation Pressure Measurement

    Directory of Open Access Journals (Sweden)

    Guodong Zhang

    2018-03-01

    Full Text Available With the development of energetic materials (EMs and microelectromechanical systems (MEMS initiating explosive devices, the measurement of detonation pressure generated by EMs in the microscale has become a pressing need. This paper develops a manganin thin film ultra-high pressure sensor based on MEMS technology for measuring the output pressure from micro-detonator. A reliable coefficient is proposed for designing the sensor’s sensitive element better. The sensor employs sandwich structure: the substrate uses a 0.5 mm thick alumina ceramic, the manganin sensitive element with a size of 0.2 mm × 0.1 mm × 2 μm and copper electrodes of 2 μm thick are sputtered sequentially on the substrate, and a 25 μm thick insulating layer of polyimide is wrapped on the sensitive element. The static test shows that the piezoresistive coefficient of manganin thin film is 0.0125 GPa−1. The dynamic experiment indicates that the detonation pressure of micro-detonator is 12.66 GPa, and the response time of the sensor is 37 ns. In a word, the sensor developed in this study is suitable for measuring ultra-high pressure in microscale and has a shorter response time than that of foil-like manganin gauges. Simultaneously, this study could be beneficial to research on ultra-high-pressure sensors with smaller size.

  5. Respiration and Heartbeat Measurement for Sleep Monitoring Using a Flexible AlN Piezoelectric Film Sensor

    Directory of Open Access Journals (Sweden)

    Nan BU

    2009-11-01

    Full Text Available Respiratory and heartbeat monitoring during sleep provides basic physiological information for diagnosis of sleep disorders. This paper proposes a new method for non-invasive and unconstrained measurement of respiration and heartbeat during sleep. A flexible piezoelectric film sensor made of aluminum nitride (AlN material is used for signal acquisition. The total thickness of this sensor is less than 40 μm; the thin thickness makes it imperceptible when integrated into a bed. In addition, the AlN film sensor has good sensitivity, so that pressure fluctuation due to respiration and heartbeat can be measured when a subject is lying on this sensor. The pressure fluctuation measured can be further separated into signals corresponding to respiration and heartbeat, respectively. In the proposed method, the signal separation is achieved using an algorithm based on empirical mode decomposition (EMD. From the experimental results, it was found that respiration and heartbeat signals can be successfully obtained with the proposed method.

  6. A Manganin Thin Film Ultra-High Pressure Sensor for Microscale Detonation Pressure Measurement.

    Science.gov (United States)

    Zhang, Guodong; Zhao, Yulong; Zhao, Yun; Wang, Xinchen; Wei, Xueyong; Ren, Wei; Li, Hui; Zhao, You

    2018-03-01

    With the development of energetic materials (EMs) and microelectromechanical systems (MEMS) initiating explosive devices, the measurement of detonation pressure generated by EMs in the microscale has become a pressing need. This paper develops a manganin thin film ultra-high pressure sensor based on MEMS technology for measuring the output pressure from micro-detonator. A reliable coefficient is proposed for designing the sensor's sensitive element better. The sensor employs sandwich structure: the substrate uses a 0.5 mm thick alumina ceramic, the manganin sensitive element with a size of 0.2 mm × 0.1 mm × 2 μm and copper electrodes of 2 μm thick are sputtered sequentially on the substrate, and a 25 μm thick insulating layer of polyimide is wrapped on the sensitive element. The static test shows that the piezoresistive coefficient of manganin thin film is 0.0125 GPa -1 . The dynamic experiment indicates that the detonation pressure of micro-detonator is 12.66 GPa, and the response time of the sensor is 37 ns. In a word, the sensor developed in this study is suitable for measuring ultra-high pressure in microscale and has a shorter response time than that of foil-like manganin gauges. Simultaneously, this study could be beneficial to research on ultra-high-pressure sensors with smaller size.

  7. EPMA-EDS surface measurements of interdiffusion coefficients between miscible metals in thin films

    International Nuclear Information System (INIS)

    Christien, F.; Pierson, J.F.; Hassini, A.; Capon, F.; Le Gall, R.; Brousse, T.

    2010-01-01

    A new technique is developed to study interdiffusion between two miscible metals. The technique is applied to the Ni-Pd system. It consists in measuring the change of apparent surface composition of a Pd substrate coated with an 800 nm Ni thin film during annealing at a given temperature. The measurement is carried out in-situ inside the chamber of a SEM (scanning electron microscope) by EPMA-EDS (electron probe microanalysis-energy dispersive X-ray spectroscopy). The experimental data are processed using a model that mixes the Fick's diffusion equations and the electron probe microanalysis equation. This process allows the determination of the mean interdiffusion coefficient at a given annealing temperature. The main advantages of the technique are the possible determination of interdiffusion coefficients in thin films and at very low temperature (down to 430 deg. C, i.e. ∼0.4 T m ), which is not achievable with other techniques conventionally used for the study of interdiffusion. The Ni-Pd mean interdiffusion coefficient is shown to follow an Arrhenius law (D-tilde c =6.32x10 -3 exp((178.8kJmol -1 )/(RT) )cm 2 s -1 ) between 430 deg. C and 900 deg. C, in relatively good agreement with previous interdiffusion measurements made on the Ni-Pd system at higher temperature.

  8. Determination of the optical constants of polymer light-emitting diode films from single reflection measurements

    International Nuclear Information System (INIS)

    Zhu Dexi; Shen Weidong; Ye Hui; Liu Xu; Zhen Hongyu

    2008-01-01

    We present a simple and fast method to determine the optical constant and physical thickness of polymer films from a single reflectivity measurement. A self-consistent dispersion formula of the Forouhi-Bloomer model was introduced to fit the measured spectral curves by a modified 'Downhill' simplex algorithm. Four widely used polymer light-emitting diodes materials: poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylenevinylene], poly(9,9-dioctylfluoreny-2,7-diyl) (PFO), poly(N-vinyl carbazole) and poly(3,4-ethylene dioxythiophene) : poly(styrenesulfonate) were investigated by this technique. The refractive indices over the whole visible region as well as the optical band gap extracted by this method agree well with those reported in the literature. The determined physical thicknesses present a deviation less than 4% compared with the experimental values measured by the stylus profiler. The influence of scattering loss on the fitted results is discussed to demonstrate the applicability of this technology for polymer films.

  9. Picosecond acoustic transmission measurements. I. Transient grating generation and detection of acoustic responses in thin metal films.

    Science.gov (United States)

    Slayton, Rebecca M; Nelson, Keith A

    2004-02-22

    The technique of impulsive stimulated thermal scattering is extended to backside measurement of acoustic wave packets that have propagated through thin metal films following their generation by pulsed optical excitation, heating, and thermal expansion at the front side. The acoustic transmission measurement at the backside substantially isolates the acoustic responses from thermal and electronic responses of the metal film that often dominate acoustic reflection signals measured from the front side, and permits straightforward measurement of the acoustic response generated by optical excitation at a substrate-thin film interface. It can thus better distinguish among different factors that limit the bandwidth of the acoustic wave packet, an issue of concern in the measurement of high frequency responses. The paper that follows demonstrates the application of the backside measurement to a study of high frequency structural relaxation in the glass-forming liquid glycerol. (c) 2004 American Institute of Physics.

  10. Use of dried spots of whole blood, plasma, and mother's milk collected on filter paper for measurement of human immunodeficiency virus type 1 burden

    NARCIS (Netherlands)

    Ayele, Workenesh; Schuurman, Rob; Messele, Tsehaynesh; Dorigo-Zetsma, Wendelien; Mengistu, Yohannes; Goudsmit, Jaap; Paxton, William A.; de Baar, Michel P.; Pollakis, Georgios

    2007-01-01

    We studied the use of dried spots of bodily fluids (plasma, whole blood, and mother's milk) on filter paper as a means of sample collection and storage for human immunodeficiency virus type 1 (HIV-1) viral load testing under stringent field conditions. Plasma placed directly in lysis buffer, which

  11. Polynomial-interpolation algorithm for van der Pauw Hall measurement in a metal hydride film

    Science.gov (United States)

    Koon, D. W.; Ares, J. R.; Leardini, F.; Fernández, J. F.; Ferrer, I. J.

    2008-10-01

    We apply a four-term polynomial-interpolation extension of the van der Pauw Hall measurement technique to a 330 nm Mg-Pd bilayer during both absorption and desorption of hydrogen at room temperature. We show that standard versions of the van der Pauw DC Hall measurement technique produce an error of over 100% due to a drifting offset signal and can lead to unphysical interpretations of the physical processes occurring in this film. The four-term technique effectively removes this source of error, even when the offset signal is drifting by an amount larger than the Hall signal in the time interval between successive measurements. This technique can be used to increase the resolution of transport studies of any material in which the resistivity is rapidly changing, particularly when the material is changing from metallic to insulating behavior.

  12. Spectrum analysis of turbulence in the canine ascending aorta measured with a hot-film anemometer.

    Science.gov (United States)

    Yamaguchi, T; Kikkawa, S; Tanishita, K; Sugawara, M

    1988-01-01

    We measured turbulence velocity in the canine ascending aorta using a hot-film anemometer. Blood flow velocity was measured at various points across the ascending aorta approximately 1.5-2 times the diameter downstream from the aortic valve. The turbulence spectrum was calculated and its characteristics were examined in connection with the mean Reynolds number and/or measuring positions. In the higher wave number range the values of the turbulence spectra were higher at larger mean Reynolds number. In the higher wave number range, the values of the turbulence spectra were higher at points closer to the centerline of the aorta, when the mean Reynolds number was relatively large. The patterns of the turbulence spectra at various points outside the boundary layer on the aortic wall were similar.

  13. Measurement of protection afforded by ultraviolet-absorbing window film using an in vitro model of photodamage.

    Science.gov (United States)

    Bernstein, Eric F; Schwartz, Mark; Viehmeyer, Robert; Arocena, Marvin S; Sambuco, Christopher P; Ksenzenko, Sergey M

    2006-04-01

    The effects of chronic sun damage including telangiectasias, solar lentigos, rhytides, enlarged pores, sagging skin, and pre-cancerous and cancerous growths are among the most common presenting complaints in a dermatologist's office. These changes are often worse on the driver's side of the face, emphasizing the role of UVA exposure received while driving in producing these changes. This study was undertaken to measure the ability of car window glass alone and in combination with ultraviolet (UV)-absorbing film to reduce UV-damage as measured using an established in vitro model of photoprotection. STUDY DESIGN MATERIALS AND METHODS: Using the 3T3 neutral red uptake photoprotection assay with solar simulating radiation (SSR) administered by a xenon arc solar simulator, we measured the photoprotection ability of auto glass, window film that filters UV radiation, and the combination of window film and auto glass. As measured by the 3T3 neutral red uptake photoprotection assay, auto glass reduced cell death from SSR by 29%, while window film reduced it 90%, and the combination of auto glass and film reduced cell death by 93%, when compared to unfiltered SSR. Window film that filters UV radiation results in dramatic reductions in cytotoxicity when measured by the neutral red uptake photoprotection assay. Widespread use of window film provides an ever-present barrier to ultraviolet A (UVA) exposure and could potentially reduce the detrimental effects of UVA, including photoaging, skin cancer, and ocular damage, such as cataracts. In addition, such film is essential for patients suffering from conditions sensitive to UV radiation, such as lupus erythematosis. Copyright 2006 Wiley-Liss, Inc.

  14. Direct measurement of free-energy barrier to nucleation of crystallites in amorphous silicon thin films

    Science.gov (United States)

    Shi, Frank G.

    1994-01-01

    A method is introduced to measure the free-energy barrier W(sup *), the activation energy, and activation entropy to nucleation of crystallites in amorphous solids, independent of the energy barrier to growth. The method allows one to determine the temperature dependence of W(sup *), and the effect of the preparation conditions of the initial amorphous phase, the dopants, and the crystallization methds on W(sup *). The method is applied to determine the free-energy barrier to nucleation of crystallites in amorphous silicon (a-Si) thin films. For thermally induced nucleation in a-Si thin films with annealing temperatures in the range of from 824 to 983 K, the free-energy barrier W(sup *) to nucleation of silicon crystals is about 2.0 - 2.1 eV regardless of the preparation conditions of the films. The observation supports the idea that a-Si transforms into an intermediate amorphous state through the structural relaxation prior to the onset of nucleation of crystallites in a-Si. The observation also indicates that the activation entropy may be an insignificant part of the free-energy barrier for the nucleation of crystallites in a-Si. Compared with the free-energy barrier to nucleation of crystallites in undoped a-Si films, a significant reduction is observed in the free-energy barrier to nucleation in Cu-doped a-Si films. For a-Si under irradiation of Xe(2+) at 10(exp 5) eV, the free-energy barrier to ion-induced nucleation of crystallites is shown to be about half of the value associated with thermal-induced nucleation of crystallites in a-Si under the otherwise same conditions, which is much more significant than previously expected. The present method has a general kinetic basis; it thus should be equally applicable to nucleation of crystallites in any amorphous elemental semiconductors and semiconductor alloys, metallic and polymeric glasses, and to nucleation of crystallites in melts and solutions.

  15. Mononucleosis spot test

    Science.gov (United States)

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  16. Technique charts for EC film: direct optical measurements to account for the effects of X-ray scatter

    International Nuclear Information System (INIS)

    Munro, Peter; Jordan, Kevin; Lewis, Craig; Heerema, Tim

    2001-01-01

    Purpose: To develop a method of measuring technique charts for enhanced contrast (EC) film, to demonstrate how X-ray scatter changes the response of EC film, and to generate technique charts for general use. Methods and Materials: We have developed a 'digital cassette' - consisting of a metal plate/phosphor screen, a light guide, a photodiode sensor, and an electrometer - that can be used to measure the light generated in the phosphor screen of the film cassette. In turn, these measurements can be used to generate technique charts for EC film. The digital cassette has been used to measure technique charts for 4-MV and 6-MV X-ray beams for a variety of different phantom thicknesses, field sizes, and phantom-to-cassette air gaps. Results and Discussion: We have observed that the signals generated in an ionization chamber located 9.4 cm behind a 30-cm-thick water-equivalent phantom increase by a factor of 1.9 when the field size is increased from 4x4 cm 2 to 40x40 cm 2 when irradiated by a 6-MV X-ray beam. However, the change in EC film response is a factor of 3.5 under the same conditions. Irradiations to optimally expose the EC film predicted by the digital cassette differ by up to 82% compared to those predicted by ion chamber measurements. Nevertheless, the technique charts measured using the digital cassette predict the response of the EC film to ±0.2 optical density. The overresponse of the EC film is most likely due to low-energy scattered photons, which interact with the high atomic number (Z=64) phosphor screen of the enhanced contrast localization cassette. Therefore, simple solutions, such as placing a high atomic number material above the enhanced contrast localization cassette, can reduce this contribution by scattered photons to the signal generated in the cassettes. Conclusions: We have developed a digital cassette that can make more accurate measurements of the technique charts for EC films. Our measurements show that under some conditions, X

  17. Nano-thermal transport array: An instrument for combinatorial measurements of heat transfer in nanoscale films

    International Nuclear Information System (INIS)

    McCluskey, Patrick J.; Vlassak, Joost J.

    2010-01-01

    The nano-Thermal Transport Array is a silicon-based micromachined device for measuring the thermal properties of nanoscale materials in a high-throughput methodology. The device contains an array of thermal sensors, each one of which consists of a silicon nitride membrane and a tungsten heating element that also serves as a temperature gauge. The thermal behavior of the sensors is described with an analytical model. The assumptions underlying this model and its accuracy are checked using the finite element method. The analytical model is used in a data reduction scheme that relates experimental quantities to materials properties. Measured properties include thermal effusivity, thermal conductivity, and heat capacity. While the array is specifically designed for combinatorial analysis, here we demonstrate the capabilities of the device with a high-throughput study of copper multi-layer films as a function of film thickness, ranging from 15 to 470 nm. Thermal conductivity results show good agreement with earlier models predicting the conductivity based on electron scattering at interfaces.

  18. Measurement of fluid dynamic loading on staphylococci bacteria bio-film structures using μPIV

    Science.gov (United States)

    Sherman, Erica; Moormeier, Derek; Bayles, Kenneth; Davidson, John; Ryu, Sangjin; Wei, Timothy

    2013-11-01

    Staphylococci bacteria are recognized as the most frequent cause of biofilm-associated infections. Although humans are regularly exposed to these bacteria without consequence, a localized infection can enter the bloodstream and lead to serious infections such as endocarditis, pneumonia, or toxic shock syndrome. The mechanics of staphylococci biofilm formation and dispersion through the bloodstream are not well known. It has recently been observed that under certain flow conditions, bacteria organize in tower-like structures which break and are transported downstream by the flow. The fundamental questions of interest are i) whether or not fluid mechanics plays a role in differentiating between film or tower formation and ii) whether or not the faulty towers are a bio-film propagation mechanism. This talk focuses on the application of μPIV to study this problem. Staphylococcus aureus bacteria were cultured in the Bioflux Fluxion square microchannel of a 65 by 65 um cross section, and subjected to a steady shear rate of 0.5 dynes. μPIV measurements were made to map the flow over and around a biofilm tower structure which occluded approximately 66% of the channel width. Data were recorded around the structure at a series of two dimensional planes, which when stacked vertically show a two dimensional flow field as a function of tower height. Measurements and control volume analysis will be presented quantifying forces acting on these structures.

  19. A new transmission methodology for quality assurance in radiotherapy based on radiochromic film measurements

    Science.gov (United States)

    do Amaral, Leonardo L.; Pavoni, Juliana F.; Sampaio, Francisco; Netto, Thomaz Ghilardi

    2015-01-01

    Despite individual quality assurance (QA) being recommended for complex techniques in radiotherapy (RT) treatment, the possibility of errors in dose delivery during therapeutic application has been verified. Therefore, it is fundamentally important to conduct in vivo QA during treatment. This work presents an in vivo transmission quality control methodology, using radiochromic film (RCF) coupled to the linear accelerator (linac) accessory holder. This QA methodology compares the dose distribution measured by the film in the linac accessory holder with the dose distribution expected by the treatment planning software. The calculated dose distribution is obtained in the coronal and central plane of a phantom with the same dimensions of the acrylic support used for positioning the film but in a source‐to‐detector distance (SDD) of 100 cm, as a result of transferring the IMRT plan in question with all the fields positioned with the gantry vertically, that is, perpendicular to the phantom. To validate this procedure, first of all a Monte Carlo simulation using PENELOPE code was done to evaluate the differences between the dose distributions measured by the film in a SDD of 56.8 cm and 100 cm. After that, several simple dose distribution tests were evaluated using the proposed methodology, and finally a study using IMRT treatments was done. In the Monte Carlo simulation, the mean percentage of points approved in the gamma function comparing the dose distribution acquired in the two SDDs were 99.92%±0.14%. In the simple dose distribution tests, the mean percentage of points approved in the gamma function were 99.85%±0.26% and the mean percentage differences in the normalization point doses were −1.41%. The transmission methodology was approved in 24 of 25 IMRT test irradiations. Based on these results, it can be concluded that the proposed methodology using RCFs can be applied for in vivo QA in RT treatments. PACS number: 87.55.Qr, 87.55.km, 87.55.N‐ PMID

  20. Reflectometric measurement of n-hexane adsorption on ZnO2 nanohybrid film modified by hydrophobic gold nanoparticles

    Science.gov (United States)

    Sebők, Dániel; Csapó, Edit; Ábrahám, Nóra; Dékány, Imre

    2015-04-01

    Zinc-peroxide/poly(styrenesulfonate) nanohybrid thin films (containing 20 bilayers: [ZnO2/PSS]20, d ∼ 500 nm) were prepared using layer-by-layer (LbL) method. The thin film surface was functionalized by different surface modifying agents (silanes, alkylthiols and hydrophobized nanoparticles). Based on the experimental results of quartz crystal microbalance (QCM) and contact angle measurements (as prequalifications) the octanethiol covered gold nanoparticles (OT-AuNPs) were selected for further vapour adsorption studies. Reflectometric interference spectroscopy (RIfS) was used to measure n-hexane vapour adsorption on the original and modified nanohybrid films in a gas flow platform. The thin film provides only the principle of the measurement (by interference phenomenon), the selectivity and hydrophobicity is controlled and enhanced by surface functionalization (by dispersion interaction between the alkyl chains). The interference pattern shift (Δλ) caused by the increase of the optical thickness of the thin film due to vapour adsorption was investigated. It was found that due to the surface functionalization by hydrophobic nanoparticles the effect of water vapour adsorption decreased significantly, while for n-hexane opposite tendency was observed (the effective refractive index and thus the interference pattern shift increased drastically). The correlation between QCM technique and optical method (RIfS) was specified: linear specific adsorbed amount vs. wavelength shift calibration curves were determined in the pr = 0-0.4 relative vapour pressure range. The thin film is suitable for sensorial application (e.g. volatile organic compound/VOC sensor).

  1. Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements.

    Science.gov (United States)

    Abukassem, I; Bero, M A

    2015-04-01

    Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC(®) film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A633) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11% for spectral absorbance measurements and 15% for OD measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Effects of wall temperature on skin-friction measurements by oil-film interferometry

    International Nuclear Information System (INIS)

    Bottini, H; Kurita, M; Iijima, H; Fukagata, K

    2015-01-01

    Wind-tunnel skin-friction measurements with thin-oil-film interferometry have been taken on an aluminum sample to investigate the effects of wall temperature on the accuracy of the technique. The sample has been flush-mounted onto a flat plate with an electric heater at its bottom and mirror-smooth temperature-sensitive paint sprayed on its top. The heater has varied the sample temperature from ambient to 328 K, and the paint has permitted wall temperature measurements on the same area of the skin-friction measurements and during the same test. The measured wall temperatures have been used to calculate the correct oil viscosities, and these viscosities and the constant nominal viscosity at 298 K have been used to calculate two different sets of skin-friction coefficients. These sets have been compared to each other and with theoretical values. This comparison shows that the effects of wall temperature on the accuracy of skin-friction measurements are sensible, and more so as wall temperature differs from 298 K. Nonetheless, they are effectively neutralized by the use of wall temperature measurements in combination with the correct oil viscosity–temperature law. In this regard, the special temperature-sensitive paint developed for this study shows advantages with respect to more traditional wall temperature measurement techniques. (paper)

  3. Extraction of lateral eigenmode properties in thin film bulk acoustic wave resonator from interferometric measurements

    Science.gov (United States)

    Kokkonen, Kimmo; Pensala, Tuomas; Meltaus, Johanna; Kaivola, Matti

    2010-04-01

    A heterodyne laser interferometer is used to study acoustic wave fields excited in a 1.8 GHz AlN thin film bulk acoustic wave resonator. The electrical response of the resonator exhibits a strong thickness resonance onto which spurious modes, caused by lateral standing plate waves, are superposed. Optical interferometer measurements are used to extract dispersion curves of the laterally propagating waves responsible for the spurious responses. A discrete eigenmode spectrum due to the finite lateral dimensions of the resonator is observed. An equivalent circuit model for a multimode resonator is fitted to the mechanical resonator response extracted along a single curve in the dispersion diagram, and is used to determine properties, such as Q-values, of the individual lateral eigenmodes. Measured wave field images, extracted dispersion curves, and the eigenmode spectrum with the model fitting results are presented.

  4. Laser-induced fluorescence measurement of the oil film thickness in an internal combustion engine

    Science.gov (United States)

    Ostroski, Greg M.; Ghandhi, Jaal B.

    1997-11-01

    The use of a fluorescent dopant molecule to enhance the natural fluorescence of motor oils, and allow quantitative determination of temperature and film thickens in internal combustion engines has been investigated. Measurement of the fluorescence as a function of temperature were made with neat Mobil 1, and solutions of the dopant BTBP in mineral oil and Mobil 1. The fluorescence yield of neat Mobil 1 was found to vary by 30 percent over the temperature range explored, but the spectral characteristics, as measured with bandpass filters, were unaffected by temperature. The BTBP fluorescence was found to increase significantly with temperature, and it was found the narrower regions in the spectrum increased proportionally more than the fluorescence collected over the entire spectrum, allowing a determination of temperature to be made which can then be used to correct for the change in fluorescence yield. Solutions in Mobil 1 showed a smaller increase than that observed in mineral oil.

  5. Radiation dose measurements of the insertion devices using radiachromic film dosimeters

    International Nuclear Information System (INIS)

    Alderman, J.; Semones, E.; Job, P. K.

    2004-01-01

    The Advanced Photon Source (APS) uses Nd-Fe-B permanent magnets in the insertion devices to produce x-rays for scientific research [1,2]. Earlier investigations have exhibited varying degrees of demagnetization of these magnets [3] due to irradiation from electron beams [4,5,6], 60 Co γ-rays [5], and high-energy neutrons [7,8]. Radiation-induced demagnetization has been observed in the APS insertion devices [9] and was first measured in December of 2001. Partial demagnetization has also been observed in insertion devices at the European Synchrotron Radiation Facility (ESRF) [4,6], where Nd-Fe-B permanent magnets are also used. Growing concern for the lifetime of APS insertion devices, as well as the permanent magnets that will be used in next-generation, high-power light sources, like the FEL [10,11], resulted from the partial demagnetization observations made at both facilities. This concern in relation to radiation-induced demagnetization spurred a long-term project to measure and analyze the absorbed doses received by the APS insertion devices. The project required a reliable photon high-dose dosimetry technique capable of measuring absorbed doses greater than 10 6 rad, which was not readily available at the APS. Through a collaboration with the National Institute of Standards and Technology (NIST), one such technique using radiachromic films was considered, tested, and calibrated at the APS. This consequently led to the implementation of radiachromic film dosimetry for measuring the absorbed doses received by the insertion devices for each of the APS runs

  6. Transport measurements on selective area grown Te-based topological insulator thin films

    Energy Technology Data Exchange (ETDEWEB)

    Weyrich, Christian; Schall, Melissa; Kampmeier, Joern; Lanius, Martin; Mussler, Gregor; Schaepers, Thomas; Gruetzmacher, Detlev [Peter Gruenberg Institute (PGI- 9) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Virtual Institute for Topological Insulators (VITI), Forschungszentrum Juelich GmbH, 52425 Juelich (Germany)

    2015-07-01

    We present magnetotransport measurements on Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} thin films, grown on prepatterned structures atop silicon-on-insulator substrates by molecular beam epitaxy. The substrates contain Si mesa fabricated from the 70nm thick Si(111) top layer on a 300nm thick SiO{sub 2} buried oxide layer. Therefore, we were able to utilize the difference in surface configuration between the Si(111) and the amorphous SiO{sub 2}, since only the hexagonal silicon surface supports growth of the tellurides. Using transport we show that films of comparable or even higher quality can be achieved using this method which furthermore evades the need of any additionally ex-situ patterning of the layers. With this, we pave the road to a simple fabrication method for nanometer sized structures that circumvents common problems of conventional methods like ion etching including hardened remains of photo resist and the like.

  7. An easy way to measure accurately the direct magnetoelectric voltage coefficient of thin film devices

    Science.gov (United States)

    Poullain, Gilles; More-Chevalier, Joris; Cibert, Christophe; Bouregba, Rachid

    2017-01-01

    TbxDy1-xFe2/Pt/Pb(Zrx, Ti1-x)O3 thin films were grown on Pt/TiO2/SiO2/Si substrate by multi-target sputtering. The magnetoelectric voltage coefficient αΗΜΕ was determined at room temperature using a lock-in amplifier. By adding, in series in the circuit, a capacitor of the same value as that of the device under test, we were able to demonstrate that the magnetoelectric device behaves as a voltage source. Furthermore, a simple way to subtract the stray voltage arising from the flow of eddy currents in the measurement set-up, is proposed. This allows the easy and accurate determination of the true magnetoelectric voltage coefficient. A large αΗΜΕ of 8.3 V/cm. Oe was thus obtained for a Terfenol-D/Pt/PZT thin film device, without DC magnetic field nor mechanical resonance.

  8. Fuel cell measurements with cathode catalysts of sputtered Pt3Y thin films.

    Science.gov (United States)

    Lindahl, Niklas; Eriksson, Björn; Grönbeck, Henrik; Wreland Lindström, Rakel; Lindbergh, Göran; Lagergren, Carina; Wickman, Björn

    2018-03-07

    Fuel cells are foreseen to have an important role in sustainable energy systems, provided that catalysts with higher activity and stability are developed. In this work, we deposit highly active sputtered thin films of platinum alloyed with yttrium (Pt3Y) on commercial gas diffusion layers and measure their performance in a proton exchange membrane fuel cell. After acid pretreatment, the alloy is found to have up to 2.5 times higher specific activity than pure platinum. The performance of Pt3Y is much higher than pure Pt, even if all of the alloying element was leached out from parts of the thin metal film on the porous support. This indicates that an even higher performance is expected if the structure of the Pt3Y catalyst or of the support could be further improved. The results show that platinum alloyed with rare earth metals can be used as highly active cathode catalyst material, and significantly reduce the amount of platinum needed, in real fuel cells. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Optical constants of CH3NH3PbBr3 perovskite thin films measured by spectroscopic ellipsometry

    KAUST Repository

    Alias, Mohd Sharizal

    2016-07-14

    The lack of optical constants information for hybrid perovskite of CH3NH3PbBr3 in thin films form can delay the progress of efficient LED or laser demonstration. Here, we report on the optical constants (complex refractive index and dielectric function) of CH3NH3PbBr3 perovskite thin films using spectroscopic ellipsometry. Due to the existence of voids, the refractive index of the thin films is around 8% less than the single crystals counterpart. The energy bandgap is around 2.309 eV as obtained from photoluminescence and spectrophotometry spectra, and calculated from the SE analysis. The precise measurement of optical constants will be useful in designing optical devices using CH3NH3PbBr3 thin films.

  10. Development of a Handmade Conductivity Measurement Device for a Thin-Film Semiconductor and Its Application to Polypyrrole

    Science.gov (United States)

    Seng, Set; Shinpei, Tomita; Yoshihiko, Inada; Masakazu, Kita

    2014-01-01

    The precise measurement of conductivity of a semiconductor film such as polypyrrole (Ppy) should be carried out by the four-point probe method; however, this is difficult for classroom application. This article describes the development of a new, convenient, handmade conductivity device from inexpensive materials that can measure the conductivity…

  11. Characterizing the discoloration of EBT3 films in solar UV A+B measurement using red LED

    Science.gov (United States)

    Omar, Ahmad Fairuz; Osman, Ummi Shuhada; Tan, Kok Chooi

    2017-09-01

    This research article proposes an alternative method to measure the discoloration or the color changes of EBT3 films due to exposure by solar ultraviolet (UV A+B) dose. Common methods to measure the color changes of EBT3 are through imaging technique measured by flatbed scanner and through absorbance spectroscopy measured by visible spectrometer. The research presented in this article measure the color changes of EBT3 through simplified optical system using the combination of light emitting diode (LED) as the light source and photodiode as the detector. In this research, 50 pieces of Gafchromic EBT3 films were prepared with the dimension of 3 cm x 2 cm. Color of the films changed from light green to dark green based on the total accumulated UV dose (mJ/cm2) by each film that depends on the duration of exposure, irradiance level (mW/cm2) and condition of the sky. The exposed films were then taken to the laboratory for its color measurement using absorbance spectroscopy technique and using newly developed simplified optical instrument using LED-photodiode. Results from spectroscopy technique indicate that wavelength within red region exhibit better response in term of linearity and responsivity towards the colors of EBT3 films. Wavelength of 626 nm was then selected as the peak emission wavelength for LED-photodiode absorbance system. UV dose measurement using LEDphotodiode system produced good result with coefficient of determination, R2 of 0.97 and root mean square of error, RMSE of 431.82 mJ/cm2 while comparatively, similar wavelength but analyzed from spectroscopy dataset produced R2 of 0.988 and RMSE of 268.94 mJ/cm2.

  12. Characterization of positional errors and their influence on micro four-point probe measurements on a 100 nm Ru film

    DEFF Research Database (Denmark)

    Kjær, Daniel; Hansen, Ole; Østerberg, Frederik Westergaard

    2015-01-01

    Thin-film sheet resistance measurements at high spatial resolution and on small pads are important and can be realized with micrometer-scale four-point probes. As a result of the small scale the measurements are affected by electrode position errors. We have characterized the electrode position...... errors in measurements on Ru thin film using an Au-coated 12-point probe. We show that the standard deviation of the static electrode position error is on the order of 5 nm, which significantly affects the results of single configuration measurements. Position-error-corrected dual......-configuration measurements, however, are shown to eliminate the effect of position errors to a level limited either by electrical measurement noise or dynamic position errors. We show that the probe contact points remain almost static on the surface during the measurements (measured on an atomic scale) with a standard...

  13. Advocacy Coalition for Safer Sex in the Adult Film Industry: The Case of Los Angeles County's Measure B.

    Science.gov (United States)

    Cohen, Adam Carl; Tavrow, Paula; McGrath, Mark Roy

    2017-06-01

    Performers in the adult film industry are routinely exposed to bloodborne pathogens. In 2012, public health advocates in Los Angeles County convinced voters to pass a ballot initiative-Measure B-to mandate condom use on adult film sets. This article presents a case study of the advocacy coalition's strategies used to achieve greater workplace safety using the advocacy coalition framework. The authors were given access to all memoranda, market research, and campaign tools used to promote Measure B. To reconstruct adult film industry counterefforts, the authors reviewed trade publications, social media, and blog posts. When legislative efforts failed, advocates engaged in a step-by-step strategy built around voters to achieve passage of a ballot initiative mandating condom use for all adult films produced in Los Angeles County. Although the industry immediately filed a lawsuit after passage of Measure B, its constitutionality has been upheld. Measure B passed because public health advocates were able to assemble scientific evidence, build public support, counter false claims, and maintain consistent messages throughout the campaign. The adult film industry lacked social capital, cohesion, and nimbleness. To bolster regulatory efforts, appealing to voters to favor safe workplaces may be an effective advocacy strategy for other industries.

  14. Critical electrode size in measurement of d33 coefficient of films via spatial distribution of piezoelectric displacement

    International Nuclear Information System (INIS)

    Wang Zhihong; Miao Jianmin

    2008-01-01

    Spatial distributions of piezoelectric displacement response across the top electrode have been used in this paper to measure the piezoelectric coefficient d 33 of films based on the converse piezoelectric effect. The technical details and features of a scanning laser Doppler vibrometer have been summarized and discussed for accurately obtaining the spatial displacement distributions. Three definitions, including the apparent, the effective and the constrained piezoelectric coefficient d 33 of films, have been clarified and used to better understand the fundamental phenomenon behind the measured displacement distributions. Finite element analysis reveals that both the apparent and the effective piezoelectric coefficients depend on the electrode radius of test capacitor as well as film thickness. However, there exists a critical electrode size for apparent piezoelectric coefficients and a critical test capacitor aspect ratio for effective piezoelectric coefficient. Beyond their respective critical values, both coefficients converge to the constrained piezoelectric coefficient irrespective of film thickness. The finding of the critical electric size makes it possible to consistently measure the constrained piezoelectric coefficient of films by using the spatial distributions of the piezoelectric displacement response and becomes the fundamental criterion of this measurement method

  15. Atomic force microscopy measurements of topography and friction on dotriacontane films adsorbed on a SiO2 surface

    DEFF Research Database (Denmark)

    Trogisch, S.; Simpson, M.J.; Taub, H.

    2005-01-01

    We report comprehensive atomic force microscopy (AFM) measurements at room temperature of the nanoscale topography and lateral friction on the surface of thin solid films of an intermediate-length normal alkane, dotriacontane (n-C32H66), adsorbed onto a SiO2 surface. Our topographic and frictional...... their location. Above a minimum size, the bulk particles are separated from islands of perpendicularly oriented molecules by regions of exposed parallel layers that most likely extend underneath the particles. We find that the lateral friction is sensitive to the molecular orientation in the underlying...... crystalline film and can be used effectively with topographic measurements to resolve uncertainties in the film structure. We measure the same lateral friction on top of the bulk particles as on the perpendicular layers, a value that is about 2.5 times smaller than on a parallel layer. Scans on top...

  16. First Beam Test of Nanometer Spot Size Monitor Using Laser Interferometry

    CERN Document Server

    Walz, D

    2003-01-01

    The nanometer spot size monitor based on the laser interferometry (Laser-Compton Spot Size Monitor) has been tested in FFTB beam line at SLAC. A low emittance beam of 46 GeV electrons, provided by the two-mile linear accelerator, was focused into nanometer spot in the FFTB line, and its transverse dimensions were precisely measured by the spot size monitor.

  17. Cotton-wool spots.

    Science.gov (United States)

    Brown, G C; Brown, M M; Hiller, T; Fischer, D; Benson, W E; Magargal, L E

    1985-01-01

    A series of 24 consecutive patients presenting with a fundus picture characterized by a predominance of cotton-wool spots, or a single cotton-wool spot, is reported. Excluded were patients with known diabetes mellitus. Etiologic conditions found included previously undiagnosed diabetes mellitus in five patients, systemic hypertension in five patients, cardiac valvular disease in two patients, radiation retinopathy in two patients, and severe carotid artery obstruction in two patients. Dermatomyositis, systemic lupus erythematosus, polyarteritis nodosa, leukemia, AIDS, Purtscher's retinopathy, metastatic carcinoma, intravenous drug abuse, partial central retinal artery obstruction, and giant cell arteritis were each found in one patient. In only one patient did a systemic workup fail to reveal an underlying cause. The presence of even one cotton-wool spot in an otherwise normal fundus necessitates an investigation to ascertain systemic etiologic factors.

  18. Measurements of nanoscale domain wall flexing in a ferromagnetic thin film.

    Science.gov (United States)

    Balk, A L; Nowakowski, M E; Wilson, M J; Rench, D W; Schiffer, P; Awschalom, D D; Samarth, N

    2011-08-12

    We use the high spatial sensitivity of the anomalous Hall effect in the ferromagnetic semiconductor Ga(1-x)Mn(x)As, combined with the magneto-optical Kerr effect, to probe the nanoscale elastic flexing behavior of a single magnetic domain wall in a ferromagnetic thin film. Our technique allows position sensitive characterization of the pinning site density, which we estimate to be ∼10(14) cm(-3). Analysis of single site depinning events and their temperature dependence yields estimates of pinning site forces (10 pN range) as well as the thermal deactivation energy. Our data provide evidence for a much higher intrinsic domain wall mobility for flexing than previously observed in optically probed μm scale measurements.

  19. Large carbon cluster thin film gauges for measuring aerodynamic heat transfer rates in hypersonic shock tunnels

    International Nuclear Information System (INIS)

    Srinath, S; Reddy, K P J

    2015-01-01

    Different types of Large Carbon Cluster (LCC) layers are synthesized by a single-step pyrolysis technique at various ratios of precursor mixture. The aim is to develop a fast responsive and stable thermal gauge based on a LCC layer which has relatively good electrical conduction in order to use it in the hypersonic flow field. The thermoelectric property of the LCC layer has been studied. It is found that these carbon clusters are sensitive to temperature changes. Therefore suitable thermal gauges were developed for blunt cone bodies and were tested in hypersonic shock tunnels at a flow Mach number of 6.8 to measure aerodynamic heating. The LCC layer of this thermal gauge encounters high shear forces and a hostile environment for test duration in the range of a millisecond. The results are favorable to use large carbon clusters as a better sensor than a conventional platinum thin film gauge in view of fast responsiveness and stability. (paper)

  20. Kelvin Probe Measurements on Solar Cells and Other Thin Film Devices

    Science.gov (United States)

    Delk, John; Dils, D. W.; Lush, G. B.; Mackey, Willie R. (Technical Monitor)

    2001-01-01

    The Kelvin Probe (KP) has been used for years to measure the surface potential of metals and semiconductors. The KP is an elegantly simple but powerful tool invented by Lord Kelvin around the turn of the century. Using changes in surface potentials as a result of changing the intensity and wavelength of illumination, the KP returns data on material parameters such as band gap energies and the energy levels of interface states. We have employed the KP in the study of CdTe-based solar cells and quantum dot-based solar cells, as well as other thin-film devices. We hope eventually that the KP will be used as an in-line testing station for a fabrication process so that unfinished devices that will not meet requirements can be thrown out before the processing is completed, thus saving resources. Results of these studies will be presented.

  1. Measurement of thickness of thin films by the X-ray diffraction method

    International Nuclear Information System (INIS)

    Srinivasan, C.; Balasingh, C.; Singh, A.K.

    1979-07-01

    X-ray diffraction method can be used to measure the thickness of thin films (coatings). The principle and the experimental details of the x-ray diffraction methods are described. The intensities of the diffracted beams are derived assuming a random orientation of the crystallites in the diffracting medium. Consequently, the expressions are not valid when the sample has preferred orientation. To check the performance of the method, thicknesses of nickel deposits on mild steel plates were determined by the x-ray diffraction method and the results compared with those obtained by the weighing method and metallographic examination. The weighing method which gives an accuracy of +- 0.1 micron is taken as the standard. The x-ray diffraction methods and the metallographic examinations give values within +- 1 micron of the value obtained by the weighing method. (author)

  2. Direct and Indirect Polymer-Polymer Interfacial Slip Measurements in Multilayered Films

    Science.gov (United States)

    Lee, Patrick C.; Park, Hee Eon; Macosko, Christopher W.

    2008-07-01

    Significant slip can occur during flow of two immiscible polymers due to reduced entanglements at their interface. The slip is of practical importance because of its effect on morphology and adhesion of these multi-phase materials, such as disordered two-phase blends and multilayer films. In this research, we are investigating the amount of polymer-polymer slip over a range of shear stresses from rheological measurements (i.e., indirect method) and visualization measurements (i.e., direct method) on co-extruded multilayer films. Two types of alternately layered blends were chosen: polypropylene (PP)/polystyrene (PS) and polyethylene (PE)/fluoropolymer (FP) blends. The multilayer samples of both PP/PS and PE/FP blends were prepared in a co-extrusion setup (Zhao and Macosko J. Rheol. 2002) at 200 and 210 °C, respectively, in order to match viscosity and linear viscoelasticity. To study the polymer-polymer interfacial slip over a wide stress range, three types of rheometers were used: an in-line slit-die rheometer, a rotational parallel-disk rheometer, and a sliding-plates rheometer (SPR). It was observed that the viscosity of a multilayer sample is lower than the harmonic average viscosity of two neat polymers for both PP/PS and PE/FP and decreases with the number of layers above a certain critical shear stress. Two visualization techniques, (i) the SPR with a glass top plate and (ii) a high temperature shearing cell, were utilized to prove the slip. The slip velocity (i.e., the amount of macroscopic velocity discontinuity at the interface) with respect to shear stress was calculated from each rheological and visualization methods and compared.

  3. Effect of Hysteresis on Measurements of Thin-Film Cell Performance

    Energy Technology Data Exchange (ETDEWEB)

    Albin, D.; del Cueto, J.

    2011-03-01

    Transient or hysteresis effects in polycrystalline thin film CdS/CdTe cells are a function of pre-measurement voltage bias and whether Cu is introduced as an intentional dopant during back contact fabrication. When Cu is added, the current-density (J) vs. voltage (V) measurements performed in a reverse-to-forward voltage direction will yield higher open-circuit voltage (Voc), up to 10 mV, and smaller short-circuit current density (Jsc), by up to 2 mA/cm2, relative to scanning voltage in a forward-to-reverse direction. The variation at the maximum power point, Pmax, is however small. The resulting variation in FF can be as large as 3%. When Cu is not added, hysteresis in both Voc and Jsc is negligible however Pmax hysteresis is considerably greater. This behavior corroborates observed changes in depletion width, Wd, derived from capacitance (C) vs voltage (V) scans. Measured values of Wd are always smaller in reverse-to-forward voltage scans, and conversely, larger in the forward-to-reverse voltage direction. Transient ion drift (TID) measurements performed on Cu-containing cells do not show ionic behavior suggesting that capacitance transients are more likely due to electronic capture-emission processes. J-V curve simulation using Pspice shows that increased transient capacitance during light-soak stress at 100 degrees C correlates with increased space-charge recombination. Voltage-dependent collection however was not observed to increase with stress in these cells.

  4. Measurement of central corneal thickness and pre-corneal tear film thickness of rabbits using the Scheimpflug system

    Directory of Open Access Journals (Sweden)

    Jing Dong

    2013-10-01

    Full Text Available AIM:To measure central corneal thickness (CCT and pre-corneal tear film thickness using the Galilei dual-Scheimpflug analyzer (GSA in New Zealand white rabbits.METHODS:Ten normal New Zealand white rabbits (20 eyes were included in this study. With the assistance of 0.1% fluorescein, the pre-corneal tear film can be well visualized. Both eyes of each rabbit were scanned once with the GSA pre- and post-instillation of 1μL 0.1% fluorescein. The difference between the two measurements of CCT (4-mm diameter was recorded as the pachymetric values of the central tear film.RESULTS:The CCT of pre- and post-instillation was 388.8±9.5μm and 407.0±10.5μm, respectively. After a paired t-test analysis, the central pre-corneal tear film thickness of 4mm diameter was 18.2±5.31μm with a 95% confidence interval of (15.7, 20.6μm (PCONCLUSION:GSA can be used to measure CCT and analyze central tear film thickness of rabbits with the help of fluorescein.

  5. Development of a sensitive experimental set-up for LIF fuel wall film measurements in a pressure vessel

    Science.gov (United States)

    Schulz, Florian; Schmidt, Jürgen; Beyrau, Frank

    2015-05-01

    This paper focusses on fundamental investigations of fuel wall films, which are formed when the spray impinges on the piston or cylinder walls. To reproduce the wide range of operating conditions within homogeneously charged gasoline direct-injection engines, it is necessary to use a film thickness measurement method, which can be applied inside a high-pressure, high-temperature vessel. Hence, we developed a method based on laser-induced fluorescence that reaches: a precision better than 1 µm, a geometric resolution of 31 µm and a practical applicability for wall film thicknesses smaller 80 µm. To obtain accurate film thickness results, we provide a detailed description of the selection of the surrogate fuel isooctane with 3-pentanone as fluorescence tracer and the resulting assembly of the excitation source, beam expander, filters, camera and the essential image processing. Furthermore, advantages and disadvantages of other possible solutions are discussed. Earlier publications provide only little information about the accuracy of their calibration and measurement procedures. Therefore, we tested and compared three basic calibration methods to each other and provide an analysis of possible errors, such as the influence of the preferential evaporation of 3-pentanone. Finally, images of resulting wall films are presented, and practical considerations for the execution of the measurements like recording timings are discussed.

  6. Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Molon, Rafael Scaf; Morais Camillo, Juliana Aparecida Najarro Dearo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara [Araraquara Dental School, Universidade Estadual Paulista, Sao Paulo (Brazil); Sakakura, Celso Eduardo [Barretos Dental School, Barretos Educational Fundation, Sao Paulo (Brazil)

    2012-09-15

    This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC{sub 95%}:6.04-6.54) and 6.79 mm (IC{sub 95%}:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64 mm(IC{sub 95%}:6.40-6.89) and 6.79 mm(IC{sub 95%}:6.45-7.11), respectively. The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

  7. Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

    International Nuclear Information System (INIS)

    Molon, Rafael Scaf; Morais Camillo, Juliana Aparecida Najarro Dearo; Ferreira, Mauricio Goncalves; Loffredo, Leonor Castro Monteiro; Scaf, Gulnara; Sakakura, Celso Eduardo

    2012-01-01

    This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth. Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison. There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC 95% :6.04-6.54) and 6.79 mm (IC 95% :6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64 mm(IC 95% :6.40-6.89) and 6.79 mm(IC 95% :6.45-7.11), respectively. The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

  8. A new application of digital image processing to investigate thin compressed films: The measurement of buckling propagation

    Science.gov (United States)

    Wang, S. B.; Fang, Y. Z.; Jia, H. K.; Li, L. A.; Wang, Z. Y.; Zhang, S. J.

    2010-11-01

    Thin films are used increasingly in technological applications involving microelectromechanical systems, optical reflectors, filters, dielectric stacks, and lithographic resists. However, although the mechanical properties of these submicrometer-thick films are paramount for their effective utilization, many issues remain unresolved to date on the measurement of such properties in thin-film systems. In this paper, an electromechanical device is designed to study the mechanical properties and stability of thin films using two piezoelectric translators. The buckling propagation of thin compressed titanium films deposited on organic glass substrates is investigated utilizing an optical microscope. The rigid-body displacement of the observation field, which is caused by external uniaxial compressive loading, is calculated by the digital image correlation method. Edge detection and filter are carried out to obtain binary images in which the edges of the buckle are obvious, and false noise is eliminated. Therefore, a series of binary images obtained under different loads contains the information on buckling propagation. Further, rigid-body displacement could be compensated for digitally, and the propagation of buckles could be singled out. The experimental results confirm the theoretical proposition that "subcritical" defects can be used to indicate the rigid-body displacement of a substrate. The same method can be used to investigate other problems associated with film buckling.

  9. Potential benefits of dosimetric VMAT tracking verified with 3D film measurements

    Energy Technology Data Exchange (ETDEWEB)

    Crijns, Wouter, E-mail: wouter.crijns@uzleuven.be; Depuydt, Tom; Haustermans, Karin [Laboratory of Experimental Radiotherapy, KU Leuven Department of Oncology, Herestraat 49, 3000 Leuven (Belgium); Radiation Oncology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); Defraene, Gilles [Laboratory of Experimental Radiotherapy, KU Leuven Department of Oncology, Herestraat 49, 3000 Leuven, Belgium and KU Leuven Medical Imaging Research Center, Herestraat 49, 3000 Leuven (Belgium); Van Herck, Hans [KU Leuven Medical Imaging Research Center, Herestraat 49, 3000 Leuven, Belgium and KU Leuven Department of Electrical Engineering (ESAT)–PSI, Center for Processing Speech and Images, 3000 Leuven (Belgium); Maes, Frederik [KU Leuven Medical Imaging Research Center, Herestraat 49, 3000 Leuven (Belgium); KU Leuven Department of Electrical Engineering (ESAT)–PSI, Center for Processing Speech and Images, 3000 Leuven (Belgium); Medical IT Department, KU Leuven iMinds, 3000 Leuven (Belgium); Van den Heuvel, Frank [Department of Oncology, MRC-CR-UK Gray Institute of Radiation Oncology and Biology, University of Oxford, Oxford OX1 2JD (United Kingdom)

    2016-05-15

    Purpose: To evaluate three different plan adaptation strategies using 3D film-stack dose measurements of both focal boost and hypofractionated prostate VMAT treatments. The adaptation strategies (a couch shift, geometric tracking, and dosimetric tracking) were applied for three realistic intrafraction prostate motions. Methods: A focal boost (35 × 2.2 and 35 × 2.7 Gy) and a hypofractionated (5 × 7.25 Gy) prostate VMAT plan were created for a heterogeneous phantom that allows for internal prostate motion. For these plans geometric tracking and dosimetric tracking were evaluated by ionization chamber (IC) point dose measurements (zero-D) and measurements using a stack of EBT3 films (3D). The geometric tracking applied translations, rotations, and scaling of the MLC aperture in response to realistic prostate motions. The dosimetric tracking additionally corrected the monitor units to resolve variations due to difference in depth, tissue heterogeneity, and MLC-aperture. The tracking was based on the positions of four fiducial points only. The film measurements were compared to the gold standard (i.e., IC measurements) and the planned dose distribution. Additionally, the 3D measurements were converted to dose volume histograms, tumor control probability, and normal tissue complication probability parameters (DVH/TCP/NTCP) as a direct estimate of clinical relevance of the proposed tracking. Results: Compared to the planned dose distribution, measurements without prostate motion and tracking showed already a reduced homogeneity of the dose distribution. Adding prostate motion further blurs the DVHs for all treatment approaches. The clinical practice (no tracking) delivered the dose distribution inside the PTV but off target (CTV), resulting in boost dose errors up to 10%. The geometric and dosimetric tracking corrected the dose distribution’s position. Moreover, the dosimetric tracking could achieve the planned boost DVH, but not the DVH of the more homogeneously

  10. A Study of the Electrotransport in Thin Films: An Advanced Method for the Study of Electrotransport in Thin Films Using Electrical Resistance Measurements

    Science.gov (United States)

    Hummel, R. E.; Slippy, W. A., Jr.

    1970-01-01

    To date, very little is understood about electrotransport in thin films. One reason for this is the lack of methods in which electromigration can be adequately monitored dynamically. In this thesis, a new nondestructive method for the study of the electrotransport phenomenon in thin aluminum films is presented. This method makes use of electrical resistance measurements of various regions along the test sample to monitor changes in resistance resulting from electromigration. The advantage of this method is that resistance changes can be observed long before void formation can be seen using standard microscopy methods. In order to achieve the best efficiency using this method, special consideration must be given to the design of the sample. Design problems and their respective solutions are given. The results of the electrical resistance measurements are interpreted by means of photographs taken with an scanning electron microscope. The increase in resistance of the aluminum samples is interpreted to be due to void formation. The expected decrease in resistance near the anode was never observed. It is shown that mass accumulation takes on the form of hillocks and whiskers on the surface of the aluminum film, which does not contribute appreciably to conductivity.

  11. Time Resolved X-Ray Spot Size Diagnostic

    CERN Document Server

    Richardson, Roger; Falabella, Steven; Guethlein, Gary; Raymond, Brett; Weir, John

    2005-01-01

    A diagnostic was developed for the determination of temporal history of an X-ray spot. A pair of thin (0.5 mm) slits image the x-ray spot to a fast scintillator which is coupled to a fast detector, thus sampling a slice of the X-Ray spot. Two other scintillator/detectors are used to determine the position of the spot and total forward dose. The slit signal is normalized to the dose and the resulting signal is analyzed to get the spot size. The position information is used to compensate for small changes due to spot motion and misalignment. The time resolution of the diagnostic is about 1 ns and measures spots from 0.5 mm to over 3 mm. The theory and equations used to calculate spot size and position are presented, as well as data. The calculations assume a symmetric, Gaussian spot. The spot data is generated by the ETA II accelerator, a 2kA, 5.5 MeV, 60ns electron beam focused on a Tantalum target. The spot generated is typically about 1 mm FWHM. Comparisons are made to an X-ray pinhole camera which images th...

  12. Comparison of human tear film osmolarity measured by electrical impedance and freezing point depression techniques.

    Science.gov (United States)

    Tomlinson, Alan; McCann, Louise C; Pearce, Edward I

    2010-09-01

    Tear hyperosmolarity is diagnostic of dry eye disease (DED), yet difficulty in measurement has limited its utility; development of new instruments could facilitate its clinical application. This study compares the new OcuSense TearLab osmometer (OcuSense, Inc, San Diego, CA), based on electrical impedance "lab-on-a-chip" nanoliter technology, with the freezing point depression Clifton Osmometer (Clifton Technical Physics, Hartford, NY). Thirty-six subjects were recruited: 15 DED (9 women, 6 men age: 41 +/- 16 years) and 21 controls (12 women, 9 men age: 35 +/- 12 years); criteria for DED were noninvasive tear breakup time points fell within the 95% confidence limits, and actual values differed by less than 1%. A cutoff value of >316 mOsm/L, derived from the distribution of osmolarity values, was used to diagnose DED with an effectiveness of 73% sensitivity, 90% specificity, and 85% positive predictive value for the OcuSense and 73% sensitivity, 71% specificity, and 65% positive predictive value for the Clifton in the study samples. Tear film osmolarity measured with the OcuSense TearLab system correlates well with the Clifton Osmometer. The new instrument has the potential to provide clinicians with a readily available clinically applicable measure, which could become the gold standard in DED.

  13. DC electric and photoelectric measurements of CdTe thin films in Schottky-barrier cells

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, S

    2004-06-15

    Measurements of the temperature dependence of ohmic and space-charge-limited (SCL) currents on thin films of polycrystalline particles of cadmium telluride in Schottky-junction cells have been carried out in air ambient. These cells showed rectification where p-CdTe material was flanked between an ohmic contact (Au) and a blocking contact (Al). At low voltages, the dark current in the forward direction which corresponds to negative potential at the Al electrode varies exponentially with voltage. At higher voltages, two distinct regions of ohmic and SCL conduction limited by a discrete trapping level are determined. Traps with a density of 3.85x10{sup 22} m{sup -3} located at 0.58 eV above the valence band edge have been observed. The thickness dependence in the square-law region has been found to confirm the d{sup -3} law. Values of conversion efficiency as high as 11.3% and open-circuit voltage of 0.77 V have been evaluated from the photo-measurements of J-V characteristic at input power density of 100 mW cm{sup -2}. Space-charge concentrations and barrier heights have been estimated from the capacitance-voltage (C-V) measurements both in dark and under constant illumination. The linearity of the C{sup -2}-V dependence is associated with a homogenous distribution of the impurities inside the space-charge region.

  14. Direct measurement of the electron-phonon relaxation rate in thin copper films

    Energy Technology Data Exchange (ETDEWEB)

    Taskinen, L.J.; Karvonen, J.T.; Maasilta, I.J. [NanoScience Center, Department of Physics, P.O. Box 35, FIN-40014 University of Jyvaeskylae (Finland); Kivioja, J.M. [Low Temperature Laboratory, Helsinki University of Technology, P.O. Box 2200, 02015 HUT Helsinki (Finland)

    2004-11-01

    We have used normal metal-insulator-superconductor (NIS) tunnel junction pairs, known as SINIS structures, for ultrasensitive thermometry at sub-Kelvin temperatures. With the help of these thermometers, we have developed an ac-technique to measure the electron-phonon (e-p) scattering rate directly, without any other material or geometry dependent parameters, based on overheating the electron gas. The technique is based on Joule heating the electrons in the frequency range DC-10 MHz, and measuring the electron temperature in DC. Because of the nonlinearity of the electron-phonon coupling with respect to temperature, even the DC response will be affected, when the heating frequency reaches the natural cut-off determined by the e-p scattering rate. Results on thin Cu films show a T{sup 4} behavior for the scattering rate, in agreement with indirect measurement of similar samples and numerical modeling of the non-linear response. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Direct measurement of the electron-phonon relaxation rate in thin metal films

    Science.gov (United States)

    Maasilta, Ilari; Kivioja, Jani

    2005-03-01

    We have used normal metal-insulator-superconductor (NIS) tunnel junctions for ultrasensitive thermometry at sub-Kelvin temperatures. With the help of these thermometers, we have developed an ac-technique to measure the electron-phonon (e-p) scattering rate directly, without any other material or geometry dependent parameters, based on overheating the electron gas. The technique is based on Joule heating the electrons in the frequency range DC-10 MHz, and measuring the electron temperature in DC. Because of the nonlinearity of the electron-phonon coupling with respect to temperature, even the DC response will be affected, when the heating frequency reaches the natural cut-off determined by the e-p scattering rate. Results on thin Cu films show a T^4 behavior for the scattering rate, in agreement with indirect measurement of similar samples and numerical modeling of the non-linear response.ootnotetextL. J. Taskinen, J. M. Kivioja, J. T. Karvonen, and I. J. Maasilta, phys. stat. sol. (c) 1, 2856 (2004). ,ootnotetextJ. T. Karvonen, L. J. Taskinen, I. J. Maasilta, phys. stat. sol. (c) 1, 2799 (2004).

  16. Uncertainty quantification and design-of-experiment in absorption-based aqueous film parameter measurements using Bayesian inference.

    Science.gov (United States)

    Pan, R; Daun, K J; Dreier, T; Schulz, C

    2017-04-10

    Diode laser-based multi-wavelength near-infrared (NIR) absorption in aqueous films is a promising diagnostic for making temporally resolved, simultaneous measurements of film thickness, temperature, and concentration of a solute. Our previous work in aqueous urea solutions aimed at determining simultaneously two of these system parameters, while the third one must be fixed or specified by additional measurements. The current work presents a simultaneous NIR absorption-based multi-parameter measurement of thickness, temperature, and solute concentration coupled with the Bayesian methodology that is used to infer probability densities for the obtained data. The Bayesian analysis is based on a temperature- and concentration-dependent spectral database generated with a Fourier transform infrared spectrometer in the range 5500-8000  cm-1 for water with variable temperature and urea concentration. The concept was first validated with measurements using a calibration cell. Probability densities in the measured parameters were quantified using a Markov chain Monte Carlo algorithm, which were used to derive credibility intervals. As a practical demonstration, the temporal variation of film thickness, urea concentration, and liquid temperature were recorded during evaporation of a liquid film deposited on a transparent heated quartz plate.

  17. Radiochromic film for dosimetric measurements in radiation shielding composites synthesized for applied in radiology procedures of high dose

    Energy Technology Data Exchange (ETDEWEB)

    Fontainha, C. C. P. [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Baptista N, A. T.; Faria, L. O., E-mail: crissia@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Full text: Medical radiology offers great benefit to patients. However, although specifics procedures of high dose, as fluoroscopy, Interventional Radiology, Computed Tomography (CT) make up a small percent of the imaging procedures, they contribute to significantly increase dose to population. The patients may suffer tissue damage. The probability of deterministic effects incidence depends on the type of procedure performed, exposure time, and the amount of applied dose at the irradiated area. Calibrated radiochromic films can identify size and distribution of the radiated fields and measure intensities of doses. Radiochromic films are sensitive for doses ranging from 0.1 to 20 c Gy and they have the same response for X-rays effective energies ranging from 20 to 100 keV. New radiation attenuators materials have been widely investigated resulting in dose reduction entrance skin dose. In this work, Bi{sub 2}O{sub 3} and ZrO{sub 2}:8 % Y{sub 2}O{sub 3} composites were obtained by mixing them with P(VDF-Tr Fe) copolymers matrix from casting method and then characterized by Ftir. Dosimetric measurements were obtained with Xr-Q A2 Gafchromic radiochromic films. In this setup, one radiochromic film is directly exposed to the X-rays beam and another one measures the attenuated beam were exposed to an absorbed dose of 10 mGy of RQR5 beam quality (70 kV X-ray beam). Under the same conditions, irradiated Xr-Q A2 films were stored and scanned measurement in order to obtain a more reliable result. The attenuation factors, evaluated by Xr-Q A2 radiochromic films, indicate that both composites are good candidates for use as patient radiation shielding in high dose medical procedures. (Author)

  18. Pulsed laser deposition of HfO{sub 2} thin films on indium zinc oxide: Band offsets measurements

    Energy Technology Data Exchange (ETDEWEB)

    Craciun, D.; Craciun, V., E-mail: valentin.craciun@inflpr.ro

    2017-04-01

    Highlights: • High quality amorphous IZO and HfO{sub 2} films were obtained by PLD technique. • XPS measurements were used to obtain the valence band alignment in HfO{sub 2}/IZO heterostructure. • A valence band offset (ΔE{sub V}) of 1.75 eV was obtained for the HfO{sub 2}/IZO heterostructure. • A conduction band offset (ΔE{sub C}) of 0.65 eV was estimated for the HfO{sub 2}/IZO heterostructure. - Abstract: One of the most used dielectric films for amorphous indium zinc oxide (IZO) based thin films transistor is HfO{sub 2}. The estimation of the valence band discontinuity (ΔE{sub V}) of HfO{sub 2}/IZO heterostructure grown using the pulsed laser deposition technique, with In/(In + Zn) = 0.79, was obtained from X-ray photoelectron spectroscopy (XPS) measurements. The binding energies of Hf 4d5, Zn 2p3 and In 3d5 core levels and valence band maxima were measured for thick pure films and for a very thin HfO{sub 2} film deposited on a thick IZO film. A value of ΔE{sub V} = 1.75 ± 0.05 eV was estimated for the heterostructure. Taking into account the measured HfO{sub 2} and IZO optical bandgap values of 5.50 eV and 3.10 eV, respectively, a conduction band offset ΔE{sub C} = 0.65 ± 0.05 eV in HfO{sub 2}/IZO heterostructure was then obtained.

  19. Thermal Wave Imaging: Flying SPOT Camera.

    Science.gov (United States)

    Wang, Yiqian

    1993-01-01

    A novel "Flying Spot" infrared camera for nondestructive evaluation (NDE) and nondestructive characterization is presented. The camera scans the focal point of an unmodulated heating laser beam across the sample in a raster. The detector of the camera tracks the heating spot in the same raster, but with a time delay. The detector is thus looking at the "thermal wake" of the heating spot. The time delay between heating and detection is determined by the speed of the laser spot and the distance between it and the detector image. Since this time delay can be made arbitrarily small, the camera is capable of making thermal wave images of phenomena which occur on a very short time scale. In addition, because the heat source is a very small spot, the heat flow is fully three-dimensional. This makes the camera system sensitive to features, like tightly closed vertical cracks, which are invisible to imaging systems which employ full-field heating. A detailed theory which relates the temperature profile around the heating spot to the sample thermal properties is also described. The camera represents a potentially useful tool for measuring thermal diffusivities of materials by means of fitting the recorded temperature profiles to the theoretical curves with the diffusivity as a fitting parameter.

  20. X-ray measurements of the depth dependence of stress in gold films

    International Nuclear Information System (INIS)

    Brennan, S.; Munkholm, A.; Leung, O. S.; Nix, W. D.

    2000-01-01

    X-rays are used to determine the stress as a function of depth for five evaporated gold films of 0.8--2.5 microns thickness. The depth dependence is achieved by varying the incident angle of the x-rays, which effects the penetration depth of the x-rays into the film. The films, which have a different thermal expansion coefficient than the silicon substrate, are strained as a result of thermal cycling after deposition. The authors find essentially no variation with stress as a function of depth for these films

  1. Measurement of quasiparticle transport in aluminum films using tungsten transition-edge sensors

    International Nuclear Information System (INIS)

    Yen, J. J.; Shank, B.; Cabrera, B.; Moffatt, R.; Redl, P.; Young, B. A.; Tortorici, E. C.; Brink, P. L.; Cherry, M.; Tomada, A.; Kreikebaum, J. M.

    2014-01-01

    We report on experimental studies of phonon sensors which utilize quasiparticle diffusion in thin aluminum films connected to tungsten transition-edge-sensors (TESs) operated at 35 mK. We show that basic TES physics and a simple physical model of the overlap region between the W and Al films in our devices enables us to accurately reproduce the experimentally observed pulse shapes from x-rays absorbed in the Al films. We further estimate quasiparticle loss in Al films using a simple diffusion equation approach. These studies allow the design of phonon sensors with improved performance.

  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. Laser induced single spot oxidation of titanium

    Energy Technology Data Exchange (ETDEWEB)

    Jwad, Tahseen, E-mail: taj355@bham.ac.uk; Deng, Sunan; Butt, Haider; Dimov, S.

    2016-11-30

    Highlights: • A new high resolution laser induced oxidation (colouring) method is proposed (single spot oxidation). • The method is applied to control oxide films thicknesses and hence colours on titanium substrates in micro-scale. • The method enable imprinting high resolution coloured image on Ti substrate. • Optical and morphological periodic surface structures are also produced by an array of oxide spots using the proposed method. • Colour coding of two colours into one field is presented. - Abstract: Titanium oxides have a wide range of applications in industry, and they can be formed on pure titanium using different methods. Laser-induced oxidation is one of the most reliable methods due to its controllability and selectivity. Colour marking is one of the main applications of the oxidation process. However, the colourizing process based on laser scanning strategies is limited by the relative large processing area in comparison to the beam size. Single spot oxidation of titanium substrates is proposed in this research in order to increase the resolution of the processed area and also to address the requirements of potential new applications. The method is applied to produce oxide films with different thicknesses and hence colours on titanium substrates. High resolution colour image is imprinted on a sheet of pure titanium by converting its pixels’ colours into laser parameter settings. Optical and morphological periodic surface structures are also produced by an array of oxide spots and then analysed. Two colours have been coded into one field and the dependencies of the reflected colours on incident and azimuthal angles of the light are discussed. The findings are of interest to a range of application areas, as they can be used to imprint optical devices such as diffusers and Fresnel lenses on metallic surfaces as well as for colour marking.

  4. Laser induced single spot oxidation of titanium

    International Nuclear Information System (INIS)

    Jwad, Tahseen; Deng, Sunan; Butt, Haider; Dimov, S.

    2016-01-01

    Highlights: • A new high resolution laser induced oxidation (colouring) method is proposed (single spot oxidation). • The method is applied to control oxide films thicknesses and hence colours on titanium substrates in micro-scale. • The method enable imprinting high resolution coloured image on Ti substrate. • Optical and morphological periodic surface structures are also produced by an array of oxide spots using the proposed method. • Colour coding of two colours into one field is presented. - Abstract: Titanium oxides have a wide range of applications in industry, and they can be formed on pure titanium using different methods. Laser-induced oxidation is one of the most reliable methods due to its controllability and selectivity. Colour marking is one of the main applications of the oxidation process. However, the colourizing process based on laser scanning strategies is limited by the relative large processing area in comparison to the beam size. Single spot oxidation of titanium substrates is proposed in this research in order to increase the resolution of the processed area and also to address the requirements of potential new applications. The method is applied to produce oxide films with different thicknesses and hence colours on titanium substrates. High resolution colour image is imprinted on a sheet of pure titanium by converting its pixels’ colours into laser parameter settings. Optical and morphological periodic surface structures are also produced by an array of oxide spots and then analysed. Two colours have been coded into one field and the dependencies of the reflected colours on incident and azimuthal angles of the light are discussed. The findings are of interest to a range of application areas, as they can be used to imprint optical devices such as diffusers and Fresnel lenses on metallic surfaces as well as for colour marking.

  5. A Novel Instrument and Methodology for the In-Situ Measurement of the Stress in Thin Films

    Science.gov (United States)

    Broadway, David M.; Omokanwaye, Mayowa O.; Ramsey, Brian D.

    2014-01-01

    We introduce a novel methodology for the in-situ measurement of mechanical stress during thin film growth utilizing a highly sensitive non-contact variation of the classic spherometer. By exploiting the known spherical deformation of the substrate the value of the stress induced curvature is inferred by measurement of only one point on the substrate's surface-the sagittal. From the known curvature the stress can be calculated using the well-known Stoney equation. Based on this methodology, a stress sensor has been designed which is simple, highly sensitive, compact, and low cost. As a result of its compact nature, the sensor can be mounted in any orientation to accommodate a given deposition geometry without the need for extensive modification to an already existing deposition system. The technique employs the use of a double side polished substrate that offers good specular reflectivity and is isotropic in its mechanical properties, such as oriented crystalline silicon or amorphous soda lime glass, for example. The measurement of the displacement of the uncoated side during deposition is performed with a high resolution (i.e. 5nm), commercially available, inexpensive, fiber optic sensor which can be used in both high vacuum and high temperature environments (i.e. 10(exp-7) Torr and 480oC, respectively). A key attribute of this instrument lies in its potential to achieve sensitivity that rivals other measurement techniques such as the micro cantilever method but, due to the comparatively larger substrate area, offers a more robust and practical alternative for subsequent measurement of additional characteristics of the film that can might be correlated to film stress. We present measurement results of nickel films deposited by magnetron sputtering which show good qualitative agreement to the know behavior of polycrystalline films previously reported by Hoffman.

  6. Current-Induced Joule Heating and Electrical Field Effects in Low Temperature Measurements on TIPS Pentacene Thin Film Transistors

    NARCIS (Netherlands)

    Nikiforov, G.O.; Venkateshvaran, D.; Mooser, S.; Meneau, A.; Strobel, T.; Kronemeijer, A.; Jiang, L.; Lee, M.J.; Sirringhaus, H.

    2016-01-01

    The channel temperature (Tch) of solution-processed 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS pentacene) thin film transistors (TFTs) is closely monitored in real time during current–voltage (I–V) measurements carried out in a He exchange gas cryostat at various base temperatures (Tb)

  7. Direct Reconstruction of Two-Dimensional Currents in Thin Films from Magnetic-Field Measurements

    Science.gov (United States)

    Meltzer, Alexander Y.; Levin, Eitan; Zeldov, Eli

    2017-12-01

    An accurate determination of microscopic transport and magnetization currents is of central importance for the study of the electric properties of low-dimensional materials and interfaces, of superconducting thin films, and of electronic devices. Current distribution is usually derived from the measurement of the perpendicular component of the magnetic field above the surface of the sample, followed by numerical inversion of the Biot-Savart law. The inversion is commonly obtained by deriving the current stream function g , which is then differentiated in order to obtain the current distribution. However, this two-step procedure requires filtering at each step and, as a result, oversmooths the solution. To avoid this oversmoothing, we develop a direct procedure for inversion of the magnetic field that avoids use of the stream function. This approach provides enhanced accuracy of current reconstruction over a wide range of noise levels. We further introduce a reflection procedure that allows for the reconstruction of currents that cross the boundaries of the measurement window. The effectiveness of our approach is demonstrated by several numerical examples.

  8. Measurements of processes in ruthenium oxide film electrodes with the quartz-crystal microbalance technique

    International Nuclear Information System (INIS)

    Buttry, D.; Gottesfeld, S.

    1987-01-01

    The authors describe the first application of the quartz-crystal microbalance (QCM) technique for monitoring electrochemical processes in oxide film electrodes. They have investigated a film of ruthenium oxide, applied by the thermal decomposition of ruthenium chloride onto one side of the quartz-crystal. The quartz-crystal was precoated with gold keyhole patterns on both sides for inducing the 5 MHz resonance, followed by a thin Ti layer to ensure good adherence of the ruthenium oxide. Ruthenium oxide films are being investigated at Los Alamos for potential use in electrochemical capacitors. The material exhibits large charge capacity per geometric area and fast charge-discharge rates. Different possible processes can be responsible for charge compensation in such oxide materials, including those associated with simple double-layer charging, with pseudocapacitance, and with ion insertion into the small grains of the high-surface-area oxide material. The dynamics of such processes are determined, for a given oxide film, by the nature of the electrolyte and the resulting mechanism of charge-compensation. The QCM technique provides interesting information on these processes, as well as on film hydration and film dissolution process. The authors' initial results are presented in this paper. The results demonstrate the QCM as a sensitive tool for following not only ionic insertion processes during potential modulation, but also processes of film swelling and film dissolution

  9. Measurement of time-dependent adhesion between a polymer film and a flat indenter tip

    International Nuclear Information System (INIS)

    Choi, S T; Lee, S R; Earmme, Y Y

    2008-01-01

    We revisited an elasticity problem of flat indentation on an elastic film bonded to a rigid substrate and obtained the force-depth relation in a simple form. With the obtained force-depth relation, Kendall's elastic equilibrium theory of adhesion was extended to the adhesion between a flat tip and a compressible elastic film. Thus, the thermodynamic work of adhesion at the moment of debonding of a flat tip from an elastic film was expressed in terms of pull-off force, elastic constants and geometric parameters. It is worth noting that the obtained relation for elastic films is still valid for viscoelastic films if viscoelastic losses are limited to the process zone of debonding. This makes it possible to study the time-dependent adhesion of viscoelastic polymer films. Indentation experiments with a flat diamond tip were performed on SU-8 films, and the results verified that the extended form of Kendall's theory correctly compensates the effect of the finite thickness of the films on the work of adhesion. The indentation results also showed that the work of adhesion is strongly dependent on the unloading velocity of the tip, while indentation depth and dwell time have only minor effects on the work of adhesion

  10. Electronic density of state of Mn-N thin films measured by XPS

    CERN Document Server

    Morio, K

    2003-01-01

    Polycrystalline thin films with an oriented direction of epsilon-Mn sub 4 N along the (111) axis and of eta-Mn sub 3 N sub 2 along the (113) axis were prepared as a single phase by RF reactive magnetron sputtering method. A comparison of XPS spectral analysis with discrete Variational-X alpha method showed that the N atoms in Mn-N compounds behave as a donor and govern the magnetic properties of the films. The epsilon-Mn sub 4 N films was a single phase perovskite type crystal with lattice parameter 0.386 nm, and this films had properties of the ferrimagnetism with 1.1 mu sub B per unit cell. The eta-Mn sub 3 N sub 2 films was face center tetragonal (a=0.4205 nm, c=1.2131 nm), and it had properties of antiferromagnetism with 0.4 mu sub B per unit cell. (author)

  11. The measuring technique developed to evaluate the thermal diffusivity of the multi-layered thin film specimens

    Directory of Open Access Journals (Sweden)

    Li Tse-Chang

    2017-01-01

    Full Text Available In the present study, the thermal diffusivities of the Al, Si and ITO films deposited on the SUS304 steel substrate are evaluated via the present technique. Before applying this technique, the temperature for the thin film of the multi-layered specimen is developed theoretically for the one- dimensional steady heat conduction in response to amplitude and frequency of the periodically oscillating temperature imposed by a peltier placed beneath the specimen's substrate. By the thermal-electrical data processing system excluding the lock-in amplifier, the temperature frequency a3 has been proved first to be independent of the electrical voltage applied to the peltier and the contact position of the thermocouples. The experimental data of phase difference for three kinds of specimen are regressed well by a straight line with a slope. Then, the thermal diffusivity of the thin film is thus determined if the slope value and the film- thickness are available. In the present arrangements for the thermocouples, two thermal diffusivity values are quite close each other and valid for every kind of specimen. This technique can provide an efficient, low-cost method for the thermal diffusivity measurements of thin films.

  12. Preparation and measurement of hysteresis curve FeCoNi thin film for the application of electromagnet design

    International Nuclear Information System (INIS)

    Yunanto; Tri Mardji Atmono

    2015-01-01

    The preparation and preceiving nature of hysteresis curve of FeCoNi thin film for application in electromagnet design have been done. The aim of the research is to obtain FeCoNi thin film having high saturation and magnetic permeability, that can be used to design the electromagnet for cyclotron. The desired alloy based on this thin film FeCoNi should produce a magnetic field of 2.4 T by low power supply 3 kW. To get the thin film FeCoNi, it was used the material target Co with Ni and Fe as chip put on the surface of Co, to form a mosaic target, bombarded by Ar-ions + . The result of VSM measurement showed a hysteresis curve having saturation of 0.5 T, higher than that of thin film Ni having 0.2 T. The composition which was analyzed by using EDAX showed 17,2 %, 52,78 %, 19,76 %, 10,26 % content of Fe, Co, Ni and O, respectively. (author)

  13. Measurement of backscatter factor for kilovoltage x-ray beam using ionization chamber and Gafchromic XR-QA2 film

    Science.gov (United States)

    Shukor, N. S. Ab; Asri, N. H. Mohd; Syed Jaafar, S. M. F.; Rosnan, M. S.; Aziz, S. A. Abdul

    2018-01-01

    Backscatter factor (BSF) is an important parameter in the determination of surface dose for kilovoltage X-ray beam. The purpose of this study was to measure the BSF for kilovoltage diagnostic X-ray beam, and compare the measured BSF between Gafchromic XR-QA2 film and shadow free (SFD) ionization chamber (IC). The parameters that may affect the BSF, such as tube voltage (kVp) and field size, were also studied. The results were in good agreement with the TRS 457, with deviation of less than 12 %. Based on the film study, the BSF obtained from the film measurement were found to be lower than that of the IC, with average difference of 26 %. It was also found that smaller field size resulted in lower effective energy, and the amount of photons which scattered back onto the surface were also smaller. This study demonstrated that the Gafchromic XR-QA2 film was not suitable for the application of small field size.

  14. Cooling Effectiveness Measurements for Air Film Cooling of Thermal Barrier Coated Surfaces in a Burner Rig Environment Using Phosphor Thermometry

    Science.gov (United States)

    Eldridge, Jeffrey I.; Shyam, Vikram; Wroblewski, Adam C.; Zhu, Dongming; Cuy, Michael D.; Wolfe, Douglas E.

    2016-01-01

    While the effects of thermal barrier coating (TBC) thermal protection and air film cooling effectiveness are usually studied separately, their contributions to combined cooling effectiveness are interdependent and are not simply additive. Therefore, combined cooling effectiveness must be measured to achieve an optimum balance between TBC thermal protection and air film cooling. In this investigation, surface temperature mapping was performed using recently developed Cr-doped GdAlO3 phosphor thermometry. Measurements were performed in the NASA GRC Mach 0.3 burner rig on a TBC-coated plate using a scaled up cooling hole geometry where both the mainstream hot gas temperature and the blowing ratio were varied. Procedures for surface temperature and cooling effectiveness mapping of the air film-cooled TBC-coated surface are described. Applications are also shown for an engine component in both the burner rig test environment as well as an engine afterburner environment. The effects of thermal background radiation and flame chemiluminescence on the measurements are investigated, and advantages of this method over infrared thermography as well as the limitations of this method for studying air film cooling are discussed.

  15. ESA uncovers Geminga's `hot spot'

    Science.gov (United States)

    2004-07-01

    whether Geminga’s tails are formed by electrons or by their twin particles with an opposite electrical charge, called positrons. Nevertheless, they expected that, if for instance electrons are kicked into space, then the positrons should be funnelled down towards the neutron star itself, like in an ‘own goal’. Where these particles strike the surface of the star, they ought to create a hot spot, a region considerably hotter than the surroundings. An international team of astronomers, lead by Patrizia Caraveo, IASF-CNR, Italy, has now reported the detection of such a hot spot on Geminga using ESA’s XMM-Newton observatory. With a temperature of about two million degrees, this hot spot is considerably hotter than the one half million degrees of the surrounding surface. According to this new work, Geminga’s hot spot is just 60 metres in radius. "This hot spot is the size of a football field," said Caraveo, "and is the smallest object ever detected outside of our Solar System." Details of this size can presently be measured only on the Moon and Mars and, even then, only from a spacecraft in orbit around them. The presence of a hot spot was suspected in the late 1990s but only now can we see it ‘live’, emitting X-rays as Geminga rotates, thanks to the superior sensitivity of ESA’s X-ray observatory, XMM-Newton. The team used the European Photon Imaging Cameras (EPIC) to conduct a study of Geminga, lasting about 28 consecutive hours and recording the arrival time and energy of every X-ray photon that Geminga emitted within XMM-Newton’s grasp. "In total, this amounted to 76 850 X-ray counts - twice as many as have been collected by all previous observations of Geminga, since the time of the Roman Empire," said Caraveo. Knowing the rotation rate of Geminga and the time of each photon’s arrival meant that astronomers could identify which photons were coming from each region of the neutron star as it rotates. When they compared photons coming from different

  16. Spotting Stellar Activity Cycles in Gaia Astrometry

    Science.gov (United States)

    Morris, Brett M.; Agol, Eric; Davenport, James R. A.; Hawley, Suzanne L.

    2018-03-01

    Astrometry from Gaia will measure the positions of stellar photometric centroids to unprecedented precision. We show that the precision of Gaia astrometry is sufficient to detect starspot-induced centroid jitter for nearby stars in the Tycho-Gaia Astrometric Solution (TGAS) sample with magnetic activity similar to the young G-star KIC 7174505 or the active M4 dwarf GJ 1243, but is insufficient to measure centroid jitter for stars with Sun-like spot distributions. We simulate Gaia observations of stars with 10 year activity cycles to search for evidence of activity cycles, and find that Gaia astrometry alone likely can not detect activity cycles for stars in the TGAS sample, even if they have spot distributions like KIC 7174505. We review the activity of the nearby low-mass stars in the TGAS sample for which we anticipate significant detections of spot-induced jitter.

  17. Experimental measurement of the dynamic pressure distribution in a squeeze film bearing damper executing circular centered orbits

    Science.gov (United States)

    Sanandres, L. A.; Vance, J. M.

    1987-01-01

    A review of previous experimental measurements of squeeze film damper (SFD) forces is given. Measurements by the authors of SFD pressure fields and force coefficients, for circular centered orbits with epsilon = 0.5, are described and compared with computer predictions. For Reynolds numbers over the range 2-6, the effect of fluid inertia on the pressure fields and forces is found to be significant.

  18. TWO-DIMENSIONAL MAGNETISM IN LANGMUIR-BLODGETT FILMS OF MANGANESE STEARATE MEASURED IN A He3-SQUID MAGNETOMETER

    OpenAIRE

    Head, D.; Blott, B.; Melville, D.

    1988-01-01

    The magnetisation of manganese stearate layers on aluminium foil has been measured between 20 K and 0.4 K. With the applied magnetic field parallel to the film we deduced an equivalent susceptibility of 6.4 x 10-3 4.2 K. This is close to our paramagnetic calculation based on the measured manganese spacing. Our results would be consistent with a transition to antiferromagnetism below 0.4 K.

  19. Chocolate spot of Eucalyptus

    OpenAIRE

    Cheewangkoon, R.; Groenewald, J.Z.; Hyde, K.D.; To-anun, C.; Crous, P.W.

    2012-01-01

    Chocolate Spot leaf disease of Eucalyptus is associated with several Heteroconium-like species of hyphomycetes that resemble Heteroconium s.str. in morphology. They differ, however, in their ecology, with the former being plant pathogenic, while Heteroconium s.str. is a genus of sooty moulds. Results of molecular analyses, inferred from DNA sequences of the large subunit (LSU) and internal transcribed spacers (ITS) region of nrDNA, delineated four Heteroconium-like species on Eucalyptus, name...

  20. The fractal nature of vacuum arc cathode spots

    International Nuclear Information System (INIS)

    Anders, Andre

    2005-01-01

    Cathode spot phenomena show many features of fractals, for example self-similar patterns in the emitted light and arc erosion traces. Although there have been hints on the fractal nature of cathode spots in the literature, the fractal approach to spot interpretation is underutilized. In this work, a brief review of spot properties is given, touching the differences between spot type 1 (on cathodes surfaces with dielectric layers) and spot type 2 (on metallic, clean surfaces) as well as the known spot fragment or cell structure. The basic properties of self-similarity, power laws, random colored noise, and fractals are introduced. Several points of evidence for the fractal nature of spots are provided. Specifically power laws are identified as signature of fractal properties, such as spectral power of noisy arc parameters (ion current, arc voltage, etc) obtained by fast Fourier transform. It is shown that fractal properties can be observed down to the cutoff by measurement resolution or occurrence of elementary steps in physical processes. Random walk models of cathode spot motion are well established: they go asymptotically to Brownian motion for infinitesimal step width. The power spectrum of the arc voltage noise falls as 1/f 2 , where f is frequency, supporting a fractal spot model associated with Brownian motion

  1. El spot electoral negativo

    Directory of Open Access Journals (Sweden)

    Palma Peña-Jiménez

    2011-01-01

    Full Text Available l spot político tiene durante la campaña un objetivo final inequívoco: la consecución del voto favorable. Se dirige al cuerpo electoral a través de la televisión y de Internet, y presenta, en muchos casos, un planteamiento negativo, albergando mensajes destinados a la crítica frontal contra el adversario, más que a la exposición de propuestas propias. Este artículo se centra en el análisis del spot electoral negativo, en aquellas producciones audiovisuales construidas sin más causa que la reprobación del contrincante. Se trata de vídeos que, lejos de emplearse en difundir las potencialidades de la organización y las virtudes de su candidato –además de su programa electoral–, consumen su tiempo en descalificar al oponente mediante la transmisión de mensajes, muchas veces, ad hominem. Repasamos el planteamiento negativo del spot electoral desde su primera manifestación, que en España data de 1996, año de emisión del conocido como vídeo del dóberman, sin olvidar otros ejemplos que completan el objeto de estudio.

  2. Beyond buckling: humidity-independent measurement of the mechanical properties of green nanobiocomposite films.

    Science.gov (United States)

    Gill, Urooj; Sutherland, Travis; Himbert, Sebastian; Zhu, Yujie; Rheinstädter, Maikel C; Cranston, Emily D; Moran-Mirabal, Jose M

    2017-06-14

    Precise knowledge of the mechanical properties of emerging nanomaterials and nanocomposites is crucial to match their performance with suitable applications. While methods to characterize mechanical properties exist, they are limited by instrument sensitivity and sample requirements. For bio-based nanomaterials this challenge is exacerbated by the extreme dependence of mechanical properties on humidity. This work presents an alternative approach, based on polymer shrinking-induced wrinkling mechanics, to determine the elastic modulus of nanobiocomposite films in a humidity-independent manner. Layer-by-layer (LbL) films containing cellulose nanocrystals (CNCs) and water-soluble polymers were deposited onto pre-stressed polystyrene substrates followed by thermal shrinking, which wrinkled the films to give them characteristic topographies. Three deposition parameters were varied during LbL assembly: (1) polymer type (xyloglucan - XG, or polyethyleneimine - PEI); (2) polymer concentration (0.1 or 1 wt%); and (3) number of deposition cycles, resulting in 10-600 nm thick nanobiocomposite films with tuneable compositions. Fast Fourier transform analysis on electron microscopy images of the wrinkled films was used to calculate humidity-independent moduli of 70 ± 2 GPa for CNC-XG 0.1 , 72 ± 2 GPa for CNC-PEI 0.1 , and 32.2 ± 0.8 GPa for CNC-PEI 1.0 films. This structuring method is straightforward and amenable to a wide range of supported thin films.

  3. Measurement of positron reemission from thin single-crystal W(100) films

    International Nuclear Information System (INIS)

    Chen, D.M.; Lynn, K.G.; Pareja, R.; Nielsen, B.

    1985-01-01

    Epitaxial thin single-crystal (100) tungsten films 1000, 2500, and 5000 A thick have been fabricated by high-vacuum electron-beam evaporation. These films were subsequently used as thin-film moderators for the study of the positron-transmission-reemission process with a variable-energy (0--80 keV) monoenergetic positron beam in an ultrahigh-vacuum system. The films were shown to be routinely cleanable by heating first in oxygen (10 -6 Torr) and then in vacuum (10 -9 Torr). Transmission and back reemission of slow positrons from these surfaces was observed. The positron work function, phi/sub +/ has been determined to be approx. =3.0 eV ( +- 0.3 eV). The transmission slow positrons were emitted in a narrow cone with a full width at half maximum of approx. =30 0 consistent with the angular distribution of back-reemission positrons. The reemitted yields as a function of incident positron energy were found to be very different between forward reemission and back reemission. The maximum forward-reemission yields were 18% for 1000-A-thick W film and 12% for 2500-A-thick W film at 5 and 10 keV optimum incident positron energies, respectively. These results show that one can use thin single-crystal tungsten films as positron moderators or remoderators

  4. Adsorptive stripping voltammetric measurements of trace beryllium at the mercury film electrode

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Joseph [Biodesign Institute, Departments of Chemical and Materials Engineering and Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287 (United States)]. E-mail: joseph.wang@asu.edu; Thongngamdee, Sompong [Biodesign Institute, Departments of Chemical and Materials Engineering and Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287 (United States); Lu Donglai [Biodesign Institute, Departments of Chemical and Materials Engineering and Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287 (United States)

    2006-04-06

    A highly sensitive adsorptive stripping voltammetric protocol for measuring trace beryllium, in which the preconcentration is achieved by adsorption of the beryllium-arsenazo-I complex at a preplated mercury-coated carbon-fiber electrode, is described. Optimal conditions were found to be a 0.05 M ammonium buffer (pH 9.7) containing 5 {mu}M arsenazo-I, an accumulation potential of 0.0 V (versus Ag/AgCl) and a square-wave voltammetric scan. The new procedure obviates the need for renewable mercury-drop electrodes used in early stripping protocols for beryllium. A linear response is observed over the 10-60 {mu}g l{sup -1} concentration range (90 s accumulation), along with a detection limit of 0.25 {mu}g l{sup -1} beryllium (10 min accumulation). A 15-s electrochemical cleaning enables the same mercury film to be used for a prolonged operation. High stability is thus indicated from the reproducible response of a 100 {mu}g l{sup -1} beryllium solution (n = 60; RSD = 3.3%) over a 2.5-h operation. Applicability to a seawater sample is illustrated. The attractive behavior of the new sensor holds great promise for on-site environmental and industrial monitoring of beryllium. Preliminary data in this direction using mercury-coated screen-printed electrodes are encouraging.

  5. Adsorptive stripping voltammetric measurements of trace beryllium at the mercury film electrode

    International Nuclear Information System (INIS)

    Wang, Joseph; Thongngamdee, Sompong; Lu Donglai

    2006-01-01

    A highly sensitive adsorptive stripping voltammetric protocol for measuring trace beryllium, in which the preconcentration is achieved by adsorption of the beryllium-arsenazo-I complex at a preplated mercury-coated carbon-fiber electrode, is described. Optimal conditions were found to be a 0.05 M ammonium buffer (pH 9.7) containing 5 μM arsenazo-I, an accumulation potential of 0.0 V (versus Ag/AgCl) and a square-wave voltammetric scan. The new procedure obviates the need for renewable mercury-drop electrodes used in early stripping protocols for beryllium. A linear response is observed over the 10-60 μg l -1 concentration range (90 s accumulation), along with a detection limit of 0.25 μg l -1 beryllium (10 min accumulation). A 15-s electrochemical cleaning enables the same mercury film to be used for a prolonged operation. High stability is thus indicated from the reproducible response of a 100 μg l -1 beryllium solution (n = 60; RSD = 3.3%) over a 2.5-h operation. Applicability to a seawater sample is illustrated. The attractive behavior of the new sensor holds great promise for on-site environmental and industrial monitoring of beryllium. Preliminary data in this direction using mercury-coated screen-printed electrodes are encouraging

  6. [Study on Hexagonal Super-Lattice Pattern with Light Spot and Dim Spot in Dielectric Barrier Discharge by Optical Emission Spectra].

    Science.gov (United States)

    Liu, Ying; Dong, Li-fang; Niu, Xue-jiao; Zhang, Chao

    2016-02-01

    The hexagonal super-lattice pattern composed of the light spot and the dim spot is firstly observed and investigated in the discharge of gas mixture of air and argon by using the dielectric barrier discharge device with double water electrodes. It is found that the dim spot is located at the center of its surrounding three light spots by observing the discharge image. Obviously, the brightness of the light spot and the dim spot are different, which indicates that the plasma states of the light spot and the dim spot may be different. The optical emission spectrum method is used to further study the several plasma parameters of the light spot and the dim spot in different argon content. The emission spectra of the N₂ second positive band (C³IIu --> B³IIg) are measured, from which the molecule vibration temperatures of the light spot and the dim spot are calculated. Based on the relative intensity ratio of the line at 391.4 nm and the N₂ line at 394.1 nm, the average electron energies of the light spot and the dim spot are investigated. The broadening of spectral line 696.57 nm (2P₂-1S₅) is used to study the electron densities of the light spot and the dim spot. The experiment shows that the molecule vibration temperature, average electron energy and the electron density of the dim spot are higher than those of the light spot in the same argon content. The molecule vibration temperature and electron density of the light spot and dim spot increase with the argon content increasing from 70% to 95%, while average electron energies of the light spot and dim spot decrease gradually. The short-exposure image recorded by a high speed video camera shows that the dim spot results from the surface discharges (SDs). The surface discharge induced by the volume discharge (VD) has the decisive effect on the formation of the dim spot. The experiment above plays an important role in studying the formation mechanism of the hexagonal super-lattice pattern with light spot and

  7. Measurement of Adhesion Strength of DLC Film Prepared by Utilizing Plasma-Based Ion Implantation

    Science.gov (United States)

    Oka, Yoshihiro; Yatsuzuka, Mitsuyasu

    High-adhesion diamond-like carbon (DLC) film was prepared by a hybrid process of plasma-based ion implantation and deposition using superimposed RF and high-voltage pulses. The adhesion strength of DLC film on a stainless steel (SUS304) was enhanced by the carbon ion implantation to the substrate. Furthermore, ion implantation of mixed carbon and silicon led to considerable enhancement of adhesion strength above the resin glue strength. The adhesion strength of DLC film on the aluminum alloy (A-5052) was improved above the resin glue strength only by the carbon ion implantation to the substrate.

  8. Measurement of activity distribution in an Am-241 disc source using peeled-off Gafchromic EBT3 films.

    Science.gov (United States)

    Lee, Kwang-Ho; Shin, Ji-Yong; Kim, Eun-Hee

    2018-05-01

    Commercial alpha-emitting sources are fabricated mainly in a disc type. An alpha particle irradiator in Radiation Bioengineering Laboratory at Seoul National University was installed with an Am-241 disc source. Commercial Am-241 disc sources are fabricated by incorporating the radioactive element into a thin substrate layer. Those disc sources are utilized assuming that the radioactive element is uniformly distributed in the active layer of disc sources. In this study, we employed peeled-off Gafchromic EBT3 films to investigate the uniformity of areal radioactivity density over the disc source and to measure the effect of non-uniform activity distribution on dose distribution at the bottom of the cell culture dish positioned in a varying distance from the source. The measurements with the peeled-off EBT3 films informed that the areal activity density in the disc source differed by up to approximately 45% from the average. However, the inhomogeneous Am-241 distribution in a disc source did not affect the radial distribution of fluence rate at the inner bottom of cell dish when the dish is apart from the source sufficiently. The dose distribution measured with an EBT3 film nearly accorded with that obtained by Monte Carlo simulation assuming the uniform Am-241 activity distribution in the active layer of the disc source. Finally, the dose to a single-cell layer of 5 μm in a nominal thickness was obtained by Monte Carlo simulation assuming a uniform Am-241 activity distribution in the disc source at distances of 20 and 30 mm from the source. The cellular dose estimates were higher than the film dose estimates at all radial distances. The cellular dose decreased with an increasing radial distance from the center to a smaller extent than the EBT3 film dose did. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Thin-film-based CdTe photovoltaic module characterization: Measurements and energy prediction improvement

    Science.gov (United States)

    Lay-Ekuakille, A.; Arnesano, A.; Vergallo, P.

    2013-01-01

    Photovoltaic characterization is a topic of major interest in the field of renewable energy. Monocrystalline and polycrystalline modules are mostly used and, hence characterized since many laboratories have data of them. Conversely, cadmium telluride (CdTe), as thin-film module are, in some circumstances, difficult to be used for energy prediction. This work covers outdoor testing of photovoltaic modules, in particular that regarding CdTe ones. The scope is to obtain temperature coefficients that best predict the energy production. A First Solar (K-275) module has been used for the purposes of this research. Outdoor characterizations were performed at Department of Innovation Engineering, University of Salento, Lecce, Italy. The location of Lecce city represents a typical site in the South Italy. The module was exposed outdoor and tested under clear sky conditions as well as under cloudy sky ones. During testing, the global-inclined irradiance varied between 0 and 1500 W/m2. About 37 000 I-V characteristics were acquired, allowing to process temperature coefficients as a function of irradiance and ambient temperature. The module was characterized by measuring the full temperature-irradiance matrix in the range from 50 to 1300 W/m2 and from -1 to 40 W/m2 from October 2011 to February 2012. Afterwards, the module energy output, under real conditions, was calculated with the "matrix method" of SUPSI-ISAAC and the results were compared with the five months energy output data of the same module measured with the outdoor energy yield facility in Lecce.

  10. Thin-film-based CdTe photovoltaic module characterization: measurements and energy prediction improvement.

    Science.gov (United States)

    Lay-Ekuakille, A; Arnesano, A; Vergallo, P

    2013-01-01

    Photovoltaic characterization is a topic of major interest in the field of renewable energy. Monocrystalline and polycrystalline modules are mostly used and, hence characterized since many laboratories have data of them. Conversely, cadmium telluride (CdTe), as thin-film module are, in some circumstances, difficult to be used for energy prediction. This work covers outdoor testing of photovoltaic modules, in particular that regarding CdTe ones. The scope is to obtain temperature coefficients that best predict the energy production. A First Solar (K-275) module has been used for the purposes of this research. Outdoor characterizations were performed at Department of Innovation Engineering, University of Salento, Lecce, Italy. The location of Lecce city represents a typical site in the South Italy. The module was exposed outdoor and tested under clear sky conditions as well as under cloudy sky ones. During testing, the global-inclined irradiance varied between 0 and 1500 W/m(2). About 37,000 I-V characteristics were acquired, allowing to process temperature coefficients as a function of irradiance and ambient temperature. The module was characterized by measuring the full temperature-irradiance matrix in the range from 50 to 1300 W/m(2) and from -1 to 40 W/m(2) from October 2011 to February 2012. Afterwards, the module energy output, under real conditions, was calculated with the "matrix method" of SUPSI-ISAAC and the results were compared with the five months energy output data of the same module measured with the outdoor energy yield facility in Lecce.

  11. A polymeric dosimeter film based on optically-stimulated luminescence for dose measurements below 1 kGy

    International Nuclear Information System (INIS)

    Kovacs, A.; Baranyai, M.; Wojnarovits, L.; Slezsak, I.; McLaughlin, W.L.; Miller, S.D.; Miller, A.; Fuochi, P.G.; Lavalle, M.

    1999-01-01

    A new potential dosimetry system 'Sunna' containing a microcrystalline dispersion of an optically-stimulated fluor in a plastic matrix has been recently developed to measure and image high doses. Our previous investigations have revealed that the new dosimeter system is capable of measuring absorbed doses in the dose range of 1-100 kGy. The optically-stimulated luminescence (OSL) analysis is based on the blue light stimulation of the colour center states produced upon irradiation, and the intensity of the resulting red-light emission is used to measure absorbed dose. This analysis is carried out with a simple table-top fluorimeter developed for this purpose having also the ability to calculate the mathematical formula of the calibration function. The Sunna dosimeter was recently investigated for potential use in lower dose range below 1 kGy. These investigations have shown that the film is suitable for measuring doses in the range of 1-1000 Gy for both electron and gamma radiation. To test the applicability of the film, its reproducibility, stability, sensitivity to ambient and UV light and irradiation temperature were measured. The stability of the dosimeter was investigated by monitoring the change of the OSL signal with storage time after irradiation. Further experiments proved the homogeneity of the film with respect to thickness variation, and limited differences in its response were found between batches. (author)

  12. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    Directory of Open Access Journals (Sweden)

    John E Fa

    Full Text Available Wild animals are a primary source of protein (bushmeat for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165 in Central Africa to map areas of high species richness (hot spots and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability, weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  13. Measuring the Thickness and Elastic Properties of Electroactive Thin-film Polymers Using Platewave Dispersion Data

    Science.gov (United States)

    El-Azab, A.; Mal, A. K.; Bar-Cohen, Y.; Lih, S.

    1996-01-01

    Electroactive thin-film polymers are candidate sensors and actuators materials [1,2]. They are also finding a significant potential for applications in muscle mechanisms and micro-electro-mechanical systems (MEMS).

  14. Relationship between thin-film bond strength as measured by a scratch test, and indentation hardness for bonding agents.

    Science.gov (United States)

    Kusakabe, Shusuke; Rawls, H Ralph; Hotta, Masato

    2016-03-01

    To evaluate thin-film bond strength between a bonding agent and human dentin, using a scratch test, and the characteristics and accuracy of measurement. One-step bonding agents (BeautiBond; Bond Force; Adper Easy Bond; Clearfil tri-S Bond) and two-step bonding agents (Cleafil SE Bond; FL-Bond II) were investigated in this study. Flat dentin surfaces were prepared for extracted human molars. The dentin surfaces were ground and bonding agents were applied and light cured. The thin-film bond strength test of the specimens was evaluated by the critical load at which the coated bonding agent failed and dentin appeared. The scratch mark sections were then observed under a scanning electron microscope. Indentation hardness was evaluated by the variation in depth under an applied load of 10gf. Data were compared by one-way ANOVA with the Scheffé's post hoc multiple comparison test (pstrength and indentation hardness were analyzed using analysis of correlation and covariance. The thin-film bond strength of two-step bonding agents were found to be significantly higher than that of one-step bonding agents with small standard deviations. Scratch marks consistently showed adhesive failure in the vicinity of the bonding agent/dentin interface. The indentation hardness showed a trend that two-step bonding agents have greater hardness than one-step bonding agents. A moderately significant correlation (r(2)=0.31) was found between thin-film bond strength and indentation hardness. Thin-film bond strength test is a valid and reliable means of evaluating bond strength in the vicinity of the adhesive interface and is more accurate than other methods currently in use. Further, the thin-film bond strength is influenced by the hardness of the cued bonding agent. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  15. Thickness measurement of aluminum, titanium, titanium silicide, and tungsten silicide films by x-ray fluorescence

    International Nuclear Information System (INIS)

    Ernst, S.; Lee, C.O.; Lee, J.J.

    1988-01-01

    X-ray fluorescence (XRF) has received a great deal of attention in the last few years as a quantitative means of determining both the stoichiometry and thickness of many different kinds of films. Examples include Ag and Cu films on mica substrates, Sn-Pb alloys on steel substrates, Al-Ti multilayers on Cu substrates and oxide films on silicon substrates. In XRF the sample is irradiated with x-rays which in turn cause x-rays to be given off by the sample. These x-rays that are given off by the sample can then be analyzed both for energy and intensity. The energy of the x-rays is characteristic of the elemental makeup of the sample and the intensity of the x-rays is dependent on how much of the particular element is present. The intensity then can be related to the thickness of a film if the stoichiometry of the film can be assumed constant. With the increased interest in silicides and more recently, the self-aligned silicide (salicide) process (8-10) for VLSI applications, in-line process monitoring of silicide film thickness has become important to integrated circuit manufacturing. In this study, the number of x-ray photons given of by Al, Ti, titanium silicide, and tungsten silicide films on silicon-based substrates was quantified so that a film thickness for an unknown sample could then be determined easily. In addition, XRF is a more accurate technique, limited principally by the accuracy technique, limited principally by the accuracy of the reference used and the amount of time the x-ray photons are counted

  16. Dynamic characterization of the CT angiographic 'spot sign'.

    Directory of Open Access Journals (Sweden)

    Santanu Chakraborty

    Full Text Available BACKGROUND AND PURPOSE: Standard (static CT angiography is used to identify the intracerebral hemorrhage (ICH spot sign. We used dynamic CT-angiography to describe spot sign characteristics and measurement parameters over 60-seconds of image acquisition. METHODS: We prospectively identified consecutive patients presenting with acute ICH within 4.5 hours of symptom onset, and collected whole brain dynamic CT-angiography (dCTA. Spot parameters (earliest appearance, duration, maximum Hounsfield unit (HU, time to maximum HU, time to spot diagnostic definition, spot volume and hematoma volumes were measured using volumetric analysis software. RESULT: We enrolled 34 patients: three were excluded due to secondary causes of ICH. Of the remaining 31 patients there were 18 females (58% with median age 70 (range 47-86 and baseline hematoma volume 33 ml (range 0.7-103 ml. Positive dCTA spot sign was present in 13 patients (42% visualized as an expanding 3-dimensional structure temporally evolving its morphology over the scan period. Median time to spot appearance was 21 s (range 15-35 seconds. This method allowed tracking of spots evolution until the end of venous phase (active extravasation with median duration of 39 s (range 25-45 seconds. The average density and time to maximum density was 204HU and 30.8 s (range 23-31 s respectively. Median time to spot diagnosis was 20.8 s using either 100 or 120HU definitions. CONCLUSION: Dynamic CTA allows a 3-dimensional assessment of spot sign formation during acute ICH, and captured higher spot sign prevalence than previously reported. This is the first study to describe and quantify spot sign characteristics using dCTA; these can be used in ongoing and upcoming ICH studies.

  17. Thinning and rupture of liquid films by moving slot jets.

    Science.gov (United States)

    Berendsen, Christian W J; Zeegers, Jos C H; Darhuber, Anton A

    2013-12-23

    We present systematic experiments of the rupture and dewetting of thin films of a nonvolatile polar liquid on partially wetting substrates due to a moving slot jet, which impinges at normal incidence. The relative motion was provided by a custom-built spin coater with a bidirectionally accessible axis of rotation that enabled us to measure film thickness profiles in situ as a function of substrate velocity using dual-wavelength interference microscopy. On partially wetting polymeric substrates, dry spots form in liquid films with a residual thickness well below 1 μm. We measured the density of dry spots as well as the density and size distribution of the residual droplets as a function of film thickness. In a certain parameter range, the droplet distributions exhibit pronounced anisotropy due to the effect of long-range shear stresses on the dewetting rim instability. We find robust power-law scaling relations over a large range of film thicknesses and a striking similarity to literature data obtained with ultrathin polymer melt layers on silicon substrates.

  18. Identification of electricity spot models by using convolution particle filter

    NARCIS (Netherlands)

    Aihara, ShinIchi; Bagchi, Arunabha; Imreizeeq, E.S.N.

    2011-01-01

    We consider a slight perturbation of the Schwartz-Smith model for the electricity futures prices and the resulting modied spot model. Using the martingale property of the modied price under the risk neutral measure, we derive the arbitrage free model for the spot and futures prices. As the futures

  19. Parameter estimation of electricity spot models from futures prices

    NARCIS (Netherlands)

    Aihara, ShinIchi; Bagchi, Arunabha; Imreizeeq, E.S.N.; Walter, E.

    We consider a slight perturbation of the Schwartz-Smith model for the electricity futures prices and the resulting modified spot model. Using the martingale property of the modified price under the risk neutral measure, we derive the arbitrage free model for the spot and futures prices. We estimate

  20. I. Measuring and Reducing Stress and Surface Roughness in IBAD MgO Films and II. Developing Tools to Measure Transfer in Undergraduate Chemistry Students

    Science.gov (United States)

    Antonakos, Cory Dale

    I. MgO may be grown with a biaxial texture onto an amorphous substrate with the use of ion beam assisted deposition (IBAD). This MgO film may then be used as a platform on which to grow epitaxial films on an amorphous membrane for characterization purposes. However, the IBAD MgO film is stressed, causing buckles in the amorphous membrane and problems with further film growth on the IBAD MgO. This dissertation work explores the source of this film stress and develops methods to relax the stress and reduce surface roughness with annealing and increased growth temperature. It is determined that annealing and increased growth temperature coupled with a higher ion-to-atom ratio (IAR) during film growth reduce stress and surface roughness sufficiently to use even thinner IBAD MgO films as an intermediate layer between an amorphous membrane and epitaxial film. II. Much of the existing literature on knowledge transfer concludes that transfer is rare and does not occur spontaneously. However, studies supporting that transfer is rare often use methods that focus on binary success or failure to solve a problem correctly and do not analyze thought process. This dissertation work aims at developing transfer questions that allow open-ended responses, developing a method of analysis for these responses that looks for transfer in the problem-solving process, and assessing the methodology itself and its sensitivity, validity, and utility as a general transfer measurement technique for use across a broad range of expertise levels in chemistry. Detailed analysis of responses to each transfer question show that some transfer questions are more effective at distinguishing between expertise levels while also allowing responders of all levels to show knowledge transfer. Simpler questions that are more accessible to students of introductory chemistry proved the most useful at eliciting a range of responses that correlate with expertise level while still showing some degree of transfer in

  1. Ellipsometry measurements of glass transition breadth in bulk films of random, block, and gradient copolymers.

    Science.gov (United States)

    Mok, M M; Kim, J; Marrou, S R; Torkelson, J M

    2010-03-01

    Bulk films of random, block and gradient copolymer systems were studied using ellipsometry to demonstrate the applicability of the numerical differentiation technique pioneered by Kawana and Jones for studying the glass transition temperature (T (g)) behavior and thermal expansivities of copolymers possessing different architectures and different levels of nanoheterogeneity. In a series of styrene/n -butyl methacrylate (S/nBMA) random copolymers, T (g) breadths were observed to increase from approximately 17( degrees ) C in styrene-rich cases to almost 30( degrees ) C in nBMA-rich cases, reflecting previous observations of significant nanoheterogeneity in PnBMA homopolymers. The derivative technique also revealed for the first time a substantial increase in glassy-state expansivity with increasing nBMA content in S/nBMA random copolymers, from 1.4x10(-4) K-1 in PS to 3.5x10(-4) K-1 in PnBMA. The first characterization of block copolymer T (g) 's and T (g) breadths by ellipsometry is given, examining the impact of nanophase-segregated copolymer structure on ellipsometric measurements of glass transition. The results show that, while the technique is effective in detecting the two T (g) 's expected in certain block copolymer systems, the details of the glass transition can become suppressed in ellipsometry measurements of a rubbery minor phase under conditions where the matrix is glassy; meanwhile, both transitions are easily discernible by differential scanning calorimetry. Finally, broad glass transition regions were measured in gradient copolymers, yielding in some cases extraordinary T (g) breadths of 69- 71( degrees ) C , factors of 4-5 larger than the T (g) breadths of related homopolymers and random copolymers. Surprisingly, one gradient copolymer demonstrated a slightly narrower T (g) breadth than the S/nBMA random copolymers with the highest nBMA content. This highlights the fact that nanoheterogeneity relevant to the glass transition response in selected

  2. Influence of red blood cell concentrations on the measurement of turbulence using hot-film anemometer.

    Science.gov (United States)

    Sallam, A M; Hwang, N H

    1983-11-01

    Measurement of local velocity fluctuations was made with an L-shaped conical hot-film probe in a submerged circular jet. The experiment was carried out in solutions of washed human red blood cells (RBC) in a phosphate buffer solution (PBS), at hematocrit concentrations (Ht percent) of 10, 19, 29, and 38 percent. The viscosity of the testing solutions was kept at 3.2 c.p. by adding proper amount of dextran. The experiment was conducted at Reynolds numbers (NR) 674, 963, 1255 and 1410, based on the jet exit velocity and exit diameter. Statistical analyses were performed on the recorded instantaneous velocity signals to obtain the root-mean-square (rms) values, the probability density functions (PDF) and the power spectral density functions (PSDF) of the signals. Within the range tested, we noticed an incidental rise in rms values at 19 to 29 Ht percent for NR = 963 similar to those reported earlier in the literature. Further analyses using PDF and PSDF, however, showed neither a trend nor any physical significance of this rise. Based on the analyses of both the PDF and the PSDF, we believe that the incidental rise in rms value can be partially attributed to the high spikes registered by the probe in a high RBC concentrations fluid flow. The bombardment of RBC on the probe thermal boundary layer may cause a characteristic change in the probe response to certain flow phenomenon, at least within the Reynolds number range used in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. In situ measurement of humidity induced changes in the refractive index and thickness of polyethylene glycol thin films

    Science.gov (United States)

    Bilen, Bukem; Skarlatos, Yani; Aktas, Gulen; Inci, M. Naci; Dispinar, Tugba; Kose, M. Merve; Sanyal, Amitav

    2008-11-01

    Humidity induced changes in the refractive index and thickness of polyethylene glycol (PEG) thin films are in situ determined by optical waveguide spectroscopy. PEG brushes are covalently attached to the surface of a thin gold film on a borosilicate crown glass (BK7) using a grafting-from chemical synthesis technique. The measurements are carried out in an attenuated total internal reflection setup. At low humidity levels, both the refractive index and the thickness change gradually due to swelling of the PEG thin films upon water intake. At around 80% relative humidity, a steep decrease in the refractive index and a steep increase in the thickness are observed as a result of a phase change from a semicrystalline state to a physical gel state. The hydrogenation of PEG films causes a less pronounced phase change from a semicrystalline state to a gel state. Due to fewer ether oxygen atoms available for the water molecules to make hydrogen bonding, the polymer has a more stable structure than before and the phase change is observed to shift to higher humidity levels. It is discussed that such a humidity induced change in the index of refraction can be utilized in constructing of a PEG based humidity sensor.

  4. Measurement of Young’s modulus and volumetric mass density/thickness of ultrathin films utilizing resonant based mass sensors

    Czech Academy of Sciences Publication Activity Database

    Stachiv, Ivo; Vokoun, David; Jeng, Y.-R.

    2014-01-01

    Roč. 104, č. 8 (2014), "083102-1"-"083102-4" ISSN 0003-6951 R&D Projects: GA ČR GAP107/12/0800 Institutional support: RVO:68378271 Keywords : functional films * mass sensor * resonant frequency Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 3.302, year: 2014 http://scitation.aip.org/content/aip/journal/apl/104/8/10.1063/1.4866417

  5. Measurement of Pressure between Upper Airway Tract and Laryngoscope Blade during Orotracheal Intubation with Film of Microcapsules

    Directory of Open Access Journals (Sweden)

    Shigehiro Hashimoto

    2014-04-01

    Full Text Available The measurement system for the pressure between the blade of a laryngoscope and the upper airway tract during orotracheal intubation has been investigated with a film of microcapsules. Two types of the laryngoscope were used in the study: Wis-Foregger and Mac-Intosh. The film is attached on the surface of the blade of the laryngoscope. The measurement was applied to 20 cases of the orotracheal intubation. In the pressed part of the film, the microcapsules burst and release chemicals, which react with chemicals out of microcapsules and show a red color. The color density was photoelectrically measured, and converted to the pressure value in three regions on the blade; the epiglottis, the tongue, and the upper incisor. The results show that the pressures are 1.2±0.6 MPa on the epiglottis, 0.8±0.4 MPa on the tongue, and (11±3×10 MPa on the upper incisor, and that the pressures on the epiglottis are 2.0±0.3 MPa in bled cases, and 0.8±0.4 MPa in non-bled cases.

  6. ToF-MEIS stopping measurements in thin SiC films

    International Nuclear Information System (INIS)

    Linnarsson, M.K.; Khartsev, S.; Primetzhofer, D.; Possnert, G.; Hallén, A.

    2014-01-01

    Electronic stopping in thin, amorphous, SiC films has been studied by time-of-flight medium energy ion scattering and conventional Rutherford backscattering spectrometry. Amorphous SiC films (8, 21 and 36 nm) were prepared by laser ablation using a single crystalline silicon carbide target. Two kinds of substrate films, one with a lower atomic mass (carbon) and one with higher atomic mass (iridium) compared to silicon has been used. Monte Carlo simulations have been used to evaluate electronic stopping from the shift in energy for the signal scattered from Ir with and without SiC. The two kinds of samples are used to illustrate the strength and challenges for ToF-MEIS compared to conventional RBS

  7. Measurement of residual stresses in deposited films of SOFC component materials

    Energy Technology Data Exchange (ETDEWEB)

    Kato, T.; Momma, A.; Nagata, S.; Kasuga, Y. [Electrotechnical Lab., Ibaraki (Japan)

    1996-12-31

    The stress induced in Solid oxide fuel cells (SOFC)s has important influence on the lifetime of SOFC. But the data on stress in SOFC and mechanical properties of SOW component materials have not been accumulated enough to manufacture SOFC. Especially, the data of La{sub 1-x}Sr{sub x}MnO{sub 3} cathode and La{sub 1-x}Sr{sub x}CrO{sub 3} interconnection have been extremely limited. We have estimated numerically the dependences of residual stress in SOFC on the material properties, the cell structure and the fabrication temperatures of the components, but these unknown factors have caused obstruction to simulate the accurate behavior of residual stress. Therefore, the residual stresses in deposited La{sub 1-x}Sr{sub x}MnO{sub 3} and La{sub 1-x}Sr{sub x}CrO{sub 3} films are researched by the observation of the bending behavior of the substrate strips. The films of SOFC component materials were prepared by the RF sputtering method, because: (1) It can fabricate dense films of poor sinterable material such as La{sub 1-x}Sr{sub x}CrO{sub 3} compared with sintering or plasma spray method. (2) For the complicated material such as perovskite materials, the difference between the composition of a film and that of a target material is generally small. (3) It can fabricate a thick ceramics film by improving of the deposition rate. For example, Al{sub 2}O{sub 3} thick films of 50{mu}m can be fabricated with the deposition rate of approximately 5{mu}m/h industrially. In this paper, the dependence of residual stress on the deposition conditions is defined and mechanical properties of these materials are estimated from the results of the experiments.

  8. Ultrafast Carrier Dynamics Measured by the Transient Change in the Reflectance of InP and GaAs Film

    Energy Technology Data Exchange (ETDEWEB)

    Klopf, John [Helmholtz Association of German Research Centers, Dresden (Germany)

    2005-10-31

    Advancements in microfabrication techniques and thin film growth have led to complex integrated photonic devices, also known as optoelectronics. The performance of these devices relies upon precise control of the band gap and optical characteristics of the thin film structures, as well as a fundamental understanding of the photoexcited carrier thermalization, relaxation, and recombination processes. An optical pump-probe technique has been developed to measure the transient behavior of these processes on a sub-picosecond timescale. This method relies upon the generation of hot carriers by theabsorption of an intense ultrashort laser pulse (~ 135 fs). The transient changes in reflectance due to the pump pulse excitation are monitored using a weaker probe pulse. Control of the relative time delay between the pump and probe pulses allows for temporal measurements with resolution limited only by the pulse width. The transient change in reflectance is the result of a transient change in the carrier distribution. Observation of the reflectance response of indium phosphide (InP) and gallium arsenide (GaAs) films on a sub-picosecond timescale allows for detailed examination of thermalization and relaxation processes of the excited carriers. Longer timescales (> 100 ps) are useful for correlating the transient reflectance response to slower processes such as the diffusion and recombination of the photoexcited carriers. This research investigates the transient hot carrier processes in several InP and GaAs based films similar to those commonly used in optoelectronics. This technique is especially important as it provides a non-destructive means of evaluating these materials; whereas much of the research performed in this field has relied upon the measurement of transient changes in the transmission of transparent films. The process of preparing films that are transparent renders them unusable in functioning devices. This research should not only extend the understanding of

  9. Numerical restoration of surface vortices in Nb films measured by a scanning SQUID microscope

    Science.gov (United States)

    Ito, Atsuki; Thanh Huy, Ho; Dang, Vu The; Miyoshi, Hiroki; Hayashi, Masahiko; Ishida, Takekazu

    2017-07-01

    In the present work, we investigated a vortex profile appeared on a pure Nb film (500 nm in thickness, 10 mm x 10 mm) by using a scanning SQUID microscope. We found that the local magnetic distribution thus observed is broadened compared to a true vortex profile in the superconducting film. We therefore applied the numerical method to improve a spatial resolution of the scanning SQUID microscope. The method is based on the inverse Biot-Savart law and the Fourier transformation to recover a real-space image. We found that the numerical analyses give a smaller vortex than the raw vortex profile observed by the scanning microscope.

  10. Elastic properties of boron carbide films via surface acoustic waves measured by Brillouin light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Salas, E.; Jimenez-Villacorta, F.; Jimenez Rioboo, R.J.; Prieto, C. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Sanchez-Marcos, J. [Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones Cientificas, Cantoblanco, 28049 Madrid (Spain); Departamento de Quimica-Fisica Aplicada, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Munoz-Martin, A.; Prieto, J.E.; Joco, V. [Centro de Microanalisis de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2013-03-15

    Surface acoustic wave (SAW) velocity has been determined by high resolution Brillouin light scattering to study the mechano-elastic properties of boron carbide films prepared by radio frequency (RF) sputtering. The comparison of experimentally observed elastic behaviour with simulations made by considering film composition obtained from elastic recoil detection analysis-time of flight (ERDA-ToF) spectroscopy allows establishing that elastic properties are determined by that of crystalline boron carbide with a lessening of the SAW velocity values due to surface oxidation. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Ultrasonic assessment of tension shear strength in resistance spot welding

    Science.gov (United States)

    Moghanizadeh, Abbas

    2015-05-01

    Resistance spot welding is extensively used to join sheet steel in the automotive industry. Ultrasonic non-destructive techniques for evaluation of the mechanical properties of resistance spot welding are presented. The aim of this study is to develop the capability of the ultrasonic techniques as an efficient tool in the assessment of the welding characterization. Previous researches have indicated that the measurements of ultrasonic attenuation are sensitive to grain- size variations in an extensive range of metallic alloys. Other researchers have frequently described grain sizes which are able to have significant effects on the physical characteristics of the material. This research provides a novel method to estimate the tension-shear strengths of the resistance spot welding directly from the ultrasonic attenuation measurements. The effects of spot welding parameters on the ultrasonic waves are further investigated. The results confirm that it is possible to determine the spot welding parameters for individual quality by using ultrasonic test.

  12. [Epidemiologic study of tear film lipid layer thickness measurement in the population of Taishitun Community in Beijing].

    Science.gov (United States)

    Liang, Q F; Du, X H; Su, Y D; Wang, N L; Wei, Z J; Labbé, Antoine

    2017-07-11

    Objective: To investigate the distribution of tear film lipid layer thickness (LLT) and the relationship between symptoms and signs of dry eye and tear film LLT in the population of Taishitun Community in Beijing. Methods: A cross-sectional study. From May 2016 to August 2016, three streets of Taishitun Community were randomly selected as survey districts and 540 persons were taken as investigation subjects. Every participant completed 6 items of dry eye examinations as follows: questionnaire (Ocular Surface Disease Index, OSDI), measurement of tear film LLT, tear film break-up time (TBUT), corneal and conjunctival staining, SchirmerⅠtest and the infrared meibomian photography. According to their age, all participants were divided into four groups: junior group (analysis and multivariate Logistic regression analysis, distribution of the variables of LLT and the relationship between dry eye symptoms and LLT were studied. Results: A total of 473 residents finally participated in this study, and the response ratio was 87.6%. The values of LLT were normally distributed. The average LLT was (59.87±18.50) nm [(60.16±19.15) nm in males and (59.67±18.57) nm in females], and the comparison of LLT with different genders was not statistically significant ( t= 0.198, P= 0.843). The tear film LLT of four different age groups had statistical significance ( F= 15.092, P0.05. F= 0.538, P >0.05). In the OSDI symptom questionnaire, only blurred vision and decreased visual acuity were related to the tear film LLT ( Pfilm LLT ( P> 0.05). Conclusions: In Taishitun Community of Beijing, the values of tear film LLT had a normal distribution. The LLT was positively correlated with age, but inversely correlated with the severity of the symptoms of dry eye. There was no significant correlation between the LLT and the TBUT, SchirmerⅠtest result and meibomian gland loss rate. (Chin J Ophthalmol, 2017, 53: 495-501) .

  13. Combined optical gain and degradation measurements in DCM2 doped Tris-(8-hydroxyquinoline)aluminum thin-films

    Science.gov (United States)

    Čehovski, Marko; Döring, Sebastian; Rabe, Torsten; Caspary, Reinhard; Kowalsky, Wolfgang

    2016-04-01

    Organic laser sources offer the opportunity to integrate flexible and widely tunable lasers in polymer waveguide circuits, e.g. for Lab-on-Foil applications. Therefore, it is necessary to understand gain and degradation processes for long-term operation. In this paper we address the challenge of life-time (degradation) measurements of photoluminescence (PL) and optical gain in thin-film lasers. The well known guest-host system of aluminum-chelate Alq3 (Tris-(8-hydroxyquinoline)aluminum) as host material and the laser dye DCM2 (4-(Dicyanomethylene)-2- methyl-6-julolidyl-9-enyl-4H-pyran) as guest material is employed as laser active material. Sample layers have been built up by co-evaporation in an ultrahigh (UHV) vacuum chamber. 200nm thick films of Alq3:DCM2 with different doping concentrations have been processed onto glass and thermally oxidized silicon substrates. The gain measurements have been performed by the variable stripe length (VSL) method. This measurement technique allows to determine the thin-film waveguide gain and loss, respectively. For the measurements the samples were excited with UV irradiation (ƛ = 355nm) under nitrogen atmosphere by a passively Q-switched laser source. PL degradation measurements with regard to the optical gain have been done at laser threshold (approximately 3 μJ/cm2), five times above laser threshold and 10 times above laser threshold. A t50-PL lifetime of > 107 pulses could be measured at a maximum excitation energy density of 32 μJ/cm2. This allows for a detailed analysis of the gain degradation mechanism and therefore of the stimulated cross section. Depending on the DCM2 doping concentration C the stimulated cross section was reduced by 35 %. Nevertheless, the results emphasizes the necessity of the investigation of degradation processes in organic laser sources for long-term applications.

  14. Critical current density measurement of thin films by AC susceptibility based on the penetration parameter h

    DEFF Research Database (Denmark)

    Li, Xiao-Fen; Grivel, Jean-Claude; Abrahamsen, Asger B.

    2012-01-01

    current density Jc of superconducting thin films by AC susceptibility. Compared with the normally used method based on the peak of the imaginary part, our method uses a much larger range of the AC susceptibility curve, thus allowing determination of the temperature (T) dependence of Jc from a normally...

  15. Design of efficient loadcell for measurement of mechanical impact by piezoelectric PVDF film sensor

    Directory of Open Access Journals (Sweden)

    Priyanka Guin

    2016-09-01

    Full Text Available Conversion efficiency of mechanical impact into electrical voltage remains ever increasing demand for piezoelectric PVDF film sensor. For a given film sensor, the output voltage produced due to mechanical impact is highly dependent on the direction of stretching (or compressing and active area of the film sensor. More is the active area of the film; higher will be the output voltage. It is shown that the active area is significantly increased due to the ridge-like shape given at the inner surfaces of the plates of sandwich type loadcell and as a result of which higher conversion efficiency is obtained. The effectiveness of the ridge-like shape is confirmed statistically by conducting two factorial design of experiment in which shape and material of the loadcell are considered as the two factors with 2×4 matrix. In case of loadcell made of glass plates, more than 100% increase in the output voltage is observed for ridge-like shape in comparison to its plain counterpart. Both the bandwidth and frequency range of the output signal is found to be independent and dependent of the loadcell materials for indirect and direct impact with the loadcell respectively. The merits and demerits of the fabricated loadcells are discussed.

  16. Measuring and modelling of diffusivities in carbohydrate-rich matrices during thin film drying

    NARCIS (Netherlands)

    Perdana, J.A.; Sman, van der R.G.M.; Fox, M.B.; Boom, R.M.; Schutyser, M.A.I.

    2014-01-01

    Knowledge about moisture diffusivity in solid matrices is a key for understanding drying behaviour of for example probiotic or enzymatic formulations. This paper presents an experimental procedure to determine moisture diffusivity on the basis of thin film drying and gravimetric analysis in a

  17. Dose determination with nitro blue tetrazolium containing radiochromic dye films by measuring absorbed and reflected light

    DEFF Research Database (Denmark)

    Kovács, A.; Baranyai, M.; Wojnárovits, L.

    2000-01-01

    Tetrazolium salts as heterocyclic organic compounds are known to form highly coloured, water insoluble formazans by reduction, which can be utilized in radiation processing dosimetry. Radiochromic films containing nitro blue tetrazolium dissolved in a polymer matrix were found suitable for dose...

  18. Effect of the thin-film limit on the measurable optical properties of graphene

    Czech Academy of Sciences Publication Activity Database

    Holovský, Jakub; Nicolay, S.; De Wolf, S.; Ballif, C.

    2015-01-01

    Roč. 5, Oct (2015), s. 15684 ISSN 2045-2322 R&D Projects: GA ČR(CZ) GA14-05053S Institutional support: RVO:68378271 Keywords : graphene * thin-film limit Subject RIV: BH - Optics, Masers, Lasers Impact factor: 5.228, year: 2015

  19. Determination of radial profile of ICF hot spot's state by multi-objective parameters optimization

    International Nuclear Information System (INIS)

    Dong Jianjun; Deng Bo; Cao Zhurong; Ding Yongkun; Jiang Shaoen

    2014-01-01

    A method using multi-objective parameters optimization is presented to determine the radial profile of hot spot temperature and density. And a parameter space which contain five variables: the temperatures at center and the interface of fuel and remain ablator, the maximum model density of remain ablator, the mass ratio of remain ablator to initial ablator and the position of interface between fuel and the remain ablator, is used to described the hot spot radial temperature and density. Two objective functions are set as the variances of normalized intensity profile from experiment X-ray images and the theory calculation. Another objective function is set as the variance of experiment average temperature of hot spot and the average temperature calculated by theoretical model. The optimized parameters are obtained by multi-objective genetic algorithm searching for the five dimension parameter space, thereby the optimized radial temperature and density profiles can be determined. The radial temperature and density profiles of hot spot by experiment data measured by KB microscope cooperating with X-ray film are presented. It is observed that the temperature profile is strongly correlated to the objective functions. (authors)

  20. In-situ stress measurement of single and multilayer thin-films used in x-ray astronomy optics applications

    Science.gov (United States)

    Broadway, David M.; Ramsey, Brian D.; O'Dell, Stephen L.; Gurgew, Danielle

    2017-09-01

    We present in-situ stress measurement results for single and multilayer thin-films deposited by magnetron sputtering. In particular, we report on the influence of the material interfaces on the ensuing stress in both the transient and steady-state regimes of film growth. This behavior is used to determine the appropriate thicknesses of the constituent layers that will result in a net tensile stress in multilayers composed of various material combinations. These multilayers can then be used to compensate the compressive integrated stress in single and multilayer EUV and x-ray optical coatings. The use of multilayers to compensate the integrated stress might be advantageous because, unlike single layers of chromium, the roughness is not expected to increase with the total thickness of the multilayer. In this paper, we demonstrate the technique for W/Si and Mo/Si multilayers and discuss its application to other material combinations.

  1. On the evolution of antiferromagnetic nanodomains in NiO thin films: A LEEM study

    Science.gov (United States)

    Das, Jayanta; Menon, Krishnakumar S. R.

    2018-03-01

    Fractional order (1/2, 0) spots appear in the electron diffraction from NiO/Ag(0 0 1) films due to exchange scattering of low energy electrons by the antiferromagnetically ordered surface Ni moments. Utilizing these beams, imaging of the nanosized surface magnetic domains were carried out employing the high spatial resolution (∼ 10 nm) of the Low Energy Electron Microscopy (LEEM) in the dark-field (DF) mode. While selected through a contrast aperture, the four magnetic reflections produced by the p (2 × 2) antiferromagnetic sub-lattice lead to the visualization of the different magnetic twin domains. The intensity variations of different twin domains were measured as a function of electron beam energies via domain resolved LEEM I-V plots. The surface Néel temperatures (TN) of the films were measured using the temperature dependence of these half-order spot intensities. Detailed morphological studies of the size and shape of these nanodomains and their evolution as a function of the film thickness have been carried out with the help of pair-correlation function and fractal analysis. The size, shape and distribution of these magnetic domains are modified significantly by the strain relaxation mechanism beyond the critical film thickness. A method to estimate the relative domain sizes from a quantitative measure of the half-order spot intensities is manifested well below TN .

  2. Oxygen surface exchange kinetics measurement by simultaneous optical transmission relaxation and impedance spectroscopy: Sr(Ti,Fe)O3-x thin film case study

    Science.gov (United States)

    Perry, Nicola H.; Kim, Jae Jin; Tuller, Harry L.

    2018-01-01

    Abstract We compare approaches to measure oxygen surface exchange kinetics, by simultaneous optical transmission relaxation (OTR) and AC-impedance spectroscopy (AC-IS), on the same mixed conducting SrTi0.65Fe0.35O3-x film. Surface exchange coefficients were evaluated as a function of oxygen activity in the film, controlled by gas partial pressure and/or DC bias applied across the ionically conducting yttria-stabilized zirconia substrate. Changes in measured light transmission through the film over time (relaxations) resulted from optical absorption changes in the film corresponding to changes in its oxygen and oxidized Fe (~Fe4+) concentrations; such relaxation profiles were successfully described by the equation for surface exchange-limited kinetics appropriate for the film geometry. The kchem values obtained by OTR were significantly lower than the AC-IS derived kchem values and kq values multiplied by the thermodynamic factor (bulk or thin film), suggesting a possible enhancement in k by the metal current collectors (Pt, Au). Long-term degradation in kchem and kq values obtained by AC-IS was also attributed to deterioration of the porous Pt current collector, while no significant degradation was observed in the optically derived kchem values. The results suggest that, while the current collector might influence measurements by AC-IS, the OTR method offers a continuous, in situ, and contact-free method to measure oxygen exchange kinetics at the native surfaces of thin films. PMID:29511391

  3. Advances in spot curing technology

    International Nuclear Information System (INIS)

    Burga, R.

    1999-01-01

    A brief review of spot curing technology was presented. The process which a spot of energy of a specific wavelength bandwidth and irradiance is used to cause a coating, encapsulant or adhesive to change from a liquid to a solid state

  4. A simple assay of paracetamol based on dried blood spot suitable ...

    African Journals Online (AJOL)

    Dried blood spots in Guthrie cards are a reliable means of blood sampling suitable for pharmacoki-netic analysis in children. The aim of this study was to develop a simple and reliable bioanalytical method to measure the concentration of paracetamol in dried blood spots. Paracetamol was ex-tracted from dry blood spots by ...

  5. Thickness measurement of soft thin films on periodically patterned magnetic substrates by phase difference magnetic force microscopy.

    Science.gov (United States)

    Passeri, D; Dong, C; Angeloni, L; Pantanella, F; Natalizi, T; Berlutti, F; Marianecci, C; Ciccarello, F; Rossi, M

    2014-01-01

    The need for accurate measurement of the thickness of soft thin films is continuously encouraging the development of techniques suitable for this purpose. We propose a method through which the thickness of the film is deduced from the quantitative measurement of the contrast in the phase images of the sample surface acquired by magnetic force microscopy, provided that the film is deposited on a periodically patterned magnetic substrate. The technique is demonstrated by means of magnetic substrates obtained from standard floppy disks. Colonies of Staphylococcus aureus adherent to such substrates were used to obtain soft layers with limited lateral (a few microns) and vertical (hundreds of nanometers) size. The technique is described and its specific merits, limitations and potentialities in terms of accuracy and measurable thickness range are discussed. These parameters depend on the characteristics of the sensing tip/cantilever as well as of the substrates, the latter in terms of spatial period and homogeneity of the magnetic domains. In particular, with the substrates used in this work we evaluated an uncertainty of about 10%, a limit of detection of 50-100 nm and an upper detection limit (maximum measurable thickness) of 1 μm, all obtained with standard lift height values (50-100 nm). Nonetheless, these parameters can be easily optimized by selecting/realizing substrates with suitable spacing and homogeneity of the magnetic domains. For example, the upper detection limit can be increased up to 25-50 μm while the limit of detection can be reduced to a few tens of nanometers or a few nanometers. © 2013 Elsevier B.V. All rights reserved.

  6. Extraction of lateral eigenmode properties in thin film bulk acoustic wave resonator from interferometric measurements

    OpenAIRE

    Kokkonen, Kimmo; Pensala, Tuomas; Meltaus, Johanna; Kaivola, Matti

    2010-01-01

    A heterodyne laser interferometer is used to study acoustic wave fields excited in a 1.8 GHz AlN thin film bulk acoustic waveresonator. The electrical response of the resonator exhibits a strong thickness resonance onto which spurious modes, caused by lateral standing plate waves, are superposed. Optical interferometermeasurements are used to extract dispersion curves of the laterally propagating waves responsible for the spurious responses. A discrete eigenmode spectrum due to the finite lat...

  7. Light trapping in thin-film solar cells measured by Raman spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Ledinský, Martin; Moulin, E.; Bugnon, G.; Ganzerová, Kristína; Vetushka, Aliaksi; Meillaud, F.; Fejfar, Antonín; Ballif, C.

    2014-01-01

    Roč. 105, č. 11 (2014), "111106-1"-"111106-4" ISSN 0003-6951 R&D Projects: GA ČR GA14-15357S; GA MŠk(CZ) LM2011026; GA MŠk 7E12029 EU Projects: European Commission(XE) 283501 - FAST TRACK Institutional support: RVO:68378271 Keywords : light trapping * microcrystalline silicon * thin film solar cell * Raman spectroscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.302, year: 2014

  8. Analysis of critical state response in thin films by AC susceptibility measurements

    Czech Academy of Sciences Publication Activity Database

    Youssef, A.; Švindrych, Z.; Hadač, J.; Janů, Zdeněk

    2008-01-01

    Roč. 18, č. 2 (2008), s. 1589-1592 ISSN 1051-8223 R&D Projects: GA ČR GA102/05/0942 Institutional research plan: CEZ:AV0Z10100520 Keywords : AC susceptibility * critical state * harmonics * thin film * axial magnetic-field * superconductor disks * cylinders Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.919, year: 2008

  9. Verification of absorbed dose rates in reference beta radiation fields: measurements with an extrapolation chamber and radiochromic film

    Energy Technology Data Exchange (ETDEWEB)

    Reynaldo, S. R. [Development Centre of Nuclear Technology, Posgraduate Course in Science and Technology of Radiations, Minerals and Materials / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil); Benavente C, J. A.; Da Silva, T. A., E-mail: sirr@cdtn.br [Development Centre of Nuclear Technology / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Belo Horizonte, Minas Gerais (Brazil)

    2015-10-15

    Beta Secondary Standard 2 (Bss 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, metrology laboratories are required to verify the reliability of the Bss-2 system by performing additional verification measurements. In the CDTN Calibration Laboratory, the absorbed dose rates and their angular variation in the {sup 90}Sr/{sup 90}Y and {sup 85}Kr beta radiation fields were studied. Measurements were done with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. In comparison to the certificate values provided by the Bss-2, absorbed dose rates measured with the extrapolation chamber differed from -1.4 to 2.9% for the {sup 90}Sr/{sup 90}Y and -0.3% for the {sup 85}Kr fields; their angular variation showed differences lower than 2% for incidence angles up to 40-degrees and it reached 11% for higher angles, when compared to ISO values. Measurements with the radiochromic film showed an asymmetry of the radiation field that is caused by a misalignment. Differences between the angular variations of absorbed dose rates determined by both dosimetry systems suggested that some correction factors for the extrapolation chamber that were not considered should be determined. (Author)

  10. Dynamic Optoelectronic Properties in Perovskite Oxide Thin Films Measured with Ultrafast Transient Absorption & Reflectance Spectroscopy

    Science.gov (United States)

    Smolin, Sergey Y.

    -derived static spectra of LaFeO3, we find that thermal contributions dominate the transient absorption and reflectance spectra above the band gap. A transient photoinduced absorption feature below the band gap at 1.9 eV is not reproduced in the thermally derived spectra and has significantly longer decay kinetics from the thermallyinduced features; therefore, this long lived photoinduced absorption is likely derived, at least partially, from photoexcited carriers with lifetimes much longer than 3 nanoseconds. LaFeO3 has a wide band gap of 2.4 eV but its absorption can be decreased with chemical substitution of Sr for Fe to make it more suitable for various applications. This type of A-site substitution is a common route to change static optical absorption in perovskite oxides, but there are no systematic studies looking at how A-site substitution changes dynamic optoelectronic properties. To understand the relationship between composition and static and dynamic optical properties we worked with the model system of La1-xSrxFeO 3-delta epitaxial films grown on LSAT, uncovering the effects of A-site cation substitution and oxygen stoichiometry. Variable-angle spectroscopic ellipsometry was used to measure static optical properties, revealing a linear increase in absorption coefficient at 1.25 eV and a red-shifting of the optical absorption edge with increasing Sr fraction. The absorption spectra can be similarly tuned through the introduction of oxygen vacancies, indicating the critical role that nominal Fe valence plays in optical absorption. Dynamic optoelectronic properties were studied with ultrafast transient reflectance spectroscopy with broadband visible (1.6 eV to 4 eV) and near-infrared (0.9 eV to 1.5 eV) probes. The sign of the reflectance change in the near-infrared region in LSFO is indicative of carrier bandfilling of newly created electronic states by photoexcited carriers. Moreover, we find that similar transient spectral trends can be induced with A

  11. Relative SHG measurements of metal thin films: Gold, silver, aluminum, cobalt, chromium, germanium, nickel, antimony, titanium, titanium nitride, tungsten, zinc, silicon and indium tin oxide

    Directory of Open Access Journals (Sweden)

    Franklin Che

    Full Text Available We have experimentally measured the surface second-harmonic generation (SHG of sputtered gold, silver, aluminum, zinc, tungsten, copper, titanium, cobalt, nickel, chromium, germanium, antimony, titanium nitride, silicon and indium tin oxide thin films. The second-harmonic response was measured in reflection using a 150 fs p-polarized laser pulse at 1561 nm. We present a clear comparison of the SHG intensity of these films relative to each other. Our measured relative intensities compare favorably with the relative intensities of metals with published data. We also report for the first time to our knowledge the surface SHG intensity of tungsten and antimony relative to that of well known metallic thin films such as gold and silver. Keywords: Surface second-harmonic generation, Nonlinear optics, Metal thin films

  12. Towards safer roads : non-technical measures to improve road safety. Paper presented at the seminar `Black spots' in Wisla, Poland, April, 15-20, 1996.

    NARCIS (Netherlands)

    Goldenbeld, C. & Noordzij, P.C.

    1996-01-01

    This paper discusses engineering, education and enforcement in relation to hazardous road situations. If a high risk road or road site has been identified, the question is which selection of technical and non-technical measures should be taken to prevent or reduce the danger. The main argument is

  13. Objective measurement of intraocular forward light scatter using Hartmann-Shack spot patterns from clinical aberrometers. Model-eye and human-eye study.

    Science.gov (United States)

    Cerviño, Alejandro; Bansal, Dheeraj; Hosking, Sarah L; Montés-Micó, Robert

    2008-07-01

    To apply software-based image-analysis tools to objectively determine intraocular scatter determined from clinically derived Hartmann-Shack patterns. Aston Academy of Life Sciences, Aston University, Birmingham, United Kingdom, and Department of Optics, University of Valencia, Valencia, Spain. Purpose-designed image-analysis software was used to quantify scatter from centroid patterns obtained using a clinical Hartmann-Shack analyzer (WASCA, Zeiss/Meditec). Three scatter values, as the maximum standard deviation within a lenslet for all lenslets in the pattern, were obtained in 6 model eyes and 10 human eyes. In the model-eye sample, patterns were obtained in 4 sessions: 2 without realigning between measurements, 1 with realignment, and 1 with an angular shift of 6 degrees from the instrument axis. Three measurements were made in the human eyes with the C-Quant straylight meter (Oculus) to obtain psychometric and objective measures of retinal straylight. Analysis of variance, intraclass correlation coefficients, coefficient of repeatability (CoR), and correlations were used to determine intrasession and intersession repeatability and the relationship between measures. No significant differences were found between the sessions in the model eye (P=.234). The mean CoR was less than 10% in all model- and human-eye sessions. After incomplete patterns were removed, good correlation was achieved between psychometric and objective scatter measurements despite the small sample size (n=6; r=-0.831; P=.040). The methodology was repeatable in model and human eyes, strong against realignment and misalignment, and sensitive. Clinical application would benefit from effective use of the sensor's dynamic range.

  14. Pull-test adhesion measurements of diamondlike carbon films on silicon carbide, silicon nitride, aluminum oxide, and zirconium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Erck, R.A.; Nichols, F.A. [Argonne National Lab., IL (United States); Dierks, J.F. [North Dakota State Univ., Fargo, ND (United States)

    1993-10-01

    Hydrogenated amorphous carbon films or diamondlike carbon (DLC) films were formed by ion-beam deposition of 400 eV methane (CH{sub 4}) ions on several smooth and rough ceramics, as well as on ceramics coated with a layer of Si and Ti. Adhesion was measured by the pin-pull method. Excellent adhesion was measured for smooth SiC and Si{sub 3}N{sub 4}, but adhesion of DLC to Al{sub 2}O{sub 3} and ZrO{sub 2} was negligible. The use of a Si bonding interlayer produced good adhesion to all the substrates, but a Ti layer was ineffective because bonding between the DLC film and Ti was poor. The presence of surface roughness appeared to greatly increase the measured adhesion in all cases. Bulk thermodynamic calculations are not directly applicable to bonding at the interface. If the standard enthalpy of formation for reaction between CH{sub 4} and substrate is calculated assumpting a carbide or carbon phase is produced, a relation is seen between reaction enthalpy and relative adhesion. Large positive enthalpies are associated with poor adhesion; negative or small positive enthalpies are associated with good adhesion. This relation between enthalpy and adhesion was also observed for DLC deposited on Si. Lack of adhesion to Ti was attributed to inadvertent formation of a surface oxide layer that rendered the enthalpy for reaction with CH{sub 4} strongly positive and similar in magnitude to that for Al{sub 2}O{sub 3} and ZrO{sub 2}.

  15. Residual stress measurments of chromium films by x-ray diffraction, the sin/sup 2/psi method

    Energy Technology Data Exchange (ETDEWEB)

    Wong, S.M.

    1978-01-01

    Residual stresses on chromium films vacuum deposited by electron beam on beryllium substrates were measured by x-ray diffraction. The minute peak shift of the diffraction profile reveals the presence of strain, hence stress. Shift detection was made possible by fitting experimental data to a modified Lorentz function and then subjecting the fit to a regression analysis. Computer aid was utilized extensively. Stresses, both tensile and compressive, and of magnitude between 10/sup 9/ to 10/sup 10/ dynes cm/sup -2/ were found for substrate temperatures in the range of 300 to 550/sup 0/C.

  16. Thermal imaging of hot spots in nanostructured microstripes

    Energy Technology Data Exchange (ETDEWEB)

    Saidi, E; Lesueur, J; Aigouy, L [LPEM, CNRS UPR5, ESPCI, 10 rue Vauquelin, 75231 Paris Cedex 5 (France); Labeguerie-Egea, J; Mortier, M, E-mail: lionel.aigouy@espci.f [LCMCP, CNRS UMR 7574, ENSCP, 11 rue P. et M. Curie, 75005 Paris (France)

    2010-03-01

    By scanning thermal microscopy, we study the behavior of nanostructured metallic microstripes heated by Joule effect. Regularly spaced indentations have been made along the thin film stripe in order to create hot spots. For the designed stripe geometry, we observe that heat remains confined in the wire and in particular at shrinkage points within {approx}1{mu}m{sup 2}. Thermal maps have been obtained with a good lateral resolution (< 300nm) and a good temperature sensitivity ({approx}1K).

  17. SU-F-T-169: A Periodic Quality Assurance Program for a Spot-Scanning Proton Treatment Facility

    Energy Technology Data Exchange (ETDEWEB)

    Mundy, D; Tryggestad, E; Beltran, C; Furutani, K; Gilson, G; Ito, S; Johnson, J; Kruse, J; Remmes, N; Tasson, A; Whitaker, T; Herman, M [Mayo Clinic, Rochester, MN (United States)

    2016-06-15

    Purpose: To develop daily and monthly quality assurance (QA) programs in support of a new spot-scanning proton treatment facility using a combination of commercial and custom equipment and software. Emphasis was placed on efficiency and evaluation of key quality parameters. Methods: The daily QA program was developed to test output, spot size and position, proton beam energy, and image guidance using the Sun Nuclear Corporation rf-DQA™3 device and Atlas QA software. The program utilizes standard Atlas linear accelerator tests repurposed for proton measurements and a custom jig for indexing the device to the treatment couch. The monthly QA program was designed to test mechanical performance, image quality, radiation quality, isocenter coincidence, and safety features. Many of these tests are similar to linear accelerator QA counterparts, but many require customized test design and equipment. Coincidence of imaging, laser marker, mechanical, and radiation isocenters, for instance, is verified using a custom film-based device devised and manufactured at our facility. Proton spot size and position as a function of energy are verified using a custom spot pattern incident on film and analysis software developed in-house. More details concerning the equipment and software developed for monthly QA are included in the supporting document. Thresholds for daily and monthly tests were established via perturbation analysis, early experience, and/or proton system specifications and associated acceptance test results. Results: The periodic QA program described here has been in effect for approximately 9 months and has proven efficient and sensitive to sub-clinical variations in treatment delivery characteristics. Conclusion: Tools and professional guidelines for periodic proton system QA are not as well developed as their photon and electron counterparts. The program described here efficiently evaluates key quality parameters and, while specific to the needs of our facility

  18. SU-F-T-169: A Periodic Quality Assurance Program for a Spot-Scanning Proton Treatment Facility

    International Nuclear Information System (INIS)

    Mundy, D; Tryggestad, E; Beltran, C; Furutani, K; Gilson, G; Ito, S; Johnson, J; Kruse, J; Remmes, N; Tasson, A; Whitaker, T; Herman, M

    2016-01-01

    Purpose: To develop daily and monthly quality assurance (QA) programs in support of a new spot-scanning proton treatment facility using a combination of commercial and custom equipment and software. Emphasis was placed on efficiency and evaluation of key quality parameters. Methods: The daily QA program was developed to test output, spot size and position, proton beam energy, and image guidance using the Sun Nuclear Corporation rf-DQA™3 device and Atlas QA software. The program utilizes standard Atlas linear accelerator tests repurposed for proton measurements and a custom jig for indexing the device to the treatment couch. The monthly QA program was designed to test mechanical performance, image quality, radiation quality, isocenter coincidence, and safety features. Many of these tests are similar to linear accelerator QA counterparts, but many require customized test design and equipment. Coincidence of imaging, laser marker, mechanical, and radiation isocenters, for instance, is verified using a custom film-based device devised and manufactured at our facility. Proton spot size and position as a function of energy are verified using a custom spot pattern incident on film and analysis software developed in-house. More details concerning the equipment and software developed for monthly QA are included in the supporting document. Thresholds for daily and monthly tests were established via perturbation analysis, early experience, and/or proton system specifications and associated acceptance test results. Results: The periodic QA program described here has been in effect for approximately 9 months and has proven efficient and sensitive to sub-clinical variations in treatment delivery characteristics. Conclusion: Tools and professional guidelines for periodic proton system QA are not as well developed as their photon and electron counterparts. The program described here efficiently evaluates key quality parameters and, while specific to the needs of our facility

  19. Spot Welding of Honeycomb Structures

    Science.gov (United States)

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  20. Development of procedures for performance measurements and lifetime testing of thin film photovoltaic devices

    OpenAIRE

    Roschier, Solveig

    2002-01-01

    In this work single junction a-Si, CdTe and CIGS modules and prototype modules and mini-modules were investigated to reliably be able to characterize these technologies for electrical performance and to find out potential failure mechanisms in accelerated lifetime testing. Thin film modules may increase their share of the market in the future. A-Si modules have been manufactured already for several years and CdTe and CIGS modules are shortly entering the market. However, there is a lack of ch...

  1. Local photoconductivity of microcrystalline silicon thin films measured by conductive atomic force microscopy

    Czech Academy of Sciences Publication Activity Database

    Ledinský, Martin; Fejfar, Antonín; Vetushka, Aliaksi; Stuchlík, Jiří; Rezek, Bohuslav; Kočka, Jan

    2011-01-01

    Roč. 5, 10-11 (2011), s. 373-375 ISSN 1862-6254 R&D Projects: GA MŠk(CZ) LC06040; GA MŠk(CZ) MEB061012; GA AV ČR KAN400100701; GA MŠk LC510 EU Projects: European Commission(XE) 240826 - PolySiMode Institutional research plan: CEZ:AV0Z10100521 Keywords : amorphous silicon * nanocrystalline silicon * thin films * atomic force microscopy * photoconductivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.218, year: 2011

  2. Measurement of oil film thickness and friction force on a guide shoe bearing

    DEFF Research Database (Denmark)

    Vølund, Anders

    2002-01-01

    An experimental program was carried out in order to reveal oil film thickness, and friction force of the guide shoe bearing of a large two stroke marine diesel engine. The experiment was conducted on a full size engine located at the research facility at MAN B&W Diesel A/S. The experiment...... was conducted such that the influence from the experiment on the characteristics were as small as possible. The objective of the experiment was to determine the frictional loss of this bearing and to check whether a suggested numerical model was applicable or not. Some future aspects for this bearing...

  3. MCNP modelling of vaginal and uterine applicators used in intracavitary brachytherapy and comparison with radiochromic film measurements

    Science.gov (United States)

    Ceccolini, E.; Gerardy, I.; Ródenas, J.; van Dycke, M.; Gallardo, S.; Mostacci, D.

    Brachytherapy is an advanced cancer treatment that is minimally invasive, minimising radiation exposure to the surrounding healthy tissues. Microselectron© Nucletron devices with 192Ir source can be used for gynaecological brachytherapy, in patients with vaginal or uterine cancer. Measurements of isodose curves have been performed in a PMMA phantom and compared with Monte Carlo calculations and TPS (Plato software of Nucletron BPS 14.2) evaluation. The isodose measurements have been performed with radiochromic films (Gafchromic EBT©). The dose matrix has been obtained after digitalisation and use of a dose calibration curve obtained with a 6 MV photon beam provided by a medical linear accelerator. A comparison between the calculated and the measured matrix has been performed. The calculated dose matrix is obtained with a simulation using the MCNP5 Monte Carlo code (F4MESH tally).

  4. Meteorology of Jupiter's Equatorial Hot Spots and Plumes from Cassini

    Science.gov (United States)

    Choi, David Sanghun; Showman, Adam P.; Vasavada, Ashwin R.; Simon-Miller, Amy A.

    2013-01-01

    We present an updated analysis of Jupiter's equatorial meteorology from Cassini observations. For two months preceding the spacecraft's closest approach, the Imaging Science Subsystem (ISS) onboard regularly imaged the atmosphere. We created time-lapse movies from this period in order to analyze the dynamics of equatorial hot spots and their interactions with adjacent latitudes. Hot spots are relatively cloud-free regions that emit strongly at 5 lm; improved knowledge of these features is crucial for fully understanding Galileo probe measurements taken during its descent through one. Hot spots are quasistable, rectangular dark areas on visible-wavelength images, with defined eastern edges that sharply contrast with surrounding clouds, but diffuse western edges serving as nebulous boundaries with adjacent equatorial plumes. Hot spots exhibit significant variations in size and shape over timescales of days and weeks. Some of these changes correspond with passing vortex systems from adjacent latitudes interacting with hot spots. Strong anticyclonic gyres present to the south and southeast of the dark areas appear to circulate into hot spots. Impressive, bright white plumes occupy spaces in between hot spots. Compact cirrus-like 'scooter' clouds flow rapidly through the plumes before disappearing within the dark areas. These clouds travel at 150-200 m/s, much faster than the 100 m/s hot spot and plume drift speed. This raises the possibility that the scooter clouds may be more illustrative of the actual jet stream speed at these latitudes. Most previously published zonal wind profiles represent the drift speed of the hot spots at their latitude from pattern matching of the entire longitudinal image strip. If a downward branch of an equatorially-trapped Rossby wave controls the overall appearance of hot spots, however, the westward phase velocity of the wave leads to underestimates of the true jet stream speed.

  5. Star spotting at CERN

    CERN Multimedia

    2008-01-01

    This June, two American celebrities (and physics enthusiasts!) came to CERN. Brian Cox gave Mike Einziger (right), lead guitarist with the rock band Incubus, the star treatment in the ATLAS cavern. Jesse Dylan embraces the spirit of ATLAS! Mike Einziger, lead guitarist with the rock band Incubus, visited CERN on Friday 13 June between concerts in Finland and England. Einziger, a lifelong science enthusiast descended into the ATLAS and CMS caverns and visited the SM18 test magnet facility during his brief tour of CERN. Einziger learned about the LHC through watching online lectures from University of Manchester and ATLAS physicist Brian Cox, and was thrilled to have the chance to see the detectors in person. The musician has created an orchestral piece, inspired in part by the work being done at CERN for the LHC, which will have its debut in Los Angeles on 23 August. Just over a week earlier, Jesse Dylan, Hollywood film director a...

  6. Using Continuous In-situ Measurement of Fluorescence to Reveal Hot Spots and Hot Moments of Dissolved Organic Matter Dynamics in a Forested Watershed

    Science.gov (United States)

    Ryan, K. A.; Hosen, J. D.; Raymond, P. A.; Stubbins, A.; Shanley, J. B.

    2017-12-01

    River systems serve as net carbon exporters from land to the ocean, fueling downstream aquatic ecosystem food webs. Fluorescence signatures of aquatic organic matter can be used as a proxy for dissolved organic carbon (DOC) concentration and can characterize DOC composition, reactivity, and source to improve our understanding of ecological processes. In-situ measurement of fluorescence using fifteen-minute interval data logging allows greater temporal resolution than laboratory studies. However, in-situ data must be corrected for interferences from temperature, absorbance and turbidity changes occurring in the field. We installed multiparameter water quality sondes (Eureka Mantas) and in-situ fluorometers (Turner Designs Cyclops) at sites nested within streams and riparian zones in the Sleepers River Research Watershed in Vermont in 2017. We coupled these measurements with simultaneous intensive field sampling campaigns and laboratory analysis of DOC and fluorescence Excitation-Emission Matrices. The data loggers from the nested sites recorded fluorescence peaks responding to discharge events and tracked changes in fluorescence occurring from upstream to downstream sites. Laboratory results confirm a nonlinear, hysteretic relationship between discharge and DOC where peak DOC lags peak discharge. This hysteresis is predicted to be controlled by multiple flow paths and DOC sources (i.e. groundwater, overland flow). We conclude that continuous in-situ records of river water fluorescence can be used to inform ecological processes and test new hypotheses concerning dissolved organic matter dynamics in watersheds.

  7. Studies on the gamma-gamma method. Definition of an apparatus for on-the-spot measurement of uranium ore densities

    International Nuclear Information System (INIS)

    Czubek, J.A.; Guitton, J.

    1966-01-01

    The work described follows on to the research published in report CEA-R--2720 in march 1965. It includes: - experimental results obtained with a model composed of a constant density material (graphite); - the drawing-up of calibration curves using the similitude principle; - determination of the characteristics of a gamma-gamma probe, together with a discussion. The influence is studied of a certain number of parameters on the shape of the energy spectra of scattered radiation, and of the calibration curves: nature of the radioactive source, diameter of the probe area, source detector distance, geometrical shape of shielding between the source and the detector. An attempt is made to find a mathematical model for the calibration curve, for given conditions. Numerical applications make it possible to establish the optimum technical characteristics for a probe measuring the density with the smallest statistical error. (authors) [fr

  8. In situ electrical resistivity measurements of vanadium thin films performed in vacuum during different annealing cycles

    Science.gov (United States)

    Pedrosa, Paulo; Cote, Jean-Marc; Martin, Nicolas; Arab Pour Yazdi, Mohammad; Billard, Alain

    2017-02-01

    The present study describes a sputtering and in situ vacuum electrical resistivity setup that allows a more efficient sputtering-oxidation coupling process for the fabrication of oxide compounds like vanadium dioxide, VO2. After the sputtering deposition of pure V thin films, the proposed setup enables the sample holder to be transferred from the sputtering to the in situ annealing + resistivity chamber without venting the whole system. The thermal oxidation of the V films was studied by implementing two different temperature cycles up to 550 °C, both in air (using a different resistivity setup) and vacuum conditions. Main results show that the proposed system is able to accurately follow the different temperature setpoints, presenting clean and low-noise resistivity curves. Furthermore, it is possible to identify the formation of different vanadium oxide phases in air, taking into account the distinct temperature cycles used. The metallic-like electrical properties of the annealed coatings are maintained in vacuum whereas those heated in air produce a vanadium oxide phase mixture.

  9. Influence of thermal, morphological and measuring variables on the thermal runaway of superconducting films under high current densities

    International Nuclear Information System (INIS)

    Ferro, G; Maza, J; Ramallo, M V; Veira, J A; Vidal, F

    2009-01-01

    We study the abrupt jump in voltage seen in the current-voltage characteristics of high-T c films at current densities, J*, around 2-3 times the critical one, and for perturbations with characteristic times in the millisecond range. Customarily, even for these long characteristic times, the voltage jump has been ascribed to an electrodynamic vortex instability. Recent results based on finite-element analyses show quantitatively that smooth, i.e., jumpfree isothermal curves may show up themselves as the jumping, i.e., discontinuous curves experimentalists observe, once the nonlinearity, thermal feedback and measurement rate are properly accounted for. The thermal nature of the transition to a highly dissipative state in high-T c superconductors at zero magnetic field makes the control of the instability transition easier in that there are more parameters available to experimentalists that may be tuned to tailor the phenomenon. This is specially relevant for devices working on their superconducting borderline as current-limiters or even magnets. Here we explore through finite-element analysis the role of film geometry, measurement rate and substrate thermal conductivity in the triggering of the thermal runaway.

  10. Fuel film thickness measurements using refractive index matching in a stratified-charge SI engine operated on E30 and alkylate fuels

    Science.gov (United States)

    Ding, Carl-Philipp; Sjöberg, Magnus; Vuilleumier, David; Reuss, David L.; He, Xu; Böhm, Benjamin

    2018-03-01

    This study shows fuel film measurements in a spark-ignited direct injection engine using refractive index matching (RIM). The RIM technique is applied to measure the fuel impingement of a high research octane number gasoline fuel with 30 vol% ethanol content at two intake pressures and coolant temperatures. Measurements are conducted for an alkylate fuel at one operating case, as well. It is shown that the fuel volume on the piston surface increases for lower intake pressure and lower coolant temperature and that the alkylate fuel shows very little spray impingement. The fuel films can be linked to increased soot emissions. A detailed description of the calibration technique is provided and measurement uncertainties are discussed. The dependency of the RIM signal on refractive index changes is measured. The RIM technique provides quantitative film thickness measurements up to 0.9 µm in this engine. For thicker films, semi-quantitative results of film thickness can be utilized to study the distribution of impinged fuel.

  11. Measurement of high frequency conductivity of oxide-doped anti-ferromagnetic thin film with a near-field scanning microwave microscope

    Directory of Open Access Journals (Sweden)

    Z. Wu

    2014-04-01

    Full Text Available In this manuscript, we describe how the map of high frequency conductivity distribution of an oxide-doped anti-ferromagnetic 200 nm thin film can be obtained from the quality factor (Q measured by a near-field scanning microwave microscope (NSMM. Finite element analysis (FEA is employed to simulate the NSMM tip-sample interaction and obtain a curve related between the simulated quality factor (Q and conductivity. The curve is calibrated by a standard Cu thin film with thickness of 200 nm, together with NSMM measured Q of Ag, Au, Fe, Cr and Ti thin films. The experimental conductivity obtained by the NSMM for IrMn thin films with various doped concentrations of Al2O3 is found consistent with conventional voltammetry measurement in the same tendency. That conductivity decreases as the content of doped Al2O3 increases. The results and images obtained demonstrate that NSMM can be employed in thin film analysis for characterization of local electrical properties of materials in a non-destructive manner and for obtaining a map of conductivity distribution on the same film.

  12. Direct comparison of photoemission spectroscopy and in situ Kelvin probe work function measurements on indium tin oxide films

    International Nuclear Information System (INIS)

    Beerbom, M.M.; Laegel, B.; Cascio, A.J.; Doran, B.V.; Schlaf, R.

    2006-01-01

    The work function of commercially available indium tin oxide (ITO) films on glass substrates was measured using photoemission spectroscopy (PES) and ultra-high vacuum (UHV) Kelvin probe in direct comparison. Absolute Kelvin probe work function values were determined via calibration of the measured contact potential difference (CPD) using an in situ sputtered Au reference sample. The Kelvin probe data confirmed that ultraviolet photoemission spectroscopy (UPS) measurements change the work function of ITO surfaces previously exposed to ambient environment, when measured without in situ surface cleaning procedures. The results also demonstrate that both Kelvin probe and PES yield virtually identical work function values, as long as the Kelvin probe data are calibrated against a known standard. As a consequence, previously reported higher work function values determined with Kelvin probe as compared to values obtained with UPS on similar samples are likely related to a photochemically generated surface dipole during UPS measurements. Comparison between Kelvin probe and low intensity X-ray photoemission spectroscopy (LIXPS) work function measurements demonstrated that accurate work function measurements on ITO previously exposed to the ambient are possible with PES

  13. Analysis and validation of laser spot weld-induced distortion

    Energy Technology Data Exchange (ETDEWEB)

    Knorovsky, G.A.; Kanouff, M.P.; Maccallum, D.O.; Fuerschbach, P.W.

    1999-12-09

    Laser spot welding is an ideal process for joining small parts with tight tolerances on weld size, location, and distortion, particularly those with near-by heat sensitive features. It is also key to understanding the overlapping laser spot seam welding process. Rather than attempting to simulate the laser beam-to-part coupling (particularly if a keyhole occurs), it was measured by calorimetry. This data was then used to calculate the thermal and structural response of a laser spot welded SS304 disk using the finite element method. Five combinations of process parameter values were studied. Calculations were compared to experimental data for temperature and distortion profiles measured by thermocouples and surface profiling. Results are discussed in terms of experimental and modeling factors. The authors then suggest appropriate parameters for laser spot welding.

  14. SPS remanent radiation the warm spots

    CERN Document Server

    Billen, R

    1998-01-01

    The remanent radiation in the SPS ring is measured after each operational period. We all know very well the "hot spots" in the dedicated regions for particle injection and extraction. So far, not a lot of attention has been paid to those regions where there are clear traces of radiation, without an obvious reason. From an operational point of view, these regions might be quite important, since they could reveal a specific problem. This paper will look into those "warm spots", their location in the SPS ring and the transverse plane in which the radiation originates. Some classification of typical problem classes is made, as well as hints to the possible origins of the radiation problems.

  15. Intercomparison of absorbed dose to water measurements for 60Co gamma rays using Fricke, alanine and radiochromic dye film dosimetry

    International Nuclear Information System (INIS)

    Villarreal-Barajas, J.E.; Gonzalez-Martinez, P.R.; Urena-Nunez, F.; Martinez-Ayala, L.; Tovar-Munoz, V.M.

    2002-01-01

    Measurements of absorbed dose at 5 cm depth in a 30 x 30 x 30 cm 3 water phantom have been performed using three independent dosimetric techniques: Fricke, alanine and radiochromic dye film (GafChromic HD-810). The measurements were carried out in the secondary standard dosimetry laboratory at ININ Mexico using a collimated 60 Co gamma source with a radiation field of 10 x 10 cm 2 at the phantom front surface. The source to phantom distance was set at 100 cm. The reference absorbed dose at 5 cm depth in the water phantom was obtained using a 0.6 cm 3 ionisation chamber. The absorbed dose to water for the test dosimetry techniques was around 100 Gy. The deviations of the dose obtained from these dosimetry techniques were within 4%. The reasons for these deviations are discussed. (author)

  16. Note: Calibration of EBT3 radiochromic film for measuring solar ultraviolet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Chun, S. L. [Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong (Hong Kong); Yu, P. K. N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Kowloon Tong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong, Kowloon Tong (Hong Kong)

    2014-10-01

    Solar (UVA + UVB) exposure was assessed using the Gafchromic EBT3 film. The coloration change was represented by the net reflective optical density (Net ROD). Through calibrations against a UV-tube lamp, operational relationships were obtained between Net ROD and the (UVA + UVB) exposures (in J cm⁻²p or J m⁻²). The useful range was from ~0.2 to ~30 J cm⁻². The uniformity of UV irradiation was crucial for an accurate calibration. For solar exposures ranging from 2 to 11 J cm⁻², the predicted Net ROD agreed with the recorded values within 9%, while the predicted exposures agreed with the recorded values within 15%.

  17. Third sound measurements of superfluid 4He films on multiwall carbon nanotubes below 1 K

    International Nuclear Information System (INIS)

    Menachekanian, Emin; Abraham, John B S; Chen, Bob; Iaia, Vito; Li, Andrew; Williams, Gary A

    2014-01-01

    Third sound is studied for superfluid films of 4He adsorbed on multiwall carbon nanotubes packed into an annular resonator. The third sound is generated with mechanical oscillation of the cell, and detected with carbon bolometers. A filling curve at temperatures near 250 mK shows oscillations in the third sound velocity, with maxima at the completion of the 4th and 5th atomic layers. Sharp changes in the Q factor of the third sound are found at partial layer fillings. Temperature sweeps at a number of fill points show strong broadening effects on the Kosterlitz-Thouless (KT) transition, and rapidly increasing dissipation, in qualitative agreement with the predictions of Machta and Guyer. At the 4th layer completion there is a sudden reduction of the transition temperature T KT , and then a recovery back to linear variation with temperature, although the slope is considerably smaller than the KT prediction

  18. Structure of ultrathin films of Co on Cu(111) from normal-incidence x-ray standing wave and medium-energy ion scattering measurements

    International Nuclear Information System (INIS)

    Butterfield, M.T.; Crapper, M.D.; Noakes, T.C.Q.; Bailey, P.; Jackson, G.J.; Woodruff, D.P.

    2000-01-01

    Applications of the techniques of normal-incidence x-ray standing wave (NIXSW) and medium-energy ion scattering (MEIS) to the elucidation of the structure of an ultrathin metallic film, Co on Cu(111), are reported. NIXSW and MEIS are shown to yield valuable and complementary information on the structure of such systems, yielding both the local stacking sequence and the global site distribution. For the thinnest films of nominally two layers, the first layer is of entirely fcc registry with respect to the substrate, but in the outermost layer there is significant occupation of hcp local sites. For films up to 8 monolayers (ML) thick, the interlayer spacing of the Co layers is 0.058±0.006 Aa smaller than the Cu substrate (111) layer spacing. With increasing coverage, the coherent fraction of the (1(bar sign)11) NIXSW decreases rapidly, indicating that the film does not grow in a fcc continuation beyond two layers. For films in this thickness range, hcp-type stacking dominates fcc twinning by a ratio of 2:1. The variation of the (1(bar sign)11) NIXSW coherent fraction with thickness shows that the twinning occurs close to the Co/Cu interface. For thicker films of around 20 ML deposited at room temperature, medium-energy ion scattering measurements reveal a largely disordered structure. Upon annealing to 300 deg. C the 20-ML films order into a hcp structure

  19. Antimicrobial and cell viability measurement of bovine serum albumin capped silver nanoparticles (Ag/BSA) loaded collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film.

    Science.gov (United States)

    Bakare, Rotimi; Hawthrone, Samantha; Vails, Carmen; Gugssa, Ayele; Karim, Alamgir; Stubbs, John; Raghavan, Dharmaraj

    2016-03-01

    Bacterial infection of orthopedic devices has been a major concern in joint replacement procedures. Therefore, this study is aimed at formulating collagen immobilized poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) film loaded with bovine serum albumin capped silver nanoparticles (Ag/BSA NPs) to inhibit bacterial growth while retaining/promoting osteoblast cells viability. The nanoparticles loaded collagen immobilized PHBV film was characterized for its composition by X-ray Photoelectron Spectroscopy and Anodic Stripping Voltammetry. The extent of loading of Ag/BSA NPs on collagen immobilized PHBV film was found to depend on the chemistry of the functionalized PHBV film and the concentration of Ag/BSA NPs solution used for loading nanoparticles. Our results showed that more Ag/BSA NPs were loaded on higher molecular weight collagen immobilized PHEMA-g-PHBV film. Maximum loading of Ag/BSA NPs on collagen immobilized PHBV film was observed when 16ppm solution was used for adsorption studies. Colony forming unit and optical density measurements showed broad antimicrobial activity towards Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa at significantly lower concentration i.e., 0.19 and 0.31μg/disc, compared to gentamicin and sulfamethoxazole trimethoprim while MTT assay showed that released nanoparticles from Ag/BSA NPs loaded collagen immobilized PHBV film has no impact on MCTC3-E1 cells viability. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Measuring theory of mind across middle childhood: Reliability and validity of the Silent Films and Strange Stories tasks.

    Science.gov (United States)

    Devine, Rory T; Hughes, Claire

    2016-09-01

    Recent years have seen a growth of research on the development of children's ability to reason about others' mental states (or "theory of mind") beyond the narrow confines of the preschool period. The overall aim of this study was to investigate the psychometric properties of a task battery composed of items from Happé's Strange Stories task and Devine and Hughes' Silent Film task. A sample of 460 ethnically and socially diverse children (211 boys) between 7 and 13years of age completed the task battery at two time points separated by 1month. The Strange Stories and Silent Film tasks were strongly correlated even when verbal ability and narrative comprehension were taken into account, and all items loaded onto a single theory-of-mind latent factor. The theory-of-mind latent factor provided reliable estimates of performance across a wide range of theory-of-mind ability and showed no evidence of differential item functioning across gender, ethnicity, or socioeconomic status. The theory-of-mind latent factor also exhibited strong 1-month test-retest reliability, and this stability did not vary as a function of child characteristics. Taken together, these findings provide evidence for the validity and reliability of the Strange Stories and Silent Film task battery as a measure of individual differences in theory of mind suitable for use across middle childhood. We consider the methodological and conceptual implications of these findings for research on theory of mind beyond the preschool years. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Quartz crystal microbalance and spectroscopy measurements for acid doping in polyaniline films

    Directory of Open Access Journals (Sweden)

    Mohamad M Ayad and Eman A Zaki

    2008-01-01

    Full Text Available We investigated the doping of thin polyaniline (PANI films, prepared by the chemical oxidation of aniline, with different acids. The initial step in the investigation is the preparation of PANI films from aqueous hydrochloric acid solution. This is followed by dedoping with ammonia to obtain a PANI base, which is subsequently doped with strong acids (e.g. hydrochloric, sulfuric, phosphoric and trichloroacetic acids and with a weak acid (acetic acid. The dopant weight fraction (w, which is connected with the gain of mass during the doping of PANI, was determined in situ using a quartz crystal microbalance (QCM. The behavior of PANI upon doping with different anions derived from strong acids indicates that both proton and the anion uptake into the polymer chains occur sharply, rapidly, completely, and reversibly. However the uptake in the case in acetic acid is characterized by slow diffusion. The doping was studied at different concentrations of acetic acid. A second cycle of dedoping–redoping was also performed. The kinetics of the doping reaction is dominated by Fickian diffusion kinetics. The diffusion coefficients (D of the dopant ions into the PANI chains were determined using the QCM and by UV–Vis absorption spectroscopy in the range of (0.076–1.64× 10−15 cm2 s−1. It was found that D in the second cycle of doping is larger than that evaluated from the first cycle of doping for high concentrations of acetic acid. D for the diffusion and for the dopant ion expulsion from the PANI chains was also determined during the redoping process. It was found that D for acetic acid ions in the doping process is larger than that calculated for the dedoping process.

  2. Measurement of critical current density of YBCO film by a mutual inductive method using a drive coil with a sharp iron core

    International Nuclear Information System (INIS)

    Yamada, H.; Bitoh, A.; Mitsuno, Y.; Imai, I.; Nomura, K.; Kanayama, K.; Nakagawa, S.; Mawatari, Y.; Yamasaki, H.

    2005-01-01

    Recent developments in high-temperature superconductors have facilitated the production of high critical current and large-area films by the PLD method or MOD method. Nondestructive measurement techniques for high quality films are of great importance to estimate superconducting properties, such as the critical current density, J C . The inductive method using the third-harmonic voltage component, V 3 , is a promising technique for the measurement of the properties of J C . On inductive determination of J C for high-J C thin films and thicker films (thickness d ≥ 0.1 mm), the drive coil must generate a magnetic field sufficiently large to break the complete field shielding of the film. Therefore, we investigated a mutual inductance technique using a drive coil with a sharp ferromagnetic core for investigation of the J C of the PLD-YBCO film. As a result, an abrupt nonlinear increase in the voltage across the pick-up coil was detected after magnetic full penetration of the film, and the threshold of the drive current I th was suppressed to 0.23-0.28 times as compared with that measured by the inductive method using the third-harmonic voltage, V 3 . FEM analysis indicated the diameter of the excitation field region to be 0.6 mm in the case of a 0.4 mm φ iron core. The E-J characters measured by the mutual inductive method as a function of frequency agreed well with those measured by the inductive method using V 3

  3. 9 CFR 149.4 - Spot audit.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random spot...

  4. Magnetic field and temperature dependent measurements of hall coefficient in thermal evaporated Tin-Doped Cadmium Oxide Thin films

    International Nuclear Information System (INIS)

    Hamadi, O.; Shakir, N.; Mohammed, F.

    2010-01-01

    CdO:Sn thin films are deposited onto glass substrates by thermal evaporation under vacuum. The studied films are polycrystalline and have an NaCl structure. The Hall effect is studied for films with different thickness as substrates are maintained at different temperatures. The temperature dependence of the Hall mobility is also investigated. (authors)

  5. High fluence deposition of polyethylene glycol films at 1064 nm by matrix assisted pulsed laser evaporation (MAPLE)

    International Nuclear Information System (INIS)

    Purice, A.; Schou, J.; Kingshott, P.; Pryds, N.; Dinescu, M.

    2007-01-01

    Matrix assisted pulsed laser evaporation (MAPLE) has been applied for deposition of thin polyethylene glycol (PEG) films with infrared laser light at 1064 nm. We have irradiated frozen targets (of 1 wt.% PEG dissolved in water) and measured the deposition rate in situ with a quartz crystal microbalance. The laser fluence needed to produce PEG films turned out to be unexpectedly high with a threshold of 9 J/cm 2 , and the deposition rate was much lower than that with laser light at 355 nm. Results from matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis demonstrate that the chemistry, molecular weight and polydispersity of the PEG films were identical to the starting material. Studies of the film surface with scanning electron microscopy (SEM) indicate that the Si-substrate is covered by a relatively homogenous PEG film with few bare spots

  6. Oil film thickness measurement and analysis for an angular contact ball bearing operating in parched elastohydrodynamic lubrication. M.S. Thesis. Final Report

    Science.gov (United States)

    Hunter, Scott D.

    1986-01-01

    The capacitance method is used to estimate the oil film thickness in the Hertzian contact zone of an angular contact ball bearing operating in parched elastohydrodynamic lubrication. The parched elastohydrodynamic lubrication regime is characterized by a transient film thickness and basic speed ratio (ball spin rate over combined race speed) and the formation of a friction polymer. The experimental apparatus tests 40 mm 108 H ball bearings in the counter rotating race mode at loads of 200 and 300 lb, a film parameter of 1.6 and nominal inner and outer race speeds of 38 and 26 rps, respectively. Experimental results are presented for the capacitance, thickness, and conductance of the oil film as functions of elapsed time and for the basic speed ratios as a function of elapsed time, load, and amount of lubricant applied to the test bearing. Results indicate that a friction polymer formed from the initial lubricant has an effect on the capacitance and basic speed ratio measurements.

  7. Verification of the anatomy and newly discovered histology of the G-spot complex.

    Science.gov (United States)

    Ostrzenski, A; Krajewski, P; Ganjei-Azar, P; Wasiutynski, A J; Scheinberg, M N; Tarka, S; Fudalej, M

    2014-10-01

    To expand the anatomical investigations of the G-spot and to assess the G-spot's characteristic histological and immunohistochemical features. An observational study. International multicentre. Eight consecutive fresh human female cadavers. Anterior vaginal wall dissections were executed and G-spot microdissections were performed. All specimens were stained with haematoxylin and eosin (H&E). The tissues of two women were selected at random for immunohistochemical staining. The primary outcome measure was to document the anatomy of the G-spot. The secondary outcome measures were to identify the histology of the G-spot and to determine whether histological samples stained with H&E are sufficient to identify the G-spot. The anatomical existence of the G-spot was identified in all women and was in a diagonal plane. In seven (87.5%) and one (12.5%) of the women the G-spot complex was found on the left or right side, respectively. The G-spot was intimately fused with vessels, creating a complex. A large tangled vein-like vascular structure resembled an arteriovenous malformation and there were a few smaller feeding arteries. A band-like structure protruded from the tail of the G-spot. The size of the G-spot varied. Histologically, the G-spot was determined as a neurovascular complex structure. The neural component contained abundant peripheral nerve bundles and a nerve ganglion. The vascular component comprised large vein-like vessels and smaller feeding arteries. Circular and longitudinal muscles covered the G-complex. The anatomy of the G-spot complex was confirmed. The histology of the G-spot presents as neurovascular tissues with a nerve ganglion. H&E staining is sufficient for the identification of the G-spot complex. © 2014 Royal College of Obstetricians and Gynaecologists.

  8. Synchrotron based measurements of the soft x-ray performance of thin film multilayer structures

    International Nuclear Information System (INIS)

    Kania, D.R.; Bartlett, R.J.; Trela, W.J.

    1985-01-01

    Using synchrotron radiation, measuring system has been developed to test the performance of layered synthetic microstructures (LSMs) from 50 to 500 eV. The measurement techniques are reviewed, and results are compared to theoretical predictions of LSM performance

  9. On the origin of delta spots

    International Nuclear Information System (INIS)

    Tang, F.

    1983-01-01

    Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

  10. Comparison of four-probe thermal and thermoelectric transport measurements of thin films and nanostructures with microfabricated electro-thermal transducers

    Science.gov (United States)

    Kim, Jaehyun; Fleming, Evan; Zhou, Yuanyuan; Shi, Li

    2018-03-01

    Two different four-probe thermal and thermoelectric measurement methods have been reported for measuring the thermal conductivity, Seebeck coefficient, and electrical conductivity of suspended thin films and nanostructures with microfabricated electro-thermal transducers. The thermal contact resistance was extracted from the measured thermoelectric voltage drop at the contacts in the earlier four-probe method based on the assumption of constant thermal and thermoelectric properties along the sample. In comparison, the latter four-probe method can directly obtain the contact thermal resistance together with the intrinsic sample thermal resistance without making this assumption. Here, the measurement theory and data reduction processes of the latter four-probe measurement method are re-examined and improved. The measured thermal conductivity result of this improved method on representative thin film samples are found to agree with those obtained from the earlier four-probe method, which has obtained similar Seebeck coefficient and electrical conductivity as those measured with a different method for a supported thin film. The agreement provides further validation of the latest four-probe thermal transport measurement method of thin films and nanostructures.

  11. Characterization of differences in calculated and actual measured skin doses to canine limbs during stereotactic radiosurgery using Gafchromic film

    Energy Technology Data Exchange (ETDEWEB)

    Walters, Jerri [Duke Energy, York, SC (United States); Colorado State University, Fort Collins, CO (United States); Ryan, Stewart [Animal Cancer Center, Colorado State University, Fort Collins, CO (United States); Harmon, Joseph F., E-mail: joseph_harmon@bshsi.org [Bon Secours Cancer Institute, Henrico, VA (United States)

    2012-07-01

    Accurate calculation of absorbed dose to the skin, especially the superficial and radiosensitive basal cell layer, is difficult for many reasons including, but not limited to, the build-up effect of megavoltage photons, tangential beam effects, mixed energy scatter from support devices, and dose interpolation caused by a finite resolution calculation matrix. Stereotactic body radiotherapy (SBRT) has been developed as an alternative limb salvage treatment option at Colorado State University Veterinary Teaching Hospital for dogs with extremity bone tumors. Optimal dose delivery to the tumor during SBRT treatment can be limited by uncertainty in skin dose calculation. The aim of this study was to characterize the difference between measured and calculated radiation dose by the Varian Eclipse (Varian Medical Systems, Palo Alto, CA) AAA treatment planning algorithm (for 1-mm, 2-mm, and 5-mm calculation voxel dimensions) as a function of distance from the skin surface. The study used Gafchromic EBT film (International Specialty Products, Wayne, NJ), FilmQA analysis software, a limb phantom constructed from plastic water Trade-Mark-Sign (fluke Biomedical, Everett, WA) and a canine cadaver forelimb. The limb phantom was exposed to 6-MV treatments consisting of a single-beam, a pair of parallel opposed beams, and a 7-beam coplanar treatment plan. The canine forelimb was exposed to the 7-beam coplanar plan. Radiation dose to the forelimb skin at the surface and at depths of 1.65 mm and 1.35 mm below the skin surface were also measured with the Gafchromic film. The calculation algorithm estimated the dose well at depths beyond buildup for all calculation voxel sizes. The calculation algorithm underestimated the dose in portions of the buildup region of tissue for all comparisons, with the most significant differences observed in the 5-mm calculation voxel and the least difference in the 1-mm voxel. Results indicate a significant difference between measured and calculated data

  12. Measurement of turbulence intensity in the center of the canine ascending aorta with a hot-film anemometer.

    Science.gov (United States)

    Yamaguchi, T; Kikkawa, S; Yoshikawa, T; Tanishita, K; Sugawara, M

    1983-05-01

    The blood flow velocity near the central axis of the canine ascending aorta was measured with a hot-film anemometer. The cardiac output and the heart rate were controlled at will by means of an extracorporeal circulation and by atrial pacing. The turbulent component of the blood flow velocity was calculated using an ensemble average technique. Ensemble average turbulent intensity was also calculated to show the time course of turbulence in the aorta. The ratio of the mean turbulence intensity to the time mean sectional average velocity in the aorta was constant in most animals regardless of the changes in fluid mechanical parameters. The correlation between the frequency parameter and the relative mean turbulence intensity was weakly positive. The power spectrum of the turbulence was also calculated.

  13. Interpretation of electrokinetic measurements with porous films: role of electric conductance and streaming current within porous structure.

    Science.gov (United States)

    Yaroshchuk, Andriy; Luxbacher, Thomas

    2010-07-06

    It is shown that in tangential electrokinetic measurements with porous films the porous structure makes contribution not only to the cell electric conductance (as demonstrated previously) but also to the observed streaming current. Both of these contributions give rise to dependences of streaming-potential and streaming-current coefficients on the channel height. However, due to the combined contribution of two phenomena, the dependence of streaming-potential coefficient on the channel height may be rather complicated and not allow for simple extrapolation. At the same time, the dependences of streaming-current coefficient and cell electric conductance on the channel height turn out linear and can be easily extrapolated to zero channel heights. This enables one to determine separately the contributions of external surface of porous film and of its porous structure to the streaming current and of the channel and porous structure to the cell electric conductance. This procedure is illustrated by the measurements of tangential electrokinetic phenomena and electric conductance with Millipore mixed-cellulose membrane filters of various average pore sizes (from 0.025 to 5 mum) in the so-called adjustable-gap cell of SurPASS electrokinetic instrument (Anton Paar GmbH). The design of this cell allows for easy and quasi-continuous variation of channel height as well as accurate determination of cell electric conductance, streaming-current coefficient, and channel height (from the cell hydraulic permeability). The quality of linear fits of experimental data has been found to be very good, and thus, the extrapolation procedures were quite reliable and accurate. Zeta-potentials could be determined of both external film and internal pore surfaces. It is demonstrated that the porous structures make considerable contributions to both streaming-current coefficient and cell electric conductance especially in the case of filters with larger pores. It is also found that, rather

  14. Wet/dry film thickness measurement of paint by absorption spectroscopy with acousto-optic tunable filter spectrometer

    Science.gov (United States)

    Sinha, Pranay G.; Xiong, Xiangchun; Jin, Feng; Trivedi, Sudhir; Prasad, Narashima S.

    2005-08-01

    Controlling/monitoring the thickness of applied paint in real time is important to many situations including painting ship and submarine hulls in dry docks for maintaining health of ships and submarines against the harshness of the sea, in automobile and aerospace industries, and in a variety of other industries as a control sensor that plays significant role in product quality, process control, and cost control. Insufficient thickness results to inadequate protection while overspray leads to waste and pollution of the environment. A rugged instrumentation for the real time non-contact accurate measurement of wet and dry paint film thickness measurement will be immensely valuable. As paint is applied with several layers of the same or different type, thickness of each newly sprayed wet layer is of most interest, but measurement on dry paint is also useful. In this study, we use acousto-optic tunable filter-based near infrared spectrometer to obtain the absorption spectrum of layers of paint sprayed on sand blasted steel surface and thus measure the thickness of coating under both wet and dry situations. NIR spectra are obtained from 1100 to 2300 nm on four sample of different thickness of paint up to 127 micron. Partial least squares model built with the spectra shows good correlation with standard error of prediction within ~ 0.7 micron. Results indicate that the spectra also respond to the amount of organic solvent in the wet paint and can be used to monitor the degree of dryness of the paint in real time.

  15. Measurement of thermal accommodation of spin-polarized hydrogen on a saturated 4He film at 0.18--0.4 K

    International Nuclear Information System (INIS)

    Helffrich, J.; Maley, M.P.; Krusius, M.; Wheatley, J.C.

    1986-01-01

    The thermal accommodation of H-gas atoms on a saturated superfluid- 4 He-film-covered surface has been measured in the temperature range 0.18--0.4 K. A straightforward stationary-state measuring technique is employed whereby we determine the heat flux conducted by H-gas atoms from a superfluid- 4 He-film-covered bolometer, biased above ambient temperature. The results agree with recent calculations of the thermal-accommodation properties dominated by sticking-evaporation collisions mediated by ripplon creation

  16. Direct measurement of magnetoelectric exchange in self-assembled epitaxial BiFeO3-CoFe2O4 nanocomposite thin films

    Science.gov (United States)

    Yan, Li; Xing, Zengping; Wang, Zhiguang; Wang, Tao; Lei, Guangyin; Li, Jiefang; Viehland, D.

    2009-05-01

    We report the direct measurement of a magnetoelectric (ME) exchange between magnetostrictive CoFe2O4 nanopillars in a piezoelectric BiFeO3 matrix for single-layer nanocomposite epitaxial thin films grown on (001) SrTiO3 substrates with SrRuO3 bottom electrodes. The ME coefficient was measured by a magnetic cantilever method and had a maximum value of ˜20 mV/cm Oe. The films possessed saturation polarization (60 μC/cm2) and magnetization (410 emu/cc) properties equivalent to bulk values, with typical hysteresis loops.

  17. SPOTS Calibration Example

    Directory of Open Access Journals (Sweden)

    Patterson E.

    2010-06-01

    Full Text Available The results are presented using the procedure outlined by the Standardisation Project for Optical Techniques of Strain measurement to calibrate a digital image correlation system. The process involves comparing the experimental data obtained with the optical measurement system to the theoretical values for a specially designed specimen. The standard states the criteria which must be met in order to achieve successful calibration, in addition to quantifying the measurement uncertainty in the system. The system was evaluated at three different displacement load levels, generating strain ranges from 289 µstrain to 2110 µstrain. At the 289 µstrain range, the calibration uncertainty was found to be 14.1 µstrain, and at the 2110 µstrain range it was found to be 28.9 µstrain. This calibration procedure was performed without painting a speckle pattern on the surface of the metal. Instead, the specimen surface was prepared using different grades of grit paper to produce the desired texture.

  18. Lithography-free resistance thermometry based technique to accurately measure Seebeck coefficient and electrical conductivity for organic and inorganic thin films

    Science.gov (United States)

    Kumar, Pawan; Repaka, D. V. Maheswar; Hippalgaonkar, Kedar

    2017-12-01

    We have developed a new and accurate technique to measure temperature dependent in-plane Seebeck coefficient and electrical conductivity of organic and inorganic thin films. The measurement device consists of one heater, two thermometers, and a four-probe configuration which is patterned on a substrate of choice using a simple shadow mask. The high resolution in temperature measurements and repeatability of resistance thermometry is leveraged while enabling simple implementation using only a shadow mask for patterning. We calibrate the technique using nickel and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) thin films. The error bar for the Seebeck coefficient is less than 1%, almost 10 times better than complementary techniques for thin films. Moreover, our method enables high-throughput characterization of thermoelectric properties of a variety of different large area inorganic and organic thin films that can be prepared by spin coating, drop casting, evaporation, sputtering, or any other growth technique and hence has potential for wide usage in the thermoelectrics and nanoscale transport community to study thin films.

  19. Is this Red Spot the Blue Spot (locus ceruleum)?

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Won Sick; Lee, Yu Kyung; Lee, Min Kyung; Hwang, Kyung Hoon [Gachon University Gil Hospital, Incheon (Korea, Republic of)

    2010-06-15

    The authors report brain images of 18F-FDG-PET in a case of schizophrenia. The images showed strikingly increased bilateral uptake in the locus ceruleum. The locus ceruleum is called the blue spot and known to be a center of the norepinephrinergic system.

  20. Thermal conductivity measurements of high and low thermal conductivity films using a scanning hot probe method in the 3ω mode and novel calibration strategies.

    Science.gov (United States)

    Wilson, Adam A; Muñoz Rojo, Miguel; Abad, Begoña; Perez, Jaime Andrés; Maiz, Jon; Schomacker, Jason; Martín-Gonzalez, Marisol; Borca-Tasciuc, Diana-Andra; Borca-Tasciuc, Theodorian

    2015-10-07

    This work discusses measurement of thermal conductivity (k) of films using a scanning hot probe method in the 3ω mode and investigates the calibration of thermal contact parameters, specifically the thermal contact resistance (R(th)C) and thermal exchange radius (b) using reference samples with different thermal conductivities. R(th)C and b were found to have constant values (with b = 2.8 ± 0.3 μm and R(th)C = 44,927 ± 7820 K W(-1)) for samples with thermal conductivity values ranging from 0.36 W K(-1) m(-1) to 1.1 W K(-1) m(-1). An independent strategy for the calibration of contact parameters was developed and validated for samples in this range of thermal conductivity, using a reference sample with a previously measured Seebeck coefficient and thermal conductivity. The results were found to agree with the calibration performed using multiple samples of known thermal conductivity between 0.36 and 1.1 W K(-1) m(-1). However, for samples in the range between 16.2 W K(-1) m(-1) and 53.7 W K(-1) m(-1), calibration experiments showed the contact parameters to have considerably different values: R(th)C = 40,191 ± 1532 K W(-1) and b = 428 ± 24 nm. Finally, this work demonstrates that using these calibration procedures, measurements of both highly conductive and thermally insulating films on substrates can be performed, as the measured values obtained were within 1-20% (for low k) and 5-31% (for high k) of independent measurements and/or literature reports. Thermal conductivity results are presented for a SiGe film on a glass substrate, Te film on a glass substrate, polymer films (doped with Fe nano-particles and undoped) on a glass substrate, and Au film on a Si substrate.

  1. Evaluation of the use of radiochromic films alongside of the ionization chamber and TLDs in measuring peripheral doses; Avaliacao do uso de filmes radiocromicos ao lado de camara de ionizacao e TLDs na mensuracao de doses perifericas

    Energy Technology Data Exchange (ETDEWEB)

    Soboll, Danyel S.; Wolter, Brenda Von; Nascimento, Josiane Q., E-mail: soboll@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Viamonte, Alfredo; Alves, Victor G.L., E-mail: aviamonte@inca.gov.br [Instituto Nacional de Cancer (PQRT/INCA), Rio de Janeiro, RJ (Brazil). Programa de Qualidade em Radioterapia

    2014-07-01

    The objective of this work is to submit radiochromic films, thermoluminescent dosimeters and ionization chamber to identical situations irradiation, in order to assess their capabilities in measuring peripheral doses. The growing number of survivors of childhood cancer has created the need to investigate the cause of the sequelae of treatment. Measurements of peripheral radiation to the radiotherapy target region increment the knowledge of the subject and assist in the development of protection methods. As the periphery of the radiation spectrum is different from that in the beam, the energy independence supposedly provided in radiochromic films can overcome the energy dependence found of ionization and TLD chambers, in order to discard the necessity of correction of the values if films are used. In this work the three dosimeters were exposed to doses arising from the issuance of 6 MV beams, field 10 cm x 10 cm and 500 UM. The dosimeters were placed at 0, 10, 17.5 and 30 cm from the central ray, always under 5 cm of water. The results showed that the figures reported by the films have high average standard deviation and for more conclusive results is necessary to proceed with the radiations, employing more intense beams.

  2. Radiochromic film dosimetry

    International Nuclear Information System (INIS)

    Xu Zhiyong

    2002-01-01

    Radiochromic film dosimetry was developed to measure ionization irradiation dose for industry and medicine. At this time, there are no comprehensive guideline on the medical application, calibration method and densitometer system for medicine. The review gives update on Radiochromic film dosimetry used for medicine, including principles, film model and material, characteristics, calibration method, scanning densitometer system and medical application

  3. Simultaneous atomic force microscopy measurement of topography and contact resistance of metal films and carbon nanotubes

    International Nuclear Information System (INIS)

    Stadermann, M.; Grube, H.; Boland, J.J.; Papadakis, S.J.; Falvo, M.R.; Superfine, R.; Washburn, S.

    2003-01-01

    We present a quartz tuning-fork-based atomic force microscopy (AFM) setup that is capable of mapping the surface contact resistance while scanning topography. The tuning-fork setup allows us to use etched Pt/Ir tips, which have higher durability and better conductivity than probes used in earlier AFM conductance measurements. The performance of the method is demonstrated with contact resistance measurements of gold lines on silicon dioxide and carbon nanotubes on graphite

  4. Measurements of surface shear stresses under a three-dimensional turbulent boundary layer using oil-film laser interferometry

    Science.gov (United States)

    Ailinger, K. G.; Simpson, R. L.

    1990-04-01

    Measurements of surface shear stress magnitude and direction are reported for a three-dimensional, pressure driven, turbulent boundary layer around a wing body junction. Measurements were made using a dual-beam oil film laser interferometer at 56 locations. An iterative procedure was developed which increased the precision of the data extracted from the data records. Skin friction directions computed using a least square error fit were compared to angles obtained from surface oil flows, hot wire anemometry, and LDV measurements. Also, the magnitude of the skin friction coefficients were compared to independently obtained skin friction coefficients. The data agreed to within experimental error outside the effects from the vortex legs present along the side of the wing-body. No accurate data was available for quantitative comparison under the effects of the vortex, but the magnitudes followed the qualitative trends expected. This method failed badly in the region of large three-dimensional effects and requires further study in this area of application.

  5. A new contact electric resistance technique for in-situ measurement of the electric resistance of surface films on metals in electrolytes at high temperatures and pressures

    International Nuclear Information System (INIS)

    Saario, T.; Marichev, V.A.

    1993-01-01

    Surface films play a major role in corrosion assisted cracking. A new Contact Electric Resistance (CER) method has been recently developed for in situ measurement of the electric resistance of surface films. The method has been upgraded for high temperature high pressure application. The technique can be used for any electrically conductive material in any environment including liquid, gas or vacuum. The technique has been used to determine in situ the electric resistance of films on metals during adsorption of water and anions, formation and destruction of oxides and hydrides, electroplating of metals and to study the electric resistance of films on semiconductors. The resolution of the CER technique is 10 -9 Ω, which corresponds to about 0.03 monolayers of deposited copper during electrochemical deposition Cu/Cu 2+ . Electric resistance data can be measured with a frequency of the order of one hertz, which enables one to follow in situ the kinetics of surface film related processes. The kinetics of these processes and their dependence on the environment, temperature, pH and electrochemical potential can be investigated

  6. Thin films deposited by laser ablation for the measurement of the ionizing and non-ionizing radiation

    International Nuclear Information System (INIS)

    Villarreal B, J.E.; Escobar A, L.; Camps, E.; Romero, S.; Gonzalez, P.; Salinas, B.

    2001-01-01

    In this work the obtained results to synthesize thin films of amorphous carbon with incorporated nitrogen and hydrogen are presented, as well as thin films of aluminium oxide using the laser ablation technique. The thin films were exposed to ionizing radiation (gamma rays of a 60 Co source, beta radiation of a 90 Sr source) and a non-ionizing radiation (UV radiation). The obtained results show that it is possible to obtain materials in thin film form with thickness of hundreds of nanometers, which present thermoluminescent response when being irradiated with ionizing radiation and non-ionizing radiation. (Author)

  7. Cognitive sophistication does not attenuate the bias blind spot.

    Science.gov (United States)

    West, Richard F; Meserve, Russell J; Stanovich, Keith E

    2012-09-01

    The so-called bias blind spot arises when people report that thinking biases are more prevalent in others than in themselves. Bias turns out to be relatively easy to recognize in the behaviors of others, but often difficult to detect in one's own judgments. Most previous research on the bias blind spot has focused on bias in the social domain. In 2 studies, we found replicable bias blind spots with respect to many of the classic cognitive biases studied in the heuristics and biases literature (e.g., Tversky & Kahneman, 1974). Further, we found that none of these bias blind spots were attenuated by measures of cognitive sophistication such as cognitive ability or thinking dispositions related to bias. If anything, a larger bias blind spot was associated with higher cognitive ability. Additional analyses indicated that being free of the bias blind spot does not help a person avoid the actual classic cognitive biases. We discuss these findings in terms of a generic dual-process theory of cognition.

  8. Domain wall magnetoresistance in BiFeO3 thin films measured by scanning probe microscopy.

    Science.gov (United States)

    Domingo, N; Farokhipoor, S; Santiso, J; Noheda, B; Catalan, G

    2017-08-23

    We measure the magnetotransport properties of individual 71° domain walls in multiferroic BiFeO 3 by means of conductive-atomic force microscopy (C-AFM) in the presence of magnetic fields up to one Tesla. The results suggest anisotropic magnetoresistance at room temperature, with the sign of the magnetoresistance depending on the relative orientation between the magnetic field and the domain wall plane. A consequence of this finding is that macroscopically averaged magnetoresistance measurements for domain wall bunches are likely to underestimate the magnetoresistance of each individual domain wall.

  9. Domain wall magnetoresistance in BiFeO3 thin films measured by scanning probe microscopy

    NARCIS (Netherlands)

    Domingo, N.; Farokhipoor, S.; Santiso, J.; Noheda, B.; Catalan, G.

    2017-01-01

    We measure the magnetotransport properties of individual 71 degrees domain walls in multiferroic BiFeO3 by means of conductive-atomic force microscopy (C-AFM) in the presence of magnetic fields up to one Tesla. The results suggest anisotropic magnetoresistance at room temperature, with the sign of

  10. Dried blood spot measurement of pregnancy-associated plasma protein A (PAPP-A) and free beta-subunit of human chorionic gonadotropin (beta-hCG) from a low-resource setting

    NARCIS (Netherlands)

    Browne, J. L.; Schielen, P. C. J. I.; Belmouden, I.; Pennings, J. L. A.; Klipstein-Grobusch, K.

    ObjectivesThe objectives of the article is to compare pregnancy-associated plasma protein A (PAPP-A) and free -subunit of human chorionic gonadotropin (-hCG) concentrations in dried blood spots (DBSs) with serum of samples obtained from a public hospital in a low-resource setting and to evaluate

  11. Evaluating performance characteristics of x-ray equipment and film systems without the use of electronic measurement and/or special instruments

    International Nuclear Information System (INIS)

    Bianchi, M.F.; DeNitto, C.; Liscio, A.; Scala, N.

    2004-01-01

    Measurement and control of characteristics of NDT equipment and system that produce output to be interpreted by inspector is one of the most important tools for NDT reliability. Control activity should be based on: initial accurate measurement and calibration; periodical check to assure maintenance of calibration status; and, immediate verification and corrective action when any malfunctioning is suspected. 'Self-calibration' intended as capability of NDT facility to calibrate and control its own equipment and systems is very important for continuous and reliable activity. Typical approach based on this philosophy is ASTM E317 'Standard Practice for Evaluating Performance Characteristics of Ultrasonic Pulse-Echo Examination Instruments and Systems Without the Use of Electronic Measurement Instruments' that is applicable to shop or field conditions. Is 'Self-calibration' applicable to radiographic system too? Many characteristics can be self-determined according to existing practices and methods, but other ones require assistance and cooperation of supplier both for film system and x-ray equipment. A certified film system being controlled by pre-exposed filmstrips can be adopted as 'measurement device' for X-ray output concerning both intensity and contrast. Basically x-ray equipment manufacturer performs initial accurate measurement and calibration using electronic measurement and/or special instrumentation as necessary. Then specific film set on 'low-price' blocks and specimens is produced according to standard practice whose guidelines are supplied by this paper. Film set, blocks, specimens and results referred to specific film system will be the reference kit for periodical check in NDT facility. This paper supplies some guidelines for standard practice based on testing using mainly GE Inspection Technologies radiographic system being available in Avio facilities. (author)

  12. Three-dimensional visualization of velocity profiles in the ascending aorta in dogs, measured with a hot-film anemometer.

    Science.gov (United States)

    Paulsen, P K; Hasenkam, J M

    1983-01-01

    Three-dimensional blood velocity profiles were registered in the ascending aorta of dogs approximately 2 and 5 cm above the aortic valves by means of constant temperature hot-film anemometry. The velocity was measured at 41 predetermined points of measurement evenly distributed over the cross-sectional area. Later data analyses using a three-dimensional plotting system, visualized velocity profiles at 200 time intervals during one mean heart cycle. The overall appearance of the profiles was that of a flat transitional flow with a slight skewness. The highest velocity was found nearer to the posterior and left vessel wall. The skewness started during top systole and persisted to the beginning of diastole. Furthermore, many small velocity fluctuations were seen during top systole, but they might also be caused by secondary rotational flow phenomena. This new three-dimensional and dynamic method for visualizing velocity profiles seems to offer advantages, as it demonstrates the total velocity profile all over the cross-sectional area.

  13. Measurement of beta-amyloid peptides in specific cells using a photo thin-film transistor

    Science.gov (United States)

    Kim, Chang-Beom; Chae, Cheol-Joo; Shin, Hye-Rim; Song, Ki-Bong

    2012-01-01

    The existence of beta-amyloid [Aβ] peptides in the brain has been regarded as the most archetypal biomarker of Alzheimer's disease [AD]. Recently, an early clinical diagnosis has been considered a great importance in identifying people who are at high risk of AD. However, no microscale electronic sensing devices for the detection of Aβ peptides have been developed yet. In this study, we propose an effective method to evaluate a small quantity of Aβ peptides labeled with fluorescein isothiocyanate [FITC] using a photosensitive field-effect transistor [p-FET] with an on-chip single-layer optical filter. To accurately evaluate the quantity of Aβ peptides within the cells cultured on the p-FET device, we measured the photocurrents which resulted from the FITC-conjugated Aβ peptides expressed from the cells and measured the number of photons of the fluorochrome in the cells using a photomultiplier tube. Thus, we evaluated the correlation between the generated photocurrents and the number of emitted photons. We also evaluated the correlation between the number of emitted photons and the amount of FITC by measuring the FITC volume using AFM. Finally, we estimated the quantity of Aβ peptides of the cells placed on the p-FET sensing area on the basis of the binding ratio between FITC molecules and Aβ peptides.

  14. Objective evaluation of the sweet spot size in spatial sound reproduction using elevated loudspeakers

    DEFF Research Database (Denmark)

    Lacouture Parodi, Yesenia; Rubak, Per

    2010-01-01

    to the loudspeakers. This paper presents a follow-up evaluation of the performance of the three inversion techniques when the above mentioned conditions are relaxed. A setup to measure the sweet spot of different loudspeaker arrangements is described. The sweet spot was measured for 21 different loudspeaker...

  15. Dressing percentage in Romanian spotted breed

    Directory of Open Access Journals (Sweden)

    eleonora nistor

    2013-05-01

    Full Text Available The purpose of this research was to determine whether there are significant differences in terms of carcass weight, forequarters, hindquarters and the dressing percentage among Romanian Spotted breed steers and first generation crossbreed obtained between Romanian Spotted and Holstein at slaughter age of 12 and 17 months respectively. Study was done on Romanian Spotted breed steer aged 12 months (36 heads and 17 months (19 heads; Romanian Spotted x Holstein first generation crossbreed of aged 12 months (29 heads and 17 months (20 heads. The Romanian Spotted breed steer, show superiority in terms of carcass weight compared to crossbreed of Romanian Spotted x Holstein, therefore this breed has a better suitability for fattening for meat. Regarding dressing percentage is higher in crossbreed of Romanian Spotted x Holstein compared with Romanian Spotted breed steers, but the difference is insignificant.

  16. In vivo sweat film layer thickness measured with Fourier-domain optical coherence tomography

    CSIR Research Space (South Africa)

    Jonathan, E

    2008-01-01

    Full Text Available s Centre form the f th s pr t fi d id Keywords: Fourier-domain optical coherence tomography; Human sweat secretion; Sweat gland; Sweat duct; Hyperhidrosis growing list of triggers include cancer, glucose control disorder, mental stress, social..., that is, the gland, duct and pore(s). However, due to a slow imaging time, COCT is largely restricted to morphometry of human tissue and thickness measurement of biologic and biologic samples [12,13]. ARTICLE IN PRESS Fourier-domain optical coherence...

  17. Dominant white spotting in the Chinese hamster.

    Science.gov (United States)

    Henwood, C; Henwood, J; Robinson, R

    1987-01-01

    An autosomal dominant white spotting mutant is described for the Chinese hamster. The mutant gene is designated as dominant spot (symbol Ds). The homozygote DsDs is a prenatal lethal while the heterozygote Ds + displays white spotting. The expression of white is variable, ranging from a white forehead spot to extensive white on the body. The venter is invariably white. Growth appears to be normal and the fertility of both sizes shows no impairment.

  18. Simultaneous measurement of temperature and tensile loading using superstructure FBGs developed by laser direct writing of periodic on-fiber metallic films

    International Nuclear Information System (INIS)

    Alemohammad, Hamidreza; Toyserkani, Ehsan

    2009-01-01

    This paper addresses the development of superstructure fiber Bragg gratings (FBGs) by laser-assisted direct writing of on-fiber metallic films. A novel laser direct write method is characterized to fabricate periodic films of silver nanoparticles on the non-planar surface of as-fabricated FBGs. Silver films with a thickness of 9 µm are fabricated around a Bragg grating optical fiber. The performance of the superstructure FBG is studied by applying temperature and tensile stress on the fiber. An opto-mechanical model is also developed to predict the optical response of the synthesized superstructure FBG under thermal and structural loadings. The results show that the reflectivity of sidebands in the reflection spectrum can be tuned up to 20% and 37% under thermal and structural loadings, respectively. In addition, the developed superstructure FBG is used for simultaneous measurement of force and temperature to eliminate the inherent limitation of regular FBGs in multi-parameter sensing

  19. Senescent spotting of banana peel is inhibited by modified atmosphere packaging

    NARCIS (Netherlands)

    Choehom, R.; Ketsa, S.; Doorn, van W.G.

    2004-01-01

    Banana fruit (Musa cavendishii [Musa acuminata] AA Group cv. Sucrier) were placed in trays and held at 29-30 degreesC. Covering the trays with 'Sun wrap' polyvinyl chloride film prevented the early senescent peel spotting, typical for this cultivar. Carbon dioxide and ethylene concentrations within

  20. The Use of a Pressure-Indicating Film to Determine the Effect of Liner Type on the Measured Teat Load Caused by a Collapsing Liner

    Science.gov (United States)

    Demba, Susanne; Paul, Viktoria; Ammon, Christian; Rose-Meierhöfer, Sandra

    2017-01-01

    During milking the teat cup liner is the interface between the teat of a dairy cow and the milking system, so it should be very well adapted to the teat. Therefore, the aim of the present study was to determine the effect of liner type on the directly measuring teat load caused by a collapsing liner with a pressure-indicating film. The Extreme Low pressure-indicating film was used to detect the effect of six different liners on teat load. For each liner, six positions in the teat cup were specified, and six repetitions were performed for each position with a new piece of film each time. Analysis of variance was performed to detect differences between the six liners, the positions within a liner, and the measuring areas. The pressure applied to the teat by a liner depends on the technical characteristics of the liner, especially the shape of the barrel, and for all tested liners, a higher teat load was found at the teat end. In conclusion, with the help of pressure-indicating film, it is possible to determine the different effects of liner type by directly measuring teat load due to liner collapse. PMID:28406465

  1. Critical slowing down in the two-dimensional Ising model measured using ferromagnetic ultrathin films

    Science.gov (United States)

    Dunlavy, M. J.; Venus, D.

    2005-04-01

    Power-law scaling of the relaxation time τ associated with critical slowing down has been experimentally measured in the dynamics of the magnetization of a bilayer of iron grown on top of a W(110) substrate using the complex magnetic ac susceptibility χ(T) . The observed value of the critical exponent for the slowing down above the Curie transition of this two-dimensional Ising ferromagnetic system is zν=2.09±0.06 (95% confidence), in agreement with most contemporary theories and simulations. Further analysis reveals that dynamical effects cause χ(T) to deviate from power-law scaling as the temperature is decreased towards Tc , whereas the saturation of the correlation length due to finite-size effects (on the order of 500 lattice spaces) limits the divergence of τ .

  2. A Drosophila wing spot test

    International Nuclear Information System (INIS)

    Ayaki, Toshikazu; Yoshikawa, Isao; Niikawa, Norio; Hoshi, Masaharu.

    1986-01-01

    A Drosophila wing spot test system was used to investigate the effects of low doses of X-rays, gamma rays, and both 2.3 and 14.1 MeV neutrons on somatic chromosome mutation (SCM) induction. The incidence of SCM was significantly increased with any type of radiation, with evident linear dose-response relationship within the range of 3 to 20 cGy. It was estimated that relative biological effectiveness value for SCM induction of 2.3 MeV neutrons to X-rays and gamma rays is much higher than that of 14.1 MeV neutrons to those photons (2.4 vs 8.0). The Drosophila wing spot test system seems to become a promising in vivo experimental method for higher animals in terms of the lack of necessity for a marvelously large number of materials required in conventional test system. (Namekawa, K.)

  3. Sweet Spots and Door Stops

    Science.gov (United States)

    Thompson, Michael; Tsui, Stella; Leung, Chi Fan

    2011-01-01

    A sweet spot is referred to in sport as the perfect place to strike a ball with a racquet or bat. It is the point of contact between bat and ball where maximum results can be produced with minimal effort from the hand of the player. Similar physics can be applied to the less inspiring examples of door stops; the perfect position of a door stop is…

  4. Measuring drug saturation solubility in thin polymer films: use of a thin acceptor layer.

    Science.gov (United States)

    Kunst, Anders; Lee, Geoffrey

    2015-03-15

    The saturation solubility of scopolamine base in two pressure sensitive adhesive DURO-TAKs has been determined using the 5-layer laminate technique. The acceptor layer had a thickness of less than 25 μm to promote a rapid partitioning equilibrium. With DURO-TAK 87-2510 the saturation solubility is 5.2 ± 0.6% w/w when measured after 7 days. With DURO-TAK 87-4098 the saturation solubility is slightly higher, 7.9 ± 0.7% w/w after 7 days. These values remained constant up to approximately 30 days' experimental time. In both cases the acceptor was free of crystalline material at the end of the experiment. This strongly suggests that that equilibrium had been reached between the saturated solution in the acceptor layer and the crystalline drug still present in the donor layer. The addition of light liquid paraffin to the acceptor produced a solubilizing effect with 87-4098 but not 87-2510. We recommend some experimental conditions that we consider to be necessary to achieve a reliable and accurate result with this technique. If performed correctly, it can give a feasible result. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Justifications shape ethical blind spots.

    Science.gov (United States)

    Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

    2015-06-01

    To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information. © The Author(s) 2015.

  6. On the determination of χ(2) in thin films: a comparison of one-beam second-harmonic generation measurement methodologies

    Science.gov (United States)

    Hermans, Artur; Kieninger, Clemens; Koskinen, Kalle; Wickberg, Andreas; Solano, Eduardo; Dendooven, Jolien; Kauranen, Martti; Clemmen, Stéphane; Wegener, Martin; Koos, Christian; Baets, Roel

    2017-03-01

    The determination of the second-order susceptibility (χ(2)) of thin film samples can be a delicate matter since well-established χ(2) measurement methodologies such as the Maker fringe technique are best suited for nonlinear materials with large thicknesses typically ranging from tens of microns to several millimeters. Here we compare two different second-harmonic generation setups and the corresponding measurement methodologies that are especially advantageous for thin film χ(2) characterization. This exercise allows for cross-checking the χ(2) obtained for identical samples and identifying the main sources of error for the respective techniques. The development of photonic integrated circuits makes nonlinear thin films of particular interest, since they can be processed into long waveguides to create efficient nonlinear devices. The investigated samples are ABC-type nanolaminates, which were reported recently by two different research groups. However, the subsequent analysis can be useful for all researchers active in the field of thin film χ(2) characterization.

  7. Monitoring the Degradation Process of Inconel 600 and its Aluminide Coatings under Molten Sulfate Film with Thermal Cycles by Electrochemical Measurements

    International Nuclear Information System (INIS)

    Take, S.; Yoshinaga, S.; Yanagita, M.; Itoi, Y.

    2016-01-01

    With a specially designed electrochemical cell, the changes in impedance behavior for Inconel 600 and aluminide diffusion coatings under molten sulfate film with thermal cycles (from 800 ℃ to 350 ℃) were monitored with electrochemical impedance measurements. It was found that corrosion resistance for both materials increased with lower temperatures. At the same time, the state of molten salt was also monitored successfully by measuring the changes in impedance at high frequency, which generally represents the resistance of molten salt itself. After two thermal cycles, both Inconel 600 and aluminide diffusion coatings showed excellent corrosion resistance. The results from SEM observation and EDS analysis correlated well with the results obtained by electrochemical impedance measurements. It is concluded that electrochemical impedance is very useful for monitoring the corrosion resistance of materials under molten salt film conditions even with thermal cycles.

  8. SU-E-T-44: Angular Dependence of Surface Dose Enhancement Measured On Several Inhomogeneities Using Radiochromic EBT3 Films

    Energy Technology Data Exchange (ETDEWEB)

    Jansen, A; Schoenfeld, A; Poppinga, D; Chofor, N; Poppe, B [University of Oldenburg, Oldenburg (Germany); Pius Hospital Oldenburg, Oldenburg (Germany)

    2014-06-01

    Purpose: The quantification of the relative surface dose enhancement in dependence on the angle of incidence and the atomic number Z of the surface material. Methods: Experiments were performed with slabs made of aluminum, titanium, copper, silver, dental gold and lead. The metal slabs with equal sizes of 1.0×8.0×8.8mm{sup 3} were embedded in an Octavius 4D phantom (PTW Freiburg, Germany). Radiochromic EBT3 films were used to measure the surface dose for angles of incidence ranging from 0° to 90°. The setup with the metals slabs at the isocenter was irradiated with acceleration voltages of 6MV and 10MV. Water reference measurements were taken under equal conditions. Results: The surface dose enhancement is highest for angles of incidence below 30° and drops significantly for higher. The surface dose enhancement produced by lead and dental gold at 6MV showed a peak of 65%. At 90°, the surface dose enhancement dropped to 15% for both materials. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 32%, 22% and 12% at 0°, respectively. At an angle of incidence of 80°, the values dropped to 22%, 18%, 12% und 6%. The values for 10MV were very similar. Lead and dental gold showed peaks of 65% und 60%. Their values dropped to 18% at an angle of 90°. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 30%, 20% and 8% at 0°. At 80° the values dropped to 30%, 20%, 12% and 5%. A dependence of the magnitude of the surface dose enhancement on the atomic number of the surface material can be seen, which is in consistence with literature. Conclusion: The results show that the surface dose enhancements near implant materials with high Z-values should be taken into consideration in radio therapy, even when the angle of incidence is flat.

  9. SU-E-T-44: Angular Dependence of Surface Dose Enhancement Measured On Several Inhomogeneities Using Radiochromic EBT3 Films

    International Nuclear Information System (INIS)

    Jansen, A; Schoenfeld, A; Poppinga, D; Chofor, N; Poppe, B

    2014-01-01

    Purpose: The quantification of the relative surface dose enhancement in dependence on the angle of incidence and the atomic number Z of the surface material. Methods: Experiments were performed with slabs made of aluminum, titanium, copper, silver, dental gold and lead. The metal slabs with equal sizes of 1.0×8.0×8.8mm 3 were embedded in an Octavius 4D phantom (PTW Freiburg, Germany). Radiochromic EBT3 films were used to measure the surface dose for angles of incidence ranging from 0° to 90°. The setup with the metals slabs at the isocenter was irradiated with acceleration voltages of 6MV and 10MV. Water reference measurements were taken under equal conditions. Results: The surface dose enhancement is highest for angles of incidence below 30° and drops significantly for higher. The surface dose enhancement produced by lead and dental gold at 6MV showed a peak of 65%. At 90°, the surface dose enhancement dropped to 15% for both materials. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 32%, 22% and 12% at 0°, respectively. At an angle of incidence of 80°, the values dropped to 22%, 18%, 12% und 6%. The values for 10MV were very similar. Lead and dental gold showed peaks of 65% und 60%. Their values dropped to 18% at an angle of 90°. The surface dose enhancements for silver, copper, titanium and aluminum were 45%, 30%, 20% and 8% at 0°. At 80° the values dropped to 30%, 20%, 12% and 5%. A dependence of the magnitude of the surface dose enhancement on the atomic number of the surface material can be seen, which is in consistence with literature. Conclusion: The results show that the surface dose enhancements near implant materials with high Z-values should be taken into consideration in radio therapy, even when the angle of incidence is flat

  10. A Hot-Stage Atomic Force Microscope for the Measurement of Plastic Deformation in Metallic Thin Films During Thermal Cycling

    National Research Council Canada - National Science Library

    Shultz, Thomas

    2001-01-01

    .... The system will allow future in-situ thermal cycling experiments on microelectronic devices in a protected environment to provide insight into the role of plastic deformation in metallic thin films...

  11. Nanoscale leakage current measurements in metal organic chemical vapor deposition crystalline SrTiO3 films

    International Nuclear Information System (INIS)

    Rozier, Y.; Gautier, B.; Hyvert, G.; Descamps, A.; Plossu, C.; Dubourdieu, C.; Ducroquet, F.

    2009-01-01

    The properties of SrTiO 3 thin films, grown by liquid injection metal organic chemical vapor deposition on Si/SiO 2 , using a mixture of precursors, have been investigated at the nanoscale using an Atomic Force Microscope in the so-called Conductive Atomic Force Microscopy mode. Maps of the leakage currents with a nanometric resolution have been obtained on films elaborated at different temperatures and stoichiometries in order to discriminate the role of each parameter on the onset of leakage currents in the resulting layers. It appears that the higher the deposition temperature, the higher the leakage currents of the films. The mapping with a nanometric precision allows to show a heterogeneous behaviour of the surface with leaky grains and insulating boundaries. The study of films elaborated at the same temperature with different compositions supports the assumption that the leakage currents on Ti-rich layers are far higher than on Sr-rich layers

  12. Nanoscale leakage current measurements in metal organic chemical vapor deposition crystalline SrTiO{sub 3} films

    Energy Technology Data Exchange (ETDEWEB)

    Rozier, Y. [Lyon Institute of Nanotechnology (INL), CNRS-UMR5270, INSA Lyon, 7 avenue Capelle, 69621 VILLEURBANNE Cedex (France); Gautier, B. [Lyon Institute of Nanotechnology (INL), CNRS-UMR5270, INSA Lyon, 7 avenue Capelle, 69621 VILLEURBANNE Cedex (France)], E-mail: bgautier@insa-lyon.fr; Hyvert, G.; Descamps, A.; Plossu, C. [Lyon Institute of Nanotechnology (INL), CNRS-UMR5270, INSA Lyon, 7 avenue Capelle, 69621 VILLEURBANNE Cedex (France); Dubourdieu, C. [Laboratoire des Materiaux et du Genie Physique (LMGP), CNRS, INPG, 3 parvis L. Neel, BP 257, 38016 Grenoble Cedex 1 (France); Ducroquet, F. [Institut de Microelectronique, Electromagnetisme et Photonique (IMEP), 3, rue Parvis Louis Neel BP 257, 38016 GRENOBLE Cedex 1 (France)

    2009-01-30

    The properties of SrTiO{sub 3} thin films, grown by liquid injection metal organic chemical vapor deposition on Si/SiO{sub 2}, using a mixture of precursors, have been investigated at the nanoscale using an Atomic Force Microscope in the so-called Conductive Atomic Force Microscopy mode. Maps of the leakage currents with a nanometric resolution have been obtained on films elaborated at different temperatures and stoichiometries in order to discriminate the role of each parameter on the onset of leakage currents in the resulting layers. It appears that the higher the deposition temperature, the higher the leakage currents of the films. The mapping with a nanometric precision allows to show a heterogeneous behaviour of the surface with leaky grains and insulating boundaries. The study of films elaborated at the same temperature with different compositions supports the assumption that the leakage currents on Ti-rich layers are far higher than on Sr-rich layers.

  13. Probing fundamental film parameters of immobilized enzymes--towards enhanced biosensor performance. Part I--QCM-D mass and rheological measurements.

    Science.gov (United States)

    Fogel, R; Limson, J L

    2011-07-10

    Enzyme immobilization is an ever-growing research-area for both analytical and industrial applications. Of critical importance in this area are the effects of immobilization procedures upon the functionality of the immobilized biomolecules. Both beneficial and detrimental effects can be conferred through the selection and tuning of the immobilization procedure. Quartz-crystal microbalance with dissipation (QCM-D) has been previously used to great effect in tracking alterations to thin films of biomolecules immobilized onto quartz transducers. In this study, we investigate the ability of QCM-D to track and monitor film parameters of a monolayer of laccase immobilized on a series of self-assembled monolayers (SAMs), differing in lateral density of binding residues on the SAM and height of the SAM from the quartz surface. Both mass gains and rheological parameters for these varying surfaces were measured and trends later compared to the apparent enzyme kinetics of the immobilized laccase films, assessed electroanalytically (Paper II in this two part study). For covalent attachment of proteins, both shear and viscosity were increased relative to physically adsorbed proteins. An increase in lateral density of protein-binding surface of the SAM components was shown to increase the shear/viscosity of the resultant film while an increase in distance from the electrode (through incorporation of lysine linkers) was shown to decrease the shear/viscosity while simultaneously increasing the wet mass gain of the films. Shear and viscosity may be indicative of both enzyme denaturation and increased lateral protein packing within the film structure hence it is assumed that less distortion occurs with the inclusion of linkers which allow for more optimal protein immobilization. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Following and Filming Fibromyalgia

    DEFF Research Database (Denmark)

    Schøler, Maja; Blaakilde, Anne Leonora

    -sited. It contains a flow of embodied experiences between human and non-human agents, both by means of words – on a discoursive level – and by means of tactile, intersubjective transmissions of recognizable corporeal expressions. We would like to make one final comment to this paper: Following the theoretical...... from FM comprises a very complex situation, difficult to grasp, and, unfit for the traditional Cartesian conceptualization. The reaction from the outside to the sufferer is therefore often: "But you look so good!" (Connotatively implying, how can you be in pain?) In response to the difficulties...... in at least 11 spots, she is diagnosed with FM. We will now show a video spot with a woman being tested by the tenderpoint-test. The woman performs pain reactions to 18 of the 18 tenderpoints and thereby suffers of Fibromyalgia at a severe level. Show film (2 min ca.) Method In order to study FM...

  15. Evidence for the spotting hypothesis in gymnasts.

    Science.gov (United States)

    Heinen, Thomas

    2011-04-01

    The goal of this study was to investigate the visual spotting hypothesis in 10 experts and 10 apprentices as they perform back aerial somersaults from a standing position with no preparatory jumps (short flight duration condition) and after some preparatory jumps with a flight time of 1s (long flight duration condition). Differences in gaze behavior and kinematics were expected between experts and apprentices and between experimental conditions. Gaze behavior was measured using a portable and wireless eye-tracking system in combination with a movement-analysis system. Experts exhibited a smaller landing deviation from the middle of the trampoline bed than apprentices. Experts showed higher fixation ratios during the take-off and flight phase. Experts exhibited no blinks in any of the somersaults in both conditions, whereas apprentices showed significant blink ratios in both experimental conditions. The findings suggest that gymnasts can use visual spotting during the back aerial somersault, even when the time of flight is delimited. We conclude that knowledge about gaze-movement relationships may help coaches develop specific training programs in the learning process of the back aerial somersault.

  16. A time-scale sensitometric method for evaluating screen - film systems

    International Nuclear Information System (INIS)

    Goes, E.G.; Pela, C.A.; Ghilardi, N.T.

    1997-01-01

    An x-ray sensitometer is used to measure the characteristic curve of radiographic films exposed with fluorescent intensifying screens. The series of relative exposures, necessary to cover the full density range of the film, can be obtained by either time-scale or intensity-scale sensitometric methods. We have developed a convenient method of exposing film-screen systems for time-scale sensitometry. In this method, during exposure the x-ray kilovoltage, tube current and x-ray intensity remain constant and a geometric series of exposures of the film is modulated by varying the exposure time. This time variation can be obtained when a lead disc with different sector openings is rotated in front of the film system by a stepping motor. The conditions normally used are 70 kVp x-rays, 3.5 mm Al total filtration at the tube, and 2.4 m focal spot-film distance. This exposure latitude gives a complete characteristic curve of film-screen systems. (author)

  17. A time-scale sensitometric method for evaluating screen - film systems

    Energy Technology Data Exchange (ETDEWEB)

    Goes, E.G.; Pela, C.A.; Ghilardi, N.T. [CIDRA - Centro de Instrumentacao, Dosimetria e Radioprotecao, DFM - FFCLRP - USP, Av. Bandeirantes, 3900-14040 901 Ribeirao Preto, SP (Brazil)

    1997-10-01

    An x-ray sensitometer is used to measure the characteristic curve of radiographic films exposed with fluorescent intensifying screens. The series of relative exposures, necessary to cover the full density range of the film, can be obtained by either time-scale or intensity-scale sensitometric methods. We have developed a convenient method of exposing film-screen systems for time-scale sensitometry. In this method, during exposure the x-ray kilovoltage, tube current and x-ray intensity remain constant and a geometric series of exposures of the film is modulated by varying the exposure time. This time variation can be obtained when a lead disc with different sector openings is rotated in front of the film system by a stepping motor. The conditions normally used are 70 kVp x-rays, 3.5 mm Al total filtration at the tube, and 2.4 m focal spot-film distance. This exposure latitude gives a complete characteristic curve of film-screen systems. (author)

  18. Synthesis and characterization of boron carbon nitride thin films as protective overcoat for hard disk drives

    Science.gov (United States)

    Chen, Yanfeng

    The current goal in the magnetic storage industry is to reach the areal density of 1Tbit/in2 in a few years. This requires the head-media spacing (HMS), which includes media overcoat, lubricant layer, air bearing, and head overcoat, not to exceed 5.0 nm. Trade-off between these layers results in requiring the protective overcoat to be 1.0 nm or less. The protective overcoat must be hard, wear-resistant, continuous, thermally stable, and compatible with the magnetic layer and lubricant. This thesis work is mainly to develop protective overcoat for ultra high density hard disk drives (HDD). Amorphous carbon nitride (a-CNx) thin films were synthesized using pulseDC magnetron sputtering. The influence of substrate bias, substrate tilt, and substrate rotation on film growth and properties was studied. X-ray reflectivity (XRR) was used to measure film density, roughness and thickness. Surface roughness and thickness measurements from XRR are comparable to AFM and surface profiler measurements respectively. a-CNx films have good mechanical properties. Auger electron spectroscopy (AES) and high resolution transmission microscope (HRTEM) were used to obtain the film composition and microstructure. HRTEM cross sectioned experiments showed that CN x film is amorphous. Chemical corrosion experiments display drastic decrease of corrosion spots for thin films synthesized under optimum conditions. In pursuit of new materials for hard disk drive protective overcoat, boron carbide (B4C) and boron carbon nitride (BxC yNz) thin films were synthesized by pulse-DC magnetron sputtering. Effects of target power, target pulse frequency, substrate bias and pulse frequency on surface roughness were studied by AFM. Nitrogen incorporation into B4C films, which gives BxCyNz thin films, has a beneficial effect to decrease the film roughness. Auger electron spectroscopy was used to characterize the film composition. High-resolution cross-sectioned TEM studies showed that both films are amorphous

  19. Water Sorption in Electron-Beam Evaporated SiO2 on QCM Crystals and Its Influence on Polymer Thin Film Hydration Measurements.

    Science.gov (United States)

    Kushner, Douglas I; Hickner, Michael A

    2017-05-30

    Spectroscopic ellipsometry (SE) and quartz crystal microbalance (QCM) measurements are two critical characterization techniques routinely employed for hydration studies of polymer thin films. Water uptake by thin polymer films is an important area of study to investigate antifouling surfaces, to probe the swelling of thin water-containing ionomer films, and to conduct fundamental studies of polymer brush hydration and swelling. SiO 2 -coated QCM crystals, employed as substrates in many of these hydration studies, show porosity in the thin electron-beam (e-beam) evaporated SiO 2 layer. The water sorption into this porous SiO 2 layer requires correction of the optical and mass characterization of the hydrated polymer due to changes in the SiO 2 layer as it sorbs water. This correction is especially important when experiments on SiO 2 -coated QCM crystals are compared to measurements on Si wafers with dense native SiO 2 layers. Water adsorption filling void space during hydration in ∼200-260 nm thick SiO 2 layers deposited on a QCM crystal resulted in increased refractive index of the layer during water uptake experiments. The increased refractive index led to artificially higher polymer swelling in the optical modeling of the hydration experiments. The SiO 2 -coated QCM crystals showed between 6 and 8% void as measured by QCM and SE, accounting for 60%-85% of the measured polymer swelling in the low humidity regime (70% RH) from optical modeling for 105 and 47 nm thick sulfonated polymer films. Correcting the refractive index of the SiO 2 layer for its water content resulted in polymer swelling that successfully resembled swelling measured on a silicon wafer with nonporous native oxide.

  20. Sweet Spot Size in Virtual Sound Reproduction: A Temporal Analysis

    DEFF Research Database (Denmark)

    Lacouture Parodi, Yesenia; Rubak, Per

    2009-01-01

    The influence of head misalignments on the performance of binaural reproduction systems through loudspeakers is often evaluated in the frequency domain. The changes in magnitude give us an idea of how much of the crosstalk is leaked into the direct signal and therefore a sweet spot performance can......-correlation we estimate the interaural time delay and define a sweet spot. The analysis is based on measurements carried out on 21 different loudspeaker configurations, including two- and four-channels arrangements. Results show that closely spaced loudspeakers are more robust to lateral displacements than wider...... span angles. Additionally, the sweet spot as a function of head rotations increases systematically when the loudspeakers are placed at elevated positions....